Search

Bridge abutment scour is a complex phenomenon, which significantly affects bridge stability and is responsible for the damage and failures of many bridges over waterways across the world. Given the widespread and devastating human and societal costs, numerous experimental studies have been conducted to find the mechanisms of bridge abutment scour, and several empirical and mathematical prediction models are available. However, the location of the scour hole and its extents have not been investigated in detail, which is one of the important parameters, not only for the bridge stability itself, but also for the safety of structures around the bridge and their design. Thus, in this study, laboratory experiments were carried out using several different lengths of erodible abutment under different flow conditions to suggest a new mathematical criterion for abutment classification with respect to the location of scour holes. Furthermore, additional analysis was conducted to locate the point of the deepest scour depth and extent of the scour hole around the abutment. Both in transverse and flow direction, the location of the scour hole and the point of the deepest scour are governed by the geometric contraction ratio. This research will be useful in analyzing the bridge safety itself as well as safety of the river training works close to the bridge with respect to the location and extents of the scour hole.

In a cyber-physical system, enterprise applications, control functions, and physical manufacturing assets are interconnected to seamlessly exchange information. However, the software and hardware often differ in terms of their data interfaces, data formats and semantics. Conventional enterprise applications usually employ file-based interfaces (e.g., Excel); control applications always support Ethernet-based protocols (e.g., OPC UA). Thus, data interoperability is currently lacking. The asset administration shell (AAS) is a new approach for achieving data interoperability across the automation pyramid as the AASX data format represents AAS information and supports data communication via OPC UA. In this study, we first provide insights into the AASX format and give exemplary applications on AASX; we then present an AASX-based solution for bidirectional data exchange between enterprise and control applications. In this solution, the conversion between AASX and Excel spreadsheets is completed to enable interoperable data exchange. Finally, a data exchange scenario for motor control is constructed to validate the effectiveness of the solution. The result shows no data were lost during the two-way conversions.

In the present study, biosynthesized silica-based zinc oxide nanocomposites (nano-SZO) have been explored as nanoadsorbent for sequestrating heavy metal ions viz. Ni2+, Cd2+and Cu2+ from synthetic medium. The nanocomposites have been obtained by utilization of agricultural waste by means of green synthetic approach with an average particle size of 30.52 nm and a pH at zero-point charge as 4.8. The process has been optimized at a pH equal to 5.0 for Ni2+ and 6.0 for Cu2+ and Cd2+. Adsorption was best described by Langmuir isotherm and the highest value of maximum adsorption capacity, qm of nano-SZO was obtained for Cu2+ (32.53 mg/g), Ni2+ (32.10 mg/g), and Cd2+ (30.98 mg/g). The studied heavy metal ions are considerably adsorbed by the nano-SZO through chemisorption by active binding with polyhydroxy functionalities attached at the surface of the nanoadsorbent confirming the utilization of biosynthesized nano-SZO as eco-friendly and efficient nano adsorbents for the sequestration of heavy metal ions.

Demand response (DR) has been widely recognized as an effective solution to help mitigate the stresses imposed on power grids. As new concepts evolve, DR induces various interactions among multiple emerging entities, which further complicates the decision-making processes in grid operations. Recently, game theory (GT) has received great attention in DR management, due to its ability to handle complex decision-making problems. Numerous theoretical GT-based approaches have been proposed for addressing various DR issues, but the feasibility of these theoretical approaches in practical implementation remains in doubt. To bridge the gap between theoretical studies and practical implementations, we first provide specific guidelines regarding how to construct a DR-oriented facility, and then investigate the effectiveness of deploying a Stackelberg game theory-based DR algorithm to manage the energy consumption of the facility, wherein the energy management center (EMC) serves as the leader and multiple devices act as the followers. The experimental evaluation results show that the GT-based DR algorithm achieved great performance in practical DR management, including optimal load control in responding to real-time price (RTP), and peak load reduction with a peak-to-average ratio (PAR) of 1.59.

The multifaceted industrial application of cyber-physical systems (CPSs) has increased, enabling tight interactions between physical and computational elements. Industry 4.0 aims to promote industrial application of CPSs. The asset administration shell (AAS) represents the practical embodiment of the CPS, and can be obtained by integrating information and communication technologies. Most prior studies concentrated on AASs for hardware assets in the manufacturing domain; they seldom considered AASs for software applications. To fill this gap, we present a method for implementing AASs for software, i.e., a manufacturing execution system (MES) combined with an enterprise resource planning (ERP) system. This method allows runtime data exchange between an MES and ERP; this is better than the conventional file-based method. Finally, a data exchange case (a manufacturing order) is presented to validate our AAS method.

