Surface Properties and Concentration Fluctuations in Sn-based Molten Alloys

2000 ◽  
Vol 55 (11-12) ◽  
pp. 967-972
Author(s):  
L. C. Prasad ◽  
V. N. Singh
Keyword(s):  
Surface Tension ◽  
Isothermal Compressibility ◽  
Reasonable Agreement ◽  
Surface Segregation ◽  
Concentration Fluctuations ◽  
Bulk Properties ◽  
Long Wavelength ◽  
Bulk Parameter ◽  
The Impact ◽  
The Ideal

Abstract A simple model based on the concept of a layered structure near the interface has been used to investigate the surface tension and surface segregation of SnPb and SnZn molten alloys. With increasing concentration of Sn, the surface tension (σ) of SnPb alloys has been found to increase, while a of SnZn alloys decreases, σ of both systems is smaller than the ideal value ΣCiσi. Our study reveals that both in SnPb and SnZn alloys the heavier atoms segregate towards the surface. The degree of segregation in SnZn alloys is greater than that in SnPb alloys. The Cahn-Hillard phenomenological model for the surface of pure liquids has been extended to binary molten mixtures and applied to the above systems. An attempt has been made to establish a link between the surface tension and the bulk properties such as concentration fluctuations in the long wavelength limit [Scc (0)] and isothermal compressibility (λT). The impact of the very sensitive bulk parameter Scc(0) has been examined. Reasonable agreement between our model and the experiment is observed for binary molten alloys such as SnPb in which the segregation is small, while for the SnZn alloys, in which the segregation is quite large, the agreement is not satisfactory.

On a nonlinear thermocapillary effect in thin liquid layers

1994 ◽  
Vol 273 ◽  
pp. 361-374 ◽  
Author(s):  
Alexander Oron ◽  
Philip Rosenau
Keyword(s):  
Thin Film ◽  
Surface Tension ◽  
Thermocapillary Effect ◽  
Spatiotemporal Evolution ◽  
Bulk Properties ◽  
Thin Liquid Layer ◽  
Dilute Aqueous Solutions ◽  
Marangoni Effects ◽  
The Impact ◽  
Film Interface

Dilute aqueous solutions of long alcohol chains were recently found to cause a quadratic dependence of surface tension on the temperature without affecting other bulk properties of the liquid: σ = σ0 + αQ(T − T0)2, αQ > 0. The impact of such Marangoni instability on the behaviour of a thin liquid layer is studied in this work. We derive an equation describing a nonlinear spatiotemporal evolution of a thin film. The behaviour of the perturbed film in the absence of gravity, critically depends on whether the temperature T0, yielding a minimal surface tension, is attained on the surface of the film. When this is the case, a qualitatively new behaviour is observed: perturbations of the film interface may evolve into continuous steady patterns that do not rupture. Otherwise, the observed patterns due to the linear and quadratic Marangoni effects are qualitatively similar and result in the rupture of the film into separate drops.

The Impact of the Industrial Processing of Oil on the Rainfall Water Quality

2017 ◽  
Vol 68 (1) ◽  
pp. 175-179
Author(s):  
Oana Roxana Chivu ◽  
Augustin Semenescu ◽  
Claudiu Babis ◽  
Catalin Amza ◽  
Gabriel Iacobescu ◽  
...  
Keyword(s):  
Water Quality ◽  
Sulfuric Acid ◽  
Experimental Research ◽  
Air Purification ◽  
High Toxicity ◽  
Industrial Processing ◽  
Mobile Sources ◽  
Specific Activities ◽  
The Impact ◽  
The Ideal

Rainfall is a major component of the environment and the main source of the air purification becouse of many pollutants increases who have the most varied sources: various human activities including industry and agriculture, and some household duties. Air purification by means of precipitation is achieved by numerous highly complex mechanisms. The final products of degradation of the pollutant in the air, which are generally harmless, can be reacted with each other in the presence of water, giving rise to the final compounds with a high toxicity. Thus, exhaust, mobile sources of noxious almost identical to those specific activities in the industrial processing of oil, contain lead which is the ideal catalyst for converting SO2 to sulfuric acid in the presence of rainwater, with all the disadvantages that they create. This paper will present an experimental research oabout how rainfall water quality is influenced by the activity of the industrial processing of oil, in a chemical plant in Constanta County.

scholarly journals Buoyancy control in ammonoid cephalopods refined by complex internal shell architecture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David J. Peterman ◽  
Kathleen A. Ritterbush ◽  
Charles N. Ciampaglio ◽  
Erynn H. Johnson ◽  
Shinya Inoue ◽  
...  
Keyword(s):  
Surface Tension ◽  
Water Retention Capacity ◽  
Functional Explanation ◽  
Retention Capacity ◽  
Biomechanical Stress ◽  
Liquid Retention ◽  
3D Printed ◽  
Functional Explanations ◽  
Hydrophilic Coatings ◽  
The Impact

