Search results for "Compact"

Holomorphic Aspects of String Theory

1989

A string is a piecewise smooth map of the interval to a manifold M. A closed string is a map of the circle S1 into M. In string theory the strings replace the points of the manifold M as fundamental objects. The enormous amount of work done on quantized string models in physics has been motivated by the hope that the quantum string theory would produce a finite quantized theory of gravity, free of the divergences of the ordinary quantized Einstein theory of gravitation. So far the proof is missing but work is continuing. It has been proposed that some kind of string theory would be the unified theory of all fundamental interactions in physics. However, the fundamental principles of string t…

Rolle's Theorem for Polynomials of Degree Four in a Hilbert Space

2002

AbstractIn an infinite-dimensional real Hilbert space, we introduce a class of fourth-degree polynomials which do not satisfy Rolle's Theorem in the unit ball. Extending what happens in the finite-dimensional case, we show that every fourth-degree polynomial defined by a compact operator satisfies Rolle's Theorem.

Indirect dark matter search with the ANTARES neutrino telescope

2012

Using the data recorded by the ANTARES neutrino telescope during 2007 and 2008, a search for high energy neutrinos coming from the direction of the Sun has been performed. The neutrino selection criteria have been chosen so as to maximize the rejection of the atmospheric background with respect to possible signals produced by the self-annihilation of weakly interactive massive particles accumulated in the centre of the Sun. After data unblinding, the number of neutrinos observed was found to be compatible with background expectations. The results obtained were compared to the fluxes predicted by the Constrained Minimal Supersymmetric Standard Model, and 90% upper limits for this model were …

A heterocyclic oxime from a fungus with anti-juvenile hormone activity

1998

Two fractions obtained after chromatography of dichloromethane extract of Penicillium brevicompactum culture medium showed anti-juvenile hormone activity. One was active when assayed in vivo against Oncopeltus fasciatus third-instar nymphs, whereas the other showed a strong in vitro inhibition of JH III biosynthesis on Locusta migratoria corpora allata. A subfraction of the latter, constituting 97% of this fraction, is a main component that possessed the juvenile hormone biosynthesis inhibitory activity. Chemical characterization of this compound shows a sesquiterpene-like structure, molecular mass of 278.16185 daltons, corresponding to an empirical formula of C15H22N2O3 named brevioxime. E…

Long-term X-ray variability of the microquasar system LS 5039/RX J1826.2−1450

2003

We report on the results of the spectral and timing analysis of a BeppoSAX observation of the microquasar system LS 5039/RX J1826.2-1450. The source was found in a low-flux state with Fx(1-10 keV)= 4.7 x 10^{-12} erg cm^{-2} s^{-1}, which represents almost one order of magnitude lower than a previous RXTE observation 2.5 years before. The 0.1--10 keV spectrum is described by an absorbed power-law continuum with photon-number spectral index Gamma=1.8+-0.2 and hydrogen column density of NH=1.0^{+0.4}_{-0.3} x 10^{22} cm^{-2}. According to the orbital parameters of the system the BeppoSAX observation covers the time of an X-ray eclipse should one occur. However, the 1.6-10 keV light curve does…

A Rainfall Simulator Laboratory Approach to Determine the Impact of Ash Depth on Runoff Generation and Soil Losses

2020

Ash cover the forest fire affected soil for some weeks or months and act as a key factor to determine the soil and water losses. Ash depth is researched here to determine how affect the soil detachment and the runoff generation. Seventy rainfall simulation experiments on paired 0.50 m2 plots (five plots with 0, 1, 2, 3, 5, 10, 15- and 30-mm ash depth), and repeated one week later) under thunderstorms of 48 mmh-1 for one hour were carried out under laboratory conditions. In the first experiment, after the bed of ash was applied, the results show that ash depth determines the runoff rates as they reduce the discharge from 23.1% to 13.9%. The sediment concentration increased from 23.8 till 38.…

Evaluation of Green Roof Ageing Effects on Substrate Hydraulic Characteristics

2020

The vegetated substrate of green roofs may undergo various chemical and physical changes with time. Minidisk infiltrometer (MDI) tests were conducted to assess the short-term variations of the near-saturated hydraulic conductivity, K0, in the extensive green roof test plot established at the University of Palermo. Sampling was repeated four times: before planting (Age 0) and then after four months (Age 1), seven months (Age 2) and ten months (Age 3). A total of 144 infiltration tests were conducted at two pressure heads, h0 = −3 cm and h0 = −0.5 cm and infiltration data analysed by the Zhang (Soil Science Society of America Journal 61(4):1024–1030, 1997) model. Both K-3 and K-0.5 underwent …

Champs de vecteurs analytiques et champs de gradients

2002

A theorem of Łojasiewicz asserts that any relatively compact solution of a real analytic gradient vector field has finite length. We show here a generalization of this result for relatively compact solutions of an analytic vector field X with a smooth invariant hypersurface, transversally hyperbolic for X, where the restriction of the field is a gradient. This solves some instances of R. Thom's Gradient Conjecture. Furthermore, if the dimension of the ambient space is three, these solutions do not oscillate (in the sense that they cut an analytic set only finitely many times); this can also be applied to some gradient vector fields.

Boundary regularity and the uniform convergence of quasiconformal mappings

1979

Evolution of OO Methods: the unified case

1997

This paper takes an evaluative look into OO methods and especially the evolution of the new snified method from its ancestors, OMT and OODA. The paper ries to classify the components of the earlier ethods and identify the parts that have been taken into the Unified ethod. The research applies the method metrics approach. For the sake of compactness we limit ourselves to the class diagram technique of all methods. We make observations about the number of concepts in each variation and show how the metrics can be used to analyse the changes in the techniques.