With the purpose of reducing stray radiation dose (SRD) in out-of-field region (OFR) during radiotherapy with 6 MV intensity-modulated radiation therapy (IMRT), a body-shielding device (BSD) was prepared according to the measurements obtained in experimental testing. In experimental testing, optimal shielding conditions, such as 1 mm lead, 2 mm lead, and 1 mm lead plus 10 mm bolus, were investi...

When considering the space limit of high energy LINAC facility in a hospital, the design of shielding wall is strongly required to optimize the wall thickness. Shielding wall usually consists of concrete, and iron plate is sometimes added in concrete to decrease the wall thickness. We investigated the optimum design of the shielding wall in medical LINAC facility by simulation. The calculations...

Katsumi Ohata* Junichi Sato* ABSTRACT: Magnetic shielding for strong magnets using a high-temperature superconductor that can be operated at liquid nitrogen temperature has been studied. Long and large-cross-section (9 mm wide and 0.5 mm thick) 54-filament Bi-2223/Ag tape was developed. Double pancake coils were wound using the tapes having sufficient bending strain tolerance for the react-and-...

In 1992, E.E.Podkletnov and R.Nieminen find that, under certain conditions, ceramic superconductor with composite structure has revealed weak shielding properties against gravitational force. In classical Newton’s theory of gravity and even in Einstein’s general theory of gravity, there are no grounds of gravitational shielding effects. But in quantum gauge theory of gravity, the gravitational ...

Parameter shielding refers to the situation that one test parameter disables others in test execution. The quality of test case generation techniques is limited by the wide existence of parameter shielding. It is challenging to automatically find out conditions that cause the parameter shielding. This paper presents a novel approach for exploring the shielding conditions of test parameters. Our...

The non-abelian tensor product of groups which has its origins in algebraic K-theory as well as inhomotopy theory, was introduced by Brown and Loday in 1987. Group theoretical aspects of non-abelian tensor products have been studied extensively. In particular, some studies focused on the relationship between the exponent of a group and exponent of its tensor square. On the other hand, com...

Exposure to ionizing radiation in the space environment is one of the hazards faced by crews in space missions. As space radiations traverse spacecraft, habitat shielding, or tissues, their energies and compositions are altered by interactions with the shielding. Modifications to the radiation fields arise from atomic interactions of charged particles with orbital electrons and nuclear interact...

Structural and magnetic properties of purine and pyrimidine nucleotides (CMP, UMP, dTMP, AMP, GMP, IMP) were studied at different levels of ab initio molecular orbital theory. These calculations were performed at the hartree-fock level and density functional B3LYP methods. Geometries were fully optimized by following Cs symmetry restrictions. The standard 6-31G** basis set which includes polari...

In this article, the notions of non-abelian tensor and exterior products of two normal crossed submodules of a given crossed module of groups are introduced and some of their basic properties are established. In particular, we investigate some common properties between normal crossed modules and their tensor products, and present some bounds on the nilpotency class and solvability length of the...