---

Hypothesis: The aim of this research was the investigation on kinetic of curing reaction of polyurethane binder based on hydroxyl terminated polybutadiene (HTPB). This reaction is of particular interest in advanced polyurethane composite materials.
Methods: HTPB diol was dynamically cured using differential scanning calorimetery (DSC) at different heating rates (5, 10, 20 and 40° C/min) with curing agents of Toluene Diisocyanate (TDI) and Isophorone Diisocyanate (IPDI) in presence and absence of Dibutyltin Dilaurate (DBTDL) catalyst. Kinetic parameters were calculated using Kissinger, Ozawa and isoconversion models. Urethane formation and viscosity build-up during cure reaction was studied by Fourier Transform Infrared Spectroscopy (FT-IR) and rotational visocmetery (RV) methods.
Findings: Results showed that activation energy, enthalpy, progress and the rate of reaction were influenced by type of curing agent and the presence of catalyst. Kinetic models showed activation energy was reduced about 1 kJ/mol at each 0.05 unit increase in the degree of cure. The activation energy of HTPB-TDI-DBTDL binder system versus degree of cure was reduced slower in comparison to HTPB-IPDI-DBTDL binder system. Decrease in activation energy at degrees of cure higher than 90% was intensified as probable diffusion of low molecular weight molecules into polymer chains. Enthalpy of reaction in HTPB-TDI-DBTDL binder system at heating rates of higher than 10° C/min was independent of heating rate, whereas in HTPB-IPDI-DBTDL binder system the enthalpy of reaction is highly dependent on heating rate. Chemorheological results showed that rate of curing reaction for binder systems are in the order of HTPB-TDI-DBTDL>HTPB-IPDI-DBTDL>HTPB-TDI.

---

In this study, generation of the transient evoked ooacoustic emissions in human ear has been simulated using a new electroacoustic model. The method of state variables was adopted to calculate the auditory model, and numerical integration methods have been used to solve differential equations in Matlab. Simulation results have been compared with the real data. In this study, latency curves, frequency spectrum of the simulated TEOAE and calculation errors were used to validate of the model. The results of this research show that simulated outputs are similar to clinical data.

---

The prerequisite in the majority of control processes is modeling. The model used to design a controller must be both accurate and real-time. Utilizing prevalent approaches of modeling, namely modeling based on (numerically) solving the equations governing the fluid in the combustion chamber, is too time-consuming and not suitable for a control purpose. This paper is to model combustion in an SI engine by means of neural networks and present an accurate and fast-response model for combustion. Obviously, any training procedure of neural networks does involve empirical data acquisition. On the other hand, engine testing is highly expensive, and testing data tables available (in industry) are not sufficient to train neural networks. In this paper, first with the aid of a CFD software, a one-dimensional model of an engine is constructed, and then calibrated using factual experimental data at hand. Afterwards, acquiring data required is performed via the validated CFD model. As a matter of fact, because of not having access to necessary experimental coefficients, calibration is an extremely complicated and time-consuming process. It will be attempted to accomplish and spell out the calibration of the engine model in the GT-Power software, in a scientific practice. After a brief survey on the methods employed in designing the neural networks, modeling of the combustion chamber will be stated. Eventually, the response of the constructed NN model will be compared to the results gained from the GT-Power software, and the great accuracy of the NN model will be indicated.

---

The problem of two wheeled self-balancing robot is an interesting and challenging problem in control and dynamic systems. This complexity is due to the inherent instability, nonholonomic constraints, and under-actuated mechanism. Dynamical model of two wheeled self-balancing robot can be presented by a set of highly coupled nonlinear differential equations. Authors, previously, developed the modified dynamical equations of the robot. The governed equations have some differences with the commonly used equations. The main difference is due to the existence of a nonlinear coupling term which is neglected before. In this paper we used an adaptive sliding-mode controller based on the zero dynamics theory. The controller objective is to drive the two wheeled self balancing robot to the desired path as well as to make the robot stable. By some simulations the behavior of the robot with the proposed controller is discussed. It is shown that if the nonlinear coupling term is ignored in designing the controller, the controller cannot compensate its effect. Using Lyapunov theorem and the invariant set theorem, it is proved that the errors are globally asymptotically stable.

