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Performance of evolutionary optimized machine learning for modeling total organic carbon in core samples of shale gas fields

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Petroleum 2024年第1期10卷 150-164页

作者： Leonardo Goliatt c.M.Saporetti L.c.Oliveira E.pereira Department of computational and Applied Mechanics Federal University of Juiz de ForaJuiz de ForaBrazil Department of computational Modeling Polytechnic InstituteRio de Janeiro State UniversityNova FriburgoBrazil Petrobras Rio de JaneiroBrazil Department of Stratigraphy and Paleontology Rio de Janeiro State UniversityRio de JaneiroBrazil

Rock samples'TOc content is the best indicator of the organic matter in source *** origin rock samples’analysis is used to calculate it manually by *** method requires time and resources because it relies on samples from many well intervals in source ***,research has been done to aid this *** learning algorithms can estimate total organic carbon instead of well logs and stratigraphic *** light of these efforts,the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and *** algorithms,differential evolution,particle swarm optimization,grey wolf optimization,artificial bee colony,and evolution strategies were used to improve machine learning models to predict *** six metaheuristics were integrated into four machine learning methods:extreme learning machine,elastic net linear model,linear support vector regression,and multivariate adaptive regression *** samples from the YuDong-Nan shale gas field,located in the Sichuan basin,were used to evaluate the hybrid *** findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict *** results show that,independent of the metaheuristic used to guide the model selection,optimized extreme learning machines attained the best performance scores according to six *** hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.

关键词： Total organic carbon Hybrid models Automated machine learning Evolutionary algorithms Geology

The inception of a Paleotethyan magmatic arc in Iberia

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Geoscience Frontiers 2015年第2期6卷 297-306页

作者： M.F.pereira.a.c.stro c.Fernández IDL Departamento de Geociências ECT Universidade de évora Departamento de Geología Universidad de Huelva Departamento de Geodinámica y Paleontología Universidad de Huelva

This paper presents a compilation of recent U-Pb （zircon） ages of late carboniferous-early Permian （Lc EP） calc-alkaline batholiths from lberia, together with a petrogenetic interpretation of magma generation based on comparisons with Mesozoic and Tertiary cordilleran batholiths and experimental melts. Zircon U-Pb ages distributed over the range ca. 315-280 Ma, indicate a linkage between calc-alkaline magmatism, Iberian orocline generation and Paleotethys subduction. It is also shown that Iberian Lc-EP calcalkaline batholiths present unequivocal subduction-related features comparable with typical cordilleran batholiths of the Pacific Americas active margin, although geochemical features were partially obscured by local modifications of magmas at the level of emplacement by country rock assimilation. When and how Lc-EP calc-alkaline batholiths formed in Iberia is then discussed, and a new and somewhat controversial interpretation for their sources and tectonic setting （plume-assisted relamination） is suggested. The batholiths are proposed to have formed during the subduction of the Paleotethys oceanic plate （Pangaea self-subduction） and, consequently, they are unrelated to Variscan collision. The origin of the Iberian batholiths is related to the Eurasian active margin and probably represents the inception of a Paleotethvan arc in the core of Pangaea.

关键词： Permo-carboniferous calc-alkaline arc-related batholiths Pangaea Paleotethys subduction Variscan and cimmerian cycles

An Optimized Divide-and-conquer Algorithm for the closest-Pair Problem in the Planar case

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Journal of computer Science & Technology 2012年第4期27卷 891-896页

作者： José c.pereira Fernando G.Lobo Department of Electronics and computer Science University of AlgarveCampus de Gambelas8005-139 FaroPortugal Center for Environmental and Sustainability ResearchCampus de Caparica2829-516 CaparicaPortugal

We present an engineered version of the divide-and-conquer algorithm for finding the closest pair of points, within a given set of points in the XY-plane. For this version of the algorithm we show that only two pairwise comparisons are required in the combine step, for each point that lies in the 25-wide vertical slab. The correctness of the algorithm is shown for all Minkowski distances with p ≥ 1. We also show empirically that, although the time complexity of the algorithm is still O（n lgn）, the reduction in the total number of comparisons leads to a significant reduction in the total execution time, for inputs with size sufficiently large.

