Microstructural development during crystallization firing of a dental-grade nanostructured lithia-zirconia glass-ceramic

The microstructural development during crystallization firing of a commercially-available dental-grade nanostructured lithia-zirconia glass-ceramic (Vita Suprinity® PC) was unraveled using a wide battery of ex-situ and in-situ characterization techniques. It was found that the milling blocks are slightly crystallized glass-ceramics, with a complex chemical composition and consisting of partially de-polymerized glass plus lithium silicate (Li₂SiO₃) nanocrystals. It was also found that during crystallization firing the glassy matrix first reacts with part of the Li₂SiO₃ to form lithium disilicate (Li₂Si₂O₅) at ～810?820 °C, and then lithium orthophosphate (Li₃PO₄) precipitates from the glass. This results in glass-ceramics with abundant nanocrystals embedded in a sparse zirconosilicate glass matrix (containing many other cations subsumed) that, due to its high viscosity, inhibited crystal growth. Therefore, these dental glass-ceramics are not reinforced with zirconia (ZrO₂) crystals unless over-fired above ～890 °C and at the expense of its singular nanostructure. Finally, this study opens doors for optimizing the clinical performance of these dental glass-ceramics via microstructural tailoring.     

Utilization of Ultrasonic Measurements for Determining the Variations in Microstructure of Thermally Degraded 2205 Duplex Stainless Steel

The aim of this study is to investigate the changes in attenuation of longitudinal waves and velocity of shear wave modes for assessing variations in the microstructure of thermally degraded 2205 duplex stainless steel samples that were aged isothermally at 700°C and 900°C for different time intervals. The evaluation of material microstructural changes such as phase transformation and second phase precipitation which are related to material properties is of primary importance to ensure quality of components. This paper presents evidence that indicate that the attenuation coefficient of the longitudinal mode is sensitive to gradual microstructural changes produced by the aging treatments. The gradual changes in microstructure are associated with reduction of impact properties. On the other hand, for samples aged at 700°C, the velocity of the fast mode of shear wave show changes at high aging times and does not show changes at early aging times were the materials properties are already degraded.     

Are moods motivational states? A study on effort-related cardiovascular response.

Based on the mood-behavior-model (Gendolla, 2000), this study tested the idea that moods only have effects on effort mobilization in settings that directly call for this and in which people can thus use their moods as task-relevant information. Fifty university students were randomly assigned to a 2 (Mood: negative vs. positive) × 2 (Memorizing: intentional vs. incidental) × 2 (Time: mood induction vs. task performance) mixed model design. Effort mobilization was operationalized as systolic blood pressure (SBP) reactivity. As expected, in the intentional-memorizing condition, SBP reactivity was stronger in a negative mood than in a positive mood. Mood had no impact in the incidental-memorizing condition, which did not call for effort mobilization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Data mining and accelerated electronic structure theory as a tool in the search for new functional materials

A highly accelerated electronic structure implementation and data mining algorithms have been combined with structural data from the inorganic crystal structure database to generate materials properties for about 22,000 inorganic compounds. It is shown how data mining algorithms employed on the database can identify new functional materials with desired materials properties, resulting in a prediction of 136 novel materials with potential for use as detector materials for ionizing radiation. The methodology behind the automatized ab initio approach is presented, results are tabulated and a version of the complete database is made available at the internet web site <http://gurka.fysik.uu.se/ESP/> (Ref. [1]).     

Super sweet corn hybrid sh2 adaptability for industrial canning process

The super sweet corns Krispy king, Victor and 324 (sh2 hybrids) were evaluated to determine their adaptabilities to the industrial canning process as whole kernels. All these hybrids and Bonanza (control) were sown in San Joaquín (Carabobo, Venezuela), harvested and canned. After 110 days storage at room temperature they were analyzed to be compared physically, chemically and sensorially with Bonanza hybrid. Results did not show significant differences among most of the physical characteristics, except for percentage of broken kernels which was higher in 324 hybrid. Chemical parameters showed significant differences (P < 0.05) comparing each super sweet hybrid with Bonanza. The super sweet hybrids presented a higher sugar content and soluble solid of the brine than Bonanza, also a lower pH. The super sweet whole kernel presented a lower soluble solids content than Bonanza but they were not significant (Krispy king and 324). Appearance, odor and overall quality were the same for super sweet hybrids and Bonanza (su). Color, flavor and sweetness were better for 324 than all the other hybrids. Super sweet hybrids presented a very good adaptation to the canning process, having as an advantage that doesn't require sugar addition in the brine and a very good texture (firm and crispy).     

BCG vaccination policies in Mexico]

The authors report a 110 cervical cerclage operations for cervical incompetence. Shirodkar's technique was used and cerclage was carried out between the 9th and 20th week of amenorrhea. Out of 110 patients submitted to the procedure, 98 gave birth to a live infant weighing more than 1000 g which amounts to a success rate of 89%. Duration of pregnancy ranged between 26 and 41 weeks. If only pregnancies having proceeded to 37 weeks of amenorrhea are considered, the success rate amounts to 68%.     

Finite elements using a plane-wave basis for scattering of surface water waves

A generalized, frequency-independent, finite-element method is proposed for the numerical simulation of combined diffraction, refraction, radiation, reflection and absorption of water waves. Plane waves are used as an external function space, exploiting the standard set of approximation functions defined by the finite element method to enforce conformity and to impose boundary conditions in a straightforward manner by applying the method to the plane waves on each element. An integration method originally devised only for diffraction of waves by Ortiz and Sanchez in 2001 is extended to combined refraction and diffraction of high-frequency waves, retaining its dramatic savings in the number of operations for a given error compared with standard numerical integration methods.     

In situ FTIR monitoring of Ag and Au electrodeposition on glassy carbon and silicon

Formation of Ag, Au and Ag-Au alloys on Si and Glassy Carbon (GC) electrodes from alkaline cyanide electrolytes was investigated using a combination of electrochemical and spectroscopic techniques. Metal deposition and dissolution processes could be studied in situ by monitoring the ν(CN) bands of the metal complexes and the free cyanide ion in the region between 2000 and 2200 cm⁻¹ using FTIR reflectance spectroscopy. Under the experimental conditions, two different silver complexes, namely [Ag(CN)₂]⁻ and [Ag(CN)₃]²⁻ (whilst only one gold complex, namely [Au(CN)₂]⁻), were identified. In the case of the Ag-Au alloys, both species co-deposit even in the activation region, where Ag reduction is expected to be the main reaction. Experimental results indicate that in a mixed electrolyte containing equal amounts of Ag and Au, Ag deposition is thermodynamically favoured (), while Au deposition is kinetically favoured. The Ag-Au alloy deposition follows a progressive nucleation mechanism even at relatively high negative potentials. The morphology and adhesion of all deposits, as well as the alloy composition, were found to be strongly dependent on the deposition conditions. A better adhesion of the films with a higher Au content was observed, due to the formation of a more stable AuSi bond.