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Microstructural characterization and mechanical behavior analysis of 7075-T6 aluminum subjected to simulated lightning strikes

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Chinese Journal of Aeronautics 2021年第12期34卷 39-50页

作者： Luis Henrique SANTOS Weslei Patrick Teodosio sousa Sara silva Ferreira DE daFE Pedro Americo Magalhaes junior Department of Mechanical Engineering Pontificia Universidade Catolica de Minas GeraisBelo Horizonte 30535-901Brazil

Aircrafts damages caused by lightning strikes have been known since the early days of ***,the physical effects on the aircraft structure are still being *** work seeks to evaluate the lightning strike effects in the aluminum alloy *** were submitted to lightning strike simulation in laboratory and the damages evaluated through characterization *** and profilometry tests have shown material loss to 0.272 mm depth in the damaged *** addition,it was detected the material accumulation occurrence in the damage vicinity of the *** the damage,it was found a region where metallurgical changes were *** tensile and microhardness tests results have shown reduction in the percentage elongation and hardness increasing in the material affected by *** results are corroborated by the X-Ray Diffraction(XRD)and Rietveld Method(red line)that indicated an increasing in dislocation density and micro-deformation in the material *** microscopy results have shown the presence of microcracks on the normal and cross-section surface of the samples *** Energy Dispersive X-Ray Spectroscopy(EDXS)and Electron Backscattered Diffraction Test(EBSD)found coarse intermetallic phases and precipitates compounds with dimensions greater than 1 lm in *** were responsible for nucleation of the microcracks that propagate along the material grain boundaries.

关键词： Aircraft structure Characterization techniques Lightning strikes Precipitates Microcracks

Prognosis of forest production using machine learning techniques

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Information Processing in Agriculture 2023年第1期10卷 71-84页

作者： Jeferson Pereira Martins silva Mayra Luiza Marques da silva Adriano Ribeiro de Mendonca Gilson Fernandes da silva Antoˆnio Almeida de Barros junior Evandro Ferreira da silva Marcelo Otone Aguiar Jeangelis silva Santos Nı´vea Maria Mafra Rodrigues Federal University of Espirito Santo UFESDepartment of Forestry and Wood ScienceAvenue Governor Lindemberg31629550-000 Jeroˆnimo MonteiroESBrasil b Departamento de Cieˆncias Agra´riasUniversidade Federal de Sa o Joa del-Rei Sete Lagoas CampusHighway MG 424-Km 47Sete LagoasMinas Gerais 35701-970Brazil Federal University of Para(UFPA) University Campus of AltamiraStreet Cel.Jose Porfırio2515Sa o Sebastiao68372-040 AltamiraPABrazil

Forest production and growth are obtained from statistical models that allow the generation of information at the tree or forest stand *** the use of regression models is common in forest measurement,there is a constant search for estimation procedures that provide greater ***,machine learning techniques have been used with satisfactory performance in measuring ***,methods such as Adaptive NeuroFuzzy Inference System(ANFIS)and Random Forest are relatively poorly studied for predicting the volume of wood in eucalyptus plantations in ***,it is essential to check whether these techniques can provide gains in terms of ***,this study aimed to evaluate the use of Random Forest and ANFIS techniques in the prognosis of forest *** data used come from continuous forest inventories carried out in stands of eucalyptus *** data were divided into 70%for training and 30%for *** algorithms used to generate rules in ANFIS were Subtractive Clustering and ***,training was done with the hybrid algorithm(descending gradient and least squares)with the number of seasons ranging from 1 to *** RFs were trained,varying the number of trees from 50 to 850 and the number of observations by five leaves to *** neural networks and decision trees were also trained to compare the feasibility of the *** evaluation of the estimates generated by the techniques for training and validation was calculated based on the following statistics:correlation coefficient(r),relative Bias(RB),and the relative root mean square error(RRMSE)in *** general,the techniques studied in this work showed excellent performance for the training and validation data set with RRMSE values*** RF presented inferior statistics about the ANFIS for the prognosis of forest *** Subtractive Clustering(SC)and Fuzzy-C-Means(FCM)algorithms provide accurate baseline

关键词： Artificial Intelligence Ensemble Learning Forest Measurement Forest inventory Artificial Neural Networks Regression

High-throughput phenotyping of two plant-size traits of Eucalyptus species using neural networks

