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To measure the distinct interaction of the Earth's materials with solar electromagnetic radiation, field spectroradiometers are commonly utilized. These are used to validate spectroradiometers deployed on various platforms through comparison exercises. Following metrology standards, the inclusion of uncertainties is required. Thus, field spectroradiometers need to be calibrated regularly against traceable radiance sources. In this article, we present a laboratory radiometric calibration protocol for the calibration of a heliosphere integrating sphere to make it traceable to the International System of Units as well as to establish an uncertainty budget. We adopted a transfer radiometer approach including four spectroradiometers that were calibrated at the Deutsches Zentrum für Luft und Raumfahrt Radiometric Standard facility before transferring that calibration to the heliosphere. After considering various sources of uncertainty by employing an uncertainty tree diagram approach, we arrive at an overall propagated uncertainty of approximately 1.5%. In future publications, we will present how to extend the traceability to other attenuations provided by the heliosphere. Its application to the calibration of a field spectroradiometer will be the focus of a future publication.

A new method for the synthesis and deposition of tungsten oxide nanopowders directly on the surface of a carbon-fiber-reinforced polymer composite (CFRP) is presented. The CFRP was chosen because this material has very good thermal and mechanical properties and chemical resistance. Also, CFRPs have low melting points and are transparent under ionized radiation. The synthesis is based on the direct interaction between high-power-density microwaves and metallic wires to generate a high-temperature plasma in an oxygen-containing atmosphere, which afterward condenses as metallic oxide nanoparticles on the CFRP. During microwave discharge, the value of the electronic temperature of the plasma, estimated from Boltzmann plots, reached up to 4 eV, and tungsten oxide crystals with a size between 5 nm and 100 nm were obtained. Transmission electron microscopy (TEM) analysis of the tungsten oxide nanoparticles showed they were single crystals without any extended defects. Scanning electron microscopy (SEM) analysis showed that the surface of the CFRP sample does not degrade during microwave plasma deposition. The X-ray attenuation of CFRP samples covered with tungsten oxide nanopowder layers of 2 µm and 21 µm thickness was measured. The X-ray attenuation analysis indicated that the thin film with 2 µm thickness attenuated 10% of the photon flux with 20 to 29 KeV of energy, while the sample with 21 µm thickness attenuated 60% of the photon flux.

The chemical group comprising polycyclic aromatic hydrocarbons (PAHs) has received prolonged evaluation and scrutiny in the past several decades. PAHs are ubiquitous carcinogenic pollutants and pose a significant threat to human health through their environmental prevalence and distribution. Regardless of their origin, natural or anthropogenic, PAHs generally stem from the incomplete combustion of organic materials. Dietary intake, one of the main routes of human exposure to PAHs, is modulated by pre-existing food contamination (air, water, soil) and their formation and accumulation during food processing. To this end, processing techniques and cooking options entailing thermal treatment carry additional weight in determining the PAH levels in the final product. With the background provided, this study aims to provide an improved understanding of PAH occurrence in meat, edible oils, and cereal products. The factors influencing PAH formation, including operational conditions and parameters, product composition, and storage settings, are described. The discussion also addresses reduction directions with respect to influencing factors informing the choice of the employed technique, fuel type, time–temperature settings, and ingredient variations. Considering the disparities caused by wide variations in PAH contamination, challenges associated with PAH control requirements are also outlined in the context of relevant preventive approaches during food processing.

The aim of this work was to develop an analytical method for determining acrylamide in potato-based products by gas chromatography and tandem mass spectrometry analysis (GC-MS/MS) using solid-phase extraction (SPE) clean-up. Different conditions for extraction and clean-up of AA extracts were studied on a potato crisps reference material (RM) with the value of 625 ± 45 μg/kg: the solvent volume used for AA elution, the extraction water temperature, the volume of hexane used, and also the addition of Carrez solutions. The SPE cartridge sorbents contain silica-based C-18 groups (anion and cation exchangers) and polymers (polystyrene-divinylbenzene). After SPE clean-up, extracts were derivatized with bromine compounds. A good efficiency for AA extraction and a cleaned-up extract from this matrix were obtained when the SPE procedure was carried out with water at room temperature, simultaneous with hexane, without Carrez solutions, by using two types of SPE cartridges (Isolute Multimode; Isolute ENV+), and 5 mL of elution solvent. The SPE clean-up procedure functionality was demonstrated by the results obtained in the Food Analysis Performance Assessment Scheme proficiency test (z-score: −0.8) on French fries (precooked) matrix and also by comparative analysis with a laboratory procedure, validated and accredited on cereal-based food matrices, in which liquid–liquid extraction and clean-up through a florisil column were realized (RSD(R) = 2.23–5.10%).

