Papers by Andreja Sironić
Prirodna ravnotežna 14C aktivnost u atmosferskom ugljikovu dioksidu i u biosferi narušena je na g... more Prirodna ravnotežna 14C aktivnost u atmosferskom ugljikovu dioksidu i u biosferi narušena je na globalnoj razini ljudskom djelatnošću. Intenzivni termonuklearni atmosferski pokusi sredinom 20. stoljeća uzrokovali su naglo povišenje 14C aktivnosti u atmosferi na razinu gotovo dvostruko višu od prirodne, a nakon zabrane pokusa 14C aktivnost se smanjuje i danas je gotovo dosegla prirodnu ravnotežnu vrijednost. U ovom su radu prikazani rezultati praćenja 14C aktivnosti u atmosferskom CO2, godovima drveća i biološkim uzorcima na nekoliko karakterističnih lokacija na području Hrvatske i Slovenije. Globalne promjene 14C aktivnosti opažaju se i na “čistim” lokacijama u zaštićenim područjima. U urbanim sredinama opažaju se lokalni efekti sniženja 14C aktivnosti u atmosferi zbog povećanog izgaranja fosilnih goriva, što je posebno izraženo u zimskim mjesecima. U okolici nuklearne elektrane opaža se povišenje 14C aktivnosti u atmosferskom CO2 za vrijeme i neposredno nakon izmjene gorivih elemen...
Arheološki radovi i rasprave, 2021
An underwater survey was conducted in September of 2020 on several locations in Kaštela Bay, main... more An underwater survey was conducted in September of 2020 on several locations in Kaštela Bay, mainly around the area of Pantan near Trogir, with the aim of assessing the potential of these locations for more detailed investigations. The limited survey gave positive results, as the collected prehistoric and Roman material pointed to a great potential of specific locations for further archaeological research.
Water
The Zagreb aquifer is the main source of potable water for the inhabitants of the City of Zagreb ... more The Zagreb aquifer is the main source of potable water for the inhabitants of the City of Zagreb and Zagreb County. It presents a strategic water reserve protected by the Republic of Croatia. All previous studies related to the definition of the groundwater–surface interaction in the study area have been made based on the isotopic composition of the Sava River from the location of the Domovinski Most bridge, which is located downstream of most pumping well fields. In 2019, a new monitoring station was established at the Podsusedski Most bridge, at the entrance of the Sava River into the Zagreb aquifer, approximately 23 km upstream of the Domovinski Most bridge. Within this research, water isotope data (δ2H, δ18O, deuterium excess) from both Sava River and groundwater sites were used along with hydrologic data to examine the extent to which hydrologic conditions affect the isotope signature and whether the interaction between groundwater and the Sava River causes a change in the isot...
Food as fuel: How to determine amount of biogenic component in liquid fuels
Book of Abstracts of 1st international conference "Food & Climate Change", 2021
Changes of the geochemical parameters in water of the Plitvice Lakes over the past 30 years
Interlaboratorijske usporedbe aktivnosti organski vezanog tricija (OBT)
2017. godine bila je organizirana 4. interkomparacija za OBT na uzorku osusene trave. Trava je uz... more 2017. godine bila je organizirana 4. interkomparacija za OBT na uzorku osusene trave. Trava je uzorkovana u okolici Nuklearne elektrane Cernavoda u Rumunjskoj, osusena je i homogenizirana, te samljevena. 2018. godine organizirana je 5. interkomparacija na uzorku ribe (Micropterus salmoides) iz okolice Nuklearne elektrane Chalk River u Kanadi. Riba je liofilizirana, samljevena i homogenizirana. U oba slucaja se nije diskriminiralo između frakcija E-OBT i NE-OBT, odnosno, nije trebalo posebno provoditi pretpripremu uzorka. Zahtjev je bio da svaki laboratorij pripremu uzorka i mjerenje ponovi pet puta. Oba uzorka analizirana su na Institutu Jožef Stefan (IJS), Slovenija i na Institutu Ruđer Boskovic (IRB), Hrvatska. Metodu analize OBT-a u Laboratoriju za mjerenje niskih radioaktivnosti IRB-a tek treba optimizirati i validirati te su ove interkomparacije svojevrsni pokazatelj napretka. Laboratorij za tekocinskoscintilacijsko spektrometrijo na Odjelu za fiziku niskih i srednjih energija ...
