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61.
Erica Perreca Franziska Eberl Maricel Valeria Santoro Louwrance Peter Wright Axel Schmidt Jonathan Gershenzon 《International journal of molecular sciences》2022,23(7)
White spruce (Picea glauca) emits monoterpenes that function as defensive signals and weapons after herbivore attack. We assessed the effects of drought and methyl jasmonate (MeJA) treatment, used as a proxy for herbivory, on monoterpenes and other isoprenoids in P. glauca. The emission of monoterpenes was significantly increased after MeJA treatment compared to the control, but drought suppressed the MeJA-induced increase. The composition of the emitted blend was altered strongly by stress, with drought increasing the proportion of oxygenated compounds and MeJA increasing the proportion of induced compounds such as linalool and (E)-β-ocimene. In contrast, no treatment had any significant effect on the levels of stored monoterpenes and diterpenes. Among other MEP pathway-derived isoprenoids, MeJA treatment decreased chlorophyll levels by 40%, but had no effect on carotenoids, while drought stress had no impact on either of these pigment classes. Of the three described spruce genes encoding 1-deoxy-D-xylulose-5-phosphate synthase (DXS) catalyzing the first step of the MEP pathway, the expression of only one, DXS2B, was affected by our treatments, being increased by MeJA and decreased by drought. These findings show the sensitivity of monoterpene emission to biotic and abiotic stress regimes, and the mediation of the response by DXS genes. 相似文献
62.
Abhishek Dutta Rahul P. Ekatpure Geraldine J. Heynderickx Axel de Broqueville Guy B. Marin 《Chemical engineering science》2010,65(5):1678-1693
Computational fluid dynamics (CFD) simulations of the hydrodynamic behavior of rotating fluidized beds in static geometry (RFB-SG) are carried out for gas–solid flows. The rotating motion of the reactor bed is induced by the tangential injection of the gas along the circumference of the fluidization chamber. Steep gradients in the gas velocity fields both in radial and tangential direction generate turbulence. The radial and tangential drag forces fluidize the particle bed in both radial and tangential direction.An Eulerian two-fluid model is used. Gas phase turbulence is accounted for by a k–ε model adapted for rotational flows. The RFB-SG simulations provide guidelines for a design and operation with a high efficiency in gas–solid momentum transfer, excellent gas–solid separation and limited solids losses. Hydrodynamic variables like the centrifugal force, the injection pressure, the radial and tangential slip velocities, solids hold-up are calculated for both polymer particles (300 μm, 950 kg/m3, Geldart Group B) and glass beads (70 μm, 2500 kg/m3, Geldart Group A) to allow for a comparison among different fluidization chamber designs. Unstable bed behavior, like slugging and channeling, is also numerically predicted. 相似文献
63.
Axel Wiegmann Manuel StavridisMonika Walzel Frank SiewertThomas Zeschke Michael SchulzClemens Elster 《Precision Engineering》2011,35(2):183-190
We present a virtual experiment for the accuracy assessment of the sub-aperture interferometric measurement of a synchrotron mirror involving several thousand sub-aperture topographies. The virtual experiment simulates the measurement process and accounts for the influence of positioning device errors, interferometer errors, non-perfect calibration of machine geometry as well as errors in the interferometer reference. Two principles are considered for reconstructing the form of a test specimen from the conducted sub-aperture topographies, a stitching procedure and a direct measurement method. The virtual experiments are applied to the task of absolute form measurement (including its radius of curvature) of a synchrotron mirror with a length of 30 cm, a width of 4 cm, a maximum curvature of about 44 mm−1 and a peak-to-valley of 5 mm. As a result, reconstruction accuracies can be expected to be in the range of 100 nm when the stitching method is applied, which outperforms the direct measurement method by a factor of about 3. 相似文献
64.
Dipl.-Wirt.Inf. Christian Czarnecki Prof. Dr. Axel Winkelmann Prof. Dr. rer.nat./Griechenland habil. Myra Spiliopoulou 《WIRTSCHAFTSINFORMATIK》2013,55(2):83-97
The telecommunication market is experiencing substantial changes. New business models, innovative services, and technologies require reengineering, transformation, and process standardization. Enterprise Architecture Frameworks support the transformation by specifying methods, procedures, and reference models. With the Enhanced Telecom Operation Map (eTOM), the TM Forum offers an international de facto reference process framework, based on specific features and requirements of the telecommunication industry. However, this reference framework only offers a hierarchical collection of processes on different levels of abstraction; a control view in terms of a sequential ordering of tasks and hence a real process flow as well as an end-to-end view on the customer are missing. In this paper, we extend the eTOM reference model by reference process flows, in which we abstract and generalize the knowledge about processes in telecommunication companies. With reference process flows, we aim to assist companies in achieving a structured and transparent re-structuring and re-design of their processes. We demonstrate the applicability and usefulness of our reference process flows in two case studies, and evaluate them by means of criteria for reference model evaluation. Our reference process flows have been accepted as a standard by the TM Forum and published as part of eTOM version 9. We further elaborate on those components of our approach which can be applied outside the telecommunication industry. 相似文献
65.
Axel Schultes 《The Journal of Architecture》2013,18(2):103-111
This paper, which continues the Libeskind/Lampugnani debate in Volume 1 Number 4 (followed up by Robert Maxwell in Volume 2 Number 1), is an edited version of the illustrated lecture delivered in Haifa, Tel-Aviv and Jerusalem in May 1996, and serves as prologue to the Autumn issue of The Journal of Architecture , devoted exclusively to Berlin. 相似文献
66.
Axel Pagán Josep Conde Alberto Ibarz Jordi Pagán 《Food and Bioproducts Processing》2010,88(2-3):77-82
This work studies the variation in the effluent content from the reactor in enzymatic peeling of grapefruits, to determine the loss of soluble solids, reducing sugars and galacturonic acid, the main component from the albedo of the skin to model the solid–liquid transfer in this process. Experiments to study the efficiency of the enzymatic reaction include the effect of the temperature on the kinetics of albedo degradation to find an equation relating both variables and also the activation energy of this process, its value being 36.9 kJ/mol. 相似文献
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The concept and use of a rotating chimney for compressing rotating fluidized beds is theoretically and experimentally studied. A rotating chimney is shown to drastically increase the operating flexibility of rotating fluidized beds and to allow a significant improvement of the particle bed uniformity. In particular, the rate of solids losses via the chimney can be reduced and bubbling can be suppressed by compressing the rotating particle bed. 相似文献
70.
Dipl. Wirt.-Inform. Ralf Knackstedt Dipl. Kfm. Axel Winkelmann 《WIRTSCHAFTSINFORMATIK》2006,48(1):47-59
Knowledge sharing is fundamental for innovations in the scientific community. The paper examines how the interaction of knowledge sharing is supported by online services. With respect to business information systems, a survey of online literature databases is given, providing an aggregation of various publication sources, a direct access to publications, and which are available to the public. Furthermore, special analysis services are presented which describe competitive interactions of knowledge sharing via rankings on the one hand, and cooperative interactions of knowledge sharing via co-authorship evaluation on the other. 相似文献