فهرست مطالب المیرا احمدی

The increasing process of overreaching in the development or decline of the athlete's performance acts as a moving that stops in the axis timely will improve the athlete's performance and achieve the goal. Therefore, the aim of the present study was investigated the effects of concurrent exercise physical and brain endurance on overreaching factors in active people.

Subjects included 20 active male and female physical education students (Mean ±SD; age: 22.3 ± 4.4 years, height: 177.56 ± 6.12 cm, BMI: 22± 4.5 kg/m2). Participants were divided into two groups of concurrent endurance and brain training (BET) and endurance training (ET), according to the results of the maximum oxygen consumption test. Physical exercise training was performed on cycle ergometer and brain training using computer with monitor on front of subjects during cycling. To analyze the results of the tests, Mix ANOVA. Significance level (P≤0.05) was considered.

The results showed that the maximum oxygen consumption after the training period, regardless of the type of activity, increased significantly (P = 0.00). Monitoring resting heart rate. POMS questionnaire indicators and resting cortisol levels did not show a significant increase indicating non-functional overreaching, respectively (P≤0/51). The rating of perceived exertion index was higher in the group that did physical endurance activity along with brain endurance training (P= 0/5).

These findings showed despite the increase stimulant to concurrent physical and brain endurance training did not cause non-functional overreaching and overtraining, but also based on the results of performance improvement, it can be said that the subject achieved functional overreaching and super compensation during the training period, which was able to experience progress.

Clayey soils usually have low bearing capacity, high compressibility, shrinkage and swell characteristics. Several methods have been adopted to improve the geotechnical properties of such soils. Soil stabilizing by chemical materials is one of the most common methods for treating fine grained soils. Lime has been used to improve some mechanical and plastic properties of fine grained soils since many years ego. In recent years some studies has been also carried out to investigate the influence of adding pozzolany materials on the geotechnical properties of lime – treated clayey soils. Geotechnical behavior of clayey soils depends on chemistry of pore fluid. When drinking water is used to provide the needed moisture of soil in the laboratory, it will be lead to incorrect interpretation in engineering properties of soil where specific water such as sea water is utilized. Therefore, if the undrinkable water has been used to provide soil moisture, it is necessary to examine the behavior characteristics of the materials by the same water. For example, presence of some sulphates in the soil stabilized with lime leads to problems such as reduction of strength and increase of swelling in clay. In this laboratory study, effect of sea water on strength of stabilized kaolinite has been investigated by conducting several unconfined compression tests. The specimens were prepared at fore percentage of lime and pozzolan (i. e. 0%, 1%, 3%, 5%) by weight of dry soil and distilled water and three saline water which were taken from Caspian Sea, Persian Gulf and Urmia Lake. for every combination, weight of each material was determined exactly based on the optimum moisture content and maximum dry density which is obtained from the standard proctor compaction test. Clay and lime and pozzolan were mixed in dry condition properly and then water was added gradually. Afterwards, the mixtures were kept in plastic bags for 24 hours. Weight of each specimen was determined in accordance with given specific volume and obtained maximum dry density from compaction test. This weight was divided into four portion and each portion was compacted in 20 mm layer in a PVC mold. The specimens were cured in a oven having a temperature about 35 C for 3, 7 and 14 days. After each curing time a extruder was used to remove the specimens from the molds with constant rate vertically to avoid bending and formation of tensile cracks. Then the specimens were immediately tested under strain controlled at constant loading rate of 1. 0 mm per minute, according to requirements of ASTM D 2166. For each combination, three specimens were examined to assure repeatability of results. The results of conducted experiments indicate that unconfined strength of samples without additives (lime and pozzolan) prepared by sea water are higher than specimens containing distilled water. For the samples containing Urmia lake water, the unconfined strength were higher than the other samples. Also, for the specimens in which additive has been used, the strength of the samples containing Caspian Sea and Persian Gulf water were more than that with distilled water and the strength of samples containing Urmia lake water was less because of differences in the concentration of salts existed in the water. Finally, the results show that water minerals are higher in Urmia lake water, Persian Gulf and Caspian Sea, respectively.