Electrothermoelastic modeling of MEMS gripper

The design of many thermal Microelectromechanical (MEMS) actuators is often based on finite element analysis, but lacks analytical insight. In this paper we report a novel electro-thermal microgripper and a comprehensive thermal modeling of a general 5 lineshape microbeam’s actuator using 1-D steady state heat equations. Because of the variety of microgripper fabrication technologies and their applications, different thermal boundary conditions are considered for lifted off and attached grippers. Parametric and nonparametric electrothermomechanical identification models for silicon on insulator microgripper, fabricated on 100 μm device layer, are obtained.     

Evidence that leptin contributes to intestinal cholesterol absorption in obese (ob/ob) mice and wild-type mice

In the present study, the effect of leptin on intestinal cholesterol absorption was investigated in C57 BL/6 OlaHsd Lep^ob/Lep^ob obese (ob/ob) mice and lean C57 BL/6 (wild-type) mice. Animals were treated either with or without recombinant leptin for 2 wk. Cholesterol absorption was measured by the constant isotope feeding method and indirectly by the ratio of campesterol to cholesterol in serum. In ob/ob mice, cholesterol absorption was significantly higher compared to wild-type mice [83.4±2.3% (SD) vs. 77.6±1.5%, P<0.01]. Treatment with leptin significantly reduced cholesterol absorption in both ob/ob and wild-type mice by 8.5 (P<0.001) and 5.2% (P<0.05), respectively. Serum concentrations of campesterol and the ratio of campesterol to cholesterol in ob/ob mice were significantly higher compared to wild-type mice (2.2±0.3 mg/dL vs. 1.2±0.3 mg/dL, P<0.001; and 36.8±2.8 μg/mg vs. 28.0±3.3 μg/mg, P<0.001). After treatment of ob/ob mice with leptin, concentrations of campesterol and its ratio to cholesterol were significantly lower (2.2±0.3 mg/dL vs. 1.0±0.2 μg/mg, P<0.001; and 36.8±2.8 μg/mg vs. 13.2±2.2 μg/mg, P<0.001, respectively). In wild-type mice, the ratio of campesterol to cholesterol in serum was also significantly lower after treatment with leptin (28.0±3.3 μg/mg vs. 22.6±5.0 μg/mg, P<0.05). A significant positive correlation (r=0.701, P<0.01) between cholesterol absorption and the ratio of campesterol to cholesterol, in serum was found. It is concluded that leptin contributes to intestinal cholesterol absorption in ob/ob mice and lean wild-type mice.     

Branching rates and growth functions in the outgrowth of dendritic branching patterns

The outgrowth of dendritic branching patterns proceeds by neurite elongation and branching. These actions are supported by growth cones, specialized dynamic structures at the tips of outgrowing neurites, in response to a multitude of intracellular and extracellular signals and mechanisms. Branching rates of growth cones and their temporal patterns thus reflect the extent and changes in these responses. The present study outlines a model framework to relate branching rates of individual growth cones with the growth rate of the entire dendritic tree. The branching rate of an individual growth cone is assumed to depend on the total number of growth cones at any given moment (representing competition between growth cones), on its position along the dendrite, and on a baseline component representing all other factors. Four different strategies are discussed for determining quantitatively these components from experimental data. The methods are applied in the analysis of dendritic trees of Wistar rat multipolar non-pyramidal neurons, quantitatively reconstructed at several developmental stages (Parnavelas J G and Uylings H B M 1980 Brain Res. 193 373-82, Uylings H B M, Parnavelas J G, Walg H and Veltman W A M 1980 Mikroskopie 37 220-4). It is shown that the baseline branching rate is a rapidly decreasing function of time, indicating the largest baseline drive for branching in the early days of outgrowth.     

Design of a RFID case-based resource management system for warehouse operations

In the past, the selection of resources to execute various warehouse operation services was done solely by experts. In this paper, a RFID-based Resource Management System (RFID-RMS) is designed to help users to select the most suitable resource usage packages for handling warehouse operation orders by retrieving and analysing useful knowledge from a case-based data warehouse for solutions in both time saving and cost effective manner. In addition, a pure integral-linear programming model using a branch and bound algorithm to define the optimum travel distance of forklifts is also developed and embedded in the proposed system. The proposed system, which is suitable for usage in a warehouse operation environment, enhances the effectiveness in formulating resource usage package and managing resource operation by integrating the Radio Frequency Identification (RFID), case-based reasoning (CBR) technologies and the programming model for forklift route optimization. Through applying RFID-RMS in the GENCO Distribution System, a multinational logistics company, the utilization of warehouse resources is expected to be maximized while work efficiency will be greatly enhanced.     

Converging measurement of horizontal and vertical individualism and collectivism.

The constructs of horizontal (H) and vertical (V) individualism (I) and collectivism (C) were theoretically defined and empirically supported. Study 1 confirmed, via factor analysis, that the 4 constructs, HI, V1, HC, and VC, which were previously found in the United States, which has an individualist culture, also were found in Korea which has a collectivist culture. Study 2 investigated multimethod-multitrait matrices measuring the constructs and generally supported their convergent and divergent validity. Study 3 showed how these 4 constructs relate to previously identified components by H. C. Triandis and colleagues. Study 4 showed the relationships of the measurement of the 4 constructs to some of the measures used by other researchers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of polymer crystallinity from proton solid-echo NMR measurements

Summary The decomposition of the solid-echo curves of crystalline polymers into the crystalline and the amorphous component is discussed. The crystalline component is experimentally determined by using a special method of measurement. The amorphous component is assumed to correspond to a distribution of correlation times.Presented at the 22nd Microsymposium Characterization of Structure and Dynamics of Macromolecular Systems by NMR Methods, Prague, CSSR, July 20–23, 1981The author thanks Dr. H. Haberkorn for the determination of the x-ray crystallinities.     

Ein neuer Weg zur quantitativen Erfassung der Vorgänge beim kontrollierten Walzen

Qualitative Ableitung der Größe ?addierte Endverformung“ und ihre quantitative Beschreibung über temperaturabhängige Additionskoeffizienten. Vorausberechnung von Streckgrenze und Festigkeit aus dem Stichplan. Berechnung eines Übergangspunktes der Kristallinität und hieraus Konstruktion der Kerbschlagzähigkeitskurve.     

Carbonization of adamantane to a graphitizable carbon

Adamantane was carbonized in sealed tubes to 1073 K. Despite the non-planar molecular structure of adamantane, the resulting carbon was graphitizable. Using i.r. and u.v. spectrometry, mass spectrometry and X-ray diffraction, it was found that adamantane begins to decompose at ≈ 823 K to yield such planar molecules as phenanthrene, methyl-phenanthrene and pyrene. These molecules lead to a graphitizing carbon through a carbonization process which is similar to that of a pitch.