87,776 research outputs found
Hydrodynamics and Metzner-Otto correlation in stirred vessels for yield stress fluids
No full textThis paper investigates the hydrodynamics and power consumption in laminar stirred vessel flowusing numerical computation. The Metzner–Otto correlation was established for mixing in power-law fluids. This paper focuses on its application to yield stress fluids. Distributions of shear rates and their link to power consumption for helical and anchor agitators are discussed. Insight is sought from the analytical formula for Taylor–Couette flows. Laws are established for Bingham, Herschel-Bulkley and Casson fluids and reveal similar results. Fully or partially sheared flow situations with plug regions are considered. Depending on the fluid model, the concept is valid or constitutes a satisfactory approximation for fully sheared flows. When the flow is partially sheared, the expression depends on the Bingham number and the concept must be adapted. The results of the numerical simulations are interpreted in the light of this analysis and results from the literature
Joachim K. Metzner, Man and Environment in Eastern Timor
No full textThomaz Luis Filipe F. R. Joachim K. Metzner, Man and Environment in Eastern Timor. In: Archipel, volume 21, 1981. pp. 204-208
Corythalia drepanopsis Bayer & Höfer & Metzner 2020, sp. nov.
No full text<i>Corythalia drepanopsis</i> sp. nov. <p>Figs 1B, 13 A–C, 61F, 71G–I, 75J–L</p> <p>urn:lsid:zoobank.org:act: 5A72BC0A-03CA-45B8-9280-259E5281325A</p> <p> <b>Type material.</b> Holotype: ♀, BRAZIL: Acre: Rio Branco, Reserva Humaitá, 9°45’00”S, 67°40’12”W, about 160 m a.s.l., secondary forest, H. Höfer, H. Metzner, A.D. Brescovit & A.B. Bonaldo leg. 10–13 Apr. 1996, interim deposition SMNK-ARA 02860, final deposition IBSP 209866. Paratypes: 2 ♀ with the same data as for holotype: ♀ with sample number F-2 (leg IV, left missing, SMNK-ARA 02860); ♀ with sample no. F-3 (leg II, right missing, IBSP 209867).</p> <p> <b>Etymology.</b> The specific name refers to the similarity of the females of this new species to those of <i>C. drepane</i> <b>sp. nov.</b> (Ancient Greek ending “-opsis” means “having the appearance of…”); adjective.</p> <p> <b>Diagnosis.</b> Females distinguished from those of all other <i>Corythalia</i> species by the combination of the following characters: epigynal windows (W) oval, but only about 1.25 x longer than broad (Figs 1B, 13A, 71 G–I); secondary spermathecae (SS) approximately round, clearly smaller than primary spermathecae (PS), less than 3/4 the diameter of PS and connective ducts between SS and PS medially longitudinally not in contact with each other, but from distalmost to proximalmost section clearly diverging (Figs 13B, 75 J–L); copulatory ducts short, but recognisable (Figs 13B, 75 J–L).</p> <p> <b>Description. Male:</b> unknown.</p> <p> <b>Female</b> (measurements of holotype first, those of paratypes as range in parentheses; for spination pattern states of holotype first, those of paratypes in parentheses in the sequence of frequency): total length 5.9 (5.6–5.9), carapace length 2.2 (2.2–2.5), maximal carapace width 1.5 (1.5–1.6), width of eye rectangle 1.3 (1.3–1.5), opisthosoma length 2.9 (2.4–2.9), opisthosoma width 1.9 (1.6–1.9), fovea length 0.17 (0.17–0.21). EYES: AME 0.45 (0.45– 0.48), ALE 0.28 (0.28–0.32), PME 0.07 (0.07–0.08), PLE 0.23 (0.23–0.25), AME–AME 0.04, AME–ALE 0.03 (0.03–0.04), PME–PME 1.17 (1.17–1.26), PME–PLE 0.19 (0.19–0.22), ALE–PLE 0.53 (0.53–0.60), PLE–PLE 0.94 (0.94–1.04), clypeus height at AME 0.15 (0.15–0.19), clypeus height at ALE 0.44 (0.44–0.49). Cheliceral furrow with 1 promarginal and 1 retromarginal teeth. SPINATION: palp: no spines. Legs: femur I 1300 (1300, 1300{1400}), II 1300, III 1500 (1400, 1400), IV 0400 (0400, 0500); patella I–II 1000, III–IV 1010; tibia I 2002 (2002, 2003) II 2002 {2003} (2003, 1003), III 2023 (2123, 1123), IV 1022 {1023} (1023, 0023); metatarsus I–II 2004, III 