Effects of finite sizes of atomic nuclei on shear modulus and torsional oscillations in neutron stars

The shear modulus of neutron star matter is one of the important properties for determining torsional oscillations in neutron stars. We take into account the effects of finite sizes of spherical nuclei on the shear modulus and examine the frequencies of crustal torsional oscillations. The shear modulus decreases owing to the finite-size effect, which in turn decreases the frequencies of torsional oscillations. In particular, the finite-size effect becomes more crucial for oscillations with a larger azimuthal quantum number and for neutron star models with a weaker density dependence of nuclear symmetry energy. In practice, when one identifies the quasi-periodic oscillations from a neutron star, where the magnetic effect is negligible, with crustal torsional oscillations, the finite-size effect can be more significant at frequencies higher than $\sim 100$ Hz.Comment: Accepted for publication in MNRA

Realistic three-generation models from SO(32) heterotic string theory

We search for realistic supersymmetric standard-like models from SO(32) heterotic string theory on factorizable tori with multiple magnetic fluxes. Three chiral ganerations of quarks and leptons are derived from the adjoint and vector representations of SO(12) gauge groups embedded in SO(32) adjoint representation. Massless spectra of our models also include Higgs fields, which have desired Yukawa couplings to quarks and leptons at the tree-level.Comment: 29 pages, Typos corrected, references added, and Sec. 3.3 is adde

Gauge coupling unification in SO(32) heterotic string theory with magnetic fluxes

We study $SO(32)$ heterotic string theory on torus with magnetic fluxes. Non-vanishing fluxes can lead to non-universal gauge kinetic functions for $SU(3) \times SU(2) \times U(1)_Y$ which is the important features of $SO(32)$ heterotic string theory in contrast to the $E_8\times E_8$ theory. It is found that the experimental values of gauge couplings are realized with ${\cal O}(1)$ values of moduli fields based on the realistic models with the $SU(3) \times SU(2) \times U(1)_Y$ gauge symmetry and three chiral generations of quarks and leptons without chiral exotics.Comment: 20 pages, 9 figure

A autodeterminação pela educação : direito indígena à educação e à identidade

Monografia (graduação)—Universidade de Brasília, Faculdade de Direito, 2014.Em 1500, os Europeus chegaram ao Brasil e acharam uma ampla diversidade de povos. Além de formas físicas de violência, foram utilizadas formas simbólicas. E estas foram, muitas vezes, acompanhadas por um projeto educacional civilizatório que não respeitou as particularidades desses povos. O último e recente paradigma educacional escolar, um tipo emancipatório, visa dar autonomia aos indígenas. Quando se consideram as fronteiras étnicas como fronteiras sinuosas, podemos perceber que é possível a introdução da escola nas culturas indígenas. Ainda que se verifique possível a introdução da escola numa determinada cultura indígena quando se consideram as fronteiras étnica como fronteiras sinuosas, é necessário perceber a educação escolar sob um ponto de vista crítico. Destaca-se que a educação constitui direito fundamental e se insere no rol de direitos humanos estabelecidos internacionalmente. A educação escolar indígena positivada em nossa Constituição, com métodos próprios de aprendizagem, constitui um êxito resultante da movimentação política indígena. No entanto, a educação escolar indígena ainda é permeada por inúmeros desafios, considerando a complexidade de ruptura com o paradigma escolar anterior, que não respeitou a autodeterminação. Não obstante os inúmeros entraves que abrangem a questão, é necessário observar os objetivos do recente paradigma escolar: manutenção da identidade e das práticas sociais, emancipação e autodeterminação. Amparar a existência de uma educação escolar diferenciada e de qualidade para os indígenas é uma resposta possível para alcançar o protagonismo indígena nos espaços institucionais de diálogo entre a minoria e o grupo dominante, inclusive no processo de formulação de políticas públicas. ____________________________________________________________________________ ABSTRACTIn 1500, Europeans arrived in Brazil and found a wide diversity of people. Besides physical forms of violence, they also used symbolic forms. And these were often followed by an educational civilizing project which did not respect the singularities of those people. The latest school educational paradigm, which is an emancipatory kind, aims to empower indigenous. When considering ethnic boundaries as sinuous borders, we realize that there is a possibility to introduce school in indigenous cultures. Although there is a possible introduction of a particular school in an indigenous culture, when considering ethnic boundaries as sinuous borders, it is necessary to perceive school education from a critical point of view. It is important to emphasize that education is a fundamental right and that it is inserted in the list of human rights recognized internationally. The indigenous education positively valued in our constitution, which has its own learning methods, is an achievement of the indigenous political movement. However, indigenous education is still permeated by several challenges, considering the complexity of rupture with the previous school paradigm that did not respect self-determination. Despite the barriers that address the issue, it is necessary to observe the aims of the recent school paradigm: maintenance of indigenous identity and social practices, empowerment and selfdetermination. Giving support to the existence of a differentiated and quality education to indigenous peoples is possible to reach the indigenous leadership in the institutional places of dialogue between the minority and the dominant group, even in the public policy making process

