Exergy analysis of a PWR nuclear steam supply system – Part I, general theoretical model

The paper provides an alternative, novel methodology to perform the exergetic analysis of a Pressurized Nuclear Reactor (PWR) based on the strictest definition of fission temperature to get to a careful evaluation of Exergy Destruction and exergetic Efficiency of the component. Up today, the exegetic analyses of Nuclear Power Plants (NPP) have been based on the assumption that Fission Exergy and Fission Energy are almost the same having assumed Carnot Factor almost equal to 1 as Tfiss >>T0. This assumption is based on some simplified hypotheses concerning fission temperature as applied in the definition of the Fission Exergy itself, whose value, to the best knowledge of the authors, was never modeled. On the contrary, in the first part of the paper, the authors present the results of an ongoing research, just aimed at evaluating the Exergy efficiency of the heat exchange in a PWR reactor, whose first results were already presented in [1], based on the most detailed modeling of Tfiss. The modeling, referring to a steady-state operational mode of the Reactor, takes into account all heat transfer phenomena between nuclear fuel UO2, its Zircaloy clad, cooling water, vessel material and the external environment. In the second part of the paper, the Exergy analysis is extended to all main Reactor Cooling System components (Vertical recirculating type Steam Generator, primary coolant pump and piping) with the aim to compare the Exergy Destructions and exergetic Efficiencies of the RPV with those of the other components of the Nuclear Steam Supply System, NSSS. In the Part II of the same paper,, "Exergy Analysis of a PWR Nuclear Steam Supply System - II part: a case study ", a test case is exemplified with the aim to compare the results obtained applying the methodology in question with those obtained applying the most established methodology adopted by other authors

Exergy analysis of a PWR nuclear steam supply system - II part: a case study

The paper shows the results of the exergetic analysis of the Nuclear Steam Supply System (NSSS) of the MARS Pressurized Light Water Reactor using the theoretical methodology described in the authors’ previous works [1] and [2]. The analysis firstly aims at a novel assessment of the irreversibilities occurred in the nuclear reactor vessel to compare the results, in terms of Exergy Destruction and exergetic Efficiency, with those obtained adopting one of the most employed methodology as reference. The comparison showed that a detailed exergetic analysis, mainly aimed to strictly assess the fission temperature, can lead to a higher estimate of the PWR exergetic Efficiency values

Exergy analysis of a PWR core heat transfer

The exergetic analysis, a methodology of thermodynamics that quantifies of energy losses associated with irreversibility, allows to optimize the efficiencies of the various stages of a transformation process and thus its overall efficiency. In this contribution, a novel approach to the exergetic analysis is applied to the energy transformations taking place within the core of a nuclear reactor. To perform such analysis, reference was made to a pressurized light-water reactor (PWR), modeling the heat exchanges between the fuel assemblies and the coolant fluid in the core through the balance of incoming and outgoing mass and energy flows, incoming and outgoing the reactor. The results of the analysis are validated through a comparison with the actual reactor operating parameters. The main goals of the work –part of a wider ongoing research effort- are to develop the thermo-economic analysis of a PWR nuclear power plant (NPP) to assess the actual cost of the products obtainable downstream of the NPP (electric energy and thermal energy for industrial and civil users, very different products in terms of exergy contents), and to compare with the costs of similar products obtained from conventional thermal power plants

an spm po based polarimetrie two scale model

AbstractA polarimetric two-scale scattering model employed to retrieve the surface parameters of bare soils from polarimetric SAR data is presented. The scattering surface is here considered as composed of randomly tilted rough facets, for which the SPM or the PO hold. The facet random tilt causes a random variation of the local incidence angle, and a random rotation of the local incidence plane around the line-of-sight, which in turn causes a random rotation of the facet scattering matrix. Unlike other similar already existing approaches, our method considers both these effects. The proposed scattering model is then used to retrieve bare soil moisture and large-scale roughness from the co-polarized and cross-polarized ratios

A novel combination of triple metachronous malignancies of the kidney, oropharynx and prostate. A case report

Synchronous or metachronous malignancies are a rare event, with an incidence rate that increases with age. The present study reports the case of a 70-year-old Caucasian male who was referred to the outpatient office of the Urology Unit, Sapienza University of Rome (Latina, Italy) due to lower urinary tract symptoms. An abdominal ultrasound investigation was performed that demonstrated the presence of a right renal mass. The patient underwent right radical nephrectomy, which resulted in the definitive diagnosis of clear cell type renal cell carcinoma. The patient was eventually diagnosed with triple primary metachronous cancer consisting of renal clear cell carcinoma, prostate adenocarcinoma and squamous cell carcinoma of the oropharynx (palatine tonsil). To the best of our knowledge, this combination of primary neoplasms has not previously been documented

