4,351 research outputs found
Ancore antiche: origine ed evoluzione.
Questa ricerca vuole contribuire ad offrire una panoramica, quanto più completa, sull'origine e l'evoluzione delle ancore, offrendo una classificazione tipologica e cronologica attraverso la descrizione delle fondamentali caratteristiche fisiche che permettono di individuare specifiche categorie di appartenenza.
Il primo capito è dedicato alla nascita delle primordiali ancore litiche a gravità, analizzando le ancore “a rocchetto” e “a ciambella”, le pietre forate, i killicks e i primi ceppi litici.
Nel secondo capitolo l'attenzione si sposta sulla nascita e la diffusione delle ancore a presa, distinguibili attraverso il tipo di materiale utilizzato (legno, piombo e ferro) e attraverso il tipo di ceppo (mobile o fisso). Vengono menzionate, per concludere, le tipologie di ancore “a presa” particolari e quelle moderne.
Per ogni classe analizzata vengono forniti una descrizione delle principali caratteristiche, una possibile datazione del periodo di utilizzo e alcuni esempi di ritrovamenti di particolare interesse o riferibili a contesti databili.
È stata dedicata attenzione all'analisi dell'ancora nei suoi aspetti decorativi, con particolare riferimento al ceppo d'ancora del Museo Civico di Rosignano Marittimo (Livorno).
Il terzo capitolo è dedicato al territorio pisano e all'analisi delle due ancore ritrovate negli scavi del Cantiere delle Navi Antiche di Pisa, è stata elaborata una scheda con le misure e le caratteristiche strutturali delle ancore ed è stata proposta una possibile datazione attraverso lo studio del contesto di ritrovamento e il confronto con manufatti con caratteristiche simili e databili con maggiore sicurezza.
Uno dei principali problemi riscontrati durante lo svolgimento di questa ricerca è quello relativo alla nomenclatura da utilizzare per distinguere le parti costituenti l'ancora; a tal proposito, sono stati inseriti una descrizione per quanto concerne la terminologia utilizzata ed un glossario comparativo dei termini principali in inglese, francese e spagnolo incontrati durante la ricerca
PERCEVAL
La station PERCEVAL permet de tester jusqu'à 16 sujets simultanément. Elle a été développée pour répondre à la grande demande de test d'intelligibilité.Conçue autour d'un PC dans l'environnement WINDOWS, elle permet de répondre rapidement à des contrats (C. Cavé et al).ANDRÉ, C.; GHIO, A.; CAVÉ, C.; TESTON, B. PERCEVAL: a Computer-Driven System for Experimentation on Auditory and Visual Perception. Proceedings of XVth ICPhS (2003 August 3-9 : Barcelona, Spain). 2003, p.1421-1424.http://hal.archives-ouvertes.fr/hal-00142980GHIO, A.; ANDRÉ, C.; TESTON, B.; CAVÉ, C. PERCEVAL: une station automatisée de tests de PERCeption et d'EVALuation auditive et visuelle. Travaux Interdisciplinaires du Laboratoire Parole et Langage d'Aix-en-Provence (TIPA), vol. 22. 2003, p. 115-133. ISSN 1621-0360.http://hal.archives-ouvertes.fr/hal-0013419
National Report for France
This chapter investigates the treatment of executory contracts under French corporate insolvency law.
While the French Commercial Code does not provide a definition of the concept of executory contracts, it is generally assumed that insolvency proceedings do not result in the automatic termination of the debtor’s executory contracts. Hence, executory contracts remain binding on both parties pending their assumption or rejection by the insolvency official. As certain types of executory contracts are deemed to justify special treatment in insolvency proceedings, the chapter investigates their treatment under the law.
The chapter also investigates the treatment of contractual remedies in insolvency law, such as ipso facto clauses, close-out netting provisions and flip clauses. Finally, the chapter analyses the most recent reforms in the corporate insolvency field and the drivers behind these regulatory changes.
The report concludes that the most recent reforms have improved the balance between debtor and creditor protection: France is now a more investor-friendly jurisdiction, while debtors benefit from a more sophisticated set of tools
Multipartite entanglement detection for hypergraph states
We study the entanglement properties of quantum hypergraph states of
qubits, focusing on multipartite entanglement. We compute multipartite
entanglement for hypergraph states with a single hyperedge of maximum
cardinality, for hypergraph states endowed with all possible hyperedges of
cardinality equal to and for those hypergraph states with all possible
hyperedges of cardinality greater than or equal to . We then find a lower
bound to the multipartite entanglement of a generic quantum hypergraph state.
