Search

Abstract We have found low temperature a/b nanotwins having (110) twinning plane in a five-layered modulated martensite phase of Ni50Mn25+x Ga25−x (at. %) Heusler alloys and identified the particular region in phase diagram where the nanotwinning occurs. Evolution of the structure with decreasing temperature was studied by X-ray diffraction using single crystals exhibiting magnetic shape memory effect. The merging of (400) and (040) lines upon cooling for 2.6

Two bending tests around two perpendicular axes were applied to 10M Ni-Mn-Ga single crystals with five-layered modulated structure. The crystal structure and microstructure evolution were examined using synchrotron radiation and electron backscatter diffraction, respectively. The bend stress results in pseudoelasto-plastic strain due to {101) twins tapering. A close examination of the microstructure reveals an additional pattern indicating microstructural changes in the form of {110) twins. As bending proceeds the {110) twins branch undergoing a significant twin refinement. Additionally, an elastic change of lattice parameters is confirmed yielding a higher total pseudoelastic strain. Unloading restores the initial twin configuration removing a large amount of the {110) twin boundaries, however, this process is followed by incomplete recovery since the samples do not retain its original shape entirely. The paper underlines the differences in mechanism for bending around two perpendicular axes explaining the amount of strain observed under pseudoelastic deformation. Additionally, the results are discussed with respect to minimization of elastic energy due to twin refinement and branching as well as mobility of the {101) and {110) twin boundaries. Keywords: NiMnGa, Bending, Twinning, Interfacial misfit, Continuum mechanics

For the processing of coal mine methane into hydrogen-containing gas, a catalytic process of methane tri-reforming (СH4 + O2 + CO2 + H2O) was proposed and its component reactions were studied – partial oxidation (СH4 + O2, POM), dry reforming (СH4 + CO2, DRM) and steam reforming (СH4 + H2O, SRM) of methane. Promoted nickel supported on aluminum oxide was used as a catalyst. Experiments were carried out by varying temperature (600–850 ºC), contact time (0.04–0.15 s), linear feed rate (40–240 cm/min) and composition of the reaction mixture (POM – СH4 : O2 : He = 1 : (0.5–0.7) : (3.3–3.4); DRM – СH4 : CO2 : He = 1 : (0.8–1.4) : (2.6–3.2); SRM – CH4 : H2O : He = 1 : (0.8–2.0) : (2.0–3.2)). Optimal reaction conditions were determined to ensure maximum efficiency of hydrogen production by reforming methane-containing mixtures of various compositions (temperature in the range of 800–850 ºC, contact time 0.15 s, linear feed rate 160 cm/min, molar ratio of CH4 : O2 = 1 : 0.5 for POM, CH4 : CO2 = 1 : 1 for DRM and CH4 : H2O = 1 : 1.1 for SRM). The degree of catalyst carbonization during the reactions was reduced (from 3 to 1.5% for POM, from 20.7 to 2.2% for DRM, and from 15.2 to 0.4% for SRM) due to an increase in the O/C molar ratio in the initial reaction mixture. Regulation of H2/CO molar ratio was achieved over a wide range (0.9–6.5). It has been shown that the hydrogen concentration in the resulting hydrogen-containing mixture is determined by the type of process and is equal to 30±5 vol.%.

The paper aims to review the possibilities of a complex transdisciplinary approach to forming health and longevity. Determinants of productive longevity (DPL) and health culture are reviewed; definitions of health, stress, and eustress, and their roles in active and productive longevity are given. DPL making a decisive contribution to the phenomenon of active longevity are stated and analyzed from the point of view of evidence-based medicine. They are as follows: 1) environmental factors including geographical location, “Blue zones”, and mountain areas, as well as level of the environmental pollution; 2) dietary regimen to support active longevity, including vegetarianism, calorie restriction, fasting, the role of vitamins, biological antioxidants, geroprotectors, and micronutrients; 3) importance of activity and eustress phenomenon, by other words, lifestyle: physical activity, sexual relationship, Qigong and Yoga practices, cognitive activity, sense of humor, and acceptance of age in activities of daily living and survival; 4) genetic and epigenetic particularities as a condition for long-living; 5) level of health care and early diagnostics to prevent age-associated diseases; 6) the role of the state of mind and meditation as well, how it is used for forming health due to Qigong and Yoga natural systems, in religion, and medical practice; 7) motivation for active longevity that significantly increases chances to productive longevity.

This paper studies the transformation of the carbon framework of coal tar pitch in the process of thermolysis in the presence of carbon additives of different structures. It is established that as a result of the application of all investigated carbon additives, the content of volatile products released as a result of the thermolysis of the ash, including carcinogenic compounds, decreases, which contributes to the increase of the coke residue yield. The highest yield of coke residue was found when using nanostructured carbon materials as an additive, but the structure of the resulting carbon material is more disordered than in the case of individual pitch. It is shown that the use of such additives promotes the formation of graphite-like structures in the process of thermolysis of pitch and to a greater extent than amorphous carbon additives, reduces the amount of carcinogenic volatile products of coal tar pitch thermolysis.

By methods of electron microscopy, adsorption porometry, NMR, IR- EPR spectroscopy, X-ray diffractometry, thermal analysis, chromatography-mass spectrometry the composition, structure and particle morphology of β- and α2-fraction powders of medium-temperature coal ash were investigated. The morphology and structure of coke residues depending on the heating temperature were investigated. Polyaromatic hydrocarbons in the composition of volatile products of coal ash thermolysis were found to be formed mainly by the decomposition of components of β-fraction. The results obtained are of interest from the point of view of the feasibility of using the isolated fractions of coal ash as precursors for the production of functional carbon materials.

