Cement penetrability is a key factor in multifilament cement composites. However, the modes of action and the concepts vary because of brittle and ductile fibers. In the case of brittle fibers such as glass, high penetrability of cement products in between the bundle filaments can lead to brittle composite behavior, and therefore addition in ductility is required. In order to have efficient bundle action and high bonding, fillers can be introduced in between the glass filaments, keeping the telescopic mode of failure but at the same time improving the bond and stress transfer within the filaments of the bundle, even at late ages, resulting in a ductile and high strength composite. On the other hand, ductile fibers such as polypropylene (PP), which also developing low bonding with the cement matrix, result in ductile cement composite but with relatively low strength. Therefore, in this case good penetrability of the cement in between the filaments of the bundle is essential in order to maximize the reinforcing efficiency of the bundle by improving bond. The penetrability of the matrix into a fabric structure and especially in between the bundle filaments made up the fabric is a result of fiber- matrix compatibility, which depends on: level of opening and spaces between the filaments, bundle surface properties including wetting and chemical affinity to the cement matrix, matrix viscosity, processing of the composite, and the nature of the fabric junctions and the resulting tightening effects of the bundle, i.e., influenced by the fabric structure itself.

Alkenes are remarkably versatile motifs as they can be further functionalized by a vast array of addition, reduction, and oxidation reactions. Thus their efficient synthesis is highly desired. Over the past 35 years, the Suzuki-Miyaura cross-coupling reaction has emerged as a powerful synthetic tool for the formation of carbon-carbon bonds. Herein is described the development of a one-pot two-step protocol for the synthesis of (E)-alkenes comprising palladium-catalyzed Suzuki-Miyaura cross-coupling of aryl or heteroaryl halides, including chlorides, with alkenyl pinacolboronates, prepared in situ via solvent-free zirconium-catalyzed hydroboration of terminal alkynes. Avoiding isolation of intermediates saves time and reduces waste. The regio- and stereochemistry of the alkene is set by initial hydrozirconation of the alkyne. Addition of water to the second step deactivates the zirconocene catalyst, which is otherwise deleterious to cross-coupling. Thus this sequence exploits the water tolerance of the Suzuki-Miyaura reaction.

Alkenes are remarkably versatile motifs as they can be further functionalized by a vast array of addition, reduction, and oxidation reactions. Thus their efficient synthesis is highly desired. Over the past 35 years, the Suzuki-Miyaura cross-coupling reaction has emerged as a powerful synthetic tool for the formation of carbon-carbon bonds. Herein is described the development of a one-pot two-step protocol for the synthesis of (E)-alkenes comprising palladium-catalyzed Suzuki-Miyaura cross-coupling of aryl or heteroaryl halides, including chlorides, with alkenyl pinacolboronates, prepared in situ via solvent-free zirconium-catalyzed hydroboration of terminal alkynes. Avoiding isolation of intermediates saves time and reduces waste. The regio- and stereochemistry of the alkene is set by initial hydrozirconation of the alkyne. Addition of water to the second step deactivates the zirconocene catalyst, which is otherwise deleterious to cross-coupling. Thus this sequence exploits the water tolerance of the Suzuki-Miyaura reaction.

No description available.

The report is about reducing the Eigen weight of a reach stacker in order to obtain decreased fuel consumption. The detail the product development treats is the telescopic boom. By using steel of higher strength the dimension can be decreased, which in turn results in a reduced weight. Suitable steel for the application might be the high strength structural steel of designation S690QL. With support of calculations and CAD simulations the possible weight reduction is assumed to amount to 28%.

