26,982 research outputs found
Non-degenerate colorings in the Brook's Theorem
Let and be two integers. We will call a proper coloring
of the graph a \textit{-nondegenerate}, if for any vertex of
with degree at least there are at least vertices of different colors
adjacent to it. In our work we prove the following result, which generalizes
Brook's Theorem. Let and be a graph without cliques on
vertices and the degree of any vertex in this graph is not greater than .
Then for every integer there is a proper -nondegenerate vertex
-coloring of , where During the primary proof,
some interesting corollaries are derived.Comment: 18 pages, 10 figure
The use of remote sensing in solving Florida's geological and coastal engineering problems
LANDSAT imagery and NASA high altitude color infrared (CIR) photography were used to select suitable sites for sanitary landfill in Volusia County, Florida and to develop techniques for preventing sand deposits in the Clearwater inlet. Activities described include the acquisition of imagery, its analysis by the IMAGE 100 system, conventional photointerpretation, evaluation of existing data sources (vegetation, soil, and ground water maps), site investigations for ground truth, and preparation of displays for reports
A holistic multimodal approach to the non-invasive analysis of watercolour paintings
A holistic approach using non-invasive multimodal imaging and spectroscopic techniques to study the materials (pigments, drawing materials and paper) and painting techniques of watercolour paintings is presented. The non-invasive imaging and spectroscopic techniques include VIS-NIR reflectance spectroscopy and multispectral imaging, micro-Raman spectroscopy, X-ray fluorescence spectroscopy (XRF) and optical coherence tomography (OCT). The three spectroscopic techniques complement each other in pigment identification. Multispectral imaging (near infrared bands), OCT and micro-Raman complement each other in the visualisation and identification of the drawing material. OCT probes the microstructure and light scattering properties of the substrate while XRF detects the elemental composition that indicates the sizing methods and the filler content . The multiple techniques were applied in a study of forty six 19th century Chinese export watercolours from the Victoria & Albert Museum (V&A) and the Royal Horticultural Society (RHS) to examine to what extent the non-invasive analysis techniques employed complement each other and how much useful information about the paintings can be extracted to address art conservation and history questions
FIP Bias Evolution in a Decaying Active Region
Solar coronal plasma composition is typically characterized by first
ionization potential (FIP) bias. Using spectra obtained by Hinode's EUV Imaging
Spectrometer (EIS) instrument, we present a series of large-scale, spatially
resolved composition maps of active region (AR) 11389. The composition maps
show how FIP bias evolves within the decaying AR from 2012 January 4-6.
Globally, FIP bias decreases throughout the AR. We analyzed areas of
significant plasma composition changes within the decaying AR and found that
small-scale evolution in the photospheric magnetic field is closely linked to
the FIP bias evolution observed in the corona. During the AR's decay phase,
small bipoles emerging within supergranular cells reconnect with the
pre-existing AR field, creating a pathway along which photospheric and coronal
plasmas can mix. The mixing time scales are shorter than those of plasma
enrichment processes. Eruptive activity also results in shifting the FIP bias
closer to photospheric in the affected areas. Finally, the FIP bias still
remains dominantly coronal only in a part of the AR's high-flux density core.
We conclude that in the decay phase of an AR's lifetime, the FIP bias is
becoming increasingly modulated by episodes of small-scale flux emergence, i.e.
decreasing the AR's overall FIP bias. Our results show that magnetic field
evolution plays an important role in compositional changes during AR
development, revealing a more complex relationship than expected from previous
well-known Skylab results showing that FIP bias increases almost linearly with
age in young ARs (Widing Feldman, 2001, ApJ, 555, 426)
Particulate and aerosol detector
A device is described for counting aerosols and sorting them according to either size, mass or energy. The component parts are an accelerator, a capacitor sensor and a readout. The accelerator is a means for accelerating the aerosols toward the face of the capacitor sensor with such force that they partially penetrate the capacitor sensor, momentarily discharging it. The readout device is a means for counting the number of discharges of the capacitor sensor and measuring the amplitudes of these different discharges. The aerosols are accelerated by the accelerator in the direction of the metal layer with such force that they penetrate the metal and damage the oxide layers, thereby allowing the electrical charge on the capacitor to discharge through the damaged region. Each incident aerosol initiates a discharge path through the capacitor in such a fashion as to vaporize the conducting path. Once the discharge action is complete, the low resistance path no longer exists between the two capacitor plates and the capacitor is again able to accept a charge. The active area of the capacitor is reduced in size by the damaged area each time a discharge occurs
A New Genus and Species of Cryptogonimid from Lutjanus Spp. (Pisces: Lutjanidae) on the Great Barrier Reef and New Caledonia
Lobosorchis tibaldiae n. gen. and n. sp. (Digenea: Cryptogonimidae) is described from the intestine, pyloric ceca, and rectum of 2 species of Lutjanus (Pisces: Lutjanidae), Lutjanus carponotatus and Lutjanus fulviflamma, from the Great Barrier Reef, Queensland, Australia, and New Caledonia. The genus is tentatively placed in the Neochasminae and is distinguished within the Cryptogonimidae by the combination of follicular testes, oral spines, and vitelline follicles restricted to the anterior region of the body not extending posteriorly to the ventral sucker
Plasma composition in a sigmoidal anemone active region
Using spectra obtained by the EIS instrument onboard Hinode, we present a
detailed spatially resolved abundance map of an active region (AR)-coronal hole
(CH) complex that covers an area of 359 arcsec x 485 arcsec. The abundance map
provides first ionization potential (FIP) bias levels in various coronal
structures within the large EIS field of view. Overall, FIP bias in the small,
relatively young AR is 2-3. This modest FIP bias is a consequence of the AR
age, its weak heating, and its partial reconnection with the surrounding CH.
Plasma with a coronal composition is concentrated at AR loop footpoints, close
to where fractionation is believed to take place in the chromosphere. In the
AR, we found a moderate positive correlation of FIP bias with nonthermal
velocity and magnetic flux density, both of which are also strongest at the AR
loop footpoints. Pathways of slightly enhanced FIP bias are traced along some
of the loops connecting opposite polarities within the AR. We interpret the
traces of enhanced FIP bias along these loops to be the beginning of
fractionated plasma mixing in the loops. Low FIP bias in a sigmoidal channel
above the AR's main polarity inversion line where ongoing flux cancellation is
taking place, provides new evidence of a bald patch magnetic topology of a
sigmoid/flux rope configfiuration.Comment: For on-line animation, see
http://www.mssl.ucl.ac.uk/~db2/fip_intensity.gif. Accepted by Ap
Automated water monitor system field demonstration test report. Volume 1: Executive summary
A system that performs water quality monitoring on-line and in real time much as it would be done in a spacecraft, was developed and demonstrated. The system has the capability to determine conformance to high effluent quality standards and to increase the potential for reclamation and reuse of water
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