Astronomical Site Ranking Based on Tropospheric Wind Statistics

We present comprehensive and reliable statistics of high altitude wind speeds and the tropospheric flows at the location of five important astronomical observatories. Statistical analysis exclusively of high altitude winds point to La Palma as the most suitable site for adaptive optics, with a mean value of 22.13 m/s at the 200 mbar pressure level. La Silla is at the bottom of the ranking, with the largest average value 200 mbar wind speed(33.35 m/s). We have found a clear annual periodicity of high altitude winds for the five sites in study. We have also explored the connection of high to low altitude atmospheric winds as a first approach of the linear relationship between the average velocity of the turbulence and high altitude winds (Sarazin & Tokovinin 2001). We may conclude that high and low altitude winds show good linear relationships at the five selected sites. The highest correlation coefficients correspond to Paranal and San Pedro Martir, while La Palma and La Silla show similar high to low altitude wind connection. Mauna Kea shows the smallest degree of correlation, which suggests a weaker linear relationship. Our results support the idea of high altitude winds as a parameter for rank astronomical sites in terms of their suitability for adaptive optics, although we have no evidence for adopting the same linear coefficient at different sites. The final value of this linear coefficient at a particular site could drastically change the interpretation of high altitude wind speeds as a direct parameter for site characterization.Comment: 18 pages, 5 figures. Accepted in MNRA

Extended Parental Care in the Freshwater Shrimp Genus Dugastella Bouvier, 1912 (Decapoda, Atyidae, Paratyinae)

5 páginas, 1 figura.Parental care and extended parental care are known behaviours in decapod crustaceans (see Thiel, 2000, 2003). While parental care before hatching, which involves incubation of the eggs (carrying, cleaning, and aeration) by females, is a common behaviour in the majority of decapod taxa (with the exception of Dendrobranchiata), extended parental care is a rare behaviour in decapods, restricted only to some species of brachyuran crabs (Diesel, 1989, 1992, 1997; Diesel & Horst, 1995; Ng & Tan, 1995), hermit crabs (Hazlett, 1983; López Greco et al., 2004; Calado et al., 2006), astacid crayfishes (Johnston & Fiegel, 1997; Vogt & Tolley, 2004), and caridean shrimps (Duffy, 1996). In the majority of these cases, the parental female presents different types of parental activity towards the offspring after hatching, like habitat control, elimination of predators, or sharing meals. Also, there are some cases in which larvae develop transient structures that allow them to remain fixed to the pleopods of the female abdomen, like in astacids (see Vogt & Tolley, 2004) and several species of the genus Sclerocrangon Sars, 1883 (see Makarov, 1968; Lacoursière-Roussel & Sainte-Marie, 2009). However, the most infrequent cases of extended parental care in decapods are those where females carry their juvenile offspring under their abdomen after the hatched larvae develop there (cf. abdominal brood pouches, or incubation chamber). These cases have only been reported in one species of Brachyura, Tunicotheres moseri (Rathbun, 1918) (see Bolaños et al., 2004), and one caridean, the kangaroo shrimp Dugastella valentina (Ferrer Galdiano, 1924) (see Cuesta et al., 2006). Taking into account this last case, and considering that there are only two species in the genus Dugastella Bouvier, 1912, the objective of the present study was to corroborate whether the other species, D. marocana Bouvier, 1912, also presents the same behaviour. These two species have a a restricted distribution, D. valentina occurs in the Gulf of Valencia (southern Europe) and D. marocana is found in some localities of Morocco (northwestern Africa).Collections in Morocco by JEGM and JEGR were possible thanks to fundings provided by “CSIC Proyectos Intramurales Especiales” 2006 3 01 238 to JAC.Peer reviewe

Taxonomic study of the Pagurus forbesii "complex" (Crustacea: Decapoda: Paguridae). Description of pagurus pseudosculptimanus sp. nov. from alborán sea (Southern Spain, Western Mediterranean Sea)

