Large thermal biasing of individual gated nanostructures

We demonstrate a novel nanoheating scheme that yields very large and uniform temperature gradients up to about 1K every 100nm, in an architecture which is compatible with the field-effect control of the nanostructure under test. The temperature gradients demonstrated largely exceed those typically obtainable with standard resistive heaters fabricated on top of the oxide layer. The nanoheating platform is demonstrated in the specific case of a short-nanowire device.Comment: 6 pages, 6 figure

FEM Modelling of a 3D Soil-Pile System Under Earthquakes

During earthquakes seismic wave crossing through soft soil can lead to significant curvatures on pile foundations, which in turn lead to significant bending moments. These bending moments are commonly named “kinematic bending moments”, to be distinguished from the “inertial bending moments” due to horizontal forces transferred from superstructures to pile heads. Approaches to carefully evaluate inertial bending moments have been recently developed world-wide; but the evaluation of the kinematic bending moments is still questionable. In this paper a 3D soil-pile FEM system is analysed. The system is subjected to seismic input motions, applied at the base of the system, which represents the conventional bedrock. The FEM analyses lead to the evaluation of the kinematic bending moment distribution along the pile. The pile is embedded in two soil layers, characterised by three different stiffness ratio Vs2/Vs1. Moreover, five different seismic input motions recorded in Europe in the last 30 years are considered

Failure Mode, Effects and Criticality Analysis (FMECA) for Medical Devices: Does Standardization Foster Improvements in the Practice?

Abstract Risk analysis techniques received increasing attention in the health care sector in the last 30 years. These techniques are diffused for health care processes, and less for devices. In fact, risk management for medical devices was introduced only recently (ISO 14971 in 2000 and GHTF/SG3/N15R8 in 2005) [1,2]. The goal of this study is twofold. First, we aim at evaluating the state of the art of the diffusion of standards for the risk assessment of medical devices (with a focus on FMECA). Second, we evaluate the impact of risk assessment techniques on the practice. To pursue the first goal, a literature review has been performed through the investigation of medical and non-medical databases. To reach the second objective, we selected a leading Company in the development of medical devices and we investigated the process enacted to evaluate the risk connected to the design of new devices. The literature search confirmed the widespread application of the FMECA, the scant number of contributions about its applications on medical devices, and the main limitations related to the use of this technique. The empirical investigation showed that the Company spends a surprising amount of time and resources to set and deploy the FMEA rigorously, and it follows the passages envisioned by the literature carefully, with the unique intent to respect the standards. A gap emerges among the practitioners and academic words, with two possible explanations. First, the academics are not addressing the managerial and practical implications of their contributions; in so doing they deepen the "theory versus practice" chasm. Second, the presence of standards actually discourages the practitioners to push over and find new solutions

Direction of arrival estimation using a cluster of beams in a cone-shaped digital array radar'

In this paper some potential system and processing advantages of conformal cone shaped digital array radar have been investigated, in particular in relation to potential alternative approaches for angle estimation with respect to the traditional monopulse. First of all potential benefit in terms of reduction of the number of radiating elements is shown when a conical array is considered with respect to a traditional system formed by four planar arrays, if a coverage of 360° must be assured. Secondly, having in mind an innovative digital array system where the received signals are analog to digital converted at element level and the corresponding data are possibly transferred to a central elaboration unit, an alternative approach is investigated for angular estimation. In this paper we derive the theoretical expression of the Cramer Rao Lower Bound for elevation angle estimation using a cluster of beams; we compare the limit performance of the traditional approach for angle estimation based on Sum and Difference beams with the approach based on a crowded cluster of RX beams properly spaced. The approaches show approximately equivalent performance, making the second particularly interesting for those situations where monopulse is known to experience performance degradation, as low elevation angle estimation; in this particular case an example of cluster design is shown, where the direct signal from a low altitude target must compete with a specular multipath

Particle swarm optimization of GaAs-AlGaAS nanowire photonic crystals as two-dimensional diffraction gratings for light trapping

Semiconductor nanowire ordered arrays represent a class of bi-dimensional photonic crystals that can be engineered to obtain functional metamaterials. Here is proposed a novel approach, based on a particle swarm optimization algorithm, for using such a photonic crystal concept to design a semiconductor nanowire-based two-dimensional diffraction grating able to guarantee an in-plane coupling for light trapping. The method takes into account the experimental constraints associated to the bottom-up growth of nanowire arrays, by processing as input dataset all relevant geometrical and morphological features of the array, and returns as output the optimised set of parameters according to the desired electromagnetic functionality of the metamaterial. A case of study based on an array of tapered GaAs-AlGaAs core-shell nanowire heterostructures is discussed

Failure Mode, Effects and Criticality Analysis (FMECA) for Medical Devices: Does Standardization Foster Improvements in the Practice?

