In this presentation, published experimental measurements of the soil water retention curve on coarse-grained soils at low an high suctions were discussed. Particular focus was on how the shape of the SWRC may be influenced by the particle size distribution and discussed within the context of grading entropy coordinates. Furthermore, a mathematical model routinely used by soil scientist to determine the SWRC on the basis of the particle size distribution was also presented. Such model uses a significant assumption related to the geometrical arrangement of particles which was questioned within the context of DEM data of spherical particle assemblies.

This presentation was an introduction to the work of a European project due to start in October 2023. It pertains the use of open-source codes for DEM simulations. The objective of the project is to significantly improve what can currently be achieved by DEM codes by order of magnitude gains from time- and space- scale techniques, realistic and vexperiemnatlly validated contact constitutive models, as well as normalisation, standarisation and enhancements related to DEM data-processing and visualisation. The presentation discussed these objectives in some detail, presented the likely management structure of the project and encouraged participants to join the network. Further details may be found at https://www.cost.eu/actions/CA22132/.
TECHNICAL ANNEX

Proposed by Lőrincz (1986), grading entropy not only accounts for all the information within a gradation curve, but also displays the entirety of a PSD as a single point on an entropy diagram, represented by two highly informative coordinates. Whilst the benefits of grading entropy over typical PSD descriptors is clear, the method has garnered little attention, particularly at the microscale. The analysis of particulate behaviors from a microscale perspective has been enhanced by the discrete element method (DEM), which enables the tracking of individual particle behaviors and, uniquely, the transmission of forces through soil fabric.
This presentation provided a brief explanation of the normalised entropy diagram (and grading entropy). The behaviors in the different zones of the normalised diagram were explained in the context of both physical (drained and undrained triaxial tests) and numerical data (discrete element simulations). These behaviors were discussed within the further context of microscale particle contact behaviors, known as soil fabric, in the major and minor principal stress/fabric directions. By doing so, this presentation provided a micromechanical basis for the behaviors associated with the normalised entropy diagram, indicating that that the fabric behaviors within granular materials can also be described.

Lajos Filep wrote a paper on „Sets of equal spheres” in „Vízügyi közlemények” (Publications in Hydrology) in 1937. He assumed that every particle of a given material is a sphere. The particles are equal spheres forming a packing. Their shapes are not changed, and no force plays a role in the packing. He considered connected sphere packings, in which the configurations of touching spheres at every sphere are congruent. He introduced the term „uniform sphere packing” for such sphere packings. He determined the possible uniform sphere packings when the configurations of touching spheres at every sphere lie in at most 3 consecutive parallel layers of spheres in the sphere packing. He calculated the densities of those uniform sphere packings, determined their minimum density, and gave explanation when they may occur in nature. We give an overview of Filep’s work.

The injection of CO₂ into deep geological formations and energy recovery from MGH reservoirs are associated with geomechanical issues, i.e., induced seismicity (IS) and dissociation-induced instability (DII), respectively. The evaluation of geomechanical issues have been initiated at Environmental Geotechnology Laboratory, Indian Institute of Technology Bombay, Mumbai, India, (for a virtual visit please click Environmental Geotechnology Laboratory) to facilitate comprehensive understanding of the IS and DII, and some studies related to CO₂ sequestration in the form of a SHARP Storage project (sharp-storage-act.eu and @sharp_co2 ). The CO₂ can also be utilized as a working fluid to extract geothermal energy from the Abandoned Oil and Gas Wells (AOGWs). With this in view, attempts are being made to establish the processes and mechanisms associated with DII in NGH and IS during CO₂ injection. In addition to this, possible research opportunities useful in the connection of energy development by utilizing CO₂ have been discussed in this talk.