Study of hermit crabs from Alboran Sea has allowed recognition of two different morphological forms under what had been understood as Pagurus forbesii. Based on morphological observations with various species of Pagurus, and molecular studies, a new species is described as P. pseudosculptimanus. An overview of species of Pagurus from the eastern Atlantic and Mediterranean Sea is provided. © Copyright 2014 Magnolia Press.This work was supported by the Junta de Andalucía RNM-0141 Research Group.Peer Reviewe

Coupling of morphology to surface transport in ion-beam irradiated surfaces. I. Oblique incidence

We propose and study a continuum model for the dynamics of amorphizable surfaces undergoing ion-beam sputtering (IBS) at intermediate energies and oblique incidence. After considering the current limitations of more standard descriptions in which a single evolution equation is posed for the surface height, we overcome (some of) them by explicitly formulating the dynamics of the species that transport along the surface, and by coupling it to that of the surface height proper. In this we follow recent proposals inspired by ``hydrodynamic'' descriptions of pattern formation in aeolian sand dunes and ion-sputtered systems. From this enlarged model, and by exploiting the time-scale separation among various dynamical processes in the system, we derive a single height equation in which coefficients can be related to experimental parameters. This equation generalizes those obtained by previous continuum models and is able to account for many experimental features of pattern formation by IBS at oblique incidence, such as the evolution of the irradiation-induced amorphous layer, transverse ripple motion with non-uniform velocity, ripple coarsening, onset of kinetic roughening and other. Additionally, the dynamics of the full two-field model is compared with that of the effective interface equation.Comment: 23 pages, 14 figures. Movies of figures 6, 7, and 8 available at http://gisc.uc3m.es/~javier/Movies

Weyl type theorems for restrictions of bounded linear operators

In this paper we give sufficient conditions for which Weyl’s theorems for a bounded linear operator T, acting on a Banach space X, can be reduced to the study of Weyl’s theorems for some restriction of T.peerReviewe

Weyl type theorems for restrictions of bounded linear operators

In this paper we give sufficient conditions for which Weyl’s theorems for a bounded linear operator T, acting on a Banach space X, can be reduced to the study of Weyl’s theorems for some restriction of T.peerReviewe

Massive Parallel Current Power Amplifier Concept for Power Hardware in the Loop Applications

The development of the smartgrid increases the complexity of the current electric grid. To verify and validate the operation of the systems involved in it, Power Hardware-In-theLoop (PHIL) technique allows to test the complete system in an exhaustive way. But the reduced bandwidth of the overall test system can cause inaccuracies and instabilities, which can be harmful for the Hardware Under Test (HUT) or the people who are performing the test. To increase PHIL performance and tackle these problems, this paper proposes a new concept of high bandwidth current amplifier. It is based on a topology of massive parallel interleaved buck-boost converter, which distribute in an equal manner the total current in all the branches. This current reduction allows to use transistors with better switching behaviour, which increase the bandwidth of the converter. Furthermore, a Discontinuous Conduction Mode (DCM) is used, obtaining the nominal output current in only one switching cycle. Description of the concept and the design parameters are provided. Finally, the behaviour of the proposed Power Amplifier (PA) at high frequency setpoint currents is shown in a Matlab/Simulink simulation. © 2022, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved

Coulomb explosion sputtering of selectively oxidized Si

We have studied multiply charged Arq+ ion induced potential sputtering of a unique system comprising of coexisting Silicon and Silicon oxide surfaces. Such surfaces are produced by oblique angle oxygen ion bombardment on Si(100), where ripple structures are formed and one side of each ripple gets more oxidized. It is observed that higher the potential energy of Arq+ ion, higher the sputtering yield of the non conducting (oxide) side of the ripple as compared to the semiconducting side. The results are explained in terms of Coulomb explosion model where potential sputtering depends on the conductivity of the ion impact sites.Comment: 9 pages and 3 figure