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Sample records for outlet water temperature

  1. Analysis of systematic error deviation of water temperature measurement at the fuel channel outlet of the reactor Maria

    International Nuclear Information System (INIS)

    Bykowski, W.

    2000-01-01

    The reactor Maria has two primary cooling circuits; fuel channels cooling circuit and reactor pool cooling circuit. Fuel elements are placed inside the fuel channels which are parallely linked in parallel, between the collectors. In the course of reactor operation the following measurements are performed: continuous measurement of water temperature at the fuel channels inlet, continuous measurement of water temperature at the outlet of each fuel channel and continuous measurement of water flow rate through each fuel channel. Based on those thermal-hydraulic parameters the instantaneous thermal power generated in each fuel channel is determined and by use of that value the thermal balance and the degree of fuel burnup is assessed. The work contains an analysis concerning estimate of the systematic error of temperature measurement at outlet of each fuel channel and so the erroneous assessment of thermal power extracted in each fuel channel and the burnup degree for the individual fuel element. The results of measurements of separate factors of deviations for the fuel channels are enclosed. (author)

  2. Temperature measurements at the LMFBR core outlet

    International Nuclear Information System (INIS)

    Argous, J.P.; Berger, R.; Casejuane, R.; Fournier, C.; Girard, J.P.

    1980-04-01

    Over the last few years the temperature sensors used to measure the subassembly outlet temperature in French designed LMFBRs have been modified, basically in an effort to reduce the dispersion of the chromel-alumel thermocouple time constant, and to extend the frequency spectrum of the measurement signals by adding a steel electrode to from a stainless steel-sodium thermocouple. The result of this evolution is the temperature probe immersed in sodium which will be used in the SUPER PHENIX reactor. This paper describes the tests already completed or in progress on this probe. It also presents measurement data on the two basic probe parameters: the thermoelectric power of the stainless steel-sodium thermocouple and the time constant of the chromel-alumel thermocouple

  3. Influence of Fixed Temperature of Chilled Water Outlet Setting toward Performance of Chiller Absorbtion with Two Level Heating Cycle Method

    Directory of Open Access Journals (Sweden)

    I Gusti Agung Bagus Wirajati

    2012-11-01

    Full Text Available The study investigated the performance of re-heat two stage cycle. This paper presents the working principle and theexperimental results of the reheat two stage adsorption cycle. The performance of the cycle was evaluated under differentheat source temperature and mass recovery time. Coefficient of performance (COP and cooling capacity have beencalculated to analyze the influences of experimental conditions. The experimental results shown in both COP and coolingcapacity increased along with heat source temperature increased, and mass recovery time is very effective to improve theperformance without increasing heat source temperature.

  4. Computer supervision of the core outlet sodium temperatures of FBTR

    International Nuclear Information System (INIS)

    Boopathy, C.

    1976-01-01

    Safety monitoring of the fast breeder test reactor at Kalpakkam (India) is achieved by a CDPS-on-line dual computer system which is dedicated to plant supervision. The on-line subsystem scans and supervises all the 170 core thermocouple signals every second. Organisation of the reactor core instruments, supervision of mean sodium outlet temperature and mean temperature drop across the core, detection of plugging of a fuel assembly are explained. (A.K.)

  5. Consideration of hot channel factors in design for providing operating margins on coolant channel outlet temperature

    International Nuclear Information System (INIS)

    Sharma, V.K.; Surendar, C.; Bapat, C.N.

    1994-01-01

    The Indian Pressurized Heavy Water Reactors (IPHWR) are horizontal pressure tube reactors using natural uranium oxide fuel in the form of short (495 mm) clusters. The fuel clusters in the Zr-Nb pressure tubes are cooled by high pressure, high temperature and subcooled circulating heavy water. Coolant flow distribution to individual channels is designed to match the power distribution so as to obtain uniform coolant outlet temperature. However, during operation, the coolant outlet temperature in individual channels deviate from their nominal value due to: tolerances in process design; effects of grid frequency on the pump speed; deviation in channel powers from the nominal values due to on-power fuelling and movement of reactivity devices, and so on. Thus an operating margin, between the highest permissible and nominal coolant outlet temperatures, is required taking into account various hot channel factors that contribute to higher coolant outlet temperatures. The paper discusses the methodology adopted to assess various hot channel factors which would provide optimum operating margins while ensuring sub-cooling. (author)

  6. The influence of cooling water outlet of the Ringhals power plant on the coastal fish colony

    International Nuclear Information System (INIS)

    Neuman, E.

    1988-03-01

    Fish abundance has been monitored with fyke nets in 1976-1987 at the cooling-water outlet from the Ringhals nuclear power plant at the Swedish west coast and in a reference area. Judging from the dependence of the catches on temperature, Myoxocephalus scorpius, Zoarces viviparus, Gadus morhua and Platichtys flesus can be classified as cold-water species and Symphodus melops, Ctenolabrus rupestris, Carci nus maenas and Anguilla anguilla as warm-water species. As a rule the warm-water species were more and the cold-water fishes less abundant in the outlet area than in the reference area. The catch of the economically important Anguilla was about three times greater in the heated area. A lower abundance than expected of Ctenolabrus and Myoxocephalus at the outlet may be caused by a loss of eggs and larvae in the cooling-water system. (author)

  7. Simulation of water flows in multiple columns with small outlets

    International Nuclear Information System (INIS)

    Suh, Yong Kweon; Li, Zi Lu; Jeong, Jong Hyun; Lee, Jun Hee

    2006-01-01

    High-pressure die casting such as thixocasting and rheocasting is an effective process in the manufacturing automotive parts. Following the recent trend in the automotive manufacturing technologies, the product design subject to the die casting becomes more and more complex. Simultaneously the injection speed is also designed to be very high to establish a short cycle-time. Thus, the requirement of the die design becomes more demanding than ever before. In some cases the product's shape can have multiple slender manifolds. In such cases, design of the inlet and outlet parts of the die is very important in the whole manufacturing process. The main issues required for the qualified products are to attain gentle and uniform flow of the molten liquid within the passages of the die. To satisfy such issues, the inlet cylinder ('bed cylinder' in this paper) must be as large as possible and simultaneously the outlet opening at the end of each passage must be as small as possible. However these in turn obviously bring additional manufacturing costs caused by re-melting of the bed cylinder and increased power due to the small outlet-openings. The purpose of this paper is to develop effective simulation methods of calculation for fluid flows in multiple columns, which mimic the actual complex design, and to get some useful information which can give some contributions to the die-casting industry. We have used a commercial code CFX in the numerical simulation. The primary parameter involved is the size of the bed cylinder. We will show how the very small opening of the outlet can be treated with the aid of the porous model provided in the code. To check the validity of the numerical results we have also conducted a simple experiment by using water

  8. Data on microbial and physiochemical characteristics of inlet and outlet water from household water treatment devices in Rasht, Iran.

    Science.gov (United States)

    Naghipour, Dariush; Ashrafi, Seyed Davoud; Mojtahedi, Ali; Vatandoost, Masoud; Hosseinzadeh, Loghman; Roohbakhsh, Esmail

    2018-02-01

    In this research, we measured various parameters related to drinking water quality include turbidity, temperature, pH, EC, TDS, Alkalinity, fecal and total coliform, heterotrophic plate count (HPC), free chlorine, Mn, Ca, Mg, Fe, Na, Cl - , F - , HCO 3 , in the inlet and outlet of household water treatment devices according to the standard methods for the examination of water and wastewater (W.E. Federation and Association and A.P.H., 2005) [1]. Sixty four inlet and outlet water samples were taken from thirty two household water treatment devices from eight different residential blocks in Golsar town of Rasht, Iran. The data obtained from experiments were analyzed using the software Special Package for Social Sciences (SPSS 24) and MS-Excel.

  9. Pathways of warm water to the Northeast Greenland outlet glaciers

    Science.gov (United States)

    Schaffer, Janin; Timmermann, Ralph; Kanzow, Torsten; Arndt, Jan Erik; Mayer, Christoph; Schauer, Ursula

    2015-04-01

    The ocean plays an important role in modulating the mass balance of the Greenland Ice Sheet by delivering heat to the marine-terminating outlet glaciers surrounding the Greenland coast. The warming and accumulation of Atlantic Water in the subpolar North Atlantic has been suggested to be a potential driver of the glaciers' retreat over the last decades. The shelf regions thus play a critical role for the transport of Atlantic Water towards the glaciers, but also for the transfer of freshwater towards the deep ocean. A key region for the mass balance of the Greenland Ice Sheet is the Northeast Greenland Ice Stream. This large ice stream drains the second-largest basin of the Greenland Ice Sheet and feeds three outlet glaciers. The largest one is Nioghalvfjerdsfjorden (79°N-Glacier) featuring an 80 km long floating ice tongue. Both the ocean circulation on the continental shelf off Northeast Greenland and the circulation in the cavity below the ice tongue are weakly constrained so far. In order to study the relevant processes of glacier-ocean interaction we combine observations and model work. Here we focus on historic and recent hydrographic observations and on the complex bathymetry in the Northeast Greenland shelf region, which is thought to steer the flux of warm Atlantic water onto the continental shelf and into the sub-ice cavity beneath the 79°N-Glacier. We present a new global topography data set, RTopo-2, which includes the most recent surveys on the Northeast Greenland continental shelf and provides a detailed bathymetry for all around Greenland. In addition, RTopo-2 contains ice and bedrock surface topographies for Greenland and Antarctica. Based on the updated ocean bathymetry and a variety of hydrographic observations we show the water mass distribution on the continental shelf off Northeast Greenland. These maps enable us to discuss possible supply pathways of warm modified Atlantic waters on the continental shelf and thus potential ways of heat

  10. Numerical analysis of temperature fluctuation in core outlet region of China experimental fast reactor

    International Nuclear Information System (INIS)

    Zhu Huanjun; Xu Yijun

    2014-01-01

    The temperature fluctuation in core outlet region of China Experimental Fast Reactor (CEFR) was numerically simulated by the CFD software Star CCM+. With the core outlet temperatures, flows etc. under rated conditions given as boundary conditions, a 1/4 region model of the reactor core outlet region was established and calculated using LES method for this problem. The analysis results show that while CEFR operates under rated conditions, the temperature fluctuation in lower part of core outlet region is mainly concentrated in area over the edge components (steel components, control rod assembly), and one in upper part is remarkable in area above all the components. The largest fluctuation amplitude is 19 K and the remarkable frequency is below 5 Hz, and it belongs to typically low frequency fluctuation. The conclusion is useful for further experimental work. (authors)

  11. A thermal analysis computer programme package for the estimation of KANUPP coolant channel flows and outlet header temperature distribution

    International Nuclear Information System (INIS)

    Siddiqui, M.S.

    1992-06-01

    COFTAN is a computer code for actual estimation of flows and temperatures in the coolant channels of a pressure tube heavy water reactor. The code is being used for Candu type reactor with coolant flowing 208 channels. The simulation model first performs the detailed calculation of flux and power distribution based on two groups diffusion theory treatment on a three dimensional mesh and then channel powers, resulting from the summation of eleven bundle powers in each of the 208 channels, are employed to make actual estimation of coolant flows using channel powers and channel outlet temperature monitored by digital computers. The code by using the design flows in individual channels and applying a correction factor based on control room monitored flows in eight selected channels, can also provide a reserve computational tool of estimating individual channel outlet temperatures, thus providing an alternate arrangements for checking Rads performance. 42 figs. (Orig./A.B.)

  12. Method for determining the outlet temperature of fuel assemblies unsupplied with thermometer in WWER-440 reactors

    International Nuclear Information System (INIS)

    Miko, S.; Kalya, Z.; Hamvas, I.

    1987-09-01

    The paper outlines a method for the evaluation of the outlet temperatures of fuel assemblies unsupplied with thermometer in WWER-440 reactors. The process is based on interpolation of directly measured assembly temperatures. A quantitative comparison of the errors of described algorithm to those of standard plant-computer interpolation rutine is also presented. (author)

  13. Velocity profile of water vapor inside a cavity with two axial inlets and two outlets

    Science.gov (United States)

    Guadarrama-Cetina, José; Ruiz Chavarría, Gerardo

    2014-03-01

    To study the dynamics of Breath Figure phenomenon, a control of both the rate of flow and temperature of water vapor is required. The experimental setup widely used is a non hermetically closed chamber with cylindrical geometry and axial inlets and outlets. In this work we present measurements in a cylindrical chamber with diameter 10 cm and 1.5 cm height, keeping a constant temperature (10 °C). We are focused in the velocity field when a gradient of the temperatures is produced between the base plate and the vapor. With a flux of water vapor of 250 mil/min at room temperature (21 °C), the Reynolds number measured in one inlet is 755. Otherwise, the temperatures of water vapor varies from 21 to 40 °C. The velocity profile is obtained by hot wire anemometry. We identify the stagnations and the possibly instabilities regions for an empty plate and with a well defined shape obstacle as a fashion sample. Facultad de Ciencias, UNAM.

  14. The lithium-lithium hydride process for the production of hydrogen: comparison of two concepts for 950 and 1300 deg C HTR helium outlet temperature

    International Nuclear Information System (INIS)

    Oertel, M.; Weirich, W.; Kuegler, B.; Luecke, L.; Pietsch, M.; Winkelmann, U.

    1987-01-01

    The lithium-lithium hydride process serves to generate hydrogen from water efficiently, using the high temperature heat of a nuclear reactor. Thermodynamic analyses show that hydrogen can be produced with an overall thermal efficiency of 48% at conventional HTR outlet temperatures of 950 0 C. Assuming helium heat of 1300 0 C, 56% overall thermal efficiency can be achieved. (author)

  15. Water recovery and air humidification by condensing the moisture in the outlet gas of a proton exchange membrane fuel cell stack

    International Nuclear Information System (INIS)

    Wan, Z.M.; Wan, J.H.; Liu, J.; Tu, Z.K.; Pan, M.; Liu, Z.C.; Liu, W.

    2012-01-01

    Humidification is one of the most important factors for the operation of proton exchange membrane fuel cell (PEMFC). To maintain the membrane at hydrated state, plenty of water is needed for the state-of-the-art of PEMFC technology, especially in large power applications or long time operation. A condenser is introduced to separate liquid water from the air outlet for air self-sufficient in water of the stack in this study. The condensed temperature at the outlet of the condenser and water recovered amount for air self-sufficient in water are investigated theoretically and experimentally. It is shown that the condensed temperature for air self-sufficient in water is irrelevant with the working current of the stack. When the condenser outlet temperature was above the theoretical line, recovery water was not sufficient for the air humidification. On the contrary, it is sufficient while the temperature was below the theoretical line. It is also shown that when the moisture is sufficiently cooled, large amount water can be separated from the outlet gas, and it increased almost linearly with the time. With the introduction of the condenser, the recovered amount of water can easily satisfy the air self-sufficient in water by condensing the outlet gas to a proper temperature. - Highlights: ► We introduce a condenser to separate liquid water from the air outlet in the stack. ► The mechanism of air self-sufficient in water by condensing gas is presented. ► The condensed temperature and water recovered amount are investigated. ► An experiment is present to validate simplicity and feasibility of the criterion. ► The criterion for air humidification is used for choosing the condenser.

  16. Approach to the HTGR core outlet temperature measurements in the United States

    International Nuclear Information System (INIS)

    Franklin, R.; Rodriguez, C.

    1982-06-01

    The High Temperature Gas-Cooled Reactor (HTGR) constructed at Fort St. Vrain Colorado (330 MWe) used Geminol thermocouples to measure the primary coolant temperature at the core outlet. The primary coolant (helium) is heated by the graphite core to temperatures in the range of 700 deg. to 750 deg. C. The combination of the high temperature, high flow rate and radiation at the core outlet area makes it difficult to obtain accurate temperature measurements. The Geminol thermocouples installed in the Fort St. Vrain reactor have provided accurate data for several years of power operation without any failures. The indicated temperature of the core outlet thermocouples agrees with a ''traversing'' thermocouple measurement to within +-2 deg. C. The Geminol thermocouple wire was provided by the Driver-Harris Company and is similar to the chromel versus alumel thermocouple. Geminol wire is no longer distributed and on future designs, chromel versus alumel wire will be used. The next large HTGR design, which is being performed with funding support from the United States Department of Energy, will incorporate replaceable thermocouples. The thermocouples used in the Fort St. Vrain reactor were permanently installed and large in diameter (6.35 mm) to insure good reliability. The replaceable thermocouples to be used in the next large reactor will be smaller in diameter (3.18 mm). These replaceable thermocouples will be inserted into the core outlet area through long curved guide tubes that are permanently installed. These guide tubes are as long as 18 meters and must be curved to reach the core outlet regions. Tests were conducted to prove that the thermocouples could be inserted and removed through the long curved guide tubes. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

  18. Noise and DC balanced outlet temperature signals for monitoring coolant flow in LMFBR fuel elements

    International Nuclear Information System (INIS)

    Edelmann, M.

    1977-01-01

    Local cooling disturbances in LMFBR fuel elements may have serious safety implications for the whole reactor core. They have to be detected reliably in an early stage of their formation therefore. This can be accomplished in principle by individual monitoring of the coolant flow rate or the coolant outlet temperature of the sub-assemblies with high precision. In this paper a method is proposed to increase the sensitivity of outlet temperature signals to cooling disturbances. Using balanced temperature signals provides a means for eliminating the normal variations from the original signals which limit the sensitivity and speed of response to cooling disturbances. It is shown that a balanced signal can be derived easily from the original temperature signal by subtracting an inlet temperature and a neutron detector signal with appropriate time shift. The method was tested with tape-recorded noise signals of the KNK I reactor at Karlsruhe. The experimental results confirm the theoretical predictions. A significant reduction of the uncertainty of measured outlet temperatures was achieved. This enables very sensitive and fast response monitoring of coolant flow. Furthermore, it was found that minimizing the variance of the balanced signal offers the possibility for a rough determination of the heat transfer coefficient of the fuel rods during normal reactor operation at power. (author)

  19. Interferometric investigation of turbulently fluctuating temperature in an LMFBR outlet plenum geometry

    International Nuclear Information System (INIS)

    Bennett, R.G.; Golay, M.W.

    1975-01-01

    A novel optical technique is described for the measurement of turbulently fluctuating temperature in a transparent fluid flow. The technique employs a Mach-Zehnder interferometer of extremely short field and a simple photoconductive diode detector. The system produces a nearly linear D.C. electrical analog of the turbulent temperature fluctuations in a small, 1 mm 3 volume. The frequency response extends well above 2500 Hz, and can be improved by the choice of a more sophisticated photodetector. The turbulent sodium mixing in the ANL 1 1 / 15 -scale FFTF outlet plenum is investigated with a scale model outlet mixing plenum, using flows of air. The scale design represents a cross section of the ANL outlet plenum, so that the average recirculating flow inside the test cell is two dimensional. The range of the instrument is 120 0 F above the ambient air temperature. The accuracy is generally +-5 0 F, with most of the error due to noise originating from building vibrations and room noise. The power spectral density of the fluctuating temperature has been observed experimentally at six different stations in the flow. A strong 300 Hz component is generated in the inlet region, which decays as the flow progresses along streamlines. The effect of the inlet Reynolds number and the temperature difference between the inlet flows on the power spectral density has also been investigated. Traces of the actual fluctuating temperature are included for the six stations

  20. Active water exchange and life near the grounding line of an Antarctic outlet glacier

    Science.gov (United States)

    Sugiyama, Shin; Sawagaki, Takanobu; Fukuda, Takehiro; Aoki, Shigeru

    2014-08-01

    The grounding line (GL) of the Antarctic ice sheet forms the boundary between grounded and floating ice along the coast. Near this line, warm oceanic water contacts the ice shelf, producing the ice sheet's highest basal-melt rate. Despite the importance of this region, water properties and circulations near the GL are largely unexplored because in-situ observations are difficult. Here we present direct evidence of warm ocean-water transport to the innermost part of the subshelf cavity (several hundred meters seaward from the GL) of Langhovde Glacier, an outlet glacier in East Antarctica. Our measurements come from boreholes drilled through the glacier's ∼400-m-thick grounding zone. Beneath the grounding zone, we find a 10-24-m-deep water layer of uniform temperature and salinity (-1.45 °C; 34.25 PSU), values that roughly equal those measured in the ocean in front of the glacier. Moreover, living organisms are found in the thin subglacial water layer. These findings indicate active transport of water and nutrients from the adjacent ocean, meaning that the subshelf environment interacts directly and rapidly with the ocean.

  1. Impact of remodeling and rehabilitation of irrigation outlets on water distribution of a canal in Punjab, Pakistan

    International Nuclear Information System (INIS)

    Bodla, H.; Latif, M.

    2009-01-01

    The study was undertaken to investigate water distribution along a distributary canal located in the southern part of the Punjab Province. It is a large size distributary having 353 cusecs of authorized discharge. This distributary was subjected to a series of problems including but not limited to (i) withdrawal of water by illegal means, (ii) design and construction flaws in the outlets, (iii) improper selection of the type of outlets and many others. The outlets were intentionally designed wrongly by using fictitious hydraulics data to provide undue benefits to the irrigators. During construction, setting of the outlets was also intentionally fixed at lower level than the designed. Investigations were carried out to evaluate hydraulic performance of all the outlets of the channel. Based on the observed data capacity statements of all the outlets were revised. The outlets were redesigned on the basis of actual hydraulic data of each outlet. Most of the non-modular outlets (Pipe and Scratchley) were converted to semi-modular outlets (OFRB and APM). With implementation of new and modified design of the outlets at the site, equity of water distribution has been improved. The results revealed that design of the outlets had a significant impact on equitable distribution of water along the distribution. (author)

  2. Influence of the outlet air temperature on the thermohydraulic behaviour of air coolers

    Directory of Open Access Journals (Sweden)

    Đorđević Emila M.

    2003-01-01

    Full Text Available The determination of the optimal process conditions for the operation of air coolers demands a detailed analysis of their thermohydraulic behaviour on the one hand, and the estimation of the operating costs, on the other. One of the main parameters of the thermohydraulic behaviour of this type of equipment, is the outlet air temperature. The influence of the outlet air temperature on the performance of air coolers (heat transfer coefficient overall heat transfer coefficient, required surface area for heat transfer air-side pressure drop, fan power consumption and sound pressure level was investigated in this study. All the computations, using AirCooler software [1], were applied to cooling of the process fluid and the condensation of a multicomponent vapour mixture on two industrial devices of known geometries.

  3. Outlet temperature measurement correction of Gd fuel assemblies at Dukovany NPP

    International Nuclear Information System (INIS)

    Jurickova, M.

    2008-01-01

    In year 2006 we started data processing from the Dukovany NPP operating history database that contained data from the old measurement system VK3 and the new Scorpio-VVER. The work has been done in cooperation with the reactor physicists at Dukovany NPP. Obtained data from database were compared with calculated parameters from 3D diffusion macrocode Mobydick. During the data processing it was found that the Gd fuel assemblies have different time plot of measured assembly outlet temperature compared to the non-Gd fuel assemblies. Experimental studies in RRC KI found that there is insufficient coolant mixing in the region from the fuel bundle to the fuel assembly thermocouple. Due to this fact the thermocouple measure temperature is systematically higher than real temperature. There are two methods to solve this problem. The first method analyses the flow and heat transfer in the region from the fuel bundle to the fuel assembly thermocouple - this method is developed in Skoda JS. The second method statistically studies differences between the measured and calculated temperature by the Mobydick code using the operational history database. Our study is focused on the second method. Several calculation methods for the correction of measured assembly outlet temperature were developed. All correction methods were applied to the measured temperatures from the Dukovany NPP operating history database and the methods were mutually compared. In near future it is planned to compare results of our chosen correction method with modeling method, which is developing in Skoda JS and it is planned to validate both of them. Consequently, the one of these correction methods will be implemented in the modernized Scorpio-VVER for Dukovany NPP. (author)

  4. Transient Air-Water Flow and Air Demand following an Opening Outlet Gate

    Directory of Open Access Journals (Sweden)

    James Yang

    2018-01-01

    Full Text Available In Sweden, the dam-safety guidelines call for an overhaul of many existing bottom outlets. During the opening of an outlet gate, understanding the transient air-water flow is essential for its safe operation, especially under submerged tailwater conditions. Three-dimensional CFD simulations are undertaken to examine air-water flow behaviors at both free and submerged outflows. The gate, hoisted by wire ropes and powered by AC, opens at a constant speed. A mesh is adapted to follow the gate movement. At the free outflow, the CFD simulations and model tests agree well in terms of outlet discharge capacity. Larger air vents lead to more air supply; the increment becomes, however, limited if the vent area is larger than 10 m2. At the submerged outflow, a hydraulic jump builds up in the conduit when the gate reaches approximately 45% of its full opening. The discharge is affected by the tailwater and slightly by the flow with the hydraulic jump. The flow features strong turbulent mixing of air and water, with build-up and break-up of air pockets and collisions of defragmented water bodies. The air demand rate is several times as much as required by steady-state hydraulic jump with free surface.

  5. Development of neural network driven fuzzy controller for outlet sodium temperature of DHX

    International Nuclear Information System (INIS)

    Okusa, Kyoichi; Endou, Akira; Yoshikawa, Shinji; Ozawa, Kenji

    1996-01-01

    Fuzzy controls are capable to exquisitely control non-linear dynamic systems in wide operating range, using linguistic description to define the control law. However the selection and the definition of the fuzzy rules and sets require a tedious trial and error process based on experience. As a method to overcome this limitation, a neural network driven fuzzy control (NDF), where the learning capability of the neural network (NN) is used to build the fuzzy rules and sets, is presented in this paper. In the NDF control the IF part of a fuzzy control is represented by a multilayer NN while the THEN part is represented by a series of multilayer NNs which calculate the desirable control action. In this work the usual stepwise variable reduction method, used for the selection of the input variable in the THEN part NN, is replaced with a learning algorithm with forgetting mechanism that realizes the automatic reduction of the variables and the tuning up of all the fuzzy control law i.e. the membership function. The NDF has been successfully applied to control the outlet sodium temperature of a dump heat exchanger (DHX) of a FBR plant

  6. Experimental results showing the internal three-component velocity field and outlet temperature contours for a model gas turbine combustor

    CSIR Research Space (South Africa)

    Meyers, BC

    2011-09-01

    Full Text Available by the American Institute of Aeronautics and Astronautics Inc. All rights reserved ISABE-2011-1129 EXPERIMENTAL RESULTS SHOWING THE INTERNAL THREE-COMPONENT VELOCITY FIELD AND OUTLET TEMPERATURE CONTOURS FOR A MODEL GAS TURBINE COMBUSTOR BC Meyers*, GC... identifier c Position identifier F Fuel i Index L (Combustor) Liner OP Orifice plate Introduction There are often inconsistencies when comparing experimental and Computational Fluid Dynamics (CFD) simulations for gas turbine combustors [1...

  7. Evaluating Capability of Devils Lake Emergency Outlets in Lowering Lake Water Levels While Controlling flooding Damage to Downstream

    Science.gov (United States)

    Shabani, A.; Zhang, X.

    2017-12-01

    Devils Lake is an endorheic lake locate in the Red River of the North Basin with a natural outlet at a level of 444.7 meters above the sea level flowing into the Sheyenne River. Historical accumulation of salts has dramatically increased the concentration of salts in the lake, particularly of the sulfates, that are much greater than the surrounding water bodies. Since 1993, the lake water level has risen by nearly 10 meters and caused extensive flooding in the surrounding area, and greatly increased the chance of natural spillage to the Sheyenne River. To mitigate Devils Lake flooding and to prevent its natural spillage, two outlets were constructed at the west and east sides of the lake to drain the water to the Sheyenne River in a controlled fashion. However, pumping water from Devils Lake has degraded water quality of the Sheyenne River. In an earlier study, we coupled Soil and Water Assessment Tools (SWAT) and CE-QUAL-W2 models to investigate the changes of sulfate distribution as the lake water level rises. We found that, while operating the two outlets has lowered Devils Lake water level by 0.7 meter, it has also significantly impaired the Sheyenne River water quality, increasing the Sheyenne River average sulfate concentration from 105 to 585 mg l-1 from 2012 to 2014 In this study, we investigate the impact of the outlets on the Sheyenne River floodplain by coupling SWAT and HEC-RAS model. The SWAT model performed well in simulating daily streamflow in the Sheyenne River with R2>0.56 and ENS > 0.52. The simulated water depths and floodplain by HEC-RAS model for the Sheyenne River agreed well with observations. Operating the outlets from April to October can draw down the Devil Lake water level by 0.45 m, but the drained water would almost double the extension of the Sheyenne River floodplain and elevate the sulfate concentration in the Sheyenne River above the 450 mg l-1 North Dakota sulfate concentration standard for stream class I. Operating the outlets is

  8. Impact on water quality of land uses along Thamalakane-Boteti River: An outlet of the Okavango Delta

    Science.gov (United States)

    Masamba, Wellington R. L.; Mazvimavi, Dominic

    Botswana is a semiarid country and yet has one of the world’s famous wetlands: the Okavango Delta. The Thamalakane-Boteti River is one of the Delta’s outlets. The water quality of the Thamalakane-Boteti River was determined and related to its utilisation. The major land uses along the Thamalakane River within Maun are residential areas, lodges, hotels, and grazing by cattle and donkeys. The water is used as a source of water for livestock, wildlife in a game park, horticulture and domestic applications including drinking. The river is also used for fishing. To check whether these activities negatively impact on the water quality, pH, electrical conductivity, dissolved oxygen, temperature, total dissolved nitrogen and phosphorus, Faecal coliforms and Faecal streptococci and selected metals were determined from July 2005 to January 2006. The pH was near neutral except for the southern most sampling sites where values of up to 10.3 were determined. Dissolved oxygen varied from 2 mg/l to 8 mg/l. Sodium (range 0.6-3.2 mg/l), K (0.3-3.6 mg/l), Fe (1.6-6.9 mg/l) conductivity (56-430 μS/cm) and Mg (0.2-6.7 mg/l) increased with increased distance from the Delta, whereas lead showed a slight decline. Total dissolved phosphorus was low (up to 0.02 mg/l) whereas total dissolved nitrogen was in the range 0.08-1.5 mg/l. Faecal coliform (range 0-48 CFU/100 ml) and Faecal streptococci (40-260 CFU/100 ml) were low for open waters with multiple uses. The results indicate that there is possibility of pollution with organic matter and nitrogen. It is recommended that more monitoring of water quality needs to be done and the sources of pollution identified.

  9. Study on the TOC concentration in raw water and HAAs in Tehran's water treatment plant outlet.

    Science.gov (United States)

    Ghoochani, Mahboobeh; Rastkari, Noushin; Nabizadeh Nodehi, Ramin; Mahvi, Amir Hossein; Nasseri, Simin; Nazmara, Shahrokh

    2013-11-12

    A sampling has been undertaken to investigate the variation of haloacetic acids formation and nature organic matter through 81 samples were collected from three water treatment plant and three major rivers of Tehran Iran. Changes in the total organic matter (TOC), ultraviolet absorbance (UV254), specific ultraviolet absorbance (SUVA) were measured in raw water samples. Haloacetic acids concentrations were monitored using a new static headspace GC-ECD method without a manual pre-concentration in three water treatment plants. The average concentration of TOC and HAAs in three rivers and three water treatment plants in spring, summer and fall, were 4, 2.41 and 4.03 mg/L and 48.75, 43.79 and 51.07 μg/L respectively. Seasonal variation indicated that HAAs levels were much higher in spring and fall.

  10. Automated Temperature Control with Adjusting Outlet Valve of Fuel in the Process of Cooking Palm Sugar

    Science.gov (United States)

    Aripin, H.; Hiron, Nurul; Priatna, Edvin; Busaeri, Nundang; Andang, Asep; Suhartono; Sabchevski, Svilen

    2018-04-01

    In this paper, a real-time temperature control system for coconut sugar cooking is presented. It is based on a thermocouple temperature sensor. The temperature in the closed evaporator is used as a control variable of the DC servo control system for opening and closing of a valve embedded in a gas burner. The output power level, which is necessary in order to reach the target temperature is controlled by the microcontroller ATMega328P. A circuit module for control of the valve and temperature sensors as well as software for data acquisition have been implemented. The test results show that the system properly stabilizes the temperature in the closed evaporator for coconut sugar cooking in the range from room temperature to 110°C. A set point can be reached and held with an accuracy of ±0.75°C at a temperature of 110°C for 60 minutes.

  11. Control of the outlet air temperature in an air handling unit

    DEFF Research Database (Denmark)

    Brath, P.; Rasmussen, Henrik; Hägglund, T.

    1998-01-01

    This paper discuss modeling and control of the inlet temperature in an Air Handling Unit, AHU. The model is based on step response experiments made at a full scale test plant. We use gain scheduling to lower the correlation of the air flow with the process dynamic which simplify the control task...

  12. CFD analyses of the rod bowing effect on the subchannel outlet temperature distribution

    Energy Technology Data Exchange (ETDEWEB)

    Ekstroem, Karoliina; Toppila, Timo [Fortum Power and Heat, Fortum (Finland)

    2017-09-15

    In the Loviisa 1 and 2 nuclear power plants the subcooling margin of the hottest subchannel of the fuel assembly is monitored. The temperature of the coolant in the hottest subchannel is limited to the constant saturation temperature. Bending of the fuel rods occurs during normal operation due to the differences in the heat profiles of the rods. The coolant temperature will rise more in the subchannel with smaller flow area due to the bending and this has to be taken into account in the safety margin of subchannel enthalpy rise. Computational Fluid Dynamics (CFD) simulations are used to estimate how much the estimated maximum bow of a rod affects the temperature rise of the subchannel. The quantitative uncertainty of the predicted enthalpy rise in fuel bundle subchannel is estimated based on the uncertainty of modelling of mixing between subchannels. The measured turbulence quantities from LDA measurements of cold test assembly made in 1990s in Fortum are compared with CFD results to give uncertainty estimation for turbulence, which is further used for uncertainty estimation of mixing and simulated subchannel enthalpy rise.

  13. Judgement on the data for fuel assembly outlet temperatures of WWER fuel assemblies in power reactors based on measurements with experimental fuel assemblies

    International Nuclear Information System (INIS)

    Krause, F.

    1986-01-01

    In the period from 1980 to 1985, in the Rheinsberg nuclear power plant experimental fuel assemblies were used on lattices at the periphery of the core. These particular fuel assemblies dispose of an extensive in-core instrumentation with different sensors. Besides this, they are fit out with a device to systematically thottle the coolant flow. The large power gradient present at the core position of the experimental fuel assembly causes a temperature profile along the fuel assemblies which is well provable at the measuring points of the outlet temperature. Along the direction of flow this temperature profile in the coolant degrades only slowly. This effect is to be taken into account when measuring the fuel assembly outlet temperature of WWER fuel assemblies. Besides this, the results of the measurements hinted both at a γ-heating of the temperature measuring points and at tolerances in the calculation of the micro power density distribution. (author)

  14. Contamination of hospital tap water: the survival and persistence of Pseudomonas aeruginosa on conventional and 'antimicrobial' outlet fittings.

    Science.gov (United States)

    Hutchins, C F; Moore, G; Thompson, K-A; Webb, J; Walker, J T

    2017-10-01

    Pseudomonas aeruginosa infections have been linked to contaminated hospital taps, highlighting the potential for tap outlet fittings (OF) to harbour biofilm. P. aeruginosa may be transferred to OFs via contaminated cleaning cloths. Suggested interventions include flushing regimens and alternative OF designs. To investigate the transfer of P. aeruginosa from a contaminated cleaning cloth to conventional and 'antimicrobial/antibiofilm' OFs and to determine whether this contamination persists and/or leads to contamination of tap water. Microfibre cloths contaminated with P. aeruginosa (10 8  cfu/mL) were used to wipe four different types of OF [one of conventional design (OF-A) and three marketed as 'antimicrobial' and/or 'antibiofilm' (OF- B, -C and -D)]. OFs were inserted into an experimental water distribution system for up to 24 h. Survival was assessed by culture. Single and multiple water samples were collected and cultured for P. aeruginosa. The median number of P. aeruginosa transferred from cloth to OF was 5.7 × 10 5  cfu (OF-A), 1.9 × 10 6  cfu (OF-B), 1.4 × 10 5  cfu (OF-C) and 2.9 × 10 6  cfu (OF-D). Numbers declined on all OFs during the 24 h period with log reductions ranging from 3.5 (OF-C) to 5.2 (OF-B; P > 0.05). All water samples delivered immediately after OF contamination contained P. aeruginosa at ≥10 cfu per 100 mL. Contamination of water delivered from OF-A persisted despite continued flushing. Water delivered from OF-B did not contain P. aeruginosa beyond the first flush. Contaminated cleaning cloths may transfer P. aeruginosa to OFs, leading to contamination of tap water. Although not removing the potential for contamination, 'antimicrobial/antibiofilm' OFs may prevent P. aeruginosa from continually contaminating water delivered from the outlet. Copyright © 2017 The Healthcare Infection Society. All rights reserved.

  15. High temperature water chemistry monitoring

    International Nuclear Information System (INIS)

    Aaltonen, P.

    1992-01-01

    Almost all corrosion phenomena in nuclear power plants can be prevented or at least damped by water chemistry control or by the change of water chemistry control or by the change of water chemistry. Successful water chemistry control needs regular and continuous monitoring of such water chemistry parameters like dissolved oxygen content, pH, conductivity and impurity contents. Conventionally the monitoring is carried out at low pressures and temperatures, which method, however, has some shortcomings. Recently electrodes have been developed which enables the direct monitoring at operating pressures and temperatures. (author). 2 refs, 5 figs

  16. EXERGY AND CARBON CREDITS FOR SERIES CONNECTED N PHOTOVOLTAIC THERMAL - COMPOUND PARABOLIC CONCENTRATOR (PVT-CPC) COLLECTOR: AT CONSTANT OUTLET TEMPERATURE

    OpenAIRE

    Rohit Tripathi 1,*, G. N. Tiwari 2

    2017-01-01

    In the present study, overall energy and exergy performance of partially covered N photovoltaic thermal - compound parabolic concentrators (PVT-CPC) (25% covered by glass to glass PV module) collector connected in series have been carried out at constant outlet temperature mode. Further, comparison in performance for partially covered N photovoltaic thermal - compound parabolic concentrators (PVT-CPC) [case (i)] and N compound parabolic concentrators (CPC) collector [case (ii)] connected in s...

  17. Next Generation Nuclear Plant Project Technology Development Roadmaps: The Technical Path Forward for 750–800°C Reactor Outlet Temperature

    Energy Technology Data Exchange (ETDEWEB)

    John Collins

    2009-08-01

    This document presents the NGNP Critical PASSCs and defines their technical maturation path through Technology Development Roadmaps (TDRMs) and their associated Technology Readiness Levels (TRLs). As the critical PASSCs advance through increasing levels of technical maturity, project risk is reduced and the likelihood of within-budget and on-schedule completion is enhanced. The current supplier-generated TRLs and TDRMs for a 750–800°C reactor outlet temperature (ROT) specific to each supplier are collected in Appendix A.

  18. Simulation of the effects of Devils Lake outlet alternatives on future lake levels and water quality in the Sheyenne River and Red River of the North

    Science.gov (United States)

    Vecchia, Aldo V.

    2011-01-01

    Since 1992, Devils Lake in northeastern North Dakota has risen nearly 30 feet, destroying hundreds of homes, inundating thousands of acres of productive farmland, and costing more than $1 billion for road raises, levee construction, and other flood mitigation measures. In 2011, the lake level is expected to rise at least another 2 feet above the historical record set in 2010 (1,452.0 feet above the National Geodetic Vertical Datum of 1929), cresting less than 4 feet from the lake's natural spill elevation to the Sheyenne River (1,458.0 feet). In an effort to slow the rising lake and reduce the chance of an uncontrolled spill, the State of North Dakota is considering options to expand a previously constructed outlet from the west end of Devils Lake or construct a second outlet from East Devils Lake. Future outlet discharges from Devils Lake, when combined with downstream receiving waters, need to be in compliance with applicable Clean Water Act requirements. This study was completed by the U.S. Geological Survey, in cooperation with the North Dakota Department of Health Division of Water Quality, to evaluate the various outlet alternatives with respect to their effect on downstream water quality and their ability to control future lake levels.

  19. AGU hydrology publication outlets

    Science.gov (United States)

    Freeze, R. Allan

    In recent months I have been approached on several occasions by members of the hydrology community who asked me which of the various AGU journals and publishing outlets would be most suitable for a particular paper or article that they have prepared.Water Resources Research (WRR) is the primary AGU outlet for research papers in hydrology. It is an interdisciplinary journal that integrates research in the social and natural sciences of water. The editors of WRR invite original contributions in the physical, chemical and biological sciences and also in the social and policy sciences, including economics, systems analysis, sociology, and law. The editor for the physical sciences side of the journal is Donald R. Nielson, LAWR Veihmeyer Hall, University of California Davis, Davis, CA 95616. The editor for the policy sciences side of the journal is Ronald G. Cummings, Department of Economics, University of New Mexico, Albuquerque, NM 87131

  20. Double Outlet Right Ventricle

    Science.gov (United States)

    ... Right Ventricle Menu Topics Topics FAQs Double Outlet Right Ventricle Double outlet right ventricle (DORV) is a rare form of congenital heart disease. En español Double outlet right ventricle (DORV) is a rare form of congenital ...

  1. The effect and contribution of wind generated rotation on outlet temperature and heat gain of LS-2 parabolic trough solar collector

    Directory of Open Access Journals (Sweden)

    Sadaghiyani Omid Karimi

    2013-01-01

    Full Text Available The Monte Carlo ray tracing method is applied and coupled with finite volume numerical methods to study effect of rotation on outlet temperature and heat gain of LS-2 parabolic trough concentrator (PTC. Based on effect of sunshape, curve of mirror and use of MCRT, heat flux distribution around of inner wall of evacuated tube is calculated. After calculation of heat flux, the geometry of LS-2 Luz collector is created and finite volume method is applied to simulate. The obtained results are compared with Dudley et al test results for irrotational cases to validate these numerical solving models. Consider that, for rotational models ,the solving method separately with K.S. Ball's results. In this work, according to the structure of mentioned collector, we use plug as a flow restriction. In the rotational case studies, the inner wall rotates with different angular speeds. We compare results of rotational collector with irrotational. Also for these two main states, the location of plug changed then outlet temperature and heat gain of collector are studied. The results show that rotation have positive role on heat transfer processing and the rotational plug in bottom half of tube have better effectual than upper half of tube. Also the contribution of rotation is calculated in the all of case studies. Working fluid of these study is one of the oil derivatives namely Syltherm-800. The power of wind can be used to rotate tube of collector.

  2. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

  3. Water quality, hydrology, and the effects of changes in phosphorus loading to Pike Lake, Washington County, Wisconsin, with special emphasis on inlet-to-outlet short-circuiting

    Science.gov (United States)

    Rose, William J.; Robertson, Dale M.; Mergener, Elizabeth A.

    2004-01-01

    Pike Lake is a 459-acre, mesotrophic to eutrophic dimictic lake in southeastern Wisconsin. Because of concern over degrading water quality in the lake associated with further development in its watershed, a study was conducted by the U.S. Geological Survey from 1998 to 2000 to describe the water quality and hydrology of the lake, quantify sources of phosphorus including the effects of short-circuiting of inflows, and determine how changes in phosphorus loading should affect the water quality of the lake. Measuring all significant water and phosphorus sources and estimating lesser sources was the method used to construct detailed water and phosphorus budgets. The Rubicon River, ungaged near-lake surface inflow, precipitation, and ground water provide 55, 20, 17, and 7 percent of the total inflow, respectively. Water leaves the lake through the Rubicon River outlet (87 percent) or by evaporation (13 percent). Total input of phosphorus to the lake was about 3,500 pounds in 1999 and 2,400 pounds in 2000. About 80 percent of the phosphorus was from the Rubicon River, about half of which came from the watershed and half from a waste-water treatment plant in Slinger, Wisconsin. Inlet-to-outlet short-circuiting of phosphorus is facilitated by a meandering segment of the Rubicon River channel through a marsh at the north end of the lake. It is estimated that 77 percent of phosphorus from the Rubicon River in monitoring year 1999 and 65 percent in monitoring year 2000 was short-circuited to the outlet without entering the main body of the lake.

  4. Realistic thermal transient margin analysis of 'MONJU' based on plant performance measurements. Reactor vessel outlet nozzle and evaporator feed water inlet tube sheet of the manual reactor plant trip

    International Nuclear Information System (INIS)

    Yamada, Fumiaki; Mori, Takero

    2005-01-01

    In order to develop technologies and achieve safe and stable operation of Monju' as well as realize optimized design and construction of safe and economically competitive fast breeder reactors, the authors are evaluating design approach applied to 'Monju' based on actually measured behavioral data during plant operations. This report uses actual measured characteristic data of 'Monju' during a plant trip test obtained at a commissioning stage with up to 40% power output and introduces plant thermal hydraulic behavior analysis in a representative thermal transient event, i.e. a manual plant trip. Thermal transient driven loads incurred by the reactor vessel outlet nozzle and by the evaporator feed water inlet tube sheet were further derived by structural analyses and were compared with the previously derived values in the design stage and with the limit values. Though the reactor vessel outlet nozzle was exposed to larger temperature change in the trip test than the analytical prediction, the newly calculated mechanical load was about 50% of the previous evaluation in the design stage. Also, the newly analyzed mechanical load incurred by the evaporator feed water inlet tube sheet in this event had a large margin against the limit value of cumulative damage cycle fraction, although the observed temperature disturbance in a steam blow test was wilder than the analytical prediction. Thus we concluded that the Monju' plant has an assured safety margin against thermal transient in plant trip events. (author)

  5. Development of the temperature field at the WWER-440 core outlet monitoring system and application of the data analyses methods

    International Nuclear Information System (INIS)

    Spasova, V.; Georgieva, N.; Haralampieva, Tz.

    2001-01-01

    On-line internal reactor monitoring by 216 thermal couples, located at the reactor core outlet, is carried out during power operation of WWER-440 Units 1 and 2 at Kozloduy NPP. Automatic monitoring of technology process is performed by IB-500MA, which collects and performs initial data processing (discrediting and conversion of analogue signals into digital mode). The paper also presents the results and analyses of power distribution monitoring during the past 21-th and current 22-th fuel cycle at Kozloduy NPP, Unit 1 by using archiving system capacity and related software. The possibility to perform operational assessment and analysis of power distribution in the reactor core in each point of the fuel cycle is checked by comparison of the neutron-physical calculation results with reactor coolant system parameters. Paper shows that the processing and analysis of accumulated significant amount of data in the archive files increases accuracy and reliability of power distribution monitoring in the reactor core in each moment of the fuel cycle of WWER-440 reactors at Kozloduy NPP

  6. Decreasing the exhaust outlet temperatures on a class III bus with the lowest impact on the exhaust backpressure and the fuel consumption

    Science.gov (United States)

    Aslan, E.; Ozturk, Y.; Dileroglu, S.

    2017-07-01

    The focus of this study is to determine the most appropriate exhaust tail pipe form among three different type of designs with respect to their temperature loss efficiency for a 9.5m intercity bus equipped with an Euro VI diesel engine and an automated transmission. To provide lower temperatures at the exhaust outlet, mentioned designs were submitted on to a CFD simulation using Ansys Fluent 17.1, while for manufactured products, temperature measurement tests were conducted in an environmental chamber with Omega K-type thermocouples, and Flir T420 thermal camera was used to monitor outer surface temperature distributions to make a comparison between theoretical and practical results. In order to obtain these practical results, actual tests were performed in an environmental chamber with a constant ambient temperature during the vehicle exhaust emission system regeneration process. In conclusion, an exhaust tail pipe design with a diffuser having a circular contraction and expansion forms is designated since it was the most optimized option in terms of temperature loss efficiency, inconsiderable exhaust backpressure increase and manufacturing costs.

  7. Coolant mixing in LMFBR rod bundles and outlet plenum mixing transients. Progress report, December 1, 1975--February 29, 1976

    International Nuclear Information System (INIS)

    Todreas, N.E.; Golay, M.W.

    1976-01-01

    Progress is summarized in the following task areas: assessment of available data, experimental water mixing investigations, analytic model development, and analytical and experimental investigation of velocity and temperature fields in outlet plenum flow mixing

  8. Improved Algorithms for Blending Dam Releases to Meet Downstream Water-Temperature Targets in the CE-QUAL-W2 Water-Quality Model

    Science.gov (United States)

    Rounds, S. A.; Buccola, N. L.

    2014-12-01

    The two-dimensional (longitudinal, vertical) water-quality model CE-QUAL-W2, version 3.7, was enhanced with new features to help dam operators and managers efficiently explore and optimize potential solutions for temperature management downstream of thermally stratified reservoirs. Such temperature management often is accomplished by blending releases from multiple dam outlets that access water of different temperatures at different depths in the reservoir. The original blending algorithm in this version of the model was limited to mixing releases from two outlets at a time, and few constraints could be imposed. The new enhanced blending algorithm allows the user to (1) specify a time-series of target release temperatures, (2) designate from 2 to 10 floating or fixed-elevation outlets for blending, (3) impose maximum head constraints as well as minimum and maximum flow constraints for any blended outlet, and (4) set a priority designation for each outlet that allows the model to choose which outlets to use and how to balance releases among them. The modified model was tested against a previously calibrated model of Detroit Lake on the North Santiam River in northwestern Oregon, and the results compared well. The enhanced model code is being used to evaluate operational and structural scenarios at multiple dam/reservoir systems in the Willamette River basin in Oregon, where downstream temperature management for endangered fish is a high priority for resource managers and dam operators. These updates to the CE-QUAL-W2 blending algorithm allow scenarios involving complicated dam operations and/or hypothetical outlet structures to be evaluated more efficiently with the model, with decreased need for multiple/iterative model runs or preprocessing of model inputs to fully characterize the operational constraints.

  9. Stratification in SNR-300 outlet plenum

    International Nuclear Information System (INIS)

    Reinders, R.

    1983-01-01

    In the inner outlet plenum of the SNR-300 under steady state conditions a large toroidal vortex is expected. The main flow passes through the gap between dipplate and shield vessel to the outer annular space. Only 3% of the flow pass the 24 emergency cooling holes, situated in the shield vessel. The sodium leaves the reactor tank through the 3 symmetrically arranged outlet nozzles. For a scram flow rates and temperatures are decreased simultaneously, so it is expected, that stratification occurs in the inner outlet plenum. A measure of stratification effects is the Archimedes Number Ar, which is the relation of buoyancy forces (negative) to kinetic energy. (The Archimedes Number is nearly identical with the Richardson Number). For values Ar>1 stratification can occur. Under the assumption of stratification the code TIRE was developed, which is only applicable for the period of time after some 50 sec after scram. This code serves for long term calculations. As the equations are very simple, it is a very fast code which gives the possibility to calculate transients for some hours real time. This code mainly has to take into account the pressure difference between inner plenum and outlet annulus caused by geodatic pressure. That force is in equilibrium with the pressure drop over the gap and holes in the shield vessel. For more detailed calculations of flow pattern and temperature distribution the code MIX and INKO 2T are applied. MIX was developed and validated at ANL, INKO 2T is a development of INTERATOM. INKO 2T is under validation. Mock up experiments were carried out with water to simulate the transient behavior of the SNR-300 outlet plenum. Calculations obtained by INKO 2T for steady state and the transient are shown for the flow pattern. Results of measurements also prove that stratification begins after about 30 sec. Measurements and detailed calculations show that it is admissible to use the code TIRE for the long term calculations. Calculations for a scram

  10. Micro-scale heterogeneity in water temperature | Dallas | Water SA

    African Journals Online (AJOL)

    Micro-scale heterogeneity in water temperature was examined in 6 upland sites in the Western Cape, South Africa. Hourly water temperature data converted to daily data showed that greatest differences were apparent in daily maximum temperatures between shallow- and deep-water biotopes during the warmest period of ...

  11. Fuel assembly outlet temperature profile influence on core by-pass flow and power distribution determination in WWER -440 reactors

    International Nuclear Information System (INIS)

    Petenyi, V.; Klucarova, K.; Remis, J.

    2003-01-01

    The in core instrumentation of the WWER-440 reactors consists of the thermocouple system and the system of self powered detectors (SPD). The thermocouple systems are positioned about 50 cm above the fuel bundle upper flow-mixing grid. The usual assumption is that, the coolant is well mixed in the Tc location, i.e. the temperature is constant through the flow cross-section area. The present evaluations by using the FLUENT 5.5.14 code reveal that, this assumption is not fulfilled. There exists a temperature profile that depends on fuel assembly geometry and on inner power profile of the fuel assembly. The paper presents the estimation of this effect and its influence on the core power distribution and the core by-pass flow determination. Comparison with measurements in Mochovce NPP will also be a part of this presentation (Authors)

  12. Analysis of chiller units capacity for different heat loads considering variation of ambient air and cooling water temperature

    International Nuclear Information System (INIS)

    Coman, Aurelia Camelia; Tenescu, Mircea

    2010-01-01

    The paper purpose is to analyze the chiller units capacity to determine whether they can cope with high air and cooling water temperatures during summer time to remove heat loads imposed from Heating, Ventilation and Air Conditioning (HVAC) units in a CANDU 6 Nuclear Power Plant. The starting point is calculation of the overall heat transfer coefficient at the evaporator and condenser. They are used in heat balance equations of heat exchangers. A mathematical model was developed that simulates the refrigeration cycle to assess the response of chilled water system and its performance at different heat loads. In this analysis there were calculated values for inlet/outlet chilled water temperature and the refrigerant cycle thermodynamic parameters (condenser and evaporator pressure/temperature, refrigerant mass flowrate, refrigerant quality at the evaporator, refrigerant vapour superheated temperature at the compressor outlet, refrigerant subcooled temperature at the condenser outlet). To find the adequate functioning parameters of the installation, the MathCAD 13 software was used in all cases analyzed. The behaviour of the chiller units was investigated by examining the variation of three basic parameters, namely: - cooling water (river water) temperature; - air temperature; - heat load. The simultaneous variation of these three independent parameters allows to identify the actual chillers unit operating point (including chiller trip). (authors)

  13. Searching for storm water inflows in foul sewers using fibre-optic distributed temperature sensing.

    Science.gov (United States)

    Schilperoort, Rémy; Hoppe, Holger; de Haan, Cornelis; Langeveld, Jeroen

    2013-01-01

    A major drawback of separate sewer systems is the occurrence of illicit connections: unintended sewer cross-connections that connect foul water outlets from residential or industrial premises to the storm water system and/or storm water outlets to the foul sewer system. The amount of unwanted storm water in foul sewer systems can be significant, resulting in a number of detrimental effects on the performance of the wastewater system. Efficient removal of storm water inflows into foul sewers requires knowledge of the exact locations of the inflows. This paper presents the use of distributed temperature sensing (DTS) monitoring data to localize illicit storm water inflows into foul sewer systems. Data results from two monitoring campaigns in foul sewer systems in the Netherlands and Germany are presented. For both areas a number of storm water inflow locations can be derived from the data. Storm water inflow can only be detected as long as the temperature of this inflow differs from the in-sewer temperatures prior to the event. Also, the in-sewer propagation of storm and wastewater can be monitored, enabling a detailed view on advection.

  14. Monitoring of tritium, 60Co and 137Cs in the vicinity of the warm water outlet of the Paks Nuclear Power Plant, Hungary.

    Science.gov (United States)

    Janovics, R; Bihari, Á; Papp, L; Dezső, Z; Major, Z; Sárkány, K E; Bujtás, T; Veres, M; Palcsu, L

    2014-02-01

    Danube water, sediment and various aquatic organisms (snail, mussel, predatory and omnivorous fish) were collected upstream (at a background site) and downstream of the outlet of the warm water channel of Paks Nuclear Power Plant. Gamma emitters, tissue free-water tritium (TFWT) and total organically-bound tritium (T-OBT) measurements were performed. A slight contribution of the power plant to the natural tritium background concentration was measured in water samples from the Danube section downstream of the warm water channel. Sediment samples also contained elevated tritium concentrations, along with a detectable amount of (60)Co. In the case of biota samples, TFWT exhibited only a very slight difference compared to the tritium concentration of the Danube water, however, the OBT was higher than the tritium concentration in the Danube, independent of the origin of the samples. The elevated OBT concentration in the mollusc samples downstream of the warm water channel may be attributed to the excess emission from the nuclear power plant. The whole data set obtained was used for dose rate calculations and will be contributed to the development of the ERICA database. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Experimental Investigation of a Mechanical Vapour Compression Chiller at Elevated Chilled Water Temperatures

    KAUST Repository

    Thu, Kyaw

    2017-05-18

    The performance of a Mechanical Vapour Compression (MVC) chiller is experimentally investigated under operating conditions suitable for sensible cooling. With the emergence of the energy efficient dehumidification systems, it is possible to decouple the latent load from the MVC chillers which can be operated at higher chilled water temperature for handling sensible cooling load. In this article, the performance of the chiller is evaluated at the elevated chilled water outlet temperatures (7 – 17° C) at various coolant temperatures (28 – 32° C) and flow rates (ΔT = 4 and 5° C) for both full- and part-load conditions. Keeping the performance at the AHRI standard as the baseline condition, the efficacy of the chiller in terms of compression ratio, cooling capacity and COP at aforementioned conditions is quantified experimentally. It is observed that for each one-degree Celsius increase in the chilled water temperature, the COP of the chiller improves by about 3.5% whilst the cooling capacity improvement is about 4%. For operation at 17° C chilled water outlet temperature, the improvements in COP and cooling capacity are between 37 – 40% and 40 – 45%, respectively, compared to the performance at the AHRI standards. The performance of the MVC chiller at the abovementioned operation conditions is mapped on the chiller performance characteristic chart.

  16. Experimental Investigation of a Mechanical Vapour Compression Chiller at Elevated Chilled Water Temperatures

    KAUST Repository

    Thu, Kyaw; Saththasivam, Jayaprakash; Saha, Bidyut Baran; Chua, Kian Jon; Srinivasa Murthy, S.; Ng, Kim Choon

    2017-01-01

    The performance of a Mechanical Vapour Compression (MVC) chiller is experimentally investigated under operating conditions suitable for sensible cooling. With the emergence of the energy efficient dehumidification systems, it is possible to decouple the latent load from the MVC chillers which can be operated at higher chilled water temperature for handling sensible cooling load. In this article, the performance of the chiller is evaluated at the elevated chilled water outlet temperatures (7 – 17° C) at various coolant temperatures (28 – 32° C) and flow rates (ΔT = 4 and 5° C) for both full- and part-load conditions. Keeping the performance at the AHRI standard as the baseline condition, the efficacy of the chiller in terms of compression ratio, cooling capacity and COP at aforementioned conditions is quantified experimentally. It is observed that for each one-degree Celsius increase in the chilled water temperature, the COP of the chiller improves by about 3.5% whilst the cooling capacity improvement is about 4%. For operation at 17° C chilled water outlet temperature, the improvements in COP and cooling capacity are between 37 – 40% and 40 – 45%, respectively, compared to the performance at the AHRI standards. The performance of the MVC chiller at the abovementioned operation conditions is mapped on the chiller performance characteristic chart.

  17. Impact of PAH [Polycyclic Aromatic Hydrocarbons] outlets from an oil refinery on the receiving water area - sediment trap fluxes and multivariate statistical analysis

    International Nuclear Information System (INIS)

    Pettersen, Harald; Naef, Carina; Broman, Dag

    1997-01-01

    PAH concentrations (15 compounds) in settling particulate matter (SPM) collected in the waters outside a petroleum refinery on the Swedish Baltic coast, and in samples of particulate and dissolved fractions in the wastewater from the refinery were determined. SPM concentrations varied between 550 and 4250 ng x gdw -1 and the corresponding calculated fluxes varied between 0.1 and 3.7 ng x cm -2 x day -1 . Both concentrations and fluxes did not differ significantly from background coastal or offshore locations in the Baltic. PAH profiles of the SPM samples were compared with the wastewater samples and SPM samples from background areas in the Baltic, using pattern recognition techniques. This analysis showed that the SPM samples from the petroleum refinery displayed a PAH composition similar to that found in background reference sites in the Baltic, and that the SPM samples could not be connected to the wastewater samples from the refinery. This indicates that Nynas AB is not a significant source of PAHs to the waters in its immediate surroundings, i.e. the waters in the Nynashamn area, and/or that the hydraulic residence time of the water outside the refinery is low. A budget calculation showed that the wastewater outlet from Nynas AB is only a minor contributor of the PAH load to the waters outside the refinery. (Author)

  18. Water temperature effects from simulated changes to dam operations and structures in the Middle and South Santiam Rivers, Oregon

    Science.gov (United States)

    Buccola, Norman L.

    2017-05-31

    Green Peter and Foster Dams on the Middle and South Santiam Rivers, Oregon, have altered the annual downstream water temperature profile (cycle). Operation of the dams has resulted in cooler summer releases and warmer autumn releases relative to pre-dam conditions, and that alteration can hinder recovery of various life stages of threatened spring-run Chinook salmon (Oncorhyncus tshawytscha) and winter steelhead (O. mykiss). Lake level management and the use of multiple outlets from varying depths at the dams can enable the maintenance of a temperature regime more closely resembling that in which the fish evolved by releasing warm surface water during summer and cooler, deeper water in the autumn. At Green Peter and Foster Dams, the outlet configuration is such that temperature control is often limited by hydropower production at the dams. Previously calibrated CE-QUAL-W2 water temperature models of Green Peter and Foster Lakes were used to simulate the downstream thermal effects from hypothetical structures and modified operations at the dams. Scenarios with no minimum power production requirements allowed some releases through shallower and deeper outlets (summer and autumn) to achieve better temperature control throughout the year and less year-to-year variability in autumn release temperatures. Scenarios including a hypothetical outlet floating 1 meter below the lake surface resulted in greater ability to release warm water during summer compared to existing structures. Later in Autumn (October 15–December 31), a limited amount of temperature control was realized downstream from Foster Dam by scenarios limited to operational changes with existing structures, resulting in 15-day averages within 1.0 degree Celsius of current operations.

  19. Searching for storm water inflows in foul sewers using fibre-optic distributed temperature sensing

    NARCIS (Netherlands)

    Schilperoort, R.; Hoppe, H.; Haan, C.; Langeveld, J.G.

    2012-01-01

    A major drawback of separate sewer systems is the occurrence of illicit connections: unintended sewer cross-connections that connect foul water outlets from residential or industrial premises to the storm water system and/or storm water outlets to the foul sewer system. The amount of unwanted storm

  20. High temperature pressure water's blowdown into water. Experimental results

    International Nuclear Information System (INIS)

    Ishida, Toshihisa; Kusunoki, Tsuyoshi; Kasahara, Yoshiyuki; Iida, Hiromasa

    1994-01-01

    The purpose of the present experimental study is to clarify the phenomena in blowdown of high temperature and pressure water in pressure vessel into the containment water for evaluation of design of an advanced marine reactor(MRX). The water blown into the containment water flushed and formed steam jet plume. The steam jet condensed in the water, but some stream penetrated to gas phase of containment and contributed to increase of containment pressure. (author)

  1. High temperature and high performance light water cooled reactors operating at supercritical pressure, research and development

    International Nuclear Information System (INIS)

    Oka, Y.; Koshizuka, S.; Katsumura, Y.; Yamada, K.; Shiga, S.; Moriya, K.; Yoshida, S.; Takahashi, H.

