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A novel method was proposed for the determination of vitamin C (VC) using an infrared camera combined with the iodine-turbidimetric method. Based on the redox between VC and iodine, the residual iodine was measured using the turbidimetric method with an infrared camera to obtain VC content. The light emitted by the infrared light-emitting diode (LE...
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... In digital image analysis, the exclusion of interference is generally based on the selectivity of the sensor or the inuence of interfering ions on the color reaction. 27,42 This study provides a new idea for detecting substance contents using digital image analysis. Extracting feature color images by CD can lter out irrelevant colors and increase the accuracy and antiinterference ability of the model. ...
We propose a feature color extraction method that improves the accuracy of water quality analysis using a digital image and eliminates the effect of interfering ions and chromogenic agents on the color after a color reaction. The proposed method is based on color deconvolution (CD) combined with machine learning for substance measurement in water. After an ordinary camera acquires the solution image after color reaction, the CD algorithm is applied to extract the feature image, calculate the first-order, second-order, and third-order color moments corresponding to RGB channels, and construct a gradient boosting regression tree prediction model based on color moment features to detect substances in water. In predicting ammonia, nitrite, and orthophosphate concentrations, the mean square error values were 0.01029, 0.00063, and 0.1361, and the mean absolute error values were 0.08103, 0.02231, and 0.32886, respectively. There was no significant difference in the results of the comparative spectrophotometric method on the actual water samples. The spiked recoveries of the samples ranged from 94% to 120%, confirming that the method can effectively measure the content of substances in water.
... Image segmentation is recognized as being the most important part of infrared image processing. Infrared (IR) imaging is useful in many applications such as military applications [16,17], industrial applications [18,19], and medical applications [20,21]. Thermal infrared cameras can be used to detect the infrared radiation emitted by the objects [22]. ...
Image thresholding is one of the fastest and most effective methods of detecting objects in infrared images. This paper proposes an infrared image thresholding method based on the functional approximation of the histogram. The one-dimensional histogram of the image is approximated to the transient response of a first-order linear circuit. The threshold value for the image segmentation is formulated using combinational analogues of standard operators and principles from the concept of the transient behavior of the first-order linear circuit. The proposed method is tested on infrared images gathered from the standard databases and the experimental results are compared with the existing state-of-the-art infrared image thresholding methods. We realized through the experimental results that our method is well suited to perform infrared image thresholding.
A simple and eco-friendly microwave method was applied for the preparation of highly fluorescent nitrogen and sulfur co-doped carbon quantum dots (NS-CQDs) and used for the determination of ascorbic acid (ASC) in pharmaceutical dosage forms. The prepared NS-CQDs had bright blue fluorescence at a maximum emission wavelength of 440 nm, after excitation with 350 nm, with a quantum yield of 62.5 %. The developed NS-CQDs were prepared from citric acid and l-cysteine in one minute. The native fluorescence of NS-CQDs was quenched by ferric ions due to the formation of non-fluorescent CQDs/ Fe3+ complex. The quenched fluorescence could be restored by the addition of ASC due to the reducing properties of ASC which converts Fe3+ to Fe2+. The method was found linear over the concentration range of 2.0-100 μg/mL, with a limit of detection was 0.6 μg/mL and a coefficient of determination of 0.9965. The proposed method was cross-validated and statistically compared with a reported HPLC method. The results indicated that the developed method was greener, according to the analytical eco-scale and the green analytical procedure index (GAPI). The prepared NS-CQDs were used for spectrofluorometric determination of ASC in pharmaceutical dosage forms, with percentage recoveries ranging between 98 and 102 %, and relative standard deviations less than 2 %. The method was easy, rapid, reliable, and sensitive and did not require expensive reagents or sophisticated equipment.
Imbalanced water and fertilizer systems have limited the yield and quality of grapes in extremely arid areas. The combined application of organic (OF) and inorganic fertilizers (CF) has been proven to be one of the practical approaches to improving yield and quality. Nevertheless, very few studies have focused on the irrigation amount in organically fertilized and drip-irrigated grapes. Hence, in this study, four combined application ratios of organic and inorganic fertilizers (70%OF + 30%CF, 50%OF + 50%CF, 30%OF + 70%CF, and 0%OF + 100%CF), and four irrigation amounts (630, 675, 720, and 765 mm) were set coupling in a two-year field experiment. Generally, under four irrigation levels, combined organic-inorganic fertilizers increased soil nutrients and improved seedless white grape growth, yield, and quality. The results of the combined fertilizer application treatments showed that the content of available nitrogen (55.97–102.60%), available phosphorus (49.41–124.74%), and available potassium (60.70–124.33%) in soil increased significantly compared with those values under a single application of inorganic fertilizer. In addition, the combined application increased the length of new shoots and leaf midribs (grapes) by 3.16–11.88% and 7.35–15.15%, respectively; this application mode also significantly enhanced transpiration rate (Tr), stomatal conductance (Gs), and net photosynthetic rate (Pn). Furthermore, the grape yield increased by 6.68–19.12%, and the fruit quality notably improved (except for the index of fruit shape). Under the four irrigation amounts, two-year average yields were reported as 17.53, 20.60, 23.31, and 22.71 kg/ha, respectively. Additionally, we used four evaluation methods to assess the fruit quality and compared their correlations with the comprehensive evaluation model. And we concluded that the principal component analysis method (PCA) is best suited for evaluating drip-irrigated grapes’ quality. Then, we applied the PCA to seek proper irrigation management; the results displayed that a suitable irrigation amount of 720 mm and the ratio of organic-inorganic application of 50% organic fertilizer + 50% inorganic fertilizer is recommended. However, further research is required to investigate the effects of soluble and complete organic fertilizers application on drip-irrigated grapes.
