|
|
Kumaresan, N., Alsalhi, M. S., Karuppasamy, P., Kumar, M. P., Pandian, M. S., Arulraj, A., et al. (2023). Nitrogen implanted carbon nanosheets derived from Acorus calamus as an efficient electrode for the supercapacitor application. Mol. Catal., 538, 112978.
Abstract: Modern society's biggest challenges are affordable, clean energy production and storage. Thus, recent research aims at the discovery of novel electrode materials for enhanced energy production and storage. Herein, nitrogen-implanted carbon particles were synthesized for the first time from the Acorus Calamus for the symmetric supercapacitor application. The KOH-activated carbon particles at 750 degrees C (C-750) under a nitrogen atmosphere revealed the better structural, textural, morphological, and electrochemical performance. The BET analysis confirmed that the C-750 carbon nanoparticles tremendously enhanced the surface area of about 3551.07 m(2)/g. Further, the pore size and pore volume were obtained from BJH analysis that showed 3.70 nm and 0.51 cc/g, respectively. The high surface area along with the mesoporous nature of the C-750 sample effectively enhanced the specific capacitance to 354.44 Fg(-1) at 1 Ag-1 using a 6 M KOH electrolytic solution. Further, the enhancement of energy and power density of the C-750 was observed at about 47.2 Whkg(-1) and 16,000 Wkg(-1), respectively.
|
|
|
|
Navarro, A., Favereau, M., Lorca, A., Olivares, D., & Negrete-Pincetic, M. (2024). Medium-term stochastic hydrothermal scheduling with short-term operational effects for large-scale power and water networks. Appl. Energy, 358, 122554.
Abstract: The high integration of variable renewable sources in electric power systems entails a series of challenges inherent to their intrinsic variability. A critical challenge is to correctly value the water available in reservoirs in hydrothermal systems, considering the flexibility that it provides. In this context, this paper proposes a medium -term multistage stochastic optimization model for the hydrothermal scheduling problem solved with the stochastic dual dynamic programming algorithm. The proposed model includes operational constraints and simplified mathematical expressions of relevant operational effects that allow more informed assessment of the water value by considering, among others, the flexibility necessary for the operation of the system. In addition, the hydrological uncertainty in the model is represented by a vector autoregressive process, which allows capturing spatio-temporal correlations between the different hydro inflows. A calibration method for the simplified mathematical expressions of operational effects is also proposed, which allows a detailed shortterm operational model to be correctly linked to the proposed medium -term linear model. Through extensive experiments for the Chilean power system, the results show that the difference between the expected operating costs of the proposed medium -term model, and the costs obtained through a detailed short-term operational model was only 0.1%, in contrast to the 9.3% difference obtained when a simpler base model is employed. This shows the effectiveness of the proposed approach. Further, this difference is also reflected in the estimation of the water value, which is critical in water shortage situations.
|
|
