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The response functions (RFs) of a Bonner Sphere Spectrometer (BSS) with a 6LiI thermal neutron detector were calculated using the Monte Carlo codes PHITS (version 3.26) and MCNPX (version 2.7.0), with their own default nuclear data libraries, and physics models. RFs were compared with other published data, obtained for the same spectrometer using the MCNP6.1 code with its own physics models. A discussion on the influence of using different nuclear data libraries and physics models using these codes/versions is analyzed.

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Accurate and reliable measurements of optical properties are crucial for a wide range of industrial and commercial applications. However, external illumination fluctuations can often make these measurements challenging to obtain. This work proposes a new technique based on digital lock-in processing that enables the use of CCD spectrometers in optical spectroscopy applications, even in uncontrolled lighting conditions. This approach leverages digital lock-in processing, performed on each pixel of the spectrometer's CCD simultaneously, to mitigate the impact of external optical interferences. The effectiveness of this method is demonstrated by testing and recovering the spectrum of a yellow LED subjected to other light sources in outdoor conditions, corresponding to a Signal-to-Noise Ratio of -70.45 dB. Additionally, it was possible to demonstrate the method's applicability for the spectroscopic analysis of gold nanoparticles in outdoor conditions. These results suggest that the proposed technique can be helpful for a wide range of optical measurement techniques, even in challenging lighting conditions.

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Venoms from tarantulas contain low molecular weight vasodilatory compounds whose biological action is conceived as part of the envenomation strategy due to its propagative effects. However, some properties of venom-induced vasodilation do not match those described by such compounds, suggesting that other toxins may cooperate with these ones to produce the observed biological effect. Owing to the distribution and function of voltage-gated ion channels in blood vessels, disulfide-rich peptides isolated from venoms of tarantulas could be conceived into potential vasodilatory compounds. However, only two peptides isolated from spider venoms have been investigated so far. This study describes for the first time a subfraction containing inhibitor cystine knot peptides, PrFr-I, obtained from the venom of the tarantula Poecilotheria regalis. This subfraction induced sustained vasodilation in rat aortic rings independent of vascular endothelium and endothelial ion channels. Furthermore, PrFr-I decreased calcium-induced contraction of rat aortic segments and reduced extracellular calcium influx to chromaffin cells by the blockade of L-type voltage-gated calcium channels. This mechanism was unrelated to the activation of potassium channels from vascular smooth muscle, since vasodilation was not affected in the presence of TEA, and PrFr-I did not modify the conductance of the voltage-gated potassium channel Kv10.1. This work proposes a new envenomating function of peptides from venoms of tarantulas, and establishes a new mechanism for venom-induced vasodilation.

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BACKGROUND AND AIM: Echinodorus macrophyllus (Kunth.) Micheli is popularly used for acute and chronic inflammatory conditions. The anti-inflammatory activity was previously demonstrated for its flavonoid-enriched fractions. The aim of this work assessed the antinociceptive properties of both aqueous extract and its fractions. EXPERIMENTAL PROCEDURE: The antinociceptive activity was determined by acetic acid-induced writhing, formalin test, tail immersion test, hot-plate test, xylene-induced ear edema methods, and the evaluation of its mechanism was performed in the writhing model. The aqueous extract of Echinodorus macrophyllus (AEEm) was fractionated, yielding Fr20, and Fr40. Fr40 composition was determined by HPLC-DAD-ESI-MS. RESULTS AND CONCLUSION: Fr20 (all doses) and Fr40 (100 mg/kg) reduced the nociception in the tail-flick model. Both fractions increased the percentage of maximum possible effect with 25 mg/kg, in the hot-plate assay, at 60 min, while AEEm reduced pain only with 50 and 100 mg/kg. There was a reduction in xylene-edema index, with Fr40 (25 mg/kg), AEEm (50 mg/kg) and Fr20 (50 mg/kg). All doses of AEEm, Fr20, and Fr40 reduced both phases of the formalin model. In the abdominal contortion model, Fr40 presented the highest activity, reducing 96% of contortions and its antinociceptive mechanism was evaluated. The results indicated the involvement of NO and adrenergic activation pathways. The main components of Fr40 are swertisin, swertiajaponin, isoorientin 7,3'-dimethyl ether, swertisin-O-rhamnoside, isoorientin, isovitexin, isovitexin-Orhamnoside, and isovitexin-7-O-glucoside. The aqueous extract of E. macrophyllus leaves and its fractions exhibited significant analgesic effect, mediated through both peripheral and central mechanisms being considered a potentially antinociceptive drug.

