The Analysis of Different Factors Affecting the Red Wines Antioxidant Content

The benefits of moderate consumption of wines consist in the protective effects against cardiovascular diseases and anticarcinogenic is associated with their antioxidants content. There are plenty of analytical methods for assessing the antioxidant content of wines but unfortunately, there is not a standardized method. The antioxidant content of ‘Cabernet Sauvignon’, ‘Merlot’ and ‘Pinot Noir’ wines obtained from cultivated grapes varieties from Recas and Minis Romanian vineyard from different harvesting years were investigated. The electron paramagnetic resonance spectroscopy, using the 2,2,6,6-tetramethyl-4-hydroxypiperidine-N-oxyl (Tempol) free stable radical, was used to determine the antioxidant content of wines. Measurements were done in order to analyze the effects of the grape varieties, the harvesting year and the vineyard on the antioxidant content of wines. The obtained results revealed that the antioxidant content of studied red wines depends on the harvesting year of grape, the grape variety and on the vineyard. Using the observed values of the antioxidant content, a relationship was identified between the antioxidant content of wines and the harvesting year of grapes. Furthermore, the designed generalized nonlinear model revealed that the antioxidant content of wine depends on the combined effect of the grape variety and the vineyard, besides the year, the grape variety and the vineyard.

Safety and Comfort Analysis of Optimal Seats With Active and Semi-Active Suspension

A generalized nonlinear model is formulated for dynamic analysis of suspension seats with passive, semi-active and active dampers. The model incorporates coulomb friction due to suspension linkages and bushings, forces arising from interactions with the elastic limit stops, a linear suspension spring and nonlinear damping force on the basis of passive, semi-active and active dampers, while the contribution due to biodynamics of the human operator is considered to be negligible. The semi-active and active dampers are charcterized by force generators in accordance with the control laws based upon suspension mass velocity. Two different suspension seats are experimentally assessed in the laboratory under sinusoidal and random excitations arising from an urban bus, and the measured data is used to demonstrate the validity of the proposed generalized model. The results showed reasonably good agreement between the model results and the measured data. Optimal model parameters are selected using the sequential unconstrained minimization technique with an objective to minimize the acceleration due to vibration transmitted to the occupant mass. The comfort and safety performance characteristics of the optimal suspension seat with semi-active and active dampers are evaluated under both the sinusoidal and random excitations on the basis of the guidelines provided in ISO-2631. From the results it is concluded that the comfort performance of a suspension seat with semi-active and active dampers can be considerably enhanced, in the 20% to 30% range.

A Generalized Nonlinear Model for Active Magnetic Bearings

This paper describes a generalized nonlinear model of active magnetic bearings, for arbitrary number, size and position of pole-pairs, including the coordinate coupling between the vertical and horizontal directions, the nonlinearility of the power amplifier and the effect of finite permeability of the ferromagnetic bearing material. As an example, a practical magnetic bearing with four pole-pairs is examined. The predicted force from the model is quite consistent with experimental results. For the PD controller implemented for a horizontal rotor, the expectation of the equilibrium of the rotor also agrees quite well with the measurement.