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EN
Thermo-optic properties enhancement of the bi-stable temperature threshold sensors based on a partially filled photonic crystal fiber was reported. Previously tested transducers filled with a selected group of pure n-alkanes had in most cases differences between switching ON and OFF states. Therefore, the modification of filling material by using additional crystallization centers in the form of gold nanoparticles was applied to minimize this undesirable effect. The evaluation of the thermodynamic properties of pentadecane and its mixtures with 14 nm spherical Au nanoparticles based on the differential scanning calorimetry measurements was presented. Optical properties analysis of sensors prepared with these mixtures has shown that they are bounded with refractive index changes of the filling material. Particular sensor switches ON before melting process begins and switches OFF before crystallization starts. Admixing next group of n-alkanes with these nanoparticles allows to design six sensors transducers which change ON and OFF states at the same temperature. Thus, the transducers with a wider temperature range for fiber-optic multi-threshold temperature sensor tests will be used.
EN
In this short communication, we revise a correlation for the saturated liquid isothermal compressibility based on the data available in DIPPR (Postnikov, 2016) which considers the molecular non-sphericity and addresses a problem of predicting speeds of sound in saturated long-chained alkanes. In addition, we correct a misprint appeared in the cited work and provide programming code used for the realisation of the proposed calculations.
3
Content available remote Oznaczanie jakościowe i ilościowe (GC-FID) wybranych składników ropy naftowej
PL
Zmodyfikowano metodę GC-FID oznaczania ilościowego składników ropy naftowej. Dotychczasowa metodyka wymagała modyfikacji, w tym przede wszystkim dobrania innego rozpuszczalnika do próbek ropy naftowej. Do tej pory wykorzystywano disiarczek węgla (CS2), który jest związkiem silnie kancerogennym, a więc jednym z powodów zmiany rozpuszczalnika były aspekty zdrowotne. Rozszerzono stosowaną metodę o analizę ilościową wybranych komponentów występujących w ropie naftowej. Opracowano analizę ilościową wybranych n-alkanów i izoalkanów oraz niskowrzących związków aromatycznych (BTX). Dobrano program temperaturowy w celu analizy standardów, które posłużyły do utworzenia krzywych kalibracyjnych. Na podstawie tychże krzywych oznaczono wybrane związki chemiczne w sposób ilościowy w około 10 ropach naftowych.
EN
GC-FID method for the quantification of crude oil components was modified. Previous methodology required modification and a new solvent selection for oil samples. Carbon disulfide (CS2) had been used so far and because of it’s highly carcinogenic properties, the author proposed solvent replacement. The method was extended to be used for the quantitative analysis of selected components present in crude oil. Quantitative analysis of the selected n-alkane, iso-alkanes and low-boiling aromatics (BTX) was developed. A temperature program was adjusted for the analysis of standards which were used for the creation of calibration curves. Quantitative analysis of selected compounds was determined based on the curves in about 10 crude oil samples.
EN
The last study on n-alkanes in surface sediments of Taihu Lake was in 2000, only 13 surface sediment samples were analysed, in order to have a comprehensive and up-to-date understanding of n-alkanes in the surface sediments of Taihu Lake, 41 surface sediment samples were analyzed by GC-MS. C10 to C37 were detected, the total concentrations of n-alkanes ranged from 2109 ng g−1 to 9096 ng gg−1 (dry weight). There was strong odd carbon predominance in long chain n-alkanes and even carbon predominance in short chain n-alkanes. When this finding was combined with the analysis results of wax n-alkanes (WaxCn), carbon preference index (CPI), unresolved complex mixture (UCM), hopanes and steranes, it was considered that the long chain n-alkanes were mainly from terrigenous higher plants, and that the short chain n-alkanes mainly originated from bacteria and algae in the lake, compared with previous studies, there were no obvious anthropogenic petrogenic inputs. Terrestrial and aquatic hydrocarbons ratio (TAR) and C21−/C25+ indicated that terrigenous input was higher than aquatic sources and the nearshore n-alkanes were mainly from land-derived sources. Moreover, the distribution of short chain n-alkanes presented a relatively uniform pattern, while the long chain n-alkanes presented a trend that concentrations dropped from nearshore places to the middle of lake.
