Field rapid determination of soil accessible Cu(Ⅱ) was important for environmental safety and human health risk assessment. In this study, an inexpensive red, green, and blue (RGB) color sensor was ...used for quantitative color difference analysis of the colored solution for soil accessible Cu(Ⅱ) with bis-cyclohexanone oxalydihydrazone as color reagent to develop a new method for analyzing soil accessible under field conditions. First, the calibration curve for RGB color sensor method was established in the standard solutions of Cu(II). Then the “hand shaking + standing” field extraction method for accessible Cu(Ⅱ) was developed. Finally, the method was applied in contaminated soils in the laboratory and in the field, and set the values determined by atomic absorption spectroscopy (AAS) as the standard ones. Results indicated that in the range of 0.1–5 mg L−1 Cu(II), the RGB Euclidean chromogenic difference values were directly linear correlated with the concentration of Cu(II) (R2 > 0.999). The interference of Fe(Ⅲ) and Mn(Ⅱ) could be eliminated by adding citric acid. The “hand shaking + standing” field extraction method could effectively extract the accessible Cu(Ⅱ) from soil with the high extraction rates. The concentrations of accessible Cu(II) in various polluted soils determined by RGB color sensor method were consistent with that determined by AAS, with the relative error within ±5%, the relative standard deviation ≤ 20%. The recovery of Cu(II) in RGB color sensor method was between 97% and 105%, which could meet the requirements of trace analysis of accessible Cu(Ⅱ) in the field. The high accuracy and precision of RGB color sensor method was reconfirmed in the rapid field quantitative assessment of soil accessible Cu(Ⅱ). Due to that the RGB color sensor was low cost, rechargeable, portable, mobile, ambient light resistant, the method would have a great potential for the determination of accessible Cu(Ⅱ) in contaminated soils.
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•Bis-cyclohexanone oxalydihydrazone was used as colorimetric reactant for Cu(II).•Color difference of Cu(II) solutions was linear correlated with its concentration.•Citric acid was used to mask interference of Fe(Ⅲ) and Mn(II) for Cu(II) detection.•“Hand shaking + standing” method can be used to extract accessible Cu(II) in field.•RGB color sensor can be used for measurement of soil accessible Cu(Ⅱ) in field.
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Recently, colorimetric sensors capable of detecting explosive and toxic molecules have attracted much attention for applications in health and environmental monitoring. Here, we demonstrate the ...detection of hydrogen gas using gasochromic fabrics and evaluate their performance with a commercial RGB color sensor module. For this purpose, first a thin Pd film was sputter deposited onto the polyester fabric and then amorphous MoO3 films (several microns) were deposited by RF reactive magnetrons in various O2/Ar ratios (from 2.5 to 12.5 O2). Field emission scanning electron microscope (FESEM) identified the morphological changes of the surface at each coating step and showed that the fibrous structure of the fabrics was preserved after coating of the films, which is suitable for better gas adsorption. Exposure to hydrogen caused the obtained MoO3/Pd/polyester samples to turn blue-gray at room temperature and the UV–Vis spectra showed an increase in optical absorption. Their sensitivity was evaluated in the presence of different H2 concentrations from 250 to 10,000 ppm by recording the time variation of color difference (RGB Euclidean distance). A significant correlation was found between absorption spectrum and RGB analysis with respect to oxygen content. The color variation showed a linear behavior with respect to hydrogen concentration for all samples. Response and recovery times, reversibility and reproducibility in the presence of hydrogen gas were also evaluated using the RGB readout data. Overall, the RGB module optimally depicts the sensing characteristics of the gasochromic fabrics in terms of reversibility, sensitivity and reproducibility, which may contribute to their commercial development.
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•Sputter deposited MoO3/Pd on polyester were explored for gasochromic hydrogen sensing.•RGB color sensor module was used for acquiring color changes.•RGB data showed a linear behavior with respect to hydrogen concentration (250–10,000 ppm).•Significant correlation was found between RGB readout and absorption spectra.•Coloration time, reversibility and reproducibility were also evaluated by RGB data.
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This study uses a backpropagation neural network to determine the evenness of the chayote chip dough. The Tcs3200 Color Sensor mounted on the stirrer alt is used as a sensor to determine the color of ...the chayote emping dough. A regression score of 1 indicates that the input and target data match in the test results of the artificial neural network, which has an objective error (MSE) value of 0.0096306 achieved in the 313th epoch. Changes in RGB color readings on the TCS sensor from min values ??<40 and max values>52 in mixing dough are influenced by distance and light intensity which will be converted in the form of frequency.
