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Robust, ultrathin, and environmental-friendliness papers that synergize high-efficiency electromagnetic interference (EMI) shielding, personal thermal management, and wearable heaters are essential for next-generation smart wearable devices. Herein, MXene nanocomposite paper with a nacre-like structure for EMI shielding and electrothermal/photothermal conversion is fabricated by vacuum filtration of Ti3 C2 Tx MXene and modified sawdust. The hydrogen bonding and highly oriented structure enhance the mechanical properties of the modified sawdust/MXene composite paper (SM paper). The SM paper with 50 wt% MXene content shows a strength of 23 MPa and a toughness of 13 MJ·M-3 . The conductivity of the SM paper is 10 195 S·m-1 , resulting in an EMI shielding effectiveness (SE) of 67.9 dB and a specific SE value (SSE/t) of 8486 dB·cm2 ·g-1 . In addition, the SM paper exhibits excellent thermal management performance including high light/electro-to-thermal conversion, rapid Joule heating and photothermal response, and sufficient heating stability. Notably, the SM paper exhibits low infrared emissivity and distinguished infrared stealth performance, camouflaging a high-temperature heater surface of 147-81 °C. The SM-based e-skin achieves visualization of Joule heating and realizes human motions monitoring. This work presents a new strategy for designing MXene-based wearable devices with great EMI shielding, artificial intelligence, and thermal management applications.
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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.
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Metais Pesados , Oryza , Biomassa , Carvão Vegetal , Esgotos , MadeiraRESUMO
The objective of this study was to investigate the effect of addition of sawdust co-composted with sewage sludge and wheat straw on seeds germination. Two mixtures were piled and composted over 90 days. The first mixture (C1) was composed of sewage sludge and wheat straw, while the second mixture (C2) was composed of sewage sludge, wheat straw and wood sawdust. The results showed that the physicochemical parameters of both composts, i.e., temperature (> 55⯰C in the thermophilic phase), moisture content (~ 30%). pH (6.73 for C1 and 7.19 for C2) and EC values (1.81â¯mSâ¯cm-1 for C1 and 1.32â¯mSâ¯cm-1 for C2) reached the required maturity standard. The values of C/N were below 12 indicating a high degree of maturity. Also, no bacterial pathogens were detected in the final composts. The concentration of total heavy metals has been reduced allowing the elimination of sewage sludge toxicity, confirmed by the germination index, which reached over 80%. Strong positive correlations were noticed between total Kjeldahl nitrogen of C2 and germination indexes of all the studied species. The obtained results indicate that the addition of wood sawdust increases the nitrogen content leading to slightly alkaline compost which influences seeds germination by reducing the phytotoxicity of sewage sludge.
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Compostagem , Germinação , Sementes/fisiologia , Esgotos/química , Madeira , Brassica rapa/fisiologia , Carbono/análise , Enterobacteriaceae/isolamento & purificação , Escherichia coli , Concentração de Íons de Hidrogênio , Lepidium sativum/fisiologia , Lactuca/fisiologia , Nitrogênio/análise , Saneamento , Esgotos/microbiologia , Solo/química , Microbiologia do Solo , Streptococcaceae , Temperatura , TriticumRESUMO
Nano-/microplastics accumulate in aquatic bodies and raise increasing threats to ecosystems and human health. The limitation of existing water cleanup strategies, especially in the context of nano-/microplastics, primarily arises from their complexity (morphological, compositional, and dimensional). Here, highly efficient and bio-based flowthrough capturing materials (bioCap) are reported to remove a broad spectrum of nano-/microplastics from water: polyethylene terephthalate (anionic, irregular shape), polyethylene (net neutral, irregular shape), polystyrene (anionic and cationic, spherical shape), and other anionic and spherical shaped particles (polymethyl methacrylate, polypropylene, and polyvinyl chloride). Highly efficient bioCap systems that adsorb the ubiquitous particles released from beverage bags are demonstrated. As evidence of removal from drinking water, the in vivo biodistribution of nano-/microplastics is profiled, confirming a significant reduction of particle accumulation in main organs. The unique advantage of phenolic-mediated multi-molecular interactions is employed in sustainable, cost-effective, and facile strategies based on wood sawdust support for the removal of challenging nano-/microplastics pollutions.
