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1.
Bioresour Technol ; 316: 123884, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32889386

RESUMO

Timber industry generates large amounts of residues such as sawdust. Softwoods have a significant economic value for timber production and the Pinus genus is widely utilized. Thus, the aim of this work was to study the hemicellulose extraction and lignin recovery from pine (Pinus spp.) residual sawdust (PRS) by sequential acid-alkaline treatment, generating a cellulose-rich solid fraction. The hemicellulose removed was 87.11% (wt·wt-1) after dilute acid treatment at 130 °C, 4.5% (wt·wt-1) of H2SO4 for 20 min at 120 rpm. Three temperatures were evaluated for recovering the lignin and the highest yield, 93.97% (wt·wt-1), was achieved at 170 °C, 10% (wt·wt-1) of NaOH for 90 min at 120 rpm. Lignin was characterized by Fourier-transform infrared spectroscopy, nuclear magnetic resonance and thermogravimetry. The resulting cellulose-rich fraction exhibited polymorphic transformation. The results demonstrated that PRS is a promising lignocellulosic residue whose lignin and carbohydrates can be readily obtained.


Assuntos
Lignina , Pinus , Celulose , Hidrólise , Termogravimetria , Madeira
2.
Sci Total Environ ; 738: 140357, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32806374

RESUMO

The wood panel industry requires the introduction of more environmental-friendly adhesives due to the strict current regulations on formaldehyde-based emissions. The purpose of this study was to environmentally analyse the production of four different bio-adhesives as alternatives to the most conventional fossil resins used in the production of wood panels. The bio-adhesives proposed for analysis derived from different available renewable biopolymers such as protein (soy) and lignin (Kraft and Organosolv), as well as tannin. The production systems were evaluated from a cradle-to-gate perspective using the Life Cycle Assessment methodology, with the aim of identifying critical parameters and comparing them with fossil substitutes. Inventory data of bio-adhesives were modelled at large scale from lab scale experiments and completed with literature reports. Our results showed that the soy-based and tannin based bio-adhesive had an overall better profile than fossil resins, identifying the production of polyacrylamide for the former, and the production of condensed tannin and glyoxal for the latter, as the main environmental hotspots. In contrast, further research is required on the use of lignins, specifically because of the electricity requirements in the lignin glyoxalation stage (a process required for the functionalization of lignin). Sensitivity analyses were conduced on these key parameters suggesting that there is room for improvement.This study provides useful information for researchers and policy-makers on where to focus their activities with the aim of making the future of bio-adhesives more technically and environmentally favourable.


Assuntos
Adesivos , Madeira , Formaldeído , Indústrias , Lignina
3.
J Environ Radioact ; 222: 106383, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32861137

RESUMO

The determination procedure of low 137Cs concentrations in air using γ-spectrometry is essential wherever the net counts are smaller than the background of the spectrum. Such measurements have performed in April 2020 during the Chernobyl wildfires period. A significant event recorded in Thessaloniki's atmosphere during April 12, 2020, with 25.7 ± 0.7 µBq m-3 of 137Cs, was measured. Besides, a minor incident with a lower 137Cs concentration of 9.6 ± 0.8 µBq m-3 has occurred on April 21, 2020. The above results resemble to a previous one noticed during winter 2013, when signals up to 12.1 ± 0.8 µBq m-3 of 137Cs detected in the atmosphere, due to extensive use of 137Cs contaminated wood for residential heating. The results obtained demonstrate that no radiation hazard rose for the general public due to inhalation of the 137Cs in the air of Thessaloniki, Greece. Moreover, the residence time of the aerosol-bound 137Cs has estimated. The data presented are useful for basic simulation-inputs and comparison with global atmospheric models, which also discussed after comparison with the back trajectories predicted by the NOAA-HYSPLIT model.


