Science.gov (United States)

We report the of the existence of RV Tauri stars in the Large Magellanic Cloud (LMC). This class of variable star has hitherto been unidentified in the Magellanic Clouds. In light and color curve behavior the RV Tauri stars appear to be an extension of the Type II Cepheids to longer periods. A single period-luminosity-color relationship is seen to describe both the Type II Cepheids and the RV Tauri stars in the LMC.

CERN Document Server

We outline to the community the value of a Magellanic Clouds Survey that consists of three components: I) a complete-area, high resolution, multi-band UV-near-IR broadband survey; II) a narrowband survey in 7 key nebular filters to cover a statistically significant sample of representative HII regions and a large-area, contiguous survey of the diffuse, warm ISM; and III) a comprehensive FUV spectroscopic survey of 1300 early-type stars. The science areas enabled by such a dataset are as follows: A) assessment of massive star feedback in both HII regions and the diffuse, warm ISM; B) completion of a comprehensive study of the 30 Doradus giant extragalactic HII region (GEHR); C) development and quantitative parameterization of stellar clustering properties; D) extensive FUV studies of early-type stellar atmospheres and their energy distributions; and E) similarly extensive FUV absorption-line studies of molecular cloud ...

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The paper presents cloud structure models for Jupiter's Great Red Spot, Equatorial and North Tropical Zones, North and South Temperate Zones, and North and South Polar Regions. The models are based on images of Jupiter in three methane bands and nearby continuum radiative transfer calculations include multiple scattering and absorption from three aerosol layers. The model results include the transition in the upper-cloud altitude to 3 km lower altitude from the tropical zones to temperate zones and polar regions, a N/S asymmetry in cloud thickness in the tropical and temperature zones, and the presence of aerosols up to about 0.3 bar in the Great Red Spot and Equatorial Zone. It is concluded that polarization data are sensitive to aerosols in and above the upper cloud layer but insensitive to deeper cloud structure.

British Library Electronic Table of Contents (United Kingdom)

Abstract The Planck-ATCA Coeval Observations (PACO) project collected data between 4.5 and 40 GHz for 482 sources selected within the Australia Telescope 20 GHz (AT20G) catalogue and observed with the Australia Telescope Compact Array. Observations were done almost simultaneously with the-Planck-satellite, in the period between 2009 July and 2010 August. In this paper, we present and discuss the data for the complete sample of 159 sources with-SAT20G > 200-mJy in the South Ecliptic Pole region. The Planck Early Release Compact Source Catalogue (ERCSC) contains 57 of our sources. A comparison between the PACO catalogue and the ERCSC confirms that the reliability of the latter is better than 95-per cent. The missing ERCSC sources are typically associated with the Large Magellanic Cloud, the ...

CERN Document Server

Because Spitzer is an Earth-trailing orbit, losing about 0.1 AU/yr, it is excellently located to perform microlens parallax observations toward the Magellanic Clouds (LMC/SMC) and the Galactic bulge. These yield the so-called ``projected velocity'' of the lens, which can distinguish statistically among different populations. A few such measurements toward the LMC/SMC would reveal the nature of the lenses being detected in this direction (dark halo objects, or ordinary LMC/SMC stars). Cool Spitzer has already made one such measurement of a (rare) bright red-clump source, but warm (presumably less oversubscribed) Spitzer could devote the extra time required to obtain microlens parallaxes for the more common, but fainter, turnoff sources. Warm Spitzer could observe bulge microlenses for 38 days per year, which would permit up to 24 microlens parallaxes per year. This would yield interesting information on the disk mass function, particularly old ...

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I present a promising route to harmonize distance measurements based on clump giants and RR Lyrae stars. This is achieved by comparing the brightness of these distance indicators in three environments: the solar neighborhood, Galactic bulge and Large Magellanic Cloud (LMC). As a result of harmonizing the distance scales in the solar neighborhood and Baade's Window, I derive the new absolute magnitude of RR Lyrae stars, M{sub v}(RR) at [Fe/H] = -1.6 (0.59 {+-} 0.05, 0.70 {+-} 0.05). Being somewhat brighter than the statistical parallax solution, but fainter than typical results of the main sequence fitting to Hipparcos data, these values of M{sub V}(RR) favor intermediate or old ages of globular clusters. Harmonizing the distance scales in the LMC and Baade's Window, I show that the most likely distance modulus to the LMC, {mu}{sub LMC} is in the range 18.24 - 18.44. The Hubble constant of about 70 km/s/Mpc reported by the HST ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Young protostars embedded in circumstellar discs accrete from an angular momentum rich mass reservoir. Without some braking mechanism, all stars should be spinning at or near breakup velocity. In this paper, we perform simulations of the self-gravitational collapse of an isothermal cloud using the orion adaptive-mesh refinement code and investigate the role that gravitational torques might play in the spin-down of the dense central object. While magnetic effects likely dominate for low-mass stars, high-mass and Population III stars might be less well magnetized. We find that gravitational torques alone prevent the central object from spinning up to more than half of its breakup velocity, because higher rotation rates lead to bar-like deformations that enable efficient angular mome...

International Nuclear Information System (INIS)

The collapse and fragmentation of initially prolate and oblate, magnetic molecular clouds is calculated in three dimensions with a gravitational, radiative hydrodynamics code. The code includes magnetic field effects in an approximate manner: magnetic pressure, tension, braking, and ambipolar diffusion are all modeled. The parameters varied for both the initially prolate and oblate clouds are the initial degree of central concentration of the radial density profile, the initial angular velocity, and the efficiency of magnetic braking (represented by a factor f _m_b = 10"-"4 or 10"-"3). The oblate cores all collapse to form rings that might be susceptible to fragmentation into multiple systems. The outcome of the collapse of the prolate cores depends strongly on the initial density profile. Prolate cores with central densities 20 times higher than their boundary densities collapse and fragment into binary or quadruple systems, whereas cores with ...

Science.gov (United States)

Not Available

Science.gov (United States)

Main purpose of mapping observations of the cloud is to make clear the mechanism of star formation and star evolution. Scientific objectives are summarized ...

Wastenet

... - Climate Action Programme cloud computing, climaet change, carbon emissions, verdantix, cloud, it, computer cloud computing, climaet change, carbon emissions,...verdantix, cloud, it, computer GreenMedia.com AidForumOnline.org ClimateActionProgramme.org Search Climate Action... In partnership with the United Nations ...

Science.gov (United States)

National Aeronautics and Space Administration. Issue 2. June 2010 this issue. Nebula: Cloud Computing p.1. Better Business with EA p.2 ...

Science.gov (United States)

NASA Nebula in Action: Cloud Computing Case Examples. James Williams, NASA Ames Research Center, james.f.williams@nasa.gov. Abstract In 2009 ...

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Necessary conditions are derived for compact aggregates of solid matter to develop from loose local clumps of dust grains in a contracting protostellar cloud.

Czech Academy of Sciences Repository

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International Nuclear Information System (INIS)

A consistent mathematical derivation is given for the Sommerfeld fine structure electromagnetic coupling 1/?-bar 0=?0-bar 1/137.036. Following 't Hooft's holographic principle two complimentary forms of the derivation are given both leading to the E(?) theoretical value, namely ?-bar 0=(20)(1/?)4=137.082039311. The experimental value is subsequently found by projection as ?-bar 0(exp)=137/[cos(?/?-bar 0)]-bar 137.036.

Science.gov (United States)

The effect of aerosol on clouds poses one of the largest uncertainties in estimating the anthropogenic contribution to climate change. Small human-induced perturbations to cloud characteristics via aerosol pathways can create a change in the top-of-atmosphere radiative forcing of hundreds of Wm-2. Here we focus on links between aerosol and deep convective clouds of the Atlantic and Pacific Intertropical Convergence Zones, noting that the aerosol environment in each region is entirely different. The tops of these vertically developed clouds consisting of mostly ice can reach high levels of the atmosphere, overshooting the lower stratosphere and reaching altitudes greater than 16 km. We show a link between aerosol, clouds and the free atmosphere wind profile that can change the magnitude and sign of the overall climate radiative forcing. We find that increased aerosol loading is ...

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We present photoelectric BVRI photometry for 16 T Tau and related stars in the Rho Oph dark cloud, as well as vidicon spectroscopic observations for nine stars. The color excesses of these stars favor circumstellar dust shells as the source of the observed infrared excesses.

Science.gov (United States)

... say for sure if the signal is coming from hail, lots of graupel, or some other hydrometeor . ... Precipitation forms when cloud droplets or ice particles in clouds grow and .... A landslide is the movement of rock, debris, or earth down a slope. ...

Energy Technology Data Exchange (ETDEWEB)

Two additional hyperfine components of the interstellar radical C3H were detected. In addition, methanol was discovered in interstellar clouds. The abundance of HCCN and various chemical isomers in molecular clouds was investigated.

Science.gov (United States)

... The rounds were initiated by an exploding bridgewire detonator (EBW) and the ionisation probes were progressively cloud by the detonation front. ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Satellite measurements and numerical forecast model reanalysis data are used to compute an updated estimate of the cloud radiative effect on the global multi-annual mean radiative energy budget of the atmosphere and surface. The cloud radiative cooling effect through reflection of short wave radiation dominates over the long wave heating effect, resulting in a net cooling of the climate system of - 21 Wm-2. The short wave radiative effect of cloud is primarily manifest as a reduction in the solar radiation absorbed at the surface of - 53 Wm-2. Clouds impact long wave radiation by heating the moist tropical atmosphere (up to around 40 Wm-2 for global annual means) while enhancing the radiative cooling of the atmosphere over other regions, in particular higher latitudes and sub-trop...

International Nuclear Information System (INIS)

The phase separation of (water + salt + polyethylene glycol 15000) systems was studied by cloud-point measurements using the particle counting method. The effect of three kinds of sulphate salt (Na2SO4, K2SO4, (NH4)2SO4) concentration, polyethylene glycol 15000 concentration, mass ratio of polymer to salt on the cloud-point temperature of these systems have been investigated. The results obtained indicate that the cloud-point temperatures decrease linearly with increase in polyethylene glycol concentrations for different salts. Also, the cloud points decrease with an increase in mass ratio of salt to polymer.

International Nuclear Information System (INIS)

The purpose of this investigation is to show that resource to anisotropic compression along a magnetic field is not a necessary condition for star formation within large collapsing interstellar gas clouds. Although such a scenario would certainly eliminate the magnetic field and angular momentum problems associated with isotropically collapsing clouds, it is believed there is sufficient observational theoretical evidence to warrant the present study of magnetically braked, isotropically collapsing gas clouds. It is not attempted to disprove the hypothesis of anisotropic compression, but to offer instead, a reasonable alternative. Angular momentum transfer from magnetically braked, cool interstellar gas clouds of 10"2, 10"3 and 10"4 times the mass of the sun is examined. Magnetic torques acting on a contracting, rotating cloud, permeated by a frozen-in magnetic field coupling the ...

CERN Document Server

Prompted by work on the buckling instability in barred spiral galaxies, much effort has been devoted lately to the study of boxy/peanut-shaped (B/PS) bulges. Here, we present new bar diagnostics for edge-on spiral galaxies based on periodic orbits calculations and hydrodynamical simulations. Both approaches provide reliable ways to identify bars and their orientations in edge-on systems. We also present the results of an observational search for bars in a large sample of edge-on spirals with and without B/PS bulges. We show that most B/PS bulges are due to the presence of a thick bar viewed edge-on while only a few may be due to accretion. This strongly supports the bar-buckling mechanism for the formation of B/PS bulges.

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Characterization and performance testing of a prototype DWPF Melter No.2 Dome Heater Bus Bar are described. The prototype bus bar was designed to address the design features of the existing system which may have contributed to water leaks on Melter No.1. Performance testing of the prototype revealed significant improvement over the existing design in reduction of both bus bar and heater connection maximum temperature, while characterization revealed a few minor design and manufacturing flaws in the bar. The prototype is recommended as an improvement over the existing design. Recommendations are also made in the area of quality control to ensure that critical design requirements are met.

CERN Document Server

Towards the end of the 19th century, Kelvin pronounced as the "clouds of physics" 1) the failure of the Michelson-Morely experiment to detect an ether wind, 2) the violation of the classical mechanical equipartition theorem in statistical thermodynamics. And he believed that the removal of these clouds would bring physics to an end. But as we know, the removal of these clouds led to the two great breakthoughts of modern physics: 1) The theory of relativity, and 2) to quantum mechanics. Towards the end of the 20th century more clouds of physics became apparent. They are 1) the riddle of quantum gravity, 2) the superluminal quantum correlations, 3) the small cosmological constant. Furthermore, there is the riddle of dark energy making up 70% of the physical universe, the non-baryonic cold dark matter making up 26% and the very small initial entropy of the universe. An attempt is made to explain the ...

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This document is a progress report to the USDOE Atmospheric Radiation and Measurement Program (ARM). The overall project goal is to relate subgrid-cumulus-cloud formation, coverage, and population characteristics to statistical properties of surface-layer air, which in turn are modulated by heterogeneous land-usage within GCM-grid-box-size regions. The motivation is to improve the understanding and prediction of climate change by more accurately describing radiative and cloud processes.

Science.gov (United States)

Evolution in Space Radio Telescopes Reveal Youngest Stellar Corpse Gas Clouds in Whirlpool Galaxy Yield Important Clues Supporting Theory on Spiral Arms Starbust-driven Winds...

UK PubMed Central (United Kingdom)

This article addresses the need for new data on indirect effects of natural and anthropogenic aerosol particles on atmospheric ice clouds. Simultaneous measurements of the concentration and composition...Full Text Available

International Nuclear Information System (INIS)

Depletion studies are used to infer the presence of mantles and to constrain grain evolutionary models in the diffuse interstellar medium. The presence of these mantles appears to be important in the evolution of the grains inside diffuse as well as dense clouds. In dense clouds where the element-to-element abundances sometimes differ from those found in diffuse clouds, empirical relationships are starting to emerge between gas abundances and various types of peculiar selective extinction. These peculiar extinction curves may be the results of nonvolatile mantle formation on grain cores or may reflect chemical differences due to variations in the intrinsic metalicity from one cloud to another. A simple model of the time evolution of a parcel of gas and dust as observed by the depletion of two elements is presented. Different studies of grain evolution and selective extinction are discussed and compared.

