排序方式: 共有19条查询结果,搜索用时 171 毫秒
1.
Kevin P. Nolan Akshat Agarwal Shenghui Lei Robin Shields 《Microfluidics and nanofluidics》2016,20(7):101
Detailed measurements of the flow instability of dilute shear-thinning viscoelastic aqueous solutions, with relatively low zero-shear viscosities, in an obstructed microchannel flow are reported. We examine the flow behaviour resulting from a 100 μm post placed in the channel centreline over a range of Reynolds numbers (\(5<Re<300\)) and Weissenberg numbers (\(20<Wi<10^3\)). Micro-particle image velocimetry measurements show the onset of an upstream instability within a Reynolds number range and at a critical elasticity number corresponding to polymer concentrations above 25 ppm of long-chain polyacrylamide. The instability results in significant local fluctuations in the flow field approaching 30 % of the mean velocity. The magnitude of the local viscosity ratio in the region upstream of the post is proposed as a driving mechanism for the instability which resembles a buckling flow. Additionally, the classical instability owing to separation and vortex formation downstream of the post in Newtonian flow is suppressed and a very long stable wake is observed extending over 10 post-diameters downstream. 相似文献
2.
Jain Deepak Kumar Kumar Akshi Shrivastava Akshat 《Neural computing & applications》2022,34(18):15129-15140
Neural Computing and Applications - The unrelenting trend of doctored narratives, content spamming, fake news and rumour dissemination on social media can lead to grave consequences that range from... 相似文献
3.
Steven Le Moan Tejas Madan Tanksale Roman Byshko Philipp Urban 《Journal of the Society for Information Display》2017,25(9):554-560
The effect of observer metamerism induced by electronic displays depends to a large extent on their primary spectra (red, green, and blue in the most common case). In particular, for narrow‐band primary spectra whose peak wavelength lies in the range of high variability of the observer's color‐matching function, some observers can experience very large differences between actual surface colors (e.g. in a light booth) and displayed colors if the monitor is optimized for the International Commission on Illumination (CIE) 1931 standard observer. However, because narrow‐band light‐emitting diodes lead to larger color gamuts, more and more monitors with very narrow band primaries are coming onto the market without manufacturers taking into account the associated problem of observer variations. Being able to measure these variations accurately and efficiently is therefore an important objective. In this paper, we propose a new approach to predict the extent of observer metamerism for a particular multiprimary display. Unlike existing dedicated models, ours does not depend on a reference illuminant and a set of reflectance spectra and is computationally more efficient. 相似文献
4.
A new calorimeter to measure specific heat of indigenously prepared granular activated carbon (AC) for application in a refrigeration system based on gas adsorption–desorption mechanism is presented. This calorimeter allows specific heat measurements in high (305.5–317.8 K) as well as low (254.6–264 K) temperature ranges. The specific heat of prepared AC on measurement using developed calorimeter has been found to be 1.062 J g?1 K?1. Preparation, instrumental analyses and influence of various physical properties of AC on its specific heat have also been discussed. Characterisation results of AC demonstrate that it can be efficiently used in such cold producing system down to refrigeration and cryogenic temperature. © 2012 Canadian Society for Chemical Engineering 相似文献
5.
Khatri Deepti Goyal Rahul Darad Akarsh Jain Akshat Rawat Samar Khan Alif Johnson Alan T. 《Clean Technologies and Environmental Policy》2019,21(7):1485-1498
Clean Technologies and Environmental Policy - The continual hike in environmental pollution from diesel engines has raised the concern of researchers to identify certain clean fuels. For this... 相似文献
6.
Muxina Konarova Akshat Tanksale Jorge Norberto Beltramini Gao Qing Lu 《International Journal of Hydrogen Energy》2012
A porous MgH2/C composite can be synthesized through decomposition of an organo-magnesium precursor under hydrogen pressure. XRD patterns of the porous MgH2/C composite exhibit a pure MgH2 phase with a tetragonal structure. The morphology of the resulted samples is significantly dependent on the synthesis temperature and hydrogen pressure. The samples exhibit a rod-like structure and composed of nano-crystallites of MgH2 with a size of less than 5 nm. TPD spectra of a sample synthesized at 220 °C for 4 h show a remarkable decrease of the onset hydrogen release temperature. Further, this sample also exhibits fast hydrogen adsorption kinetics adsorbing 6 wt % of hydrogen in 3 min at 250 °C. The same amount of hydrogen is adsorbed in 11 min at 200 °C and 40 min at 150 °C, respectively. N2 physisorption measurements of this sample indicate meso-porosity with a BET surface area of 40.9 m2 g−1 and an average pore diameter of 20 nm. 相似文献
7.
