Comparison of the effects of rumen-protected and unprotected L-leucine on fermentation parameters, bacterial composition, and amino acids metabolism in in vitro rumen batch cultures

This study was conducted to compare the effects of rumen-protected (RP-Leu) and unprotected L-leucine (RU-Leu) on the fermentation parameters, bacterial composition, and amino acid metabolism in vitro rumen batch incubation. The 5.00 g RP-Leu or RU-Leu products were incubated in situ in the rumen of four beef cattle (Bos taurus) and removed after 0, 2, 4, 6, 12, 16, and 24 h to determine the rumen protection rate. In in vitro incubation, both RP-Leu and RU-Leu were supplemented 1.5 mmol/bottle (L-leucine HCl), and incubated after 0, 2, 4, 6, 8, 12, and 16 h to measure gas production (GP), nutrient degradability, fermentation parameters, bacterial composition, and amino acids metabolism. Results from both in vitro and in situ experiments confirmed that the rumen protection rate was greater (p < 0.01) in RP-Leu than in RU-Leu, whereas the latter was slow (p < 0.05) degraded within incubation 8 h. Free leucine from RP-Leu and RU-Leu reached a peak at incubation 6 h (p < 0.01). RU-Leu supplementation increased (p < 0.05) gas production, microbial crude protein, branched-chain AAs, propionate and branched-chain VFAs concentrations, and Shannon and Sobs index in comparison to the control and RP-Leu supplementation. RU-Leu and RP-Leu supplementation decreased (p < 0.05) the relative abundance of Bacteroidota, which Firmicutes increased (p < 0.05). Correlation analysis indicated that there are 5 bacteria at the genus level that may be positively correlated with MCP and propionate (p < 0.05). Based on the result, we found that RP-Leu was more stable than RU-Leu in rumen fluid, but RU-Leu also does not exhibit rapid degradation by ruminal microbes for a short time. The RU-Leu was more beneficial in terms of regulating rumen fermentation pattern, microbial crude protein synthesis, and branched-chain VFAs production than RP-Leu in vitro rumen conditions

Numerical Investigation of the Dynamic Performance and Riding Comfort of a Straddle-Type Monorail Subjected to Moving Trains

The driving comfort of a straddle-type monorail, while considering the influence of the bridge structure, was studied on the basis of multibody dynamics and the finite element method. In this study, the coupled vehicle-bridge model was established through SIMPACK and ANSYS; the 3D model of the bridge was established in ANSYS, and the vehicle model with 35 degrees of freedom (DOFs) was established in SIMPACK. The influence of the vehicle speed, pier height, track irregularity, and vehicle load on riding comfort was studied. Overall, straddle-type monorails had a good running stability, and the lateral comfort of the vehicle was better than the vertical comfort, due to symmetrical horizontal wheels. As the vehicle speed increased, the acceleration of the bridge and vehicle increased accordingly. Track irregularity had a substantial influence on riding comfort. Three types of track irregularity were simulated, and this factor should be strictly controlled to be smoother than the Chinese national A-level road roughness. The bridge pier height had a notable influence on the lateral riding comfort. In addition, this study attempted to improve riding comfort from the perspective of increasing the bridge stiffness, which could be achieved by increasing the cross-beam thickness or the track beam height

Bayesian network modeling explorations of strategies on reducing perceived transfer time for urban rail transit service improvement in different seasons

A new Bayesian Network (BN) learning approach is developed in this work to analyze the effect of different factors on the Perceived Transfer Time (PTT) of the Urban Rail Transit (URT) passengers. It is shown that the newly developed approach is able to build a BN with a satisfactory ability to assess effective strategies on reducing the PTT for the URT service improvement. Moreover, it is found that mainly determined by the weather, the relative environment inside an URT station plays the key role in deciding the impacts of varied factors on the PTT in different seasons. Fully illuminating the transfer passageway and preparing adequate and clear transfer guidance in an URT station are the most important in spring for the reduction of the PTT. Effectively decreasing the passenger flow conflicts in an URT station is the only way to evidently reduce the PTT in summer. Not only fully illuminated and well decorated transfer passageway but also increased train service frequency is indispensable to the decrease of the PTT in autumn. Besides minimizing the passenger flow conflicts, improving both frequency and time coordination of train services is essential for reducing the PTT in winter as well

Numerical Investigation of the Characteristics of the Dynamic Load Allowance in a Concrete-Filled Steel Tube Arch Bridge Subjected to Moving Vehicles

