Conducting hyperspectral imaging of fruit' entire surfaces while simultaneously evaluating their physical properties, such as volume and mass, can provide a richer dataset for comprehensive fruit ...classification. For this purpose, a fruit grading system using 3D hyperspectral full-surface images is developed, which is based on multi-view imaging of mirrors in the hardware structure design and relies on the virtual volume intersection (VI) algorithm and texture technology in software design. During the design process, a mathematical model for the mirror layout and system geometry parameters is established to determine the system's layout for scanning the entire surface of the sample. In practical applications, a prototype with 28 channels ranging from 400 to 1000 nm is developed for pear samples based on a sub-component control system, a spherical-cap cavity with flashing multi-color LEDs, and multiple side mirrors. The results obtained from this prototype reveal that the predicted volume (R2=96.18%) and mass (R2=98.18%) exhibit a high correlation with measured results and the hyperspectral data between bruised and normal pears is a significant difference. A dataset of pears of three qualities (large, small, and bruised) is prepared for comprehensive classification and resulting in an effective grading (95.33%), which shows that the proposed system is a potential solution for comprehensive fruit quality classification.
•Building a mathematical model related to system structural parameters for layout.•Simultaneous hyperspectral detection and geometric physical property estimation.•The entire fruit surface can be identified using full-view 3D hyperspectral images.•Volume (R²=96.18%) and mass (R²=98.18%) show excellent correlation.•The classification accuracy of large, medium, and bruised pears can reach 95.33%.
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•Growth and biochemical changes under different light qualities were investigated.•Reflector coat improve illumination in PBR and enhanced growth than FLs.•Additional reflector ...support can reduce self shading in culture and reduce culture days.•Blue and green illumination enhanced lipid production.
Silver tinted multi-folded reflector sheet was additionally used in the newly designed LED-PBR setup to study the growth performances and resultant lipid production in Chlamydomonas reinhardtii. The experiment was also carried out to compare the algal growth under various LED light qualities with a white fluorescent lamp (FLs). The synergistic effect of the direct and reflected light provided more efficiency and light penetration that improved the cell concentration (77.5 × 106 cells mL−1), specific growth rate (0.514 d−1), total pigments (12.876 ± 0.673 mg L−1) and lipid content (39.4%) of C. reinhardtii under blue illumination than FLs. Interestingly, green light exhibited remarkable changes in lipid content (27.9%) on the 10 d of cultivation than white, red and FLs. Nile red analysis of neutral accumulation and FTIR analysis of fatty acid contents of C. reinhardtii under different light condition significantly varied. This modified RC-PBR setup can be utilized to increase the light intensity in algal culture and thereby minimize energy consumption and culture duration compared to FLs.
•Sonophotocatalytic degradation of TB and VS at 25min of irradiation and sonication time.•Sonochemical assisted solvothermal synthesis of Ag3PO4/Bi2S3-HKUST-1-MOF.•Synergistic index (2.23) indicated ...that combined system has a positive effect on degradation efficiency.•Combined of ultrasound irradiation and photocatalysis have higher efficiency compared with sum of the individual processes.
An efficient simultaneous sonophotocatalytic degradation of trypan blue (TB) and vesuvine (VS) using Ag3PO4/Bi2S3-HKUST-1-MOF as a novel visible light active photocatalyst was carried out successfully in a continuous flow-loop reactor equipped to blue LED light. Ag3PO4/Bi2S3-HKUST-1-MOF with activation ability under blue light illumination was synthesized and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), photoluminescence (PL) and diffuse reflectance spectra (DRS). The effect of operational parameters such as the initial TB and VS concentration (5–45mg/L), flow rate (30–110mL/min), irradiation and sonication time (10–30min), pH (3–11) and photocatalyst dosage (0.15–0.35g/L) has been investigated and optimized using central composite design (CCD) combined with desirability function (DF). Maximum sonophotodegradation percentage (98.44% and 99.36% for TB and VS, respectively) was found at optimum condition set as: 25mg/L of each dye, 70mL/min of solution flow rate, 25min of irradiation and sonication time, pH 6 and 0.25g/L of photocatalyst dosage. At optimum conditions, synergistic index value was obtained 2.53 that indicated the hybrid systems including ultrasound irradiation and photocatalysis have higher efficiency compared with sum of the individual processes.
The piezoelectric field promotes the separation of photo-generated charges in Bi2WO6 excited by low-power white LEDs, and the produced ROS (OH, O2−) by the synergetic photopiezocatalysis effect of ...Bi2WO6 can efficiently degrade organic pollutants.
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Photocatalysis technology has been proved to be a potential strategy for removal of organic dyes, however high-power light sources are generally necessary to initiate photocatalytic reaction. In this work, we employed an excellent photocatalyst of Bi2WO6 with visible light harvest and meanwhile an intrinsic ferroelectricity, which realized the efficient degradation of organic dye via the synergetic photopiezocatalysis. Through coupling the illumination by a low-power (9W) LED and the ultrasonic vibration (120W) by an ultrasonic cleaner, the nanoflower-like Bi2WO6 composed of ultrathin nanosheets showed a much more enhanced photopiezocatalysis performance for purification of organic dye than the individual photocatalysis and piezocatalysis. Furthermore, the high mineralization efficiency and the good durability of the Bi2WO6 catalyst were demonstrated. The possible mechanism of photopiezocatalysis was finally proposed, where the ultrasound-induced piezoelectric field in Bi2WO6 drove photo-generated electrons and holes to diffuse along opposite directions, consequently promoting the separation efficiency of charge carriers. This work indicates that the synergetic photopiezocatalysis by coupling irradiation and ultrasonic vibration is a promising strategy to purify organic pollutants in wastewater.
