Analytical method of calculating stability of rock slopes under conditions of the two-dimensional problem and determination of the necessary anchoring force for increasing stability

1970 ◽  
Vol 4 (9) ◽  
pp. 817-823 ◽  
Author(s):  
Yu. B. Mgalobelov ◽  
L. I. Khalina
Keyword(s):  
Analytical Method ◽  
Two Dimensional ◽  
Rock Slopes ◽  
Dimensional Problem

A New Look at Sound Generation by Blade/Vortex Interaction

1985 ◽  
Vol 107 (2) ◽  
pp. 224-228 ◽  
Author(s):  
J. C. Hardin ◽  
J. P. Mason
Keyword(s):  
Low Frequency ◽  
Initial Position ◽  
Sound Pulse ◽  
Two Dimensional ◽  
Vortex Interaction ◽  
Dimensional Problem ◽  
Sound Generation ◽  
Blade Vortex Interaction ◽  
Vortex Velocity

As a preliminary attempt to understand the dynamics of blade/vortex interaction, the two-dimensional problem of a rectilinear vortex filament interacting with a Joukowski airfoil is analyzed in both the lifting and nonlifting cases. The vortex velocity components could be obtained analytically and integrated to determine the vortex trajectory. With this information, the aeroacoustic low-frequency Green’s function approach could then be employed to calculate the sound produced during the encounter. The results indicate that the vortex path deviates considerably from simple convection due to the presence of the airfoil and that a reasonably sharp sound pulse is radiated during the interaction whose fundamental frequency is critically dependent upon whether the vortex passes above or below the airfoil. Determination of this gross parameter of the interaction is shown to be highly nonlinearly dependent upon airfoil circulation, vortex circulation, and initial position.

scholarly journals On the convection of heat from small cylinders in a stream of fluid: Determination of the convection constants of small platinum wires, with applications to hot-wire anemometry

1914 ◽  
Vol 90 (622) ◽  
pp. 563-570 ◽  
Keyword(s):  
Unit Volume ◽  
Unit Length ◽  
Stream Line ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
Hot Wire ◽  
Stream Lines ◽  
Hydrodynamical Problem ◽  
Uniform Stream

Sections 1 and 2.- Until comparatively recently, the problem of solving the equations of heat conduction in the case of a solid cooled by a stream of fluid had received little attention, although the general problem was formulated by Fourier himself as long ago as 1820. In 1901 the problem was taken up by Boussinesq, and many cases were dealt with in his memoir of 1905. By means of an extremely elegant transformation Boussinesq was able to express the general equation for the two-dimensional problem in a linear form: by transforming the equation to the set of orthogonal curvilinear co-ordinates determined by the stream-lines and equipotentials of the hydrodynamical problem of the flow of a uniform stream of velocity V past the cylindrical obstacle, the equation for the temperature θ at any point of the fluid takes the form ∂ 2 θ /∂ α 2 + ∂ 2 θ /∂ β 2 = 2 n ∂ θ / ∂β , (1) where the curves α = constant represent the stream-lines and β = constant the equipotentials. The constant n is given by the relation 2 n = c V/ k = s σV/ k , where c is the specific heat of the fluid per unit volume, s that per unit mass, σ its density, and k its thermal conductivity. If the surface of the cylinder be the particular stream-line α = 0, and the critical equipotentials be the curves β =o and β = β 0 , the heat-flux per unit length of the cylinder is given by H = -∫ β 0 0 k ∂ θ /∂ α 0 dβ . (2) where the integral is taken to include the two branches of the stream-lines α = 0.

The Consideration of Internal Damping in the Two-Dimensional Problem of Wing Vibration

1937 ◽  
Vol 41 (322) ◽  
pp. 945-952
Author(s):  
R. Kassner
Keyword(s):  
Critical Velocity ◽  
Graphical Method ◽  
Rapid Determination ◽  
Two Dimensional ◽  
Internal Damping ◽  
Dimensional Problem ◽  
Wing Vibration

In conjunction with H. Fingado, the author has described a graphical method for the rapid determination of the critical velocity of a two-dimensional wing without damping (see L.F.F., Vol. 13, No. 11 (20/11/36), pp. 374-387). The present paper presents a continuation of this work taking into account internal damping of the wing.

LUMINESCENT DETERMINATION OF SUGAR IN NATURAL HONEY

2020 ◽  
Vol 0 (4) ◽  
pp. 29-32
Author(s):  
B.M. GAREEV ◽  
◽  
A.M. ABDRAKHMANOV ◽  
G.L. SHARIPOV ◽  
◽  
...  
Keyword(s):  
Quantum Dots ◽  
Laboratory Test ◽  
Aqueous Solutions ◽  
Analytical Method ◽  
Sugar Content ◽  
Carbon Quantum Dots ◽  
Photoluminescence Intensity ◽  
Sucrose Content ◽  
Natural Honey

The photoluminescence of carbon quantum dots synthesized from natural honey and mixtures of honey and sugar has been studied. An increase in the sugar content leads to a decrease in the photoluminescence intensity without changing the shape of the luminescence spectrum of these quantum dots aqueous solutions, which is associated with a decrease in the yield of their synthesis in the sugar presence. The discovered effect can be used to detect sugar in honey. When examining five different market samples of flower honey using this method, two of them showed a significant decrease in the photoluminescence intensity. A laboratory test for compliance with GOST 19792-2017 Standard requirements established an excess of the sucrose content in these samples. Luminescent determination of sugar in honey does not require complicated equipment and can be used to develop a new analytical method for determining the sugar content in counterfeit natural honey.

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