Science.gov (United States)

dust measured in the Arabian Gulf region during UAE2 and examine the hypothesis that ... [8] UAE2 took place in the southern Arabian Gulf region in August and ...

International Nuclear Information System (INIS)

Dust particles in a plasma are charged negatively and are subject to various types of forces, including a drag force by plasma particles and a force due to the collective nature of a plasma. Dust particles are found in a sheath in laboratories balanced by the gravitational force and the electric force, while dust particles in space are ubiquitous, including planetary magnetospheres and interstellar space. Because of the novel nature of a complex system involving plasma particles and dust particles in a collective way, the dusty plasma is often called a complex plasma. The complex plasma is characterized by two distinctly different scales in time and in space. The plasma with electrons, ions and neutrals is characterized by the collective motion with a fast time scale and a short ...

Energy Technology Data Exchange (ETDEWEB)

The Earth`s troposphere and hydrosphere contain abundant naturally generated dust. The ultimate source materials from which the terrestrially produced dust is generated are the various rock types exposed at the Earth`s surface. Natural dust is a composite of (1) lithic, primary mineral grains; (2) mineral grains formed by secondary chemical reactions; (3) volcanic ash and dust; (4) salts from sea sprays; (5) extra-terrestrial dust; and (6) biologic materials. In this paper the various pathways to the natural generation of dust (via the hydrologic cycle) will be discussed, and two geologically well-known natural dust sources will be described, paying particular attention to quantitative measurements of the dusts from these areas. General dust studies that provide data on possibly global background ...

Science.gov (United States)

In massive star formation (gsim 40 M sun) by core accretion, the direct stellar radiation pressure acting on the dust particles exceeds the gravitational force and interferes with mass accretion at the dust sublimation front, the first absorption site. Ram pressure generated by high accretion rates of 10-3 M sun yr-1 is thought to be required to overcome the direct stellar radiation pressure. We investigate the direct stellar irradiation on the dust sublimation front, including the inner accretion disk structure. We show that the ram pressure of the accretion disk is lower than the stellar radiation pressure at the dust sublimation front. Thus, another mechanism must overcome the direct stellar radiation pressure. We suggest that the inner hot dust-free region is optically thick, shielding the dust sublimation front from direct stellar ...

CERN Document Server

Protoplanetary disks start their lives with a dust free inner region where the temperatures are higher than the sublimation temperature of solids. As the star illuminates the innermost particles, which are immersed in gas at the sublimation edge, these particles are subject to a photophoretic force. We examine the motion of dust particles at the inner edge of protoplanetary disks due to photophoretic drag. We find that, in a laminar disk, photophoretic drag increases the size of the inner hole after accretion onto the central body has become subdued. This region within the hole becomes an optically transparent zone containing gas and large dusty particles (>>10 cm), but devoid of, or strongly depleted in, smaller dust aggregates. Photophoresis can clear the inner disk of dust out to 10 AU in less than 1 Myr. At ...

Energy Technology Data Exchange (ETDEWEB)

'Improvement in understanding of the deposition of ambient dust particles on ECAM (Environmental Continuous Air Monitor) filters, reduction of the alpha-particle interference of radon progeny and other radioactive aerosols in different particle size ranges on filters, and development of ECAM''s with increased sensitivity under dusty outdoor conditions. As of May 1, 1998 (1/2 year into the project) the research-prototype 30-cm pulsed ionization chamber (PIC) is assembled and operational with an alpha particle energy resolution of better than 45 keV for 5-MeV alpha particles. Measurements of spectral resolution for alpha particles from radon decay products have been made as a function of filter type and dust loading conditions. So far, a study of ten filter types has found that the best ...

CERN Document Server

Three dimensional rotatory modes of oscillations in a one-dimensional chain of rodlike charged particles or dust grains in a plasma are investigated. The dispersion characteristics of the modes are analyzed. The stability of different equilibrium orientations of the rods, phase transitions between the different equilibria, and a critical dependence on the relative strength of the confining potential are analyzed. The relations of these processes with liquid crystals, nanotubing, and plasma coating are discussed.

Science.gov (United States)

Large amounts of atmospheric dust are lifted from the North African deserts and are transported by the trade winds over the Caribbean region, especially during the summer months. How African dust particles influence the earth's radiative budget is not well understood because these particles are highly variable and their physical, optical, and chemical properties are poorly characterized, especially when they are atmospherically processed as are those that travel from Africa to the Caribbean region. Here we present results of aerosol measurements performed at Cape San Juan (CPR), a ground-based station located at the northeastern tip of the Caribbean island of Puerto Rico. We used a condensation particle counter to determine the particle number concentration, a sunphotometer (part of the AErosol RObotical NETwork, AERONET, aeronet.gsfc.nasa.gov) to ...

International Nuclear Information System (INIS)

An analytical electron microscope study is presented on carbonaceous material in two chondritic porous aggregates, W7029* A and W7010* A2, from the Johnson Space Center Cosmic Dust Collection. The finding of well-ordered carbon-2H (lonsdaleite) in the two aggregates suggests that a record of hydrocarbon carbonization may be preserved in these materials. This carbon is a metastable phase resulting from hydrous pyrolysis below 300-350"0C and may be a precursor to poorly graphitized carbons in primitive extra terrestrial materials. (UK).

CERN Document Server

Laboratory characterization of Interplanetary Dust Particles (IDPs) collected in the lower stratosphere represents a concrete analysis of cosmic dust properties which played a fundamental role in the origin and evolution of Solar System. The IDPs were characterized by Field Emission Scanning Electron Microscope (FESEM) analyses and by InfraRed (IR) micro-spectroscopy. We present the FESEM images of six IDPs: three smooth grains, two porous and one a compact sphere. We also show the results of micro-IR transmission measurements on four IDPs that allowed us to identify their spectral class according to the criteria defined by Sandford and Walker. Only three of the analyzed particles show IR transmission spectra with a dominant "silicate absorption feature" so that they could be assigned to the three IR spectral classes: one has been classified as "amorphous olivine", one appears to be a mixture of ...

British Library Electronic Table of Contents (United Kingdom)

Flame propagating through zirconium particle cloud in a small-scale vertical rectangle chamber was investigated experimentally. In the experiments, the zirconium quoted 99% purity was used and the diameter of particles was distributed 1?22 ?m. The zirconium dust was dispersed into the chamber by air flow and ignited by an electrode spark. A high-speed video camera was used to record the images of the propagating flame. Micro-thermocouples, schlieren optical system and microscopic lens were used to obtain temperature profiles and flame structure, respectively. Based on the experimental results, flame propagation characteristics and flame structure of zirconium particle cloud were analyzed. The propagation velocity of the flame is quite slow in the initial 14 ms and then accelerates to maxim...

Energy Technology Data Exchange (ETDEWEB)

An automated Time Resolved Aerosol Collector (TRAC) has been developed for sequential sampling of field-collected aerosols for laboratory-based Computer Controlled Scanning Electron Microscopy/Energy Dispersed X-ray (CCSEM/EDX) single particle analysis. The collector is optimized for use of grid-supported 20 nm carbon films as deposition substrates. The carbon films have low enough X-ray background to permit EDX analysis down to 0.1-0.2 ?m particles, including detection of low-Z elements: C, N, & O. The TRAC provides unattended sampling onto a set of 151 individual grids, at sequential time intervals as short as 1 min. After collection, the samples are sealed and refrigerated pending analysis. The utility of the TRAC-CCSEM/EDX approach is exemplified using the aerosol samples collected during the Texas 2000 Air Quality Studies (Aug. 15 ? Sept. 15, 2000). We are able to quantitatively follow the time evolution in the relative contribution of ...

International Nuclear Information System (INIS)

The following are reported: colorimetric determination of Ti in Cr, decontamination of metals by anodic dissolution, computer code for x-ray peak identification, gel-permeation chromatography of CoRezyn 1664 polyester resin, infrared monitoring of gases and vapors, particle size analysis of dusts, nondestructive analysis of Oralloy for removable alpha contamination, dissolution (digestion) of high-fired oxides, assay of U in a Pu-U alloy, measurement of oxide thickness on Pu metal by x-ray diffraction, analysis of precipitated Pu peroxide, differentiation of Dowex SBR and 11 resins, and determination of Pu solubility in simulated lung fluid.

International Nuclear Information System (INIS)

DF (decontamination factor) of two types of air filter was investigated against "1"9"8Au aerosol particles with AMAD (activity median aerodynamic diameter) = 1.2 #mu#m and #sigma#g (geometric standard deviation) = 2.0. One of the filters, SO filter, is HEPA (high efficiency particulate air) filter media with 46 mm#phi#, and the other is HE-40T (cellulose-glass fiber filter for dust sampling) filter media with 40 mm#phi#. DF of the SO filter was found to be over 5 x 10"4 at air flow rate of 1 l/min. And DF of HE-40 T filter was determined to be 94#+-#4 at the same airflow rate. In the multistage HE-40 T filter system, DF decreased at each succeeding stage. It was confirmed by numerical simulation that the decrease of DF was not inconsistent with the decrease of collection performance in each successive filter. It was also confirmed that DF could be predicted by the numerical simulaiton, if particle penetration function of ...

Energy Technology Data Exchange (ETDEWEB)

The contamination of environmental materials (soil and dust) by heavy elements is of concern in assessing environmental pollution. Characterization of samples is performed in order to provide information that can be used to assess the potential hazard of the material, to assess remediation strategies, and to determine the source of the heavy element-bearing material. Microbeam analysis using a scanning electron microscope (SEM) or electron microprobe on polished particle mounts allows the size, internal morphology and chemical composition to be determined on a particle-by-particle basis. Computer controlled SEM allows all factors except internal structure to be acquired in an automated fashion. The authors present examples of two studies using microbeam techniques. In the first example, they illustrate how cadmium associated with sphalerite in soils can be quantified at levels down to a few parts per million (ppm) using ...

Science.gov (United States)

... Accession Number : ADA547552. Title : Aluminum-Zinc (Al-Zn) Dust Analyses for Recycling Purposes. Descriptive Note : Technical rept. ...

CERN Document Server

Aims: I have analyzed a sample of seven nearby edge-on galaxies observed in the V and K'-band, in order to infer the properties of the dust distribution. Methods: A radiative transfer model, including scattering, have been used to decompose each image into a stellar disk, a bulge, and a dust disk. The parameters describing the distributions have been obtained through standard X^2 minimization techniques. Results: The dust disks fitted to the V-band images are consistent with previous work in literature: the radial scalelength of dust is larger than that for stars (h_d/h_s ~ 1.5); the dust disk has a smaller vertical scalelength than the stellar (z_d/z_s ~ 1/3); the dust disk is almost transparent when seen face-on (central, face-on, optical depth tau_0 =0.5-1.5). Faster radiative transfer models which neglect scattering can produce equivalent fits, with changes ...

