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An interest in the study of the structural and optical properties of topological insulators, led to the selection of Bismuth telluride thin films. Among the topological insulators, Bismuth telluride is one of the promising materials that exhibit applications in the field of thermoelectric power generation. The films were prepared using the thermal evaporation method under vacuum conditions of 10−5 mbar on glass substrates maintained at a temperature of 120∘C. The thickness of the film samples ranges from 400 Å to 1400 Å. Pure phases of Bi2Te3 with a rhombohedral structure are confirmed using X-ray Diffraction. The crystallite size was calculated using Debye–Scherrer’s formula. Structural morphology and compositions are examined using SEM and EDAX. The UV–Vis study reflects the optical behavior of the thin film samples. The absorption spectra gives the direct and allowed transition band gap of the Bi2Te3 thin film samples for various thicknesses. The band gap decreases with the increase in the thickness of the Bi2Te3 thin films, suggesting that the material has significant absorption towards the visible spectrum. The Photoluminescence (PL) emissions for Bi2Te3 thin film samples of various thicknesses are examined and analysed. Raman study reveals the presence of two active modes. [ABSTRACT FROM AUTHOR]

AbstractTiO2 nanoparticles were synthesized using the reduction precipitation method, verified by powder x-ray diffraction (PXRD) with an average crystallite size of 62 nm and an average particle size of 135 nm from SEM images. Rheological studies of brake fluid with nanoparticle additives revealed that while the fluid generally maintains consistent behavior, a 2 wt.% concentration showed non-Newtonian behavior at 120 °C. Viscosity increased slightly with nanoparticle addition and decreased with rising temperature, with the 0.5 wt.% sample demonstrating the most notable increase of 18.18% at 120 °C. At 30 °C, the 1 wt.% sample exhibited a 4.06% increase. The observed viscosity changes are attributed to higher internal shear stress and the need to manage dispersion solid elements. The Herschel-Bulkley model was effective in predicting sample behavior, and all samples conformed to Reynolds’ equation μ0=be−aT. This research indicates that TiO2 nanoparticles can be effectively used as brake fluid additives, offering potential benefits for high-temperature applications in vehicles. Further optimization using mathematical models such as response surface methodology (RSM) is suggested for improved performance. [ABSTRACT FROM AUTHOR]

A second‐generation HIV protease enzyme inhibitor, darunavir is used in combination therapy for patients with history of prior antiretroviral treatments. It inhibits the cleavage of HIV encoded gag‐pol polyprotein in cells contaminated by a virus and thereby hinders the development of mature and infectious new virions. In this paper, optimization of molecular geometry of darunavir has been obtained by Density Functional Theory based B3LYP and ωB97XD methods with 6–311+G(d,p) basis set. The electro‐optical, global reactivity descriptors, and UV–visible spectrum of the drug have been examined using both the functionals. Further, binding affinity of darunavir at different sites of protein receptor (PDB ID: 5b18) has been analyzed using molecular docking technique. Results have been used to discuss electro‐optical and electronic properties of the drug along with its binding affinities with protein receptors. [ABSTRACT FROM AUTHOR]

HfO2 has allured the significant attention on account of its chemical and thermal stability, large bandgap value, high dielectric constant and refractive index, good transmittance values in ultraviolet and infrared bands establish it as a significant candidate for resistive switching oxide and optical materials. In the present work the effect of Ag ion beam with 120 MeV high energy treatment of HfO2 ALD grown thin films with thickness 40 nm is examined at distinct ion fluence from 1E12 to 1E13 ions/cm2. The present work reports the influence of 120 MeV Ag ion beam irradiation on the optical, structural and morphological characteristics of thin films grown by ALD method on glass and silicon substrate. The Tauc plots have been used to calculate the optical bandgap of films give the details of structure of films on account of slope of the plot is associated with the degree of the order in the network of bond. The SRIM simulation has been explored for the study of electronic and nuclear energy loss takes place in the samples. Structural analysis of pristine and ion beam irradiated thin films were studied by the X-ray diffraction technique. The effect of ion beam irradiation on the surface morphology were studied by the Atomic Force Microscopy (AFM), reveals that grain size rely on the variation takes place in the ion beam fluence. The ion beam causes surface state and interstitial defects in thin films samples as remarked by the Photoluminescence characterization method. Additionally, the RBS was used for the calculation of thickness of films. [ABSTRACT FROM AUTHOR]

