Adiamento da aposentadoria e o significado do trabalho para servidores de uma universidade federal

This study investigated the intention of the older workers to continue working after state pension age/time. On this way, it explores the relation between this intention and factors related with the meanings of the work and retirement. Specifically, it was examined that factors related to work and non-work are predictors of the intention to continue working, and it was explored if meanings of retirement are linked to this decision. It is a crosssectional mixed methods study, using a survey conducted with 283 federal civil servants of a federal Northeastern University which were near retirement. It envolved an on-line questionnaire, with open-ended questions and the likert-type scale "Older Worker's Intention to Continue Working" (OWICW) of Shacklock and Brunneto (2011), which was validated to the Brazilian version. The quantitative data were analyzed using descriptive and multivariate statistics, specifically procedures for comparing means and coefficients of multiple logistic regression. The qualitative data were analyzed using the lexicographical technique Descending Hierarchical Classification. The findings indicate that most participants want to continue in paid work, and that perception of personal autonomy at work, interpersonal relationships at work, interests outside of work, and flexible working arrangements are significant predictors of intention to continue working. Furthermore, the perception of personal autonomy at work, flexible working arrangements, and the financial incentives are predictors of decision to postpone retirement and remain in the organization. The analysis revealed five patterns of meanings of retirement: "worker's right", "resting", "idle time at home", "new stage in the life course", and "enjoy the use of time���. The decision to postpone retirement is linked to idleness and lack of substitutionary activities work, and the decision to stop working linked to retirement as a life with more quality. The study provides information that can contribute with management policies before the process of retirement decision.

A gest��o educacional das secretarias municipais de educa����o de munic��pios maranhenses a partir do plano de a����es articuladas 2007-2011

The main purpose of this thesis was to analyze educational management of Municipal Departments of Education (SEMED���s) of cities in Maranh��o inserted in the Plan of Articulated Actions (2007- 2011). We evidence the role of Union in that public policy. The leading argument is that Brazilian federal government is not demos constraining in relation to its national sub-governments, what makes the central government to enforce, primarily, educational politics like PAR. This kind of politics interferes in the educational management by national sub-governments, turning them into mere executors. By turning them into mere executors, PAR limits their autonomy and over imposes the results-based management as a parameter to improve the education quality. In order to develop the hypothesis, we adopted Political Science as theoretical basis, represented by Federalism Theory as pact which premise is the cooperative pattern of federalism as being the best form of government because it allows a joint decision-making process from the idea of no centralization of power. The methodology was historical materialism, which assumes the totality and contradiction as a form to understand the phenomenon that does not express in direct way its existence, but can be analyzed from such categories that made possible to interpret the reality. So, we used as tools the semistructured interview and documental analyses with triangulation of data. The empirical basis of the research is 04 (four) cities in Maranh��o that obey the following criteria: 1. The municipality has to be assigned on the FNDE Resolution n�� 29/2007; 2. To present the lowest educational management indexes from the diagnosis made in loco by PAR; 3. To present the lowest financial management indexes based on the diagnosis in loco by PAR. The results suggest that PAR does not effect a resultbased management which are proposed in its legal rules neither the SEMEDs can propose their conception of educational management. That situation creates a hybridism that sometimes turns to managerialism and performativity, sometimes to bureaucracy, sometimes to a total uncoordinated and unarticulated action. In relation to SEMEDs management, this thesis shows that these institutions have no own conception about educational management and end up acting in an uncoordinated and unarticulated way. The thesis concludes that PAR is an over imposition by federal government towards national sub-governments that conflicts with management patterns of those institutions that are used to a less managerial logic. This over imposition makes the Central government to be the center of Brazilian federalism, which is in reality an incomplete pact.

The Role of TET Proteins in the Epigenetic Regulation of Neural Gene Expression and Behavior

