m. rezazadeh

Hardware-In-the-Loop (HIL) is a kind of simulation in which an actual component of a closed-loop control system is tested within computer-based real-time simulation of the rest of the system. In a conventional HIL simulation, the hardware is an Electronic Control Unit (ECU) in which electronic control signals are communicated between the hardware and the software. But, HIL simulation of a mechanical component, within a closed-loop control system, requires additional sensors and actuators named transfer systems. The transfer systems are used to connect the software and hardware parts. The HIL simulation can achieve unstable behavior or inaccurate results due to unwanted time-delay dynamic of the transfer systems. In this paper, a test bench is implemented for the hardware-in-the-loop simulation of the fuel control unit (FCU) of a gas turbine engine. The FCU is an electro-hydraulic actuator of the fuel control system. In a real engine, the FCU contains a miniature gear-type liquid-fuel pump which is driven at a fraction of the engine rotor speed mechanically by gears. In the HIL simulation, the engine is simulated numerically and an electric motor is employed to drive the pump of the FCU. The real-time simulation of the gas turbine engine thermodynamic model is implemented on an industrial personal computer with an input/output board in connection with the electro-hydraulic system. There is time-delay in the forward path of the fuel control system due to the use of flowmeter for measuring the outlet flow rate of the FCU in HIL simulation. According to extensive experimental works, the AC motor’s lag dynamics has no considerable effect on the HIL testing, and the flowmeter is the only additional transfer system of which the dynamic effect needs to be mitigated. The results show instability of the hardware-in-the-loop simulation due to unwanted time-delay of the flowmeter. Therefore, a model-based predictor is designed for time-delay compensation of the flowmeter. The consistency of the experimental real-time simulation and off-line simulation shows the applicability of the presented method for mitigating the effect of unwanted dynamic of the transfer system in the HIL simulation.

This paper analyzes the temperature and rainfall data series collected by Dezful stations in a 31-year period (1986 to 2017) in order to evaluate the magnitude of these changes statistically and to forecast their behavior for the 2018-2020 period using SARIMA models. The Mann-Kendall test was used to analyze climate change in the past and future. The results show that rainfall has a decreasing trend and minimum and maximum temperatures have increasing trends. The results of the SARIMA model show that the coefficient of correlation (r) between the observed and forecasted values was 0.95, 0.9 and 0.58 for rainfall, minimum temperature, and maximum temperature and the mean absolute error (MAE) was 1.24, 1.45 and 20.24 for them, respectively. The results of trend analysis reveal that Mann-Kendall's statistics (Z-value) for the data on minimum temperature, maximum temperature and rainfall are 3.81, 1.78 and -2.71, respectively implying a descending trend for temperature and an ascending trend for rainfall. Minimum and maximum temperatures have been rising at the rates of 0.07 and 0.04°C per year, but they are forecasted to have increased by 0.084 and 0.06°C by 2020, respectively. The rate of rainfall variation will decrease from 4.4 mm to 4.85 mm per year. Improved understanding of recent climate change helps to elucidate the impacts and vulnerability of the local population in order to implement the most appropriate practices to cope with climate change and manage the changing situation in a better way.

Centrifugal pumps are used in the various industries as one of the important components responsible for the movement of the incompressible fluids. In this paper, the fluid flow of water in a centrifugal pump is simulated with a three-dimensional numerical solution. The operating fluid is considered to be incompressible and in steady state condition. The numerical solution is performed using a ANSYSY 16.0 software. The provided results are validated by the pump manufacturer's characteristic curves. One of the effective factors in increasing the efficiency of the centrifugal pump impeller is the change in radial distribution of surface centers of two-dimensional profiles. In this research, these changes have been done in tangential direction. The change of the lean angle in two modes of fixed hub and fixed shroud has been performed. The simulation of the flow field for various lean angles showed that the creation of a negative lean angle has been increased the efficency by 0.51% for the fixed hub and 1.34% for the fixed shroud.

