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Rationale: Stable carbon and oxygen isotope data of biogenic and abiogenic aragonite are of fundamental relevance in paleoclimate research. Wet‐chemical analysis of such materials requires well‐homogenized, fine‐grained powder. In the present study, the effect of different grinding/milling methods on sample homogeneity and the potential risk of unintentional calcite formation and isotope shift were evaluated. Methods: Shells of Arctica islandica and aragonite sputnik crystals were pulverized using a set of commonly used methods, including a hand‐held drill, a vibromill operated at various settings (with and without liquid nitrogen cooling, changes in ball diameters, frequencies, and processing durations), and an agate mortar and pestle. Stable isotope values were measured using an isotope ratio mass spectrometer operated in continuous flow mode. Identification of mineral phases was obtained by powder X‐ray diffraction (PXRD), Raman spectroscopy, and attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy. Calcite content was quantified by PXRD Rietveld refinement. Results: Samples showed substantial homogeneity, in particular after vibromilling (duration 3–10 min). More vigorous grinding resulted in larger fractions of calcite (0.5–4.2 wt%) and a concomitant δ18O and δ13C decrease, specifically in bivalve shells. The only method for producing pure aragonite powder was by pounding the aragonite sputniks manually with an agate mortar and pestle. Conclusions: None of the studied, commonly used machine‐based pulverization methods produced pure aragonite powder from samples consisting originally of aragonite. These findings have significant implications for light‐stable isotope‐based paleoclimate reconstructions. Except for abiogenic aragonite powder produced by pounding in an agate mortar, paleotemperatures would be overestimated. [ABSTRACT FROM AUTHOR]

Hydrogen heralded as a promising renewable and environmentally friendly energy carrier, carries inherent risks owing to its highly flammable nature. A mere 4 % concentration of hydrogen in the air can trigger an explosion. To counteract this peril, a composite material comprising PbOX‐ZnO (2 : 1) was synthesized, characterized, and subsequently employed to fabricate a hydrogen sensing device. Various analytical tools were used to characterize as‐deposited materials, including X‐ray diffraction, Scanning electron microscopy /Energy Dispersive X‐ray Spectroscopy, Transmission electron microscopy UV‐Vis Reflectance Spectroscopy and Fourier‐transform infrared spectroscopy. The device exhibited favorable properties, such as good selectivity, stability, and a low detection limit for hydrogen. At ambient room temperature, the device demonstrated a sensing signal reaching 468.7, with a response time (T90) of 155 seconds and a recovery time (Tr90) of 69 seconds when exposed to a hydrogen concentration of 5 ppm. This performance underscores the device's rapid and effective response to hydrogen exposure. Moreover, the PbOX‐ZnO (2 : 1) composite‐based device exhibited a detection limit of 2.4 ppm, functioning accurately within a linear range spanning from 5 ppm to 50 ppm. This capability confirms its precision in accurately detecting hydrogen concentrations within this designated range. [ABSTRACT FROM AUTHOR]

The accelerated weathering of flax and miscanthus fibers possessing distinct chemical compositions was investigated. The chosen fibers included raw, extractive-free (EF) and delignified samples (x3), alone and used as fillers in a stabilized polypropylene blue matrix (PP). Modifications in both color and the chemical composition of the fibers throughout the weathering process under ultraviolet (UV) light were meticulously tracked and analyzed by spectrophotometry and attenuated total reflectance with Fourier-transform infrared spectroscopy (ATR-FTIR). The inherent nature and composition of the selected fibers led to varied color-change tendencies. Raw and EF flax fibers exhibited lightening effects, while raw and EF miscanthus fibers demonstrated darkening effects. Extractives exhibited negligible influence on the color alteration of both flax and miscanthus fibers. This disparity between the fibers correlates with their respective lignin content and type, and the significant formation of carbonyl (C=O) groups in miscanthus. Better stability was noted for delignified flax fibers. A comparative study was achieved by weathering the PP matrix containing these various fibers. Contrary to the weathering observations on individual fibers, it was noted that composites containing raw and EF flax fibers exhibited significant color degradation. The other fiber-containing formulations showed enhanced color stability when compared to the pure PP matrix. The study highlights that the UV stability of composites depends on their thermal history. As confirmed by thermogravimetric analysis (TGA), fiber degradation during extrusion may affect UV stability, a factor that is not apparent when fibers alone are subjected to UV aging. [ABSTRACT FROM AUTHOR]

Background: Rapid monitoring of biomass conversion processes using techniques such as near-infrared (NIR) spectroscopy can be substantially quicker and less labor-, resource-, and energy-intensive than conventional measurement techniques such as gas or liquid chromatography (GC or LC) due to the lack of solvents and preparation methods, as well as removing the need to transfer samples to an external lab for analytical evaluation. The purpose of this study was to determine the feasibility of rapid monitoring of a biomass conversion process using NIR spectroscopy combined with multivariate statistical modeling, and to examine the impact of (1) subsetting the samples in the original dataset by process location and (2) reducing the spectral range used in the calibration model on model performance. Results: We develop multivariate calibration models for the concentrations of soluble xylo-oligosaccharides (XOS), monomeric xylose, and total solids at multiple points in a biomass conversion process which produces and then purifies XOS compounds from sugar cane bagasse. A single model using samples from multiple locations in the process stream showed acceptable performance as measured by standard statistical measures. However, compared to the single model, we show that separate models built by segregating the calibration samples according to process location show improved performance. We also show that combining an understanding of the sample spectra with simple multivariate analysis tools can result in a calibration model with a substantially smaller spectral range that provides essentially equal performance to the full-range model. Conclusions: We demonstrate that real-time monitoring of soluble xylo-oligosaccharides (XOS), monomeric xylose, and total solids concentration at multiple points in a process stream using NIR spectroscopy coupled with multivariate statistics is feasible. Segregation of sample populations by process location improves model performance. Models using a reduced spectral range containing the most relevant spectral signatures show very similar performance to the full-range model, reinforcing the importance of performing robust exploratory data analysis before beginning multivariate modeling. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) adsorption and electron transport play an important role in CO2 reduction reaction (CO2RR). Herein, we have demonstrated a new class of diverse hollow ZnSnOx (ZSO) through the amorphization of hydroxides to enhance CO2 adsorption and accelerate electron transport. The amorphization is occurred by calcination process, as indicated by Fourier transform infrared spectroscopy and Raman spectra. In particular, the ZnSnOx hollow spheres (ZSO HSs) achieve a high Faradaic efficiency (FE) of HCOOH up to 92.7 % at best, outperforming the commercial ZSO (Comm. ZSO, 85.7 %). ZSO HSs also exhibit durable stability with negligible activity decay after 10 h of successive electrolysis. In‐situ attenuated total reflectance infrared absorption spectroscopy further reveals strong adsorption of CO2 and rapid intermediate configuration transformation in amorphous ZSO HSs. This work demonstrates the practical application of ZSO for CO2RR and provides a new insight to create efficient CO2RR electrocatalysts. [ABSTRACT FROM AUTHOR]

Understanding the phase transitions and structural dynamics of monomers is essential for designing advanced materials. In this study, the phase transitions of two phosphorus-containing monomers with methoxycarbonyl functional end groups were investigated. Polarized light optical microscopy, differential scanning calorimetry, and UV-vis absorption and fluorescence spectroscopy were used to examine microstructural changes and molecular conformational rearrangements during temperature variations. Additionally, attenuated total reflectance Fourier-transform infrared spectroscopy was used to explore these changes with high sensitivity. The specific sensitive absorption bands offered significant information regarding the phase transition, even within a narrow transition temperature range, demonstrating the efficiency of such a method in the investigation of polymorphic and liquid crystalline materials. Interestingly, although both molecules absorb light at similar wavelengths regardless of the solvent, their emission properties are different, suggesting that the presence of an extra oxygen atom linked to the central phosphorus atom influences the movement of electrons in the excited state. [ABSTRACT FROM AUTHOR]

