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51.
Tim Schröder Lars-Peter Lauven Jutta Geldermann 《European Journal of Operational Research》2018,264(3):1005-1019
Biorefineries can provide a product portfolio from renewable biomass similar to that of crude oil refineries. To operate biorefineries of any kind, however, the availability of biomass inputs is crucial and must be considered during planning. Here, we develop a planning approach that uses Geographic Information Systems (GIS) to account for spatially scattered biomass when optimizing a biorefinery’s location, capacity, and configuration. To deal with the challenges of a non-smooth objective function arising from the geographic data, higher dimensionality, and strict constraints, the planning problem is repeatedly decomposed by nesting an exact nonlinear program (NLP) inside an evolutionary strategy (ES) heuristic, which handles the spatial data from the GIS. We demonstrate the functionality of the algorithm and show how including spatial data improves the planning process by optimizing a synthesis gas biorefinery using this new planning approach. 相似文献
52.
We construct globally regular gravitating solutions, which possess only discrete symmetries. These solutions of Yang–Mills-dilaton theory may be viewed as exact (numerical) solutions of scalar gravity, by considering the dilaton as a kind of scalar graviton, or as approximate solutions of Einstein–Yang–Mills theory. We focus on platonic solutions with cubic symmetry, related to a rational map of degree N=4. We present the first two solutions of the cubic N=4 sequence, and expect this sequence to converge to an extremal Reissner–Nordström solution with magnetic charge P=4. 相似文献
53.
Valeria Kagramanova Jutta Kunz Claus Lämmerzahl 《General Relativity and Gravitation》2008,40(6):1249-1278
Orbits of test particles and light rays are an important tool to study the properties of space-time metrics. Here we systematically
study the properties of the gravitational field of a globally regular magnetic monopole in terms of the geodesics of test
particles and light. The gravitational field depends on two dimensionless parameters, defined as ratios of the characteristic
mass scales present. For critical values of these parameters the resulting metric coefficients develop a singular behavior,
which has profound influence on the properties of the resulting space-time and which is clearly reflected in the orbits of
the test particles and light rays. 相似文献
54.
Burkhard Kleihaus Jutta Kunz Francisco Navarro-Lérida Ulrike Neemann 《General Relativity and Gravitation》2008,40(6):1279-1310
We consider globally regular and black hole solutions in SU(2) Einstein–Yang–Mills–Higgs theory, coupled to a dilaton field.
The basic solutions represent magnetic monopoles, monopole–antimonopole systems or black holes with monopole or dipole hair.
When the globally regular solutions carry additionally electric charge, an angular momentum density results, except in the
simplest spherically symmetric case. We evaluate the global charges of the solutions and their effective action, and analyze
their dependence on the gravitational coupling strength. We show, that in the presence of a dilaton field, the black hole
solutions satisfy a generalized Smarr type mass formula.
B. Kleihaus gratefully acknowledges support by the German Aerospace Center.
F. Navarro-Lérida gratefully acknowledges support by the Ministerio de Educación y Ciencia under grant EX2005-0078. 相似文献
55.
56.
Daniel Josef Bell Monika Wiese Ariel Augusto Schönberger Matthias Wessling 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16181-16187
Metal–organic frameworks (MOFs) are suitable enzyme immobilization matrices. Reported here is the in situ biomineralization of glucose oxidase (GOD) into MOF crystals (ZIF-8) by interfacial crystallization. This method is effective for the selective coating of porous polyethersulfone microfiltration hollow fibers on the shell side in a straightforward one-step process. MOF layers with a thickness of 8 μm were synthesized, and fluorescence microscopy and a colorimetric protein assay revealed the successful inclusion of GOD into the ZIF-8 layer with an enzyme concentration of 29±3 μg cm−2. Enzymatic activity tests revealed that 50 % of the enzyme activity is preserved. Continuous enzymatic reactions, by the permeation of β-d -glucose through the GOD@ZIF-8 membranes, showed a 50 % increased activity compared to batch experiments, emphasizing the importance of the convective transport of educts and products to and from the enzymatic active centers. 相似文献
57.