The increasing penetration of cyber-physical system (CPS) technologies in industry is transforming this environment into a multifaceted system featuring a tight combination of its physical and computational elements, including their digital (virtual) representations, contributing to the concept of an industrial CPS. The German “Industry 4.0” is a key innovation program aimed at realizing industrial CPS. Industry 4.0 is characterized by digital industrial components interacting with each other to become systems meeting flexible industrial demands, e.g., order-controlled production. An asset administration shell (AAS), as defined in the context of the Reference Architectural Model for Industry 4.0 (RAMI 4.0), is a practical embodiment of the latest buzzword, digital twin, and can be realized with the integration of operation technologies and information and communication technologies. AASs offer an interoperable way to capture key information pertaining to assets, such as intrinsic properties, operational parameters, and technical functionalities, and to enable straightforward interaction over standardized, secure communication with other Industry 4.0 components. The goal of this article is to present the status quo of AAS development, to design an intuitive method for implementing AASs, and to develop an AAS-enabled digital solution for cyber-physical applications in the manufacturing sector. Last but not least, we demonstrate a case study featuring an Industry 4.0 application scenario, i.e., plug-and-produce.

In modern manufacturing systems, various industrial communication systems (e.g., fieldbus systems and industrial Ethernet networks) have been used to realize reliable information exchange. However, these industrial communication solutions are largely incompatible with each other, which do not satisfy the new requirements of Industry 4.0. Recently Time-Sensitive Networking (TSN) has been developed to improve the real-time capabilities to the standard Ethernet, and is considered to be a promising real-time communication solution for Industry 4.0. In this work, we propose a communication architecture for a manufacturing system using the Open Platform Communications Unified Architecture (OPC UA) and TSN technologies. TSN is adopted as the communication backbone to connect heterogeneous industrial automation subsystems. The OPC UA is adopted to realize horizontal and vertical communication between subsystems in the field layer and the entities of the upper layers. We implement a laboratory-level manufacturing system to validate the proposed architecture. The experimental results demonstrate the feasibility and capability of the proposed architecture. Moreover, we evaluate the performance of a key TSN substandard, i.e., IEEE 802.1Qbv, in the laboratory-level manufacturing system. The evaluation results demonstrate that IEEE 802.1Qbv can indeed provide excellent real-time capabilities for industrial applications.

The future manufacturing environment is foreseen to be increasingly diverse with multi-vendor industrial wireless devices deployed in the same geographical area. Thus, effective medium resource sharing mechanisms are urgently needed to enable the coexistence of those heterogeneous industrial wireless sensor networks (IWSNs). To accommodate such heterogeneity, this paper proposes a collaborative scheduling algorithm (CSA) for coordinating the activation of each coexisting IWSN while guaranteeing their respective real-time communication requirements. Specifically, the proposed CSA is able to help determine a unique data transmission instantance for each network node that periodically generates time-sensitive data, through which timely data delivery is guaranteed without the interference of each other.

As a major consumer of energy, the industrial sector must assume the responsibility for improving energy efficiency and reducing carbon emissions. However, most existing studies on industrial energy management are suffering from modeling complex industrial processes. To address this issue, a model-free demand response (DR) scheme for industrial facilities was developed. In practical terms, we first formulated the Markov decision process (MDP) for industrial DR, which presents the composition of the state, action, and reward function in detail. Then, we designed an actor-critic-based deep reinforcement learning algorithm to determine the optimal energy management policy, where both the actor (Policy) and the critic (Value function) are implemented by the deep neural network. We then confirmed the validity of our scheme by applying it to a real-world industry. Our algorithm identified an optimal energy consumption schedule, reducing energy costs without compromising production.

As a levee failure and the consequent flooding cause significant financial losses and sometimes human casualties, they have led to considerable concern among city officials. Therefore, researchers have devoted considerable effort to investigating the hydraulic characteristics of sudden transient flow in the form of propagated waves to inundation areas during a levee and/or dam failure. A large number of studies, however, have mostly focused on simple one-dimensional cases investigated numerically and/or experimentally, and thus, important hydraulic characteristics, particularly near the failure zone, have not been adequately captured because of three-dimensional complexities. Taking these complexities into consideration, this study conducts a large-scale experiment to examine the characteristics of wave propagation in an open area caused by a gradual levee failure. From the experimental observations, this study provides the propagation speed of a wave front and suggests a formula for the maximum flood depth corresponding to the peak flood wave in the inundation area. We expect the findings to provide hydraulic engineers and scientists with fundamental insights into transient flow during a gradual levee failure. By contributing to our theoretical understanding, the measurements can also be used as validation tools for future numerical simulation and are likely to contribute to the establishment of emergency action plans that can help city officials cope with flood inundation.

