---

A time-domain approach is presented to calculate electromagnetic fields inside a large Electromagnetic Pulse (EMP) simulator. This type of EMP simulator is used for studying the effect of electromagnetic pulses on electrical apparatus in various structures such as vehicles, a reoplanes, etc. The simulator consists of three planar transmission lines. To solve the problem, we first model the metallic structure of the simulator as a grid of conducting wires. The numerical solution of the governing electric field integral equation is then obtained using the method of moments in time domain. To demonstrate the accuracy of the model, we consider a typical EMP simulator. The comparison of our results with those obtained experimentally in the literature validates the model introduced in this paper.

---

In SCPC-DAMA satellite networks, the baseband RRC pulse shaping is utilized to reduce the bandwidth and Inter Symbol Interference (ISI). But the variation in carrier's envelope, which expands the spectrum and ultimately increases the bandwidth, causes ISI and Quadrature Channel Crosstalk (QCC). The goal of this paper is to introduce a method to shape baseband RRC pulses, in order to make a nearly constant carrier envelope. We have introduced and implemented an algorithm to limit the amplitude variation of each pulse to generate constant amplitude RRC pulses at the input of modulator. Matlab simulation and hardware experiments show that OQPSK modulation and this pulse shaping method, can improve BER about 2dB.

---

Thermal processing is the most common and traditional method to extend the shelf life of food. Because of negative effects of this processing method on sensory and nutritional properties of food, using of cold methods for sanitization has often been interesting substitutes for thermal treatment. High pressure, pulsed electric field, microfiltration, using of high pressure carbon dioxide and irradiation are such an important of the cold sanitization methods. High pressure processing inactivates microorganisms through deformation of their membrane, changing cell morphology, protein denaturation and inactivation of genetic mechanisms, disruption of ribosomes and denaturation of essential enzymes. Pulsed electric field treatment causes electroporation of the cell membrane wich results destruction of the microorganism. Microfiltration is based on the separation of microorganisms according to size differences with food components. High pressure carbon dioxide technique inactivates microorganisms through deformation of cell membrane, intercellular pH decrease, inactivation of essential enzymes, direct influence on metabolism, disordering of intracellular electrolyte balance, and removal of vital constituents from cell and cell membranes. Finally, irradiation inactivates microorganisms by causing some changes in biological systems. The benefits and defects of these mentioned methods have been investigated in this review paper and exhibited some examples for applications of each of them for sanitization of milk.

---

This paper addresses two questions. Does inflation in Iran stem from fiscal policy? Does inflationary impact depend upon the sources of budget deficit financing? Although the above questions have already been studied, there is no consensus on the findings, since the results are sensitive to the methodologies and the time period covered by the data. This paper employs vector autoregressions, impulse response functions, variance decomposition and cointegration techniques to estimate the short and long term relationship between inflation and a number of fiscal indicators in Iran. The annual data are used over the period 1973 to 2006. Particular emphasis is placed on the government budget deficit predominantly financed by government borrowing. The results indicate that inflation is mostly induced by import prices, oil revenue and government budget deficit.

---

Abstract Ground motions close to a ruptured fault can be significantly different from those further away from the seismic source. In the other hand there are a few real records which include the characteristic of near-fault records. Hence, simulation of these records is useful in order to study their effects on the behavior of structures which has been built near the faults. Tehran is a city in the neighboring of several active faults but there aren’t any nearfault real records in this place. In this paper, according to mechanism and situation of North Tehran Fault (NTF), seven near-fault real records with forward directivity have been selected and by using selected records a pulselike decaying sinusoidal model has been proposed as NTF simulated near-fault records. Finite fault method with specific considerations has been used as a suitable and reliable method for creating near-fault artificial record and the artificial records for NTF has been generated at 2, 5 and 10 km distances. Finally the results for real and artificial records and also the pulse-like model have been compared together.

---

In this paper, the effect of window weighting functions, such as Hamming, Hanning and Nuttulwin, on the Oppermman code is investigated. These codes are used in the poly phase pulse compression technique in radar applications. The results indicate that weightings reduce sidelobes and false alarm extremely. In addition, the target detection ability is increased in this code

