204 research outputs found

    Composite Ceramics Based on Garnet-type Oxide Y2.5Nd0.5Al5O12 and Silicon Carbide. Preparation. Properties

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    We have obtained powders of garnet-type complex oxide Y2.5Nd0.5Al5O12 – x vol.% SiC (x = 0, 10, 20) using wet chemistry techniques. The ceramics based on the studying compounds were sintered using Spark Plasma Sintering (SPS) (

    Air ions induced aerosol sensing by eye-safe LIDAR

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    Low concentrations aerosols quantification is rather challenging for LIDAR instruments due to eye-safety restrictions so high energy pulses cannot be utilized to improve the sensitivity. Highly sensitive but eye-save LIDAR has been developed for the quantification of the water droplet aerosol which was induced by air ions. Few days sensing of aerosols in closed tunnel revealed a strong correlation between air optical transparency (LIDAR measurements) and concentrations of positive/negative ions (ion counter Sapphir 3-M). The correlation coefficient was observed to be almost unity for the air transparency signal and air ions unipolarity coefficient. High sensitivity of the water droplet aerosol quantification makes the developed eye-safe LIDAR a perspective instrument for space resolved measurements of the air ions distribution. Space and time resolved measurements of air ions exhalation can be a new instrument for tectonic activity study including new earthquake forecasting indicators search

    Diagnosis and treatment of muscle pain according to Tipaldos (literature review)

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    This review contents the information on the theory of the structure and mechanisms of damage to the body fascial system, proposed by American osteopath S. Tipaldos and named by him the Fascial Distortion Model (FDM), as well as on the original method of diagnosis and treatment of muscle pain syndromes associated with fascial damage (distortion). The author describes classifications of connective tissue and fascial structures, created by S.  Tipaldos, which are based on anatomical and functional features that determine the role of each type of fascia in compensating for various types of external influences. The conditions, mechanisms of formation and characteristics of six types of fascial lesions identified by S. Tipaldos are considered in detail: triggerband, herniated triggerpoint, continuum distortion, folding distortion, cylinder distortion, tectonic fixation. All elements of the fascial distortions diagnosis are discussed in detail, including the specification of complaints (characteristics of pain syndrome), anamnesis (history of the pain onset and its development) and an objective examination (the actual diagnostic techniques). At the same time, the special role of the patient’s description of his own painful sensations with the help of specific gestures and movements, called «body language», is emphasized. The principles and some methods of therapeutic effects used in FDM-therapy, indications and contraindications for the use of the considered manual techniques, possible side reactions that may occur during manipulation or after a session of FDMtherapy are presented. Particular attention is paid to  the evidence base of FDM therapy effectiveness in comparison with traditional methods of myofascial pain syndromes manual treatment: the results of controlled studies by foreign authors, confirming the new technique effectiveness in the treatment of certain muscle algic phenomena types, are considered

    Finite-sample and asymptotic sign-based tests for parameters of non-linear quantile regression with Markov noise

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    One of the most noticeable features of sign-based statistical procedures is an opportunity to build an exact test for simple hypothesis testing of parameters in a regression model. In this article, we expanded a sing-based approach to the nonlinear case with dependent noise. The examined model is a multi-quantile regression, which makes it possible to test hypothesis not only of regression parameters, but of noise parameters as well

    Tungstate Based Ceramics Obtained By Spark Plasma Sintering Method – Possible Material for Consolidation of Radioactive Wastes’ Components

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    The Spark Plasma Sintering method was used to produce high-density ceramics from tungstates SrWO4 and NaNd(WO4)2 with scheelite structure. These compounds are proposed as possible matrices for the consolidation of radwaste components. Powder samples were obtained by coprecipitation method and studied by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). After sintering, the samples retained their phase identity (scheelite structure). The total duration of sintering was ∼ 13-15 min, the relative density was reached ∼ 92, 99%. Keywords: Tungstates, RW, Spark Plasma Sintering, high density, microstructur

    The technologies of using generating gas in cogeneration installations

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    The paper discusses the experimental setup of gas generation from wood waste. The obtained experimental dependence of the composition of the generator gas temperature at the exit of the gasifier.В работе рассмотрена экспериментальная установка генерации газа из древесных отходов. Получены экспериментальные зависимости состава генераторного газа от температуры на выходе из газогенератора

    Investigation of the microstructure of the fine-grained YPO4_4:Gd ceramics with xenotime structure after Xe irradiation

