DESIGNING A NON-LINEAR TRACKING CONTROLLER FOR VEHICLE ACTIVE SUSPENSION SYSTEMS USING AN OPTIMIZATION PROCESS

A. MALEKSHAHI,M. MIRZAEI 한국자동차공학회 2012 International journal of automotive technology Vol.13 No.2

In this paper, a new non-linear tracking controller for vehicle active suspension systems is analytically designed using an optimization process. The proposed scheme employs a realistic non-linear quarter-car model, which is composed of a hardening spring and a quadratic damping force. The control input is the external active suspension force and is determined by minimizing a performance index defined as a weighted combination of conflicting objectives, namely ride quality, handling performance and control energy. A linear skyhook model with standard parameters is used as the reference model to be tracked by the controller. The robustness of the proposed controller in the presence of modeling uncertainties is investigated. The performed analysis and the simulation results indicate that both vehicle ride comfort and handling performance can be improved using the minimum external force when the proposed non-linear controller is engaged with the model. Meanwhile, a compromise between different objectives and control energy can easily be made by regulating their respective weighting factors, which are the free parameters of the control law.

Kinetic study of CO hydrogenation on the MgO supported Fe–Co–Mn sol–gel catalyst

A.A. Mirzaei,A. Pourdolat,M. Arsalanfar,H. Atashi,A.R. Samimi 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4

The kinetic of the Fischer–Tropsch synthesis over the MgO supported Fe–Co–Mn catalyst prepared using sol–gel procedure, was investigated in a fixed bed micro-reactor. Experimental conditions were varied as follow: reaction pressure 5–20 bar, reaction temperature 220–250 8C, H2/CO feed molar ratio of 0.67–2and space velocity range of 2400–3600 h1. 18 models according to the Langmuir–Hinshelwood–Hougen–Watson (LHHW) type rate equation were derived, and the reaction rate is fitted fairly well by one kinetic expressions based on LHWW mechanism. The kinetic parameters were estimated with nonlinear regression method. The activation energy was obtained 110.9 kJ/mol for the best-fitted model.

Discovery of Novel Cell Surface Markers for Purification of Embryonic Dopamine Progenitors for Transplantation in Parkinson's Disease Animal Models

Fathi, Ali,Mirzaei, Mehdi,Dolatyar, Banafsheh,Sharifitabar, Mehdi,Bayat, Mahnaz,Shahbazi, Ebrahim,Lee, Jaesuk,Javan, Mohammad,Zhang, Su-Chun,Gupta, Vivek,Lee, Bonghee,Haynes, Paul A.,Baharvand, Hossei American Society for Biochemistry and Molecular Bi 2018 Molecular and Cellular Proteomics Vol.17 No.9

<P>Despite the progress in safety and efficacy of cell replacement therapy with pluripotent stem cells (PSCs), the presence of residual undifferentiated stem cells or proliferating neural progenitor cells with rostral identity remains a major challenge. Here we report the generation of a LIM homeobox transcription factor 1 alpha (LMX1A) knock-in GFP reporter human embryonic stem cell (hESC) line that marks the early dopaminergic progenitors during neural differentiation to find reliable membrane protein markers for isolation of midbrain dopaminergic neurons. Purified GFP positive cells in vitro exhibited expression of mRNA and proteins that characterized and matched the midbrain dopaminergic identity. Further quantitative proteomics analysis of enriched LMX1A(+) cells identified several membrane-associated proteins including a polysialylated embryonic form of neural cell adhesion molecule (PSA-NCAM) and contactin 2 (CNTN2), enabling prospective isolation of LMX1A(+) progenitor cells. Transplantation of human-PSC-derived purified CNTN2(+) progenitors enhanced dopamine release from transplanted cells in the host brain and alleviated Parkinson's disease-related phenotypes in animal models. This study establishes an efficient approach for purification of large numbers of human-PSC-derived dopaminergic progenitors for therapeutic applications.</P>

Effects of Prepartum Dietary Carbohydrate Source on Metabolism and Performance of Primiparous Holstein Cows during the Periparturient Period

Mirzaei Alamouti, H.R.,Amanlou, H.,Rezayazdi, K.,Towhidi, A. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.11

