The aim of this diploma thesis was to create an own DiffServ domain model, which is supplemented with stations generating various type of network traffic and implementation of token-bucket mechanism in router´s process model in Opnet Modeler simulation environment. DiffServ domain is made up from two edge and two core routers and includes servers and client stations generating VoIP, FTP, HTTP and database access traffic. It is described a process of distribution of traffic into different classes on edge routers of DiffServ domain along with assurance of separate handling with usage of an Assured Forwarding PHB mechanism. In point of differentiated packet processing is process model completed with generating of various statistics. The process of their creating is used to check a dropper activity, which is implemented together with token-bucket mechanism on ARP layer of the router. The functionality of the model is verified by simulation.

In those work am intent on construction hydraulic grab, his two dipper, but largely supporting frame, that is of mostly effortful. Further am suggested and drew up hydraulic perimeter for operating dipper and rotation about perpendicular axes

While free (breakpoint) chlorination is widely utilized in humanitarian water treatment, a main challenge limiting its effective application is in determining the initial dose to satisfy both health requirements and aesthetic considerations (i.e. taste and odour). International guidelines and studies showed varying recommendations for the initial chlorine dose and many did not consider chlorine decay during water transportation and storage for up to 24 hours. The main objective of this thesis is to develop a tool for humanitarian staff to accurately determine the initial chlorine dose for achieving free chlorine residual (FCR) objectives with the limited instrumentation and information in the field. The first manuscript included in the thesis gathered and evaluated seven basic chlorine decay models’ applicability in humanitarian treatment contexts. All seven models were found able to accurately describe chlorine decay in water representative of humanitarian treatment contexts with more than half of the regression resulted in R2 over 0.95. However, each model had its own limitations, which were discussed. The second manuscript involved conducting extensive chlorine decay tests in water with different characteristics, explored the relationships between the estimated chlorine decay constant and several water parameters including pH, turbidity, ultraviolet absorption at 254 nm wavelength (UVA254), temperature and 30-minute chlorine demand. It was found that the UVA254 of water followed linear and exponential relationships with the decay constant in Feben and Taras’s empirical model and that in the first order model respectively. Arrhenius-type relations were verified between the decay constant and water’s temperature. A model developed to predict FCR decay in water with known 30-minute chlorine demand accurately predicted FCR level in synthetic water (with humic acid being the main constituent) but underpredicted FCR decay in water with additional chlorine consuming matter. Further research on additional chlorine decay mechanisms are needed to expand the applicability of the model. / Graduate / 2021-04-13

No description available.

Many of today’s engineering advancements rely on minerals such as copper, gold and iron. For this reason, the mining industry plays an important role for the development of society and technological wonders. Mining excavators are commonly used tools for extracting the minerals from the mine. Mining excavators are large machines used to breakdown, penetrate and load the rock ores onto trucks that transport the minerals. During the dynamic loading, the excavator bucket experiences significant amount of wear and tear that negatively affects the production by increasing the downtime. The bucket teeth are arguably the most worn parts of the bucket and are responsible for significant amounts of downtime. This thesis aims to provide a better understanding of the load and wear on the bucket teeth of large scale mining excavators used in Bolidens Aitik copper mine in Sweden. Because of how much wear and tear the bucket teeth are exposed to, there is a need to better understand the wear behaviour of the teeth and for the whole bucket in general. This understanding can then be used to improve the service life of the teeth and other parts of the bucket and thus increase work efficiency and reduce downtime. This project was divided into two parts. The first part consisted of regular field measurements to follow the wear on the bucket for about two weeks of digging and loading. The gathered data was then analysed to provide a better understand about the wear behaviour. The second part was to develop a numerical model that could predict the wear on the bucket and could be verified by the field measurements. The field measurements consisted of seven 3D laser scans of the bucket starting with brand new teeth. At the time of the last scan, the buckets total loaded tonnage was approximately 542 kton and the excavator had operated in total of approximately 195 hours. After the raw data from the scans was gathered and analysed, various information about the wear behaviour on the teeth was achieved. The 3D scanned data was also used to provide a complete wear development cycle which allowed to track the wear of any point in the bucket. The method could also be used to create animations of the teeth as they were being worn. From the results, it was concluded that the wear rate for the teeth slowed down and even converged as the geometry changed due to wear. When comparing all nine teeth on the bucket, it was also found that the middle teeth on the bucket were most exposed to wear. The most worn tooth was found to lose around 50 kg of weight after approximately 117 operating hours, which accounts for 40 % of the original weight. The animations from the complete wear development results also showed how the individual teeth and the whole leading edge with all nine teeth were being worn as the buckets loaded tonnage increased from 0 to 542 kton. The numerical model consisted of simulations of loading with the rocks being modelled with the Discrete Element Method (DEM). These were divided into four cases, the first being with the bucket with all new teeth. The second bucket with a mixture of new and worn teeth. The third bucket with all worn teeth and then finally the fourth bucket in which a new tooth geometry was tested. The numerical model showed promising results and potential for being a reliable way to predict the wear on the bucket. The results showed that both the penetration force and wear for the middle teeth was higher than the other neighbouring teeth. It also showed that the completely worn teeth had a lower wear rate than the new teeth which is in agreement with the results from field measurements. Other factors such as tooth shape and length were also observed to have a significant impact on the wear and penetration force. Lastly, the new teeth geometry also showed potential for design improvements in terms of wear resistance but can be further optimised. From the new teeth geometry, a suggestion was given for using an existing tooth system that might be more wear resistant.

