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In this paper, we preliminarily propose the dissipative sliding mode control (SMC) scheme for polyhedral singular semi-Markov jump linear parameter varying (SS-MJLPV) systems considering deception attacks between the sensor and controller. The main feature of this scheme is that a novel developed parameter dependent integral-type SMC law follows the changes of the system. Note that the mode of the sliding mode controller is not synchronized with the system mode, and the transition rates (TRs) of the system are assumed to be unknown. Moreover, we extend the previous work concerning the static event-triggered transmission protocol (ETP) to the dynamic one, in which the triggering threshold is dynamically updated via the internal-dynamic-variable. Finally, a DC-motor model is presented to illustrate the correctness of the developed results.

Silicon photonics is rapidly evolving as an advanced chip framework for implementing quantum technologies.

Wearable strain sensors have drawn massive awareness in various studies and industrial fields.

It is proven that introduction of graphene into typical heterostructures can effectively reduce the high interfacial thermal resistance in semiconductor chips. The crystallinity of graphene varies greatly; thus, we have investigated the effects of single-crystal and polycrystalline graphene on the thermal transport of AlN/graphene/3C-SiC heterostructures by molecular dynamics. The results show that polycrystalline graphene contributes more to the interfacial thermal conductance (ITC) inside the chip with a maximum increase of 75.09%, which is further confirmed by the energy transport and thermal relaxation time. Multiple analyses indicate that grain boundaries lead to the increase in C-Si covalent bonds, and thus, strong interactions improve the ITC. However, covalent bonding further causes local tensile strain and wrinkles in graphene. The former decreases the ITC, and the latter leads to the fluctuation of the van der Waals interaction at the interface. The combined effect of various influential factors results in the increase in the ITC, which are confirmed by phonon transmission with 0-18 THz. In addition, wrinkles and covalent bonding lead to increased stress concentration in polycrystalline graphene. This leads to a maximum reduction of 19.23% in the in-plane thermal conductivity, which is not conducive to the lateral diffusion of hot spots within the chip. The research results would provide important guidance in designing for high thermal transport performance high-power chips.

To improve the anti-sticking performance of tire molds, six types of coatings (i.e., nano-ceramic coating, bilayer waterborne polytetrafluoroethylene (PTFE) coating, fluorinated ethylene propylene (FEP)-based Whitford coating, PTFE, FEP, and perfluoroalkoxy (PFA) aqueous dispersions) were selected to modify type-45 steel specimens by air spraying. Their wettability, microstructure, demolding force, and anti-fouling properties in rubber vulcanization tests were studied. The results show that the demolding forces of the coatings were at least 24% lower than that of uncoated surface. Whitford coating, PFA, and FEP coatings had zero demolding force and no pollutant residue. PTFE coating had no pollutant residue but had high demolding force. The other two coatings had poor anti-sticking property. Upon combining the surface morphology and chemical composition analysis results, the coating demolding force was related to the surface micro-morphology: smoother surfaces led to lower demolding forces, while the surface chemical composition had a direct influence on the rubber contaminant residual. The C–F bonds on the surfaces resulted in less rubber residual due to intrinsic low surface energy. X-ray photoelectron spectrometry (XPS) analysis showed that ZnS was one of the main pollutants after rubber vulcanization test.

The purpose of this study was to explore the anti-inflammatory mechanism of walnut peptide LPF in the LPS-induced RAW264.7 cells model. The walnut peptide LPF down-regulated the phagocytic ability and the production of nitric oxide (NO) induced by LPS-stimulated RAW264.7. Molecular docking analysis showed that the walnut peptide LPF can bind into the active pocket of inducible nitric oxide synthase (iNOS) with high affinity. Further, the mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumour necrosis factor-α (TNF-α) were suppressed by the walnut peptide LPF intervention. Later, we validated the under-expression of INOS protein by western blot. The decreased mRNA expression of IκB-α demonstrated the anti-inflammatory effects of the walnut peptide LPF were related to the regulation of the NF-κB signalling pathway. Our results suggest that the walnut peptide LPF has the potential to be developed as a functional food ingredient against inflammation.

