1,568 research outputs found
Front propagation in an exclusion one-dimensional reactive dynamics
We consider an exclusion process representing a reactive dynamics of a pulled
front on the integer lattice, describing the dynamics of first class
particles moving as a simple symmetric exclusion process, and static second
class particles. When an particle jumps to a site with a particle,
their position is intechanged and the particle becomes an one.
Initially, there is an arbitrary configuration of particles at sites , and particles only at sites , with a product Bernoulli law
of parameter . We prove a law of large numbers and a central
limit theorem for the front defined by the right-most visited site of the
particles at time . These results corroborate Monte-Carlo simulations
performed in a similar context. We also prove that the law of the particles
as seen from the front converges to a unique invariant measure. The proofs use
regeneration times: we present a direct way to define them within this context.Comment: 19 page
Diet of Cypraea caputdraconis (Mollusca: Gastropoda) As It Relates to Food Availability in Easter Island
Diet and food preferences of Easter Island's endemic cowrie,
Cypraea caputdraconis (Melvill), are reported. Gut content analyses of specimens
from different rocky intertidal localities around the island revealed that C.
caputdraconis is primarily an herbivore. Algae composed > 90% of the cowrie's
diet in all cases. Five algal genera, Cladophora, Sphacelaria, Ceramium,
Galaxaura, and Pterocladia, were the most frequent and abundant items in the
diet of C. caputdraconis. The feeding habits of C. caputdraconis are most similar
to those of C. caputserpentis L. from Hawaii in that both have clearly
herbivorous diets. Both species share the R-l type of taenioglossan radula, which
also supports their close phylogenetic relationship. Indo-West Pacific populations
of C. caputserpentis have been suggested as ancestral to C. caputdraconis
from Easter Island
Annotated checklist of marine fishes from the Sanctuary of Bahía Chamela, Mexico with occurrence and biogeographic data.
An annotated checklist of marine fishes of the Sanctuary of Islands and Islets of Bahía Chamela in the central Mexican Pacific is presented. Records of fish species were obtained by different methods including visual census, sampling with anesthetics, fisherman-nets, and trawling with a biological dredge. Additional records were obtained from natural history collections and publications. The list comprises 196 species in 64 families and 141 genera. The Carangidae is the most speciose family with 11 species, followed by the Labridae with 10 and the Pomacentridae with nine. Fourteen species are endemic in Mexican Pacific waters, but none is restricted to Bahía Chamela. The most dominant species recorded during underwater surveys were Epinephelus labriformis, Stegastes flavilatus, and Halichoeres dispilus. Most species are of tropical affinities distributed throughout the tropical eastern Pacific (123), eastern Pacific (23), and Mexican Pacific (14). Other species are known from the eastern and Indo-Pacific regions (18), eastern Pacific and western Atlantic oceans (2), and some are circumtropical (9). A new record of the Gulf Brotula Ogilbia ventralis is provided for the Bahía Chamela and its geographical distribution is extended to Mexican central Pacific
Rate coefficient for the reaction of Cl atoms with cis-3-hexene at 296 ± 2 K
The rate coefficient of the cis-3-hexene + Cl atoms reaction at 296 ± 2 K and 750 ± 10 Torr was determined using the relative rate technique. The reaction was investigated using an 80 L Teflon reaction bag and a gas chromatograph coupled with flame-ionization detection. Chlorine atoms were produced by the photolysis of trichloroacetyl chloride. No previous experimental data was available in the literature, to the best of our knowledge. The mean second-order rate coefficient value found was (4.13 ± 0.51) × 10-10 cm3 molecule-1 s-1. The experimental value agrees with the rate coefficient estimated by structure-reactivity analysis, 4.27 × 10-10 cm3 molecule-1 s-1. Moreover, both addition and hydrogen abstraction channels contribute to the global kinetics, with branching ratios 70:30. Effective lifetime with respect to Cl atoms is predicted as 67.2 hours; however, the cis-3-hexene + Cl channel is suggested to be non-negligible at atmospheric conditions. Other atmospheric implications are discussed.Fil: Barbosa, Thaís S.. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Barrera, Javier Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Jara Toro, Rafael Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Bauerfeldt, Glauco F.. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Arbilla, Graciela. Universidade Federal do Rio de Janeiro; BrasilFil: Lane, Silvia Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin
Vulnerability curves for masonry buildings affected by hyperconcentrated flows as natural disaster risk management tools for the quantification of material damage
The damage assessment caused by floods, earthquakes, hurricanes among others phenomenons in the world are analyzed with methodologies such as "Vulnerability curves". In Peru, disasters caused by hyperconcentrated flows are alarming due to a climatic variability such as the "El Nio Costero"phenomenon. Therefore, this research has developed vulnerability curves for 1 and 2-story confined masonry buildings in Urb. San Idelfonso, Ica - Peru; linking the variables: flow depth, associated with the event produced by heavy rains at the top of the "Quebrada Cansas"caused by the "El Nio Costero"phenomenon in 2017, and the percentage of the damage based on the methodology of the United States Army Corps of Engineers (USACE), whose formula is the repair value and total building value. The monetary amounts and items of the buildings are obtained from the RM 415-2017-VIVIENDA of the Ministry of Housing, Construction and Sanitation of Peru. The process consisted of hydrological modeling in HEC-HMS, hydraulic modeling in FLO-2D, damage percentage estimate and vulnerability curves production. Finally, the vulnerability curves for hyperconcentrated flows were contrasted with similar studies regarding curves for flooding and debris flow. The results of the investigation showed that the "El Nio Costero"phenomenon in 2017 had an economic impact of at least 1.3 million soles in Urb. San Idelfonso. In addition, at least 24 buildings had a complete damage and 21 buildings an extensive damage
Pronóstico con interacción de variables categóricas
Departament de Psicologia Evolutiva, Social i Metodologia. Assignatura: PS104
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