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The correct identification of partial discharges (PDs) is instrumental for the maintenance plan in gas-insulated systems (GIS). However, onsite PD measurements are difficult, especially in HVDC systems, where partial discharges can be confused with interference. This paper proposes a method to discern PDs from interferences based on the GIS characteristic impedance. The characteristic impedance is measured using very-high frequency electric and magnetic sensors, and it is calculated using four approaches based on the PD charge magnitude, peak value, peak-to-peak value, and frequency spectrum. The method is first tested with a PD calibrator in a matched and open-circuited GIS testbench. Then, the identification of PDs and interference is tested in a full-scale GIS, where the measurements are subjected to pulse overlapping and noise. Five types of interferences and PDs are injected into the GIS in two positions and measured in multiple mounting holes. The results show that all four approaches can precisely calculate the characteristic impedance in a matched testbench. In the full-scale GIS, these approaches show more deviation, with the peak approach being the most accurate. A practical application of the method is demonstrated using a calibrator in the full-scale GIS. The proposed method contributes to a more reliable PD monitoring system for HVDC/AC GIS and allows better maintenance planning, reducing unnecessary costs, notably for offshore substations.

Abstract A compact fiber-optic magnetic field sensor is proposed by packaging an orthogonal dual-frequency fiber grating laser and a copper wire with alternating electrical current together inside epoxy resin. The alternating current generates Ampere force in a magnetic field, which changes the birefringence of the fiber laser and hence tunes the frequency of the beat signal after photodetection. The magnetic field magnitude can then be detected by measuring the frequency change of the beat signal. The sensitivity of the sensor can be tuned with a maximum response of 35.21 kHz/kGs demonstrated. Moreover, the sensor shows good immunity to environment interference.

The fractal characteristics of urban forms and road networks can provide extremely useful information for urban planning. Previous research, however, has hardly acknowledged the fractal nature of transit networks, although this topic is of vital importance given the significance of public transit to city operations. In this study, the fractal characteristics of urban surface transit and road networks were analyzed based on the case study of Strasbourg, France. Two fractal dimensions that are most widely used, the length dimension and branch dimension, were calculated and analyzed using regression and correlation analysis. The results show that surface transit networks are fractal in seven sub-districts of Strasbourg. Furthermore, a relationship was found between the length dimension and branch dimension of road network. The branch dimension of transit network was related not only to the length dimension of transit network but also to the branch dimension of road network. Based on the fractal information, the results suggest possible methods for designing good road and surface transit networks that are well-coupled in urban traffic planning. The implications for urban development are that some potential problems with regard to traffic network structure may exist if current situations are not coincident with some findings in this article.

A cellular automaton model is proposed to simulate mixed traffic flow composed of motor vehicles and bicycles near bus stops. Three typical types of bus stops which are common in China are considered in the model, including two types of curbside bus stops and one type of bus bay stops. Passenger transport capacity of three types of bus stops, which is applied to evaluate the bus stop design, is calculated based on the corresponding traffic flow rate. According to the simulation results, the flow rates of both motor vehicles and bicycles exhibit phase transition from free flow to the saturation one at the critical point. The results also show that the larger the interaction between motor vehicle and bicycle flow is near curbside bus stops, the more the value of saturated flows drops. Curbside bus stops are more suitable when the conflicts between two flows are small and the inflow rate of motor vehicles is low. On the contrary, bus bay stops should be applied due to their ability to reduce traffic conflicts. Findings of this study can provide useful suggestions on bus stop selection considering different inflow rate of motor vehicles and bicycles simultaneously.

Staggered working hours has the potential to alleviate excessive demands on urban transport networks during the morning and afternoon peak hours and influence the travel behavior of individuals by affecting their activity schedules and reducing their commuting times. This study proposes a multi-agent-based Q-learning algorithm for evaluating the influence of staggered work hours by simulating travelers’ time and location choices in their activity patterns. Interactions among multiple travelers were also considered. Various types of agents were identified based on real activity–travel data for a mid-sized city in China. Reward functions based on time and location information were constructed using Origin–Destination (OD) survey data to simulate individuals’ temporal and spatial choices simultaneously. Interactions among individuals were then described by introducing a road impedance function to formulate a dynamic environment in which one traveler’s decisions influence the decisions of other travelers. Lastly, by applying the Q-learning algorithm, individuals’ activity–travel patterns under staggered working hours were simulated. Based on the simulation results, the effects of staggered working hours were evaluated on both a macroscopic level, at which the space–time distribution of the traffic volume in the network was determined, and a microscopic level, at which the timing of individuals’ leisure activities and their daily household commuting costs were determined. Based on the simulation results and experimental tests, an optimal scheme for staggering working hours was developed.

