In this research the effects of formulation and the amount of triallylcyanorate (TAC) as coupling agent on peroxide vulcanization and mechanical properties of the participated amorphous silica filled EPDM elastomer are investigated. The results of curing process and measuring the mechanical properties (hardness, modulus, tensile strength, elongation-at-break, abrasion, resilience and Mooney viscosity) of compounds showed that silica accounts for mechanical properties improvement and TAC increases Mooney scorch time and it reduces optimum curing time, therefore it prevents compound scorching. In addition, results showed that TAC improved rubber-filler interaction and apparent crosslink density, which reflected on mechanical properties under study.

Background: The veterans and imperfectives can participate in various physical and mental activities and be beneficial of its advantages to increase their quality of life.Purpose: The present study aimed to compare the quality of life between two groups of participants, veterans and imperfectives and non-participant veterans and imperfectives in Sport activities.Method: The research method was descriptive and survey. The statistical population included all veterans and imperfectives in Tehran. The sample of study consisted of 290 veterans and imperfectives who were selected by random sampling method (136 active veterans and imperfectives and 154 passive veterans and imperfectives). The research instruments were the demographic questionnaire and the quality of life questionnaire. The validity of questionnaire was approved by sport management instructors and the reliability was calculated as 0.89 by Chronbach’s alpha. Collected data were analyzed through descriptive and inferential methods such as K-S test and T test for independent groups.Findings: The results showed that the quality of life of disabled veterans and imperfectives who participated in the Sport is generally higher than the quality of life of the veterans and imperfectives who are non-participated in sports. Regarding the amount of T test (3.12) this variance is significant.Discussion and Conclusion: In general due to the physical condition and its impact on quality of life of veterans and imperfectives and according to the results of this study too, physical activity and exercise seems to be one of the best ways to improve the quality of life and morale of these people.

In this study, the performance of direct absorption solar collector is experimentally investigated using Fe3O4/Silica hybrid nanofluid based on deionized water. First, stability of prepared nanofluids is considered using spectral absorbency method. Then, spectrophotometry method is used for measuring optical properties of nanofluids. A prototype of this new type of collector was built with applicability for solar water heating systems. The procedure of EN 12975-2 standard was used for testing the thermal performance of the collector. Results show that collector efficiency is enhanced by nanofluid concentration, so that collector maximum efficiency is 73.9%, 79.8% and 83.7%using nanofluid with concentration of 500 ppm, 1000 ppm and 2000 ppm, respec/tively. This vaule is 63% using the base fluid as working fluid. Regarding very low volume fractions of nanofluids used in direct absorption solar collectors, the viscosity of the base fluid experience insignificant increase, therefore, pumping power will not increase significsantly. Such increase in efficiency show that direct absorption solar collector performance using hybrid nanofluid is much better than that of using the water at the same operating conditions. Application of stable hybrid nanofluid results in higher conversion efficiency of solar energy to useful energy.

Introduction: Dimensional changes in acrylic patterns during laboratory process to fabricate casting are an important issue which could lead to many clinical consequences. Microleakage, lack of retention and fitness are few of problems which could be predicted in the case of dimensional changes in acrylic patterns. So, investigating the factors which could minimize the dimensional change is necessary. This study compares how different proportions of silica-sol and distilled water affect the dimensional changes in castings.Methods: This study was an experimental study wherein 30 specimens of acrylic patterns (Duralay) with similar dimensions were prepared and equally divided in five different groups and studied. Using extensiometer digital machine, the acrylic patterns were measured at three portions (length, coronal diameter and apical diameter) with accuracy of 10 microns.Results: 1- The mean average of casting post length compared to changed acrylic patterns was statistically significant in pure distilled water group only.2- The mean average of changes in casting coronal diameter did not demonstrate any significant differences compared to acrylic patterns.3- The mean average of changes in casting post apical diameter compared to acrylic patterns using pure distilled water was significant.Conclusion: Because the least value in dimensional change was seen in 2/1, 3/1 ratio of silica-sol and distilled water, these ratios are recommended in fabrication of casting posts in order to have maximum accuracy and minimum micro leakage while building crowns and bridges.

The main purpose of this study was to video analysis of footballers injuries participated at Asian Cup 2007. Videotapes for thirty-one out of thirty-two matches of this tournament were recorded by using a video and analyzed by one of authors. One hundred twenty five injuries were recorded for the 31 matches of the Asian Cup 2007-an overall injury rate of 109.7 per 1000 match’s hours or four injuries per match. Significant difference (P<0.05) was found between the six 15-minute periods of the game, most injuries occurred in the last 15 minutes of the second half (23.2%). Also most injury occurred in second half (N=68) than first half (N=49) and extra times (N=8). Most injuries significantly (P= 0.001) occurred in the goal area. Also strikers (23.2%) significantly (P<0.05) more injured than other players and most of the injuries resulted from aerial duels (28%), (P= 0.001). The most common site of injuries was the lower leg (20%). This study shows factors such as time elapse of the game, player position and zone of the pitch can be affected player injuries and these factors should be considered by medical staff and coaches for design prophylactics programs.