Dynamic load allowance (DLA) is a key factor for evaluating the structural condition of bridges; however, insufficient research has been performed regarding the characteristics of DLA in concrete-filled steel tube (CFST) arch bridges. To address this issue, based on an actual CFST arch bridge, the DLA characteristics of bridges are investigated numerically in this study. First, aiming at different structural components, such as the arch rib, main girder, and suspenders, the DLA values obtained at various locations of different structural components are compared in detail, and then the changing regulations of the DLA, considering the influence of different vehicle speeds and various extents of pavement roughness, are summarized and analyzed. Additionally, the relationship between the different DLAs obtained by using the different response indices, that is, displacement, bending moment, and axis force of structure, is investigated. Finally, some conclusions that are significantly beneficial for evaluating or detecting the condition of CFST arch bridges are drawn

Investigation of Traffic Loading Effects for Different Codes on Medium- and Small-Span Girder Bridges in China

With increasing traffic volume, the traffic load grade given by design codes has gradually increased. For new bridges, there is no problem, and the traffic load can be met through the requirements of the new code. However, for existing bridges, there is a lack of uniform standards on whether they can continue to be used. It is not clear whether these bridges will be judged according to the new code or the original design code. The traffic loading effects of different codes on medium- and small-span girder bridges in China are investigated in this study. Three codes are introduced: JTJ 021-89, JTG D60-2004, and JTG D60-2015. Simply supported girder bridges and continuous girder bridges are discussed. The traffic loading effects calculated based on JTG D60-2015 are significantly larger than those calculated based on JTJ 021-89. For simply supported girder bridges, most of the differences range from 20% to 40%, and the maximum value is almost larger than 60%. For continuous girder bridges, most of the differences in the positive bending moments are concentrated in the 20%∼40% range, while the differences in the negative bending moments range from 10% to 20%. Therefore, the differences in traffic loading effects calculated based on various codes cannot be ignored in actual bridge engineering. The conclusion in this study can provide a basis for bridge structure evaluation and life prediction

Solving urban electric transit network problem by integrating Pareto artificial fish swarm algorithm and genetic algorithm

This study presents a multi-objective optimization model for the urban electric transit network problem with the aim of simultaneously designing the layout of bus routes, the frequency and the location and size of charging stations by making a tradeoff between two inconsistent objectives from the perspectives of passengers and operators. A Pareto artificial fish swarm algorithm (PAFSA) embedded with the genetic algorithm (GA) is developed to solve the proposed model. The PAFSA is designed to iteratively search for the proper network configuration satisfying two conflicting objectives. During which, the demand assignment with real-time transit information is performed to update the frequency of each newly designed route. The GA embedded into the PAFSA iteratively decides the locations of charging stations and the number of chargers to be installed in each charging station. A case study of the transit network in an urban region of a city in China is implemented, revealing that the proposed approach is able to rationally design a relatively large-scaled transit network with searching for the best fits between two inconsistent objectives

A Parallel Multi-Modal Factorized Bilinear Pooling Fusion Method Based on the Semi-Tensor Product for Emotion Recognition

Multi-modal fusion can exploit complementary information from various modalities and improve the accuracy of prediction or classification tasks. In this paper, we propose a parallel, multi-modal, factorized, bilinear pooling method based on a semi-tensor product (STP) for information fusion in emotion recognition. Initially, we apply the STP to factorize a high-dimensional weight matrix into two low-rank factor matrices without dimension matching constraints. Next, we project the multi-modal features to the low-dimensional matrices and perform multiplication based on the STP to capture the rich interactions between the features. Finally, we utilize an STP-pooling method to reduce the dimensionality to get the final features. This method can achieve the information fusion between modalities of different scales and dimensions and avoids data redundancy due to dimension matching. Experimental verification of the proposed method on the emotion-recognition task using the IEMOCAP and CMU-MOSI datasets showed a significant reduction in storage space and recognition time. The results also validate that the proposed method improves the performance and reduces both the training time and the number of parameters

Controllable growth α-In2Se3 flakes by chemical vapor deposition

Boosting large-scale application of two-dimensional ferroelectric materials as memory transistors has stimulated intensive research interest. Layered α-In2Se3 features strikingly ferroelectric properties, which allows unique opportunities for the engineering of functional ferroelectric devices. However, the large-scale and controllable growth of the α-In2Se3 has remained a challenge due to the complexity of indium-selenium growth phase diagram. Here, we report the controllable growth of α-In2Se3 flakes using the developed confined-space modulated chemical vapor deposition (CVD) method. The α-In2Se3 flakes are preferred to be deposited on the inner surfaces of the confined space while the β-In2Se3 flakes are mainly grown on the outer surfaces of the confined space. In addition, the grown α-In2Se3 flake possesses a large size of ∼ 60 μm, uniform thickness of ∼ 2.8 nm and distinct ferroelectric properties. Our findings offer an effective and easily accessible method for controllable growth of two-dimensional layered materials and hold promise for further insight into the fascinating physical properties and potential practical devices applications of van der Waal crystals