2,985 research outputs found

    Next-Generation Media: The Global Shift

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    For over a decade the Aspen Institute Communications and Society Program has convened its CEO-level Forum on Communications and Society (FOCAS) to address specific issues relating to the impact of communications media on societal institutions and values. These small, invitation-only roundtables have addressed educational, democratic, and international issues with the aim of making recommendations to policy-makers, businesses and other institutions to improve our society through policies and actions in the information and communications sectors.In the summer of 2006 the forum took a different turn. It is clear there is a revolution affecting every media business, every consumer or user of media, and every institution affected by media. In a word, everyone. FOCAS sought to define the paradigm changes underway in the media, and to identify some of the significant repercussions of those changes on society."Next Generation Media" was a three-day meeting among leaders from new media (e.g., Google, craigslist, and Second Life) and mainstream media (e.g., The New York Times and Time), from business, government, academia and the non-profit sector, all seeking a broad picture of where the digital revolution is taking us.This report of the meeting, concisely and deftly written by Richard Adler, a longtime consultant in the field, weaves insights and anecdotes from the roundtable into a coherent document supplemented with his own research and data to form an accessible, coherent treatment of this very topical subject.The specific goals of the 2006 forum were to examine the profound changes ahead for the media industries, advertisers, consumers and users in the new attention economy; to understand how the development and delivery of content are creating new business models for commercial and non-commercial media; and to assess the impact of these developments on global relations, citizenship and leadership.The report thus examines the growth of the Internet and its effect on a rapidly changing topic: the impact of new media on politics, business, society, culture, and governments the world over. The report also sheds light on how traditional media will need to adapt to face the competition of the next generation media.Beginning, as the Forum did, with data from Jeff Cole's Center for the Digital Future at the University of Southern California, Adler documents the increasing popularity of the Internet for information, entertainment and communication. Users are increasingly generating and contributing content to the web and connecting to social networks. They are posting comments, uploading pictures, sharing videos, blogging and vlogging, chatting through instant messages or voice over Internet (VoIP), or emailing friends, business colleagues, neighbors and even strangers. As Cole observes, "Traditional media informed people but didn't empower them." New media do.The report describes three of the Internet's most successful ventures -- Wikipedia, Second Life, and craigslist. Wikipedia is a prime example of how an Internet platform allows its users to generate content and consume it. As a result of "wiki" software technology anyone can contribute or edit existing information free of cost. Second Life, a virtual world, sells virtual real estate where subscribers, in avatar form, can conduct conversations, go to lectures, even create a business. Craigslist, a predominantly free online classified site with listings in every major city in the United States, has become so popular that it is posing a significant threat to newspapers as it competes with their classified ad revenues.As a result of these and other new media phenomena, not the least being Google and Yahoo, print publications are wrestling with new business models that could entail fundamentally restructuring the way they operate. For instance, reporters are now expected to report a story on multiple media platforms and discuss them online with readers. Newspaper publisher Gannett is exploring the incorporation of usergenerated news or "citizen-journalism" into its news pages.In an era of abundant choices marketers have an even greater challenge to figure out how best to appeal to consumers. The report explores how marketers, e.g., of Hollywood movies or pomegranate juice, are moving from traditional or mainstream media to viral and other marketing techniques.For much of the world, the mobile phone rather than the computer is the most important communications device. Users depend on their phones to send and receive messages, pictures, and download information rather than just talk. In developing countries mobile phones are having an exceptional impact, penetrating regions which are not being serviced by land lines. Thus we are seeing new uses daily for this increased connectivity, from reporting election results in emerging democracies to opposing authoritarian governments in order to bring about new democracies.Meanwhile, the report discusses the need for the United States to develop a new form of public diplomacy rather than the traditional top-down approach to communicating to foreign citizens. This topic has been a recurring theme at FOCAS conferences the past few years, this year calling for more citizen diplomacy -- that is, more person-toperson contact across borders through uses of the new media. Indeed, Peter Hirshberg suggested that American leaders should listen more to the outside world to effectively manage what he called "Brand America."Finally, after acknowledging the detrimental effects that new technologies can bring about, the report discusses what role those technologies could play in expanding freedom and opportunity for the next generation. As a conclusion, FOCAS co-chair Marc Nathanson proposed adding a ninth goal to the United Nations Millennium Goals, namely, "to provide access to appropriate new technologies.

    Shell structure in neutron-rich Ca and Ni nuclei under semi-realistic mean fields

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    Shell structure in the neutron-rich Ca and Ni nuclei is investigated by the spherical Hartree-Fock calculations with the semi-realistic NNNN interactions. Specific ingredients of the effective interaction, particularly the tensor force, often play a key role in the ZZ dependence of the neutron shell structure. Such examples are found in N=32 and N=40; N=32 becomes magic or submagic in 52^{52}Ca while its magicity is broken in 60^{60}Ni, and N=40 is submagic (though not magic) in 68^{68}Ni but not in 60^{60}Ca. Comments are given on the doubly magic nature of 78^{78}Ni. We point out that the loose binding can lead to a submagic number N=58 in 86^{86}Ni, assisted by the weak pair coupling.Comment: 14 pages including 5 figures, to appear in Physical Review C (Rapid Communication

    Effect of the tensor force in the exchange channel on the spin-orbit splitting in 23F in the Hartree-Fock framework

