Subjects -> ENGINEERING (Total: 2844 journals)
    - CHEMICAL ENGINEERING (247 journals)
    - CIVIL ENGINEERING (248 journals)
    - ELECTRICAL ENGINEERING (176 journals)
    - ENGINEERING (1448 journals)
    - ENGINEERING MECHANICS AND MATERIALS (451 journals)
    - HYDRAULIC ENGINEERING (62 journals)
    - INDUSTRIAL ENGINEERING (97 journals)
    - MECHANICAL ENGINEERING (115 journals)

ENGINEERING (1448 journals)            First | 1 2 3 4 5 6 7 8     

Showing 1201 - 1205 of 1205 Journals sorted alphabetically
Purinergic Signalling     Hybrid Journal   (Followers: 1)
Quaderns d’Història de l’Enginyeria     Open Access  
Quality and Reliability Engineering International     Hybrid Journal   (Followers: 15)
Quality Engineering     Hybrid Journal   (Followers: 12)
Quantum Engineering     Hybrid Journal  
R&D Journal     Open Access   (Followers: 1)
Radiochimica Acta     Hybrid Journal   (Followers: 5)
Rare Metals     Hybrid Journal   (Followers: 3)
Reactive and Functional Polymers     Hybrid Journal   (Followers: 5)
Recent Patents on Engineering     Hybrid Journal   (Followers: 3)
Recent Patents on Nanotechnology     Hybrid Journal   (Followers: 2)
Recherche Transports Sécurité     Hybrid Journal   (Followers: 1)
Redes de Ingeniería     Open Access  
Regional Maritime University Journal     Full-text available via subscription   (Followers: 3)
Regular and Chaotic Dynamics     Hybrid Journal  
Rem : Revista Escola de Minas     Open Access  
Remote Sensing     Open Access   (Followers: 54)
Remote Sensing Letters     Hybrid Journal   (Followers: 46)
Requirements Engineering     Hybrid Journal   (Followers: 3)
Research Ideas and Outcomes     Open Access   (Followers: 1)
Research in Engineering Design     Hybrid Journal   (Followers: 10)
Research Journal of Nanoscience and Nanotechnology     Open Access   (Followers: 18)
Resonance     Hybrid Journal   (Followers: 29)
Respuestas     Open Access  
Results in Engineering     Open Access  
Review of Symbolic Logic     Full-text available via subscription   (Followers: 2)
Reviews in Advanced Sciences and Engineering     Partially Free   (Followers: 1)
Revista AIDIS de Ingeniería y Ciencias Ambientales. Investigación, desarrollo y práctica     Open Access  
Revista Brasileira de Engenharia Agrícola e Ambiental     Open Access   (Followers: 1)
Revista Brasileira de Inovação     Open Access  
Revista Campus     Open Access  
Revista Ciencia y Tecnología     Open Access  
Revista Ciencia y Tecnología     Open Access  
Revista Ciencia y Tecnología El Higo     Open Access   (Followers: 2)
Revista Científica de la UCSA     Open Access  
Revista Colombiana fe Technologias de Avanzada (RCTA)     Open Access   (Followers: 3)
Revista Cubana de Ingeniería     Open Access  
Revista de Ciências Exatas Aplicadas e Tecnológicas da Universidade de Passo Fundo : CIATEC-UPF     Open Access  
Revista de Ciências Exatas e Tecnologia     Open Access   (Followers: 1)
Revista de Ingeniería     Open Access  
Revista de Ingenieria Sismica     Open Access  
Revista de Investigación     Open Access  
Revista de Investigación, Desarrollo e Innovación     Open Access  
Revista de Investigaciones en Energía, Medio Ambiente y Tecnología     Open Access  
Revista de la Universidad del Zulia     Open Access  
Revista EIA     Open Access   (Followers: 1)
Revista Facultad de Ingeniería     Open Access   (Followers: 1)
Revista Facultad de Ingenieria - Universidad de Tarapaca     Open Access   (Followers: 1)
Revista Facultad de Ingeniería Universidad de Antioquia     Open Access   (Followers: 1)
Revista Fatec Zona Sul : REFAS     Open Access  
Revista Iberoamericana de Automática e Informática Industrial RIAI     Open Access  
Revista Informador Técnico     Open Access   (Followers: 1)
Revista Ingenieria de Construcción     Open Access   (Followers: 1)
Revista Interdisciplinar de Pesquisa em Engenharia     Open Access   (Followers: 1)
Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería     Open Access  
Revista Logos Ciencia & Tecnología     Open Access   (Followers: 1)
Revista Técnica de la Facultad de Ingeniería : Universidad del Zulia     Open Access   (Followers: 1)
Revista Tecnología en Marcha     Open Access  
Revista Tecnológica     Open Access   (Followers: 1)
Revista UIS Ingenierías     Open Access  
Revue de Métallurgie     Full-text available via subscription  
RUDN Journal of Engineering Researches     Open Access   (Followers: 1)
Russian Engineering Research     Hybrid Journal  
Russian Journal of Non-Ferrous Metals     Hybrid Journal   (Followers: 21)
