1,486 research outputs found
Assessment of environmental and economic efficiency of iron ore breaking technology using emulsion explosives
Methodology for calculating parameters of drilling and blasting operations for stoping works in mines of Kryvorozhskiy basin and PJSC «Zaporizhskiy iron-ore plant» has been improved with the help of established coefficient of relative capacity for the Ukrainit-PM-2B explosive. A new technology of stoping operations for ore breaking by square-chamber methods at deposit thickness more than 5 m is proposed which assumes usage of emulsion explosives and downward drilling of production hole rings in the direction of underlying drilling horizons. Ecological and economical effectiveness of the proposed ore breaking technology implemented in the extraction chambers was estimated. Regularities of harmful substances hazard index changing were established depending on distance to the emission point when trotyl-contained and emulsion explosives are used. Implementation of the proposed technology allows decreasing prime-cost of 1 ton of ore by 15 % per one extraction unit
Possible effect of extreme solar energetic particle event of 20 January 2005 on polar stratospheric aerosols: direct observational evidence
Energetic cosmic rays are the main source of ionization of the low-middle atmosphere, leading to associated changes in atmospheric properties. Via the hypothetical influence of ionization on aerosol growth and facilitated formation of clouds, this may be an important indirect link relating solar variability to climate. This effect is highly debated, however, since the proposed theoretical mechanisms still remain illusive and qualitative, and observational evidence is inconclusive and controversial. Therefore, important questions regarding the existence and magnitude of the effect, and particularly the fraction of aerosol particles that can form and grow, are still open. Here we present empirical evidence of the possible effect caused by cosmic rays upon polar stratospheric aerosols, based on a case study of an extreme solar energetic particle (SEP) event of 20 January 2005. Using aerosol data obtained over polar regions from different satellites with optical instruments that were operating during January 2005, such as the Stratospheric Aerosol and Gas Experiment III (SAGE III), and Optical Spectrograph and Infrared Imaging System (OSIRIS), we found a significant simultaneous change in aerosol properties in both the Southern and Northern Polar regions in temporal association with the SEP event. We speculate that ionization of the atmosphere, which was abnormally high in the lower stratosphere during the extreme SEP event, might have led to formation of new particles and/or growth of preexisting ultrafine particles in the polar stratospheric region. However, a detailed interpretation of the effect is left for subsequent studies. This is the first time high vertical resolution measurements have been used to discuss possible production of stratospheric aerosols under the influence of cosmic ray induced ionization. The observed effect is marginally detectable for the analyzed severe SEP event and can be undetectable for the majority of weak-moderate events. The present interpretation serves as a conservative upper limit of solar energetic particle effect upon polar stratospheric aerosols
Motif models proposing independent and interdependent impacts of nucleotides are related to high and low affinity transcription factor binding sites in Arabidopsis
Position weight matrix (PWM) is the traditional motif model representing the transcription factor (TF) binding sites. It proposes that the positions contribute independently to TFs binding affinity, although this hypothesis does not fit the data perfectly. This explains why PWM hits are missing in a substantial fraction of ChIP-seq peaks. To study various modes of the direct binding of plant TFs, we compiled the benchmark collection of 111 ChIP-seq datasets for Arabidopsis thaliana, and applied the traditional PWM, and two alternative motif models BaMM and SiteGA, proposing the dependencies of the positions. The variation in the stringency of the recognition thresholds for the models proposed that the hits of PWM, BaMM, and SiteGA models are associated with the sites of high/medium, any, and low affinity, respectively. At the medium recognition threshold, about 60% of ChIP-seq peaks contain PWM hits consisting of conserved core consensuses, while BaMM and SiteGA provide hits for an additional 15% of peaks in which a weaker core consensus is compensated through intra-motif dependencies. The presence/absence of these dependencies in the motifs of alternative/traditional models was confirmed by the dependency logo DepLogo visualizing the position-wise partitioning of the alignments of predicted sites. We exemplify the detailed analysis of ChIP-seq profiles for plant TFs CCA1, MYC2, and SEP3. Gene ontology (GO) enrichment analysis revealed that among the three motif models, the SiteGA had the highest portions of genes with the significantly enriched GO terms among all predicted genes. We showed that both alternative motif models provide for traditional PWM greater extensions in predicted sites for TFs MYC2/SEP3 with condition/tissue specific functions, compared to those for TF CCA1 with housekeeping functions. Overall, the combined application of standard and alternative motif models is beneficial to detect various modes of the direct TF-DNA interactions in the maximal portion of ChIP-seq loci
The minimal compound-complex sentence hierarchy
This article deals with the problem of the study of the subsystem of such type of the Multiple Compound-Complex Sentence as a minimal compound-complex sentence. The authors analyze the formal structure of the multiple compoundcomplex sentences and try to build up the structural models hierarchy of Minimal Compound-Complex SentenceyesBelgorod State Universit
Allelic polymorphism of atoxigenic Vibrio Cholerae strains of housekeeping genes isolated in Siberia and Far East
There were atoxigenic Vibrio cholerae strains housekeeping genes analyzed. There were studied 20 isolates, in which nine sequence types have determined and five of which have described as unique. There were clustersformed as belonging to serogroup: first cluster includes RO-variantstrains and one O139 serogroup strain of V. cholerae, second - all O1 serogroup V. cholerae strains. There are sequence types associated with place and time isolation strains in some cases, although differentiation of the strains, which are formed the dominant sequence type strains group have no spatial and temporal characteristics associated
Features of Reaction of 2-(5-Methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl)-4H-benzo[e]-1,3,2-dioxaphosphorin-4-one with 1,2-Dicarbonyl Compounds
© 2018, Pleiades Publishing, Ltd. 2-(5-Methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl)-4H-benzo[e]-1,3,2-dioxaphosphorin-4-one reacts with perfluorodiacetyl, 3,6-di(tert-butyl)-1,2-benzoquinone and phenanthrenequinone only with the participation of a three-coordinated phosphorus atom to form spirophosphoranes containing acyclic 5-methyl-2- phenyl-2H-1,2,3-diazaphosphol-4-yl substituent, whereas the interaction with tetrachloro-1,2-benzoquinone proceeds via expanding the six-membered heterocycle to the nine-membered one to form 2-(2-phenyl-2H-1,2,3-diazaphosphol-4-yl)-2,9-dioxo-4,5,6,7-tetrachlorodibenzo[d,h]-1,3,8-trioxaphosphonine
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