1,429 research outputs found
Phase-field modelling of gravity-capillary waves on a miscible interface
No full textUsing the approach of direct numerical simulations we investigate the gravity-capillary waves induced on a horizontal interface between two slowly miscible liquids. It is assumed that the liquids are just brought into contact, and thus the interface is slowly smeared by the action of interfacial diffusion. It is also assumed that the initial shape of the interface is distorted by harmonic perturbations, which results in development of the gravity-capillary surface waves. The evolution of the binary mixture is modelled on the basis of the phase-field method. Our results show that in the limiting case of negligible diffusion the classical dispersion relations for immiscible interfaces can be reproduced. Although, for the waves with shorter wavelengths such an agreement is more difficult to obtain. The interfacial diffusion brings an additional dissipation to the fluid system, strongly damping the development of the shorter waves. We also show that the mixing (or the transition of a binary system to the state of thermodynamic equilibrium) is intensified by the presence of the surface waves, and this effect is more important when the liquids are slowly miscible, i.e. when the interfacial diffusion is weak
The data for figures in the paper "Phase-field modelling of gravity-capillary waves on a miscible interface"
No full textThe data is for figures in the paper "Phase-field modelling of gravity-capillary waves on a miscible interface" to be published in European Physical Journal E.</span
Pechoracaris Dzik & Ivantsov & Deulin 2004, GEN. NOV.
No full text<p> PECHORACARIS <b>GEN. NOV.</b></p> <p> <i>Type species: A. aculicauda</i> sp. nov.</p> <p> <i>Diagnosis:</i> Hoplostracan with very long spine-like telson without furca, elongated carapace reaching fifth pleomere; pleopods transformed into spines.</p> <p> <i>Etymology:</i> Derived from the Pechora River region, where the fossils were found, and Latin <i>caris</i> (shrimp).</p> <p> <i>Affinities:</i> The most striking aspect of this arthropod is its single caudal spine (Figs 3, 5). In this respect it somewhat resembles the enigmatic ‘trilobitomorph’ <i>Burgessia bella</i> Walcott, 1912 from the famous Middle Cambrian Burgess Shale of British Columbia (Hughes, 1975). Such affinity is unlikely, however, as the new Russian arthropod shows strongly sclerotized mandibles, which indicates its advanced crustacean affinities.</p> <p> Probably the closest relative of <i>Pechoracaris aculicauda</i> is ‘ <i>Elymocaris</i> ’ <i>urvantsevi</i> Dunlop, 2002 from roughly coeval strata of the Severnaya Zemla archipelago. Although the presence of a medial dorsal plate and rostral plate is claimed in the original description (Dunlop, 2002), the evidence for this seems rather weak. ‘ <i>E.</i> ’ <i>urvantsevi</i> shows a similar shape of the carapace to the new archaeostracan, covering all but the last three segments of the abdomen. Its spinose furca is normally developed, but is significantly shorter than the telson spine.</p> <p> Among the archaeostracans, an elongated caudal spine and reduced furca are known in the Early Devonian <i>Heroldina</i> and <i>Aristozoe</i>, and in the Early Carboniferous <i>Sairocaris</i>. The giant <i>Heroldina rhenana</i> (Broili, 1928) from the Hunsrück Slate of Germany, reaching up to 60 cm in length, is different from the Russian crustacean in the presence of a large rostral plate and dorsal hinge of the carapace (Bergström <i>et al</i>., 1989; Bartels <i>et al</i>., 1998). In its strongly elongated last abdominal segment, <i>Heroldina</i> resembles <i>Aristozoe regina</i> Barrande, 1972 from the Konĕprusy Limestone of Bohemia (Chlupac˘, 1963) and <i>A. virga</i> Chlupac ˘, 1970 from the earliest Devonian Lochkov Limestone. Another Bohemian aristozoid, <i>Pygocaris schuberti</i> Perner 1916 from the Lochkov Limestone, had a thin cuticle (Chlupac˘, 1963) but still does not show even a remote similarity to the Russian form. Archaeostracans with somewhat reduced furca, elongated medial spine and possibly lacking separate rostral plate are known from as far back in the geological past as the Middle Ordovician (Hannibal & Feldmann, 1997).</p> <p> The hoplostracan <i>Sairocaris elongata</i> (Peach, 1882), that notably co-occurs with <i>Anthracophausia</i> in the Early Carboniferous Glencartholm Volcanic Beds of Scotland, has a very short carapace, exposing posterior thoracic segments (Schram, 1979). If the Russian form is truly related to <i>Sairocaris</i>, a carapace reduction took place in the evolution of the lineage.</p>Published as part of <i>Dzik, Jerzy, Ivantsov, Andrey Yu. & Deulin, Yuriy V., 2004, Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia, pp. 83-90 in Zoological Journal of the Linnean Society 142 (1)</i> on pages 84-85, DOI: 10.1111/j.1096-3642.2004.00121.x, <a href="http://zenodo.org/record/4687299">http://zenodo.org/record/4687299</a>
Archangeliphausia Dzik & Ivantsov & Deulin 2004, GEN. NOV.
