Novel Photochemical Methodologies For Diversity Oriented Synthesis And Screening Of Combinatorial Libraries

The main goal of this project was to develop an efficient methodology allowing rapid access to structurally diverse scaffolds decorated with various functional groups. Initially, we discovered and subsequently developed an experimentally straightforward, high-yielding photoinduced conversion of readily accessible diverse starting materials into polycyclic aldehydes and their (hemi)acetals decorated by various pendants. The two step sequence, involving the Diels-Alder addition of heterocyclic chalcones and other benzoyl ethylenes to a variety of dienes, followed by the Paternò-Büchi reaction, was described as an alkene-carbonyl oxametathesis. This methodology offers a rapid increase in molecular complexity and diversity of the target scaffolds. To develop this novel methodology further and explore its generality, we directed our attention to the Diels-Alder adducts based on various chromones. We discovered that the Diels-Alder adducts of chromones are capable of photoinduced alkene-arene [2+2] cycloaddition producing different dienes, which can either dimerize or be introduced into a double-tandem [4π+2π]·[2π+2π]·[4π+2π]·[2π+2π] synthetic sequence, followed by an acid-catalyzed oxametathesis, leading to a rapid expansion of molecular complexity over a few experimentally simple steps. In view of the fact that oxametathesis previously was primarily observed in aromatic oxetanes, we decided to prepare model aliphatic oxetanes with a conformationally unconstrained or "flexible" methyl group based on the Diels-Alder adducts of cyclohexadiene or cyclopentadiene with methyl vinyl ketone. Upon addition of an acid, the expected oxametathesis occurred with results similar to those observed in the aromatic series proving the generality of this approach. Also we synthesized polycyclic oxetanes resulting from the Diels-Alder adducts of cyclic ketones. This not only gave us access to remarkably strained oxetane systems, but also the mechanism for their protolytic ring opening provided a great deal of insight to how the strain affects the reactivity. Additionally, we discovered that although the model Hetero-Diels-Alder adducts did not undergo [2+2] cycloaddition, both exo- and endo-Sulfa-Diels-Alder products, nonetheless, were photochemically active and various products with defined stereochemistry could be produced upon photolysis. In conclusion, we have developed an approach to the encoding and screening of solution phase libraries based on the photorelease of externally sensitized photolabile tags. The encoding tags can be released into solution only when a binding event occurs between the ligand and the receptor, equipped with an electron transfer sensitizer. The released tags are analyzed in solution revealing the identity of the lead ligand or narrowing the range of potential leads.

A contribution on modeling methodologies for multibody systems.

Multibody System Dynamics has been responsible for revolutionizing Mechanical Engineering Design by using mathematical models to simulate and optimize the dynamic behavior of a wide range of mechanical systems. These mathematical models not only can provide valuable informations about a system that could otherwise be obtained only by experiments with prototypes, but also have been responsible for the development of many model-based control systems. This work represents a contribution for dynamic modeling of multibody mechanical systems by developing a novel recursive modular methodology that unifies the main contributions of several Classical Mechanics formalisms. The reason for proposing such a methodology is to motivate the implementation of computational routines for modeling complex multibody mechanical systems without being dependent on closed source software and, consequently, to contribute for the teaching of Multibody System Dynamics in undergraduate and graduate levels. All the theoretical developments are based on and motivated by a critical literature review, leading to a general matrix form of the dynamic equations of motion of a multibody mechanical system (that can be expressed in terms of any set of variables adopted for the description of motions performed by the system, even if such a set includes redundant variables) and to a general recursive methodology for obtaining mathematical models of complex systems given a set of equations describing the dynamics of each of its uncoupled subsystems and another set describing the constraints among these subsystems in the assembled system. This work also includes some discussions on the description of motion (using any possible set of motion variables and admitting any kind of constraint that can be expressed by an invariant), and on the conditions for solving forward and inverse dynamics problems given a mathematical model of a multibody system. Finally, some examples of computational packages based on the novel methodology, along with some case studies, are presented, highlighting the contributions that can be achieved by using the proposed methodology.

