1,229 research outputs found
Biodiversity study of Southern Biscayne Bay and Card Sound 1968-1973
A multi-disciplinary investigation was conducted in southern Biscayne Bay and Card Sound from 1968 to 1973. The purpose of the investigation was to conduct an integrated study of the ecology of southern Biscayne Bay with special emphasis on the effects of the heated effluent from the Turkey Point fossil fuel power plant, and to predict the impact of additional effluent from the planned conversion of the plant to nuclear fuel. The results of this investigation have been discussed in numerous publications. This report contains the unpublished biology data that resulted from the investigation. (PDF contains 44 pages
Methods of regularization for computing orbits in celestial mechanics
Numerical and analytical methods for orbit computation in celestial mechanics during and beyond collision by introduction of regularized coordinate
The quantum origins of skyrmions and half-skyrmions in Cu2OSeO3
The Skyrme-particle, the , was introduced over half a century ago
and used to construct field theories for dense nuclear matter. But with
skyrmions being mathematical objects - special types of topological solitons -
they can emerge in much broader contexts. Recently skyrmions were observed in
helimagnets, forming nanoscale spin-textures that hold promise as information
carriers. Extending over length-scales much larger than the inter-atomic
spacing, these skyrmions behave as large, classical objects, yet deep inside
they are of quantum origin. Penetrating into their microscopic roots requires a
multi-scale approach, spanning the full quantum to classical domain. By
exploiting a natural separation of exchange energy scales, we achieve this for
the first time in the skyrmionic Mott insulator CuOSeO. Atomistic ab
initio calculations reveal that its magnetic building blocks are strongly
fluctuating Cu tetrahedra. These spawn a continuum theory with a skyrmionic
texture that agrees well with reported experiments. It also brings to light a
decay of skyrmions into half-skyrmions in a specific temperature and magnetic
field range. The theoretical multiscale approach explains the strong
renormalization of the local moments and predicts further fingerprints of the
quantum origin of magnetic skyrmions that can be observed in CuOSeO,
like weakly dispersive high-energy excitations associated with the Cu
tetrahedra, a weak antiferromagnetic modulation of the primary ferrimagnetic
order, and a fractionalized skyrmion phase.Comment: 5 pages, 3 figure
Handling and analysis of ices in cryostats and glove boxes in view of cometary samples
Comet nucleus sample return mission and other return missions from planets and satellites need equipment for handling and analysis of icy samples at low temperatures under vacuum or protective gas. Two methods are reported which were developed for analysis of small icy samples and which are modified for larger samples in cometary matter simulation experiments (KOSI). A conventional optical cryostat system was modified to allow for transport of samples at 5 K, ion beam irradiation, and measurement in an off-line optical spectrophotometer. The new system consists of a removable window plug containing nozzles for condensation of water and volatiles onto a cold finger. This plug can be removed in a vacuum system, changed against another plug (e.g., with other windows (IR, VIS, VUV) or other nozzles). While open, the samples can be treated under vacuum with cooling by manipulators (cut, removal, sample taking, irradiation with light, photons, or ions). After bringing the plug back, the samples can be moved to another site of analysis. For handling the 30 cm diameter mineral-ice samples from the KOSI experiments an 80x80x80 cm glove box made out of plexiglass was used. The samples were kept in a liquid nitrogen bath, which was filled from the outside. A stream a dry N2 and evaporating gas from the bath purified the glove box from impurity gases and, in particular, H2O, which otherwise would condense onto the samples
Drug Repurposing for Rare Diseases
Currently, there are about 7000 identified rare diseases, together affecting 10% of the population. However, fewer than 6% of all rare diseases have an approved treatment option, highlighting their tremendous unmet needs in drug development. The process of repurposing drugs for new indications, compared with the development of novel orphan drugs, is a time-saving and cost-efficient method resulting in higher success rates, which can therefore drastically reduce the risk of drug development for rare diseases. Although drug repurposing is not novel, new strategies have been developed in recent years to do it in a systematic and rational way. Here, we review applied methodologies, recent accomplished progress, and the challenges associated in drug repurposing for rare diseases
Electronic Structure and Lattice Relaxation Related to Fe in Mgo
The electronic structure of Fe impurity in MgO was calculated by the linear
muffin-tin orbital--full-potential method within the conventional local-density
approximation (LDA) and making use of the LDA+ formalism. The importance of
introducing different potentials, depending on the screened Coulomb integral
, is emphasized for obtaining a physically reasonable ground state of the
Fe ion configuration. The symmetry lowering of the ion electrostatic
field leads to the observed Jahn--Teller effect; related ligand relaxation
confined to tetragonal symmetry has been optimized based on the full-potential
total energy results. The electronic structure of the Fe ion is also
calculated and compared with that of Fe.Comment: 13 pages + 4 PostScript figures, Revtex 3.0, SISSA-CM-94-00
A Precious-Metal-Free Hybrid Electrolyzer for Alcohol Oxidation Coupled to CO2 -to-Syngas Conversion.
Electrolyzers combining CO2 reduction (CO2 R) with organic substrate oxidation can produce fuel and chemical feedstocks with a relatively low energy requirement when compared to systems that source electrons from water oxidation. Here, we report an anodic hybrid assembly based on a (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) electrocatalyst modified with a silatrane-anchor (STEMPO), which is covalently immobilized on a mesoporous indium tin oxide (mesoITO) scaffold for efficient alcohol oxidation (AlcOx). This molecular anode was subsequently combined with a cathode consisting of a polymeric cobalt phthalocyanine on carbon nanotubes to construct a hybrid, precious-metal-free coupled AlcOx-CO2 R electrolyzer. After three-hour electrolysis, glycerol is selectively oxidized to glyceraldehyde with a turnover number (TON) of ≈1000 and Faradaic efficiency (FE) of 83 %. The cathode generated a stoichiometric amount of syngas with a CO:H2 ratio of 1.25±0.25 and an overall cobalt-based TON of 894 with a FE of 82 %. This prototype device inspires the design and implementation of nonconventional strategies for coupling CO2 R to less energy demanding, and value-added, oxidative chemistry
Fractalization of Torus Revisited as a Strange Nonchaotic Attractor
Fractalization of torus and its transition to chaos in a quasi-periodically
forced logistic map is re-investigated in relation with a strange nonchaotic
attractor, with the aid of functional equation for the invariant curve.
Existence of fractal torus in an interval in parameter space is confirmed by
the length and the number of extrema of the torus attractor, as well as the
Fourier mode analysis. Mechanisms of the onset of fractal torus and the
transition to chaos are studied in connection with the intermittency.Comment: Latex file ( figures will be sent electronically upon
request):submitted to Phys.Rev. E (1996
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