Rocking behaviour of multi-block columns subjected to pulse-type ground motion accelerations

Ancient columns, made with a variety of materials such as marble, granite, stone or masonry are an important part of the
European cultural heritage. In particular columns of ancient temples in Greece and Sicily which support only the architrave are
characterized by small axial load values. This feature together with the slenderness typical of these structural members clearly
highlights as the evaluation of the rocking behaviour is a key aspect of their safety assessment and maintenance. It has to be noted
that the rocking response of rectangular cross-sectional columns modelled as monolithic rigid elements, has been widely investigated
since the first theoretical study carried out by Housner (1963). However, the assumption of monolithic member, although being
widely used and accepted for practical engineering applications, is not valid for more complex systems such as multi-block columns
made of stacked stone blocks, with or without mortar beds. In these cases, in fact, a correct analysis of the system should consider
rocking and sliding phenomena between the individual blocks of the structure. Due to the high non-linearity of the problem, the
evaluation of the dynamic behaviour of multi-block columns has been mostly studied in the literature using a numerical approach
such as the Discrete Element Method (DEM). This paper presents an introductory study about a proposed analytical-numerical
approach for analysing the rocking behaviour of multi-block columns subjected to a sine-pulse type ground motion. Based on the
approach proposed by Spanos (2001) for a system made of two rigid blocks, the Eulero-Lagrange method to obtain the motion
equations of the system is discussed and numerical applications are performed with case studies reported in the literature and with a
real acceleration record. The rocking response of single block and multi-block columns is compared and considerations are made
about the overturning conditions and on the effect of forcing function’s frequency.
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Synthesis of new vegetable oil-based polymeric materials