Avaliação de elementos potencialmente tóxicos em tintas

Neste trabalho são apresentados os resultados da determinação, por ICP OES, de elementos tóxicos e/ou potencialmente tóxicos (AI, Cr, Ni, Cu, Cd, As, Co e Pb) em tintas de acabamento imobiliário à base de água ou de solvente orgânico. Foram desenvolvidas e comparadas método de digestão de amostras utilizando diferentes misturas ácidas em bombas de decomposição, em fomo de microondas (sistema com radiação focalizada e com cavidade) e método de cinzas. O Método de digestão utilizando fomo de microondas com cavidade permitiu solubilização rápida e eficiente de todos os tipos de tintas testados, em tempo inferior a 35 minutos. As método apresentaram valores aceitáveis para a maioria dos elementos nos testes de adição e recuperação dos analitos. Os resíduos resultantes da digestão foram avaliados por MEV-EDS e não apresentaram os elementos estudados, comprovando a eficiência da metodologia. Mercúrio foi determinado usando um Analisador Direto de Mercúrio (DMA) e apresentou valores entre 43,0 ± 4,5 e 188 ± 9 µg Kg-1, valor considerado baixo quando comparado ao limite de 100 mg Kg-1, estabelecido na norma NRR 10004 para disposição de resíduos sólidos sem instalações especiais. O estudo da migração dos elementos para o ambiente após a exposição da tinta a agentes \"agressores\" , como raios ultravioletas e umidade, foi realizado usando câmara do tipo \"Weather-Ometer\" (envelhecimento acelerado). A avaliação dos resultados foi feita por MEV EDS e ICP OES. As micrografias de MEV mostraram que houve mudança na morfologia do polímero que foi submetido ao intemperismo acelerado. Os resultados obtidos não foram conclusivos quanto à migração dos analitos em função da baixa razão entre as massas degradada e não degradada das amostras. Uma proposta de metodologia para a avaliação por ICP OES das tintas e da disponibilidade de elementos tóxicos e potencialmente tóxicos, baseada na lixiviação de amostras secas em ambiente controlado é apresentada. São mostrados resultados de lixiviação de AI, Cr, Ni, Cu, Cd, As, Co e Pb com vários extratores e tempos diferentes de extração. Os resultados mostram que ocorre a migração de alguns elementos para as soluções estudadas e que, dos extratores avaliados, a chuva ácida apresentou maior potencial de lixiviação.

Concepção de um receptor de cavidade para concentração de energia solar para aplicação em reatores químicos.

Este trabalho dimensionou um receptor de cavidade para uso como reator químico de um ciclo de conversão de energia solar para energia química. O vetor energético proposto é o hidrogênio. Isso implica que a energia solar é concentrada em um dispositivo que absorve a radiação térmica e a transforma em energia térmica para ativar uma reação química endotérmica. Essa reação transforma o calor útil em gás hidrogênio, que por sua vez pode ser utilizado posteriormente para geração de outras formas de energia. O primeiro passo foi levantar os pares metal/óxido estudados na literatura, cuja finalidade é ativar um ciclo termoquímico que possibilite produção de hidrogênio. Esses pares foram comparados com base em quatro parâmetros, cuja importância determina o dimensionamento de um receptor de cavidade. São eles: temperatura da reação; estado físico de reagentes e produtos; desgaste do material em ciclos; taxa de reação de hidrólise e outros aspectos. O par escolhido com a melhor avaliação no conjunto dos parâmetros foi o tungstênio e o trióxido de tungstênio (W/WO3). Com base na literatura, foi determinado um reator padrão, cujas características foram analisadas e suas consequências no funcionamento do receptor de cavidade. Com essa análise, determinaram-se os principais parâmetros de projeto, ou seja, a abertura da cavidade, a transmissividade da janela, e as dimensões da cavidade. Com base nos resultados anteriores, estabeleceu-se um modelo de dimensionamento do sistema de conversão de energia solar em energia útil para um processo químico. Ao se analisar um perfil de concentração de energia solar, calculou-se as eficiências de absorção e de perdas do receptor, em função da área de abertura de um campo de coleta de energia solar e da radiação solar disponível. Esse método pode ser empregado em conjunto com metodologias consagradas e dados de previsão de disponibilidade solar para estudos de concentradores de sistemas de produção de hidrogênio a partir de ciclos termoquímicos.