This paper reports the results obtained for a distributed-feedback quantum cascade laser (DFB-QCL) exposed to different fluences of proton particles: 1014, 1015 and 1016 p/cm2. Dedicated laboratory setups were developed to assess the irradiation-induced changes in this device. Multiple parameters defining the QCL performances were investigated prior to and following each irradiation step: (i) voltage-driving current; (ii) emitted optical power-driving current; (iii) central emitting wavelength-driving current; (iv) emitted spectrum-driving current; (v) transversal mode structure-driving current, maintaining the system operating temperature at 20 °C. The QCL system presented, before irradiation, two emission peaks: a central emission peak and a side peak. After proton irradiation, the QCL presented a spectral shift, and the ratio between the two peaks also changed. Even though, after irradiation, the tunning spectral range was reduced, at the end of the tests, the system was still functional.

The aim of this study was to develop and evaluate some validation parameters of a GC-MS sensitive method for the separation, identification, and simultaneous quantification of 18 cis/trans isomers of oleic (FAME C18:1), linoleic (FAME C18:2), and linolenic acid (FAME C18:3) methyl esters. Linearity, sensitivity, and recovery of the developed method were evaluated on calibration solutions. Correlation coefficients (R) were higher than 0.99 in the linear domain for each isomer, the sensitivity of the method was characterized by LOD = 0.03 - 0.05 g/100 g of fat, and LOQ = 0.09 - 0.17 g/100 g of fat, and the recovery ranged between 101.32 - 102.59%. Samples of potato chips were used to demonstrate the applicability of the method and the trans fatty acids (TFA) levels in analyzed sample were below 0.60 g/100 g fat, complying with international recommendations of less than 2 g/100 g of total fat. The proposed GC-MS method allows simultaneous determination of 18 cis/trans isomers (13 trans and 5 cis) of FAME C18 from potato chips.

The aim of this study was to investigate the influence of some pre-treatment applications toward acrylamide mitigation in potatoes fried in domestic conditions modeled after those found in Romania, by using a pan and a fryer. Before being fried in a pan, potato strips were treated in one of the following ways: soaked in cold water for 15, 60, and 120 min (a); soaked in hot water at different combinations of temperatures and durations (60, 70, 80 °C for 5, 10, 15 min) (b); soaked in a NaCl solution (c), and; in a citric acid solution (d) both solutions of 0.05% and 1% concentration for 30 min. For potatoes fried in a fryer, the (a) pre-treatment and soaking in water at 80 °C for 5, 10, and 15 min were applied. Untreated samples were used as a control. French fries were analyzed in terms of moisture and acrylamide content, color, and texture parameters. The pre-treatments applied reduced the acrylamide content in French fries by 4–97% when fried in the pan and by 25–47% when fried in the fryer. Acrylamide content of French fries was negatively correlated with L* parameter and moisture content and positively correlated with a* parameter. The pre-treatments applied can be used successfully by consumers to reduce acrylamide content.

In this paper, we propose a highly selective and efficient gas detection system based on a narrow-band IR metasurface emitter integrated with a resistive heater. In order to develop the sensor for the detection of specific gases, both the microheater and metasurface structures have been optimized in terms of geometry and materials. Devices with different metamaterial structures and geometries for the heater have been tested. Our prototype showed that the modification of the spectral response of metasurface-based structures is easily achieved by adapting the geometrical parameters of the plasmonic micro-/nanostructures in the metasurface. The advantage of this system is the on-chip integration of a thermal source with broad IR radiation with the metasurface structure, obtaining a compact selective radiation source. From the experimental data, narrow emission peaks (FWHM as low as 0.15 μm), corresponding to the CO2, CH4, and CO absorption bands, with a radiant power of a few mW were obtained. It has been shown that, by changing the bias voltage, a shift of a few tens of nm around the central emission wavelength can be obtained, allowing fine optimization for gas detection applications.

