We have investigated molecular distributions in protoplanetary disks, adopting a disk model with a temperature gradient in the vertical direction. The model produces sufficiently high abundances of gaseous CO and HCO to account for line observations of T Tauri stars using a sticking probability of unity and without assuming any non-thermal desorption. In regions of radius R ∼> 10 AU, with which...

We present a universal framework for tamper and leakage resilient computation on a von Neumann Random Access Architecture (RAM in short). The RAM has one CPU that accesses a storage, which we call the disk. The disk is subject to leakage and tampering. So is the bus connecting the CPU to the disk. We assume that the CPU is leakage and tamper-free. For a fixed value of the security parameter, th...

background and importance: disk sequestration can be defined as a herniated disk with perforation of the fibrous ring (or outermost annulus fibrosus) and posterior longitudinal ligament with migration of the disk fragment to the epidural space. even after the introduction of high-resolution magnetic resonance imaging (mri), it is still frequently misinterpreted as neoplastic masses. unfortunate...

We present NuSTAR hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray wea...

The response of collisionless plasmas to an applied potential can differ from classic Debye shielding, and when the potential is rapidly applied ~‘‘instantaneous shielding’’!, the shielding can differ from when it is slowly applied ~‘‘adiabatic shielding’’!. Experiments demonstrate that when a test potential well is applied to a one-dimensional pure-electron plasma, instantaneous and adiabatic ...

................................................................................................................................... iv 1.0 Introduction ...................................................................................................................... 1 2.0 Basic Concepts in Radiation Protection and Shielding .................................................... 1 2.1 Shieldin...

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...

Uncontrolled exposure to X-band frequency leads to health damage. One of the principles of radiation protection is shielding. But, conventional shielding materials have disadvantages. Therefore, studies of novel materials, as an alternative to conventional shielding materials, are required to obtain new electromagnetic shielding material. Therefore, this study investigated the electromagnetic s...

The electromagnetic interaction between a circular disk with finite conductivity and thickness coaxial loop of constant current is addressed here. the material lead to adoption suitable generalized boundary conditions, problem thereby reduced solution two sets dual integral equations in Hankel transform domain. Such are then solved by expanding spectral unknowns Neumann series Bessel functions....

Introduction: Unwanted exposure of ionizing radiation may result in carcinogenesis, cell mutations, and organ failure. High-atomic number elements such as lead, tungsten, bismuth have been traditionally used for radiation protection. Theoretical and practical studies have shown that a variety of shielding materials e.g. polymer composites (PCs) can be used for attenuation of th...