    2003-01-01

    The concept of supercritical-pressure, once-through coolant cycle nuclear power plant (SCR) was developed at the University of Tokyo. The research and development (R and D) started worldwide. This paper summarized the conceptual design and R and D in Japan. The big advantage of the SCR concept is that the temperatures of major components such as reactor pressure vessel, control rod drive mechanisms, containments, coolant pumps, main steam piping and turbines are within the temperatures of the components of LWR and supercritical fossil fired power plants (FPP) in spite of the high outlet coolant temperature. The experience of these components of LWR and supercritical fossil fired power plants will be fully utilized for SCR. The high temperature, supercritical-pressure light water reactor is the logical evolution of LWR. Boiling evolved from circular boilers, water tube boilers and once-through boilers. It is the reactor version of the once-through boiler. The development from LWR to SCR follows the history of boilers. The goal of the R and D should be the capital cost reduction that cannot be achieved by the improvement of LWR. The reactor can be used for hydrogen production either by catalysis and chemical decomposition of low quality hydrocarbons in supercritical water. The reactor is compatible with tight lattice fast core for breeders due to low outlet coolant density, small coolant flow rate and high head coolant pumps

  2. The influence of river water temperature annual variation to the moderator heat exchangers heat flux

    International Nuclear Information System (INIS)

    Nita, I. P.

    2015-01-01

    The Main Moderator heat exchangers are the most important consumers supplied by Recirculated Cooling Water (RCW) System. In order to determine an appropriate operating configuration of the RCW system it is needed to determine the flowrate required by the Main Moderator consumers, in real time. From operating experience, the required RCW flowrate necessary to be supplied to the main moderator heat exchangers is much lower than design flowrate. In installation, there are no flow elements that could measure especially that flow. However, there are two control valves which regulate the flow to the main moderator heaters; they control the outlet temperature of the moderator to 69"oC. That leads to the requirement of calculating the flowrate function of the outside temperature for all possible temperatures during a calendar year. One considered all possible temperatures during an operating year, and more, going beyond design point, up to 36"oC, temperature that can occur during quick transients after forth RCW pump starting. The calculation was made to verify the capacity of heat exchanger to remove the designed 100 MW(t) in the new condition of reducing moderator temperature outlet from 77 to 69°C. The obtained model was validated using field temperatures and flow measurements and the conclusion was the model can accurately predict how the RCW system operates in all year operation conditions. (authors)

  3. Relationship between water temperature predictability and aquatic ...

    African Journals Online (AJOL)

    Macroinvertebrate taxonomic turnover across seasons was higher for sites having lower water temperature predictability values than for sites with higher predictability, while temporal partitioning was greater at sites with greater temperature variability. Macroinvertebrate taxa responded in a predictable manner to changes in ...

  4. PPOOLEX experiments with a modified blowdown pipe outlet

    International Nuclear Information System (INIS)

    Laine, J.; Puustinen, M.; Raesaenen, A.

    2009-08-01

    This report summarizes the results of the experiments with a modified blowdown pipe outlet carried out with the PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through a vertical DN200 blowdown pipe to the condensation pool. Four reference experiments with a straight pipe and ten with the Forsmark type collar were carried out. The main purpose of the experiment series was to study the effect of a blowdown pipe outlet collar design on loads caused by chugging phenomena (rapid condensation) while steam is discharged into the condensation pool. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. During the experiments the initial temperature level of the condensation pool water was either 20-25 or 50-55 deg. C. The steam flow rate varied from 400 to 1200 g/s and the temperature of incoming steam from 142 to 185 deg. C. In the experiments with 20-25 deg. C pool water, even 10 times higher pressure pulses were measured inside the blowdown pipe in the case of the straight pipe than with the collar. In this respect, the collar design worked as planned and removed the high pressure spikes from the blowdown pipe. Meanwhile, there seemed to be no suppressing effect on the loads due to the collar in the pool side in this temperature range. Registered loads in the pool were approximately in the same range (or even a little higher) with the collar as with the straight pipe. In the experiments with 50-55 deg. C pool water no high pressure pulses were measured inside the blowdown pipe either with the straight pipe or with the collar. In this case, more of the suppressing effect is probably due to the warmer pool water than due to the modified pipe outlet. It has been observed already in the earlier experiments with a straight pipe in the POOLEX and PPOOLEX facilities that warm pool water has a diminishing effect on

  5. PPOOLEX experiments with a modified blowdown pipe outlet

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Puustinen, M.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2009-08-15

    This report summarizes the results of the experiments with a modified blowdown pipe outlet carried out with the PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. Steam was blown into the dry well compartment and from there through a vertical DN200 blowdown pipe to the condensation pool. Four reference experiments with a straight pipe and ten with the Forsmark type collar were carried out. The main purpose of the experiment series was to study the effect of a blowdown pipe outlet collar design on loads caused by chugging phenomena (rapid condensation) while steam is discharged into the condensation pool. The PPOOLEX test facility is a closed stainless steel vessel divided into two compartments, dry well and wet well. During the experiments the initial temperature level of the condensation pool water was either 20-25 or 50-55 deg. C. The steam flow rate varied from 400 to 1200 g/s and the temperature of incoming steam from 142 to 185 deg. C. In the experiments with 20-25 deg. C pool water, even 10 times higher pressure pulses were measured inside the blowdown pipe in the case of the straight pipe than with the collar. In this respect, the collar design worked as planned and removed the high pressure spikes from the blowdown pipe. Meanwhile, there seemed to be no suppressing effect on the loads due to the collar in the pool side in this temperature range. Registered loads in the pool were approximately in the same range (or even a little higher) with the collar as with the straight pipe. In the experiments with 50-55 deg. C pool water no high pressure pulses were measured inside the blowdown pipe either with the straight pipe or with the collar. In this case, more of the suppressing effect is probably due to the warmer pool water than due to the modified pipe outlet. It has been observed already in the earlier experiments with a straight pipe in the POOLEX and PPOOLEX facilities that warm pool water has a diminishing effect on

  6. Water temperature impacts water consumption by range cattle in winter

    Science.gov (United States)

    Water consumption and DMI have been found to be positively correlated, which may interact with ingestion of cold water or grazed frozen forage due to transitory reductions in temperature of ruminal contents. The hypothesis underpinning the study explores the potential that cows provided warm drinkin...

  7. Identify the dominant variables to predict stream water temperature

    Science.gov (United States)

    Chien, H.; Flagler, J.

    2016-12-01

    Stream water temperature is a critical variable controlling water quality and the health of aquatic ecosystems. Accurate prediction of water temperature and the assessment of the impacts of environmental variables on water temperature variation are critical for water resources management, particularly in the context of water quality and aquatic ecosystem sustainability. The objective of this study is to measure stream water temperature and air temperature and to examine the importance of streamflow on stream water temperature prediction. The measured stream water temperature and air temperature will be used to test two hypotheses: 1) streamflow is a relatively more important factor than air temperature in regulating water temperature, and 2) by combining air temperature and streamflow data stream water temperature can be more accurately estimated. Water and air temperature data loggers are placed at two USGS stream gauge stations #01362357and #01362370, located in the upper Esopus Creek watershed in Phonecia, NY. The ARIMA (autoregressive integrated moving average) time series model is used to analyze the measured water temperature data, identify the dominant environmental variables, and predict the water temperature with identified dominant variable. The preliminary results show that streamflow is not a significant variable in predicting stream water temperature at both USGS gauge stations. Daily mean air temperature is sufficient to predict stream water temperature at this site scale.

  8. Temperature transient response measurement in flowing water

    International Nuclear Information System (INIS)

    Rainbird, J.C.

    1980-01-01

    A specially developed procedure is described for determining the thermal transient response of thermocouples and other temperature transducers when totally immersed in flowing water. The high velocity heat transfer conditions associated with this facility enable thermocouple response times to be predicted in other fluids. These predictions can be confirmed by electrical analogue experiments. (author)

  9. Escherichia coli survival in waters: Temperature dependence

    Science.gov (United States)

    Knowing the survival rates of water-borne Escherichia coli is important in evaluating microbial contamination and making appropriate management decisions. E. coli survival rates are dependent on temperature, a dependency that is routinely expressed using an analogue of the Q10 mo...

  10. STUDI PENENTUAN JENIS OUTLET LIMBAH CAIR KARET REMAH UNTUK PERTUMBUHAN MIKROALGA DENGAN SISTEM OPEN PONDS [Study of determination the type of crumb rubber waste water outlet for the growth of microalgae with open ponds system

    OpenAIRE

    Tanto Pratondo Utomo; Otik Nawansih; Anggun KOmalasari

    2015-01-01

    Waste water of crumb rubber industry is originated from coagulation, milling and leaching stage contains organic material that is derived from serum and rubber particles which haven’t been coagulated yet. The materials are potential to pollute the water therefore the crumb rubber industry must be treated through the wastewater plant. However, the characteristics of waste water are predicted suitable for the cultivation of Nannochloropsis sp. media a biofuel feedstock, especially biodiesel tha...

  11. High temperature measurement of water vapor absorption

    Science.gov (United States)

    Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

    1985-01-01

    An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

  12. The sublethal effects of zinc at different water temperatures on ...

    African Journals Online (AJOL)

    The sublethal effects of zinc at different water temperatures on selected ... of 96h at different water temperatures representing the seasonal temperatures in the ... are mobilised to meet increased energy demands during periods of stress.

  13. Operational efficiency of ballast water biocides at low water temperatures

    NARCIS (Netherlands)

    Kaag, N.H.B.M.; Sneekes, A.C.

    2015-01-01

    In the period 2013-2015 the effect of two biocides used for the treatment of ballast water has been evaluated at low ambient temperatures. Peraclean® Ocean and sodium hypochlorite were used as biocides. Most of the tests were conducted during winter and early spring at the laboratories of IMARES in

  14. Zircaloy behaviour in high temperature irradiated water

    International Nuclear Information System (INIS)

    Urbanic, V.F.

    1982-04-01

    The corrosion and hydriding of Zircaloy during irradiation in high temperature water is strongly dependent on the oxygen concentration of the water. Corrosion tests in the NRX and NRU research reactors using small samples have demonstrated the importance of water chemistry in maintaining Zircaloy corrosion and hydriding within acceptable limits. Zircaloy fuel cladding develops non-uniform, patch-type oxides during irradiation in hich temperature water containing dissolved oxygen. Results from examinations of prototype fuel cladding irradiated in the research reactors are presented to show how local variations in coolant flow, fast neutron flux, metallurgical structure and surface condition can influence the onset of non-uniform corrosion under these conditions. Destructive examinations of CANDU-PHW reactor fuel cladding have emphasized the importance of good chemistry control, especially the dissolved oxygen concentration of the water. When reactor coolants are maintained under normal reducing conditions at high pH (5 to 10 cm 3 D 2 /kg D 2 O; 2 /kg D 2 O; pH > 10 with LiOD), Zircaloy cladding develops non-uniform, patch-type oxides. These patch-type oxides tend to coalesce with time to form a thick, uniform oxide layer after extended exposure. Under reducing coolant conditions, Zircaloy cladding absorbs less than 200 mg D/kg Zr (approximately 2.5 mg/dm 2 equivalent hydrogen) in about 500 days. With oxygen in the coolant, deuterium absorption is considerably less despite the significant increase in corrosion under such conditions

  15. PEM Water Electrolysis at Elevated Temperatures

    DEFF Research Database (Denmark)

    Hansen, Martin Kalmar

    . This is followed in chapter 4 by a description of the electrolysis setups and electrolysis cells used during the work. Two different setups were used, one operating at atmospheric pressure and another that could operate at elevated pressure so that liquid water electrolysis could be performed at temperature above...... such as porosity and resistance which were supported by images acquired using scanning electron microscopy (SEM). In chapters 6 and 7 the results of the steam electrolysis and pressurised water electrolysis, respectively, are presented and discussed. The steam electrolysis was tested at 130 °C and atmospheric...... needed and hence it has become acute to be able to store the energy. Hydrogen has been identified as a suitable energy carrier and water electrolysis is one way to produce it in a sustainable and environmentally friendly way. In this thesis an introduction to the subject (chapter 1) is given followed...

  16. Storm-induced water dynamics and thermohaline structure at the tidewater Flade Isblink Glacier outlet to the Wandel Sea (NE Greenland)

    Science.gov (United States)

    Kirillov, Sergei; Dmitrenko, Igor; Rysgaard, Søren; Babb, David; Toudal Pedersen, Leif; Ehn, Jens; Bendtsen, Jørgen; Barber, David

    2017-11-01

    In April 2015, an ice-tethered conductivity-temperature-depth (CTD) profiler and a down-looking acoustic Doppler current profiler (ADCP) were deployed from the landfast ice near the tidewater glacier terminus of the Flade Isblink Glacier in the Wandel Sea, NE Greenland. The 3-week time series showed that water dynamics and the thermohaline structure were modified considerably during a storm event on 22-24 April, when northerly winds exceeded 15 m s-1. The storm initiated downwelling-like water dynamics characterized by on-shore water transport in the surface (0-40 m) layer and compensating offshore flow at intermediate depths. After the storm, currents reversed in both layers, and the relaxation phase of downwelling lasted ˜ 4 days. Although current velocities did not exceed 5 cm s-1, the enhanced circulation during the storm caused cold turbid intrusions at 75-95 m depth, which are likely attributable to subglacial water from the Flade Isblink Ice Cap. It was also found that the semidiurnal periodicities in the temperature and salinity time series were associated with the lunar semidiurnal tidal flow. The vertical structure of tidal currents corresponded to the first baroclinic mode of the internal tide with a velocity minimum at ˜ 40 m. The tidal ellipses rotate in opposite directions above and below this depth and cause a divergence of tidal flow, which was observed to induce semidiurnal internal waves of about 3 m height at the front of the glacier terminus. Our findings provide evidence that shelf-basin interaction and tidal forcing can potentially modify coastal Wandel Sea waters even though they are isolated from the atmosphere by landfast sea ice almost year-round. The northerly storms over the continental slope cause an enhanced circulation facilitating a release of cold and turbid subglacial water to the shelf. The tidal flow may contribute to the removal of such water from the glacial terminus.

  17. Water in Room Temperature Ionic Liquids

    Science.gov (United States)

    Fayer, Michael

    2014-03-01

    Room temperature ionic liquids (or RTILs, salts with a melting point below 25 °C) have become a subject of intense study over the last several decades. Currently, RTIL application research includes synthesis, batteries, solar cells, crystallization, drug delivery, and optics. RTILs are often composed of an inorganic anion paired with an asymmetric organic cation which contains one or more pendant alkyl chains. The asymmetry of the cation frustrates crystallization, causing the salt's melting point to drop significantly. In general, RTILs are very hygroscopic, and therefore, it is of interest to examine the influence of water on RTIL structure and dynamics. In addition, in contrast to normal aqueous salt solutions, which crystallize at low water concentration, in an RTIL it is possible to examine isolated water molecules interacting with ions but not with other water molecules. Here, optical heterodyne-detected optical Kerr effect (OHD-OKE) measurements of orientational relaxation on a series of 1-alkyl-3-methylimidazolium tetrafluoroborate RTILs as a function of chain length and water concentration are presented. The addition of water to the longer alkyl chain RTILs causes the emergence of a long time bi-exponential orientational anisotropy decay. Such decays have not been seen previously in OHD-OKE experiments on any type of liquid and are analyzed here using a wobbling-in-a-cone model. The orientational relaxation is not hydrodynamic, with the slowest relaxation component becoming slower as the viscosity decreases for the longest chain, highest water content samples. The dynamics of isolated D2O molecules in 1-butyl-3-methylimidazolium hexafluorophosphate (BmImPF6) were examined using two dimensional infrared (2D IR) vibrational echo spectroscopy. Spectral diffusion and incoherent and coherent transfer of excitation between the symmetric and antisymmetric modes are examined. The coherent transfer experiments are used to address the nature of inhomogeneous

  18. Conceptual design of a high temperature water-cooled divertor for a fusion power reactor

    International Nuclear Information System (INIS)

    Giancarli, L.; Bonal, J.P.; Puma, A. Li; Michel, B.; Sardain, P.; Salavy, J.F.

    2005-01-01

    This paper presents the conceptual design of a water-cooled divertor target using EUROFER as structural material, water coolant pressure and outlet temperature, respectively, of 15.5 MPa and 325 o C, and W-alloy monoblocks as armour. Assuming an advanced interface, formed by a thermal barrier in the pipe front part and a compliance layer between W and steel, this concept is able to withstand an incident surface heat flux of 15 MW/m 2 . Both thermal barrier and compliance layer are made of carbon-based materials. The main issues are the manufacturing process of the steel/W interface, and the behaviour under irradiation of graphite materials

  19. Conceptual design of a high temperature water-cooled divertor for a fusion power reactor

    Energy Technology Data Exchange (ETDEWEB)

    Giancarli, L. [CEA Saclay, Direction de l' Energie Nucleaire, F-91191 Gif-sur-Yvette (France)]. E-mail: luciano.giancarli@cea.fr; Bonal, J.P. [CEA Saclay, Direction de l' Energie Nucleaire, F-91191 Gif-sur-Yvette (France); Puma, A. Li [CEA Saclay, Direction de l' Energie Nucleaire, F-91191 Gif-sur-Yvette (France); Michel, B. [CEA Cadarache, Direction de l' Energie Nucleaire, F-13108 St. Paul-les-Durances (France); Sardain, P. [EFDA Close Support Unit, Boltzmannstr. 2, D-85748 Garching (Germany); Salavy, J.F. [CEA Saclay, Direction de l' Energie Nucleaire, F-91191 Gif-sur-Yvette (France)

    2005-11-15

    This paper presents the conceptual design of a water-cooled divertor target using EUROFER as structural material, water coolant pressure and outlet temperature, respectively, of 15.5 MPa and 325 {sup o}C, and W-alloy monoblocks as armour. Assuming an advanced interface, formed by a thermal barrier in the pipe front part and a compliance layer between W and steel, this concept is able to withstand an incident surface heat flux of 15 MW/m{sup 2}. Both thermal barrier and compliance layer are made of carbon-based materials. The main issues are the manufacturing process of the steel/W interface, and the behaviour under irradiation of graphite materials.

  20. Estimation of paddy water temperature during crop development

    International Nuclear Information System (INIS)

    Centeno, H.G.S.; Horie, T.

    1996-01-01

    The crop meristem is in direct contact with paddy water during crop's vegetative stage. Ambient air temperature becomes an important factor in crop development only when internodes elongate sufficiently for the meristem to rise above the water surface. This does not occur until after panicle initiation. Crop growth at vegetative stage is affected more by water temperature than the most commonly measured air temperature. During transplanting in 1992 dry season, the maximum paddy water temperature was 10 deg C higher than the maximum air temperature. For rice crop models, the development of a submodel to estimate water temperature is important to account the effect of paddy water temperature on plant growth. Paddy water temperature is estimated from mean air temperature, solar radiation, and crop canopy. The parameters of the model were derived using the simplex method on data from the 1993 wet- and dry-season field experiments at IRRI

  1. Storm-induced water dynamics and thermohaline structure at the tidewater Flade Isblink Glacier outlet to theWandel Sea (NE Greenland)

    DEFF Research Database (Denmark)

    Kirillov, Sergei; Dmitrenko, Igor; Rysgaard, Soren

    2017-01-01

    In April 2015, an ice-tethered conductivity-temperature-depth (CTD) profiler and a down-looking acoustic Doppler current profiler (ADCP) were deployed from the landfast ice near the tidewater glacier terminus of the Flade Isblink Glacier in the Wandel Sea, NE Greenland. The 3-week time series...... are likely attributable to subglacial water from the Flade Isblink Ice Cap. It was also found that the semidiurnal periodicities in the temperature and salinity time series were associated with the lunar semidiurnal tidal flow. The vertical structure of tidal currents corresponded to the first baroclinic...... mode of the internal tide with a velocity minimum at similar to 40 m. The tidal ellipses rotate in opposite directions above and below this depth and cause a divergence of tidal flow, which was observed to induce semidiurnal internal waves of about 3 m height at the front of the glacier terminus...

  2. Calculation of gas temperature at the outlet of the combustion chamber and in the air-gas channel of a gas-turbine unit by data of acceptance tests in accordance with ISO

    Science.gov (United States)

    Kostyuk, A. G.; Karpunin, A. P.

    2016-01-01

    This article describes a high accuracy method enabling performance of the calculation of real values of the initial temperature of a gas turbine unit (GTU), i.e., the gas temperature at the outlet of the combustion chamber, in a situation where manufacturers do not disclose this information. The features of the definition of the initial temperature of the GTU according to ISO standards were analyzed. It is noted that the true temperatures for high-temperature GTUs is significantly higher than values determined according to ISO standards. A computational procedure for the determination of gas temperatures in the air-gas channel of the gas turbine and cooling air consumptions over blade rims is proposed. As starting equations, the heat balance equation and the flow mixing equation for the combustion chamber are assumed. Results of acceptance GTU tests according to ISO standards and statistical dependencies of required cooling air consumptions on the gas temperature and the blade metal are also used for calculations. An example of the calculation is given for one of the units. Using a developed computer program, the temperatures in the air-gas channel of certain GTUs are calculated, taking into account their design features. These calculations are performed on the previously published procedure for the detailed calculation of the cooled gas turbine subject to additional losses arising because of the presence of the cooling system. The accuracy of calculations by the computer program is confirmed by conducting verification calculations for the GTU of the Mitsubishi Comp. and comparing results with published data of the company. Calculation data for temperatures were compared with the experimental data and the characteristics of the GTU, and the error of the proposed method is estimated.

  3. 21 CFR 880.5560 - Temperature regulated water mattress.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Temperature regulated water mattress. 880.5560... Therapeutic Devices § 880.5560 Temperature regulated water mattress. (a) Identification. A temperature regulated water mattress is a device intended for medical purposes that consists of a mattress of suitable...

  4. Storm-induced water dynamics and thermohaline structure at the tidewater Flade Isblink Glacier outlet to the Wandel Sea (NE Greenland

    Directory of Open Access Journals (Sweden)

    S. Kirillov

    2017-11-01

    Full Text Available In April 2015, an ice-tethered conductivity–temperature–depth (CTD profiler and a down-looking acoustic Doppler current profiler (ADCP were deployed from the landfast ice near the tidewater glacier terminus of the Flade Isblink Glacier in the Wandel Sea, NE Greenland. The 3-week time series showed that water dynamics and the thermohaline structure were modified considerably during a storm event on 22–24 April, when northerly winds exceeded 15 m s−1. The storm initiated downwelling-like water dynamics characterized by on-shore water transport in the surface (0–40 m layer and compensating offshore flow at intermediate depths. After the storm, currents reversed in both layers, and the relaxation phase of downwelling lasted ∼ 4 days. Although current velocities did not exceed 5 cm s−1, the enhanced circulation during the storm caused cold turbid intrusions at 75–95 m depth, which are likely attributable to subglacial water from the Flade Isblink Ice Cap. It was also found that the semidiurnal periodicities in the temperature and salinity time series were associated with the lunar semidiurnal tidal flow. The vertical structure of tidal currents corresponded to the first baroclinic mode of the internal tide with a velocity minimum at ∼ 40 m. The tidal ellipses rotate in opposite directions above and below this depth and cause a divergence of tidal flow, which was observed to induce semidiurnal internal waves of about 3 m height at the front of the glacier terminus. Our findings provide evidence that shelf–basin interaction and tidal forcing can potentially modify coastal Wandel Sea waters even though they are isolated from the atmosphere by landfast sea ice almost year-round. The northerly storms over the continental slope cause an enhanced circulation facilitating a release of cold and turbid subglacial water to the shelf. The tidal flow may contribute to the removal of such water from the glacial terminus.

  5. Water temperature issues in the 90's and beyond

    International Nuclear Information System (INIS)

    Railsback, S.F.

    1993-01-01

    Water temperature issues are expected to receive increasing attention in the 1990s. Temperature impacts are among the most common and most expensive environmental issues requiring mitigation at water projects, but few changes in mitigation technologies and little research have occurred in the past decade. Water projects alter water temperatures because the heat balances in reservoirs and in streams with altered flows are significantly different from natural. Several emerging environmental and regulatory concerns and issues are likely to focus additional attention on temperature. Climate change, should it occur as predicted, can be expected to worsen many water temperature problems and complicate the determination of appropriate mitigation for water projects. The purposes of this paper are to review current water temperature issues and mitigation methods, to identify new and future temperature issues, and to identify research needs

  6. Water temperature effects from simulated dam operations and structures in the Middle Fork Willamette River, western Oregon

    Science.gov (United States)

    Buccola, Norman L.; Turner, Daniel F.; Rounds, Stewart A.

    2016-09-14

    Significant FindingsStreamflow and water temperature in the Middle Fork Willamette River (MFWR), western Oregon, have been regulated and altered since the construction of Lookout Point, Dexter, and Hills Creek Dams in 1954 and 1961, respectively. Each year, summer releases from the dams typically are cooler than pre-dam conditions, with the reverse (warmer than pre-dam conditions) occurring in autumn. This pattern has been detrimental to habitat of endangered Upper Willamette River (UWR) Chinook salmon (Oncorhynchus tshawytscha) and UWR winter steelhead (O. mykiss) throughout multiple life stages. In this study, scenarios testing different dam-operation strategies and hypothetical dam-outlet structures were simulated using CE-QUAL-W2 hydrodynamic/temperature models of the MFWR system from Hills Creek Lake (HCR) to Lookout Point (LOP) and Dexter (DEX) Lakes to explore and understand the efficacy of potential flow and temperature mitigation options.Model scenarios were run in constructed wet, normal, and dry hydrologic calendar years, and designed to minimize the effects of Hills Creek and Lookout Point Dams on river temperature by prioritizing warmer lake surface releases in May–August and cooler, deep releases in September–December. Operational scenarios consisted of a range of modified release rate rules, relaxation of power-generation constraints, variations in the timing of refill and drawdown, and maintenance of different summer maximum lake levels at HCR and LOP. Structural scenarios included various combinations of hypothetical floating outlets near the lake surface and hypothetical new outlets at depth. Scenario results were compared to scenarios using existing operational rules that give temperature management some priority (Base), scenarios using pre-2012 operational rules that prioritized power generation over temperature management (NoBlend), and estimated temperatures from a without-dams condition (WoDams).Results of the tested model scenarios led

  7. Effects of air temperature and discharge on Upper Mississippi River summer water temperatures

    Science.gov (United States)

    Gray, Brian R.; Robertson, Dale M.; Rogala, James T.

    2018-01-01

    Recent interest in the potential effects of climate change has prompted studies of air temperature and precipitation associations with water temperatures in rivers and streams. We examined associations between summer surface water temperatures and both air temperature and discharge for 5 reaches of the Upper Mississippi River during 1994–2011. Water–air temperature associations at a given reach approximated 1:1 when estimated under an assumption of reach independence but declined to approximately 1:2 when water temperatures were permitted to covary among reaches and were also adjusted for upstream air temperatures. Estimated water temperature–discharge associations were weak. An apparently novel feature of this study is that of addressing changes in associations between water and air temperatures when both are correlated among reaches.

  8. Thermal infrared remote sensing of water temperature in riverine landscapes

    Science.gov (United States)

    Handcock, Rebecca N.; Torgersen, Christian E.; Cherkauer, Keith A.; Gillespie, Alan R.; Klement, Tockner; Faux, Russell N.; Tan, Jing; Carbonneau, Patrice E.; Piégay, Hervé

    2012-01-01

    Water temperature in riverine landscapes is an important regional indicator of water quality that is influenced by both ground- and surface-water inputs, and indirectly by land use in the surrounding watershed (Brown and Krygier, 1970; Beschta et al., 1987; Chen et al., 1998; Poole and Berman, 2001).Coldwater fishes such as salmon and trout are sensitive to elevated water temperature; therefore, water temperature must meet management guidelines and quality standards, which aim to create a healthy environment for endangered populations (McCullough et al., 2009). For example, in the USA, the Environmental Protection Agency (EPA) has established water quality standards to identify specific temperature criteria to protect coldwater fishes (Environmental Protection Agency, 2003). Trout and salmon can survive in cool-water refugia even when temperatures at other measurement locations are at or above the recommended maximums (Ebersole et al., 2001; Baird and Krueger, 2003; High et al., 2006). Spatially extensive measurements of water temperature are necessary to locate these refugia, to identify the location of ground- and surface-water inputs to the river channel, and to identify thermal pollution sources. Regional assessment of water temperature in streams and rivers has been limited by sparse sampling in both space and time. Water temperature has typically been measured using a network of widely distributed instream gages, which record the temporal change of the bulk, or kinetic, temperature of the water (Tk) at specific locations. For example, the State of Washington (USA) recorded water quality conditions at 76 stations within the Puget Lowlands eco region, which contains 12,721 km of streams and rivers (Washington Department of Ecology, 1998). Such gages are sparsely distributed, are typically located only in larger streams and rivers, and give limited information about the spatial distribution of water temperature.

  9. Upgrade of the cooling water temperature measures system for HLS

    International Nuclear Information System (INIS)

    Guo Weiqun; Liu Gongfa; Bao Xun; Jiang Siyuan; Li Weimin; He Duohui

    2007-01-01

    The cooling water temperature measures system for HLS (Hefei Light Source) adopts EPICS to the developing platform and takes the intelligence temperature cruise instrument for the front control instrument. Data of temperatures are required by IOCs through Serial Port Communication, archived and searched by Channel Archiver. The system can monitor the real-time temperatures of many channels cooling water and has the function of history data storage, and data network search. (authors)

  10. Effects of Temperature and Growing Seasons on Crop Water ...

    African Journals Online (AJOL)

    PROF HORSFALL

    The crop water requirement (CWR) depends on several factors including temperature and ...... infrastructure for collection, treatment and recycling of wastewater (MOEP, 2010 .... blue and grey water footprint of crops and derived crop products ...

  11. Cooling-water amounts, temperature, and the environment

    International Nuclear Information System (INIS)

    Koops, F.B.J.; Donze, M.; Hadderingh, R.H.

    1979-01-01

    The release of heat from power plants into a water can take place with relative small quantities of cooling water, highly warmed up accordingly, or with large quantities of cooling water slightly warmed up. The utilization of cooling water is bound to certain guidelines established by the authorities. With the intention to protect the environment, the admissable temperatures and warming-up have been strictly limited by the authorities. In the Netherlands, we have presently temporary cooling water guidelines which allow a max. temperature of the cooling water in the cooling cycle of 30 0 C and a maximum admissible temperature rise in the condenser between 7 0 C during summer and 15 0 C during winter. It has also been determined in these requirements how much cooling water at least has to be used to discharge a specified quantity of heat. Plankton, spawn and young fish are dragged with the cooling water. Harm to these organisms can be caused mechanically by pumps, sieves and the condenser or they can be harmed by the temperature rise in the condenser. Investigations showed that mechanical harm to spawn and young fish in the cooling water flow should not be ignored, and that detectable harm to plankton organisms takes place only at water temperatures above 32 0 C. The cooling water consumption can therefore be optimised as follows: The solution of a greater temperature increase and a slightly higher value for the temperature maximum can reduce the cooling water quantity. This reduction of the cooling water quantity reduces the destruction of the fish quantity, which gets into the cooling water system, especially during the summer. If the temperature rise and the temperature itself are not selected too high, the destruction of fish may be reduced without causing serious damage to the plankton. (orig.) [de

  12. Low temperature barrier wellbores formed using water flushing

    Science.gov (United States)

    McKinzie, II; John, Billy [Houston, TX; Keltner, Thomas Joseph [Spring, TX

    2009-03-10

    A method of forming an opening for a low temperature well is described. The method includes drilling an opening in a formation. Water is introduced into the opening to displace drilling fluid or indigenous gas in the formation adjacent to a portion of the opening. Water is produced from the opening. A low temperature fluid is applied to the opening.

  13. Prediction of water temperature metrics using spatial modelling in ...

    African Journals Online (AJOL)

    Water temperature regime dynamics should be viewed regionally, where regional divisions have an inherent underpinning by an understanding of natural thermal variability. The aim of this research was to link key water temperature metrics to readily-mapped environmental surrogates, and to produce spatial images of ...

  14. Thoracic outlet syndrome: Case report

    International Nuclear Information System (INIS)

    Marquez, Juan Camilo; Acosta, Mauricio Fernando; Uribe Jorge Ricardo

    2009-01-01

    We report a case of vascular thoracic outlet syndrome in a young man, diagnosed with upper limb arteriography, leading to repeated arterio-arterial emboli originating from a post-stenotic subclavian artery aneurysm. It is of our interest due to its low incidence and the small number of cases reported that have been diagnosed by arteriography. The thoracic outlet is the path through which vascular and neural structures goes from the neck to the axilla, and it has three anatomical strictures, that when pronounced, can compress the brachial plexus or subclavian vessels, leading to different symptoms and signs.

  15. Water level sensor and temperature profile detector

    International Nuclear Information System (INIS)

    Tokarz, R.D.

    1983-01-01

    A temperature profile detector comprising a surrounding length of metal tubing and an interior electrical conductor both constructed of high temperature high electrical resistance materials. A plurality of gas-filled expandable bellows made of electrically conductive material is electrically connected to the interior electrical conductor and positioned within the length of metal tubing. The bellows are sealed and contain a predetermined volume of a gas designed to effect movement of the bellows from an open circuit condition to a closed circuit condition in response to monitored temperature changes sensed by each bellows

  16. Water level sensor and temperature profile detector

    Science.gov (United States)

    Tokarz, Richard D.

    1983-01-01

    A temperature profile detector comprising a surrounding length of metal tubing and an interior electrical conductor both constructed of high temperature high electrical resistance materials. A plurality of gas-filled expandable bellows made of electrically conductive material is electrically connected to the interior electrical conductor and positioned within the length of metal tubing. The bellows are sealed and contain a predetermined volume of a gas designed to effect movement of the bellows from an open circuit condition to a closed circuit condition in response to monitored temperature changes sensed by each bellows.

  17. Temperature noise characteristics of pressurized water reactors

    International Nuclear Information System (INIS)

    Sweeney, F.J.; Upadhyaya, B.R.

    1984-01-01

    The core exit temperature noise RMS is linearly related to the core ΔT at a commercial PWR and LOFT. Test loop observations indicate that this linear behavior becomes nonlinear with blockages, boiling, or power skews. The linear neutron flux to temperature noise phase behavior is indicative of a pure time delay process, which has been shown to be related to coolant flow velocity in the core. Therefore, temperature noise could provide a valuable diagnostic tool for the detection of coolant blockages, boiling, and sensor malfunction under both normal and accident conditions in a PWR

  18. Startup of a high-temperature reactor cooled and moderated by supercritical-pressure light water

    International Nuclear Information System (INIS)

    Yi, Tin Tin; Ishiwatari, Yuki; Koshizuka, Seiichi; Oka, Yoshiaki

    2003-01-01

    The startup schemes of high-temperature reactors cooled and moderated by supercritical pressure light water (SCLWR-H) with square lattice and descending flow type water rods are studied by thermal-hydraulic analysis. In this study, two kinds of startup systems are investigated. In the constant pressure startup system, the reactor starts at a supercritical pressure. A flash tank and pressure reducing valves are necessary. The flash tank is designed so that the moisture content in the steam is less than 0.1%. In sliding pressure startup system, the reactor starts at a subcritical pressure. A steam-water separator and a drain tank are required for two-phase flow at startup. The separator is designed by referring to the water separator used in supercritical fossil-fired power plants. The maximum cladding surface temperature during the power-raising phase of startup is restricted not to exceed the rated value of 620degC. The minimum feedwater flow rate is 25% for constant pressure startup and 35% for sliding pressure startup system. It is found that both constant pressure startup system and sliding pressure startup system are feasible in SCLWR-H from the thermal hydraulic point of view. The core outlet temperature as high as 500degC can be achieved in the present design of SCLWR-H. Since the feedwater flow rate of SCLWR-H (1190 kg/s) is lower than that of the previous SCR designs the weight of the component required for startup is reduced. The sliding pressure startup system is better than constant pressure startup system in order to reduce the required component weight (and hence material expenditure) and to simplify the startup plant system. (author)

  19. Mechanism of high-temperature resistant water-base mud

    Energy Technology Data Exchange (ETDEWEB)

    Luo, P

    1981-01-01

    Based on experiments, the causes and laws governing the changes in the performance of water-base mud under high temperature are analyzed, and the requisites and mechanism of treating agents resisting high temperature are discussed. Ways and means are sought for inhibiting, delaying and making use of the effect of high temperature on the performance of mud, while new ideas and systematic views have been expressed on the preparation of treating agents and set-up of a high temperature resistant water-base mud system. High temperature dispersion and high temperature surface inactivation of clay in the mud, as well as their effect and method of utilization are reviewed. Subjects also touched upon include degradation and cross-linking of the high-temperature resistant treating agents, their use and effect. Based on the above, the preparation of a water-base and system capable of resisting 180 to 250/sup 0/C is recommended.

  20. Salinity and temperature variations around Peninsula Malaysia coastal waters

    International Nuclear Information System (INIS)

    Abdul Kadir Ishak; Jeremy Andy Anak Dominic; Nazrul Hizam Yusof; Mohd Rafaei Murtadza

    2004-01-01

    Vertical profiles of salinity and temperature were measured at several offshore stations along east and west coast of Peninsula Malaysia coastal waters. The measurements which covered South China Sea and Straits of Malacca were made during sampling cruises for Marine Database Project for Peninsula Malaysia, and during an IAEA regional training course for Marine Pollution Project. The results show that the water temperature is highest at the surface and minimum at bottom, while the salinity is lowest at the surface and highest at the bottom. In Malacca Straits, the highest surface water temperature was 30.6 degree C and the lowest bottom water temperature was 20.4 degree C, recorded at a station located in Andaman Sea. The same station also recorded the highest surface and bottom salinity i.e. 31.3 ppt and 34.4 ppt, respectively. For South China Sea, the maximum surface water temperature was 30.4 degree C and the minimum bottom temperature was 25.9 degree C, while the highest surface salinity was 33.2 ppt and the highest bottom salinity was 34.1 ppt. The water in South China Sea also showed some degrees of stratifications with thermocline zones located between 10-40 m water depths. In Malacca Straits, stronger thermocline develops at higher latitude, while at lower latitude the water is more readily mixed. Beside the spatial variations, the seawater temperature and salinity around Peninsula Malaysia also subjected to temporal variation as seawater. (Author)

  1. The Effect of Nitrogen Cross-Over on Water Balance Measurements in Proton Exchange Membrane Fuel Cell Using Constant Temperature Anemometry

    DEFF Research Database (Denmark)

    Al Shakhshir, Saher; Berning, Torsten; Kær, Søren Knudsen

    2016-01-01

    A novel method to obtain an ad-hoc and real time electrical signal of the PEMFC water balance by employing a constant temperature hot wire anemometry has been developed by our fuel cell research group. In this work, the effect of nitrogen-cross over on this method is experimentally demonstrated...... by introducing 1% of nitrogen concentration to the dry and humidified hydrogen flow simulating the PEMFC anode outlet. The hot wire voltage is measured with and without nitrogen and it was slightly lower with the presence of nitrogen. The effect of the voltage reduction on the measured water balance is small...

  2. Characterizing subsurface water flow to artificial drain lines using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Shults, D.; Brooks, E. S.; Heinse, R.; Keller, C. K.

    2017-12-01

    dampened response to snow melt and precipitation events during the winter indicating matrix flow was the predominate flow mechanism. In addition to temperature traces, water chemistry (electrical conductivity, pH and nitrate) and discharge measurements were collected at the outlet of each drain line as well as at access ports along the drain lines.

  3. Growth of Legionella anisa in a model drinking water system to evaluate different shower outlets and the impact of cast iron rust.

    Science.gov (United States)

    van der Lugt, Wilco; Euser, Sjoerd M; Bruin, Jacob P; Den Boer, Jeroen W; Walker, Jimmy T; Crespi, Sebastian

    2017-11-01

    Legionella continues to be a problem in water systems. This study investigated the influence of different shower mixer faucets, and the influence of the presence of cast iron rust from a drinking water system on the growth of Legionella. The research is conducted using a model of a household containing four drinking water systems. All four systems, which contained standard plumbing components including copper pipes and a water heater, were filled with unchlorinated drinking water. Furthermore, all systems had three different shower faucets: (A) a stainless-steel faucet, (B) a brass-ceramic faucet, and (C) a brass thermostatic faucet. System 1 was solely filled with drinking water. System 2 was filled with drinking water, and cast iron rust. System 3 was contaminated with Legionella, and system 4 was contaminated with a Legionella, and cast iron rust. During a period of 34 months, 450 cold water samples were taken from 15 sample points of the four drinking water systems, and tested for Legionella according to the Dutch Standard (NEN 6265). In system 4, with added cast iron rust, the stainless-steel mixer faucet (A) had the highest concentration of Legionella at >4.3log10CFU/l (>20,000CFU/l) and was positive in 46.4% of samples. In contrast, the stainless-steel mixer faucet (A) of system 3 without cast iron rust showed 14.3% positive samples with a maximum concentration of 3.9log10CFU/l (7600CFU/l) Legionella. Additionally, both contaminated systems (3 and 4), with the brass thermostatic faucet (C), tested positive for Legionella. System 3 in 85.7% of the samples, with a maximum concentration of 4.38log10CFU/l (24,200CFU/l), and system 4 in 64.3% of the samples with a maximum concentration of 4.13log10CFU/l (13.400CFU/l). These results suggest that both the type of faucet used in a drinking water system and the presence or absence of cast iron rust influence the growth of Legionella. Copyright © 2017 Elsevier GmbH. All rights reserved.

  4. Integrated collector storage solar water heater: Temperature stratification

    International Nuclear Information System (INIS)

    Garnier, C.; Currie, J.; Muneer, T.

    2009-01-01

    An analysis of the temperature stratification inside an Integrated Collector Storage Solar Water Heater (ICS-SWH) was carried out. The system takes the form of a rectangular-shaped box incorporating the solar collector and storage tank into a single unit and was optimised for simulation in Scottish weather conditions. A 3-month experimental study on the ICS-SWH was undertaken in order to provide empirical data for comparison with the computed results. Using a previously developed macro model; a number of improvements were made. The initial macro model was able to generate corresponding water bulk temperature in the collector with a given hourly incident solar radiation, ambient temperature and inlet water temperature and therefore able to predict ICS-SWH performance. The new model was able to compute the bulk water temperature variation in different SWH collectors for a given aspect ratio and the water temperature along the height of the collector (temperature stratification). Computed longitudinal temperature stratification results obtained were found to be in close agreement with the experimental data.

  5. Storm-induced water dynamics and thermohaline structure at the tidewater Flade Isblink Glacier outlet to theWandel Sea (NE Greenland)

    DEFF Research Database (Denmark)

    Kirillov, Sergei; Dmitrenko, Igor; Rysgaard, Soren

    2017-01-01

    In April 2015, an ice-tethered conductivity-temperature-depth (CTD) profiler and a down-looking acoustic Doppler current profiler (ADCP) were deployed from the landfast ice near the tidewater glacier terminus of the Flade Isblink Glacier in the Wandel Sea, NE Greenland. The 3-week time series...

  6. NOAA NDBC SOS, 2006-present, sea_water_temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NDBC SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have sea_water_temperature data. Because of the nature of SOS requests,...

  7. NOAA NOS SOS, EXPERIMENTAL, 1853-present, Water Temperature

    Data.gov (United States)

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

  8. NOS CO-OPS Meteorological Data, Water Temperature, 6-Minute

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has Water Temperature data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These preliminary data have not...

  9. Advances in high temperature water chemistry and future issues

    International Nuclear Information System (INIS)

    Millett, P.J.

    2005-01-01

    This paper traces the development of advances in high temperature water chemistry with emphasis in the field of nuclear power. Many of the water chemistry technologies used in plants throughout the world today would not have been possible without the underlying scientific advances made in this field. In recent years, optimization of water chemistry has been accomplished by the availability of high temperature water chemistry codes such as MULTEQ. These tools have made the science of high temperature chemistry readily accessible for engineering purposes. The paper closes with a discussion of what additional scientific data and insights must be pursued in order to support the further development of water chemistry technologies for the nuclear industry. (orig.)

  10. Hydrologic Outlets of the Greenland Ice Sheet

    Data.gov (United States)

    National Aeronautics and Space Administration — The Hydrologic Outlets of the Greenland Ice Sheet data set contains GIS point shapefiles that include 891 observed and potential hydrologic outlets of the Greenland...

  11. Contamination of faecal coliforms in ice cubes sampled from food outlets in Kubang Kerian, Kelantan.

    Science.gov (United States)

    Noor Izani, N J; Zulaikha, A R; Mohamad Noor, M R; Amri, M A; Mahat, N A

    2012-03-01

    The use of ice cubes in beverages is common among patrons of food outlets in Malaysia although its safety for human consumption remains unclear. Hence, this study was designed to determine the presence of faecal coliforms and several useful water physicochemical parameters viz. free residual chlorine concentration, turbidity and pH in ice cubes from 30 randomly selected food outlets in Kubang Kerian, Kelantan. Faecal coliforms were found in ice cubes in 16 (53%) food outlets ranging between 1 CFU/100mL to >50 CFU/ 100mL, while in the remaining 14 (47%) food outlets, in samples of tap water as well as in commercially bottled drinking water, faecal coliforms were not detected. The highest faecal coliform counts of >50 CFU/100mL were observed in 3 (10%) food outlets followed by 11-50 CFU/100mL and 1-10 CFU/100mL in 7 (23%) and 6 (20%) food outlets, respectively. All samples recorded low free residual chlorine concentration (contamination by faecal coliforms was not detected in 47% of the samples, tap water and commercially bottled drinking water, it was concluded that (1) contamination by faecal coliforms may occur due to improper handling of ice cubes at the food outlets or (2) they may not be the water sources used for making ice cubes. Since low free residual chlorine concentrations were observed (food outlets, including that of ice cube is crucial in ensuring better food and water for human consumption.

  12. Cooling Characteristics of the V-1650-7 Engine. II - Effect of Coolant Conditions on Cylinder Temperatures and Heat Rejection at Several Engine Powers

    Science.gov (United States)

    Povolny, John H.; Bogdan, Louis J.; Chelko, Louis J.

    1947-01-01

    An investigation has been conducted on a V-1650-7 engine to determine the cylinder temperatures and the coolant and oil heat rejections over a range of coolant flows (50 to 200 gal/min) and oil inlet temperatures (160 to 2150 F) for two values of coolant outlet temperature (250 deg and 275 F) at each of four power conditions ranging from approximately 1100 to 2000 brake horsepower. Data were obtained for several values of block-outlet pressure at each of the two coolant outlet temperatures. A mixture of 30 percent by volume of ethylene glycol and 70-percent water was used as the coolant. The effect of varying coolant flow, coolant outlet temperature, and coolant outlet pressure over the ranges investigated on cylinder-head temperatures was small (0 deg to 25 F) whereas the effect of increasing the engine power condition from ll00 to 2000 brake horsepower was large (maximum head-temperature increase, 110 F).

  13. Temperature stratification in a hot water tank with circulation pipe

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1998-01-01

    The aim of the project is to investigate the change in temperature stratification due to the operation of a circulation pipe. Further, putting forward rules for design of pipe inlet in order not to disturb the temperature stratification in the hot water tank. A validated computer model based on t...

  14. Possible effects of regulating hydroponic water temperature on plant ...

    African Journals Online (AJOL)

    Water temperature can affect many physiological processes during plant growth and development. Temperatures below or above optimum levels may influence plant metabolic activities positively or negatively. This may include accumulation of different metabolites such as phenolic compounds, reactive oxygen species ...

  15. Thermal and water management of low temperature Proton Exchange Membrane Fuel Cell in fork-lift truck power system

    International Nuclear Information System (INIS)

    Hosseinzadeh, Elham; Rokni, Masoud; Rabbani, Abid; Mortensen, Henrik Hilleke

    2013-01-01

    Highlights: ► Developing a general zero dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model for a forklift. ► System performance with different cooling fluids. ► Water and thermal management of fuel cell system. ► Effect of inlet temperature, outlet temperature and temperature gradient on system performance. - Abstract: A general zero-dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model has been developed for forklift truck application. The balance of plant (BOP) comprises of a compressor, an air humidifier, a set of heat exchangers and a recirculation pump. Water and thermal management of the fuel cell stack and BOP has been investigated in this study. The results show that humidification of the inlet air is of great importance. By decreasing the relative humidity of inlet air from 95% to 25%, the voltage can drop by 29%. In addition, elevated stack temperature can lead to a higher average cell voltage when membrane is fully hydrated otherwise it causes a drastic voltage drop in the stack. Furthermore, by substituting liquid water with water–ethylene glycol mixture of 50%, the mass flow of coolant increases by about 32–33% in the inner loop and 60–65% in the outer loop for all ranges of current. The system can then be started up at about −25 °C with negligible change in the efficiency

  16. An observational study on the temperature rising effects in water warming canal and water warming pond

    Energy Technology Data Exchange (ETDEWEB)

    Hong, J. B.; Hong, S. B. [Rural Development Cooperation, Seoul (Korea, Republic of)

    1990-09-15

    The power water flowed out from the multipurpose darn influences the ecosystem approximately because of the low water temperature. An appropriate counter measure to the rising water temperature is needed for growing crops especially when the temperature is below 18°C in the source of the irrigation water This observational study is practiced in Yong-Doo water warming canal and pond in the down stream of Choong-Ju multipurpose dam and is practiced for analyse and compare the rising effects in actural water temperature by actual measurement with the rising effects of planned water temperatuer by the basic theoritical method and for the help to present the direction in plan establishment through investigate the results afterwards. The results are as follows. 1. The degree of the rise of the water temperature can be decided by θ{sub x} = θ{sub 0} + K (L/(v * h)) * (T - θ{sub 0}) Then, K values of a factor representing the characteristics of the water warming canal were 0.00002043 for the type I. and 0.0000173 for the type II. respectively. 2. A variation of water temperature which produced by the difference effective temperature and water temperature in the water warming canal was θ{sub x1} = 16.5 + 15.9 (1-e{sup -0.00018x}), θ{sub x2} = 18.8 + 8.4(1-e{sup -0.000298x}) for the type I. and θ{sub x} = 19.6 + 12.8 (1-e{sup -0.00041x}) for the type II. 3. It was shown that the effects of the rise of water temperature for the type I. water warming canal were greater than that of type II. as a resultes of broadening the surface of the canal compared with the depth of water, coloring the surface of water canal and installing the resistance block. 4. In case of the type I. water warming canal, the equation between the air temperature and the degree of the rise of water temprature could be made; Y = 0.4134X + 7.728 In addition, in case of the type II. water warming canal, the correlation was very low. 5. A monthly variation of the water temperature in the water warming

  17. Global River Discharge and Water Temperature under Climate Change

    NARCIS (Netherlands)

    Vliet, van M.T.H.; Franssen, W.H.P.; Yearsley, J.R.; Ludwig, F.; Haddeland, I.; Lettenmaier, D.P.; Kabat, P.

    2013-01-01

    Climate change will affect hydrologic and thermal regimes of rivers, having a direct impact on freshwater ecosystems and human water use. Here we assess the impact of climate change on global river flows and river water temperatures, and identify regions that might become more critical for

  18. Influence of fine water droplets to temperature and humidity

    Science.gov (United States)

    Hafidzal, M. H. M.; Hamzah, A.; Manaf, M. Z. A.; Saadun, M. N. A.; Zakaria, M. S.; Roslizar, A.; Jumaidin, R.

    2015-05-01

    Excessively dry air can cause dry skin, dry eyes and exacerbation of medical conditions. Therefore, many researches have been done in order to increase humidity in our environment. One of the ways is by using water droplets. Nowadays, it is well known in market stand fan equipped with water mister in order to increase the humidity of certain area. In this study, the same concept is applied to the ceiling fan. This study uses a model that combines a humidifier which functions as cooler, ceiling fan and scaled down model of house. The objective of this study is to analyze the influence of ceiling fan humidifier to the temperature and humidity in a house. The mechanism of this small model uses batteries as the power source, connected to the fan and the humidifier. The small water tank's function is to store and supply water to the humidifier. The humidifier is used to cool the room by changing water phase to fine water droplets. Fine water droplets are created from mechanism of the humidifier, which is by increasing the kinetic energy of water molecule using high frequency vibration that overcome the holding force between water molecules. Thus, the molecule of water will change to state of gas or mist. The fan is used to spread out the mist of water to surrounding of the room in order to enhance the humidity. Thermocouple and humidity meter are used to measure temperature and humidity in some period of times. The result shows that humidity increases and temperature decreases with time. This application of water droplet can be applied in the vehicles and engine in order to decrease the temperature.

  19. Flue gas moisture capacity calculation at the outlet of the condensation heat recovery unit

    Directory of Open Access Journals (Sweden)

    Galashov Nikolay

    2017-01-01

    Full Text Available As a result, study equation has been obtained which determine the flue gas moisture capacity at the outlet of the condensation heat recovery unit with an error of less than 1%. It possible to at the temperature of the flue gas below the dew point and the known air-fuel ratio efficient. The equation can be used to calculate plants operating on products of gas combustion without Use of tables and programs for calculating the water-vapor saturation pressure.

  20. Historical Change of Equilibrium Water Temperature in Japan

    Science.gov (United States)

    Miyamoto, H.

    2015-12-01

    Changes in freshwater ecosystems due to a climate change have been great concern for sustainable river basin management both for water resources utilization and ecological conservation. However, their impact seems to be difficult to evaluate because of wide variety of basin characteristics along a river network both in nature and social environment. This presentation uses equilibrium water temperature as a simple criterion index for evaluating the long-term changes of stream thermal environment due to the historical climate change in Japan. It examines, at first, the relationship between the equilibrium water temperature and the stream temperature observed for 7 years at a lower reach in the Ibo River, Japan. It analyzes, then, the seasonal and regional trends of the equilibrium water temperature change for the last 50 years at 133 meteorological station sites throughout Japan, discussing their rising or falling characteristics. The correlation analysis at the local reach of the Ibo River shows that the equilibrium water temperature has similar trend of change as the stream temperature. However, its value tends to be higher than the stream temperature in summer, while lower in winter. The onset of the higher equilibrium water temperature fluctuates annually from mid February to early April. This onset fluctuation at each spring could be influenced by the different amount of snow at the antecedent winter. The rising or falling trends of the equilibrium water temperature are analyzed both annually and seasonally through the regression analysis of the 133 sites in Japan. Consequently, the trends of the temperature change could be categorized by 12 patterns. As for the seasonal analysis, the results shows that there are many sites indicating the falling trend in spring and summer, and rising trends in autumn and winter. In particular, winter has the strong rising tendency throughout Japan. As for the regional analysis, the result illustrates the precise rationality; e

  1. Water Recycling removal using temperature-sensitive hydronen

    Energy Technology Data Exchange (ETDEWEB)

    Rana B. Gupta

    2002-10-30

    The overall objective of this project was to study the proposed Water Recycling/Removal Using Temperature-Sensitive Hydrogels. The main element of this technology is the design of a suitable hydrogel that can perform needed water separation for pulp and paper industry. The specific topics studied are to answer following questions: (a) Can water be removed using hydrogel from large molecules such as lignin? (b) Can the rate of separation be made faster? (c) What are the molecular interactions with hydrogel surface? (d) Can a hydrogel be designed for a high ionic strength and high temperature? Summary of the specific results are given.

  2. Measurements of hot water service consumptions: temperature influence

    Energy Technology Data Exchange (ETDEWEB)

    Secchi, R.; Vallat, D.; Cyssau, R. (COSTIC, Saint Remy-les-Chevreuse (France))

    This article presents a campaign of measurements of which the aim is the observation of consumptions, for individual installations equiped with a hot water tank. The study takes an interest in the temperature of the water in the tank and the instantaneous power of the generator. The instrumentation, the installations and the results of this campaign are presented in this paper. The conclusion is the ''economic'' temperature of hot sanitary water is below 60/sup 0/C but above 55/sup 0/C.

  3. Whole body cooling by immersion in water at moderate temperatures.

    Science.gov (United States)

    Marino, F; Booth, J

    1998-06-01

    This study investigated the potential use of whole body cooling by water immersion for lowering body temperatures prior to endurance exercise. Rectal temperature (Tre), mean skin temperature (Tsk), oxygen consumption (VO2), and ventilation (VE) were measured in 7 male and 3 female subjects who were immersed in a water bath for up to 60 min. Initial water temperature was 28.8+/-1.5 degrees C and decreased to 23.8+/-1.1 degrees C by the end of immersion. Pre-immersion Tre of 37.34+/-0.36 degrees C was not altered by 60 min water immersion but decreased to 36.64+/-0.34 degrees C at 3 min post immersion (p immersion. Reductions in Tre and Tsk resulted in reduced body heat content (Hc) of approximately 545 kJ (p immersion. VO2 and VE increased from pre-immersion values of 0.34+/-0.08 L x min(-1) and 6.2+/-1.4 L x min(-1) to 0.54+/-0.09 L x min(-) and 11.5+/-5.4 L x min(-1) at the end of immersion, respectively. Heart rate remained unchanged throughout immersion. These results indicate that whole body immersion in moderately cold water temperatures is an effective cooling maneuver for lowering body temperatures and body Hc in the absence of severe physiological responses generally associated with sudden cold stress.

  4. Soil Water and Temperature System (SWATS) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, David R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-04-01

    The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models to determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.

  5. Analysis on blow-down transient in water ingress accident of high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Wang, Yan; Zheng, Yanhua; Li, Fu; Shi, Lei

    2014-01-01

    Water ingress into the primary circuit is generally recognized as one of the severe accidents with potential hazard to the modular high temperature gas-cooled reactor, which will cause a positive reactivity introduction with the increase of steam density in reactor core to enhance neutron slowing-down, also the chemical corrosion of graphite fuel elements and the damage of reflector structure material. The increase of the primary pressure may result in the opening of the safety valves, consequently leading the release of radioactive isotopes and flammable water gas. The research on water ingress transient is significant for the verification of inherent safety characteristics of high temperature gas-cooled reactor. The 200 MWe high temperature gas-cooled reactor (HTR-PM), designed by the Institute of Nuclear and New Energy Technology of Tsinghua University, is exampled to be analyzed in this paper. The design basis accident (DBA) scenarios of double-ended guillotine break of single heat-exchange tube (steam generator heat-exchange tube rupture) are simulated by the thermal-hydraulic analysis code, and some key concerns which are relative to the amount of water into the reactor core during the blow-down transient are analyzed in detail. The results show that both of water mass and steam ratio of the fluid spouting from the broken heat-exchange tube are affected by break location, which will increase obviously with the broken location closing to the outlet of the heat-exchange tube. The double-ended guillotine rupture at the outlet of the heat-exchange will result more steam penetrates into the reactor core in the design basis accident of water ingress. The mass of water ingress will also be affected by the draining system. It is concluded that, with reasonable optimization on design to balance safety and economy, the total mass of water ingress into the primary circuit of reactor could be limited effectively to meet the safety requirements, and the pollution of

  6. Temperature impacts on the water year 2014 drought in California

    Science.gov (United States)

    Shukla, Shraddhanand; Safeeq, Mohammad; AghaKouchak, Amir; Guan, Kaiyu; Funk, Christopher C.

    2015-01-01

    California is experiencing one of the worst droughts on record. Here we use a hydrological model and risk assessment framework to understand the influence of temperature on the water year (WY) 2014 drought in California and examine the probability that this drought would have been less severe if temperatures resembled the historical climatology. Our results indicate that temperature played an important role in exacerbating the WY 2014 drought severity. We found that if WY 2014 temperatures resembled the 1916–2012 climatology, there would have been at least an 86% chance that winter snow water equivalent and spring-summer soil moisture and runoff deficits would have been less severe than the observed conditions. We also report that the temperature forecast skill in California for the important seasons of winter and spring is negligible, beyond a lead-time of one month, which we postulate might hinder skillful drought prediction in California.

  7. Optimum hot water temperature for absorption solar cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  8. IMPACT OF WATER TEMPERATURE ON ZEBRA MUSSEL MORTALITY

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2002-08-07

    These tests conducted this past quarter have indicated that the bacterium Pseudomonas fluorescens strain CL0145A is effective at killing zebra mussels at water temperatures ranging from 7 to 23 C. Percent kill will likely be somewhat lower at very low temperatures, e.g., 7 C, but even at such low temperatures high mussel kill can still be achieved (>70% kill). This is significant because the development of a zebra mussel control method that is efficacious in such a wide range of temperatures broadens its usefulness as a potential commercial product.

  9. Cellular changes in the skin of the rainbow trout (Oncorhynchus Mykiss) after short-term exposure to increased water temperature: Part 2: Experiments with Rhine water

    International Nuclear Information System (INIS)

    Iger, I.; Jenner, H.A.

    1994-01-01

    The aim of the study on the title subject is to show that salmonides in a simulated cooling water outlet area of an electric power plant along the river Rhine do not experience long-term or permanent negative consequences of their presence in the heated water. Laboratory experiments were carried out with 'test trouts'. The water in which the trouts were kept was heated up from 9C to 16C in 30 minutes. The temperature of 16C was maintained for 3 hours. After the heating up skin samples were taken at different periods for 35 days. Histochemical and electron microscopic investigations were carried out. The short term increase of the water temperature clearly effected the ultrastructure of the fish. The changes in the epidermis did not recover within 35 days. It is suggested that a number of the found cellular reactions can be used as indicators for environmental stress. These reactions concern the production of lysosomes and the migration of macrophages in the epidermis. No serious effects as skin decomposition and an excess of mucous secretion were found

  10. Increasing Water Temperature Triggers Dominance of Small Freshwater Plankton.

    Science.gov (United States)

    Rasconi, Serena; Gall, Andrea; Winter, Katharina; Kainz, Martin J

    2015-01-01

    Climate change scenarios predict that lake water temperatures will increase up to 4°C and rainfall events will become more intense and frequent by the end of this century. Concurrently, supply of humic substances from terrestrial runoff is expected to increase, resulting in darker watercolor ("brownification") of aquatic ecosystems. Using a multi-seasonal, low trophic state mesocosm experiment, we investigated how higher water temperature and brownification affect plankton community composition, phenology, and functioning. We tested the hypothesis that higher water temperature (+3°C) and brownification will, a) cause plankton community composition to shift toward small sized phytoplankton and cyanobacteria, and, b) extend the length of the growing season entailing higher phytoplankton production later in the season. We demonstrate that the 3°C increase of water temperature favored the growth of heterotrophic bacteria and small sized autotrophic picophytoplankton cells with significantly higher primary production during warmer fall periods. However, 3X darker water (effect of brownification) caused no significant changes in the plankton community composition or functioning relative to control conditions. Our findings reveal that increased temperature change plankton community structure by favoring smaller sized species proliferation (autotrophic phytoplankton and small size cladocerans), and increase primary productivity and community turnover. Finally, results of this multi-seasonal experiment suggest that warming by 3°C in aquatic ecosystems of low trophic state may cause planktonic food web functioning to become more dominated by fast growing, r-trait species (i.e., small sizes and rapid development).

  11. Water Plume Temperature Measurements by an Unmanned Aerial System (UAS

    Directory of Open Access Journals (Sweden)

    Anthony DeMario

    2017-02-01

    Full Text Available We report on the development and testing of a proof of principle water temperature measurement system deployed on an unmanned aerial system (UAS, for field measurements of thermal discharges into water. The primary elements of the system include a quad-copter UAS to which has been integrated, for the first time, both a thermal imaging infrared (IR camera and an immersible probe that can be dipped below the water surface to obtain vertical water temperature profiles. The IR camera is used to take images of the overall water surface to geo-locate the plume, while the immersible probe provides quantitative temperature depth profiles at specific locations. The full system has been tested including the navigation of the UAS, its ability to safely carry the sensor payload, and the performance of both the IR camera and the temperature probe. Finally, the UAS sensor system was successfully deployed in a pilot field study at a coal burning power plant, and obtained images and temperature profiles of the thermal effluent.

