javad sheikh

Guiding the engineering process in systems has created an interdisciplinary approach called system engineering. The concept of guidance in the first step means choosing the best path among the existing paths and then guiding, directing and managing the process in the selected path. In this context, requirements management is one of the first stages of the product development process, which can engineer the requirements with a comprehensive and accurate view and produce a product that meets the needs of users.The purpose of preparing this research, which was carried out in the period of 1402-1401, is to implement all requirements management activities in a marine system. For this purpose, at first, the basic requirements related to this product were extracted from different sources, categorized and then the metadata of the requirements was prepared, and one or more confirmation methods were provided for each of them. Finally, the relationship between the requirements has been determined and after resolving the conflicts between them, the metadata of the requirements has been updated. According to the results of this process, 106 requirements have been identified. These requirements will be considered as the basis for starting the product development and design process.

The quantitative and qualitative management of urban runoff is a very complicated. Regardless of the economic and social impacts, water engineers always need to know how to respond to a citychr('39')s drainage system against different climatic conditions. In this research, the combination of ASSA and GIS models in the returns periods of 2, 5, 10 and 50 years were used to determine the flooding points in the 9th district of Mashhad municipality. First, the watershed boundaries, canals and nodes maps was extracted from the GIS environment. Then the ASSA model was simulated for a One-hour design for a different return period. Then, the outputs of the model were analyzed in the GIS software environment. The results showed that with increasing rainfall return period, 2806 nodes in underground and superficial networks of 114, 178 and 226 nodes were flooded and inundation during the return periods of 2, 5, 50 and 50 years, respectively. Field surveys, existing elevation digital maps of the urban runoff network and simulations have shown that the main cause of inundation is the small size of the cross section of the duct, as well as the low slope in some parts of the network. Adaptation of the results of the simulation of rainfall-induced waterlogging in the study area with what happens every year confirms indicates the correctness of the simulations of the model. Moreover, simulation results of the model also showed that there is a good agreement between the simulated results and the measurement.

Evapotranspiration as an important component of the hydrologic cycle plays a large role in watershed’s water balance study. Accurate estimation of evapotranspiration rate is essential for efficient management of irrigation, determination of plants water demand as well as design of irrigation systems. The aim of the current study is to design and construct a weighing lysimeter to address the need for accurate monitoring of evapotranspiration. The designed lysimeter in this research contains two concentric cylinders. The internal cylinder is the main container of the lysimeter and outer cylinder has the role of protection and isolation of the main container from surrounding soil media. The main container is open-ended from top, but sealed in sidewalls and bottom end, except for orifices at the bottom end to drain the saturation excess water from main container. The main container was made from 3 mm and 6 mm thick steel sheets for sidewall and bottom, respectively. The inner diameter and depth of the main container were 45 cm and 60 cm, respectively. After filling with soil, the containers were loaded on relatively precise and cheap loadcells fixed to a rigid metal framework. An electronic board, which can support four loadcells, was developed for calibration of loadcells and setting up the monitoring and recording the output signals of loadcells as a text file saved on an external memory card. The board can display the instantaneous weight of containers and save them at user defined intervals. The results of performance evaluation indicated that the developed lysimeter can measure and record temporal changes of soil moisture with an acceptable accuracy.

During the history, the notion of property rights has been changed in legal systems, and different perspectives towards it have been emerged that we can classify these perspectives towards property rights into common and new ones. In this paper, these two perspectives have been studied in order to present a clearer conceptualization of property rights and it has been tried to compare and discuss the current perspectives in statute and comparative law, and the strengths and shortcomings of these perspectives were clarified. Finally, based on the analytical discussion, conclusions were made. Also the perspective that seemed to be realistic and had a scientific and logical justification was introduced to the reader and strengthened.