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
    The fractal behaviour of triangular refined/derefined meshes (1996)
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 12 (1996), S. 295-302 
    Details
    ISSN: 1069-8299
    Keywords: mesh generation ; adaptivity ; iterated fractal systems ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In the paper the author presents a novel point of view for the refinement and derefinement algorithms of triangular nested meshes using fractal concepts and iterated function systems (IFS). The fractal behaviour can be understood in the sense that these meshes feature a remarkable amplifying invariance under changes of magnification. Here we compare the meshes obtained by the combination of these algorithms with those presented by Bova and Carey (1992). Although both of the meshes are very similar, the current algorithms automatically build and manage sequences of nested irregular discretizations of the domain. The author illustrates here how the application of IFS families is equivalent to the use of an adaptive strategy that combines the refinement procedure with the derefinement one.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 2
    Electronic Resource
    Electronic Resource
    N-Arylation of Pyrrolidino[3′,4′:1,2][60]fullerene: Synthesis under Solvent-Free Conditions and Electrochemistry of New C60-Acceptor Dyads (1999)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 3433-3436 
    Details
    ISSN: 1434-193X
    Keywords: Cyclic voltammetry ; Fullerenes ; Phase-transfer catalysis ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several pyrrolidinofullerenes were N-arylated by phase-transfer catalysis in the absence of solvent. The electrochemical behaviour of the novel C60-acceptor dyads was studied by cyclic voltammetry which showed that the nitro groups on the N-phenyl ring have a strong influence on the reduction potential values. Theoretical calculations at the semiempirical PM3 level fully support the experimental redox potential values.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    An X-Ray diffraction study of poly-L-ornithine hydrobromide (1973)
    New York : Wiley-Blackwell
    Biopolymers 12 (1973), S. 1997-2006 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An X-ray study has been made of the synthetic polypeptide poly-L-ornithine hydrobromide to investigate whether, like the chemically related polypeptides poly-L-lysine and poly-L-arginine hydrochlorides, it can undergo conformational changes merely from variations in its degree of hydration. X-ray powder and fiber photographs of specimens with from half up to about three molecules of water per ornithine residue show features that suggest a “cross-β-pleated-sheet” structure. Each pleated sheet is formed from parallel chains and the sheets are piled up along the b axis. The spacings, which do not vary appreciably with hydration, can be satisfactorily indexed in terms of an orthogonal unit cell with a = 4.60 Å, b = 30.2 Å, and c = 6.64 Å. These dimensions are shown by models to be compatible with the proposed structure. Removal of the last half molecule of water results in a very diffuse pattern but on rehydration the sharp pattern reappears. Specimens containing four to nine molecules of water per residue show a quite different pattern. Reflections other than equatorial are absent in oriented diagrams except for a 5.4 Å diffuse streak across the meridian which is suggestive of an α-helical structure. Increasing the relative humidity from 86% to about 100% causes the a axis of the hexagonal unit cell to increase from 14.7 Å to 15.3 Å. On drying, the β structure reappears once again. These conformational changes are very similar to those observed in poly-L-lysine hydrochloride except that the latter shows a more stable α-helical form. This difference may be explained in terms of stabilizing hydrophobic interactions between side chains, since ornithine has a shorter side chain than lysine.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1973.360120907
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Synthesis, Characterization and Dynamic Behavior of (π-Allyl)palladium Complexes with Polydentate Nitrogen Ligands, Evidence of a Dissociative Mechanism (1996)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 129 (1996), S. 589-594 
    Details
    ISSN: 0009-2940
    Keywords: Fluxionality ; Heterocyclic ligands ; Palladium complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New examples of the fluxional behavior of (η3-allyl)palla-dium complexes are described. Variable-temperature experiments and line-shape analysis of two (η3-allyl)palladium complexes containing 2-(1H-pyrazol-1-yl)azine ligands were performed in order to determine the activation free energies, enthalpies and entropies of the process. A dissociative mechanism pointing to a selective Pd-N cleavage is proposed on the basis of these results and NOE experiments above and below the coalescence temperature.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19961290519
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    NMR studies in the heterocyclic series. XXXIIFor Part XXXI, see M. Begtrup, J. Elguero, R. Faure, P. Camps, C. Estopá, D. Ilavský, A. Fruchier, C. Marzin and J. de Mendoza, Magn. Reson. Chem. 26, 134 (1988).. Carbon-13 NMR study of N-arylpyrazoles and N-arylpyrazolium salts (1989)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 27 (1989), S. 603-606 
    Details
    ISSN: 0749-1581
    Keywords: 13C NMR ; Chemical shifts ; J(CH) and J(FC) ; N-Arylpyrazoles ; N-Arylpyrazolium salts ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260270615
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    facet.materialart.
