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In this study, an optimized composite was prepared based on chemically modified corn straw, chitosan, and poly(lactic acid) using Response Surface Methodology (RSM). The composite was produced by screw extruding and hot pressing. The Box Behnken Design (BBD) software was used to design the test to optimize the composite composition. The optimum ratio of 3 factors, e.g. chemically modified corn straw (0.10 to 0.40 g), chitosan (0.25 to 0.75 g), and poly(lactic acid) (2.00 to 3.00 g) on the response value (bending strength) of the composite was investigated. RSM-BBD provided the optimum combination of composites. The novel composite prepared under the optimized factors was characterized by Fourier transform infrared spectroscopy, mechanical testing, water absorption tests, contact angle tests, and scanning electron microscopy. The results showed that the mechanical strength, e.g., bending strength, impact strength, and tensile strength of chemically modified corn straw based composite were 21.6 MPa, 4.43 kJ/m2, and 20.0 MPa, respectively, which increased by 23.5%, 13.9%, and 18.7% compared to native corn straw based composite. Improved mechanical strength and hydrophobicity for chemically modified corn straw/chitosan/poly(lactic acid) demonstrated that chemically modified biomass fibers and bio-based degradable polymers have the potential to produce environmentally friendly composites.

A new class of bio-composites was developed by utilizing four kinds of lignocellulosic biomass fiber (bagasse, bamboo, rice husk, and rice straw) as filling fibers. Poly-β-hydroxybutyrate (PHB) and poly(butylene succinate) (PBS) in a mixture ratio of 7:3 were used as matrix materials with hot-press molding. The performance of the resulting composites was evaluated by compositional analyses, mechanical analysis, Fourier transform infrared (FTIR) spectroscopy, thermogravimetry, and morphological analysis. The interfacial adhesion, thermal stability, and comprehensive mechanical properties of the alkali treated bamboo/PHB/PBS composite were highest among the four bio-composites. The bending strength, tensile strength, and impact strength for alkali treated bamboo/PHB/PBS composite was 19.82 MPa, 12.97 MPa, and 4.30 kJ/m2, respectively. The thermal stability for NaOH modified bamboo/PHB/PBS composite was slightly superior to the other three composites, with the initial pyrolysis temperature of 248 °C, moderate pyrolysis speed, and the amount of pyrolysis residue (5.81%). The results showed the suitability of biomass fiber and biodegradable polymer for producing environmentally friendly composite materials.

Alkali-treated bagasse fiber was used as a process variable for optimization of the properties of polybutylene succinate/poly(lactic acid)-based biocomposites using Box-Behnken design (BBD) and response surface methodology (RSM). The optimum conditions for three factors, i.e., NaOH-treated bagasse fiber (0.55 to 1.65 g), polybutylene succinate (1.1 to 2.3 g), and poly(lactic acid) (2.2 to 3.4 g) on the bending strength of biocomposite were investigated. The optimum combination was 0.91 g of NaOH-treated bagasse fiber, 1.14 g of polybutylene succinate, and 3.10 g of poly(lactic acid). The bending strength for NaOH-treated bagasse fiber/polybutylene succinate/ poly(lactic acid) composite was 27.0 MPa, which was 26.0% higher than native bagasse fiber-based composite. The composites were also characterized by thermogravimetric analysis, mechanical testing, Fourier transform infrared, scanning electron microscopy, water absorption, and contact angle tests. Results demonstrated that the bending strength, impact strength, and tensile strength of alkali treated bagasse fiber-based biocomposite increased by 26.0%, 15.5%, and 23.3%, separately, compared with native bagasse-based composite after sequential homogenization, compounding, and hot pressing. The hydrophobicity for alkali-treated bagasse fiber/PBS/PLA was also improved. Thus, NaOH-treated biomass materials/biodegradable polymer was judged to be suitable for preparing green composite materials.

The objective of this research was to prepare an optimized bio-composite for packaging based on alkali-treated banana pseudo-stem fiber (BPSF), PBAT, and PLA using response surface methodology (RSM). The effects of three factors, i.e., alkali-treated BPSF (0.8 to 2.4 g), PBAT (0.75 to 2.25 g), and PLA (1.6 to 3.2 g) on two dependent variables, i.e., bending strength and tensile strength of bio-composite, were investigated. Box-Behnken design (BBD) provided the combination for an optimum composite, which was 1.15 g of alkali-treated BPSF, 2.09 g of PBAT, and 2.66 g of PLA, respectively. The bending strength and tensile strength for alkali-treated BPSF/PBAT/PLA composite were 32.62 MPa and 30.91 MPa, which was 20.50% and 16.51% higher than native BPSF/PBAT/PLA composite. The bio-composite prepared using the optimized results was further characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetry, scanning electron microscopy (SEM), mechanical testing, contact angles, and water absorption tests. Analyses showed that alkali-treatment could improve the adhesion and compatibility of BPSF in the polymer matrix. These outcomes were associated with the use of treated-BPSF for better mechanical strength and lower hygroscopicity. This result demonstrated that alkali-treated agricultural residue and degradable polymer could be used to prepare composite materials for green packaging application.

