Investigation of flexural properties of epoxy composite by utilizing graphene nanofillers and natural hemp fibre reinforcement

This study aims to determine the optimum reinforcement required to attain the best combination of flexural strength of modified green composites (graphene oxide + hemp fibre reinforced epoxy composites) for potential use in structural applications. An attempt was also made for the combination of graphene and hemp fibres to enhance load-bearing ability. The infusion of hemp and graphene was made by the weight of the base matrix (epoxy composite). Results showed that graphene reinforcement at 0.4 wt.% of matrix showed load-sustaining capacity of 0.76 kN or 760 MPa. In the case of hemp fibre reinforcement at 0.2 wt.% of the matrix, infusion showed enhanced load-bearing ability (0.79 kN or 790 MPa). However, the combination of graphene (0.1 wt.% graphene nanofillers) and hemp (5 wt.% hemp fibre) indicated a load-sustaining ability of 0.425 kN or 425 MPa, whereas maximum deflection was observed for specimen with hemp 7.5 % + graphene 0.2 % with 1.9 mm. Graphene addition to the modified composites in combination with natural fibres showed promising results in enhancing the mechanical properties under study. Moreover, graphene-modified composites exhibited higher thermal resistance compared to natural fibre reinforced composites. However, when nanofiller reinforcement exceeded a threshold value, the composites exhibited reduced flexural strength as a result of nanofiller agglomeration

An overview of burst, buckling, durability and corrosion analysis of lightweight FRP composite pipes and their applicability

© 2019 Elsevier Ltd. All rights reserved.The main aim of this review article was to address the performance of filament wound fibre reinforced polymer (FRP) composite pipes and their critical properties, such as burst, buckling, durability and corrosion. The importance of process parameters concerning merits and demerits of the manufacturing methods was discussed for the better-quality performance. Burst analysis revealed that the winding angle of ±55° was observed to be optimum with minimum failure mechanisms, such as matrix cracking, whitening, leakage and fracture. The reduction of buckling effect was reported in case of lower hoop stress value in the hoop to axial stress ratio against axial, compression and torsion. A significant improvement in energy absorption was observed in the hybrid composite pipes with the effect of thermal treatment. However, the varying winding angle in FRP pipe fabrication was reported as an influencing factor affecting all the aforementioned properties. Almost 90% of the reviewed studies was done using E-glass/epoxy materials for the composite pipe production. By overcoming associated limitations, such as replacing synthetic materials, designing new material combinations and cost-benefit analysis, the production cost of the lightweight FRP composite pipes can be decreased for the real-time applications.Peer reviewe

‘They had to Go’: Indian Older Adults’ Experiences of Rationalizing and Compensating the Absence of Migrant Children

Abstract: In transnational families, it is often the older adults who are left-behind or choose to stay behind. Currently the population aged 60 years and older in India constitutes over 7 percent of the total population (1.25 billion) and is projected to triple in the next four decades. In the past family has been the major source of support in later life. One of the consequences of increased mobility is the decreasing role of family in care provision. The Indian middle-class norms on higher education, which stressed on engineering and medicine, have resulted in professionally educated children leaving the parental home to seek work and thus family life in other geographical locations. In this paper we examine how transregional and transnational mobilities and the resulting absences impact the lives of older adults. We draw upon 37 in-depth interviews conducted in Dharwad district of Karnataka, India. The results show that older adults employ two strategies of rationalizing absence and compensating absence of migrant children. These strategies reflect the resilience of the older adults to make sense of this trans-local family life, that in a previous generation they were not aware of

‘They had to Go’: Indian Older Adults’ Experiences of Rationalizing and Compensating the Absence of Migrant Children

Abstract: In transnational families, it is often the older adults who are left-behind or choose to stay behind. Currently the population aged 60 years and older in India constitutes over 7 percent of the total population (1.25 billion) and is projected to triple in the next four decades. In the past family has been the major source of support in later life. One of the consequences of increased mobility is the decreasing role of family in care provision. The Indian middle-class norms on higher education, which stressed on engineering and medicine, have resulted in professionally educated children leaving the parental home to seek work and thus family life in other geographical locations. In this paper we examine how transregional and transnational mobilities and the resulting absences impact the lives of older adults. We draw upon 37 in-depth interviews conducted in Dharwad district of Karnataka, India. The results show that older adults employ two strategies of rationalizing absence and compensating absence of migrant children. These strategies reflect the resilience of the older adults to make sense of this trans-local family life, that in a previous generation they were not aware of

Thermogravimetric pyrolysis investigation of pistachio shell for its potential of thermal properties, kinetics and thermodynamics

Abstract In order to design and optimize thermochemical systems for the production of bioenergy understanding the energy capacity of the pistachio shell and its kinetics of degradation is crucial. The Thermogravimetric analysis at different heating rates of biomass was studied along with thermodynamic study, primary characterizations like the composition of biomass, heating value and a reaction mechanism-assisted kinetic model. Nitrogen gas flow rate is used for thermogravimetric analysis (TGA), which is performed at 10, 15, 20 and 30 ℃/min different heating rates from room temperature to 900 ℃. The output also shows that maximal degradation took place between 180 and 430 °C. The various iso-conversional models, such as Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), Starink and Friedman, are used to calculate kinetic and thermodynamic parameters, which give the average value of activation energy as 172.29, 170.47, 169.79, and 193.25 kJ/mol. The average values of Gibbs free energy for the FWO, KAS, Starink and Friedman techniques were found to be 176.49, 1176.54, 176.29, and 175.78 kJ/mol, respectively. Graphical Abstrac