Three different lithotypes (xylitic, gelified and matrix) of Pliocene lignite from the Velenje Basin, Slovenia, were investigated to establish the variations of biomarker compositions in solvent ...extracts and the stable isotope (carbon and nitrogen) compositions of bulk material. From the biomarker results, the xylitic lithotype almost exclusively originates from gymnosperms (conifers such as Taxodiaceae), as indicated by the very high contents of sesquiterpenoids and diterpenoids but very low abundances of n-alkanes and non-hopanoid triterpenoids. The relative proportion of gymnosperms to angiosperms in the paleomire is reflected by the ratio of diterpenoids to the sum of diterpenoids and non-hopanoid triterpenoids (Di-/(Di-+Tri-terpenoids)), which is close to 1 (av. 0.99) in the xylitic lithotype. The predominance of diterpenoids from conifers in the xylitic lithotype is associated with high C/N ratios and intermediate total sulfur (TS). The very low abundance of hop-17(21)-ene and the absence of further hopanoids in the xylitic lithotype indicate a restricted influence of bacterial degradation under relatively dry conditions in the paleomire. The matrix lithotype also originated preferentially from gymnosperms under dry depositional conditions, as indicated by the high Di-/(Di-+Tri-terpenoids) ratio (0.95), low amounts of hopanoids and low TS content. The gelified lithotype is characterized by a high content of n-alkanes and wide variation of the Di-/(Di-+Tri-terpenoids) ratio (0.13–0.88), indicating a fluctuating contribution of angiosperms to the plant community in the paleomire during formation of this lithotype. In addition, the high abundance of hop-17(21)-ene and TS in the gelified lithotype compared with the other two lithotypes suggests the effect of bacterial activity under relatively wet/humid conditions during formation of the gelified lithotype, which is also supported by the considerable content of mid-chain n-alkanes.
The high correlation between the δ13C and δ15N values (R2 = 0.68) indicates that the stable carbon and nitrogen isotope composition in the Velenje lignites were probably influenced by the same factors (e.g. precursor plants and/or microbial activity). The stable carbon isotopic values (av. −25.44‰) and nitrogen isotopic values (av. 2.15‰) of the xylitic lithotype are higher than those of the gelified lithotype (av. δ13C = −27.48‰, δ15N = 1.37‰) and the matrix lithotype (av. δ13C = −27.09‰, δ15N = 1.10‰). The relatively high correlation between the diterpenoid content and both δ13C and δ15N values suggests that the stable carbon and nitrogen isotopic composition of the three lithotypes might reflect the composition of the original plant material in the paleomire. The dominance of conifers as precursor plants in the xylitic lithotype might be the main reason for the higher δ13C values and probably also the higher δ15N values. The relatively higher δ15N values in the xylitic lithotype than in the other types could be explained by the high amount of decay-resistant xylem and low mineral (e.g. clay) content in the xylitic lithotype. The slightly lower δ13C but higher δ15N values in the gelified lithotype than in the matrix lithotype can be explained by variation of parent plant materials and the influence of bacterial activity.
•Different lithotypes (xylitic, gelified and matrix) of Pliocene lignite from the Velenje Basin, Slovenia, were analyzed for biomarkers and stable isotope (C and N) compositions.•The ratio of diterpenoids/(diterpenoids + triterpenoids) reflects the relative proportions of gymnosperms and angiosperms.•Xylitic and matrix lithotypes originate from gymnosperms, while gelified lithotypes are characterized by a fluctuating contribution of angiosperms.•The highest δ13C and δ15N values were measured in xylitic lithotype samples.•The δ13C and δ15N composition is preferentially influenced by the composition of the precursor plants community.
