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The hydraulic turbines are operating in dynamic and stationary regimes, strongly affected by random noises. In order to achieve the automatic control and operation optimization, one needs automatic control systems which are simultaneously performing a series of operations, from the conventional control to the operating optimization. A system structure is suggested, which is going to carry out in a correlated and integrated way the functions of power control, control combining, system identification, state estimation, and dynamic and stationary optimization of turbine efficiency.

Due to the rapid depletion of traditional fossil energy resources the optimal utilization of renewable resources such as the solar energy becomes a leading task in power engineering. In recent years photovoltaic energy-linked technologies has reached major advances in order to achieve improved energy efficiency conversion rates. In this endeavor, a huge amount of high quality research effort is dedicated worldwide. This paper is focused to present the design and implementation steps of a LabView -based toolkit aimed to modeling and simulates solar photovoltaic (PV) cells in a wide range of operation conditions. By using its well known mathematical model, it has been conceived a versatile and user-friendly simulator well suitable to study and evaluate energy efficiency conversion processes. In order to maximize the energy conversion efficiency the maximum power point tracking (MPPT) algorithm has been implemented. The virtual instrument (VI) developed in the graphical programming language allows fast and convenient monitoring of PV cell output magnitudes and plots the I-U and P-U diagrams under different operation conditions. These curves have been compared then with the diagrams provided by the PV module manufacturer. The obtained results are in good agreement with the manufacturer’s catalogue data.

Results of an experimental program on the instability of unstiffened aluminum-alloy conical shells under combinations of 3 loadings, axial compression, torsion and external or internal pressure are presented and compared with linear theory. Improvements in experimental technique permitted many repeated buckling tests on the same metal specimen without noticeable damage and yielded reliable interaction curves. Some tests on Mylar conical shells under similar combined loading, are then discussed. Tests of the mechanical properties of Mylar A sheets revealed considerable anisotropy that casts some doubt on the reliability of results obtained with Mylar specimens. The general instability of stiffened cylindrical shells under combined axial compression and external or internal pressure is then discussed and design implications are considered. The variation of stiffener spacing in stiffened conical shells yields an improvement in structural efficiency. Optimization studies that investigate this improvement for ring stiffened cones in detail are presented. Results of a continuation of an experimental program on the general instability of ring-stiffened conical shells are presented. Tests on integrally machined steel specimens under torsion, axial compression and combined torsion and axial compression are discussed and compared with theory.