Russian Microelectronics     Hybrid Journal   (Followers: 1)
Sadhana     Open Access   (Followers: 10)
Safety Science     Hybrid Journal   (Followers: 28)
Scholedge International Journal of Multidisciplinary & Allied Studies     Open Access   (Followers: 3)
Science & Technique     Open Access   (Followers: 1)
Science and Education : Scientific Publication of BMSTU     Open Access   (Followers: 1)
Science and Engineering Ethics     Hybrid Journal   (Followers: 9)
Science and Technology     Open Access   (Followers: 2)
Science and Technology Indonesia     Open Access   (Followers: 1)
Science China Technological Sciences     Hybrid Journal   (Followers: 1)
Science in Context     Hybrid Journal   (Followers: 4)
Science Journal of Volgograd State University. Technology and innovations     Open Access  
Science Progress     Full-text available via subscription   (Followers: 4)
Sciences & Technologie B : Sciences de l'ingénieur     Open Access  
Scientia cum Industria     Open Access  
Scientific Drilling     Open Access  
Scientific Journal of Control Engineering     Open Access   (Followers: 3)
Scientific Journal of Mehmet Akif Ersoy University     Open Access  
Scientific Journal of Pure and Applied Sciences     Open Access   (Followers: 1)
SCITECH Nepal     Open Access  
Sealing Technology     Full-text available via subscription   (Followers: 1)
Securitas Vialis     Hybrid Journal  
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selcuk University Journal of Engineering, Science and Technology     Open Access   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 57)
Semiconductors     Hybrid Journal   (Followers: 2)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Sensor Letters     Full-text available via subscription   (Followers: 2)
Sensors     Open Access   (Followers: 23)
Separation and Purification Technology     Hybrid Journal   (Followers: 15)
Shock and Vibration     Hybrid Journal   (Followers: 26)
SIAM Journal on Applied Dynamical Systems     Hybrid Journal   (Followers: 2)
SIAM Journal on Mathematical Analysis     Hybrid Journal   (Followers: 4)
SIAM Journal on Matrix Analysis and Applications     Hybrid Journal   (Followers: 3)
SIAM Journal on Numerical Analysis     Hybrid Journal   (Followers: 7)
SIAM Journal on Optimization     Hybrid Journal   (Followers: 11)
SIAM Review     Hybrid Journal   (Followers: 7)
SILICON     Hybrid Journal  
SINERGI     Open Access  
Sistemas & Telemática     Open Access   (Followers: 2)
Sleep and Biological Rhythms     Hybrid Journal   (Followers: 9)
Small     Hybrid Journal   (Followers: 16)
Smart Grid     Open Access   (Followers: 1)
SN Applied Sciences     Hybrid Journal   (Followers: 1)
Sociología y Tecnociencia     Open Access  
Soft Computing     Hybrid Journal   (Followers: 9)
Soil Dynamics and Earthquake Engineering     Hybrid Journal   (Followers: 15)
Solar RRL     Hybrid Journal  
Soldagem & Inspeção     Open Access  
SourceOCDE Developpement urbain, rural et regional     Full-text available via subscription   (Followers: 1)
SourceOCDE Energie     Full-text available via subscription  
SourceOECD Energy     Full-text available via subscription  
SourceOECD Science and Technology Statistics - SourceOCDE Base de donnees des sciences et de la technologie     Full-text available via subscription  
SourceOECD Transport     Full-text available via subscription   (Followers: 2)
SourceOECD Urban, Rural and Regional Development     Full-text available via subscription  
South African Computer Journal     Full-text available via subscription  
South African Journal of Agricultural Extension     Open Access   (Followers: 4)
South African Journal of Science     Open Access   (Followers: 4)
Sports Engineering     Hybrid Journal   (Followers: 2)
Stahlbau     Hybrid Journal   (Followers: 2)
Steel in Translation     Hybrid Journal   (Followers: 1)
Steel Research International     Hybrid Journal   (Followers: 24)
Stochastic Analysis and Applications     Hybrid Journal   (Followers: 2)
Stochastic Processes and their Applications     Hybrid Journal   (Followers: 5)
Stochastics and Dynamics     Hybrid Journal  
Strain     Hybrid Journal   (Followers: 2)
Strategic Planning for Energy and the Environment     Hybrid Journal   (Followers: 4)
Studies in Engineering and Technology     Open Access  
Studies in Interface Science     Full-text available via subscription  
Studies in Logic and Practical Reasoning     Full-text available via subscription  
Studies in Surface Science and Catalysis     Full-text available via subscription   (Followers: 1)
