Sandvik Coromant och deras kunder har maskiner inom skärande bearbetning som genererar data vid produktion. Nyttolasten av det data som genereras innehåller olika mätvärden från sensorer inuti maskinen samt händelser som sker i maskinen under produktion. I det här arbetet har insamlad data från maskiner använts för att försöka öka maskinernas produktivitet genom att bistå tekniker och maskinoperatörer med relevant information. För att förmedla informationen utvecklades ett mjukvarusystem som analyserar och visualiserar maskindata. Dataanalysen gjordes med hjälp av artificiell intelligens som tränades på sekventiell data för att prediktera verktygsbrott. Vid identifikation av en datasekvens som potentiellt kan leda till ett verktygsbrott, meddelas maskinoperatören via en mobilapplikation installerad på en portabel enhet. Datavisualiseringarna består av interaktiva linjediagram och tidssorterade listor av maskinhändelser. De interaktiva linjediagrammen är tvådimensionella och visar mätvärden med sitt ursprung från någon maskins sensorer längs y-axeln och tiden längs x-axeln. Interaktiviteten som finns tillgänglig för användare i linjediagrammen är zoomning, panorering samt klickbara datapunkter. / Sandvik Coromant and their customers have cutting machines that generate data during production. The payload of the data generated contains various measurement values from sensors inside the machineas, well as events that occur in the machine during production. In this work, the data collected from the machines has been analyzed to try to increase the machines’ productivity by assisting technicians and machine operators with relevant information. To communicate the information, a software system was developed that analyzes and visualizes machine data. The data analysis was done using artificial intelligence trained on sequential data to predict tool failure. When identifying a data sequence that could potentially lead to a tool failure, the machine operator is notified via a mobile application installed on a portable device. The data visualizations consist of interactive line charts and time-sorted lists of machine events. The interactive line diagrams are two-dimensional and show measurement values originating from any machine's sensors along the y axis and time along the x axis. The interactivity available to users in the line graphs is zooming, panning, and clickable data points.

In comminution machines, the product properties (particle size distribution, mineral liberation characteristics) and process consumables (energy for size reduction, wear) are affected by various parameters. On the one hand, understanding and optimizing these parameters can provide an energy efficient process and a specified product. On the other hand, a fundamental understanding of the breakage process can even be used for designing new or improved comminution machines. In this thesis, breakage fundamentals are analyzed and set against the principles of various comminution machines. The study of the breakage fundamentals is crucial for a better understanding of the effect of different comminution environments on ore types and their textures in order to achieve a desired product size and liberation. This work defines three main areas of breakage processes with breakage fundamentals, namely “loading mechanism”, “breakage mechanism” and “breakage mode”. The “loading mechanism” is defined as the physical action that is applied to a particle or several particles in order to introduce mechanical stress. The resulting pattern of the particle failure is named “breakage mechanism”. Finally, the “breakage mode” defines the particle breakage in terms of being random or non‐random. Non‐random breakage depends on the ore texture, which can be categorized as preferential breakage and phase boundary breakage. Promoting the breakage mode to the phase boundary breakage could help to increase the liberation degree. Various studies have assessed the effect of ore texture and operational parameters on mineral liberation. While ore texture is related to the particle inherent characteristics, operational conditions such as loading mechanism are related to the comminution environment. In all these investigations, little attempt has been made to explore the combined effects of loading mechanism and quantitative ore texture features on breakage mode and mineral liberation. In addition, a lack of fundamental understanding of the breakage process and mineral liberation can be seen. Accordingly, a more fundamental study of the causes behind the effects of loading mechanism and texture is required in order to optimize the comminution process in terms of mineral liberation. The objective of this work is, therefore, to investigate the effects of different loading mechanisms on particle breakage and breakage mode. In order to achieve this goal, work has started with using two methods including three‐dimensional deformation and two‐dimensional crack quantification. The former method involved X‐ray computed micro‐tomography (XCT) imaging and Digital Volume Correlation (DVC) measurements which determiners the breakage mode in terms of being random or non-random. Whereas the latter was done using an image processing code in MATLAB to quantify cracks in terms of random and non-random breakage (preferential or phase boundary) from Scanning Electron Microscopy (SEM) images. In addition, XCT 3D imaging was used in order to track the propagated cracks in the third dimension. Moreover, phase boundary breakage in magnetite grains was studied qualitatively based on optical microscopy images in order to identify and characterize the propagated cracks.

