Determination of electric and dielectric conductivity of fruits and vegetables

The article describes the research results to determine fruits and vegetables’ electrical and dielectric conductivity. The electrical conductivity is characterized, and the experimental method of its determination and the equipment used are given. Also, the topic’s relevance, keywords, methods of calculation in the experimental process, the electrical conductivity of crushed, cut varieties of fruits (apricots, apples, plums) and carrots, and the results of a study to determine the dielectric constant. MevaThe results of the dielectric properties of tula and cut varieties of different sizes (apricots, apples, plums) and vegetables (carrots, potatoes, beets, and onions) are presented. The curves of the dependence of the specific electrical conductivity of crushed fruits, plums, apples, and carrots on the EMF voltage are obtained. The specific electrical conductivity at cm is a maximum of 0.191 cm / m. Also, during the operation of the electrodes in the cell -30 s, the electrical conductivity first increases rapidly; after 10 seconds, the growth decreases, and at a certain maximum time - 18 s decreases, and the maximum size here is in the range of 0.209 to 0.230 cm/cm. The temperature dependence of the specific electrical conductivity of fruits and vegetables greatly affects their temperature on electrical conductivity

Open-hole well completion analysis using borehole acoustic scanner and an optical borehole televiewer

This paper presents a method for an open-hole well completion analysis using a Borehole Acoustic Scanner and a Borehole Video Imager. Acoustic ultrasonic scanning has been used for lithological well profile analysis, cavernous and fractured-cavernous zones identification in a testing well. The video imager provides important information about the well geological structure and fractured zones. It is shown that the combined interpretation of the borehole acoustic scanner data and video imager data provides complete geological information about the testing well. Corresponding approach could be useful for developing acoustic scanning template database

Toward the Asphaltene Structure by Electron Paramagnetic Resonance Relaxation Studies at High Fields (3.4 T)

© 2016 American Chemical Society.A series of 12 asphaltene samples extracted from heavy oils and the oxidized bitumen of different origin has been studied with high-frequency W-band (94 GHz) pulsed electron paramagnetic resonance (EPR) spectroscopy. Transverse (T2e) and longitudinal (T1e) relaxation times of the free radical (FR) and the vanadyl porphyrin (VO2+) were measured for each sample. A significant contribution of the spectral diffusion to T2e has been revealed and ascribed to the dipole-dipole interaction between the FR and VO2+. This indicates that the distance between the FR and VO2+ does not exceed a few nanometers, which means, in turn, that VO2+ can participate in construction of the asphaltene aggregates via the intermolecular interactions

Modeling of complex oxide materials from the first principles: systematic applications to vanadates RVO3 with distorted perovskite structure

"Realistic modeling" is a new direction of electronic structure calculations, where the main emphasis is made on the construction of some effective low-energy model entirely within a first-principle framework. Ideally, it is a model in form, but with all the parameters derived rigorously, on the basis of first-principles electronic structure calculations. The method is especially suit for transition-metal oxides and other strongly correlated systems, whose electronic and magnetic properties are predetermined by the behavior of some limited number of states located near the Fermi level. After reviewing general ideas of realistic modeling, we will illustrate abilities of this approach on the wide series of vanadates RVO3 (R= La, Ce, Pr, Nd, Sm, Gd, Tb, Yb, and Y) with distorted perovskite structure. Particular attention will be paid to computational tools, which can be used for microscopic analysis of different spin and orbital states in the partially filled t2g-band. We will explicitly show how the lifting of the orbital degeneracy by the monoclinic distortion stabilizes C-type antiferromagnetic (AFM) state, which can be further transformed to the G-type AFM state by changing the crystal distortion from monoclinic to orthorhombic one. Two microscopic mechanisms of such a stabilization, associated with the one-electron crystal field and electron correlation interactions, are discussed. The flexibility of the orbital degrees of freedom is analyzed in terms of the magnetic-state dependence of interatomic magnetic interactions.Comment: 23 pages, 13 figure

Quantum Transport in Ladder-Type Networks: Role of nonlinearity, topology and spin

We investigate quantum transport of electrons, phase solitons, etc. through mesoscopic networks of zero-dimensional quantum dots. Straight and circular ladders are chosen as networks with each coupled with three semi-infinite leads (with one incoming and the other two outgoing). Two transmission probabilities (TPs) as a function of the incident energy $\epsilon$ show a transition from anti-phase aperiodic to degenerate periodic spectra at the critical energy $\epsilon_c$ which is determined by a bifurcation point of the bulk energy dispersions. TPs of the circular ladder depend only on the parity of the winding number. Introduction of a single missing bond (MB) or missing step doubles the period of the periodic spectra at $\epsilon>\epsilon_c$ . Shift of the MB by lattice constant results in a striking switching effect at $\epsilon<\epsilon_c$. In the presence of the electric-field induced spin-orbit interaction (SOI), an obvious spin filtering occurs against the spin-unpolarized injection. Against the spin-polarized injection, on the other hand, the spin transport shows spin-flip (magnetization reversal) oscillations with respect to SOI. We also show a role of soliton in the context of its transport through the ladder networks.Comment: 10 pages, 16 figure

Seasonal changes in chlorophyll and carotenoid content in needles of scots pines (pinus sylvestris l.) Exposed to the thermal field of a gas flare

