Pub Date : 2021-03-08DOI: 10.37763/WR.1336-4561/66.1.141152
Wang Minghua, Li Ming, Tingting Deng, Saiyin Fang, Liao Xiaosong, L. Fei
Through the time-frequency analysis of the propagation waveform of the acoustic emission (AE) signal propagating in the thin sheet of Pinus sylvestris var. mongolica, the propagation characteristics of the stress wave when propagating as a lamb wave was studied. An AE source was generated on the surface of the specimen, the discrete wavelet transform method was used to achieve AE signal de-noising and reconstruct the waveform of the AE signal. On this basis, the time difference positioning method was used to calculate the propagation velocity of lamb waves, and compared with the propagation characteristics of lamb waves in the metal specimen. The results show that the high-frequency mode of lamb waves attenuated sharply as they propagate in the thin wood sheet, indicating that the microstructure of wood has a significant low-pass characteristic for lamb waves. The average attenuation rates of lamb waves in metal and thin wood sheet were 87.1% and 75.7%, and the velocity was 4447.0 m.s-1 and 1186.3 m.s-1, respectively. This shows that AE signals can travel longer distances in the thin wood sheet, but the propagation velocity is significantly reduced.
{"title":"Study on lamb wave propagation characteristics along the grain of thin wood sheet","authors":"Wang Minghua, Li Ming, Tingting Deng, Saiyin Fang, Liao Xiaosong, L. Fei","doi":"10.37763/WR.1336-4561/66.1.141152","DOIUrl":"https://doi.org/10.37763/WR.1336-4561/66.1.141152","url":null,"abstract":"Through the time-frequency analysis of the propagation waveform of the acoustic emission (AE) signal propagating in the thin sheet of Pinus sylvestris var. mongolica, the propagation characteristics of the stress wave when propagating as a lamb wave was studied. An AE source was generated on the surface of the specimen, the discrete wavelet transform method was used to achieve AE signal de-noising and reconstruct the waveform of the AE signal. On this basis, the time difference positioning method was used to calculate the propagation velocity of lamb waves, and compared with the propagation characteristics of lamb waves in the metal specimen. The results show that the high-frequency mode of lamb waves attenuated sharply as they propagate in the thin wood sheet, indicating that the microstructure of wood has a significant low-pass characteristic for lamb waves. The average attenuation rates of lamb waves in metal and thin wood sheet were 87.1% and 75.7%, and the velocity was 4447.0 m.s-1 and 1186.3 m.s-1, respectively. This shows that AE signals can travel longer distances in the thin wood sheet, but the propagation velocity is significantly reduced.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":"66 1","pages":"141-152"},"PeriodicalIF":1.3,"publicationDate":"2021-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43317368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-08DOI: 10.37763/WR.1336-4561/66.1.8594
S. Mohomane, S. Motloung, L. Koao, T. Motaung
This study investigates the effect of silica on sugarcane bagasse (SCB) and softwood (SW) cellulose. Cellulose was extracted from raw SCB and SW chips using a three-step process, namely thermal pre-treatment, alkaline treatment and bleaching treatment. Alkali treated cellulose was then subjected to silica surface modification using the solvent exchange method. The effect of silica modification on SCB and SW cellulos was investigated using X-ray diffractions analysis (XRD), Fourier transform infrared (FTIR) spectroscopy and optical microscope (OPM) techniques. Both the FTIR and XRD results confirm successful extraction of cellulose from both raw fibers and addition of silane functional groups in the cellulose surface. XRD patterns of all samples revealed typical spectra for natural fibers corresponding to crystalline peaks of cellulose and undissolved amorphous hemicellulose respectively. SCB and SW showed similar increasing patterns of crystallinity with nanosilica surface modification. The surface morphology results showed that both SCB and SW cellulose modified with silica were swollen and displayed small particles agglomerating on the surface of the fibers. The solvent exchange method proved to be a successful method for modifying SCB and SW cellulose with nanosilica. It also proved to be cost-efficient and time-efficient.
