Three Cases of Long-Lasting Tumor Control with Erlotinib after Progression with Gefitinib in Advanced Non-Small Cell Lung Cancer

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Heat treatment procedure of the Aluminium 6061-T651 for the Ariel Telescope mirrors

The Atmospheric Remote-Sensing Infrared Exoplanet Large Survey (Ariel) is the M4 mission adopted by ESA’s ”Cosmic Vision” program. Its launch is scheduled for 2029. The purpose of the mission is the study of exoplanetary atmospheres on a target of ∼ 1000 exoplanets. Ariel scientific payload consists of an off-axis, unobscured Cassegrain telescope. The light is directed towards a set of photometers and spectrometers with wavebands between 0.5 and 7.8 µm and operating at cryogenic temperatures. The Ariel Space Telescope consists of a primary parabolic mirror with an elliptical aperture of 1.1· 0.7 m, followed by a hyperbolic secondary, a parabolic collimating tertiary and a flat-folding mirror directing the output beam parallel to the optical bench; all in bare aluminium. The choice of bare aluminium for the realization of the mirrors is dictated by several factors: maximizing the heat exchange, reducing the costs of materials and technological advancement. To date, an aluminium mirror the size of Ariel’s primary has never been made. The greatest challenge is finding a heat treatment procedure that stabilizes the aluminium, particularly the Al6061T651 Laminated alloy. This paper describes the study and testing of the heat treatment procedure developed on aluminium samples of different sizes (from 50mm to 150mm diameter), on 0.7m diameter mirror, and discusses future steps

FEA testing the pre-flight Ariel primary mirror

Ariel (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is an ESA M class mission aimed at the study of exoplanets. The satellite will orbit in the lagrangian point L2 and will survey a sample of 1000 exoplanets simultaneously in visible and infrared wavelengths. The challenging scientific goal of Ariel implies unprecedented engineering efforts to satisfy the severe requirements coming from the science in terms of accuracy. The most important specification – an all-Aluminum telescope – requires very accurate design of the primary mirror (M1), a novel, off-set paraboloid honeycomb mirror with ribs, edge, and reflective surface. To validate such a mirror, some tests were carried out on a prototype – namely Pathfinder Telescope Mirror (PTM) – built specifically for this purpose. These tests, carried out at the Centre Spatial de Liège in Belgium – revealed an unexpected deformation of the reflecting surface exceeding a peek-to-valley of 1µm. Consequently, the test had to be re-run, to identify systematic errors and correct the setting for future tests on the final prototype M1. To avoid the very expensive procedure of developing a new prototype and testing it both at room and cryogenic temperatures, it was decided to carry out some numerical simulations. These analyses allowed first to recognize and understand the reasoning behind the faults occurred during the testing phase, and later to apply the obtained knowledge to a new M1 design to set a defined guideline for future testing campaigns

SPICE Modeling of Li Ion Pouch Battery Cell Including Thermo Electrochemical Effects

The development of efficient, cheap, compact, and reliable storage systems is getting increasingly crucial. Special attention must be given to Li Ion batteries, which stand out for the stability of their open circuit voltage (VOC), current capability, and compactness [1]. Such features make them suitable for a large scale of applications. Unfortunately, the design of electric/electronic systems embedding batteries as power supply/storage is still challenging because of the lack of simple and trustworthy circuital models accounting for complex thermo electrochemical mechanisms. In this abstract, a SPICE compatible compact electrical model of batteries including thermal and chemical effects (hereinafter referred to as macrocircuit) is proposed (Fig. 1). The macrocircuit was customized on a Li ion pouch cell battery in the NMC technology (schematically depicted in Fig. 2), its capacity being C=20 Ah; however, the model can be adapted to a generic product. First, in both the charge and discharge phases, self heating effects are considered along with their impact on the overall electrical behavior of the system. Furthermore, for each simulation, the initial conditions of the state of charge (SoC) of the battery can be defined; the SoC can be then monitored during the simulation run. The macrocircuit is composed by: (i) a core including a voltage generator VOC and a passive network, the values of which are allowed to vary with both the SoC and the cell average temperature (Tavg); (ii) a thermal feedback block (TFB) based on Foster I equivalent network, which provides Tavg as an output; (iii) some behavioral modeling blocks devoted to evaluate the SoC and the dissipated power (PD). It must be remarked that PD is given by the algebraic sum of two components, namely, the irreversible (PD,irr) and the reversible (PD,rev) one. While the former is always positive being it given by the Joule heating dissipation over the core, the latter accounts for the endothermic/exothermic chemical reactions dictated by the entropic coefficient dU/dT occurring in the battery; therefore, PD,rev can also be negative, thus reducing the overall PD and providing cooling effects. The modeling of the above quantities was based on the meticulous experimental campaign conducted in [2]. In order to prove the accuracy of the macrocircuit, simulative results obtained in the OrCAD SPICE software package [3] were compared with the counterpart performed in the FEM environment, which was used as a reference. The 3 D structure and the corresponding multiphysics FEM problem was (i) calibrated by means of the experimental data shown in [4], and simulations were run in COMSOL [5]. Given the initial state of charge SoC0=80% and Tamb=25°C, the discharge of the battery was emulated by defining an outgoing current at 4.5 C (i.e., 90 A). A good agreement between results carried out through the macrocircuit and FEM simulations was achieved in terms of dissipated power (Fig. 3), cell average temperature (Fig. 4), and voltage at the battery terminals (Fig. 5). It must be remarked that each FEM simulation required approximately 10 minutes, while a few seconds were needed by making use of the proposed model. As a further advantage, the model is prone to be adopted in complex SPICE simulations of circuits for applications in power electronics (such as DC/DC converters, inverters, and rectifiers) as well as to study the electrical connection of several pouch cells forming a battery pack

Thermo-Electrochemical FEM and Circuit Simulations of Li-Ion Batteries

In this article, strategies to model thermo-electrochemical mechanisms occurring in Li-ion batteries are introduced. Two models are presented. The first consists in a numerical model suitable for finite-element method (FEM) simulations. The numerical model was validated by comparing simulation results with experimental data. The second model concerns fast and accurate simulations in a SPICE-compatible software package; such a model is denoted by macrocircuit and accounts for the main thermo-electrochemical effects of batteries. The macrocircuit was (i) validated with FEM simulation results and (ii) proven to be effective in simulations of practical circuits based on batteries. Although both the above modeling strategies were applied to a commercial product, they are suitable for batteries in any technology