290 research outputs found

    Options for processing of aspen wood to carbon materials

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    Thermochemical processing of aspen wood to produce carbon materials is of interest considering that it allows increasing the cost of its products several times and enhancing the sustainability of forest complex enterprises.Currently, the enterprises are confined to the manufacture of charcoal, although it is possible to produce other carbon materials, such as charcoal briquettes, activated carbon and oxidized coal.While processing aspen wood, it is feasible to arrange manufacturing charcoal briquettes. Increased mechanical strength and high bulk density of briquettes raises the range of economically viable transportation of manufactured products, i.e. logistics is being improved.To obtain stable quality activated carbon from aspen coal, water vapor activation is the least environmentally hazardous. For such activation implementation, we recommend using a rotary kiln equipped with a Z-shaped insert. For reasons of environmental safety, the oxidation of activated carbon is preferably carried out using hot, humid air. In this case, unlike liquid-phase oxidation, no wastewater is formed. © 2019 IOP Publishing Ltd. All rights reserved

    Genomic architecture of parallel ecological divergence : beyond a single environmental contrast

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    The study of parallel ecological divergence provides important clues to the operation of natural selection. Parallel divergence often occurs in heterogeneous environments with different kinds of environmental gradients in different locations, but the genomic basis underlying this process is unknown. We investigated the genomics of rapid parallel adaptation in the marine snail Littorina saxatilis in response to two independent environmental axes (crab-predation versus wave-action and low-shore versus high-shore). Using pooled whole-genome resequencing, we show that sharing of genomic regions of high differentiation between environments is generally low but increases at smaller spatial scales. We identify different shared genomic regions of divergence for each environmental axis and show that most of these regions overlap with candidate chromosomal inversions. Several inversion regions are divergent and polymorphic across many localities. We argue that chromosomal inversions could store shared variation that fuels rapid parallel adaptation to heterogeneous environments, possibly as balanced polymorphism shared by adaptive gene flow

    USE OF ROSUVASTATIN AS A GEROPROTECTOR IN PEOPLE ENGAGED IN NATURAL GAS PRODUCING

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    Background. Prolong contact with manufacturing factors of gas producing, in particular hydrogen sulfide, results in dysfunction of various organs and systems, including immune system, which is involved in regulation of the aging process activity. Absence of effective geropreventive means creates the need for pathogenetic way for aging process deceleration. Aim. To study the geroprotective properties of rosuvastatin in respect of people engaged in the gas producing. Material and Methods. The male workers (n=100) of the company “Gazprom dobycha Astrakhan” were examined. Evaluation of biological age by the method of Chebotarev D.F ., determination of p53 protein and interleukin-8, 10, 18 concentrations by solid phase enzyme immunoassay were performed before treatment start and after 18 months of rosuvastatin taking. Results. Rosuvastatin therapy in dose of 5 mg/day resulted in the reduction in atherogenic lipids, pro-inflammatory cytokine - interleukin-8 and marker of apoptosis - protein p53 as well as aging rate slowdown. Conclusion. Pathogenic method of geroprevention with rosuvastatin 5 mg/day was proposed for people engaged in gas producing

    Multiple chromosomal rearrangements in a hybrid zone between Littorina saxatilis ecotypes

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    Both classical and recent studies suggest that chromosomal inversion polymorphisms are important in adaptation and speciation. However, biases in discovery and reporting of inversions make it difficult to assess their prevalence and biological importance. Here, we use an approach based on linkage disequilibrium among markers genotyped for samples collected across a transect between contrasting habitats to detect chromosomal rearrangements de novo. We report 17 polymorphic rearrangements in a single locality for the coastal marine snail, Littorina saxatilis. Patterns of diversity in the field and of recombination in controlled crosses provide strong evidence that at least the majority of these rearrangements are inversions. Most show clinal changes in frequency between habitats, suggestive of divergent selection, but only one appears to be fixed for different arrangements in the two habitats. Consistent with widespread evidence for balancing selection on inversion polymorphisms, we argue that a combination of heterosis and divergent selection can explain the observed patterns and should be considered in other systems spanning environmental gradients. This article is protected by copyright. All rights reserved