Controlled self-assembly of plasmonic photonic nanostructures provides a cost-effective and efficient methodology to expand plasmonic photonic nano-platforms with unique, tunable, and coupled optical characteristics. Keeping advantages and challenges in view, this review highlights contemporary advancements towards the development of self-assembly of a plasmonic photonic nanostructure using a colloidal solution and a self-assembly modeling technique along with exploring novel optical properties and associated prospects. The potential applications of self-assembled plasmonic photonic nano-systems to investigate next-generation optoelectronic devices, the need to reduce and increase scaling up aspects, and improve the performance, are also covered briefly in the review. The need of considerable efforts for the design and development towards establishing novel cost-effective methods to fabricate controlled self-assembled smart nano-plasmonic platforms is also highlighted in this mini-review. Key confronting issues that precisely limit the self-assemblies of photonic nanostructures and desired integration with other device components, mainly including uniformity within miniaturized devices are also discussed. This review will serve as a guideline and platform to plan advanced research in developing self-assembled plasmonic photonic nano-systems to investigate smart functional optical devices.

Bacterial biofilms formed on touchable surfaces such as displays of electronic devices not only reduce the product service life, but also cause human health issues. There is an urgent need to research the biofilm formation mechanism and methodologies to prevent formation of biofilms on human touchable surfaces. It has been reported that laser-induced graphene (LIG) helps resist biofilm growth, which has been attributed to the atomic composition and sharp edges of graphene. However, LIG alone was not able to retard bacterial growth completely. It has been reported that LIG incorporated with silver (Ag) nanoparticles exhibited enhanced surface antibacterial activity. As a heavy metal, overdose of Ag is harmful to human health. Therefore, a new biocompatible antibacterial agent to replace or reduce the use of Ag is highly important. In this study, we investigate and compare the effect of LIG doped with two types of nanocrystals, i.e., ZnO and silver (Ag)-doped ZnO, on antibacterial actions. A 355 nm ultraviolet (UV) laser was used to produce LIG on a watercolor paper substrate. Formation of few-layer graphene has been verified by Raman spectra. Escherichia coli (E. coli), a representative of Gram-negative bacteria and Staphylococcus aureus (S. aureus), a representative of Gram-positive bacteria were employed for the investigation of the bacteriostatic properties of the LIG paper substrate. Results show that with the incorporation of either the ZnO nanocrystals or the silver (Ag)-doped ZnO nanocrystals into LIG, the antibacterial effect became stronger. It is further shown that the Ag-doped ZnO nanocrystals have superior antibacterial performance to that of the ZnO nanocrystals. The Ag-doped ZnO nanocrystals are potentially an effective and biocompatible antibacterial agent and yet have a much reduced and acceptable level of Ag concentration.

Nowadays, high-entropy alloys (HEAs) have become a hot research topic in the field of coating materials. However, HEAs have a large wide range of compositional systems, and the differences in their composition inevitably lead to the significant variations in the matching process parameters of laser cladding and post-treatment methods, which in turn give the coatings a broad range of microstructures and protective properties. Therefore, it is crucial to review and summarize the research progresses on laser cladding HEA coatings to provide a reference for obtaining high-performance HEA coatings and further expand the application of HEA coatings. This work describes the working mechanism of laser cladding and illustrates the advantages and drawbacks of laser cladding in detail. The effects of the addition of alloying elements, process parameters and post-treatment techniques on the microstructures and properties of the coatings are thoroughly reviewed and analyzed. In addition, the correlations between the chemical compositions of HEAs, process parameters of laser cladding, post-treatment techniques and the microstructure and protective properties of the coatings are investigated and summarized. On this basis, the future development direction of HEA coatings is outlined.

