Journal of Engineering Sciences / Журнал інженерних наук
Permanent URI for this collectionhttps://devessuir.sumdu.edu.ua/handle/123456789/34326
Browse
3 results
Search Results
Item Durability and FTIR characteristics of sustainable bacterial concrete with mineral admixtures(Sumy State University, 2024) Porselvan, R.; Lakshmi, T.S.; Tholkapiyan, M.The objective of this study is to optimize the concentrations of bacillus megaterium (BM), alccofine (AF), and silica fume (SF) in self-healing concrete while controlling the content of manufactured sand (M-sand). This research addresses the pressing need for sustainable alternatives to traditional cement as excessive energy consumption and environmental impacts continue challenging the construction industry. A novel “binary and ternary blended cementitious system” was developed, featuring twelve distinct mix proportions. M-sand was fully utilized as an acceptable aggregate substitute, with bacterial concentrations of (10–50)·105 cells/ml incorporated to mitigate crack formation. Cement was partially replaced with AF, and the M-sand content was adjusted from 0 to 20 % in 5 % increments. This study also uniquely evaluates the durability properties of the various cementitious systems, including water absorption, concrete density, porosity, long-term strength retention, and rapid chloride permeability – at intervals of 7, 14, and 28 days post-curing. Fourier transform-infrared spectroscopy (FTIR) was employed to analyze calcite precipitation, providing insights into the biochemical mechanisms. The results indicate that while SF demonstrates superior effectiveness compared to AF, combining both enhances durability compared to alternative mixes. The findings reveal that bacterial concrete incorporating zeolites can significantly improve structural strength and be a sustainable building material. Notably, incorporating additional cementitious materials with mineral admixtures increased strength by up to 10 % through optimized bacterial concentrations. The successful precipitation of calcium carbonate confirmed the beneficial properties of the bacterial agents, which are safe and non-toxic to the environment. Overall, this study contributes valuable knowledge on reducing cement usage and carbon dioxide emissions, positioning BM, alongside AF and SF, as a promising approach for environmentally friendly concrete solutions.Item Improvement of the ecological efficiency of synthetic motor fuel production in Ukraine(Sumy State University, 2024) Shulga, I.; Kyzym, M.; Kotliarov, Y.; Khaustova, V.Solving the problem of improving energy security is one of Ukraine’s challenges in modern conditions. One of the ways to solve this problem is to organize the production of synthetic motor fuel from the available domestic carbon-containing raw materials. The relevance of developing the production of synthetic motor fuel in Ukraine from non-oil raw materials is associated with the shortage of deposits of traditional crude hydrocarbon and the destruction of the last processing capacities due to russian aggression. The article aims to substantiate the possibility of efficiently producing synthetic motor fuels from the available mineral hydrocarbon raw materials. Analyzing the existing deposits of hydrocarbons allowed for determining low-metamorphosed coal as the most expedient raw material base. A comparative analysis of various technologies made it possible to suggest the organization of the production of synthetic motor fuel through indirect hydrogenation, followed by fuel synthesis in the Fischer–Tropsch process. Calculations performed for low-metamorphosed Ukrainian coal showed the technical and environmental efficiency of the hydrogen enrichment of synthesis gas. To enrich synthesis gas with hydrogen, it was proposed to cooperate with producing synthetic motor fuel with coal mines (suppliers of raw materials, including methane for the production of additional hydrogen) or coke ovens and by-product enterprises that produce hydrogen-rich coke oven gas.Item Sustainable low carbon urban lighting analysis: a case study of Bandung city(Sumy State University, 2020) Yusup, G.S.B.; Melda, R.J.; Maman, I.; Li, J.Nowadays, lighting technology is in the transition period from conventional lighting to LED, which more environmentally friendly due to free of harmful substances such as mercury, lead, or other hazardous chemicals and gases. This low light pollution because directional light is carefully distributed precisely to the intended location. Performance of the lights also brighter than other lights. This research measuring the reduction of CO2 gas emissions before and after PJU (street lights) in Bandung is changed from the conventional to the LED, also mapping the CO2 gas emissions in six Development Areas (SWK). The basis for this research approach is a case study with before and after comparison, meaning that this approach only applies to one object that is the same as comparing the condition of the object before and after the treatment. In this study, the evaluation research method used is a causal method, which is a method that is more directed at impact evaluation research. Scientifically and objectively, PJU LED provides low CO2 emissions gas by up to 26 % in Bandung city.