{"title":"Effect of silica on alkaline bagasse cellulose and softwood cellulose","authors":"S. Mohomane, S. Motloung, L. Koao, T. Motaung","doi":"10.37763/WR.1336-4561/66.1.8594","DOIUrl":"https://doi.org/10.37763/WR.1336-4561/66.1.8594","url":null,"abstract":"This study investigates the effect of silica on sugarcane bagasse (SCB) and softwood (SW) cellulose. Cellulose was extracted from raw SCB and SW chips using a three-step process, namely thermal pre-treatment, alkaline treatment and bleaching treatment. Alkali treated cellulose was then subjected to silica surface modification using the solvent exchange method. The effect of silica modification on SCB and SW cellulos was investigated using X-ray diffractions analysis (XRD), Fourier transform infrared (FTIR) spectroscopy and optical microscope (OPM) techniques. Both the FTIR and XRD results confirm successful extraction of cellulose from both raw fibers and addition of silane functional groups in the cellulose surface. XRD patterns of all samples revealed typical spectra for natural fibers corresponding to crystalline peaks of cellulose and undissolved amorphous hemicellulose respectively. SCB and SW showed similar increasing patterns of crystallinity with nanosilica surface modification. The surface morphology results showed that both SCB and SW cellulose modified with silica were swollen and displayed small particles agglomerating on the surface of the fibers. The solvent exchange method proved to be a successful method for modifying SCB and SW cellulose with nanosilica. It also proved to be cost-efficient and time-efficient.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":"66 1","pages":"85-94"},"PeriodicalIF":1.3,"publicationDate":"2021-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46312748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-08DOI: 10.37763/WR.1336-4561/66.1.2738
Wengang Hu, Bingrui Chen, Tianxing Zhang
Effect of loading type (compression and tension) on mechanical properties, including elastic constants, yield strength and ultimate strength of beech (Fagus orientalis) wood were studied based on experimental and numerical methods. The mechanical behaviors of beech wood in compressive and tensile states were simulated by finite element method (FEM) using mechanical parameters measured in an experiment. The results showed that the effect of loading types on mechanical properties of beech was statistically significant. The elastic moduli measured in tension were all bigger than those in compression, but the Poisson’s ratios determined in compression were bigger than those in tension. In compressive state, the yield and ultimate strengths of beech in longitudinal grain orientation were all smaller than those measured in tensile state, while the yield and ultimate strengths of beech in radial and tangential directions were higher than those of longitudinal direction. The results of the FEM in compression and tension were all well consistent with those measured by experiments respectively, and the average errors were all within 13.69%. As a result, the finite element models proposed in this study can predict the mechanical behaviors of wood in tensile and compressive states.
