Method For Size Characterization Research Articles

Limit load prediction analysis of X80 pipeline containing corrosion in mountainous landslide section

Currently in China X80 pipeline laying mostly concentrated in mountainous areas, oil and gas pipeline transmission distance, through the complex and diverse terrain, the pipeline by the buried environment will not only appear corrosion defects, but also by the impact of soil slippage to reduce the pressure-bearing capacity of the pipeline, resulting in pipeline perforation, broken, leading to oil and gas leakage accidents, further leading to fire, explosion and environmental pollution and other major safety accidents. In view of the important strategic position of oil and gas pipelines and the severity of accident hazards, it is important to study the ultimate bearing capacity of buried corroded pipelines. With this purpose, this paper analyzes the existing pipe-soil coupling theories based on the large-scale test in the field, optimizes the nonlinear contact model, and establishes a nonlinear corroded pipe-soil interaction model and verifies its accuracy. By using the existing soil load application function and coupling the actual soil slip data, the inhomogeneous movement of soil slip is realized. Based on the existing corrosion size characterization methods, the effect of corrosion size on the ultimate load carrying capacity of intact pipes was further verified by means of a combination of FEA and experiments. Specifically, the effects of soil slip under no load and internal pressure coupled conditions on the mechanical behavior of corroded pipelines are compared and analyzed; the necessity of considering soil slip is clarified; the influencing factors such as pipe corrosion size, operating internal pressure, and corrosion position are analyzed to reveal the failure mechanism of buried corroded pipelines in mountainous areas. By using the pipe displacement at the strain failure as the evaluation index, and using the dimensional analysis method to reveal the relationship between each influencing factor and the ultimate load, the ultimate load prediction formula for corroded pipelines under soil slip actions is derived. The research results can help evaluate the safety condition of existing operating pipelines, release early warning for the structure safety of pipelines, and provide guidance for the safety protection of pipelines in mountainous areas.

Preparation of Ultrafine Nitroguanidine by One-Step Crystallization in an Impinging Stream-Rotating Packed Bed

To solve the problems of the traditional production process of ultrafine nitroguanidine (NQ), such as a long process and easy pollution caused by recrystallization, the ultrafine NQ (2–6 μm) was prepared by the one-step crystallization in an impinging stream-rotating packed bed (IS-RPB). The influence of operation parameters on the size of the NQ crystal was discussed through various particle size characterization methods. Results show that the size of ultrafine NQ prepared in the IS-RPB was 2.0–3.0 μm, which was smaller than that of market products and conformed to the military standard. Simultaneously, the crystal morphology tended to reduce the length, meeting the target requirement of “shorter and thicker” high-end products. The role of high dispersion and strong mixing in the IS-RPB was the key to continuous and one-step nucleation and crystallization of NQ. One-step crystallization in the IS-RPB is a push flow operation process, where abundant accumulation of the raw material will be avoided effectively, and the safety of energetic material processing will be enhanced greatly. Ultrafine NQ can be prepared without recrystallization, which greatly reduces the energy consumption and the pollution of organic impurities to the product and the environment, providing a new way for the continuous production of ultrafine NQ.

Grain size characterization method of dual-phase titanium alloys with complex microstructure based on laser ultrasonic

The microstructure of dual-phase titanium alloy is more complex than that of single-phase metallic materials, and its mechanical properties have a larger adjustment range. Online detection of the grain size of dual-phase titanium alloys is meaningful for improving product quality and controlling production costs. In this study, samples with different microstructures were obtained by heat treatment. Then, the attenuation coefficients of the ultrasonic wave were calculated by the experimental signals. Combined with metallographic images, the relationship between the attenuation coefficient and microstructure was analyzed. Finally, characterization models of the average grain size of dual-phase titanium alloys based on ultrasonic attenuation were established. In the Rayleigh region, the attenuation coefficient is proportional to the third power of the grain size and the fourth power of the frequency. This study can provide a reference for the online detection of grain size of metallic materials with complex microstructure based on laser ultrasonic technology.

Grain size characterization of Ti-6Al-4V titanium alloy based on laser ultrasonic random forest regression.