<p>Understanding how genes affect behavior is critical to develop precise therapies for human behavioral disorders. The ability to investigate the relationship between genes and behavior has been greatly advanced over the last few decades due to progress in gene-targeting technology. Recently, the Tet gene family was discovered and implicated in epigenetic modification of DNA methylation by converting 5-methylcytosine to 5-hydroxymethylcytosine (5hmC). 5hmC and its catalysts, the TET proteins, are highly abundant in the postnatal brain but with unclear functions. To investigate their neural functions, we generated new lines of Tet1 and Tet3 mutant mice using a gene targeting approach. We designed both mutations to cause a frameshift by deleting the largest coding exon of Tet1 (Tet1��e4) and the catalytic domain of Tet3 (Tet3��e7-9). As Tet1 is also highly expressed in embryonic stem cells (ESCs), we generated Tet1 homozygous deleted ESCs through sequential targeting to compare the function of Tet1 in the brain to its role in ESCs. To test our hypothesis that TET proteins epigenetically regulate transcription of key neural genes important for normal brain function, we examined transcriptional and epigenetic differences in the Tet1��e4 mouse brain. The oxytocin receptor (OXTR), a neural gene implicated in social behaviors, is suggested to be epigenetically regulated by an unknown mechanism. Interestingly, several human studies have found associations between OXTR DNA hypermethylation and a wide spectrum of behavioral traits and neuropsychiatric disorders including autism spectrum disorders. Here we report the first evidence for an epigenetic mechanism of Oxtr transcription as expression of Oxtr is reduced in the brains of Tet1��e4-/- mice. Likewise, the CpG island overlapping the promoter of Oxtr is hypermethylated during early embryonic development and persists into adulthood. We also discovered altered histone modifications at the hypermethylated regions, indicating the loss of TET1 has broad effects on the chromatin structure at Oxtr. Unexpectedly, we discovered an array of novel mRNA isoforms of Oxtr that are selectively reduced in Tet1��e4-/- mice. Additionally, Tet1��e4-/- mice display increased agonistic behaviors and impaired maternal care and short-term memory. Our findings support a novel role for TET1 in regulating Oxtr expression by preventing DNA hypermethylation and implicate TET1 in social behaviors, offering novel insight into Oxtr epigenetic regulation and its role in neuropsychiatric disorders.</p>

Caract��risation des interactions ��tablies par la r��gion riche en prolines de la ligase de l���ubiquitine Itch.

Itch est un membre de la famille des ligases de l���ubiquitine de type CWH (C2-WW- HECT) impliqu�� dans le contr��le de la signalisation inflammatoire, des facteurs de transcription et le tri des r��cepteurs membranaires. La fonction d���Itch implique g��n��ralement sa capacit�� �� induire la d��gradation de ses substrats. Pour accomplir cette fonction, Itch doit d���abord interagir avec ses cibles. Itch poss��de quatre domaines WW lui permettant d���accomplir la majorit�� de ses fonctions. En plus de ces domaines, Itch poss��de une PRR (r��gion riche en prolines) unique parmi les ligases CWH. Cette r��gion est bien conserv��e chez les vert��br��s, ce qui sugg��re son importance. Cette r��gion permet �� Itch d���interagir avec des prot��ines contenant un domaine SH3 (Src homology 3). Plusieurs partenaires SH3 furent identifi��s, cependant l���on connait peu de choses concernant la fonction et l�����tablissement de ces complexes. Dans ce projet, nous avons analys�� les propri��t��s de liaison d���un sous-groupe de prot��ines �� domaine SH3 impliqu��es dans l���endocytose et la signalisation cellulaire. Nos travaux ont permis d���identifier de nouveaux partenaires et aussi de d��terminer que diff��rents domaines SH3 ciblent la m��me r��gion riche en prolines, mais impliquent des r��sidus distincts. Ces r��sultats d��montrent la vari��t�� des propri��t��s de liaison d��montr��es par la PRR d���Itch et sa pr��f��rence marqu��e pour l���Endophiline. Parmi les partenaires identifi��s, Grb2 (Growth factor receptor-bound protein 2) est particuli��rement int��ressant en raison de son r��le crucial dans la signalisation cellulaire. Nous avons d��montr�� ici qu���Itch ubiquityle Grb2, mais ne cause pas sa d��gradation, contrairement �� l���Endophiline. Nos travaux d��montrent que la PRR d���Itch est versatile quant �� ses interactions et leurs cons��quences.

Weaning from ventilation

Aims/purpose: Getting off the ventilator is an important patient-centred outcome for patients with acute respiratory failure. It signifies an improvement in patient condition, enables easier communication, reduces fear and anxiety and consequently a reduced requirement for sedatives. Weaning from ventilation therefore is a core ICU nursing task that is addressed in this presentation. <br/>Presentation description: There are different schools of thought on when ventilator weaning begins including: (a) from intubation with titration of support; and (b) only when the patient���s condition improves. There are also different schools of thought on how to wean including gradual reductions in ventilator support to: (a) a low level consistent with extubation; or (b) to a level to attempt a spontaneous breathing trial followed by extubation if successful. Regardless of the approach, what is patient-relevant is the need to determine early when the patient may be ���ready��� to discontinue ventilation. This time point can be assessed using simple criteria and should involve all ICU staff to the level of their experience. This presentation challenges the notion that only senior nurses or nurses with a ���weaning course��� should be involved in the weaning process and proposes opportunities for engaging nurses with all levels of experience.<br/>Conclusion: An ICU nursing taskforce that is focused and engaged in determining patient readiness for weaning can make a strong contribution to patient-relevant outcomes.<br/>

