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In recent years, interest in the Moon has grown exponentially, thanks mainly to space programs with strong international cooperation, such as the NASA Artemis program. Several scientific committees have identified the lunar south pole as the region of greatest interest for building a lasting and sustainable human settlement. However, the knowledge we have of this area is still limited. This work aims to provide a general overview of the main physical and morphological features of the lunar south pole and to propose a first iteration of spectroscopic observations within the visible range from the Asiago Astrophysical Observatory, giving a new and different perspective. The objective is to verify the feasibility of an Earth-based spectroscopic survey to detect water and the abundances of other volatiles and elements. [ABSTRACT FROM AUTHOR]

The project of the Visible Spectroscopy diagnostics for the Z eff radial profile measurement and for the divertor visible imaging spectroscopy, designed for the new tokamak DTT (Divertor Tokamak Test), is presented. To deal with the geometrical constraints of DTT and to minimize the diagnostics volume inside the access port, an integrated and compact solution hosting the two systems has been proposed. The Z eff radial profile will be evaluated from the Bremsstrahlung radiation measurement in the visible spectral range, acquiring light along ten Lines of Sight (LoS) in the upper part of the poloidal plane. The plasma emission will be focused on optical fibers, which will carry it to the spectroscopy laboratory. A second equipment, with a single toroidal LoS crossing the plasma centre and laying on the equatorial plane, will measure the average Z eff on a longer path, minimizing the incidental continuum spectrum contaminations by lines/bands emitted from the plasma edge. The divertor imaging system is designed to measure impurity and main gas influxes, to monitor the plasma position and kinetics of impurities, and to follow the plasma detachment evolution. The project aims at obtaining the maximum coverage of the divertor region. The collected light can be shared among different spectrometers and interferential filter devices placed outside the torus hall to easily change their setup. The system is composed of two telescopes, an upper and a lower one, allowing both a perpendicular and a tangential view of the DTT divertor region. This diagnostic offers a unique and compact solution designed to cope the demanding constraints of this next-generation tokamak fusion devices, integrating essential tools for wide-ranging impurity characterization and versatile investigation of divertor physics. [ABSTRACT FROM AUTHOR]

An initial high fluence campaign was performed in WEST, in 2023, on the newly installed actively cooled tungsten divertor composed of ITER-grade monoblocks. The campaign consisted in the repetition of a 60 s long Deuterium L-mode pulse in attached divertor conditions, cumulating over 10000s of plasma exposure. A maximum deuterium fluence of approximately 5⋅1026 m−2 was reached in the outer strike point region, representative of a few high performance ITER pulses. Gross tungsten erosion inferred from visible spectroscopy shows that the most eroded plasma facing component is the inner divertor target with rates ten times larger than on the outer divertor target. The outer midplane tungsten bumpers, located a few centimeters from the plasma, show gross erosion rates two times lower than at the outer divertor. We conclude that the outer midplane bumpers have a negligible contribution to the long range tungsten migration and deposition onto the lower divertor. The cumulated gross erosion rate on the inner divertor translates in an effective gross erosion thickness of about 20μm, while it is about 2μm for the outer divertor. Strikingly, these orderings coincide with the thickness of deposits found locally on the divertor: the exposed surfaces of high field side monoblocks are covered with several tens of μm tungsten deposits, while on the lower field side, few μm thin tungsten deposits are only found on the magnetically shadowed parts of monoblocks. The strong impact of those deposits on WEST operation, namely perturbation of surface temperature measurement with infra-red thermography, and the emission of flakes causing radiative perturbation of the confined plasma, calls for anticipating similar issues in ITER. In particular, the start of research operation shall consider the definition of a divertor erosion budget in order to anticipate the formation of deleterious deposits.

Smartphone-based assays to inspect pesticides in foods have attracted much attention as such assays can transform tedious laboratory-based assays into real-time, on-site, or even home-based assay and hence overcoming the limitations of conventional assays. Although an array of smartphone-based assays is available, information on the use of these assays for pesticides inspection is scattered. The purposes of this review are therefore to compile, summarize and discuss state-of-the-art as well as advantages and limitations of the relevant technologies. Suggestions are provided for further development of smartphone-based assays for rapid inspection of pesticides in foods. Smartphone-based assays relying on enzyme inhibitions are noted to be nonselective qualitative, capable of reporting results in a quantitative manner only when a sample contains an individual pesticide. Smartphone-based assays relying on chemical reactions also target only individual pesticides. Smartphone-based visible spectroscopy can, on the other hand, inspect individual and multiple pesticides with the aid of appropriate colorimetry-, luminescence-, or fluorescence-based assay. Smartphone-based visible-near infrared and Raman spectroscopies are suitable for simultaneous multiple pesticides inspection. Raman spectroscopy is of particular interest as it can detect pesticides even at lower concentrations. This spectroscopic technique can also serve as a real-time assay with the aid of cloud network computations. [ABSTRACT FROM AUTHOR]

This research introduces an approach to visible spectroscopy leveraging image processing techniques and machine learning (ML) algorithms. The methodology involves calculating the hue value of an image and deriving the corresponding dominant wavelength. Initially, a six-degree polynomial regression supervised machine learning model is trained to establish a relationship between the hue values and dominant wavelengths. Subsequently, the ML model is employed to analyse the visible wavelengths emitted by various sources, including sodium vapour, neon lamps, mercury vapour, copper vapour lasers, and helium vapour. The performance of the proposed method is evaluated through error analysis, revealing remarkably low error percentages of 0.04%, 0.01%, 3.7%, 1%, and 0.07% for sodium vapour, neon lamp, copper vapour laser, and helium vapour, respectively. This approach offers a promising avenue for accurate and efficient visible spectroscopy, with potential applications in diverse fields such as material science, environmental monitoring, and biomedical research. This research presents a visible spectroscopy method harnessing image processing and machine learning algorithms. By calculating hue values and identifying dominant wavelengths, the approach demonstrates consistently low error rates across diverse light sources. [ABSTRACT FROM AUTHOR]

In recent years, interest in the Moon has grown exponentially, thanks mainly to space programs with strong international cooperation, such as the NASA Artemis program. Several scientific committees have identified the lunar south pole as the region of greatest interest for building a lasting and sustainable human settlement. However, the knowledge we have of this area is still limited. This work aims to provide a general overview of the main physical and morphological features of the lunar south pole and to propose a first iteration of spectroscopic observations within the visible range from the Asiago Astrophysical Observatory, giving a new and different perspective. The objective is to verify the feasibility of an Earth-based spectroscopic survey to detect water and the abundances of other volatiles and elements.

