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Wax crystallization and deposition is a major flow assurance problem in production and transportation of waxy crude oil. Conventional flow improvers are mainly high molecular weight synthetic polymers, many of which are eco-toxic. Bio-based flow improvers derived from natural products are promising as inexpensive, eco-friendly alternatives to existing products. In this study, natural cashew nut shell liquid (CNSL) extracted from waste shells ofAnacardium occidentalewas esterified with polyethylene glycol (PEG). CNSL derivative reduced the pour point of waxy crude oil by 12 °C at 1000 ppm. The effects of CNSL derivatives on wax crystal morphology and micro-structure were studied by cross-polarized microscopy. Micrographs were processed and analyzed with ImageJ software. Addition of CNSL derivatives to oil resulted in changes in wax crystal morphology and micro-structure evidenced by a reduction in average crystal Feret diameter and aspect ratio and increase in boundary fractal dimension, indicative of formation of increasing number of smaller, rounder crystals. Effect of the additives on flow properties of the waxy oil was determined using a co-axial cylinder rotational viscometer. Dynamic viscosity of oil at shear rate of 17 s−1was reduced by 79.7–90.5%. CNSL-PEG esters show good prospects as low-cost additives for production, storage and pipeline transportation of waxy crude oil.

In this study, several artificial neural network (ANN) models were developed with the help of microstructural characteristics to predict uniaxial compressive strength (UCS) and elastic modulus (E) of migmatites. To this end, 51 migmatite samples were prepared and for each sample some microstructural characteristics along with UCS and E were determined. A semi-automatic technique was implemented to quantify twenty microstructural characteristics including mineral size (area, perimeter, equivalent circular diameter, minimum Feret diameter, maximum Feret diameter), mineral shape (aspect ratio, orientation, compactness, roundness, rectangularity, solidity, convexity, concavity, form factor), fabric coefficients (index of interlocking, index of grain size homogeneity), mineral contents (quartz content, feldspar content), and mineralogical indices (saturation index, and coloration index) based on digital imaging of representative parts of thin sections of samples. Area, orientation, concavity, index of interlocking, feldspar content and saturation index were chosen as inputs of the prediction models. Here, 6, 10 and 10 ANN models were developed with 5, 4 and 3 inputs, respectively, using these microstructural characteristics. Bayesian regularization was employed for training the models to improve the generalization capacity of the models. From these models, the model with orientation, index of interlocking and feldspar content as inputs was selected for producing prediction charts. For this model, mean squared error and correlation coefficient were obtained as 0.0148 and 0.854 for training data, and 0.0143 and 0.860 for test data, respectively. The proposed models and prediction charts in this study can show high prediction capability, given that they are used for similar types of rocks.

The objectives of this study were to explore the effects of bulking agent and nutrients on the pore characteristics, remediation efficiency, and biotoxicity of petroleum hydrocarbon-contaminated soil. Furthermore, the correlation among the three characteristic indices was studied. Three pilot-scale biopiles were constructed to treat aged petroleum-contaminated soil. Micro-CT was applied to obtain the pore characteristics of piles. The results showed that the addition of bulking agent had a positive effect on the pore development of the biopile. The porosity of the pile was increased from 0.33 to 3.32% of the control pile to 4.41 to 26.93%, and the addition of bulking agent showed a significant positive effect on the Feret diameter. However, the addition of nutrients had no significant effect on the porosity and Feret diameter. Besides, the total petroleum hydrocarbon removal rate of bulking agent pile (36.82–49.18%) was significantly higher than that of nutrient piles (20.07–23.43%) and control piles (17.57–27.08%). The bulking agent pile had the lowest toxicity. The porosity of the pile, total petroleum hydrocarbons removal rate, and the characteristic values of biotoxicity (EC50) showed a positive correlation. Bulking agents might promote gas circulation by improving the pore structure of the biopile. And the metabolic activity of microorganisms increased as a result of the promotion of the microbial habitat. The higher biodegradation of petroleum hydrocarbons was achieved. However, the main finding of this research is that adding bulk agent to petroleum-contaminated soil significantly increases biodegradation of petroleum. This may be inapplicable to other soils with a different clay content or porosity.

Wax formation creates flow assurance problems in the production and transportation of waxy crude oil. Flow improvers are added to waxy crude in order to reduce handling cost. Bio-based flow improvers derived from cheap renewable resources are attractive as cost-effective, eco-friendly alternatives to the conventional additives. Natural cashew nut shell liquid extracted from waste biomass (Anacardium occidentale shells) was derivatized and applied as flow improver for waxy crude oil. Effect of the additive on wax formation in crude oil was studied by cross-polarized microscopy, while the change in oil flow properties was evaluated using a rotational coaxial cylinder viscometer. Micrographs of the waxy crude were processed and analyzed with image J software. The microscopic properties of the wax crystals were characterized using Feret diameter, crystal area, aspect ratio, circularity, solidity and boundary fractal dimension. The pour point of doped crude oil was depressed by − 18 °C and the wax area fraction reduced by 40% due to wax inhibitive effect of the additive. The presence of the additive resulted in evolution of smaller, rounder and more regular wax crystals with smoother and more even surfaces indicated by reduction in the Feret diameter, aspect ratio and boundary fractal dimension of wax crystals in doped oil, and an increase in crystal circularity and solidity. The shear stress and viscosity of doped oil were reduced by 86.8% and 85.0%, respectively. The flow improvement effect of the CNSL derivative is linked to its effect on morphology and microstructure of wax crystals in the crude oil.

