Search

The industrial adoption of material extrusion of polymers (MEX/P) is hindered by the geometric quality of manufactured parts. Contact image sensors (CISs), commonly used in flatbed scanners, have been proposed as a suitable technology for layer-wise characterization of contour deviations, paving the way for the application of corrective measures. Nevertheless, despite the high resolution of CIS digital images, the accurate characterization of layer contours in MEX/P is affected by contrast patterns between the layer and the background. Conventional edge-recognition algorithms struggle to comprehensively characterize layer contours, thereby diminishing the reliability of deviation measurements. In this work, we introduce a novel approach to precisely locate contour points in the context of MEX/P based on evaluating the similarity between the grayscale pattern near a particular tentative contour point and a previously defined gradient reference pattern. Initially, contrast patterns corresponding to various contour orientations and layer-to-background distances are captured. Subsequently, contour points are identified and located in the images, with coordinate measuring machine (CMM) verification serving as a ground truth. This information is then utilized by an adaptive edge-detection algorithm (AEDA) designed to identify boundaries in manufactured layers. The proposed method has been evaluated on test targets produced through MEX/P. The results indicate that the average deviation of point position compared to that achievable with a CMM in a metrology laboratory ranges from 8.02 µm to 13.11 µm within the experimental limits. This is a substantial improvement in the reliability of contour reconstruction when compared to previous research, and it could be crucial for implementing routines for the automated detection and correction of geometric deviations in AM parts. [ABSTRACT FROM AUTHOR]

Date palm (Phoenix dactylifera L.) fruit samples belonging to the 'Mejhoul' and 'Boufeggous' cultivars were harvested at the Tamar stage and used in our experiments. Before scanning, date samples were dried using convective drying at 60 °C and infrared drying at 60 °C with a frequency of 50 Hz, and then they were scanned. The scanning trials were performed for two hundred date palm fruit in fresh, convective-dried, and infrared-dried forms of each cultivar using a flatbed scanner. The image-texture parameters of date fruit were extracted from images converted to individual color channels in RGB, Lab, XYZ, and UVS color models. The models to classify fresh and dried samples were developed based on selected image textures using machine learning algorithms belonging to the groups of Bayes, Trees, Lazy, Functions, and Meta. For both the 'Mejhoul' and 'Boufeggous' cultivars, models built using Random Forest from the group of Trees turned out to be accurate and successful. The average classification accuracy for fresh, convective-dried, and infrared-dried 'Mejhoul' reached 99.33%, whereas fresh, convective-dried, and infrared-dried samples of 'Boufeggous' were distinguished with an average accuracy of 94.33%. In the case of both cultivars and each model, the higher correctness of discrimination was between fresh and infrared-dried samples, whereas the highest number of misclassified cases occurred between fresh and convective-dried fruit. Thus, the developed procedure may be considered an innovative approach to the non-destructive assessment of drying impact on the external quality characteristics of date palm fruit. [ABSTRACT FROM AUTHOR]

The industrial adoption of material extrusion of polymers (MEX/P) is hindered by the geometric quality of manufactured parts. Contact image sensors (CISs), commonly used in flatbed scanners, have been proposed as a suitable technology for layer-wise characterization of contour deviations, paving the way for the application of corrective measures. Nevertheless, despite the high resolution of CIS digital images, the accurate characterization of layer contours in MEX/P is affected by contrast patterns between the layer and the background. Conventional edge-recognition algorithms struggle to comprehensively characterize layer contours, thereby diminishing the reliability of deviation measurements. In this work, we introduce a novel approach to precisely locate contour points in the context of MEX/P based on evaluating the similarity between the grayscale pattern near a particular tentative contour point and a previously defined gradient reference pattern. Initially, contrast patterns corresponding to various contour orientations and layer-to-background distances are captured. Subsequently, contour points are identified and located in the images, with coordinate measuring machine (CMM) verification serving as a ground truth. This information is then utilized by an adaptive edge-detection algorithm (AEDA) designed to identify boundaries in manufactured layers. The proposed method has been evaluated on test targets produced through MEX/P. The results indicate that the average deviation of point position compared to that achievable with a CMM in a metrology laboratory ranges from 8.02 µm to 13.11 µm within the experimental limits. This is a substantial improvement in the reliability of contour reconstruction when compared to previous research, and it could be crucial for implementing routines for the automated detection and correction of geometric deviations in AM parts.

