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101.
Louis de Grange Enrique Fernández Joaquín de Cea Magdalena Irrazábal 《Networks and Spatial Economics》2010,10(4):551-578
A methodology is proposed for estimating a combined transportation model that accommodates spatial aggregation. It employs
maximum likelihood estimation using a joint probability function that includes destination and mode choice simultaneously.
The main contribution of the paper is the incorporation of a spatial aggregation strategy to validate the method when the
survey data are insufficient. By aggregating small zones into larger districts, estimation of the trip distribution parameters
can be achieved with limited data, while mode choice continues to be estimated using disaggregated data. Our results demonstrate
that including trip distribution in the travel decision induces variations in the utility function parameter estimators obtained
for the different travel modes when only mode choice is estimated. The methodology thus corrects omission bias. 相似文献
102.
To increase the fractional energy savings achieved with solar thermal combisystems the store volume may be increased. Installation of large stores in single-family houses is, however, often limited by space constraints. In this article the influence of the store dimensions, as well as internal and external auxiliary volume configurations, are investigated for large solar water stores by annual dynamic TRNSYS simulations. The results show that store sizes up to 4 m3 may be used in solar heating systems with 30 m2 collector area. It is further shown that well-insulated stores are rather insensitive to the geometry. Stores deviating from the conventional dimensions still yield high fractional energy savings. Furthermore, the simulations show that the performance of an internal auxiliary volume configuration in most cases exceeds that of a solution with an external auxiliary unit. The practical limitations of very thin auxiliary volumes must, however, be further investigated. 相似文献
103.
Andres Castellanos‐Gomez Magdalena Wojtaszek Nikolaos Tombros Nicolás Agraït Bart J. van Wees Gabino Rubio‐Bollinger 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(17):2491-2497
By mechanical exfoliation, it is possible to deposit atomically thin mica flakes down to single‐monolayer thickness on SiO2/Si wafers. The optical contrast of these mica flakes on top of a SiO2/Si substrate depends on their thickness, the illumination wavelength, and the SiO2 substrate thickness, and can be quantitatively accounted for by a Fresnel‐law‐based model. The preparation of atomically thin insulating crystalline sheets will enable the fabrication of ultrathin, defect‐free insulating substrates, dielectric barriers, or planar electron‐tunneling junctions. Additionally, it is shown that few‐layer graphene flakes can be deposited on top of a previously transferred mica flake. Our transfer method relies on viscoelastic stamps, as used for soft lithography. A Raman spectroscopy study shows that such an all‐dry deposition technique yields cleaner and higher‐quality flakes than conventional wet‐transfer procedures based on lithographic resists. 相似文献
104.
Magdalena Graczyk-Zajac Gabriela Mera Jan Kaspar Ralf Riedel 《Journal of the European Ceramic Society》2010,30(15):3235-3243
The electrochemical behavior of poly(phenylvinylsilylcarbodiimide)-derived SiCN ceramics as anode material for lithium-ion batteries is reported here for the first time. The novel carbon-rich silicon carbonitride (SiCN) ceramics have been synthesized by the thermal treatment of poly(phenylvinylsilylcarbodiimide) under argon atmosphere at five temperatures, namely 1100, 1300, 1500, 1700 and 2000 °C. The SiCN electrodes were prepared without any conducting additives and were tested in electrochemical two electrodes cell using cyclic voltammetry and galvanostatic techniques. The capacity of the carbon-rich SiCN samples was found to be stable upon galvanostatic cycling and reaches almost 300 mAh/g for the sample prepared at 1300 °C with oxygen as the impurity. The dependence of the microstructure, especially of the crystallinity of the segregated carbon phase and of the oxygen impurities on the electrochemical behavior of the SiCN material, was analysed. At all temperatures of thermolysis, the free carbon phase has been identified as “soft carbon”. 相似文献
105.
The circular dichroism (CD) spectra in visible range of the 3-nitroaniline (m-NA) single crystal, of its solution in chloroform, and in the KBr pellet were recorded. Neither the molecular (m or Cs) nor the crystal (mm2 or C2v) point groups belong to the chiral groups. The DFT calculation of CD spectrum of the m-NA isolated neutral molecule confirmed its chirality. The red shifted bands in the calculated CD spectrum of m-NA radical anion (charged polaron), as compared with the neutral molecule, resemble better the spectra of solids than that of the solution. It seems that these facts corroborate qualitatively the “hop and turn” model explaining the m-NA optical nonlinearity and electric conductivity proposed in Szostak et al. [M.M. Szostak, H. Chojnacki, E. Staryga, M. D?u?niewski, G. B?k, Chem. Phys. 365 (2009) 44-52]. 相似文献
106.