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Journal of Forestry Research 2022年第2期33卷 591-599页

作者： Marcus Vinicius Vieira Borges Janielle de Oliveira Garcia Tays silva Batista Alexsandra Nogueira Martins silva Fabio Henrique Rojo Baio Carlos Antônio da silva junior Gileno Brito de Azevedo Glauce Taís de Oliveira sousa Azevedo Larissa Pereira Ribeiro Teodoro Paulo Eduardo Teodoro Federal University of Mato Grosso Do Sul(UFMS) Chapadão Do SulMato Grosso Do Sul 79560000Brazil Department of Geography State University of Mato Grosso(UNEMAT)SinopMato Grosso 78555000Brazil

In forest modeling to estimate the volume of wood,artificial intelligence has been shown to be quite effi-cient,especially using artificial neural networks(ANNs).Here we tested whether diameter at breast height(DBH)and the total plant height(Ht)of eucalyptus can be pre-dicted at the stand level using spectral bands measured by an unmanned aerial vehicle(UAV)multispectral sensor and vegetation *** do so,using the data obtained by the UAV as input variables,we tested different configurations(number of hidden layers and number of neurons in each layer)of ANNs for predicting DBH and Ht at stand level for different Eucalyptus *** experimental design was randomized blocks with four replicates,with 20 trees in each experimental *** treatments comprised five Eucalyptus species(***,***,***,***-dis,and ***)and Corymbria *** and Ht for each plot at the stand level were measured seven times in separate overflights by the UAV,so that the multispectral sensor could obtain spectral bands to calculate vegetation indices(VIs).ANNs were then constructed using spectral bands and VIs as input layers,in addition to the categorical variable (species), to predict DBH and Ht at the stand level simultaneously. This report represents one of the first appli-cations of high-throughput phenotyping for plant size traits in Eucalyptus species. In general, ANNs containing three hidden layers gave better statistical performance (higher esti-mated r, lower estimated root mean squared error-RMSE) due to their greater capacity for self-learning. Among these ANNs, the best contained eight neurons in the first layer, seven in the second, and five in the third (8 − 7 − 5). The results reported here reveal the potential of using the gener-ated models to perform accurate forest inventories based on spectral bands and VIs obtained with a UAV multispectral sensor and ANNs, reducing labor and time.

关键词： Computational intelligence Diameter at breast height Forest inventory Remote sensing Vegetation indices

Plant community on a volcano mountaintop reveals unique high-altitude vegetation in southeastern Brazil

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Journal of Mountain Science 2024年第9期21卷 3018-3030页

作者： Igor Musauer KESSOUS Ruy JoséValka ALVES Nílber Gonçalves da silva Amilcar Walter SAPORETTI junior Biodiversity Laboratory Federal Institute of EducationScience and Technology of Southern Minas Gerais(IFSULDEMINAS)Av.Dirce Pereira Rosa300-Jardim Esperança37713-100Poços de CaldasMGBrazil Department of Botany National MuseumFederal University of Rio de JaneiroQuinta da Boa Vista s.n.São Cristóvão20949-040Rio de JaneiroRJBrazil Gothenburg Global Biodiversity Centre Carl Skottsbergs Gata 22BSE 41319GothenburgSweden

Mountains exhibit a high degree of endemism and diversity,however,quantifying their biodiversity can be *** to islands,species isolation in mountainous regions results in comparable patterns of evolution and extinction,rendering their biodiversity unique and highly susceptible to anthropogenic *** topographic relief in mountains plays a crucial role in creating habitat complexity,which in turn contribute to high plant ***,we investigated plant diversity in the volcano mountaintop vegetation on the Poços de Caldas Plateau,a region situated in the ecotone between the Atlantic Forest and Cerrado,characterized by natural radiation and significant anthropogenic *** employed an automated approach through the filtering of georeferenced and non-georeferenced data to obtain a list of plant species in the ***,we statistically investigated the similarity among different high-altitude vegetations belonging to the campos de altitude from the Atlantic Forest and campos rupestres from the *** plateau exhibits high plant diversity,including 1,659 specific and infraspecific taxa,especially belonging to Asteraceae and *** analyses suggest that geographical distance is a strong predictor of dissimilarity and that the Poços de Caldas Plateau is more floristically related to the campos rupestres,despite being associated with campos de *** region possesses a unique set of biodiversity,indicating that it may be a distinct ***,we hypothesize that Pleistocene events likely influenced the conformation of the current floristic composition in the region through species interchange between the Cerrado and Atlantic *** study also highlights the few taxa assessed for conservation status and anthropogenic threats that this habitat is facing.

