Lielmezs–Herrick correlation for the temperature-dependent surface tension of hydrocarbons

2016 ◽  
Vol 30 (23) ◽  
pp. 1650154 ◽  
Author(s):  
Cuihua Zhang ◽  
Huili Yi ◽  
Jianxiang Tian

In this paper, we analyzed the ability of Lielmezs–Herrick (LH) correlation for the temperature-dependent surface tension of 28 hydrocarbons. We found that compared with other published correlations, the original LH correlation stands well only for four fluids. By using new data in REFPROP database, we refitted the two parameters of LH correlation. Two sets values are obtained. One is the updated corresponding state LH correlation, which is fluid independent. The other is the two-parameter LH correlation, which is fluid dependent. We found that the former clearly improves the accuracy of the original LH correlation and the latter is the best among all of the correlations we know.

2019 ◽  
Vol 18 (05) ◽  
pp. 445-454 ◽  
Author(s):  
John G. Sotos

AbstractThe number of people able to end Earth's technical civilization has heretofore been small. Emerging dual-use technologies, such as biotechnology, may give similar power to thousands or millions of individuals. To quantitatively investigate the ramifications of such a marked shift on the survival of both terrestrial and extraterrestrial technical civilizations, this paper presents a two-parameter model for civilizational lifespans, i.e. the quantity L in Drake's equation for the number of communicating extraterrestrial civilizations. One parameter characterizes the population lethality of a civilization's biotechnology and the other characterizes the civilization's psychosociology. L is demonstrated to be less than the inverse of the product of these two parameters. Using empiric data from PubMed to inform the biotechnology parameter, the model predicts human civilization's median survival time as decades to centuries, even with optimistic psychosociological parameter values, thereby positioning biotechnology as a proximate threat to human civilization. For an ensemble of civilizations having some median calculated survival time, the model predicts that, after 80 times that duration, only one in 1024 civilizations will survive – a tempo and degree of winnowing compatible with Hanson's ‘Great Filter.’ Thus, assuming that civilizations universally develop advanced biotechnology, before they become vigorous interstellar colonizers, the model provides a resolution to the Fermi paradox.


Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


2000 ◽  
Vol 406 ◽  
pp. 337-346 ◽  
Author(s):  
L. ENGEVIK

The instabilities of a free surface shear flow are considered, with special emphasis on the shear flow with the velocity profile U* = U*0sech2 (by*). This velocity profile, which is found to model very well the shear flow in the wake of a hydrofoil, has been focused on in previous studies, for instance by Dimas & Triantyfallou who made a purely numerical investigation of this problem, and by Longuet-Higgins who simplified the problem by approximating the velocity profile with a piecewise-linear profile to make it amenable to an analytical treatment. However, none has so far recognized that this problem in fact has a very simple solution which can be found analytically; that is, the stability boundaries, i.e. the boundaries between the stable and the unstable regions in the wavenumber (k)–Froude number (F)-plane, are given by simple algebraic equations in k and F. This applies also when surface tension is included. With no surface tension present there exist two distinct regimes of unstable waves for all values of the Froude number F > 0. If 0 < F [Lt ] 1, then one of the regimes is given by 0 < k < (1 − F2/6), the other by F−2 < k < 9F−2, which is a very extended region on the k-axis. When F [Gt ] 1 there is one small unstable region close to k = 0, i.e. 0 < k < 9/(4F2), the other unstable region being (3/2)1/2F−1 < k < 2 + 27/(8F2). When surface tension is included there may be one, two or even three distinct regimes of unstable modes depending on the value of the Froude number. For small F there is only one instability region, for intermediate values of F there are two regimes of unstable modes, and when F is large enough there are three distinct instability regions.


2005 ◽  
Vol 47 (2) ◽  
pp. 185-202 ◽  
Author(s):  
T. E. Stokes ◽  
G. C. Hocking ◽  
L. K. Forbes

AbstractThe unsteady axisymmetric withdrawal from a fluid with a free surface through a point sink is considered. Results both with and without surface tension are included and placed in context with previous work. The results indicate that there are two critical values of withdrawal rate at which the surface is drawn directly into the outlet, one after flow initiation and the other after the flow has been established. It is shown that the larger of these values corresponds to the point at which steady solutions no longer exist.