The degradation of green leaves in autumn after their photosynthetic activities is associated with decreases in chlorophylls and increases in anthocyanins. However, the sequential orders of these processes are not well understood because of a lack of continuous monitoring of leaves in the same positions. Therefore, the senescence processes of Japanese maple (Acer palmatum) leaves were followed daily in the same positions for approximately 60 days using visible spectroscopy with an original handheld visible–near-infrared spectrometer. The obtained reflection spectra were converted to absorption spectra and band areas of chlorophyll a and anthocyanins were determined. Decreases in the chlorophyll a band area with time show two-step exponential decreases corresponding to slow and fast first-order decrease rates. A rapid decrease in chlorophyll a started after an increase in anthocyanin. Therefore, the leaf senescence started through a slow decrease in chlorophyll a (20–30 days), followed by a rapid increase in anthocyanins (~20 days), followed by a rapid decrease in chlorophyll a (10–20 days). The formation of anthocyanins has been proposed to protect leaf cells from losing chlorophylls through solar radiation damage. The obtained sequential changes of pigments support this light screen hypothesis. (199 words < 200 words) [ABSTRACT FROM AUTHOR]

This research introduces an approach to visible spectroscopy leveraging image processing techniques and machine learning (ML) algorithms. The methodology involves calculating the hue value of an image and deriving the corresponding dominant wavelength. Initially, a six-degree polynomial regression supervised machine learning model is trained to establish a relationship between the hue values and dominant wavelengths. Subsequently, the ML model is employed to analyse the visible wavelengths emitted by various sources, including sodium vapour, neon lamps, mercury vapour, copper vapour lasers, and helium vapour. The performance of the proposed method is evaluated through error analysis, revealing remarkably low error percentages of 0.04%, 0.01%, 3.7%, 1%, and 0.07% for sodium vapour, neon lamp, copper vapour laser, and helium vapour, respectively. This approach offers a promising avenue for accurate and efficient visible spectroscopy, with potential applications in diverse fields such as material science, environmental monitoring, and biomedical research. This research presents a visible spectroscopy method harnessing image processing and machine learning algorithms. By calculating hue values and identifying dominant wavelengths, the approach demonstrates consistently low error rates across diverse light sources.

Ink analysis is one of the most important and keydimension of forensic document examination (FDE). It is performed to compare, identify, characterize and discriminate different kinds of inks present on questioned document. It becomes key evidence in forensic document examination. In the present work, thirty-eight blue gel pens are discriminated using visible spectroscopy coupled with chemometric techniques. The recorded spectra were visually compared followed by chemometric techniques of principal component analysis (PCA) and linear discriminant analysis (LDA). Discriminating power for visual comparison, PCA and LDA are 58.18%, 100% and 100% respectively. Developed PCA model is validated and 100% accuracy, precision, sensitivity and specificity are achieved. Blue gel pen inks were 100% correctly differentiated on the basis of their brands using PCA followed by LDA. The utilized approach is fast and provides reproducible results. The results of present work demonstrate that potential utility of conventional and cost-effective visible spectroscopy can be improved by coupling it with these chemometric techniques. Major advantage of present research is the minimum damage caused to document. This study establishes a method which provides proof of concept discrimination of the gel pen samples. The methodology adopted in present work can be applied in the alteration cases in examination of suspected documents. [ABSTRACT FROM AUTHOR]

The article presents a prototype designed for higher education, this prototype is a modular spectrophotometer, which consists of three modules, the first module is the light source, the second module is the cuvette holder in which the electronic transitions occur and in the third module the electronic transitions that occur in the second module are converted into numerical data. This prototype has the advantage of being mobile, it does not become out of calibration, because it uses a set of light emitting diodes (LEDs) as a light source. This prototype measures impedances of a photoresistor, which is affected by the electronic transitions occurring in the second module. This modular spectrophotometer prototype allows us to use it for analytical chemistry by correlating the concentrations of a sample with the impedance of the photoresistor, which is measured with a multimeter. This prototype presents determination coefficients of 0.9993, 0.9990, 0.9989 and 0.9961, respectively for solutions of copper sulfate, potassium permanganate, egg yellow pigment and collagen, these measurements allow us to apply Lambert-Beer law for spectrophotometry. [ABSTRACT FROM AUTHOR]

WEST is an actively cooled, long-pulse tokamak with nearly all plasma-facing components (PFC) made of tungsten (W). One of the aims of WEST is to study plasma operation with W PFCs in preparation for long-pulse operation on W divertor devices like ITER (Bucalossi et al., 2014) [1]. For long-pulse operation, the W impurity content and transport to the core plasma are critical concerns that require further measurement and interpretation in order to improve plasma performance and PFC durability. In low confinement mode (L-mode) operation, the sputtering of tungsten is not expected to be driven by the plasma itself (D), but by the main light impurities (C, B, O, N) observed at trace levels in WEST. Identifying the main W sources and understanding W transport in the SOL are key metrics for plasma performance, which are simulated with Scrape-Off Layer (SOL) impurity transport codes (SOLEDGE-ERO, OEDGE-DIVIMP). Previous studies have used O as proxy for light impurity with a global content varying from 3 to 5% in SOL transport simulations (Genova et al., 2021; Rooij et al., 2020; Klepper et al., 2022) [2–4]. A power scan was performed in a standard WEST magnetic equilibrium with LH injected power up to 5 MW. Density and temperature were measured with flush-mounted Langmuir probes (Dejarnac et al., 2021) [5]. The impurity fluxes are estimated by applying the number of ionizations per photons (S/XB) coefficients calculated with the collisional-radiative model “ColRadPy” (Johnson et al., 2019) [6] to the spectral radiance measured with the WEST visible spectroscopy system (Meyer et al., 2016) [7]. This work details how the low-Z impurity content (C, O) near the divertor target was refined using the visible spectroscopy for several impurity charge states, coupled with ColRadPy to infer the content of all impurity charge states at the divertor. First results shows that the main light impurity is C and not O as originally assumed. This inferred impurity content is then used to evaluate the W sputtering at the divertor, considering the sheath at the divertor. A quantitative comparison is performed with the W flux at the divertor measured with visible spectroscopy that shows a qualitative agreement, but not fully consistent at the strike point position. This, in turn, suggests that the impurity content is not complete with O and C only.

