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Modelling of the variation of granular base materials resilient modulus with material characteristics and humidity conditions

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Journal of Road Engineering 2024年第1期4卷 27-35页

作者： Jean-pascal Bilodeau Erdrick leandro perez-Gonzalez Ali Saeidi Departement de Genie Civil et Genie des Eaux Universite LavalQuebecG1V 0A6Canada Departement des Sciences Appliquees Universite du Quebeca ChicoutimiChicoutimiG7H 2B1Canada

This study aims to quantify the susceptibility of granular materials used in pavements to changes in moisture content and propose a correlation model to incorporate this susceptibility into seasonal *** fines content and the percentage of fractured coarse aggregates were identified as direct indicators of the resilient modulus susceptibility to changes in water *** results showed that the percentage of fractured coarse aggregates particles(FR)has a more significant impact on the resilient modulus(Er)of crushed granular materials used in pavement construction than the combined indicator of the fines content and sample volumetrics(nf).Crushed granular materials with a higher percentage of fractured coarse aggregates are relatively insensitive to changes in the degree of saturation,but become more sensitive as the fine fraction porosity *** adjusted model was proposed based on the existing formulation,but considers a complex parameter to describe and adjust the sensitivity of base granular materials to variations in moisture content with respect to fabrication charac-teristics,fines content and volumetric *** model shows that the variation of Er values is below10%for fully crushed granular ***,it reaches approximately±12%for materials with 75%of crushed coarse aggregates andþ40%and-25%for materials with FR=50%.This model could help select good ag-gregates characteristics and adjust grain-size distribution for environments where significant moisture content variations can occur in the pavement system,such as in the province of Quebec(Canada).As it is based on pa-rameters that can be easily determined or estimated,it also represents a valuable tool for detailed design and analysis that can consider material characteristics.

关键词： Resilient modulus Degree of saturation Humidity conditions Unbound granular materials pavement base

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population structuring of the ubiquitous stingless bee Tetragonisca angustula in southern Brazil as revealed by microsatellite and mitochondrial markers

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Insect Science 2017年第5期24卷 877-890页

作者： Flavio O. Francisco leandro R. Santiago Yuri M. Mizusawa Benjamin p. Oldroyd Maria C. Arias Departamento de Genetica e Biologia Evolutiva Instituto de Biociencias Universidade de Sao Paulo Rua do MatZo 277 - sala 320Sao Paulo SP Brazi Behaviour and Genetics of Social Insects Lab School of Life and Environmental Sciences A 12 University of Sydney Sydney NSW Australia

Tetragonisca angustula is one of the most widespread stingless bees in the Neotropics. This species swarms frequently and is extremely successful in urban envi- ronments. In addition, it is one of the most popular stingless bee species for beekeeping in Latin America, so nest transportation and trading is common. Nest transportation can change the genetic structure of the host population, reducing inbreeding and increasing homogenization. Here, we evaluate the genetic structure of 17 geographic populations of T. angustula in southern Brazil to quantify the level of genetic differentiation between populations. Analyses were conducted on partially sequenced mitochondrial genes and 11 microsatellite loci of 1002 workers from 457 sites distributed on the mainland and on 3 islands. Our results show that T. angustula populations are highly differentiated as demon- strated by mitochondrial DNA （mtDNA） and microsatellite markers. Of 73 haplotypes, 67 were population-specific. MtDNA diversity was low in 9 populations but microsatellite diversity was moderate to high in all populations. Microsatellite data suggest 10 genetic clusters and low level of gene flow throughout the studied area. However, physical barri- ers, such as rivers and mountain ranges, or the presence or absence of forest appear to be unrelated to population clusters. Factors such as low dispersal, different ecological con- ditions, and isolation by distance are most likely shaping the population structure of this species. Thus far, nest transportation has not influenced the general population structure in the studied area. However, due to the genetic structure we found, we recommend that nest transportation should only occur within and between populations that are genetically similar.

