Ball milling (BM) was a commonly used pretreatment method for pyrolysis. However, the lack of standardized BM intensity parameters made quantitative comparisons between BM pretreatment regulated pyrolysis studies difficult, which limited the practical application of BM pretreatment research findings in industrial production. In this study, the intensity of BM pretreatment was quantitatively evaluated by combining high-speed imaging measurements with discrete element method (DEM) analysis, where the kinetic energy dose was introduced as a measurement parameter. The pyrolysis reaction process and product distribution of Pennisetum giganteum (PG) samples were analyzed in combination with the targeted action sites of mechanical energy during the pretreatment process, and the regulatory mechanism of mechanical energy on the pyrolysis process and outcomes of lignocellulose was investigated. The kinetic energy dose-benefit calculation formula was utilized to analyze the benefits of consuming a unit amount of mechanical energy on the pyrolysis at different kinetic energy dose levels. The results showed that during the BM process, changes in certain physicochemical properties (Crystallinity, C-O and C-C bond content, and aromatic groups) occurred only after the kinetic energy dose reached a threshold. For most properties, unit kinetic energy dose benefits decreased with increasing kinetic energy dose. Under the pretreatment conditions specified in this study, a kinetic energy dose (D) of 200-400 kJ/g maximizes the benefit for pyrolysis oil production from PG, thereby providing a quantitative framework for optimizing BM pretreatment.

The milking process is the most labour-intensive activity in dairy farming. Teat cup attachment is the primary challenge in realizing automatic milking. The existing AMS (automatic milking systems) primarily utilize laser/ vision technology for their sensing systems, leading to slow teat sensing process and struggles with attaching teat cups to angled teats. Moreover, current depth sensing technologies fail to achieve real-time, high-accuracy 6D pose estimation (3D position and orientation) for deformable biological targets like cow teats. To address these issues, we first expand the cow udder image dataset and propose an arbitrary-oriented teat detection and target endpoint positioning method based on YOLOv8-obb. The AP (average precision) of the method is 97.82%, the average orientation error is 1.83 degrees, the average positioning error of target endpoint is 2.04 pixels, and the detection time is 11 ms per image. Secondly, based on the morphological characteristics of the teats, combined with the teats rotated bounding boxes and binocular vision, we develop an efficient method for spatial positions and orientations calculation of teats' target endpoints, with an average time consumption of 24.62 ms. Finally, a lightweight automatic teat cup attachment system is built to perform experiments. Among the 25 groups experiments, the average spatial positioning errors of the X, Y, and Z axes are 2.54 mm, 2.08 mm, and 3.90 mm, respectively, while the average spatial orientation errors are 1.16 degrees, 1.28 degrees, and 1.73 degrees, respectively. The average time consumption for the entire process is 116.71 ms. The results prove the feasibility and accuracy of the proposed methods.

The species, quantity, and tree diameter at breast height (DBH) are important indicators for assessing species distribution, individual growth status, and overall health in the forest. The existing tree information collection mainly relies on manual labor, which results in low efficiency and high labor intensity. To address these issues, we propose a method for tree species identification and diameter estimation by combining deep learning algorithms with binocular vision. First, an image acquisition platform is designed and integrated with a weeding machine to capture images during weeding operation. Images of seven types of trees are captured to develop a dataset. Second, a tree species identification model is established based on the YOLOv8n network, achieving 98.5% accuracy, 99.0% recall, and 99.2% mAP. Then, an improved YOLOv8n-seg model is proposed. It simplifies the network by introducing VanillaBlock in the backbone. FasterNet with a CCFM structure is added at the neck to enhance the model's multi-scale expression capability. The mIoU of the improved model is 93.7%. Finally, the improved YOLOv8n-seg model is combined with binocular vision. After obtaining the segmentation mask of the tree, the spatial position of the two measurement points is calculated, allowing for the measurement of tree diameter. Verification experiments show that the average error for tree diameter ranges from 4.40 similar to 6.40 mm, and the proposed error compensation method can reduce diameter errors. This study provides a theoretical foundation and technical support for intelligent collection of tree information.

