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Modification of fly ash produced in the process of burning fossil fuels - granulation method

IOP Conference Series: Earth and Environmental science 2019年第1期214卷

作者： P Gara E Wisła-Walsh AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics al. Mickiewicza 30 30-059 Cracow Poland

The low grain size of fly ashes from the combustion of fossil fuels creates a number of ecological problems both during storage and transport, and often makes their re-use more difficult. One way to avoid this problem is to compact these materials in the granulation process. The granulation process generally requires the use of different binders, which are divided into matrix, film, and chemical type binders. Depending on the chemical composition of the fly ash and the type of the binder used, the obtained aggregate forms (granulates) find numerous applications, e.g. in the production of adhesives, zeolites and/or concrete, in manufacture of building materials, and in aggregates for road works or for ground leveling. In many applications, especially in road engineering works or in ground leveling, the basic requirements, next to the compressive strength of the granules obtained, are the leachability of sulfate ions and the pH-value of the eluates. The paper presents a research study investigating the granulation process of fly ashes produced by the combustion of hard and brown coals burned in both pulverized and fluidized furnaces, with the application of the following binders: water, calcium sulfate hemihydrate, and mixture of calcium sulfate hemihydrate and calcium hydroxide. For the resulting granulates, tests were conducted to determine compressive strength, SO2 sorption capacity, the pH-value, and the content of sulfate ions in the eluate before and after sorption tests. The obtained results show that the granulation process mostly decreases leachability of sulfate ions and the pH-value of the eluates while simultaneously providing adequate compressive strength of the obtained compacted forms (granulates).

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Method of determining the bond work index in vibratory crushing 17

Method of determining the bond work index in vibratory crush...

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17th International Multidisciplinary Scientific Geoconference, SGEM 2017

作者： Mazur, Marcin AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Department of Mining Dressing and Transport Machines Poland

ISBN: (纸本)9786197408263

The paper presents a new method of determining the energy consumption for vibratory crushing. Using the laboratory vibratory jaw crusher with kinematic actuation of the jaws, the study of determining power consumption while crushing limestone and diabase was conducted. During the study, electrical energy used on the crushing process was measured as a function of changing design and kinematic parameters of the vibratory crusher, i.e.: jaws stroke, the outlet gap size and frequency of jaws vibration. The article presents program of the research, the laboratory test stand of the vibratory jaw crusher KW 40/1 and the test results. Comparing the theoretical crushing energy requirements, determined by the Bond hypothesis, with the values measured during tests a large differences were observed. Using the Bond hypothesis the Vibratory Work Indexes were determined for the tested materials. Their values are higher than limestone and diabase Work Indexes available in the known literatures. The explanation may be greater amount of energy transferred to the material during vibratory crushing, which results in much higher efficiency of the crushing process. © SGEM2017. All Rights Reserved.

关键词： Crushers

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Simulation tests of new solution of the longwall shearer haulage system

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IOP Conference Series: Materials science and Engineering 2019年第1期679卷

作者： K Kotwica G Stopka P Gospodarczyk AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Al. Mickiewicza 30 30-059 Cracow Poland

The article presents the idea of a new solution for KOMTRACK longwall shearer haulage system. Based on the analysis of test results of an earlier version of the FLEXTRACK haulage system, a new version of the KOMTRACK system was developed. Using the ANSYS LS-Dyna program, simulations of the longwall shearer's drive wheel mating with the selected elements of the toothed haulage segment were performed. The purpose of the analyzes was identification of contact stress value of the elements of the feed system as a function of geometrical parameters of various solutions of the toothed bar. The result of the simulation was the selection of the rack solution for further field and industrial tests.

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Constitutive equation to predict the flow stress and the processing maps of the Ni55Cr45 alloy

Constitutive equation to predict the flow stress and the pro...