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A computational simulation of alpha-particle expansion, emitted by 222Rn naturally diluted in the water of a spring located in the state of Puebla Mexico, is presented. This simulation provided information on the volume of expansion of the alpha particles in the vicinity of the spring and thus awareness if there was a radiological risk for the users or the population that lived near to it. Before performing the simulation, several measurements were made to water samples with a dynamic measurement system. This in order to know the level of radon concentration and compare the results obtained with the levels recommended by the United States Environmental Protection Agency (US-EPA) and the World Health Organization (WHO). In addition, to know if there was a radiological risk due to the presence of gamma emitting radionuclides, complementary water analyses were carried out using gamma-ray spectrometry techniques. The simulation was developed using the scientific software of particle interaction with matter, Geant4. The different variables declared for the software parameters are presented in this document. The results of the radon measurements in the water and the computational simulation, determined that there was no radiological risk due to alpha radiation. Furthermore, the results from the gamma-ray spectrometer showed that there was no presence of other hazardous radionuclides in the water.

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In this study, daily changes over a short period and diurnal progression of spectral reflectance at the leaf level were used to identify spring wheat genotypes (Triticum aestivum L.) susceptible to adverse conditions. Four genotypes were grown in pots experiments under semi-controlled conditions in Chile and Spain. Three treatments were applied: i) control (C), ii) water stress (WS), and iii) combined water and heat shock (WS+T). Spectral reflectance, gas exchange and chlorophyll fluorescence measurements were performed on flag leaves for three consecutive days at anthesis. High canopy temperature ( H CT ) genotypes showed less variability in their mean spectral reflectance signature and chlorophyll fluorescence, which was related to weaker responses to environmental fluctuations. While low canopy temperature ( L CT ) genotypes showed greater variability. The genotypes spectral signature changes, in accordance with environmental fluctuation, were associated with variations in their stomatal conductance under both stress conditions (WS and WS+T); L CT genotypes showed an anisohydric response compared that of H CT , which was isohydric. This approach could be used in breeding programs for screening a large number of genotypes through proximal or remote sensing tools and be a novel but simple way to identify groups of genotypes with contrasting performances.

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One of the most important types of evidence in certain criminal investigations is traces of human blood. For a detailed investigation, blood samples must be identified and collected at the crime scene. The present study aimed to evaluate the potential of the identification of human blood in stains deposited on different types of floor tiles (five types of ceramics and four types of porcelain tiles) using a portable NIR instrument. Hierarchical models were developed by combining multivariate analysis techniques capable of identifying traces of human blood (HB), animal blood (AB) and common false positives (CFP). The spectra of the dried stains were obtained using a portable MicroNIR spectrometer (Viavi). The hierarchical models used two decision rules, the first to separate CFP and the second to discriminate HB from AB. The first decision rule, used to separate the CFP, was based on the Q-Residual criterion considering a PCA model. For the second rule, used to discriminate HB and AB, the Q-Residual criterion were tested as obtained from a PCA model, a One-Class SIMCA model, and a PLS-DA model. The best results of sensitivity and specificity, both equal to 100%, were obtained when a PLS-DA model was employed as the second decision rule. The hierarchical classification models built for these same training sets using a PCA or SIMCA model also obtained excellent sensitivity results for HB classification, with values above 94% and 78% of specificity. No CFP samples were misclassified. Hierarchical models represent a significant advance as a methodology for the identification of human blood stains at crime scenes.

