RESUMO

This work assessed the psychosocial risks of 124 workers from the plywood industry in Ecuador's Amazon region. Two psychosocial risk assessment (PRA) methods were selected due to their widespread use in Ecuadorian organisations: FPSICO from the Spanish National Institute for Occupational Safety and Health and the "Psychosocial Risk Assessment Questionnaire" (PRAQ) from the Ecuadorian Labour Ministry. Therefore, two surveys of 89 and 58 items were applied to evaluate nine scales and eight risk dimensions for FPSICO and PRAQ, respectively. Results show that according to FPSICO, the main psychosocial risks were detected in the scales of working time (WT), variety and content (VC), and workload (WL), with a prevalence of 34.8 % and 41.7 %. For PRAQ, the margin of action and control (D4), load and work rate (D1), and leadership (D3) were the most affected dimensions, with a risk prevalence between 29.1 % and 43.6 %. Although there is a lower risk prevalence in the rest of the scales and dimensions assessed, improvement actions are needed in the short term. Furthermore, the findings suggest an association between gender and risk prevalence, especially in the dimensions of Leadership (D3), Skills development (D2), and Self-perceived health (D8.8), where being a woman increases the likelihood of suffering from these conditions by up to three times. In addition, a brief comparative analysis was conducted, looking for coincidences in the scales that each PRA instrument assesses and the prevalence of the psychosocial risks detected.

RESUMO

Research indicates the use of adsorbent materials to remove pollutants from wastewater and effluents, which can be obtained from renewable materials such as biomass, biopolymers (chitosan) or composites. Thus, the objective of this work was to produce and evaluate activated carbon (AC) and chitosan composite films as adsorbents of neutral red dye. AC films were produced using CO2 and water vapor. The variables of the activation process were time (1 and 2 h) and temperature (600 and 750 °C). Five films were produced, with one pure chitosan (T1) film and four activated carbon with chitosan films (T2, T3, T4 and T5). The T2 film refers to activated carbon produced at 600 °C for 1 h + chitosan, T3 to activated carbon produced at 600 °C for 2 h + chitosan, T4 to activated carbon produced at 750 °C for 1 h + chitosan and T5 to activated carbon produced at 750 °C for 2 h + chitosan. The T5 film increased its adsorption capacity by approximately 87% and its removal efficiency of neutral red dye by 43% compared to T1. The presence of activated carbon in the films provided an increase in the adsorption capacity of the neutral red dye.

RESUMO

The quality of plywood depends on factors such as the forest species and the adhesive used in their production, and understanding the interferences of these factors in the final properties of the plywood is of fundamental importance. The study aimed to develop multilayer plywood with two forest species and two types of adhesive and to evaluate the influences of these factors (forest species and adhesive) on the physical and mechanical properties of the plywood. The panels were produced with wood veneers of parica and pine with two types of adhesives, urea-formaldehyde and phenol-formaldehyde, with a weight of 150 g.m2. Then, each set was pressed for 10 min under a specific pressure of 0.98 MPa at a temperature of 150 °C. Three panels were produced for each type of veneer and adhesive, totaling four treatments. The plywood was evaluated for physical properties (moisture content, bulk density, and water absorption) and mechanical properties (parallel and perpendicular static bending strength and shear strength). The results showed that the forest species had a greater influence on physical and mechanical properties, with the best results being observed for plywood produced with pine and PF adhesive. The specific mass of the panels should be considered as it positively influenced the mechanical properties and negatively impacted water absorption. The PCA was used to reduce the dimensionality of the data from 9 dependent variables to 2 main components, explaining 76.70% of the total variance of the data. The multivariate analyzes of the differentiated independent factors showed that both the species and the adhesive affected as properties of the plywood and both independent variables must be taken into account in the production of the plywood. It is concluded that the porosity and specific mass of the paricá veneers contributed to a greater penetration of the adhesives, resulting in lower physical and mechanical properties than the pine veneers. However, in general, it is concluded that the plywoods produced can be used for internal and external applications. However, it is not indicated for structural purposes as it did not meet the requirements of the NBR 31.000.001/2:2001.

