We investigate the sources of changes in GDP volatility observed from 1966 to 2018. develop a general equilibrium model and calibrate it US data characterize contribution micro level productivity shocks, inter-sectoral linkages households' behavior aggregate volatility. Our results show that sectoral played an important role shaping asymmetries economy had different impact on over time. Moreove...

background: prompt gamma neutron activation analysis (pgnaa) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. also it is a valuable diagnostic tool for total body elemental measurements. 252cf and 241am-be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

Following the victory of the Islamic Revolution of Iran and establishment of new government within the framework of political Islam in the region, in order to continue and reinforce this government model, the Islamic –Iranian Model of Progress was put in the blueprint with regard to the indigenous standards as the most important pre-occupation. After the third decade of the Revolution which has...

Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...

Social scientists are increasingly interested in multilevel hypotheses, data, and statistical models as well as moderation or interactions among predictors. The result is a focus on hypotheses and tests of multilevel moderation within and across levels of analysis. Unfortunately, existing approaches to multilevel moderation have a variety of shortcomings, including conflated effects across leve...

Online communities provide a social sphere for people to share information and knowledge. while information sharing is becoming a ubiquitous online phenomenon, how to ensure information quality or induce quality content remains a challenge because of the anonymity of commentators. this paper introduces moderation into reputation systems. we show that moderation directly affects strategic commen...

Introduction: Environmental and occupational human exposure from neutron source can lead to the serious biologic effects. The aim of this study is to evaluate the cancer incidence risk for various human organs at different neutron dose levels due to exposure from an Americium-241/Beryllium (Am-241/Be), a standard neutron source for calibration purposes. Material and Methods: We measured ambient...

Neutron sources employed in different applications in both medicine and industry. Due to the harmful effects of neutron particles on living organisms, radiation shields have played a vital role in radiation protection against neutrons. In recent decade, numerous investigations conducted on the design and fabrication of nanocomposites as more efficient shielding materials against fast and therma...