British Library Electronic Table of Contents (United Kingdom)

A suite of numerical experiments is conducted to extend our previous studies to explore the effects of linear, ambient wind shear on simulated mammatus-like clouds. Increasing values of unidirectional shear result in banded cloud bases, and for the strongest shears roll-type quasi-two-dimensional convection results rather than three-dimensional lobe morphology. Two observed soundings were used, and the sounding with a drier, shallower sub-cloud layer appeared to be most strongly affected by the presence of the ambient shear. The drier sounding also had less snow in the mammatus lobes owing to sublimation. Copyright Copyright 2009 Royal Meteorological Society

CERN Document Server

We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical evolution. We then allow the same gas immediately to undergo further such formation and dispersion cycles. The chemistry of the dense gas in subsequent cycles is similar to that of the first, and a limit cycle is reached quickly (2 - 3 cycles). Enhancement of hydrocarbon abundances during a specific period of evolution is the strongest indicator of previous dynamical history. The molecular content of the diffuse background gas in the molecular cloud is expected to be strongly enhanced by the core formation and dispersion process. Such enhancement may remain for as long as 0.5 Myr. The frequency of repetitive core formation should strongly determine the level of background molecular enhancement. We also convolve the ...

British Library Electronic Table of Contents (United Kingdom)

This experimental study investigates the effectiveness of crossed inclined bars (X-bars) as joint shear reinforcement in exterior reinforced concrete beam-column connections under cyclic deformations. Test results of 20 joint subassemblages with various reinforcement ratios and arrangements including X-bars in the joint area are presented. The X-type, non-conventional reinforcement is examined as the only joint reinforcement and in combination with common stirrups or vertical bars. The experimental results reported herein include full loading cycle curves, energy dissipation values and a categorization of the observed damage modes. Based on the comparisons between the overall hysteretic responses of the tested specimens, it is deduced that joints with X-bars exhibited enhanced cyclic perfo...

International Nuclear Information System (INIS)

A morphological survey of barred galaxies is made to investigate the frequency of occurrence, nature, and size distributions of bars, lenses, inner and outer rings, and global spiral structure. The 121 brightest available barred galaxies are examined on Sky Survey copy plates, and on deeper and larger-scale plates, with the following main results.1. Lenses and inner rings are components of major importance in barred galaxies, occurring, respectively, in 54% of SBO--SBa, and 76% of SBab--SBc galaxies. Few early-type galaxies have rings; almost no late-type ones have lenses.2. There is an intimate connection between bars and lenses: in 17 of 20 galaxies with both components, the bar exactly fills the lens in one dimension.3. We suggest that lenses originate as bars, through an unknown process which makes some bars evolve ...

International Nuclear Information System (INIS)

Dynamical models are presented that start with interstellar gas in an initial diffuse state and consider their gravitational collapse and the formation of dense cores. Frozen-in tangled magnetic fields are included to mimic forces that might oppose gravitational contraction and whose effectiveness may increase with increasing core densities. Results suggest the possibility that dense cloud cores may be dynamically evolving ephemeral objects, such that their lifespan at a given core density decreases as that density increases. 66 refs.

International Nuclear Information System (INIS)

The energy spectra of energetic confined alpha particles are being measured using the pellet charge exchange method [R. K. Fisher, J. S. Leffler, A. M. Howald, and P. B. Parks, Fusion Technol. 13, 536 (1988)]. The technique uses the dense ablation cloud surrounding an injected impurity pellet to neutralize a fraction of the incident alpha particles, allowing them to escape from the plasma where their energy spectrum can be measured using a neutral particle analyzer. The signal calculations given in the above-mentioned reference disregarded the effects of the alpha particles' helical Larmor orbits, which causes the alphas to make multiple passes through the cloud. Other effects such as electron ionization by plasma and ablation cloud electrons and the effect of the charge state composition of the cloud, were also neglected. This report considers these issues, reformulates the signal level calculation, ...

International Nuclear Information System (INIS)

Kinetic Monte Carlo (KMC) computer simulations are performed to determine the kinetics of SIA cluster 'clouds' in the vicinity of edge dislocations. The simulations include elastic interactions amongst SIA clusters, and between clusters and dislocations. Results of KMC simulations that describe the formation of 'SIA clouds' during neutron irradiation of bcc Fe and the corresponding evolution kinetics are presented, and the size and spatial distribution of SIA clusters in the cloud region are studied for a variety of neutron displacement damage dose levels. We then investigate the collective spatio-temporal dynamics of SIA clusters in the presence of internal elastic fields generated by static and mobile dislocations. The main features of the investigations are: (1) determination of the kinetics and spatial extent of defect clouds near static dislocations; (2) assessment of the influence of localized ...

Energy Technology Data Exchange (ETDEWEB)

By using the continuation theorem of coincidence degree theory and constructing suitable Lyapunov functions, we study the existence and stability of periodic solution for shunting inhibitory cellular neural networks (SICNNs) with delays x-bar {sub ij}(t)=-a{sub ij}(t)x{sub ij}(t)--bar B{sup kl}-bar Nr(i,j)B{sub ij}{sup kl}(t)f{sub ij}(x{sub kl}(t))x{sub ij}(t)--bar C{sup kl}-bar Nr(i,j)C{sub ij}{sup kl}(t)g{sub ij}(x{sub kl}(t-{tau}{sub kl}))x{sub ij}(t)+L{sub ij}(t)

International Nuclear Information System (INIS)

The evolution of intergranular lattice strains in a textured, forged bar (Bar) sample of the #alpha# - #beta# titanium alloy Ti-6Al-4V has been characterised using in situ X-ray diffraction. A two-phase elastic-plastic self-consistent (EPSC) model has been developed to rationalise the results. Of the orientations analysed, it is found that the #left brace#2 0 0#right brace# #beta# orientation is the most compliant and that load partitions to this orientation during plasticity. The results from the bar material have then been used to predict the response of unidirectionally rolled plate (UD) Ti-6Al-4V. It is predicted that the residual lattice strains in the #left brace#101-bar0#right brace# and #left brace#112-bar0#right brace# orientations will be significantly higher in the UD material.

CERN Document Server

Present in over 45% of local spirals, boxy and peanut-shaped bulges are generally interpreted as edge-on bars and may represent a key phase in the evolution of bulges. Aiming to test such claims, the kinematic properties of self-consistent 3D N-body simulations of bar-unstable disks are studied. Using Gauss-Hermite polynomials to describe the stellar kinematics, a number of characteristic bar signatures are identified in edge-on disks: 1) a major-axis light profile with a quasi-exponential central peak and a plateau at moderate radii (Freeman Type II profile); 2) a ``double-hump'' rotation curve; 3) a sometime flat central velocity dispersion peak with a plateau at moderate radii and occasional local central minimum and secondary peak; 4) an h3-V correlation over the projected bar length. All those kinematic features are spatially correlated and can easily be understood from the orbital structure of ...

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There are clearly identified scientific requirements for continuous profiling of atmospheric water vapor at the Department of Energy, Atmospheric Radiation Measurement program, Southern Great Plains CART (Cloud and Radiation Testbed) site in northern Oklahoma. Research conducted at several laboratories has demonstrated the suitability of Raman lidar for providing measurements that are an excellent match to those requirements. We have developed and installed a ruggedized Raman lidar system that resides permanently at the CART site, and that is computer automated to eliminate the requirements for operator interaction. In addition to the design goal of profiling water vapor through most of the troposphere during nighttime and through the boundary layer during daytime, the lidar provides quantitative characterizations of aerosols and clouds, including depolarization measurements for particle phase studies.

International Nuclear Information System (INIS)

We have used polarised neutrons to measure the integrated magnetic cross-section of a dilute alloy of Ce in Y a Kondo system, T_K#approx#40 K. Previous polarised neutron measurements of the field-induced magnetic form factor found no anomalies that could be attributed to the formation of a spin compensation cloud around the Ce ion. The present measurements, focused on the diffuse low-Q range, represent information over a very wide length scale in real space. Again, they show no changes in the Q-dependence of the form-factor at low temperatures that could be attributed to the formation of a spin compensation cloud. An alternative interpretation of the phenomenon based on the dynamical magnetic susceptibility of Y-Ce is proposed.

CERN Document Server

The possible physical linkage between galactic cosmic rays intensity and the Earth's cloud cover is discussed using the analysis of the first indirect aerosol effect (Twomey effect) and its experimental representation as the dependence of average cloud droplet effective radius on aerosol index characterizing the aerosol concentration in the atmospheric air column of unit section. It is shown that the basic kinetic equation of the Earth's climate energy-balance model is described by the bifurcation equation (with respect to the temperature of the Earth's surface) in the form of fold catastrophe with two governing parameters defining the variations of insolation and Earth's magnetic field (or galactic cosmic rays intensity in the atmosphere), respectively. The principle of hierarchical climatic models construction, which consists in the structural invariance of balance equations of these models evolving on the different time scales, is described. ...

Science.gov (United States)

The calculations of Gay et al. of the terminal velocities of charged hydrormeteors in the presence of electric fields have formed the basis of computations of the charging current density J flowing through a thunder-cloud as a result of the operation of a precipitative mechanism of cloud electrification. Values of J were calculated for a range of values of field strength E, precipitation rate pO, precipitation content L, cloud water content C, charge distribution, total separated charge, and the fraction of the small particles that have undergone a charging event.It is found that the estimated field required for the initiation of a lightning stroke (3.5 kV cm1 can be achieved only over a narrow range of conditions. The ease with which precipitative mechanisms can produce breakdown fields is considerably increased, however, if account is taken of spatial inhomogenities in the field.

British Library Electronic Table of Contents (United Kingdom)

Genetic analysis of resistance of plant introduction (PI) 438489B to soybean cyst nematode (SCN) have shown that this PI is highly resistant to many SCN HG types. However, validation of the previously detected quantitative trait loci (QTL) has not been done. In this study, 250 F2:3 progeny of a Magellan (susceptible)??PI 438489B (resistant) cross were used for primary genetic mapping to detect putative QTL for resistance to five SCN HG types. QTL confirmation study was subsequently conducted using F6:7 recombinant inbred lines (RILs) derived from the same cross. Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers were employed for molecular genotyping. Interval mapping (IM), permutation tests, cofactor selection, and composite interval mapping (CIM) were performe...

Science.gov (United States)

There are a number of propagation issues that need further investigation for efficient system planning for EHF communication systems. Especially needed are better cloud and rain characterizations. A method for estimating one of the rain induced effects of interest, outage duration, is presented.

Science.gov (United States)

Study of cloud pictures taken from rockets, such as figure 1, indicates that it is .... One might visualize a "Satellite Weather Data Center" where incoming data would ... about 300 miles; satellite packaging, containing the sensors, storage, power, ...

UK PubMed Central (United Kingdom)

Increased clouds and precipitation normally decrease the diurnal temperature range (DTR) and thus have commonly been offered as explanation for the trend of reduced DTR observed for many land areas...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe continued depletion of tropical rainforests and fragmentation of natural habitats has led to significant ecological changes which place most top carnivores under heavy...Full Text Available

Science.gov (United States)

Mar 1, 2011 ... The movement of hydrothermal fluids and/or fumarolic vapors through local rocks prior ... The Solar Energetic Particle Event of December 14, 2006 .... for measurement of non-precipitating cloud hydrometeors and aerosols, ...

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The warm caliber rolling was experimented using the AZ31 magnesium alloy round bar of 20 mm in diameter machined from cast ingot materials. In warm caliber rolling in final size of 10 mm in diameter at 623 K via 8passes, each width-spreading, the change of each microstructure, X-ray analysis of final texture and final mechanical properties were investigated. Microstructure, texture and mechanical properties of warm caliber rolled round bar at 473 K via latter 4passes were compared with those at 623 K consistently. Obtained results are as follows: (1) The width-spreading in caliber rolling of round bar is relatively large, compared with that in flat rolling of the flat bar. The largeness of width-spreading of round bar makes the shape control of cross section difficult, and causes the cracks around the free surface. (2) Finer microstructure and inclined c axis of hexagonal lattice of ...

CERN Document Server

From this vast subject, I will pick out and review three specific topics, namely the formation and evolution of bars, the formation of bulges, and the evolution during multiple major mergers. Bars form naturally in galactic discs. Their evolution is driven by the exchange of angular momentum within the galaxy. This is emitted mainly by near-resonant material in the inner disc (bar), and is absorbed by near-resonant material in the outer disc and in the halo. As a result of this, the bar becomes stronger and rotates slower. Bulges are not a homogeneous class of objects. Based on their formation history, one can distinguish three types. Classical bulges are mainly formed before the actual disc component, from collapses or mergers and the corresponding dissipative processes. Boxy/peanut bulges are parts of bars seen edge-on. Finally, disc-like bulges are formed by the inflow of ...

CERN Document Server

We discuss the evolution of a disc galaxy due to the formation of a bar and, subsequently, a peanut. After the formation stage there is still considerable evolution, albeit slower. In purely stellar cases the pattern speed of the bar decreases with time, while its amplitude grows. However, if a considerable gaseous component is present in the disc, the pattern speed may increase with time, while the bar strength may decrease. In some cases the gas can be brought sufficiently close to the center to create a strong central concentration, which, in turn, may modify the properties of the bar. More violent evolution can take place during interactions, so that some disc substructures can be either formed or destroyed in a time scale which is small compared to a Hubble time. These include spirals, bars, bridges, tails, rings, thick discs and bulges. In some cases interactions may lead to ...

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The micropulse lidar (MPL) is a ground-based optical remote sensing system designed primarily to determine the altitude of clouds overhead. The physical principle is the same as for radar. Pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is infered. Besides real-time detection of clouds, post-processing of the lidar return can also characterize the extent and properties of aerosol or other particle-laden regions.

International Nuclear Information System (INIS)

Continuum events represent an eminent source of background in any e+e- experiment. As these have a higher branching ratio than BB-bar events (at BaBar this ratio is estimated to about 3.5) or ?+?- events, efficient continuum background suppression is essential in many analyses. Using Artificial Neural Networks and the Nearest Neighbor Method we developed several selectors which, based only on the global event shape variables, efficiently tag BB-bar events and ?+?- events against the continuum background. These selectors could then be combined with the channel specific information in various types of analyses. The study was done using a parametric Monte Carlo.

