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1

Impact of high order harmonics on the motor copper losses and operating characteristics

Temelkovski Ivan, Rafajlovski Goran, Cvetkovski Goga, Digalovski Mihail

Przegląd Elektrotechniczny

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2025

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R. 101, nr 3

120--123

EN

In this paper, a three-phase low-voltage squirrel cage induction motor is considered. From the short-circuit test, the operating characteristics are obtained in two different ways: once when the induction motor is connected directly to the network and another when the motor is inverter fed. Furthermore, an analysis of the high order harmonics is given and the copper losses that occur during the no-load test of the induction motor are determined. A qualitative analysis of the results is given and the significant impact of the inverter on the copper losses is highlighted.

PL

W artykule rozpatrzono trójfazowy silnik elektryczny klatkowy niskiego napięcia. Charakterystyki pracy uzyskuje się z próby zwarciowej na dwa różne sposoby: raz, gdy silnik elektryczny jest bezpośrednio podłączony do sieci, i drugi, gdy silnik jest zasilany z falownika. Dodatkowo przeanalizowano harmoniczne wyższego rzędu i określono straty w miedzi powstałe podczas testu silnika indukcyjnego bez obciążenia. Przedstawiono jakościową analizę wyników i podkreślono istotny wpływ falownika na straty w miedzi.

2

Multi‑criteria analysis of the resistance of ETICS with fire barriers to environmental factors

Sudoł Ewa, Piekarczuk Artur, Mazurek Aleksandra, Kozikowska Ewelina

Materiały Budowlane

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2025

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nr 8

50--60

EN

Long‑lasting exposure was simulated on a thermal insulation model based on expanded polystyrene with a mineral wool strip. The second exposure sequence caused the top layer cracking. The crack width in the barrier area exceeded 0.2 mm, suggesting a loss of watertightness. 3D scanning and inspection analysis was used for deformation assessment. It revealed deformation within the mineral wool strip. A decrease in the top layer adhesion to the thermal insulation material was reported.

PL

Model ocieplenia na bazie ekspandowanego polistyrenu z pasem wełny mineralnej poddano długotrwałej ekspozycji. Druga sekwencja oddziaływań skutkowała pęknięciami warstwy wierzchniej. W obszarze bariery przekroczyły one szerokość 0,2 mm, co wskazuje na utratę wodoszczelności. Do oceny deformacji zastosowano skanowanie 3D z analizą inspekcyjną. Uwidoczniło ono deformację w obrębie pasa wełny mineralnej. Odnotowano zmniejszenie przyczepności warstwy wierzchniej do materiału termoizolacyjnego.

3

Assessing the perception gap: mining impacts from community and company perspectives in Nigeria

Ikechukwu Mbachu

Journal of Sustainable Mining

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2025

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Vol. 24, iss. 1

89--101

EN

The study intends to evaluate how mining companies and their host communities perceive the impacts of mining operations and to ascertain if there are significant differences in how both parties perceive the impacts of mining in Nigeria. The study was carried out in twelve states in Nigeria and covered the six geopolitical zones in Nigeria. Data was collected through a questionnaire and interviews carried out separately with community members and company representatives. The study investigated ten categories of mining impacts such as socioeconomic, environmental, health, physical and so on. To gauge the perceptions of the respondents on the different impact categories, the Likert scale was used. The Student’s t-test was then used to determine whether there are statistically significant differences in perceptions in each impact category. The study findings showed significant differences in how communities and mining companies perceive the impacts of mining. Out of the ten impact categories assessed, statistically significant differences in perception were observed in nine categories. The only category where there was no significant difference in perception between mining companies and communities was related to conflicts arising from mining operations. Shrinking these perception gaps is key to ensuring sustainable mining practices in Nigeria.