Josef Schormüller und Jutta Walter 《Fresenius' Journal of Analytical Chemistry》1952,134(5):337-352
Zusammenfassung Die Threonin- bzw. die Threonin und Serinbestimmung auf chemischem Wege werden hinsichtlich der beiden wichtigsten Verfahren, nämlich der Oxydation mit Bleitetraacetat und mit Perjodsäure, vergleichend überprüft. Beide Methoden arbeiten, insbesondere nach Einführung einer für die Serinoxydation vorgeschlagenen Abänderung, recht genau. Für die Untersuchung von Aminosäuregemischen oder Eiweißhydrolysaten ist aus erörterten und überprüften Gründen die Perjodat-Oxydation vorzuziehen. 相似文献
58.
A method was developed for the quantitative determination of alachlor, benalaxyl, clomazone, diflubenzuron, dimethomorph, diphenamid, ethofumesate, metalaxyl, methoprene, metobromuron and piperonyl butoxide on tobacco. The pesticides were extracted with water and methanol from five different types of tobacco. The extracts were purified by partition on an extraction cartridge containing diatomaceous earth. The purified extracts were analysed by reversed-phase high-performance liquid chromatography connected to an atmospheric pressure ionisation–electrospray-triple quadrupole mass spectrometer operating in the positive ion mode. Two different transitions and their relative intensities were monitored for unambiguous identification. All pesticides presented overall recovery rates between 35% and 110%. The trueness is near 100% and the interday precision is below 15%. The limits of quantifications are equal or below the guidance residue levels proposed by the Agrochemical Advisory Committee of CORESTA, an association of organisations having scientific research relative to tobacco. 相似文献
59.
Ali Elriati Jutta Loose Roswitha Mayrhofer Hans-Joachim Bergmann Hans-Hartwig Otto 《Monatshefte für Chemie / Chemical Monthly》2008,139(7):835-846
Different modifications of the imine – acyl chloride reaction were used for the synthesis of 3-mono- and 3,3-dihalogenated
1,4-diaryl substituted β-lactams. Furthermore, these β-lactams were modified by halogen substitution either at the aryl at
position 1 or at the aryl substituent at position 4, or at both positions. The influence of the halogen atoms on the reactivity
of the β-lactam ring, visible by the carbonyl frequence in their IR spectra, was studied. A selection of compounds was tested
as inhibitors of the serin protease porcine pancreatic elastase. No simple correlation between IR frequence and biological
activity was found. Finally, the base induced rearrangement of N-benzyl β-lactams was used for the synthesis of 4,5-diaryl substituted pyrrolidinones.
Correspondence: Hans-Hartwig Otto, Department of Pharmaceutical/Medicinal Chemistry (PMC), Institute of Pharmacy, Ernst-Moritz-Arndt-University,
17487 Greifswald, Germany. 相似文献
60.
Transitions of tethered polymer chains: a simulation study with the bond fluctuation lattice model 总被引:1,自引:0,他引:1
A polymer chain tethered to a surface may be compact or extended, adsorbed or desorbed, depending on interactions with the surface and the surrounding solvent. This leads to a rich phase diagram with a variety of transitions. To investigate these transitions we have performed Monte Carlo simulations of a bond fluctuation model with Wang-Landau and umbrella sampling algorithms in a two-dimensional state space. The simulations' density-of-states results have been evaluated for interaction parameters spanning the range from good- to poor-solvent conditions and from repulsive to strongly attractive surfaces. In this work, we describe the simulation method and present results for the overall phase behavior and for some of the transitions. For adsorption in good solvent, we compare with Metropolis Monte Carlo data for the same model and find good agreement between the results. For the collapse transition, which occurs when the solvent quality changes from good to poor, we consider two situations corresponding to three-dimensional (hard surface) and two-dimensional (very attractive surface) chain conformations, respectively. For the hard surface, we compare tethered chains with free chains and find very similar behavior for both types of chains. For the very attractive surface, we find the two-dimensional chain collapse to be a two-step transition with the same sequence of transitions that is observed for three-dimensional chains: a coil-globule transition that changes the overall chain size is followed by a local rearrangement of chain segments. 相似文献