Mixed Layer formation and restratification in presence of mesoscale and submesoscale turbulence

Recent realistic high resolution modeling studies show a net increase of submesoscale activity in fall and winter when the mixed layer depth is at its maximum. This submesoscale activity increase is associated with a reduced deepening of the mixed layer. Both phenomena can be related to the development of mixed layer instabilities, which convert available potential energy into submesoscale eddy kinetic energy and contribute to a fast restratification by slumping the horizontal density gradient in the mixed layer. In the present work, the mixed layer formation and restratification was studied by uniformly cooling a fully turbulent zonal jet in a periodic channel at different resolutions, from eddy resolving (10 km) to submesoscale permitting (2 km). The effect of the submesoscale activity, highlighted by these different horizontal resolutions, was quantified in terms of mixed layer depth, restratification rate and buoyancy fluxes. Contrary to many idealized studies focusing on the restratification phase only, this study addresses a continuous event of mixed layer formation followed by its complete restratification. The robustness of the present results was established by ensemble simulations. The results show that, at higher resolution, when submesoscale starts to be resolved, the mixed layer formed during the surface cooling is significantly shallower and the total restratification almost three times faster. Such differences between coarse and fine resolution models are consistent with the submesoscale upward buoyancy flux, which balances the convection during the formation phase and accelerates the restratification once the surface cooling is stopped. This submesoscale buoyancy flux is active even below the mixed layer. Our simulations show that mesoscale dynamics also cause restratification, but on longer time scales. Finally, the spatial distribution of the mixed layer depth is highly heterogeneous in the presence of submesoscale activity, prompting the question of whether it is possible to parameterize submesoscale effects and their effects on the marine biology as a function of a spatially-averaged mixed layer depth.

The emergence and evolution of optimistic expectations in schoolchildren

When we study optimism in children, we note the temporary emergence of a bias that leads them to make optimistic predictions. In this study we intend to learn more about changes that can be observed in the optimistic bias of 6- to 12-year old schoolchildren when they predict future events, and in the way they justify those predictions. A total of 77 pupils participated in this study; we evaluated each one of them individually with a Piagetian interview, asking them to formulate predictions about a series of hypothetical situations. After analyzing whether a child's prediction implied that the situation would maintain itself or would change for better or for worse, we classified the justifications they provided for their predictions. Results show that these subjects regarded positive change as more likely in the case of psychological or hybrid events than for purely biological ones, and that younger children tended to display a greater bias in favor of the likelihood of positive change. These younger children justified their predictions stating that nature or the passing of time could be responsible for the changes, without needing further intervention on the part of other agents. Older children, on the other hand, tended to provide similar kinds of explanations to justify their expectation of stasis.

Close-in planets around giant stars: lack of hot-Jupiters and prevalence of multiplanetary systems

Extrasolar planets abound in almost any possible configuration. However, until five years ago, there was a lack of planets orbiting closer than 0.5 au to giant or subgiant stars. Since then, recent detections have started to populated this regime by confirming 13 planetary systems. We discuss the properties of these systems in terms of their formation and evolution off the main sequence. Interestingly, we find that 70.0 ± 6.6% of the planets in this regime are inner components of multiplanetary systems. This value is 4.2σ higher than for main-sequence hosts, which we find to be 42.4 ± 0.1%. The properties of the known planets seem to indicate that the closest-in planets (a< 0.06 au) to main-sequence stars are massive (i.e., hot Jupiters) and isolated and that they are subsequently engulfed by their host as it evolves to the red giant branch, leaving only the predominant population of multiplanetary systems in orbits 0.06 formation and evolution of hot Jupiters.

Dust recovery practice at blast furnaces; an evaluation of settleable solids formation and recovery at mills in the Ohio Valley and a suggested proceedure [sic] for defining performance of wastewater clarifiers.

"Reference data publication."

Acuerdo Marco de Cooperación entre la Universidad de Cuenca (Ecuador) y el A.N. Severtsov Institute of Ecology and Evolution (Moscow, Russia)

Español

Natural Disasters and Comparative State-Formation and Nation-Building: Earthquakes in Argentina and Chile (1822-1939)

