Explore the vast range of titles available.

Reinforced Concrete (RC) barriers are used for different purposes in the highway inventory. An important purpose is the use of concrete barriers to act as railing that protects bridge piers against vehicular collision force (VCF). Therefore, these barriers are designed to absorb the collision energy and/or redirect the vehicle away from the parts being protected. Accurate estimation of the capacity of RC barriers during crash events is an important consideration in their design and placement. The American Association of State Highway and Transportation Officials (AASHTO) considers yield line analysis (YLA) with the V-shape failure pattern to predict the barrier capacity. AASHTO’s analysis method involves some assumptions that are intended to simplify the analysis process. Some of these assumptions have been shown to underestimate the actual barrier capacity and might disqualify many existing RC barriers from acting as intervening structures due to structural inadequacy. Many researchers have proposed alternative failure patterns and methodologies in an attempt to better predict the capacity of RC barriers. This research shows that AASHTO’s YLA, with the current V-shape failure pattern, can be improved and still predict the barrier capacity when some of the simplifying assumptions are eliminated. Also, the research presents an alternative innovative truss analogy model to predict the capacity of RC barriers. The results of the improved YLA and the proposed truss model are validated by finite element analysis (FEA) using Abaqus. The results of this research will help structural engineers in the highway industry to initially design new barriers for the intended capacity as well as estimate the capacity of existing ones.

Objectives: Farnesoid X receptor (FXR) activation is involved in ameliorating inflammatory bowel disease (IBD), such as ulcerative colitis (UC), and inflammatory regulation may be involved in its mechanism. Ginsenoside Rc (Rc) is a major component of Panax ginseng , and it plays an excellent role in the anti-inflammatory processes. Our aim is to explore the alleviative effect of Rc on dextran sulfate sodium (DSS)-induced inflammation and deficiencies in barrier function based on FXR signaling. Materials and Methods: In vitro , we treated human intestinal epithelial cell lines (LS174T) with LPS to explore the anti-inflammatory effect of Rc supplementation. In vivo , a DSS-induced IBD mice model was established, and the changes in inflammatory and barrier function in colons after Rc treatment were measured using the disease activity index (DAI), hematoxylin and eosin (H&E) staining, immunofluorescence, ELISA, and qPCR. Molecular docking analysis, luciferase reporter gene assay, and qPCR were then used to analyze the binding targets of Rc. DSS-induced FXR-knockout (FXR −/- ) mice were used for further validation. Results: Rc significantly recovered the abnormal levels of inflammation indexes ( TNF-α , IL-6 , IL-1β , and NF-KB ) induced by LPS in LS174T. DSS-induced C57BL/6 mice exhibited a significantly decreased body weight and elevated DAI, as well as a decrease in colon weight and length. Increased inflammatory markers ( TNF-α , IL-6 , IL-1β , ICAM1 , NF-KB , F4/80, and CD11b displayed an increased expression) and damaged barrier function ( Claudin-1 , occludin, and ZO-1 displayed a decreased expression) were observed in DSS-induced C57BL/6 mice. Nevertheless, supplementation with Rc mitigated the increased inflammatory and damaged barrier function associated with DSS. Further evaluation revealed an activation of FXR signaling in Rc-treated LS174T, with FXR , BSEP, and SHP found to be upregulated. Furthermore, molecular docking indicated that there is a clear interaction between Rc and FXR, while Rc activated transcriptional expression of FXR in luciferase reporter gene assay. However, these reversal abilities of Rc were not observed in DSS-induced FXR −/- mice. Conclusion: Our findings suggest that Rc may ameliorate inflammation and barrier function in the intestine, which in turn leads to the attenuation of DSS-induced UC, in which Rc may potentially activate FXR signaling to protect the intestines from DSS-induced injury.

