927 research outputs found
A Biomimetically Derived Method for Control of Span-Wise Morphing Wings
© 2022 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. This is the accepted manuscript version of a conference paper which has been published in final form at https://doi.org/10.2514/6.2022-1986The development of novel morphing wings follows common milestones. This work presents the modelling and control of the recently proposed avian wing span-wise morphing concept. The concept primarily consists of three structural members heavily mimicking the skeletal structure birds employ for flight. This structure is actuated, through the range of motion achievable by avian, with the integration of pneumatic artificial muscles (PAMs). Arranged in antagonistic pairs, the PAMs actuate an effective shoulder joint between the aircraft and wing through 90â°. As well as two joints along the wing through 110â°, allowing a span-wise reduction of 75% the fully extended span. This adaptive structure is capable of supporting several different aerofoil geometries for application specific aircraft. Initially proposed with a biomimetic derived wing profile more traditional and predictable NACA aerofoils have been applied. In this paper the avian wing span-wise morphing concept is modelled and with the application of inverse kinematics a control system is derived to allow simplified span-length positioning. Similarly, desired wing area is also presented as an input for the system. The model is based on PAM force models to individually model the pneumatic system driving each joint. The mechanical system of each joint is subsequently used to produce a direct kinematic model for wing tip position, and the inverse determined for control. The validity of both the model and system are experimentally tested on a fixed semi-span prototype rig of the morphing concept. Feedback is then introduced. Potentiometers are embedded into each joint to provide joint angle feedback. The tuning of the system is then presented for different dynamic responses. Alongside this development experiments have been conducted into the kinematics avian employ in flight and the flight dynamics they enable. These results are presented and directly applied as parameters for the proposed system. Span morphing retraction and extension rates determined from in vivo flight data of avian, including the Common buzzard (Buteo buteo) and Harris Hawk (Parabuteo unicinctus), are achieved using the avian wing span-wise morphing concept and the proposed control system. These dynamics are used to infer the parameters of an aircraft with the concept wing used as control surfaces
The New Minnesotans: Profile of West Central Minnesota
In 2005, The Center for Small towns, together with the University of Minnesota West Central Regional Sustainable Development Partnership, began the New Minnesotans project that aimed to help identify underrepresented racial and ethnic groups who are new residents of West Central Minnesota. The project\u27s goal was to find ways to support the needs of these groups and to encourage their abilities. Twelve counties were involved in the study done for the project: Big Stone,Chippewa, Douglas, Grant, Kandiyohi, Lac qui Parle, Pope, Renville, Stevens, Swift, Traverse, and Yellow Medicine.https://digitalcommons.morris.umn.edu/cst/1001/thumbnail.jp
SMART Vaccines 2.0 decision-support platform : A tool to facilitate and promote priority setting for sustainable vaccination in resource-limited settings
Funding Information: Supported by Gavi and the Bill and Melinda Gates Foundation, a number of international organisations have offered capacity-building support to establish NITAGs. While greater emphasis was initially placed on fulfilling process indicators for establishing NITAGs, more recent efforts have sought to advance functional capabilities associated with EIDM, most notably by Agence de MĂ©decine PrĂ©ventive (AMP), the International Vaccine Institute and The Sabin Vaccine Institute.13 14 These programmes have additionally leveraged technical assistance from WHO and its regional offices, PATH and the US Centers for Disease Control and Prevention.15 16 Funding Information: The UNITAG sought technical assistance from AMPâs Supporting Independent Vaccine Advisory Committees (SIVAC) Initiative,14and engaged in piloting the SMART Vaccines 2.0 platform supported by the Fogarty International Center at the US National Institutes of Health (NIH). A description of the NITAG process is given elsewhere.24 33 Funding Information: Funding This work was supported by the Fogarty International Center, National Institutes of Health, USA. Publisher Copyright: © 2020 Author(s). Published by BMJ.Peer reviewedPublisher PD
