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This paper discusses the problem of the accumulation of solid materials and water in deep mine sumps, which negatively affects the safety and efficiency of sumps operation. The proposed solution is the implementation of two-stage pump-hydroelevator systems. The research is based on theoretical modeling, empirical analysis, and experimental testing using methods of hydrodynamic modeling and energy consumption calculations. The results showed that automating the processes of cleaning and pumping water reduces the number of accidents by 50-80%, shortens the time personnel spends in hazardous zones by 70-90%, and allows for operation at depths of up to 200 meters. The implementation of the systems also increases the lifespan of pumps by 1.5–2 times and reduces maintenance costs. Automated systems enhance the safety and efficiency of mine operations, ensuring the stable operation of sumps.

Remote sensing has proven to be effective for mapping natural water bodies; however, its application in analyzing the physicochemical properties of mining sumps, particularly for detecting acid mine drainage (AMD), remains underexplored. This study evaluates the use of reflectance spectroscopy combined with multispectral PlanetScope SuperDove imagery to provide a practical solution for AMD detection and spatial mapping in coal mine sumps. Nine water samples from active sumps in the Asam-Asam coal mine, South Kalimantan, Indonesia, were analyzed for their physicochemical properties and spectral reflectance. Positive correlations between visible spectrum absorption band depths and concentrations of SO₄²⁻, Fe(tot), and Mn(tot) were identified, enabling the spatial mapping of AMD sources. Spatial mapping revealed areas of persistent AMD contamination, particularly during dry seasons when water coverage was reduced, leading to concentrated pollutant levels. Temporal analysis of the imagery revealed seasonal fluctuations in water coverage and AMD intensity, influenced by rainfall and mining activities. These findings underscore the utility of integrating spectral and spatial data to monitor AMD dynamics. This integrated approach bridges the gap between detailed laboratory analyses and large-scale environmental monitoring, providing a cost-effective tool for early AMD detection and supports sustainable mining practices through improved environmental monitoring.

Sustainable development, urban planning, mobility, and transport planning, integrated within the context of sustainable urban mobility, have been central themes in both scientific and applied spheres over the past few decades. In port cities, it becomes particularly essential to tackle sustainability issues given the pollution and noise emanating from ships and other port-related activities. To meet mobility and transportation sustainability needs in the port area, a port should implement measures aligned with a sustainable urban mobility planning (SUMP) approach. However, many ports have thus far achieved limited results in this direction due to the absence of an approach to defining sustainable mobility solutions based on the SUMP approach for an urban area associated with the given port. The overall aim of this paper is to support the development of territorial SUMP for port areas by proposing a methodology that identifies and prioritizes sustainable mobility solutions tailored to a specific port area. The proposed methodology is applied in the Port of Bar (Montenegro) through an appropriate case study. In this case study, the methodological steps are systematically followed, resulting in the practical implementation of the selected mobility solution: the use of a hybrid bus for internal employee transportation within the port area. The undertaken case study underscores the simplicity, practical applicability, and adaptability of the proposed methodology.

Like any other turbomachinery, it is essential that the hydraulic behavior and performance of mixed-flow pumps are evaluated way in advance prior to manufacturing. Pump performance relies heavily on the proper design of the intake structure. Intake structures should be accurately designed in order to minimize and avoid unnecessary swirl and vortex formations. Ensuring the optimum performance condition as well as predicting how a particular intake structure affects the efficiency of the pump often requires either physical model studies or theoretical evaluations. Unfortunately, physical models are costly, time-consuming, and site-specific. Conversely, design and performance predictions using a theoretical approach merely gives performance values or parameters, which are usually unable to determine the root cause of poor pump performance. This study evaluates the viability of using Computational Fluid Dynamics (CFD) as an alternative tool for pump designers and engineers in evaluating pump performance. A procedure for conducting CFD simulations to verify pump characteristics such as head, efficiency, and flow as an aid for preliminary pump design is presented. Afterwards, a multiphase simulation using the VOF approach is applied to compare the fluid dynamics between four different pump intake structures. A full-sized CFD model of the pump sump complete with the pump’s active components was used for the intake structure analysis in order to avoid scaling issues encountered during the reduced-scale physical model test. The results provided a clear illustration of the hydraulic phenomena and characteristic curves of the pump. A performance drop in terms of reduction in TDH was predicted across the various intake structure designs. The CFD simulation of intake structure provided a clear insight on the varying degree of swirl, flow circulation, and effect on pump efficiency between all four cases.

To study the impact of roof-attached vortex (RAV) evolution on pressure fluctuations in a pump sump, an experiment was conducted using highspeed visualization and pressure measurement. The results indicate that the RAV evolution progresses through four stages: inception, development, formation, and dissipation. The expansion of the RAV cavity is proportional to the flow rate. At low flow rates, a single spiral vortex is produced, whereas high flow rates result in a symmetrical secondary vortex double spiral. A low frequency of 0.42 Hz characterizes the RAV-induced pressure fluctuations and exhibits a nonlinear low-frequency broadband nature, with the energy density ranging from 0 to 250 Hz in the time-frequency spectrum.