4

Impact of offshore wind farms on the fauna of the Baltic Sea

Cieślewicz Natalia, Pilarski Krzysztof, Pilarska Agnieszka Anna

Journal of Ecological Engineering

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2025

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Vol. 26, nr 4

1--14

EN

This paper addresses the issues arising from the correlation between upcoming investments in the development of offshore wind energy and the fauna of the Baltic Sea. It presents the challenges related to the construction of offshore wind turbines and the requirements set by the European Union. Information regarding the fauna of the Baltic Sea and the threats to the body of water resulting from human activities is provided. Conclusions are drawn regarding aspects of offshore wind farms (OWFs) that may be harmful to the fauna of the Baltic Sea, as well as those that have a positive impact on animals. Finally, solutions are proposed to mitigate the negative effects of OWFs on the marine environment and enhance their positive impact.

5

Analiza numeryczna efektów uderzenia pociskiem stalowym oraz lodowym na podstawie założeń normy PN-EN ISO 9806

Kozłowski Marcin, Gawron Łukasz

Inżynieria i Budownictwo

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2025

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R. 81, nr 2

128--132

PL

Norma PN-EN ISO 9806 wyróżnia dwie podstawowe metody badania kolektorów słonecznych na uderzenie gradem: uderzenie kulą lodową z dużą prędkością oraz zrzut kuli stalowej z wysokości do 2 m. W artykule przedstawiono wstępnie badania porównujące efekty uderzenia kulą stalową oraz lodową w blachę stalową, które przedstawiają podstawowe różnice w badanym zjawisku. Analizę porównawczą przeprowadzono za pomocą symulacji numerycznej, stosując Metodę Elementów Skończonych oraz metodę bezsiatkową Smoothed-particle hydrodynamics, a także wykorzystując metodę explicit w oprogramowaniu Ansys LS-Dyna. W wyniku przedstawionych analiz wykazano silną konserwatywność uproszczonej metody badawczej (zrzut kuli stalowej) w stosunku do metody podstawowej (uderzenie kulą lodową z dużą prędkością). Maksymalne ugięcia blachy stalowej uderzonej kulą stalową charakteryzowały się wartościami zawyżonymi o 49% w stosunku do uderzenia pociskiem lodowym. Rozkłady naprężeń oraz odkształceń również w sposób znaczący wskazywały na silną konserwatywność uderzenia kulą stalową. Na podstawie zachowania się pocisków w czasie trwania zderzenia wywnioskowano, że główną przyczyną różnic w uzyskanych wynikach jest odmienna charakterystyka zastosowanych materiałów w zakresie rozproszenia energii kinetycznej. Pocisk lodowy wykazał silne zniszczenie w całej objętości, rozpraszając energię w procesie pękania oraz rozpadu pocisku. Pocisk stalowy wykazał wyłącznie lokalne uplastycznienie, znacząco słabiej rozpraszając energię uderzenia. Badanie odporności kolektorów słonecznych przez upuszczanie kuli stalowej jest podejściem atrakcyjnym pod kątem kosztów badań z uwagi na brak konieczności stosowania drogiej aparatury badawczej. Symulacja numeryczna wskazała jednak na znaczną konserwatywność tego podejścia, co może skutkować zaniżoną ekonomicznością projektowanych kolektorów słonecznych.

EN

The PN-EN ISO 9806 standard distinguishes two methods for testing solar collectors for hail impact: high-velocity ice ball impact and the drop of a steel ball from a height of up to 2 meters. The article presents initial studies of a comparison of the effects of steel and ice ball impacts on a steel sheet, highlighting the fundamental differences in the investigated phenomenon. The comparative analysis was conducted using numerical simulations with the Finite Element Method and the meshless Smoothed-Particle Hydrodynamics (SPH) method, employing the explicit approach in Ansys LS-Dyna software. The analyses demonstrated the strong conservatism of the simplified testing method (steel ball drop) compared to the primary method (high-velocity ice ball impact). The maximum deflections of the steel sheet caused by the steel ball impact were overestimated by 49% compared to the ice projectile impact. The stress and strain distributions also significantly indicated the strong conservatism of the steel ball impact. Based on the behavior of the projectiles during the collision, it was concluded that the main cause of the differences in the obtained results is the distinct energy dissipation characteristics of the materials used. The ice projectile demonstrated significant damage throughout its entire volume, dissipating energy through cracking and fragmentation. The steel projectile, on the other hand, showed only local plastic deformation, dissipating the impact energy much less effectively. Testing the resistance of solar collectors by dropping a steel ball is a cost-effective approach due to the absence of the need for expensive testing equipment. However, the numerical simulation indicated a significant conservatism of this approach, which may result in a reduced economic of the designed solar collectors.