Assuntos
Poluentes Radioativos do Ar , Radioisótopos de Césio , Acidente Nuclear de Chernobyl , Monitoramento de Radiação , Madeira , Poluentes Radioativos do Ar/análise , Atmosfera , Radioisótopos de Césio/análise , Florestas , Grécia , Madeira/química
4.
J Environ Manage ; 271: 110926, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778263

RESUMO

In the sustainable management of Amazonian forests, it is essential to carry out the optimal planning of logging infrastructures to reduce costs and environmental impacts. However, there is a high degree of complexity due to the number of variables involved. Among these infrastructures, wood storage yards are of utmost importance as they directly influence the opening of forest roads and trails. The objective of this research was to evaluate the allocation of wood storage yards through exact solution and metaheuristics in a forest management area. The study area was a native forest under sustainable forest management regime located in the Brazilian Amazon. Three instances were formulated involving 5947 trees and 3172 wood storage yards facilities. We used a binary integer programming model solved by CPLEX and the metaheuristics Greedy Randomized Adaptive Search Procedure (GRASP), Tabu Search (TS), Variable Neighborhood Search (VNS) and Simulated Annealing (SA). GAP values increased as a function of instances. Although all metaheuristics obtained significant solutions with shorter processing times, only SA obtained feasible solutions in all executions for all three instances. In general, the metaheuristics were efficient in obtaining feasible solutions faster than CPLEX, which represents the feasibility of the planning of allocation storage large areas, and without significant losses of best-known solution. The SA presented the best performance in the three evaluated instances. Contribution of this study can be highlighted: evaluation of alternative computational methods for planning the allocation of wooden storage yards; evidence was obtained of effectiveness and efficiency of assessed metaheuristics and, the applicability of approximate methods in this problem was evaluated.


Assuntos
Conservação dos Recursos Naturais , Florestas , Brasil , Árvores , Madeira
5.
Waste Manag ; 114: 196-201, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32679477

RESUMO

Forest harvest waste is an attractive biomass feedstock for biofuel production. However, for better use it is necessary to understand the physical-energetic characteristics of the biomass which composes the waste. Therefore, this study aimed to evaluate the bark, wood and tree top characteristics from Eucalyptus urophylla × Eucalyptus grandis (called urograndis) and Acacia mangium harvest wastes. These species present fast-growing characteristics. The evaluations were carried out with waste generated in the forest harvest in central Brazilian plantations. Three fractions were studied: the Top, Wood and Bark. The energetic and physical characteristics of wastes and briquettes were determined. The top and bark of these species are not yet recognized for their energy potential. A. mangium presented better energetic and physical characteristics than urograndis, with a higher mean of fixed carbon (20.84%), a high heating value (20.34 MJ kg-1), as well as high bulk and energy density (272.66 kg m-3 and 5599.00 MJ m-3). A. mangium bark and urograndis tree tops were the fractions with the best characteristics for energy purposes. Bark, wood and tree top waste generated after urograndis and A. mangium forest harvesting can be used as byproducts for energy purposes in their fresh form (as collected in field) or as briquettes, presenting an alternative for the waste.


Assuntos
Eucalyptus , Florestas , Brasil , Árvores , Madeira
6.
J Environ Manage ; 270: 110824, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721299

RESUMO

Lignocellulosic biomass has been widely introduced into the liquefaction process of sewage sludge (SS) to improve the yield/quality of liquefaction products (bio-oil/biochar). This study explores the effect of adding rice straw (RS) and wood sawdust (WS) on the transport/conversion behaviors of heavy metals (HMs) during the liquefaction of SS. The introduction of lignocellulosic biomass, especially for RS, substantially lowers the total content of HMs in biochar. Most HMs (except Cd) still remain in biochar, although the introduction of RS/WS enhances the transport of HMs into bio-oils. The addition of RS/WS raises the percentage of HMs in active form, but the contents of bioavailable/leachable HMs are not considerably increased and even decreased in some cases, especially when RS is introduced. The overall pollution degree and environmental risk of HMs in biochars are lowered to a certain extent with the addition of RS/WS. Considering that the pollution degree and environmental risk of HMs present in biochars are still at a considerable level, appropriate pollution management measures should be undertaken when using such biochars for agricultural use.


