cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7516928
title: Experimental and computer thermodynamics evaluations of an Al-Si-Coating on a quenchable steel

description: Abstract High-strength steels are commonly used in the automobile industry in order to reduce the weight of the vehicles. However, a technical difficulty appears due to the need of hot stamping of the components, which leads to oxidation. Therefore, the application of a coating on the substrate to avoid high-temperature oxidation is used. In this work, experimental analysis and computer thermodynamic calculation were used to describe the phase transformations within an Al-Si coating on a quenchable high strength steel. The Al-Si coating was deposited by hot dipping and its characterization was done using SEM and XRD techniques. Computer thermodynamics calculations were done using the commercial software FactSage using the Calphad methodology. It demonstrated a good relationship between the experimental results and the computer calculations of phase stabilities for the as-deposited condition and after diffusion experiment at 920ºC for 7 minutes, which simulates the thermal cycle of hot stamping of the quenchable steel used.
DOI: 10.6084/m9.figshare.7510022
title: Achieving effective confinement through utilization of non-Newtonian fluid mixture as stemming structure

description: Abstract The economics of a mining operation is directly influenced by blasting outcomes, where blasting aims to comminute the rock mass in order to attain smaller grain sizes to be loaded and hauled at a minimum cost for its first processing stage. In order to promote adequate rock breakage, the stemming structure needs to provide proper confinement for the borehole charged with explosives, reflecting the energy released during the detonation in form of shock waves and gases to act throughout the in situ rock mass, enlarging its failures and fractures, and also creating new ones. To build up a stemming column, literature recommends the usage of dry granular materials instead of elements with plastic behavior. However, a study was performed using Gypsum plaster as stemming; a kind of material that exhibits solid-like behavior when it is dry. Following this theory, this test verified improvements regarding confinement effectiveness and energy propagation throughout the rock mass when a non-Newtonian mixture (NNM) was applied as stemming; a material that shows a solid-like behavior when is under shear stress. When the stemming arrangement was composed of NNM, it was able to reduce energy and gas losses to the atmosphere, because of the liquid's property of filling voids into the borehole. The NNM yielded high results due to its better confinement effectiveness, a reduction of air overpressure, and an increase of the strain propagation and ground vibration throughout the rock.
DOI: 10.6084/m9.figshare.7512278
title: Application challenges for information and automation technologies in an underground mine in Brazil

description: Abstract Organizations can establish a value-added sustainable strategy by increasing asset utilization. WLAN infrastructure in underground mines tends to be a consistent platform for reliability in data/information management, and assertive governance practices. It enables remote monitoring, registering and data transfer from a control room, avoiding unnecessary human exposure in risk zones while adding agility to operation and maintenance related processes. A series of challenges must be considered so that onboard electronic systems combined with information technology infrastructure can become part of the operational strategy. Leaders must effectively manage to adapt organizations to new standards. This study aims to discuss the challenges related to implement information and automation technologies in an underground mine in Brazil. Data collected in a base metals underground mine is the basis for utilization, reliability and productivity analysis of computerized drilling equipment operating under severe conditions. The study concludes that searching for state-of-the-art operational practices demands a cultural change in organizations, followed by a redefinition of peoples' roles and processes, so technology can provide full integration and be used as a management platform for decision-making.
DOI: 10.6084/m9.figshare.7512278.v1
title: Application challenges for information and automation technologies in an underground mine in Brazil

description: Abstract Organizations can establish a value-added sustainable strategy by increasing asset utilization. WLAN infrastructure in underground mines tends to be a consistent platform for reliability in data/information management, and assertive governance practices. It enables remote monitoring, registering and data transfer from a control room, avoiding unnecessary human exposure in risk zones while adding agility to operation and maintenance related processes. A series of challenges must be considered so that onboard electronic systems combined with information technology infrastructure can become part of the operational strategy. Leaders must effectively manage to adapt organizations to new standards. This study aims to discuss the challenges related to implement information and automation technologies in an underground mine in Brazil. Data collected in a base metals underground mine is the basis for utilization, reliability and productivity analysis of computerized drilling equipment operating under severe conditions. The study concludes that searching for state-of-the-art operational practices demands a cultural change in organizations, followed by a redefinition of peoples' roles and processes, so technology can provide full integration and be used as a management platform for decision-making.
DOI: 10.6084/m9.figshare.7514255.v1
title: Optimizing short-term production plan using a portfolio optimization model

