We present an innovative enthalpy method for determining the thermal properties of phase change materials (PCM). The enthalpy-temperature relation in the “mushy” zone is modelled by means of a fifth order Obreshkov polynomial with continuous first and second order derivatives at the zone boundaries. The partial differential equation (PDE) for the conduction of heat is rewritten so that the enthalpy variable is not explicitly present, rendering the equation nonlinear. The thermal conductivity of the PCM is assumed to be temperature dependent and is modelled by a fifth order Obreshkov polynomial as well. The method has been applied to lauric acid, a standard prototype. The latent heat and the conductivity coefficient, being the model parameters, were retrieved by fitting the measurements obtained through a simple experimental procedure. Therefore, our proposal may be profitably used for the study of materials intended for heat-storage applications.

The paper deals with the issues of the influence of forest cover on the average annual runoff of rivers in the Pripyat River basin. In the study area, under the influence of solar radiation, the temperature of the air and the soil surface increases, evaporation from the water surface also increases, and the moisture content of the upper layers of the soil decreases. In general, with an increase in forest cover, the annual layer of the runoff of the studied rivers increases, as well as with an increase in the amount of precipitation (in contrast to the runoff of short-term floods). However, with a forest cover of more than 20%–30% and a relatively small amount of precipitation, the runoff decreases, which is associated with the retention of part of the precipitation by the forest cover. With a large amount of precipitation and low forest cover, the runoff also decreases, which is probably due to the loss of precipitation water for evaporation, etc. The conducted studies show that, just as the forest affects water resources, the flow of moisture to watersheds also affects the state of forest systems. Moreover, this interaction is expressed by evaporation from forests. Under influence of change of a climate growth of evaporation is observed.

The present paper discusses the case of the Madrid Nuevo Norte Project (MNNP) in order to examine the relation of this mega-project with the city’s sustainable development. For this reason, the study used a qualitative approach using semi-structural interviews with experts (Madrid’s town hall, Madrid State, and the program management office and other external) that relayed strongly with MNNP. The expert panel requirements are split in six expertise areas: sustainability, urban development, urban planning, government or public affairs, project management or Madrid Nuevo Norte (MNN) key stakeholders. The study highlighted the vital importance of MNNP as a flagship sustainable project for the rest of Europe, that meets sustainability criteria for contributing substantially in the improvement of the quality of life of final users and for the community in general. For instance, it contributes to the regeneration of the city’s degraded area, to the interconnection of an isolated part of the city and public transportation connection, improving the external image of Madrid. Despite of it, there are some challenges that should be carefully managed such as applying sustainable solutions from other cities not properly tailored to Madrid, housing pricing accessibility increase due to the lack of terrain in Madrid and the politization of the project as discussion topic between local parties. In this context, local authorities should give particular emphasis in complying with the principles of sustainability for improving the overall performance of MNNP, ensuring social justice and prosperity for the people of Madrid.

Global energy agencies and commissions report a sharp increase in energy demand based on commercial, industrial, and residential activities. At this point, we need energy-efficient and high-performance systems to maintain a sustainable environment. More than 30% of the generated electricity has been consumed by HVAC-R units, and heat exchangers are the main components affecting the overall performance. This study combines experimental measurements, numerical investigations, and ANN-aided optimization studies to determine the optimal operating conditions of an industrial shell and tube heat exchanger system. The cold/hot stream temperature level is varied between 10 ℃ and 50 ℃ during the experiments and numerical investigations. Furthermore, the flow rates are altered in a range of 50–500 L/h to investigate the thermal and hydraulic performance under laminar and turbulent regime conditions. The experimental and numerical results indicate that U-tube bundles dominantly affect the total pumping power; therefore, the energy consumption experienced at the cold side is about ten times greater the one at the hot side. Once the required data sets are gathered via the experiments and numerical investigations, ANN-aided stochastic optimization algorithms detected the C10H50 scenario as the optimal operating case when the cold and hot stream flow rates are at 100 L/h and 500 L/h, respectively.

This research article explores the intricate relationship between cultural impacts and leadership styles in social science management. It emphasizes the importance of cultural-informed decision-making, highlighting its role in fostering inclusive managerial choices. The study also delves into how diverse leadership styles enhance team dynamics and collaboration, contributing to an innovative work environment. While recognizing the potential benefits, challenges like miscommunications are acknowledged, with recommendations for leadership development programs. The research underscores the significance of leadership flexibility in managing diverse teams. In conclusion, the article emphasizes the positive impact of cultural awareness on decision-making, collaboration, and innovation in social science management.

This study examined the factors influencing the organizational satisfaction of employees in public institutions. In the case of public institutions that must provide stable public services on behalf of the government, the organizational satisfaction of employees will be more important. In this regard, this study includes the perception of HRM and trust between employees as affecting factors, and the perception of HRM consisted of sub-components such as fairness of evaluation and excellence of education and training. Moreover, this study considered trust between employees as a mediator. In more specific, online surveys were conducted with 705 employees of public institutions in Korea, and the Structural Equation Model (SEM) was performed. The results indicated that the perception of HRM affected organizational satisfaction directly or indirectly. In addition, trust between employees mediated between all sub-components of perception of HRM and organizational satisfaction. Particularly, trust between employees has been verified to increase the influence of the perception HRM. Meanwhile, in the case of Korea, there are more public institutions than other countries, and many other countries are showing high interest in Korea’s public institution operation system. In this respect, dealing with Korean public institutions as examples provides important international implications.