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Microplásticos , Poluentes Químicos da Água , Humanos , Plásticos , Polifenóis , Ecossistema , Madeira/química , Distribuição Tecidual , Monitoramento Ambiental , ÁguaRESUMO
The objective of this article aims to reduce indoor air pollution through the use of ecological fire starter (EFS) made from sawdust and vegetable oils. In the Far North region of Cameroon, plastic waste is used to ignite and stoke solid fuels fires, exposing mainly women and children who are responsible for cooking to health risks from indoor air pollution. Thus, the survey conducted among the population of the region shows that 96% of urban households use plastics waste made with LDPE, HDPE, PET, PS, PP and EVA as fire starter for solid fuels. In the region, 5544 tons of plastic used by households could emit approximately 15,314 tons of CO2 eq per year. The region has a manufacturing capacity of 1000 tons of EFS while its need is 894 tons in 2022. The lower heating value of the EFS varies between 31.914 ± 0.810 and 25.127 ± 0.026 MJ/kg, and have many ecological health and economic advantages. A household needs about 10 g of EFS to ignite solid fuel per day, with an annual expenditure ranging from 5.5 and US$ 7 to purchase EFS. Therefore, it is important to promote EFS through developing countries and look for another way to recover plastic waste.
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Bentonitic clay and wood sawdust are natural materials widely available in nature at low cost with high heavy metals sorption properties that, in this work, were combined to achieve an effective composite biosorbent with high sorption properties and enhanced mechanical stability. Pine, aspen, and birch wood sawdust, as well as different bentonite clays and different sawdust modification methods (H3PO4 or HCl) were used for preparing new composite biosorbents. A mixture of wood sawdust and bentonite in a ratio of 2:1 was used. All materials were characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM) methods and tested for Cu and Ni ions removal from water. The adsorption process for all composite biosorbents was well described from a pseudo-second order kinetic model (R2 > 0.9999) with a very high initial adsorption rate of Cu and Ni ions and a maximum uptake recorded within 2 h. The results have shown that the adsorption capacity depends mainly on the kind of wood and the acid treatment of the wood that enhances the adsorption capacity. At a concentration of 50 mg/L, the biosorbent prepared using birch wood sawdust showed the worst performance, removing barely 30% of Cu and Ni ions, while aspen wood sawdust improved the adsorption of Cu (88.6%) and Ni (52.4%) ions. Finally, composite biosorbent with pine wood sawdust showed the best adsorption be haviour with an efficiency removal of 98.2 and 96.3% of Cu and Ni ions, respectively, making it a good candidate as an inexpensive and effective biosorbent for the removal of heavy metals.
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L. monocytogenes is a zoonotic foodborne pathogen with inherent adaptability to tolerate environmental and physiological stresses, thereby causing severe disease outbreaks. Antibiotic resistant foodborne pathogens are a challenge to the food industry. A total of 18 samples were pooled from a bio-digester co-digesting swine manure/pinewood sawdust, and evaluated for the occurrence of bacterium plus total viable counts using the spread plate method. The recovered bacterial isolates were presumptively identified by growth on selective medium and confirmed by biochemical characterisation, leading to the isolation of 43 L. monocytogenes. The isolates were characterized based on their susceptibility to antibiotics via the Kirby-Bauer disc diffusion technique against a panel of 14 antibiotics. Equally, the multiple antibiotic resistance (MAR) index was calculated, and MAR phenotypes generated. The bacterial counts were between 102 and104 cfu/mL. Complete susceptibility (100%) was demonstrated to ampicillin, gentamicin and sulfamethoxazole, which are the drugs of choice in the treatment of listeriosis. In addition, intermediate sensitivity occurred at 25.58% to cefotaxime, and the highest resistance (51.16%) was exhibited against nalidixic acid. The MAR index ranged from 0 to 0.71. Overall, 41.86% of the Listeria isolates displayed multidrug resistance, with 18 different MAR phenotypes, demonstrating CIP, E, C, TET, AUG, S, CTX, NA, AML, NI as the greatest MAR phenotype. It can be concluded that the isolates yielding MAR > 0.2 originated from the farm, where antibiotics had been in routine use. Therefore, strict monitoring of antibiotics use in the farm is crucial to mitigate further increase in antibiotic resistance amongst these bacterial isolates.
