scholarly journals Internal friction in certain tidal currents

1929 ◽  
Vol 124 (793) ◽  
pp. 150-163 ◽  
Keyword(s):  
Internal Friction ◽  
Turbulent Motion ◽  
Viscous Forces ◽  
Frictional Forces ◽  
Kinematic Coefficient ◽  
The Subject ◽  
North Polar ◽  
Coefficient Of Viscosity ◽  
Hydrodynamical Theory

1. In the application of hydrodynamical theory to the motion of the water in the sea or ocean it has long been desirable to obtain some measure of the internal friction. Most writers on the subject have considered this to be equivalent to the determination of a "virtual kinematic coefficient of viscosity" ( k ), taken to represent the combined effect of molecular viscosity and eddy viscosity, and which was supposed to play a part in turbulent motion analogous to that of ordinary viscosity in non-turbulent motion, except that k might vary from place to place. The validity of this supposition has, however, recently been questioned. The importance of a knowledge of the internal friction was realised in 1902, when Nansen published the results of the Norwegian North Polar Expedition of 1893-96. Subsequently methods for the determination of k were proposed, the majority of which, however, involve the assumption that at a particular place k may be considered to be independent of the depth. The only tidal work on the subject is due to J. Proudman and J. H. Powell. At the present time, however, no laws are known for the accurate prescription of the internal frictional forces, they are certainly not the simply viscous forces of non-turbulent motion.

scholarly journals XXII. Determination of the North Polar distances and proper motion of thirty fixed stars

1815 ◽  
Vol 105 ◽  
pp. 384-388
Keyword(s):  
Proper Motion ◽  
Proper Motions ◽  
The North ◽  
The Subject ◽  
North Polar

When a standard catalogue of some of the principal fixed stars was laid before the Society in the year 1813, I ventured to state as my opinion, that the error of this catalogue depending on the mechanical construction of the instrument, did not probably exceed a quarter of a second. This opinion has been confirmed by the observations of another year; the results of which I have now the honour of transmitting to the Society, as it appears that in those stars which I have continued to observe, I have not had occasion to alter the position of any one, above one-tenth of a second. For this reason I should hardly have thought it necessary to make any farther communication on the subject, had I not wished for an opportunity of adding some valuable deductions respecting the proper motions of these stars.

scholarly journals XIX. The coefficient of viscosity of air

1886 ◽  
Vol 177 ◽  
pp. 767-799 ◽  
Keyword(s):  
Internal Friction ◽  
Tangential Force ◽  
Absolute Temperature ◽  
Spare Time ◽  
The Coefficient Of Friction ◽  
The Many ◽  
Coefficient Of Viscosity ◽  
Lower Plane ◽  
Different Parts

Origin and Purpose of the Investigation . Three years ago I entered on a series of researches relating to the internal friction of metals, little calculating, when I did so, that the task which I had set myself would occupy almost the whole of my spare time from that date to this. So, however, it has been, and one of the many causes of delay has been the necessity of making a re-determination of the coefficient of viscosity of air; for the resistance of the air played far too important a part in my investigations to permit of its being either neglected or even roughly estimated. The coefficient of viscosity of air may, according to Maxwell, be best defined by considering a stratum of air between two parallel horizontal planes of indefinite extent, at a distance r from one another. Suppose the upper plane to be set in motion in a horizontal direction with a velocity of v centimetres per second, and to continue in motion till the air in the different parts of the stratum has taken up its final velocity, then the velocity of the air will increase uniformly as we pass from the lower plane to the upper. If the air in contact with the planes has the same velocity as the planes themselves, then the velocity will increase v/r centimetres per second for every centimetre we ascend. The friction between any two contiguous strata of air will then be equal to that between either surface and the air in contact with it. Suppose that this friction is equal to a tangential force f on every square centimetre, then f = μ v/r , where μ , is the coefficient of friction. If L, M, T represent the units of length, mass, and time, the dimensions of μ are L -1 MT -1 . Several investigators have attempted to determine the coefficient of viscosity of air, and the following table shows how very widely the results obtained differ among each other :— Further, Maxwell finds the coefficient of viscosity of air to be independent of the pressure and to vary directly as the absolute temperature. The above author gives the following formula for finding fit the coefficient of viscosity, at any temperature θ ° C.:— μ = .0001878(1 + .00365 θ ).

