Geometry-induced phase transition in fluids: capillary prewetting

We report a new first-order phase transition preceding capillary condensation and corresponding to the discontinuous formation of a curved liquid meniscus. Using a mean-field microscopic approach based on the density functional theory we compute the complete phase diagram of a prototypical two-dimensional system exhibiting capillary condensation, namely that of a fluid with long-ranged dispersion intermolecular forces which is spatially confined by a substrate forming a semi-infinite rectangular pore exerting long-ranged dispersion forces on the fluid. In the T-mu plane the phase line of the new transition is tangential to the capillary condensation line at the capillary wetting temperature, Tcw. The surface phase behavior of the system maps to planar wetting with the phase line of the new transition, termed capillary prewetting, mapping to the planar prewetting line. If capillary condensation is approached isothermally with T>Tcw, the meniscus forms at the capping wall and unbinds continuously, making capillary condensation a second-order phenomenon. We compute the corresponding critical exponent for the divergence of adsorption.Comment: 5 pages, 4 figures, 5 movie

Direct synthesis and morphological characterization of gold-dendrimer nanocomposites prepared using PAMAM succinamic acid dendrimers : preliminary study of the calcification potential

Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach based on the use of polyamidoamine dendrimers with succinamic acid terminal groups and dodecanediamine core. Spherical and highly crystalline nanoparticles with dimensions between 3 nm and 60 nm, and size-polydispersity depending on the synthesis conditions, have been generated. The influence of the stoichiometric ratio and the structural and architectural features of the dendrimers on the properties of the nanocomposites has been described. The self-assembling behaviour of these materials produces gold-dendrimer nanostructured porous networks with variable density, porosity, and composition. The investigations of the reaction systems, by TEM, at two postsynthesis moments, allowed to preliminary establish the control over the properties of the nanocomposite products. Furthermore, this study allowed better understanding of the mechanism of nanocomposite generation. Impressively, in the early stages of the synthesis, the organization of gold inside the dendrimer molecules has been evidenced by micrographs. Growth and ripening mechanisms further lead to nanoparticles with typical characteristics. The potential of such nanocomposite particles to induce calcification when coating a polymer substrate was also investigated

The Infertility-Related Stress Scale: Validation of a Brazilian–Portuguese Version and Measurement Invariance Across Brazil and Italy

Infertility constitutes an essential source of stress in the individual and couple's life. The Infertility-Related Stress Scale (IRSS) is of clinical interest for exploring infertility-related stress affecting the intrapersonal and interpersonal domains of infertile individuals' lives. In the present study, the IRSS was translated into Brazilian-Portuguese, and its factor structure, reliability, and relations to sociodemographic and infertility-related characteristics and depression were examined. A sample of 553 Brazilian infertile individuals (54.2% female, mean aged 36 ± 6 years) completed the Brazilian-Portuguese IRSS (IRSS-BP), and a subsample of 222 participants also completed the BDI-II. A sample of 526 Italian infertile individuals (54.2% female, mean aged 38 ± 6 years) was used to test for the IRSS measurement invariance across Brazil and Italy. Results of exploratory structural equation modeling (ESEM) indicated that a bifactor solution best represented the structure underlying the IRSS-BP. Both the general and the two specific intrapersonal and interpersonal IRSS-BP factors showed satisfactory levels of composite reliability. The bifactor ESEM solution replicated well across countries. As evidence of relations to other variables, female gender, a longer duration of infertility, and higher depression were associated with higher scores in global and domain-specific infertility-related stress. The findings offer initial evidence of validity and reliability of the IRSS-BP, which could be used by fertility clinic staff to rapidly identify patients who need support to deal with the stressful impact of infertility in the intrapersonal and interpersonal life domains, as recommended by international guidelines for routine psychosocial care in infertility settings

Generalized dynamical density functional theory for classical fluids and the significance of inertia and hydrodynamic interactions

