New accurate measurement of 36ArH+ and 38ArH+ ro-vibrational transitions by high resolution IR absorption spectroscopy

The protonated Argon ion, $^{36}$ArH$^{+}$, has been identified recently in the Crab Nebula (Barlow et al. 2013) from Herschel spectra. Given the atmospheric opacity at the frequency of its $J$=1-0 and $J$=2-1 rotational transitions (617.5 and 1234.6 GHz, respectively), and the current lack of appropriate space observatories after the recent end of the Herschel mission, future studies on this molecule will rely on mid-infrared observations. We report on accurate wavenumber measurements of $^{36}$ArH$^{+}$ and $^{38}$ArH$^{+}$ rotation-vibration transitions in the $v$=1-0 band in the range 4.1-3.7 $\mu$m (2450-2715 cm$^{-1}$). The wavenumbers of the $R$(0) transitions of the $v$=1-0 band are 2612.50135$\pm$0.00033 and 2610.70177$\pm$0.00042 cm$^{-1}$ ($\pm3\sigma$) for $^{36}$ArH$^{+}$ and $^{38}$ArH$^{+}$, respectively. The calculated opacity for a gas thermalized at a temperature of 100 K and a linewidth of 1 km.s$^{-1}$ of the $R$(0) line is $1.6\times10^{-15}\times N$($^{36}$ArH$^+$). For column densities of $^{36}$ArH$^+$ larger than $1\times 10^{13}$ cm$^{-2}$, significant absorption by the $R$(0) line can be expected against bright mid-IR sources

Improved determination of the 1(0)-0(0) rotational frequency of NH3D+ from the high resolution spectrum of the v4 infrared band

The high resolution spectrum of the v4 band of NH3D+ has been measured by difference frequency IR laser spectroscopy in a multipass hollow cathode discharge cell. From the set of molecular constants obtained from the analysis of the spectrum, a value of 262817(6) MHz (3sigma) has been derived for the frequency of the 1(0)-0(0) rotational transition. This value supports the assignment to NH3D+ of lines at 262816.7 MHz recorded in radio astronomy observations in Orion-IRc2 and the cold prestellar core B1-bS.Comment: Accepted for publication in the Astrophysical Journal Letters 04 June 201

Education Trajectories : From Early Childhood to Early Adulthood in Peru

Over the past few decades, every President in Peru has proclaimed education as a priority; yet, in spite of recent progress across several indicators, educational outcomes are still on average low, and gaps between students large and closely linked with their individual and family background. This paper looks at the education trajectories of children in different stages of life, using data from Young Lives, an international study that follows two groups of children: an Older Cohort (born in 1994) and a Younger Cohort (born in 2001). According to the Peruvian Constitution and General Education Law, education is considered a human right, and all students should have access to a quality service. However, results from our study and others suggest that while there have been important advances over the past two decades, there is still a long way to go for this to become a reality for everyone. Peruvian early childhood education consists of two types of preschool: Jardines, which are located in urban areas, and PRONOEI, which are usually in rural or impoverished areas. While attendance in preschool education has increased recently, our results show that by the age of 5 there are already differences in abilities that are related to family background. Furthermore, even after adjusting for these, children from Jardines have higher results in primary school than children from PRONOEI. Peruvian children are expected to attend primary school during middle childhood (ages 6 to 12), and most do. When we compare overage instances between the Older and Younger Cohort, it has been reduced, which is positive as more children are in their normative grade. Achievement in national and international assessments, as well as our own data, also show increases on average scores along with large gaps by wealth, area of residence, maternal education, and ethnicity. Regarding the latter, while Peruvian law states that children have the right to learn in their mother language, our results show that almost 39 per cent of indigenous children learn in Spanish only. In general, we find that educational opportunities are not fairly distributed. For example, urban schools (public and private) congregate richer, Spanish-speaking students and have better resources and more pedagogically able teachers; these students in turn have higher test results. During adolescence, children are expected to attend secondary schools. Overage at age 15 is higher than in primary, and continues to be related to the family background of students. During this period, we also find large gaps in achievement by student background. In regards to early adulthood, by about age 17 children should have finished secondary school: we found that nearly 68 per cent of our cohort had finished school at age 19 (42 per cent finished on age and 26 per cent overage); 20 per cent of adolescents had dropped out of school. Beyond secondary, young adults from Spanish-speaking homes, wealthier, and with more educated mothers (who had completed secondary education or above), are more likely to attend universities. Additionally, more than 38 per cent of the sample only worked and did not study at age 19; and in the case of women, 25 per cent already had children. Progress in enrolment and average achievement is clear in the educational trajectories of the two cohorts of children from early childhood to adulthood. This reflects the importance the population and successive governments have attributed to education. However, large disparities remain, related to students´ and family’s characteristics. In basic education, inequality is not related so much to access to school as it is to the educational opportunities children have at school, and their results in standardised tests. Children who come from relatively poor families, are indigenous, have a mother with less than complete secondary education, or who live in a rural family tend to have fewer opportunities and lower outcomes than their peers; the situation is worse for those who combine several of these family characteristics. Fortunately, disparities in opportunities and achievement by sex are relatively small. In tertiary education, there are still large gaps in access between groups, with privileged students having more access to university studies. Our conclusion is that the educational system may be reinforcing inequalities since it does not provide equal opportunities for all children; ideally, it should prioritise the opportunities of children and young adults who we know are more likely to have poor educational outcomes (i.e. vulnerable children). This should start at a young age, as we have found that gaps in achievement are evident by the age of 5. There are reasons to be optimistic, however, as public funding in education is increasing rapidly. In this scenario, we suggest that inequality in educational opportunities and outcomes becomes a priority

