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Number of results: 16
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Abstract

The article focuses on multicomponent system separation with the use of an innovative membrane-based technique i.e. pervaporation. Pervaporation is a membrane technique for separation of liquid mixtures on solid nonporous membranes. Pervaporation is used in this study to separate a quaternary system acetone-butanol-ethanol-water. Such a system may be derived from ABE fermentation process, and the resulting product, biobutanol, is a potential biofuel and may be used in internal combustion engines. Experiments in the study involving concentration of butanol by pervaporation were performed using PERVAP 4060 flat-sheet commercial membrane. To describe the PV process a semi-empirical approach was used. As a result of experiments and calculations permeance coefficients were obtained. Separation and permeance factors were calculated to assess the efficiency of the system separation. Beforehand, activity coefficients were determined for all the components of the mixture with the NRTL equation. Separation coefficients for all the components differed depending on process parameters: concentration, feed flow rate and process temperature. The study confirmed the separation effect of the quaternary system. The most interesting results were obtained for the concentration of butanol. Pervaporation allows to concentrate butanol over 10 times. The permeance coefficient reached for butanol an average value of 7.06·10-3 in comparison with the results for ethanol 3.24·10-2 and acetone 1.83·10-2 [kmol(m2h)-1]. The temperature change from 50 to 70°C led to an increased permeance factor and there was no apparent effect on it in the feed flow rate. Due to the hydrophobicity of the membrane water fluxes in the quaternary system were negative.
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Abstract

Quaternary sediments in the southwestern Nordenskiöld Land are described with particular emphasis put on distribution of erratics against their basset matrices. Results confirm previous suppositions on directions of past glacial advances from east westwards. The latter separated by sea submergences, caused translocations of the rock material. This process was most intensive in upstreams of large mountain valleys.
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Abstract

Studies of Quaternary sediments of South Spitsbergen (Hornsund, Bellsund and northern Billefjorden regions) focus on their occurrence, origin and chronostratigraphy. Methods and results of geological mapping are described. Glacial, glaciofluvial, glaciolacustrine and aeolian sedimentary environments, rock glaciers, taluses and raised marine beaches are presented. Mutual relations of these sediments as well as their radiocarbon and thermoluminescence datings made chronostratigraphy of Late Quaternary glacial episodes possible. Results of preliminary neotectonic studies are also presented, the same as works on periglacial phenomena, chemical weathering and tundra vegetation. Key significance of the studies for the Quaternary evolution of the Arctic and for better recognition of geodynamic phenomena of Pleistocene glaciations in Poland (Tatra and Sudeten Mts included) is underlined.
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Abstract

Thermoluminescence datings of glacial and marine sediments from Sörkapp Land, southern Spitsbergen enabled to limit the Late and Middle Pleistocene glacial events in this area. Sediments of raised beaches at 15—18, 30—38 and 42—56 m a.s.l. in Breinesflya were TL dated for 63, 68 and 87 ka respectively. Four other dates from Lisbetdalen, Slaklidalen and Sergeijevskardet proved two glacial advances during the Sörkapp Land ( = Wiirm) Glaciation. named the Lisbetdalen Stage (47 and 41 ka) and the Slaklidalen Stage (28 and 22 ka). Glacial sediments on slopes of Gavrilovfjellet and Strupryggen were dated for 141 and 217 ka respectively. These dates prove the glaciers of the Wedel Jarlsberg Land (= Riss) Glaciation occupied a considerably larger area in southern Spitsbergen than the glaciers of the following Sorkapp Land Glaciation.
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Abstract

Preliminary results of field investigations and analysis of air photos of the Tjörn Valley region (Wedel Jarlsberg Land, Spitsbergen) are presented. The youngest, Quaternary deposits and landforms were mapped. Reconstruction of the last advance and retreat of the Tjörndals Glacier is also described.
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Abstract

Relief of Svalbard is an effect of varied morphogenetic, exogenic and endogenic processes. Tectonic and glacioisostatic movements of the Earth crust have occurred many a time in this region. Glacial, marine and periglacial features are particularly common. During the Late Quaternary the western Nordenskiöld Land underwent several sea transgressions, followed by glacier advances. Basing on erratics of crystalline rocks transported by sea ice, past sea levels have been established up to 250 m a.s.l. Marine terraces above 60 m a.s.l. date back to the Late Pleistocene, the lower ones are of the Holocene age.
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Abstract