Background Spots and coloring patterns evaluated quantitatively can be used to discriminate and identify possible cryptic species. Species included in the Triatoma dimidiata (Reduviidae: Triatominae) complex are major disease vectors of Chagas disease. Phylogenetic studies have defined three haplogroups for Mexico and part of Central America. We report here our evaluation of the possibility of correctly discriminating these three T. dimidiata haplogroups using the pattern of the dorsal spots. Methods Digital images of the dorsal region of individuals from the three haplogroups were used. Image processing was used to extract primary and secondary variables characterizing the dorsal spot pattern. Statistical analysis of the variables included descriptive statistics, non-parametric Kruskal–Wallis tests, discriminant function analysis (DFA) and a neural classification network. Results A distinctive spot pattern was found for each haplogroup. The most differentiated pattern was presented by haplogroup 2, which was characterized by its notably larger central spots. Haplogroups 1 and 3 were more similar to each other, but there were consistent differences in the shape and orientation of the spots. Significant differences were found among haplogroups in almost all of the variables analyzed, with the largest differences seen for relative spot area, mean relative area of central spots, central spots Feret diameter and lateral spots Feret diameter and aspect ratio. Both the DFA and the neural network had correct discrimination values of > 90%. Conclusions Based on the results of this analysis, we conclude that the spot pattern can be reliably used to discriminate among the three haplogroups of T. dimidiata in Mexico, and possibly among triatomine species. Graphical Abstract

Objective: The complexity of chromatin (i.e., irregular geometry and distribution) is one of the important factors considered in the cytological diagnosis of cancer. Fractal analysis with Kirsch edge detection is a known technique to detect irregular geometry and distribution in an image. We examined the outer cutoff value for the box-counting (BC) method for fractal analysis of the complexity of chromatin using Kirsch edge detection. Materials: The following images were used for the analysis: (1) image of the nucleus for Kirsch edge detection measuring 97 × 122 pix (10.7 × 13.4 μm) with a Feret diameter of chromatin mesh (n = 50) measuring 17.3 ± 1.8 pix (1.9 ± 0.5 μm) and chromatin network distance (n = 50) measuring 4.4 ± 1.6 pix (0.49 ± 0.18 μm), and (2) sample images for Kirsch edge detection with varying diameters (10.4, 15.9, and 18.1 μm) and network width of 0.4 μm. Methods: Three types of bias that can affect the outcomes of fractal analysis in cytological diagnosis were defined. (1) Nuclear position bias: images of 9 different positions generated by shifting the original position of the nucleus in the middle of a 256 × 256 pix (28.1 μm) square frame in 8 compass directions. (2) Nuclear rotation bias: images of 8 different rotations obtained by rotating the original position of the nucleus in 45° increments (0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°). (3) Nuclear size bias: images of varying size (diameter: 190 pix [10.4 μm], 290 pix [15.9 μm], and 330 pix [18.1 μm]) with the same mesh pattern (network width: 8 pix [0.4 μm]) within a 512 × 512 pix square. Different outer cutoff values for the BC method (256, 128, 64, 32, 16, and 8 pix) were applied for each bias to assess the fractal dimension and to compare the coefficient of variation (CV). Results: The BC method with the outer cutoff value of 32 pix resulted in the least variation of fractal dimension. Specifically, with the cutoff value of 32 pix, the CV of nuclear position bias, nuclear rotation bias, and nuclear size bias were p = 0.19). Our study suggests that the BC method with the outer cutoff value of 32 pix is suitable for the analysis of the complexity of chromatin with chromatin mesh.

Plates with leading-edge tubercles experience beneficially more gradual aerodynamics stalling when entering the post-stall regime. Little is known, however, about the corresponding aquatic flow responses when these tubercles-furnished plates are subjected to the maximal angle of attack, with the flow direction perpendicular to their planar area. Hence, this study presents numerically, by means of the flow behavior solver ANSYS, the flow responses alteration in terms of the geometrical effects of tubercles on plates through changes in amplitudes (5 mm, 10 mm, 15 mm) and wavelengths (50 mm, 100 mm, 150 mm) under the maximal angle of attack in comparison to a control case, i.e., without tubercles. Additional to the commonly examined flow velocity and pressure, characteristics such as wake (area, reattachment length, flow recirculation intensity) and newly defined downstream vortical parameters (area, perimeter, and Feret diameters) for the vortex region have been proposed and assessed. It is found that the drag increases with the tubercle wavelength but corresponds inversely with the tubercle amplitude. By correlating with the best beneficial velocity and pressure profiles, it has been characterized that the optimally performing plate is the one that generates the greatest flow recirculation intensity, wake area, and reattachment length, corresponding to the capability to produce also the highest vortical area, perimeter, and major Feret diameter. Compared to the control case, all plates with tubercles alter beneficially these flow behaviors. In conclusion, plates with tubercles contribute favorably to the flow behaviors under the maximal angle of attack compared to the control case while the newly proposed downstream parameters could serve capably as alternatives in corroborating the flow physics description in future studies.