In this paper, a random forest regression (RFR) rain size characterization method based on a laser ultrasound technique is investigated to predict the grain size of titanium alloy (Ti-6Al-4V). The longitudinal wave velocity of the ultrasound signal and the attenuation coefficient at different frequencies are used as the input and the grain size is used as the output. An RFR algorithm was used to develop a grain size prediction model. Meanwhile, the grain size calculation model based on conventional scattering attenuation was established by calibrating the n value in the classical scattering theory using the attenuation coefficients at different frequencies of ultrasonic signals. The results show that the RFR algorithm is feasible for the grain size characterization of titanium alloys.

Evaluation of coal screening performance by spatial image reconstruction method

Screening is an indispensable unit operation for the large-scale separation of solid materials, and is widely used in industrial processes such as mining, construction, chemical production, and other operations. In the coal preparation process, evaluation of the screening performance involves the measurement of particle size distribution of products, which has traditionally been carried out using a manual screening method (SM), a relatively time-consuming process that does not provide timely feedback for adjusting operational parameters. Herein, a method for obtaining particle size via spatial image reconstruction was proposed, and an equivalent diameter method was used to characterize the particle size. The absolute error of the method was found to be <0.1 mm, demonstrating high precision. The accuracy of the particle size characterization method was 96.19 %, which is considered reliable. When applied to the evaluation of industrial screening equipment, the spatial image reconstruction method showed satisfactory results, achieving screening efficiency and total mismatched materials values differing by only 0.71 % and 0.34 %, respectively, from those obtained by SM.

3D Printed Instrument for Taylor Dispersion Analysis with Two-Point Laser-Induced Fluorescence Detection.

Precisely controlling the size of engineered biomolecules and pharmaceutical compounds is often critical to their function. Standard methods for size characterization, such as dynamic light scattering or size exclusion chromatography, can be sample intensive and may not provide the sensitivity needed for mass- or concentration-limited biological systems. Taylor dispersion analysis (TDA) is a proven analytical method for direct, calibration-free size determination which utilizes only nL-pL sample volumes. In TDA, diffusion coefficients, which are mathematically transformed to hydrodynamic radii, are determined by characterizing band broadening of an analyte under well-controlled laminar flow conditions. Here, we describe the design and development of a 3D printed instrument for TDA, which is the first such instrument to offer dual-point laser-induced fluorescence (LIF) detection. The instrument utilized a fully 3D printed eductor as a vacuum source for precise and stable pressure-driven flow within a capillary, evidenced by a linear response in generated static pressure to applied gas pressure (R2 = 0.997) and a 30-fold improvement in stability of static pressure (0.05% RSD) as compared to a standard mechanical pump (1.53%). Design aspects of the LIF detection system were optimized to maximize S/N for excitation and emission optical axes, and high sensitivity was achieved as evidenced by an 80 pM limit of detection for the protein R-Phycoerythrin and low nM limits of detection for three additional fluorophores. The utility of the instrument was demonstrated via sizing of R-Phycoerythrin at pM concentrations.

Determination of Particle Size, Core and Shell Size Distributions of Core–Shell Particles by Analytical Ultracentrifugation

AbstractIn core–shell nanoparticle analysis, the determination of size distributions of the different particle parts is often complicated, especially in liquid media. Density matching is introduced as a method for analyzing core–shell nanoparticles using Analytical Ultracentrifugation (AUC), making it possible to obtain the core size distribution in liquid dispersions. For this approach, the density of the dispersion is adjusted to the density of the shell. Oil filled nanocapsules are utilized with component densities of around 1 g mL−1 to demonstrate this technique. The shell size distribution is calculated supposing the particle size distribution as a convolution of the shell‐ and core size distributions. Finally, the distributions of core size, shell thickness, particle size, and particle density and thus particle composition are obtained. To clarify the effect of swelling, AUC measurements are combined with further size characterization methods like Particle Tracking Microscopy and Dynamic Light Scattering.

Size-controlled flow synthesis of metal-organic frameworks crystals monitored by in-situ ultraviolet–visible absorption spectroscopy

Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications, however, is facing challenges due to lack of in-situ method for size-characterization in fluidic environment. We present that ultraviolet-visible (UV–vis) absorption spectroscopy can be integrated into a flow-synthesis system which was produced by femtosecond laser micromachining. The shift of the absorption peak position of the ex-situ and in-situ UV–vis spectra correlates to variation of size of porous metal-organic frameworks crystals. ZIF-67 crystals with a size in the range from 200 nm to 1025 nm are fabricated with the assistance of tri-ethylamine under monitoring of in-situ UV–vis spectra. The ZIF-67 crystals are converted into nanoporous carbons particles with controlled sizes. These materials show size-dependent performance in Na-ion battery and size-independent performance in metal/H2O seawater battery.