UK PubMed Central (United Kingdom)

Possible health risks associated with occupational inhalation of mycotoxin-containing dust remain largely unknown, partly because methods for mycotoxin detection are not sensitive enough for the small...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Results are presented of analysis of the dust content of air and the resources for removing sludge at the mines of the Kuzbass during drilling of ascending shafts. A design is proposed for sludge removing devices with automatic opening and closing of the valve hinges.

Science.gov (United States)

on the picture will download the highest resolution version available. M51: The Whirlpool Galaxy in Dust and Stars Credit: Credit: N. Scoville (Caltech), T. Rector (U....

UK PubMed Central (United Kingdom)

BackgroundFew studies have yet addressed the effects of di(2-ethylhexyl) phthalate (DEHP) in house dust on human nasal mucosa.ObjectivesWe investigated...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only ~0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained ...

CERN Document Server

Particle Swarm Optimization

Energy Technology Data Exchange (ETDEWEB)

Plasma surface interactions in tokamaks are known to create significant quantities of dust, which settles onto surfaces and accumulates in the vacuum vessel. In ITER, a loss of vacuum accident may result in the release of dust which will be radioactive and/or toxic, and provides increased surface area for chemical reactions or dust explosion. A new method of analysis has been developed for modeling dust resuspension and transport in loss of vacuum accidents. The aerosol dynamic equation is solved via the user defined scalar (UDS) capability in the commercial CFD code Fluent. Fluent solves up to 50 generic transport equations for user defined scalars, and allows customization of terms in these equations through user defined functions (UDF). This allows calculation of diffusion coefficients based on local flow properties, inclusion of body forces such as gravity and thermophoresis in the convection term, ...

International Nuclear Information System (INIS)

The measurements obtained here indicate ways in which micro-Raman spectroscopy can be used to elucidate structural characteristics and distribution of carbon in meteorites and interplanetary dust particles (IDPs). Existing information about structurally significant aspects of Raman measurements of graphite is combined with structurally relevant findings from the present micro-Raman studies of carbons prepared by carbonization of polyvinylidine chloride (PVDC) at various temperatures and natural material, as well as several acid residues from the Allende and Murchison meteorites in order to establish new spectra-structure relationships. Structural features of many of the materials in this study have been measured by x ray analysis and electron microscopy: thus, their structural differences can be directly correlated with differences in the Raman spectra. The spectral parameters consequently affirmed as indicators of structure are used as a ...

Energy Technology Data Exchange (ETDEWEB)

This analysis is one of 10 reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. Inhalation Exposure Input Parameters for the Biosphere Model is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis ...

Energy Technology Data Exchange (ETDEWEB)

Controlling acid mine drainage is one of the most important challenges facing the mining industry. One of the solutions to this problem is the use of soil covers. In this poster presentation, the author described the development of a soil barrier composed of cement kiln dust and fly ash. In the study, four different cement kiln dust were associated to three different fly ash types, for a total of twelve different mix. The objective was to develop a stable environmental barrier. The origin of the cement kiln dust was described, followed by the characterization and preparation of the different mix, and the monitoring of the hydration process. The results were discussed, and indicated that a barrier composed of cement kiln dust and fly ash seemed to have great potential. The results also indicated that the fly ash improve the properties of the cement kiln dust, but that the improvement ...

Science.gov (United States)

Ever-present water vapor and dust distort or block incoming radiations. ... were among the first scientific sensors to be attached to the earliest space rockets. ...

Energy Technology Data Exchange (ETDEWEB)

Fugitive dust emissions from stockpiles in the open storage yards of industrial zones and the subsequent atmospheric dust dispersion have brought about many ecological and economical problems. This paper introduces a new approach to reduce pollutant emissions by simply changing pile configuration and without affecting the operational activity on these parks. Flow around piles of different geometries and for various wind conditions was studied using previously validated Computational Fluid Dynamic (CFD) simulations. Different pile height scenarios were investigated corresponding to a constant material volume and a fixed angle of repose under various wind magnitudes. The results obtained were integrated in order to evaluate the rate of dust emissions for the various configurations considered. It was found that, for the range of wind conditions and pile dimensions tested, an optimal geometry exists which corresponds to the ...

Science.gov (United States)

star formation. To either side of the center, a small bar of dust and gas is helping to fuel the new stars. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the...

Science.gov (United States)

star evolution, globular cluster structure and evolution, massive stars, supernova remnants, reflection nebulae, interstellar dust, structure of the ISM, ...

CERN Document Server

Particle Detection with drift Chambers

International Nuclear Information System (INIS)

Daily exposures of adult beagle dogs to inhaled radon daughters plus uranium ore dust, with and without concurrent cigarette smoking, for 2 to 5-1/2 yr have produced massive pulmonary fibrosis and severe emphysema. The cumulative exposure doses are similar to those associated with a 5-fold or greater increase in death rate of uranium miners due to chronic respiratory insufficiency, including pneumoconiosis, pulmonary fibrosis, and emphysema.

Energy Technology Data Exchange (ETDEWEB)

This book presents the papers given at a symposium on occupational safety in coal mines. Topics considered at the symposium included human factors, causes and prevention of personal injuries, remote sensing for ground control, respirable dust generation by continuous miners, accident analysis, hazard analysis of mining equipment, coal mine blasting accidents, coal mine respirable dust sampling, and noise in the mining industry.

UK PubMed Central (United Kingdom)

Eight rabbits and 24 guinea-pigs were exposed to a silica dust cloud of about 40,000 pp./ml. (0·3-3·0 μ) and killed at four-weekly intervals up to 30 weeks. The guinea-pigs showed...Full Text Available

Science.gov (United States)

A developed flue gas desulfurization and dust removal process with a cross-flow moving bed filled with activated coke (AC) was tested on a pilot scale with the gas treatment capacity of 1000 mg x h(-t). The results show that a easy-operating and stable-running pilot-scale testing equipment can be reached, and under the conditions of testing space velocity, the feed gas temperature of 120 degrees C, SO2 concentrations of 3232-6006 mg x m(-3) and dust concentration of 89.3-1599.7 mg x m(-3), the high efficiency of flue gas desulfurization and dust removal is reached with the purity of dust less than 50 mg x m(-3). In the technology, the spent AC was regenerated by heating, and the SO2 concentration in the desorption gas is about 40.1%, which can be efficiently recovered as a sulfur resource. Favorable economy benefit can be reached by using the process. PMID:16850821

Energy Technology Data Exchange (ETDEWEB)

Metal dusting corrosion has been a serious problem in the petroleum and petrochemical industries, such as reforming and syngas production systems. This form of deterioration has led to worldwide material loss for 50 years. For the past three years, we have studied the mechanism of metal dusting for Fe- and Ni-base alloys. In this report, we present a correlation between the weight loss and depth of pits that form in Ni-base alloys. Nickel-base alloys were also tested at 1 and 14.8 atm (210 psi), in a high carbon activity environment. Higher system pressure was found to accelerate corrosion in most Ni-base alloys. To reduce testing time, a pre-pitting method was developed. Mechanical scratches on the alloy surface led to fast metal dusting corrosion. We have also developed preliminary data on the performance of weldments of several Ni-base alloys in a metal dusting environment. Finally, Alloy 800 tubes ...

Energy Technology Data Exchange (ETDEWEB)

Studies technological safety of installing a water spray pressure vessel between electrostatic dedusters and coal sludge ducts. These sprays are in use elsewhere for steam generator ash removal. Dust ignition and explosion tests were carried out to examine flame and pressure wave propagation through the vessel into ducts. Water jet diameter, amount of water sprayed and coal dust removed were varied. Pressure waves exceeded 250 Pa. Test results show the vessel to be suitable for installation in briquetting plants due to its flame and explosion barrier effect and extermination of smoldering dust fires. The only disadvantage of the vessel is seen as its water and electric power consumption; about 8/sup 3//h of water and 1.5 kW/h of power per vessel serving dedusters of a 2,200 m/sup 2/ rotary brown coal dryer.

Energy Technology Data Exchange (ETDEWEB)

Welded Ni-base alloys and Alloy 800 were exposed under metal dusting conditions at 600 C and 650 C for up to 6000 hours. Alloy 800 was attacked very strongly already in the first days and Alloy 600 also rather soon and widespread, on both materials attack started mainly in the heat affected zone. Several surface states of Alloy 600: brushed, ground, sand-blasted and pickled were tried only grinding caused a modest delay and decrease of metal dusting attack. Generally the attack was less widespread but deeper at 650 C than at 600 C, also for Alloy 601 and 602. The latter alloys show minor, mainly local attack, but especially the welds are affected. TIG welding led to better resistance than hand-welding. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

Energy Technology Data Exchange (ETDEWEB)

Georg Fischer GmbH operates a melting plant with several cupola furnaces in Mettmann. The plant supplies two casting plants for production of castings from nodular cast iron or malleable cast iron. It is now planned to convert one of the existing hot-blast cupola furnaces to the latest state of the art. Under special consideration are clear reduction of dust emission by use of a filtering separator below the permissible mass concentration according to the Clean Air Regulations; reduction of the current level of dumped waste by application of a new dust (residue) utilisation method; improvement of the total thermal efficiency of the cupola furnace melting plant by extensive, advanced utilisation of waste heat; and use of low-cost dust-like alternative fuels. (author).

CERN Document Server

We obtain an elegant and useful description of the dynamics of Szekeres dust models (in their full generality) by means of "quasi--local" scalar variables constructed by suitable integral distributions that can be interpreted as weighed proper volume averages of the local covariant scalars. In terms of these variables, the field equations and basic physical and geometric quantities are formally identical to their corresponding expressions in the spherically symmetric LTB dust models. Since we can map every Szekeres model to a unique LTB model, rigorous results valid for the latter models can be readily generalized to a non--spherical Szekeres geometry. The new variables lead naturally to an initial value formulation in which all scalars are expressed as scaling laws in terms of their values at an arbitrary initial space slice. These variables also yield a significant simplification of numerical work, since the fluid flow evolution equations ...

Energy Technology Data Exchange (ETDEWEB)

Information is provided about standardization and unification of rules for manufacturing normal electrical equipment designed for operating in underground shafts when there is no danger of explosion of gas, dust or steam. An analysis is made of the requirements included in the CEMA standard and in the state standard.

