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Stanje opažačkih bušotina za podzemnu vodu: primjeri iz Zagreba i okolice
No full textU ovome radu prikazani su primjeri namjernog i nenamjernog oštećenja opažačkih bušotina za podzemnu vodu
Projecting CO2 emissions in Eastern Croatia for the purpose of determining incentives for the deployment of CCS technology
No full textCilj rada je ubrzavanje primjene tehnologije hvatanja i skladištenja CO2 (CCS) kroz definiranje sustava poticaja po toni uhvaćenog CO2 na primjeru istočne hrvatske. U radu su projicirane cijene emisijskih jedinica prema tri linearna scenarija rasta. Također, iz zakonskog akta preuzete su količine emisijskih jedinica koje se planiraju prodati na dražbama. Dio prihoda od prodaje emisijskih jedinica alociran je određeni broj godina u novo osnovani CCS fond uz pretpostavku četiri različite veličine fonda, a koji će se koristiti za isplaćivanje poticaja emiterima za hvatanje CO2 u trajanju od 10 godina. U svrhu određivanja točnog iznosa poticaja, projicirane su CO2 emisije za četiri emitera primjenom geometrijskog Brownovog gibanja u Pythonu: NEXE (cementni sektor), DS Smith Belišće (sektor papirnih proizvoda) te UNI VIRIDAS i TE-TO Osijek (termo-elektrane toplane). Postavljena je gornja granica za iznos poticaja koja iznosi 80 EUR/t. Rezultati su optimistični budući da iznosi poticaja za najvećeg emitera (NEXE) variraju između 8 i 81 EUR/t. Najmanji iznos poticaja za ostale emitere iznosi 20 EUR/t, dok se gornja granica od 80 EUR/t postiže pri većim veličinama CCS fonda. Gotovo 60 % izračunatih iznosa poticaja za manje emitere rezultira vrijednostima iznad graničnih, što predstavlja priliku za stvaranje CCS klastera u istočnoj Hrvatskoj, odnosno mogućnost poticanja više emitera istovremeno. To bi omogućilo emiterima stvaranje i korištenje zajedničke transportno-skladišne infrastrukture, uz istovremeno smanjenje troškova cjelokupnog CCS vrijednosnog lanca.The aim of the work is to accelerate the deployment of carbon capture and storage technology (CCS) through the definition of an incentive system per ton of captured CO2 by using eastern Croatia as an example. The emission allowance prices are forecasted according to three linear growth scenarios. Also, the quantities of emission allowances that are planned to be sold at auctions were taken from the legal act. Part of the income from the sale of emission allowances is allocated for a certain number of years in the newly established CCS fund, assuming four different fund sizes, which will then be used to pay incentives to emitters for capturing CO2 for a period of 10 years. In order to determine the exact amount of incentives, CO2 emissions were forecasted for four emitters using geometric Brownian motion in Python: NEXE (cement sector), DS Smith Belišće (paper & pulp sector) and UNI VIRIDAS and TE-TO Osijek (thermal power plants). An upper limit has been set for the incentive amount, which is 80 EUR/t. The results are optimistic since the incentive amount for the largest emitter (NEXE) varies between 8 and 81 EUR/t. The minimum amount of incentives for other emitters is 20 EUR/t, while the upper limit of 80 EUR/t is reached for larger sizes of the CCS fund. Almost 60% of the calculated incentive amounts for smaller emitters result in values above the upper limit, which represents an opportunity to create a CCS cluster in eastern Croatia, that is, the possibility of incentivizing more emitters at the same time. This would allow emitters to create and use a common transport-storage infrastructure, while simultaneously reducing the costs of the entire CCS value chain
One-step electrochemical synthesis of PEDOT based composites for supercapacitor applications
No full textThe aim of this work was to determine the optimal synthesis conditions for the preparation of a poly(3,4-ethylenedioxythiophene) (PEDOT) layer by the electrochemical method from an electrolyte containing graphene oxide (GO) and a sodium dodecylsulfate (SDS) micellar solution. Besides an SDS anion, GO is also incorporated within the PEDOT layer as a negative counter ion. Therefore, this is a one-step electrochemical method for a PEDOT/GO composite layer preparation. The results displayed that PEDOT composites were successfully synthesised by applying a potential in the value range from 0.94 to 1.00 V, and with a synthesis duration of up to 600 s. It was concluded that the optimal concentration of EDOT monomer is 0.02 mol dm-3, and SDS 0.01 mol dm-3. The incorporation of GO into the PEDOT layer improved the polymer response in KCl solution influencing the pseudocapacitive properties, which is significant for its supercapacitor applications. The morphological and structural properties of the obtained layers were characterized by means of scanning electron microscopy and ultraviolet-visible spectrophotometry. The pseudocapacitive properties were determined in a 0.1 mol dm-3 KCl solution by using cyclic voltammetry and electrochemical impedance spectroscopy methods