A colorimetric method for the analysis of dolutegravir in pure form and in tablets has been developed based on the formation of green colour complex. The method is based on the diazotization of carbonyl group and coupling with 3-methyl-2-benzothiazolinone hydrazone reagent in presence of ferric chloride to form green colour complex, by reaction of NH2 (amine) group present in the 3-methyl-2-benzothiazolinone hydrazone reagent with the carbonyl functional group of dolutegravir by eliminating one water molecule. The complex exhibited absorption maxima at 632 nm obeying Beer's law in range of 10-18 pg mL-1. This method is simple, precise and accurate with recovery of 99.8-100 %. The line equation Y = 0.0082x + 0.0292 with correlation coefficient (r2) of 0.991 was obtained. [ABSTRACT FROM AUTHOR]

Microanalysis techniques based on resonance Raman and reflection visible spectroscopy have been applied to the characterization of pigments responsible for the blue or violet coloration in flowers; in particular of Lobelia erinus, Campanula portenschlagiana, Cineraria, Viola tricolor, Anemone coronaria, Agapanthus, Platycodon, Salvia farinacea, Plumbago capensis, Ceratostigma plumbaginoides, Commelina communis and Salvia patens. The spectroscopic methods were applied both in vivo on the flower petals and in vitro on extracts obtained through a procedure based on SPE (solid-phase extraction) optimized for minimal quantities of vegetable raw material. Different patterns obtained for the Raman spectra have been correlated, also on the basis of density functional theory (DFT) calculations, with different schemes of substitution of the benzopyrilium nucleus of the anthocyanins and with various possible forms of copigmentation responsible for the stabilization of the blue color. The results obtained were verified by comparison with the analysis of the extracts by HPLC-ESI-MS (liquid chromatography-electrospray ionization-mass spectrometry). [ABSTRACT FROM AUTHOR]

In this study, a portable desktop analyzer for the determination of fat content in milk is introduced. The prototype of the sensor consists of three light-emitting diodes (red, green, and blue) as a light source. The transmitted light is detected by a photoresistor and continuous voltage measurements provided by the microcontroller, and is recorded by a computer. The resulting univariate and multivariate models show that the developed analytical device is capable of determining fat content in raw and homogenized milk with sufficient accuracy.

The degradation of green leaves in autumn after their photosynthetic activities is associated with decreases in chlorophylls and increases in anthocyanins. However, the sequential orders of these processes are not well understood because of a lack of continuous monitoring of leaves in the same positions. Therefore, the senescence processes of Japanese maple (Acer palmatum) leaves were followed daily in the same positions for approximately 60 days using visible spectroscopy with an original handheld visible–near-infrared spectrometer. The obtained reflection spectra were converted to absorption spectra and band areas of chlorophyll a and anthocyanins were determined. Decreases in the chlorophyll a band area with time show two-step exponential decreases corresponding to slow and fast first-order decrease rates. A rapid decrease in chlorophyll a started after an increase in anthocyanin. Therefore, the leaf senescence started through a slow decrease in chlorophyll a (20–30 days), followed by a rapid increase in anthocyanins (~20 days), followed by a rapid decrease in chlorophyll a (10–20 days). The formation of anthocyanins has been proposed to protect leaf cells from losing chlorophylls through solar radiation damage. The obtained sequential changes of pigments support this light screen hypothesis. (199 words < 200 words)

Conductive polymers are nowadays attracting great attention for their peculiar mechanical, electrical and optical proprieties. In particular, PEDOT can be used in a wide range of innovative applications, from electroluminescent devices to photovoltaics. In this work, the electrochemical deposition of 3,4 ethylenedioxythiophene (EDOT) was performed on various substrates (ITO, thin films of gold and palladium on silicon wafers) by means of both potentiostatic and potentiodynamic techniques. This was intended to further expand the applications of electrochemically deposited PEDOT, particularly regarding the preparation of thin films in tight contact with electrode surfaces. This allows one to obtain systems prone to be used as electrodes in stacked devices. Chronoamperometric experiments were performed to study the nucleation and growth process of PEDOT. SEM, ESEM and AFM analysis allowed the characterization of the morphology of the polymeric films obtained. Raman and visible spectroscopy confirmed the high-quality of the coatings on the different substrates. Then, the PEDOT films were used as the base material for the further electrodeposition of a copper layer. In this way, a hybrid electronic device was obtained, by using electrochemical methods only. The high conductivity and ohmic behavior of the device were confirmed over a wide range of frequencies with electrical impedance spectroscopy analysis.

Panax notoginseng powder (PNP) is a widely consumed functional food and has shown promise in cardiovascular protection. However, its high price makes it often a target for economic adulteration. This study aims to build a rapid evaluation method for common adulterants of PNP using near-infrared (NIR) and/or visible (VIS) combined with Bayesian optimized machine learning algorithms. The results showed that the machine learning algorithms combined with a multi-spectra fusion strategy exhibited excellent performance in distinguishing different types of adulterated PNP, especially the deep learning algorithms (ANN and LSTM) with 100 % test accuracy. Furthermore, machine learning algorithms coupled with VIS spectra had an obvious advantage in predicting the proportion of PNP adulteration, with all algorithms having a prediction accuracy R2p of over 0.99. Overall, multi-spectra combined with Bayesian optimized machine learning algorithms enables a rapid and accurate evaluation of PNP adulterants, which can also apply to other foods. [Display omitted] • A rapid and non-destructive method for PNP quality evaluation was established. • BO algorithm was applied for hyperparameter optimization. • NIR - VIS fusion data improved the identification accuracy of adulterated PNP. • ANN and LSTM can achieve 100 % accuracy in identifying PNP adulteration. • VIS has advantage in predicting the adulteration proportion of PNP (R2p> 0.99). [ABSTRACT FROM AUTHOR]