Do Methods Matter In Global Leadership Development? A Mixed-Methods Study Of A U.s.-Based International Mba Program

As world communication, technology, and trade become increasingly integrated through globalization, multinational corporations seek employees with global leadership experience and skills. However, the demand for these skills currently outweighs the supply. Given the rarity of globally ready leaders, global competency development should be emphasized in higher education programs. The reality, however, is that university graduate programs are often outdated and focus mostly on cognitive learning. Global leadership competence requires moving beyond the cognitive domain of learning to create socially responsible and culturally connected global leaders. This requires attention to development methods; however, limited research in global leadership development methods has been conducted. A new conceptual model, the global leadership development ecosystem, was introduced in this study to guide the design and evaluation of global leadership development programs. It was based on three theories of learning and was divided into four development methodologies. This study quantitatively tested the model and used it as a framework for an in-depth examination of the design of one International MBA program. The program was first benchmarked, by means of a qualitative best practices analysis, against the top-ranking IMBA programs in the world. Qualitative data from students, faculty, administrators, and staff was then examined, using descriptive and focused data coding. Quantitative data analysis, using PASW Statistics software, and a hierarchical regression, showed the individual effect of each of the four development methods, as well as their combined effect, on student scores on a global leadership assessment. The analysis revealed that each methodology played a distinct and important role in developing different competencies of global leadership. It also confirmed the critical link between self-efficacy and global leadership development.

Forensic analysis of buildings affected by mining subsidence based on Differential Interferometry (Part III)

This work presents a forensic analysis of buildings affected by mining subsidence, which is based on deformation data obtained by Differential Interferometry (DInSAR). The proposed test site is La Union village (Murcia, SE Spain) where subsidence was triggered in an industrial area due to the collapse of abandoned underground mining labours occurred in 1998. In the first part of this work the study area was introduced, describing the spatial and temporal evolution of ground subsidence, through the elaboration of a cracks map on the buildings located within the affected area. In the second part, the evolution of the most significant cracks found in the most damaged buildings was monitored using biaxial extensometric units and inclinometers. This article describes the work performed in the third part, where DInSAR processing of satellite radar data, available between 1998 and 2008, has permitted to determine the spatial and temporal evolution of the deformation of all the buildings of the study area in a period when no continuous in situ instrumental data is available. Additionally, the comparison of these results with the forensic data gathered in the 2005–2008 period, reveal that there is a coincidence between damaged buildings, buildings where extensometers register significant movements of cracks, and buildings deformation estimated from radar data. As a result, it has been demonstrated that the integration of DInSAR data into forensic analysis methodologies contributes to improve significantly the assessment of the damages of buildings affected by mining subsidence.

Multi-agent system for control of robots inspired on the distributed activity and hormonal regulation of humans

Robotics is an emerging field with great activity. Robotics is a field that presents several problems because it depends on a large number of disciplines, technologies, devices and tasks. Its expansion from perfectly controlled industrial environments toward open and dynamic environment presents a many new challenges. New uses are, for example, household robots or professional robots. To facilitate the low cost, rapid development of robotic systems, reusability of code, its medium and long term maintainability and robustness are required novel approaches to provide generic models and software systems who develop paradigms capable of solving these problems. For this purpose, in this paper we propose a model based on multi-agent systems inspired by the human nervous system able to transfer the control characteristics of the biological system and able to take advantage of the best properties of distributed software systems. Specifically, we model the decentralized activity and hormonal variation.

Bio-based PLA_PHB plasticized blend films: Processing and structural characterization

Bio-based films formed by poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) plasticized with an oligomer of the lactic acid (OLA) were used as supporting matrices for an antibacterial agent (carvacrol). This paper reports the main features of the processing and physico-chemical characterization of these innovative biodegradable material based films, which were extruded and further submitted to filmature process. The effect of the addition of carvacrol and OLA on their microstructure, chemical, thermal and mechanical properties was assessed. The presence of these additives did not affect the thermal stability of PLA_PHB films, but resulted in a decrease in their crystallinity and in the elastic modulus for the active formulations. The obtained results showed the effective presence of additives in the PLA or the PLA_PHB matrix after processing at high temperatures, making them able to be used in active and bio-based formulations with antioxidant/antimicrobial performance.

