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排序方式: 共有305条查询结果,搜索用时 62 毫秒
1.
P. Sampath Brijesh Kakarla Raghava Reddy C. Venkata Reddy Nagaraj P. Shetti Raghavendra V. Kulkarni Anjanapura V. Raghu 《化学工程与技术》2020,43(7):1240-1248
Hydrogen fuel is a promising alternative to fossil fuels because of its energy content, clean nature, and fuel efficiency. However, it is not readily available. Most current producion processes are very energy intensive and emit carbon dioxide. Therefore, this article reviews technological options for hydrogen production that are eco-friendly and generate clean hydrogen fuel. Biological methods, such different fermentation processes and photolysis are discussed together with the required substrates and the process efficiency. 相似文献
2.
Joint halftoning and watermarking 总被引:2,自引:0,他引:2
A framework to jointly halftone and watermark a grayscale images is presented. The framework needs the definition of three components: a human visual system (HVS)-based error metric between the continuous-tone image and a halftone, a watermarking scheme with a corresponding watermark detection measure, and a search strategy to traverse the space of halftones. We employ the HVS-based error metric used in the direct binary search (DBS) halftoning algorithm, and we use a block-based spread spectrum watermarking scheme and the toggle and swap search strategy of DBS. The halftone is printed on a desktop printer and scanned using a flatbed scanner. The watermark is detected from the scanned image and a number of post-processed versions of the scanned image, including one restored in Adobe PhotoShop. The results show that the watermark is extremely resilient to printing, scanning, and post-processing; for a given baseline image quality, joint optimization is better than watermarking and halftoning independently. For this particular algorithm, the original continuous-tone image is required to detect the watermark. 相似文献
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Mosaliganti K Cooper L Sharp R Machiraju R Leone G Huang K Saltz J 《IEEE transactions on visualization and computer graphics》2008,14(4):863-876
Developments in optical microscopy imaging have generated large high-resolution data sets that have spurred medical researchers to conduct investigations into mechanisms of disease, including cancer at cellular and subcellular levels. The work reported here demonstrates that a suitable methodology can be conceived that isolates modality-dependent effects from the larger segmentation task and that 3D reconstructions can be cognizant of shapes as evident in the available 2D planar images. In the current realization, a method based on active geodesic contours is first deployed to counter the ambiguity that exists in separating overlapping cells on the image plane. Later, another segmentation effort based on a variant of Voronoi tessellations improves the delineation of the cell boundaries using a Bayesian formulation. In the next stage, the cells are interpolated across the third dimension thereby mitigating the poor structural correlation that exists in that dimension. We deploy our methods on three separate data sets obtained from light, confocal, and phase-contrast microscopy and validate the results appropriately. 相似文献
6.
Harnessing power from sea water using nano material as photocatalyst and solar energy as light source: the role of hydrocarbon as dual agent 下载免费PDF全文
D. DeepanPrakash V. Premnath C. Raghu S. Vishnukumar S.S. Jayanthi D. Easwaramoorthy 《国际能源研究杂志》2014,38(2):249-253
The splitting of water in the presence of ordinary and nano TiO2 was carried out using hydrocarbon as a dual agent and solar energy as a light source for these experiments. The hydrogen gas evolved was tested and measured using downward displacement of water. The observed results show that more hydrogen was evolved when nano TiO2 was used as catalyst due to the larger surface area of the nano material. The splitting of sea water yields more hydrogen compared with ordinary water due to the presence of electron donating sodium ions in water. The added hydrocarbon plays a dual role as electron donor and as a trapping agent, which enhances the production of hydrogen to a greater extent compared with the regular donors such as olefin. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
7.
Structural parts used in boilers, turbines, ships, and many household purposes are manufactured through sheet metal forming processes. During manufacturing, the micro structure of the material is deformed and micro cracks along with anisotropic properties get induced. Present research deals with a thin sheet metal plate containing a central crack subjected to mixed mode (I+II) loading. With special reference to Lankford's coefficient and degree of anisotropy, the effect of anisotropic triaxiality on crack initiation angle has been investigated. The result reveals the combinations of Lankford's coefficient and degree of anisotropy for which crack initiation angle do not change. 相似文献
8.
R. Vidya Sagar B. K. Raghu Prasad B. L. Karihaloo 《International Journal of Fracture》2010,161(2):121-129
Notched three-point bend specimens (TPB) were tested under crack mouth opening displacement (CMOD) control at a rate of 0.0004 mm/s
and the entire fracture process was simulated using a regular triangular two-dimensional lattice network only over the expected
fracture process zone width. The rest of the beam specimen was discretised by a coarse triangular finite element mesh. The
discrete grain structure of the concrete was generated assuming the grains to be spherical. The load versus CMOD plots thus
simulated agreed reasonably well with the experimental results. Moreover, acoustic emission (AE) hits were recorded during
the test and compared with the number of fractured lattice elements. It was found that the cumulative AE hits correlated well
with the cumulative fractured lattice elements at all load levels thus providing a useful means for predicting when the micro-cracks
form during the fracturing process, both in the pre-peak and in the post-peak regimes. 相似文献
9.
Adipokines are a growing group of peptide or protein hormones that play important roles in whole body metabolism and metabolic diseases. Sleep is an integral component of energy metabolism, and sleep disturbance has been implicated in a wide range of metabolic disorders. Accumulating evidence suggests that adipokines may play a role in mediating the close association between sleep disorders and systemic metabolic derangements. In this review, we briefly summarize a group of selected adipokines and their identified function in metabolism. Moreover, we provide a balanced overview of these adipokines and their roles in sleep physiology and sleep disorders from recent human and animal studies. These studies collectively demonstrate that the functions of adipokine in sleep physiology and disorders could be largely twofold: (1) adipokines have multifaceted roles in sleep physiology and sleep disorders, and (2) sleep disturbance can in turn affect adipokine functions that likely contribute to systemic metabolic derangements. 相似文献
10.
Preparation and characterization of novel polyurethanes containing 4,4′‐{oxy‐1,4‐diphenyl bis(nitromethylidine)}diphenol schiff base diol 下载免费PDF全文
Four novel segmented polyurethanes (PUs) based on4,4′‐{oxy‐1,4‐diphenyl bis(nitromethylidine)}diphenol (ODBNMD) diol with different diisocyanates such as 4,4′‐diphenylmethane diisocyanate, toluene 2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate have been prepared by solution method. The structures of ODBNMD and PUs have been confirmed by Fourier transform infrared (FTIR), nuclear magnetic resonance (1H‐NMR and 13C‐NMR), UV‐visible, and fluorescence spectroscopies. The segmented PUs were further characterized by thermogravimetry (TGA), differential scanning calorimetry (DSC), and wide‐angle X‐ray diffraction. FTIR confirmed hydrogen bonding interactions, whereas TGA and DSC suggested that introduction of aromatic/phenyl ring in the main chain considerably increased the thermal stability. POLYM. ENG. SCI., 54:24–32, 2014. © 2013 Society of Plastics Engineers 相似文献