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Article
Publication date: 30 April 2024

Sangryul Go

The purpose of this study is to investigate the accumulation process of transfer film formation and dissipation and its effect on friction coefficients in non asbestos organic…

Abstract

Purpose

The purpose of this study is to investigate the accumulation process of transfer film formation and dissipation and its effect on friction coefficients in non asbestos organic friction materials with various lubricant FeS2 contents.

Design/methodology/approach

In total, 2.5%, 5% and 10% FeS2 were added as lubricating components to the friction materials. Friction tests composed of two stages were conducted for these friction materials, and the friction surfaces of the counterpart discs were examined using scanning electron microscopy.

Findings

The transfer film formation reduced the friction coefficients, and the transfer film dissipation influenced the recovery of the friction coefficients. The effect of a high content of FeS2 was to promote the transfer film formation at high temperatures and to hinder the transfer film dissipation at low temperatures, thus resulting in a decrease in the friction coefficients at high temperatures together with recovery retardation at low temperatures.

Originality/value

FeS2 contributed to the transfer film formation at high temperatures in the fade test but hindered the transfer film removal in the recovery test, resulting in the retardation of friction coefficient recovery. The mechanism by which the FeS2 lubricant component affected the transfer film formation and dissipation was analyzed and attributed to the different levels of FeS2 pyrolysis at different temperature levels.

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 8 May 2024

Mengyao Fan, Xiaojing Ma, Lin Li, Xinpeng Xiao and Can Cheng

In this paper, the complex flow evaporation process of droplet impact on the liquid film in a horizontal falling film evaporator is numerically studied based on smoothed particle…

Abstract

Purpose

In this paper, the complex flow evaporation process of droplet impact on the liquid film in a horizontal falling film evaporator is numerically studied based on smoothed particle hydrodynamics (SPH) method. The purpose of this paper is to present the mechanism of the water treatment problem of the falling film evaporation for the high salinity mine water in Xinjiang region of China.

Design/methodology/approach

To effectively characterize the phase transition problem, the particle splitting and merging techniques are introduced. And the particle absorbing layer is proposed to improve the nonphysical aggregation phenomenon caused by the continuous splitting of gas phase particles. The multiresolution model and the artificial viscosity are adopted.

Findings

The SPH model is validated qualitatively with experiment results and then applied to the evaporation of the droplet impact on the liquid film. It is shown that the larger single droplet initial velocity and the smaller single droplet initial temperature difference between the droplet and liquid film improve the liquid film evaporation. The heat transfer effect of a single droplet is preferable to that of multiple droplets.

Originality/value

A multiphase SPH model for evaporation after the droplet impact on the liquid film is developed and validated. The effects of different factors on liquid film evaporation, including single droplet initial velocity, single droplet initial temperature and multiple droplets are investigated.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 6 May 2024

Shan Gao, Bin Wang, Xinjie Yao and Quan Yuan

This paper aims to characterize the surface film formed on Alloys 800 and 690 in chloride and thiosulfate-containing solution at 300°C.

Abstract

Purpose

This paper aims to characterize the surface film formed on Alloys 800 and 690 in chloride and thiosulfate-containing solution at 300°C.

Design/methodology/approach

Alloy 800 and 690 were immersed in chloride and thiosulfate-containing solution at 300°C up to five days, and then the surface film was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray spectrometers (EDX).

Findings

Through static immersion experiments in a high-temperature and high-pressure water environment, the alloy samples covered by surface film after five days of immersion were obtained. The morphology of the surface film was characterized at both horizontal and cross-sectional scales using SEM and focused ion beam-TEM techniques. It was observed that due to the influence of the quartz lining, the surface film primarily exhibited a bilayered structure. The first layer contained a significant amount of SiO2, with a higher content of metal hydroxides compared to metal oxides. The second layer was predominantly composed of Fe, Ni and Cr, with a higher content of metal oxides compared to metal hydroxides.

Originality/value

The results showed that the materials of the lining of the autoclave could significantly influence the film composition of the tested material, which should be paid attention when analyzing the corrosion mechanism at high temperature.