Ventilated Stone Veneer: Mechanical Behaviour, Calculation Methodologies, Major Pathologies and Existing Tests

The increase of building pathologies related to the use of stone materials and the use of ventilated stone veneers, requires the reformulation of design concepts in building façades and also the reformulation of the architectural project. The aim of this paper is to identify, analyze and evaluate synthetically building pathologies in stone ventilated façades in order to obtain the main technical conditions to be considered in the architectural design, by interpreting its mechanical behavior and capabilities to prevent such pathologies and to ensure the proper features during the building lifetime. The methodology is based on both laboratory stone tests and in situ tests about construction systems, by analyzing physical and mechanical behavior of the outer layer in relation to other building requirements. The results imply the need of proper sizing, specific quality control and practical application of calculation methods, to control high concentration pressures in ventilated façades by reaching appropriate project solutions. In conclusion, the research about different pathologies of stone ventilated façades, the study of their mechanical behavior, their anchorage and their connection with their constructive aspects, will help to improve the construction quality of the stone ventilated façade in buildings and to enhance the use of natural stone in modern architecture.

The European Commission and International Trade Negotiations: A Principal-Agent Approach. IES WORKING PAPER 2/2011

Starting from the concept of delegation of power in external trade policy, this paper aims to investigate the dynamics surrounding the European Union’s position in international trade negotiations. The analysis centres on the role of the European Commission (the agent), which by means of Treaty-based delegation and as mandated by the Council (the principal) acts as the sole trade negotiator in the international sphere on behalf of the European Union (EU). The broader negotiating process is thus conceptualised as a threelevel game, where the Commission holds an intermediary position between the European and international levels and also interacts with the Member States in the Council. After an insight into the European decision-making process for external trade, the paper further analyses the Commission’s role during the multilateral trade negotiations of the Doha Development Round. By applying the principal-agent theory to international trade negotiations in general, and subsequently to the controversial agricultural negotiations, this paper seeks to investigate some of the potential sources of autonomy that the Commission can draw upon while upholding an EU position at the international level, in addition to the “hardball” job of balancing the interests of the Member States with those of World Trade Organisation (WTO) partners. Along these lines, the paper finally aims to contribute to the literature concerning agency autonomy in EU external trade relations but also to provide a better understanding of inter-institutional relations within the EU as they may unfold in practice.

Contributions to Physics-Based Aeroservoelastic Uncertainty Analysis

Thesis (Ph.D.)--University of Washington, 2016-06

Development of PCR-based markers for detection of Leifsonia xyli subsp. xyli in fibrovascular fluid of infected sugarcane plants

DNA of Leifsonia xyli subsp. xyli (Lxx), the causal agent of ratoon stunting disease of sugarcane, was detected in the fibrovascular fluid of sugarcane plants using random amplified polymorphic DNA PCR-based amplification using two 10-mer oligonucleotide primers. The primers OPC-02 and OPC-11 produced Lxx-specific markers of approximately 800 bp and 1000 bp, respectively. A cloned DNA fragment from the 800 bp PCR product (pSKC2-800) hybridised to a single genomic DNA fragment from Lxx when used as a probe in Southern hybridisation. This cloned fragment did not hybridise to L. xyli subsp. cynodontis (Lxc), or L. xyli-like bacteria isolated from grasses in Australia, indicating the usefulness of this DNA fragment as a specific probe for Lxx. A cloned fragment from the 1000 bp PCR product ( pSKC11-1000) hybridised to three genomic fragments in Lxx isolates, one genomic fragment in two of the four isolates of L. xyli-like bacteria, and in two of the four isolates of Lxc isolated from the USA. These results indicate that L. xyli-like bacteria are more likely to be related to Lxc than Lxx. These probes did not hybridise to the DNA from strains of the species of Clavibacter, Rathayibacter, Acidovorax, Ralstonia, Pseudomonas and Xanthomonas tested. Two oligonucleotide primers (21-mer) designed from the pSKC2-800 sequences specifically amplified template DNA from Lxx and detected as few as 5 x 10(4) cells/mL in fibrovascular fluid from sugarcane plants infected with Lxx.

