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1.
2.
A new system based on the harnessing of solar and wind power is presented for heat dissipation in air conditioning facilities. The innovation offered by the new system is the integration of two well-known subsystems: a cooling tower and a solar chimney which increases the air flow without the use of electric power. The system is described and presented together with a model for its study. The field data acquired from the prototype built in southern Spain establishes the actual potential of the system, which provides a new approach to a sustainable technological development. 相似文献
3.
The extinction coefficient ? at 2.9 μm for OH in fluoride glasses is measured by determining the amount of HF evolved during heating of the glass under steam and the corresponding intensity of the OH absorption band. This coefficient is respectively equal to 31 litre mole?1 cm?1 for BTYbZ glass (15 BaF2 - 29 ThF4 - 28 YbF3 - 28 ZnF2) and 19.5 litre mole?1 cm?1 for BALLA glass (34 BaF2 - 57 ZrF4 - 4 AlF3 - 5 LaF3). 相似文献
4.
Farzaneh Fayazpour Bart Lucas Roosmarijn E. Vandenbroucke Stefaan Derveaux Jan Tavernier Sam Lievens Joseph Demeester Stefaan C. De Smedt 《Advanced functional materials》2008,18(18):2716-2723
To obtain more biologically relevant data there is a growing interest in the use of living cells for assaying the biological activity of unknown chemical compounds. Density ‘multiplex’ cell‐based assays, where different cell types are mixed in one well and simultaneously investigated upon exposure to a certain compound are beginning to emerge. To be able to identify the cells they should be attached to microscopic carriers that are encoded. This paper investigates how digitally encoded microparticles can be loaded with cells while keeping the digital code in the microcarriers readable. It turns out that coating the surface of the encoded microcarriers with polyelectrolytes using the layer‐by‐layer (LbL) approach provides the microcarriers with a ‘highly functional’ surface. The polyelectrolyte layer allows the growth of the cells, allows the orientation of the cell loaded microcarriers in a magnetic field, and does not hamper the reading of the code. It has further been shown that the cells growing on the polyelectrolyte layer can become transduced by adenoviral particles hosted by the polyelectrolyte layer. It is concluded that the digitally encoded microparticles are promising materials for use in biomedical and pharmaceutical in‐vitro research where cells are used as tools. 相似文献
5.
S. Danto P. Houizot C. Boussard‐Pledel X.‐H. Zhang F. Smektala J. Lucas 《Advanced functional materials》2006,16(14):1847-1852
Conditions of formation of bulk tellurium chalcogenide glasses, containing 70–80 at % Te associated to Ga and Ge are described. The characteristic temperatures are measured: the glass‐transition temperature, Tg, is situated in the range 140–185 °C and the difference Tx – Tg, where Tx is the onset crystallization temperature, is in the range 76–113 °C. Moreover, the optical transmission window is exceptional, ranging from 1.99 μm in the bandgap up to 28 μm in the phonon region. Developed within the framework of requirements for the Darwin mission (a search for and study of extrasolar planets), feasibility of infrared optical fibers formed from these glasses is studied. Drawing experiments are conducted with the glass Ga2‐Ge3Te15, which possesses the maximum Tx – Tg, and a first optical fiber is presented. 相似文献
6.
The differentiation method of model reduction is shown to be equivalent to forming successive ratios of multipoint Taylor polynomial approximation of the numerator and denominator of the transfer function, respectively. This reformulation allows the method to be applied entirely through a Routh-type array structure. Strong links are seen to exist between the method and other stability preserving methods via this Routh-type structure 相似文献
7.
Summary A synthetic approach for the preparation of poly(aryl ether amides) has been developed where the generation of an aryl ether
linkage was the polymer-forming reaction. The amide moiety was found to be sufficiently electron withdrawing to activate halosubstituents,
towards nucleophilic aromatic substitution polymerizations, analogous to conventional activating groups (i.e, sulfone, ketone
etc.). Several new A-B monomers, 4-fluoro-N-(4-hydroxyphenyl)benzamide, 1, and 4-fluoro-N-(3-hydroxyphenyl)benzamide, 2, which contain both an amide-activated fluoro group and a phenol group were prepared and their self polymerization studied.
Compounds 1 and 2 were prepared by the condensation of 4-fluorobenzoyl chloride with either 4-or 3-aminophenol, respectively. The polymerizations
were carried out in an N-methyl-2-pyrrolidone (NMP)/N-cyclohexyl-2-pyrrolidone (CHP) solvent mixture in the presence of potassium
carbonate. Several new high molecular weight poly(aryl ethers) were prepared by this route with Tg's in the 225 °C range. 相似文献
8.
Wax crystallization can cause serious damage to petroleum flow because as the viscosity increases, there is organic deposition in the pipe lines, which causes oil production reduction. Ethylene–vinyl acetate copolymers (EVA) are used as an alternative to prevent such problems. The influence of EVA copolymers on the properties of wax synthetic systems, composed of a solvent mixture and paraffin and petroleum asphalt residue (PAR), was evaluated in this work. The performance of EVA as a wax inhibitor depends on the molecular weight and vinyl acetate content of the copolymer and on the presence of the asphalt fraction. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1337–1348, 2002 相似文献
9.
10.
JR Naranjo B Mellstr?m AM Carrión JJ Lucas NS Foulkes P Sassone-Corsi 《Canadian Metallurgical Quarterly》1997,9(12):2778-2783
Thermal washout curves have been proposed as noninvasive tools for analysing lower airway dimensions and pulmonary blood flow, but how upper airway heat transfer affects these washout curves is unclear. The present study was designed to compare extrathoracic and tracheobronchial contributions to thermal washout curves. Respiratory frequency, air ambient temperature, and body core temperature (tc) were varied in six male subjects before and after immersion in cold (1.1 degrees C) water for up to 2 h under three conditions: 1) control: ambient temperature (tamb) = 25 degrees C, rectal temperature change (delta tre) = 0 degrees C; 2) pre-immersion: tamb = 4 degrees C, delta tre = 0 degrees C; and 3) post-immersion: tamb = 25 degrees C, delta tre = -0.7 degrees C. Both peak expiratory nasal (tpn) and oral (tpo) airstream temperatures were measured. Each subject was tested twice. Expiratory tpo was generally higher than tpn in all conditions. Increasing breathing rates lowered tpn and tpo in the control and cold air environments. Orifice temperatures, which are presumed to reflect upper airway blood temperatures, correlated with both tpn and tpo. Lowering tc had no effect on washout curves during quiet breathing and affected only tpn during rapid breathing. The results suggest that while tracheobronchial conditions may contribute to thermal washout curves, extrathoracic conditions predominate. Strong correlations between orifice temperatures, peak expiratory nasal temperatures and peak expiratory oral temperature demonstrate the dominant role of upper airway heat exchange in determining thermal washout curves. 相似文献