Silicon nanoparticles as active materials for LED: laser synthesis and functionalization for tuning luminescence

Silicon nanocrystals (SiNPs) are an extensively studied light-emitting material due to their inherent biocompatibility and easy integration with silicon-based technology. Although low luminescence quantum yields of as-prepared SiNPs, the exploitation of the surface chemistry of SiNPs plays a key role in tuning their luminescence. In this work, the development of SiNPs as active materials for innovative LEDs was investigated. SiNPs were synthesized by using laser pyrolysis, a very flexible tool for lab-scale production in developmental quantities. The synthesized SiNPs have dimensions from 5 to 15 nm and high purity grade but show weak luminescence. For this reason, chemical treatments were performed on SiNPs: surface modifications lead to an improvement of their luminescence properties. Chemical and optical characterization were performed by conventional and advanced techniques, such as FTIR, BET, UV-VIS absorption and emission, XPS, TEM and confocal Raman. A Life Cycle Assessment (LCA) study of laser synthesis of SiNPs was conducted with the aim to identify the potential environmental impacts coming from this production method

Seismic performance of precast reinforced concrete buildings with dowel pin connections

A key aspect in determining the seismic performance of industrial Precast Structures (PS) are the connections between precast elements. The main issue is the capacity of beam-column connections to allow relative displacements without losing beam seating, and to transfer lateral horizontal forces from the beam to the column, without losing load carrying capacity. Referring to a case study based on an industrial PS located in Italy, this work critically investigates the influence of different variables on the connection behaviour, as well as the results of the different safety assessment approaches. Attention has been paid to provide a comparison between different (linear and nonlinear, static and dynamic) analyses with both lumped and diffused nonlinear models. The analyses highlight the importance of the connection between members in the seismic upgrade of existing PS, and the minor role of the mechanical slenderness of the column when considering weak connections

Seismic assessment of existing precast concrete buildings: Influence of deformable connections

The paper is focused on the key role of the connections between precast elements in determining the seismic performance of industrial Precast Structures (PS). The work critically investigates the influence of different variables on the connection behaviour, as well as the results of the different safety assessment approaches. Referring to a case study based on an industrial PS located in Italy, one highlights the importance of the connection in the seismic upgrade of existing PS, and the minor role of the mechanical slenderness of the column when considering weak connections

Combining Life Cycle Assessment and qualitative Risk Assessment: the case study of alumina nanofluid production.

In this paper the authors propose a framework for combining life cycle assessment (LCA) and Risk Assessment (RA) to support the sustainability assessment of emerging technologies. This proposal includes four steps of analysis: technological system definition; data collection; risk evaluation and impacts quantification; results interpretation. This scheme has been applied to a case study of nanofluid alumina production in two different pilot lines, \u201csingle-stage\u201d and \u201ctwo-stage\u201d. The study has been developed in the NanoHex project (enhanced nano-fluid heat exchange). Goals of the study were analyzing the hotspots and highlighting possible trade-off between the results of LCA, which identifies the processes having the best environmental performance, and the results of RA, which identifies the scenarios having the highest risk for workers. Indeed, due to lack of data about exposure limits, exposure\u2013dose relationships and toxicity of alumina nanopowders (NPs) and nanofluids (NF), the workplace exposure has been evaluated by means of qualitative risk assessment, using Stoffenmanager Nano. Though having different aims, LCA and RA have a complementary role in the description of impacts of products/substances/technologies. Their combined use can overcome limits of each of them and allows a wider vision of the problems to better support the decision making process

Use of incinerator bottom ash for frit production

This article presents the results of an experimental activityaimed at investigating the technical feasibility and the environmentalperformance of using municipal solid waste incinerationbottom ash to produce glass frit for ceramic glaze (glazefrit). The process includes an industrial pretreatment of bottomash that renders the material suitable for use in glazefrit production and allows recovery of aluminum and iron.The environmental performance of this treatment option isassessed with the life cycle assessment (LCA) methodology.The goal of the LCA study is to assess and compare the environmentalimpacts of two scenarios of end of life of bottomash from municipal solid waste incineration (MSWI): landfilldisposal (conventional scenario) and bottom ash recovery forglaze frit production (innovative scenario). The main results ofthe laboratory tests, industrial simulations, and LCA study arepresented and discussed, and the environmental advantages of recycling versus landfill disposal are highlighted