CERN Document Server

We have examined the dust photoelectric heating in the intergalactic medium (IGM). The heating rate in a typical radiation field of the IGM is represented by $\\Gamma_{\\rm pe} = 1.2\\times10^{-34}$ erg s$^{-1}$ cm$^{-3}$ $({\\cal D}/10^{-4})(n_{\\rm H}/10^{-5} {\\rm cm^{-3}})^{4/3} (J_{\\rm L}/10^{-21} {\\rm erg s^{-1} cm^{-2} Hz^{-1} sr^{-1}})^{2/3} (T/10^4 {\\rm K})^{-1/6}$, where ${\\cal D}$ is the dust-to-gas mass ratio, $n_{\\rm H}$ is the hydrogen number density, $J_{\\rm L}$ is the mean intensity at the hydrogen Lyman limit of the background radiation, and $T$ is the gas temperature, if we assume the new X-ray photoelectric yield model by Weingartner et al. (2006) and the dust size distribution in the Milky Way by Mathis, Rumpl, & Nordsieck (1977). This heating rate dominates the HI and HeII photoionization heating rates when the hydrogen number density is less than $\\sim10^{-6}$ cm$^{-3}$ if ${\\cal ...

UK PubMed Central (United Kingdom)

Workers from cotton mills were exposed to cotton dust during carding in an experimental cardroom. Cotton from different geographical locations with varying amounts of endotoxin were used. Exposure levels...Full Text Available

UK PubMed Central (United Kingdom)

OBJECTIVE: To study cause specific mortality and cancer morbidity in workers exposed to the dust of grinding materials, grinding agents, and stainless steel, especially with regard to a possibly increased...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Pressurized fluidized bed combustion (PFBC) is an emerging coal-fired, combined-cycle power generation technology nearing commercial status through several operating and planned demonstration plants throughout the world. Current-generation PFBC plants use ``ruggedized`` gas turbines that can tolerate dust loading common with conventional cyclone gas cleaning. The next generation of PFBC will apply advanced hot gas cleaning systems that will reuse the dust loading to low levels acceptable to high performance, industrial gas turbines. These advances should result in performance and cost advantages. This article examines the demonstration of PFBC technology at Tidd power station.

Energy Technology Data Exchange (ETDEWEB)

This work deals with kinetic description of carbothermic reduction of iron oxides using microwaves as power source. Previous researches show that it is possible to conduct this kind of process successfully, but real kinetic comparisons between conventional and microwaves procedure have been presented partially. The aim of this work is to describe reduction kinetics, taking into account how the iron oxide is reduced by microwaves compared with conventional energy supply. In this study the authors used iron ore in pellet shape and dust. They found that both, pellet and dust reduction stops when it reaches approximately 40%, even at whole power.

Energy Technology Data Exchange (ETDEWEB)

We present the first 3.8 {micro}m image of the dusty ring surrounding the young binary system GG Tau, obtained with the W. M. Keck II 10m telescope's adaptive optics system. THis is the longest wavelength at which the ring has been detected in scattered light so far, allowing a multi-wavelength analysis of the scattering proiperties of the dust grains present in this protoplanetary disk in combination with previous, shorter wavelengths, HST images. We find that the scattering phase function of the dust grains in the disk is only weakly dependent on the wavelength. This is inconsistent with dust models inferred from observations of the interstellar medium or dense molecular clouds. In particular, the strongly forward-throwing scattering phase function observed at 3.8 {micro}m implies a significant increase in the population of large ({approx}> 1 {micro}m) grains, which provides direct evidence for grain ...

International Nuclear Information System (INIS)

Wind tunnel tests were performed of three fugitive dust control agents derived from potato and sugar beet products. These materials are being considered for use as dust suppressants to reduce the potential for transport of radioactive materials by wind from radioactive waste construction and remediation sites. Soil and dust control agent type, solution concentrations, application quantities, aging (or drying) conditions, surface disturbance, and wind and saltating sand eolian erosive stresses were selected and controlled to simulate application and exposure of excavated soil surfaces in the field. A description of the tests, results, conclusions, and recommendations are presented in this report. The results of this study indicate that all three dust control agents can protect exposed soil surfaces from extreme eolian stresses. It is also clear that the interaction and performance of each agent with ...

Science.gov (United States)

A particle detector is provided, the particle detector including a spherical Cherenkov detector, and

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Activities of the Referenzlaboratorium Reinhaltung der Luft at Magdeburg as well as existing air pollution standards in the German Democratic Republic are reviewed. The laboratroy coordinates research and standardization in the field of industrial air pollution for the Ministry of Health. The standards provide orientation for emission control by state district health inspectorates. Emission limits (in g/m/sup 3/) which are international standards for 15 selected industries are listed. Emission limits (in g/m/sup 3/) of GDR standards, issued between 1971 and 1984 are also provided. They concern emission of brown coal dust from coal preparation plants, dust and chemical compound emission from metallurgical plants, dust emission from plants of the limestone and cement industry as well as from cupola furnace plants, boiler plants, plants of the wood industry and road asphalt mixing. Six additional standards which entered effect ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The objectives of this project were to develop technologies to manufacture self-reducing briquettes out of waste iron oxides and to recycle them in an electric arc furnace or a cupola furnace. CRM has investigated and determined the optimal characteristics (binder, size, grain size, compositions and activator for the reduction reaction) for briquettes containing mixtures of mill scales, mill sludges, electric arc furnace (EAF) dust and coal as reduction agent. The goal of obtaining briquettes, in which iron oxides are totally reduced when these briquettes are loaded with the scrap into an electric arc furnace, was achieved. Trials at ProfilARBED have shown that it is possible to recycle mill and EAF by-products conditioned in self-reducing briquettes in an electric arc furnace without influence on the performance and on the environment. The iron content of the slag does not increase as the iron of the by-product is almost completely reduced. Zinc is completely ...

International Nuclear Information System (INIS)

We present ultraviolet through far-infrared (FIR) surface brightness profiles for the 75 galaxies in the Spitzer Infrared Nearby Galaxies Survey (SINGS). The imagery used to measure the profiles includes Galaxy Evolution Explorer UV data, optical images from Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and Sloan Digital Sky Survey, near-IR data from Two Micron All Sky Survey, and mid- and FIR images from Spitzer. Along with the radial profiles, we also provide multi-wavelength asymptotic magnitudes and several nonparametric indicators of galaxy morphology: the concentration index (C 42), the asymmetry (A), the Gini coefficient (G), and the normalized second-order moment of the brightest 20% of the galaxy's flux (M-bar20). In this paper, the first of a series, we describe the technical aspects regarding the surface photometry, and present a basic analysis of the global and structural properties of the SINGS galaxies at different wavelengths. The homogeneity ...

International Nuclear Information System (INIS)

The document presents an overview on atmospheric pollution in Lebanon, with an analysis of sources of pollution, their impact on local and global environment and their control.Local causes of pollution are mainly: -Thermal power plants of electric power production which produce 75% SO_2 emission and 60% dust - Industries, especially cement industry - Land transportation which produces 70% NOX emission and 50% CO_2 A description of air pollution caused by these three sectors is revealed. Pollutants derived from fuel combustion are analyzed. It is estimated that in 2010, Co_2 emission will reach 5204450 tons, SO_2 emission will be 136470 tons, NOX emissions 96870 and dust estimated to 4130 tons. CFC consumption and measures of control according to Montreal Protocol are described. Recommendations for control of air pollution in Lebanon within a national policy are presented.

International Nuclear Information System (INIS)

Short communication.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.

Science.gov (United States)

... THESIS PARTICLE-SIZING SYSTEM FOR SCANNING ELECTRON MICROSCOPE IMAGES OF SOLID-PROPELLANT COMBUSTION EXHAUST ...

Energy Technology Data Exchange (ETDEWEB)

The nuclear interaction probability of light charged particles in BaF[sub 2] crystals has been studied as a function of the incident particle energy. Light charged particles were identified in charge and mass by measuring their magnetic rigidity and their time-of-flight. The percentage of particles undergoing nuclear interactions has been measured for particles of charge from Z=1 to Z=6 and the experimental data are compared with the results of a model calculation. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The pyrometallurgic method consisting in introduction of refining agent into the liquid cadmium has been presented. The refining agent consisting of silicon nitride, carbon dust and sodium hydroxide has been added in several portion into the liquid cadmium. Iron has been removed from the cadmium surface in the form of floating slag.

Science.gov (United States)

Exposure to crystalline silica dust causes multiple diseases, but silicosis and silica dust-associated tuberculosis (TB), in particular, are the two diseases that remain high on the list of occupational health priorities in low-income countries and that still occur in some high-income countries. The prevalence of silica-related TB is exacerbated by the human immunodeficiency virus (HIV) epidemic in low-income countries. This review describes the morphology of silica and the variable potency of the different forms. Sources of crystalline silica are discussed, with emphasis on less commonly recognised sources, such as small-scale mining operations and agriculture. Trends in the prevalence of silicosis are also presented. Although efforts have been made for many years in most countries to reduce silica dust levels, silicosis continues to occur even in young people. The clinical and pathological features and diagnosis of ...

Energy Technology Data Exchange (ETDEWEB)

A monitoring campaign of polychlorinated dibenzo-p-dioxins and dibenzofurans, polyaromatic hydrocarbons (PAHs), and polychlorinated biphenyl was carried out in an Italian iron ore sintering plant by sampling the combustion gases at the electrostatic precipitator (ESP) outlet, at the Wetfine scrubber (WS) outlet, and by collecting the ESP dust. Few data are available on these micropollutants produced in iron ore sintering plants, particularly from Italian plants. This study investigates the PAH emission profiles and the removal efficiency of ESPs and WS. PAHs were determined at the stack, ESP outlet flue gases, and in ESP dust to characterize the emission profiles and the performance of the ESP and the WS for reducing PAH emission. The 11 PAHs monitored are listed in the Italian legislative decree 152/2006. The mean total PAH sum concentration in the stack flue gases is 3.96 {mu}g/N m{sup 3}, in ESP outlet flue gases is 9.73 {mu}g/N m{sup 3}, ...

