background: radon and its daughters are amongst the most important sources of natural exposure in the world. soil is one of the significant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause increased uncertainties in radon measurements. recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of rado...

background: separate radon and thoron measurements in soil are very important in assessment of internal exposure due to inhalation of such radioactive gases. materials and methods: in this study, a low cost, small size, passive diffusion chamber has been developed for simple measurement of radon-222 and radon-220(thoron) gases separately in soil. the diffusion chamber consists of two films and ...

english passive has always been regarded as a challenge by farsi-speaking efl learners. despite the presence of many linguistic and pedagogical approaches in studying and teaching english passive, there still appears to be a pedagogical gap facing farsi-speaking efl learners dealing with this construction. taking up the cognitive-construction grammar perspective, the present article aims to inv...

Objectives: Specific language impaired children, despite being normal in cognitive and neurological characteristics, and also normal levels of hearing, experience multiple problems in syntax comprehension. This study compared the passive comprehension as one of Syntactic Structures in Persian-speaking typically developing children and Specific language impaired children. Methods: 10 children w...

In this study, the effect of molybdate on the electrochemical behavior and semi-conductive properties of duplex stainless steel 2205 passive film at NaCl solutions was investigated. Cyclic potentiodynamic polarization, impedance spectroscopy, mott-schottky plots and scanning electron microscopy (SEM) were used to study the passive behavior. Polarization curves showed that the corrosion current ...

the history of five thousand years of human civilization (with only 292 years with no war) and the experiencesof the past two decades of our country shows that the enemies’ approach is based on strong air attack just inthe first month, and civilians bombarding begins if the spirit of national defense continues after two weeks.so the buildings in the cities are damaged in different ways by the a...

In the last twenty years, application of microreactors in chemical and biochemical industrial processes has increased significantly. The use microreactor systems ensures efficient process intensification due to excellent heat mass transfer within microchannels. Monitoring concentrations microchannels is critical for a better understanding physical occurring micromixers microreactors. Therefore,...

this paper is an attempt to explore the prepositions used to encode the agent in persian passive constructions. according to givón (1983) the main function of the passive constructions is to defocus the agent. as the general trend in persian is to omit this defocused agent, we will stylistically divide the passive constructions into two main sub branches, namely unmarked and marked passives acc...

the harmonic in distribution systems becomes an important problem due to an increase in nonlinear loads. this paper presents a new approach based on a graph algorithm for optimum placement of passive harmonic filters in a multi-bus system, which suffers from harmonic current sources. the objective of this paper is to minimize the network loss, the cost of the filter and the total harmonic disto...