Forty-six Holstein heifers were used in a completely randomized design and assigned to 1 of 2 treatments to evaluate the effects of 2 diets varying in ruminal fermentable carbohydrate sources, namely ground corn (GC) and rolled wheat (RW), on metabolism and performance of primiparous cows in the periparturient period. The heifers were fed diets as a total mixed ration (TMR) with similar energy and crude protein content including i) 18.57% GC, or ii) 18.57% RW from -24.13${\pm}$7.73 d relative to expected calving until calving. After calving, all animals received the same lactation diet until 28 d. Animals were group fed from the beginning of the study to -7 d relative to expected calving, fed individually from d -7 to 7 days in milk (DIM), and again group fed to 28 DIM. The pre-partum diets affected (p<0.05) dry matter intake (DMI), energy intake, energy balance (EB) and urinary pH during the last week pre-partum. There was no effect of pre-partum carbohydrate source on overall plasma concentration of glucose, nonesterified fatty acid (NEFA), $\beta$-hydroxybutyrate (BHBA), albumin, triglyceride (TG), cholesterol, aspartate aminotransferase (AST), insulin, and cortisol during the periparturient period. Cows fed the RW diet during the pre-partum period had greater calcium for the first week (p<0.05) and during 28 d (p = 0.08) of lactation compared with heifers fed the GC diet. Primiparous cows fed the RW diet produced greater milk protein content and yield (p<0.05). Primiparous cows fed the RW diet had lower milk urea nitrogen (MUN) and somatic cell count (SCC) than cows fed the GC diet (p<0.05). The results of this study show that feeding pre-partum diets with a rapidly fermentable source of starch but low energy content can improve animal metabolism and performance and smooth the transition of primiparous Holstein cows from gestation to lactation.

Surprising synthesis of nanodiamond from single-walled carbon nanotubes by the spark plasma sintering process

Mirzaei, A.,Ham, H.,Na, H. G.,Kwon, Y. J.,Kang, S. Y.,Choi, M. S.,Bang, J. H.,Park, N. H.,Kang, I.,Kim, H. W. Springer Science + Business Media 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.6

<P>Nanodiamond (ND) was successfully synthesized using single-walled carbon nanotubes (SWCNTs) as a pure solid carbon source by means of a spark plasma sintering process. Raman spectra and X-ray diffraction patterns revealed the generation of the cubic diamond phase by means of the SPS process. Lattice-resolved TEM images confirmed that diamond nanoparticles with a diameter of about similar to 10 nm existed in the products. The NDs were generated mainly through the gas-phase nucleation of carbon atoms evaporated from the SWCNTs.</P>

ZnO-capped nanorod gas sensors

Mirzaei, A.,Park, S.,Kheel, H.,Sun, G.J.,Lee, S.,Lee, C. Ceramurgica ; Elsevier Science Ltd 2016 Ceramics international Vol.42 No.5

This paper reports on the synthesis of pristine α-Fe<SUB>2</SUB>O<SUB>3</SUB> nanorods and Fe<SUB>2</SUB>O<SUB>3</SUB>-ZnO core-shell nanorods using a combination of thermal oxidation and atomic layer deposition (ALD) techniques; the completed nanorods were then used for ethanol sensing studies. The crystal structure and morphology of the synthesized nanostructures were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The sensing properties of the pristine and core-shell nanorods for gas-phase ethanol were examined using different concentrations of ethanol (5-200ppm) at different temperatures (150-250<SUP>o</SUP>C). The XRD and SEM revealed the excellent crystallinity of the Fe<SUB>2</SUB>O<SUB>3</SUB>-ZnO core-shell nanorods, as well as their uniformity in terms of shape and size. The Fe<SUB>2</SUB>O<SUB>3</SUB>-ZnO core-shell nanorod sensor showed a stronger response to ethanol than the pristine Fe<SUB>2</SUB>O<SUB>3</SUB> nanorod sensor. The response (i.e., the relative change in electrical resistance R<SUB>a</SUB>/R<SUB>g</SUB>) of the core-shell nanorod sensor was 22.75 for 100ppm ethanol at 200<SUP>o</SUP>C whereas that of the pristine nanorod sensor was only 3.85 under the same conditions. Furthermore, under these conditions, the response time of the Fe<SUB>2</SUB>O<SUB>3</SUB>-ZnO core-shell nanorods was 15.96s, which was shorter than that of the pristine nanorod sensor (22.73s). The core-shell nanorod sensor showed excellent selectivity to ethanol over other VOC gases. The improved sensing response characteristics of the Fe<SUB>2</SUB>O<SUB>3</SUB>-ZnO core-shell nanorod sensor were attributed to modulation of the conduction channel width and the potential barrier height at the Fe<SUB>2</SUB>O<SUB>3</SUB>-ZnO interface accompanying the adsorption and desorption of ethanol gas as well as to preferential adsorption and diffusion of oxygen and ethanol molecules at the Fe<SUB>2</SUB>O<SUB>3</SUB>-ZnO interface.

