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21.
A technique for generating low sidelobes on one side of the main lobe for a parabolic reflector antenna is presented. The reflector system that generates such an asymmetric sidelobe pattern consists of a central parabola with two sections of offset parabolas situated at the top and bottom of the central parabola. By adjusting the positions and dimensions of the side reflectors, considerable suppression of the first few sidelobes can be obtained. Further, by similar adjustments it is possible to achieve suppression of sidelobes on both sides of the main beam, though this suppression is relatively less. The technique, though explained in detail with reference to a cylindrical geometry, is extended for a paraboloid of revolution. The analysis program utilized for the optimization of the side reflectors is based on physical optics current integration.  相似文献   
22.
It is well known that irradiation of azobenzene polymer films between 490 and 530 nm results in alignment of molecules perpendicular to the polarization of the incident beam. I have recently found that irradiation of amorphous azobenzene polymers with linearly polarized light at wavelengths between 560 and 630 nm, where the absorption is minimal, results in a possible uniaxial hedgehog arrangement of the molecules. Experiments performed with a dye laser, which can be tuned continuously between 560 and 630 nm, are described. Not only azobenzene but also another photosensitive molecule, bacteriorhodopsin, seems to exhibit this behavior.  相似文献   
23.

We theoretically analyze the detection of a cancer cell in the one-dimensional photonic crystal by infiltrating different sample cells in the cavity layer. The defect modes appear in their transmission spectra only if the nanocomposite layers are included on either side of the cavity layer. This analysis is carried out by a dielectric constant and the transmittance peak of the cancer cell is compared with the normal cell. The transmittance peak shifts are analyzed with various filling factors for optimization purposes. Through the shifting spectrum, the sensitivity of cancer cell from the normal cell is obtained from a minimum of 42 nm/RIU to a maximum of 43 nm/RIU.

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24.
25.
The sulfated β‐cyclodextrin (sb‐cd) was prepared from β‐cyclodextrin and the sb‐cd was crosslinked with cotton fabric using ethylenediaminetetraacetic acid (EDTA) as crosslinker. After crosslinking, the synthesized ZnO nanoparticles were padded on this fabric surface. Then, the treated fabrics were dyed with neem extract. The synthesized polymer, crosslinked and nanoparticle‐treated cotton fabrics were characterized using fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), particle sized analyzer, and transmission electron microscopy (TEM) studies. The antibacterial test was done against Staphylococcus aureus and Escherichia coli bacterium. The composite coated with neem dyed cotton fabric has exhibited 71% of dye uptake with 2–3 fastness grade and it has 99% of antibacterial efficiency for S. aureus and 97% for E. coli bacterium. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   
26.
Polyethersulfone (PES)-expanded graphite nanocomposites have been prepared by solution blending route after sonicating expanded graphite in dichloromethane. It has been observed that ultrasonication results in nanosheets formation leading to a low percolation threshold of 3 wt.%. At 5 wt.% filler loading the conductivity is of the order of 10−2 S/cm. Hopping type of charge transport occurs at 3.2 wt.% expanded graphite in PES below which capacitive effects couple. The effective dielectric constant at low frequency increases with filler concentration. Impedance measurement has been carried out to evaluate interfacial capacitance which, for 3.2 wt.% expanded graphite addition in PES, increases to 110 pF from 32 pF for 1 wt.% expanded graphite in the polymer. DSC analysis shows an increment of 12 °C in the Tg of PES with 3 wt.% expanded graphite suggesting interaction between the polymer and filler.  相似文献   
27.
A theoretical study is conducted to examine the peristaltic pumping with double‐diffusive convection in Jeffery nanofluids through a two‐dimensional infinite asymmetric channel. The flow is examined in a wave casing of orientation that moves pace with the velocity of the wave. The peristaltic wave train on the walls that have different amplitude and phase is chosen to form channel irregularity. Rosseland approximation is noticed in the modeling of the transmission radiation heat transfer and temperatures of the walls are recognized constants. The replica has a great impact in discovering nanofluid dynamic influences on peristaltic motion, in biological vessels as symbolized by transportation of heat in blood flow, food molecules, hormones, novel pharmacodynamics pumps, and engineered gastrointestinal motility enhancement. Peristaltic motion has applications in physiology, such as transport of urine, transport of food bolus through gastrointestinal tract, and transport of blood through small blood vessels. Analytical results have been established for stream function, axial velocity, temperature, and absorption and nanoparticle volume fraction. The effect of the principal hydrodynamic parameters (thermophoresis, Brownian motion, Dufour, and Soret) and Grashof numbers (concentration, thermal, nanoparticle) on peristaltic transport patterns with double‐diffusive convection are deliberated with the support of computational outcomes found. The pictorial investigation is done to investigate the possessions of miscellaneous limitations on flow quantities of curiosity.  相似文献   
28.
An industrial solution of ethylenediamine hydrochloride which contains about 18% chloride and 12% amine was electrodialysed in a five‐compartment cell to obtain pure ethylenediamine. Different parameters such as alkali concentration and current density were studied to optimise conditions of maximum current efficiency for amine recovery and chloride removal from the feed solution. The Suitabilities of different ion‐exchange membranes for electrodialysis were compared. Variation in current efficiency for amine recovery with increases in the concentration of amine during electrodialysis was also studied. Current efficiency for amine recovery and chloride removal is about 78% and 91% respectively under optimum conditions. The amount of electrical energy consumed is 12.1 kWh kg?1 for ethylenediamine recovery and 8.6 kWh kg?1 for chloride removal. The concentration of pure amine obtained after the electrodialysis was around 20%. The results are encouraging for industrial applications whereby ethylenediamines free from chlorides can be isolated. Copyright © 2003 Society of Chemical Industry  相似文献   
29.
Advanced Scout: Data Mining and Knowledge Discovery in NBA Data   总被引:1,自引:0,他引:1  
Advanced Scout is a PC-based data mining application used by National Basketball Association (NBA)coaching staffs to discover interesting patterns in basketball game data. We describe Advanced Scout software from the perspective of data mining and knowledge discovery. This paper highlights the pre-processing of raw data that the program performs, describes the data mining aspects of the software and how the interpretation of patterns supports the processof knowledge discovery. The underlying technique of attribute focusing asthe basis of the algorithm is also described. The process of pattern interpretation is facilitated by allowing the user to relate patterns to video tape.  相似文献   
30.
CAD–CAM integration has involved either design with standard manufacturing features (feature-based design), or interpretation of a solid model based on a set of predetermined feature patterns (automatic feature recognition). Thus existing approaches are limited in application to predefined features, and also disregard the dynamic nature of the process and tool availability in the manufacturing shop floor. To overcome this problem, we develop a process oriented approach to design interpretation, and model the shape producing capabilities of the tools into tool classes. We then interpret the part by matching regions of it with the tool classes directly. In addition, there could be more than one way in which a part can be interpreted, and to obtain an optimal plan, it is necessary for an integrated computer aided process planning system to examine these alternatives. We develop a systematic search algorithm to generate the different interpretations, and a heuristic approach to sequence operations (set-ups/tools) for the features of the interpretations generated. The heuristic operation sequencing algorithm considers features and their manufacturing constraints (precedences) simultaneously, to optimally allocate set-ups and tools for the various features. The modules within the design interpretation and process planner are linked through an abstracted qualitative model of feature interactions. Such an abstract representation is convenient for geometric reasoning tasks associated with planning and design interpretation.  相似文献   
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