In order to make a physical fitness profile for senior Iranian free style wrestlers, 73 wrestlers (aged 24.4±2.6 years, body weight 79.9±18.4kg) who were invited to the national training camps over the one year were tested in body composition (3-sites skin fold, LBM, BMI), relative strength (hand grip, bench press, squat, dead lift), muscle endurance (sit-ups, push - ups, pull- ups), VO2 max (Bruce test), speed (36m running), agility (4x 9 m running), flexibility (sit and reach, trunk extension, shoulder flexibility), reaction time (bilateral), alactic anaerobic power (ergo jump 15s, arm Wingate 8s, leg Wingate 8s), lactic anaerobic power (ergo Jump 30s). Major results (mean+SD) areas follows: BF%=11.5±3.5, LMB= 70.4±15.5 kg, BMI = 36.8±6.3 Kg/m2, hand grip=0.92±0.12 WIN, bench press=1.45±0.21 W/kg, squat = 1.83±0.21 W/kg, dead lift = 1.87±0.24 W/kg, sit-ups = 70.9±7.9 n/min, push-ups=35.9±10.9n,VO2 max=50.6±5.7ml.kg-1 .min-I, 36m running = 5.1±0.25 s, 4x9 m running= 8.43±0.38s, sit and reach = 41±4.9 cm, trunk extension= 0.61±0.12 cm/cm, shoulder flexibility = 0.55±0.16 cm/cm, bilateral = 391.7±60.2 ms, ergo jump 15s = 49±6.4W.kg-1, arm Wingate 8s = 375.6±98.9w, leg Wingate 8s = 496.1±101.1w, ergo jump 30s = 43.9±6.7 w. Kg-1. After data gathering, descriptive statistics were used for providing a profile for a above - mentioned tests by SPSS and EXCEL.

Persian Gulf has always been concerned due to its geo-economic and geo-strategic position. Increasing the consumption of world energy simultaneously faced with decreasing of oil reserves in other parts of world let to the importance of Persian Gulf as a major center for world energy demand. Energy has a direct impact on the economic growth, welfare and national security of all countries and the U.S.A. as a big consumer of world energy will be influenced by all changes due to supplying of it. From this point of view, accessing to a safe and continuous energy supply will be vital to the interests of the W.S.A. government.On the other hand, the role of energy is not ignorable in the structure of security of Persian Gulf. Oil plays a major role in the political stability, welfare and finally the maintenance of Persian Gulf countries.While security has a basic and major role for Producers and consumers of energy, especially the U.S. government, the article attempts to analyze the relationship between energy and security in the Persian Gulf region. Its aim is to present a pattern for participated security for benefits of all Persian Gulf countries regarding present facts.

Occupational exposure to heavy metals, organic solvents and silica is associated with a variety of renal manifestations. Improved understanding of occupational renal disease provides insight into environmental renal disease, improving knowledge of disease pathogenesis. Silica (SiO2) is an abundant mineral found in sand, rock, and soil. Workers exposed to silica include sandblasters, miners, quarry workers, masons, ceramic workers and glass manufacturers. Newcases of silicosisper year have been estimated in the USto be 3600-7300. Exposure to silica has been associated with tubulointerstitial disease, immune-mediated multisystem disease, chronic kidney disease and end-stage renal disease. A rare syndrome of painful, nodular skin lesions has been described in dialysis patients with excessive levels of silicon. Balkan endemic nephropathy is postulated to be due to chronic intoxication with drinking water polluted by silicates released during soil erosion. The mechanism of silica nephrotoxicity is thought to be through direct nephrotoxicity, as well as silica-induced autoimmune diseases such as scleroderma and systemic lupus erythematosus. The renal histopathology varies from focal to crescentic and necrotizing glomerulonephritis with aneurysm formation suggestive of polyarteritis nodosa. The treatment for silica nephrotoxicity is non-specific and depends on the mechanism and stage of the disease. It is quite clear that further research is needed, particularly to elucidate the pathogenesis of silica nephropathy. Considering the importance of diagnosing exposure-related renal disease at early stages, it is imperative to obtain a thorough occupational history in all patients with renal disease, with particular emphasis on exposure to silica, heavy metals, and solvents.