    Unknown
    Sensors, Vol. 15, Pages 29547-29568: Automated Negotiation for Resource Assignment in Wireless Surveillance Sensor Networks (2015)
    MDPI Publishing
    In: Sensors
    Details
    Publication Date: 2015-11-25
    Description: Due to the low cost of CMOS IP-based cameras, wireless surveillance sensor networks have emerged as a new application of sensor networks able to monitor public or private areas or even country borders. Since these networks are bandwidth intensive and the radioelectric spectrum is limited, especially in unlicensed bands, it is mandatory to assign frequency channels in a smart manner. In this work, we propose the application of automated negotiation techniques for frequency assignment. Results show that these techniques are very suitable for the problem, being able to obtain the best solutions among the techniques with which we have compared them.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Water, Vol. 10, Pages 817: Reuse and Recycling of Livestock and Municipal Wastewater in Chilean Agriculture: A Preliminary Assessment (2018)
    MDPI Publishing
    In: Water
    Details
    Publication Date: 2018-06-21
    Description: Water, Vol. 10, Pages 817: Reuse and Recycling of Livestock and Municipal Wastewater in Chilean Agriculture: A Preliminary Assessment Water doi: 10.3390/w10060817 Authors: Cristina-Alejandra Villamar Ismael Vera-Puerto Diego Rivera Felipe De la Hoz Chile is an agricultural power, but also one of the most vulnerable countries to climate change and water shortage. About 50% of the irrigated agriculture land in Chile is in the central zone, thanks to its agricultural-climatic characteristics that provide an adequate water supply (100–4000 m3/s). However, the vulnerability scenario in this zone is high due to the seasonal availability of water resources. Therefore, opportunities to use non-conventional alternative sources (e.g., wastewater) become an appealing and feasible option due to the high population and animal density (>76%) in this part of the country. Moreover, the physicochemical characteristics of the municipal and livestock wastewater suggest that there are potential opportunities to recycle nutrients for agricultural production. In Chile, wastewater reuse opportunities are noted by the wide coverage of wastewater treatment programs, with municipal and intensified livestock production taking up most of the percentage (>99%). Nevertheless, more than 70% of wastewater treatment systems reach biological secondary treatment, which suggests reuse possibilities only for non-food crops. Therefore, this paper is focused on a preliminary analysis of the potential of reusing and recycling municipal and livestock wastewater for Chilean agriculture. There is some reuse work occurring in Chile, specifically in the use of municipal and livestock wastewater for cereal crops (animal feed), forests, and grasslands. However, aspects related to the long-term effects of these practices have not yet been evaluated. Therefore, municipal and livestock wastewater in Chile could be re-valued in agriculture, but the current quality and condition of treated wastewater do not ensure its safe use in food crops. In addition, state policies are needed to provide sustainability (circular and ethic economy) to water reusing/recycling in agriculture.
