2,593 research outputs found
Low-speed wind-tunnel investigation of wing fins as trailing-vortex-alleviation devices on a transport airplane model
The trailing-vortex-alleviation effectiveness of both a one- and a two-fin configuration (semicircular with a radius of 0.043 semispan) on a jumbo-jet transport airplane model in its landing configuration was investigated in the Langley V/STOL tunnel, by the trailing-wing sensor technique. The fins were located on the upper surface of the transport model wing along the 30-percent-chord line. The fin configurations were effective in reducing the vortex-induced rolling moment, by amounts varying from 28 to 60 percent, on the trailing wing model located at a distance of 7.8 transport model wing spans downstream of the transport model. The flow over the fins and over the transport airplane model wing downstream of the fins was observed to be separated and turbulent. All fin configurations caused a reduction in maximum lift coefficient, a positive increment in drag coefficient, and an increment in nose-up pitching-moment coefficient on the transport airplane model
Design and development of a 5 kV isolated solid state switch
A unique microcircuit intended for use as a shorting switch for large extraterrestrial solar cell arrays is described. The packaging design for the 5 kV isolated hybrid switch is different from most hybrid microcircuits in that it utilizes a compartmentalized plastic case (a portion of which is encapsulated), is not hermetic, and is designed for high voltage operation
Science lives: School choices and ânatural tendenciesâ
An analysis of 12 semi-structured interviews with university-based scientists and non-scientists illustrates their life journeys towards, or away from, science and the strengths and impact of life occurrences leading them to choose science or non-science professions. We have adopted narrative approaches and used Mezirow's transformative learning theory framework. The areas of discussion from the result have stressed on three main categories that include âsmooth transitionâ, âincremental wavering transition' and âtransformative transitionâ. The article concludes by discussing the key influences that shaped initial attitudes and direction in these people through natural inclination, environmental inspirations and perceptions of science
Intermediate phase, network demixing, boson and floppy modes, and compositional trends in glass transition temperatures of binary AsxS1-x system
The structure of binary As_xS_{1-x} glasses is elucidated using
modulated-DSC, Raman scattering, IR reflectance and molar volume experiments
over a wide range (8%<x<41%) of compositions. We observe a reversibility window
in the calorimetric experiments, which permits fixing the three elastic phases;
flexible at x<22.5%, intermediate phase (IP) in the 22.5%<x<29.5% range, and
stressed-rigid at x>29.5%. Raman scattering supported by first principles
cluster calculations reveal existence of both pyramidal (PYR, As(S1/2)3) and
quasi-tetrahedral(QT, S=As(S1/2)3) local structures. The QT unit concentrations
show a global maximum in the IP, while the concentration of PYR units becomes
comparable to those of QT units in the phase, suggesting that both these local
structures contribute to the width of the IP. The IP centroid in the sulfides
is significantly shifted to lower As content x than in corresponding selenides,
a feature identified with excess chalcogen partially segregating from the
backbone in the sulfides, but forming part of the backbone in selenides. These
ideas are corroborated by the proportionately larger free volumes of sulfides
than selenides, and the absence of chemical bond strength scaling of Tgs
between As-sulfides and As-selenides. Low-frequency Raman modes increase in
scattering strength linearly as As content x of glasses decreases from x = 20%
to 8%, with a slope that is close to the floppy mode fraction in flexible
glasses predicted by rigidity theory. These results show that floppy modes
contribute to the excess vibrations observed at low frequency. In the
intermediate and stressed rigid elastic phases low-frequency Raman modes
persist and are identified as boson modes. Some consequences of the present
findings on the optoelectronic properties of these glasses is commented upon.Comment: Accepted for PR
Development of Readout Interconnections for the Si-W Calorimeter of SiD
The SiD collaboration is developing a Si-W sampling electromagnetic
calorimeter, with anticipated application for the International Linear
Collider. Assembling the modules for such a detector will involve special
bonding technologies for the interconnections, especially for attaching a
silicon detector wafer to a flex cable readout bus. We review the interconnect
technologies involved, including oxidation removal processes, pad surface
preparation, solder ball selection and placement, and bond quality assurance.
