The hydration numbers of perchloric acid were calculated using the Raoult law. The initial simplificated model is based on the hypothesis of the free water mole fraction equality to the water ...activity. A cause-effect relation has been established between the violation of this law and the distortion of the hydration numbers curve at low concentrations. In addition, this model was found unsatisfactory for evaluation of the solute activity coefficients. The more sophisticated model has been proposed for the calculations of hydration numbers, free water mole fraction and solute activity coefficients. Its main feature is the use of the free water activity coefficient. Estimated values of this coefficient differ from the unity in a small degree.
Precise measurements of the time-dependent intensity of the low-energy (<50 GeV) galactic cosmic rays (GCRs) are fundamental to test and improve the models that describe their propagation inside the ...heliosphere. In particular, data spanning different solar activity periods, i.e., from minimum to maximum, are needed to achieve comprehensive understanding of such physical phenomena. The minimum phase between solar cycles 23 and 24 was peculiarly long, extending up to the beginning of 2010 and followed by the maximum phase, reached during early 2014. In this Letter, we present proton differential spectra measured from 2010 January to 2014 February by the PAMELA experiment. For the first time the GCR proton intensity was studied over a wide energy range (0.08-50 GeV) by a single apparatus from a minimum to a maximum period of solar activity. The large statistics allowed the time variation to be investigated on a nearly monthly basis. Data were compared and interpreted in the context of a state-of-the-art three-dimensional model describing the GCRs propagation through the heliosphere.
This paper describes the current understanding of the interaction between geospheres from a complex set of physical and chemical processes under the influence of ionization. The sources of ionization ...involve the Earth’s natural radioactivity and its intensification before earthquakes in seismically active regions, anthropogenic radioactivity caused by nuclear weapon testing and accidents in nuclear power plants and radioactive waste storage, the impact of galactic and solar cosmic rays, and active geophysical experiments using artificial ionization equipment. This approach treats the environment as an open complex system with dissipation, where inherent processes can be considered in the framework of the synergistic approach. We demonstrate the synergy between the evolution of thermal and electromagnetic anomalies in the Earth’s atmosphere, ionosphere, and magnetosphere. This makes it possible to determine the direction of the interaction process, which is especially important in applications related to short-term earthquake prediction. That is why the emphasis in this study is on the processes proceeding the final stage of earthquake preparation; the effects of other ionization sources are used to demonstrate that the model is versatile and broadly applicable in geophysics.
β-(1→3)-D-Glucan is an essential component of the fungal cell wall. Mouse monoclonal antibodies (mAbs) against synthetic nona-β-(1→3)-D-glucoside conjugated with bovine serum albumin (BSA) were ...generated using hybridoma technology. The affinity constants of two selected mAbs, 3G11 and 5H5, measured by a surface plasmon resonance biosensor assay using biotinylated nona-β-(1→3)-D-glucan as the ligand, were approximately 11 nM and 1.9 nM, respectively. The glycoarray, which included a series of synthetic oligosaccharide derivatives representing β-glucans with different lengths of oligo-β-(1→3)-D-glucoside chains, demonstrated that linear tri-, penta- and nonaglucoside, as well as a β-(1→6)-branched octasaccharide, were recognized by mAb 5H5. By contrast, only linear oligo-β-(1→3)-D-glucoside chains that were not shorter than pentaglucosides (but not the branched octaglucoside) were ligands for mAb 3G11. Immunolabelling indicated that 3G11 and 5H5 interact with both yeasts and filamentous fungi, including species from Aspergillus, Candida, Penicillium genera and Saccharomyces cerevisiae, but not bacteria. Both mAbs could inhibit the germination of Aspergillus fumigatus conidia during the initial hours and demonstrated synergy with the antifungal fluconazole in killing C. albicans in vitro. In addition, mAbs 3G11 and 5H5 demonstrated protective activity in in vivo experiments, suggesting that these β-glucan-specific mAbs could be useful in combinatorial antifungal therapy.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Turbulent swirling gas flows in the flow around obstacles in the ventilation system and in the intermachine space are studied. In the development of mathematical decomposition, the effectiveness of ...developing a spatial decomposition of the ventilation for ship and industrial installations, as well as the application of this technology, is shown.