This study aimed to investigate the geometry distinction of the pores formed by brittle minerals in shale oil reservoir and dig out its significance in hydrocarbon migration and exploitation. 14050 pores related to brittle minerals in typical shale oil reservoir samples are selected as the research objects, high-resolution field emission scanning electron microscopy (FE-SEM), imbibition test, Nuclear Magnetic Resonance(NMR), high-resolution image technique, construction of new parameters, statistics and analysis of large numbers and other means are used to discover this issue. Results firstly show that the development of pores in the two directions (Angle between two directions is 90 degrees or approximately 90 degrees) are complementary and promote each other. Reversely, the data points begin to be scattered, which means that the development of the pore in the above two directions begins to “lose stability”, rather than promote each other all the time. This could prove that the rectangle (width, height), Legendre ellipse (major axis and major axis) and maximum and minimum Feret diameter of pores can all be used as the effective criteria for the development of pore shape related to brittle minerals. Sufficient evidences could prove that the pores related to brittle minerals contribute to oil and gas migration and oil & water imbibition. The conclusion of this study will provide an important theoretical basis for clarifying the oil occurrence mechanism of shale oil reservoir and looking for the geological and engineering dessert from the microscopic viewpoint.

A new certified reference material (CRM) for size and shape analysis of elongated nanoparticles has been developed by the European Commission’s Joint Research Centre. The CRM consists of titanium dioxide nanorods dispersed in 1-butanol, was coded ERM-FD103 and has been certified for different electron microscopy–based operationally defined measurands such as the modal and median values of the particle number-weighted distributions of the minimum and maximum Feret diameter, the maximum inscribed circle diameter, the area-equivalent circular diameter and the aspect ratio. The nanorods have nominal dimensions of 15 nm in width and 55 nm in length. Homogeneity and stability measurements were performed using transmission electron microscopy. The relative standard uncertainty for homogeneity ranged from 0.3 to 1.7%. No significant instability was detected for a shelf life of 18 months and a storage temperature of 18 °C. The certified values have been determined from the results of an interlaboratory comparison in which qualified expert laboratories participated with scanning and transmission electron microscopy. The certified values are traceable to the unit of length in the International System of Units, the metre, and the relative expanded uncertainties (confidence level of approximately 95%) range from 4 to 6%. These properties allow the CRM to be used for quality assurance and calibration of electron microscopy methods for nanoparticle size and shape analysis in ranges relevant for the implementation of EU legislation related to nanomaterials. The presented study discusses the purpose and results of the different steps that were followed to turn an industrially relevant raw titanium dioxide nanorod material into a fit-for-purpose CRM. Graphical abstract Electronic supplementary material The online version of this article (10.1007/s00216-020-02984-z) contains supplementary material, which is available to authorized users.

OBJECTIVE To develop a method for measuring the diameter of the osseous external auditory canal (OEAC) in pediatric and adult patients. STUDY DESIGN Retrospective analysis of imaging data from patients with a cholesteatoma who underwent transcanal endoscopic ear surgery (TEES) to remove the cholesteatoma by analyzing preoperative sagittal cone beam computed tomography (CBCT) images using ImageJ. METHODS Pediatric and adult patients were included who underwent TEES for a cholesteatoma between December 2011 and March 2015 and had available preoperative CBCT scans. Sagittal CT imaging data were analyzed by ImageJ to measure the maximum and minimum Feret diameters along the OEAC. The output data were then analyzed to determine the smallest maximum and smallest minimum Feret diameters for each patient. RESULTS Fifty-one patients ranging in age from 3 to 83 years old were included in this study. The smallest maximum Feret diameter ranged from 6.5 to 10.1 mm (mean: 8.0 mm) for pediatric patients (

This paper analyzes a cohort of children diagnosed with congenital strabismus independent of the deviation direction, dissociated and non-dissociated, to identify anisocoria magnitude under scotopic conditions. This disease presents changes in the white matter affecting the nerve conduction in the cortical integrator, exacerbating the reflexes controlling pupil size, producing subtle changes in the pupil dimensions that are difficult to measure using current methods. The proposed indexes estimate the degree of anisocoria using the Feret diameter and the Pattern Pupil parameter. This research presents a prospective, transversal, and experimental study carried out on 168-Mexican children aged 5-15 years from Querétaro, México, diagnosed with dissociated and non-dissociated congenital strabismus. The utilized images come from videos of each patient recorded in scotopic lighting conditions (0.3 lux). The ophthalmologist measured the Feret diameters of both pupils using the ImageJ software. 11.9% of the sample group showed “Very significant,” and “Significant” degrees of anisocoria, whereas 88.1% of the sample group had “Non-significant,” and “Few significant” degrees of anisocoria. When comparing the results with those obtained using the perimeter, and the diameter, subtle variations of anisocoria were better detected using the area criterion. ANOVA experiments allowed the following: 1) dissociated and non-dissociated congenital strabismus identification using nidp index, and 2) the comparison of the anisocoria degrees identified by the nidp and Ddmm ≥0.4 mm indexes.

