Impact of Hall and Ion effects on MHD couple stress nanofluid flow through an inclined channel subjected to convective,hydraulic slip,heat generation,and thermal radiation

This project mainly concentrates on the numerical investigation of the Hall and Ion impact on couple stress nanofluid flow through an inclined microchannel considering the hydraulic slip and convective boundary conditions in the presence of radiative heat flux. The analysis has been made via assuming that the fluid is incompressible, electrically conducting, and viscous. The parameters of couple stress, convection, and heat generation have been employed. Different water‐based nanofluids containing $\text{Cu}\mathrm{,}\text{Ag}\mathrm{,}\text{Cuo}\mathrm{,}\text{Mo}{\mathrm{S}}_2\mathrm{,}\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3$, and $\text{Ti}{\mathrm{O}}_2$ are taken into account. To reduce the nonlinear system of ordinary differential equations, suitable nondimensional variables are applied to the governing equations. Then, this system is solved numerically utilizing the Runge‐Kutta‐Fehlberg fourth‐fifth‐order method along with the shooting technique. Maple software was employed to get numerical solutions. The results found that the fluid velocity is retarded for larger estimations of the Hall and Ion parameter. The drag force and the Nusselt number are diminished for higher estimations of the nanoparticle volume fraction and Brinkman number, respectively. Furthermore, it is noted that the nanoparticles have a maximum heat transfer rate as compared with the oxides of nanoparticles. The obtained results are compared with existing ones in a limiting case, and provide good agreement.     

Evaluation of performance of nanofluid using multiwalled carbon nanotubes for machining of Ti–6AL–4V

Machining of titanium alloys generate very high temperature in the cutting zone. This results in rapid tool wear and poor surface properties. Therefore, improvement in cutting performance in machining of titanium alloys is very much dependent on effectiveness of the cooling strategies applied. In the present work, performance of nanofluid using multiwalled carbon nanotubes (MWCNTs) dispersed in distilled water and sodium dodecyl sulfate (SDS) as surfactant is evaluated for turning operation on Ti–6Al–4V workpieces. Turning operations were carried out under three different conditions – dry, with conventional cutting fluid and with nanofluid. Nanofluid application was limited to 1 L/h and it was applied at the tool tip through gravity feed. Various machining responses like cutting force, surface finish and tool wear were analyzed while turning at optimum cutting parameters as 150 m/min, 0.1 mm/rev and 1 mm depth of cut. Later on, machining performance of nanofluid is confirmed at low cutting speed of 90 m/min. Nanofluid outperformed conventional cutting fluid with 34% reduction in tool wear, average 28% drop in cutting forces and 7% decrease in surface roughness at cutting speed of 150 m/min.     

Hall effects on MHD couple stress fluid flow through a vertical microchannel subjected to heat generation: A numerical study

The present study analyzes the irreversibility in an electrically conducting couple stress fluid between two vertical channel plates with the aspects of exponential space and temperature-dependent, radiative heat flux, heat generation, and Joule heating. A reduced system of the governing equations is obtained via applying suitable nondimensional variables. To determine the solutions of velocity, thermal field, irreversibility, and irreversibility ratio, the Runge-Kutta-Fehlberg method along with the shooting technique has been employed. The various pertinent parameters that are involved in the problem have been discussed in detail through graphs. The results show that the entropy production can improve with the viscous dissipation, Joule heating, exponential space and temperature-dependent, and radiative heat flux. Furthermore, it is clear that the entropy enhances with wall ambient temperature difference, radiation parameter, and the effect is reversed with higher estimations of the fluid wall interaction parameter, couple stress parameter, and rarefaction. The present numerical results are compared with the existing results that are in good agreement.     

Thermoplastic multiphase composites: Tensile and creep behavior

It is shown that the strength of the investigated composite in which the concentration of chlorinated polyethylene can be as high as 60% (i.e., under the assumption that the matrix is formed by low-density polyethylene) is fairly well predicted by using the Smith-Nielsen lattice model. In turn, the experimental values of the modulus of elasticity for various compositions based on low-density polyethylene and chlorinated polyethylene can be predicted within the framework of the Hashin-Shtrikman variation fork and the creep of the same systems is predicted according to the power law. The concentration dependences of the elastic modulus and creep compliance for the investigated thermoplastic materials are S-shaped due to their multiphase structure. Thus, the elastic and creep properties of the composites can be successfully predicted for a fairly broad range of compositions. Published in Fizyko-Khimichna Mekhanika Materialiv, Vol. 42, No. 6, pp. 49–54, November–December, 2006.     

