Effect of oxidized wood flour as functional filler on the mechanical, thermal and flame-retardant properties of polylactide biocomposites

Based on the biodegradable material-polyethylene glycol (PEG)-as the plasticizer, oxidized wood flour (OWF) as the charring agent for polylactide (PLA), a series flame-retardant PLA biocomposites were prepared via melt-compounding and hot-compression. The effect of OWF on the thermal, mechanical and flame retardant properties of biocomposites was investigated systemically. We have found that after the incorporation of PEG and OWF with 10¿wt% into PLA, the biocomposite showed higher tensile elongation than pure PLA. Furthermore, the presence of OWF and ammonium polyphosphate (APP) imparted the biocomposite good flame-retardant performance, shown a remarkable reduction on the peak of heat release rate (PHRR), improved LOI value and passed UL94 V-0 rating. Moreover, Scanning electron microscopy-energy dispersive spectra (SEM/EDS) and thermogravimetric analysis coupled with infrared spectrometer (TG-FTIR) were also performed to understand the flame retardant mechanism. These results proved that OWF could be as new functional filler for polymer composites to further improve their flame retardancy.Peer ReviewedPostprint (published version

Application of improved YOLOv7-based sugarcane stem node recognition algorithm in complex environments

IntroductionSugarcane stem node detection is one of the key functions of a small intelligent sugarcane harvesting robot, but the accuracy of sugarcane stem node detection is severely degraded in complex field environments when the sugarcane is in the shadow of confusing backgrounds and other objects.MethodsTo address the problem of low accuracy of sugarcane arise node detection in complex environments, this paper proposes an improved sugarcane stem node detection model based on YOLOv7. First, the SimAM (A Simple Parameter-Free Attention Module for Convolutional Neural Networks) attention mechanism is added to solve the problem of feature loss due to the loss of image global context information in the convolution process, which improves the detection accuracy of the model in the case of image blurring; Second, the Deformable convolution Network is used to replace some of the traditional convolution layers in the original YOLOv7. Finally, a new bounding box regression loss function WIoU Loss is introduced to solve the problem of unbalanced sample quality, improve the model robustness and generalization ability, and accelerate the convergence speed of the network.ResultsThe experimental results show that the mAP of the improved algorithm model is 94.53% and the F1 value is 92.41, which are 3.43% and 2.21 respectively compared with the YOLOv7 model, and compared with the mAP of the SOTA method which is 94.1%, an improvement of 0.43% is achieved, which effectively improves the detection performance of the target detection model.DiscussionThis study provides a theoretical basis and technical support for the development of a small intelligent sugarcane harvesting robot, and may also provide a reference for the detection of other types of crops in similar environments

<i style="mso-bidi-font-style:normal"><span style="font-size:11.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;mso-ansi-language:EN-GB; mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">Gracilariopsis longissima</span></i><span style="font-size:11.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;mso-ansi-language:EN-GB; mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB"> as biofilter for an Integrated Multi-Trophic aquaculture (IMTA) system with <i style="mso-bidi-font-style: normal">Sciaenops ocellatus</i>: Bioremediation efficiency and production in a recirculating system</span>

528-537A recirculating integrated system producing Sciaenops ocellatus and Gracilariopsis longissima (a red seaweed) was evaluated with respect to nutrient removal efficiency and production. G. longissima was found to be efficient in removing toxic ammonia and maintaining the water quality within an acceptable level for S. ocellatus culture. Specific growth rate (SGR) of S. ocellatus ranged from 0.064 ± 0.006% d-1 to 0.099% ± 0.010% d-1. Survival rates of S. ocellatus were 100% in the Integrated Multi-Trophic Aquaculture (IMTA) systems. <i style="mso-bidi-font-style: normal">G. longissima had average SGRs of 3.03 ± 0.11% d-1, 2.48 ± 0.04% d-1, 1.86 ± 0.26% d-1 and 1.12 ± 0.16% d-1 under initial densities of 1 g L-1, 3 g L-1, 6 g L-1 and 9 g L-1, respectively. Daily average nitrogen and phosphorus uptake rates of G. longissima were negatively correlated to cultivation densities in the recirculating system. Biofiltration capacity of G. longissima was confirmed by significantly reduced concentrations of ammonia, nitrate, nitrite and phosphate in the integrated system with S. ocellatus. Results indicated that G. longissima is suitable as a good candidate for IMTA systems

Effect of oxidized wood flour as functional filler on the mechanical, thermal and flame-retardant properties of polylactide biocomposites

Based on the biodegradable material-polyethylene glycol (PEG)-as the plasticizer, oxidized wood flour (OWF) as the charring agent for polylactide (PLA), a series flame-retardant PLA biocomposites were prepared via melt-compounding and hot-compression. The effect of OWF on the thermal, mechanical and flame retardant properties of biocomposites was investigated systemically. We have found that after the incorporation of PEG and OWF with 10¿wt% into PLA, the biocomposite showed higher tensile elongation than pure PLA. Furthermore, the presence of OWF and ammonium polyphosphate (APP) imparted the biocomposite good flame-retardant performance, shown a remarkable reduction on the peak of heat release rate (PHRR), improved LOI value and passed UL94 V-0 rating. Moreover, Scanning electron microscopy-energy dispersive spectra (SEM/EDS) and thermogravimetric analysis coupled with infrared spectrometer (TG-FTIR) were also performed to understand the flame retardant mechanism. These results proved that OWF could be as new functional filler for polymer composites to further improve their flame retardancy.Peer Reviewe