Gornjotrijaski litofacijesi na lokalitetu Lokve u Gorskom kotaru – indikatori paleookolišnih i paleoklimatskih promjena
No full textThe Upper Triassic deposits in the entire Western Tethys realm are widely recognized in the form of the Main Dolomite (Hauptdolomit/Dolomia Principale). However, the lower part of the Upper Triassic is lithologically more diverse, and of variable thicknesses, sometimes even missing in the External Dinarides. It is represented by different lithofacies ranging from fine to coarse grained clastics, marls, limestones, dolomites as well as coal and bauxite occurrences. This heterogeneous lithology archives several palaeoclimatic events that punctuated the otherwise predominantly arid monsoonal regime of the Late Triassic. On such climatic episode in the lower part of the Carnian ( Julian 2–Tuvalian 2), is the Carnian Pluvial/Humid Episode (CPE, SIMMS & RUFFELL 1989; RUFFELL et al., 2016); a rather short episode of climatic change, indicated by a shift from arid to relatively more humid conditions, an enhanced hydrological cycling, and increased weathering intensity linked to global carbon cycle perturbations triggered by large-scale volcanism (e.g., DAL CORSO et al., 2020). The CPE is distinguished in the sedimentary record as a period of intensive weathering and clastic influx into the marine realm, paralleled by a reduced carbonate deposition, as well as coal or bauxite accumulation on land. The aim of this research was to identify this climatic episode in the Lokve section, Gorski Kotar area, in the External/ Karst Dinarides with the help of petrography, clay mineral analysis and palynology. In this area, the Upper Triassic strata directly lays on Permian siliciclastics (SAVIĆ & DOZET, 1983). The recorded Upper Triassic succession is composed of sandstones, followed by an interval of red shale and dolomite intercalations, as well as grey shales between dolomite layers, and finally well-bedded dolomites in its uppermost part. Sandstones are determined as feldspar arenites to greywackes. They are composed of angular to rounded clasts and exhibit good sorting. The matrix is composed of clay minerals which are cemented by calcite. The shales are irregularly laminated, with very dispersed irregular dark laminae. Only rare quartz silt-size clasts are observed. Dolomites are mostly primary with well-preserved textures and alochem fabrics. Four types of dolomites are determined: dolomicrite, dolobiomicrite, dolobiosparite and dolobiolitite. XRD analysis of shales and sandstones showed a general increase in micaceous and clay minerals, coupled with a decrease in albite, hematite, and quartz along the section. Among the clay minerals only chlorite was distinguished, but no kaolinite was recognized. The increase in carbonate sedimentation is interpreted as stabilization of the sedimentary environments, and cessation of siliciclastic input. Decrease in grains size of clastic component up section indicates more quiet environments and possibly more distal position on the stabilized shelf. The increase in clay sized particles is also related to the increase in micaceous minerals, and consequently to the decrease in quartz content. Although K-feldspar and plagioclase were recognized in XRD analysis, the lack of kaolinite, as a weathering product of such minerals indicates the climatic conditions were not humid tropical but rather warm arid. Change in shale colour, from red to grey is related to the reduction of iron, as the red clastic bare hematite, and in the grey shales pyrite is recognized. The “Carnian Pluvial Episode” sediments have some similar characteristics with the recorded Lokve section, but clear evidence for such an episode is not seen here. The Lokve section probably represents a younger Upper Triassic stratigraphic interval, representing the stabilization of carbonate production and deposition of the regionally recognized Main Dolomite