A comparison of two murine monoclonal antibodies humanized by CDR-grafting and variable domain resurfacing

The variable domain resurfacing and CDR-grafting approachesto antibody humanization were compared directly on the two murinemonoclonal antibodies N901 (anti-CD56) and anti-B4 (anti-CD19).Resurfacing replaces the set of surface residues of a rodentvariable region with a human set of surface residues. The methodof CDR-grafting conceptually consists of transferring the CDRsfrom a rodent antibody onto the Fv framework of a human antibody.Computer-aided molecular modeling was used to design the initialCDR-grafted and resurfaced versions of these two antibodies.The initial versions of resurfaced N901 and resurfaced anti-B4maintained the full binding affinity of the original murineparent antibodies and further refinements to these versionsdescribed herein generated five new resurfaced antibodies thatcontain fewer murine residues at surface positions, four ofwhich also have the full parental binding affinity. A mutationalstudy of three surface positions within 5 Å of the CDRsof resurfaced anti-B4 revealed a remarkable ability of the resurfacedantibodies to maintain binding affinity despite dramatic changesof charges near their antigen recognition surfaces, suggestingthat the resurfacing approach can be used with a high degreeof confidence to design humanized antibodies that maintain thefull parental binding affinity. By comparison CDR-grafted anti-B4antibodies with parental affinity were produced only after seventeenversions were attempted using two different strategies for selectingthe human acceptor frameworks. For both the CDR-grafted anti-B4and N901 antibodies, full restoration of antigen binding affinitywas achieved when the most identical human acceptor frameworkswere selected. The CDR-grafted anti-B4 antibodies that maintainedhigh affinity binding for CD19 had more murine residues at surfacepositions than any of the three versions of the resurfaced anti-B4antibody. This observation suggests that the resurfacing approachcan be used to produce humanized antibodies with reduced antigenicpotential relative to their corresponding CDR-grafted versions.     

The Influence of KrF Excimer Laser Annealing on Magnetic and Structural Properties of FePt/PtIr Thin Films

A series of 60-nm FePt thin films were deposited by RF magnetron sputtering system on Si/SiO₂ substrate. Platinum–iridium alloy was deposited as a buffer film between the FePt thin film and Si/SiO₂ substrate. These films were annealed by KrF excimer laser annealing with 248 nm of wavelength. The number of laser pulses which were applied on the film was varied from 3 to 20. The A₁ to L₁₀ phase transformation of FePt was confirmed by X-ray diffraction. Three pulses of laser were not sufficient for A₁ to L₁₀ phase transformation. A maximum order parameter of 0.91 was obtained after applying 18 pulses of laser. The roughness of films changed in different pulses, and the films were in the best condition after applying 18 pulses; the roughness was 3.51 nm and its morphology that was observed from AFM was 129 nm. The maximum coercivity was 0.61 MA/m. The coercivity increased with the application of different pulses of laser. Increasing coercivity to the maximum value of 0.61 MA/m related to grain growth. Coercivity of samples in 3, 6, 9, 12, 18, and 20 pulses was 0.24, 0.402, 0.488, 0.522, 0.64, and 0.6 MA/m respectively. Determining the grain growth under condition of annealing was done by field emission scanning electron microscopy (FESEM). Growth of all specimens was calculated with imager software. Grain size in as deposited and 3, 6, 9, 12, and 18 pulses of laser was 15, 20, 29, 44, 47, and 59 respectively.     

Mass transfer coefficient in the eductor liquid-liquid extraction column

In this research gasoil desalting was investigated from mass transfer point of view in an eductor liquid–liquid extraction column (eductor-LLE device). Mass transfer characteristics of the eductor-LLE device were evaluated and an empirical correlation was obtained by dimensional analysis of the dispersed phase Sherwood number. The Results showed that the overall mass transfer coefficient of the dispersed phase and extraction efficiency have been increased by increasing Sauter mean diameter (SMD) and decreasing the nozzle diameter from 2 to 1 mm, respectively. The effects of Reynolds number (Re), projection ratio (ratio of the distance between venturi throat and nozzle tip to venturi throat diameter, R_pr), venturi throat area to nozzle area ratio (R_th-n) and two phases flow rates ratio (R_Q) on the mass transfer coefficient (K) were determined. According to the results, K increase with increasing Re and R_Q and also with decreasing R_pr and R_th-n. Semi-empirical models of drop formation, rising and coalescence were compared with our proposed empirical model. It was revealed that the present model provided a relatively good fitting for the mass transfer model of drop coalescence. Moreover, experimental data were in better agreement with calculated data with AARE value of 0.085.     

A human–food web–animal interface on the prevalence of food-borne pathogens (Clostridia and Enterococcus) in mixed veterinary farms

Food Science and Biotechnology - In the present work, we addressed the impact of a human–food web–animal interface on the prevalence of food-borne pathogens in mixed farms of Tamil...     

Accumulation of vasicine and vasicinone in tissue cultures of Adhatoda vasica and evaluation of the free radical-scavenging activities of the various crude extracts

The indigenous medicinal plant, Adhatoda vasica (L.) Nees. (Acanthaceae), commonly known as vasaka, is used as a herbal remedy for allergen-induced bronchial obstruction, asthma, and tuberculosis and possesses hepatoprotective activity. This plant is a natural source of vitamin C. Tissue cultures of A. vasica, initiated on Murashige and Skoog’s medium supplemented with various plant growth regulators, showed the presence of alkaloids, vasicine and vasicinone. Water extracts of shoot cultures contained high levels of these alkaloids. The vasicine and vasicinone contents in these extracts were 5.98% and 5.2% of dry weight and the water extracts of the selected elite parent plant contained 3–4% dry weight of vasicine. The methanolic extracts of the parent plant and shoot cultures showed quantitative differences in the level of both vasicine and vasicinone. Maximum free radical-scavenging activity of DPPH radicals was observed in the water extracts.