Project proposal for the investigation of particle-stabilised emulsions and foams by microgravity experiments

The utilisation of particle-surfactants nanostructures as stabilising agents represents today the technologic and scientific frontier in the stabilisation of liquid films in emulsion and foams. This topic will be addressed by the proposal STEFAN (STabilisation of Emulsions and FoAms by Nanoparticles), proposed by European groups in the framework of the ESA AO-2004 for Life and Physical Sciences and Applied Research projects Similarly to what can be observed for surfactant-stabilised emulsions and foams, microgravity provides ideal conditions for the investigation of the hierarchy of involved objects: interfacial layer, liquid film, dispersed systems foam or emulsion. Microgravity experiments are planned by refurbishing the Experimental Container FASES for the ISS Fluid Science Laboratory and the facility FASTER for the European Drawer Rack, already under development in existing research programmes. Here the scientific guidelines of the project are presented together with examples and preliminary results on the effect of nano-particle-surfactant structures adsorbed at liquid interfaces. First experimental results have been achieved for particle monolayers at the water/air interface and a thermodynamic model was derived to describe the obtained surface pressure-area isotherms.     

Rheological studies with spherically shaped thin liquid films

The present work shows the first experimental and theoretical results for investigations on the rheology of liquid films. The experiments are planned to be performed under microgravity conditions. This environment will allow forming films of different thickness, which is impossible under ground conditions due to drainage. Then the films are forced to harmonic oscillations of the film area so that the film elasticity can be measured as a function of frequency. The presented theoretical model demonstrates the main relationships to be solved under corresponding boundary conditions     

Die Kalibrierung von Wärmeleitungsvakuummetern. The Calibration of Thermal Conductivity Vacuum Gauges

In many applications in the rough and fine vacuum thermal conductivity gauges are utilized. In order to determine the accuracy of the measuring values modern quality assurance systems require a regular calibration. The calibration laboratory of the German Calibration Service (DKD) at VACUUBRAND GMBH + CO KG features calibration equipment and procedures to calibrate vacuum gauges in the pressure range from 10^‐3 to 1000 mbar. The measuring techniques and calibration procedures are explained for thermal conductivity gauges with digital readouts. Besides general information on the calibration, particularities on thermal conductivity gauges and their effects on the calibration procedure are pointed out. The meaning of measuring deviation and measuring uncertainty and the interpretation of the calibration certificate for the user are discussed.     

欧洲和德国的钢铁工业的环保现状和发展(一)

欧洲钢铁工业的环境保护已经达到了很高的水平.20世纪60年代初,保护环境一般认为只是局限于限制工业对人们的影响.现在,尤其是在罗马协议(Club of Rome)的努力之下,环保的范围从节约资源延伸到整个自然环境的保护,而后产生了目前应用中的工业过程和产品生产周期.整体来说,保护环境的所有途径都被视为是未来平衡发展的先决条件. 欧盟环境保护技术的情况可以德国为例,更准确地说是杜伊斯堡的蒂森克虏伯钢厂(ThyssenKrupp Stahl AG),其粗钢产量约占德国总产量的35%. 钢铁工业环境保护的重点仍然是维护空气质量,在此目的下,进行除尘处理.由烟囱处取样获得目前的除尘水平来看,今后的除尘主要是控制粉尘扩散和减少细小微粒的排放. 钢铁工业环境保护的关键策略就是循环利用,它能起到与环境协调一致的作用,能够解决相关工艺中需要的大量的原料问题.德国的蒂森克虏伯钢厂(ThyssenKrupp Stahl AG)现在炉渣的综合回收率水平已接近95%,其中冶金渣的回收利用率尤为突出.在德国,高炉渣利用率达到了100%,同时炼钢渣的利用率也超过了90%,每吨粗钢的耗水量也控制在100 m3的范围内.大量的努力不仅保证了有效的回收和再生利用工序,而且冷却水的利用也保证了新水的补充率降低到每吨粗钢15m3左右. 污染控制除与主要环境即空气、水和土壤有关外,已扩展到回收过程再利用的水平,更多地重点渐渐地放到相关产品的环境保护.产品和原料却日益受到生产商和消费者的重点检验,有点与环境协调性标准相反.组织机构的环境保护手段包括环境管理系统的认可、生态平衡、政府部门的自愿协议以及提高公众的信息、教育水平. 欧洲的钢铁工业,当然也包括德国,都已经意识到环境保护的重要性同工业研究与开发的重要性处于同等地位.一个典型的例子就是超薄板汽车用钢项目,这个与产品相关的研究引入了35家合作厂商共同研究一个比目前传统的汽车车身更结实、更轻的项目.欧洲钢铁厂家的联合合作已经成功研究出应用于烧结厂的减少二恶英(dioxin)排放物的吸收工艺.用褐煤焦尘作为吸附剂,已能够平均减少排放物大约70%.很可能2003年在杜伊斯堡的ThyssenKrupp Stahl AG将被授权建全世界最先进的焦化厂.在这个项目过程中研究出的主要部分成果,例如低尘低烟煤湿熄法和减少PAH排放物的单室压力控制系统,会恰当地应用于新的工厂.另一个主要进步是ThyssenKrupp Stahl AG研制的Hamborn OxiCup竖炉,它有湿法冶炼和排除含铁残渣的功能.此技术预计成为回收利用铁水和钢产品中产生的粉尘和泥浆这一难题的解决方案. 德国的局势尤其显示出环境法规的落实正开始对经济发展和劳动力市场起到不利影响.盛行的经济技术条件需要合法的体制治理环境保护的合理化.将来任何进一步的措施都要考虑这一事实,既要获得可持续发展,又要考虑到经济发展和社会需求.     

