ABSTRACT Non-destructive tests that use the principle of wave propagation have the potential to predict the mechanical properties of wood while still in the field, if the variables of this process are known. This work aimed to estimate the modulus of elasticity to static bending of Eucalyptus sp. wood, using two non-destructive techniques: ultrasound and stress wave. For this, 60 specimens with nominal dimensions of 2.5 x 2.5 x 57.5 cm (tangential x radial x longitudinal) were used, being in equilibrium humidity. The non-destructive tests were carried out using an ultrasound and a stress wave equipment, while the destructive static bending tests were carried out in a universal testing machine. The experimental results showed that the elastic modulus obtained by the non-destructive techniques were superior to that obtained by the destructive technique. The adjusted mathematical models presented standard error of the estimate (Syx) of 11.39 and 10.78%. There was a positive mean correlation between the static and dynamic module. Stress wave and ultrasound techniques can be used to estimate the modulus of elasticity of Eucalyptus sp.

RESUMO Os ensaios não destrutivos que utilizam o princípio de propagação de ondas têm potencial para predizer as propriedades mecânicas da madeira ainda em campo, se conhecida as variáveis deste processo. Este trabalho teve o objetivo de estimar o módulo de elasticidade à flexão estática da madeira de Eucalyptus sp., por meio de duas técnicas não destrutivas: ultrassom e stress wave. Para tal foram usados 60 corpos de provas com dimensões nominais de 2,5 x 2,5 x 57,5 cm (tangencial x radial x longitudinal), estando na umidade de equilíbrio. Os testes não destrutivos foram realizados por meio de um equipamento de ultrassom e um de ondas de tensão, enquanto que os testes destrutivos de flexão estática foram realizados em uma máquina universal de ensaios. Os resultados experimentais mostraram que os módulos de elasticidade obtidos pelas técnicas não destrutivas foram superiores à obtida pela técnica destrutiva. Os modelos matemáticos ajustados apresentaram erro padrão da estimativa (Syx) de 11,39 e 10,78%. Logo, houve correlação média positiva entre o módulo estático e dinâmico. As técnicas de ondas de tensão e ultrassom podem ser empregadas com o intuito de estimar o módulo de elasticidade da madeira de Eucalyptus sp.

ABSTRACT This work aimed to estimate the basic density of Eucalyptus sp. wood, using the non-destructive ultrasound technique. For this, 113 specimens with nominal dimensions of 2.5 x 2.5 x 57.5 cm (tangential x radial x longitudinal) were used, being in equilibrium humidity. To perform the density estimation, the three-dimensional model that governs the propagation of longitudinal waves in isotropic solids was used. The input variables of the model were determined, being the longitudinal modulus of elasticity by static bending, the Poisson's ratio by numerical methods and the propagation velocity of the ultrasound wave by a non-destructive ultrasound testing equipment. The basic density was also obtained by the hydrostatic balance method as a reference value. The actual average basic density was 595.40 kg.m-3 and the estimated one was 591.21 kg.m-3. The estimated value had a strong correlation with the observed value with r =0.89. The estimation by the three-dimensional model showed a low error with an RMSE of 6.50% and a bias of 0.59%. The estimation of the basic density using this method obtained good precision, being similar to the resistography technique.

RESUMO Este trabalho teve o objetivo de estimar a densidade básica da madeira de Eucalyptus sp., por meio da técnica não destrutiva de ultrassom. Para tal foram usados 113 corpos de provas com dimensões nominais de 2,5 x 2,5 x 57,5 cm (tangencial x radial x longitudinal), estando na umidade de equilíbrio. Para realizar a estimação da densidade, foi usado o modelo tridimensional que rege a propagação de ondas longitudinais em sólidos isotrópicos. Foram determinadas as variáveis de entrada do modelo, sendo o módulo de elasticidade longitudinal por flexão estática, o coeficiente de Poisson por métodos numéricos e a velocidade de propagação da onda de ultrassom por um equipamento de ensaios não destrutivos de ultrassom. Também foi obtida a densidade básica pelo método da balança hidrostática como valor de referência. A densidade básica média real foi de 595,40 kg.m-3 e a estimada de 591,21 kg.m-3. O valor estimado teve forte correlação com o valor observado com r = 0,89. A estimação pelo modelo tridimensional apresentou baixo erro com RMSE de 6,50% e viés de 0,59%. A estimação da densidade básica empregando este método obteve boa precisão, sendo semelhante à técnica de resistografia.

