Blue Research Articles

Microencapsulation of Caucasian blueberries (Vaccinium arctostaphylos L.) anthocyanins: Colour stability in varying storage conditions

AbstractThe aim of this study was to investigate the extraction of anthocyanins from the fruits of Caucasian blueberry (Vaccinium arctostaphylos L.) and examine the colour stability of anthocyanins encapsulated through spray drying in model systems. The trials were conducted to determine the optimal conditions for anthocyanin extraction using an ultrasonic water bath at temperatures of 25, 50 and 75°C. The ideal anthocyanin extraction occurred at 25°C using 100% acetone in an ultrasonic bath for 15 min at 35 kHz. Anthocyanin concentrations were evaluated using the pH differential method. The extracted anthocyanins were encapsulated through spray drying with maltodextrin as the encapsulating material. The encapsulation efficiency was 80.4 ± 0.20%, and the anthocyanin retention rate was 83.0 ± 0.76%. The coloured capsules were added to model systems with pH values of 4.50, 5.00, 5.50 and 6.00. The colour values (L* 50.16 ± 0.05, a* 4.08 ± 0.04, b* −9.35 ± 0.01, H° 293.57 ± 0.15, C* 10.20 ± 0.03) were measured during varying storage conditions. The results showed, that colour loss began on the fifth day and this was accelerated with higher temperatures and pH values. It was found that encapsulation significantly preserved the stability of the blue colour and the loss of the blue colour followed first‐order reaction kinetics. The study showed that the blue colour of microcapsules was best preserved at pH 5.00 at 25°C. In this case, the measured total colour change (∆E) was 5.86, the activation energy (Ea) was 37.64 kJ/mol, and the half‐life (t1/2) was determined to be 19.08 days.

Methods to characterize microplastics: case study on freshwater fishes from a tropical lagoon in Colombia.

Aquatic ecosystems face multiple anthropogenic pressures, and recently plastic pollution is one of the main problems. The Luruaco lagoon receives discharges from streams with high levels of microplastics (MPs) from urban areas that impact the resident ichthyofauna. We studied the prevalence, abundance and physical and chemical characteristics of MPs in fishes in the Luruaco Lagoon, Colombia. Four samplings were carried out where fish were captured with trawl nets. Each individual was assessed for total weight, total and standard length, and then a uroventral cut was made to extract stomach and intestine (GIT). Each structure was weighed, measured, and deposited in glass jars with filtered KOH solution. The abundance of MPs and frequency of occurrence were assessed. A principal component analysis (PCA) was used to describe the variation of the species dataset (%FO, proportion of MPs and their diet). Seven species were recorded and 271 individuals examined: Microplastics were identified in all species, and 1157 particles were found in their GIT, with a prevalence of 87.5% of MPs. Mugil liza and Andinoacara latifrons had a high proportion of MPs. The highest %FO was found in cichlid species. Four typologies and 13 colors of MPs were analyzed; fibers and color blue were predominant. A direct relationship was observed between the type of diet and the proportion and %FO of MPs.

A new target color adaptive graying and segmentation method for gear contact spot detection

Abstract Gear contact spot plays a crucial role in evaluating gear mesh quality. Traditionally, tooth surfaces of gear pairs have been manually brushed with red lead powder and visually inspected after a certain operating period. To enhance detection accuracy and efficiency, computer vision has emerged as an appealing approach for gear contact spot detection. However, determining the graying weights and segmentation threshold poses challenges, particularly in non-ideal illumination environments. To address this problem, this paper proposes a new target color adaptive graying and segmentation (TC-AGS) method for the gear contact spot detection. With the proposed method, the illumination scene is firstly distinguished by the blue color component weight due to its high sensitivity to illumination intensity. Then, an improved adaptively graying algorithm for target color is employed to determine the graying weights for RGB, ensuring the maximum proportion of the desired red color. Finally, either a global threshold method or a local threshold method is selected for image segmentation and contact spot detection according to the illumination intensity. To validate the effectiveness of the proposed method, comprehensive simulation and experimental tests were conducted. The results demonstrate that the proposed method achieves better gear contact spot detection performance than traditional methods. It exhibits higher extraction accuracy under different illumination environments and even in the presence of blurred image sources.