The Fourth Industrial Revolution is reshaping the manufacturing industry with the emergence of interconnectivity, smart automation, and cyber-physical systems. A popular example of cyber-physical systems is the digital twin or digital model, which both create a virtual (cyber) representation of a system. This virtual representation enables the simulation of manufacturing processes and thereby allows facilitating the understanding, optimization, planning, and prediction of the behavior of the manufacturing chain without interfering with the real system. Mining is an energy-intensive industry that can benefit from process optimization, improved production planning, and more precise material quality predictions. To accomplish this, the mined material must be tracked from its source through the mining process chain to its final destination. Because a continuous material flow cannot be tracked in the same way as a manufacturing piece can, a digital twin or model is a suitable solution for material tracking. This project is part of the effort to develop a digital model of the mining process chain and focuses on a specific mining process, the bucket-wheel stacker. A stacker is a huge machine that builds stockpiles with arriving bulk material. The digital model of the stacker must predict the stacker’s behavior in terms of spatial and temporal changes the stacker applies to the material flow. A carrier-portion model is used to digitize the material flow into discrete material portions which are transported by virtual carriers in the digital model. With the help of the forward kinematics method, the digital model utilizes a parameterized robotic model of the stacker to describe the spatial aspect of the stacker. Temporal changes are represented with simple speed-distance-duration calculations. The digital model is implemented in Java programming code and is implemented into an existing material tracking program. The results of the digital model validation show an adequate spatial accuracy of ±0.1 [m] compared to simulated and calculated values. The temporal accuracy is guaranteed to be lower than ±1 [s] compared to calculated values for certain implementation parameters. This project demonstrates that a lightweight digital stacker model for material tracking is feasible and has the potential to be expanded into a digital twin. / Den fjärde industriella revolutionen håller på att omforma tillverknings-industrin i och med framväxten av sammankoppling, smart automation och cyberfysiska system. Ett populärt exempel på cyberfysiska system är den digitala tvillingen eller digitala modellen, som skapar en virtuell (cyber) representation av ett system. Denna virtuella representation möjliggör simulering av tillverkningsprocesser och underlättar därmed förståelse, optimering, planering och förutsägelse av tillverkningskedjans beteende utan att störa det verkliga systemet. Gruvdrift är en energiintensiv industri som kan dra nytta av processoptimering, förbättrad produktionsplanering och mer exakta förutsägelser av materialkvaliteten. För att åstadkomma detta måste det utvunna materialet spåras från sin källa genom gruvprocessens kedja till sin slutdestination. Eftersom ett kontinuerligt materialflöde inte kan spåras på samma sätt som ett tillverkningsstycke, är en digital tvilling eller modell en lämplig lösning för materialspårning. Det här projektet är en del av arbetet med att utveckla en digital modell av gruvprocesskedjan, och fokuserar på en specifik gruvprocess, skovelhjulsstaplare. En staplare är en enorm maskin som bygger upp högar med ankommande bulk material. Den digitala modellen av staplaren måste förutsäga staplarens beteende i termer av rumsliga och tidsmässiga förändringar som staplaren tillämpar på materialflödet. En bärar-portionsmodell används för att digitalisera materialflödet i diskreta materialportioner som transporteras av virtuella bärare i den digitala modellen. Med hjälp av metoden forward kinematics använder den digitala modellen en parametriserad robotmodell av staplaren för att beskriva den rumsliga aspekten av staplaren. Temporala förändringar representeras med enkla beräkningar av hastighet, avstånd och varaktighet. Den digitala modellen är implementerad i Java-programmeringskod och är integrerad i ett befintligt materialspårningsprogram. Resultaten av den digital modellens valideringen visar en rumslig noggrannhet på ±0.1 [m] jämfört med simulerade och beräknade värden. Den tidsmässiga noggrannheten garanteras vara lägre än ±1 [s] jämfört med beräknade värden för vissa implementeringsparametrar. Projektet visar att en lightweight digital staplingsmodell för materialspårning är genomförbar och har potential att utökas till en digital tvilling.

