Orientador: Mauro Augusto Demarzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil / Made available in DSpace on 2018-08-06T05:05:30Z (GMT). No. of bitstreams: 1 Paixao_AntonioMedeirosda_M.pdf: 9672207 bytes, checksum: e011879d8aa4447d3e547b2abf30df2a (MD5) Previous issue date: 2005 / Resumo: Este trabalho tem como objetivo o de mostrar experimentalmente a influência que os paletes de madeira podem exercer no comportamento das estruturas de armazenagem do tipo drive in com um nível de carregamento. Considerar o palete com apoios móveis em ambos os braços da estrutura, ou por outro lado, desconsiderá-lo totalmente na análise estrutural, pode resultar em análises irreais, pois o atrito entre o palete e os trilhos pode influenciar no comportamento deste tipo de estrutura. A fim de se verificar a existência desta influência em condições próximas à realidade, dois pórticos com características semelhantes às dos fornecidos pelas empresas fabricantes foram testados com a utilização de três tipos de paletes com características semelhantes às dos paletes encontrados no mercado, com inércias variadas, apoiados sobre trilhos pintados. Estes paletes foram testados sobre trilhos com mesas abrasivas a fim de se verificarem possíveis diferenças nos deslocamentos entre as estruturas carregadas com paletes sobre trilhos pintados e entre as estruturas carregadas com paletes sobre trilhos com mesas abrasivas. Além disso, os pórticos foram testados com um palete suspenso com o objetivo de simular o modelo teórico elaborado pelo Slope-deflection. Cada pórtico foi testado com as forças verticais de 245N, 490N, 735N e 980N aplicadas nos braços e com a força horizontal de 1,5% correspondente ao valor da força vertical aplicada neste pórtico para simular possíveis forças horizontais aplicadas pelas empilhadeiras na movimentação dos materiais. Dois relógios comparadores com sensibilidade de 1/1000mm e um com sensibilidade de um 1/100mm, todos com curso de 10mm, foram colocados, respectivamente, no topo e na base de cada uma das colunas de cada pórtico com o objetivo de se medirem os deslocamentos lineares e angulares destes pórticos. Os deslocamentos medidos nas extremidades de cada coluna foram úteis para se determinar os momentos fletores e as reações nas extremidades destas colunas. A influência dos paletes de madeira no comportamento das estruturas do tipo drivein foi verificada com nível de 5% de significância através da análise da variância / Abstract: This dissertation¿s intent is to investigate experimentally the influence the wood pallets exert on the behavior of the drive in storage racks with one level of loading. To consider the pallets as roller supported on both rails of the structure implies in not to consider the influence of the friction between the pallets and the rails in the behavior of the structure, and thus the results obtained by the theoretical model of analysis may lead to results that may differ from the observed in the real structure. With the aim of investigating this influence in conditions as close as possible to the reality, two frames resembling those supplied by manufacturers were tested with three sort of pallets, each one with characteristics and dimensions resembling the pallets utilized by users, but with different resistance and inertia in comparison with each other. The same pallets were tested in the same frames, but this time on rails with an abrasive surface to verify the possible differences in displacements between the structures loaded with pallets on smooth surfaces rails and between structures loaded with pallets on abrasive surfaces rails. Furthermore, the frames were subjected to a suspense load with the aim of simulating the theoretical model of analysis. Each arm were tested with vertical forces of 245N, 490N, 735N and 980N. It was considered also the horizontal force of 1,5% of the vertical force acting on the frame to take into consideration the lift truck operation. With the aim of measuring the linear and angular displacements of these frames, two dial gages were positioned at the top and one was positioned at the bottom of each column. The readings of all linear and angular displacements at the end of the columns were useful for evaluating the bending moments, the horizontal and vertical reactions acting in each one of the end of the columns of these frames. The 8 elements considered (3 pallets on smooth surface rails, 3 pallets on abrasive surface rails, 1 suspense load and 1 for the Slope-Deflection Method) were combined in groups of 3, so that the influence of the wood pallets in the behavior of drive in racks can be investigated through the variance analysis with 5% in the level of significance / Mestrado / Estruturas / Mestre em Engenharia Civil

