Rehydroxylation Dating: Assessment for Archaeological Application

Investigations are carried out into the mass gain behaviour of fired clay ceramics following drying (130°C) and reheating (500°C), and the application of these mass gain properties to the dating of archaeological ceramics using a modified rehydroxylation dating (RHX) methodology, a component based approach. Gravimetric analysis is conducted using a temperature and humidity controlled glove box arrangement (featuring a top-loading balance) on eighteen samples of varied known ages and contexts; this occurs following transfer from environmentally controlled chambers where subsamples of these samples are aged at three temperatures (25°C, 35°C, 45°C) following drying and reheating. The sample set consists principally of post-medieval bricks, but also includes some post-medieval pottery as well as both Etruscan and Roman ceramics. A suite of techniques are applied to characterise these ceramics, including XRD, FTIR, p-XRF, thin-section petrography, BET analysis, TG-MS and permeametry.

Identification of Microturbine Model for Long-term Dynamic Analysis of Distribution Networks

As one of the most successfully commercialized distributed energy resources, the long-term effects of microturbines (MTs) on the distribution network has not been fully investigated due to the complex thermo-fluid-mechanical energy conversion processes. This is further complicated by the fact that the parameter and internal data of MTs are not always available to the electric utility, due to different ownerships and confidentiality concerns. To address this issue, a general modeling approach for MTs is proposed in this paper, which allows for the long-term simulation of the distribution network with multiple MTs. First, the feasibility of deriving a simplified MT model for long-term dynamic analysis of the distribution network is discussed, based on the physical understanding of dynamic processes that occurred within MTs. Then a three-stage identification method is developed in order to obtain a piecewise MT model and predict electro-mechanical system behaviors with saturation. Next, assisted with the electric power flow calculation tool, a fast simulation methodology is proposed to evaluate the long-term impact of multiple MTs on the distribution network. Finally, the model is verified by using Capstone C30 microturbine experiments, and further applied to the dynamic simulation of a modified IEEE 37-node test feeder with promising results.