Date palm (Phoenix dactylifera L.) fruit samples belonging to the ‘Mejhoul’ and ‘Boufeggous’ cultivars were harvested at the Tamar stage and used in our experiments. Before scanning, date samples were dried using convective drying at 60 °C and infrared drying at 60 °C with a frequency of 50 Hz, and then they were scanned. The scanning trials were performed for two hundred date palm fruit in fresh, convective-dried, and infrared-dried forms of each cultivar using a flatbed scanner. The image-texture parameters of date fruit were extracted from images converted to individual color channels in RGB, Lab, XYZ, and UVS color models. The models to classify fresh and dried samples were developed based on selected image textures using machine learning algorithms belonging to the groups of Bayes, Trees, Lazy, Functions, and Meta. For both the ‘Mejhoul’ and ‘Boufeggous’ cultivars, models built using Random Forest from the group of Trees turned out to be accurate and successful. The average classification accuracy for fresh, convective-dried, and infrared-dried ‘Mejhoul’ reached 99.33%, whereas fresh, convective-dried, and infrared-dried samples of ‘Boufeggous’ were distinguished with an average accuracy of 94.33%. In the case of both cultivars and each model, the higher correctness of discrimination was between fresh and infrared-dried samples, whereas the highest number of misclassified cases occurred between fresh and convective-dried fruit. Thus, the developed procedure may be considered an innovative approach to the non-destructive assessment of drying impact on the external quality characteristics of date palm fruit.

Apricot stones have high commercial value and can be used for manufacturing functional foods, cosmetic products, active carbon, and biodiesel. The optimal processing of the stones is dependent on the cultivar and there is a need for methods to sort among different cultivars (which are often mixed in processing facilities). This study investigates the effectiveness of two low-cost colour imaging systems coupled with supervised learning to develop classification models to determine the cultivar of different stones. Apricot stones of the cultivars 'Bella', 'Early Orange', 'Harcot', 'Skierniewicka Słodka', and 'Taja' were used. The RGB images were acquired using a flatbed scanner or a digital camera; and 2172 image texture features were extracted within the R, G, B; L, a, b; X, Y, Z; U, and V colour coordinates. The most influential features were determined and resulted in 103 and 89 selected features for the digital camera and the flatbed scanner, respectively. Linear and nonlinear classifiers were applied including Linear Discriminant Analysis (LDA), Decision Trees (DT), k-Nearest Neighbour (kNN), Support Vector Machines (SVM), and Naive Bayes (NB). The models resulting from the flatbed scanner and using selected features achieved an accuracy of 100% via either quadratic diagonal LDA or kNN classifiers. The models developed using images from the digital camera and all or selected features had an accuracy of up to 96.77% using the SVM classifier. This study presents novel and simple-to-implement at-line (flatbed scanner) and online (digital camera) methodologies for apricot stone sorting. The developed procedure combining colour imaging and machine learning may be used for the authentication of apricot stone cultivars and quality evaluation of apricot from sustainable production. [ABSTRACT FROM AUTHOR]

Population studies of diminutive species often present unique challenges associated with methods of identifying individuals in a manner that can be reliable and retained over long periods of time. Small snakes present even more difficulties, as many marking methods rely on the use of either invasive implantation of devices, such as passive integrated transponder (PIT) tags, or through mutilation such as branding or scale clipping. Here I present an alternative method by utilizing a flatbed scanner to obtain consistent images of sufficient quality for use in photographic identification of the Common Sharp-tailed Snake (Contia tenuis) using the unique individual pigmentation patterns on the venter of the head. Additionally, I show that HotSpotter© software consistently scored image pairs of known and assessed matches higher than between pairs of known and assessed mismatches using the flatbed scanner imagery. This method provides a repeatable, reliable, non-invasive, and non-mutilating alternative to more traditional methods of identifying individual snakes. [ABSTRACT FROM AUTHOR]

The development of computers and technology allows for the production of increasingly detailed and more accurate products, including those produced on a mass scale. This applies to wood as well as wood-based products. While scientific tools are becoming more precise and sophisticated, they only provide raw data that must be processed and analyzed. The aim of this work was to create and verify a complex, economically feasible tool that allows assessing whether the hole of a small dimension (0.5–3.0 mm) is made in the designed place. To achieve this goal, home-use flatbed scanner and free source software were utilized. The work was divided into three parts: (1) identifying the most favorable analysis parameters, (2) developing scripts and evaluating their effectiveness in marking known offset of 0.127 mm, (3) verifying the ability to distinguish groups of holes between which the difference in position differs by as much as 0.0254 mm. The developed tool does not allow for the determination of the absolute displacement of the holes, but it is characterized by high efficiency and effectiveness, allowing the comparison of groups of holes with diameters from 0.5 to 3.0 mm. It can be used to determine the influence of cutting parameters on the quality of the location of the created hole with high statistical significance. [ABSTRACT FROM AUTHOR]

