WorldWideScience

Sample records for convective systems final

  1. Convective heat exposure from large fires to the final filters of ventilation systems

    International Nuclear Information System (INIS)

    Alvares, N.J.

    1979-01-01

    The Fire Science Group of the Hazards Control Department, Lawrence Livermore Laboratory has been asked to design a probable fire scenario for a fuel-pellet fabrication facility. This model was used to estimate the potential for thermal damage to the final HEPA filters. These filters would not experience direct fire exposure because they are the last component of the ventilation system before the exhaust air pumps. However, they would be exposed to hot air and fire gases that are drawn into the ventilation system. Because fire is one of the few occurrences that can defeat the containment integrity of facilities where radioactive materials are stored and processed, the fire scenarios must be defined to ensure that containment systems are adequate to meet the threat of such events. Fire-growth calculations are based on the measured fuel load of materials within the fabrication enclosure and on semi-empirical fire-spread models. It is assumed that the fire never becomes ventilation controlled. The temperature rise of ceiling gases and heat transfer from ventilation ducting are calculated using accepted empirical relationships, and the analysis shows that even under the most severe exposure conditions, heat transfer from the duct reduces the fire gas temperatures to levels that would not hamper filter function

  2. Convective Radio Occultations Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Biondi, R. [Atmospheric Radiation Measurement, Washington, DC (United States)

    2016-03-01

    Deep convective systems are destructive weather phenomena that annually cause many deaths and injuries as well as much damage, thereby accounting for major economic losses in several countries. The number and intensity of such phenomena have increased over the last decades in some areas of the globe. Damage is mostly caused by strong winds and heavy rain parameters that are strongly connected to the structure of the particular storm. Convection over land is usually stronger and deeper than over the ocean and some convective systems, known as supercells, also develop tornadoes through processes that remain mostly unclear. The intensity forecast and monitoring of convective systems is one of the major challenges for meteorology because in situ measurements during extreme events are too sparse or unreliable and most ongoing satellite missions do not provide suitable time/space coverage.

  3. Study of plasma convection and wall interactions in magnetic confinement systems. Final report, December 1, 1984-February 28, 1986

    International Nuclear Information System (INIS)

    York, T.M.

    1986-01-01

    The subject contract research effort was initiated in September 1976 with two specific tasks: (1) to study the fundamental physics of confinement of an alternate concept (i.e., theta pinch based) devices; and (2) to study and to develop new diagnostic systems for use on major experiments at other locations in the country. There has been active collaboration with Los Alamos National Laboratory and Lawrence Livermore National Laboratory; there has been proposed collaboration with Princeton Plasma Physics Laboratory, Fusion Research Center at the University of Texas, and General Atomics

  4. Boundary Layer Control of Rotating Convection Systems

    Science.gov (United States)

    King, E. M.; Stellmach, S.; Noir, J.; Hansen, U.; Aurnou, J. M.

    2008-12-01

    Rotating convection is ubiquitous in the natural universe, and is likely responsible for planetary processes such magnetic field generation. Rapidly rotating convection is typically organized by the Coriolis force into tall, thin, coherent convection columns which are aligned with the axis of rotation. This organizational effect of rotation is thought to be responsible for the strength and structure of magnetic fields generated by convecting planetary interiors. As thermal forcing is increased, the relative influence of rotation weakens, and fully three-dimensional convection can exist. It has long been assumed that rotational effects will dominate convection dynamics when the ratio of buoyancy to the Coriolis force, the convective Rossby number, Roc, is less than unity. We investigate the influence of rotation on turbulent Rayleigh-Benard convection via a suite of coupled laboratory and numerical experiments over a broad parameter range: Rayleigh number, 10310; Ekman number, 10-6≤ E ≤ ∞; and Prandtl number, 1≤ Pr ≤ 100. In particular, we measure heat transfer (as characterized by the Nusselt number, Nu) as a function of the Rayleigh number for several different Ekman and Prandtl numbers. Two distinct heat transfer scaling regimes are identified: non-rotating style heat transfer, Nu ~ Ra2/7, and quasigeostrophic style heat transfer, Nu~ Ra6/5. The transition between the non-rotating regime and the rotationally dominant regime is described as a function of the Ekman number, E. We show that the regime transition depends not on the global force balance Roc, but on the relative thicknesses of the thermal and Ekman boundary layers. The transition scaling provides a predictive criterion for the applicability of convection models to natural systems such as Earth's core.

  5. Presentation on Tropical Mesoscale convective Systems and ...

    Indian Academy of Sciences (India)

    IAS Admin

    Shallow convection- 70% of the storm heights are below 6 km. ♢ Deep convection ... Decay convection, the convective top is found at a higher altitude than deep .... Stratospheric Fountain – Two step process. Warm tropopause- preferable for.

  6. Force convective solar drying system

    International Nuclear Information System (INIS)

    Ruslan, M.H.; Othman, M.Y.; Baharuddin Yatim; Kamaruzzaman Sopian; Ibarahim, Z.

    2006-01-01

    This paper presents design and performance of V-groove back-pass solar collector for solar drying system. In this study three V-groove back-pass solar collector each with dimension of 4.6 m x 1.0 m x 0.15 m have been fabricated for solar drying system. An outdoor test at mean solar intensity for 600-800 Wm -2 by using 0.15m 3 s -1 of air flow rate which also been suggested by (Zeroul et al. 1994) was carried out at Solar Research Energy Park. Universiti Kebangsaan Malaysia. Analysis on the collector performance based on daily data was reported that the value of FR ) e and FRUL was 0.709 ± 0.001 and 5.89 ± 0.31 Wm -2o C -1 respectively with 60-70 o C of output temperature (Ruslan et al. 2001). The three V-groove collectors each with dimension 4.6 m x 0.15 m were connected in series array mounted on the roof of a solar assisted drying system. By using two electric fans of 85W and 2700 rpm each, the speed of air was regulated at 0.11 kgs -1 to 0.31 kgs -1 using a voltage regulator. Performance of the collector based on the thermal analysis showed that at mean daily solar radiation 700 Wm -2 , the output temperature of 52 o C to 73 o C could be achieved using 0.11-0.31 kgs -1 of flow rate. Thermal analysis also showed that the efficiencies of 45% to 61% could be obtains using the same flow rate and solar radiation. Analysis of daily data showed that for radiation from 300 Wm -2 to 1000 Wm -2 the power generated from the collector was within 1.5 kW to 8.9 kW. The study concluded that the levels of the levels of the solar radiation and flow rate used influenced the performance of the collector

  7. Land surface sensitivity of mesoscale convective systems

    Science.gov (United States)

    Tournay, Robert C.

    Mesoscale convective systems (MCSs) are important contributors to the hydrologic cycle in many regions of the world as well as major sources of severe weather. MCSs continue to challenge forecasters and researchers alike, arising from difficulties in understanding system initiation, propagation, and demise. One distinct type of MCS is that formed from individual convective cells initiated primarily by daytime heating over high terrain. This work is aimed at improving our understanding of the land surface sensitivity of this class of MCS in the contiguous United States. First, a climatology of mesoscale convective systems originating in the Rocky Mountains and adjacent high plains from Wyoming southward to New Mexico is developed through a combination of objective and subjective methods. This class of MCS is most important, in terms of total warm season precipitation, in the 500 to 1300m elevations of the Great Plains (GP) to the east in eastern Colorado to central Nebraska and northwest Kansas. Examining MCSs by longevity, short lasting MCSs (15 hrs) reveals that longer lasting systems tend to form further south and have a longer track with a more southerly track. The environment into which the MCS is moving showed differences across commonly used variables in convection forecasting, with some variables showing more favorable conditions throughout (convective inhibition, 0-6 km shear and 250 hPa wind speed) ahead of longer lasting MCSs. Other variables, such as convective available potential energy, showed improving conditions through time for longer lasting MCSs. Some variables showed no difference across longevity of MCS (precipitable water and large-scale vertical motion). From subsets of this MCS climatology, three regions of origin were chosen based on the presence of ridgelines extending eastward from the Rocky Mountains known to be foci for convection initiation and subsequent MCS formation: Southern Wyoming (Cheyenne Ridge), Colorado (Palmer divide) and

  8. Ignition in Convective-Diffusive Systems

    National Research Council Canada - National Science Library

    Law, Chung

    1999-01-01

    ... efficiency as well as the knock and emission characteristics. The ignition event is clearly controlled by the chemical reactions of fuel oxidation and the fluid mechanics of convective and diffusive transport...

  9. Convective heat and mass transfer in rotating disk systems

    CERN Document Server

    Shevchuk, Igor V

    2009-01-01

    The book describes results of investigations of a series of convective heat and mass transfer problems in rotating-disk systems. Methodology used included integral methods, self-similar and approximate analytical solutions, as well as CFD.

  10. Vertical Transport by Coastal Mesoscale Convective Systems

    Science.gov (United States)

    Lombardo, K.; Kading, T.

    2016-12-01

    This work is part of an ongoing investigation of coastal mesoscale convective systems (MCSs), including changes in vertical transport of boundary layer air by storms moving from inland to offshore. The density of a storm's cold pool versus that of the offshore marine atmospheric boundary layer (MABL), in part, determines the ability of the storm to successfully cross the coast, the mechanism driving storm propagation, and the ability of the storm to lift air from the boundary layer aloft. The ability of an MCS to overturn boundary layer air can be especially important over the eastern US seaboard, where warm season coastal MCSs are relatively common and where large coastal population centers generate concentrated regions of pollution. Recent work numerically simulating idealized MCSs in a coastal environment has provided some insight into the physical mechanisms governing MCS coastal crossing success and the impact on vertical transport of boundary layer air. Storms are simulated using a cloud resolving model initialized with atmospheric conditions representative of a Mid-Atlantic environment. Simulations are run in 2-D at 250 m horizontal resolution with a vertical resolution stretched from 100 m in the boundary layer to 250 m aloft. The left half of the 800 km domain is configured to represent land, while the right half is assigned as water. Sensitivity experiments are conducted to quantify the influence of varying MABL structure on MCS coastal crossing success and air transport, with MABL values representative of those observed over the western Mid-Atlantic during warm season. Preliminary results indicate that when the density of the cold pool is much greater than the MABL, the storm successfully crosses the coastline, with lifting of surface parcels, which ascend through the troposphere. When the density of the cold pool is similar to that of the MABL, parcels within the MABL remain at low levels, though parcels above the MABL ascend through the troposphere.

  11. Environmental Characteristics of Convective Systems During TRMM-LBA

    Science.gov (United States)

    Halverson, Jeffrey B.; Rickenbach, Thomas; Roy, Biswadev; Pierce, Harold; Williams, Earle; Einaudi, Franco (Technical Monitor)

    2001-01-01

    In this paper, data collected from 51 days of continual upper atmospheric soundings and TOGA radar at ABRACOS Hill during the TRMM-LBA experiment are used to describe the mean thermodynamic and kinematic airmass properties of wet season convection over Rondonia, Brazil. Distinct multi-day easterly and westerly lower tropospheric wind regimes occurred during the campaign with contrasting airmass characteristics. Westerly wind periods featured modest CAPE (1000 J/kg), moist conditions (>90% RH) extending through 700 mb and shallow (900 mb) speed shear on the order of 10(exp -4)/s. This combination of characteristics promoted convective systems that featured a relatively large fraction of stratiform rainfall and weak convection nearly devoid of lightning. The environment is very similar to the general airmass conditions experienced during the Darwin, Australia monsoon convective regime. In contrast, easterly regime convective systems were more strongly electrified and featured larger convective rain rates and reduced stratiform rainfall fraction. These systems formed in an environment with significantly larger CAPE (1500 J/kg), drier lower and middle level humidities (in the lowest 1-2 km, thus contributing to a more explosive growth of convection. The time series of low- and mid-level averaged humidity exhibited marked variability between westerly and easterly regimes and was characterized by low frequency (i.e., multi-day to weekly) oscillations. The synoptic scale origins of these moisture fluctuations are examined, which include the effects of variable low-level airmass trajectories and upper-level, westward migrating cyclonic vortices. The results reported herein provide an environmental context for ongoing dual Doppler analyses and numerical modeling case studies of individual TRMM-LBA convective systems.

  12. Development of a parameterization scheme of mesoscale convective systems

    International Nuclear Information System (INIS)

    Cotton, W.R.

    1994-01-01

    The goal of this research is to develop a parameterization scheme of mesoscale convective systems (MCS) including diabatic heating, moisture and momentum transports, cloud formation, and precipitation. The approach is to: Perform explicit cloud-resolving simulation of MCSs; Perform statistical analyses of simulated MCSs to assist in fabricating a parameterization, calibrating coefficients, etc.; Test the parameterization scheme against independent field data measurements and in numerical weather prediction (NWP) models emulating general circulation model (GCM) grid resolution. Thus far we have formulated, calibrated, implemented and tested a deep convective engine against explicit Florida sea breeze convection and in coarse-grid regional simulations of mid-latitude and tropical MCSs. Several explicit simulations of MCSs have been completed, and several other are in progress. Analysis code is being written and run on the explicitly simulated data

  13. Wavelet Scale Analysis of Mesoscale Convective Systems for Detecting Deep Convection From Infrared Imagery

    Science.gov (United States)

    Klein, Cornelia; Belušić, Danijel; Taylor, Christopher M.

    2018-03-01

    Mesoscale convective systems (MCSs) are frequently associated with rainfall extremes and are expected to further intensify under global warming. However, despite the significant impact of such extreme events, the dominant processes favoring their occurrence are still under debate. Meteosat geostationary satellites provide unique long-term subhourly records of cloud top temperatures, allowing to track changes in MCS structures that could be linked to rainfall intensification. Focusing on West Africa, we show that Meteosat cloud top temperatures are a useful proxy for rainfall intensities, as derived from snapshots from the Tropical Rainfall Measuring Mission 2A25 product: MCSs larger than 15,000 km2 at a temperature threshold of -40°C are found to produce 91% of all extreme rainfall occurrences in the study region, with 80% of the storms producing extreme rain when their minimum temperature drops below -80°C. Furthermore, we present a new method based on 2-D continuous wavelet transform to explore the relationship between cloud top temperature and rainfall intensity for subcloud features at different length scales. The method shows great potential for separating convective and stratiform cloud parts when combining information on temperature and scale, improving the common approach of using a temperature threshold only. We find that below -80°C, every fifth pixel is associated with deep convection. This frequency is doubled when looking at subcloud features smaller than 35 km. Scale analysis of subcloud features can thus help to better exploit cloud top temperature data sets, which provide much more spatiotemporal detail of MCS characteristics than available rainfall data sets alone.

  14. Cosmological Final Focus Systems

    International Nuclear Information System (INIS)

    Irwin, J

    2004-01-01

    We develop the many striking parallels between the dynamics of light streams from distant galaxies and particle beams in accelerator final focus systems. Notably the deflections of light by mass clumps are identical to the kicks arising from the long-range beam-beam interactions of two counter-rotating particle beams (known as parasitic crossings). These deflections have sextupolar as well as quadrupolar components. We estimate the strength of such distortions for a variety of circumstances and argue that the sextupolar distortions from clumping within clusters may be observable. This possibility is enhanced by the facts that (1) the sextupolar distortions of background galaxies is a factor of 5 smaller than the quadrupolar distortion, (2) the angular orientation of the sextupolar and quadrupolar distortions from a mass distribution would be correlated, appearing as a slightly curved image, (3) these effects should be spatially clumped on the sky

  15. Burnout in boiling heat transfer. Part III. High-quality forced-convection systems

    International Nuclear Information System (INIS)

    Bergles, A.E.

    1979-01-01

    This is the final part of a review of burnout during boiling heat transfer. The status of burnout in high-quality forced-convection systems is reviewed, and recent developments are summarized in detail. A general guide to the considerable literature is given. Parametric effects and correlations for water in circular and noncircular ducts are presented. Other topics discussed include transients, steam-generator applications, correlations for other fluids, fouling, and augmentation

  16. Mobile Disdrometer Observations of Nocturnal Mesoscale Convective Systems During PECAN

    Science.gov (United States)

    Bodine, D. J.; Rasmussen, K. L.

    2015-12-01

    Understanding microphysical processes in nocturnal mesoscale convective systems (MCSs) is an important objective of the Plains Elevated Convection At Night (PECAN) experiment, which occurred from 1 June - 15 July 2015 in the central Great Plains region of the United States. Observations of MCSs were collected using a large array of mobile and fixed instrumentation, including ground-based radars, soundings, PECAN Integrated Sounding Arrays (PISAs), and aircraft. In addition to these observations, three mobile Parsivel disdrometers were deployed to obtain drop-size distribution (DSD) measurements to further explore microphysical processes in convective and stratiform regions of nocturnal MCSs. Disdrometers were deployed within close range of a multiple frequency network of mobile and fixed dual-polarization radars (5 - 30 km range), and near mobile sounding units and PISAs. Using mobile disdrometer and multiple-wavelength, dual-polarization radar data, microphysical properties of convective and stratiform regions of MCSs are investigated. The analysis will also examine coordinated Range-Height Indicator (RHI) scans over the disdrometers to elucidate vertical DSD structure. Analysis of dense observations obtained during PECAN in combination with mobile disdrometer DSD measurements contributes to a greater understanding of the structural characteristics and evolution of nocturnal MCSs.

  17. A Generalized Evolution Criterion in Nonequilibrium Convective Systems

    Science.gov (United States)

    Ichiyanagi, Masakazu; Nisizima, Kunisuke

    1989-04-01

    A general evolution criterion, applicable to transport processes such as the conduction of heat and mass diffusion, is obtained as a direct version of the Le Chatelier-Braun principle for stationary states. The present theory is not based on any radical departure from the conventional one. The generalized theory is made determinate by proposing the balance equations for extensive thermodynamic variables which will reflect the character of convective systems under the assumption of local equilibrium. As a consequence of the introduction of source terms in the balance equations, there appear additional terms in the expression of the local entropy production, which are bilinear in terms of the intensive variables and the sources. In the present paper, we show that we can construct a dissipation function for such general cases, in which the premises of the Glansdorff-Prigogine theory are accumulated. The new dissipation function permits us to formulate a generalized evolution criterion for convective systems.

  18. Dry storage systems with free convection air cooling

    International Nuclear Information System (INIS)

    Kioes, S.R.

    1980-01-01

    Several design principles to remove heat from the spent fuel by free air convection are illustrated and described. The key safety considerations were felt to be: loss of coolant is impossible as the passive system uses air as a coolant; overheating is precluded because as the temperatures of the containers rises the coolant flow rate increases; mass of the storage building provides a large heat sink and therefore a rapid temperature rise is impossible; and lack of any active external support requirements makes the cooling process less likely to equipment or operator failures. An example of this type of storage already exists. The German HTGR is operated with spherical graphite fuel elements which are stored in canister and in storage cells. The concept is a double cooling system with free convection inside the cells and heat exchange via two side walls of the cell to the ambient air in the cooling ducts. Technical description of the TN 1300 cask is also presented

  19. Lightning characteristics of derecho producing mesoscale convective systems

    Science.gov (United States)

    Bentley, Mace L.; Franks, John R.; Suranovic, Katelyn R.; Barbachem, Brent; Cannon, Declan; Cooper, Stonie R.

    2016-06-01

    Derechos, or widespread, convectively induced wind storms, are a common warm season phenomenon in the Central and Eastern United States. These damaging and severe weather events are known to sweep quickly across large spatial regions of more than 400 km and produce wind speeds exceeding 121 km h-1. Although extensive research concerning derechos and their parent mesoscale convective systems already exists, there have been few investigations of the spatial and temporal distribution of associated cloud-to-ground lightning with these events. This study analyzes twenty warm season (May through August) derecho events between 2003 and 2013 in an effort to discern their lightning characteristics. Data used in the study included cloud-to-ground flash data derived from the National Lightning Detection Network, WSR-88D imagery from the University Corporation for Atmospheric Research, and damaging wind report data obtained from the Storm Prediction Center. A spatial and temporal analysis was conducted by incorporating these data into a geographic information system to determine the distribution and lightning characteristics of the environments of derecho producing mesoscale convective systems. Primary foci of this research include: (1) finding the approximate size of the lightning activity region for individual and combined event(s); (2) determining the intensity of each event by examining the density and polarity of lightning flashes; (3) locating areas of highest lightning flash density; and (4) to provide a lightning spatial analysis that outlines the temporal and spatial distribution of flash activity for particularly strong derecho producing thunderstorm episodes.

  20. Tropical continental downdraft characteristics: mesoscale systems versus unorganized convection

    Science.gov (United States)

    Schiro, Kathleen A.; Neelin, J. David

    2018-02-01

    Downdrafts and cold pool characteristics for strong mesoscale convective systems (MCSs) and isolated, unorganized deep precipitating convection are analyzed using multi-instrument data from the DOE Atmospheric Radiation Measurement (ARM) GoAmazon2014/5 campaign. Increases in column water vapor (CWV) are observed leading convection, with higher CWV preceding MCSs than for isolated cells. For both MCSs and isolated cells, increases in wind speed, decreases in surface moisture and temperature, and increases in relative humidity occur coincidentally with system passages. Composites of vertical velocity data and radar reflectivity from a radar wind profiler show that the downdrafts associated with the sharpest decreases in surface equivalent potential temperature (θe) have a probability of occurrence that increases with decreasing height below the freezing level. Both MCSs and unorganized convection show similar mean downdraft magnitudes and probabilities with height. Mixing computations suggest that, on average, air originating at heights greater than 3 km must undergo substantial mixing, particularly in the case of isolated cells, to match the observed cold pool θe, implying a low typical origin level. Precipitation conditionally averaged on decreases in surface equivalent potential temperature (Δθe) exhibits a strong relationship because the most negative Δθe values are associated with a high probability of precipitation. The more physically motivated conditional average of Δθe on precipitation shows that decreases in θe level off with increasing precipitation rate, bounded by the maximum difference between surface θe and its minimum in the profile aloft. Robustness of these statistics observed across scales and regions suggests their potential use as model diagnostic tools for the improvement of downdraft parameterizations in climate models.

  1. Magnetospheric convection and current system in the dayside polar cap

    International Nuclear Information System (INIS)

    Nishida, A.; Mukai, T.; Tsuruda, K.; Hayakawa, H.

    1992-01-01

    Field and particle observations on EXOS-D (Akebono) have yielded new information on convection and current system in the dayside polar cap. Convection patterns are distinctly different depending upon whether IMF B z is northward or southward. The number of convection cells is two when B z is southward but four when B z is northward. Lobe cells in which plasma flows sunward in the region of open field lines are observed as a pair (of which one is in the dawn and the other in the dusk sector) for any polarity of IMF B y and B z . Ions in the keV range precipitate not only in the dayside cusp region but also along the sunward directed streamlines of the dawn and dusk lobe cells. These observations require reconsideration on the position and the extent of the reconnection region on the magnetopause. They also suggest that the magnetotail plays a vital role in some phenomena which have been ascribed to dayside magnetopause processes. We have not been able to find evidence to prove the presence of the viscous cell under southward IMF

  2. Numerical modeling of a downwind-developing mesoscale convective system over the Masurian Lake District

    Directory of Open Access Journals (Sweden)

    Wójcik Damian K.

    2017-01-01

    Full Text Available Meteorological data concerning the severe convective system from the 21 August 2007 are analyzed in this study. Compiled information allows to understand the reason for the storm development and to identify its fundamental convective mode. Next, the EULAG model is utilized to perform an idealized test that shows a downwind–developing storm growth in an environment comparable to the one that was observed on the 21 August 2007 in the Masurian Lake District. Finally, the COSMO numerical weather prediction model is applied to reconstruct the storm development. The experiment is carried out for various computational grids having the horizontal grid length between 7.0 and 0.55 km. It turns out that the COSMO model is capable in simulating storms of that type. Since the model is used for operational weather forecasting in Poland the evaluation of this skill contributes to the increase of public safety.

  3. Convective Performance of Nanofluids in Commercial Electronics Cooling Systems

    International Nuclear Information System (INIS)

    Roberts, N.A.; Walker, D.G.

    2010-01-01

    Nanofluids are stable engineered colloidal suspensions of a small fraction of nanoparticles in a base fluid. Nanofluids have shown great promise as heat transfer fluids over typically used base fluids and fluids with micron sized particles. Suspensions with micron sized particles are known to settle rapidly and cause clogging and damage to the surfaces of pumping and flow equipment. These problems are dramatically reduced in nanofluids. In the current work we investigate the performance of different volume loadings of water-based alumina nanofluids in a commercially available electronics cooling system. The commercially available system is a water block used for liquid cooling of a computational processing unit. The size of the nanoparticles in the study is 20-30 nm. Results show an enhancement in convective heat transfer due to the addition of nanoparticles in the commercial cooling system with volume loadings of nanoparticles up to 1.5% by volume. The enhancement in the convective performance observed is similar to what has been reported in well controlled and understood systems and is commensurate with bulk models. The current nanoparticle suspensions showed visible signs of settling which varied from hours to weeks depending on the size of the particles used.

  4. Impairment of Heat Transfer in the Passive Cooling System due to Mixed Convection

    Energy Technology Data Exchange (ETDEWEB)

    Chae Myeong Seon; Chung, Bum Jin [Kyunghee University, Yongin (Korea, Republic of); Kim, Jong Hwan [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In the passive cooling devices, the buoyant flows are induced. However the local Nusselt number of natural convective flow can be partly impaired due to the development of the mixed convective flows. This paper discusses impairment of heat transfer in the passive cooling system in relation to the development of mixed convection. The present work describes the preliminary plan to explore the phenomena experimentally. This paper is to discuss and make the plan to experiment the impairment of heat transfer in the passive cooling system due to mixed convection. In the sufficiently high passive cooling devices, the natural convection flow behavior can be mixed convection. The local Nusselt number distribution exhibits the non-monotonic behavior as axial position, since the buoyancy-aided with mixed convection was appeared. This is the part of the experimental work.

  5. Numerical analysis of a natural convection cooling system for radioactive canisters storage

    Energy Technology Data Exchange (ETDEWEB)

    Tsal, R.J.; Anwar, S.; Mercada, M.G. [Fluor Daniel Inc., Irvine, CA (United States)

    1995-02-01

    This paper describes the use of numerical analysis for studying natural convection cooling systems for long term storage of heat producing radioactive materials, including special nuclear materials and nuclear waste. The paper explains the major design philosophy, and shares the experiences of numerical modeling. The strategy of storing radioactive material is to immobilize nuclear high-level waste by a vitrification process, convertion it into borosilicate glass, and cast the glass into stainless steel canisters. These canisters are seal welded, decontaminated, inspected, and temporarily stored in an underground vault until they can be sent to a geologic repository for permanent storage. These canisters generate heat by nuclear decay of radioactive isotopes. The function of the storage facility ventilation system is to ensure that the glass centerline temperature does not exceed the glass transition temperature during storage and the vault concrete temperatures remain within the specified limits. A natural convection cooling system was proposed to meet these functions. The effectiveness of a natural convection cooling system is dependent on two major factors that affect air movement through the vault for cooling the canisters: (1) thermal buoyancy forces inside the vault which create a stack effect, and (2) external wind forces, that may assist or oppose airflow through the vault. Several numerical computer models were developed to analyze the thermal and hydraulic regimes in the storage vault. The Site Model is used to simulate the airflow around the building and to analyze different air inlet/outlet devices. The Airflow Model simulates the natural convection, thermal regime, and hydraulic resistance in the vault. The Vault Model, internal vault temperature stratification; and, finally, the Hot Area Model is used for modeling concrete temperatures within the vault.

  6. Analysis and simulation of mesoscale convective systems accompanying heavy rainfall: The goyang case

    Science.gov (United States)

    Choi, Hyun-Young; Ha, Ji-Hyun; Lee, Dong-Kyou; Kuo, Ying-Hwa

    2011-05-01

    We investigated a torrential rainfall case with a daily rainfall amount of 379 mm and a maximum hourly rain rate of 77.5 mm that took place on 12 July 2006 at Goyang in the middlewestern part of the Korean Peninsula. The heavy rainfall was responsible for flash flooding and was highly localized. High-resolution Doppler radar data from 5 radar sites located over central Korea were analyzed. Numerical simulations using the Weather Research and Forecasting (WRF) model were also performed to complement the high-resolution observations and to further investigate the thermodynamic structure and development of the convective system. The grid nudging method using the Global Final (FNL) Analyses data was applied to the coarse model domain (30 km) in order to provide a more realistic and desirable initial and boundary conditions for the nested model domains (10 km, 3.3 km). The mesoscale convective system (MCS) which caused flash flooding was initiated by the strong low level jet (LLJ) at the frontal region of high equivalent potential temperature (θe) near the west coast over the Yellow Sea. The ascending of the warm and moist air was induced dynamically by the LLJ. The convective cells were triggered by small thermal perturbations and abruptly developed by the warm θe inflow. Within the MCS, several convective cells responsible for the rainfall peak at Goyang simultaneously developed with neighboring cells and interacted with each other. Moist absolutely unstable layers (MAULs) were seen at the lower troposphere with the very moist environment adding the instability for the development of the MCS.

  7. Final focus system for TLC

    International Nuclear Information System (INIS)

    Oide, K.

    1988-11-01

    A limit of the chromaticity correction for the final focus system of a TeV Linear Collider (TLC) is investigated. As the result, it becomes possible to increase the aperture of the final doublet with a small increase of the horizontal β function. The new optics design uses a final doublet of 0.5 mm half-aperture and 1.4 T pole-tip field. The length of the system is reduced from 400 m to 200 m by several optics changes. Tolerances for various machine errors with this optics are also studied. 5 refs., 7 figs., 2 tabs

  8. Environments of Long-Lived Mesoscale Convective Systems Over the Central United States in Convection Permitting Climate Simulations: Long-Lived Mesoscale Convective Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qing [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Houze, Robert A. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Department of Atmospheric Sciences, University of Washington, Seattle WA USA; Leung, L. Ruby [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA; Feng, Zhe [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland WA USA

    2017-12-27

    Continental-scale convection-permitting simulations of the warm seasons of 2011 and 2012 reproduce realistic structure and frequency distribution of lifetime and event mean precipitation of mesoscale convective systems (MCSs) over the central United States. Analysis is performed to determine the environmental conditions conducive to generating the longest-lived MCSs and their subsequent interactions. The simulations show that MCSs systematically form over the Great Plains ahead of a trough in the westerlies in combination with an enhanced low-level jet from the Gulf of Mexico. These environmental properties at the time of storm initiation are most prominent for the MCSs that persist for the longest times. Systems reaching 9 h or more in lifetime exhibit feedback to the environment conditions through diabatic heating in the MCS stratiform regions. As a result, the parent synoptic-scale wave is strengthened as a divergent perturbation develops over the MCS at high levels, while a cyclonic circulation perturbation develops in the midlevels of the trough, where the vertical gradient of heating in the MCS region is maximized. The quasi-balanced mesoscale vortex helps to maintain the MCS over a long period of time by feeding dry, cool air into the environment at the rear of the MCS region, so that the MCS can draw in air that increases the evaporative cooling that helps maintain the MCS. At lower levels the south-southeasterly jet of warm moist air from the Gulf is enhanced in the presence of the synoptic-scale wave. That moisture supply is essential to the continued redevelopment of the MCS.

  9. VHF/UHF radar observations of tropical mesoscale convective systems over southern India

    Directory of Open Access Journals (Sweden)

    K. Kishore Kumar

    2005-07-01

    Full Text Available Several campaigns have been carried out to study the convective systems over Gadanki (13.5° N, 79.2° E, a tropical station in India, using VHF and UHF radars. The height-time sections of several convective systems are investigated in detail to study reflectivity, turbulence and vertical velocity structure. Structure and dynamics of the convective systems are the main objectives of these campaigns. The observed systems are classified into single- and multi-cell systems. It has been observed that most of the convective systems at this latitude are multi-cellular in nature. Simultaneous VHF and UHF radar observations are used to classify the observed precipitating systems as convective, intermediary and stratiform regions. Composite height profiles of vertical velocities in these regions were obtained and the same were compared with the profiles obtained at other geographical locations. These composite profiles of vertical velocity in the convective regions have shown their peaks in the mid troposphere, indicating that the maximum latent heat is being released at those heights. These profiles are very important for numerical simulations of the convective systems, which vary significantly from one geographical location to the other.

    Keywords. Meteorology and atmospheric dynamics (Mesoscale meteorology; Convective processes – Radio science (Remote sensing

  10. VHF/UHF radar observations of tropical mesoscale convective systems over southern India

    Directory of Open Access Journals (Sweden)

    K. Kishore Kumar

    2005-07-01

    Full Text Available Several campaigns have been carried out to study the convective systems over Gadanki (13.5° N, 79.2° E, a tropical station in India, using VHF and UHF radars. The height-time sections of several convective systems are investigated in detail to study reflectivity, turbulence and vertical velocity structure. Structure and dynamics of the convective systems are the main objectives of these campaigns. The observed systems are classified into single- and multi-cell systems. It has been observed that most of the convective systems at this latitude are multi-cellular in nature. Simultaneous VHF and UHF radar observations are used to classify the observed precipitating systems as convective, intermediary and stratiform regions. Composite height profiles of vertical velocities in these regions were obtained and the same were compared with the profiles obtained at other geographical locations. These composite profiles of vertical velocity in the convective regions have shown their peaks in the mid troposphere, indicating that the maximum latent heat is being released at those heights. These profiles are very important for numerical simulations of the convective systems, which vary significantly from one geographical location to the other. Keywords. Meteorology and atmospheric dynamics (Mesoscale meteorology; Convective processes – Radio science (Remote sensing

  11. Estimation and prediction of convection-diffusion-reaction systems from point measurement

    NARCIS (Netherlands)

    Vries, D.

    2008-01-01

    Different procedures with respect to estimation and prediction of systems characterized by convection, diffusion and reactions on the basis of point measurement data, have been studied. Two applications of these convection-diffusion-reaction (CDR) systems have been used as a case study of the

  12. Experimental investigation of natural convection heat transfer in volumetrically heated spherical segments. Final report

    International Nuclear Information System (INIS)

    Asfia, F.; Dhir, V.

    1998-03-01

    One strategy for preventing the failure of lower head of a nuclear reactor vessel is to flood the concrete cavity with subcooled water in accidents in which relocation of core material into the vessel lower head occurs. After the core material relocates into the vessel, a crust of solid material forms on the inner wall of the vessel, however, most of the pool remains molten and natural convection exists in the pool. At present, uncertainty exists with respect to natural convection heat transfer coefficients between the pool of molten core material and the reactor vessel wall. In the present work, experiments were conducted to examine natural convection heat transfer in internally heated partially filled spherical pools with external cooling. In the experiments, Freon-113 contained in a Pyrex bell jar was used as a test liquid. The pool was bounded with a spherical segment at the bottom, and was heated with magnetrons taken from a conventional microwave oven. The vessel was cooled from the outside with natural convection of water or with nucleate boiling of liquid nitrogen

  13. Explicit simulation of a midlatitude Mesoscale Convective System

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, G.D.; Cotton, W.R. [Colorado State Univ., Fort Collins, CO (United States)

    1996-04-01

    We have explicitly simulated the mesoscale convective system (MCS) observed on 23-24 June 1985 during PRE-STORM, the Preliminary Regional Experiment for the Stormscale Operational and Research and Meterology Program. Stensrud and Maddox (1988), Johnson and Bartels (1992), and Bernstein and Johnson (1994) are among the researchers who have investigated various aspects of this MCS event. We have performed this MCS simulation (and a similar one of a tropical MCS; Alexander and Cotton 1994) in the spirit of the Global Energy and Water Cycle Experiment Cloud Systems Study (GCSS), in which cloud-resolving models are used to assist in the formulation and testing of cloud parameterization schemes for larger-scale models. In this paper, we describe (1) the nature of our 23-24 June MCS dimulation and (2) our efforts to date in using our explicit MCS simulations to assist in the development of a GCM parameterization for mesoscale flow branches. The paper is organized as follows. First, we discuss the synoptic situation surrounding the 23-24 June PRE-STORM MCS followed by a discussion of the model setup and results of our simulation. We then discuss the use of our MCS simulation. We then discuss the use of our MCS simulations in developing a GCM parameterization for mesoscale flow branches and summarize our results.

  14. Evaluation of an assisted convection system for integrated reactors

    International Nuclear Information System (INIS)

    Patruno, Luciano

    2006-01-01

    This work consists of the analyze of changing to an assisted convection system the CAREM-25 nuclear power plant design.The work is focused on the design, construction and measurement of an experimental hydraulic loop which contains a jet pump.There is also a characterization of parameters such as flow rate, hydrostatic pressure, efficiency, velocity profiles and development length using different tools such as theoretical formulations, numeric simulations and experimental data. New set points are found in CAREM thermo hydraulic parameters which take the thermal power to up to 150MW, and the water flow rate to 615 kg/s.To achieve this goals, the use of twelve jet pumps is proposed at a flow rate coefficient of 10.The results on the static pressure provided by the jet pump are calculated theoretically and compared with experimental data.There is an extrapolation of the results to higher flow rate values to be applied to the CAREM-25 design.Concerning the experimental work, the results show a good match on flow rate between the measured data and the theoretical results.There is a reasonable match in the coefficient of flow rate (M), even when the measurement uncertainties are quite high (about 13 %).It is also shown an efficiency measurement, which is up to 14 % [es

  15. Magnetism, planetary rotation and convection in the solar system

    CERN Document Server

    1985-01-01

    On the 6th, 7th' and 8th April 1983, a conference entitled "Magnetism, planetary rotation and convection in the Solar System" was held in the School of Physics at the University of Newcastle upon Tyne. The purpose of the meeting was to celebrate the 60th birthday of Prof. Stanley Keith Runcorn and his, and his students' and associates', several decades of scientific achievement. The social programme, which consisted of excursions in Northumberland and Durham with visits to ancient castles and churches, to Hexham Abbey and Durham Cathedral, and dinners in Newcastle and Durham, was greatly enjoyed by those attending the meeting and by their guests. The success ofthe scientific programme can be judged by this special edition of Geophysical Surveys which is derived mainly from the papers given at the meeting. The story starts in the late 1940s when the question of the origin of the magnetic field of the Earth and such other heavenly bodies as had at that time been discovered as having a magnetic field, was exerci...

  16. Investigating Mesoscale Convective Systems and their Predictability Using Machine Learning

    Science.gov (United States)

    Daher, H.; Duffy, D.; Bowen, M. K.

    2016-12-01

    A mesoscale convective system (MCS) is a thunderstorm region that lasts several hours long and forms near weather fronts and can often develop into tornadoes. Here we seek to answer the question of whether these tornadoes are "predictable" by looking for a defining characteristic(s) separating MCSs that evolve into tornadoes versus those that do not. Using NASA's Modern Era Retrospective-analysis for Research and Applications 2 reanalysis data (M2R12K), we apply several state of the art machine learning techniques to investigate this question. The spatial region examined in this experiment is Tornado Alley in the United States over the peak tornado months. A database containing select variables from M2R12K is created using PostgreSQL. This database is then analyzed using machine learning methods such as Symbolic Aggregate approXimation (SAX) and DBSCAN (an unsupervised density-based data clustering algorithm). The incentive behind using these methods is to mathematically define a MCS so that association rule mining techniques can be used to uncover some sort of signal or teleconnection that will help us forecast which MCSs will result in tornadoes and therefore give society more time to prepare and in turn reduce casualties and destruction.

  17. Dynamical System Analysis of Thermal Convection in a Horizontal Layer of Nanofluids Heated from Below

    Directory of Open Access Journals (Sweden)

    J. M. Jawdat

    2012-01-01

    Full Text Available The effect of nanofluids on chaotic convection in a fluid layer heated from below was studied in this paper for low Prandtl number based on the theory of dynamical systems. A low-dimensional, Lorenz-like model was obtained using Galerkin-truncated approximations. The fourth-order Runge-Kutta method was employed to solve the nonlinear system. The results show that inhibition of chaotic convection can be observed when using nanofluids.

  18. Experimental StudyHigh Altitude Forced Convective Cooling of Electromechanical Actuation Systems

    Science.gov (United States)

    2016-01-01

    34 Massachusetts Institute of Technology , 1989. [3] FedBizOps.Gov, " Integrated Vehicle Energy Technology (INVENT) Development Program for the 6th...AFRL-RQ-WP-TR-2016-0043 EXPERIMENTAL STUDY—HIGH ALTITUDE FORCED CONVECTIVE COOLING OF ELECTROMECHANICAL ACTUATION SYSTEMS Evan M. Racine...TITLE AND SUBTITLE EXPERIMENTAL STUDY—HIGH ALTITUDE FORCED CONVECTIVE COOLING OF ELECTROMECHANICAL ACTUATION SYSTEMS 5a. CONTRACT NUMBER In-house

  19. Sparse identification of a predator-prey system from simulation data of a convection model

    DEFF Research Database (Denmark)

    Dam, Magnus; Brøns, Morten; Rasmussen, Jens Juul

    2017-01-01

    of a convection problem. A convection model with a pressure source centered at the inner boundary models the edge dynamics of a magnetically confined plasma. The convection problem undergoes a sequence of bifurcations as the strength of the pressure source increases. The time evolution of the energies......The use of low-dimensional dynamical systems as reduced models for plasma dynamics is useful as solving an initial value problem requires much less computational resources than fluid simulations. We utilize a data-driven modeling approach to identify a reduced model from simulation data...

  20. Origin of the pre-tropical storm Debby (2006) African easterly wave-mesoscale convective system

    Science.gov (United States)

    Lin, Yuh-Lang; Liu, Liping; Tang, Guoqing; Spinks, James; Jones, Wilson

    2013-05-01

    The origins of the pre-Debby (2006) mesoscale convective system (MCS) and African easterly wave (AEW) and their precursors were traced back to the southwest Arabian Peninsula, Asir Mountains (AS), and Ethiopian Highlands (EH) in the vicinity of the ITCZ using satellite imagery, GFS analysis data and ARW model. The sources of the convective cloud clusters and vorticity perturbations were attributed to the cyclonic convergence of northeasterly Shamal wind and the Somali jet, especially when the Mediterranean High shifted toward east and the Indian Ocean high strengthened and its associated Somali jet penetrated farther to the north. The cyclonic vorticity perturbations were strengthened by the vorticity stretching associated with convective cloud clusters in the genesis region—southwest Arabian Peninsula. A conceptual model was proposed to explain the genesis of convective cloud clusters and cyclonic vorticity perturbations preceding the pre-Debby (2006) AEW-MCS system.

  1. Corrosion in lithium-stainless steel thermal-convection systems

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.; Selle, J.E.

    1980-01-01

    The corrosion of types 304L and 316 austenitic stainless steel by flowing lithium was studied in thermal-convection loops operated at 500 to 650 0 C. Both weight and compositional changes were measured on specimens distributed throughout each loop and were combined with metallographic examinations to evaluate the corrosion processes. The corrosion rate and mass transfer characteristics did not significantly differ between the two austenitic stainless steels. Addition of 500 or 1700 wt ppM N to purified lithium did not increase the dissolution rate or change the attack mode of type 316 stainless steel. Adding 5 wt % Al to the lithium reduced the weight loss of this steel by a factor of 5 relative to a pure lithium-thermal-convection loop

  2. Analysis of Summertime Convective Initiation in Central Alabama Using the Land Information System

    Science.gov (United States)

    James, Robert S.; Case, Jonathan L.; Molthan, Andrew L.; Jedlovec, Gary J.

    2011-01-01

    During the summer months in the southeastern United States, convective initiation presents a frequent challenge to operational forecasters. Thunderstorm development has traditionally been referred to as random due to their disorganized, sporadic appearance and lack of atmospheric forcing. Horizontal variations in land surface characteristics such as soil moisture, soil type, land and vegetation cover could possibly be a focus mechanism for afternoon convection during the summer months. The NASA Land Information System (LIS) provides a stand-alone land surface modeling framework that incorporates these varying soil and vegetation properties, antecedent precipitation, and atmospheric forcing to represent the soil state at high resolution. The use of LIS as a diagnostic tool may help forecasters to identify boundaries in land surface characteristics that could correlate to favored regions of convection initiation. The NASA Shortterm Prediction Research and Transition (SPoRT) team has been collaborating with the National Weather Service Office in Birmingham, AL to help incorporate LIS products into their operational forecasting methods. This paper highlights selected convective case dates from summer 2009 when synoptic forcing was weak, and identifies any boundaries in land surface characteristics that may have contributed to convective initiation. The LIS output depicts the effects of increased sensible heat flux from urban areas on the development of convection, as well as convection along gradients in land surface characteristics and surface sensible and latent heat fluxes. These features may promote mesoscale circulations and/or feedback processes that can either enhance or inhibit convection. With this output previously unavailable to operational forecasters, LIS provides a new tool to forecasters in order to help eliminate the randomness of summertime convective initiation.

  3. Diagnosing the average spatio-temporal impact of convective systems – Part 1: A methodology for evaluating climate models

    Directory of Open Access Journals (Sweden)

    M. S. Johnston

    2013-12-01

    Full Text Available An earlier method to determine the mean response of upper-tropospheric water to localised deep convective systems (DC systems is improved and applied to the EC-Earth climate model. Following Zelinka and Hartmann (2009, several fields related to moist processes and radiation from various satellites are composited with respect to the local maxima in rain rate to determine their spatio-temporal evolution with deep convection in the central Pacific Ocean. Major improvements to the earlier study are the isolation of DC systems in time so as to prevent multiple sampling of the same event, and a revised definition of the mean background state that allows for better characterisation of the DC-system-induced anomalies. The observed DC systems in this study propagate westward at ~4 m s−1. Both the upper-tropospheric relative humidity and the outgoing longwave radiation are substantially perturbed over a broad horizontal extent and for periods >30 h. The cloud fraction anomaly is fairly constant with height but small maximum can be seen around 200 hPa. The cloud ice water content anomaly is mostly confined to pressures greater than 150 hPa and reaches its maximum around 450 hPa, a few hours after the peak convection. Consistent with the large increase in upper-tropospheric cloud ice water content, albedo increases dramatically and persists about 30 h after peak convection. Applying the compositing technique to EC-Earth allows an assessment of the model representation of DC systems. The model captures the large-scale responses, most notably for outgoing longwave radiation, but there are a number of important differences. DC systems appear to propagate eastward in the model, suggesting a strong link to Kelvin waves instead of equatorial Rossby waves. The diurnal cycle in the model is more pronounced and appears to trigger new convection further to the west each time. Finally, the modelled ice water content anomaly peaks at pressures greater than 500 h

  4. Variability of mass-size relationships in tropical Mesoscale Convective Systems

    Science.gov (United States)

    Fontaine, Emmanuel; Leroy, Delphine; Delanoë, Julien; Dupuy, Régis; Lilie, Lyle; Strapp, Walter; Protat, Alain; Schwarzenböeck, Alfons

    2015-04-01

    The mass of individual ice hydrometeors in Mesoscale Convective Systems (MCS) has been investigated in the past using different methods in order to retrieve power law type mass-size relationships m(D) with m = α D^β. This study focuses on the variability of mass-size relationships in different types of MCS. Three types of tropical MCS were sampled during different airborne campaigns: (i) continental MCS during the West African monsoon (Megha-Tropique 2010), (ii) oceanic MCS over the Indian Ocean (Megha-Tropique 2011), and (iii) coastal MCS during the North-Australian monsoon (HAIC-HIWC). Mass-size relationships of ice hydrometeors are derived from a combined analysis of particle images from 2D-array probes and associated reflectivity factors measured with a Doppler cloud radar (94GHz) on the same research aircraft. A theoretical study of numerous hydrometeor shapes simulated in 3D and arbitrarily projected on a 2D plan allowed to constrain the exponent β of the m(D) relationship as a function of the derived surface-diameter relationship S(D), which is likewise written as a power law. Since S(D) always can be determined for real data from 2D optical array probes or other particle imagers, the evolution of the m(D) exponent β can be calculated along the flight trajectory. Then the pre-factor α of m(D) is constrained from theoretical simulations of the radar reflectivity factor matching the measured reflectivity factor along the aircraft trajectory. Finally, the Condensed Water Content (CWC) is deduced from measured particle size distributions (PSD) and retrieved m(D) relationships along the flight trajectory. Solely for the HAIC-HIWC campaign (North Australian Monsoon) a bulk reference measurement (IKP instrument) of high CWC could be performed in order to compare with the above described CWC deduced from ice hydrometeor images and reflectivity factors. Both CWC are coherent. Mean profiles of m(D) coefficients, PSD, and CWC are calculated as a function of the

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

    Science.gov (United States)

    Guo, Weidong; Narayanan, Ranga

    2006-11-01

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

  6. Upper Troposphere Lower Stratosphere structure during convective systems using GPS radio occultations

    DEFF Research Database (Denmark)

    Biondi, Riccardo

    The deep convective systems play a fundamental role in atmospheric circulation and climate. Thunderstorms and meso-scale convective systems produce fast vertical transport, redistributing water vapor and trace gases and influencing the thermal structure of the upper troposphere and lower...... stratosphere (UTLS) contributing to the troposphere-stratosphere transport and affecting the Earth global circulation and the climate changes. The Global Positioning System (GPS) Radio Occultation (RO) technique enables measurement of atmospheric density structure in any meteorological condition...... to the analysis of tropical storms for the future mission ACES will also be evaluated. Using data from the past and ongoing GPS RO missions we have defined an algorithm to detect the clouds top of the convective systems and their thermal structure. Other satellite and in-situ measurements co-located with GPS ROs...

  7. Final Research Performance Progress Report: Geothermal Resource Development with Zero Mass Withdrawal, Engineered Convection, and Wellbore Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Richard [Louisiana State Univ., Baton Rouge, LA (United States); Tyagi, Mayank [Louisiana State Univ., Baton Rouge, LA (United States); Radonjic, Mileva [Louisiana State Univ., Baton Rouge, LA (United States); Dahi, Arash [Louisiana State Univ., Baton Rouge, LA (United States); Wang, Fahui [Louisiana State Univ., Baton Rouge, LA (United States); John, Chacko [Louisiana State Univ., Baton Rouge, LA (United States); Kaiser, Mark [Louisiana State Univ., Baton Rouge, LA (United States); Snyder, Brian [Louisiana State Univ., Baton Rouge, LA (United States); Sears, Stephen [Louisiana State Univ., Baton Rouge, LA (United States)

    2017-07-07

    This project is intended to demonstrate the technical and economic feasibility, and environmental and social attractiveness of a novel method of heat extraction from geothermal reservoirs. The emphasis is on assessing the potential for a heat extraction method that couples forced and free convection to maximize extraction efficiency. The heat extraction concept is enhanced by considering wellbore energy conversion, which may include only a boiler for a working fluid, or perhaps a complete boiler, turbine, and condenser cycle within the wellbore. The feasibility of this system depends on maintaining mechanical and hydraulic integrity of the wellbore, so the material properties of the casing-cement system are examined both experimentally and with well design calculations. The attractiveness depends on mitigation of seismic and subsidence risks, economic performance, environmental impact, and social impact – all of which are assessed as components of this study.

  8. Natural convection liquid desiccant loop as an auxiliary air conditioning system: investigating the operational parameters

    Science.gov (United States)

    Fazilati, Mohammad Ali; Alemrajabi, Ali Akbar; Sedaghat, Ahmad

    2018-03-01

    Liquid desiccant air conditioning system with natural convection was presented previously as a new generation of AC systems. The system consists of two three-fluid energy exchangers namely absorber and regenerator in which the action of air dehumidifying and desiccant regeneration is done, respectively. The influence of working parameters on system performance including the heat source and heat sink temperature, concentration of desiccant solution fills the system initially and humidity content of inlet air to regenerator is investigated experimentally. The heat source temperatures of 50 °C and 60 °C, heat sink temperatures of 15 °C and 20 °C and desiccant concentrations of 30% and 34%, are examined here. The inlet air to regenerator has temperature of 38.5 °C and three relative humidity of 14%, 38% and 44%. In all experiments, the inlet air to absorber has temperature of 31 °C and relative humidity of 75%. By inspecting evaluation indexes of system, it is revealed that higher startup desiccant concentration solution is more beneficial for all study cases. It is also observed although the highest/lowest temperature heat source/heat sink is most suitable for best system operation, increasing the heat source temperature should be accompanied with decreasing heat sink temperature. Using drier air stream for regenerator inlet does not necessarily improve system performance; and the air stream with proper value of humidity content should be employed. Finally after running the system in its best working condition, the coefficient of performance (COP) reached 4.66 which verified to be higher than when the same air conditioning task done by a conventional vapor compression system, in which case the COP was 3.38.

  9. Life Cycle of Midlatitude Deep Convective Systems in a Lagrangian Framework

    Science.gov (United States)

    Feng, Zhe; Dong, Xiquan; Xie, Baike; McFarlane, Sally A.; Kennedy, Aaron; Lin, Bing; Minnis, Patrick

    2012-01-01

    Deep Convective Systems (DCSs) consist of intense convective cores (CC), large stratiform rain (SR) regions, and extensive non-precipitating anvil clouds (AC). This study focuses on the evolution of these three components and the factors that affect convective AC production. An automated satellite tracking method is used in conjunction with a recently developed multi-sensor hybrid classification to analyze the evolution of DCS structure in a Lagrangian framework over the central United States. Composite analysis from 4221 tracked DCSs during two warm seasons (May-August, 2010-2011) shows that maximum system size correlates with lifetime, and longer-lived DCSs have more extensive SR and AC. Maximum SR and AC area lag behind peak convective intensity and the lag increases linearly from approximately 1-hour for short-lived systems to more than 3-hours for long-lived ones. The increased lag, which depends on the convective environment, suggests that changes in the overall diabatic heating structure associated with the transition from CC to SR and AC could prolong the system lifetime by sustaining stratiform cloud development. Longer-lasting systems are associated with up to 60% higher mid-tropospheric relative humidity and up to 40% stronger middle to upper tropospheric wind shear. Regression analysis shows that the areal coverage of thick AC is strongly correlated with the size of CC, updraft strength, and SR area. Ambient upper tropospheric wind speed and wind shear also play an important role for convective AC production where for systems with large AC (radius greater than 120-km) they are 24% and 20% higher, respectively, than those with small AC (radius=20 km).

  10. Convective plasma stability consistent with MHD equilibrium in magnetic confinement systems with a decreasing field

    International Nuclear Information System (INIS)

    Tsventoukh, M. M.

    2010-01-01

    A study is made of the convective (interchange, or flute) plasma stability consistent with equilibrium in magnetic confinement systems with a magnetic field decreasing outward and large curvature of magnetic field lines. Algorithms are developed which calculate convective plasma stability from the Kruskal-Oberman kinetic criterion and in which the convective stability is iteratively consistent with MHD equilibrium for a given pressure and a given type of anisotropy in actual magnetic geometry. Vacuum and equilibrium convectively stable configurations in systems with a decreasing, highly curved magnetic field are calculated. It is shown that, in convectively stable equilibrium, the possibility of achieving high plasma pressures in the central region is restricted either by the expansion of the separatrix (when there are large regions of a weak magnetic field) or by the filamentation of the gradient plasma current (when there are small regions of a weak magnetic field, in which case the pressure drops mainly near the separatrix). It is found that, from the standpoint of equilibrium and of the onset of nonpotential ballooning modes, a kinetic description of convective stability yields better plasma confinement parameters in systems with a decreasing, highly curved magnetic field than a simpler MHD model and makes it possible to substantially improve the confinement parameters for a given type of anisotropy. For the Magnetor experimental compact device, the maximum central pressure consistent with equilibrium and stability is calculated to be as high as β ∼ 30%. It is shown that, for the anisotropy of the distribution function that is typical of a background ECR plasma, the limiting pressure gradient is about two times steeper than that for an isotropic plasma. From a practical point of view, the possibility is demonstrated of achieving better confinement parameters of a hot collisionless plasma in systems with a decreasing, highly curved magnetic field than those

  11. Effects of resolved boundary layer turbulence on near-ground rotation in simulated quasi-linear convective systems (QLCSs)

    Science.gov (United States)

    Nowotarski, C. J.

    2017-12-01

    Though most strong to violent tornadoes are associated with supercell thunderstorms, quasi-linear convective systems (QLCSs) pose a risk of tornadoes, often at times and locations where supercell tornadoes are less common. Because QLCS low-level mesocyclones and tornado signatures tend to be less coherent, forecasting such tornadoes remains particularly difficult. The majority of simulations of such storms rely on horizontally homogeneous base states lacking resolved boundary layer turbulence and surface fluxes. Previous work has suggested that heterogeneities associated with boundary layer turbulence in the form of horizontal convective rolls can influence the evolution and characteristics of low-level mesocyclones in supercell thunderstorms. This study extends methods for generating boundary layer convection to idealized simulations of QLCSs. QLCS simulations with resolved boundary layer turbulence will be compared against a control simulation with a laminar boundary layer. Effects of turbulence, the resultant heterogeneity in the near-storm environment, and surface friction on bulk storm characteristics and the intensity, morphology, and evolution of low-level rotation will be presented. Although maximum surface vertical vorticity values are similar, when boundary layer turbulence is included, a greater number of miso- and meso-scale vortices develop along the QLCS gust front. The source of this vorticity is analyzed using Eulerian decomposition of vorticity tendency terms and trajectory analysis to delineate the relative importance of surface friction and baroclinicity in generating QLCS vortices. The role of anvil shading in suppressing boundary layer turbulence in the near-storm environment and subsequent effects on QLCS vortices will also be presented. Finally, implications of the results regarding inclusion of more realistic boundary layers in future idealized simulations of deep convection will be discussed.

  12. NONLINEAR DYNAMICAL SYSTEMS - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Philip Holmes

    2005-12-31

    This document is the final report on the work completed on DE-FG02-95ER25238 since the start of the second renewal period: Jan 1, 2001. It supplements the annual reports submitted in 2001 and 2002. In the renewal proposal I envisaged work in three main areas: Analytical and topological tools for studying flows and maps Low dimensional models of fluid flow Models of animal locomotion and I describe the progess made on each project.

  13. Evaluation of the Plant-Craig stochastic convection scheme in an ensemble forecasting system

    Science.gov (United States)

    Keane, R. J.; Plant, R. S.; Tennant, W. J.

    2015-12-01

    The Plant-Craig stochastic convection parameterization (version 2.0) is implemented in the Met Office Regional Ensemble Prediction System (MOGREPS-R) and is assessed in comparison with the standard convection scheme with a simple stochastic element only, from random parameter variation. A set of 34 ensemble forecasts, each with 24 members, is considered, over the month of July 2009. Deterministic and probabilistic measures of the precipitation forecasts are assessed. The Plant-Craig parameterization is found to improve probabilistic forecast measures, particularly the results for lower precipitation thresholds. The impact on deterministic forecasts at the grid scale is neutral, although the Plant-Craig scheme does deliver improvements when forecasts are made over larger areas. The improvements found are greater in conditions of relatively weak synoptic forcing, for which convective precipitation is likely to be less predictable.

  14. Tropical Atlantic Hurricanes, Easterly Waves, and West African Mesoscale Convective Systems

    Directory of Open Access Journals (Sweden)

    Yves K. Kouadio

    2010-01-01

    Full Text Available The relationship between tropical Atlantic hurricanes (Hs, atmospheric easterly waves (AEWs, and West African mesoscale convective systems (MCSs is investigated. It points out atmospheric conditions over West Africa before hurricane formation. The analysis was performed for two periods, June–November in 2004 and 2005, during which 12 hurricanes (seven in 2004, five in 2005 were selected. Using the AEW signature in the 700 hPa vorticity, a backward trajectory was performed to the African coast, starting from the date and position of each hurricane, when and where it was catalogued as a tropical depression. At this step, using the Meteosat-7 satellite dataset, we selected all the MCSs around this time and region, and tracked them from their initiation until their dissipation. This procedure allowed us to relate each of the selected Hs with AEWs and a succession of MCSs that occurred a few times over West Africa before initiation of the hurricane. Finally, a dipole in sea surface temperature (SST was observed with a positive SST anomaly within the region of H generation and a negative SST anomaly within the Gulf of Guinea. This SST anomaly dipole could contribute to enhance the continental convergence associated with the monsoon that impacts on the West African MCSs formation.

  15. Experimental lithium system. Final report

    International Nuclear Information System (INIS)

    Kolowith, R.; Berg, J.D.; Miller, W.C.

    1985-04-01

    A full-scale mockup of the Fusion Materials Irradiation Test (FMIT) Facility lithium system was built at the Hanford Engineering Development Laboratory (HEDL). This isothermal mockup, called the Experimental Lithium System (ELS), was prototypic of FMIT, excluding the accelerator and dump heat exchanger. This 3.8 m 3 lithium test loop achieved over 16,000 hours of safe and reliable operation. An extensive test program demonstrated satisfactory performance of the system components, including the HEDL-supplied electromagnetic lithium pump, the lithium jet target, the purification and characterization hardware, as well as the auxiliary argon and vacuum systems. Experience with the test loop provided important information on system operation, performance, and reliability. This report presents a complete overview of the entire Experimental Lithium System test program and also includes a summary of such areas as instrumentation, coolant chemistry, vapor/aerosol transport, and corrosion

  16. Intraseasonal variability of organized convective systems in the Central Andes: Relationship to Regional Dynamical Features

    Science.gov (United States)

    Mohr, K. I.; Slayback, D. A.; Nicholls, S.; Yager, K.

    2013-12-01

    The Andes extend from the west coast of Colombia (10N) to the southern tip of Chile (53S). In southern Peru and Bolivia, the Central Andes is split into separate eastern and western cordilleras, with a high plateau (≥ 3000 m), the Altiplano, between them. Because 90% of the Earth's tropical mountain glaciers are located in the Central Andes, our study focuses on this region, defining its zonal extent as 7S-21S and the meridional extent as the terrain 1000 m and greater. Although intense convection occurs during the wet season in the Altiplano, it is not included in the lists of regions with frequent or the most intense convection. The scarcity of in-situ observations with sufficient density and temporal resolution to resolve individual storms or even mesoscale-organized cloud systems and documented biases in microwave-based rainfall products in poorly gauged mountainous regions have impeded the development of an extensive literature on convection and convective systems in this region. With the tropical glaciers receding at unprecedented rates, leaving seasonal precipitation as an increasingly important input to the water balance in alpine valley ecosystems and streams, understanding the nature and characteristics of the seasonal precipitation becomes increasingly important for the rural economies in this region. Previous work in analyzing precipitation in the Central Andes has emphasized interannual variability with respect to ENSO, this is the first study to focus on shorter scale variability with respect to organized convection. The present study took advantage of the University of Utah's Precipitation Features database compiled from 14 years of TRMM observations (1998-2012), supplemented by field observations of rainfall and streamflow, historical gauge data, and long-term WRF-simulations, to analyze the intraseasonal variability of precipitating systems and their relationship regional dynamical features such as the Bolivian High. Through time series and

  17. Visualization of Natural Convection Heat Transfer on a Single Sphere using the Electroplating System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Young; Chung, Bum Jin [Kyunghee University, Yongin (Korea, Republic of)

    2016-05-15

    The natural convective flows on outer sphere rise along surface. At top of sphere, the flows are lifted-up plume shape. For laminar flows, the local heat transfer shows maximum at the bottom of sphere and a monotonic decreases as flows approached to the top. The laminar natural convection heat transfer on a single sphere has been studied experimentally and numerically by several researchers. However, relatively less study has been performed for turbulent flows as it requires large facilities to achieve high Rayleigh numbers. The flows, which occur transition, is hard to experiment because of unstable. This study tried measurement of heat transfer and visualization external natural convection on a single sphere. The basic idea is that the plating patterns of copper on the sphere in mass transfer system will reveal the amount of heat transfer according to angular distance from the bottom. This study simulated natural convection on a single sphere and performed a mass transfer experiment using heat and mass transfer analogy concept. For visualization experiment, streak form plating pattern was observed. In this case, it seems that turbulence sets on the top of sphere and increases local heat transfer.

  18. Evaluation of a Mesoscale Convective System in Variable-Resolution CESM

    Science.gov (United States)

    Payne, A. E.; Jablonowski, C.

