1,423 research outputs found
Harvesting graphics power for MD simulations
We discuss an implementation of molecular dynamics (MD) simulations on a
graphic processing unit (GPU) in the NVIDIA CUDA language. We tested our code
on a modern GPU, the NVIDIA GeForce 8800 GTX. Results for two MD algorithms
suitable for short-ranged and long-ranged interactions, and a congruential
shift random number generator are presented. The performance of the GPU's is
compared to their main processor counterpart. We achieve speedups of up to 80,
40 and 150 fold, respectively. With newest generation of GPU's one can run
standard MD simulations at 10^7 flops/$.Comment: 12 pages, 5 figures. Submitted to Mol. Si
Somatic embryogenesis in explants of adult wild olive trees
In this investigation, somatic embryogenesis in explants of adult wild olive trees, using the protocol developed by Mazri et al. (2013, Sci. Hort. 159: 88-95), was induced. Four genotypes differring in the level of resistance to the fungal pathogen Verticillium dahliae were used: Ac18, StopVert and OutVert (symptomless resistant genotypes, JimĂ©nez-Fernández et al. 2015, Plant Pathology, in press) and Ac15 (susceptible genotype, JimĂ©nez-DĂaz, IAS-CSIC, CĂłrdoba, personal communication). Three types of explants from actively growing cultures were used: first pair of leaves, petioles and shoot apex. Firstly, all explants were cultured on a liquid induction medium with MS mineral elements at 0.5X and 30 ÎĽM TDZ-0.5 ÎĽM NAA, for 4 days at 80rpm. Afterwards, explants were transferred to basal MS with 0.5X macroelements, for 8 weeks. Finally, calli were cultured on expression ECO medium supplemented with 0.25 ÎĽM IBA, 0.5 ÎĽM 2ip and 0.44 ÎĽM BA, for several subcultures. Cultures were incubated under darkness at 25 degrees. Embryogenic calli were observed on shoot apex (StopVert) or leaf primordia (Ac18) explants.Universidad de Málaga. Campus de Excelencia Internacional AndalucĂa Tech
In situ Raman characterization of minerals and degradation processes in a variety of cultural and geological heritage sites
Wetest the capabilities of in situ Raman spectroscopy for non-destructive analysis of degradation processes in invaluable
masterpieces, as well as for the characterization of minerals and prehistoric rock-art in caves. To this
end, we have studied the mechanism of decay suffered by the 15th-century limestone sculptures that decorate
the retro-choir of Burgos Cathedral (N Spain). In situ Raman probe detected hydrated sulfate and nitrateminerals
on the sculptures, which are responsible for the decay of the original limestone. In addition, in situ Raman analyses
were performed on unique speleothems in El Soplao Cave (Cantabria, N Spain) and in the Gruta de las
Maravillas (Aracena, SWSpain). Unusual cavemineralswere detected in El Soplao Cave, such as hydromagnesite
(Mg5(CO3)4(OH)2·4H2O), as well as ferromanganese oxides in the black biogenic speleothems recently discovered
in this cavern. In the Gruta de las Maravillas, gypsum (CaSO4·2H2O) was identified for the first time, as
part of the oldest cave materials, so providing additional evidence of hypogenic mechanisms that occurred in
this cave during earlier stages of its formation. Finally, we present preliminary analyses of several cave paintings
in the renowned “Polychrome Hall” of Altamira Cave (Cantabria, N. Spain). Hematite (Fe2O3) is the most abundant
mineral phase, which provides the characteristic ochre-reddish color to the Altamira bison and deer paintings.