Quaternary palaeoenvironmental records in secondary carbonate deposits from Croatian karst
Fizikalna istraživanja aktivnih i paleookolišnih procesa u jamama Dinarskog krša
Correlation of stable isotope composition of carbonate precipitated in the water under different conditions
Preparation and properties of copper(II) complexes with N, N-dimethyl- and N, N- diethylglycine
Najzanimljiviji spojevi bakra(II) su njegovi kompleksi s koordinacijskim brojem od 3 do 6, kao i ... more Najzanimljiviji spojevi bakra(II) su njegovi kompleksi s koordinacijskim brojem od 3 do 6, kao i oni s koordinacijskim brojem 7. U ovom diplomskom radu dan je pregled spojeva bakra koordinacijskih brojeva 4 i 5, te pregled okruženja atoma bakra(II) u bioloskim sustavima. Buduci da su u ovom radu preparirani spojevi analizirani uz pomoc FT IR spektroskopije dan je i pregled karakteristicnih IR vrpci funkcionalnih skupina slicnih spojeva u literaturi. Opisane su preparacije akvabis(N, N- dimetilglicinato-N, O)bakar(II) dihidrata i bis(N, N- dietilglicinato-N, O)bakra(II) i rezultati termogravimetrijskihodređivanja te je dano tumacenje vrpci IR spektara. Potonjem je kvalitativno određena topljivost i izmjerena gustoca metodom flotacije. Također, opisana je i priprava bezvodnog kompleksa bakra(II) s N, N- dimetilglicinom te mu je kvalitativno određena topljivost, ali dalje nije istraživan.
During archeological excavations in the Lower Cerovačka Cave (Mt. Velebit, Croatia), the test tre... more During archeological excavations in the Lower Cerovačka Cave (Mt. Velebit, Croatia), the test trench penetrated to a depth of 1.8 m. An undisturbed sequence of sediments was exposed. Considering that caves represent highly efficient sediment traps it was possible to recognize changes in the depositional mechanisms during the Pleistocene–Holocene period. Using the multiproxy approach, the mineralogical, petrographic, and biostratigraphic characterization of the cave sediments was performed. Facies analysis revealed several stages in the development of the clastic filling of cave channels. Allochthonous origin of the sediment was assumed. Sedimentation took place under various conditions from pronounced cold and dry climate during Pleistocene stages in the base of the profile, to humid periods with anthropogenic influence during the Holocene at the very top of the profile. Although traditionally these sediments were believed to be of a Pleistocene age, here for the first time a strati...
Carbon isotope composition in karst aquatic mosses and possibility of using it in tufa dating
Isotope composition and morphological and structural properties of freshwater calcium carbonate from the Plitvice Lakes (Croatia)
14C activity (a14C), δ13C and δ18O of freshwater carbonates precipitated in the waters of the Pli... more 14C activity (a14C), δ13C and δ18O of freshwater carbonates precipitated in the waters of the Plitvice Lakes, Croatia, were measured at different locations exhibiting different conditions of precipitation. In addition, structural and morphological properties of calcium carbonate precipitates were studied. X-ray diffraction indicated the calcite as the main fraction of the carbonates. For this study we collected 3 types of carbonates (CaCO3) precipitate in the water: 1) suspended CaCO3 precipitated in 4 sediment traps, 2-10 m below the surface in 3 lakes, 2) CaCO3 precipitated on porous plastic pads submerged in the water (surface water) at 7 locations with different water flow rates (0 to 0.7 m/s), and 3) surface lake sediments (top ~40 cm) at the bottom of 4 lakes. δ13Cof dissolved inorganic carbon (DIC) and δ18O of waters were also measured. Carbonates were collected in different seasons in period 2011 – 2013.a14C values showed different ranges for different types of carbonates. S...