H, C, and N isotopic compositions of Hayabusa category 3 organic samples

Since isotopic ratios of H, C, and N are sensitive indicators for determining extraterrestrial organics, we have measured these isotopes of Hayabusa category 3 organic samples of RB-QD04-0047-02, RA-QD02-0120, and RB-QD04-0001 with ion imaging using a NanoSIMS ion microprobe. All samples have H, C, and N isotopic compositions that are terrestrial within errors (approximately ±50‰ for H, approximately ±9‰ for C, and approximately ±2‰ for N). None of these samples contain micrometer-sized hot spots with anomalous H, C, and N isotopic compositions, unlike previous isotope data for extraterrestrial organic materials, i.e., insoluble organic matters (IOMs) and nano-globules in chondrites, interplanetary dust particles (IDPs), and cometary dust particles. We, therefore, cannot conclude whether these Hayabusa category 3 samples are terrestrial contaminants or extraterrestrial materials because of the H, C, and N isotopic data. A coordinated study using microanalysis techniques including Fourier transform infrared spectrometry (FT-IR), time-of-flight secondary ion mass spectrometry (ToF-SIMS), NanoSIMS ion microprobe, Raman spectroscopy, X-ray absorption near edge spectroscopy (XANES), and transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) is required to characterize Hayabusa category 3 samples in more detail for exploring their origin and nature.This research was supported by the JSPS Strategic Fund for Strengthening Leading-edge Research and Development to the JAMSTEC

A Fly-Through Mission Strategy Targeting Peptide as a Signature of Chemical Evolution and Possible Life in Enceladus Plumes

In situ detection of organic molecules in the extraterrestrial environment provides a key step towards better understanding the variety and the distribution of building blocks of life and it may ultimately lead to finding extraterrestrial life within the Solar System. Here we present combined results of two separate experiments that enable us to realize such in situ life signature detection from the deep habitats of the "Ocean World": a hydrothermal reactor experiment simulating complex organic synthesis and a simulated fly-through capture experiment of organic-bearing microparticles using silica aerogels, followed by subsequent analysis. Both experiments employ peptide as a plausible organics existing in Encleadus plume particles produced in its subsurface ocean. Recent laboratory hydrothermal experiments and a theoretical model on silica saturation indicated an on going hydrothermal reactions in subsurface Enceladus ocean. Given the porous chondritic origin of the core, it is likely that organic compounds originated by radiation chemistry such as amino acid precursors could have been provided, leached, and altered through widespread water-rock interactions. By using the same laboratory experimental setup from the latest water-rock interaction study, we performed amino acid polymerization experiments for 144 days and monitored the organic complexity changing over time. So far over 3,000 peaks up to the size of greater than 600 MW were observed through the analysis of capillary electrophoresis time-of-flight mass spectrometry (CE-TOF-MS) with an indication of amino acid derivatives and short peptides. Generally abiotic polymerization of enantiomeric amino acids results in forming stereoisomeric peptides with identical molecular weight and formula as opposed to homochiral biopolymers. Assuming Enceladus plume particles may contain a mixture of stereoisomeric peptides, we were able to distinguish 16 of the 17 stereoisomeric tripeptides as a test sample using capillary electrophoresis (CE) under optimized conditions. We further conducted Enceladus plume fly-through capture experiment by accelerating peptides soaked in rock particles up to a speed of 5.7 km/s and capturing with originally developed hydrophobic silica aerogels. Direct peptide extraction with acetonitrile-water followed by CE analysis led to detection of only but two stereoisomeric acidic peptide peaks, presenting the first run-through hypervelocuty impact sample analysis targeting peptides as key molecule to to understand the ongoing astrobiology on Enceladus