Amorphous semiconductors are materials with a brilliant prospect for a wide range of optical applications like solar cells, optical sensors, optical devices, and memories. The purpose of the present research was to study the semiconducting optical properties of SiO2-Al2O3-CaF2 and SiO2-Al2O3-BaF2 oxyfluoride glassy systems, which has been rarely studied from this point of view. The suitable compositions in the mentioned systems were chosen and melted in covered alumina crucibles at 1450˚C. Afterward, preheated stainless steel molds were used to shape the molten glasses. The absence of any crystallization peak in the XRD results indicated that the samples were amorphous. DTA patterns showed that the crystallization temperature of the fluoride phase is 693˚C for the glass containing BaF2 (SAB), which is higher than the peak temperature (684˚C) for the glass with CaF2 (SAC). DTA results were in accordance with density measurements, i. e., the density of the glass SAB (3.85 g.cm-3) was higher than the glass SAC (2.70g.cm-3). That is to say, BaF2 presented a more continuous structure with lower amounts of dangling bonds. According to the UV- Vis spectra, sample SAB had higher absorption and smaller bandgap of the glass SAB (with a direct bandgap of 2.90 eV and indirect bandgap of 3.40 eV) indicated that it has better semiconducting behavior than sample SAC (with a direct bandgap of 3.07 eV and indirect bandgap of 3.60 eV). This increment of the semiconducting behavior is attributed to the more continuous structure of the glass SAB. Urbach energy, which is an indicator of disorder degree of structure, was 0.20 and 0.32eV for SAB and SAC, respectively. Therefore, the lower Urbach energy of SAB glass confirmed the higher structure order of it.

Nowadays, oxyfluoride glasses have received much attention from photonic researchers as they benefit from the advantages of both oxide and fluoride glasses (low phonon energy in parallel with high mechanical and chemical durability). The purppose of this paper was to study the different glass compositions in SiO2-Al2O3-K2O-BaF2 system and investigate the BaF2 effects on their crystallization behavior and structure. Therefore, various chemical compositions with different amounts of BaF2 (20, 30, and 40mol%) were chosen and melted in alumina crucibles at 1450˚C. The sample could not melt with the lowest percentage of BaF2. On the other hand, the glass composition containing the highest amount of BaF2 was not able to show high transparency due to the phase separation that occurred in it. Finally, the sample with a 30mole ratio of BaF2 was chosen as the optimized sample due to the favorable transparency. XRD patterns showed that the samples were amorphous and it somehow proved the low transparency in the presence of higher amounts of BaF2 arose from phase separation than the unwanted crystallization. According to the DTA results, the crystallization peak of the fluoride phase decreased from 693˚C to 678˚C by increasing the content of BaF2. FT-IR spectra approved the oxyfluoride structure of the glasses. Higher BaF2 content increased the absorption of peaks in FT-IR spectra since it results in a more discontinuous structure. Fluorine loss was higher for the glass containing the highest amount of BaF2 due to the lower amount of Al2O3 in its composition.

In this study, modeling of hydrogen, nitrogen, carbon monoxide, methane and carbon dioxide sorption on UTSA-16 framework extrudates in the pressure swing adsorption process was carried out. The pure gas adsorption of these gases at the pressure range (0 to 80) bars at (298, 313, and 338) K have also been measured in a fixed bed. Langmuir, Toth, Sips, UNILAN, Virial and Dubinin-Astakhov adsorption models were tested on adsorption data to estimate the sorption capacity, intensity and energy. Cuckoo search optimization algorithm was used for solving the problem to estimate the parameters of adsorption models. The results show that Langmuir isotherm provided the best fit to the equilibrium data with a square of residuals (Fobj) of 0.022, 0.2670, 0.4840, 0.1813 and 1.9619 for hydrogen, nitrogen, carbon monoxide, methane and carbon dioxide respectively. There was a good agreement between the predicted theoretical breakthrough curves and the experimental results with Langmuir, Dubinin-Astakhov, Sips, Toth and UNILAN, respectively.

The Chalcogenide glasses were fabricated by melting and quenching techniques in the Se-Ge system at the presence of 1mol% Ga and 3, 5, and 7mol% Sn. Differential Scanning Calorimetry (DSC) analysis was conducted to extract the heat treatment of the samples. Fourier Transform Infrared (FTIR) spectroscopy analysis was also performed in a range of 2-16µm. The Glass samples were heat-treated at 450°C for 1-10h. The precipitated nanoparticles were observed using a Field Emission Scanning Electron Microscope (FESEM). The crystal size was reported in the range of 100-1000nm. The precipitated phases were identified using X-ray Diffraction (XRD) analysis on Glass-Ceramics powder. The increase in hardness of the Glass-Ceramics was reported in the range of 200-250Kg.mm-2.