Assuntos
Metais Pesados , Oryza , Biomassa , Carvão Vegetal , Esgotos , Madeira
7.
PLoS One ; 15(7): e0235733, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673330

RESUMO

Understanding the determinants of range location and size is fundamental to our understanding of spatial patterns in species richness. Here, we aimed to test the role of 'climatic stability' in determining latitudinal trends in range size and as a consequence on species richness of tropical woody plants. Using primary data from 156 (0.06 ha) plots comprising 20,400 occurrences of more than 400 species of tropical woody plants, we built a biome-wide species database that covers the entire latitudinal extent of the wet-evergreen forests of the Western Ghats (8o to 20o N), India. We consolidated this database using secondary data from other published species inventories. We then calculated the range sizes and climatic niche width of woody plants to test the predictions of the climatic stability hypothesis and examined the relationship between range position and climatic tolerance of species. Our results show a significant latitudinal gradient in species richness and turnover where local and regional species richness increase monotonically from higher latitudes to lower latitudes of the Western Ghats. We found strong support for Rapoport's Rule with an increase in range size from lower to higher latitudes; our results are consistent with the predictions of the climatic stability hypothesis, where species at higher latitudes exhibited greater tolerance to temperature and rainfall seasonality. Contrary to earlier work, our findings suggest that Rapoport's Rule and the climatic stability hypothesis can operate over regional scales, and even at lower latitudes. We suggest that latitude associated climatic seasonality through its influence on species ranges, can influence latitudinal patterns in species turnover as well as species richness.


Assuntos
Adaptação Fisiológica , Mudança Climática , Ecossistema , Modelos Biológicos , Plantas/química , Madeira/fisiologia , Geografia , Índia , Especificidade da Espécie
8.
J Agric Saf Health ; 26(2): 77-92, 2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-32727167

RESUMO

Forestry activities, such as tree cutting and harvesting of forest resources, have been documented as dangerous tasks with increased risk of injuries and fatalities. These hazards are well known in the professional logging community, but less attention is given to farmers who perform occasional tree trimming and cutting activities, especially for the older farmer population. This study examined Indiana farm work-related fatalities from 1988 to 2017 involving farmers 55 years and older who performed occasional wood cutting activities. Fatality cases were mined from the Purdue University Agricultural Safety and Health Program's fatality database. A total of 40 fatality cases were reported, representing 10.3% of all reported farm fatalities of farmers 55 years and older over the time period. The average age of the victims was 67.4, with 65% of cases involving victims 65 years or older. All victims were males. Wood cutting fatalities increased over the observation period. The most frequently reported fatal injury type was being crushed by tree or tree limbs, with 16 cases (40%), and the most common cause of fatality was due to cutting and trimming of trees, with 27 cases (67.5%). It was determined that the incidents were largely preventable and that future injury prevention strategies should address the risks associated with aging, the added risk of being struck by limbs or trees due to unsafe felling practices, the need for appropriate personal protective equipment, and the hazards involved in operating agricultural tractors in wooded areas.


Assuntos
Acidentes de Trabalho/mortalidade , Ferimentos e Lesões/mortalidade , Idoso , Agricultura , Fazendas , Humanos , Indiana , Masculino , Madeira
9.
An Acad Bras Cienc ; 92(suppl 1): e20180797, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32609274

RESUMO

The REML/BLUP procedure has been successfully used for genetic progress through individual selection of high-yielding passion fruit genotypes resistant to the Cowpea aphid-borne mosaic virus. This study was thus developed to estimate genetic parameters and predict the gain obtained from individual selection of genotypes in a population derived from backcrosses in passion fruit. The experiment was set up as a randomized block design with four replicates, involving five full-sib families (genotypes from the first backcross). Variance components and the genetic values were estimated for eight agronomic traits via the REML/BLUP procedure. For all traits, genotypic variance between the genotypes from the first backcross showed little contribution to the phenotypic variance. The low heritability estimates obtained for the traits are overcome via individual BLUP estimates. Therefore, it was possible to obtain considerable gains with individual selection for the variables fruit length, average fruit weight, and pulp weight (19.50 to 14.04%; 22.93 to 17.97%; and 10.08 to 7.95%, respectively). For the traits showing lower gains, it is possible to obtain gains indirectly by selecting genotypes for correlated traits. Because this population derives from the first backcross generation, agronomic traits still must be recovered.


