Applied Research最新文献

The emergence of wearable electronics in contemporary lifestyles has spurred the need for smart fabrics capable of harnessing biomechanical energy. In the present study, a flexible polyaniline-doped textile-based triboelectric nanogenerator (PT-TENG) is designed to harvest low-frequency mechanical vibrations and convert them into electricity. For the device fabrication, five different textile fabrics are doped with conducting PANI, which is utilized as the tribopositive material, PVC thin film as the tribonegative material, and Al foil as electrodes. The PT-TENG works in vertical-contact separation mode, devised in arch structure for easy and complete contact between the working layers. Interestingly, the device featuring a PANI-doped silk fabric generated the highest output voltage of 257.68 V and a current of 5.36 μA, respectively. Additionally, the PT-TENG exhibits mechanical durability and electrical stability during continuous 7000 cyclic operations. Furthermore, the PT-TENG showcases practical applications such as charging commercial capacitors, powering green LEDs and smartwatches, and as a self-powered touch sensor. Thus, the PT-TENG offers a facile fabrication process and robustness, highlighting its potential for sustainable energy harvesting in wearable electronics.

A reciprocating hydrogen compressor status monitoring system for predictive maintenance is developed based on HHT (Hilbert−Huang Transform) with multiple functions, strong applicability, and high accuracy to address the problem of difficulty in identifying fault signals and failure to provide advance warning before faults occur in the reciprocating hydrogen compressor state monitoring system. Design framework of monitoring system is confirmed, and function modules are designed based on LabView platform. HHT is applied to monitor the status of reciprocating hydrogen compressor based on LabView platform. A reciprocating hydrogen compressor is selected as research object, status monitoring analysis is carried out. Five working states of reciprocating hydrogen compressor are collected, which conclude normal state, filler malfunction, cross-head malfunction, air valve malfunction, and piston rod malfunction. HHT is carried out for five signals, and results show that HHT marginal spectrum of five signals has different characteristics. Based on comparison results, precision of HHT ranges from 0.757 to 0.784, recall of HHT ranges from 0.738 to 0.766, F1-score of HHT ranges from to 0.788 to 0.804, HHT has better performance than other two methods. Proposed monitoring system designed in this study provides a comprehensive and efficient online monitoring and data analysis solution for reciprocating hydrogen compressors, which can achieve fault prediction of reciprocating hydrogen compressor, reduce failure rate, and effectively improve the reliability of the compressor oil injection system.

Two-dimensional (2D) materials have ignited extensive research across various fields due to their intrinsic structural, electronic, chemical, and mechanical properties, which are markedly different from those of conventional 3D materials. In the fields of electrochemical catalysis and gas sensing, 2D materials can play vital roles by leveraging their superiorities to accelerate interfacial charge transport and surface catalytic reactions. This review summarizes the advantages of 2D materials, including stackability, tunable bandgap, intrinsic atomic structure, flexibility, and large specific surface area. Furthermore, the recent approaches utilizing 2D materials as active catalysts and sensing materials are explored. Finally, the key challenges and prospects of 2D materials in electrochemical catalysis and gas sensing are discussed.

Lactic fermentation is a traditional preservation method that has been pivotal in enhancing the safety and extending the shelf life of various food products particularly where other technologies are not affordable. The present review paper explores the role of lactic fermentation in African Indigenous vegetables, emphasizing its impact on food safety and shelf life extension. The paper systematically examines the biochemical mechanisms of lactic acid bacteria in suppressing pathogenic microorganisms and spoilage organisms, thereby improving the safety and shelf life of these vegetables. Additionally, it briefly addresses how lactic fermentation contributes to the nutritional and sensory qualities of Indigenous vegetables, which are crucial for their marketability. The review further delves into the economic implications of integrating lactic fermentation of African Indigenous vegetables practices into local agricultural and food systems, considering aspects such as cost-effectiveness, market potential, and value addition of African Indigenous vegetables. By synthesizing the current research and practices, the paper highlights the dual benefits of lactic fermentation of African Indigenous vegetables in enhancing food security and creating economic opportunities in Africa. The findings suggest that leveraging traditional fermentation techniques could significantly bolster the shelf life, safety, and economic viability of African Indigenous vegetables, offering a sustainable approach to food preservation and economic development.

The powertrain, as a central source of noise and vibration, is crucial in determining the overall NVH (noise, vibration and harshness) performance of vehicles, necessitating the optimisation of its structural components for improved durability and passenger comfort. This paper investigates the influence of key geometrical parameters—cell thickness, skin thickness and cell length—on the complex frequency modes of honeycomb and square sandwich structures using the Altair OptiStruct solver 2022 and fast Fourier transform analyser. The driven and non-driven ends of a motor casing and a gearbox, represented by honeycomb structures and ribs, were subjected to an evaluation of equivalent radiated power (ERP). The results show that the square structure performs better at higher skin thickness when resisting severe lateral stresses than the honeycomb while being less stiff at higher cell thickness. Notably, smaller cell length had a substantial impact on the modes of the honeycomb structure, whereas larger cell length had an impact on the square structure. Response surface methodology was used to optimise the modal frequencies of both square and honeycomb panels simultaneously. An ideal cell length of 5.88 mm, skin thickness of 1.303 mm and cell thickness of 0.381 mm were found for the honeycomb construction, yielding a composite desirability of 0.981. On the other hand, with a cell length of 5.045 mm, skin thickness of 1.484 mm and cell thickness of 0.331 mm, the square structure achieved a composite desirability of 0.989. It is interesting to note that the driven end casing of the motor casing made more noise with the addition of ribs than the non-driven end and gearbox. But compared to the original powertrain model, adding a honeycomb structure resulted in a noise reduction of about 10%.