A crescente procura de recursos fosseis a que se tem assistido nos ultimos anos, tem resultado num crescimento sem precedentes dos precos, com consequencias imprevisiveis e que levara, no espaco de decadas, ao seu inevitavel esgotamento. A procura de um modelo de desenvolvimento sustentavel, baseado em recursos renovaveis e o grande desafio que se coloca a civilizacao no seculo XXI. A biomassa vegetal, atraves das designadas gBio-refinarias h, e uma alternativa logica para a producao de produtos quimicos e de materiais mas tambem de combustiveis e energia. Os oleos vegetais constituem uma das fracoes da biomassa vegetal, cuja exploracao tem merecido redobrada atencao nos ultimos anos, como fonte de materiais e de combustiveis. Assim, a presente dissertacao tem por objetivo o desenvolvimento de novos materiais polimericos derivados de oleos vegetais, seguindo duas abordagens distintas, nomeadamente a preparacao de polimeros atraves de polimerizacao por etapas e polimerizacao em cadeia (Parte B e C, respetivamente). Em primeiro lugar, foram sintetizados poliesteres alifaticos de cadeia longa a partir de monomeros provenientes do oleo de colza (Capitulo III). A auto-metatese do acido erucico com catalisadores de rutenio, seguida de hidrogenacao da ligacao dupla, originou o acido 1,26-hexacosanodioico, que por sua vez foi convertido em hexacosano-1,26-diol. Subsequentemente, a policondensacao do acido ƒ¿,ƒÖ-dicarboxilico de cadeia longa com o hexacosano-1,26-diol originou o poliester 26,26. O diacido C26 foi tambem polimerizado com outros alcano-diois de cadeia curta, nomeadamente o dodecano-1,12-diol e o butano-1,2-diol, produzindo, respetivamente, os poliesteres 12,26 e 4,26. Estes poliesteres de fontes 100% renovaveis possuem valores de Mn na ordem dos 8-14 kDa e valores de PDI entre 2.1 e 2.7. As propriedades destes poliesteres alifaticos foram avaliadas atraves de varias tecnicas, revelando elevada cristalinidade (com uma estrutura cristalina como a do polietileno) e elevadas temperaturas de fusao (74-104 ‹C), cristalizacao (68-92 ‹C) e degradacao (323-386 ‹C). Em segundo lugar, foram sintetizados polimeros lineares termo-reversiveis a partir de derivados do oleo de ricinio (Capitulo IV). Para tal foram preparados monomeros que incorporam aneis furanicos inseridos atraves do acoplamento tiol-eno, e que posteriormente foram polimerizados pela reacao de Diels-Alder (DA) entre os grupos furano (dieno A) e estruturas complementares do tipo maleimida (dienofilo B). Para as polimerizacoes DA foram consideradas duas abordagens diferentes, nomeadamente (i) o uso de monomeros com dois aneis furanicos terminais em conjunto com uma bismaleimida (sistemas AA+BB) e (ii) a utilizacao de um monomero que incorpora ambos os grupos reativos, furano e maleimida, na sua estrutura (sistema AB). Este estudo demonstrou claramente que ambas as estratégias foram bem sucedidas embora com diferentes resultados em termos da natureza dos produtos obtidos. Estes polímeros lineares apresentam valores relativamente baixos de Tg (-40 to -2 °C) devido à natureza flexível dos grupos separadores das funções reativas, e de Mn (4.5-9.0 kDa) dada a observada tendência de ciclização associada a concentrações baixas de monómero. A aplicação da reação de retro-DA aos polímeros em causa confirmou o seu caráter reversível, ou seja, a possibilidade de promover, em condições controladas, a despolimerização com recuperação dos monómeros de partida. Esta particularidade abre caminhos para materiais macromoleculares originais com aplicações promissoras tais como auto-reparação e reciclabilidade. Em terceiro lugar, sintetizaram-se polímeros não-lineares termo-reversíveis a partir de derivados do óleo de ricínio (Capítulo V). Para tal foram preparados monómeros trifuncionais e posteriormente polimerizados através da reação de DA entre os grupos reativos complementares furano/maleimida. Foram consideradas três abordagens distintas para preparar estes polímeros não-lineares, nomeadamente através da utilização de (i) um monómero bisfurânico em combinação com uma trismaleimida (sistema A2+B3) e (ii) um monómero trisfurânico em conjunto com uma bismaleimida (sistema A3+B2) que originaram materiais ramificados ou reticulados, e ainda (iii) a utilização de monómeros assimetricamente substituídos do tipo A2B ou AB2 capazes de originar estruturas macromoleculares hiper-ramificadas. Todos os sistemas apresentaram valores de Tg perto de 0 °C, o que era de esperar para estes materiais não-lineares. A aplicação da reação de retro-DA comprovou mais uma vez o caráter termo-reversível das polimerizações em causa. Em quarto lugar e último lugar, foram preparados copolímeros de acetato de vinilo (VAc) com monómeros derivados de óleo de girassol (Capítulo VI). Ésteres vinílicos de ácidos gordos (FAVE) foram sintetizados por transvinilação dos ácidos oleico e linoleico com VAc catalisada por um complexo de irídio. Os monómeros vinílicos preparados foram caracterizados e posteriormente homopolimerizados e copolimerizados com VAc através do uso dos grupos vinílicos terminais como função inicial de polimerização. A variação do tipo e quantidade de monómero FAVE e da quantidade de iniciador radicalar originou copolímeros de VAc com valores de Mn na gama de 1.2-3.0 kDa e valores de Tg de -5 a 16 °C. Os copolímeros foram avaliados em testes de cura oxidativa através das insaturações nas suas cadeias alifáticas para formar materiais reticulados, e os resultados sugerem que eles podem ser sistemas efetivos de cura para aplicações como tintas, vernizes e outros tipos de revestimento. Todos os materiais poliméricos preparados ao longo deste trabalho constituem contribuições atrativas para a área dos polímeros oriundos de recursos renováveis e representam uma prova indiscutível de que os óleos vegetais são percursores promissores de materiais macromoleculares com potenciais aplicações.

Impact of exercise training on cancer-induced cardiac dysfunction

Cachexia is a complex syndrome characterized by severe weight loss frequently observed in cancer patients and associated with poor prognosis. Cancer cachexia is also related to modifications in cardiac muscle structure and metabolism leading to cardiac dysfunction. In order to better understand the cardiac remodeling induced by bladder cancer and the impact of exercise training after diagnosis on its regulation, we used an animal model of bladder cancer induced by exposition to N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) in the drinking water. Healthy animals and previously BBN exposed animals were submitted to a training program in a treadmill at a speed of 20m/min, 60 min/day, 5 days/week during 13 weeks. At the end of the protocol, animals exposed to BBN presented a significant decrease of body weight, in comparison with control groups, supporting the presence of cancer cachexia. Morphological analysis of the cardiac muscle sections revealed the presence of fibrosis and a significant decrease of cardiomyocyte’s cross-sectional area, suggesting the occurrence of cardiac dysfunction associated with bladder cancer. These modifications were accompanied by heart metabolic remodeling characterized by a decreased fatty acid oxidation given by diminished levels of ETFDH and of complex II subunit  from the respiratory chain. Exercise training promoted an increment of connexin 43, a protein involved in cardioprotection, and of c-kit, a protein present in cardiac stem cells. These results suggest an improved heart regenerative capacity induced by exercise training. In conclusion, endurance training seems an attractive non-pharmacological therapeutic option for the management of cardiac dysfunction in cancer cachexia.

