Hardness in water, primarily caused by calcium and magnesium ions, poses significant operational, environmental, and health-related challenges. This study evaluates the potential of Aspergillus niger biomass (AN) and coconut-based activated carbon (AC) as lowcost biosorbents for water softening. Batch experiments were conducted to investigate the effects of contact time, shaking speed, pH, and adsorbent dosage on hardness removal from artificial hard water. The results demonstrate that both sorbents exhibit relatively rapid initial ion uptake, reaching equilibrium after 7 hours for AN and 11 hours for AC. Shaking speed showed only minor influence beyond 150 rpm, indicating that external mass transfer limitations were minimized at moderate agitation. Within the pH range of 5–9, hardness removal remained nearly constant, whereas literature data indicate a sharp increase in removal efficiency at pH values above 10 due to enhanced surface negativity. Increasing adsorbent dose improved removal efficiency up to a saturation threshold, with optimal performance observed at 15–20 g of biosorbent. Overall, A. niger biomass demonstrated promising softening capabilities, suggesting its potential application as an economical and sustainable alternative to conventional water softening technologies.
Celem niniejszego artykułu jest podstawowa analiza finansowa spółek funkcjonujących w sektorze produktów rafinacji ropy naftowej. Analiza finansowa bazuje w głównej mierze na wskaźnikach rentowności, płynności, sprawności działania oraz zadłużenia. Poza analiza wskaźnikową przedstawiono również podstawowe analizę sektora dla badanych przedsiębiorstw. Przeprowadzona analiza dla przedsiębiorstw z sektora paliwowego w latach 2019–2023 ukazuje zróżnicowaną sytuację finansową firm w dynamicznie zmieniającym się otoczeniu rynkowym i geopolitycznym. Badany okres charakteryzował się istotnymi wyzwaniami, w tym pandemią COVID-19, wojną w Ukrainie, kryzysem energetycznym na Bliskim Wschodzie oraz globalnym dążeniem do ograniczenia emisji i osiągnięcia neutralności klimatycznej do 2050 roku. Wpływ tych czynników jest widoczny w wynikach analizowanych wskaźników.
The liquidation of many industries has made it necessary to reuse abandoned industrial landscapes. As a result of development,post-industrial facilities may be created that have been changed morphologically or functionally. Post-industrial facilities were usedfor various purposes. Today they perform the following functions: industrial, service (mainly commercial), often administrative,educational, as well as tourist and recreational. One of the popular methods of preserving post-industrial heritage is its transformationfrom a fully industrial facility into a tourist resource. Some can simply become recreational or entertainment places, they can also betransformed into tourist facilities such as hotels, restaurants, etc. All kinds of activities aimed at transforming post-industrial areasinto tourism-related facilities not only give them a chance to gain a "second life", but they fit into the socio-economic revitalizationstrategies of a given country. They are part of the general shift towards territorial development and allow for the use of the growingdemand for postmodern cultural consumption. The article presents examples of the use and development of post-industrial facilitiesremaining after the liquidation of many industries in Poland, Slovakia, and China. They show that cultural heritage sites have becomepopular tourist attractions. Special attention was paid to facilities used for tourism and cultural tourism. The diversity of post-industrial heritage and the purpose of local post-industrial facilities are shown. Some of them constitute the most valuable elements ofpost-industrial cultural heritage and are included on the UNESCO list.
Cenozoic basalts of Central Vietnam represent a promising geological setting for carbon capture and storage (CCS) through mineral carbonation. In this study, the Cenozoic basalts in Central Vietnam are investigated to estimate their potential for long - term CO₂ sequestration. F ormed during the complex tectonic evolution of Southeast Asia associated with Indo - Australian and Eurasian plate convergence and the opening of the East Sea, these volcanic fields cover approximately 20,000 – 23,000 km² with individual f lows reaching thicknesses of 300 – 600 m. Major basaltic plateaus, including Pleiku, Buon Ma Thuot, Kon Plong, Da Lat, and Xuan Loc are composed mainly of tholeiitic and alkaline basalts rich in olivine, pyroxene, and plagioclase. These minerals supply dival ent cations (Ca²⁺, Mg²⁺, Fe²⁺) that are highly reactive with CO₂, favoring long - term storage through mineral carbonation. Structural features such as fractures, vesicular zones, and columnar jointing enhance porosity and permeability, while weathered horiz ons and lateritic interbeds provide natural seals. Hydrogeological conditions include both confined and unconfined aquifers that must be carefully managed to ensure safe injection and containment. CO₂ sequestration mechanisms involve initial physical trapp ing followed by permanent geochemical fixation as stable carbonates. Lessons from global projects, such as CarbFix in Iceland and Wallula in the United States, highlight the feasibility of basalt - based CCS. With suitable geological conditions, proximity to major CO₂ sources, and integration into national climate policy, Central Vietnam’s basalts offer significant potential to contribute to Vietnam’s net - zero emission goals by 2050.