  12. Water Plume Temperature Measurements by an Unmanned Aerial System (UAS).

    Science.gov (United States)

    DeMario, Anthony; Lopez, Pete; Plewka, Eli; Wix, Ryan; Xia, Hai; Zamora, Emily; Gessler, Dan; Yalin, Azer P

    2017-02-07

    We report on the development and testing of a proof of principle water temperature measurement system deployed on an unmanned aerial system (UAS), for field measurements of thermal discharges into water. The primary elements of the system include a quad-copter UAS to which has been integrated, for the first time, both a thermal imaging infrared (IR) camera and an immersible probe that can be dipped below the water surface to obtain vertical water temperature profiles. The IR camera is used to take images of the overall water surface to geo-locate the plume, while the immersible probe provides quantitative temperature depth profiles at specific locations. The full system has been tested including the navigation of the UAS, its ability to safely carry the sensor payload, and the performance of both the IR camera and the temperature probe. Finally, the UAS sensor system was successfully deployed in a pilot field study at a coal burning power plant, and obtained images and temperature profiles of the thermal effluent.

  13. Dynamic behaviour of bubbles of water vapour at a temperature lower than the boiling temperature

    International Nuclear Information System (INIS)

    Jansen, Franz

    1966-01-01

    This research thesis reports the study of the theoretical movement of the wall of vapour water bubbles in a sub-saturated boiling regime, i.e. with an average water temperature lower than the boiling temperature. While assuming that bubbles have an initial translational speed at the beginning of their condensation, the author shows that their shrinkage should result in an accelerated displacement in a direction normal to the wall and inward the liquid. Layers of hot water initially close to the wall would therefore be quickly transported towards cold water areas. Experiments allowed, in some cases, the acceleration of bubbles during their condensation to be noticed: for low sub-saturations in still water and for high sub-saturations in water in forced convection, even though, in this last case, the determination of accelerations is more delicate [fr

  14. Outlet Glacier-Ice Shelf-Ocean Interactions: Is the Tail Wagging the Dog?

    Science.gov (United States)

    Parizek, B. R.; Walker, R. T.; Rinehart, S. K.

    2009-12-01

    While the massive interior regions of the Antarctic and Greenland Ice Sheets are presently ``resting quietly", the lower elevations of many outlet glaciers are experiencing dramatic adjustments due to changes in ice dynamics and/or surface mass balance. Oceanic and/or atmospheric forcing in these marginal regions often leads to mass deficits for entire outlet basins. Therefore, coupling the wagging tail of ice-ocean interactions with the vast ice-sheet reservoirs is imperative for accurate assessments of future sea-level rise. To study ice-ocean dynamic processes, we couple an ocean-plume model that simulates ice-shelf basal melting rates based on temperature and salinity profiles combined with plume dynamics associated with the geometry of the ice-shelf cavity (following Jenkins, 1991 and Holland and Jenkins, 1999) with a two-dimensional, isothermal model of outlet glacier-ice shelf flow (as used in Alley et al., 2007; Walker et al., 2008; Parizek et al., in review). Depending on the assigned temperature and salinity profiles, the ocean model can simulate both water-mass end-members: either cold High Salinity Shelf Water (HSSW) or relatively warm Circumpolar Deep Water (CDW), as well as between-member conditions. Notably, the coupled system exhibits sensitivity to the initial conditions. In particular, melting concentrated near the grounding line has the greatest effect in forcing grounding-line retreat. Retreat is further enhanced by a positive feedback between the ocean and ice, as the focused melt near the grounding line leads to an increase in the local slope of the basal ice, thereby enhancing buoyancy-driven plume flow and subsequent melt rates.

  15. Reconstructing bottom water temperatures from measurements of temperature and thermal diffusivity in marine sediments

    Science.gov (United States)

    Miesner, F.; Lechleiter, A.; Müller, C.

    2015-07-01

    Continuous monitoring of oceanic bottom water temperatures is a complicated task, even in relatively easy-to-access basins like the North or Baltic seas. Here, a method to determine annual bottom water temperature variations from inverse modeling of instantaneous measurements of temperatures and sediment thermal properties is presented. This concept is similar to climate reconstructions over several thousand years from deep borehole data. However, in contrast, the presented method aims at reconstructing the recent temperature history of the last year from sediment thermal properties and temperatures from only a few meters depth. For solving the heat equation, a commonly used forward model is introduced and analyzed: knowing the bottom water temperature variations for the preceding years and the thermal properties of the sediments, the forward model determines the sediment temperature field. The bottom water temperature variation is modeled as an annual cosine defined by the mean temperature, the amplitude and a phase shift. As the forward model operator is non-linear but low-dimensional, common inversion schemes such as the Newton algorithm can be utilized. The algorithms are tested for artificial data with different noise levels and for two measured data sets: from the North Sea and from the Davis Strait. Both algorithms used show stable and satisfying results with reconstruction errors in the same magnitude as the initial data error. In particular, the artificial data sets are reproduced with accuracy within the bounds of the artificial noise level. Furthermore, the results for the measured North Sea data show small variances and resemble the bottom water temperature variations recorded from a nearby monitoring site with relative errors smaller than 1 % in all parameters.

  16. Sea water desalination utilizing waste heat by low temperature evaporation

    International Nuclear Information System (INIS)

    Raha, A.; Srivastava, A.; Rao, I.S.; Majumdar, M.; Srivastava, V.K.; Tewari, P.K.

    2007-01-01

    Economics of a process is controlled by management of energy and resources. Fresh water has become most valued resource in industries. Desalination is a process by which fresh water resource is generated from sea water or brackish water, but it is an energy intensive process. The energy cost contributes around 25-40% to the total cost of the desalted water. Utilization of waste heat from industrial streams is one of the ecofriendly ways to produce low cost desalted water. Keeping this in mind Low Temperature Evaporation (LTE) desalination technology utilizing low quality waste heat in the form of hot water (as low as 50 deg C) or low pressure steam (0.13 bar) has been developed for offshore and land based applications to produce high purity water (conductivity < 2μS/cm) from sea water. The probability of the scale formation is practically eliminated by operating it at low temperature and controlling the brine concentration. It also does not require elaborate chemical pretreatment of sea water except chlorination, so it has no environmental impact. LTE technology has found major applications in nuclear reactors where large quantity of low quality waste heat is available to produce high quality desalted water for make up water requirement replacing conventional ion exchange process. Successful continuous operation of 30 Te/day LTE desalination plant utilizing waste heat from nuclear research reactor has demonstrated the safety, reliability, extreme plant availability and economics of nuclear desalination by LTE technology. It is also proposed to utilize waste heat from Main Heat Transport (MHT) purification circuit of Advanced Heavy Water Reactor (AHWR) to produce about 250 Te/ day high quality desalinated water by Low Temperature Evaporation (LTE) process for the reactor make up and plant utilization. Recently we have commissioned a 50 Te/day 2-effect low temperature desalination plant with cooling tower where the specific energy and cooling water requirement are

  17. Genetic Programming and Standardization in Water Temperature Modelling

    Directory of Open Access Journals (Sweden)

    Maritza Arganis

    2009-01-01

    Full Text Available An application of Genetic Programming (an evolutionary computational tool without and with standardization data is presented with the aim of modeling the behavior of the water temperature in a river in terms of meteorological variables that are easily measured, to explore their explanatory power and to emphasize the utility of the standardization of variables in order to reduce the effect of those with large variance. Recorded data corresponding to the water temperature behavior at the Ebro River, Spain, are used as analysis case, showing a performance improvement on the developed model when data are standardized. This improvement is reflected in a reduction of the mean square error. Finally, the models obtained in this document were applied to estimate the water temperature in 2004, in order to provide evidence about their applicability to forecasting purposes.

  18. A Water Temperature Simulation Model for Rice Paddies With Variable Water Depths

    Science.gov (United States)

    Maruyama, Atsushi; Nemoto, Manabu; Hamasaki, Takahiro; Ishida, Sachinobu; Kuwagata, Tsuneo

    2017-12-01

    A water temperature simulation model was developed to estimate the effects of water management on the thermal environment in rice paddies. The model was based on two energy balance equations: for the ground and for the vegetation, and considered the water layer and changes in the aerodynamic properties of its surface with water depth. The model was examined with field experiments for water depths of 0 mm (drained conditions) and 100 mm (flooded condition) at two locations. Daily mean water temperatures in the flooded condition were mostly higher than in the drained condition in both locations, and the maximum difference reached 2.6°C. This difference was mainly caused by the difference in surface roughness of the ground. Heat exchange by free convection played an important role in determining water temperature. From the model simulation, the temperature difference between drained and flooded conditions was more apparent under low air temperature and small leaf area index conditions; the maximum difference reached 3°C. Most of this difference occurred when the range of water depth was lower than 50 mm. The season-long variation in modeled water temperature showed good agreement with an observation data set from rice paddies with various rice-growing seasons, for a diverse range of water depths (root mean square error of 0.8-1.0°C). The proposed model can estimate water temperature for a given water depth, irrigation, and drainage conditions, which will improve our understanding of the effect of water management on plant growth and greenhouse gas emissions through the thermal environment of rice paddies.

  19. Water temperature in irrigation return flow from the Upper Snake Rock watershed

    Science.gov (United States)

    Water returning to a river from an irrigated watershed could increase the water temperature in the river. The objective of this study was to compare the temperature of irrigation return flow water with the temperature of the diverted irrigation water. Water temperature was measured weekly in the mai...

  20. Flow visualization study of two phase flow in a single bend outlet feeder pipe and horizontal annulus of outlet end-fitting of a CANDU reactor

    International Nuclear Information System (INIS)

    Supa-Amornkul, S.; Lister, D.H.; Steward, F.R.

    2005-01-01

    'Full text:' In CANDU-6 reactors, the pressurized high-temperature coolant flows through 380 fuel channels passing horizontally through the core. Each end of a fuel channel has a stainless steel annular end-fitting connected to a carbon steel feeder pipe. The outlet coolant, which is at 310 o C with up to 0.30 steam voidage, turns through 90 o as it passes from flow in the annular end-fitting to pipe flow in the feeder via a Grayloc connector. Since 1996, several CANDU stations have reported excessive corrosion of their outlet feeder pipes; especially between the first metre, which consisted of single or double bends. Early studies related the attack to the hydrodynamics of the coolant and verified that it was a type of flow accelerated corrosion. In order to understand the hydrodynamics of the coolant in the outlet feeders by flow-visualization, a full-scale transparent test section simulating the geometry and orientation of an outlet feeder bend with its upstream annular end-fitting were fabricated. The feeder consisted of a 54 mm inside diameter acrylic pipe with a 73 o bend, connecting to an acrylic simulation of a Grayloc flanged fitting and annular end-fitting. The annular end-fitting consisted of an inner pipe, 110 mm outer diameter, and an outer pipe, 150 mm inner diameter, both 190.7 cm long in length. The tests were performed with water and air at atmospheric pressure and room temperature. The maximum water volumetric flow rate was 19 L/s and the volume fraction of air varied from 0.05 to 0.56. The phase distributions within the feeder pipe and along the length of the annulus were investigated with a digital video recorder. Size, concentration and velocity of the air bubbles at particular locations were studied with a high-speed digital still camera and a high-speed digital video camera. Phase distributions and variations in bubble size with velocity were determined. Particular attention was paid to the flow pattern at the inside of the bend, where a CFD

  1. Flow visualization study of two phase flow in a single bend outlet feeder pipe and horizontal annulus of outlet end-fitting of a CANDU reactor

    Energy Technology Data Exchange (ETDEWEB)

    Supa-Amornkul, S.; Lister, D.H.; Steward, F.R. [Univ. of New Brunswick, Fredericton, New Brunswick (Canada)]. E-mail: h796e@unb.ca; dlister@unb.ca; fsteward@unb.ca

    2005-07-01

    'Full text:' In CANDU-6 reactors, the pressurized high-temperature coolant flows through 380 fuel channels passing horizontally through the core. Each end of a fuel channel has a stainless steel annular end-fitting connected to a carbon steel feeder pipe. The outlet coolant, which is at 310{sup o}C with up to 0.30 steam voidage, turns through 90{sup o} as it passes from flow in the annular end-fitting to pipe flow in the feeder via a Grayloc connector. Since 1996, several CANDU stations have reported excessive corrosion of their outlet feeder pipes; especially between the first metre, which consisted of single or double bends. Early studies related the attack to the hydrodynamics of the coolant and verified that it was a type of flow accelerated corrosion. In order to understand the hydrodynamics of the coolant in the outlet feeders by flow-visualization, a full-scale transparent test section simulating the geometry and orientation of an outlet feeder bend with its upstream annular end-fitting were fabricated. The feeder consisted of a 54 mm inside diameter acrylic pipe with a 73{sup o} bend, connecting to an acrylic simulation of a Grayloc flanged fitting and annular end-fitting. The annular end-fitting consisted of an inner pipe, 110 mm outer diameter, and an outer pipe, 150 mm inner diameter, both 190.7 cm long in length. The tests were performed with water and air at atmospheric pressure and room temperature. The maximum water volumetric flow rate was 19 L/s and the volume fraction of air varied from 0.05 to 0.56. The phase distributions within the feeder pipe and along the length of the annulus were investigated with a digital video recorder. Size, concentration and velocity of the air bubbles at particular locations were studied with a high-speed digital still camera and a high-speed digital video camera. Phase distributions and variations in bubble size with velocity were determined. Particular attention was paid to the flow pattern at the inside

  2. Nanostructural studies on monoelaidin-water systems at low temperatures.

    Science.gov (United States)

    Kulkarni, Chandrashekhar V

    2011-10-04

    In recent years, lipid based nanostructures have increasingly been used as model membranes to study various complex biological processes. For better understanding of such phenomena, it is essential to gain as much information as possible for model lipid structures under physiological conditions. In this paper, we focus on one of such lipids--monoelaidin (ME)--for its polymorphic nanostructures under varying conditions of temperature and water content. In the recent contribution (Soft Matter, 2010, 6, 3191), we have reported the phase diagram of ME above 30 °C and compared with the phase behavior of other lipids including monoolein (MO), monovaccenin (MV), and monolinolein (ML). Remarkable phase behavior of ME, stabilizing three bicontinuous cubic phases, motivates its study at low temperatures. Current studies concentrate on the low-temperature (ME and subsequent reconstruction of its phase diagram over the entire temperature-water composition space (temperature, 0-76 °C; and water content, 0-70%). The polymorphs found for the monoelaidin-water system include three bicontinuous cubic phases, i.e., Ia3d, Pn3m, and Im3m, and lamellar phases which exhibit two crystalline (L(c1) and L(c0)), two gel (L(β) and L(β*)), and a fluid lamellar (L(α)) states. The fluid isotropic phase (L(2)) was observed only for lower hydrations (<20%), whereas hexagonal phase (H(2)) was not found under studied conditions. Nanostructural parameters of these phases as a function of temperature and water content are presented together with some molecular level calculations. This study might be crucial for perception of the lyotropic phase behavior as well as for designing nanostructural assemblies for potential applications. © 2011 American Chemical Society

  3. Microwave measurements of water vapor partial pressure at high temperatures

    International Nuclear Information System (INIS)

    Latorre, V.R.

    1991-01-01

    One of the desired parameters in the Yucca Mountain Project is the capillary pressure of the rock comprising the repository. This parameter is related to the partial pressure of water vapor in the air when in equilibrium with the rock mass. Although there are a number of devices that will measure the relative humidity (directly related to the water vapor partial pressure), they generally will fail at temperatures on the order of 150C. Since thee author has observed borehole temperatures considerably in excess of this value in G-Tunnel at the Nevada Test Site (NTS), a different scheme is required to obtain the desired partial pressure data at higher temperatures. This chapter presents a microwave technique that has been developed to measure water vapor partial pressure in boreholes at temperatures up to 250C. The heart of the system is a microwave coaxial resonator whose resonant frequency is inversely proportional to the square root of the real part of the complex dielectric constant of the medium (air) filling the resonator. The real part of the dielectric constant of air is approximately equal to the square of the refractive index which, in turn, is proportional to the partial pressure of the water vapor in the air. Thus, a microwave resonant cavity can be used to measure changes in the relative humidity or partial pressure of water vapor in the air. Since this type of device is constructed of metal, it is able to withstand very high temperatures. The actual limitation is the temperature limit of the dielectric material in the cable connecting the resonator to its driving and monitoring equipment-an automatic network analyzer in our case. In the following sections, the theory of operation, design, construction, calibration and installation of the microwave diagnostics system is presented. The results and conclusions are also presented, along with suggestions for future work

  4. Does water temperature influence the performance of key survival skills?

    Science.gov (United States)

    Schnitzler, C; Button, C; Seifert, L; Armbrust, G; Croft, J L

    2018-03-01

    Aquatic survival skills may be compromised in cold water thereby increasing the likelihood of drowning. This study compared physiological, psychological, and behavioral responses of humans treading water and swimming in cold and temperate water. Thirty-eight participants were classified as inexperienced (n = 9), recreational (n = 15), or skilled (n = 10) swimmers. They performed 3 tasks: treading water (120 seconds), swim at "comfortable" pace, and swim at "fast" pace in 2 water conditions (28°C vs 10°C). Heart rate, oxygen uptake, psychometric variables, spatio-temporal (swim speed, stroke rate, and stroke length), and coordination type were examined as a function of expertise. Tasks performed in cold water-generated higher cardiorespiratory responses (HR = 145 ± 16 vs 127 ± 21 bpm) and were perceived about 2 points more strenuous on the Borg scale on average (RPE = 14.9 ± 2.8 vs 13.0 ± 2.0). The voluntary durations of both treading water (60 ± 32 vs 91 ± 33 seconds) and swimming at a comfortable pace (66 ± 22 vs 103 ± 34 seconds) were significantly reduced in cold water. However, no systematic changes in movement pattern type could be determined in either the treading water task or the swimming tasks. Water temperature influences the physical demands of these aquatic skills but not necessarily the behavior. Training treading water and swimming skills in temperate water seems to transfer to cold water, but we recommend training these skills in a range of water conditions to help adapt to the initial "cold-shock" response. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Water-temperature data acquisition activities in the United States

    Science.gov (United States)

    Pauszek, F.H.

    1972-01-01

    Along with the growing interest in water quality during the last decade, the need for data on all types of water-quality parameters has also increased. One parameter of particular interest, because of its many ramifications, is temperature. It influences many of the chemical and physical processes that take place in water. The solubility of gases--for example, oxygen and carbon dioxide--and the solution of mineral matter in water are functions of temperature. Such physical properties as density and viscosity vary with temperature. Oxidation of organic materials, as well as algal and bacterial growth, is promoted or retarded by favorable or unfavorable temperatures. Further, temperature bears on the utility of water: as a source of public water supplies; for industrial use, particularly if the water is used for cooling; and in the field of recreation involving contact sports, fishing, and fish culture. In recent years, temperature changes resulting from inflow of heated industrial waste, particularly effluent from power generating plants, have increased the need for temperature data to determine the degree of change, its effect on ecology, and the effect of any remedial action. Thus, because of the many extensive and intensive effects, a large amount of temperature data is collected on surface and ground waters by many agencies throughout the country. Moreover, because of its importance, there is a widespread interest in temperature even by those who are not active collectors of the data themselves. The industrialist, the manager, the public official, and others at one time or another may have need for temperature data and may well raise the questions: Who is collecting temperature data? What is the extent of the activity? Where are the data being collected? The purpose of this report is to answer these questions. The information in the report is confined to the activities of Federal and non-Federal agencies. It is based on information furnished to the Office of

  6. Effects of temperature and water stresses on germination of some ...

    African Journals Online (AJOL)

    Therefore, we opted for the Chetoui variety that better meets the conditions of stresses induced by low temperatures and water deficit. This best performing variety must have, throughout their development cycle, been tolerant to environmental stresses; which allows us to obtain early tools for discriminative selection between ...

  7. Effects of Hot Water Treatment and Temperature on Seedling ...

    African Journals Online (AJOL)

    An experiment was conducted at the Faculty of Agriculture, University of Maiduguri, to study the effect of hot water treatment and temperature on the morphological characteristics of Arabic gum. The experiment was laid out in a Randomized Complete Block Design in a factorial arrangement. The treatments included a ...

  8. Variability in estuarine water temperature gradients and influence on ...

    African Journals Online (AJOL)

    Structure and variability of water temperature gradients and potential influence on distribution of two tropical zooplankters (the mysid Mesopodopsis africana and the copepod Acartia natalensis) and their temperate congenerics (M. wooldridgei and A. longipatella) was investigated over a 10-year period in the Mgazi Estuary, ...

  9. Intelligent electrical outlet for collective load control

    Science.gov (United States)

    Lentine, Anthony L.; Ford, Justin R.; Spires, Shannon V.; Goldsmith, Steven Y.

    2015-10-27

    Various technologies described herein pertain to an electrical outlet that autonomously manages loads in a microgrid. The electrical outlet can provide autonomous load control in response to variations in electrical power generation supply in the microgrid. The electrical outlet includes a receptacle, a sensor operably coupled to the receptacle, and an actuator configured to selectively actuate the receptacle. The sensor measures electrical parameters at the receptacle. Further, a processor autonomously controls the actuator based at least in part on the electrical parameters measured at the receptacle, electrical parameters from one or more disparate electrical outlets in the microgrid, and a supply of generated electric power in the microgrid at a given time.

  10. Increasing Water Temperature Triggers Dominance of Small Freshwater Plankton.

    Directory of Open Access Journals (Sweden)

    Serena Rasconi

    Full Text Available Climate change scenarios predict that lake water temperatures will increase up to 4°C and rainfall events will become more intense and frequent by the end of this century. Concurrently, supply of humic substances from terrestrial runoff is expected to increase, resulting in darker watercolor ("brownification" of aquatic ecosystems. Using a multi-seasonal, low trophic state mesocosm experiment, we investigated how higher water temperature and brownification affect plankton community composition, phenology, and functioning. We tested the hypothesis that higher water temperature (+3°C and brownification will, a cause plankton community composition to shift toward small sized phytoplankton and cyanobacteria, and, b extend the length of the growing season entailing higher phytoplankton production later in the season. We demonstrate that the 3°C increase of water temperature favored the growth of heterotrophic bacteria and small sized autotrophic picophytoplankton cells with significantly higher primary production during warmer fall periods. However, 3X darker water (effect of brownification caused no significant changes in the plankton community composition or functioning relative to control conditions. Our findings reveal that increased temperature change plankton community structure by favoring smaller sized species proliferation (autotrophic phytoplankton and small size cladocerans, and increase primary productivity and community turnover. Finally, results of this multi-seasonal experiment suggest that warming by 3°C in aquatic ecosystems of low trophic state may cause planktonic food web functioning to become more dominated by fast growing, r-trait species (i.e., small sizes and rapid development.

  11. The influence of increased temperature of waters from Cernavoda NPP on underground water sources

    International Nuclear Information System (INIS)

    Isbasoiu, Eugen Constantin; Marinov, Anca Mariana; Moraru, Carina Nicoleta; Rizescu, Gheorghe

    1997-01-01

    The operation of Cernavoda NPP implies the change of thermal regime of waters in the Danube-Black Sea channel zone. The Danube water is used to cool the NPP systems before being delivered into channel and used in irrigations. The temperature increase of water in Cernavoda NPP installations is between 7 and 12 deg. C. The negative effects of this warming are: 1. limitation of water use for irrigations; 2. occurrence and persistence of fog in channel area; 3. thermal pollution of underground waters and limitation of underground potable water supply. The paper presents a general approach of thermal pollution problems of an aquifer and a mathematical model of forecasting the underground water temperature variation in Danube-Black Sea channel area. (authors)

  12. Combined diurnal variations of discharge and hydrochemistry of the Isunnguata Sermia outlet, Greenland Ice Sheet

    Science.gov (United States)

    Graly, Joseph; Harrington, Joel; Humphrey, Neil

    2017-05-01

    In order to examine daily cycles in meltwater routing and storage in the Isunnguata Sermia outlet of the Greenland Ice Sheet, variations in outlet stream discharge and in major element hydrochemistry were assessed over a 6-day period in July 2013. Over 4 days, discharge was assessed from hourly photography of the outlet from multiple vantages, including where midstream naled ice provided a natural gauge. pH, electrical conductivity, suspended sediment, and major element and anion chemistry were measured in samples of stream water collected every 3 h.Photography and stream observations reveal that although river width and stage have only slight diurnal variation, there are large diurnal changes in discharge shown by the doubling in width of what we term the active channel, which is characterized by large standing waves and fast flow. The concentration of dissolved solutes follows a sinusoidal diurnal cycle, except for large and variable increases in dissolved solutes during the stream's waning flow. Solute concentrations vary by ˜ 30 % between diurnal minima and maxima. Discharge maxima and minima lag temperature and surface melt by 3-7 h; diurnal solute concentration minima and maxima lag discharge by 3-6 h.This phase shift between discharge and solute concentration suggests that during high flow, water is either encountering more rock material or is stored in longer contact with rock material. We suggest that expansion of a distributed subglacial hydrologic network into seldom accessed regions during high flow could account for these phenomena, and for a spike of partial silicate reaction products during waning flow, which itself suggests a pressure threshold-triggered release of stored water.

  13. Forsmark site investigation. Monitoring of brook water levels, electrical conductivities, temperatures and discharges January-December 2009

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Per-Olof (Artesia Grundvattenkonsult (Sweden)); Juston, John (Juston Konsult (Sweden))

    2011-03-15

    This document reports the monitoring of water levels, electrical conductivities, temperatures and discharges at four brook discharge gauging stations, and the monitoring of water electrical conductivity at the outlet of Lake Bolundsfjaerden in the Forsmark area. The report presents data from 1 January through 31 December 2009 and is a continuation of reporting from Johansson and Juston (2007, 2009), which covered the periods from 1 April 2004 through 31 March 2007 and 1 April 2007 through 31 December 2008, respectively. Long-throated flumes equipped with automatically recording devices were used for the discharge measurements. Every c. 14 days the water depths at the upstream edge of the flumes were measured manually by a ruler as a check. Electrical conductivity and temperature were automatically recorded and these parameters were also measured manually every c. 14 days with the site investigation field devices. SKB's Hydro Monitoring System (HMS) was used to collect and store all data. From HMS quality assured data were transferred to SKB's primary database Sicada. Measurements of levels, electrical conductivities and temperatures were made every 10 minutes (every 30 minutes for electrical conductivity at the outlet of Lake Bolundsfjaerden). For the calculation of discharge, quality assured water level data from the flumes were used. The calculation procedure included consolidation of the time series to hourly averages, screening of data for removal of short-term spikes, noise and other data that were judged erroneous. After the calculations were performed, the results were delivered to Sicada. The amplitudes of water level variations during this reporting period were 0.26-0.33 m at the four stations. The mean electrical conductivities varied between 26 and 41 mS/m at the four discharge stations. The electrical conductivity at the outlet of Lake Bolundsfjaerden varied between 53 and 188 mS/m during the period with the higher values at the end of the

  14. Forsmark site investigation. Monitoring of brook water levels, electrical conductivities, temperatures and discharges January-December 2010

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Per-Olof (Artesia Grundvattenkonsult (Sweden)); Juston, John (Juston Konsult (Sweden))

    2011-06-15

    This document reports the monitoring of water levels, electrical conductivities, temperatures and discharges at four brook discharge gauging stations, and the monitoring of water electrical conductivity at the outlet of Lake Bolundsfjaerden in the Forsmark area. The report presents data from 1 January through 31 December 2010 and is a continuation of reporting from Johansson and Juston (2007, 2009, 2011), which covered the periods from 1 April 2004 through 31 March 2007, 1 April 2007 through 31 December 2008, and 1 January through 31 December 2009, respectively. Long-throated flumes equipped with automatically recording devices were used for the discharge measurements. Every c. 14 days the water depths at the upstream edge of the flumes were measured manually by a ruler as a check. Electrical conductivity and temperature were automatically recorded and these parameters were also measured manually every c. 14 days with the site investigation field devices. SKB's Hydro Monitoring System (HMS) was used to collect and store all data. From HMS quality assured data were transferred to SKB's primary database Sicada. Measurements of levels, electrical conductivities and temperatures were made every 10 minutes (every 30 minutes for electrical conductivity at the outlet of Lake Bolundsfjaerden). For the calculation of discharge, quality assured water level data from the flumes were used. The calculation procedure included consolidation of the time series to hourly averages, screening of data for removal of short-term spikes, noise and other data that were judged erroneous. After the calculations were performed, the results were delivered to Sicada. The amplitudes of water level variations during this reporting period were 0.41-0.55 m and the mean electrical conductivities varied between 23 and 39 mS/m at the four discharge stations. However, due to mal-function of measuring devices for electrical conductivity, data were missing for relatively long time periods. Due

  15. Simulating future water temperatures in the North Santiam River, Oregon

    Science.gov (United States)

    Buccola, Norman; Risley, John C.; Rounds, Stewart A.

    2016-01-01

    A previously calibrated two-dimensional hydrodynamic and water-quality model (CE-QUAL-W2) of Detroit Lake in western Oregon was used in conjunction with inflows derived from Precipitation-Runoff Modeling System (PRMS) hydrologic models to examine in-lake and downstream water temperature effects under future climate conditions. Current and hypothetical operations and structures at Detroit Dam were imposed on boundary conditions derived from downscaled General Circulation Models in base (1990–1999) and future (2059–2068) periods. Compared with the base period, future air temperatures were about 2 °C warmer year-round. Higher air temperature and lower precipitation under the future period resulted in a 23% reduction in mean annual PRMS-simulated discharge and a 1 °C increase in mean annual estimated stream temperatures flowing into the lake compared to the base period. Simulations incorporating current operational rules and minimum release rates at Detroit Dam to support downstream habitat, irrigation, and water supply during key times of year resulted in lower future lake levels. That scenario results in a lake level that is above the dam’s spillway crest only about half as many days in the future compared to historical frequencies. Managing temperature downstream of Detroit Dam depends on the ability to blend warmer water from the lake’s surface with cooler water from deep in the lake, and the spillway is an important release point near the lake’s surface. Annual average in-lake and release temperatures from Detroit Lake warmed 1.1 °C and 1.5 °C from base to future periods under present-day dam operational rules and fill schedules. Simulated dam operations such as beginning refill of the lake 30 days earlier or reducing minimum release rates (to keep more water in the lake to retain the use of the spillway) mitigated future warming to 0.4 and 0.9 °C below existing operational scenarios during the critical autumn spawning period for endangered

  16. Simulating future water temperatures in the North Santiam River, Oregon

    Science.gov (United States)

    Buccola, Norman L.; Risley, John C.; Rounds, Stewart A.

    2016-04-01

    A previously calibrated two-dimensional hydrodynamic and water-quality model (CE-QUAL-W2) of Detroit Lake in western Oregon was used in conjunction with inflows derived from Precipitation-Runoff Modeling System (PRMS) hydrologic models to examine in-lake and downstream water temperature effects under future climate conditions. Current and hypothetical operations and structures at Detroit Dam were imposed on boundary conditions derived from downscaled General Circulation Models in base (1990-1999) and future (2059-2068) periods. Compared with the base period, future air temperatures were about 2 °C warmer year-round. Higher air temperature and lower precipitation under the future period resulted in a 23% reduction in mean annual PRMS-simulated discharge and a 1 °C increase in mean annual estimated stream temperatures flowing into the lake compared to the base period. Simulations incorporating current operational rules and minimum release rates at Detroit Dam to support downstream habitat, irrigation, and water supply during key times of year resulted in lower future lake levels. That scenario results in a lake level that is above the dam's spillway crest only about half as many days in the future compared to historical frequencies. Managing temperature downstream of Detroit Dam depends on the ability to blend warmer water from the lake's surface with cooler water from deep in the lake, and the spillway is an important release point near the lake's surface. Annual average in-lake and release temperatures from Detroit Lake warmed 1.1 °C and 1.5 °C from base to future periods under present-day dam operational rules and fill schedules. Simulated dam operations such as beginning refill of the lake 30 days earlier or reducing minimum release rates (to keep more water in the lake to retain the use of the spillway) mitigated future warming to 0.4 and 0.9 °C below existing operational scenarios during the critical autumn spawning period for endangered salmonids. A

  17. Study on partial overheat of the isolated phase busbar outlet box in Qinshan NPP phase Ⅱ

    International Nuclear Information System (INIS)

    Tang Fangxuan; Zhang Jian; Zeng Limin; Bao Yanxing; Zhang Lie; Yang Yuemin

    2013-01-01

    This paper recommended the structure of the isolated phase busbar outlet box installed in Qinshan II. The study on partial overheat of the outlet box shows that the ultimate causes are the loss of concentrated eddy current and short of cooling. So the improvement principles of 'distributing eddy current, cutting off inductive circle current and strengthening of ventilation' were determined. A new structure test outlet box was designed and manufactured, and the temperature rising experiment was carried out. Some alterations were made in the new structure outlet box, e.g. isolating materials were added between side plates of the upper outlet box, and also between the upper and lower outlet box. Two cooling blowers were added to the upper outlet box. After putting into operation, the hot-spot temperature of the new outlet box was greatly lowered down. Thus the operation environment was improved, and the operation safety ensured. It can be useful references for analyzing and dealing with similar problems. (authors)

  18. Temperature/pressure and water vapor sounding with microwave spectroscopy

    Science.gov (United States)

    Muhleman, D. O.; Janssen, M. A.; Clancy, R. T.; Gulkis, S.; Mccleese, D. J.; Zurek, R.; Haberle, R. M.; Frerking, M.

    1992-01-01

    Two intense microwave spectra lines exist in the martian atmosphere that allow unique sounding capabilities: water vapor at 183 GHz and the (2-1) rotational line of CO at 230 GHz. Microwave spectra line sounding is a well-developed technique for the Earth's atmosphere for sounding from above from spacecraft and airplanes, and from below from fixed surface sites. Two simple instruments for temperature sounding on Mars (the CO line) and water vapor measurements are described. The surface sounder proposed for the MESUR sites is designed to study the boundary layer water vapor distribution and the temperature/pressure profiles with vertical resolution of 0.25 km up to 1 km with reduced resolution above approaching a scale height. The water channel will be sensitive to a few tenths of a micrometer of water and the temperature profile will be retrieved to an accuracy between 1 and 2 K. The latter is routinely done on the Earth using oxygen lines near 60 GHz. The measurements are done with a single-channel heterodyne receiver looking into a 10-cm mirror that is canned through a range of elevation angles plus a target load. The frequency of the receiver is sweep across the water and CO lines generating the two spectra at about 1-hr intervals throughout the mission. The mass and power for the proposed instrument are 2 kg and 5-8 W continuously. The measurements are completely immune to the atmospheric dust and ice particle loads. It was felt that these measurements are the ultimate ones to properly study the martian boundary layer from the surface to a few kilometers. Sounding from above requires an orbiting spacecraft with multichannel microwave spectrometers such as the instrument proposed for MO by a subset of the authors, a putative MESUR orbiter, and a proposed Discovery mission called MOES. Such an instrument can be built with less than 10 kg and use less than 15 W. The obvious advantage of this approach is that the entire atmosphere can be sounded for temperature and

  19. Achieving low return temperature for domestic hot water preparation by ultra-low-temperature district heating

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Svendsen, Svend

    2017-01-01

    District heating (DH) is a cost-effective method of heat supply, especially to area with high heat density. Ultra-low-temperature district heating (ULTDH) is defined with supply temperature at 35-45 degrees C. It aims at making utmost use of the available low-temperature energy sources. In order...... to achieve high efficiency of the ULTDH system, the return temperature should be as low as possible. For the energy-efficient buildings in the future, it is feasible to use ULTDH to cover the space heating demand. However, considering the comfort and hygiene requirements of domestic hot water (DHW...... lower return temperature and higher efficiency for DHW supply, an innovative substation was devised, which replaced the bypass with an instantaneous heat exchanger and a micro electric storage tank. The energy performance of the proposed substation and the resulting benefits for the DH system...

  20. Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species.

    Science.gov (United States)

    Firkus, Tyler; Rahel, Frank J; Bergman, Harold L; Cherrington, Brian D

    2018-02-01

    We examined the spawning success of Fathead Minnows (Pimephales promelas) and Johnny Darters (Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

  1. Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species

    Science.gov (United States)

    Firkus, Tyler; Rahel, Frank J.; Bergman, Harold L.; Cherrington, Brian D.

    2018-02-01

    We examined the spawning success of Fathead Minnows ( Pimephales promelas) and Johnny Darters ( Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

  2. A simplified model to predict diurnal water temperature dynamics in a shallow tropical water pool

    NARCIS (Netherlands)

    Paaijmans, K.P.; Heusinkveld, B.G.; Jacobs, A.F.G.

    2008-01-01

    Water temperature is a critical regulator in the growth and development of malaria mosquito immatures, as they are poikilothermic. Measuring or estimating the diurnal temperature ranges to which these immatures are exposed is of the utmost importance, as these immatures will develop into adults that

  3. Laboratory determination of normal operating flow rates with enlarged outlet fittings -- BDF reactors

    Energy Technology Data Exchange (ETDEWEB)

    Waters, E.D.

    1960-02-02

    Experiments have been conducted in the Hydraulics Laboratory, at the request of IPD`s Mechanical Development-A Operation, to determine the energy losses of various enlarged outlet fitting combinations. These experiments were conducted an steady state runs and allow the determination of the normal operating point (flow rate) of a reactor process channel under selected conditions of front header pressure and fuel charge. No attempt is made to make a mechanical or economic evaluation of the particular fitting combinations, although observations were noted which might bear on this evaluation. It is very important for the reader to bear in mind that changing outlet fittings will definitely affect the reactor tube power limits and outlet vater temperature limits. The size of the outlet fittings largely determines the present outlet temperature limits of the old reactors. The flow characteristics of these present fittings cause some degree of pressurization to suppress boiling on the fuel charge and also cause dual Panellit trip protection for certain flow changes and for power surges. Enlargement of the outlet fittings may actually reduce the allowable outlet coolant temperature limits. Since these effects cannot be determined on the apparatus used in these experiments, a complete discussion of this point is not included in this report. However, the seriousness of these effects should be known and carefully analyzed before a final selection of enlarged outlet fittings in made. This report will be one of a series. New reports in the series will be issued as data are obtained for other such outlet fitting combinations or for new concepts of outlet fitting assemblies such as the new nozzle being developed by C. E. Trantz for use on F-reactor stuck gunbarrel tubes.

  4. Feasibility of active solar water heating systems with evacuated tube collector at different operational water temperatures

    International Nuclear Information System (INIS)

    Mazarrón, Fernando R.; Porras-Prieto, Carlos Javier; García, José Luis; Benavente, Rosa María

    2016-01-01

    Highlights: • Analysis of the feasibility of an active solar water-heating system. • Profitability decreases as the required water temperature increases. • The number of collectors that maximizes profitability depends on the required temperature. • Investment in a properly sized system generates savings between 23% and 15%. • Fuel consumption can be reduced by 70%. - Abstract: With rapid advancements in society, higher water temperatures are needed in a number of applications. The demand for hot water presents a great variability with water required at different temperatures. In this study, the design, installation, and evaluation of a solar water heating system with evacuated tube collector and active circulation has been carried out. The main objective is to analyze how the required tank water temperature affects the useful energy that the system is capable of delivering, and consequently its profitability. The results show how the energy that is collected and delivered to the tank decreases with increasing the required temperature due to a lower performance of the collector and losses in the pipes. The annual system efficiency reaches average values of 66%, 64%, 61%, 56%, and 55% for required temperatures of 40 °C, 50 °C, 60 °C, 70 °C, and 80 °C. As a result, profitability decreases as temperature increases. The useful energy, and therefore the profitability, will decrease if the demand is not distributed throughout the day or focused on the end of the day. The system’s profitability was determined in two cases: considering maximum profitability of the system, assuming 100% utilization of useful energy (scenario 1); assuming a particular demand, considering that on many days all the useful energy the system can supply is not used (scenario 2). The analysis shows that through proper sizing of the system, optimizing the number of solar collectors, the investment in the solar system can be profitable with similar profitability values in the two

  5. Temperature dependence on sodium-water chemical reaction

    International Nuclear Information System (INIS)

    Tamura, Kenta; Deguchi, Yoshihiro; Suzuki, Koichi; Takata, Takashi; Yamaguchi, Akira; Kikuchi, Shin; Ohshima, Hiroyuki

    2012-01-01

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. A quasi one-dimensional flame model is also applied to a sodium-water counter-flow reaction field. Temperature, H 2 , H 2 O, OH, Na and Particulate matter were measured using laser induced fluorescence and CARS in the counter-flow reaction field. The temperature of the reaction field was also modified to reduce the condensation of Na in the reaction zone. (author)

  6. Socioeconomic determinants of exposure to alcohol outlets.

    Science.gov (United States)

    Morrison, Christopher; Gruenewald, Paul J; Ponicki, William R

    2015-05-01

    Alcohol outlets tend to be located in lower income areas, exposing lower income populations to excess risks associated with alcohol sales through these establishments. The objective of this study was to test two hypotheses about the etiology of these differential exposures based on theories of the economic geography of retail markets: (a) outlets will locate within or near areas of high alcohol demand, and (b) outlets will be excluded from areas with high land and structure rents. Data from the 2010 National Drug Strategy Household Survey were used to develop a surrogate for alcohol demand (i.e., market potential) at two census geographies for the city of Melbourne, Australia. Bayesian conditional autoregressive Poisson models estimated multilevel spatial relationships between counts of bars, restaurants, and off-premise outlets and market potential, income, and zoning ordinances (Level 1: n = 8,914). Market potentials were greatest in areas with larger older age, male, English-speaking, high-income populations. Independent of zoning characteristics, greater numbers of outlets appeared in areas with greater market potentials and the immediately surrounding areas. Greater income excluded outlets in local and surrounding areas. These findings are consistent with the hypothesis that alcohol outlets are located in areas with high demand and are excluded from high-income areas. These processes appear to take place at relatively small geographic scales, encourage the concentration of outlets in specific low-income areas, and represent a very general economic process likely to take place in communities throughout the world.

  7. Effects of temperature and salinity on light scattering by water

    Science.gov (United States)

    Zhang, Xiaodong; Hu, Lianbo

    2010-04-01

    A theoretical model on light scattering by water was developed from the thermodynamic principles and was used to evaluate the effects of temperature and salinity. The results agreed with the measurements by Morel within 1%. The scattering increases with salinity in a non-linear manner and the empirical linear model underestimate the scattering by seawater for S < 40 psu. Seawater also exhibits an 'anomalous' scattering behavior with a minimum occurring at 24.64 °C for pure water and this minimum increases with the salinity, reaching 27.49 °C at 40 psu.

  8. Grey water treatment in UASB reactor at ambient temperature.

    Science.gov (United States)

    Elmitwalli, T A; Shalabi, M; Wendland, C; Otterpohl, R

    2007-01-01

    In this paper, the feasibility of grey water treatment in a UASB reactor was investigated. The batch recirculation experiments showed that a maximum total-COD removal of 79% can be obtained in grey-water treatment in the UASB reactor. The continuous operational results of a UASB reactor treating grey water at different hydraulic retention time (HRT) of 20, 12 and 8 hours at ambient temperature (14-24 degrees C) showed that 31-41% of total COD was removed. These results were significantly higher than that achieved by a septic tank (11-14%), the most common system for grey water pre-treatment, at HRT of 2-3 days. The relatively lower removal of total COD in the UASB reactor was mainly due to a higher amount of colloidal COD in the grey water, as compared to that reported in domestic wastewater. The grey water had a limited amount of nitrogen, which was mainly in particulate form (80-90%). The UASB reactor removed 24-36% and 10-24% of total nitrogen and total phosphorus, respectively, in the grey water, due to particulate nutrients removal by physical entrapment and sedimentation. The sludge characteristics of the UASB reactor showed that the system had stable performance and the recommended HRT for the reactor is 12 hours.

  9. Temperature dependence of bulk viscosity in water using acoustic spectroscopy

    International Nuclear Information System (INIS)

    Holmes, M J; Parker, N G; Povey, M J W

    2011-01-01

    Despite its fundamental role in the dynamics of compressible fluids, bulk viscosity has received little experimental attention and there remains a paucity of measured data. Acoustic spectroscopy provides a robust and accurate approach to measuring this parameter. Working from the Navier-Stokes model of a compressible fluid one can show that the bulk viscosity makes a significant and measurable contribution to the frequency-squared acoustic attenuation. Here we employ this methodology to determine the bulk viscosity of Millipore water over a temperature range of 7 to 50 0 C. The measured attenuation spectra are consistent with the theoretical predictions, while the bulk viscosity of water is found to be approximately three times larger than its shear counterpart, reinforcing its significance in acoustic propagation. Moreover, our results demonstrate that this technique can be readily and generally applied to fluids to accurately determine their temperature dependent bulk viscosities.

  10. The effect of water temperature and water hardness on reproductive indicators Hemichromis lifalili

    Directory of Open Access Journals (Sweden)

    Ján Kopecký

    2014-05-01

    Full Text Available In this work we investigated the effect of temperature and water hardness on reproductive indicators Hemichromis lifalili in aquarium conditions. From bred individuals we have compiled three breeding pairs, which we placed in aquariums with different temperature and water hardness. In experimental pairs, we evaluated these reproductive variables: number of spawning eggs, the number of hatched, dead and bred individuals. Experiments showed that 28 °C, and 8 °N water hardness increased the reproductive activity of fish and the quantity of fish hatched. Decreasing temperature in the tanks was proportionally increased the number of unhatched individuals, and the mortality. The mortality was 88 pieces per swab at 25 °C. Water at 28 °C and 8 °N hardness was reached swab to 1200 eggs pieces.

  11. Estimation of precipitable water from surface dew point temperature

    International Nuclear Information System (INIS)

    Abdel Wahab, M.; Sharif, T.A.

    1991-09-01

    The Reitan (1963) regression equation which is of the form lnw=a+bT d has been examined and tested to estimate precipitable water content from surface dew point temperature at different locations. The study confirms that the slope of this equation (b) remains constant at the value of .0681 deg. C., while the intercept (a) changes rapidly with the latitude. The use of the variable intercept can improve the estimated result by 2%. (author). 6 refs, 4 figs, 3 tabs

  12. Solubility of corrosion products in high temperature water

    International Nuclear Information System (INIS)

    Srinivasan, M.P.; Narasimhan, S.V.

    1995-01-01

    A short review of solubility of corrosion products at high temperature in either neutral or alkaline water as encountered in BWR, PHWR and PWR primary coolant reactor circuits is presented in this report. Based on the available literature, various experimental techniques involved in the study of the solubility, theory for fitting the solubility data to the thermodynamic model and discussion of the published results with a scope for future work have been brought out. (author). 17 refs., 7 figs

  13. Temperature effect on water absorption in an improved periwinkle ...

    African Journals Online (AJOL)

    Studies have been carried out on the water absorption of the improved periwinkle reinforced cement stabilized lateritic bricks. These bricks were produced at different cement to laterite to periwinkle ratio of 1:3:1, 2:3:1, 3:3:1, 3:2:1, 3:1:1, and fired at an elevated temperature of 10000C and 11500C, respectively. From the ...

  14. Corrosion behaviour of construction materials for high temperature water electrolysers

    Energy Technology Data Exchange (ETDEWEB)

    Nikiforov, A.; Petruchina, I.; Christensen, E.; Bjerrum, N.J.; Tomas-Garcya, A.L. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemistry, Materials Science Group

    2010-07-01

    This presentation reported on a study in which the feasibility of using different corrosion resistant stainless steels as a possible metallic bipolar plate and construction material was evaluated in terms of corrosion resistance under conditions corresponding to the conditions in high temperature proton exchange membrane (PEM) water electrolysers (HTPEMWE). PEM water electrolysis technology has been touted as an effective alternative to more conventional alkaline water electrolysis. Although the energy efficiency of this technology can be increased considerably at temperatures above 100 degrees C, this increases the demands to all the used materials with respect to corrosion stability and thermal stability. In this study, Ni-based alloys as well as titanium and tantalum samples were exposed to anodic polarization in 85 per cent phosphoric acid electrolyte solution. Tests were performed at 80 and 120 degrees C to determine the dependence of corrosion speed and working temperature. Platinum and gold plates were also tested for a comparative evaluation. Steady-state voltammetry was used along with scanning electron microscopy and energy-dispersive X-ray spectroscopy. Titanium showed the poorest corrosion resistance, while Ni-based alloys showed the highest corrosion resistance, with Inconel R 625 being the most promising alloy for the bipolar plate of an HTPEMWE. 3 refs., 1 tab., 2 figs.

  15. Whole body immersion and hydromineral homeostasis: effect of water temperature.

    Science.gov (United States)

    Jimenez, Chantal; Regnard, Jacques; Robinet, Claude; Mourot, Laurent; Gomez-Merino, Danielle; Chennaoui, Mounir; Jammes, Yves; Dumoulin, Gilles; Desruelle, Anne-Virginie; Melin, Bruno

    2010-01-01

    This experiment was designed to assess the effects of prolonged whole body immersion (WBI) in thermoneutral and cold conditions on plasma volume and hydromineral homeostasis.10 navy "combat swimmers" performed three static 6-h immersions at 34 degrees C (T34), 18 degrees C (T18) and 10 degrees C (T10). Rectal temperature, plasma volume (PV) changes, plasma proteins, plasma and urine ions, plasma osmolality, renin, aldosterone and antidiuretic hormone (ADH) were measured. Results show that compared to pre-immersion levels, PV decreased throughout WBI sessions, the changes being markedly accentuated in cold conditions. At the end of WBI, maximal PV variations were -6.9% at T34, -14.3% at T18, and -16.3% at T10. Plasma osmolality did not change during and after T34 immersion, while hyperosmolality was present at the end of T18 immersion and began after only 1 h of T10 immersion. In the three temperature conditions, significant losses of water (1.6-1.7 l) and salt (6-8 g) occurred and were associated with similar increases in osmolar and free water clearances. Furthermore, T18 and T10 immersions increased the glomerular filtration rate. There was little or no change in plasma renin and ADH, while the plasma level of aldosterone decreased equally in the three temperature conditions. In conclusion, our data indicate that cold water hastened PV changes induced by immersion, and increased the glomerular filtration rate, causing larger accumulated water losses. The iso-osmotic hypovolemia may impede the resumption of baseline fluid balance. Results are very similar to those repeatedly described by various authors during head-out water immersion.

  16. HEAT PUMP USING SUBSOIL WATERS AS LOW TEMPERATURE HEAT SOURCE

    Directory of Open Access Journals (Sweden)

    Denysova Alla

    2015-08-01

    Full Text Available One of the basic directions of perfection of heat supply systems is the tendency of transition to the low-temperature heating systems based on application of heat pump installations. We consider heat supply system with heat pump installations using subsoil waters. Numerical simulation of thermal processes in the elements of a single-stage and double-stage heat pump systems has been worked out. Values of depths of wells and their quantity, necessary for effective operation of the offered installations, and values of capacity of electric water pumps for subsoil waters unit are calculated. Capacity of compressor electric drive and coefficient of performance of heat pump for the conditions of the city of Odessa are presented.

  17. Discussion on Boiler Efficiency Correction Method with Low Temperature Economizer-Air Heater System

    Science.gov (United States)

    Ke, Liu; Xing-sen, Yang; Fan-jun, Hou; Zhi-hong, Hu

    2017-05-01

    This paper pointed out that it is wrong to take the outlet flue gas temperature of low temperature economizer as exhaust gas temperature in boiler efficiency calculation based on GB10184-1988. What’s more, this paper proposed a new correction method, which decomposed low temperature economizer-air heater system into two hypothetical parts of air preheater and pre condensed water heater and take the outlet equivalent gas temperature of air preheater as exhaust gas temperature in boiler efficiency calculation. This method makes the boiler efficiency calculation more concise, with no air heater correction. It has a positive reference value to deal with this kind of problem correctly.

  18. From Space to the Rocky Intertidal: Using NASA MODIS Sea Surface Temperature and NOAA Water Temperature to Predict Intertidal Logger Temperature

    Directory of Open Access Journals (Sweden)

    Jessica R. P. Sutton

    2017-02-01

    Full Text Available The development of satellite-derived datasets has greatly facilitated large-scale ecological studies, as in situ observations are spatially sparse and expensive undertakings. We tested the efficacy of using satellite sea surface temperature (SST collected by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS and local water temperature collected from NOAA buoys and onshore stations to estimate submerged intertidal mussel logger temperatures. Daily SST and local water temperatures were compared to mussel logger temperatures at five study sites located along the Oregon coastline. We found that satellite-derived SSTs and local water temperatures were similarly correlated to the submerged mussel logger temperatures. This finding suggests that satellite-derived SSTs may be used in conjunction with local water temperatures to understand the temporal and spatial variation of mussel logger temperatures. While there are limitations to using satellite-derived temperature for ecological studies, including issues with temporal and spatial resolution, our results are promising.

  19. Temperature effects studies in light water reactor lattices

    International Nuclear Information System (INIS)

    Erradi, Lahoussine.

    1982-02-01

    The CREOLE experiments performed in the EOLE critical facility located in the Nuclear Center of CADARACHE - CEA (UO 2 and UO 2 -PuO 2 lattice reactivity temperature coefficient continuous measurements between 20 0 C and 300 0 C; integral measurements by boron equivalent effect in the moderator; water density effects measurements with the use of over cladding aluminium tubes to remove moderator) allow to get an interesting and complete information on the temperature effects in the light water reactor lattices. A very elaborated calcurated scheme using the transport theory and the APOLLO cross sections library, has been developed. The analysed results of the whole lot of experiments show that the discrepancy between theory and experiment strongly depends on the temperature range and on the type of lattices considered. The error is mainly linked with the thermal spectrum effects. A study on the temperature coefficient sensitivity to the different cell neutron parameters has shown that only the shapes of the 235 U and 238 U thermal cross sections have enough weight and uncertainty margins to explain the observed experimental/calculation bias. Instead of arbitrarily fitting the identified wrong data on the calculation of the reactivity temperature coefficient we have defined a procedure of modification of the cross sections based on the consideration of the basic nuclear data: resonance parameters and associated statistic laws. The implementation of this procedure has led to propose new thermal cross sections sets for 235 U and 238 U consistent with the uncertainty margins associated with the previously accepted values and with some experimental data [fr

  20. Effects of temperature on SCC propagation in high temperature water injected with hydrogen peroxide

    International Nuclear Information System (INIS)

    Nakano, Junichi; Sato, Tomonori; Kato, Chiaki; Yoshiyuki, Kaji; Yamamoto, Masahiro; Tsukada, Takashi

    2012-09-01

    To understand the stress corrosion cracking (SCC) behaviour of austenitic stainless steels (SSs) in the boiling water reactor (BWR) coolant environment, it is significant to investigate the effect of hydrogen peroxide (H 2 O 2 ) produced by the radiolysis of water on SCC under the various water chemistry and operational conditions. At the start-up or shut-down periods, for example, the conditions of radiation and temperature on the structural materials are different from those during the plant normal operation, and may be influencing on SCC behaviour. Therefore, the effect of temperature on SCC in high temperature water injected with H 2 O 2 was evaluated by SCC propagation test at the present study. Oxide films on the metal surface in crack were examined and the thermal equilibrium diagram was calculated to estimate the environmental situation in the crack. On the thermally sensitized type 304 SS, crack growth tests were conducted in high temperature water injected with H 2 O 2 to simulate water radiolysis in the core. Small CT type specimens with a width of 15.5 mm and thickness of 6.2 mm were machined from the sensitized SS. SCC growth tests were conducted in high temperature water injected with 100 ppb H 2 O 2 at 453 and 561 K. To minimize H 2 O 2 decomposition by a contact with metal surface of autoclave, the CT specimen was isolated from inner surface of the autoclave by the inner modules made of polytetrafluoroethylene (PTFE), and PTFE lining was also used for the inner surface of inlet and sampling tubes. Base on the measurement of sampled water, it was confirmed that 80-90 % of injected H 2 O 2 remained around the CT specimen in autoclave. Constant load at initial K levels of 11-20 MPam 1/2 was applied to the CT specimens during crack growth tests. After crack growth tests, CT specimens were split into two pieces on the plane of crack propagation. Scanning electron microscope (SEM) examination and laser Raman spectroscopy for outer oxide layer of oxide

  1. General corrosion of carbon steels in high temperature water

    International Nuclear Information System (INIS)

    Gras, J.M.

    1994-04-01

    This short paper seeks to provide a summary of the main knowledge about the general corrosion of carbon steels in high temperature water. In pure water or slightly alkaline deaerated water, steels develop a protective coating of magnetite in a double layer (Potter and Mann oxide) or a single layer (Bloom oxide). The morphology of the oxide layer and the kinetics of corrosion depend on the test parameters controlling the solubility of iron. The parameters exercising the greatest influence are partial hydrogen pressure and mass transfer: hydrogen favours the solubilization of the magnetite; the entrainment of the dissolved iron prevents a redeposition of magnetite on the surface of the steel. Cubic or parabolic in static conditions, the kinetics of corrosion tends to be linear in dynamic conditions. In dynamic operation, corrosion is at least one order of magnitude lower in water with a pH of 10 than in pure water with a pH of 7. The activation energy of corrosion is 130 kJ/mol (31 kcal/mol). This results in the doubling of corrosion at around 300 deg C for a temperature increase of 15 deg C. Present in small quantities (100-200 ppb), oxygen decreases general corrosion but increases the risk of pitting corrosion - even for a low chloride content - and stress corrosion cracking or corrosion-fatigue. The steel composition has probably an influence on the kinetics of corrosion in dynamic conditions; further work would be required to clarify the effect of some residual elements. (author). 31 refs., 9 figs., 2 tabs

  2. The effects of fire temperatures on water soluble heavy metals.

    Science.gov (United States)

    Pereira, P.; Ubeda, X.; Martin, D. A.

    2009-04-01

    Fire ash are majority composed by base cations, however the mineralized organic matter, led also available to transport a higher quantity of heavy metals that potentially could increase a toxicity in soil and water resources. The amount availability of these elements depend on the environment were the fire took place, burning temperature and combusted tree specie. The soil and water contamination from fire ash has been neglected, because the majority of studies are focused on base cations dynamic. Our research, beside contemplate major elements, is focused in to study the behavior of heavy metals released from ash slurries created at several temperatures under laboratory environment, prescribed fires and wildland fires. The results presented in these communication are preliminary and study the presence of Aluminium (Al3+), Manganese (Mn2+), Iron (Fe2+) and Zinc (Zn2+) of ash slurries generated in laboratory environment at several temperatures (150°, 200°, 250°, 300°, 350°, 400°,450°, 500°, 550°C) from Quercus suber, Quercus robur, Pinus pinea and Pinus pinaster and from a low medium temperature prescribed fire in a forest dominated Quercus suber trees. We observed that ash produced at lower and medium temperatures (Pinus ashes. Fe2+ and Zn2+ showed a reduced concentration in test solution in relation to unburned sample at all temperatures of exposition. In the results obtained from prescribed fire, we identify a higher release of Al3+ and a decrease of the remain elements. The solubilization of these elements are related with pH levels and ash calcite content, because their ability to capture ions in solution. Moreover, the amount and the type of ions released in relation to unburned sample vary in each specie. In this study Al3+ release is related with Quercus species and Mn2+ with Pinus species. Fire ashes can be an environmental problem, because at long term can increase soil acidity. After all base cations have being leached, pH values decrease, and

  3. Coolant mixing in the LMFBR outlet plenum

    International Nuclear Information System (INIS)

    Chen, Y.B.; Golay, M.W.

    1977-06-01

    Small scale experiments involving water flows are used to provide mean flow and turbulence field data for LMFBR outlet plenum flows. Measurements are performed at Reynolds Number (Re) values of 33000 and 70000 in a 1/15-scale FFTF geometry and at Re = 35000 in a 3/80-scale CRBR geometry. The experimental behavior is predicted using two different turbulence model computer programs, TEACH-T and VARR-II. It is found that the qualitative nature of the flow field within the plenum depends strongly upon the distribution of the mean inlet velocity field, upon the degree of inlet turbulence, and upon the turbulence momentum exchange model used in the calculations. It is found in the FFTF geometry that the TEACH-T predictions are better than that of VARR-II, and in the CRBR geometry neither code provides a good prediction of the observed behavior. From the sensitivity analysis, it is found that the production and dissipation of turbulence are the dominant terms in the transport equations for turbulent kinetic energy and turbulent energy dissipation rate, and the diffusion terms are relatively small. From the same study a new set of empirical constants for the turbulence model is evolved for the prediction of plenum flows

  4. SCC Initiation Testing of Alloy 600 in High Temperature Water

    Science.gov (United States)

    Etien, Robert A.; Richey, Edward; Morton, David S.; Eager, Julie

    Stress corrosion cracking (SCC) initiation tests have been conducted on Alloy 600 at temperatures from 304 to 367°C. Tests were conducted with in-situ monitored smooth tensile specimens under a constant load in hydrogenated environments. A reversing direct current electric potential drop (EPD) system was used for all of the tests to detect SCC initiation. Tests were conducted to examine the effects of stress (and strain), coolant hydrogen, and temperature on SCC initiation time. The thermal activation energy of SCC initiation was measured as 103 ± 18 kJ/mol in hydrogenated water, which is similar to the thermal activation energy for SCC growth. Results suggest that the fundamental mechanical parameter which controls SCC initiation is plastic strain not stress. SCC initiation was shown to have a different sensitivity than SCC growth to dissolved hydrogen level. Specifically, SCC initiation time appears to be relatively insensitive to hydrogen level in the nickel stability region.

  5. Development of solid electrolytes for water electrolysis at higher temperature

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A. [Florida Solar Energy Center, Cocoa, FL (United States)

    1996-10-01

    This report describes efforts in developing new solid polymer electrolytes that will enable operation of proton exchange membrane electrolyzers at higher temperatures than are currently possible. Several ionomers have been prepared from polyetheretherketone (PEEK), polyethersulfone (PES), and polyphenylquinoxaline (PPQ) by employing various sulfonation procedures. By controlling the extent of sulfonation, a range of proton conductivities could be achieved, whose upper limit actually exceeded that of commercially available perfluoralkyl sulfonates. Thermoconductimetric analysis of samples at various degrees of sulfonation showed an inverse relationship between conductivity and maximum operating temperature. This was attributed to the dual effect of adding sulfonate groups to the polymer: more acid groups produce more protons for increased conductivity, but they also increase water uptake, which mechanically weakens the membrane. This situation was exacerbated by the limited acidity of the aromatic sulfonic acids (pK{sub A} {approx} 2-3). The possibility of using partial fluorination to raise the acid dissociation constant is discussed.

  6. An operational analysis of Lake Surface Water Temperature

    Directory of Open Access Journals (Sweden)

    Emma K. Fiedler

    2014-07-01

    Full Text Available Operational analyses of Lake Surface Water Temperature (LSWT have many potential uses including improvement of numerical weather prediction (NWP models on regional scales. In November 2011, LSWT was included in the Met Office Operational Sea Surface Temperature and Ice Analysis (OSTIA product, for 248 lakes globally. The OSTIA analysis procedure, which has been optimised for oceans, has also been used for the lakes in this first version of the product. Infra-red satellite observations of lakes and in situ measurements are assimilated. The satellite observations are based on retrievals optimised for Sea Surface Temperature (SST which, although they may introduce inaccuracies into the LSWT data, are currently the only near-real-time information available. The LSWT analysis has a global root mean square difference of 1.31 K and a mean difference of 0.65 K (including a cool skin effect of 0.2 K compared to independent data from the ESA ARC-Lake project for a 3-month period (June to August 2009. It is demonstrated that the OSTIA LSWT is an improvement over the use of climatology to capture the day-to-day variation in global lake surface temperatures.

