Auswahl der wissenschaftlichen Literatur zum Thema „Industrial applications“

Ce projet s’est focalisé sur l’ajout de nouvelles propriétés à des papiers grâce à l’utilisation de nanocelluloses fonctionnelles. Ces nanocelluloses sont des nanoparticules extraites du bois qui peuvent être divisées en deux catégories : les nanofibrilles de cellulose (CNFs) et les nanocristaux de cellulose (CNCs). Ce travail s’est essentiellement penché sur l’utilisation des CNFs. Leur réactivité chimique a été utilisée afin de les fonctionnaliser avec des organotrialkoxysilanes. C’est aussi leur fort enchevêtrement ainsi que la grande viscosité de ces CNFs en suspension qui ont été utilisés afin de synthétiser des petites particules de silsesquioxane pour rendre le matériau final antimicrobien et (super)hydrophobe. Les connaissances obtenues à travers l’étude sur des films modèle de CNFs ont ensuite été appliquées au couchage du papier. Ces CNFs fonctionnelles ont donc été évaluées pour le développement d’un papier possédant une surface antimicrobienne, anti-adhérente, barrière aux graisses ou superhydrophobe<br>The aim of this work is to implement new properties to a paper based material via the use of functional nanocelluloses. Nanocelluloses are nanoparticles extracted from wood and distinguished in two categories: Cellulose Nanofibrils (CNFs) and Cellulose Nanocrystals (CNCs). This work has only been carried out with CNFs. The chemical reactivity of CNFs was used to functionalize them with organotrialkoxysilanes. The entangled network and highly viscous suspension of CNFs was also used to synthesize silsesquioxane particles with limited size to impart (super)hydrophobic and antimicrobial properties. Knowledge obtained through the study of model CNFs films was then applied to paper based material coating. The functional CNFs were evaluated for its use in an antimicrobial, anti-adherent, greaseproof or superhydrophobic paper surface

In the manufacturing industry, the request of complex products and the decreasing of production time have led to more and more sophisticated CNC-controlled multi-axis machines. Often their setup process is affected by different mistakes caused by the persons responsible that lead to collisions inside the working area. Those collisions often lead to damage the tool and the work piece. The thesis deals with this problem, providing new insights for a fast and robust collision detection. Imagining to start from scratch, through a dynamic analysis of the impact in a mechanical transmission, we reached to identify the sensors which provide the optimal trade-off between the quality of impact information measured, feasibility and costs. Then, we propose two new collision detection algorithms able to identify the unwanted event as fast as possible, with the goal to reduce the impact force and containing the damage. Furthermore, their performance are compared with the most successful algorithm found in literature on two different mechanical systems: a heavy automatic access gate and the laboratory’s robotic arm.

Since the discovery of vulcanization, rubbers have invaded our life and nowadays occupie a significant place in the industrial world. In fact, in most applications there are no alternative materials to them. Despite what it could be thought, a rubbery object is a very complex system. In fact, it is generally based on only one or more rubbers and on several other additives, such as reinforcing fillers, plasticizers, antidegradants, vulcanizing agents. Different production phases are required to realized a rubbery product. The first is the rubber compounding with the additives, which occurs at a defined temperature for a fixed time. The dispersion degree achieved by the fillers in the elastomeric matrix and consequently the final product properties are strictly dependent on this first step of production. After the mixing, the forming operations follow: the compound will retain the shape imposed. Finally, vulcanization process provides the material its ‘elastic’ recovery behaviour. The final properties of a rubber product depend mainly on the type of rubber chosen, however they can be further manipulated by varying the additives used and their concentrations, and the processing steps. The special character of rubber, being a multicomponent system, and the complexity of the production phases delayed the study and the development of rubber