Natural disasters in Argentina and Chile played a significant role in the state-formation and nation-building process (1822-1939). This dissertation explores state and society responses to earthquakes by studying public and private relief efforts reconstruction plans, crime and disorder, religious interpretations of catastrophes, national and transnational cultures of disaster, science and technology, and popular politics. Although Argentina and Chile share a political border and geological boundary, the two countries provide contrasting examples of state formation. Most disaster relief and reconstruction efforts emanated from the centralized Chilean state in Santiago. In Argentina, provincial officials made the majority of decisions in a catastrophe’s aftermath. Patriotic citizens raised money and collected clothing for survivors that helped to weave divergent regions together into a nation. The shared experience of earthquakes in all regions of Chile created a national disaster culture. Similarly, common disaster experiences, reciprocal relief efforts, and aid commissions linked Chileans with Western Argentine societies and generated a transnational disaster culture. Political leaders viewed reconstruction as opportunities to implement their visions for the nation on the urban landscape. These rebuilding projects threatened existing social hierarchies and often failed to come to fruition. Rebuilding brought new technologies from Europe to the Southern Cone. New building materials and systems, however, had to be adapted to the South American economic and natural environment. In a catastrophe’s aftermath, newspapers projected images of disorder and the authorities feared lawlessness and social unrest. Judicial and criminal records, however, show that crime often decreased after a disaster. Finally, nineteenth-century earthquakes heightened antagonism and conflict between the Catholic Church and the state. Conservative clergy asserted that disasters were divine punishments for the state’s anti-clerical measures and later railed against scientific explanations of earthquakes.

New Political Parties as Innovators - Formation and Success

This cumulative dissertation investigates the formation and success of new political parties in developed democracies from the perspective of the programmatic competition between parties (see. introduction in chapter 1). It starts by arguing that the current state of the programmatic supply by existing parties is a central determinant for the likelihood of new party formation (chapter 2). A low programmatic diversity of existing parties creates scope for programmatic innovations by new parties. The dissertation establishes a connection between the literature on new parties and niche parties by analyzing the latter as typical cases of innovating new parties (chapter 3). For this purpose, the author combines two concepts with corresponding measures in order to capture the programmatic profiles of parties. Nicheness refers to differences in the emphasis of topics between a given party and its counterparts while programmatic concentration shows the narrowness of a given policy profile. Chapter 4 investigates how the variation in the programmatic profiles of niche parties affect their long-term electoral performance. Previous studies on niche parties have not fully taken into account the evolutionary aspect of the programmatic profiles of these parties. Acknowledging the variation in programmatic profiles between niche parties and over time, the article argues that the electoral effects of nicheness and programmatic concentration as programmatic features of niche parties vary over their lifecycle. The literature on new parties assumes that they can benefit from the poor representation of parts of the electorate by existing parties. This strand of research provides plausible results, but it operates on the macro level, which is problematic for theoretical and methodological reasons. The study in chapter 5 overcomes these problems through a multilevel analysis of the vote choice between new parties, existing parties and abstention.

Keys on the Formation and Human Development in Pedagogy

This paper is based on the experiences of the author, who has worked in the various levels of the Venezuelan educational system. This has been a very important platform to understand the ideas of education and human development within the Venezuelan institutionality in the educational field. The idea of education that we have, as teachers, should be rethought in order to consider the personal stories of those who share with us their time, interests and willingness: children, young people or adults, all with particular identities, differences and coincidences. The teachers, the schools and the State cannot consider an education for someone they do not know. In this sense, we provide some reflections resulting from our ethnographic work, based on the school life, interviews, class analysis, observations, and stories, among others. Our thoughts are classified as formation, hope, dialogue, attitude, and school life.

Diffusive models and chaos indicators for non-linear betatron motion in circular hadron accelerators

Understanding the complex dynamics of beam-halo formation and evolution in circular particle accelerators is crucial for the design of current and future rings, particularly those utilizing superconducting magnets such as the CERN Large Hadron Collider (LHC), its luminosity upgrade HL-LHC, and the proposed Future Circular Hadron Collider (FCC-hh). A recent diffusive framework, which describes the evolution of the beam distribution by means of a Fokker-Planck equation, with diffusion coefficient derived from the Nekhoroshev theorem, has been proposed to describe the long-term behaviour of beam dynamics and particle losses. In this thesis, we discuss the theoretical foundations of this framework, and propose the implementation of an original measurement protocol based on collimator scans in view of measuring the Nekhoroshev-like diffusive coefficient by means of beam loss data. The available LHC collimator scan data, unfortunately collected without the proposed measurement protocol, have been successfully analysed using the proposed framework. This approach is also applied to datasets from detailed measurements of the impact on the beam losses of so-called long-range beam-beam compensators also at the LHC. Furthermore, dynamic indicators have been studied as a tool for exploring the phase-space properties of realistic accelerator lattices in single-particle tracking simulations. By first examining the classification performance of known and new indicators in detecting the chaotic character of initial conditions for a modulated Hénon map and then applying this knowledge to study the properties of realistic accelerator lattices, we tried to identify a connection between the presence of chaotic regions in the phase space and Nekhoroshev-like diffusive behaviour, providing new tools to the accelerator physics community.