Starch is the main sugar source present in staple foods. Understanding starch hydrolysis during digestion and the resulting glucose release can be important to strategically modulate starch digestion and glucose absorption. In vitro digestion methodologies are fundamental to evaluate starch hydrolysis length and rate, but the lack of uniformity between protocols prevent the comparison of results. In this context, three different Carolino rice varieties (i.e., Carolino whiteCw, Carolino brownCb and Carolino Ariete brownCAb) were submitted to the INFOGEST harmonized in vitro digestion protocol for the evaluation of starch hydrolysis and subsequent glycemic index (GI) determination, and starch granules morphological study. Samples of Carolino rice presented total starch percentages between 64.52 (for Cb) to 71.52% (for Cw) with low amylose content (16.1919.95%, varying in the following order Cb, Daniel A. Madalena acknowledge the Foundation for Science and Technology (FCT) for his fellowship (SFRH/BD/129127/2017). This work was supported by Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors would also like to thank the investment project n8 017931 – Development of rice products with low glycemic index- co-funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through Programa Operacional Competitividade e Internacionalizac¸a˜o (COMPETE 2020) (POCI-01- 0247-FEDER-017931)., info:eu-repo/semantics/publishedVersion

Tea (Camellia sinensis) has been found as an important medicinal beverage for human which is consumed all over the world. Primarily, the majority of tea is being cultivated in Asia and Africa, however it is commercially produced by more than 60 countries. Though substantial amount is produced, its processing system is still underdeveloped which leads to decrease in export opportunity as well as low monetary value. Moreover, the traditional method of tea grading and sorting is laborious, inefficient, and costly which ultimately produces the low-quality heterogeneous products. Processing and grading of tea granules after drying is very important task for maintaining quality. Computer vision (CV) applications in processing unit especially in grading and sorting of agro-products is very popular and reliable option to improve quality of produce. In this study, an attempt was taken to develop a machine vision system for quality grading of tea granules based on physical parameters of four standard tea grades namely BOP, GBOP, CD and PF. An image acquisition system with suitable illumination arrangement was developed to obtain high resolution image of tea granules. The images were analyzed to extract physical features like projected area, circularity, roundness, ferret diameter, aspect ratio and solidity. Tea granules (BOP, CD, PF and GBOP grade) were found significantly different for the textural features area, perimeter, circularity, roundness and ferret diameter. Projected area, perimeter, and feret diameter treated as a good indicator of the extracted features as the system has been able to significantly (p

Numerous technologies are available for particle analysis, such as laser diffraction, laser in-line particle size analysis, acoustic attenuation spectroscopy etc. However, in many situations, particle size analysis needs only to be conducted in single-type research, negating the purchase of high cost equipment. Microscopy assisted photography can be used followed by the analysis of the photo in ImageJ program in this case. It has been known seaweeds possess a high nutritional profile and can partially replace some ingredients such as salt. In represented method we describe an analytical tool for food particle size diameter analysis and probability distribution validated using four different seaweed separates (2360 to 355 µm mesh sizes). This method is cheap and consists of an ordinary digital camera (or cell phone camera), any microscope (or cell phone lens) or digital micrometer (for large particles) and open-sourced software â ImageJ. For seaweed sample separates obtained from 212 to 180 µm sieve mesh sizes, only microscopy equipped with a digital camera was employed. This method can be applied for any other industry such as biological samples, pharmaceutical etc., with a particular any range of particles distribution depending on accuracy required and camera lens resolution.

In membrane bioreactors (MBRs), aeration is widely used for fouling mitigation. To characterize the bubbly flow in MBRs, employing a solution that properly mimics the sludge behavior is essential. Therefore, this work investigates (i) the influence of the aerator pore size on the bubbly flow in xanthan gum solution, and (ii) the effect on the bubbly flow of using water as the continuous fluid and of the absence of the membrane module, conditions sometimes employed as model systems for MBRs. A MBR with a hollow fiber membrane module and a sintered glass plate for the aeration system was studied. Image analysis of the flow was made to assess key bubble parameters: area, circularity, Feret diameter, quantity, and velocity. The bubbly flow formed in the xanthan gum solution presented a lower turbulence level, differing greatly from the one formed in water. Nevertheless, for both fluids, the aerator with smaller pores generated a higher quantity of small bubbles, indicating a larger area of contact with the membrane surface. Such bubbles presented a higher level of size reduction with the presence of the membrane module and higher stability (higher circularity under similar velocities). This suggests that smaller bubbles should present higher antifouling activity.

