Chemical evolution of the metal poor Globular Cluster NGC 6809

We present the abundances analysis for a sample of 11 red giant branch stars in the metal-poor globular cluster NGC 6809 based on high-resolution spectra. Our main goals are to characterize its chemical composition and analyze this cluster's behavior associated with the Multiple Population (MPs) phenomenon. In our work we obtained the stellar parameters and chemical abundances of 24 elements (O, Na, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Co, Sc, Ni, Cu, Zn, Y, Zr, Ba, La, Ce, Eu, Nd and Dy). We found a radial velocity of 174.7 $\pm$ 3.2 km $s^{-1}$ and a mean iron content of [Fe/H]=-2.01 $\pm$ 0.02 in good agreement with other studies. Moreover, we found a large spread in the abundances of the light elements O, Na and Al confirming the presence of a Na-O anti-correlation a Na-Al correlation. The Mg-Al anti-correlation is also present in our cluster. The $\alpha$ and iron-peak elements show good agreement with the halo field star trend. The heavy elements are dominated by the r-process.Comment: 13 pages, 11 figures, 3 tables, accepted for publication in MNRA

Automaticity of lexical access in deaf and hearing bilinguals: Cross-linguistic evidence from the color Stroop task across five languages

The well-known Stroop interference effect has been instrumental in revealing the highly automated nature of lexical processing as well as providing new insights to the underlying lexical organization of first and second languages within proficient bilinguals. The present cross-linguistic study had two goals: 1) to examine Stroop interference for dynamic signs and printed words in deaf ASL-English bilinguals who report no reliance on speech or audiological aids; 2) to compare Stroop interference effects in several groups of bilinguals whose two languages range from very distinct to very similar in their shared orthographic patterns: ASL-English bilinguals (very distinct), Chinese-English bilinguals (low similarity), Korean-English bilinguals (moderate similarity), and Spanish-English bilinguals (high similarity). Reaction time and accuracy were measured for the Stroop color naming and word reading tasks, for congruent and incongruent color font conditions. Results confirmed strong Stroop interference for both dynamic ASL stimuli and English printed words in deaf bilinguals, with stronger Stroop interference effects in ASL for deaf bilinguals who scored higher in a direct assessment of ASL proficiency. Comparison of the four groups of bilinguals revealed that the same-script bilinguals (Spanish-English bilinguals) exhibited significantly greater Stroop interference effects for color naming than the other three bilingual groups. The results support three conclusions. First, Stroop interference effects are found for both signed and spoken languages. Second, contrary to some claims in the literature about deaf signers who do not use speech being poor readers, deaf bilinguals’ lexical processing of both signs and written words is highly automated. Third, cross-language similarity is a critical factor shaping bilinguals’ experience of Stroop interference in their two languages. This study represents the first comparison of both deaf and hearing bilinguals on the Stroop task, offering a critical test of theories about bilingual lexical access and cognitive control

Space charge behaviour in epoxy laminates under high constant electric field

The development of space charge in insulating materials is one of the main causes of their electrical ageing. The pulsed electro-acoustic method is often used to determine space charge distribution, but the signal analysis in the case of laminate structures is much more complex to analyse. In this paper the authors describe and use a simulated signal in order to study laminates made of epoxy resin and fibre mat. The relatively large conductivity of the fibres compared with that of the resin seems to produce a rapid charge dissociation and recombination in the fibres. Under voltage the presence of fibres close to an electrode seems to promote charge injection

Infinite-Order Percolation and Giant Fluctuations in a Protein Interaction Network

We investigate a model protein interaction network whose links represent interactions between individual proteins. This network evolves by the functional duplication of proteins, supplemented by random link addition to account for mutations. When link addition is dominant, an infinite-order percolation transition arises as a function of the addition rate. In the opposite limit of high duplication rate, the network exhibits giant structural fluctuations in different realizations. For biologically-relevant growth rates, the node degree distribution has an algebraic tail with a peculiar rate dependence for the associated exponent.Comment: 4 pages, 2 figures, 2 column revtex format, to be submitted to PRL 1; reference added and minor rewording of the first paragraph; Title change and major reorganization (but no result changes) in response to referee comments; to be published in PR

Voices of Students who Quit Studies Amidst the Pandemic

The present study sought to describe and interpret the experiences that became the factor of the students at a selected state university in Cebu City of Bachelor of Special Needs Education to withdraw and quit studies amidst the pandemic. This research used phenomenology research design to achieve in-depth and rich first-person accounts utilizing interpretative phenomenological analysis with four stages in interpreting the data. Given the societal condition, the data gathering was held through personal conversation in Messenger with a sample size of 5. Findings revealed that the majority of the factors experienced by the respondents were about having problems with internet connection and environmental setbacks while being admitted to online learning. Financial difficulty and experiences with mental health issues were also specified from the results that influenced the decision of the respondents to discontinue their studying