The Design and Development of Dabujiang Patchwork Embroidery for Modern Bags

Background and Aim: Dabujiang patchwork embroidery, an intangible cultural handicraft with the longest heritage in southern Hunan, has garnered increasing attention in recent years due to its unique characteristics. However, these products are facing a situation of decline because they cannot meet the needs of modern people. The objective of this research article is to design and develop modern bags featuring Dabujiang patchwork embroidery patterns for women in contemporary society. Materials and Methods: This research is a combination of qualitative research and quantitative research. The qualitative research method was used to study the color, pattern, and meaning of characteristics from 54 pieces of 6 theme categories of Dabujiang product pictures. Interview intangible cultural inheritors, designers, bag shop owners, and women consumers to understand modern women's design needs for women's bags. Combining the characteristics of the Dabujiang pattern characteristics with the needs of modern women, the design and development of six new Dabujiang women's bags based on 6 theme categories. Through 424 questionnaires for women to assess the women's favorite new bags and analyze the reasons women like and find out the future trend of women's bag development. Results: The results of the research revealed: 1) The patterns based on the six categories have different symbolic meanings respectively and they are mainly bionic and geometric patterns. The lines are curves, and the layout is generally symmetrical and balanced. 2) There are 11 kinds of common colors and mainly based on the five orthodox colors of Chinese tradition. The main colors are red, blue, yellow, black, and white, representing the five traditional Chinese elements, which extend different meanings. 3) Through interviews find out young women prefer large bags of bag 1 style, the Morandi color scheme, and meanings of happiness, love, career success, luck, wealth, and beauty. Consequently, the researcher designed six bag styles based on bag 1 style and six theme categories to meet the needs of modern women associated with these six meanings. Questionnaire responses from 424 young women showed that 23.58% favored the Phoenix pattern bag style, making it the most preferred among the six new bag designs. This style showcases a phoenix motif in blue, white, and black colors, symbolizing career success. Conclusion: The findings indicate that modern women highly value career success and self-worth, prioritizing independence over traditional roles. This conclusion mainly stems from the transformation of modern women's roles and the awakening of self-awareness. In addition to assuming the role of mother in the family, modern women also play the role of professional women in society, and more and more women regard career success as their pursuit goal. In the context of the changing identity and goals of modern women, the products should be designed that meet the needs of modern women based on their needs, combined with the symbolic meaning of cultural patterns. For future product development, incorporating symbolic patterns that align with the career aspirations of modern young women is recommended.

Synthesis, structure and properties of compounds derived from Kotoite-related structures: A2MB2O6 (A = Zn, Ba, Pb; B = Pb, Ba, Zn, Cu).

A series of compounds with the general formula A2MB2O6 (A = Zn, Ba, Pb; B = Pb, Ba, Zn, Cu) related to the kotoite structure has been prepared employing high-temperature solid state methods. The substitution of transition elements in place of Zn2+ ions resulted in colored compounds. The optical absorption spectra could be explained based on Tanabe-Sugano diagram and allowed d-d transitions. Dielectric studies on Ba2ZnB2O6, (Ba1.5Pb0.5)ZnB2O6, PbZn2B2O6, Pb1.5Zn1.5B2O6, BaZn2B2O6 and Pb2CuB2O6 at room temperature indicate reasonable values at low frequencies, which decrease on increasing frequencies. Magnetic study of synthesized single-phase compounds BaZnCoB2O6 and Pb2CuB2O6 have been performed. The substitution of Eu3+, Tb3+ and Tm3+ in place of Ba2+ in Ba2ZnB2O6, gives rise to the expected emission of red, green and blue colors. Suitable modifications of the different phosphors in Ba2ZnB2O6, resulted in white-light emission in Ba2ZnB2O6. The Pb2CuB2O6 compound was found to be a good catalyst in the ipso-hydroxylation of arylboronic acids.