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This research addresses the importance of pine wood sawdust granulometry on the processing of medium-density polyethylene (MDPE)/wood composites by rotational molding and its effects on the morphological, mechanical and aesthetical properties of parts, aiming to contribute for the development of sustainable wood polymer composites (WPC) for rotational molding applications. Pine wood sawdust was sieved (<150, 150, 300, 500, 710, >1000 µm) and analyzed for its physical, morphological and thermal characteristics. Rotational molded parts were produced with matrix/wood ratios from 90/10 to 70/30 wt% considering different wood granulometries. As a natural material, wood changed its color during processing. Granulometries below 500 µm presented better sintering, homogeneity and less part defects. Furthermore, 300-500 µm favored the impact resistance (1316 N), as irregular brick-shaped wood was able to anchor to PE despite the weak interfacial adhesion observed. The increase of wood content from 10 to 30% reduced the impact properties by 40%, as a result of a highly porous structure formed, revealing sintering difficulties during processing. WPC parts of differentiated aesthetics and functionalities were achieved by rotational molding. A clear relationship between wood granulometry and WPC processing, structure and properties was identified.
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Here, water-suspended smoke aerosol preparation was synthesized from biomass-based fuel, i.e., a widespread product for residential heating, wood sawdust (WP) (pine, poplar, and birch mixture), and its properties were compared in parallel experiments with the smoke preparation from plastics (PP). Molecular groups in the PM preparations were analyzed using Raman and Fourier-transform infrared spectroscopy. WP was assessed in neurotoxicity studies using rat cortex nerve terminals (synaptosomes). Generation of spontaneous and H2O2-evoked reactive oxygen species (ROS) detected using fluorescent dye 2',7'-dichlorofluorescein in nerve terminals was decreased by WP. In comparison with PP, WP demonstrated more pronounced reduction of spontaneous and H2O2-evoked ROS production. WP completely inhibited glutamate receptor agonist kainate-induced ROS production, thereby affecting the glutamate receptor-mediated signaling pathways. WP decreased the synaptosomal membrane potential in fluorimetric experiments and the synaptosomal transporter-mediated uptake of excitatory and inhibitory neurotransmitters, L-[14C]glutamate and [3H] γ-aminobutyric acid (GABA), respectively. PP decreased the ambient synaptosomal level of [3H]GABA, whereas it did not change that of L-[14C]glutamate. Principal difference between WP and PP was found in their ability to influence the ambient synaptosomal level of [3H]GABA (an increase and decrease, respectively), thereby showing riskiness in mitigation of synaptic inhibition by PP and triggering development of neuropathology.
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Material Particulado , Fumaça , Animais , Ácido Glutâmico/metabolismo , Peróxido de Hidrogênio/farmacologia , Estresse Oxidativo , Material Particulado/metabolismo , Plásticos/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Receptores de Glutamato/metabolismo , Análise Espectral , Madeira/metabolismo , Ácido gama-Aminobutírico/metabolismoRESUMO
Reclaimed asphalt binder (RAB) releases large amounts ·of hazardous sulfur-containing gases during combustion. This study attempts to introduce wood sawdust (WS) as an in-situ inhibitor of sulfur release during the combustion of refuse-derived fuel (RDF) blended with RAB-WS. The combustion characteristics, gaseous sulfur-containing products, interactions and combustion kinetics of RDF were investigated through thermogravimetry and mass spectrometry (TG-MS), and the mechanisms on migration and distribution of sulfur were revealed. Results indicated that WS additive inhibits the volatilization of light components and promotes the degradation of macromolecular components. WS addition improved the combustibility, burnout performance and combustion stability of RAB. The sulfur release of RAB-based RDF was mainly derived from resins and asphaltenes. WS addition generally decreased all gaseous sulfur-containing compounds (CH3SH, COS, SO2, CS2 and thiophene). Interactions between RAB and WS restrained all sulfur-containing gas emissions, and the normalized sulfur inhibition ratio reached 40.99 %. The Sarink and DAEM models could well describe the kinetic process of the co-combustion of RAB and WS. WS addition led to a decrease in activation energy, namely, it lowered the reaction barrier. Sulfur could be retained in-situ into incineration residue through the formation of sulfate minerals during the co-combustion of RAB and WS.