Assuntos
Passiflora , Frutas , Genótipo , Fenótipo , Madeira
10.
Proc Natl Acad Sci U S A ; 117(29): 16776-16781, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32636260

RESUMO

A particularly promising approach to deconstructing and fractionating lignocellulosic biomass to produce green renewable fuels and high-value chemicals pretreats the biomass with organic solvents in aqueous solution. Here, neutron scattering and molecular-dynamics simulations reveal the temperature-dependent morphological changes in poplar wood biomass during tetrahydrofuran (THF):water pretreatment and provide a mechanism by which the solvent components drive efficient biomass breakdown. Whereas lignin dissociates over a wide temperature range (>25 °C) cellulose disruption occurs only above 150 °C. Neutron scattering with contrast variation provides direct evidence for the formation of THF-rich nanoclusters (Rg ∼ 0.5 nm) on the nonpolar cellulose surfaces and on hydrophobic lignin, and equivalent water-rich nanoclusters on polar cellulose surfaces. The disassembly of the amphiphilic biomass is thus enabled through the local demixing of highly functional cosolvents, THF and water, which preferentially solvate specific biomass surfaces so as to match the local solute polarity. A multiscale description of the efficiency of THF:water pretreatment is provided: matching polarity at the atomic scale prevents lignin aggregation and disrupts cellulose, leading to improvements in deconstruction at the macroscopic scale.


Assuntos
Biotecnologia/métodos , Lignina/química , Madeira/química , Proteínas de Bactérias/metabolismo , Biomassa , Celulase/metabolismo , Furanos/química , Gluconacetobacter xylinus/enzimologia , Hidrólise , Lignina/metabolismo , Populus/química , Solventes/química , Tensoativos/química
11.
Ecotoxicol Environ Saf ; 203: 110997, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32684518

RESUMO

A novel study on biodegradation of 30 mg L-1 of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) mixture (celecoxib, diclofenac and ibuprofen) by two wood-rot fungi; Ganoderma applanatum (GA) and Laetiporus sulphureus (LS) was investigated for 72 h. The removal efficiency of celecoxib, diclofenac and ibuprofen were 98, 96 and 95% by the fungal consortium (GA + LS). Although, both GA and LS exhibited low removal efficiency (61 and 73% respectively) on NSAIDs. However, 99.5% degradation of the drug mixture (NSAIDs) was achieved on the addition of the fungal consortium (GA + LS) to the experimental set-up. Overall, LS exhibited higher degradation efficiency; 92, 87, 79% on celecoxib, diclofenac and ibuprofen than GA with 89, 80 and 66% respectively. Enzyme analyses revealed significant induction of 201, 180 and 135% in laccase (Lac), lignin peroxidase (LiP) and manganese peroxidase (MnP) by the fungal consortium during degradation of the NSAIDs respectively. The experimental data showed the best goodness of fit when subjected to Langmuir (R2 = 0.980) and Temkin (R2 = 0.979) isotherm models which suggests monolayer and heterogeneous nature exhibited by the mycelia during interactions with NSAIDs. The degradation mechanism followed pseudo-second-order kinetic model (R2 = 0.987) indicating the strong influence of fungal biomass in the degradation of NSAIDs. Furthermore, Gas Chromatography-Mass Spectrometry (GCMS) and High-Performance Liquid Chromatography (HPLC) analyses confirmed the degraded metabolic states of the NSAIDs after treatment with GA, LS and consortium (GA + LS). Hence, the complete removal of NSAIDs is best achieved in an economical and eco-friendly way with the use of fungi consortium.


