1,010 research outputs found
Statistical Analysis of Energization Overvoltages in EHV Hybrid OHL-Cable Systems
No full textEnergization overvoltages are among the severest overvoltages stressing insulations of EHV power system components. Since these overvoltages have a statistical nature, the insulation level should be determined with the use of a statistical approach by which the distribution of overvoltages is calculated. Literature has properly studied the distribution of energization overvoltages in purely OHL or cable systems, but such a study is not available for hybrid systems consisting of both OHLs and cables. It is expected that the overvoltage distributions change substantially when both OHLs and cables are used in a transmission line. This paper tackles this issue by analyzing the overvoltage distributions due to the energization of a 380 kV hybrid OHL-Cable circuit, in which the cable length is variable. The study includes various sensitivity analyses to find out the impact of system parameters and topology on overvoltages. By the statistical analysis, it has been discovered that energization overvoltages of a hybrid OHL-Cable circuit are higher than those of a fully-cable circuit and very likely lower than those of a fully-OHL circuit with the same transmission lengths.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Intelligent Electrical Power GridsEEMS - Genera
FOR MONEY OR LIBERTY? THE POLITICAL ECONOMY OF MILITARY DESERTION AND REBEL RECRUITMENT IN THE SYRIAN CIVIL WAR
No full textFrom disaffection to desertion: How networks facilitate military insubordination in civil conflict
No full textScholarship on intrastate conflict and civil-military relations has largely ignored individual desertions during civil war. We show that high-risk behavior, such as desertion, is best thought of as coordinated action between individual decision-makers and their strong network ties. Soldiers hold preexisting opinions on whether high-risk action is worthwhile, but it is their networks that persuade them to act. Specifically, it is the content of strong network ties (rather than their mere existence) and the ability to interpret information (rather than the presence of information), which helps explain individual action under extreme risk. Our thick empirical narrative is based on substantial fieldwork on the Syrian conflict and contributes to debates on military cohesion, intrastate conflict trajectories, and the power of networks in catalyzing high-risk behavior
Predictors of Employment Status Among Adults With Autism Spectrum Disorder
No full textAbstract
Date Presented 3/31/2017
Multivariate logistic regression analyses of a national employment survey of adults with autism spectrum disorder (ASD) revealed disability disclosure and higher education increased the participants’ likelihood of employment. This information may prove useful to occupational therapists working with adults with ASD.
Primary Author and Speaker: Alisha Ohl</jats:p
Ovalofemora monstruosa Jepson & Khramov & Ohl 2018, comb. nov.
No full textOvalofemora monstruosa (Khramov, 2013) comb. nov. 2013 Mesithone monstruosa Khramov, p. 224 (Mesithoninae) 2015 Karataumantispa monstruosa Jepson, p. 426 (Mesomantispinae) Remarks. Ovalofemora monstruosa was originally placed within the genus Mesithone Panfilov, 1980 (Khramov, 2013). It was later removed from Mesithone and placed in Karataumantispa along with Mesithone carnaria Khramov, 2013 (Jepson, 2015). The placement of monstruosa within Karataumantispa was tentative, due to the poor preservation of the wing venation and the possession of a different foreleg morphology compared to K. carnaria (see Jepson, 2015). The discovery of Ovalofemora abbottae gen. et sp. nov., which shares a similar foreleg morphology (oval shaped, stout coxa, trochanter, femur, and hooked prostrate setae on tibia), in addition to similar venation, justified its removal from Karataumantispa and placement within a new genus, Ovalofemora gen. nov. The differences between the foreleg morphology of the Karatau mesomantispines are shown in Figure 3.Published as part of Jepson, James E., Khramov, Alexander V. & Ohl, Michael, 2018, New Mesomantispinae (Insecta: Neuroptera: Mantispidae) from the Jurassic of Karatau, Kazakhstan, pp. 563-574 in Zootaxa 4402 (3) on page 570, DOI: 10.11646/zootaxa.4402.3.9, http://zenodo.org/record/120979
OHL cells express both KLF4 and BLIMP1.
No full text<p>H&E analysis (Image: 40X), and immunohistochemistry analysis was performed on a paraffin-embedded, formalin-fixed biopsy of an oral hairy leukoplakia (OHL) lesion using antibodies directed against Z, BMRF1, KLF4 and BLIMP1 as indicated (Images: 100x of region boxed in H & E stain). Examples of OHL cells, positively staining for each of these proteins, are indicated by black arrows.</p
Sphex pulawskii Dörfel & Ohl 2022, sp. nov.