Relevance. The need to analyze the current state of the subject of coal drying in order to identify the most effective methods in terms of time and energy costs, as well as environmental safety and ...improve the quality of fuel. As practice shows, drying is one of the most important stages in coal preparation for combustion, it helps to increase thermal efficiency, reduce emissions and environmental pollution, increase energy capacity and improve combustion stability. Among the main methods of drying coal, drying with evaporation: A) rotary drying; B) drying in a fluidized bed; C) immersion drying with hot oil; D) drying in a microwave oven, as well as drying without evaporation: A) hydrothermal dehydration; B) mechanical/thermal dehydration; C) solvent extraction, can be distinguished. At the same time, each of these methods is constantly evolving and it is required to evaluate the influence of the dynamics of these changes on the key characteristics of drying. Aim. Review and analysis of modern methods of coal drying, the most efficient in terms of time and energy costs. Object. Wet material – coal, subjected to various drying methods. Methods. Search for works on the stated topic, checking the indication of the main drying parameters: time, energy consumption, etc. Based on the data obtained, a comparison of various drying methods was carried out, and optimal methods were recommended. Results. The authors have considered the modern methods of drying coal and assessed their effectiveness. Rotary drying, hot oil immersion drying, mechanical/thermal dehydration and solvent extraction were found to be the most energy efficient methods for drying coal. The paper considers the features of each drying method.
Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic ...rays in our Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 gigavolt to 1.2 teravolts performed by the satellite-borne experiment PAMELA (payload for antimatter matter exploration and light-nuclei astrophysics). We find that the spectral shapes of these two species are different and cannot be described well by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data.
Searches for the anisotropy of the total electron and positron fluxes in high-energy galactic cosmic rays are performed. Data collected by the PAMELA magnetic spectrometer from June 2006, when it was ...launched into Earth’s orbit, to 2016 were used for the respective analysis. The main event selection and a determination of particle arrival directions were accomplished by means of a position-sensitive microstrip calorimeter. A neutron detector was used to suppress additionally the background of protons and nuclei. An analysis of information obtained over a nearly ten-year period of measurements made it possible to set upper limits on the amplitude of the dipole anisotropy of the total electron and positron fluxes for two energy ranges, between 25 and 100 GeV and between 100 GeV and 1 TeV. These results supplement data from other satellite-borne experiments, AMS-02 and Fermi.
Nafion-NH4+ membranes plasticized with dimethyl sulfoxide (DMSO and DMSO-d6) have been investigated at room temperature using the vacuum ATR-FTIR and FTIR absorption spectroscopic technique in the ...range 50–4000 cm−1. The amount of the plasticizer corresponds to the molecular ratio n = DMSO/NH4+ = 2.7–13.8. The mutual association of free DMSO molecules in Nafion leads to appearance of weak band at 86 cm−1 assigned to dipole-dipole interactions. Also the Raman spectra of dry Nafion-NH4+ membranes were investigated.
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•Solvation process by DMSO is a first stage of the Nafion-NH4+ membrane plasticization.•The degrees of DMSO molecule polarization by the NH4+ and Li+ cations are commensurate.•The NH3 + H+ interaction weakens sharp the H-bond between H+ and the DMSO molecules.•Similarity of the Nafion-NH4+ and PTFE fluorocarbon chains is shown.
The cell wall of opportunistic pathogenic yeast fungi Candida and mould fungi Aspergillus is highly important for the pathogenesis of fungal infections, as it is the first to interact with the cells ...of the host organism, is responsible for pathogen adhesion and intra- and intercellular communications and bears important antigenic determinants. Fungal cell walls are composed mainly of polysaccharides. Methods that are currently used to study biological functions of cell wall polysaccharides require samples that are structurally characterized and have sufficient homogeneity and purity. However, the isolation of such samples from fungal cultures is often poorly feasible. Therefore, synthetic oligosaccharides of strictly specified structure corresponding to polysaccharide fragments of the cell wall of pathogenic fungi are indispensable tools for investigating the biological functions of such compounds. The review surveys studies devoted to the synthesis of oligosaccharides corresponding to fragments of major polysaccharide components of the fungal cell wall of Candida and Aspergillus: mannan, α- and β-(1→3)-glucans, chitin, galactosaminogalactan and galactomannan. The bibliography includes 140 references.
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