44 research outputs found

    SUBFOSILNÍ POLYGENETICKÁ PSEUDOČERNOZEM V NAVÁTÝCH PÍSCÍCH PŘI SOUTOKU DYJE S MORAVOU („BARVÍNKŮV HRÚD“), JIŽNÍ MORAVA

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    In the SE surroundings of the Great Moravian site Břeclav-Pohansko the occurrences of aeolian sands in the valleys of the Morava and Dyje Rivers are characteristic. The sands forming dune clusters typically overlie the gravels and sands of the Pleniglacial valley terrace and are dated to Late Glacial, most probably to Younger Dryas. On the dunes the Mesolithic to Slavonic settlements were identified. Complex development of the sanddunes is demonstrated by a subfossil soil (polygenetic pseudochernozem) which evidences the existence of hiatuses in aeolian deposition. Youngest Holocene sediments in the area are overbank silts and loams deposited on the flood plain during high water stands

    NIVNÍ ULOŽENINY DYJE U MICMANIC

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    80 cm thick subfossil soil developed within about 5 m thick overbank sediments of the Dyje River near Micmanice village. During the subsequent phase was a polygenetic pseudochernozem originated (depth 2,30 - 3,10 m, 2950 ± 140 years BP, Gd-30053)

    SPODNOPLEISTOCENNÍ TERASY DYJE VÝCHODNĚ OD PAVLOVSKÝCH VRCHŮ

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    Several relics of a 4045 m terrace are preserved in the area east of the Pavlovské vrchy Hills. They evidence the course of the Dyje River since Lower Pleistocene till present days. The terrace gravels on the right bank of the valley are overlain by loess and slope sediment sequences whereas on the left bank the overburned is represented by patches of aeolian sand

    GEOLOGICKÉ POMĚRY KVARTÉRNÍCH SEDIMENTŮ V OBLASTI BZENEC – PŘÍVOZ

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    Nature sight “Osypané břehy” is situated on the right bank of Morava river near Strážnice. Air-borne sands and fluvial sediments were studied by Petrová – Novák (1998). Fluvioaeolian, air-borne and fluvial sediments were examined in two new boreholes Hodonín-30 and Hodonín-34. Garnet predominates over amphibole and staurolite in air-borne sand, amphibole predominates over garnet and zircon in fluvioaeolian and fluvial sediments. Studies of assemblages of heavy minerals and the character of grains and matrix show the local occurrence of fluvioaeolian sediments from the base of aeolian complex

    Pedological and geochemical investigations at the „Red Outcrop“ of Langenlois (Lower Austria)

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    In einem Aufschluss von Löss-Paläoboden-Sequenzen über Rehberger Amphibolit NW von Langenlois wurden sechs Bodenprofile (Lois 1 bis Lois 6) beprobt und pedologisch, mineralogisch und geochemisch analysiert. Am Profil Lois 7 wurden bodenmikromorphologische Untersuchungen durchgeführt. Zwei Bodenprofile (Lois 1 und 2) haben sich über Amphibolit entwickelt, zwei über einer Amphibolit/Marmor-Wechsellagerung (Lois 5 und 6) und drei Bodenprofile sind Sequenzen von polyzyklischen Paläoböden mit fossilen Bodenhorizonten ohne unterlagerndes kristallines Gestein (Lois 3, 4 und 7). In den Profilen Lois 1–4 und Lois 7 konnten intensive Karbonatanreicherungen beobachtet werden. Diese hohen Mengen an Karbonat können nicht Produkt einer rezenten Bodenbildung sein, sondern sprechen für eine Infiltration von ursprünglich das Profil überlagernden kalzitreichen Sedimenten (Löss), die erodiert wurden. Zudem wurde in Profil Lois 2 ein Kalksinter angetroffen. Dieser Kalksinter könnte aus der Verwitterung der im Profil Lois 6 aufgeschlossenen Marmorlagen stammen. Die Kalksinter-Schicht scheint die Stoffflüsse zwischen unterliegendem Gestein und Solum in den Profilen Lois 1 und 2 mehr oder weniger zu unterbinden, was auch durch die Ergebnisse der geochemischen Analytik unterstrichen wird. In den fossilen Horizonten wurden auch ältere Anzeichen von Tonverlagerung in Form von Tonkutanen über den Aggregaten und darüber hinaus leichte Pseudovergleyungserscheinungen angetroffen. Die mächtigen Profile ohne aufgeschlossenes Grundgebirge (Lois 3, 4 und 7) weisen mehrere polyzyklische Sedimentationsphasen und dadurch mehrere Generationen von fossilen Horizonten auf. Aufgrund der bodenmikromorphologischen Analyse können die Böden vom „Roten Aufschluss“ altersmäßig im unteren bis mittleren Pleistozän oder älter angesiedelt werden.researc

    Disgust sensitivity in early pregnancy as a response to high pathogen risk

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    IntroductionConsidered a part of the behavioral immune system (BIS), disgust sensitivity is expected to be adjusting as a response to the actual level of the environmental health risks.MethodsIn this preregistered study, we tested the hypothesis that disgust sensitivity would be higher during the COVID-19 pandemic compared to the pre-pandemic period in pregnant women. In this between-subject study with a longitudinal trend design, we administered the Disgust Scale-Revised to 200 pregnant women before the pandemic and to 350 pregnant women during the pandemic.ResultsWe found a small but significant effect of the pandemic on disgust sensitivity, such that higher disgust sensitivity was found in women pregnant during the pandemic. This effect was stronger in primiparae, however, the interaction between parity and the pandemic period was not significant. Disgust sensitivity decreased with age. No differences in terms of nausea and vomiting were found between the women pregnant before and during the pandemic.DiscussionOur findings indicate that although BIS is presumed to function as a complex mechanism to prevent health-threatening behaviors, its activation in pregnant women during the COVID-19 pandemic is rather weak