Denna essä avser att reflektera det mellanmänskliga mötet som förutsättning för att skapa ett rum för lärande i ett organisatoriskt sammanhang. Essän utgår från ett dilemma där jag låter mötet mellan mig som pedagogisk processledare och deltagare bilda utgångspunkt för en reflektion om betingelser som avgör hur ett läranderum blir till. Jag ser min essä som ett komplement till andra studier om lärande i organisationer, studier som har sin hemhörighet i pedagogisk, psykologisk, sociologisk och i viss mån ekonomisk teoribildning. Metoden för denna essä är fenomenologisk i det att jag låter dilemmat som berättelse få träda fram på sina egna premisser. Jag låter dilemmat möta ett antal teorier om praktisk kunskap med hjälp av i första hand Aristoteles, om mötet mellan ett Jag och ett Du med hjälp av Martin Buber, mötet med den andres annanhet som en förpliktelse med hjälp av Emanuel Lévinas samt som avslutning hur frågan om mötet med den andre relaterar till kunnande-i-handling, reflektion-i-handling och att ha en skicklighet att bemästra en situation. Essän avser inte att förklara med pedagogiska eller didaktiska termer utan rör sig i ett existentiellt och filosofiskt landskap. Jag avslutar med några egna prövande slutsatser om vad som är premisser för att ett läranderum ska uppstå. Det handlar om ett genuint möte mellan ett Jag och ett Du och med varandras annanheter, vilket innebär att den praktiska kunskap som utövas inte kan ses som bara individbaserad. Den praktiska kunskapen formas i det gemensamma skeendet genom de möten som äger rum.

The goal of this thesis is to develop a concept of a casting manipulator. The manipulator is intended for manipulation of very precise casts weighing up to 2 tons. The manipulator performs rotary movement in range 90 degrees. In this thesis a strength calculation, solution of the individual structural units and necessary drawings are presented.

No description available.

[EN] The primary handling of food with robots calls for the development of new manipulation devices, especially when products are easily damaged and have a wide range of shapes and textures. These difficulties are even greater in the agricultural industry because the quality of the products is also checked during the manual handling process. This PhD dissertation provides solutions to these issues and helps to further introduce robotics into the handling of food. Several methods for handling food are included and analyzed, and specific solutions are proposed and then validated with prototypes. The research focuses on devices capable of adapting themselves to the shapes of the products without increasing the complexity of the mechanism. After analyzing several different solutions, the method chosen involves the use of under-actuated mechanisms, compliant mechanisms and fingers with pads filled with granular fluids. These fluids can behave as quasi-liquids or quasi-solids due to the jamming transition, which provides a soft initial grasp and can support high stresses during fast movements performed by the robot. The additive manufacturing process provides an opportunity to develop robot grippers that are lighter, simpler, more flexible and cheaper. By using this process elastic mechanisms are manufactured in a single part, which are equivalent to mechanisms with several rigid parts connected by joints. Laser sintering is employed to produce pneumatic actuators, with different types of motions, based on the elastic properties of the materials used in this manufacturing process. As a result, the systems can be simplified to achieve grippers, with several fingers, that are produced as a single part. In order to estimate the freshness and quality of agricultural products while they are being grasped, accelerometers are added to the fingers of several grippers. Accelerometers are economical and act as intrinsic tactile sensors. They can be easily embedded, thereby reducing the risk of getting damaged due to contact with the product, and allow each of the grasping phases to be identified. To achieve good performance of the accelerometers, a specific process is defined for the robot gripper, which touches the products a few times. In addition, several gripper prototypes are manufactured with diverse under-actuated mechanisms, jamming systems, and a new program that processes the signals from the accelerometers using different procedures in order to obtain parameters that can be used to estimate the quality of products. These parameters are correlated with data from destructive tests that are commonly used as a reference. The best performance of the accelerometers is achieved when the finger employs a granular fluid, a correlation coefficient of 0.937 being accomplished for the ripeness of mangoes and 0.872 for the firmness of eggplants. / [ES] La manipulación primaria de alimentos con robots precisa del desarrollo de nuevos sistemas de manipulación especialmente cuando los productos son sensibles al daño y presentan una amplia variabilidad de formas y texturas. En el sector agroalimentario las dificultades son aún mayores ya que la manipulación manual sirve además para inspeccionar los productos durante el proceso. Está tesis aporta soluciones a estos problemas facilitando la incorporación de la robótica. En la tesis se recopilan y analizan diversas soluciones para poder manipular alimentos proponiendo soluciones concretas que luego son validadas con prototipos. La investigación se centra en aquellos sistemas