Characterization of complete chloroplast genome of Ulva torta (Mertens) Trevisan, 1841

Ulva torta (Mertens) Trevisan, 1841 was a global temperate widespread species. Green tide blooms caused by the green algae of the Ulva species occurred frequently in China. As a newly discovered species in the green tide bloom area, it was necessary to explore the relationship between U. torta and other green algae of the Ulva species. The complete chloroplast genome of U. torta was 105,423 bp in size. A total of 100 genes were annotated in the genome, containing 70 protein-coding genes, 27 transfer RNA (tRNA) genes, and three rRNA genes. The chloroplast genome had high AT content (74.76%). Phylogenetic analysis showed U. torta was clustered with Ulva meridionalis. This work could be useful for studying the evolution and genetic diversity of U. torta

The complete mitochondrial genome of a Green macroalgae species: Ulva meridionalis (Ulvales: Ulvaceae)

Ulva meridionalis, a green macroalgae, is one of the causal species for green tides in Japan and spread into the coast of China. During this research, we sequenced the complete mitochondrial genome of U. meridionalis. The mitogenome is 62,887 bp in length, including 28 encoding genes and 29 tRNA genes. Compared with the Ulva species from mitogenome, the gene order and organization of this mitogenome are similar to most of other determined Ulva mitogenomes, with the nucleotide base composition of A 33.6%, T 32.2%, C 16.2%, and G 18.0%. Phylogenetic analysis shows U. meridionalis is closely related to Ulva flexuosa

Multi-objective ant lion optimization for parameter optimization of wireless power transfer systems

The effective transmission distance of a magnetic coupling resonance (MCR) wireless power transfer (WPT) system is an essential index of wireless power transfer. Existing systems often suffer from short transmission distances, low power, and low efficiency. In this paper, a method is proposed for improving the parameters of wireless power transfer systems to enhance the performance of the systems. The main parameters affecting the output power and transmission efficiency are determined by analyzing the MCR WPT system with SS-type topology. In addition, the multi-objective ant lion optimizer is combined with tent chaotic mapping to generate the location information of the initial population by using the distribution and randomness of tent chaotic mapping, which increases the diversity of the people and improves the convergence speed and global search capability of the algorithm to achieve multi-objective parameter optimization, and the optimized model is also analyzed. Experiments show that the optimized MCR WPT system has improved output power and transmission efficiency at a longer distance. The optimal transmission distance of the system is about 0.2 m with a maximum output power of 129.3 W, and the axial offset stability of the system is enhanced. Finally, the effectiveness of the improved model is verified by building a prototype system. It provides a valuable reference for the research of improving wireless power transfer

Complete chloroplast genome of Ulva meridionalis (Ulvales: Ulvaceae): an extremely fast-growing green macroalgae

Ulva meridionalis is one of the causal green macroalgae for green tides in Japan and exists in coastal areas of China. In the present study, complete chloroplast (cp) genome sequence of Ulva meridionalis was reported, and the total length of this species was 88,653 bp (GenBank accession number MN889540). The overall base composition of cp genome was A (37.1%), T (39.0%), C (11.4%) and G (12.5%), similar to other Ulva macroalgae within cp genome, and the percentage of A + T (76.1%) was higher than C + G (23.9%). U. meridionalis cp genome encoded 113 genes, including 80 protein-coding genes, 27 transfer RNAs genes and 6 ribosomal RNAs genes. The maximum likelihood phylogenetic analysis shows that Ulva linza is the closest sister species of U. meridionalis

Vat Photopolymerization of Synthetic Isoprene Rubber Latexes

Isoprene-based elastomers comprise a large percentage of the traditional elastomer market with broad technological impact; however, the challenge of three-dimensional (3D) printing intricate geometries using synthetic isoprene rubbers remains elusive. This manuscript reports synthetic isoprene rubber (SIR) latexes as a precursor for the unprecedented 3D printing of high-molecular-weight isoprene-based elastomers with vat photopolymerization (VP). Dispersed SIR latex particles at 900 nm mitigate entanglement of high-molecular-weight SIR and thus provide low viscosities, which are aligned with viscosity requirements (<10 Pa·s) for VP. The incorporation of reactive monomers, i.e., 1-vinyl-2-pyrrolidone (NVP) and poly(ethylene glycol) diacrylate (PEGDA), into the aqueous phase enables the rapid photopolymerization forming a hydrogel scaffold embedded with SIR particles. Subsequent thermal postprocessing of the photocured hydrogel green bodies promotes SIR particle coalescence through the photogenerated scaffold resulting in a semi-interpenetrating network (sIPN) that exhibits isotropic shrinkage while preserving structural fidelity. Variation in the scaffold concentration tuned the elastomeric properties of the photocured SIR with elongations at break ranging from 94 to 682%. The resulting elastomers exhibit multiphase morphologies and elastomeric properties for a variety of 3D geometric structures