Effects of a 16-week training program with a pyramidal intensity distribution on recreational male cyclists

Different training intensity distributions (TIDs) have been proposed to improve cycling performance, especially for high-competition athletes. The objectives of this study were to analyze the effect of a 16-week pyramidal training intensity distribution on somatic and power variables in recreational cyclists and to explore the training zone with the greatest impact on performance improvement. The sample consisted of 14 male recreational cyclists aged 41.00 ± 7.29 years of age. A number of somatic variables were measured. During an incremental protocol, power at a 4 mMol·L−1 blood lactate concentration (P4), corresponding power to body mass ratio (P/W P4), and heart rate (HR P4) were also measured. Among the somatic variables, the percentage of fat mass showed the greatest improvement between moments (p < 0.001, d = 0.52). Both P4 (p < 0.001, d = 1.21) and P/W P4 (p < 0.001, d = 1.54) presented a significant increase between moments. The relative improvement in P4 (% P4) showed a significant correlation (Rs = 0.661, p = 0.038) and relationship (R2 = 0.61, p = 0.008) mainly with training zone Z2 (blood lactate levels ≥ 2 and <4 mMol·L−1). It seems that spending more time in Z2 promoted an improvement in both somatic and power variables in recreational cyclists.This research was funded by FCT—Portuguese Foundation for Science and Technology, grant number UIDB/DTP/04045/2020.info:eu-repo/semantics/publishedVersio

INFLUENCE OF LOG LENGTH ON THE PRODUCTIVITY OF WOOD HARVESTING AND TRANSPORTATION

The selection of machines and the development of operating systems are the major challenge for reducing costs in harvesting and forest transportation. This work aimed to carry out a technical analysis of harvesting and forest transport activities in two different log lengths (6 and 7m). The operational cycles of the Harvester, Forwarder and combined road train vehicle in mechanized harvest areas were evaluated. The technical analysis was performed through studies of times and movements, determining the operational efficiency and productivity of the machines. According to the results, processing consumed most of the harvester's operational cycle, while in the forwarder, the most time was consumed  35,2 and 45,2 m³·he-1 and 42,84 and 75,42 m³.he-¹. The larger log size led to an increase in the productivity of the harvester by 28% and the forwarder by 48%. Among the studied models of road train vehicles, the one that showed the best results both in the analysis made with a length of 6 m and 7 m, was the dimensions with 2.35 m in width and 2.85 in height. These vehicles had a total gross weight of 63.52 tonnes for logs with a length of 6m and 69.17 tons for logs of 7m, with an 8.17% higher performance compared to 6m logs. With the obtained results it can be concluded that the increase in the length of the logs increased the productivity and the performance of the harvest and the forest transport

EXPOSURE OF OPERATORS TO CHAINSAW VIBRATION IN FOREST HARVESTING

The implementation process of mechanized systems which occurred in the last decades in Brazil has brought numerous benefits of profitability, quality and safety for forestry activities. However, mechanization can cause harmful effects to the health of operators, among which include the excess of vibration that is responsible for numerous disorders such as Raynaud’s syndrome. The objective of this study was to evaluate the degree of exposure to vibration of chainsaw operators in cutting eucalyptus trees on farms. Thus, a portable accelerometer with a triaxial attachment positioned at the fingers of the operators was used to measure the data. The methodology proposed by NHO-10 was used to classify the degree of exposure. According to the results, 55% of the operators presented above the acceptable levels of exposure, requiring interventions which enable reduced hand-arm vibration. The vibration effects were observed to be more severe in the left hand socket of the operators. Based on the obtained results, it is concluded that there is a need for preventive and corrective measures which reduce the exposure of the operators as an intervention in the design of the machines, more rotation between operations, and greater care with the maintenance of the machines, training and reduced exposure time

Analysis of vibration in secondary wood processing with different apparent specific masses

 O objetivo desta pesquisa foi identificar os níveis de vibração ocorridos no processamento secundário da madeira e quantificar sua interação com a diferença de massa específica aparente entre as espécies de madeira. A pesquisa foi desenvolvida na marcenaria do Departamento de Ciências Florestais e da Madeira, do Centro de Ciências Agrárias da Universidade Federal do Espírito Santo, localizada no município de Jerônimo Monteiro, sul do Espírito Santo, no período de agosto a dezembro de 2010. As vibrações transmitidas ao sistema mão-braço dos trabalhadores pelas máquinas foram coletadas por intermédio de um acelerômetro e de um medidor de vibração. As espécies utilizadas na pesquisa foram Apuleia leiocarpa, Eucalyptus grandis versus E. urophylla (híbrido urograndis), Corymbia citriodora e Pterogyne nitens. Todas as máquinas apresentaram classificação de conforto para o eixo XY (palma da mão e nós dos dedos) e classificação de fadiga para o eixo Z (punhos). A serra fita foi a única máquina que não apresentou variação da vibração em relação à espécie processada. Conforme a classificação de fadiga para o eixo Z, é necessária a execução de medidas para o controle da vibração.Palavras-chave: Ergonomia florestal; ambiente de trabalho; densidade da madeira; marcenaria.AbstractAnalysis of vibration in secondary wood processing with different apparent specific masses. The aim was to identify the levels of vibration that occurred in the secondary wood processing, and to quantify vibration interaction with the difference of apparent specific mass. The research was developed in wood workshops of Department of Forestry, Center for Agrarian Sciences, Federal University of Espirito Santo, located in Jerônimo Monteiro city, south of Espírito Santo, from August to December 2010. The vibrations transmitted to the hand-arm system of the workers by the machines had been collected by an accelerometer 20 model NK and a measurer of vibration model NK 300. The species used in the research had been Apuleia leiocarpa, Eucalyptus grandis versus E. urophylla (hybrid urograndis), citriodora Corymbia and Pterogyne nitens. All the machines had presented classification of comfort for axle XY and classification of fatigue for axle Z. As result, according to the classification of fatigue for axle Z, measures are necessary for the control of the vibration.Keywords: Forest ergonomics; work environment; density of the wood, joinery.  AbstractThe aim was to identify the levels of vibration that occurred in the secondary wood processing, and to quantify vibration interaction with the difference of apparent specific mass. The research was developed in wood workshops of Department of Forestry, Center for Agrarian Sciences, Federal University of Espirito Santo, located in Jerônimo Monteiro city, south of Espírito Santo, from August to December 2010. The vibrations transmitted to the hand-arm system of the workers by the machines had been collected by an accelerometer 20 model NK and a measurer of vibration model NK 300. The species used in the research had been Apuleia leiocarpa, Eucalyptus grandis versus E. urophylla (hybrid urograndis), citriodora Corymbia and Pterogyne nitens. All the machines had presented classification of comfort for axle XY and classification of fatigue for axle Z. As result, according to the classification of fatigue for axle Z, measures are necessary for the control of the vibration.Keywords: Forest ergonomics; work environment; density of the wood, joinery. 

