Assessment and application of clustering techniques to atmospheric particle number size distribution for the purpose of source apportionment

Long-term measurements of particle number size distribution (PNSD) produce a very large number of observations and their analysis requires an efficient approach in order to produce results in the least possible time and with maximum accuracy. Clustering techniques are a family of sophisticated methods which have been recently employed to analyse PNSD data, however, very little information is available comparing the performance of different clustering techniques on PNSD data. This study aims to apply several clustering techniques (i.e. K-means, PAM, CLARA and SOM) to PNSD data, in order to identify and apply the optimum technique to PNSD data measured at 25 sites across Brisbane, Australia. A new method, based on the Generalised Additive Model (GAM) with a basis of penalised B-splines, was proposed to parameterise the PNSD data and the temporal weight of each cluster was also estimated using the GAM. In addition, each cluster was associated with its possible source based on the results of this parameterisation, together with the characteristics of each cluster. The performances of four clustering techniques were compared using the Dunn index and Silhouette width validation values and the K-means technique was found to have the highest performance, with five clusters being the optimum. Therefore, five clusters were found within the data using the K-means technique. The diurnal occurrence of each cluster was used together with other air quality parameters, temporal trends and the physical properties of each cluster, in order to attribute each cluster to its source and origin. The five clusters were attributed to three major sources and origins, including regional background particles, photochemically induced nucleated particles and vehicle generated particles. Overall, clustering was found to be an effective technique for attributing each particle size spectra to its source and the GAM was suitable to parameterise the PNSD data. These two techniques can help researchers immensely in analysing PNSD data for characterisation and source apportionment purposes.

Energy transfer and infrared-to-visible upconversion luminescence of Er3+/Yb3+-codoped halide modified tellurite glasses

We report on the energy transfer and frequency upconversion spectroscopic properties of Er3+-doped and Er3+/Yb3+-codoped TeO2-ZnO-Na2O-PbCl2 halide modified tellurite glasses upon excitation with 808 and 978 nm laser diode. Three intense emissions centered at around 529, 546 and 657 nm, alongwith a very weak blue emission at 4 10 nm have clearly been observed for the Er3+/Yb3+-codoped halide modified tellurite glasses upon excitation at 978 nm and the involved mechanisms are explained. The quadratic dependence of fluorescence on excitation laser power confirms the fact that the two-photon contribute to the infrared to green-red upconversion emissions. And the blue upconversion at 410 nm involved a sequential three-photon absorption process. (c) 2005 Elsevier Ltd. All rights reserved.

Numerical analysis of LEC growth of GaAs with an axial magnetic field

A set of numerical analyses for momentum and heat transfer For a 3 in. (0.075 m) diameter Liquid Encapsulant Czochralski (LEC) growth of single-crystal GaAs with or without all axial magnetic field was carried Out using the finite-element method. The analyses assume a pseudosteady axisymmetric state with laminar floats. Convective and conductive heat transfers. radiative heat transfer between diffuse surfaces and the Navier-Stokes equations for both melt and encapsulant and electric current stream function equations Cor melt and crystal Lire considered together and solved simultaneously. The effect of the thickness of encapsulant. the imposed magnetic field strength as well as the rotation rate of crystal and crucible on the flow and heat transfer were investigated. (C) 2002 Published by Elsevier Science Ltd.

Autor filmowy według przepisów prawa w systemach droit d`auteur i copyright. Zarys problematyki

The aim of the article is to outline the key issues surrounding legal notions of film authorship. For scholars interested in studying the process of production it is extremely important to analyze the status and scope of power of its participants as well as their position in the hierarchy – one of the main sources of priveleges is the fact of being recognized by the law as the author of the work produced. The article depicts the benefits of such situation, but its main aim is to descibe the legal rules of granting the status of the author. Outlined are the issues emerged from the two radically different legal system – european droit d`auteur tradition and american copyright. The first one honours the artists while the other focuses mostly on providing the certainty of the economics, so the actual authors of the work are not that important. The paper points to the fact that – especially in the case of american copyright – the actual (determined by law) situation of a creator may differ significantly from the character of their contribution to the process of producing a film. Analysis of the rules and principles of the law is essential to the understanding of the structural determinants of film production and deserves no less attention than social, political and economic factors.

La vegetación de la clase Epilobietea angustifolii

Dentro de la vegetación de los claros de bosques húmedos (clase Epilobietea angustifolii) en los Pirineos catalanes distinguimos básicamente tres asociaciones: Epilobietum montani-angustifolii as. nova, ampliamente extendida por todo el territorio, aunque a menudo bastante pobre floristicamente; Atropetum belladonnae (Br.-Bl. 1930) Tx. 1950, más bien esporádica y a menudo fragmentaria, y Sambuco-Rubetum idaei O. de Bolós 1979, dentro del que se reconocen dos subasociaciones, rubetosum glandulosi (= typicum), limitada a los valles más occidentales y de carácter más o menos atlántico, y rubetosum idaei nova, de área más general y de ambientes relativamente secos.

