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A computer vision system for early detection of anthracnose in sugar mango(Mangifera indica)based on UV-A illumination

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Information Processing in Agriculture 2023年第2期10卷 204-215页

作者： Leonardo Ramırez Alberto Carlos Eduardo Cabrera Ardila Flavio Augusto Prieto Ortiz facultad de ingenierı´a Universidad Nacional de ColombiaBogota´D.C.111321Colombia

The present work describes the development of a computer vision system for the early detection of anthracnose in sugar mango based on Ultraviolet A illumination(UV-A).Anthracnose,a disease caused by the fungus Colletotrichum sp,is commonly found in the fruit of sugar mango(Mangifera indica).It manifests as surface defects including black spots and is responsible for reducing the quality of the ***,it decreases its commercial *** more detail,this study poses a system that begins with image acquisition under white and ultraviolet ***,it proposes to analyze the Red,Green and Blue color information(R,G,B)of the pixels under two types of illumination,using four different methods:RGB-threshold,RGB-Linear Discriminant Analysis(RGBLDA),UV-LDA,and *** analysis produces an early semantic segmentation of healthy and diseased areas of the mango *** results showed that the combination of the linear discriminant analysis(LDA)and UV-A light(called UV-LDA method)in sugar mango images allows early detection of ***,this method achieves the identification of the disease one day earlier than by an expert with respect to the scale of anthracnose severity implemented in this work.

关键词： Sugar mango Anthracnose LDA UV-A light Grading Image processing

design and Manufacturing Strategies for Fused deposition Modelling in Additive Manufacturing:A Review

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Chinese Journal of Mechanical Engineering 2019年第3期32卷 1-16页

作者： Hugo I.Medellin-Castillo Jorge Zaragoza-Siqueiros Advanced design and Manufacturing Laboratory Facultad de IngenieríaUniversidad Autónoma de San Luis Potosí

Although several research works in the literature have focused on studying the capabilities of additive manufacturing(AM) systems, few works have addressed the development of design for Additive Manufacturing(DfAM) knowledge,tools, rules, and methodologies, which has limited the penetration and impact of AM in industry. In this paper a comprehensive review of design and manufacturing strategies for Fused deposition Modelling(FDM) is ***, several DfAM strategies are proposed and analysed based on existing research works and the operation principles, materials, capabilities and limitations of the FDM process. These strategies have been divided into four main groups: geometry, quality, materials and sustainability. The implementation and practicality of the proposed DfAM is illustrated by three case studies. The new proposed DfAM strategies are intended to assist designers and manufacturers when making decisions to satisfy functional needs, while ensuring manufacturability in FDM ***, many of these strategies can be applied or extended to other AM processes besides FDM.

关键词： Additive manufacturing(AM) design for additive manufacturing(DfAM) Fused deposition Modelling(FDM) design and manufacturing strategies

Synthesis of activated carbons from black sapote seeds,characterization and application in the elimination of heavy metals and textile dyes

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Chinese Journal of Chemical Engineering 2020年第2期28卷 613-623页

作者： Alejandra Alicia Peláez-Cid Vincent Romero-Hernández Ana María Herrera-González Alejandro Bautista-Hernández Oscar Coreno-Alonso facultad de ingeniería Benemérita Universidad Autónoma de PueblaMexico Instituto de Ciencias Básicas e ingeniería Universidad Autónoma del Estado de HidalgoMexico División de ingenierías Universidad de GuanajuatoMexico

Many different techniques may be used to remove industrial pollutants from wastewater. Adsorption using activated carbon has been reported to be an effective method. This work proposes the use of a vegetable residue(black sapote seeds) as a raw material for its synthesis. These carbons were chemically activated using phosphoric acid and carbonized at 673 and 873 K. Adsorption isotherms were constructed for the textile dyes on the carbons, and this data was treated using Langmuir’s equation to quantitatively describe the adsorption process. The synthesized carbons were characterized using FTIR, EA, SEM, Nitrogen adsorption(specific surface areas of 879 and 652 m2·g-1), and their points of zero charge(2.1 and 2.3). It was possible to adsorb both heavy metals and textile dyes present in aqueous solutions and wastewaters using these activated carbons. Heavy metals were adsorbed almost completely by both carbons. Cationic dyes where adsorbed(58–59.8 mg·g-1) in greater amounts compared to anionic dyes(10–58.8 mg·g-1). The amount of anionic dyes adsorbed increased almost 30% by changing the pH of the solutions. One of the carbons was thermally regenerated on three occasions without losing its adsorption capacity and it was proved in a flow system.