The Field Y, located in the Cuu Long Basin, Vietnam, is currently being explored and developed for its potential in the Lower Miocene reservoirs. However, one of the key challenges faced by geologists and well log analysts is the presence of low-resistivity, low-contrast (LRLC) pay zones, which hinder the accuracy of log interpretation and evaluation. Calculating water saturation in these low-resistivity zones using conventional interpretation techniques often results in significant errors, potentially leading to the misidentification of productive intervals. This paper determines the primary causes of low resistivity, including the influence of invasion zones, well and formation dip, limitations of logging tools, grain size, clay content and distribution, and formation water salinity. The authors propose the Leverett J-function method, independent of resistivity, to calculate water saturation. This method aims to improve the calculation of net pay thickness in the Well X, Field Y. Results show that in the Lower Miocene formation, the net pay thickness of the BI.2.20 interval increased by 2,773 meters and the BI.1.20 interval increased by 1,981 meters. This improvement helps to avoid misidentification of productive zones and ultimately increase recoverable reserves.
This paper reviews the calculation of shear studs in the load introduction area (LIA) of concrete-encased steel composite columns, focusing on their role in transferring shear forces between the concrete and the embedded steel section. Based on recent literature, especially the stiffness-based approach proposed by Grzeszykowski et al. (2023), the study highlights key factors influencing shear transfer, such as load distribution, material properties, and stud arrangement. Through a critical review of current design practices and assumptions in international codes, the paper identifies limitations in traditional strength-based methods, particularly at service load levels. In contrast, the stiffness-based method (StiffM) considers partial interaction and connector stiffness, offering a more realistic evaluation than the conventional strength-based method (StrM). Case studies are briefly discussed to demonstrate the practical implications of adopting a stiffness-based design perspective, which may improve structural efficiency and safety.
Cao Bang Province, Vietnam, is facing a water shortage that affects daily life and the economic development of the locality, especially in mountainous areas. The study of the impact of natural, and socio - economic conditions on the stability of groundwater in some highland regions where water is scarce in Cao Bang province is the basis for developing a suitable water exploitation management plan, ensuring the lives of local people. By collecting documents, conducting field surveys, consulting with the community, and analyzing samples in the laboratory, the study found that the total population in 10 highland areas in 7 districts was 12,398 people who were lacking domestic water and predicted that the water demand by 2030 would be 1,823 m3/day. In addition, the study results showed that the exploitable underground water reserve was 14,748 m3/day, meeting the current and future water supply needs of the locality. In addition, the findings show that natural conditions have a strong impact on the stability of water resources because the area is located in a mountainous area, which creates complex water formation conditions, and irregular rainfall, flood and flow regimes. In addition, socio - economic conditions only have a low and medium impact on the stability of water resources because there has not been much investment in economic development in these areas, the population is sparse, the demand for water is low and the number of water exploitation works is not high. Therefore, the study has proposed a number of suitable water exploitation solutions to serve the domestic water supply for local people, ensuring economic development and limiting the current water scarcity.
This study examines the diurnal temperature variation in relation to Local Climate Zones (LCZs) in Hanoi, Vietnam, using a 20 - year time series (2004 – 2024) of MODIS Land Surface Temperature (LST) data. The use of MODIS imagery provides a consistent and reli able dataset for analyzing long - term urban thermal dynamics. LCZ classifications were derived from globally available datasets integrated within the Google Earth Engine (GEE) platform. Results reveal a significant warming trend during the daytime across al l LCZs. Notably, LCZs 1 to 8 , repr esenting highly urbanized areas, exhibit the most pronounced temperature increases, ranging from 2.3°C to 3.0°C over the study period. In contrast, nighttime temperatures show only a modest increase of approximately 0.18°C across all LCZ types, with limited variability between them. These findings underscore a growing daytime urban heat island (UHI) effect, particularly in densely built environments such as compact mid - rise zones. Areas with dense vegetation exhibit the lea st temperature rise, highlighting the moderating influence of green cover. Overall, the study emphasizes the critical role of urban form and land cover in shaping spatial patterns of surface temperature variation, offering important insights for climate - re sponsive urban planning in rapidly developing cities like Hanoi.