关键词： geometrical problem and computation closest-pair problem Basic-2 algorithm

crystal structure and magnetic properties of YbZn_(0.7)In_(1.3)

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Journal of Rare Earths 2011年第10期29卷 943-945页

作者： Yu.Verbovytskyy L.c.J.pereira A.P.Gon alves Department of chemistry Nuclear and Technological InstituteNational Rd.102686-953SacavémPortugal

The new ternary YbZn0.7Inl.3 compound was synthesized in evacuated quartz ampoules at 900 ℃, followed by annealing at 400 ℃. It crystallized in the UHg2 structure type with a=0.47934（5） nm, c=0.36955（5） nm, V=0.073535（15） nm3. The shortest distances between the atoms in this structure were equal to 0.3696 nm （Yb-Yb）, 0.3328 nm （Yb-M） and 0.2767 nm （M M）, respectively. Magnetization measurements indicated that the title compound exhibited a paramagnetic behavior down to 2 K, with antiferromagnetic-like interactions. calculated magnetic moment for YbZn0.7inl.3 （μeft =3.86μB/Yb） could indicate mixed valence state of Yb.

关键词： ytterbium intermetallics crystal structure magnetic measurements rare earths

Biocompatibility and biotoxicity of in-situ synthesized carboxylated nanodiamond-cobalt oxide nanocomposite

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Journal of Materials Science & Technology 2017年第8期33卷 879-888页

作者： L.Syam Sundar Naser A.Anjum M.c.Ferro Eduarda pereira Manoj K.Singh A.c.M.Sousa TEMA-Department of Mechanical Engineering University ofAveiroAveiroPortugal cESAM-centrefor Environmental&Marine Studies and Department of chemistry University of Aveiro3810-193AveiroPortugal cIcEcO Department of Material Engineering and CeramicsUniversity of AveiroPortugal

A nanocomposite that incorporates cobalt oxide（co3O4） and nanodiamond（ND） can present both high magnetism（co3O4） and high hardness（ND）. ND particles have potential applications in a variety of fields such as protein immobilization, biosensors, therapeutic molecule delivery and bio-imaging. However,limited information is available in literature on the in-situ synthesis of biocompatible magnetic materials and also on their potential biotoxicity as a result of their entry into environmental compartments and subsequent interaction with biota. In this work, a new kind of bio-compatible magnetic material –carboxylated nanodiamond（c ND） and co3O4 was synthesized to obtain the c ND-co3O4 *** synthesis procedure involved in-situ and chemical reduction of cobalt chloride（cocl（26）H2O） and sodium borohydrate（NaBH4）. The synthesized cND-co3O4 nanocomposite was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The cyto-genotoxicity of the synthesized nanocomposite material was studied by using onion（Allium cepa L.） as a test model with concentrations of 5, 10 and 20 μg/ml. The study was also extended to cND and co3O4 materials for comparison purpose. co3O4 and cND exhibited their contrasting effects on mitosis and other cyto-genotoxic indices studied herein. This work provided fundamental data on the synthesis and the bio-toxicity of the c ND-co3O4 nanocomposite, which, in turn, can help to expand their multidisciplinary applications.

关键词： Nanodiamond cobalt oxide Nanodiamond Nanocomposite Bio-toxicity Allium cepa

On the quality requirements of demand prediction for dynamic public transport

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communications in Transportation Research 2021年第1期1卷 50-60页

作者： Inon Peled Kelvin Lee Yu Jiang Justin Dauwels Francisco c.pereira Danmarks Tekniske Universitet(DTU) TechnologyManagement and Economics Dept.Kgs.Lyngby2800Denmark Nanyang Technological University(NTU) Graduate College50 Nanyang AvenueSingapore637553 Delft University of Technology(TU Delft) Microelectronics Dept.2600Netherlands

As Public Transport(PT)becomes more dynamic and demand-responsive,it increasingly depends on predictions of transport *** how accurate need such predictions be for effective PT operation?We address this question through an experimental case study of PT trips in Metropolitan copenhagen,Denmark,which we conduct independently of any specific prediction ***,we simulate errors in demand prediction through unbiased noise distributions that vary considerably in *** the noisy predictions,we then simulate and optimize demand-responsive PT fleets via a linear programming formulation and measure their *** results suggest that the optimized performance is mainly affected by the skew of the noise distribution and the presence of infrequently large prediction *** particular,the optimized performance can improve under non-Gaussian *** *** also find that dynamic routing could reduce trip time by at least 23%*** *** reduction is estimated at 809,000€/year in terms of Value of Travel Time Savings for the case study.

