Search Results (34)

Dredged sludge usually has high water content and poor engineering properties, which would be unfavorable for its rapid resource utilization. Meanwhile, straw fiber is an environmentally friendly material for improving the mechanical behavior of soil. In this research, a series of shrinkage tests were conducted to investigate the straw fiber effects on the shrinkage behavior of dredged sludge with high water content. Four initial water contents and straw fiber amounts were designed. The water content and crack development were recorded throughout the test. According to the test results, a reduction in water content regarding drying time can be divided into three stages: the constant-rate stage, the falling-rate stage, and the residual stage. At the falling-rate stage, water evaporation is affected significantly by straw fiber. Compared with the sample without straw fiber, the influence of straw fiber on the water evaporation of dredged sludge depends upon the initial water content and the straw fiber content. The straw fiber shows an overall inhibitory effect on the initiation and development of cracks for the tested samples. Moreover, the influence of straw fiber on the shrinkage behavior of dredged sludge depends upon the initial water content and fiber content. Full article

The development of information technologies has been exponentially applied to the architecture, engineering, and construction (AEC) industries. The extent of the literature reveals that the two most pertinent technologies are building information modeling (BIM) and artificial intelligence (AI) technologies. The radical digitization of the AEC industry, enabled by BIM and AI, has contributed to the emergence of “smart cities”, which uses information technology to improve urban operational and sustainable efficiency. Few studies have investigated the roles of AI and BIM in AEC from the perspective of sustainable buildings in assisting designers to make sustainable decisions at building and city levels. Therefore, the purpose of this paper is to explore the research status and future development trends in the relationship between AI and BIM-aided sustainable building in the context of the smart city to provide researchers, designers, and technology developers with potential research directions. This paper adopted a macro and micro bibliographic method, which is used to map out the general research landscape. This is followed by a more in-depth analysis of the fields of sustainable design, sustainable construction, sustainable development, and life cycle assessment (LCA). The results show that the combination of AI and BIM helps to make optimal decisions on materials, cost, energy, construction scheduling, and monitoring and promotes the development of sustainable buildings in both technical and human aspects so to achieve Sustainable Development Goals 7 (ensuring access to affordable, reliable, and sustainable modern energy for all), 9 (building resilient infrastructure, promote inclusive and sustainable industries, and foster innovation), 11 (building inclusive, safe, risk-resilient, and sustainable cities and human settlements), and 12 (ensuring sustainable consumption and production patterns). In addition, the combination of AI, BIM, and LCA technologies offers great potential to improve building performance, and the future development of AI and BIM integration should not only consider the sustainability of buildings but also consider the human-centered design concept and the health, safety, and comfort of stakeholders as one of the goals to realize the multidimensional development of smart city based on city information model. Full article

Bolted connections are a common feature of connection in mechanical structures, employed to secure connected parts by tightening nuts and providing preload. The preload is susceptible to various factors leading to potential bolt loosening. The acoustoelastic theory is the most common measure of a bolt structure’s stress. The present study investigates the relationship between the inherent properties of a structure and its acousticelastic properties. The modal response of the bolted structure under different preload forces is studied by translating the acoustoelastic relationship of the structure into an analysis of its intrinsic properties. The modal analysis reflects the relative change in wave velocity to be determined implicitly based on the eigenfrequencies of the structure. A frequency formulation of classical bolted structures based on acoustoelastic theory is presented in this paper to conduct the intrinsic characteristic analysis of bolted structures. The COMSOL5.4 simulation results are under the acoustic elasticity coefficients for ultrasonic wave propagation in bolt structures, as predicted by the acoustic elasticity theory, and the present solutions are compared with those available in the literature to confirm their validity. A systematic parameter study for bolted structures under the varying preloads with different material parameters, Lame elastic constants, Murnaghan third-order elastic constants, and structural parameters are presented. These results may serve as a benchmark for researchers in this field. Full article