The aim of this study is to compare the optical responses of external beam therapy 3 (EBT3) films exposed to X-rays and solar ultraviolet rays (SUV-rays), as a dose control technique in the clinical sector for various radiation types, energies, and absorbed doses up to 4 Gy. In this study, EBT3 films with three different expiry dates were prepared and cut into pieces of size 2 by 2 cm2. The first group was exposed to 90 kVp X-rays, while the second group was exposed to the SUV-rays at noon. The analysis was performed using a visible Jaz spectrometer and an EPSON Perfection V370 Photo scanner to obtain the absorbance, the net reflective optical density (ROD) and the red-green-blue (RGB) values of the samples. The results have shown that spectroscopic measurements of the exposed expired EBT3 films with these radiation sources are able to produce primary peaks and secondary peaks at λ = 641.74 nm and λ = 585.98 nm for X-rays, and at λ = 637.93 nm and λ = 584.45 nm for SUV-rays, respectively. According to these findings, compared to 2021 films that expired shortly before the trial start date; 2018 films responded better to the absorbed dose than 2016 films when exposed to both X-ray and SUV-rays. In terms of energy dependence, the expired EBT3 2018 had the largest net ROD value. Using L*a*b* indices extracted from the RGB data, and despite that EBT3 films have expiry dates according to the manufacturer; all the films exhibited a substantial colour change, indicating that these films are still usable for clinical and research purposes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the optical response of an expired External Beam Therapy (EBT3) film, which expired in 2018, using X-rays and electron beam doses. The film's optical responses were evaluated for its usability in measuring different radiation sources, energy, and absorbed doses ranging up to 5 Gy. Pieces of the expired EBT3 film were irradiated with 90 kVp, 6 MV X-ray photons, and 6 MeV electron beam. The analysis was performed using the Jaz visible spectrometer and EPSON Perfection V370 Photo scanner to obtain the absorbance and the net relative optical density (ROD) of the film samples respectively. The results showed that spectroscopic measurements of the exposed expired EBT3 films under these radiation sources were able to produce primary secondary peaks at λ = 633.52 nm and λ = 582.3 nm respectively. The best wavelength subsets that presented the best MLR regression fitting for all experiments were 541.48 nm, 561.11 nm, and 600.28 nm. While, for the 6 MV photon and the 6 MeV electron beam they were 600.28 nm, 650.79 nm and 654.10 nm. In case of the irradiation with the 6 MV photon and the 6 MeV electron beam, expired EBT3 film showed no significant differences, which made it suitable for dosimetry in various sources of radiation. The individual calibration of radiation dose produces very high measurement accuracy with coefficient of determination, R2 above 0.99 and root mean square of error, RMSE of 0.038 Gy, 0.113 Gy, and 0.115 Gy for films irradiated with 90 kVp X-rays, 6 MV photon beam, and 6 MeV electron beam respectively. Hence, from the results, the expired EBT3 film used in this study showed promising usability of expired EBT3 films beyond their prescribed expiry dates. [ABSTRACT FROM AUTHOR]

Today, the increasing process of food waste and agricultural products is one of the serious challenges in the most countries, especially in developing countries, so one of the serious policies of governments in the food security is to reduce the waste and maintain the quality of agricultural products. So far, several methods have been used to measure the quality of agricultural products, only some of which are technically and industrially justified. Vis / NIR Spectroscopymethod is one of the methods that has been considered and used in evaluating the qualitative characteristics of agricultural products due to its high speed and accuracy. In this regard, in the present study, visible/near infrared Spectroscopywas used to measure the qualitative changes and classification of K-Lime samples of lemon during the storage period (10, 20 and 30 days). In order to analyze the qualitative characteristics and classify the data extracted from NIR, the pattern recognition methods including principal component analysis (PCA), linear Discriminant analysis (LDA) and support vector machine (SVM) were used. The results showed that Visible/Near Infrared (Vis/NIR) Spectroscopywas able to differentiate its lemon samples based on storage time. Although PCA, LDA and SVM methods were able to classify lemon samples with good accuracy according to qualitative characteristics, but LDA and SVM methods with 100% accuracy had better accuracy and fit. Also, according to the results, the quadratic function has been determined and introduced as the best function for constructing classification models by LDA and SVM methods. [ABSTRACT FROM AUTHOR]

As a result of the development of non-invasive optical spectroscopy, the number of prospective technologies of plant monitoring is growing. Being implemented in devices with different functions and hardware, these technologies are increasingly using the most advanced data processing algorithms, including machine learning and more available computing power each time. Optical spectroscopy is widely used to evaluate plant tissues, diagnose crops, and study the response of plants to biotic and abiotic stress. Spectral methods can also assist in remote and non-invasive assessment of the physiology of photosynthetic biofilms and the impact of plant species on biodiversity and ecosystem stability. The emergence of high-throughput technologies for plant phenotyping and the accompanying need for methods for rapid and non-contact assessment of plant productivity has generated renewed interest in the application of optical spectroscopy in fundamental plant sciences and agriculture. In this perspective paper, starting with a brief overview of the scientific and technological backgrounds of optical spectroscopy and current mainstream techniques and applications, we foresee the future development of this family of optical spectroscopic methodologies. [ABSTRACT FROM AUTHOR]

Civet coffee is considered as highly marketable and rare. This specialty coffee has a special flavor and higher price relative to regular coffee, and it is restricted in supply. Establishing a straightforward and efficient approach to distinguish civet coffee for quality; likewise, consumer protection is fundamental. This study utilized visible spectroscopy as a non-destructive and quick technique to obtain the absorbance, ranging from 450 nm to 650 nm, of the civet coffee and non-civet coffee samples. Overall, 160 samples were analyzed, and the total spectra accumulated was 960. The data gathered from the first 120 samples were fed to the classification learner application and were used as a training data set. The remaining samples were used for testing the classification algorithm. The study shows that civet coffee bean samples have lower absorbance values in visible spectra than non-civet coffee bean samples. The process yields 96.7 % to 100 % classification scores for quadratic discriminant analysis and logistic regression. Among the two classification algorithms, logistic regression generated the fastest training time of 14.050 seconds. The application of visible spectroscopy combined with data mining algorithms is effective in discriminating civet coffee from non-civet coffee.

