Magnetorheological (MR) fluids are capable of manifesting a rheological behaviour change by means of a magnetic field application and can be employed in many complex systems in many technical fields. One successful example is their use in the development of dampers: magnetorheological dampers (MRDs) are widespread in vibration control systems, as well as civil engineering applications (i.e., earthquake or seismic protection), impact absorption and vibration isolation technology in industrial engineering, and advanced prosthetics in biomedical fields. In the past, many studies have been conducted on MRDs modeling and characterization, but they have usually been focused more on the theoretical models than on the experimental issues. In this work, an overview of both of them is proposed. In particular, after an introduction to the physics of the magnetorheological effect, a short review of the main mathematical models of MRDs is proposed. Finally, in the second part of this study an overview of the main issues that occur in MRDs experimental characterization is reported and discussed.

GM3-ganglioside is known to be involved in melanoma proliferation. In order to modulate metastatic-related events, we have functionalized multi-walled carbon nanotubes (MWCNTs) with multiple copies of a GM3-lactone mimetic. The MWCNTs proved to guarantee the appropriate spatial arrangement of the mimetic allowing a stronger inhibition of migration and invasiveness of human melanoma (A375) cells compared to other multivalent constructs reported before. In addition, the effect of the multivalent tubular conjugate on the inhibition of specific tyrosine kinases, which are associated with the ganglioside complexes within the membrane domains, was demonstrated. Finally, the short-term fate of the conjugate was assessed, for the first time, by means of the ¹H NMR relaxometry technique by exploiting the signal arising from the CNTs.

Whole-body vibration (WBV) is receiving increasing interest as an exercise intervention in physiology and rehabilitation. Although there are many commercial and professional WBV platforms to provide controlled vibrations, very few have actually been tested in terms of amplitude (mm), frequency spectra (Hz) and shape of the vibratory motion wave. In this regard a prototype of a novel WBV platform where the vibration amplitude can be set to three values in the frequency range 20-60 Hz is here proposed. The device has been preliminarily characterized by processing the measurement signal from a piezoelectric monoaxial accelerometer mounted in the center of the WBV plate. In particular the accelerometer signal has been processed to evaluate frequency spectrum, waveform shape and displacement. Moreover to evaluate the performance of the prototype, same tests were carried out on an equivalent professional WBV platform, so that data coming from the two platforms have been compared and commented: test results have shown that the vibrations produced by the two WBV plates are very similar, nevertheless it has been found that the prototype works with a maximum error of about 5 % in frequency, that is less than in the other devices, furthermore the greater distortion of the signal is always at the twice of the operating frequency (second harmonic). Further investigations are needed to complete the characterization of the prototype and assess the vibration amplitude is not load dependent.

In this article we present a study about using VNA calibrated or uncalibrated measurements for the purpose of measuring the Q–factor of a dielectric loaded microwave resonator. We evaluate the uncertainties in Q involved in both methods. We use a complete and robust transmission resonant model for the fit and parameter extraction. The Q values obtained from uncalibrated and calibrated data were compared by taking into account the S-parameter measurement uncertainty.

The number of studies on microgrippers has increased consistently in the past decade, among them the numeric simulations and material characterization are quite common, while the metrological issues related to their performance testing are not well investigated yet. To add some contribution in this field, an image analysis-based method for microgrippers displacement measurement and testing is proposed here: images of a microgripper prototype supplied with different voltages are acquired by an optical system (i.e., a 3D optical profilometer) and processed through in-house software. With the aim to assess the quality of the results a systematic approach is proposed for determining and quantifying the main error sources and applied to the uncertainty estimation in angular displacement measurements of the microgripper comb-drives. A preliminary uncertainty evaluation of the in-house software is provided by a Monte Carlo Simulation and its contribution added to that of the other error sources, giving an estimation of the relative uncertainty up to 3.6% at 95% confidence level for voltages from 10 V to 28 V. Moreover, the measurements on the prototype device highlighted a stable behavior in the voltage range from 0 V to 28 V with a maximum rotation of 1.3° at 28 V, which is lower than in previous studies, likely due to differences in system configuration, model, and material. Anyway, the proposed approach is suitable also for different optical systems (i.e., trinocular microscopes).