MOVEMENT EDUCATION AT THE CENTER OF THE SCHOOL

In this study, the reader’s attention is drawn to the importance of movement education and its central role in the school. The latter is, together with the family, the institution organized according to rules, with the aim of educating, teaching and training students from three to eighteen years of age. A continuous training process that develops in the sensitive stages of growth. The role of the school in our society is fundamental, and we have witnessed it especially in this last year during which we have been hit by a violent pandemic event, forcing us to avoid social contacts; consequently, even the school has been conditioned to the point of stopping classroom activities. But in spite of this, we have never thought for a moment about interrupting the teacher-learner relationship, employing what everybody knows as distance learning, so as not to break the <> between people. This is a fundamental aspect of the project “La Scuola al Centro” (The Centrality of the School), in which, through the movement, the body is considered a resource for the structuring of the self and of learning processes; all this while also providing, through the design of educational and inclusive paths, the possibility of building, discovering and learning about the individual, as well as of building a more sustainable future based on equality in diversity

Scientific, Technical and Economic Committee for Fisheries (STECF) - Report of the Workshop on Mediterranean Stock Assessment Standardization SGMED Workshop 09-01 (Formerly Labeled as SG-ECA/RST/MED 09-01)

SG-ECA/RST/MED 09-01 was held in San Pedro del Pinatar, Murcia (Spain), on 2-6 March 2009. The aim of the workshop was to agree about certain standardizations of the working procedures applied by the new STECF assessment working group regarding living marine resources in the Mediterranean. STECF reviewed the report during its Plenary meeting on 20-24 April 2009.JRC.G.4-Maritime affair

ESGTech: Guiding ESG Regulation and Digital Governance

The role of technology in shaping regulatory processes has been widely studied in the field of digital governance. This research complements such literature by exposing how data technologies are shaping the regulatory trajectory of environmental, social and governance (ESG) issues. The paper discusses the regulatory challenges surrounding ESG and the position that data technologies have assumed in addressing such issues. The case explored with this research is Bloomberg’s methodology for proprietary ES Scores. This study contributes to the e-government literature by emphasising how the absence of law both accelerates and constrains the scope of technology and how technology alleviates regulatory concerns whilst also assuming governing properties. This paper offers valuable insights into the complex production of ESG data and contributes with an imperative of ESGTech in guiding digital governance

Oncogenic microRNAs characterization in clear cell renal cell carcinoma

A key challenge for the improvement of clear cell renal cell carcinoma (ccRCC) management could derive from a deeper characterization of the biology of these neoplasms that could greatly improve the diagnosis, prognosis and treatment choice. The aim of this study was to identify specific miRNAs that are deregulated in tumor vs. normal kidney tissues and that could impact on the biology of ccRCC. To this end we selected four miRNAs (miR-21-5p, miR-210-3p, miR-185-5p and miR-221-3p) and their expression has been evaluated in a retrospective cohort of formalin-fixed paraffin-embedded (FFPE) tissues from 20 ccRCC patients who underwent surgical nephrectomy resection. miR-21-5p and miR-210-3p resulted the most significantly up-regulated miRNAs in this patient cohort, highlighting these onco-miRNAs as possible relevant players involved in ccRCC tumorigenesis. Thus, this study reports the identification of specific oncogenic miRNAs that are altered in ccRCC tissues and suggests that they might be useful biomarkers in ccRCC management

Secreted miR-210-3p as non-invasive biomarker in clear cell renal cell carcinoma

The most common subtype of renal cell carcinoma (RCC) is clear cell RCC (ccRCC). It accounts for 70-80% of all renal malignancies representing the third most common urological cancer after prostate and bladder cancer. The identification of non-invasive biomarkers for the diagnosis and responsiveness to therapy of ccRCC may represent a relevant step-forward in ccRCC management. The aim of this study is to evaluate whether specific miRNAs deregulated in ccRCC tissues present altered levels also in urine specimens. To this end we first assessed that miR-21-5p, miR-210-3p and miR-221-3p resulted upregulated in ccRCC fresh frozen tissues compared to matched normal counterparts. Next, we evidenced that miR-210-3p resulted significantly upregulated in 38 urine specimens collected from two independent cohorts of ccRCC patients at the time of surgery compared to healthy donors samples. Of note, miR- 210-3p levels resulted significantly reduced in follow-up samples. These results point to miR-210-3p as a potential non-invasive biomarker useful not only for diagnosis but also for the assessment of complete resection or response to treatment in ccRCC management