The Hidden benefits of ���poster presentation assessment���: Skill acquirement and learning; evaluated from the nursing students perspective

Introduction <br/>This paper reports to an exercise in evaluating poster group work and poster presentation and the extra learning and skill acquisition that this can provide to nursing students, through a creative and stimulating assessment method. Much had been written about the benefits of using posters as an assessment method, yet there appears to be a lack of research that captures the student experience. <br/>Aim<br/>This evaluative study sought to evaluate the student experience by using a triangulation approach to evaluation:<br/>Methodology<br/>All students from the February 2015 nursing intake, were eligible to take part (80 students) of which 71 participated (n=71). The poster group presentations took place at the end of their first phase of year one teaching and the evaluation took place at the end of their first year as undergraduate. Evaluation involved;<br/>1. Quantitative data by questionnaires<br/>2. Qualitative data from focus group discussions<br/>Results<br/>A number of key themes emerged from analysis of the data which captured the ���added value��� of learning from the process of poster assessment including:<br/>��� Professionalism: developing time keeping skills, presenting skills.<br/>��� Academic skills: developing literature search, critic and reporting<br/>��� Team building and collaboration<br/>Overall 88% agreed that the process furnished them with additional skills and benefits above the actual production of the poster, with 97% agreeing that these additional skills are important skills for a nurse. <br/>Conclusion<br/>These results would suggest that the process of poster development and presentation furnish student nurses with many additional skills that they may not acquire through other types of assessment and are therefore beneficial. The structure of the assessment encourages a self-directed approach so students take control of the goals and purposes of learning. The sequential organization of the assessment guides students in the transition from dependent to self-directed learners. <br/><br/><br/>

Caracteriza����o e Factores que Influenciam o Desempenho dos Bombeiros Profissionais: estudo explorat��rio

�� indubit��vel que a decis��o est�� presente no dia-a-dia de todos n��s, independentemente do tipo de actividade em que estamos envolvidos. Na vida organizacional, enfrentamos muitas situa����es que exigem uma resposta moment��nea, aqui denominadas de imediatas, as quais n��o permitem uma recolha de informa����o adequada, tempo para reflex��o, discuss��o e troca de ideias, entre outras restri����es. Al��m das limita����es j�� citadas por outros autores, como a pr��pria capacidade cognitiva do indiv��duo, faculdade de processamento, h�� outros elementos que influenciam o processo de tomada de decis��o, especialmente em ambientes sob press��o e em constante muta����o, como �� o dos bombeiros. O presente trabalho procura conhecer quais os factores que influenciam a tomada de decis��o de bombeiros profissionais com fun����es de chefia, em ocorr��ncias de inc��ndios urbanos e acidentes de via����o. Neste contexto, foram abordados alguns enquadramentos para a tomada de decis��o, como o Modelo da Tomada de Decis��o da Primeira Op����o Identificada (TDPOI) de Gary Klein, entre outros. No sentido de aprofundar a nossa investiga����o, foram realizados dois estudos explorat��rios atrav��s de entrevistas presenciais. A amostra �� constitu��da por 14 profissionais do sector, entre eles bombeiros com fun����es de chefia, comandantes e delegados sindicais. Os resultados obtidos mostraram que a experi��ncia e a forma����o s��o os factores que se evidenciam, e influenciam a decis��o dos bombeiros. Constatamos que nos Bombeiros Portugueses a experi��ncia �� uma caracter��stica dos decisores, pois s��o eles que far��o as op����es de alto risco. Por outro lado, apesar de a forma����o visar a aquisi����o de compet��ncias profissionais, nomeadamente na ��rea da decis��o, esta carece de actualiza����o, porque n��o satisfaz as necessidades dos bombeiros. Apresentam-se tamb��m as principais limita����es do estudo e sugest��es para investiga����es futuras. / Undoubtedly, the decision is present in day-to-day for us all, regardless of the type of activity we are involved. In organizational life, we face many situations that require a momentary response, here called the immediate, which do not allow collection of adequate information, time for reflection, discussion and exchange of ideas, among other restrictions. Besides the limitations already mentioned by other authors, as the individual's cognitive capacity, processing power, there are other factors that influence the decision-making process, especially in environments under pressure and constantly changing, as is the Fire. This paper seeks to know which factors influence the decision making of professional firefighters with leadership roles in urban fire occurrences and accidents. In this context, we discuss some frameworks for decision making, as the Recognition-Primed Decision (RPD) Model by Gary Klein, among others. In order to further our investigation, two exploratory studies were conducted through personal interviews. The sample consists of 14 professionals, including firefighters with executive functions, commanders and union representatives. The results showed that the experience and training are factors that are evident, and influence the decision of the firefighters. We note that the Portuguese Firemen experience is a characteristic of decision-makers because they are options that will make high-risk. On the other hand, although the training to aim at the acquisition of professional skills, particularly in the area of decision, it needs updating, because it meets the needs of firefighters. We present also the main limitations of the study and suggestions for future investigations.

