6,463 research outputs found
A Study on the Impact of Climate Variability/Change on Water Resources in the Philippines
This paper presents an effort toward a better understanding of the potential impact of climate variability and change on the hydrology and water resources in the Philippines. Impacts of extreme events such as droughts are discussed. A preliminary study on the variability of inflow in relation to rainfall at the major dams in Luzon and the natural water reservoir of Lake Lanao is presented. Areas for future study are also mentioned.watershed
A Study on the Impact of Climate Variability/Change on Water Resources in the Philippines
This paper presents an effort toward a better understanding of the potential impact of climate variability and change on the hydrology and water resources in the Philippines. Impacts of extreme events such as droughts are discussed. A preliminary study on the variability of inflow in relation to rainfall at the major dams in Luzon and the natural water reservoir of Lake Lanao is presented. Areas for future study are also mentioned.watershed
Spontaneous chirality via long-range electrostatic forces
We consider a model for periodic patterns of charges constrained over a
cylindrical surface. In particular we focus on patterns of chiral helices,
achiral rings or vertical lamellae, with the constraint of global
electroneutrality. We study the dependence of the patterns' size and pitch
angle on the radius of the cylinder and salt concentration. We obtain a phase
diagram by using numerical and analytic techniques. For pure Coulomb
interactions, we find a ring phase for small radii and a chiral helical phase
for large radii. At a critical salt concentration, the characteristic domain
size diverges, resulting in macroscopic phase segregation of the components and
restoring chiral symmetry. We discuss possible consequences and generalizations
of our model.Comment: Revtex, 4 pages, 4 figure
Charged Particles on Surfaces: Coexistence of Dilute Phases and Periodic Structures on Membranes
We consider a mixture of one neutral and two oppositely charged types of
molecules confined to a surface. Using analytical techniques and molecular
dynamics simulations, we construct the phase diagram of the system and exhibit
the coexistence between a patterned solid phase and a charge-dilute phase. The
patterns in the solid phase arise from competition between short-range
immiscibility and long-range electrostatic attractions between the charged
species. The coexistence between phases leads to observations of stable
patterned domains immersed in a neutral matrix background.Comment: 5 pages, 3 figure
Monosized dripping mode of axisymmetric flow focusing
We identify and analyze the perfectly regular dripping mode of flow focusing. This mode occurs within narrow
intervals of injected flow rates and applied pressure drops and leads to homogeneous-size droplets with diameters
similar to or smaller than that of the discharge orifice. The balance between the local acceleration of the fluid
particle and the applied pressure drop yields the scaling law for the droplet diameter. This scaling law is validated
experimentally with excellent accord.Ministerio de EconomÃa, Industria y Competitividad DPI2013-46485Gobierno de Extremadura GR1004
La Garza Real en España. I. Población reproductora (1950-2000)
En este trabajo se analiza la evolución de la población reproductora de
Garza Real, Ardea cinerea, en España durante el perÃodo 1950-2000. El territorio
español se ha dividido en siete grandes zonas: Norte, Levante, y las cuencas de los
cinco grandes rÃos (Guadalquivir, Guadiana, Tajo, Duero y Ebro). Los datos sobre
colonias y número de parejas nidificantes fueron obtenidos a partir de prospecciones
de los autores, de citas bibliográficas y de comunicaciones de organismos y personas
conocedoras de las colonias. Es probable que ya antes de 1950 hubiera colonias
ocupadas, pero se carece de datos publicados sobre ellas. En 1950 pudo haber
168 parejas reproductoras en 4 colonias, mientras que en 2000 hubo 4790 parejas
en 75 colonias. Las subpoblaciones de garza real asentadas de las cuencas del
Duero y Tajo parecen estar próximas al equilibrio numérico, mientras que las del
Ebro, Guadalquivir y Levante han aumentado notablemente su tamaño en la década
1990-2000. La cuenca del Guadiana contenÃa relativamente pocas parejas en el
perÃodo de estudio y en el Norte de España la población reproductora de la garza
real es aún poco significativa
An Optimisation Algorithm to Establish the Location of Stations of a Mixed Fleet Biking System: An Application to the City of Lisbon
AbstractThis paper presents the design and deployment of a bike-sharing system developed for Lisbon. The design of this new service is performed through an heuristic, encompassing a Mixed Integer Linear Program (MILP), that simultaneously optimise the location of shared biking stations, the fleet dimension and measuring the bicycle relocation activities required in a regular operation day. The results obtained for the several tested scenarios provided better insights into knowing how to improve the design and operation of these systems
A Proposal for a Modified Moller-Plesset Perturbation Theory
A modified version of the Moller-Plesset approach for obtaining the
correlation energy associated to a Hartree-Fock ground state is proposed. The
method is tested in a model of interacting fermions that allows for an exact
solution. Using up to third order terms improved results are obtained, even
more accurate in the limit of loosely bound particles. This result suggests the
possible convenience of the scheme for the study of chemical bound problems.Comment: 10 pages, 1 figur
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