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3D geological model of the Paleogene deposits in bauxitebearing district Snižnica (Posušje, BiH): from visualization to finding new bauxite deposits
No full textOne of the economically most valuable bauxite deposits in the Adriatic Carbonate Platform (AdCP) originates from the terrestrial phase between the Upper Cretaceous and Paleogene. The bauxites formed during Upper Cretaceous–Paleogene emersion are present on the entire AdCP. One of the largest and most explored and exploited area is the bauxite-bearing area of Posušje in Bosnia and Herzegovina. Geological exploration and exploitation were continuous and intensive between 1950 and 1990, but after that, all works were stopped by war. In the last ten years, research has started again, and exploitation has been stable with a tendency to increase. This work results from the new research combined with old data collected by Rudnici Boksita d.o.o. Posušje. Footwall to the bauxite deposits are thick Cretaceous rudist limestones, and the hanging-wall is composed of diverse carbonate and clastic sediments of the Paleogene age. This work aimed to collect all available data, systematize them into a 3D geodatabase and construct a 3D geological model of Paleogene strata in Snižnica locality, one of the most complex districts in the area. This work results in a new geological map, 15 geological cross-sections, and a 3D geological model of the Paleogene strata. The 3D model shows the spatial distribution of different Paleogene lithofacies, and the thickness of Paleogene deposits, which is important for drilling planning and reconstruction of eroded parts of the Paleogene deposits. The thickness of Paleogene deposits ranges from 0 to almost 200 m, while the eroded part of Paleogene deposits reaches up to 100 m. The 3D geological model also indicates that the largest amount and largest deposits are located under the clastic series of deposits, especially if the eroded part is taken into account. The constructed 3D geological model and the conducted analysis can serve as a basis for planning further exploration works, primarily drill-holes to find new bauxite deposits
Razvoj prototipa kondenzacijskog higrometra za precizno određivanje točke rosišta zraka : završni rad
No full textU ovom radu detaljno su prikazani izgradnja i testiranja prototipa kondenzacijskog higrometra za određivanje točke rosišta zraka na principu hlađenja reflektirajuće aluminijske pločice termoelektričnim generatorom, a njegovo hlađenje vršeno je regulacijom temperature preko razvojne pločice Arduino. Cilj izgradnje kondenzacijskog higrometra visoke točnosti je dobivanje točne vlažnosti u svrhu umjeravanja ostalih instrumenata pa zbog toga kondezacijski higrometri imaju visoku cjenovnu vrijednost. Rezultatima testiranja je utvrđeno da bi se uz dodatne kalibracije senzora dobivali podatci visoke točnosti
Movement of energy prices during the European energy crisis in 2022 : master's thesis
No full textU ovom radu nastojalo se prikazati i dokumentirati kretanje cijena energenata u Europskoj uniji u svjetlu najveće geopolitičke krize u Europi od Drugog svjetskog rata, a koja je ujedno rezultirala i energetskom krizom. Analiziran je rast cijena nafte, plina, električne energije i ugljena čije su cijene tijekom 2022. godine dosezale rekordne razine. Također, dan je i neizbježan osvrt na utjecaj rata u Ukrajini na kretanje cijena energenata u Europi, a koji je i ukazao na krhkost energetske sigurnosti Europe, te na ogromnu ovisnost Europe o ruskoj nafti i plinu. Rast cijena energenata izazvao je niz lančanih reakcija poput rasta cijena hrane, goriva, prijevoza, grijanja, inflaciju i recesiju u nizu europskih država i čime je znatno ugrožen i poljuljan standard europskih građana. Ono što bi se, nakon svih istraživanja i dostupnih podataka, moglo dati kao zaključak ovog rada jest da energetska kriza nije gotova i da je vrijeme jeftine energije u Europi prošlost.The thesis aimed to present and document the movement of energy prices within the European Union in light of the most consequential geopolitical crisis in Europe since World War II, which resulted in energy crisis. The analysis encompassed the escalation of oil, gas, electricity and coal prices, all of which reached unprecedented heights in the course of 2022. Furthermore, it offers an insight into the influence which the conflict in Ukraine had on the energy price dynamics in Europe, illuminating the vulnerability of Europe's energy security and its reliance on Russian oil and gas. The surge in energy prices set off a chain reaction, leading to elevated costs of food, fuel, transportation, heating, and also inflation and recession across various European nations. This substantially compromised and unsettled the quality of life for European citizens. Drawing upon exhaustive research and available data, the conclusion that can be drawn from this thesis is that the energy crisis persists, and the era of affordable energy in Europe has come to an end
