Riemannov tenzor zakrivljenosti

U ovom radu prvo navodimo neka svojstva regularnih ploha u $\mathbb{R}^3$, kao što je pojam Riemannovog tenzora definiran na tim plohama, i navodimo dokaz Gaussovog Veličanstvenog teorema. Nakon toga navodimo osnove diferencijalnih mnogostrukosti uključujući i pojam Riemannove metrike. Zatim obradujemo pojam Riemannovih mnogostrukosti i proučavamo neka njihova svojstva.In this thesis we first recall some properties of the regular surfaces in $\mathbb{R}^3$, like the notion of the Riemann tensor of this surfaces and present a proof of the Gauss’s Theorema Egregium. Afterwards we present basics of Differential manifolds including a concept of the Riemannian metric on. Then we elaborate the notion of a Riemannian manifolds and study some of its properties

Riemannov tenzor zakrivljenosti

U ovom radu prvo navodimo neka svojstva regularnih ploha u $\mathbb{R}^3$, kao što je pojam Riemannovog tenzora definiran na tim plohama, i navodimo dokaz Gaussovog Veličanstvenog teorema. Nakon toga navodimo osnove diferencijalnih mnogostrukosti uključujući i pojam Riemannove metrike. Zatim obradujemo pojam Riemannovih mnogostrukosti i proučavamo neka njihova svojstva.In this thesis we first recall some properties of the regular surfaces in $\mathbb{R}^3$, like the notion of the Riemann tensor of this surfaces and present a proof of the Gauss’s Theorema Egregium. Afterwards we present basics of Differential manifolds including a concept of the Riemannian metric on. Then we elaborate the notion of a Riemannian manifolds and study some of its properties

The influence of pyrolysis conditions on hydrocarbons composition of the shale oil (Aleksinac oil shale, Serbia)

The amount and the composition of liquid hydrocarbons (HCs) obtained by pyrolysis of oil shale depend on kerogen type, as well as pyrolytic system and conditions [1]. The aim of this study was to compare HCs composition of bitumen isolated from raw oil shale samples (osh) and shale oils obtained by pyrolysis of oil shales in an open system (os) and close system (cs) (Table 1). Investigation has been made on immature outcrop oil shale samples (vitrinite reflectance of 0.41 % Rr) from the Aleksinac deposit (Serbia). Pyrolysis experiments were performed on the two selected samples, which have shown the highest quantity of total organic carbon (TOC > 13 %) and high HCs generation potential (Hydrogen Index, HI > 615 mg HCs/g TOC) in the studied sample set [2]. The HCs composition of the shale oils obtained by open system pyrolysis indicates low maturity. They are similar to distributions of HCs in bitumens isolated from raw (initial) oil shales (Table 1). Therefore open system pyrolysis can be useful for assessment of source and depositional environment of organic matter. On the other head, shale oils obtained by pyrolysis in the close system have distributions of HCs which correspond to higher maturity and they are similar to composition of HCs in crude oil, generated in early stage of “oil window” (Table 1). Therefore, for artificial generation of shale oil (from immature oil shale), having composition comparable to crude oil, the close system pyrolysis is required. CPI – Carbon Preference Index, calculated from distributions of n-alkanes; Rc – calculated vitrinite reflectance = 0.49 x C29ααα20S/20R + 0.33; / – Not determined due to the absence of C29 αββ 20Rsterane in these samples

Geochemical and Sedimentation History of Neogene Lacustrine Sediments from the Valjevo-Mionica Basin (Serbia)

