WorldWideScience

Sample records for multiple effect evaporation

  1. Steam consumption minimization model in a multiple evaporation effect in a sugar plant

    International Nuclear Information System (INIS)

    Villada, Fernando; Valencia, Jaime A; Moreno, German; Murillo, J. Joaquin

    1992-01-01

    In this work, a mathematical model to minimize the steam consumption in a multiple effect evaporation system is shown. The model is based in the dynamic programming technique and the results are tested in a Colombian sugar mill

  2. Integration of thermo-vapor compressor with multiple-effect evaporator

    International Nuclear Information System (INIS)

    Sharan, Prashant; Bandyopadhyay, Santanu

    2016-01-01

    Highlights: • Energy integration of thermo-vapor compressor with multiple-effect evaporator. • Proposed a new methodology for optimal placement of thermo-vapor compressor. • Extended Pinch Analysis for overall energy conservation. • Obtained simultaneous reduction in evaporator area requirement and energy consumption with optimal integration. - Abstract: Thermo-vapor compressor (TVC) is used for compressing the low-pressure vapor with the help of the high-pressure motive steam, to produce the medium pressure vapor. A substantial portion of energy may be conserved by integrating TVC with the multiple-effect evaporator (MEE). The common practice in desalination industry is to compress the vapor produced in the last effect of a MEE using TVC to reduce the overall motive steam requirement. Such integration does not necessarily guarantee energy optimality. The objective of the present work is to optimally integrate TVC with a MEE system to maximize the gain output ratio (GOR). GOR is defined as the ratio of the mass flow rate of vapor produced in MEE to the mass flow rate of the motive steam supplied to TVC. GOR is the measure of the energy efficiency of MEE system. Using the principles of Pinch Analysis and techniques of mathematical optimization, a new methodology for integration of TVC with MEE is proposed in this paper. This is the first analytical methodology to optimally integrate TVC with MEE, avoiding multiple simulations of the overall system. A Theorem is proposed to directly calculate the optimal location of TVC suction position. The proposed methodology gives the designer the freedom to design an MEE-TVC with minimum energy consumption and without carrying out the detailed simulation of the entire system. The methodology is demonstrated through the illustrative case studies for concentrating corn glucose, and freshwater production through thermal desalination. In the case of corn glucose, the optimal integration of TVC with 2-effect MEE resulted in

  3. Modeling Pan Evaporation for Kuwait by Multiple Linear Regression

    Science.gov (United States)

    Almedeij, Jaber

    2012-01-01

    Evaporation is an important parameter for many projects related to hydrology and water resources systems. This paper constitutes the first study conducted in Kuwait to obtain empirical relations for the estimation of daily and monthly pan evaporation as functions of available meteorological data of temperature, relative humidity, and wind speed. The data used here for the modeling are daily measurements of substantial continuity coverage, within a period of 17 years between January 1993 and December 2009, which can be considered representative of the desert climate of the urban zone of the country. Multiple linear regression technique is used with a procedure of variable selection for fitting the best model forms. The correlations of evaporation with temperature and relative humidity are also transformed in order to linearize the existing curvilinear patterns of the data by using power and exponential functions, respectively. The evaporation models suggested with the best variable combinations were shown to produce results that are in a reasonable agreement with observation values. PMID:23226984

  4. Evaporators

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard

    1996-01-01

    Type of evaporators. Regulation. Thermal dimensioning. Determination of pressure loss and heat transfer coefficients.......Type of evaporators. Regulation. Thermal dimensioning. Determination of pressure loss and heat transfer coefficients....

  5. A Multiple-Scale Analysis of Evaporation Induced Marangoni Convection

    KAUST Repository

    Hennessy, Matthew G.

    2013-04-23

    This paper considers the stability of thin liquid layers of binary mixtures of a volatile (solvent) species and a nonvolatile (polymer) species. Evaporation leads to a depletion of the solvent near the liquid surface. If surface tension increases for lower solvent concentrations, sufficiently strong compositional gradients can lead to Bénard-Marangoni-type convection that is similar to the kind which is observed in films that are heated from below. The onset of the instability is investigated by a linear stability analysis. Due to evaporation, the base state is time dependent, thus leading to a nonautonomous linearized system which impedes the use of normal modes. However, the time scale for the solvent loss due to evaporation is typically long compared to the diffusive time scale, so a systematic multiple scales expansion can be sought for a finite-dimensional approximation of the linearized problem. This is determined to leading and to next order. The corrections indicate that the validity of the expansion does not depend on the magnitude of the individual eigenvalues of the linear operator, but it requires these eigenvalues to be well separated. The approximations are applied to analyze experiments by Bassou and Rharbi with polystyrene/toluene mixtures [Langmuir, 25 (2009), pp. 624-632]. © 2013 Society for Industrial and Applied Mathematics.

  6. A Multiple-Scale Analysis of Evaporation Induced Marangoni Convection

    KAUST Repository

    Hennessy, Matthew G.; Mü nch, Andreas

    2013-01-01

    This paper considers the stability of thin liquid layers of binary mixtures of a volatile (solvent) species and a nonvolatile (polymer) species. Evaporation leads to a depletion of the solvent near the liquid surface. If surface tension increases for lower solvent concentrations, sufficiently strong compositional gradients can lead to Bénard-Marangoni-type convection that is similar to the kind which is observed in films that are heated from below. The onset of the instability is investigated by a linear stability analysis. Due to evaporation, the base state is time dependent, thus leading to a nonautonomous linearized system which impedes the use of normal modes. However, the time scale for the solvent loss due to evaporation is typically long compared to the diffusive time scale, so a systematic multiple scales expansion can be sought for a finite-dimensional approximation of the linearized problem. This is determined to leading and to next order. The corrections indicate that the validity of the expansion does not depend on the magnitude of the individual eigenvalues of the linear operator, but it requires these eigenvalues to be well separated. The approximations are applied to analyze experiments by Bassou and Rharbi with polystyrene/toluene mixtures [Langmuir, 25 (2009), pp. 624-632]. © 2013 Society for Industrial and Applied Mathematics.

  7. Evaporation

    International Nuclear Information System (INIS)

    Delaney, B.T.; Turner, R.J.

    1989-01-01

    Evaporation has long been used as a unit operation in the manufacture of various products in the chemical-process industries. In addition, it is currently being used for the treatment of hazardous wastes such as radioactive liquids and sludges, metal-plating wastes, and other organic and inorganic wastes. Design choice is dependent on the liquid to be evaporated. The three most common types of evaporation equipment are the rising-film, falling-film, and forced-circulation evaporators. The first two rely on boiling heat transfer and the latter relies on flash vaporization. Heat exchangers, flash tanks, and ejectors are common auxiliary equipment items incorporated with evaporator bodies to complete an evaporator system. Properties of the liquid to be evaporated are critical in final selection of an appropriate evaporator system. Since operating costs are a significant factor in overall cost, heat-transfer characteristics and energy requirements are important considerations. Properties of liquids which are critical to the determination of final design include: heat capacity, heat of vaporization, density, thermal conductivity, boiling point rise, and heat-transfer coefficient. Evaporation is an expensive technology, both in terms of capital costs and operating costs. Additionally, mechanical evaporation produces a condensate and a bottoms stream, one or both of which may require further processing or disposal. 3 figs

  8. Heat Load Sharing in a Capillary Pumped Loop with Multiple Evaporators and Multiple Condensers

    Science.gov (United States)

    Ku, Jentung

    2005-01-01

    This paper describes the heat load sharing function among multiple parallel evaporators in a capillary pumped loop (CPL). In the normal mode of operation, the evaporators cool the instruments by absorbing the waste heat. When an instruments is turned off, the attached evaporator can keep it warm by receiving heat from other evaporators serving the operating instruments. This is referred to as heat load sharing. A theoretical basis of heat load sharing is given first. The fact that the wicks in the powered evaporators will develop capillary pressure to force the generated vapor to flow to cold locations where the pressure is lower leads to the conclusion that heat load sharing is an inherent function of a CPL with multiple evaporators. Heat load sharing has been verified with many CPLs in ground tests. Experimental results of the Capillary Pumped Loop 3 (CAPL 3) Flight Experiment are presented in this paper. Factors that affect the amount of heat being shared are discussed. Some constraints of heat load sharing are also addressed.

  9. Evaporative cooling: Effective latent heat of evaporation in relation to evaporation distance from the skin

    NARCIS (Netherlands)

    Havenith, G.; Bröde, P.; Hartog, E.A. den; Kuklane, K.; Holmer, I.; Rossi, R.M.; Richards, M.; Farnworth, B.; Wang, X.

    2013-01-01

    Calculation of evaporative heat loss is essential to heat balance calculations. Despite recognition that the value for latent heat of evaporation, used in these calculations, may not always reflect the real cooling benefit to the body, only limited quantitative data on this is available, which has

  10. Concentration of saline produced water from coalbed methane gas wells in multiple-effect evaporator using waste heat from the gas compressor and compressor drive engine

    International Nuclear Information System (INIS)

    Sadler, L.Y.; George, O.

    1995-01-01

    The use of heat of compression from the gas compressor and waste heat from the diesel compressor drive engine in a triple-effect feed forward evaporator was studied as a means of concentrating saline produced water to facilitate its disposal. The saline water, trapped in deeply buried coal seams, must be continuously pumped from coalbed natural gas wells so that the gas can desorb from the coal and make its way to the wellbore. Unlike conventional natural gas which is associated with petroleum and usually reaches the wellhead at high pressure, coalbed natural gas reaches the wellhead at low pressure, usually around 101 kPa (1 atm), and must be compressed near the well site for injection into gas transmission pipelines. The water concentration process was simulated for a typical 3.93 m 3 /s (500 MCF/h), at standard conditions (101 kPa, 289K), at the gas production field in the Warrior Coal Basin of Alabama, but has application to the coalbed gas fields being brought into production throughout the world. It was demonstrated that this process can be considered for concentrating saline water produced with natural gas in cases where the gas must be compressed near the wellhead for transportation to market. 9 refs., 1 fig., 2 tabs

  11. [Effect of biochar addition on soil evaporation.

    Science.gov (United States)

    Xu, Jian; Niu, Wen Quan; Zhang, Ming Zhi; Li, Yuan; Lyu, Wang; Li, Kang-Yong; Zou, Xiao-Yang; Liang, Bo-Hui

    2016-11-18

    In order to determine the rational amount of biochar application and its effect on soil hydrological processes in arid area, soil column experiments were conducted in the laboratory using three biochar additions (5%, 10% and 15%) and four different biochar types (devaporation. The results showed that the addition of biochar could change the phreatic water recharge, soil water-holding capacity, capillary water upward movement and soil evaporation obviously. But the effects were different depending on the type of biochar raw material and the size of particle. The phreatic water recharge increased with the increasing amount of biochar addition. The addition of biochar could obviously enlarge the soil water-holding capacity and promote the capillary water upward movement rate. This effect was greater when using the material of bamboo charcoal compared with using wood charcoal, while biochar with small particle size had greater impact than that with big particle size. The biochar could effectively restrain the soil evaporation at a low addition amount (5%). But it definitely promoted the soil evaporation if the addition amount was very high. In arid area, biochar addition in appropriate amount could improve soil water retention capacity.

  12. A Robust Two-Phase Pumped Loop With Multiple Evaporators and Multiple Radiators, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's future spacecraft require advanced thermal management technologies to provide effective cooling for multiple instruments and reject heat through multiple...

  13. Evaluation of multiple satellite evaporation products in two dryland regions using GRACE

    KAUST Repository

    Lopez, Oliver; McCabe, Matthew; Houborg, Rasmus

    2015-01-01

    Remote sensing has become a valuable tool for monitoring the water cycle variables in areas that lack the availability of ground-based measurements. Integrating multiple remote sensing-based estimates of evaporation, precipitation

  14. A kinetic model of droplet heating and evaporation: Effects of inelastic collisions and a non-unity evaporation coefficient

    KAUST Repository

    Sazhin, Sergei S.; Xie, Jianfei; Shishkova, Irina N.; Elwardani, Ahmed Elsaid; Heikal, Morgan Raymond

    2013-01-01

    The previously developed kinetic model for droplet heating and evaporation into a high pressure air is generalised to take into account the combined effects of inelastic collisions between molecules in the kinetic region, a non-unity evaporation

  15. Evaporation effect on two-dimensional wicking in porous media.

    Science.gov (United States)

    Benner, Eric M; Petsev, Dimiter N

    2018-03-15

    We analyze the effect of evaporation on expanding capillary flow for losses normal to the plane of a two-dimensional porous medium using the potential flow theory formulation of the Lucas-Washburn method. Evaporation induces a finite steady state liquid flux on capillary flows into fan-shaped domains which is significantly greater than the flux into media of constant cross section. We introduce the evaporation-capillary number, a new dimensionless quantity, which governs the frontal motion when multiplied by the scaled time. This governing product divides the wicking behavior into simple regimes of capillary dominated flow and evaporative steady state, as well as the intermediate regime of evaporation influenced capillary driven motion. We also show flow dimensionality and evaporation reduce the propagation rate of the wet front relative to the Lucas-Washburn law. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Effects of maternal inhalation of gasoline evaporative ...

    Science.gov (United States)

    In order to assess potential health effects resulting from exposure to ethanol-gasoline blend vapors, we previously conducted neurophysiological assessment of sensory function following gestational exposure to 100% ethanol vapor (Herr et al., Toxicologist, 2012). For comparison purposes, the current study investigated the same measures after gestational exposure to 100% gasoline evaporative condensates (GVC). Pregnant Long-Evans rats were exposed to 0, 3K, 6K, or 9K ppm GVC vapors for 6.5 h/day over GD9 – GD20. Sensory evaluations of male offspring began around PND106. Peripheral nerve function (compound action potentials, NCV), somatosensory (cortical and cerebellar evoked potentials), auditory (brainstem auditory evoked responses), and visual evoked responses were assessed. Visual function assessment included pattern elicited visual evoked potentials (VEP), VEP contrast sensitivity, and electroretinograms (ERG) recorded from dark-adapted (scotopic) and light-adapted (photopic) flashes, and UV and green flicker. Although some minor statistical differences were indicated for auditory and somatosensory responses, these changes were not consistently dose- or stimulus intensity-related. Scotopic ERGs had a statistically significant dose-related decrease in the b-wave implicit time. All other parameters of ERGs and VEPs were unaffected by treatment. All physiological responses showed changes related to stimulus intensity, and provided an estimate of detectable le

  17. Evaluation of multiple satellite evaporation products in two dryland regions using GRACE

    KAUST Repository

    Lopez, Oliver

    2015-12-01

    Remote sensing has become a valuable tool for monitoring the water cycle variables in areas that lack the availability of ground-based measurements. Integrating multiple remote sensing-based estimates of evaporation, precipitation, and the terrestrial water storage changes with local measurements of streamflow into a consistent estimate of the regional water budget is a challenge, due to the scale mismatch among the retrieved variables. Evapotranspiration, including soil evaporation, interception losses and canopy transpiration, has received special focus in a number of recent studies that aim to provide global or regional estimates of evaporation at regular time intervals using a variety of remote sensing input. In arid and semi-arid regions, modeling of evaporation is particularly challenging due to the relatively high role of the soil evaporation component in these regions and the variable nature of rainfall events that drive the evaporation process. In this study, we explore the hydrological consistency of remote sensing products in terms of water budget closure and the correlation among spatial patterns of precipitation (P), evaporation (E) and terrestrial water storage, using P-E as a surrogate of water storage changes, with special attention to the evaporation component. The analysis is undertaken within two dryland regions that have presented recent significant changes in climatology (Murray-Darling Basin in Australia) and water storage (the Saq aquifer in northern Saudi Arabia). Water storage changes were derived from the Gravity Recovery and Climate Experiment (GRACE) spherical harmonic (SH) coefficients. Six remote sensing-based evaporation estimates were subtracted from the Global Precipitation Climatology Project (GPCP)-based precipitation estimates and were compared with GRACE-derived water storage changes. Our results suggest that it is not possible to close the water balance by using satellite data alone, even when adopting a spherical harmonic

  18. Maldistribution in airewater heat pump evaporators. Part 1: Effects on evaporator, heat pump and system level

    DEFF Research Database (Denmark)

    Mader, Gunda; Palm, Björn; Elmegaard, Brian

    2015-01-01

    This paper presents an approach to quantify the effect of evaporator maldistribution onoperating costs of air-water heat pumps. In the proposed simulation model maldistributionis induced by two parameters describing refrigerant phase and air flow distribution.Annual operating costs are calculated...

  19. Smart Control of Multiple Evaporator Systems with Wireless Sensor and Actuator Networks

    Directory of Open Access Journals (Sweden)

    Apolinar González-Potes

    2016-02-01

    Full Text Available This paper describes the complete integration of a fuzzy control of multiple evaporator systems with the IEEE 802.15.4 standard, in which we study several important aspects for this kind of system, like a detailed analysis of the end-to-end real-time flows over wireless sensor and actuator networks (WSAN, a real-time kernel with an earliest deadline first (EDF scheduler, periodic and aperiodic tasking models for the nodes, lightweight and flexible compensation-based control algorithms for WSAN that exhibit packet dropouts, an event-triggered sampling scheme and design methodologies. We address the control problem of the multi-evaporators with the presence of uncertainties, which was tackled through a wireless fuzzy control approach, showing the advantages of this concept where it can easily perform the optimization for a set of multiple evaporators controlled by the same smart controller, which should have an intelligent and flexible architecture based on multi-agent systems (MAS that allows one to add or remove new evaporators online, without the need for reconfiguring, while maintaining temporal and functional restrictions in the system. We show clearly how we can get a greater scalability, the self-configuration of the network and the least overhead with a non-beacon or unslotted mode of the IEEE 802.15.4 protocol, as well as wireless communications and distributed architectures, which could be extremely helpful in the development process of networked control systems in large spatially-distributed plants, which involve many sensors and actuators. For this purpose, a fuzzy scheme is used to control a set of parallel evaporator air-conditioning systems, with temperature and relative humidity control as a multi-input and multi-output closed loop system; in addition, a general architecture is presented, which implements multiple control loops closed over a communication network, integrating the analysis and validation method for multi

  20. Geometry Effects of Capillary on the Evaporation from the Meniscus

    International Nuclear Information System (INIS)

    Choi, Choong Hyo; Jin, Song Wan; Yoo, Jung Yul

    2007-01-01

    The effect of capillary cross-section geometry on evaporation is investigated in terms of the meniscus shape, evaporation rate and evaporation-induced flow for circular, square and rectangular cross-sectional capillaries. The shapes of water and ethanol menisci are not much different from each other in square and rectangular capillaries even though the surface tension of water is much larger than that of ethanol. On the other hand, the shapes of water and ethanol menisci are very different from each other in circular capillary. The averaged evaporation fluxes in circular and rectangular capillaries are measured by tracking the meniscus position. At a given position, the averaged evaporation flux in rectangular capillaries in much larger than that in circular capillary with comparable hydraulic diameter. The flow near the evaporating meniscus is also measured using micro-PIV, so that the rotating vortex motion is observed near the evaporating ethanol and methanol menisci except for the case of methanol meniscus in rectangular capillary. This difference is considered to be due to the existence of corner menisci at the four corners

  1. Isotope effects accompanying evaporation of water from leaky containers.

    Science.gov (United States)

    Rozanski, Kazimierz; Chmura, Lukasz

    2008-03-01

    Laboratory experiments aimed at quantifying isotope effects associated with partial evaporation of water from leaky containers have been performed under three different settings: (i) evaporation into dry atmosphere, performed in a dynamic mode, (ii) evaporation into dry atmosphere, performed in a static mode, and (iii) evaporation into free laboratory atmosphere. The results demonstrate that evaporative enrichment of water stored in leaky containers can be properly described in the framework of the Craig-Gordon evaporation model. The key parameter controlling the degree of isotope enrichment is the remaining fraction of water in the leaking containers. Other factors such as temperature, relative humidity, or extent of kinetic fractionation play only minor roles. Satisfactory agreement between observed and predicted isotope enrichments for both (18)O and (2)H in experiments for the case of evaporation into dry atmosphere could be obtained only when molecular diffusivity ratios of isotope water molecules as suggested recently by Cappa et al. [J. Geophys. Res., 108, 4525-4535, (2003).] were adopted. However, the observed and modelled isotope enrichments for (2)H and (18)O could be reconciled also for the ratios of molecular diffusivities obtained by Merlivat [J. Chem. Phys., 69, 2864-2871 (1978).], if non-negligible transport resistance in the viscous liquid sub-layer adjacent to the evaporating surface is considered. The evaporation experiments revealed that the loss of mass of water stored in leaky containers in the order of 1%, will lead to an increase of the heavy isotope content in this water by ca. 0.35 and 1.1 per thousand, for delta (18)O and delta (2)H, respectively.

  2. Effect of evaporator temperature on vapor compression refrigeration system

    Directory of Open Access Journals (Sweden)

    Abdullah A.A.A. Al-Rashed

    2011-12-01

    Full Text Available This paper presents a comparable evaluation of R600a (isobutane, R290 (propane, R134a, R22, for R410A, and R32 an optimized finned-tube evaporator, and analyzes the evaporator effect on the system coefficient of performance (COP. Results concerning the response of a refrigeration system simulation software to an increase in the amount of oil flowing with the refrigerant are presented. It is shown that there is optima of the apparent overheat value, for which either the exchanged heat or the refrigeration coefficient of performance (COP is maximized: consequently, it is not possible to optimize both the refrigeration COP and the evaporator effect. The obtained evaporator optimization results were incorporated in a conventional analysis of the vapor compression system. For a theoretical cycle analysis without accounting for evaporator effects, the COP spread for the studied refrigerants was as high as 11.7%. For cycle simulations including evaporator effects, the COP of R290 was better than that of R22 by up to 3.5%, while the remaining refrigerants performed approximately within a 2% COP band of the R22 baseline for the two condensing temperatures considered.

  3. Effects of Topography-driven Micro-climatology on Evaporation

    Science.gov (United States)

    Adams, D. D.; Boll, J.; Wagenbrenner, N. S.

    2017-12-01

    The effects of spatial-temporal variation of climatic conditions on evaporation in micro-climates are not well defined. Current spatially-based remote sensing and modeling for evaporation is limited for high resolutions and complex topographies. We investigated the effect of topography-driven micro-climatology on evaporation supported by field measurements and modeling. Fourteen anemometers and thermometers were installed in intersecting transects over the complex topography of the Cook Agronomy Farm, Pullman, WA. WindNinja was used to create 2-D vector maps based on recorded observations for wind. Spatial analysis of vector maps using ArcGIS was performed for analysis of wind patterns and variation. Based on field measurements, wind speed and direction show consequential variability based on hill-slope location in this complex topography. Wind speed and wind direction varied up to threefold and more than 45 degrees, respectively for a given time interval. The use of existing wind models enables prediction of wind variability over the landscape and subsequently topography-driven evaporation patterns relative to wind. The magnitude of the spatial-temporal variability of wind therefore resulted in variable evaporation rates over the landscape. These variations may contribute to uneven crop development patterns observed during the late growth stages of the agricultural crops at the study location. Use of hill-slope location indexes and appropriate methods for estimating actual evaporation support development of methodologies to better define topography-driven heterogeneity in evaporation. The cumulative effects of spatially-variable climatic factors on evaporation are important to quantify the localized water balance and inform precision farming practices.

  4. Experimental Investigation of Double Effect Evaporative Cooling Unit

    Directory of Open Access Journals (Sweden)

    Ahmed Abd Mohammad Saleh

    2018-03-01

    Full Text Available This work presents the experimental investigation of double effect evaporative cooling unit with approximate capacity 7 kW. The unit consisted of two stages, the sensible heat exchanger and the cooling tower composing the external indirect regenerative evaporative cooling stage where a direct evaporative cooler represent the second stage. Testing results showed a maximum capacity and lowest supplied air temperature when the water flow rate in heat exchanger was 0.1 L/s. The experiment recorded the unit daily readings at two airflow rates (0.425 m3/s, 0.48 m3/s. The reading shows that unit inlet DBT is effect positively on unit wet bulb effectiveness and unit COP at constant humidity ratio. The air extraction ratio effected positively on the unit wet bulb effectiveness within a certain limit where maximum COP recorded 11.4 when the extraction ratio equal to 40%.

  5. Effects of black hole evaporation on the quantum entangled state

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Doyeol [University of Seoul, Seoul (Korea, Republic of)

    2010-10-15

    We investigate the effect of black hole evaporation on the entangled state in which one party of a pair, Alice, falls into the black hole at formation while the other party, Bob, remains outside the black hole. The final state of a black hole is studied by taking into account a general unitary evolution of a black-hole matter state. The mixedness is found to decrease under a general unitary transformation when the initial matter state is in a mixed state and the mean fidelity at the evaporation is smaller than the fidelity of the quantum teleportation by a factor of the inverse square of the number of states of a black hole. The change in the entanglement of the Alice-Bob pair at evaporation is studied by calculating the entanglement fidelity and eigenvalues of the partial transposed block density matrix. The entanglement fidelity is found to be inversely proportional to the square of the Hilbert space dimension N, and the entanglement could survive the evaporation process.

  6. PHEA-PLA biocompatible nanoparticles by technique of solvent evaporation from multiple emulsions.

    Science.gov (United States)

    Cavallaro, Gennara; Craparo, Emanuela Fabiola; Sardo, Carla; Lamberti, Gaetano; Barba, Anna Angela; Dalmoro, Annalisa

    2015-11-30

    Nanocarriers of amphiphilic polymeric materials represent versatile delivery systems for poorly water soluble drugs. In this work the technique of solvent evaporation from multiple emulsions was applied to produce nanovectors based on new amphiphilic copolymer, the α,β-poly(N-2-hydroxyethyl)-DL-aspartamide-polylactic acid (PHEA-PLA), purposely synthesized to be used in the controlled release of active molecules poorly soluble in water. To this aim an amphiphilic derivative of PHEA, a hydrophilic polymer, was synthesized by derivatization of the polymeric backbone with hydrophobic grafts of polylactic acid (PLA). The achieved copolymer was thus used to produce nanoparticles loaded with α tocopherol (vitamin E) adopted as lipophilic model molecule. Applying a protocol based on solvent evaporation from multiple emulsions assisted by ultrasonic energy and optimizing the emulsification process (solvent selection/separation stages), PHEA-PLA nanostructured particles with total α tocopherol entrapment efficiency (100%), were obtained. The drug release is expected to take place in lower times with respect to PLA due to the presence of the hydrophilic PHEA, therefore the produced nanoparticles can be used for semi-long term release drug delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. MATHEMATICAL MODELING AND SIMULATION OF AUTOMATIC CONTROL FOR QUINTUPLE EFFECT EVAPORATION OF CENTRAL SUGAR “EL PALMAR” IN VENEZUELA

    Directory of Open Access Journals (Sweden)

    Lisoviett Pérez Pinto

    2015-04-01

    Full Text Available In this paper, the mathematical modeling and simulation of the automatic control of the quintuple effect of evaporation of a sugar mill “El Palmar” in Venezuela is made. The multiple effect consist of 5 evaporators Robert type, with equal characteristics, connected in series. Starting from the desired operating conditions and control requirements: level in each evaporator vessel, cane syrup concentration and pressure in the fifth evaporator vessel using mass balances, balance on solids for each evaporator and energy to the barometric condenser is present at the output of the fifth vessel, the nonlinear model of the process is obtained, resulting in a system of multiple inputs and multiple outputs, with strong interactions between variables. In the design of the system of the automatic process control, we are interested in maintaining the variables that characterize the performance of it and they are regulated in an operating point; we proceed to linearize the model around an equilibrium point, resulting in a new model in terms of the variables variations around an environment from that point. Then, it is processed the model obtained in terms of input and output relations, based on the characterization of it in terms of variables and transfer relationships in the complex frequency domain. Finally, the evaporation process is simulated, establishing the adequacy of the model to the real process.

  8. 30 CFR 35.22 - Test to determine effect of evaporation on flammability.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine effect of evaporation on... § 35.22 Test to determine effect of evaporation on flammability. (a) Purpose. The purpose of this test shall be to determine the effect of evaporation on the reduction of fire resistance of a hydraulic fluid...

  9. Influence of heat consumers distribution and flashing vapours effect on steam consumption of evaporation plant of sugar factory

    Directory of Open Access Journals (Sweden)

    A. A. Gromkovskii

    2016-01-01

    Full Text Available The article considered the influence of the heat consumers distribution and the flashing vapours effect juice for multipleevaporator sugar factory on the consumption the main production flow of heat transfer agent – water vapor. The problem of rational distribution of heat transfer agent for of the corps multiple-evaporator is relevant from point of view of energy saving and energysaving heat of the sugar factory. The solution to this problem is advantageously carried out on the basis of quantitative mathematical description of the distribution of vapor on the corps of the evaporation plant. The heat consumers distribution should be based on technical and economic calculation. To solve this problem it is advisable to use a single equation that determines the dependence of the steam flow in the first unit evaporator on the amount of evaporated water and the method of heat consumers distribution for housing. Evaporators sugar factory has two functions – technology and heat, each of which is described by its equation. On the basis of the material and heat balance equations for the realization of the basic functions of the system evaporator written multipleevaporator equations. The solution of this system allows you to obtain the equation of the steam flow and the amount of evaporated water, taking into account the flashing vapours effect. Solution of the system should take into account the accepted design standards of sugar factories. As a result of solving the system of equation is obtained, which allows you to organize and optimize the heat consumers distribution of the corps evaporator. The equation can be used for any number of units evaporator. This equation allows you to assess the efficiency of the evaporation plant of a sugar factory. This is of great practical importance in the modernization of thermal schemes of sugar factories.

  10. New estimation of secondary particle multiplicity of nuclear interactions in proton therapy using multicollisional plus evaporation Monte Carlo calculations

    International Nuclear Information System (INIS)

    Mesa, J.; Rodrigues, T. E.; Garcia-Trapaga, C. E.; Arruda-Neto, J. D. T.; Shtejer, K. . Email. jmesa@ibb.unesp.br

    2007-01-01

    Secondary particles contribute to dose deposition in critical organs outside the irradiated target volume. However, the literature regarding specifically to neutron dose and other secondary particles from proton therapy is limited. This issue is of special relevance for young patients, particularly when life expectancy is long, fundamentally if we consider that the art of cancer treatment is finding the right balance between tumor control and injury to normal tissues. In this work we have obtained spectra and multiplicities for neutrons and other secondary particles emitted in the reactions of protons: p+ 12 C, p+ 16 O, p+ 40 Ca and p+ 14 N, for proton energies from 100 to 200 MeV. In this sense, we have used a quite sophisticate multicollisional Monte Carlo code (MCMC) for pre-equilibrium emission, plus de-excitation of residual nucleus by two ways: evaporation of particles (mainly nucleons, but also composites) and possibly fission in the case of heavy residues. The code was developed in our group, with very recently improvements that take into account Pauli-blocking effects in a novel and more precise way, as well as a more rigorous energy balance, an energy stopping time criterion for pre-equilibrium emission, and the inclusion of deuteron, triton and 3 He emissions in the evaporation step

  11. Preliminary Results of Testing of Flow Effects on Evaporator Scaling

    Energy Technology Data Exchange (ETDEWEB)

    Hu, M.Z.

    2002-02-15

    This investigation has focused on the effects of fluid flow on solids deposition from solutions that simulate the feed to the 2H evaporator at the Savannah River Site. Literature studies indicate that the fluid flow (or shear) affects particle-particle and particle-surface interactions and thus the phenomena of particle aggregation in solution and particle deposition (i.e., scale formation) onto solid surfaces. Experimental tests were conducted with two configurations: (1) using a rheometer to provide controlled shear conditions and (2) using controlled flow of reactive solution through samples of stainless steel tubing. All tests were conducted at 80 C and at high silicon and aluminum concentrations, 0.133 M each, in solutions containing 4 M sodium hydroxide and 1 A4 each of sodium nitrate and sodium nitrite. Two findings from these experiments are important for consideration in developing approaches for reducing or eliminating evaporator scaling problems: (1) The rheometer tests suggested that for the conditions studied, maximum solids deposition occurs at a moderate shear rate, approximately 12 s{sup -1}. That value is expected to be on the order of shear rates that will occur in various parts of the evaporator system; for instance, a 6 gal/min single-phase liquid flow through the 2-in. lift or gravity drain lines would result in a shear rate of approximately 16 s{sup -1}. These results imply that engineering approaches aimed at reducing deposits through increased mixing would need to generate shear near all surfaces significantly greater than 12 s{sup -1}. However, further testing is needed to set a target value for shear that is applicable to evaporator operation. This is because the measured trend is not statistically significant at the 95% confidence interval due to variability in the results. In addition, testing at higher temperatures and lower concentrations of aluminum and silicon would more accurately represent conditions in the evaporator. Without

  12. Climatological effects on heliohydroelectric (HHE) power generation. [Based on evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Kettani, M A

    1973-12-01

    Large scale conversion of solar energy into electricity can be efficiently made by transforming first the solar energy into hydraulic energy by evaporation. This concept has been presented at the International Conference of 1971. Since then work has been done to correlate the power generated by an HHE plant to the climatological variables of a region. The effects of such variables as air temperature, relative humidity, station pressure, and wind speed on the generated power are discussed. The Dawhat Salwah area is being emphasized; however, the results could be generalized to other arid zones.

  13. A kinetic model of droplet heating and evaporation: Effects of inelastic collisions and a non-unity evaporation coefficient

    KAUST Repository

    Sazhin, Sergei S.

    2013-01-01

    The previously developed kinetic model for droplet heating and evaporation into a high pressure air is generalised to take into account the combined effects of inelastic collisions between molecules in the kinetic region, a non-unity evaporation coefficient and temperature gradient inside droplets. It is pointed out that for the parameters typical for Diesel engine-like conditions, the heat flux in the kinetic region is a linear function of the vapour temperature at the outer boundary of this region, but practically does not depend on vapour density at this boundary for all models, including and not including the effects of inelastic collisions, and including and not including the effects of a non-unity evaporation coefficient. For any given temperature at the outer boundary of the kinetic region the values of the heat flux are shown to decrease with increasing numbers of internal degrees of freedom of the molecules. The rate of this decrease is strong for small numbers of these degrees of freedom but negligible when the number of these degrees exceeds 20. This allows us to restrict the analysis to the first 20 arbitrarily chosen degrees of freedom of n-dodecane molecules when considering the effects of inelastic collisions. The mass flux at this boundary decreases almost linearly with increasing vapour density at the same location for all above-mentioned models. For any given vapour density at the outer boundary of the kinetic region the values of the mass flux are smaller for the model, taking into account the contribution of internal degrees of freedom, than for the model ignoring these degrees of freedom. It is shown that the effects of inelastic collisions lead to stronger increase in the predicted droplet evaporation time in Diesel engine-like conditions relative to the hydrodynamic model, compared with the similar increase predicted by the kinetic model considering only elastic collisions. The effects of a non-unity evaporation coefficient are shown to be

  14. Comprehensive exergy analysis of a commercial tomato paste plant with a double-effect evaporator

    International Nuclear Information System (INIS)

    Mojarab Soufiyan, Mohamad; Dadak, Ali; Hosseini, Seyed Sina; Nasiri, Farshid; Dowlati, Majid; Tahmasebi, Maryam; Aghbashlo, Mortaza

    2016-01-01

    In this study, a detailed exergy evaluation of a commercial tomato paste plant with a double-effect evaporator was conducted in order to provide information on the system thermodynamic inefficiencies. Using energy and exergy balance equations, all components of the plant were analyzed individually and their exergetic parameters were calculated on the basis of actual operational data. The required data were obtained from Nazchin tomato paste factory located in Tehran, Iran. In addition, it was attempted to quantify the exergy utilized for processing a given amount of the tomato paste. The results showed that over 82% of the total destroyed exergy in the plant occurred in the boiler combination as the main component wasting exergy. Furthermore, exergy analysis introduced this combination as the main equipment rejecting exergy to the ambient where 4.79% of its total exergy input was lost. The rational exergy efficiency of the first- and second-effect evaporative units was found to be 65.33% and 56.60%, respectively. The specific exergy consumption of the tomato paste production was also determined as 16.83 MJ/kg. Generally, exergy concept and its extensions could be served as a powerful assessment technique to optimize the design and performance of multiple-effect evaporation systems employed in food industry. - Highlights: • Exergy analysis of a tomato paste plant with a double-effect evaporator was done. • 82% of the total exergy destruction rate occurred in the boiler combination. • 16.83 MJ exergy was utilized for production of 1 kg tomato paste. • Optimal number of effects could be potentially found using exergy-based approaches.

  15. Effects of annealing on evaporated SnS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sakrani, Samsudi; Ismail, Bakar [Universiti Teknologi Malaysia, Skudai, Johor Bahru (Malaysia). Dept. of Physics

    1994-12-31

    The effects of annealing of evaporated tin sulphide thin films (SnS) are described. The films were initially deposited onto glass substrate, followed by annealing in an encapsulated carbon block under the running argon gas at 310 degree Celsius. Short time annealing of the films results in a slight change of the compositions to a mix SnS/SnS sub 2 compound, and the tendency of increasing SnS sub 2 formation was observed on the films annealed for longer periods up to 20 hours. X-ray results showed the transformation of SnS peaks (040) and (080) to predominantly SnS sub 2 peaks - (001), (100), (101), and (110). The associated absorption coefficients measured on the films were found to be greater than 10 sup 5 cm sup -1, with indication of higher photon energy leading to the formation of SnS sub 2 compound.

  16. Effects of annealing on evaporated SnS thin films

    International Nuclear Information System (INIS)

    Samsudi Sakrani; Bakar Ismail

    1994-01-01

    The effects of annealing of evaporated tin sulphide thin films (SnS) are described. The films were initially deposited onto glass substrate, followed by annealing in an encapsulated carbon block under the running argon gas at 310 degree Celsius. Short time annealing of the films results in a slight change of the compositions to a mix SnS/SnS sub 2 compound, and the tendency of increasing SnS sub 2 formation was observed on the films annealed for longer periods up to 20 hours. X-ray results showed the transformation of SnS peaks (040) and (080) to predominantly SnS sub 2 peaks - (001), (100), (101), and (110). The associated absorption coefficients measured on the films were found to be greater than 10 sup 5 cm sup -1, with indication of higher photon energy leading to the formation of SnS sub 2 compound

  17. Effects of Evaporation/Condensation on Spreading and Contact Angle of a Volatile Liquid Drop

    Science.gov (United States)

    Zhang, Nengli; Chao, David F.; Singh, Bhim S. (Technical Monitor)

    2000-01-01

    Effects of evaporation/condensation on spreading and contact angle were experimentally studied. A sessile drop of R-113 was tested at different vapor environments to determine the effects of evaporation/condensation on the evolution of contact diameter and contact angle of the drop. Condensation on the drop surface occurs at both the saturated and a nonsaturated vapor environments and promotes the spreading. When the drop is placed in the saturated vapor environment it tends to completely wetting and spreads rapidly. In a nonsaturated vapor environment, the evolution of the sessile drop is divided three stages: condensation-spreading stage, evaporation-retracting stage and rapid contracting stage. In the first stage the drop behaves as in the saturated environment. In the evaporation -retracting stage, the competition between spreading and evaporation of the drop determines the evolution characteristics of the contact diameter and the contact angle. A lower evaporation rate struggles against the spreading power to turn the drop from spreading to retracting with a continuous increase of the contact angle. The drop placed in open air has a much higher evaporation rate. The strong evaporation suppresses the spreading and accelerates the retraction of the drop with a linear decrease of the contact diameter. The contraction of the evaporating drops is gradually accelerated when the contact diameter decreases to 3 min and less till drying up, though the evaporation rate is gradually slowing down.

  18. Flow within an evaporating glycerol-water binary droplet: Segregation by gravitational effects

    Science.gov (United States)

    Li, Yaxing; Lv, Pengyu; Diddens, Christian; Wijshoff, Herman; Versluis, Michel; Lohse, Detlef

    2017-11-01

    The flow within an evaporating glycerol-water binary droplet with Bond number Bo PIV for both sessile and pendant droplets during evaporation process, which surprisingly show opposite radial flow directions - inward and outward, respectively. This observation clearly reveals that gravitational effects play a crucial role in controlling flow fields within the evaporating droplets. We theoretically analyse that this gravity-driven effect is caused by density gradients due to the local concentration difference of glycerol within the droplet triggered by different volatilities of the two components during evaporation. Finally, for confirmation, we numerically simulate the process, revealing a good agreement with experimental results.

  19. Effect of interference of capillary length on evaporation at meniscus

    Science.gov (United States)

    Soma, Shu; Kunugi, Tomoaki; Yokomine, Takehiko; Kawara, Zensaku

    2017-11-01

    In this study, the experimental results on the evaporation characteristics of meniscus in various geometrical configurations which enable to vary a perimeter of liquid-vapor interface and a meniscus curvature were obtained, and the main factor in evaporation process was clarified. As the experimental conditions, the perimeter was adjusted from 1mm to 100mm order, and the curvature from the inverse of capillary length, κ( 0.4mm-1) , to about 10mm-1 . Measuring devices for evaporation rate, which consisted of a test section on an electric balance, was set to a reduced pressure environment for making the purified water in the test section evaporate. There is no heater in the test section and system was set to be isolated from outside environment. It was found that the evaporation rate and flux could be organized by the perimeter if the curvature is constant at κ. On the other hand, when the curvature is larger than κ, it was found that the curvature is the dominant factor in the evaporation process. It can be considered that an interference of capillary length is a key to understand these results.

  20. Effect of evaporation on the growth kinetics in a model for two species

    International Nuclear Information System (INIS)

    El-Nashar, Hassan F.

    2002-02-01

    A surface growth model for two species is proposed, when deposition, surface diffusion and evaporation are considered, in (1+1)-dimensions. A Monte Carlo simulation is carried out, focusing on the effect of evaporation on the evolution of the amount of roughness. The results show that the interplay between deposition, surface diffusion and evaporation slows down the rate of growth of the surface width. In addition, when the rate of evaporation increases, the surface width grows faster to a higher value, in comparison to the case of low rate of evaporation. This introduces changes in the scaling exponents which show that evaporation should be given equal or as much consideration as deposition and surface relaxation. (author)

  1. The study on the evaporation cooling efficiency and effectiveness of cooling tower of film type

    International Nuclear Information System (INIS)

    Li Yingjian; You Xinkui; Qiu Qi; Li Jiezhi

    2011-01-01

    Based on heat and mass transport mechanism of film type cooling, which was combined with an on-site test on counter flow film type cooling tower, a mathematical model on the evaporation and cooling efficiency and effectiveness has been developed. Under typical climatic conditions, air conditioning load and the operating condition, the mass and heat balances have been calculated for the air and the cooling water including the volume of evaporative cooling water. Changing rule has been measured and calculated between coefficient of performance (COP) and chiller load. The influences of air and cooling water parameters on the evaporative cooling efficiency were analyzed in cooling tower restrained by latent heat evaporative cooling, and detailed derivation and computation revealed that both the evaporative cooling efficiency and effectiveness of cooling tower are the same characteristics parameters of the thermal performance of a cooling tower under identical assumptions.

  2. Low-dose effects in the sputtering of evaporated films

    International Nuclear Information System (INIS)

    Florio, A.R.O.; Alonso, E.V.; Baragiola, R.A.; Ferron, J.

    1983-01-01

    We report measurements of the dose dependence of the sputtering of evaporated films by 30 keV ions under UHV. An initial (sub-monolayer) enhanced sputtering is attributed to the removal of weakly bound atoms; this enhancement does not depend on the incidence angle of the projectile. (author)

  3. Low-dose effects in the sputtering of evaporated films

    Energy Technology Data Exchange (ETDEWEB)

    Florio, A.R.O.; Alonso, E.V.; Baragiola, R.A.; Ferron, J. (Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche)

    1983-05-01

    We report measurements of the dose dependence of the sputtering of evaporated films by 30 keV ions under UHV. An initial (sub-monolayer) enhanced sputtering is attributed to the removal of weakly bound atoms; this enhancement does not depend on the incidence angle of the projectile.

  4. Effects of Surface Dipole Lengths on Evaporation of Tiny Water Aggregation

    International Nuclear Information System (INIS)

    Wang Shen; Wan Rongzheng; Fang Haiping; Tu Yusong

    2013-01-01

    Using molecular dynamics simulation, we compared evaporation behavior of a tiny amount of water molecules adsorbed on solid surfaces with different dipole lengths, including surface dipole lengths of 1 fold, 2 folds, 4 folds, 6 folds and 8 folds of 0.14 nm and different charges from 0.1e to 0.9e. Surfaces with short dipole lengths (1-fold system) can always maintain hydrophobic character and the evaporation speeds are not influenced, whether the surface charges are enhanced or weakened; but when surface dipole lengths get to 8 folds, surfaces become more hydrophilic as the surface charge increases, and the evaporation speeds increase gradually and monotonically. By tuning dipole lengths from 1-fold to 8-fold systems, we confirmed non-monotonic variation of the evaporation flux (first increases, then decreases) in 4 fold system with charges (0.1e–0.7e), reported in our previous paper [S. Wang, et al., J. Phys. Chem. B 116 (2012) 13863], and also show the process from the enhancement of this unexpected non-monotonic variation to its vanishment with surface dipole lengths increasing. Herein, we demonstrated two key factors to influence the evaporation flux of a tiny amount of water molecules adsorbed on solid surfaces: the exposed surficial area of water aggregation from where the water molecules can evaporate directly and the attraction potential from the substrate hindering the evaporation. In addition, more interestingly, we showed extra steric effect of surface dipoles on further increase of evaporation flux for 2-folds, 4-folds, 6-folds and 8-folds systems with charges around larger than 0.7e. (The steric effect is first reported by parts of our authors [C. Wang, et al., Sci. Rep. 2 (2012) 358]). This study presents a complete physical picture of the influence of surface dipole lengths on the evaporation behavior of the adsorbed tiny amount of water. (condensed matter: structural, mechanical, and thermal properties)

  5. Effects on evaporation rates from different water-permeable pavement designs.

    Science.gov (United States)

    Starke, P; Göbel, P; Coldewey, W G

    2011-01-01

    The urban water balance can be attenuated to the natural by water-permeable pavements (WPPs). Furthermore, WPPs have a 16% higher evaporation rate than impermeable pavements, which can lead to a better urban climate. Evaporation rates from pavements are influenced by the pavement surface and by the deeper layers. By a compared evaporation measurement between different WPP designs, the grain size distribution of the sub-base shows no influence on the evaporation rates in a significant way. On the contrary, a sub-base made of a twin-layer decreases the evaporation by 16% compared to a homogeneous sub-base. By a change in the colour of the paving stone, 19% higher evaporation rates could be achieved. A further comparison shows that the transpiration-effect of the grass in grass pavers increases the evaporation rates more than threefold to pervious concrete pavements. These high evapotranspiration rates can not be achieved with a pervious concrete paving stone. In spite of this, the broad field of application of the pervious concrete paving stone increases the importance in regard to the urban climate.

  6. Isotopic modeling of the sub-cloud evaporation effect in precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Salamalikis, V., E-mail: vsalamalik@upatras.gr [Laboratory of Atmospheric Physics, Department of Physics, University of Patras, GR 26500 Patras (Greece); Argiriou, A.A. [Laboratory of Atmospheric Physics, Department of Physics, University of Patras, GR 26500 Patras (Greece); Dotsika, E. [Stable Isotope Unit, Institute of Nanoscience and Nanotechnology, National Center of Scientific Research ‘Demokritos’, Ag. Paraskevi Attikis, 15310 Athens (Greece)

    2016-02-15

    In dry and warm environments sub-cloud evaporation influences the falling raindrops modifying their final stable isotopic content. During their descent from the cloud base towards the ground surface, through the unsaturated atmosphere, hydrometeors are subjected to evaporation whereas the kinetic fractionation results to less depleted or enriched isotopic signatures compared to the initial isotopic composition of the raindrops at cloud base. Nowadays the development of Generalized Climate Models (GCMs) that include isotopic content calculation modules are of great interest for the isotopic tracing of the global hydrological cycle. Therefore the accurate description of the underlying processes affecting stable isotopic content can improve the performance of iso-GCMs. The aim of this study is to model the sub-cloud evaporation effect using a) mixing and b) numerical isotope evaporation models. The isotope-mixing evaporation model simulates the isotopic enrichment (difference between the ground and the cloud base isotopic composition of raindrops) in terms of raindrop size, ambient temperature and relative humidity (RH) at ground level. The isotopic enrichment (Δδ) varies linearly with the evaporated raindrops mass fraction of the raindrop resulting to higher values at drier atmospheres and for smaller raindrops. The relationship between Δδ and RH is described by a ‘heat capacity’ model providing high correlation coefficients for both isotopes (R{sup 2} > 80%) indicating that RH is an ideal indicator of the sub-cloud evaporation effect. Vertical distribution of stable isotopes in falling raindrops is also investigated using a numerical isotope-evaporation model. Temperature and humidity dependence of the vertical isotopic variation is clearly described by the numerical isotopic model showing an increase in the isotopic values with increasing temperature and decreasing RH. At an almost saturated atmosphere (RH = 95%) sub-cloud evaporation is negligible and the

  7. Isotopic modeling of the sub-cloud evaporation effect in precipitation

    International Nuclear Information System (INIS)

    Salamalikis, V.; Argiriou, A.A.; Dotsika, E.

    2016-01-01

    In dry and warm environments sub-cloud evaporation influences the falling raindrops modifying their final stable isotopic content. During their descent from the cloud base towards the ground surface, through the unsaturated atmosphere, hydrometeors are subjected to evaporation whereas the kinetic fractionation results to less depleted or enriched isotopic signatures compared to the initial isotopic composition of the raindrops at cloud base. Nowadays the development of Generalized Climate Models (GCMs) that include isotopic content calculation modules are of great interest for the isotopic tracing of the global hydrological cycle. Therefore the accurate description of the underlying processes affecting stable isotopic content can improve the performance of iso-GCMs. The aim of this study is to model the sub-cloud evaporation effect using a) mixing and b) numerical isotope evaporation models. The isotope-mixing evaporation model simulates the isotopic enrichment (difference between the ground and the cloud base isotopic composition of raindrops) in terms of raindrop size, ambient temperature and relative humidity (RH) at ground level. The isotopic enrichment (Δδ) varies linearly with the evaporated raindrops mass fraction of the raindrop resulting to higher values at drier atmospheres and for smaller raindrops. The relationship between Δδ and RH is described by a ‘heat capacity’ model providing high correlation coefficients for both isotopes (R"2 > 80%) indicating that RH is an ideal indicator of the sub-cloud evaporation effect. Vertical distribution of stable isotopes in falling raindrops is also investigated using a numerical isotope-evaporation model. Temperature and humidity dependence of the vertical isotopic variation is clearly described by the numerical isotopic model showing an increase in the isotopic values with increasing temperature and decreasing RH. At an almost saturated atmosphere (RH = 95%) sub-cloud evaporation is negligible and the

  8. Nuclear dissipation effects on fission and evaporation in systems of intermediate fissility

    Directory of Open Access Journals (Sweden)

    Gelli N.

    2010-03-01

    Full Text Available The systems of intermediate fissility 132Ce and 158Er have been studied experimentally and theoretically in order to investigate the dissipation properties of nuclear matter. Cross sections of fusion-fission and evaporation residues channels together with charged particles multiplicities in both channels, their spectra, angular correlations and mass-energy distribution of fission fragments have been measured. Theoretical analysis has been performed using multi-dimensional stochastic approach with realistic treatment of particle evaporation. The results of analysis show that full one-body or unusually strong two-body dissipation allows to reproduce experimental data. No temperature dependent dissipation was needed.

  9. On the temperature effect of substrate and evaporation rate on condensate dispersion

    International Nuclear Information System (INIS)

    Orlov, Yu.F.; Belotserkovskaya, N.G.; Gustylev, V.K.

    1978-01-01

    On the basis of available and new experimental data an attempt has been made to generalize the results of studying the effect of the substrate temperature and evaporation rate on the dispersity of amorphous condensates of Sb 2 S 3 and on that of crystalline condensates of PbO and PbTe. The dispersity of the condensates is shown to decrease with a substrate temperature and evaporation rate. The specific surface decreases linearly with the 3-5-fold rise in the evaporation rate. A dispersity decrease is due to the temperature rise in the medium where condensation takes place. The pattern of dispersity dependence on the substrate temperature and evaporation rate does not depend on the mechanism of vapour condensation and is the same both for aerosol mechanism of the condensate formation and for vapour condensation directly on the substrate

  10. Analytical Model for Diffusive Evaporation of Sessile Droplets Coupled with Interfacial Cooling Effect.

    Science.gov (United States)

    Nguyen, Tuan A H; Biggs, Simon R; Nguyen, Anh V

    2018-05-30

    Current analytical models for sessile droplet evaporation do not consider the nonuniform temperature field within the droplet and can overpredict the evaporation by 20%. This deviation can be attributed to a significant temperature drop due to the release of the latent heat of evaporation along the air-liquid interface. We report, for the first time, an analytical solution of the sessile droplet evaporation coupled with this interfacial cooling effect. The two-way coupling model of the quasi-steady thermal diffusion within the droplet and the quasi-steady diffusion-controlled droplet evaporation is conveniently solved in the toroidal coordinate system by applying the method of separation of variables. Our new analytical model for the coupled vapor concentration and temperature fields is in the closed form and is applicable for a full range of spherical-cap shape droplets of different contact angles and types of fluids. Our analytical results are uniquely quantified by a dimensionless evaporative cooling number E o whose magnitude is determined only by the thermophysical properties of the liquid and the atmosphere. Accordingly, the larger the magnitude of E o , the more significant the effect of the evaporative cooling, which results in stronger suppression on the evaporation rate. The classical isothermal model is recovered if the temperature gradient along the air-liquid interface is negligible ( E o = 0). For substrates with very high thermal conductivities (isothermal substrates), our analytical model predicts a reversal of temperature gradient along the droplet-free surface at a contact angle of 119°. Our findings pose interesting challenges but also guidance for experimental investigations.

  11. Capturing the spectrum of interaction effects in genetic association studies by simulated evaporative cooling network analysis.

    Directory of Open Access Journals (Sweden)

    Brett A McKinney

    2009-03-01

    Full Text Available Evidence from human genetic studies of several disorders suggests that interactions between alleles at multiple genes play an important role in influencing phenotypic expression. Analytical methods for identifying Mendelian disease genes are not appropriate when applied to common multigenic diseases, because such methods investigate association with the phenotype only one genetic locus at a time. New strategies are needed that can capture the spectrum of genetic effects, from Mendelian to multifactorial epistasis. Random Forests (RF and Relief-F are two powerful machine-learning methods that have been studied as filters for genetic case-control data due to their ability to account for the context of alleles at multiple genes when scoring the relevance of individual genetic variants to the phenotype. However, when variants interact strongly, the independence assumption of RF in the tree node-splitting criterion leads to diminished importance scores for relevant variants. Relief-F, on the other hand, was designed to detect strong interactions but is sensitive to large backgrounds of variants that are irrelevant to classification of the phenotype, which is an acute problem in genome-wide association studies. To overcome the weaknesses of these data mining approaches, we develop Evaporative Cooling (EC feature selection, a flexible machine learning method that can integrate multiple importance scores while removing irrelevant genetic variants. To characterize detailed interactions, we construct a genetic-association interaction network (GAIN, whose edges quantify the synergy between variants with respect to the phenotype. We use simulation analysis to show that EC is able to identify a wide range of interaction effects in genetic association data. We apply the EC filter to a smallpox vaccine cohort study of single nucleotide polymorphisms (SNPs and infer a GAIN for a collection of SNPs associated with adverse events. Our results suggest an important

  12. Effect of integrating straw into agricultural soils on soil infiltration and evaporation.

    Science.gov (United States)

    Cao, Jiansheng; Liu, Changming; Zhang, Wanjun; Guo, Yunlong

    2012-01-01

    Soil water movement is a critical consideration for crop yield in straw-integrated fields. This study used an indoor soil column experiment to determine soil infiltration and evaporation characteristics in three forms of direct straw-integrated soils (straw mulching, straw mixing and straw inter-layering). Straw mulching is covering the land surface with straw. Straw mixing is mixing straw with the top 10 cm surface soil. Then straw inter-layering is placing straw at the 20 cm soil depth. There are generally good correlations among the mulch integration methods at p soil infiltration, followed by straw mulching. Due to over-burden weight-compaction effect, straw inter-layering somehow retarded soil infiltration. In terms of soil water evaporation, straw mulching exhibited the best effect. This was followed by straw mixing and then straw inter-layering. Straw inter-layering could have a long-lasting positive effect on soil evaporation as it limited the evaporative consumption of deep soil water. The responses of the direct straw integration modes to soil infiltration and evaporation could lay the basis for developing efficient water-conservation strategies. This is especially useful for water-scarce agricultural regions such as the arid/semi-arid regions of China.

  13. Effect of Nd:YAG laser on the solvent evaporation of adhesive systems.

    Science.gov (United States)

    Batista, Graziela Ribeiro; Barcellos, Daphne Câmara; Rocha Gomes Torres, Carlos; Damião, Álvaro José; de Oliveira, Hueder Paulo Moisés; de Paiva Gonçalves, Sérgio Eduardo

    2015-01-01

    This study evaluated the influence of Nd:YAG laser on the evaporation degree (ED) of the solvent components in total-etch and self-etch adhesives. The ED of Gluma Comfort Bond (Heraeus-Kulzer) one-step self-etch adhesive, and Adper Single Bond 2 (3M ESPE), and XP Bond (Dentsply) total-etch adhesives was determined by weight alterations using two techniques: Control--spontaneous evaporation of the solvent for 5 min; Experimental--Nd:YAG laser irradiation for 1 min, followed by spontaneous evaporation for 4 min. The weight loss due to evaporation of the volatile components was measured at baseline and after 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s, 100 s, 110 s, 2 min, 3 min, 4 min, and 5 min. Evaporation of solvent components significantly increased with Nd:YAG laser irradiation for all adhesives investigated. Gluma Comfort Bond showed significantly higher evaporation of solvent components than Adper Single Bond 2 and XP Bond. All the adhesives lost weight quickly during the first min of Nd:YAG laser irradiation. The application of Nd:YAG laser on adhesives before light curing had a significant effect on the evaporation of the solvent components, and the ED of Gluma Comfort Bond one-step self-etch adhesive was significantly higher than with Adper Single Bond 2 and XP Bond total-etch adhesives. The use of the Nd:YAG laser on the uncured adhesive technique can promote a greater ED of solvents, optimizing the longevity of the adhesive restorations.

  14. Design Configuration And Simulation Of A Multi Effects Evaporator For A Desalination Plant

    Directory of Open Access Journals (Sweden)

    Ethar Ali

    2015-08-01

    Full Text Available This research is focused on the economic feasibility of using multi-effect evaporators MEV for the production of potable water for the city of Port Sudan the main port of Sudan. Port Sudan city suffers from chronic shortage of potable water. The study has shown that five effect evaporator plant in Port Sudan can produce 1.41106 m3year at a unit cost of 5m3 with a pay-back period of 7 years. A simulation of the MEV has been performed using Aspen Hysys version 7.3 and produced results were very much similar to these obtained manually.

  15. Gravitational amplitudes in black hole evaporation: the effect of non-commutative geometry

    International Nuclear Information System (INIS)

    Grezia, Elisabetta Di; Esposito, Giampiero; Miele, Gennaro

    2006-01-01

    Recent work in the literature has studied the quantum-mechanical decay of a Schwarzschild-like black hole, formed by gravitational collapse, into almost-flat spacetime and weak radiation at a very late time. The relevant quantum amplitudes have been evaluated for bosonic and fermionic fields, showing that no information is lost in collapse to a black hole. On the other hand, recent developments in non-commutative geometry have shown that, in general relativity, the effects of non-commutativity can be taken into account by keeping the standard form of the Einstein tensor on the left-hand side of the field equations and introducing a modified energy-momentum tensor as a source on the right-hand side. The present paper, relying on the recently obtained non-commutativity effect on a static, spherically symmetric metric, considers from a new perspective the quantum amplitudes in black hole evaporation. The general relativity analysis of spin-2 amplitudes is shown to be modified by a multiplicative factor F depending on a constant non-commutativity parameter and on the upper limit R of the radial coordinate. Limiting forms of F are derived which are compatible with the adiabatic approximation here exploited. Approximate formulae for the particle emission rate are also obtained within this framework

  16. Effects of straw mulching on soil evaporation during the soil thawing period in a cold region in northeastern China

    Science.gov (United States)

    Fu, Qiang; Yan, Peiru; Li, Tianxiao; Cui, Song; Peng, Li

    2018-04-01

    To study the effect of straw mulching on soil water evaporation, it is necessary to measure soil water evaporation under different conditions of straw mulching during the soil thawing period. A field experiment was conducted in winter, and soil evaporation was measured using a microlysimeter on bare land (LD) and 4500 (GF4500), 9000 (GF9000) and 13500 kg/hm2 (GF13500) straw mulch. The influence of different quantities of straw mulch on soil water evaporation during the thawing period was analyzed using the Mallat algorithm, statistical analysis and information cost function. The results showed that straw mulching could delay the thawing of the surface soil by 3-6 d, decrease the speed at which the surface soil thaws by 0.40-0.80 cm/d, delay the peak soil liquid water content, increase the soil liquid water content, reduce the cumulative evaporation by 2.70-7.40 mm in the thawing period, increase the range of soil evaporation by 0.04-0.10 mm in the early stage of the thawing period, and reduce the range of soil evaporation by 0.25-0.90 mm in the late stage of the thawing period. Straw mulching could reduce the range of and variation in soil evaporation and can reduce the effect of random factors on soil evaporation. When the amount of straw mulch exceeded 9000 kg/hm2, the effect of increasing the amount of straw mulch on daily soil water evaporation was small.

  17. Effects of solvent evaporation on water sorption/solubility and nanoleakage of adhesive systems.

    Science.gov (United States)

    Chimeli, Talita Baumgratz Cachapuz; D'Alpino, Paulo Henrique Perlatti; Pereira, Patrícia Nóbrega; Hilgert, Leandro Augusto; Di Hipólito, Vinicius; Garcia, Fernanda Cristina Pimentel

    2014-01-01

    To evaluate the influence of solvent evaporation in the kinetics of water diffusion (water sorption-WS, solubility-SL, and net water uptake) and nanoleakage of adhesive systems. Disk-shaped specimens (5.0 mm in diameter x 0.8 mm in thickness) were produced (N=48) using the adhesives: Clearfil S3 Bond (CS3)/Kuraray, Clearfil SE Bond - control group (CSE)/Kuraray, Optibond Solo Plus (OS)/Kerr and Scotchbond Universal Adhesive (SBU)/3M ESPE. The solvents were either evaporated for 30 s or not evaporated (N=24/per group), and then photoactivated for 80 s (550 mW/cm2). After desiccation, the specimens were weighed and stored in distilled water (N=12) or mineral oil (N=12) to evaluate the water diffusion over a 7-day period. Net water uptake (%) was also calculated as the sum of WS and SL. Data were submitted to 3-way ANOVA/Tukey's test (α=5%). The nanoleakage expression in three additional specimens per group was also evaluated after ammoniacal silver impregnation after 7 days of water storage under SEM. Statistical analysis revealed that only the factor "adhesive" was significant (padhesives. CSE (control) presented significantly lower net uptake (5.4%). The nanoleakage was enhanced by the presence of solvent in the adhesives. Although the evaporation has no effect in the kinetics of water diffusion, the nanoleakage expression of the adhesives tested increases when the solvents are not evaporated.

  18. Lithological Effects on Evaporation and Direct Infiltration Through the Unsaturated Zone in Damascus Oasis (Syria)

    International Nuclear Information System (INIS)

    Abou zakhem, B.

    2004-01-01

    Soil water movement is directly affected by the lithology and texture of soil profile. The objective of this study is to determine water movement mechanism through the unsaturated zone, by estimating the direct infiltration rate and evaporation process in Damascus Oasis, using isotope techniques. Two soil profiles were drilled using a hand-auger. Soil samples were subjected to granulometry, mineralogy, chemical and isotopic analysis. Isotopic measurements indicate that the evaporation front is located at shallow depth between 0 and 2 m. Variations in isotopic content indicate to the alternation of wet and dry periods corresponding to infiltration and evaporation processes respectively. Results show considerable difference in isotopic content between the unsaturated zone and the groundwater, which is mainly attributed to limited recharge of the aquifer through the unsaturated. Whereas the indirect groundwater recharge is considered to be more predominant. Chloride concentration correspond to stable isotopes in the unsaturated zone, it increases proportionally with the evaporation rate. Using chemical balance of Chloride, it was possible to estimate the effective recharge average rate which is ranging between 1.8 mm/y and 0.45 mm/y. The calculated mean evaporation rate according to Barnes and Allison model is 18.1 mm/y at water table level of 3 m depth. This rate decreases to 2.4 mm/y at 6 m depth. (author)

  19. Numerical Study on Radiation Effects to Evaporator in Natural Vacuum Solar Desalination System

    Science.gov (United States)

    Siregar, R. E. T.; Ronowikarto, A. D.; Setyawan, E. Y.; Ambarita, H.

    2018-01-01

    The need for clean water is increasing day by day due to the increasing factor of living standard of mankind, hence designed natural vacuum solar desalination. The natural vacuum Solar desalination is studied experimentally. A small-scale natural vacuum desalination study consists of evaporator and condenser as the main components designed and manufactured. To transfer heat from the solar collector into the evaporator, the fluid transfer system uses a pump powered by a solar cell. Thus, solar collectors are called hybrid solar collectors. The main purpose of this exposure is to know the characteristics of the radiation effects on incoming energy on the evaporator during the process. This system is tested by exposing the unit to the solar radiation in the 4th floor building in Medan. The experiment was conducted from 8.00 to 16.00 local time. The results show that natural vacuum solar desalination with hybrid solar collectors can be operated perfectly. If the received radiation is high, then the incoming energy received by the evaporator will also be high. From measurements with HOBO microstation, obtained the highest radiation 695.6 W/m2, and the calculation result of incoming energy received evaporator obtained highest result 1807.293 W.