The current work describes a biological method to create silver nanoparticles (AgNPs) using jojoba oil. As a reducing and capping agent, jojoba oil was utilized in the production of AgNPs. AgNPs may be classified by their UV-VIS, FTIR, and spectra. A transmission electron microscope (TEM) was used to examine the shape and size of the silver nanoparticles. The average size of the synthesized silver nanoparticles was 25.6 ± 10.3 nm, and they had a spherical shape. According to FTIR spectroscopy tests, the silver nanoparticles' surface had organic molecules bound to it. Five bacterial isolates were isolated and tested for pathogenicity on potatoes. All isolates produced the typical symptoms of soft rot disease. Isolate Pcc2 caused the highest disease severity (45%). According to 16sRNA, isolate Pcc2 was identified as Pectobacterium carotovorum subsp. carotovorum. Increasing the dosage of AgNPs increased the antibacterial effect against P. carotovorum. From these results, we can conclude that the use of AgNPs is a safe method for controlling postharvest potato diseases caused by Pectobacterium carotovorum subsp. carotovorum. [ABSTRACT FROM AUTHOR]

WO3 is considered to be significant for diverse applications such as gas sensing, photocatalysts, and photovoltaic devices because of its optical wide band gap. Ion beam treatment of various metal oxides produces defects that modify various properties such as topographical, structural, and optical characteristics of the metal oxides. When the energetic ion pass through the target materials, it causes two kinds of energy losses, i.e., nuclear and electronic energy loss. In low-energy ion beam treatment of thin films, nuclear energy loss dominates over electronic energy loss. In our current study, thin films of tungsten oxide were grown on substrates of glass and silicon by the RF-sputtering method. The sputtered WO3 thin films were exposed to an ion beam of Au iosn with an energy of 80 keV at various fluences of 5E14 ions/cm2, 1E15 ions/cm2, and 5E15 ions/cm2. Atomic force microscopy (AFM) shows that, after implantation, enhancement in grain size was observed from 49.5 nm to 56.6 nm. The optical study displays the alteration in the energy band gap of ion-implanted WO3 thin films from 2.75 eV to 2.99 eV. From Raman spectroscopy, the phase observed is monoclinic for virgin and implanted samples. PL spectroscopy of virgin and ion beam-implanted WO3 thin films shows emission spectra at the wavelength of 580 nm at an excitation wavelength of 420 nm. X-ray photoelectron spectroscopy shows the appearance of tungsten and oxygen atoms and shows the electronic structure variation after Au ion beam implantation. [ABSTRACT FROM AUTHOR]

The advancement of crystalline growth and characterization tools allows us to investigate novel nonlinear optical substances suitable for photonic applications. Bis-(4-aminopyridine)-zinc(II) acetate (B4AZA), a metal–organic crystal was produced in this study using the slow evaporation procedure at room temperature. Analytical studies such as X-ray crystallography, Fourier transform infrared (FT-IR), UV–visible (UV–Vis), fluorescence, second harmonic generation (SHG), and dielectric tests were used to characterize the as-grown B4AZA crystals. According to the solubility data, the sample has a positive temperature coefficient of solubility. The crystallographic findings show that the B4AZA crystallized in a monoclinic structure with the P21/n space group. Molecular vibrations and functional groups in the substance were determined using the FT-IR technique. The UV–Vis absorbance and transmittance spectra have shown the wide transparency and minimum absorbance of the B4AZA in the near UV and entire visible regions of the electromagnetic spectrum. The bandgap of the B4AZA has been calculated using the Tauc relation and found to be 4.32 eV. The fluorescence spectra have shown a prominent emission peak at 584 nm with an excitation wavelength of 280 nm. The larger Stokes shift found in the fluorescence spectra is advantageous for practical applications. The SHG study revealed that the powdered B4AZA samples generated a second harmonic output. The dielectric test revealed frequency-dependent changes in the dielectric constant and loss factor. Both the dielectric constant and the loss factor decrease exponentially as frequency increases, reaching low values at higher frequencies. The experimental results illustrate the suitability of the B4AZA crystals for photonic applications. [ABSTRACT FROM AUTHOR]

