Encontrados 13 documentos, a visualizar página 1 de 2
Local residents’ attitudes towards the impact of tourism development in Cape Ve...
Sánchez Cañizares, Sandra María; University of Cordoba, Faculty of Economics, Department of Statistics, Business Organization and Applied EconomyThe attitudes and perceptions of local communities or residents are of special interest when examining and managing the economic, socio-cultural and environmental aspects of tourism development in a given area. In this paper, we analyse the perceptions and attitudes of residents in an emerging tourist destination: the island country of Cape Verde (Africa). A survey and multivariate analysis is used for the anal...
Parenting and Adolescents’ Self-Esteem: The Portuguese Context
Rodrigues, Yara; Veiga, Feliciano; Fuentes, María C.; García, FernandoThis study analyzes the relationships between parenting styles and adolescent’s psychosocial adjustment (self-esteem) in the Portuguese culture. The sample was of 517 adolescents, 214 males (41.39 %), and aged 11 to 18 years. We used the Parental Socialization Scale (ESPA29) to assess the parenting styles (authoritative, authoritarian, indulgent and negligent), and the Multidimensional Self-esteem Scale Form-5 ...
Using Light Scattering to Screen Polyelectrolytes (PEL) Performance in Floccula...
Rasteiro, Maria G.; Pinheiro, Ineide; Garcia, Fernando A. P.; Ferreira, Paulo; Hunkeler, DavidFlocculation of precipitated calcium carbonate (PCC) was monitored using light diffraction spectroscopy (LDS). Four cationic polyacrylamides of high molar mass and with different degrees of branching, all copolymers of acrylamide (AM) and acryloyloxyethyltrimethyl ammonium chloride (Q9), were tested. LDS supplied information about the kinetic curves for flocs growth and also for the flocs structure evolution. F...
Modeling the Turbulent Flow of Pulp Suspensions
Ventura, Carla A.F.; Garcia, Fernando A.P.; Ferreira, Paulo J.; Rasteiro, M. GraçaPulp fiber suspensions are complex systems because the components present singular and complex interactions between them. A mechanistic model for the turbulent flow regime of industrial pulp suspensions was developed on the basis of a CFD code, using the chemical engineering module of COMSOL Multiphysics software. The standard k-ε turbulence model, chosen to simulate turbulence, was tested and validated using f...
Escala de envolvimento dos alunos na escola: primeiros elementos da adaptação p...
Veiga, Feliciano; Pavlovic, Zoran; García, Fernando; Ochoa, MusituProcedeu-se neste estudo à adaptação da “Student Engagement in School Scale” (SES), de Lam & Jimerson (2008). A amostra envolveu 260 alunos de diferentes idades (X=13.78), do ensino básico (7º, 8,º e 9º anos), de 8 escolas de diferentes regiões do país (Aveiro, Lisboa, Évora e Ponta Delgada), com sujeitos do género masculino (42.1%) e feminino (57.9). A Escala apresentou bons índices de consistência interna e, ...
The Differentiation and Promotion of Students’ Rights in Portugal
Veiga, Feliciano; García, Fernando; Neto, Félix; Almeida, LeandroThis investigation includes a differential study (Study 1) and a quasi-experimental research (Study 2). In Study 1, the objective was to establish to what extent students’ rights existed and analyse the differentiation between students’ rights with Portuguese and immigrant mothers, throughout school years. The sample consisted of 537 students with Portuguese and immigrant mothers, distributed by different schoo...
Use of New Branched Cationic Polyacrylamides to Improve Retention and Drainage ...
Antunes, Elisabete; Garcia, Fernando A. P.; Ferreira, Paulo; Blanco, Angeles; Negro, Carlos; Rasteiro, M. GraçaCationic polyacrylamides of very high molecular weight and with different charge densities and degrees of branching have been investigated as retention aids for papermaking. The effects of polymer charge density and polymer branching on drainage and retention of a suspension containing fibers and precipitated calcium carbonate have been correlated with flocs properties. Additionally, the effects of flocculant d...
Flow dynamics of pulp fiber suspensions
Ventura, Carla; Garcia, Fernando; Ferreira, Paulo; Rasteiro, MariaThe transport between different equipment and unit operations plays an important role in pulp and paper mills because fiber suspensions differ from all other solid-liquid systems, due to the complex interactions between the different pulp and paper components. Poor understanding of the suspensions’ flow dynamics means the industrial equipment design is usually conservative and frequently oversized, thus contrib...
Effect of Water Cationic Content on flocculation, flocs resistance and refloccu...
Antunes, Elisabete; Garcia, Fernando A. P.; Ferreira, Paulo; Blanco, Angeles; Negro, Carlos; Rasteiro, M. GraçaIn papermaking, mill water closure may result in a significant increase of inorganic salts in the white water. The effect of these contaminants on the performance of retention aids was evaluated, in this study, through flocculation of Precipitated Calcium Carbonate (PCC) with three very high molecular weight cationic polyacrylamides (C-PAM) of medium charge density and with different degrees of branching. Furth...
Modeling pulp fiber suspension rheology
Ventura, Carla; Blanco, Angeles; Negro, Carlos; Ferreira, Paulo; Garcia, Fernando; Rasteiro, MariaRheological properties of pulp suspensions play a very important role in the industry, mainly due to the consumption of energy for transporting pulp among the different parts of the paper mill. In this work, we determined the rheology of long- and short-fiber bleached kraft pulp suspensions by using a new rotational viscometer especially designed for their analysis. The experimental rheograms were adjusted to t...
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