Having reviewed the Hungarian wind and radiation conditions, using the European global radiation and wind maps available on the internet and based on the results of previous Hungarian research, the available domestic wind and solar energy potential will be estimated. Using simple cost recovery calculations, the possibilities of the wind power is analysed. We have calculated with 1850–2200 hours of sunshine, and 1000–1500 properly windy hours. The wind speed in winter is higher than in summer, and above 100 m height, it is stronger at night than during the day. Our country is one of the favourable regions of Europe from the point of available solar energy. According to our calculations, the new type of wind turbines optimized to the climate (e.g. Vestas V120-2,2 MW) can operate economically if the wind is above 6 m/s. Nevertheless, it is advisable to make detailed wind energy and cost-benefit estimations in case of 100–200 m rotor heights. The electricity produced in such a way (even if the waste part of the electricity can be sold very cheaply) covers the cost of the investment. The wind farms can be operated very economically under the right regulatory trading and energy take-up conditions. In a first approximation, the specific cost requirements for wind farms are lower than that is for solar power plants. Micro and little wind power station (<100 kW) can be operated economically above 5 m/s wind speed, so we do not suggest their use in Hungary. The two renewable energy sources, wind and solar energy complement each other well but they alone cannot ensure the energy supply of our country. Besides them, further traditional and renewable energy sources are necessary, and very important the close connection to the European electricity market as well as the energy-saving and the search for the new efficient energy sources. The goal of this paper is the presentation of the Hungarian meteorological condition from the point of view of renewable energy sources, but the creation of the economic and regulatory environment is the task of the decision-makers. Keywords: renewable energy; climate conditions; wind and solar energy; wind profiles; continental wind farms; Vestas wind turbine; investment calculation.

The energy source of solar and wind power plants is free of charge, but requires materials and produces waste. The utilization of "renewable energy" is reasonable, but not the best by taking into account the organic development and all factors. Reducing waste and material losses could be more important. The author developed a complex evaluation system included in a matrix to present the LCA effects. These indicators are:
1. land occupation – electricity produced during its lifetime.
2. determination of energy return on investments (eroi) and net energy gain (neg).
3. emissions (no_x, so₂, co₂) – environmental protection.
4. material requirements of power plant structures - installed specific masses for lifetime produced electricity (steel, copper, aluminum, plastic).
5. fuel consumption of power plants - compared to material consumption of other power plants.
6. critical materials and dependencies in europe
7. physical advantages and disadvantages of solar energy.

We present the importance of research on transport processes in different fields, ranging from soil to membrane transport. We present the results of our theoretical research, where the equations were solved using Maple 13. Lommel functions were used in the solution.
Keywords: convection, Lommel functions, Maple, transport processes

The first results of an automated, nonlinear parameter identification method, applicable for convex merit functions and relatively large measurement data set with repeated samples are presented. The confidence domain is topographically determined such that the parameter identification is based on a global bracketing procedure. Since bracketing is based discrete parameter values, the coincidence of solution of similar inverse problems of the repeated samples can be attained. A confidence domain accounts non-linearity since the contour of a non-linear, noise-free merit function is used instead of a contour of the linearized one but a method is needed to ‘measure’ its size. It is found that the main source of error is the drying out of the samples during the test.

Wind turbine of which the rotor has vertical axis and – as its special, main feature – its blades are practically flat plates. (Light and easy to manufacture.) These blades can also turn around their own, vertical axis. They can have any shape, but they should be symmetrical on their own axes. The turning movement of the blades are controlled by a mechanism so that the pressure of the wind is pushing continously these blades in the same sense of rotation of the rotor, exept only one point of the whole circular way of the rotor when there is no push (staying in wind direction).
It is much easier to reach a higher torque, higher power with this solution than with the largely used big wind turbine of wich the axis of rotor is horizontal.
In case of those, horizontal axis wind turbine – in order to increase the power – it is necessary to increase the length of their blades. (Longer blades. Only its one dimension can be increased. But it is not enough. You need higher column, stronger, heavier basement, higher costs, etc.)
In this proposed vertical axis turbine, where the blades are flate plates the surface is to be increased. The surface has two dimensions. So, in order to reach the same result as above, the whole size of the turbine is not needed to increase so much.
The column of the vertical axes turbine can not be fixed to the soil by ropes, because the blades of their rotor is turning close to their columns. That is why their columns and their basements should be so strong, heavy and expensive. While our proposed solution can be fixed by ropes and so it can be much lighter and cheaper to manufature.

The goal is to make an extension of the existing database of domestic municipal landfills. Partners include the Department of Energy Engineering of the BME, Naplopó Kft., Meteorology Department of ELTE and the ELKH Energetic Research Center of KFKI. The solar radiation intensity measurements and wind speed measurements are carried out at the municipal landfill of Pusztazámor. The measured data are compared with the interpolated data sets based on meteorological research station data.

