Towards Additive Manufactured Off-Earth Habitats with Functionally Graded Multi-Materials

This study investigated the feasibility of in-situ manufacturing of a functionally graded metallic-regolith multimaterial. To fabricate the gradient, digital light processing, an additive manufacturing technique, and spark plasma sintering were selected due to their compatibility with metallic-ceramic processing in a space environment. The...

A Tractable Failure Probability Prediction Model for Predictive Maintenance Scheduling of Large-Scale Modular-Multilevel-Converters

Predictive maintenance scheduling of modular-multilevel-converters (MMCs) requires estimations of the failure probabilities of MMCs during a period of time in the future. Particularly, the predicted future failure probabilities are influenced by two main factors, the mission profiles of the MMCs and the maintenance decisions on the MMCs...

A bidding mechanism for maintenance of generation units considering inter-ISO power exchange

To ensure the reliability of power systems, the independent system operator (ISO) manages the planning process of the maintenance of generation units for generation companies (GENCOs). This paper focuses on a widely studied two-layer long-term predictive maintenance decision making framework in a deregulated environment. In the first layer...

Failure prevention and restoration in power systems

In typical power system operations, failures, e.g., caused by degradation, may result in service interruption and loss of power supply. Furthermore, low-occurrence-probability but high-impact extreme events, e.g., natural disasters and cyber-attacks, may also damage the power grid. This thesis aims to develop innovative strategies for handling...

Real-time UAV routing strategy for monitoring and inspection for post-disaster restoration of distribution networks

Natural disasters pose a tremendous risk to the reliability of distribution networks. In this paper, a novel real-time UAV routing strategy for coordination between monitoring and inspection for post-disaster restoration in distribution networks is proposed. With our proposed real-time UAV routing strategy, damages can be inspected by UAVs...

Accelerated optimal maintenance scheduling for generation units on a truthful platform

Maintenance of generation units is a measure to ensure the reliability of power systems. In this paper, a novel blockchain-based truthful condition-based maintenance of generation units (T-CBMGU) platform is proposed to innovate and upgrade state-of-the-art CBMGU. In addition, two valid inequalities are proposed to accelerate the convergence...

On the powder metallurgy, additive manufacturing and welding of oxide dispersion strengthened Eurofer steel

Oxide dispersion strengthened (ODS) steels are promising candidates for use as structural materials in the next generation fission and fusion reactors. Compared to conventional ferritic or martensitic steels, ODS steels exhibit improved high-temperature creep properties and irradiation resistance. Favourable properties are mainly attributed to...

Influence of Measurement Uncertainty on Parameter Estimation and Fault Location for Transmission Lines

Fault location algorithms for transmission lines use the parameters of the transmission line to locate faults after the faults have occurred along the line. Although these parameters can be estimated by the phasor measurement units (PMUs) at the terminal(s) of the transmission line continuously, the uncertainty in the measurements will give...

Additive Manufacturing and Spark Plasma Sintering of Lunar Regolith for Functionally Graded Materials

This study investigates the feasibility of in-situ manufacturing of a functionally graded metallic-regolith. To fabricate the gradient, digital light processing, an additive manufacturing technique, and spark plasma sintering were selected due to their compatibility with metallic-ceramic processing in a space environment. The chosen methods...

A short-term preventive maintenance scheduling method for distribution networks with distributed generators and batteries

Preventive maintenance is applied in distribution networks to prevent failures by performing maintenance actions on components that are at risk. Distributed generators (DGs) and batteries can be used to support power to nearby loads when they are isolated due to maintenance. In this paper, a novel short-term preventive maintenance method is...

Characterisation of the influence of vanadium and tantalum on yttrium-based nano-oxides in ODS Eurofer steel

Oxide dispersion strengthened (ODS) steels are leading candidates for structural materials in nuclear fission and fusion power plants. Understanding the nature of nano-oxide particles in ODS steels is vital for a better control of the microstructure and mechanical properties to further their applications. In this study, electron microscopy...

Microstructure Study of Pulsed Laser Beam Welded Oxide Dispersion-Strengthened (ODS) Eurofer Steel

Oxide dispersion-strengthened (ODS) Eurofer steel was laser welded using a short pulse duration and a designed pattern to minimise local heat accumulation. With a laser power of 2500 W and a duration of more than 3 ms, a full penetration can be obtained in a 1 mm thick plate. Material loss was observed in the fusion zone due to metal...

Applicability study of pulsed laser beam welding on ferritic–martensitic ODS eurofer steel

Pulsed laser beam welding was used successfully to join the oxide dispersion-strengthened (ODS) Eurofer steel. The joining was conducted with a laser power of 2500 W and a pulsed duration of 4 ms. With the filler material being used, a minor material loss and microvoids were observed in the joint. The microstructure of the fusion zone...

Microstructure characterisation and mechanical properties of ODS Eurofer steel subject to designed heat treatments

The present work deals with oxide dispersion strengthened (ODS) Eurofer steel fabricated by powder metallurgy involving mechanical alloying and spark plasma sintering. A heat treatment route including normalising and tempering was applied to the as-produced steel, based on differential scanning calorimetry (DSC) measurement. The...

Solid State Diffusion Bonding of ODS Eurofer Steel by Spark Plasma Sintering

Oxide dispersion strengthened (ODS) steels are considered to be one of the candidate structural materials for advanced nuclear applications due to their high elevated-temperature strength, corrosion resistance, and radiation tolerance. Joining of ODS steels by traditional fusion joining techniques is not applicable, because the melting...

Heritability estimates for 361 blood metabolites across 40 genome-wide association studies

Metabolomics examines the small molecules involved in cellular metabolism. Approximately 50% of total phenotypic differences in metabolite levels is due to genetic variance, but heritability estimates differ across metabolite classes. We perform a review of all genome-wide association and (exome-) sequencing studies published between November...

Effect of mechanical alloying and spark plasma sintering on the microstructure and mechanical properties of ODS Eurofer

Oxide dispersion strengthened (ODS)Eurofer steel was prepared via mechanical alloying (MA)and spark plasma sintering (SPS). Different combinations of MA and SPS parameters were adopted in order to optimise the fabrication process. The experimental results show that the sample milled for 30 h, sintered at 1373 K at a pressure of 60 MPa has...