6

Thermodynamic Analysis and Impact of Quenching on Microstructure & Mechanical Properties of High Silicon Ductile Iron

David Joseph B., Pustal B., Weirich T., Bührig-Polaczek A.

Archives of Foundry Engineering

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2025

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Vol. 25, iss. 1

43--51

EN

Solid-solution-strengthened ferritic ductile iron (SSFDI) exhibits superior tensile strength to elongation ratios up to a critical silicon content of 4.3 wt.%. Beyond this threshold, this material experiences a sudden drop in ultimate tensile strength and elongation at breakage. Previous studies indicate that this is may be because of the formation of superstructures like B2 and D03 especially at regions with high silicon content. This study aims to comprehend thermodynamics behind phase transition during solid-state transformation in high silicon ductile iron. Using thermodynamic simulations, this current investigation tries to pinpoint the transition temperature from the ferritic phase to superstructure formation especially B2 superstructure. Additionally, analysis is made to see consequences of quenching above this transition temperature on microstructure, and mechanical properties. The results contribute insights into phase transitions in high silicon ductile iron, offering practical guidance for optimizing heat treatment processes. By isolating the transition temperature and evaluating the impact of quenching, we provide actionable strategies for controlling microstructural evolution and enhancing mechanical performance in SSFDI. In conclusion, this research represents a crucial advancement in realizing the full potential of high silicon ductile iron for engineering applications. The findings deepen our understanding of the material's behavior and furnish practical approaches for improving its mechanical properties through controlled heat treatments and quenching processes.

7

The restitution coefficient value and damage of composite shields protecting the chassis of a rail vehicle

Juzun Mateusz, Pawlak Mariusz

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 4

140--155

EN

To protect the undercarriage of a railway vehicle moving at high speeds, rolling stock manufacturers use shields made of polymer composites. During operations, damage to these guards is often observed due to railway ballast hitting them. Verification of the course of the impact and the extent of damage caused to these shields has drawn attention to the potential effect of the structural damping of the material on the impact resistance of these shields. This property is expressed by the coefficient of restitution, which determines the amount of energy absorbed by the material during the impact, and its direct influence on the simulation results is rarely a separate research subject. In this paper, an attempt was made to verify the influence of this coefficient on the compliance of railway ballast impact simulation results with the results of bench tests. Two test stand were built for this purpose: to measure the coefficient of restitution of the composite samples and to verify the impact resistance of shields The principle of the restitution coefficient tester is based on the ISO 10545-5 standard and its operation is based on measuring the time elapsed between two consecutive impacts of a steel ball on the surface of the tested specimen. The experimental tests carried out led to the determination of the coefficient for the composite material adopted. This material was a laminate of flax fibres and epoxy resin with a core of 2 different types of materials, i.e., XPS and EPS, and the coefficient values obtained were 0.74 and 0.69 respectively. Knowing these values allowed us to relate the extent of damage caused to the value of the restitution coefficient. To simulate the impact of the railway ballast on the casing, a second test bench was prepared, which allowed the impact to be reproduced. The observed significant effect of restitution coefficient on the results confirmed the validity of the assumption.

8

Equations of physics that have most important impact on electromechanical engineering

Gieras Jacek F.

