WorldWideScience
1

El Roque de Los Muchachos Site Characteristics. III. Analysis of Atmospheric Dust and Aerosol Extinction  

CERN Document Server

Canary Islands are normally interested by dominant North-East winds that, in some meteorological conditions, can transport sand at high altitude from the Sahara desert. The dust may affect the efficiency of the telescopes and decreases the transparency of the sky. In order to maximize the scientific return of the telescopes located at the ORM, we present an analysis of the atmospheric dust content and its effects on astronomical observations. B, V and I dust aerosol astronomical extinction are derived. Using a 5 years series database of data taken from the four channel TNG dust monitor, we compute a mean hourly and daily values of the dust content. We have detected particles having size 0.3, 0.5, 1.0 and 5.0 um. Using a power law we have derived the content of 10.0 um particles. We found a typical local dust concentration ranging from 3x10^6 ...

2008-01-01

2

Grain mantles: The impact on grain evolution and selective extinction  

International Nuclear Information System (INIS)

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

1989-12-01

3

FG Sge at the stage of dust shell ejection  

British Library Electronic Table of Contents (United Kingdom)

New photometric observations of the variable star FG Sge, a rapidly evolving planetary nebula nucleus, were performed in 2003?2008. On 230 nights, we obtained 86 UBV and 155 BV RI (or R c , I c ) magnitude estimates. The maximum amplitude of the V-band light variations was >8 m . Six deep minima and four high maxima were observed. Analysis of the light curve has shown that the pulsation period of the star remained constant since 1991 and was P = 115 days. We have studied the wavelength dependence of the extinction at various phases of the light curve. The blueing of the B-V color at deep minima is interpreted as the result of light scattering in the circumstellar dust shell of the star formed by preceding dust ejections since 1992. Our spectroscopic observations performed on nine nights in...

2009-01-01

4

X-ray and UV-light irradiation effects on oxide superconducting thin films  

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 by the irradiation. From these results we can find that irradiation with the X-ray ...

5

Suppression of pitting corrosion with passive film modification on type 304 stainless steel by ultra-violet light irradiation; Shigaikoshosha ni yoru Type 304 stainless ko no fudotai himaku kaishitsu to koshoku yokusei  

Energy Technology Data Exchange (ETDEWEB)

In this study, the effects of 325nm wavelength ultraviolet light irradiation on pitting corrosion behavior of type 340 stainless steel in a neutral chloride solution are studied. Further, the change of passive film with the light irradiation is analyzed using x-ray photoelectron spectroscopy. The mains results obtained therefrom are stated below. Pitting potential can be shifted in noble direction by the ultraviolet light irradiation. The effect of ultraviolet light irradiation is ore prominent in the pitting corrosion process than that in the passive film formation. The result of the analysis in terms of the birth and death stochastic probability process shows that pitting corrosion rate is decreased remarkably by the ultraviolet light irradiation at the formation of passive film, while the repassivation is slightly expedited by the ultraviolet light irradiation. On the other hand, the repassivation rate is increased a little by the ultraviolet light irradiation during the pitting ...

1998-06-20

6

Free-Electron Lasers: Present Status and Future Prospects  

Energy Technology Data Exchange (ETDEWEB)

Free-electron lasers as scientific instruments are reviewed. The present status and future prospects are delineated with attention drawn to the size, complexity, availability, and performance capability of this new tool. The Free-Electron Laser (FEL) was proposed by John Madey in 1970 (1), although earlier work, relevant to the concept, had been performed by Motz (2) and by Phillips (3). Experimental demonstration was achieved by Madey, et. al. in 1975 and 1976 (4). Since that time, FELs of diverse configurations have been operated at several laboratories around the world. At present, FEL development is focused in two directions: in constructing reliable FELs for scientific research and in extending FEL capability to vacuum ultra-violet (VUV) and even shorter wavelengths. In this article we shall only very briefly review the principles of an FEL, putting emphasis on those aspects that limit performance, after which we shall discuss the applications, present status ...

1990-05-01

7

Comparison of the charge injection barrier at realistic and ideal metal/organic interfaces: metals become faceless  

Energy Technology Data Exchange (ETDEWEB)

Most of the organic electronic devices are nowadays fabricated under poor vacuum conditions. In this regard, there is only little knowledge about the impact of contamination of the metal electrode on the charge injection barrier in this kind of electronic devices. In our study we have performed X-ray and ultra violet photoemission spectroscopy (XPS, UPS) on interfaces between the organic semiconductor -sexithiophene and sputter cleaned (ideal) metals as well as contaminated (realistic) metals. As metal substrates we have used silver, gold, palladium, and platinum. These metals provide us a wide range of metal work functions from 4.2 eV for silver up to 5.5 eV for platinum. For all interfaces of -sexithiophene and contaminated metals we have observed a reduction of the interface dipole and the hole injection barrier. The charge injection barrier in all four cases is almost independent of the underlying metal (within an error of 0.2 eV) and the ...

2007-07-01

9

WWF - Global Warming Capable of Sparking Mass Species Extinctions  

Science.gov (United States)

... of species extinctions in around the world if global warming continues unabated, according to a new study published ... ...

10

Structure and kinematics of edge-on galaxy discs - I. Observations of the stellar kinematics  

CERN Document Server

We present deep optical long-slit spectra of 17 edge-on spiral galaxies of intermediate to late morphological type, mostly parallel to their major axes and in a few cases parallel to the minor axes.The line-of-sight stellar kinematics are obtained from the stellar absorption lines using the improvedc ross-correlation technique. In general, the stellar kinematics are regular and can be traced well into the disc-dominated region. The mean stellar velocity curves are far from solid-body, indicating that the effect of dust extinction is not large. The line-of-sight stellar disc velocity dispersion correlates with the galaxy maximum rotational velocity, but detailed modeling is necessary to establish whether this represents a physical relation. In four spirals with a boxy- or peanut-shaped bulge we are able to detect asymmetric velocity distributions, having a common signature with projected radius in the mean line-of-sight velocity and the $h_{3}$ ...

2004-01-01

11

Multi-wavelength observations of the young binary system Haro 6-10: The case of misaligned discs  

CERN Document Server

Context. We present a multi-wavelength, high-resolution observational survey of the young binary system Haro 6-10 (GV Tau, IRAS 04263+2426), which is harbouring one of the few known infrared companions. Aims. The primary goal of this project is to determine the physical and geometrical properties of the circumstellar and circumbinary material in the Haro 6-10 system. Methods. High-resolution optical (HST/WFPC2) and near-infrared (VLT/NACO) images in different bands were analysed to investigate the large-scale structures of the material around the binary.Mid-infrared interferometry (VLTI/MIDI) and spectroscopy (TIMMI2 at the 3.6m ESO telescope) were carried out to determine the structure and optical depth of the circumstellar material around the individual components. Results. The multi-wavelength observations suggest that both components of the binary system Haro 6-10 are embedded in a common envelope. The measured extinction indicates a dust ...

2011-01-01

12

Modeling the Galactic CV Distribution for the ChaMPlane Survey  

CERN Document Server

For purposes of designing targeted cataclysmic variable (CV) detection surveys and interpreting results of other projects with many CV detections such as the ChaMPlane Survey, we have created a model of the CV distribution in the Galaxy. It is modeled as a warped, flared exponential disk with a gaussian vertical distribution. Extinction is based on a detailed Galactic dust and gas model. A luminosity function for CVs is also incorporated, based on a smoothed version of published data. We calculate predicted field detection rates as a function of the limiting magnitude expected for the detecting system (i.e. WIYN/Hydra or NOAO 4m/Mosaic). Monte-Carlo techniques are used to assess statistical fluctuations in these rates. We have created maps of the expected CV distribution for the full non-bulge Galactic plane (20

2007-01-01

14

Parallels between playbacks and Pleistocene tar seeps suggest sociality in an extinct sabretooth cat, Smilodon  

UK PubMed Central (United Kingdom)

Inferences concerning the lives of extinct animals are difficult to obtain from the fossil record. Here we present a novel approach to the study of extinct carnivores, using a comparison between fossil...Full Text Available

2009-02-23

15

7257 - NASA Technical Reports Server  

Science.gov (United States)

Mar 1, 2011 ... Molar extinction coefficients of hydrogen iodide in the Schumann region. Author: De More, W. B.; Raper, O. F.. Abstract: Molar extinction ...

16

Hazards of explosives dusts  

Energy Technology Data Exchange (ETDEWEB)

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

1989-01-01

17

Dynamics of southwest Asian dust particle size characteristics with ...  

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 ...

18

Compaction of dust clumps in a protostellar cloud  

Energy Technology Data Exchange (ETDEWEB)

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

1984-01-01

19

Aluminum-Zinc (Al-Zn) Dust Analyses for Recycling Purposes  

Science.gov (United States)

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

2011-08-01

20

Hydroxylation of 3-Nitrotyrosine and Its Derivatives by Gamma Irradiation  

Science.gov (United States)

... the hydroxyl group with the benzene ring. The molar extinction coefficients for the various species at their respective absorption ... Glya Recorded by 1H-NMR Spectroscopy TABLE 2 Molar Extinction Coeff...

21

Historical Mammal Extinction on Christmas Island (Indian Ocean) Correlates with Introduced Infectious Disease  

UK PubMed Central (United Kingdom)

It is now widely accepted that novel infectious disease can be a leading cause of serious population decline and even outright extinction in some invertebrate and vertebrate groups (e.g., amphibians)....Full Text Available

22

Habituation of unconditioned fear can be attenuated by the presence of a safe stimulus: Assessment using the neophobic response of the rat  

UK PubMed Central (United Kingdom)

Protection from extinction of conditioned fear has been demonstrated when a conditioned inhibitor of fear is presented during extinction treatment. The present study assessed if similar results...Full Text Available

2008-01-01

23

Evidence from ammonoids and conodonts for multiple Early Triassic mass extinctions  

UK PubMed Central (United Kingdom)

Ammonoids and conodonts, being characterized by exceptionally high background rates of origination and extinction, were vulnerable to global environmental crises, which characteristically intensified...Full Text Available

2009-09-08

24

Platinum Acetylide Two-Photon Chromophores (Preprint)  

Science.gov (United States)

... ligands. Wavelength maxima and molar extinction coefficients are given in Tables 1 and 2. Compared to their 9 Page 14. ...

2007-04-01

25

Excitation Energy Transfer Study of the Spatial Relationship ...  

Science.gov (United States)

... closely correlated to the amount of re- centration. The molar extinction coefficients were agent added to the enzyme. The naphtha- ...

1988-02-15

26

Rocks, minerals, and a dusty world  

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 ...

1993-12-31

27

Imaging-based dust sensors: equipment and methods  

Science.gov (United States)

Dust detection and control in real time, represent one of the most challenging problem in all those environments where fine and ultrafine airborne particulate solids products are present. The presence of such products can be linked to several factors, often directly related and influenced by the working-production actions performed. Independently from the causes generating dust, airborne contaminants are an occupational problem of increasing interest as they are related to a wide number of diseases. In particular, airborne dusts are well known to be associated with several classical occupational lung diseases, such as the pneumoconiosis, especially at high levels of exposure. Nowadays there is also an increasing interest in other dust related diseases, from the most serious as cancer and asthma, to those related with allergies or irritation and other illnesses, also occurring at lower levels of ...

2004-05-01

28

Direct Stellar Radiation Pressure at the Dust Sublimation Front in Massive Star Formation: Effects of a Dust-free Disk  

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 irradiation. Thus, ...

2011-10-01

29

Complex plasma: dusts in plasma  

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 wavelength, while the dust particles move in a slow time scale and a long spatial scale. Some fundamental ...

2007-04-21

30

The dust distribution in edge-on galaxies. Radiative transfer fits of V and K'-band images  

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 ...

2007-01-01

31

The Structure of the Dust Mite Allergen Der p 7 Reveals Similarities to Innate Immune Proteins  

UK PubMed Central (United Kingdom)

BackgroundSensitization to house dust mite allergens is strongly correlated with asthma. Der p 7 elicits strong IgE antibody and T-cell responses in mite allergic...Full Text Available

2010-04-01

32

Species-specific Fungal DNA in Airborne Dust as Surrogate for Occupational Mycotoxin Exposure?  

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

33

EF Cha: Warm Dust Orbiting a Nearby 10 Myr Old Star  

CERN Document Server

Most Vega-like stars have far-infrared excess (60micron or longward in IRAS, ISO, or Spitzer MIPS bands) and contain cold dust (~ 4% of the stars in nearby young stellar associations.

2007-01-01

34

Decrease in dust content and removal of sludge during drilling ascending shafts in coal  

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.

1983-01-01

35

APOD: 2011 January 26 - The Whirlpool Galaxy in Infrared Dust  

Science.gov (United States)

Clicking on the image will bring up the highest resolution version available. The Whirlpool Galaxy in Infrared Dust Credit: Infrared: NASA, ESA, M. Regan & B. Whitmore (STScI),...

2011-10-07

36

APOD: 2004 September 5 - M51: The Whirlpool Galaxy in Dust and...  

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....

2011-10-07

37

APOD: 2001 April 10 - M51: The Whirlpool Galaxy in Dust and Stars  

Science.gov (United States)

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

2011-10-07

38

A Controlled Challenge Study on Di(2-ethylhexyl) Phthalate (DEHP) in House Dust and the Immune Response in Human Nasal Mucosa of Allergic Subjects  

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

2008-11-01

39

Mixed-ligand tungsten-antipyrine-trihydroxyfluorone complexes and their use in analysis  

International Nuclear Information System (INIS)

In order to increase the sensitivity of photometric determination of tungsten and to find forms with high molar extinction coefficients, mixed-ligand complexes of tungsten with antipyrine and trihydroxyfluorone have been studied. The molar extinction coefficients have been determined for chloride associates of mixed-ligand complexes containing different trioxyfluorones: phenylfluorone, salicylflourone, p-bromphenylfluorone, anthrafluorone, dioxyfluorescein, and dioxyfluoroscein ethylate (DOFE). An associate formed by DOFE has the maximum molar extinction coefficient. It has been used for photometric determination of microgram amounts of tungsten impurity in vanadyl sulphate.

1977-01-01

40

Thio and Seleno Rhodamine Derivatives as Reversal Agents ...  

Science.gov (United States)

... Values of absorption maxima, X.nax, and associated molar extinction coefficients, c, as well as values of the n-octanol/water partition coefficient( ...

2005-09-01

41

Spatial Relationships between Drug Binding Sites on the ...  

Science.gov (United States)

... determination of the molar extinction coefficients, e, were measured by the Lowry method with native a-toxin as a standard. Binding Kinetics. ...

1987-10-15

42

Phase-Sensitive Fluorescence Study of Mono-L-Aspartyl ...  

Science.gov (United States)

... of perylene were measured with the Shimadzu UV-2500 UV-VIS spectrophotometer (Kyoto, Japan) to determine their molar extinction coefficients. ...

2001-10-25

43

Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment II.  

Science.gov (United States)

This is a continuation of our paper [Liu, M., Wang, K., 2010. Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment, J. Theor. Biol. 264, 934-944]. Taking both white noise and colored noise into account, a stochastic single-species model under regime switching in a polluted environment is studied. Sufficient conditions for extinction, stochastic nonpersistence in the mean, stochastic weak persistence and stochastic permanence are established. The threshold between stochastic weak persistence and extinction is obtained. The results show that a different type of noise has a different effect on the survival results. PMID:20816991

2010-09-08

44

Opposed jet diffusion flames of nitrogen-diluted hydrogen vs air - Axial LDA and CARS surveys; fuel/air rates at extinction  

Science.gov (United States)

An experimental study of H-air counterflow diffusion flames (CFDFs) is reported. Coaxial tubular

1989-01-01

45

Global warming and amphibian losses (PDF, 2 pp., 437.59 KB)  

Science.gov (United States)

Is global warming contributing to amphibian declines and extinctions by promoting outbreaks of the chytrid fungus Batrachochytrium dendrobatidis? Analyzing patterns ... ...

46

Frequency-Domain Optical Mammogram  

Science.gov (United States)

... where i is the wavelength index (ranging from 1 to 4), while Esb and FHb02 are the molar extinction coefficients of deoxy-hemoglobin and oxy ...

2002-10-01

47

ADDITION AND SUBSTITUTION PRODUCTS OF OXYGEN ...  

Science.gov (United States)

... 5.9-585/T; thermal stability; solubility in liquid nitrogen, oxygen and Freons; molar extinction coefficients in the visible range and EPR spectrum. ...

1965-01-05

48

Fungi of the house dust in Riyadh, Saudi Arabia.  

Science.gov (United States)

30 species belonging to 18 genera were isolated from floor dust of 30 homes in Riyadh. Out of them 16 species and 10 genera were isolated from dust of air conditioners of the same homes. The most common genera in floor dust were Aspergillus, Penicillium and Cladosporium. Aspergillus repens, A. amstelodami, A. versicolor, A. fumigatus, Penicillium purpurogenum, P. crustosum, Cladosporium cladosporoides and C. herbarum were frequently isolated. The most abundant genera in air conditioner dust were Aspergillus and Penicillium. Aspergillus fumigatus, A. ochraceus, A. terreus, Penicillium oxalicium and P. crustosum were most frequent species. PMID:2330766

1990-01-01

49

On the properties of plasma crystals  

Energy Technology Data Exchange (ETDEWEB)

When a plasma becomes contaminated by foreign particles, generically referred to as dust, the result is called a dusty plasma. At the present time there is a great deal of interest in dusty plasmas because of their roles in terrestrial and extra-terrestrial processes - semiconductor processing, high temperature fusion experiments, stellar formation and the rings of Saturn. This thesis is concerned with the role of dust in processing type plasmas. In the following experiments, artificial dust is introduced into a parallel electrode plasma chamber. Ions and electrons in the plasma charge the dust particles and they become suspended in the plasma due to the balancing of electric and gravitational forces. By illuminating the suspended dust with laser light and using an extremely high speed camera fitted with a macro lens to look at the scattered light, the dust ...

1999-07-01

50

Dust resuspension and transport modeling for loss of vacuum accidents  

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, ...

2007-07-01

51

Dust resuspension and transport modeling for loss of vacuum accidents  

International Nuclear Information System (INIS)

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, ...

2007-10-05

52

Molar extinction coefficients in aqueous solutions of some alkaline earth chlorides  

International Nuclear Information System (INIS)

Molar extinction coefficients for the solid solutes in aqueous solutions of some alkaline earth chlorides such as MgCl_2.6H_2O, CaCl_2, SrCl_2.6H_2O and BaCl_2.2H_2O have been determined at 81, 356, 511, 662, 1173 and 1332 keV energies in different concentration using the narrow beam transmission methods. (author)

1999-12-21

53

Asymptotic properties and simulations of a stochastic logistic model under regime switching  

British Library Electronic Table of Contents (United Kingdom)

Taking both white noise and colored environmental noise into account, a general stochastic logistic model under regime switching is proposed and studied. Sufficient conditions for extinction, nonpersistence in the mean, weak persistence, stochastic permanence and global attractivity are established. The critical number between weak persistence and extinction is obtained. Moreover, some simulation figures are introduced to illustrate the main results.

2011-01-01

54

Preparation of immission dust samples for the analysis of toxic substances in dust by atomic emission spectroscopy with inductively coupled plasma  

International Nuclear Information System (INIS)

Samples of air-dust-concentration- and air-dust-deposit measurements were digested by a standardized wet digestion procedure and the amounts of substances in the dust according to class I TA Luft by Atomic Emission Spectroscopy with Inductively Coupled Plasma (AES-ICP). The characteristic values for procedures according to VDI 2449, sheet 1, were determined for lead, vanadium, cadmium, chromium, copper, nickel and zinc. By partial automatic control of the digestion procedure the personel expenditure of work could be reduced by a factor 13. Dust filter samples were analysed without sample preparation by evaporating the material with a solid state laser. The absolute detection limit was between 1 and 100 ng/cm"2 for the elements arsenic, cadmium, cobalt, chromium, mercury, antimony, selen and thallium. For sampling by means of the Beta-Staubmeter the relative detection limits for the laser-ICP were ...

55

Physico-chemical behaviour of a barrier composed of cement kiln dust and fly ash; Comportement physico-chimique d'une barriere a base de poussieres de four de cimenterie et de cendres volantes  

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 ...

2000-07-01

56

Design and analysis of a dust extraction system  

Energy Technology Data Exchange (ETDEWEB)

A dust extraction system removes the contaminated air at source by means of a hood. The extraction system for dust is essentially a ducted air system that prevents excessive employee exposure to dust in the working zone. The four major mechanisms that remove the contaminants in an extraction system are: - capture of contaminants by hoods - transport of contaminated air in duct network - separation of dust in the collector - exhaust of clean air through stack. The current methods of design are based on empirical relations, multi-variable tables, graphs and nomographs that have been derived from the principle of fluid mechanics and particle dynamics. However, the empirical formulae, tables and graphs are used in different geographical locations of the world having different environmental conditions and geo-characteristics of dust particles. Therefore, it is required to establish a ...

2006-07-01

57

Origin of binary stars  

Energy Technology Data Exchange (ETDEWEB)

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

1983-03-01

58

chapter 5 - NASA's History Office  

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. ...

59

Waste and dust utilisation in shaft furnaces  

Energy Technology Data Exchange (ETDEWEB)

Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilised e.g. in agglomeration processes (sintering, pelletising or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverised coal (PC) has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

2005-07-01

60

Toward finding an optimal stockpile geometry to reduce dust emissions  

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 ...

2006-07-01

62

NASA - Spitzer Sees Spider Web of Stars  

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...

2011-07-20

63

Lung cancer in rats exposed to fibrogenic dusts  

Energy Technology Data Exchange (ETDEWEB)

Fischer-344 rats were exposed to quartz dusts and to quartz-bearing oil shale dusts in long-term inhalation studies. Aerosol concentrations of 12 mg/m/sup 3/ and 152-176 mg/m/sup 3/ for quartz and shale dusts, respectively, were used in exposure regimens lasting up to two years. Pulmonary fibrosis was observed in most animals surviving beyond 400 days. Adenocarcinomas and epidermoid carcinomas of the lung were observed in animals from all exposure groups, including those exposed to quartz alone. The pulmonary tumors were a late effect, with the earliest lung tumor being observed after 651 days. 13 references, 10 figures, 4 tables.

1984-01-01

64

GALAXY EVOLUTION EXPLORER (GALEX) GUEST ... - GALEX - NASA  

Science.gov (United States)

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

65

Comparative toxicity in rats vs hamsters of inhaled radon daughters with and without uranium ore dust  

International Nuclear Information System (INIS)

Simultaneous exposures of rats and hamsters to inhaled radon daughters, with and without uranium ore dust, were performed daily for five months. Pulmonary pathology developing in 6 to 13 mo after cessation of daily exposures included interstitial fibrosis, emphysema, epithelial hyperplasia, squamous metaplasia, and malignant neoplasia. Rats showed a greater variety and more severe response to these uranium mine inhalation exposures than did hamsters. Inhalation of radon daughters with uranium ore dust displayed the site of greatest damage, including squamous carcinoma, from the nasopharynx to the lungs. Sixty percent of the rats exposed to radon daughters with ore dust developed primary pulmonary carcinomas, providing an appropriate short-term experimental animal model for investigation of respiratory tract carcinogenesis in uranium miners.

1977-05-01

66

metabotropic glutamate receptor 5 (mGluR5) has a critical role in inhibitory learning  

UK PubMed Central (United Kingdom)

The mechanisms that contribute to the extinction of previously acquired memories are not well understood. These processes, often referred to as inhibitory learning, are thought to be parallel...Full Text Available

2009-03-25

67

The evolution of fossoriality and the adaptive role of horns in the Mylagaulidae (Mammalia: Rodentia)  

UK PubMed Central (United Kingdom)

Ceratogaulus, a member of the extinct fossorial rodent clade Mylagaulidae, is the only known rodent with horns and the smallest known horned mammal. The function of the large, dorsally...Full Text Available

2005-08-22

68

Spectrophotometry of H II regions in the spiral galaxy M101  

Energy Technology Data Exchange (ETDEWEB)

Spectral line intensity data are presented for ionized hydrogen regions in the giant spiral galaxy M101. The influence of interstellar extinction is assessed and electron temperatures of the gas clouds are derived.

1981-04-01

69

Molar extinction coefficients of some biologically important substances  

International Nuclear Information System (INIS)

Reliable values of x-ray and gamma-ray attenuation coefficients of elements and compounds are required in spectrometry as well as in many other scientific, engineering and medical disciplines involving photon radiation

2002-11-15

70

Linking global warming to amphibian declines through its effects on female body condition and survivorship (PDF, 7 pp., ...  

Science.gov (United States)

There is general consensus that climate change has contributed to the observed decline, and extinction, of many amphibian species throughout the world. ... ...

71

Interactions in multiple schedules: negative induction with squirrel monkeys1  

UK PubMed Central (United Kingdom)

In Experiment I, lever pressing by squirrel monkeys was maintained under a sequence of variable-interval, multiple variable-interval variable-interval, and multiple variable-interval extinction schedules...Full Text Available

1978-11-01

72

Forecasting changes in amphibian biodiversity: aiming at a moving target  

UK PubMed Central (United Kingdom)

Amphibian population declines and sudden species' extinctions began to be noted at the beginning of the 1980s. Understanding the causes of the losses is hampered by our poor knowledge of the amphibian...Full Text Available

2005-02-28

73

Evolutionary history and the effect of biodiversity on plant productivity  

UK PubMed Central (United Kingdom)

Loss of biological diversity because of extinction is one of the most pronounced changes to the global environment. For several decades, researchers have tried to understand how changes in biodiversity...Full Text Available

2008-11-04

74

EXTINCTION OF EXPERIMENTAL TRIATOMA INFESTANS POPULATIONS FOLLOWING CONTINUOUS EXPOSURE TO DOGS WEARING DELTAMETHRIN-TREATED COLLARS  

UK PubMed Central (United Kingdom)

Dogs are domestic reservoir hosts of Trypanosoma cruzi, the etiological agent of Chagas disease. We evaluated the effect of deltamethrin-treated dog collars (DTDCs) over time...Full Text Available

2006-05-01

75

Cylindrical stretched flame  

Energy Technology Data Exchange (ETDEWEB)

For sufficiently cool remote gases, the cylindrical stretched flame shows classical ignition-extinction behavior. For remote gas temperatures close to the adiabatic flame temperature, the flame response is qualitatively different, with negative flame speed solutions which may be physically accessible.

