Dowel space preparation in root canals filled with glass ionomer cement

To assist beginners in the microsurgical practices of handling instruments and tying knots before using an animal model, the authors suggest the use of colored beads. These beads will diminish eyestrain and secondary fatigue. Also, working with colored beads might be a little more amusing and enjoyable for beginners in learning microsurgical techniques during preliminary studies to achieve the necessary orientation for working under the operating microscope.     

An integrated device for monitoring time-dependent in vitro expression from single genes in picolitre droplets

Microdroplets have great potential for high-throughput biochemical screening. We report the design of an integrated microfluidic device for droplet formation, incubation and screening. Picolitre water-in-oil droplets can be stored in a reservoir that contains approximately 10(6) droplets. In this reservoir droplets are stable for at least 6 h, which gives an extended timescale for biochemical experiments. We demonstrate the utility of the system by following the in vitro expression of green fluorescent protein. The high efficiency allows protein expression from a single molecule of DNA template, creating "monoclonal droplets" in which genotype and phenotype are combined in one emulsion compartment.     

Young children extend novel words at the basic level: Evidence for the principle of categorical scope.

If young children approached the task of word learning with a specific hypothesis about the meaning of novel count nouns, they could make the problem of word learning more tractable. Six experiments were conducted to test children's hypotheses about how labels map to object categories. Findings indicated that (a) 3- and 4-year-olds function with an antithematic bias; (b) children do not reliably extend novel nouns to superordinate exemplars when perceptual similarity is controlled until approximately age 7; and (c) children expect novel nouns to label taxonomic categories at the basic level, even in the presence of a perceptually compelling distractor. Results are interpreted as supporting the principle of categorical scope (R. M. Golinkoff, C. B. Mervis, & K. Hirsh-Pasek; see record 1994-40565-001). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification of instantaneous attributes of torsional shaft signals using the Hilbert transform

A systematic analytical procedure based on the concept of the analytic signal (AS) of Gabor is used to determine the time-varying attributes of torsional oscillations, namely the instantaneous amplitude and the instantaneous frequency. Methods for implementing the AS using the numeric Hilbert transform are given and criteria for characterizing nonlinear effects are discussed. The proposed methodology is demonstrated on the IEEE First Benchmark Model (FBM) for subsynchronous resonance studies. The AS analysis is performed on output data files generated by nonlinear simulations using the EMTP, but the method is general and is applicable to any nonlinear, nonstationary signal. Numerical results include the determination of the instantaneous frequency of torsional oscillation signals following large perturbations. Comparison of numerical results obtained by the proposed method with linear analysis techniques is provided.     

Aspects of dispersion and flow in thermoplastic-elastomer blends

Polypropylene, polystyrene, EP (ethylene/propylene) rubber, and bromobutyl rubber were blended under standardized conditions and the sizes of minor phase domains determined by Quantimet analysis. Dispersion effectiveness was found to depend on the melt viscosities of components under mixing conditions and on their “compatibilty” as inferred here from surface-tension data. Dispersion was optimized when components wet readily at contact surfaces and when melt viscosities were similar. Shear heating during dispersion appeared to offer an empirical index of component compatibilty. Apparent melt viscosities of the blends further reflected the component compatibility factor.     

A carbonate-free,sulfone-based electrolyte for high-voltage Li-ion batteries

Practical implementation of next-generation Li-ion battery chemistries is to a large extent obstructed by the absence of an electrolyte that is capable of simultaneously supporting reversible electrochemical reactions at two extreme electrochemical potentials—above 4.5?V at the positive electrode and near 0?V vs. Li at the negative electrode. Electrolytes based on carbonate esters have been reliable in satisfying state-of-the-art Li-ion battery (LIB) chemistries below <4.2?V; however, it is the intrinsic thermodynamic tendency of these carbonates to decompose at potentials well below the thermodynamic threshold required for reversible reactions of high-voltage systems (>4.4?V), releasing CO₂. In this work, we explore a carbonate-free electrolyte system based on a single sulfone solvent, in which a newly discovered synergy between solvent and salt simultaneously addresses the interfacial requirements of both graphitic anode and high-voltage cathode (LiNi_0.5Mn_1.5O₄ (LNMO)). Experimental measurements, quantum chemistry (QC) calculations, and molecular dynamics simulations reveal the system’s fast ion conduction, stability over a wide temperature range, and non-flammability. At the anode, a LiF-rich interphase generated by early-onset reduction of the salt anion effectively suppresses solvent co-intercalation and subsequent graphite exfoliation, enabling unprecedented and highly reversible graphite cycling in a pure sulfone system. Under oxidative conditions, QC calculations predict that high salt concentration promotes complex/aggregate formation which slow the decomposition of sulfolane and leads to polymerizable rather than gaseous products—a fundamental improvement over carbonate solvents. These predictions are corroborated by X-ray photoelectron spectroscopy (XPS), cryogenic-transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS) experiments, which revealed the presence of a thin, conformal, sulfur-based cathode electrolyte interphase (CEI). Together, the functional interphases (SEI/CEI) generated by this electrolyte system supported long term operation of a high-voltage (4.85?V) LNMO/graphite full cell, which retained ～70% of its original first-cycle discharge capacity after the 1000th cycle. Based on these results, this new carbonate-free electrolyte system, supported by the mechanistic understanding of its behavior, presents a promising new direction toward unlocking the potential of next generation Li-ion battery electrodes.     

Growing Details

Here David Benjamin and Danil Nagy of New York-based practice The Living, and Carlos Olguin of Autodesk Research, describe how in their design for the Evolving Chair they piloted Project Cyborg, a cloud-native meta-platform for matter programming. By providing a range of design opportunities at multiple scales, Cyborg seeks to introduce a more fluid and open-ended approach to detailing that is less confined by matter and scale.     

Odour sampling system with modifiable parameters applied to fruit classification

The aroma emanating from fruits can indicate the maturity level and thus the quality and shelf life of the products. In this work it is presented an odour sampling system system (called also electronic nose), to classify the aroma of Diospyros kaki, whose working parameters can have variable configuration making the system flexible. The system can be appropriately reconfigured for each type of sampling. It is formed by a metal oxide semiconductor (MOS) commercial sensors matrix, which are individually controlled, being able to modify by software several parameters of their operating point. Working this way there is not a limited number of sensors but a very high number of virtual sensors. The system shows the ability to discriminate aroma of two Diospyros kaki cultivars. Moreover the instrument is capable to distinguish the fruits, inside the persimmon cultivar cluster, according to the ripe state after few days of storage.