Przegląd Elektrotechniczny

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2024

|

R. 100, nr 1

1--8

EN

The following equations, laws and principles have been discussed: Newton's second law of motion, Hamilton's principle, Euler-Lagrange equation, wave equation, the first and the second law of thermodynamics, Bernoulli's equation, Ohm’s laws for electric and magnetic circuit, Kirchhoff’s laws for electric and magnetic circuits, Maxwell’s equations, Lorentz force equation, Einstein’s energy-mass relation, Einstein field equations , Planck's equation, Heisenberg’s uncertainty principle, Schrödinger wave equation, and Dirac equation.

PL

Omówiono następujące równania, prawa i zasady: drugie prawo dynamiki Newtona, zasada Hamiltona, równanie Eulera-Lagrange'a, równanie falowe, pierwsza i druga zasada termodynamiki, równanie Bernoulliego, prawa Ohma dla obwodu elektrycznego i magnetycznego, prawa Kirchhoffa dla obwodów elektrycznych i magnetycznych, równania Maxwella, sila Lorentza, zależność energia-masa Einsteina, równania pola Einsteina, równanie Plancka, zasada nieoznaczoności Heisenberga, równanie falowe Schrödingera i równanie Diraca.

9

Physico-Chemical and Biological Characteristics of the Oum Er Rbia Estuary (North Atlantic Moroccan Coast) – Impact of Urban Wastewater

Bengriche Rachida, Bouchafra El Mostafa, Chaouite Jamila, Nafia Mohammed, Moncef Mohammed

Journal of Ecological Engineering

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2024

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Vol. 25, nr 1

1--16

EN

This study aimed to monitor abiotic factors at three stations in the Oum Er Rbia estuary, not far from the mouth. The stations were situated upstream (S1), in front (S2) and downstream (S3) from the discharge of urban wastewater from the town of Azemmour, which is discharged directly without treatment near the estuary mouth. The selection of these stations appeared appropriate to assessing the quality of the waters, which are influenced by both marine hydrodynamics resulting from very low freshwater inflows and sewage discharges. Monitoring of several parameters, including temperature, pH, dissolved oxygen, conductivity, salinity, turbidity, as well as the content of chlorophyll α and pheopigments, enabled the examination of the impact of marine hydrodynamics and the and the specific characteristics of the three surveyed stations. The analyses were performed using R software version 4.2.0. The results obtained indicate that the studied physico-chemical and biological parameters exhibited variations with significant correlations. Statistical approaches allowed the determination of profiles for stations S1, S2 and S3. It is evident that S1 (located slightly far from the discharge) showed a profile that tended to differ from the other two stations, S2 and S3, especially for certain parameters (temperature, pH, turbidity, and chlorophyll a). On the other hand, all stations were impacted to some extent by the discharge of wastewater during rising tides. The present study can serve as an assessment tool to support decision-making regarding the physico-chemical quality of the waters of the Oum Er Rbia estuary.

10

Airport as a factor shaping the socio-economic situation in the municipality in a changing reality

Piotrowska-Trybull Marzena, Kozuba Jarosław, Sirko Stanisław

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

|

z. 121

167--188

EN

Airports, as a component of air transport, combine air transport with other modes of transport to strengthen the transportation accessibility of a place in space, attract investors, and stimulate the development of the area. Taking into account that these issues are less exposed in relation to their immediate surroundings, research was undertaken to determine how representatives of the authorities and residents of communes (taking into account the nature of the communes and the size and location of the airport) perceive airports, located within their communes, in the context of their impact on the socio-economic situation in the communes. This was achieved by analysing the communes' strategic documents and data on the operation of communes and airports from 2016 to 2021. These data were obtained from the Civil Aviation Authority, the Central Statistical Office, the International Air Transport Association, and the International Airports Council. In an effort to better understand the relationship between the airport and the commune in which it is located, poll research was carried out using survey and interview techniques. The research focused on 10 airports spread across Poland. A total of 1,200 surveys were conducted among residents of communes, and 10 interviews were conducted with representatives of local governments and the port. To analyse the collected data and present the results, Statistica v.13.3 and R/RStudio software were used.