3033 (3034, 3034), IV 3124{3134} (4134, 3134). MEASUREMENT OF PALP AND LEGS: palp 1.7 (1.7–2.1) [0.6 (0.6–0.7), 0.3 (0.3–0.4), 0.3 (0.3–0.4), 0.5 (0.5–0.6)], I 3.3 (3.3–3.8) [1.0 (1.0–1.2), 0.6 (0.6–0.7), 0.7 (0.7–0.8), 0.6 (0.6–0.7), 0.4], II 3.2 (3.2–3.6) [1.0 (1.0–1.2), 0.6, 0.6 (0.6–0.8), 0.6, 0.4], III 4.0 (4.0–4.3) [1.3 (1.3–1.5), 0.6 (0.6–0.7), 0.8, 0.8, 0.5], IV 4.2 (4.2–4.7) [1.3 (1.3–1.5), 0.6 (0.6–0.7), 0.9 (0.9–1.0), 0.9 (0.9–1.0), 0.5]. LEG FORMULA: 4312. COPULATORY ORGAN: epigyne with oval epigynal windows (but only slightly elongated and anteriorly converging), anterior margins of W medially not reaching each other (anterior gap approximately as long as width of septum) (Figs 1B, 13A, 71 G–I); septum of W quite broad (Figs 1B, 13A) and anteriorly distinctly diverging. Epigynal field clearly broader than long; structures of vulva visible through epigynal cuticle (Figs 1B, 13A, 71 G–I). Vulva with compact oval primary spermathecae (PS) with transversal (slightly diagonal) orientation (Figs 13B, 75 J–L); secondary spermathecae (SS) approximately round, with heads of spermathecae located posteriorly (Figs 13 B–C, 75J–L). Connective ducts between both spermathecae (DST) quite narrow, running diagonally from antero-lateral to postero-medial and meeting PS antero-medially. Copulatory ducts short and with transversal direction. Fertilisation ducts arising centro-anteriorly on primary spermathecae, bent and directed laterally or slightly postero-laterally (Figs 13 B–C, 75J–L). COLOURATION: see genus description for conservative aspects. Carapace dark red-brown (Fig. 61F). Legs brown to red-brown, except for some articles being lighter (see genus description) (Fig. 61F). Opisthosoma like noted in genus description under general dorsal colouration, except for chevron-like patch in central band missing (at least not recognisable) and anteriormost band just slightly broader than central and recurved, central band may also slightly recurved (Fig. 61F).</p> <p> <b>Intraspecific variation of female copulatory organs.</b> Female holotype with chalice-shaped anterior section of septum (Fig. 13A), not so in paratypes (Figs 1B, 71 H–I). Epigynal field in paratype F-3 (Fig. 71I) clearly more distinctly developed (darker) and slightly longer than in other females (Figs 1B, 13A, 71 G–H). In paratype F-2 primary spermathecae being visibile through cuticle of epigynal windows located slightly further anteriorly (Figs 1B, 71H) than in remaining female types (Figs 13A, 71G, 71I). In holotype (Figs 13B, 75J) and paratype F-2 (Fig. 75K) secondary spermathecae reaching further laterally than in paratype F-3 (Fig. 75L). Primary spermathecae in F-2 (Fig. 75K) are slightly smaller than in remaining females (Figs 13B, 75J, 75L). Connective ducts in holotype (Figs 13B, 75J) slightly longer than in paratypes (Figs 75 K–L).</p> <p> <b>Remarks.</b> Regarding the very similar copulatory organs of female <i>C. drepane</i> <b>sp. nov.</b> it is well conceivable that this and the present species are closely related. It remains to be seen if males of <i>C. drepanopsis</i> <b>sp. nov.</b>, which are still unknown, will corroborate this prediction of a close relationship in having as well very similar copulatory organs (palps) as those of <i>C. drepane</i> <b>sp. nov.</b></p> <p> <b>Distribution.</b> Known only from the type locality in Acre, Brazil.</p>Published as part of <i>Bayer, Steffen, Höfer, Hubert & Metzner, Heiko, 2020, Revision of the genus Corythalia C. L. Koch, 1850, part 1: Diagnosis and new species from South America (Araneae: Salticidae: Salticinae: Euophryini), pp. 1-144 in Zootaxa 4806 (1)</i> on pages 27-28, DOI: 10.11646/zootaxa.4806.1.1, <a href="http://zenodo.org/record/3927380">http://zenodo.org/record/3927380</a>
On the structure and applications of the Bondi–Metzner–Sachs group
