Search results

Recent advancements in technology have led to the exploration of solar-based thermal radiation and nanotechnology in the field of fluid dynamics. Solar energy is captured through sunlight absorption, acting as the primary source of heat. Various solar technologies, such as solar water heating and photovoltaic cells, rely on solar energy for heat generation. This study focuses on investigating heat transfer mechanisms by utilizing a hybrid nanofluid within a parabolic trough solar collector (PTSC) to advance research in solar ship technology. The model incorporates multiple effects that are detailed in the formulation.

The mathematical model is transformed using suitable similarity transformations into a system of higher-order nonlinear differential equations. The model was solved by implementing a numerical procedure based on the Wavelets and Chebyshev wavelet method for simulating the outcome.

The velocity profile is reduced by Deborah's number and velocity slip parameter. The Ag-EG nanoparticles mixture demonstrates less smooth fluid flow compared to the significantly smoother fluid flow of the Ag-Fe3O4/EG hybrid nanofluids (HNFs). Additionally, the Ag-Ethylene Glycol nanofluids (NFs) exhibit higher radiative performance compared to the Ag-Fe3O4/Ethylene Glycol hybrid nanofluids (HNFs).

Additionally, the Oldroyd-B hybrid nanofluid demonstrates improved thermal conductivity compared to traditional fluids, making it suitable for use in cooling systems and energy applications in the maritime industry.

The originality of the study lies in the exploration of the thermal transport enhancement in sun-powered energy ships through the incorporation of silver-magnetite hybrid nanoparticles within the heat transfer fluid circulating in parabolic trough solar collectors. This particular aspect has not been thoroughly researched previously. The findings have been validated and provide a highly positive comparison with the research papers.

This paper aims to analyse residents’ perceptions of tourism growth in Porto prior to the COVID-19 pandemic, aiming to determine the most appropriate strategies to mitigate negative tourism impacts. Studies on resident perceptions of tourism impacts are still scarce, particularly the ones addressing the topic in the context of Portuguese urban tourism areas.

Data was collected through an online survey, focusing on three categories of impacts: (i) economic, (ii) sociocultural (iii) and spatial-environmental, and the respective mitigation strategies, analysed from the perspective of Porto’s residents. Descriptive and bivariate statistics – T-test and Eta correlation – were used to analyse the collected data.

Respondents who live in the city centre experience specific tourism impacts more negatively, when compared to those living outside the inner-city area. Furthermore, no strong correlation is found between the said impacts and the respective mitigation strategies. However, creating awareness among tourists about acceptable behaviour in shared spaces is the strategy that stands out, as it has a medium correlation with all three impact categories. Most impact-strategy associations are weak, meaning that the defined strategies are not the most case-appropriate, which is something that policymakers should address.

To the best of the author’s/authors’ knowledge, this is the first study to adopt this approach in tackling the negative impacts of rapid tourism growth in Porto.

Cyber violence is a global emerging issue which is growing with technology or online spaces, having a great influence on individual’s development. The purpose of this study is to identify the dominant factors of cyber violence and its influence on the cognitive development of female undergraduate students.

In this quantitative study, a questionnaire is used as a data collection tool. Moreover, this research is conducted on female undergraduate students (n = 300). Whereas, the purposive sampling technique is used and Statistical Package for Social Science (SPSS 27.0) software is used to analyze the data.

The findings of this study show that cyber bullying is the dominant factor of cyber violence, whereas cyber doxxing has high influence on cognitive development of female undergraduate students. In addition, the value of correlational coefficient is 0.683, which indicates a strong positive correlation. Therefore, it supports that the null hypothesis is rejected and alternative hypothesis is accepted.

The findings of this study are of great importance for policymakers to update the regulations for cyber violence and provide the protection laws for victims whereas it is helpful for the investigation agencies and cybercrime units to be more active and needs to take immediate actions on reported incidents to minimize its further spread and support victims of it. Also, it helps society to understand the influence of it on cognitive health, which helps them to create a safer environment. Similarly, parents and teachers need to make a safe and comfortable environment around children and keep an eye on them. Further, it is beneficial for companies or online platforms to keep their sites or apps more secure for the users. Moreover, future research studies could expand the topic by involving different genders and age group peoples by using different methodologies to explore in depth.

This study is unique as there are limited studies, which identify the factor of cyber violence and its influence on cognitive development. Also, fewer studies can be seen in the context of Pakistan.