scholarly journals Finite Element Method for Thin Film Corrosion Modelling: Where We Advanced and Where We would like to Advance?

2020 ◽  
Vol 1 (2) ◽  
pp. 273-281
Author(s):  
Mohsen Saeedikhani ◽  
Daniel John Blackwood
Keyword(s):  
Thin Film ◽  
Finite Element Method ◽  
Experimental Studies ◽  
Environmental Parameters ◽  
Electrolyte Composition ◽  
Electrode Size ◽  
Corrosion Rates ◽  
Corrosion Model ◽  
Corrosion Modelling ◽  
The Many

Thin film corrosion is a serious issue in almost every sector. Thus, simulation of corrosion under thin electrolyte films has always been of high interest as experimental studies are often challenging. Thus far, progress has been made to model the effect of several important factors on thin film corrosion rates. Some of these parameters are electrolyte thickness, electrolyte composition, chemical reactions in the electrolyte, electrode size and change in electrode size, environmental parameters, and corrosion products deposition. However, these parameters are mainly drawn from different studies and have not been modelled concurrently in a single simulation study, making the thin film corrosion model far from being complete yet. Therefore, despite the many efforts so far, thin film corrosion modelers still strive to push the modelling edges further. This paper takes into account some of the highlighted recent advances in thin film corrosion modelling based on the mentioned parameters to provide a perspective on not only how far the field has come, but also how far it still is from a complete thin film corrosion model. Discussions have also been made on future needs and prospects to advance the thin film corrosion models further.

ИССЛЕДОВАНИЕ МАГНИТОРЕЗИСТИВНЫХ НАНОСТРУКТУР С МАГНИТОСТРИКЦИОННЫМ ЭФФЕКТОМ ДЛЯ УСТРОЙСТВ МАГНИТНОЙ СТРЕЙНТРОНИКИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 420-423
Author(s):  
Д.А. Жуков ◽  
В.В. Амеличев ◽  
Д.В. Костюк ◽  
А.И. Крикунов ◽  
Д.В. Васильев ◽  
...  
Keyword(s):  
Thin Film ◽  
Experimental Studies ◽  
Silicon Substrates ◽  
Multilayer Nanostructures ◽  
Magnetoresistive Effect ◽  
Anisotropic Magnetoresistive Effect

Представлены результаты экспериментальных исследований магнитострикционных и магниторезистивных свойств тонкопленочных многослойных наноструктур Ta/FeNiCo/CoFe/Ta и Ta/FeNiCo/CoFeВ/Ta на окисленных кремниевых подложках диаметром 100 мм. Экспериментально установлена зависимость величины анизотропного магниторезистивного эффекта от величины механических деформаций в экспериментальных образцах наноструктур. The paper presents the results of experimental studies of the magnetostriction and magnetoresistive properties of thin-film multilayer nanostructures Ta/FeNiCo/CoFe/Ta and Ta/FeNiCo/CoFeB/Ta on oxidized silicon substrates with a diameter of 100 mm. The dependence of the magnitude of the anisotropic magnetoresistive effect on the magnitude of mechanical strains in experimental samples of nanostructures has been experimentally established.

scholarly journals Finite Element Prediction for the Internal Stresses of (Ti,Al)N Coatings

2016 ◽  
Vol 61 (1) ◽  
pp. 149-152 ◽  
Author(s):  
L.W. Żukowska ◽  
A. Śliwa ◽  
J. Mikuła ◽  
M. Bonek ◽  
W. Kwaśny ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Computer Simulation ◽  
Finite Element ◽  
Experimental Studies ◽  
Single Layer ◽  
Internal Stresses ◽  
Pvd Coatings ◽  
Properties Of Coatings ◽  
Gradient Coatings ◽  
Element Method