Tailings storage facilities (TSFs) serve as structures for storing tailings, i.e., waste materials generated by the mining industry. In recent years, tailings dam failures and collapse of these constructions have been reduced due to the establishment of regulations to control these structures, nevertheless, the consequences are catastrophic when tailings dam failures occur. There are some different construction methods for tailings dams. One common construction method is the upstream method; where the dam is raised by constructing embankments on top of the tailings stored in the impoundment. Thus, it is essential to understand the mechanical and geochemical behavior of deposited tailings to be able to perform safety assessments of tailings dams.  Material properties must be assessed for the present time as well as over a longer time since aging and continuous deposition might change the mechanical behavior over time. Continuous deposition leads to continuous increased vertical stress on particles, and there is a need to study if increased vertical stress can lead to a possible change of the mechanical properties of tailings. Therefore, this study has investigated the characteristics of tailings particles after being subjected to vertical stepwise loading. This study focuses on investigating the impact of particle breakage (or crushing) on tailings by analyzing material recovered from a tailings dam in Sweden. The research was performed on disturbed tailings material from a borehole of approximately 40 m depth. The study was conducted on four samples recovered 10 m apart, developing a characterization of the material and laboratory tests on each of them. The characterization consisted of the determination of intrinsic properties such as particle size distribution, particle shape, and mineralogy before and after testing; while the laboratory tests were conducted by means of the odometer test. The laboratory tests employed the oedometer test, which applies a vertical load in slow increments under K0 conditions to simulate the behavior of tailings consolidated in the impoundment. The results obtained from the oedometer tests showed interesting observations regarding changes in particle size distribution (PSD) before and after testing. Based on this study it is hard to conclude if the change in PSD solely is caused by crushing. Three samples show a PSD after oedometer which have slightly more fines than before oedometer, while the last sample has neglectable change in PSD. Theoretically, this small change in PSD indicates that larger tailings particles exhibited a higher susceptibility to some degree of crushing, but since the change is so small it cannot be excluded that the changes origins from the accuracy of determining the PSD.  The samples taken at different depths were prepared using the tamping method, and the oedometer testing indicated minimal differences in their compression characteristics, and since the soil fabric was destroyed under sampling and then reconstituted through tamping this is expected. To investigate the influence of particle arrangement on the compression and potential crushing, one of the samples was tested in a slurry configuration. This test demonstrated that particle arrangement appears to be a contributing factor to crushing, as it showed less deviation in particle size distribution compared to the tamped sample. To contextualize and validate the findings, the results were correlated, evaluated, and compared with previous studies conducted on tailings from the same tailings storage facility (TSF). Although future research on crushing in correlation of mineralogy respectively and changes in particle shape are needed, this comparative analysis has provided input that can contribute to enhanced understanding of tailings behavior under increased vertical load.