Computed X-ray tomography (CT), together with nuclear magnetic resonance spectroscopy, pulse- and pressure-decay permeability methods, is a source of comprehensive information about the geometrical parameters of the pore space. Geological material consists of 31 samples of tight, gas-bearing, clastic rocks from different wells and formations. The purpose was to parametrize in detail the pore structure, revealing the relationships between the various parameters and estimating the equation for assessing the fluid flow ability of analyzed tight rocks. Following parameters were taken into consideration in the pore space characterization: thickness mean, equivalent diameter, anisotropy, elongation, sphericity, Feret diameter, Feret coefficient, Feret shape; shape factors: 2nd circularity coefficient, Malinowska coefficient and Danielsson coefficient; as well as parameters from 3D skeleton analysis: junctions, branches, coordination number. It was captured the dependence of logarithmic T2 mean from NMR on junction count from CT, as well as T2 cutoff from NMR on elongation from CT for the all samples. Logarithm of absolute permeability was estimated based on multiple linear regression analysis using only geometrical parameters from X-ray nanotomography, which is a benefit in the times of coring material decrease.

This research reports the comparison study of manual (digital vernier caliper, DVC) method and application of computer vision system (CVS) for evaluation of size attributes (length, width and thickness) of two mango cultivars (Chausa and Dashehari). The color RGB (red, green and blue) camera was used in CVS for capturing of required profile image of fruit. The profile image was then processed and developed algorithms for image analysis and extraction of fruit’s quality attributes. Various morphological features such as area, perimeter, Max Feret diameter (MFD), hydraulic radius, Waddel disk diameter (WDD), elongation factor, compactness factor, Heywood circulatory factor and type factor of both cultivars were also evaluated using developed algorithms and attempted to describe the morphology of the outline and shape of the biological object. Area, perimeter, Max Feret diameter and Waddel disk diameter, further, correlated with the weight and volume of fruit. Various multilinear regression (MLR) models were developed for determining weight and volume of mango fruit of both cultivars using dimensional characteristics (length, width and thickness) of mango fruit evaluated by CVS. The major diameter (single variable) and all three (major, intermediate and minor) diameter (multiple variables)-based models were identified as the best models. Similarly, CVS has yielded above 97.9%, 93.5% and 92.5% accuracy in estimating mango fruits major, intermediate and minor diameters of both cultivars.

Our understanding of the developmental changes that occur during top leader elongation in gymnosperms lags behind that in angiosperms. We developed a semiquantitative method for determining epidermal cell size, by measuring the Feret diameter after cell wall staining of stem epidermal peels. This method allowed a large number of cells to be measured at various locations in the top leader of the Christmas tree Abies nordmanniana. Further, we have identified the growth rate of individual sections of the top leader, and the relationship between cell length and needle arrangement throughout the top leader. At bud break, all stem units begin to elongate simultaneously, but growth ceases from the base upwards during top leader elongation. Long top leaders were characterized by having up to three times as long cells at the base compared to short top leaders, whereas the cell lengths were similar in the apical region independent of the given plant growth capacity. In the basal sector, the level of auxin was much higher, whereas the levels of cytokinins were lower than in the apical sector, causing the auxin/cytokinin ratio to change from about 3 in the apical sector to more than 20 in the basal part. The Fibonacci number changed in the apical sector due to an increased cell number in the stem units and therefore longer distance between the needles. We conclude that the general growth pattern during top leader elongation in A. nordmanniana is similar to angiosperms but differs at the cellular level.

The feasibility of liquid metal atomization in vacuum is studied by analysis and verified by experiment. Simultaneous tritium and heat recovery in vacuum from liquid lithium–lead (PbLi) has been previously proposed, where hot and tritium–rich PbLi is transformed into small droplets in vacuum, with the tritium then released by advection and the heat radiated away. Both mechanisms aimed to reduce the tritium permeation and membrane corrosion. The key hurdle is the atomization of liquid metal in vacuum by a large diameter nozzle. Conventional sprays function in air or other gases but not in vacuum. Therefore, an instability is applied that occurs at the velocity inflection in a parallel flow. The velocity inflection is generated by superimposing rotation on a liquid jet with a dedicated swirl nozzle. This can function in vacuum. An experiment using a low–temperature melting alloy (GaInSn) is performed in vacuum, using nozzle diameters of 0.7 mm, swirl angles 67°, and flow velocities of 3 and 5 ms−1. The instability that arises when using GaInSn at room temperature resembles that of PbLi at 400–500 °C, can be used as a proxy. The observed mean droplet Feret diameter was 0.31 mm at 3 m/s jet velocity and 0.23 mm at 5 m/s. These results support the feasibility of small droplet formation from a large diameter nozzle in vacuum. Further experiment must be performed to fully verify the droplet formation and proposed tritium and heat extraction method.

