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11.
Directed exploitation of biological systems . During the past few decades, our knowledge of molecular process responsible for genetics has increased dramatically. Discovery of the giant molecule deoxyribonucleic acid – abbreviated as DNA – as the carrier of genetic information heralded in a development which nowadays permits us to effect directed changes in the genetic material of an organism. Thus we can provide easily cultured microorganisms with genes which were previously located in a completely different genetic environment. This helps us to obtain high yields of proteins or other substances which were formerly very difficult to obtain. Higher organisms such as animals and plants can also undergo modification of their genetic equipment. This adds a new dimension to the breeding of such species. Above all, genetic engineering provides new insights into the enormously complex interplay of molecules which go to make up a living cell. The resulting understanding of life processes on a molecular level permits recognition of malfunction and therapy of the ensuring disease by new drugs. In addition to these positive aspects, genetic engineering provides scope for conducting experiments whose ethical implications demand very earnest consideration. 相似文献
12.
The heterogeneous bulk polymerization of acrylonitrile initiated by AIBN has been studied by means of an improved dilatometric technique and a new method of analysis, where the initial reaction rate (vw)0 results from the intercept of a straight line in a \documentclass{article}\pagestyle{empty}\begin{document}$ \frac {\ln \left( 1 \hbox{---} {\rm U} \right)} {{\rm e}^{{- 0,5} {\rm k}_{\rm s}{\rm t} \hbox{---} 1}}$\end{document} versus t plot. It has been found that the initial reaction rate is proportional to the square root of the initial catalyst concentration S0. The ratio of the rate coefficients of propagation and termination\documentclass{article}\pagestyle{empty}\begin{document}$\frac { {\rm k}_{\rm a} } { {\rm k}_{ {\rm w}^{2} } } $\end{document} could be calculated from the slope of a straight line passing through the origin in a plot of (vw)0 versus \documentclass{article}\pagestyle{empty}\begin{document}$\sqrt { {\rm S}_{0} }$\end{document} and yielded a value of 280 mol 1?1. 相似文献
13.
Oscar Ljungkrantz Knut Åkesson Martin Fabian Amir Hossein Ebrahimi 《Empirical Software Engineering》2014,19(3):655-677
This paper presents an empirical study of control logic specifications used to document industrial control logic code in manufacturing applications. More than one hundred input/output related property specifications from ten different reusable function blocks were investigated. The main purpose of the study was to provide understanding of how the specifications are expressed by industrial practitioners, in order to develop new tools and methods for specifying control logic software, as well as for evaluating existing ones. In this paper, the studied specifications are used to evaluate linear temporal logic in general and the specification language ST-LTL, tailored for functions blocks, in particular. The study shows that most specifications are expressed as implications, that should always be fulfilled, between input and output conditions. Many of these implications are complex since the input and output conditions may be mixed and involve sequences, timer issues and non-boolean variables. Using ST-LTL it was possible to represent all implications of this study. The few non-implication specifications could be specified in ST-LTL as well after being altered to suit the specification language. The paper demonstrates some advantages of ST-LTL compared to standard linear temporal logic and discusses possible improvements such as support for automatic rewrite of complex specifications. 相似文献
14.
Björn Sten Mark Kretzschmar Paul Bergelt Daniel Göhler Fabian Firmbach Ronny Köcher Andreas Heft 《Aerosol science and technology》2020,54(10):1124-1134
Abstract For the purpose of silica surface layer modulation, a pneumatic-controlled two-substance atomizer with inertia-based coarse droplet separation was operated at different system pressures for tetraethyl orthosilicate precursor aerosol supply during combustion chemical vapor deposition. A comprehensive testing study was performed to characterize the atomizer’s performance characteristics, initial precursor aerosols at the atomizer’s outlet, transformed aerosols before combustion, combustion aerosols and formed layers. Laser diffraction spectrometry, differential electrical mobility analyses and condensation particle counting were used for aerosol characterization with regard to particle size and particle production quantities. Layers were characterized by scanning electron microscopy, atomic force microscopy, spectral ellipsometry, water contact angle measurements and light transmission concerning geometric properties (thickness, surface structure and roughness) and physical behaviors (i.e., optical behaviors, hydrophobicity). Results show a quasi-linear relationship of the ejection mass flow of the pneumatic-controlled atomizer and geometric layer properties which again show a direct relationship to the physical properties. No correlation was found between the aerosols before combustion and the combustion aerosols since the majority of combustion aerosol particles are synthesized solely from the gas phase based on evaporated precursor material. Copyright © 2020 American Association for Aerosol Research 相似文献
15.
Tomaschek Fabian Arnold Denis Sering Konstantin Strauss Friedolin 《Language Resources and Evaluation》2021,55(4):1127-1140
Language Resources and Evaluation - This report presents a corpus of articulations recorded with Schlieren photography, a recording technique to visualize aeroflow dynamics for two purposes. First,... 相似文献
16.
