Mathematical Study of Nonlinear Mixed Convection Unsteady Flow in a Parallel Plate Inclined Channel in the Proximity of Time Periodic Boundary Conditions: Flow Reversal

This report is executed to examine the task of assimilating parameters on bipartite convection stream structure in a sloped pipeline while certain plate is disorderly warmed. The dictating motivation and energy identifications are ascertained and consequent expressions for thermal reading, liquid movement, fanning friction and stress flatten are acquired. The purpose of non-linear Boussinesq simulation is to escalate liquid movement, inverse stream generation at the channel plates, stress flatten, and fanning factor. In particular, the liquid motion escalates at the channel left portion and depletes at the channel right portion with the progress of time. A particular case of our development shows an excellent compromise with the previous consequences in the literature.

Auroral streamers: characteristics of associated precipitation,convection and field-aligned currents

During the long-duration steady convection activity on 11 December 1998, the development of a few dozen auroral streamers was monitored by Polar UVI instrument in the dark northern nightside ionosphere. On many occasions the DMSP spacecraft crossed the streamer-conjugate regions over the sunlit southern auroral oval, permitting the investigation of the characteristics of ion and electron precipitation, ionospheric convection and field-aligned currents associated with the streamers. We confirm the conjugacy of streamer-associated precipitation, as well as their association with ionospheric plasma streams having a substantial equatorward convection component. The observations display two basic types of streamer-associated precipitation. In its polewardmost half, the streamer-associated (field-aligned) accelerated electron precipitation coincides with the strong (≥2–7μA/m2) upward field-aligned currents on the westward flank of the convection stream, sometimes accompanied by enhanced proton precipitation in the adjacent region. In the equatorward portion of the streamer, the enhanced precipitation includes both electrons and protons, often without indication of field-aligned acceleration. Most of these characteristics are consistent with the model describing the generation of the streamer by the narrow plasma bubbles (bursty bulk flows) which are contained on dipolarized field lines in the plasma sheet, although the mapping is strongly distorted which makes it difficult to quantitatively interprete the ionospheric image. The convective streams in the ionosphere, when well-resolved, had the maximal convection speeds ∼0.5–1km/s, total field-aligned currents of a few tenths of MA, thicknesses of a few hundreds km and a potential drop of a few kV across the stream. However, this might represent only a small part of the associated flux transport in the equatorial plasma sheet.Key words. Ionosphere (electric fiels and currents). Magnetospheric physics (aurroal phenomena; energetic particles, precipitating)

Variation of Sidestream Gas Formation during the Smoking Cycle

External contour distributions for gas temperatures and for the concentrations of carbon monoxide, carbon dioxide, hydrogen and oxygen are reported at successive times in the smoking cycle. The sidestream gases leave the coal in a vertical column centering at about 3 mm in front of the paper burn line. The levels of oxygen and the carbon oxides outside the coal are not primarily determined by any diffusion gradient originating in the inner coal. Rather, the external levels are determined partly by a convective current set up by the hot coal, and influenced by buoyancy effects. The oxygen in the convection stream forms the oxides of carbon on the hot surface of the coal, and the convected air is transported around the coal in an upwards direction. On the other hand, the hydrogen levels outside the coal result from diffusion from the inner coal, although much of this outward diffusing hydrogen is oxidised to water on the surface of the coal. The visible sidestream smoke column is about 3 mm in diameter and its centre is about 5 mm behind the sidestream gas column, becoming visible when the temperatures in the gas column are below about 150°C. The vapour which eventually condenses to form mainstream and sidestream smoke is released in the general pyrolysis / distillation region of the cigarette, just behind the paper burn line. Some of this vapour diffuses to the outside of the cigarette, through the partially degraded paper, and it condenses to form the sidestream smoke particles once outside the coal.

Total Water Content of Mainstream Smoke and Sidestream Smoke / Über den Wassergehalt von Haupt- und Nebenstromrauch

The present paper gives a balance of total water (comprising moisture content of tobacco as well as water of combustion) in the smoking of a plain cigarette without filter under standard conditions. 62.8 % of the hydrogen originally present in the burnt portion of the cigarette are transformed into water. The sidestream smoke is enriched by the total water to a large extent, i.e., in proportion to the total water of a cigarette, 14.4 mg of water are calculated to be transferred to the mainstream smoke and 344.7 mg to the sidestream smoke and to the ashes. 14.6 % of the said hydrogen are found to be delivered into the condensates of main and sidestream smoke in the form of slightly volatile compounds containing hydrogen. The residual 22.6 % are transferred into the gas-vapour phase in the form of volatile compounds. The interpretation of temperature measurements made along the axis of and in the space above a freely smouldering cigarette (without drawing) as well as the determination of the velocity (33 cm/sec) of the escaping sidestream smoke indicate the presence of a rapid and steep convection stream over the glowing zone. This finding accounts for the large water enrichment of the sidestream smoke and for the fact that water formed by the combustion process does not contribute to the transfer of steam-volatile substances into the sidestream smoke.