11

Novel energy-absorbing auxetic sandwich panel with detached corrugated aluminium layers

Al-Rifaie Hasan

Vibrations in Physical Systems

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2023

|

Vol. 34, nr 2

art. no. 2023215

EN

Sandwich panels have the potential to serve as plastically deforming sacrificial structures that can absorb blast or impact energies. Auxetic sandwich panels with welded or bolted corrugated layers have, as far as the author is aware, had their blast behaviour thoroughly addressed in the literature. Therefore, the objective of this numerical analysis was to create a novel, low-cost, simple-to-build graded sandwich panel with detached corrugated layers that may be employed as a multi-purpose sacrificial protective structure against a wide range of blast threats. The suggested sandwich panel has overall dimensions of 330x330x150mm and is made of six detached aluminium (AL6063-T4) layers enclosed in a steel (Weldox 460E) frame. With different stepwise plate thicknesses of 0.4, 0.8, and 1.2mm for each pair of layers, the six layers all have the same re-entrant auxetic geometry. Utilising the Abaqus/Explicit solver, the numerical analysis was carried out. A wide variety of blast intensities (4, 7, 11, 13, and 16 MPa peak reflected over-pressures) were tested on the suggested auxetic sandwich panel, and the results showed uniform progressive collapse, a superior decrease in reaction forces, and greater energy dissipation compared to comparable non-auxetic topologies. The innovative sandwich panel design has potential uses for both military and civic structures that need to be protected.

12

Vibroacoustic Helicopter Impact on Elevated Helipad

Cieślak Sławomir, Krzymień Wiesław

Transactions on Aerospace Research

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2023

|

Nr 1 (270)

1--9

EN

A helicopter landing and taking off on an elevated helipad is a source of noise that affects the environment and causes vibrations of the landing pad or the building infrastructure. Vibrations are also excited by the air stream flowing through the main rotor and transferred to the landing pad by contact of the helicopter chassis. Vibrations are transferred to the building through the structure of the helipad. Depending on the damping properties of the structure and the vibro-isolating elements used, vibrations can be felt in rooms used by people and also transmitted to devices located in the building. The subject of the study described in this paper is the vibroacoustic effects of an EC-135 helicopter on an elevated landing pad during landing, standstill with the propulsion system engaged and take-off. Measurements of vibrations and noise were made at points located both on the landing pad and in the building. The paper presents selected results of measurements in various phases of flight and helicopter manoeuvres. The frequency analyses of the fragment of the measurement data for the flight phase, in which the highest levels of impact were recorded, were also performed and included. The results are presented as graphs and annotated.

13

Assessment of the Impact of a Recultivated Landfill on the Soil Environment

Pusz Agnieszka, Wiśniewska Magdalena, Rogalski Dominik, Staśkiewicz Marcin

Journal of Ecological Engineering

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2023

|

Vol. 24, nr 12

407--418

EN

Recultivated landfills, despite remedial actions, may pose a threat to human health and the environment, and therefore require long-term monitoring. The aim of the work was to investigate the impact of recultivation treatments on changes in the physical and chemical properties of soils in the vicinity of a landfill for waste other than hazardous and neutral. In order to carry out the work, drillings were made around the tested landfill, from which samples were taken and selected physical and chemical properties were determined, including substances causing risks that are particularly important for the protection of the earth’s surface. The tested soils were characterized by a neutral and alkaline reaction and a high degree of saturation of the sorption complex with exchangeable basic cations after the use of dust and ash as a recultivation material. Leaks and leachate accumulation were found in the northern part of the facility. The permissible metal contents for industrial areas (group IV) and forest areas (group III) were not exceeded. In the northern part of the landfill area, the permissible content of cadmium was exceeded, while in the southern part, the permissible content of zinc, lead and cadmium was exceeded for agricultural areas (group II). The use of dust and ashes for the recultivation of the landfill in its southern part limited the migration of pollutants deeper into the profile and resulted in an improvement in the physical and chemical properties of the tested soils. The conclusion stated that there is a need to undertake further remediation activities and monitoring studies in order to minimize potential migration of pollutants into the soil and water environment, posing a threat to human health and the environment.

