777 research outputs found
Kartlegging av et tønnedeponi i sjøen utenfor Aspond, Indre Oslofjord 1996. Utbredelse, tilstand og miljøgifter
Totalt 0.65 km² av sjøbunnen vest for Aspond ble undersøkt mht. forekomst av og tilstand til deponerte tønner. Kartleggingen omfattet bruk av miniubåt, video, dykking og miljøgiftanalyser av tønneinnhold og sedimenter. Hoveddeponiet antas å dekke et areal på 0,1 km² med flest tønner på 15-25 m vanndyp. Det ble også registrert forholdsvis mange tønner på grunt vann, samt enkelte spredt i dypere deler av området. Totalt anslag ca. 6000 tønner og Jerry-kanner. Tønnenes tilstand var svært dårlig og sjøbunnen innenfor deponiet bar preg av fragmenter fra det opprinnelige tønnematerialet. Innholdet i et mindre antall utvalgte tønner viste seg å inneholde markert til kraftig forhøyede konsentrasjoner av ulike metaller og olje-/tjærerester. Det ble også registrert overkonsentrasjoner av PCB og spor av andre persistente klororganiske forbindelser. Samlet indikerte målingene i sedimentene en forholdsvis dårlig sedimenttilstand lokalt i deponiet, men at spredningen av miljøgifter til omgivelsene for øvrig har vært svært begrenset
Magnetic systems at criticality: different signatures of scaling
Different aspects of critical behaviour of magnetic materials are presented
and discussed. The scaling ideas are shown to arise in the context of purely
magnetic properties as well as in that of thermal properties as demonstrated by
magnetocaloric effect or combined scaling of excess entropy and order
parameter. Two non-standard approaches to scaling phenomena are described. The
presented concepts are exemplified by experimental data gathered on four
representatives of molecular magnets.Comment: 33 pages, 16 figure
On the 3D steady flow of a second grade fluid past an obstacle
We study steady flow of a second grade fluid past an obstacle in three space
dimensions. We prove existence of solution in weighted Lebesgue spaces with
anisotropic weights and thus existence of the wake region behind the obstacle.
We use properties of the fundamental Oseen tensor together with results
achieved in \cite{Koch} and properties of solutions to steady transport
equation to get up to arbitrarily small \ep the same decay as the Oseen
fundamental solution
Directional approach to spatial structure of solutions to the Navier-Stokes equations in the plane
We investigate a steady flow of incompressible fluid in the plane. The motion
is governed by the Navier-Stokes equations with prescribed velocity
at infinity. The main result shows the existence of unique solutions for
arbitrary force, provided sufficient largeness of . Furthermore a
spacial structure of the solution is obtained in comparison with the Oseen
flow. A key element of our new approach is based on a setting which treats the
directino of the flow as \emph{time} direction. The analysis is done in
framework of the Fourier transform taken in one (perpendicular) direction and a
special choice of function spaces which take into account the inhomogeneous
character of the symbol of the Oseen system. From that point of view our
technique can be used as an effective tool in examining spatial asymptotics of
solutions to other systems modeled by elliptic equations
Stability of composite plates under varying axial forces
The aim of this contribution is to show how the known theories of elastic plates
can be extended in order to describe property arbitrary inhomogeneous of the
plates materiał for dynamics stability. Each layer being the composite components
is taken to be inhomogeneous and anisotropic. The perfect contact between the
components of the plate is assumed
Arabinogalactan-protein and pectin epitopes in relation to an extracellular matrix surface network and somatic embryogenesis and callogenesis in Trifolium nigrescens Viv
The formation of an extracellular matrix surface network (ECMSN), and associated changes in the distribution of arabinogalactan-protein and pectin epitopes, have been studied during somatic embryogenesis (SE) and callogenesis of Trifolium nigrescens Viv. Scanning electron microscopy observations revealed the occurrence of an ECMSN on the surface of cotyledonary-staged somatic embryos as well as on the peripheral, non-regenerating callus cells. The occurrence of six AGP (JIM4, JIM8, JIM13, JIM16, LM2, MAC207) and four pectin (JIM5, JIM7, LM5, LM6) epitopes was analysed during early stages of SE, in cotyledonary-staged somatic embryos and in non-embryogenic callus using monoclonal antibodies. The JIM5 low methyl-esterified homogalacturonan (HG) epitope localized to ECMSN on the callus surface but none of the epitopes studied were found to localize to ECMSN over mature somatic embryos. The LM2 AGP epitope was detected during the development of somatic embryos and was also observed in the cell walls of meristematic cells from which SE was initiated. The pectic epitopes JIM5, JIM7, LM5 and LM6 were temporally regulated during SE. The LM6 arabinan epitope, carried by side chains of rhamnogalacturonan-I (RG-I), was detected predominantly in cells of embryogenic swellings, whilst the LM5 galactan epitope of RG-I was uniformly distributed throughout the ground tissue of cotyledonary-staged embryoids but not detected at the early stages of SE. Differences in the distribution patterns of low and high methyl-esterified HG were detected: low ester HG (JIM5 epitope) was most abundant during the early steps of embryo formation and highly methyl-esterified form of HG (JIM7 epitope) became prevalent during embryoid maturation
A Default Logic Patch for Default Logic
International audienceThis paper is about the fusion of multiple information sources represented using default logic. More precisely, the focus is on solving the problem that occurs when the standard-logic knowledge parts of the sources are contradictory, as default theories trivialize in this case. To overcome this problem, it is shown that replacing each formula belonging to Minimally Unsatisfiable Subformulas by a corresponding supernormal default allows appealing features. Moreover, it is investigated how these additional defaults interact with the initial defaults of the theory. Interestingly, this approach allows us to handle the problem of default theories containing inconsistent standard-logic knowledge, using the default logic framework itself
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