282 research outputs found
Simulation of a method to directly image exoplanets around multiple stars systems
Direct imaging of extra-solar planets has now become a reality, especially
with the deployment and commissioning of the first generation of specialized
ground-based instruments such as the GPI, SPHERE, P1640 and SCExAO. These
systems will allow detection of planets 1e7 times fainter than their host star.
For space-based missions, such as EXCEDE, EXO-C, EXO-S, WFIRST-AFTA,
different teams have shown in laboratories contrasts reaching 1e-10 within a
few diffraction limits from the star using a combination of a coronagraph to
suppress light coming from the host star and a wavefront control system. These
demonstrations use a deformable mirror (DM) to remove residual starlight
(speckles) created by the imperfections of telescope. However, all these
current and future systems focus on detecting faint planets around a single
host star or unresolved binaries/multiples, while several targets or planet
candidates are located around nearby binary stars such as our neighbor star
Alpha Centauri.
Until now, it has been thought that removing the light of a companion star is
impossible with the current technology, excluding binary star systems from
target lists of direct imaging missions. Direct imaging around binaries or
multiples systems at a level of contrast allowing Earth-like planets detection
is challenging because the region of interest, where a dark zone is essential,
is contaminated by the light coming from the host star's companion. We propose
a method to simultaneously correct aberration sand diffraction of light coming
from the target star. This method works even if the companion star is outside
the control region of the DM (beyond its half-Nyquist frequency), by taking
advantage of aliasing effects.Comment: 8 pages, 13 figures, SPIE Astronomical Telescope and Instrumentation
conferenc
Síndrome hepatorrenal: Revisión de la literatura
El síndrome hepatorrenal (SHR) es una complicación frecuente y severa en pacientes con cirrosis hepática e hipertensión portal y se caracteriza por anormalidades circulatorias que llevan a vasoconstricción renal, generando insuficiencia renal funcional.Su fisiopatología ha sido estudiada y el pronóstico es reservado a menos que el paciente reciba trasplante hepático.El tratamiento medicamentoso con vasoconstrictores esplénicos es la esperanza futura de estos pacientes mientras acceden a trasplante hepático.El síndrome hepatorrenal (SHR) es una complicación frecuente y severa en pacientes con cirrosis hepática e hipertensión portal y se caracteriza por anormalidades circulatorias que llevan a vasoconstricción renal, generando insuficiencia renal funcional.Su fisiopatología ha sido estudiada y el pronóstico es reservado a menos que el paciente reciba trasplante hepático. El tratamiento medicamentoso con vasoconstrictores esplénicos es la esperanza futura de estos pacientesmientras acceden a trasplante hepático
Síndrome hepatorrenal: Revisión de la literatura
El síndrome hepatorrenal (SHR) es una complicación frecuente y severa en pacientes con cirrosis hepática e hipertensión portal y se caracteriza por anormalidades circulatorias que llevan a vasoconstricción renal, generando insuficiencia renal funcional.Su fisiopatología ha sido estudiada y el pronóstico es reservado a menos que el paciente reciba trasplante hepático.El tratamiento medicamentoso con vasoconstrictores esplénicos es la esperanza futura de estos pacientes mientras acceden a trasplante hepático.El síndrome hepatorrenal (SHR) es una complicación frecuente y severa en pacientes con cirrosis hepática e hipertensión portal y se caracteriza por anormalidades circulatorias que llevan a vasoconstricción renal, generando insuficiencia renal funcional.Su fisiopatología ha sido estudiada y el pronóstico es reservado a menos que el paciente reciba trasplante hepático. El tratamiento medicamentoso con vasoconstrictores esplénicos es la esperanza futura de estos pacientesmientras acceden a trasplante hepático
On the Concepts of Parallelism in Biomolecular Computing
In this paper we consider DNA and membrane computing, both as theoretical models and as problem solving devices. The basic motivation behind these models of natural computing is using parallelism to make hard problems tractable. In this paper we analyze the concept of parallelism. We will show that parallelism has very different meanings in these models.We introduce the terms ’or-parallelism’ and ’and-parallelism’ for these two basic types of parallelism
Preliminary evaluation of fish settlement on GuSi Type Collectors, Santa Marta, Colombian Caribbean [abstract of poster presentation]
Configurable Aperture Space Telescope
In December 2014, we were awarded Center Innovation Fund to evaluate an optical and mechanical concept for a novel implementation of a segmented telescope based on modular, interconnected small sats (satlets). The concept is called CAST, a Configurable Aperture Space Telescope. With a current TRL is 2 we will aim to reach TLR 3 in Sept 2015 by demonstrating a 2x2 mirror system to validate our optical model and error budget, provide straw man mechanical architecture and structural damping analyses, and derive future satlet-based observatory performance requirements. CAST provides an alternative access to visible and/or UV wavelength space telescope with 1-meter or larger aperture for NASA SMD Astrophysics and Planetary Science community after the retirement of HS
- …