The article is devoted to topical issues of establishment and development of pedagogical and scientific traditions in the history of Kazan pediatric school. The authors determine the retrospective of the pediatrics implementation and variants of infrastructure changes (via representative archival materials, moreover, some of them are used for scientific use for the first time) during the establishment of the childhood diseases department of medical sciences department in Imperial Kazan University. The vector of the “childhood diseases” discipline teaching development in Kazan is presented and compared with such in capitals. It is determined that the course of childhood diseases was implemented at the medical faculty of Imperial Kazan University in the fall of 1823 or 1823/1824 academic year. Moreover, the aspects of Alexander Egorovich Lentovsky assuming the position of the first professor of this course were revealed, described, and analyzed. He was one of the first medical graduates of Kazan University. Furthermore, this article shows the role of Kazan University teaching staff in the process of discussions implementation for further improvement of medical and pedagogical activities.

Task switching is a behavioral phenomenon that serves as a tool for assessment of individual cognitive abilities that becomes especially essential in our multitasking milieu. Factors of task-switching include cognitive load and cognitive effort, mostly derived from task difficulty, as well as age and practice. The analysis of brain activity on the level of single neurons shows that the activations that contribute to task performance and switching differ with respect to the protocol of learning the alternated tasks. We argue that task switching is affected by the history of learning and in turn it changes the structure of individual experience. On this basis we outline perspectives of task switching studies in the fundamental field of long-term memory and applied field of education and therapy.

Background. Most healthcare-associated infections (HAI) develop due to a colonization of patients and healthcare workers by hospital strains of pathogens. The aim to study was to assess whether the dust within the health facilities can harbor microorganisms acting as a reservoir of HAIs.Materials and methods. Dust samples collected in the air ducts and ventilation grilles of health facilities underwent a detailed physicochemical analysis by means of scanning electron microscopy, dynamic light scattering, energy-dispersive X-ray spectroscopy, and high-temperature catalytic oxidation. Bacterial and viral diversity was investigated using an automated biochemical analyzer and polymerase chain reaction, respectively. Investigation of the microenvironment included detection of biofilms using a catalase indicator and quantification of viable microorganisms per 1 m3 air.Results. Dust from the hospital ventilation grilles and air ducts was contaminated with microorganisms in 71.13% of cases. Strikingly, multidrug-resistant and biofilm-forming strains have been found in 69.4% and 48.0% of samples, respectively. The total viable count before and after opening doors and windows was 276 and 462 colony-forming units/m3 respectively (p = 0.046). Biodiversity was represented by 21 genera of microorganisms which were consistently detected upon 6 months of follow-up. All samples contained a nanosized particulate matter. Chemical elements comprising dust were carbon (16.26–50.69%), oxygen (20.02–37.50%), nitrogen (1.59–25.03%), hydrogen (2.03–6.67%), sulfur (0.15–2.38%), calcium (0.19–7.49%), silicon (0.21–4.64%), chlorine (0.05–2.83%), sodium (0.07–1.86%), aluminum (0.36–1.78%), iron (0.08–1.61%), magnesium (0.11–1.40%), potassium (0.04–0.85%), and phosphorus (0.04–0.81%).Discussion. A wide range of multidrug-resistant strains of bacteria, detected in a hospital particulate matter with a diverse chemical composition, indicates the persistence of HAI-causing pathogens in the hospital environment.Conclusion. Dust from the ventilation grilles and adjacent air ducts should be considered as an additional reservoir of multidrug-resistant strains of bacteria in the healthcare settings.

Article is based on performance of the Rector of the Kazan State Medical University at the VIII Conference «Pediatrics and Pediatric Surgery in the Volga Federal District» September 20, 2011, devoted to the 70th anniversary of the famous Russian pediatricians — academician A.A. Baranov, professors V.Yu. Albitsky, A.V. Kuznetsova, S.V. Maltsev, O.I. Pikuza, who graduated Department of Pediatrics KSMA in 1964. Presents data on scientific creativity and contribution of anniversaries in pediatric science, to the protection of the health of the child population of Tatarstan and Russia.

Hydrogen production from biogas over alumina-supported Ce1−xNixO2−x catalysts was studied in a temperature range of 600–850 °C with an initial gas composition of CH4/CO2/H2O of 1/0.8/0.4. To achieve a high and stable hydrogen yield, highly dispersed Ni catalysts were prepared through the exsolution approach. A solid solution of Ce1−xNixO2−x was firstly formed on the surface of Al2O3 and then activated in H2/Ar at 800 °C. The genesis and properties of the Ce1−xNixO2−x/Al2O3 catalysts were established using X-ray fluorescence analysis, thermal analysis, N2 adsorption, ex situ and in situ X-ray diffraction, Raman spectroscopy, electron microscopy, EDX analysis, and temperature-programmed hydrogen reduction. The performance of Ce1−xNixO2−x/Al2O3 catalysts in biogas conversion was tuned by regulation of the dispersion and reducibility of the active component through variation of content (5–20 wt.%) and composition (x = 0.2, 0.5, 0.8) of Ce1−xNixO2−x as well as the mode of its loading (co-impregnation (CI), citrate sol–gel method (SG)). For the 20 wt.% Ce1−xNixO2−x/Al2O3 catalyst, the rate of the coke formation decreased by a factor of 10 as x increased from 0.2 to 0.8. The optimal catalyst composition (20 wt.% Ce0.2Ni0.8O1.8/80 wt.% Al2O3) and preparation mode (citrate sol–gel method) were determined. At 850 °C, the 20 wt.% Ce0.2Ni0.8O1.8/Al2O3-SG catalyst provides 100% hydrogen yield at full CH4 conversion and 85% CO2 utilization.