AbstractThe internal architecture of chambered ammonoid conchs profoundly increased in complexity through geologic time, but the adaptive value of these structures is disputed. Specifically, these cephalopods developed fractal-like folds along the edges of their internal divider walls (septa). Traditionally, functional explanations for septal complexity have largely focused on biomechanical stress resistance. However, the impact of these structures on buoyancy manipulation deserves fresh scrutiny. We propose increased septal complexity conveyed comparable shifts in fluid retention capacity within each chamber. We test this interpretation by measuring the liquid retained by septa, and within entire chambers, in several 3D-printed cephalopod shell archetypes, treated with (and without) biomimetic hydrophilic coatings. Results show that surface tension regulates water retention capacity in the chambers, which positively scales with septal complexity and membrane capillarity, and negatively scales with size. A greater capacity for liquid retention in ammonoids may have improved buoyancy regulation, or compensated for mass changes during life. Increased liquid retention in our experiments demonstrate an increase in areas of greater surface tension potential, supporting improved chamber refilling. These findings support interpretations that ammonoids with complex sutures may have had more active buoyancy regulation compared to other groups of ectocochleate cephalopods. Overall, the relationship between septal complexity and liquid retention capacity through surface tension presents a robust yet simple functional explanation for the mechanisms driving this global biotic pattern.

scholarly journals The impact of huts on physiological stress: a refinement in post-transport housing of male guineapigs (Cavia porcellus)

2012 ◽  
Vol 46 (3) ◽  
pp. 220-224 ◽  
Author(s):  
Sherry L Walters ◽  
Cristobal Jose Torres-Urbano ◽  
Lee Chichester ◽  
Robert E Rose
Keyword(s):  
Animal Welfare ◽  
Physiological Stress ◽  
Cortisol Concentration ◽  
Experimental Science ◽  
Housing Environment ◽  
Confounding Variables ◽  
Animal Use ◽  
Acclimatization Period ◽  
The Impact ◽  
The Ideal

The ideal animal model would contribute no confounding variables in experimental science. Variables affect experimental design resulting in increased animal use or repeated studies. We demonstrated a simple refinement which may reduce the number of animals used experimentally while simultaneously improving animal welfare. The objective of this study was to determine if the presence of a hut was an impact on physiological stress levels, as determined by faecal cortisol concentration, during a routine four-day acclimatization period of newly received male Hartley-Outbred guineapigs. We hypothesized that those animals provided with huts would have decreased physiological stress compared with animals not provided with huts. We examined this effect within both paired and single-housed animals. A between-subjects one-way analysis of variance revealed that pair-housed animals with a hut had significantly lower faecal cortisol concentration than pair-housed animals without a hut and the presence and absence of a hut had no significant impact on faecal cortisol concentration in single-housed animals. These findings show that presence of a hut is beneficial in reducing physiological stress when pair housing male guineapigs and does not appear to have an impact when single housing male guineapigs. In addition, we have shown that faecal cortisol, and therefore physiological stress, is still increasing on study day 4 suggesting a longer acclimatization period is necessary. A simple refinement in housing environment and acclimatization time can both reduce the number of animals used experimentally and improve animal welfare.

scholarly journals Long-Wavelength Instability in Surface-Tension-Driven Bénard Convection

1995 ◽  
Vol 75 (24) ◽  
pp. 4397-4400 ◽  
Author(s):  
Stephen J. VanHook ◽  
Michael F. Schatz ◽  
William D. McCormick ◽  
J. B. Swift ◽  
Harry L. Swinney
Keyword(s):  
Surface Tension ◽  
Long Wavelength ◽  
Bénard Convection ◽  
Benard Convection

On the Impact of the Operational Profile on the Ideal Design of a Diving Support Offshore Construction Vessel

2008 ◽  
Vol 45 (02) ◽  
pp. 77-88
Author(s):  
Erlend Hovland
Keyword(s):  
North Sea ◽  
Economical Analysis ◽  
Operational Profile ◽  
Working Day ◽  
The Impact ◽  
The Ideal

Simplified technical and economical analysis of a total of 12 different ship designs has been performed and compared with operational profiles of typical North Sea Diving and Construction vessels. Evaluation of what impact changes to the operational profile has on the best-suited vessel for the operation has also been performed. The paper focuses on optimizing the design to achieve a maximum of days in operation working day. Nomenclature

Gobernanza económica europea y modelo territorial de distribución del poder

2013 ◽  
pp. 153-191
Author(s):  
Ainhoa LASA LÓPEZ
Keyword(s):  
European Union ◽  
The European Union ◽  
European Level ◽  
Euro Pean ◽  
Economic Constitution ◽  
The One ◽  
The Impact ◽  
The Relationship ◽  
The Ideal