Detection of the Ammonium Ion in Space

We report on the detection of a narrow feature at 262816.73 MHz towards Orion and the cold prestellar core B1-bS, that we attribute to the 1(0)-0(0) line of the deuterated Ammonium ion, NH3D+. The observations were performed with the IRAM 30m radio telescope. The carrier has to be a light molecular species as it is the only feature detected over 3.6 GHz of bandwidth. The hyperfine structure is not resolved indicating a very low value for the electric quadrupolar coupling constant of Nitrogen which is expected for NH3D+ as the electric field over the N nucleus is practically zero. Moreover, the feature is right at the predicted frequency for the 1(0)-0(0) transition of the Ammonium ion, 262817(6) MHz (3sigma), using rotational constants derived from new infrared data obtained in our laboratory in Madrid. The estimated column density is 1.1(0.2)e12 cm-2. Assuming a deuterium enhancement similar to that of NH2D, we derive N(NH4+) sim 2.6e13 cm-2, i.e., an abundance for Ammonium of a few 1e(-11).Comment: Accepted for publication in the Astrophysical Journal Letters 04 June 201

New accurate measurement of ³⁶ArH+ and ³⁸ArH+ ro-vibrational transitions by high resolution IR absorption spectroscopy

The protonated argon ion, 36ArH+, was recently identified in the Crab Nebula from Herschel spectra. Given the atmospheric opacity at the frequency of its J = 1-0 and J = 2-1 rotational transitions (617.5 and 1234.6 GHz, respectively), and the current lack of appropriate space observatories after the recent end of the Herschel mission, future studies on this molecule will rely on mid-infrared observations. We report on accurate wavenumber measurements of 36ArH+ and 38ArH+ rotation-vibration transitions in the v = 1-0 band in the range 4.1-3.7 μm (2450-2715 cm–1). The wavenumbers of the R(0) transitions of the v = 1-0 band are 2612.50135 ± 0.00033 and 2610.70177 ± 0.00042 cm–1 (±3σ) for 36ArH+ and 38ArH+, respectively. The calculated opacity for a gas thermalized at a temperature of 100 K and with a linewidth of 1 km s–1 of the R(0) line is 1.6 × 10–15 × N(36ArH+). For column densities of 36ArH+ larger than 1 × 1013 cm–2, significant absorption by the R(0) line can be expected against bright mid-IR sources

A proper generalized decomposition approach for high-order problems

En este artículo se desarrollan dos aproximaciones distintas para la resolución de problemas de alto orden mediante métodos de descomposición propia generalizada (PGD, del inglés Proper Generalized Decomposition ). La primera está basada en el uso de técnicas de colocación y polinomios de Chebyshev, mientras que la segunda se basa en el uso de polinomios de Hermite en el marco de una formulación de Galerkin. Ambas poseen ventajas e inconvenientes, que se analizan en detalle con la ayuda de distintos problemas clásicos de validación.In this paper two different approximations for the solution of high-order problems by proper generalized decompositions (PGD) are developed. The first one is based upon the use of collocation techniques, along with Chebyshev polynomials, while the second employs Hermite polynomials in a Galerkin framework. Both approaches having pros and cons, they are studied with the help of some classical benchmark tests.Peer Reviewe

Petrology and geochemistry of Cardeña-Virgen de La Cabeza pluton (batholith of Los Pedroches)

[Resumen] El plutón de Cardeña-Virgen de La Cabeza es uno de los cuerpos intrusivos que integran la unidad granítica del batolito de Los Pedroches. Dentro de este plutón, se ha establecido el emplazamiento sucesivo en el tiempo de: 1) adamellitas biotíticas, 2) granitos biotíticos porfídicos ± cordierita, 3) leucogranitos ± cordierita. Las adamellitas biotíticas muestran localmente paso gradual hacia las facies granodioríticas del batolito. Existe además un importante complejo filoniano que se intruye posteriormente, formado por diques riodacíticos de dirección NO-SE, lamprófidos, aplitas, pegmatitas y filones mineralizados· de cuarzo. Geoquímicamente, la adamellita y el granito biotítico porfídico constituyen una asociación alumino-cafémica de carácter calcoalcalino. Los enclaves anfibólicos (términos cafémicos) poseen carácter metaaluminoso. Los leucogranitos se desvían de la tendencia general definiendo una asociación aluminosa y leucocrática. Los diagramas de variación para elementos mayores, menores, trazas y tierras.raras de adamellitas, granitos biotíticos porfídicos y de granodioritas, rocas, estas últimas, con las que se encuentran íntimamente relacionadas, son compatibles con procesos de diferenciación magmática por cristalización fraccionada a partir de un magma inicial de composición granodiorítica más básico[Abstract] The Cardeña-Virgen de La Cabeza intrusion belongs to the granitic unit of the Los Pedroches batholith. the chronology of the intrusion of the different rocktypes that make up the pluton is as follows: 1) biotitic adamellite, 2) porphyritic, cordierite-bearing, biotitic granite. 3) cordierite bearing leucogranite. The biotitic adamellite locally shows a transition to the granodioritic facies of the batholith. A great amount ofNW-SW oriented dikes with rhyodacitic composition intruded subsequently. Lampophyres, aplites, pegmatites and ore-bearing quartz veins complete the dike complexo Adamellite and biotitic ganite define an aluminous-cafemic association with calcalkaline affinity. The amphibole-bearing enclaves represent the cafemic terms of the series and have a metaaluminous character.The leucogranite deviates from the general trend defining and aluminous, leucocratic association. Variation diagrams for major, minor and trace elements, including REE, of adamallite, porphyritic biotitic granite and granodiorite of the main pluton (which is intimately associated with the Cardeña-Virgen de La Cabeza intrusion) suggest a process of magmatic differentiation through fractional crystallization starting from a slightly more basic granodioritic magma