The self-assembled plasmonic nano-enabled photonic crystals (PCs)have been studied as promising platforms to develop next-generation photonic and opto-electronic devices. In this review, we attempt to describe the fundamentals of self-assembled colloidal plasmonic nanostructures and various applications of such devices. Different important aspects, such as interaction between metal NPs (MNPs) and non-metal 3-D crystals, effect of NPs on the spectral properties of materials, the mechanism of plasmonic based PCs, and related challenges and their possible solutions have been demonstrated crucially. The advancements in the self-assembly based plasmonic PCs and their applications are discussed carefully. We believe that nano-enabled self-assembled plasmonic crystals are better candidates of nanostructures to advance photonic technologies with reduced form factor and high performance.

In this research article, we reportthe plasmonic effect exhibited by a self-assembled photonic crystal cavity in nanostructures using asecond harmonic laser exposure. The photonic nanostructures composed of goldnanoparticles (AuNPs),enhancedthe fluorescence properties which undergo into lattice planesand thereby affect thenonlinearproperties.The newlyfabricated colloidal structures exhibited a strong plasmonicinteraction with different laser powersdensity.The outcome of this research presentsthe self-assembled nano-photonic cavity as a suitable plasmonic nanostructure for optoelectronic applications. These nanostructurescan be fabricated using high power lasers source,e.g. dye laser and solid-state laser.

High-performance engineering alloys, such as 7000 series aluminum alloys, suffer poor printability in laser powder bed fusion (LPBF) additive manufacturing. An enormous challenge lies in the suppression of solidification cracks caused by solidification shrinkage and thermal stresses. Porosity formation, as one of the main concerns for LPBF application, should also be avoided at the same time. In this study, aluminum alloy (AA) 7075 with and without Zr modification was additively manufactured by LPBF. Processing parameters of laser power and scanning speed, resulting in various volumetric energy density (VED), were experimentally determined to produce crack-free components with tailored microstructure. Optical microscopy was used to reveal how the crack density and porosity vary with VED. Scanning electron microscopy and transmission electron microscopy uncovered the detailed microstructure in the molten pool and the evolution of the elemental Zr addition. The results indicate that 1 w.t.% addition of elemental Zr in AA7075 led to lower crack density compared with 0.3 w.t.% addition. In 1 w.t.% Zr-modified AA7075, crack-free components were obtained under high VED. Fine equiaxed grains, instead of large columnar grains, were formed at the bottom of the molten pool boundary due to the existence of Al3Zr compound, which favored the nucleation of aluminum grains and elimination of cracks. The phenomenon of silicon segregation near cracks remained in Zr modified alloys, although its effects on cracking were suppressed. Spherical pores in the Zr-modified AA7075 increased due to the deterioration of fluidity by unmelted particles, which distracted the Marangoni flow as well. Sufficient laser energy input can increase the viscosity and ease the pores escaping. By optimizing parameters, crack-free AA7075 parts with low porosity can be manufactured through LPBF with Zr addition.

A thorough experimental investigation of polymer-glass transition temperature (T

Walnut peptides have been reported to exhibit diverse activities. In this study, we investigated the protective and recovery effects of the walnut derived peptide leucine-proline-phenylalanine (LPF) on dextran sulfate sodium (DSS)-induced colitis in mice. The peptide LPF mitigated the severity of symptoms during the development phase of colitis, as evidenced by changes in body weight, disease activity index score, and serum inflammatory cytokine levels. Moreover, the treatment groups showed beneficial effects, including increased colon length, reduced colonic cell apoptosis, decreased production of inflammatory factors, and expansion of splenic regulatory T cells during the recovery period. Additionally, 16S rDNA sequencing results indicated that 100 mg/kg LPF (M group) reversed the dysbiosis of gut microbiota in colitis mice. This included partial recovery of diversity of microbiota, increase in relative abundance of the family Lachnospiraceae and Ruminococcaceae during the development phase of colitis. Additionally, the composition of gut microbiota in the M group was constantly improved during the recovery period of colitis, showing increased relative abundance of beneficial genera and decreased abundance of potentially harmful genera compared with that in the DSS group. In summary, the peptide LPF could contribute to remission of colitis symptoms and restoration through reduction in cell apoptosis, anti-inflammatory effects, and regulation of gut microbiota.