Field rapid determination of soil accessible Cr(Ⅵ) is of great significance for on-site assessment and decision-making about the health risks of contaminated sites. When the thickness of solutions ...with various concentrations of Cr(Ⅵ) is constant, there would be a quantitative relationship between the chromogenic difference of Cr(Ⅵ) solutions and the concentration of Cr(Ⅵ). The chromogenic difference could be described by Red (R), Green (G), Blue (B) values. Based on the chromogenic reaction between 1,5-diphenylcarbazide and Cr(Ⅵ), this study first established the calibration curve between the chromogenic difference and the concentration of Cr(Ⅵ) in standard solution with or without 0.01 M CaCl2, using an RGB color sensor. This is the subsequent determination basis of the method for rapidly assessing accessible Cr(Ⅵ) in the field (M-RGB). Then, the concentration of accessible Cr(Ⅵ) of contaminated soil with “hand-shaking + standing” field extraction method was compared with “end-over-end shaking” laboratory extraction method. Finally, the accessible Cr(Ⅵ) of contaminated soil extractants was determined via M-RGB integrating the field extraction method. Results indicated there was a highly significant linear relationship between colorimetric difference value (∆E) and Cr(Ⅵ) concentration in the range of 0.1–3 mg/L (R2 > 0.99, P < 0.01), based on the Euclidean formula for calculating ∆E. The “hand-shaking + standing” field extraction method was effective in obtaining accessible Cr(Ⅵ) extractants with or without 0.01 M CaCl2, with the high extraction efficiency within 100±1%. The concentrations of accessible Cr(Ⅵ) in various polluted soils determined by M-RGB were consistent with that determined by the ultraviolet-visible spectrophotometry, with the relative error within ±5%, and the relative standard deviation ≤ 20%. The spiked recovery experiments showed that the recovery of M-RGB was between 95% and 105%, which means M-RGB could realize the trace analysis for accessible Cr(Ⅵ) in the field.
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•Color difference of Cr(Ⅵ) solutions was linearly correlated with its concentration logarithmic value.•1,5-diphenylcarbazide was used as colorimetric reactant for Cr(Ⅵ).•Hand shaking + standing method can be used to extract accessible Cr(Ⅵ) in the field.•RGB color sensor can be used for rapidly assessing soil accessible Cr(Ⅵ) in the field.
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•Simple and low-cost methods for evaluation of passive samplers for NO2 are described.•Colorimetric evaluation as alternative to photometric determination has been investigated.•Nitrite test-strips ...for reagent-less semi-quantitative evaluation of NO2-passive samplers have been examined.•A RGB-color sensor is proposed for improved detection and evaluation of test strips for nitrite.•Comparison was made of photometric procedures and proposed test strip evaluation for determination of NO2 in ambient air.
Simplified procedures based on photometric and colorimetric detection have been developed and investigated for the determination of nitrite formed in passive sampling of NO2 with triethanolamine as sorptive medium. All procedures basically rely on the common Griess-Ilosvay reaction, but the experimental conditions are different. The variants evaluated are the application of liquid and solid reagents for photometric detection and a commercially available colorimetric test using a sliding color comparator. Furthermore, nitrite test strips were investigated. It was shown that solid reagent addition not only simplifies the analytical procedure but can provide higher sensitivity of the photometric assay. Colorimetric tests are inherently semi-quantitative, but results obtained - considering this restriction - were reliable and have the potential for fast determinations and at-site screening purposes. For the detection of nitrite in combination with passive sampling of NO2 they are attractive for low-budget educational purposes and citizen science projects and can serve for indicative monitoring. As an alternative to common spectrophotometers, an innovative LED-based photometer with WLAN/WIFI interface for smartphone-based data evaluation was investigated as a cheap and mobile-applicable detector for nitrite. Also reported is the development and application of a low-cost purpose-made reflectometer for evaluation of nitrite test strips. The color sensor module of the reflectometer - with light emitted from an inherent white LED - converts the reflected light from the test zone of the strips into RGB values. The relative intensity changes of the green color (complementary to the pink product of the Griess-Ilosvay reaction) can be correlated to the nitrite concentration of the sample solutions enabling improved concentration resolution of test strips compared with visual inspection. Ambient air measurements of NO2 were made and results obtainedof the analytical variants evaluated.
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•Development of a color meter which can quantify the concentration of biomarkers for POCT device applications.•Sensitive detection of total protein on paper based microfluidic device.•Programmable ...handheld device for colorimetric liver function tests.
This paper reports the development and fabrication of a low-cost handheld point of care device that can quantify the concentration of biomarkers using a paper microfluidic assay. The commercially available light-to-digital converting sensor was used to achieve this objective. This RGB sensor was efficient in the digital values of the red, green, and blue components of the sample or object. It has an inbuilt white LED source, an array of photodiodes with color filters, an analog-to-digital converter module, and also an IR blocking filter. The sensor was interfaced with the Arduino UNO board, and the corresponding results were displayed on the serial monitor. This device was tested for manually prepared primary color samples and also for total protein. The colorimetric detection of protein was performed for 1 g dL-1 to 14 g dL-1 concentrations on a paper microfluidic device. The change in color intensity of the paper device with an increase in total protein concentration was monitored and calibrated the device for real sample analysis.