Microanalysis techniques based on resonance Raman and reflection visible spectroscopy have been applied to the characterization of pigments responsible for the blue or violet coloration in flowers; in particular of Lobelia erinus, Campanula portenschlagiana, Cineraria, Viola tricolor, Anemone coronaria, Agapanthus, Platycodon, Salvia farinacea, Plumbago capensis, Ceratostigma plumbaginoides, Commelina communis and Salvia patens. The spectroscopic methods were applied both in vivo on the flower petals and in vitro on extracts obtained through a procedure based on SPE (solid-phase extraction) optimized for minimal quantities of vegetable raw material. Different patterns obtained for the Raman spectra have been correlated, also on the basis of density functional theory (DFT) calculations, with different schemes of substitution of the benzopyrilium nucleus of the anthocyanins and with various possible forms of copigmentation responsible for the stabilization of the blue color. The results obtained were verified by comparison with the analysis of the extracts by HPLC-ESI-MS (liquid chromatography-electrospray ionization-mass spectrometry).

The rapid determination of nitrogen, phosphorus, potassium and other major nutrient elements is an important technical guarantee in the quality control of chemical fertilizers. In this study, a small visible spectrometer and a small near-infrared spectrometer were used to collect spectrum information of 33 different common chemical fertilizers including compound fertilizers, blended fertilizers and controlled-release fertilizers. The 550~950 nm and 1050~1640 nm spectra with stable signals were intercepted as the analysis spectrum, and the competitive adaptive reweighted sampling algorithm (CARS) was used to select 161, 229, and 161 spectral characteristic wavelengths for the three nutrient contents of N, P2O5, and K2O respectively. The partial least squares (PLS) and extreme learning machine (ELM) models of N, P2O5, and K2O were established based on the 550~950 nm waveband, 1050~1640 nm waveband, full spectrum, and characteristic wavelength, respectively. The coefficient of determination ( R 2 ), root mean square error (RMSE), and residual predictive deviation (RPD) were used to evaluate the effect of the model. With the optimal prediction models, the values of R p 2 for N, P2O5, and K2O were 0.989, 0.963, 0.981, and for RPD were 9.71, 5.09, 7.29, respectively. The research results show that Vis/NIR spectroscopy can predict the content of nitrogen, phosphorus, and potassium nutrients in fertilizers, and the near-infrared band from 1050 nm to 1640 nm has a better prediction effect. The characteristic wavelength selection reduces the spectral variables by 9/10, and the performance of the model based on the characteristic wavelength is close to that of the full-spectrum model. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the optical response of an expired External Beam Therapy (EBT3) film, which expired in 2018, using X-rays and electron beam doses. The film’s optical responses were evaluated for its usability in measuring different radiation sources, energy, and absorbed doses ranging up to 5 Gy. Pieces of the expired EBT3 film were irradiated with 90 kVp, 6 MV X-ray photons, and 6 MeV electron beam. The analysis was performed using the Jaz visible spectrometer and EPSON Perfection V370 Photo scanner to obtain the absorbance and the net relative optical density (ROD) of the film samples respectively. The results showed that spectroscopic measurements of the exposed expired EBT3 films under these radiation sources were able to produce primary secondary peaks at λ = 633.52 nm and λ = 582.3 nm respectively. The best wavelength subsets that presented the best MLR regression fitting for all experiments were 541.48 nm, 561.11 nm, and 600.28 nm. While, for the 6 MV photon and the 6 MeV electron beam they were 600.28 nm, 650.79 nm and 654.10 nm. In case of the irradiation with the 6 MV photon and the 6 MeV electron beam, expired EBT3 film showed no significant differences, which made it suitable for dosimetry in various sources of radiation. The individual calibration of radiation dose produces very high measurement accuracy with coefficient of determination, R2 above 0.99 and root mean square of error, RMSE of 0.038 Gy, 0.113 Gy, and 0.115 Gy for films irradiated with 90 kVp X-rays, 6 MV photon beam, and 6 MeV electron beam respectively. Hence, from the results, the expired EBT3 film used in this study showed promising usability of expired EBT3 films beyond their prescribed expiry dates.

At the moment, the most accurate and reliable information about intermolecular interactions in low-molecular compounds and their polymer analogues can be obtained by means of combined UV, visible, and IR spectroscopy. However, this combination is not always used when interpreting the results of intermolecular interactions in carboxylic acids. Therefore, the aim of our study was to investigate the intermolecular interactions in carboxylic acids and their hydration properties using the UV, visible, and IR spectroscopy. The article presents the results of the investigation of intermolecular interactions and hydration in carboxylic acids by means of UV, visible, and IR spectroscopy, and the microscopic study of the swelling/contraction curves of the beads of the sorbents with slightly acidic –СООН groups in exchange reactions of R–COOH + NaOH ↔ R–COO–Na+ + H2O. The study revealed a H-bond in the water dimers formed due to the Coulomb, exchange, charge transfer, polarisation, and dispersion components of the total energy of the hydrogen bonds. In our study we also tested the formulas for the calculation of the energy of the H-bond, enthalpy, the force constants of the Н-bond, and the elongation of the covalent bond. The article suggests a formula for calculating the distance RCH2…O, i.e. the length of the H-bond between the donor and the acceptor of the proton, based on the information about stretching vibrations in the IR spectra of carboxylic acids. We also specified the characteristic frequencies of the stretching and deformation vibrations of certain H-bonds and functional groups in fatty acids. The article demonstrates the possibility of the formation of five- and six-membered cycles, resulting from the formation of Н-bonds between СН2 groups of the chain and –СООН end groups of carboxylic acids. The characteristic electron and vibrational frequencies in the UV and IR spectra were used to determine the intermolecular interactions in ion exchangers CB-2 and CB-4. The microscopic and microphotographic study of the swelling of certain beads of carboxylic cationites helped to register the presence of the outer shell R–COO–…Me+ and the inner shell R-COOH during the exchange reactions: R–COOH + Me+ + OH– ↔ R–COO–…Me+ + H2O.

