Stellar Populations of Lyman Break Galaxies at z approx. to 1-3 in the HST/WFC3 Early Release Science Observations

We analyze the spectral energy distributions (SEDs) of Lyman break galaxies . (LBGs) at z approx = 1-3 selected using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) UVIS channel filters. These HST /WFC3 obse,rvations cover about 50 arcmin2 in the GOODS-South field as a part of the WFC3 Early Release Science program. These LBGs at z approx = 1-3 are selected using dropout selection criteria similar to high redshift LBGs. The deep multi-band photometry in this field is used to identify best-fit SED models, from which we infer the following results: (1) the photometric redshift estimate of these dropout selected LBGs is accurate to within few percent; (2) the UV spectral slope f3 is redder than at high redshift (z > 3), where LBGs are less dusty; (3) on average, LBGs at .z approx = 1-3 are massive, dustier and more highly star-forming, compared to LBGs at higher redshifts with similar luminosities, though their median values are similar within 1a uncertainties. This could imply that identical dropout selection technique, at all. redshifts, find physically similar galaxies; and (4) the stellar masses of these LBGs are directly proportional to their UV luminosities with a logarithmic slope of approx 0.46, and star-formation rates are proportional to their stellar masses with a logarithmic slope of approx 0.90. These relations hold true - within luminosities probed in this study - for LBGs from z approx = 1.5 to 5. The star-forming galaxies selected using other color-based techniques show similar correlations at z approx = 2, but to avoid any selection biases, and for direct comparison with LBGs at z > 3, a true Lyman break selection at z approx = 2 is essential. The future HST UV surveys,. both wider and deeper, covering a large luminosity range are important to better understand LBG properties, and their evolution

THE USE OF TUBULAR BELT CONVEYORS FOR THE INDUSTRIAL WASTE OF ENTERPRISES

Urgency of the problem. There is a critical situation in the segment of mining hoists. A traditional cable car skip hoist has almost exhausted its possibilities. The increasing depth of deposits and the productivity growth of development machines and clearing combines stipulate bigger capacities, sizes and speed of skips. This increases the power and weight of lifting machines, the number and diameter of cables, the height of the copra, and the diameter of the shaft are increased too. The search for alternative methods of mine lifting, which have a higher specific productivity is being carried out. It leads to a clear conclusion about the prospects of the transition from rope pneumatic lifting units to the skip ones. Purpose of the work: to ensure the stability of the vessel movement in the mine skip pneuvmo elevating equipment. Research methodology: to reduce the non-return energy losses on the rise of the skip’s own weight, a closed pneumatic system is organized: the outlet section of the descent pipeline is connected with the inlet window of the blower. The blower receives the flow pressure, which is determined by the weight of the empty skip, with the result that the energy consumption of the lift depends only on the weight of the mineral. The optimal operation of the closed system is possible only at a certain value of the pipeline diameter. Results. The design and operation principle of the proposed air-lifting installation are described, the method of calculating the diameter of the pipelines for the implementation of air exchange between the descents and lifting pipelines is given. Conclusion. The article substantiates the new design of the skip pneumatic lifting installation, which has a higher performance and energy efficiency. This is achieved by means of reducing the aerodynamic drag of the track and eliminating the irrevocable energy costs for the rise of its own mass of the skip. According to the method proposed, the stability of the vessel in the descent pipeline of the pneumatic lifting installation is calculated