Sea buckthorn (Hippophae rhamnoides) is an important tree species for ecological restoration and the specialty forest-fruit industry in northern China. Its fruits possess high nutritional and economic value; however, harvesting operations still rely predominantly on manual labor because of the small fruit size, short pedicels, dense fruit clustering, thorny branches, and thin skin that is highly susceptible to mechanical damage. These limitations result in low harvesting efficiency and constitute a major bottleneck restricting large-scale industrial development. To systematically clarify these challenges and support the development of effective mechanized solutions, this review summarizes the physical and mechanical properties of sea buckthorn fruits and the agronomic requirements associated with mechanized harvesting. Furthermore, from the perspective of technological evolution, the study analyses the operating principles, research progress, and applicability of the main harvesting methods, including vibration-based harvesting, pneumatic harvesting, pruning-based harvesting, and whole branch-fruit harvesting systems, together with subsequent fruit detachment, cleaning, and sorting operations. The reviewed studies indicate that international research has primarily focused on cultivars suitable for mechanized harvesting, leading to technological approaches centered either on direct field harvesting or on post-harvest processing after whole branch-fruit collection. In China, significant progress has been achieved in optimizing vibration parameters for fruit detachment, developing low-damage cutting and conveying mechanisms, and improving freezing-assisted fruit detachment, cleaning, and sorting technologies. Nevertheless, several major challenges remain, including the limited availability of cultivars and planting systems suitable for mechanization, insufficient integration between agronomic practices and machinery design, and the relatively low level of intelligence and automation of harvesting equipment. Future research should therefore focus on the breeding of mechanization-oriented cultivars, the establishment of standardized cultivation systems, the development of low-damage and high-efficiency harvesting components, and the advancement of integrated intelligent harvesting equipment, thereby supporting technological innovation and the industrial application of mechanized sea buckthorn harvesting in China.
To address the problem of grain residue commonly occurring during the operation of plot wheat breeding harvesters, the CFD-DEM coupling method was employed to investigate the airflow distribution characteristics and material conveying behavior within a pneumatic conveying device. Fan rotational speed, feeding rate, and the curvature radius of the lower conveying pipe were selected as experimental factors for single-factor and response surface experiments. The results showed that all selected factors significantly affected the conveying performance and residue rate. Specifically, the residue rate decreased with increasing fan rotational speed, increased with increasing feeding rate, and decreased as the curvature radius of the lower pipe increased. The response surface analysis indicated that the optimal operating parameters were a fan rotational speed of 2400 r/min, a feeding rate of 0.4 kg/s, and a lower pipe curvature radius of 420 mm, under which the minimum residue rate of 0.021% was achieved.
The relevance of the study stems from the need to substantiate the traction-adhesion and traction-speed characteristics of a new type of mobile power unit designed to perform transport and technological operations involving the aggregation of agricultural machinery coupled with tractors of traction classes 1.4-2. The aim of the work was to experimentally determine the influence of mass and transmission operating modes on the traction force, the drive wheel slip coefficient and the speed of the multifunctional mobile power unit "Avtotraktor". Experimental studies of the machine's traction characteristics on an asphalt concrete surface were conducted for two MEZ mass variants - without additional load and with installed ballast - using statistical methods for data analysis. Based on the research results, regression relationships were established between the slip coefficient and speed of movement as a function of traction force for various transmission operating modes. It was found that ballasting the "Avtotraktor" significantly reduces slip across the entire range of traction forces and enhances the efficiency of the machine's traction potential. Rational ranges for the use of first and second gears have been determined depending on the magnitude of the tractive effort. It has been experimentally confirmed that, under ballast conditions and with the correct selection of transmission operating modes, the "Avtotraktor" meets the requirements for mobile power units of tractive classes 1.4-2. The results obtained can be used in the further improvement of the design of "Avtotraktor"-type mobile power units, as well as to justify their operating modes during transport and technological operations in agricultural production.
The growing interest in functional food products in recent years has encouraged producers and researchers to develop new preservation techniques and processing methods that improve product quality. Vacuum impregnation is one such method, representing a non-thermal and non-destructive technology based on the hydrodynamic mechanism. Recently, it has been increasingly applied in the production of high-value food products through the incorporation of bioactive compounds into the food matrix. This study investigates the influence of vacuum impregnation treatment on the chemical composition of apple slices impregnated with apple juice and aronia berry juice, followed by convective dehydration. The results revealed superior values for the aronia-impregnated samples, characterized by increased contents of mineral compounds, dietary fiber, vitamin C, polyphenols, and anthocyanins compared with the apple juice-impregnated variant, which exhibited a less pronounced effect. The performed analyses confirmed that vacuum impregnation significantly influenced the chemical profile of dehydrated apples and demonstrated that this technique can be successfully used as a strategy for obtaining optimized functional food products.
To promote the application of the discrete element method (DEM) in the research and development of soybean production equipment, reduce development costs, and improve testing efficiency, the contact parameters of soybean seeds in a discrete element environment were calibrated. A discrete element model of soybean seeds was established in EDEM software using a multi-sphere aggregation approach. The coefficient of restitution between soybean seeds and a Q235 steel plate was calibrated to 0.54 using a collision rebound test. The static friction coefficient between soybean seeds and the Q235 steel plate was calibrated to 0.34 through an inclined-plane sliding test, whereas the rolling friction coefficient was calibrated to 0.01 using an inclined-plane rolling test. The angle of repose of soybean seeds was determined to be 31 degrees using the steel-box extraction method. Based on a quadratic regression orthogonal rotational combination design, a regression model describing the relationship between the soybean angle of repose and inter-particle contact parameters was established. The model was optimized through analysis of variance, and the optimal combination of interparticle contact parameters was determined as follows: coefficient of restitution between seeds of 0.65, static friction coefficient between seeds of 0.55, and rolling friction coefficient between seeds of 0.04. Under these parameter conditions, the relative error of the angle of repose between the simulation and bench tests was 0.32%, demonstrating the accuracy of the calibrated contact parameters and the feasibility of the simulation method. The obtained results can provide a reference for selecting soybean seed contact parameters in discrete element simulations.
