Showing 5 results for abyar
Aradakan abyar, Aradakan Bamdadi, Aradakan Behjatmanes,
Volume 11, Issue 3 (Summer 2020)
Abstract
In the present study, the structure of three common anticancer drugs including 6-thioguanine (6-TG), hydroxyurea (NH) and busulfan were optimized using quantum computational and obtained minimum energy for them. Also, optimization structure of gold nanoparticle was investigated by density functional theory (DFT). Finally, the binding energy of Au nanoparticle was calculated with the optimized structures of drugs. All different sites of drugs that can be interacted with nanoparticle were considered and the most stable structure was chosen for further study. These calculations were performed using FHI-aims which is a software package based on DFT. The bond length and the best interaction energy were reported in this work. To better investigation of the location of the interaction, the type of orbitals involved in the interaction and their shapes are shown. Gap energy analysis showed that the lowest energy was related to the complex of gold nanoparticle with 6-thioguanine, which confirms the chemical stability of this drug with nanoparticle. Investigations showed that the binding energy of gold nanoparticle with drugs is busulfan > hydroxyurea> 6-thioguanine so busulfan has more affinity to bind with gold nanoparticle.
Au nanoparticle as an anticancer drug deliver was studied with the molecular docking calculations. The human albumin serum (HSA) binding with three anticancer drugs was docked individually with Hex 8 software and their active sites of interaction were shown as well as. Finally, the binding energies and types of interactions such as electrostatic, van der Waals and hydrogen bonds between HSA and Au@ drugs were presented, clearly.
Volume 13, Issue 7 (10-2013)
Abstract
Abstract: Wire electrical discharge machining (wire-EDM) has a significant position among production technologies mainly due to its capacity of machining hard materials and intricate shapes. One of the major problems with this process is the error in cutting corners. Processing forces acting on the wire and low rigidity of the wire are responsible for wire deformation, which has a direct influence on the accuracy of the corner cutting. In this research, investigation is focused on the convex corner radii errors and alternative solutions are proposed for the case of successive cuts (one roughing and two finishings). Experiments are carried out for roughing operation by considering frequency of discharges and feed speed. The residual materials on straight and curved paths are the output parameters. Results indicate that optimization of these parameters have a better influence for control of residual material thickness on straight paths than on curved corners. One important conclusion is that roughing is the most influential stage of cutting by WEDM. Then, concave corner radii produced during successive cuts, the effect of corner angle and corner radii are investigated. Errors at radii of different corner angles are identified and related to arc length and residual material thickness in the curved corner. Finally, an effective approach is presented for improving the accuracy of the small-radius concave corner radii of finishing stage. The main conclusion is that to achieve accurate corner radii, one must increase the traversed corner arc length by wire in the small-radius concave corner radii.
Volume 16, Issue 5 (7-2016)
Abstract
In many cases, journal vibrations in the radial direction have been observed in the various rotating machinery using journal bearing. In this investigation the effects of forced oscillation of a journal on the hydrodynamic pressure profile of a two dimensional plain journal bearing are evaluated. Gambit and ANSYS- Fluent software are used to produce mesh and simulate the flow field respectively. Fluid is Newtonian and viscosity is constant. Also, flow is laminar, isothermal, and heat transfer is neglected. It is assumed that there is no phase change and cavitation does not exist. A user defined function is written in C language and compiled by Fluent to apply the oscillation motion to the journal. Results are obtained for three non-dimensional vibration frequencies of journal (0.001, 0.1 and 1), and two eccentricity ratios (0.54 and 0.8). Results show that the hydrodynamic pressure profile is significantly dependent on the oscillation frequency of journal. It can be observed that the pressure distribution variations are independent of frequency when oscillation frequency is low. However, the pressure distribution is considerably affected by increasing oscillation frequency which leads to appearing different hydrodynamic pressure distribution. These influences become more and more intense by rising non-dimensional vibration frequency ratios specially when it is 1.
Volume 18, Issue 6 (10-2018)
Abstract
The purpose of this work is to provide a model in lattice Boltzmann method for D simulating thermal rarified gas flows. The study model is a microchannel with a square cross section. The magnetic field flux was created by the magnets on two facing walls. The electrodes are embedded on the walls adjacent to that of the magnets and DC voltage is applied at both ends. Compressible fluid behavior is compared in slip (Kn =0.15) and transient (Kn =0.1) regimes. There are assumptions of laminar and steady flow. Newtonian fluid is electrically and magnetically conductive. Slip and temperature jump on the microchannel walls are considered and the effects of electric double layer thickness and changes of Hartmann number are studied. Since the ionic process is non-isothermal, energy equation is coupled with that of the velocity and the magnetic field and the effects of interaction forces of Lorentz, electric and electrothermal have been entered into Boltzmann equations in separate terms. The outcomes show the interaction between an axial electric field and a transverse magnetic field results in three-dimensional nature of the flow. Navier-Maxwell second order slip boundary condition imposed on the electromagnetic channel walls plays an important role in the vortices formation and the temperature distribution across the channel goes out of the symmetric state. Mass flow rate loss along the channel, resulting from the fluid rarefaction, and pressure deviation from linearity, across and along the channel axis because of the compressibility, was observed
Volume 19, Issue 6 (June 2019)
Abstract
Wire Electrical Discharge Machining (WEDM) is known as an advanced manufacturing process, especially for producing delicate and intricate shapes and cutting difficult-to-cut materials. Machining error on is an important problem associated with this process. The current paper investigates experimentally the machining errors of three-stage WEDM on the small straight and arced paths. To reveal the reason behind these errors and to compensate them, residual materials of each cutting stage on the straight and arced corner paths were separately measured and analyzed. Machining errors of each WEDM stage in both paths were accurately considered and the causes of these errors in the straight and small arced paths were experimentally and theoretically determined and discussed. Experiments showed that the roughing stage has such a serious deteriorating influence the machining errors on the arced paths that it cannot be compensated in the following finishing stages. The spark angle domains of the roughing stage on the arced paths were calculated and the effects of these domains on the machining errors due to wire diversion from the programmed path were analyzed. In addition, this research proposes a novel guide in multi-stage WEDM by defining some machining concepts and developing equations for error calculation of WEDM finishing stages on these paths. The machining errors estimated by equations have consistency with the related experimental ones. of this study can be employed in the accurate WEDM cuttings.
