Climate Change: Bridging Texas and São Paulo

Latin American Studie

Large time asymptotics for the fluctuation SPDE in the Kuramoto synchronization model

We investigate the long-time asymptotics of the fluctuation SPDE in the Kuramoto synchronization model. We establish the linear behavior for large time and weak disorder of the quenched limit fluctuations of the empirical measure of the particles around its McKean-Vlasov limit. This is carried out through a spectral analysis of the underlying unbounded evolution operator, using arguments of perturbation of self-adjoint operators and analytic semigroups. We state in particular a Jordan decomposition of the evolution operator which is the key point in order to show that the fluctuations of the disordered Kuramoto model are not self-averaging.Comment: 34 pages, 5 figures; V2: introduction simplified, references added and typos correcte

Bridging the Gap Between Energy and Climate Policies in Brazil: Policy Options to Reduce Energy-Related GHG Emissions

Brazil is facing a series of important policy decisions that will determine its energy future over the next several decades, with important implications for the country's economic competitiveness, the well-being of its citizens, and the global climate. The decisions concern the direction of approximately 0.5 trillion U.S. dollars of anticipated investment in energy infrastructure over the next decade -- which can either lock in carbon-intensive infrastructure, or advance Brazil's position as a leader in the low-carbon economy. This report examines Brazil's key energy-related GHG emitting sectors through a climate lens in order to offer recommendations for a more integrated approach that can more effectively reconcile energy and climate needs. It begins with an overview of Brazil's past energy and GHG emissions profiles, current pledges and future trends, and a discussion of the implications for a possible allocation of the remaining global carbon budget. Next, it reviews available scenarios for Brazil's energy-related GHG emissions in order to identify key drivers and results and compare them to a given allocation of the global carbon budget. It then focuses on the top emitting subsectors -- transport, industry, and power generation -- to identify key abatement opportunities. The report concludes with recommendations regarding a portfolio of policies and measures that could achieve both climate and energy objectives

Misure di tenacità a frattura su acciai utilizzando velocità di deformazione elevate

La conoscenza delle proprietà meccaniche di tipo dinamico per i materiali metallici è utile ogniqualvolta la sensibilità alla velocità di deformazione è di rilevanza per un acciaio, e qualora le condizionireali di carico per una struttura (in caso di normale esercizio o di situazioni d'emergenza) siano diverse dal caso statico. Inoltre, in alcuni studi l'aumento della velocità di deformazione serve a simulare gli effetti di altri meccanismi di fragilizzazione quali l'invecchiamento termico (thermal ageing) o l'irraggiamento.La presente memoria fornisce una panoramica dell'esperienza maturata al Centro Nucleare Belga (SCK•CEN) nel campo delle misure di tenacità a frattura su acciai in condizioni di velocità di deformazione elevata, con particolare riguardo alle prove di resilienza strumentata su provini Charpy precriccati (PCVN).Dopo una breve dissertazione sui meccanismi fondamentali che aiutano a comprendere gli effetti della velocità di deformazione sulla tenacità degli acciai in regime fragile e duttile, vengono presentate le procedure sperimentali ed analitiche per misurare la tenacità a frattura con velocità di deformazione elevata, prendendo in considerazione da un lato le principali normative internazionali (ASTM e ISO) e dall'altro il lavoro di normazione attualmente in corso sotto il coordinamento di SCK•CEN: la revisione della norma ASTM E1921 (metodo della Master Curve per la misura della tenacità in regime di transizione duttile/fragile) e lo sviluppo di una nuova norma ISO sulle prove di tenacità dinamica con provini PCVN. Quest'ultimo documento è presentato in maggior dettaglio, concentrando l'attenzione sulla determinazione della tenacità dinamica in campo fragile con il metodo dell'Impact Response Curve e in campo duttile (curve di esistenza J-R) mediante l'uso di metodi mono- e multi-campione.In conclusione, vengono presentati alcuni esempi tratti dalla banca dati sviluppata da SCK•CEN per le misure di tenacità dinamica, prevalentemente su acciai da vessel di uso nucleare (RPV steels)