  7. Carbon dioxide and water vapor high temperature electrolysis

    Science.gov (United States)

    Isenberg, Arnold O.; Verostko, Charles E.

    1989-01-01

    The design, fabrication, breadboard testing, and the data base obtained for solid oxide electrolysis systems that have applications for planetary manned missions and habitats are reviewed. The breadboard tested contains sixteen tubular cells in a closely packed bundle for the electrolysis of carbon dioxide and water vapor. The discussion covers energy requirements, volume, weight, and operational characteristics related to the measurement of the reactant and product gas compositions, temperature distribution along the electrolyzer tubular cells and through the bundle, and thermal energy losses. The reliability of individual cell performance in the bundle configuration is assessed.

  8. Room temperature synthesis of water-repellent polystyrene nanocomposite coating

    International Nuclear Information System (INIS)

    Guo Yonggang; Jiang Dong; Zhang Xia; Zhang Zhijun; Wang Qihua

    2010-01-01

    A stable superhydrophobic polystyrene nanocomposite coating was fabricated by means of a very simple and easy method. The coating was characterized by scanning electron microscopy and X-ray photoelectron spectrum. The wettability of the products was also investigated. By adding the surface-modified SiO 2 nanoparticles, the wettability of the coating changed to water-repellent superhydrophobic, not only for pure water, but also for a wide pH range of corrosive liquids. The influence of the drying temperature and SiO 2 content on the wettability of the nanocomposite coating was also investigated. It was found that both factors had little or no significant effect on the wetting behavior of the coating surface.

  9. Socioeconomic Determinants of Exposure to Alcohol Outlets

    Science.gov (United States)

    Morrison, Christopher; Gruenewald, Paul J.; Ponicki, William R.

    2015-01-01

    Objective: Alcohol outlets tend to be located in lower income areas, exposing lower income populations to excess risks associated with alcohol sales through these establishments. The objective of this study was to test two hypotheses about the etiology of these differential exposures based on theories of the economic geography of retail markets: (a) outlets will locate within or near areas of high alcohol demand, and (b) outlets will be excluded from areas with high land and structure rents. Method: Data from the 2010 National Drug Strategy Household Survey were used to develop a surrogate for alcohol demand (i.e., market potential) at two census geographies for the city of Melbourne, Australia. Bayesian conditional autoregressive Poisson models estimated multilevel spatial relationships between counts of bars, restaurants, and off-premise outlets and market potential, income, and zoning ordinances (Level 1: n = 8,914). Results: Market potentials were greatest in areas with larger older age, male, English-speaking, high-income populations. Independent of zoning characteristics, greater numbers of outlets appeared in areas with greater market potentials and the immediately surrounding areas. Greater income excluded outlets in local and surrounding areas. Conclusions: These findings are consistent with the hypothesis that alcohol outlets are located in areas with high demand and are excluded from high-income areas. These processes appear to take place at relatively small geographic scales, encourage the concentration of outlets in specific low-income areas, and represent a very general economic process likely to take place in communities throughout the world. PMID:25978830

  10. PIV measurement at the blowdown pipe outlet

    International Nuclear Information System (INIS)

    Puustinen, M.; Laine, J.; Raesaenen, A.; Pyy, L.; Telkkae, J.

    2013-04-01

    This report summarizes the findings of the PIV measurement tests carried out in January - February 2013 with the scaled down PPOOLEX test facility at LUT. The main objective of the tests was to find out the operational limits of the PIV system regarding suitable test conditions and correct values of different adjustable PIV parameters. An additional objective was to gather CFD grade data for verification/validation of numerical models. Both water and steam injection tests were carried out. PIV measurements with cold water injection succeeded well. Raw images were of high quality, averaging over the whole measurement period could be done and flow fields close to the blowdown pipe outlet could be determined. In the warm water injection cases the obtained averaged velocity field images were harder to interpret, especially if the blowdown pipe was also filled with warm water in the beginning of the measurement period. The absolute values of the velocity vectors seemed to be smaller than in the cold water injection cases. With very small steam flow rates the steam/water interface was inside the blowdown pipe and quite stable in nature. The raw images were of good quality but due to some fluctuation in the velocity field averaging of the velocity images over the whole measured period couldn't be done. Condensation of steam in the vicinity of the pipe exit probably caused these fluctuations. A constant outflow was usually followed by a constant inflow towards the pipe exit. Vector field images corresponding to a certain phase of the test could be extracted and averaged but this would require a very careful analysis so that the images could be correctly categorized. With higher steam flow rates rapid condensation of large steam bubbles created small gas bubbles which were in front of the measurement area of the PIV system. They disturbed the measurements by reflecting laser light like seeding particles and therefore the raw images were of poor quality and they couldn't be

  11. Alcohol outlets, social disorganization, and robberies: accounting for neighborhood characteristics and alcohol outlet types.

    Science.gov (United States)

    Snowden, Aleksandra J; Freiburger, Tina L

    2015-05-01

    We estimated spatially lagged regression and spatial regime models to determine if the variation in total, on-premise, and off-premise alcohol outlet(1) density is related to robbery density, while controlling for direct and moderating effects of social disorganization.(2) Results suggest that the relationship between alcohol outlet density and robbery density is sensitive to the measurement of social disorganization levels. Total alcohol outlet density and off-premise alcohol outlet density were significantly associated with robbery density when social disorganization variables were included separately in the models. However, when social disorganization levels were captured as a four item index, only the association between off-premise alcohol outlets and robbery density remained significant. More work is warranted in identifying the role of off-premise alcohol outlets and their characteristics in robbery incidents. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. MRI of thoracic outlet syndrome in children

    Energy Technology Data Exchange (ETDEWEB)

    Chavhan, Govind B.; Batmanabane, Vaishnavi [The Hospital for Sick Children and University of Toronto, Department of Diagnostic Imaging, Toronto, ON (Canada); Muthusami, Prakash [The Hospital for Sick Children and University of Toronto, Department of Diagnostic Imaging, Toronto, ON (Canada); The Hospital for Sick Children, Division of Image Guided Therapy, Department of Diagnostic Imaging, Toronto, ON (Canada); Towbin, Alexander J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology and Medical Imaging, Cincinnati, OH (United States); Borschel, Gregory H. [The Hospital for Sick Children and University of Toronto, Division of Plastic Surgery, Department of Pediatric Surgery, Toronto, ON (Canada)

    2017-09-15

    Thoracic outlet syndrome is caused by compression of the neurovascular bundle as it passes from the upper thorax to the axilla. The neurovascular bundle can be compressed by bony structures such as the first rib, cervical ribs or bone tubercles, or from soft-tissue abnormalities like a fibrous band, muscle hypertrophy or space-occupying lesion. Thoracic outlet syndrome commonly affects young adults but can be seen in the pediatric age group, especially in older children. Diagnosis is based on a holistic approach encompassing clinical features, physical examination findings including those triggered by various maneuvers, electromyography, nerve conduction studies and imaging. Imaging is performed to confirm the diagnosis, exclude mimics and classify thoracic outlet syndrome into neurogenic, arterial, venous or mixed causes. MRI and MR angiography are useful in this process. A complete MRI examination for suspected thoracic outlet syndrome should include the assessment of anatomy and any abnormalities using routine sequences, vessel assessment with the arms in adduction by MR angiography and assessment of dynamic compression of vessels with abduction of the arms. The purpose of this paper is to describe the anatomy of the thoracic outlet, causes of thoracic outlet syndrome, the MR imaging techniques used in its diagnosis and the principles of image interpretation. (orig.)

  13. MRI of thoracic outlet syndrome in children

    International Nuclear Information System (INIS)

    Chavhan, Govind B.; Batmanabane, Vaishnavi; Muthusami, Prakash; Towbin, Alexander J.; Borschel, Gregory H.

    2017-01-01

    Thoracic outlet syndrome is caused by compression of the neurovascular bundle as it passes from the upper thorax to the axilla. The neurovascular bundle can be compressed by bony structures such as the first rib, cervical ribs or bone tubercles, or from soft-tissue abnormalities like a fibrous band, muscle hypertrophy or space-occupying lesion. Thoracic outlet syndrome commonly affects young adults but can be seen in the pediatric age group, especially in older children. Diagnosis is based on a holistic approach encompassing clinical features, physical examination findings including those triggered by various maneuvers, electromyography, nerve conduction studies and imaging. Imaging is performed to confirm the diagnosis, exclude mimics and classify thoracic outlet syndrome into neurogenic, arterial, venous or mixed causes. MRI and MR angiography are useful in this process. A complete MRI examination for suspected thoracic outlet syndrome should include the assessment of anatomy and any abnormalities using routine sequences, vessel assessment with the arms in adduction by MR angiography and assessment of dynamic compression of vessels with abduction of the arms. The purpose of this paper is to describe the anatomy of the thoracic outlet, causes of thoracic outlet syndrome, the MR imaging techniques used in its diagnosis and the principles of image interpretation. (orig.)

  14. High-resolution gulf water skin temperature estimation using TIR/ASTER

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; ManiMurali, R.; Mahender, K.

    to separate geomorphic features. It is demonstrated that high resolution water skin temperature of small water bodies can be determined correctly, economically and less laboriously using space-based TIR/ASTER and that estimated temperature can be effectively...

  15. THE INFLUENCE OF MONK EQUIPPED PONDS ON THE QUALITY OF BASIN HEAD STREAMS, THE EXAMPLE OF WATER TEMPERATURE IN LIMOUSIN AND BERRY (FRANCE

    Directory of Open Access Journals (Sweden)

    Laurent TOUCHART

    2010-12-01

    Full Text Available In the centre-west regions of France, the deep water outlet system known as a “monk” is used in 13% of bodies of water. The authorities are strongly encouraging this to increase, arguing that this system would reduce pond induced warming of the hydrographical network. We have measured the water temperature in four monk equipped ponds for 13 years to such an extent that this paper draws on an analysis of 142,200 original measurements. Compared to a surface outflow, a monk is a system which shifts the warming of the emissary water course to the end of summer and the autumn which reduces average annual warming by about 1°C. This reduces the heating of diurnal maxima but increases warming of the minima. A monk equipped pond warms the river with deep water which has acquired its heat by mechanical convection generated by the wind, as opposed to a weir equipped pond which provides surface water warmed by insolation. In winter the monk equipped pond does not damage the thermal living conditions for Fario trout embryos and larvae under the gravel. In summer, the monk prevents night time cooling of the emissary and increases the temperature of the minima excessively for sensitive species.

  16. Flow visualization study of two-phase flow in a single bend outlet feeder pipe of a CANDU reactor

    International Nuclear Information System (INIS)

    Savalaxs, S.-A.; Lister, D.H.; Steward, F.R.

    2005-01-01

    In CANDU reactors, the feeder piping that is used to direct the high-temperature water coolant between the fuel channels and the steam generators is made of carbon steel. Since 1996, several CANDU stations have reported excessive corrosion of their outlet feeders. The first metre is particularity vulnerable because the piping there consists of single or double bends, which have relatively thin walls produced by the bending process. Early studies related the attack to the hydrodynamics of the coolant and verified that it was a type of flow-accelerated corrosion. In order to understand the hydrodynamics of the coolant in the outlet feeders by flow visualization, a full-scale transparent test section simulating the geometry and orientation of an outlet feeder bend with its upstream components was fabricated. The feeder consisted of a 54 mm diameter acrylic pipe with a 73 degree bend. This was connected to the upstream component with an acrylic simulation of a Grayloc flanged fitting. A test loop supplied room temperature water to the test section at flow rates up to 0.019 m3/s. Air could be injected into the water to give a mean volume fraction of up to 0.56. In this preliminary investigation, the size and velocity of air bubbles at different flow conditions and their distribution within the pipe bend were studied. Particular attention was paid to the flow pattern at the inside of the bend, where a CFD (computational fluid dynamics) code - Fluent 6.1-had failed to predict a liquid film in an earlier study. A high-speed digital video camera was used to determine the relation between bubble size and velocity. Such a relation should help to explain the discrepancy in the CFD modelling and provide the basis for accurate predictions of phase distribution in complex geometries at high flow rates. (authors)

  17. Development of an Accelerated Methodology to Study Degradation of Materials in Supercritical Water for Application in High Temperature Power Plants

    Science.gov (United States)

    Rodriguez, David

    The decreasing supply of fossil fuel sources, coupled with the increasing concentration of green house gases has placed enormous pressure to maximize the efficiency of power generation. Increasing the outlet temperature of these power plants will result in an increase in operating efficiency. By employing supercritical water as the coolant in thermal power plants (nuclear reactors and coal power plants), the plant efficiency can be increased to 50%, compared to traditional reactors which currently operate at 33%. The goal of this dissertation is to establish techniques to characterize the mechanical properties and corrosion behavior of materials exposed to supercritical water. Traditionally, these tests have been long term exposure tests spanning months. The specific goal of this dissertation is to develop a methodology for accelerated estimation of corrosion rates in supercritical water that can be sued as a screening tool to select materials for long term testing. In this study, traditional methods were used to understand the degradation of materials in supercritical water and establish a point of comparison to the first electrochemical studies performed in supercritical water. Materials studied included austenitic steels (stainless steel 304, stainless steel 316 and Nitronic 50) and nickel based alloys (Inconel 625 and 718). Surface chemistry of the oxide layer was characterized using scanning electron microscopy, X-ray diffraction, FT-IR, Raman and X-ray photoelectron spectroscopies. Stainless steel 304 was subjected to constant tensile load creep tests in water at a pressure of 27 MPa and at temperatures of 200 °C, 315 °C and supercritical water at 450 °C for 24 hours. It was determined that the creep rate for stainless steel 304 exposed to supercritical water would be unacceptable for use in service. It was observed that the formation of hematite was favored in subcritical temperatures, while magnetite was formed in the supercritical region. Corrosion of

  18. Effect of water electrolysis temperature of hydrogen production system using direct coupling photovoltaic and water electrolyzer

    Directory of Open Access Journals (Sweden)

    Tetsuhiko Maeda

    2016-01-01

    Full Text Available We propose control methods of a photovoltaic (PV-water electrolyzer (ELY system that generates hydrogen by controlling the number of ELY cells. The advantage of this direct coupling between PV and ELY is that the power loss of DC/DC converter is avoided. In this study, a total of 15 ELY cells are used. In the previous researches, the electrolyzer temperature was constantly controlled with a thermostat. Actually, the electrolyzer temperature is decided by the balance of the electrolysis loss and the heat loss to the outside. Here, the method to control the number of ELY cells was investigated. Maximum Power Point Tracking efficiency of more than 96% was achieved without ELY temperature control. Furthermore we construct a numerical model taking into account of ELY temperature. Using this model, we performed a numerical simulation of 1-year. Experimental data and the simulation results shows the validity of the proposed control method.

  19. Coolant mixing in LMFBR rod bundles and outlet plenum mixing transients. Final report

    International Nuclear Information System (INIS)

    Todreas, N.E.; Cheng, S.K.; Basehore, K.

    1984-08-01

    This project principally undertook the investigation of the thermal hydraulic performance of wire wrapped fuel bundles of LMFBR configuration. Results obtained included phenomenological models for friction factors, flow split and mixing characteristics; correlations for predicting these characteristics suitable for insertion in design codes; numerical codes for analyzing bundle behavior both of the lumped subchannel and distributed parameter categories and experimental techniques for pressure velocity, flow split, salt conductivity and temperature measurement in water cooled mockups of bundles and subchannels. Flow regimes investigated included laminar, transition and turbulent flow under forced convection and mixed convection conditions. Forced convections conditions were emphasized. Continuing efforts are underway at MIT to complete the investigation of the mixed convection regime initiated here. A number of investigations on outlet plenum behavior were also made. The reports of these investigations are identified

  20. A survey of reference electrodes for high temperature waters

    International Nuclear Information System (INIS)

    Molander, A.; Eriksson, Sture; Pein, K.

    2000-11-01

    In nuclear power plants, corrosion potential measurements are used to follow the conditions for different corrosion types in reactor systems, particularly IGSCC in BWRs. The goal of this work has been to give a survey of reference electrodes for high temperature water, both those that are used for nuclear environments and those that are judged to possible future development. The reference electrodes that are used today in nuclear power plants for corrosion potential measurements are of three types. Silver chloride electrodes, membrane electrodes and platinum electrodes (hydrogen electrodes). The principals for their function is described as well as the conversion of measured potentials to the SHE scale (Standard Hydrogen Electrode). Silver chloride electrodes consist of an inner reference system of silver chloride in equilibrium with a chloride solution. The silver chloride electrode is the most common reference electrode and can be used in several different systems. Platinum electrodes are usually more robust and are particularly suitable to use in BWR environment to follow the hydrogen dosage, but have limitations at low and no hydrogen dosage. Ceramic membrane electrodes can be with different types of internal reference system. They were originally developed for pH measurements in high temperature water. If pH is constant, the membrane electrode can be used as reference electrode. A survey of ceramic reference electrodes for high temperature water is given. A ceramic membrane of the type used works as an oxygen conductor, so the potential and pH in surrounding medium is in equilibrium with the internal reference system. A survey of the lately development of electrodes is presented in order to explain why the different types of electrodes are developed as well as to give a background to the possibilities and limitations with the different electrodes. Possibilities of future development of electrodes are also given. For measurements at low or no hydrogen dosage

  1. 14 CFR 23.977 - Fuel tank outlet.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank outlet. 23.977 Section 23.977... tank outlet. (a) There must be a fuel strainer for the fuel tank outlet or for the booster pump. This... damage any fuel system component. (b) The clear area of each fuel tank outlet strainer must be at least...

  2. Water geochemistry to estimate reservoir temperature of Stabio springs, Switzerland

    Science.gov (United States)

    Pera, Sebastian; Soma, Linda

    2017-04-01

    The Mendrisiotto region located in Southern Switzerland and close to the Italian border, is characterized by the presence of a thick sequence of Mesozoic limestones and dolostones above a volcanic rocks from Permian (Bernoulli, 1964). Within the carbonates, fractures and dissolution processes increased limestone permeability and favored the widespread presence of springs. The presence of few localized H2S and CH4 bearing springs is known from historical times in Stabio. Its localization is related to the faulting affecting the area (Balderer et Al., 2007). These waters were classified by Greber et Al. (1997) as Na-(Ca)-(Mg)-HCO3-Cl-(SO4) type with having a total dissolved solid content in the range of 0.8 and 1.2 gl-1. According with Balderer et Al. (2007) the stable isotopic composition deviates from the global meteoric water line (IAEA, 1984) being the values of δ18O and δ2H respectively 0.8 ‰ and 5‰ lower than the normal shallow groundwater of the area. The values of δ13C of TDIC (-1.54‰ 1.44 ) indicate exchange with CO2 of thermo - metamorphic or even Mantle origin. While 14C in TDIC (7.95, 26.0 pMC) and 3H (1.1 ±0.7, 3.1±0.7 TU) indicates uprising of deep water along faults with some mixing. To estimate reservoir temperature, a new sampling was conducted in 2015 for chemical and isotopic analysis. The sampling was carried out from the only source that allows getting water directly from the dolostone in order to avoid mixing. Although some differences are noticed respect to previous studies, the results show a substantial agreement for stable isotopic composition of water, δ13C and 14C of TDIC. Reservoir temperature was calculated by using several geothermometers. The results show a great variability ranging from 60 ˚ C using Silica to more than 500 ˚ C using cationic ( Na - Ca) geothermometers; indicating that besides mixing, exchange processes and chemical reactions along flow path affect results. This study was partially funded by Azienda

  3. Sensitivity of Sump Water Temperature to Containment Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Misuk; Kim, Seoung Rae [Nuclear Engineering Service and Solution, Daejeon (Korea, Republic of)

    2014-05-15

    This paper is focused on the containment behavior analysis in the above described cases using GOTHIC-IST (generation of thermal-hydraulic information for containments, industry standard toolset). GOTHIC-IST version 7.2a is an integrated, general purpose thermal-hydraulics software package for design, licensing, safety and operating analysis of nuclear power plant containments and other confinement buildings. In this study, we perform the sensitivity the sump water temperature to containment integrity. For 35% RIH break accident with the malfunction of spray system, local air coolers, ECC(emergency core cooling) pump and heat exchanger, the peak pressure at boiler room do not exceed the design pressure 124kPa(g) of the containment and containment integrity is secured. If accompanied the malfunction of heat exchanger or pump in the time of low pressure safety injection, of ECCS, it will be one of the aggravating factors to the integrity of core and containment.

  4. Electrochemical corrosion potential and noise measurement in high temperature water

    International Nuclear Information System (INIS)

    Fong, Clinton; Chen, Yaw-Ming; Chu, Fang; Huang, Chia-Shen

    2000-01-01

    Hydrogen water chemistry (HWC) is one of the most important methods in boiling water reactor(BWR) system to mitigate and prevent stress corrosion cracking (SCC) problems of stainless steel components. Currently, the effectiveness of HWC in each BWR is mainly evaluated by the measurement of electrochemical corrosion potentials (ECP) and on-line monitoring of SCC behaviors of stainless steels. The objective of this work was to evaluate the characteristics and performance of commercially available high temperature reference electrodes. In addition, SCC monitoring technique based on electrochemical noise analysis (ECN) was also tested to examine its crack detection capability. The experimental work on electrochemical corrosion potential (ECP) measurements reveals that high temperature external Ag/AgCl reference electrode of highly dilute KCl electrolyte can adequately function in both NWC and HWC environments. The high dilution external Ag/AgCl electrode can work in conjunction with internal Ag/AgCl reference electrode, and Pt electrode to ensure the ECP measurement reliability. In simulated BWR environment, the electrochemical noise tests of SCC were carried out with both actively and passively loaded specimens of type 304 stainless steel with various electrode arrangements. From the coupling current and corrosion potential behaviors of the passive loading tests during immersion test, it is difficult to interpret the general state of stress corrosion cracking based on the analytical results of overall current and potential variations, local pulse patterns, statistical characteristics, or power spectral density of electrochemical noise signals. However, more positive SCC indication was observed in the power spectral density analysis. For aqueous environments of high solution impedance, successful application of electrochemical noise technique for SCC monitoring may require further improvement in specimen designs and analytical methods to enhance detection sensitivity

  5. Effect of drinking water temperature on water intake and performance of dairy calves.

    Science.gov (United States)

    Huuskonen, A; Tuomisto, L; Kauppinen, R

    2011-05-01

    Very limited information is available on the effects of drinking water temperature on dairy calves. Therefore, the present experiment was designed to study the effects on performance, health, and water consumption of dairy calves offered drinking water either warm (16 to 18 °C) or cold (6 to 8 °C). The calves (60 calves/treatment) were housed in an insulated barn in pens (3.0 × 3.5m; 5 calves in each) providing 2.1m(2)/calf. During the experimental period (20 to 195 d of age), the calves had free access to water from an open water bowl (depth 80 mm, diameter 220 mm, 2-L capacity, 1 bowl/pen). During the preweaning period (20 to 75 d of age), all calves received milk replacer (7.5L/calf daily) and had free access to commercial starter, grass silage, and hay. During the postweaning period (75 to 195 d), the weaned calves had free access to grass silage and hay and were given 3 kg/d (air-dry basis) of a commercial concentrate mixture. During the preweaning period, the water intake of the calves offered warm water was 47% higher than that of the calves offered cold water. Water intake in both treatments increased rapidly during weaning and for a few days following weaning. At 180 to 195 d of age, the calves consumed approximately 18 to 20 L of water daily. Calves offered warm water drank 7 and 8% more water during the postweaning period and overall during the experimental period, respectively, compared with those offered cold water. No treatment differences were observed in dry matter or energy intakes, body weight gains, or feed conversion rates. Furthermore, total serum IgG concentrations of the calves did not differ during the preweaning or postweaning periods. Dairy calves consumed more warm than cold water, but the increase in water intake did not influence feed intake, body weight gain, or health parameters. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. Design of Water Temperature Control System Based on Single Chip Microcomputer

    Science.gov (United States)

    Tan, Hanhong; Yan, Qiyan

    2017-12-01

    In this paper, we mainly introduce a multi-function water temperature controller designed with 51 single-chip microcomputer. This controller has automatic and manual water, set the water temperature, real-time display of water and temperature and alarm function, and has a simple structure, high reliability, low cost. The current water temperature controller on the market basically use bimetal temperature control, temperature control accuracy is low, poor reliability, a single function. With the development of microelectronics technology, monolithic microprocessor function is increasing, the price is low, in all aspects of widely used. In the water temperature controller in the application of single-chip, with a simple design, high reliability, easy to expand the advantages of the function. Is based on the appeal background, so this paper focuses on the temperature controller in the intelligent control of the discussion.

  7. Water temperature forecasting and estimation using fourier series and communication theory techniques

    International Nuclear Information System (INIS)

    Long, L.L.

    1976-01-01

    Fourier series and statistical communication theory techniques are utilized in the estimation of river water temperature increases caused by external thermal inputs. An example estimate assuming a constant thermal input is demonstrated. A regression fit of the Fourier series approximation of temperature is then used to forecast daily average water temperatures. Also, a 60-day prediction of daily average water temperature is made with the aid of the Fourier regression fit by using significant Fourier components

  8. Solar High Temperature Water-Splitting Cycle with Quantum Boost

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Robin [SAIC; Davenport, Roger [SAIC; Talbot, Jan [UCSD; Herz, Richard [UCSD; Genders, David [Electrosynthesis Co.; Symons, Peter [Electrosynthesis Co.; Brown, Lloyd [TChemE

    2014-04-25

    A sulfur family chemical cycle having ammonia as the working fluid and reagent was developed as a cost-effective and efficient hydrogen production technology based on a solar thermochemical water-splitting cycle. The sulfur ammonia (SA) cycle is a renewable and sustainable process that is unique in that it is an all-fluid cycle (i.e., with no solids handling). It uses a moderate temperature solar plant with the solar receiver operating at 800°C. All electricity needed is generated internally from recovered heat. The plant would operate continuously with low cost storage and it is a good potential solar thermochemical hydrogen production cycle for reaching the DOE cost goals. Two approaches were considered for the hydrogen production step of the SA cycle: (1) photocatalytic, and (2) electrolytic oxidation of ammonium sulfite to ammonium sulfate in aqueous solutions. Also, two sub-cycles were evaluated for the oxygen evolution side of the SA cycle: (1) zinc sulfate/zinc oxide, and (2) potassium sulfate/potassium pyrosulfate. The laboratory testing and optimization of all the process steps for each version of the SA cycle were proven in the laboratory or have been fully demonstrated by others, but further optimization is still possible and needed. The solar configuration evolved to a 50 MW(thermal) central receiver system with a North heliostat field, a cavity receiver, and NaCl molten salt storage to allow continuous operation. The H2A economic model was used to optimize and trade-off SA cycle configurations. Parametric studies of chemical plant performance have indicated process efficiencies of ~20%. Although the current process efficiency is technically acceptable, an increased efficiency is needed if the DOE cost targets are to be reached. There are two interrelated areas in which there is the potential for significant efficiency improvements: electrolysis cell voltage and excessive water vaporization. Methods to significantly reduce water evaporation are

  9. Modeling Air Temperature/Water Temperature Relations Along a Small Mountain Stream Under Increasing Urban Influence

    Science.gov (United States)

    Fedders, E. R.; Anderson, W. P., Jr.; Hengst, A. M.; Gu, C.

    2017-12-01

    greater. This indicates a possible tipping point in the stream temperature-water temperature relationship at which increased urbanization overpowers increasing stream thermal inertia.

  10. Discharge, water temperature, and water quality of Warm Mineral Springs, Sarasota County, Florida: A retrospective analysis

    Science.gov (United States)

    Metz, Patricia A.

    2016-09-27

    in inland areas, and upward flow toward the surface in coastal areas, such as at Warm Mineral Springs. Warm Mineral Springs is located in a discharge area. Changes in water use in the region have affected the potentiometric surface of the Upper Floridan aquifer. Historical increase in groundwater withdrawals resulted in a 10- to 20-foot regional decline in the potentiometric surface of the Upper Floridan aquifer by May 1975 relative to predevelopment levels and remained at approximately that level in May 2007 in the area of Warm Mineral Springs. Discharge measurements at Warm Mineral Springs (1942–2014) decreased from about 11–12 cubic feet per second in the 1940s to about 6–9 cubic feet per second in the 1970s and remained at about that level for the remainder of the period of record. Similarity of changes in regional water use and discharge at Warm Mineral Springs indicates that basin-scale changes to the groundwater system have affected discharge at Warm Mineral Springs. Water temperature had no significant trend in temperature over the period of record, 1943–2015, and outliers were identified in the data that might indicate inconsistencies in measurement methods or locations.Within the regional groundwater basin, Warm Mineral Springs is influenced by deep Upper Floridan aquifer flow paths that discharge toward the coast. Associated with these flow paths, the groundwater temperatures increase with depth and toward the coast. Multiple lines of evidence indicate that a source of warm groundwater to Warm Mineral Springs is likely the permeable zone of the Avon Park Formation within the Upper Floridan aquifer at a depth of about 1,400 to 1,600 feet, or deeper sources. The permeable zone contains saline groundwater with water temperatures of at least 95 degrees Fahrenheit.The water quality of Warm Mineral Springs, when compared with other springs in Florida had the highest temperature and the greatest mineralized content. Warm Mineral Springs water is

  11. Incorporation of the equilibrium temperature approach in a Soil and Water Assessment Tool hydroclimatological stream temperature model

    Science.gov (United States)

    Du, Xinzhong; Shrestha, Narayan Kumar; Ficklin, Darren L.; Wang, Junye

    2018-04-01

    Stream temperature is an important indicator for biodiversity and sustainability in aquatic ecosystems. The stream temperature model currently in the Soil and Water Assessment Tool (SWAT) only considers the impact of air temperature on stream temperature, while the hydroclimatological stream temperature model developed within the SWAT model considers hydrology and the impact of air temperature in simulating the water-air heat transfer process. In this study, we modified the hydroclimatological model by including the equilibrium temperature approach to model heat transfer processes at the water-air interface, which reflects the influences of air temperature, solar radiation, wind speed and streamflow conditions on the heat transfer process. The thermal capacity of the streamflow is modeled by the variation of the stream water depth. An advantage of this equilibrium temperature model is the simple parameterization, with only two parameters added to model the heat transfer processes. The equilibrium temperature model proposed in this study is applied and tested in the Athabasca River basin (ARB) in Alberta, Canada. The model is calibrated and validated at five stations throughout different parts of the ARB, where close to monthly samplings of stream temperatures are available. The results indicate that the equilibrium temperature model proposed in this study provided better and more consistent performances for the different regions of the ARB with the values of the Nash-Sutcliffe Efficiency coefficient (NSE) greater than those of the original SWAT model and the hydroclimatological model. To test the model performance for different hydrological and environmental conditions, the equilibrium temperature model was also applied to the North Fork Tolt River Watershed in Washington, United States. The results indicate a reasonable simulation of stream temperature using the model proposed in this study, with minimum relative error values compared to the other two models

  12. Measurement of unsteady airflow velocity at nozzle outlet

    Science.gov (United States)

    Pyszko, René; Machů, Mário

    2017-09-01

    The paper deals with a method of measuring and evaluating the cooling air flow velocity at the outlet of the flat nozzle for cooling a rolled steel product. The selected properties of the Prandtl and Pitot sensing tubes were measured and compared. A Pitot tube was used for operational measurements of unsteady dynamic pressure of the air flowing from nozzles to abtain the flow velocity. The article also discusses the effects of air temperature, pressure and relative air humidity on air density, as well as the influence of dynamic pressure filtering on the error of averaged velocity.

  13. Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

    Science.gov (United States)

    Bąk, Joanna

    2018-02-01

    At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water - air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

  14. Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

    Directory of Open Access Journals (Sweden)

    Bąk Joanna

    2018-01-01

    Full Text Available At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water – air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

  15. Effect of inlet and outlet flow conditions on natural gas parameters in supersonic separation process.

    Directory of Open Access Journals (Sweden)

    Yan Yang

    Full Text Available A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions.

  16. Observations and model estimates of diurnal water temperature dynamics in mosquito breeding sites in western Kenya

    NARCIS (Netherlands)

    Paaijmans, K.P.; Jacobs, A.F.G.; Takken, W.; Heusinkveld, B.G.; Githeko, A.K.; Dicke, M.; Holtslag, A.A.M.

    2008-01-01

    Water temperature is an important determinant of the growth and development of malaria mosquito immatures. To gain a better understanding of the daily temperature dynamics of malaria mosquito breeding sites and of the relationships between meteorological variables and water temperature, three clear

  17. Coolant mixing in LMFBR rod bundles and outlet plenum mixing transients. Progress report, March 1, 1977--May 31, 1977

    International Nuclear Information System (INIS)

    Todreas, N.E.; Golay, M.W.; Wolf, L.

    1977-01-01

    Progress is summarized in the following tasks: (1) bundle flow studies (wrapped and bare rods); (2) subchannel flow studies (bare rods); (3) LMFBR outlet plenum flow mixing; and (4) theoretical determination of local temperature fields in LMFBR fuel rod bundles

  18. On the behavior of water at subfreezing temperatures in a protein crystal: evidence of higher mobility than in bulk water.

    Science.gov (United States)

    Wang, Dongqi; Böckmann, Anja; Dolenc, Jožica; Meier, Beat H; van Gunsteren, Wilfred F

    2013-10-03

    NMR experiments have shown that water molecules in the crystal of the protein Crh are still mobile at temperatures well below 273 K. In order to investigate this water anomaly, a molecular dynamics (MD) simulation study of crystalline Crh was carried out to determine the mobility of water in this crystal. The simulations were carried out at three temperatures, 150, 200, and 291 K. Simulations of bulk water at these temperatures were also done to obtain the properties of the simple point charge (SPC) water model used at these temperatures and to allow a comparison of the properties of water in the Crh crystal with those of bulk water at the same temperatures. According to the simulations, water is immobilized at 150 K both in crystal and in bulk water. As expected, at 291 K it diffuses and rotates more slowly in the protein crystal than in bulk water. However, at 200 K, the translational and rotational mobility of the water molecules is larger in the crystal than in bulk water. The enhancement of water mobility in the crystal at 200 K was further investigated by MD simulations in which the backbone or all protein atoms were positionally restrained, and in which additionally the electrostatic protein-water interactions were removed. Of these changes in the environment of the water molecules, rigidifying the protein backbones slightly enhanced water diffusion, while it slowed down rotation. In contrast, removal of electrostatic protein-water interactions did not change water diffusion but enhanced rotational motion significantly. Further investigations are required to delineate particular features of the protein crystal that induce the anomalous behavior of water at 200 K.

  19. Evaporation of nanoscale water on a uniformly complete wetting surface at different temperatures.

    Science.gov (United States)

    Guo, Yuwei; Wan, Rongzheng

    2018-05-03

    The evaporation of nanoscale water films on surfaces affects many processes in nature and industry. Using molecular dynamics (MD) simulations, we show the evaporation of a nanoscale water film on a uniformly complete wetting surface at different temperatures. With the increase in temperature, the growth of the water evaporation rate becomes slow. Analyses show that the hydrogen bond (H-bond) lifetimes and orientational autocorrelation times of the outermost water film decrease slowly with the increase in temperature. Compared to a thicker water film, the H-bond lifetimes and orientational autocorrelation times of a monolayer water film are much slower. This suggests that the lower evaporation rate of the monolayer water film on a uniformly complete wetting surface may be caused by the constriction of the water rotation due to the substrate. This finding may be helpful for controlling nanoscale water evaporation within a certain range of temperatures.

  20. Double-outlet right ventricle revisited.

    Science.gov (United States)

    Ebadi, Ameneh; Spicer, Diane E; Backer, Carl L; Fricker, F Jay; Anderson, Robert H

    2017-08-01

    Double-outlet right ventricle is a form of ventriculoarterial connection. The definition formulated by the International Society for Nomenclature of Paediatric and Congenital Heart Disease is based on hearts with both arterial trunks supported in their greater part by a morphologically right ventricle. Bilateral infundibula and ventricular septal defects are highly debated criteria. This study examines the anatomic controversies surrounding double-outlet right ventricle. We show that hearts with double-outlet right ventricle can have atrioventricular-to-arterial valvular continuity. We emphasize the difference between the interventricular communication and the zone of deficient ventricular septation. The hearts examined were from the University of Florida in Gainesville; Johns Hopkins All Children's Hospital, St Petersburg, Fla; and Lurie Children's Hospital, Chicago, Ill. Each specimen had at least 75% of both arterial roots supported by the morphologically right ventricle, with a total of 100 hearts examined. The morphologic method was used to assess anatomic features, including arterial-atrioventricular valvular continuity, subarterial infundibular musculature, and the location of the hole between the ventricles. Most hearts had fibrous continuity between one of the arterial valves and an atrioventricular valve, with bilateral infundibula in 23%, and intact ventricular septum in 5%. Bilateral infundibula are not a defining feature of double-outlet right ventricle, representing only 23% of the specimens in our sample. The interventricular communication can have a posteroinferior muscular rim or extend to become perimembranous (58%). Double-outlet right ventricle can exist with an intact ventricular septum. Copyright © 2017 The American Association for Thoracic Surgery. All rights reserved.

  1. Mapping spatial and temporal variation of stream water temperature in the upper Esopus Creek watershed

    Science.gov (United States)

    Chien, H.; McGlinn, L.

    2017-12-01

    The upper Esopus Creek and its tributary streams located in the Catskill Mountain region of New York State provide habitats for cold-adapted aquatic species. However, ongoing global warming may change the stream water temperature within a watershed and disturb the persistence of coldwater habitats. Characterizing thermal regimes within the upper Esopus Creek watershed is important to provide information of thermally suitable habitats for aquatic species. The objectives of this study are to measure stream water temperature and map thermal variability among tributaries to the Esopus Creek and within Esopus Creek. These objectives will be achieved by measuring stream water temperature for at least two years. More than 100 water temperature data loggers have been placed in the upper Esopus Creek and their tributaries to collect 30-minute interval water temperatures. With the measured water temperature, we will use spatial interpolation in ArcGIS to create weekly and monthly water temperature surface maps to evaluate the thermal variation over time and space within the upper Esopus Creek watershed. We will characterize responsiveness of water temperature in tributary streams to air temperature as well. This information of spatial and temporal variation of stream water temperature will assist stream managers with prioritizing management practices that maintain or enhance connectivity of thermally suitable habitats in high priority areas.

  2. Development of a solenoid actuated planar valveless micropump with single and multiple inlet-outlet arrangements

    Science.gov (United States)

    Kumar, N.; George, D.; Sajeesh, P.; Manivannan, P. V.; Sen, A. K.

    2016-07-01

    We report a planar solenoid actuated valveless micropump with multiple inlet-outlet configurations. The self-priming characteristics of the multiple inlet-multiple outlet micropump are studied. The filling dynamics of the micropump chamber during start-up and the effects of fluid viscosity, voltage and frequency on the dynamics are investigated. Numerical simulations for multiple inlet-multiple outlet micropumps are carried out using fluid structure algorithm. With DI water and at 5.0 Vp-p, 20 Hz frequency, the two inlet-two outlet micropump provides a maximum flow rate of 336 μl min-1 and maximum back pressure of 441 Pa. Performance characteristics of the two inlet-two outlet micropump are studied for aqueous fluids of different viscosity. Transport of biological cell lines and diluted blood samples are demonstrated; the flow rate-frequency characteristics are studied. Viability of cells during pumping with multiple inlet multiple outlet configuration is also studied in this work, which shows 100% of cells are viable. Application of the proposed micropump for simultaneous pumping, mixing and distribution of fluids is demonstrated. The proposed integrated, standalone and portable micropump is suitable for drug delivery, lab-on-chip and micro-total-analysis applications.

  3. Warmer temperatures reduce net carbon uptake, but not water use, in a mature southern Appalachian forest

    Science.gov (United States)

    Increasing air temperature is expected to extend growing season length in temperate, broadleaf forests, leading to potential increases in evapotranspiration and net carbon uptake. However, other key processes affecting water and carbon cycles are also highly temperature-dependent...

  4. Effect of water temperature on biofouling development in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia; Vrouwenvelder, Johannes S.; van Loosdrecht, Mark C.M.; Bucs, Szilard; Staal, Marc

    2016-01-01

    temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high

  5. Influence of water chemistry on IGSCC growth rate of SUS316 under high temperature water

    International Nuclear Information System (INIS)

    Fukumura, Takuya; Terachi, Takumi; Arioka, Koji

    2005-01-01

    The influence of the environment on intergranular stress corrosion crack behavior was examined by performing tensile tests in high-temperature water using cold-water non-sensitized 316 stainless steel. In the constant elongation test, the crack growth rate showed a clear environmental dependence on the concentration of dissolved hydrogen, boric acid and lithium, but no such environmental dependence was observed in the compact tension test. Regarding the influence of the environment on the intergranular stress corrosion crack behavior of non-sensitized 316 stainless steel, it is considered that the environmental factors of dissolved hydrogen (3-45 cc/kgH 2 O), boric acid (500-3500 ppm) and lithium (0.05-10 ppm) greatly affect the initiation process but do not significantly affect the propagation process. (author)

  6. Changes in Stream Water Temperatures in the Chesapeake Bay Region, 1960-2014

    Science.gov (United States)

    This map shows the changes in stream water temperatures in the Chesapeake Bay region from 1960 to 2014. Blue circles represent cooling trends in stream water temperatures, and red circles represent warming trends in stream water temperatures. Data were analyzed by Mike Kolian of EPA in partnership with John Jastram and Karen Rice of the U.S. Geological Survey. For more information: www.epa.gov/climatechange/science/indicators

  7. Temperature dependence of water-water and ion-water correlations in bulk water and electrolyte solutions probed by femtosecond elastic second harmonic scattering

    Science.gov (United States)

    Chen, Yixing; Dupertuis, Nathan; Okur, Halil I.; Roke, Sylvie

    2018-06-01

    The temperature dependence of the femtosecond elastic second harmonic scattering (fs-ESHS) response of bulk light and heavy water and their electrolyte solutions is presented. We observe clear temperature dependent changes in the hydrogen (H)-bond network of water that show a decrease in the orientational order of water with increasing temperature. Although D2O has a more structured H-bond network (giving rise to more fs-ESHS intensity), the relative temperature dependence is larger in H2O. The changes are interpreted in terms of the symmetry of H-bonds and are indicators of nuclear quantum effects. Increasing the temperature in electrolyte solutions decreases the influence of the total electrostatic field from ions on the water-water correlations, as expected from Debye-Hückel theory, since the Debye length becomes longer. The effects are, however, 1.9 times (6.3 times) larger than those predicted for H2O (D2O). Since fs-ESHS responses can be computed from known molecular coordinates, our observations provide a unique opportunity to refine quantum mechanical models of water.

  8. Thermal infrared remote sensing of water temperature in riverine landscapes: Chapter 5

    Science.gov (United States)

    Carbonneau, Rebecca N.; Piégay, Hervé; Handcock, R.N; Torgersen, Christian E.; Cherkauer, K.A; Gillespie, A.R; Tockner, K; Faux, R. N.; Tan, Jing

    2012-01-01

    Water temperature in riverine landscapes is an important regional indicator of water quality that is influenced by both ground- and surface-water inputs, and indirectly by land use in the surrounding watershed (Brown and Krygier, 1970; Beschta et al., 1987; Chen et al., 1998; Poole and Berman, 2001). Coldwater fishes such as salmon and trout are sensitive to elevated water temperature; therefore, water temperature must meet management guidelines and quality standards, which aim to create a healthy environment for endangered populations (McCullough et al., 2009). For example, in the USA, the Environmental Protection Agency (EPA) has established water quality standards to identify specific temperature criteria to protect coldwater fishes (Environmental Protection Agency, 2003). Trout and salmon can survive in cool-water refugia even when temperatures at other measurement locations are at or above the recommended maximums (Ebersole et al., 2001; Baird and Krueger, 2003; High et al., 2006). Spatially extensive measurements of water temperature are necessary to locate these refugia, to identify the location of ground- and surface-water inputs to the river channel, and to identify thermal pollution sources. Regional assessment of water temperature in streams and rivers has been limited by sparse sampling in both space and time. Water temperature has typically been measured using a network of widely distributed instream gages, which record the temporal change of the bulk, or kinetic, temperature of the water (Tk) at specific locations. For example, the State of Washington (USA) recorded water quality conditions at 76 stations within the Puget Lowlands eco region, which contains 12,721 km of streams and rivers (Washington Department of Ecology, 1998). Such gages are sparsely distributed, are typically located only in larger streams and rivers, and give limited information about the spatial distribution of water temperature (Cherkauer et al., 2005).

  9. A hierarchical bayesian model to quantify uncertainty of stream water temperature forecasts.

    Directory of Open Access Journals (Sweden)

    Guillaume Bal

    Full Text Available Providing generic and cost effective modelling approaches to reconstruct and forecast freshwater temperature using predictors as air temperature and water discharge is a prerequisite to understanding ecological processes underlying the impact of water temperature and of global warming on continental aquatic ecosystems. Using air temperature as a simple linear predictor of water temperature can lead to significant bias in forecasts as it does not disentangle seasonality and long term trends in the signal. Here, we develop an alternative approach based on hierarchical Bayesian statistical time series modelling of water temperature, air temperature and water discharge using seasonal sinusoidal periodic signals and time varying means and amplitudes. Fitting and forecasting performances of this approach are compared with that of simple linear regression between water and air temperatures using i an emotive simulated example, ii application to three French coastal streams with contrasting bio-geographical conditions and sizes. The time series modelling approach better fit data and does not exhibit forecasting bias in long term trends contrary to the linear regression. This new model also allows for more accurate forecasts of water temperature than linear regression together with a fair assessment of the uncertainty around forecasting. Warming of water temperature forecast by our hierarchical Bayesian model was slower and more uncertain than that expected with the classical regression approach. These new forecasts are in a form that is readily usable in further ecological analyses and will allow weighting of outcomes from different scenarios to manage climate change impacts on freshwater wildlife.

  10. Water infiltration in an aquifer recharge basin affected by temperature and air entrapment

    OpenAIRE

    Loizeau Sébastien; Rossier Yvan; Gaudet Jean-Paul; Refloch Aurore; Besnard Katia; Angulo-Jaramillo Rafael; Lassabatere Laurent

    2017-01-01

    Artificial basins are used to recharge groundwater and protect water pumping fields. In these basins, infiltration rates are monitored to detect any decrease in water infiltration in relation with clogging. However, miss-estimations of infiltration rate may result from neglecting the effects of water temperature change and air-entrapment. This study aims to investigate the effect of temperature and air entrapment on water infiltration at the basin scale by conducting successive infiltration c...

  11. Heat transfer from the evaporator outlet to the charge of thermostatic expansion valves

    DEFF Research Database (Denmark)

    Langmaack, Lasse Nicolai; Knudsen, Hans-Jørgen Høgaard

    2006-01-01

    outlet with a special mounting strap. The heat transfer is quite complex because it takes place both directly through the contact points between bulb and pipe and indirectly through the mounting strap The TXV has to react to temperature changes at the evaporator outlet. Therefore, the dynamic behavior...... of the valve (and thereby the whole refrigeration system) depends greatly on the heat transfer between the evaporator outlet tube and the charge in the bulb. In this paper a model for the overall heat transfer between the pipe and the charge is presented. Geometrical data and material properties have been kept...... been found to predict the time constant for the temperature development in the bulb within 1-10 %. Furthermore it has been found that app. 20% of the heat transfer takes place trough the mounting strap....

  12. The annual number of days that solar heated water satisfies a specified demand temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yohanis, Y.G. [Thermal Systems Engineering Group, Faculty of Engineering, University of Ulster, BT37 0QB Northern Ireland (United Kingdom); Popel, O.; Frid, S.E. [Non-traditional Renewable Energy Sources, Institute for High Temperatures, Russian Academy of Sciences, 13/19 Izhorskaya str., IVTAN, Moscow 127412 (Russian Federation); Norton, B. [Dublin Institute of Technology, Aungier Street, Dublin 2 (Ireland)

    2006-08-15

    An analysis of solar water heating systems determines the number of days in each month when solar heated water wholly meets demand above a set temperature. The approach has been used to investigate the potential contribution to water heating loads of solar water heating in two UK locations. Correlations between the approach developed and the use of solar fractions are discussed. (author)

  13. Simulation of climate-change effects on streamflow, lake water budgets, and stream temperature using GSFLOW and SNTEMP, Trout Lake Watershed, Wisconsin

    Science.gov (United States)

    Hunt, Randall J.; Walker, John F.; Selbig, William R.; Westenbroek, Stephen M.; Regan, R. Steve

    2013-01-01

    2010–2100 showed increases in maximum and minimum temperature over the scenario period. Scenarios of future precipitation did not show a monotonic trend like temperature. Uncertainty in the climate drivers increased over time for both temperature and precipitation. Separate calibration of the uncoupled groundwater and surface-water models did not provide a representative initial parameter set for coupled model calibration. A sequentially linked calibration, in which the uncoupled models were linked by means of utility software, provided a starting parameter set suitable for coupled model calibration. Even with sequentially linked calibration, however, transmissivity of the lower part of the aquifer required further adjustment during coupled model calibration to attain reasonable parameter values for evaporation rates off a small seepage lake (a lake with no appreciable surface-water outlets) with a long history of study. The resulting coupled model was well calibrated to most types of observed time-series data used for calibration. Daily stream temperatures measured during 2002 were successfully simulated with SNTEMP; the model fit was acceptable for a range of groundwater inflow rates into the streams. Forecasts of potential climate change scenarios showed growing season length increasing by weeks, and both potential and actual evapotranspiration rates increasing appreciably, in response to increasing air temperature. Simulated actual evapotranspiration rates increased less than simulated potential evapotranspiration rates as a result of water limitation in the root zone during the summer high-evapotranspiration period. The hydrologic-system response to climate change was characterized by a reduction in the importance of the snow-melt pulse and an increase in the importance of fall and winter groundwater recharge. The less dynamic hydrologic regime is likely to result in drier soil conditions in rainfed wetlands and uplands, in contrast to less drying in groundwater

  14. 49 CFR 178.345-11 - Tank outlets.

    Science.gov (United States)

    2010-10-01

    ... unloading of lading, as distinguished from outlets such as manhole covers, vents, vapor recovery devices... away from the loading/unloading outlet. The actuating mechanism must be corrosion-resistant and...

  15. Hydrologic Outlets of the Greenland Ice Sheet, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Hydrologic Outlets of the Greenland Ice Sheet data set contains GIS point shapefiles that include 891 observed and potential hydrologic outlets of the Greenland...

  16. Study on extreme high temperature of cooling water in Chinese coastal nuclear power plant

    International Nuclear Information System (INIS)

    Yu Fan; Jiang Ziying

    2012-01-01

    In order to protect aquatic life from the harmful effects of thermal discharge, the appropriate water temperature limits or the scope of the mixing zone is a key issue in the regulatory control of the environmental impact of thermal discharge. Based on the sea surface temperature in the Chinese coastal waters, the extreme value of the seawater temperature change was analyzed by using the Gumbel model. The limit of the design temperature rise of cooling water in the outfall is 9 ℃, and the limit of the temperature rise of cooling water in the edge of the mixing zone is 4 ℃. The extreme high temperature of the cooling water in Chinese coastal nuclear power plant is 37 ℃ in the Bohai Sea, Yellow Sea, and is 40 ℃ in East China Sea, South China Sea. (authors)

  17. A novel nuclear combined power and cooling system integrating high temperature gas-cooled reactor with ammonia–water cycle

    International Nuclear Information System (INIS)

    Luo, Chending; Zhao, Fuqiang; Zhang, Na

    2014-01-01

    Highlights: • We propose a novel nuclear ammonia–water power and cooling cogeneration system. • The high temperature reactor is inherently safe, with exhaust heat fully recovered. • The thermal performances are improved compared with nuclear combined cycle. • The base case attains an energy efficiency of 69.9% and exergy efficiency of 72.5%. • Energy conservation and emission reduction are achieved in this cogeneration way. - Abstract: A nuclear ammonia–water power and refrigeration cogeneration system (NAPR) has been proposed and analyzed in this paper. It consists of a closed high temperature gas-cooled reactor (HTGR) topping Brayton cycle and a modified ammonia water power/refrigeration combined bottoming cycle (APR). The HTGR is an inherently safe reactor, and thus could be stable, flexible and suitable for various energy supply situation, and its exhaust heat is fully recovered by the mixture of ammonia and water in the bottoming cycle. To reduce exergy losses and enhance outputs, the ammonia concentrations of the bottoming cycle working fluid are optimized in both power and refrigeration processes. With the HTGR of 200 MW thermal capacity and 900 °C/70 bar reactor-core-outlet helium, the system achieves 88.8 MW net electrical output and 9.27 MW refrigeration capacity, and also attains an energy efficiency of 69.9% and exergy efficiency of 72.5%, which are higher by 5.3%-points and 2.6%-points as compared with the nuclear combined cycle (NCC, like a conventional gas/steam power-only combined cycle while the topping cycle is a closed HTGR Brayton cycle) with the same nuclear energy input. Compared with conventional separate power and refrigeration generation systems, the fossil fuel saving (based on CH 4 ) and CO 2 emission reduction of base-case NAPR could reach ∼9.66 × 10 4 t/y and ∼26.6 × 10 4 t/y, respectively. The system integration accomplishes the safe and high-efficiency utilization of nuclear energy by power and refrigeration

  18. Zinc sacrificial anode behavior at elevated temperatures in sodium chloride and tap water environments

    International Nuclear Information System (INIS)

    Othman, Othman Mohsen

    2005-01-01

    Zinc sacrificial anode coupled to mild steel was tested in sodium chloride and tap water environments at elevated temperatures. The anode failed to protect the mild steel specimens in tap water environment at all temperatures specified for this study. This was partly due to the high resistivity of the medium. The temperature factor did not help to activate the anode in water tap medium. In sodium chloride environment the anode demonstrated good protection for steel cathodes. In tap water environment the anode weight loss was negligible. The zinc anode suffered intergranular corrosion in sodium chloride environment and this was noticed starting at 40 degree centigrade. In tap water environment the zinc anode demonstrated interesting behavior beyond 60 degree centigrade, that could be attributed to the phenomenon of reversal of potential at elevated temperatures. It also showed shallow pitting spots in tap water environment without any sign of intergranular corrosion. Zinc anodes would suffer intergranular corrosion at high temperatures. (author)

  19. Power source with spark-safe outlet

    Energy Technology Data Exchange (ETDEWEB)

    Tsesarenko, N P; Alekhin, A V

    1982-01-01

    The invention refers to the technique of electrical monitoring and control in systems operating in a spark-safe medium (for example, in coal mines). A more accurate area of application is mobile objects with autonomous source of electricity (mine diesel locomotives, battery electric locomotives etc.). The purpose of the invention is to simplify and to improve the reliability of the planned device, and also to expand the area of application for conditions when it is powered from an autonomous generator of direct voltage. This goal is achieved because the power source with spark-safe outlet (the source contains a thyristor of advance disconnection, connected by anode to the delimiting throttle, one outlet of which is connected to the capacitor included between the controlling electrode and the anode of the thyristor, and the capacitor is connected through the resistor parallel to the outlet clamps of the source, while the thyristor of emergency protection connected parallel to the inlet clamps of the power source) is additionally equipped with a current sensor, hercon, transistor key (included in series in the power circuit) and optron, whose emitter is connected parallel to the current sensor connected in series to the inlet of the power source, while the receiver of the optron is connected in a circuit for controlling the thyristor of emergency protection. Hercon is built into the core of the delimiting throttle and is connected to the circuit for controlling the transistor key.

  20. Net carbon allocation in soybean seedlings as influenced by soil water stress at two soil temperatures

    International Nuclear Information System (INIS)

    McCoy, E.L.; Boersma, L.; Ekasingh, M.

    1990-01-01

    The influence of water stress at two soil temperatures on allocation of net photoassimilated carbon in soybean (Glycine max [L.] Merr.) was investigated using compartmental analysis. The experimental phase employed classical 14 C labeling methodology with plants equilibrated at soil water potentials of -0.04, -0.25 and -0.50 MPa; and soil temperatures of 25 and 10C. Carbon immobilization in the shoot apex generally followed leaf elongation rates with decreases in both parameters at increasing water stress at both soil temperatures. However, where moderate water stress resulted in dramatic declines in leaf elongation rates, carbon immobilization rates were sharply decreased only at severe water stress levels. Carbon immobilization was decreased in the roots and nodules of the nonwater stressed treatment by the lower soil temperature. This relation was reversed with severe water stress, and carbon immobilization in the roots and nodules was increased at the lower soil temperature. Apparently, the increased demand for growth and/or carbon storage in these tissues with increased water stress overcame the low soil temperature limitations. Both carbon pool sizes and partitioning of carbon to the sink tissues increased with moderate water stress at 25C soil temperature. Increased pool sizes were consistent with whole plant osmotic adjustment at moderate water stress. Increased partitioning to the sinks was consistent with carbon translocation processes being less severely influenced by water stress than is photosynthesis

  1. Integration of space heating and hot water supply in low temperature district heating

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

    2016-01-01

    District heating may supply many consumers efficiently, but the heat loss from the pipes to the ground is a challenge. The heat loss may be lowered by decreasing the network temperatures for which reason low temperature networks are proposed for future district heating. The heating demand...... of the consumers involves both domestic hot water and space heating. Space heating may be provided at low temperature in low energy buildings. Domestic hot water, however, needs sufficient temperatures to avoid growth of legionella. If the network temperature is below the demand temperature, supplementary heating...... is required by the consumer. We study conventional district heating at different temperatures and compare the energy and exergetic efficiency and annual heating cost to solutions that utilize electricity for supplementary heating of domestic hot water in low temperature district heating. This includes direct...

  2. Analysis of the Sales Promotion in Choice Retail Outlet

    OpenAIRE

    HUMPOLCOVÁ, Michaela

    2010-01-01

    My bachelor thesis is aimed at sales promotion in a retail outlet. The main aim of this thesis is evaluate the current state of sales promotion in a selected retail outlet and based on the analysis of the current state of sales promotion in the outlet to try to propose some measures of improve.

  3. 14 CFR 25.977 - Fuel tank outlet.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank outlet. 25.977 Section 25.977... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System § 25.977 Fuel tank outlet. (a) There must be a fuel strainer for the fuel tank outlet or for the booster pump. This strainer must— (1) For...

  4. 14 CFR 29.977 - Fuel tank outlet.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank outlet. 29.977 Section 29.977... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System § 29.977 Fuel tank outlet. (a) There must be a fuel strainer for the fuel tank outlet or for the booster pump. This strainer must— (1) For...

  5. 14 CFR 27.977 - Fuel tank outlet.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank outlet. 27.977 Section 27.977... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.977 Fuel tank outlet. (a) There must be a fuel stainer for the fuel tank outlet or for the booster pump. This strainer must— (1) For...

  6. Alcohol Outlet Density and Intimate Partner Violence in a Nonmetropolitan College Town: Accounting for Neighborhood Characteristics and Alcohol Outlet Types.

    Science.gov (United States)

    Snowden, Aleksandra J

    2016-01-01

    There is a growing evidence of an ecological association between alcohol outlet density and intimate partner violence. It is reasonable to assume, however, that not all types of alcohol outlets contribute equally to criminal behavior, and to date, most ecological studies have been of large urban cities. Using Bloomington, Indiana, block groups as units of analysis and controlling for several structural characteristics associated with violence rates, I estimated spatially lagged regression models to determine if the variation in alcohol outlet density, including total outlets and disaggregating by on- and off-premise outlets, is related to intimate partner violence density. Results suggested that total alcohol outlet density and off-premise alcohol outlet density were significantly associated with intimate partner violence density. On-premise alcohol outlet density was not significantly associated with intimate partner violence density. These results not only extend the geographic scope of this relationship beyond large metropolitan areas but also have important policy implications.

  7. Influence of water temperature on the economic value of growth rate in fish farming

    NARCIS (Netherlands)

    Besson, M.; Vandeputte, M.; Arendonk, van J.A.M.; Aubin, J.; Boer, de I.J.M.; Quillet, E.; Komen, H.

    2016-01-01

    In sea cage farming, fish are exposed to seasonal variations of water temperature, and these variations can differ from one location to another. A small increase in water temperature does not only stimulate growth of the fish (until an optimal level) but also lowers dissolved oxygen concentration

  8. Root-zone temperature and water availability affect early root growth of planted longleaf pine

    Science.gov (United States)

    M.A. Sword

    1995-01-01

    Longleaf pine seedlings from three seed sources were exposed to three root-zone temperatures and three levels of water availability for 28 days. Root growth declined as temperature and water availability decreased. Root growth differed by seed source. Results suggest that subtle changes in the regeneration environment may influence early root growth of longleaf pine...

  9. Biodegradation of Toluene Under Seasonal and Diurnal Fluctuations of Soil-Water Temperature.

    Science.gov (United States)

    Yadav, Brijesh K; Shrestha, Shristi R; Hassanizadeh, S Majid

    2012-09-01

    An increasing interest in bioremediation of hydrocarbon polluted sites raises the question of the influence of seasonal and diurnal changes on soil-water temperature on biodegradation of BTEX, a widespread group of (sub)-surface contaminants. Therefore, we investigated the impact of a wide range of varying soil-water temperature on biodegradation of toluene under aerobic conditions. To see the seasonal impact of temperature, three sets of batch experiments were conducted at three different constant temperatures: 10°C, 21°C, and 30°C. These conditions were considered to represent (1) winter, (2) spring and/or autumn, and (3) summer seasons, respectively, at many polluted sites. Three additional sets of batch experiments were performed under fluctuating soil-water temperature cases (2110°C, 3021°C, and 1030°C) to mimic the day-night temperature patterns expected during the year. The batches were put at two different temperatures alternatively to represent the day (high-temperature) and night (low-temperature) times. The results of constant- and fluctuating-temperature experiments show that toluene degradation is strongly dependent on soil-water temperature level. An almost two-fold increase in toluene degradation time was observed for every 10°C decrease in temperature for constant-temperature cases. Under fluctuating-temperature conditions, toluene degraders were able to overcome the temperature stress and continued thriving during all considered weather scenarios. However, a slightly longer time was taken compared to the corresponding time at daily mean temperature conditions. The findings of this study are directly useful for bioremediation of hydrocarbon-polluted sites having significant diurnal and seasonal variations of soil-water temperature.

  10. Biodegradation of Toluene Under Seasonal and Diurnal Fluctuations of Soil-Water Temperature.

    KAUST Repository

    Yadav, Brijesh K; Shrestha, Shristi R; Hassanizadeh, S Majid

    2012-01-01

    An increasing interest in bioremediation of hydrocarbon polluted sites raises the question of the influence of seasonal and diurnal changes on soil-water temperature on biodegradation of BTEX, a widespread group of (sub)-surface contaminants. Therefore, we investigated the impact of a wide range of varying soil-water temperature on biodegradation of toluene under aerobic conditions. To see the seasonal impact of temperature, three sets of batch experiments were conducted at three different constant temperatures: 10°C, 21°C, and 30°C. These conditions were considered to represent (1) winter, (2) spring and/or autumn, and (3) summer seasons, respectively, at many polluted sites. Three additional sets of batch experiments were performed under fluctuating soil-water temperature cases (21<>10°C, 30<>21°C, and 10<>30°C) to mimic the day-night temperature patterns expected during the year. The batches were put at two different temperatures alternatively to represent the day (high-temperature) and night (low-temperature) times. The results of constant- and fluctuating-temperature experiments show that toluene degradation is strongly dependent on soil-water temperature level. An almost two-fold increase in toluene degradation time was observed for every 10°C decrease in temperature for constant-temperature cases. Under fluctuating-temperature conditions, toluene degraders were able to overcome the temperature stress and continued thriving during all considered weather scenarios. However, a slightly longer time was taken compared to the corresponding time at daily mean temperature conditions. The findings of this study are directly useful for bioremediation of hydrocarbon-polluted sites having significant diurnal and seasonal variations of soil-water temperature.

