Aesthetic interaction in the visual arts as a measure against anthropocentric attitudes towards the environment

Published Articl

Sea surface dynamic height topography and the North Equatorial countercurrent as inferred from a linear model

Hellerman and Rosenstein's (1983) climatological winds are used to force a linear, continuously stratified model of the tropical Atlantic. The dynamic height topography relative to 500 meters is compared with available data. Special attention is paid to the computed North Equatorial countercurrent. We conclude that most of the observed seasonal variations can be explained using simple linear theory. (Résumé d'auteur

Higher education in an era of complexity: "The tributaries project" as a higher education heterotopia

Widespread calls to develop modes of teaching and learning in higher education for a paradigm of complexity recognize higher education’s double task; namely, to graduate students not only with technical/theoretical expertise, but also the capacity for responsible citizenship. In this article we offer retrospective, philosophical reflections on a South African university engagement project, “The Tributaries Project” (2019). These reflections aim to show that such academic engagement projects, formed as “higher education heterotopia” (a concept co-opted from a 1967 lecture by Michel Foucault) are favourable sites for the second aspect of higher education’s task; that is, to foster responsible citizenship among university staff, students and graduates in an era of complexity. Further, Edgar Morin’s “seven complex lessons” detail the essential elements of this task, and by extension heterotopic spaces, such as those configured by The Tributaries Project offer ideal conditions for the implementation of Morin’s insights. In Part One, we reflect on key theoretical assumptions underlying “The Tributaries Project”, via the lens of the concept “heterotopia”. Part Two is organised by Edgar Morin’s “seven complex lessons”, with brief indications of how these lessons were implemented via the project’s diverse activities. We hope that sharing insights gained from theorizing, creating and implementing this project may inspire similar projects

Intensive variables in the framework of the non-extensive thermostatistics

By assuming an appropriate energy composition law between two systems governed by the same non-extensive entropy, we revisit the definitions of temperature and pressure, arising from the zeroth principle of thermodynamics, in a manner consistent with the thermostatistics structure of the theory. We show that the definitions of these quantities are sensitive to the composition law of entropy and internal energy governing the system. In this way, we can clarify some questions raised about the possible introduction of intensive variables in the context of non-extensive statistical mechanics.Comment: 14 pages, elsart style, version accepted on Physics Letters

Variation of Impact Toughness of As-Built DMLS Ti6Al4V (ELI) Specimens with Temperature

Published ArticleThe response of direct metal laser sintering (DMLS) produced Ti6Al4V (ELI) to impact was investigated using an instrumented Charpy impact test machine and V-notch specimens. Impact toughness testing was conducted over the temperature range of -130oC to 250oC. The effect of the orientation of the V-notch, with reference to the base plate, was investigated. The results indicated that the samples that were produced with the V-notch facing the base plate (LO) had better values of impact toughness than those that were produced with the V-notch facing away from the base plate (UP) over most of the test temperatures. The study further established that as-built DMLS Ti6Al4V (ELI) retains appreciable notch toughness, even at extremely low temperatures

DYNAMIC BEHAVIOUR OF DIRECT METAL LASER SINTERED TI-6AL-4V (ELI) UNDER HIGH STRAIN RATES IN COMPRESSION LOADING

ArticleDeformation behaviour under dynamic compression of Ti-6Al-4V (ELI) produced through additive manufacturing in two different forms; as-built (AB) and stress relieved (SR), was investigated. Both AB and SR specimens were printed using the DMLS EOSINT M280 system. Compression tests were performed on the specimens at strain rate ranges lying between (300s-1-400s-1) and (600s-1-700s-1) using a Split Hopkinson Pressure Bar. This paper presents Scanning Electron Microscope (SEM) micrographs of the resulting fracture surfaces of the tested specimens, as well as scanned surfaces of through cuts, parallel and perpendicular to the load-direction of specimens that did not fracture, with a focus on the microstructural features peculiar to shear and adiabatic deformation

Mean-field Phase Diagram of Two-Dimensional Electrons with Disorder in a Weak Magnetic Field

