Autecological studies which is concerned with the study of relationship between species with surrounding environment provide basic information for the management of rangeland ecosystems. The autecological study Capparis spinosa L. was carried out in Sistan region.After determining habitat of this species, edaphic and climatic features relevant habitat, plant root systems, procedures phenology, seed weight and number of buds on each base were determined. The results showed that these spccies have been in sites such as discrete Eastern and had been Western parts of the region. Soil habitat of this species sandy loam texture and sandy clay loam, pH 8 to 6.8, and soil salinity, 3.1 to 7.58 dS. The average plant canopy covered 9 to 5.17 percent in the respective habitat. These racing roots up to two meters deep were observed. Phenological stages of the study species showed that the growth of then started and early in flowering march pully plants June was observed. The seeds in the beginning and middle of the June and also middle of August were observed August. The number of buds on each base were 30 and the weight of thousand seeds was 4-2 gram. Due to high resistance against these adverse natural conditions such as extreme heat zone, low humidity and sand storms, can be used in revived and reformed program in Sistan plain pastures.

Coexisting with humans since olden times, pigeons played a notable role in most human societies. Thus, one can examine their status and function as a social component. The current article looks at pigeons from a social perspective and scrutinizes literary texts (stories, literary pieces in prose, poets’ writings) and religious and historical ones to study their roles, functions, and uses in human communities. To this end, the study initially investigated pigeons’ images in the Koran and religious texts. The study found that pigeons enjoyed reverence and sanctity in such a way that religious rules were established for their slaughtering and hunting. Also, scrutinizing literary and historical texts indicated that pigeons were one of the common pastimes in past eras and pigeon flying was a popular hobby among ordinary folks and even kings. Contrary to the common belief that falcons were the favorite birds of kings, pigeons, according to this study, had special importance for kings. Furthermore, based on this research findings, Iranians held pigeons sacred. They also used them for entertainment and medical and agricultural purposes. Finally, pigeons’ sociability explains their strong presence among humans.

Go-karts are popular sport mini-car in western countries, and there are gaining prominence in developing countries such as Nigeria. Its performance is determined by the chassis design and the braking system is its lifeline. Because of the lack of a suspension system and differentials, a good chassis must be able to bend and twist. This Go-kart is powered by a Yamaha Vino Automatic Petrol 2-stroke Engine that generates approximately 4. 1kw of power at 9018rpm. It boasts slick tyres for increased grip and a hydraulic disc brake for smooth and effective braking in both wet and dry conditions. The focus of this paper is on the braking system and material characterization of its structural members Simulation static study with Autodesk Inventor yielded the following results: Mass Density 281. 550 lbmass/ft3 Yield Strength 40. 000 ksi Ultimate Tensile Strength 50. 000ksi. Design calculations were performed, and the best possible result was obtained. Ergonomics, safety, cost of manufacturing, and reliability are all considered.

The human-pigeon relationship that has met human's different demands has a very long history. But nowadays pigeons are considered as an entertainment. This paper examines a group of pigeon fanciers who breed and fly pigeons from their rooftops in Tehran. This research, by focusing on a specific group of pigeon flyers of Tehran and their annual ceremonies and competitions known as "GERO", tries to document and analyze changes of fanciers' social life and jargons along with an ethnographic documentation of the event and its relations. During these changes, the number of pigeons and costs of breeding impact on their social status and relationships. As the costs have been increasing during recent years, the social status has been under the shadow of the number of pigeons he keeps and the expenses he spends for breeding and feeding them. Consequently the symbolic capital among their society is replaced with economic capital and therefore, this new capital has become a determinant of the position of the men in their social relations.

Motorcycles under heavy braking conditions can experience a self-excited oscillation known as ‘chatter’. A simplified three degrees of freedom model of the rear of a motorcycle is developed to study the stability of this mode with the inclusion of lateral dynamics introduced by roll angle. Since motorcycles achieve high roll angles during operation, the study of chatter during these manoeuvres is a topic of interest. The equations of motion are linearised about a quasistatic equilibrium and simplified to accommodate symbolic inspection. Power analysis, eigensystem analysis, eigenvalue sensitivity and Routh-Hurwitz stability criterion are used to study the stability of the system in the braking region. It was found that a driveline mode can become unstable at about 19 Hz, and that its tendency towards instability is increased with added roll angle. This mode is sensitive to model parameters affecting the system inertia and stiffness, as well as the chain geometry. Finally, it is found that the lateral dynamics and roll angle play no direct role in chatter but have a significant indirect effect on it through the working point of the force characteristic function of the tyre.