The Dalkon Shield was an intrauterine contraceptive device (IUD) that women used in the early 1970s and 1980s. Produced by the A.H. Robins Company in the US, the Dalkon Shield was a contraceptive device placed directly into a woman?s uterus [3] that was supposed to prevent pregnancy [4]. In the 1980s, researchers discovered that the Dalkon Shield caused an array of severe injuries, including pe...

The appearance of the embryonic shield, a slight thickening at the leading edge of the blastoderm during the formation of the germ ring, is one of the first signs of dorsoventral polarity in the zebrafish embryo. It has been proposed that the shield plays a role in fish embryo patterning similar to that attributed to the amphibian dorsal lip. In a recent study, we fate mapped many of the cells ...

A structural and petrological study of the Late Proterozoic rocks in the Wadi Kid area, Sinai, Egypt indicates the presence of an extensional metamorphic core complex in the northern Arabian–Nubian Shield. Gneissic domes throughout the Arabian–Nubian Shield resemble the core complex of the Wadi Kid area and as a result, they are interpreted as extensional metamorphic core complexes. The presenc...

The open-circuit sensitivity of condenser microphones, and in particular Laboratory Standard (LS) and Working Standard (WS) microphones, depend on the mechanical ground-shield configuration of the preamplifier. Therefore, the mechanical ground-shield configurations of preamplifiers for LS and WS microphones are defined in the IEC 61094 standard series. The sensitivity, dynamic range and acousti...

The PULSAR-II pulsed tokamak power plant design utilizes a blanket made of the vanadium alloy, V-5Cr-5Ti, and cooled with liquid lithium. The shield is made of a mixture of the low activation austenitic steel (Tenelon) and vanadium. The blanket is assumed to be replaced every 5.6 full power years (FPY) and the shield is assumed to stay in place for 30 FPY. The activity induced in the blanket at...

Background  It is remain a main concern that pediatric chest radiographies contribute to the significant radiation exposure to the thyroid gland as a more susceptible organ to radiation induced cancer. The aim of this study was to evaluate the entrance surface dose (ESD) of pediatric chest radiography compared to the diagnostic reference levels (DRL) and evaluation the efficacy of the lead (Pb)...

The effect of shield structures for local wirings of analog integrated circuits on crosstalk is determined by electromagnetic simulation. The crosstalk of parallel wirings is reduced to -70 dB by the shield above and between the wirings. The optimal shield structure and terminal-impedance dependence are determined by numerical analysis taking terminal impedance as well as wiring length and widt...

background: breast cancer is the most frequently diagnosed cancer and the leading global cause of cancer death among women worldwide. radiotherapy plays a significant role in treatment of breast cancer and reduces locoregional recurrence and eventually improves survival. the treatment fields applied for breast cancer treatment include: tangential, axillary, supraclavicular and internal mammary ...

Introduction: Venus host two distinctive terrains, one tectonic, the other volcanic. These two terrain types, ribbon tessera terrain and shield terrain are both extensively preserved across the surface of Venus, and they might also show a spatial correlation, which may, in turn reflect a genetic relationship. Geology: Ribbon tessera terrain (rtt) represents the oldest locally exposed unit acros...

Background: Monte Carlo simulations play a vital role in the calculation of the necessary shielding both for neutrons and photons. Advanced and simple shielding materials against neutron and gamma rays were compared by simulation using the MCNB4B Monte Carlo code. The simulations were carried out for the three common neutron sources, namely the 252Cf, the 241Am/Be and the DD neutron generator w...