This article presents research focused on developing and scientifically substantiating a technology for producing environmentally friendly glued structures fromwood treated through a two-stage process.Themethodology i...This article presents research focused on developing and scientifically substantiating a technology for producing environmentally friendly glued structures fromwood treated through a two-stage process.Themethodology involves preliminary thermal modification followed by high-frequency low-temperature plasma treatment.Thermal modification enhances performance characteristics such as resistance to rot,lowers hygroscopicity,and increases dimensional stability.However,it can diminish the adhesive properties of wood,complicating the bonding process.To address this challenge,the study introduces high-frequency low-temperature plasma treatment,which activates the wood surface,improving wettability and adhesion while minimizing glue consumption.Experimental results indicate that plasma treatment reduces the contact angle by 46%and adhesive consumption during bonding by 24%,thereby enhancing the environmental friendliness of the glued structures.Furthermore,this dual treatment process increases the shear strength of adhesive joints by 22.7%and bending strength of glued beams by 66.6%,demonstrating a 30%lower carbon footprint compared to conventional methods.The findings affirm the efficacy of this technology in producing building materials,particularly glued beams for large-span structures.展开更多
This research investigates the behavior of sandwich glued laminated bamboo(Glubam)structures with a core formed by biodegradable plastic fibers,specifically polylactic acid(PLA),fabricated using 3D printing technology...This research investigates the behavior of sandwich glued laminated bamboo(Glubam)structures with a core formed by biodegradable plastic fibers,specifically polylactic acid(PLA),fabricated using 3D printing technology.The influence of various fiber printing orientations(0°and 45/135°)on tensile and compressive properties was investigated.The experimental results indicated that polylactic acid with calcium carbonate(PLA+)printed unidirectionally and aligned with the loading direction(0°)exhibits superior tensile and compressive strengths compared to specimens printed bidirectionally at 45/135°.Furthermore,the effect of additives on bioplastics of carbon fiber(PLA-CF)and glass fiber(PLA-GF)additives in PLA-based composites was evaluated in comparison with PLA+specimens.The finding indicated that PLA+has a higher strength-to-cost ratio compared to PLA-CF and PLA-GF.Therefore,unidirectionally printed PLA+was selected as the core material in two geometries:honeycomb and honeycomb lattice.These cores were sandwiched between Glubam panels on the top and bottom surfaces of the structures.Flexural performance was evaluated through four-point bending tests,which revealed that sandwich structures with a honeycomb core achieved a flexural strength-to-weight ratio 56.51%higher than those with a honeycomb lattice core.A parametric study using the finite element model was conducted to evaluate the effect of core scale,cross-sectional depth,Glubamthickness,core depth,and the number of honeycomb elements.The results showed that reducing the Glubam thickness while increasing the 3D-printed core depth significantly improved the flexural performance of honeycomb sandwich structures.Notably,reduced Glubam panel thickness coupled with increased core depth enhanced their flexural performance.展开更多
Recent studies show that a reduced effect of inhibitory transmitter system in the visual cortex may underlie aged visual function degradation. Whether excitatory transmitter system changes with age and hence affects i...Recent studies show that a reduced effect of inhibitory transmitter system in the visual cortex may underlie aged visual function degradation. Whether excitatory transmitter system changes with age and hence affects intracortical excitation-inhibition balance is not clear. To explore this issue, we used Nissl staining and immunohistochemical methods as well as Image-Pro Express software to examine the density of Nissl-stained neurons, Glutamie acid-immunoreactive （Glu-IR） neurons and T-Aminobutyric acid-immunoreactive （GABA-IR） neurons in the primary visual cortex of young adult and aged cats. The results showed that there was no significant difference in the density of Nissl-stained neurons between young and old cats （2〉0.05）. However, the density of Glu-IR neurons and GABA-IR neurons in the primary visual cortex of aged cats was significantly lower than that of young ones （P〈0.01）. The ratio between Glu-IR neurons and GABA-IR neurons was significantly increased in old cats compared to that in young adult ones （P〈0.01）. These results indicated that the effect of excitatory transmitter system in the old visual cortex was increased relative to the inhibitory transmitter system, which might cause an imbalance between cortical excitation and inhibition and might be an important factor mediating the visual function decline during aging.展开更多
基金funded by the Technostart competition,Agreement No.12-22(2-22)dated 01 February 2022.
