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Two trends have become prominent in higher education worldwide. On the one hand, globalization has favored the expansion and influence of the English language. On the other hand, email has become one of the main forms of communication in academic settings, especially in teacher-student out-of-class correspondence. While these facts have increasingly attracted scholarship attention, studies in education seem to focus more on the students’ display of face(work) alone, while neglecting the teacher’s counterpart. To redress this imbalance, the present study aims to examine face(work) as displayed in students’ email requests for consideration (e.g., on late assignments submission and class attendance) and teachers’ responses. A qualitative analysis of 20 sets of teacher-student interactions reveals different strategies opted for by the students and the teacher in face(work) management. Drawing on face-constituting theory, the findings show that whilst the students are concerned with their own face alone, the teacher is concerned with how to avoid classroom conflicts in the way that attends to one’s own face, the students’ face and the classroom harmony. In this way, the management of face(work) operates in a complex and dynamic way that allows the co-construction and reaffirmation of their respective identities. For example, whilst the students’ actions overlook the relevance of the interdependence relation between them, their peers and the teacher, which is critical for the harmony of the classroom, the teacher’s actions privilege connectedness over separateness. Furthermore, the findings suggest that cultural specificities governing the backgrounds of both the teacher and the students are not always influential in the management of face in email interactions.

Geometers have proposed more than 600 analytical surfaces for implementation. The largest number of these surfaces is used in architecture and mechanical engineering. Although digital architecture and free form architecture are now increasingly influencing the design of long-span shell structures and curved buildings, the research and application of analytical surfaces continues on an increasing scale. The purpose of the research is to study the state of affairs in the application of analytical surfaces in the construction and engineering industries and to clarify the classes of surfaces that have found application in the study of physical phenomena or in solving purely mathematical problems, but not used in other areas of human activity. Another goal is to find analytical surfaces promising for application in architecture and mechanical engineering, which are still little known to architects and engineers. It has been established that, as before, designers take new analytical surfaces to implement their creative ideas from well-studied classes of surfaces of revolution, transfer and umbrella, minimal, ruled, wavy surfaces.

A class of developable surfaces contains cylindrical, conical, and tangential developable surfaces. Tangential developable surfaces are ruled surfaces of zero Gaussian curvature with cuspidal edges. They give great opportunities to architects and engineers for realization of their creative projects. Both the theoretical researches in the area of geometry of torses and strength analysis of shells and the influence of these researches on the application of torses in practice are shown. A presented research demonstrated that torses found the application in shipbuilding, aircraft construction, mechanical engineering, in architecture and building, engineering equipment and communications, in road building, in anti-erosive banks, topography, and cartography, clothing articles of light industry, in sculptural forms, and in modelling with developable surfaces. It was confirmed by the references on great number of published works on the subject, real examples from practice, and by handing in 14 illustrations of real objects.

The article introduces new paleoanthropological materials from the Mayak burial ground near Sidelkino village in the Samara region into scientific discourse. The materials were obtained as a result of excavations in 1995 and only recently was it possible to date them. As a result of AMS analysis fulfilled by the authors, human remains from two burials were dated back to the Early Mesolithic. The analysis was carried out taking into account the influence of the “reservoir effect.Despite the rather poor preservation of individuals from the two described burials, the authors carried out an osteological analysis of an adult male from the second burial. He turned out to be quite tall, with elongated legs, shortened forearms, saber-shaped tibia and relatively massive bones of the lower limbs. In burial 3, the remains of an adult woman and a child of 7–10 years old were found. Comparing the osteological indicators of the man from the second burial with materials from the same burial ground of excavations in 2002, the authors came to the conclusion that the people whose remains were found on the hill Mayak in 1995 and in 2002 probably belong to the same population. Similar morphological characteristics are proof of this.

The architects working with the shell use well-established geometry forms, which make up about 5-10 % of the number of known surfaces, in their projects. However, there is such a well-known surface of rotation, which from the 19th century to the present is very popular among mathematicians-geometers, but it is practically unknown to architects and designers, there are no examples of its use in the construction industry. This is a pseudosphere surface. For a pseudospherical surface with a pseudosphere rib radius, the Gaussian curvature at all points equals the constant negative number. The pseudosphere, or the surface of the Beltram, is generated by the rotation of the tracersis, evolvent of the chain line. The article provides an overview of known methods of calculation of pseudospherical shells and explores the strain-stress state of thin shells of revolution with close geometry parameters to identify optimal forms. As noted earlier, no examples of the use of the surface of the pseudosphere in the construction industry have been found in the scientific and technical literature. Only Kenneth Becher presented examples of pseudospheres implemented in nature: a gypsum model of the pseudosphere made by V. Martin Schilling at the end of the 19th century.