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Cellulose-rich amendments stimulate saprotrophic fungi in arable soils. This may increase competitive and antagonistic interactions with root-infecting pathogenic fungi, resulting in lower disease incidence. However, cellulose-rich amendments may also stimulate pathogenic fungi with saprotrophic abilities, thereby increasing plant disease severity. The current study explores these scenarios, with a focus on the pathogenic fungus Rhizoctonia solani. Saprotrophic growth of R. solani on cellulose-rich materials was tested in vitro. This confirmed paper pulp as a highly suitable substrate for R. solani, whereas its performance on wood sawdusts varied with tree species. In two pot experiments, the effects of amendment of R. solani-infected soil with cellulose-rich materials on performance of beetroot seedlings were tested. All deciduous sawdusts and paper pulp stimulated soil fungal biomass, but only oak, elder and beech sawdusts reduced damping-off of beetroot. Oak sawdust amendment gave a consistent stimulation of saprotrophic Sordariomycetes fungi and of seedling performance, independently of the time between amendment and sowing. In contrast, paper pulp caused a short-term increase in R. solani abundance, coinciding with increased disease severity for beet seedlings sown immediately after amendment. However, damping-off of beetroot was reduced if plants were sown two or four weeks after paper pulp amendment. Cellulolytic bacteria, including Cytophagaceae, responded to paper pulp during the first two weeks and may have counteracted further spread of R. solani. The results showed that fungus-stimulating, cellulose-rich amendments have potential to be used for suppression of R. solani. However, such amendments require a careful consideration of material choice and application strategy.
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Developing new generation of adsorbents for water treatment to reduce calcium hardness and producing high quality water is important and continuous trend. This manuscript is devoted with this direction. Thus, two novel magnetic nanocomposite adsorbents were synthesized by covalently binding of tartaric acid (TA) and citric acid (CA) to wood sawdust coated magnetic nanoparticles (WSD@Fe3 O4 NPs) using green microwave solvent-less technique. The adsorbents thus prepared WSD@Fe3 O4 NPs-TA and WSD@Fe3 O4 NPs-CA were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Preliminary batch experiments were performed to evaluate percentage of Ca(II) adsorbed by the bare WSD@Fe3 O4 NPs and its functionalized forms by TA and CA, as a function of pH (initial concentration 80 mg/L), indicated 59.5%, 84.70%, and 99.29%, respectively, at pH 7 as optimal value. To attain maximum adsorption capacity, effect of adsorbent dosage and contact time were also optimized for the two modified adsorbents. Accordingly, Ca(II) adsorption capacity was determined to be 18.4 mg/g as exhibited by WSD@Fe3 O4 NPs-TA. However, WSD@Fe3 O4 NPs-CA showed higher capacity value recorded to be 27.2 mg/g. The novel adsorbents were successfully applied for fast reduction of calcium hardness from real water samples, during 15-20 min and via two consecutive in situ batch operations. PRACTITIONER POINTS: This manuscript aims to minimize Ca(II) hardness in aqueous solutions by performing magnetic separation under external magnetic field. WSD was magnetized using Fe3 O4 then modified by using safe organic modifiers using of the benefits of solvent-less microwave radiation technique for adsorbent synthesis and functionalization. Two novel environmentally magnetic nanocomposites WSD@Fe3 O4 NPs-TA and WSD@Fe3 O4 NPs-CA were checked on real water samples.
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Micro-Ondas , Nanocompostos , Adsorção , Cálcio , Dureza , Água , MadeiraRESUMO
A natural fiber reinforced composite, belonging to the class of eco composites, based on ethylene-propylene-terpolymer rubber (EPDM) and wood wastes were obtained by electron beam irradiation at 75, 150, 300, and 600 kGy in atmospheric conditions and at room temperature using a linear accelerator of 5.5 MeV. The sawdust (S), in amounts of 5 and 15 phr, respectively, was used to act as a natural filler for the improvement of physical and chemical characteristics. The cross-linking effects were evaluated through sol-gel analysis, mechanical tests, and Fourier Transform Infrared FTIR spectroscopy comparatively with the classic method with dibenzoyl peroxide (P) applied on the same types of samples at high temperature. Gel fraction exhibits values over 98% but, in the case of P cross-linking, is necessary to add more sawdust (15 phr) to obtain the same results as in the case of electron beam (EB) cross-linking (5 phr/300 kGy). Even if the EB cross-linking and sawdust addition have a reinforcement effect on EPDM rubber, the medium irradiation dose of 300 kGy looks to be a limit to which or from which the properties of the composite are improved or deteriorated. The absorption behavior of the eco-composites was studied through water uptake tests.
