Indentation-induced surface and subsurface deformation mechanisms in directionally solidified WC-W.sub.2C eutectoids are investigated. The microstructures of the WC-W.sub.2C composites consist of ...primary WC regions, W.sub.2C-rich regions, and lamellar-type eutectoid regions, which form during the sequential phase transformations during laser processing. Indentation-induced surface crack profiles indicate little propensity for debonding at the WC-W.sub.2C eutectoid interfaces, although some interactions with larger-scale microstructural features are observed. In the subsurface indentation regions, dislocation networks predominantly composed of partial dislocation pairs having Burgers vectors Formula omitted are observed in the primary WC regions, whereas shear banding and grain refinement are commonly observed in the micrometer-scale W.sub.2C-rich regions. Deformation in the sub-micrometer eutectoid regions is distinct, with the dislocation activity primarily limited to the WC phase, with Burgers vectors of Formula omitted that terminate at the interfaces.
Radon, thoron, and their progeny concentrations, seasonal variation in the indoor environment have been measured for dose assessment to the residents for first time using a single-entry pinhole ...dosimeters and deposition-based radon/thoron progeny sensors. A total of 100 dosimeters were deployed in 25 villages. These values are found to be higher in winter than rainy and summer season which may be due to inadequate ventilation conditions. The average annual effective inhalation dose has been found to be 0.90 mSvy.sup.-1, which is below the recommended level of International Commission on Radiological Protection.
Ammonia (NH.sub.3) in the atmosphere affects both the environment and human health. It is therefore increasingly recognised by policy makers as an important air pollutant that needs to be mitigated, ...though it still remains unregulated in many countries. In order to understand the effectiveness of abatement strategies, routine NH.sub.3 monitoring is required. Current reference protocols, first developed in the 1990s, use daily samplers with offline analysis; however, there have been a number of technologies developed since, which may be applicable for high time resolution routine monitoring of NH.sub.3 at ambient concentrations. The following study is a comprehensive field intercomparison held over an intensively managed grassland in southeastern Scotland using currently available methods that are reported to be suitable for routine monitoring of ambient NH.sub.3 . In total, 13 instruments took part in the field study, including commercially available technologies, research prototype instruments, and legacy instruments. Assessments of the instruments' precision at low concentrations ( 10 ppb) and at elevated concentrations (maximum reported concentration of 282 ppb) were undertaken. At elevated concentrations, all instruments performed well and with precision (r.sup.2 0.75). At concentrations below 10 ppb, however, precision decreased, and instruments fell into two distinct groups, with duplicate instruments split across the two groups. It was found that duplicate instruments performed differently as a result of differences in instrument setup, inlet design, and operation of the instrument.
El desarrollo de las competencias investigativas es una de las preocupaciones actuales de las universidades, las cuales deben ser atendidas tanto en el desarrollo de habilidades investigativas como ...en la construccion de instrumentos para su evaluacion permanente. En el presente estudio cualitativo de tipo documental se evaluan las semejanzas y diferencias entre los instrumentos de medicion de las competencias investigativas segun los criterios: dimensiones, tipos de validez, confiabilidad, la muestra, los paises y el ano en que fueron aplicados. Las fuentes de informacion consideradas fueron: EBSCOhost, ProQuest, Web of Science (WoS), Google Academico y Redalyc. Se seleccionaron trece articulos que cumplieron los criterios de limite de tiempo entre los anos 2016 y 2021; idioma espanol e ingles, calidad informativa y ambito universitario. Se determino que los instrumentos generalmente utilizan en su construccion aspectos referidos a competencias tecnologicas o digitales y procedimentales segun el desarrollo de proyectos de investigacion, aunque si muestran una alta consistencia interna y procesos de validez de constructo y juicio de expertos. Estos resultados apoyan la idea de que se deben elaborar instrumentos, para estudiantes y docentes, que incluyan en su construccion la mayor diversidad de dimensiones que evidencien su evaluacion y nivel de logro.
Purpose:
The quantification of body fat plays an important role in the study of numerous diseases. It is common current practice to use the fat area at a single abdominal computed tomography (CT) ...slice as a marker of the body fat content in studying various disease processes. This paper sets out to answer three questions related to this issue which have not been addressed in the literature. At what single anatomic slice location do the areas of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) estimated from the slice correlate maximally with the corresponding fat volume measures? How does one ensure that the slices used for correlation calculation from different subjects are at the same anatomic location? Are there combinations of multiple slices (not necessarily contiguous) whose area sum correlates better with volume than does single slice area with volume?
Methods:
The authors propose a novel strategy for mapping slice locations to a standardized anatomic space so that same anatomic slice locations are identified in different subjects. The authors then study the volume-to-area correlations and determine where they become maximal. To address the third issue, the authors carry out similar correlation studies by utilizing two and three slices for calculating area sum.
Results:
Based on 50 abdominal CT data sets, the proposed mapping achieves significantly improved consistency of anatomic localization compared to current practice. Maximum correlations are achieved at different anatomic locations for SAT and VAT which are both different from the L4-L5 junction commonly utilized currently for single slice area estimation as a marker.
Conclusions:
The maximum area-to-volume correlation achieved is quite high, suggesting that it may be reasonable to estimate body fat by measuring the area of fat from a single anatomic slice at the site of maximum correlation and use this as a marker. The site of maximum correlation is not at L4-L5 as commonly assumed, but is more superiorly located at T12-L1 for SAT and at L3-L4 for VAT. Furthermore, the optimal anatomic locations for SAT and VAT estimation are not the same, contrary to common assumption. The proposed standardized space mapping achieves high consistency of anatomic localization by accurately managing nonlinearities in the relationships among landmarks. Multiple slices achieve greater improvement in correlation for VAT than for SAT. The optimal locations in the case of multiple slices are not contiguous.
We investigate interacting scenarios that belong to a wider class, since they include a dynamical dark energy component whose equation of state follows various one-parameter parametrizations. We ...confront them with the latest observational data from the cosmic microwave background, the joint light-curve sample from type Ia supernovae, baryon acoustic oscillations, Hubble parameter measurements from cosmic chronometers (CC), and a Gaussian prior on the Hubble parameter H0. In all examined scenarios we find a nonzero interaction; nevertheless, the noninteracting case is allowed within 2σ. Concerning the current value of the dark energy equation of state for all combinations of data sets, it always lies in the phantom regime at more than 2–3 standard deviations. Finally, for all interacting models, independently of the combination of data sets considered, the estimated values of the present Hubble parameter H0 are greater compared to the ΛCDM-based Planck estimate and close to the local measurements, thus alleviating the H0 tension.
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