The development of the first microfluidic paper-based analytical device (µPAD) for the speciation of inorganic arsenic in environmental aqueous samples as arsenite (As(III)) and arsenate (As(V)) which implements hydride generation on a paper platform is described. The newly developed µPAD has a 3D configuration and uses Au(III) chloride as the detection reagent. Sodium borohydride is used to generate arsine in the device's sample zone by reducing As(III) in the presence of hydrochloric acid or both As(III) and As(V) (total inorganic As) in the presence of sulfuric acid. Arsine then diffuses across a hydrophobic porous polytetrafluoroethylene membrane into the device's detection zone where it reduces Au(III) to Au nanoparticles. This results in a color change which can be related to the concentration of As(III) or total inorganic As (i.e., As(III) and As(V)) concentration. Under optimal conditions, the µPAD is characterized by a limit of detection of 0.43 mg L−1 for total inorganic As (As(III) + As(V)) and 0.41 mg L−1 for As(III) and a linear calibration range in both cases of 1.2–8.0 mg As L−1. The newly developed µPAD-based method was validated by applying it to groundwater and freshwater samples and comparing the results with those obtained by conventional atomic spectrometric techniques. [ABSTRACT FROM AUTHOR]

Radiochromic film dosimetry has been commonly used for determination of dose measurement in radiotherapy for many years because of their high spatial resolution, low energy dependence and its approximate tissue equivalent. Additionally, it has other practical advantages, e.g.it is suitable for therapy range beam qualities, a water resistance material, a relatively insensitive to visible light, and does not need to make bathing process to obtain dose information. They are also independent to dose rate. Hence they are very useful and practical for clinical applications such as brachytherapy, electron therapy, skin dose measurements and stereotactic radiotherapy. Among them, the dynamic dose range of EBT3 radiochromic films are generally recommended for the dose range of 0.1 to 20 Gy. However, in this study, it is aimed to observe the behavior of EBT3 films in high dose range of up to 90 Gy under the irradiations. For this aim, the net optical densities were obtained with increasing dose values under photon and electron beams by employing three color scanning channel (red-green-blue). Thus, for making calibration curves, it was decided which color channel for EBT3 radiochromic film would be the most suitable one in different dose ranges. In experimental setup, the reference circumstances were first established and dose calibration procedure were carried out in RW3 phantom. Then the irradiated films were cut carefully into 2x2.5 cm2 pieces, and they were grouped into 2 as irradiation and control groups. The control group was waited for background, i.e. they are not irradiated. Before the irradiation, two groups of films have been scanned in flatbed scanner for three channels. After that, the irradiation group films was placed to align the exact place of effective point of ionization chamber under the reference condition. Later, they were irradiated one by one to up to 90 Gy with using 6 MV and 6 MeV beam qualities, respectively. Subsequently, both of film groups were again scanned in flatbed scanner for three –color channels. Optical densities and their standard deviations corresponding to the chosen dose values were obtained from the scanned films. Thus, calibration curves were plotted for all three colors channel according to two different beam conditions. The results obtained for 6 MV beam quality showed that if red color channel is selected for 0.9 Gy-7.3 Gy dose range, and green color channel is selected for 7.3 Gy-42.8 Gy dose range, and blue color channel is selected for 42.8 Gy-90.0 Gy dose range, the percentage uncertainty values in the obtained results are minimal. For the 6 MeV beam quality, if red color channel is selected for 0.9 Gy-7.7 Gy dose range, and green color channel is selected for 7.7 Gy-45.3 Gy dose range, and blue color channel is selected for 45.3 Gy-90.0 Gy dose range, the percentage uncertainty values in the obtained results are minimal. In conclusion, the percentage uncertainty values for the obtained results were evaluated for 6 MV photon and 6 MeV electron energies by using different scanning channels of EBT3 radiochromic film. It has been found that measurements having low percentage uncertainty values can be achieved by changing the scanning channel by deciding proper combinations with increasing doses for both energies (6MV photon and 6 MeV electron). The study also shows that EBT3 radiochromic films can be used at lower percentage uncertainty values ​​at doses higher than the recommended dose range values.