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Water pollution by oil is a serious environmental problem. Developing new generation of benign adsorbents satisfying several criteria required for real practical application is of great need. This work introduces an effort in this direction, by utilizing a facile synthesis of wood sawdust coated magnetite nanoparticles functionalized stearic acid (WSD@Fe3O4NPs/SA) as a novel nano composite along with its precursor WSD@Fe3O4NPs. SA was covalently bonded to the precursor by amide bond formation via the interaction with the silylating agent 3-aminopropyltrimethoxysilane (3-APTS). This mode of binding is more stronger than the conventional ester bond. Fourier transform infrared (FT-IR), X- ray powder diffraction (XRD), Scanning electron microscope (SEM) and Transmittance electron microscope (TEM) were employed for characterization and follow up the synthesis process. Application of the newly synthesized magnetic nano composite adsorbent under optimized parameters of contact time (min) and composite dosage (g) reveal high removal capacity values (g/g) evaluated to be 28.32 g/g, 5 min and 0.1 g for used motor oil removal and 41.22 g/g, 10 min and 0.1 g for crude oil. The high removal efficiency exhibited by WSD@Fe3O4NPs/SA was mainly argued to the long hydrocarbon chain of SA moiety and additional ÙÙÙ (CH2)3 ÙÙÙ groups incorporated 3-ATPS. Moreover, Analysis of the oil adsorption experimental equilibrium data were well fitted with Freundlish model with correlation coefficients r2 = 0.9788 and 0.9896 for used motor oil and crude oil, respectively. The kinetic data were correlated using two kinetic models and the results were in harmony with pseudo-second order.
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Polyaniline/ Sawdust /Poly Ethylene Glycol/ (PANi/SD/PEG) composite synthesized chemically is used as an adsorbent to remove hexavalent chromium from water. Adsorption experiments have been done in batch and continuous (column) mode. Some parameter such as pH, contact time, PANi/SD/PEG dose, isotherms in batch mode and pH, column bed depth and fluid flow rate in column mode were investigated. Result shows that PANi/SD/PEG has a good performance to remove hexavalent chromium ion from aqueous media. By presence of PEG, prepared composite has been homogenized and further absorption has been occurred. The best adsorption occurs under pH 2 and optimum contact time for removal of hexavalent chromium ion in batch experiment was about 30 min. Adsorption of Cr (VI) by PANi/SD/PEG fitted well in Langmuir isotherms. Maximum adsorption of hexavalent chromium was calculated 3.2 (mg/g). In column experiments, pH and column bed depth were found to be more prominent than fluid flow rate. Though, about 22% of Cr (VI) can be recovered using 0.1 M NaOH in the batch system, the recovered Cr (VI) in column system was less than 7.9%.
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The aim of present research was to study the pyrolysis of wood sawdust in a semi batch reactor and explored the influence of pyrolysis process parameters on the products yield. Pyrolysis process parameters such as temperature, heating rate, nitrogen (N2) flow rate and particle size of wood sawdust were varied as 350-650⯰C, 10 and 50⯰C/min, 50-200â¯cm3/min and <0.25 to >1.7â¯mm, respectively. The maximum bio-oil yield was found as 44.16â¯wt% at temperature of 500⯰C, heating rate of 50⯰C/min and nitrogen flow rate of 100â¯cm3/min for particle size range of 0.6â¯<â¯dpâ¯<â¯1â¯mm. The composition and characteristics of bio-oil and bio-char were determined. Different methods such as ultimate analysis, Fourier transformed infrared spectroscopy (FTIR), Gas chromatography-mass spectroscopy (GC-MS), and Nuclear magnetic resonance spectroscopy (1H NMR) were used to characterize bio-oil. Boiling point range of bio-oil was found in between 63 and 360⯰C. Bio-char and original biomass were analyzed by physicochemical, thermogravimetric as well as analytical methods using sophisticated instruments such as Field emission scanning electron microscope (FESEM), and X-ray diffractometer (XRD).