Risk analysis techniques received increasing attention in the health care sector in the last 30 years. These techniques are diffused for health care processes, and less for devices. In fact, risk management for medical devices was introduced only recently (ISO 14971 in 2000 and GHTF/SG3/N15R8 in 2005) [1,2]. The goal of this study is twofold. First, we aim at evaluating the state of the art of the diffusion of standards for the risk assessment of medical devices (with a focus on FMECA). Second, we evaluate the impact of risk assessment techniques on the practice. To pursue the first goal, a literature review has been performed through the investigation of medical and non-medical databases. To reach the second objective, we selected a leading Company in the development of medical devices and we investigated the process enacted to evaluate the risk connected to the design of new devices. The literature search confirmed the widespread application of the FMECA, the scant number of contributions about its applications on medical devices, and the main limitations related to the use of this technique. The empirical investigation showed that the Company spends a surprising amount of time and resources to set and deploy the FMEA rigorously, and it follows the passages envisioned by the literature carefully, with the unique intent to respect the standards. A gap emerges among the practitioners and academic words, with two possible explanations. First, the academics are not addressing the managerial and practical implications of their contributions; in so doing they deepen the “theory versus practice” chasm. Second, the presence of standards actually discourages the practitioners to push over and find new solutions

Tactical Urbanism in Italy: From Grassroots to Institutional Tool—Assessing Value of Public Space Experiments

none3The paper aims to evaluate the value that the experimentation of tactical urban planning activities can assume for the city, through the critical account of some practices in three Italian cities of large (Milan), medium-large (Bari), and medium size (Taranto), which in recent years, in some cases unknowingly, have experienced its effects, also forced by the thrust offered by the need to respond to the consequences of the pandemic. The authors reflect on how short-term interventions started by tactical urbanism movement are inspiring planning institutions to implement short-term place-making initiatives. The contribution moves within the context of new generation urban regeneration in which the transformation of existing spaces is a process of community reconstruction through the redevelopment of public spaces increasingly open to multiple and temporary uses. First through a process of rereading the state of the art of the project of public spaces in Italy and its transformation caused by the pandemic, then through a comparative look between the three case studies, conclusions are drawn on the urban value of the experiments conducted and, on their ability, to identify a new reference point for the sustainable urban regeneration of public spaces.openCariello Alessandro, Ferorelli Rossella, Rotondo, FrancescoCariello, Alessandro; Ferorelli, Rossella; Rotondo, Francesc

Facts, Challenges, Difficulties and Hopes in Single-Cell Biology: Physiopathological Studies

Single-cell approaches are being increasingly used to unravel the many diverse mechanisms underlying biological processes that characterize each cell irrespective of the influx of other cells even within the same tissue. Consequently, the interference of metabolites and nervous stimuli emanating from the circulatory or nervous system in a higher organism like man is avoided. However, while the single-cell approach yields a wealth of data about single-cell metabolism and internal regulatory mechanisms, information about interactions and interrelations among similar or dissimilar cells may remain obscure. Starting from these considerations, here we summarize, without attempting to be exhaustive, some areas in which we think single-cell biological studies could be effective in translational medicine and in other areas of applied sciences. In this short review we describe the facts, challenges and perspectives related to these issues

(E)-3-Heteroarylidenechroman-4-ones as potent and selective monoamine oxidase-B inhibitors

A series of (E)-3-heteroarylidenechroman-4-ones (1a-r) was designed, synthesized and investigated in vitro for their ability to inhibit the enzymatic activity of both human monoamine oxidase (hMAO) isoforms, hMAO-A and hMAO-B. All the compounds were found to be selective hMAO-B inhibitors showing IC50 values in the nanomolar or micromolar range. (E)-5,7-Dichloro-3-{[(2-(dimethylamino) pyrimidin-5-yl]methylene}chroman-4-one (1c) was the most interesting compound identified in this study, endowed with higher hMAO-B potency (IC50 ¼ 10.58 nM) and selectivity (SI > 9452) with respect to the reference selective inhibitor selegiline (IC50 ¼ 19.60 nM, IC50 > 3431). Molecular modelling studies were performed for rationalizing at molecular level the target selective inhibition of our compounds, revealing a remarkable contribution of hydrogen bond network and water solvent

Rheological behavior and morphology of poly(lactic acid)/low‐density polyethylene blends based on virgin and recycled polymers: Compatibilization with natural surfactants

Blends based on poly(lactic acid) and low-density polyethylene were compatibilized exploiting an innovative strategy involving the introduction of different mixtures of two sustainable liquid surfactants characterized by dissimilar hydrophilic–lipophilic ratios. The compatibilization method was first applied on blends made of virgin polymers, aiming at assessing the surfactant mixture inducing a more significant morphology refinement. Besides, to verify the effectiveness of the selected compatibilizers on recycled materials, the same process was carried out on blends based on reprocessed polymers. Interestingly, the compatibilization caused a significant microstructure modification, with a decrease of 54% of the mean size of the dispersed particles, in the case of virgin polymers-based blends, with a consequent increase of 19% of the dynamic elastic modulus. On the other hand, in the case of reprocessed polymers-based blends, a different compatibilizer efficiency was observed, as the noncompatibilized blend showed amore regular microstructure compared to the compatibilized counterpart