600 research outputs found
Effect of different diets on the development, mortality, survival, food uptake and fecundity of Tupiocoris cucurbitaceus (Hemiptera: Miridae)
Several Miridae (Hemiptera) species have been identified as useful predators for biological control of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae). There is interest in determining the effects of different diets on Tupiocoris cucurbitaceus (Spinola) (Hemiptera: Miridae) in order to facilitate their breeding and use in biological control. Given that mirids can be both phytophagous and zoophytophagous, the developmental time, mortality, survival, feeding and fecundity of this species on tomato and tobacco leaves with and without the addition of T. vaporariorum or Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs were studied. To determine embryonic duration, T. cucurbitaceus was allowed to oviposit on tobacco plants for 24 h at 26 °C, 83% RH and a photoperiod of 16:8 h L:D. The time of onset of the first instar nymphs was recorded. Subsequently, these nymphs fed on different diets on 9 cm × 1.5 cm plates under the same environmental conditions. Results showed that diet influences the duration of development in T. cucurbitaceus, with nymphal stadia being shorter and the adult stadium being longer when fed prey than when not fed prey. With the addition of prey, nymphal mortality was generally lower and adult survival was higher. The high consumption of T. vaporariorum eggs by T. cucurbitaceus suggests the need for subsequent studies on the latter for inclusion of this species in biological control programs in greenhouses
Análisis de variables relacionadas con el acceso y desempeño de las funciones directiva y docente en las nuevas universidades populares españolas. Un estudio a nivel nacional
Cada vez y con más frecuencia las instituciones
de educación no formal están cobrando una
mayor importancia en la formación continua de nuestros
ciudadanos. El presente trabajo recoge una investigación
realizada a nivel nacional sobre una de estas
instituciones que en la actualidad cuenta con más de
dos millones de alumnos. Estamos hablando de las Universidades
Populares españolas que en la actualidad se
encuentran expandidas por veintidós provincias de once
comunidades autónomas: Andalucía, Aragón, Castilla
La Mancha, Castilla León, Extremadura, Galicia, La
Rioja, Madrid, Murcia y Valencia. En esta investigación
se utilizaron tres tipos de cuestionarios dirigidos a cada uno de los estamentos ligados a este proyecto: los directivos,
los monitores y los alumnos. A su vez, se realizó
un estudio de caso en la Universidad Popular de
Loja (Granada), con el objetivo de dotar de significado
a los datos estadísticos obtenidos del estudio a nivel nacional.
De esta forma se han caracterizado y descrito
las principales tareas de las Universidades Populares españolas
y la visión que de ellas tienen los tres grupos
implicados en su vida diari
Atención odontológica en comunidades tobas de Argentina. Construyendo salud
La experiencia que aquí presentamos se ha desarrollado en Colonia Aborigen, Provincia del Chaco, República Argentina. Se trata de un trabajo con un perfil netamente educativo, preventivo y comunitario. Desde un enfoque que jerarquiza los tres niveles de la prevención tiene como propósito llegar anticipadamente antes que la situación no deseada se instale. De allí, la importancia de incorporar una mentalidad preventiva en los profesionales, estudiantes de odontología y en toda la población. La salud y la prevención de enfermedades no dependen exclusivamente de los gobiernos y sus programas sanitarios, sino también del compromiso de toda la comunidad y especialmente de sus referentes, que de un modo activo interpretan que son parte fundamental del bienestar y la primera barrera de defensa a instalar en una comunidad, pueblo o barrio. La salud de los pueblos es calidad de vida, que obligatoriamente necesitan de las políticas de estado para remover las causas económicas, sociales y culturales que la condicionan. Intentar resolver los conflictos de los niños, jóvenes, hombres y mujeres de Colonia Aborigen fue nuestro desafío, ayudar a mejorar su vida diaria y contribuir en la construcción de su felicidad. Para lograr nuestro objetivo siempre tuvimos presente los elementos que garantizan el derecho a la salud de los pueblo: Disponibilidad, Accesibilidad, Calidad, Aceptabilidad y Equidad, obligándonos a respetarlos, protegerlos y cumpliendo con nuestro deber de odontólogos y docentes de la Facultad de Odontología de la Universidad Nacional de Córdoba desarrollando acciones tendientes a restaurar el derecho perdido.publishedVersio
Testing postcombustion CO2 capture with CaO in a 1.7 MWt pilot facility