Fabian Aulkemeier Mohammad Anggasta Paramartha Maria-Eugenia Iacob Jos van Hillegersberg 《Information Systems and E-Business Management》2016,14(3):469-489
In the beginning of the e-commerce era, retailers mostly adopted vertically integrated solutions to control the entire e-commerce value chain. However, they began to realize that to achieve agility, a better approach would be to focus on certain core capabilities and then create a partner ecosystem around them. From a technical point of view, this means it is advised to have a lightweight platform architecture with small core e-commerce functionality which can be extended by additional services from third party providers. In a typical e-commerce ecosystem with diverse information systems of network partners, integration and interoperability become critical factors to enable seamless coordination among the partners. Furthermore an increasing adoption of cloud computing technology could be observed resulting in more challenging integration scenarios involving cloud services. Thus, an e-commerce platform is required that suites the advanced needs for flexible and agile service integration. Therefore, this paper aims to present a reference architecture of a novel pluggable service platform for e-commerce. We investigate on currently available online shop platform solutions and integration platforms in the market. Based on the findings and motivated by literature on service-oriented design, we develop an architecture of a service-based pluggable platform for online retailers. This design is then instantiated by means of a prototype for an e-commerce returns handling scenario to demonstrate the feasibility of our architecture design. 相似文献
17.
Topology optimization of a cantilevered piezoelectric energy harvester using stress norm constraints
Fabian Wein Manfred Kaltenbacher Michael Stingl 《Structural and Multidisciplinary Optimization》2013,48(1):173-185
Vibrational piezoelectric energy harvesters are devices which convert ambient vibrational energy into electric energy. Here we focus on the common cantilever type in which an elastic beam is sandwiched between two piezoelectric plates. In order to maximize the electric power for a given sinusoidal vibrational excitation, we perform topology optimization of the elastic beam and tip mass by means of the SIMP approach, leaving the piezoelectric plates solid. We are interested in the first and especially second resonance mode. Homogenizing the piezoelectric strain distribution is a common indirect approach increasing the electric performance. The large design space of the topology optimization approach and the linear physical model also allows the maximization of electric performance by maximizing peak bending, resulting in practically infeasible designs. To avoid such problems, we formulate dynamic piezoelectric stress constraints. The obtained result is based on a mechanism which differs significantly from the common designs reported in literature. 相似文献
18.
Marquardt CL Cooper DG Budni PA Knights MG Schepler KL Dedomenico R Catella GC 《Applied optics》1994,33(15):3192-3197
We performed an experimental investigation of thermal lensing in silver gallium selenide (AgGaSe(2)) optical parametric oscillator crystals pumped by a 2-μm laser at ambient temperature. We determined an empirical expression for the effective thermal focusing power in terms of the pump power, beam diameter, crystal length, and absorption coefficient. This relation may be used to estimate average power limitations in designing AgGaSe(2) optical parametric oscillators. We also demonstrated an 18% slope efficiency from a 2-μm pumped AgGaSe(2) optical parametric oscillator operated at 77 K, at which temperature thermal lensing is substantially reduced because of an increase in the thermal conductivity and a decrease in the thermal index gradient dn/dT. Cryogenic cooling may provide an additional option for scaling up the average power capability of a 2-μm pumped AgGaSe(2) optical parametric oscillator. 相似文献
19.
Yannick Schellander Marius Winter Maurice Schamber Fabian Munkes Patrick Schalberger Harald Kuebler Tilman Pfau Norbert Fruehauf 《Journal of the Society for Information Display》2023,31(5):363-372
In this work, real-time ultraviolet photodetectors are realized through metal–semiconductor–metal (MSM) structures. Amorphous indium gallium zinc oxide (a-IGZO) is used as semiconductor material and gold as metal electrodes. The readout of an individual sensor is implemented by a transimpedance amplifier (TIA) consisting of an all-enhancement a-IGZO thin-film transistor (TFT) operational amplifier and a switched capacitor (SC) as feedback resistance. The photosensor and the transimpedance amplifier are both manufactured on glass substrates. The measured photosensor possesses a high responsivity R , a low response time t R E S , and a good noise equivalent power value NEP . 相似文献
20.
Giuseppe Antonio Elia Krystan Marquardt Katrin Hoeppner Sebastien Fantini Rongying Lin Etienne Knipping Willi Peters Jean‐Francois Drillet Stefano Passerini Robert Hahn 《Advanced materials (Deerfield Beach, Fla.)》2016,28(35):7564-7579
A critical overview of the latest developments in the aluminum battery technologies is reported. The substitution of lithium with alternative metal anodes characterized by lower cost and higher abundance is nowadays one of the most widely explored paths to reduce the cost of electrochemical storage systems and enable long‐term sustainability. Aluminum based secondary batteries could be a viable alternative to the present Li‐ion technology because of their high volumetric capacity (8040 mAh cm?3 for Al vs 2046 mAh cm?3 for Li). Additionally, the low cost aluminum makes these batteries appealing for large‐scale electrical energy storage. Here, we describe the evolution of the various aluminum systems, starting from those based on aqueous electrolytes to, in more details, those based on non‐aqueous electrolytes. Particular attention has been dedicated to the latest development of electrolytic media characterized by low reactivity towards other cell components. The attention is then focused on electrode materials enabling the reversible aluminum intercalation‐deintercalation process. Finally, we touch on the topic of high‐capacity aluminum‐sulfur batteries, attempting to forecast their chances to reach the status of practical energy storage systems. 相似文献