19 research outputs found

    Evaluation of possibilities of the plastic stone masonry of carbonate rocks in Slovakia

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    At plastic processing of rocks, the size of mine blocks,is not decisive but aesthetically interesting textural and coloured parts of raw materials. Technologically are compact positions of travertine with a stripe texture, originating from the Hradišťa pod Vrátnom. An attractive raw material for the production of artificial jewelleries are onyx marbles from the Levice surrouting. In Spišské Podhradie honey-yellow stripy aragonite fills travertine rifts, suitable for the production of jewelleries. A small ornamental ware can also be produced from the compact travertine in Vyšné Ružbachy. A contrast textural arain of crinoid limestones from Krivoklát represents a quality raw material for the production of decorative plastics and jewelleries. The locality Prihradzany-Skalka provides guttenstein limestones, appropriate for the production of bigger plastics and utility articles. Aesthetically stand out articles from hallstatt limestones from Silická Brezová. For the figural treatment and the production of utility articles are suitable čorštynske limestones from the depositg Marmont - Stará Ľubovňa. The most widely used decorative stones are marbles from Tuhár. The interesting are pseudobreccias textures of the recrystallize wetterstein limestones from Tisovec. Marbles from Rákoš have variable colours. For the production of plastics are suitable streaked marbles from Lubeník. Positive results from the technological standpoint have locaties of carbonate rocks

    ON EFFICIENCY OF PATH SYSTEMS INDUCED BY ROUTING AND COMMUNICATION SCHEMES

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    Communication problems are studied as simple directed path systems satisfying given communication requests in point-to-point networks. Efficiency measures of these path systems such as congestion, dilation, compactness and buffer-size are analyzed. We focus on some recent algorithmic developments and novel techniques for the design of efficient communication schemes. Related open problems and an overview of several related research directions are also given

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    Metamorphic Conditions of Neotethyan Meliatic Accretionary Wedge Estimated by Thermodynamic Modelling and Geothermobarometry (Inner Western Carpathians)

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    Metamorphic evolution of an accretionary wedge can be constrained by a reconstructed P–T conditions of the oceanic and continental margin fragments. This paper deals with the metamorphic overprinting of the Inner Western Carpathians (IWC) Meliatic Triassic–Jurassic paleotectonic units after the closure of the Neotethyan Meliata Basin. Medium to high-pressure and lower temperature conditions were estimated by Perple_X pseudosection modelling, combined with garnet–phengite, calcite–dolomite and chlorite thermometers and chlorite–phengite and phengite barometers. The Late Jurassic subductional burial to a maximum 50 km depth was estimated from the Bôrka Unit continental margin fragments at 520 °C and 1.55 GPa. This is compatible with the metamorphic peak garnet–glaucophane–phengite assemblage of blueschist facies in metabasites. The Jaklovce Unit oceanic fragments were subducted to maximum 35–40 km at 390–420 °C and 1.1–1.3 GPa. Metabasalts and metadolerites contain winchite, riebeckite, actinolite, chlorite, albite, epidote and phengite. A glaucophane-bearing metabasalt recorded an intra-oceanic subduction in blueschist-facies conditions. Rare amphibolite-facies metabasalts of this unit indicate the base of an inferred oceanic crust sliver obducted onto the continental margin wedge. The Meliata Unit oceanic/continental margin flysch calciclastic and siliciclastic metasediments suggest the burial to approximately 15–20 km at 250–350 °C and 0.4–0.6 GPa. This is indicated by a newly formed albite, K-feldspar, illite–phengite and chlorite associated with quartz and/or calcite and dolomite in these rocks. Magnesio-hastingsite to magnesio-hornblende bearing metagabbro with newly formed metamorphic magnesio-riebeckite and actinolite is an inferred detached Meliatic block tectonically emplaced in a Permian salinar mélange in the Silica Nappe hanging wall. Reconstructed P–T paths indicate variable metamorphic conditions from the medium-pressure to high-pressure subduction of the Bôrka and Jaklovce units to the Meliata Unit shallow burial in an accretionary wedge during Late Jurassic to Early Cretaceous Meliaticum evolution. Mélange blocks of Meliaticum incorporate different juxtaposed Meliatic paleotectonic units exposed in nappe outliers overlying the IWC Gemeric and Veporic superunits

