102,998 research outputs found
A nonlinear theory for shells with slowly varying thickness
No full text1 online resource (PDF, 6 pages)Lewicka, Marta; Mora, Maria Giovanna; Pakzad, Mohammad Reza. (2008). A nonlinear theory for shells with slowly varying thickness. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/179960
Baltistena amplicollis Batelka & Rosová & Prokop 2023, comb. nov.
No full text<i>Baltistena amplicollis</i> (Ermisch, 1941) comb. nov. <p>(Figs 2D–G)</p> <p> <i>Mordellistena amplicollis</i> Ermisch, 1941a: 182. Holotype: Baltic amber.</p> <p> <b>Type material examined.</b> HOLOTYPE (SDEI): ‘ MORDELLISTENA [p] / amplicollis [hw] / det. Ermisch 194 [p] i [hw, sic; white label glued on a bigger white label] // TYPE [p; in black frame, red label glued on the bigger white label] // SDEI Müncheberg / SDEI-Amb-000640 [p; yellowish label]’.</p> <p> <b>Comments on identification.</b> As pro- and mesotarsomere IV are distinctly broader and shallowly emarginated, this species cannot be attributed to <i>Mordellistena</i>. To distinguish it from other Eocene Mordellistenini see the Key below. Because of the uncertain generic identity of this species, it is transferred here into <i>Baltistena</i> new collective group.</p>Published as part of <i>Batelka, Jan, Rosová, Kateřina & Prokop, Jakub, 2023, Diversity and morphology of Eocene and Oligocene Mordellidae (Coleoptera), pp. 451-478 in Acta Entomologica Musei Nationalis Pragae 63 (2)</i> on page 458, DOI: 10.37520/aemnp.2023.027, <a href="http://zenodo.org/record/10621277">http://zenodo.org/record/10621277</a>
Rovnostena ponomarenkoi Batelka & Rosová & Prokop 2023, comb. nov.
No full text<i>Rovnostena ponomarenkoi</i> (Odnosum & Perkovsky, 2009) comb. nov. <p> <i>Glipostena ponomarenkoi</i> Odnosum & Perkovsky,2009: 1095. Holotype: ♀, Rovno amber.</p> <p> <b>Comments on identification.</b> According to ERMISCH (1941b), the genus <i>Glipostena</i> belongs to the group of genera that are defined by ‘Der Halsschild weniger breit als lang’ [= the pronotum slightly wider than long], while in <i>G</i>. <i>ponomarenkoi</i> <i>,</i> according to its description, the pronotum is 1.7–1.8× wider than long, that is, much wider than cited by ERMISCH (1941b). In the comparison by ODNOSUM & PERKOVSKY (2009), this species shares with <i>G</i>. <i>sergeli</i> from Baltic amber ‘short lateral ridges taken not more than one third of the hind tibia width and parallel to its apical margin’, which according to the authors ‘sharply differentiate’ <i>G</i>. <i>ponomarenkoi</i> from recent species that have long ridges that reach the middle of the hind tibia and are not parallel with the apical margin (see, e.g., ERMISCH 1941b: fig. 13; ERMISCH 1952: fig. 21; FRANCISCOLO 2000:figs 1, 2). The comb formula for species of <i>Glipostena</i> is usually 4//2/1/1/0 or rarely 3–5//3/1/1/0 (FRANCISCOLO 1999), while in <i>G</i>. <i>ponomarenkoi</i> it is 6//5/4/3/0. The shape of maxillary palpomeres, an important generic character of <i>Glipostena</i>, is not described for this fossil.</p> <p> In summary, <i>G</i>. <i>ponomarenkoi</i> differs from all extant <i>Glipostena</i> in terms of three important generic characters.Therefore, its assignment to this extant genus is not accepted and this species is transferred to <i>Rovnostena</i> new collective group.</p>Published as part of <i>Batelka, Jan, Rosová, Kateřina & Prokop, Jakub, 2023, Diversity and morphology of Eocene and Oligocene Mordellidae (Coleoptera), pp. 451-478 in Acta Entomologica Musei Nationalis Pragae 63 (2)</i> on page 472, DOI: 10.37520/aemnp.2023.027, <a href="http://zenodo.org/record/10621277">http://zenodo.org/record/10621277</a>
