Investigating boundary effects of congestion charging in a single bottleneck scenario

This paper investigates the impact of realistic congestion charging regimes whereundesired boundary effects of imposing charges may occur and may be bothtemporal and spatial. Tolling regimes are developed with the primary aim toreduce system cost (total travel time) whilst also aiming to reduce undesiredboundary effects. Two realistic toll profile regimes are investigated and tested;the first being flat tolls and the second bell-shaped tolls which represent step-tollsand their relative impact on the boundary effects are discussed. This paper theninvestigates the reduction of travel time which may be achieved by applyingdifferent toll levels to each link and compares the cases where all links may betolled against maintaining a single un-tolled route, which would be politicallyattractive. Existing DUE algorithms are utilised to obtain numerical results

Investigating boundary effects of congestion charging in a single bottleneck scenario

Many congestion charging projects charge traffic only within part of a day with predetermined congestion tolls. Demand peaks have been witnessed just around the time when the charge jumps up or down. Such peaks may not be desirable, in particular (a) when the resulting peaks are much higher than available capacities; (b) traffic speeding up to get into the charging zone causes more incidents just before the toll rises up to a higher level; or (c) traffic slowing down or parking on the roadside decreases road traffic throughput just before the toll falls sharply. We term these types of demand peaks ‘boundary effects’ of congestion charging. This paper investigates these effects in a bottleneck scenario and aims to design charging schemes that reduce undesired demand peaks. For this purpose, we observe and analyse the boundary effects utilising a bottleneck model under three types of toll profiles that are indicative of real charging schemes. The first type maintains a constant toll across the charging period, the second type allows the toll to increase from zero to a given maximum level and then decrease back to zero and the third type allows the toll to rise from zero to a given maximum level, remain at this level for a fixed period and then fall down to zero. This investigation shows that all three types of toll profiles can produce greater boundary peak demands than the bottleneck capacity. A significant contribution of this work is that instead of designing an optimal traffic congestion pricing scheme we analyse how existing sub-optimal congestion pricing schemes could be improved and suggest how observed problems may be overcome. Hence, we propose a set of extra requirements to supplement existing principles or requirements for design and implementation of congestion charging, which aim to reduce the adverse consequences of boundary effects. Concluding remarks are made on implications of this investigation for the improvement of existing congestion charging projects and for future research. First published online 13 July 201

A Decoupling Control Strategy for Multilayer Register System in Printed Electronic Equipment

Register accuracy is an important index to evaluate the quality of electronic products printed by gravure printed electronic equipment. However, the complex relationships of multilayer register system make the problem of decoupling control difficult to be solved, which has limited the improvement of register accuracy for the gravure printed electronic equipment. Therefore, this paper presents an integrated decoupling control strategy based on feedforward control and active disturbance rejection control (ADRC) to solve the strong coupling, strong interference, and time-delay problems of multilayer register system. First of all, a coupling and nonlinear model is established according to the multilayer register working principle in gravure printing, and then a linear model of the register system is derived based on the perturbation method. Secondly, according to the linear model, a decoupling control strategy is designed based on feedforward control and ADRC for the multilayer register system. Finally, the results of computer simulation show that the proposed control methodology can realize a decoupling control and has good control performance for multilayer register system

Investigating boundary effects of congestion charging in a single bottleneck scenario

This paper investigates the impact of realistic congestion charging regimes whereundesired boundary effects of imposing charges may occur and may be bothtemporal and spatial. Tolling regimes are developed with the primary aim toreduce system cost (total travel time) whilst also aiming to reduce undesiredboundary effects. Two realistic toll profile regimes are investigated and tested;the first being flat tolls and the second bell-shaped tolls which represent step-tollsand their relative impact on the boundary effects are discussed. This paper theninvestigates the reduction of travel time which may be achieved by applyingdifferent toll levels to each link and compares the cases where all links may betolled against maintaining a single un-tolled route, which would be politicallyattractive. Existing DUE algorithms are utilised to obtain numerical results

Ru Nanoparticles Supported on MIL-101 by Double Solvents Method as High-Performance Catalysts for Catalytic Hydrolysis of Ammonia Borane

Highly dispersed crystalline Ru nanoparticles (NPs) were successfully immobilized inside the pores of MIL-101 by a double solvents method (DSM). HRTEM clearly demonstrated the uniform distribution of the ultrafine Ru NPs throughout the interior cavities of MIL-101. The synthesized Ru@MIL-101 catalyst was also characterized by X-ray diffraction (XRD), N2 adsorption desorption, and ICP-AES. The catalytic test indicated that the Ru NPs supported MIL-101 material exhibited exceedingly high activity and excellent durability for hydrogen generation from the catalytic hydrolysis of amine boranes

Enhanced removal of cephalexin and sulfadiazine in nitrifying membrane-aerated biofilm reactors

