A Study of the Friction and Wear of Cartridge and Free-Cutting Brass

1983 ◽  
Vol 105 (1) ◽  
pp. 31-35 ◽  
Author(s):  
R. Glardon ◽  
I. Finnie
Keyword(s):  
Friction And Wear ◽  
Deformation Characteristics ◽  
Subsurface Layers ◽  
Quantitative Results

Friction and wear experiments on brasses with and without lead particles are presented and compared. Quantitative results are given for the dimensions of the wear tracks and of the subsurface layers. Differences in the behavior of the two alloys are treated in terms of deformation characteristics and microstructure and the role of a dispersion of lead particles on friction and wear is discussed.

A Comparative Investigation of the Sliding Wear of Some FCC Metals

1983 ◽  
Vol 105 (1) ◽  
pp. 36-41 ◽  
Author(s):  
R. Glardon ◽  
I. Finnie
Keyword(s):  
Sliding Wear ◽  
Friction And Wear ◽  
Copper Alloys ◽  
Comparative Investigation ◽  
Experimental Investigations ◽  
Future Research ◽  
Subsurface Layers ◽  
Areas Of Interest ◽  
Cyclic Plastic Deformation

Experimental investigations of the friction and wear of four copper alloys and pure nickel are presented. Measurements of the shape and dimensions of the wear tracks and of the extent of subsurface layers are also reported. The results are discussed in terms of mechanical behavior and possible correlations with conventional mechanical properties are considered. The role of cyclic plastic deformation is emphasized and areas of interest for future research are suggested.

scholarly journals Power, the Pacific Islands, and the Prestige Press: A Case Study of How Climate Reporting is Influenced by UN Framework Convention on Climate Change Summits

2021 ◽  
pp. 194016122110180
Author(s):  
Meghan M. Shea ◽  
James Painter ◽  
Shannon Osaka
Keyword(s):  
Climate Change ◽  
Media Coverage ◽  
Pacific Islands ◽  
Structured Interviews ◽  
The Pacific ◽  
Emotional Appeals ◽  
Issue Attention ◽  
Quantitative Results

While studies have investigated UN Framework Convention on Climate Change (UNFCCC) meetings as drivers of climate change reporting as well as the geopolitical role of Pacific Islands in these international forums, little research examines the intersection: how media coverage of Pacific Islands and climate change (PICC) may be influenced by, or may influence, UNFCCC meetings. We analyze two decades of reporting on PICC in American, British, and Australian newspapers—looking at both volume and content of coverage—and expand the quantitative results with semi-structured interviews with journalists and Pacific stakeholders. Issue attention on PICC increases and the content changes significantly in the periods around UNFCCC meetings, with shifts from language about vulnerability outside of UNFCCC periods to language about agency and solutions. We explore the implications of these differences in coverage for both agenda setting and the amplification of emotional appeals in UNFCCC contexts.

The role of surface topography and normal load in the initiation of ratchetting-peak friction, seizure, scuffing, and elastic shakedown

2021 ◽  
pp. 1-12
Author(s):  
Vimal Edachery ◽  
V. Swamybabu ◽  
Gurupatham Anand ◽  
Paramasamy Manikandan ◽  
Satish V. Kailas
Keyword(s):  
Steady State ◽  
Surface Topography ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Critical Parameter ◽  
Normal Load ◽  
Sliding Direction ◽  
Elastic Shakedown ◽  
Lubrication Conditions

Abstract Surface topography is a critical parameter that can influence friction and wear in engineering applications. In this work, the influence of surface topography directionality on seizure and scuffing initiation during tribological interactions is explored. For this, unidirectional sliding wear experiments were carried out in immersed lubrication conditions for various normal loads. The tribological interactions were studied using EN31-60 HRC flats and SAE52100-60HRC pins in a sphere on flat configuration. The results show that, in some cases, the sliding interactions in the initial cycles lead to a high friction coefficient of up to ∼0.68 in lubricated conditions, which was termed as ‘peak friction’, and this was accompanied by scuffing. The existence of peak friction was found to be dependent on surface topography directionality, especially when the directionality in topography was parallel to the sliding direction. Continuous ratchetting was found to be the cause of peak friction which was accompanied by seizure and scuffing. When the topography directionality was perpendicular or independent of sliding direction, elastic shakedown occurred at earlier cycles and prevented peak friction initiation, scuffing and also facilitated for higher steady-state friction values.