2007 ◽  
Vol 571 ◽  
pp. 359-370 ◽  
Author(s):  
JONATHAN J. WYLIE ◽  
HUAXIONG HUANG

In this paper we investigate the role played by viscous heating in extensional flows of viscous threads with temperature-dependent viscosity. We show that there exists an interesting interplay between the effects of viscous heating, which accelerates thinning, and inertia, which prevents pinch-off. We first consider steady drawing of a thread that is fed through a fixed aperture at given speed and pulled with a constant force at a fixed downstream location. For pulling forces above a critical value, we show that inertialess solutions cannot exist and inertia is crucial in controlling the dynamics. We also consider the unsteady stretching of a thread that is fixed at one end and pulled with a constant force at the other end. In contrast to the case in which inertia is neglected, the thread will always pinch at the end where the force is applied. Our results show that viscous heating can have a profound effect on the final shape and total extension at pinching.


2021 ◽  
Author(s):  
Daeha Kim ◽  
Jong Ahn Chun

&lt;p&gt;While the Budyko framework has been a simple and convenient tool to assess runoff (Q) responses to climatic and surface changes, it has been unclear how parameters of a Budyko function represent the vertical land-atmosphere interactions. Here, we explicitly derived a two-parameter equation by correcting a boundary condition of the Budyko hypothesis. The correction enabled for the Budyko function to reflect the evaporative demand (E&lt;sub&gt;p&lt;/sub&gt;) that actively responds to soil moisture deficiency. The derived two-parameter function suggests that four physical variables control surface runoff; namely, precipitation (P), potential evaporation (E&lt;sub&gt;p&lt;/sub&gt;), wet-environment evaporation (E&lt;sub&gt;w&lt;/sub&gt;), and the catchment properties (n). We linked the derived Budyko function to a definitive complementary evaporation principle, and assessed the relative elasticities of Q to climatic and land surface changes. Results showed that P is the primary control of runoff changes in most of river basins across the world, but its importance declined with climatological aridity. In arid river basins, the catchment properties play a major role in changing runoff, while changes in E&lt;sub&gt;p&lt;/sub&gt; and E&lt;sub&gt;w&lt;/sub&gt; seem to exert minor influences on Q changes. It was also found that the two-parameter Budyko function can capture unusual negative correlation between the mean annual Q and E&lt;sub&gt;p&lt;/sub&gt;. This work suggests that at least two parameters are required for a Budyko function to properly describe the vertical interactions between the land and the atmosphere.&lt;/p&gt;


2017 ◽  
Author(s):  
Amir M. S. Lala

Abstract. The most commonly used relationship relates permeability to porosity, grain size, and tortuosity is Kozeny–Carman formalism. When it is used to estimate the permeability behavior versus porosity, the other two parameters (the grain size and tortuosity) are usually kept constant. Here, we investigate the deficiency of the Kozeny–Carman assumption and offer alternative derived equations for the Kozeny–Carman equation, including equations where the grain size is replaced with the pore size and with varying tortuosity. We also introduced relationships for the permeability of shaly sand reservoir that answer the approximately linear permeability decreases in the log-linear permeability-porosity relationships in datasets from different locations.


