18,041 research outputs found
In-situ steel solidification imaging in continuous casting using magnetic induction tomography
: Solidification process in continuous casting is a critical part of steel production. The speed and quality of the solidification process determines the quality of final product. Computational fluid dynamics (CFD) simulations are often used to describe the process and design of its control system, but so far, there is no any tool that provides an on-line measurement of the solidification front of hot steel during the continuous casting process. This paper presents a new tool based on magnetic induction tomography (MIT) for real time monitoring of this process. The new MIT system was installed at the end of the secondary cooling chamber of a casting unit and tested during several days in a real production process. MIT is able to create an internal map of electrical conductivity of hot steel deep inside the billet. The image of electrical conductivity is then converted to temperature profile that allows the measurement of the solid, mushy and liquid layers. In this study, such a conversion is done by synchronizing in one time step the MIT measurement and the thermal map generated with the actual process parameters available at that time. The MIT results were then compared with the results obtained of the CFD and thermal modelling of the industrial process. This is the first in-situ monitoring of the interior structure during a real continuous casting.The SHELL-THICK project has received funding from EU Research Fund for Coal and Steel under grant number 709830. This study reflects only the author's views and the European Commission is not responsible for any use that may be made of the information contained therein
The U.S. Supreme Court Speaks on Voluntary School Integration Plans: Policy and Practice Implications for Educational Leaders
This article addresses important legal issues surrounding voluntary school integration plans and explores policy and practice implications of the Seattle and Louisville cases. School policy guidance for how school districts should create or change their voluntary integration policies is discussed. Further discussion reveals what some school districts around the nation are doing in light of the Seattle/Louisville decision. Additional discussion speaks of future policy possibilities for school districts and educational leaders to consider as a possible solution to creating voluntary school desegregation plans. Practical implications are addressed for middle and secondary school principals as school leaders who must deal with the outcomes produced by school district policies regarding integration plans.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
A strategy to qualify the performance of radiographic monitors
The purpose of this work was to compare standard desktop display systems with dedicated medical display systems. The set of image tests proposed by the American Association of Physicists in Medicine (AAPM TG18) was used to assess a Philips 107S desktop display system and a Siemens medical display. Three observers performed the subjective assessment, in a non-concerted manner. The objective assessment was performed using a CCD camera according to the AAPM TG18 procedure. The results clearly demonstrate the inadequacy of standard desktop display systems in the framework of diagnostic radiology. Moreover, a good correlation between the subjective and objective assessment methods was obtaine
Recent activity of the Be/X-ray binary system SAX J2103.5+4545
Aims. We present a multiwavelength study of the Be/X-ray binary system SAX
J2103.5+4545 with the goal of better characterizing the transient behaviour of
this source.
Methods. SAX J2103.5+4545 was observed by Swift-XRT four times in 2007 from
April 25 to May 5, and during quiescence in 2012 August 31. In addition, this
source has been monitored from the ground-based astronomical observatories of
El Teide (Tenerife, Spain), Roque de los Muchachos (La Palma, Spain) and Sierra
Nevada (Granada, Spain) since 2011 August, and from the TUBITAK National
Observatory (Antalya, Turkey) since 2009 June. We have performed spectral and
photometric temporal analyses in order to investigate the different states
exhibited by SAX J2103.5+4545.
Results. In X-rays, an absorbed power law model provided the best fit for all
the XRT spectra. An iron-line feature at ~6.42 keV was present in all the
observations except for that taken during quiescence in 2012. The photon
indexes are consistent with previous studies of SAX J2103.5+4545 in high/low
luminosity states. Pulsations were found in all the XRT data from 2007
(2.839(2) mHz; MJD 54222.02), but not during quiescence. Both optical outbursts
in 2010 and 2012 lasted for about 8/9 months (as the one in 2007 probably did
and the current one in 2014 might do) and were most probably caused by mass
ejection events from the Be star that eventually fed the circumstellar disc.
All of these outbursts started about 3 months before the triggering of the
X-ray activity, and about the same period before the maximum of the H_alpha
line equivalent width (in emission) was reached at only ~ -5 \AA. In this work
we found that the global correlation between the BV variability and the X-ray
intensity was also observed at longer wavelengths in the IR domain.Comment: 11 pages, 7 figures, and online material (2 tables). Submitted to A&A
in 2014 Januar
Tissue-Specific Transcriptomes Reveal Gene Expression Trajectories in Two Maturing Skin Epithelial Layers in Zebrafish Embryos.
Epithelial cells are the building blocks of many organs, including skin. The vertebrate skin initially consists of two epithelial layers, the outer periderm and inner basal cell layers, which have distinct properties, functions, and fates. The embryonic periderm ultimately disappears during development, whereas basal cells proliferate to form the mature, stratified epidermis. Although much is known about mechanisms of homeostasis in mature skin, relatively little is known about the two cell types in pre-stratification skin. To define the similarities and distinctions between periderm and basal skin epithelial cells, we purified them from zebrafish at early development stages and deeply profiled their gene expression. These analyses identified groups of genes whose tissue enrichment changed at each stage, defining gene flow dynamics of maturing vertebrate epithelia. At each of 52 and 72 hr post-fertilization (hpf), more than 60% of genes enriched in skin cells were similarly expressed in both layers, indicating that they were common epithelial genes, but many others were enriched in one layer or the other. Both expected and novel genes were enriched in periderm and basal cell layers. Genes encoding extracellular matrix, junctional, cytoskeletal, and signaling proteins were prominent among those distinguishing the two epithelial cell types. In situ hybridization and BAC transgenes confirmed our expression data and provided new tools to study zebrafish skin. Collectively, these data provide a resource for studying common and distinguishing features of maturing epithelia
- …