Connection between slow and fast dynamics of molecular liquids around the glass transition

The mean-square displacement (MSD) was measured by neutron scattering at various temperatures and pressures for a number of molecular glass-forming liquids. The MSD is invariant along the glass-transition line at the pressure studied, thus establishing an ``intrinsic'' Lindemann criterion for any given liquid. A one-to-one connection between the MSD's temperature dependence and the liquid's fragility is found when the MSD is evaluated on a time scale of approximately 4 nanoseconds, but does not hold when the MSD is evaluated at shorter times. The findings are discussed in terms of the elastic model and the role of relaxations, and the correlations between slow and fast dynamics are addressed.Comment: accepted by Phys Rev E (2010

EMOGA: a hybrid genetic algorithm with extremal optimization core for multiobjective disassembly line balancing

In a world where products get obsolescent ever more quickly, discarded devices produce million tons of electronic waste. Improving how end-of-life products are dismantled helps reduce this waste, as resources are conserved and fed back into the supply chain, thereby promoting reuse and recycling. This paper presents the Extremal MultiObjective Genetic Algorithm (EMOGA), a hybrid nature-inspired optimization technique for a multiobjective version of the Disassembly Line Balancing Problem (DLBP). The aim is to minimize the number of workstations, and to maximize profit and disassembly depth, when dismounting products in disassembly lines. EMOGA is a Pareto-based genetic algorithm (GA) hybridized with a module based on extremal optimization (EO), which uses a tailored mutation operator and a continuous relaxation-based seeding technique. The experiments involved the disassembly of a hammer drill and a microwave oven. Performance evaluation was carried out by comparing EMOGA to various efficient algorithms. The results showed that EMOGA is faster or gets closer to the Pareto front, or both, in all comparisons

The consequence of excess configurational entropy on fragility: the case of a polymer/oligomer blend

By taking advantage of the molecular weight dependence of the glass transition of polymers and their ability to form perfectly miscible blends, we propose a way to modify the fragility of a system, from fragile to strong, keeping the same glass properties, i.e. vibrational density of states, mean-square displacement and local structure. Both slow and fast dynamics are investigated by calorimetry and neutron scattering in an athermal polystyrene/oligomer blend, and compared to those of a pure 17-mer polystyrene considered to be a reference, of same Tg. Whereas the blend and the pure 17-mer have the same heat capacity in the glass and in the liquid, their fragilities differ strongly. This difference in fragility is related to an extra configurational entropy created by the mixing process and acting at a scale much larger than the interchain distance, without affecting the fast dynamics and the structure of the glass

Tendances pluviométriques et impact de la marée sur le drainage en zone d’estuaire : cas du Wouri au Cameroun

L’estuaire du Wouri, ouverte sur l’océan Atlantique fait du Cameroun une zone d’intérêt stratégique. Cependant, l’exploitation de cet avantage se trouve limitée par des inondations récurrentes dont les causes sont d’ordre hydrométéorologique et social. L’assainissement urbain par le drainage pluvial s’avère ici inefficace du fait du battement de la marée; les informations chiffrées sur l’influence de la marée demeurant insuffisantes pour prévenir les débordements. Cet article apporte une contribution à la prévision des inondations localisées à travers une analyse du comportement hydrodynamique du fleuve Wouri à son littoral. Les variations de la pluviométrie, les fluctuations de l’onde-marée, et les battements de la nappe phréatique sont ainsi étudiées pour apprécier la contribution de ces paramètres à la résurgence des inondations. Les précipitations de la zone de l’estuaire sont globalement supérieures à 3500 mm/an avec des pointes en Juillet et Août. La fluctuation de la marée génère un flux d’eau de 222,8 km3/jour vers le continent, induisant une remontée rapide des eaux de la nappe phréatique dans un sol fortement perméable de par sa structure sableuse. Cette situation est exacerbée par les pratiques de gestion des déchets et de l’habitat. La planification urbaine devrait donc prendre en compte à la fois les réalités sociales, les projections économiques et les contraintes hydrologiques, tout autant que les risques d’inondation dans les zones d’estuaire.Mots-clés: inondation, hydrologie, planification urbaine, assainissement. Rainfall trends and tide impact on drainage in estuary areas : Wouri case study in Cameroon The Wouri estuary, open to the Atlantic Ocean is a strategic area of Cameroon. However, the exploitation of this advantage is limited by recurrent flooding whose causes are of hydro-meteorological and social order. The approach of the storm drainage developed so far is then ineffective due to the tide beat. However, the figures on the influence of the tide are still insufficient to prevent overflows. This article contributes to the prediction of localized flooding through analysis of the hydrodynamic behavior of the Wouri River to its coastline. Changes in rainfall, fluctuations of the wave-tide and the watertable beat are studied to assess the contribution of these parameters to the resurgence of flooding. Rainfall within the estuary is generally larger than 3500 mm/year with peaks in July and August. The fluctuation of water level due to tide generates 222.8 km3/day to the continent induces rapid upwelling of groundwater in a permeable soil because of its sandy structure. A situation worsened by waste management and settlement practices. Urban planning should then take into consideration social realities, economic projections, hydrological constraints as well as flood risk in estuary zones.Keywords: flood, hydrology, urban planning, sanitation

The illness trajectory in Marilyn Monroe‘s psychological autopsy: from autism spectrum disorder to borderline personality disorder and bipolar disorder with catatonia

