5,034 research outputs found
In-flight total forces, moments and static aeroelastic characteristics of an oblique-wing research airplane
A low-speed flight investigation has provided total force and moment coefficients and aeroelastic effects for the AD-1 oblique-wing research airplane. The results were interpreted and compared with predictions that were based on wind tunnel data. An assessment has been made of the aeroelastic wing bending design criteria. Lateral-directional trim requirements caused by asymmetry were determined. At angles of attack near stall, flow visualization indicated viscous flow separation and spanwise vortex flow. These effects were also apparent in the force and moment data
Flight characteristics of the AD-1 oblique-wing research aircraft
The AD-1 is a low-speed oblique-wing research airplane. This report reviews the vehicle's basic flight characteristics, including many aerodynamic, stability, and control effects that are unique to an oblique-wing configuration. These effects include the change in sideforce with angle of attack, moment changes with angle of attack and load factor, initial stall on the trailing wing, and inertial coupling caused by a roll-pitch cross product of inertia. An assessment of the handling qualities includes pilot ratings and comments. Ratings were generally satisfactory through 30 deg of wing sweep but degraded with increased sweep. A piloted simulation study indicated that a basic rate feedback control system could be used to improve the handling qualities at higher wing sweeps
Flight-determined aerodynamic derivatives of the AD-1 oblique-wing research airplane
The AD-1 is a variable-sweep oblique-wing research airplane that exhibits unconventional stability and control characteristics. In this report, flight-determined and predicted stability and control derivatives for the AD-1 airplane are compared. The predictions are based on both wind tunnel and computational results. A final best estimate of derivatives is presented
Flight-determined stability and control derivatives for the F-111 Tact research aircraft
A flight investigation was conducted to provide a stability and control derivative data base for the F-111 transonic aircraft technology research aircraft. Longitudinal and lateral-directional data were obtained as functions of Mach number, angle of attack, and wing sweep. For selected derivatives, the flight results were correlated with derivatives calculated based on vehicle geometry. The validity of the angle of attack measurement was independently verified at a Mach number of 0.70 for angles of attack between 3 and 10 degrees
Forecasting electricity consumption using the second-order fuzzy time series
There is a great development of Universiti Tun Hussein Onn Malaysia (UTHM) infrastructure since its formation in 1993. The development will be accompanied by the increasing demand for electricity. Hence, there is a need to forecast UTHM electricity consumption accurately so that UTHM can plan for future energy demand and utility saving decisions. Previous studies on UTHM electricity consumption prediction have been carried out using time series models, multiple linear regression and first-order fuzzy time series (FTS). The first-order FTS yield the best accuracy among these three methods. Previous forecasting problem showed higher order FTS can yield better accuracy. Therefore, in this study, the second-order FTS with trapezoidal membership function was implemented on the UTHM monthly electricity consumption from January 2009 to December 2018 to forecast January to December 2019 monthly electricity consumption. The procedure of the FTS and trapezoidal membership function was described together with January data. The second-order FTS forecast UTHM electricity consumption better than the first-order FTS
Expansion of patient eligibility for virtual glaucoma clinics: a long-term strategy to increase the capacity of high-quality glaucoma care
AIMS: The virtual glaucoma clinic (VGC) is a well-established diagnostic pathway for delivery of glaucoma care. Current UK national guidance recommends VGCs for patients with ocular hypertension, glaucoma suspects or early glaucoma. This study evaluates whether expanded eligibility criteria, including other glaucoma phenotypes and disease stages, can deliver safe and effective care with a positive patient experience. METHODS: Records of over 8000 patients were reviewed in order to determine suitability for VGC attendance using expanded eligibility criteria. Patients with three prior consecutive visits within the glaucoma service were included. Follow-up interval, clinic type, visual acuity (VA), intraocular pressure (IOP) and visual field performance were recorded. Patient satisfaction was recorded for a sample of 118 patients. RESULTS: 2017 patients over 31 months were included. Two-thirds of eyes had ocular comorbidities, a fifth of eyes had undergone prior cataract surgery and 10% of eyes had undergone a prior laser treatment for glaucoma. After three visits, 32% of patients remained in the VGC, 42% were seen in face-to-face clinics and 25% were discharged. There were no clinically significant changes in VA, IOP and visual field performance during follow-up. 72% of patients expressed a preference to continue their care within VGCs. CONCLUSIONS: This study demonstrates that VGCs with expanded patient eligibility criteria can deliver high-quality glaucoma care that is safe, effective and with high levels of patient satisfaction. This approach provides a long-term solution to adapt delivery of glaucoma care to our expanding and ageing population
Towards unified understanding of conductance of stretched monatomic contacts
When monatomic contacts are stretched, their conductance behaves in
qualitatively different ways depending on their constituent atomic elements.