Experimental determination of the second viscosity

1954 ◽  
Vol 226 (1164) ◽  
pp. 56-57 ◽  
Keyword(s):  
Experimental Determination ◽  
Experimental Verification ◽  
Direct Method ◽  
Point Of View ◽  
Excess Adsorption ◽  
The Subject ◽  
Coefficient Of Viscosity ◽  
Theoretical Considerations ◽  
Excess Absorption

Previous speakers have mentioned that the subject of the second coefficient of viscosity was first clearly and fully dealt with by Tisza in 1942. He put forward the point of view, from theoretical considerations, that the excess absorption of highfrequency sound energy in different media could be accounted for by considering the factor of the second viscosity. His theoretical deductions, however, were not in a form which could be checked experimentally. In 1947 Gurevich again pointed out this fact and showed that excess adsorption of sound in water could be satisfactorily explained but again without experimental verification. Any direct method for the experimental determination of this coefficient is still not known.

Light Side of Design: Professional Vector

2020 ◽  
pp. 23-33
Author(s):  
Elena A. Zaeva-Burdonskaya ◽  
Yuri V. Nazarov
Keyword(s):  
Professional Practice ◽  
Wide Spectrum ◽  
Scientific Basis ◽  
Design Culture ◽  
Interdisciplinary Nature ◽  
Educational Programmes ◽  
Design Activities ◽  
The Subject ◽  
Light Side

This article addresses one of the most actively developing types of design activities – light design. The article comprises quotes of the leading Russian and foreign light design specialists published over the previous five years, as well as the authors’ own conclusions. The thoughts quoted in the article are sometimes opposite to each other and reflect the wide spectrum of professional practice. They reflect the initial opinions of analysts and experts which are often diverging. All of the specialists point at the interdisciplinary nature of the new profession, which imposes additional load on a designer overloaded enough already by the scope and speed of the problems being solved nowadays. The discussion of the new profession of light designer initiated on the pages of professional publications is especially important in view of the development of professional standards and standards of design and architectural education, as well as creation of new educational programmes based on various approaches to the subject in technical and humanitarian institutions. The goal of this article is to introduce light design into the field of fully legitimate sections of design culture, to define the authentic scientific basis of the new creative profession, to initiate a foundation for self-determination of the new synthetic area, which materially affects the state of the profession as a whole and the life standards of a wide variety of consumers. In order to reach the set goal, a comparative and analytical method of study was selected, which allows studying the problem to a large extent and from all angles and finding the ways of overcoming the challenges emerging in the area of the new activity.

Assessment of sensitivity of the efficiency of regional tax spending towards investment attractiveness of the types of economic activity carried out by the residents of advanced development territory

2020 ◽  
pp. 98-110
Author(s):  
Evgeniya Mikhailovna Popova ◽  
Guzel Mukhtarovna Guseinova ◽  
Sergei Borisovich Milov
Keyword(s):  
Economic Activity ◽  
Socioeconomic Development ◽  
Federal District ◽  
Tax Incentives ◽  
Capital Investments ◽  
The Subject ◽  
Investment Process ◽  
The Impact ◽  
Advanced Development

The deficit of subnational budgets and deceleration capital investments in multiple Russian regions increase the relevance of research aimed at improvement of tax incentivizing practice of the regional investment process. The studies focused on determination of the impact of socioeconomic and institutional factors upon the efficiency of investment tax expenses obtained wide circulation within the foreign scientific literature. The subject of this article is the assessment of sensitivity of the efficiency of regional tax expanses towards investment attractiveness of the types of economic activity carried out by the residents of territories of advanced socioeconomic development, created in the subjects of Far Easter Federal District. The scientific novelty and practical values of this research consists in substantiation of the reasonableness of assessment of investment attractiveness of the types of economic activity that are stimulated by tax incentives. Methodology for assessing investment attractiveness is proposed and tested. The conclusion is made that in case of low investment attractiveness of the type of economic activity, which was planned to support by tax incentives, it is required to conduct and additional analysis to avoid unjustified tax expanses.