We study two-dimensional interacting electrons in a weak perpendicular magnetic field with the filling factor $\nu \gg 1$ and in the presence of a quenched disorder. In the framework of the Hartree-Fock approximation, we obtain the mean-field phase diagram for the partially filled highest Landau level. We find that the CDW state can exist if the Landau level broadening $1/2\tau$ does not exceed the critical value $1/2\tau_{c}=0.038\omega_{H}$. Our analysis of weak crystallization corrections to the mean-field results shows that these corrections are of the order of $(1/\nu)^{2/3}\ll 1$ and therefore can be neglected

Quantitative Behavioural Reasoning for Higher-order Effectful Programs: Applicative Distances (Extended Version)

This paper studies the quantitative refinements of Abramsky's applicative similarity and bisimilarity in the context of a generalisation of Fuzz, a call-by-value $\lambda$-calculus with a linear type system that can express programs sensitivity, enriched with algebraic operations \emph{\`a la} Plotkin and Power. To do so a general, abstract framework for studying behavioural relations taking values over quantales is defined according to Lawvere's analysis of generalised metric spaces. Barr's notion of relator (or lax extension) is then extended to quantale-valued relations adapting and extending results from the field of monoidal topology. Abstract notions of quantale-valued effectful applicative similarity and bisimilarity are then defined and proved to be a compatible generalised metric (in the sense of Lawvere) and pseudometric, respectively, under mild conditions

Periodontitis and cognitive impairment in older adults:The mediating role of mitochondrial dysfunction

Background: Increased attention has been focused on the associations of periodontal disease with the onset and progression of cognitive impairment. Although the associations are likely to be multifactorial, few studies have explored the role of mitochondrial dysfunction in the periodontitis-dementia link. Methods: Cross-sectional data of 1,883 participants aged ≥60 years in the National Health and Nutrition Examination Survey 2011‒2014 were analyzed. The following data were collected: 1) general information on sociodemographic, behavioral, and health-related factors; 2) periodontal status (mean attachment loss [AL] and mean probing depth [PD]); 3) mitochondrion-derived biomarker of mitochondrial dysfunction (blood sample concentration of methylmalonic acid [MMA]); 4) cognitive function (Consortium to Establish a Registry for Alzheimer's disease immediate recall [CERAD-IR] and delay recall [CERAD-DR], animal fluency test, and digit symbol substitution test [DSST]). Mediation analysis weighted for complex survey design was used to assess the effect of MMA on the association of periodontal status with cognitive function after adjusting for potential confounders. Results: Participants with Stage III and IV periodontitis had lower scores on cognitive performance and higher MMA levels than those with Stages I/II periodontitis. Circulating MMA was significantly associated with CERAD-DR (weighted β [SE] = −0.076 [0.011]) and DSST (weighted β [SE] = −0.039 [0.009]), which mediated 9.9% and 6.0% of the total association of mean PD with cognitive function. Moreover, MMA mediated 11.7% and 5.8% of the association of mean AL with CERAD-DR and DSST, respectively. Conclusion: The findings suggest that MMA, a biomarker of mitochondrial dysfunction, plays a mediating role in the link between periodontitis and cognitive impairment in older adults aged ≥60 years

Relativistic graphene ratchet on semidisk Galton board

Using extensive Monte Carlo simulations we study numerically and analytically a photogalvanic effect, or ratchet, of directed electron transport induced by a microwave radiation on a semidisk Galton board of antidots in graphene. A comparison between usual two-dimensional electron gas (2DEG) and electrons in graphene shows that ratchet currents are comparable at very low temperatures. However, a large mean free path in graphene should allow to have a strong ratchet transport at room temperatures. Also in graphene the ratchet transport emerges even for unpolarized radiation. These properties open promising possibilities for room temperature graphene based sensitive photogalvanic detectors of microwave and terahertz radiation.Comment: 4 pages, 4 figures. Research done at Quantware http://www.quantware.ups-tlse.fr/. More detailed analysis is give