Systematic characterization of new EBT4 radiochromic films in clinical x-ray beams

Objective. We aim to characterize kinetics of radiation-induced optical density in newly released EBT4 radiochromic films exposed to clinical x-rays. Several film models and batches were evaluated for the film sensitivity, optical signal increasing with time, relative film noise, and minimum detectable limits (MDL).Approach. Radiochromic film pieces from a single batch of EBT3 and three batches of EBT4 were exposed to doses of 77.38 cGy, 386.92 cGy, and 773.84 cGy using a 6 MV x-ray beam. The films were scanned with a flatbed scanner at specific time intervals up to 120 h. The time-series net optical density of red, green and blue colors was corrected for response of the scanner with time and studied to establish the saturation characteristics of film polymerization process. Dose-response from 3.86 cGy to 1935 cGy was also determined for each color. MDL of the films was quantitatively defined as the dose that would double the net optical density of red color above the standard deviation of the residual signal at zero dose. The relative noise characteristics of EBT3 versus EBT4 were studied as a function of time, dose and scanner resolution.Main Results. For doses ≥ 100 cGy, analysis revealed a stability of optical density beyond 48 h post-exposure for EBT3 and EBT4 films. EBT3 films attained 80%-90% of their net optical density at 48 h within minutes of irradiation, compared to 72%-88% for EBT4 films. The rate of growth was slowest for blue color, fastest for red, while green was in between the two. The MDL for EBT4 averaged 15 cGy for three batches, whereas EBT3 films reliably detected doses as low as 8.5 cGy.Significance. Several batches of the new EBT4 film showed slightly lower response compared to its predecessor over 3.86 cGy to 1935 Gy range. For all practical purposes, the post-irradiation growth of polymers ceases between 48 to 60 h for both EBT films. Overall, the EBT4 film exhibited noise characteristics similar to EBT3, except for lower doses where the noise was observed to be higher than its predecessor.

Limited uptake of [14C]Gardenia Blue administered orally in male and female rats and mice.

Gardenia blue (GB), a widely used plant-derived food color is prepared by reaction of genipin, the aglycone of geniposide, with protein hydrolysate. Recent animal studies investigating GB toxicity have indicated blue coloration in the gastrointestinal tract, kidneys and mesenteric lymph nodes in rodents following dietary administration. This study investigated the uptake and disposition of [14C]GB in male and female rats and mice administered 100 or 1000 mg/kg by gavage. [14C]GB was prepared by reaction of [2-14C]genipin with soy protein hydrolysate. Following administration in rats, 14C was eliminated primarily in feces (89-97% of administered dose), exhaled volatile organic chemical (VOC) and CO2 traps contained no radioactivity, and urine contained 0.2-0.4 %. In bile-duct-cannulated rats (100 mg/kg [14C]GB), 0.25% of dose was recovered in bile, and in urine, 0.5%. The percent of the dose absorbed was 0.9%, based on radioactivity in urine, bile, and carcass minus digestive tract contents. The highest level of radioactivity in tissues was in kidney; however renal recovery was low, with only 0.02-0.04% of the dose recovered in kidney. Repeated dosing indicated that 14C accumulated in kidney, and was slowly removed following cessation of dosing, consistent with previous studies, in the absence of any functional or histopathological changes.

Font and background color combinations influence recognition efficiency: A novel method via primary color Euclidean distance and response surface analysis

The readability of human–computer interfaces impacts the users’ visual performance while using electronic devices, which gains inadequate attention. This situation is critical during high-stress conditions such as firefighting, where accurate and fast information processing is critical. This study addresses how font and background color combinations on Liquid Crystal displays (LCDs) affect recognition efficiency. A novel concept, primary color Euclidean distance (PCED), is introduced and testified under a repeated-measures experiment. Three factors were investigated: background color (black, white), font color (red, green, blue), and PCEDs. A total of 24 participants were recruited. Results demonstrate that color combinations with specific PCED values can substantially impact recognition efficiency. By using RSA, this study modelled the response time in a generalized mathematical model, which is response surface analysis. Results showed that blue font colors under a black background showed the longest response time. This study also explored the influence of physical stress on recognition efficiency, revealing a latency of about 100 ms across all color combinations. The findings offer a methodological advancement in understanding the effects of color combinations in digital displays, setting the stage for future research in diverse demographic and technological contexts, including mixed reality.