A new method for the synthesis and deposition of tungsten oxide nanopowders directly on the surface of a carbon-fiber-reinforced polymer composite (CFRP) is presented. The CFRP was chosen because this material has very good thermal and mechanical properties and chemical resistance. Also, CFRPs have low melting points and are transparent under ionized radiation. The synthesis is based on the direct interaction between high-power-density microwaves and metallic wires to generate a high-temperature plasma in an oxygen-containing atmosphere, which afterward condenses as metallic oxide nanoparticles on the CFRP. During microwave discharge, the value of the electronic temperature of the plasma, estimated from Boltzmann plots, reached up to 4 eV, and tungsten oxide crystals with a size between 5 nm and 100 nm were obtained. Transmission electron microscopy (TEM) analysis of the tungsten oxide nanoparticles showed they were single crystals without any extended defects. Scanning electron microscopy (SEM) analysis showed that the surface of the CFRP sample does not degrade during microwave plasma deposition. The X-ray attenuation of CFRP samples covered with tungsten oxide nanopowder layers of 2 µm and 21 µm thickness was measured. The X-ray attenuation analysis indicated that the thin film with 2 µm thickness attenuated 10% of the photon flux with 20 to 29 KeV of energy, while the sample with 21 µm thickness attenuated 60% of the photon flux. [ABSTRACT FROM AUTHOR]

Nowadays, biscuits are one of the most consumed bakery products and during its processing acrylamide, a chemical contaminant can be formed. The aim of this study was to investigate the influence of the sweetener, fat and the baking conditions on the acrylamide content and color parameters of biscuits. In the formulation recipe of biscuits sweeteners sugar, fructose were used, as well as fat (butter, palm oil). The baking conditions were: 200, and 210 0C for 20, and 30 minutes. The acrylamide content was determined by tandem mass spectrometry (GC-MS/MS). The limit of detection and limit of quantitation of the method were 1.23 μg/kg and 3.7 μg/kg, respectively. Correlations between the acrylamide content and color parameters L*, a*, b* were established. Color parameters were determined with a Konica Minolta colorimeter. The relationship between the acrylamide content and color parameters L*, a*, b* were established by using Pearson correlation. Results showed that regardless of the baking conditions, for the biscuits formulated with sugar and butter, the acrylamide content was significantly smaller (< LOQ - 12.28 μg/kg) than for the ones made with sugar and palm oil (

The chemical group comprising polycyclic aromatic hydrocarbons (PAHs) has received prolonged evaluation and scrutiny in the past several decades. PAHs are ubiquitous carcinogenic pollutants and pose a significant threat to human health through their environmental prevalence and distribution. Regardless of their origin, natural or anthropogenic, PAHs generally stem from the incomplete combustion of organic materials. Dietary intake, one of the main routes of human exposure to PAHs, is modulated by pre-existing food contamination (air, water, soil) and their formation and accumulation during food processing. To this end, processing techniques and cooking options entailing thermal treatment carry additional weight in determining the PAH levels in the final product. With the background provided, this study aims to provide an improved understanding of PAH occurrence in meat, edible oils, and cereal products. The factors influencing PAH formation, including operational conditions and parameters, product composition, and storage settings, are described. The discussion also addresses reduction directions with respect to influencing factors informing the choice of the employed technique, fuel type, time–temperature settings, and ingredient variations. Considering the disparities caused by wide variations in PAH contamination, challenges associated with PAH control requirements are also outlined in the context of relevant preventive approaches during food processing. [ABSTRACT FROM AUTHOR]

The paper presents a set of tests carried out in order to evaluate the design characteristics and the operating performance of a set of six X-ray extrinsic optical fiber sensors. The extrinsic sensor we developed is intended to be used as a low energy X-ray detector for monitoring radiation levels in radiotherapy, industrial applications and for personnel dosimetry. The reproducibility of the manufacturing process and the characteristics of the sensors were assessed. The sensors dynamic range, linearity, sensitivity, and reproducibility are evaluated through radioluminescence measurements, X-ray fluorescence and X-ray imaging investigations. Their response to the operating conditions of the excitation source was estimated. The effect of the sensors design and implementation, on the collecting efficiency of the radioluminescence signal was measured. The study indicated that the sensors are efficient only in the first 5 mm of the tip, and that a reflective coating can improve their response. Additional tests were done to investigate the concentricity of the sensors tip against the core of the optical fiber guiding the optical signal. The influence of the active material concentration on the sensor response to X-ray was studied. The tests were carried out by measuring the radioluminescence signal with an optical fiber spectrometer and with a Multi-Pixel Photon Counter.