1984-06-01

76

Biologic Rhythms Derived from Siberian Mammoths' Hairs  

UK PubMed Central (United Kingdom)

Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned...Full Text Available

77

Average uncertainty as a determinant of observing behavior1  

UK PubMed Central (United Kingdom)

After discrimination training on a multiple variable-interval extinction schedule of food reinforcement, pigeons were placed on the uncued or mixed version of the same schedule and allowed to make...Full Text Available

1974-09-01

78

The biokinetics of four sup 239 Pu/ sup 241 Am dioxide bearing dusts in the rat after inhalation: the implications for occupational exposure  

Energy Technology Data Exchange (ETDEWEB)

The aims of the work described here were to provide an experimental basis for evaluating the committed effective dose equivalent per unit intake together with the ALI for four industrial oxide bearing dusts, and to assess the extent to which {sup 241}Am could be used for estimating the {sup 239}Pu content of the lung after an accidental intake of these materials. (author).

1991-01-01

79

Rotational modes of oscillation of rodlike dust grains in a plasma  

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.

2003-01-01

80

Non-neoplastic pulmonary disease from inhaled radon daughters with uranium ore dust in beagle dogs  

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.

1977-05-01

81

Mineralogy of clay and zeolite dusts (exclusive of 1:1 layer silicates)  

Energy Technology Data Exchange (ETDEWEB)

Clays and zeolites are among the most important of natural dusts by virtue of their occurrence through out the world on the earth`s surface and their important industrial uses. (The 1:1 layer silicates, including the serpentine and kaolin minerals, are not addressed in this chapter.) This chapter provides basic information on a variety of important aspects of each mineral, including crystal structure diagrams of each and references to more detailed discussions. 110 refs., 20 figs.

1993-12-31

82

Engineering health and safety in coal mining  

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.

1986-01-01

83

Dust and waterfree technology for demolition works in nuclear environments and other sensitive areas  

International Nuclear Information System (INIS)

At the University of Karlsruhe experiments were carried out from 1997 to 1999 to get fundamentals of flow characteristics of pneumatic extracted materials. The results could be used to develop a concept for demolition suitable for extraction and removing high-density concrete. The concept fulfills all demands of a closed nuclear area, especially of dust abatement. (orig.)

84

Changes in the Lung Lipids of Rabbits and Guinea-pigs Exposed to the Inhalation of Silica Dust  

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

1960-01-01

85

Carcinogenesis of inhaled radio daughters with uranium ore dust in beagle dogs  

International Nuclear Information System (INIS)

Daily exposures of adult beagle dogs to inhaled radon daughters and to uranium ore dust for 4-1/2 to 6 yr have produced respiratory tract carcinomas, at similar cumulative working level months (WLM) of exposures to those which induced carcinomas in uranium miners. Biological data from the beagle-dog experiments can therefore be used for prediction of carcinogenic risk under changing exposure conditions in future uranium miners.

1977-05-01

86

NAME=\\  

Wastenet

...Elizabeth Springs - National Heritage - Queensland Elizabeth Springs forms part of the Springvale supergroup of springs that, with the exception of Elizabeth ... Springs, are largely extinct. The Elizabeth Springs complex extends over an area of approximately 400 by 500 metres. Elizabeth Springs forms ...part of the Springvale supergroup of springs that, with the exception of Elizabeth Springs, are largely extinct. The Elizabeth Springs complex ...au/heritage/places/national/elizabeth-springs/index.html Elizabeth Springs - National Heritage - Queensland Change text size Skip to content Heritage National heritage ...

87

[Pilot-plant testing for flue gas desulfurization and dust removal by activated coke].  

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

2006-05-01

88

The photophoretic sweeping of dust in transient protoplanetary disks  

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 late times, the edge reaches a stable equilibrium between inward drift and ...

2006-01-01

89

HST/ACS observations of shell galaxies: inner shells, shell colours and dust  

CERN Document Server

AIM:Learn more about the origin of shells and dust in early type galaxies. METHOD: V-I colours of shells and underlying galaxies are derived, using HST Advanced Camera for Surveys (ACS) data. A galaxy model is made locally in wedges and subtracted to determine shell profiles and colours. We applied Voronoi binning to our data to get smoothed colour maps of the galaxies. Comparison with N-body simulations from the literature gives more insight to the origin of the shell features. Shell positions and dust characteristics are inferred from model galaxy subtracted images. RESULT: The ACS images reveal shells well within the effective radius in some galaxies (at 1.7 kpc in the case of NGC 5982). In some cases, strong nuclear dust patches prevent detection of inner shells. Most shells have colours which are similar to the underlying galaxy. Some inner shells are redder than the galaxy. All six shell galaxies show out of dynamical ...

2007-01-01

90

Deforestation and avian extinction on tropical landbridge islands.  

Science.gov (United States)

There are few empirical data, particularly collected simultaneously from multiple sites, on extinctions resulting from human-driven land-use change. Southeast Asia has the highest deforestation rate in the world, but the resulting losses of biological diversity remain poorly documented. Between November 2006 and March 2008, we conducted bird surveys on six landbridge islands in Malaysia and Indonesia. These islands were surveyed previously for birds in the early 1900 s, when they were extensively forested. Our bird inventories of the islands were nearly complete, as indicated by sampling saturation curves and nonparametric true richness estimators. From zero (Pulau Malawali and Pulau Mantanani) to 15 (Pulau Bintan) diurnal resident landbird species were apparently extirpated since the early 1900 s. Adding comparable but published extinction data from Singapore to our regression analyses, we found there were proportionally fewer forest bird ...

2010-10-01

91

Properties of dust particles sampled from windboxes of an iron ore sintering plant: Surface structures of unburned carbon  

Energy Technology Data Exchange (ETDEWEB)

Aiming to understand the formation mechanism of dioxins in the iron ore sintering process, dust samples obtained from some windboxes of a commercial iron ore sintering plant have been characterized with a powder X-ray diffraction (XRD), by the transmission electron microscope (TEM) equipped with an electron energy loss spectroscopy (EELS), and by the temperature-programmed desorption (TPD) and temperature-programmed oxidation (TPO) techniques. The elemental and XRD analyses reveal that the content of the Cl present in the samples ranges from 0.075 mass%-dry to 5.1 mass%-dry and tends to be higher at smaller dust particles, and that some of the Cl exists as KCl with the average crystalline size between 40 nm and 50 nm. Dust samples also contain a significant amount of unburned carbon, and the smallest dust particles, < 500 {mu}m, show the highest C contents in many cases and consist partly of C, ...

2006-07-01

92

Development of materials resistant to metal dusting degradation.  

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 ...

2006-04-24

93

The X-ray Halo of G21.5-0.9  

CERN Document Server

The emission of the plerion G21.5-0.9 appears more extended in X rays than in radio. This is an unexpected result because it would imply that short-lived X-ray electrons may reach distances even larger than radio electrons. Applying an empirical relationship between dust scattering optical depth and photoelectric column density, the measured column density leads to a large optical depth at 1 keV, of about 1. Therefore we investigate the hypothesis that the detected halo be an effect of dust scattering, re-analyzing an Cal/PV XMM-Newton observation of G21.5-0.9 and critically examining it in terms of a dust scattering model. We also present a spectral analysis of a prominent extended feature in the northern sector of the halo.

2003-01-01

94

Safety designs for sludge ducts in brown coal briquetting plants  

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.

1987-06-01

95

Safe design of mud ditches in briquetting factories  

Energy Technology Data Exchange (ETDEWEB)

The authors study technological safety of installing a water spray pressure vessel between electrostatic deduster 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 m/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. (MOS).

1987-06-01

96

Observation of dust stream formation produced by low current, high voltage cathode spots  

International Nuclear Information System (INIS)

Macroparticle acceleration driven by low current, high voltage cathode spots has been investigated for potential applications ranging from micrometeoroid simulation to nanoparticle deposition/implantation. Acceleration by this process was observed to occur when nanometer and micrometer-sized particles were exposed to a high voltage pulse in the presence of a plasma discharge. The applied negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provide the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. Cathode spot behavior was also documented. The particle impact craters observed at the surface of downstream witness badges were documented using scanning electron microscopy and light microscopy. The observed impacts suggest the presence of energetic macroparticles formed during this process.

2004-04-01

97

Metal dusting behaviour of welded Ni-base alloys with different surface finish  

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.)

2003-10-01

98

In vitro evaluation of mineral cytotoxicity and inflammatory activity  

Energy Technology Data Exchange (ETDEWEB)

Health risks associated with inhalation of mineral dusts have been identified to a great extent through epidemiology studies, but also have been assessed by conducting subchronic and chronic inhalation studies typically on rodents. However, in vivo studies are softly, time-consuming, requiring complex technologies, and may not yield information on cellular and molecular mechanisms of response. As a result, the use of in vitro cell culture systems has played an important role in studying the toxicology of mineral dusts and providing insight into action mechanisms. This article reviews selected in vitro approaches that are used to investigate the cytotoxic and inflammatory properties of mineral particles and fibers. In addition key findings as they relate to understanding the toxicology of mineral dusts are presented. 165 refs., 1 fig., 5 tab.

1993-12-31

99

Design of a modern hot-blast cupola furnace  

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).

1990-01-01

100

Coal liquefaction catalysis by industrial metallic wastes  

Energy Technology Data Exchange (ETDEWEB)

Catalytic activity of industrial metallic wastes in coal liquefaction was examined in a 100lb/day continuous coal processing development unit. Red mud, a waste material from the aluminium industry, and an electric furnace flue dust containing Ni, Mo, Co and Fe showed a pronounced effect on the conversion of a Kentucky bituminous coal. Coal conversion and oil production increased significantly with the addition of red mud and flue dust. Comparison of the catalytic activity of pyrite, red mud, and flue dust, based on selectivity analysis, showed that red mud was the most desirable disposable catalyst. However, if the primary goal of coal liquefaction is high oil production, irrespective of hydrogen consumption, pyrite is the most active catalyst among those discussed in the paper.

1985-01-01

101

A novel approach to the dynamics of Szekeres dust models  

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 ...

2011-01-01

102

The cometary activity of Centaur P/2004 A1 (LONEOS)  

British Library Electronic Table of Contents (United Kingdom)

Abstract P/2004 A1 (LONEOS) is one of the few active objects in the dynamical class of Centaurs. It has been recently injected into an inner orbit with a perihelion distance-q-= 5.5 au. The aim of this paper is to characterize the dust coma of this peculiar object, 2.5 yr after its first -new- perihelion passage inside the Solar system. Broad-band visible images taken at the TNG telescope in 2007 February were analysed in order to characterize the dust coma of the Centaur: it was still quite active at-rh-= 6.5 au post-perihelion, with a coma and a well-developed wide tail-like structure, with a measured-R-Af= 162 10-cm in an aperture radius = 104 km. The (V---R) colour and the reddening values depict a scenario of a slightly red dust coma. A dust mass-loss rate of--= 133 kg-s-1 is derived ...

2011-01-01

103

Standardization of rules for manufacturing normal electrical equipment for mining  

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.

1983-01-01

104

Observations of late-type young stars in the Rho Oph dark cloud  

Energy Technology Data Exchange (ETDEWEB)

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

1980-04-01

105

Intergalactic dust and its photoelectric heating  

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 ...

2008-01-01

106

IgE antibodies to D. pteronyssinus in atopic patients.  

UK PubMed Central (United Kingdom)

An aqueous house dust mite extract was separated by SDS-PAGE and transferred to nitrocellulose membranes by Western Blotting. Two major allergens, Der pI and Der pII associated with the mite faeces...Full Text Available

1988-06-01

107

Exposure of cotton workers in an experimental cardroom with reference to airborne endotoxins.  

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

1986-04-01

108

Development of a Coke-Free Cupola Furnace. Energy Conserving Shaft Furnace for Iron Materials. Final Report.  

Science.gov (United States)

Coke-fired cupola furnaces were improved and made suitable for the production of high-quality casting melts by numerous additional devices. Moreover, they were equipped with environmental protection systems with numerous dust separation devices and afterb...

1986-01-01

109

Deaths and tumours among workers grinding stainless steel: a follow up.  

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

1997-11-01

110

APOD: 2011 January 25 - The Rippled Red Ribbons of SNR 0509  

Science.gov (United States)

blast should have passed the Earth? Like: Follow APOD on Facebook Tomorrow's picture: whirlpool dust < | Archive | Index | Search | Calendar | RSS | Education | About APOD |...

2011-10-07

111

Tidd experience prepares hot gas cleaning technology for commercialization  

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.

1995-09-01

112

Thermal treatment of dusts from non ferrous metallurgical industries  

Energy Technology Data Exchange (ETDEWEB)

Three samples of dusts generated by the non ferrous metallurgical industries are treated between 200 and 800 degree centigree in controlled oxidizing and reducing atmospheres. The objective of this study is to recover the valuable metals from these wastes. The treatments of these solids under oxidizing conditions at 700 degree centigree are well adapted for two samples. The totality of valuable elements are concentrated in the treatments residues. The use of hydrogen at 600 degree centigree, permits the removal of up to 100 % of valuable metals contained in the treated industrial wastes. The recovery rate of valuable metals (Pb, Zn, Cu) as well as the Global Decontamination Factor are reported. (Author) 9 refs.

2000-07-01

113

Metastable carbon in two chondritic porous interplanetary dust particles  

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).

114

Kinetics of reduction of iron oxides using microwaves as power source  

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.

1996-12-31

115

Asbestos: Industrial applications and precautions. (Latest citations from Information Services in Mechanical Engineering data base). Published Search  

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations concerning the properties, industrial uses and federal regulation of asbestos. The references explore advantages and disadvantages associated with use of industrial robots in areas containing high concentrations of asbestos dust, the use of water as a cutting tool to control the generation of asbestos dust, and governmental policies and attitudes relative to the health and welfare of workers subjected to asbestos. Thermal insulation properties, wear characteristics, high temperature capabilities, use as a reinforcement in composite materials, and asbestos substitutes are included. (Contains a minimum of 69 citations and includes a subject term index and title list.)

1992-07-01

116

A multi-wavelength scattered light analysis of the dust grain population in the GG Tau circumbinary ring  

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 ...

2004-02-04

117

Molar extinction coefficients of some carbohydrates in aqueous solutions  

Science.gov (United States)

Molar extinction coefficients of some carbohydrates viz. L-arabinose (C5H10O5), D-glucose (C6H12O6), D-mannose (C6H12O6), D-galactose (C6H12O6), D(-) fructose (C6H12O6) and maltose (C12H24O12) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by gamma ray transmission method in a narrow beam good geometry set-up. These coefficients have been found to depend upon the photon energy following a 4-parameter polynomial. These extinction coefficients for different sugars having the same molecular formula have same values varying within experimental uncertainty. Within concentration ranges studied, Beer--Lambert law is obeyed very well.

2002-03-01

118

IRON (III) MOLAR EXTINCTION COEFFICIENTS IN LIGHT AND HEAVY WATER SOLUTIONS  

Science.gov (United States)

The iron(III) molar extinction coefficient in H/sub 2/O-0.4 M H/sub 2/SO/ sub 4/ solution at maximum absorption and 25 deg C, epsilon /sub s/, was determined to be 2220 plus or minus 20 liters mole/sup -1/ cm/sup -1/. The ratio of the iron(III) molar extinction coefficient in D/sub 2/O-0.4 M H/sub 2/SO/ sub 4/ solution at maximum absorption and 25 deg C to epsilon /sub s/ was found to be 1.068 P 0.004. The acidity effect is presented graphically, since the effect is nonlinear. The temperature coefficients were determined to be +(0.63 plus or minus 0.02)% per de gree centigrade for light water solutions and +(0.36 plus or minus 0.02)% per degree centigrade for heavy water solutions. (auth)

1962-04-01

119

Wind tunnel tests of biodegradable fugitive dust suppressants being considered to reduce soil erosion by wind at radioactive waste construction sites  

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 ...

1993-01-01

120

Investigation of techniques to improve continuous air monitors under conditions of high dust loading in environmental setting. 1998 annual progress report  

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 combination of resolution and throughput is obtained with 3.0 \\265m Millipore fluoropore and 1.0 \\265m Corning FNMB filters. ...

1998-06-01

121

3D Time-Dependent Model Of The Dusty-Gas Atmosphere Of Comet 67P/Churyumov-Gerasimenko: Recent Improvements.  

Science.gov (United States)

Under support from the French Space Agency (CNES), a 3D+t dusty-gas model of Comet 67P/Churyumov-Gerasimenko is being developed, to compute, from the first 2014 Rosetta orbital data, the aerodynamic forces exerted on the Rosetta orbiter and on the descent lander. We report the recently developed dust dynamics part of the code. The multi-species (presently H2O and CO) gas code is optimized in terms of computational speed owing to the use of two complementary methods: (a) 3D+t Direct Simulation Monte Carlo (DSMC) runs in the non-equilibrium regions adjacent to the surface and very distant from it, and (b) solutions of the Navier-Stokes equations in-between. The model is used presently using Lamy et al. (Space Sci. Rev., 2007, 128, 23) coarse information on 67P nucleus shape and rotation, and a range of possible gas production rates Q for the early Rosetta observations at rh 3 AU (Q 1026 - 1027 s-1). In the interim version, simplifying assumptions are made with ...

2010-10-01

122

Environmental Synergisms and Extinctions of Tropical Species  

British Library Electronic Table of Contents (United Kingdom)

Abstract: Environmental synergisms may pose the greatest threat to tropical biodiversity. Using recently updated data sets from the International Union for Conservation of Nature (IUCN) Red List, we evaluated the incidence of perceived threats to all known mammal, bird, and amphibian species in tropical forests. Vulnerable, endangered, and extinct species were collectively far more likely to be imperiled by combinations of threats than expected by chance. Among 45 possible pairwise combinations of 10 different threats, 69%, 93%, and 71% were significantly more frequent than expected for threatened mammals, birds, and amphibians, respectively, even with a stringent Bonferroni-corrected probability value (p= 0.003). Based on this analysis, we identified five key environmental synergisms in t...

2009-01-01

123

Effect of pressure on iodine complexes, 1  

International Nuclear Information System (INIS)

Absorption spectra of the visible I_2 band of I_2 complexes with Et_2O, Et_2S, and Et_2Se in heptane have been measured up to 3300 bar at 25"0C. The equilibrium constants and volume changes accompanying complex formation, the molar extinction coefficients and the absorption maxima have been estimated. The volume changes were found comparable with those estimated from the X-ray data of the I_2 complexes in the crystalline state. The enhancement of the molar extinction coefficient and the blue shift of the visible I_2 band with increasing pressure have been established. The results suggest a decrease in the bond distance between an n-donor and I_2, compared with the spectroscopic properties of the I_2 complex at 1 bar. The decrease has been estimated as 0.008 nm with increasing pressure up to 3300 bar. (author).

1979-01-01

124

Determination of molar extinction coefficients #epsilon#_m(Ce"4"+) of Ce"4"+-Ce"3"+ dosimetric system  

International Nuclear Information System (INIS)

#epsilon#_m(Ce"4"+) values of the ceric-cereus system have been measured and the experimental procedure is described. Both routine titration method and electrochemical measurement were used. Some interference factors, such as ultraviolet, acidity and temperature, were studied as well. The temperature coefficient of #epsilon#_m(Ce"4"+) value in this experiment is about -0.1% degree C"-"1. A statistic analysis was made for 24 experimental values of #epsilon#_m(Ce"4"+) and a Gaussian distribution was found. Ultimately, an average molar extinction coefficient of 553.2 +- 1.3 m"2#centre dot#mol"-"1 was obtained at #approx#320 nm in 0.4 mol/L H_2SO_4 system, with a relative standard deviation of 0.24% (95% confidence level) and a total uncertainty of 1.5%.

1996-01-01

125

Analysis of the dynamics of coal char combustion with ignition and extinction phenomena: Shrinking core model  

Energy Technology Data Exchange (ETDEWEB)

Single-particle combustion of coal char is analyzed using a generalized shrinking core model. Finite volume method, which was earlier employed by the authors in solving moving boundary problems involving fluid-solid noncatalytic reactions in general, is used to solve fully transient mass and energy equations. The model takes into account convection and diffusion inside the particle as well as in the boundary layer. The computed results are compared with the experimental data of the authors for combustion of coal char in a fluidized bed combustor. The effects of parameters such as bulk temperature and initial particle radius on the combustion dynamics are examined. The phenomena of ignition and extinction are also investigated. Finally, the importance of Stefan flow, originating due to nonequimolar counterdiffusion, on combustion of coal char is analyzed.

2008-09-15

126

A Preliminary Investigation of the Reinforcement Function of Signal Detections in Simulated Baggage Screening: Further Support for the Vigilance Reinforcement Hypothesis  

Science.gov (United States)

The vigilance reinforcement hypothesis (VRH) asserts that errors in signal detection tasks are partially explained by operant reinforcement and extinction processes. VRH predictions were tested with a computerized baggage screening task. Our experiment evaluated the effects of signal schedule (extinction vs. variable interval 6 min) and visual field complexity (dial vs. baggage x-ray) on search behavior rates. There was a main effect for signal schedule [F (1, 20) = 14.0, p = 0.001, p[subscript rep] = 0.99], but no effects for field complexity or interaction. The VRH suggests that performance errors in visual screening work may be reduced through operant conditioning of search behaviors by intensive management of artificially planted signals. (Contains 1 table and 3 figures.)

2008-12-01

127

Transformation of the Bioshpere: Deforestation  

Science.gov (United States)

Ts presentation, available online as a printable PDF, discusses the global effects of deforestation. It contains the following three pages:an overview of the reasons people have cut forests and how the direct destruction of forests is the primary reason for today's massive extinction of speciesa world map that shows the global forest cover 8,000 years agoa world map that shows the significantly smaller remaining frontier forests as of 1997?intact natural forest ecosystems that are relatively undisturbed and large enough to maintain all of their biodiversity.

128

Electrochemical oxidation of curium(III) in potassium carbonate solution  

International Nuclear Information System (INIS)

During electrolysis of a "2"4"8Cm(III) solution in 2M K_2CO_3 at pH=13, partial oxidation of curium to a higher oxidation state, probably Cm(IV), was observed. The absorption spectra of Cm(III) and Cm(IV) in K_2CO_3 solution were recorded and the molar extinction coefficients of main absorption bands of curium were evaluated. (author).

1986-11-01

129

Aerosol Physical, Optical and Chemical Properties during African Dust Events at Cape San Juan (CPR)  

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 determine volume size distributions and aerosol optical thickness, and a 3-wavelength ...

2008-12-01

130

Stellar and Dust Properties of Local Elliptical Galaxies: Clues to the Onset of Nuclear Activity  

CERN Document Server

We study the stellar and dust properties of a well-defined sample of local elliptical galaxies to investigate the relationship between host galaxy properties and nuclear activity. We select a complete sample of 45 ellipticals from the Palomar spectroscopic survey of nearby galaxies, which includes 20 low-luminosity active galactic nuclei classified as LINERs and 25 inactive galaxies. Using a stellar population synthesis method, we compare the derived stellar population properties of the LINER versus the inactive subsamples. We also study the dust and stellar surface brightness distributions of the central regions of these galaxies using high-resolution images obtained with the {\\it Hubble Space Telescope}. Relative to the inactive subsample, ellipticals hosting LINERs share similar total optical and near-infrared luminosity, central stellar velocity dispersions, and nuclear stellar populations as judged from their luminosity-weighted ages and ...

2008-01-01

131

Standards for limits of air pollutant emission in the GDR  

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 ...

1986-01-01

132

Management of storage rot in onion through gamma irradiation and chemicals  

International Nuclear Information System (INIS)

Pre-harvest sprays of bavistin (50% carbendazim) at 100, 200 and 400 g a.i/ha were ineffective in the control of Aspergillus niger van Tieghem in onion. The combination of gamma irradiation (0.1 kGy) with bavistin dust (0.33g a.i/kg bulbs) was effective to an extent of about 79% in reducing storage losses due to sprouting and rottage. This combination treatment was better than dust treatment alone and highly cost effective. Bavistin, when used as pre-harvest spray, did not leave any residue in the tissues, whereas the compound was seen to move deep into the tissues, when used as post-harvest dust treatment. Higher concentrations of carbendazim residues (2.1-3.4 mg/kg bulb) were detected in the outer scales of the bulbs, as compared to that of inner scales (0.6-1.6 mg/kg), and the residue decreased slightly with passage of storage time. (author). 19 refs., 2 tabs.

133

Injection of recyclable byproducts into a cupola furnace via natural gas/O{sub 2} burners; Einblasen von wiederverwertbaren Reststoffen ueber Erdgas/O{sub 2}-Brenner in einen Kupolofen  

Energy Technology Data Exchange (ETDEWEB)

Disposal of fine-particled byproducts via injection into a capola furnace using natural gas/O{sub 2} burners is a cost-efficient alternative to landfill dumping. Tests conducted in a foundry demonstrated that dusts collected there can be injected without detriment to melt-down rate and iron quality. The replacement of FeSi pellets with FeSi dust in addition reduced the slag content, while injection of coal dust permitted a decrease in coke consumption. (orig.) [Deutsch] Die Entsorgung von feinkoernigen Reststoffen durch Einblasen in einen Kupolofen ueber Erdgas/O{sub 2}-Brenner ist eine wirtschaftliche Alternative zur Deponierung. Anhand von Versuchen in einer Giesserei konnte aufgezeigt werden, dass hier anfallende Staeube ohne nachteilige Auswirkungen auf Schmelzleistung und Eisenqualitaet einzublasen sind. Die Substitution von FeSi-Formlingen durch FeSi-Staub brachte zudem eine Reduzierung des Schlackeanteils und das ...

1997-07-01

134

H_2 emission arises outside photodissociation regions in ultra-luminous infrared galaxies  

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 ...

2010-01-01

135

Episodic mass loss in binary evolution to the Wolf-Rayet phase: Keck and HST proper motions of RY Scuti's nebula  

CERN Document Server

Binary mass transfer via Roche-lobe overflow (RLOF) is a key channel for producing stripped-envelope Wolf-Rayet (WR) stars and may be critical to account for SN Ib/c progenitors. RY Scuti is an extremely rare example of a massive binary star caught in this brief but important phase. Its toroidal nebula indicates equatorial mass loss during RLOF, while the mass-gaining star is apparently embedded in an opaque accretion disk. RY Scuti's toroidal nebula has two components: an inner ionised double-ring system, and an outer dust torus that is twice the size of the ionised rings. We present two epochs of Lband Keck NGS-AO images of the dust torus, plus three epochs of HST images of the ionised gas rings. Proper motions show that the inner ionised rings and the outer dust torus came from two separate ejection events roughly 130 and 250 yr ago. This suggests that RLOF in massive contact binaries can be accompanied by eruptive and ...

