scholarly journals Correct Definition of Sound Speed and Its Consequences in the Tasks of Hydrodynamics

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Vladimir Kirtskhalia

The paper considers the applied problems of hydrodynamics and based on the new results, published by the author in recent years, shows that main assumptions used in the course of their solution, namely, incompressibility of liquids and potentiality of their movement, are not applicable to liquids in the gravitational field of the Earth.

2018 ◽  
Vol 15 (1) ◽  
pp. 12-22
Author(s):  
V. M. Artyushenko ◽  
D. Y. Vinogradov

The article reviewed and analyzed the class of geometrically stable orbits (GUO). The conditions of stability in the model of the geopotential, taking into account the zonal harmonics. The sequence of calculation of the state vector of GUO in the osculating value of the argument of the latitude with the famous Ascoli-royski longitude of the ascending node, inclination and semimajor axis. The simulation is obtained the altitude profiles of SEE regarding the all-earth ellipsoid model of the gravitational field of the Earth given 7 and 32 zonal harmonics.


2019 ◽  
Vol 952 (10) ◽  
pp. 2-9
Author(s):  
Yu.M. Neiman ◽  
L.S. Sugaipova ◽  
V.V. Popadyev

As we know the spherical functions are traditionally used in geodesy for modeling the gravitational field of the Earth. But the gravitational field is not stationary either in space or in time (but the latter is beyond the scope of this article) and can change quite strongly in various directions. By its nature, the spherical functions do not fully display the local features of the field. With this in mind it is advisable to use spatially localized basis functions. So it is convenient to divide the region under consideration into segments with a nearly stationary field. The complexity of the field in each segment can be characterized by means of an anisotropic matrix resulting from the covariance analysis of the field. If we approach the modeling in this way there can arise a problem of poor coherence of local models on segments’ borders. To solve the above mentioned problem it is proposed in this article to use new basis functions with Mahalanobis metric instead of the usual Euclidean distance. The Mahalanobis metric and the quadratic form generalizing this metric enables us to take into account the structure of the field when determining the distance between the points and to make the modeling process continuous.


Author(s):  
Katharina Diehl ◽  
Tatiana Görig ◽  
Charlotte Jansen ◽  
Maike Carola Hruby ◽  
Annette B. Pfahlberg ◽  
...  

Pharmacists and pharmaceutical technicians play an important role in counselling customers regarding sunscreen use and sun protection measures. A potentially helpful tool that can be used during counselling is the ultraviolet index (UVI), which informs individuals when and what sun protection measures are needed at a specific place and time. Our aim in this qualitative study was to explore awareness, knowledge, and use of the UVI during counselling in pharmacies. We used semi-structured interviews with pharmacists and pharmaceutical technicians (n = 20) to answer our research questions. Interviews were audiotaped, transcribed verbatim, and analyzed using qualitative content analysis. During the interviews pharmacists and pharmaceutical technicians revealed a lot of uncertainty and lack of knowledge regarding the UVI. Eight professionals were able to give a correct definition of UVI. Amongst others, the UVI was confused with sun protection factor. Overall, the UVI was hardly used during the counselling of customers. The UVI was developed to provide guidance when which type of sun protection is required to avoid detrimental effects of ultraviolet radiation. For effective implementation, both the general population and health professionals (e.g., pharmacists) have to increase their knowledge about the UVI. This would strengthen its use during professional counselling in pharmacies and may help to reduce the incidence of skin cancer over the long term.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shamima Yesmin ◽  
S.M. Zabed Ahmed

Purpose The purpose of this paper is to investigate Library and Information Science (LIS) students’ understanding of infodemic and related terminologies and their ability to categorize COVID-19-related problematic information types using examples from social media platforms. Design/methodology/approach The participants of this study were LIS students from a public-funded university located at the south coast of Bangladesh. An online survey was conducted which, in addition to demographic and study information, asked students to identify the correct definition of infodemic and related terminologies and to categorize the COVID-related problematic social media posts based on their inherent problem characteristics. The correct answer for each definition and task question was assigned a score of “1”, whereas the wrong answer was coded as “0”. The percentages of correctness score for total and each category of definition and task-specific questions were computed. The independent sample t-test and ANOVA were run to examine the differences in total and category-specific scores between student groups. Findings The findings revealed that students’ knowledge concerning the definition of infodemic and related terminologies and the categorization of COVID-19-related problematic social media posts was poor. There was no significant difference in correctness scores between student groups in terms of gender, age and study levels. Originality/value To the best of the authors’ knowledge, this is the first time an effort was made to understand LIS students’ recognition and classification of problematic information. The findings can assist LIS departments in revising and improving the existing information literacy curriculum for students.


