5,244 research outputs found
Microgravity Combustion Diagnostics Workshop
Through the Microgravity Science and Applications Division (MSAD) of the Office of Space Science and Applications (OSSA) at NASA Headquarters, a program entitled, Advanced Technology Development (ATD) was promulgated with the objective of providing advanced technologies that will enable the development of future microgravity science and applications experimental flight hardware. Among the ATD projects one, Microgravity Combustion Diagnostics (MCD), has the objective of developing advanced diagnostic techniques and technologies to provide nonperturbing measurements of combustion characteristics and parameters that will enhance the scientific integrity and quality of microgravity combustion experiments. As part of the approach to this project, a workshop was held on July 28 and 29, 1987, at the NASA Lewis Research Center. A small group of laser combustion diagnosticians met with a group of microgravity combustion experimenters to discuss the science requirements, the state-of-the-art of laser diagnostic technology, and plan the direction for near-, intermediate-, and long-term programs. This publication describes the proceedings of that workshop
A nexus perspective on competing land demands: Wider lessons from a UK policy case study
As nations develop policies for low-carbon transitions, conflicts with existing policies and planning tools are leading to competing demands for land and other resources. This raises fundamental questions over how multiple demands can best be managed. Taking the UK as an empirical example, this paper critiques current policies and practices to explore the interdependencies at the water-energy-food nexus. It considers how current land uses and related policies affect the UK’s resilience to climate change, setting out an agenda for research and practice relevant to stakeholders in land-use management, policy and modelling. Despite recent progress in recognising such nexus challenges, most UK land-related policies and associated science continue to be compartmentalised by both scale and sector and seldom acknowledge nexus interconnections. On a temporal level, the absence of an over-arching strategy leaves inter-generational trade-offs poorly considered. Given the system lock-in and the lengthy policy-making process, it is essential to develop alternative ways of providing dynamic, flexible, practical and scientifically robust decision support for policy-makers. A range of ecosystem services need to be valued and integrated into a resilient land-use strategy, including the introduction of non-monetary, physical-unit constraints on the use of particular services
The size, concentration, and growth of biodiversity-conservation nonprofits
Nonprofit organizations play a critical role in efforts to conserve biodiversity. Their success in this regard will be determined in part by how effectively individual nonprofits and the sector as a whole are structured. One of the most fundamental questions about an organization’s structure is how large it should be, with the logical counterpart being how concentrated the whole sector should be. We review empirical patterns in the size, concentration, and growth of over 1700 biodiversity-conservation nonprofits registered for tax purposes in the United States within the context of relevant economic theory. Conservation-nonprofit sizes vary by six to seven orders of magnitude and are positively skewed. Larger nonprofits access more revenue streams and hold more of their assets in land and buildings than smaller or midsized nonprofits do. The size of conservation nonprofits varies with the ecological focus of the organization, but the growth rates of nonprofits do not
External Shear in Quadruply Imaged Lens Systems
We use publicly available N-body simulations and semi-analytic models of
galaxy formation to estimate the levels of external shear due to structure near
the lens in gravitational lens systems. We also describe two selection effects,
specific to four-image systems, that enhance the probability of observing
systems to have higher external shear. Ignoring additional contributions from
"cosmic shear" and assuming that lens galaxies are not significantly flattened,
we find that the mean shear at the position of a quadruple lens galaxy is 0.11,
the rms shear is roughly 0.15, and there is roughly a 45% likelihood of
external shear greater than 0.1. This is much larger than previous estimates
and in good agreement with typical measured external shear. The higher shear
primarily stems from the tendency of early-type galaxies, which are the
majority of lenses, to reside in overdense regions.Comment: 5 pages, 2 figures, ApJ in press, minor revision
Staying true with the help of others: doxastic self-control through interpersonal commitment
I explore the possibility and rationality of interpersonal mechanisms of doxastic self-control, that is, ways in which individuals can make use of other people in order to get themselves to stick to their beliefs. I look, in particular, at two ways in which people can make interpersonal epistemic commitments, and thereby willingly undertake accountability to others, in order to get themselves to maintain their beliefs in the face of anticipated “epistemic temptations”. The first way is through the avowal of belief, and the second is through the establishment of collective belief. I argue that both of these forms of interpersonal epistemic commitment can function as effective tools for doxastic self-control, and, moreover, that the control they facilitate should not be dismissed as irrational from an epistemic perspective
Recommended from our members
The design of UV absorbing systems for horticultural applications
The synthesis and fluorescence behavior of a series of bis(trisilylalkyl)anthracene molecules is described. The photodegradation of these molecules under UV light has been monitored and compared to a commercially available fluorescent optical brightener. There is a relationship between the structure and the rate of photo decay. The materials with more bulky substituents exhibit the greater stability towards UV. For bis(triphenylsilyl)anthracene the photostability appears to be comparable with a commercially available optical brightener, but the molecule may be susceptible to thermal decay
First-principles calculations of magnetization relaxation in pure Fe, Co, and Ni with frozen thermal lattice disorder
The effect of the electron-phonon interaction on magnetization relaxation is
studied within the framework of first-principles scattering theory for Fe, Co,
and Ni by displacing atoms in the scattering region randomly with a thermal
distribution. This "frozen thermal lattice disorder" approach reproduces the
non-monotonic damping behaviour observed in ferromagnetic resonance
measurements and yields reasonable quantitative agreement between calculated
and experimental values. It can be readily applied to alloys and easily
extended by determining the atomic displacements from ab initio phonon spectra
Assessing the Impact of Premier Information Systems Research over Time
In this study we examine the influence of premier information systems research over time to assess the maturity of the Information Systems (IS) field and its impact on subsequent IS and non-IS research. 19,357 citations from the Social Science Citation Index (SSCI) (1982-2004) are attributed to 879 articles published in MIS Quarterly (MISQ), Information Systems Research (ISR), and the IS articles from Management Science (MS) between 1982 and 2004, and this number continues to increase over time. The results suggest that research in premier IS journals has an influence on other disciplines as 7,137 citations come from outside the IS discipline and this number continues to increase over time. Of particular note is the consistent increase over time in citations of premier IS research articles from the management, engineering and physical sciences, organizational behavior, and computer science disciplines. Given recent debates regarding the IT artifact, we also directly test the impact of articles that address the IT artifact and those that do not. We find that articles that directly address the IT artifact are cited significantly more often than those that do not, consistent with arguments made by Benbasat et al. [2003]
- …