MECHANICAL AND TRIBOLOGICAL ANALYSIS OF MONOLITH AND COATING POLYETHERETHERKETONE

Tribologia ◽  
2019 ◽  
Vol 286 (4) ◽  
pp. 73-86
Author(s):  
Mateusz OTTO ◽  
Sławomir ZIMOWSKI ◽  
Wojciech SIKORA ◽  
Tomasz MOSKALEWICZ
Keyword(s):  
Tribological Properties ◽  
Vickers Hardness ◽  
Research Work ◽  
Scratch Hardness ◽  
The Coefficient Of Friction ◽  
Substrate Properties ◽  
Mar Resistance ◽  
Result Analysis ◽  
Scratch Tests ◽  
The Impact

In this work, a comparative analysis of the micromechanical and tribological properties of polyetheretherketone (PEEK) in bulk and coating form was performed. The PEEK 708 coating was applied on a Ti6Al4V titanium alloy flat specimen using the electrophoretic deposition method. The micromechanical properties were determined through indentation tests performed using the Vickers method and scratch tests. Based on research work, the Vickers hardness (HV), elastic modulus (E), scratch hardness (HS), and Micro Mar Resistance (MMR) were determined. The tribological properties were defined by the coefficient of friction (fs and fw), which was obtained in scratch tests and ball-on-disk tests. The results of this research indicate, despite the slightly higher Vickers hardness (HV) of the PEEK 708 coating (HV=350 MPa, HS=300 MPa) relative to PEEK bulk (HV=300 MPa, HS=210 MPa), that there is an almost 40% difference between the scratch hardness (HS) values of these PEEK forms. It appears from the result analysis in this paper that testing methods to determine the micromechanical and tribological properties of PEEK in monolith form can be used for both PEEK coatings. Under certain test conditions, the impact of the substrate properties on the results of the PEEK 708 coating was not found.

Mechanical and Tribological Properties of Phenol Formaldehyde Resin Reinforced with Nano-Silica

2011 ◽  
Vol 194-196 ◽  
pp. 1772-1775 ◽  
Author(s):  
Chuan Bai Yu ◽  
Chun Wei
Keyword(s):  
Tribological Properties ◽  
Phenol Formaldehyde ◽  
Flexural Modulus ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Reinforced Composites ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction ◽  
The Impact ◽  
Worn Surface

Reinforced phenol formaldehyde resin (PF) matrix nanocomposites with different nano-SiO2 were fabricated with two-roll compounding and compression molding technology. The mechanical and tribological behaviors of the reinforced composites were studied. The friction and wear experiments were tested on a constant speed machine (D-SM). The impact and flexural strength of nanocomposites were increased by the addition of various types of SiO2, but the flexural modulus was decreased. The effects of the addition of various types of SiO2 on tribological properties of the composites were explored in this study. The results showed that the coefficient of friction of the composites increased, while the wear rate values decreased at various temperatures. Microstructure of worn surface of the tested composites was observed by scanning electronic microscope (SEM) and the wear mechanism of the reinforced composites was studied.

THE EFFECT OF MeC NANOPARTICLES ON THE MICROMECHANICAL AND TRIBOLOGICAL PROPERTIES OF CARBON COMPOSITE COATINGS

Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 157-163
Author(s):  
Sławomir ZIMOWSKI ◽  
Marcin KOT ◽  
Tomasz MOSKALEWICZ
Keyword(s):  
Wear Resistance ◽  
Amorphous Carbon ◽  
Tribological Properties ◽  
Composite Coatings ◽  
Carbon Matrix ◽  
Carbon Composite ◽  
Nanocrystalline Phase ◽  
Strong Adhesion ◽  
Scratch Tests ◽  
The Impact

Nanocomposite carbon coatings composed of a nanocrystalline phase and an amorphous carbon matrix (a-C or a-C:H) are an important group of coatings for tribological applications, especially if low friction is desired. Strong adhesion between the coating and the substrate as well as the ability to carry load are particularly important in ensuring the durability of the system. In this paper, the impact of a reinforcing phase in the form of hard carbides of chromium, titanium and tungsten (MeC) on the micromechanical and tribological properties of MeC/a-C coatings were analysed. The microhardness and modulus of elasticity using the indentation method and adhesion of these coatings to the substrate in scratch tests were determined. On the basis of tribological tests, the friction coefficient and wear rate of the coatings were determined during nonlubricated sliding contact with an alumina ball. The tested nanocomposite coatings showed very good sliding properties and wear resistance. The nc-WC/a-C and nc-TiC/a-C coatings exhibit the smallest coefficient of friction (below 0.1) and the highest wear resistance. The presence of nanocrystalline carbides in the amorphous carbon matrix limits the propagation of cracks in the coatings and allows the higher load carrying capacity.