{"title":"Experimental and numerical studies on mechanical behaviors of beech wood under compressive and tensile states","authors":"Wengang Hu, Bingrui Chen, Tianxing Zhang","doi":"10.37763/WR.1336-4561/66.1.2738","DOIUrl":"https://doi.org/10.37763/WR.1336-4561/66.1.2738","url":null,"abstract":"Effect of loading type (compression and tension) on mechanical properties, including elastic constants, yield strength and ultimate strength of beech (Fagus orientalis) wood were studied based on experimental and numerical methods. The mechanical behaviors of beech wood in compressive and tensile states were simulated by finite element method (FEM) using mechanical parameters measured in an experiment. The results showed that the effect of loading types on mechanical properties of beech was statistically significant. The elastic moduli measured in tension were all bigger than those in compression, but the Poisson’s ratios determined in compression were bigger than those in tension. In compressive state, the yield and ultimate strengths of beech in longitudinal grain orientation were all smaller than those measured in tensile state, while the yield and ultimate strengths of beech in radial and tangential directions were higher than those of longitudinal direction. The results of the FEM in compression and tension were all well consistent with those measured by experiments respectively, and the average errors were all within 13.69%. As a result, the finite element models proposed in this study can predict the mechanical behaviors of wood in tensile and compressive states.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44935813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-07DOI: 10.37763/WR.1336-4561/66.1.7184
J. Gigac, M. Fišerová, S. Hegyi
UHF RFID printed antennas on conventional and experimentally coated papers by thermal transfer and inkjet technique were not conductive due to high surface roughness. Reducing the surface roughness of paper and hence the electrical resistance of the antennas printed by thermal transfer and inkjet printing was achieved by coating and subsequent calendering process. Papers for thermal transfer and inkjet printed of aluminum and silver antennas were prepared by coating with top functional coating, whose main component was pigment precipitated calcium carbonate with addition of polyvinyl alcohol, cationic polymer PDADMAC and glyoxal. The desired quality of inkjet-printed silver antennas was achieved by using coated paper with a polyvinyl alcohol barrier layer and a top functional hydrophilic layer. Silver nanoparticles of inkjet ink require a sintering process to obtain a conductive printed trace. The microstructure and thickness of antennas printed by thermal transfer and inkjet technique were compared. Thermal transfer printing created a more homogeneous antenna with greater sharpness of drawing compared to inkjet printing.
{"title":"Comparison of thermal transfer and inkjet printing of UHF RFID tag antennas on paper substrates","authors":"J. Gigac, M. Fišerová, S. Hegyi","doi":"10.37763/WR.1336-4561/66.1.7184","DOIUrl":"https://doi.org/10.37763/WR.1336-4561/66.1.7184","url":null,"abstract":"UHF RFID printed antennas on conventional and experimentally coated papers by thermal transfer and inkjet technique were not conductive due to high surface roughness. Reducing the surface roughness of paper and hence the electrical resistance of the antennas printed by thermal transfer and inkjet printing was achieved by coating and subsequent calendering process. Papers for thermal transfer and inkjet printed of aluminum and silver antennas were prepared by coating with top functional coating, whose main component was pigment precipitated calcium carbonate with addition of polyvinyl alcohol, cationic polymer PDADMAC and glyoxal. The desired quality of inkjet-printed silver antennas was achieved by using coated paper with a polyvinyl alcohol barrier layer and a top functional hydrophilic layer. Silver nanoparticles of inkjet ink require a sintering process to obtain a conductive printed trace. The microstructure and thickness of antennas printed by thermal transfer and inkjet technique were compared. Thermal transfer printing created a more homogeneous antenna with greater sharpness of drawing compared to inkjet printing.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":"66 1","pages":"71-84"},"PeriodicalIF":1.3,"publicationDate":"2021-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45441203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-18DOI: 10.37763/wr.1336-4561/65.6.9891000
Quan Li, Ren-Bao Liu, Xiaoqian Chen, Hui Lin
High performance bamboo-based composite panel taking bamboo mats, bamboo curtains and poplar veneers are used as raw material, is manufactured from the each layers slab was crisscrossed, impregnated with phenolic resin, compressed and cured. The product was optimized by Box-Behnken model design and data analysis. The results show that the best parameter conditions were hot pressing temperature of 140°C, hot pressing time of 94 s.mm-1, and hot pressing pressure of 2.5 MPa. The model was validated according to the optimal process parameters and the static bending strength (MOR), elastic modulus (MOE), thickness expansion rate of water absorbing, adhesive strength and density are 98.95 MPa, 8.81 GPa, 4.7%, 1.25 MPa, 0.89 g.cm-3, respectively. The actual value is close to the predicted value, confirming that the obtained model can accurately predict the MOR of the product using the three factors of hot pressing as variables under different conditions.