    2017-12-01

    Warm season precipitation over the Southern Great Plains (SGP) follows a well observed diurnal pattern of variability, peaking at night-time, due to the eastward propagation of mesoscale convection systems that develop over the eastern slopes of the Rockies in the late afternoon. While most climate models are unable to adequately capture the organization of convection and characteristic pattern of precipitation over this region, models with high enough resolution to explicitly resolve convection show improvement. However, high resolution simulations are computationally expensive and, in the case of regional climate models, are subject to boundary conditions. Newly developed variable resolution global climate models strike a balance between the benefits of high-resolution regional climate models and the large-scale dynamics of global climate models and low computational cost. Recently developed parameterizations that are insensitive to the model grid scale provide a way to improve model performance. Here, we present an evaluation of the newly available Cloud Layers Unified by Binormals (CLUBB) parameterization scheme in a suite of variable-resolution CESM simulations with resolutions ranging from 110 km to 7 km within a regionally refined region centered over the SGP Atmospheric Radiation Measurement (ARM) site. Simulations utilize the hindcast approach developed by the Department of Energy's Cloud-Associated Parameterizations Testbed (CAPT) for the assessment of climate models. We limit our evaluation to a single mesoscale convective system that passed over the region on May 24, 2008. The effects of grid-resolution on the timing and intensity of precipitation, as well as, on the transition from shallow to deep convection are assessed against ground-based observations from the SGP ARM site, satellite observations and ERA-Interim reanalysis.

  19. A study of the 21 March 2012 tornadic quasi linear convective system in Catalonia

    Science.gov (United States)

    Bech, Joan; Arús, Joan; Castán, Salvador; Pineda, Nicolau; Rigo, Tomeu; Montanyà, Joan; van der Velde, Oscar

    2015-05-01

    This study presents a description of a quasi linear convective system that took place in Catalonia (NE Spain) on 21 March 2012 producing heavy rainfall, moderate lightning activity and a weak tornado in the village of Ivars d'Urgell around 19 UTC after local sunset. A post-event survey indicated EF0 and EF1 damage in houses of the village - roofs and ceilings, broken windows, fences and walls and trees knocked down - along a track approximately 4 km long and about 20 m wide. Doppler radar observations show that the parent thunderstorm that spawned the tornado was one of a series that developed along a convective line that moved from S to N, initiating convective activity in terms of precipitation and lightning in the Mediterranean Sea and moving inland in S Catalonia (Tarragona and Salou coastal areas, producing local flash floods). Convective activity remained several hours with series of thunderstorms developing along the same paths. The synoptic situation was dominated by a high pressure ridge extending from northern Africa to central Europe, with a closed maximum sea level pressure area around 1036 hPa over northern France, southern Germany and Austria. On the other hand a relative low pressure area seen on 850 hPa and upper levels was present over the Iberian Peninsula, favouring a southern maritime flow from the Mediterranean between the forward part of the low pressure area and the high pressure system which blocked the advance of the low to the east. In the study we examine both the synoptic environment and storm scale observations with Doppler radar and total lightning data (cloud to ground and intracloud flashes) that lead to this cool-season severe convective event which is remarkable given the fact that, unlike in this case, most reported tornadoes in the region occur during the warm season (with peaks in August and September) and during daylight hours (6 to 18 UTC).

  20. A continuous and prognostic convection scheme based on buoyancy, PCMT

    Science.gov (United States)

    Guérémy, Jean-François; Piriou, Jean-Marcel

    2016-04-01

    A new and consistent convection scheme (PCMT: Prognostic Condensates Microphysics and Transport), providing a continuous and prognostic treatment of this atmospheric process, is described. The main concept ensuring the consistency of the whole system is the buoyancy, key element of any vertical motion. The buoyancy constitutes the forcing term of the convective vertical velocity, which is then used to define the triggering condition, the mass flux, and the rates of entrainment-detrainment. The buoyancy is also used in its vertically integrated form (CAPE) to determine the closure condition. The continuous treatment of convection, from dry thermals to deep precipitating convection, is achieved with the help of a continuous formulation of the entrainment-detrainment rates (depending on the convective vertical velocity) and of the CAPE relaxation time (depending on the convective over-turning time). The convective tendencies are directly expressed in terms of condensation and transport. Finally, the convective vertical velocity and condensates are fully prognostic, the latter being treated using the same microphysics scheme as for the resolved condensates but considering the convective environment. A Single Column Model (SCM) validation of this scheme is shown, allowing detailed comparisons with observed and explicitly simulated data. Four cases covering the convective spectrum are considered: over ocean, sensitivity to environmental moisture (S. Derbyshire) non precipitating shallow convection to deep precipitating convection, trade wind shallow convection (BOMEX) and strato-cumulus (FIRE), together with an entire continental diurnal cycle of convection (ARM). The emphasis is put on the characteristics of the scheme which enable a continuous treatment of convection. Then, a 3D LAM validation is presented considering an AMMA case with both observations and a CRM simulation using the same initial and lateral conditions as for the parameterized one. Finally, global

  1. Lunar power systems. Final report

    International Nuclear Information System (INIS)

    1986-12-01

    The findings of a study on the feasibility of several methods of providing electrical power for a permanently manned lunar base are provided. Two fundamentally different methods for lunar electrical power generation are considered. One is the use of a small nuclear reactor and the other is the conversion of solar energy to electricity. The baseline goal was to initially provide 300 kW of power with growth capability to one megawatt and eventually to 10 megawatts. A detailed, day by day scenario for the establishment, build-up, and operational activity of the lunar base is presented. Also presented is a conceptual approach to a supporting transportation system which identifies the number, type, and deployment of transportation vehicles required to support the base. An approach to the use of solar cells in the lunar environment was developed. There are a number of heat engines which are applicable to solar/electric conversions, and these are examined. Several approaches to energy storage which were used by the electric power utilities were examined and those which could be used at a lunar base were identified

  2. Basic Concepts for Convection Parameterization in Weather Forecast and Climate Models: COST Action ES0905 Final Report

    Directory of Open Access Journals (Sweden)

    Jun–Ichi Yano

    2014-12-01

    Full Text Available The research network “Basic Concepts for Convection Parameterization in Weather Forecast and Climate Models” was organized with European funding (COST Action ES0905 for the period of 2010–2014. Its extensive brainstorming suggests how the subgrid-scale parameterization problem in atmospheric modeling, especially for convection, can be examined and developed from the point of view of a robust theoretical basis. Our main cautions are current emphasis on massive observational data analyses and process studies. The closure and the entrainment–detrainment problems are identified as the two highest priorities for convection parameterization under the mass–flux formulation. The need for a drastic change of the current European research culture as concerns policies and funding in order not to further deplete the visions of the European researchers focusing on those basic issues is emphasized.

  3. An Automated System to Quantify Convectively induced Aircraft encounters with Turbulence over Europe and North Atlantic

    Science.gov (United States)

    Meneguz, Elena; Turp, Debi; Wells, Helen

    2015-04-01

    It is well known that encounters with moderate or severe turbulence can lead to passenger injuries and incur high costs for airlines from compensation and litigation. As one of two World Area Forecast Centres (WAFCs), the Met Office has responsibility for forecasting en-route weather hazards worldwide for aviation above a height of 10,000 ft. Observations from commercial aircraft provide a basis for gaining a better understanding of turbulence and for improving turbulence forecasts through verification. However there is currently a lack of information regarding the possible cause of the observed turbulence, or whether the turbulence occurred within cloud. Such information would be invaluable for the development of forecasting techniques for particular types of turbulence and for forecast verification. Of all the possible sources of turbulence, convective activity is believed to be a major cause of turbulence. Its relative importance over the Europe and North Atlantic area has not been yet quantified in a systematic way: in this study, a new approach is developed to automate identification of turbulent encounters in the proximity of convective clouds. Observations of convection are provided from two independent sources: a surface based lightning network and satellite imagery. Lightning observations are taken from the Met Office Arrival Time Detections network (ATDnet). ATDnet has been designed to identify cloud-to-ground flashes over Europe but also detects (a smaller fraction of) strikes over the North Atlantic. Meteosat Second Generation (MSG) satellite products are used to identify convective clouds by applying a brightness temperature filtering technique. The morphological features of cold cloud tops are also investigated. The system is run for all in situ turbulence reports received from airlines for a total of 12 months during summer 2013 and 2014 for the domain of interest. Results of this preliminary short term climatological study show significant intra

  4. Radar Observations of Convective Systems from a High-Altitude Aircraft

    Science.gov (United States)

    Heymsfield, G.; Geerts, B.; Tian, L.

    1999-01-01

    Reflectivity data collected by the precipitation radar on board the tropical Rainfall Measuring Mission (TRMM) satellite, orbiting at 350 km altitude, are compared to reflectivity data collected nearly simultaneously by a doppler radar aboard the NASA ER-2 flying at 19-20 km altitude, i.e. above even the deepest convection. The TRMM precipitation radar is a scanning device with a ground swath width of 215 km, and has a resolution of about a4.4 km in the horizontal and 250 m in the vertical (125 m in the core swath 48 km wide). The TRMM radar has a wavelength of 217 cm (13.8 GHz) and the Nadir mirror echo below the surface is used to correct reflectivity for loss by attenuation. The ER-2 Doppler radar (EDOP) has two antennas, one pointing to the nadir, 34 degrees forward. The forward pointing beam receives both the normal and the cross-polarized echos, so the linear polarization ratio field can be monitored. EDOP has a wavelength of 3.12 cm (9.6 GHz), a vertical resolution of 37.5 m and a horizontal along-track resolution of about 100 m. The 2-D along track airflow field can be synthesized from the radial velocities of both beams, if a reflectivity-based hydrometer fall speed relation can be assumed. It is primarily the superb vertical resolution that distinguishes EDOP from other ground-based or airborne radars. Two experiments were conducted during 1998 into validate TRMM reflectivity data over convection and convectively-generated stratiform precipitation regions. The Teflun-A (TEXAS-Florida Underflight) experiment, was conducted in April and May and focused on mesoscale convective systems mainly in southeast Texas. TEFLUN-B was conducted in August-September in central Florida, in coordination with CAMEX-3 (Convection and Moisture Experiment). The latter was focused on hurricanes, especially during landfall, whereas TEFLUN-B concentrated on central; Florida convection, which is largely driven and organized by surface heating and ensuing sea breeze circulations

  5. Effect of surface radiation on natural convection in an asymmetrically heated channel-chimney system

    Science.gov (United States)

    Nasri, Zied; Derouich, Youssef; Laatar, Ali Hatem; Balti, Jalloul

    2018-05-01

    In this paper, a more realistic numerical approach that takes into account the effect of surface radiation on the laminar air flow induced by natural convection in a channel-chimney system asymmetrically heated at uniform heat flux is used. The aim is to enrich the results given in Nasri et al. (Int J Therm Sci 90:122-134, 2015) by varying all the geometric parameters of the system and by taking into account the effect of surface radiation on the flows. The numerical results are first validated against experimental and numerical data available in the literature. The computations have allowed the determination of optimal configurations that maximize the mass flow rate and the convective heat transfer and minimize the heated wall temperatures. The analysis of the temperature fields with the streamlines and the pressure fields has helped to explain the effects of surface radiation and of the different thermo-geometrical parameters on the system performances to improve the mass flow rate and the heat transfer with respect to the simple channel. It is shown that the thermal performance of the channel-chimney system in terms of lower heated wall temperatures is little affected by the surface radiation. At the end, simple correlation equations have been proposed for quickly and easily predict the optimal configurations as well as the corresponding enhancement rates of the induced mass flow rate and the convective heat transfer.

  6. Inversion Approach For Thermal Data From A Convecting Hydrothermal System

    Energy Technology Data Exchange (ETDEWEB)

    Kasameyer, P.; Younker, L.; Hanson, J.

    1985-01-01

    Hydrothermal systems are often studied by collecting thermal gradient data and temperature depth curves. These data contain important information about the flow field, the evolution of the hydrothermal system, and the location and nature of the ultimate heat sources. Thermal data are conventionally interpreted by the ''forward'' method; the thermal field is calculated based on selected initial conditions and boundary conditions such as temperature and permeability distributions. If the calculated thermal field matches the data, the chosen conditions are inferred to be possibly correct. Because many sets of initial conditions may produce similar thermal fields, users of the ''forward'' method may inadvertently miss the correct set of initial conditions. Analytical methods for ''inverting'' data also allow the determination of all the possible solutions consistent with the definition of the problem. In this paper we suggest an approach for inverting thermal data from a hydrothermal system, and compare it to the more conventional approach. We illustrate the difference in the methods by comparing their application to the Salton Sea Geothermal Field by Lau (1980a) and Kasameyer, et al. (1984). In this particular example, the inverse method was used to draw conclusions about the age and total rate of fluid flow into the hydrothermal system.

  7. Final focus systems for linear colliders

    International Nuclear Information System (INIS)

    Erickson, R.A.

    1987-11-01

    The final focus system of a linear collider must perform two primary functions, it must focus the two opposing beams so that their transverse dimensions at the interaction point are small enough to yield acceptable luminosity, and it must steer the beams together to maintain collisions. In addition, the final focus system must transport the outgoing beams to a location where they can be recycled or safely dumped. Elementary optical considerations for linear collider final focus systems are discussed, followed by chromatic aberrations. The design of the final focus system of the SLAC Linear Collider (SLC) is described. Tuning and diagnostics and steering to collision are discussed. Most of the examples illustrating the concepts covered are drawn from the SLC, but the principles and conclusions are said to be generally applicable to other linear collider designs as well. 26 refs., 17 figs

  8. Final Focus Systems in Linear Colliders

    International Nuclear Information System (INIS)

    Raubenheimer, Tor

    1998-01-01

    In colliding beam facilities, the ''final focus system'' must demagnify the beams to attain the very small spot sizes required at the interaction points. The first final focus system with local chromatic correction was developed for the Stanford Linear Collider where very large demagnifications were desired. This same conceptual design has been adopted by all the future linear collider designs as well as the SuperConducting Supercollider, the Stanford and KEK B-Factories, and the proposed Muon Collider. In this paper, the over-all layout, physics constraints, and optimization techniques relevant to the design of final focus systems for high-energy electron-positron linear colliders are reviewed. Finally, advanced concepts to avoid some of the limitations of these systems are discussed

  9. Breakdown of hot-spot model in determining convective amplification in large homogeneous systems

    International Nuclear Information System (INIS)

    Mounaix, Philippe; Divol, Laurent

    2004-01-01

    Convective amplification in large homogeneous systems is studied, both analytically and numerically, in the case of a linear diffraction-free stochastic amplifier. Overall amplification does not result from successive amplifications in small scale high intensity hot spots, but from a single amplification in a delocalized mode of the driver field spreading over the whole interaction length. For this model, the hot-spot approach is found to systematically underestimate the gain factor by more than 50%

  10. Burnout in boiling heat transfer. Part II: subcooled and low quality forced-convection systems

    International Nuclear Information System (INIS)

    Bergles, A.E.

    1977-01-01

    Recent experimental and analytical developments regrading burnout in subcooled and low quality forced-convection systems are reviewed. Much data have been accumulated which clarify the parametric trends and lead to new design correlations for water and a variety of other coolants in both simple and complex geometries. A number of critical experiments and models have been developed to attempt to clarify the burnout mechanism(s) in simpler geometries and power transients

  11. On a Five-Dimensional Chaotic System Arising from Double-Diffusive Convection in a Fluid Layer

    Directory of Open Access Journals (Sweden)

    R. Idris

    2013-01-01

    Full Text Available A chaotic system arising from double-diffusive convection in a fluid layer is investigated in this paper based on the theory of dynamical systems. A five-dimensional model of chaotic system is obtained using the Galerkin truncated approximation. The results showed that the transition from steady convection to chaos via a Hopf bifurcation produced a limit cycle which may be associated with a homoclinic explosion at a slightly subcritical value of the Rayleigh number.

  12. Inversion approach for thermal data from a convecting hydrothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Kasameyer, P.; Younker, L.; Hanson, J.

    1983-08-01

    Efforts to invert thermal data from 13 deep geothermal wells, and from additional shallow heat-flow holes, in order to determine the age and total flow rate of the Salton Sea hydrothermal system are described. The data were inverted for a very restrictive model: single-phase, horizontal flow along prescribed flowlines in a single aquifer bounded by an impermeable cap and base. With simplifying assumptions, the results are shown to depend on only two parameters, the system age, and the aquifer/cap thickness ratio. The surface gradient and temperature distribution within the cap are calculated analytically for all possible parameter values. Those parameters producing temperatures that agree with observations are identified, and the range of acceptable parameters is reduced by conclusions drawn from other geophysical data. The cap thickness is inferred to be 500m from thermal and lithologic data from the wells. The aquifer thickness is limited to less than 2500m by seismic, resistivity and magnetic data. It is concluded that if this model is valid, the system age is constrained between 3000 and 20,000 years.

  13. Observations of Coastally Transitioning West African Mesoscale Convective Systems during NAMMA

    Directory of Open Access Journals (Sweden)

    Bradley W. Klotz

    2012-01-01

    Full Text Available Observations from the NASA 10 cm polarimetric Doppler weather radar (NPOL were used to examine structure, development, and oceanic transition of West African Mesoscale Convective Systems (MCSs during the NASA African Monsoon Multidisciplinary Analysis (NAMMA to determine possible indicators leading to downstream tropical cyclogenesis. Characteristics examined from the NPOL data include echo-top heights, maximum radar reflectivity, height of maximum radar reflectivity, and convective and stratiform coverage areas. Atmospheric radiosondes launched during NAMMA were used to investigate environmental stability characteristics that the MCSs encountered while over land and ocean, respectively. Strengths of African Easterly Waves (AEWs were examined along with the MCSs in order to improve the analysis of MCS characteristics. Mean structural and environmental characteristics were calculated for systems that produced TCs and for those that did not in order to determine differences between the two types. Echo-top heights were similar between the two types, but maximum reflectivity and height and coverage of intense convection (>50 dBZ are all larger than for the TC producing cases. Striking differences in environmental conditions related to future TC formation include stronger African Easterly Jet, increased moisture especially at middle and upper levels, and increased stability as the MCSs coastally transition.

  14. A synoptic climatology of derecho producing mesoscale convective systems in the North-Central Plains

    Science.gov (United States)

    Bentley, Mace L.; Mote, Thomas L.; Byrd, Stephen F.

    2000-09-01

    Synoptic-scale environments favourable for producing derechos, or widespread convectively induced windstorms, in the North-Central Plains are examined with the goal of providing pattern-recognition/diagnosis techniques. Fifteen derechos were identified across the North-Central Plains region during 1986-1995. The synoptic environment at the initiation, mid-point and decay of each derecho was then evaluated using surface, upper-air and National Center for Atmospheric Research (NCAR)/National Center for Environmental Prediction (NCEP) reanalysis datasets.Results suggest that the synoptic environment is critical in maintaining derecho producing mesoscale convective systems (DMCSs). The synoptic environment in place downstream of the MCS initiation region determines the movement and potential strength of the system. Circulation around surface low pressure increased the instability gradient and maximized leading edge convergence in the initiation region of nearly all events regardless of DMCS location or movement. Other commonalities in the environments of these events include the presence of a weak thermal boundary, high convective instability and a layer of dry low-to-mid-tropospheric air. Of the two corridors sampled, northeastward moving derechos tend to initiate east of synoptic-scale troughs, while southeastward moving derechos form on the northeast periphery of a synoptic-scale ridge. Other differences between these two DMCS events are also discussed.

  15. On the episodic nature of derecho-producing convective systems in the United States

    Science.gov (United States)

    Ashley, Walker S.; Mote, Thomas L.; Bentley, Mace L.

    2005-11-01

    Convectively generated windstorms occur over broad temporal and spatial scales; however, one of the larger-scale and most intense of these windstorms has been given the name derecho. This study illustrates the tendency for derecho-producing mesoscale convective systems to group together across the United States - forming a derecho series. The derecho series is recognized as any succession of derechos that develop within a similar synoptic environment with no more than 72 h separating individual events. A derecho dataset for the period 1994-2003 was assembled to investigate the groupings of these extremely damaging convective wind events. Results indicate that over 62% of the derechos in the dataset were members of a derecho series. On average, nearly six series affected the United States annually. Most derecho series consisted of two or three events; though, 14 series during the period of record contained four or more events. Two separate series involved nine derechos within a period of nine days. Analyses reveal that derecho series largely frequent regions of the Midwest, Ohio Valley, and the south-central Great Plains during May, June, and July. Results suggest that once a derecho occurred during May, June, or July, there was a 58% chance that this event was the first of a series of two or more, and about a 46% chance that this was the first of a derecho series consisting of three or more events. The derecho series climatology reveals that forecasters in regions frequented by derechos should be prepared for the probable regeneration of a derecho-producing convective system after an initial event occurs. Copyright

  16. Final focus systems for linear colliders

    International Nuclear Information System (INIS)

    Helm, R.; Irwin, J.

    1992-08-01

    Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We will outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We will discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread, bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, will be described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC will be given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC)

  17. Final focus systems for linear colliders

    International Nuclear Information System (INIS)

    Helm, R.; Irwing, J.

    1992-01-01

    Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread , bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, are described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC are given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC). (Author) 16 refs., 4 tabs., 6 figs

  18. Thermal Sizing of Heat Exchanger Tubes for Air Natural Convective Cooling System of Emergency Cooling Tank

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Jun; Lee, Hee Joon [Kookmin Univ., Seoul (Korea, Republic of); Moon, Joo Hyung; Bae, Youngmin; Kim, Youngin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    For the long operation of secondary passive cooling system, however, water level goes down by evaporation in succession at emergency cooling tank. At the end there would be no place to dissipate heat from condensation heat exchanger. Therefore, steam cooling heat exchanger is put on the top of emergency cooling tank to maintain appropriate water level by collecting evaporating steam. Steam cooling heat exchanger is installed inside an air chimney and evaporated steam is cooled down by air natural convection. In this study, thermal sizing of steam cooling heat exchanger under air natural convection was conducted by TSCON program for the design of experimental setup as shown in Fig. 2. Thermal sizing of steam cooling heat exchanger tube under air natural convection was conducted by TSCON program for the design of experimental setup. 25 - 1' tubes which has a length 1687 mm was determined as steam cooling heat exchanger at 2 kW heat load and 100 liter water pool in emergency cooling tank (experimental limit condition). The corresponding width of two tubes is 50 mm and has 5 by 5 tube array for heat exchanger.

  19. Thermal Sizing of Heat Exchanger Tubes for Air Natural Convective Cooling System of Emergency Cooling Tank

    International Nuclear Information System (INIS)

    Kim, Myoung Jun; Lee, Hee Joon; Moon, Joo Hyung; Bae, Youngmin; Kim, Youngin

    2014-01-01

    For the long operation of secondary passive cooling system, however, water level goes down by evaporation in succession at emergency cooling tank. At the end there would be no place to dissipate heat from condensation heat exchanger. Therefore, steam cooling heat exchanger is put on the top of emergency cooling tank to maintain appropriate water level by collecting evaporating steam. Steam cooling heat exchanger is installed inside an air chimney and evaporated steam is cooled down by air natural convection. In this study, thermal sizing of steam cooling heat exchanger under air natural convection was conducted by TSCON program for the design of experimental setup as shown in Fig. 2. Thermal sizing of steam cooling heat exchanger tube under air natural convection was conducted by TSCON program for the design of experimental setup. 25 - 1' tubes which has a length 1687 mm was determined as steam cooling heat exchanger at 2 kW heat load and 100 liter water pool in emergency cooling tank (experimental limit condition). The corresponding width of two tubes is 50 mm and has 5 by 5 tube array for heat exchanger

  20. Study and Application of Forced Convection in Road Bus Heating System

    Directory of Open Access Journals (Sweden)

    Scheila Sandi Biazus

    2015-03-01

    Full Text Available This work deals with a replacing the heating system of intercity buses, made by long heat exchangers distributed on the sides of the passenger saloon by small and compact ones that use forced convection to heat dissipation. At the beginning the calculation was made of the heat capacity of a heat exchanger with the parameters defined by the supplier, and then conducted an analysis of change in these parameters in order to improve its efficiency. The method for examining the heat exchanger is based on the correlations available in the convection flow inside and outside to determine the respective convective coefficients, and therefore the overall coefficient of heat transfer. Following, the heat exchanger in its original form, was tested on bench. Thus, from the thermal load of the bus model studied, the amount of exchangers required has been defined to satisfy the thermal comfort of passengers. Field tests of the heating systems with new heat exchangers were performed to obtain actual data of the proposed system. The original factory system showed to be efficient in meeting the needs thermal load and economically viable, such that the critical thermal load can be met with ten heaters installed along the body. Furthermore, this system offers the possibility of varying the parameters to best fit to the project, where the flow variation of the fans or the spacing between the fins of the heat exchanger decreases the amount of heaters required. At the same time, the system showed the need for further study to assess its distribution along the passenger saloon in order to meet a best uniformity temperature distribution.

  1. The Impact of Microphysics on Intensity and Structure of Hurricanes and Mesoscale Convective Systems

    Science.gov (United States)

    Tao, Wei-Kuo; Shi, Jainn J.; Jou, Ben Jong-Dao; Lee, Wen-Chau; Lin, Pay-Liam; Chang, Mei-Yu

    2007-01-01

    During the past decade, both research and operational numerical weather prediction models, e.g. Weather Research and Forecast (WRF) model, have started using more complex microphysical schemes originally developed for high-resolution cloud resolving models (CRMs) with a 1-2 km or less horizontal resolutions. WRF is a next-generation mesoscale forecast model and assimilation system that has incorporated modern software framework, advanced dynamics, numeric and data assimilation techniques, a multiple moveable nesting capability, and improved physical packages. WRF model can be used for a wide range of applications, from idealized research to operational forecasting, with an emphasis on horizontal grid sizes in the range of 1-10 km. The current WRF includes several different microphysics options such as Purdue Lin et al. (1983), WSM 6-class and Thompson microphysics schemes. We have recently implemented three sophisticated cloud microphysics schemes into WRF. The cloud microphysics schemes have been extensively tested and applied for different mesoscale systems in different geographical locations. The performances of these schemes have been compared to those from other WRF microphysics options. We are performing sensitivity tests in using WRF to examine the impact of six different cloud microphysical schemes on precipitation processes associated hurricanes and mesoscale convective systems developed at different geographic locations [Oklahoma (IHOP), Louisiana (Hurricane Katrina), Canada (C3VP - snow events), Washington (fire storm), India (Monsoon), Taiwan (TiMREX - terrain)]. We will determine the microphysical schemes for good simulated convective systems in these geographic locations. We are also performing the inline tracer calculation to comprehend the physical processes (i.e., boundary layer and each quadrant in the boundary layer) related to the development and structure of hurricanes and mesoscale convective systems.

  2. Determining ice water content from 2D crystal images in convective cloud systems

    Science.gov (United States)

    Leroy, Delphine; Coutris, Pierre; Fontaine, Emmanuel; Schwarzenboeck, Alfons; Strapp, J. Walter

    2016-04-01

    Cloud microphysical in-situ instrumentation measures bulk parameters like total water content (TWC) and/or derives particle size distributions (PSD) (utilizing optical spectrometers and optical array probes (OAP)). The goal of this work is to introduce a comprehensive methodology to compute TWC from OAP measurements, based on the dataset collected during recent HAIC (High Altitude Ice Crystals)/HIWC (High Ice Water Content) field campaigns. Indeed, the HAIC/HIWC field campaigns in Darwin (2014) and Cayenne (2015) provide a unique opportunity to explore the complex relationship between cloud particle mass and size in ice crystal environments. Numerous mesoscale convective systems (MCSs) were sampled with the French Falcon 20 research aircraft at different temperature levels from -10°C up to 50°C. The aircraft instrumentation included an IKP-2 (isokinetic probe) to get reliable measurements of TWC and the optical array probes 2D-S and PIP recording images over the entire ice crystal size range. Based on the known principle relating crystal mass and size with a power law (m=α•Dβ), Fontaine et al. (2014) performed extended 3D crystal simulations and thereby demonstrated that it is possible to estimate the value of the exponent β from OAP data, by analyzing the surface-size relationship for the 2D images as a function of time. Leroy et al. (2015) proposed an extended version of this method that produces estimates of β from the analysis of both the surface-size and perimeter-size relationships. Knowing the value of β, α then is deduced from the simultaneous IKP-2 TWC measurements for the entire HAIC/HIWC dataset. The statistical analysis of α and β values for the HAIC/HIWC dataset firstly shows that α is closely linked to β and that this link changes with temperature. From these trends, a generalized parameterization for α is proposed. Finally, the comparison with the initial IKP-2 measurements demonstrates that the method is able to predict TWC values

  3. Convective Systems Over the Japan Sea: Cloud-Resolving Model Simulations

    Science.gov (United States)

    Tao, Wei-Kuo; Yoshizaki, Masanori; Shie, Chung-Lin; Kato, Teryuki

    2002-01-01

    Wintertime observations of MCSs (Mesoscale Convective Systems) over the Sea of Japan - 2001 (WMO-01) were collected from January 12 to February 1, 2001. One of the major objectives is to better understand and forecast snow systems and accompanying disturbances and the associated key physical processes involved in the formation and development of these disturbances. Multiple observation platforms (e.g., upper-air soundings, Doppler radar, wind profilers, radiometers, etc.) during WMO-01 provided a first attempt at investigating the detailed characteristics of convective storms and air pattern changes associated with winter storms over the Sea of Japan region. WMO-01 also provided estimates of the apparent heat source (Q1) and apparent moisture sink (Q2). The vertical integrals of Q1 and Q2 are equal to the surface precipitation rates. The horizontal and vertical adjective components of Q1 and Q2 can be used as large-scale forcing for the Cloud Resolving Models (CRMs). The Goddard Cumulus Ensemble (GCE) model is a CRM (typically run with a 1-km grid size). The GCE model has sophisticated microphysics and allows explicit interactions between clouds, radiation, and surface processes. It will be used to understand and quantify precipitation processes associated with wintertime convective systems over the Sea of Japan (using data collected during the WMO-01). This is the first cloud-resolving model used to simulate precipitation processes in this particular region. The GCE model-simulated WMO-01 results will also be compared to other GCE model-simulated weather systems that developed during other field campaigns (i.e., South China Sea, west Pacific warm pool region, eastern Atlantic region and central USA).

  4. The stabilisation of final focus system

    Indian Academy of Sciences (India)

    The StaFF (stabilisation of final focus) system will use interferometers to monitor the relative ... quadrupole magnets will be the most demanding application, where mutual and beam- ... interferometers to measure lines of a geodetic network to record relative motion between two beam ... coupled interferometer design.

  5. Organizational Modes of Severe Wind-producing Convective Systems over North China

    Science.gov (United States)

    Yang, Xinlin; Sun, Jianhua

    2018-05-01

    Severe weather reports and composite radar reflectivity data from 2010-14 over North China were used to analyze the distribution of severe convective wind (SCW) events and their organizational modes of radar reflectivity. The six organizational modes for SCW events (and their proportions) were cluster cells (35.4%), squall lines (18.4%), nonlinear-shaped systems (17.8%), broken lines (11.6%), individual cells (1.2%), and bow echoes (0.5%). The peak month for both squall lines and broken lines was June, whereas it was July for the other four modes. The highest numbers of SCW events were over the mountains, which were generally associated with disorganized systems of cluster cells. In contrast, SCW associated with linear systems occurred mainly over the plains, where stations recorded an average of less than one SCW event per year. Regions with a high frequency of SCW associated with nonlinear-shaped systems also experienced many SCW events associated with squall lines. Values of convective available potential energy, precipitable water, 0-3-km shear, and 0-6-km shear, were demonstrably larger over the plains than over the mountains, which had an evident effect on the organizational modes of SCW events. Therefore, topography may be an important factor in the organizational modes for SCW events over North China.

  6. Research on Vehicle Temperature Regulation System Based on Air Convection Principle

    Science.gov (United States)

    Zhuge, Muzi; Li, Xiang; Liang, Caifeng

    2018-03-01

    The long time parking outdoors in the summer will lead to too high temperature in the car, and the harmful gas produced by the vehicle engine will stay in the confined space for a long time during the parking process, which will do great harm to the human body. If the air conditioning system is turned on before driving, the cooling rate is slow and the battery loss is large. To solve the above problems, we designed a temperature adjusting system based on the principle of air convection. We can choose the automatic mode or manual mode to achieve control of a convection window. In the automatic mode, the system will automatically detect the environmental temperature, through the sensor to complete the detection, and the signal is transmitted to the microcontroller to control the window open or close, in manual mode, the remote control of the window can be realized by Bluetooth. Therefore, the system has important practical significance to effectively regulate temperature, prolong battery life, and improve the safety and comfort of traffic vehicles.

  7. Numerical analysis of natural convection in a double-layer immiscible system

    International Nuclear Information System (INIS)

    Gubaidullin, A.A.; Sehgal, B.R.

    2001-01-01

    In the present paper numerical analysis has been applied to study the natural convection heat transfer in a system composed of two immiscible fluids with uniform internal heat generation in the lower layer or in both layers enclosed in a rectangular or in a semi-circular vessel. The objective of the work is to perform a parametric study to assess the effect of physical properties on the heat transfer characteristics as well as to complement results obtained from experiments by means of CFD simulations for a range of lower Rayleigh number and combine the experimental data and the computational results. (author)

  8. Burnout in boiling heat transfer. II. Subcooled and low-quality forced-convection systems

    International Nuclear Information System (INIS)

    Bergles, A.E.

    1977-01-01

    Recent experimental and analytical developments regarding burnout in subcooled and low-quality forced-convection systems are reviewed. Many data have been accumulated which clarify the parametric trends and lead to new design correlations for water and a variety of other coolants in both simple and complex geometries. A number of critical experiments and models have been developed to attempt to clarify the burnout mechanism(s) in simpler geometries. Other topics discussed include burnout with power transients and techniques to augment burnout. 86 references

  9. Dynamics and mass transport of solutal convection in a closed porous media system

    Science.gov (United States)

    Wen, Baole; Akhbari, Daria; Hesse, Marc

    2016-11-01

    Most of the recent studies of CO2 sequestration are performed in open systems where the constant partial pressure of CO2 in the vapor phase results in a time-invariant saturated concentration of CO2 in the brine (Cs). However, in some closed natural CO2 reservoirs, e.g., Bravo Dome in New Mexico, the continuous dissolution of CO2 leads to a pressure drop in the gas that is accompanied by a reduction of Cs and thereby affects the dynamics and mass transport of convection in the brine. In this talk, I discuss the characteristics of convective CO2 dissolution in a closed system. The gas is assumed to be ideal and its solubility given by Henry's law. An analytical solution shows that the diffusive base state is no longer self-similar and that diffusive mass transfer declines rapidly. Scaling analysis reveals that the volume ratio of brine and gas η determines the behavior of the system. DNS show that no constant flux regime exists for η > 0 nevertheless, the quantity F /Cs2 remains constant, where F is the dissolution flux. The onset time is only affected by η when the Rayleigh number Ra is small. In this case, the drop in Cs during the initial diffusive regime significantly reduces the effective Ra and therefore delays the onset.

  10. Fully determined scaling laws for volumetrically heated convective systems, a tool for assessing habitability of exoplanets

    Science.gov (United States)

    Vilella, Kenny; Kaminski, Edouard

    2017-05-01

    The long-term habitability of a planet rises from its ability to generate and maintain an atmosphere through partial melting and volcanism. This question has been mainly addressed in the framework of plate tectonics, which may be too specific to apply to the wide range of internal dynamics expected for exoplanets, and even to the thermal evolution of the early Earth. Here we propose a more general theoretical approach of convection to build a regime diagram giving the conditions for partial melting to occur, in planetary bodies, as a function of key parameters that can be estimated for exoplanets, their size and internal heating rate. To that aim, we introduce a refined view of the Thermal Boundary Layer (TBL) in a convective system heated from within, that focuses on the temperature and thickness of the TBL at the top of the hottest temperature profiles, along which partial melting shall first occur. This ;Hottest Thermal Boundary Layer; (HotTBL) is first characterized using fully theoretical scaling laws based on the dynamics of thermal boundary layers. These laws are the first ones proposed in the literature that do not rely on empirical determinations of dimensionless constants and that apply to both low Rayleigh and high Rayleigh convective regimes. We show that the scaling laws can be successfully applied to planetary bodies by comparing their predictions to full numerical simulations of the Moon. We then use the scaling laws to build a regime diagram for exoplanets. Combined with estimates of internal heating in exoplanets, the regime diagram predicts that in the habitable zone partial melting occurs in planets younger than the Earth.

  11. Experimental analysis on a novel solar collector system achieved by supercritical CO2 natural convection

    International Nuclear Information System (INIS)

    Chen, Lin; Zhang, Xin-Rong

    2014-01-01

    Highlights: • Supercritical CO 2 flow is proposed for natural circulation solar water heater system. • Experimental system established and consists of supercritical fluid high pressure side and water side. • Stable supercritical CO 2 natural convective flow is well induced and water heating process achieved. • Seasonal solar collector system efficiency above 60% achieved and optimization discussed. - Abstract: Solar collector has become a hot topic both in scientific research and engineering applications. Among the various applications, the hot water supply demand accounts for a large part of social energy consumption and has become one promising field. The present study deals with a novel solar thermal conversion and water heater system achieved by supercritical CO 2 natural circulation. Experimental systems are established and tested in Zhejiang Province (around N 30.0°, E 120.6°) of southeast China. The current system is designed to operate in the supercritical region, thus the system can be compactly made and achieve smooth high rate natural convective flow. During the tests, supercritical CO 2 pipe flow with Reynolds number higher than 6700 is found. The CO 2 fluid temperature in the heat exchanger can be as high as 80 °C and a stable supply of hot water above 45 °C is achieved. In the seasonal tests, relative high collector efficiency generally above 60.0% is obtained. Thermal and performance analysis is carried out with the experiment data. Comparisons between the present system and previous solar water heaters are also made in this paper

  12. Impact of different parameterization schemes on simulation of mesoscale convective system over south-east India

    Science.gov (United States)

    Madhulatha, A.; Rajeevan, M.

    2018-02-01

    Main objective of the present paper is to examine the role of various parameterization schemes in simulating the evolution of mesoscale convective system (MCS) occurred over south-east India. Using the Weather Research and Forecasting (WRF) model, numerical experiments are conducted by considering various planetary boundary layer, microphysics, and cumulus parameterization schemes. Performances of different schemes are evaluated by examining boundary layer, reflectivity, and precipitation features of MCS using ground-based and satellite observations. Among various physical parameterization schemes, Mellor-Yamada-Janjic (MYJ) boundary layer scheme is able to produce deep boundary layer height by simulating warm temperatures necessary for storm initiation; Thompson (THM) microphysics scheme is capable to simulate the reflectivity by reasonable distribution of different hydrometeors during various stages of system; Betts-Miller-Janjic (BMJ) cumulus scheme is able to capture the precipitation by proper representation of convective instability associated with MCS. Present analysis suggests that MYJ, a local turbulent kinetic energy boundary layer scheme, which accounts strong vertical mixing; THM, a six-class hybrid moment microphysics scheme, which considers number concentration along with mixing ratio of rain hydrometeors; and BMJ, a closure cumulus scheme, which adjusts thermodynamic profiles based on climatological profiles might have contributed for better performance of respective model simulations. Numerical simulation carried out using the above combination of schemes is able to capture storm initiation, propagation, surface variations, thermodynamic structure, and precipitation features reasonably well. This study clearly demonstrates that the simulation of MCS characteristics is highly sensitive to the choice of parameterization schemes.

  13. Experimental investigation of the influence of the air jet trajectory on convective heat transfer in buildings equipped with air-based and radiant cooling systems

    DEFF Research Database (Denmark)

    Le Dreau, Jerome; Heiselberg, Per; Jensen, Rasmus Lund

    2015-01-01

    -state and dynamic conditions. With the air-based cooling system, a dependency of the convective heat transfer on the air jet trajectory has been observed. New correlations have been developed, introducing a modified Archimedes number to account for the air flow pattern. The accuracy of the new correlations has been...... evaluated to±15%. Besides the study with an air-based cooling system, the convective heat transfer with a radiant cooling system has also been investigated. The convective flow at the activated surface is mainly driven by natural convection. For other surfaces, the complexity of the flow and the large......The complexity and diversity of airflow in buildings make the accurate definition of convective heat transfer coefficients (CHTCs) difficult. In a full-scale test facility, the convective heat transfer of two cooling systems (active chilled beam and radiant wall) has been investigated under steady...

  14. On the role of ice-nucleating aerosol in the formation of ice particles in tropical mesoscale convective systems

    Science.gov (United States)

    Ladino, Luis A.; Korolev, Alexei; Heckman, Ivan; Wolde, Mengistu; Fridlind, Ann M.; Ackerman, Andrew S.

    2018-01-01

    Over decades, the cloud physics community has debated the nature and role of aerosol particles in ice initiation. The present study shows that the measured concentration of ice crystals in tropical mesoscale convective systems exceeds the concentration of ice nucleating particles (INPs) by several orders of magnitude. The concentration of INPs was assessed from the measured aerosol particles concentration in the size range of 0.5 to 1 µm. The observations from this study suggest that primary ice crystals formed on INPs make only a minor contribution to the total concentration of ice crystals in tropical mesoscale convective systems. This is found by comparing the predicted INP number concentrations with in-situ ice particle number concentrations. The obtained measurements suggest that ice multiplication is the likely explanation for the observed high concentrations of ice crystals in this type of convective system. PMID:29551842

  15. A Gigantic Jet Observed Over an Mesoscale Convective System in Midlatitude Region

    Science.gov (United States)

    Yang, Jing; Sato, Mitsuteru; Liu, Ningyu; Lu, Gaopeng; Wang, Yu; Wang, Zhichao

    2018-01-01

    Gigantic jets (GJs) are mostly observed over summer tropical or tropical-like thunderstorms. This study reports observation of a GJ over a mesoscale convective system (MCS) in the midlatitude region in eastern China. The GJ is observed over a relatively weak radar reflectivity region ahead of the leading line, and the maximum radar echo top along the GJ azimuth was lower than the tropopause in the same region, significantly different from past studies that indicate summer GJs are usually associated with convective surges or overshooting tops. Also different from most of previous observations showing GJ-producing summer thunderstorms only produced GJ type of transient luminous events during their life cycles, two sprites were also captured in a time window of 15 min containing the GJ, indicating that the MCS provides favorable conditions not only for the GJ but also for the sprites. The balloon-borne soundings of the MCS show that there were large wind shears in the middle and upper levels of the thundercloud, which may have played important roles for the GJ production.

  16. Convective heat transfer of supercritical CO_2 in a rock fracture for enhanced geothermal systems

    International Nuclear Information System (INIS)

    Zhang, Le; Jiang, Peixue; Wang, Zhenchuan; Xu, Ruina

    2017-01-01

    Highlights: • Contrasting experiments between a rough and a smooth fracture were performed. • A numerical model of rough fracture was reconstructed based on CT scanning data. • Heat transfer in rough fracture was affected by channeling and disturbance effects. - Abstract: Convective heat transfer characteristics of supercritical pressure fluid in a rock fracture are important for building an accurate heat transfer model of enhanced geothermal systems. This paper presents experimental investigations of laminar convection heat transfer of supercritical pressure CO_2 in an artificial smooth parallel-plate fracture and a rough and tortuous fracture that was created using the Brazilian technique. Hot rock with a relatively high initial temperature reserves more heat, which can ensure a larger heat extraction rate for a longer time when cold fluid flows through the fracture. Compared with the smooth parallel-plate fracture, CO_2 flowing through the rough and tortuous fracture with an equivalent hydraulic aperture extracted less heat from the hot rock due to the less efficient heat exchange in a rough fracture caused by channeling effect. This was illustrated by numerical simulation results of the reconstructed fracture based on micro-computed tomography scan data. The overall Nusselt number obtained from the numerical results was larger in a rough fracture with a larger Reynolds number due to disturbance effect on the boundary layer development. The heat transfer performance in a rough fracture is therefore influenced by interactions of the channeling and disturbance effects caused by the tortuous flow path.

  17. The response of a simulated Mesoscale Convective System to increased aerosol pollution

    Science.gov (United States)

    Clavner, Michal

    This work focuses on the impacts of aerosols on the total precipitation amount, rates and spatial distribution of precipitation produced by a Mesoscale Convective System (MCS), as well as the characteristics of a derecho event. Past studies have shown that the impacts on MCS-produced precipitation to changes in aerosol concentration are strongly dependent on environmental conditions, primarily humidity and environmental wind shear. Changes in aerosol concentrations were found to alter MCS-precipitation production directly by modifying precipitation processes and indirectly by affecting the efficiency of the storm's self-propagation. Observational and numerical studies have been conducted that have examined the dynamics responsible for the generation of widespread convectively-induced windstorms, primarily focusing on environmental conditions and the MCS features that generate a derecho event. While the sensitivity of the formation of bow-echoes, the radar signature associated with derecho events, to changes in microphysics has been examined, a study on a derecho-producing MCS characteristics to aerosol concentrations has not. In this study different aerosol concentrations and their effects on precipitation and a derecho produced by an MCS are examined by simulating the 8 May 2009 "Super-Derecho" MCS. The MCS was simulated using the Regional Atmospheric Modeling System (RAMS), a cloud-resolving model (CRM) with sophisticated aerosol and microphysical parameterizations. Three simulations were conducted that varied in their initial aerosol concentration, distribution and hygroscopicity as determined by their emission sources. The first simulation contained aerosols from only natural sources and the second with aerosols sourced from both natural and anthropogenic emissions The third simulation contained the same aerosol distribution as in the second simulation, however multiplied by a factor of 5 in order to represent a highly polluted scenario. In all three of the

  18. SatisFactory Final System Evaluation Report

    OpenAIRE

    Sunlight SA

    2018-01-01

    The present document is a deliverable of the SatisFactory project, funded by the European Commission’s Directorate-General for Research and Innovation (DG RTD), under its Horizon 2020 Research and innovation programme (H2020). The main objective of this deliverable is to report on the SatisFactory Final System Evaluation, with regards to the industrial pilots at COMAU and SUNLIGHT. The evaluation of SatisFactory platform is based on the implementation of the business scenarios where each tool...

  19. Spatio-temporal distributions of meso convective systems in NE China and its vicinity

    Science.gov (United States)

    Yuan, Meiying; Li, Zechun; Zhang, Xiaoling; Li, Xun

    2008-08-01

    Based on the IR cloud imagery from the Chinese FY-2C satellite for June ~ August, 2005 - 2007, statistics is undertaken of meso convective systems (MCS) over NE China and its neighborhood, obtaining the space - time distributions of MCS. MCS include elliptical type( MCC's) , persistent elongated type (PECS's), in shape. Dividing the total MCS into MαMCS, MβMCS and MCC (PECS) . Results show that the number of meso-α MCS (dominantly PECS's) is considerably more than that of meso-β MCS (largely MCCss), which are observed mainly in the NE China plain and Daxing'an Mountains, especially in the entrance to the plain as well as its central ~ northern portion; the MCS occur mainly in June ~ August, particularly in June; the extratropical MCS show two peak phases, one being in 1500-2200 BST the other being 0000-0700 BST as the secondary peaking interval.

  20. Surface properties, more than size, limiting convective distribution of virus-sized particles and viruses in the central nervous system.

    Science.gov (United States)

    Chen, Michael Y; Hoffer, Alan; Morrison, Paul F; Hamilton, John F; Hughes, Jeffrey; Schlageter, Kurt S; Lee, Jeongwu; Kelly, Brandon R; Oldfield, Edward H

    2005-08-01

    Achieving distribution of gene-carrying vectors is a major barrier to the clinical application of gene therapy. Because of the blood-brain barrier, the distribution of genetic vectors to the central nervous system (CNS) is even more challenging than delivery to other tissues. Direct intraparenchymal microinfusion, a minimally invasive technique, uses bulk flow (convection) to distribute suspensions of macromolecules widely through the extracellular space (convection-enhanced delivery [CED]). Although acute injection into solid tissue is often used for delivery of oligonucleotides, viruses, and liposomes, and there is preliminary evidence that certain of these large particles can spread through the interstitial space of the brain by the use of convection, the use of CED for distribution of viruses in the brain has not been systematically examined. That is the goal of this study. Investigators used a rodent model to examine the influence of size, osmolarity of buffering solutions, and surface coating on the volumetric distribution of virus-sized nanoparticles and viruses (adeno-associated viruses and adenoviruses) in the gray matter of the brain. The results demonstrate that channels in the extracellular space of gray matter in the brain are large enough to accommodate virus-sized particles and that the surface characteristics are critical determinants for distribution of viruses in the brain by convection. These results indicate that convective distribution can be used to distribute therapeutic viral vectors in the CNS.

  1. Numerical Simulations of TRMM LBA, TOGA, COARE, GATE, ARM and PRESTORM Convective Systems: Sensitivity tests on Microphysical Processes

    Science.gov (United States)

    Tao, W.-K.; Wang, Y.; Lang, S.; Ferrier, B.; Simpson, J.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The 3D Goddard Cumulus Ensemble (GCE) model was utilized to examine the behavior and response of simulated deep tropical cloud systems that occurred over the west Pacific warm pool region, the Atlantic ocean and the central United States. The periods chosen for simulation were convectively active periods during TOGA-COARE (February 22 1993, December 11-17, 1992; December 19-28, February 9-13, 1993), GATE (September 4, 1974), LBA (January 26 and February 23, 1998), ARM (1997 IOP) and PRESTORM (June 11, 1985). We will examine differences in the microphysics for both warm rain and ice processes (evaporation /sublimation and condensation/ deposition), Q1 (Temperature), Q2 (Water vapor) and Q3 (momentum both U and V) budgets for these three convective events from different large-scale environments. The contribution of stratiform precipitation and its relationship to the vertical shear of the large-scale horizontal wind will also be examined. New improvements to the GCE model (i.e., microphysics: 4ICE two moments and 3ICE one moment; advection schemes) as well as their sensitivity to the model results will be discussed. Preliminary results indicated that various microphysical schemes could have a major impact on stratiform formation as well as the size of convective systems. However, they do not change the major characteristics of the convective systems, such as: arc shape, strong rotational circulation on both ends of system, heavy precipitation along the leading edge of systems.

  2. Final Report: Hydrogen Storage System Cost Analysis

    Energy Technology Data Exchange (ETDEWEB)

    James, Brian David [Strategic Analysis Inc., Arlington, VA (United States); Houchins, Cassidy [Strategic Analysis Inc., Arlington, VA (United States); Huya-Kouadio, Jennie Moton [Strategic Analysis Inc., Arlington, VA (United States); DeSantis, Daniel A. [Strategic Analysis Inc., Arlington, VA (United States)

    2016-09-30

    The Fuel Cell Technologies Office (FCTO) has identified hydrogen storage as a key enabling technology for advancing hydrogen and fuel cell power technologies in transportation, stationary, and portable applications. Consequently, FCTO has established targets to chart the progress of developing and demonstrating viable hydrogen storage technologies for transportation and stationary applications. This cost assessment project supports the overall FCTO goals by identifying the current technology system components, performance levels, and manufacturing/assembly techniques most likely to lead to the lowest system storage cost. Furthermore, the project forecasts the cost of these systems at a variety of annual manufacturing rates to allow comparison to the overall 2017 and “Ultimate” DOE cost targets. The cost breakdown of the system components and manufacturing steps can then be used to guide future research and development (R&D) decisions. The project was led by Strategic Analysis Inc. (SA) and aided by Rajesh Ahluwalia and Thanh Hua from Argonne National Laboratory (ANL) and Lin Simpson at the National Renewable Energy Laboratory (NREL). Since SA coordinated the project activities of all three organizations, this report includes a technical description of all project activity. This report represents a summary of contract activities and findings under SA’s five year contract to the US Department of Energy (Award No. DE-EE0005253) and constitutes the “Final Scientific Report” deliverable. Project publications and presentations are listed in the Appendix.

  3. Validation of system codes RELAP5 and SPECTRA for natural convection boiling in narrow channels

    Energy Technology Data Exchange (ETDEWEB)

    Stempniewicz, M.M., E-mail: stempniewicz@nrg.eu; Slootman, M.L.F.; Wiersema, H.T.

    2016-10-15

    Highlights: • Computer codes RELAP5/Mod3.3 and SPECTRA 3.61 validated for boiling in narrow channels. • Validated codes can be used for LOCA analyses in research reactors. • Code validation based on natural convection boiling in narrow channels experiments. - Abstract: Safety analyses of LOCA scenarios in nuclear power plants are performed with so called thermal–hydraulic system codes, such as RELAP5. Such codes are validated for typical fuel geometries applied in nuclear power plants. The question considered by this article is if the codes can be applied for LOCA analyses in research reactors, in particular exceeding CHF in very narrow channels. In order to answer this question, validation calculations were performed with two thermal–hydraulic system codes: RELAP and SPECTRA. The validation was based on natural convection boiling in narrow channels experiments, performed by Prof. Monde et al. in the years 1990–2000. In total 42 vertical tube and annulus experiments were simulated with both codes. A good agreement of the calculated values with the measured data was observed. The main conclusions are: • The computer codes RELAP5/Mod 3.3 (US NRC version) and SPECTRA 3.61 have been validated for natural convection boiling in narrow channels using experiments of Monde. The dimensions applied in the experiments were performed for a range that covers the values observed in typical research reactors. Therefore it is concluded that both codes are validated and can be used for LOCA analyses in research reactors, including natural convection boiling. The applicability range of the present validation is: hydraulic diameters of 1.1 ⩽ D{sub hyd} ⩽ 9.0 mm, heated lengths of 0.1 ⩽ L ⩽ 1.0 m, pressures of 0.10 ⩽ P ⩽ 0.99 MPa. In most calculations the burnout was predicted to occur at lower power than that observed in the experiments. In several cases the burnout was observed at higher power. The overprediction was not larger than 16% in RELAP and 15% in

  4. Hydration of the lower stratosphere by ice crystal geysers over land convective systems

    Directory of Open Access Journals (Sweden)

    S. Khaykin

    2009-03-01

    Full Text Available The possible impact of deep convective overshooting over land has been explored by six simultaneous soundings of water vapour, particles and ozone in the lower stratosphere next to Mesoscale Convective Systems (MCSs during the monsoon season over West Africa in Niamey, Niger in August 2006. The water vapour measurements were carried out using a fast response FLASH-B Lyman-alpha hygrometer. The high vertical resolution observations of the instrument show the presence of accumulation of enhanced water vapour layers between the tropopause at 370 K and the 420 K level. Most of these moist layers are shown connected with overshooting events occurring upwind as identified from satellite IR images over which the air mass probed by the sondes passed during the three previous days. In the case of a local overshoot identified by echo top turrets above the tropopause by the MIT C-band radar also in Niamey, tight coincidence was found between enhanced water vapour, ice crystal and ozone dip layers indicative of fast uplift of tropospheric air across the tropopause. The water vapour mixing ratio in the enriched layers exceeds frequently by 1–3 ppmv the average 6 ppmv saturation ratio at the tropopause and by up to 7 ppmv in the extreme case of local storm in coincidence with the presence of ice crystals. The presence of such layers strongly suggests hydration of the lower stratosphere by geyser-like injection of ice particles over overshooting turrets. The pile-like increase of water vapour up to 19 km seen by the high-resolution hygrometer during the season of maximum temperature of the tropopause, suggests that the above hydration mechanism may contribute to the summer maximum moisture in the lower stratosphere. If this interpretation is correct, hydration by ice geysers across the tropopause might be an important contributor to the stratospheric water vapour budget.

  5. Study of plasma convection and wall interactions in magnetic-confinement systems. Progress report, October 1, 1980-September 30, 1981

    International Nuclear Information System (INIS)

    York, T.M.; Klevans, E.H.

    1981-01-01

    Experimental and analytical studies of plasma interactions with magnetic fields and end walls have been carried out. The final effort for studying flow on open-ended theta pinches has resulted in: (1) new understanding of collisional flow processes; and (2) has presented unique measurements of density and temperature near the end wall. An orignal effort to use Nd-glass lasers for Thomson scattering diagnostics is reported. Laser system conversion and efficiencies of frequency doubling are reported. The development of a compact toroid discharged is reported; this will be used as a plasma source to study transport, convection and wass interactions at plasma conditions appropriate for large scale fusion experiments. Computer codes predict compact toroid plasma scaling and magnetic field distribution resulting from guiding coils added at the ends of the theta pinch coil. The development of a multi-pass Fabry-Perot interferometer using visible light from a He-Ne laser is reported here. Theoretical study has been completed on an extension of a collisionless plasma flow model to include collision effects. Initial studies directed to analysis of plasma wall interactions are reported

  6. Experimental analysis of the natural convection system through a closed loop under transient regime

    International Nuclear Information System (INIS)

    Lavrador, Marcelo de Bastos; Braga, Carlos Valois Maciel; Carajilescov, Pedro

    1996-01-01

    This work presents the experimental model used in the study of closed loop natural convection (thermosyphons). Details of the main circuit and information on the used instrumentation are also presented. The study aimed the circuit thermal performance, initially justifying the oscillatory behaviour of the time vs. temperature curves. As expected, the curves for the cold leg presented an oscillation amplitude lesser than those for hot leg since the 'peaks' which reveal high temperature spots disappear due to the heat transfer to the cooling water. Those curves were not influenced within the measured range, by the changes occurred in the cooling water flow (secondary circuit). Besides, when varying the power supplied by the hot source it was observed a variation directly proportional of the oscillation frequency, of the oscillation amplitude, and the difference between the hot and cold legs temperatures. Concerning to the forced power variations, it is observed that the oscillation is always restarted and the final results are related to the second applied power

  7. Visualization of Two Phase Natural Convection Flow in a Vertical Pipe using the Sulfuric Acid - Copper Sulfate Electroplating System

    Energy Technology Data Exchange (ETDEWEB)

    Ohk, Seung-Min; Chae, Myeong-Seon; Chung, Bum-Jin [Kyung Hee Univ., Yongin (Korea, Republic of)

    2014-10-15

    The passive containment cooling system (PCCS) driven by natural forces convection gain draws research interests after Fukushima NPP accident. The PCCS was classified into three categories: Containment pressure suppression, Containment passive heat removal/pressure suppression systems and Passive containment spray. Among the types of containment passive heat removal/pressure suppression systems, the system composed of an internal heat exchanger and an external coolant tank is considered. In a severe accident condition, the heat from the containment atmosphere is transferred to the outer surface of the heat exchanger by the convection and condensation of the mixture of steam and gases. On the other hand, the heat is transferred to external pool by single phase or two phase natural convection inside of heat exchanger pipes. The study aimed at investigating the influence of the diameter (D) and height (H) of the heat exchanger pipes on the single phase and two phase natural convection heat transfer. As the initial stage of the study, the two phase natural convection flow inside a vertical pipe is visualized. In order to achieve the aim with ample test rig, a sulfuric acid - cooper sulfate electroplating system was employed based on the analogy between heat and mass transfer. The reduction of hydrogen ion at the cathode surface at high potential was used to simulate the boiling phenomena. This study tried to visualize the boiling heat transfer inside a vertical pipe using a cupric acid-copper sulfate (H{sub 2}SO{sub 4}-CuSO{sub 4}) electroplating system. This seems to be successful so far. However further study has to be done to compare the result with real two phase flow situation. The surface tension and surface characteristics are to be tuned to simulate the real situation.

  8. Moisture Sources and Life Cycle of Convective Systems over Western Colombia

    Directory of Open Access Journals (Sweden)

    Meiry Sayuri Sakamoto

    2011-01-01

    Full Text Available This paper describes life cycle and moisture sources of mesoscale convective systems (MCSs observed over western Colombia. Results show that, in general, MCS are more frequent during boreal summer and autumn, and particularly, systems observed in summer season present longer life and larger extension. On the continent, MCS genesis is strongly affected by sea breeze and diurnal heating and presents a peak from 15 to 18 LST. For oceanic systems, the main genesis period is later, from 00 to 03 LST. Continental and oceanic systems present a tendency of westward displacement. Analysis using a Lagrangian approach implemented to estimate air parcel trajectories suggests that, during boreal winter, the main moisture sources are from the Caribbean Sea and tropical north Atlantic, possibly resulting from the moisture-laden trade winds and the land-ocean temperature contrast over northern South America. In summer, it is clear the influence of ITCZ positioning with moisture particles traveling from the tropical Atlantic over Amazonian river basin. In Autumn, Chilean-Peruvian Pacific is the main moisture source, confirming the importance of Chocó low level jet to MCS genesis.

  9. Multi-Point Combustion System: Final Report

    Science.gov (United States)

    Goeke, Jerry; Pack, Spencer; Zink, Gregory; Ryon, Jason

    2014-01-01

    A low-NOx emission combustor concept has been developed for NASA's Environmentally Responsible Aircraft (ERA) program to meet N+2 emissions goals for a 70,000 lb thrust engine application. These goals include 75 percent reduction of LTO NOx from CAEP6 standards without increasing CO, UHC, or smoke from that of current state of the art. An additional key factor in this work is to improve lean combustion stability over that of previous work performed on similar technology in the early 2000s. The purpose of this paper is to present the final report for the NASA contract. This work included the design, analysis, and test of a multi-point combustion system. All design work was based on the results of Computational Fluid Dynamics modeling with the end results tested on a medium pressure combustion rig at the UC and a medium pressure combustion rig at GRC. The theories behind the designs, results of analysis, and experimental test data will be discussed in this report. The combustion system consists of five radially staged rows of injectors, where ten small scale injectors are used in place of a single traditional nozzle. Major accomplishments of the current work include the design of a Multipoint Lean Direct Injection (MLDI) array and associated air blast and pilot fuel injectors, which is expected to meet or exceed the goal of a 75 percent reduction in LTO NOx from CAEP6 standards. This design incorporates a reduced number of injectors over previous multipoint designs, simplified and lightweight components, and a very compact combustor section. Additional outcomes of the program are validation that the design of these combustion systems can be aided by the use of Computational Fluid Dynamics to predict and reduce emissions. Furthermore, the staging of fuel through the individually controlled radially staged injector rows successfully demonstrated improved low power operability as well as improvements in emissions over previous multipoint designs. Additional comparison

  10. Development of a system code with CFD capability for analyzing turbulent mixed convection in gas-cooled reactors

    International Nuclear Information System (INIS)

    Kim, Hyeon Il

    2010-02-01

    In order to demonstrate the accuracy of predictions in a turbulent mixed convection regime in which both inertia and buoyancy force compete with each other, we found out that assessments done using a single-dimensional system code with a recently updated heat transfer package have shown that this approach cannot give a reasonable prediction of the wall temperature in a case involving strong heating, where the regime falls into turbulent mixed convection regime. It has been known that the main reason of this deficiency comes from the degraded heat transfer in turbulent mixed convection regime, which is below that of convective heat transfer during turbulent forced convection. We investigated two mechanisms that cause this deterioration in convective heat transfer influenced by buoyancy: (1) modification of turbulence, also known as the direct (structural) effect, through the buoyancy-induced production of turbulent kinetic energy: and (2) an indirect (external) effect that occurs through modification of the mean flow. We investigated the Launder-Sharma model of turbulence whether it can appropriately represent the mechanisms causing the degraded heat transfer in Computational Fluid Dynamics (CFD). We found out that this model can capture low Re effects such that a non-equilibrium turbulent boundary layer in turbulent mixed convection regime can be resolved. The model was verified and validated extensively initially with the commercial CFD code, Fluent with a user application package known as the User Defined Function (UDF). The results from this implementation were compared to a set of data that included (1) an experimental data commonly accepted as a standardized problem to verify a turbulent flow, (2) the results from a Direct Numerical Simulation (DNS) in a turbulent forced and mixed convection regime, (3) empirical correlations regarding the friction coefficient and the non-dimensional heat transfer coefficient, the Nusselt number for a turbulent forced

  11. Modeling and analysis of a robust thermal control system based on forced convection thermal switches

    Science.gov (United States)

    Williams, Andrew D.; Palo, Scott E.

    2006-05-01

    There is a critical need, not just in the Department of Defense (DOD) but the entire space industry, to reduce the development time and overall cost of satellite missions. To that end, the DOD is actively pursuing the capability to reduce the deployment time of a new system from years to weeks or even days. The goal is to provide the advantages space affords not just to the strategic planner but also to the battlefield commanders. One of the most challenging aspects of this problem is the satellite's thermal control system (TCS). Traditionally the TCS must be vigorously designed, analyzed, tested, and optimized from the ground up for every satellite mission. This "reinvention of the wheel" is costly and time intensive. The next generation satellite TCS must be modular and scalable in order to cover a wide range of applications, orbits, and mission requirements. To meet these requirements a robust thermal control system utilizing forced convection thermal switches was investigated. The problem was investigated in two separate stages. The first focused on the overall design of the bus. The second stage focused on the overarching bus architecture and the design impacts of employing a thermal switch based TCS design. For the hot case, the fan provided additional cooling to increase the heat transfer rate of the subsystem. During the cold case, the result was a significant reduction in survival heater power.