2011-01-01

136

Combined Scanning Electron Microscope and Micro-InfraRed measurements on Interplanetary Dust Particles  

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 "olivines" and "pyroxenes" and one belongs to the ...

2007-01-01

137

Briquetting of self-reducing blendings of waste iron oxide mixtures. Final report  

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 ...

2002-07-01

138

Analysis of exhaust gas visibility in iron ore sintering plant  

Energy Technology Data Exchange (ETDEWEB)

Visible smoke of exhaust gas from iron ore sintering plants spoil the scenery around the works. In this paper, the mechanism of formation of visible smoke is discussed by detailed analysis of the exhaust gas components and dust in the Oita No. 1 sintering plant. The main substance of visible smoke was mist condensing in the air during the cooling of exhaust gas that contained 0.1 ppm of sulfuric acid. Sulfuric acid is considered to raise the dew point and so facilitate mist condensation, and to lower the vaporization of visible mist containing sulfuric acid solution. Dust in the exhaust gas is also considered to act as nucleation sites for mist condensation. This proposed mechanism was confirmed by the test remixing SOx-rich gas with desulfurization gas in the Nagoya No. 3 sintering plant. Long trails of visible smoke were observed by remixing SOx-rich gas with exhaust gas. In conclusion, in order to make exhaust gas invisible, it is not ...

2006-07-01

139

RADIAL DISTRIBUTION OF STARS, GAS AND DUST IN SINGS GALAXIES. I. SURFACE PHOTOMETRY AND MORPHOLOGY  

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 ...

2009-10-01

140

Tar removal with a wet ElectroStatic Precipitator (ESP). A parametric study  

Energy Technology Data Exchange (ETDEWEB)

The ElectroStatic Precipitator (ESP) removes dust and tar droplets very efficiently from biomass product gas. Dust was removed for more than 99%. The tar dewpoint was reduced from 130C to 21C, which is sufficient for the application of the product gas in a gas engine. Tar removal is not sensitive to the voltage or fluctuations in the gas residence time . The voltage was varied between 28 to 37 kV{sub arith} and the gas residence time between 4 and 11s. Fouling of the ESP collector plates was negligible, which was concluded from visual inspection after 200 hours of operation. A reduction in the residence time reduces the size of the ESP and has a significant impact on the investment costs of the ESP. Keywords: electrostatic filter, tar removal, circulating fluidised bed (CFB)

2004-05-01

141

Problematic of atmospheric pollution in Lebanon: the better stake is apprehended, the best acts are taken  

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.

142

In-depth survey report of Scoular Elevator, Salina, Kansas  

Science.gov (United States)

An in/depth industrial hygiene survey of exposures to phosphine during the use of aluminum phosphide was conducted as part of a survey on exposure to grain fumigants. Area monitoring and breathing-zone sampling for phosphine were conducted during the addition of aluminum phosphide to grain during turning operations; source samples and peak personal exposures were also analyzed. Major sources of personal exposure included the escape of air from the bin headspace during filling with treated grain, filling and emptying of the phosphide pellet dispenser, and infiltration from the treated grain bin and from the pellet dispenser itself into adjacent air space. Relatively good dust control was indicated by the total dust samples collected during the survey. Measures recommended by the author are in the report.

1987-06-01

143

Homoclinic chaos and energy condition violation  

International Nuclear Information System (INIS)

In this letter we discuss the connection between so-called homoclinic chaos and the violation of energy conditions in locally rotationally symmetric Bianchi type IX models, where the matter is assumed to be nontilted dust and a positive cosmological constant. We show that homoclinic chaos in these models is an artifact of unphysical assumptions: it requires that there exist solutions with positive matter energy density #rho#>0 that evolve through the singularity and beyond as solutions with negative matter energy density #rho#<0. Homoclinic chaos is absent when it is assumed that the dust particles always retain their positive mass. In addition, we discuss more general models: for solutions that are not locally rotationally symmetric we demonstrate that the construction of extensions through the singularity, which is required for homoclinic chaos, is not possible in general.

2006-09-15

144

Properly synchronized measurements of droplet sizes for high-pressure intermittent coal-water slurry fuel sprays  

Energy Technology Data Exchange (ETDEWEB)

Experiments were completed to study intermittent coal-water slurry (CWS) fuel sprays injected from an electronically-controlled accumulator injector system. A new synchronization technique was developed using the light extinction signal as a triggering source for the data taking initiation with a laser diffraction particle analyzing (LDPA) technique. This technique allowed measurement of SMDs near the spray tip where the light extinction was low and the data were free from the multiscattering bias. Coal-water slurry fuel with 50% coal loading in mass containing 5 {mu}m mass median diameter coal particulates was considered. A correlation of the SMD with the injection conditions was determined which should show a satisfactory agreement with the measured SMD data. The spray SMD showed an increase with the distance of the axial measurement location and with the ambient gas density, and showed a decrease with increasing injection pressure.

1993-12-31

145

Molar extinction coefficients of some fatty acids  

International Nuclear Information System (INIS)

The attenuation of gamma rays in some fatty acids, viz. formic acid (CH_2O_2), acetic acid (C_2H_4O_2), propionic acid (C_3H_6O_2), butyric acid (C_4H_8O_2), n-hexanoic acid (C_6H_1_2O_2), n-caprylic acid (C_8H_1_6O_2), lauric acid (C_1_2H_2_4O_2), myristic acid (C_1_4H_2_8O_2), palmitic acid (C_1_6H_3_2O_2), oleic acid (C_1_8H_3_4O_2) and stearic acid (C_1_8H_3_6O_2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement between experiment and theory.

2002-10-01

146

Molar extinction coefficients of some commonly used solvents  

International Nuclear Information System (INIS)

Molar extinction coefficients of some commonly used solvents (ethanol (C_2H_5OH), methanol (CH_3OH), propanol (C_3H_7OH), butanol (C_4H_9OH), water (H_2O), toluene (C_7H_8), benzene (C_6H_6), carbontetrachloride (CCl_4), acetonitrile (C_4H_3N), chlorobenzene (C_6H_5Cl), diethylether (C_4H_1O) and dioxane (C_4H_8O_2)) have been determined by a well-collimated narrow beam transmission geometry at 279, 356, 662, 1173, 1252 and 1332 keV #gamma# rays. The total #gamma# ray interaction cross sections of these solvents have also been determined. A good agreement has been obtained between the experimental results with the theoretical values evaluated through XCOM calculations.

2006-07-01

147

Molar extinction coefficients in aqueous solutions of some amino acids  

International Nuclear Information System (INIS)

Mass attenuation coefficients of amino acids viz. glycerine (C_2H_5NO_2), 1-Serine (C_3H_7NO_3), 1-Theronine (C_4H_9NO_3), 1-Proline (C_5H_9NO_2), 1-Valine (C_5H_1_1NO_2) and 1-Phenylalanine (C_9H_1_1NO_2) in aqueous solutions have been determined at 81, 356, 511, 662, 1173 and 1332 keV by the gamma-ray transmission method in a narrow beam good geometry setup. Precisely measured densities of these solutions were used for the determination of these coefficients which varied systematically with the corresponding changes in the concentrations (g/cm"3) of the solutions. Molar extinction coefficients of amino acids were then obtained at these energies and were found to be in good agreement with the theoretical results. In addition, total interaction cross sections of amino acids in aqueous solutions were also calculated. (author)

2002-09-01

148

Effect of pressure on iodine complexes, 2  

International Nuclear Information System (INIS)

Absorption spectra of the CT bands of I_2 complexes with Et_2O, Et_2S, and Et_2Se in heptane have been measured up to 4400 bar at 25"0C. The equilibrium constants and the volume changes accompanying complex formation, and the molar extinction coefficients and absorption maxima have been estimated. The volume changes were comparable with those estimated by the visible I_2 bands and by the X-ray data of the I_2 complexes in the crystalline state. In the CT bands of Et_2S-I_2 and Et_2Se-I_2 complexes inversion of shift from red to blue has been observed with increasing pressure though the CT band of Et_2O-I_2 complex shifted only through red. This inversion appears to be characteristic of the strong CT complex. Enhancement of the molar extinction coefficient of the CT band has been found with increasing pressure suggesting enhancement of the CT interaction between I_2 and the n-donor. (author).

1979-01-01

149

Bifurcation and complex dynamics of a two-prey two-predator system concerning periodic biological and chemical control  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we investigate the dynamic behaviors of a two-prey two-predator system with impulsive effect concerning biological and chemical control strategy-periodic releasing natural enemies and spraying pesticide at different fixed time. By applying the Floquet theory of linear periodic impulsive equation and small amplitude perturbation method, we prove that there exists a globally asymptotically stable two-prey-eradication periodic solution when the impulsive period is less than some critical value. The conditions for the permanence of the system are given, and meanwhile the conditions for the extinction of one of the two prey species and permanence of the remaining three species are given. Our results suggest a new approach in pest control. The target pest population can be driven to extinction and the non-target pest can be permanent by choosing impulsive period. With the increasing of the predation rate for the super competitor and ...

2008-07-15

150

Waterjet-assisted cutting nears commercialization  

Energy Technology Data Exchange (ETDEWEB)

Water-assisted mining machinery is beginning to be considered in the US, although it has been in use in Europe for some time. A waterjet roof bolter is currently under test and should greatly increase drilling rate with longer bit life and no dust. Water-assisted roadheaders and longwall winning machines under development in Europe and the US are described.

1984-12-01

151

The method for iron removal from cadmium in the course of refining process; Sposob usuwania zelaza z kadmu w procesie jego rafinacji  

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.

1992-10-30

152

The chemical properties of silica particle surface in relation to silica-cell interactions  

Energy Technology Data Exchange (ETDEWEB)

Although silicosis has been studied extensively, the mechanism is still not fully understood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are though to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.

1989-01-01

153

Surface photometry and the structure of elliptical galaxies  

International Nuclear Information System (INIS)

Surface photometry of bulges and elliptical galaxies is reviewed. The properties of cores and nuclei as revealed by improvements in seeing and the use of CCDs are examined, and newly discovered structural details such as dust, shells, and dynamical subsystems which show the importance of accretion events in galactic evolution are addressed. Improved constraints on galaxy formation resulting from better measurements of parameter scaling laws are discussed, and accurate measurements of departures from elliptical isophotes and of color gradients obtained with CCDs are considered.

154

Silica, silicosis and tuberculosis.  

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 ...

2007-05-01

155

Shale oil explosives  

Energy Technology Data Exchange (ETDEWEB)

Ammonium nitrate shale oil explosives are provided which are effective, powerful, inexpensive, and safe. The explosives contain about 2% to 10% by weight shale oil and about 90% to 98% by weight ammonium nitrate. The shale oil can be whole shale oil or heavy shale oil containing from 0.1% to 65% by weight oil shale dust. The ammonium nitrate is preferably in the form of explosive grade ammonium nitrate prills.

1984-10-09

156

Polycyclic aromatic hydrocarbon emission profiles and removal efficiency by electrostatic precipitator and wetfine scrubber in an iron ore sintering plant  

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}, ...

2008-11-15

157

Metabolomics in Lung Inflammation: A High Resolution 1H NMR Study of Mice Exposed to Silica Dust  

UK PubMed Central (United Kingdom)

Here we report the first 1H NMR metabolomics studies on excised lungs and bronchoalveolar lavage fluid (BALF) from mice exposed to crystalline silica. High resolution 1H...Full Text Available

2008-01-01

158

ELECTRON MICROSCOPE PREPARATIONS OF RADIOACTIVELY LABELED AEROSOLS  

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)

1963-04-01

159

An Investigation of the Coastal Circulations and Aerosol Transport in the Arabian Gulf region during Unified Aerosol Experiment (2004)  

Science.gov (United States)

An observational and modeling study was performed over the Arabian Gulf region to investigate the coastal circulations and aerosol transport in the area. Climatological data and observations from the United Arab Emirates' Unified Aerosol Experiment were used to develop a better understanding of the complex meteorological processes in the Arabian Gulf region. Climatological data suggests that sea breezes occur on more than 77 percent of days in all months of the year and land breezes occur on more than 70 percent of the days. The occurrence of the sea and land breeze circulations are higher (90-99 percent) during the summer months when large-scale weather patterns are quiescent. Measurements of aerosol concentrations taken during the Unified Aerosol Experiment(2004) experiment are used to investigate aerosols, namely dust, transported in the Arabian Gulf region. Vertical profiles of dust concentration along with vertical profiles of potential ...

2005-12-01

160

An ADP proposal to study the formation and evolution of dust-embedded clusters. Final report  

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.

161

APERTURE SYNTHESIS IMAGING OF V892 Tau AND PV Cep: DISK EVOLUTION  

International Nuclear Information System (INIS)

I present a study of two Herbig Ae stars that are in completely different evolutionary stages: V892 Tau and PV Cep. Using sub-arcsecond interferometric observations obtained with the Combined Array for Research in Millimeter-wave Astronomy at #lambda# = 1.3 and 2.7 mm, I have for the first time resolved their disks. I deduce that the 5 Myr old V892 Tau has a low dust opacity index #beta# = 1.1 and a disk mass of #approx#0.03 M_s_u_n. These values correspond to the growth of its dust into large, up to centimeters size, structures. In contrast, the very young (a few x10"5 yr) PV Cep has a quite high opacity index #beta# = 1.75 and a more massive disk 0.8 M_s_u_n. PV Cep has the youngest resolved disk around any Herbig Ae star. Unlike the youngest T Tauri and Class 0 stars, which contain large and processed grains, the young Herbig Ae star, PV Cep, disk contains interstellar-medium-like unprocessed dust. This suggests that PV ...

2010-10-10

162

Refractometry of organosilica microspheres  

CERN Document Server

The refractive index of novel organosilica (nano/micro)material is determined using two methods. The first method is based on analysis of optical extinction efficiency of organosilica beads versus wavelength, which is obtained by a standard laboratory spectrometer. The second method relies on the measurable trapping potential of these beads in the focused light beam (laser tweezers). Polystyrene beads were used to test these methods, and the determined dispersion curves of refractive index values have been found accurate. The refractive index of organosilica beads has been determined to range from 1.60-1.51 over the wavelength range of 300-1100 nm.

2007-01-01

163

One-electron oxidation of photosynthetic pigments in micelles. Bacteriochlorophyll a, chlorophyll a, chlorophyll b, and pheophytin a  

International Nuclear Information System (INIS)

Chlorophyll a, chlorophyll b, and bacteriochlorophyll a in aqueous micellar solutions of Trition X 100 (2%) are readily oxidized by pulse-radiolytically generated N_3., Br_2"-., and (SCN)_2"-. radicals at nearly diffusion-controlled rates. The kinetic study suggests that pigment molecules occupy multiple sites in the micelle. Pheophytin a is only oxidized by N_3. and Br_2"-. radicals. The absolute spectra and the molar extinction coefficients of chlorophyll a, bacteriochlorophyll a, chlorophyll b, and pheophytin a cations have been determined. The chlorophyll a cation has been observed in the presence of pigment aggregates.

1981-11-01

164

Manifestation of isotope effects in absorption spectra of "1"4"4Sm"3"+ and "1"5"4Sm"3"+ in solutions  

International Nuclear Information System (INIS)

Photoluminescence spectra for solutions containing Sm"3"+ isotope ions in heavy and normal water were studied in the wave length #lambda# = 500-700 nm and for absorption spectra and photoluminescence excitation spectra within the range of #lambda# = 260-600 nm. Differences in molar extinction coefficients for "1"4"4Sm"3"+ and "1"5"4Sm"3"+ were established both in the solutions with D_2O and by transition from the solutions with D_2O to the solutions with H_2O. New possible causes of the identified effects are discussed

1998-01-01

165

Investigations of electronic transitions and photodissociation of the bromine molecule  

Science.gov (United States)

The electronic transitions and photodissociation of the bromine molecule were studied in the visible-near UV continuum using dynamic simulation. The molar extinction coefficients in this study were obtained in numerical calculations. The quantum yields of the spin-orbit Br*(2 P 1/2) product at different photon frequencies were determined. Time-dependent density functional theory was used to analyze the highest five occupied and lowest five unoccupied Br2 orbitals. The transition to the 1? u state was found to be most probable in the visible-near UV absorption range.

2008-12-01

166

Investigation of formation of Sn-PM tetracycline and Sn-PM-tetracycline-_9_9Tc complexes  

International Nuclear Information System (INIS)

The formation and stability constants of the [sup(99m)Tc]PM tetracycline have been investigated by the potentiometric method. The pK value of the complex formed was measured as pK = 5.49 +- 0.19. The spectrophotometric study has been performed on the formation of a complex of Sn(II) and TcO"4"- in the presence of PM Tetracycline. This study shows that Sn(II) forms with PMT a complex at a mole ratio of 1:1. The molar extinction coefficients of the Sn-PMT and [_9_9Tc]PMT complexes have been measured. (author).

1983-01-01

167

Emittance theory for thin film selective emitter  

Energy Technology Data Exchange (ETDEWEB)

Thin films of high temperature garnet materials such as yttrium aluminum garnet (YAG) doped with rare earths are currently being investigated as selective emitters. This paper presents a radiative transfer analysis of the thin film emitter. From this analysis the emitter efficiency and power density are calculated. Results based on measured extinction coefficients for erbium-YAG and holmium-YAG are presented. These results indicated that emitter efficiencies of 50 percent and power densities of several watts/sq cm are attainable at moderate temperatures (less than 1750 K).

1994-08-01

168

Electrochemical and spectroelectrochemical studies on Bis(acetylacetonate)(dimethyl sulfoxide) dioxouranium(VI) in dimethyl sulfoxide  

International Nuclear Information System (INIS)

The mechanistic aspects of electrochemical reductions of U"V"IO_2(acac)_2dmso(acac=acetylacetonate, dmso=dimethyl sulfoxide) complex with bidentate ligand(acac) in DMSO were investigated by using cyclic voltammetry, normal pulse voltammetry, and spectrophotometer equipped with an optical transparent thin layer electrode cell. It is concluded that the uranyl complexes with bidentate ligands at the equatorial plane form stable U(V) complexes by the electrochemical reduction and that their molar extinction coefficients in the visible region are very small. (J.P.N.).

1996-01-01

169

Aluminium, gallium and indium complexing with methylthymol blue  

International Nuclear Information System (INIS)

Al, Ga and In complexing with methylthymol blue (H_6R) purified by gel filtration is studied. in the case of metal excess complexes with the ratio of components M:H_6R=2:1 with #lambda#=587(Al), 590(Ga) and 593 nm(In) appear. In the case of reacting agent excess complexes with the ratio of component 1:1 with #lambda#_m_a_x=480-490 (Al) and 480 nm(Ga, In) appear. The mechanism of complexing reactions is studied. Molar extinction coefficients and stability constants are calculated.

1988-01-01

170

Discrepancies in molar extinction coefficients of Fe"3"+ in Fricke dosimetry  

International Nuclear Information System (INIS)

Values of the chemical yield, G, and of the molar extinction coefficient, epsilon, for Fricke dosimetry, have been recommended by ICRU. For epsilon, the value in ICRU Reports 17 and 21, 2205 1.mol"-"1.cm"-"1, based on an analysis of 83 reported values. It was suggested that, where neither a careful wavelength calibration nor absorbance linearity checks had been performed, a standard error of 1.5% should be assumed; otherwise 0.15% could be accepted. Alternatively, the accuracy in applying this chemical dose meter was considered improved if there was an independent determination of epsilon with the same spectrophotometer as was used for the determination of the optical density of irradiated Fricke solution. The accuracy claimed for both methods remains questionable, since no complete argumentation could be given for the differences of up to 13% in the published values. Taking into account the discussion of the sources of error by Bryant, Broszkiewicz and Ellis, we ...

1977-12-09

171

Correlated variations and periodicity of global CO{sub 2}, biological mass extinctions and extra-terrestrial bolide impacts over the past 250 million years and possible geodynamical implications  

Energy Technology Data Exchange (ETDEWEB)

Earth`s history has been witness to recurrently alternating phases of catastrophic evolution and dominant tectonic deformations, contractions and extension of rifting and spreading leading to quasi-cyclic changes in sedimentary environment and various earth processes. Recent studies have shown quasi-periodicities of 32{+-}2 Million years (Myr) in various endogenic (geomagnetic reversals, magmatic events, mantle convection, various tectonic activities, climate change and biological extinctions) and exogenic (impact catering) processes indicating a remarkable kinship. A time series analysis is presented of the available CO{sub 2} record over the past 250 Myr decoded from global CaCO{sub 3} accumulation rates in sedimentary environment. The time series analysis reveals an intriguing evidence of a dominant periodicity of 33{+-}2 Myr which matches closely with a `common catastrophic periodicity` of 32 Myr identified in various terrestrial and extra-terrestrial records. ...

1998-12-31

172

Absorption of 308-nm excimer laser radiation by balanced salt solution, sodium hyaluronate, and human cadaver eyes  

Energy Technology Data Exchange (ETDEWEB)

Absorption of the excimer laser radiations of 193-nm argon fluorine and 308-nm xenon chloride in balanced salt solution, sodium hyaluronate, and human cadaver eyes was measured. The absorption of these materials as considerably different for the two wavelengths; we found that 308-nm light experienced much less absorption than the 193-nm light. The extinction coefficient (k) for 308 nm was k = 0.19/cm for balanced salt solution and k = 0.22/cm for sodium hyaluronate. In contrast to this, the extinction coefficient for 193 nm was k = 140/cm for balanced salt solution and k = 540/cm for sodium hyaluronate. Two 1-day-old human phakic cadaver eyes showed complete absorption with both wavelengths. Using aphakic eyes, incomplete absorption was noted at the posterior pole with 308 nm and complete absorption was noted with 193 nm. The extinction in the anterior part of aphakic eyes (the first 6 mm) was 4.2/cm for 308 nm, meaning ...

1990-11-01

173

Ultra-high pressure water jet: Baseline report  

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 ...

1997-07-01

174

The Herschel revolution: unveiling the morphology of the high mass star formation sites N44 and N63 in the LMC  

CERN Document Server

We study the structure of the medium surrounding sites of high-mass star formation to determine the interrelation between the HII regions and the environment from which they were formed. The density distribution of the surroundings is key in determining how the radiation of the newly formed stars interacts with the surrounds in a way that allows it to be used as a star formation tracer. We present new Herschel/SPIRE 250, 350 and 500 mum data of LHA 120-N44 and LHA 120-N63 in the LMC. We construct average spectral energy distributions (SEDs) for annuli centered on the IR bright part of the star formation sites. The annuli cover ~10-~100 pc. We use a phenomenological dust model to fit these SEDs to derive the dust column densities, characterise the incident radiation field and the abundance of polycyclic aromatic hydrocarbon molecules. We see a factor 5 decrease in the radiation field energy density as a function of radial distance around N63. ...

2010-01-01

175

Standardizing regulations on production of mining electrical equipment  

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 ...

1983-02-01

176

Fixed time and fixed point observation of environmental radioactivities in Tokyo  

Energy Technology Data Exchange (ETDEWEB)

A measurement of environmental radioactivity in Tokyo was started from 1974. We have been executing fixed time and fixed point observation since 1983 in Tokyo continuously. Measurement item is rain water, airborne dust, activated sludge at sewage treatment plants and external dose rate. Measurement data from 1983 to 1995 is reported in this paper. Moreover, we have been carried out the measurement of radon concentration in air from 1988 to 1991 in different types of residental buildings. The measurement results of rain water, airborne dust, external dose rate were approximately a background level respectively except for the Chernobyl nuclear power plant accident. Radionuclides used as radiopharmaceuticals were detected in the activated sludge at every sewage treatment plant but its concentration was lower than concentration limit in Japan. From a result of radon concentration measurements, there were no place which exceeds a radon concentration ...

1997-03-01

177

Effect of primary air content on formation of nitrogen oxides during combustion of Ehkibastuz 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 ...

1986-01-01

178

Column leaching test to evaluate the use of alkaline industrial wastes to neutralize acid mine tailings  

Energy Technology Data Exchange (ETDEWEB)

Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals that releases highly acidic, sulfate, and metals-rich drainage. In this study, alkaline industrial wastes were mixed with acid mine tailings in order to obtain neutral conditions. A series of column leaching tests were performed to evaluate the behavior of reactive mine tailings amended with alkaline-additions under dynamic conditions. Column tests were conducted of oxidized mine tailings combined with cement kiln dust, red mud bauxite, and mixtures of cement kiln dust with red mud bauxite. The pH results show the addition of 10% of alkaline materials permits the maintenance of near neutral conditions. In the presence of 10% alkaline material, the concentration of toxic metals such as Al, Cu, Fe, Zn are significantly reduced as well as the number of viable cells (Thiobacillus ferrooxidans) compared to control samples.

2005-08-01

179

Abrasion wear studies with abrasives from brown coal beneficiation  

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)

1983-01-01

180

Renovation of air-conditioning at La Defense; Renovation de la climatisation a La Defense  

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.)

1997-05-01

181

Quality engineering and control. Semiannual progress report, May-October 1979  

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.

182

Problematic of atmospheric pollution in Lebanon: the better stake is apprehended, the best acts are taken  

International Nuclear Information System (INIS)

The article is an overview on atmospheric pollution in Lebanon. It presents an analysis of sources of pollution in the country and their impacts on local and global environment and describes their control. Air pollution is mainly due to the industrial, electrical and transportation sectors. Pollutants from fuel combustion are analyzed. It is estimated that in 2010, CO_2 emissions will reach 5987250 tons, SO_2 emissions is estimated to be 182950 tons, Nox to 105180 and dusts to 4965 tons. CFC consumption and measures of control according to Montreal protocol are described. Consumption of primary energy, consumption of petroleum products, quantity of petroleum in refineries and production of cement in Lebanon are also presented in tables

2000-02-01

183

Microwave drying of fine coal  

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.

