Flood damages assessment – case study

The article deals with the resolution of the problem of managing flood risk with the aim of effective management focusing on reducing flood risks and thus increasing the measure of flood protection. It is elaborated in the sense of currently valid Slovak legislation in the field of flood protection, primarily according to the Directive 2007/60/EC on the assessment and management of flood risks. Assessment of potential flood damage is carried out for the town of Medzev, which was in the scope of preliminary assessment of flood risk in Slovakia evaluated as an area with an existing potentially significant risk of flood. Given the preliminary results, we can state that in the studied location of Medzev the construction of flood protection measures makes sense, mainly in relation to the protection of property

Reservoir Management by Reducing Evaporation Using Floating Photovoltaic System: A Case Study of Lake Nasser, Egypt

Copyright: © 2021 by the authors. The shortage of water is a major obstruction to the social and economic development of many countries, including Egypt. Therefore, there is an urgent need to properly manage water resources to achieve optimum water use. One way of saving available water resources is to reduce evaporation that leads to the loss of a large amount of water from reservoirs and open lakes. This paper aims to use a floating photovoltaic system (FPVS) to cover a lake’s water surface to reduce evaporation and also for energy production. This methodology was applied to Lake Nasser as one of the largest lakes in the world where much evaporation happens due to its large area, arid environments, and the shallow depths of some parts of the lake. The estimated evaporation from the lake was 12.0 × 109 m3/year. The results show that covering 25%, 50%, 75%, and 100% of the lake can save about 2.1, 4.2, 6.3, 7.0, and 8.4 × 109 m3/year and produce energy of 2.85 × 109, 5.67 × 109, 8.54 × 109, and 11.38 × 109 MWh/year, respectively. Covering areas of shallow water depth was more efficient and economical. The results show that covering 15% of the lake’s area (depths from 0.0 to 3.0 m) can save 2.66 × 109 m3/year and produce 1.7 MWh/year. Covering 25% of the lake’s area (depths from 0.0 to 7.0) can save 3.5 × 109 m3/year and produce 2.854 MWh/year. Using an FPVS to cover parts of Lake Nasser could help manage water resources and energy production for Egypt to overcome the likely shortage of water resources due to population growth. This system could be applied in different locations of the world which could help in increasing water resources and energy production, especially in arid and semi-arid regionsThis work was supported by the projects of the Ministry of Education of the Slovak Republic, VEGA 1/0217/19: Research of Hybrid Blue and Green Infrastructure as Active Elements of a Sponge City, VEGA 1/0308/20: Mitigation of hydrological hazards—floods and droughts—by exploring extreme hydroclimatic phenomena in river basins, and the project of the Slovak Research and Development Agency APVV‐18‐0360: Active hybrid infrastructure towards a sponge city

Magnetic and structural studies into the effect of solvent exchange process in metal-organic framework MOF-76(Gd)

Effect of solvent exchange/absence on magnetic and structural properties of microporous metal-organic framework MOF-76(Gd) has been performed. Three compounds have been prepared and characterized: as synthesized MOF-76(Gd)-DMF, which containing DMF (N,N'-dimethylformamide) and H₂O molecules in the cavity system, activated complex without solvents, MOF-76(Gd) and water exchanged sample MOF-76(Gd)-H₂O. The structural study showed that compounds undergo structural changes after activation/exchange processes. Changes were mainly observed in the magnetic properties and distances between Gd...Gd ions: 4.718 Å for MOF-76(Gd)-DMF, 4.326 Å for MOF-76(Gd)-H₂O and 4.296 Å for MOF-76(Gd). The magnetic properties of the samples were studied by magnetic susceptibility χ_{M}(T) and magnetization M(H). The low positive value of the Weiss constant, Θ = 1.54 K in compound MOF-76(Gd)-DMF shows on a very weak ferromagnetic interaction. On the contrary, the negative values of Θ in complexes MOF-76(Gd) (-5.58 K) and MOF-76(Gd)-H₂O (-6.23 K) confirm the existence of antiferromagnetic exchange interaction between Gd(III) ions

A model based on dimensional analysis for prediction of nitrogen and phosphorus concentrations at the river station Ižkovce, Slovakia