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26th International Conference on Metallurgy and Materials, METAL 2017

作者： Lukaszek-Solek, Aneta Chyla, Piotr Światoniowski, Andrzej Szostak, Janusz AGH University of Science and Technology Faculty of Metals Engineering and Industrial Computer Science Cracow Poland AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Cracow Poland

ISBN: (纸本)9788087294796

The hot deformation behaviour of Ni55Cr45 alloy was investigated by isothermal compression test on the GLEEBLE 3800 thermo-mechanical simulator in the wide range of temperatures (750-1150 °C) and strain rates (1-100 s-1). The experimental stress-strain data were employed to develop the constitutive equation and activation energy of the investigated Ni-Cr alloy. The correlation between the flow stress, temperature and strain rate at high temperatures was expressed by an Arrhenius type equation. The effects of temperature and strain rate on deformation behaviour were represented by Zener-Hollomon parameter in an exponent-type equation. Activation energy was calculated using a sine-hyperbolic type equation. The processing maps based on the Murty's approach were developed. The processing window and the flow instability areas were determined. Furthermore the experimental rolling test was conducted according to delineated processing parameters. The results of numerical simulation and experimental rolling test showed good agreement with the optimum hot deformation condition. © 2017 TANGER Ltd., Ostrava.

关键词： Activation energy

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Fractal geometry as a tool for description of morphology and behaviour of particles in suspensions 17

Fractal geometry as a tool for description of morphology and...

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17th International Multidisciplinary Scientific Geoconference, SGEM 2017

作者： Banas, Marian Hilger, Bartlomiej AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Department of Power Systems and Environmental Protection Krakow Poland

ISBN: (纸本)9786197408263

In recent years there was a development in fractal geometry. Existing possibilities are enormous-fractal geometry was used with success in many scientific fields. One of these fields was to use fractal geometry as a tool in order to describe morphology characteristics of solid phase contained in various suspensions of miscellaneous origins. There are multiple different sources from which solid phase of suspensions can originate. Solid phase can be derived from industry (e.g. steel industry, metallurgy or mineral processing), or municipal processes (e.g. water treatment). A lot of the suspensions in industrial processes tend to be grainy in their nature, and the process of solid phase separation from that kind of suspensions is relatively well described. On the other hand, many suspensions, and especially their solid phase coming from municipal processes are not spherical which is foundation of many models which describe the grainy suspensions. Fractal geometry can help to better understand the morphology of solid phase, especially in the case of non grainy suspensions. Also behaviour of the particles-the fall of the particles in suspension (velocity of solid phase particles) can be better described with the use of fractal geometry. The aim of this work is to present a way in which morphology of the suspension could be described as fractal. © SGEM2017.

关键词： Morphology

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Pre and post-hoc diagnosis and interpretation of malignancy from breast DCE-MRI

arXiv

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arXiv 2018年

作者： Maicas, Gabriel Bradley, Andrew P. Nascimento, Jacinto C. Reid, Ian Carneiro, Gustavo Australian Institute for Machine Learning University of Adelaide Australia Science and Engineering Faculty Queensland University of Technology Australia Institute for Systems and Robotics Instituto Superior Tecnico Portugal

We propose a new method for breast cancer screening from DCE-MRI based on a post-hoc approach that is trained using weakly annotated data (i.e., labels are available only at the image level without any lesion delineation). Our proposed post-hoc method automatically diagnosis the whole volume and, for positive cases, it localizes the malignant lesions that led to such diagnosis. Conversely, traditional approaches follow a pre-hoc approach that initially localises suspicious areas that are subsequently classified to establish the breast malignancy - this approach is trained using strongly annotated data (i.e., it needs a delineation and classification of all lesions in an image). Another goal of this paper is to establish the advantages and disadvantages of both approaches when applied to breast screening from DCE-MRI. Relying on experiments on a breast DCE-MRI dataset that contains scans of 117 patients, our results show that the post-hoc method is more accurate for diagnosing the whole volume per patient, achieving an AUC of 0.91, while the pre-hoc method achieves an AUC of 0.81. However, the performance for localising the malignant lesions remains challenging for the post-hoc method due to the weakly labelled dataset employed during training. Copyright © 2018, The Authors. All rights reserved.

