1,963 research outputs found

    First Record of \u3ci\u3eDorocordulia Libera\u3c/i\u3e (Odonata: Corduliidae) in Ohio in 75 Years

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    A population of the Racket-tailed Emerald, Dorocordulia libera, was found at Singer Lake, a collection of numerous bogs in southern Summit County, Ohio. This species was previously known in Ohio from two speci­ mens collected 22 June 1924 from a bog in Geauga County. Between 8 June and 23 July 1999, 14 male and 3 female specimens were collected at Singer Lake. Notes on this species behavior and flight season in Ohio are presented

    Second Location for Two Rare Odonata in Ohio, \u3ci\u3eNannothemis Bella\u3c/i\u3e and \u3ci\u3eLadona Julia\u3c/i\u3e, (Odonata: Libellulidae) Discovered at Singer Lake Bog, Summit County, Ohio.

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    Previously the dragonflies (Odonata, Libellulidae) Ladona julia and Nannothemis bella were known in Ohio from only one extant population each: L. julia from extreme northwest Ohio in Williams County and N. bella from west-central Ohio in Champaign County. During the summer of 2000 populations of each of these species were found in close proximity to each other at Singer Lake, a wetlands complex in southern Summit County in northeastern Ohio. This new location is also home to a population of another rare Ohio dragonfly, Dorocordulia libera (Odonata, Corduliidae) that was discovered during 1999. The Singer Lake wetlands are proving to be a very significant habitat for Ohio Odonata

    Aberrant Wing Pigmentation in \u3ci\u3eLibellula Luctuosa\u3c/i\u3e Specimens From Ohio

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    Over the past few years we obtained three female Libellula luctuosa specimens, all collected in northeast Ohio, which exhibited unusually reduced wing pigmentation. The individuals were extremely difficult to identify as most keys rely heavily upon wing pigmentation for identification of many Libellula species. A description of this aberrant wing pigmentation and a photograph are provided

    364 Days: Suite for Jazz Orchestra

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    Title from PDF of title page, viewed on July 15, 2016Dissertation advisor: Reynold SimpsonVitaThesis (D.M.A.)--Conservatory of Music and Dance, University of Missouri--Kansas City, 2016364 Days: Suite for Jazz Orchestra was composed for a standard seventeen-piece (5/4/4/4) jazz orchestra. The suite is comprised of five pieces- And I Think of You; Goodnight; What Ifs; 364 Days; The Dreamer and The Realist - and were recorded for the album J.E. Chapman, 364 Days: music for large ensembles. Each movement of the suite is intended to work as a part of the larger work or out of context as an individual performance piece. The sections of the suite are connected through an "affiliated motif". Each piece is tied together through intervallic commonalities, common melodic contour, and "spirit" but are unique enough in their own individuality to posses their own personality. While the intent is for the suite to be performed as a complete work I took great effort in creating five works that could be performed separately and yet still sound complete; each piece has its own unique formal structure and distinctive rhythmic and style elements that allow them to succeed as part of a set or as an isolated work. These compositions blend modern jazz harmonies and non-traditional formal structures; staying connected to and extending the tradition of jazz composition.Title page -- ...And I think of you -- Goodnight -- What ifs -- 364 days -- The dreamer and the realis