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AIM AND OBJECTIVE: The purpose of this study was to measure the refractive index of four commercially available enamel resin composites, using optical coherence tomography (OCT) and their relationship with the atomic composition of the composite resin fillers utilizing an energy-dispersive X-ray fluorescence spectrometer (EDX). MATERIALS AND METHODS: Four different enamel composites, namely Enamel HRi color UE3, Enamel HFO color GE3, Vit-l-escence color Pearl Frost, and Amelogen Plus color Enamel White were tested. For each composite, disks with different thicknesses were fabricated and then light-cured according to the manufacturer's instructions. The disks were then stored in deionized water under 36.5 °C for at least 7 days. Each of the samples from the four different groups was measured in five distinctive points to analyze the optical and physical length using optical coherence tomography (OCT). Elemental analysis of all four different enamel shades of the composite was done using an EDX. RESULTS: The filler contents showed interesting differences in elemental composition and concentration; however, Si seemed to be a common filler component. The HRi composite presented a distinctive composition compared to other materials and was the only composite that showed a smaller percentage of SiO2, and also was the only composite that contained compounds, such as P2O5, ZnO, CaO, La2O3, and V2O5. The optical coherence tomography analysis showed the refractive index values of all tested enamel composites. Among the four different enamel composite resins tested, the enamel HRi composite demonstrated the most ideal refractive index to mimic natural enamel. CONCLUSION: The enamel HRi composite demonstrated a distinctive filler composition and this could be the main reason behind its higher refractive index. Nonetheless, it remains unclear how much of an impact this feature has in the final esthetic outcome of anterior composite restorations, where many other optical phenomena are also important. CLINICAL SIGNIFICANCE: The clinical success of any esthetic restorative procedure depends on diagnosing the proper treatment plan and also on executing this treatment with the right materials. On direct esthetic restorations, knowing the optical properties of such materials is fundamental, as they should be able to replicate both natural enamel and dentin. How to cite this article: Beolchi RS, Mehta D, Pelissier B, et al. Influence of Filler Composition on the Refractive Index of Four Different Enamel Shades of Composite Resins. J Contemp Dent Pract 2021;22(5):557-561.

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Purpose To evaluate the effect of glass-reinforced ceramics (leucite and lithium disilicate) with different thicknesses (1, 2, and 3 mm) on the wavelength and irradiance spectrum of blue and violet lights. In addition, the effect of the ceramics on four current light-curing units (LCUs) was evaluated: a halogen lamp, a single peak LED, and two multi-peak LEDs.Methods Ceramic discs of different thicknesses (1, 2, and 3 mm) were obtained from computer-aided design and computer-aided manufacturing (CAD-CAM) blocks. The irradiance, radiant exposure, and emission spectrum of the four LCUs were analyzed using a spectrometer-based instrument. To evaluate the violet and blue lights, a specific device that provides a narrow emission spectrum was used.Results The ceramics reduced the irradiance of all the tested LCUs. However, the wavelength of the transmitted light was only altered slightly. The effect of leucite and lithium disilicate varied according to the type of LCU and thickness of the ceramic disc evaluated .Conclusions From the results, it could be concluded that the thickness of the leucite and lithium disilicate ceramic significantly reduced the irradiance of the light emitted by the LCUs, with minimal changes on the wavelength spectrum of the lights. The effects of the ceramic on irradiance and transmitted wavelengths of the blue and violet lights was slightly different.

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The presence of substances such as hormones and toxic metal in aquatic ecosystem is interesting to the scientific community due to their adverse effects. We quantified 17α-ethynylestradiol (EE2) and toxic metals in the surface waters from Sorocaba and Pirajibu Rivers, in São Paulo State, and we estimated the daily intake for hormone, based on the amount of water consumed. EE2, Cd, Hg, As, Pb, and Mn were seasonally quantified in six different locations along the rivers. EE2 was evaluated by high-performance liquid chromatography. Toxic metals were determined by inductively coupled plasma mass spectrometer. Considering the entire sample year, EE2 concentrations ranged from 4.5 to 48.2 µg L-1. Comparing Sorocaba and Pirajibu rivers, the sample point in the entrance of the Pirajibu River through the city of Itu, São Paulo State, had higher amounts of EE2. Regarding metals, all results are according to the Brazilian and World Health Organization guidelines for drinking-water quality, except for Mn levels, which were higher than the limits in Autumn season in two locations. The estimated daily intake ranged from 13.45 to 40.9 µg/day/person. In conclusion, concentrations of EE2 in the Sorocaba and Pirajibu Rivers were higher than in other countries. The levels were as high as an intake of one pill for each person every day (considering an oral contraceptive has 0.03 mg of ethinylestradiol). Even though concentrations of toxic elements are in accordance with the Brazilian Regulation and World Health Organization, legislation for hormones and drugs needs to advance.

