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Background: Leaf area index (LAI) is an important indicator for assessing plant growth and development, and is also closely related to photosynthesis in plants. The realization of rapid accurate estimation of crop LAI plays an important role in guiding farmland production. In study, the UAV‐RGB technology was used to estimate LAI based on 65 winter wheat varieties at different fertility periods, the wheat varieties including farm varieties, main cultivars, new lines, core germplasm and foreign varieties. Color indices (CIs) and texture features were extracted from RGB images to determine their quantitative link to LAI. Results: The results revealed that among the extracted image features, LAI exhibited a significant positive correlation with CIs (r = 0.801), whereas there was a significant negative correlation with texture features (r = −0.783). Furthermore, the visible atmospheric resistance index, the green–red vegetation index, the modified green–red vegetation index in the CIs, and the mean in the texture features demonstrated a strong correlation with the LAI with r > 0.8. With reference to the model input variables, the backpropagation neural network (BPNN) model of LAI based on the CIs and texture features (R2 = 0.730, RMSE = 0.691, RPD = 1.927) outperformed other models constructed by individual variables. Conclusion: This study offers a theoretical basis and technical reference for precise monitor on winter wheat LAI based on consumer‐level UAVs. The BPNN model, incorporating CIs and texture features, proved to be superior in estimating LAI, and offered a reliable method for monitoring the growth of winter wheat. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Positional and multicolor photometric observations of near-Earth asteroids were carried out using the SBG telescope of the Kourovka Astronomical Observatory of Ural Federal University and the Zeiss-1000 telescope of the Simeiz Observatory of INASAN in 2022–2023. Based on the results of positional observations with the SBG telescope, improved orbital elements were obtained for seven asteroids. The periods of axial rotation of seven asteroids were estimated from photometric observations. Based on the results of photometric observations in the B, V, R, I filters, color indices were obtained for six asteroids. [ABSTRACT FROM AUTHOR]

Approaches for remote sensing can be used to estimate the influence of changes in environmental conditions on terrestrial plants, providing timely protection of their growth, development, and productivity. Different optical methods, including the informative multispectral and hyperspectral imaging of reflected light, can be used for plant remote sensing; however, multispectral and hyperspectral cameras are technically complex and have a high cost. RGB imaging based on the analysis of color images of plants is definitely simpler and more accessible, but using this tool for remote sensing plant characteristics under changeable environmental conditions requires the development of methods to increase its informativity. Our review focused on using RGB imaging for remote sensing the characteristics of terrestrial plants. In this review, we considered different color models, methods of exclusion of background in color images of plant canopies, and various color indices and their relations to characteristics of plants, using regression models, texture analysis, and machine learning for the estimation of these characteristics based on color images, and some approaches to provide transformation of simple color images to hyperspectral and multispectral images. As a whole, our review shows that RGB imaging can be an effective tool for estimating plant characteristics; however, further development of methods to analyze color images of plants is necessary. [ABSTRACT FROM AUTHOR]

Variations in illumination and image background present challenges for using UAV RGB imagery. Existing studies often overlook these issues, especially in rice. To separately evaluate the impacts of illumination variation and image background on rice LAI assessment, this study utilized Retinex correction and image segmentation to eliminate illumination variations and background effects, and then analyzed the changes in color indices and their relationship with LAI before and after implementing these methods separately. The results indicated that both Retinex correction and image segmentation significantly enhanced the correlation between color indices and LAI at different growth stages as well as the accuracy of constructing a multivariate linear regression model separately. Our analysis confirmed the significance of accounting for variation in illumination and rice field backgrounds in LAI analysis when using UAV RGB images. Illumination variation and image background elements significantly degrade the accuracy of LAI estimation. [ABSTRACT FROM AUTHOR]

In this research, three different types of hydrocolloids (chitosan,tragacanth, hydroxy propyl methyl cellulose) 2 % on the basis of flour weight and three different kinds of emulsifiers (lecithin, glycerol mono stearate, propylene glycol) 1 % on the basis of flour weight, were added in different proportions to sponge cake's formulation in order to assay quality indicators of cake. Bulk density, true density, aw (water activity), moisture, amylose content, texture analysis, microbial growth and colour (hue, chroma) were used as quality indices during cake's shelf life period (12 weeks). Colour, aw and firmness did not significantly affect by any of hydrocolloids and emulsifiers and they affected only by the storage time. HPMC and lecithin had the most effect on decreasing true density and bulk density respectively. Results indicated that chitosan was the most effective hydrocolloid for retention of moisture in cakes. The amylose content increased by increasing lecithin during the six weeks and PG had significant effect in last three weeks of storage time. Lecithin also significantly affected the Fmax, so the cake's with high levels of lecithin in formulation had tender crust, and hardness decreased during the first six weeks of shelf life. No microbial growth was reported in addition of different proportions of hydrocolloids and emulsifiers. Except of lecithin, two other emulsifiers had no significant effect on Chroma index in comparison with control cakes. [ABSTRACT FROM AUTHOR]

The goal of this work was to examine the effects of sonication time, edible coating concentration (with guar gum), and °Brix (sucrose solution) on the osmotic dehydration (OD) parameters (mass reduction, water loss, soluble solids gain, and rehydration ratio) and the appearance properties (color indices and surface area) of quince slices using a response surface methodology (RSM) approach based on the central composite design (CCD), for the optimization of the process. The process parameters, sonication treatment time (5–10 min; 40 kHz and 150 W), edible coating concentration using guar gum (0.05%–0.15%, w/w), and osmotic concentration using sucrose solution (20%–50%, w/w), were investigated and optimized for OD of quince slices. After each OD process, the quince slices were dehydrated in an oven at 70°C for 240 min. Results demonstrated a good correlation between empirical data with the linear model. Using the optimization method, optimum input operating conditions were determined to be a sonication time of 5 min, guar gum concentration of 0.05%, and sucrose concentration of 37.19°Brix. At this optimum point, the OD process of quince slices reached the optimal mass reduction (17.74%), water loss (25.77%), soluble solids gain (8.03%), rehydration ratio (206.19%), lightness (77.6), redness (0.60), yellowness (34.84), total color change (ΔE) (8.92), and area changes (7.59%). [ABSTRACT FROM AUTHOR]