  11. Biodegradation of Toluene Under Seasonal and Diurnal Fluctuations of Soil-Water Temperature.

    KAUST Repository

    Yadav, Brijesh K

    2012-05-12

    An increasing interest in bioremediation of hydrocarbon polluted sites raises the question of the influence of seasonal and diurnal changes on soil-water temperature on biodegradation of BTEX, a widespread group of (sub)-surface contaminants. Therefore, we investigated the impact of a wide range of varying soil-water temperature on biodegradation of toluene under aerobic conditions. To see the seasonal impact of temperature, three sets of batch experiments were conducted at three different constant temperatures: 10°C, 21°C, and 30°C. These conditions were considered to represent (1) winter, (2) spring and/or autumn, and (3) summer seasons, respectively, at many polluted sites. Three additional sets of batch experiments were performed under fluctuating soil-water temperature cases (21<>10°C, 30<>21°C, and 10<>30°C) to mimic the day-night temperature patterns expected during the year. The batches were put at two different temperatures alternatively to represent the day (high-temperature) and night (low-temperature) times. The results of constant- and fluctuating-temperature experiments show that toluene degradation is strongly dependent on soil-water temperature level. An almost two-fold increase in toluene degradation time was observed for every 10°C decrease in temperature for constant-temperature cases. Under fluctuating-temperature conditions, toluene degraders were able to overcome the temperature stress and continued thriving during all considered weather scenarios. However, a slightly longer time was taken compared to the corresponding time at daily mean temperature conditions. The findings of this study are directly useful for bioremediation of hydrocarbon-polluted sites having significant diurnal and seasonal variations of soil-water temperature.

  12. National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Pacific Remote Island Areas from 2011 to 2016

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

  13. National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in American Samoa from 2012 to 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

  14. National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Hawaiian Archipelago from 2010 to 2016

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

  15. National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Marianas Archipelago from 2011 to 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

  16. Environmentally Assisted Cracking of Alloys at Temperatures near and above the Critical Temperature of Water

    International Nuclear Information System (INIS)

    Watanabe, Yutaka

    2008-01-01

    Physical properties of water, such as dielectric constant and ionic product, significantly vary with the density of water. In the supercritical conditions, since density of water widely varies with pressure, pressure has a strong influence on physical properties of water. Dielectric constant represents a character of water as a solvent, which determines solubility of an inorganic compound including metal oxides. Dissociation equilibrium of an acid is also strongly dependent on water density. Dissociation constant of acid rises with increased density of water, resulting in drop of pH. Density of water and the density-related physical properties of water, therefore, are the major governing factors of corrosion and environmentally assisted cracking of metals in supercritical aqueous solutions. This paper discusses importance of 'physical properties of water' in understanding corrosion and cracking behavior of alloys in supercritical water environments, based on experimental data and estimated solubility of metal oxides. It has been pointed out that the water density can have significant effects on stress corrosion cracking (SCC) susceptibility of metals in supercritical water, when dissolution of metal plays the key role in the cracking phenomena

  17. Water infiltration in an aquifer recharge basin affected by temperature and air entrapment

    Directory of Open Access Journals (Sweden)

    Loizeau Sébastien

    2017-09-01

    Full Text Available Artificial basins are used to recharge groundwater and protect water pumping fields. In these basins, infiltration rates are monitored to detect any decrease in water infiltration in relation with clogging. However, miss-estimations of infiltration rate may result from neglecting the effects of water temperature change and air-entrapment. This study aims to investigate the effect of temperature and air entrapment on water infiltration at the basin scale by conducting successive infiltration cycles in an experimental basin of 11869 m2 in a pumping field at Crepieux-Charmy (Lyon, France. A first experiment, conducted in summer 2011, showed a strong increase in infiltration rate; which was linked to a potential increase in ground water temperature or a potential dissolution of air entrapped at the beginning of the infiltration. A second experiment was conducted in summer, to inject cold water instead of warm water, and also revealed an increase in infiltration rate. This increase was linked to air dissolution in the soil. A final experiment was conducted in spring with no temperature contrast and no entrapped air (soil initially water-saturated, revealing a constant infiltration rate. Modeling and analysis of experiments revealed that air entrapment and cold water temperature in the soil could substantially reduce infiltration rate over the first infiltration cycles, with respective effects of similar magnitude. Clearly, both water temperature change and air entrapment must be considered for an accurate assessment of the infiltration rate in basins.

  18. Bursting Events in Pressure Flushing with Expanding Bottom Outlet Channel within Dam Reservoir

    Directory of Open Access Journals (Sweden)

    soheila Tofighi

    2017-01-01

    Full Text Available Introduction: Currently, large dams in the world, due to the high amount of sediments in the reservoir, especially around the intake, have operational problems. One of the solutions for this problem is pressure flushing. In this type of flushing, a mixture of water and sediment is removed from bottom outlets form dam reservoir and a funnel shaped crater is created in the vicinity of the outlet opening. In laboratory experiments carried out in this study, pressure flushing with the expansion of bottom outlet within the reservoir and its statistical analysis of bursting events were investigated. The structure of the turbulent flow is not fully understood due to their complexity and random nature. Klein et al. Introduced the turbulence bursting in this kind of flow and Nezo and Nakagora suggested that the events resulting from turbulence bursting has a significant effect of transferring the sediment particles. Materials and Methods: For the purposes of this study, the experiments were conducted with a physical model with 7m length, 1.4m width, and 1.5m height, consisting of three parts namely the inlet of the model, the main reservoir, and settling basin. The main reservoir of the model was 5m long and the sediments were placed within this part of the model. The sediment particles were non-cohesive silica with uniform size and with median diameter (d50 1.15mm and geometrics standard deviation (σg 1.37. Experiments carried out with different discharges and water depths above the bottom outlet in different expansion size of outlet channel in constant sediment level of 20cm above the center of the outlet channel. The model was slowly filled with water until the water surface elevation reached to a desired level. The bottom outlet was manually opened, after a while sedimentwere discharged with the water flow in very high concentrations through the outlet channel (sudden discharge and a funnel shaped crater was formed in front of it. After the run of

  19. Experimental study on the operating characteristics of an inner preheating transpiring wall reactor for supercritical water oxidation: Temperature profiles and product properties

    International Nuclear Information System (INIS)

    Zhang, Fengming; Xu, Chunyan; Zhang, Yong; Chen, Shouyan; Chen, Guifang; Ma, Chunyuan

    2014-01-01

    A new process to generate multiple thermal fluids by supercritical water oxidation (SCWO) was proposed to enhance oil recovery. An inner preheating transpiring wall reactor for SCWO was designed and tested to avoid plugging in the preheating section. Hot water (400–600 °C) was used as auxiliary heat source to preheat the feed to the reaction temperature. The effect of different operating parameters on the performance of the inner preheating transpiring wall reactor was investigated, and the optimized operating parameters were determined based on temperature profiles and product properties. The reaction temperature is close to 900 °C at an auxiliary heat source flow of 2.79 kg/h, and the auxiliary heat source flow is determined at 6–14 kg/h to avoid the overheating of the reactor. The useful reaction time is used to quantitatively describe the feed degradation efficiency. The outlet concentration of total organic carbon (TOC out ) and CO in the effluent gradually decreases with increasing useful reaction time. The useful reaction time needed for complete oxidation of the feed is 10.5 s for the reactor. - Highlights: • A new process to generate multiple thermal fluids by SCWO was proposed. • An inner preheating transpiring wall reactor for SCWO was designed and tested. • Hot water was used as auxiliary heat source to preheat the feed at room temperature. • Effect of operating parameters on the performance of the reactor was investigated. • The useful reaction time required for complete oxidation of the feed is 10.5 s

  20. SU-F-T-492: The Impact of Water Temperature On Absolute Dose Calibration

    International Nuclear Information System (INIS)

    Islam, N; Podgorsak, M

    2016-01-01

    Purpose: The Task Group 51 (TG 51) protocol prescribes that dose calibration of photon beams be done by irradiating an ionization chamber in a water tank at pre-defined depths. Methodologies are provided to account for variations in measurement conditions by applying correction factors. However, the protocol does not completely account for the impact of water temperature. It is well established that water temperature will influence the density of air in the ion chamber collecting volume. Water temperature, however, will also influence the size of the collecting volume via thermal expansion of the cavity wall and the density of the water in the tank. In this work the overall effect of water temperature on absolute dosimetry has been investigated. Methods: Dose measurements were made using a Farmer-type ion chamber for 6 and 23 MV photon beams with water temperatures ranging from 10 to 40°C. A reference ion chamber was used to account for fluctuations in beam output between successive measurements. Results: For the same beam output, the dose determined using TG 51 was dependent on the temperature of the water in the tank. A linear regression of the data suggests that the dependence is statistically significant with p-values of the slope equal to 0.003 and 0.01 for 6 and 23 MV beams, respectively. For a 10 degree increase in water phantom temperature, the absolute dose determined with TG 51 increased by 0.27% and 0.31% for 6 and 23 MV beams, respectively. Conclusion: There is a measurable effect of water temperature on absolute dose calibration. To account for this effect, a reference temperature can be defined and a correction factor applied to account for deviations from this reference temperature during beam calibration. Such a factor is expected to be of similar magnitude to most of the existing TG 51 correction factors.

  1. SU-F-T-492: The Impact of Water Temperature On Absolute Dose Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Islam, N [State University of New York at Buffalo, Buffalo, NY (United States); Podgorsak, M [State University of New York at Buffalo, Buffalo, NY (United States); Roswell Park Cancer Institute, Buffalo, NY (United States)

    2016-06-15

    Purpose: The Task Group 51 (TG 51) protocol prescribes that dose calibration of photon beams be done by irradiating an ionization chamber in a water tank at pre-defined depths. Methodologies are provided to account for variations in measurement conditions by applying correction factors. However, the protocol does not completely account for the impact of water temperature. It is well established that water temperature will influence the density of air in the ion chamber collecting volume. Water temperature, however, will also influence the size of the collecting volume via thermal expansion of the cavity wall and the density of the water in the tank. In this work the overall effect of water temperature on absolute dosimetry has been investigated. Methods: Dose measurements were made using a Farmer-type ion chamber for 6 and 23 MV photon beams with water temperatures ranging from 10 to 40°C. A reference ion chamber was used to account for fluctuations in beam output between successive measurements. Results: For the same beam output, the dose determined using TG 51 was dependent on the temperature of the water in the tank. A linear regression of the data suggests that the dependence is statistically significant with p-values of the slope equal to 0.003 and 0.01 for 6 and 23 MV beams, respectively. For a 10 degree increase in water phantom temperature, the absolute dose determined with TG 51 increased by 0.27% and 0.31% for 6 and 23 MV beams, respectively. Conclusion: There is a measurable effect of water temperature on absolute dose calibration. To account for this effect, a reference temperature can be defined and a correction factor applied to account for deviations from this reference temperature during beam calibration. Such a factor is expected to be of similar magnitude to most of the existing TG 51 correction factors.

  2. Stable solid state reference electrodes for high temperature water chemistry

    International Nuclear Information System (INIS)

    Jayaweera, P.; Millett, P.J.

    1995-01-01

    A solid state electrode capable of providing a stable reference potential under a wide range of temperatures and chemical conditions has been demonstrated. The electrode consists of a zirconia or yttria-stabilized zirconia tube packed with an inorganic polymer electrolyte and a silver/silver chloride sensing element. The sensing element is maintained near room temperature by a passive cooling heat sink. The electrode stability was demonstrated by testing it in high temperature (280 C) aqueous solutions over extended periods of time. This reference electrode is useful in many applications, particularly for monitoring the chemistry in nuclear and fossil power plants

  3. Water-level sensor and temperature-profile detector

    Science.gov (United States)

    Not Available

    1981-01-29

    A temperature profile detector is described which comprises a surrounding length of metal tubing and an interior electrical conductor both constructed of high temperature high electrical resistance materials. A plurality of gas-filled expandable bellows made of electrically conductive material are positioned at spaced locations along a length of the conductors. The bellows are sealed and contain a predetermined volume of a gas designed to effect movement of the bellows from an open circuit condition to a closed circuit condition in response to monitored temperature changes sensed by each bellows.

  4. Coupling Meteorological, Land Surface and Water Temperature Models in the Mississippi River Basin

    Science.gov (United States)

    Tang, C.; Cooter, E. J.

    2017-12-01

    Water temperature is a significant factor influencing of the stream ecosystem and water management especially under climate change. In this study, we demonstrate a physically based semi-Lagrangian water temperature model (RBM) coupled with the Variable Infiltration Capacity (VIC) hydrology model and Weather Research & Forecasting Model (WRF) in the Mississippi River Basin (MRB). The results of this coupling compare favorably with observed water temperature data at river gages throughout the MRB. Further sensitivity analysis shows that mean water temperatures increase by 1.3°C, 1.5°C, and 1.8°C in northern, central and southern MRB zones, respectively, under a hypothetical uniform air temperature increase of 3°C. If air temperatures increase uniformly by 6°C in this scenario, then water temperatures are projected to increase by 3.3°C, 3.5°C and 4.0°C. Lastly, downscaled air temperatures from a global climate model are used to drive the coupled VIC and RBM model from 2020 to 2099. Average stream temperatures from 2020 to 2099 increase by 1°C to 8°C above 1950 to 2010 average water temperatures, with non-uniform increases along the river. In some portions of the MRB, stream temperatures could increase above survival thresholds for several native fish species, which are critical components of the stream ecosystem. The increased water temperature accelerates harmful algal blooming which results in a larger dead zone in the Gulf of Mexico.

  5. Combined ground- and satellite-based profiling of temperature and water vapor

    International Nuclear Information System (INIS)

    Stankov, B.B.; Westwater, E.R.; Snider, J.B.; Churnside, J.H.

    1994-01-01

    The fusion or integration of meteorological and radiative data from a range of instrumentation into a representative picture of temperature, water vapor, and clouds over a CART domain will be a challenging task for four-dimensional data assimilation models. In the work reported here, we have summarized work supported by DOE's algorithm development program including combined RASS and TIROS Operational Vertical Sounder (TOVS) temperature sensing, water vapor profiles from dual-channel radiometers, and neural network radiometric temperature retrievals

  6. Identifying (subsurface) anthropogenic heat sources that influence temperature in the drinking water distribution system

    Science.gov (United States)

    Agudelo-Vera, Claudia M.; Blokker, Mirjam; de Kater, Henk; Lafort, Rob

    2017-09-01

    The water temperature in the drinking water distribution system and at customers' taps approaches the surrounding soil temperature at a depth of 1 m. Water temperature is an important determinant of water quality. In the Netherlands drinking water is distributed without additional residual disinfectant and the temperature of drinking water at customers' taps is not allowed to exceed 25 °C. In recent decades, the urban (sub)surface has been getting more occupied by various types of infrastructures, and some of these can be heat sources. Only recently have the anthropogenic sources and their influence on the underground been studied on coarse spatial scales. Little is known about the urban shallow underground heat profile on small spatial scales, of the order of 10 m × 10 m. Routine water quality samples at the tap in urban areas have shown up locations - so-called hotspots - in the city, with relatively high soil temperatures - up to 7 °C warmer - compared to the soil temperatures in the surrounding rural areas. Yet the sources and the locations of these hotspots have not been identified. It is expected that with climate change during a warm summer the soil temperature in the hotspots can be above 25 °C. The objective of this paper is to find a method to identify heat sources and urban characteristics that locally influence the soil temperature. The proposed method combines mapping of urban anthropogenic heat sources, retrospective modelling of the soil temperature, analysis of water temperature measurements at the tap, and extensive soil temperature measurements. This approach provided insight into the typical range of the variation of the urban soil temperature, and it is a first step to identifying areas with potential underground heat stress towards thermal underground management in cities.

  7. The analysis of energy efficiency in water electrolysis under high temperature and high pressure

    Science.gov (United States)

    Hourng, L. W.; Tsai, T. T.; Lin, M. Y.

    2017-11-01

    This paper aims to analyze the energy efficiency of water electrolysis under high pressure and high temperature conditions. The effects of temperature and pressure on four different kinds of reaction mechanisms, namely, reversible voltage, activation polarization, ohmic polarization, and concentration polarization, are investigated in details. Results show that the ohmic and concentration over-potentials are increased as temperature is increased, however, the reversible and activation over-potentials are decreased as temperature is increased. Therefore, the net efficiency is enhanced as temperature is increased. The efficiency of water electrolysis at 350°C/100 bars is increased about 17%, compared with that at 80°C/1bar.

  8. Effect of temperature on anaerobic treatment of black water in UASB-septic tank systems

    NARCIS (Netherlands)

    Luostarinen, S.; Sanders, W.T.M.; Kujawa-Roeleveld, K.; Zeeman, G.

    2007-01-01

    The effect of northern European seasonal temperature changes and low temperature on the performance of upflow anaerobic sludge blanket (UASB)-septic tanks treating black water was studied. Three UASB-septic tanks were monitored with different operational parameters and at different temperatures. The

  9. Surf zone entrainment, along-shore transport, and human health implications of pollution from tidal outlets

    Science.gov (United States)

    Grant, S. B.; Kim, J. H.; Jones, B. H.; Jenkins, S. A.; Wasyl, J.; Cudaback, C.

    2005-10-01

    Field experiments and modeling studies were carried out to characterize the surf zone entrainment and along-shore transport of pollution from two tidal outlets that drain into Huntington Beach and Newport Beach, popular public beaches in southern California. The surf zone entrainment and near-shore transport of pollutants from these tidal outlets appears to be controlled by prevailing wave conditions and coastal currents, and fine-scale features of the flow field around the outlets. An analysis of data from dye experiments and fecal indicator bacteria monitoring studies reveals that the along-shore flux of surf zone water is at least 50 to 300 times larger than the cross-shore flux of surf zone water. As a result, pollutants entrained in the surf zone hug the shore, where they travel significant distances parallel to the beach before diluting to extinction. Under the assumption that all surf zone pollution at Huntington Beach originates from two tidal outlets, the Santa Ana River and Talbert Marsh outlets, models of mass and momentum transport in the surf zone approximately capture the observed tidal phasing and magnitude of certain fecal indicator bacteria groups (total coliform) but not others (Escherichia coli and enterococci), implying the existence of multiple sources of, and/or multiple transport pathways for, fecal pollution at this site. The intersection of human recreation and near-shore pollution pathways implies that, from a human health perspective, special care should be taken to reduce the discharge of harmful pollutants from land-side sources of surface water runoff, such as tidal outlets and storm drains.

  10. Catchment power and the joint distribution of elevation and travel distance to the outlet

    Directory of Open Access Journals (Sweden)

    L. S. Sklar

    2016-10-01

    Full Text Available The delivery of water, sediment, and solutes by catchments is influenced by the distribution of source elevations and their travel distances to the outlet. For example, elevation affects the magnitude and phase of precipitation, as well as the climatic factors that govern rock weathering, which influence the production rate and initial particle size of sediments. Travel distance, in turn, affects the timing of flood peaks at the outlet and the degree of sediment size reduction by wear, which affects particle size distributions at the outlet. The distributions of elevation and travel distance have been studied extensively but separately, as the hypsometric curve and width function. Yet a catchment can be considered as a collection of points, each with paired values of elevation and travel distance. For every point, the ratio of elevation to travel distance defines the mean slope for transport of mass to the outlet. Recognizing that mean slope is proportional to the average rate of loss of potential energy by water and sediment during transport to the outlet, we use the joint distribution of elevation and travel distance to define two new metrics for catchment geometry: "source-area power", and the corresponding catchment-wide integral "catchment power". We explore patterns in source-area and catchment power across three study catchments spanning a range of relief and drainage area. We then develop an empirical algorithm for generating synthetic source-area power distributions, which can be parameterized with data from natural catchments. This new way of quantifying the three-dimensional geometry of catchments can be used to explore the effects of topography on the distribution on fluxes of water, sediment, isotopes, and other landscape products passing through catchment outlets, and may provide a fresh perspective on problems of both practical and theoretical interest.

  11. Ground-water temperature of the Wyoming quadrangle in central Delaware : with application to ground-water-source heat pumps

    Science.gov (United States)

    Hodges, Arthur L.

    1982-01-01

    Ground-water temperature was measured during a one-year period (1980-81) in 20 wells in the Wyoming Quadrangle in central Delaware. Data from thermistors set at fixed depths in two wells were collected twice each week, and vertical temperature profiles of the remaining 18 wells were made monthly. Ground-water temperature at 8 feet below land surface in well Jc55-1 ranged from 45.0 degrees F in February to 70.1 degrees F in September. Temperature at 35 feet below land surface in the same well reached a minimum of 56.0 degrees F in August, and a maximum of 57.8 degrees F in February. Average annual temperature of ground water at 25 feet below land surface in all wells ranged from 54.6 degrees F to 57.8 degrees F. Variations of average temperature probably reflect the presence or absence of forestation in the recharge areas of the wells. Ground-water-source heat pumps supplied with water from wells 30 or more feet below land surface will operate more efficiently in both heating and cooling modes than those supplied with water from shallower depths. (USGS)

  12. Possible effects of regulating hydroponic water temperature on plant ...

    African Journals Online (AJOL)

    Yomi

    2010-12-29

    Dec 29, 2010 ... temperature on plant growth, accumulation of nutrients and other metabolites ... Padda and Picha, 2008), a defensive mechanism em- ployed by plants ..... and flower development will vary depending on the growth stage of ...

  13. Effect of water temperature on biofouling development in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia

    2016-07-14

    Understanding the factors that determine the spatial and temporal biofilm development is a key to formulate effective control strategies in reverse osmosis membrane systems for desalination and wastewater reuse. In this study, biofilm development was investigated at different water temperatures (10, 20, and 30 °C) inside a membrane fouling simulator (MFS) flow cell. The MFS studies were done at the same crossflow velocity with the same type of membrane and spacer materials, and the same feed water type and nutrient concentration, differing only in water temperature. Spatially resolved biofilm parameters such as oxygen decrease rate, biovolume, biofilm spatial distribution, thickness and composition were measured using in-situ imaging techniques. Pressure drop (PD) increase in time was used as a benchmark as to when to stop the experiments. Biofilm measurements were performed daily, and experiments were stopped once the average PD increased to 40 mbar/cm. The results of the biofouling study showed that with increasing feed water temperature (i) the biofilm activity developed faster, (ii) the pressure drop increased faster, while (iii) the biofilm thickness decreased. At an average pressure drop increase of 40 mbar/cm over the MFS for the different feed water temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high temperature feed water are more susceptible to biofouling than installations fed with low temperature feed water.

  14. Summer Season Water Temperature Modeling under the Climate Change: Case Study for Fourchue River, Quebec, Canada

    Directory of Open Access Journals (Sweden)

    Jaewon Kwak

    2017-05-01

    Full Text Available It is accepted that human-induced climate change is unavoidable and it will have effects on physical, chemical, and biological properties of aquatic habitats. This will be especially important for cold water fishes such as trout. The objective of this study is to simulate water temperature for future periods under the climate change situations. Future water temperature in the Fourchue River (St-Alexandre-de-Kamouraska, QC, Canada were simulated by the CEQUEAU hydrological and water temperature model, using meteorological inputs from the Coupled Model Intercomparison Project Phase 5 (CMIP5 Global Circulation Models (GCMs with Representative Concentration Pathway (RCP 2.6, 4.5 and 8.5 climate change scenarios. The result of the study indicated that water temperature in June will increase 0.2–0.7 °C and that in September, median water temperature could decrease by 0.2–1.1 °C. The rise in summer water temperature may be favorable to brook trout (Salvelinus fontinalis growth, but several days over the Upper Incipient Lethal Temperature (UILT are also likely to occur. Therefore, flow regulation procedures, including cold water releases from the Morin dam may have to be considered for the Fourchue River.

  15. A Mathematical Model of a Thermally Activated Roof (TAR Cooling System Using a Simplified RC-Thermal Model with Time Dependent Supply Water Temperature

    Directory of Open Access Journals (Sweden)

    Khalid Ahmed Joudi

    2017-01-01

    Full Text Available This paper presents a computer simulation model of a thermally activated roof (TAR to cool a room using cool water from a wet cooling tower. Modeling was achieved using a simplified 1-D resistance-capacitance thermal network (RC model for an infinite slab. Heat transfer from the cooling pipe network was treated as 2-D heat flow. Only a limited number of nodes were required to obtain reliable results. The use of 6th order RC-thermal model produced a set of ordinary differential equations that were solved using MATLAB - R2012a. The computer program was written to cover all possible initial conditions, material properties, TAR system geometry and hourly solar radiation. The cool water supply was considered time dependent with the variation of the ambient wet bulb temperature. Results from RC-thermal modeling were compared with experimental measurements for a second story room measuring 5.5 m x 4 m x 3 m at Amarah city/ Iraq (31.865 ˚N, 47.128 ˚E for 21 July, 2013. The roof was constructed of 200 mm concrete slab, 150 mm turf and 50 mm insulation. Galvanized 13 mm steel pipe coils were buried in the roof slab with a pipe occupation ratio of 0.12. The walls were constructed of 240 mm common brick with 10mm cement plaster on the inside and outside surfaces and 20 mm Styrofoam insulation on the inside surface and covered with PVC panel. Thermistors were used to measure the indoor and outdoor temperatures, TAR system water inlet and outlet temperatures and temperature distribution inside the concrete slab. The effect of pipe spacing and water mass flow rate were evaluated. Agreement was good between the experimental and RC-thermal model. Concrete core temperature reaches the supply water temperature faster for lower pipe spacing. Heat extracted from the space increased with water mass flow rate to an optimum of 0.0088 kg/s.m².

  16. Electrode for improving electrochemical measurements in high temperature water

    International Nuclear Information System (INIS)

    Sengarsai, T.

    2005-01-01

    A silver/silver-chloride (Ag/AgCl) reference electrode was specially designed and constructed in a body of oxidized titanium for potentiometric measurements under high-temperature and high-pressure conditions. To avoid the thermal decomposition of silver-chloride, the electrode is designed to maintain the reference element at low temperature while it is still connected to high-temperature process zone via a non-isothermal electrolyte bridge. This configuration leads to the development of a thermal gradient along the length of the electrode. At room temperature, the stability of the Ag/AgCl reference electrode versus a standard calomel electrode (SCE) is maintained with an accuracy of 5 mV. The electrode's performance at high temperature and pressure (up to 300 o C and 1500 psi) was examined by measuring the potential difference against platinum, which acted as a reversible hydrogen electrode (RHE). Comparison of the experimental and theoretical values verifies the reliability and reproducibility of the electrode. Deviation from the Nernst equation is considered and related to the thermal liquid junction potential (TLJP). An empirical correction factor is used to maintain the Ag/AgCl potential within an acceptable accuracy limit of ±20 mV at high temperature. (author)

  17. Effect of seasonal changes in use patterns and cold inlet water temperature on water-heating loads

    Energy Technology Data Exchange (ETDEWEB)

    Abrams, D.W.; Shedd, A.C. [D.W. Abrams, P.E. and Associates, Atlanta, GA (United States)

    1996-11-01

    This paper presents long-term test data obtained in 20 commercial buildings and 16 residential sites. The information illustrates the effects of variations in hot water load determinants and the effect on energy use. It also is useful as a supplement to the load profiles presented in the ASHRAE Handbooks and other design references. The commercial facilities include supermarkets, fast-food restaurants, full-service restaurants, commercial kitchens, a motel, a nursing home, a hospital, a bakery, and laundry facilities. The residential sites ere selected to provide test sites with higher-than-average hot water use. They include 13 single-family detached residences, one 14-unit apartment building, and two apartment laundries. Test data are available at measurement intervals of 1 minute for the residential sites and 15 minutes for the commercial sites. Summary data in tabular and graphical form are presented for average daily volumetric hot water use and cold inlet water temperature. Measured cold inlet water temperature and volumetric hot water use figures are compared to values typically used for design and analysis. Conclusions are offered regarding the effect of cold water inlet temperature and variations in hot water use on water-heating load and energy use. Recommendations for the use of the information presented in water-heating system design, performance optimization, and performance analysis conclude the paper.

  18. Operativ behandling af thoracic outlet syndrome

    DEFF Research Database (Denmark)

    Birkeland, Peter; Stiasny, Jerzy

    2012-01-01

    of the brachial plexus. At surgery, we found and severed a fibrous band that compressed the inferior trunk. Postoperatively, the pain subsided and fine hand movements improved. One patient had no cervical rib, however, in the two other cases we found rudimentary cervical ribs. Magnetic resonance imaging......We present three cases with longstanding true neurogenic thoracic outlet syndrome. All patients had aching pain in the shoulder, arm and ulnar border of the hand. On examination, we found atrophy of the hand muscles. Electromyography revealed signs of compromised function of the inferior trunk...

  19. Proxy comparisons for Paleogene sea water temperature reconstructions

    Science.gov (United States)

    de Bar, Marijke; de Nooijer, Lennart; Schouten, Stefan; Ziegler, Martin; Sluijs, Appy; Reichart, Gert-Jan

    2017-04-01

    Several studies have reconstructed Paleogene seawater temperatures, using single- or multi-proxy approaches (e.g. Hollis et al., 2012 and references therein), particularly comparing TEX86 with foraminiferal δ18O and Mg/Ca. Whereas trends often agree relatively well, absolute temperatures can differ significantly between proxies, possibly because they are often applied to (extreme) climate events/transitions (e.g. Sluijs et al., 2011), where certain assumptions underlying the temperature proxies may not hold true. A more general long-term multi-proxy temperature reconstruction, is therefore necessary to validate the different proxies and underlying presumed boundary conditions. Here we apply a multi-proxy approach using foraminiferal calcite and organic proxies to generate a low-resolution, long term (80 Myr) paleotemperature record for the Bass River core (New Jersey, North Atlantic). Oxygen (δ18O), clumped isotopes (Δ47) and Mg/Ca of benthic foraminifera, as well as the organic proxies MBT'-CBT, TEX86H, U37K' index and the LDI were determined on the same sediments. The youngest samples of Miocene age are characterized by a high BIT index (>0.8) and fractional abundance of the C32 1,15-diol (>0.6; de Bar et al., 2016) and the absence of foraminifera, all suggesting high continental input and shallow depths. The older sediment layers (˜30 to 90 Ma) display BIT values and C32 1,15-diol fractional abundances 28 ˚ C. In contrast, LDI temperatures were considerably lower and varied only between 21 and 19 ˚ C. MBT'-CBT derived mean annual temperatures for the ages of 9 and 20 Ma align well with the TEX86H SSTs. Overall, the agreement of the paleotemperature proxies in terms of main tendencies, and the covariation with the global benthic oxygen isotope compilation suggests that temperatures in this region varied in concert with global climate variability. The fact that offsets between the different proxies used here remain fairly constant down to 90 Ma ago

  20. Effect of Climate Change on Water Temperature and Attainment of Water Temperature Criteria in the Yaquina Estuary, Oregon (USA)

    Science.gov (United States)

    There is increasing evidence that our planet is warming and this warming is also resulting in rising sea levels. Estuaries which are located at the interface between land and ocean are impacted by these changes. We used CE-QUAL-W2 water quality model to predict changes in water...

  1. Modeling Electricity Sector Vulnerabilities and Costs Associated with Water Temperatures Under Scenarios of Climate Change

    Science.gov (United States)

    Macknick, J.; Miara, A.; Brinkman, G.; Ibanez, E.; Newmark, R. L.

    2014-12-01

    The reliability of the power sector is highly vulnerable to variability in the availability and temperature of water resources, including those that might result from potential climatic changes or from competition from other users. In the past decade, power plants throughout the United States have had to shut down or curtail generation due to a lack of available water or from elevated water temperatures. These disruptions in power plant performance can have negative impacts on energy security and can be costly to address. Analysis of water-related vulnerabilities requires modeling capabilities with high spatial and temporal resolution. This research provides an innovative approach to energy-water modeling by evaluating the costs and reliability of a power sector region under policy and climate change scenarios that affect water resource availability and temperatures. This work utilizes results from a spatially distributed river water temperature model coupled with a thermoelectric power plant model to provide inputs into an electricity production cost model that operates on a high spatial and temporal resolution. The regional transmission organization ISO-New England, which includes six New England states and over 32 Gigawatts of power capacity, is utilized as a case study. Hydrological data and power plant operations are analyzed over an eleven year period from 2000-2010 under four scenarios that include climate impacts on water resources and air temperatures as well as strict interpretations of regulations that can affect power plant operations due to elevated water temperatures. Results of these model linkages show how the power sector's reliability and economic performance can be affected by changes in water temperatures and water availability. The effective reliability and capacity value of thermal electric generators are quantified and discussed in the context of current as well as potential future water resource characteristics.

  2. Temperature distributions in trapezoidal built in storage solar water heaters with/without phase change materials

    International Nuclear Information System (INIS)

    Tarhan, Sefa; Sari, Ahmet; Yardim, M. Hakan

    2006-01-01

    Built in storage solar water heaters (BSSWHs) have been recognized for their more compact constructions and faster solar gain than conventional solar water heaters, however, their water temperatures quickly go down during the cooling period. A trapezoidal BSSWH without PCM storage unit was used as the control heater (reference) to investigate the effect of two differently configured PCM storage units on the temperature distributions in water tanks. In the first design, myristic acid was filled into the PCM storage tank, which also served as an absorbing plate. In the second design, lauric acid was filled into the PCM storage tank, which also served as a baffle plate. The water temperature changes were followed by five thermocouples placed evenly and longitudinally into each of the three BSSWHs. The effects of the PCMs on the water temperature distributions depended on the configuration of the PCM storage unit and the longitudinal position in the water tanks. The use of lauric acid lowered the values of the peak temperatures by 15% compared to the control heater at the upper portion of the water tanks because of the low melting temperature of lauric acid, but it did not have any consistent effect on the retention of the water temperatures during the cooling period. The ability of the myristic acid storage unit to retain the water temperatures got more remarkable, especially at the middle portion of the water tank. The myristic acid storage increased the dip temperatures by approximately 8.8% compared to the control heater. In conclusion, lauric acid storage can be used to stabilize the water temperature during the day time, while the myristic acid storage unit can be used as a thermal barrier against heat loss during the night time because of its relatively high melting temperature and low heat conduction coefficient in its solid phase. The experimental results have also indicated that the thermal characteristics of the PCM and the configuration of the PCM storage

  3. An experimental study on the influence of water stagnation and temperature change on water quality in a full-scale domestic drinking water system.

    Science.gov (United States)

    Zlatanović, Lj; van der Hoek, J P; Vreeburg, J H G

    2017-10-15

    The drinking water quality changes during the transport through distribution systems. Domestic drinking water systems (DDWSs), which include the plumbing between the water meter and consumer's taps, are the most critical points in which water quality may be affected. In distribution networks, the drinking water temperature and water residence time are regarded as indicators of the drinking water quality. This paper describes an experimental research on the influence of stagnation time and temperature change on drinking water quality in a full-scale DDWS. Two sets of stagnation experiments, during winter and summer months, with various stagnation intervals (up to 168 h of stagnation) were carried out. Water and biofilms were sampled at two different taps, a kitchen and a shower tap. Results from this study indicate that temperature and water stagnation affect both chemical and microbial quality in DDWSs, whereas microbial parameters in stagnant water appear to be driven by the temperature of fresh water. Biofilm formed in the shower pipe contained more total and intact cells than the kitchen pipe biofilm. Alphaproteobacteria were found to dominate in the shower biofilm (78% of all Proteobacteria), while in the kitchen tap biofilm Alphaproteobacteria, Betaproteobacteria and Gammaproteobacteria were evenly distributed. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Perspectives on Temperature in the Pacific Northwest's Fresh Waters

    Energy Technology Data Exchange (ETDEWEB)

    Coutant, C.C.

    1999-06-01

    This report provides a perspective on environmental water temperatures in the Pacific Northwest as they relate to the establishment of water temperature standards by the state and their review by the US Environmental Protection Agency. It is a companion to other detailed reviews of the literature on thermal effects on organisms important to the region. Many factors, both natural and anthropogenic, affect water temperatures in the region. Different environmental zones have characteristic temperatures and mechanisms that affect them. There are specific biotic adaptations to environmental temperatures. Life-cycle strategies of salmonids, in particular, are attuned to annual temperature patterns. Physiological and behavioral requirements on key species form the basis of present water temperature criteria, but may need to be augmented with more concern for environmental settings. There are many issues in the setting of standards, and these are discussed. There are also issues in compliance. Alternative temperature-regulating mechanisms are discussed, as are examples of actions to control water temperatures in the environment. Standards-setting is a social process for which this report should provide background and outline options, alternatives, limitations, and other points for discussion by those in the region.

  5. Potential uses of high gradient magnetic filtration for high-temperature water purification in boiling water reactors

    International Nuclear Information System (INIS)

    Elliott, H.H.; Holloway, J.H.; Abbott, D.G.

    1979-01-01

    Studies of various high-temperature filter devices indicate a potentially positive impact for high gradient magnetic filtration on boiling water reactor radiation level reduction. Test results on in-plant water composition and impurity crystallography are presented for several typical boiling water reactors (BWRs) on plant streams where high-temperature filtration may be particularly beneficial. An experimental model on the removal of red iron oxide (hematite) from simulated reactor water with a high gradient magnetic filter is presented, as well as the scale-up parameters used to predict the filtration efficiency on various high temperature, in-plant streams. Numerical examples are given to illustrate the crud removal potential of high gradient magnetic filters installed at alternative stream locations under typical, steady-state, plant operating conditions

  6. Temperature of gas delivered from ventilators.

    Science.gov (United States)

    Chikata, Yusuke; Onodera, Mutsuo; Imanaka, Hideaki; Nishimura, Masaji

    2013-01-01

    Although heated humidifiers (HHs) are the most efficient humidifying device for mechanical ventilation, some HHs do not provide sufficient humidification when the inlet temperature to the water chamber is high. Because portable and home-care ventilators use turbines, blowers, pistons, or compressors to inhale in ambient air, they may have higher gas temperature than ventilators with piping systems. We carried out a bench study to investigate the temperature of gas delivered from portable and home-care ventilators, including the effects of distance from ventilator outlet, fraction of inspiratory oxygen (FIO2), and minute volume (MV). We evaluated five ventilators equipped with turbine, blower, piston, or compressor system. Ambient air temperature was adjusted to 24°C ± 0.5°C, and ventilation was set at FIO2 0.21, 0.6, and 1.0, at MV 5 and 10 L/min. We analyzed gas temperature at 0, 40, 80, and 120 cm from ventilator outlet and altered ventilator settings. While temperature varied according to ventilators, the outlet gas temperature of ventilators became stable after, at the most, 5 h. Gas temperature was 34.3°C ± 3.9°C at the ventilator outlet, 29.5°C ± 2.2°C after 40 cm, 25.4°C ± 1.2°C after 80 cm and 25.1°C ± 1.2°C after 120 cm (P < 0.01). FIO2 and MV did not affect gas temperature. Gas delivered from portable and home-care ventilator was not too hot to induce heated humidifier malfunctioning. Gas soon declined when passing through the limb.

  7. Abandonment of the low level outlet structure at the McGregor South Dam

    Energy Technology Data Exchange (ETDEWEB)

    Mack, D.L; Murray, T.K. [Klohn-Crippen Consultants Ltd., Calgary, AB (Canada); Soutar, B.M. [Alberta Transportation, Edmonton, AB (Canada)

    2008-07-01

    The Carseland-Bow River Headworks (CBRH) is a major multi-purpose water delivery system, situated in southern Alberta. It supplies water to 87,000 hectares of agricultural land and several municipalities. The system was originally built starting in 1909. It consists of diversion works on the Bow River, 65 kilometres of canal, and the McGregor and Little Bow reservoirs. In the 1950s, the system was rehabilitated by the Prairie Farm Rehabilitation Administration (PFRA), and Travers Reservoir was added in 1954. In 1973, ownership and operation of the CBRH system was turned over to Alberta Environment. In 2001, Alberta Transportation implemented a major program to rehabilitate and upgrade the CBRH system. This program included increasing the capacity of the canals and structures, and upgrading the dams to meet current dam safety guidelines. The project involved raising the north and south dams, providing an auxiliary spillway to accommodate the probable maximum flood (PMF), and rehabilitating the existing reservoir inlet and low level outlet structures. This paper discussed the abandonment of the existing low level outlet structure located within the south dam. The paper discussed the existing dams and outlet structure as well as the south dam and outlet structure. The abandonment of the existing low level outlet structure was discussed in terms of general construction; demolition; upstream conduits and gatewell; and downstream conduit. Several illustrations and photographs of the dam and the demolition were presented. It was concluded that the in-place abandonment of the existing low level outlet structure at the McGregor South Dam provides significant advantages, including eliminating the need to construct and remove an extensive cofferdam within the reservoir. 6 refs., 2 tabs., 4 figs.

  8. Interacting temperature and water activity modulate production of ...

    African Journals Online (AJOL)

    West African Journal of Applied Ecology ... Concentrations of DA were further modulated by interactions of temperature and aw. ... was at 0.98 aw and 35°C while the lowest was at 0.96 aw and 35°C. The abiotic interactions that supported biomass production appeared different from what was required for production of DA.

  9. Sensing the water content of honey from temperature-dependent electrical conductivity

    International Nuclear Information System (INIS)

    Guo, Wenchuan; Liu, Yi; Zhu, Xinhua; Zhuang, Hong

    2011-01-01

    In order to predict the water content in honey, electrical conductivity was measured on blossom honey types milk-vetch, jujube and yellow-locust with the water content of 18–37% between 5 and 40 °C. The regression models of electrical conductivity were developed as functions of water content and temperature. The results showed that increases in either water content or temperature resulted in an increase in the electrical conductivity of honey with greater changes at higher water content and/or higher temperature. The linear terms of water content and temperature, a quadratic term of water content, and the interaction effect of water content and temperature had significant influence on the electrical conductivity of honey (p < 0.0001). Regardless of blossom honey type, the linear coefficient of the determination of measured and calculated electrical conductivities was 0.998 and the range error ratio was larger than 100. These results suggest that the electrical conductivity of honey might be used to develop a detector for rapidly predicting the water content in blossom honey

  10. Epidemiology and pathogenesis of thoracic outlet syndrome

    Directory of Open Access Journals (Sweden)

    Wojcik Gustaw

    2015-03-01

    Full Text Available The superior thoracic aperture is a place particularly vulnerable to the occurrence of tissue conflict and the development of a number of neurovascular changes carrying a risk of upper limb dysfunction. The triggering factor in this case is the pressure on the nerve vascular elements brought about by too large muscles of the chest and neck, clavicle fracture and dislocation of the upper ribs, anomalies in the form of ribs, in the neck, or by apex of the lung tumors. Each anatomical anomaly may be a cause of a number of lesions and lead to the development of the disease. Due to the nature of the oppressed structures, there are two basic groups: neurogenic and vascular. The most common variant giving clinical symptoms is neurogenic thoracic outlet syndrome. In this, the compression ratio, the brachial plexus, and for this reason, the vascular surface of the upper limb dysfunction is often overlooked. However, the vascular variant, and especially arterial sub-variant, is very dangerous because it can give complications even in the form of aneurysms, and even upper limb ischemia. The aim of the study is to present the most common changes in the thoracic outlet causing functional disorders of the upper limb.

  11. Evaluation of water cooled supersonic temperature and pressure probes for application to 2000 F flows

    Science.gov (United States)

    Lagen, Nicholas T.; Seiner, John M.

    1990-01-01

    The development of water cooled supersonic probes used to study high temperature jet plumes is addressed. These probes are: total pressure, static pressure, and total temperature. The motivation for these experiments is the determination of high temperature supersonic jet mean flow properties. A 3.54 inch exit diameter water cooled nozzle was used in the tests. It is designed for exit Mach 2 at 2000 F exit total temperature. Tests were conducted using water cooled probes capable of operating in Mach 2 flow, up to 2000 F total temperature. Of the two designs tested, an annular cooling method was chosen as superior. Data at the jet exit planes, and along the jet centerline, were obtained for total temperatures of 900 F, 1500 F, and 2000 F, for each of the probes. The data obtained from the total and static pressure probes are consistent with prior low temperature results. However, the data obtained from the total temperature probe was affected by the water coolant. The total temperature probe was tested up to 2000 F with, and without, the cooling system turned on to better understand the heat transfer process at the thermocouple bead. The rate of heat transfer across the thermocouple bead was greater when the coolant was turned on than when the coolant was turned off. This accounted for the lower temperature measurement by the cooled probe. The velocity and Mach number at the exit plane and centerline locations were determined from the Rayleigh-Pitot tube formula.

  12. The effect of molybdenum addition on SCC susceptibility of stainless steels in oxygenated high temperature water

    International Nuclear Information System (INIS)

    Akashi, Masatsune; Kawamoto, Teruaki

    1978-01-01

    The effect of molybdenum addition on the SCC susceptibility of sensitized stainless steel in oxygenated high temperature water has been studied through the creviced bent beam SCC test (CBB test) and A262E intergranular corrosion test. The molybdenum addition improved the SCC susceptibility of sensitized stainless steels in oxygenated high temperature water not only by delaying the sensitization at lower temperatures but also by increasing the material resistance to the SCC under a given degree of sensitization. These laboratory test results reveal that the molybdenum addition is quite beneficial for improving the SCC susceptibility of stainless steel pipe weld joints in boiling water reactor environment. (auth.)

  13. Influence of ambient temperatures on performance of a CO2 heat pump water heating system

    International Nuclear Information System (INIS)

    Yokoyama, Ryohei; Shimizu, Takeshi; Ito, Koichi; Takemura, Kazuhisa

    2007-01-01

    In residential applications, an air-to-water CO 2 heat pump is used in combination with a domestic hot water storage tank, and the performance of this system is affected significantly not only by instantaneous ambient air and city water temperatures but also by hourly changes of domestic hot water consumption and temperature distribution in the storage tank. In this paper, the performance of a CO 2 heat pump water heating system is analyzed by numerical simulation. A simulation model is created based on thermodynamic equations, and the values of model parameters are estimated based on measured data for existing devices. The calculated performance is compared with the measured one, and the simulation model is validated. The system performance is clarified in consideration of seasonal changes of ambient air and city water temperatures

  14. Salinity and water temperature data from the Coastal Waters of Washington/Oregon from 01 March 2001 to 31 December 2001 (NODC Accession 0001142)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity and water temperature data were collected using conductivity sensor and temperature probe in the Coastal Waters of Washington/Orgen from March 1, 2001 to...

  15. Validation of turbulence models for LMFBR outlet plenum flows

    International Nuclear Information System (INIS)

    Chen, Y.B.; Golay, M.W.

    1977-01-01

    Small scale experiments involving water flows are used to provide mean flow and turbulence field data for LMFBR outlet plenum flows. Measurements are performed at Reynolds number (Re) values of 33000 and 70000 in a 1/15 - scale FFTF geometry and at Re = 35000 in a 3/80-scale CRBR geometry. The experimental behavior is predicted using two different two-equation turbulence model computer programs, TEACH-T and VARR-II. It is found that the qualitative nature of the flow field within the plenum depends strongly upon the distribution of the mean inlet flow field, importantly also upon the degree of inlet turbulence, and also upon the turbulent momentum exchange model used in the calculations. In the FFTF geometry, the TEACH-T predictions agree well with the experiments. 7 refs

  16. A hydrologic regression sediment-yield model for two ungaged watershed outlet stations in Africa

    International Nuclear Information System (INIS)

    Moussa, O.M.; Smith, S.E.; Shrestha, R.L.

    1991-01-01

    A hydrologic regression sediment-yield model was established to determine the relationship between water discharge and suspended sediment discharge at the Blue Nile and the Atbara River outlet stations during the flood season. The model consisted of two main submodels: (1) a suspended sediment discharge model, which was used to determine suspended sediment discharge for each basin outlet; and (2) a sediment rating model, which related water discharge and suspended sediment discharge for each outlet station. Due to the absence of suspended sediment concentration measurements at or near the outlet stations, a minimum norm solution, which is based on the minimization of the unknowns rather than the residuals, was used to determine the suspended sediment discharges at the stations. In addition, the sediment rating submodel was regressed by using an observation equations procedure. Verification analyses on the model were carried out and the mean percentage errors were found to be +12.59 and -12.39, respectively, for the Blue Nile and Atbara. The hydrologic regression model was found to be most sensitive to the relative weight matrix, moderately sensitive to the mean water discharge ratio, and slightly sensitive to the concentration variation along the River Nile's course

  17. Ice-ocean interaction and calving front morphology at two west Greenland tidewater outlet glaciers

    Science.gov (United States)

    Chauché, N.; Hubbard, A.; Gascard, J.-C.; Box, J. E.; Bates, R.; Koppes, M.; Sole, A.; Christoffersen, P.; Patton, H.

    2014-08-01

    Warm, subtropical-originating Atlantic water (AW) has been identified as a primary driver of mass loss across the marine sectors of the Greenland Ice Sheet (GrIS), yet the specific processes by which this water mass interacts with and erodes the calving front of tidewater glaciers is frequently modelled and much speculated upon but remains largely unobserved. We present a suite of fjord salinity, temperature, turbidity versus depth casts along with glacial runoff estimation from Rink and Store glaciers, two major marine outlets draining the western sector of the GrIS during 2009 and 2010. We characterise the main water bodies present and interpret their interaction with their respective calving fronts. We identify two distinct processes of ice-ocean interaction which have distinct spatial and temporal footprints: (1) homogenous free convective melting which occurs across the calving front where AW is in direct contact with the ice mass, and (2) localised upwelling-driven melt by turbulent subglacial runoff mixing with fjord water which occurs at distinct injection points across the calving front. Throughout the study, AW at 2.8 ± 0.2 °C was consistently observed in contact with both glaciers below 450 m depth, yielding homogenous, free convective submarine melting up to ~200 m depth. Above this bottom layer, multiple interactions are identified, primarily controlled by the rate of subglacial fresh-water discharge which results in localised and discrete upwelling plumes. In the record melt year of 2010, the Store Glacier calving face was dominated by these runoff-driven plumes which led to a highly crenulated frontal geometry characterised by large embayments at the subglacial portals separated by headlands which are dominated by calving. Rink Glacier, which is significantly deeper than Store has a larger proportion of its submerged calving face exposed to AW, which results in a uniform, relatively flat overall frontal geometry.

  18. Measurement of water vapour transport through a porous non-hygroscopic material in a temperature gradient

    DEFF Research Database (Denmark)

    Hansen, Thor; Padfield, Tim; Hansen, Kurt Kielsgaard

    2014-01-01

    This was an experiment to identify the driving potential for water vapour diffusion through porous materials in a temperature gradient. The specimen of mineral fibre insulation was placed between a space with controlled temperature and relative humidity and a space with a controlled, higher...... temperature, and a measured but not controlled relative humidity (RH). This assembly was allowed to reach equilibrium with no vapour movement between the spaces, as tested by a constant RH on each side and by zero flux of water vapour measured in the cold side chamber. The RH and temperature values were...

  19. Corrosion behaviour of construction materials for high temperature water electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey

    2010-01-01

    proton exchange membrane (PEM) water electrolysers (HTPEMWE). All samples were exposed to anodic polarisation in 85% phosphoric acid electrolyte solution. Platinum and gold plates were tested for the valid comparison. Steady-state voltammetry was used in combination with scanning electron microscopy...

  20. Temperature-programmed desorption of water and ammonia on ...

    Indian Academy of Sciences (India)

    Unknown

    observed.4–8 Owing to the decomposition of the acid probe, TPD data are too complex to interpret for ... reaction with sulphated zirconia-type catalysts. Water has both ... rate of 20°C min–1 in a flow of moisture-free helium (40 ml min–1).

  1. Temperature-Induced, Selective Assembly of Supramolecular Colloids in Water

    NARCIS (Netherlands)

    Van Ravensteijn, Bas G.P.; Vilanova, Neus; De Feijter, Isja; Kegel, Willem K.; Voets, Ilja K.

    2017-01-01

    In this article, we report the synthesis and physical characterization of colloidal polystyrene particles that carry water-soluble supramolecular N,N′,N″,-trialkyl-benzene-1,3,5-tricarboxamides (BTAs) on their surface. These molecules are known to assemble into one-dimensional supramolecular

  2. EFFECTS OF PRESSURE AND TEMPERATURE ON ULTRAFILTRATION HOLLOW FIBER MEMBRANE IN MOBILE WATER TREATMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    ROSDIANAH RAMLI

    2016-07-01

    Full Text Available In Sabah, Malaysia, there are still high probability of limited clean water access in rural area and disaster site. Few villages had been affected in Pitas due to improper road access, thus building a water treatment plant there might not be feasible. Recently, Kundasang area had been affected by earthquake that caused water disruption to its people due to the damage in the underground pipes and water tanks. It has been known that membrane technology brought ease in making mobile water treatment system that can be transported to rural or disaster area. In this study, hollow fiber membrane used in a mobile water treatment system due to compact and ease setup. Hollow fiber membrane was fabricated into small module at 15 and 30 fibers to suit the mobile water treatment system for potable water production of at least 80 L/day per operation. The effects of transmembrane pressure (TMP and feed water temperature were investigated. It was found that permeate flux increases by more than 96% for both 15 and 30 fiber bundles with increasing pressure in the range of 0.25 to 3.0 bar but dropped when the pressure reached maximum. Lower temperature of 17 to 18˚C increase the water viscosity by 15% from normal temperature of water at 24˚C, making the permeate flux decreases. The fabricated modules effectively removed 96% turbidity of the surface water sample tested.

  3. Modelling of the evolution of ground waters in a granite system at low temperature: the Stripa ground waters, Sweden

    International Nuclear Information System (INIS)

    Grimaud, D.; Michard, G.; Beaucaire, C.

    1990-01-01

    From chemical data on the Stripa ground waters we have tried to model the evolution of the chemical composition of a ground water in a granitic system at low temperature. The existence of two end-member ground water compositions made it possible first, to test the conventional model of a geothermal system according to which an overall equilibrium between the waters and a given mineral assemblage can be defined, and then to show that such a model could be extended to low temperatures (10 o C). Conversely, if we know the mineral assemblage, the equilibration temperature and the charge of the mobile ions (in this case, Cl), the composition of the solution is entirely fixed. In our model of the Stripa ground waters, the existence of two end-member ground water compositions can be explained by an evolution from a ''kaolinite-albite-laumontite'' equilibrium to a ''prehnite-albite-laumontite'' equilibrium, the latter requiring less Al than the former. We have also emphasized the importance of the Cl ion concentrations of the ground waters, because they can be considered as indicators of the degree of reaction progress between rock and water, thus determining the degree of equilibration of the system. (author)

  4. Effects of water turbidity and different temperatures on oxidative stress in caddisfly (Stenopsyche marmorata) larvae.

    Science.gov (United States)

    Suzuki, Jumpei; Imamura, Masahiro; Nakano, Daisuke; Yamamoto, Ryosuke; Fujita, Masafumi

    2018-07-15

    Anthropogenic water turbidity derived from suspended solids (SS) is caused by reservoir sediment management practices such as drawdown flushing. Turbid water induces stress in many aquatic organisms, but the effects of turbidity on oxidative stress responses in aquatic insects have not yet been demonstrated. Here, we examined antioxidant responses, oxidative damage, and energy reserves in caddisfly (Stenopsyche marmorata) larvae exposed to turbid water (0 mg SS L -1 , 500 mg SS L -1 , and 2000 mg SS L -1 ) at different temperatures. We evaluated the combined effects of turbid water and temperature by measuring oxidative stress and using metabolic biomarkers. No turbidity level was significantly lethal to S. marmorata larvae. Moreover, there were no significant differences in antioxidant response or oxidative damage between the control and turbid water treatments at a low temperature (10 °C). However, at a high temperature (25 °C), turbid water modulated the activity of the antioxidant enzymes superoxide dismutase and catalase and the oxygen radical absorbance capacity as an indicator of the redox state of the insect larvae. Antioxidant defenses require energy, and high temperature was associated with low energy reserves, which might limit the capability of organisms to counteract reactive oxygen species. Moreover, co-exposure to turbid water and high temperature caused fluctuation of antioxidant defenses and increased the oxidative damage caused by the production of reactive oxygen species. Furthermore, the combined effect of high temperature and turbid water on antioxidant defenses and oxidative damage was larger than the individual effects. Therefore, our results demonstrate that exposure to both turbid water and high temperature generates additive and synergistic interactions causing oxidative stress in this aquatic insect species. Copyright © 2018. Published by Elsevier B.V.

  5. The temperature control and water quality regulation for steam generator secondary side hydrostatic test

    International Nuclear Information System (INIS)

    Xiao Bo; Liu Dongyong

    2014-01-01

    The secondary side hydrostatic test for the steam generator of M310 unit is to verify the pressure tightness of steam generator secondary side tube sheet and related systems. As for the importance of the steam generator, the water temperature and water quality of hydrostatic test has strict requirements. The discussion on the water temperature control and water quality regulation for the secondary loop hydrostatic test of Fuqing Unit 1 contribute greatly to the guiding work for the preparation of the steam generator pressure test for M310 unit. (authors)

  6. Glycerin Reformation in High Temperature and Pressure Water

    Science.gov (United States)

    2012-01-01

    filtration, belt filtering and flotation , among others (98, 103). The remaining material can undergo anaerobic digestion to produce methane, burned to...132–135). In that same 1933 patent, acrolein was produced from glycerin using a copper phosphate catalyst (132). Many studies have been published...carried out over a catalyst of copper and zinc oxide on an alumina support (198, 199). The high temperature F-T can accommodate some carbon dioxide

  7. Temperature-dependent photoluminescence of water-soluble quantum dots for a bioprobe

    International Nuclear Information System (INIS)

    Liu Tiancai; Huang Zhenli; Wang Haiqiao; Wang Jianhao; Li Xiuqing; Zhao Yuandi; Luo Qingming

    2006-01-01

    The photoluminescence of water-soluble CdSe/ZnS core/shell quantum dots is found to be temperature-dependent: as temperature arising from 280 K to 351 K, the photoluminescence declines with emission peak shifting towards the red at a rate of ∼0.11 nm K -1 . And the studies show that the photoluminescence of water-soluble CdSe/ZnS quantum dots with core capped by a thinner ZnS shell is more sensitive to temperature than that of ones with core capped by a thicker one. That is, with 50% decrement of the quantum yield the temperature of the former need to arise from 280 K to 295 K, while the latter requires much higher temperature (315.6 K), which means that the integrality of shell coverage is a very important factor on temperature-sensitivity to for the photoluminescence of water-soluble CdSe/ZnS quantum dots. Moreover, it is found that the water-soluble CdSe quantum dots with different core sizes, whose cores are capped by thicker ZnS shells, possess almost the same sensitivity to the temperature. All of the studies about photoluminescence temperature-dependence of water-soluble CdSe/ZnS core/shell quantum dots show an indispensable proof for their applications in life science

  8. Preliminary study of the relationship between surface and bulk water temperatures at the Dresden cooling pond

    International Nuclear Information System (INIS)

    Wesely, M.L.; Hicks, B.B.; Hess, G.D.

    1975-01-01

    Successful application of bulk aerodynamic formulae to determine the vertical sensible and latent heat fluxes above a cooling lake requires accurate estimates of water surface temperature. Because of the heat loss at the surface and partial insulation by the poorly-mixed outer skin of water in contact with the air-water interface, the surface temperature is usually 0.1 to 2.0 C less than the temperature at a depth greater than 1 cm. For engineering applications requiring estimates of the total heat dissipation capacity of a particular cooling lake, the bulk temperature of the entire mixed layer of subsurface water is more important than the surface temperature. Therefore, in order to simulate the thermal performance of a cooling pond, both the surface temperature and the bulk temperature should be estimated. In the case of cooling ponds, the total heat transfer through the uppermost layer is extremely large and the water beneath the surface is strongly mixed by circulation currents within the pond. The purpose of this report is to describe the magnitude of the temperature difference across the surface skin at the Dresden nuclear power plant cooling pond and to relate this difference to variables used in modeling the thermal performance of cooling ponds

  9. Temperature-dependent photoluminescence of water-soluble quantum dots for a bioprobe

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tiancai [Key Laboratory of Biomedical Photonics of Ministry of Education - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Huang Zhenli [Key Laboratory of Biomedical Photonics of Ministry of Education - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Wang Haiqiao [Key Laboratory of Biomedical Photonics of Ministry of Education - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Wang Jianhao [Key Laboratory of Biomedical Photonics of Ministry of Education - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Li Xiuqing [Key Laboratory of Biomedical Photonics of Ministry of Education - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Zhao Yuandi [Key Laboratory of Biomedical Photonics of Ministry of Education - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)]. E-mail: zydi@mail.hust.edu.cn; Luo Qingming [Key Laboratory of Biomedical Photonics of Ministry of Education - Hubei Bioinformatics and Molecular Imaging Key Laboratory, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2006-02-10

    The photoluminescence of water-soluble CdSe/ZnS core/shell quantum dots is found to be temperature-dependent: as temperature arising from 280 K to 351 K, the photoluminescence declines with emission peak shifting towards the red at a rate of {approx}0.11 nm K{sup -1}. And the studies show that the photoluminescence of water-soluble CdSe/ZnS quantum dots with core capped by a thinner ZnS shell is more sensitive to temperature than that of ones with core capped by a thicker one. That is, with 50% decrement of the quantum yield the temperature of the former need to arise from 280 K to 295 K, while the latter requires much higher temperature (315.6 K), which means that the integrality of shell coverage is a very important factor on temperature-sensitivity to for the photoluminescence of water-soluble CdSe/ZnS quantum dots. Moreover, it is found that the water-soluble CdSe quantum dots with different core sizes, whose cores are capped by thicker ZnS shells, possess almost the same sensitivity to the temperature. All of the studies about photoluminescence temperature-dependence of water-soluble CdSe/ZnS core/shell quantum dots show an indispensable proof for their applications in life science.

  10. Molecular dynamics study of room temperature ionic liquids with water at mica surface

    Directory of Open Access Journals (Sweden)

    Huanhuan Zhang

    2018-04-01

    Full Text Available Water in room temperature ionic liquids (RTILs could impose significant effects on their interfacial properties at a charged surface. Although the interfaces between RTILs and mica surfaces exhibit rich microstructure, the influence of water content on such interfaces is little understood, in particular, considering the fact that RTILs are always associated with water due to their hygroscopicity. In this work, we studied how different types of RTILs and different amounts of water molecules affect the RTIL-mica interfaces, especially the water distribution at mica surfaces, using molecular dynamics (MD simulation. MD results showed that (1 there is more water and a thicker water layer adsorbed on the mica surface as the water content increases, and correspondingly the average location of K+ ions is farther from mica surface; (2 more water accumulated at the interface with the hydrophobic [Emim][TFSI] than in case of the hydrophilic [Emim][BF4] due to the respective RTIL hydrophobicity and ion size. A similar trend was also observed in the hydrogen bonds formed between water molecules. Moreover, the 2D number density map of adsorbed water revealed that the high-density areas of water seem to be related to K+ ions and silicon/aluminum atoms on mica surface. These results are of great importance to understand the effects of hydrophobicity/hydrophicility of RTIL and water on the interfacial microstructure at electrified surfaces. Keywords: Room temperature ionic liquids, Hydrophobicity/hydrophicility, Water content, Electrical double layer, Mica surface

  11. Minimizing temperature instability of heat recovery hot water system utilizing optimized thermal energy storage

    Science.gov (United States)

    Suamir, I. N.; Sukadana, I. B. P.; Arsana, M. E.

