Effect of technological factors on the structure and properties of Eskaplen film material

The effect of the composition of the solvents, the concentration of the solutions, and the rate of film formation on the structure and properties of Eskaplen film material obtained on the basis of SKI-3 isoprene rubber hydrochloride has been investigated. The properties of the film material are shown to depend on the structure that develops during the film-forming process.Moscow Technologic Institute of the Meat and Dairy Industry. Translated from Mekhanika Polimerov, No. 1, pp. 8–13, January–February, 1973.     

Thin-film flow over a nonlinear stretching sheet

A thin viscous liquid film flow is developed over a stretching sheet under different nonlinear stretching velocities. An evolution equation for the film thickness, is derived using long-wave approximation of thin liquid film and is solved numerically by using the Newton–Kantorovich method. A comparison is made with the analytic solution obtained in [B. S. Dandapat, A. Kitamura, B. Santra, “Transient film profile of thin liquid film flow on a stretching surface”, ZAMP, 57, 623-635 (2006)]. It is observed that all types of stretching produce film thinning but non-monotonic stretching produces faster thinning at small distance from the origin. The velocity u along the stretching direction strongly depends on the distance along the stretching direction and the Froude number.     

Thin-film flow over a nonlinear stretching sheet

A thin viscous liquid film flow is developed over a stretching sheet under different nonlinear stretching velocities. An evolution equation for the film thickness, is derived using long-wave approximation of thin liquid film and is solved numerically by using the Newton–Kantorovich method. A comparison is made with the analytic solution obtained in [B. S. Dandapat, A. Kitamura, B. Santra, “Transient film profile of thin liquid film flow on a stretching surface”, ZAMP, 57, 623-635 (2006)]. It is observed that all types of stretching produce film thinning but non-monotonic stretching produces faster thinning at small distance from the origin. The velocity u along the stretching direction strongly depends on the distance along the stretching direction and the Froude number.     

Two-stage biaxial orientation of polypropylene film

The microstructure of polypropylene film at various points of the two-stage orientation process is described. It is shown that the supermolecular structures and film properties vary with the method of orientation. A proposed mechanism of two-stage biaxial film orientation is based on the experimental results.Moscow M. V. Lomonosov Institute of Fine Chemical Technology. Translated from Mekhanika Polimerov, No. 4, pp. 735–737, July–August, 1969.     

An analysis of turbulent film condensation on a sphere with variable wall temperature under the effect of local shear stress

This paper presents an investigation into turbulent film condensation on a sphere with variable wall temperature. Under the wide range of vapor velocity, the wall temperature and the local film shear stress were considered. The result shows that under the high velocity vapor, the increase of the temperature amplitude will bring out a larger Nusselt number, and the increase is about 2.7–5.6%. Besides, under the effect of the local film shear stress, the mean Nusselt number will decrease about 0.65–0.8%. Furthermore, the paper then discusses the influence of shears and temperature amplitudes on the local dimensionless film thickness and heat transfer characteristics. Finally, the results developed in the current study are compared with those generated by previous theoretical results.     

Study of the effect of various factors on the low-temperature strength of polyethylene with graft polyacrylonitrile

Low-density polyethylene film has been subjected to graft polymerization with acrylonitrile. The effect of the graft polymerization conditions and subsequent treatment on the strength of the grafted film has been investigated. The strength was measured at -196°C. The grafted film behaves like a heterogeneous material in which the unoriented polyacrylonitrile macrostructures play the part of filler particles. The strength of the grafted film is additively composed of the strengths of the polyethylene and the polyacrylonitrile and the change in strength after stretching, heating, and other treatments is determined by the changes in the degree of orientation of the polyethylene.V. I. Lenin Belorussian State University, Minsk. Translated from Mekhanika Polimerov, No. 4, pp. 589–593, July–August, 1973.     

Study of a polyethylene terephthalate film by an acoustic method

The effect of orientation on the acoustic properties of a polyethylene terephthalate film is examined. In a crystallized, uniaxially oriented film the velocity of ultrasound measured along the orientation axis is lower than in an amorphous oriented film, while the velocity of ultrasound measured at angles of over 35° to the direction of orientation rises after crystallization. Evidently the supramolecular organization of the polyethylene terephthalate film before and after heat treatment is quite different.Scientific-Research Institute of Plastics, Moscow. Voronezh Branch of the Experimental Design Office of Automation. Translated from Mekhanika Polimerov, No. 4, pp. 759–761, July–August, 1972.     