关键词： Magnetic resonance imaging

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Metrics Reloaded: Recommendations for image analysis validation

arXiv

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arXiv 2022年

作者： Maier-Hein, Lena Reinke, Annika Godau, Patrick Tizabi, Minu D. Buettner, Florian Christodoulou, Evangelia Glocker, Ben Isensee, Fabian Kleesiek, Jens Kozubek, Michal Reyes, Mauricio Riegler, Michael A. Wiesenfarth, Manuel Emre Kavur, A. Sudre, Carole H. Baumgartner, Michael Eisenmann, Matthias Heckmann-Nötzel, Doreen Rädsch, Tim Acion, Laura Antonelli, Michela Arbel, Tal Bakas, Spyridon Benis, Arriel Blaschko, Matthew B. Jorge Cardoso, M. Cheplygina, Veronika Cimini, Beth A. Collins, Gary S. Farahani, Keyvan Ferrer, Luciana Galdran, Adrian Ginneken, Bram Van Haase, Robert Hashimoto, Daniel A. Hoffman, Michael M. Huisman, Merel Jannin, Pierre Kahn, Charles E. Kainmueller, Dagmar Kainz, Bernhard Karargyris, Alexandros Karthikesalingam, Alan Kenngott, Hannes Kofler, Florian Kopp-Schneider, Annette Kreshuk, Anna Kurc, Tahsin Landman, Bennett A. Litjens, Geert Madani, Amin Maier-Hein, Klaus Martel, Anne L. Mattson, Peter Meijering, Erik Menze, Bjoern Moons, Karel G.M. Müller, Henning Nichyporuk, Brennan Nickel, Felix Petersen, Jens Rajpoot, Nasir Rieke, Nicola Saez-Rodriguez, Julio Sánchez, Clara I. Shetty, Shravya Smeden, Maarten Van Summers, Ronald M. Taha, Abdel A. Tiulpin, Aleksei Tsaftaris, Sotirios A. Calster, Ben Van Varoquaux, Gaël Jäger, Paul F. Heidelberg Division of Intelligent Medical Systems and HI Helmholtz Imaging Germany Faculty of Mathematics and Computer Science and Medical Faculty Heidelberg University Heidelberg Germany NCT Heidelberg a partnership between DKFZ University Medical Center Heidelberg Germany Faculty of Mathematics and Computer Science Heidelberg University Heidelberg Germany Heidelberg Division of Intelligent Medical Systems Germany partner site Frankfurt/Mainz a partnership between DKFZ and UCT Frankfurt-Marburg Germany Heidelberg Goethe University Frankfurt Germany Department of Medicine Goethe University Frankfurt Germany Department of Informatics Frankfurt Cancer Insititute Germany Department of Computing Imperial College London London United Kingdom Heidelberg Division of Medical Image Computing and HI Applied Computer Vision Lab Germany Institute for AI in Medicine University Medicine Essen Essen Germany Centre for Biomedical Image Analysis Faculty of Informatics Masaryk University Brno Czech Republic ARTORG Center for Biomedical Engineering Research University of Bern Bern Switzerland Department of Radiation Oncology University Hospital Bern University of Bern Bern Switzerland Simula Metropolitan Center for Digital Engineering Oslo Norway UiT The Arctic University of Norway Romsø Norway Heidelberg Division of Biostatistics Germany Heidelberg Division of Intelligent Medical Systems Division of Medical Image Computing HI Applied Computer Vision Lab Germany MRC Unit for Lifelong Health and Ageing UCL Centre for Medical Image Computing Department of Computer Science University College London London United Kingdom School of Biomedical Engineering and Imaging Science King’s College London London United Kingdom Heidelberg Division of Medical Image Computing Germany Instituto de Cálculo CONICET – Universidad de Buenos Aires Buenos Aires Argentina Centre for Medical Image Computing University College London London United Kingdom McGill University Montréal

Increasing evidence shows that flaws in machine learning (ML) algorithm validation are an underestimated global problem. Particularly in automatic biomedical image analysis, chosen performance metrics often do not reflect the domain interest, thus failing to adequately measure scientific progress and hindering translation of ML techniques into practice. To overcome this, we created Metrics Reloaded, a comprehensive framework guiding researchers in the problem-aware selection of metrics. It was developed by a large international consortium in a multi-stage Delphi process and is based on the novel concept of a problem fingerprint – a structured representation of the given problem that captures all aspects that are relevant for metric selection, from the domain interest to the properties of the target structure(s), data set and algorithm output. Based on the problem fingerprint, users are guided through the process of choosing and applying appropriate validation metrics while being made aware of potential pitfalls. Metrics Reloaded targets image analysis problems that can be interpreted as a classification task at image, object or pixel level, namely image-level classification, object detection, semantic segmentation, and instance segmentation tasks. To improve the user experience, we implemented the framework in the Metrics Reloaded online tool. Following the convergence of ML methodology across application domains, Metrics Reloaded fosters the convergence of validation methodology. Its applicability is demonstrated for various biomedical use cases. © 2022, CC BY.