Developmental Antecedents of Proactive and Reactive Rebelliousness: The Role of Parenting Style, Childhood Adversity, and Attachment

Adolescence is a time of developmental transition that for one in five young people is characterised by feelings of oppositionality, rebellion, and negativism. Despite the prevalent experience of teen turbulence and despite its significance within the phenomenological framework provided by reversal theory (RT), the childhood antecedents of rebelliousness in adolescence and adulthood have not been given extensive empirical attention within RT, although such work has been carried out using other constructs and theories. We examined recalled parenting style, childhood adversity, and attachment style in adulthood as correlates of proactive and reactive rebelliousness in a sample of 80 participants, aged 18 to 50 years. Each participant responded to a questionnaire package containing the revised Adult Attachment Scale, the Parental Bonding Instrument, the Childhood Experience of Care and Abuse Questionnaire, and the Negativism Dominance Scale. We found that paternal abusive parenting, followed by paternal parenting style, paternal neglect, and paternal antipathy were independently predictive of scores on proactive rebelliousness, the sensation-seeking form. Maternal and paternal indifferent parenting styles each were found to equivalently and independently predict scores on reactive rebelliousness, the interpersonal disaffection form. The results of this study suggest these two forms of rebelliousness may have distinctly different antecedents. A longitudinal study is needed to examine the potentially causal pathways that are suggested by the results of this cross-sectional research. We consider reversal theory explanations of these results and contrast them with complementary theoretical frameworks.

QoS improvement in TCP/IP-based wireless sensor networks using cross-layer optimization

Dissertação de Mestrado, Engenharia Informática, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

Adaptive compensation of analog front-end I/Q mismatches in digital receivers

I and Q Channel phase and gain misniatches are of great concern in communications receiver design. In this paper we analyse the effects of I and Q channel mismatches and propose a low-complexity blind adaptive algorithm to minimize this problem. The proposed solution consists of two, 2-tap adaptive filters, arranged in Adaptive Noise Canceller (ANC) set-up, with the output of one cross-fed to the input of the other. The system works as a de-correlator eliminating I and Q mismatch errors.

Job-demand for Learning and Job-related Learning: The Moderating Effect of Need For Achievement

Purpose – The purpose of the research is to examine whether need for achievement moderates the relationship between job-demand for learning and job-related learning. Design/methodology/approach – Data were obtained from 153 participants full-time. The scales for job-demand for learning and job-related learning were developed for this research, whilst the scale for need for achievement was obtained from an external source. Hierarchical regression analysis was used in testing the hypothesized moderating effects. Findings – It was found that need for achievement moderates the relationship between job-demand for learning and job-related learning. Specifically, although job-demand for learning is correlated positively to job-related learning for both the high and the low need for achievement groups, this correlation is stronger amongst the high group. Research limitations/implications – The use of a cross-sectional design in this study prohibits inferences being drawn regarding the causal relationships between job-demand for learning, need for achievement and job-related learning. Practical implications – Job-related learning can be facilitated through increasing the need for achievement by allowing employees to establish their own learning and performance goals rather than by imposing such goals on them. The redesign of jobs to create challenges for employees is an equally important practical consideration. Originality/value – This research provides a succinct view of the relationship between an external factor, job-demand for learning, and an internal motivator, need for achievement. It emphasizes the degree to which organizations can facilitate learning through design of challenging jobs, to the extent of the individuals’ motivation.

Essays on Applications of the Factor Model

Thesis (Ph.D.)--University of Washington, 2013

Gentrifying the Peri-urban: Land use Conflicts and institutional dynamics at the Frontier of an Indonesian Metropolis

This paper aims to specify the meaning of gentrification in rapidly peri-urbanising metropolitan regions in the context of Indonesia’s rapid transition to decentralisation and democracy. It discusses a case study of conflict over an environmental revitalisation project in a peri-urban area of Bandung City. The analysis focuses on the political processes, tactics and strategies supporting and opposing peri-urban gentrification and their consequences. The analysis illustrates how these political dynamics mediate the interaction between the movement of capital and the spatial reorganisation of social classes. It is argued that in the context of a peri-urbanising metropolis, gentrification needs to be narrated less in terms of class-based neighbourhood succession and more in terms of competing cross-class coalitions emerging at local and regional levels.