EN
The o-Ps mean lifetime value in liquids decreases in the presence of the paramagnetic oxygen molecules via the ortho-para conversion process. This effect was observed for several organic samples composed of carbon and hydrogen atoms differing in the arrangement of atoms forming the molecule, e.g. n-alkanes, alcohols, branched isomer of alkane, cycloalkane. The usually observed tendency of the o-Ps lifetime value to be an increasing function of temperature (in the case of measurements performed in vacuum) changes to a decreasing one in the presence of O2 dissolved in the sample. The difference between the o-Ps lifetimes measured in samples in vacuum and in the presence of O2 increases with the distance from the melting point. The ortho-para constant rate λconv was estimated to be ~130 μs–1 at 300 K for three compounds investigated.
EN
Bisnik Cave is an important site of Middle Palaeolithic, with the longest sequence of Neanderthal settlement phases in Central Europe. In the previous studies of the Bisnik sediments, different elements of palaeoenvironment in the periods of Neanderthal occupation have been recognised, except of palaeovegetation, which could not be derived because of lack of preserved plant micro- or macrofossils. The current work is an attempt to reconstruct palaeovegetation in vicinity of the Bisnik Cave, using analysis of composition of plant-derived n-alkanes, preserved in sediments. In our study, we analyzed one sample from each of the sediment's layers 11 - 19c (early Late Pleistocene and late Middle Pleistocene). Abundant n-alkanes (mostly n-C27, n-C29 and n-C31) were found in all the sampled layers except for the layers 12, 16 and 19d, showing no alkanes at all. There is clear diversification of n-alkanes composition and cpr (carbon preference index) values between layers. Analysis of this composition, allows us to claim that the layers 11 and 14 were accumulated when the cave's vicinity was covered by dense coniferous forests, hence upon warm climate. The layers 19, 19a lower, 19b and 19c, presumably originated during cold periods when open woodlands or grasslands dominated. The other analyzed layers could be counected with intermediate vegetation in form of open woodland. However, not all of the achieved results stay in compliance with the actual stratigraphy, established basing on lithological data and palaeoecology offossil fauna, and we hope that explanation of this discrepancy would be possible after more extensive studies of molecular fossils are done.
EN
Positron annihilation lifetime and intensity were measured as a function of temperature for a binary mixture of two normal alkanes. The rotator phase is preceded by the range of about 7 K, in which one observes instability of spectrum parameters. In that range the mixed solid, being initially introduced into rotator phase, transforms to a rigid one in the time scale of several hours.
EN
Kashpir oil shale deposit, located in the Volga region, is left one of two, previously developed, most important (after Baltic kukersites in Leningrad region and Estonia) oil shales resources in Russia. The organic carbon content (Corg) ranges >40%. Besides these oil shales are characterized by increased content of organic sulphur which has a high concentration due to specific sedimentation environment of organic matter (OM) in sediments (Riboulleau et al. 2000). The samples under study were taken from a section near the city of Syzran, in the vicinity of old shale mine 5. In the section of shale rocks the interbedding of oil shales, argillaceous oil shales, kerogen clays and carbonate grey, dark grey and brown clays is observed. All the rocks are saturated by fine-disperse OM of different concentration. Altogether 4 oil shales members are observed with the thickness from 0.08 to 0.3 m. All the rocks are littered by shell detritus. In argillaceous rocks there are many deformed shells and bivalve prints, also ammonites and belemnites are found. In OM-rich rocks macrofauna is found considerably rarer. Among ammonites the representatives of Zaraiskites, Dorsoplanites and numerous bivalves Buchia are determined. The visible thickness of the layer is 2.8 m. Corg content changes from 0.85 to 37.34% in the studied section. According to gas chromatography data the distribution of normal and isoprenoid alkanes changes upward the section. The OM content is sharply dominated by acyclic isoprenoid hydrocarbons. Pristan/phytan ratio <1 in all the samples which testifies to reducing environment predominance during sedimentation both with low and