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Miljøproblemer som globaloppvarming har lenge vært et stort problem. Bærekraftige materialer blir derfor ønsket for å tilpasse strengere klimamål. Hybridelementer er et av de byggevarene som bidrar til å minske klimagassutslipp og samtidig tilbyr de like gode mekaniske egenskaper. Mekanismen til hybridelementene er å kombinere to eller flere materialer og drar nytter fra hvert materiale. Det sørger for at ressursene blir benyttet på en optimal måte. Aluminiumlegering har lav vekt, høy korrosjonsbestandighet og høy styrke i forhold til sin lave vekt. LVL er et trebasert konstruksjonselement med høy bærende evne. Den er miljøvennlig og lett å forme. Hybridbjelken som består av de to materialene, kan derfor være en bærekraftig løsning for fremtiden. Denne oppgaven analyserer numerisk hvordan endring av stivhet oppstår når tykkelse på deler av hybridbjelken endrer seg. Effekten av bolteforbindelse er også undersøkt. Oppgaven har tatt fokus på tolkning av ultimate nedbøying i midten av hybridbjelken og glidning mellom delene av hybridbjelken. Numerisk analyse er gjort ved hjelpe av tredimensjonale modeller bygd i Ansys Mechanical APDL 2022 R1 som benytter elementmetode. Modellen blir verifisert ved å sammenligne resultater fra en eksperimentell bøyetest. Både elastiske og plastiske materialegenskaper har blitt definert. LVL anses som et ortotropt materiale og aluminiumlegering som et isotropt materiale. Resultater fra analysene viser at numeriske modeller kan simulere eksperimenter med lite avvik. Nøyaktigheten av modeller kan justeres ved å endre innebygde parametere i Ansys etter behov. En tykkere LVL-bjelke vil bidra til en stivere hybridbjelke, men det øker også glidingen fra aluminiumbjelken. Det gir en stiv forbindelse med 66 bolter og kan forbedres ved å øke boltantallet, men det anbefales ikke å redusere flere bolter. Stivhetsendring er lite signifikant når tykkelse av steget på aluminiumbjelke er forandret og gir derimot større glidning. Generelt har hybridbjelken av LVL og aluminiumlegering har høy stivhet i forhold til sin lave vekt og er korrosjonsbestandige. Den kan være et godt alternativ til tradisjonelle byggematerialer. Environmental problems such as global warming have long been a major problem. Sustainable materials are therefore desired to adapt to stricter climate targets. Hybrid elements are one of the construction elements that help reduce greenhouse gas emissions and at the same time offer equally good mechanical properties. The mechanism of the hybrid elements is to combine two or more materials and benefits from each material. It ensures that resources are used in an optimal way. Aluminium alloy has low weight, high corrosion resistance and high strength in relation to its low weight. LVL is a wood-based construction element with a high load-bearing capacity. It is environmentally friendly and easy to shape. The hybrid beam, which consists of the two materials, can therefore be a sustainable solution for the future. This assignment numerically analyzes how changes in stiffness occur when the thickness of parts of the hybrid beam changes. The effect of bolted connection has also been investigated. The assignment has focused on interpretation of ultimate deflection in the middle of the hybrid beam and slip between the parts of the hybrid beam. Numerical analysis is done with the help of three-dimensional models built in Ansys Mechanical APDL 2022 R1 which uses finite element method. The model is verified by comparing results from an experimental bending test. Both elastic and plastic material properties have been defined. LVL is considered an orthotropic material and aluminium alloy an isotropic material. Results from the analysis show that numerical models can simulate experiments with little deviation. The accuracy of models can be adjusted by changing built-in parameters in Ansys as needed. A thicker LVL beam will contribute to a stiffer hybrid beam, but it also increases the slip from the aluminium beam. It provides a rigid connection with 66 bolts and can be improved by increasing the number of bolts, but reducing more bolts is not recommended. The change in stiffness is not significant when the thickness of the web on the aluminium beam is changed and, on the other hand, results in greater slip. In general, the hybrid beam of LVL and aluminium alloy has high stiffness in relation to its low weight and is corrosion resistant. It can be a good alternative to traditional building materials.

Affected by the inherent ideas like "Focus on Function Realization, Despise Security Protection", there are lots of hidden threats in the industrial control system of wind farms (ICS-WF), such as unreasonable IP configuration, failure in virus detection and killing, which are prone to illegal invasion and attack from the cyberspace. Those unexpected unauthorized accesses are quite harmful for the stable operation of the wind farms and regional power grid. Therefore, by investigating the current security situation and needs of ICS-WF, analyzing the characteristics of ICS-WF’s architecture and internal communication, and integrating the ideas of the classified protection of cybersecurity, this paper proposes a new customized cybersecurity strategy for ICS-WF based on the barrel theory. We also introduce an new anomalous intrusion detection technology for ICS-WF, which is developed based on statistical models of wind farm network characteristics. Finally, combined all these work with the network security offense and defense drill in the industrial control safety simulation laboratory of wind farms, this research formulates a three-dimensional comprehensive protection solution for ICS-WF, which significantly improves the cybersecurity level of ICS-WF.