  20. Effect of evaporation section and condensation section length on thermal performance of flat plate heat pipe

    International Nuclear Information System (INIS)

    Wang Shuangfeng; Chen Jinjian; Hu Yanxin; Zhang Wei

    2011-01-01

    Flat plate heat pipes (FPHPs) are one of the available technologies to deal with the high density electronic cooling problem due to their high thermal conductivity, reliability, and low weight penalty. A series of experiments were performed to investigate the effect of evaporation and condensation length on thermal performance of flat plate heat pipes. In the experiments, the FPHP had heat transfer length of 255 mm and width of 25 mm, and pure water was used as the working fluid. The results show that comparing to vapor chamber, the FPHP could realize long-distance heat transfer; comparing to the traditional heat pipe, the FPHP has large area contact with heat sources; the thermal resistance decreased and the heat transfer limit increased with the increase of evaporation section length; the FPHP would dry out at a lower heating power with the increase of condensation section length, which indicated that the heat transfer limit decreased, but the evaporator temperature also decreased; when the condensation section length approached to evaporation section length, the FPHP had a better thermal performance. - Highlights: → A strip sintered FPHP is proposed and tested. → The total heat transfer length reaches 255 mm → The efficiency of heat transport reaches 94.4%. → When the condensation section length approached to evaporation section length, the FPHP has better overall performance.

  1. Effect of surfactant concentration on the evaporation of droplets on cotton (Gossypium hirsutum L.) leaves.

    Science.gov (United States)

    Zhou, Zhaolu; Cao, Chong; Cao, Lidong; Zheng, Li; Xu, Jun; Li, Fengmin; Huang, Qiliang

    2018-04-05

    The evaporation kinetics of pesticide droplets deposited on a leaf surface can affect their application efficiency. Evaporation of droplets on the hydrophobic leaves has received considerable attention, but little is known about hydrophilic leaf surfaces. In this study, the effect of surfactant concentration on the evaporation of droplets deposited on cotton leaves was investigated. The evaporation time is roughly decreased for concentrations ranging from 0% to 0.01% and increased from 0.01% to 0.10%. Contrary to the widely held belief that pesticide retention on target crops can rapidly be formed only with surfactant concentrations exceeding the CMC (critical micelle concentration), this study demonstrates that, on hydrophilic cotton leaves, fast evaporation of the droplet at surfactant concentrations of 0.01% (CMC) can reduce the volume quickly, lower the loss point and enhance pesticide retention. In addition, the evolution of droplet volume, height and contact angle on the cotton leaf surface were measured to confirm this conclusion. The result presented herein can be used to guide the use of surfactants and pesticides in agriculture. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Effect of water treatment on the comparative costs of evaporative and dry cooled power plants

    International Nuclear Information System (INIS)

    Gold, H.; Goldstein, D.J.; Yung, D.

    1976-07-01

    The report presents the results of a study on the relative cost of energy from a nominal 1000 Mwe nuclear steam electric generating plant using either dry or evaporative cooling at four sites in the United States: Rochester, New York; Sheridan, Wyoming; Gallup, New Mexico and Dallas, Texas. Previous studies have shown that because of lower efficiencies the total annual evaluated costs for dry cooling systems exceeds the total annual evaluated costs of evaporative cooling systems, not including the cost of water. The cost of water comprises the cost of supplying the makeup water, the cost of treatment of the makeup and/or the circulating water in the tower, and the cost of treatment and disposal of the blowdown in an environmentally acceptable manner. The purpose of the study is to show the effect of water costs on the comparative costs of dry and evaporative cooled towers

  3. Liquid flow rate effects during partial evaporation in a falling film micro contactor

    NARCIS (Netherlands)

    Moschou, P.; Croon, de M.H.J.M.; Schaaf, van der J.; Schouten, J.C.

    2013-01-01

    The focus of this study is the investigation of the effect of liquid flow rate on partial evaporation, enhanced by convective nitrogen flow, in a falling film micro contactor. Experiments are performed at different flow rates and for a certain heating liquid temperature. The temperatures of the gas

  4. Finite size effects in the evaporation rate of 3He clusters

    International Nuclear Information System (INIS)

    Guirao, A.; Pi, M.; Barranco, M.

    1991-01-01

    We have computed the density of states and the evaporation rate of 3 He clusters, paying special attention to finite size effects which modify the 3 He level density parameter and chemical potential from their bulk values. Ready-to-use liquid-drop expansions of these quantities are given. (orig.)

  5. Effects of solvent evaporation on water sorption/solubility and nanoleakage of adhesive systems

    Directory of Open Access Journals (Sweden)

    Talita Baumgratz Cachapuz CHIMELI

    2014-07-01

    Full Text Available Objective: To evaluate the influence of solvent evaporation in the kinetics of water diffusion (water sorption-WS, solubility-SL, and net water uptake and nanoleakage of adhesive systems. Material and Methods: Disk-shaped specimens (5.0 mm in diameter x 0.8 mm in thickness were produced (N=48 using the adhesives: Clearfil S3 Bond (CS3/Kuraray, Clearfil SE Bond - control group (CSE/Kuraray, Optibond Solo Plus (OS/Kerr and Scotchbond Universal Adhesive (SBU/3M ESPE. The solvents were either evaporated for 30 s or not evaporated (N=24/per group, and then photoactivated for 80 s (550 mW/cm2. After desiccation, the specimens were weighed and stored in distilled water (N=12 or mineral oil (N=12 to evaluate the water diffusion over a 7-day period. Net water uptake (% was also calculated as the sum of WS and SL. Data were submitted to 3-way ANOVA/Tukey's test (α=5%. The nanoleakage expression in three additional specimens per group was also evaluated after ammoniacal silver impregnation after 7 days of water storage under SEM. Results: Statistical analysis revealed that only the factor "adhesive" was significant (p<0.05. Solvent evaporation had no influence in the WS and SL of the adhesives. CSE (control presented significantly lower net uptake (5.4%. The nanoleakage was enhanced by the presence of solvent in the adhesives. Conclusions: Although the evaporation has no effect in the kinetics of water diffusion, the nanoleakage expression of the adhesives tested increases when the solvents are not evaporated.

  6. Soil tillage and windbreak effects on millet and cowpea: I. Wind speed, evaporation, and wind erosion

    International Nuclear Information System (INIS)

    Banzhaf, J.; Leihner, D.E.; Buerkert, A.; Serafini, P.G.

    1992-01-01

    Deforestation, overgrazing, and declining soil regeneration periods have resulted in increased wind erosion problems in dry areas of the West African Sahel, but little is known about the bio-physical factors involved. This research was conducted to determine the effects of ridging and four different windbreak spacings on wind erosion, potential evaporation, and soil water reserves. A field trial was conducted from 1985 to 1987 on 12 ha of a Psammentic Paleustalf in Southern Niger. Millet, Pennisetum glaucum (L.), and cowpea, Vigna unguiculata (L.) Walp., were seeded in strips on flat and ridged soil. Windbreaks of savannah vegetation were spaced at 6, 20, 40, and 90 m. The effects of ridging on wind speed, evaporation, and wind erosion were small and mostly non-significant. However, average wind speed at 0.3 m above ground in the center of cowpea and millet strips was significantly reduced from 2.8 to 2.1 m s -1 as windbreak distances narrowed from 90 to 6 m. As a consequence, potential evaporation declined by 15% and the amount of windblown soil particles by 50% in ridged and by 70% in flat treatments. Despite reduced potential evaporation, average subsoil water reserves were 14 mm smaller in the 6- than in the 20-m windbreak spacing indicating excessive water extraction by the windbreak vegetation. Thus, establishing windbreaks with natural savannah vegetation may require a careful consideration of the agronomic benefits and costs to competing crops. 21 refs., 5 figs

  7. Effect of solution processed and thermally evaporated interlayers on the performance of backgrated polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jayawardena, K.D.G.I.; Amarasinghe, K.M.P.; Nismy, N.A. [Advanced Technology Institute, Department of Electronic Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom); Mills, C.A. [Advanced Technology Institute, Department of Electronic Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom); Advanced Coatings Group, Surface Engineering Department, Tata Steel Research Development and Technology, Swinden Technology Centre, Rotherham, S60 3AR (United Kingdom); Silva, S.R.P., E-mail: s.silva@surrey.ac.uk [Advanced Technology Institute, Department of Electronic Engineering, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2015-09-30

    Polymer solar cells are fast gaining momentum as a potential solution towards low cost sustainable energy generation. However, the performance of architectures is known to be limited by the thin film nature of the active layer which, although required due to low charge carrier mobilities, limits the optical coupling to the active layer. The formation of periodic backgratings has been proposed as a solution to this problem. Here, we investigate the effect of solution processed and thermally evaporated interlayers on the performance of backgrated polymer solar cells. Analysis of device performance under standard conditions indicates higher power conversion efficiencies with the incorporation of the evaporated interlayer (5.7%) over a sol–gel processed interlayer (4.9%). This is driven by a more conformal coating as evidenced through two orders of magnitude higher electron mobilities (10{sup −5} versus 10{sup −7} cm{sup 2} V{sup −1} s{sup −1}) as well as the balanced electron and hole transport observed for the former architecture. It is believed that these results will catalyse further development of such device engineering concepts for improved optical coupling in thin film photovoltaics. - Highlights: • Effect of interlayers on backgrated photovoltaic devices is tested. • Evaporated interlayers lead to better device performance. • Better charge extraction is observed for evaporated interlayers.

  8. Effects of straw mulching on soil evaporation during the soil thawing ...

    Indian Academy of Sciences (India)

    26

    Keywords: straw mulching, soil water evaporation, soil thawing period, freezing depth, soil liquid water .... moisture and the soil water evaporation process. The Songnen Plain ...... soils on soil infiltration and evaporation: Water Sci. Technol.

  9. Effect of evaporation on the shelf life of a universal adhesive.

    Science.gov (United States)

    Pongprueksa, P; Miletic, V; De Munck, J; Brooks, N R; Meersman, F; Nies, E; Van Meerbeek, B; Van Landuyt, K L

    2014-01-01

    The purpose of this study was to evaluate how evaporation affects the shelf life of a one-bottle universal adhesive. Three different versions of Scotchbond Universal (SBU, 3M ESPE, Seefeld, Germany) were prepared using a weight-loss technique. SBU0 was left open to the air until maximal weight loss was obtained, whereas SBU50 was left open until 50% of evaporation occurred. In contrast, SBU100 was kept closed and was assumed to contain the maximum concentration of all ingredients. The degree of conversion (DC) was determined by using Fourier transform infrared spectroscopy on different substrates (on dentin or glass plate and mixed with dentin powder); ultimate microtensile strength and microtensile bond strength to dentin were measured as well. DC of the 100% solvent-containing adhesive (SBU100) was higher than that of the 50% (SBU50) and 0% (SBU0) solvent-containing adhesives for all substrates. DC of the adhesive applied onto glass and dehydrated dentin was higher than that applied onto dentin. Even though the ultimate microtensile strength of SBU0 was much higher than that of SBU50 and SBU100, its bond strength to dentin was significantly lower. Evaporation of adhesive ingredients may jeopardize the shelf life of a one-bottle universal system by reducing the degree of conversion and impairing bond strength. However, negative effects only became evident after more than 50% evaporation.

  10. [Study on membrane type leaf water evaporation inhibitors for improving effect of preventing diseases and pest controlling of Lycium barbarum].

    Science.gov (United States)

    Wang, Dan-Dan; Lv, Zhe; Xu, Chang-Qing; Liu, Sai; Chen, Jun; Peng, Xiao; Wu, Yan

    2018-01-01

    Through indoor and field comparative experiments, the properties of membrane type leaf evaporation inhibitors and its effects on photosynthesis of Lycium barbarum and compatibility and synergistic of pesticide were studied. The evaporation inhibitors and L. barbarum were chosen to investigate the suppression of water evaporation and the compatibility with pesticides. The effect of evaporation inhibitors on photosynthesis of L. barbarum leaves was determined by the chlorophyll fluorescence imaging system. The results showed that water evaporation of L. barbarum leaves of different leaf age were evidently suppressed after treated with evaporation inhibitor. The inhibitor was well compatible with pesticide and effectively improved the pesticide efficacy,and had no significant effect on chlorophyll fluorescence parameters. It is concluded that the evaporation inhibitor has good compatibility with the pesticide, and has remarkable effect of restraining moisture evaporation, which make it can be used for reducing the dosage and improving the efficacy of the pesticide in the field of L. barbarum. Copyright© by the Chinese Pharmaceutical Association.

  11. Effect of ambient temperature and relative humidity on interfacial temperature during early stages of drop evaporation.

    Science.gov (United States)

    Fukatani, Yuki; Orejon, Daniel; Kita, Yutaku; Takata, Yasuyuki; Kim, Jungho; Sefiane, Khellil

    2016-04-01

    Understanding drop evaporation mechanisms is important for many industrial, biological, and other applications. Drops of organic solvents undergoing evaporation have been found to display distinct thermal patterns, which in turn depend on the physical properties of the liquid, the substrate, and ambient conditions. These patterns have been reported previously to be bulk patterns from the solid-liquid to the liquid-gas drop interface. In the present work the effect of ambient temperature and humidity during the first stage of evaporation, i.e., pinned contact line, is studied paying special attention to the thermal information retrieved at the liquid-gas interface through IR thermography. This is coupled with drop profile monitoring to experimentally investigate the effect of ambient temperature and relative humidity on the drop interfacial thermal patterns and the evaporation rate. Results indicate that self-generated thermal patterns are enhanced by an increase in ambient temperature and/or a decrease in humidity. The more active thermal patterns observed at high ambient temperatures are explained in light of a greater temperature difference generated between the apex and the edge of the drop due to greater evaporative cooling. On the other hand, the presence of water humidity in the atmosphere is found to decrease the temperature difference along the drop interface due to the heat of adsorption, absorption and/or that of condensation of water onto the ethanol drops. The control, i.e., enhancement or suppression, of these thermal patterns at the drop interface by means of ambient temperature and relative humidity is quantified and reported.

  12. Determination of multiple scattering effects

    International Nuclear Information System (INIS)

    Langevin, M.

    1981-01-01

    The integration of Sigmund and Winterbon numerical values is extended to the reduced thickness tau=2000. The diagram obtained allows a simple determination of the multiple scattering effect for different targets and projectiles [fr

  13. On the evaporation of solar dark matter: spin-independent effective operators

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Zheng-Liang [Institute of High Energy Physics, Chinese Academy of Sciences,19B Yuquan Road, Beijing, 100049 (China); Wu, Yue-Liang; Yang, Zi-Qing; Zhou, Yu-Feng [Kavli Institute for Theoretical Physics China,CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Zhong Guan Cun Street 55#, Beijing, 100190 (China)

    2016-09-13

    As a part of the effort to investigate the implications of dark matter (DM)-nucleon effective interactions on the solar DM detection, in this paper we focus on the evaporation of the solar DM for a set of the DM-nucleon spin-independent (SI) effective operators. In order to put the evaluation of the evaporation rate on a more reliable ground, we calculate the non-thermal distribution of the solar DM using the Monte Carlo methods, rather than adopting the Maxwellian approximation. We then specify relevant signal parameter spaces for the solar DM detection for various SI effective operators. Based on the analysis, we determine the minimum DM masses for which the DM-nucleon coupling strengths can be probed from the solar neutrino observations. As an interesting application, our investigation also shows that evaporation effect can not be neglectd in a recent proposal aiming to solve the solar abundance problem by invoking the momentum-dependent asymmetric DM in the Sun.

  14. On the evaporation of solar dark matter: spin-independent effective operators

    International Nuclear Information System (INIS)

    Liang, Zheng-Liang; Wu, Yue-Liang; Yang, Zi-Qing; Zhou, Yu-Feng

    2016-01-01

    As a part of the effort to investigate the implications of dark matter (DM)-nucleon effective interactions on the solar DM detection, in this paper we focus on the evaporation of the solar DM for a set of the DM-nucleon spin-independent (SI) effective operators. In order to put the evaluation of the evaporation rate on a more reliable ground, we calculate the non-thermal distribution of the solar DM using the Monte Carlo methods, rather than adopting the Maxwellian approximation. We then specify relevant signal parameter spaces for the solar DM detection for various SI effective operators. Based on the analysis, we determine the minimum DM masses for which the DM-nucleon coupling strengths can be probed from the solar neutrino observations. As an interesting application, our investigation also shows that evaporation effect can not be neglectd in a recent proposal aiming to solve the solar abundance problem by invoking the momentum-dependent asymmetric DM in the Sun.

  15. The Effect of 5E Teaching Model on Gifted Students’ Understanding of Evaporation and Condensation

    OpenAIRE

    DEMİRCİOĞLU, Gökhan; DEMİRCİOĞLU, Hülya; VURAL, Selma

    2016-01-01

    The purpose of this study was to investigate effect of activities based on 5E model on 6th grade gifted students’ understanding levels and alternative conceptions concerning evaporation and condensation. In this study, action research method was adopted. Two activities based on 5E model were developed. The activities were applied to 23 6th grade gifted-students enrolled at Ordu Science and Arts Center. A test consisting of three different sections and semi-structured interviews were used to c...

  16. The effect of ambient pressure on the evaporation rate of materials

    Science.gov (United States)

    Naumann, R. J.; Russell, W. M.

    1972-01-01

    A simple expression is obtained using a diffusion model for the effect of ambient pressure on the outgassing or evaporation rate of materials. The correctness of the expression is demonstrated by comparing the estimates from this expression with actual weight loss measurements. It is shown that the rate of mass loss is governed by the ratio of mean free path to the characteristic dimension of the surface in question.

  17. Effect of wall impingement on ambient gas entrainment, fuel evaporation and mixture formation of diesel spray

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Keiya [Department of Mechanical Physics Engineering, University of Hiroshima (Japan); Matsumoto, Yuhei; Zhang, Wu [Mazda Motor Corp. (Japan); Gao, Jian [University of Wisconsin (United States); Moon, Seoksu [Argonne National Laboratory (United States)

    2010-07-01

    In the energy sector, with the implementation of stringent regulations on combustion emissions and the depletion of conventional fuels, there is a pressing need to improve the performance of engines. The purpose of this paper is to determine the impact of wall impingement on several characteristics of diesel spray. Experiments were carried out with both a small and a large amount of diesel spray injected and ambient gas entrainment, fuel evaporation and mixture formation were evaluated using an LAS optical system. Results showed that wall impingement has the same effects for small or large amounts of diesel spray injected; these are: a larger volume spray after the impingement and a smaller volume after it, the suppression of ambient gas entrainment and fuel evaporation, and the shift of the PDF peak of the vapor equivalent ratio. This study provided useful information but further work is needed to address the remaining issues.

  18. Effect of Air Gap Entrapped in Firefighter Protective Clothing on Thermal Resistance and Evaporative Resistance

    Directory of Open Access Journals (Sweden)

    He Hualing

    2018-03-01

    Full Text Available Heat and water vapor transfer behavior of thermal protective clothing is greatly influenced by the air gap entrapped in multilayer fabric system. In this study, a sweating hot plate method was used to investigate the effect of air gap position and size on thermal resistance and evaporative resistance of firefighter clothing under a range of ambient temperature and humidity. Results indicated that the presence of air gap in multilayer fabric system decreased heat and water vapor transfer abilities under normal wear. Moreover, the air gap position slightly influenced the thermal and evaporative performances of the firefighter clothing. In this study, the multilayer fabric system obtained the highest thermal resistance, when the air space was located at position B. Furthermore, the effect of ambient temperature on heat and water vapor transfer properties of the multilayer fabric system was also investigated in the presence of a specific air gap. It was indicated that ambient temperature did not influence the evaporative resistance of thermal protective clothing. A thermographic image was used to test the surface temperature of multilayer fabric system when an air gap was incorporated. These results suggested that a certain air gap entrapped in thermal protective clothing system could affect wear comfort.

  19. Isotope effects in the evaporation of water: a status report of the Craig-Gordon model.

    Science.gov (United States)

    Horita, Juske; Rozanski, Kazimierz; Cohen, Shabtai

    2008-03-01

    The Craig-Gordon model (C-G model) [H. Craig, L.I. Gordon. Deuterium and oxygen 18 variations in the ocean and the marine atmosphere. In Stable Isotopes in Oceanographic Studies and Paleotemperatures, E. Tongiorgi (Ed.), pp. 9-130, Laboratorio di Geologia Nucleare, Pisa (1965).] has been synonymous with the isotope effects associated with the evaporation of water from surface waters, soils, and vegetations, which in turn constitutes a critical component of the global water cycle. On the occasion of the four decades of its successful applications to isotope geochemistry and hydrology, an attempt is made to: (a) examine its physical background within the framework of modern evaporation models, (b) evaluate our current knowledge of the environmental parameters of the C-G model, and (c) comment on a general strategy for the use of these parameters in field applications. Despite its simplistic representation of evaporation processes at the water-air interface, the C-G model appears to be adequate to provide the isotopic composition of the evaporation flux. This is largely due to its nature for representing isotopic compositions (a ratio of two fluxes of different isotopic water molecules) under the same environmental conditions. Among many environmental parameters that are included in the C-G model, accurate description and calculations are still problematic of the kinetic isotope effects that occur in a diffusion-dominated thin layer of air next to the water-air interface. In field applications, it is of importance to accurately evaluate several environmental parameters, particularly the relative humidity and isotopic compositions of the 'free-atmosphere', for a system under investigation over a given time-scale of interest (e.g., hourly to daily to seasonally). With a growing interest in the studies of water cycles of different spatial and temporal scales, including paleoclimate and water resource studies, the importance and utility of the C-G model is also likely to

  20. Effect of Growth Parameters on SnO2 Nanowires Growth by Electron Beam Evaporation Method

    Science.gov (United States)

    Rakesh Kumar, R.; Manjula, Y.; Narasimha Rao, K.

    2018-02-01

    Tin oxide (SnO2) nanowires were synthesized via catalyst assisted VLS growth mechanism by the electron beam evaporation method at a growth temperature of 450 °C. The effects of growth parameters such as evaporation rate of Tin, catalyst film thickness, and different types of substrates on the growth of SnO2 nanowires were studied. Nanowires (NWs) growth was completely seized at higher tin evaporation rates due to the inability of the catalyst particle to initiate the NWs growth. Nanowires diameters were able to tune with catalyst film thickness. Nanowires growth was completely absent at higher catalyst film thickness due to agglomeration of the catalyst film. Optimum growth parameters for SnO2 NWs were presented. Nanocomposites such as Zinc oxide - SnO2, Graphene oxide sheets- SnO2 and Graphene nanosheets-SnO2 were able to synthesize at a lower substrate temperature of 450 °C. These nanocompsoites will be useful in enhancing the capacity of Li-ion batteries, the gas sensing response and also useful in increasing the photo catalytic activity.

  1. Assesing the effect of an olive mill wastewater evaporation pond in Sousse, Tunisia

    Science.gov (United States)

    S'habou, Rakia; Zairi, Moncef; Kallel, Amjed; Aydi, Abdelwaheb; Ben Dhia, Hamed

    2009-08-01

    Olive oil is a typical and valuable agro-industrial product in Mediterranean countries. In Tunisia, olive mill wastewaters (OMW) reach an amount of about 1,000,000 t year-1 and constitute a serious organic pollution risk because of the high chemical oxygen demand values and the presence of phytotoxic and antibacterial polyphenols. OMW have been generally stored in pond sites to be eliminated by natural evaporation or valorised by spreading on cultivated soils or by composting. Many researches on the interactions of OMW with soils at laboratory scale (columns) have been reported, but less attention have been paid to the effect of OMW on soils at field scale. The aim of this work is to investigate an area used for >15 years as an uncontrolled OMW pond site. The transformations of soil properties and groundwater occurring during OMW storage were characterised by the pH, phenolic contents, electrical conductivity (EC), moisture content and organic contents. The soil samples were taken from two borings and compared to those of a control one located near the pond site. Groundwater samples were taken on the accessible and nearest water wells to the evaporation ponds. The permeable silty and sandy layers in the site support the infiltration of OMW near the evaporation ponds. This infiltration has reached a depth of 6 m at a distance of almost 50 m laterally. The results show that the OMW infiltration in the subsoil has affected the pH, EC, organic content, phenolic compounds and the moisture.

  2. Effect of Evaporation Time on Separation Performance of Polysulfone/Cellulose Acetate (PSF/CA) Membrane

    Science.gov (United States)

    Syahbanu, Intan; Piluharto, Bambang; Khairi, Syahrul; Sudarko

    2018-01-01

    Polysulfone and cellulose acetate are common material in separation. In this research, polysulfone/cellulose actetate (PSF/CA) blend membrane was prepared. The aim of this research was to study effect of evaporation time in casting of PSF/CA membrane and its performance in filtration. CA was obtained by acetylation process of bacterial cellulose (BC) from fermentation of coconut water. Fourier Transform Infra Red (FTIR) Spectroscopy was used to examine functional groups of BC, CA and commercial cellulose acetate. Subtitution of acetyl groups determined by titration method. Blend membranes were prepared through phase inversion technique in which composition of PSF/PEG/CA/NMP(%w) was 15/5/5/75. Polyethyleneglycol (PEG) and N-methyl-2-pyrrolidone (NMP) were act as pore forming agent and solvent, respectively. Variation of evaporation times were used as parameter to examine water uptake, flux, and morphology of PSF/CA blend membranes. FTIR spectra of CA show characteristic peak of acetyl group at 1220 cm-1 indicated that BC was acetylated succesfully. Degree of subtitution of BCA was found at 2.62. Highest water flux was performed at 2 bar obtained at 106.31 L.m-2.h-1 at 0 minute variation, and decrease as increasing evaporation time. Morphology of PSF/BCA blend membranes were investigated by Scanning Electron Microscopy (SEM) showed that porous asymetric membrane were formed.

  3. Numerical simulation of the temperature effects on the performance of rotational supercavitating evaporator

    International Nuclear Information System (INIS)

    Zheng, Z Y; Cheng, J P; Li, F C; Zhang, M; Li, Q; Kulagin, V A

    2015-01-01

    With the application of supercavitation effect, a novel device named Rotational Supercavitating Evaporator (RSCE) has been designed for desalination. In order to study the effect of temperature on the performance of RSCE and then direct the experimental study on RSCE for the next step, numerical simulations are conducted on the supercavitating flows in RSCE under different temperatures and rotational speeds. The results show that the rotational speed, resistance moment and mechanical energy consumed by the rotational cavitator under the critical state with the largest supercavity, decrease with the increase of temperature. And the area and volume of the supercavity increase exponentially with the increase of temperature under the same rotational speed

  4. Effect of the thermal evaporation rate of Al cathodes on organic light emitting diodes

    International Nuclear Information System (INIS)

    Shin, Hee Young; Suh, Min Chul

    2014-01-01

    Graphical abstract: - Highlights: • The TOF-SIMS analysis to investigate cathode diffusion during evaporation process. • Performance change of OLEDs prepared with different evaporation rate of Al cathode. • Change of electron transport behavior during thermal evaporation process. - Abstract: The relationship between the thermal evaporation rate of Al cathodes and the device performance of organic light-emitting diodes (OLEDs) was investigated to clarify the source of leakage current. Time-of-flight secondary ion mass spectrometry was applied to identify the diffusion of Li and Al fragments into the underlying organic layer during the thermal evaporation process. We prepared various OLEDs by varying the evaporation rates of the Al cathode to investigate different device performance. Interestingly, the leakage current level decreased when the evaporation rate reached ∼25 Å/s. In contrast, the best efficiency and operational lifetime was obtained when the evaporation rate was 5 Å/s

  5. Effects of biochar addition on evaporation in the five typical Loess Plateau soils

    Science.gov (United States)

    Soil evaporation is the main route of soil moisture loss and often exceeds precipitation in the arid and semi-arid regions of the Loess Plateau. This study was conducted to determine whether biochar addition could reduce soil evaporation in drylands. We measured the evaporative loss in five typical ...

  6. The effect of atoms excited by electron beam on metal evaporation

    CERN Document Server

    Xie Guo Feng; Ying Chun Tong

    2002-01-01

    In atomic vapor laser isotope separation (AVLIS), the metal is heated to melt by electron beams. The vapor atoms may be excited by electrons when flying through the electron beam. The excited atoms may be deexcited by inelastic collision during expansion. The electronic energy transfers translational energy. In order to analyse the effect of reaction between atoms and electron beams on vapor physical parameters, such as density, velocity and temperature, direct-simulation Monte Carlo method (DSMC) is used to simulate the 2-D gadolinium evaporation from long and narrow crucible. The simulation results show that the velocity and temperature of vapor increase, and the density decreases

  7. Numerical investigation of wet-bulb effectiveness and water consumption in one-and two-stage indirect evaporative coolers

    International Nuclear Information System (INIS)

    Moshari, Shahab; Heidarinejad, Ghassem; Fathipour, Aida

    2016-01-01

    Highlights: • Wet bulb effectiveness of indirect/indirect evaporative cooling systems are 76–81%. • Dimensionless water evaporation rate decreases as the primary air flow rate increases. • Water evaporation rate increases with increase of inlet dry bulb temperature. - Abstract: In this study, three configuration for two-stage indirect/indirect evaporative cooling systems (IEC/IEC) were proposed (Type A, Type B and Type C) to determine what configuration produces a better wet-bulb effectiveness (or better energy-saving). For this purpose, six cities with a variety of hot weather conditions with the dry-bulb in range of 31.9–46.66 °C were selected. Results show that under these three configuration, the wet-bulb effectiveness of Type A, Type B and Type C varies over ranges of 62–68%, 76–81% and 85–91% respectively, whereas the effectiveness of a one stage IEC varies over a range of 54–60%. There is a common misconceive belief in the concept of water evaporation rate of an evaporative cooling system, which were fueled by many articles; this belief is, if a cooler consumes less water it is an environmentally friendly cooler for dry areas. A more accurate and practical definition is proposed in this article named Dimensionless Water Evaporation Rate (DWER). The numerical results showed that Type B is the optimum configuration, because of a range of 4–24% DWER saving could be obtained by Type B in comparison with Type C whereas Type B increases the product air up to 32%. As well as IEC, in a counter-flow regenerative evaporative cooler the DWER decreases as the primary airflow rate increases whereas water consumption increases. Moreover, using Type B the index of thermal comfort was investigated which showed that Type B could meet thermal comfort condition in two climatic zones of temperate-dry and hot-dry.

  8. Flash evaporator

    OpenAIRE

    1997-01-01

    A device and method for flash evaporating a reagent includes an evaporation chamber that houses a dome on which evaporation occurs. The dome is solid and of high thermal conductivity and mass, and may be heated to a temperature sufficient to vaporize a specific reagent. The reagent is supplied from an external source to the dome through a nozzle, and may be supplied as a continuous stream, as a shower, and as discrete drops. A carrier gas may be introduced into the evaporation chamber and cre...

  9. Investigation of the effect of rollbond evaporator design on the performance of direct expansion heat pump experimentally

    International Nuclear Information System (INIS)

    Cerit, Emine; Erbay, L. Berrin

    2013-01-01

    Highlights: • Effect of rollbond evaporator design to performance of the DX-SAHP is investigated. • Experiments performed on three identical DX-SAHP systems except evaporator design. • Evaporators’ material is aluminum and R134a is the working fluid. • Empirical correlation derived for system COP in terms of radiation and temperature. • The correlation provides the average deviation of 9% with the experimental data. - Abstract: In this study, the rollbond evaporator design which gives maximum coefficient of performance for the direct expansion solar assisted heat pump (DX-SAHP) water heater is investigated experimentally on the three separate heat pump systems due to the lack of studies on the effect of collector-evaporator design to the system performance. Three DX-SAHP systems are identical except collector-evaporator design. Aluminum is preferred for the evaporator material and R134a as the working fluid. Maximum COP value was obtained as 3.30 for System-1 while COP values for System-2 and System-3 were 3.14 and 2.42 respectively at the same conditions. An empirical correlation which gives the COP value of the System-1, which provides highest COP, with respect to the solar radiation and outdoor temperature of the system has been found using the experimental results obtained during the study. The correlation was found to be in good agreement with the average deviation of 9% with the experimental data

  10. In-situ burning of emulsions: The effects of varying water content and degree of evaporation

    International Nuclear Information System (INIS)

    Bech, C.; Sveum, P.; Buist, I.

    1992-01-01

    In-situ burning of oil is considered to be one of the most promising techniques for rapid removal of large quantities of oil at sea, particularly in ice-infested waters. A series of field experiments was conducted in Spitsbergen, circular basins cut in sea ice, to study the effect of water content, evaporation, thickness of the emulsion layer, and environmental factors on the burn efficiency of Statfjord crude oil and emulsions. Results from the experiments are presented along with preliminary results concerning the dynamics of burning emulsions and the efficiency of conventional and novel igniters. Water-in-oil emulsions with 40% water content could be burned. However, for oils evaporated more than 18% and with a water content of over 20%, conventional gelled gasoline was not a very effective igniter. Ignition success was improved when gelled crude oil was used as the igniter. The results imply that for practical in-situ burning, the igniter technology needs to be improved. 5 refs., 11 figs., 3 tabs

  11. Disposal of olive oil mill wastes in evaporation ponds: effects on soil properties.

    Science.gov (United States)

    Kavvadias, V; Doula, M K; Komnitsas, K; Liakopoulou, N

    2010-10-15

    The most common practice followed in the Med countries for the management of olive oil mill wastes (OMW) involves disposal in evaporation ponds or direct disposal on soil. So far there is lack of reliable information regarding the long-term effects of OMW application on soils. This study assesses the effects of OMW disposal in evaporation ponds on underlying soil properties in the wider disposal site as well as the impacts of untreated OMW application on agricultural soils. In case of active disposal sites, the carbonate content in most soils was decreased, whereas soil EC, as well as Cl(-), SO(4)(2-), PO(4)(3-), NH(4)(+) and particularly K(+) concentrations were substantially increased. Soil pH was only marginally affected. Phenol, total N, available P and PO(4)(3-) concentrations were considerably higher in the upper soil layers in areas adjacent to the ponds. Available B as well as DTPA extractable Cu, Mn, Zn and Fe increased substantially. Most surface soil parameters exhibited increased values at the inactive site 6 years after mill closure and cease of OMW disposal activities but differences were diminished in deeper layers. It is therefore concluded that long-term uncontrolled disposal of raw OMW on soils may affect soil properties and subsequently enhance the risk for groundwater contamination. 2010 Elsevier B.V. All rights reserved.

  12. Streamer Evaporation

    Science.gov (United States)

    Suess, Steven T.; Wang, A. H.; Wu, Shi T.; Nerney, S.

    1998-01-01

    Evaporation is the consequence of slow plasma heating near the tops of streamers where the plasma is only weakly contained by the magnetic field. The form it takes is the slow opening of field lines at the top of the streamer and transient formation of new solar wind. It was discovered in polytropic model calculations, where due to the absence of other energy loss mechanisms in magnetostatic streamers, its ultimate endpoint is the complete evaporation of the streamer. This takes, for plausible heating rates, weeks to months in these models. Of course streamers do not behave this way, for more than one reason. One is that there are losses due to thermal conduction to the base of the streamer and radiation from the transition region. Another is that streamer heating must have a characteristic time constant and depend on the ambient physical conditions. We use our global Magnetohydrodynamics (MHD) model with thermal conduction to examine a few examples of the effect of changing the heating scale height and of making ad hoc choices for how the heating depends on ambient conditions. At the same time, we apply and extend the analytic model of streamers, which showed that streamers will be unable to contain plasma for temperatures near the cusp greater than about 2xl0(exp 6) K. Slow solar wind is observed to come from streamers through transient releases. A scenario for this that is consistent with the above physical process is that heating increases the near-cusp temperature until field lines there are forced open. The subsequent evacuation of the flux tubes by the newly forming slow wind decreases the temperature and heating until the flux tubes are able to reclose. Then, over a longer time scale, heating begins to again refill the flux tubes with plasma and increase the temperature until the cycle repeats itself. The calculations we report here are first steps towards quantitative evaluation of this scenario.

  13. Separate effects tests for GOTHIC condensation and evaporative heat transfer models

    International Nuclear Information System (INIS)

    George, T.L.; Singh, A.

    1994-01-01

    The GOTHIC computer program, under development at EPRI/NAI, is a general purpose thermal hydraulics computer program for design, licensing, safety and operating analysis of nuclear containments and other confinement buildings. The code solves a nine equation model for three dimensional multiphase flow with separate mass, momentum and energy equations for vapor, liquid and drop phases. The vapor phase can be a gas mixture of steam and non-condensing gases. The phase balance equations are coupled by mechanistic and empirical models for interface mass, energy and momentum transfer that cover the entire flow regime from bubbly flow to film/drop flow. A variety of heat transfer correlations are available to model the fluid coupling to active and passive solid conductors. This paper focuses on the application of GOTHIC to two separate effects tests; condensation heat transfer on a vertical flat plate with varying bulk velocity, steam concentration and temperature, and evaporative heat transfer from a hot pool to a dry (superheated) atmosphere. Comparisons with experimental data is included for both tests. Results show the validity of two condensation heat transfer correlations as incorporated into GOTHIC and the interfacial heat and mass transfer models for the range of the experimental test conditions. Comparisons are also made for lumped versus multidimensional modeling for buoyancy controlled flow with evaporative heat transfer. (author). 13 refs., 1 tab., 10 figs

  14. Separate effects tests for GOTHIC condensation and evaporative heat transfer models

    International Nuclear Information System (INIS)

    George, T.L.; Singh, A.

    1996-01-01

    The GOTHIC computer program, under development at NAI for EPRI, is a general purpose thermal hydraulics computer program for design, licensing, safety and operating analysis of nuclear containments and other confinement buildings. The code solves a nine-equation model for three-dimensional multiphase flow with separate mass, momentum and energy equations for vapor, liquid and drop phases. The vapor phase can be a gas mixture of steam and non-condensing gases. The phase balance equations are coupled by mechanistic and empirical models for interface mass, energy and momentum transfer that cover the entire flow regime from bubbly flow to film-drop flow. A variety of heat transfer correlations are available to model the fluid coupling to active and passive solid conductors. This paper focuses on the application of GOTHIC to two separate effects tests: condensation heat transfer on a vertical flat plate with varying bulk velocity, steam concentration and temperature, and evaporative heat transfer from a hot pool to a dry (superheated) atmosphere. Comparisons with experimental data are included for both tests. Results show the validity of two condensation heat transfer correlations as incorporated into GOTHIC and the interfacial heat and mass transfer models for the range of the experimental test conditions. Comparisons are also made for lumped vs. multidimensional modeling for buoyancy-controlled flow with evaporative heat transfer. (orig.)

  15. Effect of cationic/anionic organic surfactants on evaporation induced self assembled tin oxide nanostructured films

    International Nuclear Information System (INIS)

    Khun Khun, Kamalpreet; Mahajan, Aman; Bedi, R.K.

    2011-01-01

    Tin oxide nanostructures with well defined morphologies have been obtained through an evaporation induced self assembly process. The technique has been employed using an ultrasonic nebulizer for production of aersol and its subsequent deposition onto a heated glass substrate. The precursor used for aersol production was modified by introducing cationic and anionic surfactants namely cetyl trimethyl ammonium bromide and sodium dodecyl sulphate respectively. The effect of surfactants on the structural, electrical and optical properties of self assembled tin oxide nanostructures were investigated by using X-ray diffraction, field emission scanning electroscope microscopy, two probe technique and photoluminiscence studies. The results reveal that high concentration of surfactants in the precursor solution leads to reduction in crystallite size with significant changes in the morphology of tin oxide nanostructures. Photoluminiscence studies of the nanostructures show emissions in the visible region which exhibit marked changes in the intensities upon variation of surfactants in the precursor solutions.

  16. Effect of cationic/anionic organic surfactants on evaporation induced self assembled tin oxide nanostructured films

    Energy Technology Data Exchange (ETDEWEB)

    Khun Khun, Kamalpreet [Material Science Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Mahajan, Aman, E-mail: dramanmahajan@yahoo.co.in [Material Science Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Bedi, R.K. [Material Science Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India)

    2011-01-15

    Tin oxide nanostructures with well defined morphologies have been obtained through an evaporation induced self assembly process. The technique has been employed using an ultrasonic nebulizer for production of aersol and its subsequent deposition onto a heated glass substrate. The precursor used for aersol production was modified by introducing cationic and anionic surfactants namely cetyl trimethyl ammonium bromide and sodium dodecyl sulphate respectively. The effect of surfactants on the structural, electrical and optical properties of self assembled tin oxide nanostructures were investigated by using X-ray diffraction, field emission scanning electroscope microscopy, two probe technique and photoluminiscence studies. The results reveal that high concentration of surfactants in the precursor solution leads to reduction in crystallite size with significant changes in the morphology of tin oxide nanostructures. Photoluminiscence studies of the nanostructures show emissions in the visible region which exhibit marked changes in the intensities upon variation of surfactants in the precursor solutions.

  17. Effect of Liquid/Vapour Maldistribution on the Performance of Plate Heat Exchanger Evaporators

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Kærn, Martin Ryhl; Ommen, Torben Schmidt

    2015-01-01

    Plate heat exchangers are often applied as evaporators in industrial refrigeration and heat pump systems. In the design and modelling of such heat exchangers the flow and liquid/vapour distribution is often assumed to be ideal. However, maldistribution may occur and will cause each channel...... to behave differently due to the variation of the mass flux and vapour quality. To evaluate the effect of maldistribution on the performance of plate heat exchangers, a numerical model is developed in which the mass, momentum and energy balances are applied individually to each channel, including suitable...... correlations for heat transfer and pressure drop. The flow distribution on both the refrigerant and secondary side is determined based on equal pressure drop while the liquid/vapour distribution is imposed to the model. Results show that maldistribution may cause up to a 25 % reduction of the overall heat...

  18. Effect of solvent evaporation and coagulation on morphology development of asymmetric membranes

    Science.gov (United States)

    Chandrasekaran, Neelakandan; Kyu, Thein

    2008-03-01

    Miscibility behavior of blends of amorphous polyamide (PA) and polyvinylpyrrolidone (PVP) was studied in relation to membrane formation. Dimethylsulfoxide (DMSO) and water were used as solvent and non-solvent, respectively. Differential scanning calorimetry and cloud point measurements revealed that the binary PA/PVP blends as well as the ternary PA/PVP/DMSO system were completely miscible at all compositions. However, the addition of non-solvent (water) to this ternary system has led to phase separation. Visual turbidity study was used to establish a ternary liquid-liquid phase diagram of the PA-PVP/DMSO/water system. Scanning Electron Microscopy (SEM) showed the development of finger-like and sponge-like cross sectional morphologies during coagulation. Effects of polymer concentration, PA/PVP blend ratio, solvent/non-solvent quality, and evaporation time on the resulting membrane morphology will be discussed.

  19. Effect of evaporation of solvents from one-step, self-etching adhesives

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; Peutzfeldt, Anne; Asmussen, Erik

    2008-01-01

    PURPOSE: To investigate whether and to what extent the bonding capacity of one-step, self-etching adhesives is influenced by the degree to which solvent is evaporated. MATERIALS AND METHODS: Seven one-step, self-etching adhesives were tested (Adper Prompt L-Pop, Clearfil S3 Bond, Futurabond NR, G....... After being stored in water at 37 degrees C for 1 week, the bonded specimens were broken in shear. Failure modes were evaluated under stereomicroscope. RESULTS: Air-blowing duration and brand of adhesive both had an effect on shear bond strength. An interaction was found between adhesive and air...... failures were observed with shorter air-blowing durations. A significant negative correlation between number of adhesive failures and bond strength was found. CONCLUSION: On the basis of this in vitro study, it may be concluded that the one-step, self-etching adhesives evaluated were sensitive to degree...

  20. Effect of refrigerant mal-distribution in fin-and-tube evaporators on system performance

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian; Larsen, Lars Finn Sloth

    2009-01-01

    the condenser is a dynamic moving boundary model. The evaporator model is a dynamic distributed one-dimensional homogeneous equilibrium model, in order to capture the distribution phenomena. Fin-and-tube heat exchangers usually have a complex circuitry, however the evaporator will be simplified to be two...

  1. Silver-Doping Effects and Photostructural Transformation in Evaporated AS2S3 Thin Films.

    Science.gov (United States)

    1982-02-16

    of evaporated silver halide films. The details of the preparation of evaporated films of silver halides are reported by Junod at. al. (41 ) The...1980). 40. M.S. Chang, N.D. Hwang, J.T. Chen, Extended Abstr. Electrochem. Soc., 80-1, 692, (1980). 41. P. Junod , N. MHediger, B. Kilchoy. R. Steiger

  2. Effects of straw mulching on soil evaporation during the soil thawing ...

    Indian Academy of Sciences (India)

    Qiang Fu

    2018-03-27

    Mar 27, 2018 ... Materials and methods. 2.1 Study area ... 110 days, and the frost-free period is approximately. 140 days. ..... flow to the soil surface was sufficient to meet the evaporative ..... Impact of ambient conditions on evaporation from porous media ... through integrated modeling of the atmospheric boundary layer and ...

  3. Effects of Bell Speed and Flow Rate on Evaporation of Water Spray from a Rotary Bell Atomizer

    Directory of Open Access Journals (Sweden)

    Rajan Ray

    2015-05-01

    Full Text Available A phase doppler anemometer (PDA was used to determine the effects of evaporation on water spray for three rotary bell atomizer operational variable parameters: shaping air, bell speed and liquid flow. Shaping air was set at either 200 standard liters per minute (L/min or 300 L/min, bell speed was set to 30, 40 or 50 thousand rotations per minute (krpm and water flow rate was varied between 100, 200 or 300 cubic centimeters per minute (cm3/min. The total evaporation between 22.5 and 37.5 cm from the atomizer (cm3/s was calculated for all the combinations of those variables. Evaporation rate increased with higher flow rate and bell speed but no statistically significant effects were obtained for variable shaping air on interactions between parameters.

  4. Effect of the Heat Flux Density on the Evaporation Rate of a Distilled Water Drop

    Directory of Open Access Journals (Sweden)

    Ponomarev Konstantin

    2016-01-01

    Full Text Available This paper presents the experimental dependence of the evaporation rate of a nondeaerated distilled water drop from the heat flux density on the surfaces of non-ferrous metals (copper and brass. A drop was placed on a heated substrate by electronic dosing device. To obtain drop profile we use a shadow optical system; drop symmetry was controlled by a high-speed video camera. It was found that the evaporation rate of a drop on a copper substrate is greater than on a brass. The evaporation rate increases intensively with raising volume of a drop. Calculated values of the heat flux density and the corresponding evaporation rates are presented in this work. The evaporation rate is found to increase intensively on the brass substrate with raising the heat flux density.

  5. Effect of top soil wettability on water evaporation and plant growth.

    Science.gov (United States)

    Gupta, Bharat; Shah, D O; Mishra, Brijesh; Joshi, P A; Gandhi, Vimal G; Fougat, R S

    2015-07-01

    In general, agricultural soil surfaces being hydrophilic in nature get easily wetted by water. The water beneath the soil moves through capillary effect and comes to the surface of the soil and thereafter evaporates into the surrounding air due to atmospheric conditions such as sunlight, wind current, temperature and relative humidity. To lower the water loss from soil, an experiment was designed in which a layer of hydrophobic soil was laid on the surface of ordinary hydrophilic soil. This technique strikingly decreased loss of water from the soil. The results indicated that the evaporation rate significantly decreased and 90% of water was retained in the soil in 83 h by the hydrophobic layer of 2 cm thickness. A theoretical calculation based on diffusion of water vapour (gas phase) through hydrophobic capillaries provide a meaningful explanation of experimental results. A greater retention of water in the soil by this approach can promote the growth of plants, which was confirmed by growing chick pea (Cicer arietinum) plants and it was found that the length of roots, height of shoot, number of branches, number of leaves, number of secondary roots, biomass etc. were significantly increased upon covering the surface with hydrophobic soil in comparison to uncovered ordinary hydrophilic soil of identical depth. Such approach can also decrease the water consumption by the plants particularly grown indoors in residential premises, green houses and poly-houses etc. and also can be very useful to prevent water loss and enhance growth of vegetation in semi-arid regions. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Effects of Salt Accumulation in Soil by Evaporation on Unsaturated Soil Hydraulic Properties

    Science.gov (United States)

    Liu, Y.; Liu, Q.

    2017-12-01

    Soil salinization is one type of soil degradation caused by saline groundwater evaporation. Salt accumulation in the soil will change the pore structure of soil, which should change the unsaturated soil hydraulic properties including the soil water characteristic curve (SWCC). To investigate the effect of salt accumulation on the SWCC and find the best suitable SWCC model to characterize the relationship of soil moisture and soil matrix potential, we have conducted laboratory SWCC experiments with the soil columns saturated by NaCl solution with different concentration (deionized water, 3 g/L, 15 g/L, 50 g/L, 100 g/L and 200 g/L). As the concentration of initial solution increases, the matrix potential corresponding to the same moisture increases. As the water was evaporated, the salt would precipitate in soil continuously, which would decrease the porosity of soils and increase the negative pressure of soils. With higher initial concentration, the more salt accumulation caused the more residual water content in the soils. For van Genuchten-Mualem model, the residual water contents θr were 0.0159, 0.0181, 0.0182, 0.0328, 0.0312, 0.0723, 0.0864 in the columns initially saturated by deionized water, 3 g/L, 15 g/L, 50 g/L, 100 g/L and 200 g/L, respectively. The van Genuchten-Mualem model, Fredlund-Xing model, Gardern model, Mckee-Bumb model and Brooks-Corey model were fitted by MATLAB with the experiments data, and the fitted coefficients were compared. The Fredlund-Xing model has the best fitting coefficients and the calculated value was consistent with the observed data.

  7. Decomposition of thermally unstable substances in film evaporators

    Energy Technology Data Exchange (ETDEWEB)

    Matz, G

    1982-10-01

    It is widely known that film evaporators are considered to permit really gentle evaporation of heat-sensitive substances. Nevertheless, decomposition of such substance still occurs to an extent depending upon the design and operation of the evaporator. In the following a distinction is made between evaporators with films not generated mechanically, namely the long tube evaporator (lTE) or climbing film evaporator, the falling film evaporator (FFE) and the multiple phase helical tube (MPT) or helical coil evaporators (TFE). Figs 1 and 2 illustrate the mode of operation. A theory of the decomposition of thermally unstable substances in these evaporators is briefly outlined and compared with measurements. Such a theory cannot be developed without any experimental checks; on the other hand, meausrements urgently need a theoretical basis if only to establish what actually has to be measured. All experiments are made with a system of readily adjustable decomposability, namely with aqueous solutions of saccharose; the thermal inversion of this compound can be controlled by addition of various amounts or concentrations of hydrochloric acid. In the absence of any catalysis by hydrochloric acid, the decomposition rates within in the temperature interval studied (60-130/sup 0/C) are so low that the experiments would take much too long and determination of the concentration differences (generally by polarimetric methods) would be very complicated. Such slight effects would also be very unfavourable for comparison with theory. (orig.)

  8. Effects of heating method and conditions on the evaporation rate and quality attributes of black mulberry (Morus nigra) juice concentrate.

    Science.gov (United States)

    Fazaeli, Mahboubeh; Hojjatpanah, Ghazale; Emam-Djomeh, Zahra

    2013-02-01

    Black mulberry juice was concentrated by different heating methods, including conventional heating and microwave heating, at different operational pressures (7.3, 38.5 and 100 kPa). The effects of each method on evaporation rate, quality attributes of concentrated juice were investigated. The final juice concentration of 42° Brix was achieved in 140, 120, and 95 min at 100, 38.5, and 7.3 kPa respectively by using a rotary evaporator. Applying microwave energy decreased required times to 115, 95, and 60 min. The changes in color, anthocyanin content during the concentration processes were investigated. Hunter parameters (L, a, and b) were measured to estimate the intensity of color loss. All Hunter color parameters decreased with time. Results showed that the degradation of color and consequently anthocyanins, was more pronounced in rotary evaporation compared to microwave heating method.

  9. The effect of Meibomian lipids and tear proteins on evaporation rate under controlled in vitro conditions.

    Science.gov (United States)

    Herok, George Henryk; Mudgil, Poonam; Millar, Thomas James

    2009-07-01

    The lipid layer of the tear film is associated with preventing evaporative loss. The ability of human Meibomian lipids to reduce evaporation in vitro was tested. Films of human or animal Meibomian lipids or mixtures of cholesterol and phosphatidylcholine were spread on the surface of either artificial buffer or on whole tears and placed on a mass balance that was enclosed in a sealed chamber. The temperature was adjusted to 37 degrees C and gas flow was controlled. Increasing the amounts of Meibomian lipids gave a very small reduction in evaporation. It was concluded from these in vitro experiments that prevention of evaporation from the tear film is not due to the Meibomian lipids alone, but is more likely to be due to a complex interaction between components of the aqueous and the Meibomian lipids.

  10. Study the Effect of Imposing Surfactants toward the Evaporation of Low Molecular Weight Alcohol

    OpenAIRE

    Mohammad , H.H.; Sharifuddin Md. , Zain; Rashid Atta , Khan; Khalisanni , Khalid

    2013-01-01

    International audience; In this paper, Reversed-Flow Gas Chromatography (RF-GC) is utilized to investigate the evaporation of low molecular weight alcohol. Evaporation rates as well as the diffusion rates of methanol are determined with a surfactant monolayer on the surface of the liquid; while nitrogen acts as carrier gas, at 313 K. The precision (>99.9%) and accuracy of this investigation demonstrates the potential of current methodologies for environmental impact studies; this is further v...

  11. Study the Effect of Imposing Surfactants toward the Evaporation of Low Molecular Weight Alcohol

    OpenAIRE

    H.H., Mohammad; Zain, Sharifuddin Mohd; Khan, Rashid Atta; Khalid, Khalisanni

    2017-01-01

    In this paper, Reversed-Flow Gas Chromatography (RF-GC) is utilized to investigate the evaporation of low molecular weight alcohol. Evaporation rates as well as the diffusion rates of methanol are determined with a surfactant monolayer on the surface of the liquid; while nitrogen acts as carrier gas, at 313 K. The precision (>99.9%) and accuracy of this investigation demonstrates the potential of current methodologies for environmental impact studies; this is further verified when the results...

  12. Morphological Evolution of Block Copolymer Particles: Effect of Solvent Evaporation Rate on Particle Shape and Morphology.

    Science.gov (United States)

    Shin, Jae Man; Kim, YongJoo; Yun, Hongseok; Yi, Gi-Ra; Kim, Bumjoon J

    2017-02-28

    Shape and morphology of polymeric particles are of great importance in controlling their optical properties or self-assembly into unusual superstructures. Confinement of block copolymers (BCPs) in evaporative emulsions affords particles with diverse structures, including prolate ellipsoids, onion-like spheres, oblate ellipsoids, and others. Herein, we report that the evaporation rate of solvent from emulsions encapsulating symmetric polystyrene-b-polybutadiene (PS-b-PB) determines the shape and internal nanostructure of micron-sized BCP particles. A distinct morphological transition from the ellipsoids with striped lamellae to the onion-like spheres was observed with decreasing evaporation rate. Experiments and dissipative particle dynamics (DPD) simulations showed that the evaporation rate affected the organization of BCPs at the particle surface, which determined the final shape and internal nanostructure of the particles. Differences in the solvent diffusion rates in PS and PB at rapid evaporation rates induced alignment of both domains perpendicular to the particle surface, resulting in ellipsoids with axial lamellar stripes. Slower evaporation rates provided sufficient time for BCP organization into onion-like structures with PB as the outermost layer, owing to the preferential interaction of PB with the surroundings. BCP molecular weight was found to influence the critical evaporation rate corresponding to the morphological transition from ellipsoid to onion-like particles, as well as the ellipsoid aspect ratio. DPD simulations produced morphologies similar to those obtained from experiments and thus elucidated the mechanism and driving forces responsible for the evaporation-induced assembly of BCPs into particles with well-defined shapes and morphologies.

  13. Effect of material flexibility on the thermodynamics and kinetics of hydrophobically induced evaporation of water.

    Science.gov (United States)

    Altabet, Y Elia; Haji-Akbari, Amir; Debenedetti, Pablo G

    2017-03-28

    The evaporation of water induced by confinement between hydrophobic surfaces has received much attention due to its suggested functional role in numerous biophysical phenomena and its importance as a general mechanism of hydrophobic self-assembly. Although much progress has been made in understanding the basic physics of hydrophobically induced evaporation, a comprehensive understanding of the substrate material features (e.g., geometry, chemistry, and mechanical properties) that promote or inhibit such transitions remains lacking. In particular, comparatively little research has explored the relationship between water's phase behavior in hydrophobic confinement and the mechanical properties of the confining material. Here, we report the results of extensive molecular simulations characterizing the rates, free energy barriers, and mechanism of water evaporation when confined between model hydrophobic materials with tunable flexibility. A single-order-of-magnitude reduction in the material's modulus results in up to a nine-orders-of-magnitude increase in the evaporation rate, with the corresponding characteristic time decreasing from tens of seconds to tens of nanoseconds. Such a modulus reduction results in a 24-orders-of-magnitude decrease in the reverse rate of condensation, with time scales increasing from nanoseconds to tens of millions of years. Free energy calculations provide the barriers to evaporation and confirm our previous theoretical predictions that making the material more flexible stabilizes the confined vapor with respect to liquid. The mechanism of evaporation involves surface bubbles growing/coalescing to form a subcritical gap-spanning tube, which then must grow to cross the barrier.

  14. Effects of climatic seasonality on the isotopic composition of evaporating soil waters

    Directory of Open Access Journals (Sweden)

    P. Benettin

    2018-05-01

    Full Text Available Stable water isotopes are widely used in ecohydrology to trace the transport, storage, and mixing of water on its journey through landscapes and ecosystems. Evaporation leaves a characteristic signature on the isotopic composition of the water that is left behind, such that in dual-isotope space, evaporated waters plot below the local meteoric water line (LMWL that characterizes precipitation. Soil and xylem water samples can often plot below the LMWL as well, suggesting that they have also been influenced by evaporation. These soil and xylem water samples frequently plot along linear trends in dual-isotope space. These trend lines are often termed "evaporation lines" and their intersection with the LMWL is often interpreted as the isotopic composition of the precipitation source water. Here we use numerical experiments based on established isotope fractionation theory to show that these trend lines are often by-products of the seasonality in evaporative fractionation and in the isotopic composition of precipitation. Thus, they are often not true evaporation lines, and, if interpreted as such, can yield highly biased estimates of the isotopic composition of the source water.

  15. Evaporator bulb

    International Nuclear Information System (INIS)

    Stoll, W.

    1977-01-01

    In order to prevent the hazard of a possible excursion in an evaporator bulb for radioactive liquids there is provided in the bottom of the vessel a recess filled with a neutron-absorbing and moderating material. The bottom drain pipe is coming out sideways and connected with a heated pipe feeding above into the vessel tangentially. (TK) [de

  16. Evaporating firewalls

    Science.gov (United States)

    Van Raamsdonk, Mark

    2014-11-01

    In this note, we begin by presenting an argument suggesting that large AdS black holes dual to typical high-energy pure states of a single holographic CFT must have some structure at the horizon, i.e. a fuzzball/firewall, unless the procedure to probe physics behind the horizon is state-dependent. By weakly coupling the CFT to an auxiliary system, such a black hole can be made to evaporate. In a case where the auxiliary system is a second identical CFT, it is possible (for specific initial states) that the system evolves to precisely the thermofield double state as the original black hole evaporates. In this case, the dual geometry should include the "late-time" part of the eternal AdS black hole spacetime which includes smooth spacetime behind the horizon of the original black hole. Thus, if a firewall is present initially, it evaporates. This provides a specific realization of the recent ideas of Maldacena and Susskind that the existence of smooth spacetime behind the horizon of an evaporating black hole can be enabled by maximal entanglement with a Hawking radiation system (in our case the second CFT) rather than prevented by it. For initial states which are not finely-tuned to produce the thermofield double state, the question of whether a late-time infalling observer experiences a firewall translates to a question about the gravity dual of a typical high-energy state of a two-CFT system.

  17. Effects of Evaporation Pressure and the Variety of Cane on the Quality of Sugar Honey and Panela

    Directory of Open Access Journals (Sweden)

    Luz Esperanza Prada Forero

    2015-07-01

    Full Text Available When multi-effect evaporators (EME are implemented at the process of panela —besides of technological adjustment— to maintain the quality of the product is also required. This state unveiled a technolog y gap, and issues such as the contribution of compositional differences in the varieties of cane on panela. To fill part of this technological gap, the objective of this work is to determine the effect of pressure evaporation and the varieties of cane on quality of honey and panela. To achieve this, the evaporation pressure and sugarcane varieties in one experimental design completely randomized with 4x3 factorial arrangement and four replications was implemented: varieties CC 85-46, RD 75-11 andPR 61-632, without flocculant, without coadjuvant and was evaporated with a heat flux of 27,778 kW/m2 and without antifoam. The results showed a similar behavior for the studied sugarcane varieties. So honeys and panelas in the pressurized system presented dark coloration, reddish tone, high turbidity, a glycoside coefficient between 60 % and 70 % and they did not solidified. Honeys and panelas in vacuum systems presented a greater turbidity, clear colorations, yellowish tones, and good solidification and coefficients glycosides under 12 %.

  18. Effects of solvent evaporation time on immediate adhesive properties of universal adhesives to dentin.

    Science.gov (United States)

    Luque-Martinez, Issis V; Perdigão, Jorge; Muñoz, Miguel A; Sezinando, Ana; Reis, Alessandra; Loguercio, Alessandro D

    2014-10-01

    To evaluate the microtensile bond strengths (μTBS) and nanoleakage (NL) of three universal or multi-mode adhesives, applied with increasing solvent evaporation times. One-hundred and forty caries-free extracted third molars were divided into 20 groups for bond strength testing, according to three factors: (1) Adhesive - All-Bond Universal (ABU, Bisco, Inc.), Prime&Bond Elect (PBE, Dentsply), and Scotchbond Universal Adhesive (SBU, 3M ESPE); (2) Bonding strategy - self-etch (SE) or etch-and-rinse (ER); and (3) Adhesive solvent evaporation time - 5s, 15s, and 25s. Two extra groups were prepared with ABU because the respective manufacturer recommends a solvent evaporation time of 10s. After restorations were constructed, specimens were stored in water (37°C/24h). Resin-dentin beams (0.8mm(2)) were tested at 0.5mm/min (μTBS). For NL, forty extracted molars were randomly assigned to each of the 20 groups. Dentin disks were restored, immersed in ammoniacal silver nitrate, sectioned and processed for evaluation under a FESEM in backscattered mode. Data from μTBS were analyzed using two-way ANOVA (adhesive vs. drying time) for each strategy, and Tukey's test (α=0.05). NL data were computed with non-parametric tests (Kruskal-Wallis and Mann-Whitney tests, α=0.05). Increasing solvent evaporation time from 5s to 25s resulted in statistically higher mean μTBS for all adhesives when used in ER mode. Regarding NL, ER resulted in greater NL than SE for each of the evaporation times regardless of the adhesive used. A solvent evaporation time of 25s resulted in the lowest NL for SBU-ER. Residual water and/or solvent may compromise the performance of universal adhesives, which may be improved with extended evaporation times. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  19. Annealing effects on electron-beam evaporated Al2O3 films

    International Nuclear Information System (INIS)

    Shang Shuzhen; Chen Lei; Hou Haihong; Yi Kui; Fan Zhengxiu; Shao Jianda

    2005-01-01

    The effects of post-deposited annealing on structure and optical properties of electron-beam evaporated Al 2 O 3 single layers were investigated. The films were annealed in air for 1.5 h at different temperatures from 250 to 400 deg. C. The optical constants and cut-off wavelength were deduced. Microstructure of the samples was characterized by X-ray diffraction (XRD). Profile and surface roughness measurement instrument was used to determine the rms surface roughness. It was found that the cut-off wavelength shifted to short wavelength as the annealing temperature increased and the total optical loss decreased. The film structure remained amorphous even after annealing at 400 deg. C temperature and the samples annealed at higher temperature had the higher rms surface roughness. The decreasing total optical loss with annealing temperature was attributed to the reduction of absorption owing to oxidation of the film by annealing. Guidance to reduce the optical loss of excimer laser mirrors was given

  20. Annealing effects on electron-beam evaporated Al 2O 3 films

    Science.gov (United States)

    Shuzhen, Shang; Lei, Chen; Haihong, Hou; Kui, Yi; Zhengxiu, Fan; Jianda, Shao

    2005-04-01

    The effects of post-deposited annealing on structure and optical properties of electron-beam evaporated Al 2O 3 single layers were investigated. The films were annealed in air for 1.5 h at different temperatures from 250 to 400 °C. The optical constants and cut-off wavelength were deduced. Microstructure of the samples was characterized by X-ray diffraction (XRD). Profile and surface roughness measurement instrument was used to determine the rms surface roughness. It was found that the cut-off wavelength shifted to short wavelength as the annealing temperature increased and the total optical loss decreased. The film structure remained amorphous even after annealing at 400 °C temperature and the samples annealed at higher temperature had the higher rms surface roughness. The decreasing total optical loss with annealing temperature was attributed to the reduction of absorption owing to oxidation of the film by annealing. Guidance to reduce the optical loss of excimer laser mirrors was given.

  1. Effect of internal flow and evaporation on hydrogel assembly process at droplet interface

    Science.gov (United States)

    Kang, Giho; Seong, Baekhoon; Gim, Yeonghyeon; Ko, Han Seo; Byun, Doyoung

    2017-11-01

    Recently, controlling the behavior of nanoparticles inside liquid droplet has been widely studied. There have been many reports about the mechanism of the nanoparticles assembly and fabrication of a thin film on a substrate. However, the assembly mechanism at a liquid-air interface has not been clearly understood to form polymer chains into films. Herein, we investigated the role of internal flow on the thin film assembly process at the interface of the hydrogel droplet. The internal fluid flow during the formation of the hydrogel film was visualized systematically using micro-PIV (Particle image velocimetry) technique at various temperatures. We show that the buoyancy effect and convection flow induced by heat can affect the film morphology and its mechanical characteristics. Due to the accelerated fluid flow inside the droplet and evaporation flux, densely assembled hydrogel film was able to be formed. Film strength was increased 24% with temperature increase from 40 to 80 degrees Celsius. We expect our investigations could be applied to many applications such as self-assembly of planar structures at the interface in coating and printing process. The support from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2015R1A2A1A05001829) is acknowledged.

  2. Effects of evaporative cooling on reproductive performance and milk production of dairy cows in hot wet conditions

    Science.gov (United States)

    Khongdee, S.; Chaiyabutr, N.; Hinch, G.; Markvichitr, K.; Vajrabukka, C.

