results significantly high levels of radon gas were found mostly in water and residential buildings. conclusions it conclusion with regard to the study of building materials, granite stone and adobe coverings cannot be recommended for construction purposes. materials and methods the most important route of exposure to such radiation is indoor places. in this investigation measurement of radon i...

ABSTRACT: In this paper, the thermal characteristics of single and double flow plane solar heaters with radiating working gas were analyzed and compared by numerical analysis for the first time. The laminar mixed convection gas flow in the heaters was numerically simulated by the CFD method using the finite volume technique. The set of governing equations included the conservation of mass, mome...

The NDIR gas detection method is based on the absorption of infrared radiation, which is shown by many polyatomic or heterodimer diatomic gases. For example CO2 gas absorbs IR radiation at 4.26μm wavelength. The detected radiation intensity at this wavelength decreases if the concentration of CO2 increases between source and detector. The extent of absorption mainly depends on the absolute numb...

From the point of view of radiation safety, interstellar space is not empty. Neutral and ionized interstellar gas and cosmic rays consisting of H and He-nucleons constitute radiation hazard aboard relativistic interstellar ships. Relativistic aberration of cosmic rays is evaluated and radiation doses from oncoming relativistic flow of interstellar gas and cosmic rays are estimated. Necessary sh...

this work presents the heat transfer characteristics of a new type of porous radiant air heater that operates on the basis of effective energy conversion method between flowing gas enthalpy and thermal radiation. at each layer, the gas and solid phases are considered in non-local thermal equilibrium, and combustion in the porous radiant burner is modeled by considering a non-uniform heat genera...

We present infrared and millimeter observations of molecular gas, dust and ionized gas towards a sample of clouds distributed along the 500 central pc of the Galaxy. The clouds were selected to investigate the physical state, in particular the high gas temperatures, of the Galactic center region (GCr) clouds located far from far-infrared of thermal radio continuum sources. We have found that th...

The Advanced Photon Source (APS) currently under construction at Argonne National Laboratory will be one of the world’s brightest synchrotron radiation facilities. The storage ring, capable of storing currents up to 300 mA at 7.0 GeV and 200 mA at 7.5 GeV, will produce very intense and energetic synchrotron radiation (Ec = 24 keV for bending magnets and Ec = 37.4 keV for wigglers, where Ec is t...

We report the development and characterization of high quality polyaniline-silicon heterojunction diodes appropriated for use as gas and/or ionizing radiation sensors. Polyaniline thin lms 40 nm thick are an active part of the junction structure, that presents excellent electrical characteristics, with rectifying ratio of 50,000 at 1.0 Volt bias. The devices are very sensitive to -radiation up ...

We examine the small-scale dynamics of black hole accretion disks in which radiation pressure exceeds gas pressure. Local patches of disk are modeled by numerically integrating the equations of radiation MHD in the flux-limited diffusion approximation. The shearing-box approximation is used, and the vertical component of gravity is neglected. Magneto-rotational instability (MRI) leads to turbul...