1,225 research outputs found
Numerical modelling of the time dependent behaviour of clays
In the last two decades extensive research has been undertaken to characterize the time and rate dependent response of soils and to describe it by means of a constitutive model. However, most of these constitutive equations have been dev.eloped for a single stress point and limited stress paths, and in engineering practice the time, dependent nature of soils is still commonly reduced to a single coefficient of secondary consolidation obtained from a 24h oedometer test. J This thesis describes the development and implementation, in the Imperial College Finite Element Program (I~FEP), of two elastic visco-plastic models based on the overstress theory to describe the stress-strain-time/rate behaviour of clayey soils. The models differ essentially in the adopted law to describe the variation of the creep ~ deformation with time. The fIrst model - Creep Model 1 - incorporates a linear logarithmic law to describe the variation ofthe creep defon:nation with time, while the second model- Equivalent Time (ET) Model - incorporates a non-linear logarithmic creep law, with a limit to the amount of volumetric creep strain that can occur. The implementation and performance of the models is validated through a series of simple fInite element analyses that mimic common l~boratory stress paths and show that the models are able to reproduce the' phenomena of primary and secondary compression, stress relaxation, primary and secondary creep and persistent rate effects on the stress-strain .response under Ko and triaxial stress conditions. The ET model is then used to investigate the increase in bearing capacity of preloaded footings on soft clay, taking into account both the effects of consolidation and soil hardening due to creep with time. Finally, a series of fInite element analyses are presented that mimic the loading tests performed on two instrumented rigid footings at the Bothkennar test site. These analyses highlight the importance of considering the soil viscous effects in engineering practice and the need to account for the soil creep non-linearity if good predictions of the long-term settlements of geotechnical structures are to be made.Imperial Users onl
The Integration Processes of Migrants and Refugees in Germany
In dieser Dissertation untersuche ich verschiedene Aspekte des Integrationsprozesses von Migranten und Flüchtlingen, insbesondere wie sich ihre Präsenz auf die Protestaktivitäten und Einstellungen von Einheimischen auswirkt. Die vier Kapitel bauen auf der bestehenden Literatur auf und zielen darauf ab, diese in mehreren Aspekten zu ergänzen. Das erste und das zweite Kapitel verbessern unser Verständnis der kausalen Auswirkungen der Bedingungen im Heimatland auf die Rückkehrabsichten und die Arbeitsmarktintegration von Migranten im Zielland sowie das Verständnis der Auswirkungen traumatischer Erfahrungen während der Flucht auf die Arbeitsmarktintegration von Flüchtlingen. Das dritte Kapitel befasst sich mit der soziokulturellen Integration von Familienmigranten in einem Land, das nicht ihre erste Wahl darstellt. Das vierte Kapitel untersucht die Auswirkungen der Anwesenheit von Ausländern auf die Protestaktivität einer bestimmten Gruppe von Einheimischen und wie sich diese Proteste auf die Besorgnis über Fremdenfeindlichkeit und Intoleranz auf nationaler Ebene auswirken. Die Ergebnisse der Dissertation sollen die politischen Entscheidungsträger über die potenziellen Nebenwirkungen der Migrationspolitik informieren und empirische Erkenntnisse liefern, die zur Verbesserung bestehender und zur besseren Gestaltung künftiger politischer Maßnahmen beitragen.In this PhD thesis, I look at different aspects of the integration process of migrants and refugees, and how their presence affects the protest activity and attitudes of natives. The four chapters build on and aim to extend the existing literature along several dimensions. The first and second chapters improve our understanding of the causal effect of home country conditions on migrants' return intentions and labour market outcomes at destination and of the effect of traumatizing experiences along the journey on refugees' labour market integration. The third chapter explores the socio-cultural integration of family migrants in a country that was not their primary choice, while the fourth chapter examines the effect of the presence of foreigners on the protest activity of a particular group of natives and how these protests affect worries about xenophobia and intolerance at the national level. The findings in the dissertation aim to inform policymakers on the potential side-effect of migration policies and to provide empirical evidence that help improve existing policies and better design future ones.eral dimensions
The relevance of microcredit and its impact om East Timor MSEs and proverty reduction
Microcredit has an important role in the growth and productivity of the micro, small and
medium enterprises (MSMEs) in East Timor, also on poverty reduction in other countries. The
objective of this thesis, comprised of four essays, is to provide empirical evidence of the impact
of microcredit on the growth and productivity of MSEs and poverty reduction of a selected set
of specific factors. As microcredit is still a relevant issue of concern for some countries, due to
their considerable role and functions for the growth and productivity of MSEs, the first paper
performs an empirical analysis of MSEs data obtained with the application of a questionnaire in
Dili, East Timor. The second paper examines the impact of microcredit on MSEs growth in Dili,
East Timor, controlling for MSE age and size, micro saving and also for the firms' activity sector,
firm’s investment type and the gender of the owner/manager of the firm, with 1-year data. The
third paper examines the impact of microcredit on the productivity (measured by single factor
productivity (SFP), total factor productivity (TFP) and labor productivity (LP)) of MSEs in East
Timor, with 1-year data. Lastly, the fourth paper examines the impact of microcredit, job
creation, inflation rates and education on poverty reduction, controlling for income and its
distribution, in East Timor, Bangladesh, Indonesia, Philippines, Myanmar, Cambodia, Pakistan,
Malaysia, Thailand, Nepal, and Srilanka, with data from 2007-2016.
