ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Mathematical modeling of high-power transferred arcs (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 7757-7767 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The behavior of an argon arc in a transferred arc furnace with a cold cathode and anode has been investigated using an elliptic model with emphasis on a high-current, long arc (L=100–200 mm, I=500 A). Conservation equations for the laminar arc column are written assuming local thermodynamic equilibrium. The governing equations are solved by employing an efficient finite difference method. The anode is included in the calculation domain. Numerical calculations performed for a transferred argon arc show good agreement with temperature measurements obtained by emission spectroscopy. The results also indicate that, except in regions close to the anode, the arc behavior is parabolic. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357953
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Mathematical modeling of a free-burning arc in the presence of metal vapor (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 3065-3070 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The transfer of energy between the plasma and the iron anode and the evaporation of metal were taken into account in modeling a short free-burning arc in argon at atmospheric pressure. The presence of metal vapor in the plasma modifies the electrical conductivity and the radiated power and leads to arc cooling in the anode region. In return, the arc cooling modifies the rate of vaporization of the anode and thus the calculated concentration of iron vapor in the arc.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354624
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Effect of the presence of iron vapors on the volumetric emission of Ar/Fe and Ar/Fe/HZ plasmas (1994)
    Springer
    Plasma chemistry and plasma processing 14 (1994), S. 301-315 
    Details
    ISSN: 1572-8986
    Keywords: Volumetric emission ; argon plasma ; iron emission ; atmospheric plasma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The net volumetric emission coefficient was calculated using the escape factor method for Ar/Fe and Ar/H2/Fe plasmas, at atmospheric pressure, over the temperature range from 3000 K to 30,000 K. The calculation involved 712 lines for Ar I, Ar II, and Ar III, 3481 lines for Fe I, Fe II, and Fe III, and 230 lines for H in the Ar/H2/Fe case. A semiempirical method was used for the determination of line profiles and line broadening. The results show a strong influence of the presence of even traces of iron vapors at low temperatures where the volumetric emission increases by several orders of magnitude. Special attention is given to self-absorption of the argon resonance lines which prevents the radiation from escaping within a few millimeters from the emission source.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01447083
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Acute toxicity of organophosphorus and organochlorine insecticides in laboratory animals (1979)
    Springer
    European journal of nutrition 18 (1979), S. 258-268 
    Details
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Notes: Summary The influence of acute poisoning with Dursban (O.P.I.) and D.D.T. (O.cl.I.) on serum enzymes and histopathological examination of the liver, kidney and testes was investigated in albino rats. Two repeated i.p. injections of Dursban in a dose of half the LD 50 resulted in a significant increase in serum GOT, GPT and alkaline phosphatase activity and a decrease of cholinesterase. In case of DDT, two doses of 150 mg/kg orally resulted in a significant increase in the activity of serum GPT only, while three doses increased serum GOT and GPT. No significant change was observed in serum alkaline phosphatase and cholinesterase activity. Regarding the pathological examination it was found that in animals treated with Dursban there was liver necrosis of mid-zonal type and fatty change at the periphery. In case of DDT the liver cells lost their radial arrangements and showed fatty change. There was cellular infiltration in the centre, mostly mononucleolar cells. In both insecticides there was necrosis of some of the seminiferous tubules of the testes and cloudy swelling of the convoluted tubules of the kidney. Histochemical study of the liver in animals treated with Dursban showed that glycogen was deposited at one side of the cell. However, there was depletion of glycogen around the central vein. In liver treated with DDT there were large globules of fat inside the liver cells, indicating increased fat content compared to control liver, where there were tiny minute droplets of fat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02020516
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Volumetric emission of argon plasmas in the presence of vapors of Fe, Si, and Al (1994)
    Springer
    Plasma chemistry and plasma processing 14 (1994), S. 437-450 
    Details
    ISSN: 1572-8986