No full textSphex pulawskii sp. nov. urn:lsid:zoobank.org:act: 0BD5A35B-90FD-4CB0-9340-394AE7E5D6FB Figs 86–87, 91 (blue) Differential diagnosis Within the nigrohirtus group, females of S. pulawskii sp. nov. can be recognized through their silvery appressed setae posterolaterally on the collar and silvery appressed and erect setae at the posterior propodeal margin, in combination with the remaining erect propodeal setae being black (Fig. 86). Those of S. incomptus have most of the propodeum covered with silvery setae (Fig. 85), whereas female S. nigrohirtus have uniformly black mesosomal setae (Fig. 84). Males can be more difficult to identify, as some specimens of S. nigrohirtus share the combination of erect propodeal setae that are black on the enclosure and silvery at the posterior margin. The easiest characteristic to distinguish them is the absence of cyan iridescence on the wings of S. pulawskii sp. nov., being rich purple instead (Fig. 87). Etymology We dedicate this species to Dr Wojciech J. Pulawski, who collected some of the specimens and who is responsible for creating and maintaining the amazing Catalog of Sphecidae that has made our work much more manageable. Material examined Holotype BENIN – Atakora Department • ♂; Niaro; [10°12ʹ02.2ʺ N, 1°36ʹ59.9ʺ E]; 2 Jul.1969; J. Hamon leg.; MNHN. Paratypes AFRICA • 1 ♀; 2 Feb. 1894; ZMB. CAMEROON – Southwest Region • 1 ♀; Victoria [now Limbe]; [4°01ʹ N, 9°13ʹ E]; P. Preuss leg.; ZMB • 1 ♀; 12 mi. SW of Loum, Mungo Forest Camp; [4°34ʹ05ʺ N, 9°38ʹ09ʺ E]; 22 Oct. 1966; E.S. Ross and K. Lorenzen leg.; CAS. DEMOCRATIC REPUBLIC OF THE CONGO – North Kivu • 1 ♀; Mutsora; [0°19ʹ20ʺ N, 29°44ʹ43ʺ E]; 22 Apr. 1905; Hackars leg.; MRAC. GHANA – Eastern Region • 2 ♀♀; Aburi; [5°50ʹ52ʺ N, 0°10ʹ28ʺ W]; Dec. 1941; K.M. Guichard leg.; BMNH. LIBERIA – Bong County • 1 ♀; 10 mi. NE of Gbanka [Gbarnga]; [7°09ʹ30ʺ N, 9°27ʹ07ʺ W]; 11Aug.1966; E.S. Ross and K. Lorenzen leg.; CAS. – Gbarpolu County • 1 ♀; Kolobanu [Kolobani]; [7°12ʹ07ʺ N, 9°52ʹ38ʺ W]; 19 Oct. 1926; J. Bequaert leg.; MRAC. – Lofa County • 1 ♀; 36 mi. S of Voinjama; [7°56ʹ44ʺ N, 9°32ʹ10ʺ W]; 13 Aug. 1966; E.S. Ross and K. Lorenzen leg.; CAS. NIGERIA – Cross River State • 1 ♀; Obudu Cattle Ranch; [6°22ʹ N, 9°22ʹ E]; 3 May 1973; J.T. Medler leg.; BMNH. – Edo State • 1 ♂; Benin; [6°20ʹ17ʺ N, 5°37ʹ32ʺ E]; 30 Jul. 195?; T. Davey leg.; BMNH. – Oyo State • 1 ♀; 10 mi. N of Ibadan; [7°37ʹ15ʺ N, 3°55ʹ08ʺ E]; 9 Sep. 1966; E.S. Ross and K. Lorenzen leg.; CAS • 1 ♂; Olekemeji, Ibadan; [7°23ʹ N, 3°53ʹ E]; J.C. Bridwell leg.; USNM. REPUBLIC OF CÔTE D’IVOIRE • 1 ♀; “ Samplen ”; 1910; A. Chevalier leg.; MNHN. – Lagunes District • 1 ♀; 40 km NW of Abidjan; [5°46ʹ27ʺ N, 4°07ʹ34ʺ W]; 6 Jan. 1991; W.J. Pulawski leg.; CAS. SIERRA LEONE • 1 ♀; MNHN. TOGO – Centrale Region • 1 ♀; Bismarckburg [near Yégué]; [8°10ʹ32.74ʺ N, 0°41ʹ09.42ʺ E]; 20 Jul.–20 Sep. 1890; R. Büttner leg.; ZMB • 1 ♀; same collection data as for preceding; ZMB. Description Female SIZE. 20.8–26.9 mm. COLOR. Black except for the following, which are ferruginous: basal half of mandible and free clypeal margin. Wings fuscous, with purple iridescence. VESTITURE. Appressed setae on clypeus, paraocular area, collar, posterolaterally on scutum and at posterior propodeal margin silvery, on remainder of scutum and propodeal enclosure black. Erect setae on clypeus, frons, collar, scutum and propodeal enclosure black, on posterior margin of propodeum silvery. Central third of clypeus glabrous. Scutellum densely and coarsely pubescent. STRUCTURE. Free clypeal margin with broad, gently notched, shovel-like process medially, not markedly stepped above. Clypeus with notable indentation in lower center and longitudinal carina above. Scutellum convex. Metanotum not raised, not markedly bituberculate. 2 nd recurrent vein joins markedly proximal from interstitium between submarginal cells II and III. Propodeal enclosure without any notable ridges. Foretarsomere I 2.8–2.9 × length of antepenultimate spine. Petiole length 1.8–2.2× its medial width. Male SIZE. 20.6–21.7 mm. COLOR. Black except for ferruginous stripe in center of mandible. Wings slightly fuscous, with markedly purple iridescence. VESTITURE. Appressed setae on clypeus, paraocular area, collar and posterior margin of propodeum silvery, on scutum and propodeal enclosure black. Erect setae on clypeus, paraocular area, collar and scutum black, on propodeal enclosure silvery intermixed with black, on posterior margin of propodeum silvery. Lower center of clypeus glabrous. Scutellum densely and coarsely pubescent. Metasomal sterna II–VI with increasingly dense fringes of black setae. STRUCTURE. Free clypeal margin simple. Clypeus with longitudinal carina in upper center. Scutellum convex. Metanotum not raised, not bituberculate. 