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The objectives of this study were (1) to determine the net energy requirements for the maintenance of gestating sows based on indirect calorimetry, and (2) to explore the feasibility of predicting the net energy requirements for the maintenance of gestating sows based on daily heart rate monitoring. In Exp. 1, six Landrace × Yorkshire crossbred reproductive sows with an initial body weight of 229.5 ± 14.9 kg at d 56 of gestation were randomly assigned to six diverse energy feeding levels using a 6 × 6 Latin square design. The experimental diet was formulated using corn, soybean meal, and wheat bran as major ingredients, and the six feeding levels were set as 1.2, 1.4, 1.6, 1.8, 2.0, and 2.2 times metabolizable energy for maintenance (100 kcal ME/kg BW0.75·d−1), respectively. The animal trial lasted for six periods with 9 days per period, encompassing 5 days of adaptation, 3 days of calorimetry in fed state, and 1 day of calorimetry in fasting state. In Exp. 2, six Landrace × Yorkshire crossbred pregnant sows with an initial body weight of 232.5 ± 12.5 kg at d 64 were fed a corn–soybean meal diet. All sows were tested in a respiratory calorimetry chamber for a 4 day calorimetry test. The heat production of the gestation sows was measured every 5 min using indirect calorimetry, and the heart rate of the gestating sows was recorded every minute using a belt-shape monitor. The results showed that the net energy requirements for the maintenance of gestating sows significant increased as the gestational stage progressed (p < 0.05), and a linear regression model revealed the average net energy requirement for the maintenance of gestating sows was 410 kJ/BW0.75 d−1 during late gestation (days 70–110). Moreover, the average heart rate of the gestating sows was 84 bpm, and the mathematical model developed to predict the net energy requirements for the maintenance of gestating sows was NEm(kcal/h)=19901+exp⁡[136−HR(bpm)43]. In conclusion, the average net energy requirement for the maintenance of sows during late gestation was 410 kJ/BW0.75 d−1, and the utilization of the heart rate monitoring method was found to provide a relevant, accurate prediction for the net energy requirements of sows.

The vibration of concrete is a typical concealed construction process, in which mature supervisory methods are lacking. The quality of vibration relies heavily on the subjective experience and sense of responsibility of the vibration operators. For the widely used hand-held concrete vibrators, existing methods for monitoring the quality of vibration primarily focus on the horizontal positioning of the vibrator. Due to the limited measurable range of vibration depth, these methods are inapplicable for monitoring the vibration depth during the vibration of deeper structures such as walls, columns, and large volumes of concrete. This paper makes the initial attempt to address the issue of monitoring concrete vibration depth, presenting a method that broadens the measurable range of depth in vibration monitoring. Inspired by the principles of optical and magnetic scales, this paper introduces a radio frequency identification (RFID) scales positioning system for the real-time monitoring of vibration depth. The proposed RFID scales vibration depth monitoring method theoretically has no upper limit on the measurable vibration depth, rendering it applicable to monitoring vibration depth of any extent. By comparing the positioning accuracy of different RFID scales hardware compositions, the optimal RFID scales hardware composition and the most effective RFID scales positioning algorithm were identified. The feasibility and accuracy of the vibration depth monitoring method based on RFID scales were validated through engineering field application. This method achieves centimeter-level accuracy in monitoring vibration depth, offers a tool for the precise control of vibration depth, and helps avoid potential quality issues in vibration.

Prestressing technology is an effective way to improve the seismic performance of masonry structures such as concrete masonry wall. Therefore, bonded prestressing technology applied to integrated concrete masonry wall (ICMW) was proposed in this study, and a cyclic loading test on specimens with different section types was conducted. It was found that the prestressing technology rendered thinner and denser cracks on the load-bearing component of the specimens, while the failure mode remained unchanged. The prestressing technology increased the initial stiffness of the specimens and accelerated their stiffness degradation. Although the prestressing technology advanced the yield displacement of the specimens, it had a positive influence on the displacement ductility of the specimens. Additionally, the energy dissipation of the specimens increased with the deepening of the damage state, while the influence of the prestressing on the energy dissipation of the specimens decreased with an increased in the drift ratio. Furthermore, the equivalent viscous damping of the specimens with a rectangular and T-shaped section finally converged at 8% and 14%, respectively. Overall, the aforementioned findings indicate that the prestressing technology proposed in this study is a useful method for improving the damage propagation and seismic performance of ICMW, which could be used to construct low-rise masonry structures in the future.