Silver nanoparticles can be produced by an array of procedures, such as chemical, physical, and biological processes. The process of biosynthesis is more economical and significantly more environmentally friendly. We describe an environmentally compatible method (biosynthesis) of producing silver nanoparticles (Ag: NPs) with the capping component Artocarpus heterophyllus in this research work. Powder-X-ray crystallography (P-XRD), Fourier Transform Infrared (FT-IR), UV–visible (UV–Vis), Photoluminescence (PL), Field emission scanning electron microscopy (FE-SEM), and an antimicrobial test were all used to examine the synthesized samples. The P-XRD analysis revealed that the produced NPs have an FCC form with a typical particle size of 23 nm. FT-IR spectra further demonstrate the availability of the functional groups in the synthesized nanoparticles. The absorbance and transmittance spectra of the UV–Vis study have shown substantial transparency and less absorbance of the Ag: NPs in the entire visible region. The bandgap of the Ag: NPs was found to be 3.25 eV using the Tauc relation. In the PL study, an emission peak at 472 nm was found, suggesting the fluorescence emission of Ag: NPs. The FE-SEM micrographs provide confirmation of the surface-wide aggregate of nanostructural homogeneities. The FE-SEM micrographs illustrate that Ag: NPs are homogeneous aggregates of very small spheres. Variations in particle size and surface area-to-volume ratios of synthesized NPs have been proven to be responsible for the antibacterial activities. According to the antibacterial study, Ag: NPs restrain the development of both normal and harmful bacteria and so have the potential to be utilized for coating surgical equipment for aseptic operators in the healthcare industry. [ABSTRACT FROM AUTHOR]

Watermelon suffers substantial post-harvest losses owing to strict quality standards, resulting in 20–30% of the crop being left unharvested. This study investigated the potential of valorizing dried watermelon pomace (DWP), a byproduct of watermelon juice extraction, focusing on its lycopene content—a potent antioxidant. This study assessed lycopene stability in DWP from four watermelon cultivars (Perla Nera®, Gavina®, Crimson Sweet, and Asahi Miyako) under different storage conditions (vial-sealed and vacuum-sealed). The lycopene content in freshly prepared DWP samples ranged from 0.734 to 1.572 mg/g db. The results indicated that vacuum-sealed samples exhibited significantly slower lycopene degradation than vial-sealed samples, highlighting the impact of air exposure on lycopene stability. After 90 days of storage, lycopene content in vacuum-sealed samples ranged from 0.214 to 1.234 mg/g db, while that in vial-sealed samples ranged from 0.013 to 0.731 mg/g db. Furthermore, this study assessed the effect of pretreatments with ascorbic acid (pretreatment A) and a mixture of ascorbic and citric acids (pretreatment B) on lycopene stability. Pretreatment B showed superior effectiveness, yielding higher lycopene levels than pretreatment A (p < 0.05). The stabilizing effects of ascorbic acid and citric acid were attributed to their antioxidant properties and their roles as pH regulators and chelators. [ABSTRACT FROM AUTHOR]

A paramagnetic A3B-type Mn(III)-porphyrin was synthesized and characterized by physical–chemical methods (UV-Vis, FT-IR, 1H-NMR spectroscopy). The obtained compound was tested as a sensitive material for the spectrophotometric and potentiometric detection of iodine species. Using UV-Vis spectroscopy, the triiodide anions could be detected with high precision in the concentration interval of 1.02 × 10−5 to 2.3 × 10−5 M, with an LOD of 9.44 × 10−6 M. The PVC-based electrode using DOP as a plasticizer showed a sensitivity toward iodide in a wide concentration range of 1.0 × 10−5 to 1.0 × 10−1 M, with an LOD of 8.0 × 10−6 M. Both methods are simple, low-cost, and efficient for the detection of iodine species in synthetic samples and pharmaceuticals. [ABSTRACT FROM AUTHOR]