The aim of this paper is to develop a model for pollutant concentration prediction in a stream. The developed model that determines nitrogen and phosphorus concentrations in a river is based on a dimensional analysis. Application of dimensional analysis to water quality modelling is presented, pointing out possibilities of applying this methodology in water quality research. We investigate how dimensional analysis can be applied to water quality modelling and which benefits it can bring to researchers in this area. For modelling water quality in a water stream it is essential to know the parameters that influence water quality. The relevant parameters are flow of water in the river (discharge), its catchment area, velocity of water in the stream, temperature of water, temperature of air and measured concentrations of the pollutant – nitrogen and phosphorus. A sensitivity analysis shows that the concentration of pollutant in water stream is sensitive to changes in both water and air temperatures. The model performs well when average values are used; the prediction error increases when the single concentration values are considered. The model was developed, calibrated and evaluated using measured data from the river station Ižkovce, River Laborec in eastern Slovakia

An Extensive Study for a Wide Utilization of Green Architecture Parameters in Built Environment Based on Genetic Schemes

Recently, green structures turned into a huge path to an economic future. Green building outlines include finding the harmony between agreeable home living and a maintainable environment. Furthermore, the usage of modern technologies is seen as part of greener construction changes to make the urban environment more viable. This paper introduces an exhaustive state-of-art review and current practices to look for the ideal green arrangement’s models, procedures, and parameters utilizing the genetic algorithms innovations to help for settling on the most ideal choice from various options. The integrated Genetic Algorithm (GA) along with the Nondominated Sorting Genetic Algorithm strategy GA-NSGA-II is considered to be more accurate for predicting a viable future. The above methodology is widely relevant for its humility, ease of execution, and enormous durability. Besides other approaches, the GA was incorporated as well as the Neural Network (NN), Simulated Annealing (SA), Fuzzy Set theory, decision-making multicriteria, and multi-objective programming. The most fashionable methods are moderately the embedded GA-NSGA-II approaches. This paper gives an outline of the capability of GA-based MOO in supporting the advancement of methodologies of the techniques and parameters to find the best solution for the building decision-making cycle. The GA combined schemes can fulfill all the requirements for finding the optimality in the case of multi-objective problem-solving

Superferromagnetism in chain-like Fe@SiO2Fe@SiO_2 nanoparticle ensembles

One-dimensional (1D) chain-like nanocomposites, created by ensembles of nanoparticles of with diameter ∼ 13 nm, which are composed of an iron core (∼4 nm) and a silica protective layer, were prepared by a self-assembly process. Chain-like Fe@SiO2 ensembles were formed due to strong magnetic dipole–dipole interactions between individual Fe nanoparticles and the subsequent fixation of the Fe particles by the SiO2 layers. X-ray near edge absorption spectra measurements at the Fe K absorption edge confirm that the presence of a silica layer prevents the oxidation of the magnetic Fe core. Strong magnetic interactions between Fe cores lead to long-range ordering of magnetic moments, and the nanoparticle ensembles exhibit superferromagnetic characteristics demonstrated by a broad blocking Zero-field cooling (ZFC)/field-cooling distribution, nearly constant temperature dependence of ZFC magnetization, and non-zero coercivity at room temperature. Low room-temperature coercivity and the presence of electrically insulating SiO2 shells surrounding the Fe core make the studied samples suitable candidates for microelectronic applications

Structure and Magnetic Properties of Three-Dimensional Gadolinium-Based Hybrid Framework

In the present work we have focused on the preparation and magnetic study of coordination polymer formed by Gd(III) cations as nodes and formate (HCOO¯; FOR) anions as charge compensating linkers. The prepared complex with formula ${[Gd(μ_{3}-FOR)_{3}]}_{n}$ was characterized by single-crystal X-ray diffraction, and high-energy powder X-ray diffraction. The structural study showed that complex is formed by 3D polymeric network with the shortest Gd-Gd, distances of 3.998 Å. The magnetic properties of the complex were studied by magnetic susceptibility $χ_{M}(T)$ and magnetization M(H) measurements. The results show on the weak antiferromagnetic coupling at low temperatures represented by the Weiss constant θ=-0.468 K. The value of effective magnetic moment $μ_{eff}=7.57μ_{B}$, which was estimated from the experimental data is close to the theoretical value for systems with S=7/2. Correlation between crystal structure of complexes and magnetic properties is presented

Assessing the Impact of Groundwater Extraction on the Performance of Fractured Concrete Subsurface Dam in Controlling Seawater Intrusion in Coastal Aquifers

