Polytechnic University of Milan

About: Polytechnic University of Milan is a education organization based out in Milan, Italy. It is known for research contribution in the topics: Finite element method & Population. The organization has 18231 authors who have published 58416 publications receiving 1229711 citations. The organization is also known as: PoliMi & L-NESS.

Absolute-phase phenomena in photoionization with few-cycle laser pulses

Abstract: Currently, the shortest laser pulses1 that can be generated in the visible spectrum consist of fewer than two optical cycles (measured at the full-width at half-maximum of the pulse's envelope). The time variation of the electric field in such a pulse depends on the phase of the carrier frequency with respect to the envelope—the absolute phase. Because intense laser–matter interactions generally depend on the electric field of the pulse, the absolute phase is important for a number of nonlinear processes2,3,4,5,6,7,8. But clear evidence of absolute-phase effects has yet to be detected experimentally, largely because of the difficulty of stabilizing the absolute phase in powerful laser pulses. Here we use a technique that does not require phase stabilization to demonstrate experimentally the influence of the absolute phase of a short laser pulse on the emission of photoelectrons. Atoms are ionized by a short laser pulse, and the photoelectrons are recorded with two opposing detectors in a plane perpendicular to the laser beam. We detect an anticorrelation in the shot-to-shot analysis of the electron yield.

Recycling of WEEEs: An economic assessment of present and future e-waste streams

Abstract: Waste from Electric and Electronic Equipments (WEEEs) is currently considered to be one of the fastest growing waste streams in the world, with an estimated growth rate going from 3% up to 5% per year. The recycling of Electric or electronic waste (E-waste) products could allow the diminishing use of virgin resources in manufacturing and, consequently, it could contribute in reducing the environmental pollution. Given that EU is trying, since the last two decades, to develop a circular economy based on the exploitation of resources recovered by wastes, a comprehensive framework supporting the decision-making process of multi-WEEE recycling centres will be analysed in this paper. An economic assessment will define the potential revenues coming from the recovery of 14 e-products (e.g. LCD notebooks, LED notebooks, CRT TVs, LCD TVs, LED TVs, CRT monitors, LCD monitors, LED monitors, cell phones, smart phones, PV panels, HDDs, SSDs and tablets) on the base of current and future disposed volumes in Europe. Moreover, a sensitivity analysis will be used to test the impact of some critical variables (e.g. price of recovered materials, input materials composition, degree of purity obtained by the recycling process, volumes generated, and percentage of collected waste) on specific economic indexes. A discussion of the economic assessment results shows the main challenges in the recycling sector and streamlines some concrete solutions.

The flow deviation method: An approach to store-and-forward communication network design

Abstract: mo problems reZevant to the design of a store-and-forward communication network (the message routing problem and the channeZ capacity assignment problem) are formulated and are recognized to be essentiaZ Zy non- Zinear, uncoMnA;tcained muZticomodity (m. c. 1 fZm problems. A "FZm Deviation" (FD) method for the soZution of these non-linear, unconstrained m.c. fZm probZems is described which is quite simiZar to the gradient method for functions of continuous variables; here the concept of gradient is repZaced by the concept of "shortest route" flow. As in the gradient method, the application of successive flow deviations leads to ZocaZ minima. of the FD method to the design of the ARPA Computer Network are discussed. FinaZ ly, two interesting applications