136 research outputs found
Application of fresco mapping : a case study
The Assumption Cathedral in the Island Town of Sviyazhsk (Russian Federation) represents a unique cultural heritage site. Apart from the architectural elements of the building itself, it is characterized by a vast area of the 16th century art layer.
Therefore, general monitoring of the Cathedral building's condition should be combined with a systematic fresco preservation approach.
This article is dedicated to the issue of establishing a condition monitoring technique and systematization of information on fresco paintings in the Assumption Cathedral. The issue was resolved by means of combining a traditional mapping technique with the application of modern visualization tools.
The conducted work resulted in the establishment of a fresco cartogram database broken down by patterns featuring an extended functionality allowing to trace the condition of the Cathedral’s fresco paintings over time. The materials contained in this article can be used by specialists in the field of history, fresco paining and architecture.peer-reviewe
Development of modern methods for the diagnostics of murals in architectural monuments
The paper studies monitoring of the state of murals, retrieval of data pertaining to this state and management and storing of the said data. The possibility of integration of traditional methods of mural mapping and modern methods of data visualization, including new Google Project Tango device technology for fixation of complex textures of inner 3D volumes of architectural monuments has been investigated (for instance Assumption Cathedral).
We further discuss the express-scanning of automated cartogramming for further comparison of states and methods of assessing the damage done to the mural. Results indicate that additional work is needed to improve the precision of the method.peer-reviewe
TRAINING OF PEDAGOGICAL EDUCATION MASTERS: PRACTICE-ORIENTED MODEL
Purpose: The article deals with the problems of training, attraction, and retention of teachers of the required qualification in educational institutions.
Methodology: This problem is analyzed at the regional level in the context of reforms in the higher education system, the transition to a two-level model in accordance with the provisions of the Bologna process.
Result: Based on the analysis of open data in the work it is stated that the shortage of teachers in the region (Samara region) is significant and has a negative impact on the educational process of educational institutions; it cannot be compensated exclusively by bachelors of pedagogical education, issued by pedagogical universities.
Applications: This research can be used for universities, teachers, and students.
Novelty/Originality: In this research, the model of training of pedagogical education masters: practice-oriented model is presented in a comprehensive and complete manner
Влияние интенсивной пластической деформации на структуру и свойства сплава Zn–1%Li–2%Mg
Through the optimization of processing parameters, including pressure, temperature, and deformation degree, a high pressure torsion (HPT) regime was identified. This regime allows for the creation of a unique microstructure in the biodegradable Zn–1%Li–2%Mg alloy, which exhibits exceptional physical and mechanical properties. Following 10 revolutions of HPT treatment (resulting in an accumulated deformation degree, γ = 571) at the temperature of 150 °C and an applied pressure of 6 GPa, the Zn–1%Li–2%Mg alloy displayed notable mechanical characteristics, including a high yield strength (~385 MPa), ultimate tensile strength (~490 MPa), and ductility (44 %) during tensile tests. To elucidate the underlying reasons for these remarkable mechanical properties, an examination of the alloy’s microstructure was conducted employing electron microscopy and X-ray phase analysis (XPA). The study revealed the formation of a distinct microstructure characterized by alternating bands of the α-phase Zn, a mixture of Zn and ~LiZn3 phases, as well as the α-phase Zn containing Mg2Zn11 particles, as a consequence of HPT treatment. Additionally, it was observed that HPT treatment induced a dynamic strain aging process, leading to the precipitation of Zn particles in the LiZn3 phase and the precipitation of Mg2Zn11 and β-LiZn4 particles in the Zn phase. These precipitated particles exhibited a nearly spherical shape. The application of the XPA method helped to confirm that the Zn phase becomes the predominant phase during HPT treatment, and microscopy data showed the formation of an ultra-fine grained (UFG) structure within this phase. A comprehensive analysis of the hardening mechanisms, based on the newly acquired microstructural insights, revealed that enhanced strength and ductility of the Zn–1%Li–2%Mg UFG alloy can be attributed primarily to the effects of dispersion, grain boundary, and heterodeformation-induced hardening, including dislocation strengthening.Путем оптимизации параметров процессинга (давление, температура, степень деформации) найден режим интенсивной пластической деформации кручения (ИПДК), позволяющий сформировать в биоразлагаемом сплаве Zn–1%Li–2%Mg необычную микроструктуру, проявляющую уникальные физико-механические свойства. Так, после 10 оборотов ИПДК (степень накопленной деформации γ = 571), реализованной при температуре 150 °C и приложенном давлении 6 ГПа, сплав Zn–1%Li–2%Mg при испытаниях на растяжение продемонстрировал высокие показатели предела текучести (~385 МПа), предела прочности (~ 490 МПа) и пластичности (44 %). Для объяснения причин уникальных механических характеристик данного материала проанализирована его микроструктура методами электронной микроскопии и рентгенофазового анализа (РФА). Показано, что в сплаве в результате ИПДК формируется особая микроструктура, состоящая из чередующихся полос α-фазы Zn, смеси фаз Zn и ~LiZn3, а также α-фазы Zn, содержащей частицы Mg2Zn11. Установлено, что при обработке ИПДК также реализуется процесс динамического старения, в результате которого в фазе ~LiZn3 выпадают частицы Zn, а в фазе Zn – Mg2Zn11 и β-LiZn4. При этом показано, что эти частицы по форме близки к сфере. Методом РФА также установлено, что при обработке ИПДК основной становится фаза Zn, в которой, по данным микроскопии, формируется ультрамелкозернистая (УМЗ) структура. Анализ механизмов упрочнения, основанный на полученных новых сведениях о микроструктуре, показал, что основными причинами повышения прочности и пластичности УМЗ-сплава Zn–1%Li–2%Mg являются воздействия дисперсионного, зернограничного и гетеродеформационного типов упрочнения, включая дислокационный тип