Growing interest in the proximal sensing of sun-induced chlorophyll fluorescence (SIF) has been boosted by space-based retrievals and up-coming missions such as the FLuorescence EXplorer (FLEX). The European COST Action ES1309 “Innovative optical tools for proximal sensing of ecophysiological processes„ (OPTIMISE, ES1309; https://optimise.dcs.aber.ac.uk/) has produced three manuscripts addressing the main current challenges in this field. This article provides a framework to model the impact of different instrument noise and bias on the retrieval of SIF; and to assess uncertainty requirements for the calibration and characterization of state-of-the-art SIF-oriented spectroradiometers. We developed a sensor simulator capable of reproducing biases and noises usually found in field spectroradiometers. First the sensor simulator was calibrated and characterized using synthetic datasets of known uncertainties defined from laboratory measurements and literature. Secondly, we used the sensor simulator and the characterized sensor models to simulate the acquisition of atmospheric and vegetation radiances from a synthetic dataset. Each of the sensor models predicted biases with propagated uncertainties that modified the simulated measurements as a function of different factors. Finally, the impact of each sensor model on SIF retrieval was analyzed. Results show that SIF retrieval can be significantly affected in situations where reflectance factors are barely modified. SIF errors were found to correlate with drivers of instrumental-induced biases which are as also drivers of plant physiology. This jeopardizes not only the retrieval of SIF, but also the understanding of its relationship with vegetation function, the study of diel and seasonal cycles and the validation of remote sensing SIF products. Further work is needed to determine the optimal requirements in terms of sensor design, characterization and signal correction for SIF retrieval by proximal sensing. In addition, evaluation/validation methods to characterize and correct instrumental responses should be developed and used to test sensors performance in operational conditions.

Miniaturized thermal infrared (TIR) cameras that measure surface temperature are increasingly available for use with unmanned aerial vehicles (UAVs). However, deriving accurate temperature data from these cameras is non-trivialsince they are highly sensitive to changes in their internal temperature and low-cost models are often not radiometrically calibrated. We present the results of laboratory and field experiments that tested the extent of the temperature-dependency of a non-radiometric FLIR Vue Pro 640. We found that a simple empirical line calibration using at least three ground calibration points was sufficient to convert camera digital numbers to temperature values for images captured during UAV flight. Although the camera performed well under stable laboratory conditions (accuracy ±0.5 °C), the accuracy declined to ±5 °C under the changing ambient conditions experienced during UAV flight. The poor performance resulted from the non-linear relationship between camera output and sensor temperature, which was affected by wind and temperature-drift during flight. The camera’s automated non-uniformity correction (NUC) could not sufficiently correct for these effects. Prominent vignetting was also visible in images captured under both stable and changing ambient conditions. The inconsistencies in camera output over time and across the sensor will affect camera applications based on relative temperature differences as well as user-generated radiometric calibration. Based on our findings, we present a set of best practices for UAV TIR camera sampling to minimize the impacts of the temperature dependency of these systems.

The paper presents two procedures for the wavelength calibration, in the oxygen telluric absorption spectral bands (O2-A, λc = 687 nm and O2-B, λc = 760.6 nm), of field fixed-point spectrometers used for reflectance and Sun-induced fluorescence measurements. In the first case, Ne and Ar pen-type spectral lamps were employed, while the second approach is based on a double monochromator setup. The double monochromator system was characterized for the estimation of errors associated with different operating configurations. The proposed methods were applied to three Piccolo Doppio-type systems built around two QE Pros and one USB2 + H16355 Ocean Optics spectrometers. The wavelength calibration errors for all the calibrations performed on the three spectrometers are reported and potential methodological improvements discussed. The suggested calibration methods were validated, as the wavelength corrections obtained by both techniques for the QE Pro designed for fluorescence investigations were similar. However, it is recommended that a neon emission line source, as well as an argon or mercury-argon source be used to have a reference wavelength closer to the O2-B feature. The wavelength calibration can then be optimised as close to the O2-B and O2-A features as possible. The monochromator approach could also be used, but that instrument would need to be fully characterized prior to use, and although it may offer a more accurate calibration, as it could be tuned to emit light at the same wavelengths as the absorption features, it would be more time consuming as it is a scanning approach.

This paper reports the results obtained for a distributed-feedback quantum cascade laser (DFB-QCL) exposed to different fluences of proton particles: 1014, 1015 and 1016 p/cm2. Dedicated laboratory setups were developed to assess the irradiation-induced changes in this device. Multiple parameters defining the QCL performances were investigated prior to and following each irradiation step: (i) voltage-driving current; (ii) emitted optical power-driving current; (iii) central emitting wavelength-driving current; (iv) emitted spectrum-driving current; (v) transversal mode structure-driving current, maintaining the system operating temperature at 20 °C. The QCL system presented, before irradiation, two emission peaks: a central emission peak and a side peak. After proton irradiation, the QCL presented a spectral shift, and the ratio between the two peaks also changed. Even though, after irradiation, the tunning spectral range was reduced, at the end of the tests, the system was still functional. [ABSTRACT FROM AUTHOR]