ABSTRACT The study analyzed the association between environmental, social and governance (ESG) and the life cycle stages of Brazilian publicly-traded companies listed on the B3 S.A. - Brasil, Bolsa, Balcão (B3) from 2010 to 2020. It explores a theoretical gap regarding the relationship between the life cycle stages of companies and ESG initiatives in Brazil, an emerging country. The findings are relevant for understanding how the life cycle stages act as signals of the level of ESG actions of companies and how the market perceives these actions and their ability to create value. The research provides evidence that the fundamentals of the firm life cycle theory function as indicators for several organizational perspectives, including ESG practices. The sample consisted of 109 companies whose data were collected from Thomson Reuters® and analyzed using multiple regression. The model proposed by Dickinson (2011) was used to analyze the life cycle stages. It should be highlighted that the data were also analyzed using the fixed effect as an estimation of the econometric model, but there was a loss of statistical significance in the relationship found, possibly due to the sample selection performed in the unbalanced panel. Based on the sample analyzed and the econometric models used, the results indicate that companies in the birth and turbulence stages have lower levels of ESG practices, particularly in the environmental and social pillars, compared to companies in the maturity stage. The findings also show that ESG initiatives in the Brazilian capital market are associated with measures of companies’ profitability, liquidity, indebtedness, market value, and number of analysts. The research contributes to the analysis of the relationship between the adoption of ESG practices and the life cycle stages of companies in an emerging market, with implications for stakeholders regarding the targeting of resources to sustainable actions.

RESUMO O estudo analisou a associação entre o environmental, social and governance (ESG) e os estágios de ciclo de vida das empresas brasileiras de capital aberto listadas na B3 S.A. - Brasil, Bolsa, Balcão (B3) no período de 2010 a 2020. Explora-se uma lacuna teórica sobre a relação dos estágios de ciclo de vida das empresas com iniciativas ESG no Brasil, um país emergente. As evidências são relevantes para a compreensão de como os estágios do ciclo de vida funcionam como sinalizadores do nível de ações ESG das companhias e para demonstrar como o mercado percebe essas ações e sua capacidade de geração de valor. A pesquisa traz insights de que os fundamentos da teoria dos estágios de ciclo de vida da firma funcionam como indicadores para diversas perspectivas organizacionais, até mesmo para as práticas ESG. A amostra foi composta por 109 empresas cujos dados foram coletados na Thomson Reuters® e analisados por meio de regressão múltipla. Para análise dos ciclos de vida, utilizou-se o modelo proposto por Dickinson (2011). Cabe destacar que os dados também foram analisados utilizando o efeito fixo como estimação do modelo econométrico, porém houve perda da significância estatística na relação encontrada, possivelmente devido à seleção da amostra realizada no painel desbalanceado. A partir da amostra analisada e dos modelos econométricos utilizados, os resultados indicam que as empresas em estágio de nascimento e turbulência apresentam menores níveis de práticas ESG, notadamente nos pilares ambiental e social, se comparadas às empresas em estágio de maturidade. Os achados também evidenciaram que as iniciativas ESG no mercado de capitais brasileiro estão associadas com medidas de rentabilidade, liquidez, endividamento, valor de mercado e número de analistas das organizações. A pesquisa contribui para a análise da associação entre a adoção de práticas ESG e os estágios de ciclo de vida das empresas em um mercado emergente, com reflexões aos stakeholders a respeito do direcionamento de recursos em ações sustentáveis.

The student who has just entered higher education is faced with chemical knowledge that receives a much deeper treatment when compared to high school so that he is not always able to construct meanings for this knowledge. To help in this construction of meanings, we analyzed an experience in which students of an Inorganic Chemistry course were asked to produce a text based on the reading of a scientific divulgation text and to participate in the evaluation process of their colleagues’ texts. We observed a good involvement with the activity and the construction of relationships between the topic in question and the contents developed in the discipline, what contributed to improve the performance of the class. We argue that the involvement with creative writing of scientific texts should be encouraged throughout the entire undergraduate course.

Abstract Fire risk mapping is a basic planning and protection element. This study presents the application of fuzzy logic in a geographic information system (GIS) as an alternative multi-criteria analysis for determining the areas of highest risk of forest fire in natural forest remnants in the Brazil. In the decision-making process, a set of factors that are relevant to fire safety were identified in the study area. For each input variable chosen for the model, a pertinence function was defined that best described its influence on fire risk. Subsequently, the variables were combined for the presentation of the final fire risk map. Concluded in the study that an increased risk of fire occurs at the wildland - urban interface. A strong relationship was observed between the fire ignition points and proximity to roads and urban areas. The proposed model was efficient to integrate the variables and determine areas of greatest risk.

