Sharif Digital Repository

This paper describes a novel Direct Torque Control (DTC) method for adjustable speed Doubly-Fed Induction Machine (DFIM) drives which is supplied by a two-level Space Vector Modulation (SVM) voltage source inverter (DTC-SVM) in the rotor circuit. The inverter reference voltage vector is obtained by using input-output feedback linearization control and a DFIM model in the stator a-b axes reference frame with stator currents and rotor fluxes as state variables. Moreover, to make this nonlinear controller stable and robust to most varying electrical parameter uncertainties, a two layer recurrent Artificial Neural Network (ANN) is used to estimate a certain function which shows the machine... 

This review covers the most recent developments of inorganic and organic-inorganic composite coatings for orthopedic implants, providing the interface with living tissue and with potential for drug delivery to combat infections. Conventional systemic delivery of drugs is an inefficient procedure that may cause toxicity and may require a patient's hospitalization for monitoring. Local delivery of antibiotics and other bioactive molecules maximizes their effect where they are required, reduces potential systemic toxicity and increases timeliness and cost efficiency. In addition, local delivery has broad applications in combating infection-related diseases. Polymeric coatings may present some... 

This review covers the most recent developments of inorganic and organic-inorganic composite coatings for orthopedic implants, providing the interface with living tissue and with potential for drug delivery to combat infections. Conventional systemic delivery of drugs is an inefficient procedure that may cause toxicity and may require a patient's hospitalization for monitoring. Local delivery of antibiotics and other bioactive molecules maximizes their effect where they are required, reduces potential systemic toxicity and increases timeliness and cost efficiency. In addition, local delivery has broad applications in combating infection-related diseases. Polymeric coatings may present some... 

This article presents experimental results on the electrophoretic deposition (EPD) of bioresorbable chitosan/45S5 Bioglass® composite coatings for orthopaedic implants based on the Taguchi design of experiments (DOE) approach. The influence of EPD parameters including Bioglass® concentration, electric voltage and deposition time on deposition yield was studied by an orthogonal Taguchi array of L18 type. Multivariate analysis of variance (MANOVA) and regression analysis based on the partial least-square method were used to identify the significant factors affecting the deposition yield and its stability during constant-voltage EPD. The coatings were characterised by high resolution scanning... 

This paper presents a study of the Taguchi design method to optimise the rate of electrophoretic deposition (EPD) of Bioglass® particles from aqueous suspensions. The effect of Bioglass® concentration, pH and electric field was investigated. An orthogonal array of L16 type with mixed levels of the control factors was utilized. Multivariate analysis of variance (MANOVA) and regression analysis based on the partial least-square method were used to identify the significant factors affecting the deposition rate and its stability during constant-voltage EPD. It was found that the pH of the suspension significantly influences the deposition rate whereas the applied electric field has the smallest... 

Distributed optical fiber sensors (DOFS) based on stimulated Brillouin scattering (SBS) are increasingly gaining popularity due to their vast practical applications. There have been a lot of Brillouin-based distributed fiber sensing methods proposed so far but they suffer from a trade-off between spatial resolution, dynamic range and measurement time. In this paper, we propose a scanning-free Brillouin optical time domain analyzer (BOTDA) based on multiple short pulse stimulated Brillouin scattering. The accumulation of acoustic phonons which are stimulated due to the passage of successive pico-second pulses along the sensing fiber causes the sub-centimeter spatial resolution and kilometer... 

Magnesium (Mg) and its alloys have proved promising as biodegradable candidates for the repair of bone tissue. Despite the encouraging bio-related properties of Mg, its high corrosion rate in contact with body fluids still presents a major challenge. An efficient approach to address this issue is to provide a protective coating on Mg. The present research evaluates, for the first time, in vitro bioactivity and biocompatibility of a novel multifunctional composite coating based on poly(methyl methacrylate) (PMMA) biopolymer and bioactive glass (BG) particles on Mg-based implant. Electrophoretic deposition (EPD) was utilized to obtain this coating from a bi-component suspension. Coatings’... 

The biodegradation behavior of Mg, coated by polymethyl methacrylate as well as polymethyl methacrylate (PMMA)−bioactive glass (BG) composite was investigated. Electrophoretic deposition and dip coating techniques were adopted to prepare composite coating using a suspension of different percentages of the above two chemical materials. The deposited coatings were characterized using SEM, EDS, FTIR, and water contact angle measurements. Biodegradation behavior study of the coated Mg was performed using linear polarization, impedance spectroscopy, and immersion tests in simulated body fluid. The compact and homogeneous composite coating was developed as evidenced by electron microscopy results.... 

The rare presence of circulating tumor cells (CTCs) in the bloodstream has made their recording and separation one of the major challenges in the recent decade. Inertia-based microfluidic systems have received more attention in CTCs separation due to their feasibility and low cost. In this research, an inertial microfluidic system is proposed using a curved expansion-contraction array (CEA) microchannel to separate CTCs from white blood cells (WBCs). First, the optimal flow rate of the proposed microfluidic device was determined to maximize the separation efficiency of the target cells (CTCs) from the non-target ones (WBCs). Then, the efficiency and purity of the straight and curved-CEA... 

In this study, frequency simulation and critical angular velocity of a size-dependent laminated rotary microsystem using modified couple stress theory (MCST) as the higher-order elasticity model is undertaken. The centrifugal and Coriolis impacts due to the spinning are taken into account. The size-dependent thick annular microsystem's computational formulation, non-classical governing equations, and corresponding boundary conditions are obtained by using the higher-order stress tensors and symmetric rotation gradient to the strain energy. By using a single material length scale factor, the most recent non-classical approach captures the size-dependency in the annular laminated microsystem.... 

In this study, frequency simulation and critical angular velocity of a size-dependent laminated rotary microsystem using modified couple stress theory (MCST) as the higher-order elasticity model is undertaken. The centrifugal and Coriolis impacts due to the spinning are taken into account. The size-dependent thick annular microsystem's computational formulation, non-classical governing equations, and corresponding boundary conditions are obtained by using the higher-order stress tensors and symmetric rotation gradient to the strain energy. By using a single material length scale factor, the most recent non-classical approach captures the size-dependency in the annular laminated microsystem.... 

Cell-based diagnosis and the introduction of personalized drugs are key factors, motivating researchers to discover an efficacious tool for effective cell isolation. Optimal systems were presented through the finite element method by adjusting the arrangement of hydrodynamic forces within a serpentine micro-channel, which managed to separate different cell lines in addition to their focusing. Considering the parameters of flow, particle, and geometry, two optimal serpentine systems (fixed and variable slope) were presented and the accuracy of the simulation results was verified by their comparison with the experimental findings of the optimized microchannel. The results indicated that the... 

Addressing breast cancer is an ongoing global health concern, demanding constant progress in treatment approaches due to its high incidence and mortality rates. In recent years, there has been a surge in research focusing on the intersection of genetic bioengineering and nanotechnology for the development of targeted pharmaceutical treatments. This review paper delves into the biological, pharmacological, and biochemical impacts of utilizing nanomaterials-based therapies in breast cancer. Specifically, it explores the utilization of genetic bioengineering techniques to tailor nanocarriers for precise targeting of cancer cells while minimizing harm to healthy tissues. The paper discusses the...