The discourse surrounding sustainability, particularly in the urban environment, has gained considerable momentum in recent years. The concept of a smart city epitomises the integration of innovative technological solutions with community-centred approaches, thereby laying the groundwork for a sustainable lifestyle. One of the crucial components of this integration is the effective and innovative management of waste. The aim of this article was to classify scientific research pertaining to waste management within the context of smart city issues, and to identify emerging directions for future research. A systematic literature review, based on a bibliometric analysis of articles included in the Scopus and Web of Science databases, was conducted for this study. The purpose of such a systematic review is to identify, integrate, and evaluate research on a selected topic, using clearly defined criteria. The research query included: TITLE-ABS-KEY (“smart city” AND (waste OR garbage OR trash OR rubbish)) in the case of Scopus, and TS = (“smart city” AND (waste OR garbage OR trash OR rubbish)) in the case of the Web of Science database. A total of 1768 publication records qualified for the analysis. This study presents an investigation into the current and forthcoming directions of waste management in smart cities, synthesising the latest advancements and methods. The findings outline specific future research directions encompassing technological advancement, special waste challenges, digitisation, energy recovery, transportation, community engagement, policy development, security, novel frameworks, economic and environmental impact assessment, and global implications. These insights reflect a multifaceted approach, advocating a technology-driven perspective that is integral to urban sustainability and quality of life. The study’s findings provide practical avenues for cities to enhance waste management through modern technologies, promoting efficient systems and contributing to sustainable urban living and the circular economy. The insights are vital for policymakers and industry leaders globally, supporting the creation of universal standards and policies, thereby fostering comprehensive waste management systems aligned with global sustainability objectives.

The influence of artificial intelligence (AI) in smart cities has resulted in enhanced efficiency, accessibility, and improved quality of life. However, this integration has brought forth new challenges, particularly concerning data security and privacy due to the widespread use of Internet of Things (IoT) technologies. The article aims to provide a classification of scientific research relating to artificial intelligence in smart city issues and to identify emerging directions of future research. A systematic literature review based on bibliometric analysis of Scopus and Web of Science databases was conducted for the study. Research query included TITLE-ABS-KEY (“smart city” AND “artificial intelligence”) in the case of Scopus and TS = (“smart city” AND “artificial intelligence”) in the case of the Web of Sciences database. For the purpose of the analysis, 3101 publication records were qualified. Based on bibliometric analysis, seven research areas were identified: safety, living, energy, mobility, health, pollution, and industry. Urban mobility has seen significant innovations through AI applications, such as autonomous vehicles (AVs), electric vehicles (EVs), and unmanned aerial vehicles (UAVs), yet security concerns persist, necessitating further research in this area. AI’s impact extends to energy management and sustainability practices, demanding standardised regulations to guide future research in renewable energy adoption and developing integrated local energy systems. Additionally, AI’s applications in health, environmental management, and the industrial sector require further investigation to address data handling, privacy, security, and societal implications, ensuring responsible and sustainable digitisation in smart cities.

The article addresses the issue of the future of European universities on the path to sustainable development. The main aim of the article is to describe foreseeable future directions of the sustainable development of universities and ways to achieve Sustainable Development Goals. In effect, the authors identify weaknesses, assess threats and recommend coordinated solutions and alternatives for the sustainable development of universities. This research will contribute to future work by explaining what the future of universities will look like on their sustainability journey. The results of the Delphi study conducted with the participation of 201 experts from 47 countries allowed for the identification of factors shaping the future of universities on the path to sustainable development.

Nowadays, start-ups, assuming increasing importance, have the possibility to include intangible knowledge as another resource on which they can carry out planning exercises, impact studies, evaluation and monitoring, protection, accumulation and exploitation. The study carried out in this paper allows us to analyze the influence that intangible knowledge has on the financial status of a start-up and, therefore, on its economic sustainability. This enables start-ups to present a good image, become more transparent, have more opportunities, reduce uncertainty, improve sustainability, etc. Moreover, the study presents a descriptive analysis of intangibles according to regions and activity sectors. An analysis of variance was carried out, to see if there is a relationship between the investment in intangible assets and the activity sector and/or regions to which the company belongs. The study concludes that, among all sectors, the differences in the incorporation of intangible assets into financial statements are most recognized in tourism, which may be a key factor for the sustainability of this sector, especially in periods of economic crisis, such as the one Europe and the planet are currently facing.

In this research, a study is carried out on the differences between tourism start-ups in relation to intangibles, economic and financial sustainability, by region and by sector of activity, in order to determine their sustainability both in a situation of economic crisis and growth, In the study carried out in this article, the tourist startups are identified, by branch of activity (hotels, restaurants, transport and travel agencies) with identification of intangibles in their balance sheet. Once identified, a descriptive analysis of the incorporation of intangibles, economic sustainability and financial sustainability, by branch of activity and community, is developed. This analysis is completed with an analysis of variance to determine if there is a relationship between intangible and branches of tourism and region; economic sustainability and branches of tourism and region; financial sustainability and branches of tourism and region. The conclusions of the work show that parameters such as investment in intangibles, economic sustainability and financial sustainability are key variables in crisis situations such as the current one.

RESUMEN El estudio de la estructura financiera de las empresas sigue siendo uno de los temas financieros que más interés suscita, entre otros motivos y según Myers (2001), porque no existe una teoría universal sobre la estructura financiera y, es mas, no hay razones para esperarla. Partiendo de esta situación nos planteamos analizar los efectos de la dimensión empresarial y de pertenencia a un sector, dos factores tradicionalmente aceptados por la literatura financiera como determinantes de la estructura de capital, sobre la estructura financiera de las empresas pertenecientes a la Comunidad Autónoma Andaluza. Para ello hemos utilizado una muestra de 6.338 empresas andaluzas en el periodo 2001. Los resultados reflejan como las empresas andaluzas están muy endeudadas, siendo las empresas de reducida dimensión, y las que pertenecen a los sectores de la construcción y servicios las más apalancadas. PALABRAS CLAVE: estructura de capital, sector de actividad, tamaño. ABSTRAC This paper analyse the relevance of two key factors in determining the capital structure of companies: firm size and industry classification. Our analysis has been carried out on 6.338 andalusian companies for 2001 period. The results of our study show that andalusian companies are highly leveraged. Besides small firms are more level of debt than medium and large firms. The results also indicate that the companies that belong to construction and business services sectors have the highest debt ratios. KEY WORDS: capital structure, industry classification, size firm.