Science.gov (United States)

A method is described to smear extremely thin layers of nuclear emulsion on labeled electron microscope preparations and to measure the thicknesses of these layers, Without further separation, preparation and emulsion can be observed after exposure and development in an electron microscope. The source of the tracks formed in the emulsion can be exactly identified and the size and structure determined. This method finds applications in dust research and also in the analysis of medical and biological sections. Further information can be obtained about properties of different emulsions. (auth)

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)

Biomass combustion is an important part in a sustainable energy system, but as well a source of submicron (particles < 1 #mu#m) particles in the air. Consequently, to obtain a good air quality together with increased biomass combustion there is a need for a better understanding of particle formation. This work is a part of a larger project about formation and emissions of particles from biofuel combustion. The report includes the work performed in the project during the year 2004. The aim of the project is to describe the release of inorganic components, which cause particle emissions, during combustion of single fuel particles of biofuel, e.g. wood pellets. The work is carried out by emission measurements, systematic combustion experiments and modelling work. The results are expected to contribute to the understanding of which parameters that influence the ...

Energy Technology Data Exchange (ETDEWEB)

A composition of matter to treat particles entrained in flue gas, is described comprising: a caustic liquid used to adjust resistivity of the entrained particles; and inert particulate matter supporting the caustic liquid for inhibiting chemical action of the caustic liquid until used to adjust the resistivity of the entrained particles, the inert particulate matter supporting sufficient caustic liquid to adjust the resistivity of the entrained particles.

Energy Technology Data Exchange (ETDEWEB)

A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

CERN Multimedia

"American dominance in the study and development of high-energy particle physics may be seriously compromised, according to a report issued by the National Academy of Sciences, unless efforts are made to ensure that the next high-energy particle accelerator - the International Linear Collider (ILC) - will be constructed in the U.S.

CERN Document Server

We calculate the Bogolubov coefficients for a metric which describes the snapping of a cosmic string. If we insist on a matching condition for all times {\\it and} a particle interpretation, we find no particle creation.

UK PubMed Central (United Kingdom)

The authors' laboratory, using histochemicalmethods, previously identified two types of cholesterol-containing lipid particles in the extracellular spaces of human atherosclerotic lesions, one particle...Full Text Available

International Nuclear Information System (INIS)

The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU's evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky trademark pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of ...

Energy Technology Data Exchange (ETDEWEB)

The paper evaluates standardization of regulations on safety of electrical equipment for underground coal mines in the USSR. Factors increasing hazards of electrical failures of equipment in underground coal mines are analyzed: reduced lighting, increased humidity and dusts, damage caused by falling rocks or damage during haulage in underground workings, installation of electrical equipment in places easily accessible to untrained personnel. Standards on safety of electrical equipment for underground coal mining valid in the USSR are reviewed: the PIRNEh regulations on production of electrical equipment for coal mines developed by the VNIIVEh Institute, and the GOST national standards. International cooperation within the COMECON on safety of mining electrical equipment (the Interelectro Committee of the COMECON) is described. Certification of electrical equipment for coal mines is discussed on the example of electrical insulation types used in underground coal ...

Energy Technology Data Exchange (ETDEWEB)

Investigations are discussed carried out in a pilot plant at the Kaz. Power Engineering Scientific Research Institute into the effect of the amount of primary air in coal-dust flame on the final concentration of nitrogen oxides in flue gases. The tests were carried out in a 7500 mm high, 1600 mm dia vertical cylindrical combustion chamber having type P-57 burner, and air dispersed fuel plus additional air supplies located at the top. Amounts of coal dust fed by a drum feeder along the air pipe varied from 100-600 kg/h. The required air was supplied by 5000 m/sup 3//h Type TK-700/5 blowers at 0.04 MPa. Ehkibastuz coal samples contained: 1.3% moisture; 48.1% ash; 38.02% carbon; 2.56% hydrogen; 0.73% sulfur; 0.60% nitrogen; heat of combustion was 14.3 MJ/kg. Results obtained indicate that variations in the amount of primary air in swirl flow burners affect formation of fuel nitrogen; there is an optimum volume at which minimum quantities of ...

Energy Technology Data Exchange (ETDEWEB)

This paper evaluates abrasive jet wear tests, carried out on the ZUK-3M abrasion apparatus according to the GOSF 23.201-78 industrial standard. As abrasive material, brown coal coke dust, brown coal dust, power plant fly ash and quartz sand (for the purpose of comparison) were employed. Seventeen types of materials were blasted with abrasive jets, including a selection of steels, glass, rubber, SYS-pur plastics, cast basalt, Kawenit and vitroceramics. The test apparatus produced abrasive jet velocities between 12 and 130 ms/SUP/-/SUP/1 at rotor revolutions of 1,000 to 10,000 min/SUP/-/SUP/1. Blasted material samples were arranged at angles between 15 and 90 degrees. Various tables and graphs present abrasivity results. These results were employed for technical modifications of dedusting equipment in briquetting and coking plants, which led to a threefold increase in service life of abrasion endangered equipment parts. (8 refs.) (In German)

Energy Technology Data Exchange (ETDEWEB)

Ferrography is a technique for isolating wear particle debris from lubricating and hydraulic oils, the presence of which carry with them a history of the wear processes in the machine. Thus, the technique has fundamental applications in machine condition monitoring and failure prevention. The wear particles are significant in the metal types that are present in the particle distribution as an indication of the wearing machine components and in the particle size distribution and morphology which indicates the severity of wear in the system. In this paper, the fundamental principles which describe the working of the ferrograph, concentrating on the working of the on-line ferrograph are discussed. The significance of equilibrium particle concentration in the oil system and its measurement using the ferrograph are also discussed.

Energy Technology Data Exchange (ETDEWEB)

Twenty years after its building, the tertiary sector of La Defense district near Paris has been rehabilitated. The main reason is not only the age and wear of materials but the heating costs, the fire protection regulations, the search for a better air quality and air renewing with less dusts, smells and noise and a controlled moisture. This paper describes first the original installation of the Monge CB 6 office building and then the renovated installation: the central hot and cold air-treatment plant, the variable flow ventilation system, the air extraction and supply system threw the roofs and the pressure and thermal regulation of the installation. (J.S.)

Energy Technology Data Exchange (ETDEWEB)

Drying fine coal by microwaves is now being considered as a viable option by some coal producers. The interest in microwaves is due to problems encountered with current thermal or hot-air drying methods. The technical feasibility of drying minus 5mm coal fines by microwaves was demonstrated using pilot-scale continuous processing system. Results showed that water absorbs microwave energy significantly; but coal does not. Secondly, microwave energy heats only the water, unlike existing drying methods, which heat both water and coal. Finally, the method was found to be energy efficient and minimised the generation of dust.

Energy Technology Data Exchange (ETDEWEB)

Low-dust flue gases can be washed efficiently of SO/sub 2/, and the flue gas heat can be utilized. The residual heat fraction still required by the process is characterized by a temperature of 15/sup 0/K above the temperature of the purified flue gas. Marketable crystalline ammonium sulfate is produced. The high efficiency and low heat consumption are achieved by combining all process stages in a single, fully integrated cycle process free of heat and materials losses. The process is characterized by high efficiency, low investment and operating costs, recovery of thermal energy, and production of an ammonium sulfate fertilizer.

International Nuclear Information System (INIS)

Recycling of used battery for recovering lead done by either small household/small scale industries has been identified as a source of air pollution, especially by heavy metal (Pb). This condition give an adverse impact toward workers and societies. Technological aspect is one of the causal. The process apply an open system. Therefore, a lot of energy, as well as dust wasted to the air without prior treatment. For overcoming this condition, closed system by utilizing Cupola furnace will be offered as one of the alternatives clean technology application and to increase the recovering performance in order to set an effective and efficient result. (author)

Energy Technology Data Exchange (ETDEWEB)

An aspiration cover is proposed for the site of loading a belt conveyer including a housing arranged above the belt conveyer in whose cover there is an aspiration sleeve and a discharge chute from the upper wall and a guide having a cushioning plate on the lower end. It is distinguished by the fact that in order to improve the effectiveness of removing dust by decreasing the volume of aspirated air, the cover between the aspiration sleeve and the upper wall of the loading chute is convex in the inside of the housing and has a smooth connection to the upper wall of the discharge chute turned towards the cushioning plate.

International Nuclear Information System (INIS)

... alpha particles beta particles gamma radiation lead hot cells bricks shielding

Science.gov (United States)

... Zou, S. and RA Dalrymple, ``Coastal Sediment Transport Simulation by Smoothed Particle Hydrodynamics,'' Journal of Waterways, Ports, Coastal ...

Energy Technology Data Exchange (ETDEWEB)

A characterization study was performed on monosodium titanate (MST) particles to determine the effect of high shear forces expected from the In-Tank Precipitation (ITP) process pumps on the particle size distribution. The particles were characterized using particle size analysis and scanning electron microscopy (SEM). No significant changes in particle size distributions were observed between as-received MST and after 2--4 hours of shearing. Both as-received and sheared MST particles contained a large percentage of porosity with pore sizes on the order of 500 to 2,000 Angstroms. Because of the large percentage of porosity, the overall surface area of the MST is dominated by the internal surfaces. The uranium and plutonium species present in the waste solution will have access to both interior and exterior surfaces. Therefore, uranium and plutonium loading should ...

CERN Multimedia

"Physics in the United States is in a crisis that the country may lose the leadership in basic particle research in coming years, a report of the National Research Council warned." (1 page)

Energy Technology Data Exchange (ETDEWEB)

The possibilities for heat recovery in a cast iron melting furnace were studied. A cupola furnace which produces 40 tonnes steel per hour, produces 25,000 Nm/sup 3//h of flue gases which contain 16-22% CO. Taking into account the heat losses at the chimney where fumes are cooled to 200/sup 0/C the recoverable heat is about 12.4-10/sup 6/ kcal/h which mainly consists of combustion heat in CO. This study showed that the heat can be used for the production of electricity, which will be used in the plant. Recovery of 87 kWh of electricity per tonne of steel produced is possible. A steam turbine driven generator of 3.5 MW will be required. The combustion of the low calorific gas (approximately 400 kcal/Nm/sup 3/) has been studied and gave positive results: wet CO gas can be burnt without addition of methane and preheating of air is not required. The pilot plant consisting of a thermic system (combustion chamber and equipment to produce and condense steam without turbine and generator) was ...

Energy Technology Data Exchange (ETDEWEB)

A technique has been developed for high resolution alpha particle spectroscopy from track length determination in CR-39 plastic. On individual tracks an energy resolution deltaE close to the range straggling limit is obtainable. For 6 MeV alpha-particle deltaE is proportional 35 keV on individual particles and for groups of particles deltaE proportional 20 keV can be achieved using certain data selection criteria. At 100 keV on individual particles deltaE is proportional 20 keV. The analysis requires 1) a knowledge of the track-etch rate (Vsub(T))-range relationship and 2) a theoretical understanding of alpha-particle track structure in CR-39 as a function of particle energy, dip angle and degree of etching. The structure of alpha-particle etched tracks in CR-39 is described and two methods of analysis discussed. ...