From the old ancient types of roof and dome construction, various forms of shells have been discovered which attract special attention. A shell is a structure composed of sheet material so that the curvature plays an important role in the structural behaviour, realizing its spatial form. There are different types of shells, namely thick and thin shells. G. Brankov, S.N. Krivoshapko, V.N. Ivanov, and V.A. Romanova made interesting researches of shells in the form of umbrella and umbrella-type surfaces. The term nonlinear refers to a given structure undergoing a change in stiffness in its loaded state. There are basically three different types of nonlinearities: geometric, physical and contact (boundary condition nonlinearity). For further analysis of the stress-strain state, a paraboloid with an inner radius of 4 m and an outer radius of 20 m and the number of waves equal to 6 was considered. The test shell is made of reinforced concrete. The minimum load parameter at which the shell loses stability indicates a more than three times the margin.

Structures are designed using current seismic design codes which are mostly based on Force-Based Design approach. The aim of the work is to implement the Performance-Based Seismic Design (PBSD) approach in concrete buildings. PBSD, which is a new concept in seismic design of structures, is a reliable approach capable of providing more detailed information on the performance levels of both structural and non-structural elements. Methods. In this study Performance-Based Seismic Design has been utilized on reinforced concrete irregular frame. In order to do this pushover analysis was done. Story drift ratios were chosen as deformation limits to define the performance levels for specific earthquake hazard levels. The results of this study show that Performance-Based Seismic Design gives a structure with better seismic load carrying capacity, thereby achieving the objective of performance as well as economy. It is also possible to conclude that PBSD obtained by above procedure satisfies the acceptance criteria for immediate occupancy and life safety limit states for various intensities of earthquakes.

Aims of research. A surface of revolution is generated by rotation of a plane curve z = f(x) about an axis Oz called the axis of rotation. This paper provides information on hyperboloids of revolution surfaces and their classification. Their geometric modeling, linear and materially nonlinear analysis are worked out. Methods. Hyperboloids of revolution middle surface is plotted using the software MathCAD. The linear and materially nonlinear numerical analyses of thin shells of the shape of an hyperboloid of revolution surfaces on stress-strain state is given in this paper, using the finite elements method in a computer software R-FEM, the material which we use in our model is concrete with isotopic nonlinear 2D/3D stress-strain curve for materially nonlinear analysis and linear stress-strain curve for linear analyses. Comparison is done with the result of the finite elements linear analysis of their strain-stress results. Results. That displacements in the investigated shells subject to self-weight, wind load with materially nonlinear analysis are bigger than which done by linear analysis, in the other side the displacements is similarity subjected to free vibration load case. Based on these results, conclusions are made for the whole paper.

Accidentul ischemic cerebral (AIC) sau infarctul cerebral (IC) reprezintă 80% din numărul total de accidente vasculare cerebrale (AVC), ocluzia unei/sau mai multor artere cerebrale fiind confirmată prin examene imagistice non invazive (IRM sau TC cerebrală cu sau fără injectare a substanței de contrast). Ultimele 3-4 decenii au fost revoluționare pentru tratamentul AIC, fiind puse în aplicare: aspirina, anticoagulantele orale antivitamina K (AVK), anticoagulantele orale cu acțiune directă (AOD), tromboliza intravenoasă (TI), trombectomia (T) și hemicraniotomia decompresivă. Terapia de recanalizare prin tratament fibrinolitic intravenos și trombectomie au obiectivul de ameliorare clinică a pacientului prin reperfuzia zonei de penumbră ischemică. AIC este o urgență vitală, iar un tratament administrat rapid, adecvat și eficient semnifică nu doar viața, ci și recuperarea autonomiei pacientului - „time is brain”.

Aims. Thin shells in the form of cylindroids are fourth-degree ruled shells for which few works are devoted. In this paper, their geometric modeling is worked out and their middle surface are plotted, using the software MathCAD. Their stress-strain state are instigated with two building material: reinforcement concert and qualitative steel. Methods. This linear investigation is done for fixed and hinged supports and for various thicknesses in the software SCAD. The numerical values of their maximum and minimum displacements of their middle surfaces are given. Based on these displacements, conclusions are made for the whole paper. Results. The linear analysis for reinforced concrete and metallic shells, computed using the software SCAD gives the numerical and graphical results that are presented. Conclusions. The investigations of the stress-strain state are done for shells with the shape of cylindroid with two directrices ellipses and cylindroid Frazer. For the same thickness, loading and span, the reinforced concrete shells has minimum displacements. For thickness, 20 cm the steel shells have the same maximum displacements. For the thickness 30 cm the maximum displacement is more in steel shells. It is more optimal to use reinforced concrete shells than the one in steel. A large span (till 30 m) shells can be designed with reinforced concrete.