Details

Anti-Corrosion Methods and Materials, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 19 February 2024

Bassem Assfour, Bassam Abdallah, Hour Krajian, Mahmoud Kakhia, Karam Masloub and Walaa Zetoune

The purpose of this study is to investigate the structural, surface roughness and corrosion properties of the zirconium oxide thin films deposited onto SS304 substrates using the…

Abstract

Purpose

The purpose of this study is to investigate the structural, surface roughness and corrosion properties of the zirconium oxide thin films deposited onto SS304 substrates using the direct current (DC) magnetron sputtering technique.

Design/methodology/approach

DC sputtering at different powers – 80, 100 and 120 W – was used to deposit ZrO2 thin films onto different substrates (Si/SS304) without annealing of the substrate. Atomic force microscope (AFM), energy-dispersive X-ray spectroscopy (EDS), Tafel extrapolation and contact angle techniques were applied to investigate the surface roughness, chemical compositions, corrosion behavior and hydrophobicity of these films.

Findings

Results showed that the thickness of the deposited film increased with power increase, while the corrosion current decreased with power increase. AFM images indicated that the surface roughness decreased with an increase in DC power. EDS analysis showed that the thin film has a stoichiometric ZrO2 (Zr:O 1:2) composition with basic uniformity. Water contact angle measurements indicated that the hydrophobicity of the synthesized films decreased with an increase in surface roughness.

Originality/value

DC magnetron sputtering technique is infrequently used to deposition thin films. The obtained thin films showed good hydrophobic and anticorrosion properties. Finally, results are compared with other deposition techniques.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 5 March 2024

Bingchao Ren and Shuwen Mei

This paper constructs a tripartite evolutionary game model between the government, the core enterprises of film copyright export and imports and uses the system dynamics model to…

Abstract

Purpose

This paper constructs a tripartite evolutionary game model between the government, the core enterprises of film copyright export and imports and uses the system dynamics model to simulate and find the optimal selection results of single and mixed government incentives under dynamic changes, aiming to promote the development of foreign trade of film copyright and innovation and development of the film industry so as to improve the overall social benefits of the film industry and provide policy enlightenment for enhancing the import power of foreign core enterprises to introduce domestic film copyrights.

Design/methodology/approach

In this paper, a tripartite evolutionary game model of the government, the core enterprises of film copyright export and imports is constructed, the evolution process of cooperation strategy is derived, the impact of innovation income coefficient, mixed incentive policy and single incentive policy on the evolution results is analyzed, and the system dynamic model is used to simulate to find the optimal selection results of single and mixed government incentives under dynamic changes, so as to provide reference for the government’s dynamic incentive decision-making.

Findings

The results show that export-oriented core firms are more sensitive to mixed incentives, while import-oriented core firms respond more quickly to single incentives. The large innovation income coefficient has a negative impact on the willingness of import-oriented core enterprises to cooperate. The study proposes measures to increase the willingness of core companies to participate.

Research limitations/implications

Due to the fact that numerical simulation is based on simulation, there may be a certain gap between it and the actual situation. Therefore, it is necessary to further use actual data to conduct empirical analysis on the theoretical model.

Practical implications

This article mainly focuses on analyzing the impact of strategy choices and related parameters of various entities on the incentive mechanism and studying the foreign trade cooperation strategies of film copyright export enterprises under policy support from a theoretical model perspective. Furthermore, research has proven that in order to effectively enhance the willingness of foreign import core enterprises to participate in the foreign trade of domestic film copyrights, the government needs to coordinate the use of single incentive policies and mixed incentive policies. This study provides a major contribution for policymaker to develop film copyright import and export trade.

Social implications

Based on the research conclusions, this paper puts forward management countermeasures to further improve the development of the film copyright import and export trade. The first is to enrich government incentive methods and stimulate the vitality of film copyright and foreign trade market entities. The second is to guide the core enterprises of film copyright export to increase investment in innovation and stimulate the endogenous driving force of industrial development. Finally, lengthen the foreign trade industry chain of film copyright and increase the income of film derivatives.

Originality/value

Firstly, this paper applies the research methods of evolutionary game and system dynamics simulation to the field of foreign trade research on film copyright and expands the research perspectives and methods of the film industry. Secondly, by analyzing the “cost-benefit incentive” relationship of the evolutionary game of government export-oriented core enterprises and importing core enterprises, an evolutionary game model is constructed, the quantitative point of tripartite interest decision-making is solved and the research object of the evolutionary game method is expanded. Finally, the system dynamics model is used to simulate and find the optimal selection results of single and mixed government incentives under dynamic changes, so as to provide reference for the government’s dynamic incentive decision-making.

