background: radon and its daughter product are a major source of natural radiation exposure, the measurement of radon concentration in dwellings is assuming ever increasing importance. it is known from recent surveys in many countries that radon and its progeny contributes significantly to total inhalation dose and is well established that radon when inhaled in large quantity causes lung disord...

background: the natural radionuclides are always present in soil and care needs to be taken to minimize the radiation dose to humans. these radionuclides are mostly gamma ray emitting radionuclides which contribute to the radiation dose in long term behavior of radionuclides in soil. health hazards associated with natural radioactivity are of great concern and it is necessary to assess risk due...

the role of unit hydrograph is very important in prediction of floods in the rivers, design protection and control structures in the catchment area. therefore in the basin without hydrometric stations, by using mathematical and empirical relationship and based on climatic data, the water level in the basin is estimated. two methods of geomorphologic instantaneous unit hydrograph and width funct...

Length frequency data of the longtail tuna, Thunnus tonggol collected from October 2006 to September 2007 were analyzed for evaluation of the stock parameters. T. tonggol is mainly caught by gillnet method. Yearly tuna and tuna-like catches in Iran are of the order of 174,234 mt, close to 46% of which are longtail tuna. The VBG parameters for longtail tuna were: L∞ =133.72cm K=0.35 year−1.The l...

Length frequency data of the longtail tuna, Thunnus tonggol collected from October 2006 to September 2007 were analyzed for evaluation of the stock parameters. T. tonggol is mainly caught by gillnet method. Yearly tuna and tuna-like catches in Iran are of the order of 174,234 mt, close to 46% of which are longtail tuna. The VBG parameters for longtail tuna were: L∞ =133.72cm K=0.35 year−1.The l...