    2006-05-01

    Fourteen animals of second and third lactation of Thai Friesian crossbred cows (87.5% Friesian × 12.5% Bos indicus) located at Sakol Nakhon Research and Breeding Centre, Department of Livestock Development, Ministry of Agriculture and Cooperatives, were divided randomly into two groups of seven each to evaluate the effects of evaporative cooling on reproductive and physiological traits under hot, humid conditions. Results indicated that installation of evaporating cooling in the open shed gave a further improvement in ameliorating heat stress in dairy cows in hot-wet environments by utilising the low humidity conditions that naturally occur during the day. The cows housed in an evaporatively cooled environment had both a rectal temperature and respiration rate (39.09°C, 61.39 breaths/min, respectively) significantly lower than that of the non-cooled cows (41.21°C; 86.87 breaths/min). The former group also had higher milk yield and more efficient reproductive performance (pregnancy rate and reduced days open) than the latter group. It is suggested that the non-evaporatively cooled cows did not gain benefit from the naturally lower heat stress during night time.

  3. Liquid evaporation process and evaporator

    International Nuclear Information System (INIS)

    Bergey, Claude; Ravenel, Jacques.

    1975-01-01

    The process described enables a liquid to be evaporated rapidly without any projection. A jet of hot gas is applied to the liquid, the power and angle of the jet being chosen so as to spin the liquid. It is particularly used in the case of radioactive products [fr

  4. Study on the Effects of Evaporation and Condensation on the Underfloor Space of Japanese Detached Houses Using CFD Analysis

    Directory of Open Access Journals (Sweden)

    Wonseok Oh

    2017-06-01

    Full Text Available The purpose of this study is to determine the effects of evaporation and condensation on the underfloor space of Japanese detached houses. In this underfloor space, natural ventilation is applied. A typical Japanese wooden detached house is raised 0.3–0.5 m over an underfloor space made of concrete. The bottom of the underfloor space is usually paved with concrete, and the ceiling which is directly underneath the indoor occupant zone is made of wood. Computational fluid dynamics (CFD analysis is applied to calculate the rates of the evaporation and condensation generated inside the underfloor under two conditions, namely, a constant (fixed outdoor environmental condition and a fluctuating environmental condition. In the constant condition, we verified the effects of the outdoor humidity, ventilation rate, and ratio of wetted surface (RWS, ω on the evaporation and condensation inside the underfloor space. In this condition, the rate of evaporation and condensation was quantified considering the varying outdoor humidity between 0 to 100%, and the RWS (ω = 1 or 0. In addition, the influence of the different ventilation rates at 1.0 m/s for normal and 0.05 m/s for stagnant wind velocities were confirmed. Under fluctuating environmental conditions, the outdoor conditions change for 24 h, so the RWS varies. Therefore, the rate of evaporation and condensation, the amount of the condensed water, and the area of condensation were confirmed. The results were as follows: with a high airflow rate on the underfloor space, the evaporation and condensation phenomenon occurs continuously and is easily affected by outdoor humidity, while under low airflow rate conditions, only the condensation appeared steadily. If the wind velocity is strong, the convective mass transfer on a surface becomes large. In a condition of the outdoor humidity and the airflow rate on underfloor are high, condensation mainly occurs in a corner of the underfloor space due to high

  5. Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

    Science.gov (United States)

    Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

    Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

  6. Evaluation of evaporation coefficient for micro-droplets exposed to low pressure: A semi-analytical approach

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Prodyut R., E-mail: pchakraborty@iitj.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Jodhpur, 342011 (India); Hiremath, Kirankumar R., E-mail: k.r.hiremath@iitj.ac.in [Department of Mathematics, Indian Institute of Technology Jodhpur, 342011 (India); Sharma, Manvendra, E-mail: PG201283003@iitj.ac.in [Defence Laboratory Jodhpur, Defence Research & Development Organisation, 342011 (India)

    2017-02-05

    Evaporation rate of water is strongly influenced by energy barrier due to molecular collision and heat transfer limitations. The evaporation coefficient, defined as the ratio of experimentally measured evaporation rate to that maximum possible theoretical limit, varies over a conflicting three orders of magnitude. In the present work, a semi-analytical transient heat diffusion model of droplet evaporation is developed considering the effect of change in droplet size due to evaporation from its surface, when the droplet is injected into vacuum. Negligible effect of droplet size reduction due to evaporation on cooling rate is found to be true. However, the evaporation coefficient is found to approach theoretical limit of unity, when the droplet radius is less than that of mean free path of vapor molecules on droplet surface contrary to the reported theoretical predictions. Evaporation coefficient was found to reduce rapidly when the droplet under consideration has a radius larger than the mean free path of evaporating molecules, confirming the molecular collision barrier to evaporation rate. The trend of change in evaporation coefficient with increasing droplet size predicted by the proposed model will facilitate obtaining functional relation of evaporation coefficient with droplet size, and can be used for benchmarking the interaction between multiple droplets during evaporation in vacuum.

  7. Evaluation of evaporation coefficient for micro-droplets exposed to low pressure: A semi-analytical approach

    International Nuclear Information System (INIS)

    Chakraborty, Prodyut R.; Hiremath, Kirankumar R.; Sharma, Manvendra

    2017-01-01

    Evaporation rate of water is strongly influenced by energy barrier due to molecular collision and heat transfer limitations. The evaporation coefficient, defined as the ratio of experimentally measured evaporation rate to that maximum possible theoretical limit, varies over a conflicting three orders of magnitude. In the present work, a semi-analytical transient heat diffusion model of droplet evaporation is developed considering the effect of change in droplet size due to evaporation from its surface, when the droplet is injected into vacuum. Negligible effect of droplet size reduction due to evaporation on cooling rate is found to be true. However, the evaporation coefficient is found to approach theoretical limit of unity, when the droplet radius is less than that of mean free path of vapor molecules on droplet surface contrary to the reported theoretical predictions. Evaporation coefficient was found to reduce rapidly when the droplet under consideration has a radius larger than the mean free path of evaporating molecules, confirming the molecular collision barrier to evaporation rate. The trend of change in evaporation coefficient with increasing droplet size predicted by the proposed model will facilitate obtaining functional relation of evaporation coefficient with droplet size, and can be used for benchmarking the interaction between multiple droplets during evaporation in vacuum.

  8. Lagrangian Modeling of Evaporating Sprays at Diesel Engine Conditions: Effects of Multi-Hole Injector Nozzles With JP-8 Surrogates

    Science.gov (United States)

    2014-05-01

    Lagrangian Modeling of Evaporating Sprays at Diesel Engine Conditions: Effects of Multi-Hole Injector Nozzles With JP-8 Surrogates by L...efficiency. In this study, three-dimensional numerical simulations of single and two-hole injector nozzles under diesel conditions are conducted to...numerical simulations of single and two-hole injector nozzles under diesel conditions are conducted to study the spray behavior and the effect of

  9. Design and Modelling of Water Chilling Production System by the Combined Effects of Evaporation and Night Sky Radiation

    Directory of Open Access Journals (Sweden)

    Ahmed Y. Taha Al-Zubaydi

    2014-01-01

    Full Text Available The design and mathematical modelling of thermal radiator panel to be used primarily to measure night sky radiation wet coated surface is presented in this paper. The panel consists of an upper dry surface coated aluminium sheet laminated to an ethylene vinyl acetate foam backing block as an insulation. Water is sprayed onto the surface of the panel so that an evaporative cooling effect is gained in addition to the radiation effect; the surface of a panel then is wetted in order to study and measure the night sky radiation from the panel wet surface. In this case, the measuring water is circulated over the upper face of this panel during night time. Initial TRNSYS simulations for the performance of the system are presented and it is planned to use the panel as calibrated instruments for discriminating between the cooling effects of night sky radiation and evaporation.

  10. Effect of gasoline/methanol blends on motorcycle emissions: Exhaust and evaporative emissions

    Science.gov (United States)

    Li, Lan; Ge, Yunshan; Wang, Mingda; Li, Jiaqiang; Peng, Zihang; Song, Yanan; Zhang, Liwei

    2015-02-01

    The emission characteristics of motorcycles using gasoline and M15 (consisting of 85% gasoline and 15% methanol by volume) were investigated in this article. Exhaust and evaporative emissions, including regulated and unregulated emissions, of three motorcycles were investigated on the chassis dynamometer over the Urban Driving Cycle (UDC) and in the Sealed Housing for Evaporative Determination (SHED), respectively. The regulated emissions were detected by an exhaust gas analyzer directly. The unregulated emissions, including carbonyls, volatile organic compounds (VOCs) and methanol, were sampled through battery-operated air pumps using tubes coated with 2,4-dintrophenylhydrazine (DNPH), Tenax TA and silica gel, respectively. The experimental results showed that, for exhaust emission, compared with those from gasoline fueled motorcycles, the concentration of total hydrocarbons (THC) and CO from motorcycles fueled with M15 decreased by 11%-34.5% and 63%-84% respectively, while the concentration of NOx increased by 76.9%-107.7%. Compared with those from gasoline fueled motorcycles, BTEX from motorcycles fueled with M15 decreased by 16%-60% while formaldehyde increased by 16.4%-52.5%. For evaporative emission, diurnal losses were more than hot soak losses and turned out to be dominated in evaporative emissions. In addition, compared with gasoline fueling motorcycles, the evaporative emissions of THC, carbonyls and VOCs from motorcycles fueled with M15 increased by 11.7%-37%, 38%-45% and 16%-42%, respectively. It should be noted that the growth rate of methanol was as high as 297%-1429%. It is important to reduce the evaporative emissions of methanol fueling motorcycles.

  11. Effect of thickness on optical properties of thermally evaporated SnS films

    International Nuclear Information System (INIS)

    Selim, M.S.; Gouda, M.E.; El-Shaarawy, M.G.; Salem, A.M.; Abd El-Ghany, W.A.

    2013-01-01

    The effect of film thickness on the structure and optical properties of thermally evaporated SnS film has been studied. SnS films with different thicknesses in the range 152–585 nm were deposited onto clean glass substrates at room temperature. X-ray diffraction study revealed that SnS films of thickness ≥ 283 nm are crystalline, whereas films of lower thickness exhibit poor crystalline with more amorphous background. The crystalline nature of the lower film thickness has been confirmed using transmission electron microscope and the corresponding electron diffraction pattern. The thicker film samples showed nearly stoichiometric chemical composition; however, thinner samples are deficient in S and rich in Sn. The optical property of the deposited films has been investigated in the wavelength range 350–2500 nm. The refractive index increases notably with increasing film thickness. The refractive index for the investigated film thicknesses are adequately described by the effective-single-oscillator model. The static refractive index and the static dielectric constant have been calculated. Analysis of the optical absorption coefficient revealed the presence of direct optical transition and the corresponding band gap values were found to decrease as the film thickness increases. - Highlights: ► X-ray diffraction was used to study the structure of SnS films. ► Transmission electron microscope confirms the crystalline state of SnS films. ► The refractive index increases notably with increasing the film thickness. ► The optical band gap of SnS films decreases with increasing film thickness

  12. Optimal control of evaporator and washer plants

    International Nuclear Information System (INIS)

    Niemi, A.J.

    1989-01-01

    Tests with radioactive tracers were used for experimental analysis of a multiple-effect evaporator plant. The residence time distribution of the liquor in each evaporator was described by one or two perfect mixers with time delay and by-pass flow terms. The theoretical model of a single evaporator unit was set up on the basis of its instantaneous heat and mass balances and such models were fitted to the test data. The results were interpreted in terms of physical structures of the evaporators. Further model parameters were evaluated by conventional step tests and by measurements of process variables at one or more steady states. Computer simulation and comparison with the experimental results showed that the model produces a satisfactory response to solids concentration input and could be extended to cover the steam feed and liquor flow inputs. An optimal feedforward control algorithm was developed for a two unit, co-current evaporator plant. The control criterion comprised the deviations of the final solids content of liquor and the consumption of fresh steam, from their optimal steady-state values. In order to apply the algorithm, the model of the solids in liquor was reduced to two nonlinear differential equations. (author)

  13. Laboratory study on the cooling effect of flash water evaporative cooling technology for ventilation and air-conditioning of buildings

    DEFF Research Database (Denmark)

    Fang, Lei; Yuan, Shu; Yang, Jianrong

    2016-01-01

    in warm/hot and dry environment where dehumidification of outdoor air is not needed. A laboratory experiment was designed and conducted to evaluate the cooling effectiveness of this technology. The experiment was conducted in a twin-climate chamber. One chamber simulated warm/hot and dry outdoor...... evaporation. Two outdoor summer climates were simulated in the study, i.e. the design summer climate of Las Vegas and the extreme summer climate of Copenhagen represented hot/dry and warm/dry climates. The results showed that the flash evaporative cooling technology, a simple and green cooling technology......, is effective for ventilation and air-conditioning in warm/hot and dry climate zones. The technology can provide fresh outdoor air with a temperature of 4 to 7 °C lower than room air temperature....

  14. Effect of refrigeration lubricants on the heat transfer performance in the microfin tube evaporator

    Energy Technology Data Exchange (ETDEWEB)

    Cho, K N; Tae, S J [Sung Kyun Kwan University, Seoul (Korea)

    1999-01-01

    The present study experimentally investigated the defect of refrigeration lubricant on the heat transfer performance in the straight sections and U-bend of a microfin tube evaporator by using R-22/mineral oil and R-407C/POE oil. The apparatus consisted of test section with U-bend, preheater, condenser, oil injection and sampling devices, magnetic pump, mass flow meter etc. The experimental parameters were oil concentration of 0 to 5 wt%, inlet quality of 0.1 to 0.5, mass flux of 219 and 400 kg/m{sup 2}s and heat flux of 10 and 20 kw/m{sup 2}. The effects of parameters on the heat transfer coefficients were large in the order of inlet quality, mass flux and heat flux as oil concentration got increased. As oil concentration was increased, heat transfer coefficients were continuously decreased for R-22 and increased by 3% up to the concentration of 1% and then decreased for R-407C under the condition of large inlet quality, and small mass flux and heat flux. But, the heat transfer coefficients were increased up to the opposite conditions. The variation of enhancement factors for R-407C refrigerants under the opposite conditions. The variation of enhancement factors for R-407C was under 50% of that for R-22 and the variation with respect to the positions in the test section was small. The pressure drops were increased for both R-22 and R-407C refrigerants as oil concentration was increased. The pressure drops for R-407C were smaller by the maximum of 18% than those for R-22. 12 refs., 1 tab., 14 figs.

  15. Effects of substrate temperature and post-deposition anneal on properties of evaporated cadmium telluride films

    International Nuclear Information System (INIS)

    Bacaksiz, E.; Basol, B.M.; Altunbas, M.; Novruzov, V.; Yanmaz, E.; Nezir, S.

    2007-01-01

    The effects of substrate temperature and post-deposition heat treatment steps on the morphology, structural, optical and electrical properties of thin film CdTe layers grown by vacuum evaporation were investigated. Scanning electron microscopy and X-ray diffraction (XRD) techniques were employed to study the structural changes. It was observed that the grain sizes and morphologies of as-deposited layers were similar for substrate temperatures of - 173 deg. C and - 73 deg. C. However, CdTe films produced at a substrate temperature of 27 deg. C had substantially larger grain size and clearly facetted morphology. Annealing at 200-400 deg. C in air did not cause any appreciable grain growth in any of the films irrespective of their growth temperature. However, annealing at 400 deg. C reduced faceting in all cases and initiated fusing between grains. XRD studies showed that this behavior after annealing at 400 deg. C coincided with an onset of a degree of randomization in the originally strong (111) texture of the as-grown layers. Optical band gap measurements showed sharpening of the band-edge upon annealing at 400 deg. C and a band gap value in the range of 1.46-1.49 eV. Resistivity measurements indicated that annealing at 400 deg. C in air forms a highly resistive compensated CdTe film. All results point to 400 deg. C to be a critical annealing temperature at which optical, structural and electrical properties of CdTe layers start to change

  16. Thermally evaporated Ag nanoparticle films for plasmonic enhancement in organic solar cells: effects of particle geometry

    NARCIS (Netherlands)

    Haidari, G.; Hajimahmoodzadeh, M.; Fallah, H.R.; Peukert, A.; Chanaewa, A.; von Hauff, E.L.

    2015-01-01

    We report on the simple fabrication of Ag NP films via thermal evaporation and subsequent annealing. The NPs are formed on indium tin oxide electrodes, coated with PEDOT:PSS and implemented into PCPDTBT:PC70BM solar cells. Scanning electron microscopy and atomic force microscopy are used to

  17. Effects of straw mulching on soil evaporation during the soil thawing ...

    Indian Academy of Sciences (India)

    26

    Keywords: straw mulching, soil water evaporation, soil thawing period, freezing depth, soil liquid water content. 1. Introduction. The Songnen Plain, located in northeastern China, has 594×104 ha of cultivated land area and a grain yield of 395×108 kg. It is one of the most important food production bases in China (Yan et al.

  18. Modeling black hole evaporation

    CERN Document Server

    Fabbri, Alessandro

    2005-01-01

    The scope of this book is two-fold: the first part gives a fully detailed and pedagogical presentation of the Hawking effect and its physical implications, and the second discusses the backreaction problem, especially in connection with exactly solvable semiclassical models that describe analytically the black hole evaporation process. The book aims to establish a link between the general relativistic viewpoint on black hole evaporation and the new CFT-type approaches to the subject. The detailed discussion on backreaction effects is also extremely valuable.

  19. [Effect of shifting sand burial on evaporation reduction and salt restraint under saline water irrigation in extremely arid region].

    Science.gov (United States)

    Zhang, Jian-Guo; Zhao, Ying; Xu, Xin-Wen; Lei, Jia-Qiang; Li, Sheng-Yu; Wang, Yong-Dong

    2014-05-01

    The Taklimakan Desert Highway Shelterbelt is drip-irrigated with high saline groundwater (2.58-29.70 g x L(-1)), and shifting sand burial and water-salt stress are most common and serious problems in this region. So it is of great importance to study the effect of shifting sand burial on soil moisture evaporation, salt accumulation and their distribution for water saving, salinity restraint, and suitable utilization of local land and water resources. In this study, Micro-Lysimeters (MLS) were used to investigate dynamics of soil moisture and salt under different thicknesses of sand burial (1, 2, 3, 4, and 5 cm), and field control experiments of drip-irrigation were also carried out to investigate soil moisture and salt distribution under different thicknesses of shifting sand burial (5, 10, 15, 20, 25, 30, 35, and 40 cm). The soil daily and cumulative evaporation decreased with the increase of sand burial thickness in MLS, cumulative evaporation decreased by 2.5%-13.7% compared with control. And evaporative inhibiting efficiency increased with sand burial thickness, evaporative inhibiting efficiency of 1-5 cm sand burial was 16.7%-79.0%. Final soil moisture content beneath the interface of sand burial increased with sand burial thickness, and it increased by 2.5%-13.7% than control. The topsoil EC of shifting sand in MLS decreased by 1.19-6.00 mS x cm(-1) with the increasing sand burial thickness, whereas soil salt content beneath the interface in MLS increased and amplitude of the topsoil salt content was higher than that of the subsoil. Under drip-irrigation with saline groundwater, average soil moisture beneath the interface of shifting sand burial increased by 0.4% -2.0% compare with control, and the highest value of EC was 7.77 mS x cm(-1) when the sand burial thickness was 10 cm. The trend of salt accumulation content at shifting sand surface increased firstly, and then decreased with the increasing sand burial thickness. Soil salt contents beneath the

  20. Design and performance of multiple effect basin type solar still; Basin-taju koyo fukugogata taiyonetsu joryuki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H; Nosoko, T; Nagata, T [Univ. of the Ryukyus, Okinawa (Japan)

    1997-11-25

    A seawater desalinating still was devised, which utilizes solar heat and combines a basin type still with a multiple effect type still. The devised still has a triangular cross section, has a seawater basin at its bottom, wherein the slope facing the sun has a double glass window, and the other slope is arranged with a multiple effect still (three-step effect system). The sun light that has permeated the double glass window heats and evaporates seawater on the basin. Majority of the generated steam is condensed at the lower face of a lowermost partition of the multiple effect section, and its latent heat evaporates the seawater contained in a wick on the rear side. The steam is condensed at the lower face of the second partition, this action is repeated sequentially to upper plates, and the heat is discharged finally into the surrounding air from the uppermost face of the multiple effect section. Seawater is supplied from the upper part onto the wick in each partition, which is evaporated, condensed and recovered at the lower part. The condensate is recovered at the lower part of each plate. The construction is simpler than the conventional downward indirect heating multiple effect type still, and the distilling efficiency is improved by 30%. Technological difficulty in the upward direct heating multiple effect type still can also be improved. 6 refs., 6 figs., 2 tabs.

  1. A stability investigation of two-dimensional surface waves on evaporating, isothermal or condensing liquid films - Part I, Thermal non-equilibrium effects on wave velocity

    International Nuclear Information System (INIS)

    Chunxi, L.; Xuemin, Y.

    2004-01-01

    The temporal stability equation of the two-dimensional traveling waves of evaporating or condensing liquid films falling down on an inclined wall is established based on the Prandtl boundary layer theory and complete boundary conditions. The model indicates that the wave velocity is related to the effects of evaporating, isothermal and condensing states, thermo-capillarity, Reynolds number, fluid property and inclined angle, and the effects of above factors are distinctly different under different Reynolds numbers. The theoretical studies show that evaporation process induces the wave velocity to increase slightly compared with the isothermal case, and condensation process induces the wave velocity to decrease slightly. Furthermore, the wave velocity decreases because of the effects of thermo-capillarity under evaporation and increases because of the effects of thermo-capillarity under condensation. The effects of thermal non-equilibrium conditions have relatively obvious effects under lower Reynolds numbers and little effects under higher Reynolds numbers

  2. Effect of annealing and In content on the properties of electron beam evaporated ZnO films

    Science.gov (United States)

    Mohamed, S. H.; Ali, H. M.; Mohamed, H. A.; Salem, A. M.

    2005-08-01

    The effect of both annealing and In content on the properties of ZnO films prepared by electron beam evaporation were investigated. The evaporation was carried out at room temperature from bulk samples prepared by sintering technique. X-ray diffraction showed that the structure of ZnO-In{2}O{3} films depends on both the In content and annealing temperature. Amorphous, highly transparent and relatively low resistive films which can be suitable for the usage as transparent electrode of organic light-emitting diode were obtained upon annealing at 300 circC. Partially crystalline, highly transparent and highly resistive films which can be used in piezoelectric applications were obtained upon annealing at 500 circC. For each composition the refractive index has no monotonic variation upon increasing annealing temperature.

  3. Laboratory study on the cooling effect of flash water evaporative cooling technology for ventilation and air-conditioning of buildings

    DEFF Research Database (Denmark)

    Fang, Lei; Yuan, Shu; Yang, Jianrong

    environments and the other simulated an air-conditioned indoor environment. The flash water evaporation cooling device was installed in the chamber that simulated indoor environment. The air from the chamber simulating outdoor environment was introduced into the cooling device and cooled by the flash water......, is effective for ventilation and air-conditioning in warm/hot and dry climate zones. The technology can provide fresh outdoor air with a temperature of 4 to 7 °C lower than room air temperature.......This paper presents a simple cooling technology using flash water evaporation. The technology combines a water atomizer with a plate heat exchanger used for heat recovery of a ventilation system. It is mainly used to cool the ventilation airflow from outdoors and is particularly suitable to be used...

  4. Natural convection with evaporation in a vertical cylindrical cavity under the effect of temperature-dependent surface tension

    Science.gov (United States)

    Kozhevnikov, Danil A.; Sheremet, Mikhail A.

    2018-01-01

    The effect of surface tension on laminar natural convection in a vertical cylindrical cavity filled with a weak evaporating liquid has been analyzed numerically. The cylindrical enclosure is insulated at the bottom, heated by a constant heat flux from the side, and cooled by a non-uniform evaporative heat flux from the top free surface having temperature-dependent surface tension. Governing equations with corresponding boundary conditions formulated in dimensionless stream function, vorticity, and temperature have been solved by finite difference method of the second-order accuracy. The influence of Rayleigh number, Marangoni number, and aspect ratio on the liquid flow and heat transfer has been studied. Obtained results have revealed that the heat transfer rate at free surface decreases with Marangoni number and increases with Rayleigh number, while the average temperature inside the cavity has an opposite behavior; namely, it growths with Marangoni number and reduces with Rayleigh number.

  5. Passive cooling effect of RC roof covered with the ceramics having high water retention and evaporation capacity

    International Nuclear Information System (INIS)

    Yamazaki, M; Kanaya, M; Shimazu, T; Ohashi, T; Kato, N; Horikoshi, T

    2011-01-01

    Hot days in metropolitan cities have increased remarkably by the heat island phenomenon these days. Thus the authors tried to develop the porous ceramics with high water retention and evaporation capacity as a maintenance-free material to improve thermal environment. The developed ceramic pellets have high water retention of more than 60% of water absorption and high water evaporation which is similar to water surface. In this study, three types of 5 meter squared large flat-roofed structural specimen simulated reinforced concrete (RC) slab were constructed on the outside. The variation of water content and temperature of the specimens and atmosphere temperature around the specimens were measured from summer in 2009. In the case of the ceramic pellets, the temperature under RC slab was around 15 deg. lower than that of the control. The results were probably contributed by passive cooling effect of evaporated rain water, and the effect was similar to in the case of the grasses. From the viewpoint of thermal environment improvement, substitution of a rooftop gardening by the porous ceramics could be a promising method.

  6. Effects of Carbonyl Bond and Metal Cluster Dissociation and Evaporation Rates on Predictions of Nanotube Production in HiPco

    Science.gov (United States)

    Scott, Carl D.; Smalley, Richard E.

    2002-01-01

    The high-pressure carbon monoxide (HiPco) process for producing single-wall carbon nanotubes (SWNT) uses iron pentacarbonyl as the source of iron for catalyzing the Boudouard reaction. Attempts using nickel tetracarbonyl led to no production of SWNTs. This paper discusses simulations at a constant condition of 1300 K and 30 atm in which the chemical rate equations are solved for different reaction schemes. A lumped cluster model is developed to limit the number of species in the models, yet it includes fairly large clusters. Reaction rate coefficients in these schemes are based on bond energies of iron and nickel species and on estimates of chemical rates for formation of SWNTs. SWNT growth is measured by the co-formation of CO2. It is shown that the production of CO2 is significantly greater for FeCO due to its lower bond energy as compared with that ofNiCO. It is also shown that the dissociation and evaporation rates of atoms from small metal clusters have a significant effect on CO2 production. A high rate of evaporation leads to a smaller number of metal clusters available to catalyze the Boudouard reaction. This suggests that if CO reacts with metal clusters and removes atoms from them by forming MeCO, this has the effect of enhancing the evaporation rate and reducing SWNT production. The study also investigates some other reactions in the model that have a less dramatic influence.

  7. Passive cooling effect of RC roof covered with the ceramics having high water retention and evaporation capacity

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, M; Kanaya, M; Shimazu, T; Ohashi, T [INAX Corporation, 97-1, Yariba, Kume, Tokoname, Aichi, 479-0002 (Japan); Kato, N; Horikoshi, T, E-mail: m.yamazaki@i2.inax.co.jp [Department of Architecture, Nagoya Institute of technology, Gokiso-cho, Showa-ku, Nagoya, Aichi, 466-8555 (Japan)

    2011-10-29

    Hot days in metropolitan cities have increased remarkably by the heat island phenomenon these days. Thus the authors tried to develop the porous ceramics with high water retention and evaporation capacity as a maintenance-free material to improve thermal environment. The developed ceramic pellets have high water retention of more than 60% of water absorption and high water evaporation which is similar to water surface. In this study, three types of 5 meter squared large flat-roofed structural specimen simulated reinforced concrete (RC) slab were constructed on the outside. The variation of water content and temperature of the specimens and atmosphere temperature around the specimens were measured from summer in 2009. In the case of the ceramic pellets, the temperature under RC slab was around 15 deg. lower than that of the control. The results were probably contributed by passive cooling effect of evaporated rain water, and the effect was similar to in the case of the grasses. From the viewpoint of thermal environment improvement, substitution of a rooftop gardening by the porous ceramics could be a promising method.

  8. Multiple interdependencies and workgroup effectiveness

    NARCIS (Netherlands)

    Rispens, Sonja

    2006-01-01

    In this thesis I focus on the question how the alignment of interdependency leads to an effective level of performance in work groups or teams. For the continuance of every organization it is important to organize individuals so that their actions are aligned (Heath & Staudenmayer, 2000). In this

  9. The evaporation of the charged and uncharged water drops

    Indian Academy of Sciences (India)

    Drop evaporation; ventilation coefficient; evaporation-effect of electrical forces. ... to study the effect of ventilation on the rate of evaporation of the millimeter sized ... a ventilated drop to reach its equilibrium temperature increases with the drop ...

  10. An experimental observation of the effect of flow direction for evaporation heat transfer in plate heat exchanger

    International Nuclear Information System (INIS)

    Lin, Yueh-Hung; Li, Guang-Cheng; Yang, Chien-Yuh

    2015-01-01

    This study provides an Infrared Thermal Image observation on the evaporation heat transfer of refrigerant R-410A in plate heat exchanger with various flow arrangement and exit superheat conditions. An experimental method was derived for estimating the superheat region area of two-phase refrigerant evaporation in plate heat exchanger. The experimental results show that the superheat region area for parallel flow is much larger than that for counter flow as that estimated by Yang et al. [9]. There is an early superheated region at the central part of the plate heat exchanger for parallel flow arrangement. This effect is not significant for counter flow arrangement. The Yang et al. [9] method under estimated the superheat area approximately 40%–53% at various flow rates and degree of exit superheat. Even though the flow inside a plate heat exchanger is extremely turbulent because of the chevron flow passages, the assumption of uniform temperature distribution in the cross section normal to the bulk flow direction will cause significant uncertainties for estimating the superheat area for refrigerant evaporating in a plate heat exchanger

  11. Effects of spray axis incident angle on heat transfer performance of rhombus-pitch shell-and-tube interior spray evaporator

    International Nuclear Information System (INIS)

    Lin, Ru-Li; Chang, Tong-Bou; Liang, Chih-Chang

    2012-01-01

    An interior spray method is proposed for enhancing the heat transfer performance of a compact rhombus-pitch shell-and-tube spray evaporator. The experimental results show that the shell-side heat transfer coefficient obtained using the proposed spray method is significantly higher than that achieved in a conventional flooded-type evaporator. Four different spray axis incident angles (0 .deg., 45 .deg., 60 .deg. and 75 .deg.) are tested in order to investigate the effect of the spray inclination angle on the heat transfer performance of the spray evaporator system. It is shown that the optimal heat transfer performance is obtained using a spray axis incident angle of 60 .deg.

  12. New models for droplet heating and evaporation

    KAUST Repository

    Sazhin, Sergei S.; Elwardani, Ahmed Elsaid; Gusev, Ivan G.; Xie, Jianfei; Shishkova, Irina N.; Cao, Bingyang; Snegirev, Alexander Yu.; Heikal, Morgan Raymond

    2013-01-01

    and evaporation, taking into account the effects of the moving boundary due to evaporation, hydrodynamic models of multi-component droplet heating and evaporation, taking and not taking into account the effects of the moving boundary, new kinetic models of mono

  13. Effect of substrate temperatures on the optical properties of evaporated Sc2O3 thin films

    International Nuclear Information System (INIS)

    Liu Guanghui; Jin Yunxia; He Hongbo; Fan Zhengxiu

    2010-01-01

    Scandium oxide (Sc 2 O 3 ) films were deposited by electron beam evaporation with substrate temperatures varying from 50 to 350 o C. X-ray diffraction, scanning electron microscopy, spectrometer, and optical profilograph were employed to investigate the structural and optical properties of the films. The refractive index and extinction coefficient were calculated from the transmittance and reflectance spectra, and then the energy band gaps were deduced and discussed. Laser induced damage threshold of the films were also characterized. Optical and structural properties of Sc 2 O 3 films were found to be sensitive to substrate temperature.

  14. Estimating scaled treatment effects with multiple outcomes.

    Science.gov (United States)

    Kennedy, Edward H; Kangovi, Shreya; Mitra, Nandita

    2017-01-01

    In classical study designs, the aim is often to learn about the effects of a treatment or intervention on a single outcome; in many modern studies, however, data on multiple outcomes are collected and it is of interest to explore effects on multiple outcomes simultaneously. Such designs can be particularly useful in patient-centered research, where different outcomes might be more or less important to different patients. In this paper, we propose scaled effect measures (via potential outcomes) that translate effects on multiple outcomes to a common scale, using mean-variance and median-interquartile range based standardizations. We present efficient, nonparametric, doubly robust methods for estimating these scaled effects (and weighted average summary measures), and for testing the null hypothesis that treatment affects all outcomes equally. We also discuss methods for exploring how treatment effects depend on covariates (i.e., effect modification). In addition to describing efficiency theory for our estimands and the asymptotic behavior of our estimators, we illustrate the methods in a simulation study and a data analysis. Importantly, and in contrast to much of the literature concerning effects on multiple outcomes, our methods are nonparametric and can be used not only in randomized trials to yield increased efficiency, but also in observational studies with high-dimensional covariates to reduce confounding bias.

  15. Effectiveness of indirect evaporative cooling and thermal mass in a hot arid climate

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Eduardo [Programa de Pos-Graduacao em Tecnologia/Programa de Pos-Graduacao em Engenharia Civil, Departamento de Construcao Civil, Universidade Tecnologica Federal do Parana - UTFPR, Av. Sete de Setembro, 3165. Curitiba PR, CEP. 80230-901 (Brazil); Gonzalez Cruz, Eduardo [Instituto de Investigaciones de la Facultad de Arquitectura y Diseno (IFAD), Universidad del Zulia, Nucleo Tecnico de LUZ, Av. Goajira (16) con Calle 67, Maracaibo, CP 4011-A-526 (Venezuela); Givoni, Baruch [Department of Architecture, School of Arts and Architecture, UCLA, Los Angeles CA, USA, and Ben Gurion University (Israel)

    2010-06-15

    In this paper, we compare results of a long-term temperature monitoring in a building with high thermal mass to indoor temperature predictions of a second building that uses an indirect evaporative cooling system as a means of passive cooling (Vivienda Bioclimatica Prototipo -VBP-1), for the climatic conditions of Sde Boqer, Negev region of Israel (local latitude 30 52'N, longitude 34 46'E, approximately 480 m above sea level). The high-mass building was monitored from January through September 2006 and belongs to a student dormitory complex located at the Sde Boqer Campus of Ben-Gurion University. VBP-1 was designed and built in Maracaibo, Venezuela (latitude 10 34'N, longitude 71 44'W, elevation 66 m above sea level) and had its indoor air temperatures, below and above a shaded roof pond, as well as the pond temperature monitored from February to September 2006. Formulas were developed for the VBP-1, based on part of the whole monitoring period, which represent the measured daily indoor maximum, average and minimum temperatures. The formulas were then validated against measurements taken independently in different time periods. The developed formulas were here used for estimating the building's thermal and energy performance at the climate of Sde Boqer, allowing a comparison of two different strategies: indirect evaporative cooling and the use of thermal mass. (author)

  16. Effects of Sulfurization Temperature on Properties of CZTS Films by Vacuum Evaporation and Sulfurization Method

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2013-01-01

    Full Text Available Copper zinc tin sulfur (CZTS thin films have been extensively studied in recent years for their advantages of low cost, high absorption coefficient (≥104 cm−1, appropriate band gap (~1.5 eV, and nontoxicity. CZTS thin films are promising materials of solar cells like copper indium gallium selenide (CIGS. In this work, CZTS thin films were prepared on glass substrates by vacuum evaporation and sulfurization method. Sn/Cu/ZnS (CZT precursors were deposited by thermal evaporation and then sulfurized in N2 + H2S atmosphere at temperatures of 360–560°C to produce polycrystalline CZTS thin films. It is found that there are some impurity phases in the thin films with the sulfurization temperature less than 500°C, and the crystallite size of CZTS is quite small. With the further increase of the sulfurization temperature, the obtained thin films exhibit preferred (112 orientation with larger crystallite size and higher density. When the sulfurization temperature is 500°C, the band gap energy, resistivity, carrier concentration, and mobility of the CZTS thin films are 1.49 eV, 9.37 Ω · cm, 1.714×1017 cm−3, and 3.89 cm2/(V · s, respectively. Therefore, the prepared CZTS thin films are suitable for absorbers of solar cells.

  17. Effect of magnetic field on the growth of Be films prepared by thermal evaporation

    International Nuclear Information System (INIS)

    Li, Kai; Luo, Bing-chi; Tan, Xiu-lan; Zhang, Ji-qiang; Wu, Wei-dong; Liu, Ying

    2014-01-01

    Highlights: • The Be films were prepared on Si (1 0 0) substrates with and without a magnetic field by thermal evaporation, respectively. • The grain diameter in the Be film transited from 300 nm to 18 nm by application of the magnetic field. • The surface roughness of the Be film decreased from 61 nm to 3 nm by application of the magnetic field. • The Be film grown with the magnetic field was easily oxidized due to its refined grains and the oxidation was gradually decreased with increasing the etching depth in the film. - Abstract: Grain refinement of beryllium deposits is studied as a significant subject for beryllium capsule in the Inertial Confinement Fusion project. The Be films were prepared on the Si (1 0 0) substrates by thermal evaporation with and without a magnetic field, respectively. The two separate groups of prepared Be films were characterized. The results showed the grain diameter in the Be film transited from 300 nm to 18 nm and the surface roughness of the Be film decreased from 61 nm to 3 nm by application of the magnetic field during the deposition process of Be coating. However, the Be film grown with the magnetic field was easily oxidized in comparison with that grown without magnetic field due to the refined grains, and the oxidation was gradually decreased with the increase of etching depth in the Be film. The reason for grain refinement of Be film was also qualitatively described

  18. The Evaporation and Survival of Cluster Galaxy Coronae. I. The Effectiveness of Isotropic Thermal Conduction Including Saturation

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaraghavan, Rukmani; Sarazin, Craig, E-mail: rukmani@virginia.edu [Department of Astronomy, University of Virginia, 530 McCormick Rd., Charlottesville, VA 22904 (United States)

    2017-05-20

    We simulate the evolution of cluster galaxy hot interstellar medium (ISM) gas that is a result of the effects of ram pressure and thermal conduction in the intracluster medium (ICM). At the density and temperature of the ICM, the mean free paths of ICM electrons are comparable to the sizes of galaxies, therefore electrons can efficiently transport heat that is due to thermal conduction from the hot ICM to the cooler ISM. Galaxies consisting of dark matter halos and hot gas coronae are embedded in an ICM-like “wind tunnel” in our simulations. In this paper, we assume that thermal conduction is isotropic and include the effects of saturation. We find that as heat is transferred from the ICM to the ISM, the cooler denser ISM expands and evaporates. This process is significantly faster than gas loss due to ram pressure stripping; for our standard model galaxy, the evaporation time is 160 Myr, while the ram pressure stripping timescale is 2.5 Gyr. Thermal conduction also suppresses the formation of shear instabilities, and there are no stripped ISM tails since the ISM evaporates before tails can form. Observations of long-lived X-ray emitting coronae and ram pressure stripped X-ray tails in galaxies in group and cluster environments therefore require that thermal conduction is suppressed or offset by some additional physical process. The most likely process is anisotropic thermal conduction that is due to magnetic fields in the ISM and ICM, which we simulate and study in the next paper in this series.

  19. The Evaporation and Survival of Cluster Galaxy Coronae. I. The Effectiveness of Isotropic Thermal Conduction Including Saturation

    International Nuclear Information System (INIS)

    Vijayaraghavan, Rukmani; Sarazin, Craig

    2017-01-01

    We simulate the evolution of cluster galaxy hot interstellar medium (ISM) gas that is a result of the effects of ram pressure and thermal conduction in the intracluster medium (ICM). At the density and temperature of the ICM, the mean free paths of ICM electrons are comparable to the sizes of galaxies, therefore electrons can efficiently transport heat that is due to thermal conduction from the hot ICM to the cooler ISM. Galaxies consisting of dark matter halos and hot gas coronae are embedded in an ICM-like “wind tunnel” in our simulations. In this paper, we assume that thermal conduction is isotropic and include the effects of saturation. We find that as heat is transferred from the ICM to the ISM, the cooler denser ISM expands and evaporates. This process is significantly faster than gas loss due to ram pressure stripping; for our standard model galaxy, the evaporation time is 160 Myr, while the ram pressure stripping timescale is 2.5 Gyr. Thermal conduction also suppresses the formation of shear instabilities, and there are no stripped ISM tails since the ISM evaporates before tails can form. Observations of long-lived X-ray emitting coronae and ram pressure stripped X-ray tails in galaxies in group and cluster environments therefore require that thermal conduction is suppressed or offset by some additional physical process. The most likely process is anisotropic thermal conduction that is due to magnetic fields in the ISM and ICM, which we simulate and study in the next paper in this series.

  20. Structure, surface morphology and electrical properties of evaporated Ni thin films: Effect of substrates, thickness and Cu underlayer

    International Nuclear Information System (INIS)

    Hemmous, M.; Layadi, A.; Guittoum, A.; Souami, N.; Mebarki, M.; Menni, N.

    2014-01-01

    Series of Ni thin films have been deposited by thermal evaporation onto glass, Si(111), Cu, mica and Al 2 O 3 substrates with and without a Cu underlayer. The Ni thicknesses, t, are in the 4 to 163 nm range. The Cu underlayer has also been evaporated with a Cu thickness equal to 27, 52 and 90 nm. The effects of substrate, the Ni thickness and the Cu underlayer on the structural and electrical properties of Ni are investigated. Rutherford Backscattering Spectroscopy was used to probe the Ni/Substrate and Ni–Cu underlayer interfaces and to measure both Ni and Cu thicknesses. The texture, the strain and the grain size values were derived from X-ray diffraction experiments. The surface morphology is studied by means of a Scanning Electron Microscope. The electrical resistivity is measured by the four point probe. The Ni films grow with the <111> texture on all substrates. The Ni grain sizes D increase with increasing thickness for the glass, Si and mica substrates and decrease for the Cu one. The strain ε is positive for low thickness, decreases in magnitude and becomes negative as t increases. With the Cu underlayer, the growth mode goes through two phases: first, the stress (grain size) increases (decreases) up to a critical thickness t Cr , then stress is relieved and grain size increases. All these results will be discussed and correlated. - Highlights: • The structural and electrical properties of evaporated Ni thin films are studied. • The effect of thickness, substrates and Cu underlayer is investigated. • Texture, grain size, strain and surface morphology are discussed. • Growth modes are described as a function of Ni thickness

  1. Formation of functionalized nanoclusters by solvent evaporation and their effect on the physicochemical properties of dental composite resins.

    Science.gov (United States)

    Rodríguez, Henry A; Giraldo, Luis F; Casanova, Herley

    2015-07-01

    The aim of this work was to study the effect of silica nanoclusters (SiNC), obtained by a solvent evaporation method and functionalized by 3-methacryloxypropyltrimethoxysilane (MPS) and MPS+octyltrimethoxysilane (OTMS) (50/50wt/wt), on the rheological, mechanical and sorption properties of urethane dimethylacrylate (UDMA)/triethylenglycol dimethacrylate (TEGDMA) (80/20wt/wt) resins blend. Silica nanoparticles (SiNP) were silanized with MPS or MPS+OTMS (50/50wt/wt) and incorporated in an UDMA-isopropanol mix to produce functionalized silica nanoclusters after evaporating the isopropanol. The effect of functionalized SiNC on resins rheological properties was determined by large and small deformation tests. Mechanical, thermal, sorption and solubility properties were evaluated for composite materials. The UDMA/TEGDMA (80/20wt/wt) resins blend with added SiNC (ca. 350nm) and functionalized with MPS showed a Newtonian flow behavior associated to their spheroidal shape, whereas the resins blend with nanoclusters silanized with MPS+OTMS (50/50wt/wt) (ca. 400nm) showed a shear-thinning behavior due to nanoclusters irregular shape. Composite materials prepared with bare silica nanoclusters showed lower compressive strength than functionalized silica nanoclusters. MPS functionalized nanoclusters showed better mechanical properties but higher water sorption than functionalized nanoclusters with both silane coupling agents, MPS and OTMS. The solvent evaporation method applied to functionalized nanoparticles showed to be an alternative way to the sinterization method for producing nanoclusters, which improved some dental composite mechanical properties and reduced water sorption. The shape of functionalized silica nanoclusters showed to have influence on the rheological properties of SiNC resin suspensions and the mechanical and sorption properties of light cured composites. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  2. Effects of evaporation pressure and antifoam concentration and the use of a flocculant and adjuvant on the quality of sugar honey and panela

    Directory of Open Access Journals (Sweden)

    Luz Esperanza Prada Forero

    2014-07-01

    Full Text Available The implementation of multi-effect evaporators on panela (unrefined whole cane sugar production process requires, besides the technological adjustment, to maintain product characteristics; this condition revealed the lack of knowledge of the effect of evaporation pressure on the quality of panela. In order to fill part of this gap, this study sought to determine the effect of both the concentration of antifoam and the use of a flocculant (Heliocarpus popayanensis Kunth and an adjuvant (lime on the quality of sugar honey and panela, when evaporation is performed at different atmospheric pressures. In order to achieve this, the present study worked on two completely randomized experimental designs with four replications, a density of evaporation heat flow of 27.78 kW/m2 and juice from the CC85-46 variety. In the first design, two variables were studied: evaporation pressure and use of flocculant and adjuvant with a 4x2x2 factorial arrangement without antifoam. In the second design, variables evaporation pressure and quantity of antifoam with a 4x3 factorial arrangement without flocculant nor adjuvant were studied. The results show that the quality of the product deteriorates in pressurized systems (glucoside coefficient increases up to 200%, is not affected by the use of 50 μL of antifoam per liter of clarified juice and improved by the use of flocculant (turbidity is reduced by 55%. Solidification and hardness improve with the addition of the adjuvant, but this increased 48% color and 24% turbidity.

  3. Effect of pervaporation plate thickness on the rate of methanol evaporation in a passive vapor-feed direct methanol fuel cell

    Science.gov (United States)

    Fauzi, N. F. I.; Hasran, U. A.; Kamarudin, S. K.

    2015-09-01

    In a passive vapor-feed direct methanol fuel cell (DMFC), methanol vapor is typically obtained using a pervaporation plate in a process by which liquid methanol contained in the fuel reservoir undergoes a phase change to vapor in the anodic vapor chamber. This work investigates the effect of pervaporation plate thickness on the rate of methanol evaporation using a three-dimensional simulation model developed by varying the plate thickness. A. The rate of methanol evaporation was measured using Darcy's law. The rate of methanol evaporation was found to be inversely proportional to the plate thickness, where the decrease in thickness inevitably lowers the resistance along the plate and consequently increases the methanol transport through the plate. This shows that the plate thickness has a significant influence on the rate of methanol evaporation and thereby plays an important role in improving the performance of the passive vapor-feed direct methanol fuel cell.

  4. Effect of pervaporation plate thickness on the rate of methanol evaporation in a passive vapor-feed direct methanol fuel cell

    International Nuclear Information System (INIS)

    Fauzi, N F I; Hasran, U A; Kamarudin, S K

    2015-01-01

    In a passive vapor-feed direct methanol fuel cell (DMFC), methanol vapor is typically obtained using a pervaporation plate in a process by which liquid methanol contained in the fuel reservoir undergoes a phase change to vapor in the anodic vapor chamber. This work investigates the effect of pervaporation plate thickness on the rate of methanol evaporation using a three-dimensional simulation model developed by varying the plate thickness. A. The rate of methanol evaporation was measured using Darcy's law. The rate of methanol evaporation was found to be inversely proportional to the plate thickness, where the decrease in thickness inevitably lowers the resistance along the plate and consequently increases the methanol transport through the plate. This shows that the plate thickness has a significant influence on the rate of methanol evaporation and thereby plays an important role in improving the performance of the passive vapor-feed direct methanol fuel cell. (paper)

  5. Surface wettability and triple line behavior controlled by nano-coatings: effects on the sessile drop evaporation

    Science.gov (United States)

    Sobac, Benjamin; Brutin, David; Gavillet, Jerôme

    2010-11-01

    Sessile drop evaporation is a phenomenon commonly came across in nature or in industry with cooling, paintings or DNA mapping. However, the evaporation of a drop posed on a substrate is not completely understood due to the complexity of the problem. Here we investigate, with several nano-coating of the substrate (SiOx, SiOc and CF), the wettability and the triple line dynamic of a sessile drop under natural phase change. The experiment consists in analyzing simultaneously the kinetics of evaporation, internal thermal motion and heat and mass transfer. Measurements of temperature, heat-flux and visualizations with visible and infrared cameras are performed. The dynamic of the evaporative heat flux appears clearly different for a drop evaporating in pinned mode than in receding mode. Moreover, the kinetics of evaporation, the internal flow structure and the evaporative heat flux are drastically influenced by the wettability the substrate.

  6. Evaporation from a sphagnum moss surface

    Science.gov (United States)

    D.S. Nichols; J.M. Brown

    1980-01-01

    Peat cores, 45 cm in diameter, were collected from a sphagnum bog in northern Minnesota, and used to measure the effects of different temperatures and water levels on evaporation from a sphagnum moss surface in a growth chamber. Under all conditions, evaporation from the moss surface was greater than that from a free-water surface. Evaporation from the moss increased...

  7. Olive mill wastewater disposal in evaporation ponds in Sfax (Tunisia): moisture content effect on microbiological and physical chemical parameters.

    Science.gov (United States)

    Jarboui, Raja; Hadrich, Bilel; Gharsallah, Néji; Ammar, Emna

    2009-11-01

    The study of the isotherms desorption of olive mill wastewater (OMW) was investigated to describe its water activity under different saturated environments. The microbial biodegradation of OMW during its storage in 5 evaporation ponds located in Agareb (Sfax-Tunisia) was carried out during the oil-harvesting year held 105 days in 2004. Gravimetric static method using saturated salt solutions was used and OMW as placed at 30 degrees C and under different water activities ranging from 0.11 to 0.90. Eight models were taken from the literature to describe experimental desorption isotherms. During storage, the evolution of physico-chemical parameters including pH, temperature, evaporation, humidity, total phosphorus, chemical oxygen demand (COD), biological oxygen demand (BOD) and phenols and three microbiological flora (aerobic mesophilic bacteria, yeasts and moulds) were considered. At 30 degrees C, when relative humidity increased in the experimented ponds of 69, 84 and 90%, the evaporation speed decreased from 1.24 x 10(-5) to 5 x 10(-6) cm(3) s(-1), from 6 x 10(-5) to 7 x 10(-6) cm(3) s(-1) and from 5 x 10(-6) to 1.1 x 10(-7) cm(3) s(-1) respectively. The desorption isotherm exhibited a sigmoidal curve corresponding to type II, typical of many organic material. The GAB and Peleg models gave the best fit for describing the relationship between the equilibrium moisture content and water activity in OMW (R (2) = 0.998). During the storage period, the analysis showed an increase of all the physico-chemical parameters studied, except phenols and total phosphorus concentrations. The microbiological study showed the predominance of yeasts and moulds and the decrease of bacteria population after 75 days reflecting both effect of recalcitrant compounds and the water activity on microbial growth.

  8. Experimental evaporation of hyperacid brines: Effects on chemical composition and chlorine isotope fractionation

    Science.gov (United States)

    Rodríguez, Alejandro; van Bergen, Manfred J.; Eggenkamp, H. G. M.

    2018-02-01

    Hyperacid brines from active volcanic lakes are some of the chemically most complex aqueous solutions on Earth. Their compositions provide valuable insights into processes of elemental transfer from a magma body to the surface and interactions with solid rocks and the atmosphere. This paper describes changes in chemical and δ37Cl signatures observed in a 1750 h isothermal evaporation experiment on hyperacid (pH 0.1) sulphate-chloride brine water from the active lake of Kawah Ijen volcano (Indonesia). Although gypsum was the only evaporite mineral identified in the evolving brine, decreasing Si concentrations may ultimately result in amorphous silica precipitation. Geochemical simulations predict the additional formation of elemental sulphur at lower water activities (aH2O ≤ 0.65) that were not reached in the experiment. Absence of other sulphates and halides despite the high load of dissolved elements (initial TDS ca. 100 g/kg) can be attributed to increased solubility of metals, promoted by extensive formation of complexes between the variety of cations and the major anions (HSO4-, Cl-, F-) present. Chlorine deviations from a conservative behaviour point to losses of gaseous hydrogen chloride (HCl(g)) and consequently an increase in Br/Cl ratios. Chlorine isotope fractionation that accompanied the escape of HCl(g) showed a marked change in sign and magnitude in the course of progressive evaporation of the brine. The calculated factor of fractionation between HCl(g) and dissolved Cl for the initial interval (before 500 h) is positive (1000lnαHCl(g)-Cldiss. = + 1.55 ± 0.49‰to + 3.37 ± 1.11‰), indicating that, at first, the escaping HCl(g) was isotopically heavier than the dissolved Cl remaining in the brine. Conversely, fractionation shifted to the opposite direction in the subsequent interval (1000lnαHCl(g)-Cldiss. = 5.67 ± 0.17‰to - 5.64 ± 0.08‰), in agreement with values reported in literature. It is proposed that Cl isotopic fractionation in

  9. Effects of convective ice evaporation on interannual variability of tropical tropopause layer water vapor

    Science.gov (United States)

    Ye, Hao; Dessler, Andrew E.; Yu, Wandi

    2018-04-01

    Water vapor interannual variability in the tropical tropopause layer (TTL) is investigated using satellite observations and model simulations. We break down the influences of the Brewer-Dobson circulation (BDC), the quasi-biennial oscillation (QBO), and the tropospheric temperature (ΔT) on TTL water vapor as a function of latitude and longitude using a two-dimensional multivariate linear regression. This allows us to examine the spatial distribution of the impact of each process on TTL water vapor. In agreement with expectations, we find that the impacts from the BDC and QBO act on TTL water vapor by changing TTL temperature. For ΔT, we find that TTL temperatures alone cannot explain the influence. We hypothesize a moistening role for the evaporation of convective ice from increased deep convection as the troposphere warms. Tests using a chemistry-climate model, the Goddard Earth Observing System Chemistry Climate Model (GEOSCCM), support this hypothesis.

  10. Effect of Temperature on Nucleation of Nanocrystalline Indium Tin Oxide Synthesized by Electron-Beam Evaporation

    Science.gov (United States)

    Shen, Yan; Zhao, Yujun; Shen, Jianxing; Xu, Xiangang

    2017-07-01

    Indium tin oxide (ITO) has been widely applied as a transparent conductive layer and optical window in light-emitting diodes, solar cells, and touch screens. In this paper, crystalline nano-sized ITO dendrites are obtained using an electron-beam evaporation technique. The surface morphology of the obtained ITO was studied for substrate temperatures of 25°C, 130°C, 180°C, and 300°C. Nano-sized crystalline dendrites were synthesized only at a substrate temperature of 300°C. The dendrites had a cubic structure, confirmed by the results of x-ray diffraction and transmission electron microscopy. The growth mechanism of the nano-crystalline dendrites could be explained by a vapor-liquid-solid (VLS) growth model. The catalysts of the VLS process were indium and tin droplets, confirmed by varying the substrate temperature, which further influenced the nucleation of the ITO dendrites.

  11. Effect of water losses by evaporation and chemical reaction in an industrial slaker reactor

    Directory of Open Access Journals (Sweden)

    Ricardo Andreola

    2007-03-01

    Full Text Available A dynamic model of the slaker reactor was developed and validated for Klabin Paraná Papéis causticizing system, responsable for white liquor generation used by the plant. The model considered water losses by evaporation and chemical reaction. The model showed a good agreement with the industrial plant measures of active alkali, total titratable alkali and temperature, without the need of adjustment of any parameter. The simulated results showed that the water consumption by the slaking reaction and evaporation exerted significant influence on the volumetric flow rate of limed liquor, which imposed a decrease of 4.6% in the amount of water in reactor outlet.Foi desenvolvido e testado um modelo dinâmico do reator de apagamento do sistema de caustificação da Klabin Paraná Papéis, responsável pela geração do licor branco utilizado na planta. O modelo contempla perdas de água por evaporação e por reação química e apresentou boa concordância com dados industriais de álcali ativo, álcali total titulável e temperatura, sem a necessidade de ajuste de nenhum parâmetro. Os resultados obtidos a partir de simulações revelam que o consumo de água pela reação de apagamento, bem como pela evaporação, exercem uma influência significativa sobre a vazão volumétrica na saída do reator, impondo uma diminuição de 4,6% sobre o teor de água na corrente de saída do reator em relação à alimentação.

  12. The evaporative drying of sludge by immersion in hot oil: Effects of oil type and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Tae-In, E-mail: tiohm1@hanbat.ac.kr [Department of Environmental Engineering, Hanbat National University, San 16-1 Duckmyung-dong, Yusung-gu, Daejeon 305-719 (Korea, Republic of); Chae, Jong-Seong; Lim, Kwang-Soo [Department of Environmental Engineering, Hanbat National University, San 16-1 Duckmyung-dong, Yusung-gu, Daejeon 305-719 (Korea, Republic of); Moon, Seung-Hyun [Waste Energy Research Center, Korea Institute of Energy Research, Jang-dong Yusung-gu, Daejeon 305-343 (Korea, Republic of)

    2010-06-15

    We investigated the evaporative drying by immersion in hot oil (EDIHO) method for drying sludge. This involved heating oil to a temperature higher than that needed for moisture to be evaporated from the sludge by turbulent heat and mass transfer. We fry-dried sewage and leather plant sludge for 10 min in each of four different oils (waste engine, waste cooking, refined waste, and B-C heavy) and three different temperatures (140 deg. C, 150 deg. C, and 160 deg. C). Drying efficiency was found to be greater for higher temperatures. However, giving consideration to energy efficiency we suggest that the optimal temperature for fry-drying sludge is 150 deg. C. At 150 deg. C, the water content of sewage sludge reduced from 78.9% to between 1.5% (with waste cooking oil) and 3.8% (with waste engine oil). The reduction in water content for leather plant sludge fry-dried at 150 deg. C was from 81.6% to between 1% (with waste cooking oil) and 6.5% (with refined waste oil). The duration of the constant rate-drying period was also influenced by the type of oil used: refined waste oil > waste engine oil > B-C heavy oil > waste cooking oil. The duration at 150 deg. C with waste cooking oil was 3 min for sewage sludge and 2 min for leather plant sludge. It is likely that the drying characteristics of oil are influenced by its thermal properties, including its specific heat, and molecular weight.

  13. The evaporative drying of sludge by immersion in hot oil: Effects of oil type and temperature

    International Nuclear Information System (INIS)

    Ohm, Tae-In; Chae, Jong-Seong; Lim, Kwang-Soo; Moon, Seung-Hyun

    2010-01-01

    We investigated the evaporative drying by immersion in hot oil (EDIHO) method for drying sludge. This involved heating oil to a temperature higher than that needed for moisture to be evaporated from the sludge by turbulent heat and mass transfer. We fry-dried sewage and leather plant sludge for 10 min in each of four different oils (waste engine, waste cooking, refined waste, and B-C heavy) and three different temperatures (140 deg. C, 150 deg. C, and 160 deg. C). Drying efficiency was found to be greater for higher temperatures. However, giving consideration to energy efficiency we suggest that the optimal temperature for fry-drying sludge is 150 deg. C. At 150 deg. C, the water content of sewage sludge reduced from 78.9% to between 1.5% (with waste cooking oil) and 3.8% (with waste engine oil). The reduction in water content for leather plant sludge fry-dried at 150 deg. C was from 81.6% to between 1% (with waste cooking oil) and 6.5% (with refined waste oil). The duration of the constant rate-drying period was also influenced by the type of oil used: refined waste oil > waste engine oil > B-C heavy oil > waste cooking oil. The duration at 150 deg. C with waste cooking oil was 3 min for sewage sludge and 2 min for leather plant sludge. It is likely that the drying characteristics of oil are influenced by its thermal properties, including its specific heat, and molecular weight.

  14. Interfacial Instabilities in Evaporating Drops

    Science.gov (United States)

    Moffat, Ross; Sefiane, Khellil; Matar, Omar

    2007-11-01

    We study the effect of substrate thermal properties on the evaporation of sessile drops of various liquids. An infra-red imaging technique was used to record the interfacial temperature. This technique illustrates the non-uniformity in interfacial temperature distribution that characterises the evaporation process. Our results also demonstrate that the evaporation of methanol droplets is accompanied by the formation of wave-trains in the interfacial temperature field; similar patterns, however, were not observed in the case of water droplets. More complex patterns are observed for FC-72 refrigerant drops. The effect of substrate thermal conductivity on the structure of the complex pattern formation is also elucidated.

  15. Stress Effects on Multiple Memory System Interactions

    Science.gov (United States)

    Ness, Deborah; Calabrese, Pasquale

    2016-01-01

    Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory systems, we review recent animal and human studies exploring the effects of stress on multiple memory systems. Apart from discussing the interaction between distinct memory systems in stressful situations, we will also outline the fundamental role of the amygdala in mediating such stress effects. Additionally, based on the methods applied in the herein discussed studies, we will discuss how memory translates into behaviour. PMID:27034845

  16. Stress Effects on Multiple Memory System Interactions

    Directory of Open Access Journals (Sweden)

    Deborah Ness

    2016-01-01

    Full Text Available Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory systems, we review recent animal and human studies exploring the effects of stress on multiple memory systems. Apart from discussing the interaction between distinct memory systems in stressful situations, we will also outline the fundamental role of the amygdala in mediating such stress effects. Additionally, based on the methods applied in the herein discussed studies, we will discuss how memory translates into behaviour.

  17. Stress Effects on Multiple Memory System Interactions.

    Science.gov (United States)

    Ness, Deborah; Calabrese, Pasquale

    2016-01-01

    Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory systems, we review recent animal and human studies exploring the effects of stress on multiple memory systems. Apart from discussing the interaction between distinct memory systems in stressful situations, we will also outline the fundamental role of the amygdala in mediating such stress effects. Additionally, based on the methods applied in the herein discussed studies, we will discuss how memory translates into behaviour.

  18. Interaction between the effects of evaporation rate and amount of simulated rainfall on development of the free-living stages of Haemonchus contortus.

    Science.gov (United States)

    O'Connor, Lauren J; Kahn, Lewis P; Walkden-Brown, Stephen W

    2008-08-17

    A factorial experiment (3 x 4 x 2 x 3) was conducted in programmable incubators to investigate interaction between the effects of rainfall amount, rainfall distribution and evaporation rate on development of Haemonchus contortus to L3. Sheep faeces containing H. contortus eggs were incubated on sterilised soil under variable temperatures typical of summer in the Northern Tablelands of NSW, Australia. Simulated rainfall was applied in 1 of 3 amounts (12, 24 or 32 mm) and 4 distributions (a single event on the day after deposition, or the same total amount split in 2, 3 or 4 equal events over 2, 3 or 4 days, respectively). Samples were incubated at either a Low or High rate of evaporation (Low: 2.1-3.4 mm/day and High: 3.8-6.1 mm/day), and faeces and soil were destructively sampled at 4, 7 and 14 days post-deposition. Recovery of L3 from the soil (extra-pellet L3) increased over time (up to 0.52% at day 14) and with each increment of rainfall (12 mm: evaporation rate (0.01%) compared with the Low evaporation rate (0.31%). All rainfall amounts yielded significantly different recoveries of L3 under Low evaporation rates but there was no difference between the 12 and 24 mm treatments under the High evaporation rate. The distribution of simulated rainfall did not significantly affect recovery of infective larvae. Faecal moisture content was positively associated with L3 recovery, as was the ratio of cumulative precipitation and cumulative evaporation (P/E), particularly when measured in the first 4 days post-deposition. The results show that evaporation rate plays a significant role in regulating the influence of rainfall amount on the success of L3 transmission.

  19. Effects of mesh size in a flat evaporator and condenser cooling capacity on the thermal performance of a capillary pumped loop

    International Nuclear Information System (INIS)

    Boo, Joon Hong

    2000-01-01

    The thermal performance of a flat evaporator for Capillary Pumped Loop (CPL) applications was investigated. Two to four layers of coarse wire screen wicks were placed onto the heated surface to provide irregular passages for vapor flow. The evaporator and condenser were separated by a distance of 1.2 m and connected by individual liquid and vapor lines. The wall material was copper and the working fluid was ethanol. The experimental facility utilized a combination of capillary and gravitational forces for liquid return, and distribution over the evaporator surface. The tubing used for vapor and liquid lines was 9.35 mm or less in diameter and heat was removed from the condenser by convection of air. A heat flux of up to 4.9x10 4 W/m 2 was applied to a flat evaporator having dimensions of 100 mm by 200 mm, 20 mm thick. The thermal resistance of the system as well as the temperature characteristics of the system was investigated as the evaporator heat flux and the condenser cooling capacity varied. The performance of the evaporator and effect of condenser cooling capacity were analyzed and discussed

  20. Stress Effects on Multiple Memory System Interactions

    OpenAIRE

    Ness, Deborah; Calabrese, Pasquale

    2016-01-01

    Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory syst...

  1. Effects of polymer surface energy on morphology and properties of silver nanowire fabricated via nanoimprint and E-beam evaporation

    Science.gov (United States)

    Zhao, Zhi-Jun; Hwang, Soon Hyoung; Jeon, Sohee; Jung, Joo-Yun; Lee, Jihye; Choi, Dae-Geun; Choi, Jun-Hyuk; Park, Sang-Hu; Jeong, Jun-Ho

    2017-10-01

    In this paper, we demonstrate that use of different nanoimprint resins as a polymer pattern has a significant effect on the morphology of silver (Ag) nanowires deposited via an E-beam evaporator. RM-311 and Ormo-stamp resins are chosen as a polymer pattern to form a line with dimensions of width (100 nm) × space (100 nm) × height (120 nm) by using nanoimprint lithography (NIL). Their contact angles are then measured to evaluate their surface energies. In order to compare the properties of the Ag nanowires deposited on the various polymer patterns with different surface energies, hydrophobic surface treatment of the polymer pattern surface is implemented using self-assembled monolayers. In addition, gold and aluminum nanowires are fabricated for comparison with the Ag nanowires, with the differences in the nanowire morphologies being determined by the different atomic properties. The monocrystalline and polycrystalline structures of the various Ag nanowire formations are observed using transmission electron microscopy. In addition, the melting temperatures and optical properties of four kinds of Ag nanowire morphologies deposited on various polymer patterns are evaluated using a hot plate and an ultraviolet-visible (UV-vis) spectrometer, respectively. The results indicate that the morphology of the Ag nanowire determines the melting temperature and the transmission. We believe that these findings will greatly aid the development of NIL, along with physical evaporation and chemical deposition techniques, and will be widely employed in optics, biology, and surface wettability applications.

