Strain induced abnormal grain growth in nickel base superalloys

International audienceUnder certain circumstances abnormal grain growth occurs in Nickel base superalloys during thermomechanical forming. Second phase particles are involved in the phenomenon, since they obviously do not hinder the motion of some boundaries, but the key parameter is here the stored energy difference between adjacent grains. It induces an additional driving force for grain boundary migration that may be large enough to overcome the Zener pinning pressure. In addition, the abnormal grains have a high density of twins, which is likely due to the increased growth rate

Ag-Vanadates/GO Nanocomposites by Aerosol-Assisted Spray Pyrolysis: Preparation and Structural and Electrochemical Characterization of a Versatile Material

In this article, we describe the deposition by aerosol-assisted spray pyrolysis of different types of silver vanadate nanocomposites with and without graphene oxide (GO) on different substrates (carbon paper (CP) and fluorine-doped tin oxide (FTO)). When deposited on CP, different amounts of GO were added to the Ag and V precursor solution to study the effect of GO on the physicochemical properties of the resulting Ag-vanadate. It is shown that the addition of GO leads mainly to the formation of nanoparticles of the Ag2V4O11 phase, whereas Ag2V4O11 and Ag3VO4 are obtained without the addition of GO. The morphology and chemical properties of the composites were determined by scanning and transmission electron microscopies, X-ray diffraction, X-ray photoemission spectroscopy, and UV\u2013visible and Raman spectroscopies. In addition, the photoelectrochemical (PEC) properties of such composites were studied by CV, linear sweep voltammetry, and electrochemical impedance spectroscopy. The ideal AgxVOy and GO ratio was optimized for obtaining higher photocurrent values and a good stability. The results showed that the presence of GO improves the electrical conductivity of the catalyst layer as well as the electron injection from the oxide to the electrode surface. The deposition of pure Ag2V4O11 on FTO does not lead to samples with stable PEC performances. Samples grown on CP supports showed an efficient electrochemical detection of small amounts of ethylenediamine in water solution

Understanding and modeling of gain boundary pinning in Inconel718

International audienceThe microstructure stability during d sub-solvus annealing was investigated in Inconel 718 alloy. A reference dynamically recrystallized microstructure was produced through thermomechanical processing (torsion). The reference microstructure evolution during annealing was analyzed by EBSD (grain size, intragranular misorientation) and SEM ( phase particles). Results con rm that, in the absence of stored energy, the grain structure is controlled by the phase particles, as predicted by the Zener equation. If the reference microstructure is strained (e < 0:1) before annealing, then stored energy gradients between grains will induce selective grain growth leading to coarsening. The phenomenon is controlled by the balance of three forces (acting on boundaries migration) having the same order of magnitude: capillarity, stored-energy and pinning forces. All these forces could be modeled in a single framework by the level set method. The rst numerical results demonstrate the capability of the method to simulate 2D Zener pinning. The aim of this paper is to investigate the influence of the distribution of d phase particles and deformation stored energyon the microstructure stability during d sub-solvus annealing

Multimodal hybrid 2D networks via the thiol-epoxide reaction on 1T/2H MoS2 polytypes

The study adds a fundamental tile to the still incomplete puzzle of covalent functionalization tools of 2D inorganic networks and describes a protocol where organic moieties are covalently grafted at both phases (1T and 2H) of a CE-MoS2 sample

Intestinal antispasmodic effects of three Argentinian plants: <i>Hypericum connatum</i>, <i>Berberis ruscifolia</i> and <i>Cecropia pachystachya</i>: mechanisms of action and comparison with the effects of <i>Brugmansia arborea</i>

Some medicinal plants are used in Argentina to reduce gastrointestinal symptoms as antispasmodics, but notall these effects were validated. This work studied the effects of three native plants as the ethanolic tinctures(T) of Hypericum connatum and Berberis ruscifolia, as well as the acqueous crude extracts (A.c.e) of Cecropiapachystachya, and compared the mechanisms with those of the peruvian plant Brugmansia arborea inisolated rat intestines. The first three plants demonstrated to have antispasmodic effect mainly due to thenon-competitive blockade of the agonist-induced contraction and calcium influx to the smooth muscle,which was associated to the presence of flavonoids. H. connatum also induced the release of prostaglandinswhich cause intestinal contraction, and NO which cause peristalsis, in a way that the blockade of bothmechanisms potentiated the relaxant effect of the T-H.c. In contrast, the A.c.e of Brugmansia arboreashowed to be a competitive antagonist of muscarinic receptors in the isolated intestine, in agreement withthe presence of tropane alkaloids. Moreover, H. connatum and C. pachystachya also produced certainsedation, which could contribute to the antispasmodic effect. The tincture of Hypericum connatum, but notthat of Berberis ruscifolia, reduced the spontaneous locomotion and exploration of mice in the open-fieldtest, at doses of 200 mg leaves/Kg. Results suggest that the three native plants exhibited an importantantispasmodic effect mainly due to non-competitive antagonism of the agonist and of Ca2+-influx to smoothmuscle.Facultad de Ciencias Exacta

Intestinal antispasmodic effects of three Argentinian plants: <i>Hypericum connatum</i>, <i>Berberis ruscifolia</i> and <i>Cecropia pachystachya</i>: mechanisms of action and comparison with the effects of <i>Brugmansia arborea</i>