[Display omitted] K-doped Mn–Ce solid solution catalysts were synthesized using a combination of coprecipitation and hydrothermal methods, demonstrating excellent performance in benzene oxidation. The catalyst K 1 Ce 5 Mn 5 exhibited comparable activity to noble metal catalysts, achieving a 90 % benzene conversion at approximately 194 ℃. Durable tests under dry and moist conditions revealed that the catalyst could maintain its activity for 50 h at 218 ℃ and 236 ℃, respectively. Characterization results indicated that the catalyst's enhanced activity resulted from the weakened Mn–O bonding caused by the introduction of K+, facilitating the activation of oxygen and its involvement in the reaction. CeO x , the main crystalline phase of Mn–Ce solid solutions, provided abundant oxygen vacancies for capturing and activating oxygen molecules for the weakened Mn–O structures. This conclusion was further supported by partial density of state analysis from density functional theory computations, revealing that the introduction of K+ weakened the orbital hybridization of Mn3d and O2p. Finally, in situ diffuse reflectance infrared Fourier-transform spectroscopy (in situ DRIFTS) studies on Ce 5 Mn 5 and K 1 Ce 5 Mn 5 catalysts suggested that the introduction of K+ promoted the conversion of adsorbed benzene. Furthermore, intermediate products were transformed more rapidly for K 1 Ce 5 Mn 5 compared to Ce 5 Mn 5. [ABSTRACT FROM AUTHOR]

Cheese quality is affected by seasonal variations. These variations can influence several aspects of cheese, including its flavor, texture, nutritional content, and overall sensory qualities. The aim of this study was to assess the performance of near-infrared (NIR) instrumentation in terms of its ability to detect seasonal variations in Halloumi cheese samples when applying limited sample preparation compared to traditional protocols. Therefore, the use of NIR spectroscopy was examined for the determination of seasonal variations in Halloumi cheese samples from Cyprus in combination with chemometrics. Partial Least Squares Discriminant Analysis (PLS-DA) was applied. We found that NIR and chemometrics successfully discriminated the Halloumi cheese samples based on different climate conditions, the four seasons in the year when the milk collection took place. To externally validate the model, the dataset was divided into training and test sets. The innovation of this study is that Halloumi cheese was studied regarding seasonal variations by applying NIR for the first time. The outcome of this preliminary study is positive in terms of the capability of NIR to distinguish seasonal variations in Halloumi cheese, especially those due to differences in fatty acid molecules throughout the year. Future studies will include more samples to increase the current database. [ABSTRACT FROM AUTHOR]

Epitaxial cubic (100) 3C-SiC films on a (100) silicon wafer were irradiated at room temperature with 2.3-MeV Si+ or 3.0-MeV Kr+ ions up to a fluence of 1 × 1016 cm−2. The evolutions of the epilayer and the substrate were followed as a function of ion fluence by using micro-Raman spectroscopy, optical absorption, and diffuse reflectance spectroscopy in the UV-visible and near infrared range. Raman spectra evidence the amorphization of SiC films at an estimated dose of about 0.1 displacement per atom (dpa) for both ion irradiations. The narrow peaks of the Raman-allowed TO and LO modes of SiC and Si are recorded in the virgin sample, together with few peaks assigned to zone-edge modes of SiC arising from the intrinsic disorder in the strained films. Those crystal phonon peaks broaden or disappear with increasing fluence. The spectra finally exhibit broad extra peaks assigned to the formation of Si–Si and C–C wrong homonuclear bonds in the local order of the amorphous phase. The optical transmission and diffuse reflectance spectra feature interference fringe patterns in the SiC film that are smoothened out with irradiation due to the matching of refractive indices of the amorphous SiC film and Si substrate. The evolution of the refractive index of SiC and optical gap of Si are deduced from those spectra. The respective roles of ballistic effects and electronic excitations in the radiation damage of both SiC and Si are discussed for those two ions with about the same electronic stopping power and about one order-of-magnitude difference in nuclear stopping power. The damage is dominated by the nuclear collision processes and rather well correlated with the estimated irradiation dose in dpa. Optical spectra show that electronic excitations induce damage recovery of the amorphized substrate below the SiC/Si interface. Raman spectra and optical absorption/reflection spectra yield complementary pictures of the radiation damage. [ABSTRACT FROM AUTHOR]

• Both Vis-NIR and PXRF sensors were used to estimate soil Cd concentrations. • Predicted results by fused datasets outperformed those by any single datasets. • PXRF performed better than Vis-NIR in estimating soil Cd concentrations. • Iron was the main bridge for the spectral estimation of soil Cd. Conventionally, soil cadmium (Cd) measurements in the laboratory are expensive and time-consuming, involving complex processes of sample preparation and chemical analysis. This study aimed to identify the feasibility of using sensor data of visible near-infrared reflectance (Vis-NIR) spectroscopy and portable X-ray fluorescence spectrometry (PXRF) to estimate regional soil Cd concentration in a time- and cost-saving manner. The sensor data of Vis-NIR and PXRF, and Cd concentrations of 128 surface soils from Yunnan Province, China, were measured. Outer-product analysis (OPA) was used for synthesizing the sensor data and Granger-Ramanathan averaging (GRA) was applied to fuse the model results. Artificial neural network (ANN) models were built using Vis-NIR data, PXRF data, and OPA data, respectively. Results showed that: (1) ANN model based on PXRF data performed better than that based on Vis-NIR data for soil Cd estimation; (2) Fusion methods of both OPA and GRA had higher predictive power (R 2) = 0.89, ratios of performance to interquartile range (RPIQ) = 4.14, and lower root mean squared error (RMSE) = 0.06, in ANN model based on OPA fusion; R 2 = 0.88, RMSE = 0.06, and RPIQ = 3.53 in GRA model) than those based on either Vis-NIR data or PXRF data. In conclusion, there exists a great potential for the combination of OPA fusion and ANN to estimate soil Cd concentration rapidly and accurately. [Display omitted] [ABSTRACT FROM AUTHOR]

BACKGROUND: Little information is available on α‐ and β‐amylase activity and their associations with starch, sugars and other culinary qualities in sweetpotato. The present study aimed to assess sweetpotato storage root α‐ and β‐amylase activity in relation to starch, sugars, β‐carotene content and storage root flesh color. RESULTS: α‐ and β‐amylase activity (α‐AA and β‐AA) were assayed from a Tanzania (T) × Beauregard (B) genetic mapping population in their uncured (raw), cured and stored (approximately 11 weeks) forms during 2016 and 2017. Ceralpha and Betamyl methods, with modifications to suit a high‐throughput microplate assay format, were used to quantify α‐AA and β‐AA, respectively. Storage root dry matter, starch, glucose, fructose, sucrose and β‐carotene content were predicted using near infrared reflectance spectroscopy. There was little relationship (r2 = 0.02–0.08, P ≤ 0.05 in 2016 and r2 = 0.05–0.11, P ≤ 0.05 in 2017) between α‐AA and β‐AA. We observed negative linear associations between α‐AA and dry matter content and generally no correlations between β‐AA and dry matter content. β‐AA and sugars were weakly positively correlated. β‐AA and β‐carotene content were positively correlated (r = 0.3–0.4 in 2016 and 0.3–0.5 in 2017). CONCLUSION: Generally, the correlation coefficient for amylase enzyme activity and sugar components of storage roots at harvest increased after curing and during post‐harvest storage. The present study is a major step forward in sweetpotato breeding in terms of providing a better understanding of how α‐ and β‐amylase activity are inter‐associated with several culinary quality attributes. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Goethite and ferrihydrite are the two major iron hydroxides, essential mineral constituents in the terrestrial surface system. Aluminum (Al) is the most common substituent in iron hydroxides, and it may significantly change the bulk and surficial physicochemical properties of iron hydroxides. Consequently, a practical and convenient approach is needed to efficiently identify the Al substitution degrees of iron hydroxides in natural occurrences. This study presents a comprehensive investigation of the VSWIR characteristics of laboratory-synthesized Al-substituted goethite and ferrihydrite, to establish diagnostic VSWIR parameters for the identification and quantification of Al substitution levels in iron hydroxides. The findings revealed that Al substitution can affect the band positions (P) of goethite and ferrihydrite at ~650 nm, ~900 nm, and ~1400 nm. The relationships between the Al substitution of ferrihydrite and VSWIR parameters can be expressed as P900 = −0.43 × Al(%) + 931 and P1400 = −0.07 × Al(%) + 1428, while that of goethite can be expressed as P650 = 0.42 × Al(%) + 657 and P900 = 2.29 × Al(%) + 936. The peak fitting results showed that the absorption intensity at 480–550 nm linearly decreases with increased Al substitution. The obtained VSWIR spectra of Al-substituted goethite and ferrihydrite provide a critical supplement to the spectral library for (Al) iron hydroxides, and these VSWIR parameters can be utilized for the semi-quantitative determination of Al substitution in natural iron hydroxides [ABSTRACT FROM AUTHOR]