Marketing de relacionamento em um provedor de internet: um estudo comparativo que considera a vis��o gerencial e a percep����o dos clientes

The current paper aims at analyzing customer retention in Internet provider services. For this study, we sought to understand what are the client's expectations regarding the services available and compare them with management perception in relation to the use of those services. Identifying the coherence level between the two points of view, management and client, it is possible to pinpoint how service is assessed in real conditions. Then, from this point on, a new vision can be implemented on available services, and new customer service strategies aiming at best serving to their expectation and need, can be rethought. The exploratory research was utilized. It was based on case study, and quantitative and qualitative methods were used. The quantitative method was done by applying the cluster technique with six variables of control derived from the six main services, whose definition was done through qualitative survey of the internal management team. Then, an structured interview with 443 clients, from a probabilistic sample of 800 costumers. The total number of active clients of the internet provider is of 10.677. Client perception in relation to services varied, if compared with the four services that were under the managerial metric method, this comparison showed a more positive evaluation than the real use of the service. Thus, it was observed that the value of each service available for the client depends on his/her perception of it, regardless of using or not the offered service. As a result, it is possible to understand which services offered by the company under study effectively contribute to a good client-company relationship, and the upkeep of those clients

Saccharomycotin transcriptomics by next-generation sequencing

The non-standard decoding of the CUG codon in Candida cylindracea raises a number of questions about the evolutionary process of this organism and other species Candida clade for which the codon is ambiguous. In order to find some answers we studied the transcriptome of C. cylindracea, comparing its behavior with that of Saccharomyces cerevisiae (standard decoder) and Candida albicans (ambiguous decoder). The transcriptome characterization was performed using RNA-seq. This approach has several advantages over microarrays and its application is booming. TopHat and Cufflinks were the software used to build the protocol that allowed for gene quantification. About 95% of the reads were mapped on the genome. 3693 genes were analyzed, of which 1338 had a non-standard start codon (TTG/CTG) and the percentage of expressed genes was 99.4%. Most genes have intermediate levels of expression, some have little or no expression and a minority is highly expressed. The distribution profile of the CUG between the three species is different, but it can be significantly associated to gene expression levels: genes with fewer CUGs are the most highly expressed. However, CUG content is not related to the conservation level: more and less conserved genes have, on average, an equal number of CUGs. The most conserved genes are the most expressed. The lipase genes corroborate the results obtained for most genes of C. cylindracea since they are very rich in CUGs and nothing conserved. The reduced amount of CUG codons that was observed in highly expressed genes may be due, possibly, to an insufficient number of tRNA genes to cope with more CUGs without compromising translational efficiency. From the enrichment analysis, it was confirmed that the most conserved genes are associated with basic functions such as translation, pathogenesis and metabolism. From this set, genes with more or less CUGs seem to have different functions. The key issues on the evolutionary phenomenon remain unclear. However, the results are consistent with previous observations and shows a variety of conclusions that in future analyzes should be taken into consideration, since it was the first time that such a study was conducted.

Returns to shareholder activism: Evidence from a clinical study of the hermes UK focus fund

This article reports a unique analysis of private engagements by an activist fund. It is based on data made available to us by Hermes, the fund manager owned by the British Telecom Pension Scheme, on engagements with management in companies targeted by its UK Focus Fund. In contrast with most previous studies of activism, we report that the fund executes shareholder activism predominantly through private interventions that would be unobservable in studies purely relying on public information. The fund substantially outperforms benchmarks and we estimate that abnormal returns are largely associated with engagements rather than stock picking. �� The Author 2008.