AbstractCalcium looping, CaL, is a new and rapidly developing technology that makes use of CaO as a high temperature regenerable sorbent of CO2. Previous theoretical and lab scale studies have shown that this technology could lead to a substantial reduction in the cost of CO2 capture and energy penalties because heat can be effectively recovered from this high temperature solid looping system. We report in this paper on the first results from a pilot plant designed to demonstrate the viability of postcombustion capture of CO2 using CaL under conditions comparable to those expected in a large scale plant. The pilot includes two interconnected circulating fluidized bed reactors of 15 m height: a CO2 absorber (carbonator) able to treat up to 2400kg/h (equivalent to about 1.7 MWth), and an oxy-fired CFB calciner with a firing power between 1-3 MWth. CO2 capture efficiencies over 90% have been experimentally observed, including continuous operation with highly cycled solids in the system (i.e. with modest CO2 carrying capacities). SO2 capture is shown to be extremely high, with concentrations of SO2 well below 10 ppmv at the exit of the carbonator. Closure of carbon and sulfur balances is satisfactory. These results should be valuable base for model validation and scaling up purposes in future stages of the EU FP7 “CaOling” project, under which this investigation has been carried out
New iron(II) cyclopentadienyl derivative complexes: synthesis and antitumor activity against human leukemia cancer cells
A new family of 'FeII(h5-C5H5)' half sandwich compounds bearing a N-heteroaromatic ligand coordinated to the iron center by a nitrile functional group has been synthesized and fully characterized by NMR and UVeVis spectroscopy. X-ray analysis of single crystal was achieved for complexes 1 and 3, which crystallized in the monoclinic P21/c and monoclinic P21/n space groups, respectively. Studies of interaction of these five new complexes with plasmid pBR322 DNA by atomic force microscopy showed very strong and different types of interaction. Antiproliferative tests were examined on human leukemia cancer cells (HL-60) using the MTT assay, and the IC50 values revealed excellent antiproliferative activity compared to cisplatin
Theoretical analysis of neutron scattering results for quasi-two dimensional ferromagnets
A theoretical study has been carried out to analyse the available results
from the inelastic neutron scattering experiment performed on a quasi-two
dimensional spin-1/2 ferromagnetic material . Our formalism is based
on a conventional semi-classical like treatment involving a model of an ideal
gas of vortices/anti-vortices corresponding to an anisotropic XY Heisenberg
ferromagnet on a square lattice. The results for dynamical structure functions
for our model corresponding to spin-1/2, show occurrence of negative values in
a large range of energy transfer even encompassing the experimental range, when
convoluted with a realistic spectral window function. This result indicates
failure of the conventional theoretical framework to be applicable to the
experimental situation corresponding to low spin systems. A full quantum
formalism seems essential for treating such systems.Comment: 16 pages, 6 figures, 1 Table Submitted for publicatio
Scaling behaviour of lattice animals at the upper critical dimension
We perform numerical simulations of the lattice-animal problem at the upper
critical dimension d=8 on hypercubic lattices in order to investigate
logarithmic corrections to scaling there. Our stochastic sampling method is
based on the pruned-enriched Rosenbluth method (PERM), appropriate to linear
polymers, and yields high statistics with animals comprised of up to 8000
sites. We estimate both the partition sums (number of different animals) and
the radii of gyration. We re-verify the Parisi-Sourlas prediction for the
leading exponents and compare the logarithmic-correction exponents to two
partially differing sets of predictions from the literature. Finally, we
propose, and test, a new Parisi-Sourlas-type scaling relation appropriate for
the logarithmic-correction exponents.Comment: 10 pages, 5 figure
Tsallis Information Measure, Multiresolution Analysis, and Nonlinear Dynamics
Projet PROMATHWe undertake the study of signals originated in time-dependent nonlinear systems by recourse to a wavelet based multiresolution analysis, as adapted to a non-extensive (Tsallis) scenario. Diverse applications are discussed that illustrate the fact that a Tsallis environment seems to provide one with more detailed information than the conventional Shannon one
Materials for Sustainable Nuclear Energy - The Strategic Research Agenda (SRA) of the Joint Programme on Nuclear Materials (JPNM) of the European Energy Research Alliance (EERA)
This Strategic Research Agenda (SRA) has been prepared by the EERA-JPNM, based on a wide consultation with the scientific and industrial community involved, to identify the research lines to be pursued in the EU to ensure that suitable structural and fuel materials are available for the design, licensing, construction and safe long-term operation of GenIV nuclear systems.