关键词： genetic structure islands Meliponini microsatellites mtDNA nest transportation

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Biochar Increases Diuron Sorption and Reduces the potential Contamination of Subsurface Water with Diuron in a Sandy Soil

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pedosphere 2019年第6期29卷 801-809页

作者： Fabiano ApETTER Tamara SFERREIRA Adilson pSINHORIN Larissa BLIMA Fernandes AALMEIDA leandro p.acheco Alexandre FSILVA Universidade Federal de Mato Grosso Instituto de Ciências Agrárias e AmbientaisSinop 78557-267(Brazil Universidade Federal do piauí Programa de Pós-Graduaçño em AgronomiaBom Jesus 64900-000(Brazil Universidade Federal de Mato Grosso Instituto de Ciencias NaturaisSociais e HumanasSinop 78557-267(Brazil Universidade Federal de Mato Grosso Instituto de Engenharia Agrícola e AmbientalRondonópolis 78735-000(Brazil Embrapa Milho e Sorgo Sete Lagoas 35701-970(Brazil

The herbicide diuron is widely used in agricultural areas in Brazil, whereas it has high potential for subsurface water contamination due to its physicochemical characteristics. Recent studies have demonstrated the potential of biochar as a sorbent and possible pesticide leaching mitigation. The objective of this study was to investigate the long-term effect of biochar application on the kinetics of sorption and desorption of diuron in a Cerrado Haplic plinthosol. Samples were collected in an experiment conducted in the field in a randomized block design consisting of the combination of two levels of fertilizer application (0 and 300 kg ha −1 of 5-25-15 formula of NpK fertilizers) and three doses of biochar (0, 16, and 32 Mg ha −1 ). The Freundlich isotherm accurately described the sorption of diuron in all treatments. Biochar application increased the sorption and reduced the desorption of diuron. This effect was attributed to the contribution of biochar to total organic carbon (C) and C in the humin fraction and to the increase in the reactivity of the humic acid and humin fractions, which was significantly highly correlated with the sorption coefficient ( K f ). A positive correlation between the partition coefficient of organic C and K f confirmed the importance of the soil organic compartment for the sorption of diuron. The higher diuron sorption and lower diuron desorption capacities of sandy soils after biochar application could reduce the potential risk of diuron leaching and contamination of subsurface water.

关键词： Herbicide Leaching partition coefficient persistence pyrogenic carbon Soil organic matter Sorption coefficient

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Experimental characterization of Ti6AI4V T joints welded through linear friction welding technique： microstructure and NDE

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Advances in Manufacturing 2016年第4期4卷 305-313页

作者： Antonello Astarita Mario Coppola Sergio Esposito Mariacira Liberini leandro Maio Ilaria papa Fabio Scherillo Antonino Squillace Department of Chemical Materials and ProductionEngineering University of Naples "Federico II" PiazzaleTecchio 80 80125 Naples Italy Fox Bit srl viale Luraghi presso consorzio I1 Sole80038 Pomigliano d'Arco NA Italy Leonardo Company S.p.A.- Aircraft Division Engineering -AT&D Manufacturing and Assembly Research andDevelopment Viale dell'Aeronantica s/n80038 Pomigliano d'Arco NA Italy Department of Industrial Engineering - Aerospace Division University of Naples "Federico II" Via Claudio 21 NaplesItaly

Linear friction welding （LFW） is an innovative solid-state welding technique that allows to manufacture joints with high mechanical properties. This technology has various applications in the aerospace field; in particular it is used to weld massive structural components made of Ti6A14V. This paper deals with the experimental study of Ti6A14V T-joints welded through LFW, with particular focus on the effectiveness of ultrasonic control in detecting and distinguishing welding defects within the joints. Aiming to this scope, joints with different properties were manufactured and tested： some were free from defects but with different metallurgy, and some had different types of defects. The results obtained proved that the ultrasonic control was an effective method to detect and identify defects in linear friction welded titanium joints, moreover it was possible to get information regarding the microstructure and in particular the extension of the different metallurgical zones induced by the welding process.