No full textARCHANGELIPHAUSIA GEN. NOV. <p> <i>Type species: A. spinosa</i> sp. nov.</p> <p> <i>Diagnosis:</i> A generalized anthracophausiid with abdominal pleura bearing a single small spine on their ventral margin.</p> <p> <i>Etymology:</i> Derived from the latinized name of Arkhangelsk and <i>phausis</i> (Greek = shine).</p> <p> <i>Affinities:</i> Brooks (1962) indicated a recessed ‘eye socket’ of the proximal segment of peduncle of antennules as the diagnostic character of his Anthracophausiidae. This feature is not represented in the new genus, which is quite generalized in this respect and may have been anatomically close to the Devonian eocaridids, as indicated also by the long abdominal pleura. However, the more general aspects of <i>Anthracophausia</i> listed by Brooks (1962) - weak sclerotization of generally smooth carapace, margins reinforced with an unusually narrow band, a short rostrum, and lateral flattening of the body due to compression - fit well the Russian material.</p> <p> The Carboniferous species of <i>Anthracophausia</i> reveal dramatically different outlines of abdominal pleura from those in the Russian species. In <i>A. strongi</i> Brooks, 1962, from the Late Carboniferous Mazon Creek fauna of Illinois, the pleural lobes of the abdominal tergites are broadly rounded. In <i>A. dunsiana</i> from the Early Carboniferous Glencartholm Volcanic Beds of Scotland they narrow to form a sharp apex (Schram, 1979). In the new species, rounded lobes are armed with short spines, which seems to be enough to substantiate its taxonomic distinction. Another possible difference between the Russian form and the Carboniferous species of <i>Anthracophausia</i> is the increasingly posterior orientation of the abdominal pleural lobes towards the telson (although not easily discernible because of strong flattening of the specimens). In fact, the faint parabolic lines visible on the paratype of <i>A. strongi</i> (Brooks, 1962; pl. 48: 3) may also indicate a similar shape of the posterior pleural lobes in that species. Some gradient in the shape of pleural lobes is also observable in <i>A. dunsiana</i>.</p> <p> All these distinguishing characters are probably primitive (plesiomorphic) and the new genus is probably transitional between the benthic Eocarididae and typical Carboniferous Anthracophausiidae. It may represent the beginning of the lineage of <i>Anthracophausia</i>. Because of the significant time and morphological distance it seems practical, however, to separate them at the generic level.</p> <p> The Anthracophausiidae probably gave rise to the Recent euphausiaceans, closest to the ancestry of Eumalacostraca among the extant orders (Jarman <i>et al.,</i> 2000). The identified distinction of the anthracophausiids in respect to the euphausiaceans is invariably connected with their basal position in the evolutionary tree: the wide telson, lack of hinge-like connection between the first pleotergite and the carapace, and ventrally extended lobes of the carapace.</p> <p>The Late Carboniferous anthracophausiids are considered near-shore marine filter feeders (Schram, 1981). Offshore eumalacostracan communities are inadequately known, with the available evidence restricted to the British late Early Carboniferous, the low diversity community being represented there by schooling species preserved in great numbers of individuals probably as an effect of mass killing (Schram, 1981).</p>Published as part of <i>Dzik, Jerzy, Ivantsov, Andrey Yu. & Deulin, Yuriy V., 2004, Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia, pp. 83-90 in Zoological Journal of the Linnean Society 142 (1)</i> on page 86, DOI: 10.1111/j.1096-3642.2004.00121.x, <a href="http://zenodo.org/record/4687299">http://zenodo.org/record/4687299</a>