Water body mapping is an effective way to monitor dynamic changes in surface water, which is of great significance for water resource management. Super-resolution mapping is a valid method to generate high-resolution dynamic water body maps from low-spatial-resolution images. However, the accuracy of existing super-resolution mapping methods is not high due to the low accuracy of fraction images and the insufficiency of spatial pattern information. To solve this problem, this paper proposes a spectral similarity scale-based multiple-endmember spectral mixture analysis (SSS-based MESMA) and a multiscale spatio-temporal dependence method based on super-resolution mapping (MESMA_MST_SRM) for water bodies. SSS-based MESMA allows different coarse pixels to have different endmember combinations, which can effectively improve the accuracy of spectral unmixing and then improve the accuracy of fraction images. Multiscale spatio-temporal dependence adopts both pixel-based and subpixel-based spatial dependence. In this study, eight different types of water body mappings derived from the Landsat 8 Operational Land Imager (OLI) and Google Earth images were employed to test the performance of the MESMA_MST_SRM method. The results of the eight experiments showed that compared with the other four tested methods, the overall accuracy (OA) value, as well as the overall distribution and detailed information of the water map generated by the MESMA_MST_SRM method, were the best, indicating the great potential and efficiency of the proposed method in water body mapping.

Pose estimation is a particularly important link in the task of robotic bin-picking. Its purpose is to obtain the 6D pose (3D position and 3D posture) of the target object. In real bin-picking scenarios, noise, overlap, and occlusion affect accuracy of pose estimation and lead to failure in robot grasping. In this paper, a new point-pair feature (PPF) descriptor is proposed, in which curvature information of point-pairs is introduced to strengthen feature description, and improves the point cloud matching rate. The proposed method also introduces an effective point cloud preprocessing, which extracts candidate targets in complex scenarios, and, thus, improves the overall computational efficiency. By combining with the curvature distribution, a weighted voting scheme is presented to further improve the accuracy of pose estimation. The experimental results performed on public data set and real scenarios show that the accuracy of the proposed method is much higher than that of the existing PPF method, and it is more efficient than the PPF method. The proposed method can be used for robotic bin-picking in real industrial scenarios.

In this paper, the NaOH pretreatment of banana pseudo-stem fiber for biogas production was investigated using a statistically designed set of experiments. A central composite design was used to identify the optimum pretreatment condition for four factors, i.e., NaOH concentration, pretreatment temperature, pretreatment time, and fiber length, on biogas fermentation of banana pseudo-stem fiber. The best pretreatment condition was 7.8% NaOH, 0.2-cm fiber length, and a temperature of 48 °C for 3 days. NaOH pretreatment increased the biogas yield of banana pseudo-stem fiber. The highest biogas yield was 463.0 mL•g-1VSadded, which was 89.2% higher than that of the control, at 244.7 mL•g-1VSadded.

Ethanol production from NaOH-Pretreated solid state fermented sweet sorghum bagasse with an engineered strain of Z. mobilis TSH-ZM-01 was optimized. Results showed that: (1) residual solid removal during ethanol fermentation was unnecessary and 24 h fermentation duration was optimal for ethanol production; (2) ethanol yield of 179.20 g/kg of solid state fermented sweet sorghum bagasse achieved under the optimized process conditions of cellulase loading of 0.04 g/g-glucan, xylanase loading of 0.01 g/g-xylan, liquid to solid ratio of 9:1 and pre-hydrolysis duration for 72 h.

Precipitation of lignosulphonates from the liquor for sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) by addition of Ca(OH)2 was investigated in this work. The experiment was conducted in a reaction temperature range of 20 to 75oC for 90 minutes with Ca(OH)2 charge varying from 20 to 90 g/L and a range of liquid enrichment ratio of 1 to 5. It was found that increased Ca(OH)2 charge, duration time, reaction temperature, and liquor concentration each tended to improve lignosulphonates precipitation, but tended to hurt fermentable sugars conservation. Application of Ca(OH)2 20 g/L to SPORL liquid without enrichment at 30oC for 90 minutes could be an optimal condition. Under this condition, 25.95% of the lignosulphonates was precipitated for further utilization, while calculated amounts of 106.46% of glucose and 60.25% of xylose were conserved for further fermentation.

