Dusty tori around active galactic nuclei (AGNs) play an important role in the classification of Seyfert galaxies. (Antonucci & Miller 1985; see also Antonucci 1993 for a review). Seyfert galaxies observed from a face-on view of the torus are recognized as type 1 Seyferts (S1s) while those observed from an edge-on view are recognized as type 2 Seyferts (S2s). Therefore, physical properties of du...

the flame propagation through a coal dust-air mixture in a spherical vessel was studied by means of a one-dimensional, arrhenius-type kinetics and quasi-steady model. the model includes the evaporation of the volatile matter of dust particles into a known gaseous fuel (methane) and the single-stage reaction of the gas-phase combustion. effect of venting devices as safety idea and the radiation ...

premixed combustion is widely used for reducing pollutant emission from combustion chambers. however, these systems may be sensitive to complex phenomena such as flashback. in the present study flame, flashback and structure of premixed laminar flames are investigated theoretically. the mathematical model includes the axi-symmetric continuity, navier stocks, energy, and species equations. combu...

Dusty gas flow through isotropic porous media is considered. The equations governing dusty gas flow through free space are intrinsically averaged in order to derive a comprehensive model that describes flow of a dusty gas through porous media. The developed model is capable of describing flow of mixtures with non-uniform number density through variable porosity media, while taking into account ...

We describe a rotating-drum dust-dispersal device, which we have used, in conjunction with an existing Q machine, to produce extended, steady state, magnetized plasma columns. The dusty plasma device (DPD) is to be used for the investigation of waves in dusty plasmas and of other plasma/dust aspects. The device is capable of generating dusty plasmas in which as much as -90% of the negative char...

the moisture flux convergence (mfc) and relative humidity in dusty days at different times and levels over the alvand mountain was investigated. the required basic data for the years 2009-2012, including relative humidity, visibility and synoptic codes, were gathered from hamadan synoptic station, while sea level pressure, uwind, vwind and specific humidity data were gathered from ncer/ncar sit...

Dusty plasma is a multi-particle system of dust particles suspended in plasma, which generally composed free electrons, ions, and particles. It widely found natural space aerospace equipment, such as the Earth’s ionosphere, rocket tail flame, sheath hypersonic vehicle. The will interact with electrons ions so that are charged. They also significantly change characteristics dusty showing some ph...

The flame stability limit, which was involving the critical flow condition, lift off and blow out, could be affected by the burner geometry in the combustion system installation. Consequently a flame holder should be put in, to hold the flame as big as possible on a stable condition. The flame holder itself, is a device to hold the flame, whereas the flame holder could disturb the air and fuel ...

The four processes involved in the flammability of materials are described and related to the various flame retardance mechanisms that may operate. Following this the four practical approaches used in improving flame retardance of materials are described. Each approach is illustrated with a number of typical examples of flame retardants or synthetic procedures used. This overview of flammabilit...