Our results show that solder ball bonding is a promising technique for the Si-W
ECAL, and unresolved issues are being addressed.Comment: 8 pages + title, 6 figure
Split Tickets? On the Strategic Allocation of Presidential Versus Vice Presidential Visits in 2016
This article analyzes the strategic allocation of presidential campaign visits in 2016. In particular, we test whether each campaign disproportionately targeted its presidential versus vice presidential candidatesâ visits toward voters with whom they shared a salient demographic or political characteristic. Our purpose in doing so is to discern whetherâand, if so, among which groupsâthe campaigns perceived the candidates as having a strategic advantage in appealing to affiliated voters. To this end, we analyze an original database of 2016 campaign visits that includes local population characteristics for each host site. Our results indicate that each ticketâs visits were highly coordinated across states, but frequently divergent within states. At the substate level, we find several systematic differences in the populations visited by presidential versus vice presidential candidatesâin some cases aligning with a candidateâs personal characteristics. We discuss these findingsâ implications with respect to campaign strategy and vice presidential selection
Co-patentsâ commercialization: evidence from China
Co-patents are outcomes of R&D collaboration, which has been
proven with higher-quality. Does this mean that high-quality patents
should also extend their advantage to the technology market?
Based on the transaction cost theory, we use the China
National Intellectual Property Administration (CNIPA) database
and logit model to explore the effect of co-ownership on firmsâ
patent commercialization and the factors of co-patents that affect
their commercialization. Our findings illustrate that co-ownership
has a negative impact on patent commercialization. In addition,
the co-ownerâs nature, country, and co-patentâs industry influence
the commercialization of co-patents. Firstly, a company and a university
or research institutionâs co-owned co-patents are less likely
to be commercialization than a company and a company coowned
co-patents. Secondly, multi-countries co-owned co-patents
are less likely to be commercialization than a single-country coowned
co-patents. Thirdly, co-patents in high technology (hightech)
industries are less likely to be commercialization than copatents
in non-high-tech industries. This paper supports policymakers
in implementing policies to promote the co-patentsâ commercialization.
Meanwhile, our paper suggests that to pursue the
economic value of the R&D collaborative intellectual property
fruits, R&D collaborative intellectual property fruits are not be
encouraged to be applied as the co-patents.European Union (EU)
TIN2016-75850-
A tri-dimensional approach for auditing brand loyalty
Over the past twenty years brand loyalty has been an important topic for both marketing practitioners and academics. While practitioners have produced proprietary brand loyalty audit models, there has been little academic research to make transparent the methodology that underpins these audits and to enable practitioners to understand, develop and conduct their own audits. In this paper, we propose a framework for a brand loyalty audit that uses a tri-dimensional approach to brand loyalty, which includes behavioural loyalty and the two components of attitudinal loyalty: emotional and cognitive loyalty. In allowing for different levels and intensity of brand loyalty, this tri-dimensional approach is important from a managerial perspective. It means that loyalty strategies that arise from a brand audit can be made more effective by targeting the market segments that demonstrate the most appropriate combination of brand loyalty components. We propose a matrix with three dimensions (emotional, cognitive and behavioural loyalty) and two levels (high and low loyalty) to facilitate a brand loyalty audit. To demonstrate this matrix, we use the example of financial services, in particular a rewards-based credit card
An analysis of integrative outcomes in the Dayton peace negotiations
The nature of the negotiated outcomes of the eight issues of the Dayton Peace Agreement was studied in terms of their integrative and distributive aspects. in cases where integrative elements were Sound, further analysis was conducted by concentrating on Pruitt's five types of integrative solutions: expanding the pie, cost cutting, non-specific compensation, logrolling, and bridging. The results showed that real world international negotiations can arrive at integrative agreements even when they involve redistribution of resources tin this case the redistribution of former Yugoslavia). Another conclusion was that an agreement can consist of several distributive outcomes and several integrative outcomes produced by different kinds of mechanisms. Similarly, in single issues more than one mechanism can be used simultaneously. Some distributive bargaining was needed in order to determine how much compensation was required. Finally, each integrative formula had some distributive aspects as well
Further challenges to the âauthenticâ/âhubristicâ model of pride: Conceptual clarifications and new evidence.
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