nanocomposites, in respect to the polymeric ones. However, in the ten past years, the reports published that deal with rubber nanocomposites have been raise. The ongoing R&D interest is mostly due to the significant physico-mechanical properties improvement which is observed when the nanoclays are added to a rubber matrix. This enhancement depends on the nanometric-scale dispersion that the nanoclays can achieve in the compound; contrary to the conventional fillers, such as carbon black and silica, which carry out a micrometric-scale dispersion. Nowadays, the nanoclays are the most studied nano-sized fillers because there are easily available in nature and cheap. Several research works have demonstrated that the addition of even low amounts of layered nanofillers (< 10 wt.%) improves the mechanical properties, decreases gas permeability and swelling in solvents, increases thermal endurance and flame resistance. This PhD activity was financed by the company “IVG Colbachini” placed in Cervarese Santa Croce, Padova. The company, for over 40 years, has been involved in the production of industrial rubber hoses to convey powders, granular, liquid or gas materials. The “IVG Colbachini” products are used in different sectors, such as food, chemical, agricultural, construction, rail, naval and steel industries. The thesis work was aimed at the study and the optimization of rubber compounds produced in “IVG Colbachini”. This thesis consists of 6 chapters and subsequently the main topics dealt with in each chapter will be concisely summarized. Chapter 1 highlights the significant differences between a conventional composite and a nanocomposite, giving also a classification of this latter class of materials. In addition, it explains which filler features are the most important to obtain a nanocomposite and how each of these can influence the final product properties. In Chapter 2 nanoclays and rubber nanocomposites loaded with layered fillers are introduced. Particularly, the chemical structure of these latter and the organo-modification importance are described. In addition there is a summary of the rubber/clay nanocomposite synthesis methods and their characteristic properties present in literature, such as mechanical performance, barrier effect and flame resistance. Chapter 3 explains step by step the art of rubber compounding. In particular, the concept of recipe and how it is indicated are introduced. Types, features and functions of recipe diverse ingredients are specified. In addition, the different processing steps are described, starting from the component mixing, proceeding with the forming, until to the vulcanizing. Finally, some applications of rubber products are summarized. Chapter 4 deals with materials used for the formulations subject of this thesis, experimental procedures and characterization techniques applied. Chapter 5 is devoted to tests carried out on an ethylene vinyl acetate based rubber compound, with the aim to improve its flame retardant properties. The obtained results are indicated and some whose interpretations are presented. Chapter 6 surveys the mechanical performances of a natural rubber/polybutadiene blend. Particularly, the experimental data obtained from the rubber compounds filled with conventional fillers, such as silica and carbon black, are compared with the ones found for the rubber compounds loaded with innovative fillers, like the nanoclays.<br>Dopo la scoperta del processo di vulcanizzazione, le gomme hanno invaso la nostra vita e attualmente occupano un posto significativo nel mondo industriale tanto che per molte applicazioni non ci sono materiali alternativi ad esse. A differenza di quanto si potrebbe pensare, un oggetto di gomma è una sistema piuttosto complesso. Infatti, esso è in genere costituito da uno o più elastomeri e da molti altri additivi, quali ad esempio cariche rinforzanti, plastificanti, antidegradanti, agenti vulcanizzanti, etc. La realizzazione di un prodotto finito in gomma prevede una serie di operazioni. La prima di queste prevede la miscelazione dell’elastomero/i con diversi additivi ad una specifica temperatura per un tempo prefissato. Tale operazione è significativa nel determinare il grado di dispersione degli additivi nella matrice, influenzando quindi le proprietà del prodotto finale. Successivamente si verifica l’operazione di formatura durante la quale viene data una forma