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Sapindus mukorossi seeds are commonly drilled and processed into Buddha beads and other craft products. To improve the machining qualities of the micro-drilling of S. mukorossi seeds, the effects of drilling parameters (feed rate, drilling speed, and drill diameter) on the drilling force, hole diameter and hole morphology were found. The mechanism behind these changes was further analyzed. The drilling parameters and machining process for the micro-drilling of S. mukorossi seeds were optimized. Results indicated that each drilling parameter influenced the drilling force and hole-machining quality by affecting the amount of cutting, the working conditions of the drill bit, chip formation, and the generation of drilling heat. Moreover, the feed rate and drill diameter were the main factors that influenced the drilling force, and the drilling speed played a leading role that influenced hole-machining quality. Interestingly, for the drilling of S. mukorossi seeds, a feed rate of 0.03 mm/r, a drilling speed of 6 m/min, and a drill-bit diameter of 0.9 or 1.5 mm resulted in a hole with high accuracy, good hole morphology, and minimal wear on the drill bit. This study facilitates the selection of suitable drilling parameters and processing technology for the micro-drilling of S. mukorossi seeds to improve processing accuracies and qualities, and provides a theoretical basis for the improvement of related drilling processing equipment.

Forest fires have long been a significant global problem. How to reliably accomplish the early warning and real-time monitoring of forest fires has become a pressing issue in order to limit the damage caused by forest fires. A novel technological approach for forest fire monitoring has been made possible by the quick development of wireless sensor network (WSN) technology. Currently, batteries are the primary source of power for WSNs used in forests, but frequent battery replacement will compromise the network for monitoring. As a result, the power supply is the key limit to its application in forest areas. This paper puts forward the thermoelectric conversion based on the Seebeck effect. Its notable feature is to convert heat energy into electric energy through the temperature difference between shallow soil and air. In the process of testing the device, the maximum voltage was 803.36 mV. At the same time, a power management system (PMS) for a thermoelectric conversion device was designed. The main feature of this system is that there is no need for an external control module. In the laboratory test, the minimum input power of this system was 200 mV. When the load resistance was 8 KΩ, the output power was 0.55 mW, and the maximum efficiency could reach 65.38% when the input was 500 mV, which fulfills the requirements of low cost and high reliability, providing a feasible solution for solving the energy limitation problem of WSNs in a forest area.

A friction-driven forestry electric monorail car based on a wheel hub motor is designed with the aim of solving the problems of the low transportation capacity, low running speed, large turning radius, and poor stability of low-slope mountain forestry monorails. The relationships between the minimum turning radius and the steering spring elasticity coefficient, between the body tilt and the anti-tip spring elasticity coefficient, and between the minimum turning radius of the monorail car and the distance between the two chassis and the two steering wheels was provided by the theoretical calculation and analysis of the key parameters of a dual-chassis structure, steering device, and anti-tip device. The dimensional parameters of the key components were determined. The three-dimensional design of the overall car was carried out, and the feasibility of the design was verified in kinematic simulation experiments. A performance test of the monorail car was conducted with the minimum turning radius, maximum load capacity, maximum full load speed, climbing degree, and center of gravity offset as indicators. The test results show that the monorail car has a minimum turning radius of 3.3 m, a maximum load capacity of 300 kg, a maximum speed of 20 km·h−1 fully loaded, a maximum gradient of 21°, and a unilateral vibration amplitude of 8 mm or less. The double-chassis structure and anti-tip device met the design requirements. The good transportation performance of the designed monorail car effectively solves the problems of a large turning radius and unstable driving of current forestry monorails. Additionally, the designed monorail car is environmentally friendly and efficient, meeting the requirements of monorail transporters for low-slope mountain forests and laying the foundation for the intelligent harvesting and transportation of mountain forest fruits.