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This report covers the technical effort through February, 1989. This effort was directed towards the technology associated with the development of a large scale, long pulse DF-CO{sub 2} chemical laser. Optics damage studies performed under Task 1 assessed damage thresholds for diamond-turned salt windows. Task 2 is a multi-faceted task involving the use of PHOCL-50 for laser gain measurements, LTI experiments, and detector testing by LANL personnel. To support these latter tests, PHOCL-50 was upgraded with Boeing funding to incorporate a full aperture outcoupler that increased its energy output by over a factor of 3, to a full kilojoule. The PHOCL-50 carbon block calorimeter was also recalibrated and compared with the LANL Scientech meter. Cloud clearing studies under Task 3 initially concentrated on delivering a Boeing built Cloud Simulation Facility to LANL, and currently involves design of a Cold Cloud Simulation ...

CERN Document Server

We report a measurement of the branching fractions for $B^{0} \\rightarrow \\pi^- \\ell^+\

International Nuclear Information System (INIS)

We perform an optimal-observable analysis of the final charged-lepton/b-quark momentum distributions in #gamma##gamma##->#t t-bar #->#lX/bX for various beam polarizations in order to study possible anomalous t t-bar #gamma#, tbW and #gamma##gamma#H couplings, which could be generated by SU(2) x U(1) gauge-invariant dimension-6 effective operators. We find optimal beam polarizations that will minimize the uncertainty in determination of those non-standard couplings. We also compare e e-bar and #gamma##gamma# colliders from the viewpoint of the anomalous-top-quark-coupling determination.

Science.gov (United States)

... Tech. Rep. SE-22.423 pp. 1982. Servo Hanebrink, E.L., A.F.Posey, and K. Sutton. ... ...

British Library Electronic Table of Contents (United Kingdom)

Experiments have been conducted to study the effect of injection pressure on the combustion process and exhaust emissions of a direct injection diesel engine fueled with Orange Skin Powder Diesel Solution (OSPDS). Earlier investigation by the authors revealed that 30% OSPDS was optimum for better performance and emissions. In the present investigation the injection pressure was varied with 30% OSPDS and the combustion, performance and emissions characteristics were compared with those of diesel fuel. The different injection pressures studied were 215bar, 235bar and 255bar. The results showed that the cylinder pressure with 30% OSPDS at 235bar fuel injection pressure, was higher than that of diesel fuel as well as at other injection pressures. Similarly, the ignition delay was longer and wi...

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The e/sup -/..-->..e/sup -/(..nu..nu-bar) process in the field of a circularly polarized plane wave is studied in the framework of the Glashow-Weinberg-Salam model. General expressions for the probability of creation of neutrino pairs are obtained, and the case of a low-intensity wave is studied in detail. The effects of asymmetry of emission of electron and muon neutrinos are estimated, and comparison with previous results is performed.

Energy Technology Data Exchange (ETDEWEB)

We use a nonsingular-potential model for heavy quarkonia proposed by Gupta, Repko, and Suchyta to calculate the transition amplitudes for the magnetic-dipole ({ital M}1) one-photon radiative decays of the {ital c{bar c}} and {ital b{bar b}} bound systems. The wave functions of the bound systems are calculated by a nonperturbative treatment. The results are in better agreement with the experimental data than those predicted using other potential models.

CERN Document Server

After presenting three ways of defining a bulge component in disc galaxies, we introduce the various types of bulges, namely the classical bulges, the boxy/peanut bulges and the disc-like bulges. We then discuss three specific topics linked to bulge formation and evolution, namely the coupled time evolution of the bar, buckling and peanut strengths; the effect of velocity anisotropy on peanut formation; and bulge formation via bar destruction.

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We develop the boundary string field theory approach to tachyon condensation on the D{bar D} system. Particular attention is paid to the gauge fields, which combine with the tachyons in a natural way. We derive the RR couplings of the system and express the result in terms of Quillen's superconnection. The result is related to an index theorem, and is thus shown to be exact.

CERN Document Server

We examine the observable properties of simulated barred galaxies including radial mass profiles, edge-on structure and kinematics, bar lengths and pattern speed evolution for detailed comparison to real systems. We have run several simulations in which bars are created through inherent instabilities in self-consistent simulations of a realistic disc+halo galaxy model with a disc-dominated, flat rotation curve. These simulations were run at high (N=20M particles) and low (N=500K) resolution to test numerical convergence. We determine the pattern speeds in simulations directly from the phase angle of the bar versus time and the Tremaine-Weinberg method. Fundamental dynamics do not change between the high and low resolution, suggesting that convergence has been reached in this case. We find the higher resolution is needed to simulate structural and kinematic properties accurately. The edge-on view of the ...

International Nuclear Information System (INIS)

We give a theoretical design for a locally resonant two-dimensional cylindrical structure involving a pair of C-shaped voids in an elastic medium which we term as double 'C' resonators (DCRs) and imbedded thin stiff bars, that displays the negative refraction effect in the low frequency regime. DCRs are responsible for a low frequency band gap which hybridizes with a tiny gap associated with the presence of the thin bars. Using an asymptotic analysis, typical working frequencies are given in closed form: DCRs behave as Helmholtz resonators modeled by masses connected to clamped walls by springs on either side, while thin bars behave as a periodic bi-atomic chain of masses connected by springs. The discrete models give an accurate description of the location and width of the stop band in the case of the DCR and the first two dispersion bands for the periodic thin bars. We then combine our asymptotic ...

CERN Document Server

The non-thermal supernova remnant RX J1713.7-3946 (G347.3-0.5) has recently been shown to be a site of cosmic ray (CR) electron acceleration to TeV energies (Muraishi et al. 2000). Here we present evidence that this remnant is also accelerating CR nuclei. Such nuclei can interact with ambient interstellar gas to produce high energy gamma-rays via the decay of neutral pions. We associate the unidentified EGRET GeV gamma- ray source 3EG J1714-3857 with a massive (~3*10 5 Mo) and dense (~500 nucleons cm -3) molecular cloud interacting with RX J1713.7-3946. Direct evidence for such interaction is provided by observations of the lowest two rotational transitions of CO in the cloud; as in other clear cases of interaction, the CO(J=2-1)/CO(J=1-0) ratio is significantly enhanced. Since the cloud is of low radio and X-ray brightness, CR electrons cannot be responsible for the bulk of its GeV emission there. A picture thus emerges ...

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Analyses have been made of gases in clouds apparently emanating from Mount Saint Helens. Despite appearances, most of the water in these clouds does not issue from the volcano. Even directly above a large fumarole deltaD and delta/sup 10/O data indicate that only half the water can come from the volcano. Isotopic and chemical evidence also shows the steam in the volcano (-33.0 per mol deltaD) from which a condensate of 0.2 N HCl was obtained is not a major cause of the explosions. The steam in the volcano is derived from a metamorphic brine in the underlying Tertiary meta andesite. The gas that caused the explosive eruptions is carbon dioxide.

Energy Technology Data Exchange (ETDEWEB)

The depletion of stratospheric ozone is caused by chlorine species formed in heterogeneous processes on the surfaces of polar stratospheric cloud (PSC) particles. For studying local PSC formation processes in the Arctic a temperature lidar receiver was developed that makes use of the rotational Raman method, the only lidar technique for measuring atmospheric temperature profiles not perturbed by the presence of aerosols or cloud particles. The receiver was implemented in the mobile GKSS Raman lidar and transferred to Esrange (67.9 N, 21.1 E) near Kiruna in northern Sweden in winter 1997/98. Temperature data measured between January 22 and February 6, 1998, are presented and compared to model data analyzed by the European centre for medium-range weather forecast. Local temperature profiles are studied in three cases of type-Ib PSCs. This type is characterized by a low depolarization ratio. (orig.)

Wastenet

... Project Details Title: Influence of increasing droplet concentrations on properties of stratocumulus clouds and climate Supervisor: Dr Alan Gadian Funded by: Engineering and Physical Sciences Research Council (EPSRC) Start date: October 2006 My project involves use of the UK Met Office Unified Model (UM) to calculate the global effect of modifying stratocumulus droplet concentrations on the earth's radiation balance, as well as use of ... Publications Latham, J; Rasch, P; Chen, CC; Kettles, L; Gadian, A; Gettelman, A; Morrison, H; Bower, K; Choularton, T (2008) Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds, Philos. Trans. Roy. Soc. A, 366(1882), pp3969-3987. doi:10.1098/rsta.2008.0137 Current Students | Internal ...

Energy Technology Data Exchange (ETDEWEB)

The Bureau of Mines has investigated the hazards of military explosives dispersed as dust clouds in a 20-L test chamber. For purposes of personnel safety, the spark ignitability of the explosives in the form of unconfined dust layers was also studied. The 20-L data show that most of the explosives dusts were capable of sustaining explosions as dust clouds dispersed in air and some dusts were even capable of sustaining explosions when dispersed in nitrogen. The finest sizes of explosives dusts were less reactive than the larger sizes; this is opposite to the particle size effect observed previously for the pure fuel dusts. The data for the explosives dusts were compared to those for pure fuel dusts. 27 refs., 47 figs.

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT We present evidence that differences in soil seedbank persistence among pioneer plants in the cloud forest of Monteverde, Costa Rica, are influenced by differences in seed chemical defense. We used extracted seed chemicals from Bocconia frutescens (Papaveraceae), Guettarda poasana (Rubiaceae), Phytolacca rivinoides (Phytolaccaceae), Urera elata (Urticaceae), Cecropia polyphlebia (Cecropiaceae), and Witheringia meiantha (Solanaceae) to assess seed chemical defense in two ways: (1) a plant pathogen inhibition assay using Pythium irregulare; and (2) a brine shrimp toxicity assay using Artemia salina. The combined performance of each species in the two assays positively correlated with seedbank persistence. In the pathogen assay, mycelium growth was reduced when Pythium was cultured o...

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We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at {gamma}{gamma} colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of {mu}{sup +}{mu}{sup -}, {tau}{sup +}{tau}{sup -}, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan{beta}-bar 5 (30) and large (small) charged Higgs-boson masses.

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I present an overview of the measurement of the proton form factors in the time-like regiun. BABAR has recently measured with great accuracy the e{sup +} e{sup -} {yields} p p-bar reaction from productiun threshold up to an energy of {approx} 4.5 GeV; finding evidence for a ratio of the electric to magnetic form factur greater than unity, contrary to expectation. In agreement with previous measurements. BABAR confirmed the steep rise uf the magnetic form factor close to the p p-bar mass threshold, suggesting the possible presence of an under-threshuld N N-bar vector state. These and uther open questiuns related to the nucleon furm factors both in the time-like and space-like region, wait for more data with different experimental techniques to be possibly solved.

Energy Technology Data Exchange (ETDEWEB)

At the LEAR facility, CERN, antiprotonic L{alpha} transitions in light elements have been investigated with a focussing crystal spectrometer. The high resolution of the experiment allowed for the first time to resolve in p-barH the 2{sup 3}P{sub 0} state from the close lying states 2{sup 3}P{sub 2}, 2{sup 1}P{sub 1}, and 2{sup 3}P{sub 1}. In p-barD the corresponding transitions were found to be more than an order of magnitude broader. To a large extent the results for p-barH support the meson exchange model.

Energy Technology Data Exchange (ETDEWEB)

Direct Flame Impingement involves the use of an array of very high-velocity flame jets impinging on a work piece to rapidly heat the work piece. The predominant mode of heat transfer is convection. Because of the locally high rate of heat transfer at the surface of the work piece, the refractory walls and exhaust gases of a DFI furnace are significantly cooler than in conventional radiant heating furnaces, resulting in high thermal efficiency and low NOx emissions. A DFI furnace is composed of a successive arrangement of heating modules through or by which the work piece is conveyed, and can be configured for square, round, flat, and curved metal shapes (e.g., billets, tubes, flat bars, and coiled bars) in single- or multi-stranded applications.

Science.gov (United States)

Probabilistic sensitivities using the score function method are developed for a lifing analysis of an alpha + beta titanium alloy in a round bar under axial fatigue load. Sensitivities with respect to the statistical inputs of the crack initiation size (a...

Energy Technology Data Exchange (ETDEWEB)

The microstructural development inside the stress induced martensite (SIM) variants in Ti-Ni-Nb alloy with various degrees of deformation have been revealed by electron microscopic observations. The orientation relationship between the SIM and the parent phase has been found: [1{bar 1}0]{sub M}{parallel}[11{bar 1}]{sub B2}, (001){sub M} 5{degree} away from (101){sub B2}. The lattice invariant shear of the SIM variants at the slightly deformed stage is dominantly (11{bar 1}) Type I twin. Besides the ordinary slip, the adjustment and development of the internal secondary twinning from (11{bar 1}) Type I twin to {l_angle}011{r_angle} Type II/ or (011) Type I twin, (001)compound twin and (111) Type I twin happen concurrently or in combination inside the SIM variants with the further deformation. The corresponding deformation mechanisms include stress induced reorientation of SIM substructural bands by the ...

CERN Document Server

The CKM angle $\\gamma/\\phi_{3}$ had been measured by two B-factories, the PEPII collider for the BaBar experiment and the KEKB collider for the Belle experiments. The present paper reports recent progress in $\\gamma/\\phi_{3}$.

Energy Technology Data Exchange (ETDEWEB)

A measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV in the dilepton final states using a lepton+track selection and secondary vertex b-tagging is presented. One of the two leptons from the decay of the t{bar t} pair is allowed to be identified only as an isolated track to improve the selection efficiency. The result is combined with a measurement in the t{bar t} {yields} e{mu} final state. The measurements are based on 370 pb{sup -1} of data collected with the D0 experiment at the Tevatron collider. The preliminary cross section obtained in the combined lepton+track and e{mu} channel is: {sigma}{sub t{bar t}} = 8.6{sub -1.7}{sup +1.9}(stat) {+-} 1.1(syst) {+-} 0.6(lumi) pb.

Energy Technology Data Exchange (ETDEWEB)

This patent describes a display unit of a speedometer for an automobile, comprising: a constant speed running circuit capable of producing output signals indicative of a desired car speed; an actual car speed operational circuit capable of producing output signals indicative of actual car speed; a comparing circuit for comparing the amplitudes of the output signals of the constant speed running operational circuit and the actual car speed operational circuit; bar graph decoders receiving the output signals from the constant speed running operational circuit and the actual car speed operational circuit; an EX-OR circuit having inputs coupled to respective bar graph decoders and having an output; and OR circuit having inputs coupled to respective bar graph decoders and having an output; selector means coupled to the output of the EX-OR circuit and the output of the OR circuit and controlled by an output of the comparing means ...