Assuntos
Anti-Inflamatórios não Esteroides/análise , Poluentes Ambientais/análise , Ganoderma/enzimologia , Ganoderma/crescimento & desenvolvimento , Lignina/metabolismo , Madeira/microbiologia , Anti-Inflamatórios não Esteroides/metabolismo , Biodegradação Ambiental , Biomassa , Poluentes Ambientais/metabolismo , Indução Enzimática/efeitos dos fármacos , Cinética , Lacase/biossíntese , Modelos Biológicos , Peroxidases/biossíntese
13.
Bioresour Technol ; 314: 123722, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32622277

RESUMO

In this work, valorization of Paulownia wood (PW) was proposed following several process configurations for biofuels and value-added compounds production. Firstly, autohydrolysis and ethanol-organosolv strategies were assessed separately for the fractionation of PW to enhance the enzymatic digestibility of cellulose. A third strategy focused on a sequential process (autohydrolysis and organosolv) was explored. Two temperatures were selected for the first stage of the combined process. High concentration of oligosaccharides (26.29 g/L) and high concentration of degradation products (17.21 g/L) were obtained at 210 and 230 °C, respectively. The solids obtained from both pretreatments were subjected to organosolv delignification (200 °C, 3 h and 50% ethanol) achieving delignification of 58 and 30% for the autohydrolyzed biomass at 210 °C and 230 °C, respectively. The combined process resulted in susceptible biomass able to produce 64 g/L of ethanol. Therefore, the strategies explored in this work open the possibility to build a refinery around Paulownia wood.


Assuntos
Lignina , Madeira , Celulose , Etanol , Hidrólise
14.
Bioresour Technol ; 314: 123740, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32622281

RESUMO

Plasma gasification of raw and torrefied woody, non-woody, and algal biomass using three different gasifying agents (air, steam, and CO2) is conducted through a thermodynamic analysis. The impacts of feedstock and reaction atmosphere on various performance indices such as syngas yield, pollutant emissions, plasma energy to syngas production ratio (PSR), and plasma gasification efficiency (PGE) are studied. Results show that CO2 plasma gasification gives the lowest PSR, thereby leading to the highest PGE among the three reaction atmospheres. Torrefied biomass displays increased syngas yield and PGE, but is more likely to have a negative environmental impact of N/S pollutants in comparison with raw one, especially for rice straw. However, the exception is for torrefied grape marc and macroalgae which produce lower amounts of S-species under steam and CO2 atmospheres. Overall, torrefied pine wood has the best performance for producing high quality syngas containing low impurities among the investigated feedstocks.


Assuntos
Gases , Vapor , Biomassa , Madeira
15.
Bioresour Technol ; 314: 123756, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32629378

RESUMO

In light of the knowledge gap in the scale-up of microwave-assisted pyrolysis technology, this study developed a continuous microwave-assisted pyrolysis (CMAP) system and examined its feasibility for syngas production. Wood pellets were pyrolyzed in the system under various temperatures, and the product distribution and energy efficiency were investigated. At a processing temperature of 800 °C, the CMAP system obtained a high quality producer gas (lower heating value 18.0 MJ/Nm3 and a 67 vol% syngas content) at a yield of 72.2 wt% or 0.80 Nm3/kg d.a.f. wood, outperforming several conventional pyrolysis processes probably due to two factors: 1) reactions between primary tar and biochar enhanced by microwave irradiation, and 2) the absence of carrier gas in the process. Energy efficiency of the process was also assessed. Potentially the electricity consumption could be reduced from 7.2 MJ to 3.45 MJ per kg of wood, enabling net electricity production from the process.


