Search results for " Shape"
showing 10 items of 298 documents
The effect of magnetocrystalline anisotropy on the domain structure of patterned Fe2CrSi Heusler alloy thin films
2013
The effects of magnetic anisotropy on domain structures in half-metallic Heusler alloy Fe2CrSi thin film elements were investigated using high resolution x-ray magnetic circular dichroism photoemission electron microscopy. The transition of the dominating contribution from the magnetocrystalline anisotropy to the shape anisotropy is observed in square-shaped elements when reducing the size below 2.0–2.5 μm. In particular, we identify in disk-shaped Heusler elements the vortex state as the ground state. The shape-anisotropy dominated, well-defined magnetization configuration shows the potential of the Fe2CrSi Heusler alloy for applications in vortex-core- or domain-wall-devices, where the hi…
Unusual domain-wall motion in ferromagnetic semiconductor films with tetragonal anisotropy
2009
International audience; Magnetic field-driven domain-wall propagation in the flow regime is investigated in (Ga, Mn) As ferromagnetic semiconductor layers. Square-shape magnetic domains with an unexpected orientation of their edges, at pi/8 with respect to the anisotropy axes, are found. This is shown to arise from the effect of tetragonal magnetic anisotropy on domain-wall dynamics. Using a one-dimensional model for domain-wall motion and modeling domain growth by contour dynamics the shape and orientation of domains and their field range for existence are well reproduced. These results point to the key role of the vectorial nature of the order parameter in the dynamics of ferromagnetic do…
Apparent boudinage in dykes
2004
Intrusive rocks may be arranged in the form of strings of lenses or beads, as found on the Cap de Creus Peninsula, NE Spain, and in the South Finland Migmatite-Granite Belt. These structures first appear to be the result of stretching and boudinage of intrusive sheets or dykes. However, closer examination reveals that they are not boudins, but are instead primary intrusive structures. A detailed study was performed on a swarm of pegmatite intrusions at Cap de Creus. Layering is often continuous between beads, and, in some cases, individual beads exhibit a very irregular shape. These observations are shown to be incompatible with an origin by boudinage. Analogue experiments were used to test…
An expanded model and application of the combined effect of crystal-size distribution and crystal shape on the relative viscosity of magmas
2018
International audience; This study examines the combined effect of crystal-size distributions (CSD) and crystal shape on the rheology of vesicle free magmatic suspensions and provides the first practical application of an empirical model to estimate the relative effect of crystal content and CSD's on the viscosity of magma directly from textural image analysis of natural rock samples in the form of a user-friendly texture-rheology spreadsheet calculator. We extend and apply established relationships between the maximum packing fraction ϕm of a crystal bearing suspension and both its rheological properties and the polydispersity γ of a CSD. By using analogue rotational rheometric experiments…
Impact of Coseismic Frictional Melting on Particle Size, Shape Distribution and Chemistry of Experimentally-Generated Pseudotachylite
2020
In natural friction melts, or pseudotachylites, clast textures and glass compositions can influence the frictional behavior of faults hosting pseudotachylites, and are, in turn, sensitive to the processes involved in pseudotachylite formation. Quantification of these parameters in situations where the host rock composition and formation conditions are well-constrained, such as analogue experiments, may yield calibrations that can be employed in analysis of natural pseudotachylites. In this paper, we experimentally-generated pseudotachylites in granitoid rocks (tonalite and Westerly granite) at Pconf= 40 MPa and slip rates of ∼0.1 m s−1, comparable to the conditions under which natural pseud…
Phenotypic traits of berries and seeds of Sicilian grape cultivars (Vitis vinifera L.)
2020
Abstract Grapevine is characterized by high variability in seed and berry morphology and their phenotypic traits are usually used to describe V. vinifera varieties. The goal of this study was to investigate the phenotypic diversity of berry and seed traits and the relationships between berry and seed morphological characteristics of autochthonous accessions of Sicilian germplasm. In two seasons, twenty bunches per cultivar were harvested at technological maturity. Berry weight; berry longitudinal and transversal diameters; seed number/weight per berry; and seed length, thickness, width and beak length were determined, after which the diameter ratio was calculated. Black and white cultivars …
Whole-genome resequencing of Cucurbita pepo morphotypes to discover genomic variants associated with morphology and horticulturally valuable traits
2019
[EN] Cucurbita pepo contains two cultivated subspecies, each of which encompasses four fruit-shape morphotypes (cultivar groups). The Pumpkin, Vegetable Marrow, Cocozelle, and Zucchini Groups are of subsp. pepo and the Acorn, Crookneck, Scallop, and Straightneck Groups are of subsp. ovifera. Recently, a de novo assembly of the C. pepo subsp. pepo Zucchini genome was published, providing insights into its evolution. To expand our knowledge of evolutionary processes within C. pepo and to identify variants associated with particular morphotypes, we performed whole-genome resequencing of seven of these eight C. pepo morphotypes. We report for the first time whole-genome resequencing of the four…
Chlorophyll fluorescence emission spectrum inside a leaf
2008
International audience; Chlorophyll a fluorescence can be used as an early stress indicator. Fluorescence is also connected to photosynthesis so it can be proposed for global monitoring of vegetation status from a satellite platform. Nevertheless, the correct interpretation of fluorescence requires accurate physical models. The spectral shape of the leaf fluorescence free of any re-absorption effect plays a key role in the models and is difficult to measure. We present a vegetation fluorescence emission spectrum free of re-absorption based on a combination of measurements and modelling. The suggested spectrum takes into account the photosystem I and II spectra and their relative contributio…
Modularity as a source of new morphological variation in the mandible of hybrid mice.
2012
Abstract Background Hybridization is often seen as a process dampening phenotypic differences accumulated between diverging evolutionary units. For a complex trait comprising several relatively independent modules, hybridization may however simply generate new phenotypes, by combining into a new mosaic modules inherited from each parental groups and parts intermediate with respect to the parental groups. We tested this hypothesis by studying mandible size and shape in a set of first and second generation hybrids resulting from inbred wild-derived laboratory strains documenting two subspecies of house mice, Musmusculus domesticus and Musmusculus musculus. Phenotypic variation of the mandible…
Relationship between seed morphological traits and ash and mineral distribution along the kernel using debranning in durum wheats from different geog…
2020
Debranning was applied to durum wheat to the study the relationship between kernel shape and size, and ash and mineral distribution having implications for semolina yield. To this aim four durum wheat genotypes carried out over three environments were selected to determine the morphological and yield traits as well as the distribution along the kernel of the ash, macro- (Na, K, P, Ca, and Mg), and micro-elements (Mn, Fe, Cu, Zn, and Mo). A descendent ash gradient within the kernel reflects the decreases in the minerals that occurred during debranning. Perciasacchi with high seed weight (TKW) and greater thickness followed by Cappelli showed a more uniform distribution of ash content along t…