1989-03-01

184

Method for treating red mud  

Energy Technology Data Exchange (ETDEWEB)

In order to improve the handling capability of red mud, it is mixed with fine-grain coal material such as brown coal or lignite in dust form, in a ratio by weight of between 0.5-10:1. The liquid present in the red mud is bound by the very fine coal admixed therewith so that the resulting mixture can be stored in a silo and even pneumatically conveyed, and the oily properties of the red mud are removed by the treatment. The mixture is particularly suitable for use in connection with the hydrogenating liquefaction of coal in which the red mud is used as a catalyst.

1984-08-07

185

Flue gas desulfurization. Rauchgasentschwefelung  

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.

1983-04-07

186

Confrontation between stellar pulsation and evolution; Proceedings of the Conference (ASP Series, Vol. 11), Bologna, Italy, May 28-31, 1990  

International Nuclear Information System (INIS)

Attention is given to the folowing topics: population I and II variable stars; LP variables, the sun, and mass determination; and predegenerate and degenerate variables. Particular papers are presented on alternative evolutionary approaches to the absolute magnitude of the RR Lyrae variables; the evolution of the Cepheid stars; nonradial pulsations in rapidly rotating Delta Scuti stars; dynamical models of dust shells around Mira variables; and pulsations of central stars of planetary nebulae.

1990-05-28

187

Clean Technology Application : Kupola Model Burner for Increasing the Performance of Spent Accu Recycle  

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)

2000-02-01

188

Atomic power of Germany and ecology  

International Nuclear Information System (INIS)

The NPPs safety system in Germany is discussed. It is shown that there exists no threat for the German NPPs at the peace times. They release insignificant quantities of radioactive substances into the water and atmosphere. The average equivalent dose constitutes 0.0005 mSv annually. The annual equivalent dose for the personnel is equal to 4.4 mSv. At the same time, the NPPs contribute to a certain degree to the environmental medium improvement, preventing the ingress therein of the sulfur and carbon dioxide, dust and nitrogen oxides by application of fossil fuels. Attention is also paid to reprocessing facilities and also to the nuclear fuel wastes disposal. The advantages of the nuclear power engineering in comparison with the fossil fuel power engineering are enumerated

189

Aspiration cover for the loading site of a belt conveyer  

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.

1982-01-01

190

Tests with cleaned and uncleaned gas on a pilot plant. Final report  

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 ...

1986-01-01

191

Safety-technical characteristics of biomass, coal and straw. Final report  

Energy Technology Data Exchange (ETDEWEB)

Safety-technical factors related to spontaneous ignition and dust explosions of biomasses were investigated. Parametres of dust explosions and effect of inertisation on the maximum pressure (pmax) and the maximum rate of pressure rise (Kstmax) were studied at elevated initial pressure (1-9 bar). The level of inertisation required to prevent dust explosions totally was determined at different initial pressures. The sensitivity of fuels to spontaneous ignition and the effect of pressure on the sensitivity to and temperature of spontaneous ignition were studied on a pressurised dynamic self-ignition equipment. The effect of inertisation on the self-ignition temperature and alternatives of preventing spontaneous ignition by effective inertisation in the pressure ranges of 1 and 25 bar were investigated. As an example of application, results obtained with the laboratory test equipment were extrapolated to bin sizes used in ...

1995-12-31

192

Waste characterization study for the Kemp's Ridley sea turtle. Technical memo  

Energy Technology Data Exchange (ETDEWEB)

The Kemp's Ridley sea turtle, Lepidochelys kempi, is an endangered species. The National Marine Fisheries Service's Head Start program is part of an international operation to save the turtles from extinction. Under the Head Start program, eggs from the Ridley's only known wild nesting beach at Rancho Nuevo in Mexico are transported to Padre Island on the Texas coast to be hatched. The head start enables the turtles to develop a survival advantage. The principal objective was to develop baseline waste-characterization data required to design a waste-water treatment scheme for the Galveston Head Start facility. As a secondary objective, preliminary testing of some filtration components was undertaken to determine which units were most appropriate for inclusion in a wastewater treatment scheme.

1988-02-01

193

VIS harvesting unsymmetrical squaraine dye for dye-sensitized solar cells  

British Library Electronic Table of Contents (United Kingdom)

An unsymmetrical squaraine dye which contains an arylamino group was synthesized and used in dye-sensitized solar cells. The molar extinction coefficient of the dye is 77793 M-1 cm-1. Because our synthesized molecule may have no diradical character or the contribution of the diradicaloid component to resonance is quite small, the newly designed squaraine dye has a maximum absorption at 546 nm in the visible region compared with the NIR squaraine sensitizers. Cyclic voltammetry and time dependent density function theory calculation were accomplished to scrutinize the sensitized performance of the dye. Meanwhile, the novel sensitizer has been used to sensitize nanocrystalline TiO2-based solar cell. Under standard global AM 1.5 solar conditions, the squaraine dye-sensitized cell gives a short...

2012-01-01

194

Utilization of low rank coals in liquefaction  

Energy Technology Data Exchange (ETDEWEB)

The objective of the current MITRE study is to estimate the cost of the coal derived liquid products that result from processing low rank coals in the Wilsonville and HRI CTSL configurations. The resultant cost of liquids is then compared to liquids produced from bituminous coals. The methodology used to accomplish the above objective was to utilize the MITRE coal liquefaction cost model to assess the overall technical and economic performance of low rank coals in both the Wilsonville and HRI configurations. Actual test data from Wilsonville and HRI was used as the basis for these analyses. This test data is modified to simulate complete resid recycle extinction and to standardize the operating performance of the deashing unit. This corrected yield data is then used in the simulation models to predict the overall performance and economics of a conceptual commercial coal liquefaction facility. 9 refs., 7 figs.

1991-01-01

195

The structure of molecular clouds - III. A link between cloud structure and star formation mode  

British Library Electronic Table of Contents (United Kingdom)

Abstract We analyse extinction maps of nearby giant molecular clouds to forge a link between driving processes of turbulence and modes of star formation. Our investigation focuses on cloud structure in the column density range above the self-shielding threshold of 1-mag AV and below the star formation threshold - the regime in which turbulence is expected to dominate. We identify clouds with shallow mass distributions as cluster forming. Clouds that form stars in a less clustered or isolated mode show a steeper mass distribution. Structure functions prove inadequate to distinguish between clouds of different star formation mode. They may, however, suggest that the turbulence in the average cloud is governed by solenoidal forcing. The same is found using the -variance analysis which also in...

2011-01-01

196

The phosphate complexation of neptunium(V)  

International Nuclear Information System (INIS)

The phosphate complexation of Np(V) is investigated in the pH range from 6.4 to 10.0 in 0.1 M NaClO_4 at 22#+-#2 C by absorption spectroscopy. The formation of two phosphate complexes is confirmed by spectroscopic speciation: NpO_2HPO"-_4 at 988.8 nm and NpO_2PO"2"-_4 at 993.6 nm with molar extinction coefficients of 251#+-#8 and 201#+-#11 1/mol cm, respectively. The complexation constants are determined to be log #beta# = 2.54#+-#0.02 for NpO_2HPO"-_4 and log #beta# = 6.33#+-#0.08 for NpO_2PO"2"-_4. The competition of the phosphate complexation with the carbonate complexation is demonstrated by speciation calculation under different geochemical conditions. (orig.).

1996-01-01

197

The Need to Rationalize and Prioritize Threatening Processes Used to Determine Threat Status in the IUCN Red List  

British Library Electronic Table of Contents (United Kingdom)

Abstract: Thorough evaluation has made the International Union for Conservation of Nature (IUCN) Red List the most widely used and accepted authority on the conservation status of biodiversity. Although the system used to determine risk of extinction is rigorously and objectively applied, the list of threatening processes affecting a species is far more subjectively determined and has not had adequate review. I reviewed the threats listed in the IUCN Red List for randomly selected groups within the three most threatened orders of mammals: Artiodactyla, Carnivora, and Primates. These groups are taxonomically related and often ecologically similar, so I expected they would suffer relatively similar threats. Hominoid primates and all other terrestrial fauna faced similar threats, except for b...

2009-01-01

198

Synthesis and luminescence of Eu"3"+ and Tb"3"+ complexes with novel calix[4]arene ligands carrying 2,2'-bipyridine subunits  

International Nuclear Information System (INIS)

Eu"3"+ and Tb"3"+ complexes with novel branched calix[4]arene ligands incorporating 2,2' -bipyridine subunits functionalized in the 6- or 5,5'-positions have been synthesized and their photophysical properties investigated. High luminescence intensity was obtained for the Eu"3"+ complex of the calix[4]arene ligand carrying four 5,5' -substituted- 2,2' -bipyridines, which has high molar extinction coefficients (#epsilon#_m_a_x 39 600 M"-"1 cm"-"1) and a high luminescence quantum yield (15%). (authors). 12 refs., 2 figs., 1 tab.

1995-01-01

199

Sulfonaphtholazoresorcinol as reagent for tungsten  

International Nuclear Information System (INIS)

Interaction of W(6) with sulphonaphtholazoresorcinol (SNAR) in aqueous solution has been studied. Tungsten is determined in the form of sulphonaphtholazoresorcinate by extraction with higher alcohols. The optimum conditions for the formation of a complex of W with SNAR in aqueous solution are as follows: a 10-fold excess of SNAR, concentration of HCl 1-1.5N, ethanol content 5-10 vol.%, time of formation of the complex 30 min. A component ratio for the complex has been established in the case of aqueous solution and extract; molar extinction coefficients are 0.9x10"4 and 1.7x10"4, respectively. The formation constant for the complex being extracted is 2.2x10"2"3. A method has been developed for determination of microgram quantities of W in a vanadium specimen.

1977-01-01

200

Study of interaction between 7-(6-Br-2-benzthiazolylazo)-8-oxiquinoline-5-sulfonic acid and uranium (6), zinc (2) and manganese (2)  

International Nuclear Information System (INIS)

A new reagent 7-(6-Br-2-henzthiazolilazo)-8-oxyquinoline-5-sulphoacid has been studied spectrophotometrically. Dissociation constants have been determined in 50% acetone (pK_1=2.5 and pK_2=5.9) and 50% dioxane (pK_1=1.7 and pK_2=6.1) as well as molar extinction coefficients of the reagent dissociated form in the same solvents (71.1.10"3 and 72.4.10"3). The conditions have been studied of complexing the reagent with ions of uranium (6), zinc (2), and manganese (2) in 50% dioxane (pH 2.5-4.5) and the properties of the formed complexes.

1977-01-01

201

Spectrophotometric study of lanthanoid complexes with antipyrine and salicylic acid  

International Nuclear Information System (INIS)

The extraction-spectrophotometric method has been used to study lanthanoid ion complexing (Pr, Nd, Ho and Er) with antipyrine (Ant) and salicylic acid (Sal). The component relationship in different-ligand compounds Ln:Aut:Sal=2:3:6 and solvate number equal to 5 are determined; molar extinction coefficients of binary and different-ligand compounds are calculated. Oscillator strengths of absorption bands corresponding to supersensitive transitions of neodymium, holmium, erbium and some most intensive praseodymium bands are calculated. The study of IR spectra of investigated compounds allows to conclude on formation of coordination bonds of the central atom with the antipyrine molecule through the oxygen of the carbonyl group as well as on carboxyl group hydrogen substitution for metal and formation of coordination bond with OH group in salicylic acid molecules.

1981-01-01

202

Problems of air pollution monitoring  

Energy Technology Data Exchange (ETDEWEB)

The development of the monitoring network for background measurements of air pollution in the USSR is noted. The use of paired stations, to aid in locating permanent sites as well as for determining the local component of background air pollution, is described. Thermoelectric actionometers with five glass filters are used to measure Shupp's turbidity coefficient for estimating extinction of solar radiation due to aerosols. Sampling and chemical analysis of precipitation uses methods developed during the International Geophysical Year. An intercomparison of meteorological instruments was carried out in the USSR in 1973 and 1978. The most stable actinometer was the Linke-Foisner device. Chemical analyses of precipitation made since 1958 in the USSR show increases in air pollution levels only in particular areas.

1980-01-01

203

Preparation of tetravalent praseodymium in potassium phosphotungstate aqueous solutions  

International Nuclear Information System (INIS)

The possibility has been studied of oxidizing Prsup((3)) to Prsup((4)) when Prsup((3)) is added to an aqueous weakly-acid solution containing K_1_0[P_2W_1_7O_6_1H_2O] x H_2O. A sharp change in the solution colouring has been observed as a result of Prsup((3)) oxidation to Prsup((4)). The absorption spectra of solution of Prsup((4)) have been recorded and the values of the molar extinction coefficients have been determined. On storage of the solution, Prsup((4))reduces to Prsup((3)) with a half-reduction period of 0.2-0.5 hour.

1977-01-01

204

On the interaction of vanadium (4) with derivatives 3,4,5-trihydroxy-isoxanthene  

International Nuclear Information System (INIS)

A study was made on interaction of vanadium (4) ions with dyes-pyrogallol red, brompyrogallol red and gallein- in the range of pH = 0-6. The maximal light absorption for gallein and brompyrogallol red is observed at pH=4 and #lambda#max = 545 nm and 560 nm respectively. The compound of vanadium (4) with pyrogalloe red is characterized by the maximal light absorption at pH=5 and #lambda#max=560 nm. Component ratio in all analyzed compounds is equal to 1:2. Molar extinction coefficients for compounds with gallein, pyrogallol red and brompyrogallol red are equal to 5000, 550 and 7400, and logarithms of stability constants - to 9.27, 13.17 and 13.25 respectively.

205

Monitoring noise-resonant effects in cancer growth influenced by spontaneous fluctuations and periodic treatment  

CERN Document Server

In the paper we investigate a mathematical model describing the growth of tumor in the presence of immune response of a host organism. The dynamics of tumour and immune cells is based on the generic Michaelis-Menten kinetics describing interaction and competition between the tumour and the immune system. The appropriate phenomenological equation modeling cell-mediated immune surveillance against cancer is of the predator-prey form and within a given choice of parameters exhibits bistability. Under the influence of spontaneous weak fluctuations, the model may be analyzed in terms of a stochastic differential equation bearing the form of an overdamped Langevin-like dynamics in the external quasi-potential represented by a double well. We analyze properties of the system within the range of parameters for which the potential wells are of the same depth and when the additional perturbation describing a periodic treatment is insufficient to overcome the barrier height and to cause cancer ...

2007-01-01

206

Mixed-ligand complexes of scandium with 4-(2-pyridylazo)resorcinol and monocarboxylic acids  

International Nuclear Information System (INIS)

Scandium reacts with 4-(2-pyridylazo)resorcinol in the presence of monocarboxylic acids (X) to form mixed-ligand complexes with a Sc:PAR:x ratio of 1:2:2. The chemical nature of this interaction has been established, and the extraction of these mixed-ligand complexes has also been investigated; stability constants and molar extinction coefficients have been calculated. The values of the latter decrease in the order CH_3COOH > CH_2ClCOOH > CCl_3COOH. The formation and extraction of mixed-ligand complexes in Sc-PAR-HX systems make it possible to increase the sensitivity and selectivity of scandium determination in comparison with the use of the Sc-PAR mono-ligand complex.

1987-09-01

207

Loss of genetic connectivity and diversity in urban microreserves in a southern California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus n. sp. ?santa monica??)  

British Library Electronic Table of Contents (United Kingdom)

Microreserves may be useful in protecting native arthropod diversity in urbanized landscapes. However, species that do not disperse through the urban matrix may eventually be lost from these fragments. Population extinctions may be precipitated by an increase in genetic differentiation among fragments and loss of genetic diversity within fragments, and these effects should become stronger with time. We analyzed population genetic structure in the dispersal limited Jerusalem cricket Stenopelmatus n. sp. ?santa monica?? in the Santa Monica Mountains and Simi Hills north of Los Angeles, California (CA), to determine the impacts of fragmentation over the past 70 years. MtDNA divergence was greater among urban fragments than within contiguous habitat and was positively correlated with fragment ...

2009-01-01

208

Intermediates of radiolytic transformations of 6-aminophenalenone in ethanol  

International Nuclear Information System (INIS)

Pulsed radiolysis method is used to study transformations intermediates of 6-aminophenalenone in ethanol. In alkaline medium the main product is radical-anion of 6-aminophenalenone, which optical absorption spectrum contains two bands with maxima at 355 and 400 nm. The particle precursors are e_s, CH_3CHOH and CH_3CHO"- radicals. In neutral and acid medium radical-anions are protonated in reactions with alcohol and hydrogen ions. The resulting H-adduct of 6-aminophenalenone has optical absorption maxima at 350 and 390 nm. Availability of two maxima is related to two various product structures. Molar extinction coefficients of radical-anions and H-adducts of 6-aminophenalenone and rate constants of reactions with their participation are estimated.

1992-01-01

209

Intermediate products of radiolytic conversions of 6-aminophenalenone in ethanol  

International Nuclear Information System (INIS)

Intermediate products of the conversions of 6-aminophenalenone in ethanol were investigated by pulse radiolysis. In alkaline medium the main product is the 6-aminophenalenone radical cation, the optical absorption spectrum of which contains two bands with maxima at 355 and 400 nm. The precursors of this particle are e_s, CH_3CHOH and CH_3CHO"- radicals. In neutral and acid medium, radical cations are protonated in reactions with alcohol and hydrogen ions. The H-adduct of 6-aminophenalenone that arises has optical absorption maxima at 350 and 390 nm. The presence of two maxima is due to two different structures of the product. The molar extinction coefficients of the radical anions and H-adducts of 6-aminophenalenone and the rate constants of the reactions involving them were estimated. 6 refs., 4 figs., 2 tabs.

1992-01-01

210

Interaction of rare earths with orthanyl K and its spectrophotometric determination in binary mixtures  

International Nuclear Information System (INIS)

A study has been made of the colour reaction involved in the interaction or rare-earth elements with the reagent orthanyl K, the optimum conditions for the reaction being: pH=4.0-4.5 and lambda=660-670 nm. The ratio of components in the complex is Me:R=1:2. Consideration of the relative optical density values of the complex solutions as a function of the serial number of the rare-earth elements made it possible to recommend orthanyl K as a selective reagent for determining La, Ce, Pr and Nb in a mixture of Tu, Yb, Lu and Y oxides. The molar extinction coefficients, the sensitivity of the reaction and the concentration limits where Beer's law applies were calculated. Lanthanum was determined in a binary mixture with thulium and yttrium. (author).

1975-01-01

211

Identity and yield of positive charge centers in irradiated chloro hydrocarbon liquids and the rates of their interaction with solute molecules. [3-4 MeV electrons  

Science.gov (United States)

Pulse radiolysis studies of the formation kinetics and the yields of various phenylcarbenium ions from several different solutes in 1,2-dichloroethane solution have been carried out. The results indicate that there are two kinetically distinguishable cationic species of the solvent which react selectively with the different solutes to form the phenylcarbenium ions. It is suggested that one is a cation radical (yield 0.68 molecule/100 eV) and the other a carbocation (yield 0.20 molecule/100 eV). Rate constants for their separate reactions with selected aromatic compounds and with ammonia have been determined. Molar extinction coefficients have been estimated for benzyl cation, diphenyl cation radical, and anthracene cation radical. 6 figures, 1 table.

1979-07-26

212

Identity and yield of positive charge centers in irradiated chloro hydrocarbon liquids and the rates of their interaction with solute molecules  

International Nuclear Information System (INIS)

Pulse radiolysis studies of the formation kinetics and the yields of various phenylcarbenium ions from several different solutes in 1,2-dichloroethane solution have been carried out. The results indicate that there are two kinetically distinguishable cationic species of the solvent which react selectively with the different solutes to form the phenylcarbenium ions. It is suggested that one is a cation radical (yield 0.68 molecule/100 eV) and the other a carbocation (yield 0.20 molecule/100 eV). Rate constants for their separate reactions with selected aromatic compounds and with ammonia have been determined. Molar extinction coefficients have been estimated for benzyl cation, diphenyl cation radical, and anthracene cation radical. 6 figures, 1 table.

1979-07-01

213

Hydrogen-atom attack on methyl viologen in aqueous solution studied by pulse radiolysis  

International Nuclear Information System (INIS)

Using hydrogen at high pressures of up to 150 bar as an OH scavenger in aqueous MV"2"+ solutions (pH 1) it is possible to differentiate between two kinds of transient formed simultaneously by H-atom attack on methyl viologen. One of them is assigned to an H adduct on the N atom, MV"+H"+, with absorption bands identical to those of the radical cation, MV"+. The MV"+H"+ species deprotonates forming the long-lived radical cation, MV"+. The second type of transient produced is attributed to an H-adduct on the ring carbon, MV"2"+H, decaying by second-order kinetics. The formation of MV"+ by electron transfer from the propan-2-ol radical has been reinvestigated (pH 0 to 7); its absorption spectrum does not change in this pH range. Rate constants and molar extinction coefficients are presented. (U.K.).

1984-01-01

214

Hydrogen lines in the high-luminosity quasar B2 1225+31  

International Nuclear Information System (INIS)

The emission lines H#alpha#, H#beta#+[OIII], and L#alpha# have been observed in the high-redshift quasar 1225+31. The ratios of line intensities in 1225+31 are found to be L#alpha#/H#alpha#approx.0.8, H#alpha#/(H#beta#+[OIII]) approx.4, and 4extinction between the Sun and 1225+31.

215

Extraction of americium of different oxidation states in two-phase aqueous system based on polyethylene glycol  

International Nuclear Information System (INIS)

Americium extraction in different oxidation states in two-phase aqueous system based on polyethylene glycol is investigated. Conditions for quantitative extraction of americium (3) and americium (5) from ammonium sulfate solutions within pH=3-5 interval in the presence of arsenazo 3 are found. Composition of the produced americium complexes with reagent is determined; americium (3) interacts with arsenazo 3 in ammonium sulfate solutions with the formation of MeR and Me_2R composition complexes. Absorption spectrum characteristics of americium (3) and- (5) complexes with arsenazo 3 in ammonium sulfate solutions and extracts based polyethylene glycol aqueous solutions are given. Molar extinction coefficients of americium complexes with arsenazo (3) in these solutions are determined.

1987-01-01

216

Effects of allelochemicals produced by one population in a chemostat-like environment  

British Library Electronic Table of Contents (United Kingdom)

In this paper, we study some general models suggested to describe the effects of chemical compounds produced by an algal population on its survival in a chemostat-like environment. The conditions for its persistence and extinction are found. In particular, in the first model we make very general assumptions to represent the uptake, the regulative and the inhibiting functions, and analyze its global stability completely. In the second one we specify the first two functions and leave general the third one. Here the regulative function has different property from that in the first model, and a saddle-node bifurcation phenomenon occurs. In addition, according to the experimental data reported in DellaGreca et al. [2010. Fatty acids released by Clorella vulgaris and their role in interference w...

2011-01-01

217

Earliest art in the Americas: incised image of a proboscidean on a mineralized extinct animal bone from Vero Beach, Florida  

British Library Electronic Table of Contents (United Kingdom)

A fragmented fossil bone incised with the figure of a proboscidean was recently found at Vero Beach, Florida near the location where Late Pleistocene fauna and human bones were recovered from 1913 to 1916. This engraving may represent the oldest and only existing example of Terminal Pleistocene art depicting a proboscidean in the Americas. Because of the uniqueness, rarity, and potential antiquity of this specimen, caution demanded that a variety of tests be used in an attempt to verify its authenticity. The mineralized bone was identified as mammoth, mastodon, or giant sloth. Rare earth element analysis was consistent with the fossil bone being ancient and originating at or near the Old Vero site (8-IR-9). Forensic analysis suggests the markings on the bone are not recent. Optical microsc...

2011-01-01

218

Determination of rare earths in eluates after chromatographic separation  

International Nuclear Information System (INIS)

Spectrophotometry was used to study the conditions under which three-component complexes are formed of rare-earth elements (REE) with aminopolycarboxylic complexes and #beta#-diketones; the molar extinction coefficients of the above REE complexes were also found. A procedure is suggested for determining REE in chromatographic eluates with lower boundary of the contents determined being at 0.6-1.5 #mu#g/ml (Pr, Nd, Ho and Er) and 5-7 #mu#g/ml (Sm and Tm) with account for oxides. Luminescent techniques were also suggested for determining terbium in the presence of EDTA and terbium in an eluate containing EDTA and oxyethyl ethylene diamine triacetic acid, both acids being characterized by a relative standard deviation equal to 0.015-0.03.

1977-01-01

219

Complexing of vanadium(3) with chromotropic acid derivatives  

International Nuclear Information System (INIS)

A spectrophotometric study has been made of the complex formation of vanadium (3) with arsenazo(1), arsenazo(3) and some monosubstituted derivatives of chromotropic acid and sulphanylamides. In acid medium vanadium (3) reacts with each of these reagents to produce a 1:1 complex. Optimum conditions of the complex formation was found. The effect of H"+ on the complex formation of vanadium (3) with chromotropic acid derivatives was established. It was found by the graphical method that the formation of the complex is accompanied by the elimination of one proton. Patterns were found of the influence of the nature of substituents in the organic compound on the ionization constants of acid groups and stability of complexes. Molar extinction coefficients, equilibrium constants of the formation reactions and instability constants for the complexes were calculated. The structure of complexes was suggested. Similar behaviour of all the reagents was established in the complex ...

1976-01-01

220

Application of laser fluorimetry for determining the influence of a single amino-acid substitution on the individual photophysical parameters of a fluorescent form of a fluorescent protein mRFP1  

International Nuclear Information System (INIS)

Individual photophysical parameters of the chromophore of a fluorescent protein mRFP1 and its two mutants (amino-acid substitution at position 66 - mRFP1/ Q66C and mRFP1/Q66S proteins) are determined. For this purpose, apart from conventional methods of fluorimetry and spectrophotometry, nonlinear laser fluorimetry is used. It is shown that the individual extinction coefficients of the chromophore of proteins correlate (correlation coefficient above 0.9) with the volume of the substituted amino-acid residue at position 66 (similar to the positions of the absorption, fluorescence excitation and emission maxima). (laser biology and medicine)

2009-03-31

221

A study of the B 24 - A 19 transition of benzene molecule in different matrices  

International Nuclear Information System (INIS)

Ultraveiolet spectroscopy of molecules in vapour phase gives valuable information about electronic structure of free molecules. But in many cases vaipour phase investigations are not possible and in order to isolate molecules within solid lattice, we used cryogenic temperature and high vacuum technology to study absorption spectrum within the spectral range (230-270)nm of an isolated benzene molecule in Argon, Krpton, Nitrogen, Carbon and methane matrices. The spectra shifts were measured and calculated in the matrix environment for the electronnic transition (B 24--A 19) in benzene molecule using the matrices mentioned above. Molar extinction coefficients and oscillator strength were measured too. (7 tabs., 32 figs., 50 refs.).