14

Impact of Waste on the Quality of Water Resources – Case Study of Taza City, Morocco

Abouabdallah Amina, El Hammoudani Yahya, Dimane Fouad, Haboubi Khadija, Rhayour Khadija, Benaissa Chaimae

Ecological Engineering & Environmental Technology

|

2023

|

Vol. 24, iss. 9

170--182

EN

The ultimate purpose behind this study is to assess the quality of water surface of Oued Inaouen and its tributaries and some underground stations before and after discharge of the city of Taza. It addresses the leachate of the unauthorized landfill of Taza which is a source of nuisance that adds to the many problems of contamination of the surrounding environment if they are not treated before discharge. This survey explains how the landfill can affect the quality of water resources near the city of Taza, represented by the main tributaries of the watershed of Oued Inaouen by determining the main parameters indicators of pollution, and to study the possibilities of contamination of groundwater and surface water by infiltration or flow of leachate. Physico-chemical results show high concentrations of organic matter, the BOD5 /COD ratio indicating a biodegradable organic fraction. As far as mineral pollution is concerned, high contents of NH4+, NO3-, total phosphorus and Cl-, which explains the high conductivity values. Bacteriological analyses show significant quantities of coliforms and fecal streptococci. For the evaluation of the pollution of groundwater and surface water, the results obtained are translated by the presence of a significant contamination that differs from one point to another. To evaluate the pollution of groundwater and water surface, the results obtained are translated by the presence of a significant contamination that differs from one point to another.

15

Study of the head and neck injury risk under impact conditions of the light UAV with a medium weight

Wang Jiaming, Li Zhigang, Lan Hiuqing, Cao Liying, Hao Zengtao, Bai Chunyu, Yang Zhen

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 4

art. e226, 1--21

EN

The increased number of accidents involving UAVs striking people has caused great societal concern. Therefore, it is necessary to study the threat potential and severity of ground collision accidents of UAVs. This study analyzed the head and neck injury risk resulting from the impact of medium-mass UAVs. First, the finite element (FE) model of the M200-Hybrid III 50th dummy was established, in which the M200 itself had been validated against drop tests, and then the M200-Hybrid III 50th model was validated based on the experimental data of the M200 impacting on the dummy head. High consistency between the simulations and the experiments was observed. Second, simulations were conducted to analyze the head and neck injury severity at different impact speeds, angles, and locations of the M200. As the impact speed increases, HIC15 increases exponentially and Nij increases linearly. It is found that the critical speed range causing injury for both vertical and horizontal impacts is 7-9 m/s. As the impact angle increases, HIC15 varies in the form of the sum of an inverse proportional function and a linear function, and Nij increases in the form of the sum of power and quadratic function. In addition, the battery-first and the top of mainframe impacts lead to the highest probability of head and neck injury among different impact locations, while the landing gear-first is the lowest. Finally, a biomechanical model (THUMS) was incorporated to develop the M200-THUMS model to study the tissue-level injury of the head and neck under different impact conditions. The simulation results show that neck is prone to ligament injury under vertical impact, while the skull is more likely to be fractured under horizontal impact.