Variations in illumination and image background present challenges for using UAV RGB imagery. Existing studies often overlook these issues, especially in rice. To separately evaluate the impacts of illumination variation and image background on rice LAI assessment, this study utilized Retinex correction and image segmentation to eliminate illumination variations and background effects, and then analyzed the changes in color indices and their relationship with LAI before and after implementing these methods separately. The results indicated that both Retinex correction and image segmentation significantly enhanced the correlation between color indices and LAI at different growth stages as well as the accuracy of constructing a multivariate linear regression model separately. Our analysis confirmed the significance of accounting for variation in illumination and rice field backgrounds in LAI analysis when using UAV RGB images. Illumination variation and image background elements significantly degrade the accuracy of LAI estimation.

Approaches for remote sensing can be used to estimate the influence of changes in environmental conditions on terrestrial plants, providing timely protection of their growth, development, and productivity. Different optical methods, including the informative multispectral and hyperspectral imaging of reflected light, can be used for plant remote sensing; however, multispectral and hyperspectral cameras are technically complex and have a high cost. RGB imaging based on the analysis of color images of plants is definitely simpler and more accessible, but using this tool for remote sensing plant characteristics under changeable environmental conditions requires the development of methods to increase its informativity. Our review focused on using RGB imaging for remote sensing the characteristics of terrestrial plants. In this review, we considered different color models, methods of exclusion of background in color images of plant canopies, and various color indices and their relations to characteristics of plants, using regression models, texture analysis, and machine learning for the estimation of these characteristics based on color images, and some approaches to provide transformation of simple color images to hyperspectral and multispectral images. As a whole, our review shows that RGB imaging can be an effective tool for estimating plant characteristics; however, further development of methods to analyze color images of plants is necessary.

Aboveground biomass (AGB) is an important basis for wheat yield formation. It is useful to timely collect the AGB data to monitor wheat growth and to build high-yielding wheat groups. However, as traditional AGB data acquisition relies on destructive sampling, it is difficult to adapt to the modernization of agriculture, and the estimation accuracy of spectral data alone is low and cannot solve the problem of index saturation at later stages. In this study, an unmanned aerial vehicle (UAV) with an RGB camera and the real-time kinematic (RTK) was used to obtain imagery data and elevation data at the same time during the critical fertility period of wheat. The cumulative percentile and the mean value methods were then used to extract the wheat plant height (PH), and the color indices (CIS) and PH were combined to invert the AGB of wheat using parametric and non-parametric models. The results showed that the accuracy of the model improved with the addition of elevation data, and the model with the highest accuracy of multi-fertility period estimation was PLSR (PH + CIS), with R2, RMSE and NRMSE of 0.81, 1248.48 kg/ha and 21.77%, respectively. Compared to the parametric models, the non-parametric models incorporating PH and CIS greatly improved the prediction of AGB during critical fertility periods in wheat. The inclusion of elevation data therefore greatly improves the accuracy of AGB prediction in wheat compared to traditional spectral prediction models. The fusion of UAV-based elevation data and image information provides a new technical tool for multi-season wheat AGB monitoring. [ABSTRACT FROM AUTHOR]

The results of photometric observations of two bright blazars of the northern hemisphere, namely, BL Lacertae and 1ES 1426+428, during 2018–2020 through BVRI filters of the Johnson/Bessel system are given. The observations were performed with the two telescopes: AZT-8 of observation station Lisnyky of the Astronomical Observatory of the Taras Shevchenko National University of Kyiv (Kyiv oblast, Ukraine) and Zeiss-600 of high-altitude observatory Peak Terskol of the International Center for Astronomical, Medical, and Ecological Research (IC AMER) of the National Academy of Sciences of Ukraine. In total, more than sixty nights of observations were recorded and processed. The main goals have been in performing a cross-matching analysis of blazar light curves in BVRI bands to detect the short-term variability (STV) and long-term variability (LTV) and to investigate the chromaticity of color parameters. For both objects, fluctuations of brightness up to 1m in 2018–2020 were recorded in the BVRI bands of the Johnson/Bessel system with a total error of 0.03m–0.1m. The intraday variability (IDV) was revealed for BL Lacertae November 17/November 18, 2018. During the calculations of the color indices, the trend of bluish color with an increase in the brightness (bluer-when-brighter, BWB) was found. For BL Lacertae, the LTV was reliably detected by using different pairs of filters. Also, the BWB trend with an average correlation (over 0.5) was recorded for 1ES 1426+428. The presence of such fluctuations in the color of blazars was due to the synchrotron radiation of the jet. The revealed partial correlation of variations in brightness with low time resolution (more than a week) between the photometric optical observations and the data of the Fermi gamma-ray telescope in 2018–2020 require additional research. [ABSTRACT FROM AUTHOR]

A series of ceramics in the system CaO-Cr2O3-MgO-SiO2 was synthesized via solid-state high temperature sintering at 1000, 1100 and 1200 °C. The resulting ceramics were examined by powder X-ray diffraction, scanning electron microscopy, infrared and electron paramagnetic resonance spectroscopy. The color characteristics were measured spectrophotometrically. It was found that under the synthesis conditions multiphase ceramics were obtained which contain diopside, wollastonite, magnesiochromite, cristobalite, tridymite and periclase in various proportions. The synthesized ceramics are gray, gray-green and green in color, depending on the content of Cr additive, temperature of furnace and phase composition. [ABSTRACT FROM AUTHOR]

