Measurements of Soot Temperature in a Diffusion Flame Using a Digital Camera

Temperatures were measured in a laminar axisymmetric diffusion flame with a digital camera. The camera was a Nikon D700, modified to remove the Infra-Red (IR) cut filter and the anti-aliasing filter. Temperatures were obtained using ratio pyrometry at 550, 650, and 900 nm following deconvolution. The camera was calibrated with a blackbody furnace. Measurements were made for an 88 mm high laminar ethylene/air diffusion flame in co-flow on a burner with an 11.1 mm inside diameter. Soot temperatures were measured in the range of 1250 - 2000 K with an estimated uncertainty of ±60 K. The diagnostic requires axisymmetric, optically thin flames, and regions with temperatures greater than 1250 K and soot volume fractions greater than 0.1 ppm. The results agreed with published measurements for this flame. The new diagnostics provide a convenient and economical way to perform these measurements with good accuracy and spatial resolution

Effect of Chain Stiffness on the Structure of Single-Chain Polymer Nanoparticles

Polymeric single-chain nanoparticles (SCNPs) are soft nano-objects synthesized by purely intramolecular cross-linking of single polymer chains. By means of computer simulations, we investigate the conformational properties of SCNPs as a function of the bending stiffness of their linear polymer precursors. We investigate a broad range of characteristic ratios from the fully flexible case to those typical of bulky synthetic polymers. Increasing stiffness hinders bonding of groups separated by short contour distances and increases looping over longer distances, leading to more compact nanoparticles with a structure of highly interconnected loops. This feature is reflected in a crossover in the scaling behaviour of several structural observables. The scaling exponents change from those characteristic for Gaussian chains or rings in $\theta$-solvents in the fully flexible limit, to values resembling fractal or `crumpled' globular behaviour for very stiff SCNPs. We characterize domains in the SCNPs. These are weakly deformable regions that can be seen as disordered analogues of domains in disordered proteins. Increasing stiffness leads to bigger and less deformable domains. Surprisingly, the scaling behaviour of the domains is in all cases similar to that of Gaussian chains or rings, irrespective of the stiffness and degree of cross-linking. It is the spatial arrangement of the domains which determines the global structure of the SCNP (sparse Gaussian-like object or crumpled globule). Since intramolecular stiffness can be varied through the specific chemistry of the precursor or by introducing bulky side groups in its backbone, our results propose a new strategy to tune the global structure of SCNPs.Comment: 20 pages, 17 figure

De las emociones a la conexión mente-cuerpo: La contribución de Nina Bull

Se revisa la producción de Nina Bull y se le comenta como un anticipo de la Inteligencia Emocional.Se analiza la importancia dada por esta utora a las Emociones, lo que le convierte en una pionera de la Inteligencia Emocional.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Papilla preservation periodontal surgery in periodontal reconstruction for deep combined intra-suprabony defects. Retrospective analysis of a registry-based cohort

Suprabony defects are the most prevalent defects and there is very little evidence on their treatment. This study aims to assess the effectiveness of papilla preservation periodontal surgery in the periodontal reconstruction of combined deep intra-suprab

Implementation of the Ensemble Kalman Filter in the Characterization of Hydraulic Fractures in Shale Gas Reservoirs by Integrating Downhole Temperature Sensing Technology

Multi-stage hydraulic fracturing in horizontal wells has demonstrated successful results for developing unconventional low-permeability oil and gas reservoirs. Despite being vastly implemented by different operators across North America, hydraulic fracture treatments are still not fully comprehended and have proved to have a more complex behavior than initially thought. To fill this knowledge gap and monitor the performance of hydraulic fracture treatments, fracture diagnostic tools are deployed in order to obtain information that can give a better insight of the reservoir and hydraulic fracture conditions. A technique that has demonstrated great potential in the monitoring of hydraulic fracture treatments is distributed temperature sensing technology. In situations where pressure and/or flow rate data is not reliable or in conflict with the known physics of the reservoir, continuous temperature data can be used as an alternative source of information since it effectively responds to pressure or flow rate changes when looked at a finer scale. Qualitative information such as fracture initiation points, vertical coverage and number of created fractures can be identified via distributed temperature sensors however; more quantitative results are needed in order to accurately characterize hydraulic fractures in shale gas reservoirs. In this study, a stochastic inverse problem is set up with the objective of inferring hydraulic fracture characteristics, such as fracture half-length and permeability, by assimilating data from downhole temperature sensors. The ensemble Kalman filter is implemented to assimilate DTS data and estimate fracture parameters. This inverse method is suitable for applications to non-linear assimilation problems and is, by nature, an appropriate approach for monitoring. In this way, the ensemble Kalman filter enables a quantitative fracture characterization and automatic history matching. Furthermore, the EnKF offers several advantages for this application, including the ensemble formulation for uncertainty assessment, convenient gradient-free implementation, and the flexibility to incorporate additional monitoring data types. The validity of the method is examined using synthetic models, and finally, field data from a horizontal gas well in the Marcellus shale

The barley a-thionin promotor is rich in negative regulatory motifs and directs tissue-specific expression of a reporter gene in tobacco.

The promoter of the barley α-thionin gene (1.6 kb) fused to the β-glucuronidase (GUS) gene directs temporally-controled, tissue-specific expression in the endosperm of transgenic tobacco. The nucleotide sequence of this promoter shows negative regulatory motifs which have been functionally analyzed in other gene

Brewster quasi bound states in the continuum in all-dielectric metasurfaces from single magnetic-dipole resonance meta-atoms

Bound states in the continuum (BICs) are ubiquitous in many areas of physics, attracting especial interest for their ability to confine waves with infinite lifetimes. Metasurfaces provide a suitable platform to realize them in photonics; such BICs are remarkably robust, being however complex to tune in frequency-wavevector space.Here we propose a scheme to engineer BICs and quasi-BICs with single magnetic-dipole resonance meta-atoms. Upon changing the orientation of the magnetic-dipole resonances, we show that the resulting quasi-BICs,emerging from the symmetry-protected BIC at normal incidence, become transparent for plane-wave illumination exactly at the magnetic-dipole angle, due to a Brewster-like effect. While yielding infinite Q-factors at normalincidence(canonical BIC), these are termed Brewster quasi-BICs since a transmission channel is always allowed that slightly widens resonances at oblique incidences. This is demonstrated experimentally through reflectance measurements in the microwave regime with high-refractive-index mm-disk metasurfaces. Such Brewster-inspired configuration is a plausible scenario to achieve quasi-BICs throughout the electromagnetic spectrum inaccessible through plane-wave illumination at given angles, which could be extrapolated to other kind of waves.Comment: 15 pages, 7 figures; typos corrected, Figs. 3 & 5 modified, new Fig. 7 & references adde