Piezoelectric β-polymorph formation of new textiles by surface modification with coating process based on interfacial interaction on the conformational variation of poly (vinylidene fluoride) (PVDF) chains

2020 ◽  
Vol 91 (3) ◽  
pp. 31301
Author(s):  
Nabil Chakhchaoui ◽  
Rida Farhan ◽  
Meriem Boutaldat ◽  
Marwane Rouway ◽  
Adil Eddiai ◽  
...  
Keyword(s):  
High Efficiency ◽  
Vinylidene Fluoride ◽  
Research Work ◽  
Research Area ◽  
Interfacial Interaction ◽  
Tetraethyl Orthosilicate ◽  
Poly Vinylidene Fluoride ◽  
Carbon Nanofillers ◽  
The Impact ◽  
Advanced Applications

Novel textiles have received a lot of attention from researchers in the last decade due to some of their unique features. The introduction of intelligent materials into textile structures offers an opportunity to develop multifunctional textiles, such as sensing, reacting, conducting electricity and performing energy conversion operations. In this research work nanocomposite-based highly piezoelectric and electroactive β-phase new textile has been developed using the pad-dry-cure method. The deposition of poly (vinylidene fluoride) (PVDF) − carbon nanofillers (CNF) − tetraethyl orthosilicate (TEOS), Si(OCH2CH3)4 was acquired on a treated textile substrate using coating technique followed by evaporation to transform the passive (non-functional) textile into a dynamic textile with an enhanced piezoelectric β-phase. The aim of the study is the investigation of the impact the coating of textile via piezoelectric nanocomposites based PVDF-CNF (by optimizing piezoelectric crystalline phase). The chemical composition of CT/PVDF-CNC-TEOS textile was detected by qualitative elemental analysis (SEM/EDX). The added of 0.5% of CNF during the process provides material textiles with a piezoelectric β-phase of up to 50% has been measured by FTIR experiments. These results indicated that CNF has high efficiency in transforming the phase α introduced in the unloaded PVDF, to the β-phase in the case of nanocomposites. Consequently, this fabricated new textile exhibits glorious piezoelectric β-phase even with relatively low coating content of PVDF-CNF-TEOS. The study demonstrates that the pad-dry-cure method can potentially be used for the development of piezoelectric nanocomposite-coated wearable new textiles for sensors and energy harvesting applications. We believe that our study may inspire the research area for future advanced applications.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Serving the People in Long Beach, California: Advancing Justice for Southeast Asian Youth through Community University Research Partnerships

2019 ◽  
Vol 16 (1-2) ◽  
pp. 1-34
Author(s):  
R. Varisa Patraporn
Keyword(s):  
Asian American ◽  
Research Work ◽  
Community Based Participatory Research ◽  
Youth Empowerment ◽  
Long Beach ◽  
Structured Interviews ◽  
Research Partnerships ◽  
Community Needs ◽  
The People ◽  
The Impact

Khmer Girl’s in Action is a nonprofit that successfully utilizes community-based participatory research (CBPR) with university partners to create social change for youth in Long Beach, CA. Based on semi-structured interviews and content analysis of news articles, I explore the impact and sustainability of this research work and the research partnerships. Findings highlight impacts such as youth empowerment, heightened awareness around community needs, policy change, and CBPR curriculum improvements in the field as impacts. Sustainability requires integrating research into program funding, utilizing a tailored training curriculum, building on community members prior relationships, and selecting partners that share common goals, levels of commitment, and flexibility. As funders demand more data to justify community needs, understanding more examples of such work in the Asian American community will be useful for informing future partnerships.

Impacto de las tecnologías de la información y las comunicaciones: Una mirada en la Educación Superior

2017 ◽  
Vol 1 (6) ◽  
Author(s):  
Karina Virginia Mero Suárez ◽  
Edwin Joao Merchán Carreño ◽  
Ana Del Rocío Fernández Torres ◽  
Narcisa María Crespo Torres
Keyword(s):  
Higher Education ◽  
Information Technology ◽  
Research Work ◽  
Field Research ◽  
Research Problem ◽  
Research Report ◽  
Educación Superior ◽  
Educational Design ◽  
Educacion Superior ◽  
The Impact