definita alla mescola. Infine con il processo di vulcanizzazione l’oggetto acquisisce la caratteristica proprietà di ritorno elastico, tipica delle gomma. Le proprietà finali di un prodotto di gomma dipendono innanzitutto dall’elastomero di partenza, tuttavia possono essere ampiamente manipolate variando la tipologia e la concentrazione degli additivi aggiunti e le fasi di lavorazione. Il fatto di essere un sistema multicomponente e la complessità delle fasi di produzione sono i motivi principali che hanno ritardato lo studio e lo sviluppo dei nanocompositi a base elastomera rispetto a quelli polimerici. Tuttavia, negli ultimi dieci anni il numero dei lavori scientifici sui nanocompositi elastomerici è ampiamente aumentato. Il continuo interesse deriva dal notevole miglioramento delle proprietà fisico-meccaniche che si osserva quando additivi nanodimensionali sono introdotti in una matrice elastomerica. Il miglioramento ottenuto dipende dalla dispersione a livello nanometrico che tali riempitivi possono raggiungere, contrariamente ai più comuni silice e nero fumo che si disperdono su scala micrometrica. Ad oggi, le nanocariche maggiormente studiate per la loro disponibilità in natura e il basso costo sono le nanoargille. Numerosi studi hanno dimostrato che l’aggiunta di piccole quantità di silicati a strati (< 10 wt.%) migliora le proprietà meccaniche, riduce la permeabilità ai gas e il rigonfiamento in solventi, aumenta la stabilità termica e la resistenza alla fiamma. La borsa di studio di questo dottorato è stata finanziata dalla ditta “IVG Colbachini” di Cervarese Santa Croce, Padova. L’azienda, da più di 40 anni, realizza tubi industriali in gomma per la conduzione di polveri, granuli, gas, liquidi. I prodotti di “IVG Colbachini” trovano applicazione nei settori più diversi, tra i quali l’industria chimica e agro-alimentare, l’edilizia, la cantieristica navale e da diporto, le apparecchiature ferroviarie, le lavorazioni dei metalli. Il lavoro di tesi svolto è stato dedicato allo studio e all’ottimizzazione di mescole elastomeriche prodotte in “IVG Colbachini”. Questa tesi consta di 6 capitoli e di seguito saranno riassunti brevemente gli argomenti principali trattati in ciascun capitolo. Il Capitolo 1 evidenzia le differenze sostanziali tra composito convenzionale e nanocomposito, fornendo anche una classificazione di quest’ultima categoria di materiali. Inoltre spiega quali caratteristiche di un filler sono di fondamentale importanza per la realizzazione di un nanocomposito e come ciascuna di esse influenzi le proprietà del materiale finale. Nel Capitolo 2 è contenuta una presentazione delle nanoargille e dei nanocompositi elastomerica additivati con filler a strati. In particolare si descrivono la struttura chimica di quest’ultimi e l’importanza del modificante organico. A questo si aggiunge un quadro dei metodi di sintesi di questi nanocompositi e delle loro proprietà tipiche riportate in letteratura, quali le prestazioni meccaniche, l’effetto barriera ai gas e la resistenza alla fiamma. Il Capitolo 3 illustra passo passo l’arte della lavorazione della gomma. In particolare si introduce il concetto di “ricetta elastomerica” e come viene in genere espressa. Vengono specificate le tipologie, le caratteristiche e le funzioni dei diversi componenti di una “ricetta”. Inoltre si descrivono le varie fasi di produzione di un oggetto in gomma, partendo dalla miscelazione degli ingredienti, passando per la formatura, arrivando fino al processo di vulcanizzazione. In questo capitolo vengono infine riportate alcune possibili applicazioni di prodotti in gomma. Nel Capitolo 4 si introducono i materiali impiegati per la produzione delle formulazioni, oggetto di questo lavoro di tesi, le procedure sperimentali e le tecniche di caratterizzazione utilizzate. Il Capitolo 5 illustra le prove condotte su una mescola elastomerica a base di etilene vinil acetato, con lo scopo di migliorarne le proprietà di resistenza alla fiamma. Vengono quindi riportati i risultati ottenuti e proposte alcune interpretazioni di essi. Nel Capitolo 6 ci si è concentrati sullo studio delle proprietà meccaniche di un blend costituito da gomma naturale e polibutadiene. In particolare, i dati sperimentali ottenuti da mescole contenenti riempitivi tradizionali, come silice e nero fumo, sono stati confrontati con quelli ricavati da compound con filler innovativi, quali le nanoargille.