Potential of secondary REE sources in Adria Region
No full textThe workshop "Rare Earth Elements value chain gaps and opportunities in the ADRIA region" is organized as part of the EIT project RECO2MAG - Novel grain boundaries engineered resource efficient Nd-Fe-B permanent magnets (financed by EIT KIC Raw Material)
Shock initiation and propagation of detonation in ANFO
No full textThe ammonium nitrate (AN) and fuel oil (FO) mixture known as ANFO is a typical representative of non-ideal explosives. In contrast to ideal explosives, the detonation behavior of ANFO exhibits a strong dependence on charge diameter, existence, and properties of confinement, with a large failure diameter and long distance required to establish steady-state detonation. In this study shock initiation and propagation of detonation in ANFO were studied experimentally by determining the detonation velocity at different distances from the initiation point, as well as by numerical modeling using AUTODYN hydrodynamics code and a Wood–Kirkwood detonation model incorporated into EXPLO5 thermochemical code. The run-to-steady-state detonation velocity distance was determined as a function of charge diameter, booster charge mass, and confinement. It was demonstrated that a Lee–Tarver ignition and growth reactive flow model with properly calibrated rate constants was capable of correctly ascertaining experimentally observed shock initiation behavior and propagation of detonation in ANFO, as well as the effects of charge diameter, booster mass, and confinement
Leached copper correlation with dissolved organic carbon in sloped vineyard soil
No full textThe solubility and mobility of copper (Cu) in soil is strongly influenced by the presence of dissolved organic carbon (DOC); however, the interactions between Cu and DOC are complex and not yet fully understood. In this study, Cu and DOC concentrations were measured monthly for two years in leachates from self-constructed lysimeters installed at inter- and intra-row vineyard hilltop, backslope, and footslope areas at the SUPREHILL Critical Zone Observatory, Croatia. The aim was to quantify Cu and DOC leaching from the hilltop towards the backslope and the footslope. The assumed strong relationship between Cu and DOC in the leachates was statistically analyzed and explained using chemical equilibrium software. Leachates were analyzed for pH, EC, DOC, Cu, and major ion concentrations. The highest Cu concentrations found in leachates from the intra-row footslope suggested Cu downhill transport. Although not strong, a significant positive correlation between Cu and DOC in footslope leachates confirmed the relevance of Cu complexation by DOC. Speciation confirmed that more than 99.9% of total Cu in leachates was found as a Cu-DOC complex. Data implied the role of soil water flow pathways in explaining Cu downhill transport. Critical timing for applying Cu fungicides at sloped vineyards was highlighted
Sedimentološke značajke aptsko-albskih naslaga kamenoloma Kanfanar, Istra
No full textU kamenolomu Kanfanar, u blizini istoimenog mjesta u zapadnom dijelu središnje Istre, izvrsno je otkriven istraženi dio aptsko–albskih naslaga s nekoliko emerzijskih površina, tj. diskordancija. Najznačajnija diskordancija predstavlja regionalnu emerziju i granicu između 2. i 3. megasekvencije naslaga Istre (TIŠLJAR et al., 2002). U okviru terenskog rada i istraživanja na području kamenoloma Kanfanar snimljen je, uzorkovan i opisan slijed naslaga debljine 20,85 m (slika 1). Na temelju mikroskopskih litoloških značajki i fosilnog sadržaja određena su četiri mikrofacijesa (MF1–MF4). Mikrofacithat fact, this landslide density map harmonizes historical landslide records on the national level and allows a quantitative measure of landslide spatial distribution which enables direct comparison of different regions. According to the analyses the zones with the highest landslide density are distinguished in areas around the cities of Virovitica, Krapina, Kravarsko, Zagreb, Samobor, and Požega. Still, it is important to point out that this map cannot provide estimates of landslide occurrences in the future. Therefore, this inventory and landslide density will be further used to estimate the geological units most susceptible to landslides and assess their geomorphological characteristics, which strongly influence landslide occurrence. jes MF1 obuhvaća mikritne vapnence (vekstone-pekstone) s bačinelama, dekastronemama, bentičkim foraminiferama, bioklastima, onkoidima i fragmentima školjkaša (većinom rudista) te ukazuje na okoliš potplimne zone niske energije vode. Na temelju prisutnosti navedenih fosila uzorci s prevladavajućim udjelom bačinela, onkoida i bioklasta čine podtip MF1a dok uzorci u kojima većinom prevladavaju bentičke foraminifere, dekastroneme, fragmenti ljuštura školjkaša i dazikladalne alge čine podtip MF1b. Mikrofacijes MF2 obuhvaća sitnozrnastije mikritne vapnence (većinom madstone do pekstone) s intraklastima, bioklastima, peloidima, bentičkim