The objective of this research was to prepare an optimized bio-composite for packaging based on alkali-treated banana pseudo-stem fiber (BPSF), PBAT, and PLA using response surface methodology (RSM). The effects of three factors, i.e., alkali-treated BPSF (0.8 to 2.4 g), PBAT (0.75 to 2.25 g), and PLA (1.6 to 3.2 g) on two dependent variables, i.e., bending strength and tensile strength of bio-composite, were investigated. Box-Behnken design (BBD) provided the combination for an optimum composite, which was 1.15 g of alkali-treated BPSF, 2.09 g of PBAT, and 2.66 g of PLA, respectively. The bending strength and tensile strength for alkali-treated BPSF/PBAT/PLA composite were 32.62 MPa and 30.91 MPa, which was 20.50% and 16.51% higher than native BPSF/PBAT/PLA composite. The bio-composite prepared using the optimized results was further characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetry, scanning electron microscopy (SEM), mechanical testing, contact angles, and water absorption tests. Analyses showed that alkali-treatment could improve the adhesion and compatibility of BPSF in the polymer matrix. These outcomes were associated with the use of treated-BPSF for better mechanical strength and lower hygroscopicity. This result demonstrated that alkali-treated agricultural residue and degradable polymer could be used to prepare composite materials for green packaging application. [ABSTRACT FROM AUTHOR]

Background The bioconversion of cellulose into simple sugars or chemicals has attracted extensive attention in recent decades. The crystal allomorphs of cellulose are key factor affecting cellulose saccharification. However, due to the influence of lignin, hemicelluloses, and different characterization methods in the literature, the effect of cellulose allomorphs on cellulose saccharification is still unresolved. Thus, a systematic research on the effect of different cellulose allomorphs on enzymatic saccharification was required. Results Multiple approaches, including the use of ionic liquid (IL), ethylenediamine (EDA), glycerol, and sodium hydroxide, were used to pretreat α-cellulose in this work. The properties of the obtained cellulose (crystallinity, lattice spacing, specific surface area, and ettability) were characterized by X-ray diffraction, Brunauer, Emmett, and Teller (BET) specific surface area analysis, and water contact angle analysis, respectively. The distance of the lattice spacing of cellulose III was longer than that of other cellulose samples. The crystallinity and water contact angles of the cellulose samples were ranked in the following order: cellulose treated with IL < cellulose treated with NaOH < cellulose treated with EDA < cellulose without treatment < cellulose treated with glycerol. Cellulose treated with IL, with a crystallinity index value of 20%, was very close to amorphous cellulose. After 72 h hydrolysis, the cellulose conversion ratio ranged from 43% to 99%. Cellulose treated with IL exhibited the best hydrolysis profile, followed by cellulose treated with EDA. Conclusion Ionic liquid pretreatment significantly altered the ultrastructure and morphology of cellulose samples, making cellulose much easier for enzymes to digest due to its significantly high amorphous content. However, when the impact of amorphous content was not considered, the allomorph easiest for enzymes to digest was cellulose III, followed by cellulose II, cellulose Iα, and cellulose Iβ. When the cellulose crystallinity index was similar, the allomorph type was the dominant factor. The amorphous content had a strong positive influence on cellulose digestibility. Water contact angle was also an important factor in evaluating the enzymatic hydrolysis efficiency of cellulose except for cellulose III. A high wettability of cellulose enhanced the enzymatic hydrolysis when the crystal allomorph of all the cellulosic samples was the same. [ABSTRACT FROM AUTHOR]

Background Sweet sorghum is regarded as a very promising energy crop for ethanol production because it not only supplies grains and sugar, but also offers lignocellulosic resource. Cost-competitive ethanol production requires bioconversion of all carbohydrates in stalks including of both sucrose and lignocellulose hydrolyzed into fermentable sugars. However, it is still a main challenge to reduce ethanol production cost and improve feasibility of industrial application. An integration of the different operations within the whole process is a potential solution. Results An integrated process combined advanced solid-state fermentation technology (ASSF) and alkaline pretreatment was presented in this work. Soluble sugars in sweet sorghum stalks were firstly converted into ethanol by ASSF using crushed stalks directly. Then, the operation combining ethanol distillation and alkaline pretreatment was performed in one distillationreactor simultaneously. The corresponding investigation indicated that the addition of alkali did not affect the ethanol recovery. The effect of three alkalis, NaOH, KOH and Ca(OH)2 on pretreatment were investigated. The results indicated the delignification of lignocellulose by NaOH and KOH was more significant than that by Ca(OH)2, and the highest removal of xylan was caused by NaOH. Moreover, an optimized alkali loading of 10% (w/w DM) NaOH was determined. Under this favorable pretreatment condition, enzymatic hydrolysis of sweet sorghum bagasse following pretreatment was investigated. 92.0% of glucan and 53.3% of xylan conversion were obtained at enzyme loading of 10 FPU/g glucan. The fermentation of hydrolyzed slurry was performed using an engineered stain, Zymomonas mobilis TSH-01. A mass balance of the overall process was calculated, and 91.9 kg was achieved from one tonne of fresh sweet sorghum stalk. Conclusions A low energy-consumption integrated technology for ethanol production from sweet sorghum stalks was presented in this work. Energy consumption for raw materials preparation and pretreatment were reduced or avoided in our process. Based on this technology, the recalcitrance of lignocellulose was destructed via a cost-efficient process and all sugars in sweet sorghum stalks lignocellulose were hydrolysed into fermentable sugars. Bioconversion of fermentable sugars released from sweet sorghum bagasse into different products except ethanol, such as butanol, biogas, and chemicals was feasible to operate under low energy-consumption conditions. [ABSTRACT FROM AUTHOR]