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
Filter
  • ASTROPHYSICS  (318)
  • Chemical Engineering  (160)
  • 2005-2009
  • 1985-1989  (258)
  • 1980-1984  (220)
  • 1985  (258)
  • 1983  (220)
Collection
Keywords
Publisher
Years
  • 2005-2009
  • 1985-1989  (258)
  • 1980-1984  (220)
Year
  • 1
    facet.materialart.
    Unknown
    Hydrogen-deficient atmospheres for cool carbon stars (1985)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Motivated by recent work which hints at a possible deficiency of hydrogen in non-Mira N-type carbon stars and to further explore the parameter space of chemical composition, computations have been made of a series of hydrogen-deficient models for carbon stars. For these models Teff = 3000 K, and log g = 0.0. Solar abundances are used for all elements except for carbon (which is enhanced to give C/O = 1.05), hydrogen, and helium. As the fractional abundance of hydrogen is decreased, being replaced by helium, the temperature-optical depth relation is affected only slightly, but the temperature-pressure relation is changed. The most striking change in the emergent flux is the decrease of the H(-) peak at 1.65 micron compared with the blackbody peak at 1.00 micron.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 292; 228-230
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    Electronic Resource
    Electronic Resource
    Mixing studies in the single screw extruder (1985)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 25 (1985), S. 305-310 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Laminar mixing in a single screw extruder between two miscible liquids is considered. Studies are presented which examine the mixing performance in single screw extruders with mixing sections, variable geometry screws, and multi-viscosity mixtures. Model extruders, set up on engine lathes, were used to mix colored silicone rubber which eventually cured in the screw channel. The cured silicone was then removed and sliced to measure the mixing. Results show mixing as a function of both down channel location and total average strain. For the mixing section study, results support the theory of interfacial area reorientation as the key mechanism in mixing section performance. Increasing viscosity ratio for the multi-viscosity study showed a decrease in mixing rate.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760250510
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    Observations of NGC 7027 from 5.2 to 7.5 microns - The detection of Ni II and additional dust features (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: NGC 7027 was observed with a multichannel grating spectrometer from 5.2 to 7.5 microns at a spectral resolving power of 120-200. Two new dust emission features are resolved at 5.62 and 6.95 microns, and for the first time the Ni II fine-structure line at 6.64 microns is detected. It is shown that a single molecular dust constituent might account for six of the nine observed dust features between 2 and 14 microns. The strength of the Ni II line indicates either that Ni is not depleted in the neutral gas, or that the line is formed at high density.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 274; 666-670
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    The C2H, C2, and CN electronic absorption bands in the carbon star HD 19557 (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: Infrared spectrophotometry of the R-type carbon star HD 19557 is presented. Two unusual spectroscopic features are seen: a 3.1 micron band is lacking and a 2.8 micron band is present. Identifications are proposed for three previously unreported stellar absorption bands with electronic sequences of C2, CN, and C2H. The latter is proposed to be responsible for the 2.8 micron feature. The atmospheric structure of the star is studied with synthetic spectra, and an effective temperature between 2600 K and 3000 K is suggested. No SiC emission is seen at 11.3 microns, indicating that grain formation is not a viable process around the star. The lack of dust in R stars may suggest a salient difference between R and N types.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 270; July 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    The grains and gas in Comet Bowell 1980b (1983)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The importance of coordinating different types of observations of a comet is illustrated in terms of spectral data on Comet Bowell. Photometric data in 1980 indicated that OH emissions were occurring when the comet was still more than 4 AU from the sun. Further measurements were arranged with the IUE satellite, the photoelectric scanner at Cerro Tololo and the IR telescope on Mauna Kea. Several sizes of diaphragms were used in order to estimate variations with respect to aperture. Calculations were made to quantify the wavelengths observed as a function of the grains' cross-sections. The OH emission was confirmed by the spectrographic and photometric data. It is suggested that sufficient dark materials are present on the cometary surface to have enhanced the absorption of solar radiation to levels sufficient for heating and dissociating surface ice particles.
    Keywords: ASTROPHYSICS
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Angular distribution of interstellar Al-26 (1985)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The angular distribution and local concentration of interstellar Al-26 are calculated for five theoretical models of its origin, as a guide for future observations. The models considered relate Al-26 to current star formation (with surface CO density as its indicator), treat Al-26 as a secondary-nucleosynthesis product on seed nuclei with the same metallicity gradient as O, assume the Al-26 ejection rate is proportional to present light output, make Al-26 synthesis depend on total H I + H2 gas density, or assume that Al-26 is formed mainly in novae. The local decay and production rates for the five models are found to lie within a factor of 2 of surface density 0.0003/sq cm s, corresponding to a present (Al-26)/(Al-27) ratio of 5 x 10 to the -6th averaged over H I and H2 phases.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 294; 591-598
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    An ionization gradient across the front in M17 SW (1983)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Measurements of forbidden Ne II lines at 12.8 microns and forbidden S IV at 10.5 microns are presented along a line through and perpendicular to the ionization front in M17 SW. These observations give evidence for ionization stratification within the front, with the most highly ionized material lying toward the east, opposite to the peak molecular emission and far-IR flux. This result supports the picture of M17 SW as a region where a molecular cloud is heated externally. The ionization equilibrium within the ridge and the nebular energetics suggest that the M17 H II region is largely excited by one or more nearby early O stars. The properties of the recently discovered radio point source in M17 are discussed.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 275; 130-134
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    Electronic Resource
    Electronic Resource
    Discrete cell model of fixed-bed adsorbers with rectangular adsorption isotherms (1985)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 31 (1985), S. 1329-1337 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Adsorption of organics inot activated carbon particles within a fixed-bed adsorber is modeled using the concept of mixing cells. The adsorption isotherm of these organics is taken to be rectangular because of the commonly observed strong affinity of organics into activated carbons. The model equations are solved by a singular perturbation method, and this results in a graphical procedure similar to that of McCabe and Thiele used in distillation column design. Such a graphical procedure provides a quick means to determine the adsorbate profiles along the adsorber for a given time and also the breakthrough curve, which reflects the performance of the adsorber.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690310812
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Porosity effects on catalytic char oxidation. Part I: A catalyst deposition model (1985)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 31 (1985), S. 957-964 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Six char samples generated from two coals were impregnated by solutions with different concentrations of Na2CO3 and /or K2CO3. The catalyst solution penetration was studied, the catalyst uptake was measured, and the effects of impregnation on the char pore structure were determined experimentally. The results indicate that the impregnated catalysts reside only on particle exteriors without significant penetration. The overall rate of reaction is therfore the combination of catalytic reaction on particle exteriors and noncatalytic reaction on the pore surfaces inside the particle. A kinetic model is presented that takes these findings into account.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690310612
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Porosity effects on catalytic char oxidation. Part II: Experimental results (1985)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 31 (1985), S. 965-972 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Oxidation rates of Na2CO3- and K2CO3-impregnated char samples were measured in an isothermal kinetic control regime. The results were analyzed by a previously developed model to extract the intrinsic catalytic reactivities, freed from superimposed noncatalytic and structural effects. Although the overall catalyzed rates are only several times greater than their uncatalyzed counterparts, the intrinsic catalytic rates were found to be four orders of magnitude greater. The results further indicate that the function of the catalyst is to increase the number of active sites without affecting the activation energy. The overall reaction kinetics are demonstrated to contain the combined contributions of both catalytic and noncatalytic reactions, and in this context the effects of multiple catalysts as well as of the pore structure development during reaction can be understood and interpreted.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690310613
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...