Constraining FIR size, dust temperature and dust mass in ALPINE galaxies at redshift 4

The study of galaxies at high redshift plays a crucial role to understand the mechanism of galaxy formation and evolution. At redshifts just after the epoch of re-ionization (4and progressively become more obscured due to increased dust attenuation of the UV light. Therefore, determining physical parameters regarding dust is essential to trace the history of the star formation rate (SFR). The main purpose of this thesis is to determine the spatial extent of the dust emission in high-redshift galaxies and to provide a lower limit on dust temperature, to constrain the dust mass. This is achieved by studying 23 FIR continuum detected main-sequence galaxies of the ALMA Large Program to INvestigate (ALPINE) survey, performed at high redshift (4and gas distribution, traced by the UV and [CII] emission, respectively. Finally, we put these results in a broader context, by studying the dust size evolution as a function of cosmic time. We derive dust size measurements via a Gaussian fit in the image and uv plane. Out of the 23 FIR-continuum-detected targets, 20 have been considered in this work since they are isolated systems. Of these 20, 7 are spatially resolved; for each of the remaining 13, we provide an upper limit to the dust size. We find that the gas emission is more extended than the dust spatial scale, by a factor of 1.40±0.29, while the latter appears to be larger than the stellar emission size. Moreover, we do not find any significant trend for dust size as a function of the stellar mass and the redshift. In addition, we provide a minimum dust temperature estimate for the 7 resolved sources, for which we find Tmin∼16−19K. We also derive dust masses for the resolved sources, logMdust∼7−8M⊙.

Estudo do mecanismo de corrosão por pites em água do mar de aços inoxidáveis supermartensíticos microligados com Nb e Ti

Os aços inoxidáveis supermartensíticos (SMSS) são usados em ambientes agressivos devido à sua boa soldabilidade, boas propriedades mecânicas em temperaturas elevadas e superior resistência à corrosão sob tensão. Aplicações na exploração de petróleo demandam superior combinação de propriedades e os aços inoxidáveis duplex e superduplex têm sido aplicados nessa área, a despeito de seus custos elevados. Os SMSS consistem numa alternativa técnica e econômica ao uso daqueles aços. Nesse trabalho, adições de Nb e Ti foram realizadas com o intuito de minimizar o efeito de sensitização, promover o refino de grãos e foram estudados os aspectos microestruturais e a resistência à corrosão por pites em água do mar. A formação e a evolução dos pites foram acompanhadas por ensaios de corrosão, microscopia óptica e eletrônica, focalizando suas morfologias. O aço com Ti apresentou o melhor desempenho quanto à corrosão, com o maior potencial de corrosão e menor potencial de pite entre os aços em estudo. O aço com Nb, apesar de apresentar potencial de corrosão superior ao do aço sem adição, teve um potencial de pite inferior ao do mesmo.

Behavior of argon gas release from manganese oxide minerals as revealed by Ar-40/Ar-39 laser incremental heating analysis

Manganese oxides in association with paleo-weathering may provide significant insights into the multiple factors affecting the formation and evolution of weathering profiles, such as temperature, precipitation, and biodiversity. Laser probe step-heating analysis of supergene hollandite and cryptomelane samples collected from central Queensland, Australia, yield well-defined plateaus and consistent isochron ages, confirming the feasibility, dating very-fined supergene manganese oxides by Ar-40/(39) Ar technique. Two distinct structural sites hosting Ar isotopes can be identified in light of their degassing behaviors obtained by incremental heating analyses. The first site, releasing its gas fraction at the laser power 0.2-0.4 W, yields primarily Ar-40(atm), Ar-38(atm), and Ar-36(atm), (atmospheric Ar isotopes). The second sites yield predominantly Ar-40* (radiogenic Ar-40), Ar-39(K), and Ar-38(K) (nucleogenic components), at similar to0.5-1.0 W. There is no significant Ar gas released at the laser power higher than 1.0 W, indicating the breakdown of the tunnel sites hosting the radiogenic and nucleogenic components. The excellent match between the degassing behaviors of Ar-40*, Ar-39(K), and Ar-38(K) suggests that these isotopes occupy the same crystallographic sites and that Ar-39(K) loss from the tunnel site by recoil during neutron irradiation and/or bake-out procedure preceding isotopic analysis does not occur. Present investigation supports that neither the overwhelming atmospheric Ar-40 nor the very-fined nature of the supergene manganese oxides poses problems in extracting meaningful weathering geo-chronological information by analyzing supergene manganese oxides minerals.