Situa����es-problema no ensino de matem��tica financeira

O presente trabalho descreve uma proposta de atividade educacional direcionada para professores de Matem��tica, envolvendo situa����es-problema no ensino de Matem��tica Financeira para ser aplicado com alunos do Ensino M��dio. Tais atividades tem como objetivo fornecer um contexto real, no qual o estudante esteja inserido. O trabalho se divide em quatro partes: a introdu����o de uma situa����oproblema envolvendo juros simples, o conhecimento matem��tico, a resolu����o da situa����o-problema e a proposta de atividade educacional. Diferenciando-se do que usualmente �� encontrado nos livros did��ticos, a proposta aqui apresentada prop��e estudar conte��dos matem��ticos de forma articulada, envolvendo o conceito de porcentagem vinculado com fun����es lineares e juros simples com fun����o afim e progress��o aritm��tica. Dessa forma, �� apresentada uma sequ��ncia de aulas envolvendo situa����es-problema atrav��s de atividades, adequadas para os alunos.

Queijo minas padr��o com reduzido teor de s��dio: composi����o e caracteriza����o sensorial

Sodium is an essential nutrient with important functions in the organism, however, its ingestion in excess may cause various health problems such as arterial hypertension, brain diseases, heart failure and chronic renal failure. In this context, the present study proposes to prepare Minas Padr��o cheese with different contents of sodium with the objective of evaluating the effect of the addition of potassium chloride in sensory characteristics and hysicochemical properties, as well as in the proximal composition and in microbiological quality. The cheeses were elaborate in concentrations of 100% of NaCl (C), 80% of NaCl + 20% of KCl (T1), 60% of NaCl + 40% of KCl (T2), 40% of NaCl + 60% of KCl (T3) and 20% of NaCl + 80% of KCl (T4) and stored for 20 days at 10 ��C. The proximal composition and physicochemical was based on the determination of moisture content, fat, protein, ash, chloride, sodium, potassium, titratable acidity and pH of all treatments after 20 days of storage. The microbiological quality of the samples was monitored through the count of Total Coliforms and Escherichia coli, Staphylococcus aureus, Salmonella spp., mold and yeast in the first and fifteenth day of storage. The sensorial characterization was performed by the technique of Free Profile choice. The results showed that the replacement of sodium chloride by potassium in the Minas Padr��o cheese in concentration higher than 40% presented significantly higher moisture contents. Cheese with a reduction greater than 60% of sodium obtained significantly effect in the titratable acidity, presenting higher values compared to the other treatments. The cheese with 20% of salt replacement did not differ statistically in relation to the control. When the proportion of substituent was increased, a significant reduction of the sodium content of up to 73% was observed. As the sodium was replaced by potassium in cheese, the potassium content increased significantly, stablishing a reduction of 82% in relation to the control. There was no effect to sodium substitution by potassium in fat, protein, ash and chlorides, as well as the pH values. The microbiological results were in accordance with the current legislation, therefore suitable to be eaten. According to the Free Profile Choice technique it was observed that the control C cheese (100% of NaCl) showed results very close to the other treatments, differing only in flavor attributes. The replacement of sodium by potassium in proportions of 20% contributed to a bitter taste detected by the tasters. Whereas, the appearance, flavor and texture attributes showed no significant differences compared to the Minas Padr��o cheese.

'Bayesian Optimisation for Nurse Scheduling'

