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Two Types of Liquid Phase Separation Induced by Soft Centrifugation in Aqueous Ethyl Acetate Using Ethanol as Cosolvent

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Research 2023年第3期6卷 451-460页

作者： Helmut Cölfen Rose Rosenberg dirk Haffke Simon Stemplinger Thomas Zemb Dominik Horinek Physical Chemistry Department of ChemistryUniversity of KonstanzUniversitätsstr.10D-78457 KonstanzGermany Institute for Separation Chemistry ICSM U Montpellier/CEA/CNRS/ENSCM MarcouleFrance Institute of Physical and Theoretical Chemistry University of RegensburgD-93040 RegensburgGermany

Water/ethyl acetate/ethanol is widely used as a“green”extractant *** show that 2 different types of phase separation can be induced upon centrifugation in this ternary system using ethanol as a cosolvent of water and ethyl acetate:centrifuge-induced criticality and centrifuge-induced *** expected composition profiles of samples after centrifugation can be represented by bent lines in a ternary phase diagram when gravitational energy is added to the free energy of *** experimental equilibrium composition profiles behave qualitatively as expected and can be predicted using a phenomenological theory of *** concentration gradients are small except near the critical point,as expected for small ***,they are usable when accompanied by temperature *** findings open new possibilities of centrifugal separation,even if control is delicate during temperature *** schemes are accessible even at relatively low centrifugation speed for molecules that float and sediment with apparent molar masses several hundred times larger than the molecular mass.

关键词： separation ternary apparent

Roughness Measurements with Polychromatic Speckles on Tilted Surfaces

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Nanomanufacturing and Metrology 2021年第4期4卷 237-246页

作者： Johannes Stempin Andreas Tausendfreund dirk Stobener Andreas Fischer Bremen Institute for Metrology Automation and Quality ScienceUniversity of BremenLinzer Str.1328359 BremenGermany

Surface light scattering enables contactless and fast measurements of surface roughness.A surface inclination alters the direction of the scattering beam and thus the measured surface roughness is calculated from the detected intensity ***,an accurate sensor-surface alignment is *** order to achieve tilt-independent roughness measurements,a model-based evaluation approach for polychromatic speckle patterns is *** evaluating the shape of the superposed speckles,which occur for polychromatic illumination,with regard to the distance to the scattering centre,surfaces with an Sa roughness value in the range of 0.8-3.2μm are *** investigations demonstrate that the influence of a surface tilt up to±1.25°on the roughness measurement is reduced by 90%.As a result,the robustness of the polychromatic speckle roughness measurement is improved,which allows to speed up the adjustment of the measurement system or the surface sample,respectively.

关键词： Surface roughness Polychromatic light scattering Surface tilting In-process measurement

Spatial risk assessment of opium poppy cultivation in Afghanistan: integrating environmental and socio-economic drivers

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International Journal of Digital Earth 2017年第7期10卷 719-736页

作者： Stefan Kienberger Raphael Spiekermann dirk Tiede Irmgard Zeiler Coen Bussink Department of Geoinformatics–Z_GIS University of SalzburgSalzburgAustria Landcare Research Manawatu Mail CentrePalmerston NorthNew Zealand Research and Trend Analysis Branch United Nations Office on Drugs and Crime(UNODC)ViennaAustria

Recently the cultivation of opium poppy in Afghanistan reached unprecedented *** is agreed that the complex and coupled interactions of social,economic and environmental drivers are crucial for understanding the spatial and temporal dynamics of opium poppy cultivation in *** this context,we present an integrated risk concept,which considers environmental and socio-economic drivers of opium poppy cultivation.A set of spatially explicit indicators for the environmental suitability and socio-economic vulnerability was established and populated from a variety of ***,novel methods of modelling homogeneous and spatially explicit regions of opium poppy cultivation suitability,socio-economic vulnerability and risk are developed and *** risk assessment results demonstrate the complex nature of the illicit crops production in Afghanistan and prompt a more profound examination of the drivers of opium poppy cultivation in a spatial *** study also confirms what has already been widely discussed in literature:that reasons for cultivation are spatially diverse and often distinct,meaning that any formulation of generalized explanations cannot be drawn without ignoring a more complex ***,an integrative spatial view of risk,which integrates the social dimension as well as environmental parameters,is required to better identify context-specific intervention measures.