Electromagnetic coils are one of the key components of many systems. Their insulation failure can have severe effects on the systems in which coils are used. This paper focuses on insulation degradation monitoring and remaining useful life (RUL) prediction of electromagnetic coils. First, insulation degradation characteristics are extracted from coil high-frequency electrical parameters. Second, health indicator is defined based on insulation degradation characteristics to indicate the health degree of coil insulation. Finally, an insulation degradation model is constructed, and coil insulation RUL prediction is performed by particle filtering. Thermal accelerated degradation experiments are performed to validate the RUL prediction performance. The proposed method presents opportunities for predictive maintenance of systems that incorporate coils.

Little efforts have been made to the value of laboratory model study in closing the gap between results from idealized laboratory experiments and those from field data. Thus, at first, three bridge sites were selected and equipped with fathometers to find the bed elevation change in the vicinity of bridge pier over time. After and during the flooding, the stream flow variables and their bathymetry were measured using current viable technologies at the field. Then, to develop and suggest a laboratory modeling techniques, full three-dimensional physical models including measured river bathymetry and bridge geometry were designed and fabricated in a laboratory based on the scale ratio except for the sediment size, and the laboratory results were compared with the field measurements. Size of uniform sediment was carefully selected and used in the laboratory to explore the scale effect caused by sediment size scaling. The comparisons between laboratory results and field measurements show that the physical models successfully reproduced the flow characteristics and the scour depth around bridge foundations. With respect to the location of the maximum scour depth, they are not consistent with the results as in the previous research. Instead of occurring at the nose of each pier, the maximum scour depths are located further downstream of each pier column in several experimental runs because of the combination of complex pier bent geometry and river bathymetry, and the resulting unique flow motions around the pier bent.

Bridge pier scour is one of the main causes of bridge failure and a major factor that contributes to the total construction and maintenance costs of bridge. Recently, because of unexpected high water during extreme hydrologic events, the resilience and security of hydraulic infrastructure with respect to the scour protection measure along a river reach has become a more immediate topic for river engineering society. Although numerous studies have been conducted to suggest pier scour estimation formulas, understanding of turbulence characteristics which is dominant driver of sediment transport around a pier foundation is still questionable. Thus, to understand near bed turbulence characteristics and resulting sediment transport around a pier, hydraulic laboratory experiments were conducted in a prismatic rectangular flume using scale-down bridge pier models. Three-dimensional velocities and turbulent intensities before and after scour were measured with Acoustic Doppler Velocimeter (ADV), and the results were compared/analyzed using the best available tools and current knowledge gained from recent studies. The results show that the mean flow variable is not enough to explain complex turbulent flow field around the pier leading to the maximum scour because of unsteady flows. Furthermore, results of quadrant analysis of velocity measurements just upstream of the pier in the horseshoe vortex region show significant differences before and after scour.

Extreme rainfall events, larger than 500-year floods, have produced a large number of flooding events in the land and also close to the shore, and have resulted in massive destruction of hydraulic infrastructures because of scour. In light of climate change, this trend is likely to continue in the future and thus, resilience, security and sustainability of hydraulic infrastructures has become an interesting topic for hydraulic engineering stakeholders. In this study, a physical model experiment with a geometric similarity of the bridge embankments, abutments, and bridge deck as well as river bathymetry was conducted in a laboratory flume. Flow conditions were utilized to get submerged orifice flow and overtopping flow in the bridge section in order to simulate extreme hydrologic flow conditions. Point velocities of the bridge section were measured in sufficient details and the time-averaged velocity flow field were plotted to obtain better understandings of scour and sediment transport under high flow conditions. The laboratory study concluded that existing lateral flow contraction as well as vertical flow contraction resulted in a unique flow field through the bridge and the shape of velocity profile being “fuller”, thereby increasing the velocity gradients close to the bed and subsequently resulting in a higher rate of bed sediment transport. The relationships between the velocity gradients measured close to the bed and the degree of flow contraction through the bridge are suggested. Furthermore, based on the location of maximum scour corresponding to the measured velocity flow field, the classification of scour conditions, long setback abutment scour and short setback abutment scour, are also suggested.