que son capaces de auto adaptarse a las formas de los productos sin incrementar la complejidad del mecanismo. Tras analizar diversas técnicas se propone el uso de mecanismos infra-actuados, mecanismos flexibles y dedos con fluidos granulares que, al estar encerrados dentro de una membrana, se comportan como cuasi-líquidos o cuasi-sólidos gracias a la transición jamming, permitiendo un agarre inicial suave y la posibilidad de transmitir esfuerzos elevados durante los movimientos del robot. En la búsqueda de garras más ligeras, sencillas, flexibles y económicas se aprovecha la oportunidad que brinda la tecnología de fabricación aditiva de material. Gracias a este proceso se fabrican mecanismos flexibles realizados en una única pieza y que equivalen a mecanismos de garras realizados con varias piezas rígidas unidos por articulaciones. Mediante el sinterizado por láser, se fabrican actuadores neumáticos, con diversos tipos de movimiento, basados en la flexibilidad del material empleado en su fabricación. En conjunto se simplifican los sistemas llegando a realizar garras flexibles de varios dedos fabricadas en una única pieza. Para evaluar la calidad y frescura de los productos agroalimentarios durante el agarre se emplean acelerómetros localizados en los dedos de varias garras. Los acelerómetros son económicos y se comportan como sensores táctiles intrínsecos, están fuera del contacto directo con el producto evitando desgastes por contacto y permiten identificar las distintas fases de agarre. Para lograr esto se desarrolla un proceso específico del robot con la garra, que palpa varias veces el producto. Se fabrican diversos tipos de garra con distintas tecnologías de mecanismos infra-actuados y sistemas jamming y se programa un algoritmo original de procesado de señal que con diversas técnicas es capaz de extraer parámetros de los acelerómetros que sirven para evaluar la calidad de los productos. Estos parámetros son correlacionados con los datos de ensayos destructivos que son habitualmente empleados como referencia. Las mejores capacidades se consiguen empleando garras con jamming lográndose coeficientes de correlación de 0.937 en índices de madurez con mangos y 0.872 en firmeza de berenjenas. / [CA] La manipulació primària d'aliments amb robots precisa del desenvolupament de nous sistemes de manipulació especialment quan els productes són sensibles al dany i presenten una àmplia variabilitat de formes i textures. En el sector agroalimentari les dificultats són encara més grans ja que la manipulació manual serveix a més per a inspeccionar els productes durant el procés. Aquesta tesi aporta solucions a aquests problemes facilitant la incorporació de la robòtica. En la tesi es recopilen i analitzen diverses solucions per a poder manipular aliments proposant solucions concretes que després són validades amb prototips. La investigació es centra en aquells sistemes que són capaços d'auto adaptar-se a la forma dels productes sense incrementar la complexitat del mecanisme. Després d'analitzar diverses tècniques es proposa l'ús de mecanismes infra-actuats, mecanismes flexibles i dits amb fluids granulars que, tancats dins d'una membrana, es comporten com quasi-líquids o quasi-sòlids gràcies a la transició jamming, permetent una prensió inicial suau i la possibilitat de transmetre esforços elevats durant els moviments del robot. En la recerca d'urpes més lleugeres, senzilles, flexibles i econòmiques s'aprofita l'oportunitat que brinda la tecnologia de fabricació additiva de material. Gràcies a aquest procés es fabriquen mecanismes flexibles realitzats en una única peça i que equivalen a mecanismes d'urpes realitzats amb diverses peces rígides unides per articulacions. Mitjançant el sinteritzat per làser, es fabriquen actuadors pneumàtics, amb diversos tipus de moviment, basats en la flexibilitat del material emprat en la seva fabricació. En conjunt es simplifiquen els sistemes arribant a realitzar urpes flexibles de diversos dits fabricades en una única peça. Per a avaluar la qualitat i frescor dels productes agroalimentaris durant la manipulació s'empren acceleròmetres localitzats en els dits de diverses urpes. Els acceleròmetres són econòmics i es comporten com a sensors tàctils intrínsecs, sense estar en contacte directe amb el producte evitant desgastos per aquest motiu, i permeten identificar les diferents fases d'prensió. Per aconseguir això es desenvolupa un procés específic del robot amb l'urpa, que palpa diverses vegades el producte. Es fabriquen diversos tipus d'urpa amb diferents tecnologies de mecanismes infra-actuats i sistemes jamming i es programa un algoritme original de processat de senyal que, amb diverses tècniques, és capaç d'extreure paràmetres dels acceleròmetres que serveixen per a avaluar la qualitat dels productes. Aquests paràmetres són correlacionats amb les dades d'assajos destructius que són habitualment emprats com a referència. Les millors capacitats s'aconsegueixen emprant urpes amb jamming assolint-se coeficients de correlació de 0,937 en índexs de maduresa amb mangos i 0,872 en fermesa d'albergínies. / Blanes Campos, C. (2016). Garras con sensores táctiles intrínsecos para manipular alimentos con robots [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68481