Some medicinal plants are used in Argentina to reduce gastrointestinal symptoms as antispasmodics, but notall these effects were validated. This work studied the effects of three native plants as the ethanolic tinctures(T) of Hypericum connatum and Berberis ruscifolia, as well as the acqueous crude extracts (A.c.e) of Cecropiapachystachya, and compared the mechanisms with those of the peruvian plant Brugmansia arborea inisolated rat intestines. The first three plants demonstrated to have antispasmodic effect mainly due to thenon-competitive blockade of the agonist-induced contraction and calcium influx to the smooth muscle,which was associated to the presence of flavonoids. H. connatum also induced the release of prostaglandinswhich cause intestinal contraction, and NO which cause peristalsis, in a way that the blockade of bothmechanisms potentiated the relaxant effect of the T-H.c. In contrast, the A.c.e of Brugmansia arboreashowed to be a competitive antagonist of muscarinic receptors in the isolated intestine, in agreement withthe presence of tropane alkaloids. Moreover, H. connatum and C. pachystachya also produced certainsedation, which could contribute to the antispasmodic effect. The tincture of Hypericum connatum, but notthat of Berberis ruscifolia, reduced the spontaneous locomotion and exploration of mice in the open-fieldtest, at doses of 200 mg leaves/Kg. Results suggest that the three native plants exhibited an importantantispasmodic effect mainly due to non-competitive antagonism of the agonist and of Ca2+-influx to smoothmuscle.Facultad de Ciencias Exacta

Documento finale del Gruppo di lavoro sulle biblioteche pubbliche statali della Direzione Generale Biblioteche e Istituti Culturali del Ministero dei beni e delle attività culturali e del turismo (MIBACT), approvato dal Consiglio Superiore dei Beni Culturali e Paesaggistici il 13 novembre 2017.

The document analyzes the critical issues that inform the Italian State Public Library System, and identifies the priorities for intervention and the consequent actions to perform. It was approved by the Superior Council of the Italian Ministry of Cultural and Natural Heritage on November 13th, 2017 (http://www.beniculturali.it/mibac/multimedia/MiBAC/documents/1519211234845_Resoconto_CSBCP_13_novembre_2017.pdf)

Intestinal antispasmodic effects of three Argentinian plants: <i>Hypericum connatum</i>, <i>Berberis ruscifolia</i> and <i>Cecropia pachystachya</i>: mechanisms of action and comparison with the effects of <i>Brugmansia arborea</i>

Some medicinal plants are used in Argentina to reduce gastrointestinal symptoms as antispasmodics, but notall these effects were validated. This work studied the effects of three native plants as the ethanolic tinctures(T) of Hypericum connatum and Berberis ruscifolia, as well as the acqueous crude extracts (A.c.e) of Cecropiapachystachya, and compared the mechanisms with those of the peruvian plant Brugmansia arborea inisolated rat intestines. The first three plants demonstrated to have antispasmodic effect mainly due to thenon-competitive blockade of the agonist-induced contraction and calcium influx to the smooth muscle,which was associated to the presence of flavonoids. H. connatum also induced the release of prostaglandinswhich cause intestinal contraction, and NO which cause peristalsis, in a way that the blockade of bothmechanisms potentiated the relaxant effect of the T-H.c. In contrast, the A.c.e of Brugmansia arboreashowed to be a competitive antagonist of muscarinic receptors in the isolated intestine, in agreement withthe presence of tropane alkaloids. Moreover, H. connatum and C. pachystachya also produced certainsedation, which could contribute to the antispasmodic effect. The tincture of Hypericum connatum, but notthat of Berberis ruscifolia, reduced the spontaneous locomotion and exploration of mice in the open-fieldtest, at doses of 200 mg leaves/Kg. Results suggest that the three native plants exhibited an importantantispasmodic effect mainly due to non-competitive antagonism of the agonist and of Ca2+-influx to smoothmuscle.Facultad de Ciencias Exacta

Oral Health Survey in Burundi; Evaluation of the Caries Experience in Schoolchildren Using the DMFT Index.

Background and objectives: There are no data on oral health in the population of Burundi. This study aimed to describe the oral health status of schoolchildren in Burundi using the dmft/DMFT index for the first time. Materials and methods: The study was designed as a cross-sectional population-based epidemiological survey. The survey was designed according to the WHO methodology for oral health surveys. Oral examinations were conducted in school rooms using a dental mirror, probe, and headlight. The following characteristics of primary dentition status were recorded: decayed (d/D), missing (m/M), and filled (f/F) teeth, and the dmft/DMFT (d + m + f t/D + M + F T) index was calculated for each subject. Quantitative and qualitative variables were represented by measures of position and variability. One-way ANOVA was used to assess differences between parametric variables. Logistic regression was performed for total caries experience and gender, age groups, living area, and geographical provinces. Results: A total of 1902 children were examined, 1007 (52.94%) six-year-olds and 895 (47.06%) in the older group. The dmft/DMFT and subgroups were statistically significantly different in terms of age groups, living areas, and geographical regions (dmft/DMFT d-subgroup and D-subgroup p < 0.01), but only for DMFT for sex. The ORs estimated by logistic regression by total caries experience showed a protective effect for 12 year old subjects and those living in southern provinces, an OR of 0.52 (95%CI 0.43-0.64) and an OR of 0.26 (95%CI 0.21-0.32), respectively. Conclusions: Dental caries in African countries, including Burundi, remains a major problem affecting the general health and wellbeing of the population. Tackling untreated caries requires a multifaceted approach, including strengthening oral health infrastructure, promoting oral health education, providing affordable dental services, and encouraging healthier eating habits