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The COVID-19 pandemic has brought concerns about the efficacy of respiratory protection equipment, primarily due to their widespread usage during this period. Among the various types of face masks, the N95, PFF3, and PFF2 surgical masks have gained great prominence due to their efficiency, despite the discomfort they may cause. Therefore, thinking of a cost-effective and more comfortable solution, this work aimed to reinforce non-woven face masks with cellulose nanofibrils (CNFs), to improve their filtration efficiency. For this, CNFs were produced using the mechanical processing of sugarcane bagasse (SCB) residues, which underwent plain alkaline pretreatment (CNF-PA) or alkaline pretreatment followed by enzymatic pretreatment (CNF-AE). It was observed that the CNF-AE films developed better characteristics regarding the contact angle, density, porosity, transmittance and transparency as well as vapor permeability compared to the CNF-PA films. The application of CNF on non-woven masks was performed using the spray technique. Bacterial filtration analysis showed filtration efficiency of 99.68% and 99.80% for masks that were coated with CNF-PA and CNF-AE, respectively. Whereas uncoated masks presented a filtration efficiency below 95%, which is the minimum required value. The masks obtained breathability values of 79.75 Pa/cm2 and 106.00 Pa/cm2 for CNF-AE and CNF-PA, respectively, whereas the uncoated masks showed values below 30.00 Pa/cm2. This work shows that the CNF obtained from SCB present good barrier capabilities and should be used for this purpose, especially on protective masks.

ABSTRACT Agroforestry systems (AFSs) integrate, through sustainable practices, agricultural and forest crops for the production of wood and food, providing environmental services, and conserving biodiversity. The freijó (Cordia goeldiana) has potential for cultivation in the Amazon for timber purposes, but data on the characteristics of its wood produced in AFSs are scarce. Our objective was to determine the physical-mechanical properties and suggest technological applications of freijó wood produced in a multi-stratified AFS established in the state of Rondônia, Brazil in 1996. Agricultural and forest species were established in the AFS in double rows with 5.0-m x 2.5-m spacing. Three 19-year-old freijó trees were harvested for chemical, physical (density and dimensional stability), and mechanical (compression, static bending, Janka hardness, and shear strength) characterization of the wood. The wood presented a chemical composition similar to tropical hardwoods, was moderately heavy (582.63 kg m-3), and had high dimensional stability in comparison with other consecrated woods on the market (longitudinal, radial, and tangential retraction = 0.25, 4.27, and 6.83%, respectively). The values determined for parallel (32.32 MPa) and perpendicular compression (8.02 MPa), specific strength (55.32 MPa kg-1 m-3), parallel (2373.33 N) and perpendicular Janka hardness (2326.67 N), strength to static bending (63.5 MPa), and shear (5.94 MPa) were similar to the values observed in other high-density tropical woods grown in either monoculture plantations or natural forests. The wood under study is suitable for manufacture of high-value-added products, such as fine furniture, residential floors, musical instruments and structural pieces.

The species Bixa orellana L. is native to the Amazon and is in high demand due to the pharmacological properties of its fruits. However, research on germination and seedling production is incipient. The objective of this study was to evaluate the germination percentage with and without mechanical scarification of Bixa orellana L. seeds associated with commercial substrate or sand. The experiment was carried out in a completely randomized design, in a 2x2 factorial arrangement, with four treatments and four replications each. The germination rate and number of normal seedlings per treatment were determined. In addition to these parameters, the germination speed index, root and shoot length, and fresh and dry biomass of the seedlings were evaluated. The germination rate and normal and abnormal seedlings were expressed in percentage. In relation to the other parameters, the data were submitted to analysis of variance and the means were compared by the Scott-Knott test (p

In Brazil, the concession of public forests for logging is a government initiative to curb illegal exploration and occupation in order to preserve the national patrimony. However, the knowledge about the impacts promoted in this way of exploration is incipient, considering that field data collection can be lengthy and costly. Therefore, geotechnology is inserted in this context by presenting methods of obtaining information with speed and relative precision. So, the objective of this work was to analyze the vegetation cover variation in a public forest area under different logging intensities in the forest concession regime, applying multispectral images and the normalized difference vegetation index (NDVI). The study site was the Jamari National Forest, where two areas were explored for two consecutive years: the Annual Production Unit 01 (UPA 01) with cutting intensities of 9 m³ ha- ¹ and 10.5 m³ ha- ¹ in 2010 and 2011, respectively, and the Annual Production Unit 02 (UPA 02), with cutting intensities of 24 m³ ha- ¹ and 3 m³ ha- ¹, in 2012 and 2013, respectively. The analyzes were performed before, during and after logging and the results were submitted to the paired t-test (p

Objetivou-se estudar o comportamento dos atributos físicos e dos teores e estoques de carbono do solo em sistema agroflorestal multiestratificado (SAF), comparativamente a diferentes modalidades de uso solo, sendo elas o cultivo de cacaueiro sob manejo agroecológico (CAC), pastagem cultivada (PAS) e floresta nativa (FLN). A área de estudo localiza-se na estação experimental da CEPLAC em Ouro do Preto do Oeste, RO. Nos quatro tratamentos foram instaladas, ao acaso, cinco parcelas de 20 m x 30 m. Nessas parcelas, foram coletadas amostras de solo indeformadas e deformadas nas profundidades de 0 a 20 cm e 20 a 40 cm, para determinação dos atributos fiscos e estoque de carbono no solo. Os valores de densidade do solo no SAF, CAC e PAS apresentaram-se elevados e influenciaram negativamente o espaço poroso do solo. Os estoques de C foram influenciados pelos diferentes agroecossistemas, sendo que na camada de 0 a 20 cm foram de (Mg m-3): 24,79 (SAF); 42,71 (CAC); 41,30 (PAS); 36,07 (FLN), e na camada de 20 a 40 cm foram (Mg m-3): 17,26 (SAF); 31,06 (CAC); 22,31 (PAS); 25,49 (FLN). Todos os sistemas avaliados apresentaram resultados esperados para estoque de C no solo, no entanto, arranjos espaciais que favoreçam o aporte de matéria orgânica poderiam contribuir para a elevação dos estoques de carbono do solo em sistemas agroflorestais.