International Nuclear Information System (INIS)

The possible role of space-like objects in elementary particle physics (and in quantum mechanics) is reviewed and discussed, mainly by exploiting the explicit consequences of the peculiar relativistic mechanics of Tachyons. Particular attention is paid: (i) to tachyons as the possible carriers of interactions; (ii) to the possibility of ''vacuum decays'' at the classical level; (iii) to a Lorentz-invariant bootstrap model; (iv) to the apparent shape of the tachyonic elementary particles and its possible connection with the de Broglie wave-particle dualism. (author).

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Random motion of a particle, emitting and absorbing tachyons, is investigated. It is shown that if bradyon is in equilibrium with neutral gas, i.e. it absorbs and emits tachyons, which do not have any charges, tha particle with each absorption-emittance of a tachyon changes its energy and momentum, never varying its own mass, and as a result it moves like a brownian particle. Thus, bradyon, interacting with tachyon gas, increases its momentum continuously in agreement with the Einstein-Fokker-Planck type equation.

Energy Technology Data Exchange (ETDEWEB)

Short communication.

CERN Document Server

The periodic mode is analyzed together with two conventional boundary handling modes for particle swarm. By providing an infinite space that comprises periodic copies of original search space, it avoids possible disorganizing of particle swarm that is induced by the undesired mutations at the boundary. The results on benchmark functions show that particle swarm with periodic mode is capable of improving the search performance significantly, by compared with that of conventional modes and other algorithms.

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

Short communication.

Energy Technology Data Exchange (ETDEWEB)

We prove a theorem stating that a massive Majorana particle (a CPT-self-conjugate particle) with arbitrary spin J can possess only an anapole moment and multipoles of that. We also show that massless Majorana particles, except those of spin (1/2, do not have any single-photon electromagnetic form factor.

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

One of several methods to build YSZ electrolyte of SOFC is plasma spraying. This system heats particle to a melting point and then pushing them into target and forming a deposition. This paper presents heating studies of YSZ particle in plasma jet. By simple model it is shown that the required time such those YSZ particle with grain size of 50 ?m to be melt is around 12 x 10-4 second. (author)

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Current applications of ..cap alpha..-particle spectrometry in post-irradiation research and reprocessing are reviewed. Implementation of procedures and techniques described in the literature to the particular samples at S.C.K./C.E.N. often results in a combined radiochemical method where ..cap alpha..-particle spectrometry is used to complement or enforce results obtained by other methods. Typical cases are reported and results obtained by different methods are compared to the results obtained by ..cap alpha..-particle spectrometry.

Energy Technology Data Exchange (ETDEWEB)

In this article a production method of a magnetorheological suspension composed with silicon steel particles of size 0.1-0.15 mm and 4% silicon content is described. Steel particles were dispersed in a conducting carrier of a by mixture of graphite particles with size 2-5 {mu}m and cedar wood oil. The filling factor of the suspension with the silicon steel particles and with graphite particles amounted to 0.25-0.40. Samples of this suspension were placed in a rectangular vessel with electrodes and used for the investigation of the Hall effect in magnetic field with induction 0-8 T, generated by Bitter-type magnet. A non-linear dependence of Hall voltage on the induction of the applied magnetic field and a hysteresis loop of this voltage in the shape of inclined digit eight were found. The causes of the observed effects is the ordering of silicon steel particles ...

International Nuclear Information System (INIS)

This paper describes the study of particles' dispersion in an isotropic turbulent flow. The particle's motion and the turbulent flow characteristics are calculated independently. While the particles' displacement is computed by the author's code, the flow is simulated with a commercial code : PowerFLOW. The particles and the flow are coupled through the relative velocity component of the aerodynamic force. When the simulated flow is turbulent, a turbulence regeneration model is used in order to get the flow instantaneous velocity. Validation of the method is done by comparing the particles' dispersion obtained with experimental results from literature and with the results calculated by FLUENT. Good accordance is found between numerical studies and experimental results. However, comparison between results of PowerFLOW coupled to the author's code and results from FLUENT shows ...

Science.gov (United States)

A possible receiver configuration is a cavity in which a falling sheet of solid particles is directly irradiated by the concentrated solar flux passing through the aperture. Regardless of the particular geometry, the radiative transfer within the falling particle curtain must be studied in order to determine the net radiative heating rate for the particles. A discrete ordinate radiative transfer model has been developed to predict the radiative coupling within the falling particle curtain. The model determines how much energy is absorbed by the particles, how much is transmitted to the rear wall of the receiver, and determines the effects of particle scattering and thermal emission on the net radiation absorbed by the particles. The model accounts for the directional nature of the radiation field, particle scattering, ...

Energy Technology Data Exchange (ETDEWEB)

A flow field and particle trajectory in a HDD (Hard Disk Drive) between two rotating disks in axisymmetric enclosures is investigated using CFD code FLUENT/UNS. The RNG k-{epsilon} model is used as a turbulent model. In this study, the flow field between two disks are symmetric, and the flow field near the enclosure is very complex. Cross stream vectors are shown both for blowing and no blowing from the hub. The larger a particle, the more fast the particle deposits at the walls. In the case of blowing from the hub, the more fast the particle deposits at the walls. (author). 9 refs., 12 figs., 1 tab.

International Nuclear Information System (INIS)

Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.

Energy Technology Data Exchange (ETDEWEB)

This standard describes the procedure and equipment for in-place testing of HEPA filter systems by the single-particle, particle-size (SPPS) spectrometer method. This method provides the capability for evaluating the effectiveness (i.e., decontamination factor or DF) of systems consisting of one or more stages of HEPA filters against submicrometer aerosols in discrete particle-size ranges. It is particularly useful for testing of multi-stage HEPA filter installations and for testing of very large (50,000 cfm installed capacity) single-stage systems where it is desired to minimize the quantity of challenge aerosol required.

International Nuclear Information System (INIS)

In the case of inelastic scattering of alpha particles to the 3"+ state, the averaged angular distributions show a characteristic shape, corresponding to the excitation of such an unnatural parity state by alpha particles in the compound nucleus process. The modified Hauser-Feshbach cross-section calculations give a good description of the averaged distributions for the alpha particle scattering to the 3"+ state and the compound nucleus parameters could be extracted. The calculations of the compounds nucleus contributions to the other states in the case of 24 MeV alpha particle scattering from "2"8Si show that this contribution is not negligible and in the case of the scattering to the 4"+ state seems to be dominant. (Z.M.).

CERN Document Server

There are several approaches to describe flows with particles e.g. Lattice-Gas Automata (LGA), Lattice-Boltzmann method (LBM) or smoothed particle hydrodynamics (SPH). These approaches do not use fixed grids on which the Navier-Stokes equations are solved via e.g. finite volume method. The flow is simulated using a multitude of particles or particle density distributions, which interacts and due to statistical laws and an even more fundamental approach than the Navier-Stokes equation, the averaged flow variables can be derived. After a short summary of the most popular particle methods the new DMPC (Dissipative Multiple Particles Collision) approach will be presented. The DMPC-model eliminates some of the weak points of the established particle methods and shows high potential for more accurate CFD solution especially in areas where standard ...

Energy Technology Data Exchange (ETDEWEB)

Particle shape is an important parameter in numerous civil, environmental, and petroleum engineering applications. In ground-water flow, the shape of individual particles comprising the soil affects the soil`s pore size distribution and, hence, the important flow characteristics such as hydraulic conductivity and headloss. A model for delineating the relative importance of particle size, particle shape, and porosity, (and their interactions), in explaining the variability of hydraulic conductivity of a granular porous medium is developed and tested. Three types of porous media are considered in this work: spherical glass beads; granular sand; and irregularly shaped, shredded glass particles. A reliable method for quantifying the three-dimensional shape and packing of large samples of irregular particles based on their angle of repose is presented. The results of ...

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the application of a Computational Fluid Dynamics (CFD) code (FLUENT) to predict temperature and velocity profiles, and particle trajectories in an industrial fired by a low NO{sub x} pulverized coal swirl burner. The predictions of the code were compared to experimental measurements of gas temperature, particle size distribution, and particle velocities. The diagnostics employed were a suction pyrometer and a Particle Counter Sizer Velocimeter Probe (PCSV-P). Good agreement was found between the temperature predictions and the measurements. In situ particle size distributions were predicted accurately using the Baum and Street model with a swelling factor of zero. The numerical modeling indicated that the Type II flow issued from the burner could be transformed into Type III flow, by eliminating swirl from the primary air stream, which provided the preferred ...

International Nuclear Information System (INIS)

In this work, a mixed cationic--anionic [i.e. cetyltrimethylammonium bromide-sodium octyl sulphate] surfactant system was used to synthesize the magnetite particles. The loading content of iron ions (Fe"3"+ and Fe"2"+) into the surfactant system was varied to study its effect on the formation of magnetite, magnetic and morphological properties of the magnetite particles encapsulated by the surfactant vesicles. It has been verified that the vesicle-encapsulated magnetite particles with sizes from 100 to 200 nm were formed, which were almost independent of the loading content of iron ions. However, the morphological structure of the magnetite particles was dependent on the loading content of iron ions and there existed an optimal loading content for a full packing of the surfactant vesicles with the magnetite particles.

British Library Electronic Table of Contents (United Kingdom)

All-atom molecular dynamics simulations were used to study the morphology of polymer/inorganic composite particles prepared by heterocoagulation. The results were also compared to those of our previous study of the preparation of TiO2/poly(acrylic acid-co-methyl methacrylate) and Fe3O4/polystyrene composite particles. In the simulation system, polymer or inorganic particles were simulated by surface-charge-modified C60 or Na atoms. Through a combination of analysis of the radial distribution functions of charged atoms and snapshots of the equilibrated structure, three kinds of particle distributions were observed under different conditions. When the polymer and inorganic particles had opposite surface charges and their sizes were very different, the composite morphology showed a core-shell...

Energy Technology Data Exchange (ETDEWEB)

A large detector with high redundancy is used to search for various types of anomalous particles in cosmic rays at sea level. The detector is sensitive to zenith angles between 45/sup 0/ and 90/sup 0/. Previously obtained limits on the fluxes of charge (1/3) and (2/3) particles are reduced to 2.9 x 10/sup -10/ and 2.6 x 10/sup -10/ cm/sup -2/sr /sup -1/ sec/sup -1/, respectively. The flux of ionizing tachyons is determined to be less than 2.4 x 10/sup -9/ cm/sup -2/ sr/sup -1/ sec/sup -1/. The massive-particle flux limit we obtain is inconsistent with previous claims of such particles assuming that these particles are isotropic in zenith angle.