    Keywords: Volumetric emission ; argon plasma ; metal vapors ; iron ; aluminum ; silicon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract The net volumetric emission was calculated for argon plasmas at atmospheric pressure in the presence of metal vapors for different elements, over the temperature range from 3000 to 30,000 K. The computations are based on the escape factor model, using a semi-empirical method for the determination of line profiles and line broadening effects. Results for iron, .silicon, and aluminum show an important influence of the presence of even the smallest concentrations of the metal vapors on the net emission coefficient of the plasma. The effect is strongest for iron, followed by aluminum and .silicon. Special attention is given to self-absorption effects which are most important in the first millimeter o% the optical path of the emitted radiation. The effect is incorporated into the calculation procedure of the net emission coefficient and can be used as a volumetric energy sink as long as the absorption length is shorter than the radius of the control volume used in the computation scheme.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01570206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The induction plasma chemical reactor: Part I. Equilibrium model (1990)
    Springer
    Plasma chemistry and plasma processing 10 (1990), S. 133-150 
    Details
    ISSN: 1572-8986
    Keywords: Induction plasma ; modeling ; chemical equilibrium ; silicon nitride synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract A mathematical model is presented for the numerical simulation of the flow, temperature, and concentration fields in an rf plasma chemical reactor. The simulation is performed assuming chemical equilibrium. The extent of validity of this assumption is discussed. The system considered is the reaction of SiCl4 and NH3 for the production of Si3N4.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01460452
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The induction plasma chemical reactor: Part II. Kinetic model (1990)
    Springer
    Plasma chemistry and plasma processing 10 (1990), S. 151-166 
    Details
    ISSN: 1572-8986
    Keywords: Induction plasma ; modeling ; chemical kinetics ; dissociation of silicon tetrachloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Technology
    Notes: Abstract A kinetic model has been developed for the prediction of the concentration gelds in an rf plasma reactor. A sample calculation for a SiCl4/H2 system is then performed. The model considers the mixing processes along with the kinetics of seven reactions involving the decomposition of these reactants. The results obtained are compared to those assuming chemical equilibrium. The predictions indicate that an equilibrium assumption will result in lower predicted temperature fields in the reactor. Furthermore, for the chemical system considered here, while differences exist between the concentration fields obtained by the two models, the differences are not substantial.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01460453
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Deposition from the vapour phase during induction plasma treatment of alumina powders (1993)
    Springer
    Journal of materials science 28 (1993), S. 4223-4228 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A study was carried out of the induction plasma melting of alumina powders (particle mean diameter, ¯d p=24.5 μm), (Ar/H2 or Ar/N2 plasma, plate power, 40 kW) under reduced pressure conditions (400 torr). The results reveal that in the process, partial vaporization of the alumina powders takes place in the hot region of the discharge. As the molten particles cool down and solidify, the deposits from the vapour phase was formed with the spheroidized particles. In all treatments with the Ar/H2 and Ar/N2 plasmas, a condensate of ultrafine alumina fume (d p〈200 nm) was obtained. The fine particles consisted essentially of metastable γ-, δ- and θ-phases. Needle-like crystals(0.1–0.3 μm diameter, by 5–15 μm long) were observed when operating with an Ar/N2 plasma at powder feed rates exceeding 10 g min−1. Electron diffraction analysis revealed that the needles were whiskers, whose structure was very similar to κ- or χ-aluminas with an hexagonal close-packed oxygen lattice. The change of morphology is related to the degree of supersaturation in the vapour phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00351258
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    facet.materialart.
    Unknown
    Mathematical modeling of high‐power transferred arcs (1994)
    American Institute of Physics
    Details
    Publication Date: 1994-12-15
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Published by American Institute of Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Acute toxicity of organophosphorus and organochlorine insecticides in laboratory animals (1979)
    Springer
    Details
    Publication Date: 1979-12-01
    Print ISSN: 0044-264X
    Electronic ISSN: 1435-1293
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...