Landscapes of the invisible: sounds, cosmologies and poetics of space

In this PhD by Publication I revisit and contextualize art works and essays I have collaboratively created under the name Flow Motion between 2004-13, in order to generate new insights on the contributions they have made to diverse and emerging fields of contemporary arts practice/research, including digital, virtual, sonic and interdisciplinary art. The works discussed comprise the digital multimedia installation and sound art performance Astro Black Morphologies/Astro Dub Morphologies (2004-5), the sound installation and performance Invisible (2006-7), the web art archive and performance presentation project promised lands (2008-10), and two related texts, Astro Black Morphologies: Music and Science Lovers (2004) and Music and Migration (2013). I show how these works map new thematic constellations around questions of space and diaspora, music and cosmology, invisibility and spectrality, the body and perception. I also show how the works generate new connections between and across contemporary avant-garde, experimental and popular music, and visual art and cinema traditions. I describe the methodological design, approaches and processes through which the works were produced, with an emphasis on transversality, deconstruction and contemporary black music forms as key tools in my collaborative artistic and textual practice. I discuss how, through the development of methods of data translation and transformation, and distinctive visual approaches for the re-elaboration of archival material, the works produced multiple readings of scientific narratives, digital X-ray data derived from astronomical research on black holes and dark energy, and musical, photographic and textual material related to historical and contemporary accounts of migration. I also elaborate on the relation between difference and repetition, the concepts of multiplicity and translation, and the processes of collective creation which characterize my/Flow Motion’s work. The art works and essays I engage with in this commentary produce an idea of contemporary art as the result of a fluid, open and mutating assemblage of diverse and hybrid methods and mediums, and as an embodiment of a cross-cultural, transversal and transdisciplinary knowledge shaped by research, process, creative dialogues, collaborative practice and collective signature.

Growth and characterization of Cu2ZnSn(S,Se)4 thin films for solar cells

Cu2ZnSnS4 (CZTS) and Cu2ZnSnSe4 (CZTSe) with their band gap energies around 1.45 eV and 1.0 eV, respectively, can be used as the absorber layer in thin film solar cells. By using a mixture of both compounds, Cu2ZnSn(S,Se)4 (CZTSSe), a band gap tuning may be possible. The latter material has already shown promising results such as solar cell efficiencies up to 10.1%. In this work, CZTSSe thin films were grown in order to study its structure and to establish the best growth precursors. SEM micrographs reveal an open columnar structure for most samples and EDS composition profiling of the cross sections show different selenium gradients. X-ray diffractograms show different shifts of the kesterite/stannite (1 1 2) peak, which indicate the presence of CZTSSe. From Raman scattering analysis, it was concluded that all samples had traces of CZTS and CZTSSe. The composition of the CZTSSe layer was estimated using X-ray diffraction and Raman scattering and both results were compared. It was concluded that Se diffused more easily in precursors with ternary Cu–Sn–S phases and metallic Zn than in precursors with ZnS and/or CZTS already formed. It was also showed that a combination of X-ray diffraction and Raman scattering can be used to estimate the ratio of S per Se in CZTSSe samples.

Rat muscle opacity decrease due to the osmosis of a simple mixture

It is known that the fibrous structure of muscle causes light scattering. This phenomenon occurs due to the refractive index discontinuities located between muscle fibers and interstitial fluid. To study the possibility of reducing light scattering inside muscle, we consider its spectral transmittance evolution during an immersion treatment with an optical clearing solution containing ethanol, glycerol, and distilled water. Our methodology consists of registering spectral transmittance of muscle samples while immersed in that solution. With the spectral data collected, we represent the transmittance evolution for some wavelengths during the treatment applied. Additionally, we study the variations that the treatment has caused on the samples regarding tissue refractive index and mass. By analyzing microscopic photographs of tissue cross section, we can also verify changes in the internal arrangement of muscle fibers caused by the immersion treatment. Due to a mathematical model that we develop, we can explain the variations observed in the studied parameters and estimate the amount of optical clearing agent that has diffused into the tissue samples during the immersion treatment. At the end of the study, we observe and explain the improvement in tissue spectral transmittance, which is approximately 65% after 20 min.

