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1 – 10 of 48Panagiota Polydoropoulou, Christos Vasilios Katsiropoulos, Andreas Loukopoulos and Spiros Pantelakis
Over the last decades, self-healing materials based on polymers are attracting increasing interest due to their potential for detecting and “autonomically” healing damage. The use…
Abstract
Purpose
Over the last decades, self-healing materials based on polymers are attracting increasing interest due to their potential for detecting and “autonomically” healing damage. The use of embedded self-healing microcapsules represents one of the most popular self-healing concepts. Yet, extensive investigations are still needed to convince on the efficiency of the above concept. The paper aims to discuss these issues.
Design/methodology/approach
In the present work, the effect of embedded self-healing microcapsules on the ILSS behavior of carbon fiber reinforced composite materials has been studied. Moreover, the self-healing efficiency has been assessed. The results of the mechanical tests were discussed supported by scanning electron microscope (SEM) as well as by Attenuated Total Reflection–Fourier-transform infrared spectroscopy (ATR–FTIR) analyses.
Findings
The results indicate a general trend of a degraded mechanical behavior of the enhanced materials, as the microcapsules exhibit a non-uniform dispersion and form agglomerations which act as internal defects. A remarkable value of the self-healing efficiency has been found for materials with limited damage, e.g. matrix micro-cracks. However, for significant damage, in terms of large matrix cracks and delaminations as well as fiber breakages, the self-healing efficiency is limited.
Originality/value
The results obtained by SEM analysis as well as by ATR–FTIR spectroscopy constitute a strong indication that the self-healing mechanism has been activated. However, further investigation should be conducted in order to provide definite evidence.
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Mohammad Sohail Haider and Chen Ya
Information literacy skills (ILSs) and information-seeking behavior (ISB) is a widespread topic that needs modern technologies to improve the technical skills of the students. The…
Abstract
Purpose
Information literacy skills (ILSs) and information-seeking behavior (ISB) is a widespread topic that needs modern technologies to improve the technical skills of the students. The purpose of this study is to assess the usage of library resources for medical college students. To explore and understand the student’s level of satisfaction, learning and seeking behavior by efficient information retrieval systems.
Design/methodology/approach
The study is based on a quantitative research method and data was collected from the undergraduate students of medical colleges Islamabad Pakistan. The data were analyzed by Statistical Package for Social Science (SPSS) version 25 using Pearson correlation statistical test to identify the level of proficiency of correlation of variables and testing of the proposed hypothesis.
Findings
The finding of the study shows that the medical students can enhance their IT skills to seek the information in this technology era. The medical institutional administration can develop the education development policy, traditional health education policy, funds allocating policy, health information literacy and collaborate with library staff for enhancing the services and to meet the information need of medical students.
Practical implications
The conclusion of this study is very helpful to reduce the barriers between the students and the library staff. The findings of the study are also beneficial for the administration to improve and develop the strategies for enhancing the ILSs of medical students to achieve medical educational information in the age of technology. Therefore, all significant structures want to improve and to develop the environment of information seeking by medical students to achieve medical educational information.
Social implications
Medical college library administrative management must be design useful a durable policy to come up with the technology development for digital literacy. The study reduces the barriers between the students and the library staff.
Originality/value
The study is based on quantitative research method to find out ISB of medical students.
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G. Mishra, S.R. Mohapatra, P.R. Behera, B. Dash, U.K. Mohanty and B.C. Ray
The main objective of this experimental investigation is to assess the effect of thermal and cryogenic treatment on hygrothermally conditioned glass fibre reinforced epoxy matrix…
Abstract
Purpose
The main objective of this experimental investigation is to assess the effect of thermal and cryogenic treatment on hygrothermally conditioned glass fibre reinforced epoxy matrix composites, and the impact on its mechanical properties with change in percentage of individual constituents of the laminates.
Design/methodology/approach
The present investigation is an attempt at evaluating the performance of the laminates subjected to different thermal and cryogenic treatments for varying time with prior hygrothermal treatment. The variability of hygrothermal exposure is in the range of 4‐64 h. Glass fibre reinforced plastics laminates with different weight fractions 0.50‐0.60 of fibre reenforcements were used. The ILSS, which is a matrix dominated was studied by three‐point bend test using INSTRON 1195 material testing machine.
Findings
The post‐hygrothermal treatments (both thermal and cryogenic exposures) resulted in an increase in the rate of desorption of moisture. It is noted that the hygrothermal treatment prior to the exposure to thermal or cryogenic conditioning is the major attribute to the variations in the ILSS values. The extent of demoisturisation of the hygrothermally conditioned composites due to a thermal or a cryogenic exposure is observed to be inversely related to its ILSS, independent of the fibre‐weight fractions. Also the ILSS is inversely related to the fibre‐weight fraction irrespective of the post‐hydrothermal treatment.
Originality/value
The reported data are based on experimental investigations.