Thus, portable Raman spectroscopy is demonstrated to be an analytical technique compatible with
preserving our cultural and natural heritage, since the analysis does not require physical contact between the
Raman head and the analyzed items
Single polarized Tm3+ laser in Zn-diffused LiNbO3 channel waveguides
Copyright (2005) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 86 (2005): 161119 and may be found at http://apl.aip.org
Social campaigns to encourage responsible fashion consumption: qualitative study with university students
A fruitful line of research on responsible consumption has recently emerged due to a concern for and interest in environmental issues and the growing resource depletion, providing an opportunity for communications to influence human behavior toward environmental protection. This paper shows the design, implementation, and impact assessment of two social campaigns aimed to inform the public of the effects of an overconsumption of clothing and encourage responsible consumption. We designed a non-experimental, descriptive, qualitative study based on 30 semi-structured interviews with university students in Bogotá, Colombia, from variables such as campaigns’ message, behavioral intentions, and relationship with the social and environmental context. The results show the students’ unawareness of overconsumption but suggest a positive impact on their intentions to increase responsible apparel consumption. This study contributes to empirical knowledge of better alternatives for effective messages that favor responsible consumption.En los Ăşltimos años se ha desarrollado una fructĂfera lĂnea de investigaciĂłn en consumo responsable debido a la preocupaciĂłn y el interĂ©s por el problema ambiental y el creciente deterioro de los recursos naturales, lo que representa un campo de trabajo para la comunicaciĂłn en su posibilidad de influir en el comportamiento humano a favor del cuidado y protecciĂłn del ambiente. Este trabajo presenta el diseño, desarrollo y evaluaciĂłn de impacto de dos campañas sociales orientadas a informar sobre los efectos del consumo desmedido de prendas de vestir y fortalecer el consumo responsable de este tipo de productos. Se diseñó un estudio no experimental, descriptivo y de carácter cualitativo, basado en 30 entrevistas semiestructuradas a estudiantes universitarios en Bogotá (Colombia), a partir de variables como el mensaje de las campañas, las intenciones conductuales y la relaciĂłn con el contexto social y ambiental. Los hallazgos evidencian desconocimiento acerca del problema derivado del consumo excesivo de prendas de vestir, aunque sugieren un impacto positivo respecto a las posibles intenciones comportamentales a favor del consumo responsable de ropa. Esta investigaciĂłn aporta al conocimiento empĂrico sobre alternativas en la construcciĂłn de mensajes efectivos para coadyuvar al consumo responsable
Red, green, and blue simultaneous generation in aperiodically poled Zn-diffused LiNbO3:Er3+/Yb3+ nonlinear channel waveguides
Copyright (2003) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 83.15 (2003): 2991-2993 and may be found at http://apl.aip.org
Near-infrared electroluminescence beyond 940 nm in Pt(N^C^N)X complexes: influencing aggregation with the ancillary ligand X
We present a study of aggregate excited states formed by complexes of the type Pt(N^C^N)X, where N^C^N represents a tridentate cyclometallating ligand, and X = SCN or I. These materials display near-infrared (NIR) photoluminescence in film and electroluminescence in NIR OLEDs with λmaxEL = 720–944 nm. We demonstrate that the use of X = SCN or I modulates aggregate formation compared to the parent complexes where X = Cl. While the identity of the monodentate ligand affects the energy of Pt–Pt excimers in solution in only a subtle way, it strongly influences aggregation in film. Detailed calculations on aggregates of different sizes support the experimental conclusions from steady-state and time-resolved luminescence studies at variable temperatures. The use of X = I appears to limit aggregation to the formation of dimers, while X = SCN promotes the formation of larger aggregates, such as tetramers and pentamers, leading in turn to NIR photo- and electroluminescence > 850 nm. A possible explanation for the contrasting influence of the monodentate ligands is the lesser steric hindrance associated with the SCN group compared to the bulkier I ligand. By exploiting the propensity of the SCN complexes to form extended aggregates, we have prepared an NIR-emitting OLED that shows very long wavelength electroluminescence, with λmaxEL = 944 nm and a maximum EQE = 0.3 ± 0.1%. Such data appear to be unprecedented for a device relying on a Pt(II) complex aggregate as the emitter
