Metastable states relaxation in the active medium of metal vapor lasers

One of the main reasons for limiting the frequency-energy characteristics (FEC) of radiation from lasers based on self limited transitions of metal atoms (LSTM) is the high values of the prepulse electron concentration and metastable states population of metal atoms in the active medium. Which of these parameters determines the limitation of the frequency energy characteristics of laser radiation has been the subject of a long discussion, although it is well known that metastable states are very effectively quenched in collisions with electrons

Assessment of Economic Effectiveness of Competing IT-projects: Approaches and Mathematical Tools

Evaluation of the effectiveness of the implementation and development of information systems and information technology is one of the challenging tasks in managing it projects. However, we also know that it affect the success of the company, but they also require large investments and carry significant risks. Therefore, the decision to select the automation of business processes should be after in-depth analysis with mathematical tools. The purpose of this work is to show the possibility of expanding the mathematical apparatus of analysis of it projects that require significant investment. The article presents examples of results of expert opinion for estimation of expected cash flows, considering the risks when investing in competing projects, based on the methods of mathematical statistics. Describes the conditions of the solution of a multicriteria problem of choice of one it project of the alternatives, based on economic sense of indicators of risk. The rationale for the use of different methods when comparing projects of different durations (chain of repetition, equivalent annuity, etc.). The introduction of new information systems affects the quality indicators of the business, including improving productivity, reducing errors in performing the tasks, and thereby improving financial results. Selected mathematical methods will allow for different stages of decision-making to provide comprehensive and scientifically-based analysis of project performance and objectivity of the decisions made by the IT-manager

Domain diversity and polarization switching in amino acid β-glycine

Piezoelectric materials based on lead zirconate titanate are widely used in sensors and actuators. However, their application is limited because of high processing temperature, brittleness, lack of conformal deposition and, more importantly, intrinsic incompatibility with biological environments. Recent studies on bioorganic piezoelectrics have demonstrated their potential in these applications, essentially due to using the same building blocks as those used by nature. In this work, we used piezoresponse force microscopy (PFM) to study the domain structures and polarization reversal in the smallest amino acid glycine, which recently attracted a lot of attention due to its strong shear piezoelectric activity. In this uniaxial ferroelectric, a diverse domain structure that includes both 180° and charged domain walls was observed, as well as domain wall kinks related to peculiar growth and crystallographic structure of this material. Local polarization switching was studied by applying a bias voltage to the PFM tip, and the possibility to control the resulting domain structure was demonstrated. This study has shown that the as-grown domain structure and changes in the electric field in glycine are qualitatively similar to those found in the uniaxial inorganic ferroelectrics. © 2019 by the authors

Linear magnetoresistance in compensated graphene bilayer

We report a nonsaturating linear magnetoresistance in charge-compensated bilayer graphene in a temperature range from 1.5 to 150 K. The observed linear magnetoresistance disappears away from charge neutrality ruling out the traditional explanation of the effect in terms of the classical random resistor network model. We show that experimental results qualitatively agree with a phenomenological two-fluid model taking into account electron-hole recombination and finite-size sample geometry

Effective Power and Speed of Mining Dump Trucks in Fuel Economy Mode

Existing methods for determining the effective power, based on the calculation of the average indicator operation of the engine during the piston stroke, do not take into account the change in thermodynamic parameters and the polytropic operation of the engine, the value of which depends on the polytropic efficiency of the duty cycle. This is the reason that the calculation of the effective power leads to some error – the margin of the engine features. The identification of this stock allows us to review the entire line of dump trucks in the direction of increasing their pass- port effective capacity, which will lead to a reduction in capital purchase costs due to the choice of a previously un- derestimated and cheaper option, as well as a reduction in current operating costs due to a decrease in the specific fuel consumption rate. Taking into account the stochastic nature of the transport process and assessing the influence of all external and internal factors when calculating the rational mode of operation of a mining truck can further reduce specific fuel consumption by choosing the rational speed of its movement in loaded and empty directions

Result Analysis of the Local FCE Examination Sessions (2013-2014) at Tomsk Polytechnic University

In this article the authors cover main international English Language Examinations, their role in defining language proficiency and interpreting language qualifications and review the structure of English as a foreign language examination FCE (First Certificate in English). The applied part of the paper contains the result analysis of this examination at Tomsk Polytechnic University (local sessions 2013 and 2014) and is aimed at identifying the most complicated papers of the exam and the relationship between English proficiency and the difficulties detected (based on certificate grades). Theoretical analysis of methodological literature, mathematical research methods for data and results processing, as well as authors’ personal experience of administering local EFL examination sessions were used. The obtained results allow us to conclude that in productive skills there is no relationship between certificate grade and difficulty in Writing and Speaking papers of the test. The Listening paper was considered to be the most difficult. The following relationship is revealed: the lower English proficiency a candidate has, the more interference of the gaps in the student’s knowledge in different examination papers is observed, therefore, the greater difficulty he/she encounters when completing examination questions. This work will be useful for language teachers, graduate students, students of English who are preparing for the FCE exam. DOI: 10.5901/mjss.2015.v6n3s1p23

β-glycine piezoelectric and ferroelectric properties behavior at elevated temperatures

The research was carried out using equipment of Ural Center for Shared Use "Modern Nanotechnologies" Ural Federal University. The reported study was funded by RFBR according to the research project № 18-32-00390

Formation of Artistic and Aesthetic Culture in Children of Preschool Age

В статье представлен анализ опытно-экспериментальной работы по развитию художественно-эстетической культуры посредством слушания музыки. Проанализированы критерии оценки сформированности художественно-эстетической культуры дошкольников.The article presents an analysis of experimental work on the development of artistic and aesthetic culture through listening to music. The criteria for assessing the formation of the artistic and aesthetic culture of preschoolers are analyzed

Development of Artistic and Aesthetic Taste in Preschoolers Through Listening to Music

В статье представлен теоретический анализ теоретической литературы по проблеме развития общения художественно-эстетической культуры дошкольников посредством слушания музыки. Определена роль музыки в эстетическом развитии. Авторами изучены взгляды, подходы ученых по данной проблеме. Анализирована теоретическая основа художественно-эстетической культуры, способы и пути ее формирования.The article presents a theoretical analysis of theoretical literature on the development of communication of artistic and aesthetic culture of preschoolers through listening to music. The role of music in aesthetic development is determined. The authors studied the views, approaches of scientists on this issue. The theoretical basis of artistic and aesthetic culture, methods and ways of its formation are analyzed