    2018-01-01

    One energy-saving technology that starts gaining attractive for hotel industry application in Indonesia is the utilization of waste heat of a central air conditioning system to heat water for domestic hot water supply system. Implementing the technology for such application at a hotel was found that hot water capacity generated from the heat recovery system could satisfy domestic hot water demand of the hotel. The gas boilers installed in order to back up the system have never been used. The hot water supply, however, was found to be instable with hot water supply temperature fluctuated ranging from 45 °C to 62 °C. The temperature fluctuations reaches 17 °C, which is considered instable and can reduce hot water usage comfort level. This research is aimed to optimize the thermal energy storage in order to minimize the temperature instability of heat recovery hot water supply system. The research is a case study approach based on cooling and hot water demands of a hotel in Jakarta-Indonesia that has applied water cooled chillers with heat recovery systems. The hotel operation with 329 guest rooms and 8 function rooms showed that hot water production in the heat recovery system completed with 5 m3 thermal energy storage (TES) could not hold the hot water supply temperature constantly. The variations of the cooling demand and hot water demands day by day were identified. It was found that there was significant mismatched of available time (hours) between cooling demand which is directly correlated to the hot water production from the heat recovery system and hot water usage. The available TES system could not store heat rejected from the condenser of the chiller during cooling demand peak time between 14.00 and 18.00 hours. The extra heat from the heat recovery system consequently increases the temperature of hot water up to 62 °C. It is about 12 K above 50 °C the requirement hot water temperature of the hotel. In contrast, the TES could not deliver proper

  12. Assessing the Effects of Water Right Purchases on Stream Temperatures and Fish Habitat

    Science.gov (United States)

    Elmore, L.; Null, S. E.

    2012-12-01

    Warm stream temperature and low flow conditions are limiting factors for native trout species in Nevada's Walker River. Water rights purchases are being considered to increase instream flow and improve habitat conditions. However, the effect of water rights purchases on stream temperatures and fish habitat have yet to be assessed. Manipulating flow conditions affect stream temperatures by altering water depth, velocity, and thermal mass. This study uses the River Modeling System (RMSv4), an hourly, physically-based hydrodynamic and water quality model, to estimate flows and stream temperatures in the Walker River. The model is developed for two wet years (2010-2011). Study results highlight reaches with cold-water habitat that is suitable for native trout species. Previous research on the Walker River has evaluated instream flow changes with water rights purchases. This study incorporates stream temperatures as a proxy for trout habitat, and thus explicitly incorporates water quality and fish habitat into decision-making regarding water rights purchases. Walker River

  13. Structure of liquid water at high pressures and temperatures

    CERN Document Server

    Eggert, J H; Loubeyre, P

    2002-01-01

    We report quantitatively accurate structure-factor and radial-distribution-function measurements of liquid water in a diamond-anvil cell (DAC) using x-ray diffraction. During the analysis of our diffraction data, we found it possible (and necessary) to also determine the density. Thus, we believe we present the first-ever diffraction-based determination of a liquid structure factor and equation of state in a DAC experiment.

  14. Surface chemistry of metals and their oxides in high temperature water

    International Nuclear Information System (INIS)

    Tomlinson, M.

    1975-01-01

    Examination of oxide and metal surfaces in water at high temperature by a broad spectrum of techniques is bringing understanding of corrosion product movement and alleviation of activity transport in CANDU-type reactor primary coolant circuits. (Author)

  15. The Effect of Water Temperature on Argulus foliaceus L. 1758 (Crustacea; Branchiura on Different Fish Species

    Directory of Open Access Journals (Sweden)

    Mustafa KOYUN

    2011-05-01

    Full Text Available Parasites belonging to Argulus genus, known as fish louse (Argulus foliaceus L. significantly affect in negative way both in natural and farming environment. In this study, the pathogenic effect of fish louse temperature on fish depending on water was investigated. In this research to estimate the effects of several factors such as water temperature, gender of the fish and the infection of fish louse were studied through Poisson regression method. As fish species, Alburnus alburnus (bleak, Carassius carassius (crucian carp and Carassius auratus (golden carp were caught periodically, starting from May during the year, and the parasites were counted. The gender and metrical measures of the examined fish were categorized separately. The degrees of water temperature of the dam were measured. Results from Poisson regression analysis showed that fish louse has harmful effect on the mentioned fish, depending on the water temperature.

  16. WATER TEMPERATURE and other data from unknown platforms on 1996-07-31 (NODC Accession 9600119)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The water depth and temperature data were collected in 1992. Exchange data containing 6,715 real-time XBT drop profiles were submitted via FTP by Ms. Marie Claire...

  17. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1931 to 1955

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1931 to 1955 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  18. Activity of water content and storage temperature on the seed-borne mycoflora of lens culinaris

    International Nuclear Information System (INIS)

    Rahim, S.; Dawar, S.

    2014-01-01

    Storage of seeds with high water content and temperatures favors the growth of mould fungi which in turn affect the germination of seeds while low temperature with low water content prevent the growth of storage fungi and help in maintaining seed viability for longer duration of time. Seed sample from Sukkur district was stored at 4 degree C and room temperature (25-30 degree C) with water content of 8, 13 and 17% for about 80 days. The fungi were isolated at 0, 20, 40, 60 and 80 days intervals. Highest infection percentage of fungi was observed at 13 and 17% water contents at room temperature after 20 days of storage. High infection percentage of storage fungi affected the germination of seeds. Aspergillus spp were the most dominant fungi. (author)

  19. RECYCLING NICKEL ELECTROPLATING RINSE WATERS BY LOW TEMPERATURE EVAPORATION AND REVERSE OSMOSIS

    Science.gov (United States)

    Low temperature evaporation and reverse osmosis systems were each evaluated (on a pilot scale) on their respective ability to process rinse water collected from a nickel electroplating operation. Each system offered advantages under specific operating conditions. The low temperat...

  20. STRATOSPHERIC TEMPERATURES AND WATER LOSS FROM MOIST GREENHOUSE ATMOSPHERES OF EARTH-LIKE PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Kasting, James F.; Kopparapu, Ravi K. [Department of Geosciences, The Pennsylvania State University, State College, PA 16801 (United States); Chen, Howard, E-mail: jfk4@psu.edu, E-mail: hwchen@bu.edu [Department of Astronomy, Boston University, 725 Commonwealth Ave., Boston, MA 02215 (United States)

    2015-11-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a moist greenhouse explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing inverse climate calculations to determine habitable zone boundaries using 1D models.

  1. Effects of Temperature on the Density of Water Based Drilling Mud ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Effects of Temperature on the Density of Water Based Drilling Mud. EBIKAPAYE ... Commons Attribution License (CCL), which permits unrestricted use, distribution, and reproduction in any .... is tapped briskly on the side until air bubbles are.

  2. STRATOSPHERIC TEMPERATURES AND WATER LOSS FROM MOIST GREENHOUSE ATMOSPHERES OF EARTH-LIKE PLANETS

    International Nuclear Information System (INIS)

    Kasting, James F.; Kopparapu, Ravi K.; Chen, Howard

    2015-01-01

    A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface temperatures, in agreement with recent 3D calculations. However, at surface temperatures above 350 K, the stratosphere warms and water vapor becomes a major upper atmospheric constituent, allowing water to be lost by photodissociation and hydrogen escape. Hence, a moist greenhouse explanation for loss of water from Venus, or some exoplanet receiving a comparable amount of stellar radiation, remains a viable hypothesis. Temperatures in the upper parts of such atmospheres are well below those estimated for a gray atmosphere, and this factor should be taken into account when performing inverse climate calculations to determine habitable zone boundaries using 1D models

  3. Interactive Effect of Air-Water Ratio and Temperature on the Air ...

    African Journals Online (AJOL)

    Windows User

    KEYWORDS: Interactive effect, air-water ratio, temperature, volatile organic compounds, removal efficiency. [Received ... The rate of mass transfer of a VOC from wastewater to the ... where ΔHo is heat of evaporation of 1 mole of component.

  4. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1912 to 1930

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1912 to 1930 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  5. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1956 to 1980

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1956 to 1980 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  6. Gulf of Maine - Water Salinity, Temperature and Sigma t (density) data from 1981 to 2005

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table contains water salinity, temperature and sigma t (density) data from 1981 to 2005 binned at 10 meter depth intervals (from 300 meters up to 0 meters) for...

  7. The nature of supply side effects on electricity prices: the impact of water temperature

    NARCIS (Netherlands)

    Boogert, Alexander; Dupont, D.Y.

    2005-01-01

    In this paper, we show that the impact of water temperatures on electricity prices observed in Europe in summer 2003 has prevailed for years. We trace its source to technological and regulatory constraints and draw lessons for modelling.

  8. Thickened water-based hydraulic fluid with reduced dependence of viscosity on temperature

    Energy Technology Data Exchange (ETDEWEB)

    Deck, C. F.

    1985-01-01

    Improved hydraulic fluids or metalworking lubricants, utilizing mixtures of water, metal lubricants, metal corrosion inhibitors, and an associative polyether thickener, have reduced dependence of the viscosity on temperature achieved by the incorporation therein of an ethoxylated polyether surfactant.

  9. Evaluation of water cooled supersonic temperature and pressure probes for application to 1366 K flows

    Science.gov (United States)

    Lagen, Nicholas; Seiner, John M.

    1990-01-01

    Water cooled supersonic probes are developed to investigate total pressure, static pressure, and total temperature in high-temperature jet plumes and thereby determine the mean flow properties. Two probe concepts, designed for operation at up to 1366 K in a Mach 2 flow, are tested on a water cooled nozzle. The two probe designs - the unsymmetric four-tube cooling configuration and the symmetric annular cooling design - take measurements at 755, 1089, and 1366 K of the three parameters. The cooled total and static pressure readings are found to agree with previous test results with uncooled configurations. The total-temperature probe, however, is affected by the introduction of water coolant, and effect which is explained by the increased heat transfer across the thermocouple-bead surface. Further investigation of the effect of coolant on the temperature probe is proposed to mitigate the effect and calculate more accurate temperatures in jet plumes.

  10. A hierarchical model of daily stream temperature using air-water temperature synchronization, autocorrelation, and time lags

    Directory of Open Access Journals (Sweden)

    Benjamin H. Letcher

    2016-02-01

    Full Text Available Water temperature is a primary driver of stream ecosystems and commonly forms the basis of stream classifications. Robust models of stream temperature are critical as the climate changes, but estimating daily stream temperature poses several important challenges. We developed a statistical model that accounts for many challenges that can make stream temperature estimation difficult. Our model identifies the yearly period when air and water temperature are synchronized, accommodates hysteresis, incorporates time lags, deals with missing data and autocorrelation and can include external drivers. In a small stream network, the model performed well (RMSE = 0.59°C, identified a clear warming trend (0.63 °C decade−1 and a widening of the synchronized period (29 d decade−1. We also carefully evaluated how missing data influenced predictions. Missing data within a year had a small effect on performance (∼0.05% average drop in RMSE with 10% fewer days with data. Missing all data for a year decreased performance (∼0.6 °C jump in RMSE, but this decrease was moderated when data were available from other streams in the network.

  11. High temperature electrochemistry related to light water reactor corrosion

    International Nuclear Information System (INIS)

    Nagy, Gabor; Kerner, Zsolt; Balog, Janos; Schiller, Robert

    2004-01-01

    The present work deals with corrosion problems related to conditions which prevail in a WWER primary circuit. We had a two-fold aim: (A) electrochemical methods were applied to characterise the hydrothermally produced oxides of the cladding material (Zr-1%Nb) of nuclear fuel elements used in Russian made power reactors of WWER type, and (B) a number of possible reference electrodes were investigated with a view to high temperature applications. (A) Test specimens made of the cladding material, Zr-1%Nb, were immersed into an autoclave, filled with an aqueous solution typical to a WWER primary circuit, and were treated for different periods of time up to 28 weeks. The electrode potentials were measured and electrochemical impedance spectra (EIS) were taken regularly both as a function of oxidation time and temperature. This rendered information on the overall kinetics of oxide growth. By combining in situ and ex situ impedance measurements, with a particular view of the temperature dependence of EIS, we concluded that the high frequency region of impedance spectra is relevant to the presence of oxide layer on the alloy. This part of the spectra was treated in terms of a parallel CPE||R ox equivalent circuit (CPE denoting constant phase element, R ox ohmic resistor). The CPE element was understood as a dispersive resistance in terms of the continuous time random walk theory by Scher and Lax. This enabled us to tell apart electrical conductance and oxide growth with a model of charge transfer and recombination within the oxide layer as rate determining steps. (B) Three types of reference electrodes were tested within the framework of the LIRES EU5 project: (i) external Ag/AgCl, (ii) Pt/Ir alloy and (iii) Pd(Pt) double polarised active electrode. The most stable of the electrodes was found to be the Pt/Ir one. The Ag/AgCl electrode showed good stability after an initial period of some days, while substantial drifts were found for the Pd(Pt) electrode. EIS spectra of the

  12. Global sensitivity analysis of water age and temperature for informing salmonid disease management

    Science.gov (United States)

    Javaheri, Amir; Babbar-Sebens, Meghna; Alexander, Julie; Bartholomew, Jerri; Hallett, Sascha

    2018-06-01

    Many rivers in the Pacific Northwest region of North America are anthropogenically manipulated via dam operations, leading to system-wide impacts on hydrodynamic conditions and aquatic communities. Understanding how dam operations alter abiotic and biotic variables is important for designing management actions. For example, in the Klamath River, dam outflows could be manipulated to alter water age and temperature to reduce risk of parasite infections in salmon by diluting or altering viability of parasite spores. However, sensitivity of water age and temperature to the riverine conditions such as bathymetry can affect outcomes from dam operations. To examine this issue in detail, we conducted a global sensitivity analysis of water age and temperature to a comprehensive set of hydraulics and meteorological parameters in the Klamath River, California, where management of salmonid disease is a high priority. We applied an analysis technique, which combined Latin-hypercube and one-at-a-time sampling methods, and included simulation runs with the hydrodynamic numerical model of the Lower Klamath. We found that flow rate and bottom roughness were the two most important parameters that influence water age. Water temperature was more sensitive to inflow temperature, air temperature, solar radiation, wind speed, flow rate, and wet bulb temperature respectively. Our results are relevant for managers because they provide a framework for predicting how water within 'high infection risk' sections of the river will respond to dam water (low infection risk) input. Moreover, these data will be useful for prioritizing the use of water age (dilution) versus temperature (spore viability) under certain contexts when considering flow manipulation as a method to reduce risk of infection and disease in Klamath River salmon.

  13. Mineralization of hormones in breeder and broiler litters at different water potentials and temperatures.

    Science.gov (United States)

    Hemmings, Sarah N J; Hartel, Peter G

    2006-01-01

    When poultry litter is landspread, steroidal hormones present in the litter may reach surface waters, where they may have undesirable biological effects. In a laboratory study, we determined the mineralization of [4-14C]-labeled 17beta-estradiol, estrone, and testosterone in breeder litter at three different water potentials (-56, -24, and -12 MPa) and temperatures (25, 35, and 45 degrees C), and in broiler litter at two different water potentials (-24 and -12 MPa) and temperatures (25 and 35 degrees C). Mineralization was similar in both litters and generally increased with increasing water content and decreasing temperature. After 23 wk at -24 MPa, an average of 27, 11, and litter was mineralized to 14CO2 at 25, 35, and 45 degrees C, respectively. In contrast, mineralization of the radiolabeled estradiol and estrone was mineralized. The minimal mineralization suggests that the litters may still be potential sources of hormones to surface and subsurface waters.

  14. Influence of aliphatic amides on the temperature of maximum density of water

    International Nuclear Information System (INIS)

    Torres, Andrés Felipe; Romero, Carmen M.

    2017-01-01

    Highlights: • The addition of amides decreases the temperature of maximum density of water suggesting a disruptive effect on water structure. • The amides in aqueous solution do not follow the Despretz equation in the concentration range considered. • The temperature shift Δθ as a function of molality is represented by a second order equation. • The Despretz constants were determined considering the dilute concentration region for each amide solution. • Solute disrupting effect of amides becomes smaller as its hydrophobic character increases. - Abstract: The influence of dissolved substances on the temperature of the maximum density of water has been studied in relation to their effect on water structure as they can change the equilibrium between structured and unstructured species of water. However, most work has been performed using salts and the studies with small organic solutes such as amides are scarce. In this work, the effect of acetamide, propionamide and butyramide on the temperature of maximum density of water was determined from density measurements using a magnetic float densimeter. Densities of aqueous solutions were measured within the temperature range from T = (275.65–278.65) K at intervals of 0.50 K in the concentration range between (0.10000 and 0.80000) mol·kg −1 . The temperature of maximum density was determined from the experimental results. The effect of the three amides is to decrease the temperature of maximum density of water and the change does not follow the Despretz equation. The results are discussed in terms of solute-water interactions and the disrupting effect of amides on water structure.

  15. Postharvest Degradation of Microalgae: Effect of Temperature and Water Activity

    OpenAIRE

    Nelson, Jacob A.

    2015-01-01

    Though usually a nuisance in swimming pools and ponds, algae has the potential to be a valuable commodity for use as food and fuel. But before algae butter and biofuel become commonplace, issues with harvesting and storing this new crop need to be overcome. Though there has been ample research into how to grow and use algae, scientists have spent little time figuring out what to do after you pull it out of the water and before you eat it (or turn it into biodiesel). Algae, like all food produ...

  16. Electrical Power Quality - What's Behind the Outlet?

    Science.gov (United States)

    Baird, William H.; Secrest, Jeffery; Padgett, Clifford

    2017-09-01

    Although we may consider the power outlets in our homes to be nearly ideal voltage sources, a variety of influences in and around the home can cause departures from the nominal 60 Hz, 110-120 V root-mean-square (rms) of the North American grid. Even without instrumentation, we can see that a large motor starting from rest can be sufficient to cause lights to dim momentarily (voltage sag). This dimming is due to the inrush current drawn by a stationary motor, which may be several times the current drawn at operating speed. We prepared a voltage monitoring system using a voltage divider, the construction details of which we omit in the interest of safety.

  17. Water and sediment temperature dynamics in shallow tidal environments: The role of the heat flux at the sediment-water interface

    Science.gov (United States)

    Pivato, M.; Carniello, L.; Gardner, J.; Silvestri, S.; Marani, M.

    2018-03-01

    In the present study, we investigate the energy flux at the sediment-water interface and the relevance of the heat exchanged between water and sediment for the water temperature dynamics in shallow coastal environments. Water and sediment temperature data collected in the Venice lagoon show that, in shallow, temperate lagoons, temperature is uniform within the water column, and enabled us to estimate the net heat flux at the sediment-water interface. We modeled this flux as the sum of a conductive component and of the solar radiation reaching the bottom, finding the latter being negligible. We developed a "point" model to describe the temperature dynamics of the sediment-water continuum driven by vertical energy transfer. We applied the model considering conditions characterized by negligible advection, obtaining satisfactory results. We found that the heat exchange between water and sediment is crucial for describing sediment temperature but plays a minor role on the water temperature.

  18. Uncertainty of Wheat Water Use: Simulated Patterns and Sensitivity to Temperature and CO2

    Science.gov (United States)

    Cammarano, Davide; Roetter, Reimund P.; Asseng, Senthold; Ewert, Frank; Wallach, Daniel; Martre, Pierre; Hatfield, Jerry L.; Jones, James W.; Rosenzweig, Cynthia E.; Ruane, Alex C.; hide

    2016-01-01

    Projected global warming and population growth will reduce future water availability for agriculture. Thus, it is essential to increase the efficiency in using water to ensure crop productivity. Quantifying crop water use (WU; i.e. actual evapotranspiration) is a critical step towards this goal. Here, sixteen wheat simulation models were used to quantify sources of model uncertainty and to estimate the relative changes and variability between models for simulated WU, water use efficiency (WUE, WU per unit of grain dry mass produced), transpiration efficiency (Teff, transpiration per kg of unit of grain yield dry mass produced), grain yield, crop transpiration and soil evaporation at increased temperatures and elevated atmospheric carbon dioxide concentrations ([CO2]). The greatest uncertainty in simulating water use, potential evapotranspiration, crop transpiration and soil evaporation was due to differences in how crop transpiration was modelled and accounted for 50 of the total variability among models. The simulation results for the sensitivity to temperature indicated that crop WU will decline with increasing temperature due to reduced growing seasons. The uncertainties in simulated crop WU, and in particularly due to uncertainties in simulating crop transpiration, were greater under conditions of increased temperatures and with high temperatures in combination with elevated atmospheric [CO2] concentrations. Hence the simulation of crop WU, and in particularly crop transpiration under higher temperature, needs to be improved and evaluated with field measurements before models can be used to simulate climate change impacts on future crop water demand.

  19. Response of chironomid species (Diptera, Chironomidae to water temperature: effects on species distribution in specific habitats

    Directory of Open Access Journals (Sweden)

    L. Marziali

    2013-09-01

    Full Text Available The response of 443 chironomid species to water temperature was analyzed, with the aim of defining their thermal optimum, tolerance limits and thermal habitat. The database included 4442 samples mainly from Italian river catchments collected from the 1950s up to date. Thermal preferences were calculated separately for larval and pupal specimens and for different habitats: high altitude and lowland lakes in the Alpine ecoregion; lowland lakes in the Mediterranean ecoregion; heavily modified water bodies; kryal, krenal, rhithral and potamal in running waters. Optimum response was calculated as mean water temperature, weighted by species abundances; tolerance as weighted standard deviation; skewness and kurtosis as 3rd and 4th moment statistics. The responses were fitted to normal uni- or plurimodal Gaussian models. Cold stenothermal species showed: i unimodal response, ii tolerance for a narrow temperature range, iii optima closed to their minimum temperature values, iv leptokurtic response. Thermophilous species showed: i optima at different temperature values, ii wider tolerance, iii optima near their maximum temperature values, iv platikurtic response, often fitting a plurimodal model. As expected, lower optima values and narrower tolerance were obtained for kryal and krenal, than for rhithral, potamal and lakes. Thermal response curves were produced for each species and were discussed according to species distribution (i.e. altitudinal range in running water and water depth in lakes, voltinism and phylogeny. Thermal optimum and tolerance limits and the definition of the thermal habitat of species can help predicting the impact of global warming on freshwater ecosystems.

  20. The role of riparian vegetation density, channel orientation and water velocity in determining river temperature dynamics

    Science.gov (United States)

    Garner, Grace; Malcolm, Iain A.; Sadler, Jonathan P.; Hannah, David M.

    2017-10-01

    A simulation experiment was used to understand the importance of riparian vegetation density, channel orientation and flow velocity for stream energy budgets and river temperature dynamics. Water temperature and meteorological observations were obtained in addition to hemispherical photographs along a ∼1 km reach of the Girnock Burn, a tributary of the Aberdeenshire Dee, Scotland. Data from nine hemispherical images (representing different uniform canopy density scenarios) were used to parameterise a deterministic net radiation model and simulate radiative fluxes. For each vegetation scenario, the effects of eight channel orientations were investigated by changing the position of north at 45° intervals in each hemispheric image. Simulated radiative fluxes and observed turbulent fluxes drove a high-resolution water temperature model of the reach. Simulations were performed under low and high water velocity scenarios. Both velocity scenarios yielded decreases in mean (≥1.6 °C) and maximum (≥3.0 °C) temperature as canopy density increased. Slow-flowing water resided longer within the reach, which enhanced heat accumulation and dissipation, and drove higher maximum and lower minimum temperatures. Intermediate levels of shade produced highly variable energy flux and water temperature dynamics depending on the channel orientation and thus the time of day when the channel was shaded. We demonstrate that in many reaches relatively sparse but strategically located vegetation could produce substantial reductions in maximum temperature and suggest that these criteria are used to inform future river management.

  1. Hiatus in global warming - example of water temperature of the Danube River at Bogojevo gauge (Serbia

    Directory of Open Access Journals (Sweden)

    Ducić Vladan

    2015-01-01

    Full Text Available The research included trends in water temperature of the Danube River at Bogojevo gauge and surface air temperature at the nearby meteorological station Sombor, as well as an analysis of the results obtained in relation to the claims of the existence of the hiatus in global air temperature increase in the period 1998-2012. In the period 1961-2013, there was a statistically significant increase in the mean annual water temperature (0.039°C/year, as well as all the average monthly values. However, with annual values for the period 1998-2013, there was a decrease. The longest periods of negative trend (27 years were recorded for January and February. A high correlation was found between the surface air temperature and water temperature for all monthly and seasonal values. In the mean annual air temperature the presence of the hiatus is not observed, but a negative trend is recorded in March (32 years, December (43 years and February (49 years. The highest correlations between water temperature and North Atlantic Oscillation (NAO, Arctic Oscillation (AO and Atlantic Multidecadal Oscillation (AMO were obtained for the NAO in January (0.60, the AMO in autumn (0.52 and the NAO in winter (0.51. For surface air temperature, the highest correlations were registered for the AMO in summer (0.49 and the NAO in winter (0.42. The results indicate the dominant role of natural factors in the decrease of winter air temperature and water temperature of the Danube. [Projekat Ministarstva nauke Republike Srbije, br. III47007

  2. Climate-induced changes in river water temperature in North Iberian Peninsula

    Science.gov (United States)

    Soto, Benedicto

    2017-06-01

    This study evaluates the effects of climate change on the thermal regime of 12 rivers in the Northern Iberian Peninsula by using a non-linear regression model that employs air temperature as the only input variable. Prediction of future air temperature was obtained from five regional climate models (RCMs) under emission scenario Special Report on Emissions Scenarios A1B. Prior to simulation of water temperature, air temperature was bias-corrected (B-C) by means of variance scaling (VS) method. This procedure allows an improvement of fit between observed and estimated air temperature for all climate models. The simulation of water temperature for the period 1990-2100 shows an increasing trend, which is higher for the period of June-August (summer) and September-November (autumn) (0.0275 and 0.0281 °C/year) than that of winter (December-February) and spring (March-May) (0.0181 and 0.0218 °C/year). In the high air temperature range, daily water temperature is projected to increase on average by 2.2-3.1 °C for 2061-2090 relative to 1961-1990. During the coldest days, the increment of water temperature would range between 1.0 and 1.7 °C. In fact, employing the numbers of days that water temperature exceeded the upper incipient lethal temperature (UILT) for brown trout (24.7 °C) has been noted that this threshold is exceeded 14.5 days per year in 2061-2090 while in 1961-1990, this values was exceeded 2.6 days per year of mean and 3.6 days per year in observation period (2000-2014).

  3. Optimizing withdrawal from drinking water reservoirs to reduce downstream temperature pollution and reservoir hypoxia.

    Science.gov (United States)

    Weber, M; Rinke, K; Hipsey, M R; Boehrer, B

    2017-07-15

    Sustainable management of drinking water reservoirs requires balancing the demands of water supply whilst minimizing environmental impact. This study numerically simulates the effect of an improved withdrawal scheme designed to alleviate the temperature pollution downstream of a reservoir. The aim was to identify an optimal withdrawal strategy such that water of a desirable discharge temperature can be supplied downstream without leading to unacceptably low oxygen concentrations within the reservoir. First, we calibrated a one-dimensional numerical model for hydrodynamics and oxygen dynamics (GLM-AED2), verifying that the model reproduced water temperatures and hypolimnetic dissolved oxygen concentrations accurately over a 5 year period. Second, the model was extended to include an adaptive withdrawal functionality, allowing for a prescribed withdrawal temperature to be found, with the potential constraint of hypolimnetic oxygen concentration. Scenario simulations on epi-/metalimnetic withdrawal demonstrate that the model is able to autonomously determine the best withdrawal height depending on the thermal structure and the hypolimnetic oxygen concentration thereby optimizing the ability to supply a desirable discharge temperature to the downstream river during summer. This new withdrawal strategy also increased the hypolimnetic raw water volume to be used for drinking water supply, but reduced the dissolved oxygen concentrations in the deep and cold water layers (hypolimnion). Implications of the results for reservoir management are discussed and the numerical model is provided for operators as a simple and efficient tool for optimizing the withdrawal strategy within different reservoir contexts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Air - water temperature relationships in the trout streams of southeastern Minnesota’s carbonate - sandstone landscape

    Science.gov (United States)

    Krider, Lori A.; Magner, Joseph A.; Perry, Jim; Vondracek, Bruce C.; Ferrington, Leonard C.

    2013-01-01

    Carbonate-sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface-water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater-fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air-water temperature relationships for 40 GWFS in southeastern Minnesota. A 40-stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R2 of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface-water dominated streams. Regression models for streams with high R2 values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater-fed systems, but will do so at a slower rate than surface-water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.

  5. Primary collector wall local temperature fluctuations in the area of water-steam phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O.; Klinga, J.; Simo, T. [Energovyzkum Ltd., Brno (Switzerland)

    1995-12-31

    A limited number of temperature sensors could be installed at the primary collector surface in the area of water - steam phase boundary. The surface temperatures as well WWER 440 steam generator process data were measured and stored for a long time and off-line evaluated. Selected results are presented in the paper. (orig.). 2 refs.

  6. Primary collector wall local temperature fluctuations in the area of water-steam phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O; Klinga, J; Simo, T [Energovyzkum Ltd., Brno (Switzerland)

    1996-12-31

    A limited number of temperature sensors could be installed at the primary collector surface in the area of water - steam phase boundary. The surface temperatures as well WWER 440 steam generator process data were measured and stored for a long time and off-line evaluated. Selected results are presented in the paper. (orig.). 2 refs.

  7. Stress-corrosion cracking of Inconel alloy 600 in high-temperature water: an update

    International Nuclear Information System (INIS)

    Bandy, R.; van Rooyen, D.

    1983-01-01

    Inconel 600 has been tested in high-temperature aqueous media (without oxygen) in several tests. Data are presented to relate failure times to periods of crack initiation and propagation. Quantitative relationships have been developed from tests in which variations were made in temperature, applied load, strain rate, water chemistry, and the condition of the test alloy

  8. Influence of maximum water temperature on occurrence of Lahontan cutthroat trout within streams

    Science.gov (United States)

    J. Dunham; R. Schroeter; B. Rieman

    2003-01-01

    We measured water temperature at 87 sites in six streams in two different years (1998 and 1999) to test for association with the occurrence of Lahontan cutthroat trout Oncorhynchus clarki henshawi. Because laboratory studies suggest that Lahontan cutthroat trout begin to show signs of acute stress at warm (>22°C) temperatures, we focused on the...

  9. Effects of whole body cryotherapy and cold water immersion on knee skin temperature

    OpenAIRE

    Costello, J. T.; Donnelly, A. E.; Karki, A.; Selfe, J.

    2014-01-01

    This study sought to a) compare and contrast the effect of 2 commonly used cryotherapy treatments, 4 min of −110°C whole body cryotherapy and 8°C cold water immersion, on knee skin temperature and b) establish whether either protocol was capable of achieving a skin temperature (

  10. Solubility of gases in water at high temperature

    International Nuclear Information System (INIS)

    Crovetto, Rosa; Fernandez Prini, R.J.; Japas, M.L.

    1981-01-01

    In the primary circuits of the PWR, it is usual to find apolar gases such as the noble gases like, nitrogen, hydrogen (deuterium) and oxygen. These gases enter into the circuit partly due to failures in the fuel elements, accidental entries of air into the system and corrosion processes and radiolisis in the coolant media. For the operation of several auxiliary systems in the primary circuit, it is important to know the solubility of these gases in the flux of the circuit and the evaluation of physicochemical processes that take place. A cell has been built that allows to carry out determinations of solubility in the range of 350 deg C and 100 Mega Pascal. Three alternative experimental techniques have been developed to determine the solubility of the gases which are compared to each other. Measures of solubility of argon in H2O and D2O have been made in a wide range of temperatures. (V.B.) [es

  11. Friction and wear studies of nuclear power plant components in pressurized high temperature water environments

    International Nuclear Information System (INIS)

    Ko, P.L.; Zbinden, M.; Taponat, M.C.; Robertson, M.F.

    1997-01-01

    The present paper is part of a series of papers aiming to present the friction and wear results of a collaborative study on nuclear power plant components tested in pressurized high temperature water. The high temperature test facilities and the methodology in presenting the kinetics and wear results are described in detail. The results of the same material combinations obtained from two very different high temperature test facilities (NRCC and EDF) are presented and discussed. (K.A.)

  12. Estimating maize water stress by standard deviation of canopy temperature in thermal imagery

    Science.gov (United States)

    A new crop water stress index using standard deviation of canopy temperature as an input was developed to monitor crop water status. In this study, thermal imagery was taken from maize under various levels of deficit irrigation treatments in different crop growing stages. The Expectation-Maximizatio...

  13. Leaf temperature of maize and crop water stress index with variable irrigation and nitrogen supply

    Science.gov (United States)

    Water scarcity due to changing climate, population growth, and economic development is a major threat to the sustainability of irrigated agriculture in the Western United States and other regions around the world. Water stress indices based on crop canopy temperature can be useful for assessing plan...

  14. A Two-Line Absorption Instrument for Scramjet Temperature and Water Vapor Concentration Measurement in HYPULSE

    Science.gov (United States)

    Tsai, C. Y.

    1998-01-01

    A three beam water vapor sensor system has been modified to provide for near simultaneous temperature measurement. The system employs a tunable diode laser to scan spectral line of water vapor. The application to measurements in a scramjet combustor environment of a shock tunnel facility is discussed. This report presents and discusses die initial calibration of the measurement system.

  15. WATER TEMPERATURE, VOLUNTARY DRINKING AND FLUID BALANCE IN DEHYDRATED TAEKWONDO ATHLETES

    Directory of Open Access Journals (Sweden)

    Saeed Khamnei

    2011-12-01

    Full Text Available Voluntary drinking is one of the major determiners of rehydration, especially as regards exercise or workout in the heat. The present study undertakes to search for the effect of voluntary intake of water with different temperatures on fluid balance in Taekwondo athletes. Six young healthy male Taekwondo athletes were dehydrated by moderate exercise in a chamber with ambient temperature at 38-40°C and relative humidity between 20-30%. On four separate days they were allowed to drink ad libitum plane water with the four temperatures of 5, 16, 26, and 58°C, after dehydration. The volume of voluntary drinking and weight change was measured; then the primary percentage of dehydration, sweat loss, fluid deficit and involuntary dehydration were calculated. Voluntary drinking of water proved to be statistically different in the presented temperatures. Water at 16°C involved the greatest intake, while fluid deficit and involuntary dehydration were the lowest. Intake of water in the 5°C trial significantly correlated with the subject's plasma osmolality change after dehydration, yet it showed no significant correlation with weight loss. In conclusion, by way of achieving more voluntary intake of water and better fluid state, recommending cool water (~16°C for athletes is in order. Unlike the publicly held view, drinking cold water (~5°C does not improve voluntary drinking and hydration status.

  16. A model to predict stream water temperature across the conterminous USA

    Science.gov (United States)

    Catalina Segura; Peter Caldwell; Ge Sun; Steve McNulty; Yang Zhang

    2014-01-01

    Stream water temperature (ts) is a critical water quality parameter for aquatic ecosystems. However, ts records are sparse or nonexistent in many river systems. In this work, we present an empirical model to predict ts at the site scale across the USA. The model, derived using data from 171 reference sites selected from the Geospatial Attributes of Gages for Evaluating...

  17. Impacts of operation of CVP regulating reservoirs on water temperature

    International Nuclear Information System (INIS)

    Vail, L.W.

    1996-01-01

    The Western Area Power Administration (Western) markets and transmits electric power throughout 15 western states. Western's Sierra Nevada Customer Service Region (Sierra Nevada Region) markets approximately 1,480 megawatts (MW) of firm power (and 100 MW of seasonal peaking capacity) from the Central Valley Project (CVP) and other sources and markets available nonfirm power from the Washoe Project. Western's mission is to sell and deliver electricity generated from CVP powerplants. The hydroelectric facilities of the CVP are operated by the Bureau of Reclamation (Reclamation). Reclamation manages and releases water in accordance with the various acts authorizing specific projects and with enabling legislation. Western's capacity and energy sales must be in conformance with the laws that govern its sale of electrical power. Further, Western's hydropower operations at each facility must comply with minimum and maximum flows and other constraints set by Reclamation, the U.S. Fish and Wildlife Service, or other agencies, acting in accord with law or policy

  18. Effect of water temperature on biofouling development in reverse osmosis membrane systems.

    Science.gov (United States)

    Farhat, N M; Vrouwenvelder, J S; Van Loosdrecht, M C M; Bucs, Sz S; Staal, M

    2016-10-15

    Understanding the factors that determine the spatial and temporal biofilm development is a key to formulate effective control strategies in reverse osmosis membrane systems for desalination and wastewater reuse. In this study, biofilm development was investigated at different water temperatures (10, 20, and 30 °C) inside a membrane fouling simulator (MFS) flow cell. The MFS studies were done at the same crossflow velocity with the same type of membrane and spacer materials, and the same feed water type and nutrient concentration, differing only in water temperature. Spatially resolved biofilm parameters such as oxygen decrease rate, biovolume, biofilm spatial distribution, thickness and composition were measured using in-situ imaging techniques. Pressure drop (PD) increase in time was used as a benchmark as to when to stop the experiments. Biofilm measurements were performed daily, and experiments were stopped once the average PD increased to 40 mbar/cm. The results of the biofouling study showed that with increasing feed water temperature (i) the biofilm activity developed faster, (ii) the pressure drop increased faster, while (iii) the biofilm thickness decreased. At an average pressure drop increase of 40 mbar/cm over the MFS for the different feed water temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high temperature feed water are more susceptible to biofouling than installations fed with low temperature feed water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. [Total pollution features of urban runoff outlet for urban river].

    Science.gov (United States)

    Luo, Hong-Bing; Luo, Lin; Huang, Gu; He, Qiang; Liu, Ping

    2009-11-01

    The urban stormwater runoff discharged to urban river, especially to rainfall source river, cannot be ignored. In this study, the Futian River watershed in Shenzhen city in a typical southern city of China is taken as the research object. In order to guide the pollution control for urban river, the eighteen rainfall events were monitored, and the total pollution features of the urban runoff outlet for this urban river were analyzed and discussed by using the process of pollutographs, the identifying to first flush, event mean concentration (EMC), etc. Results show that the concentrations of COD, SS, TN, TP and BOD5 are ten times more than the grade V of the environmental quality standards for surface water during the runoff time; the pollution caused by heavy metals (Cr, Ge, Cu, Hg and As) in runoff at a typical rainfall event is serious; the average and range of pollutant concentration at this runoff outlet in study area are evidently higher than at Shapingba in Chongqing city of China and at Silerwood in Canada, but are lower than at Shilipu in Wuhan city of China. The first flushes of COD, SS, BOD5, especially COD and SS, are evident, but the TN and TP are not. The average EMC of COD, TN, TP and BOD5 are 224.14, 571.15, 5.223, 2.04, 143.5 mg/L, respectively. To some extent, the EMC of COD is about two times of the value of the near cities, Macao and Zhuhai. The EMC of TN and TP are obviously higher than Beijing, Guangzhou and Shanghai. To compared with foreign counties, the EMC of the study area in Shenzhen is obviously much higher than the cities of Korean, USA and Canada. So the total pollution caused by the urban surface runoff in study area is serious and necessary to be treated.

  20. Predicting Impact of Climate Change on Water Temperature and Dissolved Oxygen in Tropical Rivers

    Directory of Open Access Journals (Sweden)

    Al-Amin Danladi Bello

    2017-07-01

    Full Text Available Predicting the impact of climate change and human activities on river systems is imperative for effective management of aquatic ecosystems. Unique information can be derived that is critical to the survival of aquatic species under dynamic environmental conditions. Therefore, the response of a tropical river system under climate and land-use changes from the aspects of water temperature and dissolved oxygen concentration were evaluated. Nine designed projected climate change scenarios and three future land-use scenarios were integrated into the Hydrological Simulation Program FORTRAN (HSPF model to determine the impact of climate change and land-use on water temperature and dissolved oxygen (DO concentration using basin-wide simulation of river system in Malaysia. The model performance coefficients showed a good correlation between simulated and observed streamflow, water temperature, and DO concentration in a monthly time step simulation. The Nash–Sutcliffe Efficiency for streamflow was 0.88 for the calibration period and 0.82 for validation period. For water temperature and DO concentration, data from three stations were calibrated and the Nash–Sutcliffe Efficiency for both water temperature and DO ranged from 0.53 to 0.70. The output of the calibrated model under climate change scenarios show that increased rainfall and air temperature do not affects DO concentration and water temperature as much as the condition of a decrease in rainfall and increase in air temperature. The regression model on changes in streamflow, DO concentration, and water temperature under the climate change scenarios illustrates that scenarios that produce high to moderate streamflow, produce small predicted change in water temperatures and DO concentrations compared with the scenarios that produced a low streamflow. It was observed that climate change slightly affects the relationship between water temperatures and DO concentrations in the tropical rivers that we

  1. Temperature feedback effects in a supercritical water reactor concept with multiple heat-up steps

    Energy Technology Data Exchange (ETDEWEB)

    Barragan-Martinez, A.M., E-mail: albrm29@yahoo.com [Universidad Nacional Autonoma de Mexico, Departamento de Sistemas Energeticos, Facultad de Ingenieria, Jiutepec, Mor (Mexico); Espinosa-Paredes, G.; Vazquez-Rodriguez, A., E-mail: gepe@xanum.uam.mx, E-mail: vara@xanum.uam.mx [Universidad Autonoma Metropolitana-Iztapalapa, Area de Ingenieria en Rescursos Energeticos, Col. Vicentina (Mexico); Martin-del-Campo, C.; Francois, J.L., E-mail: cecilia.martin.del.campo@gmail.com, E-mail: juan.louis.francois@gmail.com [Universidad Nacional Autonoma de Mexico, Departamento de Sistemas Energeticos, Facultad de Ingenieria, Jiutepec, Mor (Mexico)

    2014-07-01

    The Supercritical Water Cooled Reactor (SCWR) is one of the most promising and innovative designs selected by the Generation IV International Forum. One of the concepts being studied is the High Performance Light Water Reactor (HPLWR), which is the European version of the SCWR. In this paper we present the numerical analysis of the behavior of a HPLWR with temperature feedback effects. The neutronic process, the heat transfer in the fuel rod and the thermalhydraulics in the core of the HPLWR were considered in this study. The neutronic calculations were performed with HELIOS-2 and the obtained results were used to evaluate the reactivity due to fuel temperature and supercritical water density. (author)

  2. Temperature feedback effects in a supercritical water reactor concept with multiple heat-up steps

    International Nuclear Information System (INIS)

    Barragan-Martinez, A.M.; Espinosa-Paredes, G.; Vazquez-Rodriguez, A.; Martin-del-Campo, C.; Francois, J.L.

    2014-01-01

    The Supercritical Water Cooled Reactor (SCWR) is one of the most promising and innovative designs selected by the Generation IV International Forum. One of the concepts being studied is the High Performance Light Water Reactor (HPLWR), which is the European version of the SCWR. In this paper we present the numerical analysis of the behavior of a HPLWR with temperature feedback effects. The neutronic process, the heat transfer in the fuel rod and the thermalhydraulics in the core of the HPLWR were considered in this study. The neutronic calculations were performed with HELIOS-2 and the obtained results were used to evaluate the reactivity due to fuel temperature and supercritical water density. (author)

  3. CFD results for temperature dependence water cooling pump NPSH calculations - 15425

    International Nuclear Information System (INIS)

    Strongin, M.P.

    2015-01-01

    In this work the possibility to model the pump for water cooling reactors behavior in the critical situation was considered for cases when water temperature suddenly increases. In cases like this, cavitation effects may cause pump shutoff and consequently stop the reactor cooling. Centrifugal pump was modeled. The calculations demonstrate strong dependence of NPSH (net-positive-suction-head) on the water temperature on the pump inlet. The water temperature on the inlet lies between 25 and 180 C. degrees. The pump head performance curve has a step-like slope below NPSH point. Therefore, if the pressure on the pump inlet is below than NPSH, it leads to the pump shutoff. For high water temperature on the pump inlet, NPSH follows the vapor saturated pressure for given temperature with some offset. The results clearly show that in case of accidental increase of temperature in the cooling loop, special measures are needed to support the pressure on the pump inlet to prevent pump shutoff. (author)

  4. Temperature dependence of the evaporation lengthscale for water confined between two hydrophobic plates.

    Science.gov (United States)

    Djikaev, Yuri S; Ruckenstein, Eli

    2015-07-01

    Liquid water in a hydrophobic confinement is the object of high interest in physicochemical sciences. Confined between two macroscopic hydrophobic surfaces, liquid water transforms into vapor if the distance between surfaces is smaller than a critical separation, referred to as the evaporation lengthscale. To investigate the temperature dependence of the evaporation lengthscale of water confined between two hydrophobic parallel plates, we use the combination of the density functional theory (DFT) with the probabilistic hydrogen bond (PHB) model for water-water hydrogen bonding. The PHB model provides an analytic expression for the average number of hydrogen bonds per water molecule as a function of its distance to a hydrophobic surface and its curvature. Knowing this expression, one can implement the effect of hydrogen bonding between water molecules on their interaction with the hydrophobe into DFT, which is then employed to determine the distribution of water molecules between two macroscopic hydrophobic plates at various interplate distances and various temperatures. For water confined between hydrophobic plates, our results suggest the evaporation lengthscale to be of the order of several nanometers and a linearly increasing function of temperature from T=293 K to T=333 K, qualitatively consistent with previous results. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. The dynamics of Orimulsion in water with varying salinity and temperature

    International Nuclear Information System (INIS)

    Fingas, M.F.; Wang, Z.; Landriault, M.; Noonan, J.

    2002-01-01

    A study was conducted to determine the complex interaction between salinity, time and temperature when Orimulsion is spilled in a water column. Orimulsion is a surfactant-stabilized oil-in-water emulsion composed of 70 per cent bitumen and 30 per cent water. It behaves very differently from conventional fuel oils when spilled because of its composition. It behaves predictably in both salt and fresh water, but its behaviour is difficult to predict in brackish water (2 per cent salt). Temperature also has an influence on the behaviour of Orimulsion. This study focused on examining the behaviour of Orimulsion at various low temperatures (5 to 15 degrees C), and a wide range of salinity values from fresh to salt water (values ranging from 0.1 to 33 per cent). A total of 19 experiments were conducted. The objective was to determine depletion rates and characteristics of Orimulsion when it was added to a 300 L tank of water and by determining the concentration of bitumen and the particle size distribution over time. The bitumen which rose to the top of the tank was collected and weighed. Simple equations were then developed to explain and predict the concentration of bitumen in the water column as a function of time. Nomograms indicating the quantity of oil on the bottom and on the water surface were also presented. 6 refs., 4 tabs., 10 figs

  6. Investigating aftergrowth potential of polymers in drinking water – the effect of water replacement and temperature

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    The aftergrowth potential of polymers used in drinking water distribution was investigated by a batch set-up, where test pieces were incubated in biostable, inorganic nutrient amended drinking water inoculated with surface water. Biomass production was measured as ATP and followed over 16 weeks...... difference on the biomass production of no replacement of the test water, replacement once a week or every second week. Periodical water replacement could nevertheless be considered beneficial, since a substantial NVOC migration occurred within the first six weeks of incubation, which potentially could...

  7. Water temperature, body mass and fasting heat production of pacu (Piaractus mesopotamicus).

    Science.gov (United States)

    Aguilar, Fredy A A; Cruz, Thaline M P DA; Mourão, Gerson B; Cyrino, José Eurico P

    2017-01-01

    Knowledge on fasting heat production (HEf) of fish is key to develop bioenergetics models thus improving feeding management of farmed species. The core of knowledge on HEf of farmed, neotropical fish is scarce. This study assessed the effect of body mass and water temperature on standard metabolism and fasting heat production of pacu, Piaractus mesopotamicus, an omnivore, Neotropical fresh water characin important for farming and fisheries industries all through South American continent. An automated, intermittent flow respirometry system was used to measure standard metabolic rate (SMR) of pacu (17 - 1,050 g) at five water temperatures: 19, 23, 26, 29 and 33 °C. Mass specific SMR increased with increasing water temperature but decreased as function of body mass. The allometric exponent for scaling HEf was 0.788, and lied in the range recorded for all studied warm-water fish. The recorded van't Hoff factor (Q10) for pacu (2.06) shows the species low response to temperature increases. The model HEf = 0.04643×W0.7882×T1.837 allows to predict HEf (kJ d-1) from body mass (W, kg) and water temperature (T, °C), and can be used in bioenergetical models for the species.

  8. Water temperature, body mass and fasting heat production of pacu (Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    FREDY A.A. AGUILAR

    Full Text Available ABSTRACT Knowledge on fasting heat production (HEf of fish is key to develop bioenergetics models thus improving feeding management of farmed species. The core of knowledge on HEf of farmed, neotropical fish is scarce. This study assessed the effect of body mass and water temperature on standard metabolism and fasting heat production of pacu, Piaractus mesopotamicus, an omnivore, Neotropical fresh water characin important for farming and fisheries industries all through South American continent. An automated, intermittent flow respirometry system was used to measure standard metabolic rate (SMR of pacu (17 - 1,050 g at five water temperatures: 19, 23, 26, 29 and 33 °C. Mass specific SMR increased with increasing water temperature but decreased as function of body mass. The allometric exponent for scaling HEf was 0.788, and lied in the range recorded for all studied warm-water fish. The recorded van't Hoff factor (Q10 for pacu (2.06 shows the species low response to temperature increases. The model HEf = 0.04643×W0.7882×T1.837 allows to predict HEf (kJ d-1 from body mass (W, kg and water temperature (T, °C, and can be used in bioenergetical models for the species.

  9. Ambient-temperature incubation for the field detection of Escherichia coli in drinking water.

    Science.gov (United States)

    Brown, J; Stauber, C; Murphy, J L; Khan, A; Mu, T; Elliott, M; Sobsey, M D

    2011-04-01

     Escherichia coli is the pre-eminent microbiological indicator used to assess safety of drinking water globally. The cost and equipment requirements for processing samples by standard methods may limit the scale of water quality testing in technologically less developed countries and other resource-limited settings, however. We evaluate here the use of ambient-temperature incubation in detection of E. coli in drinking water samples as a potential cost-saving and convenience measure with applications in regions with high (>25°C) mean ambient temperatures.   This study includes data from three separate water quality assessments: two in Cambodia and one in the Dominican Republic. Field samples of household drinking water were processed in duplicate by membrane filtration (Cambodia), Petrifilm™ (Cambodia) or Colilert® (Dominican Republic) on selective media at both standard incubation temperature (35–37°C) and ambient temperature, using up to three dilutions and three replicates at each dilution. Matched sample sets were well correlated with 80% of samples (n = 1037) within risk-based microbial count strata (E. coli CFU 100 ml−1 counts of 1000), and a pooled coefficient of variation of 17% (95% CI 15–20%) for paired sample sets across all methods.   These results suggest that ambient-temperature incubation of E. coli in at least some settings may yield sufficiently robust data for water safety monitoring where laboratory or incubator access is limited.

  10. Effects of whole body cryotherapy and cold water immersion on knee skin temperature.

    Science.gov (United States)

    Costello, J T; Donnelly, A E; Karki, A; Selfe, J

    2014-01-01

    This study sought to (a) compare and contrast the effect of 2 commonly used cryotherapy treatments, 4 min of -110 °C whole body cryotherapy and 8 °C cold water immersion, on knee skin temperature and (b) establish whether either protocol was capable of achieving a skin temperature (cryotherapy (19.0±0.9 °C) compared to cold water immersion (20.5±0.6 °C). However, from 10 to 60 min post, the average, minimum and maximum skin temperatures were lower (p<0.05) following the cold water treatment. Finally, neither protocol achieved a skin temperature believed to be required to elicit an analgesic effect. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Some new fatigue tests in high temperature water and liquid sodium environment

    International Nuclear Information System (INIS)

    Hattori, Takahiro; Yamauchi, Takayoshi; Kanasaki, Hiroshi; Kondo, Yoshiyuki; Endo, Tadayoshi.

    1987-01-01

    To evaluate the fatigue strength of structural materials for PWR or FBR plants, fatigue test data must be obtained in an environment of simulated primary and secondary water for PWR or of high temperature liquid sodium for FBR. Generally, such tests make it necessary to prepare expensive facilities, so when large amount of fatigue data are required, it is necessary to rationalize and simplify the fatigue tests while maintaining high accuracy. At the Takasago Research Development Center, efforts to rationalize facilities and maintain accuracy in fatigue tests have been made by developing new test methods and improving conventional techniques. This paper introduces a new method of low cycle fatigue test in high temperature water, techniques for automatic measurement of crack initiation and propagation in high temperature water environment and a multiple type fatigue testing machine for high temperature liquid sodium. (author)

  12. Estimating Past Temperature Change in Antarctica Based on Ice Core Stable Water Isotope Diffusion

    Science.gov (United States)

    Kahle, E. C.; Markle, B. R.; Holme, C.; Jones, T. R.; Steig, E. J.

    2017-12-01

    The magnitude of the last glacial-interglacial transition is a key target for constraining climate sensitivity on long timescales. Ice core proxy records and general circulation models (GCMs) both provide insight on the magnitude of climate change through the last glacial-interglacial transition, but appear to provide different answers. In particular, the magnitude of the glacial-interglacial temperature change reconstructed from East Antarctic ice-core water-isotope records is greater ( 9 degrees C) than that from most GCM simulations ( 6 degrees C). A possible source of this difference is error in the linear-scaling of water isotopes to temperature. We employ a novel, nonlinear temperature-reconstruction technique using the physics of water-isotope diffusion to infer past temperature. Based on new, ice-core data from the South Pole, this diffusion technique suggests East Antarctic temperature change was smaller than previously thought. We are able to confirm this result using a simple, water-isotope fractionation model to nonlinearly reconstruct temperature change at ice core locations across Antarctica based on combined oxygen and hydrogen isotope ratios. Both methods produce a temperature change of 6 degrees C for South Pole, agreeing with GCM results for East Antarctica. Furthermore, both produce much larger changes in West Antarctica, also in agreement with GCM results and independent borehole thermometry. These results support the fidelity of GCMs in simulating last glacial maximum climate, and contradict the idea, based on previous work, that the climate sensitivity of current GCMs is too low.

  13. Investigation of water content in primary upper shield of high temperature engineering test reactor (HTTR)

    International Nuclear Information System (INIS)

    Sumita, Junya; Sawa, Kazuhiro; Mogi, Haruyoshi; Itahashi, Shuuji; Kitami, Toshiyuki; Akutu, Youichi; Fuchita, Yasuhiro; Kawaguchi, Toru; Moriya, Masahiro

    1999-09-01

    A primary upper shield of the High Temperature Engineering Test Reactor (HTTR) is composed of concrete (grout) which is packed into iron frames. The main function of the primary upper shield is to attenuate neutron and gamma ray from the core, that leads to satisfy dose equivalent rate limit of operating floor and stand-pipe room. Water content in the concrete is one of the most important things because it strongly affects neutron-shielding ability. Then, we carried out out-of-pile experiments to investigate relationship between temperature and water content in the concrete. Based on the experimental results, a hydrolysis-diffusion model was developed to investigate water release behavior from the concrete. The model showed that water content used for shielding design in the primary upper shield of the HTTR will be maintained if temperature during operating life is under 110degC. (author)

  14. High Temperature Monitoring the Height of Condensed Water in Steam Pipes

    Science.gov (United States)

    Bar-Cohen, Yoseph; Lih, Shyh-Shiuh; Badescu, Mircea; Bao, Xiaoqi; Sherrit, Stewart; Widholm, Scott; Ostlund, Patrick; Blosiu, Julian

    2011-01-01

    An in-service health monitoring system is needed for steam pipes to track through their wall the condensation of water. The system is required to measure the height of the condensed water inside the pipe while operating at temperatures that are as high as 250 deg. C. The system needs to be able to make real time measurements while accounting for the effects of cavitation and wavy water surface. For this purpose, ultrasonic wave in pulse-echo configuration was used and reflected signals were acquired and auto-correlated to remove noise from the data and determine the water height. Transmitting and receiving the waves is done by piezoelectric transducers having Curie temperature that is significantly higher than 250 deg. C. Measurements were made at temperatures as high as 250 deg. C and have shown the feasibility of the test method. This manuscript reports the results of this feasibility study.

  15. Water temperature and concentration measurements within the expanding blast wave of a high explosive

    International Nuclear Information System (INIS)

    Carney, J R; Lightstone, J M; Piecuch, S; Koch, J D

    2011-01-01

    We present an application of absorption spectroscopy to directly measure temperature and concentration histories of water vapor within the expansion of a high explosive detonation. While the approach of absorption spectroscopy is well established, the combination of a fast, near-infrared array, broadband light source, and rigid gauge allow the first application of time-resolved absorption measurements in an explosive environment. The instrument is demonstrated using pentaerythritol tetranitrate with a sampling rate of 20 kHz for 20 ms following detonation. Absorption by water vapor is measured between 1335 and 1380 nm. Water temperatures are determined by fitting experimental transmission spectra to a simulated database. Water mole fractions are deduced following the temperature assignment. The sources of uncertainty and their impact on the results are discussed. These measurements will aid the development of chemical-specific reaction models and the predictive capability in technical fields including combustion and detonation science

  16. Pre-rigor temperature and the relationship between lamb tenderisation, free water production, bound water and dry matter.

    Science.gov (United States)

    Devine, Carrick; Wells, Robyn; Lowe, Tim; Waller, John

    2014-01-01

    The M. longissimus from lambs electrically stimulated at 15 min post-mortem were removed after grading, wrapped in polythene film and held at 4 (n=6), 7 (n=6), 15 (n=6, n=8) and 35°C (n=6), until rigor mortis then aged at 15°C for 0, 4, 24 and 72 h post-rigor. Centrifuged free water increased exponentially, and bound water, dry matter and shear force decreased exponentially over time. Decreases in shear force and increases in free water were closely related (r(2)=0.52) and were unaffected by pre-rigor temperatures. © 2013.

  17. Temperature dependence of HU values for various water equivalent phantom materials

    International Nuclear Information System (INIS)

    Homolka, P.; Nowotny, R.; Gahleitner, A.

    2002-01-01

    The temperature dependence of water equivalent phantom materials used in radiotherapy and diagnostic imaging has been investigated. Samples of phantom materials based on epoxy resin, polyethylene, a polystyrene-polypropylene mixture and commercially available phantom materials (Solid Water TM , Gammex RMI and Plastic Water TM , Nuclear Associates) were scanned at temperatures from 15 to 40 deg. C and HU values determined. At a reference temperature of 20 deg. C materials optimized for CT applications give HU values close to zero while the commercial materials show an offset of 119.77 HU (Plastic Water) and 27.69 HU (Solid Water). Temperature dependence was lowest for epoxy-based materials (EPX-W: -0.23 HU deg. C -1 ; Solid Water: -0.25 HU deg. C -1 ) and highest for a polyethylene-based material (X0: -0.72 HU deg. C -1 ). A material based on a mixture of polystyrene and polypropylene (PSPP1: -0.27 HU deg. C -1 ) is comparable to epoxy-based materials and water (-0.29 HU deg. C -1 ). (author)

  18. Study on elastic-plastic fracture toughness test in high temperature water

    International Nuclear Information System (INIS)

    Miura, Yasufumi

    2016-01-01

    Structural integrity of internal components in light water reactors is important for the safety of operation and service lifetime. Fracture toughness is important parameter for structural integrity assessment of nuclear power plant. In general, fracture toughness of materials which compose the components in light water reactor is obtained with fracture toughness tests in air although some components are subjected to high temperature water because of the difficulty of fracture toughness test in high temperature water. However, the effects of high temperature water and hydrogen on fracture behavior of the structural materials in nuclear power plant such as low alloy steel, cast austenitic stainless steel, and Ni base alloy are concerned recently. In this study, elastic-plastic fracture toughness test of low alloy steel in simulated BWR water environment was studied. Fracture toughness test in high temperature water with original clip gage and normalization data reduction technique was established. The difference of fracture toughness J_Q tested in air between using elastic unload compliance method and normalization data reduction technique was also discussed. As a result, obtained value with normalization data reduction technique tended to be higher than the value with elastic unload compliance. (author)

  19. Safety analysis of a high temperature supercritical pressure light water cooled and moderated reactor

    International Nuclear Information System (INIS)

    Ishiwatari, Y.; Oka, Y.; Koshizuka, S.

    2002-01-01

    A safety analysis code for a high temperature supercritical pressure light water cooled reactor (SCLWR-H) with water rods cooled by descending flow, SPRAT-DOWN, is developed. The hottest channel, a water rod, down comer, upper and lower plenums, feed pumps, etc. are modeled as junction of nodes. Partial of the feed water flows downward from the upper dome of the reactor pressure vessel to the water rods. The accidents analyzed here are total loss of feed water flow, feed water pump seizure, and control rods ejection. All the accidents satisfy the criteria. The accident event at which the maximum cladding temperature is the highest is total loss of feedwater flow. The transients analyzed here are loss of feed water heating, inadvertent start-up of an auxiliary water supply system, partial loss of feed water flow, loss of offsite power, loss of load, and abnormal withdrawal of control rods. All the transients satisfied the criteria. The transient event for which the maximum cladding temperature is the highest is control rod withdrawal at normal operation. The behavior of loss of load transient is different from that of BWR. The power does not increase because loss of flow occurs and the density change is small. The sensitivities of the system behavior to various parameters during transients and accidents are analyzed. The parameters having strong influence are the capacity of the auxiliary water supply system, the coast down time of the main feed water pumps, and the time delay of the main feed water pumps trip. The control rod reactivity also has strong influence. (authors)

  20. Response of water temperatures and stratification to changing climate in three lakes with different morphometry

    Science.gov (United States)

    Magee, Madeline R.; Wu, Chin H.