El artículo aborda la necesidad de la creatividad que se impone en la era actual del conocimiento y la importancia que  constituyen las tecnologías como herramientas indispensables en todas las esferas de la vida. En Trabajo toma como campo investigativo los cambios que se llevan a cabo en esta esfera en la Universidad Estatal del Sur de Manabí y la Universidad Técnica de Babahoyo, Ecuador, donde se toman como objeto el proceso de enseñanza aprendizaje en la Educación Superior. El objetivo de la investigación fue comunicar el impacto de las Tecnologías de la Información y las Comunicaciones en las Universidades, donde se hace énfasis en el nuevo rol de los docentes y su nuevo desempeño de facilitadores del aprendizaje en los educandos a través en los nuevos escenarios mediados por las tecnologías. Para el desarrollo exitoso de esta memoria investigativa se   usó como metodología instrumentos que se basaron fundamentalmente en documentos referativos que ayudaron a justificar el problema de investigación, el cual consistía fundamentalmente en el impacto de las nuevos  dispositivos tecnológicos y su utilidad en los centros de altos estudios del país. Se concluyó que las Tecnologías de la Información y Comunicación son herramientas indispensables en la docencia y al mismo tiempo la forma de intervenir en el diseño educativo que nos llevan a explorar nuevos métodos docentes en los escenarios educativos mediados por estas. Se constató además que estas herramientas favorecen satisfactoriamente al proceso si se tiene una buena preparación por parte del docente.   Palabras clave: Herramientas tecnológicas, universidades, formación, docencia universitaria, proceso de enseñanza – aprendizaje Impact of information technology and communications: a look at higher education  Abstract The article states the need of the creativity that prevails in the current era of knowledge and the importance that technologies constitute in all spheres of life. In field research work it takes as changes take place in this area in Southern State University of Manabí and the Technical University of Babahoyo, Ecuador, where they are taken as an object the process of learning in higher education. The aim of the research was to communicate the impact of Information Technology and Communications in the universities, where the emphasis is on the new role of teachers and their new performance of facilitators of learning in students through the new scenarios mediated by technologies. For the successful development of this research report it was used as a methodology instruments based mainly on referative documents that helped to justify the research problem, which consisted mainly of the impact of new technological devices and their use in the centers of higher learning in the country. It was concluded that information technology and communication are indispensable tools in teaching and at the same time how to intervene in the educational design that lead us to explore new teaching methods in educational settings mediated by these. It was further found that these tools successfully promote the process if there is a good preparation by the teacher.

An Energy Efficient Spectrum Aware Routing for Cognitive Radio Networks (CRNs)

2020 ◽  
Vol 10 ◽  
Author(s):  
Dileep Reddy Bolla ◽  
Jijesh J J ◽  
Mahaveer Penna ◽  
Shiva Shankar
Keyword(s):  
Cognitive Radio ◽  
Spectrum Sensing ◽  
Cognitive Radio Networks ◽  
Energy Efficient ◽  
Research Work ◽  
Spectrum Management ◽  
Residual Energy ◽  
Radio Networks ◽  
Traffic Load ◽  
The Impact

Back Ground/ Aims:: Now-a-days in the Wireless Communications some of the spectrum bands are underutilized or unutilized; the spectrum can be utilized properly by using the Cognitive Radio Techniques using the Spectrum Sensing mechanisms. Objectives:: The prime objective of the research work carried out is to achieve the energy efficiency and to use the spectrum effectively by using the spectrum management concept and achieve better throughput, end to end delay etc., Methods:: The detection of the spectrum hole plays a vital role in the routing of Cognitive Radio Networks (CRNs). While detecting the spectrum holes and the routing, sensing is impacted by the hidden node issues and exposed node issues. The impact of sensing is improved by incorporating the Cooperative Spectrum Sensing (CSS) techniques. Along with these issues the spectrum resources changes time to time in the routing. Results:: All the issues are addressed with An Energy Efficient Spectrum aware Routing (EESR) protocol which improves the timeslot and the routing schemes. The overall network life time is improved with the aid of residual energy concepts and the overall network performance is improved. Conclusion:: The proposed protocol (EESR) is an integrated system with spectrum management and the routing is successfully established to communication in the network and further traffic load is observed to be balanced in the protocol based on the residual energy in a node and further it improves the Network Lifetime of the Overall Network and the Individual CR user, along with this the performance of the proposed protocol outperforms the conventional state of art routing protocols.

Impact of Chatbot in Transforming the Face of Retailing- An Empirical Model of Antecedents and Outcomes

2019 ◽  
Vol 12 ◽  
Author(s):  
Kumari Anshu ◽  
Loveleen Gaur ◽  
Arun Solanki
Keyword(s):  
Research Work ◽  
Shopping Behavior ◽  
Model Framework ◽  
Shopping Experience ◽  
The Face ◽  
Strongly Agree ◽  
Different Characteristics ◽  
Work Done ◽  
The Impact ◽  
Self Administered Questionnaire

