Redox reactions in Prussian blue containing paint layers as a result of light exposure

in Journal of Analytical Atomic Spectrometry [=JAAS] (2013)

Prussian blue, a mixed valence pigment, typically KFeIII[FeII(CN)6].xH2O, was the most widely used blue artistic pigment from ca. 1720 to the 1970's but, unfortunately, its paint layers, especially when ... [more ▼]

Prussian blue, a mixed valence pigment, typically KFeIII[FeII(CN)6].xH2O, was the most widely used blue artistic pigment from ca. 1720 to the 1970's but, unfortunately, its paint layers, especially when used in conjunction with a white pigment, tend to fade or turn green upon extended exposure to light. In order to identify the mechanism underlying these changes, paint layers have been prepared with differing amounts of these white pigments and subjected to accelerated light exposure fading. The resulting unfaded and faded paint layers as well as both the Berlin white pigment, Fe2II[FeII(CN)6], and the partially oxidized Berlin green pigment, {KFeIII[FeII(CN)6]}x{FeIII[FeIII(CN)6]}1–x, have been characterized by Raman and iron-57 Mössbauer spectroscopy. The results indicate that, upon fading, the Prussian blue pigment painted with a linseed oil binder and (PbCO3)2Pb(OH)2 or ZnO, and to a lesser extent with TiO2, undergoes a reduction at the exposed paint surface and an oxidation in the bulk of the paint layer. This combined reduction and oxidation disrupts, at least in part, the FeIII–N–C–FeII intervalent electron transfer pathways in Prussian blue thus leading to pigment fading through a reduction in the intervalent electron transfer absorbance at about 700 nm. [less ▲]

Concern-induced negative affect is associated with the occurrence and content of mind-wandering

in Consciousness & Cognition (2013), 22(2), 442-448

Previous research has shown that the content and frequency of mind-wandering episodes—the occurrence of thoughts that are both stimulus-independent and task-unrelated—are closely related to an ... [more ▼]

Previous research has shown that the content and frequency of mind-wandering episodes—the occurrence of thoughts that are both stimulus-independent and task-unrelated—are closely related to an individual’s future-related concerns. Whether this relationship is shaped by the affective changes that are usually associated with future-related concerns still remains unclear, however. In this study, we induced the anticipation of a negatively valenced event and examined whether the ensuing affective changes were related to the occurrence and content of mind-wandering during an unrelated attentional task. We found that the increase in negative affect following concern induction predicted the general frequency of mind-wandering episodes. Furthermore, mind-wandering episodes specifically directed at the induced concern were related to a lower decrease in negative affect during the attentional task. These results suggest that the negative emotional impact of future-related concerns is an important factor to be taken into consideration for the subsequent occurrence of mind-wandering episodes, which might in turn be involved in the maintenance of negative affect over time. [less ▲]

Sensitivity to tactile novelty in the terrestrial isopod, Porcellio scaber

in Behavioural Processes (2013), 92(1), 52-59

Invertebrates have been studied at biochemical, ecological, and behavioural levels, but current knowledge about the impact that learning may have on behaviour is rather sparse. The present study aimed to ... [more ▼]

Invertebrates have been studied at biochemical, ecological, and behavioural levels, but current knowledge about the impact that learning may have on behaviour is rather sparse. The present study aimed to examine the sensitivity of isolated rough woodlice (Porcellio scaber Latreille 1804) to the tactile novelty of their environment. A simple way to test this issue was to refer to the place preference paradigm, traditionally used in vertebrates. In Experiment 1, woodlice were placed in a compartment for 30 min in order to assess their ability to develop habituation in the absence of reward. In Experiment 2, woodlice were exposed to a compartment for 20 min (habituation phase) and were then given free choice between that compartment and a novel compartment for 2 min (preference phase). Depending on test conditions, rewards (humidity and/or shelter) were present or absent in the familiar compartment. The familiar and novel compartments differed with respect to the texture of the floor. In Experiment 3, the floor texture was the same in the two compartments in order to control for a novelty effect. The main results indicate that woodlice exhibited increased locomotion time, increased distance travelled, and increased speed in the novel compartment compared to the familiar compartment. There was no preference for either compartment when the floor textures of both were identical. [less ▲]

Benevolent sexism, Men's adventages and the prescription of warmth to women

in Sex Roles (2013), 68

La loi "Salduz" confirmée et améliorée par la Cour constitutionnelle

in Revue de Jurisprudence de Liège, Mons et Bruxelles (2013)

Présentation de l'arrêt de la Cour constitutionnelle n° 7/2013 du 14 février 2013 relatif à la présence de l'avocat aux côtés du suspect dès son premier interrogatoire en application de la jurisprudence ... [more ▼]

Présentation de l'arrêt de la Cour constitutionnelle n° 7/2013 du 14 février 2013 relatif à la présence de l'avocat aux côtés du suspect dès son premier interrogatoire en application de la jurisprudence "Salduz" ; mise en exergue des dispositions annulées, d'une part, et interprétées d'une manière particulière par la Cour constitutionnelle, d'autre part, et réflexions critiques. [less ▲]

A prospective study of cardiac valvular status in patients treated with cabergoline for endocrine disease

in Symposium "Perspectives in Endocrinology" - Congresses Highlights 2012: ECE Firenze, ENDO Houston, ESPE Leipzig, SFE Toulouse, IWMEN Liège (2013)

Malabsorption des hormones thyroïdiennes... ou simple manque de compliance ?

in Revue Médicale de Liège (2013), 68(3), 118-121

A Thermomechanical Model Dedicated to Thixoforming. Application to Semi-Solid Forming

in Solid State Phenomena (2013), 192-193

This paper deals with the simulation of two extrusion tests by thixoforming: a non stationary extrusion test and a double-cup extrusion test. The simulations are based on a thermo-mechanical one-phase ... [more ▼]

This paper deals with the simulation of two extrusion tests by thixoforming: a non stationary extrusion test and a double-cup extrusion test. The simulations are based on a thermo-mechanical one-phase constitutive law that has been presented in details in previous papers. A campaign of experimental extrusion testing has been conducted on a steel alloy and the comparison between the numerical and experimental results will validate the model under study. A new feature that has been added to the model is also discussed: the introduction of the phase change thermal effects such as the fusion latent heat and the contraction of the material [less ▲]

Left ventricular contractile reserve in asymptomatic primary mitral regurgitation

in European Heart Journal (2013)

Outcome and impact of surgery in paradoxical low flow low gradient severe aortic stenosis and preserved left ventricular ejection fraction: a cardiac catheterization study

in Circulation (2013)