فهرست مطالب a keshavarz

The health of milk and its products is of great importance due to its high nutritional value. This nutrient medium is contaminated by microbial agents. Brucellosis is considered one of the most important zoonotic diseases and is endemic in the Middle East countries and has been reported in human and livestock populations in different parts of Iran. Brucellosis is an infectious bacterial disease caused by a microorganism of the genus Brucella and transmitted through unpasteurized milk and dairy products. The aim of the present study was to investigate the prevalence of contamination of milk and traditional dairy products with Brucella bacteria by PCR method, Mamasani district, Fars province, south of Iran.

In the present cross-sectional descriptive study conducted in 2021, 200 samples of traditional dairy products including 50 samples of raw milk, 50 samples of yogurt, 50 samples of cheese and 50 samples of butter from livestock farms in rural areas and inner-city shops of Mamasani district were collected and transferred to the microbiology laboratory. In order to identify the possible type of Brucella bacteria in the samples, the culture medium containing the supplement was used to prevent the growth of other pathogens. DNA of samples was extracted by DNp kit. In order to optimize the PCR test, the DNA sample was extracted from the standard strain of bacteria by boiling method and (cat: DN 811530) DNG. In each reaction, template DNA, primers (Bru and Low Bru Up), magnesium chloride, dNT and Taq DNA polymerase enzyme were used according to the instructions. The second step reaction was optimized with the same values. In the second step, instead of template DNA, the product of the first round was used. Second stage primers include Bru Up, Bru In primers. The collected data were analyzed using SPSS software and chi-square statistical test.

The results of the present study indicated that 1.86%, 2.8%, 0.3% and 0% of raw milk, cheese, yogurt and butter samples were infected with Brucella melitensis bacteria, respectively. The optimized PCR test had a very high specificity, as a result it did not react with any of the studied DNAs except Brucella DNA.

Although contact with animals and products infected with Brucella bacteria are known as the most important factors of brucellosis, but then again the climatic conditions and the type of animal farming and the eating behavior of the people in the way of using animal products as well as the pathogen species in each geographical area are the factors that determine the pattern of the disease. It displays the incidence of disease in different societies. The obtained results indicated that despite the measures taken to prevent Brucellosis disease, there was still a possibility of contamination of dairy products with Brucella bacteria.

Acceptance and commitment therapy has a positive effect on improving emotional components and increasing the quality of life in students. This study aimed to determine the effectiveness of acceptance and commitment training on academic emotions in high school female students.

This is a quasi-experimental study with a pre-test, post-test, and control group. The statistical population of the present study consisted of all high school female students in the 4th district schools of Mashhad in the academic year of 2018-2019. To select the sample, the multi-stage cluster random sampling method was used, and two classes (with a total of 40 people) were randomly assigned to experimental and control groups. For the experimental group, eight 90-minute sessions of acceptance and commitment training were performed, and the control group did not receive any training. The academic achievement emotions questionnaire of Pekran was used to collect data; then, the multivariate analysis of covariance (MANCOVA) test, independent t-test, and chi-square test were used to analyze the data.

Mean and standard deviation in the pre-test (post-test) of the experimental group for the studied components in class were as following anger: 19.03±6.04 (17.31±6.18), anxiety: 33.04±8.98 (31.12±10.80), shame: 27.77±7.52 (24.68±8.81), disappointment: 20.53±7.76 (18.96±8.04), and fatigue: 28.86±9.90 (25.69±9.07); no significant change was observed in the control group. The results showed that the effect of acceptance and commitment-based education on students' academic excitement was statistically significant (p<0.001), compared with the control group.

Considering the reduction effectiveness of acceptance and commitment education on negative academic emotions, it is recommended to be used in educating students.

