Restoration of Forest Live Cover and Understory in Pinetum of Former Agricultural Lands

The article presents the study of the restoration processes of vegetation in stands of pine and spruce on lands formerly used for agricultural purposes. The standard methods used in phytocenological and pedologic studies are used. It is noted that a high content of organic matter can not be a limiting factor in the growth and development of living soil cover and does not affect its projective cover. Depending on the care of stands by applying fertilizers and using herbicides, the species composition of forest live cover varies while the dominant species are preserved. The number of woody species is considerably large in pure pine cultures in comparison with those of experimental sites, where fertilizers and herbicides were applied and understory is completely absent. It should be noted that more intensive recovery is observed in pine stands treated with herbicides. In cultures of old-age pine and spruce, the natural recovery of spruce is constrained by the vegetation of understories and the canopy of forest stand. After the formation of the closed canopy of forest stand, forest site factor and heterogeneity of the soil cover are mitigated by low light under the canopy. Thus, forest live cover becomes more uniform

Variation of Physical and Mechanical Properties of Pinus Sylvestris L. Wood in the Boreal Zone of the European Northeast

The study considers variational aspects of physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood depending on conditions and growth areas in the boreal zone of the European Northeast. Anatomical traits of xylem and its strength properties were analyzed. Based on the data received, statistical processing of the material was carried out using correlation and multivariate analysis. The impact of hazardous air emissions on variation of linear dimensions in structural elements of the annual height increment in the trunk diameter was estimated. A varying nature of the influence of environmental factors on the formation of strength properties of P. sylvestris wood in growth areas was attested. The variation value of basic wood density decreases as soil and hydrological conditions of growth improve. A significant negative correlation between basic wood density and distance to sources of hazardous air emissions in the areas of concentration of industrial enterprises was established. The results of multivariate analysis make it possible to reveal the weight of the influence of environmental factors and biometric characteristics of wood on volumetric and strength properties of pine wood. Growth in the impact zone of air emissions from large industrial enterprises in the study area does not produce a significant effect on the dynamics of wood strength properties, taking into account various growth conditions. For Scots pine growing in the European Northeast, the study determined a significant impact of the size and structure of the annual height increment of the trunk in terms of diameter, as well as the position of the wood sample in terms of trunk volume, on strength properties of pine wood

Physical Nature of the Processes in Structure Forming, Phase and Chemical Composition of pipe Permanent Joints when MMA Welding

The paper outlines peculiarities of structure formation, phase and chemical composition in regard to heat content in molten electrode metal beads when pipe steel (steel 09G2S) welding using power sources with various energy characteristics. Mathematical calculations indicate an inverter power source provides minor heat content into the bead of electrode metal when welding. Experimental research has pointed at 4-9 % increase in impact strength of joints produced using an inverter power source in comparison with samples produced applying a diode rectifier. The following factors can possibly give rise to the increasing impact strength: difference in microstructures of weld joints, up to 50% shortening ferritic plates in metal of weld joint, change in dimensions of ferritic grains in the heat-affected zone by as much as 17.5 %, and decrease in the extent of heat-affected zone by 50%

Influence of Growing Medium on the Parameters and Yield Capacity of the Mini Tuber Potato of the Charoite Variety

The creation of original seed grains of the Charoite variety, healed of pathogenic infections of various etiologies, was carried out through reproduction of the certified meristematic material of the microplants class. Mini tubers microplants were grown in 5.5 liter vessels on a “Agrobalt S” soil (control) mixed with peat and supplemented with 10% and 20% (of the volume) of the “ORVI” substrate. The use of the substrate “ORVI” mixed with peat and “Agrobalt S” soil positively influenced the growth, development and formation of tubers. The appliance of 10% of the “ORVI” substrate significantly increased the quantitative yield of mini tubers by 17% and the weight of tubers by 12.3%. The increase in the total number of mini tubers was due to the increase in tuber fraction from 10 to 30 mm. The appliance of a 20% “ORVI” substrate also led to an increase in the total number and mass of mini tubers. According to the EIA results, the mini tubers grown from microplants did not contain any latent viral infection. Tests on the seeds did not reveal symptoms of fungal diseases. Keywords: breed, potatoes, mini tubers, mass of tubers, peat fertilizer, substrat

Increasing Strength and Operational Reliability of Fixed Joints of Tubes by ММА Welding

This paper presents peculiar properties of structure formation, phase and chemical composition while welding of low-alloy steel 09MnSi2-1 depending on the dynamic characteristics of power sources of different types. Proper selection of power sources enables to decrease burning of alloy elements in metal of weld (Mn by 14% and Si by 17% of the weight ratio), to obtain more homogenous structure of deposited metal, to reduce length of heat-affected zone by 50% and to improve impact strength by 4-9%