Seasonal changes in chlorophyll (Chl) and carotenoid (Car) content were analyzed in needle samples from young Scots pines (Pinus sylvestris L.) growing in the thermal field zone at various distances from the petroleum gas flare. Experiments were performed in Khanty Mansi Autonomous Area (Yugra) of Russia throughout the autumn–winter–spring period. Two hypotheses were subject to verification: (1) the thermal field of petroleum gas combustion flame imitates the influence of climate warming on plants, thus affecting the pigment complex of the photosynthetic apparatus (PSA) in pine needles; (2) transformations of PSA pigment complex in pine needles throughout the autumn–winter–spring period are sensitive to a long-term rise in ambient temperature by 1–2°С. In the winter period, the seasonal dynamics of certain PSA parameters comprised maxima and minima that are supposedly due to the regulation of Chl and Car content upon changes in air temperature. In trees growing under divergent thermal conditions, seasonal changes of these parameters were not synchronous. Analysis of seasonal changes revealed that winter-related transformations of the PSA structural–functional condition in needles are subject to consistent variations at different distances from the gas flame. The PSA activity of needles throughout the studied period was higher near the flame and decreased with the distance from the gas flare. When Chl content in needles decreased in autumn–winter, the smallest reduction was observed in the location near the gas flare (site I) where temperature was 1–2°C higher than the background level. The intermediate decrease in pigment content was noted at a moderate distance from the flame (site III), while the most pronounced decrease occurred at the largest distance from the gas flare (site VII). At the same time, the Chl a/b content ratio in needles was consistently lower for trees located at site I than at site VII. Hence, the amount of light-harvesting complexes in chloroplasts from trees grown at site I was higher than the amount of photosystems in the same chloroplasts. The Chl (a + b)/Car ratio in needles of trees grown near the gas flare (site I) was higher than in locations III and VII. This ratio displayed two significant peaks in the winter dynamics, which was supposedly due to the sufficient preservation of green pigments. Divergent seasonal changes in Chl and Car content and their dissimilar correlations with air temperature indicate that the pools of these pigments are controlled by different mechanisms. The actual Chl content, determined by the balance of pigment degradation and synthesis, should depend on the environmentally modified Chl synthesis and on the protective function of Car. Photosynthesizing cells produce additional amounts of carotenoids during autumn–winter, thus preventing the photodegradation of Chl in the period from autumn to late spring. © 2021, Pleiades Publishing, Ltd.This work was supported by the Comprehensive Program of the Ural Branch of the Russian Academy of Sciences for 2018–2020 (project no. 18-4-4-10) and by a state assignment to the Institute Botanic Garden of the Ural Branch of the Russian Academy of Sciences

Magnetoelectric Properties of Zinc-Substituted BiFeO3 Multiferroics

The magnetoelectric properties of ceramic samples of BiFe1–xZnxO3 and Bi1–xZnxFe1–xZnxO3 multiferroics have been studied in magnetic fields from 0 to 80 kOe at room temperature. All the samples have the linear dependences of magnetoelectric coefficient αME with low hump-like maxima of αME at 10 kHz and also at 85 kHz. These magnetoelectric studies of the bismuth ferrites with doubly substituted Zn show that the double substitution of Zn2+ ions for Bi3+ and Fe3+ ions does not lead to desired enhancement of the mag- netoelectric properties as compared with the ordinary substitution of Zn2+

A glimpse on Staphylococcus aureus translation machinery and its control

© 2016, Pleiades Publishing, Inc.Staphylococcus aureus is a major opportunistic and versatile pathogen. Because the bacteria rapidly evolve multi-resistances towards antibiotics, there is an urgent need to find novel targets and alternative strategies to cure bacterial infections. Here, we provide a brief overview on the knowledge acquired on S. aureus ribosomes, which is one of the major antibiotic targets. We will show that subtle differences exist between the translation at the initiation step of Gram-negative and Gram-positive bacteria although their ribosomes display a remarkable degree of resemblance. In addition, we will illustrate using specific examples the diversity of mechanisms controlling translation initiation in S. aureus that contribute to shape the expression of the virulence factors in a temporal and dynamic manner

Structural Insights into the Role of Diphthamide on Elongation Factor 2 in mRNA Reading-Frame Maintenance

© 2018 Elsevier Ltd One of the most critical steps of protein biosynthesis is the coupled movement of mRNA, which encodes genetic information, with tRNAs on the ribosome. In eukaryotes, this process is catalyzed by a conserved G-protein, the elongation factor 2 (eEF2), which carries a unique post-translational modification, called diphthamide, found in all eukaryotic species. Here we present near-atomic resolution cryo-electron microscopy structures of yeast 80S ribosome complexes containing mRNA, tRNA and eEF2 trapped in different GTP-hydrolysis states which provide further structural insights into the role of diphthamide in the mechanism of translation fidelity in eukaryotes

Heat capacity of nanostructured multiferroics BiFe1–x Zn x O3

The heat capacity of ceramic BiFe1–x Zn x O3 multiferroics has been studied in the temperature range 150–750 K. It is found that the antiferromagnetic transition temperature T N slightly shifts to lower temperatures as the concentration of the substitutional impurity Zn increases. An excess heat treatment has been observed; it is considered as the Schottky anomaly in three-level states