BaTiO3 (BTO) nanoparticles produced by wet chemistry methods were embedded in several types of flexible materials in order to fabricate flexible electronic devices. Starting from the produced nanoparticle dielectric properties, flexible material dielectric properties were tested for high electromagnetic frequencies (30 GHz–2 THz) using time domain spectroscopy. Dielectric performances of the different materials obtained with variable nanoparticle concentrations up to 40 wt.%, embedded in, gelatin, epoxy, and styrene-butadiene were compared at several working temperatures between 0 °C and 120 °C. Beside the general trend of ε′ decrease with temperature and loses increase with the operating frequency, we were able to identify few matrix dependent optimal nanoparticle concentrations. The best composite performances were achieved by the BTO-SBS matrix, with filler concentration of 2 wt.%, where the losses have been of 1.5%, followed by BTO-gelatin matrix, with filler concentration of 40 wt.%, with higher losses percent of almost 10% for THz frequencies. [ABSTRACT FROM AUTHOR]

The purpose of the study was to evaluate the properties of by-products obtained from the oil industry, to identify the content of bioactive compounds and to test the safety of their reintroduction in the food industry. Three sunflower meals obtained after cold-pressing of whole (WSM), partially dehulled (PSM) and total dehulled (TSM) sunflower seeds were used. A higher protein, ash and fiber content was obtained for WSM, followed by PSM, and TSM meals. Conversely, the lipid content was higher in TSM and PSM, and lower in WSM meals. Sunflower meals are important sources of unsaturated fatty acids (more linoleic than oleic acid), the content ranging between 82.74 and 86.72%. Additionally, sunflower meals represent a significant source of compounds with antioxidant activity. TSM showed the highest concentration of total polyphenols and total flavonoids, while WSM the lowest. The values of antioxidant activity were higher for TSM compared to PSM and WSM. The weak cytotoxic activity at concentrations lower than 6.25 mg/mL, as well as cell viability which is not affected by the action of PSM and TSM but even increases in the case of WSM, give sunflower meals the potential to be added as ingredients in the production of functional foods. [ABSTRACT FROM AUTHOR]

Sunflower (Helianthus annuus L.) crop is grown world wide, under a range of agro-environments. This crop is primarily grown for its edible oil but also for its achenes (confectionery types), both commonly used in human food. With ongoing climate change, sunflower, as a spring crop, could be more exposed to the direct effect of heat stress and to different drought scenarios, resulting in severe yield losses, oil content decrease and alteration of fatty acids composition. The oil concentration in sunflower (whether linoleic or oleic varieties) is valued above the contribution of genotype, of environment but also of the crop management. In our study, with different sunflower hybrids, experimented in different conditions of the environment, we obtained results on oil content and fatty acids composition. The oil content in kernels is influenced by climate. This depends by air temperature in period of anthesis or during grain filing, also by rainfall. The unsaturated fatty acids of sunflower oil are much more affected by genotype and environment than the saturated ones. Cooler regions offer a more favorable climate for the oil and linoleic acid synthesis. There is an indirect relationship for oleic and linoleic content, in sunflower oil. [ABSTRACT FROM AUTHOR]

New Er3+, Yb3+ codoped phosphate glasses with the (98-x) (0.50P2O5-0.40SrO-0.10Na2O) -0.5Er2O3-1.5Yb2O3-xZnO (in mol %) composition were prepared by melting process with up to 10 mol % of ZnO. The impact of the changes in the glass composition on the thermal, optical, structural properties was investigated. Using IR and Raman spectroscopies, we confirmed that the addition of ZnO up to 10 mol % leads to a depolymerization of the network without having a significant impact on the Er3+ and Yb3+ sites. We also discuss the effect of alpha particles irradiation. The glass with 2.5 mol % of ZnO was irradiated with 3 MeV alpha particles and a total fluence of 1012 α/cm2. After irradiation, this glass exhibits surface expansion (measured at ~200 nm, 1.5 months after the irradiation) and an increase in the surface roughness. The alpha particles irradiation is suspected to lead to changes in the spectroscopic properties of the glass. Finally, the photo-response of the glass was found to be reversible.