    Electrical Cable Design for Urban Air Mobility Aircraft

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    Urban Air Mobility (UAM) describes a new type of aviation focused on efficient flight within urban areas for moving people and goods. There are many different configurations of UAM vehicles, but they generally use an electric motor driving a propeller or ducted fan powered by batteries or a hybrid electric power generation system. Transmission cables are used to move energy from the storage or generation system to the electric motors. Though terrestrial power transmission cables are well established technology, aviation applications bring a whole host of new design challenges that are not typical considerations in terrestrial applications. Aircraft power transmission cable designs must compromise between resistance-per-length, weight-per-length, volume constraints, and other essential qualities. In this paper we use a multidisciplinary design optimization to explore the sensitivity of these qualities to a representative tiltwing turboelectric UAM aircraft concept. This is performed by coupling propulsion and thermal models for a given mission criteria. Results presented indicate that decreasing cable weight at the expense of increasing cable volume or cooling demand is effective at minimizing maximum takeoff weight (MTO). These findings indicate that subsystem designers should update their modeling approach in order to contribute to system-level optimality for highly-coupled novel aircraft. Mobility (UAM) vehicles have the potential to change urban and intra-urban transport in new and interesting ways. In a series of two papers Johnson et al.1 and Silva et al.2 presented four reference vehicle configurations that could service different niches in the UAM aviation category. Of those, this paper focuses on the Vertical Take-off and Landing (VTOL) tiltwing configuration shown in Figure 1. This configuration uses a turboelectric power system, feeding power from a turbo-generator through a system of transmission cables to four motors spinning large propellers on the wings. Previous work on electric cable subsystems leaves much yet to be explored, especially in the realm of subsystem coupling. Several aircraft optimization studies1, 3, 4 only considered aircraft electrical cable weight and ignored thermal effects. Electric and hybrid-electric aircraft studies by Mueller et al.5 and Hoelzen et al.6 selected a cable material but did not investigate alternative materials. Advanced cable materials have been examined by a number of authors: Alvarenga7 examined carbon nanotube (CNT) conductors for low-power applications. De Groh8, 9 examined CNT conductors for motor winding applications. Behabtu et al.,10 and Zhao et al.11 examined CNT conductors for a general applications. There were some studies that examined the thermal effects of cables but they did not allow the cable material to change; El-Kady12 optimized ground-cable insulation and cooling subject constraints. Vratny13 selected cable material based on vehicle power demand, and required resulting cable heat to be dissipated by the Thermal Management System (TMS). None of these previous studies allowed for the selection of the cable material based on a system level optimization goal. Instead, they focused on sub-system optimality such as minimum weight, which comes at the expense of incurring additional costs for other subsystems. Dama14 selected overhead transmission line materials using a weighting function and thermal constraints. However, that work was not coupled with any aircraft subsystems like a TMS. The traditional aircraft design approach, which relies on assembling groups of optimal subsystems, breaks down when considering novel aircraft concepts like the tiltwing vehicle. In a large part, this is because novel concepts have a much higher degree of interaction or coupling between subsystems. For example, when a cable creates heat, this heat needs to be dissipated by the TMS, which needs power supplied by the turbine, and delivering the power creates more heat. The cable, the TMS, and the turbine are all coupled. A change to one subsystem will affect all the other subsystems, much to the consternation of subsystem design experts. Multidisciplinary optimization is the design approach that can address these challenges. However, to fully take advantage of this, we must change the way we think about subsystem design. Specifically, we must move away from point design, and focus on creating solution spaces. The work presented in this paper uses the multidisciplinary optimization approach with aircraft level models to study the system-level sensitivity of cable traits: weight-per-length and resistance-per-length. Additionally, we examined the effects of vehicle imposed volume constraints on these traits. This is useful for three purposes: (1) to demonstrate a framework that can perform a coupled analysis between the aircraft thermal and propulsion systems, (2) to provide a method by which future cable designs can be evaluated against each other given a system-level design goal, (3) to provide insight into what cable properties may be promising for future research. This last element is explored given the caveat that the models contained in this analysis do not represent high-fidelity systems. Thus, while we can demonstrate coupling in between systems, the exact system-level sensitivity to a given parameter may change if a subsystem model or the assumptions governing that model change. The organization of this paper is as follows, in Sec II we outline a method to combine the VTOL vehicle design and cable information in order to produce cables sensitivity studies. Results analysis and discussion are contained in Sec III. Conclusions are presented in Sec IV

    Ten New Genera of \u3cem\u3eAgathidini\u3c/em\u3e (Hymenoptera, Braconidae, Agathidinae) from Southeast Asia

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    The Agathidini (Braconidae: Agathidinae) genera of Southeast Asia are revised based on a phylogenetic analysis of COI and 28S. Ten new genera are proposed, i.e., Agathigma, Asperagathis, Chimaeragathis, Cymagathis, Liragathis, Leuroagathis, Scabagathis, Trochantagathis, Xanthagathis, and Zosteragathis. An illustrated key to the Southeast Asian genera of this tribe is presented. Species from Thailand are keyed and described for all genera of Agathidini except Bassus and Zosteragathis which have too many species for this publication and will be dealt with separately. The phylogenetic analyses indicate that Bassus s.s. is polyphyletic. However, there are no morphological characters to support this and we have retained the current concept of Bassus, which is basically those Agathidini with simple tarsal claws. Numerous new combinations are proposed based on species that are moved to the newly erected genera

    Second-Order Coverage Control for Multi-Agent UAV Photogrammetry

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    Unmanned Aerial Vehicles equipped with cameras can be used to automate image capture for generating 3D models via photogrammetry. Current methods rely on a single vehicle to capture images sequentially, or use pre-planned and heuristic imaging configurations. We seek to provide a multi-agent control approach to capturing the images required to 3D map a region. A photogrammetry cost function is formulated that captures the importance of sharing feature-dense areas across multiple images for successful photogrammetry reconstruction. A distributed second-order coverage controller is used to minimise this cost and move agents to an imaging configuration. This approach prioritises high quality images that are simultaneously captured, leading to efficient and scalable 3D mapping of a region. We demonstrate our approach with a hardware experiment, generating and comparing 3D reconstructions from image sets captured using our approach to those captured using traditional methods.Comment: 8 pages, 4 figure
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