foraminiferama te ljušturama školjkaša čime ukazuje na okoliš potplimne zone povišene energije vode. Na temelju navedenih elemenata razlikujemo podtipove MF2a, u kojem prevladavaju intraklasti, bioklasti kao i bentičke foraminifere dok peloidne čestice, bentičke foraminifere te u manjoj mjeri bioklasti prevladavaju u podtipu MF2b. Mikrofacijes MF3 obuhvaća zrnastije tipove vapnenaca (većinom vekstone–pekstone uz neke grejnstone) s litoklastima, bioklastima, peloidima, bentičkim foraminiferama (miliolidama), dekastronemama i dazikladalnim algama čime ukazuje na okoliš plimne zone. Na temelju prisutnosti navedenih fosila u uzorcima izdvojen je podtip MF3a u kojem dominiraju litoklastične i bioklastične komponente; u MF3b prevladava prisutnost bentičkih foraminifera i peloida. Mikrofacijes MF4 predstavlja prijelaz iz morskog okoliša (plimne zone) u slatkovodni okoliš pa razlikujemo fenestralne vapnence (MF4a) s fragmentima ljuštura ostrakoda, fenestralnim šupljinama, bioturbacijama i foraminiferama; te haroficejske vapnence (MF4b) s dominantnom pojavom slatkovodnih haroficeja i ostrakoda. Mikrofosilna zajednica s vrstama Palorbitolina lenticularis, Praechrysalidina infracretacea, Voloshinoides murgensis, Pseudolituonella conica, Archaealveolina reicheli ukazuje na stariju aptsku starost donjeg dijela slijeda. Na oko 10 m slijeda nalazi se trošniji horizont karakteriziran brečiranim i okršenim vapnencima s udubljenjima ispunjenim glinovitim matriksom. Mikrofosilna zajednica u uzorcima neposredno ispod te emerzijske površine je mlađeaptske (npr. Salpingoporella dinarica, Protochrysalidina elongata, Rumanoloculina minima), a iznad mlađealbske starosti (npr. Pseudonummoloculina heimi, Sigmoilina? sp., Novalesia cf. Angulosa, Vercorsella cf. immaturata Cuneolina parva, Nezzazatinella picardi), ukazujući da je to glavna aptsko–albska diskordancija. Emerzijske površine sličnih značajki nalaze se i na oko 14 m te 16,5 m slijeda mlađeg alba. Istraživani slijed naslaga ukazuje na relativno oplićavanje taložnih okoliša tijekom apta i uspostavljanje kopnenih uvjeta i nastanka paleotla na prijelazu apt–alb. Slijed alba u krovini paleotla karakteriziran je oscilirajućom transgresijom na koju ukazuju brojne emerzijske površine
Long-term analysis of soil water regime and nitrate dynamics at agricultural experimental site: Field-scale monitoring and numerical modeling using HYDRUS-1D
No full textIntensive agricultural practices increase agrochemical pollution, particularly nitrogen (N) based fertilizers, which present an environmental risk. This study aims to evaluate long-term (2009–2020) data on soil water regime and nitrate dynamics at an agricultural experimental site on fine-textured soils and to better understand the implications of N management in relation to groundwater pollution. The field site is located in the Biđ field (eastern Croatia), in the proximity of the Sava river. Zero-tension lysimeters were installed at six selected locations. Lysimeters were used to monitor the water regime, i.e., outflows in which nitrate concentration was measured, while additional soil-water samples were collected via 4 and 15-meter-deep monitoring wells. Soil hydraulic parameters were estimated by combining the laboratory measurements, and estimation in RETC software. Water regime and nitrate leaching in lysimeters were simulated using HYDRUS-1D for each year to allow crop rotation and to evaluate their effects individually. The HYDRUS-1D model successfully reproduced lysimeter outflows and nitrate dynamics, which was confirmed with high R2 values (water: 93% above 0.7, and nitrate: 73% above 0.7) indicating the good performance of the model simulating nitrification chain reactions. Principal component analysis (PCA) was performed to identify the relationships among all soil properties and environmental characteristics. The results showed the complex interaction of soil hydraulic properties, precipitation patterns, plant uptake, and N application. All locations have a decreasing trend of nitrate leaching over the investigation period. Most of the lysimeter outflows and elevated nitrate concentrations were connected to the wet period of the year when the soil was saturated, and evapotranspiration was low. The results of this study show that it is important to optimize N fertilizer applications for each particular environmental condition to reduce nitrate loss. The study indicates the importance of long-term field studies, key for agro-hydrological modeling and the improvement of agricultural practices
q−spherical surfaces in Euclidean space
No full textIn this paper we define q-spherical surfaces as the surfaces that contain the absolute conic of the Euclidean space as a q-fold curve. Particular attention is paid to the surfaces with singular points of the highest order. Two classes of such surfaces, with one and two n-fold points, are discussed in detail. We study their properties, give their algebraic equations and visualize them with the program Mathematica