关键词： Atlantic Forest Biogeography Cerrado Community ecology Grassland

Antiglycation and antioxidant activities of the crude extract and saponin fraction of Tribulus terrestris before and after microcapsule release

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Journal of Integrative Medicine 2022年第2期20卷 153-162页

作者： Célia Cristina Malaguti Figueiredo Amanda da Costa Gomes Filipe Oliveira Granero Joao Luiz Bronzel junior Luciana Pereira silva Valdecir Farias Ximenes Regildo Márcio Goncalves da silva Institute of Chemistry São Paulo State UniversityAraraquaraSão Paulo 14800-060Brazil Educational Foundation of the City of Assis AssisSão Paulo 19807-130Brazil Department of Chemistry School of SciencesSão Paulo State UniversityBauruSão Paulo 17033-360Brazil Department of Biotechnology School of SciencesHumanities and LanguagesSão Paulo State UniversityAssisSão Paulo 19806-900Brazil

Objective:The present study investigated antiglycation and antioxidant activities of crude dry extract and saponin fraction of Tribulus *** also developed a method of microencapsulation and evaluated antiglycation and antioxidant activities of crude dry extract and saponin fraction before and after microcapsule ***:Antiglycation activity was determined by relative electrophoretic mobility(REM),free amino groups and inhibition of advanced glycation end-product(AGE)*** activity was determined by 2,2-diphenyl-1-picrylhydrazyl(DPPH),ferric ion-reducing antioxidant power(FRAP),nitric oxide(NO)and thiobarbituric acid reactive species(TBARS)*** were prepared using maltodextrin as wall material and freeze-drying as encapsulation *** characterization of microcapsules was evaluated by scanning electron microscopy,and encapsulation efficiency and microcapsule release were determined by total saponins *** and antioxidant assays were performed using crude dry extract and saponin fraction of *** before and after ***:Saponin fraction showed an increase of 32.8%total ***-performance liquid chromatography-mass spectrometry analysis showed the presence of saponins in the obtained *** evaluation by REM demonstrated that samples before and after release presented antiglycation activity similar to bovine serum albumin treated with ***,samples inhibited AGE formation,highlighting treatment with saponin fraction after release(89.89%).Antioxidant tests demonstrated antioxidant activity of the *** dry extract before encapsulation presented the highest activities in DPPH(92.00%)and TBARS(32.49%)*** fraction before encapsulation in FRAP test(499μmol Trolox equivalent per gram of dry sample)and NO test(15.13μmol nitrite formed per gram of extract)presented the highest ***:This study presen

关键词： Glycation Microencapsulation Oxidative stress Saponins Tribulus terrestris

Development of Junction Elements from Study of the Bionics

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Journal of Bionic Engineering 2007年第1期4卷 41-46页

作者： Wilson Kindlein junior Luis Henrique Alves Cndido André Canal Marques Sandra Souza dos Santos Maurício da silva Viegas Laboratory of Design and Material Selection-LdSM-Materials Department (DEMAT) School of Engineering–EE Federal University of Rio Grande do Sul-Brazil-UFRGS Brazil

The applications of bionic methodology developed by the Laboratory of Design and Material Selection as basis in the creation of junction elements were demonstrated. These elements favor the application of Ecodesign in reference to the effectiveness of product dismount aiming the reduction of ambient impact in all its phases of use. The creation, the development and the confection of new junction elements were described, and case studies of new products developed specifically with this purpose were presented.

关键词： bionics Ecodesign junction elements

Mergers and Acquisitions: An Efficiency Evaluation

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Applied Mathematics 2013年第11期4卷 1583-1589页

作者： Paulo Rotela junior Edson de Oliveira Pamplona Aneirson Francisco da silva Institute of Production Engineering and Management Federal University of ItajubaItajubaBrazil Departament of Production Sao Paulo State UniversityGuaratinguetaBrazil