Targeting eukaryotic proteins for deamidation modification is increasingly appreciated as a general bacterial virulence mechanism. Here, we present an atomic view of how a bacterial deamidase effector, cycle-inhibiting factor homolog in Burkholderia pseudomallei (CHBP), recognizes its host targets, ubiquitin (Ub) and Ub-like neural precursor cell expressed, developmentally down-regulated 8 (NEDD8), and catalyzes site-specific deamidation. Crystal structures of CHBP-Ub/NEDD8 complexes show that Ub and NEDD8 are similarly cradled by a large cleft in CHBP with four contacting surfaces. The pattern of Ub/NEDD8 recognition by CHBP resembles that by the E1 activation enzyme, which critically involves the Lys-11 surface in Ub/NEDD8. Close examination of the papain-like catalytic center reveals structural determinants of CHBP being an obligate glutamine deamidase. Molecular-dynamics simulation identifies Gln-31/Glu-31 of Ub/NEDD8 as one key determinant of CHBP substrate preference for NEDD8. Inspired by the idea of using the unique bacterial activity as a tool, we further discover that CHBP-catalyzed NEDD8 deamidation triggers macrophage-specific apoptosis, which predicts a previously unknown macrophage-specific proapoptotic signal that is negatively regulated by neddylation-mediated protein ubiquitination/degradation. [ABSTRACT FROM AUTHOR]

This paper analyzes the sudden abnormal gas outburst and its change during the initial mining period of the 2601 fully mechanized caving face in Zhangcun Coal Mine. It is proposed to use roof pre-cracking in the 2603 fully mechanized caving face to reduce the initial pressure step, and the inclination is high after drilling through the cut hole. Technical measures such as gas drainage in advance and increasing air supply with the increase of gas emission can eliminate the sudden abnormal gas outflow during the initial mining period, and completely solve the problem of gas exceeding the limit during the initial mining period of fully mechanized caving face. The following conclusions are drawn: the gas control technology system in the initial mining period, which is based on the back-inclined high-drainage roadway as the main body, is composed of roof pre-splitting, drilled through the cut hole, and increased air volume in the initial mining period. The sudden gas surge in the early stage solved the problem of gas overrun in the initial mining period.

Previous studies indicate that both Dectin-3 (also called MCL or Clec4d) and Mincle (also called Clec4e), two C-type lectin receptors, can recognize trehalose 6,6'-dimycolate (TDM), a cell wall component from mycobacteria, and induce potent innate immune responses. Interestingly, stimulation of Dectin-3 by TDM can also induce Mincle expression, which may enhance the host innate immune system to sense Mycobacterium infection. However, the mechanism by which Dectin-3 induces Mincle expression is not fully defined. Here, we show thatTDMinduced Mincle expression is dependent on Dectin-3-mediated NF-κB, but not nuclear factor of activated T-cells (NFAT), activation, and Dectin-3 induces NF-κB activation through the CARD9-BCL10-MALT1 complex. We found that bone marrowderived macrophages from Dectin-3-deficient mice were severely defective in the induction of Mincle expression in response to TDM stimulation. This defect is correlated with the failure of TDM-induced NF-κB activation in Dectin-3-deficient bone marrow-derived macrophages. Consistently, inhibition of NF-κB, but not NFAT, impaired TDM-induced Mincle expression, whereas NF-κB, but not NFAT, binds to the Mincle promoter. Dectin-3-mediated NF-κB activation is dependent on the CARD9-Bcl10-MALT1 complex. Finally, mice deficient for Dectin-3 or CARD9 produced much less proinflammatory cytokines and keyhole limpet hemocyanin (KLH)-specific antibodies after immunization with an adjuvant containingTDM.Overall, this study provides the mechanism by which Dectin-3 induces Mincle expression in response to Mycobacterium infection, which will have significant impact to improve adjuvant and design vaccine for antimicrobial infection. [ABSTRACT FROM AUTHOR]