The general topic of this paper is the computer simulation with use of finite element method (FEM) for determining the internal stresses of selected gradient and single-layer PVD coatings deposited on the sintered tool materials, including cemented carbides, cermets and Al2O3+TiC type oxide tool ceramics by cathodic arc evaporation CAE-PVD method. Developing an appropriate model allows the prediction of properties of PVD coatings, which are also the criterion of their selection for specific items, based on the parameters of technological processes. In addition, developed model can to a large extent eliminate the need for expensive and time-consuming experimental studies for the computer simulation. Developed models of internal stresses were performed with use of finite element method in ANSYS environment. The experimental values of stresses were calculated using the X-ray sin2ψ technique. The computer simulation results were compared with the experimental results. Microhardness and adhesion as well as wear range were measured to investigate the influence of stress distribution on the mechanical and functional properties of coatings. It was stated that occurrence of compressive stresses on the surface of gradient coating has advantageous influence on their mechanical properties, especially on microhardness. Absolute value reduction of internal stresses in the connection zone in case of the gradient coatings takes profitably effects on improvement the adhesion of coatings. It can be one of the most important reasons of increase the wear resistance of gradient coatings in comparison to single-layer coatings.

THE INFLUENCE OF AGE ON PERFORMANCE AS SHOWN BY EXERCISE TESTS

PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 737-741
Author(s):  
D. B. Dill
Keyword(s):  
Work Performance ◽  
Experimental Studies ◽  
Business Administration ◽  
Distance Runner ◽  
Indiana University ◽  
Exercise Tests ◽  
The Subject ◽  
To Come ◽  
The Many ◽  
Harvard School

THE STUDY of work performance as related to age began in this country when Sid Robinson joined the group at the Fatigue Laboratory of the Harvard School of Business Administration. In the winter of 1936-7, he persuaded five champion milers who were in Boston for indoor meets to run on the Laboratory's treadmill on week-ends. Simultaneously, he was chiefly engaged in studying treadmill performance as related to age. This was the subject of his doctorate thesis published later under the title: "Experimental Studies of Physical Fitness as Related to Age". The 91 subjects ranged in age from boys 6 years of age to one man of 91. There were eight 6-year-olds, 10 between 8 and 13 and 20 between 48 and 76. Robinson's background as an Olympic middle-distance runner and as an assistant track coach at Indiana University gave him skill in dealing with the many diverse problems that confronted him. Often he was faced with sociological-psychological problems more difficult to solve than the physiological problems. Indicative of his success is the fact that the subjects were volunteers—no money was offered as an inducement to come to the laboratory. Also worthy of note is that there was no untoward incident throughout the study. Robinson's plan included respiratory, circulatory and metabolic observations in the basal state and in two grades of exercise. He describes the work experiments as follows: (pp. 251-3, reference 2) "After the above observations were completed, the subject performed two grades of work on a motor-driven treadmill, set at an angle of 8.6% in all experiments. Each subject below 73 years of age first walked at 5.6 km per hour for 15 minutes; this raises the oxygen consumption 7 or 8 times the basal level. After resting 10 minutes, he ran or in some cases, walked, at a rate which exhausted him in 2 to 5 minutes.

Reactive Phase Formation in Thin Films: Evolution of Grain Structure

1995 ◽  
Vol 403 ◽  
Author(s):  
K. Barmak ◽  
C. Michaelsent ◽  
J. Rickman ◽  
M. Dahmstt
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Formation ◽  
Experimental Studies ◽  
Grain Structure ◽  
Structure Evolution ◽  
Future Research ◽  
Polycrystalline Materials ◽  
Product Phase ◽  
Nucleation Kinetics