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One of the most important contributions of forensic entomology is to assist criminal expertise to determine the postmortem interval, which depends on the duration of the immature stages of insects of forensic interest. On the other hand, the time of development of the different stages varies according to the species; therefore, its identification is essential. Currently, few studies have investigated the use of cuticular hydrocarbons, and none regarding fatty acids, as complementary taxonomic tools to expedite species identification. Therefore, we evaluated whether cuticular hydrocarbons together with fatty acids of eggs of flies of the family Calliphoridae, main group of forensic interest, can be used to distinguish species. The analyses were performed by chromatographic techniques. The results show that there are significant differences between the composition of cuticular hydrocarbons and fatty acids between species and, therefore, they can be used to provide a complementary taxonomic tool to expedite the forensic expertise.

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Fruit peels of Plinia cauliflora (Mart.) Kausel are widely used in Brazilian traditional medicine, but no studies have proved the safety of its pharmacological effects on the respiratory, cardiovascular, and central nervous systems. The present study assessed the safety pharmacology of P. cauliflora in New Zealand rabbits. First, an ethanol extract (EEPC) was selected for the pharmacological experiments and chemical characterization. Then, different groups of rabbits were orally treated with EEPC (200 and 2000 mg/kg) or vehicle. Acute behavioral and physiological alterations in the modified Irwin test, respiratory rate, arterial blood gas, and various cardiovascular parameters (i.e., heart rate, blood pressure, and electrocardiography) were evaluated. The main secondary metabolites that were identified in EEPC were ellagic acid, gallic acid, O-deoxyhexosyl quercetin, and the anthocyanin O-hexosyl cyanidin. No significant behavioral or physiological changes were observed in any of the groups. None of the doses of EEPC affected respiratory rate or arterial blood gas, with no changes on blood pressure or electrocardiographic parameters. The present study showed that EEPC did not cause any significant changes in respiratory, cardiovascular, or central nervous system function. These data provide scientific evidence of the effects of this species and important safety data for its clinical use.

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Biofilm formation on exposed surfaces is a serious issue for the food industry and medical health facilities. There are many proposed strategies to delay, reduce, or even eliminate biofilm formation on surfaces. The present study focuses on the applicability of fire ant venom alkaloids (aka 'solenopsins', from Solenopsis invicta) tested on polystyrene and stainless steel surfaces relative to the adhesion and biofilm-formation by the bacterium Pseudomonas fluorescens. Conditioning with solenopsins demonstrates significant reduction of bacterial adhesion. Inhibition rates were 62.7% on polystyrene and 59.0% on stainless steel surfaces. In addition, solenopsins drastically reduced cell populations already growing on conditioned surfaces. Contrary to assumptions by previous authors, solenopsins tested negative for amphipathic properties, thus understanding the mechanisms behind the observed effects still relies on further investigation.

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AIMS: To compare the dosage of radiation the thyroid and gonad glands receive in pediatric patients undergoing chest X-rays, in distinct positions, towards the goal of developing of an X-ray tube positioning protocol. METHODS: A randomized controlled clinical trial was carried out in the Pediatric Intensive Care Unit (PICU) at the Institute of Cardiology/University Foundation of Cardiology of Rio Grande do Sul, Brazil from June 2014 to September 2016. Patients were divided into two groups. One group was positioned with the thyroid gland facing the anode end of an X-ray tube, and in the other group the thyroid gland faced the cathode end. Radiographs were evaluated by five observers, following criteria recommended by the Commission of the European Communities (CEC). RESULTS: Forty-eight pediatric patients, with a mean age of 2.0 ±â€¯1.3 years, participated in this study. Based on the evaluation of 48 images, it was determined that the thyroid and gonad glands facing the cathode were exposed to 13.3 ±â€¯3.1 µGy and 13.5 ±â€¯4.1 µGy of radiation, respectively (p = 0.008). Additionally, the thyroid and gonad glands facing the anode were exposed to 11.7 ±â€¯3.1 µGy and 12.7 ±â€¯3.1 µGy of radiation, respectively (p = 0.007). The mean input dose in the center of the chest was 20.8 ±â€¯9.6 µGy in both positions. DISCUSSION: The proximity of the thyroid gland to the cathode end of the X-ray tube appears to be related to the dosage of ionizing radiation. Adverse effects associated with exposure to ionizing radiation could be minimized by positioning the thyroid gland to the anodic end of the X-ray tube. CONCLUSION: Patients should be placed facing the anode end of the X-ray tube when taking thoracic X-rays, in order to reduce radiation exposure to the thyroid and gonad glands.ClinicalTrials.gov Identifier: NCT02925936.