Artykuł dotycz problemu wyboru właściwej metody pomiaru uziarnienia paliw węglowych przeznaczonych do naziemnego zgazo - wania w różnych typach reaktorów. Dokonano przeglądu technik pomiarowych wraz z określeniem uwarunkowań do ich stosowa - nia. Uziarnienie węgli przeznaczonych do zgazowania badano w klasach ziarnowych dostosowanych do odpowiednich technologii zgazowania. Wyniki analiz granulometrycznych poddano aproksymacji i ocenie statystycznej. Wykazano możliwości aplikacyjne dla dwóch standardowych metod: analizy sitowej – dla grubo uziarnionych węgli zgazowywanych w reaktorze ze złożem stałym, przesuwnym lub fluidalnym oraz dyfrakcji laserowej – dla drobno uziarnionych węgli zgazowywanych w technologiach z reaktorem strumieniowym.
As mining activities and productivity escalate, the 6kV power grid infrastructure of open-pit mines has become increasingly diverse in load types and structurally complex. Consequently, the demands placed on relay protection systems are progressively intensifying. Beyond merely ensuring operational safety, these systems are n ow required to enhance power supply reliability, thereby minimizing interruptions that could severely disrupt the production cycle. Notably, none of Vietnam's open-pit mines currently utilize directional Over-current relay (DORC) in their 6kV feeders. Beca use of including electric excavators, the power running to the fault point in 6kV PCC node could come from two direction causing the wrong operating of over-current relays Thus, the utilizing the directional protector is critically important for bolstering the reliability and efficiency of the power supply system in these mining operations. The devices automatically detect not only fauls current value but also their direction, then isolate the fault point after predefined delay. This mechanism significantly reduces the wrong tripping in 6kV grids from earthing as well as one-phase short-circuited, which account for over 80% of total faults MV grids of mines. This paper, through a study of the characteristics of medium-voltage grids with electric excavators a s distributed loads, proposes an effective directional relay application. The synchronization of setting parameters of multi-level DOCR (3levels) is also proposed, supported by thorough simulation and verified utilizing ETA and NEPLAN software, to prevent premature relay operations (false trips), which could lead to unnecessary power outages and prolonged supply interruptions. The integration of directional protector within the framework of overcurrent protection, combined with well-calibrated adjustments, will be validated with a specific 6kV power grid of a coal mine to demonstrate the feasibility and effectiveness of the proposal. The outcome setting values are customized with grids’ internal parameter to perform a discriminative tripping. These ones are also used to recommend their application across all medium-voltage grids in Vietnam's coal mines .
Artykuł dotycz problemu wyboru właściwej metody pomiaru uziarnienia paliw węglowych przeznaczonych do naziemnego zgazowania w różnych typach reaktorów. Dokonano przeglądu technik pomiarowych wraz z określeniem uwarunkowań do ich stosowania. Uziarnienie węgli przeznaczonych do zgazowania badano w klasach ziarnowych dostosowanych do odpowiednich technologii zgazowania. Wyniki analiz granulometrycznych poddano aproksymacji i ocenie statystycznej. Wykazano możliwości aplikacyjne dla dwóch standardowych metod: analizy sitowej – dla grubo uziarnionych węgli zgazowywanych w reaktorze ze złożem stałym, przesuwnym lub fluidalnym oraz dyfrakcji laserowej – dla drobno uziarnionych węgli zgazowywanych w technologiach z reaktorem strumieniowym.
The paper presents a study on the optimal design of ground geodetic networks using GNSS technology, focusing on baseline configuration and robustness analysis of the network under Vietnam’s field conditions. The main objective is to propose solutions for n etwork structuring and technical guidelines to enhance the stability and reliability of geodetic networks, minimize the impact of gross errors (outliers), and optimize surveying efficiency. The research methodology includes constructing a five - po int network with measurement data consisting of 11 angles and 8 baselines, applying the indirect adjustment model, calculating redundancy numbers, and analyzing robustness indices under specific scenarios of baseline supplementation. Experimental results s how that baselines II - IV and II - V play a key role, with very small redundancy numbers. When measured or supplemented, these baselines significantly improve the stability and reliability of the overall network adjustment. Robustness analysis further indicat es that supplementing baseline II - IV helps reduce the maximum robustness indices at critical points (particularly points III and V) substantially, while also distributing reliability more evenly across the network points. These findings highlight the impor tance of optimizing network structures based on the theory of redundancy and robustness, and provide clear practical guidelines to enhance quality control performance in real - world GNSS surveys. The research conclusions support survey engineers and measure ment organizations in selecting rational network structures, prioritizing the measurement or quality control of “backbone” baselines (with small redundancy numbers), in order to achieve both economic efficiency and high quality in ground geodetic projects .