    Electronic ISSN: 2073-4441
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Sensors, Vol. 18, Pages 2255: Real-Time Early Warning System Design for Pluvial Flash Floods—A Review (2018)
    MDPI Publishing
    In: Sensors
    Details
    Publication Date: 2018-07-13
    Description: Sensors, Vol. 18, Pages 2255: Real-Time Early Warning System Design for Pluvial Flash Floods—A Review Sensors doi: 10.3390/s18072255 Authors: Melisa Acosta-Coll Francisco Ballester-Merelo Marcos Martinez-Peiró Emiro De la Hoz-Franco Pluvial flash floods in urban areas are becoming increasingly frequent due to climate change and human actions, negatively impacting the life, work, production and infrastructure of a population. Pluvial flooding occurs when intense rainfall overflows the limits of urban drainage and water accumulation causes hazardous flash floods. Although flash floods are hard to predict given their rapid formation, Early Warning Systems (EWS) are used to minimize casualties. We performed a systematic review to define the basic structure of an EWS for rain flash floods. The structure of the review is as follows: first, Section 2 describes the most important factors that affect the intensity of pluvial flash floods during rainfall events. Section 3 defines the key elements and actors involved in an effective EWS. Section 4 reviews different EWS architectures for pluvial flash floods implemented worldwide. It was identified that the reviewed projects did not follow guidelines to design early warning systems, neglecting important aspects that must be taken into account in their implementation. Therefore, this manuscript proposes a basic structure for an effective EWS for pluvial flash floods that guarantees the forecasting process and alerts dissemination during rainfall events.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Symmetry, Vol. 10, Pages 65: Spectrum Graph Coloring and Applications to Wi-Fi Channel Assignment (2018)
    MDPI Publishing
    In: Symmetry
    Details
    Publication Date: 2018-03-14
    Description: Symmetry, Vol. 10, Pages 65: Spectrum Graph Coloring and Applications to Wi-Fi Channel Assignment Symmetry doi: 10.3390/sym10030065 Authors: David Orden Jose Gimenez-Guzman Ivan Marsa-Maestre Enrique de la Hoz We introduce and explore a family of vertex-coloring problems, which, surprisingly enough, have not been considered before despite stemming from the problem of Wi-Fi channel assignment. Given a spectrum of colors, endowed with a matrix of interferences between each pair of colors, the Threshold Spectrum Coloring problem fixes the number of colors available and aims to minimize the interference threshold, i.e., the maximum of the interferences at the vertices. Conversely, the Chromatic Spectrum Coloring problem fixes a threshold and aims to minimize the number of colors for which respecting that threshold is possible. As the main theoretical results, we prove tight upper bounds for the solutions to each problem. Since both problems turn out to be NP-hard, we complete the scene with experimental results. We propose a DSATUR-based heuristic and study its performance to minimize the maximum vertex interference in Wi-Fi channel assignment, both for randomly-generated graphs and for a real-world scenario. Further, for all these graphs, we experimentally check the goodness of the theoretical bounds.
    Electronic ISSN: 2073-8994
    Topics: Mathematics , Physics
    Published by MDPI Publishing
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Sensors, Vol. 18, Pages 917: Access Control Mechanism for IoT Environments Based on Modelling Communication Procedures as Resources (2018)
    MDPI Publishing
    In: Sensors
    Details
    Publication Date: 2018-03-21
    Description: Sensors, Vol. 18, Pages 917: Access Control Mechanism for IoT Environments Based on Modelling Communication Procedures as Resources Sensors doi: 10.3390/s18030917 Authors: Luis Cruz-Piris Diego Rivera Ivan Marsa-Maestre Enrique de la Hoz Juan Velasco Internet growth has generated new types of services where the use of sensors and actuators is especially remarkable. These services compose what is known as the Internet of Things (IoT). One of the biggest current challenges is obtaining a safe and easy access control scheme for the data managed in these services. We propose integrating IoT devices in an access control system designed for Web-based services by modelling certain IoT communication elements as resources. This would allow us to obtain a unified access control scheme between heterogeneous devices (IoT devices, Internet-based services, etc.). To achieve this, we have analysed the most relevant communication protocols for these kinds of environments and then we have proposed a methodology which allows the modelling of communication actions as resources. Then, we can protect these resources using access control mechanisms. The validation of our proposal has been carried out by selecting a communication protocol based on message exchange, specifically Message Queuing Telemetry Transport (MQTT). As an access control scheme, we have selected User-Managed Access (UMA), an existing Open Authorization (OAuth) 2.0 profile originally developed for the protection of Internet services. We have performed tests focused on validating the proposed solution in terms of the correctness of the access control system. Finally, we have evaluated the energy consumption overhead when using our proposal.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
    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...