Details

Kybernetes, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0368-492X

Keywords

Article
Publication date: 16 January 2024

Mohamed Abd Alsamieh

In this study a numerical analysis of the elastohydrodynamic lubrication point contact problem in the unsteady state of reciprocating motion is presented. The effects of…

Abstract

Purpose

In this study a numerical analysis of the elastohydrodynamic lubrication point contact problem in the unsteady state of reciprocating motion is presented. The effects of frequency, stroke length and load on film thickness and pressure variation during one operating cycle are discussed. The general tribological behavior of elastohydrodynamic lubrication during reciprocating motion is explained.

Design/methodology/approach

The system of equations of Reynolds, film thickness considering surface deformation and load balance equations are solved using the Newton-Raphson technique with the Gauss-Seidel iteration method. Numerical solutions were performed with a sinusoidal contact surface velocity to simulate reciprocating elastohydrodynamics. The methodology is validated using historical experimental measurements/observations and numerical predictions from other researchers.

Findings

The numerical results showed that the change in oil film during a stroke is controlled by both wedge and squeeze effects. When the surface velocity is zero at the stroke end, the squeeze effect is most noticeable. As the frequency increases, the general trend of central and minimum film thickness increases. With the same entraining speed but different stroke lengths, the properties of the oil film differ from one another, with an increase in stroke length leading to a reduction in film thickness. Finally, the numerical results showed that the overall film thickness decreases with increasing load.

Originality/value

General tribological behaviors of elastohydrodynamic lubricating point contact, represented by pressure and film thickness variations over time and profiles, are analyzed under reciprocating motion during one working cycle to show the effects of frequency, stroke length and applied load.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 8 November 2023

Sanjna Sebastian Thoppil and Sanjay Pandy

This study explores the relevance of film texts in Indian social studies classrooms for students at the upper primary level. It examines how different types of visual texts can…

Abstract

Purpose

This study explores the relevance of film texts in Indian social studies classrooms for students at the upper primary level. It examines how different types of visual texts can facilitate awareness, critical thinking, discussion and action.

Design/methodology/approach

Using multimodal discourse analysis (MDA), this paper critically evaluates five selective films from regional cinemas in India and explores their teaching implications for social studies. The study argues that films are vital multimodal resources that can challenge the prevailing narratives in social studies pedagogy. It conveys how the suggestive revised taxonomy could benefit the students. It proposes a classification system for film analysis with discussion and states how films can bring out interrelated themes and encourage deeper, critical inquiry within the curriculum. The study finds discourse around the films and qualitatively stresses dialogue exchange with sentiment analysis using MAXQDA software. Developed by VERBI software, MAXQDA is a product whose name is inspired by the German Sociologist Max Weber, while the ‘QDA' stands for Qualitative Data Analysis.

Findings

The films act as multimodal texts, navigators, metaphors, communicative circuits and catalysts. The paper concludes that films can improve and expand multimodal learning of social studies in three ways: films help learners connect emotionally with the concepts, films make the learning process more appealing and extend it beyond classroom boundaries and films offer a unique insight into the socio-cultural subtleties that are often limited in textbooks.

Originality/value

This research pioneers an intersectionality-driven framework for film analysis in the curriculum for Indian upper primary social studies, offering innovative pedagogical tools to enrich Indian curriculum insights and bridge existing knowledge gaps.

Details

Social Studies Research and Practice, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1933-5415

Keywords

Article
Publication date: 6 November 2023

Huda Abdullah, Norshafadzila Mohammad Naim, Kok Seng Shum, Aidil Abdul Hamid, Mohd Hafiz Dzarfan Othman, Vidhya Selvanathan, Wing Fen Yap and Seri Mastura Mustaza

Regular monitoring of bacteria, especially Escherichia coli, in wastewater is crucial to ensure the maintenance of public health. Amperometric detection proves to be a fast…

Abstract

Purpose

Regular monitoring of bacteria, especially Escherichia coli, in wastewater is crucial to ensure the maintenance of public health. Amperometric detection proves to be a fast, sensitive and economically viable solution for E. coli enumeration. This paper reported a prototype amperometric sensor based on PANI-ZnO-NiO nanocomposite thin films prepared by sol–gel method and irradiated with gamma ray. The purpose of this study is to investigate the sensor performance of PANI-ZnO-NiO nanocomposite thin films to detect E. coli in water.

