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161.
This short note reports the results concerning electron paramagnetic resonance (EPR) and optical absorption spectra of Cu2+ ions doped in sodium potassium sulphate both at 300K and 77K. 相似文献
162.
Using the basic equations of heat conducting micropolar fluid, heat transfer through a channel of porous walls has been studied. The temperature distribution is obtained for different values of suction parameter , convective parameter and micropolar parameter . 相似文献
163.
Albuquerque Gabriela B. M. L. Silva Valdir P. Rodrigues Joo Paulo C. 《Fire Technology》2022,58(2):737-775
Fire Technology - Reinforced concrete beams lose resistance at high temperatures and so as to guarantee their good performance, it is mandatory to consider this accidental action in design. As an... 相似文献
164.
165.
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
166.
Bhari Mallanna Nagaraja Aytam Hari PadmasriBurri David Raju Kamaraju Seetha Rama Rao 《International Journal of Hydrogen Energy》2011,36(5):3417-3425
Cu-MgO is found to be an efficient catalyst for the coupling reaction of furfural (FAL) hydrogenation and cyclohexanol (CyOH) dehydrogenation. This process is not only efficient in compensating the thermodynamic equilibrium constraints in the cyclohexanol dehydrogenation and improving the yields towards cyclohexanone but also is a economical route for the synthesis of furfuryl alcohol (FFA) and cyclohexanone (Cyone) as the process do not need any external pumping of hydrogen. The effect of incorporation of various promoters viz., Co, Zn, Fe, Cr, Pd and Ni in Cu-MgO over its activity towards this coupling reaction has been studied. Incorporation of Cr in Cu-MgO catalyst is found be an advantageous in enhancing the yields of both FFA and Cyone. All other promoters though found to show higher activity for the individual reactions of FAL hydrogenation and CyOH dehydrogenation, failed to do the same in their coupling reaction. The stabilization of active species (Cu+/Cu0) by Cr which also seem to increase the synergetic interaction between Cu and MgO as observed from higher dispersion of copper (from XRD results) and easier reducibility of copper oxide (from TPR results) seem to be the factors behind its higher activity over other promoted catalysts. 相似文献
167.
Mihaela Homocianu Diana Serbezeanu Gabriela Lisa Mihai Brebu Tchi Vlad-Bubulac 《International journal of molecular sciences》2022,23(21)
Among the multitude of polymers with carbon-based macromolecular architectures that easily ignite in certain applications where short circuits may occur, polyimide has evolved as a class of polymers with high thermal stability while exhibiting intrinsic flame retardancy at elevated temperatures via a char-forming mechanism. However, high amounts of aromatic rings in the macromolecular backbone are required for these results, which may affect other properties such as film-forming capacity or mechanical properties; thus, much work has been done to structurally derivatize or make hybrid polyimide systems. In this respect, flexible polyimide films (PI(1–4)) containing bulky 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) units have been developed starting from commercial dianhydrides and an aromatic diamine containing two side chain bulky DOPO groups. The chemical structure of PI(1–4)) was characterized by 1H NMR, 13C NMR and 31P NMR spectroscopy. The optical properties, including absorption and luminescence spectra of these polymers, were analyzed. All polyimides containing DOPO derivatives emitted blue light with an emission maxima in the range of 340–445 nm, in solvents such as N,N-dimethylformamide, N-methyl-2-pyrrolidone, chloroform, and N,N-dimethylacetamide, while green light emission (λem = 487 nm for PI-4) was evidenced in a thin-film state. The thermal decomposition mechanism and flame-retardant behavior of the resulting materials were investigated by pyrolysis-gas-chromatography spectrometry (Py-GC), scanning electron microscopy (SEM), EDX maps and FTIR spectroscopy. The residues resulting from the TGA experiments were examined by SEM microscopy images and FTIR spectra to understand the pyrolysis mechanism. 相似文献
168.
Melo Karla R. B. Grace John R. Lopes Gabriela C. 《Clean Technologies and Environmental Policy》2022,24(2):623-632
Clean Technologies and Environmental Policy - Fluidized bed bioreactors are widely used in wastewater treatment applications. Such reactors employ gel beads or hard particles covered with a biofilm... 相似文献
169.
Kandukuri Rama Krishna Achterhold Jan Moeller Michael Stueckler Joerg 《International Journal of Computer Vision》2022,130(1):3-16
International Journal of Computer Vision - Representation learning for video is increasingly gaining attention in the field of computer vision. For instance, video prediction models enable activity... 相似文献