160 research outputs found

    Chemical activation of aspenwood components in the production of thermomechanical pulp

    Get PDF
    The article represents the results of researches that allow to establish the appropriateness of usage of aspenwood modified by sodium monosulphite as a raw material for thermomechanical pulp (TMP) in newsprint production. Replacement of 30% of sprucewood by aspen using 1% consumption of sodium sulphite permits to achieve strength of samples of unbleached TMP 4510 m, which ensures the highest demands to newsprint. In this case the process of wood grinding accelerates and the reactivity of hemicelluloses and lignin increases

    Technology for Creation and Detailed Analysis of Polymer Composites with Uniform Distribution of Quantum Dots and Liquid Crystals

    Get PDF
    One of the most actual tasks in biotechnology is the creation of a new generation of nanobiosensors with improved brightness, photo stability, and sensitivity. Compositions of polymers and colloidal quantum dots (QDs) are the most promising base to develop such sensors. This work presents the technology for creation and detailed analysis of nanostructured composite films based on polypropylene matrices with uniformly distributed CdSe/ZnS quantum dots and liquid crystals. Methods of optical microscopy, scanning probe microscopy and confocal fluorescen tmicrospectroscopy were used. The presence of liquid crystals in the composite allows additional control of QDs fluorescence. The methodology proposed is applicable not only to polypropylene, but also to other porous polymers. The results of this work indicate the possibility of creating high-quality polymer/QDs composite materials and open the way to the development of nanomaterials (nanosensors) with optical properties sensitive to various environmental parameters (electric field, photo irradiation, mechanical action, etc.). Keywords: quantum dot-polymer composites, nanoporous polypropylene, fluorescenc

    Empathy parameters as a factor of integration of students’ social tolerance

    Full text link
    Currently, various conflicts often arise that contribute to the destabilization and separation of society. The question arises: how to consolidate social relations in the educational environment, how to avoid aggression and bullying, social isolation and similar problems? Empathic abilities have traditionally been considered a means of increasing tolerance in society. The paper considers the ambiguous contribution of empathy parameters to the manifestation of social tolerance of students. Only the conative parameters of empathy are a factor of integration, i. e. student cohesion, unlike empathy channels, which are not related to the social tolerance of students.В настоящее время часто возникают разнообразные конфликты, способствующие дестабилизации и разъединению общества. Возникает вопрос: как сплотить социальные отношения в образовательной среде, как избежать агрессии и буллинга, социальной изоляции и подобных проблем? Эмпатические способности традиционно считались средством увеличения толерантности в обществе. В работе рассматривается неоднозначный вклад параметров эмпатии в проявление социальной толерантности студентов. Лишь конативные параметры эмпатии являются фактором интеграции, т. е. сплочения студентов, в отличие от каналов эмпатии, которые не связаны с социальной толерантностью студентов

    Chemically modified mechanical pulp of wood chips of different breeds

    Get PDF
    The results of studies that allow to establish the feasibility of using a modified aspen wood as a raw material for thermomechanical pulp (TMP) in the production of newsprint. Modification of wood chips can increase the proportion of aspen wood in combination with spruce up to 30% without reducing the strength of quality newsprint. When this process is accelerated and the grinding timber increases reactivity of hemicelluloses and lignin, but also leads to lower energy consumption

    Technology features of fuel pellets from deciduous wood

    Get PDF
    The present researches are aimed at studying the physical and mechanical properties of pellets produced from hardwood. For the experiment black alder and birch widespread on the territory of the Republic of Belarus hardwood timber has been chosen. It is stated that the use of wood in an unaltered form is impractical because the pellets derived from them have a low mechanical strength. The technological solution of this problem was the treatment of crushed wood raw material by saturated steam. The results of industrial tests confirmed that wood particles activation of hardwood fuel pellets gives the required quality standard. Technical feature of the technology is the use of a matrix with the length of the pressing channel 33 mm

    Influence of the substrate-induced strain and irradiation disorder on the Peierls transition in TTF-TCNQ microdomains

    Full text link
    The influence of the combined effects of substrate-induced strain, finite size and electron irradiation-induced defects have been studied on individual micron-sized domains of the organic charge transfer compound tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) by temperature-dependent conductivity and current-voltage measurements. The individual domains have been isolated by focused ion beam etching and electrically contacted by focused ion and electron beam induced deposition of metallic contacts. The temperature-dependent conductivity follows a variable range hopping behavior which shows a crossover of the exponent as the Peierls transition is approached. The low temperature behavior is analyzed within the segmented rod model of Fogler, Teber and Shklowskii, as originally developed for a charge-ordered quasi one-dimensional electron crystal. The results are compared with data obtained on as-grown and electron irradiated epitaxial TTF-TCNQ thin films of the two-domain type

    Complex biochemical characteristics of <i>Coriandrum sativum</i> L.

    Get PDF
    Background.  Coriandrum sativum L. is a valuable vegetable crop with early maturity and high nutritional benefits. Green biomass of coriander is rich in vitamins, especially ascorbic acid and carotene. The feasibility of using coriander as a natural food additive is due to its high antioxidant activity. The aim of this research was to study the biochemical composition of the green biomass in the accessions of C. sativum from the VIR global collection and identify promising accessions for use in breeding for quality.Materials and methods. The green biomass of  67 coriander accessions from different countries maintained in the VIR collection served as the research material. The study was carried out according to the guidelines developed by VIR.Results. As a result of the study, the feasibility of using C. sativum as a source of bioactive compounds was theoretically justified and experimentally confirmed, thus attesting to the prospects of coriander accessions from the VIR collection for quality-targeted breeding programs. New data were obtained on the biochemical composition of coriander green biomass. A factor determining such biochemical composition is the genotypic features of coriander associated with its origin. Biochemical parameters in coriander varied significantly depending on the origin of an accession. The highest variability was observed in the content of carotenes (CV 41%). The effect of an accession’s precocity was not confirmed. Sources for individual quality indicators were highlighted.Conclusion. Accessions with an optimal component composition for a balanced human diet were identified and recommended for quality-oriented breeding, including the development of cultivars for health-friendly, curative and preventive nutrition. The selected accessions are of interest as source material for breeding programs and practical utilization

    Neoglycolipids Micelle-like Structures as a Basis for Drug Delivery Systems

    Get PDF
    Targeted drug delivery is one of the most promising tasks of nanomedicine, as this is a real way to increase the effectiveness of therapeutic effects against many diseases. In this regard, the development of new inexpensive highly effective stimulating and non-immunogenic drug delivery systems (DDS) is of great importance. In this work new molecular candidates were proposed and studied for the creation of such systems based on the use of new compounds, neoglycolipids. It is shown that these compounds are capable of self-association in aqueous solutions and can serve as potential carriers of drug compounds with targeted delivery determined by their terminal groups (in particular, glycans). The processes of their associates formation and features of their structure are investigated. The results show that these selforganizing nanoscale systems can be used as a basis for developing new drug delivery systems. Keywords: neoglycolipids, micelle-like structures, small-angle X-ray scattering, molecular dynamics simulatio
    corecore