The results obtained suggest that: (i) the microcredit had a significant contribution on the
growth and productivity of MSEs; (ii) the microcredit had positive impact on the growth of MSEs;
(iii) the microcredit had a positive impact on MSEs productivity; and (iv) microcredit had a
significant impact on the poverty reduction; Resumo:
O microcrédito tem um papel importante no crescimento e produtividade das micro e
pequenas empresas (MPEs), contribuíndo para a redução da pobreza em Timor-Leste tal como
acontece em muitos outros países. O objetivo desta tese, composta por quatro artigos
científicos, é fornecer evidências empíricas do impacto do microcrédito no crescimento e
produtividade das MPEs e redução da pobreza, de um conjunto selecionado de factores
específicos. Continuando o microcrédito a ser um fator relevante para alguns países devido ao
seu papel e funções consideráveis no crescimento e produtividade das MPE, fizemos em
primeiro lugar uma análise da evidência empírica do microcrédito nas MPE de Timor-Leste, com
dados de 1 ano, obtidos com o recurso a um questionário. O segundo artigo analisa o impacto
do microcrédito no crescimento das MPE em Díli, Timor-Leste, tendo em conta a idade e
dimensão das MPE, a micro poupança e, também, o sector de actividade das empresas, o tipo
de investimento das empresas e o género do proprietário/gestor da empresa, também com
dados de 1 ano. O terceiro artigo examina o impacto do microcrédito na produtividade (medida
pela produtividade de fator único (SFP), produtividade total dos fatores (TFP) e produtividade
do trabalho (LP)) das MPEs em Timor-Leste, ainda com dados de 1 ano. Por último, o quarto
artigo examina o impacto do microcrédito, criação de emprego, taxas de inflação, relação entre
educação e redução da pobreza, contorlando a obtenção de rendimento e sua distribuição, em
Timor-Leste, Bangladesh, Indonésia, Filipinas, Myanmar, Camboja, Paquistão, Malásia,
Tailândia, Nepal e Srilanka, com dados para o período 2007-2016.
Os resultados obtidos sugerem que: (i) o microcrédito teve uma contribuição significativa no
crescimento e produtividade das MPE; (ii) o microcrédito teve impacto positivo no crescimento
das MPE; (iii) o microcrédito teve um impacto positivo na produtividade das MPE; e (iv) o
microcrédito teve um impacto significativo na redução da pobreza
Atualização do Programa Nacional de Vacinação: PNV 2017
Desde a sua criação em 1965, o panorama epidemiológico das doenças evitáveis por vacinação em Portugal era desfavorável em relação aos outros países da Europa. Assim, com o objetivo de prevenir a ocorrência de determinadas doenças infeciosas, foi criado o Programa Nacional
de Vacinação para vacinar a população, especialmente as crianças, de forma organizada, universal, gratuita e com continuidade.
Desde 1965, o PNV foi sendo atualizado em duas vertentes principais:
• Introdução progressiva de vacinas, determinada por fatores epidemiológicos e pela disponibilidade de novas e melhores vacinas.
• Atualização dos esquemas vacinais para melhor adaptação à realidade epidemiológica e adesão ao PNV.