This study aims to explore the redispersibility of dehydrated nanocellulose with p-toluenesulfonic acid (p-TsOH) fractionated lignin as an eco-friendly and cost-effective capping agent, to cope with the challenge of irreversible agglomeration and thus loss of nanoscale of nanocellulose upon dehydration. The intermixing of nanocellulose and p-TsOH fractionated lignin was achieved using an aqueous ethanol solution as the medium and films of lignin-blending cellulose nanofibers (L + CNF) with excellent redispersing properties were obtained after facile air-drying. With 0.02 % ammonia as the dispersing solution, the dehydrated L + CNF film was able to achieve nearly 100 % redispersion yield after 30 min of mechanical agitation. If necessary, lignin in redispersed L + CNF can be removed by simple ethanol washing and centrifugation. In addition, redispersed L + CNF can be hybridized with poly(vinyl alcohol) (PVA) in a simple process to prepare PVA nanocomposite films with excellent hydrophobic, thermally stable, antibacterial, and mechanical properties. This study provided a sustainable and cost-effective solution to the dehydration/redispersion challenges of nanocellulose.

An innovative two-step process with p-toluenesulfonic acid (p-TsOH) and oxidation treatment was proposed for the efficient preparation of carboxylated nanocellulose from hybrid Pennisetum. Approximately 90 % of lignin was dissolved by p-TsOH acid under the optimal condition (80 degrees C, 20 min). Near-complete delignification (down to 0.5 %) and introduction of carboxylate groups (up to 1.48 mmol/g) could be achieved simultaneously during cellulose oxidation treatments without the requirement for bleaching. However, different oxidation methods expressed different efficiency and sustainability. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) oxidation has higher selectivity for the carboxylation reaction but with detriment to the aquatic environment. Fenton oxidation is more energy-consuming due to the lower carboxylate contents of products (maximum 188 mu mol/g), with the carboxylic groups present as carboxylic acids, but competitive in terms of environmental sustainability, especially when renewable energy sources are available. The nanocelluloses obtained by the two oxidation methods differ in morphology and have different application prospects.

This study explored the application of swelling pretreatment as a solution to the high cost and contamination associated with the process of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation for nanocellulose preparation. The results demonstrated that swelling significantly expanded the fibers while preserving the degree of polymerization (DP) of cellulose (approximately 95 %). The native crystal structure and hydrogen bonding of cellulose were disrupted after swelling, leading to a reduction in crystallinity and crystallite size, and the decrease of bonding energy and content of intermolecular O6-H⋯O3'. The TEMPO-mediated oxidation processes of cellulose fibers with or without swelling were successfully fitted using a consecutive first-order reaction kinetic model. The fitting results indicated that swelling significantly reduced the activation energy of TEMPO-mediated oxidation and enhanced the reaction rate. Among three swelling systems, the NaOH/thiourea/water system exhibited the optimal promotion effect. Consequently, the swelling treatment enables a significant reduction of 30 % in the catalyst dose for the TEMPO-mediated oxidation while preserving a competitive reaction rate, yield, and product performance. Lower catalyst dosage helps to reduce cost and environmental impact, facilitating the industrial application of the TEMPO-mediated oxidation process.

为提高苜蓿播种环节精细度及种子利用率,设计出一种异形型孔式苜蓿排种器.基于排种器工作原理和苜蓿种子形态,进行充种、清种过程受力分析,设计出异形排种型孔;以型孔前侧导种槽角度、后侧倒角角度、侧边倒角角度、排种盘转速为试验因素,以排种单粒率、漏播率和重播率为评价指标,进行离散元仿真试验,建立试验因素与评价指标间的数学模型.通过响应面法对回归方程进行多目标优化,得到最佳排种参数组合:型孔前侧导种槽角度 35°、后侧倒角 31°、侧边倒角 57°和排种盘转速 25r/min 时,排种单粒率 76.23%,漏播率7.60%,重播率 16.17%.选用中苜 4 号苜蓿品种种子进行播种试验台试验验证,结果表明:设计的异形型孔式苜蓿排种器采用"类条播"农艺进行播种,能够提高排种精细度.