ABSTRACT The objective of this study was to compare different alternatives to estimate the stem volume of individual trees in four different forest formations in the Minas Gerais state, Brazil. The data were obtained in a forest inventory procedure performed by the Minas Gerais Technological Center Foundation. The stem volumes were computed by the Smalian expression up to the outside bark diameter equal to 4 cm. The volume data of outside bark, diameters (DBH) and total heights were used to fit a Schumacher and Hall equation for each forest formation, considering the structures of the linear fixed and mixed models. Next, 100 Multilayer Perceptron artificial neural networks (ANN) were trained in a supervised manner. In addition, we evaluated eight support-vector machine regression (SVMR). The criteria to evaluate the performance of all the alternatives studied were: the correlation between the observed and estimated volumes, the square root of the mean square error and the frequency distribution by percentage relative error class. After the analyzes, all the alternatives were verified to estimate the volume of the individual trees in the different forest formations. Although the alternatives presented close statistics in the validation process, the graphical analysis of the error distribution showed greater precision of the estimates of the mixed linear models for the four formations. Given the results, it is concluded that there is no absolute superiority of one alternative over the others, and that all of them should be evaluated to find the one which best describes or explains the dataset.

Abstract The objective of this study was to assess and compare two methodologies to predict the mortality of individual trees in a seasonal semi-deciduous forest located in the municipality of Viçosa, Minas Gerais, Brazil. The data came from 10 permanent plots and were randomly divided into two groups: fitting (6 plots) and validation (4 plots). When assessing Methodology 1, the mortality was considered a dichotomous variable in a logistic model, assuming a value of 1 for a dead tree and 0 for a living tree. In Methodology 2, the mortality probability was estimated by the group of trees for each plot and for each measurement interval. After the analysis, it was observed that Methodology 2 provided more consistent mortality estimates when compared to the mortality estimated by Methodology 1.

ABSTRACT This paper aimed to estimate the basic density (DB) of the wood of Cerrado species using mixed linear models. For performing the DBH measurement, the sampling of 334 individuals was carried out. By keeping the Pilodyn apparatus in the DBH position, two measurements were made on opposite sides. Further, for determining DB, the trees were knocked down, followed by removal of five wood discs at different height of stem positions. For this purpose, two sets of modeling alternatives were proposed, which take into account with and without random effects, employing species as a random effect grouping variable. Thus, it was elucidated that, for the estimation of DB, the mixed model that considered the random effects performed better as compared to the alternative model without random effects. The inclusion of random effects leads to the estimation of DB with high accuracy.

Resumo Estudos sobre a estrutura vegetacional de fragmentos florestais que consideram o uso pretérito do solo podem contribuir para subsidiar ações conservacionistas e de restauração florestal. A partir disso, objetivamos comparar três sítios de um fragmento florestal com distintas histórias de perturbação e verificar se os mesmos diferem entre si com relação ao estágio sucessional analisando atributos estruturais da vegetação arbórea e abundância de lianas. A área estudada localiza-se no município de Alegre-ES, em uma Floresta Estacional Semidecidual constituída por três sítios com diferentes históricos de uso do solo e idades de pousio que recuperaram-se de corte seletivo (CS), lavoura de café (CC) e pastagem (PA). Utilizamos parcelas (19) de área fixa (20 × 20 m) na amostragem, totalizando 0,76 ha. Os indivíduos arbóreos com DAP ≥ 5 cm e as lianas com DAP ≥ 1 cm foram amostrados. A análise da categoria sucessional demonstrou que os sítios CS e PA possuem estágio mais avançado de sucessão em relação à CC. A espécie de maior VI, síndromes de dispersão e lianas apontaram maior avanço sucessional do sítio PA, área com maior proteção aos efeitos de borda e antrópicos por estar localizada no interior do fragmento florestal. As demais análises não demonstraram diferença entre os três sítios.

Abstract To consider past land use on vegetative structure studies of forest fragments can contribute to conservation and forest restoration actions. From this we aim to compare three sites of a forest fragment with distinct anthropogenic disturbances and to verify if they differ on successional stage through analyses of structural traits (trees) and non-trees abundance (lianas) The studied area is located in the Alegre municipality, ES state, in a semideciduous seasonal forest matrix with different land use history composed of selective cutting (CS), coffee crop (CC) and pasture (PA). At each site, randomly plots were sample (19 total plots, 20 × 20 m each), totaling 0.76 ha. All tree individuals with DBH ≥ 5 cm and liana with DBH ≥ 1 cm were sampled. The successional category showed an advanced stage of succession in the CS and PA sites. The specie with higher VI, the dispersion syndromes and the abundance of lianas showed successional advanced stage only in the PA site, because is located inside the forest fragment providing greater protection from edge effects, and anthropogenic disturbances. The others analyses didn´t showed statistical differences between the three sites.

