Lina Qiu, Yanan Mao, Aijun Gong, Weiwei Zhang, Yanqiu Cao and Lu Tong
Bdellovibrio bacteriovorus is a gram-negative predatory bacterium which can potentially inhibit microbiologically influenced corrosion by preying on sulfate-reducing bacteria…
Abstract
Purpose
Bdellovibrio bacteriovorus is a gram-negative predatory bacterium which can potentially inhibit microbiologically influenced corrosion by preying on sulfate-reducing bacteria (SRB). However, no researches about the inhibition are reported according to the authors’ knowledge. The purpose of this paper was to investigate the Inhibition effect of B. bacteriovorus on the corrosion of X70 pipeline steel induced by SRB.
Design/methodology/approach
The effect of B. bacteriovorus on the growth of SRB was studied by measuring the optical density at 600 nm (OD600) and sulfate concentration in culture medium. X70 pipeline steel was used as the test material to investigate the anti-corrosion effect of B. bacteriovorus on SRB by conducting electrochemical analysis (including Tafel polarization curves and electrochemical impendence spectroscopy) and weight loss measurement.
Findings
B. bacteriovorus could inhibit the growth of SRB in culture medium by its predation on SRB, which led to decrease of OD600 value and increase of sulfate concentration. The results of electrochemical analysis indicated that B. bacteriovorus had positive inhibition efficiencies on SRB-induced corrosion of X70 pipeline steel. Moreover, corrosion rate of X70 pipeline steel was declined from 19.17 to 3.75 mg·dm-2·day-1 by the presence of B. bacteriovorus.
Originality/value
This is the first report about using B. bacteriovorus to inhibit the corrosion induced by SRB. Compared to other anti-corrosion methods, the microbial inhibition methods exhibit more considerable application value due to its low cost, high efficiency and non-pollution.
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Lina Qiu, Jin Tian, Weiwei Zhang, Aijun Gong and Weiyu Zhao
Sulfate-reducing bacteria (SRB) are recognized by scholars as the most important class of bacteria leading to corrosion of metal materials. It is important to use the properties…
Abstract
Purpose
Sulfate-reducing bacteria (SRB) are recognized by scholars as the most important class of bacteria leading to corrosion of metal materials. It is important to use the properties of microorganisms to inhibit the growth of SRB in the corrosion protection of metal materials and to protect the environment.
Design/methodology/approach
In this work, the behavior of anaerobic Thiobacillus denitrificans (TDN) intracellular enzyme inhibition of SRB corrosion of EH36 steel was investigated with electrochemical impedance spectroscopy, biological detection technology and X-ray photoelectron spectroscopy.
Findings
Results showed that the SRB crude intracellular enzyme affected the corrosion behavior of EH36 steel greatly and the purified TDN intracellular enzyme inhibits SRB intracellular enzyme corrosion to EH36 steel.
Originality/value
A perfect enzyme activity inhibition mechanism will provide theoretical guidance for the selection and application of anticorrosion microorganisms, which is of scientific significance in the field of microbial anticorrosion research.
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Abstract
Purpose
The promotion of new energy vehicles (EVs) is an effective way to achieve low carbon emission reduction. This paper aims to investigate the optimal pricing of automotive supply chain members in the context of dual policy implementation while considering consumers' low-carbon preferences.
Design/methodology/approach
This article takes manufacturers, retailers and consumers in a main three-level supply chain as the research object. Stackelberg game theory is used as the theoretical guidance. A game model in which the manufacturer is the leader and the retailer is the follower is established. The author also considered the impact of carbon tax policies, subsidy policies and consumer preferences on the results. Furthermore, the author investigates the optimal decision-making problem under the profit maximization model.
Findings
Through model solving, it is found that the pricing of EVs is positively correlated with the unit price of carbon and the amount of subsidies. The following conclusions can be obtained by numerical analysis of each parameter. Changes in carbon prices have a greater impact on conventional gasoline vehicles. Based on the numerical analysis of parameter β, it is also found that when the government subsidizes consumers, supply chain members will increase their prices to obtain partial subsidies. Compared with retailers, low-carbon preferences have a greater impact on manufacturers.
