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51.
Kianoosh Yousefi Reza Saleh Peyman Zahedi 《Journal of Mechanical Science and Technology》2014,28(4):1297-1310
The effects of jet width on blowing and suction flow control were evaluated for a NACA 0012 airfoil. RANS equations were employed in conjunction with a Menter’s shear stress turbulent model. Tangential and perpendicular blowing at the trailing edge and perpendicular suction at the leading edge were applied on the airfoil upper surface. The jet widths were varied from 1.5% to 4% of the chord length, and the jet velocity was 0.3 and 0.5 of the free-stream velocity. Results of this study demonstrated that when the blowing jet width increases, the lift-to-drag ratio rises continuously in tangential blowing and decreases quasi-linearly in perpendicular blowing. The jet widths of 3.5% and 4% of the chord length are the most effective amounts for tangential blowing, and smaller jet widths are more effective for perpendicular blowing. The lift-to-drag ratio improves when the suction jet width increases and reaches its maximum value at 2.5% of the chord length. 相似文献
52.
Kourosh Kabiri Speideh Lashani Mohammad Jalal Zohuriaan-Mehr Malihe Kheirabadi 《Journal of Polymer Research》2011,18(3):449-458
Alcohol-specific superabsorbing gels (super-alcogels) based on non-neutralized acrylic acid (AA, 60–94 mol%) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) were prepared
via solution polymerization in water. Polyethylene glycol dimethacrylate and potassium persulfate were used as crosslinker
and initiator, respectively. Characterization of samples was performed using FTIR, 1H-NMR and thermomechanical analyses. Glass transition temperature and modulus of dried samples were found to be directly changed
with their AA content. The gels exhibited enormous ability for absorbing and retaining a variety of mono- and poly-hydric
alcohols. For example, in lieu of one gram of a typical sample composing 25 mol% AMPS, its absorption capacity was measured
to be 53.0 g methanol, 42.1 g ethanol, 12.1 g n-propanol, 3.4 g iso-propanol, 41.2 g ethylene glycol, 20.7 g propylene glycol, 37.8 g 1,3-propanediol and 32.9 g glycerol. The absorbencies were
superior to those of a known commercial poly(AA) sample, Carbopol. The alcohol absorbency was improved with increase of AMPS
incorporated. It was recognized to be dependant on the alcohol characteristics such as H-bonding ability, OH/C ratio, electronic
features (e.g. dielectric constant), steric hindrance of the neighboring groups of the solvent OH group, as well as the solvent
viscosity. Normal phase transitions were observed in the gel swelling behavior in the alcohol-water binary mixtures. Rheological
measurements of the water-swollen gel showed that more AMPS content resulted in gels with inferior storage modulus. All the
empirical observations were discussed based on the related physicochemical principles. 相似文献
53.
A wavelet-based interpolation-restoration method for superresolution (wavelet superresolution) 总被引:2,自引:0,他引:2
Superresolution produces high-quality, high-resolution images from a set of degraded, low-resolution images where relative frame-to-frame motions provide different looks at the scene. Superresolution translates data temporal bandwith into enhanced spatial resolution. If considered together on a reference grid, given low-resolution data are nonuniformly sampled. However, data from each frame are sampled regularly on a rectangular grid. This special type of nonuniform sampling is called interlaced sampling. We propose a new wavelet-based interpolation-restoration algorithm for superresolution. Our efficient wavelet interpolation technique takes advantage of the regularity and structure inherent in interlaced data, thereby significantly reducing the computational burden. We present one- and two-dimensional superresolution experiments to demonstrate the effectiveness of our algorithm.This work was supported in part by the National Science Foundartion Grant CCR-9984246. 相似文献
54.
55.
Ipakchi Hossein Shegeft Atefeh Rezadoust Amir Masoud Zohuriaan-Mehr Mohammad Jalal Kabiri Kourosh Sajjadi Samahe 《Iranian Polymer Journal》2020,29(4):287-299
Iranian Polymer Journal - Toward sustainability of polymer-matrix composites, this study aimed to prepare and evaluate glass fiber reinforced (GFR) biocomposites of fully bio-based furan resin, and... 相似文献
56.