Under a single assumption of resonance formation, we show that various
conductance behavior can be understood in a unified way in terms of the
response of the resonance to stretching. This analysis clarifies the crucial
roles played by the number of valence electrons, charge neutrality, and orbital
shapes.Comment: 2 figure
Conteúdos linguísticos como subsídio à formação de professores alfabetizadores: a experiência do Brasil e de Portugal
Objetiva identificar em dois programas de formação de professores
alfabetizadores – no Brasil, Pacto Nacional pela Alfabetização na Idade Certa (Pnaic) e, em Portugal, Programa Nacional do Ensino do Português (Pnep) – os conteúdos linguísticos relacionados ao ensino da leitura que fundamentaram a atualização dos professores com vistas a compreender como as descobertas científicas penetram o campo pedagógico. Por meio de análise documental, são apresentadas, de forma resumida, a estrutura e a organização dos dois programas e os respectivos conteúdos de formação. Há muita similaridade entre os dois programas com relação à organização e às estratégias metodológicas e há diferenças importantes quanto à atualidade dos conteúdos oferecidos aos professores alfabetizadores, assim como o tempo de formação aplicado a este conteúdo. A formação linguística do professor é essencial para desenvolver competência para o ensino da língua e, por conseguinte, melhorar as habilidades de ler e escrever dos alunos do ensino fundamental.This article aims to identify the linguistic contents related to the
teaching of reading in two training programs for literacy teachers: Brazil’s
National Pact for Literacy at the Right Age (Pacto Nacional pela Alfabetização
na Idade Certa – Pnaic) and the National Program for Portuguese Teaching
(Programa Nacional do Ensino do Português – Pnep) of Portugal. The focus
is on the linguistic contents that served as foundation for the updating
of teachers, in order to understand how scientific discoveries permeate
the teaching field. Through documentary analysis, the structure and the
organization of the two programs and their respective training contents are
briefly presented. There are many similarities between the two programs,
regarding the organization and the methodological strategies; but there are
also differences in relation to the timeliness of the content offered to the
literacy teachers, as well as to the duration of the training applied to the
content. The linguistic training of teachers is essential to developing the
competence for language teaching and, therefore; for the improvement of
reading and writing skills of elementary school students.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), PortugalFundos Nacionais através da FCT (Fundação para a Ciência e a Tecnologia) e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio
An equatorial wind from the massive young stellar object S140 IRS 1
The discovery of the second equatorial ionized stellar wind from a massive
young stellar object is reported. High resolution radio continuum maps of S140
IRS 1 reveal a highly elongated source that is perpendicular to the larger
scale bipolar molecular outflow. This picture is confirmed by location of a
small scale monopolar near-IR reflection nebula at the base of the blueshifted
lobe. A second epoch of observations over a five year baseline show little
ordered outward proper motion of clumps as would have been expected for a jet.
A third epoch, taken only 50 days after the second, did show significant
changes in the radio morphology. These radio properties can all be understood
in the context of an equatorial wind driven by radiation pressure from the
central star and inner disc acting on the gas in the surface layers of the disc
as proposed by Drew et al. (1998). This equatorial wind system is briefly
compared with the one in S106IR, and contrasted with other massive young
stellar objects that drive ionized jets.Comment: 19 pages, 5 figures, accepted by ApJ, minor changes in light of
referees repor
Mean Field Theory of Josephson Junction Arrays with Charge Frustration
Using the path integral approach, we provide an explicit derivation of the
equation for the phase boundary for quantum Josephson junction arrays with
offset charges and non-diagonal capacitance matrix. For the model with nearest
neighbor capacitance matrix and uniform offset charge , we determine,
in the low critical temperature expansion, the most relevant contributions to
the equation for the phase boundary. We explicitly construct the charge
distributions on the lattice corresponding to the lowest energies. We find a
reentrant behavior even with a short ranged interaction. A merit of the path
integral approach is that it allows to provide an elegant derivation of the
Ginzburg-Landau free energy for a general model with charge frustration and
non-diagonal capacitance matrix. The partition function factorizes as a product
of a topological term, depending only on a set of integers, and a
non-topological one, which is explicitly evaluated.Comment: LaTex, 24 pages, 8 figure
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