Granica perm–trijas na Velebitu: nova facijesna, biostratigrafska i kemostratigrafska obilježja
No full textThe Permian–Triassic boundary (PTB), one of the most investigated stratigraphic boundaries, is marked by dramatic changes in oceanic and atmospheric chemistry that consequently caused the most severe mass extinction of all time. These changes can be seen in the type and style of deposition in the PTB interval that is characterized by transition from skeletal-dominated to microbial-dominated carbonate production. Most of the studies concerning this important time interval have been made in shallow to deep marine depositional environments in addition to some terrestrial sections. However, there is very little information about how shallow lagoonal, sabkha and intertidal sediments reacted to these drastic changes. Indeed, shallow marine deposition was often prone to dolomitization and thus difficult to date. In the Brušane-Sy section located south of the village Brušane (Velebit Mountains) in the External Dinarides (Croatia), we have observed continuous dolostone sedimentation throughout the Permian- Triassic boundary interval and obtained new facies, bio- and chemostratigraphic data (conodonts, foraminifers, δ13C curve). A high-resolution micropetrographic study shows different dolostone texture and preservation of primary constituents in the Permian vs. the Early Triassic dolostone. The Permian dolostone deposits are differentiated as: 1) dolomicrite/mudstone with microbial (cyanobacterial) interlayers, the occurrences of stromatactoid fabric, desiccation cracks/tepee structures signifying deposition in intertidal/supratidal conditions; and 2) dolobiomicrite/wackestone and dolobiomicrite/packstone microfacies types with fairly preserved abundant calcareous algae and their spores (acritarchs), foraminifers (Hemigordiopsids with some Nodosariids and Fusulinids), gastropods, bivalves and ostracods that were deposited in the subtidal low energy zone of a shallow lagoon. Primary structures of the Permian dolostone show well-preserved fabric due to favourable dolomitizing conditions, i.e., primary dolomitization. However, significant appearances of dissolution voids indicate diagenesis in the meteoric/ marine vadose zone. The presence of the vadose sediment features is not likely for the sabkha-dolomitizing conditions under arid climate conditions usually related to this type of dolomitization. The inf luence of microbial activity should rather be taken into consideration for interpreting the intense dolomitizing process. On the contrary, the Triassic dolostone, whose age is confirmed by finding of the conodont species Hindeodus parvus for the first time in the PTB interval of the Velebit Mts., exhibits a completely different dolostone texture in comparison to the Permian microcrystalline dolomite type. Early Triassic dolostone strata conformably overlie Late Permian dolostone deposits and exhibit medium- to coarse crystalline unimodal planar-s type texture, possibly indicating exceptional aftermath dolomitizing conditions (shallow burial-like) and the influence of microbial and decaying organisms to the formation of the coarse crystalline dolomite texture. The δ13C values do not represent the global oceanic signal but either depict the values of a restricted basin or were influenced by the early dolomitization. Moreover, the meteoric diagenesis subsequently overprinted this signal
Procjena podložnosti na klizanje za primjenu u sustavu prostornog planiranja: od državnog do lokalnog mjerila
No full textThe main motivation to research the landslide susceptibility assessment for application in land use planning arises from the national landslide risk assessment (BERNAT GAZIBARA et al., 2019) which recognised landslides as a second natural risk in Croatia (CNPDRR, 2019). Furthermore, the preliminary regional landslide susceptibility analysis showed that approx. 