Electrical resistivity of the Ti4O7 Magneli phase under high pressure

We have measured resistivity as a function of temperature and pressure of Ti4O7 twinned crystals using different contact configurations. Pressures over 4kbar depress the localization of bipolarons and allow the study of the electrical conduction of the bipolaronic phase down to low temperatures. For pressures P > 40 kbar the bipolaron formation transition is suppressed and a nearly pressure independent behavior is obtained for the resistivity. We observed an anisotropic conduction. When current is injected parallel to the principal axis, a metallic conduction with interacting carrier effects is predominant. A superconducting state was not obtained down to 1.2 K, although evidences of the proximity of a quantum critical point were noticed. While when current is injected non-parallel to the crystal's principal axis, we obtained a logarithmic divergence of the resistivity at low temperatures. For this case, our results for the high pressure regime can be interpreted in the framework of interacting carriers (polarons or bipolarons) scattered by Two Level Systems.Comment: 9 Revtex pages, 12 EPS figures included, submitted to The European Physical Journal B. Contact author: C. Acha (e-mail address: [email protected]

Development of alginate beads for probiotic encapsulation: influence of different parameters in the beads size

In the present study different parameters were evaluated in the formation of alginate beads by ionotropic gelation (external extrusion). The size of alginate beads was determined and results showed that needle-CaCl2 solution distance, flow rate, sodium alginate concentration, needle diameter and molecular weight of sodium alginate influenced alginate beads formation. Moreover, was concluded that needle diameter was the parameter that most influenced the beads mean size

New residential uses in rural areas of Castilla y Leon

Resume

Effect of alginate molecular weight and M/G ratio in beads properties foreseeing the protection of probiotics

"Available online 1 December 2017"Probiotics are live microorganisms that when administered in adequate amounts confer a health benefit to the host. However, to accomplish this positive influence on Human health, probiotics should survive to the passage through the upper digestive tract in large numbers to unsure a desired beneficial effect in the host. Several encapsulation methods have been used to protect probiotics. Alginate is the most used biopolymer in the production of these systems, although its performance is totally dependent of its structure and chemical characteristics. In this work, alginates with different molecular weights and different mannuronic and guluronic acid residues ratio (M/G ratio) were used in the encapsulation of Lactococcus lactis spp. cremoris (LLC) aiming the protection of this probiotic bacteria against the harsh conditions of digestion. Alginate-based beads were produced using an external gelation process (extrusion technique) where variables regarding the processing conditions and alginate chemical characteristics were studied to assess their relevance in this process aiming the most efficient encapsulation system. The most important variables influencing the size of alginate beads were the alginate concentration, alginate type (M/G ratio and molecular weight) and the nozzle diameter. Beads with sizes ranged between 1.9 and 3.0 mm were produced using different alginates. Fourier transform infrared (FTIR) spectroscopy showed relevant differences between beads produced proving the impact of different M/G ratios in the beads chemical structure. In general, low molecular weight and low M/G ratio alginate (Protanal LFR5/60) proved to produce the most well organized (according to SEM analyses), less permeable (pore diameter of 2.52 nm) and stronger alginate beads, moreover molecular weight and M/G ratio proved to be an important variable on the protection of probiotics against the harsh conditions of digestion. Produced beads proved to be efficient in the protection of probiotics (i.e. high viability), with the best performance presented by the medium and low molecular weight alginates.The author Philippe E. Ramos would like to thank the Post-doc fellowship to the national agency Fundação para a Ciência e a Tecnologia (UID/BIO/04469) and to the European Regional Development Fund (FEDER) through COMPETE 2020 e Programa Operacional Competitividade e Internacionalização (POCI-01-0145-FEDER-006684). The authors thank the FCT Strategic Project PEstOE/EQB/LA0023/2013 and the project “BioInddBiotechnology and Bioengineering for Improved Industrial and Agro-Food Processes”, ref. NORTE-07-0124-FEDER-000028 cofunded by the Programa Operacional Regional do Norte (ON.2eO Novo Norte), QREN, FEDER.info:eu-repo/semantics/publishedVersio

Gender congruency goes Europe: A cross-linguistic study of the gender congruency effect in Romance and Germanic languages.

