On the thermal dynamic behaviour of the helium-cooled DEMO fusion reactor

The EU-DEMO conceptual design is being conducted among research institutions and universities from 26 countries of European Union, Switzerland and Ukraine. Its mission is to realise electricity from nuclear fusion reaction by 2050. As DEMO has been conceived to deliver net electricity to the grid, the choice of the Breeding Blanket (BB) coolant plays a pivotal role in the reactor design having a strong influence on plant operation, safety and maintenance. In particular, due to the pulsed nature of the heat source, the Primary Heat Transfer System (PHTS) becomes a very important actor of the Balance of Plant (BoP) together with the Power Conversion System (PCS). Moreover, aiming to mitigate the potential negative impact of plasma pulsing on BoP equipment, for the DEMO plant is also being investigated a "heat transfer chain" option which envisages an Intermediate Heat Transfer System (IHTS) equipped with an Energy Storage System (ESS) between PHTS and PCS. Within this framework, a preliminary study has been carried out to analyse the thermal dynamic behaviour of the IHTS system for the Helium-Cooled Pebble Bed (HCPB) BB concept during pulse/dwell transition which should be still considered as the normal operating mode of a fusion power plant. Starting from preliminary thermal-hydraulic calculations made in order to size the main BoP components, the global performances of DEMO BoP have been quantitatively assessed focusing the attention on the attitude of the whole IHTS to smooth the sudden power variations which come from the plasma. The paper describes criteria and rationale followed to develop a numerical model which manages to simulate simple transient scenarios of DEMO BoP. Results of numerical simulations are presented and critically discussed in order to point out the main issues that DEMO BoP has to overcome to achieve a viable electricity power output

A cellular automaton for the factor of safety field in landslides modeling

Landslide inventories show that the statistical distribution of the area of recorded events is well described by a power law over a range of decades. To understand these distributions, we consider a cellular automaton to model a time and position dependent factor of safety. The model is able to reproduce the complex structure of landslide distribution, as experimentally reported. In particular, we investigate the role of the rate of change of the system dynamical variables, induced by an external drive, on landslide modeling and its implications on hazard assessment. As the rate is increased, the model has a crossover from a critical regime with power-laws to non power-law behaviors. We suggest that the detection of patterns of correlated domains in monitored regions can be crucial to identify the response of the system to perturbations, i.e., for hazard assessment.Comment: 4 pages, 3 figure

Propiedades de transporte de hormigón con cemento puzolánico

Existen estructuras emplazadas en medios agresivos que requieren una adecuada resistencia al ingreso de agentes agresivos para completar su vida útil con un nivel aceptable de serviciabilidad. Adicionalmente a las buenas prácticas constructivas, resulta necesario trabajar sobre el diseño de la mezcla de hormigón, de manera de lograr óptimos resultados a un costo menor. El cemento portland puzolánico (CPP) aparece como una de las opciones más apropiadas conjugando durabilidad y economía. El presente trabajo tiene como objetivo evaluar distintas propiedades relacionadas con la penetrabilidad de agentes externos a la estructura porosa de hormigones de distinto nivel resistente elaborados con cemento CPP. Se utilizaron método de ensayo para la evaluación del transporte de líquidos y gases, tales como el de penetración de agua a presión, absorción capilar, permeabilidad al aire y migración de cloruro. Los resultados obtenidos a 28 días, mostraron efectos sumamente positivos de la acción puzolánica de la adición como reemplazo parcial del clínquer, resaltando la potencialidad del uso del cemento CPP para ambientes agresivos.Concrete structures located in aggressive environments must have enough resistance against the ingress of aggressive agents so that they can achieve their service life with acceptable serviceability. In addition to suitable construction practices, concrete mix design must be studied to achieve the best results at low cost. Pozzolanic Portland cement (PPC) seems one of the most appropriate options, which combines durability and economy. This paper aims to evaluate properties related to the penetration of external agents through the pore structure of PPC concrete with dissimilar strength levels. Liquid and gas transport was evaluated by tests methods such as water penetration under pressure, sorptivity, air permeability and chloride migration. At 28 days, the obtained results showed very positive pozzolanic effect of the admixture as partial replacement of clinker, which shows the potentiality of using PPC for aggressive environments