Figure 3 in Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia
No full textFigure 3. Archangeliphausia spinosa sp. nov. A, specimen with oblique dorsoventrally compressed carapace and well preserved scaphocerite of 2nd antenna (PIN 4983/2). B, specimens with partially preserved telson and uropods (PIN 4983/ 32a, b). C, specimens with partially preserved telson and uropods (PIN 4983/12a, b). D, posterior part of abdomen with well preserved 6th pleosomite (PIN 4983/4a). E, posterior part of abdomen with well preserved pleura (PIN 4983/39). F, dorsoventrally compressed 6th pleosomite and partial uropods (PIN 4983/36). G, specimen with well preserved spinose pleura (PIN 4983/31).Published as part of Dzik, Jerzy, Ivantsov, Andrey Yu. & Deulin, Yuriy V., 2004, Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia, pp. 83-90 in Zoological Journal of the Linnean Society 142 (1) on page 88, DOI: 10.1111/j.1096-3642.2004.00121.x, http://zenodo.org/record/468729
Figure 2 in Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia
No full textFigure 2. Archangeliphausia spinosa sp. nov. A, holotype (PIN 4983/1a: right) and associated specimen (PIN 4983/1b). B, largest specimen found (PIN 4983/35), with relatively thick cuticle. C, juvenile specimen (PIN 4983/37). E, specimen with dorsoventrally compressed telson and uropods (PIN 4983/28; see also Fig. 4C). D, posterior part of abdomen with well preserved 6th pleosomite and telson (PIN 4983/8).Published as part of Dzik, Jerzy, Ivantsov, Andrey Yu. & Deulin, Yuriy V., 2004, Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia, pp. 83-90 in Zoological Journal of the Linnean Society 142 (1) on page 87, DOI: 10.1111/j.1096-3642.2004.00121.x, http://zenodo.org/record/468729
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Discussion of ‘First finds of problematic Ediacaran fossil <i>Gaojiashania</i> in Siberia and its origin’
No full textY. Cai & H. Hua comment: Zhuravlev, Gámez Vintaned & Ivantsov (2009) reported the problematic Ediacaran fossil Gaojiashania annulucosta in Siberia and they considered that this is the first find of Gaojiashania outside China, since Gaojiashania had previously only been reported from the Gaojiashan Member of the middle Dengying Formation in the Ningqiang area, southern Shaanxi Province, South China. However, we believe that the so-called Siberian Gaojiashania was mis-identified, and what was described as Gaojiashania annulucosta by Zhuravlev, Gámez Vintaned & Ivantsov (2009) is more appropriately ascribed to Shaanxilithes ningqiangensis, another problematic Ediacaran fossil that has also been known from the Gaojiashan Member in Shaanxi Province of South China (Chen, Chen & Lao, 1975; Xing et al. 1984), as well as the stratigraphically equivalent Taozichong Formation in Guizhou Province (Hua, Chen & Zhang, 2004) and the Jiucheng Member (Dengying Formation) in Yunnan Province of South China (Zhu & Zhang, 2005), the Zhoujieshan Formation in Qinghai Province (Shen et al. 2007), and the Zhengmuguan Formation in Ningxia Hui Autonomous Region of North China (Shen et al. 2007).</jats:p
Saltikov-Shedrin's traditions in literary creation of Andrey Platonov
No full textIn this article the author throws light on connections between the creative work of Andrey Platonov and satire of Mikhail Saltikov-Shedrin. Author deduces similarity of the destinies of two Great Russian writers; she notifies likeness of their literary stylistics, unity of their literary characters and vehicles
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