description: Abstract Short-term production plans are the basis for operational mine production schedules. They concentrate on making long-term mine plans operationally feasible. It ensures a steady flow of product for meeting blending targets. Due to the quality variation of material, blend optimization is an uncertainty based optimization problem. There are different approaches toward uncertainty management and the current paper investigates a portfolio optimization model in order to minimize the risks in short-term plans. In this paper, a fuzzy linear programming model is formulated to provide a set of options for the mine plan. These blending options are treated as portfolios. Then a model for the optimal selection of a portfolio is introduced. The objective of the model is to maximize the expected return of the portfolio under constraints limiting its variance. The model is applied in a limestone mine complex.
DOI: 10.6084/m9.figshare.7510022.v1
title: Achieving effective confinement through utilization of non-Newtonian fluid mixture as stemming structure

description: Abstract The economics of a mining operation is directly influenced by blasting outcomes, where blasting aims to comminute the rock mass in order to attain smaller grain sizes to be loaded and hauled at a minimum cost for its first processing stage. In order to promote adequate rock breakage, the stemming structure needs to provide proper confinement for the borehole charged with explosives, reflecting the energy released during the detonation in form of shock waves and gases to act throughout the in situ rock mass, enlarging its failures and fractures, and also creating new ones. To build up a stemming column, literature recommends the usage of dry granular materials instead of elements with plastic behavior. However, a study was performed using Gypsum plaster as stemming; a kind of material that exhibits solid-like behavior when it is dry. Following this theory, this test verified improvements regarding confinement effectiveness and energy propagation throughout the rock mass when a non-Newtonian mixture (NNM) was applied as stemming; a material that shows a solid-like behavior when is under shear stress. When the stemming arrangement was composed of NNM, it was able to reduce energy and gas losses to the atmosphere, because of the liquid's property of filling voids into the borehole. The NNM yielded high results due to its better confinement effectiveness, a reduction of air overpressure, and an increase of the strain propagation and ground vibration throughout the rock.
DOI: 10.6084/m9.figshare.7514255
title: Optimizing short-term production plan using a portfolio optimization model

description: Abstract Short-term production plans are the basis for operational mine production schedules. They concentrate on making long-term mine plans operationally feasible. It ensures a steady flow of product for meeting blending targets. Due to the quality variation of material, blend optimization is an uncertainty based optimization problem. There are different approaches toward uncertainty management and the current paper investigates a portfolio optimization model in order to minimize the risks in short-term plans. In this paper, a fuzzy linear programming model is formulated to provide a set of options for the mine plan. These blending options are treated as portfolios. Then a model for the optimal selection of a portfolio is introduced. The objective of the model is to maximize the expected return of the portfolio under constraints limiting its variance. The model is applied in a limestone mine complex.
DOI: 10.6084/m9.figshare.7506590
title: Use of an Artificial Neural Network in determination of iron ore pellet bed permeability

description: Abstract The thermal processing of iron ore pellets in pelletizing plants is a decisive stage regarding final product quality and knowledge of its characteristics has a fundamental importance in its process optimization. This study evaluated the variable sensitivity involved in pellet bed formations and their permeability using the artificial neural networks method. The model stated that standard diameter deviation, sphericity and pellet bed height mostly affect bed permeability. The computational model was able to predict pellet bed backpressure by means of pellet geometrical features, thus allowing improving green pellet generation, in order to ensure fuel and energy consumption reduction, final quality improvement and better productivity.
DOI: 10.6084/m9.figshare.7506590.v1
title: Use of an Artificial Neural Network in determination of iron ore pellet bed permeability

description: Abstract The thermal processing of iron ore pellets in pelletizing plants is a decisive stage regarding final product quality and knowledge of its characteristics has a fundamental importance in its process optimization. This study evaluated the variable sensitivity involved in pellet bed formations and their permeability using the artificial neural networks method. The model stated that standard diameter deviation, sphericity and pellet bed height mostly affect bed permeability. The computational model was able to predict pellet bed backpressure by means of pellet geometrical features, thus allowing improving green pellet generation, in order to ensure fuel and energy consumption reduction, final quality improvement and better productivity.
DOI: 10.6084/m9.figshare.7506593.v1
title: Evaluation of hydrogen-Induced cracking resistance of the In625 laser coating system on a C-Mn steel substrate

description: Abstract The corrosion of C-Mn steels in the presence of hydrogen sulfide (H2S) represents a significant challenge to oil production and natural gas treatment facilities. The failure mechanism induced by hydrogen-induced cracking (HIC) in a Inconel 625 coating / C-Mn steel has not been extensively investigated in the past. In the present work, an API 5CT steel was coated with In625 alloy using laser cladding and the HIC resistance of different regions, such as the coating surface, the substrate and HAZ, were evaluated. SEM observations illustrated that all HIC cracks were formed at the hard HAZ after 96h of exposure. No HIC cracks were observed in the substrate and the In625 coating after the same exposure duration. Pitting was recorded in the substrate caused by non-metallic inclusion dissolving.
DOI: 10.6084/m9.figshare.7506593
title: Evaluation of hydrogen-Induced cracking resistance of the In625 laser coating system on a C-Mn steel substrate