Application of hydrogenated butadiene-nitrile rubbers for products operated at high temperatures and in aggressive environments

2019 ◽  
pp. 129-136 ◽  
Author(s):  
E. A. Khorova ◽  
A. V. Myshlyavtsev
Keyword(s):  
Relative Elongation ◽  
Temperature Limit ◽  
Degree Of Unsaturation ◽  
Product Service ◽  
Nitrile Rubbers ◽  
The Subject ◽  
Maximum Content ◽  
Aging In Air ◽  
Hydrocarbon Media

The subject of the study were rubber mixtures based on hydrogenated butadiene-nitrile rubbers (HNBR) Therban, Zetpol, NBR-B with an acrylonitrile (AN) content of 34% to 49% and unsaturation of 0.9% to 22% with sulfuric, peroxide and sulfuric-peroxide cure systems. The purpose of the study was to determine the effect of the AN content and the degree of unsaturation of HNBR on the properties of rubbers in products designed for operation under the influence of fuels and oils at increased temperatures.The results of the determination of the mass swelling of rubbers in hydrocarbon media and the relative elongation in the process of thermal aging in air and in oil at increased temperatures are presented. The conclusion was made on the use of HNBR mixture with maximum content of AN (49%), with low (6%) and extremely low (0.9%) ODS content and sulfuric peroxide cure system to extend the product service temperature limit to 150°C.

Introduction

2018 ◽  
Author(s):  
Chakravarthi Ram-Prasad
Keyword(s):  
Philosophical Tradition ◽  
Phenomenological Tradition ◽  
The Third ◽  
Western Philosophical Tradition ◽  
The Subject ◽  
To Come

The Introduction outlines the various chapters. It then situates the question of ‘body’ in the modern Western philosophical tradition following Descartes, and argues that this leaves subsequent responses to come under one of three options: metaphysical dualism of body and subject; any anti-dualist reductionism; or the overcoming of the divide. Describing the Phenomenology of Merleau-Ponty as a potent example of the third strategy, the Introduction then suggests his philosophy will function as foil to the ecological phenomenology developed and presented in the book. Moreover, one approach within the Western Phenomenological tradition, of treating phenomenology as a methodology for the clarification of experience (rather than the means to the determination of an ontology of the subject) is compared to the approach in this book. Since classical India, while understanding dualism, did not confront the challenge of Descartes (for better or for worse), its treatment of body follows a different trajectory.

scholarly journals Research of the Disparities in the Process of Revitalization of Brownfields in Small Towns and Cities

2021 ◽  
Vol 13 (3) ◽  
pp. 1232
Author(s):  
Natalie Szeligova ◽  
Marek Teichmann ◽  
Frantisek Kuda
Keyword(s):  
Small Towns ◽  
The Czech Republic ◽  
Essential Step ◽  
Community Strength ◽  
Population Turnover ◽  
Subsequent Application ◽  
Level Of Knowledge ◽  
The Subject ◽  
Relevant Factors

The subject of the work is the research on relevant factors influencing participation in the success of brownfield revitalization, especially in the territory of small municipalities. Research has so far dealt with the issue of determining disparities in the municipalities of the Czech Republic, not excluding small municipalities, but their subsequent application has usually been presented in larger cities. The focus on smaller municipalities or cities was usually addressed only in general. The introduction provides an overview of theoretical knowledge in the field of brownfield revitalization. Defining the level of knowledge of the monitored issues is an essential step for the purposes of more effective determination of disparities. Disparities will be determined on the basis of information on localities that have been successfully revitalized. The identified disparities are then monitored in the territory of small municipalities. For the purposes of processing, it was determined that a small municipality or city is an area with a maximum of 5000 inhabitants. Using appropriately selected statistical methods, an overview of disparities and their weights is determined, which significantly affect the success of revitalization. In small municipalities, the issue of brownfields is not emphasized but, in terms of maintaining community strength and reducing population turnover, the reuse of brownfields is a crucial theme.

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