    Efficient deadlock-free multidimensional interval routing in hypercube-like networks

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    We present deadlock-free packet/wormhole routing algorithms ba\-sed on multidimensional interval schemes for certain hypercube related multiprocessor interconnection networks and give their analysis in terms of the compactness (i.e.~the maximum number of intervals per link) and the buffer-size (i.e.~the ma\-xi\-mum number of buffers per node/link). The issue of a simultaneous reduction of the compactness and the buffer-size is fundamental, worth to investigate and of practical importance, since the interval routing and wormhole routing have been industrially realized in INMOS Transputer C104 Router chips. In this paper we give an evidence that for some well-known interconnection networks there are efficient deadlock-free multidimensional interval routing schemes (DFMIRS) despite of a provable non-existence of efficient deterministic shortest path interval routing schemes (IRS). For dd-dimensional hypercubes (tori) we present a dd-dimensional DFMIRS of compactness 11 and size 22 (of compactness 11 and size 44), while for shortest path IRS we can achieve the reduction to 22 (to at most 55) buffers per node with compactness 2d12^{d-1} (with compactness O(nd1)O(n^{d-1})). For dd-dimensional generalized butterflies we give a dd-dimensional DFMIRS with compactness 22 and size 33, while each shortest path IRS is of the compactness at least superpolynomial in dd. For dd-dimensional cube-connected cycles we show a dd-dimensional DFMIRS with compactness and size polynomial in dd, while each shortest path IRS needs compactness at least 2d/22^{d/2}. We also present a nonconstant lower bound (in the form d\sqrt{d}) on the size of deadlock-free packet routing (based on acyclic orientation covering) for a set of monotone routing paths on dd-dimensional hypercubes

    Geochemistry, Lu–Hf garnet ages, and P–T conditions of blueschists from the Meliatic and Fatric nappes, Western Carpathians: Indicators of Neotethyan subduction

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    Basaltic rocks from ophiolitic mélanges provide information on geodynamic setting, origin, and later tectonometamorphic conditions. This paper resolves the P–T conditions and timing of high-pressure metamorphism in an accretionary wedge that formed during the Late Jurassic closure of the Neotethyan Meliata Basin. Blueschist-facies metabasites of the Meliatic Bôrka Nappe and the Albian conglomerate pebbles of the Fatric Klape Nappe contain rare assemblages of garnet in association with glaucophane, phengite, rutile, and epidote (±albite). Here, we compare a Lu–Hf garnet age from the Meliatic Bôrka Nappe in the southern margin of the Inner Western Carpathians (IWC) with a garnet age from inferred Meliatic blueschists of the Klape Nappe overlying the IWC northern margin. The Hačava type locality of the Bôrka Nappe hosts calc-alkaline type metabasite (∼VAB-C; εNd(245) = +0.9) embedded within Middle to Upper Triassic marbles of the Neotethyan Meliata Basin northern continental margin. The investigated Klape Nappe island arc tholeiite (∼VAB-T; εNd(240) = +5.9) blueschist pebble, and associated deepwater metasedimentary rock pebbles were found in a conglomerate layer of unmetamorphosed Albian flysch. The garnet ages of 153.95±0.69 Ma and 152.1±1.5 Ma correspond to closure of the Meliata Basin during southward intraoceanic and continental margin subduction. This was followed by the exhumation of HP blocks in serpentinite mélange and the formation of an accretionary wedge with included anchimetamorphosed Jurassic flysch. The P–T conditions of the blueschists were constrained by Perple_X modelling to be 520°C and 1.55 GPa for the Bôrka Nappe, and 490–510°C and 1.68–1.72 GPa for a pebble from the Klape Nappe conglomerate. The similarity of garnet dates and metamorphic conditions between the two samples suggest that the blueschists formed during the Late Jurassic Meliatic subduction. The north-vergent Meliatic nappes are the inferred source of the Albian flysch conglomerates deposited in the foreland Fatric Basin. This material was subsequently transported by the Fatric Klape Nappe to the IWC orogenic front during the Turonian, following the closure of the Fatric Basin
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