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The sequential extraction procedure of the Community Bureau of Reference (BCR) was applied to investigate the mobility of potentially toxic elements (As, Cd, Cr, and Pb) and nutrients (P, Ca, Mg, Cu, Fe, Mn, and Zn) in a multinutrient mineral fertilizer based on phosphate rocks supplemented with 10% (w w-1) micronutrient mixture (raw material used as a micronutrient source). For both samples, As and Cd were more mobile, whereas Cr remained in the solid residue. A higher mobility of Pb was observed in the micronutrient mixture; however, the high concentration of P (8.3% w w-1) in the fertilizer could have decreased Pb mobility as a result of Pb3(PO4)2 formation. The nutrients had great mobility, except Fe, which remained almost totally in the residual fraction in both samples. X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analyses of solid residues showed that the ways in which elements were distributed in the sample particles could affect their mobility.

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OBJECTIVE: To assess light irradiance (LI) delivered by two light-curing units (LCU's) and to measure the degree of conversion (DC) of three composite cements, when cured through different thicknesses of two novel CAD-CAM block materials. METHODS: 100-µm-thick films of a dual-curable composite cement (G-CEM LinkAce, GC), a light-curable flowable resin-based composite (RBC) (G-ænial Universal Flo, GC) and a micro-hybrid RBC (G-ænial Posterior, GC) were investigated as luting agents. Two 'polymer-ceramic' CAD-CAM blocks (Cerasmart, GC; Enamic, Vita Zahnfabrik) were sectioned in slabs with different thicknesses (1, 3 and 5mm). LI at the bottom of the specimens was measured using a calibrated spectrometer, while being light-cured through the CAD-CAM block slabs for 40s with a low- (±500mW/cm2) or high- (±1,600mW/cm2) irradiance LCU (n=5). After light-curing, micro-Raman spectra of the composite films were acquired to determine DC at 5min, 10min, 1h and 24h. LI data were statistically analyzed by Kruskal-Wallis followed by post-hoc comparisons, while a linear mixed-effect model was applied for the DC analysis. In addition, the CAD-CAM blocks ultrastructure was characterized upon argon-ion slicing using scanning transmission electron microscopy (STEM). Finally, light transmission (LT) through each CAD-CAM block material was assessed using a spectrophotometer. RESULTS: Curing-light attenuation and DC were significantly influenced by thickness and type of the overlying material. LCU only had a significant effect on DC of the micro-hybrid RBC. DC significantly increased over time for all composite cements. CAD-CAM block structural analysis revealed a relatively small and homogenous filler configuration (mean filler size of 0.2-0.5µm) for Cerasmart, while Enamic contained ceramic grains varying in shape and size (1-10µm), which were interconnected by the polymer-based network. LT was much higher at a wavelength range of 300-800nm for Cerasmart than for Enamic. SIGNIFICANCE: Light-curable composite cements can be cured through a restoration up to 2.7-mm thickness, depending on the kind of CAD-CAM material. A high-irradiance LCU only has a limited effect on the maximum thickness of the polymer-ceramic CAD-CAM material that can be cured through.

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Nitrogen (N) has commonly been applied in Eucalyptus stands in Brazil and it has a direct relation with biomass production and chlorophyll content. Foliar N concentrations are used to diagnose soil and plant fertility levels and to develop N fertilizer application rates. Normally, foliar N is obtained using destructive methods, but indirect analyses using Vegetation Indexes (VIs) may be possible. The aim of this work was to evaluate VIs to estimate foliar N concentration in three Eucalyptus clones. Lower crown leaves of three clonal Eucalyptus plantations (25 months old) were classified into five color patterns using the Munsell Plant Tissue Color Chart. For each color, N concentration was determined by the Kjeldahl method and foliar reflectance was measured using a CI-710 Miniature Leaf Spectrometer. Foliar reflectance data were used to obtain the VIs and the VIs were used to estimate N concentrations. In the visible region, the relationship between N concentration and reflectance percentage was negative. The highest correlations between VIs and N concentrations were obtained by the Inflection Point Position (IPP, r = 0.97), Normalized Difference Red-Edge (reNDVI, r = 0.97) and Modified Red-Edge Normalized Difference Vegetation Index (mNDI, r = 0.97). Vegetation indexes on the red edge region provided the most accurate estimates of foliar N concentration. The reNDVI index provided the best N concentration estimates in leaves of different colors of Eucalyptus urophylla × grandis and Eucalyptus urophylla × urophylla (R2 = 0.97 and RMSE = 0.91 g kg1).