关键词： Ti6A14V Ultrasonic control Linear frictionwelding (LFW) Microstructure Defects

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Clinical outcomes after intrastromal corneal ring segments reoperation in keratoconus patients

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International Journal of Ophthalmology(English edition) 2013年第6期6卷 796-800页

作者： Lconardo Torquetti Guilherme Ferrara Franklin Almeida leandro Cunha paulo Ferrara Jesus Merayo-Lloves Ferrara Eye Clinic Fernandez-Vega Eye Institute Hilton Rocha Foundation

AIM:To evaluate the clinical outcomes after Ferrara intrastromal corneal ring segments(ICRS)reoperation in patients with ***:A total of 37 keratoconus eyes implanted with intrastromal corneal ring segments,which had an ICRS exchange,addition,reposition or removal were *** visual acuity(UCVA),best corrected visual acuity(BCVA),keratometry(K),asphericity(Q)and pachymetry at the thinnest point(pTp)of the cornea were evaluated using a corneal tomography(Oculus pentacam,USA)RESULTS:The mean follow-up time after the reoperation was 30.5±9.7 *** mean UCVA improved from 20/300 to 20/80(p=0.005);the mean BCVA improved from 20/160 to 20/50(p=0.0002),the mean keratometry reduced from 49.33±4.19D to 46.16±3.90D(p=0.0001),the mean pachymetry at the thinnest point increased from 450±42.9μm to 469±40.8μm(p=0.0001).The asphericity increased from-0.84±0.74 to-0.35±0.81(p=0.15)and the spherical equivalent reduced from-4.64±4.87D to-3.04±3.45D(p=0.137).The changes in the asphericity and spherical equivalent were not statistically ***:Ferrara ICRS implantation showed to be a reversible and readjustable surgical procedure for keratoconus *** outcomes can be obtained even after removal,addition,reposition or exchange of ICRS.

关键词： keratoconus intrastromal corneal ring segments reoperation

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probiotic monotherapy and Helicobacter pylori eradication: A systematic review with pooled-data analysis

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World Journal of Gastroenterology 2018年第1期24卷 139-149页

作者： Giuseppe Losurdo Rossella Cubisino Michele Barone Mariabeatrice principi Gioacchino leandro Enzo Ierardi Alfredo Di Leo Section of Gastroenterology Department of Emergency and Organ TransplantationUniversity "Aldo Moro"Piazza Giulio Cesare National Institute of Gastroenterology "S De Bellis" Research Hospital

AIM To define probiotic monotherapy effect on Helicobacter pylori(H. pylori) status by performing a systematic *** Methods of analysis and inclusion criteria were based on pRISMA recommendations. Relevant publications were identified by searching pub Med, MEDLINE, Science Direct, and EMBASE. The end-point was to estimate eradication rate and urea breath test delta value before and after probiotic monotherapy across all studies and, overall, with a pooled data analysis. Adverse events of probiotic therapy were evaluated. The data were expressed as proportions/percentages, and 95%CIs were calculated. For continuous variables, we evaluated the weighted mean difference. Odd ratios(ORs) were calculated according to the peto method for the comparison of eradication rates between probiotics and *** Eleven studies were selected. probiotics eradicated H. pylori in 50 out of 403 cases. The mean weighted eradication rate was 14%(95%CI: 2%-25%, p =0.02). Lactobacilli eradicated the bacterium in 30 out of 235 patients, with a mean weighted rate of 16%(95%CI: 1%-31%). Saccharomyces boulardii achieved eradication in 6 out of 63 patients, with a pooled eradication rate of 12%(95%CI: 0%-29%). Multistrain combinations were effective in 14 out of 105 patients, with a pooled eradication rate of 14%(95%CI: 0%-43%). In the comparison of probiotics vs placebo, we found an OR of 7.91 in favor of probiotics(95%CI: 2.97-21.05, p probiotics induced a mean reduction in delta values higher than placebo(8.61% with a 95%CI: 5.88-11.34, vs 0.19% for placebo, p probiotics and placebo(OR = 1, 95%CI: 0.06-18.08).CONCLUSION probiotics alone show a minimal effect on H. pylori clearance, thus suggesting a likely direct role.