  2. Control of black hole evaporation?

    International Nuclear Information System (INIS)

    Ahn, Doyeol

    2007-01-01

    Contradiction between Hawking's semi-classical arguments and the string theory on the evaporation of a black hole has been one of the most intriguing problems in fundamental physics. A final-state boundary condition inside the black hole was proposed by Horowitz and Maldacena to resolve this contradiction. We point out that the original Hawking effect can also be regarded as a separate boundary condition at the event horizon for this scenario. Here, we found that the change of the Hawking boundary condition may affect the information transfer from the initial collapsing matter to the outgoing Hawking radiation during the evaporation process and as a result the evaporation process itself, significantly

  3. Bioheat model evaluations of laser effects on tissues: role of water evaporation and diffusion

    Science.gov (United States)

    Nagulapally, Deepthi; Joshi, Ravi P.; Thomas, Robert J.

    2011-03-01

    A two-dimensional, time-dependent bioheat model is applied to evaluate changes in temperature and water content in tissues subjected to laser irradiation. Our approach takes account of liquid-to-vapor phase changes and a simple diffusive flow of water within the biotissue. An energy balance equation considers blood perfusion, metabolic heat generation, laser absorption, and water evaporation. The model also accounts for the water dependence of tissue properties (both thermal and optical), and variations in blood perfusion rates based on local tissue injury. Our calculations show that water diffusion would reduce the local temperature increases and hot spots in comparison to simple models that ignore the role of water in the overall thermal and mass transport. Also, the reduced suppression of perfusion rates due to tissue heating and damage with water diffusion affect the necrotic depth. Two-dimensional results for the dynamic temperature, water content, and damage distributions will be presented for skin simulations. It is argued that reduction in temperature gradients due to water diffusion would mitigate local refractive index variations, and hence influence the phenomenon of thermal lensing. Finally, simple quantitative evaluations of pressure increases within the tissue due to laser absorption are presented.

  4. Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions

    KAUST Repository

    Alpatova, Alla; Alsaadi, Ahmad Salem; Ghaffour, NorEddine

    2018-01-01

    The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO scaling on the membrane surface.

  5. Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions.

    Science.gov (United States)

    Alpatova, A; Alsaadi, A; Ghaffour, N

    2018-06-05

    The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO 3 scaling on the membrane surface. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Annealing effect on physical properties of evaporated molybdenum oxide thin films for ethanol sensing

    Energy Technology Data Exchange (ETDEWEB)

    Touihri, S., E-mail: s_touihri@yahoo.fr [Unité de Physique des Dispositifs a semi-conducteurs, Faculté des sciences de Tunis, Tunis El Manar University, 2092 Tunis (Tunisia); Arfaoui, A.; Tarchouna, Y. [Unité de Physique des Dispositifs a semi-conducteurs, Faculté des sciences de Tunis, Tunis El Manar University, 2092 Tunis (Tunisia); Labidi, A. [Laboratoire Matériaux, Molécules et Applications, IPEST, BP 51 La Marsa 2070, Tunis (Tunisia); Amlouk, M. [Unité de Physique des Dispositifs a semi-conducteurs, Faculté des sciences de Tunis, Tunis El Manar University, 2092 Tunis (Tunisia); Bernede, J.C. [LUNAM, Universite de Nantes, Moltech Anjou, CNRS, UMR 6200, FSTN, 2 Rue de la houssiniere, BP 92208, Nantes F-44322 (France)

    2017-02-01

    Highlights: • Thermally grown molybdenum oxide films are amorphous, oxygen deficient and gas sensing. • Air or vacuum annealing transforms them into a sub-stoichiometric MoO{sub 3−x} phase. • The samples annealed at 500 °C in oxygen were crystallized and identified as pure orthorhombic MoO{sub 3} phase. • The conduction process and sensing mechanism of MoO{sub 3-x} to ethanol have been studied. - Abstract: This paper deals with some physical investigations on molybdenum oxide thin films growing on glass substrates by the thermal evaporation method. These films have been subjected to an annealing process under vacuum, air and oxygen at various temperatures 673, 723 and 773 K. First, the physical properties of these layers were analyzed by means of X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM) and optical measurements. These techniques have been used to investigate the oxygen index in MoO{sub x} properties during the heat treatment. Second, from the reflectance and transmittance optical measurements, it was found that the direct band gap energy value increased from 3.16 to 3.90 eV. Finally, the heat treatments reveal that the oxygen index varies in such molybdenum oxides showing noticeably sensitivity toward ethanol gas.

  7. The effect of NO2 on spectroscopic and structural properties of evaporated ruthenium phthalocyanine dimer

    International Nuclear Information System (INIS)

    Alagna, Lucilla; Capobianchi, Aldo; Paoletti, Anna Maria; Pennesi, Giovanna; Rossi, Gentilina; Casaletto, Maria Pia; Generosi, Amanda; Paci, Barbara; Albertini, Valerio Rossi

    2006-01-01

    The chemical interaction between NO 2 gas and dimeric ruthenium phthalocyanine (RuPc) 2 (Pc = phthalocyanine ligand) films has been investigated by different techniques: UV-Visible spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and Extended X-ray Absorption Fine Structure (EXAFS). The optical spectra in the Q band region (700-500 nm) registered 'in situ' enabled to follow the evolution of the process in real time indicating that a two steps reaction, showing two clear isosbestic points, occurs. The first phase was essentially characterised by: (a) the rapid disappearance of the 608 and 420 nm shoulders; (b) the intensity decrease of the main absorption peak and (c) the appearance of a new adsorption band centred around 510 nm. In the second step the remarkable feature is a further lowering of the main peak with the simultaneous decrease of the new 510 nm absorption. These spectral changes suggested that a chemical reaction occurred between NO 2 and ruthenium phthalocyanine with the formation of a radical species due to the macrocycle oxidation. The kinetics indicates that the adsorption of gas by the evaporated (RuPc) 2 film is a complex process involving more than one independent mechanism. XPS and EXAFS spectra collected before and after gas exposure showed that the central metals (Ru) were also involved in the oxidation process. The reversibility of the process has been also tested by treating the films at different temperatures, the original optical spectrum being not completely recovered

  8. Clustering and entrainment effects on the evaporation of dilute droplets in a turbulent jet

    Science.gov (United States)

    Dalla Barba, Federico; Picano, Francesco

    2018-03-01

    The evaporation of droplets within turbulent sprays involves unsteady, multiscale, and multiphase processes which make its comprehension and modeling capabilities still limited. The present work aims to investigate the dynamics of droplet vaporization within a turbulent spatial developing jet in dilute, nonreacting conditions. We address the problem considering a turbulent jet laden with acetone droplets and using the direct numerical simulation framework based on a hybrid Eulerian-Lagrangian approach and the point droplet approximation. A detailed statistical analysis of both phases is presented. In particular, we show how crucial is the preferential sampling of the vapor phase induced by the inhomogeneous localization of the droplets through the flow. Strong droplet preferential segregation develops suddenly downstream from the inflow section both within the turbulent core and the jet mixing layer. Two distinct mechanisms have been found to drive this phenomenon: the inertial small-scale clustering in the jet core and the intermittent dynamics of droplets across the turbulent-nonturbulent interface in the mixing layer, where dry air entrainment occurs. These phenomenologies strongly affect the overall vaporization process and lead to an impressive widening of the droplet size and vaporization rate distributions in the downstream evolution of the turbulent spray.

  9. Boron evaporation in thermally-driven seawater desalination: Effect of temperature and operating conditions

    KAUST Repository

    Alpatova, Alla

    2018-03-26

    The volatilization of boron in thermal desalination processes, namely multi-stage flash (MSF) and air-gap membrane distillation (AGMD) was investigated for the first time. This phenomenon was observed at feed temperatures above 55 °C in both studied processes. In simulated MSF process with two feeds, model boric acid and Red Sea water, boron concentration in distillate increased with feed temperature increase from 55 °C to 104 °C because of the increase in boric acid vapor pressure. Salinity and pH were the main factors controlling boron evaporation. The achieved boron concentrations in simulated MSF process were consistent with those measured in distillate samples collected from commercial MSF plants. The AGMD process also revealed a strong influence of operating temperature on boron removal. However, unlike MSF process, the boron concentration in AGMD permeate decreased with the feed temperature increase from 55 °C to 80 °C due probably to increase in vapor production and corresponding permeate dilution. When AGMD was operated in concentrating mode at a constant feed temperature of 80 °C, permeate boron concentration increased with process time due to concentration polarization and membrane fouling. A 10% flux decline observed after 21 h was attributed to CaCO scaling on the membrane surface.

  10. Sound Propagation in Saturated Gas-Vapor-Droplet Suspensions Considering the Effect of Transpiration on Droplet Evaporation

    Science.gov (United States)

    Kandula, Max

    2012-01-01

    The Sound attenuation and dispersion in saturated gas-vapor-droplet mixtures with evaporation has been investigated theoretically. The theory is based on an extension of the work of Davidson (1975) to accommodate the effects of transpiration on the linear particle relaxation processes of mass, momentum and energy transfer. It is shown that the inclusion of transpiration in the presence of mass transfer improves the agreement between the theory and the experimental data of Cole and Dobbins (1971) for sound attenuation in air-water fogs at low droplet mass concentrations. The results suggest that transpiration has an appreciable effect on both sound absorption and dispersion for both low and high droplet mass concentrations.

  11. Mixed phase evaporation source

    International Nuclear Information System (INIS)

    1975-01-01

    Apparatus for reducing convection current heat loss in electron beam evaporator is described. A material to be evaporated (evaporant) is placed in the crucible of an electron beam evaporation source along with a porous mass formed of a powdered or finely divided solid to act as an impedance to convection currents. A feed system is employed to replenish the supply of evaporant as it is vaporized

  12. Thermogravimetric analysis of fuel film evaporation

    Institute of Scientific and Technical Information of China (English)

    HU Zongjie; LI Liguang; YU Shui

    2006-01-01

    Thermogravimetric analysis (TGA) was compared with the petrochemical distillation measurement method to better understand the characteristics of fuel film evaporation at different wall tem- peratures. The film evaporation characteristics of 90# gasoline, 93# gasoline and 0# diesel with different initial thicknesses were investigated at different environmental fluxes and heating rates. The influences of heating rate, film thickness and environmental flux on fuel film evaporation for these fuels were found. The results showed that the environmental conditions in TGA were similar to those for fuel films in the internal combustion engines, so data from TGA were suitable for the analysis of fuel film evaporation. TGA could simulate the key influencing factors for fuel film evaporation and could investigate the basic quantificational effect of heating rate and film thickness. To get a rapid and sufficient fuel film evaporation, sufficiently high wall temperature is necessary. Evaporation time decreases at a high heating rate and thin film thickness, and intense gas flow is important to promoting fuel film evaporation. Data from TGA at a heating rate of 100℃/min are fit to analyze the diesel film evaporation during cold-start and warming-up. Due to the tense molecular interactions, the evaporation sequence could not be strictly divided according to the boiling points of each component for multicomponent dissolved mixture during the quick evaporation process, and the heavier components could vaporize before reaching their boiling points. The 0# diesel film would fully evaporate when the wall temperature is beyond 250℃.

  13. Effect of deposition rate on the microstructure of electron beam evaporated nanocrystalline palladium thin films

    Energy Technology Data Exchange (ETDEWEB)

    Amin-Ahmadi, B., E-mail: behnam.amin-ahmadi@ua.ac.be [Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Idrissi, H. [Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Galceran, M. [Université Libre de Bruxelles, Matters and Materials Department, 50 Av. FD Roosevelt CP194/03, 1050 Brussels (Belgium); Colla, M.S. [Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-la-Neuve (Belgium); Raskin, J.P. [Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Pardoen, T. [Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-la-Neuve (Belgium); Godet, S. [Université Libre de Bruxelles, Matters and Materials Department, 50 Av. FD Roosevelt CP194/03, 1050 Brussels (Belgium); Schryvers, D. [Electron Microscopy for Materials Science (EMAT), Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2013-07-31

    The influence of the deposition rate on the formation of growth twins in nanocrystalline Pd films deposited by electron beam evaporation is investigated using transmission electron microscopy. Statistical measurements prove that twin boundary (TB) density and volume fraction of grains containing twins increase with increasing deposition rate. A clear increase of the dislocation density was observed for the highest deposition rate of 5 Å/s, caused by the increase of the internal stress building up during deposition. Based on crystallographic orientation indexation using transmission electron microscopy, it can be concluded that a {111} crystallographic texture increases with increasing deposition rate even though the {101} crystallographic texture remains dominant. Most of the TBs are fully coherent without any residual dislocations. However, for the highest deposition rate (5 Å/s), the coherency of the TBs decreases significantly as a result of the interaction of lattice dislocations emitted during deposition with the growth TBs. The analysis of the grain boundary character of different Pd films shows that an increasing fraction of high angle grain boundaries with misorientation angles around 55–65° leads to a higher potential for twin formation. - Highlights: • Fraction of twinned grains and twin boundary density increase with deposition rate. • Clear increase of dislocation density was observed for the highest deposition rate. • A moderate increase of the mean grain size with increase of deposition rate is found. • For the highest deposition rate, the twin boundaries lose their coherency. • Fraction of high angle grain boundary (55–65) increases with deposition rate.

  14. Introducing ultrasonic falling film evaporator for moderate temperature evaporation enhancement.

    Science.gov (United States)

    Dehbani, Maryam; Rahimi, Masoud

    2018-04-01

    In the present study, Ultrasonic Falling Film (USFF), as a novel technique has been proposed to increase the evaporation rate of moderate temperature liquid film. It is a proper method for some applications which cannot be performed at high temperature, such as foodstuff industry, due to their sensitivity to high temperatures. Evaporation rate of sodium chloride solution from an USFF on an inclined flat plate compared to that for Falling Film without ultrasonic irradiation (FF) at various temperatures was investigated. The results revealed that produced cavitation bubbles have different effects on evaporation rate at different temperatures. At lower temperatures, size fluctuation and collapse of bubbles and in consequence induced physical effects of cavitation bubbles resulted in more turbulency and evaporation rate enhancement. At higher temperatures, the behavior was different. Numerous created bubbles joined together and cover the plate surface, so not only decreased the ultrasound vibrations but also reduced the evaporation rate in comparison with FF. The highest evaporation rate enhancement of 353% was obtained at 40 °C at the lowest Reynolds number of 250. In addition, the results reveal that at temperature of 40 °C, USFF has the highest efficiency compared to FF. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Cluster correlation effects in 12C+12C and 14N+10B fusion-evaporation reactions

    Directory of Open Access Journals (Sweden)

    Morelli L.

    2015-01-01

    Full Text Available The decay of highly excited states of 24Mg is studied in fusion evaporation events completely detected in charge in the reactions 12C+12C and 14N+10B at 95 and 80 MeV incident energy respectively. The comparison of light charged particles measured spectra with statistical model predictions suggests that the dominant reaction mechanism is compound nucleus (CN formation and decay. However, in both reactions, a discrepancy with statistical expectations is found for α particles detected in coincidence with Carbon, Oxigen and Neon residues. The comparison between the two reactions shows that this discrepancy is only partly explained by an entrance channel effect. Evidence for cluster correlations in excited 24Mg CN is suggested by the comparison between the measured and calculated branching ratios for the channels involving α particles.

  16. Study of the effect of wind speed on evaporation from soil through integrated modeling of the atmospheric boundary layer and shallow subsurface.

    Science.gov (United States)

    Davarzani, Hossein; Smits, Kathleen; Tolene, Ryan M; Illangasekare, Tissa

    2014-01-01

    In an effort to develop methods based on integrating the subsurface to the atmospheric boundary layer to estimate evaporation, we developed a model based on the coupling of Navier-Stokes free flow and Darcy flow in porous medium. The model was tested using experimental data to study the effect of wind speed on evaporation. The model consists of the coupled equations of mass conservation for two-phase flow in porous medium with single-phase flow in the free-flow domain under nonisothermal, nonequilibrium phase change conditions. In this model, the evaporation rate and soil surface temperature and relative humidity at the interface come directly from the integrated model output. To experimentally validate numerical results, we developed a unique test system consisting of a wind tunnel interfaced with a soil tank instrumented with a network of sensors to measure soil-water variables. Results demonstrated that, by using this coupling approach, it is possible to predict the different stages of the drying process with good accuracy. Increasing the wind speed increases the first stage evaporation rate and decreases the transition time between two evaporative stages (soil water flow to vapor diffusion controlled) at low velocity values; then, at high wind speeds the evaporation rate becomes less dependent on the wind speed. On the contrary, the impact of wind speed on second stage evaporation (diffusion-dominant stage) is not significant. We found that the thermal and solute dispersion in free-flow systems has a significant influence on drying processes from porous media and should be taken into account.

  17. Evaporation residue cross sections and average neutron multiplicities in the /sup 64/Ni+/sup 92/Zr and /sup 12/C+/sup 144/Sm reactions leading to /sup 156/Er

    Energy Technology Data Exchange (ETDEWEB)

    Janssens, R.V.F.; Holzmann, R.; Henning, W.; Khoo, T.L.; Lesko, K.T.; Stephans, G.S.F.; Radford, D.C.; Van den Berg, A.M.; Kuehn, W.; Ronningen, R.M.

    1986-11-27

    Evaporation residue cross sections and neutron multiplicity distributions have been measured for the /sup 12/C+/sup 144/Sm and /sup 64/Ni+/sup 92/Zr reactions leading to the same compound nucleous /sup 156/Er. Statistical model calculations can account for the data in the /sup 12/C-induced reaction. In contrast, the inhibition of neutron emission with respect to statistical model predictions seen in /sup 64/Ni+/sup 92/Zr cannot be explained even with the inclusion of the broad angular momentum distributions required to describe the fusion cross section data.

  18. Determining the Enthalpy of Vaporization of Salt Solutions Using the Cooling Effect of a Bubble Column Evaporator

    Science.gov (United States)

    Fan, Chao; Pashley, Richard M.

    2016-01-01

    The enthalpy of vaporization (?H[subscript vap]) of salt solutions is not easily measured, as a certain quantity of pure water has to be evaporated from a solution, at constant composition, and at a fixed temperature and pressure; then the corresponding heat input has to be measured. However, a simple bubble column evaporator (BCE) was used as a…

  19. Evaporation and Antievaporation Instabilities

    Directory of Open Access Journals (Sweden)

    Andrea Addazi

    2017-10-01

    Full Text Available We review (antievaporation phenomena within the context of quantum gravity and extended theories of gravity. The (antievaporation effect is an instability of the black hole horizon discovered in many different scenarios: quantum dilaton-gravity, f ( R -gravity, f ( T -gravity, string-inspired black holes, and brane-world cosmology. Evaporating and antievaporating black holes seem to have completely different thermodynamical features compared to standard semiclassical black holes. The purpose of this review is to provide an introduction to conceptual and technical aspects of (antievaporation effects, while discussing problems that are still open.

  20. On the uniqueness of the receding contact angle: effects of substrate roughness and humidity on evaporation of water drops.

    Science.gov (United States)

    Pittoni, Paola G; Lin, Chia-Hui; Yu, Teng-Shiang; Lin, Shi-Yow

    2014-08-12

    Could a unique receding contact angle be indicated for describing the wetting properties of a real gas-liquid-solid system? Could a receding contact angle be defined if the triple line of a sessile drop is not moving at all during the whole measurement process? To what extent is the receding contact angle influenced by the intrinsic properties of the system or the measurement procedures? In order to answer these questions, a systematic investigation was conducted in this study on the effects of substrate roughness and relative humidity on the behavior of pure water drops spreading and evaporating on polycarbonate (PC) surfaces characterized by different morphologies. Dynamic, advancing, and receding contact angles were found to be strongly affected by substrate roughness. Specifically, a receding contact angle could not be measured at all for drops evaporating on the more rugged PC surfaces, since the drops were observed strongly pinning to the substrate almost until their complete disappearance. Substrate roughness and system relative humidity were also found responsible for drastic changes in the depinning time (from ∼10 to ∼60 min). Thus, for measurement observations not sufficiently long, no movement of the triple line could be noted, with, again, the failure to find a receding contact angle. Therefore, to keep using concepts such as the receding contact angle as meaningful specifications of a given gas-liquid-solid system, the imperative to carefully investigate and report the inner characteristics of the system (substrate roughness, topography, impurities, defects, chemical properties, etc.) is pointed out in this study. The necessity of establishing methodological standards (drop size, measurement method, system history, observation interval, relative humidity, etc.) is also suggested.

  1. Analysis of a Free Surface Film from a Controlled Liquid Impinging Jet over a Rotating Disk Including Conjugate Effects, with and without Evaporation

    Science.gov (United States)

    Sankaran, Subramanian (Technical Monitor); Rice, Jeremy; Faghri, Amir; Cetegen, Baki M.

    2005-01-01

    A detailed analysis of the liquid film characteristics and the accompanying heat transfer of a free surface controlled liquid impinging jet onto a rotating disk are presented. The computations were run on a two-dimensional axi-symmetric Eulerian mesh while the free surface was calculated with the volume of fluid method. Flow rates between 3 and 15 1pm with rotational speeds between 50 and 200 rpm are analyzed. The effects of inlet temperature on the film thickness and heat transfer are characterized as well as evaporative effects. The conjugate heating effect is modeled, and was found to effect the heat transfer results the most at both the inner and outer edges of the heated surface. The heat transfer was enhanced with both increasing flow rate and increasing rotational speeds. When evaporative effects were modeled, the evaporation was found to increase the heat transfer at the lower flow rates the most because of a fully developed thermal field that was achieved. The evaporative effects did not significantly enhance the heat transfer at the higher flow rates.

  2. Possible Lingering Effects of Multiple Past Concussions

    Directory of Open Access Journals (Sweden)

    Grant L. Iverson

    2012-01-01

    Full Text Available Background. The literature on lingering or “cumulative” effects of multiple concussions is mixed. The purpose of this study was to examine whether athletes with a history of three or more concussions perform more poorly on neuropsychological testing or report more subjective symptoms during a baseline, preseason evaluation. Hypothesis. Athletes reporting three or more past concussions would perform more poorly on preseason neurocognitive testing. Study Design. Case-control study. Methods. An archival database including 786 male athletes who underwent preseason testing with a computerized battery (ImPACT was used to select the participants. Twenty-six athletes, between the ages of 17 and 22 with a history of three or more concussions, were identified. Athletes with no history of concussion were matched, in a case-control fashion, on age, education, self-reported ADHD, school, sport, and, when possible, playing position and self-reported academic problems. Results. The two groups were compared on the four neuropsychological composite scores from ImPACT using multivariate analysis of variance followed by univariate ANOVAs. MANOVA revealed no overall significant effect. Exploratory ANOVAs were conducted using Verbal Memory, Visual Memory, Reaction Time, Processing Speed, and Postconcussion Scale composite scores as dependent variables. There was a significant effect for only the Verbal Memory composite. Conclusions. Although inconclusive, the results suggest that some athletes with multiple concussions could have lingering memory deficits.

  3. Emergent and multiplicative effect in a cluster

    Directory of Open Access Journals (Sweden)

    I. V. Linev

    2016-01-01

    Full Text Available The concept “Cluster” of domestic and foreign literature traditionally is considered as administrative and organizational education. At the same time he represents the social and economic object created for life support of the person. The cluster is considered as system object. The main signs are defined and his life cycle is considered. Cluster self-organization takes place stages: growth of organizational weight and effects, market threats and restrictions interfering growth of organizational weight. Development of clusters requires the state support in various forms which is offered to be carried out at various stages depending on his type. The cluster is considered as the economic system possessing an emergent which dynamic aspect is the synergy, the receiving multiplicative effect causing an opportunity. The quantitative assessment of size of the listed effects represents rather complex challenge, at the same time there is a number of the factors which are with her in directly proportional dependence. The synergy which is present at a cluster allows to gain social and economic effect of his functioning by means of integration of effects of all structural elements bigger, than their simple sum. The emergent in a cluster causes increase of productivity at the expense of innovations in technological and organizational spheres and stimulations of the birth of new businesses. The multiplicative effect arising in a cluster provides incremental nature of economic results. It is possible to refer the following to the main economic results received from creation and development of clusters: decrease in transactional and transformational expenses and costs of formation and further use of infrastructure, economy of costs of introduction and development of the high and innovative technologies, optimization of logistic and information expenses, increase of business reputation and investment appeal.

  4. Evaporator Cleaning Studies

    International Nuclear Information System (INIS)

    Wilmarth, W.R.

    1999-01-01

    Operation of the 242-16H High Level Waste Evaporator proves crucial to liquid waste management in the H-Area Tank Farm. Recent operational history of the Evaporator showed significant solid formation in secondary lines and in the evaporator pot. Additional samples remain necessary to ensure material identity in the evaporator pot. Analysis of these future samples will provide actinide partitioning information and dissolution characteristics of the solid material from the pot to ensure safe chemical cleaning

  5. Evaporation and Climate Change

    NARCIS (Netherlands)

    Brandsma, T.

    1993-01-01

    In this article the influence of climate change on evaporation is discussed. The emphasis is on open water evaporation. Three methods for calculating evaporation are compared considering only changes in temperature and factors directly dependent on temperature. The Penman-method is used to

  6. Effects of near surface soil moisture profiles during evaporation on far-field ground-penetrating radar data: A numerical study

    KAUST Repository

    Moghadas, Davood; Jadoon, Khan; Vanderborght, Jan P.; Lambot, Sé bastien; Vereecken, Harry

    2013-01-01

    We theoretically investigated the effect of vapor flow on the drying front that develops in soils when water evaporates from the soil surface and on GPR data. The results suggest the integration of the full-wave GPR model with a coupled water, vapor

  7. Effects of Sport Climbing on Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Julia Steimer

    2017-12-01

    Full Text Available Multiple sclerosis (MS is an autoimmune and neurodegenerative disease of the central nervous system (CNS with different types of disease courses (relapsing-remitting, secondary-progressive, primary progressive that leads to physical as well as mental disability. The symptoms comprise paresis or/and paralysis, ataxia, bladder dysfunction, visual problems as well as effects on cognition. There is limited data regarding the possible effects of sport climbing respectively therapeutic climbing on patients with MS. Sport climbing offers many potentially beneficial effects for patients with MS since there are effects on coordination, muscular strength, and cognition to name the most relevant ones. Also, disease models in rodents point toward such positive outcomes of climbing. Therefore, we assessed the currently available research literature on general effects of physical exercise, impact of climbing on body and mind and therapeutic climbing for prevention or therapy for the treatment of MS. The sparse published controlled trials that investigated this sport activity on different groups of patients with neurological or geriatric diseases grossly differ in study design and outcome parameters. Nevertheless, it appears that climbing offers the opportunity to improve some of the symptoms of patients with MS and can contribute to an enhanced quality of life.

  8. Effects of NaF evaporation during low temperature Cu(In,Ga)Se{sub 2} growth

    Energy Technology Data Exchange (ETDEWEB)

    Bissig, B., E-mail: benjamin.bissig@empa.ch; Reinhard, P.; Pianezzi, F.; Hagendorfer, H.; Nishiwaki, S.; Buecheler, S.; Tiwari, A.N.

    2015-05-01

    Co-evaporation of NaF during the 3{sup rd} stage of the low temperature Cu(In,Ga)Se{sub 2} multi-stage process is compared to post-deposition treatment (PDT) with NaF in view of their influence on the electronic and structural properties. In case of NaF co-evaporation, quantum efficiency losses in the near infrared region and thus lower short circuit current density cause a reduced efficiency compared to solar cells prepared with NaF PDT. The formation of a deep defect with activation energy of ~ 250 meV is measured by capacitance spectroscopy and can explain the deteriorated performance in such devices. In addition, NaF co-evaporation during the 3{sup rd} stage causes reduced grain size in the top part of Cu(In,Ga)Se{sub 2} and altered In, Ga, and Cu distribution. - Highlights: • NaF was co-evaporated in a low temperature CIGS process during and after the 3rd stage. • CIGS grains size is reduced in the top 300 nm when NaF is co-evaporated. • C-f measurements indicate deep defect formation when NaF is co-evaporated.

  9. Mass-loss evolution of close-in exoplanets: Evaporation of hot Jupiters and the effect on population

    International Nuclear Information System (INIS)

    Kurokawa, H.; Nakamoto, T.

    2014-01-01

    During their evolution, short-period exoplanets may lose envelope mass through atmospheric escape owing to intense X-ray and extreme ultraviolet (XUV) radiation from their host stars. Roche-lobe overflow induced by orbital evolution or intense atmospheric escape can also contribute to mass loss. To study the effects of mass loss on inner planet populations, we calculate the evolution of hot Jupiters considering mass loss of their envelopes and thermal contraction. Mass loss is assumed to occur through XUV-driven atmospheric escape and the following Roche-lobe overflow. The runaway effect of mass loss results in a dichotomy of populations: hot Jupiters that retain their envelopes and super Earths whose envelopes are completely lost. Evolution primarily depends on the core masses of planets and only slightly on migration history. In hot Jupiters with small cores (≅ 10 Earth masses), runaway atmospheric escape followed by Roche-lobe overflow may create sub-Jupiter deserts, as observed in both mass and radius distributions of planetary populations. Comparing our results with formation scenarios and observed exoplanets populations, we propose that populations of closely orbiting exoplanets are formed by capturing planets at/inside the inner edges of protoplanetary disks and subsequent evaporation of sub-Jupiters.

  10. Mass-loss evolution of close-in exoplanets: Evaporation of hot Jupiters and the effect on population

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, H. [Department of Physics, Nagoya Univsersity, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan); Nakamoto, T., E-mail: kurokawa@nagoya-u.jp [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2014-03-01

    During their evolution, short-period exoplanets may lose envelope mass through atmospheric escape owing to intense X-ray and extreme ultraviolet (XUV) radiation from their host stars. Roche-lobe overflow induced by orbital evolution or intense atmospheric escape can also contribute to mass loss. To study the effects of mass loss on inner planet populations, we calculate the evolution of hot Jupiters considering mass loss of their envelopes and thermal contraction. Mass loss is assumed to occur through XUV-driven atmospheric escape and the following Roche-lobe overflow. The runaway effect of mass loss results in a dichotomy of populations: hot Jupiters that retain their envelopes and super Earths whose envelopes are completely lost. Evolution primarily depends on the core masses of planets and only slightly on migration history. In hot Jupiters with small cores (≅ 10 Earth masses), runaway atmospheric escape followed by Roche-lobe overflow may create sub-Jupiter deserts, as observed in both mass and radius distributions of planetary populations. Comparing our results with formation scenarios and observed exoplanets populations, we propose that populations of closely orbiting exoplanets are formed by capturing planets at/inside the inner edges of protoplanetary disks and subsequent evaporation of sub-Jupiters.

  11. Effectiveness of Combined Tear Film Therapy in Patients with Evaporative Dry Eye with Short Tear Film Breakup Time.

    Science.gov (United States)

    Kim, Yung Hui; Kang, Yeon Soo; Lee, Hyo Seok; Choi, Won; You, In Cheon; Yoon, Kyung Chul

    2017-10-01

    The aim of this study was to evaluate the effectiveness of combined tear film therapy targeted to aqueous, mucin, and lipid layers in patients with refractory evaporative dry eye (EDE) with short tear film breakup time (TBUT). The patients who had EDE with short TBUT and severe symptoms refractory to artificial tears were treated with hyaluronic acid (HA) 0.15% and diquafosol tetrasodium (DQS) 3% (Group 1), HA and carbomer-based lipid-containing eyedrops (Liposic EDO Gel, LPO) (Group 2), or HA, DQS, and LPO (Group 3). Ocular Surface Disease Index (OSDI) score, visual analog scale (VAS) symptom score, TBUT, Schirmer score, and corneal and conjunctival staining scores were evaluated, and noninvasive tear film breakup time (NIBUT) and tear meniscus height were measured using Keratograph ® 5 M before and 1 and 3 months after treatment. OSDI scores, VAS scores, TBUT, and NIBUT were improved at 1 and 3 months after treatment in all groups (all P film layers was most effective in improving ocular symptoms and tear film quality.

  12. Phenomics allows identification of genomic regions affecting maize stomatal conductance with conditional effects of water deficit and evaporative demand.

    Science.gov (United States)

    Prado, Santiago Alvarez; Cabrera-Bosquet, Llorenç; Grau, Antonin; Coupel-Ledru, Aude; Millet, Emilie J; Welcker, Claude; Tardieu, François

    2018-02-01

    Stomatal conductance is central for the trades-off between hydraulics and photosynthesis. We aimed at deciphering its genetic control and that of its responses to evaporative demand and water deficit, a nearly impossible task with gas exchanges measurements. Whole-plant stomatal conductance was estimated via inversion of the Penman-Monteith equation from data of transpiration and plant architecture collected in a phenotyping platform. We have analysed jointly 4 experiments with contrasting environmental conditions imposed to a panel of 254 maize hybrids. Estimated whole-plant stomatal conductance closely correlated with gas-exchange measurements and biomass accumulation rate. Sixteen robust quantitative trait loci (QTLs) were identified by genome wide association studies and co-located with QTLs of transpiration and biomass. Light, vapour pressure deficit, or soil water potential largely accounted for the differences in allelic effects between experiments, thereby providing strong hypotheses for mechanisms of stomatal control and a way to select relevant candidate genes among the 1-19 genes harboured by QTLs. The combination of allelic effects, as affected by environmental conditions, accounted for the variability of stomatal conductance across a range of hybrids and environmental conditions. This approach may therefore contribute to genetic analysis and prediction of stomatal control in diverse environments. © 2017 John Wiley & Sons Ltd.

  13. New models for droplet heating and evaporation

    KAUST Repository

    Sazhin, Sergei S.

    2013-02-01

    A brief summary of new models for droplet heating and evaporation, developed mainly at the Sir Harry Ricardo Laboratory of the University of Brighton during 2011-2012, is presented. These are hydrodynamic models for mono-component droplet heating and evaporation, taking into account the effects of the moving boundary due to evaporation, hydrodynamic models of multi-component droplet heating and evaporation, taking and not taking into account the effects of the moving boundary, new kinetic models of mono-component droplet heating and evaporation, and a model for mono-component droplet evaporation, based on molecular dynamics simulation. The results, predicted by the new models are compared with experimental data and the prehctions of the previously developed models where possible. © 2013 Asian Network for Scientific Information.

  14. Effects of maternal inhalation of gasoline evaporative condensates on sensory function in rat offspring

    Science.gov (United States)

    In order to assess potential health effects resulting from exposure to ethanol-gasoline blend vapors, we previously conducted neurophysiological assessment of sensory function following gestational exposure to 100% ethanol vapor (Herr et al., Toxicologist, 2012). For comparison p...

  15. Effects of multiple spreaders in community networks

    Science.gov (United States)

    Hu, Zhao-Long; Ren, Zhuo-Ming; Yang, Guang-Yong; Liu, Jian-Guo

    2014-12-01

    Human contact networks exhibit the community structure. Understanding how such community structure affects the epidemic spreading could provide insights for preventing the spreading of epidemics between communities. In this paper, we explore the spreading of multiple spreaders in community networks. A network based on the clustering preferential mechanism is evolved, whose communities are detected by the Girvan-Newman (GN) algorithm. We investigate the spreading effectiveness by selecting the nodes as spreaders in the following ways: nodes with the largest degree in each community (community hubs), the same number of nodes with the largest degree from the global network (global large-degree) and randomly selected one node within each community (community random). The experimental results on the SIR model show that the spreading effectiveness based on the global large-degree and community hubs methods is the same in the early stage of the infection and the method of community random is the worst. However, when the infection rate exceeds the critical value, the global large-degree method embodies the worst spreading effectiveness. Furthermore, the discrepancy of effectiveness for the three methods will decrease as the infection rate increases. Therefore, we should immunize the hubs in each community rather than those hubs in the global network to prevent the outbreak of epidemics.

  16. Effects of the generator and evaporator temperature differences on a double absorption heat transformer—Different control strategies on utilizing heat sources

    International Nuclear Information System (INIS)

    Wang, Hanzhi; Li, Huashan; Bu, Xianbiao; Wang, Lingbao

    2017-01-01

    Highlights: • Effects of the GETD on the DAHT system performance are analyzed. • Three different configurations are compared in detail. • Suggestions on the heat source control strategies are given. - Abstract: The combination of the absorption heat transformer with renewable energy systems, like solar thermal systems, is raising more and more concern. In those combined systems the strategies on utilizing heat sources can affect system thermodynamic performance significantly. Therefore, this study presents a detailed analysis on the effect of the heat source temperature and different heat source flow patterns on the performance of a double absorption heat transformer (DAHT). A detailed comparative study is carried out to clarify the impact of the generator and evaporator temperature differences (GETD) on the coefficient of performance (COP), exergy efficient (ECOP), exergy destruction rates in the individual components and heat transfer areas needed for each component. The results show that the generator, condenser and absorber-evaporator are responsible for most of the exergy destruction rate in the DAHT system; the parallel-flow configuration (the generator temperature is equal to the evaporator temperature) performs better under the high gross temperature lift conditions; in the case of the counter-flow configuration (the generator temperature is relatively higher), better performance can be obtained in both the COP and ECOP under the proper heat source temperature (85 and 95 °C); the fair-flow configuration (higher temperature in the evaporator) is not recommended in this paper due to no advantages found in either thermodynamic performance or system size.

  17. Effective dielectric functions of samples obtained by evaporation of alkali halides

    International Nuclear Information System (INIS)

    Sturm, J.; Grosse, P.; Theiss, W.

    1991-01-01

    This paper investigates the dielectric properties of inhomogeneous samples consisting of small alkali halide particles (NaCl, KBr) on gold-coated substrates. Our reflection measurements in the far infrared can be simulated as a thin layer of the power with an effective dielectric function on a perfectly reflecting substrate. Scanning electron micrographs provide useful information about sample topology. Several mixing formulas (e.g. the Maxwell-Garnett, the Bruggeman- and the Looyenga-formula) lead to effective dielectric functions neglecting the individual arrangement of the particles. The essence of our work is that, in contrast, the general ansatz of the Bergman spectral representation has to be employed in order to take into account topology effects on the dielectric function based on the so-called spectral density g adjustable to the specific situation. (orig.)

  18. Dew Point Evaporative Comfort Cooling

    Science.gov (United States)

    2012-11-01

    Multiple DASs were installed at Fort Carson, and the data from all the sensors were stored and partially processed on Campbell Scientific Data Loggers. The...evaporative cooling technologies would be expected to easily overcome utility- scale water withdrawal rates. As an example, an evaluation of an...Ambient pressure Outdoor Setra 276 1% of full scale Pyranometer Horizontal Campbell Scientific CS300 5% of daily total The OAT measurement has an

  19. Design and development of a split-evaporator heat-pump system

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, M.H.; Penoncello, S.G.

    1981-12-01

    The designs and experimental results of three types of multiple source heat pumps are presented. The three designs are the parallel evaporator, the series evaporator, and the parallel evaporator with active subcooling, with the parallel evaporator with the active subcooling showing the most promise for solving the problem of defrosting of air evaporators. Three design procedures for multiple source heat pumps were developed. One of these is a hand calculational procedure, the others are computer based. The models are based upon the refrigerant flow rate, rather than the refrigeration effect of the evaporator. The technical results of a detailed analytical and experimental model of the heat transfer rates on a flat plate ice maker are presented. It is shown, both analytically and experimentally, that the temperature of the air surrounding the flat plate ice maker can play a dominant role in the rate of ice formation. A detailed weather analysis for forty cities located throughout the nation was completed. These data were processed to allow easy computation of thermal storage requirements for full, partial, or minimum ACES systems, or upon other design requirements, such as off-peak air conditioning. The results of an innovative ice storage system that is thermally coupled to the earth are described. This system has the potential for meeting both the off-peak air conditioning needs and the thermal storage requirements for the heating cycle. An economic and energy comparison of multiple source heat pumps with ACES, and air-to-air heat pump systems is presented.

  20. The effect of fibers on the loss of water by evaporation and shrinkage of concrete

    Directory of Open Access Journals (Sweden)

    N. M. P. Pillar

    Full Text Available Shrinkage is one of the least desirable attributes in concrete. Large areas of exposed concrete surfaces , such as in shotcrete tunnel linings, where it is practically impossible to make a moist cure, are highly susceptible to plastic shrinkage at early ages. The autogenous and drying shrinkage can lead to states of greater than threshold strength, causing fracture, mechanical damage and lack of durability of concrete structures. The addition of fibers can greatly reduce plastic shrinkage, but has limited effect in mitigating autogenous and drying shrinkage. To evaluate the performance of polypropylene and steel fibers to understand their effect on shrinkage of concrete, a study was carried out to relate the loss of water from the paste and the shrinkage during the first 28 days of age, and compare it with a control mix without fiber. The loss of water was obtained by the weight loss of the specimens at different ages, since the only component that could contribute for the loss of weight was the water lost by the paste of the concrete. And the paste itself is the only source of shrinkage. Uniaxial compressive tests from very early ages enabled the determination of time when plastic shrinkage ended. It was observed that the control concrete mix lost three times more water and developed plastic and drying shrinkage 60 % higher than the fiber reinforced concrete mixes. It was possible to demonstrate that the reduced loss of water caused by the incorporation of fibers is related to the mitigation of plastic shrinkage. It was observed that the fibers are effective to restrain the movement of water through the cement paste in the plastic state, however such effect is limited after concrete starts the hardening state.

  1. Search for entrance channel effects in fusion reactions via neutron evaporation

    International Nuclear Information System (INIS)

    Ajay Kumar; Kaur, J.; Kumar, A.; Singh, G.; Govil, I.M.; Rakesh Kumar; Datta, S.K.; Chatterjee, M.B.; Yogi, B.K.

    2001-01-01

    It is generally expected that the compound nuclei formed at the given excitation energies and the angular momenta follow a statistical decay pattern independent of a particular reaction that led to fusion. In order to search the entrance channel effects in the decay of compound nucleus, the reaction 16 O + 64 Zn at oxygen beam energy of 91 MeV and 95 MeV are investigated

  2. Effect of deposition temperature on electron-beam evaporated polycrystalline silicon thin-film and crystallized by diode laser

    Energy Technology Data Exchange (ETDEWEB)

    Yun, J., E-mail: j.yun@unsw.edu.au; Varalmov, S.; Huang, J.; Green, M. A. [School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, New South Wales 2052 (Australia); Kim, K. [School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, New South Wales 2052 (Australia); Suntech R and D Australia, Botany, New South Wales 2019 (Australia)

    2014-06-16

    The effects of the deposition temperature on the microstructure, crystallographic orientation, and electrical properties of a 10-μm thick evaporated Si thin-film deposited on glass and crystallized using a diode laser, are investigated. The crystallization of the Si thin-film is initiated at a deposition temperature between 450 and 550 °C, and the predominant (110) orientation in the normal direction is found. Pole figure maps confirm that all films have a fiber texture and that it becomes stronger with increasing deposition temperature. Diode laser crystallization is performed, resulting in the formation of lateral grains along the laser scan direction. The laser power required to form lateral grains is higher in case of films deposited below 450 °C for all scan speeds. Pole figure maps show 75% occupancies of the (110) orientation in the normal direction when the laser crystallized film is deposited above 550 °C. A higher density of grain boundaries is obtained when the laser crystallized film is deposited below 450 °C, which limits the solar cell performance by n = 2 recombination, and a performance degradation is expected due to severe shunting.

  3. Atmospheric dry deposition in the vicinity of the Salton Sea, California - II: Measurement and effects of an enhanced evaporation system

    Science.gov (United States)

    Alonso, R.; Bytnerowicz, A.; Yee, J.L.; Boarman, W.I.

    2005-01-01

    A study was conducted to determine the effects of salt spray drift from pilot technologies employed by the US Bureau of Reclamation on deposition rates of various air-born ions. An enhanced evaporation system (EES) was tested in the field at the Salton Sea, California. Dry deposition of NO3-, NH4+, SO42-, Cl-, Ca2+, Na+, K+ and Se was assessed by using nylon filters and branches of natural vegetation exposed for one-week long periods. The simultaneous exposure of both lyophilized branches and branches of live plants offered important information highlighting the dynamics of deposited ions on vegetation. The EES significantly increased the deposition rates of Cl-, SO42- and Na+ in an area of about 639-1062 m surrounding the sprayers. Similarly, higher deposition of Ca 2+ and K+ caused by the EES was detected only when deposition was assessed using nylon filters or lyophilized branches. Deposition fluxes of NO3-, NH4+ and Se were not affected by the spraying system. Techniques for measuring dry deposition and calculating landscape-level depositional loads in non-forested systems need further development. ?? 2005 Elsevier Ltd. All rights reserved.

  4. Wetting and evaporation of binary mixture drops.

    Science.gov (United States)

    Sefiane, Khellil; David, Samuel; Shanahan, Martin E R

    2008-09-11

    Experimental results on the wetting behavior of water, methanol, and binary mixture sessile drops on a smooth, polymer-coated substrate are reported. The wetting behavior of evaporating water/methanol drops was also studied in a water-saturated environment. Drop parameters (contact angle, shape, and volume) were monitored in time. The effects of the initial relative concentrations on subsequent evaporation and wetting dynamics were investigated. Physical mechanisms responsible for the various types of wetting behavior during different stages are proposed and discussed. Competition between evaporation and hydrodynamic flow are evoked. Using an environment saturated with water vapor allowed further exploration of the controlling mechanisms and underlying processes. Wetting stages attributed to differential evaporation of methanol were identified. Methanol, the more volatile component, evaporates predominantly in the initial stage. The data, however, suggest that a small proportion of methanol remained in the drop after the first stage of evaporation. This residual methanol within the drop seems to influence subsequent wetting behavior strongly.

  5. Is evaporative colling important for shallow clouds?

    Science.gov (United States)

    Gentine, P.; Park, S. B.; Davini, P.; D'Andrea, F.

    2017-12-01

    We here investigate and test using large-eddy simulations the hypothesis that evaporative cooling might not be crucial for shallow clouds. Results from various Shallow convection and stratocumulus LES experiments show that the influence of evaporative cooling is secondary compared to turbulent mixing, which dominates the buoyancy reversal. In shallow cumulus subising shells are not due to evaporative cooling but rather reflect a vortical structure, with a postive buoyancy anomaly in the core due to condensation. Disabling evaporative cooling has negligible impact on this vortical structure and on buoyancy reversal. Similarly in non-precipitating stratocumuli evaporative cooling is negeligible copmared to other factors, especially turbulent mixing and pressure effects. These results emphasize that it may not be critical to icnlude evaporative cooling in parameterizations of shallow clouds and that it does not alter entrainment.

  6. Effect of combination dope composition and evaporation time on the separation performance of cellulose acetate membrane for demak brackish water treatment

    Directory of Open Access Journals (Sweden)

    Kusworo Tutuk Djoko

    2017-01-01

    Full Text Available The coastal areas in Indonesia often have a problem of clean water lack, because the water is classified as brackish water. Therefore, this research investigated the fabrication of CA membranes using phase inversion method for brackish water treatment. Investigation was conducted to study the effect of combination dope composition and evaporation time on separation performance and morphology of the memrbane. Membrane was fabricated by dry-wet phase inversion technique with variation of polymer concentration 17, 18 and 20 wt% in the total solid and evaporation time of 5, 10 and 15 seconds, respectively. The asymmetric membranes were characterized by permeability test through rejection and flux measurements using brackish water as feed. The experimental results from SEM images analysis showed that all the membranes have a thin small porous layer and thicker sub-structure of larger porous layer formed asymmetric membrane. Moreover, the greater polymer concentration is resulting smaller pore size and smaller membrane porosity. The longer evaporation time was also resulted in denser membrane active layer. The best membrane performance was observed at the composition of 20 wt% CA polymer, 1 wt % polyethylene glycol with the solvent evaporation time of 15 seconds.

  7. Study of the effects of elevated pressure and temperature on the evaporation of a single fuel droplet

    International Nuclear Information System (INIS)

    Memon, A.A.; Memon, M.A.; Durrani, H.A.

    1991-01-01

    The experimental studies were made on the evaporation of single fuel droplet in high pressure and high temperature gaseous environments. The time history of the size and the temperature of an evaporating droplet suspended on a fine quartz thread was recorded using a movie camera and an oscilloscope. The fuel used was n-heptane. The experimental range of conditions consists of gas pressure from 0 atg to 50 atg, gas temperature from 100 c to 500 c which correspond to the subcritical, critical and supercritical state of a droplet. The evaporation rate, the life time and the wet-bulb temperature of a droplet were obtained. The results showed that the temperature of an evaporating droplet increased with an increase in gas pressure and temperature, through it did not reach the critical temperature of fuel even at supercritical environments. It was evident that with an increase in gas pressure, the evaporation rate increased at high gas temperature while it decreased at low gas temperature. (author)

  8. Effect of some Evaporation Matters on Storability of Sunflower ( Helianthus annuus L.) Seed.

    Science.gov (United States)

    El-Saidy, Aml E A; El-Hai, K M Abd

    This study focuses on finding compounds that are safe to humans and environment, such as propionic and acetic acids that may provide an alternative control of seed-borne pathogens and decrease seed deterioration during storage. The objectives of this study were to reduce sunflower seed deterioration and improve the viability of sunflower seed using environmentally safe organic acids. Propionic and acetic acids were applied on sunflower seed at different concentrations under laboratory conditions during different storage periods. After 6 months storage period, the viability of sunflower seed as well as morphological and physiological characteristics of seedlings were evaluated under greenhouse conditions. Laboratory experiment was conducted in a factorial completely randomized design and randomized complete block design for greenhouse experiment. Propionic and acetic acids at different concentrations showed inhibitory effects on the presence of different fungal genera in all storage periods. Propionic acid was most effective followed by acetic acid. Increasing storage periods from 0-6 months significantly decreased germination percentage, germination energy, seedling characters, survived healthy seedlings and seed oil and protein percentages but dead and rotted seeds, as well as rotted seedlings were increased. Treating sunflower seeds with propionic acid (100%) improved germination criteria, seedling characters and seed chemical characters as well as survival seedlings and minimized the dead seeds, rotted seeds and rotted seedlings as compared with the control under all storage periods. Under greenhouse conditions, the maximum growth parameter and physiological characters (chlorophylls a, b, carotenoids and total phenols) were recorded from seed treated with 100% propionic acid after 6 months of storage. It may be concluded that propionic and acetic acids vapors can have considerable fungicidal activity against sunflower pathogens and improve seed viability

  9. Portable brine evaporator unit, process, and system

    Science.gov (United States)

    Hart, Paul John; Miller, Bruce G.; Wincek, Ronald T.; Decker, Glenn E.; Johnson, David K.

    2009-04-07

    The present invention discloses a comprehensive, efficient, and cost effective portable evaporator unit, method, and system for the treatment of brine. The evaporator unit, method, and system require a pretreatment process that removes heavy metals, crude oil, and other contaminates in preparation for the evaporator unit. The pretreatment and the evaporator unit, method, and system process metals and brine at the site where they are generated (the well site). Thus, saving significant money to producers who can avoid present and future increases in transportation costs.

  10. Response of bacteria in wastewater sludge to moisture loss by evaporation and effect of moisture content on bacterial inactivation by ionizing radiation.

    OpenAIRE

    Ward, R L; Yeager, J G; Ashley, C S

    1981-01-01

    Two studies were carried out to determine the influence of moisture content of the survival of bacteria in raw wastewater sludge. The first study involved the effect of water loss by evaporation on the bacterial population. The second used these dewatered samples to measure the effects of moisture content on the inactivation of bacteria sludge by ionizing radiation. Both studies involved survival measurements of six representative fecally associated bacteria grown separately in sterilized slu...

  11. Effect of projectile structure on evaporation residue yields in incomplete fusion reactions

    CERN Document Server

    Babu, K S; Sudarshan, K; Shrivastava, B D; Goswami, A; Tomar, B S

    2003-01-01

    The excitation functions of heavy residues, representing complete and incomplete fusion products, produced in the reaction of sup 1 sup 2 C and sup 1 sup 3 C on sup 1 sup 8 sup 1 Ta have been measured over the projectile energy range of 5 to 6.5 MeV/nucleon by the recoil catcher method and off-line gamma-ray spectrometry. Comparison of the measured excitation functions with those calculated using the PACE2 code based on the statistical model revealed the occurrence of incomplete fusion reactions in the formation of alpha emission products. The fraction of incomplete fusion cross sections in the sup 1 sup 2 C + sup 1 sup 8 sup 1 Ta reaction was found to be higher, by a factor of approx 2, than that in the sup 1 sup 3 C + sup 1 sup 8 sup 1 Ta reaction. The results have been discussed in terms of the effect of alpha cluster structure of the projectile on incomplete fusion reactions.

  12. Effect of vacuum annealing on evaporated pentacene thin films for memory device applications

    International Nuclear Information System (INIS)

    Gayathri, A.G.; Joseph, C.M.

    2016-01-01

    Graphical abstract: Switching of ITO/pentacene/Al thin films for different annealing temperatures. - Highlights: • Memory device performance in pentacene improved considerably with annealing. • ON/OFF ratio of the pentacene device increases due to annealing. • Threshold voltage reduces from 2.55 V to 1.35 V due to annealing. • Structure of pentacene thin films is also dependent on annealing temperature. - Abstract: Thin films of pentacene were deposited thermally onto glass substrates and annealed at 323 K, 373 K, 423 K, 473 K and 523 K in high vacuum. Effect of annealing on the morphological and structural properties of these films was studied. X-ray diffraction patterns confirmed the crystalline nature of the films. Electrical studies for the use as write once read many (WORM) memory devices were done for the vacuum deposited pentacene thin films on indium tin oxide coated glass. Due to annealing, a sharp increase in the ON/OFF ratio of current and a decrease in threshold voltage were observed at around 373 K. This device showed a stable switching with an ON/OFF current ratio as high as 10 9 and a switching threshold voltage of 1.35 V. The performance of the device degraded above 423 K due to the changes in the crystallinity of the film.

  13. Effect of vacuum annealing on evaporated pentacene thin films for memory device applications

    Energy Technology Data Exchange (ETDEWEB)

    Gayathri, A.G., E-mail: gaythri305@yahoo.com; Joseph, C.M., E-mail: cmjoseph@rediffmail.com

    2016-09-15

    Graphical abstract: Switching of ITO/pentacene/Al thin films for different annealing temperatures. - Highlights: • Memory device performance in pentacene improved considerably with annealing. • ON/OFF ratio of the pentacene device increases due to annealing. • Threshold voltage reduces from 2.55 V to 1.35 V due to annealing. • Structure of pentacene thin films is also dependent on annealing temperature. - Abstract: Thin films of pentacene were deposited thermally onto glass substrates and annealed at 323 K, 373 K, 423 K, 473 K and 523 K in high vacuum. Effect of annealing on the morphological and structural properties of these films was studied. X-ray diffraction patterns confirmed the crystalline nature of the films. Electrical studies for the use as write once read many (WORM) memory devices were done for the vacuum deposited pentacene thin films on indium tin oxide coated glass. Due to annealing, a sharp increase in the ON/OFF ratio of current and a decrease in threshold voltage were observed at around 373 K. This device showed a stable switching with an ON/OFF current ratio as high as 10{sup 9} and a switching threshold voltage of 1.35 V. The performance of the device degraded above 423 K due to the changes in the crystallinity of the film.

  14. Microwave heating type evaporator

    International Nuclear Information System (INIS)

    Taura, Masazumi; Nishi, Akio; Morimoto, Takashi; Izumi, Jun; Tamura, Kazuo; Morooka, Akihiko.

    1987-01-01

    Purpose: To prevent evaporization stills against corrosion due to radioactive liquid wastes. Constitution: Microwaves are supplied from a microwave generator by way of a wave guide tube and through a microwave permeation window to the inside of an evaporatization still. A matching device is attached to the wave guide tube for transmitting the microwaves in order to match the impedance. When the microwaves are supplied to the inside of the evaporization still, radioactive liquid wastes supplied from a liquid feed port by way of a spray tower to the inside of the evaporization still is heated and evaporated by the induction heating of the microwaves. (Seki, T.)

  15. Multiple scattering effects in 7Li

    International Nuclear Information System (INIS)

    Cox, A.J.; Warner, P.C.

    1985-01-01

    The differential cross-sections for the production of 0.478 MeV γ-rays following the inelastic scattering of 14 MeV neutrons in large samples of LiF, which will be used in fusion reactor blankets, have been measured. The neutrons were produced using the 3 H(d,n) 4 α reaction, with the deuterons being accelerated by a 150 kV SAMES type accelerator. In order to reduce the background level the γ-ray signal was gated, using a time of flight technique based on the α-particle associated with neutron production. Measurements of the γ-ray production differential cross-sections were made for various thicknesses of LiF. The results were compared to the predictions of the Monte Carlo Computer Code, MORSE, with an agreement of +-11% being achieved. In addition a phenomenological expression was found which is capable of predicting the variation in cross-sections with thickness due to multiple scattering effects to within +-12%. (author)

  16. Steady parallel flow in an evaporating fluid heated from sidewalls

    International Nuclear Information System (INIS)

    Das, Kausik S.

    2009-01-01

    Evaporation is ubiquitous in nature, but very few attempts have been made in the past to couple the effects of evaporation with fluid flow behavior. In this theoretical paper we have discussed the effects of evaporation on the dynamics of steady state thermocapillary convection in a two-dimensional rectangular container. The liquid is heated by differentially heated sidewalls and mass loss from the interface due to evaporation is compensated by the liquid entering into the container through a lower inlet, thus keeping the thickness of the liquid layer constant. We show that for an evaporating liquid one can obtain a plane parallel base state profile which depends on the evaporative mass flux.

  17. Effective capacity of multiple antenna channels: Correlation and keyhole

    KAUST Repository

    Zhong, Caijun; Ratnarajah, Tharm; Wong, Kaikit; Alouini, Mohamed-Slim

    2012-01-01

    In this study, the authors derive the effective capacity limits for multiple antenna channels which quantify the maximum achievable rate with consideration of link-layer delay-bound violation probability. Both correlated multiple-input single

  18. Response of bacteria in wastewater sludge to moisture loss by evaporation and effect of moisture content on bacterial inactivation by ionizing radiation

    International Nuclear Information System (INIS)

    Ward, R.L.; Yeager, J.G.; Ashley, C.S.

    1981-01-01

    Two studies were carried out to determine the influence of moisture content on the survival of bacteria in raw wastewater sludge. The first study involved the effect of water loss by evaporation on the bacterial population. The second used these dewatered samples to measure the effects of moisture content on the inactivation of bacteria in sludge by ionizing radiation. Both studies involved survival measurements of six representative fecally associated bacteria grown separately in sterilized sludge as well as survival data on bacteria indigenous to sludge. Growth of bacteria was stimulated in sludge during the initial phase of moisture removal by evaporation, but the reduction of moisture content below about 50% by weight caused a proportional decrease in bacterial numbers. The rates of inactivation of bacteria by ionizing radiation in sludge were usually modified to some degree by variations in moisture content. Most bacteria were found to be somewhat protected from ionizing radiation at reduced moisture levels

  19. Intrinsic Evaporative Cooling by Hygroscopic Earth Materials

    Directory of Open Access Journals (Sweden)

    Alexandra R. Rempel

    2016-08-01

    Full Text Available The phase change of water from liquid to vapor is one of the most energy-intensive physical processes in nature, giving it immense potential for cooling. Diverse evaporative cooling strategies have resulted worldwide, including roof ponds and sprinklers, courtyard fountains, wind catchers with qanats, irrigated green roofs, and fan-assisted evaporative coolers. These methods all require water in bulk liquid form. The evaporation of moisture that has been sorbed from the atmosphere by hygroscopic materials is equally energy-intensive, however, yet has not been examined for its cooling potential. In arid and semi-arid climates, hygroscopic earth buildings occur widely and are known to maintain comfortable indoor temperatures, but evaporation of moisture from their walls and roofs has been regarded as unimportant since water scarcity limits irrigation and rainfall; instead, their cool interiors are attributed to well-established mass effects in delaying the transmission of sensible gains. Here, we investigate the cooling accomplished by daily cycles of moisture sorption and evaporation which, requiring only ambient humidity, we designate as “intrinsic” evaporative cooling. Connecting recent soil science to heat and moisture transport studies in building materials, we use soils, adobe, cob, unfired earth bricks, rammed earth, and limestone to reveal the effects of numerous parameters (temperature and relative humidity, material orientation, thickness, moisture retention properties, vapor diffusion resistance, and liquid transport properties on the magnitude of intrinsic evaporative cooling and the stabilization of indoor relative humidity. We further synthesize these effects into concrete design guidance. Together, these results show that earth buildings in diverse climates have significant potential to cool themselves evaporatively through sorption of moisture from humid night air and evaporation during the following day’s heat. This finding

  20. Effect of surfactant concentration on characteristics of mesoporous bioactive glass prepared by evaporation induced self-assembly process

    International Nuclear Information System (INIS)

    Shih, Chi-Chung; Chien, Chi-Sheng; Kung, Jung-Chang; Chen, Jian-Chih; Chang, Shy-Shin; Lu, Pei-Shan; Shih, Chi-Jen

    2013-01-01

    Highlights: ► All the unwanted organic contents were removed completely at temperatures above 600 °C. ► Specific surface area and pore volume of Mesoporous bioactive glasses reached maximum at the critical surfactant concentration. ► SAED pattern suggests that some glassy structures in the Bioactive Glasses became crystalline due to the heat treatment. ► The MBGs can induce the formation of an apatite-like layer on their surface in SBF, even after short soaking periods. - Abstract: Mesoporous bioactive glasses were prepared by the evaporation-induced self-assembly method. The main objective of the present study is to determine the effect of surfactant concentration on the synthesis of SiO 2 –CaO–P 2 O 5 mesoporous bioactive glasses; the characterization techniques used include X-ray diffraction, scanning electron microscopy and nitrogen adsorption and desorption isotherms. The results show that the specific surface area initially increased with increasing surfactant concentrations in the range of 2.1–9.1 wt% and significantly decreased from 328.7 to 204.0 m 2 /g in the concentration range of 9.1–12.5 wt%. For texture evaluation, the selected area electron diffraction patterns of the mesoporous bioactive glass precursor gels (9.1 wt% F127) calcined at different temperatures were analyzed; these patterns support the notion that some glassy structures in bioactive glasses become crystalline following heat treatment. The scanning electron microscopy images and X-ray diffraction patterns obtained agree with the inductively coupled plasma with atomic emission spectroscopy results as the mesoporous bioactive glasses can induce the formation of an apatite-like layer on their surface in SBF, even after short soaking periods.

  1. Effect of surfactant concentration on characteristics of mesoporous bioactive glass prepared by evaporation induced self-assembly process

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Chi-Chung [Department of Emergency Medicine, Chang Gung Memorial Hospital, Keelung, and Chang Gung University College of Medicine, Taoyuan, Taiwan (China); Department of Family Medicine, Chang Gung Memorial Hospital, Keelung, and Chang Gung University College of Medicine, Taoyuan, Taiwan (China); Chien, Chi-Sheng [Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Department of Orthopaedics, Chi Mei Foundation Hospital, Tainan, Taiwan (China); Department of Electrical Engineering, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Kung, Jung-Chang [Department of Family Dentistry, Chung-Ho Memorial Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chen, Jian-Chih [Department of Orthopaedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Chang, Shy-Shin [Department of Emergency Medicine, Chang Gung Memorial Hospital, Taoyuan, and Chang Gung University College of Medicine, Taoyuan, Taiwan (China); Department of Family Medicine, Chang Gung Memorial Hospital, Taoyuan, and Chang Gung University College of Medicine, Taoyuan, Taiwan (China); Lu, Pei-Shan [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 80708, Taiwan (China); Shih, Chi-Jen, E-mail: cjshih@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 80708, Taiwan (China)

    2013-01-01

    Highlights: Black-Right-Pointing-Pointer All the unwanted organic contents were removed completely at temperatures above 600 Degree-Sign C. Black-Right-Pointing-Pointer Specific surface area and pore volume of Mesoporous bioactive glasses reached maximum at the critical surfactant concentration. Black-Right-Pointing-Pointer SAED pattern suggests that some glassy structures in the Bioactive Glasses became crystalline due to the heat treatment. Black-Right-Pointing-Pointer The MBGs can induce the formation of an apatite-like layer on their surface in SBF, even after short soaking periods. - Abstract: Mesoporous bioactive glasses were prepared by the evaporation-induced self-assembly method. The main objective of the present study is to determine the effect of surfactant concentration on the synthesis of SiO{sub 2}-CaO-P{sub 2}O{sub 5} mesoporous bioactive glasses; the characterization techniques used include X-ray diffraction, scanning electron microscopy and nitrogen adsorption and desorption isotherms. The results show that the specific surface area initially increased with increasing surfactant concentrations in the range of 2.1-9.1 wt% and significantly decreased from 328.7 to 204.0 m{sup 2}/g in the concentration range of 9.1-12.5 wt%. For texture evaluation, the selected area electron diffraction patterns of the mesoporous bioactive glass precursor gels (9.1 wt% F127) calcined at different temperatures were analyzed; these patterns support the notion that some glassy structures in bioactive glasses become crystalline following heat treatment. The scanning electron microscopy images and X-ray diffraction patterns obtained agree with the inductively coupled plasma with atomic emission spectroscopy results as the mesoporous bioactive glasses can induce the formation of an apatite-like layer on their surface in SBF, even after short soaking periods.

  2. Substrate bias effect on crystallinity of polycrystalline silicon thin films prepared by pulsed ion-beam evaporation method

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Fazlat; Gunji, Michiharu; Yang, Sung-Chae; Suzuki, Tsuneo; Suematsu, Hisayuki; Jiang, Weihua; Yatsui, Kiyoshi [Nagaoka Univ. of Technology, Extreme Energy-Density Research Inst., Nagaoka, Niigata (Japan)

    2002-06-01

    The deposition of polycrystalline silicon thin films has been tried by a pulsed ion-beam evaporation method, where high crystallinity and deposition rate have been achieved without heating the substrate. The crystallinity and the deposition rate were improved by applying bias voltage to the substrate, where instantaneous substrate heating might have occurred by ion-bombardment. (author)

  3. Substrate bias effect on crystallinity of polycrystalline silicon thin films prepared by pulsed ion-beam evaporation method

    International Nuclear Information System (INIS)

    Ali, Fazlat; Gunji, Michiharu; Yang, Sung-Chae; Suzuki, Tsuneo; Suematsu, Hisayuki; Jiang, Weihua; Yatsui, Kiyoshi

    2002-01-01

    The deposition of polycrystalline silicon thin films has been tried by a pulsed ion-beam evaporation method, where high crystallinity and deposition rate have been achieved without heating the substrate. The crystallinity and the deposition rate were improved by applying bias voltage to the substrate, where instantaneous substrate heating might have occurred by ion-bombardment. (author)

  4. Phase Behavior and Evaporation Profile of Tween 20 - Eugenol System. Effect of Different Alkane Chain Length and Solvent System

    International Nuclear Information System (INIS)

    Kassim, A.; Lim, W.H.; Kuangl, D.; Rusmawati, W.W.M.; Abdullah, A.H.; Teoh, S.P.

