Water-durability and high-performance all-fiber humidity sensor using methyldiethanolamine-photopolymer-PDMS structure.

In the context of optical fiber humidity sensing, the long-term stability of sensors in high humidity and dew environments such as bathrooms or marine climates remains a challenge, especially since many humidity sensitive materials are water soluble. In this study, we use methyldiethanolamine, pentaerythritol triacrylate and Eosin Y to form a liquid-solid structure humidity sensitive component, the outermost layer is coated with PDMS passivating layer to ensure the stability and durability of the humidity sensor under the conditions of dew and high humidity. The liquid microcavity of the sensor consists of methyldiethanolamine-pentaerythritol triacrylate composite solution, and the sensitivity is several times higher than that of the liquid-free cavity sensor. The sensitivity of the sensor to temperature is verified (0.43 nm/°C and 0.30 nm/°C, respectively) and temperature crosstalk is compensated using a matrix. The compact structure allows for ultra-fast response (602 ms) and recovery time (349 ms). Our work provides a promising platform for efficient and practical humidity and other gas monitoring systems.

Determination of restricted dyes in textile raw material solid wastes by ultra-high performance liquid chromatography-tandem mass spectrometry.

A rapid and highly sensitive method for the quantification of 34 restricted dyes (including acid, basic, disperse, direct, and azo dyes) in solid textile raw material wastes was developed by employing ultrasonic extraction coupled with ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS). More specifically, the proposed method employed methanol as the extraction solvent, while the mobile phases consisted of acetonitrile and 10 mmol/L ammonium acetate + 0.05% ammonia. A good linearity was achieved over the concentration range of 0.01-200 ng/mL with correlation coefficients (R) between 0.991-0.999, limits of detection (LODs) of 0.25-40.0 µg/kg (S/N = 3) and limits of quantification (LOQs) of 0.84-133.4 µg/kg (S/N = 10). 34 dyes were recovered at three levels ranging from 84.5 to 106.9% with relative standard deviation (RSDs) ranging from 0.59% to 10.61%. Further, the method was applied for the accurate analysis of 32 counts of cotton yarn, waste cotton, and printed fabrics within 15 min. The dyestuffs accurately quantified by this rapid chromatographic procedure covered a wide range of carcinogenic and allergenic dyestuffs listed in the Oeko-Tex Standard 100 (version 02.2023) colourants. The ultrasound technique combined with the ultra-high performance liquid chromatography-tandem mass spectrometry method proposed in this work is thus suitable for the rapid screening, confirmation, and quantitative detection of industrial synthetic dyes within solid waste originating from textile raw materials.

Bionic Design and Optimization on the Flow Channel of a Legged Robot Joint Hydraulic Drive Unit Based on Additive Manufacturing.

The joint hydraulic drive unit (HDU) serves as a pivotal element in enabling the high-performance movements of legged robots. Functioning as the conduit linking the oil source and the actuator, the hydraulic flow channel significantly impacts actuator performance. Hence, optimizing the HDU flow channel becomes imperative, enhancing not only HDU efficiency but also the overall system performance. This paper introduces a novel approach by aligning the hydraulic flow channel of the joint HDU with the arteriovenous layout of the cardiac vascular system, departing from the conventional machining flow channel model. Through simulations determining the optimal range of the vascular branch radius and angle, this study guides the design optimization of the joint HDU flow channel. With the primary optimization goal of reducing pressure loss, the study compares simulation outcomes of various flow channel models-linear, variable excessive radius, and the multidimensional Bessel curve-tailored to suit the arrangement specifics of the joint HDU. Further validating these designs, the flow channels are fabricated using additive manufacturing for experimental verification. The integration of simulation analyses and pressure loss testing reveals a remarkable reduction of over 40% in pressure loss for the bionic flow channel compared to the conventional machining form. This empirical evidence strongly substantiates the bionic flow channel's superior efficacy in pressure loss reduction. The findings presented herein offer valuable insights for the development of low-loss flow channels in joint HDUs, thereby presenting a new avenue for designing energy-efficient, high power-to-weight ratio legged robots.

Evaluation of the freshness of rainbow trout (Oncorhynchus mykiss) fillets by the NIR, E-nose and SPME-GC-MS.

A comparison study on the freshness of rainbow trout (Oncorhynchus mykiss) fillets in the course of their sale was performed using near-infrared spectroscopy (NIRS), solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS), and the electronic nose (E-nose) technique. Quantitative analysis of the volatile salt nitrogen (TVB-N) of rainbow trout fillets with different freshness using NIR combined with the partial least squares (PLS) method revealed that the predicted values of TVB-N of the samples were significantly correlated with the true values (P < 0.01). SPME-GC-MS combined with E-nose analysis demonstrated that there were significant differences in the volatile flavor components of rainbow trout fillets at different freshness, and E-nose combined with principal component analysis (PCA) and linear discriminant analysis (LDA) could achieve rapid and non-destructive freshness ranking of rainbow trout fillets based on volatile flavor characteristics. Consequently, the NIRS and E-nose non-destructive testing techniques are capable of acting as rapid screening tools for detecting the freshness of rainbow trout fillets during their sale.