Effect of quartz concentration and dispersity on the physico-mechanical properties of perchlorovinyl film

The structure of perchlorovinyl film is not affected by the addition of finely ground quartz. The modulus of elasticity and coefficient of thermal expansion of the film change additively with increase in filler concentration and do not depend on filler dispersity. The filler reduces the strength of the film and the elongation at break.Institute of Physical Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 6, pp. 1023–1027, November–December, 1969.     

Soap films and covering spaces

A new mathematical model of soap films is proposed, called the “covering space model.” The two sides of a film are modeled as currents on different sheets of a covering space branching along the film boundary. Hence a film may be seen as the minimal cut separating one sheet of the covering space from the others. The film is thus the oriented boundary of one sheet, which represents the exterior of the film. As oriented boundaries, films may be calibrated with differential forms on the covering space, a version of the min-cut, max-flow duality of network theory. This model applies to unoriented films, films with singularities, films touching only part of a knotted curve, films that deformation retract to their boundaries, and other examples that have proved troublesome for previous soap film models. Communicated by Frederick Almgren     

Transient film profile of thin liquid film flow on a stretching surface

In this paper we have studied a non-planar thin liquid film flow on a planar stretching surface. The stretching surface is assumed to stretch impulsively from rest and the effect of inertia of the liquid is considered. Equations describing the laminar flow on the stretching surface are solved analytically. It is observed that faster stretching causes quicker thinning of the film on the stretching surface. Velocity distribution in the liquid film and the transient film profile as functions of time are obtained. (Received: May 4, 2004; revised: February 2/August 24, 2005)     

A film coating on a rough surface of an elastic body

A solution of the plane problem of the theory of elasticity for a film–substrate composite is solved by a perturbation method for a substrate with a rough surface. An algorithm for calculating any approximation, which ultimately leads to the solution of the same Fredholm equation of the second kind, is given. Formulae for calculating the right-hand side of this equation, which depends on all the preceding approximations, are derived. An exact solution of the integral equation in the form of Fourier series, whose coefficients are expressed in quadratures, is given in the case of a substrate with a periodically curved surface. The stresses on the flat surface of the film and on the interfacial surface are found in a first approximation as functions of the form of bending of the surface, the mean thickness of the film and the ratio of Young's moduli of the film and the substrate. It is shown, in particular, that the greatest stress concentration on the film surface occures on a protrusion of the softer substrate. ©2013     

The inverse problem of estimating the film structure from X-ray reflection data

A new model of an X-ray reflection experiment is proposed for studying the structure of a film on a substrate. The experimental data are processed to yield the density distribution across the film, and an appropriate approximation produces numerical values of the parameters { δ_i, β_i, σ_i, d ₁} for each of the n layers in a multilayer film model. So far there has been no method for determining the film structure from experimental data and the problem has been usually solved by trial and error. __________ Translated from Prikladnaya Matematika i Informatika, No. 21, pp. 19–29, 2005.     

Near-wall gas-droplet flows with liquid-film formation

A self-consistent asymptotic theory of a near-wall aerodisperse flow with the formation of a liquid film due to inertial deposition of liquid droplets on the body surface is constructed. With the reference to the examples of low-speed mist flows near plane and curvilinear solid surfaces, asymptotically different situations are analyzed. The two-fluid equations of the mist flow are solved simultaneously with the equations of the liquid film, on the outer edge of which the distributed mass, momentum, and energy fluxes (found from the solution of the outer problem) are specified. It is shown that depending on the values of governing parameters the flow in the film should be described by either boundary-layer or creeping-flow equations in the layer with a priori unknown thickness. For the film on the frontal surface of a blunt body, the film thickness and the friction and heat transfer coefficients are found numerically. The conditions in which the presence of the film significantly reduces the heat fluxes are determined and the possibility of the realization of steady-state flow regimes in the film is demonstrated. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Analysis of double surface plasmon resonance by the discrete source method

The discrete source method is modified in order to mathematically simulate and study the scattering properties of nonspherical particles located on the surface of a conducting film deposited on a glass prism. Both differential and integral scattering properties of metal nanoparticles are examined. It is shown that the scattering cross section behind the film can be increased by 10⁷ times by deforming the particle and shifting it with respect to the film. It is also shown that the scattered intensity distribution in the prism is localized in two directions, forming sharp narrow fingers with the intensity exceeding the incident wave amplitude by 15–30 times.     