    2003-01-01

    The isotropic region of Tween 20/eugenol/n-alkane in aqueous systems was determined. The solubilisation trend of isotropic solution formed in the presence of eugenol was studied as a function of different alkyl chain length of n-alkane. The solubility of solvent in surfactant solution is dependent on their molecular polarity. An increase in n-alkane chain length (lower polarity) lead to smaller isotropic region which will affect the surfactant partitioning between the interface, the oil phase and the aqueous phase of the microemulsion as the oil chain length is varied. The changes of evaporation behaviour were affected strongly by the types of phases existed in the systems. The increment of n-alkane and water content led to higher evaporation rate. But the formation of w/o microemulsion would lower the evaporation rate because water molecules were trapped in the core of aggregates. In solubilisation system, evaporation rate is dependent on the solvent content and the interaction between Tween 20 and solvent molecules in the mixed composition. (author)

  5. Effect of Deposition Rate on Structure and Surface Morphology of Thin Evaporated Al Films on Dielectrics and Semiconductors

    DEFF Research Database (Denmark)

    Bordo, K.; Rubahn, H. G.

    2012-01-01

    Aluminum (Al) films with thickness of 100 nm were grown on unheated glass, silicon and mica substrates by electron beam evaporation. The deposition rates were adjusted in the range between 0.1 nm/s and 2 nm/s, the pressure in the vacuum chamber during deposition was lower than 1.10(-3) Pa. The st...

  6. Effect of multiple scattering on lidar measurements

    International Nuclear Information System (INIS)

    Cohen, A.

    1977-01-01

    The lidar equation in its standard form involves the assumption that the scattered irradiance reaching the lidar receiver has been only singly scattered. However, in the cases of scattering from clouds and thick aerosol layers, it is shown that multiple scattering cannot be neglected. An experimental method for the detection of multiple scattering by depolarization measurement techniques is discussed. One method of theoretical calculations of double-scattering is presented and discussed

  7. Spiral multiple-effect diffusion solar still coupled with vacuum-tube collector and heat pipe

    KAUST Repository

    Huang, Bin-Juine

    2015-04-01

    © 2015 Elsevier B.V. A novel solar still with spiral-shape multiple-effect diffusion unit is developed in the present study. The test results of a 14-effect unit coupled with vacuum-tube solar collector (absorber area 1.08m2) show that the highest daily pure water production is 40.6kgd-1. The measured highest productivity based on the area of glass cover, solar absorber, and evaporating surface is 34.7, 40.6, and 7.96kgm-2d-1, respectively, which are much higher than the published results. The measured solar distillation efficiency is 2.0-3.5. The performance enhancement results mainly from the lateral diffusion process in the spiraled still cell. The vapor flow generated by heat input can flow freely and laterally through the spiral channel down to the end when solar heat input is high. Besides, the larger evaporating and condensing area at the outer cell may increase heat and mass transfer at the outer cell.

  8. A Ghost Fluid/Level Set Method for boiling flows and liquid evaporation: Application to the Leidenfrost effect

    International Nuclear Information System (INIS)

    Rueda Villegas, Lucia; Alis, Romain; Lepilliez, Mathieu; Tanguy, Sébastien

    2016-01-01

    The development of numerical methods for the direct numerical simulation of two-phase flows with phase change, in the framework of interface capturing or interface tracking methods, is the main topic of this study. We propose a novel numerical method, which allows dealing with both evaporation and boiling at the interface between a liquid and a gas. Indeed, in some specific situations involving very heterogeneous thermodynamic conditions at the interface, the distinction between boiling and evaporation is not always possible. For instance, it can occur for a Leidenfrost droplet; a water drop levitating above a hot plate whose temperature is much higher than the boiling temperature. In this case, boiling occurs in the film of saturated vapor which is entrapped between the bottom of the drop and the plate, whereas the top of the water droplet evaporates in contact of ambient air. The situation can also be ambiguous for a superheated droplet or at the contact line between a liquid and a hot wall whose temperature is higher than the saturation temperature of the liquid. In these situations, the interface temperature can locally reach the saturation temperature (boiling point), for instance near a contact line, and be cooler in other places. Thus, boiling and evaporation can occur simultaneously on different regions of the same liquid interface or occur successively at different times of the history of an evaporating droplet. Standard numerical methods are not able to perform computations in these transient regimes, therefore, we propose in this paper a novel numerical method to achieve this challenging task. Finally, we present several accuracy validations against theoretical solutions and experimental results to strengthen the relevance of this new method.

  9. Evaporation, Boiling and Bubbles

    Science.gov (United States)

    Goodwin, Alan

    2012-01-01

    Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

  10. Effects of carbonyl bond, metal cluster dissociation, and evaporation rates on predictions of nanotube production in high-pressure carbon monoxide

    Science.gov (United States)

    Scott, Carl D.; Smalley, Richard E.

    2003-01-01

    The high-pressure carbon monoxide (HiPco) process for producing single-wall carbon nanotubes (SWNTs) uses iron pentacarbonyl as the source of iron for catalyzing the Boudouard reaction. Attempts using nickel tetracarbonyl led to no production of SWNTs. This paper discusses simulations at a constant condition of 1300 K and 30 atm in which the chemical rate equations are solved for different reaction schemes. A lumped cluster model is developed to limit the number of species in the models, yet it includes fairly large clusters. Reaction rate coefficients in these schemes are based on bond energies of iron and nickel species and on estimates of chemical rates for formation of SWNTs. SWNT growth is measured by the conformation of CO2. It is shown that the production of CO2 is significantly greater for FeCO because of its lower bond energy as compared with that of NiCO. It is also shown that the dissociation and evaporation rates of atoms from small metal clusters have a significant effect on CO2 production. A high rate of evaporation leads to a smaller number of metal clusters available to catalyze the Boudouard reaction. This suggests that if CO reacts with metal clusters and removes atoms from them by forming MeCO, this has the effect of enhancing the evaporation rate and reducing SWNT production. The study also investigates some other reactions in the model that have a less dramatic influence.

  11. Analysis of the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged heavy duty diesel power generator for marine applications

    International Nuclear Information System (INIS)

    Michos, Constantine N.; Lion, Simone; Vlaskos, Ioannis; Taccani, Rodolfo

    2017-01-01

    Highlights: • Waste heat recovery on internal combustion engines is studied. • The backpressure effect of the Organic Rankine Cycle boiler has been evaluated. • Three different state-of-the art turbocharging technologies have been assessed. • Six different fluids for medium-high temperature recovery have been considered. • A reduction up to 10% in fuel consumption can be achieved. - Abstract: In marine and power generation sectors, waste heat recovery technologies are attracting growing attention in order to increase heavy duty diesel engines efficiency and decrease fuel consumption, with the purpose of respecting stringent emissions legislations. In this work, the backpressure effect of an Organic Rankine Cycle (ORC) evaporator on the exhaust line of a turbocharged, V12 heavy duty diesel engine, for typical marine and power generation applications has been investigated using the commercial software Ricardo WAVE. Three different state-of-the art turbocharging strategies are assessed in order to counterbalance the increased pumping losses of the engine due to the boiler installation: fixed turbine, Waste-Gate (WG) and Variable Geometry Turbine (VGT). At the same time, the steady-state thermodynamic performance of two different ORC configurations, simple tail-pipe evaporator and recuperated simple tail-pipe evaporator layouts, are assessed, with the scope of further increasing the engine power output, recovering unutilized exhaust gas heat. Several different working fluids, suitable for medium-high temperature waste heat recovery, are evaluated and screened, considering, as well, health and safety issues. Thermodynamic cycle parameters such as, for example, evaporation and condensing pressures, working fluid mass flow and cycle temperatures, are optimized in order to obtain the maximum improvement in Brake Specific Fuel Consumption (bsfc). From the engine side point of view, a VGT turbocharger is the most favorable solution to withstand increased

  12. (ajst) additive main effects and multiplicative

    African Journals Online (AJOL)

    2013-08-02

    Aug 2, 2013 ... genotypes assessed by biplot analysis showed that the most stable ... biplot is a useful tool for the analysis of multi-environment trial (MET) data. ... multiplicative components, extracting first the additive ... The AMMI analysis of variance of cassava harvest index of the 8 .... wheat mega-environments in Iran.

  13. Effect of ambient hydrogen sulfide on the physical properties of vacuum evaporated thin films of zinc sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Beer Pal [Department of Physics, C.C.S. University, Meerut 250004 (India)], E-mail: drbeerpal@gmail.com; Singh, Virendra [Forensic Science Laboratory, Malviya Nagar, New Delhi 110017 (India); Tyagi, R.C.; Sharma, T.P. [Department of Physics, C.C.S. University, Meerut 250004 (India)

    2008-02-15

    Evaporated thin films of zinc sulfide (ZnS) have been deposited in a low ambient atmosphere of hydrogen sulfide (H{sub 2}S {approx}10{sup -4} Torr). The H{sub 2}S atmosphere was obtained by a controlled thermal decomposition of thiourea [CS(NH{sub 2}){sub 2}] inside the vacuum chamber. It has been observed that at elevated substrates temperature of about 200 deg. C helps eject any sulfur atoms deposited due to thermal decomposition of ZnS during evaporation. The zinc ions promptly recombine with H{sub 2}S to give better stoichiometry of the deposited films. Optical spectroscopy, X-ray diffraction patterns and scanning electron micrographs depict the better crystallites and uniformity of films deposited by this technique. These deposited films were found to be more adherent to the substrates and are pinhole free, which is a very vital factor in device fabrication.

  14. Coupling effect between film boiling heat transfer and evaporation drag around a hot-particle in cold liquid

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Yan; YANG Yan-Hua; XU Ji-Jun

    2003-01-01

    Extremely rapid evaporation could occur when high-temperature particles contact withlow-temperature liquid. This kind of phenomenon is associated with the engineering safety and the problems inhigh-transient multi-phase fluid and heat transfer. The aim of our study was to design and build an observable ex-periment facility. The first series of experiments were performed by pouring one or six high-temperature particles intoa low saturated temperature liquid pool. The particle's falling-down speed was recorded by a high-speed camera, thuswe can find the special resistant feature of the moving high-temperature particles, which is induced by the high-speedevaporation surrounding the particles. The study has experimentally verified the theory of evaporation drag model.

  15. The Effects of Film Thickness and Evaporation Rate on Si-Cu Thin Films for Lithium Ion Batteries.

    Science.gov (United States)

    Polat, B Deniz; Keles, Ozgul

    2015-12-01

    The reversible cyclability of Si based composite anodes is greatly improved by optimizing the atomic ratio of Si/Cu, the thickness and the evaporation rates of films fabricated by electron beam deposition method. The galvanostatic test results show that 500 nm thick flim, having 10%at. Cu-90%at. Si, deposited with a moderate evaporation rate (10 and 0.9 Å/s for Si and Cu respectively) delivers 2642.37 mAh g(-1) as the first discharge capacity with 76% Coulombic efficiency. 99% of its initial capacity is retained after 20 cycles. The electron conductive pathway and high mechanical tolerance induced by Cu atoms, the low electrical resistivity of the film due to Cu3Si particles, and the homogeneously distributed nano-sized/amorphous particles in the composite thin film could explain this outstanding electrochemical performance of the anode.

  16. Evaporation rate of nucleating clusters.

    Science.gov (United States)

    Zapadinsky, Evgeni

    2011-11-21

    The Becker-Döring kinetic scheme is the most frequently used approach to vapor liquid nucleation. In the present study it has been extended so that master equations for all cluster configurations are included into consideration. In the Becker-Döring kinetic scheme the nucleation rate is calculated through comparison of the balanced steady state and unbalanced steady state solutions of the set of kinetic equations. It is usually assumed that the balanced steady state produces equilibrium cluster distribution, and the evaporation rates are identical in the balanced and unbalanced steady state cases. In the present study we have shown that the evaporation rates are not identical in the equilibrium and unbalanced steady state cases. The evaporation rate depends on the number of clusters at the limit of the cluster definition. We have shown that the ratio of the number of n-clusters at the limit of the cluster definition to the total number of n-clusters is different in equilibrium and unbalanced steady state cases. This causes difference in evaporation rates for these cases and results in a correction factor to the nucleation rate. According to rough estimation it is 10(-1) by the order of magnitude and can be lower if carrier gas effectively equilibrates the clusters. The developed approach allows one to refine the correction factor with Monte Carlo and molecular dynamic simulations.

  17. Modelling refrigerant distribution in microchannel evaporators

    DEFF Research Database (Denmark)

    Brix, Wiebke; Kærn, Martin Ryhl; Elmegaard, Brian

    2009-01-01

    of the refrigerant distribution is carried out for two channels in parallel and for two different cases. In the first case maldistribution of the inlet quality into the channels is considered, and in the second case a non-uniform airflow on the secondary side is considered. In both cases the total mixed superheat...... out of the evaporator is kept constant. It is shown that the cooling capacity of the evaporator is reduced significantly, both in the case of unevenly distributed inlet quality and for the case of non-uniform airflow on the outside of the channels.......The effects of refrigerant maldistribution in parallel evaporator channels on the heat exchanger performance are investigated numerically. For this purpose a 1D steady state model of refrigerant R134a evaporating in a microchannel tube is built and validated against other evaporator models. A study...

  18. Vacuum evaporation of pure metals

    OpenAIRE

    Safarian, Jafar; Engh, Thorvald Abel

    2013-01-01

    Theories on the evaporation of pure substances are reviewed and applied to study vacuum evaporation of pure metals. It is shown that there is good agreement between different theories for weak evaporation, whereas there are differences under intensive evaporation conditions. For weak evaporation, the evaporation coefficient in Hertz-Knudsen equation is 1.66. Vapor velocity as a function of the pressure is calculated applying several theories. If a condensing surface is less than one collision...

  19. Evaporation in hydrology and meteorology

    OpenAIRE

    Brandsma, T.

    1990-01-01

    In this paper the role of evaporation in hydrology and meteorology is discussed, with the emphasis on hydrology. The basic theory of evaporation is given and methods to determine evaporation are presented. Some applications of evaporation studies in literature are given in order to illustrate the theory. Further, special conditions in evaporation are considered, followed by a fotmulation of the difficulties in determining evaporation, The last part of the paper gives a short discussion about ...

  20. Advanced evaporator technology progress report FY 1992

    Energy Technology Data Exchange (ETDEWEB)

    Chamberlain, D.; Hutter, J.C.; Leonard, R.A. [and others

    1995-01-01

    This report summarizes the work that was completed in FY 1992 on the program {open_quotes}Technology Development for Concentrating Process Streams.{close_quotes} The purpose of this program is to evaluate and develop evaporator technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process. Concentrating these streams and minimizing the volume of waste generated can significantly reduce disposal costs; however, equipment to concentrate the streams and recycle the decontaminated condensates must be installed. LICON, Inc., is developing an evaporator that shows a great deal of potential for this application. In this report, concepts that need to be incorporated into the design of an evaporator operated in a radioactive environment are discussed. These concepts include criticality safety, remote operation and maintenance, and materials of construction. Both solubility and vapor-liquid equilibrium data are needed to design an effective process for concentrating process streams. Therefore, literature surveys were completed and are summarized in this report. A model that is being developed to predict vapor phase compositions is described. A laboratory-scale evaporator was purchased and installed to study the evaporation process and to collect additional data. This unit is described in detail. Two new LICON evaporators are being designed for installation at Argonne-East in FY 1993 to process low-level radioactive waste generated throughout the laboratory. They will also provide operating data from a full-sized evaporator processing radioactive solutions. Details on these evaporators are included in this report.

  1. Advanced evaporator technology progress report FY 1992

    International Nuclear Information System (INIS)

    Chamberlain, D.; Hutter, J.C.; Leonard, R.A.

    1995-01-01

    This report summarizes the work that was completed in FY 1992 on the program open-quotes Technology Development for Concentrating Process Streams.close quotes The purpose of this program is to evaluate and develop evaporator technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process. Concentrating these streams and minimizing the volume of waste generated can significantly reduce disposal costs; however, equipment to concentrate the streams and recycle the decontaminated condensates must be installed. LICON, Inc., is developing an evaporator that shows a great deal of potential for this application. In this report, concepts that need to be incorporated into the design of an evaporator operated in a radioactive environment are discussed. These concepts include criticality safety, remote operation and maintenance, and materials of construction. Both solubility and vapor-liquid equilibrium data are needed to design an effective process for concentrating process streams. Therefore, literature surveys were completed and are summarized in this report. A model that is being developed to predict vapor phase compositions is described. A laboratory-scale evaporator was purchased and installed to study the evaporation process and to collect additional data. This unit is described in detail. Two new LICON evaporators are being designed for installation at Argonne-East in FY 1993 to process low-level radioactive waste generated throughout the laboratory. They will also provide operating data from a full-sized evaporator processing radioactive solutions. Details on these evaporators are included in this report

  2. Evaporation under vacuum condition

    International Nuclear Information System (INIS)

    Mizuta, Satoshi; Shibata, Yuki; Yuki, Kazuhisa; Hashizume, Hidetoshi; Toda, Saburo; Takase, Kazuyuki; Akimoto, Hajime

    2000-01-01

    In nuclear fusion reactor design, an event of water coolant ingress into its vacuum vessel is now being considered as one of the most probable accidents. In this report, the evaporation under vacuum condition is evaluated by using the evaporation model we have developed. The results show that shock-wave by the evaporation occurs whose behavior strongly depends on the initial conditions of vacuum. And in the case of lower initial pressure and temperature, the surface temp finally becomes higher than other conditions. (author)

  3. Effects of near surface soil moisture profiles during evaporation on far-field ground-penetrating radar data: A numerical study

    KAUST Repository

    Moghadas, Davood

    2013-01-01

    We theoretically investigated the effect of vapor flow on the drying front that develops in soils when water evaporates from the soil surface and on GPR data. The results suggest the integration of the full-wave GPR model with a coupled water, vapor, and heat flow model to accurately estimate the soil hydraulic properties. We investigated the Effects of a drying front that emerges below an evaporating soil surface on the far-field ground-penetrating radar (GPR) data. First, we performed an analysis of the width of the drying front in soils with 12 different textures by using an analytical model. Then, we numerically simulated vertical soil moisture profiles that develop during evaporation for the soil textures. We performed the simulations using a Richards flow model that considers only liquid water flow and a model that considers coupled water, vapor, and heat flows. The GPR signals were then generated from the simulated soil water content profiles taking into account the frequency dependency of apparent electrical conductivity and dielectric permittivity. The analytical approach indicated that the width of the drying front at the end of Stage I of the evaporation was larger in silty soils than in other soil textures and smaller in sandy soils. We also demonstrated that the analytical estimate of the width of the drying front can be considered as a proxy for the impact that a drying front could have on far-field GPR data. The numerical simulations led to the conclusion that vapor transport in soil resulted in S-shaped soil moisture profiles, which clearly influenced the GPR data. As a result, vapor flow needs to be considered when GPR data are interpreted in a coupled inversion approach. Moreover, the impact of vapor flow on the GPR data was larger for silty than for sandy soils. These Effects on the GPR data provide promising perspectives regarding the use of radars for evaporation monitoring. © Soil Science Society of America 5585 Guilford Rd., Madison, WI

  4. Vapor-based interferometric measurement of local evaporation rate and interfacial temperature of evaporating droplets.

    Science.gov (United States)

    Dehaeck, Sam; Rednikov, Alexey; Colinet, Pierre

    2014-03-04

    The local evaporation rate and interfacial temperature are two quintessential characteristics for the study of evaporating droplets. Here, it is shown how one can extract these quantities by measuring the vapor concentration field around the droplet with digital holographic interferometry. As a concrete example, an evaporating freely receding pending droplet of 3M Novec HFE-7000 is analyzed at ambient conditions. The measured vapor cloud is shown to deviate significantly from a pure-diffusion regime calculation, but it compares favorably to a new boundary-layer theory accounting for a buoyancy-induced convection in the gas and the influence upon it of a thermal Marangoni flow. By integration of the measured local evaporation rate over the interface, the global evaporation rate is obtained and validated by a side-view measurement of the droplet shape. Advective effects are found to boost the global evaporation rate by a factor of 4 as compared to the diffusion-limited theory.

  5. Data-driven analysis of the effectiveness of evaporative emissions control systems of passenger cars in real world use condition: Time and spatial mapping

    Science.gov (United States)

    De Gennaro, Michele; Paffumi, Elena; Martini, Giorgio

    2016-03-01

    This paper assesses the effectiveness of the evaporative emissions control systems of European passenger cars on the basis of real-world activity data. The study relies on two large datasets of driving patterns from conventional fuel vehicles collected by means of on-board GPS systems, consisting of 4.5 million trips and parking events recorded by monitoring 28,000 vehicles over one month. Real world evaporative emissions are estimated using a model that associates a carbon canister desorption event to each trip and a fuel vapour generation event to each parking. The mass of volatile organic compounds released into the air is calculated taking into account the hot-soak, permeation and breathing emission mechanisms. The analysis is based on 36 scenarios, defined by varying the climate conditions, the fuel vapour pressure, the tank material, the tank headspace volume, the purging volume flow rate and the mass of the activated carbon contained in the canister. The results show that in May 4 out of the 18 scenarios considered for Modena and 6 out of the 18 scenarios considered for Firenze lead to evaporative emissions values above the current type approval limit (i.e. 2 [g/day] per vehicle). In July, these numbers increase to 10 out of the 18 scenarios for Modena and to 12 out of the 18 scenarios for Firenze. Looking at the fleet distribution a share of approximately 20% of the fleet is characterised by evaporative emissions higher than the limit in May, increasing to 48% in July, with a peak value of 98%. The emission peak value is estimated to be approximately 4 [g/day] in May and 8 [g/day] in July, while the time-dependent results show emission rates up to nearly 15 [g/s] in Modena and 30 [g/s] in Firenze, with a respective cumulative value in July up to 0.4 and 0.8 tons of VOCs per day. The space-dependent results show a value of the emissions in July of approximately 4-to-8 [kg/km2/day] in the city areas. These results confirm previous findings from the authors

  6. CAPSULE REPORT: EVAPORATION PROCESS

    Science.gov (United States)

    Evaporation has been an established technology in the metal finishing industry for many years. In this process, wastewaters containing reusable materials, such as copper, nickel, or chromium compounds are heated, producing a water vapor that is continuously removed and condensed....

  7. On the link between potential evaporation and regional evaporation from a CBL perspective

    Science.gov (United States)

    Lhomme, J. P.; Guilioni, L.

    2010-07-01

    The relationship between potential evaporation and actual evaporation was first examined by Bouchet (Proc Berkeley Calif Symp IAHS Publ, 62:134-142, 1963) who considered potential evaporation as the consequence of regional evaporation due to atmospheric feedbacks. Using a heuristic approach, he derived a complementary relationship which, despite no real theoretical background, has proven to be very useful in interpreting many experimental data under various climatic conditions. Here, the relationship between actual and potential evaporation is reinterpreted in the context of the development of the convective boundary layer (CBL): first, with a closed-box approach, where the CBL has an impermeable lid; and then with an open system, where air is exchanged between the CBL and its external environment. By applying steady forcing to these systems, it is shown that an equilibrium state is reached, where potential evaporation has a specific equilibrium formulation as a function of two parameters: one representing large-scale advection and the other the feedback effect of regional evaporation on potential evaporation, i.e. a kind of “medium-scale advection”. It is also shown that the original form of Bouchet’s complementary relationship is not verified in the equilibrium state. This analysis leads us to propose a new and more rational approach of the relationship between potential and actual evaporation through the effective surface resistance of the region.

  8. Enhanced Evaporation and Condensation in Tubes

    Science.gov (United States)

    Honda, Hiroshi

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

  9. Boilers, evaporators, and condensers

    International Nuclear Information System (INIS)

    Kakac, S.

    1991-01-01

    This book reports on the boilers, evaporators and condensers that are used in power plants including nuclear power plants. Topics included are forced convection for single-phase side heat exchangers, heat exchanger fouling, industrial heat exchanger design, fossil-fuel-fired boilers, once through boilers, thermodynamic designs of fossil fuel-first boilers, evaporators and condensers in refrigeration and air conditioning systems (with respect to reducing CFC's) and nuclear steam generators

  10. Hemifield effects in multiple identity tracking.

    Directory of Open Access Journals (Sweden)

    Charlotte Hudson

    Full Text Available In everyday life, we often need to attentively track moving objects. A previous study has claimed that this tracking occurs independently in the left and right visual hemifields (Alvarez & Cavanagh, 2005, Psychological Science,16, 637-647. Specifically, it was shown that observers were much more accurate at tracking objects that were spread over both visual hemifields as opposed to when all were confined to a single visual hemifield. In that study, observers were not required to remember the identities of the objects. Conversely, in real life, there is seldom any benefit to tracking an object unless you can also recall its identity. It has been predicted that when observers are required to remember the identities of the tracked objects a bilateral advantage should no longer be observed (Oksama & Hyönä, 2008, Cognitive Psychology, 56, 237-283. We tested this prediction and found that a bilateral advantage still occurred, though it was not as strong as when observers were not required to remember the identities of the targets. Even in the later case we found that tracking was not completely independent in the two visual hemifields. We present a combined model of multiple object tracking and multiple identity tracking that can explain our data.

  11. Waste Heat Recovery and Recycling in Thermal Separation Processes: Distillation, Multi-Effect Evaporation (MEE) and Crystallization Processes

    Energy Technology Data Exchange (ETDEWEB)

    Emmanuel A. Dada; Chandrakant B. Panchal; Luke K. Achenie; Aaron Reichl; Chris C. Thomas

    2012-12-03

    Evaporation and crystallization are key thermal separation processes for concentrating and purifying inorganic and organic products with energy consumption over 1,000 trillion Btu/yr. This project focused on a challenging task of recovering low-temperature latent heat that can have a paradigm shift in the way thermal process units will be designed and operated to achieve high-energy efficiency and significantly reduce the carbon footprint as well as water footprint. Moreover, this project has evaluated the technical merits of waste-heat powered thermal heat pumps for recovery of latent heat from distillation, multi-effect evaporation (MEE), and crystallization processes and recycling into the process. The Project Team has estimated the potential energy, economics and environmental benefits with the focus on reduction in CO2 emissions that can be realized by 2020, assuming successful development and commercialization of the technology being developed. Specifically, with aggressive industry-wide applications of heat recovery and recycling with absorption heat pumps, energy savings of about 26.7 trillion Btu/yr have been estimated for distillation process. The direct environmental benefits of this project are the reduced emissions of combustible products. The estimated major reduction in environmental pollutants in the distillation processes is in CO2 emission equivalent to 3.5 billion lbs/year. Energy consumption associated with water supply and treatments can vary between 1,900 kWh and 23,700 kWh per million-gallon water depending on sources of natural waters [US DOE, 2006]. Successful implementation of this technology would significantly reduce the demand for cooling-tower waters, and thereby the use and discharge of water treatment chemicals. The Project Team has also identified and characterized working fluid pairs for the moderate-temperature heat pump. For an MEE process, the two promising fluids are LiNO3+KNO3+NANO3 (53:28:19 ) and LiNO3+KNO3+NANO2

  12. Clustered field evaporation of metallic glasses in atom probe tomography

    International Nuclear Information System (INIS)

    Zemp, J.; Gerstl, S.S.A.; Löffler, J.F.; Schönfeld, B.

    2016-01-01

    Field evaporation of metallic glasses is a stochastic process combined with spatially and temporally correlated events, which are referred to as clustered evaporation (CE). This phenomenon is investigated by studying the distance between consecutive detector hits. CE is found to be a strongly localized phenomenon (up to 3 nm in range) which also depends on the type of evaporating ions. While a similar effect in crystals is attributed to the evaporation of crystalline layers, CE of metallic glasses presumably has a different – as yet unknown – physical origin. The present work provides new perspectives on quantification methods for atom probe tomography of metallic glasses. - Highlights: • Field evaporation of metallic glasses is heterogeneous on a scale of up to 3 nm. • Amount of clustered evaporation depends on ion species and temperature. • Length scales of clustered evaporation and correlative evaporation are similar.

  13. Advanced multi-evaporator loop thermosyphon

    International Nuclear Information System (INIS)

    Mameli, M.; Mangini, D.; Vanoli, G.F.T.; Araneo, L.; Filippeschi, S.; Marengo, M.

    2016-01-01

    A novel prototype of multi-evaporator closed loop thermosyphon is designed and tested at different heaters position, inclinations and heat input levels, in order to prove that a peculiar arrangement of multiple heaters may be used in order to enhance the flow motion and consequently the thermal performance. The device consists in an aluminum tube (Inner/Outer tube diameter 3.0 mm/5.0 mm), bent into a planar serpentine with five U-turns and partially filled with FC-72, 50% vol. The evaporator zone is equipped with five heated patches (one for each U-turn) in series with respect to the flow path. In the first arrangement, heaters are wrapped on each bend symmetrically, while in the second layout heaters are located on the branch just above the U-turn, non-symmetrical with respect to the gravity direction, in order to promote the fluid circulation in a preferential direction. The condenser zone is cooled by forced air and equipped with a 50 mm transparent section for the flow pattern visualization. The non-symmetrical heater arrangement effectively promotes a stable fluid circulation and a reliable operation for a wider range of heat input levels and orientations with respect to the symmetrical case. In vertical position, the heat flux dissipation exceeds the pool boiling heat transfer limit for FC-72 by 75% and the tube wall temperatures in the evaporator zone are kept lower than 80 °C. Furthermore, the heat flux capability is up to five times larger with respect to the other existing wickless heat pipe technologies demonstrating the attractiveness of the new concept for electronic cooling thermal management. - Highlights: • A novel passive heat transfer device named Multi-Evaporator Loop Thermosyphon is tested. • The loop is investigated at different heating patterns, inclinations and heat power levels. • The non-symmetrical heating configuration promotes the fluid circulation within the loop. • The performance in terms of maximum heat flux exceeds the

  14. Heat transfer property of refrigerant-oil mixture in a flooded evaporator: The role of bubble formation and oil retention

    International Nuclear Information System (INIS)

    Koo, Kyoung-Min; Kim, Sung-Gyu; Jeong, Young-Man; Lee, Jae-Keun; Kim, Soo Hyung; Lee, Soowon; Park, Nae-Hyun; Na, Byung-Chul; Hwang, Yoon-Jae; Kim, Byung-Soon; Hwang, Joon-Hyun

    2013-01-01

    We examined the effect of oil retention on the heat transfer performance of a shell-and-tube-type evaporator which had 26 inner tubes and was filled with the refrigerant R-134a. The refrigerant was boiled on the surface of the inner tubes in the evaporator, while chilled water circulated through these tubes. An experimental apparatus was designed to measure both the pressure and temperature profiles at the inlet and outlet of the flooded evaporator. Four windows were installed for observing the operation of the flooded evaporator. A series of experiments were carried out under the following conditions: the refrigerant saturation temperature, 5 .deg. C; refrigerant inlet quality, 0.1; heat fluxes from water to the refrigerant, 5-7 kW/m"2.. The concentration of the oil retained in the refrigerant was then varied up to approximately 10% to observe the effect on the heat transfer performance of the flooded evaporator. Increasing the oil content (i.e., increasing the concentration up to a maximum of approximately 10%) in the refrigerant R134a did not lead to any appreciable reduction in the overall heat transfer coefficient of a flooded evaporator with multiple-inner-tubes. When the oil concentration in the refrigerant was approximately 10%, the heat transfer degradation in the case of the flooded evaporator with multiple-inner-tubes was approximately 11%, which was found to be much smaller than the heat transfer degradation in the case of a flooded evaporator with a single-tube (26-49%). This observation suggested that the oil retained in the refrigerant did not significantly deteriorate the heat transfer performance of the flooded evaporator, presumably because the presence of tube bundles promoted forced convection by agitating bubbles

  15. Observed and modeled multi-year evaporation from three field-scale experiments using water balance and Penman-Monteith methods: Profound effect of material type and wind exposure

    Science.gov (United States)

    Peterson, H. E.; Fretz, N.; Bay, D.; Mayer, K. U.; Smith, L.; Beckie, R. D.

    2013-12-01

    Three instrumented experimental waste-rock piles at the Cu-Zn-Mo Antamina Mine in Peru are composed of distinct types of waste rock but are otherwise almost identical in size and geometry and experience the same atmospheric conditions with the exception of wind exposure. Evaporation from the piles was calculated using the water balance method over three- and four-year periods to determine the effect of material type and meteorological variability on evaporation. Annual changes in water storage were low or negligible except as a result of unusually high annual precipitation. Observed evaporation was high (44% - 75% of precipitation) and was extremely variable annually in the coarsest-grained waste-rock pile 1, most likely as a result of greater wind exposure and air circulation in that pile. Observed evaporation was moderate (36% - 48% of precipitation) with moderate annual variability in the finer-grained, relatively homogeneous waste-rock pile 2. Observed evaporation was low (24% - 32% of precipitation) with low annual variability in the finer-grained, relatively heterogeneous waste-rock pile 3, most likely as a result of low air circulation coupled with complex flow regimes that include high-velocity preferential flow paths. Slightly higher evaporation was observed on the slopes than on the crowns of Pile 2, while much lower evaporation was observed on the slopes than on the crowns of Piles 1 and 3. Evidence suggests that Piles 1 and 3 slope water-balance evaporation estimates are skewed by non-vertical flow and that, in general, evaporation is higher on the slopes than on the crowns of the piles. Evaporation was also estimated using the Food and Agriculture Organization of the United Nations modified Penman-Monteith method (FAO-PM; Allen et al., 1998) using base-case laboratory- and software- derived parameters. The base-case method underestimated observed evaporation calculated by the water balance method for Pile 1, overestimated observed evaporation for Pile

  16. Evaporation of nanofluid droplet on heated surface

    Directory of Open Access Journals (Sweden)

    Yeung Chan Kim

    2015-04-01

    Full Text Available In this study, an experiment on the evaporation of nanofluid sessile droplet on a heated surface was conducted. A nanofluid of 0.5% volumetric concentration mixed with 80-nm-sized CuO powder and pure water were used for experiment. Droplet was applied to the heated surface, and images of the evaporation process were obtained. The recorded images were analyzed to find the volume, diameter, and contact angle of the droplet. In addition, the evaporative heat transfer coefficient was calculated from experimental result. The results of this study are summarized as follows: the base diameter of the droplet was maintained stably during the evaporation. The measured temperature of the droplet was increased rapidly for a very short time, then maintained constantly. The nanofluid droplet was evaporated faster than the pure water droplet under the experimental conditions of the same initial volume and temperature, and the average evaporative heat transfer coefficient of the nanofluid droplet was higher than that of pure water. We can consider the effects of the initial contact angle and thermal conductivity of nanofluid as the reason for this experimental result. However, the effect of surface roughness on the evaporative heat transfer of nanofluid droplet appeared unclear.

  17. Effect of fission dynamics on the spectra and multiplicities of prompt fission neutrons

    International Nuclear Information System (INIS)

    Nix, J.R.; Madland, D.G.; Sierk, A.J.

    1985-01-01

    With the goal of examining their effect on the spectra and multiplicities of the prompt neutrons emitted in fission, we discuss recent advances in a unified macroscopic-microscopic description of large-amplitude collective nuclear dynamics. The conversion of collective energy into single-particle excitation energy is calculated for a new surface-plus-window dissipation mechanism. By solving the Hamilton equations of motion for initial conditions appropriate to fission, we obtain the average fission-fragment translational kinetic energy and excitation energy. The spectra and multiplicities of the emitted neutrons, which depend critically upon the average excitation energy, are then calculated on the basis of standard nuclear evaporation theory, taking into account the average motion of the fission fragments, the distribution of fission-fragment residual nuclear temperature, the energy dependence of the cross section for the inverse process of compound-nucleus formation, and the possibility of multiple-chance fission. Some illustrative comparisons of our calculations with experimental data are shown

  18. Evaporation in hydrology and meteorology

    NARCIS (Netherlands)

    Brandsma, T.

    1990-01-01

    In this paper the role of evaporation in hydrology and meteorology is discussed, with the emphasis on hydrology. The basic theory of evaporation is given and methods to determine evaporation are presented. Some applications of evaporation studies in literature are given in order to illustrate the

  19. Effect of the Evaporative Cooling on the Human Thermal Comfort and Heat Stress in a Greenhouse under Arid Conditions

    Directory of Open Access Journals (Sweden)

    A. M. Abdel-Ghany

    2013-01-01

    Full Text Available Thermal sensation and heat stress were evaluated in a plastic greenhouse, with and without evaporative cooling, under arid climatic conditions in Riyadh, Saudi Arabia. Suitable thermal comfort and heat stress scales were selected for the evaluation. Experiments were conducted in hot sunny days to measure the required parameters (i.e., the dry and wet bulb temperatures, globe temperature, natural wet bulb temperature, and solar radiation flux in the greenhouse. The results showed that in the uncooled greenhouse, workers are exposed to strong heat stress and would feel very hot most of the day time; they are safe from heat stress risk and would feel comfortable during night. An efficient evaporative cooling is necessary during the day to reduce heat stress and to improve the comfort conditions and is not necessary at night. In the cooled greenhouse, workers can do any activity: except at around noon they should follow a proposed working schedule, in which the different types of work were scheduled along the daytimes based on the heat stress value. To avoid heat stress and to provide comfort conditions in the greenhouses, the optimum ranges of relative humidity and air temperature are 48–55% and 24–28°C, respectively.

  20. Thermocapillary flow about an evaporating meniscus

    Science.gov (United States)

    Schmidt, G. R.; Chung, T. J.

    1992-01-01

    The steady motion and thermal behavior of an evaporating superheated liquid in a small cavity bounded by isothermal sidewalls is examined. Scaling analyses and a two-dimensional finite element model are used to investigate the influence of thermocapillarity, buoyancy, and temperature-dependent mass flux on flowfield, interfacial heat transfer, and meniscus morphology. Numerical investigations indicate the existence of two counter-rotating cells symmetric about the cavity center. Results also show that evaporation tends to counteract this circulation by directing flow toward the hotter sidewalls. Although thermocapillarity and evaporation yield different flowfield distributions, both effects tend to increase interfacial temperature and heat transfer.

  1. Black hole evaporation: a paradigm

    International Nuclear Information System (INIS)

    Ashtekar, Abhay; Bojowald, Martin

    2005-01-01

    A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: (i) resolution of the Schwarzschild singularity using quantum geometry methods and (ii) time evolution of black holes in the trapping and dynamical horizon frameworks. Quantum geometry effects introduce a major modification in the traditional spacetime diagram of black hole evaporation, providing a possible mechanism for recovery of information that is classically lost in the process of black hole formation. The paradigm is developed directly in the Lorentzian regime and necessary conditions for its viability are discussed. If these conditions are met, much of the tension between expectations based on spacetime geometry and structure of quantum theory would be resolved

  2. Duplex Tear Film Evaporation Analysis.

    Science.gov (United States)

    Stapf, M R; Braun, R J; King-Smith, P E

    2017-12-01

    Tear film thinning, hyperosmolarity, and breakup can cause irritation and damage to the human eye, and these form an area of active investigation for dry eye syndrome research. Recent research demonstrates that deficiencies in the lipid layer may cause locally increased evaporation, inducing conditions for breakup. In this paper, we explore the conditions for tear film breakup by considering a model for tear film dynamics with two mobile fluid layers, the aqueous and lipid layers. In addition, we include the effects of osmosis, evaporation as modified by the lipid, and the polar portion of the lipid layer. We solve the system numerically for reasonable parameter values and initial conditions and analyze how shifts in these cause changes to the system's dynamics.

  3. Trends in evaporation of a large subtropical lake

    Science.gov (United States)

    Hu, Cheng; Wang, Yongwei; Wang, Wei; Liu, Shoudong; Piao, Meihua; Xiao, Wei; Lee, Xuhui

    2017-07-01

    How rising temperature and changing solar radiation affect evaporation of natural water bodies remains poor understood. In this study, evaporation from Lake Taihu, a large (area 2400 km2) freshwater lake in the Yangtze River Delta, China, was simulated by the CLM4-LISSS offline lake model and estimated with pan evaporation data. Both methods were calibrated against lake evaporation measured directly with eddy covariance in 2012. Results show a significant increasing trend of annual lake evaporation from 1979 to 2013, at a rate of 29.6 mm decade-1 according to the lake model and 25.4 mm decade-1 according to the pan method. The mean annual evaporation during this period shows good agreement between these two methods (977 mm according to the model and 1007 mm according to the pan method). A stepwise linear regression reveals that downward shortwave radiation was the most significant contributor to the modeled evaporation trend, while air temperature was the most significant contributor to the pan evaporation trend. Wind speed had little impact on the modeled lake evaporation but had a negative contribution to the pan evaporation trend offsetting some of the temperature effect. Reference evaporation was not a good proxy for the lake evaporation because it was on average 20.6 % too high and its increasing trend was too large (56.5 mm decade-1).

  4. Effective capacity of multiple antenna channels: Correlation and keyhole

    KAUST Repository

    Zhong, Caijun

    2012-01-01

    In this study, the authors derive the effective capacity limits for multiple antenna channels which quantify the maximum achievable rate with consideration of link-layer delay-bound violation probability. Both correlated multiple-input single-output and multiple-input multiple-output keyhole channels are studied. Based on the closed-form exact expressions for the effective capacity of both channels, the authors look into the asymptotic high and low signal-to-noise ratio regimes, and derive simple expressions to gain more insights. The impact of spatial correlation on effective capacity is also characterised with the aid of a majorisation theory result. It is revealed that antenna correlation reduces the effective capacity of the channels and a stringent quality-of-service requirement causes a severe reduction in the effective capacity but can be alleviated by increasing the number of antennas. © 2012 The Institution of Engineering and Technology.

  5. Effect of evaporation and freezing on the salt paragenesis and habitability of brines at the Phoenix landing site

    Science.gov (United States)

    Elsenousy, Amira; Hanley, Jennifer; Chevrier, Vincent F.

    2015-07-01

    The WCL (Wet Chemistry Lab) instrument on board the Phoenix Lander identified the soluble ionic composition of the soil at the landing site. However, few studies have been conducted to understand the parent salts of these soluble ions. Here we studied the possible salt assemblages at the Phoenix landing site using two different thermodynamic models: FREZCHEM and Geochemist's Workbench (GWB). Two precipitation pathways were used: evaporation (T > 0 °C using both FREZCHEM and GWB) and freezing (T chlorate/perchlorate dominated), we calculated the resulting precipitated minerals. The results-through both freezing and evaporation-showed some common minerals that precipitated regardless of the ionic initial concentration. These ubiquitous minerals are magnesium chlorate hexahydrate Mg(ClO3)2ṡ6H2O, potassium perchlorate (KClO4) and gypsum (CaSO4ṡ2H2O). Other minerals evidence specific precipitation pathway. Precipitation of highly hydrated salts such as meridianiite (MgSO4ṡ11H2O) and MgCl2ṡ12H2O indicate freezing pathway, while precipitation of the low hydrated salts (anhydrite, kieserite and epsomite) indicate evaporation. The present hydration states of the precipitated hydrated minerals probably reflect the ongoing thermal processing and recent seasonally varying humidity conditions at the landing site, but these hydration states might not reflect the original depositional conditions. The simulations also showed the absence of Ca-perchlorate in all models, mainly because of the formation of two main salts: KClO4 and gypsum which are major sinks for ClO-4 and Ca2+ respectively. Finally, in consideration to the Martian life, it might survive at the very low temperatures and low water activities of the liquids formed. However, besides the big and widely recognized challenges to life posed by those extreme environmental parameters (especially low water activity), another main challenge for any form of life in such an environment is to maintain contact with the

  6. Alcohol: A Nutrient with Multiple Salutary Effects

    Directory of Open Access Journals (Sweden)

    Henry J. Pownall

    2015-03-01

    Full Text Available Numerous studies have shown that cardiovascular disease is lower among alcohol consumers than among nonconsumers. Many of the metabolic effects of alcohol are mediated by its terminal metabolite, acetate, which has reported insulinemic properties. There have been few rational metabolic targets that underly its cardioprotective effects until it was reported that acetate, the terminal product of alcohol metabolism, is the ligand for G-protein coupled receptor 43 (GPCR43, which is highly expressed in adipose tissue. Here, we recast much of some of the major lipid and lipoprotein effects of alcohol in the context of this newly discovered G-protein and develop a mechanistic model connecting the interaction of acetate with adipose tissue-GPCR43 with these effects. According to our model, ingestions of acetate could replace alcohol as a means of improving plasma lipid risk factors, improving glucose disposal, and reducing cardiovascular disease. Future studies should include biochemical, cell, animal, and human tests of acetate on energy metabolism.

  7. Towards a rational definition of potential evaporation

    Directory of Open Access Journals (Sweden)

    J.-P. Lhommel

    1997-01-01

    Full Text Available The concept of potential evaporation is defined on the basis of the following criteria: (i it must establish an upper limit to the evaporation process in a given environment (the term 'environment' including meteorological and surface conditions, and (ii this upper limit must be readily calculated from measured input data. It is shown that this upper limit is perfectly defined and is given by the Penman equation, applied with the corresponding meteorological data (incoming radiation and air characteristics measured at a reference height and the appropriate surface characteristics (albedo, roughness length, soil heat flux. Since each surface has its own potential evaporation, a function of its own surface characteristics, it is useful to define a reference potential evaporation as a short green grass completely shading the ground. Although the potential evaporation from a given surface is readily calculated from the Penman equation, its physical significance or interpretation is not so straightforward, because it represents only an idealized situation, not a real one. Potential evaporation is the evaporation from this surface, when saturated and extensive enough to obviate any effect of local advection, under the same meteorological conditions. Due to the feedback effects of evaporation on air characteristics, it does not represent the 'real' evaporation (i.e. the evaporation which could be physically observed in the real world from such an extensive saturated surface in these given meteorological conditions (if this saturated surface were substituted for an unsaturated one previously existing. From a rigorous standpoint, this calculated potential evaporation is not physically observable. Nevertheless, an approximate representation can be given by the evaporation from a limited saturated area, the dimension of which depends on the height of measurement of the air characteristics used as input in the Penman equation. If they are taken at a height

  8. Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

    Science.gov (United States)

    Chaiyabutr, N.; Chanpongsang, S.; Suadsong, S.

    2008-09-01

    The aim of this study was to determine how evaporative cooling modifies body function with respect to water metabolism and other variables relevant to milk synthesis in crossbred cattle. The study was conducted on two groups of 0.875HF:0.125RS crossbred Holstein cattle (87.5%) housed in an open-sided barn with a tiled roof (non-cooled animals) and in a close-sided barn under an evaporative cooling system (cooled animals). The maximum ambient temperature and relative humidity for the non-cooled group were 33°C and 61%, with the corresponding values for the evaporatively cooled barn being 28°C and 84%, respectively. The temperature humidity index (THI) of under non-cooled conditions was higher ( P glucose and triglyceride of cooled animals were not significantly different compared with values for non-cooled animals. No differences were seen in plasma hormonal levels for triiodotyronine (T3) and insulin-like growth factor-1 (IGF-1), but plasma cortisol and thyroxine (T4) levels tended to be lower in non-cooled animals. This study suggests that low cooling temperature accompanied by high humidity influences a galactopoietic effect, in part through increases in ECF, blood volume and plasma volume in association with an increase in DMI, which partitions the distribution of nutrients to the mammary gland for milk synthesis. Cooled animals were unable to maintain high milk yield as lactation advances even though a high level of body fluids was maintained during long-term cooled exposure. The decline in milk yield, coinciding with a decrease in net energy for lactation as lactation advances, could be attributed to a local change within the mammary gland.

  9. Multiple-effect diffusion solar still coupled with a vacuum-tube collector and heat pipe

    KAUST Repository

    Chong, Tze-Ling

    2014-08-01

    The present study develops a multiple-effect diffusion solar still (MEDS) with a bended-plate design in multiple-effect diffusion unit (MDU) to solve the peel-off problem of wick material. The MDU is coupled with a vacuum-tube solar collector to produce a high temperature gradient for high productivity. A heat pipe is used to transfer the solar heat to the MDU. A prototype MEDS-1L was built and tested outdoors. Four performance indexes are proposed for the performance evaluation of MEDS, including daily pure water production per unit area of glass cover, solar absorber, and evaporating surface (Mcov, Msol, Mevp, respectively), and solar distillation efficiency Rcov. The outdoor test results of MEDS-1L show that the solar collector supply temperature Th reaches 100°C at solar radiation 800Wm-2. The highest Mcov is 23.9kgm-2d-1 which is about 29% higher than the basin-type MEDS [11]. The highest value is 25.9kgm-2d-1 for Msol and 2.79kgm-2d-1 for Mevp. The measured Rcov is 1.5-2.44, higher than the basin-type MEDS (1.45-1.88). The Mcov, Msol, Mevp and Rcov of MEDS-1L are all higher than the theoretical calculation of a MEDS with a flat-plate solar collector coupled with a heat pipe (MEDS-FHP) [17].© 2014 Elsevier B.V.

  10. Annealing effects on room temperature thermoelectric performance of p-type thermally evaporated Bi-Sb-Te thin films

    Science.gov (United States)

    Singh, Sukhdeep; Singh, Janpreet; Tripathi, S. K.

    2018-05-01

    Bismuth antimony telluride (Bi-Sb-Te) compounds have been investigated for the past many decades for thermoelectric (TE) power generation and cooling purpose. We synthesized this compound with a stoichiometry Bi1.2Sb0.8Te3 through melt cool technique and thin films of as synthesized material were deposited by thermal evaporation. The prime focus of the present work is to study the influence of annealing temperature on the room temperature (RT) power factor of thin films. Electrical conductivity and Seebeck coefficient were studied and power factors were calculated which showed a peak value at 323 K. The compounds performance is comparable to some very efficient Bi-Sb-Te reported stoichiometries at RT scale. The values observed show that material has an enormous potential for energy production at ambient temperature scales.

  11. Systematics of evaporation

    International Nuclear Information System (INIS)

    Klots, C.E.

    1991-01-01

    Beginning with rather basic principles, general relations are obtained for evaporative rate constants. These are established both as a function of energy and of temperature. In parallel with this, expressions are developed for the kinetic energy distribution of the separating species. Explicit evaluation of the rate constants in the case of 'chemical' evaporation from an entity containing n monomeric units yields as a typical result k(T)(s -1 )=3.10 13 n 2/3 exp[6/n 1/3 ]exp(-ΔE a (n)/k B T). Experimental evidence in support of this relation is cited. Applications to thermionic emission are also noted. (orig.)

  12. Improvements of evaporation drag model

    International Nuclear Information System (INIS)

    Li Xiaoyan; Yang Yanhua; Xu Jijun

    2004-01-01

    A special observable experiment facility has been established, and a series of experiments have been carried out on this facility by pouring one or several high-temperature particles into a water pool. The experiment has verified the evaporation drag model, which believe the non-symmetric profile of the local evaporation rate and the local density of the vapor would bring about a resultant force on the hot particle so as to resist its motion. However, in Yang's evaporation drag model, radiation heat transfer is taken as the only way to transfer heat from hot particle to the vapor-liquid interface and all of the radiation energy is deposited on the vapor-liquid interface, thus contributing to the vaporization rate and mass balance of the vapor film. So, the heat conduction and the heat convection are taken into account in improved model. At the same time, the improved model given by this paper presented calculations of the effect of hot particles temperature on the radiation absorption behavior of water

  13. The effect of exercise therapy on fatigue in multiple sclerosis

    DEFF Research Database (Denmark)

    Andreasen, A; Stenager, E; Dalgas, U

    2011-01-01

    Fatigue occurs in the majority of patients with multiple sclerosis (MS) and therapeutic possibilities are few. Exercise therapy is a therapeutic option but no studies have systematically reviewed the existing literature evaluating the effect of exercise therapy on MS fatigue.......Fatigue occurs in the majority of patients with multiple sclerosis (MS) and therapeutic possibilities are few. Exercise therapy is a therapeutic option but no studies have systematically reviewed the existing literature evaluating the effect of exercise therapy on MS fatigue....

  14. Modelling of rate effects at multiple scales

    DEFF Research Database (Denmark)

    Pedersen, R.R.; Simone, A.; Sluys, L. J.

    2008-01-01

    , the length scale in the meso-model and the macro-model can be coupled. In this fashion, a bridging of length scales can be established. A computational analysis of  a Split Hopkinson bar test at medium and high impact load is carried out at macro-scale and meso-scale including information from  the micro-scale.......At the macro- and meso-scales a rate dependent constitutive model is used in which visco-elasticity is coupled to visco-plasticity and damage. A viscous length scale effect is introduced to control the size of the fracture process zone. By comparison of the widths of the fracture process zone...

  15. Influence of Evaporation on Soap Film Rupture.

    Science.gov (United States)

    Champougny, Lorène; Miguet, Jonas; Henaff, Robin; Restagno, Frédéric; Boulogne, François; Rio, Emmanuelle

    2018-03-13

    Although soap films are prone to evaporate due to their large surface to volume ratio, the effect of evaporation on macroscopic film features has often been disregarded in the literature. In this work, we experimentally investigate the influence of environmental humidity on soap film stability. An original experiment allows to measure both the maximum length of a film pulled at constant velocity and its thinning dynamics in a controlled atmosphere for various values of the relative humidity [Formula: see text]. At first order, the environmental humidity seems to have almost no impact on most of the film thinning dynamics. However, we find that the film length at rupture increases continuously with [Formula: see text]. To rationalize our observations, we propose that film bursting occurs when the thinning due to evaporation becomes comparable to the thinning due to liquid drainage. This rupture criterion turns out to be in reasonable agreement with an estimation of the evaporation rate in our experiment.

  16. Lattice-Boltzmann simulations of droplet evaporation

    KAUST Repository

    Ledesma-Aguilar, Rodrigo; Vella, Dominic; Yeomans, Julia M.

    2014-01-01

    © the Partner Organisations 2014. We study the utility and validity of lattice-Boltzmann (LB) simulations to explore droplet evaporation driven by a concentration gradient. Using a binary-fluid lattice-Boltzmann algorithm based on Cahn-Hilliard dynamics, we study the evaporation of planar films and 3D sessile droplets from smooth solid surfaces. Our results show that LB simulations accurately reproduce the classical regime of quasi-static dynamics. Beyond this limit, we show that the algorithm can be used to explore regimes where the evaporative and diffusive timescales are not widely separated, and to include the effect of boundaries of prescribed driving concentration. We illustrate the method by considering the evaporation of a droplet from a solid surface that is chemically patterned with hydrophilic and hydrophobic stripes. This journal is

  17. Lattice-Boltzmann simulations of droplet evaporation

    KAUST Repository

    Ledesma-Aguilar, Rodrigo

    2014-09-04

    © the Partner Organisations 2014. We study the utility and validity of lattice-Boltzmann (LB) simulations to explore droplet evaporation driven by a concentration gradient. Using a binary-fluid lattice-Boltzmann algorithm based on Cahn-Hilliard dynamics, we study the evaporation of planar films and 3D sessile droplets from smooth solid surfaces. Our results show that LB simulations accurately reproduce the classical regime of quasi-static dynamics. Beyond this limit, we show that the algorithm can be used to explore regimes where the evaporative and diffusive timescales are not widely separated, and to include the effect of boundaries of prescribed driving concentration. We illustrate the method by considering the evaporation of a droplet from a solid surface that is chemically patterned with hydrophilic and hydrophobic stripes. This journal is

  18. Improving terrestrial evaporation estimates over continental Australia through assimilation of SMOS soil moisture

    Science.gov (United States)

    Martens, B.; Miralles, D.; Lievens, H.; Fernández-Prieto, D.; Verhoest, N. E. C.

    2016-06-01

    Terrestrial evaporation is an essential variable in the climate system that links the water, energy and carbon cycles over land. Despite this crucial importance, it remains one of the most uncertain components of the hydrological cycle, mainly due to known difficulties to model the constraints imposed by land water availability on terrestrial evaporation. The main objective of this study is to assimilate satellite soil moisture observations from the Soil Moisture and Ocean Salinity (SMOS) mission into an existing evaporation model. Our over-arching goal is to find an optimal use of satellite soil moisture that can help to improve our understanding of evaporation at continental scales. To this end, the Global Land Evaporation Amsterdam Model (GLEAM) is used to simulate evaporation fields over continental Australia for the period September 2010-December 2013. SMOS soil moisture observations are assimilated using a Newtonian Nudging algorithm in a series of experiments. Model estimates of surface soil moisture and evaporation are validated against soil moisture probe and eddy-covariance measurements, respectively. Finally, an analogous experiment in which Advanced Microwave Scanning Radiometer (AMSR-E) soil moisture is assimilated (instead of SMOS) allows to perform a relative assessment of the quality of both satellite soil moisture products. Results indicate that the modelled soil moisture from GLEAM can be improved through the assimilation of SMOS soil moisture: the average correlation coefficient between in situ measurements and the modelled soil moisture over the complete sample of stations increased from 0.68 to 0.71 and a statistical significant increase in the correlations is achieved for 17 out of the 25 individual stations. Our results also suggest a higher accuracy of the ascending SMOS data compared to the descending data, and overall higher quality of SMOS compared to AMSR-E retrievals over Australia. On the other hand, the effect of soil moisture data

  19. Performance of evaporative condensers

    Energy Technology Data Exchange (ETDEWEB)

    Ettouney, Hisham M.; El-Dessouky, Hisham T.; Bouhamra, Walid; Al-Azmi, Bader

    2001-07-01

    Experimental investigation is conducted to study the performance of evaporative condensers/coolers. The analysis includes development of correlations for the external heat transfer coefficient and the system efficiency. The evaporative condenser includes two finned-tube heat exchangers. The system is designed to allow for operation of a single condenser, two condensers in parallel, and two condensers in series. The analysis is performed as a function of the water-to-air mass flow rate ratio (L/G) and the steam temperature. Also, comparison is made between the performance of the evaporative condenser and same device as an air-cooled condenser. Analysis of the collected data shows that the system efficiency increases at lower L/G ratios and higher steam temperatures. The system efficiency for various configurations for the evaporative condenser varies between 97% and 99%. Lower efficiencies are obtained for the air-cooled condenser, with values between 88% and 92%. The highest efficiency is found for the two condensers in series, followed by two condensers in parallel and then the single condenser. The parallel condenser configuration can handle a larger amount of inlet steam and can provide the required system efficiency and degree of subcooling. The correlation for the system efficiency gives a simple tool for preliminary system design. The correlation developed for the external heat transfer coefficient is found to be consistent with the available literature data. (Author)

  20. Forest evaporation models: Relationships between stand growth and evaporation

    CSIR Research Space (South Africa)

    Le Maitre, David C

    1997-06-01

    Full Text Available The relationships between forest stand structure, growth and evaporation were analysed to determine whether forest evaporation can be estimated from stand growth data. This approach permits rapid assessment of the potential impacts of afforestation...

  1. Effect of substrate temperature on the optical parameters of thermally evaporated Ge-Se-Te thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Pankaj, E-mail: pks_phy@yahoo.co.i [Department of Physics, Jaypee University of Information Technology, Waknaghat, Solan, H.P. 173215 India (India); Katyal, S.C. [Department of Physics, Jaypee University of Information Technology, Waknaghat, Solan, H.P. 173215 India (India)

    2009-05-01

    Thin films of Ge{sub 10}Se{sub 90-x}Te{sub x} (x = 0, 10, 20, 30, 40, 50) glassy alloys were deposited at three substrate temperatures (303 K, 363 K and 423 K) using conventional thermal evaporation technique at base pressure of {approx} 10{sup -4} Pa. X-ray diffraction results show that films deposited at 303 K are of amorphous nature while films deposited at 363 K and 423 K are of polycrystalline nature. The optical parameters, refractive index and optical gap have been derived from the transmission spectra (using UV-Vis-NIR spectrophotometer) of the thin films in the spectral region 400-1500 nm. This has been observed that refractive index values remain almost constant while the optical gap is found to decrease considerably with the increase of substrate temperature. The decrease in optical gap is explained on the basis of change in nature of films, from amorphous to polycrystalline state, with the increase of substrate temperature. The optical gap has also been observed to decrease with the increase of Te content.

  2. [Simultaneous determination of five effective components in Sijunzi bolus using high performance liquid chromatography-evaporation light scattering detection].

    Science.gov (United States)

    Li, Chunying; Zhang, Xiaojun

    2010-01-01

    A high performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of lobetyolin, pachymic acid, glycyrrhizic acid, atractylenoide III and atractylenolide I in Sijunzi bolus. The separation was performed on an HIQ SIL C18 V column (250 mm x 4.6 mm, 5 microm) with 0.5% acetic acid-methanol as the mobile phase of gradient elution at a flow rate of 1.0 mL/min. The detection was performed with an evaporation light scattering detector (ELSD) and the sample volume was 10 microL. The temperature of drift tube and heating grade of nebulizer was respectively set at 55 degrees C and 60% at 0.2 MPa of pressure. Nitrogen gas was used as carrier gas. Under the optimized conditions, there were good linear relationships between the logarithm values of mass concentration and the peak areas of lobetyolin, pachymic acid, glycyrrhizic acid, atractylenoide III and atractylenolide I in the ranges of 0.076 - 1.21, 0.048 -0.76, 0.153 - 2.45, 0.045 - 0.72 and 0.098 - 1.56 g/L, respectively. The recoveries of the five components were between 97.13% and 100.25%, the relative standard deviations (RSDs) were between 1.23% and 2.44%. This method is simple, rapid, accurate and suitable for the quality control of Sijunzi bolus.

  3. Thin films of polymer blends deposited by matrix-assisted pulsed laser evaporation: Effects of blending ratios

    International Nuclear Information System (INIS)

    Paun, Irina Alexandra; Ion, Valentin; Moldovan, Antoniu; Dinescu, Maria

    2011-01-01

    In this work, we show successful use of matrix-assisted pulsed laser evaporation (MAPLE) for obtaining thin films of PEG:PLGA blends, in the view of their use for controlled drug delivery. In particular, we investigate the influence of the blending ratios on the characteristics of the films. We show that the roughness of the polymeric films is affected by the ratio of each polymer within the blend. In addition, we perform Fourier transformed infrared spectroscopy (FTIR) measurements and we find that the intensities ratios of the infrared absorption bands of the two polymers are consistent with the blending ratios. Finally, we assess the optical constants of the polymeric films by spectroscopic ellipsometry (SE). We point out that the blending ratios exert an influence on the optical characteristics of the films and we validate the SE results by atomic force microscopy and UV-vis spectrophotometry. In all, we stress that the ratios in which the two polymers are blended have significant impact on the morphology, chemical structure and optical characteristics of the polymeric films deposited by MAPLE.

  4. Photoelectric properties by interface effect of organic/inorganic(CuPc/PbTe) multilayer prepared by pulsed laser deposition and thermal evaporation

    CERN Document Server

    Lee, H Y; Choi, B C; Jeong, J H; Tabata, H; Kawai, T

    1999-01-01

    Highly crystallized CuPc/PbTe multilayer are prepared at substrate temperature from room temperature to 300 .deg. C by pulsed laser deposition and thermal evaporation method. From the measurement of AFM image, these all film exhibits composed of round grains and flat matrix. For observation the interface effect of multilayer, we measured the transverse current-voltage characteristics in the dark and under illumination. The photocarrier is generated in the CuPc layer and the electron-hole pairs are separated by the steep incline of the potential near the CuPc/PbTe interface. The CuPc/PbTe multilayers in the in-plane current-voltage curve exhibit larger photoconduction effect than that of CuPc single layer.

  5. Electrochemical treatment of evaporated residue of soak liquor generated from leather industry

    International Nuclear Information System (INIS)

    Boopathy, R.; Sekaran, G.

    2013-01-01

    Highlights: • Electrochemical treatment of evaporated residue of soak liquor (ERSL) generated in Tannery. • Copper coating on electrode surface and horizontal mounting of electrodes for ERSL treatment. • Electrochemical oxidation of organic pollutants under high saline condition. • The treated solution may be evaporated to dryness to get NaCl salt for hide/skin preservation. -- Abstract: The organic and suspended solids present in soak liquor, generated from leather industry, demands treatment. The soak liquor is being segregated and evaporated in solar evaporation pans/multiple effect evaporator due to non availability of viable technology for its treatment. The residue left behind in the pans/evaporator does not carry any reuse value and also faces disposal threat due to the presence of high concentration of sodium chloride, organic and bacterial impurities. In the present investigation, the aqueous evaporated residue of soak liquor (ERSL) was treated by electrochemical oxidation. Graphite/graphite and SS304/graphite systems were used in electrochemical oxidation of organics in ERSL. Among these, graphite/graphite system was found to be effective over SS304/graphite system. Hence, the optimised conditions for the electrochemical oxidation of organics in ERSL using graphite/graphite system was evaluated by response surface methodology (RSM). The mass transport coefficient (k m ) was calculated based on pseudo-first order rate kinetics for both the electrode systems (graphite/graphite and SS304/graphite). The thermodynamic properties illustrated the electrochemical oxidation was exothermic and non-spontaneous in nature. The calculated specific energy consumption at the optimum current density of 50 mA cm −2 was 0.41 kWh m −3 for the removal of COD and 2.57 kWh m −3 for the removal of TKN

  6. Electrochemical treatment of evaporated residue of soak liquor generated from leather industry.

    Science.gov (United States)

    Boopathy, R; Sekaran, G

    2013-09-15

    The organic and suspended solids present in soak liquor, generated from leather industry, demands treatment. The soak liquor is being segregated and evaporated in solar evaporation pans/multiple effect evaporator due to non availability of viable technology for its treatment. The residue left behind in the pans/evaporator does not carry any reuse value and also faces disposal threat due to the presence of high concentration of sodium chloride, organic and bacterial impurities. In the present investigation, the aqueous evaporated residue of soak liquor (ERSL) was treated by electrochemical oxidation. Graphite/graphite and SS304/graphite systems were used in electrochemical oxidation of organics in ERSL. Among these, graphite/graphite system was found to be effective over SS304/graphite system. Hence, the optimised conditions for the electrochemical oxidation of organics in ERSL using graphite/graphite system was evaluated by response surface methodology (RSM). The mass transport coefficient (km) was calculated based on pseudo-first order rate kinetics for both the electrode systems (graphite/graphite and SS304/graphite). The thermodynamic properties illustrated the electrochemical oxidation was exothermic and non-spontaneous in nature. The calculated specific energy consumption at the optimum current density of 50 mA cm(-2) was 0.41 kWh m(-3) for the removal of COD and 2.57 kWh m(-3) for the removal of TKN. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Monte Carlo simulations of multiple scattering effects in ERD measurements

    International Nuclear Information System (INIS)

    Doyle, Barney Lee; Arstila, Kai.; Nordlumd, K.; Knapp, James Arthur

    2003-01-01

    Multiple scattering effects in ERD measurements are studied by comparing two Monte Carlo simulation codes, representing different approaches to obtain acceptable statistics, to experimental spectra measured from a HfO 2 sample with a time-of-flight-ERD setup. The results show that both codes can reproduce the absolute detection yields and the energy distributions in an adequate way. The effect of the choice of the interatomic potential in multiple scattering effects is also studied. Finally the capabilities of the MC simulations in the design of new measurement setups are demonstrated by simulating the recoil energy spectra from a WC x N y sample with a low energy heavy ion beam.