    2017-12-01

    Water temperatures and stratification are important drivers for ecological and water quality processes within lake systems, and changes in these with increases in air temperature and changes to wind speeds may have significant ecological consequences. To properly manage these systems under changing climate, it is important to understand the effects of increasing air temperatures and wind speed changes in lakes of different depths and surface areas. In this study, we simulate three lakes that vary in depth and surface area to elucidate the effects of the observed increasing air temperatures and decreasing wind speeds on lake thermal variables (water temperature, stratification dates, strength of stratification, and surface heat fluxes) over a century (1911-2014). For all three lakes, simulations showed that epilimnetic temperatures increased, hypolimnetic temperatures decreased, the length of the stratified season increased due to earlier stratification onset and later fall overturn, stability increased, and longwave and sensible heat fluxes at the surface increased. Overall, lake depth influences the presence of stratification, Schmidt stability, and differences in surface heat flux, while lake surface area influences differences in hypolimnion temperature, hypolimnetic heating, variability of Schmidt stability, and stratification onset and fall overturn dates. Larger surface area lakes have greater wind mixing due to increased surface momentum. Climate perturbations indicate that our larger study lakes have more variability in temperature and stratification variables than the smaller lakes, and this variability increases with larger wind speeds. For all study lakes, Pearson correlations and climate perturbation scenarios indicate that wind speed has a large effect on temperature and stratification variables, sometimes greater than changes in air temperature, and wind can act to either amplify or mitigate the effect of warmer air temperatures on lake thermal

  1. Benign Strictures of the Esophagus and Gastric Outlet: Interventional Management

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hyoung; Shin, Ji Hoon; Song, Ho Young [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2010-10-15

    Benign strictures of the esophagus and gastric outlet are difficult to manage conservatively and they usually require intervention to relieve dysphagia or to treat the stricture-related complications. In this article, authors review the non-surgical options that are used to treat benign strictures of the esophagus and gastric outlet, including balloon dilation, temporary stent placement, intralesional steroid injection and incisional therapy

  2. Gastric Outlet Obstruction from Duodenal Lipoma in an Adult ...

    African Journals Online (AJOL)

    Gastric Outlet Obstruction from Duodenal Lipoma in an Adult. ... Nigerian Journal of Surgery ... Although, peptic ulcer disease remains the most common benign cause of gastric outlet obstruction (GOO), duodenal lipomas remain a rare, but possible cause of GOO and could pose a diagnostic challenge, especially in ...

  3. Ectopic pancreas causing partial gastric outlet obstruction: a case ...

    African Journals Online (AJOL)

    Ectopic pancreas causing partial gastric outlet obstruction: a case report and review of literature. ... Nigerian Journal of Surgery ... Gastric outlet obstruction resulting from ectopic pancreas in an adult is the first of its kind in our center; we, therefore, present this case to describe the challenges faced with diagnosis, treatment, ...

  4. Tobacco Retail Outlets and Vulnerable Populations in Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Michael O. Chaiton

    2013-12-01

    Full Text Available Interest has been increasing in regulating the location and number of tobacco vendors as part of a comprehensive tobacco control program. The objective of this paper is to examine the distribution of tobacco outlets in a large jurisdiction, to assess: (1 whether tobacco outlets are more likely to be located in vulnerable areas; and (2 what proportion of tobacco outlets are located close to schools. Retail locations across the Province of Ontario from Ministry of Health Promotion data were linked to 2006 Census data at the neighbourhood level. There was one tobacco retail outlet for every 1,000 people over age 15 in Ontario. Density of outlets varied by public health unit, and was associated with the number of smokers. Tobacco outlets were more likely to be located in areas that had high neighbourhood deprivation, in both rural and urban areas. Outlets were less likely to be located in areas with high immigrant populations in urban areas, with the reverse being true for rural areas. Overall, 65% of tobacco retailers were located within 500 m of a school. The sale of tobacco products is ubiquitous, however, neighbourhoods with lower socio-economic status are more likely to have easier availability of tobacco products and most retailers are located within walking distance of a school. The results suggest the importance of policies to regulate the location of tobacco retail outlets.

  5. Off-premise alcohol outlet characteristics and violence.

    Science.gov (United States)

    Snowden, Aleksandra J; Pridemore, William Alex

    2014-07-01

    There is considerable evidence of an association between alcohol outlet density and violence. Although prior research reveals the importance of specific characteristics of bars on this association and that the relationship between bar density and violence may be moderated by these characteristics, there are few similar studies of the characteristics of off-premise outlets (e.g., liquor and convenience stores). We examined whether immediate environment, business practice, staff, and patron characteristics of off-premise alcohol outlets are associated with simple and aggravated assault density. Cross-sectional design using aggregate data from 65 census block groups in a non-metropolitan college town, systematic social observation, and spatial modeling techniques. We found limited effects of immediate environment, business practice, staff, and patron characteristics on simple assault density and no effect on aggravated assault density. Only two out of 17 characteristics were associated with simple assault density (i.e., nearby library and male patrons). This is the first study to examine the association between several off-premise alcohol outlet characteristics and assault. Our findings suggest that where the off-premise outlets are located, how well the immediate environment is maintained, what types of beverages the outlets sell, who visits them, and who works there matter little in their association with violence. This suggests the importance of outlet density itself as a primary driver of any association with violence. Public policies aimed at reducing alcohol outlet density or clustering may be useful for reducing violence.

  6. Ectopic Pancreas Causing Partial Gastric Outlet Obstruction: A Case ...

    African Journals Online (AJOL)

    Ectopic pancreas is a rare cause of gastric outlet obstruction, perhaps rarer still among Africans. Although the entity is known, the diagnostic challenges are enormous, especially in the poor‑resource environment. Gastric outlet obstruction resulting from ectopic pancreas in an adult is the first of its kind in our center;.

  7. Water augmented indirectly-fired gas turbine systems and method

    Science.gov (United States)

    Bechtel, Thomas F.; Parsons, Jr., Edward J.

    1992-01-01

    An indirectly-fired gas turbine system utilizing water augmentation for increasing the net efficiency and power output of the system is described. Water injected into the compressor discharge stream evaporatively cools the air to provide a higher driving temperature difference across a high temperature air heater which is used to indirectly heat the water-containing air to a turbine inlet temperature of greater than about 1,000.degree. C. By providing a lower air heater hot side outlet temperature, heat rejection in the air heater is reduced to increase the heat recovery in the air heater and thereby increase the overall cycle efficiency.

  8. Heat transfer coefficient: Medivance Arctic Sun Temperature Management System vs. water immersion.

    Science.gov (United States)

    English, M J; Hemmerling, T M

    2008-07-01

    To improve heat transfer, the Medivance Arctic Sun Temperature Management System (Medivance, Inc., Louisville, CO, USA) features an adhesive, water-conditioned, highly conductive hydrogel pad for intimate skin contact. This study measured and compared the heat transfer coefficient (h), i.e. heat transfer efficiency, of this pad (hPAD), in a heated model and in nine volunteers' thighs; and of 10 degrees C water (hWATER) in 33 head-out immersions by 11 volunteers. Volunteer studies had ethical approval and written informed consent. Calibrated heat flux transducers measured heat flux (W m-2). Temperature gradient (DeltaT) was measured between skin and pad or water temperatures. Temperature gradient was changed through the pad's water temperature controller or by skin cooling on immersion. The heat transfer coefficient is the slope of W m-2/DeltaT: its unit is W m-2 degrees C-1. Average with (95% CI) was: model, hPAD = 110.4 (107.8-113.1), R2 = 0.99, n = 45; volunteers, hPAD = 109.8 (95.5-124.1), R2 = 0.83, n = 51; and water immersion, hWATER = 107.1 (98.1-116), R2 = 0.86, n = 94. The heat transfer coefficient for the pad was the same in the model and volunteers, and equivalent to hWATER. Therefore, for the same DeltaT and heat transfer area, the Arctic Sun's heat transfer rate would equal water immersion. This has important implications for body cooling/rewarming rates.

  9. How and Why Does Stream Water Temperature Vary at Small Spatial Scales in a Headwater Stream?

    Science.gov (United States)

    Morgan, J. C.; Gannon, J. P.; Kelleher, C.

    2017-12-01

    The temperature of stream water is controlled by climatic variables, runoff/baseflow generation, and hyporheic exchange. Hydrologic conditions such as gaining/losing reaches and sources of inflow can vary dramatically along a stream on a small spatial scale. In this work, we attempt to discern the extent that the factors of air temperature, groundwater inflow, and precipitation influence stream temperature at small spatial scales along the length of a stream. To address this question, we measured stream temperature along the perennial stream network in a 43 ha catchment with a complex land use history in Cullowhee, NC. Two water temperature sensors were placed along the stream network on opposite sides of the stream at 100-meter intervals and at several locations of interest (i.e. stream junctions). The forty total sensors recorded the temperature every 10 minutes for one month in the spring and one month in the summer. A subset of sampling locations where stream temperature was consistent or varied from one side of the stream to the other were explored with a thermal imaging camera to obtain a more detailed representation of the spatial variation in temperature at those sites. These thermal surveys were compared with descriptions of the contributing area at the sample sites in an effort to discern specific causes of differing flow paths. Preliminary results suggest that on some branches of the stream stormflow has less influence than regular hyporheic exchange, while other tributaries can change dramatically with stormflow conditions. We anticipate this work will lead to a better understanding of temperature patterns in stream water networks. A better understanding of the importance of small-scale differences in flow paths to water temperature may be able to inform watershed management decisions in the future.

  10. Alcohol Outlets and Violent Crime in Washington D.C.

    Directory of Open Access Journals (Sweden)

    Pan, William K

    2010-08-01

    Full Text Available Objective: Alcohol is more likely than any other drug to be involved in substance-related violence. In 2000 violence-related and self-directed injuries accounted for an estimated $37 billion and $33 billion in productivity losses and medical treatment, respectively. A review of emergency department data revealed violence and clinically identified trauma-related injuries have the strongest correlation among alcohol-dependent injuries. At the environmental level there is a relationship between alcohol outlet density and violent crime. A limited number of studies have examined the relationship between alcohol outlet type and the components of violent crime. The aim of this study is to examine the relationship between the aggregate components of violent crime and alcohol outlet density by type of outlet.Methods: For this study we used Washington, D.C. census tract data from the 2000 census to examine neighborhood characteristics. Alcohol outlet, violent crime, and population-level data for Washington, D.C. were drawn from various official yet publicly available sources. We developed an analytic database to examine the relationship between alcohol outlet category and four types of violent crime. After estimating spatial correlation and determining spatial dependence, we used a negative binomial regression analysis to assess the alcohol availability-violent crime association, while controlling for structural correlates of violence.Results: Independent of alternative structural correlates of violent crime, including the prevalence of weapons and illicit drugs, community-level alcohol outlet density is significantly associated with assaultive violence. Outlets were significantly related to robbery, assault, and sexual offenses. In addition, the relationship among on-premise and off-premise outlets varied across violent crime categories.Conclusion: In Washington, D.C., alcohol outlet density is significantly associated with the violent crimes. The

  11. Evaluation of stress-corrosion cracking of sensitized 304SS in low-temperature borated water

    International Nuclear Information System (INIS)

    Jones, R.H.; Johnson, A.B. Jr.; Bruemmer, S.M.

    1981-05-01

    Intergranular stress corrosion cracking has been observed in constant extension rate tests, CERT and constant load tests of 304SS tested at 32 0 C in borated water plus 15 ppM C1 - . Evidence of IGSCC was obtained in CERT tests of welded pipe samples only when the original inner diameter surface was intact and with 15 ppM C1 - added to the borated water while IGSCC occurred in a furnace sensitized pipe sample after 500 h at a constant stress of 340 MPa in borated water containing 15 ppM C1 - . These results indicate that surface features associated with weld preparation grinding contributed to the susceptibility of sensitized 304SS to IGSCC in low temperature borated water; however, the constant load test indicates that such surface defects are not necessary for IGSCC in low temperature borated water

  12. The geography of Fast Food outlets: a review.

    Science.gov (United States)

    Fraser, Lorna K; Edwards, Kimberly L; Cade, Janet; Clarke, Graham P

    2010-05-01

    The availability of food high in fat, salt and sugar through Fast Food (FF) or takeaway outlets, is implicated in the causal pathway for the obesity epidemic. This review aims to summarise this body of research and highlight areas for future work. Thirty three studies were found that had assessed the geography of these outlets. Fourteen studies showed a positive association between availability of FF outlets and increasing deprivation. Another 13 studies also included overweight or obesity data and showed conflicting results between obesity/overweight and FF outlet availability. There is some evidence that FF availability is associated with lower fruit and vegetable intake. There is potential for land use policies to have an influence on the location of new FF outlets. Further research should incorporate good quality data on FF consumption, weight and physical activity.

  13. The Geography of Fast Food Outlets: A Review

    Directory of Open Access Journals (Sweden)

    Lorna K. Fraser

    2010-05-01

    Full Text Available The availability of food high in fat, salt and sugar through Fast Food (FF or takeaway outlets, is implicated in the causal pathway for the obesity epidemic. This review aims to summarise this body of research and highlight areas for future work. Thirty three studies were found that had assessed the geography of these outlets. Fourteen studies showed a positive association between availability of FF outlets and increasing deprivation. Another 13 studies also included overweight or obesity data and showed conflicting results between obesity/overweight and FF outlet availability. There is some evidence that FF availability is associated with lower fruit and vegetable intake. There is potential for land use policies to have an influence on the location of new FF outlets. Further research should incorporate good quality data on FF consumption, weight and physical activity.

  14. Importance of Drinking Water Temperature for Heat Stressed Pregnant Ossimi Ewes During Summer of Egypt

    International Nuclear Information System (INIS)

    Habeeb, A.A.M.; EL-Tarabany, A.A.; Gad, A.E.

    2012-01-01

    The number of 45 pregnant does with the same age and average live body weight were used in the present study. The does reared under summer hot conditions where the averages of ambient temperature and relative humidity values were 35.0 degree C and 62.5% respectively during June, July and August, 2009. Pregnant does were divided randomly into three equal groups. The 1st group drinking tap water from the source of water in the farm (30±2 degree C) and served as control. The animals in the 2nd and 3rd groups drinking cool water (20±2 degree C) and cooled water (10±2 degree C), respectively, along the experimental period which started 12 weeks before expected parturition (8 hrs daily) from 10.00 to 18.00 hrs. The results showed that drinking cool water or cold water decreased the heat load of summer season on pregnant Ossimi ewes. The respiration rate and temperatures of rectal, skin and ear values decreased significantly while daily feed intake, dry matter intake and water intake values increased significantly due to treatments when compared to those drank warm water. Blood components concentrations and estradiol, progesterone and parathormone levels in ewes drank cool or cold water were significantly higher than its levels in ewes drank warm water. The opposite was found in cortisol levels

  15. Solubility of hydrogen in water in a broad temperature and pressure range

    International Nuclear Information System (INIS)

    Baranenko, V.I.; Kirov, V.S.

    1989-01-01

    In the coolant of water-water reactors, as a result of radiolytic decomposition of water and chemical additives (hydrazine and ammonia) and saturation of the make-up water of the first loop with free hydrogen in order to suppress radiolysis, 30-60 ml/kg of hydrogen is present in normal conditions. On being released from the water, it is free to accumulate in micropores of the metals, resulting in hydrogen embrittlement; gas accumulates in stagnant zones, with deterioration in heat transfer in the first loop and corresponding difficulty in the use of the reactor and the whole reactor loop. To determine the amount of free hydrogen and hydrogen dissolved in water in different elements of the first loop, it is necessary to know the limiting solubility of hydrogen in water at different temperatures and pressures, and also to have the corresponding theoretical dependences. The experimental data on the solubility of hydrogen in water are nonsystematic and do not cover the parameter ranges of modern nuclear power plants (P = 10-30 MPa, T = 260-370C). Therefore, the aim of the present work is to establish a well-founded method of calculating the limiting solubility of hydrogen in water and, on this basis, to compile tables of the limiting solubility of hydrogen in water at pressures 0.1-50 MPa and temperatures 0-370C

  16. Water solubility of synthetic pyrope at high temperature and pressure up to 12GPa

    Science.gov (United States)

    Huang, S.; Chen, J.

    2012-12-01

    Water can be incorporated into normally anhydrous minerals as OH- defects and transported into the mantle. Its existence in the mantle may affect property of minerals, such as elasticity, electrical conductivity and rheological properties. As the secondary mineral in the mantle, garnet has not been extensively studied for its water solubility and there is discrepancies among the existing experiments on the water solubility in the garnet change at pressures and temperatures. Geiger et al., 1991 investigated water content in synthetic pyrope and concluded 0.02wt% to 0.07wt% OH- substitution. Lu et al., 1997 found 198ppm water in the Dora Miara pyrope at 100Kbar and 1000°C. Withers et al., 1998 claimed that water solubility in pyrope reached 1000ppm at 5GPa and then decreased as pressure increasing; above 7GPa, no water was detected. Mookherjee et al., 2009 also explored pyrope-rich garnet, which contains water up to 0.1%wt at 5-9GPa and temperatures 1373K-1473K. Here we report a study of water solubility of synthetic single crystal pyrope at pressures 4-12GPa and temperature 1000°C. Single crystals of pyrope were synthesized using multi-anvil press and water contents in these samples were measured using FTIR. We have observed OH- peak at 3650 cm-1 along this pressure range, although Withers, 1998 reported water contents decrease to undetectable level above 7GPa. Water solubility in pyrope will be reported as a function of pressure up to 12 GPa at 1000°C.

  17. An investigation into the effects of residual water on the glass transition temperature of polylactide microspheres using modulated temperature DSC.

    Science.gov (United States)

    Passerini, N; Craig, D Q

    2001-05-18

    The objective of the study was to ascertain residual water levels in polylactide and polylactide-co-glycolide microspheres prepared using the solvent evaporation technique and to investigate the effects of that water on the glass transitional behaviour of the microspheres. Microspheres were prepared from polylactic acid (PLA) and polylactide-co-glycolide (PLGA) 50:50 and 75:25 using a standard solvent evaporation technique. The glass transition was measured as a function of drying conditions using modulated temperature DSC. The microspheres were found to contain very low levels of dichloromethane, while residual water levels of up to circa 3% w/w were noted after freeze or oven drying, these levels being higher for microspheres containing higher glycolic acid levels. The residual water was found to lower the T(g) following the Gordon-Taylor relationship. The data indicate that the microparticles may retain significant water levels following standard preparation and drying protocols and that this drying may markedly lower the T(g) of the spheres.

  18. Experiment study on thermal mixing performance of HTR-PM reactor outlet

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yangping, E-mail: zhouyp@mail.tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Collaborative Innovation Center of Advanced Nuclear Energy Technology, the Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Tsinghua University, Beijing 100084 (China); Hao, Pengfei [School of Aerospace, Tsinghua University, Beijing 100084 (China); Li, Fu; Shi, Lei [Institute of Nuclear and New Energy Technology, Collaborative Innovation Center of Advanced Nuclear Energy Technology, the Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Tsinghua University, Beijing 100084 (China); He, Feng [School of Aerospace, Tsinghua University, Beijing 100084 (China); Dong, Yujie; Zhang, Zuoyi [Institute of Nuclear and New Energy Technology, Collaborative Innovation Center of Advanced Nuclear Energy Technology, the Key Laboratory of Advanced Reactor Engineering and Safety, Ministry of Education, Tsinghua University, Beijing 100084 (China)

    2016-09-15

    A model experiment is proposed to investigate the thermal mixing performance of HTR-PM reactor outlet. The design of the test facility is introduced, which is set at a scale of 1:2.5 comparing with the design of thermal mixing structure at HTR-PM reactor outlet. The test facility using air as its flow media includes inlet pipe system, electric heaters, main mixing structure, hot gas duct, exhaust pipe system and I&C system. Experiments are conducted on the test facility and the values of thermal-fluid parameters are collected and analyzed, which include the temperature, pressure and velocity of the flow as well as the temperature of the tube wall. The analysis results show the mixing efficiency of the test facility is higher than that required by the steam generator of HTR-PM, which indicates that the thermal mixing structure of HTR-PM fulfills its design requirement.

  19. Increase of COP for heat transformer in water purification systems. Part I - Increasing heat source temperature

    International Nuclear Information System (INIS)

    Siqueiros, J.; Romero, R.J.

    2007-01-01

    The integration of a water purification system in a heat transformer allows a fraction of heat obtained by the heat transformer to be recycled, increasing the heat source temperature. Consequently, the evaporator and generator temperatures are also increased. For any operating conditions, keeping the condenser and absorber temperatures and also the heat load to the evaporator and generator, a higher value of COP is obtained when only the evaporator and generator temperatures are increased. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as the working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP ET ) and the increase in the coefficient of performance (COP) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that proposed (AHTWP) system is capable of increasing the original value of COP ET more than 120%, by recycling part of the energy from a water purification system. The proposed system allows to increase COP values from any experimental data for water purification or any other distillation system integrated to a heat transformer, regardless of the actual COP value and any working fluid-absorbent pair

  20. Effect of different water temperatures on growth of aquatic plants Salvinia natans and Ceratophyllum demersum

    Directory of Open Access Journals (Sweden)

    Khadija Kadhem Hreeb

    2016-12-01

    Full Text Available Objective: To evaluate the effect of some different water temperatures on growth of aquatic plants (Salvinia natans and Ceratophyllum demersum. Methods: The aquatic plants were brought from Shatt Al-Arab River in 2016. Equal weights of aquatic plants were aquacultured in aquaria, and were exposed to three different temperatures ( 12, 22 and 32 °C. Results: The results showed that the two plants did not show significant differences with respect to their effects on pH and electrical conductivity values. Time and temperature did not affect the values of pH and electrical conductivity. The values of dissolved oxygen was significantly influenced with variation of time and temperature, while the two plants did not have significant differences on dissolved oxygen values, nitrate ion concentration and was not significantly influenced with variation of plant species or temperature or time. Plant species and temperature significantly affected phosphate ion concentration, while the time did not significantly influence the concentration of phosphate ion. Chlorophyll a content and biomass were significantly influenced with the variation of plant species, and temperature . Conclusions: Aquatic plants has a species specific respond to temperatures change in their environment. Water plant, Ceratophyllum demersum is more tolerant to temperatures change than Salvinia natans.

  1. Daphnia magna fitness during low food supply under different water temperature and brownification scenarios

    Directory of Open Access Journals (Sweden)

    Andrea Gall

    2016-11-01

    Full Text Available Much of our current knowledge about non-limiting dietary carbon supply for herbivorous zooplankton is based on experimental evidence and typically conducted at ~1 mg C L-1 and ~20°C. Here we ask how low supply of dietary carbon affects somatic growth, reproduction, and survival of Daphnia magna and test effects of higher water temperature (+3 °C relative to ambient and brownification (3X higher than natural water color; both predicted effects of climate change during fall cooling. We predicted that even at very low carbon supply (~5µg C L-1, higher water temperature and brownification will allow D. magna to increase its fitness. Neonates (<24 h old were incubated with lake seston for 4 weeks (October-November 2013 in experimental bottles submerged in outdoor mesocosms to explore effects of warmer and darker water. Higher temperature and brownification did not significantly affect food quality, as assessed by its fatty acid composition. Daphnia exposed to both increased temperature and brownification had highest somatic growth and were the only that reproduced, and higher temperature caused the highest Daphnia survival success. These results suggest that even under low temperature and thus lower physiological activity, low food quantity is more important than its quality for D. magna fitness.

  2. Adiabatic flame temperature of sodium combustion and sodium-water reaction

    International Nuclear Information System (INIS)

    Okano, Y.; Yamaguchi, A.

    2001-01-01

    In this paper, background information of sodium fire and sodium-water reaction accidents of LMFBR (liquid metal fast breeder reactor) is mentioned at first. Next, numerical analysis method of GENESYS is described in detail. Next, adiabatic flame temperature and composition of sodium combustion are analyzed, and affect of reactant composition, such oxygen and moisture, is discussed. Finally, adiabatic reaction zone temperature and composition of sodium-water reaction are calculated, and affects of reactant composition, sodium vaporization, and pressure are stated. Chemical equilibrium calculation program for generic chemical system (GENESYS) is developed in this study for the research on adiabatic flame temperature of sodium combustion and adiabatic reaction zone temperature of sodium-water reaction. The maximum flame temperature of the sodium combustion is 1,950 K at the standard atmospheric condition, and is not affected by the existence of moisture. The main reaction product is Na 2 O (l) , and in combustion in moist air, with NaOH (g) . The maximum reaction zone temperature of the sodium-water reaction is 1,600 K, and increases with the system pressure. The main products are NaOH (g) , NaOH (l) and H2 (g) . Sodium evaporation should be considered in the cases of sodium-rich and high pressure above 10 bar

  3. Assessing the Temperature Dependence of Narrow-Band Raman Water Vapor Lidar Measurements: A Practical Approach

    Science.gov (United States)

    Whiteman, David N.; Venable, Demetrius D.; Walker, Monique; Cardirola, Martin; Sakai, Tetsu; Veselovskii, Igor

    2013-01-01

    Narrow-band detection of the Raman water vapor spectrum using the lidar technique introduces a concern over the temperature dependence of the Raman spectrum. Various groups have addressed this issue either by trying to minimize the temperature dependence to the point where it can be ignored or by correcting for whatever degree of temperature dependence exists. The traditional technique for performing either of these entails accurately measuring both the laser output wavelength and the water vapor spectral passband with combined uncertainty of approximately 0.01 nm. However, uncertainty in interference filter center wavelengths and laser output wavelengths can be this large or larger. These combined uncertainties translate into uncertainties in the magnitude of the temperature dependence of the Raman lidar water vapor measurement of 3% or more. We present here an alternate approach for accurately determining the temperature dependence of the Raman lidar water vapor measurement. This alternate approach entails acquiring sequential atmospheric profiles using the lidar while scanning the channel passband across portions of the Raman water vapor Q-branch. This scanning is accomplished either by tilt-tuning an interference filter or by scanning the output of a spectrometer. Through this process a peak in the transmitted intensity can be discerned in a manner that defines the spectral location of the channel passband with respect to the laser output wavelength to much higher accuracy than that achieved with standard laboratory techniques. Given the peak of the water vapor signal intensity curve, determined using the techniques described here, and an approximate knowledge of atmospheric temperature, the temperature dependence of a given Raman lidar profile can be determined with accuracy of 0.5% or better. A Mathematica notebook that demonstrates the calculations used here is available from the lead author.

  4. Air demand estimation in bottom outlets with the particle finite element method. Susqueda Dam case study

    Science.gov (United States)

    Salazar, Fernando; San-Mauro, Javier; Celigueta, Miguel Ángel; Oñate, Eugenio

    2017-07-01

    Dam bottom outlets play a vital role in dam operation and safety, as they allow controlling the water surface elevation below the spillway level. For partial openings, water flows under the gate lip at high velocity and drags the air downstream of the gate, which may cause damages due to cavitation and vibration. The convenience of installing air vents in dam bottom outlets is well known by practitioners. The design of this element depends basically on the maximum air flow through the air vent, which in turn is a function of the specific geometry and the boundary conditions. The intrinsic features of this phenomenon makes it hard to analyse either on site or in full scaled experimental facilities. As a consequence, empirical formulas are frequently employed, which offer a conservative estimate of the maximum air flow. In this work, the particle finite element method was used to model the air-water interaction in Susqueda Dam bottom outlet, with different gate openings. Specific enhancements of the formulation were developed to consider air-water interaction. The results were analysed as compared to the conventional design criteria and to information gathered on site during the gate operation tests. This analysis suggests that numerical modelling with the PFEM can be helpful for the design of this kind of hydraulic works.

  5. Grey water treatment in upflow anaerobic sludge blanket (UASB) reactor at different temperatures.

    Science.gov (United States)

    Elmitwalli, Tarek; Otterpohl, Ralf

    2011-01-01

    The treatment of grey water in two upflow anaerobic sludge blanket (UASB) reactors, operated at different hydraulic retention times (HRTs) and temperatures, was investigated. The first reactor (UASB-A) was operated at ambient temperature (14-25 degrees C) and HRT of 20, 12 and 8 h, while the second reactor (UASB-30) was operated at controlled temperature of 30 degrees C and HRT of 16, 10 and 6 h. The two reactors were fed with grey water from 'Flintenbreite' settlement in Luebeck, Germany. When the grey water was treated in the UASB reactor at 30 degrees C, total chemical oxygen demand (CODt) removal of 52-64% was achieved at HRT between 6 and 16 h, while at lower temperature lower removal (31-41%) was obtained at HRT between 8 and 20 h. Total nitrogen and phosphorous removal in the UASB reactors were limited (22-36 and 10-24%, respectively) at all operational conditions. The results showed that at increasing temperature or decreasing HRT of the reactors, maximum specific methanogenic activity of the sludge in the reactors improved. As the UASB reactor showed a significantly higher COD removal (31-64%) than the septic tank (11-14%) even at low temperature, it is recommended to use UASB reactor instead of septic tank (the most common system) for grey water pre-treatment. Based on the achieved results and due to high peak flow factor, a HRT between 8 and 12 h can be considered the suitable HRT for the UASB reactor treating grey water at temperature 20-30 degrees C, while a HRT of 12-24 h can be applied at temperature lower than 20 degrees C.

  6. Canopy storage capacity and wettability of leaves and needles: The effect of water temperature changes

    Science.gov (United States)

    Klamerus-Iwan, Anna; Błońska, Ewa

    2018-04-01

    The canopy storage capacity (S) is a major component of the surface water balance. We analysed the relationship between the tree canopy water storage capacity and leaf wettability under changing simulated rainfall temperature. We estimated the effect of the rain temperature change on the canopy storage capacity and contact angle of leave and needle surfaces based on two scenarios. Six dominant forest trees were analysed: English oak (Quercus roburL.), common beech (Fagus sylvatica L.), small-leaved lime (Tilia cordata Mill), silver fir (Abies alba), Scots pine (Pinus sylvestris L.),and Norway spruce (Picea abies L.). Twigs of these species were collected from Krynica Zdrój, that is, the Experimental Forestry unit of the University of Agriculture in Cracow (southern Poland). Experimental analyses (simulations of precipitation) were performed in a laboratory under controlled conditions. The canopy storage capacity and leaf wettability classification were determined at 12 water temperatures and a practical calculator to compute changes of S and contact angles of droplets was developed. Among all species, an increase of the rainfall temperature by 0.7 °C decreases the contact angle between leave and needle surfaces by 2.41° and increases the canopy storage capacity by 0.74 g g-1; an increase of the rain temperature by 2.7 °C decreases the contact angle by 9.29° and increases the canopy storage capacity by 2.85 g g-1. A decreased contact angle between a water droplet and leaf surface indicates increased wettability. Thus, our results show that an increased temperature increases the leaf wettability in all examined species. The comparison of different species implies that the water temperature has the strongest effect on spruce and the weakest effect on oak. These data indicate that the rainfall temperature influences the canopy storage capacity.

  7. Low-Temperature Miscibility of Ethanol-Gasoline-Water Blends in Flex Fuel Applications

    DEFF Research Database (Denmark)

    Johansen, T.; Schramm, Jesper

    2009-01-01

    The miscibility of blends of gasoline and hydrous ethanol was investigated experimentally at - 25 degrees C and - 2 degrees C. Furthermore, the maximum water content was found for ethanol in flex fuel blends. The results strongly indicate that blends containing ethanol with a water content above...... that of the ethanol/water azeotrope (4.4% water by mass) can be used as Flex Fuel blends together with gasoline at ambient temperatures of 25 degrees C and 2 degrees C, without phase separation occurring. Additionally, it was shown that the ethanol purity requirement of ethanol-rich flex fuel blends falls...... with increasing ethanol content in the gasoline-rich flex fuel blend....

  8. Pulse radiolysis studies of liquid heavy water at temperatures up to 250 degrees C

    International Nuclear Information System (INIS)

    Stuart, C.R.; Ouellette, D.C.; Elliot, A.J.

    2002-09-01

    This report documents the rate constants and associated activation energies for the reactions of the primary radical species, e aq - , ·OD and ·D, which are formed during the radiolysis of heavy water within the temperature range 20 to 250 o C. These heavy-water data have been compared with the corresponding information for light water. These kinetic data form part of the database that is required to model the aqueous radiation chemistry that occurs within the core of the heavy water cooled and moderated CANDU reactor. (author)

  9. Photochemistry of pyrene with water at low temperature: study of atmospherical and astrochemical interest.

    Science.gov (United States)

    Guennoun, Zohra; Aupetit, Christian; Mascetti, Joëlle

    2011-03-17

    Photochemistry of a polyaromatic hydrocarbon, pyrene C(16)H(10), with water has been investigated at cryogenic temperatures. Photoprocessing of this species, performed at λ > 235 nm, in argon matrices, adsorbed onto amorphous water surfaces, and trapped in solid water, led to the formation of ketonic isomers, C(16)H(10)O, and possibly quinones. These species have been identified for the first time by infrared spectroscopy with the support of isotopic substitution experiments and DFT calculations. These oxidized pyrene-like species, of atmospherical and astrochemical interest, most likely arise from a tautomeric rearrangement of their analogous hydroxylated molecules, these latter being formed by reaction of water with pyrene cations.

  10. Pulse radiolysis studies of liquid heavy water at temperatures up to 250 degrees C

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, C.R.; Ouellette, D.C.; Elliot, A.J

    2002-09-01

    This report documents the rate constants and associated activation energies for the reactions of the primary radical species, e{sub aq}{sup -}, {center_dot}OD and {center_dot}D, which are formed during the radiolysis of heavy water within the temperature range 20 to 250 {sup o}C. These heavy-water data have been compared with the corresponding information for light water. These kinetic data form part of the database that is required to model the aqueous radiation chemistry that occurs within the core of the heavy water cooled and moderated CANDU reactor. (author)

  11. Raman scattering temperature measurements for water vapor in nonequilibrium dispersed two-phase flow

    International Nuclear Information System (INIS)

    Anastasia, C.M.; Neti, S.; Smith, W.R.; Chen, J.C.

    1982-09-01

    The objective of this investigation was to determine the feasibility of using Raman scattering as a nonintrusive technique to measure vapor temperatures in dispersed two-phase flow. The Raman system developed for this investigation is described, including alignment of optics and optimization of the photodetector for photon pulse counting. Experimentally obtained Raman spectra are presented for the following single- and two-phase samples: liquid water, atmospheric nitrogen, superheated steam, nitrogen and water droplets in a high void fraction air/water mist, and superheated water vapor in nonequilibrium dispersed flow

  12. [Effects of water stress and temperature on gas exchange and chlorophyll fluorescence of Sinocalycanthus chinensis leaves].

    Science.gov (United States)

    Ke, Shi-sheng; Jin, Ze-xin

    2008-01-01

    Sinocalycanthus chinensis is an endangered species in Sinocalycanthus, and only distributed in Zhejiang Province of China. This paper studied the photosynthetic responses of 2-year-old pot-cultured S. chinensis to different levels of water stress and temperature. The results indicated that under mild and moderate water stress, the net photosynthetic rate (Pn) of S. chinensis leaves was decreased to 92.3% and 74.3% of the control, respectively, which was mainly attributed to stomatal limitation; and under severe water stress, the Pn was decreased to 44.4% of the control, which might be mainly linked to non-stomatal limitation. The appropriate temperature for S. chinensis photosynthesis was from 20 degrees C to 28 degrees C. At 39 degrees C, the Pn, water use efficiency (WUE), and maximal photochemistry efficiency (Fv/Fm) were decreased significantly, while the dark respiration rate (Rd) and transpiration rate (Tr) were enhanced significantly. With increasing water stress and temperature, some photosynthetic parameters including light saturation point (LSP), apparent quantum yield (AQY) and maximal CO2 assimilation rate (Pmax) decreased to certain extents, while light compensation point (LCP) increased, suggesting that both severe water stress and higher temperature were the important environmental factors affecting the survival of S. chinensis.

  13. Detention Outlet Retrofit Improves the Functionality of Existing ...

    Science.gov (United States)

    Journal Article Provide a stormwater management device for States and watershed management organizations. By discharging excess stormwater runoff at rates that more frequently exceed the critical flow for stream channel erosion, conventional detention basins often contribute to the escalated levels of instability that are common in urban and suburban streams and can be detrimental to aquatic habitat and water quality, as well as adjacent property and infrastructure. However, these ubiquitous assets, valued at ca. $600,000/km2 in a representative suburban watershed in Northern Kentucky, are ideal candidates to aid in reversing such cycles of channel degradation because improving their functionality would not necessarily require property acquisition or heavy construction. The objective of this research was to develop a simple, cost-effective device that could be installed in detention basin outlets to reduce the erosive power of the relatively frequent, but otherwise erosive, storm events (e.g. ~ ≤ 2-yr recurrence) and provide a passive bypass to maintain flood control performance during infrequent storms (e.g. 100-yr recurrence). Results from a pilot installation show that the Detain H2O device can not only meet these goals, but can also contribute to reduced flashiness and prolonged baseflows in receiving streams. When scaling the strategy across a watershed, these results suggest that substantial gains in water quality and stream channel stability could b

  14. Water surface temperature profiles for the Rhine River derived from Landsat ETM+ data

    Science.gov (United States)

    Fricke, Katharina; Baschek, Björn

    2013-10-01

    Water temperature influences physical and chemical parameters of rivers and streams and is an important parameter for water quality. It is a crucial factor for the existence and the growth of animal and plant species in the river ecosystem. The aim of the research project "Remote sensing of water surface temperature" at the Federal Institute of Hydrology (BfG), Germany, is to supplement point measurements of water temperature with remote sensing methodology. The research area investigated here is the Upper and Middle Rhine River, where continuous measurements of water temperature are already available for several water quality monitoring stations. Satellite imagery is used to complement these point measurements and to generate longitudinal temperature profiles for a better systematic understanding of the changes in river temperature along its course. Several products for sea surface temperature derived from radiances in the thermal infrared are available, but for water temperature from rivers less research has been carried out. Problems arise from the characteristics of the river valley and morphology and the proximity to the riverbank. Depending on the river width, a certain spatial resolution of the satellite images is necessary to allow for an accurate identification of the river surface and the calculation of water temperature. The bands from the Landsat ETM+ sensor in the thermal infrared region offer a possibility to extract the river surface temperatures (RST) of a sufficiently wide river such as the Rhine. Additionally, problems such as cloud cover, shadowing effects, georeferencing errors, different emissivity of water and land, scattering of thermal radiation, adjacency and mixed pixel effects had to be accounted for and their effects on the radiance temperatures will be discussed. For this purpose, several temperature data sets derived from radiance and in situ measurements were com- pared. The observed radiance temperatures are strongly influenced by

  15. Eclosion rate, development and survivorship of Aedes albopictus (Skuse)(Diptera: Culicidae) under different water temperatures

    International Nuclear Information System (INIS)

    Monteiro, Laura C.C.; Souza, Jose R.B. de; Albuquerque, Cleide M.R. de

    2007-01-01

    In tropical areas, where vector insects populations are particularly numerous, temperature usually range between 25 de C and 35 deg C. Considering the importance of such temperature variation in determining mosquitoes population dynamics, in this work the developmental, eclosion and survival rates of the immature stages of Aedes albopictus (Skuse) were compared under constant 25, 30 and 35 deg C (using acclimatized chambers) and environmental (25 deg C to 29 deg C) temperatures. The hatching rate was considered as total number of larvae recovered after 24h. The development period as well as larval and pupal survival rate were evaluated daily. Eclosion rate was significantly higher under environmental temperature than under the studied constant temperatures, suggesting that temperature variation may be an eclosion-stimulating factor. The mean eclosion time increased with the temperature, ranging from 2.8 h (25 deg C) to 5.2 h (35 deg C). The larval period was greatly variable inside each group, although it did not differ significantly amongst groups (11.0 +- 4.19 days), with individuals showing longer larval stages in water at 35 deg C (12.0 +- 4.95 days) and environmental temperature (13.6 +- 5.98 days). Oppositely, survival was strongly affected by the higher temperature, where only one individual lived through to adult phase. The results suggest that population of Ae. albopictus from Recife may be adapting to increasing of environmental temperatures and that the limiting temperature to larval development is around 35 deg C. (author)

  16. Construction, calibration, and validation of the RBM10 water temperature model for the Trinity River, northern California

    Science.gov (United States)

    Jones, Edward C.; Perry, Russell W.; Risley, John C.; Som, Nicholas A.; Hetrick, Nicholas J.

    2016-03-31

    We constructed a one-dimensional daily averaged water-temperature model to simulate Trinity River temperatures for 1980–2013. The purpose of this model is to assess effects of water-management actions on water temperature and to provide water temperature inputs for a salmon population dynamics model. Simulated meteorological data, observed streamflow data, and observed water temperatures were used as model inputs to simulate a continuous 34-year time series of historical daily mean water temperature at eight locations along 112.2 river miles from Lewiston Dam near Weaverville, California, downstream to the Klamath River confluence. To demonstrate the utility of the model to inform management actions, we simulated three management alternatives to assess the effects of bypass flow augmentation in a drought year, 1994, and compared those results to the simulated historical baseline, referred to as the “No Action” alternative scenario. Augmentation flows from the Lewiston Dam bypass consist of temperature-controlled releases capable of cooling downstream water temperatures in hot times of the year, which can reduce the probability of disease outbreaks in fish populations. Outputs from the Trinity River water-temperature model were then used as inputs to an existing water-temperature model of the Klamath River to evaluate the effect of augmentation flow releases on water temperatures in the lower Klamath River. 

  17. Inland Water Temperature: An Ideal Indicator for the National Climate Assessment

    Science.gov (United States)

    Hook, S. J.; Lenters, J. D.; O'Reilly, C.; Healey, N. C.

    2014-12-01

    NASA is a significant contributor to the U.S. National Climate Assessment (NCA), which is a central component of the 2012-2022 U.S. Global Change Research Program Strategic Plan. The NCA has identified the need for indicators that provide a clear, concise way of communicating to NCA audiences about not only the status and trends of physical drivers of the climate system, but also the ecological and socioeconomic impacts, vulnerabilities, and responses to those drivers. We are using thermal infrared satellite data in conjunction with in situ measurements to produce water temperatures for all the large inland water bodies in North America for potential use as an indicator for the NCA. Recent studies have revealed significant warming of inland waters throughout the world. The observed rate of warming is - in many cases - greater than that of the ambient air temperature. These rapid, unprecedented changes in inland water temperatures have profound implications for lake hydrodynamics, productivity, and biotic communities. Scientists are just beginning to understand the global extent, regional patterns, physical mechanisms, and ecological consequences of lake warming. As part of our earlier studies we have collected thermal infrared satellite data from those satellite sensors that provide long-term and frequent spaceborne thermal infrared measurements of inland waters including ATSR, AVHRR, and MODIS and used these to examine trends in water surface temperature for approximately 100 of the largest inland water bodies in the world. We are now extending this work to generate temperature time-series of all North American inland water bodies that are sufficiently large to be studied using 1km resolution satellite data for the last 3 decades. These data are then being related to changes in the surface air temperature and compared with regional trends in water surface temperature derived from CMIP5/IPCC model simulations/projections to better predict future temperature changes

  18. Effects of air and water temperatures on resting metabolism of auklets and other diving birds.

    Science.gov (United States)

    Richman, Samantha E; Lovvorn, James R

    2011-01-01

    For small aquatic endotherms, heat loss while floating on water can be a dominant energy cost, and requires accurate estimation in energetics models for different species. We measured resting metabolic rate (RMR) in air and on water for a small diving bird, the Cassin's auklet (Ptychoramphus aleuticus), and compared these results to published data for other diving birds of diverse taxa and sizes. For 8 Cassin's auklets (~165 g), the lower critical temperature was higher on water (21 °C) than in air (16 °C). Lowest values of RMR (W kg⁻¹) averaged 19% higher on water (12.14 ± 3.14 SD) than in air (10.22 ± 1.43). At lower temperatures, RMR averaged 25% higher on water than in air, increasing with similar slope. RMR was higher on water than in air for alcids, cormorants, and small penguins but not for diving ducks, which appear exceptionally resistant to heat loss in water. Changes in RMR (W) with body mass either in air or on water were mostly linear over the 5- to 20-fold body mass ranges of alcids, diving ducks, and penguins, while cormorants showed no relationship of RMR with mass. The often large energetic effects of time spent floating on water can differ substantially among major taxa of diving birds, so that relevant estimates are critical to understanding their patterns of daily energy use.

  19. Study for the water penetration chemistry of bentonite under temperature gradation environment

    International Nuclear Information System (INIS)

    Hara, Naohiro; Imakita, Tsuyoshi

    2003-02-01

    This work have been studied for the water fluctuation in time and space in case of the ground water penetration into the unsaturated bentonite with development of the necessary test equipment. The test equipment necessary for this test, was designed on consideration of the adiabatic condition, sensors for pH, salt and water measurement. The thickness of the bentonite specimen was set to 10 cm and the temperature slope was enable to set between 80degC and 100degC at the both end of the specimen. The water for penetration was pushed by gas constant pressure up to 1 MPa. The glass electrode for pH, electric conductivity for salinity and moisture sensor for lower water content and water sensor for higher were used as the sensors. The fluctuation of salt and water in the ground water penetration test to bentonite was estimated. The sensor data were treated as parametric data, because those data could not calibrated in those high temperature and under those high bentonite swollen pressure. For another development should be needed for water sensor. (author)

  20. Potential Impacts of Climate Change on Stream Water Temperatures Across the United States

    Science.gov (United States)

    Ehsani, N.; Knouft, J.; Ficklin, D. L.

    2017-12-01

    Analyses of long-term observation data have revealed significant changes in several components of climate and the hydrological cycle over the contiguous United States during the twentieth and early twenty-first century. Mean surface air temperatures have significantly increased in most areas of the country. In addition, water temperatures are increasing in many watersheds across the United States. While there are numerous studies assessing the impact of climate change on air temperatures at regional and global scales, fewer studies have investigated the impacts of climate change on stream water temperatures. Projecting increases in water temperature are particularly important to the conservation of freshwater ecosystems. To achieve better insights into attributes regulating population and community dynamics of aquatic biota at large spatial and temporal scales, we need to establish relationships between environmental heterogeneity and critical biological processes of stream ecosystems at these scales. Increases in stream temperatures caused by the doubling of atmospheric carbon dioxide may result in a significant loss of fish habitat in the United States. Utilization of physically based hydrological-water temperature models is computationally demanding and can be onerous to many researchers who specialize in other disciplines. Using statistical techniques to analyze observational data from 1760 USGS stream temperature gages, our goal is to develop a simple yet accurate method to quantify the impacts of climate warming on stream water temperatures in a way that is practical for aquatic biologists, water and environmental management purposes, and conservation practitioners and policy-makers. Using an ensemble of five global climate models (GCMs), we estimate the potential impacts of climate change on stream temperatures within the contiguous United States based on recent trends. Stream temperatures are projected to increase across the US, but the magnitude of the

  1. A regional neural network model for predicting mean daily river water temperature

    Science.gov (United States)

    Wagner, Tyler; DeWeber, Jefferson Tyrell

    2014-01-01

    Water temperature is a fundamental property of river habitat and often a key aspect of river resource management, but measurements to characterize thermal regimes are not available for most streams and rivers. As such, we developed an artificial neural network (ANN) ensemble model to predict mean daily water temperature in 197,402 individual stream reaches during the warm season (May–October) throughout the native range of brook trout Salvelinus fontinalis in the eastern U.S. We compared four models with different groups of predictors to determine how well water temperature could be predicted by climatic, landform, and land cover attributes, and used the median prediction from an ensemble of 100 ANNs as our final prediction for each model. The final model included air temperature, landform attributes and forested land cover and predicted mean daily water temperatures with moderate accuracy as determined by root mean squared error (RMSE) at 886 training sites with data from 1980 to 2009 (RMSE = 1.91 °C). Based on validation at 96 sites (RMSE = 1.82) and separately for data from 2010 (RMSE = 1.93), a year with relatively warmer conditions, the model was able to generalize to new stream reaches and years. The most important predictors were mean daily air temperature, prior 7 day mean air temperature, and network catchment area according to sensitivity analyses. Forest land cover at both riparian and catchment extents had relatively weak but clear negative effects. Predicted daily water temperature averaged for the month of July matched expected spatial trends with cooler temperatures in headwaters and at higher elevations and latitudes. Our ANN ensemble is unique in predicting daily temperatures throughout a large region, while other regional efforts have predicted at relatively coarse time steps. The model may prove a useful tool for predicting water temperatures in sampled and unsampled rivers under current conditions and future projections of climate

  2. Reduction and Analysis of Low Temperature Shift Heterogeneous Catalyst for Water Gas Reaction in Ammonia Production

    Directory of Open Access Journals (Sweden)

    Zečević, N.

    2013-09-01

    Full Text Available In order to obtain additional quantities of hydrogen after the reforming reactions of natural gas and protect the ammonia synthesis catalyst, it is crucial to achieve and maintain maximum possible activity, selectivity and stability of the low temperature shift catalyst for conversion of water gas reaction during its lifetime. Whereas the heterogeneous catalyst comes in oxidized form, it is of the utmost importance to conduct the reduction procedure properly. The proper reduction procedure and continuous analysis of its performance would ensure the required activity, selectivity and stability throughout the catalyst’s service time. For the proper reduction procedure ofthe low temperature shift catalyst, in addition to process equipment, also necessary is a reliable and realistic system for temperature measurements, which will be effective for monitoring the exothermal temperature curves through all catalyst bed layers. For efficiency evaluation of low shift temperature catalyst reduction and its optimization, it is necessary to determine at regular time intervals the temperature approach to equilibrium and temperature profiles of individual layers by means of "S" and "die off" temperature exothermal curves. Based on the obtained data, the optimum inlet temperature could be determined, in order to maximally extend the service life of the heterogeneous catalyst as much as possible, and achieve the optimum equilibrium for conversion of the water gas. This paper presents the methodology for in situ reduction of the low temperature shift heterogeneous catalyst and the developed system for monitoring its individual layers to achieve the minimum possible content of carbon monoxide at the exit of the reactor. The developed system for temperature monitoring through heterogeneous catalyst layers provides the proper procedure for reduction and adjustment of optimum process working conditions for the catalyst by the continuous increase of reactor inlet

  3. Development of Non-Platinum Catalysts for Intermediate Temperature Water Electrolysis

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey Valerievich; Petrushina, Irina Michailovna; Bjerrum, Niels J.

    2014-01-01

    Water electrolysis is recognized as an efficient energy storage (in the form of hydrogen) supplement in renewable energy production. However, industrial alkaline water electrolyzers are rather ineffective and space requiring for a commercial use in connection with energy storage. The most effective...... modern water electrolyzers are based on polymeric proton-conducting membrane electrolytes (PEM), e.g. Nafion®, a perfluorocarbon-sulfonic acid polymer. These electrolyzers work at temperatures up to around 80 °C, and, in extreme cases, up to 130-140 °C. The most developed PEM electrolyzers...... as electrolytes for the intermediate temperature applications, such as CsHSO4, KHSO45. The most successful systems have been developed with CsH2PO4 (solid acid fuel cells (SAFCs) and Sn0.9In0.1P2O7 electrolytes6,7. While developing materials for the promising medium temperature electrolysis systems...

  4. Responses of invertebrates to temperature and water stress: A polar perspective.

    Science.gov (United States)

    Everatt, Matthew J; Convey, Pete; Bale, Jeffrey S; Worland, M Roger; Hayward, Scott A L

    2015-12-01

    As small bodied poikilothermic ectotherms, invertebrates, more so than any other animal group, are susceptible to extremes of temperature and low water availability. In few places is this more apparent than in the Arctic and Antarctic, where low temperatures predominate and water is unusable during winter and unavailable for parts of summer. Polar terrestrial invertebrates express a suite of physiological, biochemical and genomic features in response to these stressors. However, the situation is not as simple as responding to each stressor in isolation, as they are often faced in combination. We consider how polar terrestrial invertebrates manage this scenario in light of their physiology and ecology. Climate change is also leading to warmer summers in parts of the polar regions, concomitantly increasing the potential for drought. The interaction between high temperature and low water availability, and the invertebrates' response to them, are therefore also explored. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Quantitative assessment of accumulation of radionuclides in fish organism in dependence on water temperature

    International Nuclear Information System (INIS)

    Katkov, A.E.

    1980-01-01

    Eperimentally studied are the changes of levels of several indices of radionuclide metabolism in fishes in dependence on water temperature at its absorption directly from water and at introduction into the digestive tract. Presented are the coefficients of radionuclide storage by the fish tissues in the dependence on temperature (scales and fins, gills, head, intestines, skin, muscles, axial skeleton) and the coefficients of radionuclide retention in the whole fish. It is shown that the connection between the coefficient of radionuclide storage in the fish organism and water temperature is described by the logarithmic dependence. At the systematic entering of radionuclides into the digestive tract the retention coefficient of them in the organism expressed in the form of the ratio of residual quantity in the fish to the quantity in day dose is constant

  6. Temperature-dependent daily variability of precipitable water in special sensor microwave/imager observations

    Science.gov (United States)

    Gutowski, William J.; Lindemulder, Elizabeth A.; Jovaag, Kari

    1995-01-01

    We use retrievals of atmospheric precipitable water from satellite microwave observations and analyses of near-surface temperature to examine the relationship between these two fields on daily and longer time scales. The retrieval technique producing the data used here is most effective over the open ocean, so the analysis focuses on the southern hemisphere's extratropics, which have an extensive ocean surface. For both the total and the eddy precipitable water fields, there is a close correspondence between local variations in the precipitable water and near-surface temperature. The correspondence appears particularly strong for synoptic and planetary scale transient eddies. More specifically, the results support a typical modeling assumption that transient eddy moisture fields are proportional to transient eddy temperature fields under the assumption f constant relative humidity.

  7. Supply of domestic hot Water at comfortable temperatures by low-temperature district heating without risk of Legionella

    DEFF Research Database (Denmark)

    Yang, Xiaochen

    disinfection efficacy for Legionella if supplied by LTDH, and inject no additives into the water. Thus, they can be considered as feasible sterilization solutions. In terms of the DHW system design methods, in addition to ensure the safe and hygiene DHW supply, the potential DHW systems should also...... temperature for space heating but lower than LTDH. Therefore, to meet the comfort and hygiene requirements for DHW supply, supplementary heating methods should be combined. However, one obstacle to realize the LTDH/ULTDH is the concern of the violation of the comfort and hygiene requirements of DHW supply....... According to the Danish standard, the supply for DHW should be able to reach 45 °C for the kitchen use and 40 °C for other uses for comfort. Regarding to the hygiene requirements, large DHW system with DHW storage tank and circulation has to use high temperature regime to get rid of Legionella. The storage...

  8. The effect of cloud liquid water on tropospheric temperature retrievals from microwave measurements

    Directory of Open Access Journals (Sweden)

    L. Bernet

    2017-11-01

    Full Text Available Microwave radiometry is a suitable technique to measure atmospheric temperature profiles with high temporal resolution during clear sky and cloudy conditions. In this study, we included cloud models in the inversion algorithm of the microwave radiometer TEMPERA (TEMPErature RAdiometer to determine the effect of cloud liquid water on the temperature retrievals. The cloud models were built based on measurements of cloud base altitude and integrated liquid water (ILW, all performed at the aerological station (MeteoSwiss in Payerne (Switzerland. Cloud base altitudes were detected using ceilometer measurements while the ILW was measured by a HATPRO (Humidity And Temperature PROfiler radiometer. To assess the quality of the TEMPERA retrieval when clouds were considered, the resulting temperature profiles were compared to 2 years of radiosonde measurements. The TEMPERA instrument measures radiation at 12 channels in the frequency range from 51 to 57 GHz, corresponding to the left wing of the oxygen emission line complex. When the full spectral information with all the 12 frequency channels was used, we found a marked improvement in the temperature retrievals after including a cloud model. The chosen cloud model influenced the resulting temperature profile, especially for high clouds and clouds with a large amount of liquid water. Using all 12 channels, however, presented large deviations between different cases, suggesting that additional uncertainties exist in the lower, more transparent channels. Using less spectral information with the higher, more opaque channels only also improved the temperature profiles when clouds where included, but the influence of the chosen cloud model was less important. We conclude that tropospheric temperature profiles can be optimized by considering clouds in the microwave retrieval, and that the choice of the cloud model has a direct impact on the resulting temperature profile.

  9. On the development of high temperature ammonia-water hybrid absorption-compression heat pumps

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Markussen, Wiebke Brix; Reinholdt, Lars

    2015-01-01

    Ammonia-water hybrid absorption-compression heat pumps (HACHP) are a promising technology for development of ecient high temperature industrial heat pumps. Using 28 bar components HACHPs up to 100 °C are commercially available. Components developed for 50 bar and 140 bar show that these pressure...... limits may be possible to exceed if needed for actual applications. Feasible heat supply temperatures using these component limits are investigated. A feasible solution is defined as one that satisfies constraints on the COP, low and high pressure, compressor discharge temperature, vapour water content...... and volumetric heat capacity. The ammonia mass fraction and the liquid circulation ratio both influence these constraining parameters. The paper investigates feasible combinations of these parameters through the use of a numerical model. 28 bar components allow temperatures up to 111 °C, 50 bar up to 129°C...

  10. Measuring centimeter-resolution air temperature profiles above land and water using fiber-optic Distributed Temperature Sensing

    Science.gov (United States)

    Sigmund, Armin; Pfister, Lena; Olesch, Johannes; Thomas, Christoph K.

    2016-04-01

    with weak wind. In the same night temperature gradients up to 30 K m-1 were determined above the meadow. The water was up to 13 K warmer than the air in this night resulting in a sharp and strong temperature decrease at the water surface and a moderate decrease with gradients up to -9 K m-1 in the air above. The plexiglass rings caused some obvious artefacts and affected data was removed and replaced by linear interpolation. According to the uncertainty estimation performed to date, conduction between fabric and fiber increased fiber temperatures by approximately 0.005 K at 2 m height on a sunny day with weak wind. This effect was deemed negligible as it reflected less than 1 % of the total heating compared to that in the air. The maximum absolute error was approximately 0.9 K at 2 m height on the same day. Ongoing work will demonstrate potential benefits of the enhanced-resolution profiles by quantitatively comparing measured and interpolated temperature profiles with varying resolution (as well as sensible heat fluxes computed according to flux-gradient-similarity).

  11. Elevated temperature drives kelp microbiome dysbiosis, while elevated carbon dioxide induces water microbiome disruption.

    Directory of Open Access Journals (Sweden)

    Jeremiah J Minich

    Full Text Available Global climate change includes rising temperatures and increased pCO2 concentrations in the ocean, with potential deleterious impacts on marine organisms. In this case study we conducted a four-week climate change incubation experiment, and tested the independent and combined effects of increased temperature and partial pressure of carbon dioxide (pCO2, on the microbiomes of a foundation species, the giant kelp Macrocystis pyrifera, and the surrounding water column. The water and kelp microbiome responded differently to each of the climate stressors. In the water microbiome, each condition caused an increase in a distinct microbial order, whereas the kelp microbiome exhibited a reduction in the dominant kelp-associated order, Alteromondales. The water column microbiomes were most disrupted by elevated pCO2, with a 7.3 fold increase in Rhizobiales. The kelp microbiome was most influenced by elevated temperature and elevated temperature in combination with elevated pCO2. Kelp growth was negatively associated with elevated temperature, and the kelp microbiome showed a 5.3 fold increase Flavobacteriales and a 2.2 fold increase alginate degrading enzymes and sulfated polysaccharides. In contrast, kelp growth was positively associated with the combination of high temperature and high pCO2 'future conditions', with a 12.5 fold increase in Planctomycetales and 4.8 fold increase in Rhodobacteriales. Therefore, the water and kelp microbiomes acted as distinct communities, where the kelp was stabilizing the microbiome under changing pCO2 conditions, but lost control at high temperature. Under future conditions, a new equilibrium between the kelp and the microbiome was potentially reached, where the kelp grew rapidly and the commensal microbes responded to an increase in mucus production.

  12. Effect of Water Quality and Temperature on the Efficiency of Two Kinds of Hydrophilic Polymers in Soil.

    Science.gov (United States)

    Dehkordi, Davoud Khodadadi

    2018-06-01

      In this study, evaluation of two-superabsorbent effects, Super-AB-A-300 and Super-AB-A-200 in a sandy soil on the water retention capability and saturated hydraulic conductivity (Ks) at different water quality and soil temperature were done. The Super-AB-A-200 was less effective in water uptake than Super-AB-A-300. The efficiency of these polymers in water retention was negatively influenced by the water quality and temperature. The efficiency of these polymer treatments in water uptake reduced significantly (P < 0.05) with increasing soil temperature. In the control soil, the Ks stayed nearly constant with increasing soil temperature. As compared to the untreated control, the treated soil demonstrated a significant (P < 0.05) linear increase of Ks with increasing soil temperature. In the control soil, the water holding properties curve did not change with increasing soil temperature.

  13. Detection and Repair of Ligament Cracks in a 109mm Thick Superheater Outlet Header

    International Nuclear Information System (INIS)

    Day, Peter

    2006-01-01

    Conventional thermal power station boilers are constructed of drums and a series of headers which are interconnected with many hundreds of tubes. Typically feed water enters the boiler at about 250 deg C at a pressure of around 250 bar with steam outlet temperatures of 540 deg C and a pressure of 170 bar. Superheater outlet headers may be subjected to quite arduous conditions during service. Not only are they exposed to high pressure stresses but also to high thermal stresses due to varying thermal gradients through the section thickness particularly at start up and during two shift operation. The area that is exposed to the greatest thermal gradients is the narrow ligament that exists between the tube hole penetrations in the header bore. In the mid the 1980's industry wide surveys found cracking in a large percentage (25-50%) of headers after 15 years of service. Detection and sizing of ligament cracking and estimates of the rate of growth are therefore a major consideration especially in plant that is two shifted. In order to manage the risk both remote visual and ultrasonic inspection are performed during each major unit overhaul. Conclusion: Ultrasonic techniques used for this inspection need to be carefully evaluated with respect to their effectiveness. Conventional pulse echo is capable of detection but using for example a technique such as AS2207 level 1 will not show the defect size. Time of flight diffraction has shown itself to be effective in accurately sizing ligament cracking. However the complex geometry of header ligaments appears to cause a narrowing of the beam with the effect that crack tip responses can be concentrated at the centre of the ligament. Therefore great care needs to be taken during data interrogation because errors in sizing can occur. Wherever possible both 'B' and 'D' scan data should be collected. It appears that the greatest accuracy is obtained with respect to defect growth from the B scan image. With respect to the welding a

  14. Pressure and temperature fields and water released by concrete submitted to high heat fluxes

    International Nuclear Information System (INIS)

    Andrade Lima, F.R. de

    1982-01-01

    Inovations are introduced in the original program USINT considering thermal conductivity variations with the temperature. A subroutine - PLOTTI - is incorporate to the program aiming to obtain a graphic for results. The new program - USINTG - is used for calculating the field of pressure and temperature and the water released from the concrete structure during a simulation of sodium leak. The theoretical results obtained with USINTG are in good agreement with the experimental results previously obtained. (E.G.) [pt

  15. Sea-ice cover in the Nordic Seas and the sensitivity to Atlantic water temperatures

    Science.gov (United States)

    Jensen, Mari F.; Nisancioglu, Kerim H.; Spall, Michael A.

    2017-04-01

    Changes in the sea-ice cover of the Nordic Seas have been proposed to play a key role for the dramatic temperature excursions associated with the Dansgaard-Oeschger events during the last glacial. However, with its proximity to the warm Atlantic water, how a sea-ice cover can persist in the Nordic Seas is not well understood. In this study, we apply an eddy-resolving configuration of the Massachusetts Institute of Technology general circulation model with an idealized topography to study the presence of sea ice in a Nordic Seas-like domain. We assume an infinite amount of warm Atlantic water present in the south by restoring the southern area to constant temperatures. The sea-surface temperatures are restored toward cold, atmospheric temperatures, and as a result, sea ice is present in the interior of the domain. However, the sea-ice cover in the margins of the Nordic Seas, an area with a warm, cyclonic boundary current, is sensitive to the amount of heat entering the domain, i.e., the restoring temperature in the south. When the temperature of the warm, cyclonic boundary current is high, the margins are free of sea ice and heat is released to the atmosphere. We show that with a small reduction in the temperature of the incoming Atlantic water, the Nordic Seas-like domain is fully covered in sea ice. Warm water is still entering the Nordic Seas, however, this happens at depths below a cold, fresh surface layer produced by melted sea ice. Consequently, the heat release to the atmosphere is reduced along with the eddy heat fluxes. Results suggest a threshold value in the amount of heat entering the Nordic Seas before the sea-ice cover disappears in the margins. We study the sensitivity of this threshold to changes in atmospheric temperatures and vertical diffusivity.