Technologia spalania fluidalnego wytwarza popioły znacznie różniące się od powstających w kotłach konwencjonalnych. Główną cechą popiołów fluidalnych jest obecność w nich produktów odsiarczania spalin oraz niewykorzystanego sorbentu, w połączeniu ze znacznie odmiennym składem mineralogicznym glinokrzemianów wynikających ze znacznie niższej temperatury spalania. Popiół fluidalny ma wiele interesujących właściwości, z których najbardziej wybija się jego stosunkowo duża aktywność chemiczna. Podczas gdy wiele potencjalnie obiecujących obszarów zagospodarowania tych popiołów nadal czeka na rozwinięcie, wydaje się ważne, żeby – nadal składując znaczną ich ilości – pozostawiać sobie możliwości przyszłego odzysku i wykorzystania zeskładowanych popiołów, raport w końcowej części analizuje kilka takich możliwości podając wybrane przykłady. W podsumowaniu zwraca uwagę, iż dotychczasowe badania skupiały się na usuwaniu uciążliwości popiołów fluidalnych, zaś obecne i przyszłe dotyczą ich zastosowań surowcowych.
Geoheritage is crucial for comprehending the planet's history and the geological processes that form the basis of all landforms, geomorphological structures, and distinctive elements of geodiversity. The goal of geoeducation is to enhance community understanding and responsibility for the Earth's natural and cultural legacy. As a result, efforts to save the environment and natural resources are concentrated and encouraged.Hang Rai geoheritage in Nui Chua National Park, Ninh Thuan Province, Vietnam is suggested to have distinctive geological scientific significance at the national level, featuring tectonic sea cliffs and ancient coral terrace, along with ecological and aesthetic value. Despite being a well-known tourist destination, geoeducational activities have not been given the focus they deserve. A study was carried out to assess the geoeducation potential of Hang Rai geoheritage utilizing the GEOAM method. The investigation involved a survey of 12 specialists utilizing 8 criteria, concluding that the geoeducation potential of Hang Rai is at a high implementation level. Geoeducational values were also surveyed by the visitors with a simplified-GEOAM. 73 responses were collected and analyzed using a multivariate linear model in BMA. A model that accounts for 80.3% of the variance in y (r2 = 0.803) with the lowest BIC (Bayesian Information Criterion) was chosen the most suitable model for predicting the relationship between geoeducation value and three variables, including: interactive and hands-on activities (EEI3), community benefits (CIE1), outreach and communication (CIE2). This serves as a foundation for the development of geoeducational programs tailored for various tourist groups in Nui Chua National Park specifically and Vietnam's geoheritages broadly, ultimately enhancing community awareness regarding the management and conservation of natural resources in pursuit of sustainable development.
The study aims to determine the characteristics of microplastics (MPs), including their abundance and shape, in surface sediment samples at Can Gio Beach, Ho Chi Minh City, Vietnam. Well - established methods, such as organic matter digestion, density separation, sample filtration, and microscopic observation, were utilized. Surface sediment samples were collected in April 2023 along two transects perpendicular to the shoreline (from sample CG - 1 (at low tide) to sample CG - 5 (at the highest tide)) and along t o the shoreline (from sample CG - 6 to sample CG - 9). The results indicate that, perpendicular to the shoreline, the average microplastic abundance is 6.28 ± 0.16 items/g. Microplastic abundance tends to increase towards the shore, with the highest abundance at sample CG - 5 (17.97 items/g) and the lowest at CG - 1 (0.46 items/g). Microplastic shape includes fragments, fibers, foams, and films, with fragments comprising the highest proportion at 74.46%. Along the shoreline, the average microplastic abundance reach es 21.60 items/g. The results of the analysis of the relationship between MPs and sediment particle size showed that MPs were concentrated in the “medium sand”, “coarse sand” and “very coarse sand” types. Thus, the abundance of MPs along the shoreline is h igher than that to the offshore.
Vetiver grass (Vetiveria zizanioides or Chrysopogon zizanioides) is a versatile tropical plant widely recognized for its applications in environmental protection and natural disaster mitigation. In Vietnam, where natural disasters such as floods and landslides are frequent, particularly along highways, Vetiver grass has proven to be an effective bioengineering solution. This paper provides a comprehensive review of the applications and benefits of Vetiver grass in preventing soil erosion and stabilizing slopes along Vietnam’s transportation systems. A bibliometric analysis of 555 Scopus-indexed publications (2000 – 2024) was conducted using VOSviewer software to identify research trends, key themes, and knowledge gaps. The findings emphasize the significant environmental and economic benefits of Vetiver grass, including its ability to enhance soil stability, control erosion, and treat polluted environments. Case studies in Vietnam further demonstrate its successful integration into slope stabilization projects, riverbank reinforcement, and flood mitigation strategies. The paper advocates for the broader adoption of Vetiver grass in sustainable infrastructure development and disaster risk reduction, while identifying future research directions to expand its applications.