    Comparative mitogenomic analysis of three species of periwinkles: Littorina fabalis, L. obtusata and L. saxatilis

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    The flat periwinkles, Littorina fabalis and L. obtusata, offer an interesting system for local adaptation and ecological speciation studies. In order to provide genomic resources for these species, we sequenced their mitogenomes together with that of the rough periwinkle L. saxatilis by means of next-generation sequencing technologies. The three mitogenomes present the typical repertoire of 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and a putative control region. Although the latter could not be fully recovered in flat periwinkles using short-reads due to a highly repetitive fragment, in L. saxatilis this problem was overcome with additional long-reads and we were able to assemble the complete mitogenome. Both gene order and nucleotide composition are similar between the three species as well as compared to other Littorinimorpha. A large variance in divergence was observed across mitochondrial regions, with six- to ten-fold difference between the highest and the lowest divergence rates. Based on nucleotide changes on the whole molecule and assuming a molecular clock, L. fabalis and L. obtusata started to diverge around 0.8 Mya (0.4-1.1 Mya). The evolution of the mitochondrial protein-coding genes in the three Littorina species appears mainly influenced by purifying selection as revealed by phylogenetic tests based on dN/dS ratios that did not detect any evidence for positive selection, although some caution is required given the limited power of the dataset and the implemented approaches

    Using the SPM method to determine the convergence of rolled metal with textured polymer coatings

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    В данной работе на основе анализа сканов поверхности образца черепицы с полимерным покрытием была разработана слоевая модель текстурированного покрытия, проведены аналитические и компьютерные расчеты для этой модели в зависимости от ее параметров (концентрации пигментов, числа слоев, толщины покрытия и др.).In this paper, based on the analysis of the surface scans of a tile with a polymer coating, a layered model of a textured coating was developed, analytical and computer calculations were performed for this model, depending on its parameters (pigment concentration, number of layers, coating thickness, etc.)

    Problematic mobile phone use and smartphone addiction across generations: the roles of psychopathological symptoms and smartphone use

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    Contemporary technological advances have led to a significant increase in using mobile technologies. Recent research has pointed to potential problems as a consequence of mobile overuse, including addiction, financial problems, dangerous use (i.e. whilst driving) and prohibited use (i.e. use in forbidden areas). The aim of this study is to extend previous findings regarding the predictive power of psychopathological symptoms (depression, anxiety and stress), mobile phone use (i.e. calls, SMS, time spent on the phone, as well as the engagement in specific smartphone activities) across Generations X and Y on problematic mobile phone use in a sample of 273 adults. Findings revealed prohibited use and dependence were predicted by calls/day, time on the phone and using social media. Only for dependent mobile phone use (rather than prohibited), stress appeared as significant. Using social media and anxiety significantly predicted belonging to Generation Y, with calls per day predicted belonging to Generation X. This finding suggests Generation Y are more likely to use asynchronous social media-based communication, whereas Generation X engage more in synchronous communication. The findings have implications for prevention and awareness-raising efforts of possibly problematic mobile phone use for educators, parents and individuals, particularly including dependence and prohibited use

    Indiscriminate Males: Mating Behaviour of a Marine Snail Compromised by a Sexual Conflict?

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    Background: In promiscuous species, male fitness is expected to increase with repeated matings in an open-ended fashion (thereby increasing number of partners or probability of paternity) whereas female fitness should level out at some optimal number of copulations when direct and indirect benefits still outweigh the costs of courtship and copulation. After this fitness peak, additional copulations would incur female fitness costs and be under opposing selection. Hence, a sexual conflict over mating frequency may evolve in species where females are forced to engage in costly matings. Under such circumstance, if females could avoid male detection, significant fitness benefits from such avoidance strategies would be predicted. Methodology/Principal Findings: Among four Littorina species, one lives at very much higher densities and has a longer mating season than the other three species. Using video records of snail behaviour in a laboratory arena we show that males of the low-density species discriminate among male and female mucous trails, trailing females for copulations. In the high-density species, however, males fail to discriminate between male and female trails, not because males are unable to identify female trails (which we show using heterospecific females), but because females do not, as the other species, add a gender-specific cue to their trail. Conclusions/Significance: We conclude that there is likely a sexual conflict over mating frequency in the high-densit
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