In this paper, a new kind of fly ash-based geopolymer foams was prepared by chemical foaming method. The effects of foaming agent, foam stabilizer and foaming temperature on the dry density, fluidity, compressive strength, thermal conductivity and capillary water absorption of the geopolymer foams were studied. The pore structure parameters of geopolymer foams specimens including porosity, pore size distribution, Feret diameter and average roundness, were obtained by ImagePro plus image analysis software. Moreover, the influence of pore structure parameters on the properties of geopolymer foams was analyzed. The morphology and characteristics of pore structure of the geopolymer foams were also observed by shape measurement laser microscope and scanning electron microscope. The dry densities of geopolymer foams could range from 142 kg/m3 to 1021 kg/m3 and the compressive strength could range from 3.2 MPa to 44.81 MPa. The specimens of geopolymer foams possess good pore structure at 3.5% content of H2O2 and 2.85% content of sodium dodecyl sulfate. The dry density, compressive strength and thermal conductivity have a good correlation with the pore structure parameters of geopolymer foams. From the observation of the microscopic tests, the microstructure of geopolymer foams is loose and porous. Besides, the morphology and size of typical pores could be obtained. The microstructure and morphology characteristics could be well explained the macroscopic properties of the geopolymer foams.

Bubbly flow plays an important role in industrial processes. Obtaining detailed information on the flow is, however, a challenging task. One of the key process parameters is the diameter of the bubbles, which is often determined as equivalent diameter. In this study, an automatic image analysis routine for time-resolved analysis and estimation of equivalent diameter of rising single bubbles in high-speed image sequences with high accuracy is developed using the open source software KNIME. Common estimation techniques for the equivalent diameter, e.g. based on the major/minor axes, are compared to a novel rotation algorithm, where the detected bubble segments are rotated by 180° in 1° steps, for the determination of the Feret diameter. Additionally, the elongation is measured as a morphological parameter and the centroid positions are determined. In combination with the frame rate of the image sequences the ascent rates can be calculated in form of a Bubble Tracking Velocimetry (BTV). The routine was validated using static computer generated geometrical shapes as well as precision grade solid glass spheres with diameters of 0.7–2.5 mm under dynamic (settling) conditions. High-speed image sequences were recorded and analysed with a critical statistical evaluation. It could be shown that the deviation between measured diameter and real diameter of the glass spheres is less than 1.5% when using the rotating Feret diameter algorithm. Settling velocities were determined with a maximum error of 3%. A first test of the analysing routine in a bubbly flow showed that it is unaffected by dirt, small tracer particles or internals in the viewing area, which makes a combined Particle Image Velocimetry (PIV) and Shadowgraphy analysis feasible.

In this work, teardrop micromixer and swirl micromixer were used for preparation of oil-in-water (O/W) emulsions with Tween 20 and PEG 2000 as emulsifiers (concentrations: 2 % and 4 %) at different total flow rates (20 - 280 µL/min). Stability of the prepared O/W emulsions was evaluated based on the droplet size of the dispersed phase. For determination of the droplet size, the average Feret diameter was used. Furthermore, near infrared (NIR) spectra of all prepared samples were collected. Obtained results showed that the change in the droplet size followed the same trend for both micromixers used in the experiment. At higher total flow rates, emulsification resulted in smaller values of the average Feret diameter. Values of the average Feret diameter were higher for emulsions prepared in the swirl micromixer, compared to the teardrop micromixer. Artificial Neural Network (ANNs) models, based on the recorded NIR spectra of emulsions, were developed to predict the droplet size of the dispersed phase. The obtained ANN models have high values of R2 for training, test, and validation, with small error values and show that NIR spectroscopy, in combination with ANNs, could be efficiently used for evaluation of the stability of oil-in-water emulsions.

Проведена оценка размера, формы и фракционного состава гранул ГСБ-106, полученных технологией влажного гранулирования, с использованием современного высокоскоростного анализатора изображений QicPic (Sympatec Inc., Германия)., The size, shape and size distribution of GSB-106 granules obtained by wet granulation technology was evaluated using a modern high-speed image analyzer QicPic (Sympatec Inc., GmbH)., Вопросы обеспечения качества лекарственных средств, Выпуск 2 (32) 2021, Pages 47-53

Background and objective The triply periodic minimal surface (TPMS) method effectively mimics the porous scaffold for tissue engineering with continuous topology, pore interconnections, and high surface area to volume ratio. However, the process to generate a three-dimensional (3D) mesh of porous structure from the mimicked organs is complicated for biologists and sometimes requires various software. Herein, we present the standalone program called "Scaffolder" for generating the porous topology from the user-input 3D model to the open-source community. Methods The 3D mesh of a porous scaffold was used by the proposed method and dual-marching cubes algorithm. Afterward, the mesh was sliced into the contours to examine pore sizes by Feret diameter and Gilbert–Johnson–Keerthi distance. The relationships between the program parameters (i.e., grid size, angular frequency, and iso-level) and scaffold properties (i.e., pore size, porosity, and surface area ratio) were investigated. Results The developed program can generate and evaluate a porous scaffold. The median (IQR) absolute errors in grid size of 200, 300, 400, and 500 divisions were 1.92 (0.35-3.80), 1.00 (0.18-2.22), 0.53 (0-1.37), and 0.24 (0-0.74), respectively. Spearman's correlation showed the impact of angular frequency and iso-level on the pore size, porosity, and surface area of the generated scaffold (p Conclusions This study enables researchers to rapidly design the 3D mesh of porous scaffold design, evaluate scaffold properties, and customize the implicit function for various applications, especially in tissue engineering and computational structural analysis.