Utjecaj klimatskih promjena i stanja u okolišu na biološki inducirano taloženje sedre i sedimentacijske procese u Plitvičkim jezerima
Radiocarbon, 2021
ABSTRACTKarst environments preserve some of the best archives of past climate, vegetation, hydrol... more ABSTRACTKarst environments preserve some of the best archives of past climate, vegetation, hydrology, anthropogenic impact, and landscape evolution providing that a reliable chronology can be established. Here we present an example of the system of the Plitvice Lakes (Dinaric karst, Croatia), which is characterized by intensive tufa and lake sediment formations. The radiocarbon dating method, combined with some other dating methods and various geochemical and isotope analyses, showed that the Plitvice Lakes system in the present form has existed for about 8000 years. Older tufa deposits were dated to warm interglacial periods. A long-term comprehensive multi-proxy study showed that all environmental compartments (atmosphere, various water bodies, soil, bedrock, DIC, terrestrial and aquatic biota, and of course various secondary carbonates) must be included in order to obtain trustworthy results.
Proceedings from the 6th Scientific Conference Methodology and Archaeometry
Methodology and Archaeometry (MetArh) is an annual scientific conference organized since 2013 by ... more Methodology and Archaeometry (MetArh) is an annual scientific conference organized since 2013 by the Department of Archaeology of the Faculty of Humanities and Social Sciences of the University of Zagreb, and the Croatian Archaeological Society. The goal of the conference is to entice interdisciplinarity, critical thinking, new insights and approaches as well as new theoretical frameworks in contemporary archaeological science. This, second edition of the conference Proceedings contains eight scientific papers from the 6th MetArh conference which was held at the Faculty of Humanities and Social Sciences of the University of Zagreb, from 6th - 7th of December 2018. Papers are focused on different aspects of archaeological methodology and archaeometry, including case studies from Croatia, Slovenia, Serbia, Greece and Russia. In order to create a volume of high scientific quality, each of the conference paper was reviewed in the peer review process in which the identity of both reviewers and authors, as well as their institutions, are respectfully concealed from both parties.
Absolute dating of artworks and cultural heritage objects is one of the most important issues in ... more Absolute dating of artworks and cultural heritage objects is one of the most important issues in art history studies and essential for evaluating original art objects, differentiating between originals and later imitations and/or frauds and recognizing subsequent repairs and restauration works. The radiocarbon dating (14C dating) method is one of the most well-known radiometric methods of absolute dating, which can be applied for dating materials of biogenic origin, such as wood, charcoal, bones, grains, paper, parchment, textile, etc. The range of 14C age determination spans from the 19th century up to ~60, 000 years in the past. Due to a very low natural 14C concentration the radiocarbon dating method requires special techniques for chemical preparation of samples and measurement of 14C. Particular care must be taken in sample collection and/or storage as well as during sample pre-treatment and chemical preparation. As a result of the measurement one obtains a so-called convention...
14C dating of the biogenic littoral rims on the Adriatic islands
The biogenic (algal) littoral rims grow at around mean sea-level (MSL) and may be preserved for m... more The biogenic (algal) littoral rims grow at around mean sea-level (MSL) and may be preserved for millennium when growing in rising sea-level environment. In order to reconstruct the relative sea-level change during the Late Holocene, algal littoral rims were collected from three islands in the Adriatic Sea, Croatia. On the particularly exposed sites on rocky coasts of islands Vis, Ravnik and Bisevo these littoral rims built by the coralline rhodophyte Lithophyllum byssoides can be found. The presence of thick and well-developed Lithophyllum rims, considered to be a precise (±10 cm) sea-level indicator, points directly to the rising sea-level environment. Biogenic rims were mapped and sampled for 14C dating during 2008-2010. Two 14C methods, LSC (benzene synthesis) and AMS were used for dating algal samples. 14C activity of the calcareous deposit of a recent coralline algae, Vis Island, showed a14C of 103.7 pMC indicating that algae used CO2 from the atmosphere (mean 14C activity of a...
Report on OBT inter-comparison from the Ruđer Bošković Institute, Croatia – procedure improvement
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Papers by Andreja Sironić