Aboveground biomass (AGB) is an important basis for wheat yield formation. It is useful to timely collect the AGB data to monitor wheat growth and to build high-yielding wheat groups. However, as traditional AGB data acquisition relies on destructive sampling, it is difficult to adapt to the modernization of agriculture, and the estimation accuracy of spectral data alone is low and cannot solve the problem of index saturation at later stages. In this study, an unmanned aerial vehicle (UAV) with an RGB camera and the real-time kinematic (RTK) was used to obtain imagery data and elevation data at the same time during the critical fertility period of wheat. The cumulative percentile and the mean value methods were then used to extract the wheat plant height (PH), and the color indices (CIS) and PH were combined to invert the AGB of wheat using parametric and non-parametric models. The results showed that the accuracy of the model improved with the addition of elevation data, and the model with the highest accuracy of multi-fertility period estimation was PLSR (PH + CIS), with R2, RMSE and NRMSE of 0.81, 1248.48 kg/ha and 21.77%, respectively. Compared to the parametric models, the non-parametric models incorporating PH and CIS greatly improved the prediction of AGB during critical fertility periods in wheat. The inclusion of elevation data therefore greatly improves the accuracy of AGB prediction in wheat compared to traditional spectral prediction models. The fusion of UAV-based elevation data and image information provides a new technical tool for multi-season wheat AGB monitoring.

This paper presents the results of the photometric CCD observations of the NEA (2100) Ra-Shalom carried out on August 24–29, 2019, at the 1-m telescope of the Sanglokh Observatory of the Institute of Astrophysics, National Academy of Sciences of the Republic of Tajikistan. The rotation period P = 19.8 ± 0.1 h was determined. Composite light curves were plotted in the photometric BVR bands; the brightness amplitude ΔV = 0.61m ± 0.05m and the average values of the color indices B–V = 0.75m ± 0.05m, V–R = 0.40m ± 0.02m were determined. Variations in the color indices with rotation period are within the measurement errors, which indicates that the reflectivity of Ra-Shalom's surface is uniform. The absolute stellar magnitude of the asteroid is 15.91m ± 0.10m. The ratio of the asteroid's axes a/b = 1.75. [ABSTRACT FROM AUTHOR]

Marmalade is a processed product of some plant organs such as fruit, flower, fruit peel and tuber in which the plant parts used are small and well homogenized. Sugar is used as a sweetener in the preparation of marmalade. In this study, the use of date syrup as a substitute for sucrose used in marmalade formulation was studied. The constrained mixture design was used to achieve the optimal formulation and the effect of sugar substitution with date palm syrup on properties of marmalade was studied. The ingredients used in the formulation were plum paste (35-65%), sugar syrup (0-65%) and date syrup (0-65%). Ten formulas were produced based on the constrained mixture design and their physical, chemical and sensorial properties were investigated. The results showed that plum paste had the greatest effect on increasing the viscosity and total acidity of marmalade, while total soluble solids decreased with increasing the amount of plum paste in the formulation. The L* index of the samples decreased with increasing date syrup and plum paste and the redness of marmalade increased with increasing plum paste. Sensory evaluation of the produced formulations showed that the increase in plum paste increased the consistency, spreadability, color and overall acceptance, while the sweetness and taste and flavor were more affected by the increase in date syrup. Optimal formulation was obtained in the ratios of 58% plum paste, 12% sugar syrup and 30% date syrup and in the optimal formulation the total acidity, total phenolic compounds, and viscosity of marmalade at 20 °C were equal to 2.07 g citric acid/100 g, 112.4 mg gallic acid/100 g, and 3961 cp, respectively. [ABSTRACT FROM AUTHOR]

The physicochemical stability of six bread formulations with different tilapia flour (BTF) levels (0%, 2.5%, 5%, 10%, 15%, and 20%) in substitution to wheat flour was investigated regarding moisture content, water activity (aw), pH, instrumental color parameters, texture profile, lipid and protein oxidation on days 0, 2, 4, 6 and 8 at 25°C. BTF10%, BTF15%, and BTF20% displayed lower (P

We consider prospects for investigating asteroids with the multicolor photometric method at the Robophot telescope—a robotic telescope of the Dall–Kirkham system with a 0.6-m primary mirror and a focal length of 4.2 m. It is equipped with a three-channel photometer with the g', r', and i' filters of the SDSS photometric system, and the field of view is 20′. The use of a three-channel photometer in observations of small bodies will make it possible to construct multicolor light curves without phase delays. Diagrams of the r' – i' and g' – r' color indices will provide the means of classifying the C- and S-type asteroids. From the high-accuracy light curves, the rotation parameters of asteroids can be determined, for which it is necessary to take the Yarkovsky effect into account correctly. The results of multicolor photometric observations at the Robophot telescope will allow for solving complex scientific problems related to the studies of the physical and dynamic evolution of small bodies in the Solar System. [ABSTRACT FROM AUTHOR]