No full text This work is a pedagogical review dedicated to a modern description of the Bondi–Metzner–Sachs (BMS) group. Minkowski space-time has an interesting and useful group of isometries, but, for a generic space-time, the isometry group is simply the identity and hence provides no significant informations. Yet symmetry groups have important role to play in physics; in particular, the Poincaré group describing the isometries of Minkowski space-time plays a role in the standard definitions of energy-momentum and angular-momentum. For this reason alone it would seem to be important to look for a generalization of the concept of isometry group that can apply in a useful way to suitable curved space-times. The curved space-times that will be taken into account are the ones that suitably approach, at infinity, Minkowski space-time. In particular we will focus on asymptotically flat space-times. In this work, the concept of asymptotic symmetry group of those space-times will be studied. In the first two sections we derive the asymptotic group following the classical approach which was basically developed by Bondi, van den Burg, Metzner and Sachs. This is essentially the group of transformations between coordinate systems of a certain type in asymptotically flat space-times. In the third section the conformal method and the notion of “asymptotic simplicity” are introduced, following mainly the works of Penrose. This section prepares us for another derivation of the BMS group which will involve the conformal structure, and is thus more geometrical and fundamental. In the subsequent sections we discuss the properties of the BMS group, e.g. its algebra and the possibility to obtain as its subgroup the Poincaré group, as we may expect. The paper ends with a review of the BMS invariance properties of classical gravitational scattering discovered by Strominger, that are finding application to black hole physics and quantum gravity in the literature. </jats:p
Fermi surface fluctuations and breakdown of Fermi liquid behavior
No full textElectron-electron interactions can induce Fermi surface deformations which break the point-group symmetry of the crystal structure of the system. In the vicinity of such a "Pomeranchuk instability" the Fermi surface is easily deformed by anisotropic perturbations, and exhibits enhanced collective fluctuations. We analyze Fermi surface fluctuation effects in a two-dimensional electron system on a square lattice in the vicinity of a Pomeranchuk instability with d-wave symmetry. At a quantum critical point d-wave density correlations and the dynamical forward scattering interaction diverge with a dynamical exponent z = 3. The singular forward scattering leads to large self-energy corrections, which destroy Fermi liquid behavior over the whole Fermi surface except near the Brillouin zone diagonal. The contribution from classical fluctuations to the self-energy spoils omega/T scaling in the quantum critical regime. We discuss to what extent d-wave Fermi surface fluctuations may play a role in cuprate superconductors
FIGURE 16. Corythalia parva, specimens from Brazil. A–B in Revision of the genus Corythalia C.L. Koch, 1850, part 1: Diagnosis and new species from South America (Araneae: Salticidae: Salticinae: Euophryini)
No full textFIGURE 16. Corythalia parva, specimens from Brazil. A–B Male lectotype, left palp (A ventral view; B retrolateral view); C Male paralectotype M-3, left palp (ventral view). D–F Female paralectotype, epigyne (D ventral view; E vulva, dorsal view; F schematic course of internal duct system).Published as part of Bayer, Steffen, Höfer, Hubert & Metzner, Heiko, 2020, Revision of the genus Corythalia C.L. Koch, 1850, part 1: Diagnosis and new species from South America (Araneae: Salticidae: Salticinae: Euophryini), pp. 1-144 in Zootaxa 4806 (1) on page 34, DOI: 10.11646/zootaxa.4806.1.1, http://zenodo.org/record/392738
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Contribution of APOBEC3G/F Activity to the Development of Low-Abundance Drug-Resistant HIV-1 variants.