  8. Convection-enhanced water evaporation

    OpenAIRE

    B. M. Weon; J. H. Je; C. Poulard

    2011-01-01

    Water vapor is lighter than air; this can enhance water evaporation by triggering vapor convection but there is little evidence. We directly visualize evaporation of nanoliter (2 to 700 nL) water droplets resting on silicon wafer in calm air using a high-resolution dual X-ray imaging method. Temporal evolutions of contact radius and contact angle reveal that evaporation rate linearly changes with surface area, indicating convective (instead of diffusive) evaporation in nanoliter water droplet...

  9. Multiple scattering effects in depth resolution of elastic recoil detection

    International Nuclear Information System (INIS)

    Wielunski, L.S.; Harding, G.L.

    1998-01-01

    Elastic Recoil Detection (ERD) is used to profile hydrogen and other low mass elements in thin films at surface and interfaces in a similar way that Rutherford Backscattering Spectroscopy (RBS) is used to detect and profile heavy elements. It is often assumed that the depth resolutions of these two techniques are similar. However, in contrast to typical RBS, the depth resolution of ERD is limited substantially by multiple scattering. In experimental data analysis and/or spectra simulations of a typical RBS measurement multiple scattering effects are often ignored. Computer programs used in IBA, such as RUMP, HYPRA or RBX do not include multiple scattering effects at all. In this paper, using practical thin metal structures with films containing intentionally introduced hydrogen, we demonstrate experimental ERD depth resolution and sensitivity limitations. The effects of sample material and scattering angle are also discussed. (authors)

  10. Multiple scattering effects in depth resolution of elastic recoil detection

    Energy Technology Data Exchange (ETDEWEB)

    Wielunski, L.S.; Harding, G.L. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Telecommunications and Industrial Physics; Szilagyi, E. [KFKI Research Institute for Particle and Nuclear Physics, Budapest, (Hungary)

    1998-06-01

    Elastic Recoil Detection (ERD) is used to profile hydrogen and other low mass elements in thin films at surface and interfaces in a similar way that Rutherford Backscattering Spectroscopy (RBS) is used to detect and profile heavy elements. It is often assumed that the depth resolutions of these two techniques are similar. However, in contrast to typical RBS, the depth resolution of ERD is limited substantially by multiple scattering. In experimental data analysis and/or spectra simulations of a typical RBS measurement multiple scattering effects are often ignored. Computer programs used in IBA, such as RUMP, HYPRA or RBX do not include multiple scattering effects at all. In this paper, using practical thin metal structures with films containing intentionally introduced hydrogen, we demonstrate experimental ERD depth resolution and sensitivity limitations. The effects of sample material and scattering angle are also discussed. (authors). 19 refs., 4 figs.

  11. Effect of multiple austenitizing treatments on HT-9 steels

    International Nuclear Information System (INIS)

    Emigh, R.A.

    1985-12-01

    The effect of multiple austenitizing treatments on the toughness of an Fe-12Cr-1.0Mo-0.5W-0.3V (HT-9) steel was studied. The resulting microstructures were characterized by their mechanical properties, precipitated carbide distribution, and fracture surface appearance. It was proposed that multiple transformations would refine the martensite structure and improve toughness. Optical and scanning electron microscopic observations revealed that the martensite packet structure was somewhat refined by a second austenite transformation. Transmission electron microscopy studies of carbon extraction replicas showed that this multiple step treatment had eliminated grain boundary carbide films seen in single treated specimens on prior austenite grain boundaries. The 0.2% yield strength, tensile strength, and elongation were relatively unchanged, but the toughness measured by fatigue pre-cracked Charpy impact tests increased for the multiple step specimens

  12. Effect of Ge Addition on the Optical Band Gap and Refractive Index of Thermally Evaporated As2Se3 Thin Films

    Directory of Open Access Journals (Sweden)

    Pankaj Sharma

    2008-01-01

    Full Text Available The present paper reports the effect of Ge addition on the optical band gap and refractive index of As2Se3 thin films. Thin films of As2Se3 and (As2Se390Ge10 were prepared by thermal evaporation technique at base pressure 10−4 Pa. Optical band gap and refractive index were calculated by analyzing the transmission spectrum in the spectral range 400–1500 nm. The optical band gap decreases while the refractive index increases with the addition of Ge to As2Se3. The decrease of optical band gap has been explained on the basis of density of states; and the increase in refractive index has been explained on the basis increase in disorder in the system.

  13. Catalyst-free growth of ZnO nanowires on ITO seed/glass by thermal evaporation method: Effects of ITO seed layer thickness

    Energy Technology Data Exchange (ETDEWEB)

    Alsultany, Forat H., E-mail: foratusm@gmail.com; Ahmed, Naser M. [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Hassan, Z. [Institute of Nano-Optoelectronics Research and Technology Laboratory (INOR), Universiti Sains Malaysia, 11800 USM, Penang (Malaysia)

    2016-07-19

    A seed/catalyst-free growth of ZnO nanowires (ZnO-NWs) on a glass substrate were successfully fabricated using thermal evaporation technique. These nanowires were grown on ITO seed layers of different thicknesses of 25 and 75 nm, which were deposited on glass substrates by radio frequency (RF) magnetron sputtering. Prior to synthesized ITO nanowires, the sputtered ITO seeds were annealed using the continuous wave (CW) CO2 laser at 450 °C in air for 15 min. The effect of seed layer thickness on the morphological, structural, and optical properties of ZnO-NWs were systematically investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV-Vis spectrophotometer.

  14. The Effect Of Organic Surfactants On The Properties Of Common Hygroscopic Particles: Effective Densities, Reactivity And Water Evaporation Of Surfactant Coated Particles

    Science.gov (United States)

    Cuadrarodriguez, L.; Zelenyuk, A.; Imre, D.; Ellison, B.

    2006-12-01

    Measurements of atmospheric aerosol compositions routinely show that organic compounds account for a very large fraction of the particle mass. The organic compounds that make up this aerosol mass represent a wide range of molecules with a variety of properties. Many of the particles are composed of hygroscopic salts like sulfates, nitrates and sea-salt internally mixed with organics. While the properties of the hygroscopic salts are known, the effect of the organic compounds on the microphysical and chemical properties which include CCN activity is not clear. .One particularly interesting class of internally mixed particles is composed of aqueous salts solutions that are coated with organic surfactants which are molecules with long aliphatic chain and a water soluble end. Because these molecules tend to coat the particles' surfaces, a monolayer might be sufficient to drastically alter their hygroscopic properties, their CCN activity, and reactivity. The aliphatic chains, being exposed to the oxidizing atmosphere are expected to be transformed through heterogeneous chemistry, yielding complex products with mixed properties. We will report the results from a series of observations on ammonium sulfate, sodium chloride and sea salt particles coated with three types of surfactant molecules: sodium lauryl sulfate, sodium oleate and laurtrimonium chloride. We have been able to measure the effective densities of internally mixed particles with a range of surfactant concentration that start below a monolayer and extend all the way to particles composed of pure surfactant. For many of the measurements the data reveal a rather complex picture that cannot be simply interpreted in terms of the known pure-compound densities. For unsaturated hydrocarbons we observed and quantified the effect of oxidation by ozone on particle size, effective density and individual particle mass spectral signatures. One of the more important properties of these surfactants is that they can form a

  15. Evaporative and Convective Instabilities for the Evaporation of a Binary Mixture in a Bilayer System

    Science.gov (United States)

    Guo, Weidong; Narayanan, Ranga

    2006-11-01

    Evaporative convection in binary mixtures arises in a variety of industrial processes, such as drying of paint and coating technology. There have been theories devoted to this problem either by assuming a passive vapor layer or by isolating the vapor fluid dynamics. Previous work on evaporative and convective instabilities in a single component bilayer system suggests that active vapor layers play a major role in determining the instability of the interface. We have investigated the evaporation convection in binary mixtures taking into account the fluid dynamics of both phases. The liquid mixture and its vapor are assumed to be confined between two horizontal plates with a base state of zero evaporation but with linear vertical temperature profile. When the vertical temperature gradient reaches a critical value, the evaporative instability, Rayleigh and Marangoni convection set in. The effects of vapor and liquid depth, various wave numbers and initial composition of the mixture on the evaporative and convective instability are determined. The physics of the instability are explained and detailed comparison is made between the Rayleigh, Marangoni and evaporative convection in pure component and those in binary mixtures.

  16. Effect of submerged, freshwater aquatic macrophytes and littoral sediments on pan evaporation in the Lake Balaton region, Hungary

    Science.gov (United States)

    Anda, A.; Simon, B.; Soos, G.; Teixeira da Silva, J. A.; Kucserka, T.

    2016-11-01

    The evaporation (Ep) of a US Class A pan (C) with submerged, freshwater aquatic macrophytes (Potamogeton perfoliatus, Myriophyllum spicatum and Najas marina), hereafter macrophytes (Ps) and a sediment-covered bottom (S) was measured in Hungary during 2014-2015 using reference E of Shuttleworth (Eo) and Penman-Monteith crop reference evapotranspiration (crop ETo). There were two main climatic controls affecting variation in E: direct (air and water temperature) and indirect (wind-mediated change affecting the penetration of sunlight; precipitation inflow, impacting plant emergence). Lower seasonal mean Ep rates of 2.75 ± 0.89, 2.83 ± 0.91 and 3.06 ± 1.14 mm day-1 were observed in C, S and Ps, respectively, during the wet 2014. In the 2015 season, higher overall daily mean Ep rates for C, S and Ps were 3.76 ± 1.3, 4.19 ± 1.34 and 4.65 ± 1.52 mm day-1, respectively. A comparison of US Class A pan Ep containing macrophytes/sediments with that of a standard US Class A pan showed that pan coefficients (Kap and Kas) might allow for more accurate on-site lake E estimates. In 2014, seasonal mean Kas and Kap were 1.04 ± 0.14 and 1.09 ± 0.18, respectively. Slightly higher Ka values were observed during the warm and dry 2015 (Kas: 1.15 ± 0.22; Kap: 1.26 ± 0.23). A Ka value greater than 1 indicates that the Ep of a US Class A pan containing macrophytes and sediment is always higher than that of C. The calculated Eo overestimated measured Ep of Ps during the course of this study. During the warm-dry growing season, crop ETo was closest to Ep of Ps. Empirical coefficients can be useful for estimating E of lakes with submerged macrophytes more precisely. The accuracy of the estimate of Keszthely Bay's E improved by 9.85% when Ka was determined on site.

  17. Numerical simulation of droplet evaporation between two circular plates

    International Nuclear Information System (INIS)

    Bam, Hang Jin; Son, Gi Hun

    2015-01-01

    Numerical simulation is performed for droplet evaporation between two circular plates. The flow and thermal characteristics of the droplet evaporation are numerically investigated by solving the conservation equations of mass, momentum, energy and mass fraction in the liquid and gas phases. The liquid-gas interface is tracked by a sharp-interface level-set method which is modified to include the effects of evaporation at the liquid-gas interface and contact angle hysteresis at the liquid-gas-solid contact line. An analytical model to predict the droplet evaporation is also developed by simplifying the mass and vapor fraction equations in the gas phase. The numerical results demonstrate that the 1-D analytical prediction is not applicable to the high rate evaporation process. The effects of plate gap and receding contact angle on the droplet evaporation are also quantified.

  18. Mobile evaporator corrosion test results

    International Nuclear Information System (INIS)

    Rozeveld, A.; Chamberlain, D.B.

    1997-05-01

    Laboratory corrosion tests were conducted on eight candidates to select a durable and cost-effective alloy for use in mobile evaporators to process radioactive waste solutions. Based on an extensive literature survey of corrosion data, three stainless steel alloys (304L, 316L, AL-6XN), four nickel-based alloys (825, 625, 690, G-30), and titanium were selected for testing. The corrosion tests included vapor phase, liquid junction (interface), liquid immersion, and crevice corrosion tests on plain and welded samples of candidate materials. Tests were conducted at 80 degrees C for 45 days in two different test solutions: a nitric acid solution. to simulate evaporator conditions during the processing of the cesium ion-exchange eluant and a highly alkaline sodium hydroxide solution to simulate the composition of Tank 241-AW-101 during evaporation. All of the alloys exhibited excellent corrosion resistance in the alkaline test solution. Corrosion rates were very low and localized corrosion was not observed. Results from the nitric acid tests showed that only 316L stainless steel did not meet our performance criteria. The 316L welded interface and crevice specimens had rates of 22.2 mpy and 21.8 mpy, respectively, which exceeds the maximum corrosion rate of 20 mpy. The other welded samples had about the same corrosion resistance as the plain samples. None of the welded samples showed preferential weld or heat-affected zone (HAZ) attack. Vapor corrosion was negligible for all alloys. All of the alloys except 316L exhibited either open-quotes satisfactoryclose quotes (2-20 mpy) or open-quotes excellentclose quotes (<2 mpy) corrosion resistance as defined by National Association of Corrosion Engineers. However, many of the alloys experienced intergranular corrosion in the nitric acid test solution, which could indicate a susceptibility to stress corrosion cracking (SCC) in this environment

  19. The continuous similarity model of bulk soil-water evaporation

    Science.gov (United States)

    Clapp, R. B.

    1983-01-01

    The continuous similarity model of evaporation is described. In it, evaporation is conceptualized as a two stage process. For an initially moist soil, evaporation is first climate limited, but later it becomes soil limited. During the latter stage, the evaporation rate is termed evaporability, and mathematically it is inversely proportional to the evaporation deficit. A functional approximation of the moisture distribution within the soil column is also included in the model. The model was tested using data from four experiments conducted near Phoenix, Arizona; and there was excellent agreement between the simulated and observed evaporation. The model also predicted the time of transition to the soil limited stage reasonably well. For one of the experiments, a third stage of evaporation, when vapor diffusion predominates, was observed. The occurrence of this stage was related to the decrease in moisture at the surface of the soil. The continuous similarity model does not account for vapor flow. The results show that climate, through the potential evaporation rate, has a strong influence on the time of transition to the soil limited stage. After this transition, however, bulk evaporation is independent of climate until the effects of vapor flow within the soil predominate.

  20. Statistical Power in Evaluations That Investigate Effects on Multiple Outcomes: A Guide for Researchers

    Science.gov (United States)

    Porter, Kristin E.

    2018-01-01

    Researchers are often interested in testing the effectiveness of an intervention on multiple outcomes, for multiple subgroups, at multiple points in time, or across multiple treatment groups. The resulting multiplicity of statistical hypothesis tests can lead to spurious findings of effects. Multiple testing procedures (MTPs) are statistical…

  1. Interventional Effects for Mediation Analysis with Multiple Mediators.

    Science.gov (United States)

    Vansteelandt, Stijn; Daniel, Rhian M

    2017-03-01

    The mediation formula for the identification of natural (in)direct effects has facilitated mediation analyses that better respect the nature of the data, with greater consideration of the need for confounding control. The default assumptions on which it relies are strong, however. In particular, they are known to be violated when confounders of the mediator-outcome association are affected by the exposure. This complicates extensions of counterfactual-based mediation analysis to settings that involve repeatedly measured mediators, or multiple correlated mediators. VanderWeele, Vansteelandt, and Robins introduced so-called interventional (in)direct effects. These can be identified under much weaker conditions than natural (in)direct effects, but have the drawback of not adding up to the total effect. In this article, we adapt their proposal to achieve an exact decomposition of the total effect, and extend it to the multiple mediator setting. Interestingly, the proposed effects capture the path-specific effects of an exposure on an outcome that are mediated by distinct mediators, even when-as often-the structural dependence between the multiple mediators is unknown, for instance, when the direction of the causal effects between the mediators is unknown, or there may be unmeasured common causes of the mediators.

  2. Cumulative effect in multiple production processes on nuclei

    International Nuclear Information System (INIS)

    Golubyatnikova, E.S.; Shmonin, V.L.; Kalinkin, B.N.

    1989-01-01

    It is shown that the cumulative effect is a natural result of the process of hadron multiple production in nuclear reactions. Interpretation is made of the universality of slopes of inclusive spectra and other characteristics of cumulative hadrons. The character of information from such reactions is discussed, which could be helpful in studying the mechanism of multiparticle production. 27 refs.; 4 figs

  3. Field evaporation test of uranium tailings solution

    International Nuclear Information System (INIS)

    Chandler, B.L.; Shepard, T.A.; Stewart, T.A.

    1985-01-01

    A field experiment was performed to observe the effect on evaporation rate of a uranium tailings impoundment pond water as salt concentration of the water increased. The duration of the experiment was long enough to cause maximum salt concentration of the water to be attained. The solution used in the experiment was tailings pond water from an inactive uranium tailings disposal site in the initial stages of reclamation. The solution was not neutralized. The initial pH was about 1.0 decreasing to a salt gel at the end of the test. The results of the field experiment show a gradual and slight decrease in evaporation efficiency. This resulted as salt concentrations increased and verified the practical effectiveness of evaporation as a water removal method. In addition, the physical and chemical nature of the residual salts suggest that no long-term stability problem would likely result due to their presence in the impoundment during or after reclamation

  4. Miniature electron bombardment evaporation source: evaporation rate measurement

    International Nuclear Information System (INIS)

    Nehasil, V.; Masek, K.; Matolin, V.; Moreau, O.

    1997-01-01

    Miniature electron beam evaporation sources which operate on the principle of vaporization of source material, in the form of a tip, by electron bombardment are produced by several companies specialized in UHV equipment. These sources are used primarily for materials that are normally difficult to deposit due to their high evaporation temperature. They are appropriate for special applications such as heteroepitaxial thin film growth requiring a very low and well controlled deposition rate. A simple and easily applicable method of evaporation rate control is proposed. The method is based on the measurement of ion current produced by electron bombardment of evaporated atoms. The absolute evaporation flux values were measured by means of the Bayard-Alpert ion gauge, which enabled the ion current vs evaporation flux calibration curves to be plotted. (author). 1 tab., 4 figs., 6 refs

  5. PFR evaporator leak

    International Nuclear Information System (INIS)

    Smedley, J.A.

    1975-01-01

    PFR has three heat removal circuits each one having an evaporator, superheater, reheater; all separate units. The status of the system was that circuit No 3 was steaming with 10 MW thermal nuclear power; No 1 circuit was filled with sodium but with the evaporator awaiting modification to cure gas entrainment problems already reported. The leak was in No 2 circuit and was located in the evaporator unit. The evaporator is rated at 120 M thermal at full power and as such is a large unit. The circuit was filled with both sodium and water for the first time three weeks before the conference so it was recent history being reported and therefore any figures quoted should be taken as indicative only. The history of the steam generator was that it was built at works to a very high standard and underwent all the usual tests of strength, inspection of welds and helium leak testing. The steam generator is of U tube design with a tube plate to which the boiler tubes are welded, with all the welds in one of two gas spaces. The inlet and outlet sides are separated by a baffle and the salient features are illustrated in the attached figure. The unit achieved a leak tightness better than the detection limit in the helium leak test at works. This limit was assessed as being less than an equivalent leak of 10 -6 g/s water under steam generator service conditions. However even though all the steam generator units passed this test at works a further test was carried out when the circuits had been completed. The test was carried out during commissioning after sodium filling and with the units hot. The method was to introduce a mixture of helium/ argon at 500 pounds/square inch into the water side of the steam generators and measure the helium concentration in the sodium side gas spaces of the circuit. The test lasted many days and under these conditions the sensitivity is such that a leak equivalent to somewhere between 10 -7 to 10 -6 g/s equivalent water leak could be detected, i

  6. PFR evaporator leak

    Energy Technology Data Exchange (ETDEWEB)

    Smedley, J A

    1975-07-01

    PFR has three heat removal circuits each one having an evaporator, superheater, reheater; all separate units. The status of the system was that circuit No 3 was steaming with 10 MW thermal nuclear power; No 1 circuit was filled with sodium but with the evaporator awaiting modification to cure gas entrainment problems already reported. The leak was in No 2 circuit and was located in the evaporator unit. The evaporator is rated at 120 M thermal at full power and as such is a large unit. The circuit was filled with both sodium and water for the first time three weeks before the conference so it was recent history being reported and therefore any figures quoted should be taken as indicative only. The history of the steam generator was that it was built at works to a very high standard and underwent all the usual tests of strength, inspection of welds and helium leak testing. The steam generator is of U tube design with a tube plate to which the boiler tubes are welded, with all the welds in one of two gas spaces. The inlet and outlet sides are separated by a baffle and the salient features are illustrated in the attached figure. The unit achieved a leak tightness better than the detection limit in the helium leak test at works. This limit was assessed as being less than an equivalent leak of 10{sup -6} g/s water under steam generator service conditions. However even though all the steam generator units passed this test at works a further test was carried out when the circuits had been completed. The test was carried out during commissioning after sodium filling and with the units hot. The method was to introduce a mixture of helium/ argon at 500 pounds/square inch into the water side of the steam generators and measure the helium concentration in the sodium side gas spaces of the circuit. The test lasted many days and under these conditions the sensitivity is such that a leak equivalent to somewhere between 10{sup -7} to 10{sup -6} g/s equivalent water leak could be

  7. Two phases of droplet evaporation during plasma arc spraying: reply to Chen's comment about the 'rocket' effect under conditions of thermal plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Nemchinsky, V A [Key College, 225 Dania Beach Blvd, Dania Beach, FL 33040 (United States)

    2007-07-07

    The heating history of a droplet during its flight can be divided into two phases: (a) the initial phase when evaporation, although it occurs, does not change the heat balance of the droplet much (the case considered in our previous paper and (b) the final phase when the cooling due to evaporation balances the heat flux from the plasma. The later phase is considered in Chen's comment. In our reply, a very straightforward consideration demonstrates that even in the final phase of the droplet flight, the 'rocket' effect can be significant. (reply)

  8. Analysis of multiple scattering effects in optical Doppler tomography

    DEFF Research Database (Denmark)

    Yura, H.T.; Thrane, L.; Andersen, Peter E.

    2005-01-01

    Optical Doppler tomography (ODT) combines Doppler velocimetry and optical coherence tomography (OCT) to obtain high-resolution cross-sectional imaging of particle flow velocity in scattering media such as the human retina and skin. Here, we present the results of a theoretical analysis of ODT where...... multiple scattering effects are included. The purpose of this analysis is to determine how multiple scattering affects the estimation of the depth-resolved localized flow velocity. Depth-resolved velocity estimates are obtained directly from the corresponding mean or standard deviation of the observed...

  9. Effects of multiple scattering and target structure on photon emission

    International Nuclear Information System (INIS)

    Blankenbecler, R.

    1996-05-01

    The Landau-Pomeranchuk-Migdal effect is the suppression of Bethe-Heitler radiation caused by multiple scattering in the target medium. The quantum treatment given by S.D. Drell and the author for homogeneous targets of finite thickness will be reviewed. It will then be extended to structured targets. In brief, it is shown that radiators composed of separated plates or of a medium with a spatially varying radiation length can exhibit unexpected structure, even coherence maxima and minima, in their photon spectra. Finally, a functional integral method for performing the averaging implicit in multiple scattering will be briefly discussed and the leading corrections to previous results evaluated

  10. Multiple-Machine Scheduling with Learning Effects and Cooperative Games

    Directory of Open Access Journals (Sweden)

    Yiyuan Zhou

    2015-01-01

    Full Text Available Multiple-machine scheduling problems with position-based learning effects are studied in this paper. There is an initial schedule in this scheduling problem. The optimal schedule minimizes the sum of the weighted completion times; the difference between the initial total weighted completion time and the minimal total weighted completion time is the cost savings. A multiple-machine sequencing game is introduced to allocate the cost savings. The game is balanced if the normal processing times of jobs that are on the same machine are equal and an equal number of jobs are scheduled on each machine initially.

  11. Effects of applying hydrotherapy on fatigue in multiple sclerosis patients

    OpenAIRE

    Somaiyeh Ghafari; Fazlolah Ahmadi; Masood Nabavi

    2008-01-01

    (Received 10 May, 2008 ; Accepted 3 Oct, 2008) Abstract Background and purpose: Fatigue is a common symptom of Multiple Sclerosis (MS) that is purported to cause significant distress and have detrimental effects on daily living functioning, social and occupational obligations, and overall well-being. Complementary therapies are widely used by people with MS and Progressive Hydrotherapy is a form of complementary therapies. The aim of this study is to assess the effects of applying Hydrotherap...

  12. An automated tunnel evaporation measurement system for confined spaces

    Science.gov (United States)

    Salve, Rohit

    2002-04-01

    An automated tunnel evaporation-rate measurement system (TEMS) has been designed to measure automatically the evaporation from a cylinder 0·30 m in diameter and 0·10 m tall. This cylinder continuously maintains a constant height of water, with losses to evaporation replenished from a stilling cylinder connected to a water reservoir. The evaporation rate is measured by a transducer located at the bottom of the stilling well. The TEMS was tested over a period of 3 months in an underground research facility with relatively strong wind effects, changing temperature, and changing humidity. During this period, the TEMS continued to function uninterrupted, automatically measuring the evaporation amounts along a tunnel and an enclosed niche. These observations suggest that this tool can be useful for investigations of evaporation processes both in enclosed and ventilated environments. Published in 2002 by John Wiley & Sons, Ltd.

  13. Artificial weathering of oils by rotary evaporator

    International Nuclear Information System (INIS)

    Fieldhouse, B.; Hollebone, B.P.; Singh, N.R.; Tong, T.S.; Mullin, J.

    2009-01-01

    Oil weathering has a considerable affect on the behaviour, impact and ultimate fate of an oil spill. As such, efforts have been made to study weathering as a whole using bench-scale procedures. The studies are generally divided into individual processes where the effect of other major processes are introduce as an amended sample input rather than a concurrent process. The weathering process that has the greatest effect immediately following an oil spill is evaporation, particularly for lighter oils. The rotary evaporator apparatus offers a convenient means of producing artificially weathered oil for laboratory studies. This paper reported on a study that examined the representativeness of samples obtained by this method compared to pan evaporation and the impact of changes to the apparatus or method parameters on sample chemistry. Experiments were performed on Alberta Sweet Mixed Blend no. 5 in a rotary evaporator under varying conditions of temperature and air flow at ambient pressure using 2 apparatus. The rate of mass loss increased with temperature and air flow rate as expected, but the quantitative relationships could not be defined from the data due to contributions by other uncontrolled factors. It was concluded that the rotary evaporator is not suited for evaporation rate studies, but rather for producing samples suitable for use in other studies. Chemical analysis showed that the relative abundance distributions of target n-alkane hydrocarbons varied with the degree of weathering of an oil in a consistent manner at ambient pressure, regardless of the temperature, rate of air exchange or other factors related to the apparatus and procedure. The composition of the artificially weathered oil was also consistent with that from an open pan simulation of a weathered oil slick. Loss of water content varied with the conditions of evaporation because of the differential rates of evaporation due to relative humidity considerations. It was concluded that weathering

  14. Recent progress in design of evaporators and condensors

    International Nuclear Information System (INIS)

    Semeria, R.

    1981-01-01

    Heat transfer coefficients for boilers and condensors have been improved very much during the two last decades. Particularly, for sea water desalination plants, the falling liquid film evaporator and the horizontal tube evaporator were improved for having good performances with small temperature differences. A discussion follows of research undertaken at C.E.N. Grenoble (France) which leads to heat transfer enhancement in evaporators or in condensors. Principles are investigated such as role of interfaces and effect of a good nucleation in boiling. Examples of improved techniques are given; namely: - evaporators: falling film, fluted tubes, specific liquids, - condensors: fluted tubes, special materials such as titanium, droplet condensation [fr

  15. Freezing of Water Droplet due to Evaporation

    Science.gov (United States)

    Satoh, Isao; Fushinobu, Kazuyoshi; Hashimoto, Yu

    In this study, the feasibility of cooling/freezing of phase change.. materials(PCMs) due to evaporation for cold storage systems was experimentally examined. A pure water was used as the test PCM, since the latent heat due to evaporation of water is about 7 times larger than that due to freezing. A water droplet, the diameter of which was 1-4 mm, was suspended in a test cell by a fine metal wire (O. D.= 100μm),and the cell was suddenly evacuated up to the pressure lower than the triple-point pressure of water, so as to enhance the evaporation from the water surface. Temperature of the droplet was measured by a thermocouple, and the cooling/freezing behavior and the temperature profile of the droplet surface were captured by using a video camera and an IR thermo-camera, respectively. The obtained results showed that the water droplet in the evacuated cell is effectively cooled by the evaporation of water itself, and is frozen within a few seconds through remarkable supercooling state. When the initial temperature of the droplet is slightly higher than the room temperature, boiling phenomena occur in the droplet simultaneously with the freezing due to evaporation. Under such conditions, it was shown that the degree of supercooling of the droplet is reduced by the bubbles generated in the droplet.

  16. A new stationary droplet evaporation model and its validation

    Directory of Open Access Journals (Sweden)

    Fang WANG

    2017-08-01

    Full Text Available The liquid droplet evaporation character is important for not only combustion chamber design process but also high-accuracy spray combustion simulation. In this paper, the suspended droplets’ evaporation character was measured in a quiescent high-temperature environment by micro high-speed camera system. The gasoline and kerosene experimental results are consistent with the reference data. Methanol, common kerosene and aviation kerosene droplet evaporation characteristics, as well as their evaporation rate changing with temperature, were obtained. The evaporation rate experimental data were compared with the prediction result of Ranz-Marshall boiling temperature model (RMB, Ranz-Marshall low-temperature model (RML, drift flux model (DFM, mass analogy model (MAM, and stagnant film model (SFM. The disparity between the experimental data and the model prediction results was mainly caused by the neglect of the natural convection effect, which was never introduced into the droplet evaporation concept. A new droplet evaporation model with consideration of natural convection buoyancy force effect was proposed in this paper. Under the experimental conditions in this paper, the calculation results of the new droplet evaporation model were agreed with the experimental data for kerosene, methanol and other fuels, with less than 20% relative deviations. The relative deviations between the new evaporation model predictions for kerosene and the experimental data from the references were within 10%.

  17. Evaporation of Sunscreen Films: How the UV Protection Properties Change.

    Science.gov (United States)

    Binks, Bernard P; Brown, Jonathan; Fletcher, Paul D I; Johnson, Andrew J; Marinopoulos, Ioannis; Crowther, Jonathan M; Thompson, Michael A

    2016-06-01

    We have investigated the evaporation of thin sunscreen films and how the light absorption and the derived sun protection factor (SPF) change. For films consisting of solutions of common UV filters in propylene glycol (PG) as solvent, we show how evaporation generally causes three effects. First, the film area can decrease by dewetting leading to a transient increase in the average film thickness. Second, the film thins by evaporative loss of the solvent. Third, precipitation of the UV filter occurs when solvent loss causes the solubility limit to be reached. These evaporation-induced changes cause the UV absorbance of the film to decrease with resultant loss of SPF over the time scale of the evaporation. We derive an approximate model which accounts semiquantitatively for the variation of SPF with evaporation. Experimental results for solutions of different UV filters on quartz, different skin mimicking substrates, films with added nanoparticles, films with an added polymer and films with fast-evaporating decane as solvent (instead of slow evaporating PG) are discussed and compared with model calculations. Addition of either nanoparticles or polymer suppress film dewetting. Overall, it is hoped that the understanding gained about the mechanisms whereby film evaporation affects the SPF will provide useful guidance for the formulation of more effective sunscreens.

  18. Optimized evaporation technique for leachate treatment: Small scale implementation.

    Science.gov (United States)

    Benyoucef, Fatima; Makan, Abdelhadi; El Ghmari, Abderrahman; Ouatmane, Aziz

    2016-04-01

    This paper introduces an optimized evaporation technique for leachate treatment. For this purpose and in order to study the feasibility and measure the effectiveness of the forced evaporation, three cuboidal steel tubs were designed and implemented. The first control-tub was installed at the ground level to monitor natural evaporation. Similarly, the second and the third tub, models under investigation, were installed respectively at the ground level (equipped-tub 1) and out of the ground level (equipped-tub 2), and provided with special equipment to accelerate the evaporation process. The obtained results showed that the evaporation rate at the equipped-tubs was much accelerated with respect to the control-tub. It was accelerated five times in the winter period, where the evaporation rate was increased from a value of 0.37 mm/day to reach a value of 1.50 mm/day. In the summer period, the evaporation rate was accelerated more than three times and it increased from a value of 3.06 mm/day to reach a value of 10.25 mm/day. Overall, the optimized evaporation technique can be applied effectively either under electric or solar energy supply, and will accelerate the evaporation rate from three to five times whatever the season temperature. Copyright © 2016. Published by Elsevier Ltd.

  19. Evaporation of inclined water droplets

    Science.gov (United States)

    Kim, Jin Young; Hwang, In Gyu; Weon, Byung Mook

    2017-01-01

    When a drop is placed on a flat substrate tilted at an inclined angle, it can be deformed by gravity and its initial contact angle divides into front and rear contact angles by inclination. Here we study on evaporation dynamics of a pure water droplet on a flat solid substrate by controlling substrate inclination and measuring mass and volume changes of an evaporating droplet with time. We find that complete evaporation time of an inclined droplet becomes longer as gravitational influence by inclination becomes stronger. The gravity itself does not change the evaporation dynamics directly, whereas the gravity-induced droplet deformation increases the difference between front and rear angles, which quickens the onset of depinning and consequently reduces the contact radius. This result makes the evaporation rate of an inclined droplet to be slow. This finding would be important to improve understanding on evaporation dynamics of inclined droplets. PMID:28205642

  20. 242-A evaporator hazards assessment

    International Nuclear Information System (INIS)

    Johnson, T.L.

    1998-01-01

    This document establishes the technical basis in support of Emergency Planning activities for the 242-A Evaporator, on the Hanford Site. Through this document the technical basis for the development of facility specific Emergency Action Levels and the Emergency Planning Zone is demonstrated. The evaporator sues a conventional, forced-circulation, vacuum evaporation system to concentrate radioactive waste solutions. This concentration results in the reduction in waste volume and reduces the number of double-shelled tanks required to store the waste

  1. An experimental investigation of the effects of spiral angle on the evaporation heat transfer coefficients in microfin tubes with visualization technique

    Science.gov (United States)

    Oh, Se-Yoon

    A smooth tube and five microfin tubes were tested, and evaporation heat transfer coefficients were measured and compared for mass fluxes, 50, 100 and 200 kg/m2 s, and heat fluxes, 5, 10 and 20 kW/m 2, with Refrigerant 134a as a working fluid. The evaporation heat transfer coefficients at quality 0.5 were compared among the smooth and five microfin tubes with spiral angles 6, 12, 18, 25 and 44 degrees. The effect of the spiral angle on the heat transfer coefficients was examined. It was found that the optimal spiral angle where the maximum heat transfer coefficient occurs, mainly depends on mass flux. The optimal spiral angle was 18 degrees for G=50 kg/m2 s, and 6 degrees for G=100 and 200 kg/m 2 s. A borescope was used to visualize the flow on the inside wall of test tubes. The purpose was to find out the effect of the grooves on the liquid flow in microfin tubes and to explain the mechanism of heat transfer enhancement. Temperatures on the tube wall were measured at the same axial location as the imaging sensor of the borescope, and were related to the behavior of the liquid flow on the inside wall of the tubes. The liquid flow in the grooves on the wall was found to be the most important factor in enhancing heat transfer coefficients. The liquid flowed upward along the grooves and covered the upper inside wall of the microfin tubes at G=50 kg/m2 s. When heat flux increases, the liquid flow was found at a higher position. Both liquid viscosity and surface tension decrease, when temperature increases. Thus, the lower viscosity at higher heat flux facilitated the upward motion of the liquid flow in the grooves, so that the momentum force as well as the capillary effect was found to push the liquid along the grooves.* *A CD is included with dissertation containing video clips in avi format which can be viewed with media player.

  2. Effects of nearshore evaporation rates on the design of seabed gallery intake systems for SWRO facilities located along the Red Sea shoreline of Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah; Jadoon, Khan; Almashharawi, Samir; Missimer, Thomas M.

    2015-01-01

    circulation cell develops between the shoreline and deeper water offshore. Lower salinity seawater should migrate landward to replace water loss caused by evaporation with seaward moving of high-salinity water occurring along the bottom to balance the flow

  3. Evaporative cooling enhanced cold storage system

    Science.gov (United States)

    Carr, P.

    1991-10-15

    The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a portion of the added moisture. Preferably at least a portion of the added moisture comprises water condensed during the cooling of the warm air stream. 3 figures.

  4. Performance effect of multiple control forms in a Lean organization

    DEFF Research Database (Denmark)

    Kristensen, Thomas Borup; Israelsen, Poul

    2012-01-01

    Over the last decades Lean has developed into a prominent management philosophy reaching beyond shop floor tools. However, substantial support of performance effects from Lean is still scarce and at best with mixed results. Recently, research has turned its focus towards perceiving Lean...... as a control package. In this paper we present statistical support for enhanced performance coming from Lean. Furthermore, our results strongly support the perception of Lean as a set of multiple control forms (output, behavioral, and social controls) that complement each other. Therefore, performance...... is increased if the average level of control forms is increased, and performance is further increased if the control forms are balanced at the same level representing a complementary effect between them. Our data are archival data spanning multiple years in a strong Lean organization. The dependent performance...

  5. Benthic macroinvertebrates and multiple stressors : quantification of the effects of multiple stressors in field, laboratory and model settings

    NARCIS (Netherlands)

    Peeters, E.T.H.M.

    2001-01-01

    Organisms are always exposed to several simultaneously operating stressors in nature. It appears that the combined effects of multiple stressors cannot be understood as a simple product of their individual effects. To understand how multiple stressors affect the composition and functioning

  6. Turkish Undergraduates' Misconceptions of Evaporation, Evaporation Rate, and Vapour Pressure

    Science.gov (United States)

    Canpolat, Nurtac

    2006-01-01

    This study focused on students' misconceptions related to evaporation, evaporation rate, and vapour pressure. Open-ended diagnostic questions were used with 107 undergraduates in the Primary Science Teacher Training Department in a state university in Turkey. In addition, 14 students from that sample were interviewed to clarify their written…

  7. Reflection of circularly polarized light and the effect of particle distribution on circular dichroism in evaporation induced self-assembled cellulose nanocrystal thin films

    Directory of Open Access Journals (Sweden)

    D. Hewson

    2017-06-01

    Full Text Available Evaporation induced self-assembled (EISA thin films of cellulose nanocrystals (CNCs have shown great potential for displaying structural colour across the visible spectrum. They are believed primarily to reflect left handed circularly polarised (LCP light due to their natural tendency to form structures comprising left handed chirality. Accordingly the fabrication of homogenously coloured CNC thin films is challenging. Deposition of solid material towards the edge of a dried droplet, via the coffee-stain effect, is one such difficulty in achieving homogenous colour across CNC films. These effects are most easily observed in films prepared from droplets where observable reflection of visible light is localised around the edge of the dry film. We report here, the observation of both left and right hand circularly polarised (LCP/RCP light in reflection from distinct separate regions of CNC EISA thin films and we elucidate how these reflections are dependent on the distribution of CNC material within the EISA thin film. Optical models of reflection are presented which are based on structures revealed using high resolution transmission electron microscopy (TEM images of film cross sections. We have also employed spectroscopic characterisation techniques to evaluate the distribution of solid CNC material within a selection of CNC EISA thin films and we have correlated this distribution with polarised light spectra collected from each film. We conclude that film regions from which RCP light was reflected were associated with lower CNC concentrations and thicker film regions.

  8. Two-phase, mass-transport model for direct methanol fuel cells with effect of non-equilibrium evaporation and condensation

    Science.gov (United States)

    Yang, W. W.; Zhao, T. S.

    A two-phase, mass-transport model for liquid-feed direct methanol fuel cells (DMFCs) is developed by taking into account the effect of non-equilibrium evaporation and condensation of methanol and water. The comparison between the present model and other models indicates that the present model yields more reasonable predictions of cell performance. Particularly, it is shown that the models that invoke a thermodynamic-equilibrium assumption between phases will overestimate mass-transport rates of methanol and water, thereby resulting in an inaccurate prediction of cell performance. The parametric study using the present model reveals that the gas coverage at the flow channel-diffusion-layer interface is directly related to the gas-void fraction inside the anode porous region; increasing the gas-void fraction will increase the mass-transfer resistance of methanol and thus lower cell performance. The effects of the geometric dimensions of the cell structure, such as channel width and rib width, on cell performance are also investigated with the model developed in this work.

  9. Team effectiveness in academic medical libraries: a multiple case study.

    Science.gov (United States)

    Martin, Elaine Russo

    2006-07-01

    The objective of this study is to apply J. Richard Hackman's framework on team effectiveness to academic medical library settings. The study uses a qualitative, multiple case study design, employing interviews and focus groups to examine team effectiveness in three academic medical libraries. Another site was selected as a pilot to validate the research design, field procedures, and methods to be used with the cases. In all, three interviews and twelve focus groups, with approximately seventy-five participants, were conducted at the case study libraries. Hackman identified five conditions leading to team effectiveness and three outcomes dimensions that defined effectiveness. The participants in this study identified additional characteristics of effectiveness that focused on enhanced communication, leadership personality and behavior, and relationship building. The study also revealed an additional outcome dimension related to the evolution of teams. Introducing teams into an organization is not a trivial matter. Hackman's model of effectiveness has implications for designing successful library teams.

  10. Slow evaporation method and enhancement in photoluminescence ...

    Indian Academy of Sciences (India)

    nescence (PL) properties and decay time of phosphors were studied at room temperature. The YPO4 ... Keywords. Slow evaporation method; YPO4 : Eu3+, Bi3+; quenching effect; optical material. 1. ... intensity of Eu3+-doped compounds such as CaMoO4 : Bi3+, .... Figure 4 shows FESEM images of YPO4 : Eu3+ and Bi3+.

  11. BLEVE blast by expansion-controlled evaporation

    NARCIS (Netherlands)

    Berg, A.C. van den; Voort, M.M. van der; Weerheijm, J.; Versloot, N.H.A.

    2006-01-01

    This report presents a new method to calculate the blast effects originating from an exploding vessel of liquefied gas. Adequate blast calculation requires full knowledge of the blast source characteristics, that is, the release and subsequent evaporation rate of the flashing liquid. Because the

  12. Statistical Power in Evaluations That Investigate Effects on Multiple Outcomes: A Guide for Researchers

    Science.gov (United States)

    Porter, Kristin E.

    2016-01-01

    In education research and in many other fields, researchers are often interested in testing the effectiveness of an intervention on multiple outcomes, for multiple subgroups, at multiple points in time, or across multiple treatment groups. The resulting multiplicity of statistical hypothesis tests can lead to spurious findings of effects. Multiple…

  13. Gauge theories, black hole evaporation and cosmic censorship

    International Nuclear Information System (INIS)

    Davies, P.C.W.

    1981-01-01

    Recent work of Linde, which suggests that gauge theories modify the effective gravitational constant, are applied to the theory of black hole evaporation. Considerable modification of the late stages of evaporation are predicted. Contrary to expectations, the black hole never attains a sufficient temperature to enter the antigravity regime, which would represent a failure of cosmic censorship. (orig.)

  14. performance evaluation of a composite-padded evaporative cooling

    African Journals Online (AJOL)

    user

    average temperature drop and saturation efficiency in the evaporative cooler during the no-load test were 5°C and 42%, ... flow rate wetting the pad and the construction material .... principle of evaporation which results in a cooling effect.

  15. An Investigation into the Effects of Temperature Gradient on the Soil Water–Salt Transfer with Evaporation

    Directory of Open Access Journals (Sweden)

    Rong Ren

    2017-06-01

    Full Text Available Temperature gradients exist in the field under brackish water irrigation conditions, especially in northern semi–arid areas of China. Although there are many investigators dedicated to studying the mechanism of brackish water irrigation and the effect of brackish water irrigation on crops, there are fewer investigations of the effects of temperature gradient on the water–salt transport. Based on the combination of a physical experiment and a mathematical model, this study was conducted to: (a build a physical model and observe the redistribution of soil water–heat–salt transfer; (b develop a mathematical model focused on the influence of a temperature gradient on soil water and salt redistribution based on the physical model and validate the proposed model using the measured data; and (c analyze the effects of the temperature gradient on the soil water–salt transport by comparing the proposed model with the traditional water–salt model in which the effects of temperature gradient on the soil water–salt transfer are neglected. Results show that the soil temperature gradient has a definite influence on the soil water–salt migration. Moreover, the effect of temperature gradient on salt migration was greater than that of water movement.

  16. Effect of multiple plasmon excitation on single, double and multiple ionizations of C{sub 60} in collisions with fast highly charged Si ions

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Kadhane, U; Misra, D; Kumar, A; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)

    2007-06-28

    We have investigated the single and multiple ionizations of the C{sub 60} molecule in collisions with fast Si{sup q+} projectiles for various projectile charge states (q) between q = 6 and 14. The q-dependence of the ionization cross sections and their ratios is compared with the giant dipole plasmon resonance (GDPR) model. The excellent qualitative agreement with the model in case of single and double ionizations and also a reasonable agreement with the triple (and to some extent with quadruple) ionization (without evaporation) yields signify dominant contributions of the single-, double- and triple-plasmon excitations on the single- and multiple-ionization process.

  17. Mathematical model of compact type evaporator

    Science.gov (United States)

    Borovička, Martin; Hyhlík, Tomáš

    2018-06-01

    In this paper, development of the mathematical model for evaporator used in heat pump circuits is covered, with focus on air dehumidification application. Main target of this ad-hoc numerical model is to simulate heat and mass transfer in evaporator for prescribed inlet conditions and different geometrical parameters. Simplified 2D mathematical model is developed in MATLAB SW. Solvers for multiple heat and mass transfer problems - plate surface temperature, condensate film temperature, local heat and mass transfer coefficients, refrigerant temperature distribution, humid air enthalpy change are included as subprocedures of this model. An automatic procedure of data transfer is developed in order to use results of MATLAB model in more complex simulation within commercial CFD code. In the end, Proper Orthogonal Decomposition (POD) method is introduced and implemented into MATLAB model.

  18. Droplet bubbling evaporatively cools a blowfly.

    Science.gov (United States)

    Gomes, Guilherme; Köberle, Roland; Von Zuben, Claudio J; Andrade, Denis V

    2018-04-19

    Terrestrial animals often use evaporative cooling to lower body temperature. Evaporation can occur from humid body surfaces or from fluids interfaced to the environment through a number of different mechanisms, such as sweating or panting. In Diptera, some flies move tidally a droplet of fluid out and then back in the buccopharyngeal cavity for a repeated number of cycles before eventually ingesting it. This is referred to as the bubbling behaviour. The droplet fluid consists of a mix of liquids from the ingested food, enzymes from the salivary glands, and antimicrobials, associated to the crop organ system, with evidence pointing to a role in liquid meal dehydration. Herein, we demonstrate that the bubbling behaviour also serves as an effective thermoregulatory mechanism to lower body temperature by means of evaporative cooling. In the blowfly, Chrysomya megacephala, infrared imaging revealed that as the droplet is extruded, evaporation lowers the fluid´s temperature, which, upon its re-ingestion, lowers the blowfly's body temperature. This effect is most prominent at the cephalic region, less in the thorax, and then in the abdomen. Bubbling frequency increases with ambient temperature, while its cooling efficiency decreases at high air humidities. Heat transfer calculations show that droplet cooling depends on a special heat-exchange dynamic, which result in the exponential activation of the cooling effect.

  19. Flashing evaporation under different pressure levels

    International Nuclear Information System (INIS)

    Liao, Yixiang; Lucas, Dirk; Krepper, Eckhard; Rzehak, Roland

    2013-01-01

    Highlights: • CFD simulation based on two-fluid model for flashing boiling inside a vertical pipe. • Effect of pressure level on the maximum thermal energy available for evaporation. • Effect of presumed bubble size on the onset of flashing as well as evaporation rate. • Effect of pressure level on the critical bubble size that can start stable flashing. • Effect of pressure level on nucleation rate and mechanism. - Abstract: Flashing evaporation of water inside a vertical pipe under four pressure levels is investigated both experimentally and numerically. In the experiment depressurization is realized through a blow-off valve, and the evaporation rate is controlled by the opening rate and degree of the valve. In the CFD simulation phase change is assumed to be caused by thermal heat transfer between steam–water interface and the surrounding water. Consequently, the evaporation rate is determined by heat transfer coefficient, interfacial area density as well as liquid superheat degree. The simulated temporal course of cross-section averaged steam volume fraction is compared with the measured one. It is found that the increasing rate and maximum value of steam volume fraction is over-predicted under low-pressure conditions, which is mainly caused by the neglect of bubble growth in the mono-dispersed simulation. The agreement is notably improved by performing poly-dispersed simulations with the inhomogeneous MUSIG approach (IMUSIG). On the other hand an underestimation of the maximum steam volume fraction is observed in high-pressure cases, since the contribution of nucleation to the total steam generation rate becomes large as the system pressure increases. Reliable models for nucleation rate as well as bubble detachment size are indispensable for reliable predictions. An effect of the system pressure level on the nucleation mechanism is observed in the experiment

  20. Effect of thermal annealing on the structural and optical properties of Cu2FeSnS4 thin films grown by vacuum evaporation method

    Science.gov (United States)

    Oueslati, H.; Rabeh, M. Ben; Kanzari, M.

    2018-02-01

    In this work, the effect of different types of thermal annealing on the properties of Cu2FeSnS4 (CFTS) thin films deposited by thermal evaporation at room temperature on glass substrate were investigated. CFTS powder was synthesized by direct melting of the constituent elements taken in stoichiometry compositions. The X-ray diffraction experimental data indicating that the Cu2FeSnS4 powder illustrating a stannite structure in space group I\\bar {4}2m. From the XRD analysis we have found that the polycrystalline CFTS thin film was only obtained by thermal annealed in sulfur atmosphere under a high vacuum of 400 °C temperature during 2 h. Optical study reveals that the thin films have relatively high absorption coefficients (≈ 105cm-1) and the values of optical band gap energy ranged between 1.38 and 1.48 eV. Other optical parameters were evaluated according to the models of Wemple Di-Domenico and Spitzer-Fan. Finally, hot probe measurements of CFTS thin films reveal p-type conductivity.

  1. Evidence for multiple stressor interactions and effects on coral reefs.

    Science.gov (United States)

    Ban, Stephen S; Graham, Nicholas A J; Connolly, Sean R

    2014-03-01

    Concern is growing about the potential effects of interacting multiple stressors, especially as the global climate changes. We provide a comprehensive review of multiple stressor interactions in coral reef ecosystems, which are widely considered to be one of the most sensitive ecosystems to global change. First, we synthesized coral reef studies that examined interactions of two or more stressors, highlighting stressor interactions (where one stressor directly influences another) and potentially synergistic effects on response variables (where two stressors interact to produce an effect that is greater than purely additive). For stressor-stressor interactions, we found 176 studies that examined at least 2 of the 13 stressors of interest. Applying network analysis to analyze relationships between stressors, we found that pathogens were exacerbated by more costressors than any other stressor, with ca. 78% of studies reporting an enhancing effect by another stressor. Sedimentation, storms, and water temperature directly affected the largest number of other stressors. Pathogens, nutrients, and crown-of-thorns starfish were the most-influenced stressors. We found 187 studies that examined the effects of two or more stressors on a third dependent variable. The interaction of irradiance and temperature on corals has been the subject of more research (62 studies, 33% of the total) than any other combination of stressors, with many studies reporting a synergistic effect on coral symbiont photosynthetic performance (n = 19). Second, we performed a quantitative meta-analysis of existing literature on this most-studied interaction (irradiance and temperature). We found that the mean effect size of combined treatments was statistically indistinguishable from a purely additive interaction, although it should be noted that the sample size was relatively small (n = 26). Overall, although in aggregate a large body of literature examines stressor effects on coral reefs and coral

  2. In situ study of the effects of heavy-ion irradiation on co-evaporated CoSi2 films

    International Nuclear Information System (INIS)

    Allen, C.W.; Smith, D.A.

    1990-11-01

    The in situ ion irradiation capability of Argonne's HVEM-Tandem User Facility has been employed to determine the effects of 1.5 MeV Kr + irradiation and 300 kV electron irradiation on the crystallization of as-deposited and of partially crystallized 40 nm thick films of CoSi 2 . Ion fluxes ranged from 8.5 x 10 14 to 6.8 x 10 15 m -2 s -1 for which beam heating effects may be neglected. The maximum electron flux at 300 kV was 0.8 x 10 23 m -2 s -1 . The maximum temperature at which crystalline CoSi 2 is amorphized by the ion irradiation of flux = 6.8 x 10 15 m -2 s -1 is between 250 and 280 K. At higher temperatures amorphous material crystallizes by growth of any preexisting crystals and by classical nucleation and growth, with radial growth rates which are proportional to ion flux. The average degree of transformation per ion is 4 x 10 -26 m 3 per ion. Thermally induced crystallization of as-deposited films occurs above approximately 420 K. For ion doses at least as low as 3.4 x 10 16 m -2 ion irradiation at 300 K promotes thermal crystallization at 450 K, by virtue of enhanced apparant nucleation and at large doses, by enhanced growth rate. 8 refs., 2 figs

  3. Study of the Effect of Turbulence and Large Obstacles on the Evaporation from Bare Soil Surface through Coupled Free-flow and Porous-medium Flow Model

    Science.gov (United States)

    Gao, B.; Smits, K. M.

    2017-12-01

    Evaporation is a strongly coupled exchange process of mass, momentum and energy between the atmosphere and the soil. Several mechanisms influence evaporation, such as the atmospheric conditions, the structure of the soil surface, and the physical properties of the soil. Among the previous studies associated with evaporation modeling, most efforts use uncoupled models which simplify the influences of the atmosphere and soil through the use of resistance terms. Those that do consider the coupling between the free flow and porous media flow mainly consider flat terrain with grain-scale roughness. However, larger obstacles, which may form drags or ridges allowing normal convective air flow through the soil, are common in nature and may affect the evaporation significantly. Therefore, the goal of this work is to study the influence of large obstacles such as wavy surfaces on the flow behavior within the soil and exchange processes to the atmosphere under turbulent free-flow conditions. For simplicity, the soil surface with large obstacles are represented by a simple wavy surface. To do this, we modified a previously developed theory for two-phase two-component porous-medium flow, coupling it to single-phase two-component turbulent flow to simulate and analyze the evaporation from wavy soil surfaces. Detailed laboratory scale experiments using a wind tunnel interfaced with a porous media tank were carried out to test the modeling results. The characteristics of turbulent flow across a permeable wavy surface are discussed. Results demonstrate that there is an obvious recirculation zone formed at the surface, which is special because of the accumulation of water vapor and the thicker boundary layer in this area. In addition, the influences of both the free flow and porous medium on the evaporation are also analyzed. The porous medium affects the evaporation through the amount of water it can provide to the soil surface; while the atmosphere influences the evaporation

  4. Artificial Intelligence Techniques for Predicting and Mapping Daily Pan Evaporation

    Science.gov (United States)

    Arunkumar, R.; Jothiprakash, V.; Sharma, Kirty

    2017-09-01

    In this study, Artificial Intelligence techniques such as Artificial Neural Network (ANN), Model Tree (MT) and Genetic Programming (GP) are used to develop daily pan evaporation time-series (TS) prediction and cause-effect (CE) mapping models. Ten years of observed daily meteorological data such as maximum temperature, minimum temperature, relative humidity, sunshine hours, dew point temperature and pan evaporation are used for developing the models. For each technique, several models are developed by changing the number of inputs and other model parameters. The performance of each model is evaluated using standard statistical measures such as Mean Square Error, Mean Absolute Error, Normalized Mean Square Error and correlation coefficient (R). The results showed that daily TS-GP (4) model predicted better with a correlation coefficient of 0.959 than other TS models. Among various CE models, CE-ANN (6-10-1) resulted better than MT and GP models with a correlation coefficient of 0.881. Because of the complex non-linear inter-relationship among various meteorological variables, CE mapping models could not achieve the performance of TS models. From this study, it was found that GP performs better for recognizing single pattern (time series modelling), whereas ANN is better for modelling multiple patterns (cause-effect modelling) in the data.

  5. Water Evaporation from Acoustically Levitated Aqueous Solution Droplets.

    Science.gov (United States)

    Combe, Nicole A; Donaldson, D James

    2017-09-28

    We present a systematic study of the effect of solutes on the evaporation rate of acoustically levitated aqueous solution droplets by suspending individual droplets in a zero-relative humidity environment and measuring their size as a function of time. The ratios of the early time evaporation rates of six simple salts (NaCl, NaBr, NaNO 3 , KCl, MgCl 2 , CaCl 2 ) and malonic acid to that of water are in excellent agreement with predictions made by modifying the Maxwell equation to include the time-dependent water activity of the evaporating aqueous salt solution droplets. However, the early time evaporation rates of three ammonium salt solutions (NH 4 Cl, NH 4 NO 3 , (NH 4 ) 2 SO 4 ) are not significantly different from the evaporation rate of pure water. This finding is in accord with a previous report that ammonium sulfate does not depress the evaporation rate of its solutions, despite reducing its water vapor pressure, perhaps due to specific surface effects. At longer evaporation times, as the droplets approach crystallization, all but one (MgCl 2 ) of the solution evaporation rates are well described by the modified Maxwell equation.

  6. Modeling Coupled Evaporation and Seepage in Ventilated Cavities

    International Nuclear Information System (INIS)

    Ghezzehei, T.; Trautz, R.; Finsterle, S.; Cook, P.; Ahlers, C.

    2004-01-01

    Cavities excavated in unsaturated geological formations are important to activities such as nuclear waste disposal and mining. Such cavities provide a unique setting for simultaneous occurrence of seepage and evaporation. Previously, inverse numerical modeling of field liquid-release tests and associated seepage into cavities were used to provide seepage-related large-scale formation properties by ignoring the impact of evaporation. The applicability of such models was limited to the narrow range of ventilation conditions under which the models were calibrated. The objective of this study was to alleviate this limitation by incorporating evaporation into the seepage models. We modeled evaporation as an isothermal vapor diffusion process. The semi-physical model accounts for the relative humidity, temperature, and ventilation conditions of the cavities. The evaporation boundary layer thickness (BLT) over which diffusion occurs was estimated by calibration against free-water evaporation data collected inside the experimental cavities. The estimated values of BLT were 5 to 7 mm for the open underground drifts and 20 mm for niches closed off by bulkheads. Compared to previous models that neglected the effect of evaporation, this new approach showed significant improvement in capturing seepage fluctuations into open cavities of low relative humidity. At high relative-humidity values (greater than 85%), the effect of evaporation on seepage was very small

  7. Angular distributions of evaporation residues from near-barrier fusion of 32,36S on a ≅100 nuclei

    International Nuclear Information System (INIS)

    Borges, A.M.

    1986-01-01

    The angular distributions of evaporation residues from near-barrier fusion of 32,36 S ions with 92,94,96,98,100 Mo, 100,101,102,104 Ru, 103 Rh, and 104,105,106,108,110 Pd were measured in the range of 3 to 11 degrees in the laboratory system. The relative yield of the four most abundant exit evaporation channels has been extracted for all target-projectile combination at two bombarding energies, by fitting the angular distributions expected for each channel as obtained from the Monte-Carlo program TRANMI to the measured angular distribution of the evaporation residues. The total detection efficiency for the Munich-RF-Recoil Spectrometer was obtained from the relative yields, taking into account the effect due to multiple scattering, and compared with that obtained previously from the recoil velocity distributions. (orig./HSI) [de

  8. Effects of mathematics computer games on special education students' multiplicative reasoning ability

    NARCIS (Netherlands)

    Bakker, M.; Heuvel-Panhuizen, M.H.A.M. van den; Robitzsch, A.

    2016-01-01

    This study examined the effects of a teacher-delivered intervention with online mathematics mini-games on special education students' multiplicative reasoning ability (multiplication and division). The games involved declarative, procedural, as well as conceptual knowledge of multiplicative

  9. Pore-network model of evaporation-induced salt precipitation in porous media: The effect of correlations and heterogeneity

    Science.gov (United States)

    Dashtian, Hassan; Shokri, Nima; Sahimi, Muhammad

    2018-02-01

    Salt transport and precipitation in porous media constitute a set of complex and fascinating phenomena that are of considerable interest to several important problems, ranging from storage of CO2 in geological formations, to soil fertility, and protection of pavements and roads, as well as historical monuments. The phenomena occur at the pore scale and are greatly influenced by the heterogeneity of the pore space morphology. We present a pore-network (PN) model to study the phenomena. Vapor diffusion, capillary effect at the brine-vapor interface, flow of brine, and transport of salt and its precipitation in the pores that plug the pores partially or completely are all accounted for. The drying process is modeled by the invasion percolation, while transport of salt in brine is accounted for by the convective-diffusion equation. We demonstrate that the drying patterns, the clustering and connectivity of the pore throats in which salt precipitation occurs, the saturation distribution, and the drying rate are all strongly dependent upon the pore-size distribution, the correlations among the pore sizes, and the anisotropy of the pore space caused by stratification that most natural porous media contain. In particular, if the strata are more or less parallel to the direction of injection of the gas that dries out the pore space (air, for example) and/or causes salt precipitation (CO2, for example), the drying rate increases significantly. Moreover, salt tends to precipitate in clusters of neighboring pores that are parallel to the open surface of the porous medium.

  10. Multiplicity counting from fission detector signals with time delay effects

    Science.gov (United States)

    Nagy, L.; Pázsit, I.; Pál, L.

    2018-03-01

    In recent work, we have developed the theory of using the first three auto- and joint central moments of the currents of up to three fission chambers to extract the singles, doubles and triples count rates of traditional multiplicity counting (Pázsit and Pál, 2016; Pázsit et al., 2016). The objective is to elaborate a method for determining the fissile mass, neutron multiplication, and (α, n) neutron emission rate of an unknown assembly of fissile material from the statistics of the fission chamber signals, analogous to the traditional multiplicity counting methods with detectors in the pulse mode. Such a method would be an alternative to He-3 detector systems, which would be free from the dead time problems that would be encountered in high counting rate applications, for example the assay of spent nuclear fuel. A significant restriction of our previous work was that all neutrons born in a source event (spontaneous fission) were assumed to be detected simultaneously, which is not fulfilled in reality. In the present work, this restriction is eliminated, by assuming an independent, identically distributed random time delay for all neutrons arising from one source event. Expressions are derived for the same auto- and joint central moments of the detector current(s) as in the previous case, expressed with the singles, doubles, and triples (S, D and T) count rates. It is shown that if the time-dispersion of neutron detections is of the same order of magnitude as the detector pulse width, as they typically are in measurements of fast neutrons, the multiplicity rates can still be extracted from the moments of the detector current, although with more involved calibration factors. The presented formulae, and hence also the performance of the proposed method, are tested by both analytical models of the time delay as well as with numerical simulations. Methods are suggested also for the modification of the method for large time delay effects (for thermalised neutrons).

  11. Rapid Evaporation of microbubbles

    Science.gov (United States)

    Gautam, Jitendra; Esmaeeli, Asghar

    2008-11-01

    When a liquid is heated to a temperature far above its boiling point, it evaporates abruptly. Boiling of liquid at high temperatures can be explosive and destructive, and poses a potential hazard for a host of industrial processes. Explosive boiling may occur if a cold and volatile liquid is brought into contact with a hot and non-volatile liquid, or if a liquid is superheated or depressurized rapidly. Such possibilities are realized, for example, in the depressurization of low boiling point liquefied natural gas (LNG) in the pipelines or storage tanks as a result of a leak. While boiling of highly heated liquids can be destructive at macroscale, the (nearly) instantaneous pace of the process and the release of large amount of kinetic energy make the phenomena extremely attractive at microscale where it is possible to utilize the released energy to derive micromechanical systems. For instance, there is currently a growing interest in micro-explosion of liquid for generation of micro bubbles for actuation purposes. The aim of the current study is to gain a fundamental understanding of the subject using direct numerical simulations. In particular, we seek to investigate the boundary between stable and unstable nucleus growth in terms of the degree of liquid superheat and to compare the dynamics of unstable and stable growth.