关键词： Activated carbons Black sapote seeds Heavy metal adsorption Textile dye adsorption Wastewater treatment

A comprehensive analysis of future solar energy potential variations using a CMIP6 multi-model ensemble approach in Colombia

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Clean Energy 2024年第4期8卷 79-89页

作者： Heli AArregocés Roberto Rojano Daiver Pinto Pimienta Grupo de Investigación GISA Facultad de IngenieríaUniversidad de La GuajiraRiohachaColombia Grupo Procesos Fisicoquímicos Aplicados Facultad de IngenieríaUniversidad de Antioquia SIU/UdeACalle 70 No.52–21MedellínColombia Grupo desarrollo de Estudios y Tecnologías Ambientales del Carbono(deSTACAR) Facultad de IngenieríaUniversidad de La GuajiraRiohachaColombia

Climate change is predicted to significantly impact solar energy generation,which is particularly concerning given that photovoltaic(PV)energy is critical to the global transition to clean energy in underdeveloped *** study analyses the PV potential variations in Colombia using a Coupled Model Intercomparison Project Phase 6(CMIP6)multi-model ensemble approach under two shared socio-economic pathway scenarios for the near(2025-50)and far(2051-2100)*** the near-future period,the Pacific,Andean and Orinoquía regions are expected to experience a decrease in PV potential ranging from 10%to 23%for all shared socio-economic *** will be particularly noticeable during the March/April/May and June/July/August *** the other hand,CMIP6 estimations indicate a 1-4%increase in PV potential across the Amazon region during the June/July/August and September/October/November *** the far future,it has been projected that the Pacific,Andean and Orinoquía regions may experience a significant decline in solar power generation due to increased cloud cover and reduced *** decrease in PV potential during the June/July/August season could range from 8%to 27%for all considered scenarios,with the Pacific region being the most *** Pacific region is projected to experience a decrease ranging from 10%to 35%for all *** is worth noting that there are noticeable differences in PV potential across various regions,which can result in changes in cloud cover and atmospheric ***,the study provides valuable insights into the PV potential in Colombia and highlights the importance of considering regional variations and climate change scenarios in future energy planning.

关键词： photovoltaic potential CMIP6 solar photovoltaic energy climate change Colombia

development and screening of(Ca-P-Si-F)-PEO coatings for biodegradability control of Mg-Zn-Ca alloys

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Journal of Magnesium and Alloys 2022年第8期10卷 2220-2237页

作者： Lara Moreno Marta Mohedano Raul Arrabal Endzhe Matykina departamento de ingeniería Química y de Materiales Facultad de Ciencias QuímicasUniversidad Complutense de Madrid28040 MadridSpain

PEO coatings were developed on MgZnxCayalloys for biomedical applications using different treatment times and a novel transparent electrolyte containing Ca,P,Si and *** characteristics and chemical composition of studied materials were evaluated using scanning electron microscopy,X-ray diffraction and optical *** investigations were performed for uncoated and coated materials using potentiodynamic polarization,electrochemical impedance spectroscopy and hydrogen evolution measurements in three media(0.9wt.%NaCl,α-MEM and inorganic part ofα-MEM).Findings revealed that Zn-rich intermetallics favour the formation of large voids in the ***,P,F and Si are successfully incorporated into the *** consist of crystalline phases(Mg O,Mg F_(2)and Ca,Si-rich compounds)and amorphous *** and organic components ofα-MEM solution accelerate corrosion of the bare substrates but have no significant influence on the corrosion resistance of coated ***,inorganicα-MEM can be considered as an appropriate medium for fast screening of PEO *** relatively small amount of F content in the barrier layer facilitates early failure of the coatings,which show undercoating ***-rich intermetallic particles in the undercoating crevice induce a more aggressive corrosive environment and enhanced micro-galvanic couple effect with the Mg *** leads to faster degradation of the coated alloys compared to the bare substrates.

关键词： Magnesium Biomaterials Plasma electrolytic oxidation Corrosion

Wind power potential over northern South America using ERA5-Land global reanalysis

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Clean Energy 2024年第2期8卷 104-112页

作者： Heli A.Arregocés Guillermo J.Bonivento Roberto Rojano Grupo de Investigación GISA Facultad de IngenieríaUniversidad de La GuajiraRiohachaColombia Grupo Procesos Fisicoquímicos Aplicados Facultad de IngenieríaUniversidad de Antioquia SIU/UdeACalle 70 No.52-21MedellínColombia

The northernmost region of South America has great potential for wind energy production and is a strategic area for the energy tran*** analysed data from ERA5-Land global reanalysis from 1980 to 2020 to determine the wind power potential in this *** aim was to identify areas with a high potential for wind energy that could be used to supply energy in case of drought in the region or increases in fuel *** compared data from 19 meteorological stations located in Colombia with ERA5-Land reanalysis data to generate reliable information for the feasibility and operation of wind *** to our analysis,the Colombian Caribbean and Coastal Plain have monthly average wind speeds at 90 m ranging from 4.85 to 10.34 m/s and 3.79 to 6.62 m/s,*** on wind power density calculations,these regions have the highest wind power density in our study,with a monthly average of between 250 and 399 W/m^(2).The Caribbean Region had a 69%increase in wind power density from January to July compared with the annual *** wind power density in the plains increased from January to March,while the Mountain Region had higher anomalies from May to *** Alta Guajira and ParaguanáPeninsula have great potential to generate wind energy due to their privileged geographical *** ERA5 offers valuable information about wind availability in time and space,it cannot represent the influence of local effects on wind patterns for the Mountain Region.