Dendrobium officinale (D. officinale), often used as a dual-use plant with herbal medicine and food applications, has attracted considerable attention for health-benefiting components and wide economic value. The antioxidant ability of D. officinale is of great significance to ensure its health care value and safeguard consumers' interests. However, the common analytical methods for evaluating the antioxidant ability of D. officinale are time-consuming, laborious, and costly. In this study, near-infrared (NIR) spectroscopy and chemometrics were employed to establish a rapid and accurate method for the determination of 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, and ferric reducing antioxidant power (FRAP) in D. officinale. The quantitative models were developed based on the partial least squares (PLS) algorithm. Two wavelength selection methods, namely the genetic algorithm (GA) and competitive adaptive reweighted sampling (CARS) method, were used for model optimization. The CARS-PLS models exhibited superior predictive performance compared to other PLS models. The root mean square errors of cross-validation (RMSECVs) for ABTS, FRAP, and DPPH were 0.44%, 2.64 μmol/L, and 2.06%, respectively. The results demonstrated the potential application of NIR spectroscopy combined with the CARS-PLS model for the rapid prediction of antioxidant activity in D. officinale. This method can serve as an alternative to conventional analytical methods for efficiently quantifying the antioxidant properties in D. officinale. [ABSTRACT FROM AUTHOR]

Layered double hydroxide (LDH) nanostructures are commonly used to study the interfacial effects of Pt‐based catalysts in CO oxidation. However, the specific role and detailed intermediates involved in CO oxidation remain unclear. Density functional theory (DFT) predicted that NiFe LDH loaded with single Pt atoms would exhibit satisfactory CO oxidation activity. On this basis, we prepared Pt1NiFe LDH catalysts with various Fe : Ni ratios by using the one‐pot method and achieved favorable dispersion of single Pt atoms. Pt1/FN‐1, which had the optimal Fe : Ni ratio (1 : 1), exhibited satisfactory catalytic performance for CO oxidation and a high turnover frequency, as determined through DFT calculations and experimental characterization. In‐situ diffuse reflectance infrared Fourier transform spectroscopy confirmed that CO directly reacted with Pt1/FN‐1 to produce CO2 and that introduced O2 formed bicarbonate species to produce CO2 together with the adsorbed CO on Pt1 sites. Overall, our work provides new insights into the catalytic mechanism of the well‐known Pt1NiFe LDH catalysts in CO oxidation. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Chemical Communications" published in 2024. It includes articles on various topics such as catalytic dehydrogenative coupling, superoxide dismutase nanozymes, hydrogen production from alcohols, and ion transport in solid-state batteries. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document provides a glimpse into the research articles featured in the journal, making it a valuable resource for library patrons conducting research in the field of chemistry. [Extracted from the article]

We introduce an innovative in situ infrared diffuse reflection rapid detection system, endowed with a temperature regulation function. This system is adept at conducting rapid infrared spectra scanning as well as simulating the catalytic environment of diverse reaction systems. The infrared absorption spectra of four kinds of Pt-based catalysts under vacuum conditions across a wide temperature spectrum ranging from −180 to 300 °C are obtained and analysed through IR correlation spectroscopy. A key finding is the notable variance in peak intensity within Pt/CeO2/CNT catalysts, highlighting a robust adsorption capacity for oxygen-containing groups at lower temperatures and a marked desorption at higher temperatures. By enabling rapid and accurate assessments of catalyst behavior under varying temperatures, it not only accelerates the evaluation process but also provides valuable insights that can guide the synthesis of more efficient catalysts. [ABSTRACT FROM AUTHOR]

In this work, the phosphomolybdate (HPMo) modification strategy was applied to improve the N 2 selectivity of MnCo-BTC@SiO 2 catalyst for the selective catalytic reduction of NO x , and further, the mechanism of HPMo modification on enhanced catalytic performance was explored. Among MnCo-BTC@SiO 2 -x catalysts with different HPMo concentrations, MnCo-BTC@SiO 2 -0.75 catalyst exhibited not only the highest NH 3 -SCR performance (∼95% at 200-300°C) but also the best N 2 selectivity (exceed 80% at 100-300°C) due to the appropriate redox capacity, greater surface acidity. X-ray photoelectron spectrometer (XPS) and temperature programmed reduction of H 2 (H 2 -TPR) results showed that the modification with HPMo reduced the oxidation-reduction performance of the catalyst due to electron transfer from Mo5+ to Mn4+/Mn3+ and prevent the excessive oxidation of ammonia adsorption species. NH 3 temperature-programmed desorption of (NH 3 -TPD) results showed that the modification with HPMo could significantly improve the surface acidity and NH 3 adsorption, which enhance the catalytic activity and N 2 selectivity. In-situ diffused reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) revealed that modification with HPMo increased significantly the amount of adsorbed NH 3 species on the Bronsted acid site and C B / C L , it suppressed the production of N 2 O by inhibiting the production of NH species, the deep dehydrogenation of ammonia adsorption species. This study provided a simple design strategy for the catalyst to improve the low-temperature catalytic performance and N 2 selectivity. [Display omitted] [ABSTRACT FROM AUTHOR]

Diffuse reflectance spectroscopy is emerging as a reliable soil testing approach. However, few studies reported on the applicability of DRS for estimating the overall soil quality index (SQI) in smallholder farms. Specifically, the DRS approach has not been evaluated in cocoa production systems with multi‐year soil data. We evaluated the DRS approach in typical cocoa production systems from Papua New Guinea (PNG) by collecting soil samples before and after implementing soil test‐based nutrient recommendations. Specifically, 379 soil samples were collected in 2017 from cocoa farms in East New Britain, New Ireland, and Bouganville provinces of PNG. A second soil testing campaign was undertaken in 2019 to analyse 432 soil samples from the same farms to test the consistency of the DRS approach for SQI assessment. In all these samples, 15 soil parameters were measured using the conventional wet chemistry approach. Reflectance spectra in each sample were also measured over the visible to near‐infrared (wavelength: 350–2500 nm). A minimum dataset approach was followed to estimate SQIs from laboratory‐measured soil properties. With available N, clay content, available P, and available Zn adjudged as significant soil quality parameters for the cocoa plantations of PNG, estimated mean SQI values ranged from 0.30 in the cocoa farm from Bouganville province (BOKA‐PAN) in 2017 to 0.46 for the New Ireland province (LAU‐PAN) soil samples collected during 2019. Overall, SQI values increased from about 13%–21% following the nutrient applications. Based on the validation of two commonly‐used chemometric models (PLSRFS: partial‐least‐squares regression with feature selection, SVR: support vector regression), the SQI values were estimated with the coefficient of determination (R2) values as high as.94. Our results showed that a DRS model calibrated in soil samples collected in a specific year can be used for estimating SQI values in soil samples collected in different years. These results suggest that the principal component analysis (PCA) based SQI may be estimated from the DRS data with good accuracy and SQI values may potentially capture the management effects in smallholder farms. [ABSTRACT FROM AUTHOR]

