Microstructural Data (microstructural + data)

Distribution by Scientific Domains


Selected Abstracts


A Novel Approach to Study Biscuits and Breadsticks Using X-Ray Computed Tomography

JOURNAL OF FOOD SCIENCE, Issue 6 2010
P. Frisullo
Abstract:, In this study X-ray microtomography (,CT) was used for analysis of the microstructure of 6 different types of Italian biscuits and 3 types of Italian breadsticks. Appropriate quantitative 3-D parameters describing the microstructure were calculated, such as the structure thickness (ST), the object structure volume ratio (OSVR), the degree of anisotropy (DA), and the percentage object volume (POV). Sensory analysis was also performed to discriminate samples on the basis of texture characteristics. A correlation between microstructural data (OSVR for biscuits and OSVR, POV, and DA for breadsticks) and sample crunchiness was also found. Results obtained from the current study showed that analysis at a microscopic level could be useful to the food industry, as the accurate calculation of number, dimension, and distribution of pores in the products could be used to improve the sensorial properties of food. Further study by ,CT could be carried out to correlate microstructure to specific ingredients and process conditions to allow obtaining more tailored food. [source]


The integration of experimental in-situ EBSD observations and numerical simulations: a novel technique of microstructural process analysis

JOURNAL OF MICROSCOPY, Issue 3 2004
S. Piazolo
Summary The combination of subgrain- and grain-scale microstructural data collected during in-situ heating experiments and numerical simulations of equivalent microstructural development offers an innovative and powerful tool in the advancement of the understanding of microstructural processes. We present a system that fully integrates subgrain- to grain-scale crystallographic data obtained during in-situ observations during heating experiments in a scanning electron microscope and the two-dimensional hybrid numerical modelling system Elle. Such a system offers the unique opportunity to test and verify theories for microstructural development, as predictions made by numerical simulations can be directly coupled to appropriate physical experiments and, conversely, theoretical explanations of experimental observations should be testable with numerical simulations. Discrepancies between data obtained with both techniques suggest the need for an in-depth investigation and thus open up new avenues of theory development, modification and verification. In addition, because in numerical models it is possible to select the processes modelled, the effect of individual processes on the microstructural development of a specific material can be quantified. To illustrate the potential and methodology of the so-called EBSD2Elle system, two in-situ experiments and their equivalent numerical experiments are presented. These are static heating experiments of (a) an annealed Ni-foil coupled with a front tracking model for grain growth and (b) a cold deformed rock salt with kinetic Monte Carlo simulations for subgrain growth. [source]


Origin and phylogeny of Guyniidae (Scleractinia) in the light of microstructural data

LETHAIA, Issue 1 2000
Jaros, aw Stolarski
The set of skeletal characters of the Recent azooxanthellate coral Guynia annulata Duncan, 1872 is unique among extant scleractinians and encompasses: (a) undifferentiated septal calcification centers (in most extant scleractinians calcification centers are clearly separated); (b) completely smooth septal faces (septa of almost all extant scleractinians bear granular ornamentation); (c) deeply recessed septa in respect to the epithecal rim in the adult coralla (in adults of the majority of extant scleractinians the relationships between septa and wall are the reverse); and (d) an aseptal part of the initial ontogenetic stage, just above the basal plate (almost all known scleractinians have a septate initial coralla). Skeletal features of five other extant traditional guyniids are typical of other caryophylliines (and of Scleractinia). However, the wall types present in different species of traditional guyniids exceed limits traditionally attributed to one caryophylliine family: i.e., Stenocyathus and Truncatoguynia have a marginothecal wall like the Flabellidae, whereas Schizocyathus and Temnotrochus usually have an entirely epithecal wall, as in Gardineriidae (Volzeioidea). Moreover, Pourtalocyathus and Schizocyathus show intraspecific variation in distribution of septal calcification centers (separated vs. non-separated) and in wall types (epithecal vs. consisting of large spherulite-like bodies). These major differences in skeletal architecture form the basis for a new, threefold taxonomical subdivision of the traditional guyniids: (1) Guyniidae Hickson, 1910, containing only monospecific Guynia with an epithecal wall, and septa with non-separated calcification centers; (2) Schizocyathidae fam.n., groups Microsmilia Schizocyathus, Pourtalocyathus, Temnotrochus, which have an epithecal wall and septa with usually well-separated calcification centers; and (3) Stenocyathidae fam.n. with Stenocyathus and Truncatoguynia which have a marginothecal wall and septa with well-separated calcification centers. Despite differences in the basic architecture of the skeleton, all taxa attributed to these families have ,thecal pores' formed by selective dissolution of the skeleton. I propose two hypotheses for evolutionary relationships among Guyniidae, Schizocyathidae, and Stenocyathidae: (1) Hypothesis A: the three families are not phylogenetically related and ,pores' originated independently in different scleractinian lineages: e.g., Guyniidae may represent distant zardinophyllid or gigantostyliid descendants, Schizocyathidae may be a volzeioid offshoot, whereas Stenocyathidae may be a flabellid descendant; (2) Hypothesis B: the three families are phylogenetically related and ,thecal pores' are synapomorphic for the clade (superfamily Guynioidea). Additional approaches, such as anatomical observations, molecular studies on guyniid DNA sequences, and in-depth studies on scleractinian biomineralization will be necessary to test these hypotheses. [source]


Imaging and analysis of 3-D structure using a dual beam FIB

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2007
D. McGrouther
Abstract The application of focused ion beam instrumentation in the generation of three-dimensional microstructural data is described. The methodologies used to acquire and manipulate this data are explained, and the technique is illustrated by a number of examples from the material sciences. The limitations of this method, and practical pointers to the generation of meaningful data, are also discussed. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source]


Glass forming ability and nanocrystallization kinetics of Fe65Nb10B25 metallic glasses

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 5 2010
J. Torrens-Serra
Abstract In this work the mechanisms controlling the nanocrystallization kinetics of the Fe65Nb10B25 metallic glasses have been determined by the combination of the analysis microstructural data from XRD and TEM, and the kinetic analysis performed using the Master Curve method of the continuous heating and isothermal calorimetric curves. The results show that the transformation starts by the nucleation and interface controlled growth of the Fe23B6 -type phase that changes to diffusion controlled growth as the transformation advances until is stopped by the soft-impingement effect. The transformation is modeled in the framework of the Kolmogorov,Johnson,Mehl,Avrami (KJMA) theory using constant activation energy expressions for the nucleation frequency and interface-controlled growth and taking into account the reduction of those quantities with the transformed fraction due to the change in the matrix composition using a mean-field approximation. The parameters of the modeling are determined from the coupling between the isothermal and constant heating rate calorimetric analysis and from the quantitative analysis of microstructural data. This is the outset for the determination of the viscosity, driving force for crystallization, and interfacial energy when replacing the constant activation energy expressions by the classical nucleation and growth ones. Both the glass forming ability in Fe,Nb,B based bulk metallic glasses and the temperature dependence of the interfacial energy are discussed in terms of the influence of the minor alloying elements. [source]