Gafchromic film, a commercially available radiochromic film, has been developed and widely used as an effective tool for radiation dose verification and quality assurance in radiotherapy. However, the orientation effect in scanning a film remains a concern for practical application in beam profile monitoring. To resolve this issue, the authors introduced a novel method using an overhead scanner (OHS) coupled with a tracing light board instead of a conventional flatbed scanner (FBS) to read Gafchromic EBT3 films. We investigated the orientation effect of the EBT3 film with a regular hexagonal shape after irradiation with 5 Gy x-rays (160 kV, 6.3 mA) and compared the digitized images acquired using a commercially available OHS (CZUR Aura) and a conventional FBS (EPSON GT-X980). As a result, RGB color intensities acquired from the OHS showed significantly lower orientation effect of the color intensities of RGB components than those from FBS. This finding indicates the high potential of the proposed method for achieving more precise two-dimensional dosimetry. Further studies are required to confirm the effectiveness of this method under different irradiation conditions over a wider dose range., (Creative Commons Attribution license.)

African leaves (Vernonia amygdalina Del.) is a nutrient-rich plant that has been widely used as a herbal plant. African leaves contain chlorophyll which identify compounds produced by a plant, such as flavonoids and phenols. Chlorophyll testing can be carried out nondestructively by using the SPAD 502 chlorophyll meter. However, it is quite expensive, so that another non-destructive method is developed, namely digital image analysis. Relationships between chlorophyll content and leaf image colour indices in the RGB, HSV, HSL, and Lab* space are examined. The objectives of this study are 1) to analyse the relationship between texture parameters of red, green, blue, grey, hue, saturation(HSL), lightness (HSL), saturation( HSV), value(HSV), L*, a*, and b* against the chlorophyll content in African leaves using a flatbed scanner (HP DeskJet 2130 Series); and 2) built a model to predict chlorophyll content in African leaves using optimised ANN through a feature selection process by using several filter methods. The best ANN topologies are 10-30-40-1 (10 input nodes, 40 nodes in hidden layer 1, 30 nodes in hidden layer 2, and 1 output node) with a trainlm on the learning function, tansig on the hidden layer, and purelin on the output layer. The selected topology produces MSE training of 0.0007 with R training 0.9981 and the lowest validation MSE of 0.012 with R validation of 0.967. With these results, it can be concluded that the ANN model can be potentially used as a model for predicting chlorophyll content in African leaves. [ABSTRACT FROM AUTHOR]

Paper surfaces under the microscopic view are observed to be formed by intertwisted wood fibers. Such structures of paper surfaces are unique from one location to another and are almost impossible to duplicate. Previous work used microscopic surface normals to characterize such intrinsic structures as a “fingerprint” of paper for security and forensic applications. In this work, we examine several key research questions of feature extraction in both scientific and engineering aspects to facilitate the deployment of paper surface-based authentication when flatbed scanners are used as the acquisition device. We analytically show that, under the unique optical setup of flatbed scanners, the specular reflection does not play a role in norm map estimation. We verify, using a larger dataset than prior work, that the scanner-acquired norm maps, although blurred, are consistent with those measured by confocal microscopes. We confirm that, when choosing an authentication feature, high spatial-frequency subbands of the heightmap are more powerful than the norm map. Finally, we show that it is possible to empirically calculate the physical dimensions of the paper patch needed to achieve a certain authentication performance in equal error rate (EER). We analytically show that log(EER) is decreasing linearly in the edge length of a paper patch. [ABSTRACT FROM AUTHOR]

We present a densitometric quantification method for triclosan in toothpaste, separated by high-performance thin-layer chromatography (HPTLC) and using a 48-bit flatbed scanner as the detection system. The sample was band-wise applied to HPTLC plates (10 × 20 cm), with fluorescent dye, Merck, Germany (1.05554). The plates were developed in a vertical developing chamber with 20 min of chamber saturation over 70 mm, using n-heptane–methyl tert-butyl ether–acetic acid (92:8:0.1, V/V) as solvent. The RF value of triclosan is hRF = 22.4, and quantification is based on direct measurements using an inexpensive 48-bit flatbed scanner for color measurements (in red, green, and blue) after plate staining with 2,6-dichloroquinone-4-chloroimide (Gibbs' reagent). Evaluation of the red channel makes the measurements of triclosan very specific. For linearization, an extended Kubelka–Munk expression was used for data transformation. The range of linearity covers more than two orders of magnitude and is between 91 and 1000 ng. The separation method is inexpensive, fast and reliable. [ABSTRACT FROM AUTHOR]