{"title":"Box-Behnken design for process parameters optimalization of bamboo-based composite panel manufacturing.","authors":"Quan Li, Ren-Bao Liu, Xiaoqian Chen, Hui Lin","doi":"10.37763/wr.1336-4561/65.6.9891000","DOIUrl":"https://doi.org/10.37763/wr.1336-4561/65.6.9891000","url":null,"abstract":"High performance bamboo-based composite panel taking bamboo mats, bamboo curtains and poplar veneers are used as raw material, is manufactured from the each layers slab was crisscrossed, impregnated with phenolic resin, compressed and cured. The product was optimized by Box-Behnken model design and data analysis. The results show that the best parameter conditions were hot pressing temperature of 140°C, hot pressing time of 94 s.mm-1, and hot pressing pressure of 2.5 MPa. The model was validated according to the optimal process parameters and the static bending strength (MOR), elastic modulus (MOE), thickness expansion rate of water absorbing, adhesive strength and density are 98.95 MPa, 8.81 GPa, 4.7%, 1.25 MPa, 0.89 g.cm-3, respectively. The actual value is close to the predicted value, confirming that the obtained model can accurately predict the MOR of the product using the three factors of hot pressing as variables under different conditions.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":"65 1","pages":"989-1000"},"PeriodicalIF":1.3,"publicationDate":"2020-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45845062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-18DOI: 10.37763/wr.1336-4561/65.6.975988
Selçuk Demirci, Harun Diler, Ali Kasal, Y. Z. Erdil
Effect of wood species, joint techniques, and adhesive type on bending moment resistances were investigated. 480 L-shaped joint specimens were tested including 2 loadings, 4 wood species, 3 joint techniques, 2 adhesives, and 10 replications. Specimens were prepared from Scotch pine, Oriental beech, oak, and chestnut. The joint techniques were dowel, half lap and open mortise and tenon, and type of adhesives were polyvinyl acetate (PVAc) and polyurethane (PU). Bending moment resistance of the joints under compression ranged from a low of 60 Nm for Scotch pine dowel joints with PVAc to oak half lap joints a high of 281 N.m w/PVAc. Bending moment resistance of the joints loaded in tension ranged from a low of 230 N.m for scotch pine dowel joints w/PVAc and to a maximum of 917 N.m for oak half lap joints w/PVAc. Highest average moment resistance was achieved with oak half lap jointed specimens w/PVAc, under both loadings.
{"title":"Bending moment resistances of L-shaped furniture frame joints under tension and compression loadings.","authors":"Selçuk Demirci, Harun Diler, Ali Kasal, Y. Z. Erdil","doi":"10.37763/wr.1336-4561/65.6.975988","DOIUrl":"https://doi.org/10.37763/wr.1336-4561/65.6.975988","url":null,"abstract":"Effect of wood species, joint techniques, and adhesive type on bending moment resistances were investigated. 480 L-shaped joint specimens were tested including 2 loadings, 4 wood species, 3 joint techniques, 2 adhesives, and 10 replications. Specimens were prepared from Scotch pine, Oriental beech, oak, and chestnut. The joint techniques were dowel, half lap and open mortise and tenon, and type of adhesives were polyvinyl acetate (PVAc) and polyurethane (PU). Bending moment resistance of the joints under compression ranged from a low of 60 Nm for Scotch pine dowel joints with PVAc to oak half lap joints a high of 281 N.m w/PVAc. Bending moment resistance of the joints loaded in tension ranged from a low of 230 N.m for scotch pine dowel joints w/PVAc and to a maximum of 917 N.m for oak half lap joints w/PVAc. Highest average moment resistance was achieved with oak half lap jointed specimens w/PVAc, under both loadings.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":"65 1","pages":"975-988"},"PeriodicalIF":1.3,"publicationDate":"2020-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45351161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-16DOI: 10.37763/wr.1336-4561/65.6.963974
Lin Yang, Tianqi Han, Yudong Fu
In order to improve dimensional stability and control deformation, heat treatment (HT) and wax impregnation (WI) were conducted to large size boards (LB) of Pterocarpus macrocarpus and the tangential swelling were compared in various relative humidity (RH) conditions. The results show that the tangential swelling and shrinking of control group and treated group performed differently corresponded to various relative humidity (RH). Comparing with control group, the swelling ratio of HT combined WI group was much less, and followed by 180°C-3h HT group. The maximum swelling ratio decreased by 31% and 29% in humidity chamber and indoor conditions respectively. The swelling ratio was affected by size of samples, LB showed smaller welling ratio than small sample. Wax filled in cell cavities and presented uneven distributions after impregnation. The rate of wood hygroscopicity was reduced after HT combined WI treatment which was an effective method on improvement of wood dimensional stability.