In this study, xCaO‧5Fe2O3‧(95−x)Pb glasses and vitroceramics containing various concentrations of calcium ions (from 0 to 50 mol% CaO) were prepared using the spent anodic plate of a car battery. X-ray diffraction analysis revealed changes in the network structure as a function of CaO content. The intensities of the IR bands due to the sulfate and sulfite units were lowered, indicating a decrease in the sulfurization degree within the lead network. In the UV–vis spectra, the presence of electronic transitions of the Fe3+, Pb2+, and Fe2+ ions were identified. The EPR spectra were characterized by resonance signals centered at about g ~ 2 and 4.3, corresponding to the trivalent iron ions. For the samples with 5 ≤ x ≤ 12, the signals decreased abruptly, suggesting a Fe3+→Fe2+ interconversion and the formation of the Fe3O4 crystalline phase. A considerable increase in the intensity of the signal centered around g ~ 2 was observed as the CaO concentration increased to 30% in the host matrix. Our results confirm that the higher CaO levels of 3 mol% are responsible for the increase in the radius of curvature of the semicircle arcs in the EIS plots and the decrease in their conductivity. [ABSTRACT FROM AUTHOR]

A sensitive, accurate, and affordable colorimetric method was developed for assaying prednisolone (PRZ) in various medicinal forms. The procedure involves the oxidation of PRZ by ferric ions, followed by complexation of the resulting ferrous ions with ferricyanide to produce a greenish-blue product. Common complexation conditions were thoroughly investigated. The mole ratio of FeCl3·6H2O to K3Fe(CN)6 was 8:1. The proposed mechanism of complexation was suggested and considered. Various parameters were optimized, including the reduction of the colorimetric reaction temperature to 50°C and the duration of heating and analysis to 20-30 minutes. The calibration curve was linear over the range of 1-60 µg/mL. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.5 µg/mL and 1 µg/mL, respectively. Spiking actual samples with standard PRZ showed recoveries within the 97.3-100.1% range. The method exhibited high precision, with an RSD% of less than 1.5%. Additionally, the study confirmed that common pharmaceutical excipients did not interfere. Real medicinal samples, including tablets, syrup, eye drops, and creams, were successfully examined for direct analysis of PRZ using the developed methodology, demonstrating its suitability for routine analysis of various PRZ-containing drug formulations. [ABSTRACT FROM AUTHOR]

In this study, homogeneous NiO particles on ZnO heterojunction were incorporated with the objective of scrutinizing its probable applications in antifungal processes. Advanced instruments were engrossed to determine the phase identification, elemental composition, and particle discrepancy of the synthesized material. The electrochemical impedance response was pondered using Nyquist diagrams to accredit an equivalent circuit and extract fundamental circuit parameters. The Z″ versus Z′ plot plugged a semicircular shape, broaching the presence of heterogeneous or broad relaxation processes. The antifungal efficacy of the homogeneous NiO on ZnO heterojunction was appraised against various fungi species, including Aspergillus Niger, Aspergillus flavus, Rhizopus microspores, and Pencillium sp., at a concentration of 20 µl. These results accentuated the versatile applicability of the studied material. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate changes in the degree of C=C conversion (DC%), chemical structure, optical properties and roughness of one-shade composites before/after photoaging. Τhe one-shade materials tested were Charisma Topaz One (CHT), Clearfil Majesty ES-2 Universal (MES), Essentia Universal (ESU) and Omnichroma (OMN), with G-aenial Anterior (CNA) serving as control. Specimens (2 mm thickness) were prepared and tested for DC% and chemical structure (ATR–FTIR spectroscopy), optical properties (L*a*b*–ΔΕ, translucency parameter–TP, opalescence parameter–OP, contrast ratio–CR and total transmittance–TT by UV–Vis spectroscopy) and roughness (Sa, Sz, Sdr, Sds and Sc by optical profilometry) before and after photoaging (Xe-arc weatherometer). Significant differences were found in DC% between top–bottom surfaces (ESU, OMN before; ESU, CNA after). Photoaging improved DC%, reduced ester peaks implying photodegradation, reduced L* (CHT, OMN, CNA), a* (CHT, CNA), b* (OMN, CNA), TP (all, except for MES), OP (only MES), CR (only MES, but an increase in CNA) and TT (CHT, OMN). OMN, CNA and MES demonstrated ΔΕ > 3.3. Photoaging significantly increased all roughness parameters in all materials, except for MES (Sz, Sdr, Sc) and OMN (Sdr). Although listed in the same group, significant differences were found in one-shade composites before and after photoaging. Several products were strongly affected by photoaging, demonstrating evidence of photodegradation, an increased roughness and color changes exceeding the clinically acceptable levels. [ABSTRACT FROM AUTHOR]