The color channel's effect on the dose-response of Gafchromic™ EBT2 and EBT3 radiochromic films irradiated with a 6 MeV electron beam in the range from 0 to 1000 cGy was investigated and compared. A Canon flatbed scanner was used to scan the irradiated Gafchromic™ EBT2 and EBT3 films, while ultraviolet-visible (UV-Vis) absorption spectra were analyzed with a spectrophotometer. Triple RGB channel, weighted and unweighted grey images were analyzed using the free software ImageJ. As the 6 MeV electron beam dose increases, the pixel values of the red, green, weighted, and unweighted grey images decrease exponentially for both Gafchromic™ EBT2 and EBT3 films. The blue channel fluctuates with the increase of 6 MeV electron beam dose for both EBT2 and EBT3 films and decreases the unweighted grey image more than the weighted greyscale image. The characteristic peaks at 582 ± 2 nm and 632 ± 2 nm of Gafchromic™ EBT2 and EBT3 films are correlated with the absorbed 6 MeV electron beam dose. The sensitivity deterioration constant b 3 (is a free parameter of fitting in units of (cGy−1)) of EBT2 film is higher than EBT3 at both characteristic peaks at 582 ± 2 nm, and 632 ± 2 nm, indicating that EBT2 has better sensitivity at the expense of dynamic range, whilst EBT3 has lower sensitivity but a higher dynamic range. In comparison to the red and green channels, UV-Vis absorption in the blue channel range between 450 nm and 490 nm has a weak response and a small dynamic range. The Gafchromic™ EBT2 and EBT3 films scan with monochromatic red or green channels resulting in increased sensitivity and a wider dynamic range. • The Blue channel fluctuates with dose increase, affecting unweighted grey image more than weighted greyscale image. • UV-Vis absorption in blue channel range has weak response and small dynamic range. • Characteristic peaks at 582 ± 2 nm and 632 ± 2 nm correlate with absorbed 6 MeV electron beam dose. • EBT2 has better sensitivity but lower dynamic range, whilst EBT3 has lower sensitivity but higher dynamic range. [ABSTRACT FROM AUTHOR]

Flatbed scanners (FBSs) provide non-contact scanning capabilities that could be used for the on-machine verification of layer contours in additive manufacturing (AM) processes. Layer-wise contour deviation assessment could be critical for dimensional and geometrical quality improvement of AM parts, because it would allow for close-loop error compensation strategies. Nevertheless, contour characterisation feasibility faces many challenges, such as image distortion compensation or edge detection quality. The present work evaluates the influence of image processing and layer-to-background contrast characteristics upon contour reconstruction quality, under a metrological perspective. Considered factors include noise filtering, edge detection algorithms, and threshold levels, whereas the distance between the target layer and the background is used to generate different contrast scenarios. Completeness of contour reconstruction is evaluated by means of a coverage factor, whereas its accuracy is determined by comparison with a reference contour digitised in a coordinate measuring machine. Results show that a reliable contour characterisation can be achieved by means of a precise adjustment of image processing parameters under low layer-to-background contrast variability. Conversely, under anisotropic contrast conditions, the quality of contour reconstruction severely drops, and the compromise between coverage and accuracy becomes unbalanced. These findings indicate that FBS-based characterisation of AM layers will demand developing strategies that minimise the influence of anisotropy in layer-to-background contrast. [ABSTRACT FROM AUTHOR]

Digital image photometry (DIP) was used to determine xylose concentration in liquid medium. Xylose was quantified by its color reaction with phloroglucinol in a 96-well microplate sample holder using a commercial flat-bed scanner followed by image analysis with free-access software (ImageJ). The Red (R) values showed linear correlation versus xylose concentration in the range of 1.0-10.0 mg/mL with correlation coefficient of 0.987. The DIP method was found to be accurate based on experimental pentose (versus theoretical) concentration values. The observed limits of detection (LOD) and quantification (LOQ) for xylose were 0.65 mg/mL and 2.17 mg/mL, respectively. The DIP method gave results that are reliable and comparable to other technical protocols requiring expensive equipment such as high performance liquid chromatograph (HPLC) or UV-visible spectrophotometer. The DIP method was used to evaluate the extent of xylose assimilation in liquid fermentation medium by four yeast strains. [ABSTRACT FROM AUTHOR]

Flour color is a very important quality characteristic of wheat flour, and it is frequently determined to control flour mill operation. Wheat flour mill laboratories use colorimeter to determine the color of wheat flour samples, which is represented as L*, a* and b* values in the CIE color system. A flatbed scanner is generally used to determine the color of foods as a cheap alternative to a colorimeter, which is still an expensive instrument. So, the ability of using a flatbed scanner to determine the color of wheat flour by digital image analysis was the main aim of the present study. Sixteen wheat flour samples from different milling streams of an industrial mill were used in this study. Ash content of wheat flour samples was determined. The L*, a* and b* color values of the samples were determined using image analysis technique for the image acquired by a flatbed scanner and a commercial colorimeter. Wheat flour samples were presented to instruments as a dry flour sample and a slurry sample. Correlation coefficient between combination of L*, a* and b* values obtained from the colorimeter and digital image analysis for dry and slurry samples were calculated. The results showed a negative correlation between ash content and the flour brightness (L* value) which is determined by the colorimeter and digital image analysis technique for dry and slurry flour samples. An increase in the correlation coefficient was noticed when determining the color for the slurry flour samples. Significant correlation between L*, a* and b* color values of the colorimeter and digital image analysis were found for slurry samples only. [ABSTRACT FROM AUTHOR]