  12. Experimental Investigation of Convective Heat Transfer during Night Cooling with Different Ventilation Systems and Surface Emissivities

    DEFF Research Database (Denmark)

    Le Dreau, Jerome; Heiselberg, Per; Jensen, Rasmus Lund

    2013-01-01

    models for convection. In a full-scale test room, the heat transfer was investigated during 12 h of discharge by night-time ventilation. A total of 34 experiments have been performed, with different ventilation types (mixing and displacement), air change rates, temperature differences between the inlet...... air and the room, and floor emissivities. This extensive experimental study enabled a detailed analysis of the convective and radiative flow at the different surfaces of the room. The experimentally derived convective heat transfer coefficients (CHTC) have been compared to existing correlations....... For mixing ventilation, existing correlations did not predict accurately the convective heat transfer at the ceiling due to differences in the experimental conditions. But the use of local parameters of the air flow showed interesting results to obtain more adaptive CHTC correlations. For displacement...

  13. Power optimization in the star-LM modular, natural convection reactor system

    International Nuclear Information System (INIS)

    Spencer, B.W.; Sienicki, J.J.; Farmer, M.T.

    2001-01-01

    The secure, transportable, autonomous reactor (STAR) project addresses the needs of developing countries and independent power producers for small, multi-purpose energy systems, which operate near autonomously for very long term. The STAR-LM variant described here is a liquid metal cooled, fast reactor system. Previous development of STAR-LM resulted in a 300 MWt modular, pool-type reactor based on criteria for factory fabrication, full transportability (barge, overland, rail), and fast construction and startup. Steam generator modules are placed directly into the primary heat transport circuit, eliminating the intermediate heat transport loop. Natural convection heat transport at all power levels eliminates the need for main coolant pumps. Seismic isolation eliminates concern about seismic and sloshing-related loads in the pool configuration. Even end-of-spectrum postulated events such as loss-of-heat sink with failure to scram are terminated passively by inherent core power shutdown, and decay heat is passively rejected to the atmospheric air inexhaustible heat sink by guard vessel exterior cooling. Recent concept development has focused on maximizing the power achievable in a small module size based on preserving key criteria for: full spectrum of modes of module transport from factory to site (including rail transport); 100% natural circulation heat transport; ultra-long core cartridge lifetime; coolant and cladding peak temperatures well within the existing (Russian) database for Pb/Bi coolant and ferritic steel core materials. (author)

  14. Simulation of the trajectory of microwaves during passage of Mesoescale Convective System over Southern Brazil

    Science.gov (United States)

    Diniz, F. L.; Munchow, G. B.; Herdies, D. L.; Foster, P. R.

    2010-12-01

    When the eletromagnetic wave travels in the atmosphere from one medium to another with different density and/or composition suffers small changes in speed and direction of propagation. These changes are caused by the vertical variation of atmospheric refractive index. This causes different types of trajectory deviations, which can be called: normal refraction, sub-refraction, super-refraction and duct. The condition to create duct is satisfied when there is a especific vertical profile of refraction, in this case an eletromagnectic wave will oscillate in a layer of the atmosphere. Considering that this ducts condition can causes damage in the transmission and reception of microwave system equipment (e.g. telecomunications, global positioning, weather radars and satellites) and that in the Rio Grande do Sul, state of Brazil, there are two weather radars, this study present a simulation of the trajectory that would have an eletromagnetic wave. In this study was used soundings of the atmosphere to infer the vertical profile of refractive index during the passage of a Mesoescale Convective System on September 7, 2009. In the lack of this data a numerical simulation with nested grids using Weather Research & Forecasting Model was performed to infer this.

  15. Retrievals of Ice Cloud Microphysical Properties of Deep Convective Systems using Radar Measurements

    Science.gov (United States)

    Tian, J.; Dong, X.; Xi, B.; Wang, J.; Homeyer, C. R.

    2015-12-01

    This study presents innovative algorithms for retrieving ice cloud microphysical properties of Deep Convective Systems (DCSs) using Next-Generation Radar (NEXRAD) reflectivity and newly derived empirical relationships from aircraft in situ measurements in Wang et al. (2015) during the Midlatitude Continental Convective Clouds Experiment (MC3E). With composite gridded NEXRAD radar reflectivity, four-dimensional (space-time) ice cloud microphysical properties of DCSs are retrieved, which is not possible from either in situ sampling at a single altitude or from vertical pointing radar measurements. For this study, aircraft in situ measurements provide the best-estimated ice cloud microphysical properties for validating the radar retrievals. Two statistical comparisons between retrieved and aircraft in situ measured ice microphysical properties are conducted from six selected cases during MC3E. For the temporal-averaged method, the averaged ice water content (IWC) and median mass diameter (Dm) from aircraft in situ measurements are 0.50 g m-3 and 1.51 mm, while the retrievals from radar reflectivity have negative biases of 0.12 g m-3 (24%) and 0.02 mm (1.3%) with correlations of 0.71 and 0.48, respectively. For the spatial-averaged method, the IWC retrievals are closer to the aircraft results (0.51 vs. 0.47 g m-3) with a positive bias of 8.5%, whereas the Dm retrievals are larger than the aircraft results (1.65 mm vs. 1.51 mm) with a positive bias of 9.3%. The retrieved IWCs decrease from ~0.6 g m-3 at 5 km to ~0.15 g m-3 at 13 km, and Dm values decrease from ~2 mm to ~0.7 mm at the same levels. In general, the aircraft in situ measured IWC and Dm values at each level are within one standard derivation of retrieved properties. Good agreements between microphysical properties measured from aircraft and retrieved from radar reflectivity measurements indicate the reasonable accuracy of our retrievals.

  16. Role of upper-level wind shear on the structure and maintenance of derecho-producing convective systems

    Science.gov (United States)

    Coniglio, Michael Charles

    Common large-scale environments associated with the development of derecho-producing convective systems from a large number of events are identified using statistical clustering of the 500-mb geopotential heights as guidance. The majority of the events (72%) fall into three main patterns that include a well-defined upstream trough (40%), a ridge (20%), and a zonal, low-amplitude flow (12%), which is defined as an additional warm-season pattern that is not identified in past studies of derecho environments. Through an analysis of proximity soundings, discrepancies are found in both low-level and deep-tropospheric shear parameters between observations and the shear profiles considered favorable for strong, long-lived convective systems in idealized simulations. To explore the role of upper-level shear in derecho environments, a set of two-dimensional simulations of density currents within a dry, neutrally stable environment are used to examine the ability of a cold pool to lift environmental air within a vertically sheared flow. The results confirm that the addition of upper-level shear to a wind profile with weak to moderate low-level shear increases the vertical displacement of low-level parcels despite a decrease in the vertical velocity along the cold pool interface, as suggested by previous studies. Parcels that are elevated above the surface (1-2 km) overturn and are responsible for the deep lifting in the deep-shear environments. This deep overturning caused by the upper-level shear helps to maintain the tilt of the convective systems in more complex two-dimensional and three dimensional simulations. The overturning also is shown to greatly increase the size of the convective systems in the three-dimensional simulations by facilitating the initiation and maintenance of convective cells along the cold pool. When combined with estimates of the cold pool motion and the storm-relative hodograph, these results may best be used for the prediction of the demise of

  17. Automated Tracking of Tornado-Producing Mesoscale Convective Systems in the United States

    Science.gov (United States)

    Kuo, K.; Hong, Y.; Clune, T. L.

    2011-12-01

    The great majority of Earth Science events are studied using "snap-shot" observations in time, mainly due to the scarcity of observations with dense temporal coverage and the lack of robust methods amenable to connecting the "snap shots". To enable the studies of these events in the four-dimensional (4D) spatiotemporal space and to demonstrate the utility of this capability, we have applied the neighbor enclosed area tracking (NEAT) method of Inatsu (2009) to three years of high-resolution (in both time and space) NEXRAD-derived and rain-gauge-corrected QE2 precipitation observations and GOES satellite Rapid Scan Operation imagery to track tornado-producing mesoscale convective systems (MCS's). We combine information from the databases of the Tornado History Project (which provides tornado occurrence and trajectory) and the NWS Watch/Warning Archive (which provides severe weather watch/warning locations) to obtain initial estimate of the time and location of a tornado-producing MCS. The NEAT algorithm is then applied to QE2 and GOES data, both forward and backward in time, to identify the entire system as one integral entity from its inception to its eventual dissipation in the 4D spatiotemporal space. For each system so identified, we extract its morphological/structural parameters, such as perimeter length, area, and orientation, from each of the snap shots in time. We also record physical parameters such as minimum and maximum precipitation rates. In addition, we perform areal integral on the precipitation rate field, which in turn enables time integral for the entire MCS throughout its lifecycle to obtain an estimate of the system's precipitation production. We can extend this proof-of-concept prototype to other precipitation producing severe weather events, such as blizzards. Furthermore, the spatiotemporal data collected may be used to discover other data, such as satellite remote sensing observations and model analyses/simulations, which can then be combined

  18. Controls on water vapor isotopes over Roorkee, India: Impact of convective activities and depression systems

    Science.gov (United States)

    Saranya, P.; Krishan, Gopal; Rao, M. S.; Kumar, Sudhir; Kumar, Bhishm

    2018-02-01

    The study evaluates the water vapor isotopic compositions and its controls with special reference to Indian Summer Monsoon (ISM) season at Roorkee, India. Precipitation is usually a discrete event spatially and temporally in this part of the country, therefore, the information provided is limited, while, the vapors have all time availability and have a significant contribution in the hydrological cycle locally or over a regional scale. Hence for understanding the processes altering the various sources, its isotopic signatures were studied. The Isotope Water Vapour Line (Iso Val) was drawn together with the Global Meteoric Water Line (GMWL) and the best fit line was δD = 5.42 * δ18O + 27.86. The precipitation samples were also collected during the study period and were best fitted with δD = 8.20(±0.18) * δ18O + 9.04(±1.16) in the Local Meteoric Water Line (LMWL). From the back trajectory analysis of respective vapor samples, it is unambiguous that three major sources viz; local vapor, western disturbance and monsoon vapor are controlling the fate of moisture over Roorkee. The d-excess in ground-level vapor (GLV) reveals the supply of recycled moisture from continental water bodies and evapo-transpiration as additional moisture sources to the study area. The intensive depletion in isotopic ratios was associated with the large-scale convective activity and low-pressure/cyclonic/depression systems formed over Bay of Bengal.

  19. Development of Final Running Test System for Digital Systems

    International Nuclear Information System (INIS)

    Lee, Kwang-Dae; Lee, Eui-Jong; Lim, Hee-Taek; Kim, Min-Seok

    2016-01-01

    In nuclear industry, the newly designed systems to upgrade are qualified to meet IEEE standards and the regulatory guidelines for their functions, performance and reliability requirements. Failure Mode and Effect Analysis, Fault Tree Analysis, and Hazard Analysis have been used to improve the reliability of the control system. To ensure the completeness of the software, the verification and validation processes are carried out during the development process. In spite of the many efforts depending on the analysis and procedures, there are limitations to improve the reliability. The lessons learned from the currently installed system failures show the incompleteness of the final integration test. The current point-to-point and logic-to-logic separate test procedures manually performed by the engineers can cause some procedures missed and have effects on the critical functions. The design processes of the digital systems are met in accordance with the international standards and regulatory guidelines. The lessons learned from the failures of the running digital systems showed the limitations of the current verification and validation efforts. The various improvements and attempts have been considered including the expert review processes and the completeness of the test. In this paper, the Final Running Test Method evaluating the completeness of the digital system using the control patterns and the Test System Architecture are proposed

  20. Development of Final Running Test System for Digital Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang-Dae; Lee, Eui-Jong; Lim, Hee-Taek; Kim, Min-Seok [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In nuclear industry, the newly designed systems to upgrade are qualified to meet IEEE standards and the regulatory guidelines for their functions, performance and reliability requirements. Failure Mode and Effect Analysis, Fault Tree Analysis, and Hazard Analysis have been used to improve the reliability of the control system. To ensure the completeness of the software, the verification and validation processes are carried out during the development process. In spite of the many efforts depending on the analysis and procedures, there are limitations to improve the reliability. The lessons learned from the currently installed system failures show the incompleteness of the final integration test. The current point-to-point and logic-to-logic separate test procedures manually performed by the engineers can cause some procedures missed and have effects on the critical functions. The design processes of the digital systems are met in accordance with the international standards and regulatory guidelines. The lessons learned from the failures of the running digital systems showed the limitations of the current verification and validation efforts. The various improvements and attempts have been considered including the expert review processes and the completeness of the test. In this paper, the Final Running Test Method evaluating the completeness of the digital system using the control patterns and the Test System Architecture are proposed.

  1. Measuring the vertical electrical field above an oceanic convection system using a meteorological sounding balloon

    Science.gov (United States)

    Chen, A. B.; Chiu, C.; Lai, S.; Chen, C.; Kuo, C.; Su, H.; Hsu, R.

    2012-12-01

    The vertical electric field above thundercloud plays an important role in the generation and modeling of transient luminous events. For example, Pasko [1995] proposed that the high quasi-static E-field following the positive cloud-to-ground lightning could accelerate and input energy to ambient electrons; as they collide and excite nitrogen and oxygen molecules in upper atmosphere, sprites may be induced. A series of balloon experiments led by Holzworth have investigated the temporal and spatial fluctuations of the electric field and conductivity in the upper atmosphere at different sites [Holzworth 2005, and references in]. But the strength and variation of the vertical electric field above thundercloud, especially oceanic ones, are not well documented so far. A lightweight, low-cost measurement system including an electric field meter and the associated aviation electronics are developed to carry out the in-situ measurement of the vertical electric field and the inter-cloud charge distribution. Our measuring system was first deployed using a meteorological sounding balloon from Taitung, Taiwan in May 2012. The measured electric field below 3km height shows an exponential decay and it is consistent with the expected potential gradient variation between ionosphere and the Earth surface. But the background strength of the measured E-field grows up exponentially and a violent fluctuations is also observed when the balloon flew over a developing oceanic convection cell. The preliminary results from this flight will be reported and discussed. This low-cost electric field meter is developed within one year. In the coming months, more flights will be performed with the aim to measure the rapid variation of the electric field above thundercloud as well as the E-field that may induce transient luminous events. Our ground campaigns show that the occurrence rates of blue and gigantic jet are relatively high in the vicinity of Taiwan. Our experiment can be used to diagnose

  2. Pattern selection in single-component systems coupling Benard convection and solidification

    International Nuclear Information System (INIS)

    Davis, S.H.; Mueller, U.; Dietsche, C.

    1983-12-01

    A horizontal layer is heated from below and cooled from above so that the enclosed single-component liquid is frozen in the upper part of the layer. When the imposed temperature difference is such that the Rayleigh number across the liquid is supercritical, there is Benard convection coupled with the dynamics of the solidification interface. An experiment is presented which shows that the interfacial corrugations that result are two-dimensional when this ''ice'' is thin but hexagonal when the ''ice'' is thick. A weakly-nonlinear convective instability theory is presented which explains this behavior, and isolates the mechanism of the pattern selection. Jump behavior is seen in the liquid-layer thickness at the onset of hexagonal convection. (orig.) [de

  3. Impact of Assimilation of Conventional and Satellite Radiance GTS Observations on Simulation of Mesoscale Convective System Over Southeast India Using WRF-3DVar

    Science.gov (United States)

    Madhulatha, A.; Rajeevan, M.; Bhowmik, S. K. Roy; Das, A. K.

    2018-01-01

    The primary goal of present study is to investigate the impact of assimilation of conventional and satellite radiance observations in simulating the mesoscale convective system (MCS) formed over south east India. An assimilation methodology based on Weather Research and Forecasting model three dimensional variational data assimilation is considered. Few numerical experiments are carried out to examine the individual and combined impact of conventional and non-conventional (satellite radiance) observations. After the successful inclusion of additional observations, strong analysis increments of temperature and moisture fields are noticed and contributed to significant improvement in model's initial fields. The resulting model simulations are able to successfully reproduce the prominent synoptic features responsible for the initiation of MCS. Among all the experiments, the final experiment in which both conventional and satellite radiance observations assimilated has showed considerable impact on the prediction of MCS. The location, genesis, intensity, propagation and development of rain bands associated with the MCS are simulated reasonably well. The biases of simulated temperature, moisture and wind fields at surface and different pressure levels are reduced. Thermodynamic, dynamic and vertical structure of convective cells associated with the passage of MCS are well captured. Spatial distribution of rainfall is fairly reproduced and comparable to TRMM observations. It is demonstrated that incorporation of conventional and satellite radiance observations improved the local and synoptic representation of temperature, moisture fields from surface to different levels of atmosphere. This study highlights the importance of assimilation of conventional and satellite radiances in improving the models initial conditions and simulation of MCS.

  4. Numerical Modeling of Conjugate Thermogravitational Convection in a Closed System with a Radiant Energy Source in Conditions of Convective-Radiative Heat Exchange at the External Boundary

    Directory of Open Access Journals (Sweden)

    Nee Alexander

    2016-01-01

    Full Text Available Mathematical modeling of conjugate natural convection in a closed rectangular cavity with a radiant energy source in conditions of convective-radiative heat exchange at the external boundary was conducted. The radiant energy distribution was set by the Lambert’s law. Conduction and convection processes analysis showed that the air masses flow pattern is modified slightly over the time. The temperature increases in the gas cavity, despite the heat removal from the one of the external boundary. According to the results of the integral heat transfer analysis were established that the average Nusselt number (Nuav increasing occurs up to τ = 200 (dimensionless time. Further Nuav has changed insignificantly due to the temperature field equalization near the interfaces “gas – wall”.

  5. Seasonal and Intraseasonal Variability of Mesoscale Convective Systems over the South Asian Monsoon Region

    Energy Technology Data Exchange (ETDEWEB)

    Virts, Katrina S.; Houze, Robert A.

    2016-12-01

    Seasonal and intraseasonal differences in mesoscale convective systems (MCSs) over South Asia are examined using A-Train satellites, a ground-based lightning network, and reanalysis fields. Pre-monsoon (April-May) MCSs occur primarily over Bangladesh and the eastern Bay of Bengal. During the monsoon (June-September), small MCSs occur over the Meghalaya Plateau and northeast Himalayan notch, while large and connected MCSs are most widespread over the Bay of Bengal. Monsoon MCSs produce less lightning and exhibit more extensive stratiform and anvil reflectivity structures in CloudSat observations than do pre-monsoon MCSs. During the monsoon season, Bay of Bengal and Meghalaya Plateau MCSs vary with the 30-60 day northward-propagating intraseasonal oscillation, while northeast Himalayan notch MCSs are associated with weak large-scale anomalies but locally enhanced CAPE. During intraseasonal active periods, a zone of enhanced large and connected MCSs, precipitation, and lightning extends from the northeastern Arabian Sea southeast over India and the Bay of Bengal, flanked by suppressed anomalies. Spatial variability is observed within this enhancement zone: lightning is most enhanced where MCSs are less enhanced, and vice versa. Reanalysis composites indicate that Bay of Bengal MCSs are associated with monsoon depressions, which are frequent during active monsoon periods, while Meghalaya Plateau MCSs are most frequent at the end of break periods, as anomalous southwesterly winds strengthen moist advection toward the terrain. Over both regions, MCSs exhibit more extensive stratiform and anvil regions and less lightning when the large-scale environment is moister, and vice versa.

  6. Liquid waste treatment system. Final report

    International Nuclear Information System (INIS)

    Baker, M.N.; Houston, H.M.

    1999-01-01

    Pretreatment of high-level liquid radioactive waste (HLW) at the West Valley Demonstration Project (WVDP) involved three distinct processing operations: decontamination of liquid HLW in the Supernatant Treatment System (STS); volume reduction of decontaminated liquid in the Liquid Waste Treatment System (LWTS); and encapsulation of resulting concentrates into an approved cement waste form in the Cement Solidification System (CSS). Together, these systems and operations made up the Integrated Radwaste Treatment System (IRTS)

  7. Chromatic correction for the final transport system

    International Nuclear Information System (INIS)

    Brown, K.L.; Peterson, J.M.

    1980-01-01

    The final transport and focusing of the heavy-ion beam onto the fusion pellet in vacuum is complicated by several non-linear effects - namely, chromatic (momentum dependent) effects, geometric aberrations, and space-charge forces. This paper gives an example of how the chromatic effects can be nullified, at least to second order. Whether third- or higher-order terms are important is not yet clear. Space-charge effects are important but are not considered here

  8. LANL environmental restoration site ranking system: System description. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Merkhofer, L.; Kann, A.; Voth, M. [Applied Decision Analysis, Inc., Menlo Park, CA (United States)

    1992-10-13

    The basic structure of the LANL Environmental Restoration (ER) Site Ranking System and its use are described in this document. A related document, Instructions for Generating Inputs for the LANL ER Site Ranking System, contains detailed descriptions of the methods by which necessary inputs for the system will be generated. LANL has long recognized the need to provide a consistent basis for comparing the risks and other adverse consequences associated with the various waste problems at the Lab. The LANL ER Site Ranking System is being developed to help address this need. The specific purpose of the system is to help improve, defend, and explain prioritization decisions at the Potential Release Site (PRS) and Operable Unit (OU) level. The precise relationship of the Site Ranking System to the planning and overall budget processes is yet to be determined, as the system is still evolving. Generally speaking, the Site Ranking System will be used as a decision aid. That is, the system will be used to aid in the planning and budgetary decision-making process. It will never be used alone to make decisions. Like all models, the system can provide only a partial and approximate accounting of the factors important to budget and planning decisions. Decision makers at LANL will have to consider factors outside of the formal system when making final choices. Some of these other factors are regulatory requirements, DOE policy, and public concern. The main value of the site ranking system, therefore, is not the precise numbers it generates, but rather the general insights it provides.

  9. LANL environmental restoration site ranking system: System description. Final report

    International Nuclear Information System (INIS)

    Merkhofer, L.; Kann, A.; Voth, M.

    1992-01-01

    The basic structure of the LANL Environmental Restoration (ER) Site Ranking System and its use are described in this document. A related document, Instructions for Generating Inputs for the LANL ER Site Ranking System, contains detailed descriptions of the methods by which necessary inputs for the system will be generated. LANL has long recognized the need to provide a consistent basis for comparing the risks and other adverse consequences associated with the various waste problems at the Lab. The LANL ER Site Ranking System is being developed to help address this need. The specific purpose of the system is to help improve, defend, and explain prioritization decisions at the Potential Release Site (PRS) and Operable Unit (OU) level. The precise relationship of the Site Ranking System to the planning and overall budget processes is yet to be determined, as the system is still evolving. Generally speaking, the Site Ranking System will be used as a decision aid. That is, the system will be used to aid in the planning and budgetary decision-making process. It will never be used alone to make decisions. Like all models, the system can provide only a partial and approximate accounting of the factors important to budget and planning decisions. Decision makers at LANL will have to consider factors outside of the formal system when making final choices. Some of these other factors are regulatory requirements, DOE policy, and public concern. The main value of the site ranking system, therefore, is not the precise numbers it generates, but rather the general insights it provides

  10. Benchmark Analyses of Sodium Natural Convection in the Upper Plenum of the Monju Reactor Vessel. Final Report of a Coordinated Research Project 2008-2012

    International Nuclear Information System (INIS)

    2014-11-01

    The IAEA supports Member States in the area of advanced fast reactor technology development by providing a major fulcrum for information exchange and collaborative research programmes. The IAEA’s activities in this field are mainly carried out within the framework of the Technical Working Group on Fast Reactors (TWG-FR), which assists in the implementation of corresponding IAEA support, and ensures that all technical activities are in line with expressed needs of Member States. Among this broad range, the IAEA proposes and establishes coordinated research projects (CRPs), aimed at improving Member State capability in fast reactor design and analysis. An important opportunity to perform collaborative research activities was provided by the system startup tests carried out by the Japan Atomic Energy Agency (JAEA) in the prototype loop type sodium cooled fast reactor Monju, in particular a turbine trip test performed in December 1995. As the JAEA opened the experimental dataset to international collaboration in 2008, the IAEA launched the CRP on Benchmark Analyses of Sodium Natural Convection in the Upper Plenum of the Monju Reactor Vessel. The CRP, together with eight institutes from seven States, has contributed to improving capabilities in sodium cooled fast reactors simulation through code verification and validation, with particular emphasis on thermal stratification and natural circulation phenomena

  11. Large-scale thermal convection of viscous fluids in a faulted system: 3D test case for numerical codes

    Science.gov (United States)

    Magri, Fabien; Cacace, Mauro; Fischer, Thomas; Kolditz, Olaf; Wang, Wenqing; Watanabe, Norihiro

    2017-04-01

    In contrast to simple homogeneous 1D and 2D systems, no appropriate analytical solutions exist to test onset of thermal convection against numerical models of complex 3D systems that account for variable fluid density and viscosity as well as permeability heterogeneity (e.g. presence of faults). Owing to the importance of thermal convection for the transport of energy and minerals, the development of a benchmark test for density/viscosity driven flow is crucial to ensure that the applied numerical models accurately simulate the physical processes at hands. The presented study proposes a 3D test case for the simulation of thermal convection in a faulted system that accounts for temperature dependent fluid density and viscosity. The linear stability analysis recently developed by Malkovsky and Magri (2016) is used to estimate the critical Rayleigh number above which thermal convection of viscous fluids is triggered. The numerical simulations are carried out using the finite element technique. OpenGeoSys (Kolditz et al., 2012) and Moose (Gaston et al., 2009) results are compared to those obtained using the commercial software FEFLOW (Diersch, 2014) to test the ability of widely applied codes in matching both the critical Rayleigh number and the dynamical features of convective processes. The methodology and Rayleigh expressions given in this study can be applied to any numerical model that deals with 3D geothermal processes in faulted basins as by example the Tiberas Basin (Magri et al., 2016). References Kolditz, O., Bauer, S., Bilke, L., Böttcher, N., Delfs, J. O., Fischer, T., U. J. Görke, T. Kalbacher, G. Kosakowski, McDermott, C. I., Park, C. H., Radu, F., Rink, K., Shao, H., Shao, H.B., Sun, F., Sun, Y., Sun, A., Singh, K., Taron, J., Walther, M., Wang,W., Watanabe, N., Wu, Y., Xie, M., Xu, W., Zehner, B., 2012. OpenGeoSys: an open-source initiative for numerical simulation of thermo-hydro-mechanical/chemical (THM/C) processes in porous media. Environmental

  12. Solar thermal repowering systems integration. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dubberly, L. J.; Gormely, J. E.; McKenzie, A. W.

    1979-08-01

    This report is a solar repowering integration analysis which defines the balance-of-plant characteristics and costs associated with the solar thermal repowering of existing gas/oil-fired electric generating plants. Solar repowering interface requirements for water/steam and salt or sodium-cooled central receivers are defined for unit sizes ranging from 50 MWe non-reheat to 350 MWe reheat. Finally balance-of-plant cost estimates are presented for each of six combinations of plant type, receiver type and percent solar repowering.

  13. Numerical Analyses of a single-phase natural convection system for Molten Flibe using MARS-FLIBE code

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sarah; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    These advantages make the MSR attractive and to be one of the six candidates for the Generation IV Reactor. Therefore, the researches related to the MSR are being conducted. To analyze the molten salt-cooled systems in the laboratory, this study generated the properties of molten salt using MARS-LMR. In this research, the implemented salts were Flibe (LiF-BeF{sub 2}) in a molar mixture that is 66% LiF and 34% BeF{sub 2}, respectively. Table 1 indicates the comparison of thermal properties of various coolants in nuclear power plants. Molten salt was added to the MARS-LMR code to support the analysis of Flibe-cooled systems. The molten salt includes LiF-BeF{sub 2} in a molar mixture that is 66% LiF and 34% BeF{sub 2}, respectively. MARS-LMR code for liquid metals uses the soft sphere model based on Monte Carlo calculations for particles interacting with pair potentials. Although MARS was originally intended for a safety analysis of light water reactor, Flibe properties were newly added to this code as so-called MARS-FLIBE which is applicable for Flibe-cooled systems. By using this thermodynamic property table file, the thermal hydraulic systems of Flibe can be simulated for numerical and parametric studies. In this study, the natural convection phenomena in the rectangular natural convection loop and IVR-ERVC in APR 1400 were simulated. Through the simulations in Flibe-cooled systems, the temperature distribution and mass flowrate of Flibe can be calculated and the heat transfer coefficients of Flibe in natural convection loop will be calculated by adding the related heat transfer correlations in the MARS-FLIBE code. MARS-FLIBE code will be used to predict and design of Flibe-cooled systems.

  14. Photovoltaic systems concept study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1977-04-01

    The work performed in the conceptual design and systems analysis of three sizes of photovoltaic solar electric power systems is contained in five volumes consisting of nine sections plus appendices. Separate abstracts were prepared for the two sections in this volume. (MHR)

  15. Heat Convection

    Science.gov (United States)

    Jiji, Latif M.

    Professor Jiji's broad teaching experience lead him to select the topics for this book to provide a firm foundation for convection heat transfer with emphasis on fundamentals, physical phenomena, and mathematical modelling of a wide range of engineering applications. Reflecting recent developments, this textbook is the first to include an introduction to the challenging topic of microchannels. The strong pedagogic potential of Heat Convection is enhanced by the follow ing ancillary materials: (1) Power Point lectures, (2) Problem Solutions, (3) Homework Facilitator, and, (4) Summary of Sections and Chapters.

  16. The response of a simulated mesoscale convective system to increased aerosol pollution: Part I: Precipitation intensity, distribution, and efficiency

    Science.gov (United States)

    Clavner, Michal; Cotton, William R.; van den Heever, Susan C.; Saleeby, Stephen M.; Pierce, Jeffery R.

    2018-01-01

    Mesoscale Convective Systems (MCSs) are important contributors to rainfall in the High Plains of the United States and elsewhere in the world. It is therefore of interest to understand how different aerosols serving as cloud condensation nuclei (CCN) may impact the total amount, rates and spatial distribution of precipitation produced by MCSs. In this study, different aerosol concentrations and their effects on precipitation produced by an MCS are examined by simulating the 8 May 2009 "Super-Derecho" MCS using the Regional Atmospheric Modeling System (RAMS), a cloud-resolving model (CRM) with sophisticated aerosol and microphysical parameterizations. Three simulations were conducted that differed only in the initial concentration, spatial distribution, and chemical composition of aerosols. Aerosol fields were derived from the output of GEOS-Chem, a 3D chemical transport numerical model. Results from the RAMS simulations show that the total domain precipitation was not significantly affected by variations in aerosol concentrations, however, the pollution aerosols altered the precipitation characteristics. The more polluted simulations exhibited higher precipitation rates, higher bulk precipitation efficiency, a larger area with heavier precipitation, and a smaller area with lighter precipitation. These differences arose as a result of aerosols enhancing precipitation in the convective region of the MCS while suppressing precipitation from the MCS's stratiform-anvil. In the convective region, several processes likely contributed to an increase of precipitation. First, owing to the very humid environment of this storm, the enhanced amount of cloud water available to be collected overwhelmed the reduction in precipitation efficiency associated with the aerosol-induced production of smaller droplets which led to a net increase in the conversion of cloud droplets to precipitation. Second, higher aerosol concentrations led to invigoration of convective updrafts which

  17. Proximity sensor system development. CRADA final report

    International Nuclear Information System (INIS)

    Haley, D.C.; Pigoski, T.M.

    1998-01-01

    Lockheed Martin Energy Research Corporation (LMERC) and Merritt Systems, Inc. (MSI) entered into a Cooperative Research and Development Agreement (CRADA) for the development and demonstration of a compact, modular proximity sensing system suitable for application to a wide class of manipulator systems operated in support of environmental restoration and waste management activities. In teleoperated modes, proximity sensing provides the manipulator operator continuous information regarding the proximity of the manipulator to objects in the workspace. In teleoperated and robotic modes, proximity sensing provides added safety through the implementation of active whole arm collision avoidance capabilities. Oak Ridge National Laboratory (ORNL), managed by LMERC for the United States Department of Energy (DOE), has developed an application specific integrated circuit (ASIC) design for the electronics required to support a modular whole arm proximity sensing system based on the use of capacitive sensors developed at Sandia National Laboratories. The use of ASIC technology greatly reduces the size of the electronics required to support the selected sensor types allowing deployment of many small sensor nodes over a large area of the manipulator surface to provide maximum sensor coverage. The ASIC design also provides a communication interface to support sensor commands from and sensor data transmission to a distributed processing system which allows modular implementation and operation of the sensor system. MSI is a commercial small business specializing in proximity sensing systems based upon infrared and acoustic sensors

  18. Proximity sensor system development. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Haley, D.C. [Oak Ridge National Lab., TN (United States); Pigoski, T.M. [Merrit Systems, Inc. (United States)

    1998-01-01

    Lockheed Martin Energy Research Corporation (LMERC) and Merritt Systems, Inc. (MSI) entered into a Cooperative Research and Development Agreement (CRADA) for the development and demonstration of a compact, modular proximity sensing system suitable for application to a wide class of manipulator systems operated in support of environmental restoration and waste management activities. In teleoperated modes, proximity sensing provides the manipulator operator continuous information regarding the proximity of the manipulator to objects in the workspace. In teleoperated and robotic modes, proximity sensing provides added safety through the implementation of active whole arm collision avoidance capabilities. Oak Ridge National Laboratory (ORNL), managed by LMERC for the United States Department of Energy (DOE), has developed an application specific integrated circuit (ASIC) design for the electronics required to support a modular whole arm proximity sensing system based on the use of capacitive sensors developed at Sandia National Laboratories. The use of ASIC technology greatly reduces the size of the electronics required to support the selected sensor types allowing deployment of many small sensor nodes over a large area of the manipulator surface to provide maximum sensor coverage. The ASIC design also provides a communication interface to support sensor commands from and sensor data transmission to a distributed processing system which allows modular implementation and operation of the sensor system. MSI is a commercial small business specializing in proximity sensing systems based upon infrared and acoustic sensors.

  19. Solar radiation alert system : final report.

    Science.gov (United States)

    2009-03-01

    The Solar Radiation Alert (SRA) system continuously evaluates measurements of high-energy protons made by instruments on GOES satellites. If the measurements indicate a substantial elevation of effective dose rates at aircraft flight altitudes, the C...

  20. Intelligent Transportation Systems statewide architecture : final report.

    Science.gov (United States)

    2003-06-01

    This report describes the development of Kentuckys Statewide Intelligent Transportation Systems (ITS) Architecture. The process began with the development of an ITS Strategic Plan in 1997-2000. A Business Plan, developed in 2000-2001, translated t...

  1. Traffic Management Systems Performance Measurement: Final Report

    OpenAIRE

    Banks, James H.; Kelly, Gregory

    1997-01-01

    This report documents a study of performance measurement for Transportation Management Centers (TMCs). Performance measurement requirements were analyzed, data collection and management techniques were investigated, and case study traffic data system improvement plans were prepared for two Caltrans districts.

  2. Water-storage-tube systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hemker, P.

    1981-12-24

    Passive solar collection/storage/distribution systems were surveyed, designed, fabricated, and mechanically and thermally tested. The types studied were clear and opaque fiberglass tubes, metal tubes with plastic liners, and thermosyphoning tubes. (MHR)

  3. PV Systems Reliability Final Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Lavrova, Olga [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flicker, Jack David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Jay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Armijo, Kenneth Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gonzalez, Sigifredo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schindelholz, Eric John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorensen, Neil R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yang, Benjamin Bing-Yeh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The continued exponential growth of photovoltaic technologies paves a path to a solar-powered world, but requires continued progress toward low-cost, high-reliability, high-performance photovoltaic (PV) systems. High reliability is an essential element in achieving low-cost solar electricity by reducing operation and maintenance (O&M) costs and extending system lifetime and availability, but these attributes are difficult to verify at the time of installation. Utilities, financiers, homeowners, and planners are demanding this information in order to evaluate their financial risk as a prerequisite to large investments. Reliability research and development (R&D) is needed to build market confidence by improving product reliability and by improving predictions of system availability, O&M cost, and lifetime. This project is focused on understanding, predicting, and improving the reliability of PV systems. The two areas being pursued include PV arc-fault and ground fault issues, and inverter reliability.

  4. Analysis of Hybrid Hydrogen Systems: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dean, J.; Braun, R.; Munoz, D.; Penev, M.; Kinchin, C.

    2010-01-01

    Report on biomass pathways for hydrogen production and how they can be hybridized to support renewable electricity generation. Two hybrid systems were studied in detail for process feasibility and economic performance. The best-performing system was estimated to produce hydrogen at costs ($1.67/kg) within Department of Energy targets ($2.10/kg) for central biomass-derived hydrogen production while also providing value-added energy services to the electric grid.

  5. Final report on the FMIT Control System

    International Nuclear Information System (INIS)

    Johnson, J.A.

    1985-01-01

    The computer control system for the Fusion Materials Irradiation Test Facility (FMIT) prototype accelerator was designed using distributed intelligence driven by a distributed database. The system consists of two minicomputers in the central control room and four microcomputers residing in CAMAC crates located near appropriate subsystems of the accelerator. The system uses single vendor hardware as much as practical in an attempt to minimize the maintenance problems. Local control consoles are an integral part of each node computer to provide subsystem check-out. The main console is located in the central control room and permits one-point operation of the complete control system. Automatic surveillance is provided for each data channel by the node computer with out-of-bounds alarms sent to the main console. Report by exception is used for data logging. This control system has been operational for two years. The computers are too heavily loaded and the operator response is slower than desired. A system upgrade to a faster local-area network has been undertaken and is scheduled to be operational by conference time

  6. Advanced Quasioptical Launcher System. Final Report

    International Nuclear Information System (INIS)

    Neilson, Jeffrey

    2010-01-01

    This program developed an analytical design tool for designing antenna and mirror systems to convert whispering gallery RF modes to Gaussian or HE11 modes. Whispering gallery modes are generated by gyrotrons used for electron cyclotron heating of fusion plasmas in tokamaks. These modes cannot be easily transmitted and must be converted to free space or waveguide modes compatible with transmission line systems.This program improved the capability of SURF3D/LOT, which was initially developed in a previous SBIR program. This suite of codes revolutionized quasi-optical launcher design, and this code, or equivalent codes, are now used worldwide. This program added functionality to SURF3D/LOT to allow creating of more compact launcher and mirror systems and provide direct coupling to corrugated waveguide within the vacuum envelope of the gyrotron. Analysis was also extended to include full-wave analysis of mirror transmission line systems. The code includes a graphical user interface and is available for advanced design of launcher systems.

  7. NKS MOMS. Final report. [Mobile Measurement Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nilssen, J. [Norwegian Radiation Protection Authority (NRPA) (Norway); Aage, H.K. [Danish Emergency Management Agency (DEMA) (Denmark); Palsson, S.E. [Icelandic Radiation Safety Authority (IRSA) (Iceland)

    2013-02-15

    Mobile car-borne measurement systems are an important asset in early phase emergency response in all Nordic countries. However, through the development of the systems in the different countries, there are considerable differences between the systems developed. This complicates Nordic cooperation and mutual assistance in emergency situations. This project aimed to facilitate harmonization of mobile measurement systems between the Nordic countries. The project focused on harmonizing data formats, information exchange and measurement strategies. Although the work done was funded by each member, the project established a good platform for cooperation which will hopefully continue beyond the scope of the project. A two-day seminar was held in May 2012, where all participants presented the current status (equipment, methods used etc.), in addition to invited speakers presenting development within the field of mobile detection and in situ measurements. Exchange of experiences and information on different measurement systems and practises in use was an important part of the seminar. The seminar was followed up by a small workshop during the REFOX exercise in Lund, Sweden, September 2012. Exchange of measurement data from the exercise was facilitated through a workspace proveded by NRPA as part of the MOMS project. The work done in this project will be presented at the NordEx12 seminar in March 2013. (Author)

  8. Topological defects after a quench in a Bénard-Marangoni convection system.

    Science.gov (United States)

    Casado, S; González-Viñas, W; Mancini, H; Boccaletti, S

    2001-05-01

    We report experimental evidence of the fact that, in a Bénard-Marangoni conduction-convection transition, the density of defects in the emerging structure scales as a power law in the quench time needed for the control parameter to ramp through the threshold. The obtained scaling exponents differ from the ones predicted and observed in the case in which the defects correspond to zeros in the amplitude of the global two-dimensional field.

  9. Sequencing Information Management System (SIMS). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fields, C.

    1996-02-15

    A feasibility study to develop a requirements analysis and functional specification for a data management system for large-scale DNA sequencing laboratories resulted in a functional specification for a Sequencing Information Management System (SIMS). This document reports the results of this feasibility study, and includes a functional specification for a SIMS relational schema. The SIMS is an integrated information management system that supports data acquisition, management, analysis, and distribution for DNA sequencing laboratories. The SIMS provides ad hoc query access to information on the sequencing process and its results, and partially automates the transfer of data between laboratory instruments, analysis programs, technical personnel, and managers. The SIMS user interfaces are designed for use by laboratory technicians, laboratory managers, and scientists. The SIMS is designed to run in a heterogeneous, multiplatform environment in a client/server mode. The SIMS communicates with external computational and data resources via the internet.

  10. The final fate of planetary systems

    Science.gov (United States)

    Gaensicke, Boris

    2015-12-01

    The discovery of the first extra-solar planet around a main-sequence star in 1995 has changed the way we think about the Universe: our solar system is not unique. Twenty years later, we know that planetary systems are ubiquitous, orbit stars spanning a wide range in mass, and form in an astonishing variety of architectures. Yet, one fascinating aspect of planetary systems has received relatively little attention so far: their ultimate fate.Most planet hosts will eventually evolve into white dwarfs, Earth-sized stellar embers, and the outer parts of their planetary systems (in the solar system, Mars and beyond) can survive largely intact for billions of years. While scattered and tidally disrupted planetesimals are directly detected at a small number of white dwarfs in the form infrared excess, the most powerful probe for detecting evolved planetary systems is metal pollution of the otherwise pristine H/He atmospheres.I will present the results of a multi-cycle HST survey that has obtained COS observations of 136 white dwarfs. These ultraviolet spectra are exquisitely sensitive to the presence of metals contaminating the white atmosphere. Our sophisticated model atmosphere analysis demonstrates that at least 27% of all targets are currently accreting planetary debris, and an additional 29% have very likely done so in the past. These numbers suggest that planet formation around A-stars (the dominant progenitors of today's white dwarf population) is similarly efficient as around FGK stars.In addition to post-main sequence planetary system demographics, spectroscopy of the debris-polluted white dwarf atmospheres provides a direct window into the bulk composition of exo-planetesimals, analogous to the way we use of meteorites to determine solar-system abundances. Our ultraviolet spectroscopy is particularly sensitive to the detection of Si, a dominant rock-forming species, and we identify up to ten additional volatile and refractory elements in the most strongly

  11. A Novel Observation-Guided Approach for Evaluating Mesoscale Convective Systems Simulated by the DOE ACME Model

    Science.gov (United States)

    Feng, Z.; Ma, P. L.; Hardin, J. C.; Houze, R.

    2017-12-01

    Mesoscale convective systems (MCSs) are the largest type of convective storms that develop when convection aggregates and induces mesoscale circulation features. Over North America, MCSs contribute over 60% of the total warm-season precipitation and over half of the extreme daily precipitation in the central U.S. Our recent study (Feng et al. 2016) found that the observed increases in springtime total and extreme rainfall in this region are dominated by increased frequency and intensity of long-lived MCSs*. To date, global climate models typically do not run at a resolution high enough to explicitly simulate individual convective elements and may not have adequate process representations for MCSs, resulting in a large deficiency in projecting changes of the frequency of extreme precipitation events in future climate. In this study, we developed a novel observation-guided approach specifically designed to evaluate simulated MCSs in the Department of Energy's climate model, Accelerated Climate Modeling for Energy (ACME). The ACME model has advanced treatments for convection and subgrid variability and for this study is run at 25 km and 100 km grid spacings. We constructed a robust MCS database consisting of over 500 MCSs from 3 warm-season observations by applying a feature-tracking algorithm to 4-km resolution merged geostationary satellite and 3-D NEXRAD radar network data over the Continental US. This high-resolution MCS database is then down-sampled to the 25 and 100 km ACME grids to re-characterize key MCS properties. The feature-tracking algorithm is adapted with the adjusted characteristics to identify MCSs from ACME model simulations. We demonstrate that this new analysis framework is useful for evaluating ACME's warm-season precipitation statistics associated with MCSs, and provides insights into the model process representations related to extreme precipitation events for future improvement. *Feng, Z., L. R. Leung, S. Hagos, R. A. Houze, C. D. Burleyson

  12. Laser fusion system design study. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    The following studies were completed: (1) The synthesis of a pointing/control system compatible with existing and advanced laser opto-mechanical configurations. (2) Attainment of the required pointing angle, longitudinal focus, and differential pathlength accuracies. (3) Maximum modularization of the sensor and gimbal assemblies to provide the required accuracies at minimum cost. Detailed information is given on each. (MOW)

  13. Power system EMP protection. Final report

    International Nuclear Information System (INIS)

    Marable, J.H.; Barnes, P.R.; Nelson, D.B.

    1975-05-01

    Voltage transients induced in electric power lines and control circuits by the electromagnetic pulse (EMP) from high-altitude nuclear detonations may cause widespread power failure and damage in electric power systems. This report contains a parametric study of EMP power line surges and discusses protective measures to minimize their effects. Since EMP surges have considerably greater rates of rise than lightning surges, recommended standards and test procedures are given to assure that surge arresters protect equipment from damage by EMP. Expected disturbances and damage to power systems are reviewed, and actions are presented which distribution companies can take to counter them. These include backup communications methods, stockpiling of vulnerable parts, repair procedures, and dispatcher actions to prevent blackout from EMP-caused instabilities. A long-range program is presented for improving distributors' protection against EMP. This involves employee training, hardware protection for power and control circuits, and improvement of plans for emergency action. (U.S.)

  14. Integrated radwaste treatment system. Final report

    International Nuclear Information System (INIS)

    Baker, M.N.; Houston, H.M.

    1997-10-01

    In May 1988, the West Valley Demonstration Project (WVDP) began pretreating liquid high-level radioactive waste (HLW). This HLW was produced during spent nuclear fuel reprocessing operations that took place at the Western New York Nuclear Service Center from 1966 to 1972. Original reprocessing operations used plutonium/uranium extraction (PUREX) and thorium extraction (THOREX) processes to recover usable isotopes from spent nuclear fuel. The PUREX process produced a nitric acid-based waste stream, which was neutralized by adding sodium hydroxide to it. About two million liters of alkaline liquid HLW produced from PUREX neutralization were stored in an underground carbon steel tank identified as Tank 8D-2. The THOREX process, which was used to reprocess one core of mixed uranium-thorium fuel, resulted in about 31,000 liters of acidic waste. This acidic HLW was stored in an underground stainless steel tank identified as Tank 8D-4. Pretreatment of the HLW was carried out using the Integrated Radwaste Treatment System (IRTS), from May 1988 until May 1995. This system was designed to decontaminate the liquid HLW, remove salts from it, and encapsulate the resulting waste into a cement waste form that achieved US Nuclear Regulatory Commission (NRC) criteria for low-level waste (LLW) storage and disposal. A thorough discussion of IRTS operations, including all systems, subsystems, and components, is presented in US Department of Energy (DOE) Topical Report (DOE/NE/44139-68), Integrated Radwaste Treatment System Lessons Learned from 2 1/2 Years of Operation. This document also presents a detailed discussion of lessons learned during the first 2 1/2 years of IRTS operation. This report provides a general discussion of all phases of IRTS operation, and presents additional lessons learned during seven years of IRTS operation

  15. Final Report of Strongly Interacting Fermion Systems

    International Nuclear Information System (INIS)

    Wilkins, J. W.

    2001-01-01

    There has been significant progress in three broad areas: (A) Optical properties, (B) Large-scale computations, and (C) Many-body systems. In this summary the emphasis is primarily on those papers that point to the research plans. At the same time, some important analytic work is not neglected, some of it even appearing in the description of large-scale Computations. Indeed one of the aims of such computations is to give new insights which lead to development of models capable of simple analytic or nearly analytic analysis

  16. Dual Manifold System for Arraying Biomolecules; FINAL

    International Nuclear Information System (INIS)

    Doktycz, M.J.

    2001-01-01

    The objective of this CRADA is to establish a new approach to fluid transfer and array construction. This new approach will involve a high-speed, multiplexed fluid distribution valve and ink jet valves. It will enable the parallel handling of multiple reagents for a system that will have multiple applications in addition to the high-speed construction of microarrays. The primary tasks involve proof of principle experiments aimed at establishing key components of the technology and evaluating various optional configurations. The basic platform for evaluating the technology will be set-up by the Contractor at Oak Ridge National Laboratory (ORNL) and will employ custom valving prepared by Rheodyne. The test platform will consist of a motion controller, 3-axes of motion, software, and pneumatic control; and will be used to evaluate the hybrid valve

  17. Buried waste containment system materials. Final Report

    International Nuclear Information System (INIS)

    Weidner, J.R.; Shaw, P.G.

    1997-10-01

    This report describes the results of a test program to validate the application of a latex-modified cement formulation for use with the Buried Waste Containment System (BWCS) process during a proof of principle (POP) demonstration. The test program included three objectives. One objective was to validate the barrier material mix formulation to be used with the BWCS equipment. A basic mix formula for initial trials was supplied by the cement and latex vendors. The suitability of the material for BWCS application was verified by laboratory testing at the Idaho National Engineering and Environmental Laboratory (INEEL). A second objective was to determine if the POP BWCS material emplacement process adversely affected the barrier material properties. This objective was met by measuring and comparing properties of material prepared in the INEEL Materials Testing Laboratory (MTL) with identical properties of material produced by the BWCS field tests. These measurements included hydraulic conductivity to determine if the material met the US Environmental Protection Agency (EPA) requirements for barriers used for hazardous waste sites, petrographic analysis to allow an assessment of barrier material separation and segregation during emplacement, and a set of mechanical property tests typical of concrete characterization. The third objective was to measure the hydraulic properties of barrier material containing a stop-start joint to determine if such a feature would meet the EPA requirements for hazardous waste site barriers

  18. Mirror confinement systems: Final technical report

    International Nuclear Information System (INIS)

    1988-08-01

    This report contains: (1) A discussion of azimuthal asymmetrics and fluctuations in RFC-XX-M. Both lead to enhanced radial transport in RFC-XX-M, and presumably most other tandem mirror machines as well; A report on four operating modes of RFC-XX-M which were developed and studied as part of the collaboration. These operating modes were the simple tandem mode, the negative (floating) potential mode, the hot electron mode, and the ECH (electron cyclotron heating) mode; A pulsed rf heated discharge cleaning system which was developed for RFC-XX-M. This method of cleaning proved much more effective than normal glow discharge cleaning, and variations of it are currently in use on the GAMMA-10 tandem mirror and the JIPP TII-U tokamak at the Institute for Plasma Physics at Nagoya; Short descriptions of the diagnostics development and improvement done in conjunction with the work on RFC-XX-M; and a compilation of the work performed at the University of Tsukuba on GAMMA-10. Most of the effort on GAMMA-10 involved diagnostics development and improvement. 16 refs., 42 figs., 1 tab

  19. Condenser inleakage monitoring system development. Final report

    International Nuclear Information System (INIS)

    Kassen, W.R.; Putkey, T.A.; Sawochka, S.G.; Pearl, W.L.; Clouse, M.E.

    1982-09-01

    An instrument/hardware package for air and condenser cooling water inleakage location employing the helium and freon techniques was designed and fabricated. The package consists of design details for tracer gas distribution hardware, injection plenums, and a sample preconditioner and instrument module. Design of the package was based on an evaluation of helium and freon leak detectors and a survey of utility user's experience with the helium and freon techniques. The applicability of the instrument/hardware package to air and cooling water inleakage location was demonstrated at Pacific Gas and Electric Company's Moss Landing Station. The use of calibrated leaks indicated that cooling water leaks down to 1.5 x 10 -4 gpm (0.56 ml/min) and air leaks down to 0.05 cfm were readily detectable with the helium technique, whereas a 4 x 10 -4 gpm (1.5 ml/min) liquid leak was the readily detectable minimum via the freon technique. The field demonstration and in-house detector testing showed the helium technique to be preferable to the freon technique for inleakage location at PWRs, BWRs, and fossil-fueled systems

  20. A study of the relationship between cloud-to-ground lightning and precipitation in the convective weather system in China

    Directory of Open Access Journals (Sweden)

    Y. Zhou

    Full Text Available In this paper, the correlation between cloud-to-ground (CG lightning and precipitation has been studied by making use of the data from weather radar, meteorological soundings, and a lightning location system that includes three direction finders about 40 km apart from each other in the Pingliang area of east Gansu province in P. R. China. We have studied the convective systems that developed during two cold front processes passing over the observation area, and found that the CG lightning can be an important factor in the precipitation estimation. The regression equation between the average precipitation intensity (R and the number of CG lightning flashes (L in the main precipitation period is R = 1.69 ln (L - 0.27, and the correlation coefficient r is 0.86. The CG lightning flash rate can be used as an indicator of the formation and development of the convective weather system. Another more exhaustive precipitation estimation method has been developed by analyzing the temporal and spatial distributions of the precipitation relative to the location of the CG lightning flashes. Precipitation calculated from the CG lightning flashes is very useful, especially in regions with inadequate radar cover.

    Key words. Meteorology and atmospheric dynamics (atmospheric electricity; lightning; precipitation

  1. Transactive Campus Energy Systems: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Katipamula, Srinivas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Corbin, Charles D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Haack, Jereme N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hao, He [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kim, Woohyun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hostick, Donna J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Akyol, Bora A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Allwardt, Craig H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carpenter, Brandon J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Huang, Sen [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Guopeng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lutes, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Makhmalbaf, Atefe [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendon, Vrushali V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ngo, Hung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Somasundaram, Sriram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Underhill, Ronald M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhao, Mingjie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-09-26

    Transactive energy refers to the combination of economic and control techniques to improve grid reliability and efficiency. The fundamental purpose of transactive energy management is to seamlessly coordinate the operation of large numbers of new intelligent assets—such as distributed solar, energy storage and responsive building loads—to provide the flexibility needed to operate the power grid reliably and at minimum cost, particularly one filled with intermittent renewable generation such as the Pacific Northwest. It addresses the key challenge of providing smooth, stable, and predictable “control” of these assets, despite the fact that most are neither owned nor directly controlled by the power grid. The Clean Energy and Transactive Campus (CETC) work described in this report was done as part of a Cooperative Research and Development Agreement (CRADA) between the U.S. Department of Energy’s Pacific Northwest National Laboratory (PNNL) and the Washington State Department of Commerce (Commerce) through the Clean Energy Fund (CEF). The project team consisted of PNNL, the University of Washington (UW) and Washington State University (WSU), to connect the PNNL, UW, and WSU campuses to form a multi-campus testbed for transaction-based energy management—transactive—solutions. Building on the foundational transactive system established by the Pacific Northwest Smart Grid Demonstration (PNWSGD), the purpose of the project was to construct the testbed as both a regional flexibility resource and as a platform for research and development (R&D) on buildings/grid integration and information-based energy efficiency. This report provides a summary of the various tasks performed under the CRADA.

  2. A high-latitude, low-latitude boundary layer model of the convection current system

    International Nuclear Information System (INIS)

    Siscoe, G.L.; Lotko, W.; Sonnerup, B.U.O.

    1991-01-01

    Observations suggest that both the high- and low-latitude boundary layers contribute to magnetospheric convection, and that their contributions are linked. In the interpretation pursued here, the high-latitude boundary layer (HBL) generates the voltage while the low-latitude boundary layer (LBL) generates the current for the part of the convection electric circuit that closes through the ionosphere. This paper gives a model that joins the high- and low-latitude boundary layers consistently with the ionospheric Ohm's law. It describes an electric circuit linking both boundary layers, the region 1 Birkeland currents, and the ionospheric Pedersen closure currents. The model works by using the convection electric field that the ionosphere receives from the HBL to determine two boundary conditions to the equations that govern viscous LBL-ionosphere coupling. The result provides the needed self-consistent coupling between the two boundary layers and fully specifies the solution for the viscous LBL-ionosphere coupling equations. The solution shows that in providing the current required by the ionospheric Ohm's law, the LBL needs only a tenth of the voltage that spans the HBL. The solution also gives the latitude profiles of the ionospheric electric field, parallel currents, and parallel potential. It predicts that the plasma in the inner part of the LBL moves sunward instead of antisunward and that, as the transpolar potential decreases below about 40 kV, reverse polarity (region 0) currents appear at the poleward border of the region 1 currents. A possible problem with the model is its prediction of a thin boundary layer (∼1000 km), whereas thicknesses inferred from satellite data tend to be greater

  3. DECONTAMINATION SYSTEMS AND INFORMATION RESEARCH PROGRAM; FINAL

    International Nuclear Information System (INIS)

    Echol E. Cook, Ph.D., PE.

    1998-01-01

    Tek Centrifugal Membrane System was a unique separation process introduced through the Agreement that is now being used at the Los Alamos National Laboratory. Based on the cost to the USDOE for both technologies and considering their usefulness in cleaning up contaminated sites, no other technologies developed through USDOE provide or have the propensity to provide as great a return on investment and impact on environmental remediation. These technologies alone make the$10.3 million USDOE investment in the WVU Cooperative Agreement a tremendous investment

  4. The completed design of the SLC Final Focus System

    International Nuclear Information System (INIS)

    Murray, J.J.; Brown, K.L.; Fieguth, T.

    1987-02-01

    The design of the SLC Final Focus System has evolved from its initial conceptual design into its final form. This final design is described including a review of the critical decisions influencing the adoption of particular features. The creation of a feasible design has required that these decisions be tempered by practical considerations such as site constraints, correction of optical errors caused by imperfections, and accommodations requested by engineers and particle detector physicists. As this is the first such system to be built, it is hoped that the experience gained will be useful for the design of future systems

  5. Coupled calculation of external heat transfer and material temperatures of convection-cooled turbine blades. Final report; Gekoppelte Berechnung des aeusseren Waermeuebergangs und der Materialtemperaturen konvektionsgekuehlter Turbinenschaufeln. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Heselhaus, A.

    1997-05-01

    In this work a hybrid program system consisting of a 3D finite-volume Navier-Stokes flow solver and a 3D finite-element heat conduction solver has been developed. It enables the coupled calculation of structure temperatures in diabatic solid/fluid configurations. The grids of both the finite element and the finite volume computational domain may be completely independent. The coupled program fully resolves the thermal interaction between heat transfer and the resulting material temperatures. The developed coupling algorithm is numerically stable, conservative and works without the need to define ambient temperatures in the flowfield. This allows for the simulation of any solid/fluid configuration. When simulating combined blade/endwall cooling or filmcooling, only a coupled procedure is capable to completely account for the interaction between all relevant thermal parameters. It is found that the coupled calculation of convective cooling in a realistic guide vane leads locally to 45 K higher and 107 K lower blade temperatures than the uncoupled calculation. This shows that accounting for the thermal interaction between the flow and the structure offers both potential to save cooling air and a lower margin of safety when designing cooling systems close to the thermal limits of the blade material. (orig.) [Deutsch] Im Rahmen der vorliegenden Arbeit wurde ein Verfahren zur Berechnung der Temperaturverteilung in diabat umstroemten Koerpern entwickelt, bei dem ein 3D-Finite Volumen Navier-Stokes Stroemungsloeser und ein 3D-Finite Elemente Waermeleitungsloeser zu einem hybriden Programmsystem gekoppelt werden. Dabei besteht die Moeglichkeit, voellig unabhaengige Rechennetze fuer Stroemung und Struktur zu verwenden. Mit dem gekoppelten Verfahren kann die Wechselwirkung zwischen resultierenden Materialtemperaturen und dem davon rueck-beeinflussten Waermeuebergang beruecksichtigt werden. Weiterhin ist der hier entwickelte, stabile und konservative Kopplungsalgorithmus nicht

  6. Application of rain scanner SANTANU and transportable weather radar in analyze of Mesoscale Convective System (MCS) events over Bandung, West Java

    Science.gov (United States)

    Nugroho, G. A.; Sinatra, T.; Trismidianto; Fathrio, I.

    2018-05-01

    Simultaneous observation of transportable weather radar LAPAN-GMR25SP and rain-scanner SANTANU were conducted in Bandung and vicinity. The objective is to observe and analyse the weather condition in this area during rainy and transition season from March until April 2017. From the observation result reported some heavy rainfall with hail and strong winds occurred on March 17th and April 19th 2017. This events were lasted within 1 to 2 hours damaged some properties and trees in Bandung. Mesoscale convective system (MCS) are assumed to be the cause of this heavy rainfall. From two radar data analysis showed a more local convective activity in around 11.00 until 13.00 LT. This local convective activity are showed from the SANTANU observation supported by the VSECT and CMAX of the Transportable radar data that signify the convective activity within those area. MCS activity were observed one hour after that. This event are confirm by the classification of convective-stratiform echoes from radar data and also from the high convective index from Tbb Himawari 8 satellite data. The different MCS activity from this two case study is that April 19 have much more MCS activity than in March 17, 2017.

  7. Radiative-convective equilibrium model intercomparison project

    Science.gov (United States)

    Wing, Allison A.; Reed, Kevin A.; Satoh, Masaki; Stevens, Bjorn; Bony, Sandrine; Ohno, Tomoki

    2018-03-01

    RCEMIP, an intercomparison of multiple types of models configured in radiative-convective equilibrium (RCE), is proposed. RCE is an idealization of the climate system in which there is a balance between radiative cooling of the atmosphere and heating by convection. The scientific objectives of RCEMIP are three-fold. First, clouds and climate sensitivity will be investigated in the RCE setting. This includes determining how cloud fraction changes with warming and the role of self-aggregation of convection in climate sensitivity. Second, RCEMIP will quantify the dependence of the degree of convective aggregation and tropical circulation regimes on temperature. Finally, by providing a common baseline, RCEMIP will allow the robustness of the RCE state across the spectrum of models to be assessed, which is essential for interpreting the results found regarding clouds, climate sensitivity, and aggregation, and more generally, determining which features of tropical climate a RCE framework is useful for. A novel aspect and major advantage of RCEMIP is the accessibility of the RCE framework to a variety of models, including cloud-resolving models, general circulation models, global cloud-resolving models, single-column models, and large-eddy simulation models.

  8. The effect of the United States Great Lakes on the maintenance of derecho-producing mesoscale convective systems.

    Science.gov (United States)

    Bentley, M.; Sparks, J.; Graham, R.

    2003-04-01

    The primary aim of this research is to investigate the influence of the United States Great Lakes on the intensity of mesoscale convective systems (MCSs). One of the greatest nowcast challenges during the warm season is anticipating the impact of the Great Lakes on severe convection, particularly MCSs capable of producing damaging widespread windstorms known as derechos. Since a major derecho activity corridor lies over the Great Lakes region, it is important to understand the effects of the Lakes on the intensity and propagation of severe wind producing MCSs. Specific objectives of the research include: 1) The development of a short-term climatology of MCS events that have impacted the Great Lakes region over the past seven years; 2) An analysis of radar, satellite, surface (including buoy and lighthouse observations), and lake surface temperature data to determine the environmental conditions impacting the evolution of MCSs passing over a Great Lake; 3) An examination of MCS initiation times and seasonal frequencies of occurrence to delineate temporal consistencies in MCS evolution due to changing lake surface temperatures; and 4) The development of conceptual and forecast models to help anticipate MCS intensity and morphology as these systems interact with the Great Lakes environment.