Sequential analysis of carbonaceous materials in Hayabusa-returned samples for the determination of their origin

Preliminary results of the analyses of five carbonaceous materials (particle size of approximately 50 μm) from the Hayabusa spacecraft sample catcher, including their texture, chemistry, and chemical/isotopic compositions, are summarized. The carbonaceous particles underwent sequential analysis using a series of microanalytical instruments located at several research institutes and universities. Collected particles were initially classified into four categories: two categories containing extraterrestrial silicate particles, one category containing metal and quartz particles consistent with contamination from the sample catcher or sample manipulation tools, and a final category containing carbonaceous particles. Analysis of this final category was the main focus of this study. Through examination of the carbonaceous materials, the appropriate analytical processes for sample transportation and handling were optimized to minimize sample damage and terrestrial contamination. Particles were investigated by transmission electron microscopy/scanning transmission electron microscopy, and Ca-carbonate inclusions were found in one particle. In a different particle, a heterogeneous distribution of silicon in a uniform C, N, and O matrix was found. Though further analysis is required for a strict determination of particle origin, the differences in the microstructure and elemental distribution of the carbonaceous particles suggest multiple origins.TEM analyses were performed at JEOL Ltd. XANES analysis was conducted in UVSOR Facility in Institute for Molecular Science, supported by Nanotechnology Platform Program (Molecule and Material Synthesis) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan

ToF-SIMS analysis of carbonaceous particles in the sample catcher of the Hayabusa spacecraft

Three carbonaceous category 3 particles (RA-QD02-0180, RB-QD04-0037-01, and RB-QD04-0047-02) returned in the sample catcher from the Hayabusa spacecraft were analyzed by time of flight-secondary ion mass spectrometry (ToF-SIMS) to establish an analytical procedure for determination of their origins. By the different analytical schemes, the three particles gave distinct elemental and molecular ions, in which the organic carbons commonly appear to be associated with nitrogen, silicon, and/or fluorine. The particles could be debris of silicon rubber and fluorinated compounds and are therefore man-made artifacts rather than natural organic matter

X-ray absorption near edge structure spectroscopic study of Hayabusa category 3 carbonaceous particles

Analyses with a scanning transmission x-ray microscope (STXM) using x-ray absorption near edge structure (XANES) spectroscopy were applied for the molecular characterization of two kinds of carbonaceous particles of unknown origin, termed category 3, which were collected from the Hayabusa spacecraft sample catcher. Carbon-XANES spectra of the category 3 particles displayed typical spectral patterns of heterogeneous organic macromolecules; peaks corresponding to aromatic/olefinic carbon, heterocyclic nitrogen and/or nitrile, and carboxyl carbon were all detected. Nitrogen-XANES spectra of the particles showed the presence of N-functional groups such as imine, nitrile, aromatic nitrogen, amide, pyrrole, and amine. An oxygen-XANES spectrum of one of the particles showed a ketone group. Differences in carbon- and nitrogen-XANES spectra of the category 3 particles before and after transmission electron microscopic (TEM) observations were observed, which demonstrates that the carbonaceous materials are electron beam sensitive. Calcium-XANES spectroscopy and elemental contrast mapping identified a calcium carbonate grain from one of the category 3 particles. No fluorine-containing molecular species were detected in fluorine-XANES spectra of the particles. The organic macromolecular features of the category 3 particles were distinct from commercial and/or biological ‘fresh (non-degraded)’ polymers, but the category 3 molecular features could possibly reflect degradation of contaminant polymer materials or polymer materials used on the Hayabusa spacecraft. However, an extraterrestrial origin for these materials cannot currently be ruled out