---

The low temperature combustion (LTC) concept is the groundwork of most recent developments in internal combustion diesel engines in order to match stringent environmental standards and regulations. Although, its basic definition which means reducing the combustion chamber temperature to decrease the emissions sounds easy but practical achievement of LTC strategies which can be feasible in a wide range of loads and speeds has its own difficulties. With attention to different effective parameters in a diesel engine combustion process, various methods have been introduced for the purpose of LTC achievement. Two important types of these methods are based upon early and late injection strategies. In addition to analyzing the both mechanisms, in this paper we are intended to implement two different methods in national light duty diesel engine in order to match EURO VI emission standard. One method named UNIBUS is based upon early injection strategies which is benefited from PPC merits and the other one is Modulated Kinetic (MK) which is based upon late injection strategies. Finally both these methods have been compared and contrasted. The results admit the great potentiality of both methods to make a significant and simultaneous reduction in NOx and Soot emissions.

---

Fuel consumption, emissions and output power are some of the very important factors for automotive engine design. Since the combustion efficiency depends on the quality of the air-fuel mixture and mixture quality depends on the fuel injection parameters, the investigation of spray features is an overall goal in direct injection engines. In this paper, simulation of GDI spray is carried out in a constant volume chamber contains nitrogen in four different injection pressure using the AVL Fire software. The results are validated against the Istituto Motori-CNR experimental data. The log-normal probability distribution as an initial droplet diameter and Huh-Gosman model as secondary breakup were used. Then the combustion of EF7 Engine with direct injection was studied and wall film thickness was compared at different injection pressures and injector angles. Also, the effects of wall temperature and single-stage and two-stage fuel injection with different ratios of injected fuel mass were evaluated on the wall film. Since the fuel can be injected into the combustion chamber in both intake and compression stroke according to engine operating conditions in gasoline direct injection engines, the simulation was done for open cycle engine.

---

The main aim of this paper is the numerical investigation of air-fuel mixture formation and spray and combustion characteristics of EF7 engine equipped with spray-guided direct injection system. For this purpose, first, a six-hole injector is simulated in three different injection pressures and to validate the fuel injection characteristics, the results are validated against the Istituto Motori-CNR experimental data. Then, the injector position is selected near the spark plug and by changing of injector angle relative to the axis of combustion chamber, the appropriate angle for optimization mixture formation is obtained. Then, the effect of injection pressure, start of first and second injection as well as the effect of two-stage fuel injection with different proportions of fuel mass at primary and secondary injection are studied on the mixture formation, wall film and engine emissions. The results showed that the injector angle is extremely effective on the mixture formation, pressure and the amount of unburned hydrocarbons due to its direct impact on wall film mass. Also, in the two-stage injection, relatively homogeneous lean mixture compared to the stratified mixture results better combustion at part load condition.

---

In this paper, an improved, real-time, highly accurate control-oriented style, named Neuro Mean Value Modeling, is presented for IC engine modeling. This model is a combination of neural networks and mean value model, and is able to overcome the shortcomings of both styles. In other words, taking advantage of both methods, this -box extension will be of more reliability than a mere black-box neural network, and also of more accuracy than roughly white-box mathematical relations of In this paper, the model is modified to become suitable for designing an engine controller. Thanks to the sophisticated methods applied (such as committee method, improved partitioning, and especially, simplifying neural networks’ tasks), neural networks of high accuracy with line-like regressions will be achieved. As will be seen, the model is precisely validated - and it is capable of accurately predicting the engine’s outputs (such as pollutant emissions, manifold pressure, knock probability, and engine speed) all in real time. In the end, the effect of engine control inputs on pollutant emissions and fuel consumption will be examined. The engine employed to establish the model is a ported fuel injection SI engine.
 

---

This study investigates the effects of water-methanol mixture injection on the performance and emissions of the EF7 TC engine. Using GT Power software, the engine was first simulated and validated with gasoline fuel. Subsequently, a nozzle was used to introduce the water-methanol mixture, simulated in three different ratios: 50% water-50% methanol, 25% water-75% methanol, and 75% water-25% methanol. The novelty of this research lies in the simulation of this injection process to enhance combustion quality. Results indicate significant temperature reductions at various points, alongside notable changes in knock characteristics and emissions, including nitrogen oxides (NOx), carbon monoxide (CO), carbon dioxide (CO₂), and nitrogen monoxide (NO).