  9. Basal melting driven by turbulent thermal convection

    Science.gov (United States)

    Rabbanipour Esfahani, Babak; Hirata, Silvia C.; Berti, Stefano; Calzavarini, Enrico

    2018-05-01

    Melting and, conversely, solidification processes in the presence of convection are key to many geophysical problems. An essential question related to these phenomena concerns the estimation of the (time-evolving) melting rate, which is tightly connected to the turbulent convective dynamics in the bulk of the melt fluid and the heat transfer at the liquid-solid interface. In this work, we consider a convective-melting model, constructed as a generalization of the Rayleigh-Bénard system, accounting for the basal melting of a solid. As the change of phase proceeds, a fluid layer grows at the heated bottom of the system and eventually reaches a turbulent convection state. By means of extensive lattice-Boltzmann numerical simulations employing an enthalpy formulation of the governing equations, we explore the model dynamics in two- and three-dimensional configurations. The focus of the analysis is on the scaling of global quantities like the heat flux and the kinetic energy with the Rayleigh number, as well as on the interface morphology and the effects of space dimensionality. Independently of dimensionality, we find that the convective-melting system behavior shares strong resemblances with that of the Rayleigh-Bénard one, and that the heat flux is only weakly enhanced with respect to that case. Such similarities are understood, at least to some extent, considering the resulting slow motion of the melting front (with respect to the turbulent fluid velocity fluctuations) and its generally little roughness (compared to the height of the fluid layer). Varying the Stefan number, accounting for the thermodynamical properties of the material, also seems to have only a mild effect, which implies the possibility of extrapolating results in numerically delicate low-Stefan setups from more convenient high-Stefan ones. Finally, we discuss the implications of our findings for the geophysically relevant problem of modeling Arctic ice melt ponds.

  10. Thermal modeling of the forced convection Sandwich Greenhouse drying system for rubber sheets

    International Nuclear Information System (INIS)

    Tanwanichkul, B.; Thepa, S.; Rordprapat, W.

    2013-01-01

    Highlights: • Sandwich Greenhouse is designed for better quality and efficiency of rubber sheet drying. • Thermal models are developed to predict the convection heat transfer coefficient. • The models are validated and show good agreement with the actual experimental data. • The proposed greenhouse can maintain 40–60 °C, suitable for rubber sheet drying. • This greenhouse can bring down the moisture content to 2.8% in fewer than 2 days. - Abstract: In this paper, a novel “Sandwich Greenhouse” for rubber sheet drying is proposed. Using solar energy as the only heat source instead of traditional smoke house that requires firewood, it eliminates shortcomings such as skilled labor monitoring requirement, possible fire hazard, and darken-color rubber sheets due to soot particle contamination. Our greenhouse is specially designed to retain solar energy within, while minimizing the heat loss to the outside environment. The mathematical models are developed to predict the convection mass transfer coefficient and to study the thermal behavior during the drying of rubber sheets under our proposed greenhouse design. Validated with experimental observations, the models show good agreement with the actual experimental data. The experiment demonstrates an effectiveness of our proposed Sandwich Greenhouse, as the temperature of the rubber sheet is 15 °C and 5 °C higher than the ambient temperature during the daytime and nighttime, respectively. As a result, the moisture content of the rubber sheets can decrease from 36.4% to 2.8% in fewer than 2 days

  11. General method for final focus system design for circular colliders

    Directory of Open Access Journals (Sweden)

    Riccardo de Maria

    2008-03-01

    Full Text Available Colliders use final focus systems to reduce the transverse beam sizes at the interaction point in order to increase collision event rates. The maximum focal strength (gradient of the quadrupoles, and the maximum beam size in them, together limit the beam size reduction that is possible. The goal of a final focus system design is to find the best compromise between quadrupole aperture and quadrupole gradient, for the magnet technology that is used. This paper develops a design method that identifies the intrinsic limitations of a final focus system, validates the results of the method against realistic designs, and reports its application to the upgrade of the Large Hadron Collider final focus.

  12. Mathematical modeling of flow in the working part of an acousto-convective drying system

    Science.gov (United States)

    Kravchenko, A. S.; Zhilin, A. A.; Fedorova, N. N.

    2018-03-01

    The objective of this study was to numerically simulate the nonstationary processes occurring in the acoustic-convective dryer (ACD) channel. In the present work, the problem was solved numerically in a three-dimensional formulation taking into account all features of the ACD duct in real geometry. The processes occurring in the ACD duct were simulated using the ANSYS Fluent 18.0 software. The numerical experiments provided an aggregate picture of the working gas flow in the ACD duct with the features near the subsonic nozzle and the cavity. The results of the numerical calculations were compared with experimental data. The best agreement with the experimental data was obtained for the viscosity model neglecting turbulent effects.

  13. Variability of oceanic deep convective system vertical structures observed by CloudSat in Indo-Pacific regions associated with the Madden-Julian oscillation

    Science.gov (United States)

    Yuan, Jian

    2016-09-01

    Vertical structures of deep convective systems during the Madden-Julian oscillation (MJO) are investigated using CloudSat radar measurements in Indo-Pacific oceanic areas. In active phases of the MJO, relatively more large systems and connected mesoscale convective systems (CMCSs) occur. The occurrence frequency of CMCSs peaks in the onset phase, a phase earlier than separated mesoscale convective systems (SMCSs). Compared with SMCSs, CMCSs of all sizes have weaker reflectivity above 8 km in their deep precipitating portions and thick anvil clouds closely linked to them, suggesting more "stratiform" physics associated with them. SMCSs and CMCSs together produce relatively the least anvil clouds in the onset phase, while their deep precipitating portions show stronger/weaker reflectivity above 8 km before/after the onset phase. Thus, after the onset phase of the MJO, mesoscale convective systems shift toward a more "convective" organization because SMCSs maximize after the onset, while their internal structures appear more stratiform because internally they have weaker reflectivity above 8 km. CMCSs coincide with a more humid middle troposphere spatially, even at the same locations a few days before they occur. Middle-tropospheric moistening peaks in the onset phase. Moistening of the free troposphere around deep convective systems shows relatively stronger moistening/drying below 700 hPa before/after the onset phase than domain-mean averages. Low-topped clouds occur most frequently around CMCSs and in active phases, consistent with the presence of a moister free troposphere. Coexistence of these phenomena suggests that the role of middle troposphere moisture in the formation of CMCSs should be better understood.

  14. State and parameter estimation of spatiotemporally chaotic systems illustrated by an application to Rayleigh-Bénard convection.

    Science.gov (United States)

    Cornick, Matthew; Hunt, Brian; Ott, Edward; Kurtuldu, Huseyin; Schatz, Michael F

    2009-03-01

    Data assimilation refers to the process of estimating a system's state from a time series of measurements (which may be noisy or incomplete) in conjunction with a model for the system's time evolution. Here we demonstrate the applicability of a recently developed data assimilation method, the local ensemble transform Kalman filter, to nonlinear, high-dimensional, spatiotemporally chaotic flows in Rayleigh-Bénard convection experiments. Using this technique we are able to extract the full temperature and velocity fields from a time series of shadowgraph measurements. In addition, we describe extensions of the algorithm for estimating model parameters. Our results suggest the potential usefulness of our data assimilation technique to a broad class of experimental situations exhibiting spatiotemporal chaos.

  15. Continuous Data Assimilation for a 2D Bénard Convection System Through Horizontal Velocity Measurements Alone

    Science.gov (United States)

    Farhat, Aseel; Lunasin, Evelyn; Titi, Edriss S.

    2017-06-01

    In this paper we propose a continuous data assimilation (downscaling) algorithm for a two-dimensional Bénard convection problem. Specifically we consider the two-dimensional Boussinesq system of a layer of incompressible fluid between two solid horizontal walls, with no-normal flow and stress-free boundary conditions on the walls, and the fluid is heated from the bottom and cooled from the top. In this algorithm, we incorporate the observables as a feedback (nudging) term in the evolution equation of the horizontal velocity. We show that under an appropriate choice of the nudging parameter and the size of the spatial coarse mesh observables, and under the assumption that the observed data are error free, the solution of the proposed algorithm converges at an exponential rate, asymptotically in time, to the unique exact unknown reference solution of the original system, associated with the observed data on the horizontal component of the velocity.

  16. Statistical validation of the model of diffusion-convection (MDC) of 137Cs for the assessment of recent sedimentation rates in coastal systems

    International Nuclear Information System (INIS)

    Paulo Alves de Lima Ferreira; Eduardo Siegle; Michel Michaelovitch de Mahiques; Rubens Cesar Lopes Figueira; Carlos Augusto Franca Schettini

    2015-01-01

    This study aimed the validation of the model of diffusion-convection (MDC) of 137 Cs for the calculation of recent sedimentation rates in 13 sedimentary cores of two Brazilian coastal systems, the Cananeia-Iguape and Santos-Sao Vicente estuarine systems. The MDC covers key factors responsible for 137 Cs vertical migration in sediments: its diffusion to the interstitial water and the vertical convection of this water through the sediments. This study successfully validated the MDC use to determine sedimentation rates, which was statistically validated not only with 210 Pb xs (unsupported 210 Pb) models, widely used in oceanographic studies, but also by literature values for those regions. (author)

  17. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Held, Isaac [Princeton Univ., NJ (United States); Balaji, V. [Princeton Univ., NJ (United States); Fueglistaler, Stephan [Princeton Univ., NJ (United States)

    2016-09-19

    We have constructed and analyzed a series of idealized models of tropical convection interacting with large-scale circulations, with 25-50km resolution and with 1-2km cloud resolving resolution to set the stage for rigorous tests of convection closure schemes in high resolution global climate models. Much of the focus has been on the climatology of tropical cyclogenesis in rotating systems and the related problem of the spontaneous aggregation of convection in non-rotating systems. The PI (Held) will be delivering the honorary Bjerknes lecture at the Fall 2016 AGU meeting in December on this work. We have also provided new analyses of long-standing issues related to the interaction between convection and the large-scale circulation: Kelvin waves in the upper troposphere and lower stratosphere, water vapor transport into the stratosphere, and upper tropospheric temperature trends. The results of these analyses help to improve our understanding of processes, and provide tests for future high resolution global modeling. Our final goal of testing new convections schemes in next-generation global atmospheric models at GFDL has been left for future work due to the complexity of the idealized model results meant as tests for these models uncovered in this work and to computational resource limitations. 11 papers have been published with support from this grant, 2 are in review, and another major summary paper is in preparation.

  18. FOCUS: a fire management planning system -- final report

    Science.gov (United States)

    Frederick W. Bratten; James B. Davis; George T. Flatman; Jerold W. Keith; Stanley R. Rapp; Theodore G. Storey

    1981-01-01

    FOCUS (Fire Operational Characteristics Using Simulation) is a computer simulation model for evaluating alternative fire management plans. This final report provides a broad overview of the FOCUS system, describes two major modules-fire suppression and cost, explains the role in the system of gaming large fires, and outlines the support programs and ways of...

  19. Model validation studies of solar systems, Phase III. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lantz, L.J.; Winn, C.B.

    1978-12-01

    Results obtained from a validation study of the TRNSYS, SIMSHAC, and SOLCOST solar system simulation and design are presented. Also included are comparisons between the FCHART and SOLCOST solar system design programs and some changes that were made to the SOLCOST program. Finally, results obtained from the analysis of several solar radiation models are presented. Separate abstracts were prepared for ten papers.

  20. Study of the heat transfers spectral radiation - conduction - natural convection in hybrid photovoltaic systems for buildings

    International Nuclear Information System (INIS)

    Muresan, C.

    2005-01-01

    numerical solution of the Radiative Transfer Equation in diffused part in the case of a mono-dimensional plane geometry. The directional discretizations of each layer are selected in such a way that the discrete directions of one of the layers correspond to those refracted of the close layer and this makes it possible to avoid the use of approximations related to non coincidence of the discrete directions of a layer with those refracted by the close layer. Directional quadratures are then established in an adaptive way in each layer and for each spectral frequency. The results obtained are validated by an approach of Monte Carlo type. The coupling of this model with a Low Reynolds number RANS model will be carried out. This will be done in order to study the convective heat transfers in natural convection for configurations of double facade integration under consideration within the framework of PRI CNRS. The comparison of this model is carried out for experimental configurations of vertical channel type uniformly heated in natural convection. The prospects for this stage are multiple and consist of analyzing the influence of the mode of flow on the thermal pulling of the hybrid components, the effects of the positioning of modules statement, the air gap between the two frontages and the boundary conditions thermal generated by the modules. Lastly, in order to supplement the energy balance of such components and more particularly that governs the thermal behavior of a photosensitive cell, the electric phenomenon of conversion is approached in adequacy with the level of modeling of the coupled thermal transfers radiation - conduction within a PV component. To carry this out, we can consider the local power of spectral radiation absorbed and converted into electric output. (author)

  1. National Convective Weather Diagnostic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current convective hazards identified by the National Convective Weather Detection algorithm. The National Convective Weather Diagnostic (NCWD) is an automatically...

  2. FINAL IMPLEMENTATION AND PERFORMANCE OF THE LHC COLLIMATOR CONTROL SYSTEM

    CERN Document Server

    Redaelli, S; Masi, A; Losito, R

    2009-01-01

    The 2008 collimation system of the CERN Large Hadron Collider (LHC) included 80 movable collimators for a total of 316 degrees of freedom. Before beam operation, the final controls implementation was deployed and commissioned. The control system enabled remote control and appropriate diagnostics of the relevant parameters. The collimator motion is driven with time-functions, synchronized with other accelerator systems, which allows controlling the collimator jaw positions with a micrometer accuracy during all machine phases. The machine protection functionality of the system, which also relies on function-based tolerance windows, was also fully validated. The collimator control challenges are reviewed and the final system architecture is presented. The results of the remote system commissioning and the overall performance are discussed.

  3. Momentum, heat, and neutral mass transport in convective atmospheric pressure plasma-liquid systems and implications for aqueous targets

    Science.gov (United States)

    Lindsay, Alexander; Anderson, Carly; Slikboer, Elmar; Shannon, Steven; Graves, David

    2015-10-01

    There is a growing interest in the study of plasma-liquid interactions with application to biomedicine, chemical disinfection, agriculture, and other fields. This work models the momentum, heat, and neutral species mass transfer between gas and aqueous phases in the context of a streamer discharge; the qualitative conclusions are generally applicable to plasma-liquid systems. The problem domain is discretized using the finite element method. The most interesting and relevant model result for application purposes is the steep gradients in reactive species at the interface. At the center of where the reactive gas stream impinges on the water surface, the aqueous concentrations of OH and ONOOH decrease by roughly 9 and 4 orders of magnitude respectively within 50 μ m of the interface. Recognizing the limited penetration of reactive plasma species into the aqueous phase is critical to discussions about the therapeutic mechanisms for direct plasma treatment of biological solutions. Other interesting results from this study include the presence of a 10 K temperature drop in the gas boundary layer adjacent to the interface that arises from convective cooling. Though the temperature magnitudes may vary among atmospheric discharge types (different amounts of plasma-gas heating), this relative difference between gas and liquid bulk temperatures is expected to be present for any system in which convection is significant. Accounting for the resulting difference between gas and liquid bulk temperatures has a significant impact on reaction kinetics; factor of two changes in terminal aqueous species concentrations like H2O2, NO2- , and NO3- are observed in this study if the effect of evaporative cooling is not included.

  4. A forced convective heat transfer model for two-phase hydrogen systems

    International Nuclear Information System (INIS)

    Pasch, J.; Anghaie, S.

    2007-01-01

    A consistent event in the use of hydrogen in nuclear thermal propulsion is film boiling, in which the wall heat is so large that liquid can not exist at the wall. Instead, vapor interfaces with the wall and liquid flows in the core of the duct. To better understand heat transfer under these conditions, a select set of hydrogen test data from these conditions are analyzed. This paper presents the results of an extensive literature search for film boiling heat transfer models. A representative cross-section of these models is then applied to the data. The heat transfer coefficient data were found difficult to predict and highly dependent upon the flow regime. Pre-critical heat flux correlations completely fail to predict the heat transfer of inverted film boiling conditions. Pool boiling models for inverted film boiling also are inappropriate. Current force convection models for inverted film boiling, while far better than the previous two classes of models, still generate large predictive errors. It is recommended that for the inverted annular film boiling flow regime the modified equilibrium bulk Dittus-Boelter model be used. For agitated inverted annular film boiling and dispersed film boiling regimes associated with positive equilibrium qualities, the Hendricks model should be used. (A.C.)

  5. Experiments Using a Ground-Based Electrostatic Levitator and Numerical Modeling of Melt Convection for the Iron-Cobalt System in Support of Space Experiments

    Science.gov (United States)

    Lee, Jonghyun; SanSoucie, Michael P.

    2017-08-01

    Materials research is being conducted using an electromagnetic levitator installed in the International Space Station. Various metallic alloys were tested to elucidate unknown links among the structures, processes, and properties. To accomplish the mission of these space experiments, several ground-based activities have been carried out. This article presents some of our ground-based supporting experiments and numerical modeling efforts. Mass evaporation of Fe50Co50, one of flight compositions, was predicted numerically and validated by the tests using an electrostatic levitator (ESL). The density of various compositions within the Fe-Co system was measured with ESL. These results are being served as reference data for the space experiments. The convection inside a electromagnetically-levitated droplet was also modeled to predict the flow status, shear rate, and convection velocity under various process parameters, which is essential information for designing and analyzing the space experiments of some flight compositions influenced by convection.

  6. Selected geothermal resources data: hydrothermal convection systems in the states of Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Renner, J.L.

    1976-02-01

    Data collected as part of the U.S. Geological Survey's research and land classification programs, from professional publications, and industry sources has been compiled in computer format. Location, surface manifestations, chemistry, physical properties, exploratory and development work, and references pertinent to 290 hydrothermal convection systems comprise the data base.

  7. The Dependence of Convective Core Overshooting on Stellar Mass: Additional Binary Systems and Improved Calibration

    Science.gov (United States)

    Claret, Antonio; Torres, Guillermo

    2018-06-01

    Many current stellar evolution models assume some dependence of the strength of convective core overshooting on mass for stars more massive than 1.1–1.2 M ⊙, but the adopted shapes for that relation have remained somewhat arbitrary for lack of strong observational constraints. In previous work, we compared stellar evolution models to well-measured eclipsing binaries to show that, when overshooting is implemented as a diffusive process, the fitted free parameter f ov rises sharply up to about 2 M ⊙, and remains largely constant thereafter. Here, we analyze a new sample of eight binaries selected to be in the critical mass range below 2 M ⊙ where f ov is changing the most, nearly doubling the number of individual stars in this regime. This interval is important because the precise way in which f ov changes determines the shape of isochrones in the turnoff region of ∼1–5 Gyr clusters, and can thus affect their inferred ages. It also has a significant influence on estimates of stellar properties for exoplanet hosts, on stellar population synthesis, and on the detailed modeling of interior stellar structures, including the calculation of oscillation frequencies that are observable with asteroseismic techniques. We find that the derived f ov values for our new sample are consistent with the trend defined by our earlier determinations, and strengthen the relation. This provides an opportunity for future series of models to test the new prescription, grounded on observations, against independent observations that may constrain overshooting in a different way.

  8. Plant systems/components modularization study. Final report. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-01

    The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort.

  9. ASBESTOS PIPE-INSULATION REMOVAL ROBOT SYSTEM; FINAL

    International Nuclear Information System (INIS)

    Unknown

    2000-01-01

    This final topical report details the development, experimentation and field-testing activities for a robotic asbestos pipe-insulation removal robot system developed for use within the DOE's weapon complex as part of their ER and WM program, as well as in industrial abatement. The engineering development, regulatory compliance, cost-benefit and field-trial experiences gathered through this program are summarized

  10. Plant systems/components modularization study. Final report

    International Nuclear Information System (INIS)

    1977-07-01

    The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort

  11. Concepts of magnetospheric convection

    International Nuclear Information System (INIS)

    Vasyliunas, V.M.

    1975-01-01

    Magnetospheric physics, which grew out of attempts to understand the space environment of the Earth, is becoming increasingly applicable to other systems in the Universe. Among the planets, in addition to the Earth, Jupiter, Mercury, Mars and (in a somewhat different way) Venus are now known to have magnetospheres. The magnetospheres of pulsars have been regarded as an essential part of the pulsar phenomenon. Other astrophysical systems, such as supernova remnant shells or magnetic stars and binary star systems, may be describable as magnetospheres. The major concepts of magnetospheric physics thus need to be formulated in a general way not restricted to the geophysical context in which they may have originated. Magnetospheric convection has been one of the most important and fruitful concepts in the study of the Earth's magnetosphere. This paper describes the basic theoretical notions of convection in a manner applicable to magnetospheres generally and discusses the relative importance of convective corotational motions, with particular reference to the comparison of the Earth and Jupiter. (Auth.)

  12. 2D and 3D thermal simulations for storage systems with internal natural convection for canistered spent fuel

    International Nuclear Information System (INIS)

    Yaksh, M.; Wang, C.

    2004-01-01

    In the US, the number of nuclear plants expected to implement on-site dry storage is increasing each year. As reactors burn advanced fuel assemblies to higher burnups, the dry storage systems will be required to accommodate higher heat loads. This is due to the increasing capacity of the systems and the need to store higher burnup fuel with reasonable cooling periods (i.e., five to six years). As the storage systems heat rejection design must be passive, natural convection is an efficient means for rejection of heat from the spent fuel to the surface of the canister boundary. The design presented in this paper is a canistered system that employs conduction, radiation and convection to reject heat from the canister, which is stored in a vertical concrete cask. The canister containing the spent fuel in this design is a right circular stainless steel vessel capable of storing 37 PWR fuel assemblies with a total canister heat load of 40 kW. Accompanying any design effort is the use of a numerical methodology that can accurately predict the peak-clad temperatures of the fuel and the structural components of the system. The main challenge to any analysis employing internal natural convection may be perceived as a practical limitation due to the size of the model. Since canisters are typically cylindrical, a two-dimensional model can be used to represent the canister. The fuel basket structure, which maintains the configuration of the spent fuel, is an array of square tubes, and is non-axisymmetric. Flow up through the fuel region in the basket encounters a complex cross section due to the fuel assembly rod array (up to 17 x 17). The flow region of the heated gas down the outside of the basket in the annulus between the canister shell and the basket assembly (downcomer) is also an irregular shaped area. To confirm that a two-dimensional (2D) modelling methodology is appropriate, a benchmark using results from a thermal test is required. The thermal test focuses on the

  13. A conceptual design of Final Focus Systems for linear colliders

    International Nuclear Information System (INIS)

    Brown, K.L.

    1987-06-01

    Linear colliders are a relatively recent development in the evolution of particle accelerators. This report discusses some of the approaches that have been considered for the design of Final Focus Systems to demagnify the beam exiting from a linac to the small size suitable for collisions at the interaction point. The system receiving the most attention is the one adopted for the SLAC Linear Collider. However, the theory and optical techniques discussed should be applicable to the design efforts for future machines

  14. Beam dynamics in the SLC final focus system

    International Nuclear Information System (INIS)

    Bambade, P.S.

    1987-06-01

    The SLC luminosity is reached by colliding beams focused to about 2 μm transverse sizes. The Final Focus System (FFS) must enable, beyond its basic optical design, the detection and correction of errors accumulated in the system. In this paper, after summarizing the design, we review the sensitivity to such errors and the ability to correct them. The overall tuning strategy involves three phases: single beam spot minimization, steering the beams in collision and luminosity optimization with beam-beam effects

  15. The Final Focus Test Beam laser referene system

    International Nuclear Information System (INIS)

    Bressler, V.E.; Ruland, R.E.

    1993-05-01

    The original design for the SLAC linac included an alignment reference system with 270 diffraction gratings situated along the 3000 meter linac. These gratings have provided SLAC with a global reference line repeatable to within 200 micro meters. For the Final Focus Test Beam, this laser system has been extended and 13 new diffraction gratings have been installed. Improvements targets and the availability of new instruments allows us to evaluate the performance of the laser reference system at the 510 micro meter level. An explanation of the system and the results of our evaluation are presented

  16. A RECIPE FOR LINEAR COLLIDER FINAL FOCUS SYSTEM DESIGN

    International Nuclear Information System (INIS)

    Seryi, Andrei

    2003-01-01

    The design of Final Focus systems for linear colliders is challenging because of the large demagnifications needed to produce nanometer-sized beams at the interaction point. Simple first- and second-order matrix matching have proven insufficient for this task, and minimization of third- and higher-order aberrations is essential. An appropriate strategy is required for the latter to be successful. A recipe for Final Focus design, and a set of computational tools used to implement this approach, are described herein. An example of the use of this procedure is given

  17. Probing LINEAR Collider Final Focus Systems in SuperKEKB

    CERN Document Server

    Thrane, Paul Conrad Vaagen

    2017-01-01

    A challenge for future linear collider final focus systems is the large chromaticity produced by the final quadrupoles. SuperKEKB will be correcting high levels of chromaticity using the traditional scheme which has been also proposed for the CLIC FFS. We present early simulation results indicating that lowering β*у in the SuperKEKB Low Energy Ring might be possible given on-axis injection and low bunch current, opening the possibility of testing chromaticity correction beyond FFTB level, similar to ILC and approaching that of CLIC. CLIC – Note – 1077

  18. Statistical Characteristics of Mesoscale Convective Systems over the Middle Reaches area of the Yellow River During 2005-2014

    Science.gov (United States)

    Zhao, Guixiang

    2017-04-01

    Based on the hourly TBB and cloud images of FY-2E, meteorological observation data, and NCEP reanalysis data with 1°×1° spatial resolution from May to October during 2005-2014, the climatic characteristics of mesoscale convective systems (MCS) over the middle reaches area of the Yellow River were analyzed, including mesoscale convective complex (MCC), persistent elongated convective systems (PECS), meso-βscale MCC (MβCCS) and Meso-βscale PECS (MβECS). The results are as follows: (1) MCS tended to occur over the middle and south of Gansu, the middle and south of Shanxi, the middle and north of Shaanxi, and the border of Shanxi, Shaanxi and Inner Mongolia. MCS over the middle reaches area of the Yellow River formed in May to October, and was easy to develop the mature in summer. MCC and MβECS were main MCS causing precipitation in summer. (2) The daily variation of MCS was obvious, and usually formed and matured in the afternoon and the evening to early morning of the next day. Most MCS generated fast and dissipated slowly, and were mainly move to the easterly and southeasterly, but the moving of round shape MCS was less than the elongated shape's. (3) The average TBB for the round shape MCS was lower than the elongated shape MCS. The development of MCC was most vigorous and strong, and it was the strongest in August, while that of MβECS wasn't obviously influenced by the seasonal change. The average eccentricity of the mature MCC and PECS over the middle reaches area of the Yellow River was greater than that in USA, and the former was greater than in the lower reaches area of the Yellow River, while the latter was smaller. (4) The characteristics of rainfall caused by MCS were complex over the middle reaches area of the Yellow River, and there were obvious regional difference. There was wider, stronger and longer precipitation when the multiple MCS merged. The rainfall in the center of cloud area was obviously greater than in other region of cloud area. The

  19. Plutonium Protection System (PPS). Volume 2. Hardware description. Final report

    International Nuclear Information System (INIS)

    Miyoshi, D.S.

    1979-05-01

    The Plutonium Protection System (PPS) is an integrated safeguards system developed by Sandia Laboratories for the Department of Energy, Office of Safeguards and Security. The system is designed to demonstrate and test concepts for the improved safeguarding of plutonium. Volume 2 of the PPS final report describes the hardware elements of the system. The major areas containing hardware elements are the vault, where plutonium is stored, the packaging room, where plutonium is packaged into Container Modules, the Security Operations Center, which controls movement of personnel, the Material Accountability Center, which maintains the system data base, and the Material Operations Center, which monitors the operating procedures in the system. References are made to documents in which details of the hardware items can be found

  20. Simulated coal gas MCFC power plant system verification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-30

    The objective of the main project is to identify the current developmental status of MCFC systems and address those technical issues that need to be resolved to move the technology from its current status to the demonstration stage in the shortest possible time. The specific objectives are separated into five major tasks as follows: Stack research; Power plant development; Test facilities development; Manufacturing facilities development; and Commercialization. This Final Report discusses the M-C power Corporation effort which is part of a general program for the development of commercial MCFC systems. This final report covers the entire subject of the Unocal 250-cell stack. Certain project activities have been funded by organizations other than DOE and are included in this report to provide a comprehensive overview of the work accomplished.

  1. Nonlinear convective flows in a two-layer system under the action of spatial temperature modulation of heat release/consumption at the interface

    Science.gov (United States)

    Simanovskii, Ilya B.; Viviani, Antonio; Dubois, Frank

    2018-06-01

    An influence of a spatial temperature modulation of the interfacial heat release/consumption on nonlinear convective flows in the 47v2 silicone oil - water system, is studied. Rigid heat-insulated lateral walls, corresponding to the case of closed cavities, have been considered. Transitions between the flows with different spatial structures, have been investigated. It is shown that the spatial modulation can change the sequence of bifurcations and lead to the appearance of specific steady and oscillatory flows in the system.

  2. Constant system for by-channel thermal-hydraulic calculation of fuel assembly operational conditions in reactors with natural and mixed convection

    International Nuclear Information System (INIS)

    Bogatyrev, I.L.; Bogoslovskaya, G.P.; Zhukov, A.V.; Sorokin, A.P.; Titov, P.A.

    1992-01-01

    System of constants for mass, impulse and energy conservation equations (drag, mixing, heat transfer coefficients, azimuthal unquality of temperature) is reported in region with small Re number for wide range of geometrical assembly parameters. This system can be used in subchannel calculations of assemblies with natural and mixed convection under conditions with loss of flow accident. The formulae are compared with experimental data. 30 refs.; 12 figs.; 1 tab

  3. Columbia River system operation review. Final environmental impact statement

    International Nuclear Information System (INIS)

    1995-11-01

    This Appendix C of the Final Environmental Impact Statement for the Columbia River System discusses impacts on andromous fish and juvenile fish transportation. The principal andromous fish in the Columbia basin include salmonid species (Chinook, coho, and sockeye salmon, and steelhead) and nonsalmoinid andromous species (sturgeon, lamprey, and shad). Major sections in this document include the following: background, scope and process; affected environment for salmon and steelhead, shaded, lamprey, sturgeon; study methods; description of alternatives: qualitative and quantitative findings

  4. A Dynamic Alignment System for the Final Focus Test Beam

    International Nuclear Information System (INIS)

    Ruland, R.E.; Bressler, V.E.; Fischer, G.; Plouffe, D.; SLAC

    2005-01-01

    The Final Focus Test Beam (FFTB) was conceived as a technological stepping stone on the way to the next linear collider. Nowhere is this more evident than with the alignment subsystems. Alignment tolerances for components prior to beam turn are almost an order of magnitude smaller than for previous projects at SLAC. Position monitoring systems which operate independent of the beam are employed to monitor motions of the components locally and globally with unprecedented precision. An overview of the FFTB alignment system is presented herein

  5. The implications of dust ice nuclei effect on cloud top temperature in a complex mesoscale convective system.

    Science.gov (United States)

    Li, Rui; Dong, Xue; Guo, Jingchao; Fu, Yunfei; Zhao, Chun; Wang, Yu; Min, Qilong

    2017-10-23

    Mineral dust is the most important natural source of atmospheric ice nuclei (IN) which may significantly mediate the properties of ice cloud through heterogeneous nucleation and lead to crucial impacts on hydrological and energy cycle. The potential dust IN effect on cloud top temperature (CTT) in a well-developed mesoscale convective system (MCS) was studied using both satellite observations and cloud resolving model (CRM) simulations. We combined satellite observations from passive spectrometer, active cloud radar, lidar, and wind field simulations from CRM to identify the place where ice cloud mixed with dust particles. For given ice water path, the CTT of dust-mixed cloud is warmer than that in relatively pristine cloud. The probability distribution function (PDF) of CTT for dust-mixed clouds shifted to the warmer end and showed two peaks at about -45 °C and -25 °C. The PDF for relatively pristine cloud only show one peak at -55 °C. Cloud simulations with different microphysical schemes agreed well with each other and showed better agreement with satellite observations in pristine clouds, but they showed large discrepancies in dust-mixed clouds. Some microphysical schemes failed to predict the warm peak of CTT related to heterogeneous ice formation.

  6. Tracking the MJO Convection and its Impact on the Diurnal Cycle over the Maritime Continent Using Satellite Observations

    Science.gov (United States)

    Kerns, B. W.; Chen, S. S.

    2017-12-01

    The Indo-Pacific Maritime Continent (MC) is the most active convection center in the tropics, and the most important modes of variability are the diurnal cycle and the Madden-Julian Oscillation (MJO). Previous studies have shown that the MC has strong diurnal variability compared with the rest of the tropics, and the diurnal cycle of convection over the MC is amplified during the passage of an MJO. One outstanding science question is how the passage of the active MJO affects the diurnal cycle. The atmospheric, upper ocean, and land surface forcing factors contributing to the diurnal cycle need to be clarified. In order to address this, large scale precipitation tracking (LPT) is used to identify MJO active and suppressed periods for 2000-2015. To document the diurnal cycle of convection during the active and suppressed periods, TRMM/GPM and mesoscale cloud cluster tracking are used. Finally, the LPT tracking is used to composite the satellite-estimated surface wind, humidity, temperature, cloud cover, and soil moisture over the islands for active versus suppressed MJO periods. In active MJO periods, the diurnal convection in the surrounding marginal seas is enhanced and the diurnal convection over land is decreased. The islands of the MC have greater soil moisture, more cloud cover, and do not warm up as much during the day, leading to a weaker afternoon maximum over land. But how is nocturnal convection over the sea increased? The largest, most mature convective cloud systems are found over the marginal seas in the early morning. This is hypothesized to mainly be a consequence of the longer life cycle of convective systems in the favorable large-scale active MJO. The propagation of the MJO across the MC is facilitated by the enhanced nocturnal deep convection over the sea. In contrast, In the suppressed period the convection is mostly daytime forced convection over land which is locked to the terrain.

  7. Thermal Comfort in Simulated Office Environment with Four Convective and Radiant Cooling Systems

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Mustakallio, Panu; Kolencíková, Sona

    2013-01-01

    with overhead mixing ventilation (MVRC). Whole body thermal sensation (TS) and whole body TS acceptability under the four systems in a simulated office room for one hour exposure were collected. The simulated two-man office (4.12 x 4.20 x 2.89 m, L x W x H) was kept at 26 oC room air temperature. Moderate heat...... to “neutral” compared to male, whose votes were closer to the “slightly warm” thermal sensation. The whole body TS acceptability was rated close to ''clearly acceptable'' (EN 15251-2007) and was independent of subject's gender for all tested systems....

  8. Thermal Conditions in a Simulated Office Environment with Convective and Radiant Cooling Systems

    DEFF Research Database (Denmark)

    Mustakallio, Panu; Bolashikov, Zhecho Dimitrov; Kostov, Kalin

    2013-01-01

    velocity and turbulent intensity were measured and draft rate levels calculated in the room. Manikin-based equivalent temperature (MBET) was determined by two thermal manikins to identify the impact of the local thermal conditions generated by the studied systems on occupants’ thermal comfort. The results......The thermal conditions in a two person office room were measured with four air conditioning systems: chilled beam (CB), chilled beam with radiant panel (CBR), chilled ceiling with ceiling installed mixing ventilation (CCMV) and four desk partition mounted local radiant cooling panels with mixing...

  9. A Climatology of Derecho-Producing Mesoscale Convective Systems in the Central and Eastern United States, 1986-95. Part I: Temporal and Spatial Distribution.

    Science.gov (United States)

    Bentley, Mace L.; Mote, Thomas L.

    1998-11-01

    In 1888, Iowa weather researcher Gustavus Hinrichs gave widespread convectively induced windstorms the name "derecho". Refinements to this definition have evolved after numerous investigations of these systems; however, to date, a derecho climatology has not been conducted.This investigation examines spatial and temporal aspects of derechos and their associated mesoscale convective systems that occurred from 1986 to 1995. The spatial distribution of derechos revealed four activity corridors during the summer, five during the spring, and two during the cool season. Evidence suggests that the primary warm season derecho corridor is located in the southern Great Plains. During the cool season, derecho activity was found to occur in the southeast states and along the Atlantic seaboard. Temporally, derechos are primarily late evening or overnight events during the warm season and are more evenly distributed throughout the day during the cool season.

  10. Thermal environment in a simulated double office room with convective and radiant cooling systems

    DEFF Research Database (Denmark)

    Mustakallio, Panu; Bolashikov, Zhecho Dimitrov; Rezgals, Lauris

    2017-01-01

    anddraught rate was calculated. Manikin-based equivalent temperature (MBET) was determined by using two thermal manikins. CCMV provided slightly more uniform thermal environment and the least sensitive to different workstation layouts than the other systems. CB provided a bit higher draught rate levels than...

  11. Brayton isotope power system, phase I. Final report

    International Nuclear Information System (INIS)

    1978-01-01

    The Phase I program resulted in the development and ground demonstration of a dynamic power conversion system. The two key contractual objectives of 25% conversion efficiency and 1000 h of endurance testing were successfully met. As a result of the Phase I effort, the BIPS is a viable candidate for further development into a flight system capable of sustained operation in space. It represents the only known dynamic space power system to demonstrate the performance and endurance coupled with the simplicity necessary for reliable operation. This final report follows thirty-five monthly reports. For expediency, it makes liberal use of referenced documents which have been submitted to DOE during the course of the program

  12. Relationships of dispersive mass transport and stochastic convective flow through hydrologic systems

    International Nuclear Information System (INIS)

    Simmons, C.S.

    1981-01-01

    Uncertainty in water flow velocity appears to be a major factor in determining the magnitude of contaminant dispersion expected in a ground water system. This report discusses some concepts and mathematical methods relating dispersive contaminant transport to stochastic aspects of ground water flow. The theory developed should not be construed as absolutely rigorous mathematics, but is presented with the intention of clarifying the physical concepts

  13. National Convective Weather Forecast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NCWF is an automatically generated depiction of: (1) current convection and (2) extrapolated signficant current convection. It is a supplement to, but does NOT...

  14. The Next-Generation Goddard Convective-Stratiform Heating Algorithm: Addressing Higher Latitude, Cold Season, and Synoptic Systems

    Science.gov (United States)

    Wu, D.; Tao, W. K.; Lang, S. E.

    2016-12-01

    The Goddard Convective-Stratiform Heating (or CSH) algorithm is used to retrieve estimates of cloud heating over the global Tropics using TRMM rainfall data and a set of look-up-tables (LUTs) derived from a series of multi-week cloud-resolving model (CRM) simulations using the Goddard Cumulus Ensemble model (or GCE). These simulations link satellite observables (i.e., surface rainfall and stratiform fraction) with cloud heating profiles, which are not directly observable. The current CSH LUTs are differentiated with respect to surface rainfall characteristics, which is effective for tropical and continental summertime environments. However, with the launch of GPM in 2014, the range over which such algorithms can be applied has been extended from the Tropics and mid-latitudes to higher latitudes, including cold season and synoptic weather systems. Accordingly, the CSH algorithm and LUTs need to be updated for higher latitude events. In this study, NU-WRF was employed at 1 km to simulate winter systems in the US. A, new methodology has been adopted to construct LUTs utilizing satellite-observable 3D intensity fields, such as radar reflectivity. The new methodology/LUTs can be then applied to simulated radar fields to derive cloud heating for comparison against the model simulated heating. The model heating is treated as the `truth' as it is self-consistent with the simulated radar fields. This `consistency check' approach is a common well-established first step in algorithm development (e.g., the earlier CSH). The LUTs will be improved by iterating the consistency checks to quantitatively evaluate the similarities between the retrieved and simulated heating. The evaluations will be performed for different weather events, including northeast winter storms and atmospheric rivers.

  15. Protective barrier systems for final disposal of Hanford Waste Sites

    International Nuclear Information System (INIS)

    Phillips, S.J.; Hartley, J.N.

    1986-01-01

    A protecting barrier system is being developed for potential application in the final disposal of defense wastes at the Hanford Site. The functional requirements for the protective barrier are control of water infiltration, wind erosion, and plant and animal intrusion into the waste zone. The barrier must also be able to function without maintenance for the required time period (up to 10,000 yr). This paper summarizes the progress made and future plans in this effort to design and test protective barriers at the Hanford Site

  16. Bidispersive-inclined convection

    Science.gov (United States)

    Mulone, Giuseppe; Straughan, Brian

    2016-01-01

    A model is presented for thermal convection in an inclined layer of porous material when the medium has a bidispersive structure. Thus, there are the usual macropores which are full of a fluid, but there are also a system of micropores full of the same fluid. The model we employ is a modification of the one proposed by Nield & Kuznetsov (2006 Int. J. Heat Mass Transf. 49, 3068–3074. (doi:10.1016/j.ijheatmasstransfer.2006.02.008)), although we consider a single temperature field only. PMID:27616934

  17. NCAR's Experimental Real-time Convection-allowing Ensemble Prediction System

    Science.gov (United States)

    Schwartz, C. S.; Romine, G. S.; Sobash, R.; Fossell, K.

    2016-12-01

    Since April 2015, the National Center for Atmospheric Research's (NCAR's) Mesoscale and Microscale Meteorology (MMM) Laboratory, in collaboration with NCAR's Computational Information Systems Laboratory (CISL), has been producing daily, real-time, 10-member, 48-hr ensemble forecasts with 3-km horizontal grid spacing over the conterminous United States (http://ensemble.ucar.edu). These computationally-intensive, next-generation forecasts are produced on the Yellowstone supercomputer, have been embraced by both amateur and professional weather forecasters, are widely used by NCAR and university researchers, and receive considerable attention on social media. Initial conditions are supplied by NCAR's Data Assimilation Research Testbed (DART) software and the forecast model is NCAR's Weather Research and Forecasting (WRF) model; both WRF and DART are community tools. This presentation will focus on cutting-edge research results leveraging the ensemble dataset, including winter weather predictability, severe weather forecasting, and power outage modeling. Additionally, the unique design of the real-time analysis and forecast system and computational challenges and solutions will be described.

  18. Instabilities in parallel channel of forced-convection boiling upflow system, 5

    International Nuclear Information System (INIS)

    Aritomi, Masanori; Aoki, Shigebumi; Inoue, Akira

    1983-01-01

    The density wave instability in a parallel boiling channel system heated electrically has been studied experimentally and analytically by the authors. In our country, the steam generator for LMFBR has been investigated with Power Reactor and Nuclear Fuel Development Corp. as the central figure for its development, and many results of this instability were reported. Their results were different from our ones as regard to the governing factor of the period of flow oscillation in the unstable region and to the effect of the slip ratio on the stability in analysis. A new linear analytical model is proposed in this paper and the analytical results are compared with ones of two-phase analyses based on the same linear method as this model. Subsequently, the effect of the slip ratio on the stability is studied analytically by this model. The parallel boiling channel system is studied experimentally and analytically, using Freon-113 as test fluid heated by hot water as simulation of the SG for LMFBR. The governing factor of the period of flow oscillation is made clear. (author)

  19. Mantle Convection on Modern Supercomputers

    Science.gov (United States)

    Weismüller, J.; Gmeiner, B.; Huber, M.; John, L.; Mohr, M.; Rüde, U.; Wohlmuth, B.; Bunge, H. P.

    2015-12-01

    Mantle convection is the cause for plate tectonics, the formation of mountains and oceans, and the main driving mechanism behind earthquakes. The convection process is modeled by a system of partial differential equations describing the conservation of mass, momentum and energy. Characteristic to mantle flow is the vast disparity of length scales from global to microscopic, turning mantle convection simulations into a challenging application for high-performance computing. As system size and technical complexity of the simulations continue to increase, design and implementation of simulation models for next generation large-scale architectures is handled successfully only in an interdisciplinary context. A new priority program - named SPPEXA - by the German Research Foundation (DFG) addresses this issue, and brings together computer scientists, mathematicians and application scientists around grand challenges in HPC. Here we report from the TERRA-NEO project, which is part of the high visibility SPPEXA program, and a joint effort of four research groups. TERRA-NEO develops algorithms for future HPC infrastructures, focusing on high computational efficiency and resilience in next generation mantle convection models. We present software that can resolve the Earth's mantle with up to 1012 grid points and scales efficiently to massively parallel hardware with more than 50,000 processors. We use our simulations to explore the dynamic regime of mantle convection and assess the impact of small scale processes on global mantle flow.

  20. Modeling of convective drying kinetics of Pistachio kernels in a fixed bed drying system

    Directory of Open Access Journals (Sweden)

    Balbay Asım

    2013-01-01

    Full Text Available Drying kinetics of Pistachio kernels (PKs with initial moisture content of 32.4% (w.b was investigated as a function of drying conditions in a fixed bed drying system. The drying experiments were carried out at different temperatures of drying air (40, 60 and 80°C and air velocities (0.05, 0.075 and 0.1 m/s. Several experiments were performed in terms of mass of PKs (15g and 30g using a constant air velocity of 0.075 m/s. The fit quality of models was evaluated using the determination coefficient (R2, sum square error (SSE and root mean square error (RMSE. Among the selected models, the Midilli et al model was found to be the best models for describing the drying behavior of PKs. The activation energies were calculated as 29.2 kJ/mol and effective diffusivity values were calculated between 1.38 and 4.94x10-10 m2/s depending on air temperatures.

  1. Final design and status of the NSLS vacuum system

    International Nuclear Information System (INIS)

    Schuchman, J.C.

    1982-01-01

    We describe the final system, as built, reasons for changes and the general status of the NSLS. The NSLS is a dedicated facility for the purpose of producing synchrotron radiation. It consists of an electron linac-booster injector system, and two storage rings, one for uv research and the other for x-ray research. (Synchrotron radiation is produced by accelerating electrons in the storage rings.) The design current and energies are 1000 ma at 700 MeV for the vuv ring and 500 ma at 2.5 GeV for the x-ray ring. A total of 44 experimental beam ports are available for use. Since each beam port may be divided into two or more experimentall beam lines, it is quite plausible to have upward of 100 simultaneously operating beam lines

  2. Analysis of corrosion product transport in PWR primary system under non-convective condition

    International Nuclear Information System (INIS)

    Han, Byoung Sub

    1992-02-01

    Product TRANsport), which can predict the corrosion product and radioactivity transport within the primary coolant system, and also can be utilized for the computer simulation with actual plant data of currently operating Korean nuclear power plants to predict the transport of the radionuclides. In this study, the following problems will be updated, improved and compared with the already existing codes: 1) development and analysis of recent mechanistic modelling of corrosion product deposition, 2) application and modification due to the temperature kinetic effect, 3) separation of the effect of Fe, Co, Ni and Mn solubility rather than Fe solubility alone, and 4) consideration of Ni activation and recoil process. By applying the above updated and improved mechanisms, the corrosion product behavior in PWR of currently operating Korean unclear power plants has been simulated. In addition, the evaluation of particulate transport, independent solubility data of major radionuclides and acute nodalization were included and extended. Then, with the developed computer code, we have evaluated and analyzed the activity and corrosion product build-up controlled by many parameters such as pH, composition of metal, and auxiliary system performance

  3. On the role of convective systems over the northwest Pacific and monsoon activity over the Indian subcontinent

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Babu, A; Reason, C.

    been examined in relation to breaks in monsoon conditions over the Indian sub-continent during contrasting monsoon years. A see-saw nature of convection between the NWP and north Indian Ocean was found during the years with excess monsoon rainfall...

  4. SOFC/TEG hybrid mCHP system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    2012-03-15

    The starting point for this project have been the challenge has been to develop a cost effective solution with long term stability. This is where a focused effort in a strong consortium covering material research, module development and manufacture as well as device design and optimization can make a real difference. In March 2010 the SOFTEG phase II project was initiated and a cooperation organization was established to implement the project as a development and demonstration project involving the staff from all project partners. The project is now completed with excellent and documented outcome. The final results by Alpcon have been demonstration as a TEG-based mCHP system calls CHP Dual Engine Power System, which will be applicable as both a standalone TEG-CHP hybrid system, but also as an auxiliary power unit and power booster for the SOFC system. However the SOFC system cannot cover the household's heat demand alone so it is necessary to combine a SOFC system together with a water heater/boiler system to cover the peak heat demand of a residential house or a complex building. The SOFTEG project partners achieved significant results that mainly can be outlined as following: 1) University of Aarhus has improved the thermal stability of ZnSb by optimizing the concentration of Nano composite material. 2) The grain size and its influence on the sintering process by spark plasma method are investigated by Aarhus University, but further work seems to be necessary. 3) The TE material is going to commercialization by Aarhus University. 4) Aalborg University has prepared simulation tools for complex thermoelectric simulation in non-steady state condition. 5) The new type DCDC interleaved converter using the MPPT system for optimal power tracing is designed, build and tested by Aalborg University in cooperation with Alpcon. This task is included overall system design, control system implementation and power electronic control design. 6) Full scale practical

  5. Impact of Lake Okeechobee Sea Surface Temperatures on Numerical Predictions of Summertime Convective Systems over South Florida

    Science.gov (United States)

    Case, Jonathan L.; Splitt, Michael E.; Fuell, Kevin K.; Santos, Pablo; Lazarus, Steven M.; Jedlovec, Gary J.

    2009-01-01

    The NASA Short-term Prediction Research and Transition (SPoRT) Center, the Florida Institute of Technology, and the NOAA/NWS Weather Forecast Office at Miami, FL (MFL) are collaborating on a project to investigate the impact of using high-resolution, 2-km Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) composites within the Weather Research and Forecasting (WRF) prediction system. The NWS MFL is currently running WRF in real-time to support daily forecast operations, using the National Centers for Environmental Prediction Nonhydrostatic Mesoscale Model dynamical core within the NWS Science and Training Resource Center's Environmental Modeling System (EMS) software. Twenty-seven hour forecasts are run daily initialized at 0300, 0900, 1500, and 2100 UTC on a domain with 4-km grid spacing covering the southern half of Florida and adjacent waters of the Gulf of Mexico and Atlantic Ocean. The SSTs are initialized with the NCEP Real-Time Global (RTG) analyses at 1/12deg resolution. The project objective is to determine whether more accurate specification of the lower-boundary forcing over water using the MODIS SST composites within the 4-km WRF runs will result in improved sea fluxes and hence, more accurate e\\olutiono f coastal mesoscale circulations and the associated sensible weather elements. SPoRT conducted parallel WRF EMS runs from February to August 2007 identical to the operational runs at NWS MFL except for the use of MODIS SST composites in place of the RTG product as the initial and boundary conditions over water. During the course of this evaluation, an intriguing case was examined from 6 May 2007, in which lake breezes and convection around Lake Okeechobee evolved quite differently when using the high-resolution SPoRT MODIS SST composites versus the lower-resolution RTG SSTs. This paper will analyze the differences in the 6 May simulations, as well as examine other cases from the summer 2007 in which the WRF

  6. Practical reliability and uncertainty quantification in complex systems : final report.

    Energy Technology Data Exchange (ETDEWEB)

    Grace, Matthew D.; Ringland, James T.; Marzouk, Youssef M. (Massachusetts Institute of Technology, Cambridge, MA); Boggs, Paul T.; Zurn, Rena M.; Diegert, Kathleen V. (Sandia National Laboratories, Albuquerque, NM); Pebay, Philippe Pierre; Red-Horse, John Robert (Sandia National Laboratories, Albuquerque, NM)

    2009-09-01

    The purpose of this project was to investigate the use of Bayesian methods for the estimation of the reliability of complex systems. The goals were to find methods for dealing with continuous data, rather than simple pass/fail data; to avoid assumptions of specific probability distributions, especially Gaussian, or normal, distributions; to compute not only an estimate of the reliability of the system, but also a measure of the confidence in that estimate; to develop procedures to address time-dependent or aging aspects in such systems, and to use these models and results to derive optimal testing strategies. The system is assumed to be a system of systems, i.e., a system with discrete components that are themselves systems. Furthermore, the system is 'engineered' in the sense that each node is designed to do something and that we have a mathematical description of that process. In the time-dependent case, the assumption is that we have a general, nonlinear, time-dependent function describing the process. The major results of the project are described in this report. In summary, we developed a sophisticated mathematical framework based on modern probability theory and Bayesian analysis. This framework encompasses all aspects of epistemic uncertainty and easily incorporates steady-state and time-dependent systems. Based on Markov chain, Monte Carlo methods, we devised a computational strategy for general probability density estimation in the steady-state case. This enabled us to compute a distribution of the reliability from which many questions, including confidence, could be addressed. We then extended this to the time domain and implemented procedures to estimate the reliability over time, including the use of the method to predict the reliability at a future time. Finally, we used certain aspects of Bayesian decision analysis to create a novel method for determining an optimal testing strategy, e.g., we can estimate the 'best' location to

  7. Urban Integrated Industrial Cogeneration Systems Analysis. Phase II final report

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Through the Urban Integrated Industrial Cogeneration Systems Analysis (UIICSA), the City of Chicago embarked upon an ambitious effort to identify the measure the overall industrial cogeneration market in the city and to evaluate in detail the most promising market opportunities. This report discusses the background of the work completed during Phase II of the UIICSA and presents the results of economic feasibility studies conducted for three potential cogeneration sites in Chicago. Phase II focused on the feasibility of cogeneration at the three most promising sites: the Stockyards and Calumet industrial areas, and the Ford City commercial/industrial complex. Each feasibility case study considered the energy load requirements of the existing facilities at the site and the potential for attracting and serving new growth in the area. Alternative fuels and technologies, and ownership and financing options were also incorporated into the case studies. Finally, site specific considerations such as development incentives, zoning and building code restrictions and environmental requirements were investigated.

  8. Final design of thermal diagnostic system in SPIDER ion source

    Energy Technology Data Exchange (ETDEWEB)

    Brombin, M., E-mail: matteo.brombin@igi.cnr.it; Dalla Palma, M.; Pasqualotto, R.; Pomaro, N. [Consorzio RFX, Corso Stati Uniti 4, I-35127 Padova (Italy)

    2016-11-15

    The prototype radio frequency source of the ITER heating neutral beams will be first tested in SPIDER test facility to optimize H{sup −} production, cesium dynamics, and overall plasma characteristics. Several diagnostics will allow to fully characterise the beam in terms of uniformity and divergence and the source, besides supporting a safe and controlled operation. In particular, thermal measurements will be used for beam monitoring and system protection. SPIDER will be instrumented with mineral insulated cable thermocouples, both on the grids, on other components of the beam source, and on the rear side of the beam dump water cooled elements. This paper deals with the final design and the technical specification of the thermal sensor diagnostic for SPIDER. In particular the layout of the diagnostic, together with the sensors distribution in the different components, the cables routing and the conditioning and acquisition cubicles are described.

  9. Final design of thermal diagnostic system in SPIDER ion source

    International Nuclear Information System (INIS)

    Brombin, M.; Dalla Palma, M.; Pasqualotto, R.; Pomaro, N.

    2016-01-01

    The prototype radio frequency source of the ITER heating neutral beams will be first tested in SPIDER test facility to optimize H"− production, cesium dynamics, and overall plasma characteristics. Several diagnostics will allow to fully characterise the beam in terms of uniformity and divergence and the source, besides supporting a safe and controlled operation. In particular, thermal measurements will be used for beam monitoring and system protection. SPIDER will be instrumented with mineral insulated cable thermocouples, both on the grids, on other components of the beam source, and on the rear side of the beam dump water cooled elements. This paper deals with the final design and the technical specification of the thermal sensor diagnostic for SPIDER. In particular the layout of the diagnostic, together with the sensors distribution in the different components, the cables routing and the conditioning and acquisition cubicles are described.

  10. Magnetic Fields in the Solar Convection Zone

    Directory of Open Access Journals (Sweden)

    Fan Yuhong

    2004-07-01

    Full Text Available Recent studies of the dynamic evolution of magnetic flux tubes in the solar convection zone are reviewed with focus on emerging flux tubes responsible for the formation of solar active regions. The current prevailing picture is that active regions on the solar surface originate from strong toroidal magnetic fields generated by the solar dynamo mechanism at the thin tachocline layer at the base of the solar convection zone. Thus the magnetic fields need to traverse the entire convection zone before they reach the photosphere to form the observed solar active regions. This review discusses results with regard to the following major topics: 1. the equilibrium properties of the toroidal magnetic fields stored in the stable overshoot region at the base of the convection zone, 2. the buoyancy instability associated with the toroidal magnetic fields and the formation of buoyant magnetic flux tubes, 3. the rise of emerging flux loops through the solar convective envelope as modeled by the thin flux tube calculations which infer that the field strength of the toroidal magnetic fields at the base of the solar convection zone is significantly higher than the value in equipartition with convection, 4. the minimum twist needed for maintaining cohesion of the rising flux tubes, 5. the rise of highly twisted kink unstable flux tubes as a possible origin of d -sunspots, 6. the evolution of buoyant magnetic flux tubes in 3D stratified convection, 7. turbulent pumping of magnetic flux by penetrative compressible convection, 8. an alternative mechanism for intensifying toroidal magnetic fields to significantly super-equipartition field strengths by conversion of the potential energy associated with the superadiabatic stratification of the solar convection zone, and finally 9. a brief overview of our current understanding of flux emergence at the surface and post-emergence evolution of the subsurface magnetic fields.

  11. Acoustic Resonance Spectroscopy (ARS) Munition Classification System enhancements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vela, O.A.; Huggard, J.C.

    1997-09-18

    Acoustic Resonance Spectroscopy (ARS) is a non-destructive evaluation technology developed at the Los Alamos National Laboratory (LANL). This technology has resulted in three generations of instrumentation, funded by the Defense Special Weapons Agency (DSWA), specifically designed for field identification of chemical weapon (CW) munitions. Each generation of ARS instrumentation was developed with a specific user in mind. The ARS1OO was built for use by the U.N. Inspection Teams going into Iraq immediately after the Persian Gulf War. The ARS200 was built for use in the US-Russia Bilateral Chemical Weapons Treaty (the primary users for this system are the US Onsite Inspection Agency (OSIA) and their Russian counterparts). The ARS300 was built with the requirements of the Organization for the Prohibition of Chemical Weapons (OPCW) in mind. Each successive system is an improved version of the previous system based on learning the weaknesses of each and, coincidentally, on the fact that more time was available to do a requirements analysis and the necessary engineering development. The ARS300 is at a level of development that warrants transferring the technology to a commercial vendor. Since LANL will supply the computer software to the selected vendor, it is possible for LANL to continue to improve the decision algorithms, add features where necessary, and adjust the user interface before the final transfer occurs. This paper describes the current system, ARS system enhancements, and software enhancements. Appendices contain the Operations Manual (software Version 3.01), and two earlier reports on enhancements.

  12. Antartic observations of plasma convection

    International Nuclear Information System (INIS)

    Hansen, H.J.

    1983-01-01

    This thesis is concerned with the use of whistler duct tracking as a diagnostic for the behaviour of plasma in the plasmasphere. As a setting for the results given in the thesis, a broad review is presented which embraces pertinent aspects of previous experimental and theoretical studies of the plasmasphere. From a study of 24 hours of continuous whistler data recorded at Sanae, (L = 3,98), it is shown that associated with quiet magnetic conditions (Av Ksub(p)=1), there exists two plasmasphere bulges centred on about 1700 and 0100 UT. There is evidence that these plasmasphere bulge structures are part of a ground-state or reference base drift pattern. Electric field measurements provide some evidence that quiet time plasmasphere drift behaviour is controlled by the internal ionospheric current systems of dynamo origin, rather than being controlled by magnetospheric convection. Finally, this thesis describes an application of the whistler duct tracking technique to whistler data recorded simultaneously at two ground-based stations (Sanae (L = 3,98) and Halley (L = 4,23)). The identification of common whistler components on each station's data set provides a means of estimating the lifetimes of the associated whistler ducts. Duct lifetimes of as little as 30 minutes are found. Such short lived ducts have important implications for current theories of duct formation

  13. Commercial thermal distribution systems, Final report for CIEE/CEC

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tengfang; Bechu, Olivier; Carrie, Remi; Dickerhoff, Darryl; Fisk, William; Franconi, Ellen; Kristiansen, Oyvind; Levinson, Ronnen; McWilliams, Jennifer; Wang, Duo; Modera, Mark; Webster, Tom; Ring, Erik; Zhang, Qiang; Huizenga, Charlie; Bauman, Fred; Arens, Ed

    1999-12-01

    According to the California Energy Commission (CEC 1998a), California commercial buildings account for 35% of statewide electricity consumption, and 16% of statewide gas consumption. Space conditioning accounts for roughly 16,000 GWh of electricity and 800 million therms of natural gas annually, and the vast majority of this space conditioning energy passes through thermal distribution systems in these buildings. In addition, 8600 GWh per year is consumed by fans and pumps in commercial buildings, most of which is used to move the thermal energy through these systems. Research work at Lawrence Berkeley National Laboratory (LBNL) has been ongoing over the past five years to investigate the energy efficiency of these thermal distribution systems, and to explore possibilities for improving that energy efficiency. Based upon that work, annual savings estimates of 1 kWh/ft{sup 2} for light commercial buildings, and 1-2 kWh/ft{sup 2} in large commercial buildings have been developed for the particular aspects of thermal distribution system performance being addressed by this project. Those savings estimates, combined with a distribution of the building stock based upon an extensive stock characterization study (Modera et al. 1999a), and technical penetration estimates, translate into statewide saving potentials of 2000 GWh/year and 75 million thermal/year, as well as an electricity peak reduction potential of 0.7 GW. The overall goal of this research program is to provide new technology and application knowledge that will allow the design, construction, and energy services industries to reduce the energy waste associated with thermal distribution systems in California commercial buildings. The specific goals of the LBNL efforts over the past year were: (1) to advance the state of knowledge about system performance and energy losses in commercial-building thermal distribution systems; (2) to evaluate the potential of reducing thermal losses through duct sealing, duct

  14. Electron beam final focus system for Thomson scattering at ELBE

    Energy Technology Data Exchange (ETDEWEB)

    Krämer, J.M., E-mail: jmkr@danfysik.dk [Danfysik A/S, Gregersensvej 8, 2630 Taastrup (Denmark); Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstrasse 400, 01328 Dresden (Germany); Technische Universität Dresden, 01069 Dresden (Germany); Budde, M.; Bødker, F. [Danfysik A/S, Gregersensvej 8, 2630 Taastrup (Denmark); Irman, A.; Jochmann, A. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstrasse 400, 01328 Dresden (Germany); Kristensen, J.P. [Danfysik A/S, Gregersensvej 8, 2630 Taastrup (Denmark); Lehnert, U.; Michel, P. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstrasse 400, 01328 Dresden (Germany); Schramm, U. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Bautzner Landstrasse 400, 01328 Dresden (Germany); Technische Universität Dresden, 01069 Dresden (Germany)

    2016-09-11

    The design of an electron beam final focus system (FFS) aiming for high-flux laser-Thomson backscattering X-ray sources at ELBE is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole doublet or triplet as commonly used. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. The desired ultra-short electron bunches require an increased relative energy spread up to a few percent and, thus, second order chromatic effects must be taken into account. We also present the design and test results of the permanent magnet quadrupoles. Adjustable shunts allow for correction of the field strength and compensation of deviations in the permanent magnet material. For a beam emittance of 13 mm mrad, we predict focal spot sizes of about 40 μm (rms) and divergences of about 10 mrad using the FFS.

  15. Electron beam final focus system for Thomson scattering at ELBE

    CERN Document Server

    Krämer, J.M.; Bødker, F.; Irman, A.; .Jochmann A.; Kristensen, J.P.; Lehnert U., HZDR; Michel, P.; Schrammb, U.; 10.1016/j.nima.2015.10.067

    2016-01-01

    The design of an electron beam final focus system (FFS) aiming for high-flux laser-Thomson backscattering X-ray sources at ELBE is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole doublet or triplet as commonly used. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. The desired ultra-short electron bunches require an increased relative energy spread up to a few percent and, thus, second order chromatic effects must be taken into account. We also present the design and test results of the permanent magnet quadrupoles. Adjustable shunts allow for correction of the field strength and compensation of deviations in the permanent magnet material. For a beam emittance of 13 mm mrad, we predict focal spot sizes of about 40 μm (rms) and diverg...

  16. Electron Beam Final Focus System For Thomson Scattering At Elbe

    CERN Document Server

    Krämer, J.M.; Bødkera, F.; Irman, A.; Jochmann, A.; Kristensena, J.P.; Lehnert, U.; Michel, P.; Schramm, U.; 10.1016/j.nima.2015.10.067

    2016-01-01

    The design of an electron beam final focus system (FFS) aiming for high-flux laser-Thomson backscattering X-ray sources at ELBE is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole doublet or triplet as commonly used. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. The desired ultra-short electron bunches require an increased relative energy spread up to a few percent and, thus, second order chromatic effects must be taken into account. We also present the design and test results of the permanent magnet quadrupoles. Adjustable shunts allow for correction of the field strength and compensation of deviations in the permanent magnet material. For a beam emittance of 13 mm mrad, we predict focal spot sizes of about 40 μm (rms) and diverg...

