Global climate change and its effect on water resources have further reduced the amount of water available for agriculture. Under this circumstance, the use of pressurized irrigation systems can be an option of enhancing the efficiency of water consumption. The mobile rain gun is very useful equipment which can be used for irrigating large areas and it works at a minimum pressure of 2kg/cm² . The mobility of the equipment is possible at minimum pressure of 6kg/cm² pressure. For the calculation of uniformity in irrigation catch can test were conducted at various pressure by using various nozzle. The Christiansen’ s equation for uniformity was used for calculation purpose. The grid is plotted for the spacing 3x3 meters and it covers an area of about 360m² . The maximum uniformity was noted in the 12mm nozzle at 2kg/cm² pressure. The uniformity is much reduced for the high pressure due to wind drift and pressure fluctuations. The contour graphs were also used to find out the area of highly uniform distribution. The tape was used for measuring the throw range of rain gun during operation. The throw range varies from 8 to 30m for 10mm at 2kg/cm² and 14mm at 6kg/cm² respectively. The distribution graph was drawn to find out the change in distribution of water along with the change in distance from the rain gun. The rain gun is designed to irrigate large area by using a single unit so the distribution is more for large ranges compared to the places which are nearer to the implement. One of the major problem occur during the sprinkler irrigation is evaporation loss of spraying water. The distribution of water depended upon the things like pressure, climatic condition, wind speed, wind direction and the temperature.

Runoff and soil erosion from agricultural farms is one of the important phenomena because of its impacts on farm fertility. In this regards, type of the irrigation system has the great effect on runoff and soil erosion. Sprinkler irrigation with traveling rain-gun may causes runoff and erosion on field. One of the essential measures for controling and reducing of runoff and soil erosion under gun sprinkler irrigation is simulation of this phenomenon. In this regard EUROSEM model is one of the computer models. However applicability of the model should be assessed. In this research efficiency of the EUROSEM model for estimating runoff and soil erosion has been evaluated by using field investigation in a research farm with two slope land of 1 and 3 percent located in shahrekord University. Experiments were conducted under rain intensity of 38 mm/hr averagely with coefficient of uniformity of 89.5 percent.Results show that runoff and soil erosion can be successfully modeled by EUROSEM model; but the model to estimate time of starting hydrograph and time of peak flow has more errors. The results show that accuracy of the model to estimate runoff and sediment production is parallel and it was not shown significant difference between estimating of the parameters. In addition, verification procedure of the model shows that if the model to be calibrated for a certain event; one can simulate other events successfully by using the calibrated model. This means that the number of filed measurements can be reduced via application of the model.

The gun barrel erosion is a complex physical process which is defined as the progressive damage of the bore surface. occurrence of this phenomenon of firing due to the enlargement of bore diameter results in reducing of the muzzel velocity, range and accuracy. Generally, gun barrel erosion occurs by chemical , mechanical and thermal mechanisms. Understanding of these mechanisms is useful to find methods of controling this phenomenon. So far, different methods such as steel reinforcement, applying of coatings, and liners on the bore surface, or introducting additives in the gun propellant formulation for control barrel gun have be suggested. Nevertheless, gun barrel erosion still is the most important concerns of scientists. This article discussed about theories and mechanism of gun barrel erosion and methods for controlling this destructive phenomenon.

Background-Ocular injuries caused by BB guns (civil air-powered guns) are serious and may result in total loss of vision. These injuries occur more frequently in children and young adults. Methods-A total of 16 patients with BB gun injuries were seen between September 1996 and September 1999 in Farabi hospital, Tehran University of Medical Sciences and a private eye clinic. Six patients had non-perforating eye injuries. Among 10 cases of perforating eye injuries, 2 had single and 8 had double perforations. All of perforated eyes underwent scleral buckling, lensectomy, vitrectomy and silicon injection, after a period of one to two weeks of observation or until a retinal detachment, retinal traction or posterior vitreous detachment was noted on ultrasonography. Results-Of the 16 patients with BB gun injuries, 15 (93.7%) were males and 1 (6.3%) was female with a variation of age ranging from 3 to 50 years (mean=20.6); 9 (56.2%) of them were 18 years of age or younger. All patients had a preoperative visual acuity of at least light perception. They all had a final visual acuity of hand motion or better. Ten patients achieved a score of 1/10 or better and 5 patients had scored 3/10 or above. Conclusion-This study shows that various vitreo-retinal surgical procedures can help retain vision in some cases of ocular injuries caused by BB gun pellets.

Plasticizers are the most important ingredient of gun propellant. They have essential role in control of ballistic and mechanical properties of gun propellants. Development of new gun propellants requires study of energetic plasticizers effect. There are lots of researches around the synthesize and application of energetic plasticizers resulting to the production of nitro, nitrato, fluoro nitro, fluoro amino and azido based energetic plasticizers. Using these plasticizers in propellants causes the modification of energy and mechanical strength. In this article, some fundamentals properties of plasticizer, such as glass transition temperature and migration of plasticizers, are explained and then some of the novel plasticizers for gun propellants such as Bu-NENA, DANPE, NF, BDNPA/F, DNDA57 are introduces and their effects on ballistic and other properties of gun propellants are considered.