British Library Electronic Table of Contents (United Kingdom)

Wood plastic composites (WPCs) are comprised of wood flour and thermoplastic polymer. The matrix is typically high-density polyethylene, poly (vinyl chloride), or polypropylene. The effect of morphology and micromechanics of wood flour particles on the mechanical performance of the bulk composite is a relatively unexplored area. The knowledge about the in situ properties of wood particles and the interfacial properties between the wood particles and the polymer matrix in the bio-composites is very limited. The objective of this work is to characterize the full-field deformation and strain distribution in and around wood particles embedded in polymer matrix. The mechanical tests are performed in small-scale tensile loading stage on thin composite samples containing 1-3 wood particles orient...

British Library Electronic Table of Contents (United Kingdom)

An exposure chamber is described for the quantifiable addition of fine and ultrafine aerosol particulate matter directly to cells and used to demonstrate the in vitro cytotoxicity of fine 1,4-naphthoquinone particles to murine lung epithelial cells. The electrostatic particulate dosage and exposure system (EPDExS) operates on the principle of electrostatic precipitation and is shown to deposit fine and ultrafine aerosol particles directly to cells with 100% efficiency for particle diameters in the range of 40-530nm. This range is not limited by the EPDExS, but rather by the aerosolization method used for this study. Numbers of particles deposited onto the cells are counted with a condensation particle counter, negating any need to calculate or estimate particle exposure. The process of par...

CERN Document Server

We present physical properties of two submillimeter selected gravitationally lensed sources, identified in the Herschel Astrophysical Terahertz Large Area Survey. These submillimeter galaxies (SMGs) have flux densities > 100 mJy at 500 um, but are not visible in existing optical imaging. We fit light profiles to each component of the lensing systems in Spitzer IRAC 3.6 and 4.5 um data and successfully disentangle the foreground lens from the background source in each case, providing important constraints on the spectral energy distributions (SEDs) of the background SMG at rest-frame optical-near-infrared wavelengths. The SED fits show that these two SMGs have high dust obscuration with Av ~4 to 5 and star formation rates of ~100 M_sun/yr. They have low gas fractions and low dynamical masses compared to 850 um selected galaxies.

British Library Electronic Table of Contents (United Kingdom)

This study investigated the occurrence of free-living amoebae (FLA) in immunodeficiency wards of hospitals in Tehran, Iran. A total of 70 dust and biofilm samples from wards serving transplant, pediatric (malignancies), HIV, leukemia and oncology patients of five university hospitals were collected and examined for the presence of FLA using culturing and molecular approaches. Based on the morphology of the amoebae in plate cultures, primer sets were applied for molecular identification of Acanthamoeba, vahlkampfiid amoebae and Hartmannella. Out of 70 samples, 37 (52.9%) were positive for FLA. Acanthamoeba belonged to the T4 genotype was the most prevalent isolate. Presence of the T4 genotype on medical instruments, including an oxygen mask in an isolation room of an immunodeficiency pediat...

Energy Technology Data Exchange (ETDEWEB)

Thermoluminescence of inorganic dust extract from herbs and spices has been demonstrated to be a useful method to discriminate irradiated food products as well as to estimate the total dose exposure. The time evolution of infrared stimulated luminescence has been systematically investigated in potassium feldspar and albite minerals subjected to different doses of gamma irradiation (ranging from 0 to 8 kGy). Experimental results reveal a 300-600 nm signal which is greatly intensified for irradiated samples, following the same irradiation dose dependence observed in thermoluminescence. The luminescence intensity disappears after few seconds of illumination, following a time evolution which is proportional to (1 + Bt){sup -P}. The influence of both B and P factors upon the irradiation dose has been systematically analysed. (author)

International Nuclear Information System (INIS)

The production of atmospheric pollutants in combustion processes depends on plant characteristic, combustion conditions and fuel quality. The influence of fuel quality on the emission of sulphur oxides, nitrogen oxides, carbon monoxide, dust and carbon dioxide and on the emission of some toxic pollutants, such as heavy metals and polycyclic aromatic hydrocarbons, is analysed. The comparison between the emission limits, fixed by the Italian legislation, and the uncontrolled pollutant emissions, produced by fossil fuel combustion in power plants and industrial use, shows that, in order to comply with the limits, a reduction of pollutant emissions is required through the use of abatement systems and cleaner fuels where natural gas has a primary role. The use of cleaner fuels is particularly required in heating plants and appliances for the residential sector, where the development of new gas technologies further increases the environmental advantages of natural gas in ...

CERN Document Server

The junction conditions for General Relativity in the presence of domain walls with intrinsic spin are derived in three and higher dimensions. A stress tensor and a spin current can be defined just by requiring the existence of a well defined volume element instead of an induced metric, so as to allow for generic torsion sources. In general, when the torsion is localized on the domain wall, it is necessary to relax the continuity of the tangential components of the vielbein. In fact it is found that the spin current is proportional to the jump in the vielbein and the stress-energy tensor is proportional to the jump in the spin connection. The consistency of the junction conditions implies a constraint between the direction of flow of energy and the orientation of the spin. As an application, we derive the circularly symmetric solutions for both the rotating string with tension and the spinning dust string in three dimensions. The rotating string with tension ...

Energy Technology Data Exchange (ETDEWEB)

A totally-enclosed, fan-cooled, rib-cooled type induction motor is adopted for an exhauster which is to be installed in a ventilation station for dust catcher in a tunnel. It has the highest capacity in Japan for the above purpose, and is provided with a cooling fan inside to recirculate cooled air, thereby improving cooling efficiency and reducing size and weight. Three-row combined angular ball bearings are used as the thrust bearings, and grease lubrication system is adopted to simplify the inspection/maintenance works. It is to be delivered to Japan Highway Public Corporation's Shizuoka Construction Bureau, Yaizu site office. Its electric specifications are 455 kW, 440 V, 890 A and 510 rpm, and its mechanical specifications are thrust load: 16 kN and impeller load: 7.2 kN. (translated by NEDO)

Energy Technology Data Exchange (ETDEWEB)

The most effective way to generate electricity out of biomass is the gasification and the use of the gas in a gas engine. The conversion of the organic carbon with the gasification of biomass is higher than 95 %. Depending on the gasification concept, the efficiency of gasifiers is found between 70 and 90 %. If the pyrolysis gas is used in a gas engine, an electric efficiency of about 26 % referring to the primary amount of energy can be obtained. With efficient gas cleaning (cleaning for tar and dust), pyrolysis gas is well qualified for engine combustion. Through modern state of engine controlling there are ways to have complete control of the fluctuations in the gas composition. Furthermore, the minor calorific value of offered wood gas poses no problem for turbo charged lean-burn gas engines. (orig.)

International Nuclear Information System (INIS)

An incinerator for the treatment of low-level radioactive solid wastes was installed in Tokai Research Establishment, JAERI, 1966. The incinerator was equipped with a scrubber, cyclone, electrostatic precipitator and HEPA filter. The retention factor (R.F.) of the furnace as well as the decontamination factors (D.F.) of each dust collector were measured using "3"2P as a tracer under various conditions. It was found that the overall D.F. of the incinerator was improved by the increase of the temperature in the furnace, decrease of the off gas flowrate, increase of the charged voltage of the electrostatic precipitator and by the increase of the liquid gas ratio of the scrubber. The overall D.F. of the incinerator (including the R.F. in the furnace) on the standard operating conditions was 9.1x10"6. (auth.).

International Nuclear Information System (INIS)

We consider perturbations of a particular type (homogeneous of Bianchi type IX) from a closed Friedmann-Robertson-Walker model. By considering a perfect fluid, we obtain closed-form solutions for the perturbations in three interesting cases: stiff matter, radiation, and dust. As a cosmological application, we obtain an upper limit on the relative shear, (sigma/theta)_0 < b/sub 0exp/, if the microwave background radiation was last scattered at a mean red-shift element of [7,10"3] and the density parameter is #OMEGA# element of (1,10), where b/sub 0exp/ is the relative root-mean-square deviation of the temperature over the whole sky.

British Library Electronic Table of Contents (United Kingdom)

Based on the information system characteristics of mine, proposed network architecture design of the mine property. And in this framework based on the design of three-dimensional virtual mine described the application of intelligent management platform. Three-dimensional virtual underground mine that shows the situation, the core application is through remote monitoring system of information exchange between devices (material object communication). Internet of things in the framework of mining three-dimensional virtual reconstruction of mine. On coal mine safety in the production process of human, machine and environment, control elements and their harmony and unity. 3D virtual mine management platform integrates personnel positioning, dust control, gas monitoring, roof pressure monitoring...

British Library Electronic Table of Contents (United Kingdom)

ARIES-AT is a 1000MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of ...

International Nuclear Information System (INIS)

We present local two-dimensional and three-dimensional hybrid numerical simulations of particles and gas in the midplane of protoplanetary disks (PPDs) using the Athena code. The particles are coupled to gas aerodynamically, with particle-to-gas feedback included. Magnetorotational turbulence is ignored as an approximation for the dead zone of PPDs, and we ignore particle self-gravity to study the precursor of planetesimal formation. Our simulations include a wide size distribution of particles, ranging from strongly coupled particles with dimensionless stopping time #tau#_s #ident to# #OMEGA#t_s_t_o_p = 10"-"4 (where #OMEGA# is the orbital frequency, t_s_t_o_p is the particle friction time) to marginally coupled ones with #tau#_s = 1, and a wide range of solid abundances. Our main results are as follows. (1) Particles ...

UK PubMed Central (United Kingdom)

Domestic, low-level exposure to radon gas is considered a major environmental lung-cancer hazard involving DNA damage to bronchial cells by α particles from radon progeny. At domestic exposure...Full Text Available

International Nuclear Information System (INIS)

Russian 1986. p. 339. USSR Smirnov, AV Antropov, AE Osorio, VF Zarubin,

CERN Multimedia

Out of Gear $10 billion particle collider hasn't smashed a thing, but scientists still have high hop

Energy Technology Data Exchange (ETDEWEB)

Flow fields, temperature distributions, and particle trajectories in a 2-stage entrained-flow gasifier are calculated using a CFD code, FLUENT. Realizable k- {epsilon} model is used as a turbulent model. Because of swirling flow there appear recirculation regions near the burners. The characteristics of flow fields and temperature distributions in the gasifier are dependent on the swirl number of the system. Mean residence time of the particles in the reductor is inversely proportional to particle size, particle density and swirl number. As the swirl number is increasing, the particles injected from the combustor burners approach the wall near the combustor burners, which prevents the particles from entering the reductor and thus attaching the reductor wall. If the lower combustor burner angle is larger than the higher combustor burner angle for a given swirl ...

