180 research outputs found
Influence of heating temperature on the aluminum used for electric cables
In this study, we present the effects of temperature rise on microstructural evolution of industrial Al wire. This material is used to manufacture electric cables. For the X-ray analysis of the line profile (LPA), we have chosen the so-called «breadth method» whose basic principle is to draw the Williamson-Hall plot. We have observed that the increase in temperature causes the increasing of coherent diffraction domains (crystallites) size, interplanar distance and cell parameter. There is an expansion of the unit cell. XRD patterns refinement were performed using the whole powder pattern modelling procedure implemented in PM2k software
Experimental investigation of industrial copper deformed by wire drawing process
The scope of this work is to investigate the effect of the cold deformation by wire-drawing on microstructure and physical properties of industrial copper wires. Copper wires were provided by E.N.I.CA.Biskra (Algeria). We investigated some wires with different strain levels (as received, 1.20, 2.10, and ε = 3.35). X-ray diffraction, optical microscopy, and electrical resistivity measurement have been used as characterization techniques. We analyzed the photographs using “ImageJ” software and DRX patterns using PM2K software. The results revealed that the cold wire-drawing causes a lengthening of grains along the axis of wire-drawing, and introduced large amounts of defects. The results also showed, on the one hand, the decrease in crystallite size, lattice parameter, and the outer cut-off radius, on the other hand, the increase of the electrical resistivity and the dislocation density in the copper wires.Keywords: Industrial copper; deformation; Dislocations; Shape factor; X-ray diffraction
The Cost of Monitoring Alone
We compare the succinctness of two monitoring systems for properties of
infinite traces, namely parallel and regular monitors. Although a parallel
monitor can be turned into an equivalent regular monitor, the cost of this
transformation is a double-exponential blowup in the syntactic size of the
monitors, and a triple-exponential blowup when the goal is a deterministic
monitor. We show that these bounds are tight and that they also hold for
translations between corresponding fragments of Hennessy-Milner logic with
recursion over infinite traces.Comment: 22 page
SHINE Transcription Factors Act Redundantly to Pattern the Archetypal Surface of Arabidopsis Flower Organs
Floral organs display tremendous variation in their exterior that is essential for organogenesis and the interaction with the environment. This diversity in surface characteristics is largely dependent on the composition and structure of their coating cuticular layer. To date, mechanisms of flower organ initiation and identity have been studied extensively, while little is known regarding the regulation of flower organs surface formation, cuticle composition, and its developmental significance. Using a synthetic microRNA approach to simultaneously silence the three SHINE (SHN) clade members, we revealed that these transcription factors act redundantly to shape the surface and morphology of Arabidopsis flowers. It appears that SHNs regulate floral organs' epidermal cell elongation and decoration with nanoridges, particularly in petals. Reduced activity of SHN transcription factors results in floral organs' fusion and earlier abscission that is accompanied by a decrease in cutin load and modified cell wall properties. SHN transcription factors possess target genes within four cutin- and suberin-associated protein families including, CYP86A cytochrome P450s, fatty acyl-CoA reductases, GSDL-motif lipases, and BODYGUARD1-like proteins. The results suggest that alongside controlling cuticular lipids metabolism, SHNs act to modify the epidermis cell wall through altering pectin metabolism and structural proteins. We also provide evidence that surface formation in petals and other floral organs during their growth and elongation or in abscission and dehiscence through SHNs is partially mediated by gibberellin and the DELLA signaling cascade. This study therefore demonstrates the need for a defined composition and structure of the cuticle and cell wall in order to form the archetypal features of floral organs surfaces and control their cell-to-cell separation processes. Furthermore, it will promote future investigation into the relation between the regulation of organ surface patterning and the broader control of flower development and biological functions
Glioma imaging in Europe: A survey of 220 centres and recommendations for best clinical practice
Objectives: At a European Society of Neuroradiology (ESNR) Annual Meeting 2015 workshop, commonalities in practice, current controversies and technical hurdles in glioma MRI were discussed. We aimed to formulate guidance on MRI of glioma and determine its feasibility, by seeking information on glioma imaging practices from the European Neuroradiology community. Methods: Invitations to a structured survey were emailed to ESNR members (n=1,662) and associates (n=6,400), European national radiologists’ societies and distributed via social media. Results: Responses were received from 220 institutions (59% academic). Conventional imaging protocols generally include T2w, T2-FLAIR, DWI, and pre- and post-contrast T1w. Perfusion MRI is used widely (85.5%), while spectroscopy seems reserved for specific indications. Reasons for omitting advanced imaging modalities include lack of facility/software, time constraints and no requests. Early postoperative MRI is routinely carried out by 74% within 24–72 h, but only 17% report a percent measure of resection. For follow-up, most sites (60%) issue qualitative reports, while 27% report an assessment according to the RANO criteria. A minori
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