Library

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
    Kinetic aspects of the solid hydrogenation– disproportionation–desorption–recombination process in Nd13.67Co15.74Al0.77Ga0.27Zr0.03Fe62.2B7.33 alloys (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 3786-3791 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The hydrogenation–disproportionation–desorption–recombination process is known as a novel method for producing permanent magnets. The hydrogen driven reactions involved in this process are carefully studied here using Mössbauer effect, x-ray diffraction and scanning microscopy, in the Nd13.67Co15.74Al0.77Ga0.27Zr0.03Fe62.2B7.33 alloy. The temperature dependence of the hydrogenation disproportionation in the 119 kPa isochore line was obtained. Hydrogen absorption seems to occur in two steps: absorption from Nd at the grain boundaries followed by absorption from the Nd2Fe14B type phase. In order to determine the recombination kinetics, a typical mass of the alloy was submitted to disproportionation reaction at 800 °C under a hydrogen pressure of 119 kPa, followed by recombination, which was achieved by vacuum desorption at 800 °C and subsequent quenching to room temperature after various time intervals. It was found that the relative fraction of the Nd2(Fe,Co)14B phase, as obtained from the Mössbauer effect, increases as f=1−exp(−ktn) with n=0.99±0.05. From this growing law it is inferred that recombination occurs without long range diffusion and starts at the grain boundaries with zero nucleation rate. An activation energy of 0.64±0.13 eV/atom was obtained for this process. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.368589
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The trophic role of lutjanid fish and impacts of their fisheries in two ecosystems in the Gulf of Mexico (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 53 (1998), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The trophic role of snappers was evaluated on the continental shelves of the south-western Gulf of Mexico and the Yucatan in the south-eastern Gulf of Mexico. Mass-balanced, steady-state trophic models of the two ecosystems were constructed with Ecopath and perturbations were simulated in the ecosystems with Ecosim by increasing fishing mortality. Impacts were measured by changes in biomass of snappers and other groups, and in some indices of stability: persistence, recovery time and resilience. The snapper populations differed between ecosystems. The western Gulf of Mexico system appeared more complex and more stable than the Continental Shelf of Yucatan. Although overall stability indices between ecosystem suggested a similar structure and function, there were clear differences at a group level. Correlation of stability attributes between groups suggested differences in the role of snappers between the ecosystems suggesting that each stock should be managed individually.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1998.tb01024.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Energy flow and network analysis of Terminos Lagoon, SW Gulf of Mexico (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 53 (1998), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The food web in Terminos Lagoon, south-western Gulf of Mexico was dominated by the detrital pathway, with benthic invertebrates playing a significant role in transferring energy from detritus to higher trophic levels. The fish yield per unit of net primary production was only 0.04%. Fractional trophic levels ranged from 1.0 to 3.31, with fish occupying the highest trophic levels. Using network analysis, the system network was mapped into a linear food chain and five discrete trophic levels were found with a mean trophic transfer efficiency of 7%. Analysis of mixed trophic impacts showed that fish had very little impact on the other compartments, due to their relatively low biomass and consumption, with exception of the Engraulidae. Detritus and lower trophic levels had significant positive impacts on other groups in the system, suggesting ‘bottom-up’ control of the food web. A high detritivory: herbivory ratio (4.6: 1) indicated that most of the primary production was recycled through the detritus-based food web. A Finn cycling index of 7% and average path length of 10 were obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1998.tb01026.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The GTC: An Advanced 10m Telescope for the ORM (1998)
    Springer
    Astrophysics and space science 263 (1998), S. 355-360 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Gran Telescopio CANARIAS (GTC) is a high performance 10-m class telescope whose construction has been promoted by the IAC (Instituto de Astrofísica de Canarias). It will be installed at the Roque de los Muchachos Observatory (ORM), in the island of La Palma. First light is planned for end-2002. The key science drivers for the project are image quality, operational efficiency and reliability, as emphasized in the Conceptual Design Document which was finished in mid-97. The Preliminary Design is now proceeding on all aspects of the project. The GTC Project is presently funded at the 70% level by Spain. The scientific drives behind the GTC project are described here, as well as the current technical, managerial, and operational baseline.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1002116107527
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Room-temperature epitaxial growth of CeO2(001) films on YSZ buffered Si(001) substrates (1998)
    Springer
    Applied physics 67 (1998), S. 455-457 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 68.55; 81.15 Z
