1,294 research outputs found

    The Role of Final State Interactions in Quasielastic 56^{56}Fe(e,e)(e,e') Reactions at large q|\vec q|

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    A relativistic finite nucleus calculation using a Dirac optical potential is used to investigate the importance of final state interactions [FSI] at large momentum transfers in inclusive quasielastic electronuclear reactions. The optical potential is derived from first-order multiple scattering theory and then is used to calculate the FSI in a nonspectral Green's function doorway approach. At intermediate momentum transfers excellent predictions of the quasielastic 56^{56}Fe(e,e)(e,e') experimental data for the longitudinal response function are obtained. In comparisons with recent measurements at q=1.14|{\vec q|}=1.14~GeV/c the theoretical calculations of RLR_L give good agreement for the quasielastic peak shape and amplitude, but place the position of the peak at an energy transfer of about 4040~MeV higher than the data.Comment: 13 pages typeset using revtex 3.0 with 6 postscript figures in accompanying uuencoded file; submitted to Phys. Rev.

    Hawaiian Plumerias

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    Reprint June 1972The plumeria is an important ornamental tree in Hawaii as well as in Florida, the West Indies, Central America, India, China, Indonesia, Australia, islands of the Pacific basin, and some other tropical regions. This booklet covers all aspects of plumeria cultivation in Hawaii

    Towards the GEOSAT Follow-On Precise Orbit Determination Goals of High Accuracy and Near-Real-Time Processing

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    The US Navy's GEOSAT Follow-On spacecraft (GFO) primary mission objective is to map the oceans using a radar altimeter. Satellite laser ranging data, especially in combination with altimeter crossover data, offer the only means of determining high-quality precise orbits. Two tuned gravity models, PGS7727 and PGS7777b, were created at NASA GSFC for GFO that reduce the predicted radial orbit through degree 70 to 13.7 and 10.0 mm. A macromodel was developed to model the nonconservative forces and the SLR spacecraft measurement offset was adjusted to remove a mean bias. Using these improved models, satellite-ranging data, altimeter crossover data, and Doppler data are used to compute both daily medium precision orbits with a latency of less than 24 hours. Final precise orbits are also computed using these tracking data and exported with a latency of three to four weeks to NOAA for use on the GFO Geophysical Data Records (GDR s). The estimated orbit precision of the daily orbits is between 10 and 20 cm, whereas the precise orbits have a precision of 5 cm

    New Measures of the Trilemma Hypothesis: Implications for Asia

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    We develop a new set of indexes of exchange rate stability, monetary policy independence, and financial market openness as the metrics for the trilemma hypothesis. In our exploration, we take a different and more nuanced approach than the previous indexes developed by Aizenman, Chinn, and Ito (2008). We show that the new indexes add up to the value two, supporting the trilemma hypothesis. We locate our sample economies' policy mixes in the famous trilemma triangle - a useful and intuitive way to illustrate the state and evolution of policy mixes. We also examine if the persistent deviation of the sum of the three indexes from the value two indicates an unsustainable policy mix and therefore needs to be corrected by economic disruptions such as economic and financial crises. We obtain several findings. First, such a persistent deviation can occur particularly in emerging economies that later experience an inflation (or potentially a general or a currency) crisis, and dissipates in the postcrisis period. Second, there is no evidence for this type of association between deviations from the trilemma constraint and general, banking, or debt crises. Third, Thailand experienced such a deviation from the trilemma constraint in the period leading to the baht crisis of 1997, but not other East and Southeast Asian economies. This last result suggests that the main cause for the Thai baht crisis was an unsustainable policy mix in the precrisis period, while other affected economies experienced crises mainly due to contagion from Thailand

    Application of Multiple Scattering Theory to Lower Energy Elastic Nucleon-Nucleus Reactions

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    The optical model potentials for nucleon-nucleus elastic scattering at 6565~MeV are calculated for 12^{12}C, 16^{16}O, 28^{28}Si, 40^{40}Ca, 56^{56}Fe, 90^{90}Zr and 208^{208}Pb in first order multiple scattering theory, following the prescription of the spectator expansion, where the only inputs are the free NN potentials, the nuclear densities and the nuclear mean field as derived from microscopic nuclear structure calculations. These potentials are used to predict differential cross sections, analyzing powers and spin rotation functions for neutron and proton scattering at 65 MeV projectile energy and compared with available experimental data.Comment: 12 pages (Revtex 3.0), 7 fig

    A qualitative study of stakeholders' perspectives on the social network service environment

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    Over two billion people are using the Internet at present, assisted by the mediating activities of software agents which deal with the diversity and complexity of information. There are, however, ethical issues due to the monitoring-and-surveillance, data mining and autonomous nature of software agents. Considering the context, this study aims to comprehend stakeholders' perspectives on the social network service environment in order to identify the main considerations for the design of software agents in social network services in the near future. Twenty-one stakeholders, belonging to three key stakeholder groups, were recruited using a purposive sampling strategy for unstandardised semi-structured e-mail interviews. The interview data were analysed using a qualitative content analysis method. It was possible to identify three main considerations for the design of software agents in social network services, which were classified into the following categories: comprehensive understanding of users' perception of privacy, user type recognition algorithms for software agent development and existing software agents enhancement

    Sensitivities of the Proton-Nucleus Elastical Scattering Observables of 6He and 8He at Intermediate Energies

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    We investigate the use of proton-nucleus elastic scattering experiments using secondary beams of 6He and 8He to determine the physical structure of these nuclei. The sensitivity of these experiments to nuclear structure is examined by using four different nuclear structure models with different spatial features using a full-folding optical potential model. The results show that elastic scattering at intermediate energies (<100 MeV per nucleon) is not a good constraint to be used to determine features of structure. Therefore researchers should look elsewhere to put constraints on the ground state wave function of the 6He and 8He nuclei.Comment: To be published in Phys. Rev.

    Letting the Right Ones In: Whitelists, Jurisdictional Reputation, and the Racial Dynamics of Online Gambling Regulation.

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    Using a case study of a recent UK whitelist intended to regulate online gambling, I examine the affective politics of listing. I pay particular attention to the racial dynamics of black and white listing. By charting how the gambling whitelist worked and failed to work as a tool in the designation of jurisdictional reputation, I argue that the use and subsequent abandonment of the whitelist shows the centrality of racial dynamics to listing practices, particularly in relation to how the list was deployed in debates about the trustworthiness of the Kahnawá:ke territory and Antigua and Barbuda. In section 5 I examine what happened after the demise of the online gambling whitelist. Although non-listing techniques of governance look to be expanding, in the form of increased surveillance of individual gamblers, lists continue to play a key role in the UK government’s new model of gambling regulation. I suggest that this confirms the co-constitutive and mutually reinforcing nature of black and white lists as techniques of governance, and the value of exploring them and their racialized implications together
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