description: Abstract The corrosion of C-Mn steels in the presence of hydrogen sulfide (H2S) represents a significant challenge to oil production and natural gas treatment facilities. The failure mechanism induced by hydrogen-induced cracking (HIC) in a Inconel 625 coating / C-Mn steel has not been extensively investigated in the past. In the present work, an API 5CT steel was coated with In625 alloy using laser cladding and the HIC resistance of different regions, such as the coating surface, the substrate and HAZ, were evaluated. SEM observations illustrated that all HIC cracks were formed at the hard HAZ after 96h of exposure. No HIC cracks were observed in the substrate and the In625 coating after the same exposure duration. Pitting was recorded in the substrate caused by non-metallic inclusion dissolving.
DOI: 10.6084/m9.figshare.7512944.v1
title: Influence of SEBS-MA and SBS compatibilizers on properties and morphology of blends of polystyrene/rubber residue (SBRr) from the footwear industry

description: Abstract The reuse of rubber waste is very important today, both to reduce the harmful effects on the environment, and to reduce the cost of new material development. Considering that most of the studies reported in literature refer to the reuse of tire waste, this article aims to evaluate the influence of styrene-butadiene-styrene (SBS) and styrene-(ethylene-butylene)-styrene grafted with maleic anhydride (SEBS-MA) compatibilizers on the blend performance of polystyrene (PS)/styrene-butadiene rubber residue (SBRr), which come from the footwear industry. The blends were prepared in a co-rotating twin screw extruder and then were molded by injection. They were analyzed by impact and tensile tests, heat deflection temperature (HDT), ductile-brittle transition temperature, dynamic mechanical thermal analysis (DMTA) and transmission electron microscopy (TEM). The results evidenced that the use of any of the compatibilizers on the PS/SBRr blend significantly increased the impact strength, while the tensile properties and HDT were lower when compared to the polymer matrix. The ductile-brittle transition temperature remains at approximately 25°C range for all the blends. In general, it has been proved that the SBS was the most effective compatibilization process in the PS/SBRr system. The DMTA test shows the presence of two distinct temperature peaks. The morphologies obtained by TEM of binary and ternary blends were quite different and typical of immiscible blend. The results show a good perspective regarding the use of industrial waste (SBRr), since it may enhance a material that would be discarded.
DOI: 10.6084/m9.figshare.7512944
title: Influence of SEBS-MA and SBS compatibilizers on properties and morphology of blends of polystyrene/rubber residue (SBRr) from the footwear industry

description: Abstract The reuse of rubber waste is very important today, both to reduce the harmful effects on the environment, and to reduce the cost of new material development. Considering that most of the studies reported in literature refer to the reuse of tire waste, this article aims to evaluate the influence of styrene-butadiene-styrene (SBS) and styrene-(ethylene-butylene)-styrene grafted with maleic anhydride (SEBS-MA) compatibilizers on the blend performance of polystyrene (PS)/styrene-butadiene rubber residue (SBRr), which come from the footwear industry. The blends were prepared in a co-rotating twin screw extruder and then were molded by injection. They were analyzed by impact and tensile tests, heat deflection temperature (HDT), ductile-brittle transition temperature, dynamic mechanical thermal analysis (DMTA) and transmission electron microscopy (TEM). The results evidenced that the use of any of the compatibilizers on the PS/SBRr blend significantly increased the impact strength, while the tensile properties and HDT were lower when compared to the polymer matrix. The ductile-brittle transition temperature remains at approximately 25°C range for all the blends. In general, it has been proved that the SBS was the most effective compatibilization process in the PS/SBRr system. The DMTA test shows the presence of two distinct temperature peaks. The morphologies obtained by TEM of binary and ternary blends were quite different and typical of immiscible blend. The results show a good perspective regarding the use of industrial waste (SBRr), since it may enhance a material that would be discarded.
DOI: 10.6084/m9.figshare.7507742
title: Optimization of location and forces of friction dampers