This study analyzed the effects of airflow characteristics on the temperature distribution and drying uniformity of paddy during convective drying. Simulations of the drying process with varying airflow inlet and outlet positions were conducted using COMSOL Multiphysics 6.1 software. The determination coefficient (R²) between the simulated data and experimental values of Sample1 (S1), Sample2 (S2), and Sample3 (S3) was calculated, and its average values were 0.964, 0.963, 0.963, and 0.967, respectively. This study demonstrates that the airflow direction and outlet location have a significant impact on the temperature uniformity of the paddy. The vortex structure generated by the obstruction of the sidewalls and paddy influences both the airflow and temperature distribution within the drying chamber. When the outlet was on the left side and the inlet airflow was in a vertical orientation (VO), the temperature distribution of the paddy exhibited higher temperatures in the edge regions and lower temperatures in the center, with a maximum temperature difference of around 16 °C. The time required for the temperature to reach equilibrium with the outlet positioned on the left was 28.6% shorter than with the outlets positioned in the center or on both sides. Moreover, the temperature uniformity of the three paddy samples was better under this condition. The developed model accurately reflected the paddy drying process. It could also be used to analyze the optimal heating uniformity, providing a technical basis for the design of grain dryers. Full article

This paper introduces a multi-objective optimization problem (MPO) for the forming process parameters of disc forgings using grey relational analysis (GRA) and the response surface methodology (RSM). Firstly, an experimental design based on the Box–Behnken design (BBD) principle was established, and simulations were performed in Deform to obtain response data. Secondly, GRA was used to transform the MPO into a grey relational degree (GRD) problem, and the entropic weight method was integrated to ascertain the influence weights of each variable on GRD. Then, a quadratic polynomial prediction model based on the RSM was constructed, and its accuracy was ensured through model validation. Finally, the optimal process parameter combination was determined through the particle swarm optimization algorithm, which included a friction coefficient of 0.3, an initial temperature of 1250 °C, and a downward pressing speed of 7.5 mm/s. The results of the experimental investigation indicate that optimized process parameters significantly reduce the forming load, equivalent stress, and damage value, effectively enhancing the overall quality of forged parts. Full article

The current literature analyzing the dynamic response of coupled pipelines neglects the crucial interplay between the pipelines themselves and these constraints. This overlooked interaction has substantial influence on the fluid–structure coupling response, particularly in scenarios involving continuous constraints. We focus on a piping system surrounded by compacted soil, which is regarded as unbounded homogeneous elastic soil that suffers from water hammer. This study established a one-dimensional model for water pipe-embedded compacted soil with fluid–structure–soil interaction. Taking fluid–structure–soil interaction into account, fluid–structure interactions (FSIs) include Poisson coupling, junction coupling emerging at the fluid–structure interface, and pipe–soil coupling (PSC) emerging at the pipe–soil interface. In this study, as soil is assumed to be a homogeneous, isotropic elastic material, the coupling responses are more complex than those of an exposed pipe, and the relevant mechanisms justify further exploration to obtain well-predicted results. To mathematically describe this system considering fluid–structure–soil interaction, the four-equation FSI model was modified to accommodate the piping system surrounded by unbounded homogeneous elastic soil, employing the finite volume method (FVM) as a means to tackle and solve the dynamic problems with FSI and PSC, which partitions the computational domain into a finite number of control volumes and discretizes governing equations within each volume. The results were validated by the experimental and numerical results. Then, dynamic FSI responses to water hammer were studied in a reservoir–pipe–reservoir physical system. The hydraulic pressure, pipe wall stress, and axial motion were discussed with respect to different parameters. With the PSC and FSI taken into account, fluid, soil, and pipe signals were obviously observed. The results revealed the structural and fluid modes. Dynamic responses have been proven to be difficult to understand and predict. Despite this, this study provides a tractable method to capture more accurate systematic characteristics of a water pipe embedded in soil. Full article

The NR2F family, including NR2F1, NR2F2, and NR2F6, belongs to the nuclear receptor superfamily. NR2F family members function as transcription factors and play essential roles in the development of multiple organs or tissues in mammals, including the central nervous system, veins and arteries, kidneys, uterus, and vasculature. In the central nervous system, NR2F1/2 coordinate with each other to regulate the development of specific brain subregions or cell types. In addition, NR2F family members are associated with various cancers, such as prostate cancer, breast cancer, and esophageal cancer. Nonetheless, the roles of the NR2F family in the development and diseases of the lung have not been systematically summarized. In this review, we mainly focus on the lung, including recent findings regarding the roles of the NR2F family in development, physiological function, and cancer. Full article