Flatbed scanners (FBSs) provide non-contact scanning capabilities that could be used for the on-machine verification of layer contours in additive manufacturing (AM) processes. Layer-wise contour deviation assessment could be critical for dimensional and geometrical quality improvement of AM parts, because it would allow for close-loop error compensation strategies. Nevertheless, contour characterisation feasibility faces many challenges, such as image distortion compensation or edge detection quality. The present work evaluates the influence of image processing and layer-to-background contrast characteristics upon contour reconstruction quality, under a metrological perspective. Considered factors include noise filtering, edge detection algorithms, and threshold levels, whereas the distance between the target layer and the background is used to generate different contrast scenarios. Completeness of contour reconstruction is evaluated by means of a coverage factor, whereas its accuracy is determined by comparison with a reference contour digitised in a coordinate measuring machine. Results show that a reliable contour characterisation can be achieved by means of a precise adjustment of image processing parameters under low layer-to-background contrast variability. Conversely, under anisotropic contrast conditions, the quality of contour reconstruction severely drops, and the compromise between coverage and accuracy becomes unbalanced. These findings indicate that FBS-based characterisation of AM layers will demand developing strategies that minimise the influence of anisotropy in layer-to-background contrast.

Abstract—: Soil color is the most important diagnostic feature in soil studies, though still being determined mainly qualitatively. Uncertainty in color determination can be eliminated by the transition to the precise color estimate in the CIELAB space coordinates. The results of color study for 347 soil samples are presented. These samples were obtained from the area of 274 ha in the southern taiga landscapes. The possibility to differentiate between twelve main horizons according to their color characteristics in both wet and dry states is shown for ten soil types (podzolic, bog podzolic, lowmoor peat bog, soddy, soddy gley, acid soddy alluvial, acid meadow alluvial, meadow-bog alluvial, silty mucky gley alluvial, and silty-peat bog alluvial soils). The color characteristics of soil horizons correlate with the landscape positions of the soils: watershed slopes, terraces, ravines, backswamps, and floodplain of the Klyazma River. Among three optical indices (L*, a*, and b*), only lightness (L*) correlates reliably with the horizons distinguished in the Classification and Diagnostics of Soils of the Soviet Union (1977), Classification and Diagnostic System of Russian Soils (2004-2008), and the World Reference Base for Soil Resources (2014). [ABSTRACT FROM AUTHOR]

Abstract: The review systematizes the works of the researchers of the Division of Analytical Chemistry at the Moscow State University in the field of chemical colorimetry for the last 10 years. Various versions of the method, its possibilities, and prospects of use for solving many analytical problems are considered. The main ways of the development of chemical colorimetry are discussed. [ABSTRACT FROM AUTHOR]

In this study, we developed a flatbed-scanner-based Cu 2+ -selective signaling method using a coumarin–benzopyrylium conjugated dye platform. The designed sensors ( CB-1 and CB-2 ) were readily synthesized by the reaction of coumarin–benzopyrylium hydrazide with salicylaldehyde or 2-hydroxynaphthaldehyde, respectively. Sensor CB-1 exhibited pronounced colorimetric and fluorescence signaling behaviors toward Cu 2+ ions in 50% aqueous acetate buffered (pH 4.7) acetonitrile solution. The Cu 2+ signaling of the developed sensor was not affected by the presence of environmentally relevant metal ions. The detection limit of sensor CB-1 for Cu 2+ ions was estimated to be 4.0 × 10 −8  M (2.5 ppb). In addition, to develop a convenient and straightforward Cu 2+ detection method for nonprofessional personnel and practical field applications, the colorimetric determination of Cu 2+ ions using a flatbed scanner, a readily available IT device, was investigated. Using simulated semiconductor wastewater as a practical sample, the Cu 2+ levels were readily determined by a flatbed scanner in transmittance mode with a sensitive detection limit of 2.9 × 10 −7  M (18 ppb). [ABSTRACT FROM AUTHOR]