high Corg. Odd carbon number (C15-C19) of n-alkanes is <1 (except sample KS-1/7), and mid-chain (C21-C25) C high (C27-C31) n-alkanes ranges considerably >1, and for medium range CPI in oil shales are the highest (except sample KS-1/7). In OM of clays the hump in the range of high-molecular-weight hydrocarbons, characteristic for steranes, is absent. In the samples KS-1/2, KS-1/4, KS-1/10 normal hydrocarbons C16, C18 dominate, in other fractions the content of these compounds is not so expressed against the background of other n-alkanes. This fact could be connected with the change of redox environment during sedimentation, but Pr/Ph ratio in these samples insignificantly differs from these values of other samples. It can be suggested that isoprenoid components of initial OM were exposed to the least reworking by bacteria during OM formation of the stated above deposits. Practically in all the samples, except KS-1/7 and KS-1/10, low n-alkanes C13-C19 dominate. The increased concentrations of C15-C17 n-alkanes resulted from the participation of phytoplankton in the OM formation of the studied sediments. C27, C29, C31 normal hydrocarbons peaks, which are prevalent in high plant waxes, expressed to a lesser extent relative to the given compounds identified in the OM from oil shales of the Sysola shale-bearing region (Boushnev & Lyurov 2002), which resulted from the low input of terrigenous component to the composition of OM. A certain medium variant of n-alkane distribution presented by higher algae - characteristic C21, C23, C25 homologues predominance is fixed for all the samples. Desulphurization of oil shale bitumen polar fractions, done on Raney nickel, resulted in the equal content of hydrocarbon components in all three studied fractions. In desulphurization products the n-alkanes (C14-C31) are present. The distribution of normal and isoprenoid alkanes is slightly different from the hydrocarbon content of desulphurization products of bitumen polar fractions from the Sysola shale-bearing region which was obtained earlier. If the desulphurization products of Sysola bitumens are dominated by phytane on the background of n- and iso-alkanes, in the desulphurization products of Kashpir bitumens just minor change of isoprenoid/n-alkane ratio at the transition from free to desulphurized fractions is stated. Concerning the Sysola deposits a sharp isoprenoid predominance is observed relating to n-alkanes (3-4 times), basically due to increasing concentration of phytane. Considerable changes are observed in low n-alkanes where in the process of desulphurization even n-alkanes C16 and C18 concentration sharply increases. The content of the given compounds also slightly prevails over odd low structures in the content of free hydrocarbon fraction which testifies to the active contribution of initial biostructures C16, C18 to the content of Kashpir deposit OM. Thus, hydrocarbon content of bitumens of deposits with increased Corg is sharply different from the content of normal and isoprenoid hydrocarbons of organic carbon-poor deposits by great concentrations of isoprenoid hydrocarbons, by isolating two n-alkanes predominance areas, by the increased contribution of low hydrocarbons (C14-C18), supported by the content of desulphurization products of bitumen polar fractions.
PL
W Górnośląskim Zagłębiu Węglowym występują dwa typy genetyczne węgli odzwierciedlające pierwotny materiał roślinny oraz wpływ redukcyjnych lub utleniających warunków środowiska sedymentacji: węgle humusowe i węgle sapropelowe. W celu jakościowo-ilościowej oceny węgli jako skały macierzystej przeprowadzono badania geochemiczne w zakresie analizy elementarnej oraz analizy n-alkanów i izoprenoidów. Do określenia potencjału węglowodorowego skały macierzystej konieczne jest ustalenie składu pierwiastkowego substancji organicznej, pozostającego w ścisłej zależności od jej typu genetycznego. Najczęściej stosowanymi biomarkerami, ze względu na ich powszechne występowanie są n-alkany, a ilościowy stosunek mas cząsteczek nieparzystych do parzystych w łańcuchu molekularnym n-alkanów obrazuje wskaźnik CPI. Stosunek izoprenoidów pristanu do fitanu jest parametrem stosowanym do różnicowania środowisk utleniających i beztlenowych. Parametrem służącym do oceny źródła pochodzenia materii organicznej oraz stopnia jej przeobrażenia jest stosunek izoprenoidów do n-alkanów. W oparciu o uzyskane wskaźniki analityczne dokonano kompleksowej oceny jakości węgli w zakresie ich typu genetycznego, stopnia przeobrażenia termicznego oraz chemizmu środowiska sedymentacji.