The Supreme Deity Talismans of XuHuo, as the mysterious visual artforms in Daoism, are significant ritual images created by Daoists during the Song and Yuan dynasties. This article explores the creation process of the SDTXH by applying psychoanalytic theory to analyze the literature related to their drawings in Daozang. The ritualistic concentration involved in writing the SDTXH resembles Jung’s systematic exercises aimed at eliminating critical attention, thus creating a vacuum in conscious. This vacuum serves as the key premise for active imagination, through which the unconscious is integrated into the conscious. Fuqiao, in fact, is a symbol dynamically depicting the process of the unconscious being inseminated by the conscious through immersion within it. This integration, or unity, represents the embodiment of concepts such as “mandala”, Guizhong, and Taiji. The SDTXH originate from Guizhong and essentially serve as archetypal images, similar to the sandplay images constructed by the clients. As the language of the unconscious, the SDTXH effectively bridge the conscious and unconscious, enabling the unconscious content, namely the archetype, to be symbolically expressed and bringing order to the creator through active imagination. The emergence of the SDTXH signifies the practitioner’s progress towards achieving psychic wholeness. Full article

In order to improve the anti-fouling of stainless steel surfaces in outdoor or humid environments, a superhydrophobic modification is often used to improve its self-cleaning performance. However, the mechanical stability of superhydrophobic surfaces remains a challenge. In this paper, a two-step preparation method was adopted to prepare the micro–nanocomposite coating, which innovatively combined “top-down” and “bottom-up” approaches, and also coupled together two key factors that affect superhydrophobicity: a rough microstructure, and low surface energy. The silver mirror, adhesion, and pollution-resistance results show that the composite coating samples, which were obtained by optimizing the preparation process, have excellent water repellency and self-cleaning properties. Meanwhile, the samples demonstrate outstanding mechanical stability, and can resist damage from sandpaper and tape. The two-step preparation method was simple, fast, and efficient. This method could be popularized and applied to the preparation of superhydrophobic surfaces on metal substrates. Full article

Uncertain provenance and tectonic setting of shale has constrained the exploration and exploitation of natural gas in the Wufeng–Longmaxi Formation in the southern Sichuan Basin, China. Therefore, this study analyzed the mineral petrology and geochemistry to assess the effects of sorting, recycling, weathering, and paleoclimate on the deeply buried shale. The findings revealed that the mineral composition is dominated by biogenic quartz, terrigenous clay minerals, and carbonate minerals. Combinations of clay lamina and silty lamina occur in black shale. The geochemical characteristics of these sedimentary rocks remain unaffected by sedimentary sorting and recycling processes. The clastic sediments primarily originate from the felsic igneous rock source that underwent moderate weathering during its initial deposition in the collision environment. Based on the comprehensive analysis of the paleoclimate and paleoprovenance characteristics, Wufeng–Longmaxi Formation characteristics are considered to have undergone six stages, among which the stage of relative enrichment of organic matter corresponds to LM1, LM2–3, and LM4. Following the Hirnantian glacial period, the era has witnessed global warming, marked by glacier melting, a rise in global sea level, and a decrease in terrestrial debris supply, collectively facilitating organic matter enrichment. During the LM5 and LM6–8 periods, the increase in source supply caused by the Leshan–Longnvsi and Qianzhong–Xuefeng uplift inhibited organic matter enrichment. Full article

Rapid eye movement (REM) sleep is the main sleep correlate of dreaming. Ponto-geniculo-occipital (PGO) waves are a signature of REM sleep. They represent the physiological mechanism of REM sleep that specifically limits the processing of external information. PGO waves look just like a message sent from the pons to the lateral geniculate nucleus of the visual thalamus, the occipital cortex, and other areas of the brain. The dedicated visual pathway of PGO waves can be interpreted by the brain as visual information, leading to the visual hallucinosis of dreams. PGO waves are considered to be both a reflection of REM sleep brain activity and causal to dreams due to their stimulation of the cortex. In this review, we summarize the role of PGO waves in potential neural circuits of two major theories, i.e., (1) dreams are generated by the activation of neural activity in the brainstem; (2) PGO waves signaling to the cortex. In addition, the potential physiological functions during REM sleep dreams, such as memory consolidation, unlearning, and brain development and plasticity and mood regulation, are discussed. It is hoped that our review will support and encourage research into the phenomenon of human PGO waves and their possible functions in dreaming. Full article

