1,138 research outputs found
Photoproduction of the Hypertriton
In the framework of the impulse approximation we study the photoproduction of
the hypertriton H by using realistic He wave functions
obtained as solutions of Faddeev equations with the Reid soft-core potential
for different H wave functions. We obtain relatively small cross
sections of the order of 1 nb. We also find that the influence of Fermi motion
is important, while the effect of different off-shell assumptions on the cross
section is not too significant.Comment: 6 pages in Latex. Talk given at the 15th International Conference on
Few-Body Problems in Physics, Groningen, Netherlands, 22-26 July 1997. To be
published in Nucl. Phys.
Least squares finite element simulation of transonic flows
Finite difference approximation of transonic flow problems is a well-developed and largely successful approach. Nevertheless, there is still a real need to develop finite element methods for applications arising from fluid-structure interactions and problems with complicated boundaries. In this paper a least squares based finite element scheme is introduced. It is shown that, if suitably formulated, such an approach can lead to physically meaningful results. Bottlenecks that arise from such schemes are also discussed
The Capitalist Mode of Power: Second Speaker Series
capital accumulation capitalist mode of power economic growth General Electric hierarchy Hollywood public debtExisting theories of capitalism, mainstream as well as heterodox, view capitalism as a mode of production and consumption. This speaker series interrogates capitalism as a mode of power. The five presentations deal with the past, present and future of the CasP project (Bichler & Nitzan), the historical connection between economic growth and the formation of social hierarchy (Fix), the role of blockbuster cinema in reducing Hollywood's risk (McMahon), the external-internal power dynamics of the U.S. public debt (Hager), and General Electric’s staying power and what can be learned from it for the study of capital accumulation (Cochrane).
The speaker series is organized by the Forum on Capital as Power and sponsored by the York Department of Political Science and Graduate Program in SPT.
LOCATION: Verney Room, 674 South Ross, Keele Campus (open to all, with refreshments)
DATES: October 20, 27; November 3, 10, 17, 2015
TIME: 3:00-5:00 P
Incoherent Photoproduction of -mesons from the Deuteron near Threshold
Incoherent photoproduction of the -meson on the deuteron is studied for
photon energies from threshold to 800 MeV. The dominant contribution, the
N-N amplitude, is described within an isobar model. The final
state interaction derived from the CD-Bonn potential is included and found to
be important for the description of the production cross section close to
threshold. Possible effects from the final state interaction are
discussed.Comment: 11 pages, revtex, including 6 figure
The -3N problem with separable interactions
The -3N-interaction is studied within the four-body Faddeev-Yakubovsky
theory adopting purely separable forms for the two- and three-body
subamplitudes, limiting the basic two-body interactions to s-waves only. The
corresponding separable approximation for the integral kernels is obtained by
using the Hilbert-Schmidt procedure. Results are presented for the -H
scattering amplitude and for the total elastic cross section for energies below
the triton break-up threshold.Comment: revised version accepted for Phys. Rev. C, 16 pages revtex including
6 eps-figures, formal part shortene
The Rational Faculty of Desire
This essay is about the relationship between the notions of practical reason, the will, and choice in Kant’s practical philosophy. Although Kant explicitly identifies practical reason and the will, many interpreters argue that he cannot really mean it on the grounds that unless they are distinct, irrational and, especially, immoral action is impossible. Other readers affirm his identification but distinguish the will from choice on the same basis. We argue that proper attention to Kant’s conception of practical reason as a capacity reveals that these distinctions are neither textually grounded nor philosophically necessary. His moral psychology concerns a single capacity, practical reason, which is the will, and whose actualities in this or that individual fall under the title of choice. Practical reason is the will and choice because it is the rational faculty of desire: a rational being’s capacity to be, by means of her representations, the cause of the actuality of their objects. This, we argue, is entailed by his conception of rational action: action not just in accordance with, but in and through the representation of, principles. The possibility of irrational action is explained not by a distinction between capacities but by the finitude, and thereby the fallibility, of human reason
Solar Flare Intermittency and the Earth's Temperature Anomalies
We argue that earth's short-term temperature anomalies and the solar flare
intermittency are linked. The analysis is based upon the study of the scaling
of both the spreading and the entropy of the diffusion generated by the