  17. Foundations for Improvements to Passive Detection Systems - Final Report

    International Nuclear Information System (INIS)

    Labov, S E; Pleasance, L; Sokkappa, P; Craig, W; Chapline, G; Frank, M; Gronberg, J; Jernigan, J G; Johnson, S; Kammeraad, J; Lange, D; Meyer, A; Nelson, K; Pohl, B; Wright, D; Wurtz, R

    2004-01-01

    This project explores the scientific foundation and approach for improving passive detection systems for plutonium and highly enriched uranium in real applications. Sources of gamma-ray radiation of interest were chosen to represent a range of national security threats, naturally occurring radioactive materials, industrial and medical radiation sources, and natural background radiation. The gamma-ray flux emerging from these sources, which include unclassified criticality experiment configurations as surrogates for nuclear weapons, were modeled in detail. The performance of several types of gamma-ray imaging systems using Compton scattering were modeled and compared. A mechanism was created to model the combine sources and background emissions and have the simulated radiation ''scene'' impinge on a model of a detector. These modeling tools are now being used in various projects to optimize detector performance and model detector sensitivity in complex measuring environments. This study also developed several automated algorithms for isotope identification from gamma-ray spectra and compared these to each other and to algorithms already in use. Verification testing indicates that these alternative isotope identification algorithms produced less false positive and false negative results than the ''GADRAS'' algorithms currently in use. In addition to these algorithms that used binned spectra, a new approach to isotope identification using ''event mode'' analysis was developed. Finally, a technique using muons to detect nuclear material was explored

  18. Final focus system tuning studies towards Compact Linear Collider feasibility

    Science.gov (United States)

    Marin, E.; Latina, A.; Tomás, R.; Schulte, D.

    2018-01-01

    In this paper we present the latest results regarding the tuning study of the baseline design of the final focus system of the Compact Linear Collider (CLIC-FFS). CLIC aims to provide collisions to the experiments at a luminosity above 1034 c m-2 s-1 . In order to deliver such luminosity in a single pass machine, the vertical beam size at the interaction point (IP) is reduced to about 1 nm, which imposes unprecedented tuning difficulties to the system. In previous studies, 90% of the machines reached 90% of the nominal luminosity at the expense of 18 000 luminosity measurements, when considering beam position monitor errors and transverse misalignments of magnets for a single beam case. In the present study, additional static imperfections as, roll misalignments, strength v2.epss are included. Moreover both e- and e+ beamlines are properly simulated. A new tuning procedure based on linear and nonlinear knobs is implemented to effectively cure the most relevant beam size aberrations at the IP. The obtained results for single and double beam studies under solely static imperfections are presented.

  19. Behaviors and transitions along the path to magnetostrophic convection

    Science.gov (United States)

    Grannan, A. M.; Vogt, T.; Horn, S.; Hawkins, E. K.; Aggarwal, A.; Aurnou, J. M.

    2017-12-01

    The generation of magnetic fields in planetary and stellar interiors are believed to be controlled primarily by turbulent convection constrained by Coriolis and Lorentz forces in their electrically conducting fluid layers. Yet relatively few laboratory experiments are capable of investigating the different regimes of turbulent magnetohydrodynamic convection. In this work, we perform one laboratory experiment in a cylinder at a fixed heat flux using the liquid metal gallium in order to investigate, sequentially: Rayleigh-Bènard convection without any imposed constraints, magnetoconvection with a Lorentz constraint imposed by vertical magnetic field, rotating convection with a Coriolis constraint imposed by rotation, and finally the magnetostrophic convective regime where both Coriolis and Lorentz are imposed and equal. Using an array of internal and external temperature probes, we show that each regime along the path to magnetostrophic convection is unique. The behaviors and transitions in the dominant modes of convection as well as their fundamental frequencies and wavenumbers are investigated.

  20. Double-diffusive convection and baroclinic instability in a differentially heated and initially stratified rotating system: the barostrat instability

    Energy Technology Data Exchange (ETDEWEB)

    Vincze, Miklos; Borcia, Ion; Harlander, Uwe [Department of Aerodynamics and Fluid Mechanics, Brandenburg University of Technology (BTU) Cottbus-Senftenberg, Siemens-Halske-Ring 14, D-03046 Cottbus (Germany); Gal, Patrice Le, E-mail: vincze.m@lecso.elte.hu [Institut de Recherche sur les Phénomènes Hors Equilibre, CNRS—Aix-Marseille University—Ecole Centrale Marseille, 49 rue F. Joliot-Curie, F-13384 Marseille (France)

    2016-12-15

    A water-filled differentially heated rotating annulus with initially prepared stable vertical salinity profiles is studied in the laboratory. Based on two-dimensional horizontal particle image velocimetry data and infrared camera visualizations, we describe the appearance and the characteristics of the baroclinic instability in this original configuration. First, we show that when the salinity profile is linear and confined between two non-stratified layers at top and bottom, only two separate shallow fluid layers can be destabilized. These unstable layers appear nearby the top and the bottom of the tank with a stratified motionless zone between them. This laboratory arrangement is thus particularly interesting to model geophysical or astrophysical situations where stratified regions are often juxtaposed to convective ones. Then, for more general but stable initial density profiles, statistical measures are introduced to quantify the extent of the baroclinic instability at given depths and to analyze the connections between this depth-dependence and the vertical salinity profiles. We find that, although the presence of stable stratification generally hinders full-depth overturning, double-diffusive convection can lead to development of multicellular sideways convection in shallow layers and subsequently to a multilayered baroclinic instability. Therefore we conclude that by decreasing the characteristic vertical scale of the flow, stratification may even enhance the formation of cyclonic and anticyclonic eddies (and thus, mixing) in a local sense. (paper)

  1. Double-diffusive convection and baroclinic instability in a differentially heated and initially stratified rotating system: the barostrat instability

    International Nuclear Information System (INIS)

    Vincze, Miklos; Borcia, Ion; Harlander, Uwe; Gal, Patrice Le

    2016-01-01

    A water-filled differentially heated rotating annulus with initially prepared stable vertical salinity profiles is studied in the laboratory. Based on two-dimensional horizontal particle image velocimetry data and infrared camera visualizations, we describe the appearance and the characteristics of the baroclinic instability in this original configuration. First, we show that when the salinity profile is linear and confined between two non-stratified layers at top and bottom, only two separate shallow fluid layers can be destabilized. These unstable layers appear nearby the top and the bottom of the tank with a stratified motionless zone between them. This laboratory arrangement is thus particularly interesting to model geophysical or astrophysical situations where stratified regions are often juxtaposed to convective ones. Then, for more general but stable initial density profiles, statistical measures are introduced to quantify the extent of the baroclinic instability at given depths and to analyze the connections between this depth-dependence and the vertical salinity profiles. We find that, although the presence of stable stratification generally hinders full-depth overturning, double-diffusive convection can lead to development of multicellular sideways convection in shallow layers and subsequently to a multilayered baroclinic instability. Therefore we conclude that by decreasing the characteristic vertical scale of the flow, stratification may even enhance the formation of cyclonic and anticyclonic eddies (and thus, mixing) in a local sense. (paper)

  2. Dissemination of Continuing Education Materials Via Television Delivery Systems. Final Technical Report and Final Report.

    Science.gov (United States)

    Munushian, Jack

    In 1972, the University of Southern California School of Engineering established a 4-channel interactive instructional television network. It was designed to allow employees of participating industries to take regular university science and engineering courses and special continuing education courses at or near their work locations. Final progress…

  3. Expanded studies of linear collider final focus systems at the Final Focus Test Beam

    International Nuclear Information System (INIS)

    Tenenbaum, P.G.

    1995-12-01

    In order to meet their luminosity goals, linear colliders operating in the center-of-mass energy range from 3,50 to 1,500 GeV will need to deliver beams which are as small as a few Manometers tall, with x:y aspect ratios as large as 100. The Final Focus Test Beam (FFTB) is a prototype for the final focus demanded by these colliders: its purpose is to provide demagnification equivalent to those in the future linear collider, which corresponds to a focused spot size in the FFTB of 1.7 microns (horizontal) by 60 manometers (vertical). In order to achieve the desired spot sizes, the FFTB beam optics must be tuned to eliminate aberrations and other errors, and to ensure that the optics conform to the desired final conditions and the measured initial conditions of the beam. Using a combination of incoming-beam diagnostics. beam-based local diagnostics, and global tuning algorithms, the FFTB beam size has been reduced to a stable final size of 1.7 microns by 70 manometers. In addition, the chromatic properties of the FFTB have been studied using two techniques and found to be acceptable. Descriptions of the hardware and techniques used in these studies are presented, along with results and suggestions for future research

  4. Expanded studies of linear collider final focus systems at the Final Focus Test Beam

    Energy Technology Data Exchange (ETDEWEB)

    Tenenbaum, Peter Gregory [Stanford Univ., CA (United States)

    1995-12-01

    In order to meet their luminosity goals, linear colliders operating in the center-of-mass energy range from 3,50 to 1,500 GeV will need to deliver beams which are as small as a few Manometers tall, with x:y aspect ratios as large as 100. The Final Focus Test Beam (FFTB) is a prototype for the final focus demanded by these colliders: its purpose is to provide demagnification equivalent to those in the future linear collider, which corresponds to a focused spot size in the FFTB of 1.7 microns (horizontal) by 60 manometers (vertical). In order to achieve the desired spot sizes, the FFTB beam optics must be tuned to eliminate aberrations and other errors, and to ensure that the optics conform to the desired final conditions and the measured initial conditions of the beam. Using a combination of incoming-beam diagnostics. beam-based local diagnostics, and global tuning algorithms, the FFTB beam size has been reduced to a stable final size of 1.7 microns by 70 manometers. In addition, the chromatic properties of the FFTB have been studied using two techniques and found to be acceptable. Descriptions of the hardware and techniques used in these studies are presented, along with results and suggestions for future research.

  5. Astronaut Neil A. Armstrong Undergoes Communications Systems Final Check

    Science.gov (United States)

    1969-01-01

    Dunned in his space suit, mission commander Neil A. Armstrong does a final check of his communications system before before the boarding of the Apollo 11 mission. Launched via a Saturn V launch vehicle, the first manned lunar mission launched from the Kennedy Space Center, Florida on July 16, 1969 and safely returned to Earth on July 24, 1969. The Saturn V vehicle was developed by the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun. The 3-man crew aboard the flight consisted of astronauts Armstrong; Michael Collins, Command Module (CM) pilot; and Edwin E. Aldrin, Jr., Lunar Module (LM) Pilot. Armstrong was the first human to ever stand on the lunar surface, followed by Edwin (Buzz) Aldrin. Meanwhile, astronaut Collins piloted the CM in a parking orbit around the Moon. During a 2½ hour surface exploration, the crew collected 47 pounds of lunar surface material which was returned to Earth for analysis. With the success of Apollo 11, the national objective to land men on the Moon and return them safely to Earth had been accomplished.

  6. Variability of Oceanic Mesoscale Convective System Vertical Structures Observed by CloudSat in Indo-Pacific Regions Associated with the Madden-Julian Oscillation

    Science.gov (United States)

    Yuan, J.

    2016-12-01

    Vertical structures of mesoscale convective systems (MCSs) during the Madden-Julian-Oscillation (MJO) are investigated using 2006-2011 CloudSat radar measurements for Indo-Pacific oceanic areas. In active phases of the MJO relatively more large MCSs and connected MCSs occur. The frequency of occurrence of connected MCSs peaks in the onset phase, a phase earlier than separated MCSs. Compared to separated MCSs, connected MCSs in all sizes have weaker reflectivity above 8 km in their deep precipitating portions and thick anvil clouds closely linked to them, suggesting more "stratiform" physics associated with them. Separated MCSs and connected MCSs together produce relatively the least anvil clouds in the onset phase while their deep precipitating portions show stronger/weaker reflectivity above 8 km before/after the onset phase. Thus after the onset phase of the MJO, MCSs shift toward more "convective" organization because separated MCSs maximize after the onset, while their internal structures appear more "stratiform" because internally they have weaker reflectivity above 8km. Connected MCSs coincide with a more humid middle troposphere spatially, even at the same places a few days before they occur. Middle-tropospheric moistening peaks in the onset phase. Moistening of the free troposphere around deep convective systems shows relatively stronger moistening/drying below the 700 hPa before/after the onset phase compared to domain-mean averages. Lower-topped clouds occur most frequently around CMCSs and in active phases, consistent with the presence of a moister free troposphere. Coexistence of these phenomena suggests that the role of middle troposphere moisture in the formation of CMCSs needs to be better understood.

  7. Field Demonstration of Active Desiccant-Based Outdoor Air Preconditioning Systems, Final Report: Phase 3; FINAL

    International Nuclear Information System (INIS)

    Fischer, J.

    2001-01-01

    This report summarizes an investigation of the performance of two active desiccant cooling systems that were installed as pilot systems in two locations-a college dormitory and a research laboratory-during the fall of 1999. The laboratory system was assembled in the field from commercially available Trane air-handling modules combined with a standard total energy recovery module and a customized active desiccant wheel, both produced by SEMCO. The dormitory system was a factory-built, integrated system produced by SEMCO that included both active desiccant and sensible-only recovery wheels, a direct-fired gas regeneration section, and a pre-piped Trane heat pump condensing section. Both systems were equipped with direct digital control systems, complete with full instrumentation and remote monitoring capabilities. This report includes detailed descriptions of these two systems, installation details, samples of actual performance, and estimations of the energy savings realized. These pi lot sites represent a continuation of previous active desiccant product development research (Fischer, Hallstrom, and Sand 2000; Fischer 2000). Both systems performed as anticipated, were reliable, and required minimal maintenance. The dehumidification/total-energy-recovery hybrid approach was particularly effective in all respects. System performance showed remarkable improvement in latent load handling capability and operating efficiency compared with the original conventional cooling system and with the conventional system that remained in another, identical wing of the facility. The dehumidification capacity of the pilot systems was very high, the cost of operation was very low, and the system was cost-effective, offering a simple payback for these retrofit installations of approximately 5 to 6 years. Most important, the dormitory system resolved numerous indoor air quality problems in the dormitory by providing effective humidity control and increased, continuous ventilation air

  8. Southern Ocean Convection and tropical telleconnections

    Science.gov (United States)

    Marinov, I.; Cabre, A.; Gnanadesikan, A.

    2014-12-01

    We show that Southern Ocean (SO) temperatures in the latest generation of Earth System Models exhibit two major modes of variation, one driven by deep convection, the other by tropical variability. We perform a CMIP5 model intercomparison to understand why different climate models represent SO variability so differently in long, control simulations. We show that multiyear variability in Southern Ocean sea surface temperatures (SSTs) can in turn influence oceanic and atmospheric conditions in the tropics on short (atmospheric) time-scales. We argue that the strength and pattern of SO-tropical teleconnections depends on the intensity of SO deep convection. Periodic convection in the SO is a feature of most CMIP5 models under preindustrial forcing (deLavergne et al., 2014). Models show a wide distribution in the spatial extent, periodicity and intensity of their SO convection, with some models convecting most of the time, and some showing very little convection. In a highly convective coupled model, we find that multidecadal variability in SO and global SSTs, as well as SO heat storage are driven by Weddell Sea convective variability, with convective decades relatively warm due to the heat released from the deep southern ocean and non-convective decades cold due to the subsurface storage of heat. Furthermore, pulses of SO convection drive SST and sea ice variations, influencing absorbed shortwave and emitted longwave radiation, wind, cloud and precipitation patterns, with climatic implications for the low latitudes via fast atmospheric teleconnections. We suggest that these high-low latitude teleconnection mechanisms are relevant for understanding hiatus decades. Additionally, Southern Ocean deep convection varied significantly during past, natural climate changes such as during the last deglaciation. Weddell Sea open convection was recently weakened, likely as a consequence of anthropogenic forcing and the resulting surface freshening. Our study opens up the

  9. The response of a simulated mesoscale convective system to increased aerosol pollution: Part II: Derecho characteristics and intensity in response to increased pollution

    Science.gov (United States)

    Clavner, Michal; Grasso, Lewis D.; Cotton, William R.; van den Heever, Susan C.

    2018-01-01

    Mesoscale Convective Systems (MCS) are important contributors to rainfall as well as producers of severe weather such as hail, tornados, and straight-line wind events known as derechos. In this study, different aerosol concentrations and their effects on a derecho event are examined by simulating a case study, the 8 May 2009 "Super-Derecho", using the Regional Atmospheric Modeling System (RAMS), a cloud-resolving model with sophisticated aerosol and cloud microphysics. Three simulations were conducted that differed in the initial aerosol concentrations, spatial distribution and chemical composition as derived from output of GEOS-Chem, a 3D chemical transport model. In order to understand the impact of changes in aerosol concentrations on the derecho characteristics, the dynamical processes that produced the strong surface wind were determined by performing back-trajectory analysis during two periods of the simulated storm: the development and the onset of dissipation. A time dependent and non-monotonic trend was found between the intensity of the derecho and the increased aerosol concentrations that served as cloud condensation nuclei. During the formation period of the MCS, the non-monotonic trend was attributed to the microphysical impact of aerosol loading on the intensity of the cold pool; that is, the impact of aerosols on both the melting and evaporation rates of hydrometeors. The subsequent intensity changes within the cold pool modified the balance between the horizontal vorticity generated by the cold pool and that of the environment, thereby impacting the orientation of the convective updraft at the leading line. This, in turn, altered the primary flow that contributed to the formation of the derecho-strength surface winds. The simulation with no anthropogenic aerosols exhibited the strongest cold pool and the primary flow was associated with a descending rear inflow jet that produced the derecho winds over a larger region. The simulation with the highest

  10. Systems study 'Alternative Entsorgung'. Final report. Technical annex 6

    International Nuclear Information System (INIS)

    1984-08-01

    In the conditioning plant, fuel elements which have been stored for ten years are loaded into transport containers, unloaded, identified and welded into a dry storage box. The dry store barrel is introduced into a final storage container, which, after being closed, is packed in lost shielding. This so-called final storage barrel is finally placed in a transport container and leaves the conditioning plant in this form by rail for transport to the final storage mine. The fuel element method of treatment 'packing of three complete fuel elements' was used as the reference process. In addition, the method of treatment 'fuel elements dismantled into fuel rods' was also examined. The handling of fuel elements and secondary waste treatment in the reference process are described in detail. (orig./HP) [de

  11. A final focus system for the Next Linear Collider

    International Nuclear Information System (INIS)

    Zimmermann, F.; Brown, K.; Emma, P.; Helm, R.; Irwin, J.; Tenenbaum, P.; Wilson, P.

    1995-06-01

    The final focus of the Next Linear Collider (NLC) demagnifies electron and positron beams of 250--750 GeV energy down to a transverse size of about 2.5 x 350 nm 2 at the interaction point (IP). The basic layout, momentum bandwidth, vibration tolerances, wakefield effects, and the tunability of the proposed final focus design are discussed. Also a perspective is given on the crab cavity and on effects of the solenoid field in the interaction region

  12. The Relationship Between Latent Heating, Vertical Velocity, and Precipitation Processes: the Impact of Aerosols on Precipitation in Organized Deep Convective Systems

    Science.gov (United States)

    Tao, Wei-Kuo; Li, Xiaowen

    2016-01-01

    A high-resolution, two-dimensional cloud-resolving model with spectral-bin microphysics is used to study the impact of aerosols on precipitation processes in both a tropical oceanic and a midlatitude continental squall line with regard to three processes: latent heating (LH), cold pool dynamics, and ice microphysics. Evaporative cooling in the lower troposphere is found to enhance rainfall in low cloud condensation nuclei (CCN) concentration scenarios in the developing stages of a midlatitude convective precipitation system. In contrast, the tropical case produced more rainfall under high CCN concentrations. Both cold pools and low-level convergence are stronger for those configurations having enhanced rainfall. Nevertheless, latent heat release is stronger (especially after initial precipitation) in the scenarios having more rainfall in both the tropical and midlatitude environment. Sensitivity tests are performed to examine the impact of ice and evaporative cooling on the relationship between aerosols, LH, and precipitation processes. The results show that evaporative cooling is important for cold pool strength and rain enhancement in both cases. However, ice microphysics play a larger role in the midlatitude case compared to the tropics. Detailed analysis of the vertical velocity-governing equation shows that temperature buoyancy can enhance updraftsdowndrafts in the middlelower troposphere in the convective core region; however, the vertical pressure gradient force (PGF) is of the same order and acts in the opposite direction. Water loading is small but of the same order as the net PGF-temperature buoyancy forcing. The balance among these terms determines the intensity of convection.

  13. Structural Characteristics of Nocturnal Mesoscale Convective Systems in the U.S. Great Plains as Observed During the PECAN Field Campaign

    Science.gov (United States)

    Bodine, D. J.; Dougherty, E.; Rasmussen, K. L.; Torres, A. D.

    2015-12-01

    During the summer in the U.S. Great Plains, some of the heaviest precipitation falls from large thunderstorm complexes known as Mesoscale Convective Systems (MCSs). These frequently occurring MCSs are often nocturnal in nature, so the dynamics associated with these systems are more elusive than those in the daytime. The Plains Elevated Convection at Night (PECAN) field campaign was launched over a 7-week period as an endeavor to better understand nocturnal MCSs occurring in the Great Plains. PECAN featured a dense array of ground-based and airborne instruments to observe nocturnal MCS, including dual-polarization radars at multiple frequencies, mobile mesonets, and sounding units. Our role in PECAN involved deploying Ott Parsivel disdrometers to gain information on drop size distributions (DSDs) and fall speeds. Analysis of disdrometer data in conjunction with radar data presented using Contour Frequency by Altitude Diagrams (CFADs) and high-resolution radiosonde data allows for a structural comparison of PECAN MCS cases to previously identified MCS archetypes. Novel insights into the structural evolution of nocturnal MCSs in relation to their synoptic, mesoscale, and thermodynamic environments are presented, using data collected from dense and numerous observation platforms. Understanding the environmental conditions that result in different nocturnal MCS configurations is useful for gaining insight into precipitation distributions and potential severe weather and flooding hazards in the Great Plains.

  14. Artificial intelligence systems for rainy areas detection and convective cells' delineation for the south shore of Mediterranean Sea during day and nighttime using MSG satellite images

    Science.gov (United States)

    Tebbi, Mohsene Abdelfettah; Haddad, Boualem

    2016-09-01

    The aim of this study is to investigate the potential of cloud classification by means of support vector machines using high resolution images from northern Algeria. The images were taken from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board of the Meteosat Second Generation (MSG) satellite. An automatic system was developed to operate during both day and nighttime by following two steps of data processing. The first aims to detect rainy areas in cloud systems, whereas the second delineates convective cells from stratiform ones. A set of 12 spectral parameters was selected to extract information about cloud properties, which are different from day to night. The training and validation steps of this study were performed by in-situ rainfall measurement data, collected during the rainy season of years 2011 and 2012 via automatic rain gauge stations distributed in northern Algeria. Artificial neural networks (ANNs) and support vector machine (SVM) were explored, by combining spectral parameters derived from MSG images. Better performances were obtained by the SVM classifier, in terms of Critical Success Index and Probability of Detection for rainy areas detection (CSI = 0.81, POD = 91%), and also for convective/stratiform delineation (CSI = 0.55, POD = 74%).

  15. LOFT integral test system final safety analysis report

    International Nuclear Information System (INIS)

    1974-03-01

    Safety analyses are presented for the following LOFT Reactor systems: engineering safety features; support buildings and facilities; instrumentation and controls; electrical systems; and auxiliary systems. (JWR)

  16. Thermosolutal convection during dendritic solidification

    Science.gov (United States)

    Heinrich, J. C.; Nandapurkar, P.; Poirier, D. R.; Felicelli, S.

    1989-01-01

    This paper presents a mathematical model for directional solidification of a binary alloy including a dendritic region underlying an all-liquid region. It is assumed initially that there exists a nonconvecting state with planar isotherms and isoconcentrates solidifying at a constant velocity. The stability of this system has been analyzed and nonlinear calculations are performed that show the effect of convection in the solidification process when the system is unstable. Results of calculations for various cases defined by the initial temperature gradient at the dendrite tips and varying strength of the gravitational field are presented for systems involving lead-tin alloys. The results show that the systems are stable for a gravitational constant of 0.0001 g(0) and that convection can be suppressed by appropriate choice of the container's size for higher values of the gravitational constant. It is also concluded that for the lead-tin systems considered, convection in the mushy zone is not significant below the upper 20 percent of the dendritic zone, if al all.

  17. Effects of brine migration on waste storage systems. Final report

    International Nuclear Information System (INIS)

    Gaffney, E.S.; Nickell, R.E.

    1979-01-01

    Processes which can lead to mobilization of brine adjacent to spent fuel or nuclear waste canisters and some of the thermomechanical consequences have been investigated. Velocities as high as 4 x 10 -7 m s -1 (13 m y -1 ) are calculated at the salt/canister boundary. As much as 40 liters of pure NaCl brine could accumulate around each canister during a 10-year storage period. Accumulations of bittern brines would probably be less, in the range of 2 to 5 liters. With 0.5% water, NaCl brine accumulation over a 10-year storage cycle around a spent fuel canister producing 0.6 kW of heat is expected to be less than 1 liter for centimeter-size inclusions and less than 0.5 liter for millimeter-size inclusions. For bittern brines, about 25 years would be required to accumulate 0.4 liter. The most serious mechanical consequence of brine migration would be the increased mobility of the waste canister due to pressure solution. In pressure solution enhanced deformation, the existence of a thin film of fluid either between grains or between media (such as between a canister and the salt) provides a pathway by which the salt can be redistributed leading to a marked increase in strain rates in wet rock relative to dry rock. In salt, intergranular water will probably form discontinuous layers rather than films so that they would dominate pressure solution. A mathematical model of pressure solution indicates that pressure solution will not lead to appreciable canister motions except possibly in fine grained rocks (less than 10 -4 m). In fine grained salts, details of the contact surface between the canister and the salt bed may lead to large pressure solution motions. A numerical model indicates that heat transfer in the brine layer surrounding a spent fuel canister is not conduction dominated but has a significant convective component

  18. Systems study 'Alternative Entsorgung'. Final report. Technical annex 10

    International Nuclear Information System (INIS)

    Hartje, B.; Kronschnabel, H.; Mueller, W.F.W.

    1984-01-01

    There is an investigation whether accessibility can be produced to fuel elements stored in a salt mine. All solutions of the problem were followed up until the technically best one was found. Two conditions must be fulfilled for access to the final storage barrel: - There must be a climate which is suitable for people. The Mining Order is the basis for this. - The pit building must be fixed, in the convergence in the salt mine should not lead to it becoming impossible to reach part of the mine. Due to heat-producing waste, rock temperatures are caused in the salt mine, in which mining is no longer possible. Building on the idea of cooling the whole final storage area using concentric sections, the amount of heat to be removal was first estimated. Cooling of the whole final storage area proved to be technically unjustifiable and uninteresting at present. (orig./HP) [de

  19. Scale analysis of convective clouds

    Directory of Open Access Journals (Sweden)

    Micha Gryschka

    2008-12-01

    Full Text Available The size distribution of cumulus clouds due to shallow and deep convection is analyzed using satellite pictures, LES model results and data from the German rain radar network. The size distributions found can be described by simple power laws as has also been proposed for other cloud data in the literature. As the observed precipitation at ground stations is finally determined by cloud numbers in an area and individual sizes and rain rates of single clouds, the cloud size distributions might be used for developing empirical precipitation forecasts or for validating results from cloud resolving models being introduced to routine weather forecasts.

  20. Observing Convective Aggregation

    Science.gov (United States)

    Holloway, Christopher E.; Wing, Allison A.; Bony, Sandrine; Muller, Caroline; Masunaga, Hirohiko; L'Ecuyer, Tristan S.; Turner, David D.; Zuidema, Paquita

    2017-11-01

    Convective self-aggregation, the spontaneous organization of initially scattered convection into isolated convective clusters despite spatially homogeneous boundary conditions and forcing, was first recognized and studied in idealized numerical simulations. While there is a rich history of observational work on convective clustering and organization, there have been only a few studies that have analyzed observations to look specifically for processes related to self-aggregation in models. Here we review observational work in both of these categories and motivate the need for more of this work. We acknowledge that self-aggregation may appear to be far-removed from observed convective organization in terms of time scales, initial conditions, initiation processes, and mean state extremes, but we argue that these differences vary greatly across the diverse range of model simulations in the literature and that these comparisons are already offering important insights into real tropical phenomena. Some preliminary new findings are presented, including results showing that a self-aggregation simulation with square geometry has too broad distribution of humidity and is too dry in the driest regions when compared with radiosonde records from Nauru, while an elongated channel simulation has realistic representations of atmospheric humidity and its variability. We discuss recent work increasing our understanding of how organized convection and climate change may interact, and how model discrepancies related to this question are prompting interest in observational comparisons. We also propose possible future directions for observational work related to convective aggregation, including novel satellite approaches and a ground-based observational network.

  1. Deriving Global Convection Maps From SuperDARN Measurements

    Science.gov (United States)

    Gjerloev, J. W.; Waters, C. L.; Barnes, R. J.

    2018-04-01

    A new statistical modeling technique for determining the global ionospheric convection is described. The principal component regression (PCR)-based technique is based on Super Dual Auroral Radar Network (SuperDARN) observations and is an advanced version of the PCR technique that Waters et al. (https//:doi.org.10.1002/2015JA021596) used for the SuperMAG data. While SuperMAG ground magnetic field perturbations are vector measurements, SuperDARN provides line-of-sight measurements of the ionospheric convection flow. Each line-of-sight flow has a known azimuth (or direction), which must be converted into the actual vector flow. However, the component perpendicular to the azimuth direction is unknown. Our method uses historical data from the SuperDARN database and PCR to determine a fill-in model convection distribution for any given universal time. The fill-in data process is driven by a list of state descriptors (magnetic indices and the solar zenith angle). The final solution is then derived from a spherical cap harmonic fit to the SuperDARN measurements and the fill-in model. When compared with the standard SuperDARN fill-in model, we find that our fill-in model provides improved solutions, and the final solutions are in better agreement with the SuperDARN measurements. Our solutions are far less dynamic than the standard SuperDARN solutions, which we interpret as being due to a lack of magnetosphere-ionosphere inertia and communication delays in the standard SuperDARN technique while it is inherently included in our approach. Rather, we argue that the magnetosphere-ionosphere system has inertia that prevents the global convection from changing abruptly in response to an interplanetary magnetic field change.

  2. Free convective heat transfer with hall effects, heat absorption and chemical reaction over an accelerated moving plate in a rotating system

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, S.M., E-mail: hussain.modassir@yahoo.com [Department of Mathematics, OP Jindal University, Raigarh 496109 (India); Jain, J., E-mail: jj.28481@gmail.com [Department of Mathematics, OP Jindal University, Raigarh 496109 (India); Seth, G.S., E-mail: gsseth_ism@yahoo.com [Department of Applied Mathematics, Indian School of Mines, Dhanbad 826004 (India); Rashidi, M.M., E-mail: mm_rashidi@yahoo.com [Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management System, Tongji University, Shanghai 201804 (China)

    2017-01-15

    The unsteady MHD free convective heat and mass transfer flow of an electrically conducting, viscous and incompressible fluid over an accelerated moving vertical plate in the presence of heat absorption and chemical reaction with ramped temperature and ramped surface concentration through a porous medium in a rotating system is studied, taking Hall effects into account. The governing equations are solved analytically with the help of Laplace transform technique. The unified closed-form expressions are obtained for fluid velocity, fluid temperature, species concentration, skin friction, Nusselt number and Sherwood numbers. The effects of various parameters on fluid velocity, fluid temperature and species concentration are discussed by graphs whereas numerical values of skin friction, Nusselt and Sherwood numbers are presented in tabular form for different values of pertinent flow parameters. The numerical results are also compared with free convective flow near ramped temperature plate with ramped surface concentration with the corresponding flow near isothermal plate with uniform surface concentration. - Highlights: • Magnetic field, Hall current, rotation and chemical reaction play vital role on flow field. • Hall current tends to accelerate secondary fluid velocity in the boundary layer region. • Rotation tends to retard primary fluid velocity throughout the boundary layer region. • Rotation and chemical reaction tend to enhance primary skin friction. • Solutal buoyancy force and permeability of medium reduce primary skin friction.

  3. The ATF [Advanced Toroidal Facility] Data Management System: [Final report

    International Nuclear Information System (INIS)

    Kannan, K.L.; Baylor, L.R.

    1987-01-01

    The Advanced Toroidal Facility (ATF) Data Management System (DMG) is a VAX-based software system that provides unified data access for ATF data acquisition and analysis. The system was designed with user accessibility, software maintainability, and extensibility as primary goals. This paper describes the layered architecture of the system design, the system implementation, use, and the data file structure. 3 refs., 1 fig

  4. Final Report. Novel Behavior of Ferromagnet/Superconductor Hybrid Systems

    Energy Technology Data Exchange (ETDEWEB)

    Birge, Norman [Michigan State Univ., East Lansing, MI (United States)

    2016-09-26

    Final report for grant DE-FG02-06ER46341. This work has produced a most convincing experimental demonstration that spin-triplet supercurrent can appear in Josephson junctions containing ferromagnetic materials, even when the superconducting electrodes are conventional, spin-singlet superconductors.

  5. Final Report. Novel Behavior of Ferromagnet/Superconductor Hybrid Systems

    International Nuclear Information System (INIS)

    Birge, Norman

    2016-01-01

    Final report for grant DE-FG02-06ER46341. This work has produced a most convincing experimental demonstration that spin-triplet supercurrent can appear in Josephson junctions containing ferromagnetic materials, even when the superconducting electrodes are conventional, spin-singlet superconductors.

  6. Modeling convection-diffusion-reaction systems for microfluidic molecular communications with surface-based receivers in Internet of Bio-Nano Things.

    Directory of Open Access Journals (Sweden)

    Murat Kuscu

    Full Text Available We consider a microfluidic molecular communication (MC system, where the concentration-encoded molecular messages are transported via fluid flow-induced convection and diffusion, and detected by a surface-based MC receiver with ligand receptors placed at the bottom of the microfluidic channel. The overall system is a convection-diffusion-reaction system that can only be solved by numerical methods, e.g., finite element analysis (FEA. However, analytical models are key for the information and communication technology (ICT, as they enable an optimisation framework to develop advanced communication techniques, such as optimum detection methods and reliable transmission schemes. In this direction, we develop an analytical model to approximate the expected time course of bound receptor concentration, i.e., the received signal used to decode the transmitted messages. The model obviates the need for computationally expensive numerical methods by capturing the nonlinearities caused by laminar flow resulting in parabolic velocity profile, and finite number of ligand receptors leading to receiver saturation. The model also captures the effects of reactive surface depletion layer resulting from the mass transport limitations and moving reaction boundary originated from the passage of finite-duration molecular concentration pulse over the receiver surface. Based on the proposed model, we derive closed form analytical expressions that approximate the received pulse width, pulse delay and pulse amplitude, which can be used to optimize the system from an ICT perspective. We evaluate the accuracy of the proposed model by comparing model-based analytical results to the numerical results obtained by solving the exact system model with COMSOL Multiphysics.

  7. Modeling convection-diffusion-reaction systems for microfluidic molecular communications with surface-based receivers in Internet of Bio-Nano Things.

    Science.gov (United States)

    Kuscu, Murat; Akan, Ozgur B

    2018-01-01

    We consider a microfluidic molecular communication (MC) system, where the concentration-encoded molecular messages are transported via fluid flow-induced convection and diffusion, and detected by a surface-based MC receiver with ligand receptors placed at the bottom of the microfluidic channel. The overall system is a convection-diffusion-reaction system that can only be solved by numerical methods, e.g., finite element analysis (FEA). However, analytical models are key for the information and communication technology (ICT), as they enable an optimisation framework to develop advanced communication techniques, such as optimum detection methods and reliable transmission schemes. In this direction, we develop an analytical model to approximate the expected time course of bound receptor concentration, i.e., the received signal used to decode the transmitted messages. The model obviates the need for computationally expensive numerical methods by capturing the nonlinearities caused by laminar flow resulting in parabolic velocity profile, and finite number of ligand receptors leading to receiver saturation. The model also captures the effects of reactive surface depletion layer resulting from the mass transport limitations and moving reaction boundary originated from the passage of finite-duration molecular concentration pulse over the receiver surface. Based on the proposed model, we derive closed form analytical expressions that approximate the received pulse width, pulse delay and pulse amplitude, which can be used to optimize the system from an ICT perspective. We evaluate the accuracy of the proposed model by comparing model-based analytical results to the numerical results obtained by solving the exact system model with COMSOL Multiphysics.

  8. Theories for convection in stellar atmospheres

    International Nuclear Information System (INIS)

    Nordlund, Aa.

    1976-02-01

    A discussion of the fundamental differences between laboratory convection in a stellar atmosphere is presented. The shortcomings of laterally homogeneous model atmospheres are analysed, and the extent to which these shortcoming are avoided in the two-component representation is discussed. Finally a qualitative discussion on the scaling properties of stellar granulation is presented. (Auth.)

  9. B-Plant Canyon Ventilation Control System Description; FINAL

    International Nuclear Information System (INIS)

    MCDANIEL, K.S.

    1999-01-01

    Project W-059 installed a new B Plant Canyon Ventilation System. Monitoring and control of the system is implemented by the Canyon Ventilation Control System (CVCS). This document describes the CVCS system components which include a Programmable Logic Controller (PLC) coupled with an Operator Interface Unit (OIU) and application software. This document also includes an Alarm Index specifying the setpoints and technical basis for system analog and digital alarms

  10. NNWSI project information management system concepts evaluation report. Final report

    International Nuclear Information System (INIS)

    1986-08-01

    This report is intended as a first step in developing detailed information management system specifications for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. The current state of information management at the NNWSI Project level is investigated and an information management system (IMS) is proposed. The IMS as it relates to aspects of Project and records management is discussed. Information management concepts and prospective IMS system components are investigated. Concepts and system components include: indexing, searching, retrieval, data base management system technology, computers, storage media, computer-assisted retrieval (CAR) of microfilm, electronic imaging-based systems, optical character recognition, and communications. Performance criteria and desirable system attributes applicable to the IMS are discussed. Six conceptual system approaches capable of satisfying the performance criteria are defined. System approaches include: fully centralized microfilm system based on CAR retrieval (Approach 1), partially distributed microfilm system based on CAR retrieval (Approach 2), fully distributed microfilm system based on CAR retrieval (Approach 3), fully centralized optical disk system based on electronic image and full-text retrieval (Approach 4), partially distributed optical system based on electron image and full-text retrieval (Approach 5), and fully distributed optical disk system based on electronic image and full-text retrieval (Approach 6). Technical and cost considerations associated with the six conceptual approaches are evaluated. Technical evaluation results indicate Approach 4 is the best conceptual approach, and cost evaluation results show no significant differences among approaches. On the basis of the evaluation, Approach 4 is recommended

  11. 3D CFD simulations to study the effect of inclination of condenser tube on natural convection and thermal stratification in a passive decay heat removal system

    Energy Technology Data Exchange (ETDEWEB)

    Minocha, Nitin [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Joshi, Jyeshtharaj B., E-mail: jbjoshi@gmail.com [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400 094 (India); Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Nayak, Arun K. [Reactor Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Vijayan, Pallippattu K., E-mail: vijayanp@barc.gov.in [Reactor Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India)

    2016-08-15

    Highlights: • Investigation of three-dimensional natural convection and thermal stratification inside large water pool. • Effect of inclination (α) of condenser tube on fluid flow and heat transfer. • The heat transfer was found to be maximum for α = 90° and minimum for α = 15°. • Laminar-turbulent natural convection and heat transfer in the presence of longitudinal vortices. - Abstract: Many advanced nuclear reactors adopt methodologies of passive safety systems based on natural forces such as gravity. In one of such system, the decay heat generated from a reactor is removed by isolation condenser (ICs) submerged in a large water pool called the Gravity Driven Water Pool (GDWP). The objective of the present study was to design an IC for the passive decay heat removal system (PDHRS) for advanced nuclear reactor. First, the effect of inclination of IC tube on three dimensional temperature and flow fields was investigated inside a pilot scale (10 L) GDWP. Further, the knowledge of these fields has been used for the quantification of heat transfer and thermal stratification phenomenon. In a next step, the knowledge gained from the pilot scale GDWP has been extended to design an IC for real size GDWP (∼10,000 m{sup 3}). Single phase CFD simulation using open source CFD code [OpenFOAM-2.2] was performed for different tube inclination angles (α) (w.r.t. to vertical direction) in the range 0° ⩽ α ⩽ 90°. The results indicate that the heat transfer coefficient increases with increase in tube inclination angle. The heat transfer was found to be maximum for α = 90° and minimum for α = 15°. This behavior is due to the interaction between the primary flow (due to pressure gradient) and secondary flow (due to buoyancy force). The primary flow enhanced the fluid sliding motion at the tube top whereas the secondary flow resulted in enhancement in fluid motion along the circumference of tube. As the angle of inclination (α) of the tube was increased, the

  12. Convective heat transfer

    CERN Document Server

    Kakac, Sadik; Pramuanjaroenkij, Anchasa

    2014-01-01

    Intended for readers who have taken a basic heat transfer course and have a basic knowledge of thermodynamics, heat transfer, fluid mechanics, and differential equations, Convective Heat Transfer, Third Edition provides an overview of phenomenological convective heat transfer. This book combines applications of engineering with the basic concepts of convection. It offers a clear and balanced presentation of essential topics using both traditional and numerical methods. The text addresses emerging science and technology matters, and highlights biomedical applications and energy technologies. What’s New in the Third Edition: Includes updated chapters and two new chapters on heat transfer in microchannels and heat transfer with nanofluids Expands problem sets and introduces new correlations and solved examples Provides more coverage of numerical/computer methods The third edition details the new research areas of heat transfer in microchannels and the enhancement of convective heat transfer with nanofluids....

  13. Drainage facility management system : final report, June 2009.

    Science.gov (United States)

    2009-06-01

    This research project identified requirements for a drainage facility management system for the Oregon Department of Transportation. It also estimated the personnel resources needed to collect the inventory to populate such a system with data. A tota...

  14. Power plant system assessment. Final report. SP-100 Program

    International Nuclear Information System (INIS)

    Anderson, R.V.; Atkins, D.F.; Bost, D.S.

    1983-01-01

    The purpose of this assessment was to provide system-level insights into 100-kWe-class space reactor electric systems. Using these insights, Rockwell was to select and perform conceptual design studies on a ''most attractive'' system that met the preliminary design goals and requirements of the SP-100 Program. About 4 of the 6 months were used in the selection process. The remaining 2 months were used for the system conceptual design studies. Rockwell completed these studies at the end of FY 1983. This report summarizes the results of the power plant system assessment and describes our choice for the most attractive system - the Rockwell SR-100G System (Space Reactor, 100 kWe, Growth) - a lithium-cooled UN-fueled fast reactor/Brayton turboelectric converter system

  15. Organic Rankine Kilowatt Isotope Power System. Final phase I report

    International Nuclear Information System (INIS)

    1978-01-01

    On 1 August 1975 under Department of Energy Contract EN-77-C-02-4299, Sundstrand Energy Systems commenced development of a Kilowatt Isotope Power System (KIPS) directed toward satisfying the higher power requirements of satellites of the 1980s and beyond. The KIPS is a 238 PuO 2 fueled organic Rankine cycle turbine power system which will provide design output power in the range of 500 to 2000 W/sub (e)/ with a minimum of system changes. The principal objectives of the Phase 1 development effort were to: conceptually design a flight system; design a Ground Demonstration System (GDS) that is prototypic of the flight system in order to prove the feasibility of the flight system design; fabricate and assemble the GDS; and performance and endurance test the GDS using electric heaters in lieu of the isotope heat source. Results of the work performed under the Phase 1 contract to 1 July 1978 are presented

  16. Interfacing system isolation experience review. Final report, August 1991

    International Nuclear Information System (INIS)

    1991-08-01

    A light water reactor power plant has auxiliary systems interconnected with the reactor coolant system that are not designed for reactor operating pressure. These principally include the shutdown heat removal systems and various emergency core cooling injection systems. There are multiple isolation valves that prevent rector vessel pressure from causing overpressurization in low pressure interfacing systems. Combinations of hardware failures or operational errors are necessary to expose these systems to overpressurization. This experience review provides insights regarding the risk that an auxiliary system might become over pressurized from the reactor system. While analyses show that for the pressures involved the probability of auxiliary system failure is low, the auxiliary system conceivably might fail outside of containment while the plant is at power. Such a potential event has come to be called an interfacing system loss of coolant accident (ISLOCA). This report provides a compilation of occurrences where valve leakage, valve failure, or valve mispositioning played a role in the ability to maintain interfacing system isolation. Seventeen U.S. BWR events, twenty three U.S. PWR events and one foreign event are discussed in the report. Eleven of the U.S. BWR events and ten U.S. PWR events are judged to relate directly to the so-called ISLOCA event in that they fulfilled one or more of the failures necessary to cause an ISLOCA. (author)

  17. Understanding and controlling plasmon-induced convection

    Science.gov (United States)

    Roxworthy, Brian J.; Bhuiya, Abdul M.; Vanka, Surya P.; Toussaint, Kimani C.

    2014-01-01

    The heat generation and fluid convection induced by plasmonic nanostructures is attractive for optofluidic applications. However, previously published theoretical studies predict only nanometre per second fluid velocities that are inadequate for microscale mass transport. Here we show both theoretically and experimentally that an array of plasmonic nanoantennas coupled to an optically absorptive indium-tin-oxide (ITO) substrate can generate >micrometre per second fluid convection. Crucially, the ITO distributes thermal energy created by the nanoantennas generating an order of magnitude increase in convection velocities compared with nanoantennas on a SiO2 base layer. In addition, the plasmonic array alters absorption in the ITO, causing a deviation from Beer-Lambert absorption that results in an optimum ITO thickness for a given system. This work elucidates the role of convection in plasmonic optical trapping and particle assembly, and opens up new avenues for controlling fluid and mass transport on the micro- and nanoscale.

  18. Solar system installation at Louisville, Kentucky (final report)

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-07

    A contract was awarded in June 1976 for the installation of a solar space heating and domestic hot water system at 2400 Watteroon Trail, Louisville, Kentucky. The overall philosophy used was to install both a liquid and a hot air system retrofitted to the existing office and combined warehouse building. The 1080 sq ft office space is heated first and excess heat is dumped into the warehouse. The two systems offered a unique opportunity to measure the performance and compare results of both air and liquid at one site. The two systems are described in detail and information on the data acquisition system is included.

  19. Oxygen isotope study of the Long Valley magma system, California: isotope thermometry and convection in large silicic magma bodies

    Science.gov (United States)

    Bindeman, Ilya; Valley, John

    2002-07-01

    Products of voluminous pyroclastic eruptions with eruptive draw-down of several kilometers provide a snap-shot view of batholith-scale magma chambers, and quench pre-eruptive isotopic fractionations (i.e., temperatures) between minerals. We report analyses of oxygen isotope ratio in individual quartz phenocrysts and concentrates of magnetite, pyroxene, and zircon from individual pumice clasts of ignimbrite and fall units of caldera-forming 0.76 Ma Bishop Tuff (BT), pre-caldera Glass Mountain (2.1-0.78 Ma), and post-caldera rhyolites (0.65-0.04 Ma) to characterize the long-lived, batholith-scale magma chamber beneath Long Valley Caldera in California. Values of δ18O show a subtle 1‰ decrease from the oldest Glass Mountain lavas to the youngest post-caldera rhyolites. Older Glass Mountain lavas exhibit larger ( 1‰) variability of δ18O(quartz). The youngest domes of Glass Mountain are similar to BT in δ18O(quartz) values and reflect convective homogenization during formation of BT magma chamber surrounded by extremely heterogeneous country rocks (ranging from 2 to +29‰). Oxygen isotope thermometry of BT confirms a temperature gradient between "Late" (815 °C) and "Early" (715 °C) BT. The δ18O(quartz) values of "Early" and "Late" BT are +8.33 and 8.21‰, consistent with a constant δ18O(melt)=7.8+/-0.1‰ and 100 °C temperature difference. Zircon-melt saturation equilibria gives a similar temperature range. Values of δ18O(quartz) for different stratigraphic units of BT, and in pumice clasts ranging in pre-eruptive depths from 6 to 11 km (based on melt inclusions), and document vertical and lateral homogeneity of δ18O(melt). Worldwide, five other large-volume rhyolites, Lava Creek, Lower Bandelier, Fish Canyon, Cerro Galan, and Toba, exhibit equal δ18O(melt) values of earlier and later erupted portions in each of the these climactic caldera-forming eruptions. We interpret the large-scale δ18O homogeneity of BT and other large magma chambers as evidence

  20. Technology verification phase. Dynamic isotope power system. Final report

    International Nuclear Information System (INIS)

    Halsey, D.G.

    1982-01-01

    The Phase I requirements of the Kilowatt Isotope Power System (KIPS) program were to make a detailed Flight System Conceptual Design (FSCD) for an isotope fueled organic Rankine cycle power system and to build and test a Ground Demonstration System (GDS) which simulated as closely as possible the operational characteristics of the FSCD. The activities and results of Phase II, the Technology Verification Phase, of the program are reported. The objectives of this phase were to increase system efficiency to 18.1% by component development, to demonstrate system reliability by a 5000 h endurance test and to update the flight system design. During Phase II, system performance was improved from 15.1% to 16.6%, an endurance test of 2000 h was performed while the flight design analysis was limited to a study of the General Purpose Heat Source, a study of the regenerator manufacturing technique and analysis of the hardness of the system to a laser threat. It was concluded from these tests that the GDS is basically prototypic of a flight design; all components necessary for satisfactory operation were demonstrated successfully at the system level; over 11,000 total h of operation without any component failure attested to the inherent reliability of this type of system; and some further development is required, specifically in the area of performance

  1. Technology verification phase. Dynamic isotope power system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Halsey, D.G.

    1982-03-10

    The Phase I requirements of the Kilowatt Isotope Power System (KIPS) program were to make a detailed Flight System Conceptual Design (FSCD) for an isotope fueled organic Rankine cycle power system and to build and test a Ground Demonstration System (GDS) which simulated as closely as possible the operational characteristics of the FSCD. The activities and results of Phase II, the Technology Verification Phase, of the program are reported. The objectives of this phase were to increase system efficiency to 18.1% by component development, to demonstrate system reliability by a 5000 h endurance test and to update the flight system design. During Phase II, system performance was improved from 15.1% to 16.6%, an endurance test of 2000 h was performed while the flight design analysis was limited to a study of the General Purpose Heat Source, a study of the regenerator manufacturing technique and analysis of the hardness of the system to a laser threat. It was concluded from these tests that the GDS is basically prototypic of a flight design; all components necessary for satisfactory operation were demonstrated successfully at the system level; over 11,000 total h of operation without any component failure attested to the inherent reliability of this type of system; and some further development is required, specifically in the area of performance. (LCL)

  2. Mesoscale convective system surface pressure anomalies responsible for meteotsunamis along the U.S. East Coast on June 13th, 2013.

    Science.gov (United States)

    Wertman, Christina A; Yablonsky, Richard M; Shen, Yang; Merrill, John; Kincaid, Christopher R; Pockalny, Robert A

    2014-11-25

    Two destructive high-frequency sea level oscillation events occurred on June 13th, 2013 along the U.S. East Coast. Seafloor processes can be dismissed as the sources, as no concurrent offshore earthquakes or landslides were detected. Here, we present evidence that these tsunami-like events were generated by atmospheric mesoscale convective systems (MCSs) propagating from inland to offshore. The USArray Transportable Array inland and NOAA tide gauges along the coast recorded the pressure anomalies associated with the MCSs. Once offshore, the pressure anomalies generated shallow water waves, which were amplified by the resonance between the water column and atmospheric forcing. Analysis of the tidal data reveals that these waves reflected off the continental shelf break and reached the coast, where bathymetry and coastal geometry contributed to their hazard potential. This study demonstrates that monitoring MCS pressure anomalies in the interior of the U.S. provides important observations for early warnings of MCS-generated tsunamis.

  3. Flash propagation and inferred charge structure relative to radar-observed ice alignment signatures in a small Florida mesoscale convective system

    Science.gov (United States)

    Biggerstaff, Michael I.; Zounes, Zackery; Addison Alford, A.; Carrie, Gordon D.; Pilkey, John T.; Uman, Martin A.; Jordan, Douglas M.

    2017-08-01

    A series of vertical cross sections taken through a small mesoscale convective system observed over Florida by the dual-polarimetric SMART radar were combined with VHF radiation source locations from a lightning mapping array (LMA) to examine the lightning channel propagation paths relative to the radar-observed ice alignment signatures associated with regions of negative specific differential phase (KDP). Additionally, charge layers inferred from analysis of LMA sources were related to the ice alignment signature. It was found that intracloud flashes initiated near the upper zero-KDP boundary surrounding the negative KDP region. The zero-KDP boundary also delineated the propagation path of the lightning channel with the negative leaders following the upper boundary and positive leaders following the lower boundary. Very few LMA sources were found in the negative KDP region. We conclude that rapid dual-polarimetric radar observations can diagnose strong electric fields and may help identify surrounding regions of charge.

  4. GO evaluation of a PWR spray system. Final report

    International Nuclear Information System (INIS)

    Long, W.T.

    1975-08-01

    GO is a reliability analysis methodology developed over the years from 1960 to the present by Kaman Sciences Corporation, Colorado Springs, Colorado. In this report the GO methodology is presented and its application demonstrated by performing a reliability analysis of a conceptual PWR Containment Spray System. Certain numerical results obtained are compared with those of a prior fault tree analysis of the same system as documented in the 11 January 1973 draft report, A Fault Tree Evaluation of a PWR Spray System

  5. Fuzzy logic controllers and chaotic natural convection loops

    International Nuclear Information System (INIS)

    Theler, German

    2007-01-01

    The study of natural circulation loops is a subject of special concern for the engineering design of advanced nuclear reactors, as natural convection provides an efficient and completely passive heat removal system. However, under certain circumstances thermal-fluid-dynamical instabilities may appear, threatening the reactor safety as a whole.On the other hand, fuzzy logic controllers provide an ideal framework to approach highly non-linear control problems. In the present work, we develop a software-based fuzzy logic controller and study its application to chaotic natural convection loops.We numerically analyse the linguistic control of the loop known as the Welander problem in such conditions that, if the controller were not present, the circulation flow would be non-periodic unstable.We also design a Taka gi-Sugeno fuzzy controller based on a fuzzy model of a natural convection loop with a toroidal geometry, in order to stabilize a Lorenz-chaotic behaviour.Finally, we show experimental results obtained in a rectangular natural circulation loop [es

  6. Ensemble cloud-resolving modelling of a historic back-building mesoscale convective system over Liguria: the San Fruttuoso case of 1915

    Science.gov (United States)

    Parodi, Antonio; Ferraris, Luca; Gallus, William; Maugeri, Maurizio; Molini, Luca; Siccardi, Franco; Boni, Giorgio

    2017-05-01

    Highly localized and persistent back-building mesoscale convective systems represent one of the most dangerous flash-flood-producing storms in the north-western Mediterranean area. Substantial warming of the Mediterranean Sea in recent decades raises concerns over possible increases in frequency or intensity of these types of events as increased atmospheric temperatures generally support increases in water vapour content. However, analyses of the historical record do not provide a univocal answer, but these are likely affected by a lack of detailed observations for older events. In the present study, 20th Century Reanalysis Project initial and boundary condition data in ensemble mode are used to address the feasibility of performing cloud-resolving simulations with 1 km horizontal grid spacing of a historic extreme event that occurred over Liguria: the San Fruttuoso case of 1915. The proposed approach focuses on the ensemble Weather Research and Forecasting (WRF) model runs that show strong convergence over the Ligurian Sea (17 out of 56 members) as these runs are the ones most likely to best simulate the event. It is found that these WRF runs generally do show wind and precipitation fields that are consistent with the occurrence of highly localized and persistent back-building mesoscale convective systems, although precipitation peak amounts are underestimated. Systematic small north-westward position errors with regard to the heaviest rain and strongest convergence areas imply that the reanalysis members may not be adequately representing the amount of cool air over the Po Plain outflowing into the Ligurian Sea through the Apennines gap. Regarding the role of historical data sources, this study shows that in addition to reanalysis products, unconventional data, such as historical meteorological bulletins, newspapers, and even photographs, can be very valuable sources of knowledge in the reconstruction of past extreme events.

  7. Numerical study on turbulent forced convective heat transfer using nanofluids TiO2 in an automotive cooling system

    Directory of Open Access Journals (Sweden)

    Adnan M. Hussein

    2017-03-01

    Full Text Available The limited thermal properties of liquids have led to the addition of solid nanoparticles to liquids in many industrial applications. In this paper, the friction factor and forced convection heat transfer of TiO2 nanoparticles dispersed in water in a car radiator was numerically determined. Four different nanofluid volume concentrations (1%, 2%, 3% and 4% were used, and the resulting thermal properties were evaluated. The Reynolds number and inlet temperature ranged from 10000 to 100000 and from 60 to 90 °C, respectively. The results showed that the friction factor decreases as the Reynolds number increases and increases as the volume concentration increases. Additionally, the Nusselt number increases as the Reynolds number and volume concentration of the nanofluid increases. The TiO2 nanofluid at low concentrations can enhance the heat transfer efficiency up to 20% compared with that of pure water. There was good agreement among the CFD analysis and experimental data available in the literature.

  8. Evaluation of Instructional Systems RUPS and TABA. Final Report.

    Science.gov (United States)

    O'Neill, Phillip M.

    An investigation was conducted to determine the extent of dissemination of the Research Utilizing Problem Solving (Rups) and Development of Higher Level Thinking Abilities (TABA) instructional systems developed by the Northwest Regional Laboratory (NWREL), the degree of conformity between the RUPS and TABA systems as developed and as used in the…

  9. Airborne Electro-Optical Sensor Simulation System. Final Report.

    Science.gov (United States)

    Hayworth, Don

    The total system capability, including all the special purpose and general purpose hardware comprising the Airborne Electro-Optical Sensor Simulation (AEOSS) System, is described. The functional relationship between hardware portions is described together with interface to the software portion of the computer image generation. Supporting rationale…

  10. OLAP: A Fast, Easy, Affordable Executive Information System--Finally!

    Science.gov (United States)

    Stewart, Henry M.

    1995-01-01

    The University of Rochester's experience with online analytical processing (OLAP), part of its executive information system, is reported. The server, a multiuser, local area network (LAN)-based database loaded from legacy systems or a data warehouse, can rapidly manipulate and display data, and allows quick creation and changing of analytical…

  11. Economic incentives to wind systems commercialization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lotker, M.; Shaw, Jr, R. W.; Adolfson, W. F.; Bernardi, R. P.; Davidoff, P. H.; Eckhart, M. T.; Gunwaldsen, D. S.; Mettam, P. J.; Narayanan, P.; Sillin, J. O.

    1978-08-01

    This assessment of Economic Incentives to Wind Systems Commercialization is an analysis of the quantitative and qualitative impacts of a variety of Government funded economic incentives on Wind Energy Conversion Systems (WECS). The purpose of this study is to achieve better understanding of the relationship between implementation of specific economic incentives for WECS, and the factors surrounding WECS commercial introduction.

  12. Mirror fusion test facility magnet system. Final design report

    International Nuclear Information System (INIS)

    Henning, C.D.; Hodges, A.J.; VanSant, J.H.; Dalder, E.N.; Hinkle, R.E.; Horvath, J.A.; Scanlan, R.M.; Shimer, D.W.; Baldi, R.W.; Tatro, R.E.

    1980-01-01

    Information is given on each of the following topics: (1) magnet description, (2) superconducting manufacture, (3) mechanical behavior of conductor winding, (4) coil winding, (5) thermal analysis, (6) cryogenic system, (7) power supply system, (8) structural analysis, (9) structural finite element analysis refinement, (10) structural case fault analysis, and (11) structural metallurgy

  13. HVAC systems and nuclear plant safety. Final report, May 1992

    International Nuclear Information System (INIS)

    1992-05-01

    The primary objective of this study was to provide perspective on the overall risk impact of heating, ventilating, and air conditioning (HVAC) system problems. Industry experience with HVAC system problems is documented and analyzed. In addition, the results of 10 plant-specific probabilistic risk assessments (PRA) were reviewed to determine the contribution of HVAC systems to the risk of core damage. The PRAs included in this review cover a broad range of plant types and operating conditions. The review found that the impact of HVAC systems on risk is plant specific. These results exhibit a broad range of frequencies for HVAC contribution to risk, and the percentage of total core damage due to HVAC problems also had a wide variability. Plant-specific differences in design, environment, operation, and maintenance are the primary factors in determining the risk contribution of HVAC systems. (author)

  14. Developing maintainability for fusion power systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, H.S.; Mantz, H.C.; Curtis, C.T.; Buchheit, R.J.; Green, W.M.; Zuckerman, D.S.

    1979-11-01

    The overall purpose of the study is to identify design features of fusion power reactors which contribute to the achievement of high levels of maintainability. Previous phases evaluated several commercial tokamak reactor design concepts. This final phase compares the maintainability of a tandem mirror reactor (TMR) commercial conceptual design with the most maintainable tokamak concept selected from earlier work. A series of maintainability design guidelines and desirable TMR design features are defined. The effects of scheduled and unscheduled maintenance for most of the reactor subsystems are defined. The comparison of the TMR and tokamak reactor maintenance costs and availabilities show that both reactors have similar costs for scheduled maintenance at 19.4 and 20.8 million dollars annually and similar scheduled downtime availability impacts, achieving approximate availabilities of 79% at optimized maintenance intervals and cost of electricity.

  15. Developing maintainability for fusion power systems. Final report

    International Nuclear Information System (INIS)

    Zahn, H.S.; Mantz, H.C.; Curtis, C.T.; Buchheit, R.J.; Green, W.M.; Zuckerman, D.S.

    1979-11-01

    The overall purpose of the study is to identify design features of fusion power reactors which contribute to the achievement of high levels of maintainability. Previous phases evaluated several commercial tokamak reactor design concepts. This final phase compares the maintainability of a tandem mirror reactor (TMR) commercial conceptual design with the most maintainable tokamak concept selected from earlier work. A series of maintainability design guidelines and desirable TMR design features are defined. The effects of scheduled and unscheduled maintenance for most of the reactor subsystems are defined. The comparison of the TMR and tokamak reactor maintenance costs and availabilities show that both reactors have similar costs for scheduled maintenance at 19.4 and 20.8 million dollars annually and similar scheduled downtime availability impacts, achieving approximate availabilities of 79% at optimized maintenance intervals and cost of electricity

  16. System study of alternative waste management techniques: Final report

    International Nuclear Information System (INIS)

    1986-01-01

    This report summarizes the important results achieved in conjunction with the Research and Development Priority ''Alternative Waste Management Techniques'' sponsored by the Federal Ministry of Research and Technology from 1981 to 1984. The subject of these studies was solely ''direct disposal'' of spent fuel elements. For this purpose a reference concept was selected from a variety of possible processes and engineered in detailed form by firms in the nuclear industry. Those who worked on the engineering concepts consider this waste management method technically feasible. Several disposal casks have been fabricated. The basic licensability of direct disposal can be evaluated on the basis of the documentation developed by the companies. The direct disposal method was compared with the ''integrated waste management concept'' using reference fuel cycles with respect to the following criteria: radiological safety and nuclear material safeguards and, in addition, economic and energy-policy aspects. It was found that with respect to radiological safety, including the long-term safety of the final repository, there are no significant differences between the two fuel cycles with and without reprocessing. With respect to the nuclear material safeguards of a final repository containing spent fuel elements, there are still a number of unanswered questions. From an economic standpoint, direct disposal will be more economical in the foreseeable future than integrated waste management. Quantification of the effects of one or the other waste management method on the national economy is not necessarily possible. Reprocessing is supported primarily by technological and energy-policy considerations. On the basis of the results, the conclusion is reached that reprocessing should be pursued further, but that at the same time direct disposal should be developed to the point of practical maturity

  17. Evaluation of the Plant-Craig stochastic convection scheme (v2.0) in the ensemble forecasting system MOGREPS-R (24 km) based on the Unified Model (v7.3)

    Science.gov (United States)

    Keane, Richard J.; Plant, Robert S.; Tennant, Warren J.