Chatbot has emerged as a significant resolution to the swiftly growing customer caredemands in recent times. Chatbot has emerged as one of the biggest technological disruption. Simply speaking, it is a software agent facilitating interaction between computers and humans in natural language. So basically, it is a simulated, intellectual dialogue agent functional in a range of consumer engagement circumstances. It is the easiest and simplest means enable interaction between the retailers and the customers. </p><p> • Purpose- Most of the research work done in this field is concerned with their technical aspects. The recent research on chatbot pay little attention to the impact it is creating on users’ experience. Through this work, author is making an effort to know the customer-oriented impact that the chatbot bear on the shoppers. The purpose of this study is to develop and empirically test a framework that identify the customer oriented attributes of chatbot and impact of these attributes on customers. </p><p> • Objectives- The study intends to bridge the gap between concepts and actual attributes and applications on the subject of Chatbot. The following research objectives can address the various aspects of Chatbot affecting the different characteristics of consumers shopping behaviors: a) Identify the various attributes of chatbot that bears an impression on consumer shopping behavior. b) Evaluate the impact of chatbot on consumer shopping behavior that leads to the development of chatbot usage and adoption among the customer. </p><p> • Design/Methodology/Approach – For the purpose of analysis, author has administered Factor analysis and Multiple regression using SPSS version 23 for identification of various attributes of Chatbot and knowing their impact on shoppers. A self-administered questionnaire from the review of literature is developed. Industry experts in the field of retailing and academician evaluate the questionnaire. Primary information from the respondents is gathered using this questionnaire. The questionnaire comprises of Likert scale on a scale of 1 to 5 where 1 stands for strongly disagree and 5 stands for strongly agree. Data is collected from 126 respondents, out of which 111 respondents were finally considered for study and analysis purpose. </p><p> • Findings – The empirical results show that the study identifies various attributes of chatbot like Trust, Usefulness, Satisfaction, Readiness to Use and Accessibility. It is also found that chatbot is really influencing the customers in providing them with shopping experience, which can be very helpful to the businesses for increasing the sales and creating repurchase intention among the customers. </p><p> • Originality/value – The recent research on chatbot pay little attention to the impact it is creating on customers who are actually interacting with it on regular basis. The research paper extends information for understanding and appreciating the customer oriented attributes of artificially intelligent Chatbot. In this regard, the author has developed a model framework and proposed the attributes identified. Through the work, author is also making an effort to test empirically the impact of the identified attributes on the shoppers.

The Impact of using 3D Interactive Animation Tool in Teaching Computer Programming at the Senior High School Level

2018 ◽  
Vol 3 (2) ◽  
pp. 18-28
Author(s):  
Najim Ussiph ◽  
Hamidu Kwame Seidu
Keyword(s):  
High School ◽  
Research Work ◽  
Instructional Method ◽  
Senior High School ◽  
School Level ◽  
Eastern Region ◽  
3D Animation ◽  
High School Level ◽  
Significant Difference ◽  
The Impact

A quasi experiment with interview was adopted to study the aptness of using 3D animations as an instructional method to introduce programming concepts to students at the Senior High School level. This research work was conducted with 100 students of Akroso Senior High School in the Birim central municipality of the eastern region of Ghana who were generally programming novice. Programming concepts considered included programming environments, loops, functions sequential and conditional execution of programs. A paired t-test carried out on the results of the performance test presents a p-value of 0.008 indicative of a numerically significant difference between the mean marks of participants during the experiments that used 3D animation method as against the experiments that used the text base method. Results from the interview showed that the instructional method used had impact on the performance of the learners. The use of 3D animation method presented programming concepts in a form that the learners can understand, motivates them to pursue programming related courses at a higher level and also impacts positively on their performance.

scholarly journals Risk of Increased Acceptance for Organizational Nepotism and Cronyism during the COVID-19 Pandemic

Risks ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 59
Author(s):  
Grzegorz Ignatowski ◽  
Łukasz Sułkowski ◽  
Bartłomiej Stopczyński
Keyword(s):  
Qualitative Study ◽  
Quantitative Methods ◽  
Research Work ◽  
Negative Effects ◽  
Qualitative And Quantitative ◽  
Qualitative And Quantitative Methods ◽  
Work Related ◽  
Social And Economic Development ◽  
The Times ◽  
The Impact

Nepotism and cronyism are forms of favoritism towards certain people in the workplace. For this reason, they constitute a problem for organization managers, ethicists and psychologists. Identifying the impact of COVID-19 pandemic on the increase of nepotism and cronyism may provide a basis for organizations to assess their extent and to take possible measures to prevent their negative effects. At the same time, the research presented in the article may provide a basis for further research work related to nepotism and cronyism at the times of other threats, different from the pandemic. The aim of the article is to examine the impact of the COVID-19 pandemic on growing acceptance for nepotism and cronyism in Polish enterprises. Qualitative and quantitative methods have been included in the conducted research. Qualitative study aimed at improving knowledge of nepotism and cronyism and the impact of the COVID-19 pandemic on these phenomena, followed by a quantitative study conducted in order to verify the information obtained in the qualitative study. This research has demonstrated that Nepotism and cronyism in the workplace, are phenomenon that are basically evaluated negatively. They adversely influences social and economic development, but the impact of COVID-19 pandemic on nepotism and cronyism is not significant.

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