Polarized s-quark Distribution in Charmed Hadron Leptoproduction

In order to extract the polarized strange quark density in proton, we studied the semi-inclusive $\Lambda_c$/$\bar{\Lambda}_c$ leptoproduction in charged current DIS at THERA energies. We indicate that measurements of the spin correlation between the incident proton and the produced $\Lambda_c$/$\bar{\Lambda}_c$ baryon gives us information about the polarized strange quark distribution.Comment: 6 pages including 2 figures. Talk given at SPIN2001 (The 3rd Circum-Pan-Pacific Symposium on "High Energy Spin Physics"), Beijing, China, Oct. 200

Chemical Vapor Deposition Model of Polysilicon in a Trichlorosilane and Hydrogen System

The traditional polysilicon processes should be refined when addressing the low energy consumption requirement for the production of solar grade silicon. This paper addresses the fluid dynamic conditions required to deposit polysilicon in the traditional Siemens reactor. Analytical solutions for the deposition process are presented, providing information on maximizing the rate between the amount of polysilicon obtained and the energy consumed during the deposition process. The growth rate, deposition efficiency, and power-loss dependence on the gas velocity, the mixture of gas composition, the reactor pressure, and the surface temperature have been analyzed. The analytical solutions have been compared to experimental data and computational solutions presented in the literature. At atmospheric pressure, the molar fraction of hydrogen at the inlet should be adjusted to the range of 0.85–0.90, the gas inlet temperature should be raised within the interval of 673 and 773 K, and the gas velocity should reach the Reynolds number 800. The resultant growth rate will be between 6 and 6.5 _m min−1. Operation above atmospheric pressure is strongly recommended to achieve growth rates of 20 _m min−1 at 6 atm

The labour trajectories of immigrant women in Spain: are there signs of upward social mobility?

BACKGROUND In Spain, foreign-born women are disproportionately employed in housework or care work, and quantitative research has shown that female migrants are disadvantaged relative to male migrants in the occupational status of their first job in Spain. However, the process that created this female penalty has not yet been explored. OBJECTIVE In this paper, we focus on female occupational mobility at migration and during settlement in Spain. First, we compare female and male labour mobility at migration. Second, we identify the main socio-demographic factors which increase the likelihood that the first job a foreign-born woman holds in Spain will be as a cleaner or a domestic worker. Third, we investigate female labour mobility from the time of migration, particularly trajectories that lead away from the cleaning and domestic occupations, and consider the importance of the assimilation process in occupational mobility. METHODS We apply quantitative methods to Spain's 2007 National Immigrant Survey (Encuesta Nacional de Inmigrantes), using descriptive (mobility matrixes) and simple and multinomial logistic regression analyses. We include the main socio-demographic, family, and migratory characteristics of immigrants in the explanatory models. RESULTS The results of our analysis revealed that female migrants to Spain are more likely than their male counterparts to experience occupational downgrading at the time of migration, and that 41.6% of women work in domestic services in their first job in Spain. Finally, our results have demonstrated that, although occupational immobility is common among female migrants in Spain, movement out of domestic services is possible, especially for the most assimilated immigrant women. CONCLUSIONS This paper contextualises female immigration in Spain, attributing the labour market choices made by female migrants to the externalisation of domestic and cleaning occupations in private households, and to the gender segmentation of the labour market

