An output‐feedback adaptive control architecture for mitigating actuator attacks in cyber‐physical systems

In this paper, we present a control design framework wherein an adaptive‐based corrective signal is augmented to the output of the nominal controller in order to suppress or counteract the effect of malicious actuator attacks. Due to the unavailability of full‐state measurements, a nonminimal controllable realization of the nominal closed‐loop system is used to design the corrective signal predicated on partial state information. Two illustrative numerical examples are given to demonstrate the efficacy of the proposed adaptive control architecture.     

Spatial estimation of aquifer’s hydraulic parameters by a combination of borehole data and inverse solution

Bulletin of Engineering Geology and the Environment - A combination of borehole data interpretation and inverse solution method used to estimate the spatial distribution of hydraulic conductivity...     

Potential of Ge-adopted Boron Nitride Nanotube as Catalyst for Sulfur Dioxide Oxidation

Protection of Metals and Physical Chemistry of Surfaces - In recent years, the discovery of efficient catalyst with low price to sulfur dioxide (SO2) oxidation in normal temperature is a major...     

Influence of fabrication stresses on fatigue life of friction stir welded aluminium profiles

Influence of clamping and welding procedure on fatigue life of a friction stir (FS) welded aluminium profile has been analysed. Two series of aluminium profiles (series A and B) have been fatigue tested. The different clamping conditions in series A and B gave rise to different failure positions that could not be explained neither by the effective notch stress method, nor by the critical distance methods. The clamping in series A introduced plastic deformation at the weld notch that gave rise to tensile residual stresses. The failure position could be explained from the value of the stress intensity factor provided that the residual stresses were considered.     

Microstructural Evolutions During Reversion Annealing of Cold-Rolled AISI 316 Austenitic Stainless Steel

Metallurgical and Materials Transactions A - Microstructural evolutions during reversion annealing of a plastically deformed AISI 316 stainless steel were investigated and three distinct stages...     

Carbon nanotube–polymer interactions in nanocomposites: A review

The interaction between carbon nanotubes and polymers is critically reviewed. The interfacial characteristics directly influence the efficiency of nanotube reinforcements in improving mechanical, thermal, and electrical properties of the polymer nanocomposite. In this review, various techniques of interaction measurements, including experimental and modelling studies, are described. From the experimental approaches, wetting, spectroscopy and probe microscopy techniques are discussed in detail. Molecular dynamics, coarse grain simulation and density functional theory are also explained as the main modelling approaches in interaction measurement studies. Different methods of interaction improvement, mainly categorized under covalent and noncovalent interactions, are described afterwards. Modelling predictions of nanocomposite properties, such as Young’s modulus, are compared with the experimental results in the literature and the challenges are discussed. Finally, it is concluded that an optimum carbon nanotube–polymer interaction is a key factor towards reaching the full potential of carbon nanotubes in nanocomposites.     

Interaction stresses in carbon nanotube-polymer nanocomposites

A new technique of atomic force microscopy interaction measurement is used to obtain the three-dimensional stress field in nanocomposites made of single-walled carbon nanotubes (SWNT) and poly(methyl methacrylate) (PMMA) matrix. This original approach expands the current capability of AFM from imaging and force mapping to three-dimensional stress field measurements. Latest developments in the field have been limited to three-dimensional imaging at the surface only, and one value (adhesion) force mapping. The current work provides the interaction stress results for a PMMA-SWNT nanocomposite and shows a maximum estimated load transfer of less than 7 MPa (the maximum attraction stress estimated). This value is obtained for an unfunctionalized nanocomposite and hence the interaction stress is mainly based on van der Waals interactions. This means that for this system, carbon nanotubes behave similar to an elastic-fully plastic material with a yield stress of less than 7 MPa. This phenomenon illustrates why carbon nanotubes may not show their strong mechanical properties (yield strength of above 10 GPa) in polymeric nanocomposites.     

离岸微型综合能源系统多目标随机规划

离岸微型综合能源系统与海洋工程的生产工艺环节结合紧密,并独立运行。因此,如何在克服生产工艺环节或外界环境不确定性影响的同时,尽可能减少CO_2的排放,并尽量节省成本是其规划的难点。文中从综合能源系统优化规划的角度,根据能源集线器的思想,建立离岸微型综合能源系统的电-热-CO_2耦合模型,构建以总成本最小、CO_2排放量最少为目标,以电、热网络平衡等条件为约束,并考虑生产工艺环节和外界环境不确定性影响的多目标随机规划模型,进而利用多目标进化算法求解该模型,实现兼顾成本与环保的离岸微型综合能源系统多目标优化规划。通过海上油气平台群及全电舰船的微型综合能源系统的优化规划,验证了所提方法的可行性与有效性。