2 nd recurrent vein joins markedly proximal from interstitium between submarginal cells II and III. Propodeal enclosure without any notable ridges. Posterior margin of metasomal tergum VII slightly notched. Posterior margin of metasomal sternum VII simple, of metasomal sternum VIII concavely emarginate. Penis valvae without conspicuous modifications. Petiole length 2.2–2.7× its medial width. Flagellomere V with narrow placoid covering its proximal four-fifths and tapering medially or distally. Variation Unknown. Distribution Western Africa. Remarks After careful consideration, we came to the conclusion that while the distinguishing characters of this species are very subtle, its classification as a separate taxon is warranted nonetheless, the reasons for which are explained below. Our studies show that the similar S. nigrohirtus is restricted to the southern and eastern parts of the African continent. However, S. pulawskii sp. nov. is found in western Africa, and it is characterized by having the appressed and erect setae on the propodeum, posterolaterally of the enclosure, colored silvery instead of black. Additionally, western females also have the appressed setae silvery posteriorly on the collar and posterolaterally on the scutum, whereas those from eastern and southern Africa have them black. Males, however, are not so easy to define. The color of the appressed setae posterolaterally on collar, scutum and propodeum and the erect setae on the posterior propodeal margin varies between black and silvery in S. nigrohirtus even among specimens from the same locality. There is one character that, although difficult to objectively define, is obvious in western African males: the iridescence on the wings. In these, it is uniformly purple, resembling the color Byzantium, whereas the tone is more akin to Spanish violet and always contains shades of cyan in S. nigrohirtus.Published as part of Dörfel, Thorleif H. & Ohl, Michael, 2022, The wasp genus Sphex in Sub-Saharan Africa (Hymenoptera: Sphecidae), pp. 1-170 in European Journal of Taxonomy 796 (1) on pages 98-100, DOI: 10.5852/ejt.2022.796.1665, http://zenodo.org/record/629944
Investigation of Statistical Distribution of Energization Overvoltages in 380 kV Hybrid OHL-Cable Systems
No full textSwitching operations in power systems can produce significant overvoltages under specific circumstances. With the increasing application of underground cables in transmission systems, the statistical distribution of energization overvoltages is expected to change substantially due to the different electrical characteristics of cables and OHLs. Therefore, it is crucial to perform an insulation coordination study by analysis of the statistical distribution of energization overvoltages. This paper presents a statistical switching analysis on a hybrid OHL-Cable circuit to investigate how such hybrid circuits can affect the distribution of overvoltages. The literature has addressed the distribution of energization overvoltages only for OHLs or cables, but such an study is not available for hybrid systems consisting of OHLs and cables combined. The study is carried out for different cable lengths in the case study to identify how an increasing cable share in the circuit influences the overvoltages distribution due to no-load energization. Moreover, the impact of symmetrical and asymmetrical circuit structures is also addressed. The study is carried out on a distributed frequency-dependent parameter model of the Dutch 380 kV grid in PSCAD/EMTDC.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Intelligent Electrical Power GridsEEMS - Genera
Decentralized Deep Reinforcement Learning for a Distributed and Adaptive Locomotion Controller of a Hexapod Robot
No full textSchilling M, Konen K, Ohl FW, Korthals T. Decentralized Deep Reinforcement Learning for a Distributed and Adaptive Locomotion Controller of a Hexapod Robot. In: 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). IEEE; 2020: 5335-5342
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