High efficiency Thermo-Electric power generator

Thermo-Electric (TE) power generation is an attractive method for the direct conversion of thermal energy into electrical one. Both the TE material properties and the power generator architecture play a fundamental role in the achievement of high energy conversion efficiencies. The paper focuses on the TE module architecture design, as well as on the sub-components manufacturing and assembly.     

Viscoelastic Properties of Tarocco Orange Fruit

In this work, the rheometrical behaviour of Tarocco orange fruit was assessed via stress–relaxation testing under constant engineering strain (ε _z) in the range of 5–20% of the initial fruit height, each test being prolonged for 15 min and replicated 20 times. The time course of the experimental dimensionless relaxation modulus (G*) was typical of a viscoelastic solid and was reconstructed by considering two Maxwell elements in parallel to an elastic spring element. In a more restricted ε _z range (i.e. 5–10%), the dimensionless viscoelastic constants (A _i) were found to be approximately constant, the elastic component responsible for the equilibrium residual stress representing about 42% of the initial relaxation modulus. After any orange fruit had been submitted to stress–relaxation testing and decompressed for 5 min, it exhibited a practically negligible mass loss (0.04 ± 0.03%) and a permanent volume contraction rising from 1.7 ± 1.0% to 3.0 ± 0.9% as ε _z was increased from 5% to 10%. Thus, by tasting the orange fruit firmness at ε _z ≤5%, fruit response, being of the viscoelastic type, is expected to give rise to nearly irrelevant deformations.     

Servo-fluid-elastic modeling of contactless levitated adaptive secondary mirrors

The paper develops a comprehensive approach for the servo-fluid-elastic modeling of electromagnetically levitated secondary adaptive mirrors. The system modeling includes the mirror structural dynamics model, its interaction with the fluid film interposed between the mirror and its reference backplate and disturbances due to local air turbulence. The accuracy of the proposed fluid dynamic model is assessed by comparing it with a significant sample of high fidelity 3D Navier?CStokes analyses. The simulation tool is then used to demonstrate the effectiveness and robustness of a recently proposed control, based on a system dynamics cancellation and an iterated steady state feedforward contribution. The simulations clearly highlights the improvements achievable implementing the new control scheme.     

Quantitative optical analysis of filler dispersion degree in MWCNT–epoxy nanocomposite

Recently developed methodology of quantitative analysis based on optical analysis of filler particles’ area distributions is applied now to estimate the dispersion efficiency of multiwall carbon nanotubes in nanocomposite prepared by solution intercalation method. Experimental parameters of dispersing (temperature, duration and power level of ultrasonication) were optimized and the most effective experimental procedure was determined. The methodology of determination of dispersion parameter is proved by indirect method of light transmittance experiments. The nanocomposite specimens having lower dispersion parameter represented the highest transmittance over the nanocomposite specimens.     

Development of a State-Space Water-Level Control for an Array of Cells to be Employed as Compensator in Radiotherapy

This paperdeals with the problem of water-level control for an array ofcells by means of an hydraulic circuit. An on-off valve fillsall the cells, while each cell is drained by a single on-offvalve, so the control is intrinsically coupled. An optimal controlwith PWM (pulse width modulation) valves is carried out. At theend, simulation and experimental results are presented. The arrayof cells may find application as compensator for radiotherapy(Total Body Irradiation), by interposing the cells between thex-ray source and the patient: on-line water-level variationsin the cells allow local radiation dose control.     

A Methodology for RF modeling of packages with external pin measurements

This article presents a methodology that allows the determination of the matrix representation of a package. The methodology is based on a set of calibration measurements, picked up at the external pins of the package, of a set of known integrated circuits. The representation of the package can be used both for a correct measurement of the embedded devices and to improve the design of integrated circuits. The effectiveness of the technique is demonstrated by the de‐embedding of a packaged passive integrated inductor and the design of a low noise amplifier. The measurement sets were obtained through computer simulations. The effects of added noise on data, like measurement errors, are also investigated, and an approximate methodology, able to reduce these effects, is suggested. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:623–634, 2014.     

A prototype whole-life value optimization tool for façade design

Façade design is a cross-disciplinary multi-objective optimization process. The major barrier to devising an optimal façade solution is the evaluation of the true values of alternative façade design options. A simple approach is to focus on a limited number of design criteria that can be evaluated through mono-disciplinary commercial software, while overlooking other cross-disciplinary design criteria. This paper describes a prototype whole-life value optimization tool for façade design, which accounts for the functional, financial, and environmental sustainability of alternative façade options. The tool adopts an integrated approach involving accurate simulation, systematic parametric analysis, and automatic design optimization. The tool is trialled on a real-world façade design project, and it successfully identified optimal façade solutions that outperform the original solutions obtained from the conventional façade design process.