Assuntos
Micro-Ondas , Pirólise , Biomassa , Temperatura Alta , Temperatura , Madeira
16.
Nature ; 583(7814): 72-77, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32612223

RESUMO

Forests provide a series of ecosystem services that are crucial to our society. In the European Union (EU), forests account for approximately 38% of the total land surface1. These forests are important carbon sinks, and their conservation efforts are vital for the EU's vision of achieving climate neutrality by 20502. However, the increasing demand for forest services and products, driven by the bioeconomy, poses challenges for sustainable forest management. Here we use fine-scale satellite data to observe an increase in the harvested forest area (49 per cent) and an increase in biomass loss (69 per cent) over Europe for the period of 2016-2018 relative to 2011-2015, with large losses occurring on the Iberian Peninsula and in the Nordic and Baltic countries. Satellite imagery further reveals that the average patch size of harvested area increased by 34 per cent across Europe, with potential effects on biodiversity, soil erosion and water regulation. The increase in the rate of forest harvest is the result of the recent expansion of wood markets, as suggested by econometric indicators on forestry, wood-based bioenergy and international trade. If such a high rate of forest harvest continues, the post-2020 EU vision of forest-based climate mitigation may be hampered, and the additional carbon losses from forests would require extra emission reductions in other sectors in order to reach climate neutrality by 20503.


Assuntos
Agricultura Florestal/estatística & dados numéricos , Agricultura Florestal/tendências , Florestas , Biodiversidade , Biomassa , Sequestro de Carbono , Monitoramento Ambiental , Política Ambiental/economia , Política Ambiental/legislação & jurisprudência , Europa (Continente) , União Europeia/economia , Agricultura Florestal/economia , Agricultura Florestal/legislação & jurisprudência , Aquecimento Global/prevenção & controle , História do Século XXI , Imagens de Satélites , Madeira/economia
17.
Water Sci Technol ; 81(9): 1882-1893, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32666943

RESUMO

Different types of commercial titania (P25, P90, PC500, and C-TiO2) were immobilized as single or mixed photocatalyst onto the surface of a natural support material made of cement, clay, and wood fibers. The successful immobilization was studied by different techniques showing a composite material with the mechanical properties of the support material and the photocatalytic behavior of the immobilized titania. The supported photocatalyst showed high mechanical stability and was applied to the photocatalytic degradation of phenol as a model pollutant under UV light irradiation. As the most active photocatalytic material, a mixture PC500 and P90 (comp-PC500/P90) was identified with an apparent pseudo first-order kinetic rate constant (kapp) of 0.010 min-1 at a degradation efficiency of 100%. The catalyst was used several times and showed minor loss in activity during four runs due to degradation intermediates adsorbed to the surface, shown by a color change from white to yellow.


Assuntos
Argila , Madeira , Catálise , Titânio
18.
Bioresour Technol ; 315: 123789, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32682260

RESUMO

To assess the impact of alkalinity on sulfonation and the enzyme-mediated hydrolysis of softwood cellulose, Lodgepole pine chips were impregnated with 8% sodium sulfite and increasing loadings of sodium carbonate before thermomechanical pulping. It was apparent that alkali addition enhanced lignin sulfonation with an additional 4% loading of sodium carbonate proving optimal. TEM indicated that sulfonation predominantly occurred within the secondary-cell-wall lignin, increasing cellulose accessibility to the cellulase enzymes. Although increasing alkalinity did not significantly enhance lignin sulfonation, likely due to the lower acetyl content of the softwood chips, it increases mannan solubilization. Despite their smaller particle size, softwood pellets were more poorly sulfonated, probably due to their higher lignin content and lower amount of acid groups. This more condensed lignin structure was confirmed by 2D-NMR and GPC analyses which indicated that the EMAL derived from softwood pellets contained less native ß-O-4 linkages and had a higher molecular weight.