Assuntos

RESUMO

The objective of the present research was to analyze 270; 330; 364 and 390 g.m-² amounts of glue in the production of fenolic plywood, using two forest species; Copaifera duckei and Eperua oleifera, and evaluate the static bending of the panels. The wood came from an area of sustained forest pertaining to the Plywood Industry located in Manicoré, county of Amazonas. The panels were produced with thicknesses of 2.2mm at the Gethal Amazonas S.A in Itacoatiara - AM. Forty panels, 20 per species, were produced an industrial level, using a total of 8 treatments. The experiment was completely randomized with factorial arrangement. The European standard EN 310: 1993 was used. The basic density values were 0.60 (g.cm-²) for Copaifera duckei, and 0.62 (g.cm-²) for Eperua oleifera. In static bending, parallel to the grain, only Copaifera duckei presented a significant difference at 5% in the Dunnette Test for the properties of MOE and MOR. In the perpendicular sense to the grain, Copaifera duckei and Eperua oleifera presented significant differences, for MOE as much as MOR, at 5% of probability.

A presente pesquisa teve como objetivo analisar as seguintes gramaturas de cola: 270; 330; 364 e 390 g.m-² a partir da produção de compensados fenólicos utilizando duas espécies florestais; Copaifera duckei e Eperua oleifera e avaliar a flexão estática dos painéis. A madeira foi proveniente da área de manejo florestal sustentado da Indústria de Madeira Compensada localizada em Manicoré, município do Amazonas. As lâminas foram produzidas na Gethal Amazonas S.A - Indústria de Madeira Compensada em Itacoatiara - AM com espessura de 2,2 mm. Foram produzidas a nível industrial 40 painéis, 20 por espécie no total de 8 tratamentos. O experimento foi completamente casualizado com arranjo fatorial. Foi utilizado a norma Européia EN 310: 1993. Os valores de densidade básica da espécie Copaifera duckei foi de 0,60 (g.cm-²) e 0,62 (g.cm-²) para Eperua oleifera. No ensaio de flexão estática, sentido paralelo à grã, somente a espécie Copaifera duckei apresentou diferença significativa a 5% pelo Teste de Dunnette para as propriedades de MOE e MOR. No sentido perpendicular a grã, as espécies Copaifera duckei e Eperua oleifera tanto o MOE quanto o MOR apresentaram diferenças significativas a 5% de probabilidade.

RESUMO

A presente pesquisa teve como objetivo analisar as seguintes gramaturas de cola: 270; 330; 364 e 390 g.m-² a partir da produção de compensados fenólicos utilizando duas espécies florestais; Copaifera duckei e Eperua oleifera e avaliar a flexão estática dos painéis. A madeira foi proveniente da área de manejo florestal sustentado da Indústria de Madeira Compensada localizada em Manicoré, município do Amazonas. As lâminas foram produzidas na Gethal Amazonas S.A - Indústria de Madeira Compensada em Itacoatiara - AM com espessura de 2,2 mm. Foram produzidas a nível industrial 40 painéis, 20 por espécie no total de 8 tratamentos. O experimento foi completamente casualizado com arranjo fatorial. Foi utilizado a norma Européia EN 310: 1993. Os valores de densidade básica da espécie Copaifera duckei foi de 0,60 (g.cm-²) e 0,62 (g.cm-²) para Eperua oleifera. No ensaio de flexão estática, sentido paralelo à grã, somente a espécie Copaifera duckei apresentou diferença significativa a 5 por cento pelo Teste de Dunnette para as propriedades de MOE e MOR. No sentido perpendicular a grã, as espécies Copaifera duckei e Eperua oleifera tanto o MOE quanto o MOR apresentaram diferenças significativas a 5 por cento de probabilidade.

The objective of the present research was to analyze 270; 330; 364 and 390 g.m-² amounts of glue in the production of fenolic plywood, using two forest species; Copaifera duckei and Eperua oleifera, and evaluate the static bending of the panels. The wood came from an area of sustained forest pertaining to the Plywood Industry located in Manicoré, county of Amazonas. The panels were produced with thicknesses of 2.2mm at the Gethal Amazonas S.A in Itacoatiara - AM. Forty panels, 20 per species, were produced an industrial level, using a total of 8 treatments. The experiment was completely randomized with factorial arrangement. The European standard EN 310: 1993 was used. The basic density values were 0.60 (g.cm-²) for Copaifera duckei, and 0.62 (g.cm-²) for Eperua oleifera. In static bending, parallel to the grain, only Copaifera duckei presented a significant difference at 5 percent in the Dunnette Test for the properties of MOE and MOR. In the perpendicular sense to the grain, Copaifera duckei and Eperua oleifera presented significant differences, for MOE as much as MOR, at 5 percent of probability.

Assuntos