Physical Nature of the Processes in Forming Structures, Phase and Chemical Compositions of Medium-Carbon Steel Welds

This work presents peculiarities of forming a structure, phase and chemical composition while welding medium-carbon steels (Steel 45) depending on a heat content of molten electrode metal droplets when using welding power sources having different power parameters. It was experimentally established that the power inverter provides the decreased heat input into droplets of electrode metal during the welding process. This stimulates obtaining a fine-grained structure of the deposited metal and heat affected zone, reduces the extent of the HAZ that enhances working properties of welded joints

Different Approaches to the Development of Online Learning in Higher Education

The relevance of the study is substantiated by the intensive transition of the educational process to the digital environment. In this context, methods and principles of teaching, which are necessary to meet the society needs in modern education, are changing and developing. The authors reveal the issue of the global economy transformation, focusing on digital environments (digitalization). It is highlighted that digitalization contributes to the increasing demand for personnel and the necessity to improve the education system. The analysis of the theoretical features of online education is conducted, methods of its organization are identified, and modern requirements for teaching in higher education are determined. The key concepts that are the basis for the study are clarified. Approaches to the classification of online course formats and their other essential features are generalized. The authors introduce the classification of online learning in terms of time (synchronous, asynchronous) and the classification according to the degree of the educational process integration with online technologies. Additionally, the character of participants’ interaction (web support, blended learning, and fully online learning) is generalized. A review of online courses models by the format of participants’ interaction is carried out (model of online repository courses, xMOOC, cMOOC, hMOOC, ahMOOC, SPOC). The processes of online learning implementation, including e-learning and distance learning technologies in higher education have been revealed. The experience of the development of the first online courses at M. K. Ammosov North-Eastern Federal University is described. As a part of the study, the main approaches to the development of online learning in higher education are identified. The authors of the study focus on the work of the advanced training courses for the academic staff as the opportunity for professional competencies development in the context of online education

Different Approaches to the Development of Online Learning in Higher Education

The relevance of the study is substantiated by the intensive transition of the educational process to the digital environment. In this context, methods and principles of teaching, which are necessary to meet the society needs in modern education, are changing and developing. The authors reveal the issue of the global economy transformation, focusing on digital environments (digitalization). It is highlighted that digitalization contributes to the increasing demand for personnel and the necessity to improve the education system. The analysis of the theoretical features of online education is conducted, methods of its organization are identified, and modern requirements for teaching in higher education are determined. The key concepts that are the basis for the study are clarified. Approaches to the classification of online course formats and their other essential features are generalized. The authors introduce the classification of online learning in terms of time (synchronous, asynchronous) and the classification according to the degree of the educational process integration with online technologies. Additionally, the character of participants’ interaction (web support, blended learning, and fully online learning) is generalized. A review of online courses models by the format of participants’ interaction is carried out (model of online repository courses, xMOOC, cMOOC, hMOOC, ahMOOC, SPOC). The processes of online learning implementation, including e-learning and distance learning technologies in higher education have been revealed. The experience of the development of the first online courses at M. K. Ammosov North-Eastern Federal University is described. As a part of the study, the main approaches to the development of online learning in higher education are identified. The authors of the study focus on the work of the advanced training courses for the academic staff as the opportunity for professional competencies development in the context of online education

Different Approaches to the Development of Online Learning in Higher Education

The relevance of the study is substantiated by the intensive transition of the educational process to the digital environment. In this context, methods and principles of teaching, which are necessary to meet the society needs in modern education, are changing and developing. The authors reveal the issue of the global economy transformation, focusing on digital environments (digitalization). It is highlighted that digitalization contributes to the increasing demand for personnel and the necessity to improve the education system. The analysis of the theoretical features of online education is conducted, methods of its organization are identified, and modern requirements for teaching in higher education are determined. The key concepts that are the basis for the study are clarified. Approaches to the classification of online course formats and their other essential features are generalized. The authors introduce the classification of online learning in terms of time (synchronous, asynchronous) and the classification according to the degree of the educational process integration with online technologies. Additionally, the character of participants’ interaction (web support, blended learning, and fully online learning) is generalized. A review of online courses models by the format of participants’ interaction is carried out (model of online repository courses, xMOOC, cMOOC, hMOOC, ahMOOC, SPOC). The processes of online learning implementation, including e-learning and distance learning technologies in higher education have been revealed. The experience of the development of the first online courses at M. K. Ammosov North-Eastern Federal University is described. As a part of the study, the main approaches to the development of online learning in higher education are identified. The authors of the study focus on the work of the advanced training courses for the academic staff as the opportunity for professional competencies development in the context of online education

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020