Food additive E171 (titanium dioxide, TiO2) is authorized to be used as food colorant in the European Union. E171 is a particulate material, containing a fraction of nanoparticles. A major challenge for food control laboratories is the lack of harmonized, validated analytical methods for measuring the physicochemical properties of nanoparticles in food. This study proposes a generic method for the determination of the number-based size distribution of the constituent particles of E171 in food products based on transmission electron microscopy (TEM). As proof of concept, the protocol was evaluated on 20 food products containing E171 and one personal care product containing titanium dioxide. The total titanium concentration in the products measured by inductively coupled plasma - mass spectrometry (ICP-MS) ranged from 0.1 to 4.0 g/kg, corresponding to 0.2–6.7 g TiO2/kg. The required initial mass of starting product needed for TEM analysis was estimated from the ICP-MS concentration. Sample preparation included matrix digestion, a first centrifugation step to remove the remaining food matrix, sonication to reduce agglomeration, and a second centrifugation step to concentrate the sample. Descriptive TEM analysis showed that five food products, labelled to contain E171, contained smaller rutile TiO2 particles (20–40 nm) coated with mica, which are potassium aluminium silicate-based pearlescent pigments. For 14 other food products and the personal care product, the protocol resulted in a homogenous distribution of the TiO2 particles over the grid surface. In general, variation between products in the number of particles on the grids was limited; on average, 672 ± 173 particles were measured in 10 images. The median of the minimum Feret diameter distribution varied from 72 ± 7 nm to 135 ± 14 nm. The percentage of nanoparticles (minimum Feret diameter smaller than 100 nm) ranged from 23% to 82%. The corresponding mass percentages of these fractions ranged from 3% to 41%. The percentages of E171 particles smaller than 30 nm was very low (3% or less) while corresponding mass fractions were negligible. For only one food product, the TiO2 concentration was too low to apply the protocol without adaptations.

Nanoparticle gold films were deposited using femtosecond laser ablation in argon at atmospheric pressure in an arrangement where a flat Au target was irradiated through a transparent substrate in close proximity. Spatially extended films were made by rastering the target and substrate assembly together in the laser beam. Fast imaging clearly showed pronounced narrowing of the ablation plume, which can be understood in terms of laser induced multiphoton ionisation and heating of the gas near the ablation site. Deposition was possible for target-substrate separation up to 2 mm. The equivalent thickness of the nanoparticle film was controlled in the range 0.4&ndash, 28 nm by changing the target-substrate separation and the shot-to-shot spacing of ablation spot raster. The mean Feret diameter varied in the range 14&ndash, 40 nm depending on the deposition conditions, and all the films showed a surface plasmon resonance at about 525 nm, which was nearly independent of the equivalent thickness. The technique can readily be applied to other materials for the fabrication of nanoparticulate films at atmospheric pressure.

Objective The project aims to evaluate whether inhalation of particles released upon grinding of dental composites may pose a health hazard to dentists. The main objective of the study was to characterize the dust from polymer-based dental composites ground with different grain sized burs and investigate particle uptake and the potential cytotoxic effects in human bronchial cells. Methods Polymerized blocks of two dental composites, Filtek™ Z250 and Filtek™ Z500 from 3M™ ESPE, were ground with super coarse (black) and fine (red) burs inside a glass chamber. Ultrafine airborne dust concentration and particle size distribution was measured real-time during grinding with a scanning mobility particle sizer (SMPS). Filter-collected airborne particles were characterized with dynamic light scattering (DLS) and scanning electron microscopy (SEM). Human bronchial epithelial cells (HBEC-3KT) were exposed to the dusts in dose-effect experiments. Toxicity was measured with lactate dehydrogenase (LDH) assay and cell counting kit-8 (CCK8). Cellular uptake was observed with transmission electron microscopy (TEM). Results Airborne ultrafine particles showed that most particles were in the size range 15−35 nm (SMPS). SEM analysis proved that more than 80% of the particles have a minimum Feret diameter less than 1 μm. In solution (DLS), the particles have larger diameters and tend to agglomerate. Cell toxicity (LDH, CCK8) is shown after 48 h and 72 h exposure times and at the highest doses. TEM showed presence of the particles within the cell cytoplasm. Significance Prolonged and frequent exposure through inhalation may have negative health implications for dentists.