Hybrid Modeling of the Non-inverting Buck-Boost DC-DC Converter

Mahmood Mirzaei,Ali A. Afzalian 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

In this paper hybrid models for the Non-inverting Buck-Boost converter are derived using Mixed Logical Dynamical (MLD) and Piecewise Affine (PWA) modeling frameworks. Hybrid automaton of the system is obtained and used to determine variation ranges of state variables and also to check accuracy of the models. This model is not suitable for control design in our intended strategy. Firstly two MLD models of the system are derived. v-Resolution method is used to capture hybrid nature of the converter and two different models with different levels of complexities are obtained. HYbrid Systems DEscription Language (HYSDEL) is used as a tool for generating the MLD models. Secondly v-Resolution method and piecewise affine approximation of nonlinear dynamics based on Least Squares Fitting (LSF) are employed to derive PWA models of the system. Three PWA models are obtained and compared in terms of complexity and accuracy. In the end, accuracy of the models is compared.

Kinetic study of CO hydrogenation over co-precipitated iron–nickel catalyst

Ali A. Mirzaei,Rouhoullah M. Kiai,Hossein Atashi,Maryam Arsalanfar,Sara Shahriari 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.4

The kinetic of the Fischer–Tropsch synthesis over a Fe–Ni/Al2O3 catalyst was investigated in a fixed bed micro reactor. Experimental conditions were varied as follow: reaction pressure 2–10 bar, H2/CO feed ratio of 2/1 and space velocity of 96–450 cm3(STP)/h/gramcatalyst at the temperature range 523–573 K. On the basis of carbide-enol mechanism and Langmuir–Hinshelwood–Hougen–Watson (LHHW) type rate equations, seventeen kinetic expressions for CO consumption were tested and interaction between adsorption HCO and dissociated adsorption hydrogen as the controlling step gave the most plausible kinetic model. The activation energy was 46.5 kJ/mole for optimal kinetic model.

Explicit Model Predictive Control of the Non-inverting Buck Boost DC-DC Converter

Mahmood Mirzaei,Ali A. Afzalian 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

In this paper recent works on hybrid control of DC-DC converters is extended to the Non-inverting Buck Boost converter. Hybrid automaton model of the converter is obtained to check the behavior of the converter and also to be used in simulations. Piecewise affine (PWA) model of the converter is derived as a predictive model and model predictive control is formulized on the obtained model to fulfill defined control objectives. The explicit solution to the problem of the defined optimal control is presented and the performance of the obtained controller is evaluated in three scenarios namely startup, change in the load resistance and the source voltage. The simulations are provided for Buck and Boost operational modes of the converter to check the performance of the controlled system.

Numerical investigation of oscillation frequency and amplitude effects on the hydrodynamic coefficients of a body with NACA0012 hydrofoil section

M. H. Shojaeefard,A. Khorampanahi,M. Mirzaei 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.5

We propose a comprehensive numerical procedure to calculate the hydrodynamic coefficients of a moving body with NACA0012 hydrofoil by means of Computational fluid dynamics (CFD). To accomplish maneuverability study and dynamic analysis of an Autonomous underwater vehicle (AUV), these hydrodynamic coefficients were obtained by finding the body hydrodynamic responses to some specified time variant motions. Here, on the basis of linearized equations of motion in which the hydrodynamic coefficients appear explicitly, three distinct oscillating maneuvers are proposed. To obtain the hydrodynamic responses of the moving body, a CFD method based on Reynolds averaged Navier-Stokes (RANS) equations was used with dynamic mesh technique to simulate the specified maneuvers. To verify the numerical scheme, the computational results were then validated by comparison with experimental data. Hydrodynamic coefficients were calculated from resulting hydrodynamic loads. Finally, the effects of oscillating motions frequency and amplitude variations on the hydrodynamic coefficients were investigated.