20 % of the Republic of Croatia area is potentially prone to sliding. Therefore, landslide susceptibility assessment for national, county and local levels was carried out in the frame of two scientific projects Methodology development for landslide susceptibility assessment for land-use planning based on LiDAR technology (LandSlidePlan, HRZZ IP-2019-04-9900) (BERNAT GAZIBARA et al., 2022) and project Applied landslide research for the development of risk mitigation and prevention measures (PRI-MJER, KK.05.1.1.02.0020). The national landslide susceptibility map at a small scale is created to give a general overview of critical areas for an entire country, and its purpose is to inform policymakers and the general public (MIHALIĆ ARBANAS et al., 2022). County-level landslide susceptibility assessment on a medium scale synthesizes available data and identifies wider areas with landslide problems and can be used to define areas for more detailed research on a local level. The third level is the local-scale landslide mapping and zonation that includes specific areas of local administrative units (municipality or city) or complex critical areas. The results were landslide susceptibility maps for seven study areas: (i) the Republic of Croatia; (ii) City of Zagreb, Karlovac County and Primorje–Gorski Kotar County; and (iii) the study areas in the Zagreb City (BERNAT GAZIBARA et al., 2023), Hrvatsko Zagorje (SINČIĆ et al., 2022a), Karlovac City (SINČIĆ et al., 2022b) and Istria. Methodology development for landslide susceptibility assessment on national and county scales was carried out using a heuristic approach, i.e. Fuzzy Logic method, and available topographical and geological data. Given that the validation of the final landslide susceptibility map is mandatory, and systematic landslide inventories at the national or county level do not exist, we used the landslide database conducted by the University of Zagreb, Faculty of Mining, Geology and Petroleum Engineering. The database consists of 2,186 landslides with the exact location of the occurrence. All landslide susceptibility maps showed high accuracy and were classified into three susceptibility zones, considering The Area Under the Receiver Operating Characteristic Curve (AUCROC). Methodology development for landslide susceptibility assessment on a local scale was carried out using different mapping units and statistical methods (e.g. Information Value method, Weights of Evidence method, Logistic Regression and Discriminant Analysis, and machine learning methods, including Support Vector Machine, Artificial Neural Network and Random Forest). Moreover, landslide susceptibility models were computed using different scenarios of high-resolution input data, i.e. geometrical types of LiDAR-based inventory and variations of causal factors. Finally, all landslide susceptibility models were evaluated based on model fitting performance, model prediction performance, and model uncertainty. The purpose of comparing landslide susceptibility models is to define the most suitable maps for application in spatial planning at national, regional, and local levels. The research was based on innovative technologies, limitations related to the availability of spatial data in Croatia (limited amount of geological data), and urgent needs for efficient solutions applicable in the Croatian spatial planning system in line with European and global requirements related to sustainable development, human and environmental protection
Development of open educational resources on permanent magnets and rare earth elements
No full textIn the frame of the EIT RawMaterials RECO2MAG project (https://reco2mag.rgf.bg.ac.rs/), which focus is on optimizing the manufacturing process of permanent magnet microstructures through novel grain boundary processing to produce resource-efficient sintered NdFeB PMs with lowered Dy content and improved energy products for use in novel electric motor designs, Open Educational Resources -OER (UNESCO, 2022) on permanent magnets and rare earth elements were developed. Firstly, syllabi for two online courses: (1) “Green Deal and Circular Economy Challenges of Rare Earthbased Permanent Magnets with Technical Aspects”, and (2) “Rare Earth Elements Value Chain Gaps and Opportunities in the ADRIA Region” were designed. The courses were aimed primarily at master’s and Ph.D. students, but also at researchers, policy-makers and raw material exploration and production experts worldwide, but with emphasis on RIS (Regional Innovation Scheme) countries, i.e. countries and regions in Europe where the pace of innovation is modest or moderate (https:// www.eitmanufacturing.eu/what-we-do/regional-innovation- scheme-ris/about-us/). Syllabi included: courses information (title, description, and instructor information); courses objectives, courses outlines (topics to be covered); course agenda; required materials; grading policy; and learning activities. Following