scholarly journals Research on the Re-Deformation Characteristics of Hot Stamping of Boron Steel Parts with Tailored Properties

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1136 ◽  
Author(s):  
Ling Kong ◽  
Yan Peng ◽  
Caiyi Liu
Keyword(s):  
Grain Boundaries ◽  
Initial Phase ◽  
Hot Stamping ◽  
High Strength ◽  
Boron Steel ◽  
Deformation Characteristics ◽  
Maximum Strain ◽  
Soft Zone ◽  
Local Misorientation

Traditional hot-stamping products have super-high strength, but their plasticity is usually low and their integrated mechanical properties are not excellent. Functionally graded property structures, a relatively novel configuration with a higher material utilization rate, have increasingly captured the attention of researchers. Hot stamping parts with tailored properties display the characteristics of local high strength and high plasticity, which can make up for the limitations of conventional hot stamping and optimize the crash safety performance of vehicles. This new idea provides a means of personalized control in the hot-stamping process. In this paper, a new strategy of local induction heating and press hardening was used for the hot stamping of boron steel parts with tailored properties, of which the microstructure from the hard zone to the soft zone shows a gradient distribution consisting of a martensite phase, multiphase and initial phase, with the hardness ranging from 550 HV to 180 HV. The re-deformation characteristics of hot stamping parts with tailored properties have been studied through the uniaxial tensile test, in cooperation with digital image correlation (DIC) and electron backscattered diffraction (EBSD) techniques. The experiments show that there are easily observable strain distribution characteristics in the re-deformation of hot stamping parts with tailored properties. In the process of tensile deformation, the initial phase zone takes the role of deformation and energy absorption, with the maximum strain before necking reaching 0.32. The local misorientation of this zone was high, and a large number of low angle grain boundaries were formed, while the proportion of small angle grain boundaries increased from 13.5% to 63.3%, and the average grain size decreased from 8.15 μm to 3.43 μm. Meanwhile, the martensite zone takes on the role of anti-collision protection, with a maximum strain of only 0.006, and its local misorientation is mostly unchanged. The re-deformation experimental results show that the hot stamping of boron steel parts with tailored properties meets the functional requirements of a hard zone for anti-collision and a soft zone for energy absorption, suitable for automobile safety parts.

The role of N transformations in the formation of acidic subsurface layers in stock urine patches

Soil Research ◽  
2004 ◽  
Vol 42 (2) ◽  
pp. 221 ◽  
Author(s):  
J. R. Condon ◽  
A. S. Black ◽  
M. K. Conyers
Keyword(s):  
Soil Surface ◽  
Urea Hydrolysis ◽  
Balance Model ◽  
Urea Solution ◽  
Nitrogen Transformations ◽  
N Transformations ◽  
Soil Layers ◽  
Subsurface Layers ◽  
Dominant Process

This study examines the role of nitrogen transformations in the acidification of soil under stock urine patches, specifically the formation of acidic subsurface layers. These are horizontal planes of acidity several centimetres below the soil surface. Glasshouse studies were conducted to relate nitrogen transformations to measured pH changes in soil treated with urine or urea solution (simulated urine). Acidic subsurface layers formed in both urine- and simulated urine-treated soil. With the development of a H+ balance model, the contribution of nitrogen transformations to changes in the H+ concentrations in simulated urine patches was determined.During the first 9 days following treatment, urea hydrolysis and NH3 volatilisation dominated changes in H+ concentration. After that, net immobilisation contributed to H+ changes; however, nitrification was the dominant process occurring. Downward movement of NH4+ originating from urea hydrolysis allowed more nitrification to occur in lower soil layers. The net result of these processes was net acidification of the 4–6, 6–8, and 8–10 cm layers by approximately 0.7, 0.6, and 0.3 pH units, respectively. Thus nitrogen transformations were responsible for the formation of acidic subsurface layers in simulated stock urine patches within 6 weeks of application.