Due to the neglect of reactor features which can substantially influence results, there are divergences on whether the decompression step of steam explosion pretreatment affects biomass saccharification and subsequent bioethanol production. An original innovative reactor is presented, which adopts new-designed pilot-operated pneumatic (POP) mode to maximize the effect of decompression, to settle divergences. Based on the reactor, three series of experiments set at 0.5, 1.0, and 1.5 MPa pressure with 0- and 10-min residence times were conducted with wheat straw as feedstock, compositional/structural adaptation, and enzymatic digestibility as targets. Results show that decompression alone improved the porosity of feedstock and led to a maximum increase of 17

Effective separation of lignin is a prerequisite for the high-value application of lignocellulosic biomass. In this work, the delignification of hybrid Pennisetum (Pennisetum americanumxP. purpureum, HP) using environmentally-friendly steam explosion assisted p-toluenesulfonic acid (p-TsOH) treatment was investigated. The enhancement mechanism of steam explosion was studied by structural analysis of lignin separated using a double enzymatic hydrolysis method. The results showed that the p-TsOH delignification process could be successfully simulated by a second-order kinetic model. After steam explosion at logR0= 3.89, the activation energy for lignin p-TsOH extraction decreased by 30%, the extraction capacity increased by 60%, and the fractionation yield of lignin reached 89.21%, enabling rapid and near-complete dissolution of lignin. Characterization of physicochemical properties using BET, GPC, and XRD techniques indicated that the specific surface area of HP dramatically increased after steam explosion (from 0.9 to 5.02 m2 g-1), while the lignin molecular weight significantly decreased. The 2D-HSQC spectra further revealed that various linkages (e.g., beta-O-4, beta-5, and BE) in lignin underwent varying degrees of cleavage after steam explosion, and the depolymerization reaction was dominant. These modifications by steam explosion collectively led to changes in the lignin fractionation process. This work provides a green and efficient method for delignification of HP, which helps to maximize the utilization of HP for biorefinery industries.

This study analyzes the drying of alfalfa using hot air, infrared and combined drying techniques. Different temperatures, radiation heights, radiation power and wind speed are used as control factors, and drying time, color, crude protein and specific energy consumption are used as evaluation indicators. After assigning weights to each indicator, the comprehensive evaluation index is calculated. The comprehensive evaluation index of alfalfa drying after combined drying is between 1.00 and 1.30, which is overall higher than hot air drying and infrared drying. Combined drying technology can effectively improve the efficiency and quality of the alfalfa drying process.

Abstract The physical properties of organic fertilizer particle, including the dimension feature, density, Poisson’s rate, shear modulus, coefficient of restitution, coefficient of static fraction, and coefficient of rolling fraction are vital to the design of the drum and the simulation of its working process. There have been many relative studies on them, but no mature theory and accurate method to measure the coefficient of rolling friction has been developed. Only one method based on the principle of conservation of energy gave some enlightenment on the way to achieve it. The experimental materials included several selected organic fertilizer particle, an angle adjustable frame of rail, and two rails which were made of steel, and organic fertilizer particle respectively. The main testing equipment was the Phantom v9.1 high-speed camera, which was produced by Vision Research. The frame rate used in the experiment was 1 000 fps. According to the results of the experiment, the coefficient of rolling friction of different moisture content organic fertilizer particle against steel, and organic fertilizer particle are known as y = 0.0004𝑥2 − 0.0014𝑥 + 0.0246 𝑅2 = 0.9998 , y = 0.0004𝑥2 − 0.001𝑥 + 0.1521 𝑅2 =0.9983 respectively. The data measured can be used for design drum and simulation analysis.

Dry explosion (DE), a thermal–mechanical method based on explosive power, was introduced for pretreatment of biomass material. The effects of different dehydration combined with DE pretreatments (120, 140, and 160 °C) on color, pore characteristics, crystallinity, and enzymatic hydrolysis of hybrid Pennisetum (HP) were analyzed. The results showed that dewatering press (PD) removed more soluble substrate in HP than oven drying dehydration (OD). The instantaneous explosive decompression of the DE process significantly increased the explosion power density with the increasing severity factor and reached 45.50 MW·m−3 at 160 °C. Moreover, dehydration combined with DE pretreatment broke the pore structure and destructed cellulose crystallization of HP. Also, it improved the cellulose accessibility and the surface exposure of cellulose, which enhanced the enzymatic hydrolysis yield. PD combined with 160 °C DE promoted the reducing sugar yield of HP to 443.0 mg/g and enzymatic hydrolysis to 70.2