Author(s):  
Duangui Wang

Formulation of the problem. In the chamber-vocal genre, the composer exists in two images: he is both the interpreter of the poetic composition and the author of a new synthetic music and poetic composition. The experience of the style analysis of one of the best examples of Ukrainian vocal lyrics of the first third of the 20th century shows that the cycle op. 20 characterizes the mature style of the composer, which was formed, on the one hand, under the influence of European Romanticism. On the other hand, the essence of the Ukrainian “branch” of the Western European song-romance (“solo-singing”) is revealed by the prominent national song-romance intonation, filled with not only a romantic worldview, but also with some personal sincerity, chastity, intimate involvement with the great in depth and simplicity poetry line, read from the individual position of the musician. The paradox is as follows. Although Pushkin’s poetry is embodied in a “holistic adequacy” (A. Khutorskaya), and the composer found the fullest semantic analogue of the poetic source, however, in terms of translating the text into the Ukrainian language, the musical semantics changes its intonation immanence, which naturally leads to inconsistency of the listeners’ position and ideas about the style of Russian romance. We are dealing with inter-specific literary translation: Pushkin’s discourse creates the Ukrainian romance style and system of figurative thinking. The purpose of the article is to reveal the principle of re-semantization of the intonation-figurative concept of the vocal composition by V. Kosenko (in the context of translating Pushkin’s poetry into the Ukrainian language) in light of the theory of interspecific art translation. Analysis of recent publications on the topic. Among the most recent studies of Ukrainian musicology, one should point out the dissertation by G. Khafizova (Kyiv, 2017), in which the theory of modelling of the stylistic system of the vocal composition as an expression of Pushkin’s discourse is described. The basis for the further stylistic analysis of V. Kosenko’s compositions is the points from A. Hutorska’s candidate’s thesis; she develops the theory of interspecific art translation. The types of translation of poetry into music are classified according to two parameters. The exact translation creates integral adequacy, which involves the composer’s finding a maximally full semantic analogue of the poetic source. The free translation is characterized by compensatory, fragmentary, generalized-genre adequacy. Presenting the main material. The Zhitomir period for Viktor Kosenko was the time of the formation of his creative style. Alongside the lyrical imagery line, the composer acquired one more – dramatic, after his mother’s death. It is possible that the romances on the poems of A. Pushkin are more late reflection of this tragic experience (op. 20 was created in 1930). “I Loved You” opens the vocal cycle and has been dedicated by A. V. Kosenko. The short piano introduction contains the intonation emblem of the love-feeling wave. The form of the composition is a two part reprising (А А1) with the piano Introduction and Postlude. The semantic culmination is emphasized by the change of metro-rhythmic organization 5/4 (instead of 4) and the plastic phrase “as I wish, that the other will love you” sounding in the text. Due to these melodies (with national segments in melo-types, rhythm formulas and harmony) V. Kosenko should be considered as “Ukrainian Glinka”, the composer who introduced new forms and “figures” of the love language into the romantic “intonation dictionary”. In general, V. Kosenko’s solo-singing represents the Ukrainian analogue of Pushkin’s discourse – the theme of love. The melos of vocal piece “I Lived through My Desires” is remembered by the broad breath, bright expression of the syntactic deployment of emotion. On the background of bass ostinato, the song intonation acquires a noble courage. This solo-singing most intermediately appeal to the typical examples of the urban romance of Russian culture of the 19th century. “The Raven to the Raven” – a Scottish folk ballad in the translation by A. Pushkin. V. Kosenko as a profound psychologist, delicately transmits the techniques of versification, following each movement of a poetic phrase, builds stages of the musical drama by purely intonation means. The semantics of a death is embodied through the sound imaging of a black bird: a marching-like tempo and rhythm of the accompaniment, with a characteristic dotted pattern in a descending motion (like a raven is beating its wings). The middle section is dominated by a slow-motion perception of time space (Andante), meditative “freeze” (size 6/4). The melody contrasts with the previous section, its profile is built on the principle of descending move: from “h1” to “h” of the small octave (with a stop on S-harmony), which creates a psychologically immersed state, filled by premonition of an unexpected tragedy. In general, the Ukrainian melodic intonation intensified the tragic content of the ballad by Pushkin. The musical semantics of V. Kosenko’s romances is marked by the dependence on the romantic “musical vocabulary”, however, it is possible to indicate and national characteristics (ascending little-sixth and fifth intervals, which is filled with a gradual anti-movement; syllabic tonic versification, and other). Conclusion. The romances (“solo-singings”) by V. Kosenko belongs to the type of a free art translation with generalized-genre adequacy. There is a re-semantization of poetic images due to the national-mental intonation. Melos, rhythm, textural presentation (repetitions), stylization of different genre formulas testify to the rare beauty of Kosenko’s vocal style, spiritual strength and maturity of the master of Ukrainian vocal culture. Entering the “Slavic song area”, the style of Ukrainian romance, however, is differenced from the Russian and common European style system of figurative and intonation thinking (the picture of the world).


Author(s):  
R. Randall Soper ◽  
Michael Scardina ◽  
Paul Tidwell ◽  
Charles Reinholtz ◽  
Michael A. Lo Presti

Abstract This paper presents a technique for synthesizing four-bar linkages to produce a specified resisting force or torque. The resisting energy is provided by a weight acting on the other grounded link. The linkage serves as a nonlinear mechanical advantage function generator. Force and velocity synthesis methods have been extensively discussed in the literature. The general approach, however, has been to assume that the specified force or velocity occurs at a prescribed position. This results in the loss of design parameters that are being used unnecessarily to control position. In this application, force input to the linkage is specified as a function of only the input link position and the magnitude and direction of the weight force. Mechanical advantage synthesis can be achieved at as many as seven precision points. The method presented in this paper allows free selection of two parameters and viewing one infinity of solutions.


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