Comparative analysis of shale pore size characterization methods

The pore size distribution of four shale samples were characterized by and compared between CO2 adsorption, N2 adsorption, MIP and NMR. The results show that CO2 adsorption has an absolute advantage for characterization of pores smaller than 2 nm. N2 adsorption is reliable for 2–50 nm pore characterization and is superior to NMR in the 2–10 nm range. NMR has advantages for 10–100 nm pore characterization, and MIP has advantages for characterization of pores larger than 100 nm. NMR offers the widest range of observations, and order of the maximum resolution of these methods is CO2 adsorption > N2 adsorption > NMR > MIP.

Image segmentation-based volume approximation-volume as a factor in the clinical management of osteolytic jaw lesions.

Size characterization of osteolytic jaw lesions (OJL), in particular of neoplastic nature, is heterogeneously performed and lacks standardization in the medical literature and clinical practice. An OJL's volume holds promise as a surrogate for treatment response and prognosis. We comparatively evaluate various methods for size characterization of odontogenic OJLs. We retrospectively performed semiautomatic image segmentation of CBCT data sets for volume approximation of neoplastic (51) and non-neoplastic odontogenic OJLs (100). We assessed the three greatest orthogonal diameters and calculated the volume using the cuboid- and ellipsoid-formula. Image segmentation was carried out using ITK-SNAP. Image segmentation-based volume approximation served as reference. Intra- and inter-rater variability were evaluated at hand of Bland-Altman-Analysis and dice similarity coefficient (DSC). Concerning the intrarater variability, we found the DSC to be highest for image segmentation-based volume approximation, simultaneously showing the tightest limits of agreement and greatest reliability. The cuboid formula showed consistent overestimation of the lesion's volume with a percent mean difference of -52 % (upper and lower limits of agreement +8.57 % and -112.63%, respectively). In mean, the ellipsoid formula underestimated the lesion's volume by 10.1% (upper and lower limits of agreement +76.8% and -56.6%, respectively). Inter rater variability was higher for formula-based volume approximation. Volume and multilocularity (p = 0.001) correlate with aggressiveness and growth potential. Segmentation-based volume approximation holds great promise for patient individualized treatment planning and clinical management. The data suggest that maximum tumour diameter-based size characterization, especially the cuboid-formula and the maximum diameter alone, should not be recommended.

Determination of the size distribution of non-spherical nanoparticles by electric birefringence-based methods

The in situ determination of the size distribution of dispersed non-spherical nanoparticles is an essential characterization tool for the investigation and use of colloidal suspensions. In this work, we test a size characterization method based on the measurement of the transient behaviour of the birefringence induced in the dispersions by pulsed electric fields. The specific shape of such relaxations depends on the distribution of the rotational diffusion coefficient of the suspended particles. We analyse the measured transient birefringence with three approaches: the stretched-exponential, Watson-Jennings, and multi-exponential methods. These are applied to six different types of rod-like and planar particles: PTFE rods, goethite needles, single- and double-walled carbon nanotubes, sodium montmorillonite particles and gibbsite platelets. The results are compared to electron microscopy and dynamic light scattering measurements. The methods here considered provide good or excellent results in all cases, proving that the analysis of the transient birefringence is a powerful tool to obtain complete size distributions of non-spherical particles in suspension.

Characterization of mean grain size of interstitial-free steel based on laser ultrasonic

This paper investigated a novel mean grain size characterization method via laser ultrasonic. The IF steel samples with different grain sizes were conducted with different heat treatments, respectively, and each sample was observed by EBSD and tested by laser ultrasonic. The laser ultrasonic signal was decomposed by wavelet packet transform and sorted using correlation analysis. Then the optimal components were selected to reconstruct the new signal and obtain the energy attenuation coefficient. Finally, the novel mean grain size prediction model was established according to the Rayleigh scattering and absorption attenuation. These results show that the maximum prediction error could be reduced to 5.74% by our new method, which is more precise than the traditionally used methods. Our new method improves the mean grain size evaluation to a more precise level. In addition, compared with the conventional mean grain size acquisition methods, the laser ultrasonic method has the advantages of non-contact and high efficiency, and it is a nondestructive testing method which could be used in online testing.

