On Wake-Induced Flutter of a Circular Conductor in the Wake of Another

1980 ◽  
Vol 102 (2) ◽  
pp. 125-137 ◽  
Author(s):  
Y. T. Tsui ◽  
C. C. Tsui
Keyword(s):  
Transmission Line ◽  
Coupling Coefficient ◽  
Frequency Ratio ◽  
Horizontal Axis ◽  
The Other ◽  
Two Dimensional ◽  
Coupling Ratio ◽  
Aeroelastic Stability ◽  
Other Hand ◽  
The Stability

This paper, which is an extension of [1], treats two-dimensional aeroelastic stability of two coupled conductors. It is found that the wake-induced flutter is symmetric with respect to the horizontal axis of the wake for all cases provided that the sign of the static coupling coefficient, ε = kxy/kxx, is changed. It appears that the spacer coupling ratio, K/kxx = Ω/ωx, is the most important factor in determining stability. For practical purposes, the system is almost always stable for K/kxx = Ω/ωx = 0.8, because the frequency ratio, κ = ωy/ωx, deviates less than ten percent from unity for a typical transmission line. On the other hand, within our range of interest, damping has little or no effect on the stability of coupled conductors. When the windward conductor is fixed, i.e., K = 0, then damping does influence the stability of the leeward conductor.

Polymorphs of phenazine hexacyanoferrate(II) hydrate: supramolecular isomerism in a 2D hydrogen-bonded network

2021 ◽  
Vol 77 (2) ◽  
pp. 211-218
Author(s):  
Ivica Cvrtila ◽  
Vladimir Stilinović
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
The Other ◽  
Two Dimensional ◽  
Structural Motifs ◽  
Supramolecular Isomerism ◽  
Other Hand ◽  
Π Stacking ◽  
Hydrogen Bonded

The crystal structures of two polymorphs of a phenazine hexacyanoferrate(II) salt/cocrystal, with the formula (Hphen)3[H2Fe(CN)6][H3Fe(CN)6]·2(phen)·2H2O, are reported. The polymorphs are comprised of (Hphen)2[H2Fe(CN)6] trimers and (Hphen)[(phen)2(H2O)2][H3Fe(CN)6] hexamers connected into two-dimensional (2D) hydrogen-bonded networks through strong hydrogen bonds between the [H2Fe(CN)6]2− and [H3Fe(CN)6]− anions. The layers are further connected by hydrogen bonds, as well as through π–π stacking of phenazine moieties. Aside from the identical 2D hydrogen-bonded networks, the two polymorphs share phenazine stacks comprising both protonated and neutral phenazine molecules. On the other hand, the polymorphs differ in the conformation, placement and orientation of the hydrogen-bonded trimers and hexamers within the hydrogen-bonded networks, which leads to different packing of the hydrogen-bonded layers, as well as to different hydrogen bonding between the layers. Thus, aside from an exceptional number of symmetry-independent units (nine in total), these two polymorphs show how robust structural motifs, such as charge-assisted hydrogen bonding or π-stacking, allow for different arrangements of the supramolecular units, resulting in polymorphism.

Linear Stability of a Plasma Diode

1969 ◽  
Vol 24 (8) ◽  
pp. 1235-1243 ◽  
Author(s):  
M Dobrowolny ◽  
F Engelmann ◽  
A Sestero
Keyword(s):  
Boundary Conditions ◽  
Linear Stability ◽  
Plane Waves ◽  
The Other ◽  
Other Hand ◽  
Free Particles ◽  
Plasma Diode ◽  
The Stability

AbstractThe stability of a plasma diode with respect to longitudinal oscillations is investigated. If there are free particles emitted by the electrodes, the perturbations do not have the same dynamics as they would in an infinite plasma, contrary to the case where only particles trapped in the diode are present. This can be interpreted as due to a coupling of plane waves of different wave lengths, introduced by the boundary conditions at the electrodes. The occurrence of resonant-particle effects, on the other hand, is subjected to precisely the same conditions as in an infinite plasma.

