1,255 research outputs found

    Transverse Target Moments of SIDIS Vector Meson Production at HERMES

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    The on-going analysis of the transverse target ( A UT ) moments of the non-collinear cross section for SIDIS dihadron production at Hermes is discussed. These moments access the transversity ( h 1 ), pretzelocity ( h _ 1T ), and Sivers ( f _ 1T ) distribution functions convoluted with the unpolarized ( D 1 ) and Collins ( H 1 ) dihadron fragmentation functions. This measurement allows greater insight into the flavor decomposition and factorization of these functions. Additionally, the results will test the Lund/Artru fragmentation model, which predicts a sign change in the Collins function between pseudo-scalar mesons and certain partial waves of vector mesons. In preparation for this analysis, a new Monte Carlo generator has been written, and non-collinear fragmentation functions have been computed in a spectator model. Additionally, an alternate partial wave expansion is presented, providing a complementary interpretation of the fragmentation functions and allowing computation of the next-to-leading twist cross section.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90826/1/1742-6596_295_1_012044.pd

    Parallel fabrication and single-electron charging of devices based on ordered, two-dimensional phases of organically functionalized metal nanocrystals

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    A parallel technique for fabricating single-electron, solid-state capacitance devices from ordered, two-dimensional closest-packed phases of organically functionalized metal nanocrystals is presented. The nanocrystal phases were prepared as Langmuir monolayers and subsequently transferred onto Al-electrode patterned glass substrates for device construction. Alternating current impedance measurements were carried out to probe the single-electron charging characteristics of the devices under both ambient and 77 K conditions. Evidence of a Coulomb blockade and step structure reminiscent of a Coulomb staircase is presented

    Development of tip-splitting and side-branching patterns in elastic fingering

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    Elastic fingering supplements the already interesting features of the traditional viscous fingering phenomena in Hele-Shaw cells with the consideration that the two-fluid separating boundary behaves like an elastic membrane. Sophisticated numerical simulations have shown that under maximum viscosity contrast the resulting patterned shapes can exhibit either finger tip-splitting or side-branching events. In this work, we employ a perturbative mode-coupling scheme to get important insights into the onset of these pattern formation processes. This is done at lowest nonlinear order and by considering the interplay of just three specific Fourier modes: a fundamental mode n and its harmonics 2n and 3n. Our approach further allows the construction of a morphology diagram for the system in a wide range of the parameter space without requiring expensive numerical simulations. The emerging interfacial patterns are conveniently described in terms of only two dimensionless controlling quantities: the rigidity fraction C and a parameter Γ that measures the relative strength between elastic and viscous effects. Visualization of the rigidity field for the various pattern-forming structures supports the idea of an elastic weakening mechanism that facilitates finger growth in regions of reduced interfacial bending rigidity

    Proces hadronizacije u duboko-neelastičnom raspršenju u eksperimentu HERMES

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    The influence of the nuclear medium on lepto-production of hadrons was studied in the HERMES experiment at DESY in semi-inclusive deep-inelastic scattering of 27.6 GeV and 12 GeV positrons off deuterium, and off light and heavy targets. The differential multiplicity for nuclei relative to that of deuterium has been measured for the first time for various identified hadrons (π +, π −, π 0 , K+, K−, p and ¯p) as a function of the virtual photon energy ν, the fraction z of this energy transferred to the hadron, and the hadron transverse momentum squared p 2 t .Proučavamo utjecaj nuklearne tvari na leptonsku tvorbu hadrona u mjerenju HERMES u DESYu poluinkluzivnim duboko-neelastičnim raspršenjem pozitrona energije 27.6 GeV i 12 GeV u deuteriju, te lakim i teškim metama. Načinili smo prva mjerenja omjera diferencijalne višestrukosti za jezgre u odnosu prema deuteriju za više utvrđenih hadrona (π +, π −, π 0 , K+, K−, p and ¯p) u ovisnosti o virtualnoj energiji fotona ν, dijela te energije z predane hadronu i kvadrata poprečnog impulsa pt2

    Review of community-based ICM: best practices and lessons learned in the Bay of Bengal, South Asia

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    Conclusions and recommendations of the report were based upon eighteen case studies of community-based Integrated Coastal Management (ICM) in Bangladesh, India, Maldives and Sri Lanka. These include empowerment of coastal communities; failure of imposed fishery co-operatives; and the application of territorial use rights in fisheries(TURF)

    Contact Relationships of the Late Paleozoic Narragansett Pier Granite and Country Rock

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    Guidebook to geologic field studies in Rhode Island and adjacent areas: The 73rd annual meeting of the New England Intercollegiate Geological Conference, October 16-18, 1981: Trip B-

    Multidecadal Wind Variability Drives Temperature Shifts on the Agulhas Bank

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    Key Points: • A regional ocean model is used to examine multidecadal shelf temperature changes on the Agulhas Bank • There are distinct shelf temperature regime changes in 1966 and 1996 • These regime shifts are caused by changes in coastal upwelling linked to large-scale wind variability The Agulhas Bank is an important area for the spawning of small pelagic fish and other species. Here, within a NEMO ocean model, we investigate changes in temperature over the Bank on multidecadal time scales. In agreement with previous observational studies, a shift to colder temperatures is found in 1997. The model also simulates an earlier shift from colder to warmer temperatures in 1966. These shifts are coastally confined and shown, using a climatologically forced model run as a control, to be driven by a north‐south migration in the large‐scale wind belts, rather than by changes in downward heat fluxes or changes in the Agulhas Current itself. The zonal wind changes on the Agulhas Bank show a significant relationship with the Southern Annular Mode, showing some promise for future predictability of cold and warm regimes on the Agulhas Bank. Thus, while the Agulhas Current has been shown in previous work to have a large impact on intra‐annual and interannual temperature variability, this work shows that multidecadal variability in temperature on the shelf is likely to be wind forced

    Computing and Social Welfare: Minimizing the Societal Harm From Digital Transfor-mation While Preserving the Benefits of Innovation

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    Social Welfare Computing is an emerging discipline that seeks to direct technology to cause minimum social disruption, and in particular seeks to minimize the harm caused directly by technology. This is markedly different from the better understood strategic use of technology to create value or to address existing social needs. Innovative technologies that are widely adopted created significant value for their users; otherwise they would not be widely adopted. Often the companies that create them obtain new sources of wealth and power, which inevitably lead to new abuses of power and new forms of societal disruption. Societal disruption in turn requires social adaptation, including new regulations to influence the behavior of firms and to define and to protect the rights of an individual in the changed society. Social Welfare Computing seeks to guide social adaptation, combining insights from disciplines as varied as anthropology, business strategy, economics, strategic planning, and law
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