Diagnosing tire defects is an important part of the tire inspection automation process. Various solutions have been proposed to diagnose tire defects using tissue and local information. These solutions are very important in identifying various types of tire quality control defects for tire manufacturing companies. Due to the fact that the examination of X-ray images by the operator is a time-consuming and costly process, so the use of machine vision and machine learning is an important issue in this industry. In this paper, a new solution to detect tire defects in X-ray images based on image processing techniques and using the method of extracting image texture properties is presented. In the proposed method, local binary pattern )LBP) techniques are used to extract the defect properties. In order to evaluate the proposed solution, the tire data set was prepared with X-ray images, which by applying the proposed algorithm on this set, a good accuracy in fault diagnosis was obtained, which also has a desirable performance.

Flow in river bends is associated with generation of secondary flows that leads to a rather complicated flow pattern around bridge piers located in the bend. In this study, the flow patterns around rectangular and oblong piers models with collar located at the 90o angle of a 180-degree sharp bend in an experimental plume were investigated. The 3D flow velocity data were collected using a Vectrino velocimeter. The experimental results indicated that the presence of the rectangular pier caused more intense deviation of the streamlines towards the outer bank of the bend. Furthermore, installation of the oblong pier, the maximum secondary flow power and angular velocity were decreased, respectively, by 35% and 45% in comparison with the installation of the rectangular pier. In addition, it was found that the maximum turbulence kinetic energy around the two piers was not significantly different, but by installing the rectangular pier, a region with high values of turbulence kinetic energy is formed at 90° near the inner bank. Also, installation of oblong pier reduces the values of shear stress in comparison with the use of the rectangular pier.

Lateral spreading is one of the most significant destructive and catastrophic phenomena associated with liquefaction caused by earthquake and can impose very serious damages to structures and engineering facilities. The aim of this study is to evaluate liquefaction induced lateral spreading and finding new relations using gene expression programming (GEP) that is a new and developed generation of genetic algorithms approaches. Since there are complicated, nonlinear and higher order relationships between many factors affecting the lateral spreading, GEP is assumed to be capable of finding complex and accurate relationships between these factors. This study includes three main stages: (i) compilation of available database (484 data), (ii) dividing data into training and testing categories, and (iii) building new models and propose new relationships to predict ground displacement in free face, gentle slope and general ground conditions. The results of modeling each of the different ground conditions are presented in the form of mathematical equations. At the end, the final GEP models for 3 different cases of ground conditions are compared with multiple linear regression (MLR) and other published models. The statistical parameters indicate the higher accuracy of the GEP models over other relations.

Hydatid disease is a common health problem in developing countries. The liver and lungs are the most common organs affected by this infection. Hydatid cyst is very rare in the inguinal area. The aim of this case report was to introduce a patient with multiple hydatid cysts in the right inguinal area who developed symptoms of inguinal hernia.

CASE REPORT: 

The patient is a 92-year-old man who was referred to Imam Reza Hospital in Mashhad due to pain, swelling and redness in the right inguinal area. The patient s blood tests showed an increase in neutrophils, and a decrease in eosinophils, basophil and monocyte. Ultrasound examinations of the patient revealed right inguinal hernia and hydatid cysts in the liver, abdomen and pelvic cavity. Finally, the patient was operated with a diagnosis of incarcerated inguinal hernia. During the operation, multiple cysts were observed in the inguinal area; the cysts were removed and sent to pathology. Pathological findings confirmed the presence of hydatid cyst. After 2 days, the patient was discharged in relatively good general condition and with albendazole (400 mg) twice daily for 6 months. At the end of the treatment period, no signs of recurrence of hydatid cyst were observed in the patient.

According to the cases reported in patients diagnosed with hydatid cyst with inguinal pain, the possibility of migration or hernia of hydatid cyst should be considered, because knowing its presence is useful for preoperative planning and reduction of complications.