Studies documenting the consequences of harvest traffic in alfalfa production have addressed soil and plant growth parameters. One response was larger leaf/stem ratios in plants that were trafficked, which suggests higher quality. To fully understand how harvest traffic affects alfalfa quality a need for further analysis is warranted. Our objectives were to quantify differences in plant quality between trafficked and non-trafficked plants through 4 years of alfalfa production and to determine when these differences occur. The experimental units were furrow-irrigated raised beds with four harvests per year in Youngston clay loam soil in Fruita, Colorado. A John Deere 2280 swather and a John Deere 2955 tractor, driven over the alfalfa 7 days after swathing, were used to create four traffic treatments; plants that were never trafficked, plants trafficked only by the swather, plants trafficked only by the tractor, and plants trafficked by both the swather and the tractor. Quality was determined by measuring relative feed value, acid detergent fiber, neutral detergent fiber, and crude protein using near infrared reflectance spectroscopy. Alfalfa trafficked by the tractor had increased quality throughout the 4 years of production. [ABSTRACT FROM AUTHOR]

To develop nontoxic and stable fluorescent emission B-Cu nanoclusters (NCs) for the specific detection of dopamine at low concentrations in cerebrospinal fluid (CSF). Fluorescent gold and copper NCs conjugated with proteins, such as bovine serum albumin (BSA), offer photostability and healthcare potential. This study focused on fabricating B-Cu NCs that exhibited superior characteristics for sensitive dopamine detection. The study employed various instrumental techniques including attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), spectrofluorometry, and transmission electron microscopy (TEM) to characterize the formulated B-Cu NCs. The NCs were synthesized, resulting in particle size ∼300 nm. The highest observed fluorescence was recorded at 24542.81 relative fluorescence units (RFU). The introduction of dopamine at concentrations of 0.1, 0.2, 0.3, and 0.4 ng/mL led to decreased fluorescence in both B-Au and B-Cu NCs due to an electron transport system. This reduction in fluorescence allowed dopamine concentration analysis in phosphate buffer and biological fluids such as blood plasma and CSF. B-Cu NCs showed potential as a biosensing system for point-of-care (POC) applications, specifically for diagnosing schizophrenia. The study successfully synthesized stable and nontoxic B-Cu NCs with enhanced fluorescent emission properties. These NCs exhibited the capacity to detect dopamine at low concentrations in CSF. The study's findings hold promise for future applications, particularly in the development of a B-Cu NCs-based biosensing system for convenient POC detection of schizophrenia by both patients and clinicians. The potential impact of this technology on healthcare and biomedical fields is substantial. [ABSTRACT FROM AUTHOR]

Lignin-poly(ethylene)glycol diglycidyl ether hydrogels were synthesized from lignin fractions readily extracted during the hot-water treatment of angiosperms: hardwoods, sugar maple and energy-crop willow, monocotyledons, grasses, miscanthus and agriculture residues, and wheat straw. These lignins represent a broad range of chemical structures and properties as a comparative analysis of their suitability to produce the hydrogels as a novel carrier of chaga–silver nanoparticles. The formation of hydrogels was assessed via attenuated total reflectance Fourier-transformed infrared spectroscopy. Then, the hydrogels were observed via scanning electron microscopy and evaluated for their free-absorbency capacity and moduli of compression. Furthermore, a hydrogel produced from kraft lignin and two commercial hydrogels was evaluated to benchmark the effectiveness of our hydrogels. Chaga extracts were prepared via the hot-water extraction of chaga mushroom, a method selected for its relatively higher yields and preserved antioxidizing activities. Hydrogels synthesized with lignins of monocotyledons, wheat straw, and miscanthus were found to be suitable carriers for chaga–silver nanoparticles due to their favorable absorption and release behaviors. [ABSTRACT FROM AUTHOR]

The synthesis process of conventional Mn-based denitrification catalysts is relatively complex and expensive. In this paper, a resource application of chlorella was proposed, and a Chlorella@Mn composite denitrification catalyst was innovatively synthesized by electrostatic interaction. The Chlorella@Mn composite denitrification catalyst prepared under the optimal conditions (0.54 g/L Mn2+ concentration, 20 million chlorellas/mL concentration, 450°C calcination temperature) exhibited a well-developed pore structure and large specific surface area (122 m2/g). Compared with MnOx alone, the Chlorella@Mn composite catalyst achieved superior performance, with ∼100% NH 3 selective catalytic reduction (NH 3 -SCR) denitrification activity at 100-225°C. The results of NH 3 temperature-programmed desorption (NH 3 -TPD) and H 2 temperature-programmed reduction (H 2 -TPR) showed that the catalyst had strong acid sites and good redox properties. Zeta potential testing showed that the electronegativity of the chlorella cell surface could be used to enrich with Mn2+. X-ray photoelectron spectroscopy (XPS) confirmed that Chlorella@Mn had a high content of Mn3+ and surface chemisorbed oxygen. In-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) experimental results showed that both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms play a role in the denitrification process on the surface of the Chlorella@Mn catalyst, where the main intermediate nitrate species is monodentate nitrite. The presence of SO 2 promoted the generation and strengthening of Brønsted acid sites, but also generated more sulfate species on the surface, thereby reducing the denitrification activity of the Chlorella@Mn catalyst. The Chlorella@Mn composite catalyst had the characteristics of short preparation time, simple process and low cost, making it promising for industrial application. [Display omitted] Schematic diagram of NH 3 -SCR performance of Chlorella@Mn composite denitrification catalyst. [ABSTRACT FROM AUTHOR]

A facile method for the immobilization of β-cyclodextrin on polysulfone membranes with the aim of selectively adsorbing low-density lipoprotein (LDL) was established, which is based on the self-assembly of dopamine on the membrane followed by the Schiff base reaction with mono-(6-ethanediamine-6-deoxy)-β-cyclodextrin. The surface modification processes were validated using X-ray photoelectron spectroscopy and attenuated total reflectance Fourier-transform infrared spectroscopy. Surface wettability and surface charge of the membranes were investigated through the water contact angle and zeta potential analysis. The cyclodextrin-modified polysulfone membrane (PSF-CD) showed good resistance to protein solutions, as shown by the measurement of BSA adsorption. The assessment of BSA adsorption revealed that the cyclodextrin-modified polysulfone membrane (PSF-CD) exhibited excellent resistance to protein solutions. To investigate the adsorption and desorption behaviors of the membranes in single-protein or binary-protein solutions, an enzyme-linked immunosorbent assay was employed. The results revealed that the PSF-CD possessed remarkable adsorption capacity and higher affinity for LDL in both single-protein and binary-protein solutions, rendering it a suitable material for LDL apheresis. [ABSTRACT FROM AUTHOR]

In the field of petrochemistry, the quantitative determination of trace elements in catalysts is crucial for optimizing various types of processes. Catalyst poisoning, resulting from the presence of contaminants, can lead to decreased performance and efficiency, even when these are present at trace level only. Inductively coupled plasma-mass spectrometry (ICP-MS) is a powerful technique for trace elemental analysis, but its application to catalysts is challenging due to their physicochemical characteristics challenging straightforward dissolution. Laser ablation (LA) coupled to ICP-MS (LA-ICP-MS) has emerged as a valuable approach for direct analysis of solid samples. However, developing an appropriate calibration strategy for reliable quantitative LA-ICP-MS analysis of catalyst samples remains a challenge. In this work, different calibration strategies for quantitative LA-ICP-MS analysis of fused catalyst samples were evaluated. The traditional strategy relied on external calibration against certified reference materials (CRMs) combined with internal standardization and was considered the reference approach. When using this approach, the relative bias with respect to the reference value was found to be <15%. Two novel calibration strategies were introduced and compared: a so-called multi-signal calibration approach and a solution-based calibration approach. The multi-signal calibration strategy involved varying the laser repetition rate (20, 30, 40 and 50 Hz) or laser beam diameter (10, 12, 15 and 20 μm), allowing a calibration curve to be constructed by comparing the analytical signal intensity for a single solid CRM with that for the sample, thus partially overcoming the shortage of CRMs for quantitative LA-ICP-MS analysis. The solution-based calibration approach was used for quantitative multi-element analysis without the need for any solid standard and required only minor hardware modifications to accommodate the introduction of aqueous standard solutions for calibration. Various glass certified reference materials were used for method development, calibration, and validation purposes. Furthermore, two fused alumina catalyst samples (used in the context of petroleum refining processes) were successfully analyzed as a proof-of-concept application. For both the multi-signal (matrix-matched conditions) and the solution-based calibration approaches, the average relative bias between the experimentally determined and certified/reference concentrations varied between −9% and +7%. [ABSTRACT FROM AUTHOR]