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In critically ill patients, direct knowledge of intracellular pO2 would allow for identification of cellular hypoxia, which when prolonged leads to organ failure. We have developed a visible–near-infrared optical system that noninvasively measures myoglobin saturation, which is directly related to intracellular pO2, from the surface of the skin. We used an animal model of graded hypoxia from low levels of inspired oxygen (n = 5) and verified that low intracellular pO2 is correlated with high steady-state serum lactate values. In addition, the pO2 gradient between arterial blood and inside muscle cells was 83 mm Hg at 21% O2, but fell to 24 mm Hg at 8% O2. Continuous myoglobin saturation measurement in skeletal muscle displayed the same trends as cerebral oxygenation with no lag in changes over time, demonstrating its relevance as a measure of systemic oxygenation. [ABSTRACT FROM AUTHOR]

A small portion of an optical fibre clad was removed and coated with methylamine hydroiodide by a slurry deposition process to develop an evanescent wave optical fibre ammonia sensor. The experiment was performed for a few volatile organic compounds in order to understand the selectivity and sensitivity. Prior to the gas sensing measurement, the methylamine hydroiodide sample was characterised using X‐ray diffraction (XRD), scanning electron microscope with energy dispersive X‐ray spectroscopy, Fourier transform infrared, Raman, diffuse reflectance and UV–Vis spectroscopy. In order to understand the sensor response, the samples were independently exposed to acetone, ammonia, ethanol and methanol gases and then analysed using the XRD technique. This analysis reveals that the structural variation is observed because of the ammonia exposure as compared to other gases. It has initiated to fabricate a clad‐modified optical fibre ammonia sensor that exhibits ∼28% of the sensitivity. These experimental results are discussed in detail. [ABSTRACT FROM AUTHOR]

1. Sex-specific variations in early embryonic development rates may pre-empt later variations in embryonic development through to pipping and hatching. Given that erythropoiesis (blood production) can be equated with early embryonic growth rate, it was hypothesised that blood pigment haemoglobin can act as a specific spectral fingerprint for changes in growth rate. Moreover, by measuring longitudinal, rather than lateral, spectral transmission through the egg, a more consistent spectrum with a higher signal-to-noise ratio could be captured. 2. Longitudinal visible transmission (T575/T598 ratio), which is sensitive to haemoglobin, was used to monitor sex-specific early embryonic development rate in white layer chicken eggs from d 0 to 8 of incubation. The sex of these eggs was subsequently confirmed two days after hatching. 3. Embryonic development was detectable from d 3 (72 h) of incubation, 36 h earlier than previously reported lateral spectral measurements, supporting the greater sensitivity of longitudinal measurements. 4. At d 3, the mean T575/T598 ratio for male embryos was significantly lower (P < 0.001) (i.e. higher absorbance of haemoglobin) than for female embryos, which was thought to be due to sex-differences in early embryogenesis. On the other hand, female embryos had a significantly lower (P < 0.05) mean T575/T598 ratio than male embryos at d 7 of incubation, presumably due to the combined effects of oestrogen synthesis receptors and enzymes on erythropoiesis in female embryos at this time. 5. In conclusion, the proposed methodology has the sensitivity to differentiate sex-specific embryonic development rates during early incubation and the potentiality to advance precision incubation management and poultry research. [ABSTRACT FROM AUTHOR]

Here a spectrophotometric technique in the visible region combined with an environmental friendly ultra-pure water based liquid-liquid extraction procedure has been described for the determination of total hydroxytyrosol in virgin olive oils regardless of whether it is free or combined. Determination of total hydroxytyrosol was carried out where the absorption peak of the colored compounds formed with autopolymerization of quinones that occured following the oxidation of hydroxytyrosol and its secoiridoid derivatives in a basic medium was measured as an analytical signal. The method was linear in a concentration range of 0.2-15.0 mg L-1 with a correlation coefficient of 0.9990. Detection and quantification limits were 0.05 and 0.18 mg L-1, respectively. Intra-day and inter-day precision studies indicated that the proposed method was repeatable. In addition, the liquid-liquid extraction procedure was quite efficient with recovery values between 108 and 117%. Finally, the proposed method was successfully applied to the analysis of total hydroxytyrosol in a virgin olive oil and the results were compared with those obtained by a method existing in the literature for the determination of total hydroxytyrosol based on acid hydrolysis of secoiridoid aglycons followed by liquid chromatography-tandem mass spectrometry. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging is a well-known technique for quality control of food and agricultural products. This technique is often applied to the measurement of large and heterogeneous samples, where chemical imaging is extremely useful. In addition, when the amount of sample is limited by different factors (price, other analyses, sample production, etc.) hyperspectral imaging is an alternative to traditional spectroscopes for acquiring its spectral information. In this study, a new and specific methodology to acquire hyperspectral information from small amounts of granular samples has been developed. For this purpose, two different hyperspectral devices (400–1100 nm, 900–1700 nm) have been used. A statistical procedure has been followed to test the proposed method. In grape seed protein concentrates, NIR radiation (900–1700 nm) penetrates deeper into the sample than VisNIR radiation (400–1100 nm). Therefore, the minimum amount of sample needed to measure in the NIR range is larger than that needed to measure in the VisNIR range. Finally, different calibration models have been developed for the control of protein content in the tested samples. Standard errors of prediction obtained in external validation are similar to those reported in the literature when sample amount is not an issue (9–10 %). [Display omitted] • Hyperspectral imaging allows the acquisition of the spectrum of small samples. • A new methodology has been developed to acquire spectra of small granular samples. • NIR penetrates deeper into grape seed protein concentrates than Visible radiation. • The proposed methodology allows for adequate monitoring of proteins in the samples. [ABSTRACT FROM AUTHOR]

The rapid determination of nitrogen, phosphorus, potassium and other major nutrient elements is an important technical guarantee in the quality control of chemical fertilizers. In this study, a small visible spectrometer and a small near-infrared spectrometer were used to collect spectrum information of 33 different common chemical fertilizers including compound fertilizers, blended fertilizers and controlled-release fertilizers. The 550~950 nm and 1050~1640 nm spectra with stable signals were intercepted as the analysis spectrum, and the competitive adaptive reweighted sampling algorithm (CARS) was used to select 161, 229, and 161 spectral characteristic wavelengths for the three nutrient contents of N, P2O5, and K2O respectively. The partial least squares (PLS) and extreme learning machine (ELM) models of N, P2O5, and K2O were established based on the 550~950 nm waveband, 1050~1640 nm waveband, full spectrum, and characteristic wavelength, respectively. The coefficient of determination (R2), root mean square error (RMSE), and residual predictive deviation (RPD) were used to evaluate the effect of the model. With the optimal prediction models, the values of Rp2 for N, P2O5, and K2O were 0.989, 0.963, 0.981, and for RPD were 9.71, 5.09, 7.29, respectively. The research results show that Vis/NIR spectroscopy can predict the content of nitrogen, phosphorus, and potassium nutrients in fertilizers, and the near-infrared band from 1050 nm to 1640 nm has a better prediction effect. The characteristic wavelength selection reduces the spectral variables by 9/10, and the performance of the model based on the characteristic wavelength is close to that of the full-spectrum model.