Multiple memory models have been proposed to capture the effects of memory hierarchy culminating in the I-O model of Aggarwal
and Vitter (Commun. ACM 31(9):1116–1127, [1988]). More than a decade of architectural advancements have led to new features that are not captured in the I-O model—most
notably the prefetching capability. We propose a relatively simple Prefetch model that incorporates data prefetching in the traditional I-O models and show how to design optimal algorithms that
can attain close to peak memory bandwidth. Unlike (the inverse of) memory latency, the memory bandwidth is much closer to
the processing speed, thereby, intelligent use of prefetching can considerably mitigate the I-O bottleneck. For some fundamental
problems, our algorithms attain running times approaching that of the idealized random access machines under reasonable assumptions.
Our work also explains more precisely the significantly superior performance of the I-O efficient algorithms in systems that
support prefetching compared to ones that do not.
相似文献
Sandeep SenEmail: |
8.
Molecular and biotechnological aspects of microbial proteases 总被引:1,自引:0,他引:1
Proteases represent the class of enzymes which occupy a pivotal position with respect to their physiological roles as well as their commercial applications. They perform both degradative and synthetic functions. Since they are physiologically necessary for living organisms, proteases occur ubiquitously in a wide diversity of sources such as plants, animals, and microorganisms. Microbes are an attractive source of proteases owing to the limited space required for their cultivation and their ready susceptibility to genetic manipulation. Proteases are divided into exo- and endopeptidases based on their action at or away from the termini, respectively. They are also classified as serine proteases, aspartic proteases, cysteine proteases, and metalloproteases depending on the nature of the functional group at the active site. Proteases play a critical role in many physiological and pathophysiological processes. Based on their classification, four different types of catalytic mechanisms are operative. Proteases find extensive applications in the food and dairy industries. Alkaline proteases hold a great potential for application in the detergent and leather industries due to the increasing trend to develop environmentally friendly technologies. There is a renaissance of interest in using proteolytic enzymes as targets for developing therapeutic agents. Protease genes from several bacteria, fungi, and viruses have been cloned and sequenced with the prime aims of (i) overproduction of the enzyme by gene amplification, (ii) delineation of the role of the enzyme in pathogenecity, and (iii) alteration in enzyme properties to suit its commercial application. Protein engineering techniques have been exploited to obtain proteases which show unique specificity and/or enhanced stability at high temperature or pH or in the presence of detergents and to understand the structure-function relationships of the enzyme. Protein sequences of acidic, alkaline, and neutral proteases from diverse origins have been analyzed with the aim of studying their evolutionary relationships. Despite the extensive research on several aspects of proteases, there is a paucity of knowledge about the roles that govern the diverse specificity of these enzymes. Deciphering these secrets would enable us to exploit proteases for their applications in biotechnology. 相似文献
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10.
Hussam Mahmoud Akshat Chulahwat 《Computer-Aided Civil and Infrastructure Engineering》2018,33(5):353-372
Mitigating the impact of disasters on communities requires not only a deep understanding of the essential features of infrastructure, social, and economical components that make a community resilient; but also the development of mathematical models that can seamlessly integrate these features. This article lays the foundation for an integrative model that captures interaction between these components. The underlying fundamentals of the proposed model hinges on the principle of a damped harmonic oscillator by assuming the behavior of a community in response to a hazard is equivalent to the response of a vibrating mass of finite stiffness and damping. We implemented the dynamic model by developing a novel finite element formulation capable of quantifying resilience both temporally and spatially. We then used the developed model to devise a suitable hazard‐agnostic definition of community resilience. This was realized through a set of demonstration and logical verification tests conducted on Gotham City, the fictional city of the infamous character, Batman. It was observed that the model can be used to identify sensitive and vulnerable areas in a community, provide a spatial and temporal quantification of community resilience, and accommodate various types of hazards such as physical disruptions, economic downtimes, and even social disorders. 相似文献