Asteroid taxonomic signatures from photometric phase curves

We explore the correlation between an asteroid's taxonomy and photometric phase curve using the H, G12 photometric phase function, with the shape of the phase function described by the single parameter G12. We explore the usability of G12 in taxonomic classification for individual objects, asteroid families, and dynamical groups. We conclude that the mean values of G12 for the considered taxonomic complexes are statistically different, and also discuss the overall shape of the G12 distribution for each taxonomic complex. Based on the values of G12 for about half a million asteroids, we compute the probabilities of C, S, and X complex membership for each asteroid. For an individual asteroid, these probabilities are rather evenly distributed over all of the complexes, thus preventing meaningful classification. We then present and discuss the G12 distributions for asteroid families, and predict the taxonomic complex preponderance for asteroid families given the distribution of G12 in each family. For certain asteroid families, the probabilistic prediction of taxonomic complex preponderance can clearly be made. The Nysa-Polana family shows two distinct regions in the proper element space with different G12 values dominating in each region. We conclude that the G12-based probabilistic distribution of taxonomic complexes through the main belt agrees with the general view of C complex asteroid proportion increasing towards the outer belt. We conclude that the G12 photometric parameter cannot be used in determining taxonomic complex for individual asteroids, but it can be utilized in the statistical treatment of asteroid families and different regions of the main asteroid belt.Comment: submitted to Icaru

The Use of Pedicled Perforator Flaps in Chest Reconstruction: A Systematic Review of Outcomes and Reliability

BACKGROUND: In recent years, pedicled perforator flaps have revolutionized plastic surgery by reducing donor site morbidity and ensuring larger and deeper reconstructions with local pedicled cutaneous flaps. The aim of the study was to make a systematic review of perforator pedicled propeller flaps (PPPFs) in chest reconstruction. METHODS: Pubmed and Cochrane databases were searched from 1989 to October 2016 for articles describing the use of PPPFs in chest reconstruction. The preferred reporting items for systematic reviews and meta analyses statement was used in the selection process. The review was registered on international prospective register of systematic reviews. Furthermore, operative technique, indications and complications were searched. RESULTS: Twenty-four articles were selected (174 patients and 182 flaps). Oncological surgery was the first etiology (34.5%), followed by infections (11.5%), chest keloid scars (6.23%), malformations (4.6%), burns (3.4%), chronic ulcers (2.3%), Verneuil disease (1.8%), and acute wounds (1.8%). The arc of rotation was between 90° and 120° in 24.2%. The mean surface of flaps was 127.45 ± 123.11 cm. Dissection was subfascial in 78.5% of the cases. Complications were found in 9.9% of patients and included mainly wound dehiscence (4.4%) and hematoma/seroma (2.2%). One case of total necrosis (0.5%) and 2 cases of partial necrosis (1.1%) were found. CONCLUSIONS: The possibility of numerous pedicles makes it possible for PPPFs to offset most areas of wall chest defects. Furthermore, this surgical technique is reliable and reproducible, with lower donor site morbidity than that in the case of muscular flaps, which are classically used in this location

A Peculiar Family of Jupiter Trojans: the Eurybates

The Eurybates family is a compact core inside the Menelaus clan, located in the L4 swarm of Jupiter Trojans. Fornasier et al. (2007) found that this family exhibits a peculiar abundance of spectrally flat objects, similar to Chiron-like Centaurs and C-type main belt asteroids. On the basis of the visible spectra available in literature, Eurybates family's members seemed to be good candidates for having on their surfaces water/water ice or aqueous altered materials. To improve our knowledge of the surface composition of this peculiar family, we carried out an observational campaign at the Telescopio Nazionale Galileo (TNG), obtaining near-infrared spectra of 7 members. Our data show a surprisingly absence of any spectral feature referable to the presence of water, ices or aqueous altered materials on the surface of the observed objects. Models of the surface composition are attempted, evidencing that amorphous carbon seems to dominate the surface composition of the observed bodies and some amount of silicates (olivine) could be present.Comment: 23 pages, 2 figures, paper accepted for publication in Icaru