Structure and crystallographic texture in the Cu-Cr-Ag alloy subjected to severe plastic deformation
© 2014 Advanced Study Center Co. Ltd. In this paper the effect of severe plastic deformation (SPD) on the structure and crystallographic texture in the Cu-Cr-Ag copper alloy have been investigated. In ultrafine-grained (UFG) samples processed by high pressure torsion (HPT), equal channel angular pressing (ECAP) and ECAP-Conform (ECAP-C) the average size of grains and precipitates was determined. Experimental pole figures (PF) have been obtained and the relevant crystallographic texture was evaluated. The effect of dynamic aging in the Cu-Cr-Ag alloy leading to improvement of strength and electrical conductivity was observed
High pressure torsion induced structural transformations in Ti- and Zr-based amorphous alloys
The melt-spun (MS) Ti50Ni25Cu25 alloy and the Zr62Cu22A110Fe5Dy1 bulk metallic glass (BMG) were subjected to high pressure torsion (HPT). X-ray diffraction (XRD) measurements show a shift of the first diffraction halo to a low angle after HPT processing, which corresponds to an increase in the values of the radius of the first coordination sphere and the free volume. Direct density measurements confirmed an increase in free volume values. A special TEM procedure was used for a detailed study of the microstructure of both amorphous alloys after HPT processing. The study revealed the formation of a large density of shear bands (SBs) in both alloys. Nanocrystals are formed directly in shear bands as a result of strain-inducted nanocrystallization. Amorphous nanoclusters with a size of 20 nm are formed in an amorphous matrix surrounding the SBs in the HPT-processed MS alloy Ti50Ni25Cu25. The formation of nanoclusters was not observed in BMG Zr62Cu22A110Fe5Dy1 after HPT processing
Effect of temperature on the evolution of structure, crystallographic texture and the anisotropy of strength properties in the Ti grade 4 alloy during continuous ECAP
© 2015 Advanced Centr Co. Ltd. This paper presents the results of experimental studies on the evolution of structure, crystallographic texture and the anisotropy of strength properties in the volume of Ti Grade 4 billets subjected to continuous equal-channel angular pressing (ECAP). Continuous ECAP is performed at temperatures of 200° 400° and 450° with 1 to 8 passes, using route BC. The methods of X-ray diffraction analysis are employed to investigate the effect of processing regimes and strain degree during continuous ECAP on the structure of the material under study. As a result of computer modelling of the crystallograpic texture evolution, the regularities in the formation of preferred orientations and the anisotropy of strength properties are established, and the activity of various slip systems and twinning systems in titanium billets, depending on the number of ECAP passes, is evaluted. Estimation of the anisotropy of strength properties, based on building of yield contours, shows that an increase in the number of passes of continuous ECAP promotes the formation of a more isotropic structure. The obtained results allow to explain and predict the deformation behavior of nanostructured Ti Grade 4 with consideration of its microstructure and crystallographic texture parameters
Parasympathetic cardiac effects in sympathectomized rats
In adult sympathectomized rats the right and left vagus nerves exhibited asymmetric effects on heart rate and strength of cardiac contractions. After vagotomy, the heart rate and stroke volume remained high in sympathectomized rats, but returned to normal in intact animals. The sympathetic nervous system plays a role in postvagotomic tachycardia. Sympathectomized rats were characterized by higher reactivity of cardiac β-adrenoceptors to propranolol compared to intact animals. © Springer Science+Business Media, Inc. 2007
Molecular recognition of organic compounds by the data on polymorphic and pseudo-polymorphic transformations of tert-butylthiacalix[4]arene derivative
The receptor properties of metastable polymorphic forms of 5,11,17,23-tetra(tert-butyl)-25,26,27,28-tetrakis[N-(2-ethoxycarbonyl(methyl) carbamoylmethoxy]-2,8,14,20-tetrathiacalix[4]arene in the cone and partial cone configurations obtained by the crystallization of their solutions in an organic solvent were studied. The ability of the studied calixarenes to "remember" the history of interaction with individual vaporous organic guests and their mixtures was discovered. The observed different effects of methanol and ethanol vapors on the phase state of the studied calixarene in the cone configuration can be used for qualitative and quantitative analyses of ethanol in binary mixtures. Calixarene in the partial cone configuration can remember the earlier bound methanol. The "memory" effect appears as a specific polymorphic transition in the receptor phase after bound methanol leaving on heating the clathrate. This effect is not observed for other studied guests. © 2014 Springer Science+Business Media, Inc
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