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: 2 (001) epitaxial thin films deposited on Si(001) with yttria-stabilized zirconia buffers have been obtained for the first time at room temperature by pulsed-laser deposition. The influence of oxygen pressure on the crystal quality of CeO2 was studied for the films deposited at 100 °C. The rocking curve full width at half maximum of the CeO2(002) peak for films deposited at room temperature and 100 °C was between 1° and 2°, for oxygen pressures below 3×10-2 mbar. The best crystal quality was obtained at around 3×10-3 mbar. Epitaxial growth at room temperature was confirmed by cross-sectional transmission electron microscopy. Scanning electron microscopy and atomic force microscopy revealed very smooth surfaces for oxygen pressure below 3×10-2 mbar, with rms roughness values around 0.3 nm over 5 μm×5 μm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050803
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Dynamics of the hydrodynamical growth of columns on silicon exposed to ArF excimer-laser irradiation (1998)
    Springer
    Applied physics 66 (1998), S. 83-86 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 81.40 Z; 81.60 Z; 68.70
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050641
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Some remarks stemming from Ulam's problem about nearly additive mappings (1998)
    Springer
    Aequationes mathematicae 56 (1998), S. 233-242 
    Details
    ISSN: 1420-8903
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract. We consider the following problems: Let $(S, +)$ be a (not necessarily commutative) semigroup and let $\rho : S \to {\Bbb R}$ be a given “control” functional (which is not assumed to be sub-additive). Assume that $F : S \to {\Bbb R}$ is a “nearly additive” mapping in either of the following ways: (1) $|F(x + y) - F(x) - F(y)| \le \rho(x) + \rho(y) - \rho(x + y)$ holds for all $x, y \in S$ . (2) $\Bigl|\sum^n_{i = 1} F(x_i) - \sum^m_{j = 1} F(y_j)\Bigr| \le \sum^n_{i = 1} \rho(x_i) + \sum^m_{j = 1} \rho(y_j) $ holds for all n and m whenever $x_i$ and $y_j$ are elements of S such that $\sum^n_{i = 1} x_i = \sum^m_{j = 1} y_j$ . Must F be “near” to an additive mapping $A : S \to {\Bbb R}$ in the sense that (3) $|F(x) - A(x)| \le K\rho (x)$ for some K and all $x \in S$ ? We prove Theorem. Let $(S, +)$ be a semigroup and let K be a fixed number. The following statements are equivalent: (a) For every ρ and every F satisfying (1) there is an additive A fulfilling (3). (b) For every ρ and every F satisfying (2) there is an additive A fulfilling (3). Moreover, for K = 1 both (a) and (b) are equivalent to (c) For every $\alpha, \beta : S \to {\Bbb R}$ such that α is superadditive (i.e., $\alpha(x + y) \ge \alpha(x) + \alpha(y))$ , β is subadditive and $\alpha \le \beta$ , there exists an additive A separating α from β (that is, satisfying $a(x) \le A(x) \le \beta (x))$ . Combining this theorem with previous results of Ger and Gajda and Kominek we obtain that every weakly commutative group satisfies (b) for K = 1 and every amenable group satisfies (b) for K = 2, which gives a partial answer to a problem suggested by Forti, improving results by Šemrl and Castillo and the present author. We close the paper with some remarks about vector-valued mappings and the connections between “nearly additive” mappings and the theory of extensions of Banach spaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000100050059
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Ala397Asp mutation of myosin VIIA gene segregating in a Spanish family with type-Ib Usher syndrome (1998)
    Springer
    Human genetics 〈Berlin〉 102 (1998), S. 691-694 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In the current study, 12 Spanish families affected by type-I Usher syndrome, that was previously linked to chromosome 11q, were screened for the presence of mutations in the N-terminal coding portion of the motor domain of the myosin VIIA gene by single-strand conformation polymorphism analysis of the first 14 exons. A mutation (Ala397Asp) segregating with the disease was identified, and several polymorphisms were also detected. It is presumed that the other USH1B mutations in these families could be located in the unscreened regions of the gene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004390050763
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Bilateral hydatid cyst of pulmonary arteries: MR and CT findings (1998)
    Springer
    European radiology 8 (1998), S. 1170-1172 
    Details
    ISSN: 1432-1084
    Keywords: Key words: Hydatid cyst ; Pulmonary arteries ; MR ; CT
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The location of hydatid cysts inside pulmonary arteries has been reported only on rare occasions in the literature and is caused, in the majority of cases, by embolization due to the rupture of hydatid cysts located in the heart; more rarely, hematogenous dissemination from a hepatic focus is the cause. We report a case of a 44-year-old patient with hydatid cysts located in both the right and left pulmonary arteries, whose first clinical reference was hemoptysis. The patient had undergone surgery because of a hepatic hydatid cyst 5 months previously. The importance of this case lies in the infrequent bilateral location in both pulmonary arteries and in the absence of intracardiac hydatid cysts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003300050528
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Spontaneous non-O1Vibrio cholerae peritonitis after raw oyster ingestion in a patient with cirrhosis (1998)
    Springer
    European journal of clinical microbiology & infectious diseases 17 (1998), S. 362-363 
    Details
    ISSN: 1435-4373
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01709463
    Library Location Call Number Volume/Issue/Year 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...