Color Confirmation of Asteroid Families

We discuss optical colors of 10,592 asteroids with known orbits selected from a sample of 58,000 moving objects observed by the Sloan Digital Sky Survey (SDSS). This is more than ten times larger sample that includes both orbital parameters and multi-band photometric measurements than previously available. We confirm that asteroid dynamical families, defined as clusters in orbital parameter space, also strongly segregate in color space. In particular, we demonstrate that the three major asteroid families (Eos, Koronis, and Themis), together with the Vesta family, represent four main asteroid color types. Their distinctive optical colors indicate that the variations in chemical composition within a family are much smaller than the compositional differences between families, and strongly support earlier suggestions that asteroids belonging to a particular family have a common origin. We estimate that over 90% of asteroids belong to families.Comment: 18 pages, color figures, accepted by A

Magnetization reversal processes in epitaxial Fe/GaAs(001) films

Copyright © 1994 American Institute of PhysicsIn this article we present the results of a detailed study of the switching behavior observed in epitaxial single Fe films of thickness between 30 and 450 Å, and a wedge shaped Fe film with a thickness range of 10–60 Å grown on GaAs (001). These films have cubic and uniaxial anisotropies which change with film thickness. For the fixed thickness films the values of the anisotropy constants were accurately determined by Brillouin light scattering (BLS) measurements together with polar magneto‐optic Kerr effect (MOKE) measurements that gave the value of the magnetization. The switching behavior of these samples was observed with in‐plane MOKE magnetometry as a function of the angle between the applied field and the in‐plane crystallographic axes. Measurements of the component of magnetization perpendicular to the applied field allow a precise determination of the relative orientation of the hard and easy in‐plane anisotropy axes. This can be used to accurately determine the ratio of uniaxial to cubic anisotropy constants, when this ratio is less than one. The ratios obtained from MOKE agree well with those obtained from BLS. Minimum energy calculations predict that the reversal process should proceed by a continuous rotation of the magnetization vector with either one or two irreversible jumps, depending on the applied field orientation and the nature of the anisotropy of the film. The calculations provide a good qualitative description of the observed reversal process, although the magnetic microstructure influences the exact values of the switching fields

Exchange Anisotropy in Epitaxial and Polycrystalline NiO/NiFe Bilayers

(001) oriented NiO/NiFe bilayers were grown on single crystal MgO (001) substrates by ion beam sputtering in order to determine the effect that the crystalline orientation of the NiO antiferromagnetic layer has on the magnetization curve of the NiFe ferromagnetic layer. Simple models predict no exchange anisotropy for the (001)-oriented surface, which in its bulk termination is magnetically compensated. Nonetheless exchange anisotropy is present in the epitaxial films, although it is approximately half as large as in polycrystalline films that were grown simultaneously. Experiments show that differences in exchange field and coercivity between polycrystalline and epitaxial NiFe/NiO bilayers couples arise due to variations in induced surface anisotropy and not from differences in the degree of compensation of the terminating NiO plane. Implications of these observations for models of induced exchange anisotropy in NiO/NiFe bilayer couples will be discussed.Comment: 23 pages in RevTex format, submitted to Phys Rev B

Readiness for implementing innovations in banking in advanced and emerging economies

The development of innovation requires special knowledge from various management areas, as well as technological and intellectual support from the state. The study aims to assess the country’s readiness to introduce innovative banking technologies. The methodological tools used for the study include bibliographic analysis, fuzzy logic, factor analysis, and the Brown-Mayer model. The period under consideration is 2004-2018. The paper focuses on two groups of countries: advanced economies (Germany, France, Czech Republic, and Spain), emerging markets and developing economies (Ukraine, Poland, Turkey, Croatia, Romania). The results of bibliometric analysis obtained with VOSViewerv.1.6.10 toolkit prove that the most significant factors affecting the country’s readiness to implement banking innovations are intensive economic growth, development of information and communication technologies in society, and financial strength of the banking system. The assessment results show a gradual improvement of technological and economic conditions that are necessary for the intensification of innovation processes in banking in the countries. France, Germany, Turkey, and Poland are among the leading countries with the best conditions for the development of banking innovations, while Ukraine, Croatia, and Romania have the least favorable conditions among analyzed countries. The results of this empirical study can be used to formulate a strategic plan for the development of a country’s banking system

The Main Belt Comets and ice in the Solar System

We review the evidence for buried ice in the asteroid belt; specifically the questions around the so-called Main Belt Comets (MBCs). We summarise the evidence for water throughout the Solar System, and describe the various methods for detecting it, including remote sensing from ultraviolet to radio wavelengths. We review progress in the first decade of study of MBCs, including observations, modelling of ice survival, and discussion on their origins. We then look at which methods will likely be most effective for further progress, including the key challenge of direct detection of (escaping) water in these bodies