文摘This article presents research focused on developing and scientifically substantiating a technology for producing environmentally friendly glued structures fromwood treated through a two-stage process.Themethodology involves preliminary thermal modification followed by high-frequency low-temperature plasma treatment.Thermal modification enhances performance characteristics such as resistance to rot,lowers hygroscopicity,and increases dimensional stability.However,it can diminish the adhesive properties of wood,complicating the bonding process.To address this challenge,the study introduces high-frequency low-temperature plasma treatment,which activates the wood surface,improving wettability and adhesion while minimizing glue consumption.Experimental results indicate that plasma treatment reduces the contact angle by 46%and adhesive consumption during bonding by 24%,thereby enhancing the environmental friendliness of the glued structures.Furthermore,this dual treatment process increases the shear strength of adhesive joints by 22.7%and bending strength of glued beams by 66.6%,demonstrating a 30%lower carbon footprint compared to conventional methods.The findings affirm the efficacy of this technology in producing building materials,particularly glued beams for large-span structures.
基金provided by the Thailand Science Research and Innovation(TSRI)through the Basic Research Fund,Fiscal Year 2026,for the project“Numerical Modeling and Structural Analysis of Composite Sections Built-up from Local Timber inThailand”.
文摘This research investigates the behavior of sandwich glued laminated bamboo(Glubam)structures with a core formed by biodegradable plastic fibers,specifically polylactic acid(PLA),fabricated using 3D printing technology.The influence of various fiber printing orientations(0°and 45/135°)on tensile and compressive properties was investigated.The experimental results indicated that polylactic acid with calcium carbonate(PLA+)printed unidirectionally and aligned with the loading direction(0°)exhibits superior tensile and compressive strengths compared to specimens printed bidirectionally at 45/135°.Furthermore,the effect of additives on bioplastics of carbon fiber(PLA-CF)and glass fiber(PLA-GF)additives in PLA-based composites was evaluated in comparison with PLA+specimens.The finding indicated that PLA+has a higher strength-to-cost ratio compared to PLA-CF and PLA-GF.Therefore,unidirectionally printed PLA+was selected as the core material in two geometries:honeycomb and honeycomb lattice.These cores were sandwiched between Glubam panels on the top and bottom surfaces of the structures.Flexural performance was evaluated through four-point bending tests,which revealed that sandwich structures with a honeycomb core achieved a flexural strength-to-weight ratio 56.51%higher than those with a honeycomb lattice core.A parametric study using the finite element model was conducted to evaluate the effect of core scale,cross-sectional depth,Glubamthickness,core depth,and the number of honeycomb elements.The results showed that reducing the Glubam thickness while increasing the 3D-printed core depth significantly improved the flexural performance of honeycomb sandwich structures.Notably,reduced Glubam panel thickness coupled with increased core depth enhanced their flexural performance.
基金Natural Science Fund of Anhui Province (070413138)Key Laboratory Foundation of Anhui Province for Researches on the Conservation and Utilization of Important Biological ResourceKey Laboratory Foundation for Universities and Colleges in Anhui
文摘Recent studies show that a reduced effect of inhibitory transmitter system in the visual cortex may underlie aged visual function degradation. Whether excitatory transmitter system changes with age and hence affects intracortical excitation-inhibition balance is not clear. To explore this issue, we used Nissl staining and immunohistochemical methods as well as Image-Pro Express software to examine the density of Nissl-stained neurons, Glutamie acid-immunoreactive （Glu-IR） neurons and T-Aminobutyric acid-immunoreactive （GABA-IR） neurons in the primary visual cortex of young adult and aged cats. The results showed that there was no significant difference in the density of Nissl-stained neurons between young and old cats （2〉0.05）. However, the density of Glu-IR neurons and GABA-IR neurons in the primary visual cortex of aged cats was significantly lower than that of young ones （P〈0.01）. The ratio between Glu-IR neurons and GABA-IR neurons was significantly increased in old cats compared to that in young adult ones （P〈0.01）. These results indicated that the effect of excitatory transmitter system in the old visual cortex was increased relative to the inhibitory transmitter system, which might cause an imbalance between cortical excitation and inhibition and might be an important factor mediating the visual function decline during aging.