The matching property of infinitesimal isometries on elliptic surfaces and elasticity of thin shells
No full textUsing the notion of Gamma-convergence, we discuss the limiting behavior of the three-dimensional nonlinear elastic energy for thin elliptic shells, as their thickness h converges to zero, under the assumption that the elastic energy of deformations scales like h^\beta with 2<\beta<4. We establish that, for the given scaling regime, the limiting theory reduces to linear pure bending. Two major ingredients of the proofs are the density of smooth infinitesimal isometries in the space of W^{2,2} first order
infinitesimal isometries, and a result on matching smooth infinitesimal isometries with exact isometric immersions on smooth elliptic surfaces
Erwartungen der Wirtschaft an die wissenschaftliche Weiterbildung der Hochschulen: Umsetzungsprobleme und Praxiserfahrungen
No full textGraeßner G. Erwartungen der Wirtschaft an die wissenschaftliche Weiterbildung der Hochschulen: Umsetzungsprobleme und Praxiserfahrungen. In: Prokop E, ed. Problemkreis Wissenschaft, Hochschule und wissenschaftliche Weiterbildung. Beiträge / AUE, Hochschule und Weiterbildung ; 30. Vol 30. Bielefeld: AUE e.V., Hochschule und Weiterbildung; 1994: 7-14
Shell theories arising as low energy Gamma-limit of 3d nonlinear elasticity
No full textWe discuss the limiting behavior (using the notion of Gamma-limit) of the 3d nonlinear elasticity for thin shells around an arbitrary smooth 2d surface. In particular, under the assumption that the elastic energy of deformations scales like h^4, h being the thickness of a shell, we derive a limiting theory which is a generalization of the von Kármán theory for plates
Baltistena sergeli Batelka & Rosová & Prokop 2023, comb. nov.
No full text<i>Baltistena sergeli</i> (Ermisch, 1943) comb. nov. <p>(Figs 5F–J)</p> <p> <i>Glipostena sergeli</i> Ermisch, 1943: 65. Holotype: J, Baltic amber.</p> <p> <b>Type material examined.</b> HOLOTYPE: (SDEI):, [two white labels with double black frames glued on left and right side of microscope slide, the other labels glued on top of them] ‘ Glipostena [hw] / Sergeli sp. n. [hw] / det. Ermisch 1942 [p; white label] // Ermisch (Type) [hw; double framed white label on the left side of microscope slide] // TYPE [p; in black frame, red label] // SDEI Müncheberg / SDEI-Amb-000647 [p; yellowish label] / coll. Dr.Sergel / ded. Novemb. 1942 [hw; double framed, white label on the right side of the microscope slide]’.</p> <p> <b>Comments on identification.</b> Terminal palomere of maxillary palpus is malleiform (bean-like in shape), i.e., of type C sensu FRANCISCOLO (1957a), versus equilateral triangular in extant species of <i>Glipostena</i> Ermisch, 1941, i.e., of type B (FRANCISCOLO (1957a). Comb formula 7//5/3/2/0 and length and orientation of all combs are very different from those in extant species: combs of <i>G. sergeli</i> are too short, more transverse and more abundant on metatibia and the first three metatarsomeres (for details see under <i>Rovnostena ponomarenkoi</i> (Odnosum & Perkovsky, 2009)). To distinguish it from other Eocene Mordellistenini see the key below.</p> <p> Because of the uncertain generic identity of this species, it is transferred here into <i>Baltistena</i> new collective group.</p>Published as part of <i>Batelka, Jan, Rosová, Kateřina & Prokop, Jakub, 2023, Diversity and morphology of Eocene and Oligocene Mordellidae (Coleoptera), pp. 451-478 in Acta Entomologica Musei Nationalis Pragae 63 (2)</i> on page 459, DOI: 10.37520/aemnp.2023.027, <a href="http://zenodo.org/record/10621277">http://zenodo.org/record/10621277</a>
Talbragaria australis Sroka & Prokop 2023, sp. nov.