A Bayesian optimisation algorithm for a nurse scheduling problem is presented, which involves choosing a suitable scheduling rule from a set for each nurse's assignment. When a human scheduler works, he normally builds a schedule systematically following a set of rules. After much practice, the scheduler gradually masters the knowledge of which solution parts go well with others. He can identify good parts and is aware of the solution quality even if the scheduling process is not yet completed, thus having the ability to finish a schedule by using flexible, rather than fixed, rules. In this paper, we design a more human-like scheduling algorithm, by using a Bayesian optimisation algorithm to implement explicit learning from past solutions. A nurse scheduling problem from a UK hospital is used for testing. Unlike our previous work that used Genetic Algorithms to implement implicit learning [1], the learning in the proposed algorithm is explicit, i.e. we identify and mix building blocks directly. The Bayesian optimisation algorithm is applied to implement such explicit learning by building a Bayesian network of the joint distribution of solutions. The conditional probability of each variable in the network is computed according to an initial set of promising solutions. Subsequently, each new instance for each variable is generated by using the corresponding conditional probabilities, until all variables have been generated, i.e. in our case, new rule strings have been obtained. Sets of rule strings are generated in this way, some of which will replace previous strings based on fitness. If stopping conditions are not met, the conditional probabilities for all nodes in the Bayesian network are updated again using the current set of promising rule strings. For clarity, consider the following toy example of scheduling five nurses with two rules (1: random allocation, 2: allocate nurse to low-cost shifts). In the beginning of the search, the probabilities of choosing rule 1 or 2 for each nurse is equal, i.e. 50%. After a few iterations, due to the selection pressure and reinforcement learning, we experience two solution pathways: Because pure low-cost or random allocation produces low quality solutions, either rule 1 is used for the first 2-3 nurses and rule 2 on remainder or vice versa. In essence, Bayesian network learns 'use rule 2 after 2-3x using rule 1' or vice versa. It should be noted that for our and most other scheduling problems, the structure of the network model is known and all variables are fully observed. In this case, the goal of learning is to find the rule values that maximize the likelihood of the training data. Thus, learning can amount to 'counting' in the case of multinomial distributions. For our problem, we use our rules: Random, Cheapest Cost, Best Cover and Balance of Cost and Cover. In more detail, the steps of our Bayesian optimisation algorithm for nurse scheduling are: 1. Set t = 0, and generate an initial population P(0) at random; 2. Use roulette-wheel selection to choose a set of promising rule strings S(t) from P(t); 3. Compute conditional probabilities of each node according to this set of promising solutions; 4. Assign each nurse using roulette-wheel selection based on the rules' conditional probabilities. A set of new rule strings O(t) will be generated in this way; 5. Create a new population P(t+1) by replacing some rule strings from P(t) with O(t), and set t = t+1; 6. If the termination conditions are not met (we use 2000 generations), go to step 2. Computational results from 52 real data instances demonstrate the success of this approach. They also suggest that the learning mechanism in the proposed approach might be suitable for other scheduling problems. Another direction for further research is to see if there is a good constructing sequence for individual data instances, given a fixed nurse scheduling order. If so, the good patterns could be recognized and then extracted as new domain knowledge. Thus, by using this extracted knowledge, we can assign specific rules to the corresponding nurses beforehand, and only schedule the remaining nurses with all available rules, making it possible to reduce the solution space. Acknowledgements The work was funded by the UK Government's major funding agency, Engineering and Physical Sciences Research Council (EPSRC), under grand GR/R92899/01. References [1] Aickelin U, "An Indirect Genetic Algorithm for Set Covering Problems", Journal of the Operational Research Society, 53(10): 1118-1126,

Localiza����o em espa��os interiores por luz vis��vel para rob��s m��veis

Esta disserta����o investiga a localiza����o em espa��os interiores atrav��s da comunica����o por luz vis��vel para rob��s m��veis, com base nos LEDs fixos nos edif��cios, dando particular aten����o �� simula����o e desenho do sensor, com vista ao desenvolvimento de um sensor de localiza����o. Explica-se o crescimento da tecnologia LED e da constante necessidade de localiza����o do homem em espa��os interiores. Apresentado algumas caracter��sticas do LED e dos foto-detetores existentes. Com uma breve referencia a algumas das comunica����es por luz vis��vel de baixo d��bito poss��veis de implementar. O desenvolvimento do prot��tipo do sensor inicia-se, principalmente, pela simula����o de alguns dispositivos essenciais e das suas carater��sticas, como o emissor LED no controlo do ^angulo de meia pot��ncia (HPA) e a altura a que se encontra, e no recetor foto-d��odo e a sua restri����o de campo de vis��o (FOV). Simula-se o sensor pretendido com o n��mero de foto-d��odos necess��rios otimizando o espa��o f��sico dispon��vel e fazendo n��o s�� um refinamento no FOV mas tamb��m na distribui����o espacial dos foto-d��odos com fun����es predefinidas para a redu����o de incertezas de decis��o de localiza����o do rob��. Estes resultados permitiram a constru����o f��sica do sensor, desde o suporte para os foto-d��odos, tendo em conta todas as medidas durante as simula����es, e terminando com o desenvolvimento dos sensores e a sua integra����o completa. O tratamento de dados da leitura dos sinais recebidos do sensor s��o tratados por um microcontrolador, permitindo calcular par��metros fundamentais no c��lculo da posi����o. No final, os resultados te��ricos bem como os pr��ticos obtidos ao longo do desenvolvimento e poss��veis propostas para trabalhos futuros que beneficiam desta investiga����o