It is our great pleasure to present the 9th World Multidisciplinary Congress on Earth and Environmental Sciences (WMCEES 2025), taking place in the city of Ostrava, Czech Republic, from 8 to 12 September 2025. This volume, published within “Inżynieria Mineralna, Journal of the Polish Mineral Engineering Society”, captures the spirit of a distinguished international meeting that continues to stand for innovation, collaboration, and excellence in the field of Earth Sciences. WMCEES 2025 aims to offer a dynamic and inclusive environment for the presentation of the latest discoveries, research developments, and technological innovations in Earth Sciences. The congress encourages active scientific dialogue and the building of lasting partnerships among experts from a wide range of disciplines. It also welcomes the contribution of early-career researchers, providing them with valuable opportunities to share their work, exchange ideas, and connect with leading professionals in an atmosphere of openness and mutual learning. Now in its ninth annual edition, WMCEES continues to fulfill its mission of advancing multidisciplinary research in Earth Sciences and strengthening collaboration among scientists worldwide. The 2025 congress stands as a testament to the diversity of studies presented, highlighting recent findings and capturing new perspectives on the functioning of Earth systems and humanity’s place within them. Our sincere appreciation goes to the distinguished members of the Scientific Committee and the Institutional Scientific Partners of WMCEES 2025. Selected from respected and accomplished experts representing many countries, their knowledge, dedication, and guidance have been essential in shaping the scientific quality and overall success of this congress. All objectives of WMCEES 2025 have been successfully achieved, resulting in the publication of 48 peer-reviewed articles that reflect the diversity and depth of research presented during the congress. We sincerely thank all reviewers for their careful work and commitment, which ensured the high scientific standard of every contribution included in this volume. We extend special thanks to the sponsors of WMCEES 2025, with the main sponsors LAMA Energy and LAMA Solar. We also gratefully acknowledge the contribution of 3GON Positioning, TINES, Ostrava Info, and Sevcik Transport, whose cooperation and support have been instrumental in the realization and success of this congress. Our sincere appreciation goes to all participants from different countries whose enthusiasm and contributions have enriched WMCEES 2025. Their active involvement and exchange of ideas created a truly international atmosphere of collaboration and discovery. We also wish to acknowledge the dedication of the WMCEES 2025 organizing team, whose commitment and professionalism were essential to the success of the event. As editors of WMCEES 2025, we would like to convey our deepest gratitude to everyone who contributed to the preparation and realization of this congress. It is our honor to present these proceedings as a reflection of the continuing mission of WMCEES to advance multidisciplinary knowledge and innovation in Earth Sciences.
This study examines and refines non-traditional heating approaches based on the integration of heat pump technology with renewable energy sources. A critical analysis of both existing implementations and proposed designs of energy-efficient heating systems has been conducted, emphasizing the potential for performance improvement through hybrid configurations. A novel solution is proposed involving the incorporation of solar collectors and thermal accumulators into a heat pump-based heating system, enabling efficient utilization of solar energy as a supplementary heat source. An algorithmic framework and a set of analytical expressions have been developed to determine the optimal values of key design parameters, including the effective surface area of the solar collector and the volume of the thermal accumulator. These parameters serve as the foundation for calculating the core thermodynamic and operational characteristics of the proposed hybrid system. To ensure the technical soundness of the solution, a mathematical model has been constructed to simulate thermodynamic and heat-exchange processes within the hybrid configuration. An automated calculation procedure has been implemented to support system design and parameter optimization, allowing for robust performance assessments under varying operational conditions. The simulation and analytical results confirm that the proposed hybrid heat pump heating scheme achieves up to 1.5 times greater energy efficiency compared to conventional ground-source heat pump systems. The findings substantiate the rationality of integrating renewable sources into heat pump systems and demonstrate a viable pathway for enhancing energy performance in sustainable building heating applications.
The article presents an analysis of the thermal conductivity coefficient determined using three methods. One is based on data taken from the literature, while the other is based on the results obtained from field thermal response tests. Third one is something between this two. The analysis covers the results obtained for five different boreholes of varying depths, in which seals with increased conductivity and different trade names were used. In one location, gravel with a grain size of 8 mm to 16 mm was used as a seal. Each of the boreholes has a different location, which is also related to different geological structures.