Isoprene and Rubber. XVIII. Viscosity Studies on Balata

1930 ◽  
Vol 3 (3) ◽  
pp. 516-518 ◽  
Author(s):  
H. Staudinger ◽  
E. O. Leupold
Keyword(s):  
Colloidal Particles ◽  
Colloidal Particle ◽  
Colloidal Solution ◽  
Elementary Particles ◽  
The Other ◽  
Colloidal Solutions ◽  
Specific Viscosity ◽  
Micellar Structure ◽  
Other Hand ◽  
The Stability

Abstract Varied views prevail as to the structure of the colloidal particles present in a rubber solution. According to Harries, Pummerer, and many others, these colloidal particles are formed through the association or aggregation of smaller molecules. According to Meyer and Mark they have a micellar structure, the micelles forming through the apposition of main valence chains. On the other hand, it was assumed by one of the present authors that the elementary particles in a colloidal solution of rubber are identical with the rubber molecules, these large, especially labile molecules being called macromolecules. Thus the existence of much larger molecules than any hitherto known was postulated. This view was confirmed by the conversion of rubber to hydro-rubber capable of forming colloidal solutions, and also by the pyrogenic decomposition of rubber. In order to decide definitely between the two conceptions, the stability of the colloidal particle in a rubber solution was studied by means of viscosity measurements at various temperatures as was done in the case of the polystyrols. If these colloidal particles form aggregates or if they have a micellar structure, they should decrease in size with increase in temperature, and this change should be evidenced by a diminution of the specific viscosity of the colloidal solution. On the other hand, if such a solution is composed of molecules, the specific viscosity at various temperatures is the same, provided that the molecules are not decomposed at higher temperatures. This line of research led to an explanation of the constitution of the colloidal particles in a polystyrol solution and was now applied to balata, since the latter is especially easily purified.

scholarly journals STUDIES ON OXIDATION AND REDUCTION BY PNEUMOCOCCUS

1924 ◽  
Vol 39 (5) ◽  
pp. 745-755 ◽  
Author(s):  
Oswald T. Avery ◽  
James M. Neill
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Oxygen ◽  
Hemolytic Activity ◽  
Active Agent ◽  
Organic Peroxide ◽  
Cell Extract ◽  
The Other ◽  
Cell Extracts ◽  
Other Hand ◽  
The Stability

In the present work on oxidation and reduction by sterile extracts of pneumococcus, the preparations employed contain among other constituents, a hemolytic substance the properties of which have been described by Cole (1, 2) in his studies on pneumococcus hemotoxin. Pneumococcus extracts prepared by the methods described are actively hemolytic, 0.005 cc. of extract causing complete lysis of 2.5 cc. of a 1 per cent suspension of red cells from rabbit blood. This hemolytic property of pneumococcus extracts is destroyed by 10 minutes exposure to 55°C. When pneumotoxin-containing extracts are protected from the action of molecular oxygen, their hemolytic activity remains unimpaired for considerable periods of time. In the presence of air, on the other hand, the stability of the hemolytic substance depends upon whether the particular type of extract contains a "complete" or "incomplete" oxidation-reduction system. Sterile broth extracts of unwashed pneumococci are reactive with molecular oxygen, and as a result of this union peroxide is formed whenever these extracts are exposed to air. The hemolytic activity of "complete" extracts of this type is rapidly decreased and finally destroyed in the presence of molecular oxygen. On the other hand, the "incomplete" type of extract prepared by saline extraction of washed pneumococci may be exposed to air with little or no loss of hemolytic power. This "incomplete" washed cell extract, unless reactivated, does not undergo autoxidation in the presence of air; under these circumstances peroxide is not formed and the hemolytic activity of this type of extract is not impaired by exposure to air. The stability of the hemolytic agent in the "incomplete" type of extract is evidence that this substance is itself not reactive with or affected by molecular oxygen, even in the presence of the cell enzymes. The destruction of the same hemolytic substance in extracts capable of undergoing autoxidation may be ascribed to the action of some peroxide formed by the union of molecular oxygen with easily oxidized or autoxidizable substances of the extract. It is now known that a peroxide, having the reactions of hydrogen peroxide, accumulates in sterile pneumococcus extracts during oxidation. It has been shown in the present study that the addition of preformed hydrogen peroxide destroys the hemolytic activity of pneumococcus extracts, although higher concentrations were required than were detected in oxidized extracts themselves. These facts and the known action of superoxides in analogous types of reaction make it seem not unlikely that the active agent in the destruction of pneumotoxin in oxidized cell extracts may be a peroxide; either hydrogen peroxide or some higher organic peroxide formed during autoxidation of the extract.