Nitrification process has been reported to be capable of degrading various pharmaceuticals due to the cometabolism of ammonia-oxidizing bacteria (AOB). The membrane aerated biofilm reactor (MABR) is an emerging configuration in wastewater treatment with advantages of high nitrification rate and low energy consumption. However, there are very few studies investigating the degradation of antibiotics at environmentally relevant levels in nitrifying MABR systems. In this study, the removal of two widely used antibiotics, cephalexin (CFX) and sulfadiazine (SDZ), was evaluated in two independent MABRs with nitrifying biofilms. The impacts of CFX and SDZ exposure on the nitrification performance and microbial community structure within biofilms were also investigated. The results showed that nitrifying biofilms were very efficient in removing CFX (94.6%) and SDZ (75.4%) with an initial concentration of 100 μg/L when hydraulic retention time (HRT) was 4 h in the reactors. When HRT decreased from 4 h to 3 h, the removal rates of CFX and SDZ increased significantly from 23.4 ± 1.0 μg/(L·h) and 18.7 ± 1.1 μg/(L·h), respectively, to 27.7 ± 1.3 μg/(L·h) (p＜0.01) and 20.8 ± 2.4 μg/(L·h) (p＜0.05), while the removal efficiencies decreased to 86.0% and 61.5%, respectively. Despite the exposure to CFX and SDZ, the nitrification performance was not affected, and microbial community structure within biofilms also remained relatively stable. This study shows that nitrifying MABR process is a promising option for the efficient removal of antibiotics from domestic wastewater

A Broadband Spectrum Sensing Algorithm in TDCS Based on ICoSaMP Reconstruction

In order to solve the problem that the wideband compressive sensing reconstruction algorithm cannot accurately recover the signal under the condition of blind sparsity in the low SNR environment of the transform domain communication system. This paper use band occupancy rates to estimate sparseness roughly, at the same time, use the residual ratio threshold as iteration termination condition to reduce the influence of the system noise. Therefore, an ICoSaMP(Improved Compressive Sampling Matching Pursuit) algorithm is proposed. The simulation results show that compared with CoSaMP algorithm, the ICoSaMP algorithm increases the probability of reconstruction under the same SNR environment and the same sparse degree. The mean square error under the blind sparsity is reduced

Competition between Li2Se2Sx conversion and Li Ion transport on graphene surface coordination doped with transition metal and N

The shuttling of polyselenide (Li2Se2Sx) was prevented effectively by building a separator in Li-SexSy batteries. Nitrogen atoms are used to coordinate transition metal (TM=Ti, Zr, V) co-doped graphene to restrict the free shuttling of polylithium selenide (Li2Se2Sx, x = 1–6) through physical confinement and chemical adsorption. The nitrogen (N) atom assisted transition metal co-doped graphene surface to build a model of strong adsorption of cations and anions on lithium-sulfur-selenium compounds to inhibit the shuttle phenomenon. Nitrogen atoms are not only coordinately doped with transition metals, but also lithium atoms can easily form bonds to improve the adsorption strength of Li2Se2Sx on the graphene surface. The evolution of the N-type to P-type adsorption model of Li2Se2Sx on the graphene co-doped Ti-N-G surface to the Zr-N-G surface was constructed based on the phenomenon of Fermi level changes strong adsorption capacity and immobilization. The Fermi energy level of the V-N-G weak adsorption catalytic model was located between the valence and conduction bands. The doping of N and TM improves the ionic conductivity of graphene, which adsorbs Li2Se2Sx and causes a high Li diffusion barrier. A coupled physical model of ion transport and polyselenide conversion was built by adjusting the Fermi level of separator

Achieving simultaneous nitrogen and antibiotic removal in one-stage partial nitritation-Anammox (PN/A) process

Partial nitritation-Anammox (PN/A) process has been recognized as a sustainable process for biological nitrogen removal. Although various antibiotics have been ubiquitously detected in influent of wastewater treatment plants, little is known whether functional microorganisms in the PN/A process are capable of biodegrading antibiotics. This study aimed to investigate simultaneous nitrogen and antibiotic removal in a lab-scale one-stage PN/A system treating synthetic wastewater containing a widely-used antibiotic, sulfadiazine (SDZ). Results showed that maximum total nitrogen (TN) removal efficiency of 86.1% and SDZ removal efficiency of 95.1% could be achieved when treating 5 mg/L SDZ under DO conditions of 0.5–0.6 mg/L. Compared to anammox bacteria, ammonia-oxidizing bacteria (AOB) made a major contribution to SDZ degradation through their cometabolic pathway. A strong correlation between amoA gene and SDZ removal efficiency was found (p < 0.01). In addition, the degradation products of SDZ did not exhibit any inhibitory effects on Escherichia coli. The findings suggest that it is promising to apply the PN/A process to simultaneously remove antibiotics and nitrogen from contaminated wastewater