G Lange-Savage H Berchtold A Liesum KH Budt A Peyman J Knolle J Sedlacek M Fabry R Hilgenfeld 《Canadian Metallurgical Quarterly》1997,248(2):313-322
Catalase is a ubiquitous peroxisomal matrix enzyme, yet the molecular targeting signal(s) for sorting it in plant cells has not been defined. The most common peroxisome targeting signal (PTS) is a C-terminal tripeptide composed of a conserved SKL motif (type 1 PTS). The PTS for cottonseed catalase (Ccat) was elucidated in this study from immunofluorescence microscopic analyses of tobacco BY-2 suspension cells serving as an in vivo import system. To distinguish biolistically introduced Ccat from endogenous tobacco catalase, Ccat was hemagglutinin (HA)epitope-tagged at its N-terminus. Bombardment with HA-Ccat resulted in the import of Ccat into glyoxysomes, the specialized type of peroxisome in BY-2 cells. The C-terminal tripeptide of Ccat, PSI, is necessary for import. Evidence for this were mislocalizations to the cytosol of PSI-truncated Ccat and AGV-substituted (for PSI) Ccat. PSI-COOH, however, was not sufficient to re-route chloramphenicol acetyltransferase (CAT) from the cytosol to glyoxysomes, whereas the Ccat tetrapeptide RPSI-COOH was sufficient. Surprisingly, substitution of K (common at the fourth position in other plant catalases) for the R (CAT-KPSI) decreased import efficiency. However, substitution of K did not affect import, when additional upstream residues in Ccat were included (e.g. CAT-NVKPSI). Other evidence for the importance of upstream residues comprised abolishment of Ccat import due to substitutions with non-conserved residues (e.g. -AGVNVRPSI for -SRLNVRPSI). These data indicate that Ccat is sorted to plant peroxisomes by a degenerate type 1 PTS (PSI-COOH) whose residues are functionally dependent on a strict context of adjacent C-terminal amino acid residues. 相似文献
57.
58.
An integral identity developed by Brenner (1964) is used in the “reversed” context to derive a fixed point iterative scheme for the surface tractions on a rigid particle of arbitrary shape submerged in Stokes flows. The iterative approach facilitates the solution of very large systems of equations and thus the employment of high resolution discretization schemes. The utility of the approach is demonstrated by illustrative computations of the tractions on regular polyhedra, with special emphasis on the results near the edges and corners where (integrable) singular behavior is expected to provide a stringent test for the numerical method. Excellent agreement between our numerical estimates for the exponent of these singularities with the analytical result (local 2-D analysis) were obtained. The emphasis in this work is on validation of the approach, but references to applications, such as fluidic self-assembly of semiconductor microstructures, are provided. 相似文献
59.
60.
Development of a coupled wavelet transform and evolutionary Levenberg‐Marquardt neural networks for hydrological process modeling
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This research aims to present a general framework by which the most appropriate wavelet parameters including mother wavelet, vanishing moment, and decomposition level can be chosen for a joint wavelet transform and machine learning model. This study is organized in 2 parts: the first part presents an evolutionary Levenberg‐Marquardt neural network (ELMNN) model as the most effective machine learning configuration, and the second part describes how the wavelet transform can be effectively embedded with the developed ELMNN model. In this research, the rainfall and runoff time series data of 2 distinct watersheds at 2 different time scales (daily and monthly) were used to build the proposed hybrid wavelet transform and ELMNN model. The conclusions of this study showed that the Daubechies wavelet more than other wavelet families is capable to extract the informative features of hydrologic series. The vanishing moment and decomposition level of this mother wavelet should be selected based on the watershed behavior and the time resolution of rainfall and runoff time series, respectively. The verification results for both watersheds at daily and monthly time scales indicated root mean square error, peak value criterion, low value criterion, and Kling‐Gupta efficiency as about 0.017, 0.021, 0.023, and 0.91, respectively. 相似文献