Ações de restauração ecológica muitas vezes são requeridas como ferramentas para adequação de propriedades rurais às leis vigentes, para a conservação da biodiversidade e manutenção dos serviços ecossistêmicos em áreas públicas e privadas. Deste modo, o desenvolvimento de métodos de baixo custo e que possam ser aplicados em larga escala tem grande relevância ecológica, econômica e social, pois além de aplicados em médias e grandes propriedades, têm especial aptidão para serem usados pelos pequenos proprietários. Neste contexto, o presente estudo tem como objetivo geral: i) avaliar, por meio de dois experimentos, a sobrevivência e o crescimento de indivíduos de espécies arbustivo-arbóreas da Floresta Estacional Semidecidual introduzidas por meio de semeadura direta ou plantio de mudas; e ii) avaliar a possibilidade de se controlar as gramíneas competidoras nas entrelinhas por meio da capina tradicional, da criação de um dossel transitório nas entrelinhas pela semeadura de milho, ou pelo aumento da área das copas via poda da gema apical das espécies de recobrimento. O primeiro experimento constituiu-se da semeadura direta de 36 espécies arbustivo-arbóreas aliada ao plantio de milho na entrelinha como forma de controle de gramíneas invasoras. Resultados mostram que 77,8% das espécies semeadas emergiram, o número de indivíduos encontrado, quando comparado ao número de indivíduos esperados, representou apenas 8% dos mesmos. As espécies com maiores taxas de emergência foram Hymenaea courbaril, Pterogyne nitens, Chrysophyllum gonocarpum, Peltophorum dubium e Mabea fistulifera, representando mais da metade dos indivíduos encontrados. Com relação ao plantio do milho, observou-se que sua presença controlou como desejado as gramíneas invasoras. No segundo experimento, realizou-se o plantio em linhas de mudas de espécies arbóreas aliado a duas estratégias para controle de gramíneas invasoras, criação de um dossel transitório pelo plantio do milho nas entrelinhas, ou a indução do aumento da área das copas de indivíduos das espécies de recobrimento por meio da poda de suas gemas apicais. A sobrevivência dos indivíduos não foi influenciada pela presença do milho e poda das gemas apicais das espécies de recobrimento. O número de bifurcações dos indivíduos podados aumentou. Todavia, a área da copa foi, até os nove meses de observação aqui realizados, menor nos indivíduos podados do que nos não podados. O plantio de milho nas entrelinhas evitou que a área fosse colonizada significativamente por gramíneas invasoras, exercendo um controle sobre essas espécies similar àquele do controle tradicional com capina química. Logo, a utilização do milho para controle de gramíneas é indicada nas ações de restauração, por proporcionar a redução dos custos de restauração, reduz-se os riscos de contaminação química do meio ambiente e do trabalhador rural, e possibilita uma geração de renda proveniente da produção do milho. Além das vantagens ecológicas e econômicas, o milho apresenta uma vantagem social, pois ele torna a prática da restauração mais atrativa para os pequenos produtores, e como consequência há um maior envolvimento dos mesmos nas ações de adequação ambiental de suas propriedades. / Ecological restoration actions are often required as tools for adapting rural properties to existing laws for biodiversity, conservation and maintenance of ecosystem services in public and private areas. Thus, it is necessary to develop techniques that present affordable costs of implantation and maintenance, and that provide a diversification of the income of the owner, through a direct and short term economic return. In this context, the present study aims to evaluate, through two experiments, the survival and growth of individuals of shrub-tree species of the Semideciduous Seasonal Forest introduced through direct sowing or planting of seedlings, and the possibility and differences in controlling invasive grasses between the lines through traditional weed control, the creation of a transitional canopy between the lines by sowing maize, or by increasing the area of the canopies via pruning of the apical bud of some species. The first experiment consisted of the direct seeding of 36 shrub-tree species of the Semidecidual Seasonal Forest allied to the planting of maize in the interline as a form of control of invasive grasses. The results of this experiment show that 77.8% of the seeded species emerged, the number of individuals found when compared to the expected number of individuals, represented only 8% of it. The species that most stood out were Hymenaea courbaril, Pterogyne nitens, Chrysophyllum gonocarpum, Peltophorum dubium and Mabea fistulifera, representing more than half of the individuals that were found. Regarding the planting of maize, it was observed that its presence controlled the invading grasses as desired. In the second experiment, planting was carried out in seedling lines of arboreal species of the Semidecidual Seasonal Forest with two strategies to control invasive grasses: (i) the creation of a transitional canopy by the planting of maize between the lines; (ii) the induction of the individuals crown area increase of the species from the covering group by pruning their apical buds. The survival of all individuals was not influenced by the presence of maize and pruning of the apical buds of the covering group species. There was no difference between the death of pruned and non pruned individuals, and pruning increased the number of bifurcations of individuals. However, the crown area was, up to nine months of observation, smaller in pruned individuals than in non pruned individuals. Maize planting between the lines prevented the area from being colonized significantly by invasive grasses, controlling these species development in a similar way of the traditional control with herbicide application, thus showing an alternative to it. Therefore, its use is indicated in the restoration actions as reductions in restoration costs are possible in controlling the grasses with this method as well as providing a possible generation of income from the maize production. In addition to the ecological and economic advantages, maize has a social advantage, since it makes the restoration practice more attractive for small producers. Consequently there is a greater involvement of the same in the restoration and environmental conservation actions.