In recent years there has been a growing attention from the world of research and companies in the field of Machine Learning. This interest, thanks mainly to the increasing availability of large amounts of data, and the respective strengthening of the hardware sector useful for their analysis, has led to the birth of Deep Learning. The growing computing capacity and the use of mathematical optimization techniques, already studied in depth but with few applications due to a low computational power, have then allowed the development of a new approach called Reinforcement Learning. This thesis work is part of an industrial process of selection of fruit for sale, thanks to the identification and classification of any defects present on it. The final objective is to measure the similarity between them, being able to identify and link them together, even if coming from optical acquisitions obtained at different time steps. We therefore studied a class of algorithms characteristic of Reinforcement Learning, the policy gradient methods, in order to train a feedforward neural network to compare possible malformations of the same fruit. Finally, an applicability study was made, based on real data, in which the model was compared on different fruit rolling dynamics and with different versions of the network.

Abstract The amount of digital data surrounding us has exploded within the past years. In industry, data are gathered from different production phases with the intent to use the data to improve the overall manufacturing process. However, management and utilization of these huge data sets is not straightforward. Thus, a computer-driven approach called data mining has become an attractive research area. Using data mining methods, new and useful information can be extracted from enormous data sets. In this thesis, diverse industrial problems are approached using data mining methods based on similarity. Similarity information is shown to give an additional advantage in different phases of manufacturing. Similarity information is utilized with smaller-scale problems, but also in a broader perspective when aiming to improve the whole manufacturing process. Different ways of utilizing similarity are also introduced. Methods are chosen to emphasize the similarity aspect; some of the methods rely entirely on similarity information, while other methods just preserve similarity information as a result. The actual problems covered in this thesis are from quality control, process monitoring, improvement of manufacturing efficiency and model maintenance. They are real-world problems from two different application areas: spot welding and steel manufacturing. Thus, this thesis clearly shows how the industry can benefit from the presented data mining methods.

The use of low-power wireless sensors and actuators with networking support in in-dustry has increased over the past decade. New generations of microcontrollers, new hardware for communication, and the use of standardized protocols such as the Internet Protocol have resulted in more possibilities for interoperability than ever before. This in-creasing interoperability allows sensors and actuator nodes to exchange information with large numbers of peers, which is beneficial for creating advanced, flexible and reusable systems.The increase in interoperability has resulted in an increase in the number of possible attacks from malicious devices or users. For this reason, the use of encryption techniques to protect client and server communications has become mandatory. However, even with state-of-the-art encryption mechanisms, there is no protection that can control access to each particular service with fine-grained precision. The nodes within an industrial network of wireless sensors and actuators are resource-constrained embedded devices, and increasing interoperability therefore requires a higher level of computation capabil-ities. The nodes’ intrinsic limitations of memory and processing exert an adverse effect on power consumption and communication delays, resulting in a shorter battery life-time. Therefore, the standard computing solutions for Internet communications are not directly applicable, and new mechanisms to achieve security, scalability, dependability, interoperability and energy efficiency are needed.Sensor and actuator networks can transmit sensed data, but they also offer access to the actuators. Such accesses, presumably provided via services, require an access protection scheme. For this reason, the use of access control mechanisms is mandatory. Access control assists in the creation of customized services and access policies. These access policies can isolate access permissions to devices with different roles, such as production and maintenance.The main contribution of this thesis is a novel, efficient IoT framework for industrial applications, including design, implementation, and experimental validation. The frame-work includes features for communication protection, authentication, fine-grained access control, zero-configuration networking, and run-time reconfiguration. These technologies and their corresponding energy consumption data clearly demonstrate the feasibility of integrating a battery-operated IoT concept into a functional System of Systems. The provided data also pinpoint the most critical areas for improvement.