International Nuclear Information System (INIS)

The measured result of charged multiplicity in cosmic-ray proton induced nuclear reaction from Chinese satellite emulsion is reported. The correlation of shower and heavy particles is discussed and compared with p-emulsion interactions.

UK PubMed Central (United Kingdom)

This work investigates the effect of excipient particle size on compaction properties of brittle, plastic and viscoelastic materials with and without added lubricants. Sieve cuts of Microcrystalline...Full Text Available

International Nuclear Information System (INIS)

Magnetic particles (MAG*SEP"S"M) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEP"S"M particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEP"S"M particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEP"S"M particles with a gamma ...

UK PubMed Central (United Kingdom)

Transmission electron microscopy analysis (TEMA) was used to analyze the bronchoalveolar lavage fluid (BALF) of 262 subjects occupationally exposed (OE) to nonfibrous mineral particles (NFMP) and 42...Full Text Available

International Nuclear Information System (INIS)

Russian 2008 p. 244 Russian Federation Artemov, SV Yarmukhamedov,

Science.gov (United States)

... and mean rainfall rates, Rm, in the liquid hydrometeor layers using the .... large latitudinal movement of cirrus cloud cover with the changing seasons. ... We study the statistical distribution of PSCs by particle composition using .... the high resolution Cloud Particle Imager (CPI) and standard PMS 2D-C and ...

Energy Technology Data Exchange (ETDEWEB)

The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a Tandem van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.

British Library Electronic Table of Contents (United Kingdom)

The effect of particle/matrix interface debonding on composites consisting of elastic particles and viscoelastic matrix is studied. The interface debonding is represented by a nonlinear cohesive law for the high explosive PBX 9501. The Mori-Tanaka method gives the constitutive relation of the composite in terms of the properties of elastic particles, viscoelastic matrix, and nonlinear cohesive law for interfaces. For the example of a composite with spherical particles subject to hydrostatic tension, simple analytical expressions of the composite stress-strain relation are obtained. The strain rate and temperature have strong effects on the composite behavior. High strain rate and low temperature give high strength of the composite. However, the rate and temperature effects decrease as the ...

Energy Technology Data Exchange (ETDEWEB)

The possible role of space-like objects in elementary particle physics (and in quantum mechanics) is reviewed and discussed, mainly by exploiting the explicit consequences of the peculiar relativistic mechanics of Tachyons. Particular attention is paid: (i) to tachyons as the possible carriers of interactions; (ii) to the possibility of ''vacuum decays'' at the classical level; (iii) to a Lorentz-invariant bootstrap model; (iv) to the apparent shape of the tachyonic elementary particles and its possible connection with the de Broglie wave-particle dualism. (author).

Science.gov (United States)

Dec 12, 2007 ... This is an artist concept of a close-up view of Saturn's ring particles.

Energy Technology Data Exchange (ETDEWEB)

This paper reports on hydrolysis of 10 metal salt aqueous solutions of 6 metal oxides that was conducted in supercritical water. Continuous and rapid production of metal oxide fine particles was achieved by mixing a metal salt aqueous solution with preheated water fed from another line. The reaction time required was less than 2 min. Particle size, morphology, and crystal structure of the obtained metal (hydrous) oxides were examined. Particle size (20 to 600 nm) was different among the system but the size range was relatively narrow in all the cases.

International Nuclear Information System (INIS)

The 'elementary' particle physics began in 1935, when Hideki Yukawa published his pioneering pi-meson theory, and the problem of strong interaction was finally solved 40 years later by the establishment of the Standard Model. The composite models of hadrons by the Sakata school and Sin-itiro Tomonaga's renormalization theory for quantum electrodynamics played essential roles for finding this beautiful solution. It is really surprising that it took only 40 years to solve such desperately difficult problem. The 'elementary' particle physics then split into two new fields, quark-hadron physics' and 'unified (ultimate) theory of particle physics', which are now 30 years old already. (author)

Science.gov (United States)

... operation, experimental data reduction, and application of PES results to studies related to estuarine and coastal sediment transport problems are ...

CERN Document Server

We study diffusion of Cosmic Rays (CRs) in turbulent magnetic fields using test particle simulations. Electromagnetic fields are produced in direct numerical MHD simulations of turbulence and used as an input for particle tracing, particle feedback on turbulence being ignored. Statistical transport coefficients from the test particle runs are compared with earlier analytical predictions. We find qualitative correspondence between them in various aspects of CR diffusion. In the incompressible case, that we consider in this paper, the dominant scattering mechanism occurs to be the non-resonant mirror interactions with the slow-mode perturbations. Perpendicular transport roughly agrees with being produced by magnetic field wandering.

Science.gov (United States)

... 2-93 An Atmospheric Particle Emits Electromagnetic ... atmospheric water vapor produces a hydrometeor. ... subject to wind movement (either blowing ...

Science.gov (United States)

... that defines hydrometeor categories for the duration of the simulation ... and to observe the movement of any particular system ... particle settling occurred ...

Energy Technology Data Exchange (ETDEWEB)

The emission of light charged particles from heavy fragments of uranium fission induced by 153-MeV protons is studied. The probability of their emission is 2.7 x 10{sup - 2} per fission event. It is found that these particles affect the distribution of angles of fragment divergence and the angular distribution of heavy fragments with respect to the primary-proton beam. Experimental results suggest that the preequilibrium emission of particles is correlated with fission. Two mechanisms of interaction between 153-MeV protons and uranium nuclei are considered. 13 refs., 10 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

The behavior of melter feed (a mixture of nuclear waste and glass-forming additives) during waste-glass processing has a significant impact on the rate of the vitrification process. We studied the effects of silica particle size and sucrose addition on the volumetric expansion (foaming) of a high-alumina feed and the rate of dissolution of silica particles in feed samples heated at 5 C/min up to 1200 C. The initial size of quartz particles in feed ranged from 5 to 195 {micro}m. The fraction of the sucrose added ranged from 0 to 0.20 g per g glass. Extensive foaming occurred only in feeds with 5-{micro}m quartz particles; particles {ge}150 {micro}m formed clusters. Particles of 5 {micro}m completely dissolved by 900 C whereas particles {ge}150 {micro}m did not fully dissolve even when the temperature reached 1200 C. Sucrose addition had ...

International Nuclear Information System (INIS)

Russian (Oct 1974). USSR Grantsev, VI Dryapachenko, IP Kornilov,

Energy Technology Data Exchange (ETDEWEB)

A semi-mechanistic model for calculating solid radionuclide release rates from bubbling pools of sodium was developed. The influence of particle spacial and size distributions on the decontamination of the releases was analysed and found significant. Decontamination factors are shown as a function of pool depth, bubbling characteristics and particle size distribution. The calculation of a decontamination factor for estimating the source term of large scale hypothetical core disruptive accidents is presented. The decontamination factor for a large scale accident was found to be two orders of magnitude greater than results obtained from small scale experiments conducted with uniform particle distributions.

International Nuclear Information System (INIS)

... isotopes minutes living radioisotopes nuclei odd-odd nuclei particle properties

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Alpha particles, tritons, deuterons and protons accompanying /sup 252/Cf fission were registered in coincidence with both fission fragments by means of a system containing two-dimensional position-sensitive silicon detectors. Angular distributions, kinetic energy spectra of light charged particles as well as mass distributions of fission fragments in coincidence with light charged particles were measured. The experimental results are compared with some theoretical models.

International Nuclear Information System (INIS)

Short note. 2 refs.; 1 tab.

Science.gov (United States)

... solid particle contamination. Solid particulate impact is a good mechanism for surface heat transfer augmentation. The aug ...

International Nuclear Information System (INIS)

We consider a particle that is subject to a constant force and scatters inelastically on a vibrating periodically corrugated floor. At small friction and for small scatterers the dynamics is dominated by resonances forming spiral structures in phase space. These spiral modes lead to pronounced maxima and minima in the diffusion coefficient as a function of the vibration frequency, as is shown in computer simulations. Our theoretical predictions may be verified experimentally by studying transport of single granular particles on vibratory conveyors.

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)

A new method of particle identification of heavy ions through the measurement of the Bragg curve centroid and particle energy has been developed using a gas ionization chamber with a resistive anode layer. Z-resolutions comparable to the conventional #DELTA#E-E counter telescope could be rather easily attained. (orig.).

Energy Technology Data Exchange (ETDEWEB)

It is shown that a simple algorithm which exactly segregates between adiabatic and non-adiabatic electrons in particle-in-cell simulations of drift modes yields excellent conservation properties (e.g. particle number, energy) compared to the conventional df scheme. The removal of the free streaming term in the evolution of the marker weight is shown to be responsible for the improved linear and nonlinear properties of the simulated plasma.

International Nuclear Information System (INIS)

The evaluation of the hazard posed to the skin by very small radioactive sources (diameter < 1mm) has become popularly known as the 'hot particle' problem in European and American nuclear reactor facilities. In this study, research to detect hot particle was performed in Wolsung Nuclear power plant (NPP) in Korea.

Energy Technology Data Exchange (ETDEWEB)

Zanker has recently presented nomographs for determining particle settling velocities in solid-liquid systems. These nomographs were based on the general correlations developed by Barnea and Mizrahi and Barnea and Mednick. This work presents an equation directly computing particle settling velocities, eliminating the uncertainty associated with nomographs.

Energy Technology Data Exchange (ETDEWEB)

The effect of WC particle size with the addition of VC as a grain growth inhibitor was investigated during the liquid phase sintering of WC-Co system. With increasing WC particle size at the same VC content, the effect of grain growth inhibition was increased. Also, with increasing the VC content, the grain shape of WC was changed from the faceted shape to the distorted shape, and the step density of the WC grain was increased. (orig.)

Energy Technology Data Exchange (ETDEWEB)

This report measured the rate of isothermal deposition of sub-micron particles of magnetite onto the surface of Alloy 800 at pH of 4.2-9.3 at Re=10,000 and a fluid temperature of 25C. Deposition is modelled as a two-step process, the transport of particles to the surface region followed by attachment to the surface.