CONTEXT-SENSITIVITY OF TWO-DIMENSIONAL REGULAR ARRAY GRAMMARS

1989 ◽  
Vol 03 (03n04) ◽  
pp. 295-319 ◽  
Author(s):  
YASUNORI YAMAMOTO ◽  
KENICHI MORITA ◽  
KAZUHIRO SUGATA
Keyword(s):  
Context Sensitivity ◽  
The Other ◽  
Two Dimensional ◽  
Regular Array ◽  
Nonterminal Symbol ◽  
Left Hand ◽  
Other Hand ◽  
Context Free ◽  
Rewriting Rules

Regular array grammars (RAGs) are the lowest subclass in the Chomsky-like hierarchy of isometric array grammars. The left-hand side of each rewriting rule of RAGs has one nonterminal symbol and at most one "#" (a blank symbol). Therefore, the rewriting rules cannot sense contexts of non-# symbols. However, they can sense # as a kind of context. In this paper, we investigate this #-sensing ability. and study the language generating power of RAGs. Making good use of this ability, We show a method for RAGs to sense the contexts of local shapes of a host array in a derivation. Using this method, we give RAGs which generate the sets of all solid upright rectangles and all solid squares. On the other hand. it is proved that there is no context-free array grammar (and thus no RAG) which generates the set of all hollow upright rectangles.

Instability of Shielded Surface Temperature Vortices

2011 ◽  
Vol 68 (5) ◽  
pp. 964-971 ◽  
Author(s):  
Benjamin J. Harvey ◽  
Maarten H. P. Ambaum ◽  
Xavier J. Carton
Keyword(s):  
Surface Temperature ◽  
Smooth Surface ◽  
Numerical Study ◽  
Normal Modes ◽  
Euler System ◽  
The Other ◽  
Two Dimensional ◽  
Dynamics Model ◽  
Contour Dynamics ◽  
The Stability

Abstract The stability characteristics of the surface quasigeostrophic shielded Rankine vortex are found using a linearized contour dynamics model. Both the normal modes and nonmodal evolution of the system are analyzed and the results are compared with two previous studies. One is a numerical study of the instability of smooth surface quasigeostrophic vortices with which qualitative similarities are found and the other is a corresponding study for the two-dimensional Euler system with which several notable differences are highlighted.

scholarly journals Investigation of the Relationship Between the Two-Dimensional Self-Esteem Perceptions and Leadership Orientations of the Faculty of Sports Sciences Students

2021 ◽  
Vol 4 (4) ◽  
Author(s):  
Ismail Karatas ◽  
◽  
Hayri Akyuz
Keyword(s):  
Charismatic Leadership ◽  
Self Esteem ◽  
The Self ◽  
The Other ◽  
Two Dimensional ◽  
Leadership Orientations ◽  
Other Hand ◽  
Questionnaire Form ◽  
Sports Sciences ◽  
The Relationship

This research was carried out to investigate of the relationship between the two-dimensional self-esteem perceptions and leadership orientations of the students of the faculty of sports sciences. In this context, the relational survey model, which is consistent with the main purpose of the study, was used in this quantitative study. A total of 323 students, 125 females and 198 males at the Faculty of Sports Sciences of Bartın University constitute the sample of the research. Convenience sampling method, one of the non-probabilistic sampling approaches, was used in the selection of the research group. Questionnaire form was used as data collection tool and this form consisted of three parts. The first part includes the “Personal Information Form,” the second part includes the “Two-Dimensional Self-Esteem: Self-Liking/Self-Competence Scale” and the third part includes the “Multidimensional Leadership Orientations Scale.” The descriptive statistics of the raw data obtained through the questionnaire form were first calculated by considering the data type. Then, the reliability of the scales related to the obtained data were investigated, and the difference and correlation tests were used in the statistical evaluation. In this direction, it has been determined that there are significant correlations within the scope of age and family income level variables. However, there was no significant relationship within the scope of personal income level variable. On the other hand, it was found that there are significant differences in the scope of department and actively doing sports variables. However, it was observed that there were no significant differences in the scope of gender, grade, and place of residence variables. On the other hand, it was determined that there were positive and moderately significant correlations between the participants’ scores of self-liking and political leadership, human resources leadership, charismatic leadership and structural leadership. In addition, it was found that there were positive and moderately significant correlations between the self-competence scores of the participants and the scores of political leadership, charismatic leadership and structural leadership. On the other hand, it was understood that there was a statistically significant positive and low-level correlation between the participants' self-competence scores and their human resources leadership scores. As a result, it can be said that as the self-esteem of the participants increases, their leadership orientation also increases. In this context, it can be said that increasing the self-esteem of the participants is an important concept in the context of leadership orientations.