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Biocombustíveis , Madeira , Biomassa , Temperatura Alta , Pirólise , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The present study explores the utilisation of a new raw material from lignocellulose biomass, Meranti wood sawdust (MWS) for high commercial value xylooligosaccharides (XOS) production using immobilised xylanase. The xylanase was immobilised by a combination of entrapment and covalent binding techniques. The hemicellulosic xylan from MWS was extracted using a standard chlorite delignification method. The production of total and derivatives of XOS from the degradation of the hemicellulosic xylan of MWS were compared to the production from the commercial xylan from Beechwood. The utilisation of the extracted xylan from MWS yielded 0.36 mg/mL of total XOS after 60 h of hydrolysis. During the hydrolysis reaction, the immobilised xylanase released a lower degree of polymerisation (DP) of XOS, mainly X2 and X3, which were the major products of xylan degradation by xylanase enzymes. The production of XOS with a lower DP from MWS demonstrated the biotechnological potential of the MWS in the future. The XOS production retained about 70% of its initial XOS production during the second cycle. This is also the first report on the utilisation of MWS wastes in enzymatic hydrolysis using immobilised xylanase for XOS production.
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Enzimas Imobilizadas/química , Glucuronatos/síntese química , Oligossacarídeos/síntese química , Madeira , Xilosidases/química , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Microwave-assisted pyrolysis of wood sawdust for phenolic rich compounds was carried out between 400 and 550°C in a batch reactor. An efficient preparation of liquid products was observed at 500°C with a yield of 58.50%, which was similar to conventional fast pyrolysis. The highest concentration of phenolic compounds in liquid product reached up to 78.7% (area) in which the alkoxy phenols contributed 81.8% at 500°C. Microwave thermogravimetric analysis using KAS method was used firstly to investigate the low-temperature pyrolytic behaviors and activation energy. The results indicated that effective pyrolytic range was 250-400°C and average activation energy was 42.78kJ/mol, which were 50-100°C and 50-100kJ/mol lower than conventional pyrolysis, respectively. Analysis on dielectric properties of pyrolytic products confirmed that accelerated pyrolysis and low temperature were attributed to the formation of instantaneous "hot spots".
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Micro-Ondas , Madeira , Temperatura Baixa , Temperatura Alta , Cinética , Fenóis , Eliminação de Resíduos , TemperaturaRESUMO
The obtaining and characterization of some polymeric eco-composites based on wood sawdust and natural rubber is presented. The natural rubber was cross-linked using the electron beam irradiation. The irradiation doses were of 75, 150, 300 and 600 kGy and the concentrations of wood sawdust were of 10 and 20 phr, respectively. As a result of wood sawdust adding, the physical and mechanical properties such as hardness, modulus at 100% elongation and tensile strength, showed significant improvements. The presence of wood sawdust fibers has a reinforcing effect on natural rubber, similar or better than of mineral fillers. An increase in the irradiation dose leads to the increasing of cross-link density, which is reflected in the improvement of hardness, modulus at 100% elongation and tensile strength of blends. The cross-linking rates, appreciated using the Flory-Rehner equation, have increased with the amount of wood sawdust in blends and with the irradiation dose. Even if the gel fraction values have varied irregularly with the amount of wood sawdust and irradiation dose it was over 90% for all blends, except for the samples without wood sawdust irradiated with 75 kGy. The water uptake increased with increasing of fiber content and decreased with the irradiation dose.
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Activated carbon fibers (ACFs) with different pore structure have been prepared from wood sawdust using the KOH activation method. A study was conducted to examine the influence of the activation parameters (temperature, alkali/carbon ratio, and time) on the morphology and structure of the as-prepared ACFs developed in the process of pore generation and evolution. Activation temperature was very essential for the formation of utramicropores (<0.6 nm), which greatly contributed to the electric double layer capacitance. The significance of metallic potassium vapor evolved when the temperature was above 800 °C, since the generation of 0.8- and 1.1 nm micropores cannot be ignored. When the the KOH/fiber ratio was increased and the activation time was prolonged, to some extent, the micropores were enlarged to small mesopores within 2-5 nm. The sample with the optimal condition exhibited the highest specific capacitance (225 F g(-1) at a current density of 0.5 A g(-1)). Its ability to retain capacitance corresponding to 10 A g(-1) and 6 M KOH was 85.3%, demonstrating a good rate capability. With 10â¯000 charge-discharge cycles at 3 A g(-1), the supercapacitor kept 94.2% capacity, showing outstanding electrochemical performance as promising electrode material.