Assuntos
Celulase , Madeira , Celulose , Hidrólise , Lignina
19.
Bioresour Technol ; 315: 123819, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32712513

RESUMO

This work aimed to use continuous measurements of viscoelastic properties to evaluate the effect of hydrothermal treatment on poplar samples. Different conditions (temperature and pre-soaking liquid: acidic, neutral and alkaline) were tested on wood in both tangential and radial directions. Two viscoelastic properties were determined: the modulus of elasticity and the stress relaxation. The applicability of these properties as indicators of the kinetics of biomass deconstruction was also evaluated, thanks to the chemical analyses performed on the treated solid and the recovered liquid phase. The ultimate goal is to build a macroscopic indicator capable of establishing rules to optimize the hydrothermal treatment before the explosion stage. The joint use of the two parameters succeeded in revealing the effects of chemical degradation, including the coexistence of cleavage and re-condensation and the impact of process conditions (temperature, residence time, and pre-soaking liquid). The monotonous behavior of stress relaxation is a major asset as a possible macroscopic indicator of biomass deconstruction.


Assuntos
Madeira , Biomassa , Elasticidade , Cinética , Temperatura
20.
PLoS One ; 15(6): e0234399, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32559225

RESUMO

BACKGROUND: Dengue, chikungunya, and Zika viruses are increasingly important public health problems. Burning vegetation, leaves, and other plant products have been shown to be effective mosquito repellents for their vector, Aedes spp., but there has been scant research on whether firewood cooking smoke in households influences mosquito populations or mosquito-borne diseases. About 2.9 billion people worldwide use biomass fuel for household cooking and heating, resulting in an estimated 1.6 million deaths annually from household air pollution (HAP)-related diseases. Global health agencies now encourage households to transition from biomass to clean fuels, but it is unclear whether such interventions may actually increase risk for mosquito-borne diseases. This retrospective case-control study evaluated associations between arboviral infections and cooking with firewood in Santa Rosa, Guatemala. METHOD: Vigilancia Integrada Comunitaria (VICo) was a prospective public health surveillance system for bacterial, parasitic, and viral causes of diarrheal, neurological, respiratory, and febrile illnesses in hospitals and clinics in the department of Santa Rosa, Guatemala. Enrolled VICo in-patients and out-patients during 2011-2018 were interviewed using standardized questionnaires on demographics and household characteristics. Blood and stool specimens were collected and tested to identify the etiologies presenting symptoms. Cases were defined as laboratory-positive for dengue, chikungunya, or Zika virus infections. Controls were laboratory-positive for bacterial and viral diarrheal illnesses (e.g., Salmonella, Shigella, Campylobacter, Escherichia coli, rotavirus, norovirus, sapovirus, or astrovirus). Cooking with firewood, kitchen location, stove type, and firewood cooking frequency were the independent exposure variables. Logistic regression models were used to analyze unadjusted and adjusted associations between arboviral infections and exposures of interest. RESULT: There were 311 arboviral cases and 1,239 diarrheal controls. Arboviral infections were inversely associated with cooking with firewood in the main house (AOR: 0.22; 95% CI: 0.08-0.57), cooking with firewood on an open hearth (AOR: 0.50; 95% CI: 0.33-0.78), and cooking with firewood ≥5 times per week (AOR: 0.54; 95% CI: 0.36-0.81), adjusting for age, sex, ethnicity, socioeconomic status index, number of people per household, community population density, community elevation, recruitment location, season, and admission year. CONCLUSION: Several primary determinants of HAP exposure were inversely associated with arboviral infections. Additional studies are needed to understand whether interventions to reduce HAP might actually increase risk for mosquito-borne infectious diseases, which would warrant improved education and mosquito control efforts in conjunction with fuel interventions.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Febre de Chikungunya/epidemiologia , Dengue/epidemiologia , Infecção por Zika virus/epidemiologia , Adolescente , Adulto , Aedes/virologia , Animais , Estudos de Casos e Controles , Criança , Culinária , Características da Família , Feminino , Fogo , Guatemala/epidemiologia , Humanos , Repelentes de Insetos/análise , Modelos Logísticos , Masculino , Mosquitos Vetores/virologia , Estudos Retrospectivos , Fatores de Risco , Fumaça/análise , Madeira , Adulto Jovem
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