{"title":"Effect of heat treatment and wax impregnation on dimensional stability of Pterocarpus macrocarpus wood.","authors":"Lin Yang, Tianqi Han, Yudong Fu","doi":"10.37763/wr.1336-4561/65.6.963974","DOIUrl":"https://doi.org/10.37763/wr.1336-4561/65.6.963974","url":null,"abstract":"In order to improve dimensional stability and control deformation, heat treatment (HT) and wax impregnation (WI) were conducted to large size boards (LB) of Pterocarpus macrocarpus and the tangential swelling were compared in various relative humidity (RH) conditions. The results show that the tangential swelling and shrinking of control group and treated group performed differently corresponded to various relative humidity (RH). Comparing with control group, the swelling ratio of HT combined WI group was much less, and followed by 180°C-3h HT group. The maximum swelling ratio decreased by 31% and 29% in humidity chamber and indoor conditions respectively. The swelling ratio was affected by size of samples, LB showed smaller welling ratio than small sample. Wax filled in cell cavities and presented uneven distributions after impregnation. The rate of wood hygroscopicity was reduced after HT combined WI treatment which was an effective method on improvement of wood dimensional stability.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48111559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-16DOI: 10.37763/wr.1336-4561/65.6.925936
K. He, Yu Chen, Jiayu Sun
A total of forty-eight specimens were tested, including forty short timber columns at elevated temperatures and eight short timber columns left untreated at ambient temperature. The main parameters explored in the test include column heights (135, 180, 225 and 270 mm), elevated temperature duration (10, 20, 30, 40 and 50 min) and section form. It was found that two new failure modes were generated after the specimens exposed to the elevated temperatures: splitting failure and bottom crushing, and the ultimate bearing capacity of the specimens with bottom crushing is the lowest. The ductility of circular specimens increases with the increases of column height. When the elevated temperature duration reaches 50 min, the plasticity of the specimens basically subside. The ultimate bearing capacity of the timber columns decreases with the increase of the elevated temperature duration and the maximum reduction is about 60% percent.
{"title":"Axial mechanical properties of small-diameter round timber short columns after exposure to elevated temperatures.","authors":"K. He, Yu Chen, Jiayu Sun","doi":"10.37763/wr.1336-4561/65.6.925936","DOIUrl":"https://doi.org/10.37763/wr.1336-4561/65.6.925936","url":null,"abstract":"A total of forty-eight specimens were tested, including forty short timber columns at elevated temperatures and eight short timber columns left untreated at ambient temperature. The main parameters explored in the test include column heights (135, 180, 225 and 270 mm), elevated temperature duration (10, 20, 30, 40 and 50 min) and section form. It was found that two new failure modes were generated after the specimens exposed to the elevated temperatures: splitting failure and bottom crushing, and the ultimate bearing capacity of the specimens with bottom crushing is the lowest. The ductility of circular specimens increases with the increases of column height. When the elevated temperature duration reaches 50 min, the plasticity of the specimens basically subside. The ultimate bearing capacity of the timber columns decreases with the increase of the elevated temperature duration and the maximum reduction is about 60% percent.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42505441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-16DOI: 10.37763/wr.1336-4561/65.6.905916
Š. Boháček, A. Pažitný, M. Halaj, J. Balberčák, V. Kuňa
The paper is focused on the effect of freezing and cyclic freezing-thawing pretreatment of poplar sapwood (Populus alba L.). The experimental comparison was carried out by the sawdust fraction 0.7 mm as (a) water-saturated and (b) dry. Monosaccharide yields, as well as an amount of acetic acid, were measured after 6, 24, 48, 72, and 96 hours of enzymatic hydrolysis with 15% load of the enzyme measured to total cellulose content. The influence of freezing rate on total yields was observed on equally prepared samples with different weights (31 g, 25 g, 62.5 g, 125 g, 250 g, 500 g, and 1000 g) by "cubic" tests. To increase the efficiency of pretreatment, a cyclic freezing-thawing experiment at temperatures -20°C and +25°C was performed. The results show that single freezing of grounded poplar sapwood impregnated by water or dry in its matter is not a sufficient pretreatment method, so cyclic freeze-thaw is needed to enhance the yield of monosaccharides. Analysis of cubic test showed that slower freezing process has a positive effect on enzyme accessibility.