关键词： Dynamic public transport Demand forecasting Non-Gaussian noise Predictive optimization

Are extrafloral nectaries efficient against herbivores? Herbivory and plant defenses in contrasting tropical species

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Journal of Plant Ecology 2020年第4期13卷 423-430页

作者： cássio cardoso pereira Maria Gabriela Boaventura Gislene carvalho de castro Tatiana cornelissen Departamento de Genética Ecologia e EvoluçãoUniversidade Federal de Minas Gerais31270-910 Belo HorizonteMGBrazil Departamento de ciências Naturais Universidade Federal de São João del-Rei36301-160 São João del-ReiMGBrazil

Aims Plants have limited resources for defenses and species that invest in biotic defenses might exhibit leaves that invest less in other types of *** have investigated whether plants that have few mechanical defenses,but have extrafloral nectaries(EFNs)patrolled by ants,are less prone to herbivory,compared with plants without EFNs that have tougher *** Data from the literature were extracted to examine the reported levels of herbivory in plants with or without *** a savanna vegetation in southern Brazil,field data were collected in leaves from six tropical species and herbivory and specific leaf area(SLA)levels were *** further evaluated differences in herbivory and SLA among species and between plants with or without *** order to test the relationship between herbivory and leaf toughness we regressed average herbivory and average SLA per *** Findings Plants exhibited variable levels of leaf damage,but plants without ant defenses experienced the highest levels of leaf area loss to *** of mechanical defenses were also variable among the plant *** without EFNs were tougher,exhibiting lower values of *** plants without EFNs had more sclerophyllous leaves,this mechanical defense was not sufficient to impair and/or reduce herbivore feeding,suggesting that the biotic defenses performed by patrolling ants might be more effective than investment in mechanical defenses associated with leaf palatability.

关键词： ants biotic defenses herbivory leaf palatability specific leaf area

Optimization of an innovative approach involving mechanical activation and acid digestion for the extraction of lithium from lepidolite

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International Journal of Minerals,Metallurgy and Materials 2018年第1期25卷 11-19页

作者： Nathalia Vieceli carlos A.Nogueira Manuel F.c.pereira Fernando O.Durao carlos Guimaraes Fernanda Margarido center for Innovation Technology and Po icy Research-IN+Instituto Superior T6cnicoUniversity of Lisbon1049-001 LisboaPortugal LNEG-Laborat6rio Nacional de Energia e Geologia I.P.Campus do Lumiar1649-038 LisboaPortugal cERENA-centro de Recursos Naturais e Ambiente DECivilInstituto Superior T6cnicoUniversity of Lisbon1049-001 LisboaPortugal

The recovery of lithium from hard rock minerals has received increased attention given the high demand for this element. There- fore, this study optimized an innovative process, which does not require a high-temperature calcination step, for lithium extraction from le- pidolite. Mechanical activation and acid digestion were suggested as crucial process parameters, and experimental design and re- sponse-surface methodology were applied to model and optimize the proposed lithium extraction process. The promoting effect of amorphi- zation and the formation of lithium sulfate hydrate on lithium extraction yield were assessed. Several factor combinations led to extraction yields that exceeded 90%, indicating that the proposed process is an effective approach for lithium recovery.

关键词： lepidolite lithium mechanical activation acid digestion optimization extraction

Litter production and leaf nutrient concentration and remobilization in response to climate seasonality in the central Amazon

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Journal of Forestry Research 2024年第3期35卷 131-141页

作者： Ricardo Antonio Marenco Saul Alfredo Antezana-Vera Daniela pereira Dias Luiz Antonio candido Instituto Nacional de Pesquisas da Amazonia Coordenagao de Uso da Terra e Mudanca ClimaticaAv.Andre Araujo 2936ManausAM69067-375Brazil Programa de pos-Graduagao em Agricultura no Tropico Umido Instituto Nacional de Pesquisas da Amazonia-INPAManausAMBrazil Unidade Academica de ciencias Agrarias Universidade Federal de JataiBR 364km 195JataiGO 75801-615Brazil

Litterfall is the largest source of nutrients to for-est soils of tropical ***,variability in lit-terfall production,nutrient remobilization,and changes in leaf nutrient concentration with climate seasonality remain largely unknown for the central *** study meas-ured litterfall production,leaf nutrient remobilization,and leaf area index on a forest plateau in the central *** was measured at monthly intervals during 2014,while nitrogen,phosphorus,potassium,calcium and mag-nesium concentrations of leaf litter and canopy leaves were measured in the dry and rainy seasons,and remobilization rates *** area index was also recorded in the dry and rainy *** litterfall varied from 33.2(in the rainy season)to 87.6 g m^(-2) in the dry season,while leaf area index increased slightly in the rainy *** seasonality had no effect on concentrations of nitrogen,calcium,and magnesium,whereas phosphorous and potassium responded to rainfall seasonality *** phosphorous increased,potassium decreased during the dry *** seasons,nitrogen,potassium,and phosphorous decreased in leaf litter;calcium increased in leaf litter,while magnesium remained unaffected with leaf ***,the five nutrients had similar remobilization rates over the *** absence of climate seasonality on nutrient remobilization suggests that the current length of the dry season does not alter nutrient remobilization rates but this may change as dry periods become more prolonged in the future due to climate change.

关键词： Throughfall Nutrient cycling climatic seasonality Leaf mass per area