The consumer demand for healthy and natural products lead to the increased interest of consuming mountain food products. The objective of this work was to evaluate the physical-chemical and sensory characteristics of 8 dairy products and 11 meat products collected from different mountainous pastures from Romania. The protein content of dairy products varied between 37.39-47.90% d.m., while the fat content ranged between 43.63-49.57% d.m. For meat products, the protein content and fat content ranged between 11.69-70.07% d.m., and 17.58-95.92 % d.m., respectively. The fatty acid composition of mountain products was influenced by the pasture location, a better PUFA content being determined for products obtained from farms situated at a higher altitude. This research highlights that the quality of mountain products is strongly influenced by the pasture effects, the type of product analyzed and the technological process. [ABSTRACT FROM AUTHOR]

We demonstrated low-loss and single-mode laser beam delivery through hollow-core waveguides (HCWs) operating in the 3.7–7.6 μm spectral range. The employed HCWs have a circular cross section with a bore diameter of 200 μm and metallic/dielectric internal coatings deposited inside a glass capillary tube. The internal coatings have been produced to enhance the spectral response of the HCWs in the range 3.5–12 µm. We demonstrated Gaussian-like outputs throughout the 4.5–7.6 µm spectral range. A quasi single-mode output beam with only small beam distortions was achieved when the wavelength was reduced to 3.7 μm. With a 15-cm-long HCW and optimized coupling conditions, we measured coupling efficiencies of >88% and transmission losses of

The acrylamide (AA) content of potato chips (PCs), French fries (FF) ready‐to‐eat from fast‐foods and prepared in households consumed by the Romanian population was estimated and also AA intake by consuming such products. The mean AA content of PC, FF from fast‐food and prepared in households was 386.67, 149.55, and 530.32 µg/kg, respectively. 19% of PC and 50% of FF prepared in households exceeded the benchmark level set by EC (2017). Salt addition while frying potatoes, a potato:oil (P:O) ratio of 1:1 or 1:2, and soaking treatment application before frying the potatoes at maximum flame reduced significantly the AA level of FF from households. Between the AA level and the color parameters L*, a*, and ΔE* of FF prepared in households, significant correlations were found. The contribution to the total exposure to AA by consumption of PC and FF was 45%–73% of the maximum value estimated by EFSA. Novelty impact statement: This study reports the acrylamide (AA) level of potato‐based products for the first time in Romania after EC (2017) was implemented. The home preparation practices of French fries (FF) promote AA formation compared with the one of food business operators. Based on the mean level of AA obtained, PC and FF are considered to be the main contributors to dietary AA exposure. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the influence of some pre-treatment applications toward acrylamide mitigation in potatoes fried in domestic conditions modeled after those found in Romania, by using a pan and a fryer. Before being fried in a pan, potato strips were treated in one of the following ways: soaked in cold water for 15, 60, and 120 min (a); soaked in hot water at different combinations of temperatures and durations (60, 70, 80 °C for 5, 10, 15 min) (b); soaked in a NaCl solution (c), and; in a citric acid solution (d) both solutions of 0.05% and 1% concentration for 30 min. For potatoes fried in a fryer, the (a) pre-treatment and soaking in water at 80 °C for 5, 10, and 15 min were applied. Untreated samples were used as a control. French fries were analyzed in terms of moisture and acrylamide content, color, and texture parameters. The pre-treatments applied reduced the acrylamide content in French fries by 4–97% when fried in the pan and by 25–47% when fried in the fryer. Acrylamide content of French fries was negatively correlated with L* parameter and moisture content and positively correlated with a* parameter. The pre-treatments applied can be used successfully by consumers to reduce acrylamide content. [ABSTRACT FROM AUTHOR]

The radiation effects of electrons and protons on the spectroscopic and optical properties of oxide glasses doped with Yb3+ in various glass systems were investigated to understand the impact of the glass composition on the glass photo-response. Changes in the optical and emission properties were seen after the radiation treatment, and the magnitude of the changes depended on the irradiation source and dose. For all the investigated materials, the absorption coefficients in the 200–550 nm range increase post-irradiation, revealing the formation of defects in the glasses during the irradiation. While the spectroscopic properties of the tellurite glass remain unchanged, a small reduction in the Yb3+ emission intensity was seen after irradiating the phosphate, borosilicate, and germanate glasses, indicating that a reduction of Yb3+ to Yb2+ might occur in these glasses during the radiation treatment. The changes in the optical and spectroscopic properties after proton irradiation are small as they are localized at the surface of the glasses due to the shallow penetration depth of the proton in the glass. Even though the doses are small, the electron irradiation produces larger changes in the optical and spectroscopic properties since the electrons penetrate the entire volume of the glasses. All the changes in the optical and spectroscopic properties of the glasses were successfully reversed after a short heat treatment revealing the reversible nature of the photo-response of the investigated glasses. [ABSTRACT FROM AUTHOR]