Objective: A mounting body of literature is showing that, in the clinical and general population, autism spectrum disorder (ASD) or autistic traits (ATs) would appear to be spread along a continuum, reaching the highest levels among individuals affected by other mental disorders, such as borderline personality disorder (BPD) and bipolar disorder (BD). Furthermore, individuals with ASD or ATs appear to be more vulnerable to psychological traumas, with greater likelihood of developing post-traumatic stress disorder (PTSD) and BD. Marilyn Monroe was a famous actress, singer and model, as well as one of the most admired stars of American cinema and a timeless icon. The present report debates the possibility to explore Marilyn Monroe’s case under a neurodevelopmental perspective according to which a ASD favored, on one hand, her worldwide success and, on the other, her mental illness trajectory. Method: The analysis is based on the review of her four biographies written by psychiatrists and clinical psychologists, her complete filmography, interviews, filmed material and personal scripts. Results: The present work reconstructed a hypothetical illness trajectory originating from a ASD and culminating in a BD with unspecified catatonia, followed by premature death whose cause has never been clarified. The description of this illness trajectory also confirms the strong impact of psychological traumas on the substrate of ASD vulnerability and its correlation with the development of BPD and BD. Conclusions: This paper suggests Marilyn Monroe as a possible prototypical case of BPD under a neurodevelopmental perspective that accounts the ASD, as reported in DSM-5-TR (2022), in verbal adult without intellectual impairment, high-functioning autism (HFA), as vulnerability background predisposing to the progression to BPD and BD with unspecified catatonia, triggered by multiple traumas

On the correlation between fragility and stretching in glassforming liquids

We study the pressure and temperature dependences of the dielectric relaxation of two molecular glassforming liquids, dibutyl phtalate and m-toluidine. We focus on two characteristics of the slowing down of relaxation, the fragility associated with the temperature dependence and the stretching characterizing the relaxation function. We combine our data with data from the literature to revisit the proposed correlation between these two quantities. We do this in light of constraints that we suggest to put on the search for empirical correlations among properties of glassformers. In particular, argue that a meaningful correlation is to be looked for between stretching and isochoric fragility, as both seem to be constant under isochronic conditions and thereby reflect the intrinsic effect of temperature

Quantifying the extent of plant functional specialization using Grime's CSR strategies

Specialization refers to a species adaptation to a restricted range of environmental conditions. While generalist species are able to exploit a wide variety of resources in a broad range of habitats, specialist species tend to have narrower niche breadths. From an evolutionary perspective, specialization is the result of a functional syndrome in which a suite of traits covary to allow the effective exploitation of specific resources. Accordingly, the measurement of specialization should be based on a multi-trait approach. In plant ecology, a well-known classification of the adaptive strategies of plants is Grime's competitor, stress tolerator, ruderal (CSR) theory in which the three principal strategies represent relatively easily measurable trait combinations from the global spectrum of plant form and function arising under conditions of competition, abiotic restriction to growth or periodic disturbance, respectively. In this paper, we thus introduce a method to summarize the functional specialization of plant species and communities by applying inequality measures to Grime's CSR strategies. The general idea is that a plant species that can be exclusively assigned to one CSR strategy can be considered a specialist (as it adopts only one adaptive strategy to access resources), while species that share functional characteristics of multiple CSR strategies can be considered more generalist. The behavior of the proposed measures is shown with one case study on the functional changes of six Alpine vegetation types ordered along a gradient, from pioneer to more stable communities

Sensory branding and buying behavior in coffee shops : a study on Generation Y

With the rise of globalisation and the infiltration of global brands into emerging markets, retailers are facing challenges to win market share in this competitive landscape. As a result, retailers are reverting to innovative methods such as experiential marketing to influence consumer buying behaviour. The purpose of this paper is to investigate the effectiveness of using experiential marketing as a way of influencing consumers’ purchase intentions in coffee shops. The influences of scent and sight as predictors of purchase intention among Generation Y consumers is explored. By means of a quantitative study, 256 self-administered questionnaires were distributed amongst Generation Y individuals in Johannesburg. The data analysis was done by means of structural equation modelling (SEM), with the main focus being placed on path modelling for testing the proposed hypotheses. The findings indicate that both scent and sight are predictors of purchase intention. Although several studies have explored this phenomenon in an array of contexts, few studies have investigated Generation Y within a South African context. This paper is of paramount importance to retailers who seek to gain market share in the competitive landscape by implementing innovative ways in a bid to effectively influence consumer buying behaviour

Development of a Novel Snom Probe for in Liquid Biological Samples

This work is focused on the study and implementation of a novel method for the development of probes for Scanning Near-field Optical Microscopy (SNOM). The proposed approach is based on the mechanical impedance matching between the optical fiber tip and the resonating tuning fork. This methodology allowed an increase of the quality factor of the piezoelectric resonator used as atomic force transducer in the SNOM probe, thus increasing its overall sensitivity. This kind of probes are often used on biological soft samples in liquid. The presence of water medium has a strong dumping effect on probe sensitivity. Experimental validation of the proposed methodology showed an increase of robustness of SNOM probes also for in liquid samples

Information-theoretic sensitivity analysis: a general method for credit assignment in complex networks

Most systems can be represented as networks that couple a series of nodes to each other via one or more edges, with typically unknown equations governing their quantitative behaviour. A major question then pertains to the importance of each of the elements that act as system inputs in determining the output(s). We show that any such system can be treated as a ‘communication channel’ for which the associations between inputs and outputs can be quantified via a decomposition of their mutual information into different components characterizing the main effect of individual inputs and their interactions. Unlike variance-based approaches, our novel methodology can easily accommodate correlated inputs