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
    Thermogravimetric and microcalorimetric studies of ZSM-5 acidity (1993)
    Springer
    Catalysis letters 18 (1993), S. 183-192 
    Details
    ISSN: 1572-879X
    Keywords: Acidity ; zeolites ; microcalorimetry ; thermogravimetry ; pyridine adsorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The combination of thermogravimetry, microcalorimetry and infrared spectroscopy studies of pyridine adsorption has been used to characterize the acidity of a ZSM-5 catalyst. The majority of the acid sites are Brønsted acid centers associated with framework Al species, with heats of pyridine adsorption equal to 140 kJ/mol. Non-framework Al species in the zeolite sample of this study eliminate an approximately equal number of Brønsted acid sites. These nonframework Al species also produce strong Lewis acid sites with pyridine adsorption heats greater than 140 kJ/mol, as well as weak adsorption sites (e.g., weak Bransted acid sites or hydrogen bonding sites) with heats equal to 90–140 kJ/mol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00769437
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Microcalorimetric studies of zeolite acidity (1992)
    Springer
    Catalysis letters 12 (1992), S. 201-211 
    Details
    ISSN: 1572-879X
    Keywords: Acidity ; gravimetry ; heat of adsorption ; H-Mordenite ; H-Y ; H-ZSM-5 ; microcalorimetry ; pyridine ; zeolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The acidity characteristics of H-ZSM-5, H-Mordenite and H-Y zeolite have been studied by microcalorimetric and gravimetric measurements of pyridine adsorption. H-ZSM-5 and H-Mordenite have Brønsted acid sites of primarily homogenous strength, with H-Mordenite having the stronger sites, whereas H-Y zeolite had Brønsted sites of varying strength. The effects of Na exchange level in H-Y zeolite and high temperature calcination for H-Mordenite have also been examined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00767202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    Analysis of stratocumulus cloud fields using LANDSAT imagery: Size distributions and spatial separations (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-01-25
    Description: Stratocumulus cloud fields in the FIRE IFO region are analyzed using LANDSAT Thematic Mapper imagery. Structural properties such as cloud cell size distribution, cell horizontal aspect ratio, fractional coverage and fractal dimension are determined. It is found that stratocumulus cloud number densities are represented by a power law. Cell horizontal aspect ratio has a tendency to increase at large cell sizes, and cells are bi-fractal in nature. Using LANDSAT Multispectral Scanner imagery for twelve selected stratocumulus scenes acquired during previous years, similar structural characteristics are obtained. Cloud field spatial organization also is analyzed. Nearest-neighbor spacings are fit with a number of functions, with Weibull and Gamma distributions providing the best fits. Poisson tests show that the spatial separations are not random. Second order statistics are used to examine clustering.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: NASA, Langley Research Center, FIRE Science Results 1988; p 277
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Cloud field classification based upon high spatial resolution textural features. I - Gray level co-occurrence matrix approach (1988)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: Stratocumulus, cumulus, and cirrus clouds were identified on the basis of cloud textural features which were derived from a single high-resolution Landsat MSS NIR channel using a stepwise linear discriminant analysis. It is shown that, using this method, it is possible to distinguish high cirrus clouds from low clouds with high accuracy on the basis of spatial brightness patterns. The largest probability of misclassification is associated with confusion between the stratocumulus breakup regions and the fair-weather cumulus.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Geophysical Research (ISSN 0148-0227); 93; 12663-12
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Classification of cloud fields based on textural characteristics (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The present study reexamines the applicability of texture-based features for automatic cloud classification using very high spatial resolution (57 m) Landsat multispectral scanner digital data. It is concluded that cloud classification can be accomplished using only a single visible channel.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Digital Image Processing and Visual Communications Technologies in Meteorology; Oct 27, 1987 - Oct 28, 1987; Cambridge, MA; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Cloud field classification based upon high spatial resolution textural features. II - Simplified vector approaches (1989)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: This paper compares the results of cloud-field classification derived from two simplified vector approaches, the Sum and Difference Histogram (SADH) and the Gray Level Difference Vector (GLDV), with the results produced by the Gray Level Cooccurrence Matrix (GLCM) approach described by Welch et al. (1988). It is shown that the SADH method produces accuracies equivalent to those obtained using the GLCM method, while the GLDV method fails to resolve error clusters. Compared to the GLCM method, the SADH method leads to a 31 percent saving in run time and a 50 percent saving in storage requirements, while the GLVD approach leads to a 40 percent saving in run time and an 87 percent saving in storage requirements.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Geophysical Research (ISSN 0148-0227); 94; 14749-14
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Cumulus cloud field morphology and spatial patterns derived from high spatial resolution Landsat imagery (1990)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: Using high-spatial-resolution Landsat MSS imagery, the cumulus cloud morphology, cloud nearest-neighbor distributions, and cloud clumping scales were investigated. It is shown that the cloud-size distribution can be represented by a mixture of two power laws; clouds of diameters less than 1 km have power-law slope range of 1.4-2.3, while larger clouds have slopes from 2.1 to 4.75. The break in power-law slope occurs at the cloud size that makes the largest contribution to cloud cover. Results suggest that larger clouds grow at the expense of smaller clouds. It was also found that the cloud inhomogeneities have significant impact on radiative fluxes.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Applied Meteorology (ISSN 0894-8763); 29; 1245-126
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...