Basic research in wake vortex alleviation using a variable twist wing

The variable twist wing concept was used to investigate the relative effects of lift and turbulence distribution on the rolled up vortex wake. Several methods of reducing the vortex strength behind an aircraft were identified. These involve the redistribution of lift spanwise on the wing and drag distribution along the wing. Initial attempts to use the variable twist wing velocity data to validate the WAKE computer code have shown a strong correlation, although the vorticity levels were not exactly matched

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 ‘natural tendencies’

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 ‘smooth transition’, ‘incremental wavering transition' and ‘transformative transition’. 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

Human Performance Contributions to Safety in Commercial Aviation

In the commercial aviation domain, large volumes of data are collected and analyzed on the failures and errors that result in infrequent incidents and accidents, but in the absence of data on behaviors that contribute to routine successful outcomes, safety management and system design decisions are based on a small sample of non- representative safety data. Analysis of aviation accident data suggests that human error is implicated in up to 80% of accidents, which has been used to justify future visions for aviation in which the roles of human operators are greatly diminished or eliminated in the interest of creating a safer aviation system. However, failure to fully consider the human contributions to successful system performance in civil aviation represents a significant and largely unrecognized risk when making policy decisions about human roles and responsibilities. Opportunities exist to leverage the vast amount of data that has already been collected, or could be easily obtained, to increase our understanding of human contributions to things going right in commercial aviation. The principal focus of this assessment was to identify current gaps and explore methods for identifying human success data generated by the aviation system, from personnel and within the supporting infrastructure

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 candidates’ visits toward voters with whom they shared a salient demographic or political characteristic. Our purpose in doing so is to discern whether—and, if so, among which groups—the 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 ticket’s 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 candidates—in some cases aligning with a candidate’s personal characteristics. We discuss these findings’ implications with respect to campaign strategy and vice presidential selection

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

Co-patents’ 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 firms’ 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-owner’s nature, country, and co-patent’s industry influence the commercialization of co-patents. Firstly, a company and a university or research institution’s 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-patents’ 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-

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