Present work was carried out to investigate the measurement accuracy of the sump depth for 7050 billet in direct chill (DC) casting process. Three measuring methods were applied: (i) Al-30wt.% Cu melt was poured into the mold at the steady state of the casting attempting to record the profile of billet sump; (ii) two steel rods were vertically dipped into the centreline and the edge of the billet attempting to measure the distances between the solidus and the free liquid surface in the hot-top; (iii) several ordered thermocouples were pre-arranged onto the starting block and they were solidified into the billet as it was cast, and a series of temperature-time curves was recorded after casting. For the purposes of comparison and evaluation, a numerical model based on the same experiment parameters was also built and the simulation results were compared with measured results by above methods. It indicates that the sump depth measured by thermocouples has the best consistency with numerical results. The most accurate method is temperature recoding by thermocouples. The Al-Cu melt pouring method is more accurate than the rods dipping method, and the sump depths measured by later two methods were the positions about the solid fraction (fs) depths of 0.8 to 0.9.

Urban areas constitute one of the main issues of sustainability as defined by the United Nations with the Sustainable Development Goals (SDGs). The recent smart city concept represents a way for achieving the urban sustainability goals. The European Commission (EC) bases the smart city concept on three pillars: energy, transport and Information and Communication Technologies (ICT). The main objective of the paper is to investigate the European smart city process, by focusing on urban mobility and their interconnections with the other two pillars. The methodological approach of territorial planning is used by identifying the plan dimensions and then analyzing the processes at master and sectorial level. The applied processes are verified with a review of the European documents that constitute the rules for defining and implementing the smart city concept. European guidelines indicate the SUMP as the integrated master plan that contributes to reach the convergence among energy, transport and ICT processes. By focusing on people mobility sector, European cities are implementing the Mobility as a Service (MaaS) plan at the sectorial level. This implies the necessity to enhance the knowledge of mobility phenomenon, in relation to emerging ICT and their impact on energy consumptions. The contribution of the work is given by the identification of a planning and implementation path focused on smart city, in urban areas, which connects the general goals of Agenda 2030 with the daily implications for citizens and therefore with the specific results. The paper results are useful: from one side, for researchers that work on advancements of theories, and from another side, for planners and decision makers to explore the European attempts towards urban sustainability and the real implementations on urban mobility systems.

When planning their transport policy, cities usually focus on developing sustainable transport systems and reducing the negative consequences of transport. One way to deliver transport policies is to use the Sustainable Urban Mobility Plan (SUMP), a strategic document designed to meet the demand for mobility whilst ensuring adequate quality of life for the residents. The process of Sustainable Urban Mobility Planning (SUMP process) can be supported by using a transport model. The objective of this article is to analyse the efficacy of the Multilevel Model of Transport Systems—referred to by its acronym, MST—for the SUMP process. With its ability to represent the transport system’s behaviour depending on the level of detail, the MST can significantly benefit the SUMP process. The proposed concept of integration of the MST into the SUMP process has already been tested and applied in delivering Gdynia’s (Poland) SUMP. The paper suggests ways to use the MST at different levels of planning and modelling and describes the outcomes. Using the multilevel structure helps to fully realise the transport model’s potential to improve the effectiveness of urban mobility planning. The conclusions show that the methods proposed in the article are worthwhile and cities should consider them when planning the SUMP process.

The smart city concept is being viewed as part of the urban future, integrating technological advances, multi-sectorial collaboration, and innovative open markets with strategic goals and ambitions to achieve sustainable urban development. Smart mobility is considered a vital element of the smart city, given that urban transport systems should become more efficient and sustainable. With this in mind, we raise the question: how sustainable is smart mobility? To answer this, we review smart city strategies and measures of fourteen mid-sized cities of the Nordic Smart Cities Network, identifying smart mobility goals together with proposed or implemented mobility measures. We evaluate how they align with sustainable mobility and how effective they are with the help of two analytical frameworks: a) the EU’s Sustainable Urban Mobility Planning (SUMP) objectives and b) the S.M.A.R.T. objectives. In doing so, we assess to which degree smart mobility strategies and measures in Nordic smart cities contribute to sustainable urban mobility and development, and how they contribute to achieving sustainable and smart city goals in terms of feasibility and accountability. The study reveals that measures mainly address the SUMP objectives relating to efficiency and environment, with little focus on inclusive and safe mobility planning that caters to attractive cities and high quality of urban life. Another finding is that smart mobility measures are relatively conventional, and their goals and ambitions are often stated on an abstract level and rarely measurable with specific indicators. Thus, there seems to be a lack of feasibility and accountability related to smart mobility measures, as well as a lack of focus on social sustainability.