关键词： Semantic Segmentation

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Friction and wear resistance of Al2O3 40TiO2 (AMDRY 6250) coating of a pump shaft sleeve bearing

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IOP Conference Series: Materials science and Engineering 2020年第1期724卷

作者： V Paleu C Cîrlan Paleu B Istrate S Bhaumik C Munteanu Gheorghe Asachi Technical University of Iaşi Mechanical Engineering Faculty Mechanical Engineering Mechatronics and Robotics Department 63 D. Mangeron Blvd. 700050 Iaşi RO Tribology and Surface Interaction Research Laboratory Department of Mechanical Engineering SRM Institute of Science and Technology Kattankulathur IN

The equipment of wastewater treatment plants is continuously subjected to different kinds of wear, as corrosion, abrasion, cavitation, erosion etc. The most affected components are those of slurry pumps, the slurry producing intense abrasive wear. The service life of pumps (wear rings, sealing, bearings, impellers, and casings) can considerably be extended by proper coating. Before the implementation of a new coating in equipment, its friction and wear behaviour must be determined beside corrosion resistance. This paper presents the results of friction tests carried out on AMSLER machine. The tribological pair was composed by Al2O3 40TiO2 (AMDRY 6250) coating deposited on substrate of a pump shaft sleeve running against a rolling bearing steel disk in dry lubrication conditions. The experimental results are compared against those obtained for uncoated steel.

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Critical coagulation concentration for bentonite suspension 17

Critical coagulation concentration for bentonite suspension

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17th International Multidisciplinary Scientific Geoconference, SGEM 2017

作者： Warzecha, Piotr Hilger, Bartlomiej AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Department of Power Systems and Environmental Protection Kraków Poland

ISBN: (纸本)9786197408263

The main purpose of the research presented in this paper is to study of volume coagulation of bentonite suspension. The study included measurement of particle size distribution, chemical and phase analysis of prepared suspension, as well as preparation of graph and determination of dependence between concentration of the suspension and the turbidity. Relationship between coagulant dose and concentration was also determined. Also research on usage of a several different mixtures of two distinct coagulants to intensify the process of coagulation was conducted. The results could be used by water treatment stations in order to use the mixtures instead of pure coagulant and the efficiency of these mixtures could be equally good if not better than in the case of using single, pure coagulant. The research can also help in determination of critical coagulation concentration during research of coagulation process or designing high – performance sedimentation equipment for suspension of similar origin in water treatment process. © SGEM2017.

关键词： Turbidity

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Effect of microstructure on wear behaviour of aluminium 2014 (Al2014)

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IOP Conference Series: Materials science and Engineering 2020年第1期724卷

作者： S Bhaumik V Paleu D Chowdhury C Cîrlan Paleu S Datta Tribology and Surface Interaction Research Laboratory Department of Mechanical Engineering SRM Institute of Science and Technology Kattankulathur IN Gheorghe Asachi Technical University of Iaşi Mechanical Engineering Faculty Mechanical Engineering Mechatronics and Robotics Department 63 D. Mangeron Blvd. 700050 Iaşi RO

The paper investigates the effect of ageing on the hardness and wearing of Al2014. Precipitation hardening and ageing were carried out on the samples. The samples were solution treated at 550°C and were naturally aged. Quenching was carried out using ice-brine solution. Vickers Hardness were taken at regular intervals till 900 hours. The peak hardness value of the natural aged sample was found to be 86HV (93 hours) as compared to the untreated sample (32.4HV) The wear tests were conducted at 10N, 500rpm for 30 minutes. After the tribo test it was observed that the coefficient of friction increased by 7.06% in the naturally aged sample, but the wear rate in case of as-received samples was 46% higher than that of the naturally aged sample. The change in the microstructure of Al2014 is the primary reason for the difference in wear rate of the samples. The present work will help to understand the influence of heat treatment of aluminium alloy on wear properties.

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