关键词： onshore wind power wind power potential ERA5-Land global reanalysis wind speed

Alkali and Plasma-Treated Guadua angustifolia Bamboo Fibers:A Study on Reinforcement Potential for Polymeric Matrices

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Journal of Renewable Materials 2024年第8期12卷 1399-1416页

作者： Patricia Luna Juan Lizarazo-Marriaga Alvaro Mariño facultad de ingeniería Universidad Nacional de ColombiaBogotá11001Colombia facultad de Ciencias Universidad Nacional de ColombiaBogotá11001Colombia

This study focuses on treating Guadua angustifolia bamboo fibers to enhance their properties for reinforcement applications in composite ***(alkali)and physical(dry etching plasma)treatments were used separately to augment compatibility of Guadua angustifolia fibers with various composite *** influence of these treatments on the fibers’performance,chemical composition,and surface morphology were *** analysis indicated that alkali treatments reduced the tensile modulus of elasticity and strength of fibers by up to 40%and 20%,respectively,whereas plasma treatments maintain the fibers’mechanical *** spectroscopy revealed significant alterations in chemical composition due to alkali treatments,while plasma-treated fibers showed minimal *** examination through Scanning Electron Microscopy(SEM)revealed post-treatment modifications in both cases;alkali treatments served as a cleanser,eliminating lignin and hemicellulose from the fiber surface,whereas plasma treatments also produce rough *** results validate the impact of the treatments on the fiber mechanical performance,which opens up possibilities for using Guadua angustifolia fibers as an alternative reinforcement in composite manufacturing.

关键词： Bamboo fibers Guadua angustifolia alkali treatment dry etching plasma treatment composite reinforcement

Mechanical Behavior of Panels Reinforced with Orthogonal Plant Fabrics: Experimental and Numerical Assessment

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Journal of Renewable Materials 2024年第10期12卷 1791-1810页

作者： Martha L.Sánchez G.Capote Universidad Militar Nueva Granada Programa de Ingeniería CivilBogotá110111Colombia facultad de Ciencias Departamento de FísicaUniversidad Nacional de ColombiaBogotá111321Colombia

The construction sector is one of the main sources of pollution,due to high energy consumption and the toxic substances generated during the processing and use of traditional *** production of cement,steel,and other conventional materials impacts both ecosystems and human health,increasing the demand for ecological and biodegradable *** this paper,we analyze the properties of panels made from a combination of plant fibers and castor oil resin,analyzing the viability of their use as construction *** the research,orthogonal fabrics made with waste plant fibers supplied by a company that deals with the manufacture of furniture and craft products were *** fabrics were made with strips of plant fibers of the Calamus rotang,Bambusa vulgaris,Heteropsis flexuosa,and Salix viminalis *** improve their compatibility with the castor oil resin,a cold argon plasma treatment was *** effect of the treatment on the properties of the fibers and the panels was *** density,water absorption capacity,and swelling percentage were ***,compression,static bending,and linear buckling tests were carried *** study found that panels made with treated fiber fabrics exhibited a reduction of approximately 10%in absorption capacity and up to 35%in swelling percentage *** made with Bambusa vulgaris fabrics exhibited the highest strength and stiffness *** models were constructed using commercial finite element *** comparing the numerical results with the experimental ones,differences of less than 15%were seen,demonstrating that the models allow adequately predicting the analyzed *** comparing the values obtained with the characteristic values of oriented strand board,the results suggest that panels made with unconventional materials could replace commercial panels traditionally made with wood-based fibers and particles and other composite materials in several applications in the c

关键词： Unconventional materials nonstructural panels plantfibers surface treatment physical properties mechanical properties

Effective Interaction Force between an Electric Charge and a Magnetic Dipole and Locality (or Nonlocality) in Quantum Effects of the Aharonov–Bohm Type

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Chinese Physics Letters 2021年第3期38卷 39-43页

作者： Gianfranco Spavieri George T.Gillies Miguel Rodriguez Maribel Perez Centro de Física Fundamental Facultad de CienciasUniversidad de Los AndesMérida 5101Venezuela department of Mechanical and Aerospace Engineering University of VirginiaCharlottesvilleVA 22904USA departamento de Física Facultad de Ciencia y TecnologíaUniversidad de CaraboboNaguanagua 2001Venezuela Carrera de ingeniería Ambiental Facultad de IngenieríaUniversidad Nacional de ChimborazoRiobamba 100150Ecuador

Classical electrodynamics foresees that the effective interaction force between a moving charge and a magnetic dipole is modified by the time-varying total momentum of the interaction fields. We derive the equations of motion of the particles from the total stress-energy tensor, assuming the validity of Maxwell’s equations and the total momentum conservation law. Applications to the effects of Aharonov–Bohm type show that the observed phase shift may be due to the relative lag between interfering particles caused by the effective local force.

关键词： force. momentum interaction