Research limitations/implications
The new energy automobile industry involves many policies, including tax cuts, tax exemptions and subsidies. The policy environment faced by the members of a supply chain is complex and diverse. Therefore, the analysis in this article is based only on partial policies.
Originality/value
The authors innovatively combine the three factors of subsidy policy, carbon tax policy and consumer low-carbon preference, with research on the pricing of EVs. The influence of policy factors and consumer preferences on the pricing of EVs is studied.
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Mati Ullah, Chunhui Zhao and Hamid Maqsood
The purpose of this paper is to design a hybrid robust tracking controller based on an improved radial basis function artificial neural network (IRBFANN) and a novel…
Abstract
Purpose
The purpose of this paper is to design a hybrid robust tracking controller based on an improved radial basis function artificial neural network (IRBFANN) and a novel extended-state observer for a quadrotor system with various model and parametric uncertainties and external disturbances to enhance the resiliency of the control system.
Design/methodology/approach
An IRBFANN is introduced as an adaptive compensator tool for model and parametric uncertainties in the control algorithm of non-singular rapid terminal sliding-mode control (NRTSMC). An exact-time extended state observer (ETESO) augmented with NRTSMC is designed to estimate the unknown exogenous disturbances and ensure fast states convergence while overcoming the singularity issue. The novelty of this work lies in the online updating of weight parameters of the RBFANN algorithm by using a new idea of incorporating an exponential sliding-mode effect, which makes a remarkable effort to make the control protocol adaptive to uncertain model parameters. A comparison of the proposed scheme with other conventional schemes shows its much better performance in the presence of parametric uncertainties and exogenous disturbances.
Findings
The investigated control strategy presents a robust adaptive law based on IRBFANN with a fast convergence rate and improved estimation accuracy via a novel ETESO.
Practical implications
To enhance the safety level and ensure stable flight operations by the quadrotor in the presence of high-order complex disturbances and uncertain environments, it is imperative to devise a robust control law.
Originality/value
A new idea of incorporating an exponential sliding-mode effect instead of conventional approaches in the algorithm of the RBFANN is used, which makes the control law resistant to model and parametric uncertainties. The ETESO provides rapid and accurate disturbance estimation results and updates the control law to overcome the performance degradation caused by the disturbances. Simulation results depict the effectiveness of the proposed control strategy.
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Ajeet Kumar Bhatia, Jiang Ju, Zhen Ziyang, Nigar Ahmed, Avinash Rohra and Muhammad Waqar
The purpose of this paper is to design an innovative autonomous carrier landing system (ACLS) using novel robust adaptive preview control (RAPC) method, which can assure safe and…
Abstract
Purpose
The purpose of this paper is to design an innovative autonomous carrier landing system (ACLS) using novel robust adaptive preview control (RAPC) method, which can assure safe and successful autonomous carrier landing under the influence of airwake disturbance and irregular deck motion. To design a deck motion predictor based on an unscented Kalman filter (UKF), which predicts the touchdown point, very precisely.
Design/methodology/approach
An ACLS is comprising a UKF based deck motion predictor, a previewable glide path module and a control system. The previewable information is augmented with the system and then latitude and longitudinal controllers are designed based on the preview control scheme, in which the robust adaptive feedback and feedforward gain’s laws are obtained through Lyapunov stability theorem and linear matrix inequality approach, guarantying the closed-loop system’s asymptotic stability.
Findings
The autonomous carrier landing problem is solved by proposing robust ACLS, which is validated through numerical simulation in presence of sea disturbance and time-varying external disturbances.
Practical implications
The ACLS is designed considering the practical aspects of the application, presenting superior performance with extended robustness.
Originality/value
The novel RAPC, relative motion-based guidance system and deck motion compensation mechanism are developed and presented, never been implemented for autonomous carrier landing operations.