Augmented reality (AR) is a way of overlaying digital information onto a picture or a videofeed and has been used in industrial contexts for more than 20 years. This Master's Thesis examines if AR can be used to help maintenance engineers set up and maintain robot environments by visualizing robot movement and safety zones. The main result of the Master's Thesis is a prototype application for a tablet computer. The user points the tablet towards a robot filming it and the video feed is displayed on the screen. This video feed is augmented with a virtual zone displayed around the robot, illustratingthe area where the robot is allowed to move. The application fetches the coordinatesfor the zone from the safety system SafeMove { a system designed by ABB to increase safetyand allow closer human-robot collaboration.The visualization of a SafeMove conguration is currently limited to an image of atwo-dimensional coordinate system showing the zone as a set of dierent coordinates. Thismakes it dicult grasping the full layout of the three-dimensional zone. By using theapplication the user gets a better view of the layout, allowing the user to look at the robot from different sides and see the safety zone projected around the robot. User tests show that people working with SafeMove could benefit from using the application to verify the conguration of SafeMove systems and the conclusion is that AR, if used right, greatly can improve robot interaction and maintenance.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2000.<br>Includes bibliographical references (p. 187-198).<br>Photonuclear resonance excitation refers to a variety of photonuclear interaction processes that lead to the excitation of a nucleus from some initial state to a higher energy nuclear state. Typical excited nuclear state lifetimes are short, ranging from nanoseconds to femtoseconds or less; however, some isotopes have unusually long-lived excited nuclear energy states, or isomers. This dissertation examines the feasibility of using bremsstrahlung irradiation sources to produce isomers for industrial applications. In contrast with charged particle based isomer production, the use of high energy photons allows for the irradiation and production of isomers in bulk materials. The commercial availability of reliable, high power industrial electron accelerators means that isomer activities sufficient for industrial applications may be achieved using bremsstrahlung, in contrast with neutron based approaches where suitable neutron sources of sufficient intensity for these applications are lacking. In order to design a system for creating nuclear isomers using photons, the resonant photon absorption isomeric excitation cross section must be known. Unlike neutron absorption and scattering cross sections, comparatively little information exists for photon isomeric excitation. To address this, a theoretical model based upon statistical probability distributions of nuclear energy levels has been developed for calculating photon excitation cross sections at energies below neutron and proton binding energies; the ideal region of operation for most applications in order to minimize long term activation of materials. Isomeric excitation cross sections calculated using this technique have been compared with experimentally measured values and are found to agree to within a factor of two or better.<br>(cont.) sing this, a general transition equation suitable for both nuclear resonance fluorescence and isomer excitation has been developed for calculating nuclear level distribution probabilities for materials undergoing photon irradiation. Experiments have been carried out using an industrial 6 MeV electron accelerator to identify obstacles related to nuclear resonance fluorescence measurements as well as measurements of the decay of short-lived isomers using scintillators in the vicinity of high intensity bremsstrahlung sources. Use of a fast switching gating circuit in combination with a pulsed accelerator was found to be a satisfactory solution for dealing with problems related to the performance of a detectors photomultiplier tube as a result of exposure to scattered radiation during the beam pulse. Calculations have been carried out to assess the performance characteristics which could be expected from industrial photonuclear resonance excitation systems, based upon a 10 MeV electron accelerator. For simple isomer production, specific activities on the order of 1 mCi/g/mA can be expected for irradiation periods sufficiently long for equilibrium to be reached. For the analysis of arsenic concentrations in environmental samples, sensitivities of 1 +/- 0.1 ppm could be achieved using accelerator currents of 50 - 100 [mu]A with irradiations times of a few minutes or less. A system designed to analyze ore traveling along a conveyor belt could be used to sort gold ore based upon a lower grade cutoff of 5 ppm using an accelerator of 10 mA ...<br>by David Lee Chichester.<br>Sc.D.