Application and Exploration of FLUENT Software in the Teaching of Engineering Thermophysics

Engineering thermophysics is a basic discipline for energy majors, but this course emphasizes the theoretical level and is difficult to understand. Students\u27 enthusiasm and participation in the learning process are low, and it is difficult to understand the course. Accordingly, the research team attempts to introduce Fluent software into the course teaching exploration. Specifically, Fluent software is adopted to provide a reliable physics teaching model, and to change the traditional teaching mode, so as to improve students\u27 daily learning ability and practical ability, and ultimately enable students to learn and practice

Data Associated with "Logjam Characteristics as Drivers of Transient Storage in Headwater Streams"

This repository contains data for the experimental flume and numerical model runs referenced in Marshall et al., 2022. Source code, data csv files for statistical analysis, and calculated temporal moments are included.Logjams in a stream create backwater conditions and locally force water to flow through the streambed, creating zones of transient storage within the surface and subsurface of a stream. We investigate the relative importance of logjam distribution density, logjam permeability, and discharge on transient storage in a simplified experimental channel. We use physical flume experiments in which we inject a salt tracer, monitor fluid conductivity breakthrough curves in surface water, and use breakthrough-curve skew to characterize transient storage. We then develop numerical models in HydroGeoSphere to reveal flow paths through the subsurface (or hyporheic zone) that contribute to some of the longest transient-storage timescales. In both the flume and numerical model, we observe an increase in backwater and hyporheic exchange at logjams. Observed complexities in transient storage behavior may depend largely on surface water flow in the backwater zone. As expected, multiple successive logjams provide more pervasive hyporheic exchange by distributing the head drop at each jam, leading to distributed but shallow flow paths. Decreasing the permeability of a logjam or increasing the discharge both facilitate more surface water storage and elevate the surface water level upstream of a logjam, thus increasing hyporheic exchange. Multiple logjams with low permeability result in the greatest magnitude of transient storage, suggesting that this configuration maximizes solute retention in backwater zones, while hyporheic exchange rates also increase. Understanding how logjam characteristics affect solute transport through both the channel and hyporheic zone has important management implications for rivers in forested, or historically forested, environments.This research was supported by National Science Foundation Hydrologic Sciences (award 1819068)

A Student\u27s Guide to giant Viruses Infecting Small Eukaryotes: From Acanthamoeba to Zooxanthellae

The discovery of infectious particles that challenge conventional thoughts concerning “what is a virus” has led to the evolution a new field of study in the past decade. Here, we review knowledge and information concerning “giant viruses”, with a focus not only on some of the best studied systems, but also provide an effort to illuminate systems yet to be better resolved. We conclude by demonstrating that there is an abundance of new host–virus systems that fall into this “giant” category, demonstrating that this field of inquiry presents great opportunities for future research

Holstein Cattle Face Re-Identification Unifying Global and Part Feature Deep Network with Attention Mechanism

In precision dairy farming, computer vision-based approaches have been widely employed to monitor the cattle conditions (e.g., the physical, physiology, health and welfare). To this end, the accurate and effective identification of individual cow is a prerequisite. In this paper, a deep learning re-identification network model, Global and Part Network (GPN), is proposed to identify individual cow face. The GPN model, with ResNet50 as backbone network to generate a pooling of feature maps, builds three branch modules (Middle branch, Global branch and Part branch) to learn more discriminative and robust feature representation from the maps. Specifically, the Middle branch and the Global branch separately extract the global features of middle dimension and high dimension from the maps, and the Part branch extracts the local features in the unified block, all of which are integrated to act as the feature representation for cow face re-identification. By performing such strategies, the GPN model not only extracts the discriminative global and local features, but also learns the subtle differences among different cow faces. To further improve the performance of the proposed framework, a Global and Part Network with Spatial Transform (GPN-ST) model is also developed to incorporate an attention mechanism module in the Part branch. Additionally, to test the efficiency of the proposed approach, a large-scale cow face dataset is constructed, which contains 130,000 images with 3000 cows under different conditions (e.g., occlusion, change of viewpoints and illumination, blur, and background clutters). The results of various contrast experiments show that the GPN outperforms the representative re-identification methods, and the improved GPN-ST model has a higher accuracy rate (up by 2.8% and 2.2% respectively) in Rank-1 and mAP, compared with the GPN model. In conclusion, using the Global and Part feature deep network with attention mechanism can effectively ameliorate the efficiency of cow face re-identification

Why and When Temporary Workers Engage in More Counterproductive Work Behaviors with Permanent Employees in Chinese State-Own Enterprise: A Social Identity Perspective

Why do temporary workers sharing the same working conditions as permanent employees still frequently engage in deviant behaviors that negatively affect the organization’s interests? Drawing on the theory of social identity, this articlr discusses the relationships among employment status, organizational identification, and counterproductive work behavior. Time-lagged data were collected from sample of 210 dyads of employees and corresponding supervisors from a large Chinese state-owned service company, to test hypothesis. Results showed that temporary workers engage in counterproductive work behaviors more frequently than permanent employees, and organizational identification plays a mediating role in this process. Turnover intention moderated the relationship between employment status and counterproductive work behavior (organizational identification). In terms of turnover intention, organizational identification and counterproductive work behavior, two types of employees did not exhibit a significant difference. However, when turnover intention increase, there was a sharper decline in organizational identification and a greater increase in counterproductive work behaviors among temporary employees than among permanent employees. Finally, the theoretical and practical implications of these findings and future research directions are discussed