Morpho butterfly flashiness crucially depends on wing scale curvature.

Morpho butterflies are widely known for their brilliant blue and flashy colours, which are produced by intricate wing scale structures. Not all species display a vibrant structural coloration; some are whitish or even brown. This suggests that there is considerable interspecific variation in wing scale anatomy, pigmentation and flashiness. As evidenced by numerous studies, the optical mechanism that creates the bright structural colours resides in the multilayered ridges of the wing scales, but the interspecific variation in flashiness has so far received little attention. Here, we investigate the wing components that influence the directional wing reflectivity. We therefore selected three species that greatly vary in colour and flashy appearance, Morpho sulkowskyi, M. helenor and M. anaxibia. Applying morphological analyses, (micro-)spectrophotometry and imaging scatterometry on wing pieces and individual wing scales, we demonstrate that wings with flat scales produce highly directional reflections, whereas wings stacked with curved scales scatter light into a wider angular space, resulting in a spatially more diffuse appearance. We thus find that the curvature of the wing scales crucially determines the directionality of Morpho's visual display. We discuss how the visual ecology of Morpho butterflies and environmental conditions can drive the evolution of flashy visual displays.

Two Step Synthesis of Fluorescent Zirconia Oxide Amorphous Nanosheets for highly sensitive detection of a cancer marker

This study has reported the first-ever fluorescent 2D amorphous zirconia nanosheets (ZrO2 NS) synthesis approach and their utilization for the detection of tyrosine. We have reported a novel yet simple approach to the synthesis approach by dissolving ZrCl4 in ethanol followed by the reduction with the use of sodium hydroxide. It is suggested that NaOH partially reduces Zr4+ and for Zr-OH conjugates finally forming ZrO2 sheet structure by Cl− templating due to the high affinity of reduced Zr towards oxygen. The as-synthesized 2D amorphous zirconia nanosheet suspension in ethanol resulted in a blue color fluorescence with an emission maximum of 430 nm. This nanosheet system shows a unique quenching property by tyrosine in both PBS buffer and human blood serum. This system was utilized to develop a fluorometric sensing platform for a cancer biomarker, tyrosine. The system showed firm results in 1-100 nM range with a LOD of 14.9 nM in human blood serum and 8.4 nM in PBS. This study has opened a new insight into utilizing 2D amorphous zirconia nanostructures in a novel way and also it creates a platform for using the 2D amorphous NS as a biosensor to detect cancer markers in the medical and biomedicine fields too.

Computational Investigation and Antimicrobial Activity Prediction of Potential Antiviral Drug

The ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate (S1) was chosen for this investigation due to its important biological and pharmacological activities. Detailed infrared and Raman spectra have been investigated in both theoretical and experimental. Frontier molecular orbitals and the electronic properties of the S1 are explained. The titled compound S1 calculated HOMO-LUMO energy gap is 4.60 eV. In molecular electrostatic potential (MEP) map the NO2 group exhibits a blue color, indicating the presence of nucleophilic sites. The density of state (DOS), non-covalent interaction (NCI), electron localized function (ELF), localized orbital locator (LOL), Mulliken atomic charges, and reactive sites have been investigated. The anti-bacterial, antifungal, antitoxin, antiviral, and antimycobacterial studies have been investigated. The molecular docking investigations of the compound were also conducted. Using the Auto-dock program, the compound S1 molecular docking study has been conducted. The molecular docking study's lowest binding energy is -7.91, -5.62, -6.92, and -5.85 kcal/mol for 4XGK, 4ATO, 3U9G, and 2DP4 respectively.