Three Grand Challenges have been identified, namely: (i) Elaborate design correlations, assessment and test procedures for the structural and fuel materials that have been selected for the demonstrators under the service conditions expected; (ii) Develop physical models coupled to advanced microstructural characterization to achieve high-level understanding and predictive capability; (iii) Develop innovative materials solutions and fabrication processes of industrial application to achieve superior materials properties, to increase safety and improve efficiency and economy.
For structural materials, the requirement of 60 years design lifetime for non-replaceable components is in perspective the most demanding requirement, which includes under its umbrella several issues related with the reasonable prediction of long-term degradation processes: high temperature processes (creep, fatigue, thermal ageing), compatibility with –especially- heavy liquid metal and helium coolants, and effects of low flux prolonged irradiation, with emphasis on welded components in all cases. In terms of testing, there is a need for standardization, especially for sub-size and miniature specimens. The modelling, supported by microstructural characterization, has as its main objective the development of suitable microstructure evolution models to be used as input to models for the mechanical behaviour under irradiation and at high temperature, eventually linking with fracture mechanics. Specific developments are required for coolant compatibility models, as well as for models in support of the use of charged particle irradiation for the screening of new materials solutions, such as those listed above.
Concerning fuel materials, the properties and processes that govern its behaviour in pile, on which research effort is focused, are: margin to melting (establishment of phase diagrams and evolution of thermal properties), atomic transport properties and ensuing microstructural evolution, fission product (non-gaseous) and helium (gas) behaviour and transport, mechanical properties (their evolution, subsequent fragmentation and cracking, fuel-cladding mechanical interaction), and compatibility with cladding and coolant (internal cladding corrosion, chemical interactions especially in case of severe accident). These are all addressed from both an experimental and a modelling perspective.
Besides the obvious need of adequate financial resources in order to address the research problems outlined in this SRA, as well as the necessary corollaries, four recommendations emerge that this document is intended to bring to the attention of stake-holders, particularly decision-makers:
R1: Data from materials property measurements after exposure to relevant conditions are the essential ingredient for robust design curves and rules. Plenty of data were produced in the past that are now de facto unusable; this is either because they are covered by confidentiality or because they were not properly archived. Correct data management to guarantee availability for future re-assessment is therefore essential and should be encouraged and fostered. In particular, financially supported policies to foster data sharing and encourage old data disclosure should be implemented.
R2: Some infrastructures are absolutely essential to enable the correct qualification of nuclear materials, not only irradiation facilities, but also suitable ‘hot’ cells where active materials can be safely handled and tested, nuclearized characterization techniques, loops and pools for compatibility experiments, etc. They are also crucial for education and training of young researchers and operators. These infrastructures are costly to build and maintain. Other research facilities are, on the other hand, more common and sometimes redundant. A rational and harmonised, pan-European management of infrastructures, based on joint programming, including trans-national infrastructure renewal planning and a scheme for facility sharing and exploitation, would be highly desirable and, at the end of the day, beneficial for all.
R3: International cooperation with non-EU countries where research on nuclear materials is pursued can be very valuable for Europe. Quite clearly, the goals of this cooperation are in the end the same as in the case of internal European cooperation, namely coordination of activities, sharing of data, and access to infrastructures. Currently, however, the instruments available in Europe for international cooperation are not sufficiently attractive to motivate significant cooperation with non-EU researchers. Efforts should be made to improve their attractiveness and ease of access. International organisations such as OECD.NEA, IAEA, but also Euratom and JRC for the connection with GIF, have here a crucial role.
R4: The nuclear materials research community in Europe is currently strongly integrated and engaged in thriving collaboration, in a bottom-up sense. This is in contrast with the inadequacy of the top-down instruments offered to make this integration efficient and functional. This SRA is largely the result of matching bottom-up research proposals with top-down strategies. The appropriate instrument to allow this community to deliver according to the SRA goals should provide the conditions to implement the agreed research agenda and to set up suitable E&T&M schemes that allow knowledge, data, and facility sharing. Since the financial support of Euratom will never be sufficient, earmarked funding from the MS dedicated to support integrated research on nuclear materials is crucial. In this sense, a co-fund instrument, such as a European Joint Programme, seems to be most suitable.JRC.G.I.4-Nuclear Reactor Safety and Emergency Preparednes
Observation of Orbitally Excited B_s Mesons
We report the first observation of two narrow resonances consistent with
states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar
collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the
Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed
as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+,
\bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1})
= 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let
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