La inserción de las mujeres inmigradas en el mercado de trabajo español

La creciente presencia femenina entre la población inmigrada en España ha hecho necesario replantearse el estudio de la misma desde una perspectiva de género. En el presente trabajo, se hace un recorrido por las principales aportaciones científicas centradas en la inmigración femenina y, de manera específica, en su inserción en el mercado de trabajo español. Se identifica la demanda creciente de trabajadoras para el servicio doméstico como la razón principal de la llegada de las mujeres no comunitarias, dentro de la internacionalización de las funciones de reproducción social. El resultado ha sido la existencia de la complementariedad sociodemográfica entre la mano de obra femenina inmigrada y la autóctona, dadas las diferencias en sus patrones de actividad y en las posiciones laborales que ocupan. Las siguientes páginas reúnen, asimismo, los principales estudios sobre la movilidad laboral, desde el servicio doméstico hacia otras actividades económicas de las trabajadoras inmigradas.L'augment de la presència femenina entre la població immigrada a Espanya ha fet necessari replantejar-se'n l'estudi des de la perspectiva de gènere. En aquest treball, s'hi realitza un recorregut per les principals aportacions científiques centrades en la immigració femenina i, de manera més concreta, en la seva inserció en el mercat de treball espanyol. S'hi identifica la creixent demanda de treballadores per al servei domèstic com la raó principal de l'arribada de les dones no comunitàries, en el context de la internacionalització de les funcions de reproducció social. Ateses les diferències en els patrons d'activitat i en les posicions laborals que ocupen, existeix una complementarietat sociodemogràfica entre la mà d'obra femenina immigrada i l'autòctona. Les pàgines següents reuneixen, així mateix, els estudis principals sobre la mobilitat laboral de les treballadores immigrades, des del servei domèstic fins a unes altres activitats econòmiques.L'introduction de la perspective de genre dans les études sur la migration en Espagne a été nécessaire du fait de l'intensification de l'immigration féminine. Cet article présente les principales contributions scientifiques à l'étude des migrations des femmes, et plus spécifiquement, à l'étude de l'insertion de cette population sur le marché du travail espagnol. La plupart des auteurs ont identifié le besoin en main-d'oeuvre destinées aux tâches ménagères comme la principale cause de cette immigration de femmes non-communautaires, dans le cadre d'une internalisation du processus de reproduction sociale. Il existe une complémentarité entre les forces de travail féminines natives et immigrées compte tenu des différences de parcours professionnels et de postes occupées. Les pages qui suivent résument l'étude la plus importante sur la mobilité des femmes sur le marché du travail, des tâches ménagères vers d'autres activités.The increasing number of female immigrants in Spain made the introduction of the gender perspective in its analysis necessary. This paper quotes the main scientific contributions to the study of immigrant women and, more specifically, in their insertion in the Spanish Labour Market. Demand of female workers for the domestic service, is identified by most of the authors, as the most important cause of arrival of non-communitarian women. Therefore, it would be part of the internationalization of the social reproduction process. Differences between activity trends and labour positions indicate that there is socio-demographic complementarity between the immigrant and the native female labour force The next pages summarize the most notorious study on immigrant women's labour mobility from domestic service to other activities

Características de las madres primerizas y de los padres primerizos en la España del siglo XXI

Este trabajo analiza la primofecundidad femenina y masculina en España entre 1999 y 2015. A través de la Encuesta de Población Activa en su versión panel, la probabilidad de tener un primer hijo se controla por edad y periodo de observación, y las variables independientes son el lugar de nacimiento, el nivel de instrucción y la relación con la actividad. Los resultados confirman el aplazamiento de la primera fecundidad entre los hombres y mujeres con mayor nivel educativo. La pervivencia de un patrón de género explicaría la mayor probabilidad de primera maternidad de las inactivas, mientras que el trabajo es indispensable para ser padre primerizo. No obstante, el desempleo y la temporalidad afectan negativamente a ambos sexos. La aportación de la población inmigrada queda confirmada especialmente por su calendario temprano.This study examines female and male first-time parents in Spain between 1999 and 2015. Based on the Labor Force Survey in its panel version, the probability of having a first child is controlled by age and observation period, using the independent variables of place of birth, educational attainment and employment status. Results confirm a delay in first parity births for men and women having a higher education level. The continuance of a gender pattern explains the higher probability of first-time maternity in inactive women, whereas work is indispensable for being a first-time father. However, unemployment and temporary employment negatively affect both genders. The contribution of the immigrant population is confirmed, especially due to its early timetable