Self-powered devices and micro-sensors are in high demand for intelligent electronics and flexible wearables for applications in medical healthcare and human–computer interactive robotics. Flexible, stretchable, wearable and breathable high-sensitivity sensors that monitor signals from subtle changes in the environment provide solutions for personalized medical healthcare. In this article, we review the fundamental mechanisms, theoretical research, sensor fabrication methodologies, and applications of flexible piezoelectric materials. We focus on the flexibility and stretchability of inorganic, polymer, and bio-piezoelectric materials, explain their properties for physiological signal monitoring, motion detection, and force sensing. We provide an overview of the latest progress in piezoelectronics and piezoelectric photonics, the structures of devices, and self-powering technologies. We compared 10 types of polymers and composites with human skin in terms of elastic modulus and found that PLLA/PDMS, electro-spun PVDF, and ZnO/PVDF possess higher elastic modulus (50, 500, and 27900 MPa respectively) than human skin (18.8 MPa), thus being more suitable for wearable devices. In terms of electrical outputs of piezoelectric materials, polarized cast film has stronger piezoelectric property with output of 14–45.6 V than electro-spun filaments material (output 0.4–9 V). Future research and development should focus on increasing electrical performance while maintaining the required flexibility and durability.

Modern control methods like optimal control and model predictive control (MPC) provide a framework for simultaneous regulation of the tracking performance and limiting the control energy, thus have been widely deployed in industrial applications. Yet, due to its simplicity and robustness, the conventional P (Proportional) and PI (Proportional-Integral) control are still the most common methods used in many engineering systems, such as electric power systems, automotive, and Heating, Ventilation and Air Conditioning (HVAC) for buildings, where energy efficiency and energy saving are the critical issues to be addressed. Yet, little has been done so far to explore the effect of its parameter tuning on both the system performance and control energy consumption, and how these two objectives are correlated within the P and PI control framework. In this paper, the P and PI controllers are designed with a simultaneous consideration of these two aspects. Two case studies are investigated in detail, including the control of Voltage Source Converters (VSCs) for transmitting offshore wind power to onshore AC grid through High Voltage DC links, and the control of HVAC systems. Results reveal that there exists a better trade-off between the tracking performance and the control energy through a proper choice of the P and PI controller parameters.

The buildings in tropical climate like Singapore get excessive heat gain throughout the year. Passive cooling can be achieved with IR-shielding coating by blocking the IR radiation from solar light. In this work, antimony-doped tin oxide (ATO) nanocrystals with diameter of 10 nm were synthesized by solvothermal method. The Sb dopant concentration in ATO nanoparticles was optimized towards enhanced IR shielding properties. Sol–gel precursor was formulated with silanes and ATO nanocrystals. Transparent IR shielding coatings were coated on glass for smart window. The optical and IR shielding performance of the coatings were evaluated. By incorporating smaller ATO nanocrystals synthesized by solvothermal synthesis, the IR shielding performance of the coating was greatly improved as compared to that using larger commercial ATO nanoparticles. The IR shielding coating with synthesized ATO nanocrystals can block more than 90% IR while it can maintain more than 80% transmittance at the visible range. The solar heat gain coefficient (SHGC or G-value) of the coating with 10 wt.% synthesized ATO nanocrystals is 0.68 for single layer structure, and decreases to 0.53 with double glazing structure while maintaining good visible transmittance of 60%. Keywords: Solvothermal, ATO, IR shielding coating, Smart window