Ao longo da sua evolução, foram realizadas cinco campanhas de vacinação de larga escala, complementares ao PNV, com o objetivo de controlar/eliminar as doenças alvo mais rapidamente. Quando se justifica, são também realizadas campanhas de vacinação pontuais, aplicadas a grupos específicos ou em circunstâncias especiais.info:eu-repo/semantics/publishedVersio
Portuguese validation of the climate change attitude survey: psychometric properties and relations with positive youth development
Promoting positive development may lead to young people’s active contribu tions to their environment through positive attitudes and behaviours. The Climate Change Attitude Survey (15-item version) aims to identify climate
change attitudes differences in groups of students and to assess pre- to postintervention attitude changes. We intended to validate and test a possible extension of this scale among a Portuguese sample of adolescents and emerging adults. We also investigated whether higher scores on this scale would be positively associated with positive youth development. Exploratory and confirmatory factor analysis, measurement invariance, and convergent validity were assessed. The results showed good psychometric properties aligned with the original factorial structure. Significant differences were found among female and male samples regarding beliefs and intentions. A small but significant positive association was identified with a positive youth development scale. We suggest this may be an adequate instrument to assess youth climate change beliefs and intentions.This study was conducted at the Psychology Research Centre (PSI/01662), School of Psychology, University of Minho, supported by the Foundation for Science and Technology (FCT) through the Portuguese State Budget (UIDB/PSI/01662/2020), and under a Ph.D. fellowship also supported by FCT (SFRH/BD/143814/2019)
Medidas de poluentes metálicos em solos e espécies vegetais de hortas urbanas
Nos últimos anos, o número de hortas urbanas tem vindo a sofrer um acréscimo significativo. Com o apoio das Câmaras Municipais, uma faixa de população mais carenciada cultiva diferentes espécies vegetais que posteriormente, são consumidas pelos próprios ou vendidas a terceiros. A localização destas hortas junto de vias rodoviárias de elevada intensidade de tráfego automóvel levou, porém, a uma preocupação generalizada com a qualidade destes alimentos e com o seu efeito obre a saúde pública.
Este trabalho centrou-se na quantificação de metais pesados (Pb, Ni, Cr e Cd) depositados e absorvidos, em duas espécies vegetais (alface e couve-galega) e nos solos destas culturas. As amostras foram submetidas a digestão húmida em banho de areia, para degradação da matriz e os metais foram quantificados utilizando um equipamento de absorção atómica em Câmara de grafite (GFAAS). Foi realizada uma caracterização dos solos, de forma a verificar a influência de alguns parâmetros na acumulação das espécies metálicas pelos próprios solos e na sua absorção por parte das espécies vegetais em estudo.
As amostras foram recolhidas junto à Auto-estrada de Cascais (A5C), Circular Regional Interna de Lisboa (CRIL), 2ª Circular (2C), Itinerário Complementar 19 (IC19), ISEL (ISELAPT), Montijo (PVGEV), Belém (BE) e Calçada de Carriche (OB).
Em termos de metais pesados, verificou-se que todos os solos que apresentam maior teor em chumbo são os de Belém e 2ª Circular. Para os restantes metais, as amostras que apresentam teores mais elevados são as das vias onde se verifica uma grande acumulação de tráfego (Belém; CRIL; A5; IC19; Olival Basto). Verificou-se também que, nestes casos, os valores de pH se encontram entre 7.77 e 8.76; os valores da matéria orgânica, se situam entre 13.61% e 4.27% e a percentagem de água entre 14.97% e 7.48%.
Nas amostras de alface, a que apresentou um maior teor em chumbo foi a de Olival Basto. A amostra de alface recolhida junto ao ISEL apresenta o maior teor em níquel e em cádmio. O crómio é superior nas alfaces recolhidas na horta junto à Ponte Vasco da Gama.
Nas amostras de couve-galega, a que apresentou um teor mais elevado em chumbo foi a do Olival Basto, enquanto para os restantes metais, e tal como verificado para as amostras de solo, são as das hortas junto às vias de grande acumulação de tráfego as qu apresentam maiores teores.