Dissertation (Ph.D.)--University of South Florida, 2007. / Includes vita. Includes bibliographical references. Also available online.

The use of coarse-grained fill materials has grown significantly in recent years especially on account of their use in dams and transportation networks. This study investigates compressibility of various coarse-grained fill materials in dry and wet loading conditions in oedometer test. Four materials were used in the experiments, which falls into GP, GW, GM and GC categories respectively. GP material is a weathered rock obtained from Eymir Lake region. This material was chosen especially to be able to investigate degradation and particle breakage due to compaction and compression. GW, GM and GC materials were obtained by using the material called &lsquo / bypass&rsquo / which is a fill material used in the construction of metro of Eryaman. Using these four materials, large-scale double oedometer tests were carried out to investigate compressibility in both dry and wet conditions. The double oedometer testing technique is used to investigate the effect of soaking on compressibility behaviour of compacted fill materials. Various compactive efforts were used in the compaction stage to investigate the effect of compactive effort on compressibility and degradation of the four gravelly materials. Gradations of the post-test samples were obtained and particle breakage due to compaction using various compactive efforts and particle breakage due to compression were determined. It is found that amount of compression does not necessarily depend on the dry density of the material and fine fraction is also a dominating property regarding the compressibility in coarse-grained fill materials. The vertical strains induced by soaking are on the order of 12% - 20% of the compression measured in dry loading case for the well-graded coarse-grained fill materials tested. Besides, there is significant particle breakage in the compaction process and no further particle breakage in the oedometer test for GP material.

Photovoltaic manufacturing is material intensive with the cost of crystalline silicon wafer, used as the substrate, representing 40% to 60% of the solar cell cost. Consequently, there is a growing trend to reduce the silicon wafer thickness leading to new technical challenges related to manufacturing. Specifically, wafer breakage during handling and/or transfer is a significant issue. Therefore improved methods for breakage-free handling are needed to address this problem. An important pre-requisite for realizing such methods is the need for fundamental understanding of the effect of handling device variables on the deformation, stresses, and fracture of crystalline silicon wafers. This knowledge is lacking for wafer handling devices including the Bernoulli gripper, which is an air flow nozzle based device. A computational fluid dynamics model of the air flow generated by a Bernoulli gripper has been developed. This model predicts the air flow, pressure distribution and lifting force generated by the gripper. For thin silicon wafers, the fluid model is combined with a finite element model to analyze the effects of wafer flexibility on the equilibrium pressure distribution, lifting force and handling stresses. The effect of wafer flexibility on the air pressure distribution is found to be increasingly significant at higher air flow rates. The model yields considerable insight into the relative effects of air flow induced vacuum and the direct impingement of air on the wafer on the air pressure distribution, lifting force, and handling stress. The latter effect is found to be especially significant when the wafer deformation is large. In addition to silicon wafers, the model can also be used to determine the lifting force and handling stress produced in other flexible materials. Finally, a systematic approach for the analysis of the total stress state (handling plus residual stresses) produced in crystalline silicon wafers and its impact on wafer breakage during handling is presented. Results confirm the capability of the approach to predict wafer breakage during handling given the crack size, location and fracture toughness. This methodology is general and can be applied to other thin wafer handling devices besides the Bernoulli gripper.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 6 uppsatser.

Dissertation (Ph.D.)--University of South Florida, 2007. / Title from PDF of title page. Document formatted into pages; contains 87 pages. Includes vita. Includes bibliographical references.

Diss. (sammanfattning) Umeå : Umeå universitet, 2010.