The depletion of oxygen in a reactive stockpile that undergoes self-ignition process due to low-temperature oxidation reaction, is investigated in this paper. A reactive stockpile is the one whose materials contain carbon or hydrocarbon compounds that react readily with the oxygen trapped within the stockpile. The combustion process is modelled in a two-step reactive slab, that loses heat to the surrounding by convection. The process of combustion is so complicated and therefore, the mass transfer partial differential equation governing the problem cannot be solved exactly, but a numerical method is applicable. In this case, the equation was solved using Finite Difference Method (FDM), and Maple software was used to derive the solutions. The results plotted indicate that parameters like the oxygen Biot number help to retain the oxygen, whereas parameters such as the reaction rate enhance the depletion of oxygen.
This study introduces a new MVP determination method for basketball. MVP determination methods used in important leagues such as NBA or Euroleague take into consideration only the points, assists or rebounds of the players and these statistics ignore the percentages or rates of the team in general. Unlike other methods, the method proposed here includes both the players’ individual percentages and also percentages within the team. Fuzzy clustering analyzing was used for calculation and determination for the proposed method. Application results are compared to other scales used in NBA and Euroleague. Results showed that the proposed method can be used as an alternative method for MVP calculations.
The purpose of this study is to compare the anaerobic power values and sprint performances of football players playing in different positions and to evaluate the association between these. A total of 40 male football players with a mean age of 18.5±2.26 participated in the study voluntarily. First, football players were grouped in four according to their positions (5 goalkeepers, 10 defenders, 17 midfielders and 8 forwards) and their ages, years in sport, weights and heights were found. 20 m, 30 m and 45.72 m (50 yard) sprint tests, vertical jump and Wingate anaerobic power tests were performed on the football players. One-Way Anova was used to determine the differences between groups while Tukey multiple comparison test was used to determine between which groups the differences were. Pearson correlation analysis was used to determine the associations between the variables. While no significant difference was found between groups in terms of age, years in sport, height, vertical jump and peak power, mean power, minimum power, fatigue index measurement parameters of Wingate test (p>0.05); significant differences were found in weight and means of 20 m, 30 m and 45.72 meter (50 yard) sprint tests (p<0.05). On the other hand, statistically significant positive association was found between 20 m, 30 m and 50 yard sprint test and statistically significant negative association was found between sprint test and vertical jump test results (p<0.01). In addition, a negative association was also found between 30 m sprint and peak power values, one of the Wingate anaerobic power test outputs (p<0.05).\n\nThe results of this study showed that there was no statistical difference between the vertical jump and Wingate anaerobic power test parameters of the football players in terms of their positions and that only goalkeepers showed a lower performance in terms of sprint time when compared with the other positions. Thus, it can be said that players of all positions have similar physical characteristics. In addition, the negative association found between the sprint values and vertical jump values brings to mind that vertical jump trainings can be used to improve the ability of speed.
This study aimed to evaluate citizens’ satisfaction with the mechanized solid waste collection system at different parts of Tehran, the capital of Iran. For this purpose, a descriptive survey methodology was adopted in this study. The statistical population was composed of the citizens of District 21 of Tehran municipality in 2013. Using Cochran’s formula, 400 citizens were selected as a sample size to fill in the prepared questionnaires. Sampling was also determined in proportional to the solid waste volume in triple regions of Districts 21. Results showed that the average citizens’ satisfaction at the moderate had a significance difference (P<0.0001). However, there was no significant difference between the average satisfaction of men and women (17 %) and satisfaction of citizens at different regions of District 21 ( 82 %). Moreover, a meaningful correlation was observed between the citizens’ satisfaction and time, noise pollution, cleanliness of the neighborhood, locations of waste tanks and traffic.
The purpose of this research is to determine the motivational factors leading individuals to visit Village coffee stalls, Cafes in city center and Countryman coffee stalls. There are totally 300 participants in three group each has 100 participants. The questionaire form includes two parts, first demographics variables, seconds the motivational factors which has affects participants to go these localities. In the process of assessing data the descriptive statistic methods and One-way ANOVA test have been used and results have been assessed according to significant level 0.05 and 0.01. A five-point Likert scale was used and the range covers “1=strongly disagree” to “5=strongly agree”.\n\nAs a result of this study, it can be concluded that the participants living in city and have possibilities to go to cafes have recreational advantage, and they spend more money and spent much more time for their recreational life than the others. The participants prefer inactive leisure activities as watching TV, resting at home and family togetherness; the reasons for going to cafes were friend-focused like being with friends, eating/drinking/playing something with them. But in village there was lack of recreational alternatives and the men have to go the village coffee stall, and prefer inactive leisure.