We finally apply the multipartite entanglement results to the construction of
entanglement witness operators, able to detect genuine multipartite
entanglement in the neighbourhood of a given hypergraph state. We first build
entanglement witnesses of the projective type, then propose a class of
witnesses based on the stabilizer formalism, hence called stabilizer witnesses,
able to reduce the experimental effort from an exponential to a linear growth
in the number of local measurement settings with the number of qubits
Chronic pain assessments in children and adolescents : a systematic literature review of the selection, administration, interpretation, and reporting of unidimensional pain intensity scales
Background. Advances in pain assessment approaches now indicate which measures should be used to capture chronic pain experiences in children and adolescents. However, there is little guidance on how these tools should best be administered and reported, such as which time frames to use or how pain scores are categorised as mild, moderate, or severe. Objective. To synthesise current evidence on unidimensional, single-item pain intensity scale selection, administration, interpretation, and reporting. Methods. Databases were searched (inception: 18 January 2016) for studies in which unidimensional pain intensity assessments were used with children and adolescents with chronic pain. Ten quality criteria were developed by modifying existing recommendations to evaluate the quality of administration of pain scales most commonly used with children. Results. Forty-six studies met the inclusion criteria. The highest score achieved was 7 out of a possible 10 (median: 5; IQR: 4–6). Usage of scales varied markedly in administrator/completer, highest anchors, number of successive assessments, and time referent periods used. Conclusions. Findings suggest these scales are selected, administered, and interpreted inconsistently, even in studies of the same type. Furthermore, methods of administration are rarely reported or justified making it impossible to compare findings across studies. This article concludes by recommending criteria for the future reporting of paediatric chronic pain assessments in studies
Transport of fine sediment in vegetated flows
Complex interactions and turbulent flow structures take place across the interface, between vegetated regions and unobstructed main channel flow. For instance, in partly vegetated flows, different transport processes and sediment deposition affect the availability of nutrients and presence of pollutants. Within the vegetation, the turbidity is altered, influencing light accessibility and photosynthesis. The goal of this thesis is to improve knowledge on turbulent flow and fine sediment transport in partly vegetated flows. Experiments were carried out in the Aalto Environmental Hydraulics Lab:~60% of the flume width was unvegetated, while ~40% of the flume width was covered by a vegetated patch comprised of understory grass mat and artificial emergent flexible natural-like plants.
The experiments used a combination of vegetation density and plant properties, well representative of conditions found in natural riverine flows. Instantaneous 3D velocities, suspended sediment concentration (SSC) and net deposition were measured in the fully developed flow region of the vegetated patch. Two transverse transects and several vertical profiles were measured. Two vegetation conditions, representing the seasonal changes due to lifecycle of riverine plants, were investigated: leafless and foliated. In addition to descriptive data analyses, equations from literature were applied and tested against the flume measurements to check if it was possible to use them for a reliable prediction under the examined vegetative conditions.
The experimental data showed that effects of the presence of vegetation on flow field and fine sediment transport vary when the plant density increases (i.e. changing from leafless to foliated condition). The difference in streamwise velocity between the open channel and the vegetated region increased. SSC decreased, within the foliated vegetation compared to the main channel, in agreement with the decrease in velocity and increase in net deposition. Under foliated condition, the mechanical dispersion appeared to lead sediment transport, because turbulence declined rapidly. In the leafless case, the turbulence at the stem scale was the main player, determining high local fluctuations in transversal and vertical profiles for both SSC and streamwise velocity and a reduction in net deposition. Overall, the investigations on flow-vegetation-sediment processes performed in two different conditions, representing seasonal vegetation changes, showed that theoretical and empirical relationships used to predict patterns of velocity are less suitable for predictions within leafy vegetation, but they still are in good agreement within flows in leafless condition. For SSC patterns, the predictions through equations and assumptions used in unvegetated channel are hard to obtain and unreliable in both vegetative conditions
Mean-Field games with absorption and singular controls
The first part of the work is devoted to mean-field games with absorption, a class
of games that can be viewed as natural limits of symmetric stochastic differential
games with a large number of players who, interacting through a mean-field, leave
the game as soon as their private states hit a given boundary. In most of the literature
on mean-field games, all players stay in the game until the end of the period,
while in many applications, especially in economics and finance, it is natural to have
a mechanism deciding when a player has to leave. Such a mechanism can be modelled
by introducing an absorbing boundary for the state space.
The second part of the thesis, deals with mean-field games of finite-fuel capacity expansion
with singular controls. While singular control problems with finite (and infinite)
fuel find numerous applications in the economic literature and originated from the
engineering literature in the late 60\u2019s, many-player game versions of these problems
have only very recently been introduced. They are a natural extension of the single
agent set-up and allow to model numerous applied situations. In our work in particular,
we make assumptions on the structure of the interaction across players that
are suitable to model the so-called goodwill problem.
Altogether, the original contribution to the mean-field games literature of the
present work is threefold. First, it contributes to the development of mean-field
games with absorption, continuing the work of Campi and Fischer (2018) and considerably
generalizing the original model by relaxing the assumptions and setting
it into a more abstract, infinite-dimensional, framework. Second, it introduces a
new set of tools to deal with mean-field games with singular controls, extending
the well-known connection between singular stochastic control and optimal stopping
to mean-field games. Finally, it also contributes to the numerical literature on
mean-field games, by proposing a numerical scheme to approximate the solutions
of mean-field games with singular controls with a constructive approach.