Pronounced tectonic and paleogeographic changes were detected in the Alpine–Pannonian region during the Miocene at the interface between the Alps, the Dinarides, and the Pannonian Basin. To ...understand the major tectonic, paleogeographic, and paleoclimatic changes during this period, geochemical and mineralogical investigations were carried out on the fine-grained clastic sedimentary rocks in the Tunjice Hills. The paleoweathering indicates a cold and/or arid to a warm and humid period. The paleoclimate and the regional climatic conditions correspond well with the Middle Miocene Climatic Optimum. The mineral composition shows an abundance of quartz and calcite. Quartz is associated with detrital origin from volcanic and metamorphic rocks of the Eastern and Southern Alps and with authigenic processes in sediments. Calcite is related to authigenic origin formed in shallow marine environments and to detrital provenance from the Southern Alps. Not all discriminant functions based on major oxides provided adequate results in determining the tectonic setting. The source rocks were subjected to oceanic island arc and collision. Moreover, sedimentation was influenced by both active and passive margin settings. The former is related to the Alpine collision, which continued from the Cenozoic onward, and the latter is connected to the processes associated with the formation of the Pannonian Basin System, which began in the late Early Miocene.
The purpose of this study was to determine the effectiveness of laser-activated irrigation by photon-induced photoacoustic streaming (PIPS) in the reduction of Enterococcus faecalis in root canal ...disinfection, varying laser energy output, and sodium hypochlorite (NaOCl) concentration. For effective removal of the smear layer, the sequence and resting time of the final irrigation steps were modified compared with the standard PIPS protocol.
Eighty-six extracted single-rooted teeth were mechanically prepared, sterilized, and inoculated with E. faecalis for 4 weeks. Teeth were divided into 9 groups and treated with an Er:YAG laser using a PIPS 600/9 tip at the following parameters: 10 mJ or 20 mJ, 15 Hz, and a 50-microsecond pulse duration at 0.15 W or 0.3 W average power, respectively. Root canals were irrigated with different concentrations of NaOCl (ie, 1%, 3%, and 5% and activated using the adjusted PIPS protocol). The bacterial count was performed immediately after and 48 hours after decontamination and new incubation on an agar plate.
A statistically significant difference in bacterial counts (P < .05) was detected in all groups before and directly after the treatment and in groups treated with 5% NaOCl 48 hours after treatment. Scanning electron microscopic imaging showed an absence of bacteria and biofilm in the scanned areas after treatment with 5% NaOCl.
Laser-activated irrigation using 5% NaOCl and a modified PIPS protocol resulted in effective eradication of the bacterial biofilm and removal of the smear layer.
•The effective reduction of E. in root canal disinfection was performed using a laser.•The adjustment of the final irrigation sequence in the PIPS is proposed.•Treatment safety is increased using lower laser energy without diminished efficacy.•Three percent NaOCl during instrumentation is recommended to avoid the weakening of dentin.
A sustainable solution for the global construction industry can be partial substitution of Ordinary Portland Cement (OPC) by use of supplementary cementitious materials (SCMs) sourced from industrial ...end-of-life (EOL) products that contain calcareous, siliceous and aluminous materials. Candidate EOL materials include fly ash (FA), silica fume (SF), natural pozzolanic materials like sugarcane bagasse ash (SBA), palm oil fuel ash (POFA), rice husk ash (RHA), mine tailings, marble dust, construction and demolition debris (CDD). Studies have revealed these materials to be cementitious and/or pozzolanic in nature. Their use as SCMs would decrease the amount of cement used in the production of concrete, decreasing carbon emissions associated with cement production. In addition to cement substitution, EOL products as SCMs have also served as coarse and also fine aggregates in the production of eco-friendly concretes.