1988-01-01

222

A routine chemical dosimetric system using the modified ceric sulphate dosimeter  

International Nuclear Information System (INIS)

The radiolytic reduction of the Ce4+ in a 0.8N sulfuric acid was examined, with the objective of measuring large radiation doses. the ceric sulphate dosimeter was tested in the range from 1 to 20kGy. The 0.01 M sodium oxalate solution was chosen instead of the arsenious oxide solution (used in the conventional method), in order to obtain a less expensive dosimetric system than that normally use for routine chemical dosimetry. The absorption spectrum of the Ce"4"+ solution presents an absorption peak at 370 nm; the obtained molar extinction coefficients of Ce"4"+ and Ce"3"+ were 5670 and 2.7 M"-"1 cm"-"1 respectively. The purpose of this work was to establish a simple, reliable and inexpensive routine chemical dosimetric system for high doses.

1994-10-01

223

Tribromo-chlorophosphonazo used for photospectrometric determination of total rare earth in high-level liquid waste  

International Nuclear Information System (INIS)

The Procedure determining the concentrations of total rare earth and their determination with a new reagent, tribromochlorophosphonazo (CPA-tB), that is 7-[1-(2, 4, 6-tribromo-phenyl) azo]-2-[1-(2-phosphono-4-chloro-phenyl) azo]-chromotropic acid, in high-level liquid waste and some characters of CPA-tB are studied. CPA-tB and its complexes of rare earth elements are stable in the glycol-H_2O system. Adding glycol shifts the absorption spectrum to left and increases the molar extinction coefficient. The molar extinction coefficients are respectively 7.16 x 10"4 (Y), 11.9 x 10"4 (La), 11.7 x 10"4 (Ce, Pr), 11.9 x 10"4 (Nd), 11.6 x 10"4 (Sm, Eu), 11.4 x 10"4 (Gd) and 11.4 x 10"4 (RE) in the glycol-H_2C_2O_4-H_3PO_4-H_2O system at 643 nm. Th interferes severely the determination of total rare earth, and other elements, U(<100 #mu#g), Al(<20 #mu#g), Fe(<400 #mu#g), Ni,Zr(<100 #mu#g respectively) and some anions, MoO_4"2"- (<2800 ...

1992-01-01

224

Fossil avian eggshell preserves ancient DNA  

DEFF Research Database (Denmark)

Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has approximately 125 times lower bacterial load than bone, ...

2010-01-01

225

Aerosol Properties Over the United Arab Emirates and Arabian Gulf from MISR Multi-angle Satellite Imaging  

Science.gov (United States)

The MISR instrument aboard NASA's Terra satellite participated in the UAE-2 campaign, August-October 2004. This campaign represented a unique opportunity to study the complex aerosol situation in the Arabian Gulf region, in the context of a first-rate collection of aircraft and surface-based instruments, giving us the opportunity to do some groundbreaking satellite aerosol validation work. We aimed (1) to validate MISR aerosol retrieval results for dust and pollution particles over dark and light surfaces, and (2) to contribute regional maps of aerosol optical thickness (AOT) and particle micro-physical properties, giving spatial context to the field-instrument measurements, and moving toward a satellite-based regional aerosol climatology. The validation effort benefited from the combination of an instrumented aircraft and a regional network of surface-based sun photometers. We obtained high-quality sub-orbital data coincident with MISR overpasses on three days: ...

2005-12-01

226

Spitzer Mid-infrared Study of Compact HII Regions in the Magellanic Clouds  

CERN Document Server

We present a study of the mid-infrared properties and dust content of a sample of 27 HII ``blobs'', a rare class of compact HII regions in the Magellanic Clouds. A unique feature of this sample is that even though these HII regions are of high and low excitation they have nearly the same physical sizes ~1.5-3 pc. We base our analysis on archival 3-8 microns infrared imagery obtained with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope. We find that despite their youth, sub-solar metallicity and varied degrees of excitation, the mid-infrared colors of these regions are similar to those of typical HII regions. Higher excitation ``blobs'' (HEBs) display stronger 8 micron emission and redder colors than their low-excitation counterparts (LEBs).

2008-01-01

227

Spitzer Imaging of Herschel-ATLAS Gravitationally Lensed Submillimeter Sources  

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.

2010-01-01

228

Problematic of atmospheric pollution in Lebanon: the better stake is apprehended, the best acts are taken  

International Nuclear Information System (INIS)

Lebanon has imported in 1996 5000 Kt of carburants causing about 80 Kt of SO_x; 40 Kt of NO_x; 3 Kt of dusts and 3.5 million tons of CO_2. The atmospheric pollution in Lebanon is due to three main sources: - Thermal central of electric production - Industries (cement) - Transportation sector The document describes in tables: the inventory of pollutants and pollutant emissions in 1993 and 2010; industrial and heating gas oil; liquified petroleum gas commercial propane; fuel oil for EDL; consumption of energy in 1996; sectorial distribution of pollutants PPM; emissions of CO_2 per tons per habitant in 1993; consumption in 1993 broken down by use and application. Finally, three projects concerning public transportation were presented

1999-06-02

229

Potentially pathogenic free-living amoebae isolated from hospital wards with immunodeficient patients in Tehran, Iran  

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...

2011-01-01

230

Pilot project ''measurement of efficacy'' - biological monitoring of antimony pollution in the Munich test area using a standardized grass culture  

International Nuclear Information System (INIS)

This pilot project was carried out for the purpose of testing methods for active biological monitoring. It covered a period of three years (until September 1994), including two years of exposure. The measurements served to determine pollutant levels in plants used as animal fodder and dust-borne heavy metal concentrations in different sites and, on this basis, to obtain indirect information on human exposure. Among others, the pilot project investigated the suitability of Italian rye-grass as a biological indicator for aluminium, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, magnesium, manganese, nickel, lead, platinum, antimony, titanium, and zinc. (orig./GL).

231

Photoluminescence Decay of Irradiated Herbs  

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)

1999-07-01

232

Photoluminescence Decay of Irradiated Herbs  

International Nuclear Information System (INIS)

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)"-"P. The influence of both B and P factors upon the irradiation dose has been systematically analysed. (author)

1998-07-05

233

Natural gas and quality of fuels for the reduction of atmospheric pollution  

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 ...

1998-01-01

234

Lead content of fetal tissues after maternal intoxication  

Energy Technology Data Exchange (ETDEWEB)

A female employee was exposed to lead dust for 8 h daily from 4.5.1982 to 20.5.1982. During this time conception occurred (1st day of last menses 4.5.82). Acute symptoms of lead intoxication were not observed in this subject but were in other employees. Measurements of lead content were started after the end of exposure and continued for 6 months until normal values were obtained. Because of the half-life of nearly 20 days for lead elimination from blood the estimated body burden at the end of exposure was about 1200 ppb. The fetal tissue samples contained between 0.4 (brain) and 7.9 (liver) ..mu..g lead/g dry weight. The fetal lead was mainly stored in bone, blood and liver. From the results given a delayed elimination of fetal lead is suggested.

1986-02-01

235

Junction conditions in General Relativity with spin sources  

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 ...

2006-01-01

236

Interferometer Observations of Subparsec-scale Infrared Emission in the Nucleus of NGC 4151  

CERN Document Server

We report novel, high-angular resolution interferometric measurements that imply the near-infrared nuclear emission in NGC 4151 is unexpectedly compact. We have observed the nucleus of NGC 4151 at 2.2 microns using the two 10-meter Keck telescopes as an interferometer and find a marginally resolved source ~0.1 pc in diameter. Our measurements rule out models in which a majority of the K band nuclear emission is produced on scales larger than this size. The interpretation of our measurement most consistent with other observations is that the emission mainly originates directly in the central accretion disk. This implies that AGN unification models invoking hot, optically thick dust may not be applicable to NGC 4151.

2003-01-01

237

Induction motor for tunnel exhauster; Tunnel haifukiyo yudo dendoki  

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)

2000-01-10

238

Flame propagation characteristics and flame structures of zirconium particle cloud in a small-scale chamber  

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...

2010-01-01

239

Engine use of producer gas, experiences and requirements  

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.)

1999-07-01

240

Dismantling by explosives  

Energy Technology Data Exchange (ETDEWEB)

Explosives have rarely been used in decommissioning of nuclear reactors. Nevertheless, controlled blasting can be used advantageously during careful destruction of nuclear power plants for removal of concrete, pipe systems, and other components. Experiments performed within a former nuclear power plant demonstrate the feasibility of this method, employing explosive masses up to 15 kg per blast. The loadings of the components and the total plant structure were measured and compared with code predictions. The experiments show a response of the containment predominantly in frequency ranges above 100 Hz, thus keeping the building and components below German regulation limits for shock excitation. The blast wave pressures are reduced drastically within short distances in the building. Dust and debris can be contained with simple methods such as curtains. Use of this method seems to be applicable to actual dismantling projects.

1989-08-01

241

Decontamination factor of an incinerator for radioactive solid wastes  

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.).

242

Cloud Formation and Dynamics in Cool Dwarf and Hot Exoplanetary Atmospheres  

CERN Document Server

The lowest-mass stars, brown dwarfs and extrasolar planets present challenges and opportunities for understanding dynamics and cloud formation processes in low-temperature atmospheres. For brown dwarfs, the formation, variation and rapid depletion of photospheric clouds in L- and T-type dwarfs, and spectroscopic evidence for non-equilibrium chemistry associated with vertical mixing, all point to a fundamental role for dynamics in vertical abundance distributions and cloud/grain formation cycles. For exoplanets, azimuthal heat variations and the detection of stratospheric and exospheric layers indicate multi-layered, asymmetric atmospheres that may also be time-variable (particularly for systems with highly elliptical orbits). Dust and clouds may also play an important role in the thermal energy balance of exoplanets through albedo effects. For all of these cases, 3D atmosphere models are becoming an increasingly essential tool for understanding spectral and ...

2009-01-01

243

Closed-form solutions for some metric perturbations from a closed Friedmann model and the distortion of the universe  

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.

244

Brane-world cosmology with black strings  

CERN Document Server

We consider the simplest scenario when black strings (cigars) penetrate the cosmological brane. As a result, the brane has a Swiss-cheese structure, with Schwarzschild black holes immersed in a Friedmann-Lema\\^{\\i}tre-Robertson-Walker brane. There is no dark radiation in the model, the cosmological regions of the brane are characterized by a cosmological constant $\\Lambda$ and flat spatial sections. Regardless of the value of $\\Lambda$, these brane-world universes forever expand and forever decelerate. The totality of source terms in the modified Einstein equation sum up to a dust, establishing a formal equivalence with the general relativistic Einstein-Straus model. However in this brane-world scenario with black strings the evolution of the cosmological fluid strongly depends on $\\Lambda$. For $\\Lambda$ less or equal to zero it has positive energy density $\\rho$ and negative pressure $p$ and at late times it behaves as in the Einstein-Straus model. For ...

2006-01-01

245

Application research on three-dimensional virtual mine in the framework of internet of things  

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...

2011-01-01

246

Air pollution in Berlin and its surroundings in 1989. Luftverschmutzung in Berlin und Umgebung im Jahr 1989  

Energy Technology Data Exchange (ETDEWEB)

The report presents details of the distributions of air pollution in the Berlin area and the developments of the past 20 years. Highly polluted areas are indicated in which air pollution reduction measures are particularly urgent. The report therefore intends not only to inform but also to point out the deficiencies of air pollution abatement measures, so that political consequences can be derived and measures can be taken. In all, data were recorded by 39 measuring stations in West Berlin, 16 in East Berlin, and 7 in Potsdam and Frankfurt/Oder. In most stations, sulphur dioxide and airborne dust were measured; 14 stations in West Berlin and one in East Berlin measured carbon monoxide and nitric oxides; 8 stations in West Berlin recorded ozone concentrations. (orig./KW).

1990-10-01

247

ARIES-AT safety design and analysis  

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 ...

2006-01-01

248

Tokamak and laboratory modeling of hydrocarbon film deposition on metallic mirrors  

International Nuclear Information System (INIS)

In this work, amorphous hydrocarbon (a-C:H) film deposition on metallic mirrors was studied during working shots in tokamak T-10 and at exposure in Ar/CHD3/D2 dc magnetron discharge in a special laboratory high vacuum setup. Analysis of film composition (including hydrogen content) was carried out using nuclear physical methods. Thickness and optical parameters (refractive and extinction coefficients) of the films were estimated by ellipsometry. Laboratory films can be characterized as soft a-C:H films in comparison with hard tokamak films (? = 1.2 and 1.8 g/cm3, respectively). For the first one, a linear dependence of deposition rate on mirror temperature was observed in a wide temperature range. The addition of methane into initial Ar/D2 magnetron gas mixture leads to an increase of deposition rate. The data obtained should be taken into account to prevent hydrocarbon film formation on the surface of first mirrors in ITER.

2009-06-15

249

Time-dependent radiolytic yields at room temperature and temperature-dependent absorption spectra of the solvated electrons in polyols  

International Nuclear Information System (INIS)

The molar extinction coefficients at the absorption maximum of the solvated electron spectrum have been evaluated to be 900, 970, and 1000 mol-1?m2 for 1,2-ethanediol (12ED), 1,2-propanediol (12PD), and 1,3-propanediol (13PD), respectively. These values are two-third or three-fourth of the value usually reported in the published report. Picosecond pulse radiolysis studies have aided in depicting the radiolytic yield of the solvated electron in these solvents as a function of time from picosecond to microsecond. The radiolytic yield in these viscous solvents is found to be strongly different from that of the water solution. The temperature dependent absorption spectra of the solvated electron in 12ED, 12PD, and 13PD have been also investigated. In all the three solvents, the optical spectra shift to the red with increasing temperature. While the shape of the spectra does not change in 13PD, a widening on the blue side of the absorption band is observed in 12ED and ...

2007-02-01

250

Theoretical study of indoline dyes for dye-sensitized solar cells  

International Nuclear Information System (INIS)

Indoline dye sensitizers were designed and studied theoretically to increase molar extinction coefficients in the visible to near infrared region for solar-cell devices. To gain insight into dye sensitizers' structural, electronic, and optical properties, DFT/TDDFT calculations were performed on a series of dye sensitizers derived from the D149. The good agreement between the experimental and TDDFT calculated absorption spectra of the D149 sensitizer allowed us to provide a detailed assessment of the main spectral features of a series of dye sensitizers. Increase in the conjugation length resulted in a more red-shifted spectral response and less positive oxidation potential than that of the D149. The dye with the dimethylfluorene group showed stronger absorption bands due to a large dipole moment. The calculated dipoles for the dye series correlate well with the observed strong absorption bands of the electronic spectra. These results provided useful clues for the ...

2010-09-01

251

The edge of neutral evolution in social dilemmas  

Energy Technology Data Exchange (ETDEWEB)

The functioning of animal as well as human societies fundamentally relies on cooperation. Yet, defection is often favorable for the selfish individual, and social dilemmas arise. Selection by individuals' fitness, usually the basic driving force of evolution, quickly eliminates cooperators. However, evolution is also governed by fluctuations that can be of greater importance than fitness differences, and can render evolution effectively neutral. Here, we investigate the effects of selection versus fluctuations in social dilemmas. By studying the mean extinction times of cooperators and defectors, a variable sensitive to fluctuations, we are able to identify and quantify an emerging 'edge of neutral evolution' that delineates regimes of neutral and Darwinian evolution. Our results reveal that cooperation is significantly maintained in the neutral regimes. In contrast, the classical predictions of evolutionary game theory, where defectors ...

2009-09-15

252

The Optical Gravitational Lensing Experiment. Cepheids in the Galaxy IC1613 No Dependence of the Period--Luminosity Relation on Metallicity  

CERN Document Server

We present results of the search for Cepheids in the galaxy IC1613 carried out as a sub-project of the OGLE-II microlensing survey. 138 Cepheids were found in the 14.2x14.2 arcmin region in the center of the galaxy. We present light curves, VI photometry and basic data for all these objects, as well as color-magnitude diagram of the observed field. The Period--Luminosity (PL) diagrams for IC1613 fundamental mode Cepheids for VI and interstellar extinction insensitive index W_I are constructed. Comparison of PL relations in metal poor galaxy IC1613 ([Fe/H]~-1.0 dex) with relations in metal richer Magellanic Clouds allows us to study dependence of Cepheid PL relations on metallicity in the wide range of metallicities covered by these three galaxies. The slopes of PL relations in IC1613 are identical as in the Magellanic Clouds. The comparison of brightness of Cepheids with the magnitudes of the tip of the red giant branch stars and RR Lyr stars in all three objects ...

2001-01-01

253

The Magellanic Clouds Survey: a Bridge to Nearby Galaxies  

CERN Document Server

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

2009-01-01

254

THE RADIATION INDUCED OXIDATION AND REDUCTION REACTIONS OF IRON IN AQUEOUS SOLUTIONS. VII. THE DIRECT OBSERVATION OF REDOX PROCESSES IN THE IRRADIATED Fe-H$sub 2$SO$sub 4$-CARBOXYLIC ACIDS- H$sub 2$ -O$sub 2$ SYSTEM. THE EFFECTS OF THE STRUCTURE OF ACIDS  

Science.gov (United States)

The effects of the structure of a carboxylic acid on the processes of oxidation and reduction of iron ions in irradiated aqueous solutions were directly observed during irradiation. The solutions contained the mono- or dicarboxylic acid, H/sub 2/SO/sub 4/, Fe(NH/sub 4/)/sub 2/(SO/sub 4/)/sub 2/ and O/sub 2/. Th e ferrous oxidation was rather independent of the acid and its concentration, but the reduction of ferric was possible in the presence of formic, oxalic, or valeric acid only. The radical formed from the valeric acid acts similar to those formed from hydrocarbons. The G-values of oxidation and reduction of the iron ions were established. The molar extinction coefficients for oxalic and malonic complexes of ferric ions were determined. (auth)

1963-01-01

255

Synthesis, luminescence quantum yields, and lifetimes of trischelated ruthenium(II) mixed-ligand complexes including 3,3'-dimethy1-2,2'-bipyridyl  

International Nuclear Information System (INIS)

New five complexes of the type of [RuL sub(3-x)(dmby) sub(x)]X sub(2)(x = 1,2,3, L = 2,2'-bipyridyl or 1,10-phenanthroline, dmby = 3,3'-dimethy1-2,2'-bipyridyl, X = halide ion) have been synthesized in order to investigate the effects of two methyl groups of dmby on the absorption and emission spectra, luminescence quantum yields, and lifetimes. Values of the radiative and nonradiative rate constants have been calculated from these data at 77K. Although the absorption and emission maxima and the lifetimes are not much affected by the dmby ligand substitution, the molar extinction coefficients and emission quantum yields are decreased compared with trischelated complexes of the parent bipyridyl or phenanthroline ligands. At 25"0C the emission yields of the complexes containing dmby decrease by 3 - 4 orders of magnitude than at 77K. Possible causes of the decrease in the quantum yields are discussed. (author).

1982-01-01

256

Studies on some N-acyl N-phenylhydroxylamines as metal-complexing ligands - Part IX : formation constants of UO_2"2"+-complexes of some-hydroxysuccinamic acid  

International Nuclear Information System (INIS)

The first-step formation constants of UO_2"2"+-complexes of some N-hydroxysuccinamic acids viz. N-phenyl N-hydroxysuccinamic acid (Rsub(p)H(sub(2))), N-o-toyl N-hydroxysuccinamic acid(Rsub(t)oHsub(2)) and N-m-tolyl N-hydroxysuccinamic acid (Rsub(t)mHsub(2)) have been determined spectrophotometrically. Stabilities are in the ligand order Risup(m)Hsub(2)>Rsub(t)oHsub(2)>Rsub(p)Hsub(2). The first-step hydrolysis constant k' of UO_2"2"+ ion has been determined spectrophotometrically and found to be pk'=4.00 at a constant ionic strength (#mu#=0.5) at 30deg-+0.5deg and the molar extinction coefficients of the species UO_2"2"+ and UO_2(OH)"+ at #LAMBDA#=385 nm are found to be 2.0 and 13.0 respectively. (author).

1976-01-01

257

Spectrophotometric determination of vanadium(V) with 2-carbethoxy-5-hydroxy-1-(4-tolyl)-4-pyridone  

International Nuclear Information System (INIS)

Vanadium(V) in aqueous HCl, HNO_3 or H_2SO_4 solutions is extracted with 2-carbethoxy-5-hydroxy-1-(4-tolyl)-4-pyridone (HA) dissolved in CHCl_3 and determined spectrophotometrically, Depending on the composition of the aqueous phase, two complexes are formed. At pH 1 (HCl, HNO_3, H_2SO_4) VO_2A(HA)_2 is formed with maximal absorption at 478 nm. However, from 4-5 M HCl, VO_2Cl(HA)_3 is extracted, and has maximal absorption at 615 nm. The same complex is extracted from 2-3 M HNO_3 or 3-4 M H_2SO_4 if enough chloride is added. Solutions of both complexes follow Beer's law and the molar extinction coefficients are 4.15x10"3 1.mole"-"1cm"-"1 at 478 nm and 5.10x10"3 at 615 nm. The determination of vanadium at both wavelengths is very simple, fast and selective. The composition of the complexes was established by the usual methods as well as by characterization of the isolated crystalline compounds by elemental analysis and infrared spectroscopy. (author).

1975-01-01

258

Spectrophotometric determination of titanium and iron-application to Cherat volcanic ash, N.W.F.P  

International Nuclear Information System (INIS)

A rapid and sensitive method for the separation and determination of titanium and iron in thiocyanate system has been developed. The extractability of Ti(II) by high molecular weight (HMWA) in organic solvent (HCl/sub 3/) and its separation from Fe(III) was examined. The yellow coloured complex of Ti(II)-SCN in quantitatively extracted into the organic phase containing tribenzyl tribenzylamine (TBA) - a high molecular weight amine, whereas the blood red coloured complex of Fe(III)-SCN formed under the same conditions get separated in the aqueous phase. On the basis of the selective extractability, a method has been developed for the separation as well as simultaneous determination of Ti(II) and Fe(III) in presence of many other elements. The molar extinction coefficients were found to be 1.9 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ and 1.11 x 10/sup 5/ l mol/sup -1/ cm/sup -1/ respectively for Ti(II) and Fe(III). The extractability of the complex of fully applied to ...

1998-08-01

259

Planetpol polarimetry of the exoplanet systems 55 Cnc and tau Boo  

CERN Document Server

We present very sensitive polarimetry of 55 Cnc and tau Boo in an attempt to detect the partially polarised reflected light from the planets orbiting these two stars. 55 Cnc is orbited by a hot Neptune planet (55 Cnc e) at 0.038 AU, a hot Jupiter planet (55 Cnc b) at 0.11 AU, and at least 3 more distant planets. The fractional polarisation of this star is very stable, with a standard deviation in the nightly averaged Stokes Q/I and U/I parameters of 2.2x10^{-6}. We derive upper limits on the geometric albedo, A_G and planetary radius using Monte Carlo multiple scattering simulations of a simple model atmosphere. We assume Rayleigh-like scattering and polarisation behaviour (scaled by the maximum polarisation, p_m at 90 degrees) and pressure insensitive extinction. Atmospheres in which multiple scattering plays only a small role have an almost linear relation between polarisation and A_G. In this case, the 4 sigma upper limits are A_G<0.13(R/1.2 ...

2008-01-01

260

Oxidation kinetics of tetravalent uranium monofluoride complex by nitrous acid in HNO_3 medium  

International Nuclear Information System (INIS)

The kinetics of oxidation of uranium (IV) monofluoride complex by nitrous acid in nitric acid solution have been studied. The experiments were carried out at constant ionic strength of 2M (HNO_3 and NaNO_3) and temperature in the range of 18-47 deg C. The rate of reaction was determined spectrophotometrically at a wavelength of 621 nm, at which the molar extinction coefficients of UF"3"+ and UF_2"2"+ are the same. It was shown that reaction orders for [HNO_2] and [HNO_3] are equal to 0.12 and 0.39, respectively. The values of activation parameters #DELTA#H"#not =# and #DELTA#S"#not =# are determined to be 83 kJ mol"-"1 and 75 J (mol.K)"-"1, respectively. The rate order of the reaction studied has a weak direct depedence on [H"+] in contrary to the strong and reverse dependence in the absence of fluoride ions. In conclusion, fluoride ions may strongly stabilize the U(IV) in nitric acid solutions. (author) 4 refs.; 3 figs.; 2 tabs.

1991-08-01

261

Ongoing collapse of coral-reef shark populations.  

Science.gov (United States)

Marine ecosystems are suffering severe depletion of apex predators worldwide; shark declines are principally due to conservative life-histories and fisheries overexploitation. On coral reefs, sharks are strongly interacting apex predators and play a key role in maintaining healthy reef ecosystems. Despite increasing fishing pressure, reef shark catches are rarely subject to specific limits, with management approaches typically depending upon no-take marine reserves to maintain populations. Here, we reveal that this approach is failing by documenting an ongoing collapse in two of the most abundant reef shark species on the Great Barrier Reef (Australia). We find an order of magnitude fewer sharks on fished reefs compared to no-entry management zones that encompass only 1% of reefs. No-take zones, which are more difficult to enforce than no-entry zones, offer almost no protection for shark populations. Population viability models of whitetip and gray reef sharks project ongoing steep ...

2006-12-01

262

NGC 2770 - a supernova Ib factory?  

CERN Document Server

NGC 2770 has been the host of three supernovae of Type Ib during the last 10 years, SN 1999eh, SN 2007uy and SN 2008D. SN 2008D attracted special attention due to the serendipitous discovery of an associated X-ray transient. In this paper, we study the properties of NGC 2770 and specifically the three SN sites to investigate whether this galaxy is in any way peculiar to cause a high frequency of SNe Ib. We model the global SED of the galaxy from broadband data and derive a star-formation and SN rate comparable to the values of the Milky Way. We further study the galaxy using longslit spectroscopy covering the major axis and the three SN sites. From the spectroscopic study we find subsolar metallicities for the SN sites, a high extinction and a moderate star-formation rate. In a high resolution spectrum, we also detect diffuse interstellar bands in the line-of-sight towards SN 2008. A comparison of NGC 2770 to the global properties of a galaxy sample with high SN ...