Valjevo-Mionica Basin is one of the numerous lacustrine Neogene basins in Serbia. After Aleksinac Basin, according to the quality and amount of oil shale, it is one of the main deposits of this raw material in Serbia. The most important oil shale deposits in Valjevo- Mionica Basin are located in the central part of the basin (Bela stena series, Sušeočka and Radobićka Bela Stena). The kerogen content in oil shales ranged from 8 - 16 %. The average oil yield of 6.3 % is of economical value. Total of 62 samples of Neogene lacustrine sedimentary rocks to the depth of 400 m were investigated in this study. The first objective of the study was to reconstruct geological history (evolution) of the sediments i.e. to determine the palaeoconditions in depositional environment during its formation. For this purpose numerous geochemical methods and approaches were used. The second objective of the study was to determine the origin, type, maturity and liquid hydrocarbon potential of organic matter (OM). Aimed at detailed estimation of the oil shale OM potential, and prediction of the conditions necessary to become active oil generating source rock, pyrolytic experiments were performed on the bitumen-free sample. Bearing in mind that some metal ions (e.g. Al(III)-ion in clay minerals) (Jovančićević et al., 1993; Peters et al., 2005) have catalytic influence on most of the maturation processes, and that Pt(IV)- and Ru(III)- ions are often components of catalysts in many laboratory investigations and industrial procedures (Hu et al., 1994; Kawaguchi et al., 2005), the pyrolytic experiments of bitumen-free rock were performed also in the presence of simple inorganic compounds, H2[PtCl6] and RuCl3, to investigate if their presence changes the yield and hydrocarbon composition of liquid pyrolysates

Geochemical and Sedimentation History of Neogene Lacustrine Sediments from the Valjevo-Mionica Basin (Serbia)

Valjevo-Mionica Basin is one of the numerous lacustrine Neogene basins in Serbia. After Aleksinac Basin, according to the quality and amount of oil shale, it is one of the main deposits of this raw material in Serbia. The most important oil shale deposits in Valjevo- Mionica Basin are located in the central part of the basin (Bela stena series, Sušeočka and Radobićka Bela Stena). The kerogen content in oil shales ranged from 8 - 16 %. The average oil yield of 6.3 % is of economical value. Total of 62 samples of Neogene lacustrine sedimentary rocks to the depth of 400 m were investigated in this study. The first objective of the study was to reconstruct geological history (evolution) of the sediments i.e. to determine the palaeoconditions in depositional environment during its formation. For this purpose numerous geochemical methods and approaches were used. The second objective of the study was to determine the origin, type, maturity and liquid hydrocarbon potential of organic matter (OM). Aimed at detailed estimation of the oil shale OM potential, and prediction of the conditions necessary to become active oil generating source rock, pyrolytic experiments were performed on the bitumen-free sample. Bearing in mind that some metal ions (e.g. Al(III)-ion in clay minerals) (Jovančićević et al., 1993; Peters et al., 2005) have catalytic influence on most of the maturation processes, and that Pt(IV)- and Ru(III)- ions are often components of catalysts in many laboratory investigations and industrial procedures (Hu et al., 1994; Kawaguchi et al., 2005), the pyrolytic experiments of bitumen-free rock were performed also in the presence of simple inorganic compounds, H2[PtCl6] and RuCl3, to investigate if their presence changes the yield and hydrocarbon composition of liquid pyrolysates

Traganje za izvornim stenama nafti depresije Drmno, južni deo Panonskog basena, Srbija

In a search for source rocks of the crude oils of the Drmno depression (Southern part of the Pannonian Basin, Serbia), based on bulk and specific organic geochemical parameters, six out of eight Sirakovo, Bubusinac and Bradarac sedimentary core samples were found to possess typical source rock characteristics. By comparing the results observed for these sedimentary samples with the corresponding propel-ties of the crude oils from the Sirakovo and Bradarac oil-gas fields, a positive organic geochemical oil-source rock correlation was experienced for the first time within this basin. This finding may be considered as an important step towards the ultimate organic geochemical/geological interpretation of the Drmno depression.Ispitivani su sedimenti iz bušotina koje pripadaju lokacijama Sirakovo Bubušinac i Bradarac (depresija Drmno). Primenjene su organsko-geohemijske metode (određivanje sadržaja organskog ugljenika, bitumena i ugljovodonika, kao i određivanje raspodele i obilnosti bioloških markera tipa n-alkana izoprenoidnih alifatičnih alkana, triterpana i sterana) sa ciljem da se proceni njihova naftna potencijalnost. Za šest uzoraka utvrđen je visok stepen maturisanosti organske supstance, pripadnost "oil generation" fazi (Rr = 0,70 – 0,80 %), tercijarna starost i pretežno terestrijalno poreklo. Poređenjem sa sirovim naftama iz već otkrivenih naftnih ležišta bliskog lokaliteta (Sirakovo i Bradarac) utvrđena je značajna sličnost i prema maturisanosti i prema poreklu, na osnovu čega je između ispitivanih uzoraka sedimenata i nafti, prvi put kada je u pitanju depresija Drmno, definisana pozitivna korelacija nafta-izvorna stena

