THERMODYNAMIC ORC CYCLE DESIGN OPTIMIZATION FOR MEDIUM-LOW TEMPERATURE ENERGY SOURCES

In the large spectrum of organic fluids suitable for Rankine cycles, a fluid that is already wellknown and available on industrial scale but currently excluded from this kind of application has been selected. This choice is due to the remarkable characteristics of the fluid, such as its high molecular weight, good thermal stability, non-flammability, and atoxicity. Compared to those fluids nowadays common in the ORC market, its thermodynamic properties and fluid dynamic behavior lead to a peculiar configuration of the cycle: • Supercritical cycle, when heat input is at medium-high temperature; • Massive regeneration, to obtain higher efficiency; • Low specific work of the turbine; • Relatively high volumetric expansion ratio and relatively low absolute inlet volumetric flow; Accordingly, an innovative cycle design has been developed, including a once-through Hairpin primary heat exchanger and a multi-stage radial outflow expander. This last innovative component has been designed to get the best performance with the chosen fluid: • The high inlet/outlet volumetric flow ratio is well combined with the change in cross section across the radius; • Compared to an axial turbine, the lower inlet volumetric flow is compensated by higher blades at the first stage. It is feasible thanks to the change in section available along the radius, so that there is no need for partial admission; • The prismatic blade leads to constant velocity diagrams across the blade span; • It minimizes tip leakages and disk friction losses, due to the single disk / multi-stage configuration; • The intrinsical limit of a radial outflow expander to develop high enthalpy drop is not relevant for this cycle, presenting itself a very low enthalpy drop. Moreover the tip speed is limited by the low speed of sound and consequently this kind of expander suits well with this cycle arrangement. The results of this study, conducted through thermodynamic simulations, CFD, stress analysis and economic optimization show an ORC system that reaches high efficiencies, comparable to those typical of existing system

Ignitor: Physics and Progress Towards Ignition

Thermonuclear ignition condition for deuterium-tritium plasmas can be achieved in compact, high magnetic field devices such as Ignitor. The main scientific goals, the underlying physics basis, and the most relevant engineering solutions of this experiment are described. Burning plasma conditions can be reached either with ohmic heating only or with small amount of auxiliary power in the form of ICRH waves, and this condition can be sustained for a time considerably longer than all the relevant plasma time scales. In the reference operating scenario, no transport barriers are present, and the resulting thermal loads on the plasma facing component are estimated to be rather modest, thanks to the high edge density and low edge temperature that ensure an effective intrinsic radiating mantle in elongated limiter configurations. Enhanced confinement regimes can also be obtained in configurations with double X-points near the first wall

Lessons from the European Spaghetti Bowl

European economic integration fascinates and inspires for the way it brought peace to a continent torn by violent and long-standing rivalries. The lessons from Europe, however, cannot be applied directly as the degree of the European Union's supranationality is unthinkable elsewhere. This paper discusses how Europe overcame the specific problem of overlapping free trade agreements (FTAs) with the Pan-European Cumulation System which instituted common rules of origin, regional cumulation of value, and completed the full matrix of bilateral FTAs. After this, Europe had what can be thought of as a "customs union" for rules of origin

A new indirect measurement method of the electron temperature for the Protosphera's pinch plasma

This article presents a new method for estimating the electron temperature of the Protosphera's screw pinch. The temperature radial profile is obtained by a self-consistent modeling of a 1D MHD equilibrium along with a 0D power balance of the plasma column, given measurements and estimates of the axial pinch plasma current, of the plasma rotational frequency and, at the equatorial plane, of the electron density radial profile, of the edge poloidal magnetic field, of the edge electron temperature and of the neutrals pressure in the vacuum vessel. The plasma is considered in equilibrium with its neutral phase and in constant rotation. A MATLAB code has been developed with the aim of estimating the MHD radial equilibrium profiles, the thermodynamic plasma state and the neutrals profile. The numerical estimates are compared with available experimental data showing a good agreement.Comment: 4 pages, 6 figures, 1 table, research presented to the "6th ICFDT

Variation of the divertor geometry in Alcator C-Mod

To be published in the Proceedings of the 1 6th IAEA Fusion Energy Conference

Brazilian Thoracic Association recommendations for the management of post-tuberculosis lung disease

Historically, all efforts against tuberculosis were focused on rapid diagnosis and effective treatment to break the chain of transmission of Mycobacterium tuberculosis. However, in the last few years, more and more evidence has been found on the dramatic consequences of the condition defined as post-tuberculosis lung disease (PTLD). Approximately one third of patients surviving pulmonary tuberculosis face considerable ongoing morbidities, including respiratory impairment, psychosocial challenges, and reduced health-related quality of life after treatment completion. Given the important global and local burden of tuberculosis, as well as the estimated burden of PTLD, the development of a consensus document by a Brazilian scientific society—Sociedade Brasileira de Pneumologia e Tisiologia (SBPT)—was considered urgent for the prevention and management of this condition in order to allocate resources to and within tuberculosis services appropriately and serve as a guide for health care professionals. A team of eleven pulmonologists and one methodologist was created by the SBPT to review the current evidence on PTLD and develop recommendations adapted to the Brazilian context. The expert panel selected the topics on the basis of current evidence and international guidelines. During the first phase, three panel members drafted the recommendations, which were divided into three sections: definition and prevalence of PTLD, assessment of PTLD, and management of PTLD. In the second phase, all panel members reviewed, discussed, and revised the recommendations until a consensus was reached. The document was formally approved by the SBPT in a special session organized during the 2023 SBPT Annual Conference