HighlightsOats retain better quality under outlet conditions of 100°C to 110°C and 0.169 to 0.172 kg water/kg dry air.Inactivation of POD maintaining the pectin content increases the oats’ hardness.The color-changing is alleviated when higher RH and high-temperature drying.DARE-EM method can evaluate the forage oats’ overall quality.Abstract. Mechanical drying processing influences the quality changing of the materials. To investigate the differences, the qualities of mechanical dried and naturally dried forage oats were evaluated. The changes in dried oats' enzyme activity, color, texture, and nutritional value were analyzed. A combined analysis of the decision alternative ratia evaluation system (DARE) and entropy weight method (EM) were adopted to evaluate the overall qualities of oats. The results showed that the drum drying process performed better than the natural drying process. Compared with natural drying, oat grass can inactivate enzymes such as CAT and POD quickly during drum drying, shorten the time of browning reaction, and further reduce the loss of color and nutrients. Research showed that the dryer's outlet air temperature and relative humidity severely affected the quality of dried oats. The most suitable conditions were the outlet air temperature of 100°C to 110°C and humidity ratio of 0.169 to 0.172 kg water/kg dry air. Under these conditions, the dried oats’ color change was alleviated, and antioxidant enzymes were inactivated. The retention of the plant cell wall and pigment ensured the quality of oat hay. These results can provide the reference for producing high-quality forages. Keywords: Color, DARE-EM, Enzyme activity, Forage oats, Nutrient content, Triple-pass drum drying.

A method of “dry chemical thermomechanical pretreatment” by combining dry explosion with acid-spraying was carried out for Hybrid Pennisetum (HP) to improve energy efficiency and reduce the negative environmental impact. The physicochemical and pyrolysis properties of HP treated by acid-spraying, dry explosion (DE), and acid dry explosion (ADE) methods were analyzed. The results showed that the DE process can efficiently disrupt the complex biomass structure through the removal of hemicellulose, the dissolution and relocation of lignin, and the dissolution of amorphous cellulose. Moreover, the reaction intensity of the DE pretreatment was significantly enhanced with acid-spraying. The higher heating value of HP treated by ADE 210 °C increased from 17.85 to 21.23 MJ/kg, while the pyrolysis activation energy declined from 48.31 to 38.79 kJ/mol. The ADE pretreatment improved fuel properties and pyrolysis characteristics of HP with the bond conversion of C–O to C–C/C = C. This research supplied an effective and eco-friendly method of dry explosion combined with acid-spraying for improving the fuel and pyrolysis properties of lignocellulose biomass for thermochemical applications. This method can resolve the problem of high energy consumption and waste liquid production for industrial application process.

优质牧草是现代畜牧业健康发展的基石,需要对种植、田间管理、收获和加工等各环节进行科学把控.干燥是牧草产后加工的关键环节,显著影响牧草质量和品质变化.为了对我国牧草加工产业发展提供参考和技术支持,本文归纳了现有牧草收获与干燥加工工艺,概述并分析了国内外主要干燥方式下牧草干燥特性和干燥设备研究现状.牧草主要的干燥方式包括自然干燥、热风干燥、高温快速干燥、太阳能干燥等,近年来国内学者对不同干燥方式下牧草干燥特性研究较多,干燥技术逐渐成熟,但与国外牧草干燥机械化生产技术相比,仍存在一定的差距.例如,存在收获、干燥工艺不匹配,干燥设备缺少设计标准,企业规模较小等问题.制定标准化牧草干燥加工工艺,加强牧草联合干燥技术研究,发展特色牧草干燥技术体系,实现牧草干燥设备大型化、智能化、集成化,将是我国牧草机械化干燥加工产业的发展方向.

为改良退化草地,设计了一种多功能草地切根施肥补播复式作业机,可实现切根施肥、切根补播、切根施肥补播不同方式作业,解决了草地土壤坚实度高、残茬根系量大带来的切根阻力大、开沟入土难以及地表起伏不平、多坑洞石砾造成地轮滑移架空带来的播量不均问题,并进行了切根刀具刃口曲线优化和分层交错式覆土开沟装置及基于槽轮长度与转速同步控制的播量控制系统设计.优化得到,初始静态滑切角取40°,静态滑切角与极角的比例系数取—0.1时的正弦指数曲线为切根刀具最优刃口曲线;设计的分层交错式覆土开沟装置,采用破土刀齿破茬-种沟双圆盘开沟器开沟覆土-肥沟双圆盘开沟器压土成沟并覆盖种沟的工艺,实现草地低扰动开沟,田间试验结果表明,该方法能够实现稳定开沟,形成深47.3 mm、宽29.5 mm的肥床与深44.7 mm、宽19.9 mm的种床,且地表破坏率均值为14.2％,利于草地植被保护;设计的基于槽轮长度与转速同步控制的播量控制系统,通过采集机组左、右地轮转速频率信号进行比较,采用较大者控制槽轮转速与槽轮长度,实现播量与机组前进速度同步匹配与调节,Protues电路仿真结果表明,设计系统具备地轮转速频率信号比较、电机转速与地轮转速同步控制和传动比调节功能,有助于提高播量均匀性.本研究可为草地切根施肥补播复式改良机具设计提供参考与理论依据.

