Search results for " tension"
showing 10 items of 270 documents
How do droplets on a surface depend on the system size?
2002
Abstract We investigate the thermodynamics of inhomogeneous polymer melts in the framework of a coarse grained off-lattice model. Properties of the liquid–vapour interface and the packing of the melt in contact with an attractive wall are considered. We employ Monte Carlo simulations in the grand canonical ensemble to determine excess free energies, the wetting temperature and the pre-wetting line, as well as the pre-wetting critical point. Having determined the wetting properties and the phase diagram of the model polymer, we perform canonical Monte Carlo simulations of small droplets on a surface. This allows us to study the dependence of droplet size on the wetting properties. It is foun…
M13_Microfluidics_for_CNT
2018
Compared to pure water, the CNT dispersion has much lower interfacial tension at the dispersion – glass interface due to the presence of SDBS surfactant. Since the behavior of microfluidic system in the confined regime is driven by liquid – solid interfacial tension, the droplet formation and droplet propagation are unstable and unpredictable.
The ensemble switch method for computing interfacial tensions
2015
We present a systematic thermodynamic integration approach to compute interfacial tensions for solid-liquid interfaces, which is based on the ensemble switch method. Applying Monte Carlo simulations and finite-size scaling techniques, we obtain results for hard spheres, which are in agreement with previous computations. The case of solid-liquid interfaces in a variant of the effective Asakura-Oosawa model and of liquid-vapor interfaces in the Lennard-Jones model are discussed as well. We demonstrate that a thorough finite-size analysis of the simulation data is required to obtain precise results for the interfacial tension.
Critical phenomena in colloid-polymer mixtures: interfacial tension, order parameter, susceptibility, and coexistence diameter.
2004
The critical behavior of a model colloid-polymer mixture, the so-called AO model, is studied using computer simulations and finite size scaling techniques. Investigated are the interfacial tension, the order parameter, the susceptibility and the coexistence diameter. Our results clearly show that the interfacial tension vanishes at the critical point with exponent 2\nu ~ 1.26. This is in good agreement with the 3D Ising exponent. Also calculated are critical amplitude ratios, which are shown to be compatible with the corresponding 3D Ising values. We additionally identify a number of subtleties that are encountered when finite size scaling is applied to the AO model. In particular, we find …
Importance of surface tension characterization for food, pharmaceutical and packaging products: a review.
2006
This article reviews the various theoretical approaches that have been developed for determination of the surface tension of solids, and the applications to food industrial products. The surface tension of a solid is a characteristic of surface properties and interfacial interactions such as adsorption, wetting or adhesion. The knowledge of surface tension is thus of great interest for every domain involved in understanding these mechanisms, which recover a lot of industrial investigations. Indeed, it is the case for the packaging industry, the food materials science, the biomedical applications and the pharmaceutical products, cleaning, adhesive technology, painting, coating and more gener…
Numerical and Experimental Analysis of Convection Transfer During Melting by a Mono-Pulsed Laser
2010
This paper presents a comparison between simulation and experimental results of the melting process of metallic material by a pulsed laser source Nd-YAG. Variations of the thermophysical properties were considered. Furthermore, the model included the effects of the surface-tension gradient on the fluid surface and the buoyancy force. The keyhole effect induced strong surface deformations and often formed cavities, which arre undesirable in the surface treatment process. An experimental study of the surface profile of the melted zones was also conducted to seek a relationship between the so-called keyhole effect and the laser triangulation measurements. The predicted Laser Melted Zone (LMZ) …
Corneal Oxygen Supply Conditions
1976
Pronounced cornea hypoxia induces swelling and a loss of transparency. Hypoxia of longer duration causes necrosis, particularly of the corneal endothelium. These findings were observed after ligation of the cilial arteries and the arteria carotis interna, after reduction of oxygen tension on the anterior corneal surface as well as after prolonged wearing of ill-fitted contact lenses (11, 15, 18, 22, 23). Because the normal function of the corneal endothelium plays a central role in maintaining transparency, an insufficient endothelial oxygen supply can directly influence vision (3, 17).
Mens sana in corpore exhausto. Emociones y gestión de sí en escuelas secundarias del sur global
2020
In recent years, emotional education has become a central element in a series of guidelines on a global scale that have been translated into various state initiatives aimed at education. Thus, Mens sana in corpore exhausto proposes to demonstrate the tension that is expressed between the growing series of discourses on emotional education and the school climate and the exhaustive bodies of teachers and directors of public secondary schools in the Metropolitan Region of Buenos Aires (RMBA). By way of hypothesis, these policies are considered to work on the bodies of teachers and directors, encouraging them to continue and not stop under the logic of management and self-management that throw …
Interfacial water structure controls protein conformation.
2007
A phenomenological theory of salt-induced Hofmeister phenomena is presented, based on a relation between protein solubility in salt solutions and protein-water interfacial tension. As a generalization of previous treatments, it implies that both kosmotropic salting out and chaotropic salting in are manifested via salt-induced changes of the hydrophobic/hydrophilic properties of protein-water interfaces. The theory is applied to describe the salt-dependent free energy profiles of proteins as a function of their water-exposed surface area. On this basis, three classes of protein conformations have been distinguished, and their existence experimentally demonstrated using the examples of bacter…
Novel technologies to detect atelectotrauma in the injured lung
2010
ABSTRACTCyclical recruitment and derecruitment of lung parenchyma (R/D) remains a serious problem in ALI/ARDS patients, defined as atelectotrauma. Detection of cyclical R/D to titrate the optimal respiratory settings is of high clinical importance. Image-based technologies that are capable of detecting changes of lung ventilation within a respiratory cycle include dynamic computed tomography (dCT), synchrotron radiation computed tomography (SRCT), and electrical impedance tomography (EIT). Time-dependent intra-arterial oxygen tension monitoring represents an alternative approach to detect cyclical R/D, as cyclical R/D can result in oscillations of PaO2 within a respiratory cycle. Continuous…