UK PubMed Central (United Kingdom)

BackgroundGenotyping analysis using capillary DNA sequencing with fluorescently labeled primer pairs obtained by polymerase chain reaction (PCR) is widely used, but is expensive....Full Text Available

Science.gov (United States)

Feb 6, 2009 ... 2nd, Dr. Bob's Cosmic Cowboy Cookers. 3rd, Mega Hurts Chili. 4th, B.A.R.F. Cooking Team of America. 5th, Cellar Bar ...

Science.gov (United States)

The Knight shift of vanadium (KV) in fine V3Si particles was studied. The average diameter (\\bar{d}) ranged from 60 to 8000 A. The strong temperature dependence of the KV characteristic of high-Tc A-15 compounds was weakened in the particles. KV at 77 K increased with a decrease in \\bar{d}. The above-mentioned trends were consistent with a broadening of the sharp peak in the electronic density of states around the Fermi energy in particles resulting from a perturbation of the surface.

Energy Technology Data Exchange (ETDEWEB)

At future {gamma} {gamma} colliders a massive production of tt-bar pairs is possible. This would allow a detailed investigation of the interactions involving the top quark. The authors propose some correlations which are sensitive to tt-bar final state interactions and compute the QCD and standard model Higgs boson contributions to these correlation. QCD-induced transverse polarization of top quarks is found to be sizeable and measurable at a high-energy e{sup +} e{sup -} collider with an integrated luminosity of 10(fb){sup -1} which is converted into a photon collider by backscattering of laser photons. 16 refs.

International Nuclear Information System (INIS)

TVA is currently engaged in an extensive program to mitigate steam generator tube denting at the Sequoyah Nuclear Plant, which is in commercial operation, and to prevent or minimize the onset of denting at the Watts Bar Nuclear Plant, which is under construction. This paper describes TVA's denting mitigation program, which is primarily feedwater chemistry and system operation improvement, and the effect the changes that have been implemented have had on the incidence as well as the progression rate of steam generator tube denting during the past 220 effective full power days of Sequoyah unit 1 operation.

Energy Technology Data Exchange (ETDEWEB)

We study heavy physics effects on the Higgs production in {gamma}{gamma} fusion using the effective Lagrangian approach. We find that the effects coming from new physics may enhance the standard model predictions for the number of events expected in the final states {bar {ital b}}{ital b}, {ital WW}, and {ital ZZ} up to one order of magnitude, whereas the corresponding number of events for the final state {bar {ital t}}{ital t} may be enhanced up to two orders of magnitude. {copyright} {ital 1996 American Institute of Physics.}

International Nuclear Information System (INIS)

Beta-C trademark is a metastable beta titanium alloy which can be heat treated to achieve a good combination of properties such as tensile strength, fatigue strength, ductility and toughness, such as needed in aircraft fasteners. Variations in hot and cold processing parameters and solution heat treatment can affect the resultant grain structure which in turn affects subsequent aging response and mechanical properties. Several processing/heat treating routes on round bar are explored in this study to determine the effects on microstructure and various mechanical properties.

Science.gov (United States)

Visible-emitting high-power laser bars are investigated at an emission wavelength of 640 nm. AlGaInP/GaInP, single tensile-strained quantum well, separate confinement heterostructures are fabricated into one cm long laser bars using a 0.7 fill factor. The low threshold current of the diode, combined with the aggressive heatsinking of a silicon microchannel cooler has resulted in more than 12 W of continuous wave output power.

Energy Technology Data Exchange (ETDEWEB)

Most general tbW couplings were investigated in the process {gamma}{gamma} {yields} tt-bar {yields} l{sup {+-}}X for unpolarized photon beams. The double angular and energy distribution of the lepton was calculated and an optimal-observable analysis on it was carried out for the SM tt-bar production mechanism. It was also shown that the leptonic angular distribution is insensitive to non-standard tbW vertex. That means that observation of non-standard effects indicates existence of some new physics in the production part.

CERN Document Server

We have conducted a systematic investigation of the origin and underlying physics of the line--line and line--continuum correlations of AGNs, particularly the Baldwin effect. Based on the homogeneous sample of Seyfert 1s and QSOs in the SDSS DR4, we find the origin of all the emission-line regularities is Eddington ratio (L/Ledd). The essential physics is that L/Ledd regulates the distributions of the properties (particularly column density) of the clouds bound in the line-emitting region.

Science.gov (United States)

... 70 1.8732 1.2850 1.1444 0.9827 0.9636 0.9432 1.0933 1.2966 1.3144 1.3848 70 - 80 1.9312 1.6688 1.4502 1.2072 1.0180 1.0234 1.1492 1.3264 1.4317 1.4328 ...

Energy Technology Data Exchange (ETDEWEB)

The mainly instationary operation of a solar heated receiver can be simulated with sufficient accuracy only if data about the dynamic behavior are available. For this reason, the dynamic behavior of a solar cavity receiver with parabolic dish collector is investigated. The development of a mathematical simulation considering heat transfer and storage processes is presented and the procedure for a numerical solution is illustrated. The performance of the calculation method is finally demonstrated by simulating the passage of a cloud.

International Nuclear Information System (INIS)

Using high resolution and high sensitivity IRAS data at 12 and 25 microns low mass stars were studied which have recently formed in the Ophiuchus, Corona Australis, and IC1396 dark clouds. The successful application of these techniques to the Rho Ophiuchi infrared cluster is briefly described. The status of research performed is also presented.

International Nuclear Information System (INIS)

CNPT-3 is the laboratory designation of a strain of bacteria that reproduces best at deep-sea pressures. It was isolated from a sample collected at a 5800 m depth of the Pacific Ocean. This isolation was achieved from a sample that had been retrieved without warning. This year we demonstrated that there are similarly behaving bacteria that can be isolated from samples even when retrieved with decompression. The purpose of this project was to define the temperatures and pressures over which CNPT-3 can exist and function. (1) At 2"0C CNPT-3 is eurybathic from about 1000 to 6500 m, as judged from an only slightly pressure dependent generation time. (2) CNPT-3 is unquestionably barophilic at 2"0C, with doubling times of 9 hours at 580 bars and over 18 hours at 1 bar. (3) At 10"0C, reproduction is adversely affected at 1 bar to the extent that CNPT-3 becomes obligately barophilic at 10"0C. Yet reproduction is enhanced above 280 ...

International Nuclear Information System (INIS)

Stellar rotation and velocity-dispersion measurements are presented for the bulge components of the SBO galaxies NGC 1023, 2859, 2950, 4340, 4371, and 7743. The kinematics of nine SB bulges with data available are compared with bulges of unbarred galaxies studied by Kormendy and Illingworth. All of the SB bulges are found to rotate at least as rapidly as oblate-spheroid dynamical models which are flattened by rotation. This result confirms the conclusion of Kormendy and Illingworth that bulges rotate very rapidly. Six SB bulges found by Kormendy and Koo to be triaxial rotate even more rapidly than the oblate models. In this respect, they resemble published n-body models of bars. That is, triaxial bulges are dynamically like bars and unlike elliptical galaxies, which are also believed to be triaxial, but which rotate slowly. Measured velocity anisotropies are found to be consistent with these conclusions. Two ordinary bulges whose rotation is ...

International Nuclear Information System (INIS)

Numerical simulations show that box-shaped bulges of edge-on galaxies are not bulges: they are bars seen side-on. Therefore, the two components that are seen in edge-on Sb galaxies such as NGC 4565 are a disk and a bar. But face-on SBb galaxies always show a disk, a bar, and a (pseudo)bulge. Where is the (pseudo)bulge in NGC 4565? We use archival Hubble Space Telescope H-band images and Spitzer Space Telescope 3.6 #mu#m wavelength images, both calibrated to Two Micron All Sky Survey K_s band, to penetrate the prominent dust lane in NGC 4565. We find a high surface brightness, central stellar component that is clearly distinct from the boxy bar and from the disk. Its brightness profile is a Sersic function with index n = 1.55 #+-# 0.07 along the major axis and 1.33 #+-# 0.12 along the minor axis. Therefore, it is a pseudobulge. It is much less luminous than the boxy bar, so the true ...

Science.gov (United States)

The in-flight wavelength calibration for the Ozone Monitoring Instrument is discussed. The observed variability in the wavelength scale is two orders of magnitude larger than caused by temperature changes in the instrument. These wavelength variations are the result of rapid changes in time in the radiance levels during an individual observation in the presence of clouds or snow and ice. We have developed a data processing method to account and correct for these changes. In February 2005 this correction was implemented in the official data processing stream. We explain in detail how and how accurately this method works. Before correction, the error in the wavelength scale can be as much as a few tenths of a pixel; after correction it is mostly less than 1/100th of a pixel, which is the required preflight accuracy. This means that higher-level products such as the total column amounts of ozone, NO2, and SO2 are not significantly affected. It is expected that these ...

Energy Technology Data Exchange (ETDEWEB)

The phenomena and effects of airblast, ground shock, thermal radiation, cratering and ejecta, and debris cloud and deposition from the eruption of Mt. St. Helens were compared to those that would result from a nuclear explosion to determine if phenomena or effects were analogous and thus might provide useful data for military nuclear weapon effects studies. It is concluded that the phenomena are not analogous. In particular, airblast destruction was caused by clouds of ash driven by subsonic winds, rather than by a supersonic shock wave that would be the damage mechanism of a nuclear explosion. Because of the lack of analogy between the eruption and nuclear explosion phenomena, it appears questionable that any of the effects are analogous; therefore, it is unlikely that anything more of military interest can be gained from studying the effects of the eruption. However, key contacts for further information on the eruption and the associated ...

CERN Document Server

We present a study of 66 barred, early-type (S0-Sb) disk galaxies, focused on the disk surface brightness profile outside the bar region and the nature of Freeman Type I and II profiles, their origins, and their possible relation to disk truncations. This paper discusses the data and their reduction, outlines our classification system, and presents $R$-band profiles and classifications for all galaxies in the sample. The profiles are derived from a variety of different sources, including the Sloan Digital Sky Survey (Data Release 5). For about half of the galaxies, we have profiles derived from more than one telescope; this allows us to check the stability and repeatability of our profile extraction and classification. The vast majority of the profiles are reliable down to levels of mu_R ~ 27 mag arcsec^-2; in exceptional cases, we can trace profiles down to mu_R > 28. We can typically follow disk profiles out to at least 1.5 times the ...

Energy Technology Data Exchange (ETDEWEB)

Evaluates experiments aimed at selecting optimum design and technical specifications of a support system for junctions of gate roads and longwall faces mined by shearer loaders and powered supports. A set of supports used at a junction of a working face and a gate road consisted of 2 supports (each made up of a roof bar and two hydraulic props). Roof bar length ranged from 4.0 to 5.5 m and from 7.0 to 9.0 m respectively. The support roof bars were parallel to the longitudinal axis of a gate road. Stress distribution in strata surrounding a junction of a working face and a gate road was analyzed. The finite element method was used. Convergence of the roof and the floor of a gate road depending on support yield strength and distance from a measuring point to the supports was analyzed. Recommendations are made for optimum yield strength of the supports. Nomograms for selecting optimum support yield strength are given. ...

International Nuclear Information System (INIS)

The nuclear magnetic susceptibility, #chi#, of "3He is seen to nearly obey a pure Curie Law, #chi# = C/T, over the temperature range 0.5 mK < T < 2 K when contained in the 20#ALPHA#, multiply connected pores of Vycor glass at low external pressure. Raising the external pressure to 5 bar (1 bar 100 kPa) causes the susceptibility to obey the Curie-Weiss law, #chi# = C' /T - #THETA# whose #THETA# = 0.3 mK. The longitudinal relaxation time, T_1, varies monotonically with T between 17 and 90 ms at both pressures. At 5 bar, the transverse relaxation time T_2*, is nearly temperature independent (about 600 #mu#s) above 2 mK. Below 2 mK, T_2* drops precipitously. Preliminary measurements indicate that the magnetism is produced by atoms that can flow through the pores of the Vycor glass. (10 refs., fig.).

International Nuclear Information System (INIS)

Microsecond pulse radiolysis of oxygenated aqueous solutions containing 0.02 mol dm"-"3 sodium formate and 2 mmol dm"-"3 phosphate buffer at pH 7 was used to generate superoxide anion radicals. The influence of some biologically important compounds upon the rate of O_2"."-"b"a"r decay as monitored spectrophotometrically in the range of 245-300 nm. Hematoporphyrin (HP), hemin C (HC), catalase (Cat), cobalt sulfophthalocyanine (CoTSPc) were studied. Among the investigated compounds only Cat was found to show a high catalytic efficiency towards the self-decay of O_2"."-"b"a"r. A red shift of 0_2"."-"b"a"r absorption band and slowing down of its decay were observed to take place by adding HP or CoTSPc to the solutions containing formate ions in excess. This effect is associated with the formation of a transient superoxo-complex. An appearance of an intermediate species with absorption maxima at 350 nm and half-life of about 2 s ...

Science.gov (United States)

The previously unknown property of the optical speckle pattern reported. The interference of a speckle with the counterpropagating phase-conjugated (PC) speckle wave produces a randomly distributed ensemble of a twisted entities (ropes) surrounding optical vortex lines. These entities appear in a wide range of a randomly chosen speckle parameters inside the phase-conjugating mirrors regardless to an internal physical mechanism of the wave-front reversal. These numerically generated interference patterns are relevant to the Brillouin PC mirrors and to a four-wave mixing PC mirrors based upon laser trapped ultracold atomic cloud.

Energy Technology Data Exchange (ETDEWEB)

Results of analytical study of early stages of a single star evolution are used investigation of the rotational fragmentation of the collapsing gas-dust cloud which leads to formation of two types of binaries. Wide ..cap alpha..-systems (Psub(orb) > or approximately 100 yrs) with usually unequal masses of components are formed before the formation of gas-dust core in hydrostatical equilibrium. Close ..beta..-systems (Psub(orb) < or approximation 100 yrs) with usually nearly equal masses of components are formed in the course of the collapse of gas-dust core.