    2016-05-01

    The Plant-Craig stochastic convection parameterization (version 2.0) is implemented in the Met Office Regional Ensemble Prediction System (MOGREPS-R) and is assessed in comparison with the standard convection scheme with a simple stochastic scheme only, from random parameter variation. A set of 34 ensemble forecasts, each with 24 members, is considered, over the month of July 2009. Deterministic and probabilistic measures of the precipitation forecasts are assessed. The Plant-Craig parameterization is found to improve probabilistic forecast measures, particularly the results for lower precipitation thresholds. The impact on deterministic forecasts at the grid scale is neutral, although the Plant-Craig scheme does deliver improvements when forecasts are made over larger areas. The improvements found are greater in conditions of relatively weak synoptic forcing, for which convective precipitation is likely to be less predictable.

  18. Nuclear Power Safety Reporting System. Final evaluation results

    International Nuclear Information System (INIS)

    Finlayson, F.C.; Newton, R.D.

    1986-02-01

    This document presents the results of a study conducted by the US Nuclear Regulatory Commission of an unobtrusive, voluntary, anonymous third-party managed, nonpunitive human factors data gathering system (the Nuclear power Safety Reporting System - NPSRS) for the nuclear electric power production industry. The data to be gathered by the NPSRS are intended for use in identifying and quantifying the factors that contribute to the occurrence of significant safety incidents involving humans in nuclear power plants. The NPSRS has been designed to encourage participation in the System through guarantees of reporter anonymity provided by a third-party organization that would be responsible for NPSRS management. As additional motivation to reporters for contributing data to the NPSRS, conditional waivers of NRC disciplinary action would be provided to individuals. These conditional waivers of immunity would apply to potential violations of NRC regulations that might be disclosed through reports submitted to the System about inadvertent, noncriminal incidents in nuclear plants. This document summarizes the overall results of the study of the NPSRS concept. In it, a functional description of the NPSRS is presented together with a review and assessment of potential problem areas that might be met if the System were implemented. Conclusions and recommendations resulting from the study are also presented. A companion volume (NUREG/CR-4133, Nuclear Power Safety Reporting System: Implementation and Operational Specifications'') presented in detail the elements, requirements, forms, and procedures for implementing and operating the System. 13 refs

  19. The impact of reflectivity correction and accounting for raindrop size distribution variability to improve precipitation estimation by weather radar for an extreme low-land mesoscale convective system

    Science.gov (United States)

    Hazenberg, Pieter; Leijnse, Hidde; Uijlenhoet, Remko

    2014-11-01

    Between 25 and 27 August 2010 a long-duration mesoscale convective system was observed above the Netherlands, locally giving rise to rainfall accumulations exceeding 150 mm. Correctly measuring the amount of precipitation during such an extreme event is important, both from a hydrological and meteorological perspective. Unfortunately, the operational weather radar measurements were affected by multiple sources of error and only 30% of the precipitation observed by rain gauges was estimated. Such an underestimation of heavy rainfall, albeit generally less strong than in this extreme case, is typical for operational weather radar in The Netherlands. In general weather radar measurement errors can be subdivided into two groups: (1) errors affecting the volumetric reflectivity measurements (e.g. ground clutter, radar calibration, vertical profile of reflectivity) and (2) errors resulting from variations in the raindrop size distribution that in turn result in incorrect rainfall intensity and attenuation estimates from observed reflectivity measurements. A stepwise procedure to correct for the first group of errors leads to large improvements in the quality of the estimated precipitation, increasing the radar rainfall accumulations to about 65% of those observed by gauges. To correct for the second group of errors, a coherent method is presented linking the parameters of the radar reflectivity-rain rate (Z - R) and radar reflectivity-specific attenuation (Z - k) relationships to the normalized drop size distribution (DSD). Two different procedures were applied. First, normalized DSD parameters for the whole event and for each precipitation type separately (convective, stratiform and undefined) were obtained using local disdrometer observations. Second, 10,000 randomly generated plausible normalized drop size distributions were used for rainfall estimation, to evaluate whether this Monte Carlo method would improve the quality of weather radar rainfall products. Using the

  20. Intergovernmental Advanced Stationary PEM Fuel Cell System Demonstration Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rich Chartrand

    2011-08-31

    A program to complete the design, construction and demonstration of a PEMFC system fuelled by Ethanol, LPG or NG for telecom applications was initiated in October 2007. Early in the program the economics for Ethanol were shown to be unfeasible and permission was given by DOE to focus on LPG only. The design and construction of a prototype unit was completed in Jun 2009 using commercially available PEM FC stack from Ballard Power Systems. During the course of testing, the high pressure drop of the stack was shown to be problematic in terms of control and stability of the reformer. Also, due to the power requirements for air compression the overall efficiency of the system was shown to be lower than a similar system using internally developed low pressure drop FC stack. In Q3 2009, the decision was made to change to the Plug power stack and a second prototype was built and tested. Overall net efficiency was shown to be 31.5% at 3 kW output. Total output of the system is 6 kW. Using the new stack hardware, material cost reduction of 63% was achieved over the previous Alpha design. During a November 2009 review meeting Plug Power proposed and was granted permission, to demonstrate the new, commercial version of Plug Power's telecom system at CERL. As this product was also being tested as part of a DOE Topic 7A program, this part of the program was transferred to the Topic 7A program. In Q32008, the scope of work of this program was expanded to include a National Grid demonstration project of a micro-CHP system using hightemperature PEM technology. The Gensys Blue system was cleared for unattended operation, grid connection, and power generation in Aug 2009 at Union College in NY state. The system continues to operate providing power and heat to Beuth House. The system is being continually evaluated and improvements to hardware and controls will be implemented as more is learned about the system's operation. The program is instrumental in improving the

  1. Automated personnel data base system specifications, Task V. Final report

    International Nuclear Information System (INIS)

    Bartley, H.J.; Bocast, A.K.; Deppner, F.O.; Harrison, O.J.; Kraas, I.W.

    1978-11-01

    The full title of this study is 'Development of Qualification Requirements, Training Programs, Career Plans, and Methodologies for Effective Management and Training of Inspection and Enforcement Personnel.' Task V required the development of an automated personnel data base system for NRC/IE. This system is identified as the NRC/IE Personnel, Assignment, Qualifications, and Training System (PAQTS). This Task V report provides the documentation for PAQTS including the Functional Requirements Document (FRD), the Data Requirements Document (DRD), the Hardware and Software Capabilities Assessment, and the Detailed Implementation Schedule. Specific recommendations to facilitate implementation of PAQTS are also included

  2. Laser fusion systems design study. Final technical report

    International Nuclear Information System (INIS)

    1975-06-01

    This study investigated: (1) the formulation and evaluation of an alignment system to accomplish pointing, focusing, centering and translation for the 20-arm SHIVA laser, (2) the formulation and evaluation of concepts for the correction of static phase distortions introduced by the accumulated optical elements in the laser chains, (3) the formulation and evaluation of concepts for the correction of optical path length differences between the arms of the SHIVA system, and (4) the conceptual design of appropriate control system hardware. (U.S.)

  3. Improved Controls for Fusion RF Systems. Final technical report

    International Nuclear Information System (INIS)

    Casey, Jeffrey A.

    2011-01-01

    We have addressed the specific requirements for the integrated systems controlling an array of klystrons used for Lower Hybrid Current Drive (LHCD). The immediate goal for our design was to modernize the transmitter protection system (TPS) for LHCD on the Alcator C-Mod tokamak at the MIT Plasma Science and Fusion Center (MIT-PSFC). Working with the Alcator C-Mod team, we have upgraded the design of these controls to retrofit for improvements in performance and safety, as well as to facilitate the upcoming expansion from 12 to 16 klystrons. The longer range goals to generalize the designs in such a way that they will be of benefit to other programs within the international fusion effort was met by designing a system which was flexible enough to address all the MIT system requirements, and modular enough to adapt to a large variety of other requirements with minimal reconfiguration

  4. Improved Controls for Fusion RF Systems. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Jeffrey A. [Rockfield Research Inc., Las Vegas, NV (United States)

    2011-11-08

    We have addressed the specific requirements for the integrated systems controlling an array of klystrons used for Lower Hybrid Current Drive (LHCD). The immediate goal for our design was to modernize the transmitter protection system (TPS) for LHCD on the Alcator C-Mod tokamak at the MIT Plasma Science and Fusion Center (MIT-PSFC). Working with the Alcator C-Mod team, we have upgraded the design of these controls to retrofit for improvements in performance and safety, as well as to facilitate the upcoming expansion from 12 to 16 klystrons. The longer range goals to generalize the designs in such a way that they will be of benefit to other programs within the international fusion effort was met by designing a system which was flexible enough to address all the MIT system requirements, and modular enough to adapt to a large variety of other requirements with minimal reconfiguration.

  5. Repair systems for deteriorated bridge piles : final report.

    Science.gov (United States)

    2017-04-01

    The objective of this research project is to develop a durable repair system for deteriorated steel bridge piles that : can be implemented without the need for dewatering. A rigorous survey of the relevant practice nationwide was : conducted to infor...

  6. Culvert information management system : demonstration project, final report, August 2009.

    Science.gov (United States)

    2009-08-01

    The overall objective of the research was to develop a pilot scale Culvert Information Management System (CIMS) that will : comply with both requirements stipulated by the Governmental Accounting Standards Board (GASB-34) and new federal : storm wate...

  7. Louisiana DOTD maintenance budget allocation system: final report.

    Science.gov (United States)

    2002-11-01

    This project developed a computer system to assist Louisiana Department of Transportation and Development (LA DOTD) maintenance managers in the preparation of zero-based, needs-driven annual budget plans for routine maintenance. This includes pavemen...

  8. Intelligent transportation systems business plan for Kentucky : final report.

    Science.gov (United States)

    2001-09-01

    This report presents a Business Plan for Intelligent Transportation Systems (ITS) in Kentucky. The purpose of the Business Plan is to define ITS projects that are planned for implementation from 2002 through 2007. The list of projects contained withi...

  9. Static Scale Conversion Weigh-In-Motion System; FINAL

    International Nuclear Information System (INIS)

    Beshears, D.L.

    2001-01-01

    In support of the Air Mobility Battle Lab (AMBL), the Defense Advanced Research Projects Agency (DARPA) Advanced Logistics Program and the U. S. Transportation Command (USTRANSCOM), the ultimate objective of this project is to develop and demonstrate a full-scale prototype static scale conversion weigh-in-motion/Profilometry (SSC-WIM/P) system to measure and record dimensional and weight information for the Department of Defense (DoD) equipment and cargo. The Oak Ridge National Laboratory (ORNL), along with the AMBL, and Intercomp, Inc. have developed a long-range plan for developing a dual-use system which can be used as a standard static scale or an accurate weigh-in-motion system. AMBL will work to define requirements for additional activities with U.S. Transportation Command, Air Mobility Command, and the Joint Warfighting Battle Lab for both the SSC-WIM/P and a portable Weigh-in-Motion System for individual units. The funding goal is to fully fund the development of two prototype test articles (a SSC-WIM kit, and a laser profilometer) and have at least one fully operational system by the early 2002 timeframe. The objective of this portion of the project will be to develop a SSC-WIM system, which at a later date can be fully integrated with a profilometry system; to fully characterize DOD wheeled vehicles and cargo (individual axle weights, total vehicle weight, center of balance, height, width and length measurements). The program will be completed in phases with the initial AMBL/DARPA funding being used to initiate the efforts while AMBL/USTC obtains funding to complete the first generation system effort. At the completion of an initial effort, the interface hardware and the data acquisition/analysis hardware will be developed, fabricated, and system principles and basic functionality evaluated, tested, and demonstrated. Additional funding, when made available, will allow the successful completion of a first generation prototype system. This effort will be

  10. Solid oxide fuel cell systems development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    The main objective in this project has been to develop a generic and dynamic tool for SOFC systems simulation and development. Developing integrated fuel cell systems is very expensive and therefore having the right tools to reduce the development cost and time to market for products becomes an important feature. The tools developed in this project cover a wide range of needs in Dantherm Power, R and D, and can be divided into 3 categories: 1. Component selection modeling; to define component specification requirements and selection of suppliers. 2. Application simulation model built from scratch, which can simulate the interface between customer demand and system output and show operation behavior for different control settings. 3. System operation strategy optimization with respect to operation cost and customer benefits. a. Allows to see how system size, in terms of electricity and heat output, and operation strategy influences a specific business case. b. Gives a clear overview of how a different property, in the system, affects the economics (e.g. lifetime, electrical and thermal efficiency, fuel cost sensitivity, country of deployment etc.). The main idea behind the structure of the tool being separated into 3 layers is to be able to service different requirements, from changing stakeholders. One of the major findings in this project has been related to thermal integration between the existing installation in a private household and the fuel cell system. For a normal family requiring 4500 kWh of electricity a year, along with the possibility of only running the system during the heating season (winter), the heat storage demand is only 210kWh of heat with an approximate value of Dkr 160,- in extra gas consumption. In this case, it would be much more cost effective to dump the heat, in the house, and save the expense of adding heat storage to the system. This operation strategy is only valid in Denmark for the time being, since the feed-In-Tariff allows for a

  11. Solar heating system installed at Jackson, Tennessee. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-01

    The solar energy heating system installed at the Coca-Cola Bottling Works in Jackson, Tennessee is described. The system consists of 9480 square feet of Owens-Illinois evacuated tubular solar collectors with attached specular cylindrical reflectors and will provide space heating for the 70,000 square foot production building in the winter, and hot water for the bottle washing equipment the remainder of the year. Component specifications and engineering drawings are included. (WHK)

  12. Center for Advanced Biofuel Systems (CABS) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kutchan, Toni M. [Donald Danforth Plant Science Center, St. Louis, MO (United States)

    2015-12-02

    One of the great challenges facing current and future generations is how to meet growing energy demands in an environmentally sustainable manner. Renewable energy sources, including wind, geothermal, solar, hydroelectric, and biofuel energy systems, are rapidly being developed as sustainable alternatives to fossil fuels. Biofuels are particularly attractive to the U.S., given its vast agricultural resources. The first generation of biofuel systems was based on fermentation of sugars to produce ethanol, typically from food crops. Subsequent generations of biofuel systems, including those included in the CABS project, will build upon the experiences learned from those early research results and will have improved production efficiencies, reduced environmental impacts and decreased reliance on food crops. Thermodynamic models predict that the next generations of biofuel systems will yield three- to five-fold more recoverable energy products. To address the technological challenges necessary to develop enhanced biofuel systems, greater understanding of the non-equilibrium processes involved in solar energy conversion and the channeling of reduced carbon into biofuel products must be developed. The objective of the proposed Center for Advanced Biofuel Systems (CABS) was to increase the thermodynamic and kinetic efficiency of select plant- and algal-based fuel production systems using rational metabolic engineering approaches grounded in modern systems biology. The overall strategy was to increase the efficiency of solar energy conversion into oils and other specialty biofuel components by channeling metabolic flux toward products using advanced catalysts and sensible design:1) employing novel protein catalysts that increase the thermodynamic and kinetic efficiencies of photosynthesis and oil biosynthesis; 2) engineering metabolic networks to enhance acetyl-CoA production and its channeling towards lipid synthesis; and 3) engineering new metabolic networks for the

  13. Final Report for the Virtual Reliability Realization System LDRD

    Energy Technology Data Exchange (ETDEWEB)

    DELLIN, THEODORE A.; HENDERSON, CHRISTOPHER L.; O' TOOLE, EDWARD J.

    2000-12-01

    Current approaches to reliability are not adequate to keep pace with the need for faster, better and cheaper products and systems. This is especially true in high consequence of failure applications. The original proposal for the LDRD was to look at this challenge and see if there was a new paradigm that could make reliability predictions, along with a quantitative estimate of the risk in that prediction, in a way that was faster, better and cheaper. Such an approach would be based on the underlying science models that are the backbone of reliability predictions. The new paradigm would be implemented in two software tools: the Virtual Reliability Realization System (VRRS) and the Reliability Expert System (REX). The three-year LDRD was funded at a reduced level for the first year ($120K vs. $250K) and not renewed. Because of the reduced funding, we concentrated on the initial development of the expertise system. We developed an interactive semiconductor calculation tool needed for reliability analyses. We also were able to generate a basic functional system using Microsoft Siteserver Commerce Edition and Microsoft Sequel Server. The base system has the capability to store Office documents from multiple authors, and has the ability to track and charge for usage. The full outline of the knowledge model has been incorporated as well as examples of various types of content.

  14. Project on Alternative Systems Study - PASS. Final report

    International Nuclear Information System (INIS)

    1992-10-01

    Alternative repository systems for deep disposal of spent fuel and different types of canisters are studied regarding technical aspects in Project on Alternative System Study (PASS). The objective is to present a ranking of repository systems as well as of canister types for each system. The studies and compared systems are: KBS-3, Medium Long Tunnels (MLH), Long tunnels (VLH) and Deep Boreholes (VDH). For KBS-3 and MLH five canister types are compared (copper/steel, copper/lead, copper (HIP), steel/lead and steel), for VLH two types (copper/steel and steel), and for VDH three types (titanium/concrete with non-consolidated fuel assemblies, titanium/concrete with consolidated assemblies and copper (HIP) with non-consolidated assemblies). The comparison is separated into three sub-comparisons (Technology, Long-term performance and safety, and Costs), which eventually are merged into one ranking. With respect to canister alternatives the result is that the copper/steel canister is ranked first for KBS-3, MLH and VLH, while the titanium/concrete canister is ranked first for VDH (non-consolidated as well as consolidated assemblies. With these canister alternatives the merged ranking of repository systems results in placing KBS-3 slightly in front of MLH. VLH comes thereafter and VDH last. (32 refs.)

  15. Tides in differentially rotating convective envelopes. II. The tidal coupling

    International Nuclear Information System (INIS)

    Scharlemann, E.T.

    1982-01-01

    The tidal coupling between a star with an extended, differentially rotating convective envelope, and its companion in a close binary system, is calculated from the tidal velocity field derived in Paper I. The derived coupling torque can be tested using observations of RS Canum Venaticorum systems, for which a photometric wave in the light curve provides an accurate stellar rotation rate, and for which observed orbital period changes require the stars in the systems to be coupled. The coupling torque is sufficient to explain the nearly synchronous rotation of the active star in RS CVn systems, despite the observed orbital period changes, but may not be able to explain the extreme tightness of the coupling implied by the very long periods for the migration of the photometric waves in the systems. This conclusion depends on the origin of the orbital period changes, but not on the nature of the wave or the wave migration. When the coupling torque vanishes, a specific latitude at the surface of the convective star will exactly corotate with the binary system: this corotation latitude is calculated. Finally, it is shown that the additional viscous terms introduced by tides should not suppress differential rotation in binary systems with RS Cvn parameters

  16. Smart Infrared Inspection System Field Operational Test Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Siekmann, Adam [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL; Lascurain, Mary Beth [ORNL

    2011-06-01

    The Smart InfraRed Inspection System (SIRIS) is a tool designed to assist inspectors in determining which vehicles passing through the SIRIS system are in need of further inspection by measuring the thermal data from the wheel components. As a vehicle enters the system, infrared cameras on the road measure temperatures of the brakes, tires, and wheel bearings on both wheel ends of commercial motor vehicles (CMVs) in motion. This thermal data is then presented to enforcement personal inside of the inspection station on a user friendly interface. Vehicles that are suspected to have a violation are automatically alerted to the enforcement staff. The main goal of the SIRIS field operational test (FOT) was to collect data to evaluate the performance of the prototype system and determine the viability of such a system being used for commercial motor vehicle enforcement. From March 2010 to September 2010, ORNL facilitated the SIRIS FOT at the Greene County Inspection Station (IS) in Greeneville, Tennessee. During the course of the FOT, 413 CMVs were given a North American Standard (NAS) Level-1 inspection. Of those 413 CMVs, 384 were subjected to a SIRIS screening. A total of 36 (9.38%) of the vehicles were flagged by SIRIS as having one or more thermal issues; with brakes issues making up 33 (91.67%) of those. Of the 36 vehicles flagged as having thermal issues, 31 (86.11%) were found to have a violation and 30 (83.33%) of those vehicles were placed out-of-service (OOS). Overall the enforcement personnel who have used SIRIS for screening purposes have had positive feedback on the potential of SIRIS. With improvements in detection algorithms and stability, the system will be beneficial to the CMV enforcement community and increase overall trooper productivity by accurately identifying a higher percentage of CMVs to be placed OOS with minimal error. No future evaluation of SIRIS has been deemed necessary and specifications for a production system will soon be drafted.

  17. Green Lighting. Energy-efficient integrated lighting systems - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Linhart, F.; Scartezzini, J.-L.

    2009-10-15

    The objective of the Green Lighting project was to develop a High Performance Integrated Lighting System, based on advanced technologies for day- and electric lighting, achieving a Lighting Power Density (LPD) that does not exceed 3 W/m{sup 2}. The project has revealed that Anidolic Daylighting Systems (ADS) are an ideal basis for High Performance Integrated Lighting Systems. Not only are they able to provide adequate illumination (i.e. sufficiently high illuminance) in office rooms during large fractions of normal office hours, under various sky conditions and over the entire year, but they are also highly appreciated by office occupants at the condition that glare control mechanisms are available. Complementary electric lighting is, however, still necessary to back up the ADS at times when there is insufficient daylight flux available. It was shown during this project, that the most interesting trade-offs between energy-efficiency and visual comfort are obtained by using a combination of ceiling-mounted directly emitting luminaires with very high optical efficiencies for ambient lighting and portable desk lamps for temporary task lighting. The most appropriate lamps for the ceiling-mounted luminaires are currently highly efficient fluorescent tubes, but white LED tubes can be considered a realistic option for the future. The most suitable light sources for desk lamps for temporary task lighting are Compact Fluorescent Lamps (CFLs) and white LED light bulbs. Based on the above-mentioned technologies, a High Performance Integrated Lighting System with a very low LPD has been developed over the last three years. The system has been set up in an office room of the LESO solar experimental building located on the EPFL campus; it has been tested intensively during a Post-Occupancy Evaluation (POE) study involving twenty human subjects. This study has revealed that the subjects' performance and subjective visual comfort was improved by the new system, compared to

  18. Systems study 'Alternative Entsorgung'. Final report. Technical annex 7

    International Nuclear Information System (INIS)

    Engelmann, H.J.

    1984-10-01

    A radiation protection concept was worked out for final storage of spent fuel elements. It contains the areas of instrumentation and equipment with the necessary devices and measuring equipment for monitoring emission and the room air, personnel dosimetry, measuring contamination, local dose rate measurements and division into radiation protection areas. The barrel incoming inspection is described. The work for determining the radiological load of the operating staff and the environment for correct and incorrect operation is also described. The radiological load of the operating staff for correct operation was determined in the form of the collective dose with dose factors in accordance with ICRP and individual doses according to Radiation Protection Ordinance. The collective dose is 0.28 pers. Sv/a and the maximum individual dose remains below 1.0 E-2 Sv/a. The individual doses determined remain below the permitted limits of Radiation Protection Ordinance. In the context of accident analysis, it was found that no accidents occur, which load the operating staff radiologically above the permitted limits of the Radiation Protection Ordinance. A probability consideration of accidents shows that the accident risk of the operating staff is several orders of magnitude below that of the normal operating risk. (orig./HP) [de

  19. Occupancy-counter-based control system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, G.; Hoagland, L. C.; Bowman, J. K.

    1979-07-01

    Excessive mechanical ventilation of commercial and institutional buildings can result in significant waste of energy required for space heating and cooling. Ventilation rates are typically set to satisfy building design occupancy levels, in accordance with local codes, even though the building may seldom or never experience design occupancy. A method of eliminating this waste to utilize an occupancy-based ventilation control system wherein a counting device records people entering and leaving the building, to maintain a continuous record of people inventory, and to regulate mechanical ventilation control dampers to supply only that amount of ventilation air required for current occupancy levels is described. A device of this type was installed and tested in a department store in Framingham, Massachusetts and fully instrumented and operated over a 14 month period. Test results on energy usage were correlated with weather severity in order to determine the savings resulting from use of the control system. This system provided a savings of 33% in gas usage during the winter period and a savings of 23% in electricity usage during the summer period. These savings would return the installed cost of the control system in about 1 1/2 years. Projections of the performance of this system in other climatic regions (Chicago, Los Angeles, Kansas City, Miami, Minneapolis) are also presented illustrating payback periods ranging from 1/3 year in Miami to 2 2/3 years in Los Angeles. Complete details of the occupancy based ventilation control system, the test site instrumentation and data gathering procedure, the test results and their interpretation are given. (MCW)

  20. Analysis of batteries for use in photovoltaic systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Podder, A; Kapner, M

    1981-02-01

    An evaluation of 11 types of secondary batteries for energy storage in photovoltaic electric power systems is given. The evaluation was based on six specific application scenarios which were selected to represent the diverse requirements of various photovoltaic systems. Electrical load characteristics and solar insulation data were first obtained for each application scenario. A computer-based simulation program, SOLSIM, was then developed to determine optimal sizes for battery, solar array, and power conditioning systems. Projected service lives and battery costs were used to estimate life-cycle costs for each candidate battery type. The evaluation considered battery life-cycle cost, safety and health effects associated with battery operation, and reliability/maintainability. The 11 battery types were: lead-acid, nickel-zinc, nickel-iron, nickel-hydrogen, lithium-iron sulfide, calcium-iron sulfide, sodium-sulfur, zinc-chlorine, zinc-bromine, Redox, and zinc-ferricyanide. The six application scenarios were: (1) a single-family house in Denver, Colorado (photovoltaic system connected to the utility line); (2) a remote village in equatorial Africa (stand-alone power system); (3) a dairy farm in Howard County, Maryland (onsite generator for backup power); (4) a 50,000 square foot office building in Washington, DC (onsite generator backup); (5) a community in central Arizona with a population of 10,000 (battery to be used for dedicated energy storage for a utility grid-connected photovoltaic power plant); and (6) a military field telephone office with a constant 300 W load (trailer-mounted auxiliary generator backup). Recommendations for a research and development program on battery energy storage for photovoltaic applications are given, and a discussion of electrical interfacing problems for utility line-connected photovoltaic power systems is included. (WHK)

  1. ADVANCED TURBINE SYSTEM CONCEPTUAL DESIGN AND PRODUCT DEVELOPMENT - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht H. Mayer

    2000-07-15

    Asea Brown Boveri (ABB) has completed its technology based program. The results developed under Work Breakdown Structure (WBS) 8, concentrated on technology development and demonstration have been partially implemented in newer turbine designs. A significant improvement in heat rate and power output has been demonstrated. ABB will use the knowledge gained to further improve the efficiency of its Advanced Cycle System, which has been developed and introduced into the marked out side ABB's Advanced Turbine System (ATS) activities. The technology will lead to a power plant design that meets the ATS performance goals of over 60% plant efficiency, decreased electricity costs to consumers and lowest emissions.

  2. Design and synthesis of reactive separation systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, M.F.

    1992-12-31

    During the last decade there has been a rapid upturn in interest in reactive distillation. The chemical process industry recognizes the favorable economics of carrying out reaction simultaneously with distillation for certain classes of reacting systems, and many new processes have been built based on this technology. Interest is also increasing by academics and software vendors. Systematic design methods for reactive distillation systems have only recently begun to emerge. In this report we survey the available design techniques and point out the contributions made by our group at the University of Massachusetts.

  3. ADVANCED TURBINE SYSTEM CONCEPTUAL DESIGN AND PRODUCT DEVELOPMENT; FINAL

    International Nuclear Information System (INIS)

    Albrecht H. Mayer

    2000-01-01

    Asea Brown Boveri (ABB) has completed its technology based program. The results developed under Work Breakdown Structure (WBS) 8, concentrated on technology development and demonstration have been partially implemented in newer turbine designs. A significant improvement in heat rate and power output has been demonstrated. ABB will use the knowledge gained to further improve the efficiency of its Advanced Cycle System, which has been developed and introduced into the marked out side ABB's Advanced Turbine System (ATS) activities. The technology will lead to a power plant design that meets the ATS performance goals of over 60% plant efficiency, decreased electricity costs to consumers and lowest emissions

  4. Operations-oriented performance measures for freeway management systems : final report.

    Science.gov (United States)

    2008-12-01

    This report describes the second and final year activities of the project titled Using Operations-Oriented Performance Measures to Support Freeway Management Systems. Work activities included developing a prototype system architecture for testi...

  5. Simulating deep convection with a shallow convection scheme

    Directory of Open Access Journals (Sweden)

    C. Hohenegger

    2011-10-01

    Full Text Available Convective processes profoundly affect the global water and energy balance of our planet but remain a challenge for global climate modeling. Here we develop and investigate the suitability of a unified convection scheme, capable of handling both shallow and deep convection, to simulate cases of tropical oceanic convection, mid-latitude continental convection, and maritime shallow convection. To that aim, we employ large-eddy simulations (LES as a benchmark to test and refine a unified convection scheme implemented in the Single-column Community Atmosphere Model (SCAM. Our approach is motivated by previous cloud-resolving modeling studies, which have documented the gradual transition between shallow and deep convection and its possible importance for the simulated precipitation diurnal cycle.

    Analysis of the LES reveals that differences between shallow and deep convection, regarding cloud-base properties as well as entrainment/detrainment rates, can be related to the evaporation of precipitation. Parameterizing such effects and accordingly modifying the University of Washington shallow convection scheme, it is found that the new unified scheme can represent both shallow and deep convection as well as tropical and mid-latitude continental convection. Compared to the default SCAM version, the new scheme especially improves relative humidity, cloud cover and mass flux profiles. The new unified scheme also removes the well-known too early onset and peak of convective precipitation over mid-latitude continental areas.

  6. The Workplace Literacy System Project (WLS). Final Performance Report.

    Science.gov (United States)

    Poulton, Bruce R.

    The Workplace Literacy System Project (WLS) prepared interactive CD-ROM discs containing about 50 hours of instruction and drill in basic skills presented within the context of the textile/apparel manufacturing industry. The project was conducted at a Sara Lee knit products plant in North Carolina. During the project, literacy task analyses were…

  7. Schedule for Rating Disabilities; the Endocrine System. Final rule.

    Science.gov (United States)

    2017-11-02

    This document amends the Department of Veterans Affairs (VA) Schedule for Rating Disabilities (VASRD) by revising the portion of the Schedule that addresses endocrine conditions and disorders of the endocrine system. The effect of this action is to ensure that the VASRD uses current medical terminology and to provide detailed and updated criteria for evaluation of endocrine disorders.

  8. Safeguards systems concepts for nuclear material transportation. Final report

    International Nuclear Information System (INIS)

    Baldonado, O.C.; Kevany, M.; Rodney, D.; Pitts, D.; Mazur, M.

    1977-09-01

    The report describes the development of system concepts for the safeguarding of special strategic nuclear materials (SNM) against malevolent adversary action during the interfacility transport of the SNM. The methodology used includes techniques for defining, classifying, and analyzing adversary action sequences; defining safeguards system components; assessing the vulnerability of various safeguards systems and their component parts to the potential adversary action sequences, and conceptualizing system design requirements. The method of analysis is based primarily on a comparison of adversary actions with safeguards measures, to estimate vulnerability. Because of the paucity of the data available for assessing vulnerability, the Delphi approach was used to generate data: values were estimated in a structured exercise by a panel of experts in the safeguards and terrorist fields. It is concluded that the probability of successful attack against a truck/escort convoy manned by well-trained, well-armed personnel is low enough to discourage all but the strongest adversaries. Secrecy of operations and careful screening of personnel are very important. No reliance should be placed on current capabilities of local law enforcement agencies. The recommendation of the study is the use of road transport in the near future and air transport at a later time when the number of shipments reaches a level to justify it, and when present safety problems are resolved

  9. Design analysis of supplemental heating systems. Final report

    International Nuclear Information System (INIS)

    1981-09-01

    The first objective of the study was to formulate an R and D plan for tokamak supplemental heating based upon an evaluation and the potential of each heating technique. The second objective was to develop conceptual designs for reactor level heating systems. The two techniques selected for the second studies were icrh and negative beams

  10. Communications and control for electric power systems: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kirkham, H.

    1998-04-01

    This report is a summary of some of the work done on the Communications and Control project, with particular emphasis on the achievements during the years 1986--1996. During those years, the project moved away from concern with dispersed storage and generation and its impact on power system operation (the team was responsible for studies in this area, and for making a power system simulator that included DSG), and became involved in more concrete work aimed at applying high-tech solutions to problems of power system communications and control. This report covers work done at JPL on the following topics: (1) the measurement of electric and magnetic fields, both ac and dc; (2) the use of optical power to supply low-power electronics; (3) the design of a fault-tolerant communication system designed for distribution automation; and (4) a digital phase locked loop that allows the use of low-power transmitting electronics to recreate a good-quality signal at the receiver. In a report of this kind, only the results and highlights of the work are described.

  11. Survey of system responsibility in the Nordic countries. Final report

    International Nuclear Information System (INIS)

    2005-02-01

    In September 2004 the Nordic Council of Ministers asked Nordel to perform some tasks and present the results to the Council on 1 March 2005. One of the tasks is to survey how system responsibility is defined and executed in the different Nordic countries. According to the Nordic Council of Ministers, the survey shall illuminate similarities and differences between the countries and assess the reasons for the differences. Nordel is asked to present a joint view system responsibility in the Nordic countries. Among other things, the responsibility for the system operators and the participants in the market shall be defined. The definition shall also include the distribution of costs between costs for network business and costs for business in competition. This shall be done in a way that creates a common platform for the further harmonisation work and continuous positive development of the Nordic electricity market. It is also important to identify the need for changes in e.g. legislation and guidelines in the different countries as a consequence of an implementation of a common definition in the Nordic countries. Areas to be included in the task are among others, balance settlement, security of supply, congestion management and system services. (BA)

  12. Safe Active Scanning for Energy Delivery Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Helms, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Salazar, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Scheibel, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Engels, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reiger, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-30

    The Department of Energy’s Cybersecurity for Energy Delivery Systems Program has funded Safe(r) Active Scanning for Energy Delivery Systems, led by Lawrence Livermore National Laboratory, to investigate and analyze the impacts of active scanning in the operational environment of energy delivery systems. In collaboration with Pacific Northwest National Laboratory and Idaho National Laboratory, active scans across three testbeds including 38 devices were performed. This report gives a summary of the initial literature survey performed on the SASEDS project as well as industry partner interview summaries and main findings from Phase 1 of the project. Additionally, the report goes into the details of scanning techniques, methodologies for testing, testbed descriptions, and scanning results, with appendices to elaborate on the specific scans that were performed. As a result of testing, a single device out of 38 exhibited problems when actively scanned, and a reboot was required to fix it. This single failure indicates that active scanning is not likely to have a detrimental effect on the safety and resilience of energy delivery systems. We provide a path forward for future research that could enable wide adoption of active scanning and lead utilities to incorporate active scanning as part of their default network security plans to discover and rectify rogue devices, adversaries, and services that may be on the network. This increased network visibility will allow operational technology cybersecurity practitioners to improve their situational awareness of networks and their vulnerabilities.

  13. Final evaluation of advanced and current leak detection systems

    International Nuclear Information System (INIS)

    Kupperman, D.S.; Carlson, R.; Brewer, W.; Lanham, R.

    1989-01-01

    This report presents the results of a study to evaluate the adequacy of leak detection systems in light water reactors. The sources of numerous reported leaks and methods of detection have been documented. Research to advance the state of the art of acoustic leak detection is presented, and procedures for implementation are discussed

  14. Library Information System Time-Sharing (LISTS) Project. Final Report.

    Science.gov (United States)

    Black, Donald V.

    The Library Information System Time-Sharing (LISTS) experiment was based on three innovations in data processing technology: (1) the advent of computer time-sharing on third-generation machines, (2) the development of general-purpose file-management software and (3) the introduction of large, library-oriented data bases. The main body of the…

  15. Is There a Separate Visual Iconic Memory System? Final Report.

    Science.gov (United States)

    Levie, W. Howard; Levie, Diane D.

    The purpose of these studies was to provide evidence to support either the dual-coding hypothesis or the single-system hypothesis of human memory. In one experiment, college subjects were shown a mixed series of words and pictures either while simultaneously engaged in shadowing (repeating aloud) a prose passage presented via earphones or while…

  16. Automated Energy Distribution and Reliability System (AEDR): Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Buche, D. L.

    2008-07-01

    This report describes Northern Indiana Public Service Co. project efforts to develop an automated energy distribution and reliability system. The purpose of this project was to implement a database-driven GIS solution that would manage all of the company's gas, electric, and landbase objects.

  17. Comparing convective heat fluxes derived from thermodynamics to a radiative-convective model and GCMs

    Science.gov (United States)

    Dhara, Chirag; Renner, Maik; Kleidon, Axel

    2015-04-01

    The convective transport of heat and moisture plays a key role in the climate system, but the transport is typically parameterized in models. Here, we aim at the simplest possible physical representation and treat convective heat fluxes as the result of a heat engine. We combine the well-known Carnot limit of this heat engine with the energy balances of the surface-atmosphere system that describe how the temperature difference is affected by convective heat transport, yielding a maximum power limit of convection. This results in a simple analytic expression for convective strength that depends primarily on surface solar absorption. We compare this expression with an idealized grey atmosphere radiative-convective (RC) model as well as Global Circulation Model (GCM) simulations at the grid scale. We find that our simple expression as well as the RC model can explain much of the geographic variation of the GCM output, resulting in strong linear correlations among the three approaches. The RC model, however, shows a lower bias than our simple expression. We identify the use of the prescribed convective adjustment in RC-like models as the reason for the lower bias. The strength of our model lies in its ability to capture the geographic variation of convective strength with a parameter-free expression. On the other hand, the comparison with the RC model indicates a method for improving the formulation of radiative transfer in our simple approach. We also find that the latent heat fluxes compare very well among the approaches, as well as their sensitivity to surface warming. What our comparison suggests is that the strength of convection and their sensitivity in the climatic mean can be estimated relatively robustly by rather simple approaches.

  18. Design analysis of supplemental heating systems. Final report

    International Nuclear Information System (INIS)

    1981-09-01

    The main emphasis of this study is to formulate R and D program priority for the future development of the heating techniques. A secondary emphasis is to improve the present state of knowledge of reactor heating systems. The technique used to determine R and D program priority was to evaluate each technique against a set of selection criteria. The selection criteria were divided into two categories. The first category contains the criteria that are normally used to evaluate the potential of any idea to proceed into hardware development; the status of the theory; the status of the technology; system efficiency; and cost. The second category contains the criteria that have important implications for reactor level devices: susceptibility to radiation, maintainability; and critical real estate requirements

  19. Standard review plan for dry cask storage systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    The Standard Review Plan (SRP) For Dry Cask Storage Systems provides guidance to the Nuclear Regulatory Commission staff in the Spent Fuel Project Office for performing safety reviews of dry cask storage systems. The SRP is intended to ensure the quality and uniformity of the staff reviews, present a basis for the review scope, and clarification of the regulatory requirements. Part 72, Subpart B generally specifies the information needed in a license application for the independent storage of spent nuclear fuel and high level radioactive waste. Regulatory Guide 3.61 {open_quotes}Standard Format and Content for a Topical Safety Analysis Report for a Spent Fuel Dry Storage Cask{close_quotes} contains an outline of the specific information required by the staff. The SRP is divided into 14 sections which reflect the standard application format. Regulatory requirements, staff positions, industry codes and standards, acceptance criteria, and other information are discussed.

  20. Standard review plan for dry cask storage systems. Final report

    International Nuclear Information System (INIS)

    1997-01-01

    The Standard Review Plan (SRP) For Dry Cask Storage Systems provides guidance to the Nuclear Regulatory Commission staff in the Spent Fuel Project Office for performing safety reviews of dry cask storage systems. The SRP is intended to ensure the quality and uniformity of the staff reviews, present a basis for the review scope, and clarification of the regulatory requirements. Part 72, Subpart B generally specifies the information needed in a license application for the independent storage of spent nuclear fuel and high level radioactive waste. Regulatory Guide 3.61 open-quotes Standard Format and Content for a Topical Safety Analysis Report for a Spent Fuel Dry Storage Caskclose quotes contains an outline of the specific information required by the staff. The SRP is divided into 14 sections which reflect the standard application format. Regulatory requirements, staff positions, industry codes and standards, acceptance criteria, and other information are discussed

  1. Fundamental research of decision support systems: Final report

    International Nuclear Information System (INIS)

    Kurstedt, H.A. Jr.

    1986-01-01

    Through an iterative application of Decision Support Systems (DSS) apparatus and evolution of DSS concepts, we redefined DSS from a systems perspective. By focusing on successful DSS and the definition of success for the newly-defined DSS, we generated a paradigm for understanding, applying, and improving DSS. The significance of the research is that we now: (1) understand the various roles management tools play within the new DSS concept; (2) recognize the need for characterizing the domain of responsibility of a manager to obtain a successful DSS; and (3) have learned special characteristics of government agencies like Nuclear Materials (NM) to identify what features of the new DSS concept can be expected to improve performance

  2. Convection and stellar oscillations

    DEFF Research Database (Denmark)

    Aarslev, Magnus Johan

    2017-01-01

    for asteroseismology, because of the challenges inherent in modelling turbulent convection in 1D stellar models. As a result of oversimplifying the physics near the surface, theoretical calculations systematically overestimate the oscillation frequencies. This has become known as the asteroseismic surface effect. Due...... to lacking better options, this frequency difference is typically corrected for with ad-hoc formulae. The topic of this thesis is the improvement of 1D stellar convection models and the effects this has on asteroseismic properties. The source of improvements is 3D simulations of radiation...... atmospheres to replace the outer layers of stellar models. The additional turbulent pressure and asymmetrical opacity effects in the atmosphere model, compared to convection in stellar evolution models, serve to expand the atmosphere. The enlarged acoustic cavity lowers the pulsation frequencies bringing them...

  3. Active control of convection

    Energy Technology Data Exchange (ETDEWEB)

    Bau, H.H. [Univ. of Pennsylvania, Philadelphia, PA (United States)

    1995-12-31

    Using stability theory, numerical simulations, and in some instances experiments, it is demonstrated that the critical Rayleigh number for the bifurcation (1) from the no-motion (conduction) state to the motion state and (2) from time-independent convection to time-dependent, oscillatory convection in the thermal convection loop and Rayleigh-Benard problems can be significantly increased or decreased. This is accomplished through the use of a feedback controller effectuating small perturbations in the boundary data. The controller consists of sensors which detect deviations in the fluid`s temperature from the motionless, conductive values and then direct actuators to respond to these deviations in such a way as to suppress the naturally occurring flow instabilities. Actuators which modify the boundary`s temperature/heat flux are considered. The feedback controller can also be used to control flow patterns and generate complex dynamic behavior at relatively low Rayleigh numbers.

  4. Energy implications of integrated solid waste management systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Little, R.E.; McClain, G.; Becker, M.; Ligon, P.; Shapiro, K.

    1994-07-01

    This study develops estimates of energy use and recovery from managing municipal solid waste (MSW) under various collection, processing, and disposal scenarios. We estimate use and recovery -- or energy balance -- resulting from MSW management activities such as waste collection, transport, processing, and disposal, as well as indirect use and recovery linked to secondary materials manufacturing using recycled materials. In our analysis, secondary materials manufacturing displaces virgin materials manufacturing for 13 representative products. Energy implications are expressed as coefficients that measure the net energy saving (or use) of displacing products made from virgin versus recycled materials. Using data developed for the 1992 New York City Master Plan as a starting point, we apply our method to an analysis of various collection systems and 30 types of facilities to illustrate bow energy balances shift as management systems are modified. In sum, all four scenarios show a positive energy balance indicating the energy and advantage of integrated systems versus reliance on one or few technology options. That is, energy produced or saved exceeds the energy used to operate the solid waste system. The largest energy use impacts are attributable to processing, including materials separation and composting. Collection and transportation energy are relatively minor contributors. The largest two contributors to net energy savings are waste combustion and energy saved by processing recycled versus virgin materials. An accompanying spatial analysis methodology allocates energy use and recovery to New York City, New York State outside the city, the U.S., and outside the U.S. Our analytical approach is embodied in a spreadsheet model that can be used by energy and solid waste analysts to estimate impacts of management scenarios at the state and substate level.

  5. Distributed Energy Neural Network Integration System: Year One Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Regan, T.; Sinnock, H.; Davis, A.

    2003-06-01

    This report describes the work of Orion Engineering Corp. to develop a DER household controller module and demonstrate the ability of a group of these controllers to operate through an intelligent, neighborhood controller. The controllers will provide a smart, technologically advanced, simple, efficient, and economic solution for aggregating a community of small distributed generators into a larger single, virtual generator capable of selling power or other services to a utility, independent system operator (ISO), or other entity in a coordinated manner.

  6. Comprehensive Final Report for the Marine Seismic System Program

    Science.gov (United States)

    1985-08-01

    serve as a principal reference for transitioning marine seismic system techniques and results from the research and development arena to the...vM . .’ .■ .» .%■■.•. - Viaj ^."-;/-.■■ *• -’•’■■’■ ■ ■ - ■ • ■ -. . -. • ^;-■:■:-:•:> •■•."--.--.v. ’-• V ’.■ *.- ".i • ■ - ■ ■ v V

  7. Development of geothermal-well-completion systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, E.B.

    1979-01-01

    Results of a three year study concerning the completion of geothermal wells, specifically cementing, are reported. The research involved some specific tasks: (1) determination of properties an adequate geothermal well cement must possess; (2) thorough evaluation of current high temperature oilwell cementing technology in a geothermal context; (3) basic research concerning the chemical and physical behavior of cements in a geothermal environment; (4) recommendation of specific cement systems suitable for use in a geothermal well.

  8. Final Technical Report "Multiscale Simulation Algorithms for Biochemical Systems"

    Energy Technology Data Exchange (ETDEWEB)

    Petzold, Linda R.

    2012-10-25

    Biochemical systems are inherently multiscale and stochastic. In microscopic systems formed by living cells, the small numbers of reactant molecules can result in dynamical behavior that is discrete and stochastic rather than continuous and deterministic. An analysis tool that respects these dynamical characteristics is the stochastic simulation algorithm (SSA, Gillespie, 1976), a numerical simulation procedure that is essentially exact for chemical systems that are spatially homogeneous or well stirred. Despite recent improvements, as a procedure that simulates every reaction event, the SSA is necessarily inefficient for most realistic problems. There are two main reasons for this, both arising from the multiscale nature of the underlying problem: (1) stiffness, i.e. the presence of multiple timescales, the fastest of which are stable; and (2) the need to include in the simulation both species that are present in relatively small quantities and should be modeled by a discrete stochastic process, and species that are present in larger quantities and are more efficiently modeled by a deterministic differential equation (or at some scale in between). This project has focused on the development of fast and adaptive algorithms, and the fun- damental theory upon which they must be based, for the multiscale simulation of biochemical systems. Areas addressed by this project include: (1) Theoretical and practical foundations for ac- celerated discrete stochastic simulation (tau-leaping); (2) Dealing with stiffness (fast reactions) in an efficient and well-justified manner in discrete stochastic simulation; (3) Development of adaptive multiscale algorithms for spatially homogeneous discrete stochastic simulation; (4) Development of high-performance SSA algorithms.

  9. Behavior-aware decision support systems : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, Gary B.; Homer, Jack (Homer Consulting); Chenoweth, Brooke N.; Backus, George A.; Strip, David R.

    2007-11-01

    As Sandia National Laboratories serves its mission to provide support for the security-related interests of the United States, it is faced with considering the behavioral responses that drive problems, mitigate interventions, or lead to unintended consequences. The effort described here expands earlier works in using healthcare simulation to develop behavior-aware decision support systems. This report focuses on using qualitative choice techniques and enhancing two analysis models developed in a sister project.

  10. Final safety analysis report for the atmospheric protection system

    International Nuclear Information System (INIS)

    1976-06-01

    An Atmospheric Protection System (APS) has been constructed at the Idaho Chemical Processing Plant to minimize the release of radioactive particulate material to the atmosphere from nonroutine occurrences. Existing off-gas cleanup systems remove radioactive particulates to well below allowable limits for controlled areas before release to the plant stack. Previously all ventilation air from process cells was discharged to the stack without treatment. The APS provides continuous filtration of all ventilation air from process cells and backup filtration of all process off gases before they are released to the atmosphere. A safety analysis of the potential hazards associated with the APS has been completed. The review indicates that the system is capable of withstanding design basis natural phenomena including a flood, tornado, and earthquake without releasing unacceptable amounts of radioactive particulate from the filters to the environment. An in-cell explosion, fire, mechanical damage, and other postulated accident situations were investigated. From these, the design basis accident postulated for the facility is complete release of the maximum amount of radioactive particulate collected on the 104 ventilation air HEPA filters to the atmosphere via the 250-foot high stack. Even though the release of all the radioactive particulate contained on the filters is hardly credible, it would not present an unacceptable hazard to personnel on or offsite

  11. New vision solar system mission study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mondt, J.F.; Zubrin, R.M.

    1996-03-01

    The vision for the future of the planetary exploration program includes the capability to deliver {open_quotes}constellations{close_quotes} or {open_quotes}fleets{close_quotes} of microspacecraft to a planetary destination. These fleets will act in a coordinated manner to gather science data from a variety of locations on or around the target body, thus providing detailed, global coverage without requiring development of a single large, complex and costly spacecraft. Such constellations of spacecraft, coupled with advanced information processing and visualization techniques and high-rate communications, could provide the basis for development of a {open_quotes}virtual{close_quotes} {open_quotes}presence{close_quotes} in the solar system. A goal could be the near real-time delivery of planetary images and video to a wide variety of users in the general public and the science community. This will be a major step in making the solar system accessible to the public and will help make solar system exploration a part of the human experience on Earth.

  12. Active system area networks for data intensive computations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-04-01

    The goal of the Active System Area Networks (ASAN) project is to develop hardware and software technologies for the implementation of active system area networks (ASANs). The use of the term ''active'' refers to the ability of the network interfaces to perform application-specific as well as system level computations in addition to their traditional role of data transfer. This project adopts the view that the network infrastructure should be an active computational entity capable of supporting certain classes of computations that would otherwise be performed on the host CPUs. The result is a unique network-wide programming model where computations are dynamically placed within the host CPUs or the NIs depending upon the quality of service demands and network/CPU resource availability. The projects seeks to demonstrate that such an approach is a better match for data intensive network-based applications and that the advent of low-cost powerful embedded processors and configurable hardware makes such an approach economically viable and desirable.

  13. Accelerating Acceptance of Fuel Cell Backup Power Systems - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Petrecky, James; Ashley, Christopher

    2014-07-21

    Since 2001, Plug Power has installed more than 800 stationary fuel cell systems worldwide. Plug Power’s prime power systems have produced approximately 6.5 million kilowatt hours of electricity and have accumulated more than 2.5 million operating hours. Intermittent, or backup, power products have been deployed with telecommunications carriers and government and utility customers in North and South America, Europe, the United Kingdom, Japan and South Africa. Some of the largest material handling operations in North America are currently using the company’s motive power units in fuel cell-powered forklifts for their warehouses, distribution centers and manufacturing facilities. The low-temperature GenSys fuel cell system provides remote, off-grid and primary power where grid power is unreliable or nonexistent. Built reliable and designed rugged, low- temperature GenSys delivers continuous or backup power through even the most extreme conditions. Coupled with high-efficiency ratings, low-temperature GenSys reduces operating costs making it an economical solution for prime power requirements. Currently, field trials at telecommunication and industrial sites across the globe are proving the advantages of fuel cells—lower maintenance, fuel costs and emissions, as well as longer life—compared with traditional internal combustion engines.

  14. Systems Analysis of NASA Aviation Safety Program: Final Report

    Science.gov (United States)

    Jones, Sharon M.; Reveley, Mary S.; Withrow, Colleen A.; Evans, Joni K.; Barr, Lawrence; Leone, Karen

    2013-01-01

    A three-month study (February to April 2010) of the NASA Aviation Safety (AvSafe) program was conducted. This study comprised three components: (1) a statistical analysis of currently available civilian subsonic aircraft data from the National Transportation Safety Board (NTSB), the Federal Aviation Administration (FAA), and the Aviation Safety Information Analysis and Sharing (ASIAS) system to identify any significant or overlooked aviation safety issues; (2) a high-level qualitative identification of future safety risks, with an assessment of the potential impact of the NASA AvSafe research on the National Airspace System (NAS) based on these risks; and (3) a detailed, top-down analysis of the NASA AvSafe program using an established and peer-reviewed systems analysis methodology. The statistical analysis identified the top aviation "tall poles" based on NTSB accident and FAA incident data from 1997 to 2006. A separate examination of medical helicopter accidents in the United States was also conducted. Multiple external sources were used to develop a compilation of ten "tall poles" in future safety issues/risks. The top-down analysis of the AvSafe was conducted by using a modification of the Gibson methodology. Of the 17 challenging safety issues that were identified, 11 were directly addressed by the AvSafe program research portfolio.

  15. Once-through integral system (OTIS): Final report

    International Nuclear Information System (INIS)

    Gloudemans, J.R.

    1986-09-01

    A scaled experimental facility, designated the once-through integral system (OTIS), was used to acquire post-small break loss-of-coolant accident (SBLOCA) data for benchmarking system codes. OTIS was also used to investigate the application of the Abnormal Transient Operating Guidelines (ATOG) used in the Babcock and Wilcox (B and W) designed nuclear steam supply system (NSSS) during the course of an SBLOCA. OTIS was a single-loop facility with a plant to model power scale factor of 1686. OTIS maintained the key elevations, approximate component volumes, and loop flow resistances, and simulated the major component phenomena of a B and W raised-loop nuclear plant. A test matrix consisting of 15 tests divided into four categories was performed. The largest group contained 10 tests and was defined to parametrically obtain an extensive set of plant-typical experimental data for code benchmarking. Parameters such as leak size, leak location, and high-pressure injection (HPI) shut-off head were individually varied. The remaining categories were specified to study the impact of the ATOGs (2 tests), to note the effect of guard heater operation on observed phenomena (2 tests), and to provide a data set for comparison with previous test experience (1 test). A summary of the test results and a detailed discussion of Test 220100 is presented. Test 220100 was the nominal or reference test for the parametric studies. This test was performed with a scaled 10-cm 2 leak located in the cold leg suction piping

  16. NEXT GENERATION GAS TURBINE (NGGT) SYSTEMS STUDY; FINAL

    International Nuclear Information System (INIS)

    Unknown

    2001-01-01

    Building upon the 1999 AD Little Study, an expanded market analysis was performed by GE Power Systems in 2001 to quantify the potential demand for an NGGT product. This analysis concluded that improvements to the US energy situation might be best served in the near/mid term (2002-2009) by a ''Technology-Focused'' program rather than a specific ''Product-Focused'' program. Within this new program focus, GEPS performed a parametric screening study of options in the three broad candidate categories of gas turbines: aero-derivative, heavy duty, and a potential hybrid combining components of the other two categories. GEPS's goal was to determine the best candidate systems that could achieve the DOE PRDA expectations and GEPS's internal design criteria in the period specified for initial product introduction, circa 2005. Performance feasibility studies were conducted on candidate systems selected in the screening task, and critical technology areas were identified where further development would be required to meet the program goals. DOE PRDA operating parameters were found to be achievable by 2005 through evolutionary technology. As a result, the study was re-directed toward technology enhancements for interim product introductions and advanced/revolutionary technology for potential NGGT product configurations. Candidate technologies were identified, both evolutionary and revolutionary, with a potential for possible development products via growth step improvements. Benefits were analyzed from two perspectives: (1) What would be the attributes of the top candidate system assuming the relevant technologies were developed and available for an NGGT market opportunity in 2009/2010; and (2) What would be the expected level of public benefit, assuming relevant technologies were incorporated into existing new and current field products as they became available. Candidate systems incorporating these technologies were assessed as to how they could serve multiple applications

  17. Columbia River system operation review. Final environmental impact statement

    International Nuclear Information System (INIS)

    1995-11-01

    The Columbia River and its tributaries are the primary water system in the Pacific Northwest, draining some 219,000 square miles in seven states and another 39,500 square miles in British Columbia. Beginning in the 1930's, the Columbia River has been significantly modified by construction of 30 major dams on the river and its tributaries, along with dozens of non-Federal projects. Construction and subsequent operation of these water development projects have contributed to eight primary uses of the river system, including navigation, flood control, irrigation, electric power generation, fish migration, fish and wildlife habitat, recreation, and water supply and quality considerations. Increasing stress on the water development of the Columbia River and its tributaries has led primary Federal agencies to undertake intensive analysis and evaluation of the operation of these projects. These agencies are the U.S. Army Corps of Engineers and the Bureau of Reclamation, who operate the large Federal dams on the river, and the Bonneville Power Administration who sells the power generated at the dams. This review, termed the System Operation Review (SOR), has as its ultimate goal to define a strategy for future operation of the major Columbia River projects which effectively considers the needs of all river uses. This volume, Appendix D: Cultural resources appendix, Technical imput includes the following: Development of geomorphology based framework for cultural resources management, Dworshak Reservoir, Idaho; Impact profiles for SOR reservoirs; comments from the following Native American tribes: Burns Paiute Tribe; Coville Confederated Tribes; Confederated Tribes of the Warm Springs Indian Reservation; Confederated Tribes and bands of the Yakama Indian Nation (comments); Nez Perce Tribe; Coeur D'Alene Tribe; Spokane Tribe of Indians; The confederated Tribes of the Umatilla Indian Reservation

  18. Advanced radiant combustion system. Final report, September 1989--September 1996

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, J.D.; Carswell, M.G.; Long, F.S.

    1996-09-01

    Results of the Advanced Radiant Combustion System (ARCS) project are presented in this report. This work was performed by Alzeta Corporation as prime contractor under a contract to the U.S. Department of Energy Office of Industrial Technologies as part of a larger DOE program entitled Research Program for Advanced Combustion Systems. The goals of the Alzeta ARCS project were to (a) Improve the high temperature performance characteristics of porous surface ceramic fiber burners, (b) Develop an Advanced Radiant Combustion System (ARCS) that combines combustion controls with an advanced radiant burner, and (c) Demonstrate the advanced burner and controls in an industrial application. Prior to the start of this project, Alzeta had developed and commercialized a porous surface radiant burner, the Pyrocore{trademark} burner. The product had been commercially available for approximately 5 years and had achieved commercial success in a number of applications ranging from small burners for commercial cooking equipment to large burners for low temperature industrial fluid heating applications. The burner was not recommended for use in applications with process temperatures above 1000{degrees}F, which prevented the burner from being used in intermediate to high temperature processes in the chemical and petroleum refining industries. The interest in increasing the maximum use temperature of the burner was motivated in part by a desire to expand the number of applications that could use the Pyrocore product, but also because many of the fluid sensitive heating applications of interest would benefit from the distributed flux characteristic of porous surface burners. Background information on porous surface radiant burners, and a discussion of advantages that would be provided by an improved product, are presented in Section 2.

  19. Coal-fired high performance power generating system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-31

    As a result of the investigations carried out during Phase 1 of the Engineering Development of Coal-Fired High-Performance Power Generation Systems (Combustion 2000), the UTRC-led Combustion 2000 Team is recommending the development of an advanced high performance power generation system (HIPPS) whose high efficiency and minimal pollutant emissions will enable the US to use its abundant coal resources to satisfy current and future demand for electric power. The high efficiency of the power plant, which is the key to minimizing the environmental impact of coal, can only be achieved using a modern gas turbine system. Minimization of emissions can be achieved by combustor design, and advanced air pollution control devices. The commercial plant design described herein is a combined cycle using either a frame-type gas turbine or an intercooled aeroderivative with clean air as the working fluid. The air is heated by a coal-fired high temperature advanced furnace (HITAF). The best performance from the cycle is achieved by using a modern aeroderivative gas turbine, such as the intercooled FT4000. A simplified schematic is shown. In the UTRC HIPPS, the conversion efficiency for the heavy frame gas turbine version will be 47.4% (HHV) compared to the approximately 35% that is achieved in conventional coal-fired plants. This cycle is based on a gas turbine operating at turbine inlet temperatures approaching 2,500 F. Using an aeroderivative type gas turbine, efficiencies of over 49% could be realized in advanced cycle configuration (Humid Air Turbine, or HAT). Performance of these power plants is given in a table.

  20. Plutonium Finishing Plant (PFP) HVAC System Component Index; FINAL

    International Nuclear Information System (INIS)

    DICK, J.D.

    1999-01-01

    This document identities the components, design media, procedures and defines the critical characteristics of Commercial Grade Items necessary to ensure the HVAC system provides these functions. This document lists safety class (SC) and safety significant (SS) components for the Heating Ventilation Air Conditioning (HVAC) and specifies the critical characteristics for Commercial Grade Items (CGI), as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics for any one item

  1. Convective transport in tokamaks

    International Nuclear Information System (INIS)

    D'Ippolito, D.A.; Myra, J.R.; Russell, D.A.; Krasheninnikov, S.I.; Pigarov, A.Yu.; Yu, G.Q.; Xu, X.Q.; Nevins, W.M.

    2005-01-01

    Scrape-off-layer (SOL) convection in fusion experiments appears to be a universal phenomenon that can 'short-circuit' the divertor in some cases. The theory of 'blob' transport provides a simple and robust physical paradigm for studying convective transport. This paper summarizes recent advances in the theory of blob transport and its comparison with 2D and 3D computer simulations. We also discuss the common physical basis relating radial transport of blobs, pellets, and ELMs and a new blob regime that may lead to a connection between blob transport and the density limit. (author)

  2. Physics of Stellar Convection

    Science.gov (United States)

    Arnett, W. David

    2009-05-01

    We review recent progress using numerical simulations as a testbed for development of a theory of stellar convection, much as envisaged by John von Newmann. Necessary features of the theory, non-locality and fluctuations, are illustrated by computer movies. It is found that the common approximation of convection as a diffusive process presents the wrong physical picture, and improvements are suggested. New observational results discussed at the conference are gratifying in their validation of some of our theoretical ideas, especially the idea that SNIb and SNIc events are related to the explosion of massive star cores which have been stripped by mass loss and binary interactions [1

  3. Parameterizing convective organization

    Directory of Open Access Journals (Sweden)

    Brian Earle Mapes

    2011-06-01

    Full Text Available Lateral mixing parameters in buoyancy-driven deep convection schemes are among the most sensitive and important unknowns in atmosphere models. Unfortunately, there is not a true optimum value for plume mixing rate, but rather a dilemma or tradeoff: Excessive dilution of updrafts leads to unstable stratification bias in the mean state, while inadequate dilution allows deep convection to occur too easily, causing poor space and time distributions and variability. In this too-small parameter space, compromises are made based on competing metrics of model performance. We attempt to escape this “entrainment dilemma” by making bulk plume parameters (chiefly entrainment rate depend on a new prognostic variable (“organization,” org meant to reflect the rectified effects of subgrid-scale structure in meteorological fields. We test an org scheme in the Community Atmosphere Model (CAM5 with a new unified shallow-deep convection scheme (UW-ens, a 2-plume version of the University of Washington scheme. Since buoyant ascent involves natural selection, subgrid structure makes convection systematically deeper and stronger than the pure unorganized case: plumes of average (or randomly sampled air rising in the average environment. To reflect this, org is nonnegative, but we leave it dimensionless. A time scale characterizes its behavior (here ∼3 h for a 2o model. Currently its source is rain evaporation, but other sources can be added easily. We also let org be horizontally transported by advection, as a mass-weighted mean over the convecting layer. Linear coefficients link org to a plume ensemble, which it assists via: 1 plume base warmth above the mean temperature 2 plume radius enhancement (reduced mixing, and 3 increased probability of overlap in a multi-plume scheme, where interactions benefit later generations (this part has only been implemented in an offline toy column model. Since rain evaporation is a source for org, it functions as a time

  4. Mathematical models of convection

    CERN Document Server

    Andreev, Victor K; Goncharova, Olga N; Pukhnachev, Vladislav V

    2012-01-01

    Phenomena of convection are abundant in nature as well as in industry. This volume addresses the subject of convection from the point of view of both, theory and application. While the first three chapters provide a refresher on fluid dynamics and heat transfer theory, the rest of the book describes the modern developments in theory. Thus it brings the reader to the ""front"" of the modern research. This monograph provides the theoretical foundation on a topic relevant to metallurgy, ecology, meteorology, geo-and astrophysics, aerospace industry, chemistry, crystal physics, and many other fiel

  5. Convective aggregation in realistic convective-scale simulations

    OpenAIRE

    Holloway, Christopher E.