Sud-Sciences et Technologies     Open Access   (Followers: 1)
Superconductor Science and Technology     Hybrid Journal   (Followers: 3)
Surface Engineering     Hybrid Journal   (Followers: 1)
Surface Review and Letters     Hybrid Journal   (Followers: 1)
Surface Science Reports     Full-text available via subscription   (Followers: 20)
Surfaces and Interfaces     Hybrid Journal  
Survey Review     Hybrid Journal   (Followers: 6)
Surveying and Land Information Science     Full-text available via subscription   (Followers: 1)
Surveys in Operations Research and Management Science     Hybrid Journal   (Followers: 3)
Sustainability Science     Open Access   (Followers: 9)
Sustainability Science and Engineering     Full-text available via subscription   (Followers: 3)
Sustainable Management of Sediment Resources     Full-text available via subscription  
Swiss Journal of Geosciences     Hybrid Journal   (Followers: 1)
Symmetry     Open Access   (Followers: 1)
Synthesis Lectures on Algorithms and Software in Engineering     Full-text available via subscription   (Followers: 3)
Synthesis Lectures on Antennas     Full-text available via subscription   (Followers: 5)
Synthesis Lectures on Biomedical Engineering     Full-text available via subscription  
Synthesis Lectures on Computational Electromagnetics     Full-text available via subscription   (Followers: 4)
Synthesis Lectures on Energy and the Environment: Technology, Science, and Society     Full-text available via subscription   (Followers: 1)
Synthesis Lectures on Engineering     Full-text available via subscription  
Synthesis Lectures on Global Engineering     Full-text available via subscription  
Synthesis Lectures on Professionalism and Career Advancement for Scientists and Engineers     Full-text available via subscription   (Followers: 2)
Synthetic Metals     Hybrid Journal   (Followers: 4)
Systems Engineering     Hybrid Journal   (Followers: 7)
Systems Engineering - Theory & Practice     Full-text available via subscription  
Systems Engineering Procedia     Open Access  
Systems Research Forum     Hybrid Journal   (Followers: 1)
Systems Science & Control Engineering     Open Access   (Followers: 8)
Tableros     Open Access   (Followers: 2)
Tapuya : Latin American Science, Technology and Society     Open Access   (Followers: 1)
Technical Tips Online     Full-text available via subscription   (Followers: 1)
Technological Engineering     Open Access   (Followers: 1)
Technologies     Open Access   (Followers: 2)
TECHNOLOGY     Hybrid Journal   (Followers: 1)
Technology and Economics of Smart Grids and Sustainable Energy     Hybrid Journal  
Technology and Innovation     Full-text available via subscription   (Followers: 4)
Technology in Society     Hybrid Journal   (Followers: 7)
Technometrics     Full-text available via subscription   (Followers: 9)
Tecnología y Ciencia     Open Access  
Tecnología y Sociedad     Open Access   (Followers: 1)
TecnoLógicas     Open Access  
Tecnura     Open Access   (Followers: 1)
Tekhné     Open Access   (Followers: 1)
Tekniikan Waiheita     Open Access  
Teknologi dan Kejuruan : Jurnal Teknologi, Kejuruan, dan Pengajarannya     Open Access  
Telecommunications Policy     Hybrid Journal   (Followers: 9)
Textile Science and Technology     Full-text available via subscription   (Followers: 4)
Thalassas : An International Journal of Marine Sciences     Hybrid Journal  
The Engineer     Partially Free  
The Journal of Supercomputing     Hybrid Journal   (Followers: 1)
The Scientific World Journal     Open Access  
Theoretical and Computational Fluid Dynamics     Hybrid Journal   (Followers: 17)
Theoretical Issues in Ergonomics Science     Hybrid Journal   (Followers: 7)
Thermal Engineering     Full-text available via subscription   (Followers: 10)
Tikrit Journal of Engineering Science     Open Access  
tm - Technisches Messen     Hybrid Journal   (Followers: 2)
Topics in Catalysis     Hybrid Journal   (Followers: 1)
Traffic Injury Prevention     Hybrid Journal   (Followers: 75)
Transactions of the Indian National Academy of Engineering     Hybrid Journal   (Followers: 2)
Transactions of the VŠB – Technical University of Ostrava, Safety Engineering Series     Open Access   (Followers: 1)
Transactions of Tianjin University     Full-text available via subscription  
Transport and Aerospace Engineering     Open Access   (Followers: 13)
Transport and Telecommunication     Open Access   (Followers: 4)
Transport World Africa     Full-text available via subscription   (Followers: 2)