the design of the syllabi, the online courses were successfully implemented in academic year 2022/23. Both courses had a shorter version consisting of six hours of lectures, panel discussions, and quizzes. Panel discussions and lectures were recorded. Successfully completed the long version of the course that included additional 24 hours of teamwork was awarded with one ECTS credit. For each course there were more than 100 applicants from more than 35 countries. Finally, short version of first and second workshop successfully passed 49 and 71 respectively. To ensure the courses’ sustainability, the learning materials and recorded lectures have been adapted as OER. These materials, including text, video, quizzes, and links to other open-source materials on the internet, are placed on the e-learning platform MoD (https:// mod.srce.hr/) using course design. MoD is an e-learning system based on the open-source Moodle software system established to support e-learning projects within the academic community. Copies of both e-courses have been placed in the Digital Academic Archives and Repositories (DABAR) of University of Zagreb Faculty of Mining, Geology and Petroleum Engineering (https://repozitorij. rgn.unizg.hr/) under the CC0 license. This type of Creative Commons licence implies that the contents are freely available to the public and can be accessed, reused, repurposed, adapted, and redistributed by anyone without any cost. The developed OER serve as a free and selfsustainable platform for the dissemination of knowledge gained during the project’s implementation
Field trip A2 – Red Istria : Western Istrian Anticline as an ideal natural laboratory for the study of the regional unconformities in carbonate rocks
No full textUtjecaj materijala obloge i promjera eksplozivnog punjenja na brzinu detonacije ANFO eksploziva : završni rad
No full textANFO eksplozivi se zbog svojih zadovoljavajućih minersko tehničkih i detonacijskih svojstava te relativno niske cijene najviše koriste za gospodarska miniranja u rudarstvu i graditeljstvu. Uz ekonomski čimbenik, sigurnost prilikom miniranja, jednostavnost proizvodnje na mjestu upotrebe i mogućnosti mehaniziranog punjenja bušotina dodatni su razlozi učestalosti upotrebe. Premda su minerska svojstva ANFO eksploziva dobro poznata zbog neidealne detonacije ANFO eksplozivi su predmet mnogobrojni istraživanja. U radu je dan prikaz utjecaja obloge i promjera detonacije na brzinu ANFO eksploziva te su provedene terenska ispitivanja s ciljem utvrđivanja utjecaja različitih metala obloge na izmjerenu brzinu detonacije
Sequence stratigraphy of the Pliocene–Pleistocene infill in the southern part of the Adriatic foredeep system
No full textThe evolution of the foreland basin sediments in the Adriatic (Messinian–Quaternary) foredeep system was controlled by the Meso and Neoalpine emersed chain. Croatia’s southern part of this system comprises the Palagruža Trough and South Adriatic Basin filled with marine clastic succession. Our study, in this area, aims to reconstruct the shelf-edge trajectories and sequence stratigraphy to describe the migration of the depositional systems. The study integrates published geological maps, well logs and reports, and 2D seismic sections. Mappable seismic facies are defined and correlated with sedimentological facies and depositional processes. Both, ascending and descending shelf-edge trajectories are defined. Ascending trajectories are associated with transgressive and highstand system tracts. Descending trajectories are associated with forced regression and the presence of extensive erosional surface on the shelf. Overall progradation characterizes Pliocene and Pleistocene sediments, first filling the Palagruža Trough in the SW direction and then SE progradation towards the South Adriatic Basin. The progradation pattern is interrupted by a base-level rise at the end of the Pliocene. Analysing the main sediment transport directions, the two third-order unconformity-bounded stratigraphic units are interpreted. Especially interesting are results about nearby Pliocene–Pleistocene clastic depositional systems and processes that shaped the southern part of the Adriatic Sea. These results highlight the stratigraphic and tectonic evolution of the Adriatic foredeep’s southern part, providing the records of the regional and global controls driven by the local tectonics and emersion, basin migration and subsequent basin infill