2008-01-01

263

Kinetics of the stress induced phase transition in quartz by real-time neutron scattering  

International Nuclear Information System (INIS)

Complete text of publication follows. The stability regime of the incommensurate phase of quartz is influenced by uniaxial stress. Hence, the phase transition can be induced under isothermal conditions by the application of external mechanical forces. Using real-time neutron scattering the time evolution of structural changes is investigated id detail during stress variations. The time dependent behaviour of the satellite reflection is compared with that one of the fundamental Bragg reflection which - via primary extinction - gives information about the perfection of the crystal. On increasing stress the perfection of the lattice is destroyed immediately while the modulated structure is built up with a delay of about 1 s. Decreasing the stress leads to a reverse behaviour. Moreover, there is evidence that under periodical load residual non-relaxed strain fields survive leading to a different temperature dependence as compared to static conditions. This finding is ...

1999-09-01

264

Iridium and PGE in sedimentary rocks; Iridium et platinoides dans les roches sedimentaires  

Energy Technology Data Exchange (ETDEWEB)

The detection limit of Instrumental Neutron Activation Analysis (INAA), about a few microgram per kg, is not sufficient to determine iridium concentrations in most geological samples. Use of the coincidence counting of the 316 and 468 keV gamma-rays emitted during the decay of {sup 192}Ir, improved the sensitivity (0.01 microgram per kg). The high iridium content of the clay layers from the Cretaceous-Tertiary transition (KTB) has been considered as an evidence of the extra-terrestrial origin of the KTB mass extinction. However some results indicate that a significant part of the iridium content in sediments has a volcanic origin. Radiochemical Neutron Activation Analysis (RNAA) in some KTB samples and in basic and ultra-basic rocks show that, unlike in volcanic products, no PGE (platinoids) fractionation appears in KTB samples. The nearby chondritic PGE pattern supports an extra-terrestrial origin for the KTB iridium anomaly. 2 figs., 2 tabs., 37 refs.

1994-12-31

265

Identification of recharge sources and dating of groundwater using isotope and CFC techniques  

International Nuclear Information System (INIS)

Due to severe drought conditions in Pakistan over the past several years, most of the areas are facing extinction of its potable water reserves and inadequate replenishment of groundwater aquifers. Due to over exploitation, the groundwater flow dynamics is changing and water quality is degrading due to induced infiltration from polluted surface sources. Isotope hydrology is relatively a new discipline having great potential for studying various water-related problems. RIAD, PINSTECH has established analytical facilities for commonly used environmental isotopes and applied to investigate various hydrological problems. This paper briefly describes practical examples on recharge mechanism and dating of groundwater in Lahore and Ziarat areas using isotopes like deuterium (/sup 2/H), Oxygen-18 (/sup 18/O), Tritium (/sup 3/H) and CFCs in water. In Lahore, the areas having different contribution of the river Ravi in groundwater recharge have been marked and on the basis ...

2004-06-07

266

Extraction of copper-, nickel-, zinc- and cadmium complexes with 4-(2-pyridilazo)-resorcin and 2-aminopyridine  

International Nuclear Information System (INIS)

Extraction of copper-, nickel-, zinc- and cadmium complexes with 4-(2 pyridilazo)-resorcin (PAR) is studied in the presence of 2-aminopyridine (Am). Maximum optical densities of the extracts are attained at pH=7.5-8.0; 6.0-7.0; 6.5-7.0 and 7.0-8.0, respectively. The ratio of components in the complexes extractable by chloroform was defined by the method of isomolar series and equilibrium shift. It is established that nickel and copper are extracted to the organic phase as the NiAm(PAR)_2 and CuAmPAR complexes, and, in the case of zinc and cadmium, complexes of different composition are extracted, for example Zn(Am)_2PAR and ZnAm(PAR)_2. The light absorption spectra are studied and molar extinction coefficients of complex extracts are determined at lambdasub(max). It is shown that the general low of light absorption is observed within a sufficiently wide range of concentrations for all the elements.

1984-01-01

267

Ellipsometry studies on nitrogenated diamond-like carbon (DLC) thin films produced by RF magnetron sputtering  

International Nuclear Information System (INIS)

Nitrogen doped Diamond-like carbon thin films were deposited on n-Si and SiO_2 substrates by rf magnetron sputtering using pure graphite (99.999%) as the target material and mixtures of Ar, N_2 and H_2 for plasma generation. The dependence of structural and optical properties on nitrogen content was investigated using XPS, Raman spectroscopy, FT-IR spectroscopy, and Ellipsometry studies. It was found that as the nitrogen content was increased in the plasma, sp"2 bonding favored. Also it was observed that oxygen contamination increased with nitrogen content. Typical C-H stretching modes connected with diamond-like carbon could be seen in FT-IR spectra. The I_D and I_G bands were well defined and it was observed that as nitrogen content increased I_G band was enhanced. Ellipsometry studies revealed that the optical constants like refractive index (n) and extinction co-efficient (k) increased with increase in nitrogen content as well as substrate temperature. (author)

2003-03-01

268

Dynamics of HVDC system under unbalanced AC transmission line faults and its stabilization. Koryukei fuheiko kosho ni taisuru chokuryu keito no odo tokusei to anteika seigyo  

Energy Technology Data Exchange (ETDEWEB)

The application of HVDC system to the trunk power supply system requires the transmission of DC power as much as possible to improve the stability of the whole AC/DC system. To meet this requirement, continued pulse system, which keeps sending a DC current even when an AC voltage lowers remarkably, has been used. The stability is much more improved by adding damping control which modulates converter active and/or reactive power. In order to make full use of such control effects, it is important that the HVDC system maintains stable operation during faults and reclosing of the AC system. In particular, it is necessary to prevent a repetitive commutation failure following the unbalanced AC transmission line faults. In this paper, the cause of the repetitive commutation failure is discussed by using the AC-DC power system simulator developed by CRIEPI. Based on the analytical result, a stabilization control scheme with on-line extinction angle estimation is proposed, ...

1992-01-20

269

Dynamic complexities of a Holling II two-prey one-predator system with impulsive effect  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we investigate the dynamic behaviors of a Holling II two-prey one-predator system with impulsive effect concerning biological control and chemical control strategies-periodic releasing natural enemies and spraying pesticide (or harvesting pests) at fixed time. By using the Floquet theory of linear periodic impulsive equation and small-amplitude perturbation we show that there exists a globally asymptotically stable two-prey eradication periodic solution when the impulsive period is less than some critical value. Further, we prove that the system is permanent if the impulsive period is larger than some critical value, and meanwhile the conditions for the extinction of one of the two prey and permanence of the remaining two species are given. Finally, numerical simulation shows that there exists a stable positive periodic solution with a maximum value no larger than a given level. Thus, we can use the stability of the positive periodic solution and its ...

2007-07-15

270

Complex formation between neptunium (IV) and neptunium(V) with thiosemicarbazidodiacetic acid in solution  

International Nuclear Information System (INIS)

Complex formation between neptunium(IV) and neptunium(V) ions with thiosemicarbazidodiacetic acid in solution has been studied spectrophotometrically. Under the conditions employed herein complexes of composition 1:2 and 1:1, in the form Np(HR)_2 and NpO_2R"2"-, respectively, are formed. Stability constants for these complexes have been calculated and their molar extinction coefficients have been determined, and are equal to (1.33 +/- 0.25) x 10"7, log #beta# = 7.11 +/- 0.8, element of/sub K/ = 96 +/- 3 liter/mole x cm for Np(HR)_2, and (2.34 +/- 0.2) x 10"3, log #beta# = 3.36 +/- 0.036, element of/sub K/ = 235 +/- 1 liter/mole x cm for NpO_2R"2"-. Spectrophotometric titration has also shown that in basic solutions thiosemicarbazidodiacetic acid behaves as a tribasic acid; it third ionization constant has been determined and is equal to 10/sup -9.2/.

1988-01-01

271

Comparison of the performance of photonic band-edge liquid crystal lasers using different dyes as the gain medium  

Science.gov (United States)

The primary concern of this work is to study the emission characteristics of a series of chiral nematic liquid crystal lasers doped with different laser dyes (DCM, pyrromethene 580, and pyrromethene 597) at varying concentrations by weight (0.5-2 wt %) when optically pumped at 532 nm. Long-wavelength photonic band-edge laser emission is characterized in terms of threshold energy and slope efficiency. At every dye concentration investigated, the pyrromethene 597-doped lasers exhibit the highest slope efficiency (ranging from 15% to 32%) and the DCM-doped lasers the lowest (ranging from 5% to 13%). Similarly, the threshold was found to be, in general, higher for the DCM-doped laser samples in comparison to the pyrromethene-doped laser samples. These results are then compared with the spectral properties, quantum efficiencies and, where possible, fluorescence lifetimes of the dyes dispersed in a common nematic host. In accordance with the low thresholds and high slope efficiencies, the ...

2010-02-01

272

Atomistic analysis of defect evolution and transient enhanced diffusion in silicon  

International Nuclear Information System (INIS)

Kinetic Monte Carlo simulations are used to analyze the ripening and dissolution of small Si interstitial clusters and #left brace#113#right brace# defects, and its influence on transient enhanced diffusion of dopants in silicon. The evolution of Si interstitial defects is studied in terms of the probabilities of emitted Si interstitials being recaptured by other defects or in turn being annihilated at the surface. These two probabilities are related to the average distance among defects and their distance to the surface, respectively. During the initial stages of the defect ripening, when the defect concentration is high enough and the distance among them is small, Si interstitials are mostly exchanged among defects with a minimal loss of them to the surface. Only when defects grow to large sizes and their concentration decreases, the loss of Si interstitials through diffusion to the surface prevails, causing their dissolution. The presence of large and stable defects near the surface ...

2003-07-15

273

The German uranium miners cohort study (Wismut cohort), 1946-2003. Technical report  

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 ...

274

Relative correlation of Jet-REMPI monitoring with adsorption tube sampling followed by TDS-CIS-GC/MS  

Energy Technology Data Exchange (ETDEWEB)

During earlier work rapid and highly sensitive Jet-REMPI (resonance-enhanced multiphoton ionization) mass spectrometry was applied for monitoring the effluent from thermal treatment of a filter dust during a de novo test under laboratory conditions. The sample, from ESP-Field 2 of an iron ore sintering plant, was already loaded with dioxins ({sigma}PCDD/F = 132 ng/g), their precursors (PCBz, PCPh) and other products of incomplete combustion. Heating filter dust in a temperature window 200-350 C under a flow of air results in further formation of these pollutants. As described elsewhere, on-line detection was mostly carried out using a non-selective ionization mode, to measure a wide range of compounds simultaneously. The changes of output suggest that the reaction products increase in chlorination level with time. Another explanation is that higherchlorinated compounds appear later as a consequence of lower volatility and stronger adsorption. ...

2004-09-15

275

Probing the Early Stages of Low-Mass Star Formation in LDN 1689N: Dust and Water in IRAS 16293-2422A, B, and E  

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 ...

2004-01-01

276

Health hazard evaluation report No. HHE-80-033-815, Asarco, Inc. , Hayden, Arizona  

Energy Technology Data Exchange (ETDEWEB)

Worker exposures to arsenic (7440382) (As), cadmium (7440439) (Cd), copper (7440508) (Cu), lead (7439921) (Pb) and sulfur-dioxide (7446095) (SO2) were surveyed at ASARCO, Incorporated (SIC-3331) in Hayden, Arizona on April 23 and 24, 1980. The evaluation was requested by an authorized representative of the United Steel Workers, Local 886, on behalf of an unspecified number of workers. Personal and area air samples were collected in the pug mill department, and workers were tested for blood Pb and urinary As concentrations. All four personal samples for As exceeded the OSHA standard of 10 micrograms per cubic meter, one sample exceeded the Cu dust standard of 1 milligram per cubic meter (mg/cu m), and one sample exceeded the Pb standard of 50 micrograms per cubic meter. Exposures to Cd fume, Cd dust, and SO2 were below the respective OSHA standard of 0.2mg/cu m, 1.0mg/cu m, and 5 parts per million. One worker had a urinary As concentration that ...

1981-02-01

277

EVIDENCE FOR EVOLUTION AMONG PRIMORDIAL DISKS IN THE 5 Myr OLD UPPER SCORPIUS OB ASSOCIATION  

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, ...

2010-11-01

278

WR 104: Are We Looking Down The Gun Barrel of a Future GRB?  

Science.gov (United States)

WR 104 is the prototype for a small but growing group of stars that present the remarkably striking appearance of pinwheels. High resolution images of WR 104 show the (apparently) face-on spiral turning with an 8 month period. The pinwheel is assumed to be composed of dust produced via colliding winds in a low-inclination WR+OB binary. These assumptions have been very successful in modeling the imaging, but remain largely untested by spectroscopy. Strong motivation for further study of this system has emerged. Recent theory suggests that some gamma-ray bursts (GRB's) are core-collapse supernovae viewed nearly pole-on. The WC class Wolf-Rayet star in WR 104 is the type of star thought to be a possible GRB progenitor. If the orbit (and thus stellar rotation axes) are pole-on, the effects on Earth's biosphere could be significant. Confrontation of the face-on colliding-wind binary model with eight years of spectroscopy, offering full phase coverage of WR 104, is ...

2009-01-01

279

Use of neutron activation analysis for the control of air pollution of Algiers; Utilisation de l'analyse par activation neutronique pour le controle de la pollution de l'air d'Alger  

Energy Technology Data Exchange (ETDEWEB)

The urban zone needs clean air to assure public health. To achieve this goal several filter samples were collected in different sites in Algiers city. Toxic elements such as: Na, Mg, Cl, Sc, Cr, Ti, V, Fe, Co, Cu, Zn, Se, Br, Ag, Sb, Ce, La, Hf, Ta and Hg have been measured in the filters using neutron activation analysis technique. Irradiation of filter samples and standards were carried out in Es-Salem reactor. The experimental procedure and the results are discussed. We noted during this work that the upper limit values for suspended dusts and the high concentrations for some toxic elements found are due to the weather conditions and intense road traffic around collecting sites. (authors)

2010-07-15

280

Time-Resolved Aerosol Collector for CCSEM/EDX Single Particle Analysis  

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 non-volatile particles such as ammonium ...

2003-01-02

281

The Origin of Life from Primordial Planets  

CERN Document Server

The origin of life and the origin of the universe represent two of the most important problems of science. Both are resolved by hydro-gravitational dynamics (HGD) cosmology (Gibson 1996, Schild 1996, Gibson 2009ab), which predicts frozen primordial hydrogen-helium gas planets in clumps as the dark matter of galaxies. Merging Earth-mass planets formed stars, moons and comets to incubate and cosmically seed the first life. Cometary panspermia (Hoyle and Wickramasinghe 1981, 1982; Wickramasinghe et al. 2009) occurs naturally by HGD mechanisms. Comets and moons are fragments from mergers of stardust covered frozen gas planets in their step-wise growth to star mass. Supernovae from stellar over-accretion of planets produce stardust (C, N, O, P etc.) chemical fertilizer. Planets collect this infected radioactive dust gravitationally, to provide liquid water domains in contact with life nutrients seeded with life prototypes. The first mutating, evolving, life from HGD ...

2010-01-01

282

The Local Environment of the FUor-like Objects AR 6A and 6B  

CERN Document Server

We present new 12CO J=3-2 and HCN J=3-2 molecular line maps of the region surrounding the young star AR 6 using the 15 metre James Clerk Maxwell Telescope. AR 6 was previously found to be a double source with both components exhibiting several characteristics of FU Orionis (FUor) eruptive variable stars. Our data indicates that AR 6, like FU Orionis itself, does not possess a CO outflow and likewise, does not show evidence for large amounts of molecular g as in its circumstellar environment. We conclude that from the near-IR to the sub-mm, AR 6 is similar to FU Orionis in several respects. We interpret the lack of significant dust and molecular gas in the circumstellar environment of AR 6, together with the large near-IR thermal excess, as evidence that the sources have exhausted their natal envelopes, that they have at least small hot circumstellar disks, and that they are more evolved than Class I protostars. This, in itself, suggests that, since FUor eruptions ...

2008-01-01

283

Terrestrial Planet Formation in Extra-Solar Planetary Systems  

CERN Document Server

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational collapse from micron-sized dust grains in the thin disk midplane. Second, planetesimals coalesce to form Moon- to Mars-sized protoplanets, also called "planetary embryos". Finally, full-sized terrestrial planets accrete from protoplanets and planetesimals. This final stage of accretion lasts about 10-100 Myr and is strongly affected by gravitational perturbations from any gas giant planets, which are constrained to form more quickly, during the 1-10 Myr lifetime of the gaseous component of the disk. It is during this final stage that the bulk compositions and volatile (e.g., water) contents of terrestrial planets are set, depending on their feeding zones and the amount of radial mixing that occurs. The main factors that influence ...

2008-01-01

284

THE EVOLUTION OF CLOUD CORES AND THE FORMATION OF STARS  

International Nuclear Information System (INIS)

For a number of starless cores, self-absorbed molecular line and column density observations have implied the presence of large-amplitude oscillations. We examine the consequences of these oscillations on the evolution of the cores and the interpretation of their observations. We find that the pulsation energy helps support the cores and that the dissipation of this energy can lead toward instability and star formation. In this picture, the core lifetimes are limited by the pulsation-decay timescales, dominated by non-linear mode-mode coupling, and on the order of #approx =# few x 10"5-10"6 yr. Notably, this is similar to what is required to explain the relatively low rate of conversion of cores into stars. For cores with large-amplitude oscillations, dust continuum observations may appear asymmetric or irregular. As a consequence, some of the cores that would be classified as super-critical may be dynamically stable when oscillations are taken into account. Thus, ...

2010-09-20

285

Superfund Record of Decision (EPA Region 10): Commencement Bay Nearshore/Tideflats Site, operable unit 4, Ruston/North Tacoma Study Area, WA, June 1993  

Energy Technology Data Exchange (ETDEWEB)

This decision document presents the selected remedial action for the Ruston/North Tacoma Study Area, in Ruston and Tacoma, Washington. The EPA has divided the Commencement Bay/Nearshore Tideflats Superfund site into seven operable units (OU's) in order to facilitate the investigation, analysis, and cleanup of this very large site. Four of these OU's are associated with the Asarco smelter: OU 02 - Asarco Tacoma Smelter; OU 04 - Asarco Off-Property (Ruston/North Tacoma Study Area); OU 06 - Asarco Sediments; and OU 07 - Asarco Demolition. The remedy described in this ROD addresses OU 04 and involves the cleanup of arsenic and lead contaminated soils and slag in the Study Area, the residential community surrounding the smelter. This remedy will address the principal threat posed by conditions at the site, which is the ingestion of contaminated soil and dust.

1993-06-01

286

Stripping a debris disk by close stellar encounters in an open stellar cluster  

CERN Document Server

A debris disk is a constituent of any planetary system surrounding a main sequence star. We study whether close stellar encounters can disrupt and strip a debris disk of its planetesimals in the expanding open cluster of its birth. Such stripping would affect the dust production and hence detectability of the disk. We tabulated the fractions of planetesimals stripped off during stellar flybys of miss distances between 100 and 1000 AU and for several mass ratios of the central to passing stars. We then estimated the numbers of close stellar encounters over the lifetime of several expanding open clusters characterized by their initial star densities. We found that a standard disk, with inner and outer radii of 40 and 100 AU, suffers no loss of planetesimals around a star born in a common embedded cluster with star density 20 000 pc^-3. In this environment, a disk loses >97% of its planetesimals around an M-dwarf, >63% around a solar-type star, and >42% ...

2011-01-01

287

Silylation of low-density silica and bridged polysilsesquioxane aerogels  

Energy Technology Data Exchange (ETDEWEB)

Silica and bridged polysilsesquioxane aerogels are low-density materials that are attractive for applications such as thermal insulation, porous separation media or catalyst supports, adsorbents, and cometary dust capture agents. However, aerogels are notoriously weak and brittle making it difficult to handle and machine monoliths into desired forms. This complication prevents the development of many applications that would otherwise benefit from the use of the low-density materials. Here, we will describe our efforts to chemically modify and mechanically enhance silica-based aerogels using chemical vapor techniques without sacrificing their characteristic low densities. Monolithic silica and organic-bridged polysilsesquioxane aerogels were prepared by sol-gel polymerization of the respective methoxysilane monomers followed by supercritical carbon dioxide drying of the gels. Then the gels were reactively modified with silylating agents to demonstrate the viability ...

2004-01-01

288

Review of Central Research Institute of Electric Power Industry. Coal utilization technology harmonious with the environment. Kankyou ni yasashii sekitann riyo gijyutu. Kankyo ni yasashii sekitan riyo gijutsu  

Energy Technology Data Exchange (ETDEWEB)

Studies are made on coal in terms of its effective utilization, coal cleaning, fluidization and production of new fuel, and issues globally raised. Coal is abundant in reserves and high in supply stability and economic efficiency. However, it is much in CO2 emission per calorific value. To control as much CO2 emission as possible, effective utilization such as increasing of power generation efficiency has been proceeded with. In addition to ultra supercritical pressure and fluidized bed combustion, cited are coal gasification combined cycle power generation and high temperature type fuel cell. Coal has 5-20% ash and impurities like sulfur/nitrogen. Coal should be used clean by pollution abatement measures such as dust collecting, desulfurization and denitrification. Japan is at a world top level of these technologies. Coal is solid, and therefore, is more difficult to handle than liquid fuel. To use it easily, coal is liquefied into slurry such as COM and CWM, and ...

1994-04-25

289

Research and development of new coal based combined cycle power plant concept  

Energy Technology Data Exchange (ETDEWEB)

Out of concern for the global environment, technologies for coal-fired combined cycle power generation are under development throughout the world today, aiming at highly efficient use of coal. Under these circumstances, the authors and others, with the intention of producing a coal-fired combined cycle power generation system with higher plant efficiency, lower construction cost, and higher reliability than conventional systems, proposed a new gasification combined cycle power generation system that differs from the conventional IGCC system. The authors studied system configuration and conducted elementary research necessary for implementing the system. This report deals with the basic concepts of the system and the results of basic studies carried out to realize of the concepts, including a study on alkali metal vapour concentration in relation to heat corrosion; the relation between gas de-dusting temperature and gas alkali metal vapour concentration; and basic ...

1997-12-31

290

Problems of waste disposal in the handling of natural radioactive material not subject to authorisation  

International Nuclear Information System (INIS)

With the exception of some minerals, the specific activity of natural radioactive material is below 370 Bq/g, their handling thus not being subject to authorization or the duty of reporting according to section 4 para. 2 of the Radiological Protection Ordinance. Moreover, there is required no handling license for prospecting, mining and processing of radioactive minerals; they are subject to the procedures for the plans of operation of the mining laws of the Federal States. License-free handling of natural radioactive material may result in the production of radioactive waste, the disposal of which must be authorized according to sect. 47 of the Radiological Protection Ordinance if the specific activity exceeds the free amounts of column 4 in Table IV of Appendix IV by a factor of 10"-"4/g. This inconsistency is discussed by means of the following examples: (1) fly ash and slag from coal power plants, (2) flue dust from sintering plants, (3) red mud from aluminium ...

1980-05-01

291

Paleo-botanical evidence for ecosystem disruption at the Cretaceous-Tertiary boundary from Wood Mountain, Saskatchewan, Canada  

Energy Technology Data Exchange (ETDEWEB)

A continuous, subsurface Cretaceous-Tertiary boundary section, including the boundary clay within an 87 cm thick lignite, has been recovered from a core hole near Wood Mountain, Saskatchewan, Canada. The lignite-encompassed clay layer with geochemical anomaly indicates that peat deposition was continuous across the boundary. Core data indicate that, locally, a pre-boundary, conifer-dominated swamp was abruptly replaced by an angiosperm-dominated, herbaceous wetland. Sudden extermination of the dominant forest elements indicates mass kill at the level of the boundary and supports the theory of extraterrestrial impact accompanied by catastrophic destruction. Devastation of the standing vegetation may have been caused by one or more of the killing agents predicted to have accompanied impact, including freezing temperatures caused by atmospheric dust, acid rain, thermal pulse, and shock waves. There is no evidence supporting wildfires as a killing agent. Vegetational ...

1999-05-01

292

Mulled coal - a beneficiation coal form for use as a fuel or fuel intermediate. Technical progress report No. 9, April 1, 1992--June 30, 1992  

Science.gov (United States)

Under the auspices of the DOE and private industry, considerable progress has been made in: preparation of coal-water fuels; combustion of low-ash coal-based fuel forms; processes to provide deeply-cleaned coal. Developments in advanced beneficiation of coal to meet stringent requirements for low ash and low sulfur can be anticipated to further complicate the problem areas associated with this product. This is attributable to the beneficiated coal being procured in very fine particles with high surface areas, modified surface characteristics, reduced particle size distribution range, and high inherent moisture. Experience in the storage, handling, and transport of highly beneficiated coal has been limited. This is understandable, as quantities of such product are only now becoming available in meaningful quantities. During this reporting period the authors have: developed a suite of empirical tests covering water retention, rewetting, mull stability, angle of repose, ...

1993-01-01

293

Microbeam analysis of heavy element phases in polished sections of particulate material -- An improved insight into origin and bioavailability  

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 computer controlled SEM techniques. In the ...

1996-12-31

294

Ly-alpha emitters: blue dwarfs or supermassive ULIRGs? Evidence for a transition with redshift  

CERN Document Server

The traditional view that Ly-alpha emission and dust should be mutually exclusive has been questioned more and more often, notably the observations of Ly-alpha emission from ULIRGs seems to counter this view. In this paper we seek to address the reverse question: How large a fraction of Ly-alpha selected galaxies are ULIRGs? Using two samples of 24/25 Ly-alpha emitting galaxies at z = 0.3/2.3 we perform this test, also including results at z = 3.1, and find that whereas the ULIRG fraction at z = 3.1 is very small, it systematically increases towards lower redshifts. There is a hint that this evolution may be quite sudden and that it happens around a redshift of z ~ 2.5. Measuring the infrared luminosities of the Ly-alpha emitters, we find that they are in the normal to ULIRG range in the lower redshift sample, whereas the higher redshift galaxies all have luminosities in the ULIRG category. The Ly-alpha escape fractions for these infrared bright galaxies are in the ...