We study the dynamics of a colloidal fluid including inertia and hydrodynamic interactions, two effects which strongly influence the non-equilibrium properties of the system. We derive a general dynamical density functional theory (DDFT) which shows very good agreement with full Langevin dynamics. In suitable limits, we recover existing DDFTs and a Navier-Stokes-like equation with additional non-local terms.Comment: 5 pages, 4 figures, 4 supplementary movie files, I supplementary pd

Composição corporal de frangos de corte alimentados com dietas fareladas e peletizadas contendo milheto grão ou moído

Projeto/Plano de Ação: 16.00.30.00

Investigation on different materials after pulsed high field conditioning and low-energy H- irradiation

During operation, the radio-frequency quadrupole (RFQ) of the LINAC4 at CERN is exposed to high electric fields, which can lead to vacuum breakdown. It is also subject to beam loss, which can cause surface modification, including blistering, which can result in reduced electric field holding and an increased breakdown rate. First, experiments to study the high-voltage conditioning process and electrical breakdown statistics have been conducted using pulsed high-voltage DC systems in order to identify materials with high electric field handling capability and robustness to low-energy irradiation. In this paper, we discuss the results obtained for the different materials tested. To complement these, an investigation of their metallurgical properties using advanced microscopic techniques was done to observe and characterize the different materials and to compare results before and after irradiation and breakdown testing

The influence of the Evros River on the recent sedimentation of the inner shelf of the NE Aegean Sea

Abstract The transboundary Evros River discharges into the Alexandroupolis Gulf, located in the inner shelf of the northeastern Aegean Sea, where it has formed an extended delta. Grain-size and mineralogical analyses of five sediment cores, collected in the subaqueous delta, provide the following information about recent sedimentation processes in the northeastern part of the Aegean shelf: (a) river mouth deposits, consisting of coarse-grained sediments, are mainly deposited in front of the active mouth, whilst some sandy material is expected to be transported alongshore by nearshore currents; (b) delta front deposits are characterised by fine-grained sediments that include evidence of human activities which have taken place, in a more intense way, since the 1950s; and (c) prodelta deposits are represented by almost uniform riverine mud that cover the pre-existed relict sands of the shelf, indicating also the limit (some 15 km to the SW) of the influence of riverine sedimentation on the seabed of the inner shelf of the Alexandroupolis Gulf

A view of the M81 galaxy group via the H-alpha window

We present images for 36 galaxies of the M81 group obtained in the H-alpha line. Estimates of the H-alpha flux and star formation rate, SFR, are avialable now for all the known members of the group with absolute magnitudes down to M_B = -10^m. The character of distribution of the galaxies over three paremeters: M_B, SFR, and total hydrogen mass permits us to draw the following conclusions as to evolution status of the group population. a) Spiral and irregular type galaxies would have time to generate their luminosity (baryon mass) during the cosmological time T_0=13.7 Gyr, but dwarf spheroidal objects are capable of reproducing only ~5% of their observed luminosity. b) S and Im, BCD galaxies possess the supply of gas sufficient to maintain their observed SFRs during only next (1/4 -1/3)T_0 years, while dIr and dSph populations have the mean gas depletion time about 3 T_0. c) There is indirect evidence that the star formation in Im, BCD and dIr galaxies proceeds in a mode of vigorous burst activity rather than in the form of a sluggish process. We note the dwarf tidal system near NGC 3077, the Garland, to have the highest SFR per unit luminosity among 150 galaxies of the Local volume with known SFRs. Being averaged over the local "cell of homogeneity" of 4 Mpc in diameter around M 81, the rate of star formation of the group, rho(SFR)= 0.165 M_sun/year*Mpc^3, proves to be 5-8 times higher than, that of the average global rate at Z =0.Comment: 10 pages, 4 figure (figure 1 is available at http://luna.sao.ru/halpha/articles/M81). Astronomical Journal, accepte

Características da carcaça de frangos alimentados com dietas fareladas e peletizadas contendo milheto grão e moído.

Projeto/Plano de Ação: 16.00.30.00