Atomically thin molybdenum disulfide (MoS2), a member of the transition metal dichalcogenide (TMDC) family, has emerged as the prototypical two-dimensional (2D) semiconductor with a multitude of interesting properties and promising device applications spanning all realms of electronics and optoelectronics. While possessing inherent advantages over conventional bulk semiconducting materials (such as Si, Ge and III-Vs) in terms of enabling ultra-short channel and, thus, energy efficient field-effect transistors (FETs), the mechanically flexible and transparent nature of MoS2 makes it even more attractive for use in ubiquitous flexible and transparent electronic systems. However, before the fascinating properties of MoS2 can be effectively harnessed and put to good use in practical and commercial applications, several important technological roadblocks pertaining to its contact, doping and mobility (µ) engineering must be overcome. This paper reviews the important technologically relevant properties of semiconducting 2D TMDCs followed by a discussion of the performance projections of, and the major engineering challenges that confront, 2D MoS2-based devices. Finally, this review provides a comprehensive overview of the various engineering solutions employed, thus far, to address the all-important issues of contact resistance (RC), controllable and area-selective doping, and charge carrier mobility enhancement in these devices. Several key experimental and theoretical results are cited to supplement the discussions and provide further insight.

We report on the electron analog of the single-photon gun. On-demand single-electron injection in a quantum conductor was obtained using a quantum dot connected to the conductor via a tunnel barrier. Electron emission was triggered by the application of a potential step that compensated for the dot-charging energy. Depending on the barrier transparency, the quantum emission time ranged from 0.1 to 10 nanoseconds. The single-electron source should prove useful for the use of quantum bits in ballistic conductors. Additionally, periodic sequences of single-electron emission and absorption generate a quantized alternating current.

A novel approach to achieving the free-wheeling function in a lateral insulated-gate bipolar transistor (LIGBT) with an embedded anti-parallel floating Schottky barrier diode (FOB) is proposed and investigated using numerical TCAD simulations. The novel snapback-free reverse-conducting LIGBT integrates a FOB, consisting of a floating ohmic contact and a Schottky barrier diode shorted by the floating metal, enabling a reverse conduction path to be obtained by the FOB. Moreover, an oxide layer is embedded between the LIGBT and the Schottky barrier diode (SBD) to completely eliminate snapback and effectively improve the breakdown characteristics, turn-off time, and the trade-off relationship between the on-state voltage drop (Von) and the turn-off energy loss (Eoff). The simulation results show that the proposed FOB-LIGBT reduces the Eoff by 41.1%, 44.3%, and 60.4% at Von of 1.52 V compared with the self-biased n-MOS (SBM), single-trench barrier (STB), and separated shorted anode (SSA) LIGBT designs, respectively. Moreover, the breakdown voltage (BV) of the proposed FOB-LIGBT is 408 V, while the values for the previous SBM-, STB-, and SSA-LIGBT devices are 362 V, 367 V, and 359 V, respectively.

This paper investigates an adaptive neural networks (NNs) event-triggered optimal control method for the second-order resistance capacitance (RC) equivalent circuit system with state constraints. The NNs are used to estimate the unknown nonlinear functions. In order to constrain the states within the designed boundary in optimal control strategy, the barrier Lyapunov function (BLF) method is taken into account. Furthermore, to economic the transmission resources, the adaptive NNs event-triggered optimizing control strategy is developed by employing the relative threshold strategy. The proposed optimal control strategy is not only able to satisfy the stability of closed-loop system, but also can guarantee the performance index functions minimized when all states remain within the given boundaries. Finally, the effectiveness of the suggested control method is demonstrated by simulation.