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Nitrogen (N) has commonly been applied in Eucalyptus stands in Brazil and it has a direct relation with biomass production and chlorophyll content. Foliar N concentrations are used to diagnose soil and plant fertility levels and to develop N fertilizer application rates. Normally, foliar N is obtained using destructive methods, but indirect analyses using Vegetation Indexes (VIs) may be possible. The aim of this work was to evaluate VIs to estimate foliar N concentration in three Eucalyptus clones. Lower crown leaves of three clonal Eucalyptus plantations (25 months old) were classified into five color patterns using the Munsell Plant Tissue Color Chart. For each color, N concentration was determined by the Kjeldahl method and foliar reflectance was measured using a CI-710 Miniature Leaf Spectrometer. Foliar reflectance data were used to obtain the VIs and the VIs were used to estimate N concentrations. In the visible region, the relationship between N concentration and reflectance percentage was negative. The highest correlations between VIs and N concentrations were obtained by the Inflection Point Position (IPP, r = 0.97), Normalized Difference Red-Edge (reNDVI, r = 0.97) and Modified Red-Edge Normalized Difference Vegetation Index (mNDI, r = 0.97). Vegetation indexes on the red edge region provided the most accurate estimates of foliar N concentration. The reNDVI index provided the best N concentration estimates in leaves of different colors of Eucalyptus urophylla × grandis and Eucalyptus urophylla × urophylla (R2 = 0.97 and RMSE = 0.91 g kg1).(AU)

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The interest in performing in field measures using portable instruments is growing increasingly. Calibration transfer techniques can be used to enable models, predicted values or spectra obtained in a benchtop instrument be used in portable instrument, saving money and time required for a complete recalibration. Most of the calibration transfer methods require a set of transfer samples which spectra have to be acquired in both spectrometers. The present work evaluates the use of virtual standards as transfer samples in the reverse standardization (RS) method in order to standardize very dissimilar spectral responses of fuel samples (gasoline and biodiesel blends) from a high-resolution benchtop Frontier FT-NIR (PerkinElmer) spectrometer and a handheld MicroNIR™1700 (JDSU). These virtual standards can be created by mathematically mixing spectra from the pure solvents present in gasoline or diesel/biodiesel (D/B) blends, to avoid volatilization and changes in the composition of the compounds during storage and/or transportation of the real transfer fuel samples. Virtual standards were created using ten and five pure solvents for gasoline and D/B blends, respectively. Partial least squares regression (PLS) models were built for five quality parameters of gasoline (distillation temperatures at 10%, 50%, 90% and final boiling point (FBP) volume recovered and density) and one of D/B blends (biodiesel content). The RMSEP values obtained after the standardization approaches were equivalent to the reproducibility of the reference methods, except for density and biodiesel content parameters obtained for the virtual samples standardization approach. RS procedure provided promising results showing that it is possible to transfer gasoline or D/B blend spectra acquired with a high-resolution benchtop instrument to the handheld MicroNIR using virtual standards as transfer samples.

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This study outlines an experimental method for landfill volatile organic compounds (VOCs) characterization by means of a portable time-of-flight mass spectrometer in an insular tropical environment. The concentrations of six VOCs, three aromatic and three chlorinated compounds, frequently identified in landfill gas plume were determined in the main municipal solid waste of Guadeloupe archipelago and its surrounding areas (in the Leeward Islands). Measurements were carried out for various stages of waste degradation. Without mechanical forcing on the waste piles, the results for aromatic and chlorinated compounds showed much higher concentrations at covered waste. Benzene, toluene and ethylbenzene were easily detected by the portable mass spectrometer in the air matrix with concentrations significantly greater than the equipment limit of detection (LOD) estimates. Trichloroethylene is not often measured by the mass spectrometer and very few calculated concentrations reach the instrument LOD. For sites near the landfill, using the sum trichloroethylene + tetrachlororethylene as tracer, it was observed that the most affected locations are under the wind of the landfill plume. Moreover, under certain atmospheric conditions, most of the surrounding area, downwind and upwind, can undergo an increase of the tracer concentration levels, as shown in the paper during a dust outbreak.

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