The paper concerns the buckling analysis of thin shells of right helicoid form. The buckling analysis was performed by the means of finite element software. Shells with variable pitch number and same contour radiuses and height were compared, their straight edges fixed and the curvilinear contours free. Was used for the analysis triangular shell finite elements (No. 42). The total number of nodal unknowns was the same in each of the considered tasks and was 16 206. Numerical investigation of the stability was performed by the finite element method in the software package Lira-Sapr 2017. The number of nodes in each task was the same. The loading includes combination of gravity (dead load) and vertical equally distributed load. The buckling mode and stability factor for every case is calculated. Boundary conditions - elastic built in shells along the bottom and top generatrices. To plot the midsurface of each shell were used parametric equations in rectangular coordinates. Of particular interest is the study of natural oscillations of the shells considered. To define the frequencies and forms of free vibrations is taken into account only the own weight of the helicoidal shells.

Gorky started his literary career as a playwright at the Moscow Art Theatre. He wrote his first plays for its troupe in competition with Chekhov whose plays were performed there during the same period. Thus, two Moscow Art Theatre directors, Stanislavsky and Nemirovich-Danchenko dealts with two authors whom they valued but whose approaches differed. My paper that forms part of a study concerning Gorky’s collaboration with the Moscow Art Theatre, focuses on the way in which Stanislavsky and Nemirovich-Danchenko revised and embellished the history of their relationship with Gorky in their autobiographies both written in the Soviet period, My Life in Art (1926) and My Life in the Russian theatre (1936) respectively. In real fact, the relationship was problematic due to Gorky’s political opinions and the difficulties that the actors encountered playing his characters. Since the middle of the 1920s, Gorky became a defender of the Moscow Art Theatre and consequently, the two directors put their political and aesthetic contradictions aside and sought to reconcile themselves with Gorky who contributed to make the Art Moscow Theatre a model Soviet theatre. Besides, the writer supported Stanislavsky in founding an opera-dramatic studio in 1935 and writing and publishing “The Stanislavsky System.”

The nonlinear analysis of thin-walled shells is not a rarity, particularly the nonlinear strength one. Many works are devoted to linear and nonlinear analyses of shells of classical form: cylindrical, spherical, hemispherical, shallow, conical. The concept of shells of complex geometry appears when the coefficients of the first and second quadratic forms of their middle surfaces are functions of the curvilinear coordinates. Concerning nonlinearity, it is generally accepted that four different sources of nonlinearity exist in solid mechanics: the geometric nonlinearity, the material nonlinearity and the kinetic nonlinearity. The above theoretical aspect of the nonlinearity, applied to a sinusoidal velaroidal shell with the inner radius r0=1m, the outer radius R=20m and the number of waves n= 8, will give rise to the investigation of its nonlinear buckling resistance. The building material is a concrete. The investigation emphasizes more on the material and the geometric nonlinearities, which are more closed to the reality. Finite element model of the shell consists of 6400 elements and 3280 nodes, the total number of nodal unknown - 18991. For surface modelling was used flat shell elements with six degrees of freedom in the node. The boundary conditions cor- respond to hinged bearing on the outer and inner contours. The result of the investigation is the buckling force of the shell under self-weight and uniformly vertically distributed load on its area, the corresponding numerical values of displacements and the buckling mode

In this article, assumptions in Classical Plate Theory (CPT) are explained; followed by concepts involved in Finite Element discretization for elastic Plate bending in CPT. Computer implementation aspects and Numerical Results of CPT elements are also included for analyzing nonlinear bending of simply supported elastic plates.

The main subjects of the article are theoretical strength and buckling analyses of a sinusoidal velaroidal shell subjected to its self-weight and uniformly distributed load in geometric nonlinearity. A short history of finite element applications to shell buckling is given. The finite element method is used in its matrix formulation. The elastic stiffness matrixes in the local coordinate system of the membrane element are defined in their general form. The out-of-plane geometric stiffness matrix for the plate along the same lines is derived

В настоящей статье рассматривается устойчивость функционально-градиентных эпитро- хоидальных оболочек под давлением и тепловой среды.Свойства материала принимаются как зависящие от температуры.Конечно-элементные решения получены с помощью про- граммного комплекса ANSYS. Линейные задачи на собственные значения устойчивости решается с помощью блочного метода Ланцоша. Влияние различной геометрии и парамет- ров материала на критическую температур функционально-градиентных эпитрохоидальных оболочек под давлением и тепловой средой наглядно показано. В конце, изменение напря- жений, перемещений, вращений и деформаций изучены и представлены.

This article deals with FGM for cyclic shell structure and the finite element modeling and analysis of functionally graded (FG) shell structures under self-loading. In order to study the influences of important parameters on the responses of FG shell structures, some types of cyclic shells have been considered. The responses obtained for FG shells are based on the analysis; some important results are presented and discussed for thincyclic shells.

In the paper algorithm software of creation mini-film “Formation of revolving surfaces formation” is considered. This film is essentially a didactic material to the subjects «Computer Graphics» and «Descriptive Geometry».

Возможные виды потери устойчивости в эпитроидальных оболочках могут быть разбиты на две категории: потеря устойчивости в сжато-изогнутых оболочках и потеря устойчивости в сжатых оболочках. Эти вопросы изучаются в статье