Drying is one of the most important post-harvesting processes with the aim of increasing the storage time. The present study investigates and compares color changes and shrinkage of red beetroot thin layers in four different drying methods (hot air flow, microwave, vacuum and freeze drying). The process of changing these two parameters was simulated by fitting to different models. The experiments were carried out in hot air and vacuum air dryers at three temperature levels (50, 70 and 90 °C), in microwave dryer at a power level of 180, 360 and 600 W, and in a freeze dryer at -50 °C.The results showed that the changes in the brightness index (L) and yellowness (b) relative to the time were increasing and the trend of changes in the red index (a) was decreasing. The slightest changes in the parameters of brightness, redness and yellowness occurred in freeze drying, microwave and vacuum, respectively. The overall results showed that the highest amount of color change (ΔE) was 1.59 in drying by microwave and at 180 W, and the lowest drying rate was 0.76 in freeze drying. Also, shrinkage changes in sugar beet samples showed that the use of freeze dryer reduced the amount of shrinkage by 10-25% compared to the other three methods of drying. Also, modeling of color parameters and shrinkage showed that exponential models have higher ability to predict the process of color variation and shrinkage. [ABSTRACT FROM AUTHOR]

Highlights • The SJCS saved 62% energy compared to the conventional boiling at the atmospheric pressure. • Increasing the flow rate caused a decrease of 40% in COP of the desiccant bed. • A maximum solar electricity fraction value of 0.76 was found. • Color indices of solar concentrated juice were competitive with conventional method. Abstract A closed-loop solar juice concentration system equipped with a liquid desiccant bed was investigated for barberry juice concentration and compared with the conventional evaporation processes. An unglazed flat plate solar collector was used for simultaneous regeneration of the desiccant solution. Experimental evaluation of the designed system was carried out at different flow rates of moving air as the circulating gas. The results showed that concentration time decreased from 480 to 360 min when the flow rate increased from 0.006 to 0.014 kg/s. Furthermore, raising the flow rate caused a decrease of 40% in effectiveness of dehumidification and an improvement of 33% in moisture evaporation rate. A minimum specific energy consumption of 3.33 MJ/kg was achieved at the air flow rate of 0.006 kg/s. The results indicated that all concentration methods significantly (p < 0.05) changed the color indices (L* , a* , b* , hue angle, chroma and total color difference) of barberry juice. Although color quality of the concentrated juice by the rotary evaporator was better than the other methods, the solar juice concentration system at the lowest flow rate can be proposed for fruit juice processing industries with regard to energy consumption and acceptable and competitive color quality of the processed juices. [ABSTRACT FROM AUTHOR]

The design of proxy techniques is an innovative tool to monitor the potentially toxic elements of pollution in road dust. This study evaluated the use of road dust color as a proxy methodology to identify samples contaminated with presumably contaminating elements. FRX determined the concentrations of Fe, Ti, Rb, Sr, Y, Cu, Zn, and Pb in eighty-five road dust samples. The appliance of the RGB system and the Munsell color cards identified five color groups of road dust samples. The discriminant analysis validated these groups by colorimetric indices and presumably contaminating elements. The “very dark gray” color of road dust contains the highest concentrations of Pb, Cu, Zn, and Y. The redness and saturation rates showed high correlations with presumably contaminating elements in “dark gray” and “very dark gray” color samples. The color of road dust, as a proxy technique, allows identifying samples contaminated with presumably contaminating elements.

We present photometric observations of 25 small asteroids from different families (Eos, Erigone, Flora, Maria, Massalia, Phocaea and Zita) and dynamical groups. We derive their synodic periods and lightcurve amplitudes, as well as V–R color indices, and absolute magnitudes. Furthermore, we revise their albedos using the determined absolute magnitudes. Three of the objects are studied for the first time. We also make estimates of the diameters of four asteroids. Many of the observed asteroids have short rotation periods and small amplitudes of the lightcurves, which may be indicative of their potential binary nature. Our photometry in combination with future data can be used in further studies. Analysis of the parameters obtained for the observed asteroids, such as absolute magnitudes, revised albedos, as well as color indices obtained from the SDSS and Sky-Mapper surveys, makes it possible to effectively classify them taxonomically. • Photometry of asteroids. • The families of asteroids. • Lightcurves and rotational period, of small asteroids. • Color indices and absolute brightness of small asteroids. • Albedo of asteroids. [ABSTRACT FROM AUTHOR]

The physicochemical stability of six bread formulations with different tilapia flour (BTF) levels (0%, 2.5%, 5%, 10%, 15%, and 20%) in substitution to wheat flour was investigated regarding moisture content, water activity (aw), pH, instrumental color parameters, texture profile, lipid and protein oxidation on days 0, 2, 4, 6 and 8 at 25°C. BTF10%, BTF15%, and BTF20% displayed lower (P < 0.05) moisture, aw, lightness index, cohesiveness, springiness and resilience, and higher (P < 0.05) pH, redness index, yellowness index, hardness, chewiness, lipid and protein oxidation compared to BTF0%, BTF2.5%, and BTF5%. Nevertheless, pH drops, lipid and protein oxidation were less pronounced (P < 0.05) for BTF10%, BTF15%, and BTF20% during storage. Although quality loss has been observed in breads containing ≥ 10% TF, bread at 5% TF did not display altered traditional wheat bread physicochemical characteristics and may be an attractive alternative for the health food market. [ABSTRACT FROM AUTHOR]

