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

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

The labour complementarity between international migration and national labour force in Spain, from a gender perspective

Comunicació presentada al 3rd European Workshop on "Labour Markets and Demographic Change". Organitzat pel Max Planck Institute for Demographic Research; Rostock Center for Research on Demographic Change; Department of Economics, University of Rostock. Rostock (Alemanya), 24 i 25 d'abril de 2008.Using the Spanish Labour Force Survey from 1999 to 2006, this article compares the distribution of foreign and national workers within the Spanish labour market. The initial hypothesis states that in the context of a segmented labour market, the recently arrived foreign population has filled the more precarious labour positions of the "secondary labour segment", allowing younger Spanish generations to occupy more skilled and stable occupations in accordance with educational attainment. This labour insertion has not only a national pattern but also a gendered one. Effectively, the increasing demand for immigrant women is a response to the improvement of the educational and socio-economic position of young female generations in Spain. We first carry out a descriptive analysis of the labour characteristics of the national and foreign population in Spain. In the second part of the analysis, using multivariable logistic regression models analysis, we attempt to establish that differentials in the labour attainment of nationals and foreigners are not only due to personal characteristics (educational levels, etc.) but also to gender and national identity.L'article compara, a través de les dades de la Encuesta de Población Activa (EPA) i, pel període 1999-2006, la distribució dels treballadors estrangers i nacionals en el mercat de treball espanyol. La hipòtesi inicial apunta que, en un mercat segmentat, els estrangers acabats d'arribar, ocupen les posicions més precàries del "segment de treball secundari", el que permet als joves espanyols ocupar aquelles posicions laborals més qualificades en relació al seu nivell d'instrucció. La inserció laboral no només segueix unes pautes diferenciades segons la nacionalitat, sinó també en funció del sexe. L'augment de la demanda de treballadors estrangers és una conseqüència de la millora educativa i de la posició socioeconòmica de les joves generacions femenines a Espanya. A la primera part de l'article, es desenvolupa un anàlisi descriptiu dels trets laborals de la població espanyola i estrangera. A la segona part, a partir de la tècnica de la regressió logística, es creen models multivariables per explicar com, les diferències entre les posicions laborals de nacionals i estrangers no venen només propiciades per les característiques dels treballadors (com el nivell d'instrucció), sinó també per diferències de gènere o per la nacionalitat dels mateixos.Este artículo compara, a través de los datos de la Encuesta de Población Activa (EPA) y para el periodo 1999-2006, la distribución de los trabajadores extranjeros y nacionales en el mercado de trabajo español. La hipótesis inicial apunta que, en un mercado segmentado, los extranjeros recién llegados ocupan las posiciones más precarias del "segmento de trabajo secundario" permitiendo a los jóvenes españoles ocupar aquellas posiciones laborales más cualificadas, en relación a su nivel educativo. Además, esta inserción laboral no solamente sigue unas pautas diferenciadas según la nacionalidad, sino también en función del sexo. Efectivamente, el aumento de la demanda de trabajadores extranjeros es una consecuencia de la mejora educativa y de la posición socio-económica de las jóvenes generaciones femeninas en España. En la primera parte del artículo, se desarrolla un análisis descriptivo de las características laborales de la población española y extranjera. En la segunda parte, a partir de la técnica de la regresión logística, se crean modelos multivariables para explicar cómo las diferencias entre las posiciones laborales de nacionales y extranjeros no son causadas solamente por características de los trabajadores (como el nivel de instrucción), sino también por diferencias de género o la nacionalidad de los mismos

Coffee and Caffeine Consumption for Human Health

The year 2019 has been prolific in terms of new evidence regarding the effects of coffee and caffeine consumption on diverse aspects of human functioning. This book collects 20 high-quality manuscripts published in Nutrients that include original investigation or systematic review studies of the effects of caffeine intake on human performance and health. The diversity of the articles published in this Special Issue highlights the extent of the effects of coffee and caffeine on human functioning, while underpinning the positive nature of most of these effects. This book will help with understanding why the natural sources of caffeine are so widely present in the nutrition behaviors of modern society

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

Moving toward Professional Self-Authorship: A Case Study of Participants in a Program for Students Pursuing Faculty Careers