Photoluminescence Properties of Gold(I)-N-Heterocyclic Carbene Complexes

Gold(I)-N-heterocyclic carbenes (NHCs) complexes have undergone rapid development and developed as useful tools for the design of various scaffolds in diverse applications such as biological, catalytic and photophysical applications. This review covers photoluminescence transition properties of gold complexes containing NHC ligands, which give resulted in high energy emissions with desired blue colour needs for new optical devices, bioimaging and organic light emitting diodes (OLEDs). In addition, the great versatility in the structural morphology of the complexes with aurophilic interactions, provides numerous possibilities in the synthesis of desired luminescence complexes with lifetimes corresponding to a fluorescence or phosphorescence process that depends on the origin of the emissions. Herein, we present an overview on structural and electronic properties of NHC ligand, metal-NHC complexes, gold(I)-NHC complexes and photoluminescence properties reported from various research works.

The effect of the number of syn-gas purification nozzles of the water scrubber method on the characteristics of gasification combustion results

The product of the gasification process contains several impurities, including tar, ash, CO2, and other contaminants. To achieve efficient syngas results, the syngas must undergo a filtration or purification process, which can increase its energy density. The purpose of this study was to determine the effect of the number of purification nozzles on the characteristics of the resulting flame, the duration of the flame produced during the gasification process, and the rate of heat absorption in the water generated from the syngas purification process. The water scrubber method employed in the syngas purification process utilizes an updraft gasification reactor. The biomass used in this study is rubber wood, with a venturi nozzle size of 0.15 mm and a pressure of 0.12 Pa. The tests varied the number of purification nozzles to 2, 3, and 4. The use of 4 nozzles had a significant effect on the combustion characteristics, resulting in a blue flame with a duration of 33 minutes. The configuration with 3 nozzles produced a flame that exhibited a mixture of blue and orange colors, with the blue flame being more dominant, lasting 38.2 minutes. In contrast, the configuration with 2 nozzles resulted in a bluish-red flame, predominantly red in color, with a duration of 45 minutes. The heat absorption rates in the water produced for the configurations with 2, 3, and 4 nozzles were measured at 539 J/s, 449.1 J/s, and 414.62 J/s, respectively.

Large-scale high purity and brightness structural color generation in layered thin film structures via coupled cavity resonance

Abstract Structural colors, resulting from the interaction of light with nanostructured materials rather than pigments, present a promising avenue for diverse applications ranging from ink-free printing to optical anti-counterfeiting. Achieving structural colors with high purity and brightness over large areas and at low costs is beneficial for many practical applications, but still remains a challenge for current designs. Here, we introduce a novel approach to realizing large-scale structural colors in layered thin film structures that are characterized by both high brightness and purity. Unlike conventional designs relying on single Fabry–Pérot cavity resonance, our method leverages coupled resonance between adjacent cavities to achieve sharp and intense transmission peaks with significantly suppressed sideband intensity. We demonstrate this approach by designing and experimentally validating transmission-type red, green, and blue colors using an Ag/SiO2/Ag/SiO2/Ag configuration on fused silica substrate. The measured spectra exhibit narrow resonant linewidths (full width at half maximum ∼60 nm), high peak efficiencies (>40 %), and well-suppressed sideband intensities (∼0 %). In addition, the generated color can be easily tuned by adjusting the thickness of SiO2 layer, and the associated color gamut coverage shows a wider range than many existing standards. Moreover, the proposed design method is versatile and compatible with various choices of dielectric and metallic layers. For instance, we demonstrate the production of angle-robust structural colors by utilizing high-index Ta2O5 as the dielectric layer. Finally, we showcase a series of printed color images based on the proposed structures. The coupled-cavity-resonance architecture presented here successfully mitigates the trade-off between color brightness and purity in conventional layered thin film structures and provides a novel and cost-effective route towards the realization of large-scale and high-performance structural colors.