description: Abstract Damper optimization is a new area which has been investigated in recent years. There are various methods employed in optimization, among which are highlighted the classic and the most recent that are functioning with reliability, efficiency and speed for optimum results. This paper proposes a method for simultaneous optimization of placement and forces of friction dampers using the Firefly Algorithm, which is a recent meta-heuristic algorithm inspired in the behavior of fireflies. Herein, three different optimization objective are presented: i) minimize the maximum displacement at the top of the structure; ii) minimize the maximum inter-story drift; iii) minimize the maximum acceleration at the top of the structure. The three objective functions were evaluated in two civil structures (a nine-story building and a sixteen-story building) subjected to two real seismic records. The first seismic record is El Centro, which took place in the southeastern California on the boarder of the United States and Mexico in 1940. The second one is the earthquake that occurred in Caucete, province of San Juan, Argentina, in 1977. The results showed that the proposed method was able to optimize the friction dampers, reducing considerably the response of the structures.
DOI: 10.6084/m9.figshare.7507742.v1
title: Optimization of location and forces of friction dampers

description: Abstract Damper optimization is a new area which has been investigated in recent years. There are various methods employed in optimization, among which are highlighted the classic and the most recent that are functioning with reliability, efficiency and speed for optimum results. This paper proposes a method for simultaneous optimization of placement and forces of friction dampers using the Firefly Algorithm, which is a recent meta-heuristic algorithm inspired in the behavior of fireflies. Herein, three different optimization objective are presented: i) minimize the maximum displacement at the top of the structure; ii) minimize the maximum inter-story drift; iii) minimize the maximum acceleration at the top of the structure. The three objective functions were evaluated in two civil structures (a nine-story building and a sixteen-story building) subjected to two real seismic records. The first seismic record is El Centro, which took place in the southeastern California on the boarder of the United States and Mexico in 1940. The second one is the earthquake that occurred in Caucete, province of San Juan, Argentina, in 1977. The results showed that the proposed method was able to optimize the friction dampers, reducing considerably the response of the structures.
DOI: 10.6084/m9.figshare.7518620
title: The role of underground construction for the mobility, quality of life and economic and social sustainability of urban regions

description: Abstract Tunnelling has been used for several purposes for thousands of years. In the coming years the world's population will increase in the urban areas. So, the urban centres will have to adapt, in order to guarantee that their future population will have the necessary and sustainable growth. Due to the constraints for surface construction, also connected to environmental issues, this population growth will imply a greater use of the underground. With this optimal growth, the population of the cities will have better mobility, quality of life, and economic and social sustainability. In a first phase, this report will present a historic approach to tunnelling and its foreseeable future. Afterwards, we will present some considerations on the three factors which tunnelling impacts: mobility, quality of life and social sustainability. As a case study, we will analyse the 2nd phase of the construction of the Marão Tunnel (TDM) - the longest ever built in the Iberian Peninsula- and describe the options made regarding each of those factors. In this case study, the options implemented made it possible to successfully execute the works. For the industry, this work is important because it describes a successful management of the aspects under analysis.
DOI: 10.6084/m9.figshare.7518620.v1
title: The role of underground construction for the mobility, quality of life and economic and social sustainability of urban regions

description: Abstract Tunnelling has been used for several purposes for thousands of years. In the coming years the world's population will increase in the urban areas. So, the urban centres will have to adapt, in order to guarantee that their future population will have the necessary and sustainable growth. Due to the constraints for surface construction, also connected to environmental issues, this population growth will imply a greater use of the underground. With this optimal growth, the population of the cities will have better mobility, quality of life, and economic and social sustainability. In a first phase, this report will present a historic approach to tunnelling and its foreseeable future. Afterwards, we will present some considerations on the three factors which tunnelling impacts: mobility, quality of life and social sustainability. As a case study, we will analyse the 2nd phase of the construction of the Marão Tunnel (TDM) - the longest ever built in the Iberian Peninsula- and describe the options made regarding each of those factors. In this case study, the options implemented made it possible to successfully execute the works. For the industry, this work is important because it describes a successful management of the aspects under analysis.
DOI: 10.6084/m9.figshare.7515290.v1
title: FTIR study of aquamarines after gamma irradiation, heat treatment and electrodiffusion

description: Abstract Beryl, Be3Al2(SiO3)6, is a natural gemstone with many colors. Some of these colors can be induced or modified by exposure to ionizing radiation, by heating, and maybe by electrodiffusion. Small contents of chromophore chemical elements are related to the colors of beryl, like iron, chromium, vanadium, manganese, and others. There is great interest in relation to methods of improving or inducing colors in beryl. There is evidence that infrared spectroscopy (FTIR) can contribute to foresee beryl behavior submitted to procedures for color change. It was observed that electrodiffusion with or without contaminant ions did not alter the FTIR spectrum of aquamarines, unlike heat treatment. Green samples have a higher content of type I water molecules, whereas blue samples have a higher content of type II water molecules. Significant changes in FTIR spectra of aquamarines were observed only in green samples after exposure to gamma rays or to heat. The vanishing of the band at 3633 cm-1 may be related to the position of Na+ ion in the crystal lattice of beryl.