2009-01-01

295

Investigation of natural radionuclides in selected NORM-samples  

International Nuclear Information System (INIS)

A programme has been initiated by the Coordinating Office for Monitoring of enhanced natural radioactivity of the Federal Office for Radiation Protection to investigate different kinds of sample materials with enhanced naturally occurring radioactivity (NORM) such as scales from oilfield and naturally gasfield pipes, blast furnace sludge and sinter dust from the production of pig iron, as well as bauxit and red mud from the production of aluminium oxide. The aim of these investigations is to find proper preparation and measuring methods which allow, in particular, a sample treatment with optimised effort combined with a reliable determination of the specific activities of the dominating radionuclides. Of particular interest is the method of gamma-ray spectrometry, since this method has been used for most of our studies of sample materials. Due to different compositions of calibration and NORM-samples, e.g. different densities, and the analysis of low-energy ...

2005-09-20

296

Investigating the complex X-ray spectrum of a broad-line 2MASS red quasar: XMM-Newton observation of FTM 0830+3759  

CERN Document Server

We report results from a 50 ks XMM-Newton observation of the dust-reddened broad-line quasar FTM 0830+3759 (z=0.413) selected from the FIRST/2MASS Red Quasar survey. For this AGN, a very short 9 ks Chandra exposure had suggested a feature-rich X-ray spectrum and HST images revealed a very disturbed host galaxy morphology. Contrary to classical, optically-selected quasars, the X-ray properties of red (i.e. with J-Ks> 1.7 and R-Ks> 4) broad line quasars are still quite unexplored, although there is a growing consensus that, due to moderate obscuration, these objects can offer a unique view of spectral components typically swamped by the AGN light in normal, blue quasars. The XMM-Newton observation discussed here has definitely confirmed the complexity of the X-ray spectrum revealing the presence of a cold (or mildly-ionized) absorber with Nh ~10^{22} cm^-2 along the line of sight to the nucleus and a Compton reflection component accompanied by an intense Fe K ...

2010-01-01

297

Indoor air quality and thermal comfort studies of an under-floor air-conditioning system in the tropics  

Energy Technology Data Exchange (ETDEWEB)

This paper reports thermal comfort and indoor air quality (IAQ) studies of an under-floor air-conditioning (UFAC) system in a hot and humid climate. Thermal comfort parameters were measured at pre-determined grid points within an imaginary plane to predict the air flow pattern of the supply air jet as well as to determine the occurrence of thermal stratification in the office space. Fanger's thermal comfort index was also computed to detect the occupants' thermal sensation. Besides, the concentration levels of dust and carbon dioxide were recorded with the intention to examine the quality of the indoor air. Statistical methods were applied to derive the relationship between air velocity and the other parameters as mentioned earlier. The main findings from the study revealed reasonable level of acceptability of IAQ associated with the UFAC system. However, occupants are likely to experience localised thermal discomfort near the supply diffusers due ...

2002-07-01

298

In-depth survey report of Early and Daniel Co. , Inc. , Louisville, Kentucky  

Science.gov (United States)

An in-depth industrial hygiene survey was conducted to evaluate worker exposures to phosphine during fumigation of grain at the Early and Daniel Co. grain elevator in Louisville, Kentucky. Stored grain was fumigated using aluminum phosphide. Aluminum-phosphide pellets were also added directly to the grain by the blender as it was poured into the storage containers. Local exhaust ventilation was used at points in the grain-moving system where grain dust was generated. Air samples were taken during full-shift periods at the breathing zone of the weighmaster, two bin floormen, and the blender. Area monitoring samples were also taken. If the operators spend considerable time in the vicinity of a bin which is being filled with grain, there is a likelihood of far greater exposure levels being noted. According to the author, further studies of the use of phosphide products at other elevators should be conducted to determine the effect of environmental and process ...

1986-09-01

299

In-depth industrial-hygiene survey report of the Bunge Corporation, Kansas City, Kansas  

Science.gov (United States)

Potential exposure of workers to phosphide was examined during an in-depth industrial hygiene survey at the Bunge Corporation, in Kansas City, Kansas, where the gas was used as a grain fumigant. During the study, 14 men were employed at the facility. Tablets of aluminum phosphide were added to the grain mass for fumigation. General dilution ventilation resulted from outside air entering the work areas through ventilation louvers; there was also a local-exhaust ventilation system. Air samples revealed that, when the fumigant dispensers were being filled, workers in the area had significant exposure. At the time of the survey the relative humidity in the facility was high, permitting the reaction to phosphide to occur more readily. The levels of phosphide and respirable dust were reasonably low in the elevators, suggesting that the ventilation system was adequate. The author recommends that workers filling the dispenser with the aluminum phosphide be required to wear ...

1986-09-01

300

IC 4767 (the X-galaxy) - the missing link for understanding galaxies with peanut-shaped bulges?  

International Nuclear Information System (INIS)

Photometric and kinematic observations of the peculiar S0 galaxy IC 4767, the X-galaxy, are presented. At various intensities the bulge of this galaxy looks like a normal spheroidal system with elliptical isophotes, a well-defined rectangle, and a peanut-shaped or X-shaped structure with components aligned at oblique angles to the major axis. The observations reveal a rapidly rotating inner disk of gas and dust which is nearly aligned with the major axis. The presence of gaseous emission alone suggests an accretion event. The stars in the outer regions of the X-component are rotating nearly as rapidly as the gas in the main disk, indicating that they are in relatively circular orbits. The five most prominent peanut-shaped bulges all have several nearby companions, evidence that the peanut deformity is due to interaction between galaxies. An analogy with the formation mechanism proposed for polar-ring galaxies suggests how an X-shaped component could develop from ...

1988-01-01

301

Homoclinic chaos in the dynamics of a general Bianchi type-IX model  

International Nuclear Information System (INIS)

The dynamics of a general Bianchi type-IX model with three scale factors is examined. The matter content of the model is assumed to be comoving dust plus a positive cosmological constant. The model presents a critical point of saddle-center-center type in the finite region of phase space. This critical point engenders in the phase space dynamics the topology of stable and unstable four dimensional tubes RxS"3, where R is a saddle direction and S"3 is the manifold of unstable periodic orbits in the center-center sector. A general characteristic of the dynamical flow is an oscillatory mode about orbits of an invariant plane of the dynamics which contains the critical point and a Friedmann-Robertson-Walker (FRW) singularity. We show that a pair of tubes (one stable, one unstable) emerging from the neighborhood of the critical point towards the FRW singularity have homoclinic transversal crossings. The homoclinic intersection manifold has topology RxS"2 and is ...

2002-04-15

302

Health-hazard evaluation report HETA 85-354-1872, Asarco, Denver, Colorado  

Science.gov (United States)

An evaluation was made of possible hazardous working conditions at the ASARCO Globe facility, Denver, Colorado. The facility was involved in the recovery of cadmium from baghouse dust, a waste byproduct of nonferrous smelters. A medical study of kidney function was conducted in 45 current or former cadmium production workers; results were compared to those for 35 hospital workers. Kidney abnormalities were more common and more severe in the cadmium workers than in the hospital workers. Abnormalities of proximal tubular function included reduced reabsorption of beta-2-microglobulin, retinol binding protein, calcium and phosphate. Glomerular dysfunction was evidenced as elevated serum creatinine. As length of exposure to cadmium increased, changes became more apparent in workers. No reversal of the conditions was noted in workers who had ceased to be exposed to cadmium some time before the study. The authors conclude that occupational overexposure to cadmium caused ...

1988-02-01

303

Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores  

CERN Document Server

Aims: The production of saturated organic molecules in hot cores and corinos is not well understood. The standard approach is to assume that, as temperatures heat up during star formation, methanol and other species evaporate from grain surfaces and undergo a warm gas-phase chemistry at 100 K or greater to produce species such as methyl formate, dimethyl ether, and others. But a series of laboratory results shows that protonated ions, typical precursors to final products in ion-molecule schemes, tend to fragment upon dissociative recombination with electrons rather than just ejecting a hydrogen atom. Moreover, the specific proposed reaction to produce protonated methyl formate is now known not to occur at all. Methods: We utilize a gas-grain chemical network to probe the chemistry of the relatively ignored stage of hot core evolution during which the protostar switches on and the temperature of the surrounding gas and dust rises from 10 K to over 100 K. During this ...

2006-01-01

304

Discovery of a strong Baldwin effect in mid-infrared AGN lines  

CERN Document Server

We present the discovery of a Baldwin effect in 8 nearby Seyfert galaxies for the three most prominent mid-infrared forbidden emission lines observable from the ground that are commonly found in AGN, [ArIII](8.99 micron), [SIV](10.51 micron), and [NeII](12.81 micron). The observations were carried out using the VLT/VISIR imager and spectroraph at the ESO/Paranal observatory. The bulk of the observed line emission comes from the inner <0.4 arcsec which corresponds to spatial scales <100 pc in our object sample. The correlation index is approximately -0.6 without significant difference among the lines. This is the strongest anti-correlation between line equivalent width and continuum luminosity found so far. In the case of Circinus, we show that despite the use of mid-infrared lines, obscuration by either the host galaxy or the circumnuclear dust torus might affect the equivalent widths. Given the small observed spatial scales from which most of the line ...

2008-01-01

305

Decontamination factor of air filter against /sup 198/Au aerosol particles  

Energy Technology Data Exchange (ETDEWEB)

DF (decontamination factor) of two types of air filter was investigated against /sup 198/Au aerosol particles with AMAD (activity median aerodynamic diameter) = 1.2 ..mu..m and sigmag (geometric standard deviation) = 2.0. One of the filters, SO filter, is HEPA (high efficiency particulate air) filter media with 46 mmphi, and the other is HE-40T (cellulose-glass fiber filter for dust sampling) filter media with 40 mmphi. DF of the SO filter was found to be over 5 x 10/sup 4/ at air flow rate of 1 lmin. 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 filter and size distribution function of ...

1987-12-01

306

Decontamination factor of air filter against "1"9"8Au aerosol particles  

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 filter and size distribution function of ...

307

Collection and analysis of particulate from the DIII-D Tokamak  

International Nuclear Information System (INIS)

Particulate (i.e. tokamak dust) has been collected from the DIII-D tokamak located at General Atomics in San Diego, CA, USA. Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Sampling was completed in four toroidal locations of the machine; the 0-90 area, the 90-180 area, the 180-270 area, and the 270-360 area. The 0 direction designates the north side of the DIII-D machine. Four tiles in each area were sampled; the first vertical tile above the floor on the centerpost, a floor tile next to the center post, a tile on the isolated ring, and the first tile up from the isolated ring on the divertor. In addition, samples were collected from underneath the floor tiles at the 275 and the 75 locations. The count median diameter of the ...

1998-09-01

308

Coal power stations in 2000/2015; Kohlenkraftwerke im Jahr 2000/2015  

Energy Technology Data Exchange (ETDEWEB)

Developments in the past 10 -15 years in the fiels of `steel`, `boilers`, `steam turbines` and `environmental protection` show that the advanced coal dust furnace technology is another option of clean coal technology. The contribution discusses some of the current problems facing the main partners of the coal sector, e.g. coal producers, public utilities and suppliers of steel, boilers and turbines. (orig./GL) [Deutsch] Die Entwicklung der vergangenen 10-15 Jahre in den Bereichen `Stahl`, `Kessel`, `Dampfturbinen` und `umweltschutztechnische Anlagen` verdeutlicht, dass die fortgeschrittene Kohlestaubfeuerungstechnologie ebenfalls eine Option der `Clean Coal Technologies` ist. Im Rahmen dieses kurzen Aufsatzes wird nun versucht, einige zeitgemaesse Problemkreise der Hauptakteure des Strommarktes, wie z.B. des Kohlefoerderers, der Stromproduzenten und der Stahl-, Kessel- sowie Turbinenhersteller anzudeuten. (orig./GL)

1996-12-31

309

COLLISIONAL AND LUMINOSITY EVOLUTION OF A DEBRIS DISK: THE CASE OF HD 12039  

International Nuclear Information System (INIS)

Extrasolar debris disks that are bright enough to be observed are dense enough to be collision-dominated; i.e., the small grains that produce their infrared excess have collisional lifetimes shorter than their Poynting-Robertson decay times. This paper describes a numerical code for the modeling of such disks, including accretion and gravitational stirring as well as disruptive collisions. A constraint relating the mass of a debris disk and the sizes of the largest embedded bodies to its luminosity is demonstrated. The collisional code is applied to the debris disk around HD 12039, which has been intensively observed by the Spitzer Space Telescope. The evolution in time of the disk's luminosity is computed for a range of initial disk masses and planetesimal sizes. The luminosity at a given age depends on both the initial disk mass and the initial size of the planetesimals. Luminosity decays more rapidly for massive disks due to the combination of collisional depletion of small bodies ...

2010-10-20

310

Application of fluidized-bed combustion plants in the field of energy technology; Einsatz von Wirbelschichtfeuerungsanlagen in der Energietechnik  

Energy Technology Data Exchange (ETDEWEB)

In the future fossil fuelled power plants are realised/laid down as combined cycle power plants with high current generation efficiencies. The method of pressure fluidized-bed combustion with downstream hot gas cleaning is going to compete with methods combined with a pressure coal gasification or a pressure dust combustion. The advantages of the pressure fluidized bed combustion are the simpler method set-up and consequently lower investment costs. (orig./CD) [Deutsch] Kohlegefeuerte Kraftwerke werden zukuenftig als kombinierte Gas/Dampfturbinen-Kraftwerke mit hohen Stromerzeugungswirkungsgraden ausgefuehrt werden. Das Verfahren der Druckwirbelschichtverbrennung mit nachgeschalteter Heissgasreinigung und Rauchgasturbine wird dabei mit Verfahren mit einer vorgeschalteten Kohledruckvergasung oder mit einer Druckstaubfeuerung konkurrieren. Die Vorteile der Druckwirbelschichtverbrennung liegen dabei auf dem insgesamt einfacheren Verfahrensaufbau und damit wohl auch ...

1993-12-31

311

ARIES-AT safety design and analysis  

Energy Technology Data Exchange (ETDEWEB)

ARIES-AT is a 1000 MWe 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 the design from the safety perspective and gives additional confidence that the facility can meet the no-evacuation requirement under average weather conditions. We also provide ...

2006-01-15

312

ARIES-AT safety design and analysis  

International Nuclear Information System (INIS)

ARIES-AT is a 1000 MWe 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 the design from the safety perspective and gives additional confidence that the facility can meet the no-evacuation requirement under average weather conditions. We also provide ...

2006-01-01

313

A Remarkable Low-Mass X-ray Binary within 0.1 pc of the Galactic Center  

CERN Document Server

Recent X-ray and radio observations have identified a transient low-mass X-ray binary (LMXB) located only 0.1 pc in projection from the Galactic center, CXOGC J174540.0-290031. In this paper, we report the detailed analysis of X-ray and infrared observations of the transient and its surroundings. Chandra bservations detect the source at a flux of F_X = 2e-12 erg cm^-2 s^-1 (2-8 keV). After accounting for absorption both in the interstellar medium and in material local to the source, the implied luminosity of the source is only L_X = 4e34 erg/s (2-8 keV; D=8 kpc). However, the diffuse X-ray emission near the source also brightened by a factor of 2. The enhanced diffuse X-ray emission lies on top of a known ridge of dust and ionized gas that is visible infrared images. We interpret the X-ray emission as scattered flux from the outburst, and determine that the peak luminosity of CXOGC J174540.0-290031 was >2e36 erg/s. We suggest that the relatively small observed ...

2005-01-01

314

Energy from wood - part 3: automatic wood furnaces; Holzenergie, Teil 3: automatische Holzfeuerungen - Energie du bois, Partie 3: installations automatiques de chauffage au bois  

Energy Technology Data Exchange (ETDEWEB)

The paper gives an overview on the technologies and applications of automatic wood furnaces. The combustion systems are defined by the flow condition: With increasing gas velocity, fixed bed, stationary fluidized bed (SFB), circulating fluidized bed (CFB), and entrained flow reactors are distinguished. The furnace design and typical applications are described. Further, a comparison is presented which gives data of the typical size range and fuel types for the different combustion systems. The most common fixed bed reactors are under-stoker and grate furnaces. While under-stoker furnaces are applied in the size range from 20 kW to 2.5 MW, grate furnaces cover the size range from a few 100 kW up to more than 50 MW. Under-stoker furnaces are well suited for wood fuel with low ash content, moderate water content and limited fuel size. Grate furnaces are also suited for fuel with high ash and water content and large fuel sizes. Hence grate furnaces are nowadays most common. Due to the ...

2001-07-01

315

The weak force and SETH: The search for Extra-Terrestrial Homochirality  

Energy Technology Data Exchange (ETDEWEB)

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality{emdash}SETH. Homochirality is probably a pre-condition for life, so a chiral influence may be required to get life started. We explain how the weak force mediated by the {ital Z}{sup 0} boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how the resulting small excess of the more stable enantiomer may be amplified to homochirality. Titan and comets are good places to test for emerging pre-biotic homochirality, while on Mars there may be traces of homochirality as a relic of extinct life. Our calculations of the PVED show that the natural L-amino acids are indeed more stable than their enantiomers, as are several key D-sugars and right-hand helical DNA. Thiosubstituted DNA analogues show particularly large PVEDs. L-quartz is also more stable than D-quartz, and we believe that further crystal counts ...

1996-07-01

316

Spectroscopic characterization of alkane radical cations: Pt. 1  

International Nuclear Information System (INIS)

Radical cations of various 3-methylalkanes (C_6-C_1_4) have been produced and stabilized by #gamma#-irradiation of the corresponding neutral compounds in saturated chlorofluorocarbon and perfluorocarbon matrices at 77 K. The perfluorocarbon matrices appeared more suitable for studies of the lighter radical cations, whereas the chlorofluorocarbon matrices were more suited for studies of the heavier radical cations; intermediary cations could be studied in both types of matrices. After irradiation, electronic absorptions associated with both the matrix and the alkane additive were observed. Pure spectra of the 3-methylalkane radical cations were obtained by difference spectrometry, after selective elimination of these cations by illumination. The electronic absorption spectra of the 3-methylalkane radical cations consist in all cases of a single broad absorption band. The spectral position of this band shifts to longer wavelengths with increasing chain length; the maximum of the ...

1989-01-01

317

Risk analysis for the resident bald eagles of the lower Columbia River  

Energy Technology Data Exchange (ETDEWEB)

The resident bald eagles of the lower Columbia River have lower productivity and higher contaminant levels than other bald eagles of the Pacific Northwest. The primary population stressors are believed to be habitat loss, human disturbance, p,p{prime}DDE, PCBs, dioxins and furans. The primary effect of habitat loss is to reduce the carrying capacity of the region for nesting sites, and the primary effects of human disturbance and contamination by organic compounds are to reduce productivity. The purpose of this study was to quantitatively evaluate the effects of all of, these potential stressors on the bald eagle population dynamics. A model of the population dynamics was developed. The model structure includes a physiologically-based toxicokinetic (PBTK) submodel to estimate the degree of contamination, which is linked via a toxicology submodel to a population dynamics submodel. The PBTK submodel is time-variable, incorporating species-specific bioenergetics, as well as contaminant ...

1995-12-31

318

Pulse radiolysis of aqueous solutions of tetraphenylphosphonium ions  

International Nuclear Information System (INIS)

The reactions of tetraphenylphosphonium ion (Ar_4P"+) with esub(aq)"-, H atoms and OH radicals have been investigated. The absorption spectra of three transient species were obtained. Ar_4Psup(.) radicals formed by the reaction: Ar_4P"+ + esub(aq)"- #-># Ar_4Psup(.) have a maximum absorption at 305 nm [epsilon _3_0_5 = (9400 +- 300)dm"3mol"-"1cm"-"1] and decays by second-order kinetics with the rate constant 2k = (2.7 +- 0.4) x 10"9dm"3mol"-"1s"-"1. H atoms and OH radicals form transient adducts to the phenyl groups of the Ar_4P"+ ion with the rate constants of (1.5 +- 0.3) x 10"9 dm"3mol"-"1s"-"1 and (3.0 +- 0.3) x 10"9dm"3mol"-"1s"-"1, respectively. Both adducts have broad absorption spectra at 300 approximately 380 nm (lambdasub(max) = 340 nm) with the molar extinction coefficients epsilonsub(340) = 5400 +- 300 dm"3mol"-"1cm"-"1 for the H adduct and epsilonsub(340) = 3500 +- 200 dm"3mol"-"1cm"-"1 for the OH adduct. (author).

1976-01-01

319

Optical properties of crystalline and non-crystalline iron oxide thin films deposited by spray pyrolysis  

International Nuclear Information System (INIS)

Crystalline and non-crystalline iron oxide (#alpha#-Fe_2O_3) thin films were obtained by spray pyrolysis onto glass substrate at different temperatures. The results of X-ray diffraction showed that with increasing the deposition time, the film structure changed from non-crystalline to crystalline at the same substrate temperature. At different substrate temperatures and low deposition times (5 min), iron oxide appears almost in non-crystalline form. With rising the substrate temperature and deposition time, the crystallinity was improved. The effect of substrate temperature as well as deposition time on the optical features (absorption coefficient and bandgap) and optical constants of these films has been investigated. Optical constants of the films were determined from spectrophotometric measurement of reflectance and transmittance. Analysis of the results showed that, for non-crystalline iron oxide films of different thicknesses (76-118 nm) deposited at deposition time 5 min at a ...

2004-06-30

320

Nonhuman primates will not respond to turn off strong 60 Hz electric fields  

Energy Technology Data Exchange (ETDEWEB)

Using a set of six baboons (Papio cynocephalus), the authors conducted a series of seven experiments designed to evaluate the potentially aversive character of a 60 Hz electric field (EF). Initially, the subjects were trained, using food rewards as the reinforcer, to respond only when a cue light was illuminated. Next, an EF was presented along with the cue light; responses produced delivery of a food pellet and turned off both the cue light and the EF. Then, stimulus and reward conditions were varied. The authors determined that (1) presence of a strong EF does not affect operant responding for food rewards, (2) subjects will not respond at normal rates when the only reinforcer is termination of a strong EF, (3) presence of a strong EF can serve as a discriminative stimulus, (4) presence of a strong EF does not affect extinction of an appetite-motivated task, and (5) presentation of an EF can become a secondary reinforcer. The pattern of results was consistent ...

1995-12-31

321

Influence of cobalt doping on the crystalline structure, optical and mechanical properties of ZnO thin films  

International Nuclear Information System (INIS)

Uniform and transparent thin films of Zn_1_-_xCo_xO (0 #=# 0.035, CoO (cubic) was detected as the secondary phase. Influence of Co addition on the volume fraction of grain boundaries has been interpreted. Increase in Co content in the range 0 #<=# x #<=# 0.10 led to quenching of near-band edge and blue emissions, decrease in band gap energy (E_g) from 3.36 eV to 3.26 eV, decrease in film thickness and refractive index and an increase in extinction coefficient of Zn_1_-_xCo_xO thin films. The change in nature of stress from compressive to tensile with lower to higher doping of Co is corroborative with the angular peak shift of (002) plane of ZnO lattice. An overall increase in microhardness of Zn_1_-_xCo_xO thin films up to x = 0.05 is attributed to change in microstructure and evolution of secondary phase and as the secondary phase separates out the overall stress is released leading to lowering of hardness after this concentration. Hall-Petch behavior is ...

2010-07-01

322

Hydroxo-species of uranium (VI) in aqueous media  

International Nuclear Information System (INIS)

The large degree of confusion and many contradictions which are evident in the literature regarding the dioxo-uranium(VI)-hydroxide system has prompted the re-investigation of the hydrolysis of UO_2"2"- in aqueous media. The hydrolysis reactions of the uranyl ion have been investigated by potentiometric (pH)-, spectrophotometric- and conductometric titrations of uranyl chloride solutions with sodium hydroxide solutions. In all these titrations two clearly defined endpoints were obtained, indicating the predominance in solution of only a limited number of species. From a consideration of all the experimentally obtained data the following set of species was proposed to be present in significant concentrations in the pH range 0 to 12: UO_2"2"-, (UO_2)_2(OH)_2"2"-, (UO_2)_2(OH)_3"- and (UO_2)_9(OH)_1_9"-. By using the proposed set of species, a mathematical model of the uranyl-hydroxo system was developed with which the titration curves obtained by all three techniques could succesfully be ...

1600-01-01

323

Ground-based remote sensing measurements of aerosol and ozone in an urban area: A case study of mixing height evolution and its effect on ground-level ozone concentrations  

International Nuclear Information System (INIS)

We have estimated the mixing height (MH) and investigated the relationship between vertical mixing and ground-level ozone concentrations in Seoul, Korea, by using three ground-based active remote sensing instruments operating side by side: micro-pulse lidar (MPL), differential absorption lidar (DIAL), and differential optical absorption spectroscopy (DOAS). The M H is estimated from MPL measurements of aerosol extinction profiles by the gradient method under convective conditions. Comparisons of the MHs estimated from MPL and radiosonde measurements show a good agreement (r"2 = 0.99). Continuous MPL measurements with high temporal and vertical resolution reveal the diurnal variations of the MH under convective conditions and the presence of a residual layer during the nighttime. Comprehensive measurements of ozone and aerosol by MPL, DIAL and DOAS during an high ozone episode (24-26 May 2000) in Seoul, Korea, reveal that (1) photochemical ozone production and ...

324

Gamma radiation effects at color, antioxidant capacity and fatty acid profile in peanut (Arachis hypogaea L.)  

International Nuclear Information System (INIS)

Irradiation is efficient at extinction fungi contamination in peanuts. Peanuts have high biologic value protein, minerals, vitamin E, complex B, and high concentration of lipids. The objective of this research is to evaluate the gamma irradiation effect on color, total phenolic, antioxidant activity, and fatty acid profile in peanuts (Arachis hypogaea L.). Cultivars IAC-Tatu ST and IAC-Runner 886 were submitted to gamma radiation with doses of 5.0; 7.5; 10.0, and 15.0 kGy and storage at room temperature. There was no significant difference in the color of IAC-Tatu ST. However, significant difference was found in the luminosity and Chroma in IAC-Runner 886. Total fenolics differed from the control with 33.27 mg.g-1 and treatment dose of 10.0 kGy with 58.60 mg.g-1 in IAC-Tatu ST. This parameter not had significant difference in IAC-Runner 886 and the control with 51.59 mg.g-1. The antioxidant activity did not present significant difference with a dose of 10.0 kGy, ...