The aim of this study was to understand how the professional in social work handles the media scrutiny. When the media writes about social services there is seldom anything positive written about it, many social services organizations are instead heavily criticized and scrutinized by the media. When social services organizations are scrutinized by the media there is a crisis at work, and therefore should be handled as a crisis. Therefore, we describe how a crisis management might look like in an organization. The study is qualitative therefore we have interviewed four municipalities in Sweden that have been exposed by the media at a national level. We interviewed eight social workers and managers to get different opinions about the handling after media critic and scrutiny. We wanted to study how a social service handles the media when it been scrutinized, when the previous research only shows how social workers are affected by it. When the professionals in social services organization are scrutinized by the media there are frequently negative criticisms and that can lead to social services organizations legitimacy decreases. Therefor we will analyze our result from professional theory to see how the professional handles media scrutiny. We see similarities between a crisis and a media scrutiny and therefore we also use the concept of crisis. The results shows that it is important that colleagues support each other and that the professionals are open against media.  The differences between the positions are that managers are the ones who have the ultimate responsibility for the medial scrutiny. The responsibility includes media contact; to ensure that there is enough support, information regarding the situation given out to everyone in the workplace and taking into account the security.  To meet media in a better way is by have a media education there social workers and journalist can meet and exchanges knowledge and experience of each other works.

Doctor of Philosophy / Department of Animal Sciences and Industry / Michael D. Tokach / Four experiments were conducted to determine the interactive effects of dietary L-carnitine and ractopamine HCl (ractopamine) on finishing pig growth performance. In analysis of treatments common to all experiments, ractopamine increased (P < 0.01) ADG and G:F compared to pigs not fed ractopamine. Added L-carnitine tended to increase (P < 0.07) ADG and improved (P < 0.01) G:F compared to pigs not fed L-carnitine. Three experiments were conducted to determine the effects of L-carnitine and ractopamine on carcass characteristics and meat quality. In Exp. 1, drip loss decreased (linear, P < 0.04) in pigs fed increasing L-carnitine. In Exp. 2, drip loss decreased (P < 0.04) with increasing L-carnitine when fed with ractopamine. Percentage lean was higher (P < 0.01) for pigs fed ractopamine. In Exp. 3, lean percentage increased (P < 0.03) in pigs fed L-carnitine or ractopamine. Pigs fed L-carnitine tended (P < 0.06) to have decreased drip loss. These results suggest that ractopamine increases carcass leanness and L-carnitine reduces drip loss when fed in combination with ractopamine. Two experiments were conducted to determine the effects of L-carnitine and ractopamine on the metabolic response to handling. Non-gentle handling increased (P < 0.01) lactate and rectal temperature, and decreased pH. In Exp. 1, non-gentle handled pigs fed ractopamine had decreased (P < 0.01) pH and increased temperature and tended (P < 0.09) to have higher lactate than other pigs. In Exp. 2, lactate and temperature changes from immediately post-handling to 1 h post-handling were not different for pigs fed L-carnitine or ractopamine suggesting that L-carnitine did not decrease recovery time of pigs subjected to non-gentle handling or fed ractopamine. These results suggest that pigs fed ractopamine are more susceptible to stress when handled aggressively. Because carnitine did not alleviate the negative effects of handling for pigs fed ractopamine, the improvement in drip loss from feeding carnitine must be due to a different mode of action.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Mark E. Casada / Ronaldo G. Maghirang / The United States grain handling infrastructure is facing major challenges to meet worldwide customer demands for wholesome, quality, and safe grains and oilseeds for food and feed. Several challenges are maintaining grain quality during handling; reducing dust emissions for safety and health issues; growing shift from commodity-based to specialty (trait-specific) markets; proliferation of genetically modified crops for food, feed, fuel, pharmaceutical, and industrial uses; and threats from biological and chemical attacks. This study was conducted to characterize the quality of grain and feed during bucket elevator handling to meet customer demand for high quality and safe products. Specific objectives were to (1) determine the effect of repeated handling on the quality