Results 1 - 10 of 9225
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[en] The proposed mechanisms which may account for nodular corrosion refer to texture variations, precipitates, composition of the alloys as well as the hydrogen produced during exposure. Our investigations show that other features are to be considered. (orig./RK)
[en] Tessellated surfaces are structured surfaces where the dominant features are organized in periodic patterns. Tessellated surfaces are becoming increasingly popular for a wide variety of industrial uses. However, their uptake is hindered by a lack of suitable metrological techniques to categorize and verify their properties. Areal surface texture parameters, commonly used for characterization of surface texture, may not provide relevant information for characterizing the periodicity and the other functionally relevant geometric attributes of the pattern. A recently proposed solution is to directly retrieve the individual features of the pattern and to determine their relevant geometric and dimensional properties. To identify individual features it is necessary to segment the surface in order to extract the pattern units (tiles) and the individual features contained within, so that their properties can be assessed. This paper reviews a number of different techniques to segment tessellated surfaces and compares their ability to accurately identify features and their boundaries. The ability to identify features is important as it has a direct impact on the computation of dimensional and geometric properties of the features. (topical review)
[en] We study supercurrents of 3He-A through narrow pores and find such currents to vanish in many cases because of end effects at the entries and exits of the pores. Under constant pressure DC-supercurrents are found to arise. We also consider the effects of finite frequencies on the end effects. (author)
[en] In this paper, the foundations for new methodology creation which provides solving problem of surfaces structure new standards parameters huge amount conflicted with necessary actual floors quantity of surfaces structure parameters which is related to measurement complexity decreasing are considered. At the moment, there is no single assessment of the importance of a parameters. The approval of presented methodology for aerospace cluster components surfaces allows to create necessary foundation, to develop scientific estimation of surfaces texture parameters, to obtain material for investigators of chosen technological procedure. The methods necessary for further work, the creation of a fundamental reserve and development as a scientific direction for assessing the significance of microgeometry parameters are selected. (paper)
[en] For the study of texture in orthorhombic system materials, pole figures of uranium specimens were measured using neutron diffraction and their quantitative analysis were made by developing computer code TEXFBI based on Bunge formalism during '84-'85. In the analysis, a method to resolve composite pole figure was tried to increase maximum number of input pole figures and ODF series expansion terms. However, it has been found that the constrain conditions on mixing coefficients(qij) are not properly satisfied during iteration and the result is dependant on strating qij values. To solve this problem, starting qij values are computed based on crystallograpic data and instrumental resolution and the steepest descent method is used for computation. This method can improve average error for pole figure(p) up to 0.23% for hot-rolled uranium specimen (600-650 deg C, texture index: J=4.8) when analyzed with Ip=10 and L=16, as a typical example. The configuration of 7 horizontal beam tubes has been determined around KMRR core, 4 standard type beam tubes, 1 cold neutron beam tube, 1 irradiation study beam tube, and 1 neutron radiography beam tube, and evaluation of neutron field characteristics at the nose of these beam tubes is made. Design works for optimum beam tube shapes, structures, and auxillary facilities such as inpile collimators and rotating beam shutters etc. are in progress along with preparations for the basic design of neutron spectrometers to be installed at the beam tubes. (Author)
[en] Highlights: • Texture analysis may predict early colorectal liver metastases occurring ≤6 months. • Texture analysis may be a helpful adjunct to other clinical parameters. • Texture analysis cannot predict liver metastases occurring within 7–24 months. - Abstract: Objectives: CT texture analysis has shown promise to differentiate colorectal cancer patients with/without hepatic metastases. Aim: To investigate whether whole-liver CT texture analysis can also predict the development of colorectal liver metastases. Material and methods: Retrospective multicentre study (n = 165). Three subgroups were assessed: patients [A] without metastases (n = 57), [B] with synchronous metastases (n = 54) and [C] who developed metastases within ≤24 months (n = 54). Whole-liver texture analysis was performed on primary staging CT. Mean grey-level intensity, entropy and uniformity were derived with different filters (σ0.5–2.5). Univariable logistic regression (group A vs. B) identified potentially predictive parameters, which were tested in multivariable analyses to predict development of metastases (group A vs. C), including subgroup analyses for early (≤6 months), intermediate (7–12 months) and late (13–24 months) metastases. Results: Univariable analysis identified uniformity (σ0.5), sex, tumour site, nodal stage and carcinoembryonic antigen as potential predictors. Uniformity remained a significant predictor in multivariable analysis to predict early metastases (OR 0.56). None of the parameters could predict intermediate/late metastases. Conclusions: Whole-liver CT-texture analysis has potential to predict patients at risk of developing early liver metastases ≤6 months, but is not robust enough to identify patients at risk of developing metastases at later stage.
[en] In this paper we have compared two famous methods in texture classification to solve the problem of recognition and classification of defects occurring in a textile manufacture. We have compared local binary patterns method with co-occurrence matrix. The classifier used is the support vector machines (SVM). The system has been tested using TILDA database. The results obtained are interesting and show that LBP is a good method for the problems of recognition and classifcation defects, it gives a good running time especially for the real time applications.
[en] A new plasma jet (PJ-100) plasma spraying torch with a fixed minimal arc length was tested and the basic working parameters were measured and evaluated. The velocity of the plasma exiting both the cylindrical and the conical anode nozzles was assessed by measuring the thrust generated by the plasma jet and by photographing the translation of plasma clouds (parts with different brightnesses) in the last third of the length of the plasma plume. The basic characteristics of the argon/hydrogen plasma jets (enthalpy, mean temperature, mean plasma velocity and effective exhaust thrust velocity) were determined for different working regimes, for both the cylindrical and the conical nozzles. The thermal efficiency of the new plasma torch is between 70% and 74% for the plasma generation power up to 90 kW. The plasma plume generated in the cylindrical nozzle has a homogeneous radial temperature (and velocity) distribution with a full laminar flow.