By studying the evolution of the color index (CI) during twilight at high latitudes, polar stratospheric clouds (PSCs) can be detected and characterized. In this work, this method has been applied to the measurements obtained by a visible ground-based spectrometer and PSCs have been studied over the Belgrano II Antarctic station for years 2018 and 2019. The methodology applied has been validated by full spherical radiative transfer simulations, which confirm that PSCs can be detected and their altitude estimated with this instrumentation. Moreover, our investigation shows that this method is useful even in presence of optically thin tropospheric clouds or aerosols. PSCs observed in this work have been classified by altitude. Our results are in good agreement with the stratospheric temperature evolution obtained by the global meteorological model ECMWF (European Centre for Medium Range Weather Forecasts) and with satellite PSCs observations from CALIPSO (Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations). To investigate the presence and long-term evolution of PSCs, the methodology used in this work could also be applied to foreseen and/or historical observations obtained with ground-based spectrometers such e. g. those dedicated to Differential Optical Absorption Spectroscopy (DOAS) for trace gas observation in Arctic and Antarctic sites.

This is a short communication of an inexpensive and safe experiment used in Analytical Chemistry. The experiment uses the idea of Beer’s law from a Freshman Chemistry Laboratory course for one material, where the absorption of light changes with the amount of material. However, in this experiment, it is expanded for two materials. Plus, since both materials are dyes and usually readily available in a College or University, it makes it both affordable and easy to use. [ABSTRACT FROM AUTHOR]

Lipstick traces may be encountered in forensic investigations as traces left on clothing, drinkware, tissue papers or other surfaces. However, their probative value is limited by the discriminatory power and destructiveness of existing analysis schemes. This work employed analytical spectroscopy with chemometrics to provide objective and non-destructive characterisation of lipsticks for forensic purposes. 22 red-shaded and 18 nude-shaded lipsticks were analysed using visible absorbance and diffuse reflectance spectroscopy, as well as attenuated total reflectance Fourier transform infrared spectroscopy. Principal component analysis readily distinguished most samples based on their spectral profiles, with subsequent models yielding discrimination accuracies exceeding 94% for each spectroscopic mode. This could provide a greater level of confidence when conducting 'questioned versus known' comparisons of similar lipsticks. Further testing using external validation sets produced identification accuracies of 73-100 %, which may allow investigative leads to be more readily obtained from recovered lipstick traces. [ABSTRACT FROM AUTHOR]

Colorimetric parameters have potential to differentiate tree species through their wood type. Therefore, this can be used to aid the inspection of illegal trade. Thus, considering the need to identify species with precision and speed, this study aimed to explore the potential of these parameters in order to characterize wood of some species of native Myrtaceae from the Araucaria Forest: Campomanesia xanthocarpa Berg., Eugenia pyriformis Cambess., Myrcia retorta Cambess., and Plinia Peruviana (Poir.) Govaert. Twelve trees were collected randomly - three per species - for the removal of a disc at diameter at breast height (DBH). We took samples from three regions of the disc (next to the bark, intermediate and next to the pith) and analyzed them in three anatomical sections (transversal, radial and tangential) by the system CIE L*a*b* using a bench colorimeter. We analyzed the data based on the following criteria: test of means in order to differentiate species, quantitative factor analysis (considering the region of the disc and the anatomical section as factors), and principal components analysis (PCA). Then, we used the original spectrum and the values of parameters L*, a* and b* in order to verify the distribution of the species. The analysis determined that the species present different values for the colorimetric parameters. In addition, the factors region of the disc and anatomical section have specific influence for each species. Finally, the PCA indicated that only E. pyriformis differs from the others. [ABSTRACT FROM AUTHOR]

Abstract A commercial near-infrared (NIR) instrument for bulk samples and a modified Single Kernel Near-Infrared (SKNIR) instrument equipped with a visible or NIR spectrometer were studied as a way to measure damage levels caused by Sunn pest (SP) in wheat. Sunn pest causes damage by feeding on wheat berries and injecting a salivary enzyme damaging the gluten. For measurement of SP damage in bulk wheat, NIR calibration models developed for mixtures containing 0–10% and 0–100% sound and SP damaged wheat resulted in R2 of 0.25 and 0.89 and SECVs of 2.75 and 10.9, respectively. The 0–100% model was considered a qualitative measure of damage, but predictions were poor over 0–10% which is a critical range for commercial applications. Discrimination between single kernels of Sound and SP-damaged was typically good, with classification accuracy averaging ∼75% for both visible and NIR although some were poor, which greatly affected the average. Average classification accuracy was ∼85% for spectral data that contained kernels from all samples. While the potential for using visible or NIR spectroscopy was shown, results highlighted the need to develop a more robust SP classification model to further evaluate the single kernel model. Highlights • Detection of Sunn pest damage in single wheat kernel by Visible/NIR spectra is promising. • Measurement of Sunn pest-damaged wheat by bulk NIR spectra has limited commercial value. • Spectral signatures of Sound and Sunn pest-damaged wheat are different. [ABSTRACT FROM AUTHOR]

[Display omitted] • DASA exhibits ternary photoswitching in solution but binary in polymer blends. • Phase locked UV–Vis detection utilized to track photochemical intermediates. • Polymeric hosts slow photoisomerization without affecting stability. • Stabilizing ternary states of DASA in polymers requires improved quantum efficiency. Molecular photoswitches provide a means for imparting synthetic structures with intrinsically logical and highly tunable photoresponsive properties. One variety of organic photoswitches known as Donor-Acceptor Stenhouse Adducts, or DASAs, are promising candidates for next generation light responsive materials because of their unique ability to stabilize three photochemically distinct isomeric states in solution, while their counterparts are strictly limited to binary state behavior. In this work, we show how polymethacrylate host matrices shift the energetic landscape of DASA relative to solution, prohibiting accumulation of an intermediate third isomeric state by decelerating critical steps in the photoswitching mechanism. Specifically, we employ a dual-wavelength, phase locked detection scheme to probe thermal isomerizations in the switching process that occur at fast (∼ms) time scales that are inaccessible by standard UV–Vis spectroscopic techniques. The results of this study provide valuable insight into the mechanism of multistate DASA reactivity and establish the foundation necessary to guide future efforts in offsetting kinetic matrix effects to enable dynamic, three state photoswitching in polymeric hosts. [ABSTRACT FROM AUTHOR]