Theoretical and Experimental Linguistic

Two-Dimensional Nature of Four-Layer Superconductors by Inequivalent Hole Distribution

The magnetization of the four-layer superconductor CuBa_{2}Ca_{3}Cu_4O_{12-\delta} with T_c\simeq117 K is presented. The high-field magnetization around T_c(H) follows the exact two-dimensional scaling function given by Te\v{s}anovi\'{c} and Andreev. This feature is contrary to the inference that the interlayer coupling becomes strong if the number of CuO_2 planes in a unit cell increases. Also, the fluctuation-induced susceptibility in the low-field region was analyzed by using the modified Lawrence-Doniach model. The effective number of independently fluctuating CuO_2 layers per unit cell, g_{\rm eff}, turned out to be \simeq 2 rather than 4, which indicated that two among the four CuO_2 layers were in states far from their optimal doping levels. This result could explain why CuBa_{2}Ca_{3}Cu_4O_{12-\delta} shows two-dimensional behavior.Comment: 5 pages and 4 figure

Design and Operationalization of Connectivist Activities: an Approach through Business Process Management

International audienceThe work presented in this paper focuses on massive open online course (MOOC) environments, and more specifically on the activity of designing and implementing pedagogical scenarios for a connectivist MOOC (cMOOC). This paper presents a research work, which aims to propose a model and tool to support the design of connectivist MOOC scenarios. The major contribution of this work is a visual authoring tool that is intended for the design and deployment of cMOOC-oriented scenarios. The tool is based on the BPMN notation that we have extended to suit our objectives. The tool was evaluated primarily from the point of view of utility and usability. The findings confirm that the tool can be used to design connectivist pedagogical scenarios and can provide all the necessary elements to operationalize such courses

On the stability of 2 \sqrt{2} x 2 \sqrt{2} oxygen ordered superstructures in YBa2Cu3O6+x

We have compared the ground-state energy of several observed or proposed " 2 \sqrt{2} x 2 \sqrt{2} oxygen (O) ordered superstructures " (from now on HS), with those of "chain superstructures" (CS) (in which the O atoms of the basal plane are ordered in chains), for different compositions x in YBa2Cu3O6+x. The model Hamiltonian contains i) the Madelung energy, ii) a term linear in the difference between Cu and O hole occupancies which controls charge transfer, and iii) covalency effects based on known results for $t-J$ models in one and two dimensions. The optimum distribution of charge is determined minimizing the total energy, and depends on two parameters which are determined from known results for x=1 and x=0.5. We obtain that on the O lean side, only CS are stable, while for x=7/8, a HS with regularly spaced O vacancies added to the x=1 structure is more stable than the corresponding CS for the same x. We find that the detailed positions of the atoms in the structure, and long-range Coulomb interactions, are crucial for the electronic structure, the mechanism of charge transfer, the stability of the different phases, and the possibility of phase separation.Comment: 24 text pages, Latex, one fig. included as ps file, to be publisheb in Phys. Rev.

Phrase Frequency Effects in Language Production

A classic debate in the psychology of language concerns the question of the grain-size of the linguistic information that is stored in memory. One view is that only morphologically simple forms are stored (e.g., ‘car’, ‘red’), and that more complex forms of language such as multi-word phrases (e.g., ‘red car’) are generated on-line from the simple forms. In two experiments we tested this view. In Experiment 1, participants produced noun+adjective and noun+noun phrases that were elicited by experimental displays consisting of colored line drawings and two superimposed line drawings. In Experiment 2, participants produced noun+adjective and determiner+noun+adjective utterances elicited by colored line drawings. In both experiments, naming latencies decreased with increasing frequency of the multi-word phrase, and were unaffected by the frequency of the object name in the utterance. These results suggest that the language system is sensitive to the distribution of linguistic information at grain-sizes beyond individual words