Determination of the distribution of air and water in porous media by electrical impedance tomography and magneto-electrical imaging

Monitoring the distribution of water content is essential for understanding hydrological processes in the lithosphere and the pedosphere. The movement of water in unsaturated rock formations and in the vadose zone is influenced by different processes (mainly infiltration, evaporation, percolation and capillary flow) which may be rate determining depending on the actual conditions. The interdependence of these processes also strongly influences the transport and distribution of solutes in the pore space. In order to gain a better understanding of the movement and distribution of water in unsaturated media, systematic investigations with non-invasive or minimal invasive methods appear to be most suitable. Studies on the distribution of electrical conductivity can improve risk analysis concerning waste disposals in general and nuclear waste repositories in particular. Induced polarization and magnetic flux density determined with two highly sensitive accessories yield additional information and may allow for better discrimination of coupled flow processes. Electrical impedance tomography (EIT) with 20 current injection and 48 voltage electrodes was used here to monitor the evaporation of tap water from a container filled with sand under laboratory conditions at 20 °C. The results are compared with data obtained by determining spectral induced polarization (SIP) of sand during desaturation in a multi-step outflow equipment. Infiltration processes and evaporation from sand saturated with 0.01 M CaCl₂ were determined by magneto-electrical resistivity imaging technique (MERIT). The results were obtained from a long-term experiment under controlled conditions.     

Intrinsic isotopic C labelling of polyphenols

The intrinsic isotopic labelling of plants with ¹³CO₂ is an effective method to generate highly labelled compounds using photosynthesis and avoiding labour-intensive complex organic syntheses. In this study, the intrinsic isotopic labelling of polyphenols in parsley, spinach and peppermint is shown for the first time. The plants were grown in an atmosphere where ¹²CO₂ was replaced by ¹³CO₂, in order to generate highly labelled compounds. The total content of ¹³C as well as the individual polyphenols were analysed by Isotopic Ratio-MS and HPLC–Iontrap-MSⁿ.     

中国国家图书馆二期暨国家数字图书馆

国家图书馆二期工程暨国家数字图书馆工程(以下简称新馆)位于北京市中关村路和新吴塔寺路交叉口,在原图书馆大楼的东侧,于2008年9月9日正式面向公众试运行.新图书馆包括书库区、阅览室和数字图书馆所需的全部功能.     

博根-贝尔森集中营纪念馆新文献和信息中心

这是一个长200米,宽18米,舒展而且具有纪念性的建筑--博根-贝尔森集中营纪念馆的新文献和信息中心.这个两层的建筑于2007年10月竣工,建筑面积6 163平方米,建筑容积25 300立方米.形式严格遵循功能的需求,在Heidewald森林的中央,原集中营的旁边,就像一个动态延伸的可进入雕塑.它的特殊建筑体量,极少主义的单色建筑外墙,没有任何装饰,以及巨大的体量上极少的建筑表面起伏与开窗,使建筑形成了强有力而意义深刻的表情.在关押受害人的地方,它以其自信而不唐突的方式表达了一个符合国际标准的纳粹罪行文献和研究中心功能及其重要历史意义的新形式,并且符合设计任务的要求.     

法兰克福贸易会展中心

如今,一个标志性的弯曲形态指示着法兰克福贸易会展中心的入口,使其更加引人注目.包含宴会大厅在内的论坛是该贸易会展中心的核心区域,它轻盈的结构和通透的立面,与其后面的固定展厅厚重而巨大的体量形成清晰的对比.     

Compact Thermal Model for the Transient Temperature Prediction of a Water-Cooled Microchip Module in Low Carbon Emission Computing

This article presents a compact computational model for the rapid determination of the junction temperature of a chip cooled with a heat sink, exploring the concept of hot water cooled electronics as a strategy to reduce the carbon footprint of data centers. The model aims at rapid simulations of variations of the chip, as well as the heat sink outlet water temperatures during transient heat loads. The model is validated by experimental tests with a water-cooled manifold microchannel (MMC) heat sink, which is designed to cool the processors of state-of-the-art servers. The chip temperature is determined subject to periodic heat loads as large as 100 W with frequencies in the range from 1 to 10 Hz. The results show that to calculate 1 s of real temperature variation requires less than 20 s of computational time on a Quad-Core AMD Opteron 2350, 2 GHz desktop PC with 4 GB RAM. The thermal response of the heat sink to real-time power traces with durations up to 200 s is modeled for different flow rates. The simulations indicate that application of a flow-control feedback loop could achieve more than 50% reduction in water flow rate, without compromising the maximal chip temperatures.     

Exact methods for the resource levelling problem

We present a project scheduling problem subject to general temporal constraints where the utilization of a set of renewable resources has to be smoothed over time. For solving the NP-hard optimization problem, we point out some important structural properties and introduce a new enumeration scheme. Combining this enumeration scheme with some branch-and-bound techniques, we propose an appropriate solution procedure for the project scheduling problem at hand. To outline the practical importance of resource levelling, we sketch exemplary the optimization of mid-term planning schedules with regard to the resource requirements of IT projects. Finally, we present results from a comprehensive computational study on problem instances of the well-known rlp_j10 and rlp_j20 test sets devised by Kolisch et al. (Benchmark Instances for Project Scheduling Problems, Kluwer, Boston, 1999).     

Trevira CS在装饰织物和家用纺织品领域的新进展

文章的第一部分报导了阻燃聚酯纤维床用和桌用织物方面的新进展。这些新发展涉及两个领域，舒适性是一个重要因素，但必要的性能也是不可少的，第二部分指导了对该纤维起球性和耐磨性的比较研究结果，表明了实验室中利用马丁代尔仪器测定的性能与作为家用织物进行实地测试的性能的相关程度，当与泡沫塑料复合在一起的时候，还可测定它的燃烧性能，这里对与Tre-vira CS复合的一系列泡沫塑料作了详细介绍。