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    The paper reports on the preparation of xenotime-structured ceramics by the Spark Plasma Sintering (SPS) method. Phosphates Y0.95_{0.95}Gd0.05_{0.05}PO4_4 (YPO4_4:Gd) were obtained by the sol-gel method. The synthesized nanopowders are collected in large agglomerates 10-50 mkm in size. Ceramics has a fine-grained microstructure and a high relative density (98.67%). The total time of the SPS process was approximately 18 min. High-density sintered ceramics YPO4_4:Gd with a xenotime structure were irradiated with Xe+26^{+26} ions (E = 167 MeV) to fluences of 1×10121\times10^{12}-3×10133\times 10^{13} cm2^{-2}. Complete amorphization at maximum fluence was not achieved. As the fluence increases, an insignificant increase in the depth of the amorphous layer is observed. According to the results of grazing incidence XRD (GIXRD), with an increase in fluence from 1×10121\times10^{12}-3×10133\times 10^{13} cm2^{-2}, an increase in the volume fraction of the amorphous structure from 20 to 70% is observed. The intensity of XRD peak 200 YPO4_4:Gd after recovery annealing (700^\circC, 18 h) reached a value of ~80% of the initial intensity I0.Comment: 16 pages, 10 figure

    Pneumatic device of the preload and dynamic loads balancing to reduce the intensity of thermal processes in the metal cutting process

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    Improved reliability of the technological system "machine-tool-instrument-detail" is an important current task. Backlashes and insufficient stiffness of technological system lead to intensive wear of the cutting tool, increasing the heat in the cutting zone. Due to high temperature in the thin surface layers of the workpiece and tool thermal processes may occur which are similar to release and can cause the structural changes of the material. The current article presents the final design of the device which has been developed to reduce the intensity of thermal processes in metal cutting

    Preparation of NZP-type Ca0.75+0.5xZr1.5Fe0.5(PO4)3-x(SiO4)x powders and ceramic, thermal expansion behavior

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    Ca0.75+0.5xZr1.5Fe0.5(PO4)3–x(SiO4)x (x = 0–0.5) solid solutions have been synthesized by a sol–gel process and characterized by X-ray diffraction, IR spectroscopy, and differential scanning calorimetry. As expected, the synthesized phosphatosilicates crystallize in a NaZr2(PO4)3-type structure (trigonal symmetry, sp. gr. R3c). The thermal expansion of the solid solutions has been studied by high-temperature Xray diffraction in the temperature range from 25 to 800°C. Their thermal expansion parameters have been calculated and analyzed as functions of composition. Highdensity ceramics based on the Ca0.875Zr1.5Fe0.5(PO4)2.75(SiO4)0.25 phosphatosilicate have been produced by spark plasma sintering and their structure and properties have been studied in detail.This work was supported by the Russian Science Foundation, project no. 16-13-10464: Advanced ceramic like mineral materials with improved and adjustable service characteristics: design, synthesis, study.Peer reviewe

    Construction and analysis of a modular model of caspase activation in apoptosis

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    <p>Abstract</p> <p>Background</p> <p>A key physiological mechanism employed by multicellular organisms is apoptosis, or programmed cell death. Apoptosis is triggered by the activation of caspases in response to both extracellular (extrinsic) and intracellular (intrinsic) signals. The extrinsic and intrinsic pathways are characterized by the formation of the death-inducing signaling complex (DISC) and the apoptosome, respectively; both the DISC and the apoptosome are oligomers with complex formation dynamics. Additionally, the extrinsic and intrinsic pathways are coupled through the mitochondrial apoptosis-induced channel via the Bcl-2 family of proteins.</p> <p>Results</p> <p>A model of caspase activation is constructed and analyzed. The apoptosis signaling network is simplified through modularization methodologies and equilibrium abstractions for three functional modules. The mathematical model is composed of a system of ordinary differential equations which is numerically solved. Multiple linear regression analysis investigates the role of each module and reduced models are constructed to identify key contributions of the extrinsic and intrinsic pathways in triggering apoptosis for different cell lines.</p> <p>Conclusion</p> <p>Through linear regression techniques, we identified the feedbacks, dissociation of complexes, and negative regulators as the key components in apoptosis. The analysis and reduced models for our model formulation reveal that the chosen cell lines predominately exhibit strong extrinsic caspase, typical of type I cell, behavior. Furthermore, under the simplified model framework, the selected cells lines exhibit different modes by which caspase activation may occur. Finally the proposed modularized model of apoptosis may generalize behavior for additional cells and tissues, specifically identifying and predicting components responsible for the transition from type I to type II cell behavior.</p
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