Energy Technology Data Exchange (ETDEWEB)

Results of an experimental study of the interaction of 140 MeV alpha particles with /sup 90/Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from /sup 90/Zr(..cap alpha..,pp)X reactions, where both of the measured protons have energy ...

UK PubMed Central (United Kingdom)

The retrovirus-like particles of Drosophila are intermediates of retrotransposition of the transposable element copia. In these particles, a 39-nucleotide-long fragment from the 5' region of Drosophila...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A zinc-air battery in a case is described including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit. 7 figures.

International Nuclear Information System (INIS)

From 1946 - 1990, i.e. from shortly after the end of World War II and the rise of the cold war until the German reunification, there had been extensive uranium mining both in Saxony and Thuringia, which formed the southern parts of the former German Democratic Republic. Mining activities started in Saxony in the Ore Mountains (German: Erzgebirge). Mining was conducted by a Soviet, since 1954 by a Soviet- German Incorporated Company named Wismut. It is estimated that about 400,000 persons may have worked in this time period with the company, most of them underground or in uranium ore processing facilities. In the early years, exposure to radiation and dust was particularly high for underground workers. After introduction of several ventilation measures and wet drilling from 1955 onwards, the levels of exposures to the various agents steadily decreased. After German reunification, it was decided by the German Federal Ministry for the Environment to save health data ...

CERN Document Server

We present deep images of dust continuum emission at 450, 800, and 850 micron of the dark cloud LDN 1689N which harbors the low-mass young stellar objects (YSOs) IRAS 16293-2422A and B (I16293A and I16293B) and the cold prestellar object I16293E. Toward the positions of I16293A and E we also obtained spectra of CO-isotopomers and deep submillimeter observations of chemically related molecules with high critical densities. To I16293A we report the detection of the HDO 1_01 - 0_00 and H2O 1_10 - 1_01 ground-state transitions as broad self-reversed emission profiles with narrow absorption, and a tentative detection of H2D+ 1_10 - 1_11. To I16293E we detect weak emission of subthermally excited HDO 1_01 - 0_00. Based on this set of submillimeter continuum and line data we model the envelopes around I16293A and E. The density and velocity structure of I16293A is fit by an inside-out collapse model, yielding a sound speed of a=0.7 km/s, an age of t=(0.6--2.5)e4 yr, and a ...

International Nuclear Information System (INIS)

Moderate-resolution, near-infrared spectra between 0.8 and 5.2 #mu#m were obtained for 12 late-type (K0-M3) disk-bearing members of the #approx#5 Myr old Upper Scorpius OB association using SpeX on the NASA Infrared Telescope Facility. For most sources, continuum excess emission first becomes apparent between #approx#2.2 and 4.5 #mu#m and is consistent with that produced by single-temperature blackbodies having characteristic temperatures ranging from #approx#500 to 1300 K. The near-infrared spectra for 5 of 12 Upper Scorpius sources exhibit Pa#gamma#, Pa#beta#, and Br#gamma# emission, indicators of disk accretion. Using a correlation between Pa#beta# and Br#gamma# emission line luminosity and accretion luminosity, mass accretion rates ( M-dot ) are derived for these sources that range from M-dot = 3.5x10"-"1"0 to 1.5 x 10"-"8 M_s_u_n yr"-"1. Merging the SpeX observations with Spitzer Space Telescope mid-infrared (5.4-37.0 #mu#m) spectroscopy and 24 and 70 #mu#m broadband photometry, ...

Science.gov (United States)

Reactions on the ionizing radiation of 14 Cladosporium cladosporioides strains were studied. Only 5 of them displayed radiotropizm. The ability of C. cladosporioides strains 4 and 5 with positive radiotropizm and museum C. cladosporioides strain 396 and its alb-mutant SM without positive radiotropizm to destruct radioactive particles of Chernobyl and explosion origin was studied. Two ways of radioactive particles destruction by C. cladosporioides were established, one of them is a direct way by fungal overgrowth of hot particles and the second one an indirect way only by fungal metabolites. Mycelium of the studied C. cladosporioides strains sorbed radionuclides from radioactive particles during cultivation on the liquid and agarized media. No certain inclinations of the individual strains to accumulation of radionuclides 137Cs or 152Eu were ascertained. PMID:12664550

Energy Technology Data Exchange (ETDEWEB)

This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert's law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle's projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional ...

International Nuclear Information System (INIS)

Results of experimental investigation into radiation electromagnetic effect (REM) in samples of germanium crystals under approximately 40 MeV #alpha#-particle irradiation in a cyclotron are presented. A high level of excitation, volumetric character of generation of non-equilibrium carriers and formation of defects as well as the form of their spatial distribution are shown to result in some peculiarities of the EMF of the REM effect on the particle flux, fluence and sample parameters. Agreement of theoretical calculations, conducted with account of specificity of #alpha#-particle interaction with a crystal, and experimental data is obtained. It is revealed that the REM effect can be applied in obtaining data on spatial distribution of non-equilibrium carrier concentrations along the particle trajectory in the crystal.

Energy Technology Data Exchange (ETDEWEB)

In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was identified. 12 refs., 8 figs., 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

The nucleation of microdamage under dynamic loading was investigated through planar impact experiments accomplished with a light gas gun. The microscopic observation of recovered and sectioned specimens showed that microcracks were nucleated only by cracking of brittle particles inside material. However, for comparison the in situ static tensile tests on the same material conducted with a scanning electron microscope showed that the microcracks were nucleated by many forms those were fracture of ductile matrix, debonding particles from matrix and cracking of brittle particles. The quantitative metallographic observations of the specimens subjected to impact loading showed that most of the cracked particles were situated on grain boundaries of the aluminum matrix. These facts suggested the concept of critical size and incubation time of submicroscopic cavities in the dynamic case and the mechanism of ...

British Library Electronic Table of Contents (United Kingdom)

High molecular weight products of the ozonolysis reaction of particle-phase 9-octadecenoic acid (oleic acid) have been studied by photoelectron resonance capture ionization (PERCI) mass spectrometry (MS). Oleic acid particles ( Formula Not Shown , Formula Not Shown ) were reacted with ozone (1.8x10-4atm) in a flow reactor at reaction times of 8 and 23s. Particles were sampled on-line with a differentially pumped particle inlet and chemically analyzed by PERCI-MS. PERCI is a soft ionization method that permits the direct measurement of relatively high molecular weight compounds, facilitating molecular identification. In addition to cyclic oxygenates, such as secondary ozonides and geminal diperoxides that were reported previously, we demonstrate the formation of polymers at the particle sur...

British Library Electronic Table of Contents (United Kingdom)

A supercritical fluid-based method is proposed to produce coenzyme Q10 (CoQ10) nanoparticles. First, CoQ10/polyethylene glycol 6000 composite particles are prepared by a modified PGSS (particles from gas-saturated solutions) process with controlling the flow rate of the gas-saturated solution. Then, CoQ10 nanoparticles are obtained by dissolving the composite particles into water. The effect of experimental variables of the modified PGSS process, including pressure, temperature, flow rate of the gas-saturated solution, and mass fraction of CoQ10, on the CoQ10 particle size and particle size distribution was investigated. Results show that CoQ10 slurry product with a median diameter of 190nm and yield of 89.8% can be prepared at an optimum condition (operating pressure of 25MPa, operating t...

British Library Electronic Table of Contents (United Kingdom)

Most active pharmaceutical ingredients (API) exhibit particle size distributions with some degrees of asymmetry deviating from log-normality. A new log-skew-normal (L-S-N) distribution model is proposed for a systematic comparison of the asymmetry effect on content uniformity. The new model originated from the S-N model used by Azzalini gives a close approximation to real API particle size distribution. Monte-Carlo method was employed to simulate the dosage potency distribution. A high risk of over potency is uncovered when either the dose is low or API particle size distribution is positively skewed. This is due to the formation of pseudo heavy tail in potency distribution that decays slower than exponentially. Nomographs of API particle size versus dosage strength were constructed with a...

Energy Technology Data Exchange (ETDEWEB)

The study of the {alpha}-particle energy distributions associated with ND and SD states in {sup 151,152}Dy has been carried out. The Dy isotopes were produced in the reaction {sup 37}Cl+{sup 123}Sb at 191 MeV via the ({alpha}5n) and ({alpha}4n) channels, respectively. In {sup 151}Dy the {alpha}-particle energy distributions associated to ND and SD are very different from each other, both at the low and high energy sides inducing a difference of 3 MeV in the {alpha}-particle mean energy. In {sup 152}Dy the situation is different; the {alpha}-particle spectral shapes are similar and a difference in the {alpha}-particle mean energy of only 0.7 MeV is deduced. A description in terms of energy localization of entry states is given. (orig.)

CERN Document Server

FastSLAM is a framework for simultaneous localization using a Rao-Blackwellized particle filter. In FastSLAM, particle filter is used for the mobile robot pose (position and orientation) estimation, and an Extended Kalman Filter (EKF) is used for the feature location's estimation. However, FastSLAM degenerates over time. This degeneracy is due to the fact that a particle set estimating the pose of the robot loses its diversity. One of the main reasons for loosing particle diversity in FastSLAM is sample impoverishment. It occurs when likelihood lies in the tail of the proposal distribution. In this case, most of particle weights are insignificant. Another problem of FastSLAM relates to the design of an extended Kalman filter for landmark position's estimation. The performance of the EKF and the quality of the estimation depends heavily on correct a priori knowledge of the process ...

Energy Technology Data Exchange (ETDEWEB)

Reductive quenching of two photoexcited ruthenium(II) complexes by an anionic electron donor, 2,2{prime}-azinobis(3-ethyl-benzothiazoline-6-sulfonate) (ABTS{sup 2{minus}}), in aqueous solution was examined by laser flash photolysis before and after adding positively charged colloidal (250-{angstrom} diameter) alumina-coated silica particles. The kinetics and quantum yields of electron transfer with an anionic sensitizer, RuL{sub 3}{sup 4{minus}} (L = bathophenanthroline disulfonate), and a cationic one, Ru(bpy){sub 3}{sup 2+} (bpy = 2,2{prime}-bipyridine), were compared. Coadsorption of ABTS{sup 2{minus}} and RuL{sub 3}{sup 4{minus}} by the particles greatly enhanced the rate of quenching such that only the reaction occurring on the surfaces of the particles was observed. Electron transfer from ABTS{sup 2{minus}} to RuL{sub 3}{sup 4-*} occurred by a static (nondiffusional) process, and the quenching efficiency was maximal ...