An overview of tissue engineering approaches for management of spinal cord injuries

Severe spinal cord injury (SCI) leads to devastating neurological deficits and disabilities, which necessitates spending a great deal of health budget for psychological and healthcare problems of these patients and their relatives. This justifies the cost of research into the new modalities for treatment of spinal cord injuries, even in developing countries. Apart from surgical management and nerve grafting, several other approaches have been adopted for management of this condition including pharmacologic and gene therapy, cell therapy, and use of different cell-free or cell-seeded bioscaffolds. In current paper, the recent developments for therapeutic delivery of stem and non-stem cells to the site of injury, and application of cell-free and cell-seeded natural and synthetic scaffolds have been reviewed

A Market-Based Optimization Approach for Domestic Thermal and Electricity Energy Management System: Formulation and Assessment

The increase of domestic electrical and thermal controllable devices and the emergence of dynamic electrical pricing leads to the opportunity to integrate and optimize electrical and thermal energy at a house level using a home energy management system (HEMS) in order to minimize the energy costs. In the literature, optimization-based algorithms yielding 24-h schedules are used in spite of their growing complexity with the number of controllable devices and their sensitivity to forecast errors which leads, in most of the cases, to suboptimal schedules. To overcome this weakness, this paper introduces a domestic thermal and electrical control based on a market approach. In contrast with the optimization-based HEMS, the proposed market-based approach targets a scalable and reactive optimal control. This paper first formulates the market-based optimization problem with generality and discusses its optimality conditions with regards to the microeconomic theory. Secondly, this paper compares its optimality to an optimization-based approach and a rule-based approach under forecast errors using Monte Carlo simulations. Finally, this paper quantifies and identifies the effectiveness boundaries of the different approaches

An optimality assessment methodology for home energy management system approaches based on uncertainty analysis

The emergence of ICT based devices enables houses and buildings to become an active part of their environment, by shifting their thermal or electrical consumption/production at different time period according to the grid requirements. Considering the rise of interests for time-dependent electricity tariffs, Home Energy Management System (HEMS), a computer-aided tool with communication ability, is a promising tool for helping prosumers to optimize their device operation accordingly to their comfort and the given electricity price. This dissertation first delivers an overview on the different HEMS approaches, their typical objective functions, their formulations and the considered flexible devices in the literature. This literature review highlights the various HEMS forms and the difficulty to compare them because of the specificity of their evaluation conditions. For this purpose, this dissertation presents an assessment methodology which considers the HEMS evaluation conditions, typically time-series, as uncertain parameters. An uncertainty analysis method for uncertain time-series is developed for fast uncertainty analysis according to stochastic optimization theory. It is shown that for a HEMS approach, the results of 10 000 Monte Carlo simulations can be achieved by 3 simulation runs per uncertain parameters with an appropriated selected set of representative scenarios. Finally, this assessment method is used for comparing and quantifying the saving potential of two different HEMS: an optimization and a market-based control, which both are compared to a conventional control, taken as reference case. The specific saving potential associated to each flexible devices is also studied as well as the sensitivity of these results to a forecast error. All the presented results take into account different user profiles for electrical and domestic hot water demand and consider 5 years of historical data for the temperature and the irradiation in Germany

Theoretical and experimental analysis of rare earth whispering gallery mode laser relative intensity noise

International audienceThe relative intensity noise (RIN) of a solid state whispering-gallery-mode class-B laser is studied both theoretically and experimentally under different pumping regimes. In particular, we show that harmonics of the spiking frequency are observed in the RIN spectrum. A rate equation model including Langevin forces and the nonlinear coupling between inverted ion and photon number fluctuations has been developed to reproduce the experimental results and to extract relevant physical parameters from the fitting of the RIN spectrum

Peak shaving: a planning alternative to reduce investment costs in distribution systems?

In the future, the foreseen increase of residential electricity consumption will force the Distribution System Operators to reinforce their networks at great expense. Through the emergence of ICT solutions and the increase of electric consumption flexibility at residential level, peak shaving has become an interesting alternative for reducing the investment costs in a distribution grid facing a load increase. This can be achieved with energy management systems (EMS) installed at residential level. Specifically, this work aims at considering peak shaving as an alternative to network reinforcement in a 20-year distribution planning study. For this purpose, the present work incorporates an optimal peak shaving approach to an accurate Convex DistFlow-based planning approach. Based on this, it quantifies how peak shaving can economically compete with network reinforcements for 12 real UK distribution networks under various flexibility scenarios. The results highlight that peak shaving is a competitive alternative to line reinforcement if the maximum initial line loading at the initial year of the planning study is under 80% of its nominal thermal rating value. It is also shown that EMS devices with a cost between 10 and 250 £/unit are economically competitive with network reinforcements depending on the considered network. Finally, this work proposes a planning decision metric, the initial line loading (ILL), measured at the beginning of the planning study, on the basis of which reinforcement decisions can be made