ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • Chemical Engineering  (60)
  • METEOROLOGY AND CLIMATOLOGY  (55)
  • ASTRONOMY
  • ENERGY PRODUCTION AND CONVERSION
  • 1990-1994  (186)
  • 1980-1984
  • 1991  (186)
Collection
Publisher
Years
  • 1990-1994  (186)
  • 1980-1984
Year
  • 1
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2011-08-19
    Description: Measurements of time delay and Doppler frequency are reported for asteroid-radar echoes obtained at Arecibo and Goldstone during 1980-1990. Radar astrometry is presented for 23 near-earth asteroids and three mainbelt asteroids. These measurements, which are orthogonal to optical, angular-position measurements, and typically have a fractional precision between 10 to the -5th and 10 to the -8th, permit significant improvement in estimates of orbits and hence in the accuracy of prediction ephemerides. Estimates are also reported of radar cross-section and circular polarization ratio for all asteroids observed astrometrically during 1980-1990.
    Keywords: ASTRONOMY
    Type: Astronomical Journal (ISSN 0004-6256); 102; 1490-150
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2013-08-31
    Description: The radiation hardness of a two-junction monolithic Ga sub 0.5 In sub 0.5 P/GaAs cell with tunnel junction interconnect was investigated. Related single junction cells were also studied to identify the origins of the radiation losses. The optimal design of the cell is discussed. The air mass efficiency of an optimized tandem cell after irradiation with 10(exp 15) cm (-2) 1 MeV electrons is estimated to be 20 percent using currently available technology.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA. Lewis Research Center, Space Photovoltaic Research and Technology Conference; 7 p
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2019-06-28
    Description: Large area GaAs/Ge cells offer substantial promise for increasing the power output from existing silicon solar array designs and for providing an enabled technology for missions hitherto impossible using silicon. Single junction GaAs/Ge cells offer substantial advantages in both size, weight, and cost compared to GaAs cells but the efficiency is limited to approximately 19.2 to 20 percent AMO. The thermal absorptance of GaAs/Ge cells is also worse than GaAs/GaAs cells (0.88 vs 0.81 typ.) due to the absorption in the Ge substrate. On the other hand dual junction GaAs/Ge cells offer efficiencies up to ultimately 24 percent AMO in sizes up to 8 x 8 cm but there are still technological issues remaining to achieve current matching in the GaAs and Ge cells. This can be achieved through tuned antireflection (AR) coatings, improved quality of the GaAs growth, improved quality Ge wafers and the use of a Back Surface Field (BSF)/Back Surface Reflector (BSR) in the Ge cell. Although the temperature coefficients of efficiency and voltage are higher for dual junction GaAs/Ge cells, it has been shown elsewhere that for typical 28 C cell efficiencies of 22 percent (dual junction) vs 18.5 percent (single junction) there is a positive power tradeoff up to temperatures as high as 120 C. Due to the potential ease of fabrication of GaAs/Ge dual junction cells there is likely to be only a small cost differential compared to single junction cells.
