Ricerc@Sapienza

Static power consumption is one of the most critical issues in CMOS digital circuits, and FinFET technology is being recognized as a valid solution for the problem. In this chapter, we utilize a logic-level leakage current estimation technique relying on an internal node voltage-based model. The model is implemented in the form of VHDL packages. By utilizing the capability of the model, the behavior of major leakage component has been analyzed separately for FinFET technology scaling over single- and multi-stage digital standard cells.

This paper presents the analysis and development of an evanescent waveguide sensor system, based on a hydrogenated amorphous silicon (a-Si:H) photodiode and a double ion-exchanged waveguide diffused in a borosilicate BK7 glass substrate. The a-Si:H sensor is a p-doped/intrinsic/n-doped diode, with a metal top electrode and an indium tin oxide (ITO) transparent bottom contact. Simulations on the confinement of a monochromatic light in a channel waveguide and its coupling into a thin-film photodetector were performed using COMSOL Multiphysics.

Here we present the design of an amorphous silicon photodetector integrated with an ion-exchanged waveguide on the same glass substrate in order to obtain an evanescent waveguide sensor for on-chip biomolecular recognition in Lab-on-Chip applications. We studied the behaviour of a monochromatic light in a channel waveguide and its coupling into the thin-film sensor, using COMSOL Multiphysics. Simulations show that the presence of the photodiode’s insulation layer and transparent electrode strongly affects the coupling efficiency between the waveguide and the sensor.

An enzymatic treatment with cell wall degrading enzymes aimed at improving the recovery of lipids from Chlorella sorokiniana was investigated. Six commercial enzyme preparations containing cellulase, pectinase, lysozyme and three different hemicellulases were preliminary tested. The most effective preparations were then used as basic components for the formulation of enzyme cocktails with high cell wall degrading activity. Experiments were carried out according to the mixture design methodology.

Uncoated and nano iron-based coated biomass were employed as packing material in lab-scale and large-lab-scale columns for the removal of Cr(VI) from synthetic wastewaters. A remarkable Cr(VI) removal efficiency (up to about 65%) was observed in large-lab-scale configuration, thus allowing to treat notable amounts of effluents volumes (30–70 L, basing on the inlet flow-rate) at fixed bed height of 38 cm and a sorbent mass of 850 g and 790 g of uncoated and coated material, respectively.

This article presents an experimental investigation of the effects of temperature and atmosphere on the tensile behaviour of basalt fibres. The heating conditions have been chosen in order to mimic those used in thermal recycling of polymer matrix composites. The change of properties is investigated at room temperature on fibres heat-treated for 1 h up to 600 °C in air and in inert atmosphere (argon).

Due to their capability to recover the initial shape, Shape Memory Alloys (SMAs) are widely used in many applications. Different grades are commercially available and they can be classified considering either their chemical compositions (e.g., Cu based, Ni based, Fe based) or according to their mechanical behaviour. The most used SMAs are the Ni based alloys thanks to their performances both in terms of mechanical resistance and in terms of fatigue resistance, but their costs are quite high. Cu based alloys are good competitors of the Ni based alloys.

NiTi shape memory alloys are well-known due to their outstanding functional properties including superelasticity (SE) and Shape Memory Effect (SME). Laser welding is a viable technique for the joining of NiTi wires, which are employed in the design of smart structures. Joining of dissimilar wires can provide better flexibility using various alloys and, consequently, lead to multi-functional properties.

We investigate numerically the homogenization process of a diffusive species in a mixing channel of arbitrary length downstream a microfluidic cross-junction. The channel length, λα, necessary to achieve a prescribed level of mixedness, α, is targeted as primary quantity of interest, and its dependence on the Reynolds number, Re, on the flow ratio between the impinging currents, R, and on the Schmidt number of the solute, Sc, is analyzed.

A carbon nanotube (CNT)/gold nanoparticle (NP) nanocomposite was synthesized by simultaneously reducing the Au ions and depositing Au NPs on the surface of a CNT. The functional groups were investigated with Fourier transform infrared spectra. From the Raman spectra, the D-band and G-band of the CNT were identified. The deposition of nanometer-sized Au NPs on the CNT sites was observed by transmission electron microscopy.