AbstractIt is a well known fact that the properties and performance of polycrystalline materials, including polycrystalline thin films, are strongly affected by the grain structure. Therefore, in treating reactive phase formation in these films, it is (or it will inevitably be) necessary to quantify the grain structure of reactant and product phases and its evolution during the course of the reaction. Theoretical models and the conventional view of thin film reactions, however, have been largely extensions, to small and finite dimensions, of theories and descriptions developed for bulk diffusion couples. These models and descriptions primarily focus on the growth stage and to a much lesser extent on the nucleation stage. Consequently, these models and descriptions are not able to treat the development of product phase grain structure. Recent calorimetric investigations of several thin film systems demonstrate the importance of nucleation kinetics (and hence nucleation barriers) in product phase formation and provide quantitative measures of the thermodynamics and kinetics of formation of the product phases, thereby allowing some degree of comparison with reaction models. Furthermore, microstructural investigations of thin-film reactions demonstrate the non-planarity of the growth front and highlight the role of reactant-phase grain boundaries. In this paper, a summary of these experimental studies and recent theoretical treatments, which combine nucleation and growth in an integrated manner, is presented, with particular emphasis on the Nb/Al system. These experiments and models lead to a new view of reactive phase formation and grain structure evolution as one in which the latter is an integral part of the former. Based on this view, directions for future research are discussed.

scholarly journals ANÁLISE NUMÉRICA DE PERFIS DE AÇO FORMADOS A FRIO EM SEÇÃO “I” CONSTITUÍDA POR DUPLO “U” SUBMETIDOS À COMPRESSÃO

2020 ◽  
Vol 12 (1) ◽  
pp. 95-110
Author(s):  
Gabriel Cintra Macedo ◽  
Wanderson Fernando Maia
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Plate Thickness ◽  
Experimental Studies ◽  
Structural Behavior ◽  
The Finite Element Method ◽  
Geometric Imperfections ◽  
Initial Geometric Imperfections ◽  
Normal Strength ◽  
Double Channel

Although the section “I”, in double channel, is widely used, there are few studies on its behavior. Therefore, this work aims to contribute to a greater mastery over the structural behavior of this built-up sections. A nonlinear numerical analysis was performed using the Finite Element Method in the Ansys program, using existing experimental studies as a comparative database. The effect of length, number of connections, plate thickness and the presence of geometric and material imperfections on the normal strength of the columns. For this analysis, it was essential to consider the initial geometric imperfections, because there was a considerable reduction in the normal strength of the columns, thus getting closer to the values obtained experimentally. With regard to normative procedures, values against security were found in most cases, showing the need to conduct further studies in the area for the development of more appropriate formulations.

EXPERIMENTAL STUDIES OF THE INFLUENCE OF THIN-FILM COATINGS ON THE RESISTANCE OF THE TOOL

2020 ◽  
Vol 5 ◽  
pp. 55-60
Author(s):  
G.V. BARSUKOV ◽  
A.V. KIRICHEK ◽  
K.F. SELEMENEV ◽  
E.M. SELEMENEVA
Keyword(s):  
Thin Film ◽  
Experimental Studies ◽  
Cutting Fluids ◽  
Adhesive Interaction ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Rigid Contact

The article deals with the problems of increasing the efficiency of centrifugal processing with a rigid contact. It is shown that when materials with different properties interact, it is energetically "advantageous" to have a discontinuous contact between interacting elements of the surfaces of the tool and the part. It has been established that epilating the working surfaces of the tool significantly changes the nature of the resistance to adhesive interaction, the effectiveness of which is significantly increased when using cutting fluids (lubricating and cooling technological media).

scholarly journals Hesperidin and SARS-CoV-2: New Light on the Healthy Function of Citrus Fruits

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 742
Author(s):  
Paolo Bellavite ◽  
Alberto Donzelli
Keyword(s):  
Immune System ◽  
Binding Energy ◽  
Computational Methods ◽  
Experimental Studies ◽  
Citrus Fruit ◽  
Short Review ◽  
Viral Disease ◽  
Antiviral Action ◽  
Citrus Fruits ◽  
The Many