No full text<p>3.2. Talbragaria australis sp. nov.</p> <p>Figs 1, 2</p> <p>Plecoptera sp. in Beattie and Avery (2012: fig. 8D, F)</p> <p>Diagnosis.</p> <p> The new species is distinguishable from all other known fossil Notonemouridae by the combination of the following characters: crossvein mp-cua ca 1.2 × longer than rp-ma; mp-cua crossvein ca 1.6 × longer than the longest crossvein in the area between CuA and CuP (on contrary, mp-cua crossvein more than twice as long as the longest crossvein in the area between CuA and CuP in closely related genus <i>Paranotonemoura</i> Cui and Béthoux, 2018); length of second tarsomere subequal to two thirds of third tarsomere length; female with pronounced corrugated subgenital plate on abdominal sternite VIII and corrugated anal plates on segment IX, narrowed posteriorly.</p> <p>Etymology.</p> <p>The name refers to country where holotype and paratype specimens were found.</p> <p>Type material.</p> <p> <b>Holotype</b>: F.136 856 (part) and F.136 857 (counterpart), female imago. - <b>Paratype</b>: F.137 576 (part) and F.137 577 (counterpart), female imago.</p> <p>Type locality and strata.</p> <p>The Talbragar Fossil Fish Bed site is approximately 25 km northeast of Gulgong in New South Wales, Australia (Beattie and Avery 2012). Stratigraphically the unit is correlated with the Purlawaugh Formation of the Surat Basin and corresponding to the latest Oxfordian-Tithonian, Upper Jurassic.</p> <p>Description.</p> <p> Body length ca 10-12.5 mm. - <b>Head</b>: Prognathous, ca 1.2 × longer than wide (Fig. 2C). Antennae probably nearly completely preserved, visible portions up to 0.7 × body length (Fig. 2A, B). Compound eyes rounded, positioned laterally. Ocelli not visible. Clypeus trapezoidal, approximately twice wider than long (Fig. 2C). Labrum rounded anteriorly. Other mouthparts not recognizable. - <b>Thorax</b>: Prothorax rectangular, ca 1.5 × wider than long, lateral margins rounded (Fig. 2A, B). Meso- and metathorax equal in length, each ca 1.4 × longer than prothorax. Two pairs of fully developed wings. Forewing incomplete, probably slightly longer than body. Forewing venation only partially preserved (Fig. 1A, B, F-H), ScP adhered to RA and again diverges from it more distally, RA simple, crossvein between RA and RP close to the point of connection of ScP with RA. Further two crossveins between RA and PR more basally. RP bifurcated just distally from the crossvein between RA and RP. Two crossveins between RP and M in proximal portion of wing, further oblique slightly sigmoidal crossvein between RP and M more distally, close to RP bifurcation. Hind wings preserved only fragmentary in anterior part, course of discernible veins (C, ScP, RA and RP) identical to forewing (Fig. 1A, B, F-H). Legs slender, length increases from forelegs to hind legs. Femora and tibiae elongated, femora ca 4-6 × longer than wide, tibiae ca 10-14 × longer than wide. Tarsi incomplete, with only second and third tarsomeres preserved; length of second tarsomere subequal to two thirds of third tarsomere length (Fig. 1C). Claws approximately as long as third tarsomere width. - <b>Abdomen</b>: Elongate, narrow, ca 5 × longer than wide. In female, pronounced, well sclerotized and corrugated subgenital plate on sternite VIII (Figs 1D, E, 2D, E). Sternite IX produced posteromedially into narrow corrugated subanal plates. Male genitalia unknown. Cerci short, one-segmented (Fig. 1D, E).</p> <p>Additional Plecoptera specimens.</p> <p> Apart from the holotype and paratype of <i>Talbragaria australis</i> <b>gen. et sp. nov.</b>, two further specimens of Plecoptera from the same locality were identified in the collection of the Australian Museum, Sydney, Australia under accession numbers F.136 851 (part and counterpart, Fig. 2F,G) and F.137 324 (Fig. 2H). Due to their state of preservation and lack of diagnostic characters, it is not possible to attribute them unambiguously to <i>T. australis</i> <b>gen. et sp. nov.</b>, although due to their similarity in size they might be conspecific.</p>Published as part of <i>Sroka, Pavel & Prokop, Jakub, 2023, New fossil stoneflies (Plecoptera: Arctoperlaria) from Australia testify ancient dispersal across Pangea, pp. 881-888 in Arthropod Systematics & amp; Phylogeny 81</i> on page 881, DOI: 10.3897/asp.81.e10983
ARCHITEKTURA OBRONNA. METODOLOGICZNA HIPOTEZA DZIALANIA W TRUDNYCH KWESTIACH OCHRONY ZABYTKOWYCH OBIEKTÒW ( Architettura difensiva. Un’ipotesi metodologica per la gestione della tutela degli edifici monumentali)
No full textL'articola affronta le difficili problematiche riguardanti la tutela dei complessi difensivi, fornisce le proposte metodologiche per la loro valorizzazione e conservazione
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