Development of ultra-high-performance concrete (UHPC) using waste glass materials ��� towards innovative eco-friendly concrete

Le b��ton conventionnel (BC) a de nombreux probl��mes tels que la corrosion de l���acier d'armature et les faibles r��sistances des constructions en b��ton. Par cons��quent, la plupart des structures fabriqu��es avec du BC exigent une maintenance fr��quent. Le b��ton fibr�� �� ultra-hautes performances (BFUP) peut ��tre con��u pour ��liminer certaines des faiblesses caract��ristiques du BC. Le BFUP est d��fini �� travers le monde comme un b��ton ayant des propri��t��s m��caniques, de ductilit�� et de durabilit�� sup��rieures. Le BFUP classique comprend entre 800 kg/m�� et 1000 kg/m�� de ciment, de 25 �� 35% massique (%m) de fum��e de silice (FS), de 0 �� 40%m de poudre de quartz (PQ) et 110-140%m de sable de quartz (SQ) (les pourcentages massiques sont bas��s sur la masse totale en ciment des m��langes). Le BFUP contient des fibres d'acier pour am��liorer sa ductilit�� et sa r��sistance aux efforts de traction. Les quantit��s importantes de ciment utilis��es pour produire un BFUP affectent non seulement les co��ts de production et la consommation de ressources naturelles comme le calcaire, l'argile, le charbon et l'��nergie ��lectrique, mais affectent ��galement n��gativement les dommages sur l'environnement en raison de la production substantielle de gaz �� effet de serre dont le gas carbonique (CO[indice inf��rieur 2]). Par ailleurs, la distribution granulom��trique du ciment pr��sente des vides microscopiques qui peuvent ��tre remplis avec des mati��res plus fines telles que la FS. Par contre, une grande quantit�� de FS est n��cessaire pour combler ces vides uniquement avec de la FS (25 �� 30%m du ciment) ce qui engendre des co��ts ��lev��s puisqu���il s���agit d���une ressource limit��e. Aussi, la FS diminue de mani��re significative l���ouvrabilit�� des BFUP en raison de sa surface sp��cifique Blaine ��lev��e. L���utilisation du PQ et du SQ est ��galement co��teuse et consomme des ressources naturelles importantes. D���ailleurs, les PQ et SQ sont consid��r��s comme des obstacles pour l���utilisation des BFUP �� grande ��chelle dans le march�� du b��ton, car ils ne parviennent pas �� satisfaire les exigences environnementales. D���ailleurs, un rapport d'Environnement Canada stipule que le quartz provoque des dommages environnementaux imm��diats et �� long terme en raison de son effet biologique. Le BFUP est g��n��ralement vendu sur le march�� comme un produit pr��emball��, ce qui limite les modifications de conception par l'utilisateur. Il est normalement transport�� sur de longues distances, contrairement aux composantes des BC. Ceci contribue ��galement �� la g��n��ration de gaz �� effet de serre et conduit �� un co��t plus ��lev�� du produit final. Par cons��quent, il existe le besoin de d��velopper d���autres mat��riaux disponibles localement ayant des fonctions similaires pour remplacer partiellement ou totalement la fum��e de silice, le sable de quartz ou la poudre de quartz, et donc de r��duire la teneur en ciment dans BFUP, tout en ayant des propri��t��s comparables ou meilleures. De grandes quantit��s de d��chets verre ne peuvent pas ��tre recycl��es en raison de leur fragilit��, de leur couleur, ou des co��ts ��lev��s de recyclage. La plupart des d��chets de verre vont dans les sites d'enfouissement, ce qui est ind��sirable puisqu���il s���agit d���un mat��riau non biod��gradable et donc moins respectueux de l'environnement. Au cours des derni��res ann��es, des ��tudes ont ��t�� r��alis��es afin d���utiliser des d��chets de verre comme ajout cimentaire alternatif (ACA) ou comme granulats ultrafins dans le b��ton, en fonction de la distribution granulom��trique et de la composition chimique de ceux-ci. Cette th��se pr��sente un nouveau type de b��ton ��cologique �� base de d��chets de verre �� ultra-hautes performances (BEVUP) d��velopp�� �� l'Universit�� de Sherbrooke. Les b��tons ont ��t�� con��us �� l���aide de d��chets verre de particules de tailles vari��es et de l���optimisation granulaire