No full textPlasma drug-resistant minority HIV-1 variants (DRMV) increase the risk of virological failure to first-line NNRTI antiretroviral therapy (ART). The origin of DRMVs in ART-naive patients, however, remains unclear. In a large pan-European case-control study investigating the clinical relevance of pre-existing DRMVs using 454 pyrosequencing, the six most prevalent plasma DRMVs detected corresponded to G-to-A nucleotide mutations (V90I, V106I, V108I, E138K, M184I and M230I). Here, we evaluated if such DRMVs could have emerged from APOBEC3G/F activity. Out of 236 ART-naïve evaluated subjects, APOBEC3G/F hypermutation signatures were detected in plasma viruses of 14 (5.9%) individuals. Samples with minority E138K, M184I, and M230I mutations, but not those with V90I, V106I, or V108I were significantly associated with APOBEC3G/F activity (Fisher's p0.5% of sample sequences with an APOBEC3G/F signature. Mutations E138K, M184I and M230I co-occurred in the same sequence as APOBEC3G/F signatures in 3/9 (33%), 5/11 (45%) and 4/8 (50%) of samples, respectively; such linkage was not found for V90I, V106I or V108I. In-frame STOP codons were observed in 1.5% of all clonal sequences; 14.8% of them co-occurred with APOBEC3G/F signatures. APOBEC3G/F-associated E138K, M184I and M230I appeared within clonal sequences containing in-frame STOP codons in 2/3 (66%), 5/5 (100%) and 4/4 (100%) of the samples. In a reanalysis of the parent case-control study, presence of APOBEC3G/F signatures was not associated with virological failure. In conclusion, the contribution of APOBEC3G/F editing to the development of DRMVs is very limited and does not affect the efficacy of NNRTI ART
Franz Metzner i Ziemia Liberecka
No full textThe article, written on the occasion of the 150th anniversary of the birth of the German-Czech sculptor Franz Metzner (November 18, 1870), focuses on Metzner‘s ties to northern Bohemia and Liberec, his sculptural and personal ties to the local environment. The text is accompanied by an edition of Metzner‘s correspondence, which draws from the surviving copiers from 1906–1918, stored in the Germanisches Nationalmuseum in Nürnberg, Abteilung Deutsches Kunstarchiv. In addition to mentions of the Liberec fountain, a number of letters has been preserved on the creation of a monument to Heinrich von Liebieg for Liberec, which finally not realized. The only work done for the Liberec (Reichenberg) region and the Frýdlant (Friedland) region, respectively, was a hundred-circle portrait relief for the monument to Emperor Joseph II, created in 1912 and lost today. In this context, the Raspenava (Raspenau) painter Franz Wenzel Jäger, Metzner‘s longtime friend, also plays an important role, to whom letters concerning non-artistic matters are also attached.Der deutschböhmische Bildhauer Franz Metzner (18. November 1870, Wscherau/Všeruby u Plzně – 24. März 1919, Berlin) stellte sich in Nordböhmen durch seine Teilnahme an der Deutschböhmischen Ausstellung 1906 in Reichenberg vor, für die er einen figürlichen Brunnen vor dem Hauptausstellungspavillon schuf. Bei dieser Gelegenheit präsentierte er zudem in Zusammenarbeit mit dem Architekten Josef Zasche sein bisheriges Schaffen erstmals in Böhmen und zwar in einem der Flügel des Kunstpavillons. Damit zeigte er sich im Reichenberger Kontext als Repräsentant der im mitteleuropäischen Raum fortschrittlichen künstlerischen Ideen der Wiener Sezession. Obwohl nach dem Ende der Ausstellung eine Aufstellung von Metzners Brunnen vor dem Reichenberger Rathaus geplant war, kam es zu Lebzeiten des Künstlers nicht zur Umsetzung. Dies geschah erst 1925, sechs Jahre nach Metzners Tod. Ein weiteres für Reichenberg vorgesehenes Werk, ein Denkmal für den Mäzen und Textilunternehmer Heinrich von Liebieg, wurde 1916 nach mehrjährigen Vorbereitungen