Chlorhexidine dodecyl sulfate (CHX-DS) was synthesized and characterized via single-crystal X-ray diffraction (SC-XRD), 1H nuclear magnetic resonance (NMR) spectroscopy, 1H nuclear Overhauser effect spectroscopy (NOESY), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The solid-state structure, comprising a 1 : 2 stoichiometric ratio of chlorhexidine cations [C22H30Cl2N10]2+ to dodecyl sulfate anions [C12H25SO4]−, is the first report of chlorhexidine isolated with a surfactant. CHX-DS exhibits broad-spectrum antibacterial activity and demonstrates superior efficacy for reducing bacteria-generated volatile sulfur compounds (VSCs) as compared to chlorhexidine gluconate (CHG). The minimum inhibitory concentrations (MICs) of CHX-DS were 7.5, 2.5, 2.5, and 10 μM for S. enterica, E. coli, S. aureus, and S. mutans, respectively. Furthermore, MIC assays for E. coli and S. mutans demonstrate that CHX-DS and CHX exhibit a statistically significant efficacy enhancement in 2.5 μM treatment as compared to CHG. CHX-DS was incorporated into SBA-15, a mesoporous silica nanoparticle (MSN) framework, and its release was qualitatively measured via UV-vis in aqueous media, which suggests its potential as an advanced functional material for drug delivery applications. [ABSTRACT FROM AUTHOR]

Gem-quality blue octahedral crystalline gahnite was produced in Nigeria. This paper investigated gemological and spectroscopic characteristics by basic gemological experiments, electron probes, infrared reflectance spectroscopy, laser Raman spectroscopy, photoluminescence spectroscopy, and ultraviolet-visible spectroscopy. The results show that the refractive index (RI) of Nigerian gahnite is 1.792∼1.794, and the specific gravity is 4.45∼4.66, with no fluorescence. The main chemical composition is ZnAl2O4, accounting for 93.57%, and the rest is mainly FeAl2O4, which also contains Na, Mg, Co, Mn, Cr, Cu, Si, K, and Ca elements. The infrared spectra showed midinfrared absorption bands near 510 cm−1, 559 cm−1, and 664 cm−1 in the fingerprint region, corresponding to the Zn-O stretching vibration, bending vibration, and Al-O bending vibration, respectively. The Raman spectra showed three of the five Raman active modes of the spinel group, with characteristic Raman absorption peaks located at 418 cm−1, 508 cm−1, and 660 cm−1, corresponding to Eg, T2g(2), and T2g(3) modes, respectively, and the comparison revealed a higher degree of Zn and Al ordering in this paper for gahnite. The photoluminescence spectra show the common Cr3+-activated fluorescence splitting peaks of natural spinel, of which the 686 nm (R-line) fluorescence peak is obvious and sharp. The UV-vis absorption spectra located at 444 nm and 489 nm are the most obvious, which are caused by the d-d electron leap of TFe2+ (5E ⟶ 5T2), and the blue-gray tones of the samples are mainly caused by the spin-forbidden electronic transitions in TFe2+ and MFe2+ ↔ MFe3+; the weak absorption peak at 609 nm was determined to be associated with Co2+ by derivative spectra. [ABSTRACT FROM AUTHOR]

Understanding the composition, texture, and morphology of volcanic rocks that have erupted at the surface better constrains the eruption style and is vital to infer subsurface processes, the development of magma upon ascent, and the potential for future eruptions. The reflectance and emission spectroscopy of these rocks, collected from the near-infrared (NIR) through the thermal infrared (TIR) portion of the electromagnetic (EM) spectrum, provides the data necessary to retrieve composition, micron-scale surface roughness, and particle size. Remote imaging systems enable the analyses of active volcanoes in remote regions, where sample collection for laboratory analysis poses a significant challenge. Laboratory hyperspectral data of samples acquired at volcanic deposits are easily resampled to the spectral resolution of any infrared sensor and provide a means of estimating the composition of volcanoes and their products worldwide, as well as those on other planetary bodies such as the Moon and Mars. In this review paper, we provide an overview of the current use of infrared reflectance and emission spectroscopy as an analysis tool in volcanology, including ground-based imaging systems that acquire unprecedented detail and serve as testbeds for new orbital concepts. We also discuss the potential impact that future satellite missions will have on volcano science as spectral, spatial, and temporal resolutions improve. [ABSTRACT FROM AUTHOR]

The development of convective technologies for antibody purification is of interest to the bioprocessing industries. This study developed a Protein A membrane using a combination of graft polymerization and copper(I)-catalyzed alkyne–azide click chemistry. Regenerated cellulose supports were functionalized via surface-initiated copolymerization of propargyl methacrylate (PgMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA300), followed by a reaction with azide-functionalized Protein A ligand. The polymer-modified membranes were characterized using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), gravimetric analysis, and permeability measurements. Copolymer composition was determined using the Mayo–Lewis equation. Membranes clicked with azide-conjugated Protein A were evaluated by measuring static and dynamic binding (DBC10) capacities for human immunoglobulin G (hIgG). Copolymer composition and degree of grafting were found to affect maximum static binding capacities, with values ranging from 5 to 16 mg/mL. DBC10 values did not vary with flow rate, as expected of membrane adsorbers. [ABSTRACT FROM AUTHOR]

Both cyclodextrin (CD) and porous silica possess interesting properties of adsorption and release. A silica–CD hybrid, therefore, could synergically merge the properties of the two components, giving rise to a material with appealing properties for both environmental and pharmaceutical applications. With this aim, in the present study, a first hybrid is obtained through one-pot sol–gel synthesis starting from CD and tetramethyl orthosilicate (TMOS) as a silica precursor. In particular, methyl-β-cyclodextrin (bMCD) is selected for this purpose. The obtained bMCD–silica hybrid is a dense material containing a considerable amount of bMCD (45 wt.%) in amorphous form and therefore represents a promising support. However, since a high specific surface area is desirable to increase the release/adsorption properties, an attempt is made to produce the hybrid material in the form of an aerogel. Both the synthesis of the gel and its drying in supercritical CO2 are optimized in order to reach this goal. All the obtained samples are characterized in terms of their physico-chemical properties (infra-red spectroscopy, thermogravimetry) and structure (X-ray diffraction, electron microscopy) in order to investigate their composition and the interaction between the organic component (bMCD) and the inorganic one (silica). [ABSTRACT FROM AUTHOR]

Reflectance spectroscopy is a rapid and non-destructive technique for probing the chemical composition of the earth surface. The minerals are characterised by absorption features whose wavelength is function of its crystal chemistry. In the present study, we propose a covariance weighted least square inversion approach to model the wavelength position of the absorption features. The approach takes into consideration the noise in the reflectance spectra and estimates the wavelength position with root mean square value of less than 5 nm for library spectra. The algorithm is then implemented on AVIRIS-NG datasets of Hutti-Maski schist belt to map the spatial variations in wavelength position of absorption features in wavelength range 2290–2360 nm. Sensitivity of model parameters to number of points, effect of number of data points on striping noise and limitations of the proposed algorithm are also discussed. It is observed that the algorithm based wavelength map is smooth and enables identification of gradients in absorption wavelength position. Mapping of such gradients are very important for understanding subtle changes in crystal chemistry due to hydrothermal alteration and possible mineralization. The generated wavelength map can be used in conjunction with alteration mineral assemblage to identify prospective zones for mineral exploration. [ABSTRACT FROM AUTHOR]