of feed pellets and corn; (2) characterize the dust generated during corn and wheat handling; (3) develop and evaluate particle models for simulating the flow of grain during elevator handling; and (4) accurately simulate grain commingling in elevator boots with discrete element method (DEM). Experiments were conducted at the research elevator of the USDA-ARS Center for Grain and Animal Health Research (CGAHR) to determine the effect of repeated handling on the quality of corn-based feed pellets and corn. Repeated handling did not significantly influence the durability indices of feed pellets and corn. The feed pellets, however, had significantly greater breakage (3.83% per transfer) than the corn (0.382% per transfer). The mass of particulate matter < 125 μm was less for feed pellets than for corn. These corn-based feed pellets can be an alternative to corn in view of their handling characteristics. Another series of experiments was conducted in the same elevator to characterize the dust generated during corn and wheat handling. Dust samples were collected from the lower and upper ducts upstream of the cyclones in the elevator. Handling corn produced more than twice as much total dust than handling wheat (185 g/t vs. 64.6 g/t). Analysis of dust samples with a laser diffraction analyzer showed that the corn samples produced smaller dust particles, and a greater proportion of small particles, than the wheat samples. Published data on material and interaction properties of selected grains and oilseeds that are relevant to DEM modeling were reviewed. Using these material and interaction properties and soybeans as the test material, the DEM fundamentals were validated by modeling the flow of soybean during handling with a commercial software package (EDEM). Soybean kernels were simulated with single- and multi-sphere particle shapes. A single-sphere particle model best simulated soybean kernels in the bulk property tests. The best particle model had a particle coefficient of restitution of 0.6; particle static friction of 0.45 for soybean-soybean contact (0.30 for soybean-steel interaction); particle rolling friction of 0.05; normal particle size distribution with standard deviation factor of 0.4; and particle shear modulus of 1.04 MPa. The single-sphere particle model for soybeans was implemented in EDEM to simulate grain commingling in a pilot-scale bucket elevator boot using 3D and quasi-2D models. Pilot-scale boot experiments of soybean commingling were performed to validate these models. Commingling was initially simulated with a full 3D model. Of the four quasi-2D boot models with reduced control volumes (4d, 5d, 6d, and 7d; i.e., control volume widths from 4 to 7 times the mean particle diameter) considered, the quasi-2D (6d) model predictions best matched those of the initial 3D model. Introduction of realistic vibration motion during the onset of clear soybeans improved the prediction capability of the quasi-2D (6d) model. The physics of the model was refined by accounting for the initial surge of particles and reducing the gap between the bucket cups and the boot wall. Inclusion of the particle surge flow and reduced gap gave the best predictions of commingling of all the tested models. This study showed that grain commingling in a bucket elevator boot system can be simulated in 3D and quasi-2D DEM models and gave results that generally agreed with experimental data. The quasi-2D (6d) models reduced simulation run time by 29% compared to the 3D model. Results of this study will be used to accurately predict impurity levels and improve grain handling, which can help farmers and grain handlers reduce costs during transport and export of grains and make the U.S. grain more competitive in the world market.

Published Article / This paper investigates the challenges of employing Van der Waals forces in micro-material handling since these forces are dominant in micro-material handling systems. The problems include the creation of a dust-free environment, accurate measurement of the micro-force, and the efficient picking and placing of micro-work pieces. The use of vacuum suction, micro-gripper's surface roughness, geometrical configuration and material type are presented as alternatives to overcome the challenges. An atomic force microscope is proposed for the accurate measurement of the Van der Waals force between the gripper and the micro-work piece.

Published Article / This paper explores the manipulation of Van der Waals' forces by geometrical parameters in a micro-material handling system. It was observed that the flat-flat interactive surfaces exerted the highest intensity of Van der Waals' forces followed by cone-flat, cylinder-flat, sphere-flat and sphere-sphere interactive surfaces, respectively. A conical micro-gripper proved to be versatile in manipulating the Van der Waals' forces efficiently in a 'picking up' and 'releasing' mechanism of micro-work parts. It was deduced that the pick-up position should be rough and spherical, and the placement position should be smooth and flat for an effective 'pick-and-place' cycle to be realised.