    Keywords: ENERGY PRODUCTION AND CONVERSION
    Type: NASA, Lewis Research Center, Space Photovoltaic Research and Technology, 1989; p 29-41
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2019-07-12
    Description: Snow feedback is expected to amplify global warming caused by increasing concentrations of atmospheric greenhouse gases. The conventional explanation is that a warmer earth will have less snow cover, resulting in a darker planet that absorbs more solar radiation. An intercomparison of 17 general circulation models, for which perturbations of sea surface temperature were used as a surrogate climate change, suggests that this explanation is overly simplistic. The results instead indicate that additional amplification or moderation may be caused both by cloud interactions and longwave radiation. One measure of this net effect of snow feedback was found to differ markedly among the 17 climate models, ranging from weak negative feedback in some models to strong positive feedback in others.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Science (ISSN 0036-8075); 253; 888-892
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 31 (1991), S. 56-60 
    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: Resin transfer molding (RTM) of advanced fiber architecture materials promises to be a cost effective process for obtaining composite parts with exceptional strength. However there are a larger number of material processing parameters that must be observed, known, and/or controlled during the resin transfer molding process. These include the viscosity both during impregnation and cure. In-situ sensors which can observe these processing properties within the RTM tool during the fabrication process are essential. This paper will discuss recent work on the use of frequency dependent electromagnetic sensing (FDMS) techniques to monitor these properties in the RTM tool. Our objective is to use these sensing techniques to address problems of RTM scaleup for large complex parts and to develop a closed loop, intelligent, sensor controlled RTM fabrication process.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Microkinetic simulations have been carried out to describe the partial oxidation of methane over silica-supported molybdena and vanadia. The objective of this study was to formulate a physically reasonable reaction network to capture the basic aspects of the surface catalytic chemistry and to use this network to link methane oxidation kinetics with the kinetics observed for the oxidation of subsequent gaseous products, i.e., methanol, formaldehyde, and carbon monoxide. The most abundant reactive intermediates on the catalyst surface are suggested to be oxygen and hydroxyl groups. This reaction network successfully predicts the catalytic activities, selectivities, activation energies, and reaction orders observed over silica-supported molybdena and vanadia; and the microkinetic model also semiquantitatively explains the kinetic trends for related catalyst systems and is consistent with surface bonding energetics reported in the literature over various oxide catalysts. The microkinetic reaction network properly reduces to the more simple macrokinetic model reported previously for methane partial oxidation.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1-38 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: As steady-state and dynamic simulators with optimal controllers have evolved, tools for nonlinear analysis have been developed by reactor and thermophysical property specialists. Designers lag behind in developing and utilizing these tools, as many design strategies assume idealized behavior even though processes contain an increasing number of nonlinear elements. This article examines the sources of the nonlinear elements, often associated with physical and chemical interactions, in designs and their control systems. Promising methods for nonlinear analysis are reviewed.In each design activity, involving simulation, economic optimization, projections of controllability and operability, emphasis is on the sources of nonlinearities and solution methods. These are examined for the equality constraints and nonlinear programs in phase and chemical equilibria, in reactors and separators, and in the simulation and optimization of flowsheets. Also examined are the impact of non-linear predictive control in screening designs and methods to insure operability, in the face of uncertainties.
    Additional Material: 27 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 31 (1991), S. 684-687 
    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: Films of polyacetylene synthesized according to Akagi method present a high degree of crystallinity. A 6-7 times stretching of these films results in the orientation of the polymer fibers: The mosaic was ± 5 degrees. Such highly oriented polyacetylene (HOPA) films were chemically doped by heavy alkali metals in the vapor state and electrochemically with GaCl4- anion in nitromethane medium. The evolution of the structures and the variation of the electrical conductivity upon doping were examined in both cases.Doping with alkali metal leads to the appearance of different intercalated phases: The commensurability of these phases is discussed as a function of the nature and the concentration of the intercalated alkaline ion. The electrical maximum room temperature conductivity, which depends on the nature of the alkali metal, is maximum for K-doped materials. In the case of GaCl4- doping, the unique intercalated phase observed is poorly organized except in the chain direction where a GaCl4- ion is found every 4.5 (CH) units. The room temperature electrical conductivity measured along the chain axis is equal to 15 000 S/cm, one order of magnitude higher than the value observed in Shirakawa unoriented polyacetylene.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 31 (1991), S. 1670-1673 
    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: The rheological characteristics of a number of polymer blends, including amorphous and semi-crystalline plastic matrices, during melting or softening, are analyzed with a batch mixer. The physical changes accompanying the phase transitions taking place as the slat-and-pepper blends are heated and mixed in the region of their component melt transition temperatures are monitored visually through a transparent window with video recordings. The torque of mixing and the mixture temperature are also recorded continuously. The strong effects of additives such as filler or lower melting resin as well as rotor speed, degree of fill, and ram pressure were observed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...