Supervised exercise training improves cardiorespiratory fitness and reduces perioperative risk in peripheral artery disease patients with intermittent claudication
Chromophore-labelled, luminescent platinum complexes: syntheses, structures, and spectroscopic properties
Ligands based upon 4-carboxamide-2-phenylquinoline derivatives have been synthesised with solubilising octyl hydrocarbon chains and tethered aromatic chromophores to give naphthyl (HL2), anthracenyl (HL3) and pyrenyl (HL4) ligand variants, together with a non-chromophoric analogue (HL1) for comparison. 1H NMR spectroscopic studies of the ligands showed that two non-interchangeable isomers exist for HL2 and HL4 while only one isomer exists for HL1 and HL3. Supporting DFT calculations on HL4 suggest that the two isomers may be closely isoenergetic with a relatively high barrier to exchange of ca. 100 kJ molâ1. These new ligands were cyclometalated with Pt(II) to give complexes [Pt(L1â4)(acac)] (acac = acetylacetonate). The spectroscopically characterised complexes were studied using multinuclear NMR spectroscopy including 195Pt{1H} NMR studies which revealed ÎŽPt ca. â2785 ppm for [Pt(L1â4)(acac)]. X-ray crystallographic studies were undertaken on [Pt(L3)(acac)] and [Pt(L4)(acac)], each showing the weakly distorted square planar geometry at Pt(II); the structure of [Pt(L3)(acac)] showed evidence for intermolecular PtâPt interactions. The UV-vis. absorption studies show that the spectral profiles for [Pt(L2â4)(acac)] are a composite of the organic chromophore centred bands and a broad 1MLCT (5d â Ï*) band (ca. 440 nm) associated with the complex. Luminescence studies showed that complexes [Pt(L2â4)(acac)] are dual emissive with fluorescence characteristic of the tethered fluorophore and long-lived phosphorescence attributed to 3MLCT emission. In the case of the pyrenyl derivative, [Pt(L4)(acac)], the close energetic matching of the 3MLCT and 3LCpyr excited states led to an elongation of the 3MLCT emission lifetime (Ï = 42 ÎŒs) under degassed solvent conditions, suggestive of energy transfer processes between the two states
A systematic review and meta-analysis reveals altered drug pharmacokinetics in humans during acute exposure to terrestrial high altitude- clinical justification for dose adjustment?
Objective: While physiological responses during acute ascent to terrestrial high altitude (HA) have the potential to alter the pharmacokinetics (PKs) that define absorption and disposition of medicinal drugs, there have been no systematic reviews and meta-analyses performed to date. Methods: We conducted a systematic literature search in June 2017 using NCBI PubMed, EMBASE, Web of Science, and Ovid MEDLINE databases to identify relevant observational studies. Studies were deemed eligible based on the following criteria: (1) participants: healthy, nonacclimatized male or female lowlanders (born and bred at sea level) and (2) environment: exposure to low altitude (LA, â€600 m), followed by terrestrial high altitude (HA, â€24 hours to â„2500 m), the time course specifically selected to avoid interpretive complications associated with erythrocytosis. All PK parameters were standardized to be in the same units and the weighted standardized mean difference (SMD) calculated using a combination of fixed and random effects models with heterogeneity evaluated using Ï2 and I2 statistics. Results: Of 20,840 studies reviewed, 6 prospective cohort studies (n = 75) qualified for inclusion, with participants exposed to a mean altitude of 4025 (mean) ± 380 (SD) m. We observed increases for absorption half-life (SMD: 0.40, 95% CI: 0.01â0.80, p = 0.04], elimination half-life (SMD: 0.89, 95% CI: 0.30â1.48, p = 0.003), and erythrocyte binding (SMD: 0.52, 95% CI: 0.16â0.88, p = 0.004) and reduction in clearance (SMD: â0.56, 95% CI: â1.13 to 0.00, p = 0.05). Conclusions: Collectively, these findings reveal impairments in both oral absorption and corresponding clearance of the, although limited, sample of drugs at HA that may potentially require closer patient monitoring and dose adjustments to maintain therapeutic efficacy and avoid incidental toxicity
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