关键词： Helicobacter pylori probiotics eradication meta-analysis breath test

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Size effects on the tensile strength and fracture toughness of granitic rock in different tests

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2179-2192页

作者： Ignacio pérez-Rey Andrea Muñoz-Ibáñez Manuel A.González-Fernández Mauro Muñiz-Menéndez Miguel Herbón penabad Xian Estévez-Ventosa Jordi Delgado leandro RAlejano Laboratorio de Geotecnia CEDEXMadridSpain CINTECX GESSMin GroupDepartment of Natural Resources and Environmental EngineeringUniversidade de VigoVigoSpain School of Civil Engineering Universidade da CoruñaA CoruñaSpain

This study investigates the tensile failure mechanisms in granitic rock samples at different scales by means of different types of *** do that,we have selected a granitic rock type and obtained samples of different sizes with the diameter ranging from 30 mm to 84 *** samples have been subjected to direct tensile strength(DTS)tests,indirect Brazilian tensile strength(BTS)tests and to two fracture toughness testing *** DTS and fracture toughness were found to consistently grow with sample size,this trend was not clearly identified for BTS,where after an initial grow,a plateau of results was *** is a rather complete database of tensile related properties of a single rock *** if similar databases are rare,the obtained trends are generally consistent with previous scatter and partial experimental ***,different observations apply to different types of rocks and experimental *** differences in variability and mean values of the measured parameters at different scales are critically analysed based on the heterogeneity,granular structure and fracture mechanics *** potential relations between parameters are revised and an indication is given on potential sample sizes for obtaining reliable *** this database with different types of rocks is thought to be convenient to advance towards a better understanding of the tensile strength of rock materials.

关键词： Size effect Tensile strength Fracture toughness Granite Finite fracture mechanics

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Different culture conditions applied to in vitro shoot multiplication of two Eucalyptus benthamii explant sources

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Journal of Forestry Research 2020年第3期31卷 857-869页

作者： Natalia pimentel Esposito-polesi leandro Silva de Oliveira Francisco Jose Benedini Baccarin Cristina Vieira de Almeida Marcilio de Almeida Biological Science Department "Luiz de Queiroz"Superior College of AgricultureUniversity of Sao Paulo(ESALQ/USP)Padua Dias Avenue11P.O.Box 9PiracicabaSP 13418-900Brazil Institute of Agriculture Sciences Federal University of Minas Gerais(UFMG)Universitaria Avenue1000Montes ClarosMG 39404-547Brazil State University of Goias(UEG) Rua S7Qd.1S SulPalmeiras de GoiasGO 76190-000Brazil In vitro palm Consultoria Estudo e Desenvolvimento Biologico LtdaRua Itajobi421PiracicabaSP 13432-000Brazil

Eucalyptus adult material requires more successive subcultures in the in vitro multiplication phase for increased vigor and cellular activity. This study evaluated the endophytic manifestation and shoot multiplication of one 13-year-old Eucalyptus benthamii clone under different culture conditions and used canopy branches(CB) and trunk base material as explant sources. The culture media were wood plant medium(WpM), Murashige and Skoog medium(MS) and JADS(Correia and co-authors medium).Based on the results of the initial multiplication experiment, further tests examined sucrose concentrations and p H. Morphophysiology, dry mass production, endophyticmanifestation and histochemical were determined. Explant sources responded differently to MS and JADS media, but the WpM medium promoted homogeneous *** responses were similar for both explant sources when sucrose concentrations varied. Shoots died in the absence of sucrose, showed high oxidation at 60 g L-1 and optimal development at 30 g L-1. Endophytes were more evident for shoots from the CB origin. Explant sources responded distinctively to treatment due to physiological and intrinsic genetic factors. Therefore, explant sources, different culture media, sucrose concentration and p H may determine micropropagation success and influence the presence and/or intensity of endophytic manifestation.