Single sensors often fail to meet the needs of practical applications due to their lack of robustness and poor detection accuracy in harsh weather and complex environments. A vehicle detection method based on the fusion of millimeter wave (mmWave) radar and monocular vision was proposed to solve this problem in this paper. The method successfully combines the benefits of mmWave radar for measuring distance and speed with the vision for classifying objects. Firstly, the raw point cloud data of mmWave radar can be processed by the proposed data pre-processing algorithm to obtain 3D detection points with higher confidence. Next, the density-based spatial clustering of applications with noise (DBSCAN) clustering fusion algorithm and the nearest neighbor algorithm were also used to correlate the same frame data and adjacent frame data, respectively. Then, the effective targets from mmWave radar and vision were matched under temporal-spatio alignment. In addition, the successfully matched targets were output by using the Kalman weighted fusion algorithm. Targets that were not successfully matched were marked as new targets for tracking and handled in a valid cycle. Finally, experiments demonstrated that the proposed method can improve target localization and detection accuracy, reduce missed detection occurrences, and efficiently fuse the data from the two sensors. Full article

After a vacuum failure in a tokamak, plasma runaway or plasma disruptions frequently occur during plasma recovery, causing difficulties in rebuilding a well-confined collisional plasma. In this work, the impurity behavior during plasma recovery after a vacuum failure in the 2019 spring campaign of the Experimental Advanced Superconducting Tokamak (EAST) was studied by analyzing the spectra recorded by fast-time-response extreme ultraviolet (EUV) spectrometers with 5 ms/frame. During the plasma current ramp-up in recovery discharges, a high content of the low-Z impurities of oxygen and carbon was found, i.e., dozens of times higher than that of normal discharges, which may have caused the subsequent runaway discharges. The electron temperature in the recovery discharge may have dropped to less than 75 eV when the collisional plasma quenched to the runaway status, based on the observable impurity ions in the two cases. Therefore, the lifetime of collisional plasma in the recovery discharge, τ_c, was deduced from the lifetime of H- and He-like oxygen and carbon ions identified from EUV spectra. It was found that, after several discharges with real-time lithium granule injection, the runaway electron flux and O⁺ influx reduced to 45% and 20%, respectively. Meanwhile, the lifetime of confined plasma was extended from 113 ms to 588 ms, indicating the effective suppression of impurities and runaway electrons and improvement in plasma performance by real-time lithium granule injection. The results in this work provide valuable references for the achievement of first plasma in future superconducting fusion devices such as ITER and CFETR. Full article

Inhibitors from lignocellulosic biomass have become the bottleneck of biorefinery development. Gluconobacter oxydans DSM2003 showed a high performance of inhibitors degradation, which had a short lag time in non-detoxified corn stover hydrolysate and could convert 90% of aldehyde inhibitors to weaker toxic acids. In this study, an aldehyde dehydrogenase gene W826-RS0111485, which plays an important function in the conversion of aldehyde inhibitors in Gluconobacter oxydans DSM2003, was identified. W826-RS0111485 was found by protein profiling, then a series of enzymatic properties were determined and were heterologously expressed in E. coli. The results indicated that NADP is the most suitable cofactor of the enzyme when aldehyde inhibitor is the substrate, and it had the highest oxidation activity to furfural among several aldehyde inhibitors. Under the optimal reaction conditions (50 °C, pH 7.5), the Km and Vmax of the enzyme under furfural stress were 2.45 and 80.97, respectively, and the Kcat was 232.22 min⁻¹. The biodetoxification performance experiments showed that the recombinant E. coli containing the target gene completely converted 1 g/L furfural to furoic acid within 8 h, while the control E. coli only converted 18% furfural within 8 h. It was further demonstrated that W826-RS0111485 played an important role in the detoxification of furfural. The mining of this inhibitor degradation gene could provide a theoretical basis for rational modification of industrial strains to enhance its capacity of inhibitor degradation in the future. Full article

Three-dimensional object detection is an essential and fundamental task in the field of computer vision which can be widely used in various scenarios such as autonomous driving and visual navigation. In view of the current insufficient utilization of image information in current monocular camera-based 3D object detection algorithms, we propose a monocular 3D object detection algorithm based on pseudo-multimodal information extraction and keypoint estimation. We utilize the original image to generate pseudo-lidar and a bird’s-eye view, and then feed the fused data of the original image and pseudo-lidar to the keypoint-based network for an initial 3D box estimation, finally using the bird’s-eye view to refine the initial 3D box. The experimental performance of our method exceeds state-of-the-art algorithms under the evaluation criteria of 3D object detection and localization on the KITTI dataset, achieving the best experimental performance so far. Full article