The Miocene deformation history of magmatic and host metamorphic rocks and surrounding sediments was reconstructed by measuring meso- and microscale structures and anisotropy of magnetic ...susceptibility (AMS) data in order to constrain the structural evolution of the Pohorje pluton during the onset of lithospheric extension at the Eastern Alps–Pannonian Basin transition. Principal AMS axes, lineation and foliation are very similar to mesoscopic lineation and foliation data from the main intrusive body and from some dykes. Although contribution from syn-magmatic texture is possible, these structures were formed during the cooling of the pluton and associated subvolcanic dykes just shortly after the 18.64 Ma pluton intrusion. Dykes emplaced during progressively younger episodes reflect decreasing amount of ductile strain, while firstly mesoscopic foliation and lineation, and then the tectonic AMS signal gradually disappears. In the structurally highest N–S trending dacite dykes, the AMS fabric only reflects the magmatic flow. The Miocene sediments underwent the same, NE–SW to E–W extension as the magmatic and host metamorphic rocks as indicated by both AMS and fault-slip data. All these events occurred prior to ~ 15 Ma, i.e., during the main syn-rift extension of the Pannonian Basin and during the fastest exhumation of the Tauern and Rechnitz windows, both demonstrating considerable extension of diverse crustal segments of the Alpine nappe pile. After a counterclockwise rotation around ~ 15 Ma, the maximum stress axis changed to a SE–NW orientation, but it was only registered by brittle faulting. During this time, the overprinting of a syn-rift extensional AMS texture was not possible in the cooled or cemented magmatic, metamorphic and sedimentary rocks.
The main objective of the study was to produce alternative binder materials, obtained with low cost, low energy consumption, and low CO
production, by regenerating end-of-life (EOL) materials from ...mineral deposits, to replace ordinary Portland cement (OPC). The materials analyzed were ash and slag from the Turceni thermal power plant deposit, Romania. These were initially examined for morphology, mineralogical composition, elemental composition, degree of crystallinity, and heating behavior, to determine their ability to be used as a potential source of supplementary cementitious materials (SCM) and to establish the activation and transformation temperature in the SCM. The in-situ pozzolanic behavior of commercial cement, as well as cement mixtures with different percentages of ash addition, were further observed. The mechanical resistance, water absorption, sorptivity capacity, resistance to alkali reactions (ASR), corrosion resistance, and resistance to reaction with sulfates were evaluated in this study using low-vacuum scanning electron microscopy.
Phase relations among the mineral assemblages of UHP kyanite eclogite were investigated in the Pohorje Mountains of the Eastern Alps. Ultrahigh-pressure metamorphism resulted from intracontinental ...subduction during the Cretaceous (ca. 92Ma). Kyanite-bearing eclogites are associated with meta-ultramafic rocks including UHP garnet peridotites and are embedded in metapelitic gneisses and micaschists. The kyanite eclogites contain a peak metamorphic assemblage of garnet, omphacite, kyanite and phengite. Pyrope-rich garnet is unzoned and almost free of inclusions. The non-stoichiometric supersilicic omphacite contains up to 5mol% of Ca-Eskola molecule. Breakdown of omphacite during decompression resulted in exsolution of oriented rods of silica. Phengite contains up to 3.5 Si a.p.f.u. Polycrystalline quartz inclusions in peak-pressure minerals – garnet, omphacite and kyanite – are surrounded by radial fractures diagnostic of the former presence of coesite. Peak-pressure minerals are replaced by symplectites of diopside+plagioclase+amphibole after omphacite, plagioclase+biotite after phengite and sapphirine+corundum+spinel+anorthite after kyanite. Sapphirine has composition close to (Mg, Fe)12.4 Al38.9 Si4.5 O80 in average, which is amongst the most aluminous yet reported. Peak metamorphic conditions were constrained from calculated phase equilibria in the NKCFMASH system with the fixed bulk-rock composition, and conventional geothermobarometry. This approach led to consistent results, the calculated peak P–T conditions of 3.0–3.7GPa and 710–940°C, in the stability field of coesite and the same range as metamorphic conditions recorded by the associated garnet peridotites. This implies that eclogites and their host rocks were subducted to depths of about 100km. The relatively high temperature at peak pressure, compared to UHP rocks of Tertiary age in the Western Alps where mostly oceanic crust was subducted, probably resulted from radiogenic heat production by subducting continental crust, in the intra-continental setting of the Cretaceous subduction zone in the Eastern Alps.
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► Significant enlargement of UHPM terrane in Pohorje, Eastern Alps. ► UHPM (3.5–3.7GPa; 800–940°C) due to Cretaceous intracontinental subduction. ► Contrasting types of subduction and UHPM in the Alps: oceanic vs. continental.
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