CERN Document Server

The open source Scala language is a Java--based dynamic scripting, functional programming language. Moreover, this highly scalable scripting language lends itself well to building Cloud--based/deliverable Software as a Service (SaaS) online applications. Written by Lift Scala web framework founder and lead Dave Pollak, Beginning Scala takes a down--to--earth approach to teaching Scala that leads you through simple examples that can be combined to build complex, scalable systems and applications. This book introduces you to the Scala programming language and then guides you through Scala constr

Energy Technology Data Exchange (ETDEWEB)

Anthropogenic sulfate aerosol, together with particles from biomass burning, may significantly reduce the climatic warming due to man-made greenhouse gases. The radiative forcing of aerosol particles is based on their ability to scatter and absorb solar radiation (direct effect), and on their influences on cloud albedos and lifetimes (indirect effect). The direct aerosol effect depends strongly on the size, number and chemical composition of particles, being greatest for particles of 0.1-1 {mu}m in diameter. The indirect aerosol effect is dictated by the number of particles being able to act as cloud condensation nuclei (CCN). For sulfate particles, the minimum CCN size in tropospheric clouds is of the order of 0.05-0.2 {mu}m. To improve aerosol parameterizations in future climate models, it is required that (1) both primary and secondary sources of various particle types will be characterized at a greater accuracy, and (2) ...

CERN Document Server

In the littlest Higgs model with T-parity (LHT) the mirror quarks induce the special flavor structures and some new flavor-changing (FC) couplings which could greatly enhance the production rates of the FC processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider (ILC), i.e., $e^+e^-\\rightarrow b\\bar{s}$ and $\\gamma\\gamma\\rightarrow b\\bar{s}$. The results show that the production rates of these processes are sizeable for the favorable values of the parameters. Therefore, it is quite possible to test the LHT model or make some constrains on the relevant parameters of the LHT through the detection of these processes at the ILC.

International Nuclear Information System (INIS)

The future e"+e"- linear colliders can also operate in the e#gamma# or #gamma##gamma# modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process #gamma##gamma# #-># tb-bar#PI#_t"-. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode #PI#_t"- #-># bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in #gamma##gamma# mode at the TeV energy scale

Energy Technology Data Exchange (ETDEWEB)

A high pressure piezometer is described with which pVT-measurements on solutions of gases in liquids like oils can be performed at pressures and temperatures up to 2000 bar and 440 K, respectively. The present investigations deal mainly with the system squalaneCO/sub 2/ at different mole fractions, but also with squalaneN/sub 2/. The high accuracy of the measurements reveals a pronounced structure of the pV-curves in dependence on temperature and mole fraction. At larger mole fractions is the unequivocal assignment of the phases ambiguous, and the representation of the experimental data in terms of an equation of state not possible for the whole pressure and temperature range. However, for solutions with lower mole fractions could be determined the saturation pressures and the isothermal compressibility in the unsaturated region. Furthermore, the molar excess volumes of the mixture have been calculated and the phase behaviour has been discussed briefly. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Four commercial stainless steels (mat. Nos. 1.4539, 1.4586, 1.4571 and 1.4462) were tested in 96% and 90% sulfuric acid of 80/sup 0/C as to their corrosion fatigue strength by subjecting notched round bars to the rotary bending test. At the same time, the efficiency of anodic protection was examined. With all four steels, the alternating bending strength obtained in the air is essentially reduced. The semiaustenitic steel Nr. 1.4462 shows a lower corrosion fatigue strength than the three austenitic steels. Although making the corrosion fatigue strength of steels better calculable, anodic protection proves insufficient to completely prevent notched round bars from corrosion fatigue in concentrated sulfuric acid.

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is the study of the heat transfer and of thermal behaviour of the HF (high frequency) components (in fact capacitors) of the ITER-proto-2005-FCI antenna. Preliminary results carried out with the Castem software show that it is possible to cool the hottest part of the antenna efficiently. A water flow (1 bar, 25 Celsius degrees) or an helium flow (10 bars, 50 Celsius degrees) permit to limit the maximal value of the temperature to 270 Celsius degrees. A second software Ansys has allowed the author to simulate capacitors with more complicated shapes. (A.C.)

British Library Electronic Table of Contents (United Kingdom)

The Quantou Formation recovered by CCSD-SK-Is borehole (China Cretaceous Continental Scientific Drilling-SongkeI-the south borehole) is 132.07 m long and the recovery of cores is 100%. The sequence and process of lithology-lithofacies and cyclostratigraphy are revealed by a detailed core description. Nine rock types and three kinds of sedimentary facies including meandering river, shallow lake, and delta front are recognized from the drilling core, there are ten sedimentary microfacies, which are point bar, natural levee, crevasse splay, crevasse channel, floodplain, flood lake, distributary mouth bar, interdistributary bay, mudstone of still water, and turbidite. The Quantou Formation represents seventy-six meter-scale cycles (sixth-order cycle), twenty-five fifth-order cycles, eight four...

CERN Document Server

A new calculation of the $\\bar{p}/p$ ratio in cosmic rays is compared to the recent PAMELA data. The good match up to 100 GeV allows to set constraints on exotic contributions from thermal WIMP dark matter candidates. We derive stringent limits on possible enhancements of the WIMP \\pbar flux: a $m_{\\rm WIMP}$=100 GeV (1 TeV) signal cannot be increased by more than a factor 6 (40) without overrunning PAMELA data. Annihilation through the $W^+W^-$ channel is also inspected and cross-checked with $e^+/(e^-+e^+)$ data. This scenario is strongly disfavored as it fails to simultaneously reproduce positron and antiproton measurements.

British Library Electronic Table of Contents (United Kingdom)

The objective of this study is to describe the complete transport chain of CO2 between capture and storage including a ship transport. This last one is composed by the following steps:Shore terminal including the liquefaction, temporary storage and CO2 loading. Ship with a capacity of 30,000m^3. On or off shore terminal including an unloading system, temporary storage and export towards the final storage. Between all the possible thermodynamic states, the liquid one is most relevant two options are compared in the study (-50^oC, 7bar) and (-30^oC, 15bar). The ship has an autonomy of 6 days, is able to cover 1000km with a cargo of 2.5Mt/year. Several scenarios are studied varying the geographical position of the CO2 source, the number of harbours and the way the CO2 is finally stored. Depen...

Energy Technology Data Exchange (ETDEWEB)

SC-CO/sub 2/ extraction of oil from peanuts is an alternative to hexane extraction or the mechanical oil press. Oil was successfully extracted using SC-CO/sub 2/ at temperatures of 25-120/sup 0/C and pressures of 140 -690 Bar. Pressure, temperature and particle size affected the extraction of oil. In the range studied, the highest values of temperature and pressure gave highest solubilities.

Energy Technology Data Exchange (ETDEWEB)

The paper industry needs alternative waste disposal methods rather than dumping sites. The combustion properties of these waste materials make them suitable for thermal disposal. A process has been developed in which the waste materials are burnt on an oscillating bar grate without supplying external energy. Electrical energy and process steam are generated while small amounts of a sintered slag remain behind. (orig.).

International Nuclear Information System (INIS)

Quark models of production of cumulative particles and the EMC effect are analyzed. It is shown that all these models are characterized by a universal relation between the spectrum of cumulative nucleons and the cross section for cumulative particles containing valence quarks of the nucleus. This relation is tested for the deuteron, and the role of secondary nuclear processes for heavy nuclei is discussed. It is noted that the ''sea'' cumulative particles (K"-, p-bar) are particularly important for understanding the nature of the difference between the structure functions of a nucleus and of a free nucleon.

International Nuclear Information System (INIS)

Future #gamma##gamma# colliders allow the production of the heavy neutral MSSM Higgs bosons H and A as single resonances. The prospects of finding these particles in the bb-bar and the neutralino-pair final states have been analyzed. The H, A bosons can be discovered for medium values of tan #beta# with masses up to 70-80% of the initial e"#+-#e"- c.m. energy. This production mode thus covers parts of the supersymmetric parameter space that are not accessible at other colliders.

CERN Document Server

We show that on any abelian scheme over a complex quasi-projective smooth variety, there is a Green current for the zero-section, which is axiomatically determined up to $\\partial$ and $\\bar\\partial$-exact differential forms. This current generalizes the Siegel functions defined on elliptic curves. We prove generalizations of classical properties of Siegel functions, like distribution relations, limit formulae and reciprocity laws.

Index Scriptorium Estoniae

Uutest heliplaatidest Jamiroquai "Dynamite", Wallflowers "Rebel, Sweetheart", Corgan, Billy "The Future Embrace", Mariza "Transparente", Turin Brakes "JackinABox", Hellacopters "Rock& Roll is Dead", Belle & Sebastian "Push bar To Open Old", Farmer, Mylene "Avant Guel'ombre", Kreck "If You Live", Dream Theater "Octavarium"

CERN Document Server

Using data collected with the BESII detector at $e^{+}e^{-}$ storage ring Beijing Electron Positron Collider, the measurements of relative branching fractions for seven Cabibbo suppressed hadronic weak decays $D^0 \\to K^- K^+$, $\\pi^+ \\pi^-$, $K^- K^+ \\pi^+ \\pi^-$ and $\\pi^+ \\pi^+ \\pi^- \\pi^-$, $D^+ \\to \\bar{K^0} K^+$, $K^- K^+ \\pi^+$ and $\\pi^- \\pi^+ \\pi^+$ are presented.

CERN Document Server

We calculated the matter effect, including both the Earth and supernova, on the detection of neutrinos from type II supernovae at the proposed Daya Bay reactor neutrino experiment. It is found that apart from the dependence on the flip probability P_H inside the supernova and the mass hierarchy of neutrinos, the amount of the Earth matter effect depends on the direction of the incoming supernova neutrinos, and reaches the biggest value when the incident angle of neutrinos is around 93^\\circ. In the reaction channel \\bar{\

International Nuclear Information System (INIS)

Quark models of cumulative particle production and EMS effect are analyzed. All the models are characterized by a universal relationship between the spectrum of cumulative nucleons and the cross section of cumulative particles containing valence nuclear quarks. This relationship is tested for a deuteron. The role is discussed played by secondary nuclear processes for heavy nuclei. A special role of ''sea'' cumulative particles (K"-, p-bar) is pointed out in understanding the nature of the difference between the structure functions of a nucleus and of free nucleon.

Energy Technology Data Exchange (ETDEWEB)

The correlation between baryon number and strangeness elucidates the nature of strongly interacting matter. This diagnostic can be extracted theoretically from lattice QCD calculations and experimentally from event-by-event fluctuations. The analysis of present lattice results above the critical temperature severely limits the presence of q{bar q} bound states, thus supporting a picture of independent (quasi)quarks. Details may be found in [1].

International Nuclear Information System (INIS)

Time-odd parton distribution functions in a Drell-Yan process are here studied by examining the evolution of the internal statistical properties of the interacting hadrons. Time-odd functions are shown to be a signature of the irreversible process in which a hadronic state characterized by long range correlation properties (hadronic phase) decays to produce a cloud of independent partons (partonic phase) because of initial/final state interactions. The relevant considered variable is the rate of increase of the entropy of the hadronic system. This quantity is shown to be roughly equal to the decay rate of the hadronic state. Conditions for getting a leading twist time-odd effect are established on this basis. Last, the relevant case of a large entropy increase associated with transverse-dominated initial/final state interactions is analyzed.

International Nuclear Information System (INIS)

The spectre of major climate change caused by the greenhouse effect has generated intensive research, heated scientific debate and a concerted international effort to draft agreements for the reduction of greenhouse gas emissions. This report of Scientific Perspectives on the greenhouse problem explains the technical issues in the debate in language readily understandable to the non-specialist. The inherent complexities of attempts to simulate the earth's climate are explained, particularly with regard to the effects of clouds and the circulation of the oceans, which together represent the largest factors of uncertainty in current global warming forecasts. Results of the search for the 'greenhouse signal' in existing climate records aredescribed in chapter 3 (part two). Chapter 5 (part two) develops a projection of 21st-century warming based on relatively firm evidence of the earth's actual response to known increases in greenhouse gas emissions during the last 100 ...

International Nuclear Information System (INIS)

We describe a position sensitive photon counting microchannel plate based detector with an improved quadrant anode (QA) readout system. The technique relies on a combination of the four planar elements pattern and an additional fifth electrode. The charge cloud induced by single particle detection is split between the electrodes. The measured charge values uniquely define the position of the initial event. QA has been first published in 1976 by Lampton and Malina. This anode configuration was undeservedly forgotten and its potential has been hardly underestimated. The presented approach extends the operating spatial range to the whole sensitive area of the microchannel plate surface and demonstrates good linearity over the field of view. Therefore, the novel image sensor results in spatial resolution better then 50?m and count rates up to one million events per second.

Science.gov (United States)

A position-sensitive event-counting electronic readout system for microchannel plates (MCPs) is described that offers the advantages of high spatial resolution and fast time resolution. The technique relies upon a four-quadrant electron-collecting anode located behind the output face of the microchannel plate, so that the electron cloud from each detected event is partly intercepted by each of the four quadrants. The relative amounts of charge collected by each quadrant depend on event position, permitting each event to be localized with two ratio circuits. A prototype quadrant anode system for ion, electron, and extreme ultraviolet imaging is described. The spatial resolution achieved, approx. =10 ..mu.., allows individual MCP channels to be distinguished. (AIP)

CERN Document Server

We summarize and extend recent work on the theory of extrasolar giant planets (EGPs) and brown dwarfs, paying particular attention to Gliese 229 B, the albedos of EGPs, the compositions of substellar atmospheres, the connections with the giant planets in the solar system, cloud physics, and non-gray spectral synthesis. The role of condensates in altering the optical spectrum of Gliese 229 B is explored, as are the systematics of the reflection spectra from extrasolar giant planets near their primaries. In addition, we discuss the role of convection and disequilibrium chemistry in explaining the anomalous detection of CO in Gliese 229 B. Throughout, we highlight the distinctive chemistry that defines this new class of objects and set goals for future study.