This paper investigates a dynamic event-triggered robust safety control method for multiplayer fully cooperative games with mismatched uncertainties and asymmetric input constraints under continuous-time nonlinear systems. Firstly, to address the safety constraints on the system states, a suitable barrier function is proposed to transform the original constrained system into an unconstrained system. Subsequently, through the construction of an auxiliary system, the robust control (RC) problem is transformed into optimal control problem with auxiliary control laws. Secondly, the control laws are subjected to asymmetric constraints by designing a non-quadratic function. Unlike traditional static event-triggered control, a new dynamic event-triggered mechanism is introduced for updating the control laws. In addition, a new critic neural network (NN) weight update method is constructed to approximate the solution of the event-triggered Hamiltonian Jacobi Bellman (HJB) equation by using the concurrent learning technique. Furthermore, Lyapunov’s theorem proves that the closed-loop system is uniformly ultimately bounded (UUB). Finally, a simulation example of a single-linked robotic arm is provided to verify the validity of the proposed method in this paper.

This work proposes an electrical model that combines homogeneous and filamentary modes of an atmospheric pressure dielectric barrier discharge cell. A voltage controlled electric current source has been utilized to implement the power law equation that represents the homogeneous discharge mode, which starts when the gas breakdown voltage is reached. The filamentary mode implies the emergence of electric current conducting channels (microdischarges), to add this phenomenon an RC circuit commutated by an ideal switch has been proposed. The switch activation occurs at a higher voltage level than the gas breakdown voltage because it is necessary to impose a huge electric field that contributes to the appearance of streamers. The model allows the estimation of several electric parameters inside the reactor that cannot be measured. Also, it is possible to appreciate the modes of the DBD depending on the applied voltage magnitude. Finally, it has been recognized a good agreement between simulation outcomes and experimental results.

Ginsenoside Rc (Rc) is a major ginsenoside isolated from Panax ginseng, and has exhibited pharmacological effects on skin cells. The present study aimed to investigate the putative skin-protective properties of Rc, including its anti-photoaging and barrier function-protective effects, in human HaCaT keratinocytes exposed to UVB radiation. The protective properties of Rc were evaluated through the assessment of keratinocyte viability, reactive oxygen species (ROS) production, total glutathione (GSH) and superoxide dismutase (SOD) activity, caspase-14, matrix metalloproteinase (MMP)-2 and −9 activity, and MMP-2, MMP-9 and filament aggregating protein (filaggrin) expression following UVB irradiation. Treatment with Rc was revealed to prevent the UVB-induced increase in ROS production and pro-MMP-2 and −9 levels in HaCaT keratinocytes. In addition, treatment with Rc resulted in enriched GSH contents and enhanced SOD activity following exposure to UVB radiation. Furthermore, Rc treatment enhanced caspase-14 activity and counteracted the UVB-induced downregulation in filaggrin expression. However, no significant difference was identified between Rc-treated and normal groups in terms of keratinocyte viability, regardless of exposure to radiation. The present findings suggested that Rc may exert anti-photoaging and barrier function-protective effects in keratinocytes, and thus protect the skin against photooxidative stress induced by exposure to UV radiation.

This paper investigates the self-pulsing of Dielectric Barrier Discharges (DBDs) at low driving frequencies. In particular, (a) the dependence of current on the product pd of gas pressure p and the gas gap length d, (b) the effects of lossy dielectrics (in resistive discharges) and large dielectric permittivity (in ferroelectrics) on current dynamics, (c) the transition from Townsend to a dynamic Capacitively Coupled Plasma (CCP) discharge with changing pd values, and (d) the transition from Townsend to a high-frequency CCP regime with increasing the driving frequency. A one-dimensional fluid model of Argon plasma is coupled to an equivalent RC circuit for lossy dielectrics. Our results show multiple current pulses per AC period in Townsend and CCP discharge modes which are explained by uncoupled electron-ion transport in the absence of quasineutrality and surface charge deposition at dielectric interfaces. The number of current pulses decreases with an increasing applied frequency when the Townsend discharge transforms into the CCP discharge. The resistive barrier discharge with lossy dielectrics exhibits Townsend and glow modes for the same pd value (7.6 Torr cm) for higher and lower resistances, respectively. Finally,we show that ferroelectric materials can amplify discharge current in DBDs. Similarities between current pulsing in DBD, Trichel pulses in corona discharges, and subnormal oscillations in DC discharges are discussed. 1