Ultrapurification of Silicon for Photovoltaic Applications

The recent explosive growth of Photovoltaics and the relative avidity for silicon of the predominant solar cell technology have resulted in a dramatic change of the polysilicon industry structure. While in the past the polysilicon was manufactured almost exclusively for the semiconductor industry, now more than half of the market is devoted to the solar industry. The different alternative routes to purify silicon for photovoltaic applications are presented in the paper, analysing their advantages and drawbacks. Emphasis is made on the CENTESIL initiative, a new private-public partnership venture promoting a pilot plant that is in an advanced state of construction. The goal is to allow the photovoltaic companies worldwide to count with an independent research centre to help them to establish their own polysilicon plant

Physics of Vibrating Airfoils at Low Reduced Frequency

The unsteady aerodynamics of low pressure turbine vibrating airfoils in flap mode is studied in detail using a frequency domain linearized Navier-Stokes solver. Both the travelling-wave and influence coefficient formulations of the problem are used to highlight key aspects of the physics and understand different trends such as the effect of reduced frequency and Mach number. The study is focused in the low-reduced frequency regime which is of paramount relevance for the design of aeronautical low-pressure turbines and compressors. It is concluded that the effect of the Mach number on the unsteady pressure phase can be neglected in first approximation and that the unsteadiness of the vibrating and adjacent airfoils is driven by vortex shedding mechanisms. Finally a simple model to estimate the work-per-cycle as a function of the reduced frequency and Mach Number is provided. The edge-wise and torsion modes are presented in less detail but it is shown that acoustic waves are essential to explain its behaviour. The non-dimensional work-per-cycle of the edge-wise mode shows a large dependence with the Mach number while in the torsion mode a large number of airfoils is needed to reconstruct the work-per-cycle departing from the influence coefficients

Radiation heat savings in polysilicon production: validation of results through a CVD laboratory prototype

This work aims at a deeper understanding of the energy loss phenomenon in polysilicon production reactors by the so-called Siemens process. Contributions to the energy consumption of the polysilicon deposition step are studied in this paper, focusing on the radiation heat loss phenomenon. A theoretical model for radiation heat loss calculations is experimentally validated with the help of a laboratory CVD prototype. Following the results of the model, relevant parameters that directly affect the amount of radiation heat losses are put forward. Numerical results of the model applied to a state-of-the-art industrial reactor show the influence of these parameters on energy consumption due to radiation per kilogram of silicon produced; the radiation heat loss can be reduced by 3.8% when the reactor inner wall radius is reduced from 0.78 to 0.70 m, by 25% when the wall emissivity is reduced from 0.5 to 0.3, and by 12% when the final rod diameter is increased from 12 to 15 cm

Households economically headed by women in times of expansion and crisis (1999-2012) : the case of Latin American migrants in Spain

The arrival of flows of Latin-American females in Spain has been closely linked to the demand for domestic workers and carers. During the last period of economic expansion, a subsequent masculinization of these Latin American flows was seen, explaining the trend toward greater gender and occupational balance among these families. An economic recession followed, however, and unemployment impacted men more than it did women, as reflected in the rise in the number of women who became the sole breadwinners in their households. Using the Economically Active Population Survey, we explore the nature of these household structures, the changes in relation to the economic context, and the socio-demographic and labour market characteristics. Female-headed households are defined as those nuclear households where women are the only economic providers. The first of two hypotheses was a greater incidence of female-headed households among Latin American migrants than among households headed by exogamous and Spanish couples, irrespective of other socio-demographic characteristics. The second hypothesis predicted a greater incidence of female-headed households during the recent years of economic crisis. Furthermore, we expected this increase to have occurred in all households but to have been particularly high among Latin-Americans. The results confirm the prevalence of Latin American women as female heads of households and the adjustment within families in line with the changing Spanish socioeconomic and migratory context between 1999 to 2012