Passive solar design strategies for buildings are necessary for annual heating energy demand reduction. This paper presents a mathematical model for interior room temperature calculation of a building that integrates a combined passive solar system consisting of an unvented Trombe wall and a direct passive solar system for direct insolation. The model was applied to a residential building located in Niš, Serbia, which is not additionally heated by conventional fuels. Two variations of a combined passive system were taken into consideration. The first combined passive system consisted of a Trombe wall made of 0.45-m-thick concrete and the second combined passive system consisted of a 0.20-m-thick concrete Trombe wall. To calculate the complex mathematical model, depending on the size of the window opening, window slope (slanting or vertical position), and orientation of the room, two software packages were developed, RMSun and InSunTr. In addition, the indoor air temperatures of a thermally insulated residential building with an unvented Trombe wall and a direct passive solar system for different building orientations and different Trombe wall thicknesses were analyzed during the winter period between January and March.

Aims and background: Mining and energy complexes in Serbia are recognized as a major source of a large number of pollutants. Serbia’s environmental performance reports clearly indicate that large mining and energy complexes are the dominant source of air pollution. It is difficult to determine which of them remarkably threaten the quality of the environment, as all the basic elements of the environment (air, water, and soil) are threatened, not just one. Mining and energy complexes significantly reduce the quality of the immediate environment, as the distance areas throughout water and air pollution propagation. Additional motivation for this study lies in the fact that large mining and energy complexes are particularly interesting because they are located in the immediate vicinity or large rivers (mostly the Danube), which are protected in many national and international legislation acts (particularly the Danube). The basis for the preservation of environmental quality is an effective environmental management system (EMS) in mining and energy complexes. The aim of this study is to promote and elaborate the possibility for improving the mining and energy complex environmental protection/management system by applying the basic principles of sustainable development. Methodology: Project management methodology is selected as a tool. Project management is based on the application of a network planning technique (Critical Path Method), because of its suitability for representing the logical structure of environmental protection system. The survey was conducted in the area of the city of Kostolac. The examined area included mining and energy complexes in Kostolac, which incorporate three surface mines (Ćirikovac, Klenovik, and Drmno) and two thermal power stations (TE “Kostolac A” (100 MW) and TE “Kostolac B” (2 × 348.5 MW)). The PSR model (Pressures, State, Response) was used for the organization of the interactions within “society–environment” system as the basis for indicator selection. Results: Procedures to identify and determine the significance of the environmental aspects should be established by executive staff in mining and energy plants and complexes. Identification of environmental aspects is the first part of the planning system of environmental management and the activities related to them. The accomplishment of critical path activities represents the basis for improving the environmental protection system in mining and energy complexes. Discussion: Application of sustainable development principles depends on the country’s energy potential and the application of the adopted environmental policy regarding mining and energy complexes. Strict enforcement of existing laws and regulations presents an opportunity to rectify many shortcomings while providing economic benefits, restoring the usable value of ravaged land, and preserving air and water quality.

This paper analyzes the specific absorption rate and the temperature elevation of the brain within an adult?s man head exposed to electromagnetic radiation. The source of electromagnetic radiation is a contemporary mobile phone operating at 900 MHz. Simulations were performed on an anatomically accurate AustinMan 2.6 voxel-based human model with a resolution of 1 ? 1 ? 1 mm3. The thermal analysis focuses on temperature distribution on the brain surface in fixed time steps during one hour of continuous mobile phone use.

This paper explores the distribution pattern of SAR1g within the adult male head during utilization of hands-free operation of contemporary mobile phones as a source of electromagnetic radiation. The research assesses the optimal positioning of the mobile phone by examining three distinct orientations to determine the minimal SAR1g distribution compared to the conventional talking position when hands-free feature is not utilized. The analysis encompasses GSM bands operating at 900 MHz and 1800 MHz, depending on the alignment between the mobile phone and the head.

Knowledge about decision analytics and knowledge management is essential when it comes to using renewable energy sources. Strategic energy management and education indicators play an important role in the application of modern technologies. Knowledge management can provide significant long-term energy benefits while requiring the same level of financial investment. The use of renewable energy sources necessitates a high level of knowledge management, particularly during the installation phase. Importing modern energy plants in the energy sector is possible, but it is not always the best solution. This paper discusses the importance of knowledge management and having educated personnel. Engineers need to know how to perform tasks related to the installation and maintenance of alternative energy plants. Education indicators are essential for avoiding problems and ensuring effective strategic management. Knowledge is a key resource that provides a competitive advantage in the European market. One of the most crucial requirements for achieving the energy policy goals is the Energy Sector Development Strategy of the Republic of Serbia up to 2025, with projections up to 2030. Effective education indicators and adequate decision-making in the field of applying renewable energy sources are also crucial for the maintenance of installed equipment. A lack of knowledge management during the implementation phase can lead to shorter exploitation periods and technical problems.

Children's everyday use of mobile phones exposes them to significant levels of electromagnetic radiation, causing public concern over the potential adverse effects. This paper discusses the magnetic field distribution from a mobile phone at the frequencies of 0.9, 1.8, and 2.1 GHz through a child head model. Human tissues and organs are represented in terms of their corresponding electromagnetic properties. The results of magnetic field distribution for a horizontal cross-section of the child head model at the three given frequencies are presented in the paper.