Computer Simulation of Stress-Strain State of Oil Gathering Pipeline Designed for Ugut Field

The paper presents the stress and strain state modeling of infield pipeline in Ugut oil field. The finite element models of the stress field distribution in the pipeline wall are presented in this paper. The attention is paid to the pipeline reliability under stress conditions induced by the internal pressure and external compressive or tensile loads

Mathematical modeling of the crystallization process to obtain a fine fraction aluminates

© Published under licence by IOP Publishing Ltd. Considered process of melt crystallization of the material in a twin-roll mold. Resolved an important problem of heat conduction through the wall of variable thickness, using the Fourier method and theorem Duhamel. Obtain theoretical dependence of the thickness of a frozen layer on the physical parameters of the melt and technological parameters of the crystallization process

Comparative chloroplast genomics and phylogenetics of Fagopyrum esculentum ssp. ancestrale – A wild ancestor of cultivated buckwheat

<p>Abstract</p> <p>Background</p> <p>Chloroplast genome sequences are extremely informative about species-interrelationships owing to its non-meiotic and often uniparental inheritance over generations. The subject of our study, <it>Fagopyrum esculentum</it>, is a member of the family Polygonaceae belonging to the order Caryophyllales. An uncertainty remains regarding the affinity of Caryophyllales and the asterids that could be due to undersampling of the taxa. With that background, having access to the complete chloroplast genome sequence for <it>Fagopyrum </it>becomes quite pertinent.</p> <p>Results</p> <p>We report the complete chloroplast genome sequence of a wild ancestor of cultivated buckwheat, <it>Fagopyrum esculentum </it>ssp. <it>ancestrale</it>. The sequence was rapidly determined using a previously described approach that utilized a PCR-based method and employed universal primers, designed on the scaffold of multiple sequence alignment of chloroplast genomes. The gene content and order in buckwheat chloroplast genome is similar to <it>Spinacia oleracea</it>. However, some unique structural differences exist: the presence of an intron in the <it>rpl2 </it>gene, a frameshift mutation in the <it>rpl23 </it>gene and extension of the inverted repeat region to include the <it>ycf1 </it>gene. Phylogenetic analysis of 61 protein-coding gene sequences from 44 complete plastid genomes provided strong support for the sister relationships of Caryophyllales (including Polygonaceae) to asterids. Further, our analysis also provided support for <it>Amborella </it>as sister to all other angiosperms, but interestingly, in the bayesian phylogeny inference based on first two codon positions <it>Amborella </it>united with Nymphaeales.</p> <p>Conclusion</p> <p>Comparative genomics analyses revealed that the <it>Fagopyrum </it>chloroplast genome harbors the characteristic gene content and organization as has been described for several other chloroplast genomes. However, it has some unique structural features distinct from previously reported complete chloroplast genome sequences. Phylogenetic analysis of the dataset, including this new sequence from non-core Caryophyllales supports the sister relationship between Caryophyllales and asterids.</p

Reactions of vinylphosphonates with piperazines

© 2017, Pleiades Publishing, Ltd. Dialkyl [2-(piperazin-1-yl)ethyl]phosphonates were obtained by the reactions of piperazine with dialkyl vinylphosphonates. The addition of 2-(piperazin-1-yl)ethanamine to diethyl vinylphosphonate involves the primary exocyclic amino group of the heterocyclic compound

Self-diffusion of molecules in aqueous solutions of tetramethylurea

Solutions of tetramethylurea (I) in light and heavy water were studied by the proton spin echo method over a wide concentration range at different temperatures. The energies of self-diffusion activation for species in these systems were calculated. In the both systems, the lowest coefficient of self-diffusion and the highest energy of activation for all the temperatures studied (288 to 313 K) were found for its ∼20 mol % solution, which corresponds to a congruently melting compound in the solid phase and to maximum sound viscosity, density, and speed in aqueous solutions of tetramethylurea. The low-concentration range of compound I (from 1.2 to 5 mol %) proved to be featureless

Numerical analysis of temperature distribution in bottom electrode of DC arc furnace in process

© 2014 Irek Husnemardanovich Israphilovet et al. Conducted comprehensive studies of the existing thermal bottom electrode (BE) in process. Considered separately BE coolant. The optimum parameters of copper BE (water-coolant, wall temperatures and geometric parameters) under specific operating conditions calculated

Contribution of Ryanodine Receptors in Forming Presynaptic Ca²⁺ Level and Cholinergic Modulation in Response to Single Potential in Frog Neuromuscular Junction

© 2016, Springer Science+Business Media New York.Ca2+ entering through voltage-gated Ca2+ channels plays a key role in the initiation of neurotransmitter secretion. However, intracellular Ca2+ storages such as endoplasmic reticulum (ER) can also contribute in the presynaptic Ca2+ level forming. Also ryanodine-dependent Ca2+-induced Ca2+ channels of endoplasmic reticulum may contribute in secretion inhibiting action of cholinomimetics. In this work, we use a photometric method for estimating the relative change in the level of presynaptic Ca2+ ions (Ca2+ transient). We have shown that during low-frequency stimulation Ca2+ release from the ER is involved in forming of presynaptic Ca2+ level. And more likely those effects of the cholinomimetics on Ca2+ transient are not related to Ca2+ release from the endoplasmic reticulum

Hybrid welding of dissimilar metals

© Published under licence by IOP Publishing Ltd.The article addresses issues laser - plasma welding (LPW) dissimilar metals and the results of metallographic studies of the microstructure of welds ferrite - 40 steel and molybdenum - steel 40. Increasing potential opportunities the high-energy processing is carried out by integration the laser radiation (LR) and plasma, which allows you to create the desired spatial distribution of the energy flow for technological processes (TP) of laser-plasma heat treatment (LPT) of metals. The distribution of the thermal field is determined by the density distribution of energy flow LR and plasma exposure time, and the thermal characteristics of the treated metal. The most interesting is the treatment of details with ring flow of plasma and LR axial impact