No description available.

A garantia de qualidade de serviço (QoS) tem-se demonstrado muito importante em aplicações em tempo real. Este trabalho apresenta um estudo sobre Mecanismos de Policiamento na tecnologia A TM, mais especificamente, sobre o funcionamento do Mecanismo Dual Leaky Bucket, utilizado pela classe de serviço VBR em rede ATM. Para este estudo foi implementado um simulador por software do mecanismo Dual Leaky Bucket. Foram analisados dois tipos de tráfegos de vídeo com compressão MPEG-2, com pouca e muita movimentação. A partir da simulação pôde-se analisar como o erro na definição de parâmetros do contrato de QoS definidos pelo usuário no estabelecimento da conexão pode levar ao aumento na taxa de perda de informações e, conseqüentemente, a degradação da qualidade necessária pela aplicação / The guarantee of quality of service (QoS) has been demonstrating very important in real time applications. This work presents a study on Policing Mechanisms in the ATM technology, more specifically, on the operation of the Dual Leaky Bucket Mechanism, used by the class of service VBR in ATM networks. For this study a Dual Leaky Bucket mechanism simulator by software was implemented. Two kinds of MPEG-2 video traffics were analyzed with a little and a lot of movement. The simulation shows how a mistake in the definition of parameters in the QoS contract, defined by user, during of the connection establishment can leads to increase of information loss rate and, consequently, the degradation of the necessary quality for the application

Em aproveitamentos hídricos, onde podem estar envolvidas elevadas alturas de água armazenada, o vertedouro é a estrutura hidráulica responsável por conduzir com segurança o escoamento que excede a capacidade de armazenamento do reservatório. Neste aspecto, é necessário considerar o processo de dissipação de energia a fim de proteger o pé da barragem e a própria estrutura do vertedouro contra a ação erosiva da água. Este fluxo que é descarregado é usualmente amortecido por um colchão d’água, o qual é delimitado em uma bacia de dissipação projetada com intuito de resistir aos esforços impostos pelo escoamento. Em grandes barramentos, a utilização de um vertedouro tipo salto esqui, que é caracterizado por um defletor de fluxo no final de sua calha, possibilita que não haja necessidade de revestir o leito próximo do pé da barragem, pois a incidência do jato lançado ocorre distante deste local. Desta maneira, a dissipação da energia é efetuada sobre o próprio leito do rio, sendo formada uma fossa de erosão, contudo, dependendo da resistência do leito e de suas características anisotrópicas, os padrões de recirculação do fluxo podem fazer a fossa evoluir para uma situação nociva. Por isso, desde a fase de projeto desse tipo de vertedouro, monitoramento e previsões da progressão da fossa são essenciais. Então, conforme proposta deste trabalho, abordou-se cada fenômeno que influencia no potencial erosivo do jato, como a turbulência em sua emissão e o grau de difusão do mesmo no colchão d’água. Assim, com ensaios sobre modelo físico, foi possível desenvolver duas metodologias, aplicáveis tanto para a verificação da erosão de material granular na superfície de leitos, quanto para o interior de leitos rochosos fissurados, cujas forças atuantes em um bloco de rocha isolado, podem vencer seu peso submerso e o destacar da matriz. / In hydroelectric plants, which may be involved elevated heights of stored water, the dam spillway is responsible for safely flow the water that exceeds the storage capacity of the reservoir. In this respect, it is necessary to consider the process of energy dissipation in order to protect the base of the dam and the spillway structure itself against the erosive action of the water. This stream discharged is usually cushioned by a waterbed, which is bounded into a stilling basin designed with the purpose of resist the efforts imposed by the flow. In large dams, the use of a ski jump spillway type, which is characterized by a flow deflector at the end of its chute, allows no need lining the bed near the foot of the dam, since the impact of the jet is launched away this location. Thus, the energy dissipation is performed on the riverbed itself, generating a scour hole, however, depending on the resistance of the bed and its anisotropic features, patterns of flow recirculation can evolve the pit into a harmful state. For this reason, since the design phase of this type of spillway, monitoring and predicting the progression of the pit are essential. Then, according to the proposal of this work, it was dealt with each phenomenon that influences the erosive potential of the jet, as the turbulence at its issue on the air, and the level of its diffusion of on waterbed. Based on physical model tests, it was possible to develop two methodologies, applicable both for verifying erosion of granular material from the surface of the bottom, as for analyze the interior of a fissured bedrock, which the forces acting on an isolated block of rock can overcome its submerged weight and uplift it off the matrix.