  12. Prevalence and effects of multiple chemical sensitivities in Australia

    Directory of Open Access Journals (Sweden)

    Anne Steinemann

    2018-06-01

    Full Text Available Multiple chemical sensitivities (MCS is a medical condition associated with exposure to common chemical pollutants. The aims of this study are to assess the prevalence of MCS, its overlaps with asthma and fragrance sensitivity, and its health and societal effects in Australia. Data were collected in June 2016 using an on-line survey with a representative national sample (N = 1098 of adults (ages 18–65 in Australia. Results found that, across the country, 6.5% report medically diagnosed MCS, 18.9% report chemical sensitivity (being unusually sensitive to everyday chemicals and chemically formulated products, and 19.9% either or both. Among people with MCS, 74.6% also have diagnosed asthma or an asthma-like condition, and 91.5% have fragrance sensitivity, reporting health problems (such as migraine headaches when exposed to fragranced consumer products (such as air fresheners and cleaning supplies. In addition, among people with MCS, 77.5% are prevented from access to places because of fragranced products, 52.1% lost workdays or a job in the past year due to fragranced product exposure in the workplace, and 55.4% report health effects considered potentially disabling. Results indicate that MCS is a widespread disease, affecting an estimated 1 million adult Australians, with chemical sensitivity affecting another 2 million. Reducing chemical exposure to problematic sources, such as fragranced consumer products, is critical to reduce adverse effects. Keywords: MCS, Multiple chemical sensitivities, Chemical sensitivity, Asthma, Fragrance sensitivity, Fragranced consumer products

  13. Effects of dependence in high-dimensional multiple testing problems

    Directory of Open Access Journals (Sweden)

    van de Wiel Mark A

    2008-02-01

    Full Text Available Abstract Background We consider effects of dependence among variables of high-dimensional data in multiple hypothesis testing problems, in particular the False Discovery Rate (FDR control procedures. Recent simulation studies consider only simple correlation structures among variables, which is hardly inspired by real data features. Our aim is to systematically study effects of several network features like sparsity and correlation strength by imposing dependence structures among variables using random correlation matrices. Results We study the robustness against dependence of several FDR procedures that are popular in microarray studies, such as Benjamin-Hochberg FDR, Storey's q-value, SAM and resampling based FDR procedures. False Non-discovery Rates and estimates of the number of null hypotheses are computed from those methods and compared. Our simulation study shows that methods such as SAM and the q-value do not adequately control the FDR to the level claimed under dependence conditions. On the other hand, the adaptive Benjamini-Hochberg procedure seems to be most robust while remaining conservative. Finally, the estimates of the number of true null hypotheses under various dependence conditions are variable. Conclusion We discuss a new method for efficient guided simulation of dependent data, which satisfy imposed network constraints as conditional independence structures. Our simulation set-up allows for a structural study of the effect of dependencies on multiple testing criterions and is useful for testing a potentially new method on π0 or FDR estimation in a dependency context.

  14. Effect of total lymphoid irradiation in chronic progressive multiple sclerosis

    International Nuclear Information System (INIS)

    Cook, S.D.; Devereux, C.; Troiano, R.; Hafstein, M.P.; Zito, G.; Hernandez, E.; Lavenhar, M.; Vidaver, R.; Dowling, P.C.

    1986-01-01

    Total lymphoid irradiation (TLI; 1980 cGy) or sham irradiation was given to 40 patients with chronic progressive multiple sclerosis (MS) in a prospective, randomised, double-blind study. During mean follow-up of 21 months, MS patients treated with TLI has less functional decline than sham-irradiated MS patients (p<0.01). A significant relation was noted between absolute blood lymphocyte counts in the first year after TLI and subsequent course, patients with higher lymphocyte counts generally having a worse prognosis (p<0.01). TLI was well tolerated and associated with only mild short-term, and to date, long-term side-effects. (author)

  15. Multiplicity of effects and health benefits of resveratrol

    Directory of Open Access Journals (Sweden)

    Lolita Kuršvietienė

    2016-01-01

    Full Text Available Resveratrol is mainly found in grapes and red wine, also in some plants and fruits, such as peanuts, cranberries, pistachios, blueberries and bilberries. Moreover, nowadays this compound is available as purified preparation and dietary supplement. Resveratrol provides a wide range of benefits, including cardiovascular protective, antiplatelet, antioxidant, anti-inflammatory, blood glucose-lowering and anticancer activities, hence it exhibits a complex mode of action. During the recent years, these properties have been widely studied in animal and human models, both in vitro and in vivo. This paper is intended to present information published during the recent years on the biological activities and multiple effects of resveratrol.

  16. Evaporation-triggered microdroplet nucleation and the four life phases of an evaporating Ouzo drop

    Science.gov (United States)

    Tan, Huanshu; Diddens, Christian; Lv, Pengyu; Kuerten, J. G. M.; Zhang, Xuehua; Lohse, Detlef

    2016-01-01

    Evaporating liquid droplets are omnipresent in nature and technology, such as in inkjet printing, coating, deposition of materials, medical diagnostics, agriculture, the food industry, cosmetics, or spills of liquids. Whereas the evaporation of pure liquids, liquids with dispersed particles, or even liquid mixtures has intensively been studied over the past two decades, the evaporation of ternary mixtures of liquids with different volatilities and mutual solubilities has not yet been explored. Here we show that the evaporation of such ternary mixtures can trigger a phase transition and the nucleation of microdroplets of one of the components of the mixture. As a model system, we pick a sessile Ouzo droplet (as known from daily life—a transparent mixture of water, ethanol, and anise oil) and reveal and theoretically explain its four life phases: In phase I, the spherical cap-shaped droplet remains transparent while the more volatile ethanol is evaporating, preferentially at the rim of the drop because of the singularity there. This leads to a local ethanol concentration reduction and correspondingly to oil droplet nucleation there. This is the beginning of phase II, in which oil microdroplets quickly nucleate in the whole drop, leading to its milky color that typifies the so-called “Ouzo effect.” Once all ethanol has evaporated, the drop, which now has a characteristic nonspherical cap shape, has become clear again, with a water drop sitting on an oil ring (phase III), finalizing the phase inversion. Finally, in phase IV, all water has evaporated, leaving behind a tiny spherical cap-shaped oil drop. PMID:27418601

  17. The sustained effect (12 months) of a single-dose vectored thermal pulsation procedure for meibomian gland dysfunction and evaporative dry eye.

    Science.gov (United States)

    Blackie, Caroline A; Coleman, Christy A; Holland, Edward J

    2016-01-01

    To evaluate the sustained effect (up to 1 year) of a single, 12-minute vectored thermal pulsation (VTP) treatment in improving meibomian gland function and dry eye symptoms in patients with meibomian gland dysfunction and evaporative dry eye. The prospective, multicenter, open-label clinical trial included 200 subjects (400 eyes) who were randomized to a single VTP treatment (treatment group) or twice-daily, 3-month, conventional warm compress and eyelid hygiene therapy (control group). Control group subjects received crossover VTP treatment at 3 months (crossover group). Effectiveness measures of meibomian gland secretion (MGS) and dry eye symptoms were evaluated at baseline and 1, 3, 6, 9, and 12 months. Subjects with inadequate symptom relief could receive additional meibomian gland dysfunction therapy after 3 (treatment group) and 6 months (crossover group). At 3 months, the treatment group had greater mean improvement in MGS (Pdry eye symptoms (P=0.0068), compared to controls. At 12 months, 86% of the treatment group had received only one VTP treatment, and sustained a mean improvement in MGS from 6.4±3.7 (baseline) to 17.3±9.1 (Pdry eye symptoms from 44.1±20.4 to 21.6±21.3 (Pdry eye symptoms from 49.1±21.0 to 24.0±23.2 (Pdry eye symptoms, over 12 months. A single VTP treatment provides significantly greater mean improvement in meibomian gland function and dry eye symptoms as compared to a conventional, twice-daily, 3-month regimen. Early VTP intervention for meibomian gland dysfunction is associated with improved treatment outcomes.

  18. Desalting of sea water by a wall-less evaporation process

    International Nuclear Information System (INIS)

    Kassel, C.; Sachine, P.; Vuillemey, R.

    1966-06-01

    The need for fresh water supplies in many parts of the globe has given a great impetus to the study of the desalting of sea-water. Research into this problem has been very varied. Although it is possible in the more-or-less near future that methods based on freezing may be developed, only evaporation methods have industrial applications at the present time. Amongst the many techniques using this method, the most favorably placed installations from the technical and economic points of view are those based on multiple effects and wall-less heat transfer. We have defined the characteristics of a wall-less evaporation process using the various factors involved in this evaporation: energy source, corrosion, furring, heat transfer, maximum temperature, etc... The unit considered in this work has a daily output of 100,000 m 3 , and makes use of the multi-stage technique with an organic heat-carrier. The maximum temperature of the first stage is 150 deg C and the evaporation factor is 0.4. After the description of the process and, the calculation of the equipment, an economic estimate is given of the cost-price : 1.49 F/m 3 . It is likely that more detailed study of the process (technique, equipment and energy consumed) should make it possible to obtain a significant improvement in the process and to reduce the price to 1 F/m 3 . (authors) [fr

  19. Evaporative Lithography in Open Microfluidic Channel Networks

    KAUST Repository

    Lone, Saifullah

    2017-02-24

    We demonstrate a direct capillary-driven method based on wetting and evaporation of various suspensions to fabricate regular two-dimensional wires in an open microfluidic channel through continuous deposition of micro- or nanoparticles under evaporative lithography, akin to the coffee-ring effect. The suspension is gently placed in a loading reservoir connected to the main open microchannel groove on a PDMS substrate. Hydrophilic conditions ensure rapid spreading of the suspension from the loading reservoir to fill the entire channel length. Evaporation during the spreading and after the channel is full increases the particle concentration toward the end of the channel. This evaporation-induced convective transport brings particles from the loading reservoir toward the channel end where this flow deposits a continuous multilayered particle structure. The particle deposition front propagates backward over the entire channel length. The final dry deposit of the particles is thereby much thicker than the initial volume fraction of the suspension. The deposition depth is characterized using a 3D imaging profiler, whereas the deposition topography is revealed using a scanning electron microscope. The patterning technology described here is robust and passive and hence operates without an external field. This work may well become a launching pad to construct low-cost and large-scale thin optoelectronic films with variable thicknesses and interspacing distances.

  20. Application of a mechanistic model as a tool for on-line monitoring of pilot scale filamentous fungal fermentation processes-The importance of evaporation effects.

    Science.gov (United States)

    Mears, Lisa; Stocks, Stuart M; Albaek, Mads O; Sin, Gürkan; Gernaey, Krist V

    2017-03-01

    A mechanistic model-based soft sensor is developed and validated for 550L filamentous fungus fermentations operated at Novozymes A/S. The soft sensor is comprised of a parameter estimation block based on a stoichiometric balance, coupled to a dynamic process model. The on-line parameter estimation block models the changing rates of formation of product, biomass, and water, and the rate of consumption of feed using standard, available on-line measurements. This parameter estimation block, is coupled to a mechanistic process model, which solves the current states of biomass, product, substrate, dissolved oxygen and mass, as well as other process parameters including k L a, viscosity and partial pressure of CO 2 . State estimation at this scale requires a robust mass model including evaporation, which is a factor not often considered at smaller scales of operation. The model is developed using a historical data set of 11 batches from the fermentation pilot plant (550L) at Novozymes A/S. The model is then implemented on-line in 550L fermentation processes operated at Novozymes A/S in order to validate the state estimator model on 14 new batches utilizing a new strain. The product concentration in the validation batches was predicted with an average root mean sum of squared error (RMSSE) of 16.6%. In addition, calculation of the Janus coefficient for the validation batches shows a suitably calibrated model. The robustness of the model prediction is assessed with respect to the accuracy of the input data. Parameter estimation uncertainty is also carried out. The application of this on-line state estimator allows for on-line monitoring of pilot scale batches, including real-time estimates of multiple parameters which are not able to be monitored on-line. With successful application of a soft sensor at this scale, this allows for improved process monitoring, as well as opening up further possibilities for on-line control algorithms, utilizing these on-line model outputs

  1. Hydrothermal waves in evaporating sessile drops

    OpenAIRE

    Brutin, D.; Rigollet, F.; Niliot, C. Le

    2009-01-01

    Drop evaporation is a simple phenomena but still unclear concerning the mechanisms of evaporation. A common agreement of the scientific community based on experimental and numerical work evidences that most of the evaporation occurs at the triple line. However, the rate of evaporation is still empirically predicted due to the lack of knowledge on the convection cells which develop inside the drop under evaporation. The evaporation of sessile drop is more complicated than it appears due to the...

  2. Effects of radiotherapy in the treatment of multiple myeloma

    International Nuclear Information System (INIS)

    Ochtrop, Thomas Alexander

    2015-01-01

    Palliative irradiation of osteolytic lesions is a considerable component in the treatment for patients with multiple myeloma. In this study, we analyzed the efficacy of irradiation in these patients. Patients and methods: We retrospectively analyzed 153 patients with multiple myeloma who were admitted to our department between 1989 and 2013. According to the staging system of Durie and Salmon 116 patients were classified as stage III. 107/153 patients were treated with radiotherapy of at least one and up to 6 bony lesions at different times. In order to evaluate the effect of local radiotherapy on pain relief and bone recalcification a uni- and multivariate analysis was performed using a binary logistic regression model to correct for multiple measurements. Complete information on dose, fractionation and volume of radiotherapy was available from 81 patients treated in 136 target volumes for pain relief, and from 69 patients treated in 108 target volumes for recalcification. Total radiation doses varied between 8 Gy to 50 Gy (median dose 25 Gy in 2.5 Gy fractions, 5 times a week). Results: Radiotherapy resulted in complete local pain relief in 31% and partial local pain relief in 54% of the patients. In the univariate analysis, higher total radiation doses (p = 0.023) and higher age (p = 0.014) at the time of radiotherapy were significantly associated with a higher likelihood of pain relief, whereas no significant association was detected for concurrent systemic treatment, type and stage of myeloma and location of bone lesions. The same variables were independent predictors for pain relief in the multivariate analysis. Recalcification was observed in 48% of irradiated bone lesions. In the uni- and multivariate analysis higher radiation doses were significantly associated (p = 0.048) with an increased likelihood of recalcification. Side effects of radiotherapy were generally mild. Conclusions: Higher total biological radiation doses were associated with better pain

  3. Multilayer composite material and method for evaporative cooling

    Science.gov (United States)

    Buckley, Theresa M. (Inventor)

    2002-01-01

    A multilayer composite material and method for evaporative cooling of a person employs an evaporative cooling liquid that changes phase from a liquid to a gaseous state to absorb thermal energy. The evaporative cooling liquid is absorbed into a superabsorbent material enclosed within the multilayer composite material. The multilayer composite material has a high percentage of the evaporative cooling liquid in the matrix. The cooling effect can be sustained for an extended period of time because of the high percentage of phase change liquid that can be absorbed into the superabsorbent. Such a composite can be used for cooling febrile patients by evaporative cooling as the evaporative cooling liquid in the matrix changes from a liquid to a gaseous state to absorb thermal energy. The composite can be made with a perforated barrier material around the outside to regulate the evaporation rate of the phase change liquid. Alternatively, the composite can be made with an imperveous barrier material or semipermeable membrane on one side to prevent the liquid from contacting the person's skin. The evaporative cooling liquid in the matrix can be recharged by soaking the material in the liquid. The multilayer composite material can be fashioned into blankets, garments and other articles.

  4. Therapeutic Effect of Gamma Knife Radiosurgery for Multiple Brain Metastases

    Science.gov (United States)

    Lee, Chul-Kyu; Lee, Sang Ryul; Cho, Jin Mo; Yang, Kyung Ah

    2011-01-01

    Objective The aim of this study is to evaluate the therapeutic effects of gamma knife radiosurgery (GKRS) in patients with multiple brain metastases and to investigate prognostic factors related to treatment outcome. Methods We retrospectively reviewed clinico-radiological and dosimetric data of 36 patients with 4-14 brain metastases who underwent GKRS for 264 lesions between August 2008 and April 2011. The most common primary tumor site was the lung (n=22), followed by breast (n=7). At GKRS, the median Karnofsky performance scale score was 90 and the mean tumor volume was 1.2 cc (0.002-12.6). The mean prescription dose of 17.8 Gy was delivered to the mean 61.1% isodose line. Among 264 metastases, 175 lesions were assessed for treatment response by at least one imaging follow-up. Results The overall median survival after GKRS was 9.1±1.7 months. Among various factors, primary tumor control was a significant prognostic factor (11.1±1.3 months vs. 3.3±2.4 months, p=0.031). The calculated local tumor control rate at 6 and 9 months after GKRS were 87.9% and 84.2%, respectively. Paddick's conformity index (>0.75) was significantly related to local tumor control. The actuarial peritumoral edema reduction rate was 22.4% at 6 months. Conclusion According to our results, GKRS can provide beneficial effect for the patients with multiple (4 or more) brain metastases, when systemic cancer is controlled. And, careful dosimetry is essential for local tumor control. Therefore, GKRS can be considered as one of the treatment modalities for multiple brain metastase. PMID:22102945

  5. Study of multiple scattering effects in heavy ion RBS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Z; O` Connor, D J [Newcastle Univ., NSW (Australia). Dept. of Physics

    1997-12-31

    Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

  6. Study of multiple scattering effects in heavy ion RBS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Z.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics

    1996-12-31

    Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

  7. Sensitivity analysis for the effects of multiple unmeasured confounders.

    Science.gov (United States)

    Groenwold, Rolf H H; Sterne, Jonathan A C; Lawlor, Debbie A; Moons, Karel G M; Hoes, Arno W; Tilling, Kate

    2016-09-01

    Observational studies are prone to (unmeasured) confounding. Sensitivity analysis of unmeasured confounding typically focuses on a single unmeasured confounder. The purpose of this study was to assess the impact of multiple (possibly weak) unmeasured confounders. Simulation studies were performed based on parameters estimated from the British Women's Heart and Health Study, including 28 measured confounders and assuming no effect of ascorbic acid intake on mortality. In addition, 25, 50, or 100 unmeasured confounders were simulated, with various mutual correlations and correlations with measured confounders. The correlated unmeasured confounders did not need to be strongly associated with exposure and outcome to substantially bias the exposure-outcome association at interest, provided that there are sufficiently many unmeasured confounders. Correlations between unmeasured confounders, in addition to the strength of their relationship with exposure and outcome, are key drivers of the magnitude of unmeasured confounding and should be considered in sensitivity analyses. However, if the unmeasured confounders are correlated with measured confounders, the bias yielded by unmeasured confounders is partly removed through adjustment for the measured confounders. Discussions of the potential impact of unmeasured confounding in observational studies, and sensitivity analyses to examine this, should focus on the potential for the joint effect of multiple unmeasured confounders to bias results. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The Effect of Fearful Expressions on Multiple Face Tracking

    Directory of Open Access Journals (Sweden)

    Hongjun Jin

    2015-07-01

    Full Text Available How does the visual system realize dynamic tracking? This topic has become popular within cognitive science in recent years. The classical theory argues that multiple object tracking is accomplished via pre-attention visual indexes as part of a cognitively impenetrable low-level visual system. The present research aimed to investigate whether and how tracking processes are influenced by facial expressions that convey abundant social information about one’s mental state and situated environment. The results showed that participants tracked fearful faces more effectively than neutral faces. However, this advantage was only present under the low-attentional load condition, and distractor face emotion did not impact tracking performance. These findings imply that visual tracking is not driven entirely by low-level vision and encapsulated by high-level representations; rather, that facial expressions, a kind of social information, are able to influence dynamic tracking. Furthermore, the effect of fearful expressions on multiple face tracking is mediated by the availability of attentional resources.

  9. Team effectiveness in academic medical libraries: a multiple case study*

    Science.gov (United States)

    Russo Martin, Elaine

    2006-01-01

    Objectives: The objective of this study is to apply J. Richard Hackman's framework on team effectiveness to academic medical library settings. Methods: The study uses a qualitative, multiple case study design, employing interviews and focus groups to examine team effectiveness in three academic medical libraries. Another site was selected as a pilot to validate the research design, field procedures, and methods to be used with the cases. In all, three interviews and twelve focus groups, with approximately seventy-five participants, were conducted at the case study libraries. Findings: Hackman identified five conditions leading to team effectiveness and three outcomes dimensions that defined effectiveness. The participants in this study identified additional characteristics of effectiveness that focused on enhanced communication, leadership personality and behavior, and relationship building. The study also revealed an additional outcome dimension related to the evolution of teams. Conclusions: Introducing teams into an organization is not a trivial matter. Hackman's model of effectiveness has implications for designing successful library teams. PMID:16888659

  10. National Prevalence and Effects of Multiple Chemical Sensitivities.

    Science.gov (United States)

    Steinemann, Anne

    2018-03-01

    The aim of this study was to assess the prevalence of multiple chemical sensitivities (MCS), its co-occurrence with asthma and fragrance sensitivity, and effects from exposure to fragranced consumer products. A nationally representative cross-sectional population-based sample of adult Americans (n = 1137) was surveyed in June 2016. Among the population, 12.8% report medically diagnosed MCS and 25.9% report chemical sensitivity. Of those with MCS, 86.2% experience health problems, such as migraine headaches, when exposed to fragranced consumer products; 71.0% are asthmatic; 70.3% cannot access places that use fragranced products such as air fresheners; and 60.7% lost workdays or a job in the past year due to fragranced products in the workplace. Prevalence of diagnosed MCS has increased over 300%, and self-reported chemical sensitivity over 200%, in the past decade. Reducing exposure to fragranced products could help reduce adverse health and societal effects.

  11. Assessing Natural Direct and Indirect Effects Through Multiple Pathways

    DEFF Research Database (Denmark)

    Lange, T; Rasmussen, M; Thygesen, Lau Caspar

    2014-01-01

    . The approach is an extension of the natural effect models proposed by Lange et al. (Am J Epidemiol. 2012;176(3):190-195). By allowing the analysis of distinct multiple pathways, the suggested approach adds to the capabilities of modern mediation techniques. Furthermore, the approach can be implemented using......Within the fields of epidemiology, interventions research and social sciences researchers are often faced with the challenge of decomposing the effect of an exposure into different causal pathways working through defined mediator variables. The goal of such analyses is often to understand...... the mechanisms of the system or to suggest possible interventions. The case of a single mediator, thus implying only 2 causal pathways (direct and indirect) from exposure to outcome, has been extensively studied. By using the framework of counterfactual variables, researchers have established theoretical...

  12. Effective field theories for superconducting systems with multiple Fermi surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Braga, P.R., E-mail: pedro.rangel.braga@gmail.com [Departamento de Física Teórica, Instituto de Física, UERJ - Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, 20550-013 Maracanã, Rio de Janeiro (Brazil); Granado, D.R., E-mail: diegorochagrana@uerj.br [Departamento de Física Teórica, Instituto de Física, UERJ - Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, 20550-013 Maracanã, Rio de Janeiro (Brazil); Department of Physics and Astronomy, Ghent University, Krijgslaan 281-S9, 9000 Gent (Belgium); Guimaraes, M.S., E-mail: msguimaraes@uerj.br [Departamento de Física Teórica, Instituto de Física, UERJ - Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier 524, 20550-013 Maracanã, Rio de Janeiro (Brazil); Wotzasek, C., E-mail: clovis@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, 21941-972, Rio de Janeiro (Brazil)

    2016-11-15

    In this work we investigate the description of superconducting systems with multiple Fermi surfaces. For the case of one Fermi surface we re-obtain the result that the superconductor is more precisely described as a topological state of matter. Studying the case of more than one Fermi surface, we obtain the effective theory describing a time reversal symmetric topological superconductor. These results are obtained by employing a general procedure to construct effective low energy actions describing states of electromagnetic systems interacting with charges and defects. The procedure consists in taking into account the proliferation or dilution of these charges and defects and its consequences for the low energy description of the electromagnetic response of the system. We find that the main ingredient entering the low energy characterization of the system with more than one Fermi surface is a non-conservation of the canonical supercurrent triggered by particular vortex configurations.

  13. Analytical Solutions of Heat Transfer and Film Thickness with Slip Condition Effect in Thin-Film Evaporation for Two-Phase Flow in Microchannel

    Directory of Open Access Journals (Sweden)

    Ahmed Jassim Shkarah

    2015-01-01

    Full Text Available Physical and mathematical model has been developed to predict the two-phase flow and heat transfer in a microchannel with evaporative heat transfer. Sample solutions to the model were obtained for both analytical analysis and numerical analysis. It is assumed that the capillary pressure is neglected (Morris, 2003. Results are provided for liquid film thickness, total heat flux, and evaporating heat flux distribution. In addition to the sample calculations that were used to illustrate the transport characteristics, computations based on the current model were performed to generate results for comparisons with the analytical results of Wang et al. (2008 and Wayner Jr. et al. (1976. The calculated results from the current model match closely with those of analytical results of Wang et al. (2008 and Wayner Jr. et al. (1976. This work will lead to a better understanding of heat transfer and fluid flow occurring in the evaporating film region and develop an analytical equation for evaporating liquid film thickness.

  14. Prediction by artificial neural networks of the physicochemical quality of cane molasses vinegar by time-temperature effect of food to flash evaporator-distiller

    Directory of Open Access Journals (Sweden)

    Víctor Vásquez V

    2010-03-01

    Full Text Available It was predicted via Artificial Neural Networks (ANN important physicochemical characteristics of molasses vinegar: pH, density, total acidity, ethanol, total aldehydes and furfural, obtained by flash evaporation operations and flash distillation clarification. Alcoholic and acetic fermented molasses were fed to a flash evaporator at four temperatures (61, 66, 71 and 76 ° C and in three times (25, 35 and 45 min. The prediction was made with two networks: ANN and ANN-A-B, both with good performance. The ANN-A was of the feedforward (FF type with Backpropagation (BP training algorithms and set of Levenberg-Marquardt (LM weights adjustment, topology: 6 inputs (operations data of flash evaporation-distillation, 7 linear outputs (physicochemical characteristics, 9 tangent sigmoidal neurons in 1 hidden layer, 0.5 moment coefficient, 0.01 learning rate, 0.0001 error goal and 20 training stages. The ANN-A showed better performance than a statistical model of first order. The ANN-B also FF, BP and LM algorithms, topology: 2 inputs (data from flash evaporation, 7 linear outputs (physical and chemical characteristics, 84 logarithm sigmoid neurons in 1 hidden layer, 0.5 moment coefficient, 0.01 learning rate, 0.0001 error goal and 300 training stages. The ANN-B showed the same predictive capacity as a statistical model of the first-order with interaction of terms.

  15. Dual manifold heat pipe evaporator

    Science.gov (United States)

    Adkins, D.R.; Rawlinson, K.S.

    1994-01-04

    An improved evaporator section is described for a dual manifold heat pipe. Both the upper and lower manifolds can have surfaces exposed to the heat source which evaporate the working fluid. The tubes in the tube bank between the manifolds have openings in their lower extensions into the lower manifold to provide for the transport of evaporated working fluid from the lower manifold into the tubes and from there on into the upper manifold and on to the condenser portion of the heat pipe. A wick structure lining the inner walls of the evaporator tubes extends into both the upper and lower manifolds. At least some of the tubes also have overflow tubes contained within them to carry condensed working fluid from the upper manifold to pass to the lower without spilling down the inside walls of the tubes. 1 figure.

  16. The evaporative vector: Homogeneous systems

    International Nuclear Information System (INIS)

    Klots, C.E.

    1987-05-01

    Molecular beams of van der Waals molecules are the subject of much current research. Among the methods used to form these beams, three-sputtering, laser ablation, and the sonic nozzle expansion of neat gases - yield what are now recognized to be ''warm clusters.'' They contain enough internal energy to undergo a number of first-order processes, in particular that of evaporation. Because of this evaporation and its attendant cooling, the properties of such clusters are time-dependent. The states of matter which can be arrived at via an evaporative vector on a typical laboratory time-scale are discussed. Topics include the (1) temperatures, (2) metastability, (3) phase transitions, (4) kinetic energies of fragmentation, and (5) the expression of magical properties, all for evaporating homogeneous clusters

  17. Predicting the cumulative effect of multiple disturbances on seagrass connectivity.

    Science.gov (United States)

    Grech, Alana; Hanert, Emmanuel; McKenzie, Len; Rasheed, Michael; Thomas, Christopher; Tol, Samantha; Wang, Mingzhu; Waycott, Michelle; Wolter, Jolan; Coles, Rob

    2018-03-15

    The rate of exchange, or connectivity, among populations effects their ability to recover after disturbance events. However, there is limited information on the extent to which populations are connected or how multiple disturbances affect connectivity, especially in coastal and marine ecosystems. We used network analysis and the outputs of a biophysical model to measure potential functional connectivity and predict the impact of multiple disturbances on seagrasses in the central Great Barrier Reef World Heritage Area (GBRWHA), Australia. The seagrass networks were densely connected, indicating that seagrasses are resilient to the random loss of meadows. Our analysis identified discrete meadows that are important sources of seagrass propagules and that serve as stepping stones connecting various different parts of the network. Several of these meadows were close to urban areas or ports and likely to be at risk from coastal development. Deep water meadows were highly connected to coastal meadows and may function as a refuge, but only for non-foundation species. We evaluated changes to the structure and functioning of the seagrass networks when one or more discrete meadows were removed due to multiple disturbance events. The scale of disturbance required to disconnect the seagrass networks into two or more components was on average >245 km, about half the length of the metapopulation. The densely connected seagrass meadows of the central GBRWHA are not limited by the supply of propagules; therefore, management should focus on improving environmental conditions that support natural seagrass recruitment and recovery processes. Our study provides a new framework for assessing the impact of global change on the connectivity and persistence of coastal and marine ecosystems. Without this knowledge, management actions, including coastal restoration, may prove unnecessary and be unsuccessful. © 2018 John Wiley & Sons Ltd.

  18. Marangoni Flow Induced Evaporation Enhancement on Binary Sessile Drops.

    Science.gov (United States)

    Chen, Pin; Harmand, Souad; Ouenzerfi, Safouene; Schiffler, Jesse

    2017-06-15

    The evaporation processes of pure water, pure 1-butanol, and 5% 1-butanol aqueous solution drops on heated hydrophobic substrates are investigated to determine the effect of temperature on the drop evaporation behavior. The evolution of the parameters (contact angle, diameter, and volume) during evaporation measured using a drop shape analyzer and the infrared thermal mapping of the drop surface recorded by an infrared camera were used in investigating the evaporation process. The pure 1-butanol drop does not show any thermal instability at different substrate temperatures, while the convection cells created by the thermal Marangoni effect appear on the surface of the pure water drop from 50 °C. Because 1-butanol and water have different surface tensions, the infrared video of the 5% 1-butanol aqueous solution drop shows that the convection cells are generated by the solutal Marangoni effect at any substrate temperature. Furthermore, when the substrate temperature exceeds 50 °C, coexistence of the thermal and solutal Marangoni flows is observed. By analyzing the relation between the ratio of the evaporation rate of pure water and 1-butanol aqueous solution drops and the Marangoni number, a series of empirical equations for predicting the evaporation rates of pure water and 1-butanol aqueous solution drops at the initial time as well as the equations for the evaporation rate of 1-butanol aqueous solution drop before the depletion of alcohol are derived. The results of these equations correspond fairly well to the experimental data.

  19. Direction of Effects in Multiple Linear Regression Models.

    Science.gov (United States)

    Wiedermann, Wolfgang; von Eye, Alexander

    2015-01-01

    Previous studies analyzed asymmetric properties of the Pearson correlation coefficient using higher than second order moments. These asymmetric properties can be used to determine the direction of dependence in a linear regression setting (i.e., establish which of two variables is more likely to be on the outcome side) within the framework of cross-sectional observational data. Extant approaches are restricted to the bivariate regression case. The present contribution extends the direction of dependence methodology to a multiple linear regression setting by analyzing distributional properties of residuals of competing multiple regression models. It is shown that, under certain conditions, the third central moments of estimated regression residuals can be used to decide upon direction of effects. In addition, three different approaches for statistical inference are discussed: a combined D'Agostino normality test, a skewness difference test, and a bootstrap difference test. Type I error and power of the procedures are assessed using Monte Carlo simulations, and an empirical example is provided for illustrative purposes. In the discussion, issues concerning the quality of psychological data, possible extensions of the proposed methods to the fourth central moment of regression residuals, and potential applications are addressed.

  20. Effectiveness of multiple sclerosis treatment with current immunomodulatory drugs.

    Science.gov (United States)

    Milo, Ron

    2015-04-01

    Multiple sclerosis (MS) is a chronic inflammatory disease of the CNS of a putative autoimmune origin characterized by neurologic dysfunction disseminated in space and time due to demyelination and axonal loss that results in progressive disability. Recent advances in understanding the immune pathogenesis of the disease resulted in the introduction of numerous effective immunomodulatoty drugs having diverse mechanisms of action, modes of administration and risk-benefit profiles. This results in more complex albeit more promising treatment selection and choices. The epidemiology, clinical features, pathogenesis and diagnosis of the disease are discussed. The mode of action and main characteristics of current immunomodulatory drugs for MS and their place in the therapeutic algorithm of the disease based on evidence from clinical trials are described. Speculation on new paradigms, treatment goals and outcome measures aimed at improving the landscape of MS treatment is presented. Multiple disease, drug and patient-related factors should be taken into consideration when selecting the appropriate drug and treatment strategy to the appropriate patient, thus paving the road for personalized medicine in MS.

  1. Parametric study of thin film evaporation from nanoporous membranes

    Science.gov (United States)

    Wilke, Kyle L.; Barabadi, Banafsheh; Lu, Zhengmao; Zhang, TieJun; Wang, Evelyn N.

    2017-10-01

    The performance and lifetime of advanced electronics are often dictated by the ability to dissipate heat generated within the device. Thin film evaporation from nanoporous membranes is a promising thermal management approach, which reduces the thermal transport distance across the liquid film while also providing passive capillary pumping of liquid to the evaporating interface. In this work, we investigated the dependence of thin film evaporation from nanoporous membranes on a variety of geometric parameters. Anodic aluminum oxide membranes were used as experimental templates, where pore radii of 28-75 nm, porosities of 0.1-0.35, and meniscus locations down to 1 μm within the pore were tested. We demonstrated different heat transfer regimes and observed more than an order of magnitude increase in dissipated heat flux by operating in the pore-level evaporation regime. The pore diameter had little effect on pore-level evaporation performance due to the negligible conduction resistance from the pore wall to the evaporating interface. The dissipated heat flux scaled with porosity as the evaporative area increased. Furthermore, moving the meniscus as little as 1 μm into the pore decreased the dissipated heat flux by more than a factor of two due to the added resistance to vapor escaping the pore. The experimental results elucidate thin film evaporation from nanopores and confirm findings of recent modeling efforts. This work also provides guidance for the design of future thin film evaporation devices for advanced thermal management. Furthermore, evaporation from nanopores is relevant to water purification, chemical separations, microfluidics, and natural processes such as transpiration.

  2. Evaporation of Particle-Stabilized Emulsion Sunscreen Films.

    Science.gov (United States)

    Binks, Bernard P; Fletcher, Paul D I; Johnson, Andrew J; Marinopoulos, Ioannis; Crowther, Jonathan M; Thompson, Michael A

    2016-08-24

    We recently showed (Binks et al., ACS Appl. Mater. Interfaces, 2016, DOI: 10.1021/acsami.6b02696) how evaporation of sunscreen films consisting of solutions of molecular UV filters leads to loss of UV light absorption and derived sun protection factor (SPF). In the present work, we investigate evaporation-induced effects for sunscreen films consisting of particle-stabilized emulsions containing a dissolved UV filter. The emulsions contained either droplets of propylene glycol (PG) in squalane (SQ), droplets of SQ in PG or droplets of decane in PG. In these different emulsion types, the SQ is involatile and shows no evaporation, the PG is volatile and evaporates relatively slowly, whereas the decane is relatively very volatile and evaporates quickly. We have measured the film mass and area, optical micrographs of the film structure, and the UV absorbance spectra during evaporation. For emulsion films containing the involatile SQ, evaporation of the PG causes collapse of the emulsion structure with some loss of specular UV absorbance due to light scattering. However, for these emulsions with droplets much larger than the wavelength of light, the light is scattered only at small forward angles so does not contribute to the diffuse absorbance and the film SPF. The UV filter remains soluble throughout the evaporation and thus the UV absorption by the filter and the SPF remain approximately constant. Both PG-in-SQ and SQ-in-PG films behave similarly and do not show area shrinkage by dewetting. In contrast, the decane-in-PG film shows rapid evaporative loss of the decane, followed by slower loss of the PG resulting in precipitation of the UV filter and film area shrinkage by dewetting which cause the UV absorbance and derived SPF to decrease. Measured UV spectra during evaporation are in reasonable agreement with spectra calculated using models discussed here.

  3. Active gas adsorption-promoted evaporation of tungsten and niobium in strong electric fields

    International Nuclear Information System (INIS)

    Ksenofontov, V.A.; Kul'ko, V.B.; Mikhajlovskij, I.M.

    1980-01-01

    Field-ion methods and pulsed mass-spectrometeric analysis are used to study field evaporation of tungsten and niobium affected by nitrogen and hydrogen. Active gas-promoted evaporation is found to take place at field intensities high enough for the field ionization of active gases. The evaporating field intensity is established to increase from 1.45x10 8 to 5.5x10 8 V/cm while passing from continuous to pulsed conditions of evaporation, this testifies to the change of the mechanism of the promoted evaporation. Under the effect of active gases, the evaporation rate essentially depends on the surface state. It is shown that in the microcrystals irradiated with 1-3 kV helium ions, the dependence of the evaporation rate of Nb in hydrogen on the field intensity gets monotonous. The obtained results are in fair agreement with the recombination model of a promoted evaporation [ru

  4. DWPF Recycle Evaporator Simulant Tests

    International Nuclear Information System (INIS)

    Stone, M

    2005-01-01

    Testing was performed to determine the feasibility and processing characteristics of an evaporation process to reduce the volume of the recycle stream from the Defense Waste Processing Facility (DWPF). The concentrated recycle would be returned to DWPF while the overhead condensate would be transferred to the Effluent Treatment Plant. Various blends of evaporator feed were tested using simulants developed from characterization of actual recycle streams from DWPF and input from DWPF-Engineering. The simulated feed was evaporated in laboratory scale apparatus to target a 30X volume reduction. Condensate and concentrate samples from each run were analyzed and the process characteristics (foaming, scaling, etc) were visually monitored during each run. The following conclusions were made from the testing: Concentration of the ''typical'' recycle stream in DWPF by 30X was feasible. The addition of DWTT recycle streams to the typical recycle stream raises the solids content of the evaporator feed considerably and lowers the amount of concentration that can be achieved. Foaming was noted during all evaporation tests and must be addressed prior to operation of the full-scale evaporator. Tests were conducted that identified Dow Corning 2210 as an antifoam candidate that warrants further evaluation. The condensate has the potential to exceed the ETP WAC for mercury, silicon, and TOC. Controlling the amount of equipment decontamination recycle in the evaporator blend would help meet the TOC limits. The evaporator condensate will be saturated with mercury and elemental mercury will collect in the evaporator condensate collection vessel. No scaling on heating surfaces was noted during the tests, but splatter onto the walls of the evaporation vessels led to a buildup of solids. These solids were difficult to remove with 2M nitric acid. Precipitation of solids was not noted during the testing. Some of the aluminum present in the recycle streams was converted from gibbsite to

  5. Effective arithmetic in finite fields based on Chudnovsky's multiplication algorithm

    OpenAIRE

    Atighehchi , Kévin; Ballet , Stéphane; Bonnecaze , Alexis; Rolland , Robert

    2016-01-01

    International audience; Thanks to a new construction of the Chudnovsky and Chudnovsky multiplication algorithm, we design efficient algorithms for both the exponentiation and the multiplication in finite fields. They are tailored to hardware implementation and they allow computations to be parallelized, while maintaining a low number of bilinear multiplications.À partir d'une nouvelle construction de l'algorithme de multiplication de Chudnovsky et Chudnovsky, nous concevons des algorithmes ef...

  6. Humidification - Fogging and other evaporative cooling in greenhouses

    NARCIS (Netherlands)

    Nederhoff, E.M.; Weel, van P.A.

    2011-01-01

    Fogging, misting, roof sprinklers, pad-and-fan and other techniques based on water evaporation are effective tools for improving the growing conditions in a greenhouse when humidity is low. They should be used wisely though.

  7. Evaporator line for special electron tubes, in particular electron multipliers

    International Nuclear Information System (INIS)

    Richter, M.

    1984-01-01

    The invention has been aimed at reducing the effort for preventing short circuits in achieving certain material-dependent effects e.g. secondary emission, by deposition through evaporation in the production of electron tubes, in particular electron multipliers

  8. Total evaporation in thermal ionization mass spectrometry

    International Nuclear Information System (INIS)

    Callis, E.L.; Cappis, J.H.

    1996-01-01

    Experiments were conducted to assess the effects of impurities on the total evaporation method for mass spectrometric measurement of the isotope ratio of uranium. Standard samples were spiked with Na, Ca, Fe, Zr and Ba. The results indicated that only Fe, and possible Na, displayed any interference, and then only at high concentrations. One problem limiting the accuracy of the method is the determination of the relative efficiency of the collectors in the multicollector system. 3 refs., 1 tab

  9. Neuroprotective effects of testosterone treatment in men with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Florian Kurth

    2014-01-01

    Full Text Available Multiple sclerosis (MS is an inflammatory and neurodegenerative disease of the central nervous system. While current medication reduces relapses and inflammatory activity, it has only a modest effect on long-term disability and gray matter atrophy. Here, we have characterized the potential neuroprotective effects of testosterone on cerebral gray matter in a pilot clinical trial. Ten men with relapsing–remitting MS were included in this open-label phase II trial. Subjects were observed without treatment for 6 months, followed by testosterone treatment for another 12 months. Focal gray matter loss as a marker for neurodegeneration was assessed using voxel-based morphometry. During the non-treatment phase, significant voxel-wise gray matter decreases were widespread (p≤ 0.05 corrected. However, during testosterone treatment, gray matter loss was no longer evident. In fact, a significant gray matter increase in the right frontal cortex was observed (p≤ 0.05 corrected. These observations support the potential of testosterone treatment to stall (and perhaps even reverse neurodegeneration associated with MS. Furthermore, they warrant the investigation of testosterone's neuroprotective effects in larger, placebo controlled MS trials as well as in other neurodegenerative diseases. This is the first report of gray matter increase as the result of treatment in MS.

  10. Feedback enhances the positive effects and reduces the negative effects of multiple-choice testing.

    Science.gov (United States)

    Butler, Andrew C; Roediger, Henry L

    2008-04-01

    Multiple-choice tests are used frequently in higher education without much consideration of the impact this form of assessment has on learning. Multiple-choice testing enhances retention of the material tested (the testing effect); however, unlike other tests, multiple-choice can also be detrimental because it exposes students to misinformation in the form of lures. The selection of lures can lead students to acquire false knowledge (Roediger & Marsh, 2005). The present research investigated whether feedback could be used to boost the positive effects and reduce the negative effects of multiple-choice testing. Subjects studied passages and then received a multiple-choice test with immediate feedback, delayed feedback, or no feedback. In comparison with the no-feedback condition, both immediate and delayed feedback increased the proportion of correct responses and reduced the proportion of intrusions (i.e., lure responses from the initial multiple-choice test) on a delayed cued recall test. Educators should provide feedback when using multiple-choice tests.

  11. Evaporation Kinetics of Laboratory Generated Secondary Organic Aerosols at Elevated Relative Humidity

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Jacqueline M.; Imre, D.; Beranek, Josef; Shrivastava, ManishKumar B.; Zelenyuk, Alla

    2015-01-06

    Secondary organic aerosols (SOA) dominate atmospheric organic aerosols that affect climate, air quality, and health. Recent studies indicate that, contrary to previously held assumptions, at low relative humidity (RH) these particles are semi-solid and evaporate orders of magnitude slower than expected. Elevated relative humidity has the potential to affect significantly formation, properties, and atmospheric evolution of SOA particles. Here we present a study of the effect of RH on the room-temperature evaporation kinetics of SOA particles formed by ozonolysis of α-pinene and limonene. Experiments were carried out on SOA particles generated, evaporated, and aged at 0%, 50% and 90% RH. We find that in all cases evaporation begins with a relatively fast phase, during which 30% to 70% of the particle mass evaporates in 2 hours, followed by a much slower evaporation rate. Evaporation kinetics at 0% and 50% RH are nearly the same, while at 90% RH a slightly larger fraction evaporates. In all cases, aging the particles prior to inducing evaporation reduces the evaporative losses, with aging at elevated RH leading to more significant effect. In all cases, SOA evaporation is nearly size-independent, providing direct evidence that oligomers play a crucial role in determining the evaporation kinetics.

  12. Lake Nasser evaporation reduction study

    Directory of Open Access Journals (Sweden)

    Hala M.I. Ebaid

    2010-10-01

    Full Text Available This study aims to evaluate the reduction of evaporation of Lake Nasser’s water caused by disconnecting (fully or partially some of its secondary channels (khors. This evaluation integrates remote sensing, Geographic Information System (GIS techniques, aerodynamic principles, and Landsat7 ETM+ images. Three main procedures were carried out in this study; the first derived the surface temperature from Landsat thermal band; the second derived evaporation depth and approximate evaporation volume for the entire lake, and quantified evaporation loss to the secondary channels’ level over one month (March by applied aerodynamic principles on surface temperature of the raster data; the third procedure applied GIS suitability analysis to determine which of these secondary channels (khors should be disconnected. The results showed evaporation depth ranging from 2.73 mm/day at the middle of the lake to 9.58 mm/day at the edge. The evaporated water-loss value throughout the entire lake was about 0.86 billion m3/month (March. The analysis suggests that it is possible to save an approximate total evaporation volume loss of 19.7 million m3/month (March, and thus 2.4 billion m3/year, by disconnecting two khors with approximate construction heights of 8 m and 15 m. In conclusion, remote sensing and GIS are useful for applications in remote locations where field-based information is not readily available and thus recommended for decision makers remotely planning in water conservation and management.

  13. Molecular Dynamics Simulations on Evaporation of Droplets with Dissolved Salts

    OpenAIRE

    Jin-Liang Xu; Min Chen; Xiao-Dong Wang; Bing-Bing Wang

    2013-01-01

    Molecular dynamics simulations are used to study the evaporation of water droplets containing either dissolved LiCl, NaCl or KCl salt in a gaseous surrounding (nitrogen) with a constant high temperature of 600 K. The initial droplet has 298 K temperature and contains 1,120 water molecules, 0, 40, 80 or 120 salt molecules. The effects of the salt type and concentration on the evaporation rate are examined. Three stages with different evaporation rates are observed for all cases. In the initial...

  14. Effects of an evaporative cooling system on plasma cortisol, IGF-I, and milk production in dairy cows in a tropical environment

    Science.gov (United States)

    Titto, Cristiane Gonçalves; Negrão, João Alberto; Titto, Evaldo Antonio Lencioni; Canaes, Taissa de Souza; Titto, Rafael Martins; Pereira, Alfredo Manuel Franco

    2013-03-01

    Access to an evaporative cooling system can increase production in dairy cows because of improved thermal comfort. This study aimed to evaluate the impact of ambient temperature on thermoregulation, plasma cortisol, insulin-like growth factor 1 (IGF-I), and productive status, and to determine the efficiency of an evaporative cooling system on physiological responses under different weather patterns. A total of 28 Holstein cows were divided into two groups, one with and the other without access to a cooling system with fans and mist in the free stall. The parameters were analyzed during morning (0700 hours) and afternoon milking (1430 hours) under five different weather patterns throughout the year (fall, winter, spring, dry summer, and rainy summer). Rectal temperature (RT), body surface temperature (BS), base of tail temperature (TT), and respiratory frequency (RF) were lower in the morning ( P milk production during spring and summer ( P < 0.01).

  15. Desalting of sea water by a wall-less evaporation process; Dessalement de l'eau de mer par un procede d'evaporation sans paroi

    Energy Technology Data Exchange (ETDEWEB)

    Kassel, C; Sachine, P; Vuillemey, R [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-06-01

    The need for fresh water supplies in many parts of the globe has given a great impetus to the study of the desalting of sea-water. Research into this problem has been very varied. Although it is possible in the more-or-less near future that methods based on freezing may be developed, only evaporation methods have industrial applications at the present time. Amongst the many techniques using this method, the most favorably placed installations from the technical and economic points of view are those based on multiple effects and wall-less heat transfer. We have defined the characteristics of a wall-less evaporation process using the various factors involved in this evaporation: energy source, corrosion, furring, heat transfer, maximum temperature, etc... The unit considered in this work has a daily output of 100,000 m{sup 3}, and makes use of the multi-stage technique with an organic heat-carrier. The maximum temperature of the first stage is 150 deg C and the evaporation factor is 0.4. After the description of the process and, the calculation of the equipment, an economic estimate is given of the cost-price : 1.49 F/m{sup 3}. It is likely that more detailed study of the process (technique, equipment and energy consumed) should make it possible to obtain a significant improvement in the process and to reduce the price to 1 F/m{sup 3}. (authors) [French] Le probleme de l 'approvisionnement en eau de nombreuses regions du globe a mis a 1'ordre du jour le dessalement de l'eau de mer. Des recherches sur cette question ont ete faites dans de multiples directions. Si dans un avenir plus ou moins proche les procedes par congelation peuvent se developper, actuellement seules les methodes d'evaporation ont des applications industrielles. Parmi les nombreuses techniques qui visent a mettre en oeuvre ce principe, les installations a multiples effets et transfert de chaleur sans paroi semblent les mieux placees du point de vue technique et economique. A partir des divers

  16. Desalting of sea water by a wall-less evaporation process; Dessalement de l'eau de mer par un procede d'evaporation sans paroi

    Energy Technology Data Exchange (ETDEWEB)

    Kassel, C.; Sachine, P.; Vuillemey, R. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-06-01

    The need for fresh water supplies in many parts of the globe has given a great impetus to the study of the desalting of sea-water. Research into this problem has been very varied. Although it is possible in the more-or-less near future that methods based on freezing may be developed, only evaporation methods have industrial applications at the present time. Amongst the many techniques using this method, the most favorably placed installations from the technical and economic points of view are those based on multiple effects and wall-less heat transfer. We have defined the characteristics of a wall-less evaporation process using the various factors involved in this evaporation: energy source, corrosion, furring, heat transfer, maximum temperature, etc... The unit considered in this work has a daily output of 100,000 m{sup 3}, and makes use of the multi-stage technique with an organic heat-carrier. The maximum temperature of the first stage is 150 deg C and the evaporation factor is 0.4. After the description of the process and, the calculation of the equipment, an economic estimate is given of the cost-price : 1.49 F/m{sup 3}. It is likely that more detailed study of the process (technique, equipment and energy consumed) should make it possible to obtain a significant improvement in the process and to reduce the price to 1 F/m{sup 3}. (authors) [French] Le probleme de l 'approvisionnement en eau de nombreuses regions du globe a mis a 1'ordre du jour le dessalement de l'eau de mer. Des recherches sur cette question ont ete faites dans de multiples directions. Si dans un avenir plus ou moins proche les procedes par congelation peuvent se developper, actuellement seules les methodes d'evaporation ont des applications industrielles. Parmi les nombreuses techniques qui visent a mettre en oeuvre ce principe, les installations a multiples effets et transfert de chaleur sans paroi semblent les mieux placees du point de vue technique et economique. A

  17. Effect of thermal annealing on structural properties of SrGa2S4:Ce thin films prepared by flash evaporation

    International Nuclear Information System (INIS)

    Gambarov, E.F.; Bayramov, A.I.

    2009-01-01

    In the present report the preparation technology and structural characterization of Ce 3 +activated SrGa 2 S 4 thin films are given. SrGa 2 S 4 : e thin films are prepared by so called flash evaporation which is simple and inexpensive method for thin film deposition. X-ray diffraction shows that the as deposited films exhibit amorphous behavior, but after annealing in H S stream, the polycrystalline one. EPMA results indicate nearly stoichiometric composition of the thin films

  18. Effect of Advanced Plasma Source bias voltage on properties of HfO2 films prepared by plasma ion assisted electron evaporation from metal hafnium

    International Nuclear Information System (INIS)

    Zhu, Meiping; Yi, Kui; Arhilger, Detlef; Qi, Hongji; Shao, Jianda

    2013-01-01

    HfO 2 films, using metal hafnium as starting material, are deposited by plasma-ion assisted electron evaporation with different Advanced Plasma Source (APS) bias voltages. The refractive index and extinction coefficient are calculated, the chemical state and composition, as well as the stress and aging behavior is investigated. Laser induced damage threshold (LIDT) and damage mechanism are also evaluated and discussed. Optical, structural, mechanical and laser induced damage properties of HfO 2 films are found to be sensitive to APS bias voltage. The film stress can be tuned by varying the APS bias voltage. Damage morphologies indicate the LIDT of the HfO 2 films at 1064 nm and 532 nm are dominated by the nodular-defect density in coatings, while the 355 nm LIDT is dominated by the film absorption. HfO 2 films with higher 1064 nm LIDT than samples evaporated from hafnia are achieved with bias voltage of 100 V. - Highlights: • HfO 2 films are evaporated with different Advanced Plasma Source (APS) bias voltages. • Properties of HfO 2 films are sensitive to APS bias voltage. • With a bias voltage of 100 V, HfO 2 coatings without any stress can be achieved. • Higher 1064 nm laser induced damage threshold is achieved at a bias voltage of 100 V

  19. Evaporation behaviour of different organic effluents from open surfaces.

    Science.gov (United States)

    Jhorar, B S; Malik, R S

    1993-01-01

    Production of large quantities of effluents from different industrial units and the problems of their disposal necessitated this evaporation study. The evaporation of water, sewage water, oil refinery effluent, papermill effluent and liquor distillery effluent was observed in glass beakers when placed (i) in an oven at 60 degrees C and (ii) in screen house for 30 days, by periodically weighing of the beakers. In other experiments, the effect of increasing the frequency of stirring on increasing the evaporation efficiency of the liquor distillery effluent (ELD) was examined in detail. All of the organic effluents except ELD had similar evaporation behaviours as water, but formation of a self-forming film caused the evaporation of ELD to be considerably lower. Resistance to evaporation caused by this film was found to be a decreasing function of the frequency of stirring. This study has a bearing on improving the efficiency of evaporation lagoons, and three stirrings in a day with a manually drawn stirrer in a full-scale lagoon are proposed as a practical and economically viable technique to save 44% of lagoon land in arid and semi-arid regions of the world.

  20. Humidity-insensitive water evaporation from molecular complex fluids.

    Science.gov (United States)

    Salmon, Jean-Baptiste; Doumenc, Frédéric; Guerrier, Béatrice

    2017-09-01

    We investigated theoretically water evaporation from concentrated supramolecular mixtures, such as solutions of polymers or amphiphilic molecules, using numerical resolutions of a one-dimensional model based on mass transport equations. Solvent evaporation leads to the formation of a concentrated solute layer at the drying interface, which slows down evaporation in a long-time-scale regime. In this regime, often referred to as the falling rate period, evaporation is dominated by diffusive mass transport within the solution, as already known. However, we demonstrate that, in this regime, the rate of evaporation does not also depend on the ambient humidity for many molecular complex fluids. Using analytical solutions in some limiting cases, we first demonstrate that a sharp decrease of the water chemical activity at high solute concentration leads to evaporation rates which depend weakly on the humidity, as the solute concentration at the drying interface slightly depends on the humidity. However, we also show that a strong decrease of the mutual diffusion coefficient of the solution enhances considerably this effect, leading to nearly independent evaporation rates over a wide range of humidity. The decrease of the mutual diffusion coefficient indeed induces strong concentration gradients at the drying interface, which shield the concentration profiles from humidity variations, except in a very thin region close to the drying interface.

  1. Diffusion of multiple species with excluded-volume effects

    KAUST Repository

    Bruna, Maria; Chapman, S. Jonathan

    2012-01-01

    Stochastic models of diffusion with excluded-volume effects are used to model many biological and physical systems at a discrete level. The average properties of the population may be described by a continuum model based on partial differential equations. In this paper we consider multiple interacting subpopulations/species and study how the inter-species competition emerges at the population level. Each individual is described as a finite-size hard core interacting particle undergoing Brownian motion. The link between the discrete stochastic equations of motion and the continuum model is considered systematically using the method of matched asymptotic expansions. The system for two species leads to a nonlinear cross-diffusion system for each subpopulation, which captures the enhancement of the effective diffusion rate due to excluded-volume interactions between particles of the same species, and the diminishment due to particles of the other species. This model can explain two alternative notions of the diffusion coefficient that are often confounded, namely collective diffusion and self-diffusion. Simulations of the discrete system show good agreement with the analytic results. © 2012 American Institute of Physics.

  2. Curcumin mediates anticancer effects by modulating multiple cell signaling pathways.

    Science.gov (United States)

    Kunnumakkara, Ajaikumar B; Bordoloi, Devivasha; Harsha, Choudhary; Banik, Kishore; Gupta, Subash C; Aggarwal, Bharat B

    2017-08-01

    Curcumin, a component of a spice native to India, was first isolated in 1815 by Vogel and Pelletier from the rhizomes of Curcuma longa (turmeric) and, subsequently, the chemical structure of curcumin as diferuloylmethane was reported by Milobedzka et al. [(1910) 43., 2163-2170]. Since then, this polyphenol has been shown to exhibit antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antifungal activities. The current review primarily focuses on the anticancer potential of curcumin through the modulation of multiple cell signaling pathways. Curcumin modulates diverse transcription factors, inflammatory cytokines, enzymes, kinases, growth factors, receptors, and various other proteins with an affinity ranging from the pM to the mM range. Furthermore, curcumin effectively regulates tumor cell growth via modulation of numerous cell signaling pathways and potentiates the effect of chemotherapeutic agents and radiation against cancer. Curcumin can interact with most of the targets that are modulated by FDA-approved drugs for cancer therapy. The focus of this review is to discuss the molecular basis for the anticancer activities of curcumin based on preclinical and clinical findings. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  3. Curcumin analog L3 alleviates diabetic atherosclerosis by multiple effects.

    Science.gov (United States)

    Zheng, Bin; Yang, Liu; Wen, Caixia; Huang, Xiuwang; Xu, Chenxia; Lee, Kuan-Han; Xu, Jianhua

    2016-03-15

    L3, an analog of curcumin, is a compound isolated from a traditional Chinese medicine Turmeric. In this paper, we aims to explore the efficacy of L3 on diabetic atherosclerosis and the related mechanism. The effect of L3 was studied on glucose and lipid metabolism, antioxidant status, atherosclerosis-related indexes and pathological changes of main organs in the mice model of diabetes induced by streptozotocin and high-fat diet. The results showed that L3 treatment could meliorate dyslipidemia and hyperglycemia, reduce oxidative stress, enhance the activity of antioxidases, increase the nitric oxide level in plasma and aortic arch, decrease the production of reactive oxygen species in pancreas and lectin-like oxidized low-density lipoprotein receptor-1 expression in aortic arch, and meliorate the fatty and atherosclerotic degeneration in aortic arch, thereby preventing the development of diabetes and its complications. These results suggested that L3 can alleviate the diabetic atherosclerosis by multiple effects. This study provided scientific basis for the further research and clinical application of L3. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Enhancing Water Evaporation with Floating Synthetic Leaves

    Science.gov (United States)

    Boreyko, Jonathan; Vieitez, Joshua; Berrier, Austin; Roseveare, Matthew; Shi, Weiwei

    2017-11-01

    When a wetted nanoporous medium is exposed to a subsaturated ambient environment, the water menisci assume a concave curvature to achieve a negative pressure. This negative water pressure is required to balance the mismatch in water activity across the water-air interface to achieve local equilibrium. Here, we show that the diffusive evaporation rate of water can be greatly modulated by floating a nanoporous synthetic leaf at the water's free interface. For high ambient humidities, adding the leaf serves to enhance the evaporation rate, presumably by virtue of the menisci enhancing the effective liquid-vapor surface area. For low humidities, the menisci cannot achieve a local equilibrium and retreat partway into the leaf, which increases the local humidity directly above the menisci. In light of these two effects, we find the surprising result that leaves exposed to an ambient humidity of 90 percent can evaporate water at the same rate as leaves exposed to only 50 percent humidity. These findings have implications for using synthetic trees to enhance steam generation or water harvesting. This work was supported by the National Science Foundation (CBET-1653631).

  5. Grandparental effects in marine sticklebacks: transgenerational plasticity across multiple generations.

    Science.gov (United States)

    Shama, L N S; Wegner, K M

    2014-11-01

    Nongenetic inheritance mechanisms such as transgenerational plasticity (TGP) can buffer populations against rapid environmental change such as ocean warming. Yet, little is known about how long these effects persist and whether they are cumulative over generations. Here, we tested for adaptive TGP in response to simulated ocean warming across parental and grandparental generations of marine sticklebacks. Grandparents were acclimated for two months during reproductive conditioning, whereas parents experienced developmental acclimation, allowing us to compare the fitness consequences of short-term vs. prolonged exposure to elevated temperature across multiple generations. We found that reproductive output of F1 adults was primarily determined by maternal developmental temperature, but carry-over effects from grandparental acclimation environments resulted in cumulative negative effects of elevated temperature on hatching success. In very early stages of growth, F2 offspring reached larger sizes in their respective paternal and grandparental environment down the paternal line, suggesting that other factors than just the paternal genome may be transferred between generations. In later growth stages, maternal and maternal granddam environments strongly influenced offspring body size, but in opposing directions, indicating that the mechanism(s) underlying the transfer of environmental information may have differed between acute and developmental acclimation experienced by the two generations. Taken together, our results suggest that the fitness consequences of parental and grandparental TGP are highly context dependent, but will play an important role in mediating some of the impacts of rapid climate change in this system. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  6. Mathematical modelling and simulation of the operation in sugar and alcohol industry: 2 - evaporation; Modelagem matematica e simulacao das operacoes da industria de acucar e alcool: 2 - evaporacao

    Energy Technology Data Exchange (ETDEWEB)

    Chiappetta, A; Giudici, R; Nascimento, C A.O. do [Sao Paulo Univ., SP (Brazil). Escola Politecnica

    1987-12-31

    A mathematical model is presented for steady-state simulation of multiple-effects evaporators systems used for concentration of sugar solution. The model basis are the fundamental energy and mass balances equations, as well as empirical correlations for the problem being handled. The evaporation system simulation is performed with an executive program which allows different process configurations. For one typical case, some process parameters (volumetric rate and concentration of feed;exhaust steam temperature) influences on syrup concentration and solution temperature were studied. (author) 8 figs., 2 refs.

  7. Evaporative behavior of carbon with MPD Arc Jet

    Energy Technology Data Exchange (ETDEWEB)

    Sukegawa, Toshio; Madarame, Haruki; Okamoto, Koji [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1996-10-01

    Using the Magneto-Plasma-Dynamic Arc Jet (MPD Arc Jet) device, the plasma-material interaction during simulated plasma disruption was experimentally investigated. To clarify the effects of the evaporation, the isotropic graphite was used as a target. The thermal conductivity of the isotropic graphite was much higher than that of the pyrolytic graphite, resulting in smaller evaporation. The light intensity distribution during the simulated disruption for the isotropic graphite was quite different from that for the pyrolytic graphite. (author)

  8. Spacetime structure of an evaporating black hole in quantum gravity

    International Nuclear Information System (INIS)

    Bonanno, A.; Reuter, M.

    2006-01-01

    The impact of the leading quantum gravity effects on the dynamics of the Hawking evaporation process of a black hole is investigated. Its spacetime structure is described by a renormalization group improved Vaidya metric. Its event horizon, apparent horizon, and timelike limit surface are obtained by taking the scale dependence of Newton's constant into account. The emergence of a quantum ergosphere is discussed. The final state of the evaporation process is a cold, Planck size remnant

  9. (Anti-)Evaporation of Schwarzschild-de Sitter Black Holes

    OpenAIRE

    Bousso, Raphael; Hawking, Stephen

    1997-01-01

    We study the quantum evolution of black holes immersed in a de Sitter background space. For black holes whose size is comparable to that of the cosmological horizon, this process differs significantly from the evaporation of asymptotically flat black holes. Our model includes the one-loop effective action in the s-wave and large N approximation. Black holes of the maximal mass are in equilibrium. Unexpectedly, we find that nearly maximal quantum Schwarzschild-de Sitter black holes anti-evapor...

  10. Influence of surface wettability on transport mechanisms governing water droplet evaporation.

    Science.gov (United States)

    Pan, Zhenhai; Weibel, Justin A; Garimella, Suresh V

    2014-08-19

    Prediction and manipulation of the evaporation of small droplets is a fundamental problem with importance in a variety of microfluidic, microfabrication, and biomedical applications. A vapor-diffusion-based model has been widely employed to predict the interfacial evaporation rate; however, its scope of applicability is limited due to incorporation of a number of simplifying assumptions of the physical behavior. Two key transport mechanisms besides vapor diffusion-evaporative cooling and natural convection in the surrounding gas-are investigated here as a function of the substrate wettability using an augmented droplet evaporation model. Three regimes are distinguished by the instantaneous contact angle (CA). In Regime I (CA ≲ 60°), the flat droplet shape results in a small thermal resistance between the liquid-vapor interface and substrate, which mitigates the effect of evaporative cooling; upward gas-phase natural convection enhances evaporation. In Regime II (60 ≲ CA ≲ 90°), evaporative cooling at the interface suppresses evaporation with increasing contact angle and counterbalances the gas-phase convection enhancement. Because effects of the evaporative cooling and gas-phase convection mechanisms largely neutralize each other, the vapor-diffusion-based model can predict the overall evaporation rates in this regime. In Regime III (CA ≳ 90°), evaporative cooling suppresses the evaporation rate significantly and reverses entirely the direction of natural convection induced by vapor concentration gradients in the gas phase. Delineation of these counteracting mechanisms reconciles previous debate (founded on single-surface experiments or models that consider only a subset of the governing transport mechanisms) regarding the applicability of the classic vapor-diffusion model. The vapor diffusion-based model cannot predict the local evaporation flux along the interface for high contact angle (CA ≥ 90°) when evaporative cooling is strong and the

  11. EFFECTIVE INDICES FOR MONITORING MENTAL WORKLOAD WHILE PERFORMING MULTIPLE TASKS.

    Science.gov (United States)

    Hsu, Bin-Wei; Wang, Mao-Jiun J; Chen, Chi-Yuan; Chen, Fang

    2015-08-01

    This study identified several physiological indices that can accurately monitor mental workload while participants performed multiple tasks with the strategy of maintaining stable performance and maximizing accuracy. Thirty male participants completed three 10-min. simulated multitasks: MATB (Multi-Attribute Task Battery) with three workload levels. Twenty-five commonly used mental workload measures were collected, including heart rate, 12 HRV (heart rate variability), 10 EEG (electroencephalography) indices (α, β, θ, α/θ, θ/β from O1-O2 and F4-C4), and two subjective measures. Analyses of index sensitivity showed that two EEG indices, θ and α/θ (F4-C4), one time-domain HRV-SDNN (standard deviation of inter-beat intervals), and four frequency-domain HRV: VLF (very low frequency), LF (low frequency), %HF (percentage of high frequency), and LF/HF were sensitive to differentiate high workload. EEG α/θ (F4-C4) and LF/HF were most effective for monitoring high mental workload. LF/HF showed the highest correlations with other physiological indices. EEG α/θ (F4-C4) showed strong correlations with subjective measures across different mental workload levels. Operation strategy would affect the sensitivity of EEG α (F4-C4) and HF.