Optimal Power Flow in Direct Current Networks Using the Antlion Optimizer
This document presents a solution method for optimal power flow (OPF) problem in direct current (DC) networks by implementing a master-slave optimization methodology that combines an antlion optimizer (ALO) and a power flow approach based on successive approximation (SA ). In the master stage, the ALO determines the optimal amount of power to be delivered by all the distributed generators (DGs) in order to minimize the total power losses in the distribution lines of the DC network. In slave stage, the power flow problem is solved considering constant power loads and power outputs of DGs as constants. To validate the effectiveness and robustness of the proposed model, two additional comparative methods were implemented: particle swarm optimization (PSO) and black hole optimization (BHO). Two distribution test feeders (21 and 69 nodes) were simulated under different scenarios of distributed power generation. The simulations, conducted in MATLAB 2018, show that the proposed method (ALO) presents a better balance between power loss minimization and computational time required to find the optimal solution regardless of the size of the DC network
Abundance and diversity of Heteropteran species in portuguese olive groves
The olive tree canopy is a habitat for phytophagous and predaceous Heteropteran specimens
whose biodiversity is important to be characterized. The aim of this world was to study the abundance
and diversity of Heteropteran specimens in Portuguese olive groves with different plant
protection systems (conventional. integrated protection and organic farming groves). Therefore,
data were obtained in olive groves located in the main olive Portuguese regions (Alto Alentejo and Trás-os-Montes). Sampling occurred in 1999, 2000, 2002 and 2003 and samples were obtained
through the beating technique, on a weekly or fortnight basis from March to November of each
year. The captured heteropteran specimens were identified to family level and, when possible, to
genera or species level. Experimental results showed that specimens belonged to six families that
were, for order of importance: Anthocoridae, Miridae. Lygaeidae, Tingidae, Penlalomidae and
Nabidae. Beneficial predaceous specimens like AntiJocoris sp. and Deraeocoris lutenscens
(Schilling, 1837) were the most abundant of the Anthocoridae and Miridae families, respectively.
These families were more abundant from the beginning to the middle of June which coincided with
the antophagou5 larval stage of the olive moth, Prays oleae (Bernard)
Abundance and diversity of potential vectors of Xylella fastidiosa in four different wine regions of Portugal
Xylella fastidiosa, is a phytopathogenic bacterium, responsible for serious diseases in important
crops, such as Pierce’s Disease in grapevines. The recent detection of this bacterium in Portugal
is worrying, since this bacterium can spread rapidly via xylem-sap feeder insects, mainly belonging
to Hemiptera Cicadomorpha. In this context, the goal of this work was to detect the abundance and
diversity of possible vectors of X. fastidiosa in vineyards from different wine regions of Portugal. For
that, in 2018, 21 vineyards with ground cover and from four different wine regions of Portugal (i.e.,
“Trás-os-Montes”, “Vinho Verde”, “Bairrada”, and “Peninsula de Setúbal”) were sampled for adults of
Auchenorrhyncha, during three distinct periods (beginning of July, mid September and mid October).
Sampling was performed in the ground and in the aerial part of the vines. In each sampling date,
10 samples of 10 sweepings were collected on the ground in each vineyard. On the aerial part of
the vines, 10 samples of 50 sweepings were collected in 3 lines of the vineyard. A total of 3543
Cicadomorpha were collected on the 3 sampling dates, being the highest abundance observed in
the mid September. The “Trás-os-Montes” and “Bairrada” regions, in general, presented the highest
abundance of insects of this infraorder, but it was in “Vinho Verde” region that there was a highest
abundance of potential vectors: Philaenus, Neophilaenus and Cicadelli viridis.Work funded by the project H2020-SFS-2016-3. RIA, contrato 727987 “XF-ACTORS: Xylella
fastidiosa Active Containment Through a multidisciplinary-Oriented Research Strategy”.info:eu-repo/semantics/publishedVersio
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