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81.
In this article we have studied the peristaltic motion of an incompressible Williamson fluid with constant and radially varying magnetohydrodynamics (MHD) in an endoscope. Using the low Reynolds and long wavelength assumptions, the equations of Williamson fluid model in simplified form are solved using (i) the HAM method and (ii) the Shooting method. The comparisons of both solutions have been found a very good agreement. Graphical results have been presented for various emerging parameters. © British Crown Copyright 2010/MOD. Reproduced with permission. Published by John Wiley & Sons, Ltd. 相似文献
82.
Multimode generalization of Schrödinger cat states of light is discussed. Two-mode Schrödinger cat states are considered as an example. Squeezing in even and odd coherent states of a two-mode field is studied. 相似文献
83.
Umar Asghar Mehvish Iram Zile Huma Rubina Nelofer Muhammad Nadeem 《Natural product research》2015,29(2):125-131
This study was conducted to analyse structural changes through scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) after alkaline pretreatment of wheat straw for optimum steaming period. During the study, 2 mm size of substrate was soaked in 2.5% NaOH for 1 h at room temperature and then autoclaved at 121°C for various steaming time (30, 60, 90 and 120 min). Results revealed that residence time of 90 min at 121°C has strong effect on substrate, achieving a maximum cellulose content of 83%, delignification of 81% and hemicellulose content of 10.5%. Further SEM and FTIR spectroscopy confirmed structural modification caused by alkaline pretreatment in substrate. Maximum saccharification yield of 52.93% was achieved with 0.5% enzyme concentration using 2.5% substrate concentration for 8 h of incubation at 50°C. This result indicates that the above-mentioned pretreatment conditions create accessible areas for enzymatic hydrolysis. 相似文献
84.
Mehwish Iqtedar Mohammad Nadeem Hira Naeem Roheena Abdullah Shagufta Naz Qurat ul Ain Syed 《Natural product research》2015,29(11):1012-1019
The industrialisation of lignocellulose conversion is impeded by expensive cellulase enzymes required for saccharification in bioethanol production. Current research undertakes cellulase production from pretreated Saccharum spontaneum through Trichoderma viride HN1 under submerged fermentation conditions. Pretreatment of substrate with 2% NaOH resulted in 88% delignification. Maximum cellulase production (2603 ± 16.39 U/mL/min carboxymethyl cellulase and 1393 ± 25.55 U/mL/min FPase) was achieved at 6% substrate at pH 5.0, with 5% inoculum, incubated at 35°C for 120 h of fermentation period. Addition of surfactant, Tween 80 and metal ion Mn+2, significantly enhanced cellulase yield. This study accounts proficient cellulase yield through process optimisation by exploiting cheaper substrate to escalate their commercial endeavour. 相似文献
85.
86.
Castillo-Martínez E Bieringer M Shafi SP Cranswick LM Alario-Franco MÁ 《Journal of the American Chemical Society》2011,133(22):8552-8563
A novel ScVO(3) perovskite phase has been synthesized at 8 GPa and 1073 K from the cation-disordered bixbyite-type ScVO(3). The new perovskite has orthorhombic symmetry at room temperature, space group Pnma, and lattice parameters a = 5.4006(2) ?, b = 7.5011(2) ?, and c = 5.0706(1) ? with Sc(3+) and V(3+) ions fully ordered on the A and B sites of the perovskite cell. The vanadium oxygen octahedra [V-O(6)] display cooperative Jahn-Teller (JT) type distortions, with predominance of the tetragonal Q(3) over the orthorhombic Q(2) JT modes. The orthorhombic perovskite shows Arrhenius-type electrical conductivity and undergoes a transition to triclinic symmetry space group P-1 close to 90 K. Below 60 K, the magnetic moments of the 4 nonequivalent vanadium ions undergo magnetic long-range ordering, resulting in a magnetic superstructure of the perovskite cell with propagation vector (0.5, 0, 0.5). The magnetic moments are confined to the xz plane and establish a close to zigzag antiferromagnetic mode. 相似文献
87.
A series of 1,3,5-triaryl-2-pyrazolines was synthesized by dissolving the corresponding 4-alkoxychalcones in glacial acetic acid containing a few drops of concentrated hydrochloric acid. This step was followed by the addition of (3,4-dimethylphenyl) hydrazaine hydrochloride. Finally the target compounds were precipitated by pouring the reaction mixture onto crushed ice. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The 1,3,5-triaryl-2-pyrazolines bearing homologous alkoxy groups were found to possess fluorescence properties in the blue region of the visible spectrum when irradiated with ultraviolet radiation. The fluorescent behavior of these compounds was studied by UV-Vis and emission spectroscopy, performed at room temperature. 相似文献
88.
Shahid Hussain Arshad Muhammad Nawaz Naeem Nazra Sultana Zafar Iqbal Abdul Ghafar Shah 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(8):999-1016
In the present work, vibration characteristics of thin functionally graded cylindrical shells are studied under the influence
of various boundary conditions. Fabrication of FGM cylindrical shell is carried out by using exponential volume fraction law.
Strain- and curvature-displacements relationships are taken from Love’s thin shell theory. The frequency equation in the form
of eigenvalue problem is obtained by adapting the Rayleigh-Ritz method. Characteristic beam functions are assumed to approximate
the axial modal dependence. Effects of exponential volume fraction law on the natural frequencies of the FGM cylindrical shells
for various boundary conditions are studied against circumferential wave number, length to radius ratio and thickness to radius
ratio for different values of power law exponents. Results evaluated show good agreement with those available in the literature. 相似文献
89.
In the present investigation we have analyzed the boundary layer flow of a Jeffrey fluid over an exponentially stretching
surface. The effects of thermal radiation are carried out for two cases of heat transfer analysis known as (1) Prescribed
exponential order surface temperature (PEST) and (2) Prescribed exponential order heat flux (PEHF). The highly nonlinear coupled
partial differential equations of Jeffrey fluid flow along with the energy equation are simplified by using similarity transformation
techniques based on boundary layer assumptions. The reduced similarity equations are then solved analytically by the homotopy
analysis method (HAM). The convergence of the HAM series solution is obtained by plotting (h/2p)\hbar-curves for velocity and temperature. The effects of physical parameters on the velocity and temperature profiles are examined
by plotting graphs. 相似文献
90.
Rafiq Shahid Abbas Zaheer Nawaz Muhammad Alharbi Sayer Obaid 《Journal of Thermal Analysis and Calorimetry》2021,145(6):3269-3279
Journal of Thermal Analysis and Calorimetry - A numerical model is developed to study the effects of temperature-dependent viscosity on heat transfer in magnetohydrodynamic flow of micropolar fluid... 相似文献