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Jia Zhang, Chunlu Liu, Mark Luther, Brian Chil, Jilong Zhao and Changan Liu
Physical environments, especially the sound environments of ILSs on a university campus, have become increasingly important in satisfying the diverse needs of students. Poor sound…
Abstract
Purpose
Physical environments, especially the sound environments of ILSs on a university campus, have become increasingly important in satisfying the diverse needs of students. Poor sound environments are widely acknowledged to lead to inefficient and underutilised spaces and to negatively influence students' learning outcomes. This study proposes two hypotheses to explore whether students' sound environment perceptions are related to their individual characteristics and whether students' preferences for the type of ILS are related to their sound environment sensitivities.
Design/methodology/approach
An investigation through a questionnaire survey has been conducted on both students' individual characteristics affecting their sound environment perceptions in informal learning spaces (ILSs) of a university campus and their sensitivities to the sound environments in ILSs affecting their preferences for the type of ILSs.
Findings
The research findings indicate that students' sound environment perceptions are associated with some of their individual characteristics. In addition, the results show that students' sound environment sensitivities affect their preferences for the type of ILS they occupy.
Originality/value
This study could help architects and managers of university learning spaces to provide better sound environments for students, thereby improving their learning outcomes. The article contributes valuable insights into the correlation between students' individual characteristics, sound environment perceptions and preferences for ILSs. The research findings add to the existing knowledge in this field and offer practical implications for enhancing design and management of university learning environments.
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Xinying Lv, Rongguo Wang, Wenbo Liu and Long Jiang
The purpose of this paper is to investigate the effect of thermal‐oxidative aging at 150°C on the mechanical properties of carbon fibre reinforced bismaleimide composites.
Abstract
Purpose
The purpose of this paper is to investigate the effect of thermal‐oxidative aging at 150°C on the mechanical properties of carbon fibre reinforced bismaleimide composites.
Design/methodology/approach
Composites specimens after thermo‐oxidative aging at 150°C for various times (up to 1,000 h) were investigated by scanning electron microscopy (SEM) for fracture morphology, Fourier transform infrared (FTIR) spectroscopy for chemical structures, and flexural strength test and inter‐laminar shear strength (ILSS) test for mechanical properties.
Findings
The results indicated that the mechanical properties of carbon fibre/BMI composites were affected significantly by testing temperature rather than by aging time. SEM results showed that the good adhesion of fibre and matrix resulted in the better mechanical properties. The composites showed lower flexural strength and ILSS at 150°C due to the viscoelastic behaviour of matrix resin. The FTIR spectra confirmed the decomposition of crosslinked maleimide occurred just on the surface of composites during various aging times.
Research limitations/implications
Results indicated that carbon fibre/BMI composites had excellent heat resistance and aging resistance.
Practical implications
Due to their excellent thermal and mechanical properties, the carbon fibre/BMI composites show greater potential for their applications in some extreme fields such as aerospace and machine.
Originality/value
The paper investigates the relationships of the fracture morphologies of composites and chemical structures of matrix resin to the mechanical properties after thermo‐oxidative aging.
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Abstract
Purpose
The objective of the present work is to ascertain the failure modes under different loading speeds along with change in percentage of constituents of FRP composites.
Design/methodology/approach
This involves experimental investigation of FRP composites with woven roving fibers and matrix. Different types of composites, i.e. glass: epoxy, glass: polyester and (carbon+glass): epoxy are used in the investigation with change in percentage of constituents. The variability of fiber content of the composite is in the range of 0.55‐0.65 weight fractions. The matrix dominated property, like inter laminar shear strength (ILSS) has been studied by three point bend test using INSTRON 1195 material testing machine with increasing five cross head velocities.
Findings
The variation of ILSS of laminates of FRP composites is significant for low loading speed and is not so prominent for high speed. The variation of ILSS are observed to be dependent on the type and amount of constituents present in the composites. The laminates with carbon fiber shows higher ILSS than that of glass fiber composites. The laminates with epoxy matrix shows higher ILSS than polyester matrix composites for the same fiber. There is no significant variation of ILSS beyond loading speed 200 mm/min and this can be used for specifications of testing. Matrix resins such as polyester and epoxy are known to be highly rate sensitive. Carbon fiber are relatively rate independent and E‐glass fibers are rate sensitive. Woven roving carbon glass fiber reinforced polymer shows small rate dependence and woven roving glass fiber reinforced polymer shows significant rate sensitivity.
Originality/value
The findings are based on original experimental investigations in the laboratories of the institute and can be used for characterization of composites.
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Jia Zhang, Ding Ding, Chunlu Liu, Mark Luther, Jilong Zhao and Changan Liu
The purpose of this paper is to analyse privacy and interaction preferences in the social dimension of individual learning students and how the spatial configuration affects…
Abstract
Purpose
The purpose of this paper is to analyse privacy and interaction preferences in the social dimension of individual learning students and how the spatial configuration affects individual learners’ choices of learning spaces.