Obesity influences the mental health of children and teens improperly in addition to its transparent negative effects on health. The objective of this research is studying the effect of obesity and overweight on the elements of emotional intelligence and IQ of students in Districts 1 and 19 of Tehran City. The type and nature of this research are descriptive-analytical and applied based on its objectives, respectively. The data collection method was surveying and hypothesis test. Statistical population of this research includes 184 students from Districts 1 and 19 of Tehran City who were selected by convenience random quota sampling method. The results of multiple regression did not show a significant relationship between the anthropometric indexes of emotional intelligence and IQ of children. However, a significant, weak, and reverse relationship was observed between their weight and the total score of emotional intelligence (correlation coefficient= -0.134 and sig. level = 0.044). There were reverse correlations between weight for age and condition of emotional intelligence evaluation, and between weight for age and total score of emotional intelligences (correlation coefficient= -0.244 and sig. level = 0.026 and correlation coefficient= -0.214 and sig. level = 0.044). In addition, a significant, weak, and reverse correlation was seen between age and emotional intelligence (correlation coefficient= -0.144 and sig. level = 0.033). Based on this research’s findings, no strong and significant relationship was observed between the anthropometric indexes and IQ or emotional intelligence of the studied students. Further studies in larger scopes are recommended.

Detection and classification of Marine vessels based on their acoustic radiated noise is an important part of sonar systems. I this paper passive sonar targets classification algorithms is reviewed and a new algorithm is proposed. LDA feature extraction algorithm and Fusion of short time Fourier and timbre features is used in proposed algorithm which is called STFTLDA-Timb. Extracted features of proposed algorithm, are highly discriminant and classification accuracy of proposed algorithm is 8.45% better than STFT based classification algorithm. Obtained results of real data passive sonar classification show that classification accuracy of proposed algorithm is better than some common classification algorithms like statistical classifiers, neural networks and Ensemble Learning algorithms.

Although, the Stirling engine (SE) was invented many years ago, the investigation on SE is still interesting due to variety of energy resources can be applied to power it (solar energy, fossil fuel, biomass and geothermal energy). In this paper, the thermodynamic cycle of SE is analyzed by employing a new analytical model and a new method is presented to evaluate output power and efficiency of real engines. Using the correcting functions; represent more accurate results for known Schmidt equations respect to adiabatic model. So without need to employing numerical methods and iterative solver programs, analogous results with accuracy and correctness of open-form solution-adiabatic method is obtained. The modeling of results of two methods is done by Non-linear Multiple Regression and new equations based on Schmidt equations with new correctness factors is presented. The correctness factors are function of structural and operational characteristics of engine.  Moreover, available output data of GPU-3 SE was compared. These comparisons show good agreement, indicating that the model is an appropriate method for modeling of SE outputs.

Turbocharging an engine boosts its power by increasing the amount of input air. This task is accomplished by using the exhaust gas to power a turbine which is engaged with a compressor. The Variable Geometry Turbocharger, VGT is a unique turbocharger that the diffuser vane angle can be changed over a wide range of positions. The mathematics of turbomachinery flow analysis is intensive and uses iterative methods. Most of the flow analyses in the area of turbochargers are either experimental or numerical. Three-dimensional Computational Fluid Dynamics (CFD), two-dimensional multiple streamline and one dimensional mean line is the three primary numerically available methods. In this paper a mean line method has been used for predicting the performance of a centrifugal compressor with variable diffuser vane angle position at subcritical Mach numbers. The calculation is based on common thermodynamic and aerodynamic principles, and empirical correlations for losses in a mean line analyses. The model calculates the velocities, pressures, temperatures, pressure losses, work consumption, and efficiencies for a specified set of turbocharger geometry, atmospheric conditions, rotational speed, and fluid mass flow rate. The obtained numerical results are validated with the in house measured experimental data and good agreement observed. The purpose for compressor model analysis is to generate overall characteristic map and identify the impact of the diffuser vane angles on the performance. The overall characteristic map is generated by this method demonstrate very good agreement and the effect of variable vane angle in pressure ratio and operating range observed.