关键词： plant tissue culture Explant sources Culture media Sucrose pH

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Synthesis of Antennas for Field and polarization Control

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Journal of Electromagnetic Analysis and Applications 2017年第7期9卷 97-112页

作者： leandro p. S. pereira Marco A. B. Terada Antenna Group Electrical Engineering Department University of Brasilia Brasilia Brazil

This article presents a procedure for electromagnetic field and polarization control with antennas. The concept previously introduced by the authors for spatially distributed three-dimensional electromagnetic polarization (as time varies) is discussed and extended also to include non-ideal antennas and the control of electromagnetic field distributions (at a given instant of time). These polarizations and fields are herein referred to as “3D”, although time is also inherent to them. Even that the main objective is to introduce a mathematically/numerically consistent synthesis technique for controlling the 3D electromagnetic fields and polarizations, an effort is made to present and discuss possible applications, including but not limited to torus-knotted distributions and spatial multiplexing for transmission of information in wireless digital communication systems.

关键词： Antennas Electromagnetic Theory Electric Fields Electromagnetic polarization Three-Dimensional polarization and Orthogonality Spatial Multiplexing Transmission of Information Cellular Communication Systems Torus-Knots

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Driving factors of tree biomass and soil carbon pool in xerophytic forests of northeastern Argentina

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Ecological processes 2023年第1期12卷 916-928页

作者： Silvana María JoséSione Marcelo Germán Wilson Silvia Gabriela Ledesma Emmanuel Adrián Gabioud JoséDaniel Oszust leandro Javier Rosenberger Centro de Investigación Científica y de Transferencia Tecnológica a la produc-ción(CICyTTp-CONICET) España 149(3105)DiamanteEntre RíosArgentina Facultad de Ciencias Agropecuarias(FCA-UNER) Universidad Nacional de Entre RíosRuta 11 Km 10.5(3101)Oro VerdeEntre RíosArgentina Instituto Nacional de Tecnología Agropecuaria(INTA) EEA ParanáRuta 11 Km 12.5(3101)Oro VerdeEntre RíosArgentina

Background The conversion of forests into agricultural lands can be a threat because the forests carbon stored could be a source of emissions. The capacity to improve the predictions on the consequences of land use change depends on the identification of factors that influence carbon pools. We investigated the key driving factors of tree biomass and soil carbon pools in xerophytic forests in northeastern Argentina. Based on analyses of forest structure variables and abiotic factors (topography and soil properties) from 18 mature forests, we evaluated carbon pools using uniand multivariate (redundancy analysis) methods. Results The total carbon pool was estimated at 102.4 ± 24.0 Mg ha−1. Soil organic carbon storage is the single largest carbon pool relative to tree biomass, representing 73.1% of total carbon. Tree canopy cover and basal area were positively correlated with biomass carbon pool (r = 0.77 and r = 0.73, p pectively), proving to be significant drivers of carbon storage in this compartment. Slope, soil clay content and cation-exchange capacity had a better explanation for the variability in soil carbon pools, and all showed significant positive correlations with soil carbon pools (r = 0.64, 0.60 and 0.50;p pectively). The vertisols showed a 27.8% higher soil carbon stock than alfisols. Conclusions The relevance of our study stems from a dearth of information on carbon pools and their drivers in xerophytic forests, and in particular, the importance of this ecosystems’ type for Argentina, because they cover 81.9% of native forest area. Basal area and tree canopy cover exert a strong effect on the carbon pool in tree biomass but not in the soil. The results suggests that there is a potentially major SOC accumulation in forests located in slightly sloping areas and soils with higher topsoil clay content, such as vertisols. This could provide an important reference for implementing forestry carbon sink projects.

关键词： Carbon pool Forest biomass Soil parameters Ecosystem services

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