fluctuations of the temperature time series. The joint use of these two methods
evidences the presence of a L\'{e}vy component in the temporal persistence of
the temperature data sets that corresponds to the one that would be induced by
the solar flare intermittency. The mean monthly temperature datasets cover the
period from 1856 to 2002.Comment: 4 pages, 5 figure
Learning within sustainable educational innovation:An analysis of teachers' perceptions and leadership practice
Innovative initiatives in education often have problems with their sustainability. The present study focuses on three educational innovations that have proved to be sustainable over time. We used a qualitative research approach to study and identify essential features of sustainable educational innovation. Two theoretical frameworks were used to guide the study: the integrated model for sustainable innovation (IMSI) and self-determination theory (SDT). Both frameworks take a different perspective upon learning; IMSI presents learning at the individual level, the team level and the organizational level to be the heart of sustainable innovation, and SDT presents how learning can be improved. The research question focused upon how the SDT concepts of autonomy, competence and relatedness were perceived within sustainable innovation, expressed by the IMSI framework, by teachers and school leaders. Based on our findings we demonstrate that the framework of IMSI and SDT can effectively be applied as a frame of analysis to identify essential features of sustainability in educational innovations and we discuss how concepts of SDT deepen the knowledge of sustainable educational innovation
First airborne water vapor lidar measurements in the tropical upper troposphere and mid-latitudes lower stratosphere: accuracy evaluation and intercomparisons with other instruments
In the tropics, deep convection is the major source of uncertainty in water vapor transport to the upper troposphere and into the stratosphere. Although accurate measurements in this region would be of first order importance to better understand the processes that govern stratospheric water vapor concentrations and trends in the context of a changing climate, they are sparse because of instrumental shortcomings and observational challenges. Therefore, the Falcon research aircraft of the Deutsches Zentrum fĂĽr Luft- und Raumfahrt (DLR) flew a zenith-viewing water vapor differential absorption lidar (DIAL) during the Tropical Convection, Cirrus and Nitrogen Oxides Experiment (TROCCINOX) in 2004 and 2005 in Brazil. The measurements were performed alternatively on three water vapor absorption lines of different strength around 940 nm. These are the first aircraft DIAL measurements in the tropical upper troposphere and in the mid-latitudes lower stratosphere. Sensitivity analyses reveal an accuracy of 5% between altitudes of 8 and 16 km. This is confirmed by intercomparisons with the Fast In-situ Stratospheric Hygrometer (FISH) and the Fluorescent Advanced Stratospheric Hygrometer (FLASH) onboard the Russian M-55 Geophysica research aircraft during five coordinated flights. The average relative differences between FISH and DIAL amount to −3%±8% and between FLASH and DIAL to −8%±14%, negative meaning DIAL is more humid. The average distance between the probed air masses was 129 km. The DIAL is found to have no altitude- or latitude-dependent bias. A comparison with the balloon ascent of a laser absorption spectrometer gives an average difference of 0%±19% at a distance of 75 km. Six tropical DIAL under-flights of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board ENVISAT reveal a mean difference of −8%±49% at an average distance of 315 km. While the comparison with MIPAS is somewhat less significant due to poorer comparison conditions, the agreement with the in-situ hygrometers provides evidence of the excellent quality of FISH, FLASH and DIAL. Most DIAL profiles exhibit a smooth exponential decrease of water vapor mixing ratio in the tropical upper troposphere to lower stratosphere transition. The hygropause with a minimum mixing ratio of 2.5 µmol/mol is found between 15 and 17 km. A high-resolution (2 km horizontal, 0.2 km vertical) DIAL cross section through the anvil outflow of tropical convection shows that the ambient humidity is increased by a factor of three across 100 km
Measurement of the invariant mass distributions for the pp -> ppeta' reaction at excess energy of Q = 16.4 MeV
The proton-proton and proton-eta' invariant mass distributions have been
determined for the pp -> ppeta' reaction at an excess energy of Q = 16.4 MeV.
The measurement was carried out using the COSY-11 detector setup and the proton
beam of the cooler synchrotron COSY. The shapes of the determined invariant
mass distributions are similar to those of the pp -> ppeta reaction and reveal
an enhancement for large relative proton-proton momenta. This result, together
with the fact that the proton-eta interaction is much stronger that the
proton-eta' interaction, excludes the hypothesis that the observed enhancement
is caused by the interaction between the proton and the meson
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