ABSTRACT: Along with the Carnegie Collection in the United States and the Kyoto Collection in Japan, the Blechschmidt Collection (Georg‐August‐University of Göttingen, Germany) is a major historical human embryo and fetus collection. These collections are of enormous value to human embryology; however, due to the nature of the historical histological specimens, some stains are fading in color, and some glass slides are deteriorating over time. To protect these specimens against such degradation and ensure their future usefulness, we tried to apply modern image scanning and computational reconstruction. Samples of histological specimens of the Blechschmidt Collection were digitized into images using commercial flatbed scanners with a resolution of 4800 pixels per inch. Two specimens were reconstructed into three‐dimensional (3D) images by using modern techniques to vertically stack two‐dimensional images of the slices into 3D blocks. The larger specimen of crown‐rump length (CRL) 64.0 mm, a series of very large histological sections in human embryology, was reconstructed clearly, with its central nervous system segmented before stacking. The smaller specimen of CRL 17.5 mm was also reconstructed into 3D images. The outer surface of the embryo was intact, and its development was classified according to the widely used Carnegie stages (CSs). The CS of the specimen was identified as the later half of CS 20. The invaluable Blechschmidt Collection can be revisited for further research with modern techniques such as digital image scanning and computational 3D reconstruction. [ABSTRACT FROM AUTHOR]

Wheat infections caused by fungi of the genus Fusarium decrease yields and have serious economic consequences. The produced mycotoxins have harmful effects on human and animal health. The aim of this study was to develop classification models based on selected textural parameters to distinguish between infected and healthy wheat kernels. The classification accuracy of kernels positioned on the ventral side was determined at 78-100% in the model based on textural parameters from hyperspectral images, and at 95-100% based on images generated by a flatbed scanner. Kernels positioned on the dorsal side were correctly classified in 78-98% based on hyperspectral images, and in 92-100% based on colour images. In the models combining textural parameters from the ventral and dorsal sides of wheat kernels, classification accuracy reached 76-98% in hyperspectral images, and 94-100% in images generated by a flatbed scanner. The imaging technique—flatbed scanner and the ventral side of the kernels provided higher classification accuracy results. The results will contribute to further research aiming to develop models for the determination of fungal chemotypes and/or fungal species based on selected textural features of wheat kernels. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effect of scanner parameters on colorimetric detection of μPADs was evaluated. • Scanner settings, blank colour and image acquisition mode had the greatest effect. • Effect of the main μPAD characteristics on its colorimetric detection was studied. • μPAD covering (e.g., lamination) had the greatest effect. • Guidelines for optimal data acquisition and µPAD manipulation were proposed. Office style scanners are often used by researchers for the colorimetric detection in the development of microfluidic paper-based analytical devices (µPADs). However, little attention has been paid to nuances in calibration curve responses caused by varying settings of a single image-capturing device. Hence, in this study, the effect of parameters, such as the scanner operation conditions, the method of data analysis used (e.g., choice of colour space system, suitable channel), and the influence of the physical characteristics of the µPAD (e.g., template colour, type of lamination pouches used) on the colorimetric detection were evaluated for the first time. Combinations of the scanning parameters were thoroughly examined and their impact on the quality of a mock calibration curve assessed. The most sensitive calibration curve was achieved only by the selection of the optimal scanning conditions combined with an appropriate choice of colorimetric system. A flatbed scanner, used in this study, showed greater variation of signal with varying scanning setup, whereas a portable scanner provided nearly identical responses under diverse scanning conditions. Gamma correction, scanning resolution, region of interest (ROI) surrounding colour (i.e., template colour), bit-depth, image file type, and the number of analysed pixels were found not to markedly affect the dynamics of the calibration curve when colour in the ROI is homogeneous. Parameters that had an effect on the colorimetric detection were the scanner settings, colour of the blank, image acquisition mode (colour vs greyscale), and µPAD covering (e.g., lamination). Based on these findings, generic guidelines for optimal data acquisition and µPAD manipulation with respect to µPAD calibration have been formulated. [ABSTRACT FROM AUTHOR]

Background: Belowground processes play an essential role in ecosystem nutrient cycling and the global carbon budget cycle. Quantifying fine root growth is crucial to the understanding of ecosystem structure and function and in predicting how ecosystems respond to climate variability. A better understanding of root system growth is necessary, but choosing the best method of observation is complex, especially in the natural soil environment. Here, we compare five methods of root image acquisition using inexpensive technology that is currently available on the market: flatbed scanner, handheld scanner, manual tracing, a smartphone application scanner and a time-lapse camera. Using the five methods, root elongation rate (RER) was measured for three months, on roots of hybrid walnut (Juglans nigra × Juglans regia L.) in rhizotrons installed in agroforests. Results: When all methods were compared together, there were no significant differences in relative cumulative root length. However, the time-lapse camera and the manual tracing method significantly overestimated the relative mean diameter of roots compared to the three scanning methods. The smartphone scanning application was found to perform best overall when considering image quality and ease of use in the field. The automatic time-lapse camera was useful for measuring RER over several months without any human intervention. Conclusion: Our results show that inexpensive scanning and automated methods provide correct measurements of root elongation and length (but not diameter when using the time-lapse camera). These methods are capable of detecting fine roots to a diameter of 0.1 mm and can therefore be selected by the user depending on the data required. [ABSTRACT FROM AUTHOR]