Exact solution of a thin film flow of an Oldroyd 6-constant fluid over a moving belt

We obtain exact solutions for thin film flow of an Oldroyd 6-constant fluid on a vertically moving belt. These are compared with the homotopy perturbation results of Siddiqui et al. [Siddiqui AM, Ahmed M, Ghori QK. Thin film flow of non-Newtonian fluids on a moving belt. Chaos, Solitons & Fractals 2007;33(3):1006–1016.].     

Early box office prediction in China’s film market based on a stacking fusion model

Artificial intelligence has been increasingly employed to improve operations for various firms and industries. In this study, we construct a box office revenue prediction system for a film at its early stage of production, which can help management overcome resource allocation challenges considering the significant investment and risk for the whole film production. In this research, we focus on China’s film market, the second-largest box office in the world. Our model is based on data regarding the nature of a film itself without word-of-mouth data from social platforms. Combining extreme gradient boosting, random forest, light gradient boosting machine, k-nearest neighbor algorithm, and stacking model fusion theory, we establish a stacking model for film box office prediction. Our empirical results show that the model exhibits good prediction accuracy, with its 1-Away accuracy being 86.46%. Moreover, our results show that star influence has the strongest predictive power in this model.

     

Films courbés minces ferromagnétiques

We consider a thin curved ferromagnetic film not submitted to an external magnetic field. The behavior of the film is described by an energy depending on the magnetization of the film verifying the saturation constraint. The energy is composed of an induced magnetostatic energy and an energy term with density including the exchange energy and the anisotropic energy. We study the behavior of this energy when the thickness of the curved film goes to zero. We show with Γ-convergence arguments that the minimizers of the free energy converge to the minimizers of a local energy depending on a two-dimensional magnetization. To cite this article: H. Zorgati, C. R. Acad. Sci. Paris, Ser. I 340 (2005).     

Effect of electrical discharges on the mechanical strength and molecular weight of polystyrene film

Electrically aged polystyrene film was examined to determine the effect of voltage, aging time, and nature of the medium on the mechanical strength and molecular weight. It was established that the changes in the mechanical strength and molecular weight of the film always correspond.Mekhanika Polimerov, Vol. 4, No. 1, pp. 59–63, 1968     

Investigation of the effect of an electrical field on the mechanical strength of polystyrene film

The effect of an electric field on the time dependence of the mechanical strength of a polystyrene (PS) film is investigated at different values of voltage and duration of exposure. It is found that at first the strength of the PS film drops with exposure to the electric field and then slowly increases.Mekhanika Polimerov, Vol. 1, No. 6, pp. 78–84, 1965     

Computational fluid dynamics simulation of aerodynamic performance and flow separation by single element and slatted airfoils under rainfall conditions

This study investigated the effects of rainfall on flow separation and the aerodynamic performance of single element and slatted NACA 0012 airfoils by using a mathematical model developed with the commercial computational fluid dynamics solver ANSYS FLUENT 18.2. A two-way momentum coupled Eulerian–Lagrangian multiphase approach was used to simulate the formation of the water film layer on the airfoil's surface. According to the results, very low values of the lift-to-drag ratio at low angles of attack reflected severe degradation of the aerodynamic performance of the airfoil in the presence of water accumulated on its surface. The impact of rain droplets on the leading-edge slat surface led to less water accumulating on the main section of the airfoil. In particular, the maximum water film mass concentrated on the airfoil surface decreased from 15 g to 1 g compared with the single element airfoil. Hence, the thickness of the water film layer was not sufficiently large to significantly affect the aerodynamic coefficients of the slatted airfoil, especially the maximum lift coefficient, compared with the thicker water film layer on the single element airfoil. In addition, the use of slats clearly enhanced the aerodynamic coefficients and increased the stall angle from 13° to 22° in dry conditions, and from 16° to 24° in rainy conditions. Slats also significantly decreased the boundary layer thickness and delayed the separation at higher angles of attack.