Refinement of a cell line based artificial diet for rearing the parasitoid wasp, Trichogramma pretiosum

An artificial diet incorporating insect cells originally developed for Trichogramma australicum Girault (Hymenoptera: Tricho-grammatidae) was successfully used to rear Trichogramm pretiosum Riley (Hymenoptera: Trichogrammatidae). To refine the diet, individual components were removed. Chicken egg yolk and the insect cells were identified as the most important components for T. pretiosum development. Their removal resulted in few pupae and no adults. Removal of Grace's insect medium, a common component of artificial diets, was found to markedly improve the development of T pretiosum, producing 60% larva to pupa transition and 19% pupa to adult transition. There was no significant difference in T pretiosum development on diets in which milk powder, malt powder or infant formula were interchanged, despite differences in nutrient composition. The use of yeast extract resulted in significantly higher survival to the adult stage when compared with yeast hydrolysate enzymatic and a combination of yeast extract and yeast hydrolysate enzymatic. Comparison of four antimicrobial agents showed the antibacterial agent Gentamycin and the antifungal agent Nystatin had the least detrimental effect on T pretiosum development. The use of insect cell line diets has the potential to simplify artificial diet production and significantly reduce T pretiosum production costs in Australia compared to diets using insect hemolymph or the use of natural or factitious hosts. (c) 2005 Elsevier Inc. All rights reserved.

Intelligent agent supported personalization for virtual learning environments

Virtual learning environments (VLEs) are computer-based online learning environments, which provide opportunities for online learners to learn at the time and location of their choosing, whilst allowing interactions and encounters with other online learners, as well as affording access to a wide range of resources. They have the capability of reaching learners in remote areas around the country or across country boundaries at very low cost. Personalized VLEs are those VLEs that provide a set of personalization functionalities, such as personalizing learning plans, learning materials, tests, and are capable of initializing the interaction with learners by providing advice, necessary instant messages, etc., to online learners. One of the major challenges involved in developing personalized VLEs is to achieve effective personalization functionalities, such as personalized content management, learner model, learner plan and adaptive instant interaction. Autonomous intelligent agents provide an important technology for accomplishing personalization in VLEs. A number of agents work collaboratively to enable personalization by recognizing an individual's eLeaming pace and reacting correspondingly. In this research, a personalization model has been developed that demonstrates dynamic eLearning processes; secondly, this study proposes an architecture for PVLE by using intelligent decision-making agents' autonomous, pre-active and proactive behaviors. A prototype system has been developed to demonstrate the implementation of this architecture. Furthemore, a field experiment has been conducted to investigate the performance of the prototype by comparing PVLE eLearning effectiveness with a non-personalized VLE. Data regarding participants' final exam scores were collected and analyzed. The results indicate that intelligent agent technology can be employed to achieve personalization in VLEs, and as a consequence to improve eLeaming effectiveness dramatically.

Community-based programs to promote care seat restraints in children 0-16 years - A systematic review

Study Objective: Community-based models for injury prevention have become an accepted part of the overall injury control strategy. This systematic review of the scientific literature examines the evidence for their effectiveness in reducing injury due to inadequate car seat restraint use in children 0-16 years of age. Methods: A comprehensive search of the literature was performed using the following study selection criteria: community-based intervention study: target population was children aged 0-16 years of age; outcome measure was either injury rates due to motor vehicle crashes or observed changes in child restraint use; and use of community control or historical control in the study design. Quality assessment and data abstraction was guided by a standardized procedure and performed independently by two authors. Data synthesis was in tabular and text form with meta-analysis not being possible due to the discrepancy in methods and measures between the studies. Results: This review found eight studies, that met all the inclusion criteria. In the studies that measured injury outcomes, significant reductions in risk of motor vehicle occupant injury (33-55%) were reported in the study communities. For those studies reporting observed car seat restraint use the community-based programs were successful in increasing toddler restraint use in 1-5 year aged children by up to 11%; child booster seat use in 4-8 year aged children by up to 13%; rear restraint use in children aged 0-15 years by 8%; a 50% increase in restraint use in pre-school aged children in a high-risk community; and a 44% increase in children aged 5-11 years. Conclusion: While this review highlights that there is some evidence to support the effectiveness of community-based programs to promote car restraint use and/or motor vehicle occupant injury, limitations in the evaluation methodologies of the studies requires the results to be interpreted with caution. There is clearly a need for further high quality program evaluation research to develop an evidence base. (C) 2004 Elsevier Ltd. All rights reserved.