Design/methodology/approach
This empirical survey study was conducted in an Australian university’s informal learning spaces. Space syntax theories are applied to construct a four-quadrant theoretical framework.
Findings
The research findings indicate that based on the differences between students in their individual characteristics, there are significant differences in their needs for privacy and interaction. This study reveals that the spatial configuration affects individual learners’ choices of learning spaces.
Originality/value
This study could assist universities in providing students with more effective and diverse informal learning spaces.
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Sakhawat Ali and Shamshad Ahmed
The present research aims to gauge the Information Literacy Skills (ILSs) of the University Library and Information Science Professionals (LISPs) of Pakistan and consider it as a…
Abstract
Purpose
The present research aims to gauge the Information Literacy Skills (ILSs) of the University Library and Information Science Professionals (LISPs) of Pakistan and consider it as a forecaster of improved Research Support Services (RSSs).
Design/methodology/approach
The purposive sampling method through a questionnaire was applied and administered (online and offline) to assemble data from LISPs of 219 universities of Pakistan. The questionnaire covered the eight factors of ILSs and four of RSSs.
Findings
The regression model illustrates that the predicted variation of ILSs in RSSs is statistically significant. The coefficient of determination (R2) indicates that ILSs predict 70% variance in RSSs. Furthermore, the beta coefficient demonstrates that the input value of “managing findings” toward improved RSSs is moderately high as compared to other factors of ILSs. Therefore, the study concludes that ILSs of LISPs are a prerequisite for their professional growth to improve their RSSs.
Originality/value
The research has discovered the whole levels of ILSs and RSSs of the university LISPs of Pakistan. The study recommends raising the ILSs of LISPs to provide more efficient RSSs.
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The purpose of this paper is to analyze microstructural integrity at the interface and consequent implicating effect on mechanical behavior of fiber‐reinforced polymer composites.
Abstract
Purpose
The purpose of this paper is to analyze microstructural integrity at the interface and consequent implicating effect on mechanical behavior of fiber‐reinforced polymer composites.
Design/methodology/approach
In the light of Fourier transform infrared spectroscope (FTIR imaging) and temperature‐modulated differential scanning calorimeter, a sorption mechanism was established. Thermal spike and thermal shock treatment was carried out at 150 and 80°C, respectively. This suggested that fiber/matrix adhesion rests on the structure and properties of both the fiber and matrix in the region near the interface during the hygrothermal treatment.
Findings
The carbon surface was found to selectively absorb the tertiary amine catalyst and to modify the chemical state of the cured resin apparently through the effects of absorbed water. The higher values of glass transition temperature (Tg) resulted in longer immersion time and higher exposure temperature. Together, these techniques provide a comprehensive picture of chemical and physical changes at the interphase region. Thermal spike of hybrid composite at 150°C temperature might possibly improve the adhesion level at the interface. Whereas, in case of thermal shock treatment at 80°C the fall in inter‐laminar shear strength value at higher number of cycles. This degradation of the interface region has been monitored by scanning electron microscope analysis.
Originality/value
The reported data are based on experimental investigation.
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Jin Xue and Matthew Tingchi Liu
Live streaming sales (LSS) is an emerging and flourishing practice in the retail industry. While its implementation has been pervasively attempted, there is a lack of systematic…
Abstract
Purpose
Live streaming sales (LSS) is an emerging and flourishing practice in the retail industry. While its implementation has been pervasively attempted, there is a lack of systematic and academic exploration of the practice. Therefore, the aim of this study was to investigate the LSS ecosystem and its development through a literature review and an industry analysis. Moreover, by pinpointing the pitfalls in current practices, this paper presents the practical implications of LSS and provides recommendations and directions for future academic exploration.
Design/methodology/approach
The aim of the present study was to investigate the developing trajectory, exclusive elements (such as multi-channel networks (MCNs) and live streamers) and other critical components of the LSS ecosystem using a mixed-methods approach that comprises content analysis of newspaper articles and press releases, literature view and industry analysis.
Findings
The results of the analyses indicate the presence of several nonfungible modular components in the LSS ecosystem, including upstream suppliers, MCNs, live streamers and platforms. It was also found that inequalities and hierarchies are inherent to the LSS ecosystem as it currently exists: low-end participants in the LSS industry and small- and medium-sized enterprise owners, who constitute the majority of LSS practitioners, cannot reach the break-even point via LSS hosted by top-level live streamers or others (low-level live streamers, employees, etc.).
Originality/value
This article discusses the LSS ecosystem based on the nature of the nonfungible modules within it. In addition, it discusses the modules (roles) and relationships among them based on the theory of ecosystem developed by previous studies. Furthermore, drawing from an analysis of the pitfalls in the LSS ecosystem, this article highlights strategies for two critical e-commerce processes: 1) choosing which type of LSS to apply based on the factors of brands, products and consumers and 2) integrating LSS to optimize post-sale service and appeal to the sustainability of development.
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