16

Influence of Water-Jet on Micro-Formed Parts Process via Nano-Indentation and SEM Analysis

Quaisie James Kwasi, Yamba Philip, Mwinteribo Tabie Vitus, Akayeti Anthony, Kukurah Jamal-Deen, Mohammed Abdul-Hamid

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no. 2

353--361

EN

Based on the experimental study of cavitation water jet impact on microforming, a single round hole micro-die was used in this paper. The effect of different process parameters on the performance of 304 stainless steel foil was examined, which involves the nanometer hardness, and elastic modulus. The nano-indentation tester was used to test the nano-hardness of the formed part, and the performance of the workpiece before and after the impact was analyzed. The nano hardness and elastic modulus increased significantly with an increase in the incident pressure. When the incident pressure was 20 MPa and the impact time of 5 min, the hardness increased by at least 122%, and the elastic modulus increased by at least 76%. After the cavitation water jet shocked the metallic foil of the SEM analysis and the results indicated that, as the incident pressure increases, the surface morphology of the formed part changes from approximately spherical to spherical, and the spherical roundness increases. In addition, there were different degrees of defects at the bottom of the formed part, and as the incident pressure increased, the bottom defects became more and more obvious, from micro-cracks to micro-layer cracks.

17

Impact of the COVID-19 pandemic on real estate market in Cracow

Żabówka Rafał, Maciuk Kamil

Zeszyty Naukowe. Transport / Politechnika Śląska

|

2022

|

z. 114

211--224

EN

The purpose of this study was to determine the impact of the COVID-19 pandemic on the Cracow real estate market. The data used in the study included transactions of purchase of flats and single-family houses. At the initial stage, the database was reduced by applying a four-step selection and outliers were removed. The data analysis included separate transactions for single-family houses and flats, 5 different types of charts were prepared for each type of real estate. The conducted research concerned: the analysis of the number of transactions in subsequent years, the share of the number of transactions in individual quarters, average transaction prices (for houses) or average prices per square meter (for flats), analysis of the number of transactions in individual districts, years and quarters, and a comparison of the number of contracts in individual quarters given years. The main conclusion drawn from the study is the significant impact of COVID-19 on the number of house and apartment purchase transactions, while the pandemic did not have a significant impact on the average prices in the analysed database.

18

Diagnostyka uszkodzeń żelbetowej, monolitycznej ściany w realizowanym budynku wielorodzinnym

Niedostatkiewicz Maciej, Majewski Tomasz

Materiały Budowlane

|

2022

|

nr 11

25--28

PL

W artykule przedstawiono przypadek uszkodzenia żelbetowej monolitycznej ściany, do którego doszło podczas demontażu systemowych szalunków prefabrykowanych. Przedmiotowa ściana znajdowała się w hali garażowej wielorodzinnego budynku mieszkalnego. Nastąpiło wówczas gwałtowne zniszczenie demontowanego szalunku, a spadające płyty uderzyły w rozszalowywany fragment niedawno zabetonowanej ściany. W miejscach uderzenia przy górnej krawędzi ściany beton uległ wykruszeniu, a w górnej części ściana rozwarstwiła się na odcinku ~200 cm na grubości przekroju i pręty zbrojenia uległy wygięciu. Uszkodzenia oraz morfologia rys i pęknięć jednoznacznie wskazywały na brak spójności betonu na grubości i wysokości ściany. Nieznany był jednak zakres rozwarstwienia. W celu określenia zakresu występujących uszkodzeń, ich wpływu na bezpieczeństwo konstrukcji budynku oraz możliwości bezpiecznego kontynuowania prac budowlanych wykonano badania ultradźwiękowe oraz sklerometryczne ściany w obszarze uderzenia. Wyniki przeprowadzonych badań i pomiarów opisane zostały w artykule. Na podstawie przeprowadzonej analizy stanu istniejącego zaproponowano sposób naprawy części uszkodzonej ściany.

EN

The paper presents a case of damage to a monolithic reinforced concrete wall during assembly works. The wall in question was located in the garage hall of a multi-family residential building. During improperly conducted construction works related to the dismantling of the shuttering boards with the use of a crane, they broke rapidly, and the falling boards hit the recently concreted wall of the garage hall. As a result of the impact, the concrete wall delaminated at the length of ~200 cm in the middle of its thickness, the reinforcement bars bent, and concrete losses were visible at the upper edge. The scope of damage and the morphology of scratches and cracks indicated the lack of cohesion of the concrete in the thickness and height of the wall. In order to assess the extent of the damage, its impact on the safety of the building structure and the possibility of safe continuation of construction works, ultrasonic and sclerometric tests were performed, the results of which are discussed in the paper. Based on the obtained results, a repair method was proposed and the area of the wall requiring repair was determined.