关键词： Opium poppy risk social and environmental determinants integrated modelling policy support regionalization integrated geons

The pseudo-homogeneous flow regime in large-scale bubble columns:experimental benchmark and computational fluid dynamics modeling

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Petroleum 2019年第2期5卷 141-160页

作者： Giorgio Besagni Fabio Inzoli Thomas Ziegenhein dirk Lucas Department of Energy Politecnico di MilanoVia Lambruschini 4a20156MilanItaly Helmholtz-Zentrum Dresden-Rossendorf e.V.Institute of Fluid Dynamics 01314 DresdenGermany

A precise prediction of the fluid dynamics in bubble columns is of fundamental importance to correctly design“industrial-scale”*** is known that the fluid dynamics in bubble columns is related to the prevailing bubble size distribution existing in the *** this respect,multiphase computational fluid dynamic simulations,in the Eulerian multi-fluid framework,are able to predict the local bubble size distributions and,thus,the global fluid dynamics from the fluid flow conditions and by applying modeling *** particular,in in“industrial-scale”reactors,owing to the large gas sparger openings,the“pseudo-homogeneous”flow regimedcharacterized by a wide spectrum of bubble sizesdis typically ***,reliable predictions of the“pseudo-homogeneous”flow regime are limited up to now:one important drawback concerns the selection of appropriate models for the coalescence and break-up.A set of closure relations was collected at the Helmholtz-Zentrum Dresden-Rossendorf that represents the best available ***,the authors have extended the validation of this set of closure relations to the“pseudo-homogeneous”flow regime,by comparing the numerical predictions to a comprehensive experimental dataset(gas holdup,bubble size distributions and local flow measurements).Unfortunately,the previous study suffers from some limitations;in particular,in the previous experimental dataset,the bubble size distributions concerned only one axial position and a detailed characterization of the gas sparger was *** study contributes to the existing discussion and proposed a step ahead in the study of the“pseudo-homogenous”flow *** this end,we propose an experimental study,to improve the comprehensive dataset previously *** novel datasetdobtained for two gas velocitiesdconcerns bubble size distributions at different axial and radial positions and a precise characterization of the gas *** comprehensive bubble size distribution

关键词： CFD Bubble column Large-scale Bubble size distribution Coalescence and break-up Validation

Manufacturing of Long Products Made of Innovative Lightweight Materials

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Acta Metallurgica Sinica(English Letters) 2015年第12期28卷 1496-1502页

作者： Karsten Richter Roland Müller Andreas Kunke Verena Kr? usel dirk Landgrebe Fraunhofer Institute for Machine Tools and Forming Technology (IWU) Professorship Forming and Joining (UFF) Technische Universit?t Chemnitz

The processing of innovative lightweight materials to sheet metal components and assemblies with globally or locally defined properties is the object of this work. It takes a load-dependent design of components and assemblies, for example, based on the composition of different construction materials or a targeted setting of component areas with specified characteristics to fully exploit the lightweight potential when substituting conventionally used materials. Different process chains for the manufacturing of roll-formed long products made of magnesium alloys and high-strength steels with locally defined properties will be presented in this paper. Depending on the kind of material to be formed and the desired product characteristics, different temperature managements are needed for capable processes. Due to limited formability at room temperature, magnesium alloys require a heating of the forming zones above 200–225 °C throughout the bending process in order to activate additional gliding planes and to avoid any failures in the radii. The realization of local hardening effects requires at least one process-integrated heat treatment when roll forming manganese–boron steels. For both processes, it is imperative to realize a heating and cooling down or quenching appropriate for the manufacturing of long products with the required quality. Additionally, proper line speeds that allow a continuously operated economical production have to be considered. Research results including design, FEA, realization and experimentation of the mentioned process chains and strategies will be described in detail.

