Titanium alloy Ti-6Al-4V possesses excellent mechanical and corrosion-resistant properties; therefore, it is widely employed in aerospace, automotive, and biomedical fields. However, its poor machinability restricts traditional processing methods. To overcome this limitation, the current work presents a symmetry analysis approach to evaluate the effects of tool coating on the micro-electric discharge machining (micro-EDM) characteristics of Ti-6Al-4V. Tungsten carbide (WC) microelectrodes were fabricated in three forms: uncoated, copper-coated, and carbon-coated. The chemical vapor deposition (CVD) method was used to coat the carbon layer, and the integrity of the coating was confirmed by Energy-Dispersive X-ray Spectroscopy/Analysis (EDS/EDX). The effect of input variables—namely, voltage, capacitance, and spindle rotational speed—on two responses was studied—the machining depth (Z-axis displacement) and tool wear rate (TWR)—using a Taguchi L9 orthogonal array. Analysis conducted using Minitab statistical software 17 revealed that both voltage and capacitance contributed to the response parameters as optimized variables. The comparative study showed that the copper- and carbon-coated WC microtool could obtain a better Z coordinate and lower tool wear ratio compared with those of the uncoated tool. The findings confirm that applying thin conductive coatings to WC tools can significantly improve the stability, precision, and overall symmetry of the micro-EDM process when machining difficult-to-cut titanium alloys.

High-rise building facades offer an alternative site for installing photovoltaic panels, which are traditionally placed on rooftops. The unique spatial configuration of high-rise buildings, characterized by a small footprint area relative to their height, supports the application of vertical facades for this purpose. Photovoltaic panels installed in these areas not only generate electricity but also enhance the aesthetic dimension of the urban landscape. The proposed methodology uses the EnergyPlus software to simulate the electricity generation of photovoltaic panels mounted on the walls of high-rise buildings in the city of Kragujevac, Serbia. A technical, economic, and environmental analysis was conducted for two scenarios: (1) photovoltaic panels installed on two facade areas with the highest solar potential, and (2) photovoltaic panels installed on all four available facade areas. In Scenario 1, the annual reduction in electricity consumption, annual cost savings in electricity consumption, and investment payback period range from 13 to 38%, 11 to 31%, and 8.4 to 10.6 years, respectively. In Scenario 2, these values range from 23 to 58%, 18 to 47%, and 10.9 to 12.9 years, respectively. The results indicate that southeast and southwest facades consistently achieve higher levels of electricity generation, underscoring the importance of prioritizing high-performing orientations rather than maximizing overall surface coverage. The methodology is particularly efficient for analyzing the solar potential of numerous buildings with comparable shapes, which is a characteristic commonly found in Eastern European architecture from the late 20th century. The study demonstrates the applicability of the proposed methodology as a practical and adaptable tool for assessing early-stage solar potential and providing decision support in urban energy planning. The approach addresses the identified methodological gap by offering a low-cost, flexible framework for assessing solar potential across diverse urban contexts and building typologies, while significantly simplifying the modeling process.

The size, shape, and articulation of buildings create shadows at different times of day and year that may limit the penetration of direct sunlight onto both public spaces. In this paper, the impact of shadows on public sport playgrounds in the city of Kragujevac was analyzed. Seven such playgrounds, located between multi-family buildings in the center of the city of Kragujevac, were included in study. The shadows impact was analyzed for September 21st and December 21st, since these playgrounds can be used throughout the year. The shadow impact criterion is based on the concept of the Sun Access Factor as a measure of Sun penetration on a given area, during a specified time frame. Based on the calculated values of the Sun Access Factor, an analysis of the shadows impact on the sports fields was performed by comparing it with the internationally used values

Roofs and walls of buildings represent an important location for the installation of photovoltaic systems in urban areas. High-rise buildings, with a specific spatial shape, provide the possibility of installing these systems both on the roof and on the exterior walls. Possible way to increase the efficiency of solar systems is to use solar tracking systems which maximize electricity production. In this paper, a simulation of photovoltaic systems installed on the roof and walls of a high-rise building in the city of Kragujevac, Serbia was performed, using fixed installation and installations with single and dual axis systems for solar tracking. The simulation was performed in the EnergyPlus software. The results show that usage of solar tracking systems increases electricity production, especially dual axis system for solar systems with an unfavourable orientation.