2011-01-01

325

Extraction-spectrophotometric determination of terbium in its mixture with lanthanum  

International Nuclear Information System (INIS)

A spectrophotometric study of the extraction with isobutanol of rare-earth elements in the form of complexes with quinoilizarin and N-benzene-N-phenylhydroxylamine has been made. The purpose of the study is to find out whether this reaction can be used in determining the concentration of elements in the presence of other rare-earth elements. In determining the relationship between the pH and light absorption the pH of the solution is measured after the extraction. The extraction of complexes begins at pH approximately 4 and reaches a maximum at pH7-8 (for La) and pH6-9 (for Er). The complexes underge decomposition when pH of the solution increased. The composition of complex compounds is determined by spectrophotometric methods for isomolar series, molar ratios and from the slope of logarithmic plots. Under optimal conditions (pH7.5) aAd at the measured ratio of the component for each ion of rare-earth elements, the molar extinction coefficients are determined for ...

1975-01-01

326

Design of spacecraft thermal control materials on polyimide film; Polyimide film ni yoru uchuyo netsuseigyo zairyo no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

Two types of thermal control materials based on polyimide film UPILEX-R are designed. One of thermal control material R/Al is coated with Al on the back surface. The other of thermal control material TCC/R/Al is coated with transparent conductive coating on the font surface and is coated with Al on the balk surface. The solar absorptance is measured spectroscopically with an integrating sphere in the wavelength region of 0.26 - 2.50 {mu}m and the total hemispherical emittance is measured calorimetrically in the temperature range of -100-+100{degree}C for the present thermal control materials. To evaluate the space degradation of optical properties (refractive index, extinction coefficient, absorption coefficient) on UPILEX-R film and solar absorptance on thermal control materials, space environment simulation tests are performed on the ground with independent radiation and combined radiation by UV, electrons, and protons. An onboard simultaneous measurement ...

1996-01-20

327

Characterisation of thin films by phase modulated spectroscopic ellipsometry  

International Nuclear Information System (INIS)

A wide variety of thin film coatings, deposited by different techniques and with potential applications in various important areas, have been characterised by the Phase Modulated Spectroscopic Ellipsometer, installed recently in the Spectroscopy Division, B.A.R.C. The Phase Modulated technique provides a faster and more accurate data acquisition process than the conventional ellipsometry. The measured Ellipsometry spectra are fitted with theoretical spectra generated assuming an appropriate model regarding the sample. The fittings have been done objectively by minimising the squared difference (#chi#"2) between the measured and calculated values of the ellipsometric parameters and thus accurate information have been derived regarding the thickness and optical constants (viz, the refractive index and extinction coefficient) of the different layers, the surface roughness and the inhomogeneities present in the layers. Measurements have been done on (i) ion-implanted ...

2009-12-01

328

Institute of Toxicology. 1994 annual report on research and development; Institut fuer Toxikologie. Ergebnisbericht ueber Forschung und Entwicklung 1994  

Energy Technology Data Exchange (ETDEWEB)

The R and D activities of the institute focused on two major projects, ``Molecular and cellular environmental toxicology``, and ``Biophysics of multi-cellular systems``. For assessment of health risks emanating from the uptake of heavy metal compounds, work performed under the first mentioned project studies the formation of allergy-inducing metabolic products from membrane lipids, and the effects of related cellular signaling processes. These studies are accompanied by an approach to quantify and classify the toxicity of environmental organometallic compounds. Another major task is research into the pathogenesis of lung disease induced by dusts, gases, and gas-dust mixtures and the liberation of inflammatory agents by immunological cell reactions (alveolar macrophages). Atomic force microscopy is the tool used to visualize the related dynamic changes in bronchial cells. Studies for detection of the localisation and structure of the Fe-Mo ...

1995-12-31

329

State of the energy in Lebanon  

International Nuclear Information System (INIS)

The article describes the state of the energy in Lebanon. In 1996, Lebanon consumed 4647 Ktoe as a primary energy. 97% of this energy is imported mainly polluting oil products: 1623 Ktons fuel-oil, 1379 Ktons gasoline, 930 Ktons diesel, 200 Ktons coal, 124 Ktons LPG, 107 Ktons jet-fuel/Kerosene, 109 Ktons Asphaltic products. The remaining 3% of the energy consumption is renewable energy. As for production, the state owns two refineries which are not used anymore. The year 2000 plan includes an expansion project for the Tripoli refinery and an alternative plan for the Zahrani refinery. These refineries require a total investment in order to reach a production capacity of 50000 barrels a day. The article is a description of the pollution type sources and location in Lebanon. The combustion of the total energy produces yearly more than 15 Ktons of dust, 85 Ktons of SO_2, 40 Ktons of NOX and 3500 Ktons of CO_2. Another risk of pollution is due to spilling oil along the ...

1998-04-01

330

Sources of toxicity and exposure information for identifying chemicals of high concern to children  

International Nuclear Information System (INIS)

Due to the large number of chemicals in commerce without adequate toxicity characterization data, coupled with an ineffective federal policy for chemical management in the United States, many states are grappling with the challenge to identify toxic chemicals that may pose a risk to human health and the environment. Specific populations (e.g., children, elderly) are particularly sensitive to these toxic chemicals. In 2008, the Children's Safe Product Act (CSPA) was passed in Washington State. The CSPA included specific requirements to identify High Priority Chemicals (HPCs) and Chemicals of High Concern to Children (CHCCs). To implement this legislation, a methodology was developed to identify HPCs from authoritative scientific and regulatory sources on the basis of toxicity criteria. Another set of chemicals of concern was then identified from authoritative sources, based on their potential exposure to children. Exposure potential was evaluated by identifying chemicals detected in ...

2010-11-01

331

Short rotation coppice harvesting: an evaluation of the Salix Maskiner Bender III  

Energy Technology Data Exchange (ETDEWEB)

Version III of the Salix Maskiner ``Bender`` coppice harvester was used to successfully harvest 11.2 hectares of short rotation poplar and willow coppice in February 1997. On a wide range of typical UK crop and site conditions, the Swedish harvester was shown to have productivity rates ranging from 4.28 to 7.97 odt/smh. Based on a total system cost of Pound 81.26 per scheduled machine hour, the Bender III is able to produce wood chip for between Pound 10.20 and pound 18.97 per dry tonne. The variation in machine productivity is dependent on crop productivity and working method, emphasising the importance of site design in optimising system efficiency. In willow crops the wood chip produced by the Bender III contained a significant amount of material greater than 75mm in length. The bulk of the chips however, fell into the 5-45mm category with only a very limited amount of fine materials less than 5mm in length. The chips from poplar crops were more uniform with the majority of material ...

1997-12-31

332

SUBMILLIMETER ARRAY OBSERVATIONS TOWARD THE MASSIVE STAR-FORMING CORE MM1 OF W75N  

International Nuclear Information System (INIS)

The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with #approx#1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (#approx#0.6 M_s_u_n) and MM1b (#approx#1.4 M_s_u_n), located near the radio continuum sources VLA 2/VLA 3 and VLA 1, respectively. Within MM1b, two gas clumps were found to be expanding away from VLA 1 at about #+-#3 km s"-"1, as a result of the most recent star formation activity in the region. Observed molecular lines show emission peaks at two positions, MM1a and MM1b: sulfur-bearing species have emission peaks toward MM1a, but methanol and saturated species at MM1b. We identified high-temperature (#approx#200 K) gas toward MM1a and the hot core in MM1b. This segregation may result from the evolution of the massive star-forming core. In the very early phase of star formation, the hot core is seen through the ...

2010-11-10

333

Raman spectroscopic studies of carbon in extra-terrestrial materials  

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 measure of structure in ...

1990-04-01

334

Omega process for the use of substitute fuels; Waste energy: Omega-Verfahren zur Verwertung von Ersatzbrennstoffen  

Energy Technology Data Exchange (ETDEWEB)

Only about 25% of residue accumulating in the Federal Republic of Germany is currently used for the purposes of energy. This residue will be converted into fuel for power stations by the Omega process when the dumping of waste with a calorific value in excess of 5 MJ/kg is prohibited with effect from 2005. This oxygen melting process is suitable for the local use of substitute fuels. Waste is converted into a high-quality synthesis gas with a wide range of uses. The Omega process combines drying, thermal decomposition, gasification and melting of the material used in a single-stage process. This is now technologically possible for the first time by combining a metallurgical cupola furnace with a traditional gas producer. The highly-calorific synthesis gas produced by the Omega process can be used in block heat and power stations or as an industrial fuel gas, instead of natural gas. It is also suitable as a starting material for synthesising methanol. The gas is specifically processed ...

2003-03-01

335

Method and device for the graduated charging of finely-particulate solid substances into an industrial furnace. Verfahren und Vorrichtung zum dosierten Einfuehren feinkoerniger Feststoffe in einen Industrieofen  

Energy Technology Data Exchange (ETDEWEB)

The invention concerns a method for the graduated introduction of finely-particulate and especially pulverously-particulate solid substance, in particular coal dust, from a pressurised proportioning tank containing a supply of solid matter into an industrial furnace with several supply points, in particular a shaft furnace such as a blast furnace or a cupola furnace, the solid matter being conveyed to the individual supply points in a flow of carrier gas heavily charged with solid matter, through a separate transport line for each supply point, the carrier gas being conveyed to the lower end section of the proportioning tank in a current which causes a local loosening in the lower section of the supply of solid matter, with the transport lines opening into the loosened area, whilst the proportioning tank that contains the solid matter is weighed continuously, the actual weight of the proportioning tank being compared with the latter's target weight, the ...

1987-09-09

336

Mathematical modelling of ash deposition of dispersed fuels; Mathematische Modellierung des Mineralansatzverhaltens disperser Brennstoffe  

Energy Technology Data Exchange (ETDEWEB)

A numeric method for predicting mineral ash deposition in coal dust furnaces is presented which is based on a bidirectional working time coupling of thermodynamic calculation routines (ChemApp{sup TM}) with the commercial CFD code FLUENT{sup TM}. The deposition characteristics of particles and wall surfaces is assessed on the basis of evaluations of flow simulation parameters and results of thermodynamic calculations for the mineral matter contained in the fuel particles, taking into account the complete energy, momentum and mass exchange history of the ash and the mineral conversion. The models enables calculations of the gaseous release of mineral components (e.g. alkaline substances and chlorine) from ash during combustion and its distribution inside a combustion chamber. The method and model are validated using experimental data. (orig.) [German] In der vorliegenden Arbeit wird ein numerisches Verfahren beschrieben, mit dem die Ansatzbildung in ...

2003-07-01

337

Inhalation Exposure Input Parameters for the Biosphere Model  

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 ...

2004-09-10

338

Health-hazard evaluation report HETA 88-108-2146, Asarco New Market/Young Mines, Mascot, Tennessee  

Energy Technology Data Exchange (ETDEWEB)

In response to a request from the International Chemical Workers Union, Akron, Ohio, an investigation was made into possible hazardous working conditions at two American Smelting and Refining Company (SIC-1031) zinc mines (New Market and Young) in Mascot, Tennessee. Specifically, exposures to asbestos (1332214), silica (14808607), and diesel emissions were determined. At both mines overexposures were found to nitrogen-dioxide (10102440) (NO2) and coal-tar pitch volatiles. Twenty-four percent of the NO2 measurements taken were above the NIOSH recommended ceiling of 1 part per million (ppm), but none exceeded the Mine Safety and Health Administration's (MSHA) ceiling of 5ppm. Exposure to diesel particulates ranged from 0.24 to 1.06mg/cu m. None of the 52 respirable dust samples collected exceeded the calculated MSHA limits for free silica exposure. A medical evaluation was offered and 83 of the 400 current employees and one retired employee participated. ...

1991-10-01

339

Development of an incinerator using ceramic filters for low level radioactive solid waste treatment  

International Nuclear Information System (INIS)

This facility has treatment capacity of 12 kg/hr, and is equipped with a furnace, two ceramic filter chambers, each of which hangs inside the 36 ceramic filter elements having mean pore size of 44 #mu#m. Three series of experiments were performed during a period from October 1972 to August 1973. The first was measurement of the change of pressure drop of the primary and the secondary filters after an operation of 52 days (352 hours). The pressure drop of the primary filter did not change during the operation, but the secondary brought a fairly large increment, from 79 to 140 mmAq. The second was measurement of the after-burning effect of the primary filter for the soot and tar in the off-gas. Through the after-burning most of the soot was removed from the off-gas, though the tar was not perfectly taken off. At the secondary filter, some of the tar was burnt, but most of it was caught by the filter as aerosol. The third was measurement of decontamination factors of radioactivities of ...

340

Depleted uranium human health risk assessment, Jefferson Proving Ground, Indiana  

Energy Technology Data Exchange (ETDEWEB)

The risk to human health from fragments of depleted uranium (DU) at Jefferson Proving Ground (JPG) was estimated using two types of ecosystem pathway models. A steady-state, model of the JPG area was developed to examine the effects of DU in soils, water, and vegetation on deer that were hunted and consumed by humans. The RESRAD code was also used to estimate the effects of farming the impact area and consuming the products derived from the farm. The steady-state model showed that minimal doses to humans are expected from consumption of deer that inhabit the impact area. Median values for doses to humans range from about 1 mrem ({plus_minus}2.4) to 0.04 mrem ({plus_minus}0.13) and translate to less than 1 {times} 10{sup {minus}6} detriments (excess cancers) in the population. Monte Carlo simulation of the steady-state model was used to derive the probability distributions from which the median values were drawn. Sensitivity analyses of the steady-state model showed that the amount of ...

1994-04-29

341

DETECTION OF A PSEUDOBULGE HIDDEN INSIDE THE 'BOX-SHAPED BULGE' OF NGC 4565  

International Nuclear Information System (INIS)

Numerical simulations show that box-shaped bulges of edge-on galaxies are not bulges: they are bars seen side-on. Therefore, the two components that are seen in edge-on Sb galaxies such as NGC 4565 are a disk and a bar. But face-on SBb galaxies always show a disk, a bar, and a (pseudo)bulge. Where is the (pseudo)bulge in NGC 4565? We use archival Hubble Space Telescope H-band images and Spitzer Space Telescope 3.6 #mu#m wavelength images, both calibrated to Two Micron All Sky Survey K_s band, to penetrate the prominent dust lane in NGC 4565. We find a high surface brightness, central stellar component that is clearly distinct from the boxy bar and from the disk. Its brightness profile is a Sersic function with index n = 1.55 #+-# 0.07 along the major axis and 1.33 #+-# 0.12 along the minor axis. Therefore, it is a pseudobulge. It is much less luminous than the boxy bar, so the true pseudobulge-to-total luminosity ratio of the galaxy is PB/T = 0.06 #+-# 0.01, much ...

2010-06-01

342

Common environmental allergens causing respiratory allergy in India.  

Science.gov (United States)

Respiratory allergy affects all age groups but the children are the worst affected by the respiratory allergy. Bioparticles from different biological sources are the main cause of allergy. Pollen grains, fungal spores, insect and other materials of biological origin form the most important allergen load in the air. For the efficient diagnosis of the allergy and its effective treatment it is very important to know about the prevalence, seasonal and annual variations of aeroallergens of the area. India being the climatically diversed country, there is diversity in the flora and fauna of different parts of the country. Atmospheric surveys carried out in different parts of India reveal that, Alanus nitida, Amarantus spinosus, Argemone mexicana Cocos nucifera, Betula utilis, Borasus flabellifer, Caraica papaya, Cedrus deodara, Cassia fistula, Parthenium, Chenopodium album, Dodonaea viscosa, Malotus phillipensis, Plantago ovata, Prosopis juliflora, Ricinus communis, Holoptelea intergifolia ...

2002-03-01

343

Characterisation of dust material emitted during harbour operations (HADA Project)  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to compile an inventory of the main characteristics (chemical, morphological, mineralogical and grain size parameters) of the bulk cargo materials and of the material emitted during different port operations for possible use as tracers of the fugitive PM emission sources. For all cases, the tracer characteristics determined for each bulk material were also identified in the corresponding PM material emitted. This inventory could assist the harbour authorities to identify the origin of high PM events recorded by air quality monitoring networks in harbour areas, and could also help modellers to predict the impact of harbour activities on ambient PM levels. The harbour of Tarragona (north-east Spain) was selected for this study given the high volume of solids in bulk handled. To this end, 12 handling operations of selected materials (clinker, phosphate, pyrite ash, Mn mineral, fine Si-Mn, coke (coal), bituminous coal, tapioca, soybean, alfalfa, corn, andalusite) ...

2007-09-15

344

CT characterization of bile duct dilatation: Differential diagnosis of obstructive jaundice  

Energy Technology Data Exchange (ETDEWEB)

Each disease affecting the bile ducts tends to produce characteristic pattern of biliary dilatation: recurrent pyogenic cholangitis causes dilatation and straightening of the larger (central) intrahepatic ducts: clonorchiasis causes dilatation of the smaller (peripheral) intrahepatic ducts; and carcinoma along the extrahepatic ducts causes (proportional) dilatation and tortuosity of both larger and smaller intrahepatic ducts. To evaluate the specificity of the pattern and morphology of the dilated biliary tree on CT scans (CT characterization) three independent radiologists who were unifamiliar with the cases were asked to classify 62 CT scans in patients with obstructive jaundice. The case population consisted of 14 cases with recurrent pyogenic cholangitis, 18 cases with clonorchiasis and 30 cases with carcinoma along the extrahepatic ducts, which were intermixed randomly. Classification was made only on the basis of CT characterization: those scans showing primary lesions, i.t., ...

1992-07-15

345

CT characterization of bile duct dilatation: Differential diagnosis of obstructive jaundice  

International Nuclear Information System (INIS)

Each disease affecting the bile ducts tends to produce characteristic pattern of biliary dilatation: recurrent pyogenic cholangitis causes dilatation and straightening of the larger (central) intrahepatic ducts: clonorchiasis causes dilatation of the smaller (peripheral) intrahepatic ducts; and carcinoma along the extrahepatic ducts causes (proportional) dilatation and tortuosity of both larger and smaller intrahepatic ducts. To evaluate the specificity of the pattern and morphology of the dilated biliary tree on CT scans (CT characterization) three independent radiologists who were unifamiliar with the cases were asked to classify 62 CT scans in patients with obstructive jaundice. The case population consisted of 14 cases with recurrent pyogenic cholangitis, 18 cases with clonorchiasis and 30 cases with carcinoma along the extrahepatic ducts, which were intermixed randomly. Classification was made only on the basis of CT characterization: those scans showing primary lesions, i.t., ...

1992-07-01

346

Application of a computer model for optimisation of combustion and NO{sub x} abatement in a utility kraft recovery boiler  

Energy Technology Data Exchange (ETDEWEB)

The kraft recovery boiler is of critical importance for the paper and pulp industry. From only energy point of view, kraft recovery boilers supply more than 50% of total thermal energy consumed in the paper and pulp industry. A kraft recovery boiler has two main functions: firstly to recover the inorganic cooking chemicals in the black liquor for reuse in the pulping process, and secondly to make use of the chemical energy in the organic portion of the black liquor to generate super-heated steam for the plant. The twin objectives of recovering chemicals and energy makes the recovery boiler design and operation more complex than virtually any other boiler application. Thus there is a demand for development of an analytical tool that can be used to predict the performance of a kraft recovery boiler. This paper presents the results achieved from a project jointly financed by Swedish National Energy Administration and the industry (Iggesund Paperboard). In this project, a three-dimensional ...

2001-07-01

347

THE EVOLUTION OF THE STAR FORMATION RATE OF GALAXIES AT 0.0 #<=# z #<=# 1.2  

International Nuclear Information System (INIS)

We present the 24 #mu#m rest-frame luminosity function (LF) of star-forming galaxies in the redshift range 0.0 #<=# z #<=# 0.6 constructed from 4047 spectroscopic redshifts from the AGN and Galaxy Evolution Survey of 24 #mu#m selected sources in the Booetes field of the NOAO Deep Wide-Field Survey. This sample provides the best available combination of large area (9 deg"2), depth, and statistically complete spectroscopic observations, allowing us to probe the evolution of the 24 #mu#m LF of galaxies at low and intermediate redshifts while minimizing the effects of cosmic variance. In order to use the observed 24 #mu#m luminosity as a tracer for star formation, active galactic nuclei (AGNs) that could contribute significantly at 24 #mu#m are identified and excluded from our star-forming galaxy sample based on their mid-IR spectral energy distributions or the detection of X-ray emission. Optical emission line diagnostics are considered for AGN identification, but we find that 24 ...

2010-08-01

348

Present conditions in Greenland and the Kangerlussuaq area  

International Nuclear Information System (INIS)

Greenland is the world's largest island, with an area of 2.2 million square kilometres, 80 % of which is covered by the ice sheet. The climate is Arctic, but as Greenland stretches 2600 km from north to south, there is a huge variability in climate, with temperature decreasing from south to north. Due to the influence of oceanic currents, the west coast is slightly warmer than the east coast. Precipitation also decreases strongly from the south to the north, and also with distance from the coast. Kangerlussuaq is located in the dry, continental area of central west Greenland. The bedrock of Greenland is dominated by Precambrian gneisses, with sedimentary rocks occurring in some areas of East and North Greenland, and smaller areas of basalts. All of Greenland has been glaciated several times and has thus been eroded and shaped by the ice, as it still is at the ice margin. Soils are generally thin, and especially in the gneiss regions rather poor in plant nutrients. Permafrost occurs ...

349

Aerosol composition, chemistry, and source characterization during the 2008 VOCALS Experiment  

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 Cl- typically more than half the equivalency of Na+, and are ...

2010-03-15

350

Magnetic resonance imaging (MRI) of the central nervous system in long-term manganese dioxide (MnO{sub 2}) exposed workers; Magnetresonanztomographie des Gehirns bei Beschaeftigten mit chronischer beruflicher Mangandioxid-Exposition  

Energy Technology Data Exchange (ETDEWEB)

Aim: Changes within the brain detected by MRI after chronic manganese poisoning raised the question whether morphological changes of the basal ganglia, particularly of the globus pallidus, could be detected after chronic occupational exposure to manganese dioxide. Results: No cases of parkinsonism were detected in clinical examinations or by other means. The mean manganese concentration in blood was 12 {mu}g/l (range: 3.9-23.3 {mu}g/l). In comparison to the upper reference value of 10 {mu}g/l, 42 workers (56%) had a higher body burden. A significant positive correlation between manganese levels in blood and the PI (indicated by T{sub 1}-shortening) was observed as well as between the CBI and workplace-specific exposure. Brain atrophy was not detected in any of the observed cases. Conclusions: Long-term exposure to manganese dioxide dust correlates with the Pallidum-Index in MRI scans. Although the MRI findings have no current clinical relevance for individuals, ...

2000-06-01

351

HORIZON SENSING  

Energy Technology Data Exchange (ETDEWEB)

With the aid of a DOE grant (No. DE-FC26-01NT41050), Stolar Research Corporation (Stolar) developed the Horizon Sensor (HS) to distinguish between the different layers of a coal seam. Mounted on mining machine cutter drums, HS units can detect or sense the horizon between the coal seam and the roof and floor rock, providing the opportunity to accurately mine the section of the seam most desired. HS also enables accurate cutting of minimum height if that is the operator's objective. Often when cutting is done out-of-seam, the head-positioning function facilitates a fixed mining height to minimize dilution. With this technology, miners can still be at a remote location, yet cut only the clean coal, resulting in a much more efficient overall process. The objectives of this project were to demonstrate the feasibility of horizon sensing on mining machines and demonstrate that Horizon Sensing can allow coal to be cut cleaner and more efficiently. Stolar's primary goal was ...

2003-03-18

352

Feasibility study for new ecolabels for the product group: Wood pellet firings. Final report; Machbarkeitsstudie fuer neue Umweltzeichen fuer die Produktgruppe: Holzpelletfeuerungen. Endbericht  

Energy Technology Data Exchange (ETDEWEB)

This assessment is a feasibility study according to ISO 14024. It deals with the question whether an ecolabel is suitable for wood pellet heating systems and how concrete criteria for an ecolabel for wood pellet heating plants could be specified. The study begins with a comprehensive market analysis in order to identify possible plants for which an ecolabel would make sense. In the main part of the study, the environmental relevance of the chosen plants is analysed. For this analysis, plant manufacturers were interviewed and a comparison between wood pellet heating systems and heating systems which use gas, oil or wood was carried out. On the basis of this analysis, it was possible to derive a number of criteria which were discussed with company representatives and other experts in this field. As a result of this dialogue and the investigation process as a whole, the introduction of an ecolabel for wood pellet heating plants can be recommended. Wood pellet heating systems are ...

2002-07-01

353

A review of 4 norm industries in Ireland  

Energy Technology Data Exchange (ETDEWEB)

Full text: This presentation will review the progress achieved so far by the Irish national regulatory agency, the Radiological Protection Institut e of Ireland (R.P.I.I.) in the investigation of work activities where the presence of natural radiation sources (NORM) could lead to a significant increase in exposure to workers or members of the public which cannot be disregarded from the radiation protection point of view. Since the coming into force in Ma y 2000 of the Radiological Protection Act, 1991 (Ionising Radiation) Order, 2000 (S.I. No. 125 of 2000) which implements the Eu B.S.S. Directive 96/29/EURATOM, four major NORM industries currently active in Ireland have been investigated. According to the literature, they are all considered liable to involve work practices resulting in exposure to NORM. They include: the gas extraction and production industry, the peat- and coal-firing power generation industry and the bauxite/alumina refining industry. For the gas industry, monitoring ...

2006-07-01

354

Traces of evidence. Nuclear forensics and illicit trafficking  

International Nuclear Information System (INIS)

An IAEA databank lists a number of reported cases of illicitly trafficked nuclear or other radioactive materials. Apart from the traditional concern with nuclear proliferation, the post September 11th public is now wary of a possible attack by terrorists with a nuclear or radiation dispersion device (RDD). Until now, the seized quantities have not been sufficient to manufacture a nuclear explosive device, but they might be enough to construct an RDD. Recognizing the latent global challenge to public health and safety, the G8 States (Japan, USA, Germany, France, UK, Italy, Canada, and Russia) have called for 'joint international efforts to identify and suppress illicit supply' of, and demand for, nuclear material and to deter potential traffickers. One measure gaining in significance is to identify seized material and trace it back to its origin the objective of an emerging science known as nuclear forensics. Repeatedly nuclear or other radioactive material of unknown origin are ...

2003-06-01