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 Monte...

During the past 30 years numerous particle accelerators have been developed around the world: the Fermi proton/anti-proton ring in Illinois, the KEK proton synchrotron in Japan, the CERN proton synchrotron in France, and the ISIS pulsed neutron spallation source in Oxford, to name a few. The world’s highest current spallation neutron source is the Los Alamos Neutron Science Center (LANSCE) at L...

Moderation policies of “free speech” and “safe space” have often been equated to lowand highcensorship levels. However, this paper proposes that moderation policies of “safe space” and “free speech” can also be thought of as a design choice that establishes norms of how individuals should treat each other in that discussion space. Analysis of word usage in matched Reddit communities provides ev...

in the present work, we have obtained the equation of state for neutron star matter considering the in uence of the ferromagnetic and antiferromagnetic spin state. we have also investigated the structure of neutron stars. according to our results, the spin asymmetry stiens the equation of state and leads to high mass for the neutron star.

background: in neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials.   objective: the purpose of this study is to evaluate dose distribution in the presence of  10 b ,  157 gd  and  33 s  ne...

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: the aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or pmma), a150 plastic and te- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. materials and methods: thermal neutron fluence, photon dose and epithermal neut...

The current study investigated concurrent and longitudinal mediated and mediated moderation pathways among maltreatment, self-perception (i.e., loneliness and self-esteem), social support, and internalizing and externalizing behavior problems. For both genders, early childhood maltreatment (i.e., ages 0-6) was related directly to internalizing and externalizing behavior problems at age 6, and l...