In this paper, we propose a highly selective and efficient gas detection system based on a narrow-band IR metasurface emitter integrated with a resistive heater. In order to develop the sensor for the detection of specific gases, both the microheater and metasurface structures have been optimized in terms of geometry and materials. Devices with different metamaterial structures and geometries for the heater have been tested. Our prototype showed that the modification of the spectral response of metasurface-based structures is easily achieved by adapting the geometrical parameters of the plasmonic micro-/nanostructures in the metasurface. The advantage of this system is the on-chip integration of a thermal source with broad IR radiation with the metasurface structure, obtaining a compact selective radiation source. From the experimental data, narrow emission peaks (FWHM as low as 0.15 μm), corresponding to the CO2, CH4, and CO absorption bands, with a radiant power of a few mW were obtained. It has been shown that, by changing the bias voltage, a shift of a few tens of nm around the central emission wavelength can be obtained, allowing fine optimization for gas detection applications. [ABSTRACT FROM AUTHOR]

The aim of this study was to validate a GC-MS/MS method for determining acrylamide (AA) in potato-based products by using the solid-phase extraction (SPE) clean-up. The method consisted in defatting the sample (potato chips, French fries) with hexane, extraction of AA in water, centrifugation, followed by AA purification on two SPE columns. The purified extract was derivatized with bromine compounds, then extracted with ethyl acetate: hexane mixture. The residue dissolved in ethyl acetate and triethylamine was injected into the GC-MS/MS. The method showed a good precision (RSDr= 1.13-4.26%; RSDR= 1.19-8.84%) and accuracy (recovery= 85.64-109.22%). The precision of the results was demonstrated by participation in two proficiency tests launched by the FAPAS® program, yielding z-scores of -0.8 (for pre-cooked French fries) and 0 (for potato crisps). Good sensitivity was achieved for potato chips with a LOD and LOQ of 6.94 and 20.83 µg/kg, while for French fries, it was 10.29 and 30.87 µg/kg, respectively. When applying the method on potato chips sample, the AA level varied between undetectable and 1504.93 µg/kg, while for French fries was between 31.45-371.30 µg/kg. The method fulfilled the performance criteria of Commission Regulation EU 2017/2158 for the determination of AA in potato-based products. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the bread consumption, bread waste, and practices of reprocessing it in household by conducting an online survey, and based on the results it were chosen two ways of reprocessing wheat and rye bread through toasting: in the form of slices and croutons. In order to obtain safe products for consumers, the toasting effect on acrylamide (AA) level of the end product and correlations between AA and colour parameters (L*, a*, b*) were realized. Bread in the form of slices and croutons was toasted in the oven at 180°C for 10 and 20 min, respectively. AA content was determined by using GC-MS/MS method. The AA level of fresh wheat and rye bread were 13.23 µg/kg, and 73.19 µg/kg, respectively. By toasting the bread, the AA level increased for wheat bread at 13.35-21.28 µg/kg for slices and to 23.77-50.71 µg/kg for croutons, while for rye bread the AA level increased at 77.03-106.66 µg/kg for slices, and to 138.58-634.62 for croutons, respectively. In the case of sliced bread, all samples are safe for consumption in regards to AA level which was under the benchmark level established by EU Commission 2017/2158. For croutons, the rye bread toasted for 20 min at 180°C exceeded the AA benchmark level. In the case of sliced bread, there is a linear correlation between the colour parameter L* and the AA level (R²= 0.7520-0.8774). The shelf life of bread can be extended by reprocessing, but the AA level increases by subjecting it to thermal processing. The AA level and colour parameters of reprocessed bread is influenced by the processing conditions, the type of flour used in the recipe, and also the way of cutting it. [ABSTRACT FROM AUTHOR]

This study reports the acrylamide (AA) content of some cereal-based products purchased from different Romanian suppliers. The AA level was determined by using gas chromatography tandem mass spectrometry (GC-MS/MS) in SRM mode. The analytical method was characterized by a high degree of sensitivity (limit of detection (LOD) = 1.23 µg/kg, and limit of quantification (LOQ) = 3.70 µg/kg). A total of 46 food samples of bread, biscuits, and similar products (doughnuts, cakes, cookies etc.) were analysed. The results showed that the AA level varied between food samples, for soft bread (5.63 - 85.05 µg/kg), biscuits (8.55 - 548.80 µg/kg), crackers (13.92 - 167.58 µg/kg) and for similar products (12.57 - 99.01 µg/kg) which were lower than the benchmark levels set by the Commission Regulation (EU) 2017/2158. The highest AA content (548.80 µg/kg) was found for biscuits, while the lowest AA content (5.63 µg/kg) was obtained for wheatbased bread. From the analysed products, 4 biscuit samples exceeded the benchmark levels of 350 µg/kg established by European Union. [ABSTRACT FROM AUTHOR]