scholarly journals Stability and Volumetric Properties of Colored Asphalt Mixtures Containing Iron Oxide

2021 ◽  
Vol 24 (2) ◽  
pp. 130-136
Author(s):  
Samer Ali Naji ◽  
Alaa H. Abed
Keyword(s):  
Iron Oxide ◽  
The Other ◽  
Volumetric Properties ◽  
Oxide Content ◽  
Test Results ◽  
Other Hand ◽  
Marshall Test ◽  
The Stability ◽  
Limestone Dust ◽  
Marshall Stability

The objective of this paper is find the effect of using iron oxide as a filler on the Marshall stability, flow and the volumetric properties of HMA and compared the results with conventional HMA using limestone dust. Three blends were used: coarse, mid and fine with neat bitumen (AC 40-50). One aggregate type (crushed) with two types of fillers: limestone and iron oxide III (α- ) with three different filler content 6%, 8% and 10%. The Marshall mix design was conducted on the three blends and the optimum binder content is computed for each blend. The Marshall stability test results and the volumetric properties analysis showed that increasing the iron oxide content from 6% to 10%  increases the stability about 28%, 17% , 16% for the coarse , mid and fine mixtures respectively. This increment in stability of mixtures using iron oxide related to the increment in specific gravity of the mix (Gmb) by (1.3% to 1.5% about 30 to 50 kg/m3). On the other hand, the flow of mixtures is decreased about (5%) for mixes using iron oxide than the ones that used limestone as filler. The fine blend with 10% iron oxide exhibit the highest stability of 13.3 kN. While the coarse blend stability was 10 kN for the same filler type and content. Generally, the Marshall Test results of HMA using iron oxide as filler showed better resistance to plastic deformation, also produce denser HMA with higher stiffness. On the other hand, the volumetric properties analysis showed lesser values as compared with conventional mixture where the void in mineral aggregates and void filled with asphalt has decreased but within the acceptable limits.

scholarly journals Beggars, scammers, discriminated against by the whole of Europe: Romania’s Roma in Finnish tabloids, 2008-2011

2012 ◽  
Vol 4 (2) ◽  
pp. 87-109 ◽  
Author(s):  
Kari Alenius
Keyword(s):  
The Other ◽  
Significant Part ◽  
Radical Right ◽  
Recent Case ◽  
Short Term ◽  
Host Countries ◽  
Other Hand ◽  
The Stability ◽  
Critical Perspectives

The unrestricted movement of EU citizens from one country to another has been one of the fundamental principles of the Union. On the other hand, this issue has also attracted criticism, particularly from the radical right and so-called populist parties, or the supporters of these movements. Part of the population of Europe regards immigration and the unrestricted movement of people as a threat to the stability and prosperity of their own society. Through these critical perspectives, permanent immigration is viewed as a larger problem, as its effects on the host countries are more permanent than in the case of temporary residence. Through the same perspectives, the short-term but uncontrolled stay of foreigners is often linked to crime. This study concentrates on what kind of image a significant part of the Finnish media has given of a recent case of the foreigners that have attracted large attention in the country.

The Relationship between Legality and Legitimacy: A Double-Edged Sword

2019 ◽  
pp. 302-310
Author(s):  
Dana Burchardt
Keyword(s):  
The Other ◽  
Two Dimensional ◽  
Legal Norms ◽  
Other Hand ◽  
Norm Theory ◽  
The One ◽  
The Relationship

This comment on Thilo Marauhn’s chapter addresses the relationship between legality and legitimacy from a norm-related perspective. It inquires into the reasons for the two-dimensional relationship between legality and legitimacy through the lens of norm theory. It considers legal norms on the one hand and legitimacy norms on the other hand, interrogating how these different kinds of norms can coexist, interrelate, and influence each other and what functions they can fulfil in the international sphere. By doing so, it highlights to what extent legal norms and legitimacy norms compete and complement each other—where the double-edged sword in the relationship between legality and legitimacy can be used for undercutting or rather for defending each other.

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