Winter-jujube is a kind of fresh fruit in China. After harvest, winter-jujubes require to grade into different categories according to their maturity levels. Mature winter-jujube can be recognized by their red colour. In this study, a winter-jujube grading robot is designed. Moreover, a method combining YOLOv3 algorithm and hand-engineered features is developed to calculate the maturity of winter-jujube. The grading robot is composed of a transmission unit, an image acquisition unit, and an actuator unit. Based on YOLOv3 algorithm, a detection model is trained, and compared with SSD and Faster R-CNN algorithms. When the IoU are 0.7, 0.8, and 0.9, the F1 scores of the model are 100%, 100%, and 93.66%, respectively. The mAP (IoU = 0.50:0.05:0.95) of the model is 94.78%, and the detection time of single image is 0.042 s. The detection model exhibits a high stability under different lighting conditions. In addition, overlapping winter-jujubes in the image can be detected accurately. After image distortion correction and object detection, an image processing flow for spatial positioning, size measurement and maturity calculation for winter-jujubes is designed. Finally, a real-time grading device for winter-jujube is built to perform grading experiments. The maturity grading accuracy is 97.28%, and the average grading time of each winter-jujube is 1.39 s.

Caragana is potentially an alternative biomass feedstock in China. The influences of different torrefaction conditions on the physical characteristics and fuel properties of pellets made from Caragana were investigated. The Caragana pellets were torrefied under the temperature of 225, 250, and 275 °C with the residence time of 10, 15, and 20 min, respectively. The results showed that the density of torrefied pellet reduced by 24.07 to 35.20%. Compression strength decreased to 7.62 N/mm2 for treated pellets under the condition of 275 °C and 20 min with the maximum weight loss of 29.93%, and the higher heating value increased to 20.95~22.93 MJ/kg. The equilibrium moisture content of the torrefied pellets decreased by 46.17% compared with raw materials. The mass yield and energy yield of torrefied pellet were 70.07 to 88.54% and 70.93 to 90.79%, respectively. With the increase of the torrefaction severity, the mechanical and physical properties of the pellets decreased, while the storage performance and fuel properties enhanced. Simultaneously, the torrefaction temperature had more influence on the fuel properties of Caragana pellets than the residence time. The Caragana pellets torrefied at 250 °C for 20 min maintained not only almost the same mechanical and physical properties as the untreated pellets but performed better storage and fuel properties.

为降低切根刀具与土壤的相互作用力和功耗,优化刀轴转速与前进速度的匹配关系,通过土槽试验,得到速比(刀尖点线速度与机组行进速度的比值)分别为16.9、20.7、24.5、28.2、32.0时,不同前进速度(0.5、1、1.4 m/s)与转速(根据速比与前进速度计算得到)组合下的扭矩、比功耗(单位体积功耗)和总功率.分析发现,同一速比下,对应的扭矩变异系数分别为2.4％、5.2％、1.7％、7.5％、3.9％,对应的比功耗变异系数分别为1.0％、3.4％、8.8％、2.7％、2.7％,这表明在速比一定时,扭矩与比功耗同运动参数组合无关,仅由速比决定.因此,建立了速比与扭矩,速比与比功耗,速比、刀轴转速与总功率的数学关系,并通过速比与切土节距的关系,分析了产生上述规律的原因.根据建立的数学关系,在16～32的速比范围内求其极值,得到在速比分别为27.41和26.31时,扭矩和比功耗分别取得最小值90.79 N·m和6369 kJ/m3;在速比为28、转速取最小值200 r·min-1时,总功率取得最小值2362W.速比为26.31时,即比功耗取得最小值时,扭矩和总功率均接近最小值(与最小值分别相差1.2％和4.2％),是草地切根作业适宜速比.