Misure di tenacità a frattura su acciai utilizzando velocità di deformazione elevate

The knowlegde of dynamic mechanical properties is useful in all cases where the strain ratesensitivity of metallic materials is an issue, and whenever the actual loading conditions for a structure (eitherin normal operation or under accidental circumstances) are different from static. Furthermore, in someinvestigations increasing the loading rate is used to simulate other embrittling mechanisms such as thermalaging or neutron exposure.This paper provides an overview of SCK•CEN experience on measuring fracture toughness of steels at elevatedloading rates, with specific emphasis on instrumented impact tests on precracked Charpy (PCVN)specimens.After briefly dwelling on the basic mechanisms which explain loading rate effects on cleavage and ductilefracture toughness, the experimental and analytical procedures for measuring fracture toughness at elevatedloading rates are addressed, both in terms of official ASTM and ISO test standards and considering standardizationefforts currently in progress under SCK•CEN coordination: revision of ASTM E1921 (MasterCurve methodology for measuring fracture toughness in the ductile-to-brittle transition region) and a future ISO standard on instrumented PCVN testing. This latter document is examined in more detail, focussing theattention on the dynamic evaluation of brittle fracture toughness (Impact Response Curve) and the determinationof crack resistance curves using multiple and single-specimen techniques.Finally, selected examples from SCK•CEN database of dynamic toughness measurements will be illustrated,mainly relevant to reactor pressure vessel (RPV) steels

Complicação urológica após enxerto aorto-ilíaco: relato de caso e revisão de literatura

CONTEXT: Ureteral stenosis and ureterohydronephrosis may be serious complications of aortoiliac or aortofemoral reconstructive surgery. CASE REPORT: A 62-year-old female patient presented with a six-month history of left lumbar pain. She was a smoker, and had mild chronic arterial hypertension and Takayasu arteritis. She had previously undergone three vascular interventions. In two procedures, Dacron prostheses were necessary. Excretory urography showed moderate left ureterohydronephrosis and revealed a filling defect in the ureter close to where the iliac vessels cross. This finding was compatible with ureteral stenosis, and the aortoiliac graft may have been the reason for this inflammatory process. The patient underwent laparotomy, which showed that there was a relationship between the ureteral stenosis and the vascular prosthesis. Segmental ureterectomy and end-to-end ureteroplasty with the ureter crossing over the prosthesis anteriorly were performed. There were no complications. The early and late postoperative periods were uneventful. The patient evolved well and the results from a new excretory urogram were normal. We concluded that symptomatic ureterohydronephrosis following aortoiliac graft is a real complication and needs to be quickly diagnosed and treated by urologists.INTRODUÇÃO: Estenose ureteral e ureterohidronefrose podem ser sérias complicações da cirurgia reconstrutiva aorto-femoral ou aorto-ilíaca. RELATO DE CASO: Uma paciente de 62 anos apresentou-se referindo história de dor lombar a esquerda há seis meses. Ela era fumante, portadora de hipertensão arterial crônica leve e arterite de Takayasu. Havia sido submetida a três intervenções vasculares. Em dois procedimentos o uso de prótese de Dacron foi necessário. Uma urografia excretora revelou moderada ureterohidronefrose à esquerda e falha de enchimento no ureter próximo ao cruzamento dos vasos ilíacos. Esse achado era compatível com uma estenose ureteral e o enxerto aorto-ilíaco poderia ser a causa do processo inflamatório. A paciente foi submetida a laparotomia, que evidenciou a relação entre estenose ureteral e a prótese vascular. Ureterectomia segmentar e uretroplastia término-terminal com o ureter passando anteriormente à prótese foram realizadas. Não ocorreram complicações. Os períodos de pós-operatório precoce e tardio transcorreram sem intercorrências. A paciente evoluiu bem e uma nova urografia excretora apresenta-se normal. Concluímos que ureterohidronefrose sintomática após enxerto aorto-ilíaco é uma complicação real e precisa ser rapidamente diagnosticada e tratada pelo urologista