{"title":"Freeze-thaw pretreatment of poplar sapwood dust.","authors":"Š. Boháček, A. Pažitný, M. Halaj, J. Balberčák, V. Kuňa","doi":"10.37763/wr.1336-4561/65.6.905916","DOIUrl":"https://doi.org/10.37763/wr.1336-4561/65.6.905916","url":null,"abstract":"The paper is focused on the effect of freezing and cyclic freezing-thawing pretreatment of poplar sapwood (Populus alba L.). The experimental comparison was carried out by the sawdust fraction 0.7 mm as (a) water-saturated and (b) dry. Monosaccharide yields, as well as an amount of acetic acid, were measured after 6, 24, 48, 72, and 96 hours of enzymatic hydrolysis with 15% load of the enzyme measured to total cellulose content. The influence of freezing rate on total yields was observed on equally prepared samples with different weights (31 g, 25 g, 62.5 g, 125 g, 250 g, 500 g, and 1000 g) by \"cubic\" tests. To increase the efficiency of pretreatment, a cyclic freezing-thawing experiment at temperatures -20°C and +25°C was performed. The results show that single freezing of grounded poplar sapwood impregnated by water or dry in its matter is not a sufficient pretreatment method, so cyclic freeze-thaw is needed to enhance the yield of monosaccharides. Analysis of cubic test showed that slower freezing process has a positive effect on enzyme accessibility.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47905619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-16DOI: 10.37763/wr.1336-4561/65.6.10251030
J. M. B. Morillas, R. Maderuelo-Sanz, Pedro Atanasio-Moraga, V. G. Escobar, R. Vílchez-Gómez, G. R. Gozalo, D. M. González
This paper is a first study to evaluate the acoustical performance of virgin cork environmentally friendly by-product of the cork that can be used inside dwellings. To obtain the acoustical performance of the virgin cork, previously, it was properly treated and flattened into slabs, and later compared to commercial rock wool. The results obtained showed that this material, specially treated and added in some building system, could show good acoustic properties with a certain broadband absorption spectrum.
{"title":"Short note: Virgin cork, a possible environmentally friendly by-product of the cork with acoustic properties for its use inside dwellings?","authors":"J. M. B. Morillas, R. Maderuelo-Sanz, Pedro Atanasio-Moraga, V. G. Escobar, R. Vílchez-Gómez, G. R. Gozalo, D. M. González","doi":"10.37763/wr.1336-4561/65.6.10251030","DOIUrl":"https://doi.org/10.37763/wr.1336-4561/65.6.10251030","url":null,"abstract":"This paper is a first study to evaluate the acoustical performance of virgin cork environmentally friendly by-product of the cork that can be used inside dwellings. To obtain the acoustical performance of the virgin cork, previously, it was properly treated and flattened into slabs, and later compared to commercial rock wool. The results obtained showed that this material, specially treated and added in some building system, could show good acoustic properties with a certain broadband absorption spectrum.","PeriodicalId":23786,"journal":{"name":"Wood Research","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48296823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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