On the interaction of glucose with ammonium molybdate (Hager-Gawalowsky test)

Glucose is an Analyte. Thus, several tests for its detection in urine have been developed. In the present communication the reaction route of the Hager-Gawalowsky test for glucose is provided. Each step is fully commented and the electron flow is also given. The test is based on the interaction of glucose with ammonium molybdate in neutral medium, a blue colour is produced on heating. The active hydrogen in glucose is removed by the inorganic anion, and the resulting enolate from an enediol reacts with the mono-anion just formed. A hydroxylate is eliminated via open-close of a Mo-O double bond. Hydrion switch forms a second enolate that produces a concerted mechanism affording 2-ketoglucose and molybdenum dioxide by a redox reaction.

Insights into the seasonal variation, distribution, composition and dynamics of microplastics in the Ganga River ecosystem of Varanasi City, Uttar Pradesh, India.

The current study explores the seasonal dynamics of microplastic (MP) pollution in the Ganga River of Varanasi City, Uttar Pradesh, India, focusing on water and sediment samples collected during pre-monsoon and post-monsoon periods. The analysis shows significant variations in MP occurrence, shape dynamics, color distribution, and size composition across diverse sampling sites. During the pre-monsoon season, MP concentrations ranged from 17 to 36 particles/L in water samples and 160 to 312 particles/kg in sediment, indicating a moderate to high level of contamination. Post-monsoon sampling showed higher MP concentrations at most sites, indicating the influence of seasonal hydrological changes on MP distribution. Shifts in MP shape dynamics were observed between seasons, with films, foams, fragments, and filaments showing variable distributions. Similarly, color variations in MPs exhibited site-specific patterns, with white, brown, blue, and other colors being predominant. These findings highlight the diverse sources and compositions of MPs in the river ecosystem, highlighting the complexity of MP pollution dynamics. Polymer-type distributions further elucidated the composition of MPs, with notable contributions from polyethylene terephthalate, rayon, polyester, and polyvinyl chloride. PCA analysis revealed significant shifts in particle size and shape distribution between pre-monsoon and post-monsoon periods in both water and sediment samples, with post-monsoon samples showing an increase in larger particles and filaments. These changes highlighted key factors driving the variance in microplastic contamination across different sites. The prevalence of these polymers features diverse sources of MP pollution, including textiles, packaging materials, and industrial waste. Ongoing monitoring and research are crucial to understanding its sources, distribution, and impact on river ecosystems, essential for protecting aquatic biodiversity and human health.

Antioxidant Activity Test of Tomato Extract Face Mist (Solanum lycopersium L.)

Tomatoes contain compounds that act as natural antioxidants and are useful toward off free radicals. Tomatoes can be used as a basic ingredient in the development of facial cosmetics in the form of face mist. The purpose of this study was to determine the antioxidant activity of face mist tomato extract (Solanum lycopersicum L.). This study used quantitative methods with a descriptive research design. The organoleptic face mist has a yellow color with a distinctive oleum rosae aroma and is liquid. The homogeneity test results show all four homogeneous formulas. pH test results range from 4.71±0.005 to 5.68±0.015. The dry time test results were in the range of 2.39±0.015 – 3.12±0.015 minutes. The color test results on the face mist showed that it was positive for beta-carotene with a blue color. The IC50 value of face mist preparations at F0, F1, F2 and F3 was 208.488 ppm, 124.304 ppm, 73.683 ppm and 56.271 ppm, respectively. F0 face mist preparations are very weak antioxidants, F1 are moderate antioxidants, F2 and F3 are strong antioxidants. From this research can be concluded that the best formula to use F3.

Preparation of ultra-sensitive and selective hydrogen peroxide-based colorimetric sensor using highly exfoliated g-C3N4 nanosheets with peroxidase-like activity.

