RESUMO
The utilization of adhesive compounds in bonding lightweight and high-performance composite structures, including carbon fiber reinforced polymer (CFRP) composites, has garnered significant attention from researchers. This study presents the novel application of Al2O3 coated with TiO2 as a thermal protective layer for CFRP substrate. Initially, the CFRP substrate underwent a protective treatment involving the application of Al2O3 as a middle coat, followed by a further protective layer consisting of TiO2 as a top coat. The deposition of TiO2 onto an Al2O3-based thermal barrier coating (TBC) was carried out utilizing the flame spray method. The use of a TiO2 coating as a top coat was employed to enhance protection and heat dispersion across the middle coat and substrate. In order to achieve sufficient adhesion between the CFRP substrate, an intermediate coat consisting of Al2O3 with a Na2SiO3 binder, the impact of varying nozzle distances on adhesion strength and pull-off test outcomes was investigated, with a nozzle distance of 180 mm yielding the highest adhesion strength. The thermal stability of a CFRP substrate was enhanced through the deposition of a layer of TiO2 on Al2O3. The surface and cross-sectional morphologies of the composite were analyzed using a Scanning Electron Microscope (SEM). It was observed that the presence of a TBC on the composite surface effectively reduced the amount of heat that was transferred to the composite material. In order to assess the effectiveness of TBC on CFRP substrates, a series of experiments involving thermal torch and conductivity tests were undertaken. The interaction between the top and middle coats of a composite material results in enhanced mechanical properties, hence improving its thermal insulation capabilities. The artificially produced TBC coatings have the potential to function as adhesive materials, ensuring the sustained high performance of CFRP substrates.
RESUMO
Despite widespread acceptance of sustainability as the ultimate goal of forest management, perspectives about its meaning, significance, and relevant indicators may still differ. This paper examines local perspectives on sustainability, and evaluates their similarities and differences. A systematic procedure based on criteria of proximity, pre-existing rights, dependency, knowledge of forest management, forestry spirit, daily activity, and legal rights was used to identify a small group of relevant stakeholders representing different groups, institutions, and organizations. Using participatory action research (PAR), stakeholders were asked to identify relevant indicators of sustainable forest management. The indicators identified by each stakeholder were then compared to a consolidated list assembled by field facilitators with respect to whether relevant indicators are present or not. Based on the resulting presence/absence matrix, a statistical tool called the simple matching coefficient was used to estimate the similarity measures among the stakeholders' perspectives. In addition, cluster analysis was used to classify groups of stakeholders depending on their similarities to each other. Finally, hypotheses related to the 'closeness' of perspectives among local communities, non-governmental organizations, a timber company, and government organizations, as revealed by their selection of indicators, were tested. Results show that: (a) local communities have different perceptions in terms of what they consider to be important indicators compared to the NGOs, (b) there are significantly different perceptions between the government and the timber companies, and (c) there are also different perceptions between urban and field-based personnel of the same organization.