de la des matrices granulaires et cimentaires. Les BEVUP peuvent ��tre con��us avec une quantit�� r��duite de ciment (400 �� 800 kg/m��), de FS (50 �� 220 kg/m��), de PQ (0 �� 400 kg/m��), et de SQ (0-1200 kg/m��), tout en int��grant divers produits de d��chets de verre: du sable de verre (SV) (0-1200 kg/m��) ayant un diam��tre moyen (d[indice inf��rieur 50]) de 275 ��m, une grande quantit�� de poudre de verre (PV) (200-700 kg/m��) ayant un d50 de 11 ��m, une teneur mod��r��e de poudre de verre fine (PVF) (50-200 kg/m��) avec d[indice inf��rieur] 50 de 3,8 ��m. Le BEVUP contient ��galement des fibres d'acier (pour augmenter la r��sistance �� la traction et am��liorer la ductilit��), du superplastifiants (10-60 kg/m��) ainsi qu���un rapport eau-liant (E/L) aussi bas que celui de BFUP. Le remplacement du ciment et des particules de FS avec des particules de verre non-absorbantes et lisse am��liore la rh��ologie des BEVUP. De plus, l���utilisation de la PVF en remplacement de la FS r��duit la surface sp��cifique totale nette d���un m��lange de FS et de PVF. Puisque la surface sp��cifique nette des particules diminue, la quantit�� d���eau n��cessaire pour lubrifier les surfaces des particules est moindre, ce qui permet d���obtenir un affaissement sup��rieur pour un m��me E/L. Aussi, l'utilisation de d��chets de verre dans le b��ton abaisse la chaleur cumulative d'hydratation, ce qui contribue �� minimiser le retrait de fissuration potentiel. En fonction de la composition des BEVUP et de la temp��rature de cure, ce type de b��ton peut atteindre des r��sistances �� la compression allant de 130 �� 230 MPa, des r��sistances �� la flexion sup��rieures �� 20 MPa, des r��sistances �� la traction sup��rieure �� 10 MPa et un module d'��lasticit�� sup��rieur �� 40 GPa. Les performances m��caniques de BEVUP sont am��lior��es gr��ce �� la r��activit�� du verre amorphe, �� l'optimisation granulom��trique et la densification des m��langes. Les produits de d��chets de verre dans les BEVUP ont un comportement pouzzolanique et r��agissent avec la portlandite g��n��r��e par l'hydratation du ciment. Cependant, ceci n���est pas le cas avec le sable de quartz ni la poudre de quartz dans le BFUP classique, qui r��agissent �� la temp��rature ��lev��e de 400 ��C. L'addition des d��chets de verre am��liore la densification de l'interface entre les particules. Les particules de d��chets de verre ont une grande rigidit��, ce qui augmente le module d'��lasticit�� du b��ton. Le BEVUP a ��galement une tr��s bonne durabilit��. Sa porosit�� capillaire est tr��s faible, et le mat��riau est extr��mement r��sistant �� la p��n��tration d���ions chlorure (��� 8 coulombs). Sa r��sistance �� l'abrasion (indice de pertes volumiques) est inf��rieure �� 1,3. Le BEVUP ne subit pratiquement aucune d��t��rioration aux cycles de gel-d��gel, m��me apr��s 1000 cycles. Apr��s une ��valuation des BEVUP en laboratoire, une mise �� l'��chelle a ��t�� r��alis��e avec un malaxeur de b��ton industriel et une validation en chantier avec de la construction de deux passerelles. Les propri��t��s m��caniques sup��rieures des BEVUP a permis de concevoir les passerelles avec des sections r��duites d���environ de 60% par rapport aux sections faites de BC. Le BEVUP offre plusieurs avantages ��conomiques et environnementaux. Il r��duit le co��t de production et l���empreinte carbone des structures construites de b��ton fibr�� �� ultra-hautes performances (BFUP) classique, en utilisant des mat��riaux disponibles localement. Il r��duit les ��missions de CO[indice inf��rieur 2] associ��es �� la production de clinkers de ciment (50% de remplacement du ciment) et utilise efficacement les ressources naturelles. De plus, la production de BEVUP permet de r��duire les quantit��s de d��chets de verre stock��s ou mis en d��charge qui causent des probl��mes environnementaux et pourrait permettre de sauver des millions de dollars qui pourraient ��tre d��pens��s dans le traitement de ces d��chets. Enfin, il offre une solution alternative aux entreprises de construction dans la production de BFUP �� moindre co��t.