Исследование напряженно-деформированного состояния нелинейных участков магистрального газопровода Карталы-Астана

A petrological and organic geochemical study was performed on coal samples from the East field deposit, Bogovina Basin, Serbia. Fourteen coal samples were collected from different parts of the Main and Upper coal seams from fresh, working faces in the underground subbituminous coal mine. The Lower Miocene (?) coal of the East field is a typical humic coal with huminite, liptinite and inertinite concentrations of up to 81.4 vol.%, 16.1 vol.% and 13.5 vol.%, respectively. Densinite is the most abundant maceral with variable amounts of ulminite and gelinite. Sporinite and liptodetrinite are the most common macerals of the liptinite group. Exsudatinite was detected in the lower part of the Lower coal seam. Inertodetrinite is the most abundant maceral of the inertinite group. The mineral matter consists mostly of clay minerals and carbonates. The mean random huminite reflectance (ulminite B) for the Main coal seam is 0.42 +/- 0.04%Rr, and 0.41 +/- 0.04%Rr for the Upper coal seam, which are typical for an immature to early mature stage of the organic matter. The distribution and abundance of n-alkanes and steranes indicates a significant contribution of epicuticular waxes from higher plants. High amount of phyllocladane-type diterpenoids (16 alpha(H)-phyllocladane) suggests that coal forming plants were conifer families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Sciadopityaceae, and Phyllocladaceae, while a higher amount of pimarane and norpimarane suggests Pinaceae. Taxodiaceae, and Cupressaceae. The pristane/phytane (Pr/Ph) ratio implies variable anaerobic to oxic conditions during sedimentation. The distribution of the hopanes detected in the Bogovina East field coal indicates an immature to early mature stage of the organic matter, which is in agreement with huminite reflectance. The high coal sulphur contents from the East field are characteristic for slightly alkaline depositional environments generated by bentonite from the basement of the Main coal seam. The petrological observation and biomarker composition provide evidence for the generation of immature hydrocarbons which, most probably, originated from the resins and waxes of higher plants, mostly gymnosperms. (C) 2009 Elsevier B.V. All rights reserved

Heavy metals in Neogene sedimentary rocks as a potential geogenic hazard for sediment, soil, and surface and groundwater contamination (eastern Posavina and the Lopare Basin, Bosnia and Herzegovina)

The influence of geochemical processes (weathering, erosion and dilution) of the Internal Dinarides to the Posavina Neogene Basin and their implication to the pollution of the Sava River sediments at four sampling sites in the Eastern Posavina (Zupanja, Brcko, Bosanska Raca and Sremska Mitrovica) was studied.(similar to)For this purpose, comparison of contents of heavy metals (Pb, Zn, Cu, Ni, Cr, Cd, As and Hg) of the Eastern Posavina sediments with local background values was performed. Sediments from two boreholes of the Lopare Basin considered as non-polluted and representative for specific geologic and hydrogeologic system were used for the calculation of local background values. The aim was to assess whether the observed heavy metals concentrations at four sampling sites along the Sava River represent background/natural or anthropogenic contamination. This task was performed using the geo-accumulation index and total enrichment factor. According to values of the total enrichment factor (0.25-0.71), the anthropogenic impact on the investigated area was quite low. The heavy metals contents in river sediments, soil and groundwater were mainly controlled by geochemical processes, particularly weathering (chemical proxy of alteration value approximate to 60). The results also offer novel insights into the elevated geogenic levels of Cr and Ni in the Eastern Posavina region