Abstract Foam-mat drying has been recently welcomed as an effective technique since it lacks deficiencies that plague conventional methods including poor water absorption and long process time. In this study, effect of hot air temperature (50, 60 and 70 °C) on quality properties of lime juice was investigated during foam-mat drying. The process was also simulated to determine the effect of temperature on the uniformity of moisture and temperature distributions during drying. Increase in temperature improved powder flowability. With a decrease in temperature, water absorption index increased by 17.74%. Moreover, effective moisture diffusion coefficient increased as a result of a rise in temperature, which, in turn, increased the drying rate by 20.23%. Increase in temperature also resulted in a 1.80% increase in the total color change and 6.60%, 1.18% and 1.35% decrease in chroma index, hue angle and browning index, respectively. A correlation coefficient of 0.903 was achieved between experimental and simulated data. Uniform distributions of temperature and moisture during drying resulted in an improvement in the qualitative properties of the final product regarding the uniformity of the powder's moisture content, improvement of water absorption properties and, finally, increase in the product's quality. Graphical abstract 3D moisture content profile at the end of drying process at air temperature 70 °C. Image 1 Highlights • Experimental and numerical foam-mat drying of lime juice was examined. • Increase in temperature from 50 to 70 °C resulted in a 20.23% rise in drying rate. • Uniform temperature and moisture distributions were obtained during the process. • 17.74% improvement in the powder's water absorption index was noticed at 50 °C. • The methodology may be a desirable counterpart for industrial applications. [ABSTRACT FROM AUTHOR]

Abstract—The correlations of the color indices of central galaxies (Mr < -20.7) and their faint neighboring galaxies (Mr < -20.7) using the sample based on the SDSS DR9 (N = 60 561) have been studied. The galaxy sample was limited by the red shift 0.02 < z ≤ 0.06 and absolute magnitude -24m < Mr < -19.4m. The "Random Forest" method of machine learning was used to determine the morphological type of the galaxies. The statistically significant correlation was found only for the "central galaxies-nearest neighbor galaxy" pairs in which the distance between the components is less than 100 kpc and each of the components is an early type galaxy. The obtained results testify to the hierarchical scenario of the evolution of galaxies. [ABSTRACT FROM AUTHOR]

Time series of vegetation indices (e.g. normalized difference vegetation index [NDVI]) and color indices (e.g. green chromatic coordinate [ G CC ]) based on radiometric measurements are now available at different spatial and temporal scales ranging from weekly satellite observations to sub-hourly in situ measurements by means of near-surface remote sensing (e.g. spectral sensors or digital cameras). In situ measurements are essential for providing validation data for satellite-derived vegetation indices. In this study we used a recently developed method to calculate NDVI from near-infrared (NIR) enabled digital cameras (NDVI C ) at 17 sites (for a total of 74 year-sites) encompassing six plant functional types (PFT) from the PhenoCam network. The seasonality of NDVI C was comparable to both NDVI measured by ground spectral sensors and by the moderate resolution imaging spectroradiometer (MODIS). We calculated site- and PFT-specific scaling factors to correct NDVI C values and recommend the use of site-specific NDVI from MODIS in order to scale NDVI C . We also compared G CC extracted from red-green-blue images to NDVI C and found PFT-dependent systematic differences in their seasonalities. During senescence, NDVI C lags behind G CC in deciduous broad-leaf forests and grasslands, suggesting that G CC is more sensitive to changes in leaf color and NDVI C is more sensitive to changes in leaf area. In evergreen forests, NDVI C peaks later than G CC in spring, probably tracking the processes of shoot elongation and new needle formation. Both G CC and NDVI C can be used as validation tools for the MODIS Land Cover Dynamics Product (MCD12Q2) for deciduous broad-leaf spring phenology, whereas NDVI C is more comparable than G CC with autumn phenology derived from MODIS. For evergreen forests, we found a poor relationship between MCD12Q2 and camera-derived phenology, highlighting the need for more work to better characterize the seasonality of both canopy structure and leaf biochemistry in those ecosystems. Our results demonstrate that NDVI C is in excellent agreement with NDVI obtained from spectral measurements, and that NDVI C and G CC can complement each other in describing ecosystem phenology. Additionally, NDVI C allows the detection of structural changes in the canopy that cannot be detected by visible-wavelength imagery. [ABSTRACT FROM AUTHOR]

Canopy color and structure can strongly reflect plant functions. Color characteristics and plant height as well as canopy breadth are important aspects of the canopy phenotype of soybean plants. High-throughput phenotyping systems with imaging capabilities providing color and depth information can rapidly acquire data of soybean plants, making it possible to quantify and monitor soybean canopy development. The goal of this study was to develop a 3D imaging approach to quantitatively analyze soybean canopy development under natural light conditions. Thus, a Kinect sensor-based high-throughput phenotyping (HTP) platform was developed for soybean plant phenotyping. To calculate color traits accurately, the distortion phenomenon of color images was first registered in accordance with the principle of three primary colors and color constancy. Then, the registered color images were applied to depth images for the reconstruction of the colorized three-dimensional canopy structure. Furthermore, the 3D point cloud of soybean canopies was extracted from the background according to adjusted threshold, and each area of individual potted soybean plants in the depth images was segmented for the calculation of phenotypic traits. Finally, color indices, plant height and canopy breadth were assessed based on 3D point cloud of soybean canopies. The results showed that the maximum error of registration for the R, G, and B bands in the dataset was 1.26%, 1.09%, and 0.75%, respectively. Correlation analysis between the sensors and manual measurements yielded R2 values of 0.99, 0.89, and 0.89 for plant height, canopy breadth in the west-east (W−E) direction, and canopy breadth in the north-south (N−S) direction, and R2 values of 0.82, 0.79, and 0.80 for color indices h, s, and i, respectively. Given these results, the proposed approaches provide new opportunities for the identification of the quantitative traits that control canopy structure in genetic/genomic studies or for soybean yield prediction in breeding programs.