Overall, this thesis focuses on newly introduced branches of the theory of meanfield
games that display a high potential for economic and financial applications,
contributing to the literature not only by further developing the existing theory but
also by working in directions that make the these models more suitable to application
Biologic effects of oil fly ash.
Epidemiologic studies have demonstrated increased human morbidity and mortality with elevations in the concentration of ambient air particulate matter (PM). Fugitive fly ash from the combustion of oil and residual fuel oil significantly contributes to the ambient air particle burden. Residual oil fly ash (ROFA) is remarkable in the capacity to provoke injury in experimental systems. The unique composition of this emission source particle makes it particularly useful as a surrogate for ambient air PM in studies of biologic effects testing the hypothesis that metals mediate the biologic effects of air pollution particles. A majority of the in vitro and animal model investigations support the postulate that transition metals present in ROFA (especially vanadium) participate in Fenton-like chemical reactions to produce reactive oxygen species. This is associated with tyrosine phosphorylation, nuclear factor kappa B and other transcription factor activation, induction of inflammatory mediator expression, and inflammatory lung injury. It is also evident that vanadium accounts for a significant portion of the biologic activity of ROFA. The extrapolation of this body of investigation on ROFA to the field of ambient air PM is difficult, as particles in numerous environments have such small amounts of vanadium
Aspectos sintácticos y discursivos de la nominalización en un corpus de manuales escolares
El tratamiento de la nominalización desde un punto de vista sintáctico y discursivo revela una serie de características que se deberán tener presentes al analizar las realizaciones de los sintagmas que encabezan en un corpus textual. En primer lugar, es necesario observar la relación que mantiene la nominalización con una cláusula de verbo finito, de la cual hereda la estructura argumental. Sin embargo, con respecto a dicha cláusula se pierden los significados que aporta la flexión verbal, es decir, la modalidad y la temporalidad enunciativas así como el aspecto de la acción. Otro rasgo fundamental que desaparece con la nominalización es el carácter activo o pasivo de la acción en el caso de los verbos transitivos. Esto ha llevado a plantear la no recuperabilidad total de la cláusula que da origen a una nominalización. Desde el punto de vista discursivo, la nominalización deverbal permite al enunciador introducir en su enunciado objetos discursivos que han sido construidos en el discurso anterior (nominalización anafórica intradiscursiva) o bien presentarlos como preconstruidos, como ya dados de antemano. Al mismo tiempo, el enunciador puede o no saturar la estructura argumental del lexema nominalizado, de modo que los papeles temáticos de agente, de paciente, de meta, etc. pueden estar explícitamente integrados en el sintagma como complementos, o bien ser recuperables a partir del contexto, o bien quedar vacíos. La aparición de nominalizaciones preconstruidas en un discurso permite observar la presencia del interdiscurso, en la medida en que el enunciador presenta un enunciado anterior, procedente de otro lugar como un objeto ya dado, de cuya aserción no se hace cargo, pero que despliega la evidencia de lo consabido. A partir de estas consideraciones se analiza un corpus constituido por una serie de manuales escolares de Historia Argentina publicados entre 1980 y 2000, en los que el tratamiento de los gobiernos peronistas adquiere un particular interés dado el grado de conflictividad política que conlleva el tema en la sociedad argentina y, en consecuencia, en la educación pública del ciudadan
Caractéristiques de la dynamique d'un Pneumotachographe pour l'étude de la production de la parole : aspects acoustiques et aérodynamique.
International audienceThe measure of aerodynamic parameters in the study of the articulatory mechanisms of speech production poses many problems. Some of them are not solved today. To measure oral and nasal airflow, a certain number of conditions must be met. In this aim, we designed and built a pneumotachograph with particular care to optimise its response time, linearity and acoustical response. This flow meter is based on the grid flow meter principle with a small dead volume and specific linearisation for the inhaled and exhaled airflow. A soft silicone rubber mask, pressed against the speaker's face prevents air leakage, without hindering articulatory movements. The acoustical distortions of the speech sound through the device are remedied by an adapted signal processing from its transfer function.La mesure de paramètres aérodynamiques dans l'étude des mécanismes articulatoires dans la production de parole pose de nombreux problèmes. Certains d'entre eux ne sont pas définitivement résolus. Pour mesurer le flux d'air oral et nasal, un certain nombre de conditions doivent être réunies. Dans ce but, nous avons réalisé un pneumotachographe conçu avec un soin particulier pour optimiser son temps de réponse, sa linéarité et sa distorsion acoustique. Ce capteur de débit utilise une grille résistive et possède un faible volume mort. Un masque en caoutchouc de silicone mou, appuyé contre le visage du locuteur empêche la fuite d'air, sans gêner les mouvements articulatoires. Les déformations acoustiques engendrées le dispositif sont atténuées par un traitement des signaux adapté de sa fonction de transfert
- …