Introduction The required overall uncertainty in dose delivery in modern radiotherapy is 3.5% of a prescribed dose (one standard deviation). In vivo dosimetry is the simple method in dose delivery control. In this work we present our results concerning the precision of dose measurement with Gafchromic EBT films used within the dose range measured in the in vivo dosimetry of photon external beam radiation therapy. Materials and methods The rectangular pieces of Gafchromic EBT films of 1 cm × 2 cm were prepared. They were prepared from three different films from two batches. For each film four sets of samples consisting of 18 pieces were made. Each set of films was exposed perpendicularly to 6 MV photon beams at several dose levels from 2 cGy to 190 cGy. The net optical density was read with the flatbed document scanner Epson Expression 10000 XL and the ImageJ software. The calibration curves for each set of Gafchromic EBT samples were obtained. The mathematical formulae describing the calibration curve was fitted to the measurements results. Four different calibration procedures were analyzed based on one or four sets of samples and with or without use of image filtration (median filter). Two sources of uncertainty were analyzed separately: the calibration curve measurements, and the precision of formulae fitting. Results For the protocol described in this paper, the overall dose measurement uncertainty of less than 2% (one standard deviation) for doses of about 25 cGy and higher was found for calibration procedure based on four sets of film samples with image filtration, and less than 3% for calibration procedure based on one set of film samples with image filtration. For two films from the same batch almost identical calibration curves were obtained. It allows to use one calibration curve for all films from the same batch. There were larger differences for films from two different batches. Conclusions The Gafchromic EBT films have sufficient accuracy for dose measurements above 20 cGy and may be an interesting alternative for the semiconductor or thermoluminescent detectors as an in vivo dosimeter. Contrary to these detectors Gafchromic EBT films are transparent for radiation. [ABSTRACT FROM AUTHOR]

Flatbed scanner is a low cost, fast, easy to operate, and efficient device for high quality digital image acquisition. The present study extended the applications of flatbed scanners from conventional air void counting to pore structure characterization of concrete affected by freezing–thawing (F–T) action. Imaging-analysis parameters (specific area and roundness of pores, density and length of cracks, and fractal dimension of pore outlines) were extracted from flatbed-scanned images, and conventional parameters (dynamic elastic modulus, mass and Cl − diffusion coefficient) were measured after every 25 F–T cycles. Both the imaging-analysis parameters and the conventional parameters varied with increasing F–T cycle. The successful use of a flatbed scanner to detect changes in concrete pore structure with frost damage in this research increases the expectation of its application to more aspects of concrete engineering. [ABSTRACT FROM AUTHOR]

A simple and relatively fast image-analysis method using digital images, obtained with a flatbed scanner, has been described. The method was used for the simultaneous determination of four common food dyes, namely, carmoisine, brilliant blue, sunset yellow, and quinoline yellow, in binary mixtures in commercial products without a need for any prior separation steps. The results obtained were validated against a standard high-performance liquid chromatography method and a good agreement was obtained. The parameters affecting the experimental results were optimized. Under the optimal conditions, the method provided acceptable linear ranges (20 e 250 mg/L) with correlation coefficients higher than 0.998, suitable precision (relative standard deviation ≤ 4.5%), and limits of detection between 4.82 and 8.05 mg/L. [ABSTRACT FROM AUTHOR]

This paper describes a methodology which allows a commercial flatbed scanner to be transformed into a two-coordinate measuring machine which is capable of providing traceable measurements. This methodology requires an initial adjustment in order to convert the reference system of the flatbed scanner into a Cartesian reference system, thereafter calibrating it using standards with metrological traceability. Circle and line scales have been used in this case, but other alternative standards may also be employed by merely adapting the calculation algorithms. Once the equipment has been calibrated, the characterisation process of a relatively complex part and the results obtained for different critical dimensions are indicated as an example. The criteria used to determine and propagate the uncertainties in measurement, as recommended in Supplements 1 and 2 to the “Guide to the expression of uncertainty in measurement” (GUM), are also indicated. [ABSTRACT FROM AUTHOR]