35,328 research outputs found
Arrival direction distribution of cosmic rays of energy 10 (18) eV
The Haverah Park air-shower experiment recorded over 8500 events with primary energy 10 to the 18th power eV between 1963 and 1983. An analysis of these events for anisotropies in celestial and galactic coordinates is reported. No very striking anisotropies are observed
Observations of Cygnus X-3 above 10(15) eV from 1979 - 1984
The ultra high energy gamma-ray source, cygnus X-3, has been observed more or less continuously with an array sensitive to 10 to the 15th power ev primaries between 1 Jan. 1979 and 31 Dec. 1984. There is evidence for time variability in the phase of gamma-ray emission over this period
Spontaneous Jamming in One-Dimensional Systems
We study the phenomenon of jamming in driven diffusive systems. We introduce
a simple microscopic model in which jamming of a conserved driven species is
mediated by the presence of a non-conserved quantity, causing an effective long
range interaction of the driven species. We study the model analytically and
numerically, providing strong evidence that jamming occurs; however, this
proceeds via a strict phase transition (with spontaneous symmetry breaking)
only in a prescribed limit. Outside this limit, the nearby transition
(characterised by an essential singularity) induces sharp crossovers and
transient coarsening phenomena. We discuss the relevance of the model to two
physical situations: the clustering of buses, and the clogging of a suspension
forced along a pipe.Comment: 8 pages, 4 figures, uses epsfig. Submitted to Europhysics Letter
Qualitative evidence syntheses : assessing the relative contributions of multiâcontext and singleâcontext reviews
Aims
To examine the strengths and weaknesses of multiâcontext (international) qualitative evidence syntheses in comparison with singleâcontext (typically singleâcountry) reviews. We compare a multiâcountry synthesis with singleâcontext syntheses on facilityâbased delivery in Nigeria and Kenya.
Design
Discussion Paper.
Background
Qualitative evidence increasingly contributes to decisionâmaking. International organisations commission multiâcontext reviews of qualitative evidence to gain a comprehensive picture of similarities and differences across comparable (e.g. lowâ and middleâincome) countries. Such syntheses privilege breadth over contextual detail, risking inappropriate interpretation and application of review findings. Decisionâmakers value singleâcontext syntheses that account for the contexts of their populations and health services. We explore how findings from multiâ and singleâcontext syntheses contribute against a conceptual framework (adequacy, coherence, methodological limitations and relevance) that underpins the GRADE Confidence in Evidence of Reviews of Qualitative Evidence approach.
Data sources
Included studies and findings from a multiâcontext qualitative evidence synthesis (2001â2013) and two singleâcontext syntheses (Nigeria, 2006â2017; and Kenya, 2002â2016; subsequently, updated and revised).
Findings
Singleâcontext reviews contribute cultural, ethnic and religious nuances as well as specific health system factors (e.g. use of a voucher system). Multiâcontext reviews contribute to universal health concerns and to generic health system concerns (e.g. access and availability).
Implications for nursing: Nurse decisionâmakers require relevant, timely and contextâsensitive evidence to inform clinical and managerial decisionâmaking. This discussion paper informs future commissioning and use of multiâ and singleâcontext qualitative evidence syntheses.
Conclusion
Multiâ and singleâcontext syntheses fulfil complementary functions. Singleâcontext syntheses add nuances not identifiable within the remit and timescales of a multiâcontext review
Research Output and Pattern of Publication among Faculty in Nigerian Private Universities: Babcock University Experience
The paper investigates the patterns of research output publications of faculty of Babcock University, Nigeria. Survey design was adopted; the population for the study consists of 154 faculty of Babcock University. Data for the study was collected using questionnaire titled Patterns of Research Output and Publications among Faculty in Private Universities (ROPAFPU). Data collected was analyzed using descriptive statistics, frequency counts and simple percentage while the hypotheses were tested using Product Moment Correlation and chi- square. The result of the hypotheses showed that there is significant relationship between the status of faculty and pattern of research output publication, there is also significant relationship between the qualification and pattern of research output publication of the faculty and there is also significance difference in pattern of publications based on gender. Recommendations made for the improvement of research output publication of the faculty include mentoring, collaboration with foreign colleagues in research and publication; male lecturers should endeavor to publish more journal publications and female faculty be encouraged to increase their seminar presentation as well as text books publishing. Key Words: Research output, Babcock University Faculty research output, Research and national development, Babcock University Faculty Publication pattern
Coupled Fluctuations near Critical Wetting
Recent work on the complete wetting transition has emphasized the role played
by the coupling of fluctuations of the order parameter at the wall and at the
depinning fluid interface. Extending this approach to the wetting transition
itself we predict a novel crossover effect associated with the decoupling of
fluctuations as the temperature is lowered towards the transition temperature
T_W. Using this we are able to reanalyse recent Monte-Carlo simulation studies
and extract a value \omega(T_W)=0.8 at T_W=0.9T_C in very good agreement with
long standing theoretical predictions.Comment: 4 pages, LaTex, 1 postscript figur
Asymmetric exclusion model with several kinds of impurities
We formulate a new integrable asymmetric exclusion process with
kinds of impurities and with hierarchically ordered dynamics.
The model we proposed displays the full spectrum of the simple asymmetric
exclusion model plus new levels. The first excited state belongs to these new
levels and displays unusual scaling exponents. We conjecture that, while the
simple asymmetric exclusion process without impurities belongs to the KPZ
universality class with dynamical exponent 3/2, our model has a scaling
exponent . In order to check the conjecture, we solve numerically the
Bethe equation with N=3 and N=4 for the totally asymmetric diffusion and found
the dynamical exponents 7/2 and 9/2 in these cases.Comment: to appear in JSTA
Theoretical and numerical studies of chemisorption on a line with precursor layer diffusion
We consider a model for random deposition of monomers on a line with
extrinsic precursor states. As the adsorbate coverage increases, the system
develops non-trivial correlations due to the diffusion mediated deposition
mechanism. In a numeric simulation, we study various quantities describing the
evolution of the island structure. We propose a simple, self-consistent theory
which incorporates pair correlations. The results for the correlations, island
density number, average island size and probabilities of island nucleation,
growth and coagulation show good agreement with the simulation data.Comment: 17 pages(LaTeX), 11 figures(1 PS file, uuencoded), submmited to Phys.
Rev.
- âŠ