2021 ◽  
Vol 30 (1) ◽  
pp. 103-109
Author(s):  
Natan A. Eismont ◽  
Vladislav A. Zubko ◽  
Andrey A. Belyaev ◽  
Ludmila V. Zasova ◽  
Dmitriy A. Gorinov ◽  
...  

Abstract This study discusses the usage of Venus gravity assist in order to choose and reaching any point on Venusian surface. The launch of a spacecraft to Venus during the launch windows of 2029 to 2031 is considered for this purpose. The constraints for the method are the re-entry angle and the maximum possible overload. The primary basis of the proposed strategy is to use the gravitational field of Venus to transfer the spacecraft to an orbit resonant to the Venusian one – with the aim of expanding accessible landing areas. Results of the current research show that this strategy provides an essential increase in accessible landing areas and, moreover, may provide an access to any point on the surface of Venus with a small increase in ∆V required for launch from the Earth and in the flight duration. The comparison with the landing without using gravity assist near planet is also given.


2016 ◽  
Author(s):  
Valerio De Biagi ◽  
Maria Lia Napoli ◽  
Monica Barbero ◽  
Daniele Peila

Abstract. With reference to the rockfall risk estimation and the planning of rockfall protection devices one of the most critical and most discussed problems is the correct definition of the design block taking into account its return period. In this paper, a methodology for the assessment of the design block linked with its return time is proposed and discussed, following a statistical approach. The procedure is based on the survey of the blocks already detached from the slope and accumulated at the foot of the slope and the available historical data.


Author(s):  
Zoia Zahynei-Zabolotenko ◽  
◽  
Pavlo Demiak ◽  

This article is about the problem of understanding the concept „conflict of interest” and its characteristics in the legal positions of Administrative Court of Cassation as a part of Supreme Court of Ukraine. From the article we can understand that these legal positions touch the correct definition of characteristics of private interest, potential and real conflict of interest, finding out people who are subordinated to a person who is authorized to perform state or local self-government functions, and it can causes potential or real conflict of interest. These legal positions can be used in bringing the guilty persons to administrative responsibility under the Code of Administrative Offenses.


2019 ◽  
Vol 11 (2) ◽  
Author(s):  
I. Sedikova

High growth rates of natural resources consumption in recent years, pollution of the environment contribute to the development of theories regarding the future provision of natural resources on the Earth. Thepurpose of the article is to study the concept of sustainable development and the need for its introductioninto economic activity, definition of ideas influencing the modern concept of the circular economy. The concept of stable development and circular economy is analyzed, common features and differences are defined.It has been established that the circular economy is a prerequisite and driver of the fourth industrial revolution. The basis of the circular economy are closed supply chains. They combine the usual processes of adirect supply chain with reverse logistics processes, ranging from product recovery, disassembly and reuseof individual parts.


2021 ◽  
Vol 39 (3) ◽  
pp. 118-122
Author(s):  
M. A. Magomedova ◽  

In the current legislation of the Russian Federation, there is no concept of a land dispute, which causes difficulties in determining the competence of an arbitration court in cases in which the object of the dispute is land. The article analyzes the general legal concept of a dispute and the sectoral concept of a land dispute developed by scientists. The author identified the characteristic features of a land dispute and its structural elements. The work reveals the influence of the structural elements of the land dispute on the type of production in which the dispute will be considered. In addition, the author concludes that the correct definition of the structural elements of the land dispute enables the arbitration court to determine the appropriate persons participating in the case, the subject of proof, the relevance and admissibility of evidence, and ultimately make a lawful and wellgrounded court decision.


Sign in / Sign up

Export Citation Format

Share Document