Among the many approaches to Coronavirus disease 2019 (COVID-19) prevention, the possible role of nutrition has so far been rather underestimated. Foods are very rich in substances, with a potential beneficial effect on health, and some of these could have an antiviral action or be important in modulating the immune system and in defending cells from the oxidative stress associated with infection. This short review draws the attention on some components of citrus fruits, and especially of the orange (Citrus sinensis), well known for its vitamin and flavonoid content. Among the flavonoids, hesperidin has recently attracted the attention of researchers, because it binds to the key proteins of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several computational methods, independently applied by different researchers, showed that hesperidin has a low binding energy, both with the coronavirus “spike” protein, and with the main protease that transforms the early proteins of the virus (pp1a and ppa1b) into the complex responsible for viral replication. The binding energy of hesperidin to these important components is lower than that of lopinavir, ritonavir, and indinavir, suggesting that it could perform an effective antiviral action. Furthermore, both hesperidin and ascorbic acid counteract the cell damaging effects of the oxygen free radicals triggered by virus infection and inflammation. There is discussion about the preventive efficacy of vitamin C, at the dose achievable by the diet, but recent reviews suggest that this substance can be useful in the case of strong immune system burden caused by viral disease. Computational methods and laboratory studies support the need to undertake apposite preclinical, epidemiological, and experimental studies on the potential benefits of citrus fruit components for the prevention of infectious diseases, including COVID-19.

scholarly journals Majority Voting Based Multi-Task Clustering of Air Quality Monitoring Network in Turkey

2019 ◽  
Vol 9 (8) ◽  
pp. 1610
Author(s):  
Goksu Tuysuzoglu ◽  
Derya Birant ◽  
Aysegul Pala
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Clustering Algorithms ◽  
Experimental Studies ◽  
Monitoring Network ◽  
Environmental Parameters ◽  
Global Scale ◽  
Majority Voting ◽  
Clustering Methods ◽  
Task Clustering

Air pollution, which is the result of the urbanization brought by modern life, has a dramatic impact on the global scale as well as local and regional scales. Since air pollution has important effects on human health and other living things, the issue of air quality is of great importance all over the world. Accordingly, many studies based on classification, clustering and association rule mining applications for air pollution have been proposed in the field of data mining and machine learning to extract hidden knowledge from environmental parameters. One approach is to model a region in a way that cities having similar characteristics are determined and placed into the same clusters. Instead of using traditional clustering algorithms, a novel algorithm, named Majority Voting based Multi-Task Clustering (MV-MTC), is proposed and utilized to consider multiple air pollutants jointly. Experimental studies showed that the proposed method is superior to five well-known clustering algorithms: K-Means, Expectation Maximization, Canopy, Farthest First and Hierarchical clustering methods.

SERS of a-C Thin Film on Ag, Au, Ag0.52-Au0.48 Alloy Nanoparticle Arrays with Normal Particles Size Distribution Formed by Vacuum Thermal Evaporation

2018 ◽  
Vol 386 ◽  
pp. 250-255 ◽  
Author(s):  
Sergey Dubkov ◽  
Alexey Trifonov ◽  
Yuri Shaman ◽  
Evgeny Kitsyuk ◽  
Andrey Savitskiy ◽  
...  
Keyword(s):  
Thin Film ◽  
Particle Size ◽  
Raman Scattering ◽  
Size Distribution ◽  
Thermal Evaporation ◽  
Experimental Studies ◽  
Alloy Nanoparticles ◽  
Nanoparticle Arrays ◽  
Vacuum Thermal Evaporation ◽  
Particles Size Distribution

This paper presents the results of experimental studies of arrays of Ag0.52Au0.48 alloy nanoparticles. Arrays were formed by vacuum-thermal evaporation on an unheated substrate and subsequent low-temperature vacuum annealing. The TEM images of the obtained nanoparticle arrays and corresponding histograms of particle size distribution are shown. The transmission spectra of these arrays showing the displacement of the plasma frequency as a function of the mean particle size are obtained. Spectra of Raman scattering from a thin film of amorphous carbon in presence of AgAu particles are obtained, and a comparative analysis of Raman scattering amplification factors for pure Ag, pure Au and Ag0.52Au0.48 alloy nanoparticles is presented.

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