19

Physico-Chemical Characterization of Medical Solid Waste Leachate: Case of the Hospital de l'Amitié of Nouakchott, Mauritania

Ammar Mohamed Bouna, Dick Brahim Ahmed, Sidi Yahya Maham Ould, Dieh H., Mohamed L. S., Lemine Y. M., Sadegh Vadly, Fekhaoui Mohamed

Journal of Ecological Engineering

|

2022

|

Vol. 23, nr 8

181--186

EN

At the Hospital de l'Amitié, hospital waste corresponds to a mixture of waste assimilated to household waste and the waste from healthcare activities with infectious risks. In the context of hospital hygiene, the conducted study focuses on the impact of this hospital waste on the people of the Hospital de l'Amitié and the environment, and their handling of hospital waste (collection and transport). From an environmental point of view, the physico-chemical characterization of the leachate leaving submerged waste in three media (drinking water, distilled water and alcoholic distilled water) show high concentrations for most of the parameters studied. Physico-chemical characterization of solid waste from Hospital de l'Amitié in Nouakchott (Mauritania) was carried out from September to December 2020. The objective was to determine the value of 14 parameters (pH, temperature, turbidity, electrical conductivity, COD, BOD5, COD/BOD5, BOD5/COD, SS/BOD5, SS, nitrite, nitrate, sulfate and phosphorus), and improve the treatment method for this solid waste by immersing it in three different mediums (drinking water, distilled water and alcoholic distilled water). Among the 14 parameters, seven exceeded the Moroccan and WHO standards for medium 1, 2 and 3 respectively, conductivity (5340.00 μs/cm, 5820.00 μs/cm and 3550.00 μs/cm), BOD5 (122.00 mg/L, 106.00 mg/L and 142.00 mg/L), BOD5/COD (2.30, 1.93 and 2.88), SS (1000.00 mg/L, 600.00 mg/L and 600.00 mg/L), nitrite (0.91 mg/L, 25.00 mg/L and 45.00 mg/L), nitrate (210.00 mg/L, 200.00 mg/L and 110.00 mg/L) and sulfate (1000.00 mg/L, 2000.00 mg/L and 1000.00 mg/L). These results indicate the existence of toxic substances in these leachates that may impact the environment. In addition, the study proposes solid waste treatment from the Hospital de l'Amitié in Nouakchott (Mauritania) before its discharge into the natural environment. This observation is consolidated by the analyses carried out on the leachate of the waste immersed in three aqueous media (drinking water, distilled water and alcoholic distilled water).

20

Changing of Soil Properties under Drought and Saline Water Intrusion Conditions in Different Land-Use Patterns – A Case Study in the Ben Tre Province, Vietnam

Loi Le Tan, Minh Vo Quang, Duy Nguyen Ngoc

Journal of Ecological Engineering

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2022

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Vol. 23, nr 8

112--118

EN

The study aimed to assess the change of soil properties of land use patterns affecting drought and saline intrusion in the Ben Tre province during 2019–2020. Soil samples were taken, and the data on land use patterns of Rice, bare soil, Shrimp, and Coconut in three horizons were at 0–20 cm, 20–60 cm, and 60–100 cm. The analysis of soil pH, EC, organic matter, and bulk density was conducted to assess the changes in soil properties. The results showed that soil pH, EC, and salinity had to be slightly increased in 2020, but soil organic matter and bulk density were not changed. Therefore, the Ben Tre province’s drought and saline intrusion conditions had a negligible impact in general evaluation. However, it is necessary to perform more other studies to clarify the effects of drought and salinity.