Size Characterization of Glutathione-Protected Gold Nanoclusters in the Solid, Liquid and Gas Phases

Monolayer-protected metal nanoclusters belonging to the size regime between two and a few hundred atoms represent unique building blocks for new materials. Because of the extremely tiny size of such clusters (smaller than ∼3 nm in diameter) and the stabilizing layer which varies in size and composition, traditional techniques used for characterizing the size of large metal nanoparticles are not very reliable. In this work, we compare solid, liquid and gas phase size characterization methods for selected glutathione- (SG-) protected gold clusters (namely Au15(SG)13, Au18(SG)14, and Au25(SG)18). We also investigate the effect of nanocluster ion-pairing with bulky counterions on their size characterization. We show that X-ray powder diffraction, ion mobility mass spectrometry, and time-resolved fluorescence anisotropy can be a useful addition to tools available for ultrasmall nanoparticle characterization.

Determination of lateral block size and mosaicity of crystals using X‐ray diffraction from the edge of the sample

In this paper a novel lateral block size characterization method based on X‐ray diffractometry (XRD) is presented. The developed method based on scans of plans perpendicular to the surface visible from the edge of the sample and subconsequent numerical analysis based on Scherrer equation. In presented investigations as a reference sample bulk GaN substrate fabricated by AMMONO Ltd. was used. The GaN layers deposited on sapphire substrate were investigated as a case of study. Moreover, a method of analyzing the magnitude of the tilt and twist mosaicity based on the scans of rocking curves and reciprocal lattice maps (RLM) from the edge of sample is presented. As an example for this methodology highly mosaicited SiC crystal was used. Presented approach allows to directly determine the value of the angular deviation of mosaicity in a direction perpendicular and parallel to the sample surface.

Material grain size characterization method based on energy attenuation coefficient spectrum and support vector regression

A grain size characterization method based on energy attenuation coefficient spectrum and support vector regression (SVR) is proposed. First, the spectra of the first and second back-wall echoes are cut into several frequency bands to calculate the energy attenuation coefficient spectrum. Second, the frequency band that is sensitive to grain size variation is determined. Finally, a statistical model between the energy attenuation coefficient in the sensitive frequency band and average grain size is established through SVR. Experimental verification is conducted on austenitic stainless steel. The average relative error of the predicted grain size is 5.65%, which is better than that of conventional methods.

Liquid-phase syntheses of cobalt ferrite nanoparticles

The aim of the present study was to synthesize cobalt-ferrite (CoFe2O4) nanoparticles using various liquid phase methods; sol–gel route, co-precipitation process, and microemulsion technique. The effects of experimental parameters on the particle size, size distribution, morphology, and chemical composition have been studied. The anions of precursors (chloride and nitrate), the solvents (water, n-propanol, ethanol, and benzyl alcohol), the precipitating agent (ammonia, sodium carbonate, and oxalic acid), the surfactants (polydimethylsiloxane, ethyl acetate, citric acid, cethyltrimethylammonium bromide, and sodium dodecil sulfate), their concentrations, and heat treatments were varied in the experiments. The smallest particles (around 40 nm) with narrow polydispersity and spherical shape could be achieved by a simple, fast sol–gel technique in the medium of propanol and ethyl acetate. The size characterization methods have also been investigated. Small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and scanning electron microscopy (SEM) provide the comparison of methods. The SAXS data correspond with the sizes detected by SEM and differ from DLS data. The crystalline phases, morphology, and chemical composition of the particles with different shapes have been analyzed by X-ray diffraction, SEM, and energy dispersive X-ray spectrometer.

Effect of precipitation procedure and detection technique on particle size distribution of CaCO 3

