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151.
Rama Subba Reddy Gorla 《Applied Thermal Engineering》2010,30(17-18):2763-2769
Liquefied Natural Gas transport and storage has become very important due to its ability to occupy 1/600th of the volume that compressed natural gas would occupy at room temperature and atmospheric pressure. In the present work, an LNG storage tank has been computationally simulated and probabilistically evaluated in view of the several uncertainties in the fluid, structural, material and thermal variables that govern the LNG storage tank. A finite element code ALGOR was used to couple the thermal profiles with structural design. The stresses and their variations were evaluated at critical points on the storage tank. Cumulative distribution functions and sensitivity factors were computed for stress responses due to fluid, mechanical and thermal random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design and make it cost effective. The total heat gained by the liquid part in the tank has been evaluated and the amount of boil-off was calculated. Various methods have been proposed to minimize thermal stresses. 相似文献
152.
Romero-Canyas Rainer; Downey Geraldine; Reddy Kavita S.; Rodriguez Sylvia; Cavanaugh Timothy J.; Pelayo Rosemary 《Canadian Metallurgical Quarterly》2010,99(5):802
Societies and social scientists have long held the belief that exclusion induces ingratiation and conformity, an idea in contradiction to robust empirical evidence linking rejection with hostility and aggression. The classic literatures on ingratiation and conformity help resolve this contradiction by identifying circumstances under which rejection may trigger efforts to ingratiate. Jointly, findings from these literatures suggest that when people are given an opportunity to impress their rejecters, ingratiation is likely after rejection experiences that are harsh and that occur in important situations that threaten the individual's self-definition. Four studies tested the hypothesis that people high in rejection sensitivity and therefore dispositionally concerned about rejection will utilize opportunities to ingratiate after harsh rejection in situations that are self-defining. In 3 studies of situations that are particularly self-defining for men, rejection predicted ingratiation among men (but not women) who were high in rejection sensitivity. In a 4th study, harsh rejection in a situation particularly self-defining for women predicted ingratiation among highly rejection-sensitive women (but not men). These findings help identify the specific circumstances under which people are willing to act in socially desirable ways toward those who have rejected them harshly. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
153.
Catalytic packed bed non‐thermal plasma reactor for the extraction of hydrogen from hydrogen sulfide
The decomposition of hydrogen sulfide (H2S) to hydrogen and sulfur with Al2O3, MoOx/Al2O3, CoOx/Al2O3 and NiO/Al2O3 packed non‐thermal plasma dielectric barrier discharge reactor was studied. The reaction was carried out with 5‐mm discharge gap during the decomposition of 5 vol.% H2S at 150 ml/min (STP) flow rate. Typical results indicated the conversion of ~50% at a specific input energy of ~0.92 kJ/l H2S and 10% (in length) packed reactor showed the best conversion. Among the catalysts studied, MoOx and CoOx supported on Al2O3 showed high performance, which may be caused by synergy between plasma excitation of the carrier gas molecules and catalytic behaviour of MoOx and CoOx. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
154.
A series of low‐density polyethylene (LDPE) blends with varying proportions of plasticized tapioca starch have been used for the study of their mechanical properties. A functionalized epoxy resin, namely, poly(ethylene‐co‐glycidyl methacrylate) has been used as the compatibilizer. The impact and tensile properties have been measured by standard ASTM methods. The mechanical properties are seen to improve significantly with the addition of the epoxy compatibilizer, approaching values close to those of virgin LDPE. The scanning electron micrographs of the compatibilized blends show ductile failure which evidently contribute to improved mechanical properties. © 2001 Society of Chemical Industry 相似文献
155.
