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991.
992.
Ahmad J Rusumdar A. Abuthalib Vaka Murali Mohan C. Srinivasa Kumar V. Sujatha P. Rajendra Prasad 《Experimental Thermal and Fluid Science》2009,33(5):791-796
The hydrodynamics and energy consumption have been studied in a cold flow, bubbling and turbulent, pressurized gas–liquid–solid three-phase fluidized bed (0.15 m ID × 1 m height) with concurrent gas–liquid up flow is proposed with the intention of increasing the gas hold up. The hydrodynamic behaviour is described and characterised by some specific gas and liquid velocities. Particles are easily fluidized and can be uniformly distributed over the whole height of the column. The effect of parameters like liquid flow rate, gas flow rate, particle loading, particle size, and solid density on gas hold up and effect of gas flow rate, solid density and particle size on solid hold up, energy consumption and minimum fluidization velocity has been studied. At the elevated pressures a superior method for better prediction of minimum fluidization velocity and terminal settling velocities has been adopted. The results have been interpreted with Bernoulli’s theorem and Richardson–Zaki equation. Based on the assumption of the gas and liquid as a pretend fluid, a simplification has been made to predict the particle terminal settling velocities. The Richardson–Zaki parameter n′ was compared with Renzo’s results. A correlation has been proposed with the experimental results for the three-phase fluidization. 相似文献
993.
The phenomenon of slip is known to strongly influence the performance of centrifugal pumps. In the present work, the slip phenomenon at the impeller outlet is studied experimentally for five industrial pumps at different flow rates and the slip factor is estimated for each of these cases. Theoretical slip factors are calculated using several existing methods taking into consideration the main geometric parameters of the impeller. Then the experimental slip factors are compared with the calculated theoretical values.It was observed that in the design-point condition of the pumps, the experimental values are in a good agreement with the theoretical values. However, there are significant disagreements between the theoretical and experimental values at off-design regiments. The difference is more apparent at low flow rates. It is also found that the slip factor depends on the impeller-outlet velocity profile. By defining a flow distortion coefficient, a correlation is derived for evaluating the slip-factor value for off-design conditions.Finally, a slip factor table is provided to calculate the slip factor in centrifugal pumps, using the geometry of impeller. 相似文献
994.
Ahmad Shaabani Abbas Rahmati Elham Farhangi Ali Hossein Rezayan 《Monatshefte für Chemie / Chemical Monthly》2007,35(1):615-618
A novel class of 3,4-dihydrobenzimidazo[2,1-b]quinazolin-1(2H)-ones was synthesized in very short reaction times with good yields in the presence of 3-butyl-1-methyl imidazolium bromide
as a room temperature ionic liquid at 120°C. The ionic liquid can be recycled for subsequent reactions without any loss of
efficiency. 相似文献
995.
JPC – Journal of Planar Chromatography – Modern TLC - Rapid separation of p-hydroxybenzoic acid from methyl p-hydroxy-benzoate, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate,... 相似文献
996.
997.
H. Ahmad M. S. Rahman M. A. J. Miah A. M. I. Ali 《Colloid and polymer science》2001,279(10):1039-1043
A series of poly(methyl methacrylate)/poly(methyl methacrylate-acrylamide) composite polymer particles was prepared with
varying proportions of acrylamide in the copolymer shell layer. Adsorption behaviors of some biomolecules and specific activity
of adsorbed trypsin were studied. The hydrophobic interaction between the composite polymer particle surfaces and biomolecules
decreased with increasing acrylamide content.
Received: 7 February 2001 Accepted: 16 May 2001 相似文献
998.
Mohammad Y. Alshahrani Kholoud M. Alshahrani Munazzah Tasleem Arshiya Akeel Tahani M. Almeleebia Irfan Ahmad Mohammed Asiri Najla A. Alshahrani Nadiyah M. Alabdallah Mohd Saeed 《Molecules (Basel, Switzerland)》2021,26(19)
Minichromosome maintenance complex component 7 (MCM7) is involved in replicative licensing and the synthesis of DNA, and its overexpression is a fascinating biomarker for various cancer types. There is currently no effective agent that can prevent the development of cancer caused by the MCM7 protein. However, on the molecular level, inhibiting MCM7 lowers cancer-related cellular growth. With this purpose, this study screened 452 biogenic compounds extracted from the UEFS Natural Products dataset against MCM protein by using the in silico art of technique. The hit compounds UEFS99, UEFS137, and UEFS428 showed good binding with the MCM7 protein with binding energy values of −9.95, −8.92, and −8.71 kcal/mol, which was comparatively higher than that of the control compound ciprofloxacin (−6.50). The hit (UEFS99) with the minimum binding energy was picked for molecular dynamics (MD) simulation investigation, and it demonstrated stability at 30 ns. Computational prediction of physicochemical property evaluation revealed that these hits are non-toxic and have good drug-likeness features. It is suggested that hit compounds UEFS99, UEFS137, and UEFS428 pave the way for further bench work validation in novel inhibitor development against MCM7 to fight the cancers. 相似文献
999.
Gabriela Schneider-Rauber Mihails Arhangelskis Wei-Pin Goh James Cattle Nicole Hondow Rik Drummond-Brydson Mojtaba Ghadiri Kushal Sinha Raimundo Ho Nandkishor K. Nere Shailendra Bordawekar Ahmad Y. Sheikh William Jones 《Chemical science》2021,12(42):14270
Crystal engineering has advanced the strategies for design and synthesis of organic solids with the main focus being on customising the properties of the materials. Research in this area has a significant impact on large-scale manufacturing, as industrial processes may lead to the deterioration of such properties due to stress-induced transformations and breakage. In this work, we investigate the mechanical properties of structurally related labile multicomponent solids of carbamazepine (CBZ), namely the dihydrate (CBZ·2H2O), a cocrystal of CBZ with 1,4-benzoquinone (2CBZ·BZQ) and the solvates with formamide and 1,4-dioxane (CBZ·FORM and 2CBZ·DIOX, respectively). The effect of factors that are external (e.g. impact stressing) and/or internal (e.g. phase transformations and thermal motion) to the crystals are evaluated. In comparison to the other CBZ multicomponent crystal forms, CBZ·2H2O crystals tolerate less stress and are more susceptible to breakage. It is shown that this poor resistance to fracture may be a consequence of the packing of CBZ molecules and the orientation of the principal molecular axes in the structure relative to the cleavage plane. It is concluded, however, that the CBZ lattice alone is not accountable for the formation of cracks in the crystals of CBZ·2H2O. The strength and the temperature-dependence of electrostatic interactions, such as hydrogen bonds between CBZ and coformer, appear to influence the levels of stress to which the crystals are subjected that lead to fracture. Our findings show that the appropriate selection of coformer in multicomponent crystal forms, targetting superior mechanical properties, needs to account for the intrinsic stress generated by molecular vibrations and not solely by crystal anisotropy. Structural defects within the crystal lattice, although highly influenced by the crystallisation conditions and which are especially difficult to control in organic solids, may also affect breakage.Crystal engineering has advanced the strategies of design and synthesis of organic solids with the main focus being on customising the properties of the materials. 相似文献
1000.