ABSTRACT The objective of this study was to evaluate the use of the MSI Sentinel-2 and SRTM data to estimate the volume of wood in a Semidecidual Seasonal Forest. Regression equations were fitted based on the remote sensing data, taking into consideration the individual bands and vegetation index of the MSI, elevation values and their derivatives obtained from the SRTM mission and the combination of the data drawn from the MSI and SRTM. RMSE and graphic analysis of residues were used to assess the accuracy of the fitted equations. The best model revealed values of 0.6508 and RMSE of 20.41% in the fit, and of 0.5680 and RMSE of 26.61% in the validation, using the combined MSI and SRTM data as predictors. The volume estimation using spectral data showed satisfactory results, highlighting the importance of topography in the prediction of the volume of wood for the area under investigation.

ABSTRACT The aim of this study was to evaluate the effects of age, site, and density factors on the dynamics of eucalyptus diameter distribution. Data were obtained from a continuous forest inventory measured at different occasions, stratified according to the factors evaluated and adjusted by the three-parameter Weibull function using nonthinned clonal plots of eucalyptus stands located in the Central region of the state of Minas Gerais. In order to evaluate the diameter distribution behavior, asymmetry and kurtosis measures and graphical analysis for fitted curves were used. In general, an increase was observed in diameter amplitudes with aging, as well as with improvement of site productivity and higher densities. The number of trees decreased in the lower classes and increased in the upper classes, resulting in diameter distribution curves, being displaced to the right and flattened with aging.

RESUMO Objetivou-se verificar o potencial de folhas de girassol mexicano (Tithonia diversifolia) como alternativa de manejo ao nematoide Pratylenchus brachyurus em quiabeiro. Foram conduzidos dois ensaios em casa de vegetação, em delineamento inteiramente casualizado, com sete repetições, sendo cada parcela composta por um vaso contendo uma planta. Utilizou-se o quiabeiro como planta indicadora e o sorgo como testemunha suscetível. Os tratamentos foram cinco níveis de fitomassa verde e seca (0, 5, 10, 15 e 20 g kg-1 de solo) de T. diversifolia, incorporada ou na forma de cobertura do solo, para avaliar o efeito sobre a população de P. brachyurus. A incorporação de folhas frescas de T. diversifolia no solo, como adubo verde, reduziu a população de P. brachyurus 60 dias após a inoculação, com destaque para o nível de 20 g kg-1 de solo que possibilitou reduzir a população do nematoide (FR=0,00). Com 5 g de fitomassa seca, em cobertura, de T. diversifolia foi possível reduzir 2,96 % a população do nematoide, enquanto que os níveis de fitomassa seca de 10, 15 e 20 g kg-1 de solo eliminou o patógeno. Conclui-se que a incorporação ao solo de folhas frescas de T. diversifolia, e a cobertura morta com folhas de T. diversifolia sobre o solo, na forma de fitomassa seca, proporcionaram redução na população de P. brachyurus no solo e nas raízes de quiabeiro, sendo uma alternativa importante para o manejo de P. brachyurus

ABSTRACT The objective of this study was to verify the potential of Mexican sunflower leaves (Tithonia diversifolia) as an alternative for the management of the nematode Pratylenchus brachyurus in okra. Two trials were conducted in a greenhouse, in a completely randomized design, with seven replicates, and each plot consisting of one pot containing one plant. Okra was used as an indicator plant and sorghum as a susceptible control. Treatments were five levels of green and dry phytomass (0, 5, 10, 15 and 20 g kg-1 soil) of T. diversifolia, incorporated in the soil or as soil cover, to evaluate their effect on P. brachyurus population. The incorporation of fresh leaves of T. diversifolia in the soil as green manure reduced P. brachyurus population 60 days after inoculation, especially the level of 20 g kg-1 soil, which allowed complete reduction in the nematode population (FR = 0.00). At 5 g dry phytomass of T. diversifolia, as soil cover, nematode population could be reduced by 2.96%, while the dry phytomass levels of 10, 15 and 20 g kg-1 soil eliminated the pathogen. In conclusion, the incorporation of fresh leaves of T. diversifolia in the soil and mulching with T. diversifolia leaves on the soil, in the form of dry phytomass, provided a reduction in the population of P. brachyurus in the soil and in the roots of okra, constituting an important alternative for the management of P. brachyurus.