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    We study the spin-orbit splitting (lsls-splitting) for the proton d-orbits in 23F in the Hartree-Fock framework with the tensor force in the exchange channel. 23F has one more proton around the neutron-rich nucleus 22O. A recent experiment indicates that the ls-splitting for the proton d-orbits in 23F is reduced from that in 17F. Our calculation shows that the ls-splitting in 23F becomes smaller by about a few MeV due to the tensor force. This effect comes from the interaction between the valence proton and the occupied neutrons in the 0d5/2 orbit through the tensor force and makes the ls-splitting in 23F close to the experimental data

    Underlying symmetries of realistic interactions and the nuclear many-body problem

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    The present study brings forward important information, within the framework of spectral distribution theory, about the types of forces that dominate three realistic interactions, CD-Bonn, CDBonn+ 3terms and GXPF1, in nuclei and their ability to account for many-particle effects such as the formation of correlated nucleon pairs and enhanced quadrupole collective modes. Like-particle and proton-neutron isovector pairing correlations are described microscopically by a model interaction with Sp(4) dynamical symmetry, which is extended to include an additional quadrupole-quadrupole interaction. The analysis of the results for the 1f7/2 level shows that both CD-Bonn+3terms and GXPF1 exhibit a well-developed pairing character compared to CD-Bonn, while the latter appears to build up more (less) rotational isovector T = 1 (isoscalar T = 0) collective features. Furthermore, the three realistic interactions are in general found to correlate strongly with the pairing+quadrupole model interaction, especially for the highest possible isospin group of states where the model interaction can be used to provide a reasonable description of the corresponding energy spectra.Comment: 12 pages, 4 figure

    Isospin symmetry breaking in an algebraic pairing Sp(4) model

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    An exactly solvable sp(4) algebraic approach extends beyond the traditional isospin conserving nuclear interaction to bring forward effects of isospin symmetry breaking and isospin mixing resulting from a two-body nuclear interaction that includes proton-neutron (pn) and like-particle isovector pairing correlations plus significant isoscalar pn interactions. The model yields an estimate for the extent to which isobaric analog 0+ states in light and medium mass nuclei may mix with one another and reveals possible, but still extremely weak, non-analog beta-decay transitions.Comment: 8 pages, 2 figure

    Dynamical symmetry of isobaric analog 0+ states in medium mass nuclei

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    An algebraic sp(4) shell model is introduced to achieve a deeper understanding and interpretation of the properties of pairing-governed 0+ states in medium mass atomic nuclei. The theory, which embodies the simplicity of a dynamical symmetry approach to nuclear structure, is shown to reproduce the excitation spectra and fine structure effects driven by proton-neutron interactions and isovector pairing correlations across a broad range of nuclei.Comment: 7 pages, 5 figure

    Dynamical approach to heavy-ion induced fission using actinide target nuclei at energies around the Coulomb barrier

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    In order to describe heavy-ion fusion reactions around the Coulomb barrier with an actinide target nucleus, we propose a model which combines the coupled-channels approach and a fluctuation-dissipation model for dynamical calculations. This model takes into account couplings to the collective states of the interacting nuclei in the penetration of the Coulomb barrier and the subsequent dynamical evolution of a nuclear shape from the contact configuration. In the fluctuation-dissipation model with a Langevin equation, the effect of nuclear orientation at the initial impact on the prolately deformed target nucleus is considered. Fusion-fission, quasi-fission and deep quasi-fission are separated as different Langevin trajectories on the potential energy surface. Using this model, we analyze the experimental data for the mass distribution of fission fragments (MDFF) in the reactions of 34,36^{34,36}S+238^{238}U and 30^{30}Si+238^{238}U at several incident energies around the Coulomb barrier. We find that the time scale in the quasi-fission as well as the deformation of fission fragments at the scission point are different between the 30^{30}Si+238^{238}U and 36^{36}S+238^{238}U systems, causing different mass asymmetries of the quasi-fission.Comment: 11 figure

    Coupling transport and biodegradation of VOCs in surface and subsurface soils.

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    Volatile organic chemicals present at Superfund sites preferentially partition into the soil gas and may be available for microbial degradation. A simple mass transfer model for biodegradation for volatile substrates has been developed for the aerobic decomposition of aromatic and aliphatic hydrocarbons. The mass transfer analysis calculates diffusive fluxes from soil gas through water and membrane films and into the cell. This model predicts an extreme sensitivity of potential biodegradation rates to the air-water partition coefficients of the compounds. Aromatic hydrocarbons are removed rapidly while the aliphatic hydrocarbons are much slower by orders of magnitude. Furthermore, oxygen transfer is likely to limit aromatic hydrocarbon degradation rates. The model presents results that cast doubt on the practicality of using methane or propane for the co-metabolic destruction of trichloroethylene in a gas phase bioreactor. Toluene as a primary substrate has better mass transfer characteristics to achieve more efficient trichloroethylene degradation. Hence, in sites where these contaminants coexist, bioremediation could be improved

    Ground state magnetic dipole moment of 35K

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    The ground state magnetic moment of 35K has been measured using the technique of nuclear magnetic resonance on beta-emitting nuclei. The short-lived 35K nuclei were produced following the reaction of a 36Ar primary beam of energy 150 MeV/nucleon incident on a Be target. The spin polarization of the 35K nuclei produced at 2 degrees relative to the normal primary beam axis was confirmed. Together with the mirror nucleus 35S, the measurement represents the heaviest T = 3/2 mirror pair for which the spin expectation value has been obtained. A linear behavior of gp vs. gn has been demonstrated for the T = 3/2 known mirror moments and the slope and intercept are consistent with the previous analysis of T = 1/2 mirror pairs.Comment: 14 pages, 5 figure
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