Hazards and safety issues associated to the residual solid content in crude edible oil processing

The present work focuses on the hazards connected with edible oil refining during process and maintenance operations. A specific experimental protocol was set up in order to verify the possibility of having fire hazards connected with the unwanted residual solids which might accumulate on the bottom of storage tanks, due to sedimentation, or in process equipment, due to progressive fouling. The analysis of residual solid samples taken from an actual edible oil refinery allowed evaluating the possible formation of flammable mixtures or products during maintenance operations. Specific hazard indexes were defined in order to analyse two case studies which provided indications for the safety enhancement of process and maintenance operations

A source of entangled photons based on a cavity-enhanced and strain-tuned GaAs quantum dot

A quantum-light source that delivers photons with a high brightness and a high degree of entanglement is fundamental for the development of efficient entanglement-based quantum-key distribution systems. Among all possible candidates, epitaxial quantum dots are currently emerging as one of the brightest sources of highly entangled photons. However, the optimization of both brightness and entanglement currently requires different technologies that are difficult to combine in a scalable manner. In this work, we overcome this challenge by developing a novel device consisting of a quantum dot embedded in a circular Bragg resonator, in turn, integrated onto a micromachined piezoelectric actuator. The resonator engineers the light-matter interaction to empower extraction efficiencies up to 0.69(4). Simultaneously, the actuator manipulates strain fields that tune the quantum dot for the generation of entangled photons with fidelities up to 0.96(1). This hybrid technology has the potential to overcome the limitations of the key rates that plague current approaches to entanglement-based quantum key distribution and entanglement-based quantum networks. Introductio

Safety issues related to the maintenance operations in a vegetable oil refinery: A case study

The present work was focused on maintenance hazards related to vegetable oil refining. An incident occurred in an Italian vegetable oil refinery was presented to evidence this safety criticality. The incident took place during a maintenance shut down, and was associated to the ignition of the solid residual in a packed column. No fatalities or injuries were reported, but the column was strongly damaged and removed from the plant. A specific experimental characterization of the solid residues accumulated in the column, sampled both from the damaged and undamaged parts of the column, was carried out in order to determine the conditions leading to unwanted combustion of the residues. At the same time, samples taken from the damaged column steelwork were subjected to metallurgical analysis aimed at the thermal and mechanical characterization of the steel, obtaining information about the incident duration and temperature reached during the combustion phenomenon. The study evidenced the need of adequate maintenance procedures and safety management in the generic framework of food industry, identified as key lessons learned

FDEMtools: a MATLAB package for FDEM data inversion

Electromagnetic induction surveys are among the most popular techniques for non-destructive investigation of soil properties, in order to detect the presence of both ground inhomogeneities and particular substances. This paper introduces a MATLAB package, called FDEMtools, for the inversion of frequency-domain electromagnetic data collected by a ground conductivity meter, which includes a graphical user interface to interactively modify the parameters of the computation and visualize the results. Based on a non-linear forward model used to describe the interaction between an electromagnetic field and the soil, the software reconstructs the distribution of either the electrical conductivity or the magnetic permeability with respect to depth, by a regularized damped Gauss-Newton method. The regularization part of the algorithm is based on a low-rank approximation of the Jacobian of the non-linear model. The package allows the user to experiment with synthetic and experimental data sets, and different regularization strategies, in order to compare them and draw conclusions