ABSTRACT This research was conducted in wood harvesting and transportation areas in the mountainous region of Espírito Santo, Brazil, aiming to analyze the road transportation of forestry wood operations with self-loading trucks. The study identified and evaluated the times, average speed, mechanical availability, level of use and operating efficiency of three different designs of self-loading trucks. According to the results, there was no statistical difference between the vehicles regarding average speed. The highest mechanical availability was found in truck A (93.2%), followed by B (84.3%) and C (79.8%). The greater degree of utilization was found in truck B (91.8%), with little variation between vehicles C (90.0%) and A (89.9%). The highest operating efficiency was observed in truck A (83.9%), followed by B (77.4%) and C (71.8%). We concluded that self-loading truck A was the most efficient.

ABSTRACT: The main purpose of this study was to assess nonlinear models generated by integrating the basal area growth rate to estimate the growth and yield of forest stands. The database was collected from permanent sample units, in Paraopeba county, in the state of Minas Gerais, Brazil. The stands were represented by Eucalyptus camaldulensis × Eucalyptus urophylla hybrid trees, with 3 × 3 meters of spacing. The data were divided into two groups: fitting and validating databases. Two nonlinear models (Strategy A and Strategy B) were developed using differential equations to estimate the basal area growth and yield of the sample units. The logistic model was fitted to estimate the volumetric yield as a function of age, site index and basal area. The efficiency of the systems generated by logistic model and models obtained by differential equations (Strategy A and Strategy B) was also compared to the efficiency of the system estimated by the Clutter model (Strategy C). The projection models used to estimate basal area obtained by differential equations were compatible with forest growth and yield, and the logistic model with covariates was compatible with volumetric growth and yield. Strategy A and Strategy B generated different thinning and harvesting options for different site indices, which is biologically consistent.

RESUMO O cultivo intensivo de hortaliças com frequentes fertilizações químicas pode ocasionar acúmulo de nutrientes no solo que, por sua vez, pode reduzir a produtividade das culturas, além de prejudicar o ambiente através de contaminação de lençóis freáticos, mananciais e rios. Assim, com objetivo de avaliar o efeito de doses de P (0, 100, 200, 300 e 400 kg ha-1 de P2O5) e K (0, 60, 120, 180 e 240 kg ha-1 de K2O) no crescimento e produtividade de cultivares de rabanete (Sakata 19 e Sakata 25), em solo com altos teores desses nutrientes, foram realizados dois experimentos, em delineamento de blocos ao acaso, com os fatores cultivares e doses arranjados em esquema fatorial 2 x 5, com três repetições. Foram avaliados o número de folhas por planta, área foliar, massa seca da parte aérea e da raiz, produtividade total e comercial, porcentagem de raízes rachadas e os teores de P e K na planta e no solo. A cultivar ‘Sakata 19’ apresentou melhor desempenho que a ‘Sakata 25’ nos dois experimentos. A fertilização com P ou K não influenciou o crescimento e a produtividade das cultivares de rabanete. Portanto, culturas de rabanete, com ambas cultivares avaliadas, não precisam ser fertilizadas com P e K quando implantadas em Latossolo com altos teores desses nutrientes.

ABSTRACT The intensive cultivation of vegetables with frequent chemical fertilization may cause accumulation of nutrients in the soil. This, in turn, may reduce crop yields and damage the environment due to contamination of ground water and rivers. Thus, to increase the effects of P (0, 100, 200, 300 and 400 kg ha -1 of P2O5) and K (0, 60, 120, 180 and 240 kg ha-1 of K2O) doses on the growth and productivity of radish cultivars (Sakata 19 and Sakata 25) in a soil with high levels of these nutrients, two experiments were conducted in randomized blocks with the factors cultivars and doses arranged in a 2 x 5 factorial design with three replications. Number of leaves per plant, leaf area, shoot and root dry mass, total and commercial productivity, percentage of cracked roots and P and K contents in the plant and in the soil were evaluated. The Sakata 19 cultivar performed better than the Sakata 25 in both experiments. The fertilization with P or K did not influence the growth and the productivity of both radish cultivars. Therefore, both cultivars of radish evaluated do not need to be fertilized with P and K when planted in a Latosol with high levels of these nutrients.