  First | 1 2 3 4 5 6 7 8     

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Journal Cover
Rem : Revista Escola de Minas
Journal Prestige (SJR): 0.132
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0370-4467 - ISSN (Online) 1807-0353
Published by SciELO Homepage  [911 journals]
  • Editorial

    •  
  • A stochastic approach for the wind load effect on steel structures

    • Abstract: Abstract The Brazilian design load standard still provides a wind speed map developed in 1977. Since then, new data have been collected and new charts have been proposed in literature. The literature not only alerts to changes in short-term wind gust patterns, but it also warns that the wind speed values are higher than observed in the past. Many researchers have suggested that these differences are correlated to climate change effects. Besides the geophysical and societal impacts of climate change, there is a general concern between designers on the impacts of higher wind speeds on structural design. This paper aims to analyze the wind speed as a stochastic variable and its influence on the design of steel structures when changes in wind speed occur. A stochastic approach is used to evaluate expected stress values for a steel beam-column example. A Monte Carlo analysis is performed on a forty-story steel frame to compare the impact of different wind speed scenarios and types of analysis. In the analyses, the wind speed is approached by a Gumbel distribution and future wind scenarios are generated for sensitiveness evaluation. The analytical and Monte Carlo analyses indicate that greater attention shall be given to the consequences of using an average wind speed value instead of a probability distribution function.
       