    2017-01-01

    To investigate the real-world relevance of idealized-model convective self-aggregation, five 15-day cases of real organized convection in the tropics are simulated. These include multiple simulations of each case to test sensitivities of the convective organization and mean states to interactive radiation, interactive surface fluxes, and evaporation of rain. These simulations are compared to self-aggregation seen in the same model configured to run in idealized radiative-convective equilibriu...

  6. Columbia River System Operation Review final environmental impact statement. Summary

    International Nuclear Information System (INIS)

    1995-11-01

    The Columbia River System Operation Review (SOR) is being conducted jointly by the US Army Corps of Engineers, the Bureau of Reclamation, and the Bonneville Power Administration. This summary of the SOR story begins where the Draft EIS summary left off. It is divided into seven parts, each of which reports some aspect of the study's outcome: Part 1 is a history. The SOR was not a simple study on any level, and to understand the EIS alternatives, some background is necessary. Part 2 reports the major findings of the technical analysis of alternative system operating strategies, and presents the agencies' Preferred Alternative. Part 3 explains actions the agencies may take with respect to the Columbia River Regional Forum, the Pacific Northwest Coordination Agreement, and the Canadian Entitlement Allocation Agreements. Part 4 presents the Purpose and Need, elements at the core of any Federal EIS. It includes a map showing the Columbia River Basin and information on the affected Federal projects. Part 5 describes the substantial public participation and outreach that occurred during the SOR, and Part 6 summarizes efforts to incorporate the Tribal perspective into the study. Part 7 describes other activities that will be taking place in the next few years, which are related to and build upon the SOR

  7. Faulted systems recovery experience. Final report, May 1992

    International Nuclear Information System (INIS)

    1992-05-01

    This report addresses the recovery (i.e., return to service from a faulted, or otherwise unavailable, condition) of important nuclear power plant front-line and support systems and equipment. It contains information based on operating experience relative to the times to recover from a variety of plant events. It also indicates the nature of the operator actions involved. This information is intended to provide useful insights to utilities who are undertaking Individual Plant Examinations (IPEs) per Generic Letter 88-20 of the Nuclear Regulatory Commission. The report provides a database of recovery experience primarily derived from Licensee Event Reports (LERs). The database contains recovery duration information for 205 demand events and 98 nondemand events. In particular, it contains recovery durations for 42 pump related and 143 valve related events that are representative of demand conditions. Experience shows that, overall, about one-half of all pumps and valves are recovered in 30 minutes or less. Specific recovery experience is dependent on the equipment type, the plant system involved, and the failure mode encountered. (author)

  8. Community Earth System Model (CESM) Tutorial 2016 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lamarque, Jean-Francois [Univ. Corporation for Atmospheric Research (UCAR) and National Center for Atmospheric Research (NCAR) and Climate and Global Dynamics Laboratory (CGD), Boulder, CO (United States)

    2017-05-09

    For the 2016 tutorial, NCAR/CGD requested a total budget of $70,000 split equally between DOE and NSF. The funds were used to support student participation (travel, lodging, per diem, etc.). Lectures and practical session support was primarily provided by local participants at no additional cost (see list below). The seventh annual Community Earth System Model (CESM) tutorial (2016) for students and early career scientists was held 8 – 12 August 2016. As has been the case over the last few years, this event was extremely successful and there was greater demand than could be met. There was continued interest in support of the NSF’s EaSM Infrastructure awards, to train these awardees in the application of the CESM. Based on suggestions from previous tutorial participants, the 2016 tutorial experience again provided direct connection to Yellowstone for each individual participant (rather than pairs), and used the NCAR Mesa Library. The 2016 tutorial included lectures on simulating the climate system and practical sessions on running CESM, modifying components, and analyzing data. These were targeted to the graduate student level. In addition, specific talks (“Application” talks) were introduced this year to provide participants with some in-depth knowledge of some specific aspects of CESM.

  9. User effects on the transient system code calculations. Final report

    International Nuclear Information System (INIS)

    Aksan, S.N.; D'Auria, F.

    1995-01-01

    Large thermal-hydraulic system codes are widely used to perform safety and licensing analyses of nuclear power plants to optimize operational procedures and the plant design itself. Evaluation of the capabilities of these codes are accomplished by comparing the code predictions with the measured experimental data obtained from various types of separate effects and integral test facilities. In recent years, some attempts have been made to establish methodologies to evaluate the accuracy and the uncertainty of the code predictions and consequently judgement on the acceptability of the codes. In none of the methodologies has the influence of the code user on the calculated results been directly addressed. In this paper, the results of the investigations on the user effects for the thermal-hydraulic transient system codes is presented and discussed on the basis of some case studies. The general findings of the investigations show that in addition to user effects, there are other reasons that affect the results of the calculations and which are hidden under user effects. Both the hidden factors and the direct user effects are discussed in detail and general recommendations and conclusions are presented to control and limit them

  10. Integrated System Health Management (ISHM) Technology Demonstration Project Final Report

    Science.gov (United States)

    Mackey, Ryan; Iverson, David; Pisanich, Greg; Toberman, Mike; Hicks, Ken

    2006-01-01

    Integrated System Health Management (ISHM) is an essential capability that will be required to enable upcoming explorations mission systems such as the Crew Exploration Vehicle (CEV) and Crew Launch Vehicle (CLV), as well as NASA aeronautics missions. However, the lack of flight experience and available test platforms have held back the infusion by NASA Ames Research Center (ARC) and the Jet Propulsion Laboratory (JPL) of ISHM technologies into future space and aeronautical missions. To address this problem, a pioneer project was conceived to use a high-performance aircraft as a low-cost proxy to develop, mature, and verify the effectiveness of candidate ISHM technologies. Given the similarities between spacecraft and aircraft, an F/A-18 currently stationed at Dryden Flight Research Center (DFRC) was chosen as a suitable host platform for the test bed. This report describes how the test bed was conceived, how the technologies were integrated on to the aircraft, and how these technologies were matured during the project. It also describes the lessons learned during the project and a forward path for continued work.

  11. Canister Cleaning System Final Design Report - Project A.2.A

    International Nuclear Information System (INIS)

    FARWICK, C.C.

    2000-01-01

    Approximately 2,300 metric tons Spent Nuclear Fuel (SNF) are currently stored within two water filled pools, the 105 K East (KE) fuel storage basin and the 105 K West (KW) fuel storage basin, at the U.S. Department of Energy, Richland Operations Office (RL). The SNF Project is responsible for operation of the K Basins and for the materials within them. A subproject to the SNF Project is the Debris Removal Subproject, which is responsible for removal of empty canisters and lids from the basins. The Canister Cleaning System (CCS) is part of the Debris Removal Project. The CCS will be installed in the KW Basin and operated during the fuel removal activity. The KW Basin has approximately 3600 canisters that require removal from the basin. The CCS is being designed to ''clean'' empty fuel canisters and lids and package them for disposal to the Environmental Restoration Disposal Facility complex. The system will interface with the KW Basin and be located in the Dummy Elevator Pit

  12. Community-Level Impacts Projection System (CLIPS). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Monts, J.K.; Bareiss, E.R.

    1979-02-01

    The Community-Level Impacts Projection System includes a set of techniques for providing detailed advance information required for rational planning. The computerized system generates reports which enable the user: to describe the energy development activity in terms of its employment demands and spatial location; to estimate how many in-migrating workers will be required; to estimate the demographic characteristics of the in-migrating workers (e.g., how many elementary school children they will bring); to estimate how many additional secondary employment opportunities (e.g., employment in eating and drinking establishments and grocery stores) will be generated; to estimate what the local area's population levels in various age groups would be both with the project and without it; to estimate community population levels for both the impact case and the baseline case; and to estimate the approximate resource requirements and costs for providing additional municipal facilities and services (e.g., water treatment and distribution, wastewater treatment and collection, gas and electric distribution, police and fire protection, etc.)

  13. Equilibrium system analysis in a tokamak ignition experiment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Carrera, R.; Weldon, W.F.; Woodson, H.H.

    1989-10-01

    The objective of the IGNITEX Project is to produce and control ignited plasmas for scientific study in the simplest and least expensive way possible. The original concept was proposed by both physics and engineering researchers along the following line of thought. Question: Is there any theoretically simple, compact and reliable way of achieving fusion ignition according to the results of the fusion research program for the last decades? Answer: Yes. An experiment to be carried out in an ohmically heated compact tokamak device with 20 T field on plasma axis. Question: Is there any practical way to carry out that experiment at low cost in the near term? Answer: Yes. Using a single-turn coil magnet system with homopolar power supplies.

  14. Systems study 'Alternative Entsorgung'. Final report. Technical annex 16

    International Nuclear Information System (INIS)

    1984-04-01

    The system is subdivided into three complexes: conventional fission product bookkeeping with quantity checks on incoming and outgoing material at a few key measuring points as well as inventory on the occasion of the annual closedown for operational reasons; determination of inventory and balancing with the plant in operation via the measuring data of in-process instrumentation of vessels and apparatures in fule reprocessing or tracing of fission products in mixed oxide manufacture by charges down to the production of fuel elements, respectively; control checks at crucial monitoring points by measures of spatial limitation (containment) and observation (surveillance) to be determined by means of analyses of relevant diversion pathways carried out systematically. (orig./HP) [de

  15. Traffic congestion forecasting model for the INFORM System. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Azarm, A.; Mughabghab, S.; Stock, D.

    1995-05-01

    This report describes a computerized traffic forecasting model, developed by Brookhaven National Laboratory (BNL) for a portion of the Long Island INFORM Traffic Corridor. The model has gone through a testing phase, and currently is able to make accurate traffic predictions up to one hour forward in time. The model will eventually take on-line traffic data from the INFORM system roadway sensors and make projections as to future traffic patterns, thus allowing operators at the New York State Department of Transportation (D.O.T.) INFORM Traffic Management Center to more optimally manage traffic. It can also form the basis of a travel information system. The BNL computer model developed for this project is called ATOP for Advanced Traffic Occupancy Prediction. The various modules of the ATOP computer code are currently written in Fortran and run on PC computers (pentium machine) faster than real time for the section of the INFORM corridor under study. The following summarizes the various routines currently contained in the ATOP code: Statistical forecasting of traffic flow and occupancy using historical data for similar days and time (long term knowledge), and the recent information from the past hour (short term knowledge). Estimation of the empirical relationships between traffic flow and occupancy using long and short term information. Mechanistic interpolation using macroscopic traffic models and based on the traffic flow and occupancy forecasted (item-1), and the empirical relationships (item-2) for the specific highway configuration at the time of simulation (construction, lane closure, etc.). Statistical routine for detection and classification of anomalies and their impact on the highway capacity which are fed back to previous items.

  16. Selected data for hydrothermal-convection systems in the United States with estimated temperatures greater than or equal to 90/sup 0/C: back-up data for US Geological Survey Circular 790

    Energy Technology Data Exchange (ETDEWEB)

    Mariner, R.H.; Brook, C.A.; Swanson, J.R.; Mabey, D.R.

    1978-12-01

    A compilation of data used in determining the accessible resource base for identified hydrothermal convection systems greater than or equal to 90/sup 0/C in the United States are presented. Geographic, geologic, chemical, isotopic, volumetric, and bibliographic data and calculated thermal energy contents are listed for all vapor-dominated and hot-water systems with estimated reservoir temperatures greater than or equal to 90/sup 0/C and reservoir depths less than 3 km known to the authors in mid 1978. Data presented here is stored in the US Geological Survey's geothermal computer file GEOTHERM. Data for individual hydrothermal convection systems in each state are arranged geographically from north to south and west to east without regard to the type or temperature of the system. Locations of the systems and corresponding reference numbers are shown on map 1 accompanying US Geological Survey Circular 790.

  17. Natural convection in superposed fluid-porous layers

    CERN Document Server

    Bagchi, Aniruddha

    2013-01-01

    Natural Convection in Composite Fluid-Porous Domains provides a timely overview of the current state of understanding on the phenomenon of convection in composite fluid-porous layers. Natural convection in horizontal fluid-porous layers has received renewed attention because of engineering problems such as post-accident cooling of nuclear reactors, contaminant transport in groundwater, and convection in fibrous insulation systems. Because applications of the problem span many scientific domains, the book serves as a valuable resource for a wide audience.

  18. CDM Convective Forecast Planning guidance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The CDM Convective Forecast Planning (CCFP) guidance product provides a foreast of en-route aviation convective hazards. The forecasts are updated every 2 hours and...

  19. Columbia River system operation review. Final environmental impact statement

    International Nuclear Information System (INIS)

    1995-11-01

    This study attempts to identify and analyze the impacts of the System Operating Strategy (SOS) alternatives on cultural resources. The impacts include effects on Native American traditional cultural values, properties and practices. They also include effects on archeological or historic properties meeting the criteria of the National Register of Historic Places. In addition to responding to the requirements of the National Environmental Policy Act (NEPA), this analysis addresses the requirements of the National Historic Preservation Act (NHPA), the Archeological Resources Protection Act (ARPA), the Native American Graves Protection and Repatriation Act (NAGPRA), the Native American Religious Freedom Act (NARFA), and other relevant legislation. To meet their legally mandated cultural resources requirements, the SOR agencies will develop agreements and Implementation Plans with the appropriate State Historic Preservation Officers (SHPOs), Tribes, and the Advisory Council on Historic Preservation (ACHP) detailing the measures necessary to best manage the resource. The planning and implementation activities will be staged over a number of years in consultation with affected Tribes

  20. Cooperative field test program for wind systems. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bollmeier, W.S. II; Dodge, D.M.

    1992-03-01

    The objectives of the Federal Wind Energy Program, managed by the US Department of Energy (DOE), are (1) to assist industry and utilities in achieving a multi-regional US market penetration of wind systems, and (2) to establish the United States as the world leader in the development of advanced wind turbine technology. In 1984, the program conducted a series of planning workshops with representatives from the wind energy industry to obtain input on the Five-Year Research Plan then being prepared by DOE. One specific suggestion that came out of these meetings was that the federal program should conduct cooperative research tests with industry to enhance the technology transfer process. It was also felt that the active involvement of industry in DOE-funded research would improve the state of the art of wind turbine technology. DOE established the Cooperative Field Test Program (CFTP) in response to that suggestion. This program was one of the first in DOE to feature joint industry-government research test teams working toward common objectives.

  1. Columbia River system operation review. Final environmental impact statement

    International Nuclear Information System (INIS)

    1995-11-01

    Since the 1930's, the Columbia River has been harnessed for the benefit of the Northwest and the nation. Federal agencies have built 30 major dams on the river and its tributaries. Dozens of non-Federal projects have been developed as well. The dams provide flood control, irrigation, navigation, hydro-electric power generation, recreation, fish and wildlife, and streamflows for wildlife, anadromous fish, resident fish, and water quality. This is Appendix F of the Environmental Impact Statement for the Columbia River System, focusing on irrigation issues and concerns arrising from the Irrigation and Mitigation of impacts (M ampersand I) working Group of the SOR process. Major subheadings include the following: Scope and process of irrigation/M ampersand I studies; Irrigation/M ampersand I in the Columbia Basin Today including overview, irrigated acreage and water rights, Irrigation and M ampersand I issues basin-wide and at specific locations; and the analysis of impacts and alternative for the Environmental Impact Statement

  2. Rooftop PV system. Final technical progress report, Phase II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    Under this four-year PV:BONUS Program, ECD and United Solar are developing and demonstrating two new lightweight flexible building integrated Photovoltaic (BIPV) modules specifically designed as exact replacements for conventional asphalt shingles and standing seam metal roofing. These modules can be economically and aesthetically integrated into new residential and commercial buildings, and address the even larger roofing replacement market. The modules are designed to be installed by roofing contractors without special training which minimizes the installation and balance of system costs. The modules will be fabricated from high-efficiency, multiple-junction a-Si alloy solar cells developed by ECD and United Solar. Under the Phase I Program, which ended in March 1994, we developed two different concept designs for rooftop PV modules: (1) the United Solar overlapping (asphalt shingle replacement) shingle-type modules and (2) the ECD metal roof-type modules. We also developed a plan for fabricating, testing and demonstrating these modules. Candidate demonstration sites for our rooftop PV modules were identified and preliminary engineering designs for these demonstrations were developed; a marketing study plan was also developed. The major objectives of the Phase II Program, which started in June 1994 was (1) to develop, test, and qualify these new rooftop modules; (2) to develop mechanical and electrical engineering specifications for the demonstration projects; and (3) to develop a marketing/commercialization plan.

  3. Primary Issues of Mixed Convection Heat Transfer Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Myeong-Seon; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-10-15

    The computer code analyzing the system operating and transient behavior must distinguish flow conditions involved with convective heat transfer flow regimes. And the proper correlations must be supplied to those flow regimes. However the existing safety analysis codes are focused on the Light Water Reactor and they are skeptical to be applied to the GCRs (Gas Cooled Reactors). One of the technical issues raise by the development of the VHTR is the mixed convection, which occur when the driving forces of both forced and natural convection are of comparable magnitudes. It can be encountered as in channel of the stacked with fuel elements and a decay heat removal system and in VHTR. The mixed convection is not intermediate phenomena with natural convection and forced convection but independent complicated phenomena. Therefore, many researchers have been studied and some primary issues were propounded for phenomena mixed convection. This paper is to discuss some problems identified through reviewing the papers for mixed convection phenomena. And primary issues of mixed convection heat transfer were proposed respect to thermal hydraulic problems for VHTR. The VHTR thermal hydraulic study requires an indepth study of the mixed convection phenomena. In this study we reviewed the classical flow regime map of Metais and Eckert and derived further issues to be considered. The following issues were raised: (1) Buoyancy aided an opposed flows were not differentiated and plotted in a map. (2) Experimental results for UWT and UHF condition were also plotted in the same map without differentiation. (3) The buoyancy coefficient was not generalized for correlating with buoyancy coefficient. (4) The phenomenon analysis for laminarization and returbulization as buoyancy effects in turbulent mixed convection was not established. (5) The defining to transition in mixed convection regime was difficult.

  4. Convective Cold Pool Structure and Boundary Layer Recovery in DYNAMO

    Science.gov (United States)

    Savarin, A.; Chen, S. S.; Kerns, B. W.; Lee, C.; Jorgensen, D. P.

    2012-12-01

    One of the key factors controlling convective cloud systems in the Madden-Julian Oscillation (MJO) over the tropical Indian Ocean is the property of the atmospheric boundary layer. Convective downdrafts and precipitation from the cloud systems produce cold pools in the boundary layer, which can inhibit subsequent development of convection. The recovery time is the time it takes for the boundary layer to return to pre convective conditions. It may affect the variability of the convection on various time scales during the initiation of MJO. This study examines the convective cold pool structure and boundary layer recovery using the NOAA WP-3D aircraft observations, include the flight-level, Doppler radar, and GPS dropsonde data, collected during the Dynamics of MJO (DYNAMO) field campaign from November-December 2011. The depth and strength of convective cold pools are defined by the negative buoyancy, which can be computed from the dropsonde data. Convective downdraft can be affected by environmental water vapor due to entrainment. Mid-level dry air observed during the convectively suppressed phase of MJO seems to enhance convective downdraft, making the cold pools stronger and deeper. Recovery of the cold pools in the boundary layer is determined by the strength and depth of the cold pools and also the air-sea heat and moisture fluxes. Given that the water vapor and surface winds are distinct for the convectively active and suppressed phases of MJO over the Indian Ocean, the aircraft data are stratified by the two different large-scale regimes of MJO. Preliminary results show that the strength and depth of the cold pools are inversely correlated with the surrounding mid-level moisture. During the convectively suppressed phase, the recovery time is ~5-20 hours in relative weak wind condition with small air-sea fluxes. The recovery time is generally less than 6 hours during the active phase of MJO with moist mid-levels and stronger surface wind and air-sea fluxes.

  5. National Geoscience Data Repository System: Phase 2 final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The American Geological Institute (AGI) has completed Phase 2 of a project to establish a National Geoscience Data Repository System (NGDRS). The project`s primary objectives are to preserve geoscience data in jeopardy of being destroyed and to make that data available to those who have a need to use it in future investigations. These data are available for donation to the public as a result of the downsizing that has occurred in the major petroleum and mining companies in the US for the past decade. In recent years, these companies have consolidated domestic operations, sold many of their domestic properties and relinquished many of their leases. The scientific data associated with those properties are no longer considered to be useful assets and are consequently in danger of being lost forever. The national repository project will make many of these data available to the geoscience community for the first time. Phase 2 encompasses the establishment of standards for indexing and cataloging of geoscience data and determination of the costs of transferring data from the private sector to public-sector data repositories. Pilot projects evaluated the feasibility of the project for transfer of different data types and creation of a Web-based metadata supercatalog and browser. Also as part of the project, a national directory of geoscience data repositories was compiled to assess what data are currently available in existing facilities. The next step, Phase 3, will focus on the initiation of transfer of geoscience data from the private sector to the public domain and development of the web-based Geotrek metadata supercatalog.

  6. Radiation-induced effects in organic systems. Final report

    International Nuclear Information System (INIS)

    Johnsen, R.H.

    1982-01-01

    This project, which is of twenty-seven years duration, has been devoted to furthering our basic understanding of the processes involved in the absorption and distribution of high-energy radiation in organic molecules. The early phases of the work were concerned with the gross chemical effects of radiation and included studies in a number of important classes of organic compounds including alcohols, aliphatic acids, aliphatic hydrocarbons, and aromatic hydrocarbons. Basic information was acquired through these studies that has led to a better understanding of the effects of high-energy radiation on condensed media. During this period the so-called protective effect of low concentrations of aromatic hydrocarbons was also studied. A contribution of lasting significance at this time was the development of a technique for the post-radiolysis analysis of trapped free radicals by photochemical means. A comprehensive series of papers on the reactions of thermal hydrogen atoms with frozen organic substrates represented the beginning of a new phase in the approach to the problems of radiation chemistry in this laboratory. Since that time the general philosophy guided the research has been to single out events or processes suspected of contributing to the gross-radiation effect and study them in isolation. Thus from 1970 on efforts were devoted to charge-exchange processes, ionization efficiencies (w-values), radical decay process in solids and ion-dissociation reactions. The first by means of a modified time-of-flight mass spectrometer, the second utilizing an ionization chamber constructed in the FSU shops, the third using electron spin resonance detection, and the last involving the use of a dual mass spectrometer, solid target system invented in our laboratory. The most productive of these efforts has been the radical decay work

  7. Convective overshooting in stars

    NARCIS (Netherlands)

    Andrássy, R.

    2015-01-01

    Numerous observations provide evidence that the standard picture, in which convective mixing is limited to the unstable layers of a star, is incomplete. The mixing layers in real stars are significantly more extended than what the standard models predict. Some of the observations require changing

  8. Blade System Design Study. Part II, final project report (GEC).

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, Dayton A. (DNV Global Energy Concepts Inc., Seattle, WA)

    2009-05-01

    As part of the U.S. Department of Energy's Low Wind Speed Turbine program, Global Energy Concepts LLC (GEC)1 has studied alternative composite materials for wind turbine blades in the multi-megawatt size range. This work in one of the Blade System Design Studies (BSDS) funded through Sandia National Laboratories. The BSDS program was conducted in two phases. In the Part I BSDS, GEC assessed candidate innovations in composite materials, manufacturing processes, and structural configurations. GEC also made recommendations for testing composite coupons, details, assemblies, and blade substructures to be carried out in the Part II study (BSDS-II). The BSDS-II contract period began in May 2003, and testing was initiated in June 2004. The current report summarizes the results from the BSDS-II test program. Composite materials evaluated include carbon fiber in both pre-impregnated and vacuum-assisted resin transfer molding (VARTM) forms. Initial thin-coupon static testing included a wide range of parameters, including variation in manufacturer, fiber tow size, fabric architecture, and resin type. A smaller set of these materials and process types was also evaluated in thin-coupon fatigue testing, and in ply-drop and ply-transition panels. The majority of materials used epoxy resin, with vinyl ester (VE) resin also used for selected cases. Late in the project, testing of unidirectional fiberglass was added to provide an updated baseline against which to evaluate the carbon material performance. Numerous unidirectional carbon fabrics were considered for evaluation with VARTM infusion. All but one fabric style considered suffered either from poor infusibility or waviness of fibers combined with poor compaction. The exception was a triaxial carbon-fiberglass fabric produced by SAERTEX. This fabric became the primary choice for infused articles throughout the test program. The generally positive results obtained in this program for the SAERTEX material have led to its

  9. System composition and operation of exposure dose registration and control system (Final report)

    International Nuclear Information System (INIS)

    1978-01-01

    Since November, 1976, the committee concerning the investigation of exposure dose registration and control system for employees in nuclear industries has discussed on the exposure dose registration and control system, issued the interim report (outline) in April, 1977, and continued to investigate the details organizing the working group. Here, the final report is presented. It describes first on the definition of the terms used and the basic concept of the exposure dose registration and control system, in which the name of that organization is decided as ''Central Registration Office for Radiation Works'', Radiation Influence Association, the foundational juridical person. Next, the works to be performed in the Center and nuclear energy enterprises are explained. The items concerning the business management at the time of practical execution are the major part of the report, and are over 22 items. These include the registration business, the official reporting business, inquiry and answer business about career, change and revision, and computer processing system. As the temporary measures for transfer ring to the new system, 10 items are also provided. Supplementary explanation of 9 important items is given in the appendix. (Wakatsuki, Y.)

  10. Simulation of decay heat removal by natural convection in a pool type fast reactor model-ramona-with coupled 1D/2D thermal hydraulic code system

    Energy Technology Data Exchange (ETDEWEB)

    Kasinathan, N.; Rajakumar, A.; Vaidyanathan, G.; Chetal, S.C. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    1995-09-01

    Post shutdown decay heat removal is an important safety requirement in any nuclear system. In order to improve the reliability of this function, Liquid metal (sodium) cooled fast breeder reactors (LMFBR) are equipped with redundant hot pool dipped immersion coolers connected to natural draught air cooled heat exchangers through intermediate sodium circuits. During decay heat removal, flow through the core, immersion cooler primary side and in the intermediate sodium circuits are also through natural convection. In order to establish the viability and validate computer codes used in making predictions, a 1:20 scale experimental model called RAMONA with water as coolant has been built and experimental simulation of decay heat removal situation has been performed at KfK Karlsruhe. Results of two such experiments have been compiled and published as benchmarks. This paper brings out the results of the numerical simulation of one of the benchmark case through a 1D/2D coupled code system, DHDYN-1D/THYC-2D and the salient features of the comparisons. Brief description of the formulations of the codes are also included.

  11. 75 FR 11002 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Final Rule

    Science.gov (United States)

    2010-03-10

    ... Waste Management System; Identification and Listing of Hazardous Waste; Final Rule AGENCY: Environmental... and specific types of management of the petitioned waste, the quantities of waste generated, and waste... wastes. This final rule responds to a petition submitted by Valero to delist F037 waste. The F037 waste...

  12. Analysis of a Small Vigorous Mesoscale Convective System in a Low-Shear Environment. Pt. 1; Formation, Echo Structure and Lightning Behavior

    Science.gov (United States)

    Knupp, Kevin; Geerts, Bart; Goodman, Steven J.

    1997-01-01

    The precipitation output was highly variable due to the transient nature of the intense convective elements. This result is attributed to the high Richardson number (175) of the environment, which is much higher than that of the typical MCS environment. The development of the stratiform precipitation was accomplished locally (in situ), and not be advection of from the convective region. In situ charging of the stratiform region is also supported by the observations.

  13. Convective Propagation Characteristics Using a Simple Representation of Convective Organization

    Science.gov (United States)

    Neale, R. B.; Mapes, B. E.

    2016-12-01

    Observed equatorial wave propagation is intimately linked to convective organization and it's coupling to features of the larger-scale flow. In this talk we a use simple 4 level model to accommodate vertical modes of a mass flux convection scheme (shallow, mid-level and deep). Two paradigms of convection are used to represent convective processes. One that has only both random (unorganized) diagnosed fluctuations of convective properties and one with organized fluctuations of convective properties that are amplified by previously existing convection and has an explicit moistening impact on the local convecting environment We show a series of model simulations in single-column, 2D and 3D configurations, where the role of convective organization in wave propagation is shown to be fundamental. For the optimal choice of parameters linking organization to local atmospheric state, a broad array of convective wave propagation emerges. Interestingly the key characteristics of propagating modes are the low-level moistening followed by deep convection followed by mature 'large-scale' heating. This organization structure appears to hold firm across timescales from 5-day wave disturbances to MJO-like wave propagation.

  14. The impact of reflectivity correction and conversion methods to improve precipitation estimation by weather radar for an extreme low-land Mesoscale Convective System

    Science.gov (United States)

    Hazenberg, Pieter; Leijnse, Hidde; Uijlenhoet, Remko

    2014-05-01

    Between 25 and 27 August 2010 a long-duration mesoscale convective system was observed above the Netherlands. For most of the country this led to over 15 hours of near-continuous precipitation, which resulted in total event accumulations exceeding 150 mm in the eastern part of the Netherlands. Such accumulations belong to the largest sums ever recorded in this country and gave rise to local flooding. Measuring precipitation by weather radar within such mesoscale convective systems is known to be a challenge, since measurements are affected by multiple sources of error. For the current event the operational weather radar rainfall product only estimated about 30% of the actual amount of precipitation as measured by rain gauges. In the current presentation we will try to identify what gave rise to such large underestimations. In general weather radar measurement errors can be subdivided into two different groups: 1) errors affecting the volumetric reflectivity measurements taken, and 2) errors related to the conversion of reflectivity values in rainfall intensity and attenuation estimates. To correct for the first group of errors, the quality of the weather radar reflectivity data was improved by successively correcting for 1) clutter and anomalous propagation, 2) radar calibration, 3) wet radome attenuation, 4) signal attenuation and 5) the vertical profile of reflectivity. Such consistent corrections are generally not performed by operational meteorological services. Results show a large improvement in the quality of the precipitation data, however still only ~65% of the actual observed accumulations was estimated. To further improve the quality of the precipitation estimates, the second group of errors are corrected for by making use of disdrometer measurements taken in close vicinity of the radar. Based on these data the parameters of a normalized drop size distribution are estimated for the total event as well as for each precipitation type separately (convective

  15. Mixed thermal convection: fundamental issues and analysis of the planar case

    Directory of Open Access Journals (Sweden)

    JACQUES PADET

    2015-09-01

    Full Text Available This paper aims to renew interest on mixed thermal convection research and to emphasize three issues that arise from the present analysis: (i a clear definition of the reference temperature in the Boussinesq approximation; (ii a practical delimitation of the three convective modes, which are the forced convection (FC, mixed convection (MC and natural (or free convection (NC; (iii and, finally, a uniform description of the set FC/MC/NC in the similarity framework. The planar case, for which analytical solutions are available, allows a detailed illustration of the answers here advanced to the above issues.

  16. Convective losses through an air-filled gap

    Energy Technology Data Exchange (ETDEWEB)

    Baum, V A; Ovezsakhatov, N

    1976-01-01

    Simplified formulas for the heat fluxes with given parameters of the air are used to calculate the specific heat losses by convection in a number of solar-energy systems (water heater, thermal generator, double-glazed window, and still). Heat losses by convection and radiation are compared.

  17. Interaction of externally-driven acoustic waves with compressible convection

    International Nuclear Information System (INIS)

    Jones, P.; Merryfield, W.

    1992-01-01

    Two-dimensional numerical simulations are used to examine the interaction of acoustic waves with a compressible convecting fluid. Acoustic waves are forced at the lower boundary of the computational domain and propagate through a three-layer system undergoing vigorous penetrative convection. Energy exchange between the wave and the fluid is analyzed using a work integral formulation

  18. What Determines Upscale Growth of Oceanic Convection into MCSs?

    Science.gov (United States)

    Zipser, E. J.

    2017-12-01

    Over tropical oceans, widely scattered convection of various depths may or may not grow upscale into mesoscale convective systems (MCSs). But what distinguishes the large-scale environment that favors such upscale growth from that favoring "unorganized", scattered convection? Is it some combination of large-scale low-level convergence and ascending motion, combined with sufficient instability? We recently put this to a test with ERA-I reanalysis data, with disappointing results. The "usual suspects" of total column water vapor, large-scale ascent, and CAPE may all be required to some extent, but their differences between large MCSs and scattered convection are small. The main positive results from this work (already published) demonstrate that the strength of convection is well correlated with the size and perhaps "organization" of convective features over tropical oceans, in contrast to tropical land, where strong convection is common for large or small convective features. So, important questions remain: Over tropical oceans, how should we define "organized" convection? By size of the precipitation area? And what environmental conditions lead to larger and better organized MCSs? Some recent attempts to answer these questions will be described, but good answers may require more data, and more insights.

  19. 76 FR 16534 - Hazardous Waste Management System Identification and Listing of Hazardous Waste; Final Exclusion

    Science.gov (United States)

    2011-03-24

    ... Waste Management System Identification and Listing of Hazardous Waste; Final Exclusion AGENCY...) on a one-time basis from the lists of hazardous waste, a certain solid waste generated at its Mt... waste is [[Page 16535

  20. Freight Advanced Traveler Information System (FRATIS) - Dallas-Fort Worth (DFW) prototype : final report.

    Science.gov (United States)

    This is the Final Report for the FRATIS Dallas-Fort Worth DFW prototype system. The FRATIS prototype in : DFW consisted of the following components: optimization algorithm, terminal wait time, route specific : navigation/traffic/weather, and advanced...

  1. Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational, and Systems Biology (Final Report)

    Science.gov (United States)

    EPA announced the release of the final report, Next Generation Risk Assessment: Incorporation of Recent Advances in Molecular, Computational, and Systems Biology. This report describes new approaches that are faster, less resource intensive, and more robust that can help ...

  2. Systems analysis for the development of small resource recovery systems: system performance data. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crnkovich, P G; Helmstetter, A J

    1980-10-01

    The technologies that should be developed to make small-scale solid waste processing facilities attractive and viable for small municipalities with solid waste between 50 and 250 tons per day are identified. The resource recovery systems investigated were divided into three categories: thermal processng, mechanical separation, and biological processing. Thermal processing systems investigated are: excess-air incineration; starved-air incineration/gasification; and pyrolysis (indirect heating). Mechanical processing systems investigated are: coarse refuse derived fuel; materials separation; dust refuse derived fuel; densified refuse derived fuel; and fine refuse derived fuel. Mechanical processing components investigated include: receiving module; primary size reduction module; combustible separation module; refuse derived fuel preparation module; fuel densification; fuel storage module; ferrous separation; and building and facilities. Pretreatment processes and principle methods of bioconversion of MSW dealing with biological processing are investigated. (MCW)

  3. Convective transport resistance in the vitreous humor

    Science.gov (United States)

    Penkova, Anita; Sadhal, Satwindar; Ratanakijsuntorn, Komsan; Moats, Rex; Tang, Yang; Hughes, Patrick; Robinson, Michael; Lee, Susan

    2012-11-01

    It has been established by MRI visualization experiments that the convection of nanoparticles and large molecules with high rate of water flow in the vitreous humor will experience resistance, depending on the respective permeabilities of the injected solute. A set of experiments conducted with Gd-DTPA (Magnevist, Bayer AG, Leverkusen, Germany) and 30 nm gadolinium-based particles (Gado CELLTrackTM, Biopal, Worcester, MA) as MRI contrast agents showed that the degree of convective transport in this Darcy-type porous medium varies between the two solutes. These experiments consisted of injecting a mixture of the two (a 30 μl solution of 2% Magnevist and 1% nanoparticles) at the middle of the vitreous of an ex vivo whole bovine eye and subjecting the vitreous to water flow rate of 100 μl/min. The water (0.9% saline solution) was injected at the top of the eye, and was allowed to drain through small slits cut at the bottom of the eyeball. After 50 minutes of pumping, MRI images showed that the water flow carried the Gd-DTPA farther than the nanoparticles, even though the two solutes, being mixed, were subjected to the same convective flow conditions. We find that the convected solute lags the water flow, depending on the solute permeability. The usual convection term needs to be adjusted to allow for the filtration effect on the larger particles in the form (1- σ) u . ∇ c with important implications for the modeling of such systems.

  4. Two-dimensional turbulent convection

    Science.gov (United States)

    Mazzino, Andrea

    2017-11-01

    We present an overview of the most relevant, and sometimes contrasting, theoretical approaches to Rayleigh-Taylor and mean-gradient-forced Rayleigh-Bénard two-dimensional turbulence together with numerical and experimental evidences for their support. The main aim of this overview is to emphasize that, despite the different character of these two systems, especially in relation to their steadiness/unsteadiness, turbulent fluctuations are well described by the same scaling relationships originated from the Bolgiano balance. The latter states that inertial terms and buoyancy terms balance at small scales giving rise to an inverse kinetic energy cascade. The main difference with respect to the inverse energy cascade in hydrodynamic turbulence [R. H. Kraichnan, "Inertial ranges in two-dimensional turbulence," Phys. Fluids 10, 1417 (1967)] is that the rate of cascade of kinetic energy here is not constant along the inertial range of scales. Thanks to the absence of physical boundaries, the two systems here investigated turned out to be a natural physical realization of the Kraichnan scaling regime hitherto associated with the elusive "ultimate state of thermal convection" [R. H. Kraichnan, "Turbulent thermal convection at arbitrary Prandtl number," Phys. Fluids 5, 1374-1389 (1962)].

  5. 78 FR 32427 - Notice of Issuance of Final Determination Concerning Multifunctional Digital Imaging Systems

    Science.gov (United States)

    2013-05-30

    ... multifunctional digital imaging systems for purposes of U.S. Government procurement. DATES: The final... Determination Concerning Multifunctional Digital Imaging Systems AGENCY: U.S. Customs and Border Protection... country of origin of certain multifunctional digital imaging systems. Based upon the facts presented, CBP...

  6. Study of plasma convection and wall interactions in magnetic confinement systems. Progress report, October 1, 1982-November 30, 1984

    International Nuclear Information System (INIS)

    York, T.M.

    1984-06-01

    Studies of compact toroid formation and lifetime in high fill pressure discharges are reported. Extended lifetimes without rotation disruption and with low indicated resistivity have been identified experimentally. Numerical codes have modeled static and translating CT plasmas. Nd:Glass lasers for Thomson scattering diagnostics have been studied in detail. Comparison of system performance achieved with ruby, Nd:Glass and Nd:Glass/KDP sources is reported. Performances of a single pulse 80 J system and a 10 ms mode-locked system have been defined by basic experimental studies

  7. A novel double-convection chaotic attractor, its adaptive control and circuit simulation

    Science.gov (United States)

    Mamat, M.; Vaidyanathan, S.; Sambas, A.; Mujiarto; Sanjaya, W. S. M.; Subiyanto

    2018-03-01

    A 3-D novel double-convection chaotic system with three nonlinearities is proposed in this research work. The dynamical properties of the new chaotic system are described in terms of phase portraits, Lyapunov exponents, Kaplan-Yorke dimension, dissipativity, stability analysis of equilibria, etc. Adaptive control and synchronization of the new chaotic system with unknown parameters are achieved via nonlinear controllers and the results are established using Lyapunov stability theory. Furthermore, an electronic circuit realization of the new 3-D novel chaotic system is presented in detail. Finally, the circuit experimental results of the 3-D novel chaotic attractor show agreement with the numerical simulations.

  8. Terminal project heat convection in thin cylinders

    International Nuclear Information System (INIS)

    Morales Corona, J.

    1992-01-01

    Heat convection in thin cylinders and analysis about natural convection for straight vertical plates, and straight vertical cylinders submersed in a fluid are presented some works carry out by different authors in the field of heat transfer. In the part of conduction, deduction of the equation of heat conduction in cylindrical coordinates by means of energy balance in a control volume is presented. Enthalpy and internal energy are used for the outlining of the equation and finally the equation in its vectorial form is obtained. In the convection part development to calculate the Nusselt number for a straight vertical plate by a forces analysis, an energy balance and mass conservation over a control volume is outlined. Several empiric correlations to calculate the Nusselt number and its relations with other dimensionless numbers are presented. In the experimental part the way in which a prototype rode is assembled is presented measurements of temperatures attained in steady state and in free convection for working fluids as air and water are showed in tables. Also graphs of Nusselt numbers obtained in the experimental way through some empiric correlations are showed (Author)

  9. Lattice BGK simulation of natural convection

    International Nuclear Information System (INIS)

    Chen, Yu; Ohashi, Hirotada; Akiyama, Mamoru

    1995-01-01

    Recently a new thermal lattice Bhatnagar-Gross-Krook fluid model was suggested by the authors. In this study, this new model was applied into the numerical simulation of natural convection, namely the Rayleigh Benard flow. The critical number for the onset of convective phenomenon was numerically measured and compared with that of theoretical prediction. A gravity dependent deviation was found in the numerical simulation, which is explained as an unavoidable consequence of the incorporation of gravity force in the lattice BGK system. (author)

  10. Convection heat transfer

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    Written by an internationally recognized authority on heat transfer and thermodynamics, this second edition of Convection Heat Transfer contains new and updated problems and examples reflecting real-world research and applications, including heat exchanger design. Teaching not only structure but also technique, the book begins with the simplest problem solving method (scale analysis), and moves on to progressively more advanced and exact methods (integral method, self similarity, asymptotic behavior). A solutions manual is available for all problems and exercises.

  11. Heat transfer of laminar mixed convection of liquid

    CERN Document Server

    Shang, De-Yi

    2016-01-01

    This book presents a new algorithm to calculate fluid flow and heat transfer of laminar mixed convection. It provides step-by-step tutorial help to learn quickly how to set up the theoretical and numerical models of laminar mixed convection, to consider the variable physical properties of fluids, to obtain the system of numerical solutions, to create a series of formalization equations for the convection heat transfer by using a curve-fitting approach combined with theoretical analysis and derivation. It presents the governing ordinary differential equations of laminar mixed convection, equivalently transformed by an innovative similarity transformation with the description of the related transformation process. A system of numerical calculations of the governing ordinary differential equations is presented for the water laminar mixed convection. A polynomial model is induced for convenient and reliable treatment of variable physical properties of liquids. The developed formalization equations of mixed convec...

  12. Free convection film flows and heat transfer

    CERN Document Server

    Shang, Deyi

    2010-01-01

    Presents development of systematic studies for hydrodynamics and heat and mass transfer in laminar free convection, accelerating film boiling and condensation of Newtonian fluids, and accelerating film flow of non-Newtonian power-law fluids. This book provides a system of analysis models with a developed velocity component method.

  13. A 'backward' free-convective boundary layer

    NARCIS (Netherlands)

    Kuiken, H.K.

    1981-01-01

    In this paper the cooling of a low-heat-resistance sheet that moves downwards is considered. The free-convective velocities are assumed to be much larger than the velocity of the sheet. As a result the motion of the fluid is mainly towards the point where the sheet enters the system and a ‘backward’

  14. Los Angeles-Gateway Freight Advanced Traveler Information System : final system design and architecture for FRATIS prototype.

    Science.gov (United States)

    2013-05-01

    This Final Architecture and Design report has been prepared to describe the structure and design of all the system : components for the LA-Gateway FRATIS Demonstration Project. More specifically, this document provides: : Detailed descriptions of...

  15. Constraining storm-scale forecasts of deep convective initiation with surface weather observations

    Science.gov (United States)

    Madaus, Luke

    Successfully forecasting when and where individual convective storms will form remains an elusive goal for short-term numerical weather prediction. In this dissertation, the convective initiation (CI) challenge is considered as a problem of insufficiently resolved initial conditions and dense surface weather observations are explored as a possible solution. To better quantify convective-scale surface variability in numerical simulations of discrete convective initiation, idealized ensemble simulations of a variety of environments where CI occurs in response to boundary-layer processes are examined. Coherent features 1-2 hours prior to CI are found in all surface fields examined. While some features were broadly expected, such as positive temperature anomalies and convergent winds, negative temperature anomalies due to cloud shadowing are the largest surface anomaly seen prior to CI. Based on these simulations, several hypotheses about the required characteristics of a surface observing network to constrain CI forecasts are developed. Principally, these suggest that observation spacings of less than 4---5 km would be required, based on correlation length scales. Furthermore, it is anticipated that 2-m temperature and 10-m wind observations would likely be more relevant for effectively constraining variability than surface pressure or 2-m moisture observations based on the magnitudes of observed anomalies relative to observation error. These hypotheses are tested with a series of observing system simulation experiments (OSSEs) using a single CI-capable environment. The OSSE results largely confirm the hypotheses, and with 4-km and particularly 1-km surface observation spacing, skillful forecasts of CI are possible, but only within two hours of CI time. Several facets of convective-scale assimilation, including the need for properly-calibrated localization and problems from non-Gaussian ensemble estimates of the cloud field are discussed. Finally, the characteristics

  16. High-Resolution Modeling of the Predictability of Convective Systems, and Influences by Absorbing Aerosols Over Northern India and the Himalayas Foothills During Boreal Summer

    Science.gov (United States)

    Kim, Kyu-Myong; Lau, William K.-M.; Tao, Wei-Kuo; Shi, Jainn; Tan, Qian; Chin, Mian; Matsui, Toshihisa; Bian, Huisheng

    2011-01-01

    The Himalayas foothills region (HFR) is an important component of the South Asian monsoon. To the south, the HFR borders the fertile, populous, and heavily polluted Indo-Gangetic Plain (IGP). To the north, it rises to great height (approx. 4-5 km) to the Tibetan Plateau over a distance of less than 100 km. The HFR itself consists of complex mountainous terrain, with strong orographic forcing for precipitation. During the late spring and early summer, dust aerosol from the Thar and Middle East deserts , as well as moisture from the Arabian Sea were transported to the western part of the western part of the IGP and foothills spurs pre-monsoon severe thunderstorm over the region. During the monsoon season (mid June -August) convection from the Bay of Bengal, spread along the foothills northwestward to northern Pakistan. Recent climate model studies and preliminary observations have indicted not only the importance of dynamical forcing of precipitation in the HFR, but also possible strong impacts by the dense aerosols, from both local sources, and remote transport, that blanket the IGP from late spring up to the onset of the monsoon in June, and during monsoon breaks in July. In this work, we use the NASA Unified Weather Research and Forecasting (Nu-WRF) model to study the predictability ( 1-7 days) South Asian monsoon rainfall system. Results of 7 -day forecast experiments using an embedded domain of 27 km and 9 km resolution were conducted for the period June 11- July 15, 2008, with and without aerosol forcing are carried out to assess the intrinsic predictability of rainfall over the HFR, and possible impacts by aerosol direct effect, and possible connection of large-scale South Asian monsoon system.

  17. Thermal environment in simulated offices with convective and radiant cooling systems under cooling (summer) mode of operation

    DEFF Research Database (Denmark)

    Mustakallio, Panu; Bolashikov, Zhecho Dimitrov; Kostov, Kalin

    2016-01-01

    The thermal environment in a double office room and in a six-person meeting room obtained with chilled beam (CB), chilled beam with radiant panel (CBR), chilled ceiling with ceiling installed mixing ventilation (CCMV) and four desk partition-mounted local radiant cooling panels with mixing...... calculated. Manikin-based equivalent temperature (MBET) was determined by using two thermal manikins to identify the impact of the local thermal conditions generated by the studied systems on occupants' thermal perception. The results revealed that the differences in the thermal conditions achieved...

  18. Role of the magnetospheric convection and inertial forces informing the planetary structure of the ionosphere-protonosphere system

    International Nuclear Information System (INIS)

    Saenko, Yu.S.; Natsvalyan, N.S.; Tepenitsyna, N.Yu.; Shagimuratov, I.I.

    1991-01-01

    Mechanisms of forming the planetary distribution of concentrations and fluxes of basic O + and H + ions are investigated on the base of a three-dimensional nonstationary model of ionosphere-protonosphere system. The leading role of diffusion, drifts and inertia in the formation of such structural features as equatorial anomaly, mid-latitudinal gap, polar tail in F2-layer and plasmosphere, plasmosphere, plasma gap and polar wind in protonosphere, as well as regions with increased concentrations of heavy O + ions in the polar wind and plasmosphere, is demonstrated

  19. 78 FR 21389 - Notice of Issuance of Final Determination Concerning Certain Ultrasound Systems

    Science.gov (United States)

    2013-04-10

    ... following series of tests and system adjustments are performed: Electrical safety testing of the components... devices (printer etc.). An electrical safety test is then performed on the system's final configuration... boards assembled in Malaysia were important to the function of the oscilloscopes and the U.S. firmware...

  20. Benchmarking of thermalhydraulic loop models for lead-alloy-cooled advanced nuclear energy systems. Phase I: Isothermal forced convection case

    International Nuclear Information System (INIS)

    2012-06-01

    Under the auspices of the NEA Nuclear Science Committee (NSC), the Working Party on Scientific Issues of the Fuel Cycle (WPFC) has been established to co-ordinate scientific activities regarding various existing and advanced nuclear fuel cycles, including advanced reactor systems, associated chemistry and flowsheets, development and performance of fuel and materials and accelerators and spallation targets. The WPFC has different expert groups to cover a wide range of scientific issues in the field of nuclear fuel cycle. The Task Force on Lead-Alloy-Cooled Advanced Nuclear Energy Systems (LACANES) was created in 2006 to study thermal-hydraulic characteristics of heavy liquid metal coolant loop. The objectives of the task force are to (1) validate thermal-hydraulic loop models for application to LACANES design analysis in participating organisations, by benchmarking with a set of well-characterised lead-alloy coolant loop test data, (2) establish guidelines for quantifying thermal-hydraulic modelling parameters related to friction and heat transfer by lead-alloy coolant and (3) identify specific issues, either in modelling and/or in loop testing, which need to be addressed via possible future work. Nine participants from seven different institutes participated in the first phase of the benchmark. This report provides details of the benchmark specifications, method and code characteristics and results of the preliminary study: pressure loss coefficient and Phase-I. A comparison and analysis of the results will be performed together with Phase-II

  1. Power optimization in the STAR-LM modular natural convection reactor system. Topic 2.1 advanced reactor power plants

    International Nuclear Information System (INIS)

    Spencer, B.W.; Sienicki, J.J.; Farmer, M.T.

    2001-01-01

    The secure, transportable, autonomous reactor (STAR) project addresses the needs of developing countries and independent power producers for a small (300 MWt), multi-purpose energy system. The STAR-LM variant described here is a liquid metal cooled, fast spectrum reactor system. Previous development of a reference STAR-LM design resulted in a 300 MWt modular, pool- type reactor based on criteria for factory fabrication of modules, full transportability of modules (barge, rail, overland), fast construction and startup, and semi-autonomous operation. Earlier work on the reference 300 MWt concept focused first on addressing whether 100% natural circulation heat transport was achievable under the module size constraints for full transportability and under the coolant and cladding peak temperature limitations imposed by the existing Russian database for ferritic-martensitic core material with oxide-layer corrosion protection. Secondly, owing to uncertainties and limitations in the available Russian materials compatibility database, the objective of the reference design was to address how low the coolant and cladding peak temperatures could be commensurate with achieving 300 MWt power level with 100% natural circulation in a fully transportable module size. In the present work we have refocused the approach to attempt to maximize the power achievable in the reactor module based on preserving the criteria for full module transportability and remaining within the materials compatibility database limits. (author)

  2. Beam-based alignment and tuning procedures for e+e- collider final focus systems

    International Nuclear Information System (INIS)

    Bulos, F.; Burke, D.; Helm, R.; Irwin, J.; Odian, A.; Roy, G.; Ruth, R.; Yamamoto, N.

    1991-05-01

    For future linear colliders, with very small emittances and beam sizes and demanding tolerances on final focus system alignment and magnet errors, it becomes increasingly important to use the beam as a diagnostic tool. We report here procedures we have identified and will be implemented in the Final Focus Test Beam at SLAC incorporating (1) quadrupole strength changes, (2) central orbit modifications, (3) spot size measurements, and (4) beam stability monitoring. 3 refs., 4 figs., 3 tabs

  3. TRICARE revision to CHAMPUS DRG-based payment system, pricing of hospital claims. Final rule.

    Science.gov (United States)

    2014-05-21

    This Final rule changes TRICARE's current regulatory provision for inpatient hospital claims priced under the DRG-based payment system. Claims are currently priced by using the rates and weights that are in effect on a beneficiary's date of admission. This Final rule changes that provision to price such claims by using the rates and weights that are in effect on a beneficiary's date of discharge.

  4. Beam-based alignment and tuning procedures for e+e- collider final focus systems

    International Nuclear Information System (INIS)

    Bulos, F.; Burke, D.; Helm, R.; Irwin, J.; Odian, A.; Roy, G.; Ruth, R.; Yamamoto

    1991-01-01

    For future linear colliders, with very small emittances and beam sizes and demanding tolerances on final focus system alignment and magnet errors, it becomes increasingly important to use the beam as a diagnostic tool. The authors report here procedures they have identified and will be implemented in the Final Focus Test Beam at SLAC incorporating (1) quadrupole strength changes, (2) central orbit modifications, (3) spot size measurements, and (4) beam stability monitoring

  5. Boundary-modulated Thermal Convection Model in the Mantle

    Science.gov (United States)

    Kurita, K.; Kumagai, I.

    2008-12-01

    Analog experiments have played an important role in the constructing ideas of mantle dynamics. The series of experiments by H. Ramberg is one of the successful examples. Recently, however the realm of the analog experiments seems to be overwhelmed by steady progress of computer simulations. Is there still room for the analog experiments? This might be a main and hidden subject of this session. Here we propose a working hypothesis how the convecting mantle behaves based on the analog experiments in the system of viscous fluid and particles. The essential part is the interaction of convecting flow with heterogeneities existing in the boundaries. It is proposed the preexisting topographical heterogeneity in the boundary could control the flow pattern of convecting fluid. If this kind of heterogeneity can be formed as a consequence of convective motion and mobilized by the flow, the convection also can control the heterogeneity. We can expect interactions in two ways, by which the system behaves in a self-organize fashion. To explore the mutual interactions between convection flow and heterogeneity the system of viscous fluid and particles with slightly higher density is selected as 2D Rayleigh-Benard type convection. The basic structure consists of a basal particulate layer where permeable convection transports heat and an upper viscous fluid layer. By reducing the magnitude of the density difference the convective flow can mobilize the particles and can erode the basal layer. The condition of this erosion can be identified in the phase diagram of the particle Shields"f and the Rayleigh numbers. At Ra greater than 107 the convection style drastically changed before and after the erosion. Before the erosion where the flat interface of the boundary is maintained small scaled turbulent convection pattern is dominant. After the erosion where the interface becomes bumpy the large scale convective motion is observed. The structure is coherent to that of the boundary. This

  6. Effects of non-uniform temperature gradients on surface tension driven two component magneto convection in a porous- fluid system

    Science.gov (United States)

    Manjunatha, N.; Sumithra, R.

    2018-04-01

    The problem of surface tension driven two component magnetoconvection is investigated in a Porous-Fluid system, consisting of anincompressible two component electrically conducting fluid saturatedporous layer above which lies a layer of the same fluid in the presence of a uniform vertical magnetic field. The lower boundary of the porous layeris rigid and the upper boundary of the fluid layer is free with surfacetension effects depending on both temperature and concentration, boththese boundaries are insulating to heat and mass. At the interface thevelocity, shear and normal stress, heat and heat flux, mass and mass fluxare assumed to be continuous suitable for Darcy-Brinkman model. Theeigenvalue problem is solved in linear, parabolic and inverted parabolictemperature profiles and the corresponding Thermal Marangoni Numberis obtained for different important physical parameters.

  7. Testing particle filters on convective scale dynamics

    Science.gov (United States)

    Haslehner, Mylene; Craig, George. C.; Janjic, Tijana

    2014-05-01

    Particle filters have been developed in recent years to deal with highly nonlinear dynamics and non Gaussian error statistics that also characterize data assimilation on convective scales. In this work we explore the use of the efficient particle filter (P.v. Leeuwen, 2011) for convective scale data assimilation application. The method is tested in idealized setting, on two stochastic models. The models were designed to reproduce some of the properties of convection, for example the rapid development and decay of convective clouds. The first model is a simple one-dimensional, discrete state birth-death model of clouds (Craig and Würsch, 2012). For this model, the efficient particle filter that includes nudging the variables shows significant improvement compared to Ensemble Kalman Filter and Sequential Importance Resampling (SIR) particle filter. The success of the combination of nudging and resampling, measured as RMS error with respect to the 'true state', is proportional to the nudging intensity. Significantly, even a very weak nudging intensity brings notable improvement over SIR. The second model is a modified version of a stochastic shallow water model (Würsch and Craig 2013), which contains more realistic dynamical characteristics of convective scale phenomena. Using the efficient particle filter and different combination of observations of the three field variables (wind, water 'height' and rain) allows the particle filter to be evaluated in comparison to a regime where only nudging is used. Sensitivity to the properties of the model error covariance is also considered. Finally, criteria are identified under which the efficient particle filter outperforms nudging alone. References: Craig, G. C. and M. Würsch, 2012: The impact of localization and observation averaging for convective-scale data assimilation in a simple stochastic model. Q. J. R. Meteorol. Soc.,139, 515-523. Van Leeuwen, P. J., 2011: Efficient non-linear data assimilation in geophysical

  8. Natural Convection Analysis with Various Turbulent Models Using FLUENT

    International Nuclear Information System (INIS)

    Park, Yu Sun

    2007-01-01

    The buoyancy driven convective flow fields are steady circulatory flows which were made between surfaces maintained at two fixed temperatures. They are ubiquitous in nature and play an important role in many engineering applications. Especially, in last decades, natural convection in a close loop or cavity becomes the main issue in the molecular biology for the polymerase chain reaction (PCR). Application of a natural convection can reduce the costs and efforts remarkably. This paper focuses on the sensitivity study of turbulence analysis using CFD for a natural convection in a closed rectangular cavity. Using commercial CFD code, FLUENT, various turbulent models were applied to the turbulent flow. Results from each CFD model will be compared each other in the viewpoints of flow characteristics. This work will suggest the best turbulent model of CFD for analyzing turbulent flows of the natural convection in an enclosure system

  9. Strong convective storm nowcasting using a hybrid approach of convolutional neural network and hidden Markov model

    Science.gov (United States)

    Zhang, Wei; Jiang, Ling; Han, Lei

    2018-04-01

    Convective storm nowcasting refers to the prediction of the convective weather initiation, development, and decay in a very short term (typically 0 2 h) .Despite marked progress over the past years, severe convective storm nowcasting still remains a challenge. With the boom of machine learning, it has been well applied in various fields, especially convolutional neural network (CNN). In this paper, we build a servere convective weather nowcasting system based on CNN and hidden Markov model (HMM) using reanalysis meteorological data. The goal of convective storm nowcasting is to predict if there is a convective storm in 30min. In this paper, we compress the VDRAS reanalysis data to low-dimensional data by CNN as the observation vector of HMM, then obtain the development trend of strong convective weather in the form of time series. It shows that, our method can extract robust features without any artificial selection of features, and can capture the development trend of strong convective storm.

  10. True polar wander on convecting planets

    Science.gov (United States)

    Rose, Ian Robert

    Rotating planets are most stable when spinning around their maximum moment of inertia, and will tend to reorient themselves to achieve this configuration. Geological activity redistributes mass in the planet, making the moment of inertia a function of time. As the moment of inertia of the planet changes, the spin axis shifts with respect to a mantle reference frame in order to maintain rotational stability. This process is known as true polar wander (TPW). Of the processes that contribute to a planet's moment of inertia, convection in the mantle generates the largest and longest-period fluctuations, with corresponding shifts in the spin axis. True polar wander has been hypothesized to explain several physiographic features on planets and moons in our solar system. On Earth, TPW events have been invoked in some interpretations of paleomagnetic data. Large swings in the spin axis could have enormous ramifications for paleogeography, paleoclimate, and the history of life. Although the existence of TPW is well-verified, it is not known whether its rate and magnitude have been large enough for it to be an important process in Earth history. If true polar wander has been sluggish compared to plate tectonic speeds, then it would be difficult to detect and its consequences would be minor. I investigate rates of true polar wander on convecting planets using scaling, numerics, and inverse problems. I perform a scaling analysis of TPW on a convecting planet, identifying a minimal set of nondimensional parameters which describe the problem. The primary nondimensional numbers that control the rate of TPW are the ratio of centrifugal to gravitational forces m and the Rayleigh number Ra. The parameter m sets the size of a planet's rotational bulge, which determines the amount of work that needs to be done to move the spin axis. The Rayleigh number controls the size, distribution, and rate of change of moment of inertia anomalies, all of which affect the rate of TPW. I find that

  11. The role of mesoscale convective systems in the diurnal cycle of rainfall and its seasonality over sub-Saharan Northern Africa

    Science.gov (United States)

    Liu, Weiran; Cook, Kerry H.; Vizy, Edward K.

    2018-03-01

    This study evaluates the role of MCSs in the total rainfall distribution as a function of season from a climatological perspective (1998-2014) over sub-Saharan northern Africa and examines how the diurnal cycle of rainfall changes with season. Tropical Rainfall Measuring Mission (TRMM) 3B42V7 rainfall estimates and European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis are used to evaluate the climatology. The percentages of the full TRMM precipitation delivered by MCSs have meridional structures in spring, fall and winter, ranging from 0 to 80% across sub-Saharan northern Africa, while the percentages are homogenous in summer (> 80%). The diurnal cycles of MCS-associated precipitation coincide with the full TRMM rainfall. Attributes of MCSs, including size, count, and intensity, vary synchronously with the diurnal cycle of rainfall. The diurnal peaks are classified into three categories: single afternoon peak, continuous afternoon peak, and nocturnal peak. Single afternoon peaks dominate in spring and fall while continuous afternoon and nocturnal peaks are more common in summer, indicating the seasonality of the diurnal cycle. The continuous afternoon peak combines rainfall from two system types—one locally-generated and one propagating. The seasonality of the diurnal cycle is related to the seasonality of MCS lifetimes, and propagation speeds and directions. The moisture component of the MSE profile contributes to the instability most in summer when convection is more frequent. Low-level temperature, which is related to surface warming and sensible heat fluxes, influences the instability more during winter and spring.

  12. Conceptual design of bend, compression, and final focus components of ILSE [Induction Linac System Experiment

    International Nuclear Information System (INIS)

    Lee, E.P.; Fong, C.; Mukherjee, S.; Thur, W.

    1989-03-01

    The Induction Linac System Experiment (ILSE) includes a 180/degree/ bend system, drift compression line and a final focus, which test the analogous features of a heavy ion driver for inertial fusion. These components are novel in their transport of a space-charge-dominated ion beam with large head-to-tail velocity tilt. Their conceptual design is presented, including calculations of the beam envelope, momentum dispersion, and engineering design of magnets, vacuum system, diagnostics, alignment, and support. 3 refs., 5 figs

  13. Improved nowcasting of precipitation based on convective analysis fields

    Directory of Open Access Journals (Sweden)

    T. Haiden

    2007-04-01

    Full Text Available The high-resolution analysis and nowcasting system INCA (Integrated Nowcasting through Comprehensive Analysis developed at the Austrian national weather service provides three-dimensional fields of temperature, humidity, and wind on an hourly basis, and two-dimensional fields of precipitation rate in 15 min intervals. The system operates on a horizontal resolution of 1 km and a vertical resolution of 100–200 m. It combines surface station data, remote sensing data (radar, satellite, forecast fields of the numerical weather prediction model ALADIN, and high-resolution topographic data. An important application of the INCA system is nowcasting of convective precipitation. Based on fine-scale temperature, humidity, and wind analyses a number of convective analysis fields are routinely generated. These fields include convective boundary layer (CBL flow convergence and specific humidity, lifted condensation level (LCL, convective available potential energy (CAPE, convective inhibition (CIN, and various convective stability indices. Based on the verification of areal precipitation nowcasts it is shown that the pure translational forecast of convective cells can be improved by using a decision algorithm which is based on a subset of the above fields, combined with satellite products.

