background: in radiation therapy, peripheral dose or the dose outside the radiotherapy field, is important when anatomical structures with very low dose tolerances are involved. one of these critical organs in pelvic irradiation is testis. the amount of radiation delivered to the testes in radiotherapy must be kept as small as possible, consistent with the limit dose of this organ. the threshol...

introduction the use of cut-outs in electron applicators make changes on output, isodose, and percentage depth dose (pdd) curves. these changes and electron beam dose distribution in the form of three-dimensional (3d) can be measured by gel dosimeters. materials and methods dosimetry was performed with and without a square shield (6×6 cm2 field). the energies were 4, 9, and 16 mev and phantom w...

Radiofrequency (RF) shields have been recently developed for the purpose of shielding portions of the patient's body during magnetic resonance imaging (MRI) examinations. We present an experimental evaluation of a commercially available RF shield in the MRI environment. All tests were performed on 1.5 T and 3.0 T clinical MRI scanners. The tests were repeated with and without the RF shield pres...

Crosstalk in VLSI interconnects is a major constrain in DSM and UDSM technology. Among various strategies followed for its minimization, shield insertion between Aggressor and Victim is one of the prominent options. This paper analyzes the extent of crosstalk in inductively coupled interconnects and minimizes the same through distributed shield insertion. Comparison is drawn between signal volt...

Introduction My previous note focused on pin 1 problems as an open door for RF into audio equipment. But RF can also enter equipment on the signal conductor(s) if the equipment fails to block it with an effective low pass filter. RF is induced on a shielded balanced pair by at least three mechanisms: • Imbalance in the magnetic coupling between the shield and the two signal conductors (Shield-c...

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...

exposure buildup factors have been calculated by monte carlo method for point isotropic gamma ray sources, penetrating a two-layer spherical shield of water surrounded by lead, and the effect of bremsstrahlung radiation on buildup factors has, in particular, been investigated, the results of which are in good agreement with previous works. the buildup factors were then calculated for various co...

Metallic eye shields have been widely used for near-eye treatments to protect critical regions, but have never been incorporated into treatment plans because of the unwanted appearance of the metal artifacts on CT images. The purpose of this work was to test the use of an acrylic dummy eye shield as a substitute for a metallic eye shield during CT scans. An acrylic dummy shield of the same size...

Electromagnetic shield made up of single conductor layer of chosen thickness and conducting material can be designed to achieve required shielding performance . This single conductor layer electromagnetic shield would be bulky and occupy more volume when the size of the electronic circuit is shrinking with the advent of microelectronic technologies. In order to optimize the thickness of the ele...

Four 12-rung linear birdcage-type coils were built to experimentally examine the effects of the end-ring/shield configuration on radiofrequency magnetic field (B(1)) homogeneity and SNR at 125 MHz. The coil configurations include (a) a cylindrical shield (conventional), (b) a shield with annular extensions to closely shield the end-rings (surrounding shield), (c) a shield with annular extension...