A method of parameters fitting to the experimental vapour - liquid - liquid equilibrium (VLLE) data is presented for the NRTL and the Uniquac equations for six quaternary mixtures. The same equations but with coefficients taken from the simulator Chemcad database were also used for calculation of the VLLE for the same mixtures. The calculated equilibrium temperatures and compositions for all the three phases were compared with the experimental data for these four cases. The investigated models were also applied for calculation of the compositions and temperatures of ternary azeotropes occurring in the considered quaternary mixtures. The computed values were compared with the experimental ones to appreciate the model's accuracy and to confirm whether the model correctly predicts the presence of homo- or heteroazeotrope. The NRTL equation with coefficients fitted to the VLLE data proved to be the most accurate model. For the mixtures containing water, ethanol and two different hydrocarbons this model shows particularly high accuracy. In three cases the mean deviations between the calculated and measured temperatures do not exceed 0.25 K, and for the fourth mixture the difference equals 0.33. Besides, the mean deviations between the calculated and the measured concentrations in the gas and liquid phases, with one exception do not exceed 1 mole %.
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Abstract

Field mapping and analysis of air photos enabled to prepare a photogeological map of Treskelen-Hyrnefjellet-Kruseryggen area in scale of 1:10,000. Slope, glacial and nival landforms and sediments, and ten raised marine beaches were distinguished. Morphogenetic evolution of the area is also presented, with discussion of probable glacier advances and land uplift during the Late Pleistocene and the Holocene.
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Abstract

Results of geological interpretation of air photos from selected parts of southern Spitsbergen are presented. Quaternary and some older landforms and deposits distinguished during the photointerpretation are described on the basis of their discrimination features, as well as origin and spatial realtions. On this ground a code for interpretation of relief elements in polar areas was prepared. A geological interpretation of air photos completed by absolute datings of different deposits enabled to connect studied landforms with the Late Quaternary main glacial episodes. Sea and glacier extents in the northwestern Sörkapp Land, from the Wedel Jarlsberg Land Glaciation (Saale) to the Little Ice Age (Holocene) are presented.
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Abstract

This article presents characteristics of the Quaternary deposits and landforms of Ebbadalen, the Nordenskióldbreen foreląnd and the Wordiekammen massif on the basis of geomorphological mapping of this area and a number of geologic profiles A—L studied in detail. Glaciers were much more expanded during the Pleistocene than they are nowadays. Over a period referred to by the present authors as the Petuniabukta-Adolfbukta Stage they occupied the whole Ebbadalen area and the eastern part of Adolfbukta. Marine terraces of 70- 80, 60—65 and 50—55 m a.s.l. were formed earlier. At the turn of the Pleistocene three marine terraces were produced at 40—45, 30—35 and 20—25 m a.s.l. Throughout the Early Holocene transgression (the Ebbadalen Stage = the Thomsondalen Stage) glaciers occurred in nearly the entire Ebbadalen area and occupied a larger part of Adolfbukta than nowadays. During the Middle and Late Holocene marine terraces of 12—15, 5—8, 3—4 and 1—2 m a.s.l. were initiated. Two more glacier advances, the later relating to the Little Ice Age, took place during the Late Holocene
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Abstract

Attempt of correlation of raised marine beaches and glacial episodes in West Spitsbergen is presented for the Middle and the Late Quaternary. A model of predominating Barents Sea shelf ice sheet during the Saalian and of co-existing distinct local ice domes during the Vistulian is postulated on the basis of varying land uplift. Glacial episodes in Spitsbergen are referred to the ones in continental Europe and North America. Rough prognosis of climatic trends is introduced.
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Abstract