The conditions for obtaining and the rules for changing the color indices of ceramic pigments in the system CaO-MgO-AlO-SiO-CrO are established. The main phase of such pigments is chromium garnet, formed with the direct participation of blast-furnace slag minerals. It is shown that as the acidity of pigment batches is increased by equimolecular substitution of free silicon dioxide in their composition based on phosphorus oxide (V) the purity and intensity of the green color of uvarovite pigments intensifies and the firing temperature of the pigments increases to 1100 - 1150°C. [ABSTRACT FROM AUTHOR]

In this study, hazelnut kernels were dried in an infrared dryer with microwave pretreatment. To determine the optimization conditions of the hazelnut samples, response surface methodology and central composite design were used to investigate the effect of temperature levels (45, 65 and 85 ° C), infrared power levels (500, 1000 and 1500 W) and microwave power levels (270, 450 and 630 W) on drying of hazelnut kernels. The adequacy and accuracy of the fitted models (Lack of Fit and R2 ) were checked with analysis of variance (ANOVA). Response surfaces and contour plots were created to show the interaction between the independent and the response variables. Based on the experiments, the optimum conditions for the highest values of effective moisture diffusivity and L* (color index) and the lowest values of consumption energy, shrinkage and a* , b* (color indices) were determined at air temperature of 45°C, microwave power of 470.86 W and infrared power of 1316.72 W. The optimum values of the response variables affecting the effective moisture diffusivity, consumption energy, shrinkage, L*, a* and b* were obtained 2.35×10-9 m 2 s-1, 2.65 kWh, 12.94%, 54.10, 14.97 and 16.70, respectively. [ABSTRACT FROM AUTHOR]

Space Technology provides a resourceful-cost effective means to assess soil nutrients essential for soil management plan. Soil organic matter (SOM) is one of valuable controlling productivity of crops by providing nutrient in farming systems. Geospatial modeling of soil organic matter is essential if there is unavailability of soil test laboratories and its strong spatial correlation. In the present analysis, soil organic matter is modeled from satellite image derived spectral color indices. Brightness Index (BI), Coloration Index (CI), Hue Index (HI), Redness Index (RI) and Saturation Index (SI) were calculated by converting DN value to radiance and radiance to reflectance from Thematic Mapper image. Geospatial model was developed by regressing SOM with color indices and producing multiple regression model using stepwise regression technique. The multiple regression equation between SOM and spectral indices was significant with R = 0. 56 at 95% confidence level. The resulting MLR equation was then used for the spatial prediction for the entire study area. Redness Index was found higher significance in estimating the SOM. It was used to predict SOM as auxiliary variables using cokringing spatial interpolation technique. It was tested in seven VDCs of Chitwan district of Nepal using Thematic Mapper remotely sensed data. SOM was found to be measured ranging from 0.15% to 4.75 %, with a mean of 2.24 %. Remotely sensed data derived spectral color indices have the potential as useful auxiliary variables for estimating SOM content to generate soil fertility management plans. [ABSTRACT FROM AUTHOR]

To study paleoenvironmental and paleoclimatic changes in loess-paleosol sequences (LPS), most proxies except for screening parameters have often been applied at low sampling density, typically 1-2 per stratigraphic unit. This might lead to results that overlook paleovegetation effects that were not only restricted to paleosols but also affected underlying loess material. Here, a new profile was investigated in the loess-paleosol sequence (LPS) at Nussloch, SW Germany using a high resolution multi-proxy approach to improve our understanding of the Late Pleistocene record which serves as a standard sequence in Central Europe. This approach included several geophysical and geochemical parameters, as well as frequencies of root-related features. Grain size distribution and OSL dating enabled correlation of the new section with the nearby standard profile P4, revealing considerable variations of the thickness of stratigraphic units due to local small-scale variations in depositional conditions and paleogeomorphology of longitudinal greda structures. Magnetic susceptibility revealed weathering of the entire LPS under more humid conditions than those described for SE European and Chinese LPS. It further enabled a rough differentiation between an interval that was influenced by pedogenic processes (Lower Pleniglacial to lower part of the Upper Pleniglacial), and loess that was not markedly affected by soil formation. Color measurements confirmed these results and enabled the identification of several paleosols in the Upper Pleniglacial. For the uppermost part of the LPS, low magnetic susceptibility and inorganic geochemical parameters such as low Fe/Ti ratios indicated only weak or no pedogenic influence. In contrast, considerable variations e.g. in carbonatic carbon contents and organic carbon/nitrogen (C/N) ratio might be related to the high frequency of calcified root remains (up to 200rhizolithsm-2 and up to 12,500microrhizolithsm-2) in certain depth intervals of the LPS, entailing incorporation and degradation of organic matter. Frequencies of biopores, which are suggested to derive largely from former root growth and, to a lesser extent, from insect and earthworm bioturbation, were related to paleosols, and thus confirmed the pedostratigraphy. An improved assessment of terrestrial sedimentary archives can be achieved by high-resolution multi-proxy analysis and three-dimensional investigation of terrestrial sediments that are prone to bioturbation. [ABSTRACT FROM AUTHOR]

The effect of drying temperatures on the profile of volatile compounds of pasta was studied. The solid phase microextraction coupled with gas chromatography/mass spectrometry allowed to identify 72 volatile compounds in the samples of not-dried, low-temperature-dried (LT-dried), high-temperature-dried (HT-dried), and wrongly very-high-temperature-dried (WVHT-dried) pastas. The samples of not-dried pasta contained alcohols, aldehydes, short-chain ketones, esters, furans, and some sulfur compounds. In the LT-dried pasta, the volatile aldehydes derived from lipid oxidation were more abundant than in HT-dried pasta. HT-dried pasta showed higher levels of furan and furan derivatives (especially 2-furanmethanol), derived from the Maillard reaction, than LT-dried pasta ( p < 0.05). Pyrazines arose from WVHT treatment. Significant differences were observed also for the color indices when comparing pasta subjected to LT and HT drying ( p < 0.001). Several volatile Maillard reaction products were significantly correlated ( p < 0.05 and p < 0.01) to a* and 100 − L*. The ratio aldehydes/furans allowed distinguishing in a significant way the treatments, independently from the lot characteristics. [ABSTRACT FROM AUTHOR]