[Display omitted] A high surface area (883 m2·g−1) nanocomposite composed of an amine-functionalized metal–organic framework (NH 2 -UiO-66 (U6N)) and manganese dioxide (MnO 2 @U6N) was prepared as bifunctional adsorbent-catalyst for the purification of multiple aromatic volatile organic compounds (VOCs) such as benzene (B), toluene (T), m-xylene (X), and styrene (S), i.e., BTXS. The performance of MnO 2 @U6N was assessed for BTXS removal both as single- and multi-component systems at room temperature (RT (20 °C)) under dark conditions. MnO 2 @U6N exhibited superior catalytic-adsorption activity for the RT removal of BTXS. The removal performance of MnO 2 @U6N against BTXS was then assessed across varying levels of flow rate, VOC concentration, adsorbent/catalyst mass, and relative humidity. To better understand the catalytic-adsorption activity, two types of non-linear kinetic models (pseudo-first-order and pseudo-second-order) were utilized to simulate the experimentally obtained data. In-situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) analysis was also conducted to interpret the removal mechanism of BTXS. Their adsorption capacity (mg·g−1) values are estimated to increase in the order of B (21.1) < T (66.0) < X (79.1) < S (129.7). It is suggested that the adsorbed aromatic VOC molecules on the surface of MnO 2 @U6N should react with active oxygen species (lattice and adsorbed oxygen) to yield the environmentally benigh end products (i.e., carbon dioxide and water) along with various intermediates (e.g., alkoxides, aldehydes, phenolates, carboxylates, and anhydrides). Accordingly, the VOC removal potential of MnO 2 @U6N has been validated through the synergistic combination between adsorption (primary process) and catalysis (subordinate process) at RT. [ABSTRACT FROM AUTHOR]

This study demonstrates the significant impact of gallium ions on the local structure and physical, optical, and biological properties of borosilicate glasses. The glass composition, denoted as BSCZG, with the formula (50B2O3–5SiO2–15ZnO–(30-x)CaO–xGa2O3), where 0 ≤ x ≤ 20 mol%, was synthesized using the melt quenching technique. X-ray diffraction (XRD) patterns confirmed the amorphous nature of the BSCZG samples, presenting a broad hump. Analysis of the attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) results revealed the transformation of BO4 units into BO3 units, accompanied by generating non-bridging oxygens (NBOs) with increasing Ga2O3 content. As Ga2O3 content increased from 0 to 20 mol%, the experimental density (ρexp) and molar volume (Vm) of BSCZG glasses also increased, shifting from 2.70 to 3.14 g cm−3 and from 24.66 to 29.58 cm3 mol−1, respectively were also observed. This increment in Vm can be attributed to the rise in NBOs. Furthermore, an inverse relationship was observed between the optical band gap (Eopt) and optical band tail energy (EU); Eopt decreased from 3.27 to 3.08 eV, while EU increased from 0.20 to 0.25 eV with the Ga2O3 content rising from 0 to 20 mol%. The refractive index (n) of BSCZG glasses also increased from 1.52 to 1.57 as Ga2O3 content increased. Additionally, XRD patterns and ATR-FTIR spectra of BSCZG confirmed the formation of hydroxyapatite (HA) following assessment in simulated body fluid (SBF) for 3, 7, and 14 days. Protein adsorption in phosphate-buffered saline (PBS), cell viability (MTT) assays using Vero cells, and immersion in SBF were conducted to assess the bioactivity of the prepared samples. The results indicated that gallium ions containing borosilicate glasses exhibited significantly higher degradation rates than the Ga-free glass sample. Despite increased chemical durability, the substituted glasses displayed a favorable in vitro bioactive response. SBF results suggested that BSCZG glasses were more likely to contain higher concentrations of HA due to the elevated content of Ga ions. In conclusion, borosilicate glasses incorporating Ga3+ ions demonstrate promising effects for both optical and biomedical applications. [ABSTRACT FROM AUTHOR]

Background Dendrobium huoshanense (DHS) is a classic traditional Chinese medicine (TCM) with distinctive medicinal benefits and great economic worth; nevertheless, because of similar tastes and looks, it is simple to adulterate with less expensive substitutes (such as Dendrobium henanense [ DHN ]). Objective This work aimed to develop a reliable tool to detect and quantify the adulteration of DHS with DHN by using UV-Vis-shortwave near-infrared diffuse reflectance spectroscopy (UV-Vis-SWNIR DRS) combined with chemometrics. Methods Adulterated samples prepared in varying concentrations (0–100%, w/w) were analyzed with UV-Vis-SWNIR DRS methods. Partial least-square-discriminant analysis (PLS-DA) and partial least-squares (PLS) regression techniques were used for the differentiation of adulterated DHN from pure DHS and the prediction of adulteration levels. Results The PLS-DA classification models successfully differentiated adulterated and nonadulterated DHS with an over 100% correct classification rate. UV-Vis-SWNIR DRS data were also successfully used to predict adulteration levels with a high coefficient of determination for calibration (0.9924) and prediction (0.9906) models and low error values for calibration (3.863%) and prediction (5.067%). Conclusion UV-Vis-SWNIR DRS, as a fast and environmentally friendly tool, has great potential for both the identification and quantification of adulteration practices involving herbal medicines and foods. Highlights UV-Vis-SWNIR DRS combined with chemometrics can be applied to identify and quantify the adulteration of herbal medicines and foods. [ABSTRACT FROM AUTHOR]

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The underlying mechanisms and biochemical actions responsible for inactivation of pathogenic gram-positive Staphylococcus aureus (S. aureus) and gram-negative Salmonella abony (S. abony) bacteria upon exposure to sub-atmospheric plasma has been investigated. Reduction in colony forming units of the bacteria is established in 60 min and 40 min for S. aureus and S. abony respectively via 6-log reduction curves. The percentage change in reactive oxygen species, such as •OH and H2O2 formed on bacterial membrane during plasma exposure are analysed using spectroflurometer. S. aureus exhibited a significant increase of 324.23% and 1554.84% in •OH and H2O2 radicals respectively. Whereas, 98.14% and 54.49% increase in •OH and H2O2 radicals respectively was observed in S. abony. The oxidation and degradation of DNA is analysed using an ultra violet visible spectrophotometer. The leakage of proteins, lipids, and nucleic acid molecules due to plasma exposure is studied by Attenuated Total Reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The alteration of secondary protein structure on the cell membrane is observed using Circular Dichroism. Upon exposure to plasma, S. aureus shows a secondary protein structural transition from α-helix (2.4%), β-sheet (78.3%) mixture to modified β-sheet structure (0% α-helix, 79.1% β-sheet). Whereas, S.abony shows a transition from α-helix (1%), β-sheet (64.9%) mixture to modified β-sheet structure (0% α-helix, 74.5% β-sheet). The bacterial morphological study (swelling/shrinking) done using Field Emission Scanning Electron Microscopy (FE-SEM) reveals the deformation of cell membrane. Above findings pave the way for a better understanding of the processes of antimicrobial inactivation strategies when the plasma sterilization process is employed. [ABSTRACT FROM AUTHOR]

The water molecule occurs in two nuclear-spin isomers that differ by the value of the total nuclear spin of the hydrogen atoms, i.e., I = 0 for para-H2O and I = 1 for ortho-H2O. Spectroscopic transitions between rovibrational states of ortho and para water are extremely weak due to the tiny hyperfine nuclear-spin–rotation interaction of only ∼30 kHz and, so far, have not been observed. We report the first comprehensive theoretical investigation of the hyperfine effects and ortho–para transitions in H 2 16 O due to nuclear-spin–rotation and spin–spin interactions. We also present the details of our newly developed general variational approach to the simulation of hyperfine effects in polyatomic molecules. Our results for water suggest that the strongest ortho–para transitions with room-temperature intensities on the order of 10−31 cm/molecule are about an order of magnitude larger than previously predicted values and should be detectable in the mid-infrared ν2 and near-infrared 2ν1 + ν2 and ν1 + ν2 + ν3 bands by current spectroscopy experiments. [ABSTRACT FROM AUTHOR]