Geological and geomorphological studies in Kaffiöyra and Hermansenöya (Oscar II Land, northwestern Spitsbergen), completed with radiocarbon datings, indicated that the Early Vistulian (Weichselian) Glaciation of presumable regional significance, occupied the whole area. Marine transgression during and after deglaciation reached at least to 65 m a.s.l. Glacioisostatic uplift and marine regression in Kaffiöyra resulted in development of older raised beaches at 52-65 m a.s.l. During the Late Vistulian, Kaffiöyra was occupied partly by outlet glaciers (Aavatsmark, Elise and Andreas), while the Dahl Glacier covered Hermansenöya. Extents of these glaciers were much greater than during the Little Ice Age. Marine transgression during deglaciation reached to 46-48 m a.s.l. at about 12-11.5 ka B.P. During glacioisostatic emergence at 11.5-9 ka B.P., ten younger raised marine beaches were formed in Kaffiöyra. Traces of a probable glacial episode at 3-2.5 ka B.P. were noted in forefields of the Aavatsmark and the Elise glaciers only. In forefields of all glaciers in Kaffiöyra there are deposits and landforms formed during glacial advances of the Little Ice Age and the following continuous retreat. The Aavatsmark Glacier was the only one to indicate surge type readvances at that time.
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Abstract

Studies of the Quaternary evolution of the Hornsund Region in Spitsbergen focused in nine key areas, in which detailed fieldworks with mapping and sampling to radiocarbon and thermoluminescence analyses have been done. Glacial history of the Hornsund Region is known from the Torellkjegla (Holsteinian) Interglacial up to the recent times. The Wedel Jarlsberg Land (Saalian) Glaciation was the most widespread in this part of Spitsbergen and consisted of two stades(?). It was followed by considerable glacier retreat during the Bogstranda (Eemian) Interglacial, the latter being represented by development of soils. Four glacier advances (the two younger ones are the Lisbetdalen and the Slaklidalen stages) occurred during the Sörkapp Land (Vistulian) Glaciation. Three glacier advances (Gronfjorden and Revdalen stages, followed by the Little Ice Age) were recognized for the Holocene. The oldest and highest (although somewhat questionable) raised marine beaches come presumably from the Wedel Jarlsberg Land Glaciation. The beaches 80-100 m a.s.l. were formed during the Bogstranda (Eemian) Interglacial. The beaches 20-60 m a.s.l. are correlated with the Sórkapp Land Glaciation. All the lower marine beaches were formed during the Holocene.
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Abstract

Marine rock-accumulative terraces at 2-230 m a.s.l. in the southern Sörkapp Land are typical for glacioisostaticly uplifted areas. The Holocene terraces reach up to 19 m a.s.l. An outstanding coastal ridge at 9-10 m a.s.l. was radiocarbon-dated at 6580±160 years B.P. No marine transgression during the Holocene on higher and older terraces was noted, what is also confirmed by well preserved raised storm ridges. Any of glacial advances during the Holocene were more extensive than the one of the Little Ice Age. However the Pleistocene glaciations were more extensive. Among glacial landforms in the area there are: ice-cored frontal and lateral moraines up to 70 m high, plains of ground, ablation and fluted moraines, complexes of glaciofluvial fans. The glaciers retreated 0.3-2 km since 1936 i.e. ca 10 m a year on the average. There are large consequent structural landslides on eastern slopes of Keilhaufjellet.
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Abstract

Basing of fieldworks geomorphologic and geologic setting of 14 raised marine beaches in northern Hornsund Region was presented. Their age is approximated by radiocarbon and thermoluminescence datings of sediments. The latter indicated that the four highest but mostly questionable marine beaches (220—230,200—205,180—190 and 100—120 m a.s.l.) should be referred to the Wedel Jarlsberg Land (Saalian) Glaciation. The four lower beaches (80—95, 70—75, 50—60 and 40—46 m a.s.1.) are connected with the Bogstranda (Eemian) Interglacial and the pre-maximum part of the Sorkapp Land (Vistulian) Glaciation. The post-maximum part of this glaciation, including Lisbetdalen Stage (50—40 ka) and Slaklidalen Stage (30—20 ka), was the time when the three still lower marine beaches (32—35, 22—25,16—18 m a.s.l.) were formed. Three lowermost marine beaches (8—12,4.5—6,2 m a.s.l.) are of the Holocene age.
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Abstract

The main relief features of glacier marginal zones in the region between the Billefjorden and Austfjorden comprise ice-cored moraines, outwash plains and glacial lakes. Characteristics of various types of ice-morainic ridges are given. This article presents examples of outwash fan relief. The results of palaeogeographical analysis serve as the basis for distinguishing between three principal stages of development of glacier morphology and meltwater outflow in the region between the Billefjorden and Austfjorden.
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