British Library Electronic Table of Contents (United Kingdom)

Land cover change can be caused by human-induced activities and natural forces. Land cover change in watershed level has been a main concern for a long time in the world since watersheds play an important role in our life and environment. This paper is focused on how to apply Landsat Multi-Spectral Scanner (MSS) satellite image of 1973 and Landsat Thematic Mapper (TM) satellite image of 2001 to determine the land cover changes of coastal watersheds from 1973 to 2001. GIS and remote sensing are integrated to derive land cover information from Landsat satellite images of 1973 and 2001. The land cover classification is based on supervised classification method in remote sensing software ERDAS IMAGINE. Historical GIS data is used to replace the areas covered by clouds or shadows in the image o...

Energy Technology Data Exchange (ETDEWEB)

Ferroelectric disks, coated with proper electrodes, can easily produce a dense plasma cloud when excited with a high-voltage pulse. This plasma can be a source of either electrons or ions depending on the sign of the extracting field set in front of the disk. We present the behavior of the disks operating at high frequency as emitters of both electrons and ions in two experimental configurations: (a) without and (b) with two screening grids. These two screening grids are inserted when the plasma must be confined within the cathode region. The system is capable of providing ion pulses of a few hundred milliamperes, whose length can range from a hundred nanoseconds to dozen microseconds. The electron pulses of energetic electrons have typically an amplitude higher than a couple of amperes. Tests at MHz repetition rate were positive as for stable operation.

International Nuclear Information System (INIS)

A particle-laden turbulent reacting flow model is described and applied to in-furnace, dry SO_2 control in boilers. Sulfur capture by calcium-based sorbents is represented by a shrinking core model which accounts for surface areas loss and product layer diffusion. Sorbent particle trajectories and dispersion are followed with cloud statistics in a Lagrangian framework. The turbulent fluid mechanics and chemical reactions are coupled, and solutions obtained for mean and fluctuating velocity, composition, and particle position. Comparisons are made with data from an US EPA laboratory reactor. Practical implications for SO_2 control are examined including the effects of jet velocity, sorbent injection location, boiler load and thermal profiles.

Energy Technology Data Exchange (ETDEWEB)

The interaction of thermal radiation with conduction and convection in thermally developing absorbing, emitting, nongray gas-particulate turbulent suspension flow through a circular tube is investigated. The contribution of thermal radiation is obtained through evaluation of the total hemispherical emittance of the particulate cloud and through evaluation of single band absorptances for molecular gases, modified to account for the interaction with the particles. The governing differential equation is derived as a (nonlinear) energy equation, coupled with integral equations to find the thermal radiation contributions. The energy equation is solved numerically by an implicit finite difference method with an iterative procedure. Qualitative results for Nusselt numbers are shown for a variety and range of parameters, such as optical thickness of particulates and single molecular gas bands, relative gas band position and band width, and temperature ratios (heated as ...

Energy Technology Data Exchange (ETDEWEB)

A circumsolar telescope for determining the flux of energy from the sun and from the circumsolar region as a function of angle, wavelength, and atmospheric conditions is presented. The telescope system consists of a specially designed scanning telescope, an electronic control and recording system and some auxiliary equipment. The detector is a pyroelectric crystal, a type of thermal detector, thus the fundamental measurement is relatively wavelength insensitive. The telescope is designed to provide data for all weather conditions during which a concentrating solar energy system would be operating. Analyses show that for a clear blue sky, the amount of radiation coming directly from the sun, while for a sky with thin clouds or haze, the circumsolar radiation is some 25% of the direct solar radiation. Under such conditions a measure of the circumsolar radiation is necessary for an accurate prediction of the performance of a concentrating solar energy system.

British Library Electronic Table of Contents (United Kingdom)

Seven villages in southeastern Kenya surround Mt. Kasigau and depend on the mountain's cloud forest for their water supply. Five of these villages have regularly experienced water shortages, and all village water supplies were contaminated with Escherichia coli bacteria. There is a need to economically find new sources of fresh ground water. Remote sensing offers a relatively quick and cost-effective way of identifying areas with high potential for ground water development. This study used spectral properties of features on Landsat remote sensing imagery to map linear features, soil types, surface moisture, and vegetation. Linear features represented geologic or geomorphologic features indicating either shallow ground water or areas of increased subsurface hydraulic conductivity. Regarding...

CERN Document Server

Several complex organic molecules are routinely detected in high abundances towards hot cores and hot corinos. For many of them, their paths of formation in space are uncertain, as gas phase reactions alone seem to be insufficient. In this paper, we investigate a possible solid-phase route of formation for methyl formate (HCOOCH3). We use a chemical model updated with recent results from an experiment where simulated grain surfaces were irradiated with 200 keV protons at 16 K, to simulate the effects of cosmic ray irradiation on grain surfaces. We find that this model may be sufficient to reproduce the observed methyl formate in dark clouds, but not that found in hot cores and corinos.

Energy Technology Data Exchange (ETDEWEB)

The densities for binary mixtures of dichloromethane with aniline, or nitrobenzene, respectively, including those of pure liquids, were measured over the entire composition range at T = (288.15, 293.15, 298.15, and 303.15) K and atmospheric pressure using a vibrating-tube densimeter. From the experimental results, the excess molar volumes, V{sub m}{sup E}, partial molar volumes, V{sub i}-bar, the apparent molar volume, V{sub {phi}}{sub i}, and the partial molar excess volumes at infinite dilution, (V{sub i}{sup E}-bar){sup {infinity}}, were calculated over whole composition range. Negative values of V{sub m}{sup E} for (dichloromethane + aniline) attributed to the formation of the charge transfer complex, while for (dichloromethane + nitrobenzene) system, the free volume effect played a dominant role. The extent of negative deviations in V{sub m}{sup E} values follows the order: nitrobenzene > aniline. The Prigogine-Flory-Patterson (PFP) ...

International Nuclear Information System (INIS)

A series of tests has been carried out to determine the operating conditions required to remove the corrosion deposit from samples cut from Winfrith Steam Generating Heavy Water Reactor (WSGHWR) primary circuit pipework by submerged water jetting. Two types of samples were used - one set subjected to the normal annual reactor decontamination using TURCO reagents, the other set having been given a LOMI treatment in addition. Tests showed that useful decontamination factors could be achieved on both types of sample, but significantly less severe operating conditions were required to decontaminate the LOMI treated samples. A decontamination factor of 10 was achieved on TURCO treated samples at 360 Bar; only 200 Bar was required to achieve the same decontamination factor on LOMI treated samples. No metal erosion of the stainless steel substrate was found to occur at these pressures. (author).

Energy Technology Data Exchange (ETDEWEB)

Orujillo, sometimes called wood matter from pressed oil-stone (WPOS) is a residue from the olive oil mill industry. The generation of this biomass residue is concentrated in small areas allowing its use as fuel for medium size gasification and combustion plants. Rates of gasification of WPOS char were measured in a TGA at various temperatures (800-850-875-900-950{sup o}C), CO{sub 2} partial pressures (0.20-0.35-0.50 bar) and CO partial pressures (0.0-0.20 bar). The experiments were carried out with a monolayer bed of very fine particles well exposed to the gas so as to minimise mass and heat transfer resistances. Two kinetic models, the nth order model and Langmuir-Hinshelwood model, have been used to fit with the reactivity data. For pure CO{sub 2} experiments the kinetic parameters of nth order model were E=133 kJ/mol and n=0.43. The Langmuir-Hinshelwood kinetic model clearly describes the observed CO inhibition effect on the CO{sub 2} ...

Energy Technology Data Exchange (ETDEWEB)

We investigate the sparticle production processes e{gamma} {yields} e tilde(Z tilde){sub 1} and {gamma}{gamma} {yields} (f tilde)(f tilde and bar) at high energy e{gamma} and {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). It will be shown that the e{gamma} colliders would be more suitable in searching for the heavy selectrons than ee colliders because of the low mass threshold of the process e{gamma} {yields} (e tilde)(Z tilde){sub 1}. We show that the standard background processes e{gamma} {yields} {nu}W and eZ can be suppressed in terms of initial beam polarization as well as the kinematical cuts on the energy and angle of the final electron. Moreover, it will be argued that the experimental measurements of the cross sections for the processes e{gamma} {yields} (e tilde)(Z tilde){sub 1} and {gamma}{gamma} {yields} (f tilde and bar)(f tilde) could enable us to constrain the basic parameters in ...

CERN Document Server

We propose the Particle Swarm Optimization (PSO) as an alternative method for locating periodic orbits in a three--dimensional (3D) model of barred galaxies. We develop an appropriate scheme that transforms the problem of finding periodic orbits into the problem of detecting global minimizers of a function, which is defined on the Poincar\\'{e} Surface of Section (PSS) of the Hamiltonian system. By combining the PSO method with deflection techniques, we succeeded in tracing systematically several periodic orbits of the system. The method succeeded in tracing the initial conditions of periodic orbits in cases where Newton iterative techniques had difficulties. In particular, we found families of 2D and 3D periodic orbits associated with the inner 8:1 to 12:1 resonances, between the radial 4:1 and corotation resonances of our 3D Ferrers bar model. The main advantages of the proposed algorithm is its simplicity, its ability to work using function ...

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The authors measure the dipion mass spectrum in X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} decays using 360 pb{sup -1} of {bar p}p collisions at {radical}s = 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity ({sup 3}S{sub 1}, {sup 1}P{sub 1}, and {sup 3}D{sub J}) charmonia decaying to J/{psi}{pi}{sup +}{pi}{sup -}, as well as event C-parity states in which the pions are from {rho}{sup 0} decay. The latter case also encompasses exotic interpretations, such as a D{sup 0}{bar D}*{sup 0} molecule. Only the {sup 3}S{sub 1} and J/{psi} {rho} hypotheses are compatible with the data. Since {sup 3}S{sub 1} is untenable on other grounds, decay via J/{psi} {rho} is favored, which implies C = +1 for the X(3872). Models for different J/{psi}-{rho} angular momenta L are considered. Flexibility in the models, especially the introduction of {rho}-{omega} interference, enable good descriptions of the data for ...

CERN Document Server

We investigate the possibility of producing the $\\omega\\phi$ threshold enhancement recently observed in the $J\\psi\\to\\gamma X(1812),~X(1812)\\to\\omega\\phi$ at BES by assuming the X(1812) to be a candidate of $(K^{*}\\bar K^{*0})$ molecular state. We evaluate the decay rate of $X(1812)\\to\\eta\\eta', \\eta\\eta, \\omega\\phi, K^+K^-, \\rho^+\\rho^-$, $\\omega\\omega, K^{*+}K^{*-}$ and $\\pi^+\\pi^-$ based on the X(1812) to be a candidate of $(\\ksks)$ molecule. It turns out the X(1812) dominantly decays into $\\eta\\eta'$ and $\\eta\\eta$. These channels are suggested to be the laboratory to test the molecular scenario in experiment. We also evaluate the branching fraction $Br(X\\to\\omega\\phi)\\simeq 4.60%$. However, the X(1812) has small branching fractions to decay into other $VV$ or $PP$ final states, from which it seems to be consistent with the experimental observation. In the molecular scenario, the X(1812) production rate is also evaluated to be ...

Energy Technology Data Exchange (ETDEWEB)

High-resolution sequence stratigraphy concepts are applied to Erema, a Miocene onshore field of the Niger delta. The field's production is decreasing and an up-to-date geological model is essential to monitor the production. We aim to show an approach, using subsurface data and sequence stratigraphic concepts, which results in a time-line (Maximum Flooding Surfaces) correlation scheme. This scheme is based upon a facies model and is destined to guide the study of the characterization of reservoir heterogeneities. Using the cored well as a reference point, the facies model consists of shoreface dunes (planar tabular cross-stratified sandstones) changing landward into fluvial distributary deposits (through cross-stratified sandstones) via a tide-influenced coastal plain facies. The stacking pattern of genetic units shows a seaward stepping phase at the reservoir scale (sixty metres thick) with an abrupt deepening at the top of the reservoir. The proposed geological scheme, at ...

CERN Document Server

The $\\bar{K}N$ system at threshold is a sensitive testing ground for low energy QCD, especially for the explicit chiral symmetry breaking. Therefore, we have measured the $K$-series x rays of kaonic hydrogen atoms at the DA$\\Phi$NE electron-positron collider of Laboratori Nazionali di Frascati, and have determined the most precise values of the strong-interaction energy-level shift and width of the $1s$ atomic state. As x-ray detectors, we used large-area silicon drift detectors having excellent energy and timing resolution, which were developed especially for the SIDDHARTA experiment. The shift and width were determined to be $\\epsilon_{1s} = -283 \\pm 36 \\pm 6 {(syst)}$ eV and $\\Gamma_{1s} = 541 \\pm 89 {(stat)} \\pm 22 {(syst)}$ eV, respectively. The new values will provide vital constraints on the theoretical description of the low-energy $\\bar{K}N$ interaction.

Energy Technology Data Exchange (ETDEWEB)

The pipelines is provided for gases, particluarly helium, at temperature of about 1000/sup 0/C (pressure about 40 bar) and is used as the connection be tween a gas cooled high temperature reactor and a heat load. The pipe consists of a temperature-resistant inner tube, which is composed of several pipe sections, which are supported on ball bearings, and a gas tight pressurised outer tube. There are supports and insulation between the two tubes. The sub-claims concern fixing of and bearings for the pipe sections. The description is very detailed and supplemented by drawings.

International Nuclear Information System (INIS)

The objective of this study is to comprehend the basic structural characteristics of box shaped mixed structures proposed for a future nuclear reactor building structure. Specimens of reinforced concrete precast panel walls of the mixed structures were prepared using ultrahigh strength materials. Two bending shear tests were conducted with a parameter of the quantity of reinforcement bars. The results include: (1) Relationship of shear stress and the angle of the structure, and (2) Failure mode. (author)

Energy Technology Data Exchange (ETDEWEB)

We present a recent study of the QCD corrections to dilepton production near partonic threshold in transversely polarized {bar p}p scattering, We analyze the role of the higher-order perturbative QCD corrections in terms of the available fixed-order contributions as well as of all-order soft-gluon resummations for the kinematical regime of proposed experiments at GSI-FAIR. We find that perturbative corrections are large for both unpolarized and polarized cross sections, but that the spin asymmetries are stable. The role of the far infrared region of the momentum integral in the resummed exponent and the effect of the NNLL resummation are briefly discussed.