A programmable-gain amplifier and an active inductor for in-vehicle power line communications

In-vehicle power-line communication (VPLC) is a communication technique that uses the power lines of the vehicle for data transmission. Based on the measurements of the power line communication channel, the channel response is characterized as frequency selective, time and location dependent with high signal attenuation. Also, the access impedance changes a lot in different frequency ranges. These properties impose design challenges at both system level and circuit levels of a VPLC system. This thesis presents the design of two critical building blocks of a VPLC system, namely, a variable gain amplifier (VGA) and an active inductor. VGAs are used to amplify the signal to a predefined level without introducing too much distortion. The presented VGA design targets a 0.13μm CMOS technology. The VGA design is discussed in detail. Gm-boosting technique is used to both increases the linearity and provide a programmable 0 dB to 60 dB gain over a broadband. Furthermore, the gain is stable over a wide range of temperatures. The circuit is fabricated and tested, and the measured results are in good agreement with the simulation results. Inductors are commonly used in impedance matching networks. In this work, an active inductor circuit is designed which provides a wide tuning range for VPLC LC matching networks. Active inductor is a good candidate to replace the passive inductor in the LC matching network since it has a smaller area, wider tuning range, and a higher quality-factor. The designed active inductor is a fully differential grounded Gyrator-C active inductor. Simulation results confirm that the inductor has wide tuning range with linear tuning ability; however, its bandwidth is limited. The circuit design for this VPLC system is challenging, the preliminary results of the proposed circuits show some promise; however, further work is still needed to improve the performance.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat

The role of IGFBP-5 proteolysis in regulating IGF bioavailablity in pregnancy

The insulin-like growth factor binding proteins (IGFBPs) are a group of six structurally related proteins that modulate the activity of insulin-like growth factors (IGF—I and IGF—II) through high—affinity interaction. IGFs circulate in binary complexes with individual IGFBPs, and in high molecular mass ternary complexes with either IGFBP-3 or IGFBP-5, and the acid-labile subunit (ALS). Formation of IGF complexes prolongs the half-lives of IGFs in the circulation and limits their access to target tissues. Proteolysis of IGFBPs, on the other hand, generates IGFBP fragments that have greatly reduced IGF affinity and it is thought to be the key mechanism invoked to increase IGF bioavailability in response to the body’s metabolic demand in certain conditions such as pregnancy. It has long been known that serum IGFBP-3 undergoes proteolysis in pregnancy and other catabolic states. Circulating IGFBP-5 proteases capable of proteolysing IGFBP-5 in vitro have also been described. The current study aimed to characterise IGFBP-5 proteolytic activity in pregnancy plasma and to determine whether the proteolysis of the binding protein contributes to the regulation of IGF tissue bioavailability. With the use of affinity-purified IGFBP-5 antibody in Western immunoblotting, it was demonstrated that plasma IGFBP-5 was fully proteolysed into stable fragments at all stages of pregnancy. A pregnancy-specific IGFBP-5 proteolytic activity was identified in the >150 kDa gel-filtration fraction from pregnancy plasma. The proteolytic activity was identical, in the cleavage of IGFBP-5, to that of PAPP-A or PAPP-A2 which cleaved recombinant IGFBP-5 at one site between Serl43 and Lysl44. Proteolysis of IGFBP-5 by the activity was fully inhibited by a PAPP-AZ antibody but not by a PAPP—A antibody, suggesting that PAPP—A2 was the protease involved in the proteolysis of IGFBP-5 in pregnancy plasma. The proteolytic fragments of IGFBP-5, representing the cleavage products by the PAPP-A2 activity, were also identified in pregnancy plasma. The recombinant pregnancy IGFBP-S fragments, IGFBP—Sl'143 and IGFBP-SI‘M‘ZSZ, showed markedly reduced affinities for IGFS compared to the intact protein. Despite exhibiting cooperativity in IGF binding, the two fragments were unable to form IGF complexes efficiently. Functional assays using IGF-I sensitive cells showed that the fragments, either individually or in combination, were less potent than the intact protein in inhibiting IGF-Iinduced type 1 IGF receptor phosphorylation. Conversely, proteolysis of IGFBP-5 by pregnancy plasma released free bioactive IGF-I from IGF-I-IGFBP-S complexes, and the released IGF-I appeared to remain biologically active after being transported across the vascular endothelial cell barrier. In summary, this study has characterised IGFBP-S fragments from pregnancy plasma and provided evidence that PAPP—AZ is the protease responsible for the proteolysis of IGFBP—5. Proteolysis of IGFBP-5 can markedly affect the stability of IGFBP-5 complexes and contribute to increased IGF bioavailability during pregnancy