The drying process of pasta plays a crucial role in assuring its final quality, since the operational conditions of this process may imply thermal and mechanical damage that also affect final product yield. In this work, independent analyses on furosine, carbohydrates, and color indices (red, yellow, and lightness) have been conducted on pasta samples produced by an Italian pasta factory in order to correlate the examined parameters with pasta drying process. The investigation has been focused on pasta samples having different shapes in order to evaluate how the considered parameters are affected by the specific thermal process scheduled for each pasta format. The same analyses were also performed on semolina used for each pasta sample production, with the aim of verifying whether furosine amount, color indices, and maltulose change in relationship with Maillard reaction (MR) occurring during the drying process. Maltulose presence has been evaluated in semolina for the first time. In addition, the study has been extended to commercial pasta samples of different qualities; a Principal Component Analysis (PCA) has also been conducted to combine together all observed data with the aim of proposing an overall quality index. Finally, a statistical model based on chemical and color parameters as independent variables was successfully developed ( R = 0.990) by means of a multiple linear regression (MLR) analysis to predict commercial pasta cook values and drying cycles as consequences. [ABSTRACT FROM AUTHOR]

Abstract: Fall biological processes are driven by a combination of environmental factors, with cumulative effects over the length of the growing season, which are currently difficult to model. This study evaluated if leaf color change in fall (i.e., leaf yellowing) and brook trout spawning could be two biological processes that are synchronized at a regional scale and if leaf yellowing could be used to determine the peak of spawning activity of this species. To this end, we surveyed 551 brook trout redds and examined 193 digital images of forest trees in the Laurentides Wildlife Reserve (Québec, Canada) over the fall season. Results showed that leaf yellowing and brook trout spawning were synchronized, providing one of the first examples of temporal matching between freshwater and terrestrial biological processes at the regional scale. Considering the difficulty of monitoring the phenology of freshwater fish spawning at high spatial and temporal resolution, terrestrial integrators of environmental conditions, such as leaf color change, may prove to be promising predictors of spawning activity in the management of fish populations. [Copyright &y& Elsevier]

Abstract: Non-destructive characterization of crop canopy is important to acquire timely and inexpensive information for crop management and yield prediction. The objective of the present study was to construct a non-destructive method for monitoring crop growth and nitrogen (N) nutrition status with digital camera image analysis. Digital images of rice canopies grown with four cultivars under various nitrogen treatments were captured by a digital camera periodically before heading stage and at the same time rice plants were sampled to measure LAI, shoot dry weight, and shoot N accumulation in 2006, 2007, and 2009. Canopy cover (CC) and ten color indices were calculated from digital camera images using image analysis program developed in Visual Basic version 6.0. More than eight color indices and CC showed significant correlations with growth and N nutrition parameters like LAI, shoot dry weight, and shoot N accumulation. CC revealed the highest correlations with all of them. CC expressed a curve-linear relationship with LAI, shoot dry weight, and shoot N accumulation (X‘s), being well fitted to a negative exponential function: CC=CCmax {1−EXP (−k X)} with asymptote (CCmax) of unity. However, the nonlinear relationship of CC with LAI and shoot N accumulation except shoot dry weight was statistically different among rice cultivars. The statistically different relationships of CC with all the three parameters were found among N fertilization levels as k values increase with the increase of N fertilization level. To compensate the effects of rice cultivar and N level, stepwise multiple linear regression (SMLR) models including nonlinear relationship of CC and color indices were calibrated and validated. The selected SMLR models for LAI, shoot dry weight, and shoot N accumulation showed better performance than the models using only CC as a predictor variable. The selected SMLR models for LAI, shoot dry weight, and shoot N accumulation showed acceptable precision and its accuracy, indicating that conventional color digital camera could be employed for characterizing the growth and N nutrition status of rice non-destructively. [Copyright &y& Elsevier]

The presence of convective and turbulent motions, and the evolution of magnetic fields give rise to existence of temperature fluctuations in stellar atmospheres, active galactic nuclei and other cosmic objects. We observe the time and surface averaged radiation fluxes from these objects. These fluxes depend on both the mean temperature and averaged temperature fluctuations. The usual photosphere models do not take into account the temperature fluctuations and use only the distribution of the mean temperature into surface layers of stars. We investigate how the temperature fluctuations change the spectra in continuum assuming that the degree of fluctuations (the ratio of mean temperature fluctuation to the mean temperature) is small. We suggest the procedure of calculation of continuum spectra, which takes into account the temperature fluctuations. As a first step one uses the usual model of a photosphere without fluctuations. The observed spectrum is presented as a part depending on mean temperature and the additional part proportional to quadratic value of fluctuation degree. It is shown that for some forms of absorption factor the additional part in Wien's region of spectrum can be evaluated directly from observed spectrum. This part depends on the first and second wavelength derivatives, which can be calculated numerically from the observed spectrum. Our estimates show that the temperature dependence of absorption factors is very important by calculation of continuum spectra corrections. As the examples we present the estimates for a few stars from Pulkovo spectrophotometric catalog and for the Sun. The influence of temperature fluctuations on color indices of observed cosmic objects is also investigated. [ABSTRACT FROM AUTHOR]

We have examined the relationship between the morphological types and the u-r, g-i, and r-z color indices of 365 pairs of galaxies with radial velocities 3000