LABURPENA: Artikulu honetan, Europar Batasuneko botere-artikulazio berriak erkidegotan osatutako Espainian zer eragin daukan aztertuko dugu. Europa mailako politika-ekonomia erlazioak funtsezko bi koordenatu izan behar ditu ezinbestean. Alde batetik, Europako konstituzio-ordena ez dela gizartearen konstituzionalismoaren koordenatuetan ernatutako ordenaren berdina. Bestetik, Europako konstituzio ekonomikoa Europa bat egiteko proiektuak berarekin dakartzan aldaketa berriak gorpuzteko eremua dela. Izan ere, funtsean, Europako konstituzio ekonomikoa plataforma ezin hobea delako boterearen artikulazioa berria nola artikulatu asmatzeko, Europa guztirako. RESUMEN: el objetivo de este artículo es analizar el impacto que tiene la nueva articulación del poder en la Unión Europea en el Estado español de las autonomías. La relación política-economía a nivel europeo debe tener en cuenta dos coordenadas fundamentales. Por una parte, la consideración del orden constitucional europeo como un orden distinto al gestado bajo las coordenadas del constitucionalismo social. Por otra, la caracterización de la constitución económica europea como ámbito de materialización de las nuevas transformaciones que incorpora el proyecto de integración europeo. Fundamentalmente, porque la constitución económica europea representa la plataforma idónea desde la que dilucidar la nueva articulación del poder desde el espacio supranacional europeo. ABSTRACT: The aim of this paper is to analyse the impact of the new articula tion of power in the European Union in the Spanish state of autonomies. The relationship between politics and economy at European level must take into consideration two fundamental coordinates. On the one hand, the Euro pean constitucional system appears as a system opposite to that of social constitutionalism. Moreover, the characterization of the European economic constitution as a field of realization of the new transformations incorporated by the European project. Specially, because this represents the ideal platform in order to analyse the new articulation of power from European supranational space.

Interaction of Shroud Leakage Flow and Main Flow in a Three-Stage LP Turbine

2003 ◽  
Vol 127 (4) ◽  
pp. 649-658 ◽  
Author(s):  
Jochen Gier ◽  
Bertram Stubert ◽  
Bernard Brouillet ◽  
Laurent de Vito
Keyword(s):  
Main Flow ◽  
Secondary Flows ◽  
Test Facility ◽  
Navier Stokes ◽  
Leakage Flow ◽  
Jet Engines ◽  
Flow Interactions ◽  
Lp Turbine ◽  
The Impact ◽  
The Ideal

Endwall losses significantly contribute to the overall losses in modern turbomachinery, especially when aerodynamic airfoil load and pressure ratios are increased. In turbines with shrouded airfoils a large portion of these losses are generated by the leakage flow across the shroud clearance. Generally the related losses can be grouped into losses of the leakage flow itself and losses caused by the interaction with the main flow in subsequent airfoil rows. In order to reduce the impact of the leakage flow and shroud design related losses a thorough understanding of the leakage losses and especially of the losses connected to enhancing secondary flows and other main flow interactions has to be understood. Therefore, a three stage LP turbine typical for jet engines is being investigated. For the three-stage test turbine 3D Navier-Stokes computations are performed simulating the turbine including the entire shroud cavity geometry in comparison with computations in the ideal flow path. Numerical results compare favorably against measurements carried out at the high altitude test facility at Stuttgart University. The differences of the simulations with and without shroud cavities are analyzed for several points of operation and a very detailed quantitative loss breakdown is presented.

scholarly journals The Impact of Media in the Socialization Process in Albania

2014 ◽  
Vol 1 (1) ◽  
pp. 149
Author(s):  
Bukurie Lila
Keyword(s):  
Young Adults ◽  
Young People ◽  
Mass Media ◽  
Positive Function ◽  
Main Question ◽  
Negative Effects ◽  
Socialization Process ◽  
The Media ◽  
The Impact ◽  
The Ideal

Media is one of the main agents of socialization that affects youth the most. Young adults are majority time are surrounded by the media, which brings me to my main question, "How is Mass Media Affecting Socialization in Children and Young Adults in Albania?" To understand this question one must know and understand what socialization is. The socialization process is a very dramatic impact on a child's life. Socialization is a "Continuing process whereby an individual acquires a personal identity and learns the norms, values, behavior, and social skills appropriate to his or her social position". Mass media has enormous effects on our attitudes and behavior which makes it an important contributor to the socialization process. in some ways mass media can serve as a positive function. It helps there to be more diversity, we can learn more about things that are going on in different countries. It can help you learn new things you did not know. Sadly Media can serve as a negative function in young people life. Young people want to be accepted by society and the media creates the ideal image that tells you what the characteristics are to be accepted and to be able to fit in with society. They show what you should look like, how you can look like this, and where to go to buy these things that will make you look right. This is why many young women deal with anorexia because they want to look like the ideal type that the media displays. Media also influences young people to misbehave. Media shows that being deviant makes you cool and look tough and that it's okay to do deviant things. Statistics show that when young people watch violence on television it increases their appetites to become involved in violence. It opens their minds to violence and makes them aware of crimes and people acting deviant. Many people think that the media does not play a role in the socialization process as much as family, peers and education. But in fact the media plays a strong role in the socialization process. The aim of this study is to see the positive and negative effects that the Albanian media plays in the socialization process in Albania.

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