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Solanum procumbens L. (Solanaceae) were extracted respectively with n-hexane, ethyl acetate, and methanol to obtain the corresponding extracts. The methanol-soluble extract was acidified by adding HCl 0.5M; this was followed by liquid-liquid partition with CHCl3 to afford CHCl3-soluble fraction. From this fraction, four compounds were isolated and identified as ergosterol peroxide (1), 9,11-dehydroergosterol peroxide (2), N-(N-benzoyl-L-phenylalanyl)-L-phenylalanol (3), and moupinamide (4). Their structures were elucidated based on the NMR spectroscopic analysis and comparison with the literature. All isolated compounds were first reported from S. procumbens.

Voltage source inverters (VSIs) with an LCL-filter are commonly used in practice, especially in microgrid systems. Exactly determining the control coefficients for the controller of a VSI with an LCL-filter is an important and challenging issue. However, existing LCL-filter-based inverter systems usually assume that all system parameters are determined accurately and remain constant over time, which is not true in real situations. Variations in the system parameters are known to possibly seriously degrade the performance of LCL-filter-based inverter systems. For efficiency and robustness, this paper proposes a simple and robust method for the generalized controller design of a three-phase VSI with an LCL-filter system that can address deviations in system parameters. The proposed method can be effectively used to design the controller of an LCL-filter inverter system for fixed and varying system parameters. Simulations and experimental results are presented to validate the correctness and effectiveness of the proposed design method.

Harmonic suppression is an important and challenging issue in electrical power systems and can be resolved by using hybrid active power filters with injection circuit (IHAPFs). In existing IHAPF systems, however, it is usually assumed that all parameters are determined accurately and unchanged over time, which is not true in real situations. It is well known that variations of system parameters may seriously degrade the performance of IHAPF systems. To obtain both efficiency and robustness, this study proposes a novel method for the generalised controller design of a three-phase IHAPF system which can deal with deviations of system parameters. An optimum way to determine the stability bounds under various system parameters cases is introduced. The assessment of the stability bounds is based on the Routh criterion through solving the characteristic equation of the closed-loop control system. Simulations and experimental results are presented to validate the correctness and effectiveness of the proposed design method for controller used in IHAPF system.

The development of distributed generations (DGs) is essential to help solve energy crises and improve the reliability of electricity supplies. However, the involvement of a DG in a grid along with an increase of the nonlinear load will reduce the power quality. To solve this problem, we want the converter used in the DG to work flexibly, intelligently, and more accurately. To contribute to the improvement of quality of the DG, this paper proposes a multifunction converter (MFC) model. With the proposed model, the photovoltaic generator, which can be operated at harmonic suppression, and the power injection are more flexible than in the conventional controller used in DG. The controller of the MFC, which is designed based on the Lyapunov function, always ensures the stability of the system. Simulations and experimental results are presented to validate the correctness and effectiveness of the proposed model.

In this paper, a general design method for multifunction converters using photovoltaic systems is proposed. With the proposed converter, the photovoltaic generator can provide flexibility, accuracy, and fast responses in both harmonic suppression and power injection modes in all cases of the grid-connected load. The controller for the proposed converter is designed based on the Lyapunov technique, along with the generalized algorithm for determining the global optimal values of the stability bounds. Therefore, the proposed converter can perform accurately and efficiently in the case of fixed system parameters as well as in the case of varying system parameters. Simulations and experimental results are presented to validate the accuracy and effectiveness of the proposed model and control strategy.

Fuzzy vault is one of the most popular algorithms, which is used to protect the biometric templates and secret key simultaneously. In the fuzzy vault scheme, the biometric features are used to lock and unlock the secret key, which is encoded in the coefficients of a polynomial equation. Its security depends on the infeasibility of the polynomial reconstruction problem. Additionally, the vault performance can be enhanced by adding more noise (chaff) points to the vault. For a real-time implementation of the bio-cryptosystem, as would be required in today's information security system, existing methods for chaff generation is inadequate. This paper proposed and employed a new fast chaff point generation algorithm which is less time-consuming for producing more points to improve the performance and security of fingerprint fuzzy vault scheme. Our experimental results show that the proposed algorithm achieves faster than existing algorithms and still satisfies the typical security need.