Among the well-known approaches for controlling seawater intrusion during extensive freshwater abstraction from coastal aquifers is the construction of subsurface dams. In the current research, the SEAWAT code is being implemented to examine the impact of groundwater extraction on the effectiveness of a damaged subsurface dam for controlling saltwater intrusion. Simulations were performed numerically to check impact of the subsurface dam height, dam location, well height, well location, abstraction rate, fracture aperture, fracture location, seawater density and fracture dimension on the effectiveness of subsurface dam as a countermeasure to prevent saltwater intrusion in coastal aquifers. Increasing the abstraction rate from 1 × 10−6 to 5 × 10−6 m3/s caused the seawater to advance more into the freshwater, and the loss of effectiveness increased. The minimum and maximum value of loss of subsurface dam effectiveness was recorded to be 34.6% to 93%, respectively, for the abstraction rates from the well equal 1 × 10−6 and 5 × 10−6 m3/s, consequentially. When the dimensionless value of well height location Lw/Ld is increased from 1.0 to 2.0, the effectiveness of the subsurface dam is reduced by around 20%. The findings demonstrate that the well location, well depth, abstraction rate, location of the dam, fracture aperture, and density of saltwater all affect the effectiveness impairment of the fractured subsurface dam for controlling saltwater intrusion. Decision makers could use findings of this research to better manage groundwater resources in coastal aquifers

Superferromagnetism in chain-like Fe@SiO 2

One-dimensional (1D) chain-like nanocomposites, created by ensembles of nanoparticles of with diameter ∼ 13 nm, which are composed of an iron core (∼4 nm) and a silica protective layer, were prepared by a self-assembly process. Chain-like Fe@SiO2 ensembles were formed due to strong magnetic dipole–dipole interactions between individual Fe nanoparticles and the subsequent fixation of the Fe particles by the SiO2 layers. X-ray near edge absorption spectra measurements at the Fe K absorption edge confirm that the presence of a silica layer prevents the oxidation of the magnetic Fe core. Strong magnetic interactions between Fe cores lead to long-range ordering of magnetic moments, and the nanoparticle ensembles exhibit superferromagnetic characteristics demonstrated by a broad blocking Zero-field cooling (ZFC)/field-cooling distribution, nearly constant temperature dependence of ZFC magnetization, and non-zero coercivity at room temperature. Low room-temperature coercivity and the presence of electrically insulating SiO2 shells surrounding the Fe core make the studied samples suitable candidates for microelectronic applications

Numerical Investigation for Riverbank Filtration Sustainability Considering Climatic Changes in Arid and Semi-Arid Regions; Case Study of RBF Site at Embaba, Nile Delta, Egypt

Changes in riverine hydrography and reduced aquifer recharge due to projected climate changes in arid and semi-arid regions are the main issues of water supply, especially in the Nile Delta, Egypt. Continuous degradation results from reduced Nile water flow, poor management of groundwater extraction, and human activities throughout the Nile’s course and drainage channels. Contamination of this water with heavy metals and dissolved organic solids reduces the quality of this water, which increases the price of treatment. River Bank Filtration (RBF) is a water treatment technology used for improving the quality of drinking water taken from polluted rivers where abstraction wells are installed on the banks. This study was applied to the RBF site at Embaba, Nile Delta, Egypt using the numerical code MT3D. The study was simulated and calibrated for the current situation and number of scenarios to investigate the effect of climatic changes on RBF sustainability. Four scenarios were simulated to identify and estimate the RBF portion and the total water travel time from the river to the wells. The first scenario involves a reduction in river stages, the second a decrease in aquifer recharge, the third a combination of the first two scenarios, and the fourth scenario combines scenarios 1, 2, and 3. The results indicate that the RBF portion decreased from 67.42% in the base case to 35.46% and 64.99% with a reduction in river stage by 75% from the base case and a decrease in aquifer recharge from 182.50 (base case) to 50 mm per year, respectively. Moreover, the RBF portion increased to reach 87.75% with a reduction in the General Head Boundary of 75% from the base case, while the combination of the three scenarios decreased the RBF portion to 67.24%. Finally, the water supply systems in arid and semi-arid regions should be extended by installing and operating RBF facilities to manage the negative effects of climatic change through reduction in river stages and aquifer recharge, and increasing abstraction due to overpopulation