High-quality ZnCr2O4 (ZCO) thin films were epitaxially grown on economical c-sapphire substrates by pulsed laser deposition (PLD) for the first time, using a ZCO ceramic target and various deposition oxygen pressures. X-ray diffraction results revealed that the as-grown ZCO films consisted of a single spinel phase, and exhibited out-of-plane and in-plane orientations with respect to the c-sapphire substrate of ZCO (1 1 1)||Al2O3 (0 0 0 1) and ZCO [0 1 −1]||Al2O3 [1 −1 0], respectively. Due to domain matching with a tiny misfit of 0.015%, high-quality epitaxy of (1 1 1)-ZCO on c-sapphire was achieved with typical (2 2 2) rocking-curve half width of ∼0.07° and φ-scan half width of ∼1.85°. Moreover, the films exhibited very smooth surface with a minimum root-mean-square roughness of 0.585 nm. As the deposition oxygen pressure was increased, the atomic ratio of Zn/Cr in the ZCO films was found to increase linearly from 0.316 to 0.585, while the bandgap of the ZCO films increased simultaneously from 3.61 eV to 3.87 eV. The widening of bandgap was attributed to the enhancement of cations-anions interaction and reduction of oxygen vacancies with increasing deposition oxygen pressure. Our work provides a feasible and economical solution for the epitaxial growth of high-quality ZCO films, based on which fundamental properties and technological applications of ZCO can be further explored.

Although β-Ga2O3 is considered an excellent candidate for solar-blind photodetectors (PDs) owing to its direct bandgap (4.9 eV) and high stability, the cut-off wavelength often oversteps the DUV region, reducing the rejection ratio of the PD. Moreover, oxygen vacancies, which always appear in β-Ga2O3 films, act as trap centers hindering carrier recombination and significantly lowering response speed. To disentangle these issues, we propose in this work to modify β-Ga2O3 by incorporating Sc to form ternary (ScGa)2O3 alloys. Thanks to the wider bandgap of Sc2O3 (∼5.7 eV) than Ga2O3 and stronger Sc–O bonding than Ga–O, the (ScGa)2O3 alloy films exhibit a wider bandgap (5.17 eV) with fewer oxygen vacancies compared with pure-Ga2O3, as expected, which eventually lead to an ultra-low dark current (0.08 pA at 10 V) and faster response times (τrise: 41/149 ms; τdecay: 22/153 ms) of the alloy film-based PDs. Furthermore, the peak and cut-off response wavelengths of the (ScGa)2O3 PD are blue shifted relative to the pure Ga2O3 PD, resulting in a higher rejection ratio (>500 vs ∼317). The Sc-alloying strategy, taking advantage of wider bandgap of Sc2O3 and stronger Sc–O bonding to widen the bandgap while reducing the intrinsic carriers and oxygen vacancies in the (ScGa)2O3 alloy, is expected to be generally applicable to the design of other wide-bandgap oxide alloys for developing high-performance UV photodetectors with a low dark current and high response speed.

In this work, high-quality SnO2 and Hf0.38Sn0.62O2 thin films were grown on c-plane sapphire substrates by pulsed laser deposition for a comparative study. The optical and electrical tests show that Hf doping leads to significantly increased bandgap and resistivity of the HfSnO2 alloy as compared to SnO2. Then, SnO2- and Hf0.38Sn0.62O2-based UV detectors were fabricated and compared. The Hf0.38Sn0.62O2 film-based detector exhibits an excellent performance. Its dark current is as low as 0.2 pA under 20 V, and the rise/decay response time is as short as 69 ms/50 ms. The cut-off wavelength and the rejection ratio are 290 nm and 4100, respectively. Our work demonstrates that the Hf0.38Sn0.62O2 ternary alloy compound semiconductor has great potential for applications in solar-blind ultraviolet detections.

Heterostructures such as heterojunctions, quantum wells, and superlattices are core components of advanced optoelectronic devices. Herein, we attempted the first investigations on the band alignment of nonpolar m-plane oriented ZnO1−xSx/Mg0.4Zn0.6O heterojunctions by X-ray photoelectron spectroscopy. All the heterojunctions were revealed to show a type-I band alignment, and the valence band offset (VBO; ΔEV) increased significantly, while the conduction band offset (ΔEC) decreased insignificantly with increasing S content in the ZnO1−xSx layer. Specifically, for the ZnO1−xSx/Mg0.4Zn0.6O heterojunctions with x = 0, 0.13, and 0.22, ΔEV (ΔEC) was determined to be 0.24 (0.22), 0.61 (0.17), and 0.79 (0.11) eV, respectively. The VBOs of ZnOS/MgZnO heterojunctions are significantly larger than those of heterojunctions involving only cation-substituted alloys (ZnO/MgZnO or ZnO/CdZnO) due to the opposite shift in the VB maximum of ZnOS and MgZnO with respect to ZnO. Knowing band alignment parameters of the ZnOS/MgZnO interface can provide a better understanding of the carrier transport mechanism and rational design of ZnO-based optoelectronic devices.

With the large-scale development of wind power, the storage and analysis of wind turbine’s data gradually become more and more important, there are huge amount of information about wind turbines, and the traditional relational database has been difficult to meet the demand of mass data storage and analysis. This chapter proposes the solutions that data storage is based on non-relational databases (MongoDB) and compares SQL Server with MongoDB about the storage ability and query performance. The results show that using this method can increase storage speed and query performance significantly.