  14. Application of vertical micro-disk MHD electrode to the analysis of heterogeneous magneto-convection

    International Nuclear Information System (INIS)

    Sugiyama, Atsushi; Hashiride, Makoto; Morimoto, Ryoichi; Nagai, Yutaka; Aogaki, Ryoichi

    2004-01-01

    With a micro-disk electrode in vertical magnetic fields, heterogeneous magneto-convection in vertical magnetic fields was quantitatively examined for the redox reaction of ferrocyanide-ferricyanide ions. It was concluded that the current density controlled by the magneto-convection is in proportion to the 1/3rd power of the product of the magnetic flux density and its gradient. Then, by using the same electrode system, the diffusion current induced by the vertical MHD (magnetohydrodynamic) flow was measured for the reduction of cuprous ions to copper atoms. The current density in this case was, as theoretically predicted, a function of the 1st power of the magnetic flux density. Finally, to visualize this characteristic flow pattern of the vertical MHD flow, copper electrodeposition onto the micro-disk electrode in a vertical magnetic field was performed; a typical morphological pattern of the deposit (single micro-mystery circle) was observed, as expected

  15. Application of vertical micro-disk MHD electrode to the analysis of heterogeneous magneto-convection

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, A. [Saitama Industrial Technology Center, Japan Society for the Promotion of Science, Kawaguchi (Japan). Domestic Research Fellowship; Hashiride, M.; Morimoto, R.; Nagai, Y. [Saitama Industrial Technology Center, Kawaguchi (Japan). Materials Engineering Division; Aogaki, R. [Polytechnic University, Sagamihara (Japan). Department of Product Design

    2004-11-01

    With a micro-disk electrode in vertical magnetic fields, heterogeneous magneto-convection in vertical magnetic fields was quantitatively examined for the redox reaction of ferrocyanide-ferricyanide ions. It was concluded that the current density controlled by the magneto-convection is in proportion to the 1/3rd power of the product of the magnetic flux density and its gradient. Then, by using the same electrode system, the diffusion current induced by the vertical MHD (magnetohydrodynamic) flow was measured for the reduction of cuprous ions to copper atoms. The current density in this case was, as theoretically predicted, a function of the 1st power of the magnetic flux density. Finally, to visualize this characteristic flow pattern of the vertical MHD flow, copper electrodeposition onto the micro-disk electrode in a vertical magnetic field was performed; a typical morphological pattern of the deposit (single micro-mystery circle) was observed, as expected. (author)

  16. Oscillatory Convection in Rotating Liquid Metals

    Science.gov (United States)

    Bertin, Vincent; Grannan, Alex; Aurnou, Jonathan

    2016-11-01

    We have performed laboratory experiments in a aspect ratio Γ = 2 cylinder using liquid gallium (Pr = 0 . 023) as the working fluid. The Ekman number varies from E = 4 ×10-5 to 4 ×10-6 and the Rayleigh number varies from Ra = 3 ×105 to 2 ×107 . Using heat transfer and temperature measurements within the fluid, we characterize the different styles of low Pr rotating convective flow. The convection threshold is first overcome in the form of a container scale inertial oscillatory mode. At stronger forcing, wall-localized modes develop, coexisting with the inertial oscillatory modes in the bulk. When the strength of the buoyancy increases further, the bulk flow becomes turbulent while the wall modes remain. Our results imply that rotating convective flows in liquid metals do not develop in the form of quasi-steady columns, as in Pr = 1 planetary and stellar dynamo models, but in the form of oscillatory motions. Therefore, convection driven dynamo action in low Pr fluids can differ substantively than that occurring in typical Pr = 1 numerical models. Our results also suggest that low wavenumber, wall modes may be dynamically and observationally important in liquid metal dynamo systems. We thank the NSF Geophysics Program for support of this project.

  17. Comparative efficiency of final endodontic cleansing procedures in removing a radioactive albumin from root canal systems

    International Nuclear Information System (INIS)

    Cecic, P.A.; Peters, D.D.; Grower, M.F.

    1984-01-01

    Fifty-six teeth were initially instrumented, with the use of seven irrigants or irrigant combinations, and filled with radioactive albumin. The study then showed the relative ability of three final endodontic procedures (copious reirrigation with saline solution, drying with paper points, and reassuring patency of the canal with the final instrument) to remove the albumin. Even after copious irrigation, each additional procedure removed statistically significant amounts of albumin. Alternating an organic solvent and an inorganic solvent did appear to leave the canal system in the optimal condition for final cleansing procedures. The study then correlated the relative efficiency of irrigation alone versus instrumentation plus irrigation in removing the remaining albumin from the canal systems. Reinstrumentation plus copious irrigation removed significantly more albumin than copious irrigation alone

  18. Cryogenic forced convection refrigerating system

    International Nuclear Information System (INIS)

    Klee, D.J.

    1988-01-01

    This patent describes the method of refrigerating products by contact with a refrigerating gas which comprises introducing product into a refrigeration zone, contacting the product with the refrigerating gas for a sufficient time to refrigerate it to the appropriate extent and removing the refrigerated product. The improvement for producing the refrigeration gas from a liquid cryogen such that essentially all of the liquid cryogen is fully vaporized before contacting the product comprises: (a) introducing the liquid cryogen, selected from the group consisting of liquid air and liquid nitrogen, at elevated pressure into an ejector as the motive fluid to accelerate a portion of a warm refrigerating gas through the ejector while mixing the cryogen and gas to effect complete vaporization of the liquid cryogen and substantial cooling of the portion of the refrigerating gas resulting in a cold discharge gas which is above the liquefaction temperature of the cryogen; (b) introducing the cold discharge gas into a forced circulation pathway of refrigerating gas and producing a cold refrigerating gas which contacts and refrigerates product and is then at least partially recirculated; (c) sensing the temperature of the refrigerating gas in the forced circulation pathway and controlling the introduction of liquid cryogen with regard to the sensed temperature to maintain the temperature of the discharge gas above the liquefacton temperature of the cryogen utilized

  19. 75 FR 60632 - Hazardous Waste Management System; Identification and Listing of Hazardous Waste; Direct Final Rule

    Science.gov (United States)

    2010-10-01

    ... Waste Management System; Identification and Listing of Hazardous Waste; Direct Final Rule AGENCY... management and treatment of several F- and K-waste codes. These waste codes are F037, F038, K048, K049, K051... released from the waste, plausible and specific types of management of the petitioned waste, the quantities...

  20. Tank Waste Remediation System, Hanford Site, Richland, Washington. Final Environmental Impact Statement. Volume IV

    International Nuclear Information System (INIS)

    1996-08-01

    This document, Volume 4, describes the current safety concerns associated with the tank waste and analyzes the potential accidents and associated potential health effects that could occur under the alternatives included in this Tank Waste Remediation System (TWRS) Final Environmental Impact Statement (EIS) for the Hanford Site, Richland, Washington

  1. Columbia River system operation review. Final environmental impact statement. Appendix J, recreation

    International Nuclear Information System (INIS)

    1995-11-01

    This Appendix J of the Final Environmental Impact Statement for the Columbia River System discusses impacts on the recreational activities in the region. Major sections include the following: scope and processes; recreation in the Columbia River Basin today - by type, location, participation, user characteristics, factors which affect usage, and managing agencies; recreation analysis procedures and methodology; and alternatives and their impacts

  2. Columbia River System Operation Review : Final Environmental Impact Statement, Appendix J: Recreation.

    Energy Technology Data Exchange (ETDEWEB)

    Columbia River System Operation Review (U.S.)

    1995-11-01

    This Appendix J of the Final Environmental Impact Statement for the Columbia River System discusses impacts on the recreational activities in the region. Major sections include the following: scope and processes; recreation in the Columbia River Basin today - by type, location, participation, user characteristics, factors which affect usage, and managing agencies; recreation analysis procedures and methodology; and alternatives and their impacts.

  3. Convection in Porous Media

    CERN Document Server

    Nield, Donald A

    2013-01-01

    Convection in Porous Media, 4th Edition, provides a user-friendly introduction to the subject, covering a wide range of topics, such as fibrous insulation, geological strata, and catalytic reactors. The presentation is self-contained, requiring only routine mathematics and the basic elements of fluid mechanics and heat transfer. The book will be of use not only to researchers and practicing engineers as a review and reference, but also to graduate students and others entering the field. The new edition features approximately 1,750 new references and covers current research in nanofluids, cellular porous materials, strong heterogeneity, pulsating flow, and more. Recognized as the standard reference in the field Includes a comprehensive, 250-page reference list Cited over 2300 times to date in its various editions Serves as an introduction for those entering the field and as a comprehensive reference for experienced researchers Features new sections on nanofluids, carbon dioxide sequestration, and applications...

  4. Temperature-Driven Convection

    Science.gov (United States)

    Bohan, Richard J.; Vandegrift, Guy

    2003-02-01

    Warm air aloft is stable. This explains the lack of strong winds in a warm front and how nighttime radiative cooling can lead to motionless air that can trap smog. The stability of stratospheric air can be attributed to the fact that it is heated from above as ultraviolet radiation strikes the ozone layer. On the other hand, fluid heated from below is unstable and can lead to Bernard convection cells. This explains the generally turbulent nature of the troposphere, which receives a significant fraction of its heat directly from the Earth's warmer surface. The instability of cold fluid aloft explains the violent nature of a cold front, as well as the motion of Earth's magma, which is driven by radioactive heating deep within the Earth's mantle. This paper describes how both effects can be demonstrated using four standard beakers, ice, and a bit of food coloring.

  5. Convection in porous media

    CERN Document Server

    Nield, Donald A

    1992-01-01

    This book provides a user-friendly introduction to the topic of convection in porous media The authors as- sume that the reader is familiar with the basic elements of fluid mechanics and heat transfer, but otherwise the book is self-contained The book will be useful both as a review (for reference) and as a tutorial work, suitable as a textbook in a graduate course or seminar The book brings into perspective the voluminous research that has been performed during the last two decades The field has recently exploded because of worldwide concern with issues such as energy self-sufficiency and pollution of the environment Areas of application include the insulation of buildings and equipment, energy storage and recovery, geothermal reservoirs, nuclear waste disposal, chemical reactor engineering, and the storage of heat-generating materials such as grain and coal Geophysical applications range from the flow of groundwater around hot intrusions to the stability of snow against avalanches

  6. AN ANALYTIC RADIATIVE-CONVECTIVE MODEL FOR PLANETARY ATMOSPHERES

    International Nuclear Information System (INIS)

    Robinson, Tyler D.; Catling, David C.

    2012-01-01

    We present an analytic one-dimensional radiative-convective model of the thermal structure of planetary atmospheres. Our model assumes that thermal radiative transfer is gray and can be represented by the two-stream approximation. Model atmospheres are assumed to be in hydrostatic equilibrium, with a power-law scaling between the atmospheric pressure and the gray thermal optical depth. The convective portions of our models are taken to follow adiabats that account for condensation of volatiles through a scaling parameter to the dry adiabat. By combining these assumptions, we produce simple, analytic expressions that allow calculations of the atmospheric-pressure-temperature profile, as well as expressions for the profiles of thermal radiative flux and convective flux. We explore the general behaviors of our model. These investigations encompass (1) worlds where atmospheric attenuation of sunlight is weak, which we show tend to have relatively high radiative-convective boundaries; (2) worlds with some attenuation of sunlight throughout the atmosphere, which we show can produce either shallow or deep radiative-convective boundaries, depending on the strength of sunlight attenuation; and (3) strongly irradiated giant planets (including hot Jupiters), where we explore the conditions under which these worlds acquire detached convective regions in their mid-tropospheres. Finally, we validate our model and demonstrate its utility through comparisons to the average observed thermal structure of Venus, Jupiter, and Titan, and by comparing computed flux profiles to more complex models.

  7. On the mapping of ionospheric convection into the magnetosphere

    International Nuclear Information System (INIS)

    Hesse, M.; Birn, J.; Hoffman, R.A.

    1997-01-01

    Under steady state conditions and in the absence of parallel electric fields, ionospheric convection is a direct map of plasma and magnetic flux convection in the magnetosphere, and quantitative estimates can be obtained from the mapping along magnetic field lines of electrostatic ionospheric electric fields. The resulting magnetospheric electrostatic potential distribution then provides the convection electric field in various magnetospheric regions. We present a quantitative framework for the investigation of the applicability and limitations of this approach based on an analytical theory derived from first principles. Particular emphasis is on the role of parallel electric field regions and on inductive effects, such as expected during the growth and expansive phases of magnetospheric substorms. We derive quantitative estimates for the limits in which either effect leads to a significant decoupling between ionospheric and magnetospheric convection and provide an interpretation of ionospheric convection which is independent of the presence of inductive electric fields elsewhere in the magnetosphere. Finally, we present a study of the relation between average and instantaneous convection, using two periodic dynamical models. The models demonstrate and quantify the potential mismatch between the average electric fields in the ionosphere and the magnetosphere in strongly time-dependent cases that may exist even when they are governed entirely by ideal MHD

  8. Fused Silica Final Optics for Inertial Fusion Energy: Radiation Studies and System-Level Analysis

    International Nuclear Information System (INIS)

    Latkowski, Jeffery F.; Kubota, Alison; Caturla, Maria J.; Dixit, Sham N.; Speth, Joel A.; Payne, Stephen A.

    2003-01-01

    The survivability of the final optic, which must sit in the line of sight of high-energy neutrons and gamma rays, is a key issue for any laser-driven inertial fusion energy (IFE) concept. Previous work has concentrated on the use of reflective optics. Here, we introduce and analyze the use of a transmissive final optic for the IFE application. Our experimental work has been conducted at a range of doses and dose rates, including those comparable to the conditions at the IFE final optic. The experimental work, in conjunction with detailed analysis, suggests that a thin, fused silica Fresnel lens may be an attractive option when used at a wavelength of 351 nm. Our measurements and molecular dynamics simulations provide convincing evidence that the radiation damage, which leads to optical absorption, not only saturates but that a 'radiation annealing' effect is observed. A system-level description is provided, including Fresnel lens and phase plate designs

  9. Stellar convection and dynamo theory

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, R L

    1989-10-01

    In considering the large scale stellar convection problem the outer layers of a star are modelled as two co-rotating plane layers coupled at a fluid/fluid interface. Heating from below causes only the upper fluid to convect, although this convection can penetrate into the lower fluid. Stability analysis is then used to find the most unstable mode of convection. With parameters appropriate to the Sun the most unstable mode is steady convection in thin cells (aspect ratio {approx equal} 0.2) filling the convection zone. There is negligible vertical motion in the lower fluid, but considerable thermal penetration, and a large jump in helicity at the interface, which has implications for dynamo theory. An {alpha}{omega} dynamo is investigated in isolation from the convection problem. Complexity is included by allowing both latitudinal and time dependence in the magnetic fields. The nonlinear dynamics of the resulting partial differential equations are analysed in considerable detail. On varying the main control parameter D (the dynamo number), many transitions of behaviour are found involving many forms of time dependence, but not chaos. Further, solutions which break equatorial symmetry are common and provide a theoretical explanation of solar observations which have this symmetry. Overall the behaviour was more complicated than expected. In particular, there were multiple stable solutions at fixed D, meaning that similar stars can have very different magnetic patterns, depending upon their history. (author).

  10. Radiation damage and waste management options for the sombrero final focus system and neutron dumps

    International Nuclear Information System (INIS)

    Reyes, S.; Latkowski, J.F.; Meier, W.R.; Reyes, S.

    2000-01-01

    Previous studies of the safety and environmental aspects of the SOMBRERO inertial fusion energy (IFE) power plant design did not completely address the issues associated with the final focus system. While past work calculated neutron fluences for a grazing incidence metal mirror (GIMM) and a final focus mirror, scattering off of the final optical component was not included, and thus, fluences in the final focus mirror were significantly underestimated. In addition, past work did not consider neutron-induced gamma-rays. Finally, power plant lifetime waste volumes may have been underestimated as neutron activation of the neutron dumps and building structure were not addressed. In the present work, a modified version of the SOMBRERO target building is presented where a significantly larger open solid-angle fraction (5%) is used to enhance beam smoothing of a diode-pumped solid-state laser (DPSSL). The GIMMs are replaced with transmissive fused silica wedges and have been included in three-dimensional neutron and photon transport calculations. This work shows that a power plant with a large open solid-angle fraction, needed for beam smoothing with a DPSSL, is acceptable from tritium breeding, and neutron activation points-of-view. (authors)

  11. Convective parameters in fuel elements for research nuclear reactors

    International Nuclear Information System (INIS)

    Lopez Martinez, C.D.

    1992-01-01

    The study of a prototype for the simulation of fuel elements for research nuclear reactors by natural convection in water is presented in this paper. This project is carry out in the thermofluids laboratory of National Institute of Nuclear Research. The fuel prototype has already been test for natural convection in air, and the first results in water are presented in this work. In chapter I, a general description of Triga Mark III is made, paying special atention to fuel-moderator components. In chapter II and III an approach to convection subject in its global aspects is made, since the intention is to give a general idea of the events occuring around fuel elements in a nuclear reactor. In chapter II, where an emphasis on forced convection is made, some basic concepts for forced convection as well as for natural convection are included. The subject of flow through cylinders is annotated only as a comparative reference with natural convection in vertical cylinders, noting the difference between used correlations and the involved variables. In chapter III a compilation of correlation found in the bibliography about natural convection in vertical cylinders is presented, since its geometry is the more suitable in the analysis of a fuel rod. Finally, in chapter IV performed experiments in the test bench are detailed, and the results are presented in form of tables and graphs, showing the used equations for the calculations and the restrictions used in each case. For the analysis of the prototypes used in the test bench, a constant and uniform flow of heat in the whole length of the fuel rod is considered. At the end of this chapter, the work conclusions and a brief explanation of the results are presented (Author)

  12. Columbia River System Operation Review : Final Environmental Impact Statement, Main Report Exhibits.

    Energy Technology Data Exchange (ETDEWEB)

    Columbia River System Operation Review (U.S.)

    1995-11-01

    This Volume is a part of the Final Environmental Impact Statement (EIS) for the Columbia River System. This volume contains technical exhibits of cultural resources and commentary on the (System Operation Review) SOR process. The Confederated Tribes of the Umatilla Indian Reservation comment is the majority of the material in the volume, in the Consultation Plan, Identification of trust resources; Criteria for the selection of a System Operating Strategy; comment on rights protection and implementation of Federal Trust responsibility; analysis of the draft EIS. Comment by other Native American Tribes and groups is also included: Confederated Tribes of the Colville Reservation; Kootenai Tribe of Idaho; Spokane Tribe of Indians; Coeur d` Alene tribe.

  13. Radiation Hardened Telerobotic Dismantling System Development Final Report CRADA No. TC-1340-96

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lightman, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-27

    This project was a collaborative effort between the University of California, LLNL and RedZone Robotics, Inc. for the development of radiation-hardened telerobotic dismantling systems for use in applications such as nuclear facility remediation, nuclear accident response, and Chemobyltype remediation. The project supported the design, development, fabrication and testing of a Ukrainian robotic systems. The project was completed on time and within budget. All deliverables were completed. The final project deliverables were consistent with the plans developed in the original project with the exception that the fabricated systems remained in Ukraine.

  14. Columbia River system operation review: Final environmental impact statement. Main report exhibits

    International Nuclear Information System (INIS)

    1995-11-01

    This Volume is a part of the Final Environmental Impact Statement (EIS) for the Columbia River System. This volume contains technical exhibits of cultural resources and commentary on the (System Operation Review) SOR process. The Confederated Tribes of the Umatilla Indian Reservation comment is the majority of the material in the volume, in the Consultation Plan, Identification of trust resources; Criteria for the selection of a System Operating Strategy; comment on rights protection and implementation of Federal Trust responsibility; analysis of the draft EIS. Comment by other Native American Tribes and groups is also included: Confederated Tribes of the Colville Reservation; Kootenai Tribe of Idaho; Spokane Tribe of Indians; Coeur d' Alene tribe

  15. Large Eddy Simulations of Severe Convection Induced Turbulence

    Science.gov (United States)

    Ahmad, Nash'at; Proctor, Fred

    2011-01-01

    Convective storms can pose a serious risk to aviation operations since they are often accompanied by turbulence, heavy rain, hail, icing, lightning, strong winds, and poor visibility. They can cause major delays in air traffic due to the re-routing of flights, and by disrupting operations at the airports in the vicinity of the storm system. In this study, the Terminal Area Simulation System is used to simulate five different convective events ranging from a mesoscale convective complex to isolated storms. The occurrence of convection induced turbulence is analyzed from these simulations. The validation of model results with the radar data and other observations is reported and an aircraft-centric turbulence hazard metric calculated for each case is discussed. The turbulence analysis showed that large pockets of significant turbulence hazard can be found in regions of low radar reflectivity. Moderate and severe turbulence was often found in building cumulus turrets and overshooting tops.

  16. Marine Tactical Command and Control System (MTACCS) Field Development System-1 (FDS-1) assessment: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Avery, L.W.; Hunt, S.T.; Savage, S.F. (Pacific Northwest Lab., Richland, WA (United States)); McLaughlin, P.D.; Shepdard, A.P.; Worl, J.C. (Battelle Seattle Research Center, WA (United States))

    1992-04-01

    The United State Marine Corps (USMC) is continuing the development and fielding of the Marine Corps Tactical Command and Control System (MTACCS), a system which exists in varying states of development, fielding, or modernization. MTACCS is currently composed of the following components: Tactical Combat Operations System (TCO) for ground command and control (C2), Intelligence Analysis System (IAS) with a Genser terminal connected to a TCO workstation for intelligence C2, Marine Integrated Personnel System (MIPS) and a TCO workstation using the Marine Combat Personnel System (MCPERS) software for personnel C2, Marine Integrated Logistics System (MILOGS) which is composed of the Landing Force Asset Distribution System (LFADS), the Marine Air-Ground Task Force (MAGTF) II, and a TCO terminal using the Marine Combat Logistics System (MCLOG) for logistics C2, Marine Corps Fire Support System (MCFSS) for fire support C2, and Advanced Tactical Air Command Central (ATACC) and the Improved Direct Air Support Central for aviation C2.

  17. Fusing Multiple Satellite Datasets Toward Defining and Understanding Organized Convection

    Science.gov (United States)

    Elsaesser, G.; Del Genio, A. D.

    2017-12-01

    How do we differentiate unorganized from organized convection? We might think of organized convection as being long lasting (at least longer than the lifetime of any individual cumulus cell), clustered at larger spatial scales (>100 km), and responsible for substantial rainfall accumulation. Organized convection is sustained on such scales due to the arrangement of moist/dry and buoyant/non-buoyant mesoscale circulations. The nature of these circulations is tied to system diabatic heating profiles; in particular, the 2nd baroclinic (top-heavy), stratiform heating mode is thought to be important for organized convection maintenance/propagation. We investigate the extent to which these characteristics are jointly found in propagating convective systems. Lifecycle information comes from hi-res IR data. Diabatic heating profiles, convective fractions and rainfall are provided by GPM retrievals mapped to convective system tracks. Moisture is provided by AIRS/AMSU and passive microwave retrievals. Instead of compositing heating profile information along a system track, where information is smoothed out, we sort system heating profile structures according to their "top heaviness" and then analyze PDFs of system rainfall, system sizes, durations, convective/stratiform ratios, etc. as a function of diabatic heating structure. Perhaps contrary to expectation, we find only small differences in PDFs of rainfall rates, system sizes, and system duration for different heating profile structures. If organization is defined according to heating structures, then one possible interpretation of these results is that organization is independent of system size, duration, and many times, even lifecycle stage. Is it possible that most systems "hobble" along and exhibit varying degrees of organization, dependent on local environment moisture/buoyancy variations, unlike the archetypical MCS paradigm? This presentation will also discuss the questions posed above within the context of

  18. Research and development on super heat pump energy accumulation system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-06-01

    This is the final report on research and development of super heat pump energy accumulation system, which has been carried out from FY 1985 to 1992. It describes outline of the research and development program, R and D results, final evaluation methodology, evaluation of the R and D, proposals for the commercialization, and so on. The super high performance compression heat pumps are technically evaluated for highly efficient type (for heating, and cooling and heating), high temperature type (utilizing high temperature heat source, and low temperature heat source), working fluids (alcohol-based and nonalcohol-based), stainless steel plate fin type heat exchanger, EHD heat exchanger, and so on. The other techniques evaluated include those for chemical heat storage, combined systems, plant simulation, and systemization. The evaluation works are also directed to the economic and environmental aspects. Finally, the R and D themes are proposed to leap over various hurdles, e.g., reliability and economic viability, for the eventual commercialization of the energy accumulation system. (NEDO)

  19. The first stage of BFS integrated system for nuclear materials control and accounting. Final report

    International Nuclear Information System (INIS)

    1996-09-01

    The BFS computerized accounting system is a network-based one. It runs in a client/server mode. The equipment used in the system includes a computer network consisting of: One server computer system, including peripheral hardware and three client computer systems. The server is located near the control room of the BFS-2 facility outside of the 'stone sack' to ensure access during operation of the critical assemblies. Two of the client computer systems are located near the assembly tables of the BFS-1 and BFS-2 facilities while the third one being the Fissile Material Storage. This final report details the following topics: Computerized nuclear material accounting methods; The portal monitoring system; Test and evaluation of item control technology; Test and evaluation of radiation based nuclear material measurement equipment; and The integrated demonstration of nuclear material control and accounting methods

  20. The convection patterns in microemulsions

    International Nuclear Information System (INIS)

    Korneta, W.; Lopez Quintela, M.A.; Fernandez Novoa, A.

    1991-07-01

    The Rayleigh-Benard convection in the microemulsion consisting of water (7.5%), cyclohexan (oil-61.7%) and diethylenglycolmonobutylether (surfactant-30.8%) is studied from the onset of convection to the phase separation. The five classes of convection patterns are observed and recorded on the video: localized travelling waves, travelling waves, travelling waves and localized steady rolls, steady rolls and steady polygons. The Fourier transforms and histograms of these patterns are presented. The origin of any pattern is discussed. The intermittent behaviour close to the phase separation was observed. Possible applications of the obtained results are suggested. (author). 6 refs, 4 figs

  1. Analysis and modeling of tropical convection observed by CYGNSS

    Science.gov (United States)

    Lang, T. J.; Li, X.; Roberts, J. B.; Mecikalski, J. R.

    2017-12-01

    The Cyclone Global Navigation Satellite System (CYGNSS) is a multi-satellite constellation that utilizes Global Positioning System (GPS) reflectometry to retrieve near-surface wind speeds over the ocean. While CYGNSS is primarily aimed at measuring wind speeds in tropical cyclones, our research has established that the mission may also provide valuable insight into the relationships between wind-driven surface fluxes and general tropical oceanic convection. Currently, we are examining organized tropical convection using a mixture of CYGNSS level 1 through level 3 data, IMERG (Integrated Multi-satellite Retrievals for Global Precipitation Measurement), and other ancillary datasets (including buoys, GPM level 1 and 2 data, as well as ground-based radar). In addition, observing system experiments (OSEs) are being performed using hybrid three-dimensional variational assimilation to ingest CYGNSS observations into a limited-domain, convection-resolving model. Our focus for now is on case studies of convective evolution, but we will also report on progress toward statistical analysis of convection sampled by CYGNSS. Our working hypothesis is that the typical mature phase of organized tropical convection is marked by the development of a sharp gust-front boundary from an originally spatially broader but weaker wind speed change associated with precipitation. This increase in the wind gradient, which we demonstrate is observable by CYGNSS, likely helps to focus enhanced turbulent fluxes of convection-sustaining heat and moisture near the leading edge of the convective system where they are more easily ingested by the updraft. Progress on the testing and refinement of this hypothesis, using a mixture of observations and modeling, will be reported.

  2. Scaling of Convection and Plate Tectonics in Super-Earths

    Science.gov (United States)

    Valencia, D. C.; O'Connell, R. J.; Sasselov, D. D.

    2006-12-01

    The discovery of three Super-Earths around different stars, possible only in the last year, prompts us to study the characteristics of our planet within a general context. The Earth, being the most massive terrestrial object in the solar system is the only planet that exhibits plate tectonics. We think this might not be a coincidence and explore the role that mass plays in determining the mode of convection. We use the scaling of convective vigor with Rayleigh number commonly used in parameterized convection. We study how the parameters controlling convection: Rayleigh number (Ra), boundary layer thickness (δ), internal temperature (T_i) and convective velocities (u) scale with mass. This is possible from the scaling of heat flux, mantle density, size and gravity with mass which we reported in Valencia, et. al 2006. The extrapolation to massive rocky planets is done from our knowledge of the Earth. Even though uncertainties arise from extrapolation and assumptions are needed we consider this simple scaling to be a first adequate step. As the mass of a planet increases, Ra increases, yielding a decrease in δ and an increase in u, while T_i increases very slightly. This is true for an isoviscous case and is more accentuated in a temperature dependent viscosity scenario. In a planet with vigorous convection (high u), a thin lithosphere (low δ) is easier to subduct and hence, initiate plate tectonics. The lithosphere also has to be dense enough (cold and thick) to have the bouyancy necessary for subduction. We calculate that a convective cycle for an isoviscous planet is τ ~ M^{-0.3} considering whole mantle convection. Meaning that if these planets have continents, the timescale for continental rearrangement is shorter (about half the Earth's for a 5 earth-mass planet). Additionally, we explore the negative feedback cycle between convection and temperature dependent viscosity and estimate a timescale for this effect.

  3. Instabilities in fluid layers and in reaction-diffusion systems: Steady states, time-periodic solutions, non-periodic attractors, and related convective and otherwise non-linear phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Velarde, M

    1977-07-01

    Thermo convective instabilities in horizontal fluid layers are discussed with emphasis on the Rayleigh-Bernard model problem. Steady solutions and time-dependent phenomena (relaxation oscillations and transition to turbulence) are studied within the nonlinear Boussinesq-Oberbeck approximation. Homogeneous steady solutions, limit cycles, and inhomogeneous (ordered) spatial structures are also studied in simple reaction-diffusion systems. Lastly, the non-periodic attractor that appears at large Rayleigh numbers in the truncated Boussinesq-Oberbeck model of Lorenz, is constructed, and a discussion of turbulent behavior is given. (Author) 105 refs.

  4. Instabilities in fluid layers and in reaction-diffusion systems: Steady states, time-periodic solutions, non-periodic attractors, and related convective and otherwise non-linear phenomena

    International Nuclear Information System (INIS)

    Garcia Velarde, M.

    1977-01-01

    Thermo convective instabilities in horizontal fluid layers are discussed with emphasis on the Rayleigh-Bernard model problem. Steady solutions and time-dependent phenomena (relaxation oscillations and transition to turbulence) are studied within the nonlinear Boussinesq-Oberbeck approximation. Homogeneous steady solutions, limit cycles, and inhomogeneous (ordered) spatial structures are also studied in simple reaction-diffusion systems. Lastly, the non-periodic attractor that appears at large Rayleigh numbers in the truncated Boussinesq-Oberbeck model of Lorenz, is constructed, and a discussion of turbulent behavior is given. (Author) 105 refs

  5. Hybrid FRP-concrete bridge deck system final report I : development and system performance validation.

    Science.gov (United States)

    2009-10-01

    In this study, the concept of the hybrid FRP-concrete structural systems was applied to both bridge : superstructure and deck systems. Results from the both experimental and computational analysis for : both the hybrid bridge superstructure and deck ...

  6. Heat pump centered integrated community energy systems: system development. Georgia Institute of Technology final report

    Energy Technology Data Exchange (ETDEWEB)

    Wade, D.W.; Trammell, B.C.; Dixit, B.S.; McCurry, D.C.; Rindt, B.A.

    1979-12-01

    Heat Pump Centered-Integrated Community Energy Systems (HP-ICES) show the promise of utilizing low-grade thermal energy for low-quality energy requirements such as space heating and cooling. The Heat Pump - Wastewater Heat Recovery (HP-WHR) scheme is one approach to an HP-ICES that proposes to reclaim low-grade thermal energy from a community's wastewater effluent. This report develops the concept of an HP-WHR system, evaluates the potential performance and economics of such a system, and examines the potential for application. A thermodynamic performance analysis of a hypothetical system projects an overall system Coefficient of Performance (C.O.P.) of from 2.181 to 2.264 for waste-water temperatures varying from 50/sup 0/F to 80/sup 0/F. Primary energy source savings from the nationwide implementation of this system is projected to be 6.0 QUADS-fuel oil, or 8.5 QUADS - natural gas, or 29.7 QUADS - coal for the period 1980 to 2000, depending upon the type and mix of conventional space conditioning systems which could be displaced with the HP-WHR system. Site-specific HP-WHR system designs are presented for two application communities in Georgia. Performance analyses for these systems project annual cycle system C.O.P.'s of 2.049 and 2.519. Economic analysis on the basis of a life cycle cost comparison shows one site-specific system design to be cost competitive in the immediate market with conventional residential and light commercial HVAC systems. The second site-specific system design is shown through a similar economic analysis to be more costly than conventional systems due mainly to the current low energy costs for natural gas. It is anticipated that, as energy costs escalate, this HP-WHR system will also approach the threshold of economic viability.

  7. Global Navigation Satellite System (GNSS) Final Clock Product (5 minute resolution, daily files, generated weekly) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This derived product set consists of Global Navigation Satellite System Final Satellite and Receiver Clock Product (5-minute granularity, daily files, generated...

  8. Nonlinear Convective Models of RR Lyrae Stars

    Science.gov (United States)

    Feuchtinger, M.; Dorfi, E. A.

    The nonlinear behavior of RR Lyrae pulsations is investigated using a state-of-the-art numerical technique solving the full time-dependent system of radiation hydrodynamics. Grey radiative transfer is included by a variable Eddington-factor method and we use the time-dependent turbulent convection model according to Kuhfuss (1986, A&A 160, 116) in the version of Wuchterl (1995, Comp. Phys. Comm. 89, 19). OPAL opacities extended by the Alexander molecule opacities at temperatures below 6000 K and an equation of state according to Wuchterl (1990, A&A 238, 83) close the system. The resulting nonlinear system is discretized on an adaptive mesh developed by Dorfi & Drury (1987, J. Comp. Phys. 69, 175), which is important to provide the necessary spatial resolution in critical regions like ionization zones and shock waves. Additionally, we employ a second order advection scheme, a time centered temporal discretizaton and an artificial tensor viscosity in order to treat discontinuities. We compute fundamental as well first overtone models of RR Lyrae stars for a grid of stellar parameters both with and without convective energy transport in order to give a detailed picture of the pulsation-convection interaction. In order to investigate the influence of the different features of the convection model calculations with and without overshooting, turbulent pressure and turbulent viscosity are performed and compared with each other. A standard Fourier decomposition is used to confront the resulting light and radial velocity variations with recent observations and we show that the well known RR Lyrae phase discrepancy problem (Simon 1985, ApJ 299, 723) can be resolved with these stellar pulsation computations.

  9. Operational experience with optical matching in the SLC Final Focus System

    International Nuclear Information System (INIS)

    Bambade, P.; Burchat, P.; Burke, D.

    1989-01-01

    In the SLC Final Focus System, all components of transverse phase-space and the couplings between them must be controlled to minimize the beam size at the interaction point. After summarizing the experimental algorithm and the on-line tuning programs, we present a consistent set of measurements and describe our present understanding of the various contributions to this beam size. 17 refs., 9 figs

  10. Final Environmental Assessment for a Solar Power System at Davis-Monthan Air Force Tucson, Arizona

    Science.gov (United States)

    2009-09-01

    to the following factors depending on the corresponding years. Year 2005 through 2009: VOCE = .016 * Trips NOxE = .015 * Trips PM10E = .0022...Trips COE = .262 * Trips Year 2010 and beyond: VOCE = .012 * Trips NOxE = .013 * Trips PM10E = .0022 * Trips COE = .262 * Trips FINAL...ENVIRONMENTAL ASSESSMENT B-8 Solar Power System (SPS) at Davis-Monthan AFB To convert from pounds per day to tons per year: VOC (tons/yr) = VOCE * DPYII/2000

  11. Commercialization of PV-powered pumping systems for use in utility PV service programs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The project described in this report was a commercialization effort focused on cost-effective remote water pumping systems for use in utility-based photovoltaic (PV) service programs. The project combined a commercialization strategy tailored specifically for electric utilities with the development of a PV-powered pumping system that operates conventional ac pumps rather than relying on the more expensive and less reliable PV pumps on the market. By combining these two attributes, a project goal was established of creating sustained utility purchases of 250 PV-powered water pumping systems per year. The results of each of these tasks are presented in two parts contained in this Final Summary Report. The first part summarizes the results of the Photovoltaic Services Network (PSN) as a new business venture, while the second part summarizes the results of the Golden Photon system installations. Specifically, results and photographs from each of the system installations are presented in this latter part.

  12. Columbia River System Operation Review final environmental impact statement. Appendix T: Comments and responses

    International Nuclear Information System (INIS)

    1995-11-01

    The System Operation Review (SOR) is a study and environmental compliance process being used by the three Federal agencies to analyze future operations of the system and river use issues. The goal of the SOR is to achieve a coordinated system operation strategy for the river that better meets the needs of all river users. This technical appendix addresses only the effects of alternative system operating strategies for managing the Columbia River system. This appendix documents the public and agency review of the SOR Draft EIS and how the SOR agencies used the review to formulate the FINAL EIS. The appendix includes a summary of the review process, a discussion of the nature of the comments, a list of all commentors, reproductions of comment letters, and responses to all comments. Changes in the EIS text in response to comments are noted in the responses

  13. Solar heating system installed at Telex Communications, Inc. , Blue Earth, Minnesota. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McEver, William S.

    1979-10-26

    The final results are summarized of a contract for space heating a 97,000 square foot building which houses administrative offices, assembly areas and warehouse space. Information is also provided on system description, test data, major problems and resolutions, performance, operation and maintenance manual, manufacturer's literature, and as-built drawings. The system began delivering space heating in February 1978. The Telex solar system is composed of four main subsystems; they are the solar collectors, controls, thermal storage and heat distribution. The ITC/Solar Mark III collector was used. The collector array consists of 10 rows of 36 collectors each. The control subsystem controls the operation of the system pumps and control valves. Thermal storage for the system is provided by a 20,000 gallon water storage tank located inside the building. Heating is accomplished by water-to-air heat exchangers and controlled by thermostats.

  14. Convection in the Labrador Sea

    National Research Council Canada - National Science Library

    Davis, R

    1997-01-01

    The long-term goal of this grant was to describe the process of deep oceanic convection well enough to provide critical tests of, and guidance to, models used to predict subsurface ocean conditions...

  15. Convective heat flow probe

    Science.gov (United States)

    Dunn, James C.; Hardee, Harry C.; Striker, Richard P.

    1985-01-01

    A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packer-type seals are provided along the probe above and below the heater pads.

  16. Quantitative adaptation analytics for assessing dynamic systems of systems: LDRD Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, John H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). System Readiness & Sustainment Technologies (6133, M/S 1188); Miner, Nadine E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Military & Energy Systems Analysis (6114, M/S 1188); Wilson, Michael L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Resilience and Regulatory Effects (6921, M/S 1138); Le, Hai D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). System Readiness & Sustainment Technologies (6133, M/S 1188); Kao, Gio K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Networked System Survivability & Assurance (5629, M/S 0671); Melander, Darryl J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Software Systems R& D (9525, M/S 1188); Longsine, Dennis Earl [Sandia National Laboratories, Unknown, Unknown; Vander Meer, Jr., Robert C. [SAIC, Inc., Albuquerque, NM (United States)

    2015-01-01

    Our society is increasingly reliant on systems and interoperating collections of systems, known as systems of systems (SoS). These SoS are often subject to changing missions (e.g., nation- building, arms-control treaties), threats (e.g., asymmetric warfare, terrorism), natural environments (e.g., climate, weather, natural disasters) and budgets. How well can SoS adapt to these types of dynamic conditions? This report details the results of a three year Laboratory Directed Research and Development (LDRD) project aimed at developing metrics and methodologies for quantifying the adaptability of systems and SoS. Work products include: derivation of a set of adaptability metrics, a method for combining the metrics into a system of systems adaptability index (SoSAI) used to compare adaptability of SoS designs, development of a prototype dynamic SoS (proto-dSoS) simulation environment which provides the ability to investigate the validity of the adaptability metric set, and two test cases that evaluate the usefulness of a subset of the adaptability metrics and SoSAI for distinguishing good from poor adaptability in a SoS. Intellectual property results include three patents pending: A Method For Quantifying Relative System Adaptability, Method for Evaluating System Performance, and A Method for Determining Systems Re-Tasking.

  17. Re-Engineering Casting Production Systems - Final Report - 03/02/1998 - 03/01/2001; FINAL

    International Nuclear Information System (INIS)

    Peters, Frank; Van Voorhis, Timothy

    2001-01-01

    The goal of this three-year project was to improve the production systems in use by steel foundries in the United States. Improvements in the production systems result in less rework, less scrap, and less material handling, all of which would significantly reduce the energy demands of the process. Furthermore, these improvements would allow the companies to be more competitive, more responsive to customers' needs, deliver products with less lead time and require less capital. The ultimate result is a stronger domestic steel casting industry, which uses less energy. A major portion of this research involved the deployment of student researchers at steel foundries, to study their production systems and collect data

  18. Convection-enhanced water evaporation

    OpenAIRE

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

    2011-01-01

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

  19. The proposed alignment system for the Final Focus Test Beam at SLAC

    International Nuclear Information System (INIS)

    Ruland, R.E.; Fischer, G.E.

    1990-09-01

    This report describes the current state of work in progress with respect to the geometry, alignment requirements, scenarios, and hardware for meeting the tolerances of the Final Focus Test Beam (FFTB) at SLAC. The methods and systems proposed acknowledge that component motion at the micron level, from whatever cause (ground motion, thermal effects, etc.) must be measured on-line and compensated for on relatively short time scales. To provide an integrated alignment/positioning package, some unique designs for reference systems, calibration of effect electric and magnetic centers, and component movers are introduced. 24 refs., 28 figs

  20. Modeling mantle convection in the spherical annulus

    Science.gov (United States)

    Hernlund, John W.; Tackley, Paul J.

    2008-12-01

    Most methods for modeling mantle convection in a two-dimensional (2D) circular annular domain suffer from innate shortcomings in their ability to capture several characteristics of the spherical shell geometry of planetary mantles. While methods such as rescaling the inner and outer radius to reduce anomalous effects in a 2D polar cylindrical coordinate system have been introduced and widely implemented, such fixes may have other drawbacks that adversely affect the outcome of some kinds of mantle convection studies. Here we propose a new approach that we term the "spherical annulus," which is a 2D slice that bisects the spherical shell and is quantitatively formulated at the equator of a spherical polar coordinate system after neglecting terms in the governing equations related to variations in latitude. Spherical scaling is retained in this approximation since the Jacobian function remains proportional to the square of the radius. We present example calculations to show that the behavior of convection in the spherical annulus compares favorably against calculations performed in other 2D annular domains when measured relative to those in a fully three-dimensional (3D) spherical shell.

  1. Regime-dependent forecast uncertainty of convective precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Keil, Christian; Craig, George C. [Muenchen Univ. (Germany). Meteorologisches Inst.

    2011-04-15

    Forecast uncertainty of convective precipitation is influenced by all scales, but in different ways in different meteorological situations. Forecasts of the high resolution ensemble prediction system COSMO-DE-EPS of Deutscher Wetterdienst (DWD) are used to examine the dominant sources of uncertainty of convective precipitation. A validation with radar data using traditional as well as spatial verification measures highlights differences in precipitation forecast performance in differing weather regimes. When the forecast uncertainty can primarily be associated with local, small-scale processes individual members run with the same variation of the physical parameterisation driven by different global models outperform all other ensemble members. In contrast when the precipitation is governed by the large-scale flow all ensemble members perform similarly. Application of the convective adjustment time scale confirms this separation and shows a regime-dependent forecast uncertainty of convective precipitation. (orig.)

  2. An experimental study of mixed convection

    International Nuclear Information System (INIS)

    Saez, Manuel

    1998-01-01

    The aim of our study is to establish a reliable data base for improving thermal-hydraulic codes, in the field of turbulent flows with buoyancy forces. The flow considered is mixed convection in the Reynolds and Richardson number range: Re=10"3 to 6*10"4 and Ri=10"-"4 to 1. Experiments are carried out in an upward turbulent flow between vertical parallel plates at different wall temperatures. Part 1 gives a detailed data base of turbulent mixed flow of free and forced convection. Part II presents the installation and the calibration system intended for probes calibration. Part III describes the measurement technique (constant-temperature probe and cold-wire probe) and the method for measuring the position of the hot-wire anemometer from the wall surface. The measurement accuracy is within 0.001 mm in the present system. Part IV relates the development of a method for near wall measurements. This correction procedure for hot-wire anemometer close to wall has been derived on the basis of a two-dimensional numerical study. The method permits to obtain a quantitative correction of the wall influence on hot-wires and takes into account the velocity profile and the effects the wall material has on the heat loss. Part V presents the experimental data obtained in the channel in forced and mixed convection. Results obtained in the forced convection regime serve as a verification of the measurement technique close to the wall and give the conditions at the entrance of the test section. The effects of the buoyancy force on the mean velocity and temperature profiles are confirmed. The buoyancy strongly affects the flow structure and deforms the distribution of mean velocity. The velocity profiles are asymmetric. The second section of part V gives an approach of analytical wall functions with buoyancy forces, on the basis of the experimental data obtained in the test section. (author) [fr

  3. Final Report for File System Support for Burst Buffers on HPC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yu, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mohror, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-11-27

    Distributed burst buffers are a promising storage architecture for handling I/O workloads for exascale computing. As they are being deployed on more supercomputers, a file system that efficiently manages these burst buffers for fast I/O operations carries great consequence. Over the past year, FSU team has undertaken several efforts to design, prototype and evaluate distributed file systems for burst buffers on HPC systems. These include MetaKV: a Key-Value Store for Metadata Management of Distributed Burst Buffers, a user-level file system with multiple backends, and a specialized file system for large datasets of deep neural networks. Our progress for these respective efforts are elaborated further in this report.

  4. Two-component air heating system. Final report. Zweikomponenten-Luftheizungs-System. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, W; Thiel, D

    1986-01-01

    The two-component heating system consists of a combination of air-based floor heating and direct air heating, with ventilation and extraction and heat recovery. The direct airflow consists exclusively of heated outside air, the amount corresponding to the building's external air intake requirement. The control system comprises a two-step sequential control of the air throughput of the direct air heating system and of the air distribution for the floor heating airflow. A special heating switch makes it possible to switch off the direct air heating system separately, and to select rapid warm-up. The way in which the new heating system works has been tested in a pilot set-up and proven by comprehensive measurements. In addition, a simulation model was produced which gave substantial confirmation of the measurements. (orig.) With 9 refs., 37 tabs., 63 figs.

  5. Evenly-spaced columns in the Bishop Tuff as relicts of hydrothermal convection

    Science.gov (United States)

    Randolph-Flagg, N. G.; Breen, S. J.; Hernandez, A.; Self, S.; Manga, M.

    2015-12-01

    A few square km of the Bishop Tuff in eastern California, USA have evenly spaced erosional columns. These columns are more resistant to erosion due to the precipitation of the low-temperature zeolite (120-200 ºC), mordenite, which is not found in the surrounding tuff. Similar features observed in the Bandelier Tuff were hypothesized to form when cold water from above infiltrated into the still-hot tuff interior. This water would become gravitationally unstable and produced convection with steam upwellings and liquid water downwellings. These downwellings became cemented with mordenite while the upwellings were too dry for chemical reactions. We use two methods to quantitatively assess this hypothesis. First, scaling that ignores the effects of latent heat and mineral precipitation suggests the Rayleigh number (Ra, a measure of convective vigor) for this system is ~103 well above the critical Ra of 4π2. Second, to account for the effect of multiphase flow and latent heat, we use two-dimensional numerical models in the finite difference code HYDROTHERM. We find that the geometry of flow is consistent with field observations and confirm that geometry is sensitive to permeability and topography. These tests suggest a few things about low-pressure hydrothermal systems. 1) The geometry of at least some convection appears to be broadly captured by linear stability theory that ignores reactive transport, heterogeneity of host rock, and the effects of latent heat. 2) Topographic flow sets the wavelength of convection meaning that these columns formed somewhere without topography—probably a lake. Finally, these observations imply a wet paleoclimate in the Eastern Sierra namely that, in the aftermath of the Long Valley eruption, either rain or snow was able to pool in the caldera before the tuff cooled on the order of a hundred years after the eruption.

  6. In situ measurements of tropical cloud properties in the West African Monsoon: upper tropospheric ice clouds, Mesoscale Convective System outflow, and subvisual cirrus

    Directory of Open Access Journals (Sweden)

    W. Frey

    2011-06-01

    Full Text Available In situ measurements of ice crystal size distributions in tropical upper troposphere/lower stratosphere (UT/LS clouds were performed during the SCOUT-AMMA campaign over West Africa in August 2006. The cloud properties were measured with a Forward Scattering Spectrometer Probe (FSSP-100 and a Cloud Imaging Probe (CIP operated aboard the Russian high altitude research aircraft M-55 Geophysica with the mission base in Ouagadougou, Burkina Faso. A total of 117 ice particle size distributions were obtained from the measurements in the vicinity of Mesoscale Convective Systems (MCS. Two to four modal lognormal size distributions were fitted to the average size distributions for different potential temperature bins. The measurements showed proportionately more large ice particles compared to former measurements above maritime regions. With the help of trace gas measurements of NO, NOy, CO2, CO, and O3 and satellite images, clouds in young and aged MCS outflow were identified. These events were observed at altitudes of 11.0 km to 14.2 km corresponding to potential temperature levels of 346 K to 356 K. In a young outflow from a developing MCS ice crystal number concentrations of up to (8.3 ± 1.6 cm−3 and rimed ice particles with maximum dimensions exceeding 1.5 mm were found. A maximum ice water content of 0.05 g m−3 was observed and an effective radius of about 90 μm. In contrast the aged outflow events were more diluted and showed a maximum number concentration of 0.03 cm−3, an ice water content of 2.3 × 10−4 g m−3, an effective radius of about 18 μm, while the largest particles had a maximum dimension of 61 μm.

    Close to the tropopause subvisual cirrus were encountered four times at altitudes of 15 km to 16.4 km. The mean ice particle number concentration of these encounters was 0.01 cm−3 with maximum particle sizes of 130

  7. Final design of a free-piston hydraulic advanced Stirling conversion system

    Science.gov (United States)

    Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    1991-01-01

    Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

  8. Rapid analysis of hay attributes using NIRS. Final report, Task II alfalfa supply system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-24

    This final report provides technical information on the development of a near infrared reflectance spectroscopy (NIRS) system for the analysis of alfalfa hay. The purpose of the system is to provide consistent quality for processing alfalfa stems for fuel and alfalfa leaf meal products for livestock feed. Project tasks were to: (1) develop an NIRS driven analytical system for analysis of alfalfa hay and processed alfalfa products; (2) assist in hiring a qualified NIRS technician and recommend changes in testing equipment necessary to provide accurate analysis; (3) calibrate the NIRS instrument for accurate analyses; and (4) develop prototype equipment and sampling procedures as a first step towards development of a totally automated sampling system that would rapidly sample and record incoming feedstock and outbound product. An accurate hay testing program was developed, along with calibration equations for analyzing alfalfa hay and sun-cured alfalfa pellets. A preliminary leaf steam calibration protocol was also developed. 7 refs., 11 figs., 10 tabs.

  9. Final design of a free-piston hydraulic advanced Stirling conversion system

    Science.gov (United States)

    Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

  10. Basic concept of common reactor physics code systems. Final report of working party on common reactor physics code systems (CCS)

    International Nuclear Information System (INIS)

    2004-03-01

    A working party was organized for two years (2001-2002) on common reactor physics code systems under the Research Committee on Reactor Physics of JAERI. This final report is compilation of activity of the working party on common reactor physics code systems during two years. Objectives of the working party is to clarify basic concept of common reactor physics code systems to improve convenience of reactor physics code systems for reactor physics researchers in Japan on their various field of research and development activities. We have held four meetings during 2 years, investigated status of reactor physics code systems and innovative software technologies, and discussed basic concept of common reactor physics code systems. (author)

  11. Final analysis and design of a thermal protection system for 8-foot HTST combustor

    Science.gov (United States)

    Moskowitz, S.

    1973-01-01

    The cylindrical shell combustor with T-bar supports in the 8-foot HTST at the NASA-Langley Research Center encountered vibratory fatigue cracking over a period of 50-250 tunnel tests within a limited range of the required operating envelope. A preliminary design study provided several suitable thermal protection system designs for the combustor, one of which was a two-pass regenerative type air-cooled omega-shaped segment liner. A final design layout of the omega segment liner was prepared and analyzed for steady-state and transient conditions. The design of a support system for the fuel spray bar assembly was also included. Detail drawings suitable for fabrication purposes were also prepared. Liner design problems defined during the preliminary study included (1) the ingress of gas into the attachment bulb section of the omega segment, (2) the large thermal gradient along the leg of the omega bulb attachment section and, (3) the local peak metal temperature at the radius between the liner ID and the leg of the bulb attachment. These were resolved during the final design task. Analyses of the final design of the omega segment liner indicated that all design goals were met and the design provided the capability of operating over the required test envelope with a life expectancy substantially above the goal of 1500 cycles.

  12. Advanced Traveler Information Systems (ATIS) 2.0 Precursor System: Final Report

    Science.gov (United States)

    2018-03-01

    Advanced Traveler Information Systems (ATIS) have experienced significant growth since their initial inception in the 1990s. Technologies have continued to evolve at a rapid pace, enabling the integration of advanced solutions for traveler informatio...

  13. Analytical approach to chromatic correction in the final focus system of circular colliders

    Directory of Open Access Journals (Sweden)

    Yunhai Cai

    2016-11-01

    Full Text Available A conventional final focus system in particle accelerators is systematically analyzed. We find simple relations between the parameters of two focus modules in the final telescope. Using the relations, we derive the chromatic Courant-Snyder parameters for the telescope. The parameters are scaled approximately according to (L^{*}/β_{y}^{*}δ, where L^{*} is the distance from the interaction point to the first quadrupole, β_{y}^{*} the vertical beta function at the interaction point, and δ the relative momentum deviation. Most importantly, we show how to compensate its chromaticity order by order in δ by a traditional correction module flanked by an asymmetric pair of harmonic multipoles. The method enables a circular Higgs collider with 2% momentum aperture and illuminates a path forward to 4% in the future.

  14. Total System Performance Assessment Sensitivity Analyses for Final Nuclear Regulatory Commission Regulations

    International Nuclear Information System (INIS)

    Bechtel SAIC Company

    2001-01-01

    This Letter Report presents the results of supplemental evaluations and analyses designed to assess long-term performance of the potential repository at Yucca Mountain. The evaluations were developed in the context of the Nuclear Regulatory Commission (NRC) final public regulation, or rule, 10 CFR Part 63 (66 FR 55732 [DIRS 156671]), which was issued on November 2, 2001. This Letter Report addresses the issues identified in the Department of Energy (DOE) technical direction letter dated October 2, 2001 (Adams 2001 [DIRS 156708]). The main objective of this Letter Report is to evaluate performance of the potential Yucca Mountain repository using assumptions consistent with performance-assessment-related provisions of 10 CFR Part 63. The incorporation of the final Environmental Protection Agency (EPA) standard, 40 CFR Part 197 (66 FR 32074 [DIRS 155216]), and the analysis of the effect of the 40 CFR Part 197 EPA final rule on long-term repository performance are presented in the Total System Performance Assessment--Analyses for Disposal of Commercial and DOE Waste Inventories at Yucca Mountain--Input to Final Environmental Impact Statement and Site Suitability Evaluation (BSC 2001 [DIRS 156460]), referred to hereafter as the FEIS/SSE Letter Report. The Total System Performance Assessment (TSPA) analyses conducted and documented prior to promulgation of the NRC final rule 10 CFR Part 63 (66 FR 55732 [DIRS 156671]), were based on the NRC proposed rule (64 FR 8640 [DIRS 101680]). Slight differences exist between the NRC's proposed and final rules which were not within the scope of the FEIS/SSE Letter Report (BSC 2001 [DIRS 156460]), the Preliminary Site Suitability Evaluation (PSSE) (DOE 2001 [DIRS 155743]), and supporting documents for these reports. These differences include (1) the possible treatment of ''unlikely'' features, events and processes (FEPs) in evaluation of both the groundwater protection standard and the human-intrusion scenario of the individual

  15. Inertial confinement fusion driver enhancements: Final focusing systems and compact heavy-ion driver designs

    International Nuclear Information System (INIS)

    Bieri, R.L.

    1991-01-01

    Required elements of an inertial confinement fusion power plant are modeled and discussed. A detailed analysis of two critical elements of candidate drivers is done, and new component designs are proposed to increase the credibility and feasibility of each driver system. An analysis of neutron damage to the final elements of a laser focusing system is presented, and multilayer -- dielectric mirrors are shown to have damage lifetimes which axe too short to be useful in a commercial power plant. A new final-focusing system using grazing incidence metal mirrors to protect sensitive laser optics is designed and shown to be effective in extending the lifetime of the final focusing system. The reflectivities and damage limits of grazing incidence metal mirrors are examined in detail, and the required mirror sizes are shown to be compatible with the beam sizes and illumination geometries currently envisioned for laser drivers. A detailed design and analysis is also done for compact arrays of superconducting magnetic quadrupoles, which are needed in a multi-beam heavy-ion driver. The new array model is developed in more detail than some previous conceptual designs and models arrays which are more compact than arrays scaled from existing single -- quadrupole designs. The improved integrated model for compact arrays is used to compare the effects of various quadrupole array design choices on the size and cost of a heavy-ion driver. Array design choices which significantly affect the cost of a heavy-ion driver include the choice of superconducting material and the thickness of the collar used to support the winding stresses. The effect of these array design choices on driver size and cost is examined and the array model is used to estimate driver cost savings and performance improvements attainable with aggressive quadrupole array designs with high-performance superconductors

  16. Ceramics and healthy heating and cooling systems: thermal ceramic panels in buildings. Conditions of comfort and energy demand versus convective systems

    Directory of Open Access Journals (Sweden)

    V. Echarri Iribarren

    2016-12-01

    Full Text Available Porcelain stoneware is a widely used building material. In recent years, its range of uses has expanded to encompass a new spectrum of innovative and inventive applications in architecture. In this research, we analysed the patented Thermal Ceramic Panel. This consists of a thin porcelain stoneware panel that incorporates a capillary system of polypropylene tubes measuring 3.5 mm in diameter embedded in a conductive ceramic interface. The system works with hot or cold water, producing healthy heating and cooling by means of radiant surfaces. Following an initial prototype test in which panels were placed on the walls of an office, we conducted simulations at the University of Alicante Museum using wall, ceiling and baffle panels, having previously monitored the state of the building. Thermal behaviour parameters were analysed and compared with those of other standard finishing materials, obtaining results for thermal comfort and energy savings in comparison with all-air systems.

  17. Columbia River System Operation Review final environmental impact statement. Appendix I: Power

    International Nuclear Information System (INIS)

    1995-11-01

    The System Operation Review (SOR) is a study and environmental compliance process being used by the three Federal agencies to analyze future operations of the system and river use issues. The goal of the SOR is to achieve a coordinated system operation strategy for the river that better meets the needs of all river users. This technical appendix addresses only the effects of alternative system operating strategies for managing the Columbia River system. This appendix discusses the work performed by the SOR Power Work Group. The Power Work Group (PWG) had several major responsibilities: first, to determine the effects of each of the various system operating strategies (SOS) on the Northwest regional power system; second, given these effects, to determine what, if any, actions are required to meet forecasted regional energy consumption; and finally, to estimate the cost for serving the forecasted regional energy consumption. The Northwest regional power system consists of Federal and non-Federal hydroelectric power projects (hydropower or hydro projects) on the main stem of the Columbia and Snake Rivers, numerous smaller hydro projects on other river reaches, and a number of thermal plants (coal, nuclear and combustion turbines)

  18. Merit-Based Incentive Payment System: Meaningful Changes in the Final Rule Brings Cautious Optimism.

    Science.gov (United States)

    Manchikanti, Laxmaiah; Helm Ii, Standiford; Calodney, Aaron K; Hirsch, Joshua A

    2017-01-01

    The Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) eliminated the flawed Sustainable Growth Rate (SGR) act formula - a longstanding crucial issue of concern for health care providers and Medicare beneficiaries. MACRA also included a quality improvement program entitled, "The Merit-Based Incentive Payment System, or MIPS." The proposed rule of MIPS sought to streamline existing federal quality efforts and therefore linked 4 distinct programs into one. Three existing programs, meaningful use (MU), Physician Quality Reporting System (PQRS), value-based payment (VBP) system were merged with the addition of Clinical Improvement Activity category. The proposed rule also changed the name of MU to Advancing Care Information, or ACI. ACI contributes to 25% of composite score of the four programs, PQRS contributes 50% of the composite score, while VBP system, which deals with resource use or cost, contributes to 10% of the composite score. The newest category, Improvement Activities or IA, contributes 15% to the composite score. The proposed rule also created what it called a design incentive that drives movement to delivery system reform principles with the inclusion of Advanced Alternative Payment Models (APMs).Following the release of the proposed rule, the medical community, as well as Congress, provided substantial input to Centers for Medicare and Medicaid Services (CMS),expressing their concern. American Society of Interventional Pain Physicians (ASIPP) focused on 3 important aspects: delay the implementation, provide a 3-month performance period, and provide ability to submit meaningful quality measures in a timely and economic manner. The final rule accepted many of the comments from various organizations, including several of those specifically emphasized by ASIPP, with acceptance of 3-month reporting period, as well as the ability to submit non-MIPS measures to improve real quality and make the system meaningful. CMS also provided a mechanism for

  19. Reliability centered maintenance pilot system implementation 241-AP-tank farm primary ventilation system final report

    International Nuclear Information System (INIS)

    MOORE TL

    2001-01-01

    When the Hanford Site Tank Farms' mission was safe storage of radioactive waste in underground storage tanks, maintenance activities focused on time-based preventive maintenance. Tank Farms' new mission to deliver waste to a vitrification plant where the waste will be processed into a form suitable for permanent storage requires a more efficient and proactive approach to maintenance. Systems must be maintained to ensure that they are operational and available to support waste feed delivery on schedule with a minimum of unplanned outages. This report describes the Reliability Centered Maintenance (RCM) pilot system that was implemented in the 241-AP Tank Farm Primary Ventilation System under PI-ORP-009 of the contract between the U.S. Department of Energy, Office of River Protection and CH2M HILL Hanford Group Inc. (CHG). The RCM analytical techniques focus on monitoring the condition of operating systems to predict equipment failures so that maintenance activities can be completed in time to prevent or mitigate unplanned equipment outages. This approach allows maintenance activities to be managed with minimal impact on plant operations. The pilot demonstration provided an opportunity for CHG staff-training in RCM principles and tailoring of the RCM approach to the Hanford Tank Farms' unique needs. This report details the implementation of RCM on a pilot system in Tank Farms

  20. International benchmark on the natural convection test in Phenix reactor

    International Nuclear Information System (INIS)

    Tenchine, D.; Pialla, D.; Fanning, T.H.; Thomas, J.W.; Chellapandi, P.; Shvetsov, Y.; Maas, L.; Jeong, H.-Y.; Mikityuk, K.; Chenu, A.; Mochizuki, H.; Monti, S.

    2013-01-01

    Highlights: ► Phenix main characteristics, instrumentation and natural convection test are described. ► “Blind” calculations and post-test calculations from all the participants to the benchmark are compared to reactor data. ► Lessons learned from the natural convection test and the associated calculations are discussed. -- Abstract: The French Phenix sodium cooled fast reactor (SFR) started operation in 1973 and was stopped in 2009. Before the reactor was definitively shutdown, several final tests were planned and performed, including a natural convection test in the primary circuit. During this natural convection test, the heat rejection provided by the steam generators was disabled, followed several minutes later by reactor scram and coast-down of the primary pumps. The International Atomic Energy Agency (IAEA) launched a Coordinated Research Project (CRP) named “control rod withdrawal and sodium natural circulation tests performed during the Phenix end-of-life experiments”. The overall purpose of the CRP was to improve the Member States’ analytical capabilities in the field of SFR safety. An international benchmark on the natural convection test was organized with “blind” calculations in a first step, then “post-test” calculations and sensitivity studies compared with reactor measurements. Eight organizations from seven Member States took part in the benchmark: ANL (USA), CEA (France), IGCAR (India), IPPE (Russian Federation), IRSN (France), KAERI (Korea), PSI (Switzerland) and University of Fukui (Japan). Each organization performed computations and contributed to the analysis and global recommendations. This paper summarizes the findings of the CRP benchmark exercise associated with the Phenix natural convection test, including blind calculations, post-test calculations and comparisons with measured data. General comments and recommendations are pointed out to improve future simulations of natural convection in SFRs