Barreiras e estímulos ao aleitamento materno exclusivo na Província do Uíge, Angola

RESUMO - É recomendado o aleitamento materno exclusivo desde o nascimento até aos 6 meses. Angola apresenta uma situação bastante preocupante, pois é um dos países do mundo com maior taxa de mortalidade infantil: em 2010 era de 114,9 mortes por cada 1000 nascimentos. O desmame precoce, a contaminação dos alimentos e da água potável e a desnutrição criam condições para aparecimento de doenças que causam elevadas mortes em crianças com menos de um ano. Em muitas regiões de África, o parto ainda é um acontecimento marcado por práticas culturais ancestrais que podem prejudicar a saúde e sobrevivência dos recém-nascidos, além de pôr em perigo a vida das mães. Algumas dessas práticas incluem: (i) deitar fora o colostro; e (ii) alimentar os bebés com outros alimentos que não o leite materno. Este estudo é quantitativo com metodologia transversal e pretende identificar, descrever e analisar os fatores que contribuem para o abandono do aleitamento materno exclusivo antes dos 6 meses de idade, na província do Uíge, em Angola, bem como indicar formas de intervenção para que os índices de prevalência do aleitamento materno exclusivo possam aumentar. A população em estudo são mães com filhos até um ano de idade e utilizadoras do centro de saúde materno infantil do município sede da província de Uíge em Angola, da qual será considerada uma amostra de 418 mães. Os dados obtidos através de questionário serão registados em quadros e gráficos para posterior análise estatística através de tabelas de frequências, cálculo de percentagens e taxas de incidência.

Assessing performance drivers in cross-border M&A

This research is an investigation on the deal-specific factors impacting long-term performance of cross-border M&A and on the nature of such relations. The analysis is conducted on a sample of 187 cross-border deals completed within the pharmaceutical and biotech industries by Western European bidders between 2000 and 2009. Findings suggest that post-deal variation in gross profit improves when bidders diversify in other businesses, when assets are purchased instead of equity, and when stock is used as deal currency. Furthermore, the method of payment is found to moderate the effects geographical distance has on deal outcomes.

Facilitating coordination improvement efforts in cross-functional process development programs

Business process improvement is a common approach in increasing the effectiveness of an organization. It can be seen as an effort to increase coordination between units. Process improvement has proved to be challenging, and most management consultation firms facilitate organizations in this kind of initiatives. Cross-functional improvement is one of the main areas for internal consultants as well. However, the needs, challenges and means of cross-functional help have been rarely discussed in the literature. The objective of this thesis is on one hand to present a conceptual and descriptive framework to help understand the challenges of facilitating coordination improvement efforts in cross-functional improvement programs, and on the other hand to develop and test feasible solutions for some facilitation situations. The research questions are: 1. Why and in what kind of situations do organizations need help in developing coordination in cross-functional processes? 2. How can a facilitator help organizations in improving coordination to develop cross-functional processes? The study consists of two parts. The first part is an overview of the dissertation, and the second part comprises six research publications. The theoretical background for the study are the differentiation causing challenges in cross-functional settings, the coordination needed to improve processes, change management principles, methods and tools, and consultation practises. Three of the publications introduce tools for helping in developing prerequisites, planning responsibilities and supporting learning during the cross-functional program. The three other papers present frameworks to help understand and analyse the improvement situation. The main methodological approaches used in this study are design science research, action research and case research. The research data has been collected from ten cases representing different kinds of organizations, processes and developing situations. The data has been collected mainly by observation, semi-structured interviews and questionnaires. The research contributes to the rare literature combining coordination theories and process improvement practises. It also provides additional understanding of a holistic point of view in process improvement situations. The most important contribution is the addition to the theories of facilitating change in process improvement situations. From the managerial point of view, this study gives advice to managers and consultants in planning and executing cross-functional programs. The main factors increasing the need for facilitation are the challenges for differentiation, challenges of organizational change in general, and the novelty of initiatives and improvement practices concerning process development. Organizations need help in creating the prerequisites to change, in planning initiatives, easing conflict management and collaboration between groups, as well as supporting the learning of cross-functional improvement. The main challenges of facilitation are combining the different roles as a consultant, maintaining the ownership for the improvement project with the client, and supporting learning in the client organization.