In the field of the H₂ industry, education on hydrogen energy applications began in 2006, and our active research activities started in 2017 at Óbuda University. In a unique approach within the country, starting from the 2023/2024 academic year, we will be launching two vocational engineering programs to meet the industrial needs.
Our research has expanded from industrial applications to encompass the energy sector and transportation. Our research activities, industrial collaborations, and participation in grant projects involve various aspects related to hydrogen, including the installation of electrolysers, technical and economic analysis of hydrogen storage and utilization.

Many pollutants threaten our environment, with environmental damage caused by heavy metals putting a heavy burden on soil, plant, water, and air systems. All heavy metals can be said to occur naturally without anthropogenic interference. However, human impact often drastically alters the quantities of these substances, especially along industrial sites, mines and in densely populated areas. Naturally occurring levels can also be harmful in some cases. There is hardly a place on earth today where some form of human-induced pollution or a harmful process triggered by human activity cannot be detected.
For the above reasons, the determination of heavy metal concentrations was chosen because of the interest in the presence of heavy metals in the environment of the tailings spoil of the Mátraszentimre and Parádsasvár mines in the Mátra and the impact of this environment on the heavy metal content of local plants.
The soil samples were taken from an average 0-30 cm depth. Plant samples were also collected from common birch (Betula pendula) and common hornbeam (Carpinus betulus) in Mátraszentimre and from common birch and native beech (Fagus silvatica) in Parádsasvár. In Mátraszentimre, the two species were justified because only birches were available in the central, open part of the mound. In contrast, only hornbeams were available near the soil sampling points in the more forested outer part. The samples were prepared in a Milestone 1200 mega microwave shredder. The samples were analysed with a Jobin-Yvon Activa-M ICP-OES instrument.
The study aims to detect a correlation between the heavy metal content of the soil and the concentration of heavy metals in the plants and to obtain a picture of the heavy metal contamination of the pond and its surroundings.
In Mátraszentimre, the copper, lead and zinc concentration in the soil exceeds the limit values for the soil medium in the lagoon area at several points. It would be advisable to use a cost-effective method to prevent the leaching of contaminants from the tailings pond. Such a solution could be rainwater drainage and trenching.
A correlation was also found between the concentrations measured in soil and plant samples for zinc, manganese and aluminium. Further studies are needed to clarify the relationships found. Parádsasvár: The investigations revealed that the material from the Peace reservoir in Parádsasvár is a potential source of contamination to the environment. However, no significant concentrations of heavy metals were measured in the water discharged from the mine, suggesting that the heavy metals detected are not in water-soluble form. Further investigation is needed to determine the form of the compounds, which is not a simple task.
In the plant samples, concentrations above 400 mg/kg have been measured mainly in zinc. This value could be toxic to plants, although this could not be confirmed based on field observations. None of the plant species tested accumulated lead, cadmium, and chromium. Although the soil concentrations would have justified this, these three heavy metals are likely present in the soil in insoluble form, although further studies are needed to support this hypothesis.
In evaluating the metal concentrations in the soil samples, limit values were exceeded at several sampling points by Joint Decree 6/2009 (IV. 14.) of the Ministry of Agriculture, Forestry, Environment and Water Management. The analysis of heavy metals cadmium, copper, lead and zinc detected multiple exceedances of the limit values. Based on the results of these measurements, it is recommended that the tailings pile be recultivated as soon as possible. Removal of the tailings is not sufficient. Further measurements would also be needed to determine the mass of metal-contaminated soil carried by the leachate to downstream areas, and to investigate the extent to which the reservoir downstream, about 1 km away, could be contaminated, as fish in the water could accumulate contaminants. Determining the extent of the spread is important because the soil sample with the highest cadmium concentrations is located immediately adjacent to the stream, and the water is already washing the lower layers of the vomit, which generally had higher heavy metal concentrations than the other layers.

Preliminary research investigates permeability–grading curve relationships for granular materials. Several permeability-grading curve relations were tested employing either traditional d-type grading curve parameters, or non-normalised grading entropy coordinates, or the combinations of these, always with density information. Some existing granular databases for saturated permeability have been re-evaluated by completing for the fines. In turn, permeability ranges not covered by existing databases have been explored by means of new additional experiments. Interestingly, when the permeability-grading curve relations were based on both variable sets and on the higher power of the void ratio (including the solid volume ratio formula e/(1+e)), the fit quality (using R²) was the best.