Energy Technology Data Exchange (ETDEWEB)

The heavy Higgs bosons H,A of the minimal supersymmetric extension of the Standard Model can be produced as resonances in high-energy {gamma}{gamma} colliders. Prospects of the search for these particles in bb-bar and neutralino-pair final states are studied in this report. Heavy Higgs bosons can be found with masses up to about 70-80% of the initial e{sup +}e{sup -} collider energy for moderate values of tan {beta}, i.e. in areas of the parameter space not accessible at other colliders.

Energy Technology Data Exchange (ETDEWEB)

High-power diode laser arrays emitting at 690 nm have been developed for solid-state laser pumping. The laser diode bars (fill factor [approx]0.7) have been fabricated from single quantum well AlGaInP-based heterostructures. Using silicon microchannel heatsinks, a record high 360 W/cm[sup 2] per emitting aperture is achieved under continuous wave operation.

Energy Technology Data Exchange (ETDEWEB)

A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

Energy Technology Data Exchange (ETDEWEB)

The dispersion curves E(k-bar) have been calculated for bound and resonant (110) surface states of AlSb, AlAs, and AlP. AlSb is predicted to have no surface states within the bulk fundamental band gap, but AlAs and AlP are predicted to have surface state band minima which are very near the conduction band edge, and could lie either within the gap or immediately above the edge.

Energy Technology Data Exchange (ETDEWEB)

Using a model of the acidification process of rain, the authors calculate and analyze the effects and contributions of a below-cloud aerosol in its different concentrations and acidities on the pH and ion components of rain under the conditions of different concentrations of pollution gases. The results show that the aerosol has an acidification or alkalization effect on the rain which changes the pHs of rain and aerosol. As acidifying pollution gas concentrations (SO[sub 2]), HNO[sub 3] are low, the acid aerosol has important effects on the pH and H+ of rain, but as the gas concentrations are high, the acid aerosol has very little effect. The alkalizing aerosol makes the pH of rain increase by between 0.3 and 0.5 and neutralizes about 60%of H[sup +] in the rain. As alkalizing pollution gas NH[sub 3] exists, the acid aerosol has important effects on the pH and H[sup +] of rain. But the alkalizing aerosol has very little effect, especially as the NH[sub 3] ...

International Nuclear Information System (INIS)

In the present paper a procedure is proposed for the determination of traces of Cd, Co, Mn and Cr in petroleum industry produced water by inductively coupled plasma optical emission spectrometry. The procedure is based on cloud point extraction of these metals, as their dithizonate complexes, into the surfactant-rich phase of octylphenoxypolyethoxyethanol surfactant (Triton X-114). Extractions were carried out in solutions with salinities between 10 per mille and 70 per mille. Since residual salinity in the surfactant-rich phase caused differences in its transport to the plasma, yttrium was used as an internal standard to correct for this effect. The simultaneous metal extraction procedure was optimized by response surface methodology using a Doehlert design and desirability function. Enhancement factors of 21, 21, 9 and 19, along with limits of quantification of 0.093, 0.20, 0.73 and 1.2 #mu#g L"-"1, and precision expressed as relative standard deviation (n = 8, ...

International Nuclear Information System (INIS)

The formation and evolution of the circumstellar disk in unmagnetized molecular clouds is investigated using three-dimensional hydrodynamic simulations from the prestellar core until the end of the main accretion phase. In collapsing cloud cores, the first (adiabatic) core with a size of #approx#>3 AU forms prior to the formation of the protostar. At its formation, the first core has a thick disk-like structure and is mainly supported by the thermal pressure. After the protostar formation, it decreases the thickness gradually and becomes supported by the centrifugal force. We found that the first core is a precursor of the circumstellar disk with a size of >3 AU. This means that unmagnetized protoplanetary disk smaller than <3 AU does not exist. Reflecting the thermodynamics of the collapsing gas, at the protostar formation epoch, the first core (or the circumstellar disk) has a mass of #approx#0.005-0.1 M_s_u_n, while the protostar ...

Energy Technology Data Exchange (ETDEWEB)

Toxic studies were conducted with rats, mice, and guinea pigs to determine acute effects from single exposures to M60A1-tank-generated DF2 and DF1 (diesel fuel) smoke and/or exhaust clouds under static airflow conditions. Emissions were disseminated with the Vehicle Engine Exhaust Smoke System (VEESS) and exposure periods ranged from 15 to 300 minutes. At attempted airborne concentrations of 10.0 to 12.0 mg/i (10,000 cu.m to 12,000 cu.m) of the DF2 and DF1 smoke/exhaust mixtures and 0.2 mg/1 (200 mg/cu.m) of the exhausts, toxic signs (excluding death) and lung compliance changes were observed after 15-minute exposures. Death and pathological abnormalities of the lung were seen after 16-minute exposures to DF2 smoke and/or exhaust. Exposures to DF1 smoke/exhaust showed lung pathology and death by 120 minutes while death and turbinate lesions were observed in animals exposed to DF1 exhaust for 60 minutes. Experimental evidence suggests that a principal toxic ...

Energy Technology Data Exchange (ETDEWEB)

Due to the great development occurred in the world after the Second World War and the establishment of patterns of increasingly intense, the energy demand amounted to the point, putting at risk the non-renewable energy sources such as oil, coal minerals, among others, with growing interest in renewable energies, among which the biodiesel has been detached. In this sense, the present work had for objective to evaluate the fuel consumption of a tractor Valtra BM100 4x2 TDA, running with ethyl biodiesel from soybean filtered in seven mixture proportions mixed with the diesel, subject to two forces in the traction bar. The work was conducted in the Department of Rural Engineering of the Paulista State University (UNESP), Jaboticabal Campus, in an entirely randomized designed, in a factorial diagram 2 x 7, with three repetitions. The treatments were a combination for two forces in the traction bar (10 and 22 kN) and seven mixture proportions (B{sub ...

Energy Technology Data Exchange (ETDEWEB)

Cylindrical shells with regular perforation are widely used in power generating equipment and in particular in collectors 1 of the circuit of steam generators of power generating installations with water-water reactors (WWPR) The state of stress of collectors is determined by a broad spectrum of technological and operational loads, it is therefore difficult to analyze it theoretically. The aim of the present work is the experimental investigation of stresses in the cylindrical shells of collectors subjected to internal pressure, the generalization and systematization of empirical data in the form of engineering formulas and nomographs. The investigations were carried out with photoelastic three-dimensional models with the use of {open_quotes}freezing{close_quotes}. The basic characteristics of the state of stress of perforated shells (in particular those used in calculations of the strength and life of collectors) are the values of the stress intensity factor K and of the stress ...

Energy Technology Data Exchange (ETDEWEB)

Gas quenching for the hardening of steel parts is a lower-pollution alternative to quenching in quenchants such as oil or salt. As the surfaces of the cooled parts remain clean after gas quenching, there is no need to wash them after heat treatment, which reduces the consumption of oils and detergents. The fire risk and ventilation requirements of oil quenching are eliminated. In addition, some trials have shown that gas quenching has a positive effect on distortion, representing a saving in finishing work and thus a reduction in costs. Today, gas quenching is used almost solely in vacuum furnaces. Quenching is normally performed in the same chamber as heating, which means that besides quenching the batch, the quenching system must also remove heat from the heating elements and insulation of the furnace. Previous trials performed by IVF have shown that gas quenching with helium of ball bearing and carburizing steels (and other steels) in sizes up to 25 mm at pressures up to 20 ...

CERN Document Server

In this paper, we describe our vectorized and parallelized adaptive mesh refinement (AMR) N-body code with shared time steps, and report its performance on a Fujitsu VPP5000 vector-parallel supercomputer. Our AMR N-body code puts hierarchical meshes recursively where higher resolution is required and the time step of all particles are the same. The parts which are the most difficult to vectorize are loops that access the mesh data and particle data. We vectorized such parts by changing the loop structure, so that the innermost loop steps through the cells instead of the particles in each cell, in other words, by changing the loop order from the depth-first order to the breadth-first order. Mass assignment is also vectorizable using this loop order exchange and splitting the loop into $2^{N_{dim}}$ loops, if the cloud-in-cell scheme is adopted. Here, $N_{dim}$ is the number of dimension. These vectorization schemes which eliminate the unvectorized loops are ...

CERN Document Server

We study the redshift evolution of galaxy pair fractions and merger rates for different types of galaxies using kinematic pairs selected from the DEEP2 Redshift Survey. Parameterizing the evolution of the pair fraction as (1+z)^{m}, we find that the companion rate increases mildly with redshift with m = 0.41+-0.20 for all galaxies with -21 < M_B^{e} < -19. Blue galaxies show slightly faster evolution in the blue companion rate with m = 1.27+-0.35 while red galaxies have had fewer red companions in the past as evidenced by the negative slope m = -0.92+-0.59. We find that at low redshift the pair fraction within the red sequence exceeds that of the blue cloud, indicating a higher merger probability among red galaxies compared to that among the blue galaxies. With further assumptions on the merger time scale and the fraction of pairs that will merge, the galaxy major merger rates for 0.1 < z <1.2 are estimated to be ~10^{-3}h^{3}Mpc^{-3}Gyr^{-1} with a ...

Energy Technology Data Exchange (ETDEWEB)

The Argonne Boundary Layer Experiments (ABLE) facility, located in south central Kansas, east of Wichita, is devoted primarily to investigations of and within the planetary boundary layer (PBL), including the dynamics of the mixed layer during both day and night; effects of varying land use and land form; the interactive role of precipitation, runoff, and soil moisture; storm development; and energy budgets on scales of 10 to 100 km. Located entirely within the Walnut River watershed, ABLE provides intense measurements within the northeast quadrant (Fig. 1) of the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) of the Atmospheric Radiation Measurement (ARM) Program (Stokes and Schwarz, 1994). By combining the continuous measurements of ABLE with ancillary continuous measurements of, for example, the ARM and the Global Energy Water cycle Experiment (GEWEX) (Kinster and Shukla, 1990) programs, ABLE provides a platform within which shorter, more ...

CERN Document Server

We numerically investigate whether and how gaseous ejecta from AGB stars can be converted into new stars within originally massive star clusters (MSCs) in order to understand the origin of multiple stellar populations in globular clusters (GCs). We adopt a scenario in which (i) MSCs with masses of M_s can be formed from high-mass, high-density giant molecular clouds (GMCs) in their host galactic building blocks embedded in dark matter halos at high redshifts and (ii) their evolution therefore can be significantly influenced by M_s, their initial locations, and physical properties of their hosts. Our 3D hydrodynamical simulations show that gaseous ejecta from AGB stars can be retained within MSCs and consequently converted into new stars very efficiently in the central regions of MSCs, only if M_s exceed a threshold mass (M_th) of ~10^6 M_sun. The new stars can correspond to the ``second generation (SG)'' of stars with higher Na and lower O abundances observed in ...

CERN Document Server

Ultra-luminous infrared galaxies are among the most luminous objects in the local universe and are thought to be powered by intense star formation. It has been shown that in these objects the rotational spectral lines of molecular hydrogen observed at mid-infrared wavelengths are not affected by dust obscuration, leaving unresolved the source of excitation of this emission. Here I report an analysis of archival Spitzer Space Telescope data on ultra-luminous infrared galaxies and demonstrate that star formation regions are buried inside optically thick clouds of gas and dust, so that dust obscuration affects star-formation indicators but not molecular hydrogen. I thereby establish that the emission of H_2 is not co-spatial with the buried starburst activity and originates outside the obscured regions. This is rather surprising in light of the standard view that H_2 emission is directly associated with star-formation activity. Instead, I propose that H_2 emission in ...

CERN Document Server

To understand evolutionary and environmental effects during the formation of high-mass stars, we observed three regions of massive star formation at different evolutionary stages that reside in the same natal molecular cloud. Methods. The three regions S255IR, S255N and S255S were observed at 1.3 mm with the Submillimeter Array (SMA) and followup short spacing information was obtained with the IRAM 30m telescope. Near infrared (NIR) H + K-band spectra and continuum observations were taken for S255IR with VLT-SINFONI to study the different stellar populations in this region. The combination of millimeter (mm) and near infrared data allow us to characterize different stellar populations within the young forming cluster in detail. While we find multiple mm continuum sources toward all regions, their outflow, disk and chemical properties vary considerably. The most evolved source S255IR exhibits a collimated bipolar outflow visible in CO and H2 emission, the outflows ...

Energy Technology Data Exchange (ETDEWEB)

Alloy 800 has been proposed for use in the receiver tube panel arrays of advanced solar central receiver (SCR) designs. In this application the alloy will be exposed to a molten mixture of sodium and potassium nitrate salts at temperatures ranging up to approximately 600/sup 0/C While these salts are routinely used in a variety of applications including metal heat treating and process heat transfer, common industrial experience has been limited to maximum temperatures of 400/sup 0/C - 450/sup 0/C. There is, therefore, considerable interest in the compatibility of these salts with containment alloys at the higher temperatures associated with SCR designs. Additionally, the containment alloy may be subject to thermally induced fatigue damage resulting from intermittent cloud cover and diurnal cycling. Previous work has found that slower near-threshold fatigue crack growth rates (FCGR) in Alloy 800 result when it is tested in molten nitrate salt at 600/sup 0/C ...

CERN Multimedia

LECTURE SERIES 8, 9, 10 11 & 12 June 2009 11:00-12:00 - Main Auditorium, Bldg. 500 Scenarios and Technological Challenges for a LHC Luminosity Upgrade: Introduction to the LHC Upgrade Program and Summary of Physics Motivations After a general introduction to the motivations for a LHC upgrade, the lectures will discuss the beam dynamics and technological challenges of the increase of the LHC luminosity, and the possible scenarios. Items such as a stronger final focus with larger aperture magnets, crab cavities, electron cloud issues, beam-beam interaction, machine protection and collimation will be discussed.Monday 8 June 2009 Introduction to the LHC upgrade program - L. Evans Summary of Physics Motivations - M. Mangano Tuesday 9 June 2009 The Dectector Upgrade and the Requirements on the Upgrade Scenarios - M. Nessi Wednesday 10 June 2009 Scenarios for the LHC Luminosity Upgrade - F. Zimmermann Thursday 11 June 2009 Main Accelerator Science Challenges: Magnet ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this manuscript is to fully derive a geophysical multiphase model able to ''accommodate'' different multiphase turbulence approaches; viz., the Reynolds Averaged Navier-Stokes (RANS), the Large Eddy Simulation (LES), or hybrid RANSLES. This manuscript is the first part of a larger geophysical multiphase project--lead by LANL--that aims to develop comprehensive modeling tools for large-scale, atmospheric, transient-buoyancy dusty jets and plume (e.g., plinian clouds, nuclear ''mushrooms'', ''supercell'' forest fire plumes) and for boundary-dominated geophysical multiphase gravity currents (e.g., dusty surges, diluted pyroclastic flows, dusty gravity currents in street canyons). LES is a partially deterministic approach constructed on either a spatial- or a temporal-separation between the large and small scales of the flow, whereas RANS is an ...