Recently, the issues of scour around a bridge have become prominent because of the recurrent occurrence of extreme weather events. Thus, a bridge must be designed with the appropriate protection measures to prevent failure due to scour for the high flows to which it may be subjected during such extreme weather events. However, the current scour depth estimation by several recommended equations shows inaccurate results in high flow. One possible reason is that the current scour equations are based on experiments using free-surface flow even though extreme flood events can cause bridge overtopping flow in combination with submerged orifice flow. Another possible reason is that the current practice for the maximum scour depth ignores the interaction between different types of scour, local and contraction scour, when in fact these processes occur simultaneously. In this paper, laboratory experiments were carried out in a compound shape channel using a scaled down bridge model under different flow conditions (free, submerged orifice, and overtopping flow). Based on the findings from laboratory experiments coupled with widely used empirical scour estimation methods, a comprehensive way of predicting maximum scour depth is suggested which overcomes the problem regarding separate estimation of different scour depths and the interaction of different scour components. Furthermore, the effect of the existence of a pier bent (located close to the abutment) on the maximum scour depth was also investigated during the analysis. The results show that the location of maximum scour depth is independent of the presence of the pier bent but the amount of the maximum scour depth is relatively higher due to the discharge redistribution when the pier bent is absent rather than present.

Background: Erectile dysfunction (ED) is a common diabetes-related complication. Materials and methods: This study examined the effect of daily low-dose tadalafil (5mg) on patients' quality of life (including that of sex life) and blood circulation. Erectile dysfunction questionnaires were administered to 20 patients with type 2 diabetes (T2DM) and ED. The safety and efficacy of tadalafil were evaluated using laboratory tests, and the effect on blood circulation was measured through nail fold capillaroscopy. Results: Daily tadalafil use by patients with T2DM and ED showed a statistically significant increase in the erectile reliability score from of 1.15 to 3.20 (p < .00012). Capillary blood circulation improvement tests showed a statistically significant increase in apical limb width from 13.1 to 14.64 mm (p = .04829) and flow from 9035 to 11946 µm³/s (p = .04405). Although not significant, increased capillary width and speed (rate of blood flow) confirmed improved blood circulation. There were no significant changes in the cardiac indicators (troponin, prostate-specific antigen, or electrocardiogram tests) before and after tadalafil administration, supporting the safety of its low-dose daily administration. Conclusions: A small dose of daily tadalafil was shown to safely improve erectile dysfunction and peripheral blood flow in patients with T2DM, in which peripheral arterial diseases should not be considered separately but rather as complex entities. [ABSTRACT FROM AUTHOR]

Leptin receptors (LEPR) are located in the central nervous system and other tissues including adipocytes and endothelial cells, where they play a key role in mediating the effects of leptin. MicroRNA (miR/miRNA)-27a and miR-155 have been shown to play an important role in the regulation of LEPR expression and are differentially expressed in various diseases. Therefore, the present study analyzed potential associations of LEPR deletion/insertion (Del/Ins), miR-27aA>G (rs895819) and miR-155T>A (rs767649) polymorphisms with a predisposition to hypertension (HTN). Genotyping was performed by a PCR-restriction fragment length polymorphism assay. Frequencies of LEPR Del/Ins and miRNA gene polymorphisms in patients diagnosed with HTN (n=232) and randomly selected healthy controls (n=247) were assessed. The present study found that Del/Ins and Ins/Ins genotypes and the Ins allele of the LEPR Del/Ins polymorphism were associated with a decreased risk of HTN compared with controls, whereas the miR-27aA>G rs895819 polymorphism was associated with an increased risk of HTN. Combined genotype and allele analyses for LEPR Del/Ins and two miRNA polymorphisms revealed an association with an increased risk or a decreased risk of HTN. Furthermore, stratification analysis revealed that HTN risk factors were associated with waist circumference (WC) and high-density lipoprotein cholesterol (HDL-C) values in LEPR Del/Ins polymorphism. They were also associated with body mass index, WC, triglyceride and HDL-C values in miR-27aA>G polymorphism. The present study revealed a combined effect of LEPR Del/Ins and miR-27aA>G polymorphisms on the risk of HTN in Koreans, suggesting that these gene polymorphisms could be potential markers for predicting HTN risk. [ABSTRACT FROM AUTHOR]