MgSnN2 with an average wurtzite structure (wz-MgSnN2) has recently emerged as a pseudo-III-nitride semiconductor, studied for applications in tandem solar cells, green light-emitting diodes, and other optoelectronic devices. This compound has only been researched recently, and, therefore, its charge-carrier transport properties are poorly understood. Understanding these properties is essential for optoelectronic applications. In this study, we grew wz-Mg1−xSn1+xN2 biaxially oriented polycrystalline films with x = −0.08 to 0.29 by reactive sputtering and investigated the charge-carrier transport properties using both direct current and optical techniques. We regarded the wz-Mg1−xSn1+xN2 films as magnesium tin oxynitride films (wz-MTNO) because a certain amount of oxygen was unintentionally incorporated into the sputtered wz-Mg1−xSn1+xN2 films. The wz-MTNO layers were n-type degenerate semiconductors with an electron density (ne) of the order of 1020 cm−3. In films with ne > 8 × 1020 cm−3, optically extracted resistivities (ρopt) obtained via a Drude-fit analysis of the infrared transmittance and reflectance spectra were almost identical to the direct-current resistivities (ρdc), indicating that the contribution of grain boundary scattering to the electron transport was negligible. However, the contribution of grain boundary scattering became unignorable with decreasing ne. The Drude-fit analysis also allowed the determination of the conduction-band effective mass (mc*) for the first time. A band edge mass of mc*/m0 ≈ 0.2 (m0 denotes the free-electron mass) was obtained in the wz-MTNO layers with |x| < 0.1. As x was increased from −0.18 to 0.29, mc*/m0 substantially increased from 0.18 to 0.56, indicating that the conduction-band dispersion decreased. That is, the conduction-band dispersion may be affected by the cation composition x. The findings of this study will provide important information to establish this material as a practical nitride semiconductor. [ABSTRACT FROM AUTHOR]

Blends of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) are biodegradable polymers with opposite, yet complementary, physical and thermal properties. However, PLA and PBAT are immiscible and additives must be introduced to overcome their incompatibility and achieve their full potential as blended polymers. In this work, we describe the use of epoxidized canola oil (ECO) as a novel compatibilizer for PLA and PBAT. ECO was produced and characterized using Attenuated Total Reflectance Fourier-Transform Infrared spectroscopy (ATR-FTIR) and proton nuclear magnetic resonance (1H NMR). ATR-FTIR confirmed the epoxidation reaction, while 1H NMR was used to quantify the alkene-to-epoxy conversion rate. Polymer blends were prepared using a batch mixer and were characterized using ATR-FTIR, 1H NMR, scanning electron microscopy, differential scanning calorimetry, and mechanical analyses. The polymer blends containing ECO demonstrated a significant reduction in the PBAT dispersed phase size and thermal transitions of PLA (glass transition, cold crystallization, and melt temperatures), as well as a significant increase in elongation-at-break while maintaining the same tensile strength and Young's Modulus. [ABSTRACT FROM AUTHOR]

In order to rapidly and accurately monitor cadmium contamination in lettuce and understand the growth conditions of lettuce under cadmium pollution, lettuce is used as the test material. Under different concentrations of cadmium stress and at different growth stages, relative chlorophyll content of lettuce leaves, the cadmium content in the leaves, and the visible-near infrared reflectance spectra are detected and analyzed. An inversion model of the cadmium content and relative chlorophyll content in the lettuce leaves is established. The results indicate that cadmium concentrations of 1 mg/kg and 5 mg/kg promote relative chlorophyll content, while concentrations of 10 mg/kg and 20 mg/kg inhibit relative chlorophyll content. The cadmium content in the leaves increases with increasing cadmium concentrations. Cadmium stress caused a "blue shift" in the red edge position only during the mature period, while the red valley position underwent a "blue shift" during the seedling and growth periods and a "red shift" during the mature period. The green peak position exhibited a "blue shift". After model validation, it was found that the model constructed using the ratio of red edge area to yellow edge area and the normalized values of red edge area and yellow edge area effectively estimated the cadmium content in lettuce leaves. The model established using the normalized vegetation index of the red edge and the ratio of the peak green value to red shoulder amplitude can effectively estimate the relative chlorophyll content in lettuce leaves. This study demonstrates that the visible-near infrared spectroscopy technique holds great potential for monitoring cadmium contamination and estimating chlorophyll content in lettuce. [ABSTRACT FROM AUTHOR]

5Cu-USY and Ce-doped 5Cu8Ce-USY zeolite catalysts were prepared by the conventional impregnation method. The obtained catalysts were subjected to the hydrothermal ageing process. The catalytic performance of the selective catalytic reduction of NOx with NH3 (NH3-SCR) was evaluated on both fresh and aged catalysts. Physical/chemical characterizations such as X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS) were performed, along with detailed in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) experiments including CO adsorption, NH3 adsorption, and NO + O2 reactions. Results showed that, for the 5Cu-USY catalyst, hydrothermal ageing treatment could somehow improve the low-temperature SCR activity, but it also led to significant formation of unfavorable byproducts NO2 and N2O. Such an activity change can be attributed to hydrothermal ageing inducing the migration of isolated Cu+ species in the sodalite cavities towards the super cages of the USY zeolites. The increased content of Cu+ species in the super cages was beneficial for the low-temperature activity improvement, but, at the same time, it also facilitated ammonia oxidation at high temperatures. Ce doping after hydrothermal ageing has a "double-edged sword" effect on the catalytic performance. First of all, Ce doping can inhibit Cu species migration by self-occupying the internal cage sites; thus, the catalytic performance of 5Cu8Ce-USY-700H remains stable after ageing. Secondly, Ce doping introduces a CuOx–CeO2 strong interaction, which facilitates lattice oxygen mobility by forming more oxygen vacancies so as to increase the concentration of surface active oxygen. These changes, on the one hand, could help to promote further oxidative decomposition of nitrate/nitrite intermediates and improve the catalytic performance. But, on the other hand, it also causes the byproduct generation to become more severe. [ABSTRACT FROM AUTHOR]

Grounded in the auspicious horizons of geological polymers as alternative replacements for Portland cement and aligned with the national endeavor of constructing an ecological civilization and harnessing solid waste as a resource, this study delves into the integration of nanostructured calcium carbonate (CaCO3) into geological polymers derived from fly ash and manganese slag. Employing a comprehensive methodology involving modalities, such as X-ray diffraction, scanning electron microscopy, and attenuated total reflectance Fourier-transform infrared spectroscopy, the influence of nano-CaCO3 on the compressive strength, pore architecture, and polymerization degree of geological polymers is meticulously unveiled. The outcomes reveal that nano-CaCO3 adeptly infiltrates the intricate microporous architecture of geological polymers, thereby providing a compact and intrinsically reinforcing matrix, ultimately endowing a marked increase in compressive strength. The assimilation of nano-CaCO3 correlates conspicuously with an increase in monomeric calcium concentrations, thereby catalyzing and expediting the formation of polymeric assemblages within the system, which in turn accelerates the progression of geological polymerization. This catalytic effect augments the intricate three-dimensional lattice-like gel structures, consequently orchestrating a substantial amelioration in mechanical attributes. When the dosage of nano-CaCO3 was 3.5%, sodium silicate was 10%, and NaOH was 12%, the integrated performance of fly ash–Mn slag geopolymer was optimal. Specifically, the 28-day compressive strength reached 25.6 MPa, and the compressive strength of the weathering performance test increased by 8.31%. The polymer achieved 96.77% curing of Mn, and it was non-radioactive. Thus, the prepared geopolymers are safe and reliable and support the subsequent development of nanomaterial activators. [ABSTRACT FROM AUTHOR]

This study presents the results and information revealed by in-depth physicochemical investigations carried out on an 18th-century polychrome wooden pedestal of the holy relics of Saint Demetrius Basarabov preserved at the Romanian Patriarchy of Bucharest. The preliminary stylistic observations and examinations on its present state of conservation were followed by optical microscopy, X-ray fluorescence (XRF) spectrometry, and attenuated total reflectance Fourier-transform infrared spectroscopy (FTIR-ATR) analysis performed in order to adopt an appropriate restoration treatment for bringing the artifact, as close as possible, to its original appearance as well as for dating/attributing the artifact and assessing its state of conservation. It was revealed that several interventions were subsequently undertaken on the original gilded surface consisting of a gypsum support layer with an iron oxide layer of bolus on which a silver foil or a gold foil and a natural resin on top of it as a protective layer were applied. The regilding and later restoration interventions consisted in applying, over the original, layers of a copper–zinc alloy foil (Dutch metal as an imitation of gold) with a resin layer of vernis over it. The final decision on the restoration intervention was taken based on the scientific analysis outcome. This work attempts also to highlight the importance of the interdisciplinary collaboration between researchers, conservation scientists, restorers/conservators, and curators for the preservation and valorization of the historical religious Romanian heritage artifacts, largely unknown worldwide. [ABSTRACT FROM AUTHOR]