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Seeking an ultra-compact new architecture or strategy to achieve filter-less Red/Green/Blue (RGB) color sensing is critical for developing a wide range of high-resolution, low-cost and flexible color ...discrimination and imaging applications. In this work, a new inversely stacked biomimetic radial junction (RJ) PINIP photodetector, comprising of coaxial multilayers of intrinsic and doped hydrogenated amorphous Si (a-Si:H) thin films coated over silicon nanowires (SiNWs), is demonstrated, which can accomplish bias-selected and tunable spectrum responses to the R, G and B color bands, mimicking the response mechanism in human eyes. Compared to the Bayer matrix sensors, the width of a fundamental RJ-PINIP sensing unit is reduced from ∼3 μm to <500 nm, with an absorber i-layer thinned substantially from ∼1 μm to only ∼50 nm, which is particularly important to achieve a faster photo response and suppress the instability issues in a-Si:H absorber. Notably, the 3D RJ-PINIP sensors can now be easily constructed upon flexible aluminum foils (AF) and operate with a convenient two-terminal connection, which is a prerequisite for scalable matrix device implementation. As a prototype demo, the RGB color sensing and reconstruction functionalities are verified in a 125-RGB color imaging with 520*700 pixels, highlighting their unique potential for developing ultra-compact and flexible RGB imaging applications.
This article presents a color light detection system integrated in 130 nm CMOS technology. The sensors and corresponding electronics detect light in a CIE XYZ color luminosity space using on-chip ...integrated sensors without any additional process steps, high-resolution analog-to-digital converter, and dedicated DSP algorithm. The sensor consists of a set of laterally arranged integrated photodiodes that are partly covered by metal, where color separation between the photodiodes is achieved by lateral carrier diffusion together with wavelength-dependent absorption. A high resolution, hybrid, ∑∆ ADC converts each photo diode's current into a 22-bit digital result, canceling the dark current of the photo diodes. The digital results are further processed by the DSP, which calculates normalized XYZ or RGB color and intensity parameters using linear transformations of the three photo diode responses by multiplication of the data with a transformation matrix, where the coefficients are extracted by training in combination with a pseudo-inverse operation and the least-mean square approximation. The sensor system detects the color light parameters with 22-bit accuracy, consumes less than 60 μA on average at 10 readings per second, and occupies approx. 0.8 mm(2) of silicon area (including three photodiodes and the analog part of the ADC). The DSP is currently implemented on FPGA.
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This article presents a design, modeling, simulation, and measurements of a hybrid photocurrent-to-digital converter integrated together with photo-diodes in a 130nm CMOS process, without any ...additional process steps. Photo-currents of integrated photo-diodes with different responsivities to different wavelength of the light and light intensity are converted into 22-bits digital results in 2ms. The results can then be converted into CIE XYZ or RGB color luminosity space using dedicated DSP algorithm. A high resolution, hybrid, ADC converts light induced photo-currents into 22-bit digital results, canceling the dark current of the photodiodes and 1/f noise and offset voltage of the input stage of the modulator. The whole converter consumes on average less than current at supply voltage at 10 conversions per second. It occupies approx. 0.8mm2 of silicon area, including the three photodiodes, a multiplexer, and the ΣΔ modulator.
•A photocurrent-to-digital converter in 130nm CMOS technology.•Converter includes different photodiodes, the ADC and DSP.•The spectral responsivity of different photo-diodes is achieved through the layout.•The circuits eliminates dark current of a photo-diodes and offset voltage and 1/f noise of the amplifier.•Clock jitter influence is reduced using FIR-DAC filter.
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10.
IoT to inculcate Smart Farming and Soil Nutrient Retention Kukreja, Gagandeep Singh; Bagyaveereswaran, V.; Menon, Siddhartha ...
2021 International Conference on Innovative Computing, Intelligent Communication and Smart Electrical Systems (ICSES),
2021-Sept.-24
Conference Proceeding
The humongous growth in technology has opened new and innovative doors for agriculture and made it more significant and popular. With the advent of technology there is a huge shift towards smart ...farming that will help in meeting the global market demands. More and More companies and researches have been directed towards Internet of Things (IoT) that makes human intervention minimal and thus helps in maneuvering towards increased production, efficiency and meeting huge global market demands. In our project we focus on one of the main elements of a plant growth that is effective nutrient management. Out of the many important nutrient needed for an effective plant growth we focus on the three Macronutrient of utmost importance namely-Nitrogen, Phosphorus and Potassium or NPK. The project involves measuring NPK values, pH level of soil during the preparation and/ or development stages using the RGB color sensor (TCS3200) that performs light intensity absorbed and thus compares the colors against NPK, Moisture sensor that gauges the volumetric content of water within the soil. All these sensors connected to the NodeMCU and the data is transmitted to cloud UI where we analyze it against pre-researched database. We also use an OpenCV plant weed recognition tool to identify the weed growth based on the irregularities in the pattern observed inthe form of pictures or videos. This is done for its effective removal in the initial stages of plant growth to ensure a healthy plant.
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