The deposition of inorganic salts (“scales”) such as calcium carbonate is an important flow assurance problem during crude oil production. The knowledge of the features of the precipitated solids, mainly the particle size and morphology, is crucial to understand the nature of the solids and to avoid or reduce the effect of their deposition. For instance, the use of additives is one of the most usual procedures to mitigate this problem. Additives interact with scale-forming substances either by increasing the induction time, or by inhibiting crystal growth, changing the morphology of solids. In this work, CaCO 3 was precipitated by two different experimental methods: by mixing sodium carbonate and calcium chloride at 25 °C (method 1), and by changing the pH (method 2). Precipitated solids were analyzed by means of the following techniques: laser diffraction (LD), focused-beam reflectance measurement (FBRM), scanning electron microscopy (SEM), and X-ray diffraction (XRD), in order to select a method for the determination of particle size of solids similar to scales, in order to study these deposits at the beginning of their formation and to evaluate the effect of additives in the scales particle size. Results were compared to those of scale deposits extracted from crude oil pipelines. SEM and XRD characterization showed that both the precipitation methods lead to calcium carbonate as a mixture of calcite, aragonite and vaterite, with rhombohedral morphology for method 1 and spherical for method 2. The effects of temperature, kinetics and Mg 2+ presence in the morphology of CaCO 3 were evaluated. Thus, the solids obtained by static bottle test and real scales are mainly formed by long needle-shaped aragonite. The comparison of the several particle size characterization methods determinates that an LD is a fast and sensitive technique for spherical and non-spherical solids, and it is a convenient technique for the analysis of scales extracted from oil pipelines.

A Critical Review of Methods for Size Characterization of Non-Particulate Protein Aggregates

Although size exclusion chromatography (SEC) has been, and will continue to be, the primary analytical tool for characterization of the content and size distribution of non-particulate aggregates in protein pharmaceuticals, regulatory concerns are driving increased use of alternative and complementary methods such as analytical ultracentrifugation and light scattering techniques. This review will highlight and critically review the capabilities, advantages, and drawbacks of SEC, analytical ultracentrifugation, and light scattering methods for characterizing aggregates with sizes below about 0.3 microns. The physical principles of the biophysical methods are briefly described and examples of data for real samples and how that data is interpreted are given to help clarify capabilities and weaknesses.

Successive Refinement for Hypothesis Testing and Lossless One-Helper Problem

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> We investigate two closely related successive refinement (SR) coding problems: 1) In the hypothesis testing (HT) problem, bivariate hypothesis <emphasis><formula formulatype="inline"><tex>$H_{0}:P_{XY}$</tex></formula></emphasis> against <emphasis><formula formulatype="inline"><tex>$H_{1}: P_{X}P_{Y}$</tex></formula></emphasis>, i.e., test against independence is considered. One remote sensor collects data stream <emphasis><formula formulatype="inline"><tex>$X$</tex></formula></emphasis> and sends summary information, constrained by SR coding rates, to a decision center which observes data stream <emphasis><formula formulatype="inline"><tex>$Y$</tex> </formula></emphasis> directly. 2) In the one-helper (OH) problem, <emphasis><formula formulatype="inline"><tex>$X$</tex></formula></emphasis> and <emphasis><formula formulatype="inline"><tex>$Y$</tex></formula></emphasis> are encoded separately and the receiver seeks to reconstruct <emphasis><formula formulatype="inline"> <tex>$Y$</tex></formula></emphasis> losslessly. Multiple levels of coding rates are allowed at the two sensors, and the transmissions are performed in an SR manner. We show that the SR-HT rate-error-exponent region and the SR-OH rate region can be reduced to essentially the same entropy characterization form. Single-letter solutions are thus provided in a unified fashion, and the connection between them is discussed. These problems are also related to the information bottleneck (IB) problem, and through this connection we provide a straightforward operational meaning for the IB method. Connection to the pattern recognition problem, the notion of successive refinability, and two specific sources are also discussed. A strong converse for the SR-HT problem is proved by generalizing the image size characterization method, which shows the optimal type-two error exponents under constant type-one error constraints are independent of the exact values of those constants. </para>

A hybrid method for size characterization of coarse subsurface fluvial sediments

AbstractThis paper introduces and evaluates a novel method for ascertaining the grain‐size distribution of subsurface sediments that involves profoundly less sampling effort than standard methods. It is based on hybrid sampling principles previously applied to the construction of synthetic surface grain‐size distributions. The method is developed from an empirical demonstration of the approximate similarity of surface and subsurface grain‐size distributions when compared over a common range of sizes. Subsurface hybrid models are found to provide good facsimiles of grain‐size distributions defined using standard criteria and to yield distribution percentiles with millimetre accuracy. The technique is presented as an expedient alternative to standard methods for large, perennial gravel‐bed rivers. As this is a new technique, prudent application is advised in lieu of further investigation. Copyright © 2004 John Wiley &amp; Sons, Ltd.