This article sheds light on how synergies arise through mergers and acquisitions (M&A). Enterprises go through the process of Mergers and Acquisitions (M&A) with the goal of improving performance, increasing efficiency and obtaining business synergy. Prior literature suggests that synergies could arise due to taxes, market power or efficiency improvements. This study evaluates the efficiency of M&A in Brazil among publicly-traded companies. We used models with multiple objectives from Goal Programming and data Envelopment Analysis (GPDEA), employing accounting indicators as input and output variables, and thus evaluated the emergence of synergy gains. These models allow us to analyze and classify the M&A according to the efficiency obtained in such processes. Some of the M&A cases analyzed were mistakenly considered efficient when used traditional models. And, as expected, the GPDEA was proved to be superior to classical models;however it was noticed that few of the cases investigated were proved to be effective. We presented a new application for multi-objective approach that can be used to assess mergers and acquisitions. The dualapplication of GPDEA provided a greater understanding of efficiency generation in synergy creation by means of M&A.

关键词： Merger and Acquisition Multiple-Objective Optimization Goal Programming data Envelopment Analysis Synergy

Gangliosides in nervous system development,regeneration,and pathologies

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Neural Regeneration Research 2023年第1期18卷 81-86页

作者： Juliana F.Vasques Renata Guedes de Jesus Gonçalves Almir Jordão da silva-junior Robertta silva Martins Fernanda Gubert Rosalia Mendez-Otero Instituto de Ciências Biomédicas Universidade Federal do Rio de JaneiroRio de JaneiroBrazil Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de JaneiroRio de JaneiroBrazil Programa Redes de Pesquisa em Saúde no Estado do Rio de Janeiro Rio de JaneiroBrazil Programa Rede NanoSaúde do Estado do Rio de Janeiro Rio de JaneiroBrazil Instituto Nacional de Ciência e Tecnologia em Medicina Regenerativa Rio de JaneiroBrazil

Gangliosides,sialic acid-containing sphingolipids,are major constituents of neuronal *** to the number of sialic acids and the structure of the oligosaccharide chain,gangliosides can be classified as simple or complex and grouped in different *** of gangliosides have been identified in vertebrate cells,with different expression patterns during development and related to several physiological processes,especially in the nervous *** GD3 and its O-acetylated form,9acGD3,are highly expressed in early developmental stages,GM1,GD1a,GD1b,and GT1b are the most abundant ganglioside species in the mature nervous *** in enzymes involved in ganglioside metabolism can lead to the accumulation of specific species,a condition termed gangliosidosis and usually marked by severe neurological *** in ganglioside levels have also been described in several neurodegenerative diseases,such as Alzheimer’s and Parkinson’*** this review,we summarized recent information about the roles of GD3,9acGD3,GM1,GD1a,GD1b,GT1b,and other ganglioside species in nervous system development and regeneration,as well as clinical trials evaluating possible therapeutic applications of these molecules.

关键词： 9acGD3 gangliosides GD1a GD1b GD3 glycolipids GM1 GM2 GM3 GM4 GT1b

Formation of DNA Strand Breaks in Peripheral Lymphocytes of Rats After Exposure to Natural Sunlight

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Biomedical and Environmental Sciences 2012年第2期25卷 245-249页

作者： Dorival Mendes RODRIGUES-junior Ana Amélia de CARVALHO MELO Benedito Borges da silva Pedro Vitor LOPES-COSTA Department of Biology Federal University of Piaui-TeresinaPiauiBrazil Department of Gynecology Federal University of Piaui-TeresinaPiauiBrazil

Objective This paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil（5oS,42oW）.Materials and Methods Thirty Wistar-Hannover rats,three months old,were randomly divided into three groups of 10 animals each：Group I [control,without exposure to ultraviolet（UV） radiation],Group II（exposed to sunlight during 08：00 *** 10：00 a.m.）,and Group III（exposed to sunlight during 10：00 *** 12：00 a.m.）.After a week of exposure,peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per *** 24 h after exposure to sunlight in Group III,a new collection was obtained to observe the repair *** alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight（P0.05）.Results There was no statistical difference between Group I and II（P=0.672）.On the other hand,the exposure to sunlight in Group III showed genotoxic action in comparison to the other groups（P0.0001）.Also,there was no significant repair in Group III R（P=0.407）.Conclusion This study has shown a genotoxic potential of sunlight（UVA-B） in lymphocytes of mammals from 10：00 *** 12：00 a.m.,due to a higher intensity of UV in this tropical region.

关键词： Comet assay DNA damage Rats Sunlight Ultraviolet radiation