  • Surface drainage system for dry docks in shipyards - Case study of
           Estaleiro Rio Grande (Technical Note)

    • Abstract: Abstract This study aims to present a methodology for the design of a surface drainage system for dry docks in shipyards, taking into account the rainfall intensity at the site, the damping capacity of the hydraulic structures (drainage channels) and the pumping capacity of the pumping system. A case study of a dry dock owned by Estaleiro Rio Grande, located at the state of Rio Grande do Sul, is presented. The results obtained indicate alternatives for channel and submersible pump sizing. These pumps would be used to control the dry dock flooding after an intense rainfall event.
       
  • Analisys of hot deformation behavior of super duplex stainless steel UNS
           S32760 through processing maps

    • Abstract: Abstract The need for materials with higher strength and corrosion resistance in corrosive environments, such as in the oil extraction in saline media, has led to the use of super duplex stainless steels in projects such as the Pre-sal. The manufacture of these materials involves the step of thermomechanical processing, whose performance depends on the workability of the material. Processing conditions in which the super duplex stainless steel UNS S32760 can be worked safely and in which the material can fail were investigated in this presentation. The physical simulation was performed by means of hot torsion testing. The tests were performed at temperatures ranging from 900°C to 1200°C and strain rates of 0.01s-1 to 10s-1. The evolution of strain rate sensitivity of flow stress (m) for deformation of 0.5 at all temperatures investigated here was determined. After attaining the values of m for each deformation condition, the values of the power dissipation efficiency (η) were calculated, an instability criterion (ξ) was applied, and processing maps were constructed. Using these maps, the effects of deformation conditions on the power dissipation efficiency and the material plastic instability were discussed. The domains of processing maps, the observed microstructures and the shape of plastic flow stress curves were associated.
       
  • Strategies for corrosion inhibition of slurry pipelines prior to
           commissioning

    • Abstract: Abstract A practice used to prevent corrosion in buried slurry pipelines is the hibernation of pipelines with an aqueous solution containing corrosion inhibitors before beginning the mining operation. The aim of this work is to evaluate the corrosion resistance of API 5L X70 steel used in the slurry pipelines in hibernation solution containing sodium sulphite, sodium hydroxide and glutaraldehyde in a synthetic river water. The electrochemical techniques used are the Tafel analysis and electrochemical impedance spectroscopy. The synergistic effect of the components of hibernation solution on the corrosion resistance of the API 5L X70 steel was evaluated. A lower corrosion resistance was obtained for the API steel in aqueous solution of sodium sulphite, and in solution of sodium sulphite with glutaraldehyde. The hibernation solution was efficient in inhibiting steel corrosion but the highest corrosion inhibition efficiency was obtained with the glutaraldehyde aqueous solution.
       
  • Microstructural analysis in the Fe-30.5Mn-8.0Al-1.2C and
           Fe-30.5Mn-2.1Al-1.2C steels upon cold rolling

    • Abstract: Abstract Electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI) were used to examine microstructural changes of the austenitic low-density Fe-30.5Mn-8.0Al-1.2C (8Al) and Fe-30.5Mn-2.1Al-1.2C (2Al) (wt.%) steels during cold rolling. As the strain increased, deformation mechanisms, such as stacking faults, slip, mechanical twinning, and shear banding were activated in both steels cold rolled up to strain of 0.69. Only slip was noted in these steels at low strain (ε=0.11) and slip dominance was detected in the 8Al steel at higher strains. Shear banding became active at higher strain (ε~0.7) in these materials. An inhomogeneous microstructure formed in both alloys at such strain level. More extensive mechanical twinning in the 2Al alloy than that in the 8Al alloy was observed. Fish bone-like structure patterns were revealed in the 8Al steel and a river-like structure in the 2Al steel. Detailed microstructure features as elongated and fragmented grains along the rolling direction (RD) were found for both steels, as already observed in other high-Mn steels. These deformed structures are composed by lamellar packets which can contain mechanical twins or slip lines and shear bands.
       