Electron tomography (ET) has been used for quantitative measurement of shape and size of objects in three dimensions (3D) for many years. However, systematic investigation of repeatability and reproducibility of ET has not been evaluated in detail. To assess the reproducibility and repeatability of a protocol for measuring size and three-dimensional (3D) shape parameters for nanoparticles (NPs) by ET, an inter-laboratory comparison (ILC) has been performed. The ILC included six laboratories and six instruments models from three instrument manufacturers following a standard measurement protocol. A technical specification describing the normative steps of the protocol is published by the International Standards Organization (ISO). Gold NPs with 30 nm nominal diameter contained within a rod-shaped carbon support were measured. The use of a rod-shaped sample support eliminated the missing wedge effect in the experimental tilt series of projected images for improved quantification. A total of 443 NPs were initially measured by NRC-NANO and then 115 out of the 443 NPs were measured by five other labs to compare measurands such as the Volume (V), maximum Feret diameter (Fmax), minimum Feret diameter (Fmin), volume-equivalent diameter (Deq) and aspect ratio (Frat) of the NPs. The results of the five labs were compared with the results obtained at NRC-NANO. The maximum disagreement in measurements of Fmin and Fmax obtained by the participating labs did not exceed 7 %. The measured Deq was between 27.5 nm and 30.3 nm in agreement with the NP manufacturer’s specification (28 nm–32 nm). In addition to the above, the influence of the missing wedge effect and beam-induced NP movement was quantified based on the differences of the results between labs.

Nano-arsenic are synthesized using Bergenia ciliata root extracts in water from arsenic trioxide. The synthesized As nanoparticles, with an average diameter of 13(1) nm, self-assemble into nanotubules with average Feret diameter of 530(20) nm. These As nanotubules/nanoparticles have direct bandgap of 2.737 eV and incorporate multiple defect-related states within the gap. The presence of weak ferromagnetism in these nanotubules/nanoparticles are attributed to the dipolar interactions amongst the charges on the defect sites. Owing to van der Waals interactions between nanotubules and smaller nanoparticles, nanotubules present surface roughness and are utilized as surface-enhanced Raman spectroscopy substrate for probing methylene blue dye with an enhancement factor $$>10^3$$ .

Colloid deposition in granular media is relevant to numerous environmental problems. Classic filtration models assume a homogeneous pore space and largely ignore colloid aggregation. However, substantial evidence exists on the ubiquity of aggregation within porous media, suggesting that deposition is enhanced by it. This work studies the deposition process in relation to aggregate size and structure. We demonstrate that aggregation is induced at typical groundwater velocities by comparing the repulsive DLVO force between particle pairs to the hydrodynamic shear force opposing it. Column experiments imaged with high-resolution X-ray computed tomography are used to measure aggregate structure and describe their morphology probability distribution and spatial distribution. Aggregate volume and surface area are found to be power-law distributed, while Feret diameter is exponentially distributed with some flow rate dependencies caused by erosion and restructuring by the fluid shear. Furthermore, size and shape of aggregates are heterogeneous in depth, where a small number of large aggregates control the concentration versus depth profile shape. The range of aggregate fractal dimensions found (2.22-2.42) implies a high potential for restructuring or breaking during transport. Shear-induced aggregation is not currently considered in macroscopic models for particle filtration, yet is critical to consider in the processes that control deposition.

BACKGROUND: Microstructure analyses are gaining interest in cancer MRI as an alternative to the conventional apparent diffusion coefficient (ADC), of which the determinants remain unclear. PURPOSE: To assess the sensitivity of parameters calculated from a double diffusion encoding (DDE) sequence to changes in a tumor's microstructure early after radiotherapy and to Compare them with ADC and histology. STUDY TYPE: Cohort study on experimental tumors. ANIMAL Model: Sixteen WAG/Rij rats grafted with one rhabdomyosarcoma fragment in each thigh. Thirty-one were imaged at days 1 and 4, of which 17 tumors received a 20 Gy radiation dose after the first imagery. FIELD STRENGTH/SEQUENCE: 3T. Diffusion-weighted imaging, DDE with flow compensated, and noncompensated measurements. ASSESSMENTS: 1) To compare, after irradiation, DDE-derived parameters (intracellular fraction, cell size, and cell density) to their histological counterparts (fraction of stained area, minimal Feret diameter, and nuclei count, respectively). 2) To compare percentage changes in DDE-derived parameters and ADC. 3) To evaluate the evolution of DDE-derived parameters describing perfusion. STATISTICAL tests: Wilcoxon rank sum test. RESULTS: 1) Intracellular fraction, cell size, and cell density were respectively lower (-24%, P < 0.001), higher (+7.5%, P < 0.001) and lower (-38%, P < 0.001) in treated tumors as compared to controls. Fraction of stained area, minimal Feret diameter, and nuclei count were respectively lower (-20%, P < 0.001), higher (+28%, P < 0.001), and lower (-34%, P < 0.001) in treated tumors. 2) The magnitude of ADC's percentage change due to irradiation (16.4%) was superior to the one of cell size (8.4%, P < 0.01) but inferior to those of intracellular fraction (35.5%, P < 0.001) and cell density (42%, P < 0.001). 3) After treatment, the magnitude of the vascular fraction's decrease was higher than the increase of flow velocity (33.3%, vs. 13.3%, P < 0.001). DATA CONCLUSION: The DDE sequence allows quantitatively monitoring the effects of radiotherapy on a tumor's microstructure, whereas ADC only reveals global changes. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 4. J. Magn. Reson. Imaging 2020;52:941-951.