Observando-se as diversas aplicações de robôs na área de serviços é possível perceber uma crescente busca por manipulação de ferramentas em lugares elevados utilizando dispositivos robóticos, visto que tais tarefas exigem a utilização de diversos equipamentos de segurança e apresentam um alto risco à presença humana. Os exemplos mais comuns desse tipo de tarefa são: inspeção de: máquinas de grande porte, tanques de armazenamento, silos, postes, linhas de transmissão e distribuição de energia elétrica, etc. Com o intuito de aplicar robôs a essas tarefas, e consequentemente aumentar a segurança e eficiência dessas operações, foi realizado, primeiramente neste trabalho, um estudo sobre as classes de robôs manipuladores existentes. Para tanto adotou-se uma classificação que separa os robôs de acordo com o número de juntas, o que gera uma divisão em três diferentes grupos, robôs discretos, robôs do tipo serpente e robôs contínuos. Ao analisar as três classes, observa-se que os robôs contínuos possuem mais graus de liberdade que os outros grupos, apresentando como estrutura uma coluna vertebral continuamente deformável, que em oposição aos tradicionais manipuladores robóticos elo/junta/elo, possuem mecanismos mais simplificados, controle menos complexo devido ao menor número de atuadores e podem interagir com obstáculos encontrados em seu ambiente sem criar grandes forças de contato. Ao utilizar configurações extrínsecas, ou seja, posicionando os atuadores fora da estrutura do robô, e transmitindo o movimento utilizando cabos, é possível construir robôs com alta isolação elétrica, o que é de grande utilidade para operações que envolvem tarefas nas proximidades de redes elétricas de alta tensão. Apesar das diversas vantagens, não foram encontradas na literatura aplicações de robôs contínuos na realização de tarefas em alturas elevadas. Levando em consideração as vantagens oferecidas pelos robôs contínuos, este trabalho propõe o estudo e a aplicação de um robô do tipo contínuo que possua uma arquitetura mais adequada para realizar trabalhos a alturas elevadas. Com o intuito de demonstrar as vantagens oferecidas por essa arquitetura, será realizado um estudo de caso no qual o objeto a ser inspecionado são as cruzetas de madeira em postes de distribuição de energia elétrica. Em uma segunda etapa, elabora-se o projeto mecânico do robô contínuo proposto, onde são detalhados os mecanismos propostos e são feitas simulações utilizando o método dos elementos finitos para analisar o comportamento da estrutura quando submetida a carregamentos. Em uma terceira etapa, adotando-se uma estratégia de controle seqüencial é elaborado o projeto de controle. Em uma ultima etapa, com o intuito de analisar o funcionamento do robô é construído um protótipo, com o qual são feitos os testes. / Among several applications of robots in the service field, it is possible to percept an increasing interest in manipulate tools in higher positions using automatic devices, due to the fact that such activities are high risked operations and demands the use of several safety equipments. The most common examples of this kind of activity are the inspection of machines, silos, electrical distribution poles, etc. With the aim of apply robots to these activities and increase the safety and efficiency in these operations, as a first step in this work is done the study of different kinds of manipulators. Adopting a classification based on the number of joints, it is possible to separate robots in three different classes: discrete robots, snake-like robots and continuum robots. By analyzing these classes, it is possible to say that continuum robots have more degrees of freedom than the robots of others groups; Compared with the classic discrete robots, continuum robots have simplified mechanisms, simpler control scheme due to the small number of actuators and, in the case of an obstacle, they can contour the obstacle without generating high contact forces. By positioning the actuators out of the robot structure and transferring the motion using cables, i.e., adopting an extrinsic actuation, it is possible to build continuum robots with high electric insulation that is important in applications in which the robot must work near of an electrical distribution network. Despite these advantages, no previous works concerning the use of continuum robots to work in higher positions were found in the literature. Considering the advantages offered by continuum robots, this work proposes a study and application of a continuum robot that uses a more suitable architecture to work in higher positions. Aiming to demonstrate the advantages provided by this architecture, It will be used a case study, in which, the object to be inspected is the wood cross-arms of an electrical poles used in the electrical distribution networks. In a second step, it is done the mechanical project of the robot, where the proposed mechanisms are explained and structural simulations using the finite element method are performed in order to analyze how the structure would react to loads. In a third step, by adopting a strategy of sequential control, it is done the control project. In the last step, with the aim of analyze the robot in practical situation, a prototype is built, which is used to perform the tests.

The aim of this thesis is to investigate the force loading of the front telescopic fork girder of the motorcycle and its impact on the structure of the girders. The force effect in fork storage is solved by a mathematical model in Adams View based on calculated and experimentally determined parameters. Managed to gather a series of data and parameters of the Triumph Daytona 955i. The created model achieves high accuracy in terms of motorcycle kinematics. The benefit of this work is to get an overview of the forces acting in the suspension of the front wheel of the motorcycle.

This thesis deals with product design rotating camera crane with variable length telescopic arm. Proposed maximum arm length is 6 [m] with a maximum weight capacity of the camera 8 [kg]. The work deals with the various structural units associated mainly with the issue of the telescopic arm. In individual sections detail the construction of the camera head developed deformation and stress analysis of a telescopic jib.

This master's thesis makes a brief comparison of design variants of cranes for general use on the deck of a vessel. Further, this thesis deals with a design of a crane with a telescopic jib and a single knuckle. An important part of the crane’s design is its kinematic solution, which was modified in the design phase. The last step of a simplified analytical calculation of the jib for design steel construction is given. This preliminary calculation is the starting point for a FEM model and for the following FEM analysis. A stress control is made according to the Lloyd's Register of Shipping agency’s standard for lifting appliances in marine environment and also according to the recommendations of Huisman company. A part of the proposed solution is a selection of main components of the crane. The master’s thesis contains a summary of some operational and other information which characterize possibilities of the crane’s use. This thesis also includes source materials for drawing documentation.

No description available.