Money management and entrepreneurial training in microfinance: impact on beneficiaries and institutions

This study uses a randomized control trial to evaluate the outcome of integrating money management and entrepreneurial training into a microcredit program in India. We find positive and significant effects on clients\u2019 financial management skills and entrepreneurship abilities, particularly for clients with higher human capital, or more diligent, or having an entrepreneurial idea, and an increase in initiative and self-confidence. Effects appear stronger for clients obliged to attend the training course or more interested in attending it. By considering missed or delayed repayments reduction we assess the benefits of the training provided and of extending it for the institution

Are Bankers “Crying Wolf”? Type I, Type II Errors and Deterrence in Anti-Money Laundering: The Italian Case

Excessive and useless reporting, called the "crying wolf effect," is a crucial shortcoming that any anti-money laundering (AML) design aims to address. For this reason, in recent years, AML policies in both the US and Europe have switched from a rule-based to a risk-based approach. This study theoretically and empirically investigates whether the risk-based approach delivers the expected results. The theoretical model shows that a trade-off can emerge between accuracy (fewer type-I and type-II errors) and deterrence. The empirical analysis, conducted after the risk-based approach was introduced in Italy, confirms this trade-off. More specifically, deterrence seems a priority, whereas accuracy is sacrificed. In this respect, the data suggest that Italian bankers are likely to "cry wolf.

Resistance-based probabilistic design by order statistics for an oil and gas deep-water well casing string affected by wear during kick load

Deep-water wells for oil and gas extraction make structural components, such as casing and tubing, work in extremely harsh environmental conditions that accelerate component degradation and increase failure probability. Therefore, it is important to properly design casing strings under these operative circumstances (Baraldi et al., 2012)

Immune checkpoint inhibitors in oncogene-addicted non-small cell lung cancer: A systematic review and meta-analysis

Background: Treatment of oncogene-addicted non-small cell lung cancer (NSCLC) has been changed by the advent of tyrosine kinase inhibitors (TKIs). Albeit great benefits are achieved with target therapies, resistance invariably occurs and recourse to alternative treatments is unavoidable. Immune checkpoint inhibitors (ICIs) role and the best setting of immunotherapy administration in oncogene-driven NSCLC are matter of debate. Methods: We performed a systematic literature review through PubMed, in order to gather all the available information regarding ICI activity and efficacy in oncogene-addicted NSCLC, from both prospective trials and retrospective series. A meta-analysis of objective response rate in different molecular subgroups was provided. Combinatorial strategies including ICIs and related toxicities were also recorded. Results: Eighty-seven studies were included in the qualitative analysis. EGFR mutation may be a biomarker of poor response to single-agent ICIs (7% of EGFR-mutant NSCLC patients achieved disease response in prospective trials), while encouraging results have been shown with combination strategies. KRASmutated disease (response rate, RR, 22%) has different clinical and pathological characteristics, and the coexistence of additional mutations (e.g., STK11 or TP53) influence tumor microenvironment and response to immunotherapy. Other molecular alterations have been marginally considered prospectively, and data from clinical practice are variegated, given poor effectiveness of ICIs in ALK-rearranged disease (RR 9.5%, pooling the data of retrospective studies) or some encouraging results in BRAF-(RR 25%, retrospective data) or MET-driven one (with estimations conditioned by the presence of both exon 14 skipping mutations and gene amplification in reported series). Conclusions: In oncogene-addicted NSCLC (with the exception of KRAS-mutated), ICIs are usually administered at the failure of other treatment options, but administering single-agent immunotherapy in later disease phases may limit its efficacy. With the progressive administration of TKIs and ICIs in early-stage disease, molecular characterization will become fundamental in this setting