Optimal Ordered Problem Solver

We introduce a general and in a certain sense time-optimal way of solving one problem after another, efficiently searching the space of programs that compute solution candidates, including those programs that organize and manage and adapt and reuse earlier acquired knowledge. The Optimal Ordered Problem Solver (OOPS) draws inspiration from Levin's Universal Search designed for single problems and universal Turing machines. It spends part of the total search time for a new problem on testing programs that exploit previous solution-computing programs in computable ways. If the new problem can be solved faster by copy-editing/invoking previous code than by solving the new problem from scratch, then OOPS will find this out. If not, then at least the previous solutions will not cause much harm. We introduce an efficient, recursive, backtracking-based way of implementing OOPS on realistic computers with limited storage. Experiments illustrate how OOPS can greatly profit from metalearning or metasearching, that is, searching for faster search procedures.     

Threshold photoionization in time-of-flight mass spectrometry

Multi-photon excitation in a time-of-flight mass spectrometer (TOF-MS) is shown to lead to threshold ions with defined internal energy. A powerful technique for the production of threshold ions is based on the excitation of high long-lived Rydberg states embedded in the ionization continuum. The Rydberg molecules are separated with suitable separation techniques from ions produced by a direct multi-photon ionization process. Finally, the ionization of the Rydberg molecules in a delayed pulsed electric field leads to threshold ions. This work reviews several separation techniques, and reports on applications of threshold ionization for investigation of the structure, energetics, and dynamics of neutral molecules, molecular cations, and cluster cations.     

Enantioseparations in Achiral Environments and Chromatographic Systems

Since the very first resolution of racemic tartaric acid by Pasteur, the importance of resolution and methodology has been on a path of continuous understanding and expansion. The science and chemistry of achieving such targets has changed a lot. The advent of chromatography changed the direction by involving synthetic, semisynthetic, or naturally occurring chiral materials for a direct approach to resolution, where rapid and reversible association occurs to form diastereomers with different stabilities and partition coefficients responsible for overall enantioseparation. It has now reached a stage where the separation of excess enantiomers from nonracemic mixtures has been achieved in a totally achiral environment, which does not appear to be in line with the prevalent concepts of basic stereochemistry. Caution should be exercised when enantiomerically enriched mixtures – obtained by enantioselective synthesis – are chromatographed for purification in preparative organic synthesis.     

Taxonomy for the Network and Service Management Research Field

Network and service management has established itself as a research field in the general area of computer networks. However, up to now, no appropriate organization of the field has been carried out in terms of a comprehensive list of terms and topics. In this paper, we introduce a taxonomy for network and service management. With such a taxonomy, it is possible to better understand the landscape of research as well as to reason about possible future challenges and opportunities. As such, in addition to the taxonomy itself, we also present an initial analysis of the field’s past, present, and future, based on the records of papers submitted and accepted in major conferences in the area, as well as a site survey performed through a questionnaire answered by experts from both industry and academia.     

Counting Fluorescent Dye Molecules on DNA Origami by Means of Photon Statistics

Obtaining quantitative information about molecular assemblies with high spatial and temporal resolution is a challenging task in fluorescence microscopy. Single‐molecule techniques build on the ability to count molecules one by one. Here, a method is presented that extends recent approaches to analyze the statistics of coincidently emitted photons to enable reliable counting of molecules in the range of 1–20. This method does not require photochemistry such as blinking or bleaching. DNA origami structures are labeled with up to 36 dye molecules as a new evaluation tool to characterize this counting by a photon statistics approach. Labeled DNA origami has a well‐defined labeling stoichiometry and ensures equal brightness for all dyes incorporated. Bias and precision of the estimating algorithm are determined, along with the minimal acquisition time required for robust estimation. Complexes containing up to 18 molecules can be investigated non‐invasively within 150 ms. The method might become a quantifying add‐on for confocal microscopes and could be especially powerful in combination with STED/RESOLFT‐type microscopy.     

Anticipation and flexibility in dynamic scheduling

Many real-world optimization problems change over time and require frequent re-optimization. We suggest that in such environments, an optimization algorithm should reflect the problem's dynamics and explicitly take into account that changes to the current solution are to be expected. We claim that this can be achieved by having the optimization algorithm search for solutions that are not only good, but also flexible, i.e. easily adjustable if necessary in the case of problem changes. For the example of a job-shop with jobs arriving non-deterministically over time, we demonstrate that avoiding early idle times increases flexibility, and thus that the incorporation of an early idle time penalty as secondary objective into the scheduling algorithm can greatly enhance the overall system performance.