EN
As regards origin, two types of coal are found in the Upper Silesian Coal Basin: humic coals and sapropelic coals, which reflects primary plant material and influence of reducing or oxidating conditions in the depositional environment. For the purpose of qualitative and quantitative evaluation of the coals as source rocks, geochemical studies, namely the elemental analysis and n-alkane and isoprenoid analyses were carried out. To determine the hydrocarbon potential of a source rock it is necessary to establish the elemental composition of organic matter, which depends on its genetic type. N-alkanes are the most frequently used biomarkers, considering their common occurrence. The CPI indicator represents the mass ratio of odd to even molecules in the molecular chain of the n-alkanes. The pristine/phytane ratio is a parameter used to differentiate oxidizing environments from oxygen-free environments. The ratio of isoprenoids to n-alkanes is a parameter used for assessment of a source of the organic matter and its transformation degree. On the basis of the obtained analytical indicators, complex evaluation of the coal quality was carried out: their genetic types, thermal transformation degrees and the depositional environment chemistry were determined.
EN
Partition coefficients of benzene, its twelve methylbenzenes and its twelve chlorobenzenes have been estimated on two fused silica capillary columns coated with the stationary phases HP-5 and ZB-WAX at 100-180_C range. These retention data are compared to evaluate the column temperature effect, the dependence of the substituent number and the influence of the stationary phase polarity. The partition coefficient decreases with increasing column temperature in all cases, but, on the contrary, it increases with the number of methyl radicals and chlorine atoms at each stationary phase at each temperature, and it increases for the polar stationary phase. The partition coefficients of the isomers (1,2-), (1,2,3-) and (1,2,3,4-) are larger than those of the other diisomers (1,3-) and (1,4-), triisomers (1,2,4-) and (1,3,5-), and tetraisomers (1,2,3,5-) and (1,2,4,5-). Discussion in terms of physicochemical properties of these isomers is forwarded.
EN
Five lithologically different rock samples from the "Niwka" brickyard exposure, including one coal sample, were geochemically characterized as regards their mineral composition and sedimentary organic matter present in them. Various methods, including: X-ray diffraction, solvent extraction, group separation by preparative thin layer chromatography, infra-red spectroscopy for assessment of the content of different functional groups in total rock extracts and their separated polar compound fractions, and capillary gas chromatography for analysis of aliphatic hydrocarbon fractions. It was found that the "Niwka" brickyard rocks are rich in organic material present as the plant detritus (cane-break) or as compounds adsorbed on clay and carbonaceous minerals. Yields of bitumen extraction, group composition of extracts and content of various functional groups assessed by infra-red spectra seem to be related to mineral composition of the host rocks and type of kerogen present. Higher contents of clay minerals, especially chlorite, enriches both extracts and their polar compound fractions in aliphatic structures while the organic matter of both sandstones analysed contains more condensed aromatic structures and functional oxygen groups. Generally the organic matter of the host rocks was deposited in an oxic environment and belongs to type III kerogen with a dominant terrestrial biogenic source or to type II kerogen of bacterial/terrestrial origin of primary biogenic matter. Its thermal maturity stage can be estimated as end-diagenetic or early catagenetic. The highest maturity is shown by the organic matter in the basal sandstone (the S2 sandstone) and probably is caused by imput of older migrating bitumen. Biodegradation of organic matter seems to be influenced by the mineral composition of the host rock, with a high content of clay minerals giving protection.
EN
The solid-liquid equilibrium (SLE), of 11 binary mixtures of n-alkanes (octadecane, nonadecane, eicosane, heneicosane, docosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane) in ethyl tert-butyl ether, (ethyl 1,1-dimethylethyl ether, ETBE) have been determined from 275 K to the melting temperature of n-alkane. Results of solubility are compared with values calculated by Wilson, NRTL and UNIQUAC equations utilizing parameters from SLE. The existence of solid-solid first order phase transition in hydrocarbons has been considered in the solubility calculations. The best correlation of the solubility data has been obtained by the NRTL equation, where the average root-mean-square deviation of the solubility temperaures is 0.84 K.
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