  12. Sensitivity analysis in multiple imputation in effectiveness studies of psychotherapy.

    Science.gov (United States)

    Crameri, Aureliano; von Wyl, Agnes; Koemeda, Margit; Schulthess, Peter; Tschuschke, Volker

    2015-01-01

    The importance of preventing and treating incomplete data in effectiveness studies is nowadays emphasized. However, most of the publications focus on randomized clinical trials (RCT). One flexible technique for statistical inference with missing data is multiple imputation (MI). Since methods such as MI rely on the assumption of missing data being at random (MAR), a sensitivity analysis for testing the robustness against departures from this assumption is required. In this paper we present a sensitivity analysis technique based on posterior predictive checking, which takes into consideration the concept of clinical significance used in the evaluation of intra-individual changes. We demonstrate the possibilities this technique can offer with the example of irregular longitudinal data collected with the Outcome Questionnaire-45 (OQ-45) and the Helping Alliance Questionnaire (HAQ) in a sample of 260 outpatients. The sensitivity analysis can be used to (1) quantify the degree of bias introduced by missing not at random data (MNAR) in a worst reasonable case scenario, (2) compare the performance of different analysis methods for dealing with missing data, or (3) detect the influence of possible violations to the model assumptions (e.g., lack of normality). Moreover, our analysis showed that ratings from the patient's and therapist's version of the HAQ could significantly improve the predictive value of the routine outcome monitoring based on the OQ-45. Since analysis dropouts always occur, repeated measurements with the OQ-45 and the HAQ analyzed with MI are useful to improve the accuracy of outcome estimates in quality assurance assessments and non-randomized effectiveness studies in the field of outpatient psychotherapy.

  13. Effect of thermohydraulic parameter on the flux distribution and the effective multiplication factor

    International Nuclear Information System (INIS)

    Mello, J.C.; Valladares, G.L.

    1990-01-01

    The influence of two thermohydraulics parameters; the coolant flow velocity along the reactor channels and the increase of the average water temperature through the core, on the thermal flux distribution and on the effective multiplication factor, was studied in a radioisotopes production reactor. The results show that, for a fixed values of the thermohydraulics parameters reffered above, there are limits for the reactor core volume reduction for each value of the V sub(mod)/V sub(comb) ratio. These thermohydraulics conditions determine the higher termal flux value in the flux-trap and the lower value of the reactor effective multiplication factor. It is also show that there is a V sub(mod)/V sub(comb) ratio value that correspond to the higher value of the lower effective multiplication factor. These results was interpreted and comment using fundamentals concepts and relations of reactor physics. (author)

  14. Effect of 12-Week Pilates Trainning on EDSS in Women Suffering fromMultiple Sclerosis

    OpenAIRE

    Z Shanazari; SM Marandi; S Samie

    2013-01-01

    Abstract Background & aim: Multiple sclerosis is a debilitating disease that strikes the immune system. Multiple sclerosis is a chronic disease which debilitates the nervous system. The study was evaluated the effects of Pilates exercise on women with physical disabilities suffering from multiple sclerosis for 12 weeks .The aim of this study was to investigating the effects of Pilates trainning on EDSS of women suffering from Multiple Sclerosis (MS) for 12 weeks. Methods: In the pres...

  15. Performance of solar still with a concave wick evaporation surface

    Energy Technology Data Exchange (ETDEWEB)

    Kabeel, A.E. [Mechanical Power Department, Faculty of Engineering, Tanta University (Egypt)

    2009-10-15

    Surfaces used for evaporation and condensation phenomenon play important roles in the performance of basin type solar still. In the present study, a concave wick surface was used for evaporation, whereas four sides of a pyramid shaped still were used for condensation. Use of jute wick increased the amount of absorbed solar radiation and enhanced the evaporation surface area. A concave shaped wick surface increases the evaporation area due to the capillary effect. Results show that average distillate productivity in day time was 4.1 l/m{sup 2} and a maximum instantaneous system efficiency of 45% and average daily efficiency of 30% were recorded. The maximum hourly yield was 0.5 l/h. m{sup 2} after solar noon. An estimated cost of 1l of distillate was 0.065 $ for the presented solar still. (author)

  16. Performance of solar still with a concave wick evaporation surface

    International Nuclear Information System (INIS)

    Kabeel, A.E.

    2009-01-01

    Surfaces used for evaporation and condensation phenomenon play important roles in the performance of basin type solar still. In the present study, a concave wick surface was used for evaporation, whereas four sides of a pyramid shaped still were used for condensation. Use of jute wick increased the amount of absorbed solar radiation and enhanced the evaporation surface area. A concave shaped wick surface increases the evaporation area due to the capillary effect. Results show that average distillate productivity in day time was 4.1 l/m 2 and a maximum instantaneous system efficiency of 45% and average daily efficiency of 30% were recorded. The maximum hourly yield was 0.5 l/h. m 2 after solar noon. An estimated cost of 1 l of distillate was 0.065 $ for the presented solar still.

  17. Evaporation residue excitation function measurement for 19F + 194,198Pt reactions

    International Nuclear Information System (INIS)

    Singh, Varinderjit; Behera, B.R.; Kaur, Maninder

    2012-01-01

    Nuclear dissipation is one of the active fields in the present day nuclear physics research. Experimental signatures for dissipation are observed through large excess in pre-fission neutrons, γ-ray multiplicities from the compound nucleus, giant dipole resonance (GDR) γ-rays, light charged particles and evaporation residues in comparison to standard statistical model, for the heavy-ion induced fusion-fission or fusion-evaporation reactions (ERs). From the analysis of a large set of experimental data, it is well established that there exists a large dissipation at nuclear temperature above 1 MeV. But most of these probes are not sensitive to the dissipation within saddle. The ER cross-section is a probe which is sensitive to dissipation within the saddle point. Hence, the study of ER cross-section can be helpful in estimating the dissipation effects inside the saddle point. Also the other motivation for these measurements is to see the effect of shell closure on dissipation. With this motivation the evaporation cross-sections for 19 F + 194,198 Pt are measured at beam energy of 101 to 137.3 MeV. Of the above systems 19 F + 194 Pt populates 213 Fr (N = 126) shell closed compound nucleus (CN) whereas, other system populate 217 Fr (N = 130) non-shell closed CN

  18. Effect of argon gas flow rate on properties of film electrodes prepared by thermal vacuum evaporation from synthesized Cu{sub 2}SnSe{sub 3} source

    Energy Technology Data Exchange (ETDEWEB)

    Sabli, Nordin; Talib, Zainal Abidin; Yunus, Wan Mahmood Mat [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang (Malaysia); Zainal, Zulkarnain [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang (Malaysia); Hilal, Hikmat S. [SSERL, Department of Chemistry An-Najah N. University, PO Box 7, Nablus, West Bank (Country Unknown); Fujii, Masatoshi [Department of Molecular Science, School of Medicine, Shimane University, Izumo, Shimane, 693-8501 (Japan)

    2014-03-05

    This work describes a new technique to enhance photoresponse of metal chalcogenide-based semiconductor film electrodes deposited by thermal vacuum evaporation under argon gas flow from synthesized Cu{sub 2}SnSe{sub 3} sources. SnSe formation with Cu-doped was obtained under higher argon gas flow rate (V{sub A} = 25 cm{sup 3}/min). Higher value of photoresponse was observed for films deposited under V{sub A} = 25 cm{sup 3}/min which was 9.1%. This finding indicates that Cu atoms inside the SnSe film were important to increase carrier concentrations that promote higher photoresponse.

  19. Effects of nearshore evaporation rates on the design of seabed gallery intake systems for SWRO facilities located along the Red Sea shoreline of Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah

    2015-10-12

    Feed water to seawater reverse osmosis desalination systems should have a constant salinity with minimal variation. Intake systems that extract water from shallow nearshore areas in arid regions can exhibit significant fluctuations in salinity caused by high rates of evaporation and lack of circulation. Such fluctuations in salinity could inhibit the design, construction, and operation of seabed gallery intake systems located in shallow nearshore areas, such as the Red Sea inner shelf. Water depths range from 0 to 2 m between the beach and the edge of the fringing reef in the optimal locations for the development of seabed gallery intakes along the coast of the Red Sea of Saudi Arabia. The evaporation rate in this area is between 2 and 3 m per year. The bottom consists of mostly a marine hardground containing a thin veneer of unlithified sediment and no significant cover of corals or seagrass. The rather barren nature of the bottom suggests that periodic hypersalinity may contribute to the formation of hardgrounds on the bottom by causing supersaturation of the seawater with calcium carbonate and may limit the growth of corals and grasses. To assess the changes in salinity, a conceptual model was developed which assumes that a shallow circulation cell develops between the shoreline and deeper water offshore. Lower salinity seawater should migrate landward to replace water loss caused by evaporation with seaward moving of high-salinity water occurring along the bottom to balance the flow with ultimate mixing before the reef tract. To test this circulation pattern, a series of sensors were deployed to continuously monitor the water temperature, conductivity, and salinity at the surface and at the bottom during several periods of high air temperature. Surprisingly, the results show very little variation in salinity, despite the very high evaporation loss. The water salinity ranged between 39,000 and 40,000 mg/L with no diurnal variations of significance. Based on the

  20. Assessment of water droplet evaporation mechanisms on hydrophobic and superhydrophobic substrates.

    Science.gov (United States)

    Pan, Zhenhai; Dash, Susmita; Weibel, Justin A; Garimella, Suresh V

    2013-12-23

    Evaporation rates are predicted and important transport mechanisms identified for evaporation of water droplets on hydrophobic (contact angle ~110°) and superhydrophobic (contact angle ~160°) substrates. Analytical models for droplet evaporation in the literature are usually simplified to include only vapor diffusion in the gas domain, and the system is assumed to be isothermal. In the comprehensive model developed in this study, evaporative cooling of the interface is accounted for, and vapor concentration is coupled to local temperature at the interface. Conjugate heat and mass transfer are solved in the solid substrate, liquid droplet, and surrounding gas. Buoyancy-driven convective flows in the droplet and vapor domains are also simulated. The influences of evaporative cooling and convection on the evaporation characteristics are determined quantitatively. The liquid-vapor interface temperature drop induced by evaporative cooling suppresses evaporation, while gas-phase natural convection acts to enhance evaporation. While the effects of these competing transport mechanisms are observed to counterbalance for evaporation on a hydrophobic surface, the stronger influence of evaporative cooling on a superhydrophobic surface accounts for an overprediction of experimental evaporation rates by ~20% with vapor diffusion-based models. The local evaporation fluxes along the liquid-vapor interface for both hydrophobic and superhydrophobic substrates are investigated. The highest local evaporation flux occurs at the three-phase contact line region due to proximity to the higher temperature substrate, rather than at the relatively colder droplet top; vapor diffusion-based models predict the opposite. The numerically calculated evaporation rates agree with experimental results to within 2% for superhydrophobic substrates and 3% for hydrophobic substrates. The large deviations between past analytical models and the experimental data are therefore reconciled with the

  1. Evaporative cycles - in theory and in practise

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, P.M.

    2000-08-01

    The thesis is based on applied research, rather closed to industrial development. The developed simulation model, for pre-design of evaporative gas turbine cycles, has been validated in a 600 kW pilot plant and in rebuilt turbo-charged diesel engines. Besides of the work with the thesis including theoretical modelling and hardware development concerning wet cycles, the work has also resulted in three patents dealing with the technique studied. The main feature of the evaporative cycles is the way the integration between the gas and liquid flows is executed, combined with using low-level heat gathered into the liquid phase which is later used to evaporate the liquid itself in a humidification tower. In this tower, the mass- and heat transfer take place under stable physical laws, and if the tower is properly designed, the distilling effect in the tower will also be high. Today the combined cycle has the best thermal efficiency to generate electricity from fuels. Every new power cycle, including the evaporative cycles, will therefore be compared with power stations based on combined cycles. In evaporative cycles, the steam bottoming cycle of the combined cycles has been eliminated. Instead the 'steam' cycle is integrated into the gas cycle. This action has a favourable effect on thermal efficiency and on NO{sub x} formation in the combustion zone. The major part of this thesis is about the EvGT-project. At Lund University, the major objective of this project was to develop, design, erect and operate the world's first evaporative gas turbine unit. The objective was accomplished in 1999, and in the process of reaching the objective, rather large modelling errors, both thermodynamic and dimensioning of the humidification tower, have been detected in the open literature. It seems as if the pressure dependency of the humidification process has been underestimated in the models used today. The EvGT-pilot plant at Lund University was built and taken into

  2. The sustainability of LNG evaporation

    NARCIS (Netherlands)

    Stougie, L.; Van der Kooi, H.J.

    2011-01-01

    Numerous LNG (Liquefied Natural Gas) import terminals are under construction to fulfil the growing demand for energy carriers. After storage in tanks, the LNG needs to be heated and evaporated, also called ‘regasified’, to the natural gas needed in households and industry. Several options exist for

  3. Evaporation in relation to hydrology

    NARCIS (Netherlands)

    Wartena, L.; Keijman, J.Q.; Bruijn, H.A.R. de; Bakel, P.J.T. van; Stricker, J.N.M.; Velds, C.A.

    1981-01-01

    In meteorology some topics enjoy particular interest from other disciplines. The interest of hydrologists for the evaporation of water is a case in point, understandably and rightly so. In fact, over the last few decades, hydrology has clearly done more than using meteorological knowledge thus

  4. Micro-evaporation electrolyte concentrator

    NARCIS (Netherlands)

    Timmer, B.H.; van Delft, K.M.; Olthuis, Wouter; Bergveld, Piet; van den Berg, Albert

    2003-01-01

    The sensitivity of miniaturized chemical analysis systems depends most of the time on the obtainable detection limit. Concentrating the analyte prior to the detection system can enhance the detection limit. In this writing an analyte concentrator is presented that makes use of evaporation to

  5. Multiple Effects of Messages with Multiple Goals: Some Perceived Outcomes of Responses to Sexual Harassment.

    Science.gov (United States)

    Bingham, Shereen G.; Burleson, Brant R.

    1989-01-01

    Tests the perceived effectiveness of different messages responding to sexual harassment in the organizational environment. Finds that none of the messages were perceived as being particularly effective at stopping the harasser's offensive conduct. (MM)

  6. Effects of Acupuncture on Gait of Patients with Multiple Sclerosis.

    Science.gov (United States)

    Criado, Maria Begoña; Santos, Maria João; Machado, Jorge; Gonçalves, Arminda Manuela; Greten, Henry Johannes

    2017-11-01

    Multiple sclerosis is considered a complex and heterogeneous disease. Approximately 85% of patients with multiple sclerosis indicate impaired gait as one of the major limitations in their daily life. Acupuncture studies found a reduction of spasticity and improvement of fatigue and imbalance in patients with multiple sclerosis, but there is a lack of studies regarding gait. We designed a study of acupuncture treatment, according to the Heidelberg model of Traditional Chinese Medicine (TCM), to investigate if acupuncture can be a useful therapeutic strategy in patients with gait impairment in multiple sclerosis of relapsing-remitting type. The sample consisted of 20 individuals with diagnosis of multiple sclerosis of relapsing-remitting type. Gait impairment was evaluated by the 25-foot walk test. The results showed differences in time to walk 25 feet following true acupuncture. In contrast, there was no difference in time to walk 25 feet following sham acupuncture. When using true acupuncture, 95% of cases showed an improvement in 25-foot walk test, compared with 45% when sham acupuncture was done. Our study protocol provides evidence that acupuncture treatment can be an attractive option for patients with multiple sclerosis, with gait impairment.

  7. NWCF Evaporator Tank System 2001 Offgas Emissions Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, Richard Doin; Lamb, Kenneth Mitchel; Matejka, Leon Anthony; Nenni, Joseph A

    2002-02-01

    An offgas emissions inventory and liquid stream characterization of the Idaho New Waste Calcining Facility (NWCF) Evaporator Tank System (ETS), formerly known as the High Level Liquid Waste Evaporator (HLLWE), has been completed. The emissions rates of volatile and semi-volatile organic compounds, multiple metals, particulate, and hydrochloric acid were measured in accordance with an approved Quality Assurance Project Plan (QAPjP) and Test Plan that invoked U.S. Environmental Protection Agency (EPA) standard sample collection and analysis procedures. Offgas samples were collected during the start up and at the end of evaporator batches when it was hypothesized the emissions would be at peak rates. Corresponding collection of samples from the evaporator feed overhead condensate, and bottoms was made at approximately the same time as the emissions inventory to support material balance determinations for the evaporator process. The data indicate that organic compound emissions are slightly higher at the beginning of the batch while metals emissions, including mercury, are slightly higher at the end of the evaporator batch. The maximum emissions concentrations are low for all constituents of primary concern. Mercury emissions were less than 5 ppbv, while the sum of HCl and Cl2 emissions was less than 1 ppmv. The sum of all organic emissions also was less than 1 ppmv. The estimated hazardous quotient (HQ) for the evaporator was 6.2e-6 as compared to 0.25 for the EPA target criteria. The cancer risk was 1.3e-10 compared to an EPA target of le-5.

  8. NWCF Evaporator Tank System 2001 Offgas Emissions Inventory; ANNUAL

    International Nuclear Information System (INIS)

    Boardman, R.D.; Lamb, K.M.; Matejka, L.A.; Nenni, J.A.

    2002-01-01

    An offgas emissions inventory and liquid stream characterization of the Idaho New Waste Calcining Facility (NWCF) Evaporator Tank System (ETS), formerly known as the High Level Liquid Waste Evaporator (HLLWE), has been completed. The emissions rates of volatile and semi-volatile organic compounds, multiple metals, particulate, and hydrochloric acid were measured in accordance with an approved Quality Assurance Project Plan (QAPjP) and Test Plan that invoked U.S. Environmental Protection Agency (EPA) standard sample collection and analysis procedures. Offgas samples were collected during the start up and at the end of evaporator batches when it was hypothesized the emissions would be at peak rates. Corresponding collection of samples from the evaporator feed overhead condensate, and bottoms was made at approximately the same time as the emissions inventory to support material balance determinations for the evaporator process. The data indicate that organic compound emissions are slightly higher at the beginning of the batch while metals emissions, including mercury, are slightly higher at the end of the evaporator batch. The maximum emissions concentrations are low for all constituents of primary concern. Mercury emissions were less than 5 ppbv, while the sum of HCl and Cl2 emissions was less than 1 ppmv. The sum of all organic emissions also was less than 1 ppmv. The estimated hazardous quotient (HQ) for the evaporator was 6.2e-6 as compared to 0.25 for the EPA target criteria. The cancer risk was 1.3e-10 compared to an EPA target of le-5

  9. NWCF Evaporator Tank System 2001 Offgas Emissions Inventory

    International Nuclear Information System (INIS)

    Boardman, R.D.; Lamb, K.M.; Matejka, L.A.; Nenni, J.A.

    2002-01-01

    An offgas emissions inventory and liquid stream characterization of the Idaho New Waste Calcining Facility (NWCF) Evaporator Tank System (ETS), formerly known as the High Level Liquid Waste Evaporator (HLLWE), has been completed. The emissions rates of volatile and semi-volatile organic compounds, multiple metals, particulate, and hydrochloric acid were measured in accordance with an approved Quality Assurance Project Plan (QAPjP) and Test Plan that invoked U.S. Environmental Protection Agency (EPA) standard sample collection and analysis procedures. Offgas samples were collected during the start up and at the end of evaporator batches when it was hypothesized the emissions would be at peak rates. Corresponding collection of samples from the evaporator feed overhead condensate, and bottoms was made at approximately the same time as the emissions inventory to support material balance determinations for the evaporator process. The data indicate that organic compound emissions are slightly higher at the beginning of the batch while metals emissions, including mercury, are slightly higher at the end of the evaporator batch. The maximum emissions concentrations are low for all constituents of primary concern. Mercury emissions were less than 5 ppbv, while the sum of HCl and Cl2 emissions was less than 1 ppmv. The sum of all organic emissions also was less than 1 ppmv. The estimated hazardous quotient (HQ) for the evaporator was 6.2e-6 as compared to 0.25 for the EPA target criteria. The cancer risk was 1.3e-10 compared to an EPA target of le-5

  10. [Multiple sclerosis: socioeconomic effects and impact on quality of life].

    Science.gov (United States)

    Ayuso, Guillermo Izquierdo

    2014-12-01

    Multiple sclerosis (MS) is a disease of the central nervous system (CNS) that affects young adults. Survival is long, more than 35 years, and consequently the disease has a huge socioeconomic impact. The present article discusses the enormous difficulties of carrying out economic assessments in this field but also describes the advances made in research on this topic and the advantages of performing socioeconomic evaluations with increasingly sophisticated tools. We also discuss the need to quantify indirect and intangible costs to translate them into quality of life and subsequently into economic cost, expressed in euros in the case of Spain. The available data indicate that the enormous cost of the disease (1200 million euros per year) is due more to disability-related expenditure than to treatment, which-although expensive-does not represent more than 16-18% of the total expenditure (approximately 200 million euros per year). The increase represented by the cost of MS is not based on higher treatment expenditure but on an increase in the incidence and-especially-the prevalence of the disease. Above all, in the last few years, there has been a considerable rise in the percentage of patients with an indication for treatment. Reflection is therefore needed on the use of drug therapy in MS, since a saving in the most effective products seems to increase the overall cost of MS, while expenditure on these drugs represents a saving in the long-term. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  11. The effects of multiple anaesthetic episodes on equine recovery quality.

    Science.gov (United States)

    Platt, J P; Simon, B T; Coleman, M; Martinez, E A; Lepiz, M A; Watts, A E

    2018-01-01

    Although rare, 70% of equine fatalities during recovery from general anaesthesia (GA) are due to catastrophic fractures from poor recovery quality. To determine the effect of repeated GA recovery on GA recovery quality. Experimental blinded trial. Eight adult horses underwent six GA events on sevoflurane for distal limb MRI examination over a 14-week period. Prior to GA recovery, xylazine was administered. Randomly ordered video-recorded GA recoveries were scored by three blinded board certified veterinary anaesthesiologists, unaware of patient identity or GA event number, for nine parameters using a 100 mm visual analogue scale (VAS) where 0 = worst and 100 = best. The number of attempts to stand, duration of lateral and sternal recumbency, total recovery duration and physiologic parameters during each GA event were recorded. Repeated measures ANOVA were used to detect differences. Agreement between observer VAS scores was determined via inter-rater reliability using an intraclass correlation. With GA recovery experience, VAS scores for balance and coordination, knuckling, and overall quality of recovery were improved and the duration of lateral recumbency was increased. There were no differences in total recovery duration, number of attempts to stand, physiologic parameters other than heart rate during GA, or VAS scores for activity in lateral recumbency, move to sternal, move to stand, or strength. Each GA event was relatively short and there was no surgical stimulation. The same results may not occur if there was surgical stimulation and pain during each GA event. Recovery from GA improves with multiple anaesthetic episodes in horses. Clinicians can advise clients that horses are likely to have better GA recovery on repeated GA recovery due to improved balance and coordination and reduced knuckling. Additionally, there is no change in anaesthetic morbidity with six repeated GA events over a 14-week period. © 2017 EVJ Ltd.

  12. Ionization, evaporation and fragmentation of C{sub 60} in collisions with highly charged C, O and F ions-effect of projectile charge state

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, A H; Misra, D; Tribedi, L C [Tata Institute of Fundamental Research, Colaba, Mumbai -5 (India)

    2007-09-15

    We study the various inelastic processes such ionization, fragmentation and evaporation of C{sub 60} molecule in collisions with fast heavy ions. We have used 2.33 MeV/u C, O and F projectile ion beams. Various ionization and fragmentation products were detected using time-of-flight mass spectrometer. The multiply charged C{sub 60}{sup r+} ions were detected for maximum r = 4. The projectile charge state (q{sub p}) dependence of the single and double ionization cross sections is well reproduced by a model based on the giant dipole plasmon resonance (GDPR). The q{sub p}-dependence of the fragmentation yields, was found to be linear. Variation of relative yields of the evaporation products of C{sub 60}{sup 2+} (i.e. C{sub 58}{sup 2+}, C{sub 56}{sup 2+} etc) and C{sub 60}{sup 3+} (i.e. C{sub 58}{sup 3+}, C{sub 56}{sup 3+} etc) with q{sub p} has also been investigated for various projectiles.

  13. Effect of Annealing Temperature on CuInSe2/ZnS Thin-Film Solar Cells Fabricated by Using Electron Beam Evaporation

    Directory of Open Access Journals (Sweden)

    H. Abdullah

    2013-01-01

    Full Text Available CuInSe2 (CIS thin films are successfully prepared by electron beam evaporation. Pure Cu, In, and Se powders were mixed and ground in a grinder and made into a pellet. The pallets were deposited via electron beam evaporation on FTO substrates and were varied by varying the annealing temperatures, at room temperature, 250°C, 300°C, and 350°C. Samples were analysed by X-ray diffractometry (XRD for crystallinity and field-emission scanning electron microscopy (FESEM for grain size and thickness. I-V measurements were used to measure the efficiency of the CuInSe2/ZnS solar cells. XRD results show that the crystallinity of the films improved as the temperature was increased. The temperature dependence of crystallinity indicates polycrystalline behaviour in the CuInSe2 films with (1 1 1, (2 2 0/(2 0 4, and (3 1 2/(1 1 6 planes at 27°, 45°, and 53°, respectively. FESEM images show the homogeneity of the CuInSe2 formed. I-V measurements indicated that higher annealing temperatures increase the efficiency of CuInSe2 solar cells from approximately 0.99% for the as-deposited films to 1.12% for the annealed films. Hence, we can conclude that the overall cell performance is strongly dependent on the annealing temperature.

  14. Effects of Music during Multiple Cesarean Section Delivery.

    Science.gov (United States)

    Handan, Eren; Sahiner, Nejla Canbulat; Bal, Meltem Demirgoz; Dissiz, Melike

    2018-03-01

    This experimental study was conducted to determine the level of anxiety in women undergoing multiple cesarean section. Sixty multiple cesarean section referrals were randomly assigned to either the experimental or control groups. Data was collected at the Karaman Public Health Hospital in Turkey, from June 2015 to June 2016. Songs chosen earlier by the patients were played during the cesarean section procedure for the experimental group. The control group was studied without music. Data was collected using a questionnaire form, and Visual Analogue Scale (VAS) was used to determine the anxiety levels. The t-test and chi-square test were used to analyse statistically significant differences between the groups. The VAS scores before and during the procedure showed significantly lower scores for the experimental group, compared to the control group (p<0.05). Music therapy reduces the physiological and cognitive responses of anxiety in patients undergoing multiple cesarean section, and can be used in the clinical practice.

  15. Evaporation of Nanosuspensions on Substrates with Different Hydrophobicity.

    Science.gov (United States)

    Perrin, Lionel; Pajor-Swierzy, Anna; Magdassi, Shlomo; Kamyshny, Alexander; Ortega, Francisco; Rubio, Ramón G

    2018-01-24

    evaporation was studied by scanning electronic microscopy, and the effects of the substrate, the particle nature, and their concentrations on these patterns are discussed.

  16. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  17. Fundamentals of evaporation and condensation phenomena

    International Nuclear Information System (INIS)

    Munir, Z.A.

    1979-01-01

    Fundamental relationships governing evaporation and condensation processes are reviewed. The terrace-ledge-kink (TLK) model is discussed in terms of atomic steps comprising growth and evaporation of crystals. Recent results in the field are described

  18. Using mini-games for learning multiplication and division: A longitudinal effect study

    NARCIS (Netherlands)

    Bakker, M.

    2014-01-01

    This thesis reports the findings of a three-year longitudinal research project set up to investigate the effectiveness of employing online mini-games for the learning of multiplication and division, including multiplicative fact knowledge (declarative knowledge), multiplicative operation skills

  19. Effects of Mathematics Computer Games on Special Education Students' Multiplicative Reasoning Ability

    Science.gov (United States)

    Bakker, Marjoke; van den Heuvel-Panhuizen, Marja; Robitzsch, Alexander

    2016-01-01

    This study examined the effects of a teacher-delivered intervention with online mathematics mini-games on special education students' multiplicative reasoning ability (multiplication and division). The games involved declarative, procedural, as well as conceptual knowledge of multiplicative relations, and were accompanied with teacher-led lessons…

  20. Effects of mathematics computer games on special education students’ multiplicative reasoning ability

    NARCIS (Netherlands)

    Bakker, M.|info:eu-repo/dai/nl/355337770; Van den Heuvel-Panhuizen, M.|info:eu-repo/dai/nl/069266255; Robitzsch, Alexander

    2016-01-01

    This study examined the effects of a teacher-delivered intervention with online math-ematics mini-games on special education students’ multiplicative reasoning ability(multiplication and division). The games involved declarative, procedural, as well asconceptual knowledge of multiplicative

  1. Suppressive effect of glucocorticoids on TNF-alpha production is associated with their clinical effect in multiple sclerosis

    NARCIS (Netherlands)

    van Winsen, L.M.L.; Polman, C.H.; Dijkstra, C.D.; Tilders, F.J.H.; Uitdehaag, B.M.J.

    2010-01-01

    A reduced sensitivity to glucocorticoids can affect the clinical effect of treatment with high-dose intravenous methylprednisolone in multiple sclerosis. We prospectively studied 27 multiple sclerosis patients who were treated with intravenous methylprednisolone. Before and after treatment in vitro

  2. Evaporation heat transfer of hot water from horizontal free service

    International Nuclear Information System (INIS)

    Koizumi, Y.; Ebihara, Y.; Hirota, T.; Murase, M.

    2011-01-01

    Evaporation heat transfer from the hot water flow to the cold air flow in a horizontal duct was examined. Hot water was in the range of 35 o C ~ 65 o C. Cold air was approximately 25 o C. The air velocity was varied from 0.0656 m/s ~ 1.41 m/s. The heat transfer rate from the water flow to the air flow became large with an increase in the air velocity. The higher the water temperature was, the larger the heat transfer rate was. When the total heat flux from water to the air flow is divided into two terms; the evaporation term and the forced flow convection term, the evaporation term dominate main part and that is about 90 ~ 80 % of the total heat flux. The measured values of the evaporation term and the forced flow convection term were larger than the predicted because of the effect of the diffusion of evaporated vapor. The correlation to predict the heat transfer from the hot water flow to the cold air flow with the evaporation was developed by modifying the laminar flow mass transfer correlation and the laminar forced convection heat transfer correlation. Good results were obtained. (author)

  3. Urban evaporation rates for water-permeable pavements.

    Science.gov (United States)

    Starke, P; Göbel, P; Coldewey, W G

    2010-01-01

    In urban areas the natural water balance is disturbed. Infiltration and evaporation are reduced, resulting in a high surface runoff and a typical city climate, which can lead to floods and damages. Water-permeable pavements have a high infiltration rate that reduces surface runoff by increasing the groundwater recharge. The high water retention capacity of the street body of up to 51 l/m(2) and its connection via pores to the surface lead to higher evaporation rates than impermeable surfaces. A comparison of these two kinds of pavements shows a 16% increase in evaporation levels of water-permeable pavements. Furthermore, the evaporation from impermeable pavements is linked directly to rain events due to fast-drying surfaces. Water-permeable pavements show a more evenly distributed evaporation after a rain event. Cooling effects by evaporative heat loss can improve the city climate even several days after rain events. On a large scale use, uncomfortable weather like sultriness or dry heat can be prevented and the urban water balance can be attenuated towards the natural.

  4. Performance Improvement of a Radioactive Forced Circulation Evaporator System

    International Nuclear Information System (INIS)

    Zaki, A.A.; Hala, A.A.; Othman, E.A.

    2016-01-01

    Evaporation is a proven method for treatment of liquid radioactive wastes providing both good decontamination and high concentration. In a radioactive waste treatment plant a forced circulation evaporator is used to reduce the volume of radioactive liquid wastes arising from different applications of nuclear industries. The safe operation, limiting the composition of the liquid radioactive waste at a prescribed value, with high performance efficiency, requires good control for the evaporator operating pressure and the level of liquid waste inside the separator part of the evaporator. The aim of this work was to improve the safety and performance of a forced-circulation evaporator used in a liquid radioactive wastes treatment plant. In this respect, a level controller system for this type of evaporator was designed, where proportional (P), proportional Integral (PI) and deadbeat response controllers for the separator level system were suggested. More over, an ideal 2×2(2 inputs and 2 outputs )de coupler controller for controlling the operating pressure and the product composition was developed. Computer results demonstrated that the deadbeat response has been success fully obtained from the developed separator control system. The maximum over shoot in the unit-step response curve was reduce d to 25 % and the settling time also was reduced to more than the half; about 26 minutes using Ziegler-Nichols tuning technique.The designed de coupling controller has been found effective in achieving a good trade-off between stability and performance

  5. Evaporation heat transfer of hot water from horizontal free service

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, Y.; Ebihara, Y.; Hirota, T. [Shinshu Univ., Ueda, Nagano (Japan); Murase, M. [INSS, Mihama-cho, Fukui (Japan)

    2011-07-01

    Evaporation heat transfer from the hot water flow to the cold air flow in a horizontal duct was examined. Hot water was in the range of 35{sup o}C ~ 65{sup o}C. Cold air was approximately 25{sup o}C. The air velocity was varied from 0.0656 m/s ~ 1.41 m/s. The heat transfer rate from the water flow to the air flow became large with an increase in the air velocity. The higher the water temperature was, the larger the heat transfer rate was. When the total heat flux from water to the air flow is divided into two terms; the evaporation term and the forced flow convection term, the evaporation term dominate main part and that is about 90 ~ 80 % of the total heat flux. The measured values of the evaporation term and the forced flow convection term were larger than the predicted because of the effect of the diffusion of evaporated vapor. The correlation to predict the heat transfer from the hot water flow to the cold air flow with the evaporation was developed by modifying the laminar flow mass transfer correlation and the laminar forced convection heat transfer correlation. Good results were obtained. (author)

  6. Evaporative lithographic patterning of binary colloidal films.

    Science.gov (United States)

    Harris, Daniel J; Conrad, Jacinta C; Lewis, Jennifer A

    2009-12-28

    Evaporative lithography offers a promising new route for patterning a broad array of soft materials. In this approach, a mask is placed above a drying film to create regions of free and hindered evaporation, which drive fluid convection and entrained particles to regions of highest evaporative flux. We show that binary colloidal films exhibit remarkable pattern formation when subjected to a periodic evaporative landscape during drying.

  7. Evaporative cooling in polymer electrolyte fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Shimotori, S; Sonai, A [Toshiba Corp. Tokyo (Japan)

    1996-06-05

    The concept of the evaporative cooling for the internally humidified PEFC was confirmed by the experiment. The evaporative cooling rates at the anode and the cathode were mastered under the various temperatures and air utilizations. At a high temperature the proportion of the evaporative cooling rate to the heat generation rate got higher, the possibility of the evaporative cooling was demonstrated. 2 refs., 7 figs., 1 tab.

  8. Evaporation of Lennard-Jones clusters

    International Nuclear Information System (INIS)

    Roman, C.E.; Garzon, I.L.

    1991-01-01

    Extensive molecular dynamics simulations have been done to study the evaporation of a 13-atom Lennard-Jones cluster. The survival probability and the evaporative lifetime are calculated as a function of the cluster total energy from a classical trajectory analysis. The results are interpreted in terms of the RRK theory of unimolecular dissociation. The calculation of the binding energy of the evaporated species from the evaporation rate and the average kinetic energy release is discussed. (orig.)

  9. Stick-Jump (SJ) Evaporation of Strongly Pinned Nanoliter Volume Sessile Water Droplets on Quick Drying, Micropatterned Surfaces.

    Science.gov (United States)

    Debuisson, Damien; Merlen, Alain; Senez, Vincent; Arscott, Steve

    2016-03-22

    We present an experimental study of stick-jump (SJ) evaporation of strongly pinned nanoliter volume sessile water droplets drying on micropatterned surfaces. The evaporation is studied on surfaces composed of photolithographically micropatterned negative photoresist (SU-8). The micropatterning of the SU-8 enables circular, smooth, trough-like features to be formed which causes a very strong pinning of the three phase (liquid-vapor-solid) contact line of an evaporating droplet. This is ideal for studying SJ evaporation as it contains sequential constant contact radius (CCR) evaporation phases during droplet evaporation. The evaporation was studied in nonconfined conditions, and forced convection was not used. Micropatterned concentric circles were defined having an initial radius of 1000 μm decreasing by a spacing ranging from 500 to 50 μm. The droplet evaporates, successively pinning and depinning from circle to circle. For each pinning radius, the droplet contact angle and volume are observed to decrease quasi-linearly with time. The experimental average evaporation rates were found to decrease with decreasing pining radii. In contrast, the experimental average evaporation flux is found to increase with decreasing droplet radii. The data also demonstrate the influence of the initial contact angle on evaporation rate and flux. The data indicate that the total evaporation time of a droplet depends on the specific micropattern spacing and that the total evaporation time on micropatterned surfaces is always less than on flat, homogeneous surfaces. Although the surface patterning is observed to have little effect on the average droplet flux-indicating that the underlying evaporation physics is not significantly changed by the patterning-the total evaporation time is considerably modified by patterning, up to a factor or almost 2 compared to evaporation on a flat, homogeneous surface. The closely spaced concentric circle pinning maintains a large droplet radius and

  10. An evaporation driven pump for microfluidics applications

    NARCIS (Netherlands)

    Nie, C.; Mandamparambil, R.; Frijns, A.J.H.; den Toonder, J.M.J.; Tadrist, L.; Graur, I.

    2014-01-01

    We present an evaporation driven micro-pump for micro fluidic applications on a foil. In such a device, the evaporation rate is controlled by the geometry of the channel outlet and its temperature. The evaporation is also influenced by environmental parameters such as air humidity and temperature.

  11. Evaporative water loss, relative water economy and evaporative partitioning of a heterothermic marsupial, the monito del monte (Dromiciops gliroides).

    Science.gov (United States)

    Withers, Philip C; Cooper, Christine E; Nespolo, Roberto F

    2012-08-15

    We examine here evaporative water loss, economy and partitioning at ambient temperatures from 14 to 33°C for the monito del monte (Dromiciops gliroides), a microbiotheriid marsupial found only in temperate rainforests of Chile. The monito's standard evaporative water loss (2.58 mg g(-1) h(-1) at 30°C) was typical for a marsupial of its body mass and phylogenetic position. Evaporative water loss was independent of air temperature below thermoneutrality, but enhanced evaporative water loss and hyperthermia were the primary thermal responses above the thermoneutral zone. Non-invasive partitioning of total evaporative water loss indicated that respiratory loss accounted for 59-77% of the total, with no change in respiratory loss with ambient temperature, but a small change in cutaneous loss below thermoneutrality and an increase in cutaneous loss in and above thermoneutrality. Relative water economy (metabolic water production/evaporative water loss) increased at low ambient temperatures, with a point of relative water economy of 15.4°C. Thermolability had little effect on relative water economy, but conferred substantial energy savings at low ambient temperatures. Torpor reduced total evaporative water loss to as little as 21% of normothermic values, but relative water economy during torpor was poor even at low ambient temperatures because of the relatively greater reduction in metabolic water production than in evaporative water loss. The poor water economy of the monito during torpor suggests that negative water balance may explain why hibernators periodically arouse to normothermia, to obtain water by drinking or via an improved water economy.

  12. Effect of gamma irradiation, evaporation retardants and transpiration suppressants on grain yield, nutrient uptake and moisture-use efficiency on bread wheat (Triticum aestivum)

    International Nuclear Information System (INIS)

    Dash, D.K.; Sen, Avijit; Misra, N.M.

    1988-01-01

    A field trial was conducted on 'Malaviya 37' bread wheat (Triticum aestivum Linn. emend. Fiori and Paol.) in 1982-83 and 1983-84. It included 4 dos es of gamma irradiation of seeds (0, 2.5, 4.5 and 6.5 kR) and 5 treatments of evaporation retardants and transpiration suppressants, viz. control, rice (Oryza sativa Linn.) straw, wheat straw, rice straw + phenyl mercuric acetate (150 ppm) and wheat straw + kaolin (6 per cent). Seed irradiation with gamma-rays at 6.5 kR and wheat straw + kaolin gave 11.76 and 61.37 per cent higher yield than the control respectively. For moisture-use efficiency and NPK uptake these treatments also showed the same trend. (author). 12 refs

  13. Water Evaporation in Swimming Baths

    DEFF Research Database (Denmark)

    Hyldgård, Carl-Erik

    This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which are repres......This paper is publishing measuring results from models and full-scale baths of the evaporation in swimming baths, both public baths and retraining baths. Moreover, the heat balance of the basin water is measured. In addition the full-scale measurements have given many experiences which...... are represented in instructions for carrying out and running swimming baths. If you follow the instructions you can achieve less investments, less heat consumption and a better comfort to the bathers....

  14. Experimental results on evaporation waves

    Science.gov (United States)

    Grana Otero, Jose; Parra Fabian, Ignacio

    2010-11-01

    A liquid contained in a vertical glass tube is suddenly depressurized from a high initial pressure down to one for which the stable state is vapour, so vaporization sets off at the free surface. For large enough evaporation rates, the planar vapour-liquid interface is Darrieus-Landau unstable [1], leading to the interface surface rippling close to the instability threshold. Further increasing the initial to final pressure ratio brings about evaporation waves [2,3], in which a highly corrugated front propagates downwards into the liquid. A new experimental method is presented as well as some experimental results obtained by tracking the evolution of the front with a high speed camera. In addition, a number of new phenomena related to the dynamics of bubbles growth at the walls has been uncovered. In particular, a new mode of propagation of the evaporation front is found. In this mode the front originates from below the interface, so the propagation is upwards against gravity with a curved but smooth front.[4pt] [1] F. J. Higuera, Phys. Fluids, V. 30, 679 (1987).[0pt] [2] J.E.Shepherd and B.Sturtevant, J.Fluid Mech., V.121,379 (1982).[0pt] [3] P.Reinke and G.Yadigaroglu, Int.J.Multiph. Flow, V.27,1487 (2001).

  15. Cooling clothing utilizing water evaporation

    DEFF Research Database (Denmark)

    Sakoi, Tomonori; Tominaga, Naoto; Melikov, Arsen Krikor

    2014-01-01

    . To prevent wet discomfort, the T-shirt was made of a polyester material having a water-repellent silicon coating on the inner surface. The chest, front upper arms, and nape of the neck were adopted as the cooling areas of the human body. We conducted human subject experiments in an office with air......We developed cooling clothing that utilizes water evaporation to cool the human body and has a mechanism to control the cooling intensity. Clean water was supplied to the outer surface of the T-shirt of the cooling clothing, and a small fan was used to enhance evaporation on this outer surface...... temperature ranging from 27.4 to 30.7 °C to establish a suitable water supply control method. A water supply control method that prevents water accumulation in the T-shirt and water dribbling was validated; this method is established based on the concept of the water evaporation capacity under the applied...

  16. Effect of multiple subcultures on Musa shoots derived from cassava ...

    African Journals Online (AJOL)

    Shoot tip explants excised from in vitro plantlets of two Musa genotypes (TM3X 15108-6 and TMBX 612-74) were seeded singly into test tubes containing twenty milliliters each of Musa multiplication medium gelled differently in 60 and 70 gL-l cassava starch as well as 5 gL-l agar and placed on shelves under 14 h photo ...

  17. Fundamental principles of nanostructures and multiple exciton generation effect in quantum dots

    International Nuclear Information System (INIS)

    Turaeva, N.; Oksengendler, B.; Rashidova, S.

    2011-01-01

    In this work the theoretical aspects of the effect of multiple exciton generation in QDs has been studied. The statistic theory of multiple exciton generation in quantum dots is presented based on the Fermi approach to the problem of multiple generation of elementary particles at nucleon-nucleon collisions. Our calculations show that the quantum efficiencies of multiple exciton generation in various quantum dots at absorption of single photon are in a good agreement with the experimental data. The microscopic mechanism of this effect is based on the theory of electronic 'shaking'. In the work the deviation of averaged multiplicity of MEG effect from the Poisson law of fluctuations has been investigated. Besides, the role of interface electronic states of quantum dot and ligand has been considered by means of quantum mechanics. The size optimization of quantum dot has been arranged to receive the maximum multiplicity of MEG effect. (authors)

  18. Heat and mass transfer analogies for evaporation models at high evaporation rate

    OpenAIRE

    Trontin , P.; Villedieu , P.

    2014-01-01

    International audience; In the framework of anti and deicing applications, heated liquid films can appear above the ice thickness, or directly above the wall. Then, evaporation plays a major role in the Messinger balance and evaporated mass has to be predicted accurately. Unfortunately, it appears that existing models under-estimate evaporation at high temperature. In this study, different evaporation models at high evaporation rates are studied. The different hypothesis on which these models...

  19. Experimental study of falling film evaporation in large scale rectangular channel

    International Nuclear Information System (INIS)

    Huang, X.G.; Yang, Y.H.; Hu, P.

    2015-01-01

    Highlights: • This paper studies the falling film evaporation in large scale rectangular channel experimentally. • The effects of air flow rate, film temperature and film flow rate on falling film evaporation are analyzed. • Increasing the air flow rate is considered as an efficient method to enhance the evaporation rate. • A correlation including the wave effect for falling film evaporation is derived based on heat and mass transfer analogy. - Abstract: The falling film evaporation in a large scale rectangular channel is experimentally studied in this paper for the design and improvement of passive containment cooling system. The evaporation mass transfer coefficient h D is obtained by the evaporation rate and vapor partial pressure difference of film surface and air bulk. The experimental results indicate that increasing of air flow rate appears to enhance h D , while the film temperature and film flow rate have little effect on h D . Since the wave effect on evaporation is noticed in experiment, the evaporation mass transfer correlation including the wave effect is developed on the basis of heat and mass transfer analogy and experimental data

  20. Variability of Evaporation and Precipitation over the Ocean from Satellite Data

    Science.gov (United States)

    Malinin, V. N.; Gordeeva, S. M.

    2017-12-01

    HOAPS-3 and PMWC satellite archives for 1988-2008 are used to estimate moisture-exchange components between the ocean and atmosphere (evaporation, precipitation, and the difference between them or effective evaporation). Moisture-exchange components for the entire World Ocean and for the North Atlantic Ocean within 30°-60° N are calculated. A strong overestimation of the global values of effective evaporation by HOAPS data (mainly caused by a decrease in precipitation) is shown. In the interannual variability of effective evaporation, there is clearly an overestimated positive trend, which contradicts the real increase in the Global Sea Level. Large systematic errors in moisture-exchange components are revealed for the North Atlantic water area. According to HOAPS data, there is a significant underestimation of evaporation and effective evaporation. According to PMWC data, the amount of precipitation is significantly overestimated and evaporation is underestimated. As a consequence, effective evaporation becomes negative, which is impossible. Low accuracy in the estimation of moisture-exchange components and the need to improve old estimates and develop new evaporation and precipitation databases based on satellite data are noted.

  1. Influence of electron evaporative cooling on ultracold plasma expansion

    International Nuclear Information System (INIS)

    Wilson, Truman; Chen, Wei-Ting; Roberts, Jacob

    2013-01-01

    The expansion of ultracold neutral plasmas (UCP) is driven primarily by the thermal pressure of the electron component and is therefore sensitive to the electron temperature. For typical UCP spatial extents, evaporative cooling has a significant influence on the UCP expansion rate at lower densities (less than 10 8 /cm 3 ). We studied the effect of electron evaporation in this density range. Owing to the low density, the effects of three-body recombination were negligible. We modeled the expansion by taking into account the change in electron temperature owing to evaporation as well as adiabatic expansion and found good agreement with our data. We also developed a simple model for initial evaporation over a range of ultracold plasma densities, sizes, and electron temperatures to determine over what parameter range electron evaporation is expected to have a significant effect. We also report on a signal calibration technique, which relates the signal at our detector to the total number of ions and electrons in the ultracold plasma

  2. Effect of failures and repairs on multiple cell production lines

    Energy Technology Data Exchange (ETDEWEB)

    Legato, P.; Bobbio, A.; Roberti, L.

    1989-01-01

    This paper examines a production line composed of multiple stages, or cells, which are passed in sequential order to arrive to the final product. Two possible coordination disciplines are considered, namely: the classical tandem arrangement of sequential working centers with input buffer and the kanban scheme, considered the Japanese shop floor realization of the Just-In-Time (JIT) manifacturing approach. The production line is modelled and analysed by means of Stochastic Petri Nets (SPN). Finally an analysis is made of the possibility that the working cells can incur failure/repair cycles perturbing the production flow of the line and thus reduce performance indices.

  3. Effect of multiplicative noise on stationary stochastic process

    Science.gov (United States)

    Kargovsky, A. V.; Chikishev, A. Yu.; Chichigina, O. A.

    2018-03-01

    An open system that can be analyzed using the Langevin equation with multiplicative noise is considered. The stationary state of the system results from a balance of deterministic damping and random pumping simulated as noise with controlled periodicity. The dependence of statistical moments of the variable that characterizes the system on parameters of the problem is studied. A nontrivial decrease in the mean value of the main variable with an increase in noise stochasticity is revealed. Applications of the results in several physical, chemical, biological, and technical problems of natural and humanitarian sciences are discussed.

  4. Multiple-phase behavior and memory effect of polymer gel

    CERN Document Server

    Annaka, M; Nakahira, T; Sugiyama, M; Hara, K; Matsuura, T

    2002-01-01

    A poly(4-acrylamidosalicylic acid) gel (PASA gel) exhibits multiple phases as characterized by distinct degrees of swelling; the gel can take one of four different swelling values, but none of the intermediate values. The gel has remarkable memory: the phase behavior of the gel depends on whether the gel has experienced the most swollen phase or the most collapsed phase in the immediate past. The information is stored and reversibly erased in the form of a macroscopic phase transition behavior. The structure factors corresponding to these four phases were obtained by SANS, which indicated the presence of characteristic structures depending on pH and temperature, particularly in the shrunken state. (orig.)

  5. Effect of reheating on predictions following multiple-field inflation

    Science.gov (United States)

    Hotinli, Selim C.; Frazer, Jonathan; Jaffe, Andrew H.; Meyers, Joel; Price, Layne C.; Tarrant, Ewan R. M.

    2018-01-01

    We study the sensitivity of cosmological observables to the reheating phase following inflation driven by many scalar fields. We describe a method which allows semianalytic treatment of the impact of perturbative reheating on cosmological perturbations using the sudden decay approximation. Focusing on N -quadratic inflation, we show how the scalar spectral index and tensor-to-scalar ratio are affected by the rates at which the scalar fields decay into radiation. We find that for certain choices of decay rates, reheating following multiple-field inflation can have a significant impact on the prediction of cosmological observables.

  6. Thermal analysis of a direct evaporative cooling system enhancement with desiccant dehumidification for vehicular air conditioning

    International Nuclear Information System (INIS)

    Alahmer, Ali

    2016-01-01

    Highlights: • Thermal analysis was conducted to design a desiccant evaporative cooling system for vehicular air conditioning. • EC is more efficient than the conventional air conditioning when the gasoline price is more than 0.34 $/liter. • Drawbacks of evaporative cooler of increased weight and reduced COP. • A rotary desiccant dehumidifier with generation was combined with evaporative cooling to be more efficient. - Abstract: This manuscript analyzes the sub-systems of evaporative cooler (EC) combined with desiccant dehumidification and regeneration for automotive air conditioning purpose. The thermodynamic and psychometric analysis was conducted to design all evaporative cooling system components in terms of desiccant selection, regeneration process, compact heat exchanger and evaporative cooler. Moreover, the effect of the desiccant, heat exchanger and evaporative performances on the mass flow rate and water sprayed required for evaporative cooling system was investigated. The results show that the theoretical evaporative cooling design will achieve two main objectives: lower fuel consumption and less environmental pollutants. However, it has the two drawbacks in terms of increased weight and reduces the coefficient of performance (COP). The main remark is that evaporating cooling system is more efficient than the conventional air conditioning when the gasoline price is more than 0.34 $/liter.

  7. Does evaporation paradox exist in China?

    Directory of Open Access Journals (Sweden)

    Z. T. Cong

    2009-03-01

    Full Text Available One expected consequence of global warming is the increase in evaporation. However, lots of observations show that the rate of evaporation from open pans of water has been steadily decreasing all over the world in the past 50 years. The contrast between expectation and observation is called "evaporation paradox". Based on data from 317 weather stations in China from 1956 to 2005, the trends of pan evaporation and air temperature were obtained and evaporation paradox was analyzed. The conclusions include: (1 From 1956 to 2005, pan evaporation paradox existed in China as a whole while pan evaporation kept decreasing and air temperature became warmer and warmer, but it does not apply to Northeast and Southeast China; (2 From 1956 to 1985, pan evaporation paradox existed narrowly as a whole with unobvious climate warming trend, but it does not apply to Northeast China; (3 From 1986 to 2005, in the past 20 years, pan evaporation paradox did not exist for the whole period while pan evaporation kept increasing, although it existed in South China. Furthermore, the trend of other weather factors including sunshine duration, windspeed, humidity and vapor pressure deficit, and their relations with pan evaporation are discussed. As a result, it can be concluded that pan evaporation decreasing is caused by the decreasing in radiation and wind speed before 1985 and pan evaporation increasing is caused by the decreasing in vapor pressure deficit due to strong warming after 1986. With the Budyko curve, it can be concluded that the actual evaporation decreased in the former 30 years and increased in the latter 20 year for the whole China.

  8. Multiple-effect diffusion solar still coupled with a vacuum-tube collector and heat pipe

    KAUST Repository

    Chong, Tze-Ling; Huang, Bin-Juine; Wu, Po-Hsien; Kao, Yeong-Chuan

    2014-01-01

    The present study develops a multiple-effect diffusion solar still (MEDS) with a bended-plate design in multiple-effect diffusion unit (MDU) to solve the peel-off problem of wick material. The MDU is coupled with a vacuum-tube solar collector

  9. Simple and effective method of determining multiplicity distribution law of neutrons emitted by fissionable material with significant self -multiplication effect

    International Nuclear Information System (INIS)

    Yanjushkin, V.A.

    1991-01-01

    At developing new methods of non-destructive determination of plutonium full mass in nuclear materials and products being involved in uranium -plutonium fuel cycle by its intrinsic neutron radiation, it may be useful to know not only separate moments but the multiplicity distribution law itself of neutron leaving this material surface using the following as parameters - firstly, unconditional multiplicity distribution laws of neutrons formed in spontaneous and induced fission acts of the given fissionable material corresponding nuclei and unconditional multiplicity distribution law of neutrons caused by (α,n) reactions at light nuclei of some elements which compose this material chemical structure; -secondly, probability of induced fission of this material nuclei by an incident neutron of any nature formed during the previous fissions or(α,n) reactions. An attempt to develop similar theory has been undertaken. Here the author proposes his approach to this problem. The main advantage of this approach, to our mind, consists in its mathematical simplicity and easy realization at the computer. In principle, the given model guarantees any good accuracy at any real value of induced fission probability without limitations dealing with physico-chemical composition of nuclear material

  10. Effect of Population III Multiplicity on Dark Star Formation

    Science.gov (United States)

    Stacy, Athena; Pawlik, Andreas H.; Bromm, Volker; Loeb, Abraham

    2012-01-01

    We numerically study the mutual interaction between dark matter (DM) and Population III (Pop III) stellar systems in order to explore the possibility of Pop III dark stars within this physical scenario. We perform a cosmological simulation, initialized at z approx. 100, which follows the evolution of gas and DM. We analyze the formation of the first mini halo at z approx. 20 and the subsequent collapse of the gas to densities of 10(exp 12)/cu cm. We then use this simulation to initialize a set of smaller-scale 'cut-out' simulations in which we further refine the DM to have spatial resolution similar to that of the gas. We test multiple DM density profiles, and we employ the sink particle method to represent the accreting star-forming region. We find that, for a range of DM configurations, the motion of the Pop III star-disk system serves to separate the positions of the protostars with respect to the DM density peak, such that there is insufficient DM to influence the formation and evolution of the protostars for more than approx. 5000 years. In addition, the star-disk system causes gravitational scattering of the central DM to lower densities, further decreasing the influence of DM over time. Any DM-powered phase of Pop III stars will thus be very short-lived for the typical multiple system, and DM will not serve to significantly prolong the life of Pop III stars.

  11. Salt evaporation behaviors of uranium deposits from an electrorefiner

    International Nuclear Information System (INIS)

    Sung Bin Park; Dong Wook Cho; Gyu Hwan Oh; Sung Chan Hwang; Young Ho Kang; Hansoo Lee; Eung Ho Kim; Seong-Won Park; Jong Hyeon Lee

    2010-01-01

    From an electrorefining process, uranium deposits were recovered at the solid cathode of an electrorefining system. The uranium deposits from the electrorefiner contained about 30-40 wt% salts. In order to recover pure uranium and transform it into metal ingots, these salts have to be removed. A salt distiller was adapted for a salt evaporation. A batch operation for the salt removal was carried out by a heating and a vacuum evaporation. The operational conditions were a 700-1,000 deg C hold temperature and less than a 1 Torr under Argon atmosphere, respectively. The behaviors of the salt evaporations were investigated by focusing on the effects of the pressure and the holding temperature for the salt distillation. The removal efficiencies of the salts were obtained with regard to the operational conditions. The experimental results of the salt evaporations were evaluated by using the Hertz-Langmuir relation. The effective evaporation coefficients of this relation were obtained with regards to the vacuum pressures and the hold temperatures. The higher the vacuum pressure and the higher the holding temperature were, the higher the removal efficiencies of the salts were. (author)

  12. Evaporation kinetics of sessile water droplets on micropillared superhydrophobic surfaces.

    Science.gov (United States)

    Xu, Wei; Leeladhar, Rajesh; Kang, Yong Tae; Choi, Chang-Hwan

    2013-05-21

    Evaporation modes and kinetics of sessile droplets of water on micropillared superhydrophobic surfaces are experimentally investigated. The results show that a constant contact radius (CCR) mode and a constant contact angle (CCA) mode are two dominating evaporation modes during droplet evaporation on the superhydrophobic surfaces. With the decrease in the solid fraction of the superhydrophobic surfaces, the duration of a CCR mode is reduced and that of a CCA mode is increased. Compared to Rowan's kinetic model, which is based on the vapor diffusion across the droplet boundary, the change in a contact angle in a CCR (pinned) mode shows a remarkable deviation, decreasing at a slower rate on the superhydrophobic surfaces with less-solid fractions. In a CCA (receding) mode, the change in a contact radius agrees well with the theoretical expectation, and the receding speed is slower on the superhydrophobic surfaces with lower solid fractions. The discrepancy between experimental results and Rowan's model is attributed to the initial large contact angle of a droplet on superhydrophobic surfaces. The droplet geometry with a large contact angle results in a narrow wedge region of air along the contact boundary, where the liquid-vapor diffusion is significantly restricted. Such an effect becomes minor as the evaporation proceeds with the decrease in a contact angle. In both the CCR and CCA modes, the evaporative mass transfer shows the linear relationship between mass(2/3) and evaporation time. However, the evaporation rate is slower on the superhydrophobic surfaces, which is more significant on the surfaces with lower solid fractions. As a result, the superhydrophobic surfaces slow down the drying process of a sessile droplet on them.

  13. Less is more : The effect of multiple implementation intentions targeting unhealthy snacking habits

    NARCIS (Netherlands)

    Verhoeven, A.A.C.; Adriaanse, M.A.; de Ridder, D.T.D.; de Vet, E.; Fennis, B.M.

    Implementation intentions have been shown to effectively change counter-intentional habits. Research has, however, almost solely been concerned with the effectiveness of a single plan. In the present research, we investigated the behavioral and cognitive implications of making multiple

  14. Less is more: The effect of multiple implementation intentions targeting unhealthy snacking habits

    NARCIS (Netherlands)

    Verhoeven, A.A.C.; Adriaanse, M.A.; Ridder, de D.T.D.; Vet, de E.W.M.L.; Fennis, B.M.

    2013-01-01

    Implementation intentions have been shown to effectively change counter-intentional habits. Research has, however, almost solely been concerned with the effectiveness of a single plan. In the present research, we investigated the behavioral and cognitive implications of making multiple

  15. Effect of a thermally evaporated bis (2-methyl-8-quninolinato)-4-phenylphenolate cathode buffer layer on the performance of polymer photovoltaic cells

    International Nuclear Information System (INIS)

    Kim, Dal-Ho; Park, Jea-Gun

    2012-01-01

    We investigated the device characteristics of polymer photovoltaic (PV) cells based on a poly(3 hexylthiophene) (P3HT) and [6,6]-phenylC61 butyric acid methyl ester (PCBM) bulk heterojunction with a cathode buffer layer of thermally evaporated bis (2-methyl-8-quninolinato)-4-phenylphenolate (BAlq). A power conversion efficiency (PCE) of 2.46% was obtained with the insertion of a 4-nm-thick BAlq, which was ∼118% increase over that for the cell without a BAlq layer, under Air Mass 1.5 Global (AM 1.5 G) illumination, 100 mW/cm 2 . Moreover, we examined the charge carrier transport property, and found that the hole mobility of the cell was enhancement due to the insertion of a BAlq layer with a thickness of less than 4 nm, which accounted for the improved in the photocurrent and fill factor (FF) due to the better balance of charge carriers. Finally, the BAlq buffer layer was also demonstrated as an optical spacer that improved the optical absorption of the P3HT:PCBM layer, which accounted for the J sc enhancement of the device.

  16. Evaporative oxidation treatability test report

    International Nuclear Information System (INIS)

    1995-04-01

    In 1992, Congress passed the Federal Facilities Compliance Act that requires the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with the Resource Conservation and Recovery Act (RCRA) land disposal restrictions (LDRs). In response to the need for mixed-waste treatment capacity where available off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed wastes with treatment options and develop a strategy for treatment of its mixed wastes. DOE-AL manages operations at nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment capacity to treat wastes at the sites where the wastes are generated. Treatment processes used for mixed waste not only must address the hazardous component (i.e., meet LDRs) but also must contain the radioactive component in a form that allows final disposal while protecting workers, the public, and the environment. On the basis of recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (GJPO) are evaporative oxidation, thermal desorption, and treated wastewater evaporation. Rust Geotech, the DOE-GJPO prime contractor, was assigned to design and fabricate mobile treatment units (MTUs) for these three technologies and to deliver the MTUs to selected DOE-AL sites. To conduct treatability tests at the GJPO, Rust leased a pilot-scale evaporative oxidation unit from the Clemson Technical Center (CTC), Anderson, South Carolina. The purpose of this report is to document the findings and results of tests performed using this equipment

  17. Coastal Zone Color Scanner atmospheric correction algorithm - Multiple scattering effects

    Science.gov (United States)

    Gordon, Howard R.; Castano, Diego J.

    1987-01-01

    Errors due to multiple scattering which are expected to be encountered in application of the current Coastal Zone Color Scanner (CZCS) atmospheric correction algorithm are analyzed. The analysis is based on radiative transfer computations in model atmospheres, in which the aerosols and molecules are distributed vertically in an exponential manner, with most of the aerosol scattering located below the molecular scattering. A unique feature of the analysis is that it is carried out in scan coordinates rather than typical earth-sun coordinates, making it possible to determine the errors along typical CZCS scan lines. Information provided by the analysis makes it possible to judge the efficacy of the current algorithm with the current sensor and to estimate the impact of the algorithm-induced errors on a variety of applications.

  18. Numerical study of a novel dew point evaporative cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Riangvilaikul, B.; Kumar, S. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120 (Thailand)

    2010-11-15

    Dew point evaporative cooling system is an alternative to vapor compression air conditioning system for sensible cooling of ventilation air. This paper presents the theoretical performance of a novel dew point evaporative cooling system operating under various inlet air conditions (covering dry, moderate and humid climate) and influence of major operating parameters (namely, velocity, system dimension and the ratio of working air to intake air). A model of the dew point evaporative cooling system has been developed to simulate the heat and mass transfer processes. The outlet air conditions and system effectiveness predicted by the model using numerical method for known inlet parameters have been validated with experimental findings and with recent literature. The model was used to optimize the system parameters and to investigate the system effectiveness operating under various inlet air conditions. (author)

  19. Evaporation From Soil Containers With Irregular Shapes

    Science.gov (United States)

    Assouline, Shmuel; Narkis, Kfir

    2017-11-01

    Evaporation from bare soils under laboratory conditions is generally studied using containers of regular shapes where the vertical edges are parallel to the flow lines in the drying domain. The main objective of this study was to investigate the impact of irregular container shapes, for which the flow lines either converge or diverge toward the surface. Evaporation from initially saturated sand and sandy loam soils packed in cones and inverted cones was compared to evaporation from corresponding cylindrical columns. The initial evaporation rate was higher in the cones, and close to potential evaporation. At the end of the experiment, the cumulative evaporation depth in the sand cone was equal to that in the column but higher than in the inverted cone, while in the sandy loam, the order was cone > column > inverted cone. By comparison to the column, stage 1 evaporation was longer in the cones, and practically similar in the inverted cones. Stage 2 evaporation rate decreased with the increase of the evaporating surface area. These results were more pronounced in the sandy loam. For the sand column, the transition between stage 1 and stage 2 evaporation occurred when the depth of the saturation front was approximately equal to the characteristic length of the soil. However, for the cone and the inverted cone, it occurred for a shallower depth of the saturation front. It seems therefore that the concept of the characteristic length derived from the soil hydraulic properties is related to drying systems of regular shapes.

  20. A theoretical study of the spheroidal droplet evaporation in forced convection

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie, E-mail: leejay1986@163.com; Zhang, Jian

    2014-11-07

    In many applications, the shape of a droplet may be assumed to be an oblate spheroid. A theoretical study is conducted on the evaporation of an oblate spheroidal droplet under forced convection conditions. Closed-form analytical expressions of the mass evaporation rate for an oblate spheroid are derived, in the regime of controlled mass-transfer and heat-transfer, respectively. The variation of droplet size during the evaporation process is presented in the regime of shrinking dynamic model. Comparing with the droplets having the same surface area, an increase in the aspect ratio enhances the mass evaporation rate and prolongs the burnout time. - Highlights: • Fully algebraic solutions for the spheroidal droplet evaporation rate is obtained. • We examine the effect of aspect ratio on the droplet evaporation. • We propose a calculation method of Nusselt number for spheroidal droplet.