---

The combined effects of two major contributing factors, i.e. inertial soil-structure interaction (SSI) and near-fault ground motions, on structural responses were studied. Considering nearfault characteristics, soil-structure systems are subjected to both actual near-fault ground motion records and their dominant kinematic characteristics, i.e. forward rupture-directivity pulses, coherently travelling waves seen as a large amplitude and short duration pulse-type motion at the beginning of each fault-normal component of the record. As a result of the suitability of forward rupture-directivity pulses for quantifying the salient response features of structures, a mathematical model, proposed by Makris, was used to represent the forward rupture-directivity pulse-type motions. Using a comprehensive parametric study, the structure, a bilinear single degree of freedom (SDOF) system, the soil beneath the structure and a homogeneous elastic half-space were combined based on a discrete model to constitute the overall soil-structure model. The results have been presented in the form of elastic strength demand graphs for a wide range of non-dimensional key parameters, which describe the SSI effects. Both the soil-structure systems and the corresponding fixed-base structures were considered and compared. Using numerical time-stepping analyses, it was found that the response of soil-structure systems subjected to actual near-fault records is similar to those subjected to forward rupture-directivity pulses. Consequently, the forward rupture-directivity pulses can be used to predict the salient response features of soil-structure systems in seismically active regions. They can also be a realistic representation of near-fault ground motions for predicting the response of long-period structures. It was further observed that quite interestingly, the response of soil-structure systems subjected to actual near-fault records, has two maximum regions. However, it was recognized that further study would be required to clarify these regions. The results also indicated that considering SSI is critical for a variety of structures. Accordingly, underestimated near-fault responses could be obtained when the SSI effects are ignored.

---

Abstract- Gaseous detonation in tubes produces moving pressure-thermal waves. A gaseous detonation consists of a shock wave and a reaction zone that are tightly coupled. The speed, pressure, and temperature of the products of detonation depend on the type and amount of the initial mixture. The maximum pressure of mechanical wave caused by detonation can be as high as 20-30 times the ambient pressure and temperature of gas in detonation may exceed 2000°C. The mechanical shock waves can cause oscillating strains in the tube wall, which can be several times higher than the equivalent static strains. On the other hand, the passage of the heat wave produces thermal stresses in the tube wall. In the current study the resulting mechanical and thermal stresses have been assessed using numerical simulations. In practice, the mechanical and thermal displacements have been computed separately. Finally, the combined effects of mechanical and thermal stresses caused by gaseous detonation have been simulated.

---

In this paper, the results of a statistical study on inelastic displacement ratio for structures subjected to pulse like near fault ground motions were presented. This study is important because, the results can used for evaluating inelastic displacement demand of structures with known lateral stiffness and strength subjected to near fault ground motions. Inelastic displacement ratio were computed from the response of single-degree-of-freedom systems having 6 level of strength reduction factor when subjected to 61 pulse like near fault records. The influence of period of vibration normalized by period of peak spectral displacement, strength reduction factor, period associated with velocity pulse TP, earthquake magnitude and distance to the source, post-yield stiffness and hysteresis behavior of structure on inelastic displacement are evaluated. Results indicate that strength and stiffness degrading in short period region increase inelastic displacement demands. Finally, a simply equation for estimate the mean of the inelastic displacement ratio for structures subjected to pulse like near fault ground motions is proposed.

---

In this paper, the results of a statistical study on inelastic displacement ratio for structures subjected to pulse like near fault ground motions are presented. This study is important because the results can be used for evaluating inelastic displacement demand of structures with known lateral stiffness and strength subjected to near fault ground motions. Inelastic displacement ratio is computed from the response of single-degree-of-freedom systems having 6 level of strength reduction factor subjected to 61- pulselike near fault records. The influence of period of vibration normalized by period of peak spectral displacement, strength reduction factor, period associated with velocity pulse TP, earthquake magnitude and distance to the source, post-yield stiffness and hysteresis behavior of a structure on inelastic displacement ratiois investigated.For more study on the strength and the stiffness degradation effects on inelastic displacement, three type of hysteresis behavior have been considered. The first type iselasto-plastic behavior. Elasto-plastic behavior is generally used to represent the non-degrading hysteretic behavior. Second and the third typesarethe stiffness degrading and the strength-stiffness degrading hysteretic behavior.Results indicate that strength and stiffness degrading in short period region increases inelastic displacement demands. Further the period associated with velocity pulse plays a main role in inelastic displacement and has a significant effect on it. It is found that strain hardening can reduce inelastic displacement relative to system with perfectly elasto-plastic hysteresis behavior. Magnitude and source to site distance have little effects on inelastic displacement. Finally, a simple equation is proposed for estimating the mean inelastic displacement ratio for structures subjected to pulse like near fault ground motions.

---

In this paper a CFD code has been developed to investigate effects of the double inlet on the performance of a Stirling type pulse tube refrigerator. In this respect, set of governing equations have been written in a general form such that all porous and non-porous sections of the system can be modeled. In order to discretize the governing equations, a second order method has been used for time, a second order upwind method for mass, enthalpy flow and temperature in the surfaces of the control volumes and the central differential scheme has been employed for pressure and heat conduction terms. Results show that application of double inlet optimizes the phase shift between velocity and pressure and suitably decreases the fluid temperature along the pulse tube, causing to increase COP of the system. Furthermore, it is observed that a minimum temperature of 56.5 K and COP of 0.0352 @ 80 K is attainable using optimum double inlet; whereas, for a simple refrigerator a minimum temperature of 71.3 K and maximum COP of 0.0227 @ 80 K are concluded.