Em aproveitamentos hídricos, onde podem estar envolvidas elevadas alturas de água armazenada, o vertedouro é a estrutura hidráulica responsável por conduzir com segurança o escoamento que excede a capacidade de armazenamento do reservatório. Neste aspecto, é necessário considerar o processo de dissipação de energia a fim de proteger o pé da barragem e a própria estrutura do vertedouro contra a ação erosiva da água. Este fluxo que é descarregado é usualmente amortecido por um colchão d’água, o qual é delimitado em uma bacia de dissipação projetada com intuito de resistir aos esforços impostos pelo escoamento. Em grandes barramentos, a utilização de um vertedouro tipo salto esqui, que é caracterizado por um defletor de fluxo no final de sua calha, possibilita que não haja necessidade de revestir o leito próximo do pé da barragem, pois a incidência do jato lançado ocorre distante deste local. Desta maneira, a dissipação da energia é efetuada sobre o próprio leito do rio, sendo formada uma fossa de erosão, contudo, dependendo da resistência do leito e de suas características anisotrópicas, os padrões de recirculação do fluxo podem fazer a fossa evoluir para uma situação nociva. Por isso, desde a fase de projeto desse tipo de vertedouro, monitoramento e previsões da progressão da fossa são essenciais. Então, conforme proposta deste trabalho, abordou-se cada fenômeno que influencia no potencial erosivo do jato, como a turbulência em sua emissão e o grau de difusão do mesmo no colchão d’água. Assim, com ensaios sobre modelo físico, foi possível desenvolver duas metodologias, aplicáveis tanto para a verificação da erosão de material granular na superfície de leitos, quanto para o interior de leitos rochosos fissurados, cujas forças atuantes em um bloco de rocha isolado, podem vencer seu peso submerso e o destacar da matriz. / In hydroelectric plants, which may be involved elevated heights of stored water, the dam spillway is responsible for safely flow the water that exceeds the storage capacity of the reservoir. In this respect, it is necessary to consider the process of energy dissipation in order to protect the base of the dam and the spillway structure itself against the erosive action of the water. This stream discharged is usually cushioned by a waterbed, which is bounded into a stilling basin designed with the purpose of resist the efforts imposed by the flow. In large dams, the use of a ski jump spillway type, which is characterized by a flow deflector at the end of its chute, allows no need lining the bed near the foot of the dam, since the impact of the jet is launched away this location. Thus, the energy dissipation is performed on the riverbed itself, generating a scour hole, however, depending on the resistance of the bed and its anisotropic features, patterns of flow recirculation can evolve the pit into a harmful state. For this reason, since the design phase of this type of spillway, monitoring and predicting the progression of the pit are essential. Then, according to the proposal of this work, it was dealt with each phenomenon that influences the erosive potential of the jet, as the turbulence at its issue on the air, and the level of its diffusion of on waterbed. Based on physical model tests, it was possible to develop two methodologies, applicable both for verifying erosion of granular material from the surface of the bottom, as for analyze the interior of a fissured bedrock, which the forces acting on an isolated block of rock can overcome its submerged weight and uplift it off the matrix.