This article presents both a geometric methodology and an empirical experiment with real plant images to evaluate the performance of different color indices for plant segmentation from two-dimensional digital images. Six well-known color indices given in the literature were selected for the evaluation: the normalized green, the difference between normalized green and normalized red, the normalized difference index, the excessive green index, the modified excessive green index, and the hue. Segmentation performance was assessed on the normalized green-red plane (the rg plane) by using Type I and Type II errors, commonly used in statistics to estimate the errors associated with null hypothesis testing. The two errors were applied in this study to quantifying the misclassified pixel percentages for plant and background, respectively. The rg plane is shown to facilitate visualizing geometrically the behavior of the color indices. An experiment with 240 digital images of four plant types under different lighting and background conditions was carried out to empirically investigate their segmentation performance. Segmentation results showed that the hue achieved the least amount of Type II error with a small loss of plant pixels, which confirms expectations from the geometric analysis on the rg plane. [ABSTRACT FROM AUTHOR]

Abstract: The continuous and automated monitoring of canopy phenology is of increasing scientific interest for the multiple implications of vegetation dynamics on ecosystem carbon and energy fluxes. For this purpose we evaluated the applicability of digital camera imagery for monitoring and modeling phenology and physiology of a subalpine grassland over the 2009 and 2010 growing seasons. We tested the relationships between color indices (i.e. the algebraic combinations of RGB brightness levels) tracking canopy greenness extracted from repeated digital images against field measurements of green and total biomass, leaf area index (LAI), greenness visual estimation, vegetation indices computed from continuous spectroradiometric measurements and CO2 fluxes observed with the eddy covariance technique. A strong relationship was found between canopy greenness and (i) structural parameters (i.e., LAI) and (ii) canopy photosynthesis (i.e. Gross Primary Production; GPP). Color indices were also well correlated with vegetation indices typically used for monitoring landscape phenology from satellite, suggesting that digital repeat photography provides high-quality ground data for evaluation of satellite phenology products. We demonstrate that by using canopy greenness we can refine phenological models (Growing Season Index, GSI) by describing canopy development and considering the role of ecological factors (e.g., snow, temperature and photoperiod) controlling grassland phenology. Moreover, we show that canopy greenness combined with radiation use efficiency (RUE) obtained from spectral indices related to photochemistry (i.e., scaled Photochemical Reflectance Index) or meteorology (i.e., MOD17 RUE) can be used to predict daily GPP. Building on previous work that has demonstrated that seasonal variation in the structure and function of plant canopies can be quantified using digital camera imagery, we have highlighted the potential use of these data for the development and parameterization of phenological and RUE models, and thus point toward an extension of the proposed methodologies to the dataset collected within PhenoCam Network. [Copyright &y& Elsevier]

Abstract: We present the results of absolute photometry – the absolute brightness H V , the effective diameter, (B)VR color indices, composite light curves, period of rotation and amplitude of variations – of several small asteroids in the inner main-belt: 1344 Caubeta, 1401 Lavonne, 2947 Kippenhahn, 3913 Chemin, 3956 Caspar, 4375 Kiyomori, 4555 1987 QL, 5484 Inoda, 5985 1942 RJ, 6949 Zissell and main-belt asteroid 6867 Kuwano. The photometric observations of these objects were made in the period 2007–2009 as part of a project of photometric studies of small main-belt asteroids that involves a collaboration of a number of asteroid photometrists around the world. [Copyright &y& Elsevier]

The design of proxy techniques is an innovative tool to monitor the potentially toxic elements of pollution in road dust. This study evaluated the use of road dust color as a proxy methodology to identify samples contaminated with presumably contaminating elements. FRX determined the concentrations of Fe, Ti, Rb, Sr, Y, Cu, Zn, and Pb in eighty-five road dust samples. The appliance of the RGB system and the Munsell color cards identified five color groups of road dust samples. The discriminant analysis validated these groups by colorimetric indices and presumably contaminating elements. The "very dark gray" color of road dust contains the highest concentrations of Pb, Cu, Zn, and Y. The redness and saturation rates showed high correlations with presumably contaminating elements in "dark gray" and "very dark gray" color samples. The color of road dust, as a proxy technique, allows identifying samples contaminated with presumably contaminating elements. [ABSTRACT FROM AUTHOR]

Canopy color and structure can strongly reflect plant functions. Color characteristics and plant height as well as canopy breadth are important aspects of the canopy phenotype of soybean plants. High-throughput phenotyping systems with imaging capabilities providing color and depth information can rapidly acquire data of soybean plants, making it possible to quantify and monitor soybean canopy development. The goal of this study was to develop a 3D imaging approach to quantitatively analyze soybean canopy development under natural light conditions. Thus, a Kinect sensor-based high-throughput phenotyping (HTP) platform was developed for soybean plant phenotyping. To calculate color traits accurately, the distortion phenomenon of color images was first registered in accordance with the principle of three primary colors and color constancy. Then, the registered color images were applied to depth images for the reconstruction of the colorized three-dimensional canopy structure. Furthermore, the 3D point cloud of soybean canopies was extracted from the background according to adjusted threshold, and each area of individual potted soybean plants in the depth images was segmented for the calculation of phenotypic traits. Finally, color indices, plant height and canopy breadth were assessed based on 3D point cloud of soybean canopies. The results showed that the maximum error of registration for the R, G, and B bands in the dataset was 1.26%, 1.09%, and 0.75%, respectively. Correlation analysis between the sensors and manual measurements yielded R2 values of 0.99, 0.89, and 0.89 for plant height, canopy breadth in the west-east (W–E) direction, and canopy breadth in the north-south (N–S) direction, and R2 values of 0.82, 0.79, and 0.80 for color indices h, s, and i, respectively. Given these results, the proposed approaches provide new opportunities for the identification of the quantitative traits that control canopy structure in genetic/genomic studies or for soybean yield prediction in breeding programs. [ABSTRACT FROM AUTHOR]