Science.gov (United States)

According to the California Earthquake Authority, only about 12% of current California residences are covered by any form of earthquake insurance, down from about 30% in 1996 following the 1994, M6.7 Northridge earthquake. Part of the reason for this decreasing rate of insurance uptake is the high deductible, either 10% or 15% of the value of the structure, and the relatively high cost of the premiums, as much as thousands of dollars per year. The earthquake insurance industry is composed of the CEA, a public-private partnership; modeling companies that produce damage and loss models similar to the FEMA HAZUS model; and financial companies such as the insurance, reinsurance, and investment banking companies in New York, London, the Cayman Islands, Zurich, Dubai, Singapore, and elsewhere. In setting earthquake insurance rates, financial companies rely on models like HAZUS, that calculate on risk and exposure. In California, the process begins with an official earthquake forecast by the ...

Energy Technology Data Exchange (ETDEWEB)

Acceptance Testing of the WRAP 1 Plant Control System Hardware will be conducted throughout the construction of WRAP I with the final testing on the Process Area hardware being completed in November 1996. The hardware tests will be broken out by the following functional areas; Local Control Units, Operator Control Stations in the WRAP Control Room, DMS Server, PCS Server, Operator Interface Units, printers, DNS terminals, WRAP Local Area Network/Communications, and bar code equipment. This document will contain completed copies of each of the hardware tests along with the applicable test logs and completed test exception reports.

International Nuclear Information System (INIS)

A magnetic rhombohedral PrCo_2C_x (x = 0.05 #approx#0.25) phase (space group Rbar 3m), which is heavily twinned along the #left brace#110#right brace# and #left brace#211#right brace# planes, was identified. The twinning mechanism was explored by analyzing the reduction of crystal symmetry due to the cubic-rhombohedral phase transformation. The origin of the twinning and the formation of four twin variants were attributed to the insertion of carbon interstitials into Co_4 tetrahedrons along the bar 3 axis in the rhombohedral lattice, which corresponds to one of the four equivalent axes of its parent PrCo_2 cubic-lattice.

International Nuclear Information System (INIS)

A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle is within 10 ?s with the backing pressure as high as 25 bar. With a nanosecond laser pulse focused on the gas jet about 1 mm below the nozzle, the actuation time is calculated to be about 15 ms by detecting the laser produced spark radiation, which reveals the existence of the gas jet and the relative gas density evolving with time. Consequently the gas density is estimated to be well above 1019 cm-3, compared with theoretical simulations from the nozzle parameters.

Energy Technology Data Exchange (ETDEWEB)

The light curves produced by all-sky monitors, such as the Rossi X-ray Timing Explorer All-Sky Monitor and the Swift Burst Alert Telescope (BAT), generally have non-uniform error bars. In searching for periodic modulation in this type of data using power spectra it can be important to use appropriate weighting of data points to achieve the best sensitivity. It was recently demonstrated that for Swift BAT data a simple weighting scheme can actually sometimes reduce the sensitivity of the power spectrum depending on source brightness. Instead, a modified weighting scheme, based on the Cochran semi-weighted mean, gives improved results independent of source brightness. We investigate the benefits of weighting power spectra in period searches using simulated GLAST LAT observations of {gamma}-ray binaries.

International Nuclear Information System (INIS)

Several heats of Alloy 800 are included in a survey of materials being creep tested in a simulated HTR helium atmosphere in the temperature range 650 to 800degC. The results are, as yet, incomplete, but indicate wide variations in the influence of the atmosphere on creep properties. Some heats appear, from results so far available up to 10,000 hours duration, to have greater creep strength in helium than in air, but others have the strength reduced by as much as 20%. Metallographic examination of terminated creep test bars and of unstressed samples indicates that oxidation of reactive constituents takes place, forming a surface scale and sub-surface oxide penetration. Carburisation can also occur and at 750 to 800degC this can penetrate to a depth of up to 800 #mu# m after 5000 h. (author).

Energy Technology Data Exchange (ETDEWEB)

The authors search Z{prime} bosons in dielectron events produced in p{bar p} collisions at {radical}s = 1.96 TeV, using a 0.45 fb{sup -1} dataset accumulated with the CDF II detector at the Fermilab Tevatron. To identify the Z{prime} {yields} e{sup +}e{sup -} signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z{prime} mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z{prime}, as well as on the contact interaction mass scales for different helicity structure scenarios.

British Library Electronic Table of Contents (United Kingdom)

The regenerative-chatter resistance of a viscoelastic cantilever beam is analyzed and compared to the common dynamic vibration absorber (DVA) system. The beam represents a tool holder for turning operation in machining. The optimum structural parameters are found by maximizing the most negative real part of the frequency response function (FRF). The FRF is found analytically by using an appropriate Greens function. Keeping the cantilever static stiffness constant, further increase in the optimal resistance is achieved by changing the ratio between the two elastic moduli in the 3-parameter solid viscoelastic material model. Three additional chatter resistance indicators are also investigated: the most positive real part of the FRF, the magnitude of the FRF and the resonant frequency. It is ...

British Library Electronic Table of Contents (United Kingdom)

Maldives comprise some of the most characteristic and significant atoll systems, but the meiobenthic assemblages of these islands are still largely unknown. A study on meiofauna was conducted on three Maldivian sandy back-reef platforms differently exposed to stronger westerly monsoons. Clear high energy effects of the waves causing currents and erosions were observed at the completely exposed and isolated offshore reef of Thoddoo Island. Wave energy of medium intensity was confirmed at Rasdhoo by depositional structures (finolhu), while a medium to low energy level was recorded at Gulhi on the basis of the presence of a low sandy bar. The meiofaunal assemblage counted 17 major taxa. Copepods and nematodes were dominant, followed by platyhelminthes and polychaetes. The nematode assemblage ...

International Nuclear Information System (INIS)

This paper discusses the mechanisms of gas breakdown at low values of pressure and inter-electrode gap, i.e. in the vicinity of the Paschen minimum. In this area of pressure and inter-electrode gap values, breakdown occurs either through gas or vacuum mechanisms, and also the so called anomalous Paschen effect appears. Electrical breakdown of electropositive, electronegative and noble gases has been investigated theoretically, experimentally and numerically. Based on the results obtained, regions in which particular breakdown mechanisms appear have been demarcated. Special attention has been devoted to the anomalous Paschen effect as well as to the avalanche vacuum breakdown mechanism.

British Library Electronic Table of Contents (United Kingdom)

In this work, a pre-cracked semi-circular shaped explosive simulant was loaded using a split Hopkinson pressure bar (SHPB). A high-speed camera was used to capture the deformation and fracture process of the specimen in situ. The digital images were processed using the digital image correlation (DIC) method. Next, full displacement and strain fields were obtained. The displacement vector field shows that the specimen fractured under tensile stress action. The strain field can be used to predict the crack propagation. Results show that the method of combined DIC and SHPB is effective to study the dynamic deformation and fracture behavior of explosive simulants. In addition, the specimen was loaded using a drop weight. The fracture toughness of the specimen was preliminary measured.

British Library Electronic Table of Contents (United Kingdom)

Excellent mechanical properties and corrosion resistance combined with low weight qualify ?-titanium materials for lightweight applications in aviation, automotive and energy engineering. Thus far, actual applications of these materials have been limited due to high material costs and limited processing knowledge. One approach for developing resource-efficient manufacturing methods is the application of incremental forming methods. This article focuses on the development of the incremental spin extrusion process, which creates hollow profiles from solid bars. This method allows hollow shape manufacturing with a much higher flexibility than other forming methods and a significantly improved material utilization in comparison to machining methods, such as deep hole drilling. Beta-titanium al...

Energy Technology Data Exchange (ETDEWEB)

A new test methodology is described which allows access to loading rates that lie between split Hopkinson bar and shock-loading techniques. Gas gun experiments combined with velocity interferometry techniques have been used to experimentally determine the intermediate strain-rate loading behavior of Coors AD995 alumina and Cercom silicon-carbide rods. Graded-density materials have been used as impactors; thereby eliminating the tension states generated by the radial stress components during the loading phase. Results of these experiments demonstrate that the time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod. This allows access to intermediate loading rates over 5 x 10{sup 3}/s to a few times 10{sup 4}/s.

International Nuclear Information System (INIS)

This article describes the project for the installation of an additional emergency diesel generator in both Asco and Vandellos NPPs. The basic objectives of this project are to improve the availability of the emergency generation system, in order to provide greater ability to address potential contingencies, and also to increase the flexibility of the preventive periodic maintenance of the emergency diesel generators. This maintenance, that is currently a milestone of the critical path of the refueling outage, will be performed on-line. The new diesel generator will be sized to support all the loads considered in the safety case and also the consumption of its own auxiliary systems, and will be tested for operability assessment on the same periodical basis than the existing ones. The solution adopted will also permit that the N diesel generator may be connected to any bus bar class 1E in a station black-out scenario. (Author)

Energy Technology Data Exchange (ETDEWEB)

A test program was conducted under contract to Sandia National Laboratories to investigate water/steam effects on elevated temperature low cycle fatigue and creep-fatigue of Alloy 800. This report presents interpretation and analysis of the test results. Tubular specimens with water sealed inside were cycled to failure under strain control. Tests were conducted to 616K (650/sup 0/F) and 922K (1200/sup 0/F); some at 922K included tensile or compressive hold periods to simulate creep-fatigue conditions. The tubular specimens showed significantly lower lives than solid bar specimens cycled at equivalent strain ranges. Rough internal surfaces contributed to early crack initiation with these specimens. Inclusion of hold periods caused further large reductions in cycles to failure.

British Library Electronic Table of Contents (United Kingdom)

The CO2 adsorption capacity of the low-cost solid sorbents of waste tire char (TC) and chicken waste char (CW) was compared with commercial active carbon (AC) and 5?? zeolite (ZA) using thermogravimetric analysis (TG), pressurized TG, and differential scanning calorimetry (DSC). The sorbents were degassed in a TG up to 150??C to release all gases on the surface of the sample, then cooled down to the designed temperature for adsorption. TG results indicated that the CO2 adsorption capacity of TC was higher than that of CW, but lower than those of AC and ZA. The maximum adsorption rate of TC at 50??C was 0.61% min?1, lower than that of AC, but higher than that of CW, 0.44% min?1. The maximum adsorption rate of ZA at 50??C was 3.1% min?1. When the pressure was over 4?bar, the adsorption rate ...

Energy Technology Data Exchange (ETDEWEB)

Red mud is a waste generated by the aluminum industry, and its disposal is a major problem for this industry. Very rich in iron, it can be used as cheap pigment for colored concrete. The red coloration can be enhanced by calcination in the range of 600 to 800 C. Such operation also transforms the aluminum hydroxides (goethite and boehmite) and clays minerals into pozzolanic admixtures that are able to consume the calcium hydroxide produced by cement hydration. Thus, it is possible to develop a new admixture for concrete: a pozzolanic pigment. The pozzolanic properties of calcined red mud were investigated by monitoring lime consumption of different mixtures of OPC and red mud. The main products of hydration were C-S-H and mono-carboaluminate (C{sub 4}A{bar C}H{sub 11}). A uniform and durable colored concrete was obtained using white cement interground with 11% of burnt red mud.

CERN Document Server

Obtaining the set of cosmological parameters consistent with observational data is an important exercise in current cosmological research. It involves finding the global maximum of the likelihood function in the multi-dimensional parameter space. Currently sampling based methods, which are in general stochastic in nature, like Markov-Chain Monte Carlo(MCMC), are being commonly used for parameter estimation. The beauty of stochastic methods is that the computational cost grows, at the most, linearly in place of exponentially (as in grid based approaches) with the dimensionality of the search space. MCMC methods sample the full joint probability distribution (posterior) from which one and two dimensional probability distributions, best fit (average) values of parameters and then error bars can be computed. In the present work we demonstrate the application of another stochastic method, named Particle Swarm Optimization (PSO), that is widely used in the field of ...

CERN Document Server

Recent advances in our understanding of the higher-wave quarkonia have generated much interests in quarkonium physics. However most are devoted to inclusive decays and productions. Experimental data of several two-body exclusive decay channels of P-wave charmonia such as \\pi \\pi and p \\bar p are available and some have recently been re-measured by the BES collaboration. It is not clear from the outset that color octet is needed for these exclusive channels. Indeed only color singlet has been used in the past and reasonable agreement with data was found. Contrary to these old results, we provide theoretical arguments for the inclusion of color octet and perform explicit calculations to back this up.

CERN Document Server

Motivated by constraint-based CAD software, we develop the foundation for the rigidity theory of a very general model: the body-and-cad structure, composed of rigid bodies in 3D constrained by pairwise coincidence, angular and distance constraints. We identify 21 relevant geometric constraints and develop the corresponding infinitesimal rigidity theory for these structures. The classical body-and-bar rigidity model can be viewed as a body-and-cad structure that uses only one constraint from this new class. As a consequence, we identify a new, necessary, but not sufficient, counting condition for minimal rigidity of body-and-cad structures: nested sparsity. This is a slight generalization of the well-known sparsity condition of Maxwell.

British Library Electronic Table of Contents (United Kingdom)

Bacterial cellulose produced by the gram-negative bacterium Gluconacetobacter xylinum was found to be an excellent native starting material for preparing shaped ultra-lightweight cellulose aerogels. The procedure comprises thorough washing and sterilization of the aquogel, quantitative solvent exchange and subsequent drying with supercritical carbon dioxide at 40 degreeC and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg cm-3 which is comparable to the most lightweight silica aerogels and distinctly lower than all values for cellulosic aerogels obtained from plant cellulose so far. SEM, ESEM and nitrogen adsorption experiments at 77 K reveal an open-porous network structure that consists of a comparatively high percentage of large mesopores and small...