  • Damage evolution in a tensile specimen of a ductile stainless steel

    • Abstract: Abstract This paper presents a study about the fracture mechanism of a ferritic stainless steel (UNS S44400 type) during a tensile test. The applied materials for the experimental procedures were 25 specimens of the steel, machined in the rolling direction. Each specimen was submitted to standard polishing procedures. One of the samples, in the original state, was structurally characterized by reflected light optical microscopy. The other samples were submitted to tensile tests with a constant displacement rate. Three samples were tested until failure (complete tests) and the others just until specific strain values, when the tests were interrupted and the samples were characterized by using optical and scanning electron microscopy. The main objective of these characterizations was to evaluate the structural damage evolution and to identify the fracture mechanism for the tested conditions. A methodology to quantify the damage evolution by surface roughness, identified by optical microscopy, was proposed. A new index - Damage by Diffuse Reflection Index (DRI) - was proposed to quantify the damage evolution in function of the specimen deformation. It was possible to confirm the ductile behavior of the studied steel and that the main fracture mechanism was the traditional dimpled rupture.
       
  • Slope stability analysis at highway BR-153 using numerical models

    • Abstract: Abstract An existing cut slope on Highway RS-471/BR-153 is studied. The slope is composed of the Serra Geral Formation's material: a highly altered volcanic breccia and above it a slightly altered and very fractured rhyolite. A numerical analysis of the slope is carried out in two dimensions. Fracturing of the rhyolite necessitates the use of a constitutive model for materials with families of discontinuities (Ubiquitous-joint). To simplify the analysis of the problem and to examine some of the most sensitive variables, two more analyses are made, replacing the initial model by a Mohr's constitutive model, which considers the material as continuous. The results obtained from the Ubiquitous-joint model provide an acceptable representation of the field conditions, showing a failure mechanism type of rockfall from the face of the slope in the rhyolite, and the rupture surface of the breccia, without propagation of surface failure. In the analysis, when considering both materials as continuous, it is not possible to take account the fault conditions simultaneously, and this analysis also requires values of the mechanical parameters different from those recommended in literature.
       
  • Dispersion degree and zeta potential of hematite

    • Abstract: Abstract The dispersion degree of the mineral particles in the pulp is especially relevant regarding the performance of the cationic reverse flotation of iron ores. The gangue minerals should remain dispersed while hematite particles should be selectively flocculated. The present study addressed determinations of dispersion degree and zeta potential of hematite in the presence of different dispersants, classified as organic polymeric (natural and synthetic), organic monomeric, and inorganic. Special attention was paid to results achieved at pH 10, used in plant practice. For natural organic polymers, correlation was observed between the dispersion degree and the increase in the negative value of zeta potential. Some synthetic organic polymers enhance the dispersion of hematite particles despite not affecting significantly the zeta potential. Sodium silicates, irrespectively of the SiO2/Na2O ratio, at pH 10, did not impact significantly either the dispersion degree or the zeta potential.
       
  • Effects of hematite surface characteristicson filtration process

    • Abstract: Abstract In iron ore pelletizing plants a range of process parameters such as particle size distribution, specific surface area, and moisture, must be controlled to achieve optimized operation conditions. Particle size distribution and specific surface area are controlled during the grinding operations. Moisture, however, is controlled during filtration of the ground products. This work investigates the relationship between particle morphology, filter cake moisture and filter capacity. The samples were taken during the filtration tests and referred to three different blends presenting distinct mineralogical features and similar chemical compositions in order to investigate the effects of only the hematite surface characteristics. Six types of morphology are distinguished: granular hematite, tabular hematite, martitic hematite, polycrystalline hematite, hematite-goethite aggregates and goethite. For each filtration test, the filter cloth product was characterised. The characterisation analysis revealed that blends containing martitic hematite concentration above 11.45 percent increased substantially the filter capacity. However, it had also caused an increasing in final moisture content that reached values around 10.0 % compared with industrial moisture specification that can vary on the range of 8.5 to 9.5 %.
       