---

Poly-γ-glutamic acid (γ-PGA) is a beneficial, biocompatible, and biodegradable biopolymer. These properties have been led to the development of the use of this compound in various industries such as bio-medicine, biopharmaceutical, biotechnology, and tissue engineering. The limitation of the industrial development of γ-PGA is the high cost of its production. To reduce γ-PGA production costs, various strategies are used, such as culture medium optimization using inexpensive compounds, the development of efficient cultivation processes of batch and fed-batch. In this research, first, an efficient batch culture medium was developed to produce γ-PGA of Bacillus licheniformis ATCC 9945^a. Then, the γ-PGA production increased by the pulsed feeding method and its optimization. By optimal culture medium development, the production of this product in batch culture was increased from 11 g/L to 47 g/L. Then, using the optimized pulsed feeding strategy of citrate (γ-PGA precursor), γ-PGA production was increased to 59.5 g/L, which is one of the highest production values reported with this strain. To optimize two-pulse feeding, the effect of feeding times, stock citrate solution concentration, and time of calcium and manganese solutions addition on γ-PGA production were investigated and optimized. Finally, FTIR confirmed the chemical structure of poly gamma glutamic acid, and the study of γ-PGA morphological properties with SEM showed a nanostructure ideal for biological applications.

---

In this study the interaction of material and ultrasonic vibration of workpiece at different pulse on times (Ti) and discharge currents (I) in the electrical discharge machining (EDM) has been studied. The materials of machined samples were AISI H13 tool steel and FW4 weld steel. The results show that ultrasonic vibration of workpiece, independent of workpiece material increase material removal rate (MRR) and reduce tool wear ratio (TWR) and surface roughness. Also the results indicate that the effect of ultrasonic vibration on the material removal rate increase of FW4weld steel is higher than AISI H13 tool steel, and the reduction of tool wear ratio of FW4 weld steel is more than AISI H13 tool steel.

---

This paper presents the speed control scheme of indirect vector controlled of induction motor (IM) drive. Voltage source inverter type space vector pulse width modulation (SVPWM) is used for PWM controlling scheme. Regarding the capabilities and potentials of intelligent based on Fuzzy logic in the control of non-linear and complex systems, the Fuzzy PID controllers is developed for controlling the speed, torque, and flux of an IM. The performances of the proposed FLC-based IM drives are investigated and compared to those obtained from the conventional proportional-integral (PI) controller-based drives both simulated at different dynamic operating conditions such as step change in command speed, load change, and increase in the rotor resistance. The comparative results show that the FLC is more robust, found to be a suitable replacement of the conventional PI controller for the high-performance industrial drive applications

---

This paper experimentally investigated the effects of electrical discharge machining processes parameters on fatigue resistance of 16MnCr5 alloy steel. 16MnCr5 alloy steels have good wear resistance. For this purpose, pulse current and pulse time have been considered as variables in the process. The selected EDM parameters were pulsed current (8, 16 and 32A) and pulse time (25, 100 and 400µs). Tests were conducted in full factorial mode and the R. R. Moore fatigue test machine was used to determine the fatigue life of components. The results show that by increasing the spark current and pulse duration 16MnCr5 alloy steel fatigue life is reduced. Respectively, the greatest resistance to fatigue achieved at current of 8A and pulse time of 25 microseconds and lowest resistance to fatigue achieved at pulse current of 32A and pulse time of 400 microseconds. Resistance to fatigue crack depends on cracks density on the surface of the workpiece and heat-affected zone, where the density of cracks increase resistance to fatigue will be reduced. Also in the specimens that have low resistance to fatigue, fatigue cracks are initiated from multiple points of the cross-section. It seems the reason for this phenomenon is the high surface roughness in the samples. EDM machining with high energy sparks can decrease the fatigue strength of 16MnCr5 by as much as factors of 3-5.

---

Spatial patterns are useful descriptors of the horizontal structure in a plant population and may change over time as the individual components of the population grow or die out. But, whether this is the case for desert woody annuals is largely unknown. In the present investigation, the variations in spatial patterns of Tribulus terrestris during different pulse events in semi-arid area of the Thar Desert, India, was quantified. Further ordination technique and path analysis were utilized to link the pattern and process of spatial distribution of T. terrestris. Dispersal indices like index of dispersal (I_D), index of clumping (I_C), Green’s Index, Lloyd’s mean crowding and Morisita’s index of dispersion (I_δ) revealed uniform distribution pattern during non-pulse events, showing intense competition among plants for limited resources. Kaiser-Meyer-Olkin (KMO) and Bartlett’s test of sphericity indicated the appropriate use of factor analysis and the significant relationships between variables. Principal Component Analysis (PCA) exhibited the significant correlation of the index of dispersion with the index of clumping and with the Lloyd index, while the Lloyd index correlated with the index of clumping and with the Morisita index. Path analysis suggested the association of soil organic carbon, nitrogen, and C/N ratio with the transition from clumped to uniform pattern. Further, lower soil phosphorus also supported the uniform distribution of this plant. Diversity indices like evenness and Simpson index are associated with uniform and clumped distribution patterns. Higher and intermediate level of percent cover and seed out-put of T. terrestris were also related to uniform and clumped patterns. Path analysis also indicated that salinity tolerance capacity of the species could be utilized for reclamation programme.