Luis Magdalena 《国际智能系统杂志》2002,17(5):471-493
107.
Susanna C. Scholtz & Magdalena J. C. Bosman 《International Journal of Food Science & Technology》2005,40(8):857-866
The acceptance of, preference for and consumption intent for high‐fibre muffins and/or rusks baked with either red palm olein (RPO) or sunflower oil (SFO, as control) were evaluated by two consumer groups of 144 and 67 consumers, respectively, in order to determine the possibility of their successful inclusion as carriers for oils in a subsequent nutrition intervention trial. A five‐point hedonic and food action rating scale was used for sensory evaluation. SFO muffins and rusks scored significantly higher than RPO products on a number of hedonic dimensions and were thus more acceptable to the average consumer. Sensory attributes of SFO and RPO products received high scores by consumers from both groups (≥4.0 on five‐point scale), and consumers intended to eat them often (at least one per day). The RPO products were satisfactory in terms of acceptance and complied with requirements for use in the subsequent nutrition intervention trial. 相似文献
108.
Mario Rothbauer Peter Ertl Barbara A. Theiler Magdalena Schlager Uwe B. Sleytr Seta Küpcü 《Advanced Materials Interfaces》2015,2(1)
The spatial arrangement of cells in their microenvironment is known to significantly influence cellular behavior, thus making the control of cellular organization an important parameter of in vitro co‐culture models. However, recent advances in micropatterning co‐culture methods within biochips do not address the simultaneous cultivation of anchorage‐dependent and non‐adherent cells. To address this methodological gap we combine S‐layer technology with microfluidics to pattern co‐cultures to study the cell‐to‐cell and cell‐to‐surface interactions under physiologically relevant conditions. We exploit the unique self‐assembly properties of SbpA and SbsB S‐layers to create an anisotropic protein nanobiointerface on‐chip with spatially‐defined cytophilic (adhesive) and cytophobic (repulsive) properties. While microfluidics control physical parameters such as shear force and flow velocities, our anisotropic protein nanobiointerface regulates the biological aspects of the co‐culture method including biocompatibility, biostability, and affinity to non‐adherent cells. The reliability and reproducibility of our microfluidic co‐culture strategy based on laminar flow patterned protein nanolayers is envisioned to advance in vitro models for biomedical research. 相似文献
109.
Ihab El Sawi Zouheir Fawaz Redouane Zitoune Habiba Bougherara 《Journal of Materials Science》2014,49(5):2338-2346
In this paper we investigated the fatigue damage of a unidirectional flax-reinforced epoxy composite using infrared (IR) thermography. Two configurations of flax/epoxy composites layup were studied namely, [0]16 unidirectional ply orientation and [±45]16. The high cycle fatigue strength was determined using a thermographic criterion developed in a previous study. The fatigue limit obtained by the thermographic criterion was confirmed by the results obtained through conventional experimental methods (i.e., Stress level versus Number of cycles to failure). Furthermore, a model for predicting the fatigue life using the IR thermography was evaluated. The model was found to have a good predictive value for the fatigue life. In order to investigate the mechanism of damage initiation in flax/epoxy composites and the damage evolution, during each fatigue test we monitored the crack propagation for a stress level and at different damage stages, a direct correlation between the percentage of cracks and the mean strain was observed. 相似文献
110.
Magdalena Rohrbeck JProf. Dr. Christian Fischer Prof. Dr. Stefan Wehner Dr. Jutta Meier Prof. Dr. Werner Manz 《真空研究与实践》2014,26(2):42-47
Polymers made of renewable resources increasingly replace conventional plastic materials made of petroleum. Socalled bioplastics can be found e. g. in food industry, for agricultural usage or in the medical field. The range of applications can be further expanded with specialized coating of their surface. Especially in case of food packaging and the usage within medical devices as well as the storage of these composite materials, sterilization or at least the partial reduction of microbial growth is an important issue which needs to be addressed early in the production process. In this work, a commercially available polyhydroxyalkanoate (PHA) pure bioplastic foil of 50 μm thickness was coated with 100 nm of diamond‐like carbon (DLC) and afterwards treated by four different standard methods of sterilization and / or disinfection, namely deep‐freezing, ultraviolet irradiation, autoclaving and immersion in ethanol. The surface morphology of treated DLC‐coated and uncoated samples was investigated and compared to the untreated DLC‐coated and uncoated samples using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Measurements exhibited damage of the composite for autoclaved and in ethanol immersed samples, whereas deep‐frozen and ultraviolet irradiated samples showed no structural changes. These findings clearly demonstrate deep‐freezing and ultraviolet irradiation to be appropriate methods for the disinfection and sterilization, respectively, of the DLC‐coated pure bioplastic foil. 相似文献