Mitos de la selva y del desmonte: Shakaim

También este trabajo que entrego ahora a la imprenta no es perfecto y acabado en todos los detalles. Faltan los anent a Shakaim y una revisión cuidadosa de la grafía shuar. De todas maneras y a pesar de estas imperfecciones, prefiero que salga, para estimular la colaboración de los especialistas en la recolección e interpretación de datos de la cultura shuar. Shakáim, como lo afirman todos los ancianos shuar, es el mismo Etsa, Así llaman a Etsa cuando actúa en asuntos de agricultura y de vida familiar. La palabra Shakáim está compuesta de la onomatopeya '"shaká" que es el ruido que hace un fuerte chaparrón y de la palabra "yumi" que significa lluvia. Shakáim, por lo tanto, significa chaparrón, huracán. El chaparrón fecundiza la tierra y el huracán tumba los árboles gigantescos. Están relacionadas con este_nombre sea las relaciones matrimoniales, sea los trabajos de roce y tumbe. El misino mito habla de la llegada de Shakáim con el semblante de lluvia a la casa de Chuánk para sembrar las palmeras que proporcionan las hojas para el techo de la vivienda. Shakáim es el complemento de Nunkui. La figura de Nunkui es femenina porque se inspira en la tierra fecunda. La figura de Shakáim es masculina porque se inspira en la lluvia fecundizadora. Nunkui y Shakáim son el arquetipo de la pareja shuar. Si Nunkui enseña el trabajo a las mujeres, Shakáim enseña a los hombres. Shakáim ordena a los hombres los trabajos de roce y tala de la selva, la siembra del maíz al voléo, la construcción de la vivienda y la confección del vestido.

Velhice: Representações Sociais construídas por estudantes de enfermagem e idosos

A velhice enquanto fenómeno socialmente construído, deriva, entre outros, dos conceitos socioculturais vigentes e dos estereótipos do velho. Nos países ditos desenvolvidos consideram-se pessoas idosas as que têm idade igual ou superior a 65 anos, constituindo, em regra, a idade da reforma uma referência para a velhice (Spar e La Rue, 2005). Todavia, nestes países a idade da reforma tem vindo, nos tempos mais recentes, a ser aumentada. Como as representações sociais precisam de tempo para se adequarem às transformações que vão ocorrendo nas sociedades, ao continuarmos a utilizar conceitos como, atividade, reforma, velhice, podemos não nos aperceber que o seu conteúdo pode ter mudado. A Teoria das Representações Sociais é uma teoria científica sobre os processos através dos quais os indivíduos em interação social constroem explicações sobre objetos sociais (Vala, 1996). O uso desta teoria para o estudo de um objeto complexo, como o é a velhice, pode ser proveitoso, uma vez que permite apreender os sentidos que lhe são atribuídos pelos sujeitos que privam com o objeto e sobre o qual fazem recair ações e decisões (Tura, Silva, 2012). Partindo do pressuposto que a velhice poderá ser perspetivada de modo diferente por quem a vive e por quem a olha à distância, decidiu-se fazer um estudo com pessoas idosas e com jovens estudantes de enfermagem que se preparam para cuidar de pessoas entre as quais os idosos. Assim, com a finalidade contribuir para um maior esclarecimento acerca das representações sociais sobre a velhice, realizou-se o estudo, com os seguintes objetivos: - Identificar as representações sociais de velhice, construídas por estudantes e idosos. - Analisar a estrutura das representações sociais na perspetiva de estudantes e de idosos.

L'Écho de Paris

1917/03/08 (Numéro 11892).

Verdadera historia de los pontífices o sea refutación del cuadernoin titulado Despertador de las fanáticos. Estracto de los retratos de varios Papas

UANL

Étude rétrospective évaluant le VEGF comme biomarqueur d’athérosclérose mesurée par coronarographie quantitative et ultrason intra-vasculaire

Introduction : Puisque le VEGF promeut l’inflammation et la néovascularisation des plaques athérosclérotiques, il pourrait contribuer à l’athérogénèse. Cependant, les données cliniques tentant de lier le VEGF à la maladie cardiaque athérosclérotique (MCAS) sont controversées. Nous avons investigué l’association entre les niveaux de VEGF et la sévérité de la MCAS. Méthode : Nous avons effectué une étude rétrospective transversale : 56 patients présentant une MCAS stable et 112 patients avec un syndrome coronarien aigue (SCA) ont été étudiés. Nous avons investigué la relation entre la charge athérosclérotique et les niveaux sériques de VEGF en utilisant la coronarographie par analyse quantitative (QCA) et avons évalué la morphologie des plaques athérosclérotiques en utilisant l’imagerie intravasculaire ultrasonore (IVUS). Résultats : Les niveaux de VEGF étaient plus bas chez les patients avec SCA que chez ceux avec MCAS stable. On observe une corrélation positive entre les niveaux de VEGF et le fardeau de la MCAS stable mesurée par le QCA Cumulative Coronary Stenosis Score - CCSS (Pearson r= 0,423 et p = 0,001). En analyse multivariée, les niveaux sériques de VEGF demeuraient prédicteurs du CCSS (p=0,003) des patients avec une MCAS stable. Nous avons observé une corrélation positive entre les niveaux de VEGF et le volume de plaque (Spearman r = 0.381, p = 0.035) ainsi que le pourcentage de volume d’athérome (Spearman r = 0.466, p = 0.008) mesurés par IVUS. Conclusions : Notre étude suggère un usage potentiel des niveaux sérique de VEGF comme biomarqueur de MCAS.