In this paper, sol–gel-based transparent easy-to-clean (ETC) coatings are fabricated using organic–inorganic hybrid precursors and fluorinated silane-based hydrophobic surfactants. ETC coatings were applied on different plastic materials such as polycarbonate, poly(methyl methacrylate) and polyethylene terephthalate. Due to the low temperature resistance of the plastic materials, usually lower than 120 °C, low temperature processes such as ammonia gas curing and ultraviolet irradiation curing were employed for coatings development. Alumina nanoparticles were used to improve the mechanical properties of the coatings, and antimicrobial effect was realized by incorporation of silver nanoparticles, and high bacterial killing rates were obtained with very low silver concentration (50 ppm). All the coatings developed on different substrates show high water/hexadecane contact angles with good wet scrubbing resistance. Abrasion-resistant multifunctional sol–gel coating on PMMA substrate

Among various technologies to tackle the twin challenges of sustainable energy supply and climate change, energy saving through advanced control plays a crucial role in decarbonizing the whole energy system. Modern control technologies, such as optimal control and model predictive control do provide a framework to simultaneously regulate the system performance and limit control energy. However, few have been done so far to exploit the full potential of controller design in reducing the energy consumption while maintaining desirable system performance. This paper investigates the correlations between control energy consumption and system performance using two popular control approaches widely used in the industry, namely the PI control and subspace model predictive control. Our investigation shows that the controller design is a delicate synthesis procedure in achieving better trade-off between system performance and energy saving, and proper choice of values for the control parameters may potentially save a significant amount of energy.

In this paper, a new online proportional-integral-derivative (PID) controller parameter optimisation method is proposed by incorporating the philosophy of the model predictive control (MPC) algorithm. The future system predictive output and control sequence are first written as a function of the controller parameters. Then PID controller design is realised through optimising the cost function under the constraints on the system input and output. The MPC based PID online tuning easily handles the constraints and time delay. Simulation results in three situations, changing the control weight, adding constraints on the overshoot and control signal and changing the reference value, confirm that the proposed method is capable of producing good tracking performance with low energy consumption and short settling time.

Star-like polyurethane (PU) hybrid films containing octafunctional cubic silsesquioxanes are prepared by polyaddition reaction between octakis(dimethylsilyloxy) silsesquioxane isopropenyldimethylbenzyl isocyanate (OS-PDBI) and octakis(dimethylsilyloxy) hydroxypropyl silsesquioxane (HPS); and between OS-PDBI and hexane diol (HD). The effect of incorporation of nanostructured cubic silsesquioxanes (CSSQ) on the macroscopic properties of PU film and their thermomechanical properties are investigated. The obtained hybrid films are relatively transparent. Their morphologies and properties are studied by using Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), thermogravimetry (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and contact angle measurements. The formation of urethane linkage disrupts the three-dimensional ordered structure of CSSQ in the hybrid film. AFM images show clearly that no phase separation in the macroscopic level for both PU hybrid films. TGA and DMA analyzes indicate that the incorporation of octafunctional silsesquioxane in PU hybrid film provides enhanced thermal stability and increased crosslink density. Moreover, the existence of cage structure also improves oxidation resistance and mechanical strength. The incomplete reaction between OS-PDBI and HPS due to the steric hindrance of highly branched rigid CSSQ could result in a slight decrease in initial decomposition temperature. Furthermore, hardness and out-of-plane compressive modulus are also investigated by nanoindentation.

We measured the Raman spectra of canthaxanthin which contains 9 CC conjugated double bonds in nonpolar solvent carbon disulfide under different pressures. The results showed that the Raman scattering cross section (RSCS) for C C and C C stretching vibration bands of canthaxanthin first increase and then decrease with the increase of pressure. We assume that the main mechanism of the RSCS values increasing can be attributed to the effect of steric hindrance. And the liquid–solid phase transition of carbon disulfide is occurred under the 0.5312 GPa, which lead to the decrease of RSCS values.