  16. Studies of the corrosion and cracking behavior of steels in high temperature water by electrochemical techniques

    International Nuclear Information System (INIS)

    Cheng, Y.F.; Bullerwell, J.; Steward, F.R.

    2003-01-01

    Electrochemical methods were used to study the corrosion and cracking behavior of five Fe-Cr alloy steels and 304L stainless steel in high temperature water. A layer of magnetite film forms on the metal surface, which decreases the corrosion rate in high temperature water. Passivity can be achieved on A-106 B carbon steel with a small content of chromium, which cannot be passivated at room temperature. The formation rate and the stability of the passive film (magnetite film) increased with increasing Cr-content in the steels. A mechanistic model was developed to simulate the corrosion and cracking processes of steels in high temperature water. The crack growth rate on steels was calculated from the maximum current of the repassivation current curves according to the slip-oxidation model. The highest crack growth rate was found for 304L stainless steel in high temperature water. Of the four Fe-Cr alloys, the crack growth rate was lower on 0.236% Cr- and 0.33% Cr-steels than on 0.406% Cr-steel and 2.5% Cr-1% Mo steel. The crack growth rate on 0.33% Cr-steel was the smallest over the tested potential range. A higher temperature of the electrolyte led to a higher rate of electrochemical dissolution of steel and a higher susceptibility of steel to cracking, as shown by the positive increase of the electrochemical potential. An increase in Cr-content in the steel is predicted to reduce the corrosion rate of steel at high temperatures. However, this increase in Cr-content is predicted not to reduce the susceptibility of steel to cracking at high temperatures. (author)

  17. Energy Efficiency of Low-Temperature Deaeration of Makeup Water for a District Heating System

    Energy Technology Data Exchange (ETDEWEB)

    Sharapov, V. I., E-mail: vlad-sharapov2008@yandex.ru; Kudryavtseva, E. V. [Ulyanovsk State Technical University (Russian Federation)

    2016-07-15

    It is shown that the temperature of makeup water in district heating systems has a strong effect on the energy efficiency of turbines of thermal power plants. A low-temperature deaeration process that considerably improves the energy efficiency of thermal power plants is developed. The desorbing agent is the gas supplied to the burners of the boiler. The energy efficiency of the process for a typical unit of thermal power plant is assessed.

  18. Estimation of reactor pool water temperature after shutdown in JRR-3M

    International Nuclear Information System (INIS)

    Yagi, Masahiro; Sato, Mitsugu; Kakefuda, Kazuhiro

    1999-01-01

    The reactor pool water temperature increasing by the decay heat was estimated by calculation. The reactor pool water temperature was calculated by increased enthalpy that was estimated by the reactor decay heat, the heat released from the reactor biological shielding concrete, reactor pool water surface, the heat conduction from the canal and the core inlet piping. These results of calculation were compared with the past measured data. As the results of estimation, after the JRR-3M shutdown, the calculated reactor pool temperature first increased sharply. This is because the decay heat was the major contribution. And then, rate of increased reactor pool temperature decreased. This is because the ratio of heat released from reactor biological shielding concrete and core inlet piping to the decay heat increased. Besides, the calculated reactor pool water temperature agreed with the past measured data in consequence of correcting the decay heat and the released heat. The corrected coefficient k 1 of decay heat was 0.74 - 0.80. And the corrected coefficient k 2 of heat released from the reactor biological shielding concrete was 3.5 - 4.5. (author)

  19. Effect of overload on SCC growth in stainless steels in high temperature water

    International Nuclear Information System (INIS)

    Xue, He; Peng, Qunjia; Shoji, Tetsuo

    2009-01-01

    By incorporating the film slip-dissolution/oxidation model and the elastic-plastic finite element method (EPFEM), the effect of the overload on stress corrosion cracking (SCC) growth rate of stainless steel in high temperature water is discussed in this paper. Results show that SCC growth rate of a 20% cold worked 316L stainless steel in high temperature water decrease in the overload affected zone ahead of the growing crack tip. Therefore, a reasonable overload could availably reduce the SCC growth rate during a certain in-service period. (author)

  20. Temperature distribution of a hot water storage tank in a simulated solar heating and cooling system

    Science.gov (United States)

    Namkoong, D.

    1976-01-01

    A 2,300-liter hot water storage tank was studied under conditions simulating a solar heating and cooling system. The initial condition of the tank, ranging from 37 C at the bottom to 94 C at the top, represented a condition midway through the start-up period of the system. During the five-day test period, the water in the tank gradually rose in temperature but in a manner that diminished its temperature stratification. Stratification was found not to be an important factor in the operation of the particular solar system studied.

  1. Relative frequencies and significance of faecal coliforms as indicators related to water temperature.

    Science.gov (United States)

    Auban, E G; Ripolles, A A; Domarco, M J

    1983-01-01

    The faecal coliforms at different sites of a hypereutrophic lake near Valencia (Albufera) were identified and their relative amounts established along an annual cycle. Using lauryl tryptose broth at 35 degrees C, followed by incubation at 44.4 degrees C in 2% brilliant green bile, Escherichia coli and Klebsiella pneumoniae are practically the only coliforms present. A positive correlation was found between the water temperature and the relative amount of these two coliforms: K. pneumoniae predominates at high water temperatures, whereas E. coli shows preponderance during the cold period. The role of K. pneumoniae as the only faecal indicator under the circumstances described in the work is emphasized and discussed.

  2. Behavior of pressure rise and condensation caused by water evaporation under vacuum at high temperature

    International Nuclear Information System (INIS)

    Takase, Kazuyuki; Kunugi, Tomoaki; Yamazaki, Seiichiro; Fujii, Sadao

    1998-01-01

    Pressure rise and condensation characteristics during the ingress-of-coolant event (ICE) in fusion reactors were investigated using the preliminary ICE apparatus with a vacuum vessel (VV), an additional tank (AT) and an isolation valve (IV). A surface of the AT was cooled by water at RT. The high temperature and pressure water was injected into the VV which was heated up to 250degC and pressure and temperature transients in the VV were measured. The pressure increased rapidly with an injection time of the water because of the water evaporation. After the IV was opened and the VV was connected with the AT, the pressure in the VV decreased suddenly. From a series of the experiments, it was confirmed that control factors on the pressure rise were the flushing evaporation and boiling heat transfer in the VV, and then, condensation of the vapor after was effective to the depressurization in the VV. (author)

  3. Assessments of Water Ingress Accidents in a Modular High-Temperature Gas-Cooled Reactor

    International Nuclear Information System (INIS)

    Zhang Zuoyi; Dong Yujie; Scherer, Winfried

    2005-01-01

    Severe water ingress accidents in the 200-MW HTR-module were assessed to determine the safety margins of modular pebble-bed high-temperature gas-cooled reactors (HTR-module). The 200-MW HTR-module was designed by Siemens under the criteria that no active safety protection systems were necessary because of its inherent safe nature. For simulating the behavior of the HTR-module during severe water ingress accidents, a water, steam, and helium multiphase cavity model was developed and implemented in the dynamic simulator for nuclear power plants (DSNP) simulation system. Comparisons of the DSNP simulations incorporating these models with experiments and with calculations using the time-dependent neutronics and temperature dynamics code were made to validate the simulation. The analysis of the primary circuit showed that the maximum water concentration increase in the reactor core was 3 s). The water vaporization in the steam generator and characteristics of water transport from the steam generator to the reactor core would reduce the rate of water ingress into the reactor core. The analysis of a full cavitation of the feedwater pump showed that if the secondary circuit could be depressurized, the feedwater pump would be stopped by the full cavitation. This limits the water transported from the deaerator to the steam generator. A comprehensive simulation of the HTR-module power plant showed that the water inventory in the primary circuit was limited to ∼3000 kg. The nuclear reactivity increase caused by the water ingress would lead to a fast power excursion, which would be inherently counterbalanced by negative feedback effects. The integrity of the fuel elements, because the safety-relevant temperature limit of 1600 deg. C is not reached in any case, is not challenged

  4. MRI findings in thoracic outlet syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Aralasmak, Ayse; Sharifov, Rasul; Kilicarslan, Rukiye; Alkan, Alpay [Bezmialem Vakif University, Department of Radiology, Fatih/Istanbul (Turkey); Cevikol, Can; Karaali, Kamil; Senol, Utku [Akdeniz University, Department of Radiology, Antalya (Turkey)

    2012-11-15

    We discuss MRI findings in patients with thoracic outlet syndrome (TOS). A total of 100 neurovascular bundles were evaluated in the interscalene triangle (IS), costoclavicular (CC), and retropectoralis minor (RPM) spaces. To exclude neurogenic abnormality, MRIs of the cervical spine and brachial plexus (BPL) were obtained in neutral. To exclude compression on neurovascular bundles, sagittal T1W images were obtained vertical to the longitudinal axis of BPL from spinal cord to the medial part of the humerus, in abduction and neutral. To exclude vascular TOS, MR angiography (MRA) and venography (MRV) of the subclavian artery (SA) and vein (SV) in abduction were obtained. If there is compression on the vessels, MRA and MRV of the subclavian vessels were repeated in neutral. Seventy-one neurovascular bundles were found to be abnormal: 16 arterial-venous-neurogenic, 20 neurogenic, 1 arterial, 15 venous, 8 arterial-venous, 3 arterial-neurogenic, and 8 venous-neurogenic TOS. Overall, neurogenic TOS was noted in 69%, venous TOS in 66%, and arterial TOS in 39%. The neurovascular bundle was most commonly compressed in the CC, mostly secondary to position, and very rarely compressed in the RPM. The cause of TOS was congenital bone variations in 36%, congenital fibromuscular anomalies in 11%, and position in 53%. In 5%, there was unilateral brachial plexitis in addition to compression of the neurovascular bundle. Severe cervical spondylosis was noted in 14%, contributing to TOS symptoms. For evaluation of patients with TOS, visualization of the brachial plexus and cervical spine and dynamic evaluation of neurovascular bundles in the cervicothoracobrachial region are mandatory. (orig.)

  5. Geothermal data-base study: mine-water temperatures. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, D.C.; Sonderegger, J.L.

    1978-07-01

    Investigation of about 1,600 mines and prospects for perennial discharge resulted in the measurement of temperature, pH, specific conductance, and discharge at 80 sites to provide information for a geothermal data base. Measurements were made in the fall, winter, and late spring or early summer to provide information about seasonal variability. None of the temperatures measured exceeded the mean annual air temperature by 15/sup 0/F, but three areas were noted where discharges were anomalously warm, based upon high temperatures, slight temperature variation, and quantity of discharge. The most promising area, at the Gold Bug mine in the Little Rockies, discharges water averaging 7.3/sup 0/C (12.1/sup 0/F) above the mean annual air temperature. The discharge may represent water heated during circulation within the syenite intrusive body. If the syenite is enriched in uranium and thorium, an abnormal amount of heat would be produced by radioactive decay. Alternatively, the water may move through deep permeable sedimentary strata, such as the Madison Group, and be discharged to the surface through fractures in the pluton.

  6. Non-invasive tissue temperature measurements based on quantitative diffuse optical spectroscopy (DOS) of water

    Energy Technology Data Exchange (ETDEWEB)

    Chung, S H [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Cerussi, A E; Tromberg, B J [Beckman Laser Institute and Medical Clinic, University of California, Irvine, 1002 Health Sciences Road, Irvine 92612, CA (United States); Merritt, S I [Masimo Corporation, 40 Parker, Irvine, CA 92618 (United States); Ruth, J, E-mail: bjtrombe@uci.ed [Department of Bioengineering, University of Pennsylvania, 210 S. 33rd Street, Room 240, Skirkanich Hall, Philadelphia, PA 19104 (United States)

    2010-07-07

    We describe the development of a non-invasive method for quantitative tissue temperature measurements using Broadband diffuse optical spectroscopy (DOS). Our approach is based on well-characterized opposing shifts in near-infrared (NIR) water absorption spectra that appear with temperature and macromolecular binding state. Unlike conventional reflectance methods, DOS is used to generate scattering-corrected tissue water absorption spectra. This allows us to separate the macromolecular bound water contribution from the thermally induced spectral shift using the temperature isosbestic point at 996 nm. The method was validated in intralipid tissue phantoms by correlating DOS with thermistor measurements (R = 0.96) with a difference of 1.1 {+-} 0.91 {sup 0}C over a range of 28-48 {sup 0}C. Once validated, thermal and hemodynamic (i.e. oxy- and deoxy-hemoglobin concentration) changes were measured simultaneously and continuously in human subjects (forearm) during mild cold stress. DOS-measured arm temperatures were consistent with previously reported invasive deep tissue temperature studies. These results suggest that DOS can be used for non-invasive, co-registered measurements of absolute temperature and hemoglobin parameters in thick tissues, a potentially important approach for optimizing thermal diagnostics and therapeutics.

  7. Oxygen isotope exchange rate between dissolved sulfate and water at hydrothermal temperatures

    International Nuclear Information System (INIS)

    Chiba, H.; Sakai, H.

    1985-01-01

    Oxygen isotope exchange rate between dissolved sulfate and water was experimentally determined at 100, 200 and 300 deg C. The isotope exchange rate is strongly dependent on temperature and pH of the solution. Combining the temperature and pH dependence of the reaction rate, the exchange reaction was estimated to be first-order with respect to sulfate. The logarithm of apparent rate constant of exchange reaction at a given temperature is a function of the pH calculated at the experimental temperatures. From the pH dependence of the apparent rate constant, it was deduced that the isotope exchange reaction between dissolved sulfate and water proceeds through collision between H 2 SO 4 0 and H 2 O at low pH, and between HSO 4 - and H 2 O at intermediate pH. The isotope exchange rate obtained indicates that oxygen isotope geothermometry utilizing the studied isotope exchange is suitable for temperature estimation of geothermal reservoirs. The extrapolated half-life of this reaction to oceanic temperature is about 10 9 years, implying that exchange between oceanic sulfate and water cannot control the oxygen isotope ratio of oceanic sulfates. (author)

  8. R/S analysis based study on long memory about CODMn in Poyang Lake Inlet and Outlet

    Science.gov (United States)

    Wang, Lili

    2018-02-01

    Rescaled range analysis (R/S) is applied to the long memory behavior analysis of water CODMn series in Poyang Lake Inlet and Outlet in China. The results show that these CODMn series are characterized by long memory, and the characteristics have obvious differences between the Lake Inlet and Outlet. Our findings suggest that there was an obvious scale invariance, namely CODMn series in Lake Inlet for 13 weeks and CODMn in Lake Outlet for 17 weeks. Both displayed a two-power-law distribution and a similar high long memory. We made a preliminary explanation for the existence of the boundary point tc , using self-organized criticality. This work can be helpful to improvement of modelling of lake water quality.

  9. Water and temperature stress define the optimal flowering period for wheat in south-eastern Australia

    OpenAIRE

    Evans, John; Kirkegaard, John; Hunt, James; Flohr, Bonnie

    2017-01-01

    Across the Australian wheat belt, the time at which wheat flowers is a critical determinant of yield. In all environments an optimal flowering period (OFP) exists which is defined by decreasing frost risk, and increasing water and heat stress. Despite their critical importance, OFPs have not been comprehensively defined across south eastern Australia′s (SEA) cropping zone using yield estimates incorporating temperature, radiation and water-stress. In this study, the widely validated cropping ...

  10. Noise analysis method for monitoring the moderator temperature coefficient of pressurized water reactors: Neural network calibration

    International Nuclear Information System (INIS)

    Thomas, J.R. Jr.; Adams, J.T.

    1994-01-01

    A neural network was trained with data for the frequency response function between in-core neutron noise and core-exit thermocouple noise in a pressurized water reactor, with the moderator temperature coefficient (MTC) as target. The trained network was subsequently used to predict the MTC at other points in the same fuel cycle. Results support use of the method for operating pressurized water reactors provided noise data can be accumulated for several fuel cycles to provide a training base

  11. Temperature dependence of broadline NMR spectra of water-soaked, epoxy-graphite composites

    Science.gov (United States)

    Lawing, David; Fornes, R. E.; Gilbert, R. D.; Memory, J. D.

    1981-10-01

    Water-soaked, epoxy resin-graphite fiber composites show a waterline in their broadline proton NMR spectrum which indicates a state of intermediate mobility between the solid and free water liquid states. The line is still present at -42 °C, but shows a reversible decrease in amplitude with decreasing temperature. The line is isotropic upon rotation of the fiber axis with respect to the external magnetic field.

  12. High Temperature Corrosion of Silicon Carbide and Silicon Nitride in Water Vapor

    Science.gov (United States)

    Opila, E. J.; Robinson, Raymond C.; Cuy, Michael D.; Gray, Hugh R. (Technical Monitor)

    2002-01-01

    Silicon carbide (SiC) and silicon nitride (Si3N4) are proposed for applications in high temperature combustion environments containing water vapor. Both SiC and Si3N4 react with water vapor to form a silica (SiO2) scale. It is therefore important to understand the durability of SiC, Si3N4 and SiO2 in water vapor. Thermogravimetric analyses, furnace exposures and burner rig results were obtained for these materials in water vapor at temperatures between 1100 and 1450 C and water vapor partial pressures ranging from 0.1 to 3.1 atm. First, the oxidation of SiC and Si3N4 in water vapor is considered. The parabolic kinetic rate law, rate dependence on water vapor partial pressure, and oxidation mechanism are discussed. Second, the volatilization of silica to form Si(OH)4(g) is examined. Mass spectrometric results, the linear kinetic rate law and a volatilization model based on diffusion through a gas boundary layer are discussed. Finally, the combined oxidation and volatilization reactions, which occur when SiC or Si3N4 are exposed in a water vapor-containing environment, are presented. Both experimental evidence and a model for the paralinear kinetic rate law are shown for these simultaneous oxidation and volatilization reactions.

  13. Flat Branch monitoring project: stream water temperature and sediment responses to forest cutting in the riparian zone

    Science.gov (United States)

    Barton D. Clinton; James M. Vose; Dick L. Fowler

    2010-01-01

    Stream water protection during timber-harvesting activities is of primary interest to forest managers. In this study, we examine the potential impacts of riparian zone tree cutting on water temperature and total suspended solids. We monitored stream water temperature and total suspended solids before and after timber harvesting along a second-order tributary of the...

  14. Acute Alcohol Consumption, Alcohol Outlets, and Gun Suicide

    Science.gov (United States)

    Branas, Charles C.; Richmond, Therese S.; Ten Have, Thomas R.; Wiebe, Douglas J.

    2014-01-01

    A case–control study of 149 intentionally self-inflicted gun injury cases (including completed gun suicides) and 302 population-based controls was conducted from 2003 to 2006 in a major US city. Two focal independent variables, acute alcohol consumption and alcohol outlet availability, were measured. Conditional logistic regression was adjusted for confounding variables. Gun suicide risk to individuals in areas of high alcohol outlet availability was less than the gun suicide risk they incurred from acute alcohol consumption, especially to excess. This corroborates prior work but also uncovers new information about the relationships between acute alcohol consumption, alcohol outlets, and gun suicide. Study limitations and implications are discussed. PMID:21929327

  15. Effect of short-term decrease in water temperature on body temperature and involvement of testosterone in steelhead and rainbow trout, Oncorhynchus mykiss.

    Science.gov (United States)

    Miura, Go; Munakata, Arimune; Yada, Takashi; Schreck, Carl B; Noakes, David L G; Matsuda, Hiroyuki

    2013-09-01

    The Pacific salmonid species Oncorhynchus mykiss is separated into a migratory form (steelhead trout) and a non-migratory form (rainbow trout). A decrease in water temperature is likely a cue triggering downstream behavior in the migratory form, and testosterone inhibits onset of this behavior. To elucidate differences in sensitivity to water temperature decreases between the migratory and non-migratory forms and effect of testosterone on the sensitivity, we examined two experiments. In experiment 1, we compared changes in body temperature during a short-term decrease in water temperature between both live and dead steelhead and rainbow trout. In experiment 2, we investigated effects of testosterone on body temperature decrease in steelhead trout. Water temperature was decreased by 3°C in 30min. The body temperature of the steelhead decreased faster than that of the rainbow trout. In contrast, there was no significant difference in the decrease in body temperature between dead steelhead and rainbow trout specimens. The body temperature of the testosterone-treated steelhead trout decreased more slowly than that of control fish. Our results suggest that the migratory form is more sensitive to decreases in water temperature than the non-migratory form. Moreover, testosterone might play an inhibitory role in sensitivity to such decreases. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Distributed Temperature Sensing - a Useful Tool for Investigation of Surface Water - Groundwater Interaction

    Science.gov (United States)

    Vogt, T.; Hahn-Woernle, L.; Sunarjo, B.; Thum, T.; Schneider, P.; Schirmer, M.; Cirpka, O. A.

    2009-04-01

    In recent years, the transition zone between surface water bodies and groundwater, known as the hyporheic zone, has been identified as crucial for the ecological status of the open-water body and the quality of groundwater. The hyporheic exchange processes vary both in time and space. For the assessment of water quality of both water bodies reliable models and measurements of the exchange rates and their variability are needed. A wide range of methods and technologies exist to estimate water fluxes between surface water and groundwater. Due to recent developments in sensor techniques and data logging work on heat as a tracer in hydrological systems advances, especially with focus on surface water - groundwater interactions. Here, we evaluate the use of Distributed Temperature Sensing (DTS) for the qualitative and quantitative investigation of groundwater discharge into and groundwater recharge from a river. DTS is based on the temperature dependence of Raman scattering. Light from a laser pulse is scattered along an optical fiber of up to several km length, which is the sensor of the DTS system. By sampling the the back-scattered light with high temporal resolution, the temperature along the fiber can be measured with high accuracy (0.1 K) and high spatial resolution (1 m). We used DTS at a test side at River Thur in North-East Switzerland. Here, the river is loosing and the aquifer is drained by two side-channels, enabling us to test DTS for both, groundwater recharge from the river and groundwater discharge into the side-channels. For estimation of seepage rates, we measured highly resolved vertical temperature profiles in the river bed. For this application, we wrapped an optical fiber around a piezometer tube and measured the temperature distribution along the fiber. Due to the wrapping, we obtained a vertical resolution of approximately 5 mm. We analyzed the temperature time series by means of Dynamic Harmonic Regression as presented by Keery et al. (2007

  17. Temperatures in a runaway greenhouse on the evolving Venus Implications for water loss

    Science.gov (United States)

    Watson, A. J.; Donahue, T. M.; Kuhn, W. R.

    1984-01-01

    Some aspects of the temperature structure of a runaway greenhouse on Venus are examined using one-dimensional radiative transfer techniques. It is found that there generally is a region high in the atmosphere where condensation and cloud formation can occur, while deep in the atmosphere the gas is strongly unsaturated with respect to water vapor. The necessity of including clouds introduces considerably uncertainty into the calculation of surface temperatures. Under reasonable assumptions concerning the clouds, temperatures deep in the atmosphere are high enough to produce a plastic or even molten surface, which may significantly ease the problem of explaining the loss of oxygen.

  18. Temperature Dependence of Mineral Solubility in Water. Part 2. Alkaline and Alkaline Earth Bromides

    Science.gov (United States)

    Krumgalz, B. S.

    2018-03-01

    Databases of alkaline and alkaline earth bromide solubilities in water at various temperatures were created using experimental data from publications over about the last two centuries. Statistical critical evaluation of the created databases was produced since there were enough independent data sources to justify such evaluation. The reliable experimental data were adequately described by polynomial expressions over various temperature ranges. Using the Pitzer approach for ionic activity and osmotic coefficients, the thermodynamic solubility products for the discussed bromide minerals have been calculated at various temperature intervals and also represented by polynomial expressions.

  19. Map-based prediction of organic carbon in headwater streams improved by downstream observations from the river outlet

    Science.gov (United States)

    Temnerud, J.; von Brömssen, C.; Fölster, J.; Buffam, I.; Andersson, J.-O.; Nyberg, L.; Bishop, K.

    2016-01-01

    In spite of the great abundance and ecological importance of headwater streams, managers are usually limited by a lack of information about water chemistry in these headwaters. In this study we test whether river outlet chemistry can be used as an additional source of information to improve the prediction of the chemistry of upstream headwaters (size interquartile range (IQR)) of headwater stream TOC for a given catchment, based on a large number of candidate variables including sub-catchment characteristics from GIS, and measured river chemistry at the catchment outlet. The best candidate variables from the PLS models were then used in hierarchical linear mixed models (MM) to model TOC in individual headwater streams. Three predictor variables were consistently selected for the MM calibration sets: (1) proportion of forested wetlands in the sub-catchment (positively correlated with headwater stream TOC), (2) proportion of lake surface cover in the sub-catchment (negatively correlated with headwater stream TOC), and (3) river outlet TOC (positively correlated with headwater stream TOC). Including river outlet TOC improved predictions, with 5-15 % lower prediction errors than when using map information alone. Thus, data on water chemistry measured at river outlets offer information which can complement GIS-based modelling of headwater stream chemistry.

  20. Seasonal lake surface water temperature trends reflected by heterocyst glycolipid-based molecular thermometers

    Science.gov (United States)

    Bauersachs, T.; Rochelmeier, J.; Schwark, L.

    2015-06-01

    It has been demonstrated that the relative distribution of heterocyst glycolipids (HGs) in cultures of N2-fixing heterocystous cyanobacteria is largely controlled by growth temperature, suggesting a potential use of these components in paleoenvironmental studies. Here, we investigated the effect of environmental parameters (e.g., surface water temperatures, oxygen concentrations and pH) on the distribution of HGs in a natural system using water column filtrates collected from Lake Schreventeich (Kiel, Germany) from late July to the end of October 2013. HPLC-ESI/MS (high-performance liquid chromatography coupled to electrospray ionization-mass spectrometry) analysis revealed a dominance of 1-(O-hexose)-3,25-hexacosanediols (HG26 diols) and 1-(O-hexose)-3-keto-25-hexacosanol (HG26 keto-ol) in the solvent-extracted water column filtrates, which were accompanied by minor abundances of 1-(O-hexose)-3,27-octacosanediol (HG28 diol) and 1-(O-hexose)-3-keto-27-octacosanol (HG28 keto-ol) as well as 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol) and 1-(O-hexose)-3-keto-25,27-octacosanediol (HG28 keto-diol). Fractional abundances of alcoholic and ketonic HGs generally showed strong linear correlations with surface water temperatures and no or only weak linear correlations with both oxygen concentrations and pH. Changes in the distribution of the most abundant diol and keto-ol (e.g., HG26 diol and HG26 keto-ol) were quantitatively expressed as the HDI26 (heterocyst diol index of 26 carbon atoms) with values of this index ranging from 0.89 in mid-August to 0.66 in mid-October. An average HDI26 value of 0.79, which translates into a calculated surface water temperature of 15.8 ± 0.3 °C, was obtained from surface sediments collected from Lake Schreventeich. This temperature - and temperatures obtained from other HG indices (e.g., HDI28 and HTI28) - is similar to the one measured during maximum cyanobacterial productivity in early to mid-September and suggests that HGs

  1. The 3D thermal-hydraulic numerical simulation for the fuel zone outlet of China experimental fast reactor

    International Nuclear Information System (INIS)

    Xue Xiuli; Yang Hongyi; Yang Fuchang

    2008-01-01

    Detailed 3D thermal-hydraulic numerical analyses to the fuel zone outlet are actualized with the STAR-CD CFD code. The performance of sodium mixing is studied and detailed velocity and temperature distribution are obtained in this region which will offer foundations and references to study the rationality of temperature monitoring-spot arrangement and to assess the effect of temperature fluctuations to control rod guide tubes in this region, and so on. (authors)

  2. The Effect of Pressure and Temperature on Mid-Infrared Sensing of Dissolved Hydrocarbons in Water.

    Science.gov (United States)

    Heath, Charles; Myers, Matthew; Pejcic, Bobby

    2017-12-19

    Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy using a polymer coated internal reflection element/waveguide is an established sensor platform for the detection of a range of organic and hydrocarbon molecules dissolved in water. The polymer coating serves two purposes: to concentrate hydrocarbons from the aqueous phase and to exclude water along with other interfering molecules from the surface of the internal reflection element. Crucial to reliable quantification and analytical performance is the calibration of the ATR-FTIR sensor which is commonly performed in water under mild ambient conditions (i.e., 25 °C and 1 atm). However, there is a pressing need to monitor environmental and industrial processes/events that may occur at high pressures and temperatures where this calibration approach is unsuitable. Using a ruggedized optical fiber probe with a diamond-based ATR, we have conducted mid-infrared sensor experiments to understand the influence of high pressure (up to 207 bar) and temperature (up to 80 °C) on the detection of toluene and naphthalene dissolved in water. Using a poly(isobutylene) film, we have shown that the IR spectroscopic response is relatively unaffected by changes in pressure; however, a diminished response was observed with increasing temperature. We reveal that changes in the refractive index of the polymer film with temperature have only a minor effect on sensitivity. A more plausible explanation for the observed significant change in sensor response with temperature is that the partitioning process is exothermic and becomes less favorable with increasing temperature. This Article shows that the sensitivity is relatively invariant to pressure; however, the thermal variations are significant and need to be considered when quantifying the concentration of hydrocarbons in water.

  3. Improving image quality by accounting for changes in water temperature during a photoacoustic tomography scan.

    Directory of Open Access Journals (Sweden)

    Dominique Van de Sompel

    Full Text Available The emerging field of photoacoustic tomography is rapidly evolving with many new system designs and reconstruction algorithms being published. Many systems use water as a coupling medium between the scanned object and the ultrasound transducers. Prior to a scan, the water is heated to body temperature to enable small animal imaging. During the scan, the water heating system of some systems is switched off to minimize the risk of bubble formation, which leads to a gradual decrease in water temperature and hence the speed of sound. In this work, we use a commercially available scanner that follows this procedure, and show that a failure to model intra-scan temperature decreases as small as 1.5°C leads to image artifacts that may be difficult to distinguish from true structures, particularly in complex scenes. We then improve image quality by continuously monitoring the water temperature during the scan and applying variable speed of sound corrections in the image reconstruction algorithm. While upgrading to an air bubble-free heating pump and keeping it running during the scan could also solve the changing temperature problem, we show that a software correction for the temperature changes provides a cost-effective alternative to a hardware upgrade. The efficacy of the software corrections was shown to be consistent across objects of widely varying appearances, namely physical phantoms, ex vivo tissue, and in vivo mouse imaging. To the best of our knowledge, this is the first study to demonstrate the efficacy of modeling temporal variations in the speed of sound during photoacoustic scans, as opposed to spatial variations as focused on by previous studies. Since air bubbles pose a common problem in ultrasonic and photoacoustic imaging systems, our results will be useful to future small animal imaging studies that use scanners with similarly limited heating units.

  4. SCC growth behavior of stainless steel weld heat-affected zone in hydrogenated high temperature water

    International Nuclear Information System (INIS)

    Yamada, Takuyo; Terachi, Takumi; Miyamoto, Tomoki; Arioka, Koji

    2010-01-01

    It is known that the SCC growth rate of stainless steels in high-temperature water is accelerated by cold-work (CW). The weld heat-affected-zone (HAZ) of stainless steels is also deformed by weld shrinkage. However, only little have been reported on the SCC growth of weld HAZ of SUS316 and SUS304 in hydrogenated high-temperature water. Thus, in this present study, SCC growth experiments were performed using weld HAZ of stainless steels, especially to obtain data on the dependence of SCC growth on (1) temperature and (2) hardness in hydrogenated water at temperatures from 250degC to 340degC. And then, the SCC growth behaviors were compared between weld HAZ and CW stainless steels. The following results have been obtained. Significant SCC growth were observed in weld HAZ (SUS316 and SUS304) in hydrogenated water at 320degC. The SCC growth rates of the HAZ are similar to that of 10% CW non-sensitized SUS316, in accordance with that the hardness of weld HAZ is also similar to that of 10% CW SUS316. Temperature dependency of SCC growth of weld HAZ (SUS316 and SUS304) is also similar to that of 10% CW non-sensitized SUS316. That is, no significant SCC were observed in the weld HAZ (SUS316 and SUS304) in hydrogenated water at 340degC. This suggests that SCC growth behaviors of weld HAZ and CW stainless steels are similar and correlated with the hardness or yield strength of the materials, at least in non-sensitized regions. And the similar temperature dependence between the HAZ and CW stainless steels suggests that the SCC growth behaviors are also attributed to the common mechanism. (author)

  5. Crack embryo formation before crack initiation and growth in high temperature water

    International Nuclear Information System (INIS)

    Arioka, Koji; Yamada, Takuyo; Terachi, Takumi; Miyamoto, Tomoki

    2008-01-01

    Crack growth measurements were performed in high temperature water and in air to examine the role of creep on IGSCC growth using cold rolled non-sensitized Type316(UNS S31600), TT690 alloy, MA600 alloy, and Carbon steel (STPT42). In addition, crack initiation tests were performed also in high temperature water and in air using specially designed CT specimen. The obtained major results are as follows: (1) TT690 did crack in intergranularly in hydrogenated high temperature water if material is cold worked in heavily. (2) Cold worked carbon steel also cracked in intergranularly in dearated high temperature water. (3) Intergranular crack growth was recognized on cold worked 316, TT690, MA600, and carbon steel even in air which might be crack embryo of IGSCC. (4) Simple Arrhenius type temperature dependence was observed on IGSCC in high temperature water and creep crack growth in air. This suggested that intergranular crack growth rate was determined by some thermal activated reaction. (5) Vacancy condensation was recognized at just ahead of the crack tips of IGSCC and creep crack of cold worked steel. This showed that IGSCC and creep crack growth was controlled by same mechanism. (6) Clear evidence of vacancies condensation was recognized at just beneath the surface before crack initiation. This proved that crack did initiate as the result of diffusion of vacancies in the solid. And the incubation time seems to be controlled by the required time for the condensation of vacancies to the stress concentrated zone. (7) Diffusion of subsituational atoms was also driven by stress gradient. This is the important knowledge to evaluate the SCC initiation after long term operation in LWR's. Based on the observed results, IGSCC initiation and growth mechanism were proposed considering the diffusion process of cold worked induced vacancies. (author)

  6. Temperature-Correlated Changes in Phytoplankton Community Structure Are Restricted to Polar Waters.

    Science.gov (United States)

    Ward, Ben A

    2015-01-01

    Globally distributed observations of size-fractionated chlorophyll a and temperature were used to incorporate temperature dependence into an existing semi-empirical model of phytoplankton community size structure. The additional temperature-dependent term significantly increased the model's ability to both reproduce and predict observations of chlorophyll a size-fractionation at temperatures below 2°C. The most notable improvements were in the smallest (picoplankton) size-class, for which overall model fit was more than doubled, and predictive skill was increased by approximately 40%. The model was subsequently applied to generate global maps for three phytoplankton size classes, on the basis of satellite-derived estimates of surface chlorophyll a and sea surface temperature. Polar waters were associated with marked decline in the chlorophyll a biomass of the smallest cells, relative to lower latitude waters of equivalent total chlorophyll a. In the same regions a complementary increase was seen in the chlorophyll a biomass of larger size classes. These findings suggest that a warming and stratifying ocean will see a poleward expansion of the habitat range of the smallest phytoplankton, with the possible displacement of some larger groups that currently dominate. There was no evidence of a strong temperature dependence in tropical or sub-tropical regions, suggesting that future direct temperature effects on community structure at lower latitudes may be small.

  7. Using diurnal temperature signals to infer vertical groundwater-surface water exchange

    Science.gov (United States)

    Irvine, Dylan J.; Briggs, Martin A.; Lautz, Laura K.; Gordon, Ryan P.; McKenzie, Jeffrey M.; Cartwright, Ian

    2017-01-01

    Heat is a powerful tracer to quantify fluid exchange between surface water and groundwater. Temperature time series can be used to estimate pore water fluid flux, and techniques can be employed to extend these estimates to produce detailed plan-view flux maps. Key advantages of heat tracing include cost-effective sensors and ease of data collection and interpretation, without the need for expensive and time-consuming laboratory analyses or induced tracers. While the collection of temperature data in saturated sediments is relatively straightforward, several factors influence the reliability of flux estimates that are based on time series analysis (diurnal signals) of recorded temperatures. Sensor resolution and deployment are particularly important in obtaining robust flux estimates in upwelling conditions. Also, processing temperature time series data involves a sequence of complex steps, including filtering temperature signals, selection of appropriate thermal parameters, and selection of the optimal analytical solution for modeling. This review provides a synthesis of heat tracing using diurnal temperature oscillations, including details on optimal sensor selection and deployment, data processing, model parameterization, and an overview of computing tools available. Recent advances in diurnal temperature methods also provide the opportunity to determine local saturated thermal diffusivity, which can improve the accuracy of fluid flux modeling and sensor spacing, which is related to streambed scour and deposition. These parameters can also be used to determine the reliability of flux estimates from the use of heat as a tracer.

  8. Evaporation and Ignition Characteristics of Water Emulsified Diesel under Conventional and Low Temperature Combustion Conditions

    Directory of Open Access Journals (Sweden)

    Zhaowen Wang

    2017-07-01

    Full Text Available The combination of emulsified diesel and low temperature combustion (LTC technology has great potential in reducing engine emissions. A visualization study on the spray and combustion characteristics of water emulsified diesel was conducted experimentally in a constant volume chamber under conventional and LTC conditions. The effects of ambient temperature on the evaporation, ignition and combustion characteristics of water emulsified diesel were studied under cold, evaporating and combustion conditions. Experimental results showed that the ambient temperature had little effect on the spray structures, in terms of the liquid core length, the spray shape and the spray area. However, higher ambient temperature slightly reduced the Sauter Mean Diameter (SMD of the spray droplets. The auto-ignition delay time increased significantly with the decrease of the ambient temperature. The ignition process always occurred at the entrainment region near the front periphery of the liquid core. This entrainment region was evolved from the early injected fuel droplets which were heated and mixed by the continuous entrainment until the local temperature and equivalence ratio reached the ignition condition. The maximum value of integrated natural flame luminosity (INFL reduced by 60% when the ambient temperature dropped from 1000 to 800 K, indicating a significant decrease of the soot emissions could be achieved by LTC combustion mode than the conventional diesel engines.

  9. Temperature and particle-size dependent viscosity data for water-based nanofluids - Hysteresis phenomenon

    International Nuclear Information System (INIS)

    Nguyen, C.T.; Desgranges, F.; Roy, G.; Galanis, N.; Mare, T.; Boucher, S.; Angue Mintsa, H.

    2007-01-01

    In the present paper, we have investigated experimentally the influence of both the temperature and the particle size on the dynamic viscosities of two particular water-based nanofluids, namely water-Al 2 O 3 and water-CuO mixtures. The measurement of nanofluid dynamic viscosities was accomplished using a 'piston-type' calibrated viscometer based on the Couette flow inside a cylindrical measurement chamber. Data were collected for temperatures ranging from ambient to 75 deg. C, for water-Al 2 O 3 mixtures with two different particle diameters, 36 nm and 47 nm, as well as for water-CuO nanofluid with 29 nm particle size. The results show that for particle volume fractions lower than 4%, viscosities corresponding to 36 nm and 47 nm particle-size alumina-water nanofluids are approximately identical. For higher particle fractions, viscosities of 47 nm particle-size are clearly higher than those of 36 nm size. Viscosities corresponding to water-oxide copper are the highest among the nanofluids tested. The temperature effect has been investigated thoroughly. A more complete viscosity data base is presented for the three nanofluids considered, with several experimental correlations proposed for low particle volume fractions. It has been found that the application of Einstein's formula and those derived from the linear fluid theory seems not to be appropriate for nanofluids. The hysteresis phenomenon on viscosity measurement, which is believed to be the first observed for nanofluids, has raised serious concerns regarding the use of nanofluids for heat transfer enhancement purposes

  10. Fast Rotational Diffusion of Water Molecules in a 2D Hydrogen Bond Network at Cryogenic Temperatures

    Science.gov (United States)

    Prisk, T. R.; Hoffmann, C.; Kolesnikov, A. I.; Mamontov, E.; Podlesnyak, A. A.; Wang, X.; Kent, P. R. C.; Anovitz, L. M.

    2018-05-01

    Individual water molecules or small clusters of water molecules contained within microporous minerals present an extreme case of confinement where the local structure of hydrogen bond networks are dramatically altered from bulk water. In the zinc silicate hemimorphite, the water molecules form a two-dimensional hydrogen bond network with hydroxyl groups in the crystal framework. Here, we present a combined experimental and theoretical study of the structure and dynamics of water molecules within this network. The water molecules undergo a continuous phase transition in their orientational configuration analogous to a two-dimensional Ising model. The incoherent dynamic structure factor reveals two thermally activated relaxation processes, one on a subpicosecond timescale and another on a 10-100 ps timescale, between 70 and 130 K. The slow process is an in-plane reorientation of the water molecule involving the breaking of hydrogen bonds with a framework that, despite the low temperatures involved, is analogous to rotational diffusion of water molecules in the bulk liquid. The fast process is a localized motion of the water molecule with no apparent analogs among known bulk or confined phases of water.

  11. Climate change impacts on the temperature of recharge water in a temporate climate

    Science.gov (United States)

    Murdock, E. A.

    2015-12-01

    Groundwater outflows into headwater streams play an important role in controlling local stream temperature and maintaining habitat for cool and cold water fisheries. Because of the ecological and economic importance of these fisheries, there is significant concern about the impacts of climate change on these habitats. Many studies of stream temperature changes under climate change assume that groundwater outflows will vary with long-term mean air temperature, perhaps with a temporal lag to account for the relatively slow rate of heat diffusion through soils. This assumption, however, ignores the fact that climate change will also impact the temporal patterns of recharge in some regions. In Southern Wisconsin, much of the annual recharge comes from the spring snowmelt event, as a large amount of meltwater is released onto saturated soils with little to no active transpiration. Using the Simultaneous Heat and Water (SHAW) model populated with climate date from the North American Regional Climate Change Assessment Program (NARCCAP), we show that the temperature of water passing below the rooting zone in a simulated corn planting in Southern Wisconsin will change significantly less than the air temperature by midcentury. This finding highlights the importance of understanding the variability of heat flow mechanisms in the subsurface while assessing climate change impacts on surface water resources. In landscapes such as Wisconsin's driftless area, where deep aquifers feed numerous localized headwater streams, meltwater-driven recharge may provide a buffer against rising air temperatures for some time into the future. Fully understanding this dynamic will allow for targeted conservation efforts in those streams that are likely to show higher than average resilience to rising temperatures, but which remain vulnerable to development, stormwater runoff, agricultural pollution and other ecological threats. In a world with dwindling coldwater resources, identifying and

  12. Filterability of corrosion products formed between carbon steel and water. Influence of temperature and oxygen content

    International Nuclear Information System (INIS)

    Kelen, T.; Falk, I.

    1975-09-01

    A laboratory investigation has been made for the purpose of studying the influence of temperature and oxygen content on the filterability of corrosion products formed between carbon-steel and water. The experiments were performed in a high temperature loop where the water is initially heated in a pre-heater, then cooled and finally filtered. The corrosion products were transferred to thewater from a carbon-steel surface that had previously been neutron activated and the amount of iron present was determined from measurements of the γ-radiation emitted by Fe-59. Filterability was then computed as the ratio between the total amount of iron in the water phase and the amount of iron retained on the filter. The investigation covers a series of experiments at filtering temperatures of 20, 90 and 160 dec G, pre-heater temperatures up to 300 deg C and oxygen contents of 10 and 300 ppb O 2 . In addition the extent of iron deposition in the pre-heater and heat regulator has been determined after each series of experiments. Filterability exhibited a pronounced dependence upon both the filter and pre-heater temperatures and also upon the oxygen content. Among the conclusions to which the results lead is the observation that a strict comparison of filterability values for the fraction of corrosion products in cooled water samples is impossible when these are taken from 1) different sections of a high temperature system 2) a single sampling point while the system is being run up 3) two separate systems (e.g. steam boilers) operated at different temperatures 4) two separate systems operated at different oxygen contents. It accordingly appears advizable to restrict the use of cold-filtered samples from conventional steam-raising plants to the comparison of values relating to a single sampling point under constant operating conditions. (author)

  13. Impact of temperature on nitrification in biological activated carbon (BAC) filters used for drinking water treatment.

    Science.gov (United States)

    Andersson, A; Laurent, P; Kihn, A; Prévost, M; Servais, P

    2001-08-01

    The impact of temperature on nitrification in biological granular activated carbon (GAC) filters was evaluated in order to improve the understanding of the nitrification process in drinking water treatment. The study was conducted in a northern climate where very cold water temperatures (below 2 degrees C) prevail for extended periods and rapid shifts of temperature are frequent in the spring and fall. Ammonia removals were monitored and the fixed nitrifying biomass was measured using a method of potential nitrifying activity. The impact of temperature was evaluated on two different filter media: an opened superstructure wood-based activated carbon and a closed superstructure activated carbon-based on bituminous coal. The study was conducted at two levels: pilot scale (first-stage filters) and full-scale (second-stage filters) and the results indicate a strong temperature impact on nitrification activity. Ammonia removal capacities ranged from 40 to 90% in pilot filters, at temperatures above 10 degrees C, while more than 90% ammonia was removed in the full-scale filters for the same temperature range. At moderate temperatures (4-10 degrees C), the first stage pilot filters removed 10-40% of incoming ammonia for both media (opened and closed superstructure). In the full-scale filters, a difference between the two media in nitrification performances was observed at moderate temperatures: the ammonia removal rate in the opened superstructure support (more than 90%) was higher than in the closed superstructure support (45%). At low temperatures (below 4 degrees C) both media performed poorly. Ammonia removal capacities were below 30% in both pilot- and full-scale filters.

  14. Analysis of the temperature effect on the water retention capacity of soil using a thermodynamic approach

    International Nuclear Information System (INIS)

    Jacinto, A.C.; Ledesma, A.; Villar, M.V.

    2012-01-01

    Document available in extended abstract form only. Soils consist of a solid skeleton (matrix) with pores in between. The pores have different sizes, shapes and spatial distributions and provide the space for storage and transport of liquid and gas. In dealing with the analysis of coupled thermo-hydro-mechanical problems in unsaturated soils, it is necessary a relationship between the water fraction in the soil and a measure of the soil capacity to hold water in its pores against forces resulting from external actions. In Geotechnical Engineering, the energy status of water in the soil has been traditionally called suction , which has unit of stress. The pores of a soil are of many different kinds and may vary in size and in shape. Each range of pore size is associated with a characteristic adsorptive behaviour. The adsorption process is a consequence of the force field at the surface of the solid, which attracts the molecules of the gas or liquid. The physical adsorption is the main mechanism of binding of water in fine soils. It includes dispersion forces and short-range repulsive forces. In addition there may be forces due to permanent dipoles within the adsorbed molecules. Adhesion is the attraction of dissimilar substances for each other while cohesion is the mutual attraction of particles of the same substance. The adhesive forces together with the cohesive forces between water molecules form the basis for capillary binding of soil water. This is the most important mechanism of binding of water in coarse soils. When a sorbate (gas or vapour) is in contact with sorbent (solid), the amount adsorbed per gram of solid depends on the equilibrium pressure, the temperature, and also on the nature of the gas and of the solid. Equilibrium pressure refers to the pressure of the vapour in thermodynamic equilibrium with the adsorbed liquid. For a given gas adsorbed on a given solid at a fixed temperature, the adsorption is only a function of the pressure. The relation

  15. Survival of Mycobacterium avium in drinking water biofilms as affected by water flow velocity, availability of phosphorus, and temperature.

    Science.gov (United States)

    Torvinen, Eila; Lehtola, Markku J; Martikainen, Pertti J; Miettinen, Ilkka T

    2007-10-01

    Mycobacterium avium is a potential pathogen occurring in drinking water systems. It is a slowly growing bacterium producing a thick cell wall containing mycolic acids, and it is known to resist chlorine better than many other microbes. Several studies have shown that pathogenic bacteria survive better in biofilms than in water. By using Propella biofilm reactors, we studied how factors generally influencing the growth of biofilms (flow rate, phosphorus concentration, and temperature) influence the survival of M. avium in drinking water biofilms. The growth of biofilms was followed by culture and DAPI (4',6'-diamidino-2-phenylindole) staining, and concentrations of M. avium were determined by culture and fluorescence in situ hybridization methods. The spiked M. avium survived in biofilms for the 4-week study period without a dramatic decline in concentration. The addition of phosphorus (10 microg/liter) increased the number of heterotrophic bacteria in biofilms but decreased the culturability of M. avium. The reason for this result is probably that phosphorus increased competition with other microbes. An increase in flow velocity had no effect on the survival of M. avium, although it increased the growth of biofilms. A higher temperature (20 degrees C versus 7 degrees C) increased both the number of heterotrophic bacteria and the survival of M. avium in biofilms. In conclusion, the results show that in terms of affecting the survival of slowly growing M. avium in biofilms, temperature is a more important factor than the availability of nutrients like phosphorus.

  16. Study of Physical Properties for Sodium acetate with Water and Water - Acetone mixtures at Different Temperatures

    Directory of Open Access Journals (Sweden)

    Ahmed Mohammed Abbas

    2017-02-01

    Full Text Available In this study binary and ternary solutions are prepared by using the sodium acetate concentrations (0.1, 0.125, 0.2, 0.25, 0.4, 0.5, 0.8, 1 M in water and acetone –water mixtures .The important parameters such as apparent molal volume, the partial molal volume transfer,  apparent  molal compressibility, free energy of activation of viscous flow and thermodynamic activation parameter (enthalpy and entropy determined of sodium acetate in water , 20%, 40% ,60% and 80% V/V acetone –water mixtures at 298.15K, 303.15K, and 308.15K from density and viscosity measurements espectively. The limiting apparent molal volumes and experimental slopes were derived from the Masson equation, have been interpreted in terms of solute–solvent and solute–solute interactions  respectively. The viscosity data were analyzed using theJones–Dole equation and the derived parameter B - coefficient has also been interpreted in terms of solute–solvent interactions in the solutions.

  17. Effects of water stress and high temperature on photosynthetic rates of two species of Prosopis.

    Science.gov (United States)

    Delatorre, Jose; Pinto, Manuel; Cardemil, Liliana

    2008-08-21

    The main aim of this research was to compare the photosynthetic responses of two species of Prosopis, Prosopis chilensis (algarrobo) and Prosopis tamarugo (tamarugo) subjected to heat and water stress, to determine how heat shock or water deficit, either individually or combined, affect the photosynthesis of these two species. The photosynthetic rates expressed as a function of photon flow density (PFD) were determined by the O(2) liberated, in seedlings of tamarugo and algarrobo subjected to two water potentials: -0.3 MPa and -2.5 MPa and to three temperatures: 25 degrees C, 35 degrees C and 40 degrees C. Light response curves were constructed to obtain light compensation and light saturation points, maximum photosynthetic rates, quantum yields and dark respiration rates. The photochemical efficiency as the F(v)/F(m) ratio and the amount of RUBISCO were also determined under heat shock, water deficit, and under the combined action of both stress. Photosynthetic rates at a light intensity higher than 500 micromole photons m(-2)s(-1) were not significantly different (P>0.05) between species when measured at 25 degrees C under the same water potential. The maximum photosynthetic rates decreased with temperature in both species and with water deficit in algarrobo. At 40 degrees C and -2.5 MPa, the photosynthetic rate of algarrobo fell to 72% of that of tamarugo. The quantum yield decreased in algarrobo with temperature and water deficit and it was reduced by 50% when the conditions were 40 degrees C and -2.5 MPa. Dark respiration increased by 62% respect to the control at 40 degrees C in tamarugo while remained unchanged in algarrobo. The photochemical efficiency decreased with both, high temperature and water deficit, without differences between species. RUBISCO content increased in algarrobo 35 degrees C. Water deficit reduced the amount of RUBISCO in both species. The results of this work support the conclusion that in both Prosopis species, the interaction between

  18. Thermal infrared remote sensing for riverscape analysis of water temperature heterogeneity: current research and future directions

    Science.gov (United States)

    Dugdale, S.; Hannah, D. M.; Malcolm, I.; Bergeron, N.; St-Hilaire, A.

    2016-12-01

    Climate change will increase summer water temperatures in northern latitude rivers. It is likely that this will have a negative impact on fish species such as salmonids, which are sensitive to elevated temperatures. Salmonids currently avoid heat stress by opportunistically using cool water zones that arise from the spatio-temporal mosaic of thermal habitats present within rivers. However, there is a general lack of information about the processes driving this thermal habitat heterogeneity or how these spatio-temporal patterns might vary under climate change. In this paper, we document how thermal infrared imaging has previously been used to better understand the processes driving river temperature patterns. We then identify key knowledge gaps that this technology can help to address in the future. First, we demonstrate how repeat thermal imagery has revealed the role of short-term hydrometeorological variability in influencing longitudinal river temperature patterns, showing that precipitation depth is strongly correlated with the degree of longitudinal temperature heterogeneity. Second, we document how thermal infrared imagery of a large watershed in Eastern Canada has shed new light on the landscape processes driving the spatial distribution of cool water patches, revealing that the distribution of cool patches is strongly linked to channel confinement, channel curvature and the proximity of dry tributary valleys. Finally, we detail gaps in current understanding of spatio-temporal patterns of river temperature heterogeneity. We explain how advances in unmanned aerial vehicle technology and deterministic temperature modelling will be combined to address these current limitations, shedding new light on the landscape processes driving geographical variability in patterns of river temperature heterogeneity. We then detail how such advances will help to identify rivers that will be resilient to future climatic warming, improving current and future strategies for

  19. The dynamics of Orimulsion in water with varying energy, salinity and temperature

    International Nuclear Information System (INIS)

    Fingas, M.F.; Fieldhouse, B.; Wang, Z.; Environment Canada, Ottawa, ON

    2004-01-01

    Orimulsion is a surfactant-stabilized oil-in-water emulsion composed of 70 per cent bitumen and 30 per cent water. Its unique composition causes it to behave differently from conventional fuel oils when spilled at sea. Earlier studies have shown that Orimulsion is driven by buoyancy to rise in salt water and sink in fresh water. This study conducted 11 experiments at lower temperature and salinity values to obtain new information on the behaviour of Orimulsion in salt, fresh and brackish water. The applied rotational field was adjusted to vary the energy. A time-series of samples of Orimulsion in a 300 litre tank of water were taken to determine depletion rates and characteristics. Oil on the surface was quantified and the concentration of bitumen and particle size distribution was determined. The study also measured changes in bitumen concentration and particle size distribution as a function of time. The data was used to develop simple equations that predict concentrations of bitumen resurfacing and remaining in the water column as a function of time. It was concluded that there is a complex interaction between salinity, time, energy and temperature. 9 refs., 5 tabs., 8 figs

  20. WC as a non-platinum hydrogen evolution electrocatalyst for high temperature PEM water electrolysers

    DEFF Research Database (Denmark)

    Nikiforov, Aleksey; Petrushina, Irina; Christensen, Erik

    2012-01-01

    Tungsten carbide (WC) nanopowder was tested as a non-platinum cathode electrocatalyst for polymer electrolyte membrane (PEM) water electrolysers, operating at elevated temperatures. It was prepared in thermal plasma reactor with confined plasma jet from WO3 precursor in combination with CH4...

  1. Tests of ball bearing used in high-temperature and high-purity water

    International Nuclear Information System (INIS)

    Leng Chengmu; Hao Shouxin.

    1987-01-01

    According to the particular conditions and the operation environments in high-temperature and high-purity water, the test content and the measurement instrumentation for the ball bearing were defined. Through various tests, operational performances of the bearing have preliminarily been understood. It provided some useful information for the engineering application of the bearing

  2. Effects of salinity and water temperature on the ecological performance of Zostera marina

    DEFF Research Database (Denmark)

    Nejrup, Lars Brammer; Pedersen, Morten Foldager

    2008-01-01

    We tested the effects of salinity and water temperature on the ecological performance of eelgrass (Zostera marina L.) in culture-experiments to identify levels that could potentially limit survival and growth and, thus, the spatial distribution of eelgrass in temperate estuaries. The experiments ...

  3. Biodegradation of Toluene under seasonal and diurnal fluctuations of soil-water temperature

    NARCIS (Netherlands)

    Yadav, B.K.; Shrestha, S.R.; Hassanizadeh, S.M.

    2012-01-01

    An increasing interest in bioremediation of hydrocarbon polluted sites raises the question of the influence of seasonal and diurnal changes on soil-water temperature on biodegradation of BTEX, a widespread group of (sub)-surface contaminants. Therefore, we investigated the impact of a wide range of

  4. Oxidation of X20 in Water Vapour: The Effect of Temperature and Oxygen Partial Pressure

    DEFF Research Database (Denmark)

    Hansson, Anette Nørgaard; Montgomery, Melanie; Somers, Marcel A. J.

    2009-01-01

    The oxidation behaviour of X20 in various mixtures of water, oxygen and hydrogen was investigated at temperatures between 500 C and 700 C (time: 336 h). The samples were characterised using reflected light microscopy and scanning electron microscopy equipped with energy dispersive spectroscopy...

  5. Observed and simulated temperature dependence of the liquid water path of low clouds

    Energy Technology Data Exchange (ETDEWEB)

    Del Genio, A.D.; Wolf, A.B. [NASA Goddard Institute for Space Studies, New York, NY (United States)

    1996-04-01

    Data being acquired at the Atmospheric Radiation Measurement (ARM) Southern great Plains (SGP) Cloud and Radiation Testbed (CART) site can be used to examine the factors determining the temperature dependence of cloud optical thickness. We focus on cloud liquid water and physical thickness variations which can be derived from existing ARM measurements.

  6. Evaluations of different domestic hot water preparing methods with ultra-low-temperature district heating

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

    2016-01-01

    of Legionella in the DHW (domestic hot water) and assure the comfortable temperature, all substations were installed with supplementary heating devices. Detailed measurements were taken in the substations, including the electricity demand of the supplementary heating devices. To compare the energy and economic...

  7. Water temperature affects life-cycle duration of tadpoles of Natal ...

    African Journals Online (AJOL)

    Direct and indirect effects of climate change on amphibians include range shifts and changes in community structure. The Natal cascade frog Hadromophryne natalensis has an altitudinal range of some 2 400 m in KwaZulu-Natal, and presents an opportunity to assess how increased water temperatures may impact on ...

  8. Temperature dependence of the absorption coefficient of water for midinfrared laser radiation

    NARCIS (Netherlands)

    Jansen, E. D.; van Leeuwen, T. G.; Motamedi, M.; Borst, C.; Welch, A. J.

    1994-01-01

    The dynamics of the water absorption peak around 1.94 microns was examined. This peak is important for the absorption of holmium and thulium laser radiation. To examine the effect of temperature on the absorption coefficient, the transmission of pulsed Ho:YAG, Ho:YAG, Ho:YSGG, and Tm:YAG laser

  9. Gold-Catalyzed Aerobic Oxidation of 5-Hydroxymethylfurfural in Water at Ambient Temperature

    DEFF Research Database (Denmark)

    Gorbanev, Yury; Kegnæs, Søren; Woodley, John

    2009-01-01

    The aerobic oxidation of 5-hydroxymethylfurfural, a versatile biomass-derived chemical, is examined in water with a titania-supported gold-nanoparticle catalyst at ambient temperature (30 degrees C). The selectivity of the reaction towords 2,5-furandicarboxylic acid and the intermediate oxidation...

  10. Effects of elevated water temperature on physiological responses in adult freshwater mussels

    Science.gov (United States)

    Ganser, Alissa M.; Newton, Teresa J.; Haro, Roger J.

    2015-01-01

    Freshwater mussels (order Unionoida) face multiple environmental stressors, which pose serious conservation challenges to this diverse assemblage of aquatic invertebrates. Of these stressors, elevated water temperature from global climate change and other anthropogenic sources may be the most ubiquitous and could be placing many mussel populations dangerously close to their thermal maxima.

  11. Comparing Temperature Effects on E. Coli, Salmonella, and Enterococcus Survival in Surface Waters

    Science.gov (United States)

    The objective of this study was to compare dependency of survival rates on temperature for indicator organisms E. coli and Enterococcus and the pathogen Salmonella in surface waters. A database of 86 survival datasets from peer-reviewed papers on inactivation of E. coli, Salmonel...

  12. Effect of temperature on anaerobic treatment of black water in UASB-septic tank systems.

    Science.gov (United States)

    Luostarinen, Sari; Sanders, Wendy; Kujawa-Roeleveld, Katarzyna; Zeeman, Grietje

    2007-03-01

    The effect of northern European seasonal temperature changes and low temperature on the performance of upflow anaerobic sludge blanket (UASB)-septic tanks treating black water was studied. Three UASB-septic tanks were monitored with different operational parameters and at different temperatures. The results indicated the feasibility of the UASB-septic tank for (pre)treatment of black water at low temperatures with respect to removal of suspended solids and dissolved organic material. Inoculum sludge had little effect on COD(ss) removal, though in the start-up phase some poorly adapted inoculum disintegrated and washed out, thus requiring consideration when designing the process. Removal of COD(dis) was at first negative, but improved as the sludge adapted to low temperature. The UASB-septic tank alone did not comply with Finnish or Dutch treatment requirements and should therefore be considered mainly as a pre-treatment method. However, measuring the requirements as mgCOD l(-1) may not always be the best method, as the volume of the effluent discharged is also an important factor in the final amount of COD entering the receiving water bodies.

  13. Temperature dependence of the calibration factor of radon and radium determination in water samples by SSNTD

    CERN Document Server

    Hunyadi, I; Hakl, J; Baradacs, E; Dezso, Z

    1999-01-01

    The sensitivity of a sup 2 sup 2 sup 6 Ra determination method of water samples by SSNTD was measured as a function of storage temperature during exposure. The method is based on an etched track type radon monitor, which is closed into a gas permeable foil and is immersed in the water sample. The sample is sealed in a glass vessel and stored for an exposure time of 10-30 days. The sensitivity increased more than a factor of two when the storage temperature was raised from 2 deg. C to 30 deg. C. Temperature dependence of the partition coefficient of radon between water and air provides explanation for this dependence. For practical radio- analytical application the temperature dependence of the calibration factor is given by fitting the sensitivity data obtained by measuring sup 2 sup 2 sup 6 Ra standard solutions (in the activity concentration range of 0.1-48.5 kBq m sup - sup 3) at different storage temperatures.

  14. Elevated service water temperature systems analysis for a nuclear power plant

    International Nuclear Information System (INIS)

    Lewis, T.; Hurt, W.

    1992-01-01

    This paper describes analyses performed to support the evaluation of the effects of elevated Service Water (SW) temperatures on the operation of a Pressurized Water Reactor. The purpose of the analyses is to provide justification of continued plant operation with SW temperatures up to 5 degrees F (3 degrees C) above the original temperature design limit. The study involved evaluation of the following major components or plant transients: Containment Design Basis Accident (DBA), Emergency Diesel Generator (EDG), Plant Cooldown, Engineered Safety Feature (ESF) Room Coolers, Engineered Safety Feature Pumps, and Assessment for Impact on Normal Operation. The principal objective was related to raising the design maximum temperature of the SW system from 95 degrees F (35 degrees C) to 100 degrees F (38 degrees C). since the Service Water system is safety related, an serves a plant during both normal and design basis conditions, a wide variety of components must be analyzed under various operating modes. The evaluation of systems and components affected by elevated SW temperature is presented, along with conclusions

  15. Continuous Water Vapor Mass Flux and Temperature Measurements in a Model Scramjet Comb