In this paper, we demonstrate a cost effective set-up for transport of intensity equation (TIE)-based single-shot phase imaging. A Michelson interferometer like set-up has been utilized for optical ...implementation with light emitting diode as a light source. The mirrors used in the set-up are slightly tilted to obtain the two laterally separated defocused images as single-shot to the intensity-recording sensor. The experimental set-up does not require any costly optical instrument/module such as spatial light modulator. The experimental demonstration has been carried out with a micro-lens array. The adopted TIE algorithm has been verified with the simulation results of quadrature phase function.
•This demonstrates a cost effective set-up for TIE-based single-shot phase imaging.•It uses LED source to avoid speckle problem.•A Michelson interferometer like set-up has been utilized for optical implementation.•The experimental demonstration has been carried out with a micro-lens array.
Artificial light at night (ALAN) is a globally widespread phenomenon potentially affecting ecosystem processes, such as leaf litter breakdown, which is a source of organic matter in fresh waters. ...Here, we conducted a long-term experiment to test the effects of ALAN (2 lx) differing in spectral composition: white LEDs and high pressure sodium lamps (HPS) on leaf consumption, growth and activity of two macroinvertebrate species of shredders: Gammarus jazdzewskii and Dikerogammarus villosus (Crustacea, Amphipoda), compared to the undisturbed light-dark cycle. We also tested if the nocturnal illumination would influence the algal community colonising leaves, which is an important component of the leaf-shredder diet. We found that LED light increased the consumption of leaves by both species, which was nearly twice as high as in other treatments, and supressed the growth rate of G. jazdzewskii, whereas the growth of D. villosus was not affected by either light type. Moreover, D. villosus reduced its activity when exposed to ALAN of both types. As ALAN-induced changes in shredder growth and consumption were not associated with their increased activity or decreased food quality, we suggest that LED light may be a source of physiological stress for shredders, raising their energy expenditure, which was compensated by increased food intake. We have shown that LED illumination induces greater effects on wildlife than alternative, narrow wavelength spectrum light sources, such as HPS lamps, and may potentially alter the litter breakdown in aquatic ecosystems. It may accelerate the turnover of leaves by shredders, but on the other hand, it may negatively affect the fitness of macroinvertebrates and thus disturb the leaf processing over a longer term.
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•Impact of artificial light at night (ALAN) on aquatic invertebrate shredders•Broad spectrum LED light reduces shredder growth and activity, enhances consumption.•Narrow spectrum high pressure sodium (HPS) light has lower impact on the shredders.•LED light may alter the litter breakdown in aquatic ecosystems.•ALAN does not favour the species considered as more tolerant to human impact.
To convert waste CO2 from flue gases of power plants into value-added products, bio-mitigation technologies show promise. In this study, we cultivated a fast-growing species of green microalgae, ...Chlorella vulgaris, in different sizes of photobioreactors (PBRs) and developed a strategy using small doses of sugars for enhancing CO2 sequestration under light-emitting diode illumination. Glucose supplementation at low levels resulted in an increase of photoautotrophic growth-driven biomass generation as well as CO2 capture by 10% and its enhancement corresponded to an increase of supplied photon flux. The utilization of urea instead of nitrate as the sole nitrogen source increased photoautotrophic growth by 14%, but change of nitrogen source didn't compromise glucose-induced enhancement of photoautotrophic growth. The optimized biomass productivity achieved was 30.4% higher than the initial productivity of purely photoautotrophic culture. The major pigments in the obtained algal biomass were found comparable to its photoautotrophic counterpart and a high neutral lipids productivity of 516.6 mg/(L·day) was achieved after optimization. A techno-economic model was also developed, indicating that LED-based PBRs represent a feasible strategy for converting CO2 into value-added algal biomass.
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•Fine-tuning mixotrophic culture of microalgae enhances CO2 bio-fixation.•CO2 capture in sugar-stimulated algal culture enhanced with increased light supply.•Sugar-stimulated algae have as much pigments as its photoautotrophic counterpart.•A techno-economic model evaluates the feasibility of large-scale algae cultivation.
The desire to understand gravitational effects on living things requires the removal of the very factor that determines life on Earth. Unfortunately, the required free-fall conditions that provide ...such conditions are limited to a few seconds unless earth-orbiting platforms are available. Therefore, attempts have been made to create conditions that simulate reduced gravity or gravity-free conditions ever since the gravity effects have been studied. Such conditions depend mostly on rotating devices (aka clinostats) that alter the gravity vector faster than the biological response time or create conditions that compensate sedimentation by fluid dynamics. Although several sophisticated, commercial instruments are available, they are unaffordable to most individual investigators. This article describes important considerations for the design and construction of low cost but versatile instruments that are sturdy, fully programmable, and affordable. The chapter focuses on detailed construction, programming of microcontrollers, versatility, and reliability of the instrument.
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•Magnesiothermic reduction for the synthesis of N-deficient-g-C3N4 (DCN).•Enhanced visible-light-driven photocatalytic RhB degradation.•The catalytic efficiency of DCN is almost six ...times higher than that of bulk g-C3N4.•Providing mechanistic insights into RhB degradation over DCN catalyst.
The N-deficient g-C3N4 (DCN) materials were prepared via a magnesiothermic reduction of g-C3N4, which exhibited significantly enhanced visible-light absorption and photocatalytic performance compared to pristine g-C3N4. In particular, the DCN sample with a g-C3N4:Mg mass ratio of 1:0.2 in the precursor mixture provided the most efficient RhB degradation of over 99%, nearly six-time higher than that of pure g-C3N4. This is attributed to the widened visible-light absorption and efficient separation of generated charge carriers due to the presence of nitrogen vacancies in DCN. A proposed photocatalytic mechanism and the pH effect on rhodamine B photodegradation for DCN were obtained.
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