Olive oil samples from three different Greek regions (Crete, Peloponnese and Lesvos) were examined by optical spectroscopy in a wide spectral region from ultraviolet to near infrared using absorption, fluorescence and Raman spectroscopies. With the aid of machine learning methods, such as multivariate partial least squares discriminant analysis, a clear classification of samples originating from the different Greek geographical regions was revealed. Moreover, samples produced in different subareas of Crete and Peloponnese were also well discriminated. Furthermore, mixtures of olive oils from different geographical origins were studied employing partial least squares as a tool to establish a model between the actual and predicted compositions of the mixtures. The results demonstrated that optical spectroscopy combined with multivariate statistical analysis can be used as an emerging innovative alternative to the classical analytical methods for the identification of the origin and authenticity of olive oils.

Archaeological indicators of cognitive complexity become increasingly prevalent during the African Middle Stone Age, with the habitual exploitation of red ochre widely viewed as a key feature of the emergence of modern human behaviour. Given that some of the uses of ochre remain ambiguous, we present the preliminary results of an ongoing study in which we explore the efficacy of red ochre as a photoprotective device or sunscreen. The capacity of ochre to inhibit the susceptibility of humans to the detrimental effects of ultraviolet radiation was confirmed through the in vitro calculation of the sun protection factor values of samples derived from the Kunene Region in Namibia and the Bokkeveld Group deposits, Western Cape Province, South Africa. Visible spectroscopy was employed to determine colourimetric parameters of samples and assess the correlation between ochre colour and sun protection factor. The possible role of ochre as a sunscreen agent for hominin populations, including modern humans, during the Middle Stone Age in Africa is explored. We conclude that the habitual use of red ochre as a photoprotective agent likely played a role in the ability of prehistoric humans to adapt to novel environmental circumstances.

Four time-lapse cameras, Bushnell Nature View HD Camera (Bushnell, Overland Park, KS, USA) were installed in a soybean field to track the response of soybean plants to changing weather conditions. The purpose was to confirm if visible spectroscopy can provide useful data for tracking the condition of crops and, if so, whether game and trail time-lapse cameras can serve as reliable crop sensing and monitoring devices. Using the installed cameras, images were taken at 30-min intervals between July 22 and August 1, 2015. Using the RGBExcel software application developed in-house, image data from the R (red), G (green), and B (blue) bands were exported to Microsoft Excel for further processing and analysis. Daytime adjusted green red index data for the plant, based on the R and G data, were plotted against time of image acquisition and also regressed with selected weather parameters. The former showed a rise-and-fall trend with daily peaks around 13:00, while the latter showed a decreasing order of correlation with weather variables as follows: log of solar radiation > log of soil surface temperature > log of air temperature > log of soil temperature at 50-mm depth > log of relative humidity. Despite some low correlations, the potential for using game and trail cameras with time-lapse capability to track changes in crop vegetation response under varying conditions is established. The resulting data can be used to develop models that can aid precision agriculture applications. This can be further explored in future studies. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We characterized the radical species generated from the corona discharge of 3- and 4-chloro-o-xylenes. • We identified the formation of the 3-, 4-, 5-, and 6-chloro-2-methylbenzyl radicals from analysis of the observed spectra. • We determined the spectroscopic data of the benzyl-type radicals produced in this work. • We discussed the distribution of the electronic transition energies of 4 isomeric radical species. Abstract Four isomeric chloro-substituted 2-methylbenzyl radicals were generated from the corona discharge of 3- and 4-chloro- o -xylenes seeded in a large amount of He carrier gas using a technique of corona excited supersonic expansion coupled with a pinhole-type glass nozzle. The observed visible vibronic emission spectra were analyzed to identify the radical species produced in the discharge, from which the production of the 3-, 4-, 5-, and 6-chloro-2- methylbenzyl radicals was confirmed. In addition, we determined the D 1 → D 0 electronic transition energies and vibrational mode frequencies in the D 0 state of the isomeric chloro-substituted 2-methylbenzyl radicals. [ABSTRACT FROM AUTHOR]

Mounting‐up economic losses to annual crops yield due to micronutrient deficiency, fertiliser inefficiency and increasing microbial invasions (e.g. Xanthomonas cempestri attack on tomatoes) are needed to be solved via nano‐biotechnology. So keeping this in view, the authors' current study presents the new horizon in the field of nano‐fertiliser with highly nutritive and preservative effect of green fabricated zinc oxide‐nanostructures (ZnO‐NSs) during Lycopersicum esculentum (tomato) growth dynamics. ZnO‐NS prepared via green chemistry possesses highly homogenous crystalline structures well‐characterised through ultraviolet and visible spectroscopy, Fourier transform infrared spectroscopy, X‐ray diffraction and scanning electron microscope. The ZnO‐NS average size was found as small as 18 nm having a crystallite size of 5 nm. L. esculentum were grown in different concentrations of ZnO‐NS to examine the different morphological parameters includes time of seed germination, germination percentage, the number of plant leaves, the height of the plant, average number of branches, days count for flowering and fruiting time period along with fruit quantity. Promising results clearly predict that bio‐fabricated ZnO‐NS at optimum concentration resulted as growth booster and dramatically triggered the plant yield. [ABSTRACT FROM AUTHOR]

A facile and green process to synthesise cuttlebone supported palladium nanoparticles (Pd NPs/cuttlebone) is reported using Conium maculatum leaf extract and in the absence of chemical solvents and hazardous materials. The antioxidant content of the C. maculatum leaf extract played a significant role in converting Pd2+ ions to Pd NPs. Various techniques were used for the characterisation of the Pd NPs/cuttlebone such as field‐emission scanning electron microscopy, X‐ray diffraction, energy dispersive X‐ray spectroscopy, Fourier transform infrared and ultraviolet–visible spectroscopy. This Pd NPs/cuttlebone showed excellent catalytic activity in the reduction of 2,4‐dinitrophenylhydrazine to 2,4‐diaminophenylhydrazine by sodium borohydride as the source of hydrogen at ambient condition. The catalyst could be separated and recycled up to five cycles with no loss of its activity. [ABSTRACT FROM AUTHOR]