Design/methodology/approach

The films were varied with different compositions of ZnO and NiO by using the formula PANI-(ZnO)1-x-(NiO)x, with x = 0.2, 0.4, 0.6 and 0.8. PANI-ZnO-NiO nanocomposite thin films were characterized by using X-ray diffraction (XRD) and atomic force microscopy (AFM) to study the crystallinity and surface morphology of the films. The sensor performance was conducted using the current–voltage (I-V) measurement by testing the films in clean water and E. coli solution.

Findings

XRD diffractograms show the peaks of ZnO (1 0 0) and NiO (1 0 2). AFM analysis shows the surface roughness, and the grain size of PANI-ZnO-NiO thin films decreases when the concentration ratios of NiO increased. I-V curves show the difference in current flow, where the current in E. coli solution is higher than the clean water.

Originality/value

PANI-(ZnO)1-x-(NiO)x nanocomposite thin film with the highest concentration of ZnO performed the highest sensitivity among the other concentrations, which can be used to indicate the presence of E. coli bacteria in water.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 13 November 2023

Nada Wafa and Susan Lynn Douglass

The purpose of this paper is to engage readers with Unity Productions Foundation (UPF) films, which provide a powerful, inspirational digital tool for teachers. The organization's…

Abstract

Purpose

The purpose of this paper is to engage readers with Unity Productions Foundation (UPF) films, which provide a powerful, inspirational digital tool for teachers. The organization's mission is to create documentaries, films and educational materials that contribute to bringing to light compelling stories of Muslim engagement through history and culture. UPF films and educational projects aim to promote peace and understanding to increase cultural pluralism and counter bigotry in our world.

Design/methodology/approach

Teachers will be able to utilize the resources provided in this paper to harness the power of media in their classrooms. Outlining the process by which teachers can follow the C3 inquiry using the film Prince Among Slaves will prepare teachers to see the alignment of the C3 Framework with their teaching. The “best practice” classroom strategies in structuring deliberations are ones that encourage students to fully participate and emphasize their voice.

Findings

This paper will unpack the practice methods that address the film Prince Among Slaves to be of benefit when sharing narratives through digital film and engage students in critical thinking through the C3 Framework. UPF films are the product of scholarly research and innovative production teams as the films provide the opportunity to visualize and explore multiple perspectives to understand historical content by providing a context for inquiry teaching and learning that is inclusive through deliberative discussions in the classroom.

Originality/value

The author certifies that this manuscript submission is original work and that all authors were involved in the intellectual elaboration of the manuscript and all parties have been acknowledged.

Details

Social Studies Research and Practice, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1933-5415

Keywords

Article
Publication date: 23 November 2023

Donald R. McClure, Anne-Lise Halvorsen and Daniel J. Thomas III

This study explores the value of sports films for engaging youth in issues related to patriotism, justice, equity and liberty. The authors analyze how two sports films, 42 and…

Abstract

Purpose

This study explores the value of sports films for engaging youth in issues related to patriotism, justice, equity and liberty. The authors analyze how two sports films, 42 and Battle of the Sexes, have pedagogical potential and value in secondary social studies methods classes, as well as what criteria educators might use when selecting films (and television series) for classroom use.

Design/methodology/approach

Using content analysis, the authors respond to the following questions: (1) What critical themes related to civic education surface in the sports films 42 and Battle of the Sexes? and (2) What framework might guide the use of selecting sports films and sports film clips for educators' civic educational use?

Findings

Five themes surfaced in the films 42 and Battle of the Sexes: economics as a force for social change; racism and anti-Blackness, athletes as more than athletes, resisting oppression, and sexism and homophobia. Instruction related to these themes has the potential to engage students in critical, awareness-based approaches to civic education.

Originality/value

Sports films show promise for engaging youth due to their interests in the medium of film and in sports, both as participants and spectators. Across the world, athletes face questions and issues related to patriotism, justice, equity and liberty on courts, fields, tracks and rinks, These questions and issues are deeply embedded in civic education. This study is among the first of its kind to explore the pedagogical potential of sports films.

Details

Social Studies Research and Practice, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1933-5415

Keywords

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