Acetic acid (CH3COOH) detection with high selectivity at low temperatures is significant due to its wide applications in the chemical, medical, and catering industries. Chemiresistive gas sensors based on metal oxide semiconductors (MOSs) are widely used in detecting various gases, but it is necessary to develop MOSs with novel nanostructures to enhance gas‐sensing performance. Herein, a series of bismuth subcarbonate (Bi2O2CO3, abbreviated as BCO) microspheres with highly permeable lamellar structure and tunable Sn‐doping ratios (0–5 at%) is synthesized by controlling kinetics equilibrium of the hydrothermal reaction. The sensor based on 3 at% Sn‐doped BCO microspheres exhibits excellent gas‐sensing performances toward acetic acid (10 ppm), including high sensitivity (S = 8.3), fast recovery speed (10 s), long‐term stability (over 30 days), and good selectivity at a low temperature (150 °C). The unique permeable lamellar structure assembled from 2D Sn‐doped BCO nanosheets and rich Sn4+ doping‐induced active sites is mainly responsible for the enhanced gas‐sensing performances. Moreover, a new acetic acid reaction process is revealed via in situ diffuse reflectance infrared transform spectroscopy. Density functional theory calculations indicate that Sn‐doped BCO has a higher acetic acid adsorption energy and a larger charge transfer than pristine BCO. [ABSTRACT FROM AUTHOR]

Infrared reflectance spectroscopy has demonstrated potential as a tool for monitoring and preventing contamination in different environments. The objective of this study was to evaluate the usage of near-infrared spectroscopy for predicting heavy-metal contamination in mangrove soils from the Botafogo River estuary located in Pernambuco State, Northeastern Brazil. These soils exhibit the highest mercury (Hg) levels ever reported for Brazilian mangrove soils. Sixty-one samples (obtained at depths ranging from 0 to 5 cm) were collected and measured using near-infrared (1000–2500 nm) reflectance spectroscopy. Preprocessing methods were applied, and partial least squares regression was used to build prediction models for attributes such as clay content, soil organic matter (SOM), pH, Eh, and concentrations of Cr, Cu, Hg, Ni, Pb, and Zn. The models were evaluated using root mean squared error (RMSE), the adjusted coefficient of determination (R2adj), bias, the ratio of performance to interquartile distance (RPIQ), and Lin's concordance correlation coefficient (CCC). The best outcomes were noted for concentrations of Cr, Cu, Hg, Ni, and Pb (RPIQ > 2.5 and R2adj > 0.80); second-best outcomes were found for Zn and SOM (RPIQ > 1.5 and R2adj > 0.70). Clay content, pH and Eh exhibited the poorest outcomes (RPIQ < 1.5). The importance of spectral preprocessing is highlighted, notably with Savitzky-Golay derivatives and Multiplicative Scatter Corrections, which boosted performance for most of the variables. Near-infrared spectroscopy can be efficiently used to predict Cr, Cu, Hg, Ni, Pb and SOM and represents a technique complementary to traditional analyses. [ABSTRACT FROM AUTHOR]

Atmospheric balloons are the cheapest source utilized by scientists to investigate various research areas. Thermal analyses of atmospheric balloons is usually performed to attain the required thermal equilibrium in the shortest timeframe. In this paper, a mathematical model was developed that numerically solved material properties (i.e., ε (emissivity of balloon surface), αV (balloon absorptivity averaged over the visible and near infrared band), εIR (absorptivity averaged over infrared band), αIR (balloon absorptivity averaged over infrared band), etc.) as well as geometric properties (i.e., AC (cross-sectional area), AS (surface area), M (balloon mass), etc.) by incorporating these values in the heat balance equation. An optimized code was engendered in MATLAB, which simultaneously solved input parameters and delivered the required thermal equilibrium in the shortest timeframes. This may serve as a guide to new material generation. [ABSTRACT FROM AUTHOR]

Rational design/fabrication of high‐activity photocatalysts is of central importance to realize solar‐to‐chemical conversion for tackling worldwide energy/environmental issues. Hence, it is desirable to disclose the element/space/time‐resolved charge kinetics and surface species evolution of photocatalysts under realistic conditions using various in situ characterizations. Furthermore, the correlation of the above‐disclosed mechanisms with atomic‐scale compositions/structures of photocatalysts can further direct the atomic‐level design/synthesis of high‐performance photocatalysts. Herein, Ru atoms incorporated CdS quantum dots (QDs) are synthesized using an in situ hot‐injection route. The optimized Ru incorporated CdS QDs (Ru0.1) exhibit excellent photocatalytic evolution rates of H2O2 (8.78 mmol g−1 h−1) and benzaldehyde (11.70 mmol g−1 h−1), respectively. Four different in situ characterizations demonstrate that in realistic conditions, the incorporated Ru atoms with high oxidation state (+3) effectively attract photo‐generated electrons from bulk to the overall surface of Ru0.1; these directed electron flows also greatly facilitate the transfer of photo‐generated holes from bulk to surface of Ru0.1 via efficiently reducing electron‐hole recombination. in situ diffuse reflectance infrared Fourier transform spectroscopy, electron spin spectroscopy, and species‐trapping experiments further reveal three possible reaction pathways for H2O2 evolution. This work underscores the use of in situ characterizations to reveal the element/space/time‐resolved electrons/holes kinetics and surface‐species generation for photocatalysts in realistic conditions. [ABSTRACT FROM AUTHOR]

Chia oil is a source of α-linolenic (omega-3) fatty acid, which is known to promote human health but is highly prone to oxidation. Amylose (a polymer of α-1,4 D-glucose units) can molecularly encapsulate hydrophobic molecules, forming inclusion complexes that could potentially allow the incorporation of sensitive bioactive substances into functional foods. The evaluation of their oxidative stability is relevant to understand their behavior as delivery systems, but monitoring this parameter under real storage conditions requires long periods. In the present work, the oxidative stability of amylose-hydrolyzed chia oil inclusion complexes at 25 °C was estimated from the extrapolation of the exponential dependence of the Rancimat induction times determined at different temperatures (70–98 °C). The complexes were formed with high amylose corn starch and enzymatically hydrolyzed chia oil (10% or 20% hydrolysate/starch), with and without crystallization, using the KOH/HCl method followed by freeze-drying. The spectra of attenuated total reflectance Fourier-transform infrared spectroscopy revealed typical bands that confirmed the effective retention of chia oil fatty acids by the starch structure. The scanning electron micrographs showed that these samples were formed by irregular and porous solid particles. The induction time at 25 °C of crystallized complexes decreased with an increasing hydrolysate content, while the opposite was observed in non-crystallized complexes, as those formed with 20% hydrolysate were the ones that showed the highest stability. Although these findings should be confirmed under real storage conditions, the Rancimat results could be considered as a preliminary quick prediction of the behavior of inclusion complexes as carriers of omega-3 fatty acids. [ABSTRACT FROM AUTHOR]

For the first time the assembly of isolated and purified MCM‐41 nanoparticles into nanofibers was realized by electrospinning. Electrospinning was conducted with a dispersion of these nanoparticles and polyvinylpyrrolidone in ethanol. The nanofibers were characterized by electron microscopy, X‐ray diffraction, elemental analysis, gas physisorption and infrared spectroscopy in diffuse reflectance. The variation of the spinning parameters was investigated in detail towards the influence on the nanofiber diameter. The change of the applied voltage and the flow rate show strong impacts on the nanofiber diameter. Therefore, the nanofiber diameter can be tailored by choosing suitable electrospinning parameters. The fiber mats with thin nanofibers were then additionally functionalized with sulfonic acid groups in a proof of principal study. The nanofiber morphology was maintained both after functionalization with thiol group and subsequent oxidation to sulfonic acid groups. [ABSTRACT FROM AUTHOR]