The Role of Oxide Tribofilms on Friction and Wear of Different Thermally Sprayed WC-CoCr

2017 ◽  
Vol 26 (3) ◽  
pp. 492-502 ◽  
Author(s):  
J. A. R. Wesmann ◽  
S. Kuroda ◽  
N. Espallargas
Keyword(s):  
Friction And Wear ◽  
Thermally Sprayed

scholarly journals Cloud Computing Platform for Mentoring Trainees: The Case of the Professional Training of Midwives in Morocco

2021 ◽  
pp. 59-67
Author(s):  
Imad Lamniai ◽  
Mustapha Bassiri ◽  
Abderrazak Mazouak ◽  
Said Belaaouad ◽  
Malika Tridane
Keyword(s):  
Cloud Computing ◽  
Professional Training ◽  
Training Institution ◽  
Pedagogical Innovation ◽  
Electronic Learning ◽  
Computing Platform ◽  
Quantitative Results ◽  
Technological Integration

The digital transformation invites several solutions to optimize professional training. Its particularity lies in the management, conservation and securing of their data to each of the players. The use of the electronic learning booklet with Cloud computing aims to be simple and intuitive, it creates interaction and makes it possible to strengthen the links of the trinomial (Student, Educational tutor, supervisor on a training)We thought of using a online platform tool using Cloud Computing Technology to overcome the limitations of the "paper" learning booklet. This technical-pedagogical system makes it possible to save all data of the apprentice through evaluation grids and follow-up sheets, both during training periods and in theoretical training, according to periods decided by the training institution. The adoption of this imperative of qualification and technological integration retains the role of each of the actors: the student, the pedagogical supervisor and the supervisor on a training course. In this strategic vision, we have conceptualized and implemented an Electronic Learning Booklet (ELB) for integrative professionalization.Our Research Methodology is based on an engineering of the training devices. Initially we will present the context of the research project ELB. In this framework, we will present our problematic centered on the management of technical invention and pedagogical innovation in the framework of training of Midwives in Morocco. In a second step, we will discuss the qualitative and quantitative results of the statistical analysis of our target sample.By crossing the results of the study with the validation interviews, which confound and invalidate our starting hypothesis. LEA is a powerful vector of quality and academic performance of midwifery training.

scholarly journals The Role of Borrowers Living Area and Its Moderation Effect of Relationship of Microfinance and Poverty Alleviation in Sri Lanka: Multi –Group CFA

2019 ◽  
pp. 1-8
Author(s):  
J.A Prasansha Kumari ◽  
Dr. S.M. Ferdous Azam ◽  
Prof. Siti Khalidah
Keyword(s):  
Poverty Alleviation ◽  
Moderating Effect ◽  
Moderation Effect ◽  
Affected Area ◽  
Quantitative Results ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship ◽  
Living Area

This article highlights the moderating effect of living areas of the borrowers on the impact of microfinance programs on poverty alleviation. The study has utilized the data from 497 borrowers of Samurdhi microfinance in five disaster-affected districts in the country to examines that two different living areas (disaster-affected and non-disaster affected area) of borrowers moderate the relationship between microfinance services and poverty alleviation. The Multi- Group CFA analysis was performed to identify the moderating effect using AMOS 21. Quantitative results were finding revealed that the moderation tests were significant for all the three microfinance services on poverty alleviation. The effect of microfinance services of borrowers in the disaster-affected area higher than the borrowers in non-disaster area.

scholarly journals The Role of Responsive Leadership in Meeting Customers' Needs during Crises

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Large Scale ◽  
Education Institution ◽  
Face To Face ◽  
Leadership Attributes ◽  
Leadership Support ◽  
The Face ◽  
Quantitative Results ◽  
The Impact

This case study conducted to investigate the impact of a responsive leadership approach in meeting customers' needs in a higher education institution in the UAE during the COVID-19 pandemic. For this purpose, a mixed-method model has been used. The data has been collected from a convenient sample working and studying at Al Qasimia University Language Center, in fall 2020. This result indicates that the provided responsive leadership support during COVID-19 was effective and helped in motivating learners and customers to keep learning and making progress greater than what was shown before COVID-19, during the face-to-face teaching and physical assessment. Although the qualitative and quantitative results in this case study revealed a significant impact of responsive leadership approach on customers’ progress, there is still a need to conduct other researches to develop and validate a responsive leadership inventory to facilitate measuring of responsive leadership attributes in a large scale sample and/or population.

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