208 research outputs found

    Сучасний зміст зносу та амортизації як об’єктів бухгалтерського обліку

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    У статті розглянуто економічну сутність категорій «амортизація» та «знос» як об’єктів бухгалтерського обліку.In the article economic essence of categories of depreciation is considered as objects of accountingВ статье рассмотрена экономическая сущность категорий «амортизация» и «износ» как объектов бухгалтерского учета

    Antibodies to myofibril antigens in cosmonauts after spaceflights

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    Serum samples obtained from 15 astronauts before and after spaceflights were studied with the use of the indirect immunofluorescent method. In seven astronauts antibodies to different elements of the human heart muscle appeared after flights. Strong and very strong luminescence of the elements of heart muscle tissue was detected in the astronauts after the third space flight. In a study of the sera on sections of bovine heart muscle tissue the reactions of the sera taken before and after flight were found to show no essential differences

    Selectively Tunable Luminescence of Perovskite Nanocrystals Embedded in Polymer Matrix Allows Direct Laser Patterning

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    Cesium lead halide perovskite nanocrystals (NCs) have gained enormous attention as promising light-emitting and light-converting materials. Most of their applications require embedding NCs in various matrices, which is a challenging task due to their low stability, especially in the case of red-emitting CsPbI3 NCs. In this work, a new approach is proposed allowing the formation of red-emitting perovskite NCs by anion exchange induced directly inside a solid polymer matrix using green-emitting CsPbBr3 NCs as templates and iodododecane as an iodine source. Moreover, a simple and efficient route to photo-assisted termination of the anion exchange reaction in the polymer composite after reaching desired optical properties is demonstrated. The findings allow the authors to pattern a thin composite film with an ultrashort UV laser resulting in a selective generation of green- and red-emitting features with a 15 µm resolution

    Lewis acid complexes: synthesis and application in polymerization processes

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    The published works by the present authors on the synthesis of organoaluminium compounds and complexes there of are summarized. The study of the reactivity of these latter in stereospecific and alternating polymerization made it possible to produce effective catalysts for synthe-sizing superhigh molecular weight polyolefins, alternating copolymers. The detailed investigation of the properties of the organoaluminium complexes with ethers allowed working out new catalytic systems capable of initiating styrene living cationic polymerization. The revealed regularities of living polymerization of styrene allows to realize for the first time the controlled polymerization of industrial C9-fraction, with the obtained results being used for developing technology for production of aromatic hydrocarbon resins from C9-fraction. An industrial process was developed and employed to produce oligopiperylene and aromatic hydrocarbon resins, which are used as film-forming components in paint and varnish compositio

    Colloidal Nanocrystals Embedded in Macrocrystals: Robustness, Photostability, and Color Purity

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    Cataloged from PDF version of article.The incorporation of colloidal quantum dots (QDs) into ionic crystals of various salts (NaCl, KCl, KBr, etc.) is demonstrated. The resulting mixed crystals of various shapes and beautiful colors preserve the strong luminescence of the incorporated QDs. Moreover, the ionic salts appear to be very tight matrices, ensuring the protection of the QDs from the environment and as a result providing them with extraordinary high photo- and chemical stability. A prototype of a white light-emitting diode (WLED) with a color conversion layer consisting of this kind of mixed crystals is demonstrated. These materials may also find applications in nonlinear optics and as luminescence standards

    Bio-nanohybrids of quantum dots and photoproteins facilitating strong nonradiative energy transfer

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    Cataloged from PDF version of article.Utilization of light is crucial for the life cycle of many organisms. Also, many organisms can create light by utilizing chemical energy emerged from biochemical reactions. Being the most important structural units of the organisms, proteins play a vital role in the formation of light in the form of bioluminescence. Such photoproteins have been isolated and identified for a long time; the exact mechanism of their bioluminescence is well established. Here we show a biomimetic approach to build a photoprotein based excitonic nanoassembly model system using colloidal quantum dots (QDs) for a new bioluminescent couple to be utilized in biotechnological and photonic applications. We concentrated on the formation mechanism of nanohybrids using a kinetic and thermodynamic approach. Finally we propose a biosensing scheme with an ON/OFF switch using the QD-GFP hybrid. The QD-GFP hybrid system promises strong exciton-exciton coupling between the protein and the quantum dot at a high efficiency level, possessing enhanced capabilities of light harvesting, which may bring new technological opportunities to mimic biophotonic events