Kawasaki disease happens mostly in children less than 5 years of age and presents itself as an acute and self-limiting disease with world wide spread. One of the important consequences of this disease، if undetected، is the cardiovascular morbidity that caused by the disease. The aim of this study was to determine demog-raphic findings about cardiovascular afflict-tions in Kawasaki patients.

The study was a descriptive and retrospective study and data were provided through reviewing of medi-cal records of Kawasaki patients who had been hospitalized between 1998 to 2003 at Imam Hossein and Mofid Children''s Hosp-ital.

In the aforementioned period، 97 patients with Kawasaki disease were hospit-alized in two centers، 65 (67. 1%) males and 32 (32. 9%) female). 75 (77. 3%) patients we-re under the age of 5 years and 22 (22. 7%) were older than 5 years. 32 (32. 9%) patients had one or more heart involvements. The number of patients with heart involvements were 20 males (62. 5%) and 12 females (37. 5%). The most heart involvements were pericardial effusion (23. 7%) and the least heart involvements were coronary artery dilation and aortic stenosis (2%). Discussion &

Timely diagn-osis and preventive treatment can prevent the complications of Kawasaki disease. The cardiac rehabilitation program could impro-ve the life quality of the patients

One of the important and strategic factors in economic and social development of each nation and government is human resource development and human power improvement. Lack of movement not only stops growing but also causes depression, behavioral disorders and loss of passion and happiness in life. Sport activity is a proper and efficient strategy to provide physical and psychological health. Today, experts view sport activities as an effective strategy to create calmness and to reduce stress. For this purpose, the current study examined the factors relevant to participation and lack of participation of some employees in sport activities. The research method was survey and field. The research population involved all employees in Baqiyatallah University of Medical Sciences, and a sample of 385 subjects was selected through stratified random sampling method. To analyze research data, descriptive statistics and an inferential statistics such as Pearson’s correlation test, as well as analysis of variance test and independent t test were applied. The results showed that lack of motivation, stress, psychasthenia, physical disability and physical limitations were personal restrictive factors; lack of time, much responsibilities, lack of facilities andequipment were found to be organizational restrictive factors among employees of Baqiyatallah University that prevented them from participating in sport activities. In addition, there was no significant relationship between five personality factors and the rate of participating in sport activity except for extroversion factor. It seems that there exists various motivational factors for university employees to participate in sport activities and their participation can increase through elimination of the restrictive factors.

Superinfection of hepatitis A in chronic hepatitis B and C may worsen the course of disease. This study attempted to study frequency of hepatitis A virus antibodies in patients with hepatitis B and hepatitis C.

115 hepatitis C and 56 hepatitis B patients who visited the Hepatitis Association of Hamedan province during 2004-2005 were enrolled. Hepatitis A virus antibodies (IgM, IgG) by ELISA, WBC, hemoglobin, platelet, AST and ALT were evaluated.

32 patients with hepatitis B and 39 patients with hepatitis C refused the study. In 71 (85.5%) patients with hepatitis B, IgG-HAV-Ab and in one patient IgM-HAV-Ab was detected. 36 (92.3%) patients with hepatitis C had IgG-anti-HAV.

Due to high frequency of HAV Ab, it is preferable to evaluate patients with hepatitis B and C for HAV-Ab instead of vaccination of all patients. .

Glucocorticoid treatment in babies to prevent chronic long disease causes myocardial hypertrophy and increased myocardial protein content. Although these changes are thought to be transient, there is evidence that dexamethasone (DEX) induces permanent myocardial abnormalities as well. In this study, we investigated the ultrastructural changes of cardiomyocytes during the early period of DEX treatment. Pup rats (age: 5 days, number: 24) were treated with intraperitoneal injection of DEX at doses of 0.5, 0.3 and 0.1mg/kg). Control pups were treated with saline. At 1, 3 and 7 days after injection, the rats were killed. The anatomical parameters were body weight (BW) and heart weight (HW). Our data showed a significant decrease of body weight and heart weight in the 3 and 7-day experimental groups after the last injection. Histological study showed the presence of condensed cardiocytes. Ultrastructural studies showed evidence of degenerative changes in mitochondria and myofibrils and chromatin clumping after the 1st day of DEX injection. In the 3 and 7-day experimental groups, these changes were more serious, and chromatin condensation of cardiomyocytes occurred. Our study showed that neonatal DEX treatment in rat pups causes a decrease in body weight and heart weight during the early period of injection. Histological studies revealed degenerative changes of cardiomyocytes in the experimental pup rats. Ultrastructural studies showed that the type of cell death may be apoptosis.