فهرست مطالب r. shabani

Engine mounts are designed to hold the engine and isolate its vibration from the chassis of the vehicle. For optimum system performance, the mount must have high dynamic stiffness in the low-frequency range and low dynamic stiffness in the high-frequency range. As the conventional elastomeric mounts fail to satisfy such requirements due to their frequency-invariant behavior, the hydraulic engine mounts have been proposed, which provide appropriate dynamic stiffness employing two fluid-containing chambers. These two chambers are connected through a high-damped pass named inertia track and a floating plate named decoupler. In this paper, the low-frequency range response of a hydraulic engine mount has been studied using a discrete model. The effect of its parameters on the dynamic stiffness, damping ratio, and transmissibility of the mount is discussed. It is shown that increase in dynamic stiffness and damping ratio of the hydraulic engine mount is in contradiction with the decrease in its transmissibility. Hence, a multi-objective non-dominated sorting genetic algorithm has been used to achieve the desired results and the corresponding Pareto front is plotted. It is observed that upper chamber compliance and the effective area of the mount are the most dominant parameters in the optimization procedure. Also, a penalty function is used to transfer the maximum transmissibility out of the engine operation frequency range. Finally, the optimization results for transmissibility, damping ratio, and dynamic stiffness are presented for three series of parameters. It can be concluded that on the limit points of the Pareto front, which correspond to the one-objective optimization, the professed objective is optimized, but on the contradictory objective, no improvement is observed. There are points on the Pareto front where all the three objectives are optimized simultaneously. Therefore, as the transmissibility decreases and its maximum value falls out of the operating frequency range, the damping ratio and dynamic stiffness are increased.

Breast cancer survivors are in danger of elevated insulin resistance and hyperglycemia due to chemotherapy and surgery side effects and inactivity. Exercise can improve glucose homeostasis. This study aimed to assess the effect of twelve weeks concurrent Yoga and Pilates training on glucose homeostasis and insulin resistance in breast cancer survivors.

This randomized clinical trial was performed on 24 breast cancer survivors in Rasht, Iran, in 2020. The participants were randomly devided into control or case groups. The case group (n=13) underwent 12 weeks of concurrent Yoga and Pilates exercise training, 3 sessions per week.  The control group (n=11) did their routine daily activities. Weight, body mass index (BMI), fasting blood sugar (FBS), glycosylated hemoglobin (HbA1C) and insulin resistance (HOMA-IR) were measured before and after 12 weeks of exercise in either groups. Data was analyzed using multivariate covariance test and non-parametric Mann-Whitney U test.

Twelve-week concurrent exercise caused significant decrease in weight (p=0.002), BMI (p=0.002) and HbA1C (p=0.050). However, there was no significant effect on FBS or HOMA-IR (p>0.05).

According to the results of the current study which showed the positive effect of this exercise program on weight control and glucose homeostasis in breast cancer survivors, concurrent Yoga and Pilates training can probably be a good exercise program in these patients.

Obesity and overweight are widely expending in worldwide and containing a wide range of diseases, such as glucose homeostasis disorders. Green coffee and exercise are as suitable treatment options for this condition.

The aim was to evaluate the simultaneous effects of green coffee consumption and combine training on body composition and glucose homeostasis in overweight and obese women.

26 overweight and obese women were randomly divided into three green coffee (n=9), combined training (n=10) and green coffee - combined training (n=7) groups. Green coffee powder was consumed daily as two 125 mg per day before lunch and dinner. Combine training was contain of six weeks, four session per week of progressive endurance- strength training. Insulin, fast blood suger and HOMA and body composition factors were measured before and after the end of interventions. 

Weight, body mass index (BMI), waist circumference, hip circumference, waist to hip ratio (WHR), fat percent, insulin and HOMA levels were significantly decrease in all three groups that the reduction for all variables except waist circumference, WHR, insulin and HOMA were higher in green coffee- combine training group than two other groups (P<0.05). Blood glucose changes was not significant in any groups (P>0.05).

Results indicated that maybe both green coffee and combine training are effective for improve body composition,  insulin and HOMA levels and simultaneous usage of green coffee combine with combine training have synergistic effects on improving body composition.

High intensitystrength and endurance training can increase exercise capacity. The aim of this study was to describe the effect of high intensity strength and endurance training on body fat index, glucose homeostasis and serum leptin of 15 to 20 year old Taekwondo players boy. Of the eligible volunteers in the study, 20 taekwondo players aged 15 to 20 were selected as the research sample. The subjects were randomly divided into two groups: moderate-intensity resistance-endurance training (the first group, the mean age was 17.77 ± 2.26 years) and high intensity (second group, 16.90 ± 1.72 years). The first group, , had moderate intensity and endurance training for 95 minutes, and the second group performed high intensity training for 80 minutes. Along with the conventional taekwondo exercises Before and after 8 weeks training, body fat index, glucose hemeostasis and serum leptin were assessed. For data analysis, dependent t-test and independent t- test were used. P<0.05 was considered significant. Compared with the pre-test, in the second group a significant decrease was observed in the body fat percentage, insulin and insulin resistance levels. Leptin and FBS significantly decreased after exercise in both groups. The Comparison between groups showed only significant difference in body fat percentage (P=0.03).. High intensity strength and endurance training in athletes can potentially lead to significant reduction in subcutaneous fat. Decreased serum leptin and glucose levels and improved insulin sensitivity can improve the taekwondo lpayers performance