Scientific Review Engineering and Environmental Sciences (SREES)

Investigations of stress and strain state of aluminum alloys during a hot extrusion and patterns of structure and feature formation

Suren G. Aghbalyan — 2024-02-01

This paper investigates the stress and strain state as well as formation processes of structure and features of aluminum alloys during the hot extrusion. It has been shown that during the hot extrusion the ring layers of an extruded element experience not only longitudinal and transverse deformations, but also a slip. The slip increases from inner layers to the surface layer. The tensile principal stresses and the sum of slip deformations also increase. It has been also demonstrated that at the exit of the pressing part the tensile principal stresses have different directions, forming an angle with extruder axis, which also increases towards the surface. In conclusion, it has been stated that the main radial and circumferential deformations act as restraining deformations.

Sustainable debris management by linear dynamic transportation model

Abdulamir Hussein Qasim — 2024-02-22

Management of large debris caused by building demolition necessitates a multi-faceted approach to deal with emerging side effects.‎ Because of emerging global challenges, such as population growth, and renovation ‎projects, a dynamic models need to be planned and controlled. One of the key drivers ‎of this management is determining the appropriate path for transporting waste and debris. Debris management by using the linear dynamic transportation model (LDT) is conducted to deal with the unexpected amount of debris and other solid waste. This sudden and unexpected large ‎amount of solid waste might be produced by natural disasters or by man-made catastrophes either ‎directly or indirectly. By computing several parameters in certain zones, a sensitivity ‎analysis of each parameter is performed to obtain an optimal model for disaster debris ‎management. Based on disaster debris volume, the model gave us an optimal explanation of ‎the debris disposal by locals. According to the estimated parameters and conditions, ‎significant findings appear by identifying the optimal dynamic transportation path of the debris ‎truck. Thus, by applying the LDT model, the results showed that the efficiency/inefficiency of road types and networks clearly affect the handling of debris.

Cost analysis of water charge rates in the Czech Republic – Case study

Aneta Oblouková — 2024-02-01

The article was conceived as an initial insight into the issues related to the representation of individual type costs (e.g. material, labor costs, property depreciation, etc.) in the price of water in the Czech Republic. The aim of the article was to point out the possibility of dependence between the size of the company operating the infrastructural property of water supply and sewerage and the representation of individual costs in the water price within the framework of the case study. As a sample that formed the outputs of the case study, 14 companies were taken, which were selected according to the unified regions of the Czech Republic. Both basic mathematical methods and elementary methods used in financial analysis were used in the analysis. Within the scope of the case study, it can be stated that there is no dependence between the size of the companies and the representation of costs. Among the largest costs from the point of view of financial representation are other direct costs, where the costs of depreciation, property repairs, rental property, as well as wage costs and material costs are mainly represented. Insignificant costs include, for example, energy costs, which are only represented in the range of 1.39–5.70% of the total costs. Therefore, in order for the results included in the case study to be considered statistically relevant, it is necessary to expand the sample and confirm or refute the initial findings published in this article.

Application of UAV and ground measurements for urban vegetation cooling benefits assessment, Wilanów Palace case study

Michał Trzeciak — 2024-01-26

This research at the Wilanów Palace, Warsaw, assesses urban greenery’s cooling impacts in a cultural heritage site using remote sensing and on-site measurements, highlighting vegetation’s importance in urban climate control. The study combines soil temperature data, UAV thermal imagery, leaf area index (LAI), LiDAR, and NDVI analyses. Findings demonstrate a strong link between vegetation density and temperature: UAV land surface temperature (LST) ranged from 26.8° to 47.5°C, peaking at 72°C, while ground-based temperatures were between 19.5° and 29.2°C, lowest in dense vegetation areas. The statistical analysis confirmed significant temperature differences across vegetation types, with higher LAI areas showing lower temperatures. These results validate the cooling effect of dense vegetation, emphasizing green spaces’ significance in urban climate regulation within cultural heritage sites. The study informs sustainable urban design and conservation, underlining the critical role of vegetation in improving urban microclimates.

Hybrid wavelet transform – MLR and ANN models for river flow prediction: Case study of Brahmaputra river (Pancharatna station)

Sachin Dadu Khandekar — 2024-02-28

In this research, discrete wavelet transform (DWT) is combined with MLR and ANN to develop WMLR and WANN hybrid models, respectively, for the Brahmaputra river (Pancharatna station) flow forecasting. Daily flow data for the period of 10 year were decomposed (up to fifth level) into detailed and approximation coefficients (using Daubechies wavelets db1, db2, db3, db8 and db10) which were fed as input to MLR and ANN to get the predicted discharge values two days, four days, seven days and 14 days ahead. For all lead times, the WMLR-db10 model was found to be superior as compared to WANN-db1, WANN-db2, WANN-db3, WANN-db8, WMLR-db1, WMLR-db2, WMLR-db3, WMLR-db8 and single MLR and ANN models. During testing period, the values of determination coefficient (R²) and RMSE for WMLR-db10 model for two-, four-, seven- and 14-day lead time were found to be, respectively, 0.996 (751.87 m³·s^–1), 0.991 (1,174.80 m³·s^–1), 0.984 (1,585.02 m³·s^–1), and 0.968 (2,196.46 m³·s^–1). Also, it was observed that for lower order wavelets (db1, db2, db3) WANN’s performance was better, and for higher order wavelets (db8, db10) WMLR’s performance was better. Correspondingly, it was observed that all hybrid models’ efficiency increased with increase in the decomposition level.

Support vector regression tree model for the embankment breaching analysis based on the Chamoli tragedy in Uttarakhand

Sitender — 2024-03-18

This study used the analysis to provide considerable support of historical distortion in the Himalayan Chamoli tragedy of 2021. According to multi-objective data and survey results, a precursor event occurred in 2016, and a linear fracture grew at joint planes, suggesting that the 2021 rock ice avalanche will fail retrogressively. To analyze breaching, this study considers seven distinct criteria such as slope, water pressure, and faulty drainage, hydrostatic stress, agricultural operations, cloudbursts, and road building. Based on these characteristics, the support vector regression (SVR) model is utilized to analyze the sensitivity of the link between these parameters. The application of support vector regression analysis on the Chamoli instance confirmed our conclusion that embankment breaching causes glacier retreat and other consequences in increasing sensitivity to the characteristics of fractured rock masses in tectonically active mountain belts. Recent advances in environmental monitoring and geological monitoring systems can be used with the proposed SVR model to provide further information on the location and time of the impending catastrophic collapses in high hill regions.