Este trabalho permitiu identificar em que casos os teores estabelecidos pela legislação Europeia eram ultrapassados, podendo a eventual ingestão das espécies vegetais em estudo provocar um efeito negativo sobre a saúde humana
Indoor environmental quality assessment in groceries
Mestrado em Segurança e Higiene no TrabalhoAir is among the vital human needs to survive. It is the one thing humans cannot be without for longer than a few minutes. Indoor Air Quality (IAQ) is a public and occupational health concern since we are exposed to air pollutants daily, given that we spend almost 90% of our time in indoor environments. IAQ can be affected by numerous factors, from outdoor pollutants that get indoors through ventilation to building materials, furnishing, and activities carried by the building occupants. Exposure to air pollutants has been linked to a panoply of adverse effects on our health, well-being, and performance. The aim of this study was to assess the IAQ in grocery stores (GS) in the municipality of Cascais in the Lisbon district of Portugal, and, consequently, to characterize the workers' occupational exposure to air pollutants. The study was conducted in 13 small “family” grocery stores. The IAQ monitoring campaign was conducted using low-cost technologies and focused on several parameters, namely: Carbon dioxide (CO2), Volatile organic compound (VOCs), Particulate matter (PM10 and PM2.5), Temperature (T), and Relative Humidity (RH). The results were analyzed using SPSS software. Overall, the IAQ of the studied GSs complied with the Portuguese legislation, except for PM2.5, where 23% of GSs presented levels above the established limit value of 25 μg.m-3. The IAQ assessment allowed us to identify the best strategies to improve the workers’ experience in indoor environments at their workplaces.N/
Barriers to humanitarian migration, victimisation and integration outcomes: evidence from Germany
In this paper, we link the peril of asylum seekers’ migratory journey to economically quantifiable outcomes in the destination country using refugee survey data from Germany collected in the aftermath of the 2015 refugee crisis. We start by showing that, accounting for selection effects, physical victimisation during the journey to Germany is strongly associated with significantly lower mental well-being and general health upon arrival in the destination. The physical victimisation experience severely distorts the human capital investment decision by leading affected refugees to favour joining the labour force and engaging in part-time and marginal employment over pursuing host-country education. We place our findings into both the psychiatric and experimental economic literature, which suggest that experiencing physical trauma in vulnerable situations results in a "loss of future directedness" or "impatience" among the victimised, leading them to discount future payoffs more heavily
Local far-right demonstrations and nationwide public attitudes toward migration
One of the primary objectives of protests and demonstrations is to bring social, political,
or economic issues to the attention of politicians and the wider population. While protests
can have a mobilizing and persuading effect, they may reduce support for their cause if they
are perceived as a threat to public order. In this study, we look at how local or spontaneously
organised xenophobic demonstrations affect concerns about hostility towards foreigners and
worries about immigration among natives in Germany. We use a regression discontinuity
design to compare the attitudes of individuals interviewed in the days immediately before a
large far-right demonstration and individuals interviewed in the days immediately after that
demonstration. Our results show that large right-wing demonstrations lead to a substantial
increase in worries about hostility towards foreigners of 13.7% of a standard deviation. In
contrast, worries about immigration are not affected by the demonstrations, indicating that
the protesters are not successful in swaying public opinion in their favour. In the heterogeneity
analyses, we uncover some polarisation in the population: While worries about hostility against
foreigners increase and worries about immigration decrease in left-leaning regions, both types
of worries increase in districts where centre-right parties are more successful. Lastly, we also
show that people become more politically interested in response to protests, mainly benefiting
left-wing parties, and are more likely to wish to donate money to help refugees
Social Analysis Proposal for Advertising in the Context of Organizational"
Este trabalho tem como objetivo discutir métodos de análise social empírica e propor um modelo aplicado aos estudos de identidade de marca e da publicidade no contexto da Comunicação Organizacional. O nosso ponto de partida surgiu em torno da questão: como pode a identidade da organização ser transmitida por meio da publicidade? Para resolver esta equação, enfatizamos a importância de uma fase teórica exploratória, que discute pressupostos e orientações ideológicas, modelos e conceitos para enquadrar o problema. Entretanto nossa contribuição centra-se numa proposta de modelo empírico, que assenta numa metodologia rigorosa e sistemática, a partir de métodos e técnicas confluentes com os objetivos da investigação.This paper has the objective of discussing empirical social analysis methods and propose an applied model to the studies of brand identity and advertising in the context of Organizational Communication. Our starting point was the question: how can the identity of the organization be transmitted through advertisement? To answer this equation, we emphasized the importance of an exploratory theoretical phase, that discusses presupposition and ideological orientations, models and concepts to frame the issue. However our contribution is centered on a proposal of empirical study, based on a rigorous and systematic methodology, with methods and techniques that are pertinent to the objectives of the investigation.Fundação para a Ciência e a Tecnologia (FCT
- …