auf einen späteren Zeitraum verschoben. Durch den Tod des Künstlers 1919 kam es nicht mehr zur Realisierung. Franz Metzners einziges Werk in der Region Reichenberg war ein im Sommer 1913 enthülltes Relief mit dem Bildnis Kaiser Josephs II . für das Dorf Ringenhain/Větrov bei Friedland/Frýdlant. Verdankt wird es einem Freund Metzners, dem Raspenauer Maler Franz Wenzel Jäger, der dem Ringenhainer Lehrer Josef Sedlak den Kontakt zum Bildhauer vermittelte. Dieser schuf nicht nur das Relief, sondern entwarf das gesamte Denkmal und wählte persönlich den Ort für seine Aufstellung aus. In der erhaltenen Korrespondenz im Deutschen Kunstarchiv des Germanischen Nationalmuseums in Nürnberg enthalten zwei Bände Briefabschriften sowie authentische Zeugnisse von F. Metzner, die sich auf die genannten Kunstwerke beziehen. Darüber hinaus befasst sich die Korrespondenz auch mit ganz persönlichen Angelegenheiten. Seit der Reichenberger Ausstellung bis 1916 spielte die Zusammenarbeit mit dem aus Gablonz/ Jablonec stammenden Josef Zasche eine wichtige Rolle in Metzners Arbeit. Diese Kooperation ist in den erwähnten Briefwechseln vielfältig dokumentiert, verdient jedoch eine gesonderte Bearbeitung, da sich die meisten daraus hervorgegangenen Werke außerhalb des Territoriums Nordböhmens befinden.Rzeźbiarz czesko – niemiecki, Franz Metzner (18. 11. 1870 Všeruby koło Pilzna / Wscherau – 24. 3. 1919 Berlin) zaprezentował się w środowisku Czech Północnych przede wszystkim swoim udziałem na Wystawie Niemców czeskich (Deutschböhmische Ausstellung) w L ibercu w roku 1906, ze względu na którą wykonał on fontannę figuralną przed głównym pawilonem wystawowym. Przy tej okazji w jednym ze skrzydeł pawilonu sztuki po raz pierwszy w C zechach we współpracy z architektem Josefem Zaschem przedstawił również swoją dotychczasową twórczość. W środowisku libereckim przedstawił się więc jeden z artystów, który prezentował w środowisku środkowoeuropejskim ówczesne pomysły progresywnej secesji wiedeńskiej. Pomimo tego, że po zakończeniu wystawy planowano zainstalować fontannę w mieście przed ratuszem, jednak nie zostało to wykonane w Libercu za życia artysty. Doszło do tego aż w roku 1925, sześć lat po śmierci Metznera. Również następna przygotowywana praca dla Liberca, pomnik protektora i przedsiębiorcy przemysłu włókienniczego, Heinricha von Liebiega, w roku 1916 została przesunięta po kilku latach przygotowań na okres późniejszy. Ze względu na zgon artysty w roku 1919 nie zostało to już zrealizowane. Jedyną pracą Franza Metznera na Ziemi Libereckiej został relief z podobizną cesarza Józefa II . w miejscowości Větrov koło Frýdlantu v Čechách, który odsłonięto latem 1913 roku. Zasługę o wykonanie dzieła miał przyjaciel Franza Metznera, raspenavski malarz, Franz Wenzel Jäger, który przekazał větrovskiemu nauczycielowi, Josefowi Sedlakowi, kontakt do rzeźbiarza. Wykonał on nie tylko relief, ale również cały kompleks pomnika i osobiście wybrał przestrzeń na jego umiejscowienie. W Deutsches Kunstarchiv przy Germanisches Nationalmuseum w Norymberdze, znajdują się w dochowanej korespondencji o tych faktach w dwóch tomach kopii archiwalnych z autentycznym poświadczeniem F. Metznera, dokumenty dotyczące konkretnych wspominanych dzieł artystycznych. Oprócz tego wspomniana korespondencja zajmuje się też zupełnie osobistymi kwestiami. Od wystawy libereckiej aż do roku 1916 znaczną rolę w twórczości Metznera zajmuje współpraca z rodakiem jabloneckim, architektem Josefem Zaschem. Jest ona bogato dokumentowana we wspomnianych kopiach archiwalnych, jednak zasługuje ona na samodzielne opracowanie, ponieważ większość dzieł, które powstały dzięki tej współpracy, znajduje się poza obszarem Czech Północnych
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
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