关键词： Roll forming Heat treatment Lightweight component Light metals Manganese steels AZ31 magnesium alloy

Structure and Function of TPC1 Vacuole SV Channel Gains Shape

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Molecular Plant 2018年第6期11卷 764-775页

作者： Rainer Hedrich Thomas D. Mueller dirk Becker Irene Marten Institute for Molecular Plant Physiology and Biophysics University of Wurzburg Julius-yon-Sachs Platz 2 97082 Wurzburg Germany

Plants and animals in endosomes operate TPCI/SV-type cation channels. All plants harbor at least one TPC1 gene. Although the encoded SV channel was firstly discovered in the plant vacuole membrane two decades ago, its biological function has remained enigmatic. Recently, the structure of a plant TPC1/SV channel protein was determined. Insights into the 3D topology has now guided site-directed mutation ap- proaches, enabling structure-function analyses of TPC1/SV channels to shed new light on earlier findings. Fou2 plants carrying a hyperactive mutant form of TPC1 develop wounding stress phenotypes. Recent studies with fou2 and mutants that lack functional TPC1 have revealed atypical features in local and long-distance stress signaling, providing new access to the previously mysterious biology of this vacuolar cation channel type in planta.

关键词： Ca^2+ sensors TPC1/SV channel vacuole membrane voltage voltage sensor

Targeting of Vacuolar Membrane Localized Members of the TPK Channel Family

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Molecular Plant 2008年第6期1卷 938-949页

作者： Marcel Dunkel Andreas Latz Karin Schumacher Thomas Muller dirk Becker Rainer Hedrich Molecular Plant Physiology and Biophysics Julius-von-Sachs-lnstitute University of W0rzburg Julius-von-Sachs-Platz 2 97082 Worzburg Germany Heidelberger Institut fur Pflanzenwissenschaften (HIP) University of Heidelberg Im Neuenheimer Feld 230 69120 Heidelberg Germany (K.S.) Present address: Physiological Ecology of Plants University ot T(3bingen Aut der Morgenstelle 1 72016 Tubingen Germany

Four members of the tandem-pore potassium channel family of Arabidopsis thaliana （TPK1, 2, 3, and 5） reside in the vacuolar membrane, whereas TPK4 is a plasma membrane K^＋-channel. By constructing chimeras between TPK1 and TPK4, we attempted to identify channel domains involved in the trafficking process and found that the TPK1 cytoplasmic C-terminal domain （CT） is critical for the ERas well as Golgi-sorting steps. Following site-directed mutagenesis, we identified a diacidic motif （DLE） required for ER-export of TPK1. However, this diacidic motif in the C-terminus is not conserved among other members of the TPK family, and TPK3 sorting is independent of its CT. Moreover, the 14-3-3 binding site of TPK1, essential for channel activation, is not involved in channel sorting.

关键词： Vacuolar Membrane TPK Channel Family Arabidopsis thaliana

Is the Polar Relative Monodromy of Finite Order? An Example

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Chinese Quarterly Journal of Mathematics 1995年第4期10卷 78-85页

作者： dirk SIERSMA Miha Mathematisch Instituut Universiteit Utrecht P.O.Box

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关键词：解析函数单值定理有限阶极相对单值

Signal Processing for Fast Fault Detection in HVDC Grids

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CSEE Journal of Power and Energy Systems 2018年第4期4卷 469-478页

作者： Willem Leterme Mike Barnes dirk Van Hertem EnergyVille/Electa research group Electrical Engineering Department ESATKU LeuvenBelgium Power Conversion Research Group School of Electrical and Electronic EngineeringUniversity of ManchesterManchester M139PLUK

For multiterminal or meshed Voltage Source Converter(VSC)High-voltage Direct Current(HVDC)systems,high speed protection against DC faults is essential,as power electronic components cannot withstand the rapidly increasing fault currents which would otherwise *** proposed DC fault detection methods were developed based on time domain simulations in EMT-type software,which requires considerable modeling and computational efforts and results in methods specifically designed for the HVDC grid under *** simplify the initial design of DC fault detection methods,this paper proposes general guidelines based on fundamental theory and offers a reduced modeling ***,the impact of non-ideal measurements is investigated and a method to choose the filters that optimally discriminate these fault signals from noise,is *** approach was evaluated in a case study on fault detection in a realistically dimensioned HVDC *** paper shows that the initial design of fast fault detection methods can be based on the relatively simple proposed guidelines and reduced *** paper furthermore shows that a sufficiently high sampling frequency and a filter matched to the fault signal enable fault detection within hundreds of microseconds and discrimination of DC faults from transients not related to DC faults.

关键词： HVDC matched filter measurement power system faults power system transients