The paper presents two procedures for the wavelength calibration, in the oxygen telluric absorption spectral bands (O2-A, λc = 687 nm and O2-B, λc = 760.6 nm), of field fixed-point spectrometers used for reflectance and Sun-induced fluorescence measurements. In the first case, Ne and Ar pen-type spectral lamps were employed, while the second approach is based on a double monochromator setup. The double monochromator system was characterized for the estimation of errors associated with different operating configurations. The proposed methods were applied to three Piccolo Doppio-type systems built around two QE Pros and one USB2 + H16355 Ocean Optics spectrometers. The wavelength calibration errors for all the calibrations performed on the three spectrometers are reported and potential methodological improvements discussed. The suggested calibration methods were validated, as the wavelength corrections obtained by both techniques for the QE Pro designed for fluorescence investigations were similar. However, it is recommended that a neon emission line source, as well as an argon or mercury-argon source be used to have a reference wavelength closer to the O2-B feature. The wavelength calibration can then be optimised as close to the O2-B and O2-A features as possible. The monochromator approach could also be used, but that instrument would need to be fully characterized prior to use, and although it may offer a more accurate calibration, as it could be tuned to emit light at the same wavelengths as the absorption features, it would be more time consuming as it is a scanning approach. [ABSTRACT FROM AUTHOR]

New Er3+, Yb3+ codoped phosphate glasses with the (98-x) (0.50P2O5-0.40SrO-0.10Na2O) -0.5Er2O3-1.5Yb2O3-xZnO (in mol %) composition were prepared by melting process with up to 10 mol %of ZnO. The impact of the changes in the glass composition on the thermal, optical, structural properties was investigated. Using IR and Raman spectroscopies, we confirmed that the addition of ZnO up to 10 mol % leads to a depolymerization of the network without having a significant impact on the Er3+ and Yb3+ sites. We also discuss the effect of alpha particles irradiation. The glass with 2.5 mol % of ZnO was irradiated with 3 MeV alpha particles and a total fluence of 1012 α/cm². After irradiation, this glass exhibits surface expansion (measured at ***200 nm, 1.5 months after the irradiation) and an increase in the surface roughness. The alpha particles irradiation is suspected to lead to changes in the spectroscopic properties of the glass. Finally, the photo-response of the glass was found to be reversible. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the influence of wheat flour extraction degree and baking parameters on acrylamide (AA) level in biscuits by using gas chromatography tandem mass spectrometry (GC-MS/MS). Color parameters were analyzed in an attempt to establish correlations with the investigated factors. Biscuits baked between 25 min ÷ 60 min at 200°C recorded values of AA level < LOD (4.63 μg/kg) to about 1.580 μg/kg. By baking biscuits at a temperature varying between 220°C ÷ 240°C for 20 min the AA level increased from 67.44 to 212.87 μg/kg. The highest AA level and the darkest color was obtained when using in the biscuits recipe the whole-wheat flour (F3) with an ash content of 2.37% d.m. (1580.33 μg/kg, ΔE*= 35.66), followed by white flour F1 with 0.53% d.m. (387.82 μg/kg, ΔE* = 61.79), respectively F2 with 0.44% d.m. (308.38 μg/kg, ΔE* = 67.47). From the results obtained it can be said that the AA level is strongly influenced by biscuits baking parameters (temperature and baking time) and by the ash content of wheat flour used in the manufacture recipe. [ABSTRACT FROM AUTHOR]

We demonstrated low-loss and single-mode laser beam delivery through hollow-core waveguides (HCWs) operating in the 3.7–7.6 μm spectral range. The employed HCWs have a circular cross section with a bore diameter of 200 μm and metallic/dielectric internal coatings deposited inside a glass capillary tube. The internal coatings have been produced to enhance the spectral response of the HCWs in the range 3.5–12 μm. We demonstrated Gaussian-like outputs throughout the 4.5–7.6 μm spectral range. A quasi single-mode output beam with only small beam distortions was achieved when the wavelength was reduced to 3.7 μm. With a 15-cm-long HCW and optimized coupling conditions, we measured coupling efficiencies of >88% and transmission losses of <1 dB in the investigated infrared spectral range. [ABSTRACT FROM AUTHOR]