Recovering 3D structural properties of galaxies from SDSS-like photometry

Because of the 3D nature of galaxies, an algorithm for constructing spatial density distribution models of galaxies on the basis of galaxy images has many advantages over surface density distribution approximations. We present a method for deriving spatial structure and overall parameters of galaxies from images and estimate its accuracy and derived parameter degeneracies on a sample of idealised model galaxies. The test galaxies consist of a disc-like component and a spheroidal component with varying proportions and properties. Both components are assumed to be axially symmetric and coplanar. We simulate these test galaxies as if observed in the SDSS project through ugriz filters, thus gaining a set of realistically imperfect images of galaxies with known intrinsic properties. These artificial SDSS galaxies were thereafter remodelled by approximating the surface brightness distribution with a 2D projection of a bulge+disc spatial distribution model and the restored parameters were compared to the initial ones. Down to the r-band limiting magnitude 18, errors of the restored integral luminosities and colour indices remain within 0.05 mag and errors of the luminosities of individual components within 0.2 mag. Accuracy of the restored bulge-to-disc ratios (B/D) is within 40% in most cases, and becomes worse for galaxies with low B/D, but the general balance between bulges and discs is not shifted systematically. Assuming that the intrinsic disc axial ratio is < 0.3, the inclination angles can be estimated with errors < 5deg for most of the galaxies with B/D < 2 and with errors < 15deg up to B/D = 6. Errors of the recovered sizes of the galactic components are below 10% in most cases. In general, models of disc components are more accurate than models of spheroidal components for geometrical reasons.Comment: 15 pages, 13 figures, accepted for publication in RA

Two-tape finite automata with quantum and classical states

{\it Two-way finite automata with quantum and classical states} (2QCFA) were introduced by Ambainis and Watrous, and {\it two-way two-tape deterministic finite automata} (2TFA) were introduced by Rabin and Scott. In this paper we study 2TFA and propose a new computing model called {\it two-way two-tape finite automata with quantum and classical states} (2TQCFA). First, we give efficient 2TFA algorithms for recognizing languages which can be recognized by 2QCFA. Second, we give efficient 2TQCFA algorithms to recognize several languages whose status vis-a-vis 2QCFA have been posed as open questions, such as $L_{square}=\{a^{n}b^{n^{2}}\mid n\in \mathbf{N}\}$. Third, we show that $\{a^{n}b^{n^{k}}\mid n\in \mathbf{N}\}$ can be recognized by {\it $(k+1)$-tape deterministic finite automata} ($(k+1)$TFA). Finally, we introduce {\it $k$-tape automata with quantum and classical states} ($k$TQCFA) and prove that $\{a^{n}b^{n^{k}}\mid n\in \mathbf{N}\}$ can be recognized by $k$TQCFA.Comment: 25 page

Terahertz emission from the intrinsic Josephson junctions of high-symmetry thermally-managed Bi2Sr2CaCu2O8+δ microstrip antennas

We show for high-symmetry disk, square, or equilateral triangular thin microstrip antennas of any composition respectively obeying C∞v, C4v, and C3v point group symmetries, that the transverse magnetic electromagnetic cavity mode wave functions are restricted in form to those that are one-dimensional representations of those point groups. Plots of the common nodal points of the ten lowest-energy non-radiating two-dimensional representations of each of these three symmetries are presented. For comparison with symmetry-broken disk intrinsic Josephson junction microstrip antennas constructed from the highly anisotropic layered superconductor Bi2 Sr2 CaCu2 O8+δ (BSCCO), we present plots of the ten lowest frequency orthonormal wave functions and of their emission power angular distributions. These results are compared with previous results for square and equilateral triangular thin microstrip antennas

Webinar Karier: Pilih Prodi yang Tepat untuk Tren Pekerjaan Zaman Now

CAREER WEBINAR: CHOOSE THE RIGHT STUDY PROGRAM FOR TODAY’S JOB TRENDS. The Webinar this time is an activity of the Community Service Team from UPH Business School to Harapan Utama High School, Batam. Based on the results of discussions regarding training needs with related parties, this PKM was carried out with the aim of providing training on choosing majors in higher education for students. With the implementation of this PKM, it is hoped that it can encourage and contribute to the development of knowledge and understanding for students regarding how to choose majors and contemporary work trends that suit their interests and talents and how to prepare themselves to include planning and how to study properly to succeed in the future