---

Investigation of frequency variations of acoustic impedance can play an important role in identification and optimization of a musical instrument. For a simple tube, the input acoustic impedance can be calculated by analytical methods; for complex geometry objects like wind instrument, however, it cannot be simply computed. Therefore, the impedance is measured for wind instruments. This paper is report of first experiment for measuring the input acoustic impedance of Ney (an Iranian woodwind instrument). For this purpose, a pulse reflectometer device was made. For assurance of correct operation of the reflectometer, in the first step, the input acoustic impedance of a three sections step tube was measured and the results were compared with calculated results using well known formula. the acoustic impedances of a Do-ney for various fingering in six case (from closed all holes to opened all holes) were measured. The results show that, contrary to what seen for flout, the frequencies of minima of the impedance curves have some discrepancies with the frequencies of corresponding playable notes. This may relate to the role of mouth of instrument player in producing tones of ney.

---

In this paper, the performance of a single-axis attitude control with pulse-width pulse-frequency (PWPF) modulation is enhanced using a modified proportional-integral-derivative (PID) controller for a rigid satellite with on-off thruster actuators. For this purpose, the well-known observer-based PID approach is utilized. The on-off thruster actuator is modeled with a constant delay followed by a second-order binomial transfer function. The modulator update frequency is limited to 40 Hz as an input to the on-off thruster actuators. In this study, the design criteria of pointing accuracy, overshoot of the attitude response, fuel consumption, and the number of thruster firings are considered for a step external disturbance (with different values). The parameters of the observer-based PID controller are tuned using parametric search method. Simulation results show that the fuel consumption and settling time of the observer-based approach are considerably decreased with respect to those of PID controller with PWPF modulator. Moreover, the overshoot of the observer-based approach is omitted. Finally, the robustness of the observer-based modified PID controller is investigated in presence of uncertainties in satellite moment of inertia and thrust level of on-off actuators.

---

The main objective of utilizing nozzles is to convert the chemical energy to kinetic energy producing thrust. Wide variety of parameters make significant impact on nozzle performance; one of which produces significant effect is back pressure or ambient pressure. Basically, a nozzle designed for a specific back pressure does not work properly when the engine is ascending. Consequently, designing of nozzles needs knowledge of full effect of back pressure on engine performance. In this study, numerical simulation of three solid propellant nozzles have been conducted in several flight conditions. In other words, simulations have done in some ambient pressures which represents specific flight altitudes. Numerical modeling has been conducted aiding commercial code FLUENT. k-ϵ RNG turbulence model has been used for calculating turbulence interactions with the flow. Mass flow rate, chemical species, and chamber temperature have been used as the inlet boundary conditions based on engine specifications. Numerical results show a reasonable accuracy in comparison with experimental measurements. Estimating nozzle thrust level as a function of altitude increment is the primary goal of this study. Furthermore, with the aid of this relation and a MATLAB code for computing average specific impulse, optimum expansion ratio can be achieved based on a specified mission.

---

In the present paper a DSMC solver is utilized to study the effects of wall heating/heater plates on performance parameters of microthruster systems. The solver uses local Knudsen number based on the gradient of flow properties to distinct the molecular and continuum region. This solver uses theory of characterisitcs for determination of inlet and outlet boundary conditions. Proper cell dimensions, number of particles per cell, and grid study are performed to guarantee the accuracy of simulations. Three typical micropropulsion systems are studied. All three systems have a microchannel and a converging-diverging micronozzle. First type is cold gas micropropulsion system, second type is a microthruster with wall heated channel, third type is microthruster with heater plates inside. The first type is considered as reference case and two other systems are compared with type1. It is obsereved that heating the walls in microthruster type2 accelerates the flow and increase the specific impulse of the system. In micropropulsion device type3, heater plates increase downstream temperature of convergent-divergent nozzle and also elevate the specific impulse. Due to considerable mass flow rate decrease of system type3, its thrust is decreased whereas mass flow rate of system type2 is not decreased as much as type3 and therefore the thrust of microthruster type2 is more than type1 and type3. Hence the second microprolusion system configuration has higher performance paratmeters in comparison with two other systems. It is also observed that increasing of wall temperature in microthruster type2 decrease the thrust and specific impulse sensitivity to temperature increase.