    Identification of the phase composition of solid microparticles in the nasal mucosa of patients with chronic hypertrophic rhinitis using Raman microspectroscopy

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    Solid particles, predominantly in micron and submicron sizes, have repeatedly been observed as a threat to a human health unique compared to the other textures of the same materials. In this work, the hypothesis the solid metal-based particles play a role in the pathogenesis of chronic hypertrophic rhinitis was investigated in patients who had not responded positively to medication. In the group of 40 randomly selected patients indicated for surgical mucotomy, the presence of solid micro- and submicron particles present in their nasal mucosa was assessed. For comparison, a set of 13 reference samples from patients without diagnosed chronic hypertrophic rhinitis was evaluated. The analysis was performed using Raman microspectroscopy. The advantage of this method is the direct identification of compounds. The main detected compounds in the mucosa samples of patients with chronic hypertrophic rhinitis were TiO2, carbon-based compounds, CaCO3, Ca(Fe, Mg, Mn)(CO3)2 MgCO3, Fe2O3, BaSO4, FeCO3 and compounds of Al and Si, all of which may pose a health risk to a living organism. In the reference samples, only TiO2 and amorphous carbon were found. In the control group mucosa, a significantly lower presence of most of the assessed compounds was found despite the longer time they had to accumulate them due to their higher mean age. Identification and characterisation of such chemicals compounds in a living organism could contribute to the overall picture of the health of the individual and lead to a better understanding of the possible causes not only in the chronic hypertrophic rhinitis, but also in other mucosal and idiopathic diseases

    Stochastic evaluation of cutting tool load and surface quality during milling of HPL

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    The topic of the article concerns the mechanics of machining plastics and their machined surface. This article deals with measurements and their stochastic (probabilistic) evaluation of the force and moment loading of the machine tools and workpiece. It also deals with the quality of the machined surface in relation to its surface roughness and surface integrity. Measurements were made under different cutting conditions on a CNC milling machine using a newly designed cutter with straight teeth. The statistical evaluation is presented by bounded histograms and basic statistical characteristics that give a realistic idea of the machining process. The practical focus of the experiments is on the milling of HPL (high-pressure plastic-laminate composite material). The listed procedures can also be applied to other materials and machining methods, and can be used for numerical modelling, setting the optimum parameters of machining technology, or for the design of cutting tools. Numerical modelling and other solution options are also mentioned. We have not yet found detailed information in the literature about the milling of HPL material, and our results are therefore new and necessary.Web of Science1224art. no. 1252

    Numerical analysis of the calcaneal nail C-NAIL

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    The presented article investigates the biomechanics of the calcaneal nail C-NAIL (TM) by numerical calculations and, partially, experimentally. This nail is widely used in trauma and orthopaedics. A numerical model of implants directly interacting with the bone tissue model obtained from CT scans was calculated. The material properties of the bone tissue can be described by several models; in this work, a non-homogeneous material model with isotropic elements and prescribed elastic modulus was used to provide a more accurate model of the applied force distribution on the individual parts of the implants. The critical areas of the nail and its fixtures were investigated using finite element strength calculations to verify their strength and reliability, contributing to the safety and faster and easier treatment of patients. These analyses suggest that the strength of the calcaneal nail C-NAIL, as well as the stabilization of bone fragments resulting from its use, are sufficient for clinical practice.Web of Science1210art. no. 526

    Analytical, stochastic and experimental solution of the osteosynthesis of the fifth metatarsal by headless screw

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    This paper evaluates the various approaches to strength and stiffness analysis of fracture osteosynthesis using a headless Herbert screw. The problem has been extensively addressed using several scientific approaches, namely the analytical approach, stochastic approach, experimental approach, and (marginally) using the finite elements method. The problem is illustrated on the use of a prototype headless screw Ti: 4.0/1.4 x 30/7 (manufacturer: Medin, Czech Republic) and the surgical treatment of the fifth metatarsal fracture. Mathematical equations for the analytical calculation of the maximum stresses in the screw were established for tensile/compression loading. This problem is also interesting because of its static indetermination in tension and compression; for this reason, it was necessary to use the deformation condition, i.e., the relationship between screw extension and bone contraction. The stochastic (probabilistic) approach, i.e., application of the Monte Carlo method, takes advantage of the mathematical equations derived during the analytical solution by respecting of the natural variabilities and uncertainties. The analytical and stochastic approaches were validated by measurements on porcine bones and by the finite element method. The data measured experimentally were also processed and used for deriving an equation, appropriately approximating the data. The main part of the measurement was to determine the axial force generated during osteosynthesis with a headless screw. The obtained compressional force was used to determine the maximal stress in the screw and bone. Finally, the methods were compared. In this paper, comprehensive and original approaches based on the authors' experience with multiple methods are presented. Obtained results are necessary for headless screw designers during optimalization of the implants and are also useful for surgeons developing new surgical techniques. This biomechanical problem was solved in cooperation with the engineering industry and physicians to improve the quality of care for patients with trauma in orthopedics and surgery.Web of Science1219art. no. 961
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