    Application of remote monitoring and ground-based sensing in pastoralism

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    The development and implementation of an innovative system applying digital aerospace technologies in pastoralism constitute one of the current trends in agricultural development designed to solve numerous problems associated with soil fertility restoration in grazing pastures. Here, a promising line of research is to explore the feasibility of using satellite systems for an overall nutrient yield assessment per hectare of grazing land. The present article describes a comprehensive approach to the optimization of pastoralism that is based on remote methods for assessing pasture fertility using unmanned aerial vehicles (UAVs) and artificial Earth satellites. An analysis of existing methodological approaches reveals that the formalization of prediction processes is complicated by the lack of a theoretical basis for creating appropriate model-algorithmic support. The data on vegetation index dynamics and the nutritional values of forage plants obtained by interpreting imagery from a UAV camera and the multispectral cameras of a satellite service, as well as data from a portable handheld nitrogen sensor, were compared with the actual nutritional values of pasture plants. The study results provide a means to optimize the grouping of grazing animals, taking into account the actual possibility of achieving an increase in live weight. The provided findings indicate the possibility of achieving an additional 11.06% increase in daily live weight gain in young sheep (Jalgin Merino) when keeping them in pasture areas having a vegetation index of at least 0.5. Remote monitoring based on satellite service allows more efficient use of pastures. Study shows a positive relationship between remote sensing NDVI and feed nutritional value. Animal grazing optimization provides an additional 11.06% increase in live weight gain

    Function of the ribosomal E-site: a mutagenesis study

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    Ribosomes synthesize proteins according to the information encoded in mRNA. During this process, both the incoming amino acid and the nascent peptide are bound to tRNA molecules. Three binding sites for tRNA in the ribosome are known: the A-site for aminoacyl-tRNA, the P-site for peptidyl-tRNA and the E-site for the deacylated tRNA leaving the ribosome. Here, we present a study of Escherichia coli ribosomes with the E-site binding destabilized by mutation C2394G of the 23S rRNA. Expression of the mutant 23S rRNA in vivo caused increased frameshifting and stop codon readthrough. The progression of these ribosomes through the ribosomal elongation cycle in vitro reveals ejection of deacylated tRNA during the translocation step or shortly after. E-site compromised ribosomes can undergo translocation, although in some cases it is less efficient and results in a frameshift. The mutation affects formation of the P/E hybrid site and leads to a loss of stimulation of the multiple turnover GTPase activity of EF-G by deacylated tRNA bound to the ribosome

    Flexible and fragmentable tandem photosensitive nanocrystal skins

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    We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the currentmatching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of single monolayers of colloidal water-soluble CdTe and CdHgTe nanocrystals (NCs) in adjacent junctions on a Kapton polymer tape. Owing to the usage of a single NC layer in each junction, noise generation was significantly reduced while keeping the resulting PNS films considerably transparent. In each junction, photogenerated excitons are dissociated at the interface of the semi-transparent Al electrode and the NC layer, with holes migrating to the contact electrode and electrons trapped in the NCs. As a result, the tandem PNSs lead to an open-circuit photovoltage buildup equal to the sum of those of the two single junctions, exhibiting a total voltage buildup of 128.4 mV at an excitation intensity of 75.8 μW cm⁻² at 350 nm. Furthermore, we showed that these flexible PNSs could be bent over 3.5 mm radius of curvature and cut out in arbitrary shapes without damaging the operation of individual parts and without introducing any significant loss in the total sensitivity. These findings indicate that the NC skins are promising as building blocks to make low-cost, flexible, large-area UV/visible sensing platforms with highly efficient full-spectrum conversion

    ВИКОРИСТАННЯ МЕТОДІВ МАТЕМАТИЧНОГО МОДЕЛЮВАННЯ ДЛЯ ПІДВИЩЕННЯ ЕФЕКТИВНОСТІ ЕКСТРАКОРПОРАЛЬНОГО ЗАПЛІДНЕННЯ. ПОСТАНОВКА ПРОБЛЕМИ

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    There were presented the results of patterning a mathematical multifactor model of efficiency of the method of extracorporal fertilization.Представлена классификация методов математического моделирования, используемых для повышения эффективности экстракорпорального оплодотворения. Проанализированы результаты использования подобных моделей.Представлена класифікація методів математичного моделювання, що використовуються для підвищення ефективності екстракорпорального запліднення. Проаналізовані результати застосування подібних моделей
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