297 research outputs found
Sideritis arborescens Salzm. ex Bentham y Sideritis x gaditana Rouy en Andalucía Occidental
It is described at the report the taxonomicous characters of the different subespecies of Sideritis arborescens Salzm. ex Bentham and of Sideritis x gaditana Rouy. It is also included for each taxon, type, distribution and material studied from West Andalucia.Se describen los caracteres taxonómicos de las distintas subespecies de Sideritis arborescens Salzm. ex Bentham y de Sideritis x gaditana buy. Se incluye además para cada taxon, tipo, distribución y material estudiado en Andalucia Occidental
Método novedoso para la deposición de óxidos metálicos en aerogeles de carbono con potencial uso en desionización capacitiva de agua salina
Large Deformation Effects in the N = Z 44Ti Compound Nucleus
The N = Z 44Ti* nucleus has been populated in Fusion Evaporation process at
very high excitation energies and angular momenta using two entrance channels
with different mass-asymmetry. The deformation effects in the rapidly rotating
nuclei have been investigated through the energy distribution of the
alpha-particle combined to statistical-model calculations. In the case of
low-multiplicity events, the ratio between first particle emitted has been
measured and shows significant disagreement with the predictions of the
statistical-model. This may explain The large discrepancies observed in proton
energy spectra measured in previous experiments performed in the same mass
region.Comment: Proceeding of the 10th International Conference on Nuclear Reaction
Mechanisms, Varenna Italy, June 9-13 2003. 10 pages, 6 figures, 1 tabl
Efecto de las condiciones de prepolimerización en aerogeles nitrogenados y su influencia en desionizacion capacitiva
Binary reaction decays from 24Mg+12C
Charged particle and gamma decays in 24Mg* are investigated for excitation
energies where quasimolecular resonances appear in 12C+12C collisions. Various
theoretical predictions for the occurence of superdeformed and hyperdeformed
bands associated with resonance structures with low spin are discussed within
the measured 24Mg* excitation energy region. The inverse kinematics reaction
24Mg+12C is studied at E_lab(24Mg) = 130 MeV, an energy which enables the
population of 24Mg states decaying into 12C+12C resonant break-up states.
Exclusive data were collected with the Binary Reaction Spectrometer in
coincidence with EUROBALL IV installed at the VIVITRON Tandem facility at
Strasbourg. Specific structures with large deformation were selectively
populated in binary reactions and their associated gamma decays studied.
Coincident events associated with inelastic and alpha-transfer channels have
been selected by choosing the excitation energy or the entry point via the
two-body Q-values. The analysis of the binary reaction channels is presented
with a particular emphasis on 24Mg-gamma, 20Ne-gamma and 16O-gamma
coincidences. New information (spin and branching ratios) is deduced on
high-energy states in 24Mg and 16O, respectively.Comment: 27 pages, 8 figures, 1 tabl
Synthesis of Porous and Mechanically Compliant Carbon Aerogels Using Conductive and Structural Additives
We report the synthesis of conductive and mechanically compliant monolithic carbon
aerogels prepared by sol-gel polycondensation of melamine-resorcinol-formaldehyde (MRF) mixtures
by incorporating diatomite and carbon black additives. The resulting aerogels composites displayed
a well-developed porous structure, confirming that the polymerization of the precursors is not
impeded in the presence of either additive. The aerogels retained the porous structure after etching
off the siliceous additive, indicating adequate cross-linking of the MRF reactants. However, the
presence of diatomite caused a significant fall in the pore volumes, accompanied by coarsening
of the average pore size (predominance of large mesopores and macropores). The diatomite also
prevented structural shrinkage and deformation of the as-prepared monoliths upon densification
by carbonization, even after removal of the siliceous framework. The rigid pristine aerogels became
more flexible upon incorporation of the diatomite, favoring implementation of binderless monolithic
aerogel electrodes
Reaction mechanisms in 24Mg+12C and 32S+24Mg
The occurence of "exotic" shapes in light N=Z alpha-like nuclei is
investigated for 24Mg+12C and 32S+24Mg. Various approaches of superdeformed and
hyperdeformed bands associated with quasimolecular resonant structures with low
spin are presented. For both reactions, exclusive data were collected with the
Binary Reaction Spectrometer in coincidence with EUROBALL IV installed at the
VIVITRON Tandem facility of Strasbourg. Specific structures with large
deformation were selectively populated in binary reactions and their associated
-decays studied. The analysis of the binary and ternary reaction
channels is discussed.Comment: 7 pages, 4 figures, Paper presented at the Fusion08 International
Conference on New Aspects of Heavy Ion Collisions Near the Coulomb Barrier,
Chicago. Proceedings to be published by AIP Conference Proceedings Illinois,
USA, September 22-26, 200
Clusters in Light Nuclei
A great deal of research work has been undertaken in the alpha-clustering
study since the pioneering discovery, half a century ago, of 12C+12C molecular
resonances. Our knowledge of the field of the physics of nuclear molecules has
increased considerably and nuclear clustering remains one of the most fruitful
domains of nuclear physics, facing some of the greatest challenges and
opportunities in the years ahead. In this work, the occurence of "exotic"
shapes in light N=Z alpha-like nuclei is investigated. Various approaches of
superdeformed and hyperdeformed bands associated with quasimolecular resonant
structures are presented. Results on clustering aspects are also discussed for
light neutron-rich Oxygen isotopes.Comment: 12 pages, 5 figures. Invited Talk presented by C. Beck at the
Zakopane Conference on Nuclear Physics "Extremes of the Nuclear Landscape"
XLV in the series of Zakopane Schools of Physics - International Symposium -
Zakopane, Poland, August 30 - September 5, 2010.To be publihed in Acta
Physica Polonica B42 no 3, March 201
A quasi-experimental study of impacts of Tanzania’s Wildlife Management Areas on rural livelihoods and wealth
Since the 2000s, Tanzania’s natural resource management policy has emphasised Wildlife Management Areas (WMAs), designed to promote wildlife and biodiversity conservation, poverty alleviation and rural development. We carried out a quasi-experimental impact evaluation of social impacts of WMAs, collecting data from 24 villages participating in 6 different WMAs across two geographical regions, and 18 statistically matched control villages. Across these 42 villages, we collected participatory wealth ranking data for 13,578 households. Using this as our sampling frame, we conducted questionnaire surveys with a stratified sample of 1,924 household heads and 945 household heads’ wives. All data were collected in 2014/15, with a subset of questions devoted to respondents’ recall on conditions that existed in 2007, when first WMAs became operational. Questions addressed household demographics, land and livestock assets, resource use, income-generating activities and portfolios, participation in natural resource management decision-making, benefits and costs of conservation. Datasets permit research on livelihood and wealth trajectories, and social impacts, costs and benefits of conservation interventions in the context of community-based natural resource management
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