Traffic sensing and characterization is an important building block of cognitive networking systems, however, it is very challenging to perform traffic characterization in multi-channel multi-radio wireless networks. Due to the presence of network traffic in multiple channels, the existing count-based packet sampling methods demand continuous capture on each channel to be effective; this requires a dedicated wireless interface per channel, and hence the existing sampling methods require a very expensive infrastructure and have poor scalability. Time-based sampling methods, on the other hand, offer a cost-effective and scalable solution by reducing the amount and cost of the resources necessary to monitor and characterize the wireless spectrum.The contributions of this paper include the following: (i) a discussion of packet sampling techniques for traffic sensing in multi-channel wireless networks, (ii) a comparison of various time-based sampling strategies using the Kullback–Leibler divergence (KLD) measure, (iii) a study on the effect of the sampling parameters on the accuracy of the sampling strategies, (iv) development of sampling accuracy graphs for easing the process of best sampling scheme selection in multi-channel wireless networks, (v) the proposal of a new metric (traffic intensity) which estimates the busyness of channels by taking into consideration not only the successfully received packets but also corrupt or broken packets, (vi) implementation of time-based sampling in a prototype traffic sensor device for multi-channel traffic sensing in IEEE 802.11 b/g networks, and (vii) characterization of a campus IEEE 802.11 network environment in a spatio-temporal–spectral fashion using sampled traffic traces collected by traffic sensors. 相似文献
156.
Employing the single beam Z-scan technique with nanosecond laser pulses at 532 nm, the refractive and absorptive nonlinearities of donor and acceptor substituted (2E)-1-(3,4-dimethoxyphenyl)-3-phenylprop-2-en-1-one have been studied. The sign of the nonlinear index of refraction (n 2) is found to be negative and the magnitude of n 2 is in the order of 10?11 esu. The second-order molecular hyperpolarizability (γh) is calculated to be in the order of 10?32 esu. The variation of nonlinear absorption coefficient (βeff) with input intensity (I 0) is studied and the nonlinear absorption mechanism is found to be reverse saturable absorption (RSA). The enhancement of nonlinearity due to the donor and acceptor substitution is in accordance with the variation in π electron delocalization in the molecules. The compounds exhibit good optical limiting as well. 相似文献
157.
Naveen Reddy Kadasala Lu Lin Christopher Gilpin 《Science and Technology of Advanced Materials》2013,14(1):210-218
AbstractAu–FexOy composite nanoparticles (NPs) are of great technological interest due to their combined optical and magnetic properties. However, typical syntheses are neither simple nor ecologically friendly, creating a challenging situation for process scale-up. Here we describe conditions for preparing Au–FexOy NPs in aqueous solutions and at ambient temperatures, without resorting to solvents or amphiphilic surfactants with poor sustainability profiles. These magnetic gold nanoclusters (MGNCs) are prepared in practical yields with average sizes slightly below 100 nm, and surface plasmon resonances that extend to near-infrared wavelengths, and sufficient magnetic moment (up to 6 emu g–1) to permit collection within minutes by handheld magnets. The MGNCs also produce significant photoluminescence when excited at 488 nm. Energy dispersive X-ray (EDX) analysis indicates a relatively even distribution of Fe within the MGNCs, as opposed to a central magnetic core. 相似文献
158.
159.
This paper presents fractal finite element based continuum shape sensitivity analysis for a multiple crack system in a homogeneous, isotropic, and two dimensional linear-elastic body subjected to mixed-mode (modes I and II) loading conditions. The salient feature of this method is that the stress intensity factors and their derivatives for the multiple crack system can be obtained efficiently since it only requires an evaluation of the same set of fractal finite element matrix equations with a different fictitious load. Three numerical examples are presented to calculate the first-order derivative of the stress intensity factors or energy release rates. 相似文献
160.
This paper presents a study on the durability of different types of stabilised and unstabilised rammed earth walls. These rammed earth walls were constructed and exposed for 20 years to natural weathering, in a wet continental climate. None of these walls have shown complete collapse to date. A method to measure the rammed earth walls erosion by stereo-photogrammetry has been developed. The result shows that the mean erosion depth of the studied walls is about 2 mm (0.5% wall thickness) in the case of rammed earth wall stabilised with 5% by dry weight of hydraulic lime and about 6.4 mm (1.6% wall thickness) in the case of unstabilised rammed earth walls. The stabilisation enables to not use any plaster to protect the walls. In the case of the unstabilised rammed earth walls, an extrapolated lifetime longer than 60 years can be assessed. This shows a potential for the use of unstabilised rammed earth in the similar climatic conditions with this study. The method of stereo-photogrammetry used to measure the erosion of rammed earth walls on site may also help to calibrate and develop more pertinent laboratory test to assess the durability of rammed earth wall. 相似文献