Ahighly sensitive, portable, rapid, and accurate colorimetricsensing method is presented.It isbased upon exfoliated g-C3N4 nanosheets (E-g-C3N4 NSs), having peroxidase nanozyme-like properties. The as-prepared catalyst (E-g-C3N4 NSs) tends to oxidize the colorless tetramethyl-benzidine (TMB) into oxidized-TMB in the presence of hydrogen peroxide (H2O2) generating adark blue color and corresponding ultraviolet visible-spectral changes following aMichaelis-Menten kinetic. The prepared colorimetric sensor exhibited response within the range 0.001-0.450μM having R2 value of 0.999 and adetective limit (LOD) of 0.15 ± 0.04nM. Furthermore, the sensor also displayed outstanding selectivity, ample stability (10weeks), and excellent practicability in real sample applications. All these outstanding properties were highly attributed to the large surface area with exposed actives sites, high surface energy, and large conductive structure of E-g-C3N4 NSs. For comparison of thecatalytic study, we have also explored the sensing mechanism of B-g-C3N4, using thesame optimized experimental conditions. Resultantly, we concluded that the proposed sensor (E-g-C3N4 NSs) will gain considerable attention for on-site environmental and health monitoring in future endeavor.

Agricultural spray drone deposition, Part 1: Methods for high throughput spray pattern analysis

Abstract Effective pesticide application is dependent on precise and sufficient delivery of active ingredients to targeted pests. Water-sensitive papers (WSP) have been used to estimate the stain coverage, droplet density, droplet size, total spray volume, and other spray quality metrics by analyzing deposit stains using image analysis software. However, due to their expensive cost, WSPs are typically distributed along unidimensional transects at intervals of 0.5 m or more, which comprises 0.5% or less of the total treated area. This might limit the ability to accurately represent the deposition of agricultural sprayers with irregular patterns, such as agricultural drone sprayers in their early development stage. This study introduces a novel approach utilizing white Kraft paper and a blue colorant proxy for assessing spray deposition. A custom Python-based image analysis tool, SprayDAT (Spray Droplet Analysis Tool), was developed and compared to traditional image analysis software, DepositScan. Both models showed increased accuracy in detecting larger objects, with SprayDAT generally performing better for smaller droplets. DepositScan underestimated the total deposited spray volume by up to 2.7 times less compared to the colorant extraction assessed via spectrophotometry and the predicted output based on flow rate, coverage, and speed. Accuracy of software-estimated spray volume declined with increasing total stain coverage, likely due to overlapping stain objects. Droplet density exhibited a Gaussian trend with peak density at approximately 22% stain cover, offering evidence for overlapped stains for both DepositScan and SprayDAT as stain cover increased. Both models showed exponential growth in volumetric median diameter (VMD) with increasing stain cover. SprayDAT is freely accessible through an online repository. It features a user-friendly interface for batch-processing large sets of scanned images and offers versatility for customization to meet individual needs, such as adjusting spread factor, updating the standard curve for spray volume estimation, or modifying the stain detection threshold.

Agricultural spray drone deposition, Part 2: Operational height and nozzle influence pattern uniformity, drift, and weed control

Abstract Agricultural spray drone (ASD) use in managed turfgrass has been given limited attention in the scientific literature. Further, deposition patterns of ASD spray have been obscured in previous research by ambient wind, crop canopy interference, and limited sampling resolution. Using a continuous sampling method involving blue colorant and water sprayed over white Kraft paper that was assessed via digital image analysis of stain objects and referenced spectrophotometric analysis of extractant, deposition metrics were estimated across a 29.3-m transect perpendicular to an ASD or ground sprayer spray swath. The ASD applies very fine droplets that are highly concentrated with herbicide, similar to ultra-low volume treatments, that improved smooth crabgrass [Digitaria ischemum (Schreb.) Schreb. ex Muhl.] control compared to a ground sprayer when the ASD was operated at 2 m above the turf. Unfortunately, these very fine droplets also drift, leading to four times greater droplet density at distance of almost 12 m away from the targeted spray swath following an operational height of 10 m compared to that at 2 m. As ASD operational height increases, drift and effective swath width at 30% coefficient of variation uniformity increases while effective application rate, total deposition, and D. ischemum control by quinclorac herbicide decreased. Total deposition decreased 6% for each m increase in ASD operational height, likely due to evaporation. The potential losses due to evaporation is a serious consideration for ASD use that has received little attention in the scientific literature. Our data suggest that ASD operational height should be as low as possible, but modification of spray systems may be needed to improve homogeneity of spray pattern.