This study in-progress explores the perspectives and practices of students enrolled in the Preparing Future Faculty program at a large, state-sponsored research university. The motivation for this study is the need to understand the impact of this program on participants’ pathways through graduate school, their experiences teaching, and their preparation for postdoctoral positions. The theory of Self-Authorship will provide a structure to consider students’ experiences within the PFF program, how they have been affected by those experiences, and the extent to which these experiences affect (or affected) their perceptions, intentions, and actions. A case study approach using a survey, asynchronous focus groups, document review, and individual interviews is being employed. By examining this PFF program and understanding how students narrate their experiences during and following the program, we can begin to explore how a PFF program can support graduate student development in conjunction with discipline-specific graduate studies. Results will aid in the continual improvement of PFF programs and complement existing research by examining the role of self-authorship in future faculty development

Les altres catalanes : formar família abans o després de la migració?

Atès que la formació familiar i l'experiència migratòria són dos esdeveniments que acostumen a donar-se en moments molt propers a les trajectòries vitals de les dones migrants, el nostre interès és analitzar-ne tant els calendaris com la relació temporal entre aquests esdeveniments. D'una banda, descrivim les pautes d'edat d'arribada a Catalunya, de formació de la primera unió estable i de naixement del primer fill. D'altra banda, fem l'anàlisi de supervivència a l'inici de la vida familiar d'aquelles dones nascudes fora de Catalunya que van migrar sense haver estat mai unides i sense haver tingut fills. Comparem les dones arribades a Catalunya des de la resta d'Espanya durant la segona meitat del segle xx amb les migrants arribades de l'estranger a l'inici del segle xxi. L'objectiu és esbrinar si hi ha elements comuns o divergents entre les seves pautes de primera unió i primera maternitat.Dado que la formación de una familia y la experiencia migratoria son dos procesos que acostumbran a acontecer de manera próxima en el tiempo en las trayectorias vitales de las mujeres migrantes, nuestro interés es analizar tanto los calendarios respectivos como la relación temporal entre los mismos. Por una parte, describimos las pautas de edad de llegada a Cataluña, de formación de la primera unión estable y de nacimiento del primer hijo. Por otra, analizamos la supervivencia al inicio de la vida familiar de aquellas mujeres nacidas fuera de Cataluña que migraron sin haber estado nunca unidas y sin haber tenido hijos. Comparamos las mujeres llegadas a Cataluña desde el resto de España durante la segunda mitad del siglo xx con las migrantes llegadas desde el extranjero a inicios del siglo xxi. El objetivo es identificar si hay elementos comunes o divergentes entre sus pautes de primo unión y de primo maternidad.Since forming a family and migration experience are two processes that tend to occur with little difference in time in life stories of migrant women, our interest is to analyse both calendars as well as the temporal relationship between them. First, we describe the patterns of age when arriving to Catalonia, when forming the first stable union and when giving first birth. In addition, we performed a survival analysis at the beginning of family life for women born outside Catalonia who migrated without ever having been in a stable union or being childless. We compared the women who migrated to Catalonia from the rest of Spain during the second half of the 20th Century with the foreign-born migrant arrived at the beginning of 21st Century. Our goal is to identify which elements are common and which are divergent among their patterns of first-union and first-child.Vu que la formation d'une famille et l'expérience de la migration sont deux événements qui ont tendance à se produire presque au même temps dans les trajectoires de vie des femmes migrantes, notre intérêt est d'analyser aussi bien les respectifs calendriers et le rapport temporaire entre ces deux expériences. D'un côté, nous décrivons les patrons d'âge au moment de l'arrivée en Catalogne, au moment de formation de la première union stable et au moment de la première naissance. D'un autre côté, nous avons analysé la survie au début de la vie familiale des femmes nées hors de Catalogne, qui ont migré et qui n'avaient jamais été en union ni avaient pas eu d'enfants avant la migration. Nous avons aussi comparé les femmes qui sont venues en Catalogne provenant du reste de l'Espagne pendant la seconde moitié du xxème siècle avec celles arrivées de l'étranger au début du xxième siècle. Notre objectif est de déterminer s'il y a des éléments comuns ou divergents entre leurs modèles de primo-union et de primo-maternité