AVALIAÇÃO DA ILUMINÂNCIA NA IMPLANTAÇÃO E MANUTENÇÃO FLORESTAL NAS MICRORREGIÕES CAPARAÓ E CENTRO SUL DO ESPÍRITO SANTO

Como importante segmento, o setor florestal depende diretamente de mão de obra para execução das atividades, sendo que, esse fator necessita de atenção no âmbito de melhores condições de trabalho. Este estudo teve o objetivo de avaliar a iluminância durante a execução de atividades florestais realizadas nas microrregiões Caparaó e centro sul do estado do Espírito Santo. A pesquisa foi realizada em áreas florestais de produção de eucalipto, nos municípios de Alegre, Jerônimo Monteiro e Guaçuí, no período de outubro de 2012 a maio de 2013. Inicialmente foram levantadas as atividades do ciclo de trabalho e determinou-se o número mínimo de amostras necessárias em cada fase da pesquisa. Foram avaliadas as atividades de adubação, capina química, coroamento, coveamento, desrama manual, desrama semi-mecanizada e roçada semi-mecanizada, e os resultados a legislação. Observou-se que em todas as atividades os níveis de iluminância foram aceitáveis, sendo superior ao mínimo de acordo com a NBR 5413 (1992). Mas há necessidade de proteção especial para a visão, principalmente nos horários de maior irradiação solar

AVALIAÇÃO DE CUSTOS DE DOIS MODELOS DE HARVESTER NO CORTE DE EUCALIPTO

http://dx.doi.org/10.5902/1980509815733The present study aimed to carry through the evaluation of costs of two models of harvester in the wood harvesting of Eucalyptus wood. The research evaluated the 6-year old tree fallen and processing, in the cut-to-length system for two models of harvester, in areas located in the cities of Conceição da Barra, Espírito Santo state and Caravelas, Bahia state. It was evaluated the models of harvester PC-228 SHO and PC-200 LC, of the Komatsu Mark. The information was collected during a period of 6 months, from March to August 2010, by the method of census. It was calculated the operational costs of the two models of harvester, for the countable method, which uses values in ‘Reais’, the Brazilian currency. It was conducted further analysis of cost sensitivity for the elements that contribute most to the final cost. We obtained the operating cost models for PC 200 and PC 228 of R$156,95 and R$ 168,84 per effective hour, respectively. In relation with the total operational costs, the most significant costs were: fuel, maintenance, and repairs/ depreciation, with 24.41%, 22.39% and 19.08%, respectively. In the sensitivity analysis, simulating a situation where the company gets a real economy of 10% in each one of these items, the same one will be able to get a reduction in the cost of production in 7%, for the two evaluated machines.http://dx.doi.org/10.5902/1980509815733O presente estudo teve o objetivo de realizar a avaliação de custos de dois modelos de harvester, na colheita de madeira de eucalipto. A pesquisa avaliou a derrubada e o processamento da árvore, com idade de 6 anos, no sistema de toras curtas, para dois modelos de harvester, em áreas localizadas nos municípios de Conceição da Barra – ES e Caravelas – BA. Avaliaram-se dois modelos de harvester, PC-228 SHO e PC-200 LC, da marca Komatsu. As informações foram coletadas durante um período de 6 meses, que compreende os meses de março a agosto de 2010, pelo método de censo. Calcularam-se os custos operacionais dos dois modelos de harvester, pelo método contábil, o qual utiliza valores estimados em reais. Realizou-se ainda a análise de sensibilidade de custos para os elementos que mais contribuem com o custo final. Obteve-se o custo operacional para os modelos PC 200 e PC 228 de R$156,95 e R$ 168,84 por hora efetiva, respectivamente. Em relação aos custos operacionais totais, os custos mais significativos foram: combustível, manutenção e reparos e depreciação, com 24,41%, 22,39% e 19,08%, respectivamente. Na análise de sensibilidade, simulando uma situação em que a empresa consiga uma economia real de 10% em cada um desses itens, a mesma poderá obter uma redução no custo de produção em 7%, para as duas máquinas avaliadas