Enesehinnangu ja meisterlikkuse eesmärkide roll noorsportlaste spordist väljalangemisel Longituuduuring

http://tartu.ester.ee/record=b2610024~S1*es

Chronology of Late Saalian and Middle Weichselian episodes of ice-free lacustrine sedimentation recorded in the Arumetsa section, southwestern Estonia

The information obtained from a 21 m thick open-pit section of silty-clayey sediments in the Arumetsa bedrock valley, southwestern Estonia, revealed that lacustrine to glaciolacustrine sedimentation at the site started prior to 151 ka ago and lasted to about the end of marine isotope stage 6 (MIS6) at 130 ka. Further down from the 151 ka age-level to the bottom of the buried valley there are ca 60 m of lacustrine fine-grained sediments, the age of which remains still unclear. The Late Saalian sediments at Arumetsa are discordantly overlain by Middle Weichselian clay, silt and sand, deposited between ca 44 and 37 ka ago. As testified by optically stimulated luminescence (OSL) ages, and pollen and diatom record, the Middle Weichselian fine-grained sediments contain redeposited Holsteinian but no Eemian pollen, and have not been fully bleached during deposition. Chronological, microfossil and sedimentological data show two hiatuses in the Arumetsa section. The first hiatus has left no sedimentary evidence for the period between ca 130 ka and 44 ka ago (MIS5 to older half of MIS3). The younger hiatus from ca 37 to 22 ka occurs between the Middle Weichselian lacustrine silt and the Late Weichselian till layer on top of the section

Glaciotectonic deformation patterns in Estonia

Field and archival data have been used in compiling the Glaciotectonic Map of Estonia. Two principal types of glaciotectonic deformations shown on this are discussed here: dislocations of rigid bedrock, and soft bed deformations associated with unconsolidated drift masses. Most bedrock disturbances occur in the narrow zone south of the Baltic Klint and in the tectonically crushed zone where the fractured bedrock was easy to break, displace and deform by the moving glacier. Some of the bedrock dislocations are related to ice-marginal deposits of the Late Weichselian Glaciation (Palivere and Pandivere Phases). Most subglacial deformations of soft sediments are simple in style, namely: shear and ductile deformations within a thin layer. The spatial organisation and efficiency of drainage beneath the local ice streams determined the deformational behaviour of sediments at the ice/bed interface. Ice-marginal deposits of the Late Weichselian deglaciation have not been subjected to large-scale compressive deformation. This suggests that most marginal deposits were formed as the result of brief standstills of the ice margin which caused sediment deformation either at the ice margin or beneath the ice sole

Carbonate cementation in the late glacial outwash and beach deposits in northern Estonia

The sedimentary environments, morphology and formation of carbonate cement in the late glacial glaciofluvial outwash and beach deposits in northern Estonia are discussed. Cementation is observed in well-drained, highly porous carbonaceous debris-rich gravel and sand-forming, resistant ledges in otherwise unconsolidated sediments. The cemented units occur as laterally continuous layers or as isolated lenticular patches with thicknesses from a few centimetres to 3 m. The cement is found in two main morphologies: (1) cement crusts or coatings around detrital grains and (2) massive cement almost entirely filling interparticle pores and intraparticle voids. It is exclusively composed of low-Mg calcite with angular equant to slightly elongated rhombohedral and scalenohedral or prismatic crystals, which indicate precipitation from meteoric or connate fresh surface (glacial lake) water and/or near-surface groundwater under low to moderate supersaturation and flow conditions. The absence of organic structures within the cement suggests that cementation is essentially inorganic. The cement exhibits both meteoric vadose and phreatic features and most probably occurred close to the vadose–phreatic interface, where the conditions were transitional and/or fluctuating. Cementation has mainly taken place by CO2-degassing in response to fluctuations in groundwater level and flow conditions, controlled by the Baltic Ice Lake water level, and seasonal cold and/or dry climate conditions

Fiber Optic Sensor for Real-time Monitoring of Freezing–Thawing Cycle in Cryosurgery

Cryosurgery/cryotherapy is a widely used, freezing–thawing technique for the renewal or destruction of pathological tissues by applying localized rapid cooling; however, it still relies on the subjective “expert knowledge” of the physicians without, up to now, real-time monitoring of the treatment. This work focused on assessing the depth of freezing using optical transmission and backscattering measurements from frozen/unfrozen porcine ex-vivo skin samples. An optical fiber-array sensor was subsequently developed to determine the depth of freezing and the associated kill zone during freeze–thawing cycles with sub-millimeter accuracy within the skin tissue