  • Modelling and Simulation of the Santa Rita Mine Milling Circuit

    • Abstract: Abstract The Santa Rita Mine, located in the State of Bahia, was the first Mirabela Mineração operation in Brazil. Started in 2009, the nickel sulphide processing plant has undergone constant modifications, aiming to adapt to the changes in the ore. Main modifications included autogenous grinding converted to semi-autogenous, as well as the installation of a desliming stage aiming to remove ultrafine minerals which reduced the nickel recovery in flotation. A full survey and ore characterization campaign was carried out to assess alternatives for increasing grinding circuit capacity. Experimental data were balanced and used to calibrate mathematical models which were the basis for simulation exercises. This paper describes the main aspects related to circuit modeling and simulation, as well as assessing alternatives for increasing the grinding circuit capacity.
       
  • Mine/Mill production planning based on a Geometallurgical Model

    • Abstract: Abstract The Pau Branco mine supplies two blast furnaces with iron ore lumps, and currently, charcoal consumption for pig iron production accounts for 47% of the blast furnaces' operational cost. A geometallurgical model is presented to support an economic study considering reserve volumes, product quality, and operational costs based on the metallurgical performance of different iron ore typologies. Sample analysis provides values required in the model. From the model, an alternative production plan is presented with a positive impact of USD 25.6M over the current net present value of the mining/mill system.
       
  • A Geostatistical Framework for Estimating Compositional Data Avoiding Bias
           in Back-transformation

    • Abstract: Abstract Estimation of some mineral deposits involves chemical species or a granulometric mass balance that constitute a closed constant sum (e.g., 100%). Data that add up to a constant are known as compositional data (CODA). Classical geostatistical estimation methods (e.g., kriging) are not satisfactory when CODA are used, since bias is expected when estimated mean block values are back-transformed to the original space. CODA methods use nonlinear transformations, and when the transformed data are interpolated, they cannot be returned directly to the space of the original data. If these averages are back-transformed using the inverse function, bias is generated. To avoid this bias, this article proposes geostatistical simulation of the isometric logratio ratio (ilr) transformations back-transforming point simulated values (instead of block estimations), with the averaging being postponed to the end of the process. The results show that, in addition to maintaining the mass balance and the correlations among the variables, the means (E-types) of the simulations satisfactorily reproduce the statistical characteristics of the grades without any sort of bias. A complete case study of a major bauxite deposit illustrates the methodology.
       
  • Performance analysis of the HRCTM HPGR in pilot plant

    • Abstract: Abstract A pilot scale test program was conducted to evaluate the size reduction performance of HPGR (High Pressure Grinding Rolls) operating in different circuit configurations. For this purpose a series of pilot-HPGR locked cycle tests were performed with medium and high pressures to simulate the HPGR operation in closed circuit with a screen, with partial product recycle, and with edge recycle. Logged instrumentation data such as roller speed, working gap, operating pressure, and power draw were used in combination with material test results such as particle size distributions, flake density, flake thickness, and bulk density of the feed for calculation of HPGR operational parameters. The paper reports the results from the pilot HPGR test work. The analysis reported herein includes an evaluation and comparison of different circuit configurations of the HPGR operation in terms of energy consumption, capacity and product fineness and also discusses the benefits of various circuit arrangements.
       
  • Principal environmental impacts on pipeline tracks as a result of mining
           operations and their mitigated actions

    • Abstract: Abstract This study deals with the main environmental impacts and possible mitigation measures for many pipeline tracks, due to the mining of different substances in areas of interference between mining activities and mineral research and those resulting from construction and gas pipeline operation. By monitoring the identified interferences/disturbances, it was determined that although punctual and small in number, the extraction of mineral resources in the proximity of the gas pipelines could represent risks for the security of the undertaking. In general the risks are consequence either of the use of explosives or of induced erosive processes that could lead to pipeline instability. It is necessary to block the mining activities on both sides of the pipeline tracks in order to minimize risks to the pipeline, to others, to society, and to the environment. Also, the establishment of "flexible" track limits could be adopted in areas adjacent to the pipelines for the exploration of some mineral deposits, thus prioritizing security preservation with a minimum of socio-environmental impacts.
       
 
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