This study intended to synthesize Nickel-doped Cerium oxide (Ni-CeO2 NPs) nanoparticles using Pedalium Murex leaf extract. X-ray diffraction (XRD) was used to investigate the structure of the Ni-CeO2 NPs. The XRD measurements showed that the Ni-CeO2 NPs crystallized into the face-centered cubic system. The Ni(1%)-CeO2 and Ni(3%)-CeO2 NP’s crystallite sizes were between 47nm and 59nm. FTIR and Raman spectral studies were conducted to investigate the sample’s atomic vibrations and chemical bonding. Energy-dispersive X-ray study and field-emission scanning electron microscopy were performed to examine the surface texture and chemical assembly of the Ni-CeO2 NPs. UV–Vis DRS spectrum study was performed to ascertain the reflectance characteristics and bandgap of Ni-CeO2 NPs. The Ni(1%)-CeO2 and Ni(3%)-CeO2 NPs were found to have bandgaps of 2.73eV and 2.82eV, respectively. Electrochemical impedance spectroscopy and cyclic voltammetry were employed to explore the electrochemical nature of Ni-CeO2 NPs and their capacitive properties at various scanning rates. Using the agar well-diffusion technique, the antifungal activities of Ni-CeO2 NPs were assessed. The experimental findings illustrate the utility of Ni-CeO2 NPs for supercapacitor electrode material and healthcare applications. [ABSTRACT FROM AUTHOR]

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Abstract\nHighlightsThe calcium ferrite nanoparticles were made by the sol–gel process. X-ray diffraction, a scanning electron microscope, and UV–vis spectroscopy were used to analyze the material. There is an orthorhombic phase in the space group Pnma. There were four techniques used to calculate the average crystallite size. Using ImageJ software, the particles were aggregated and their size was ascertained. Using energy-dispersive X-ray (EDX) analysis, the composition of the material was ascertained. 2.29 eV was determined to be the band gap. Vibrating test magnetometer (VSM) provided an explanation for the materials’ magnetic property. A decreased band gap energy is responsible for the 90% degradation of malachite green dye at a concentration of 15 mg/L in 150 min, with a four-cycle reusability.Calcium ferrite nanoparticles were successfully synthesized by sol–gel assisted combustion method using leaf extract of Brassica oleracea as fuel.To the best of the author’s knowledge, no such case study that reports the synthesis of calcium ferrite nanoparticles by using leaf extract of Brassica oleracea is previously reported in academic literature.The method is cost-effective and convenient without the use of any chemical fuel agents.The synthesized prepared material efficiently removes malachite green dye, commonly used in industries for dyeing silk and nylon, from the solution.More than 90 % removal efficiency for MB.The material displayed excellent stability and reusability for dyes adsorption.Results were validated with pseudo-first-order kinetic model.Calcium ferrite nanoparticles were successfully synthesized by sol–gel assisted combustion method using leaf extract of Brassica oleracea as fuel.To the best of the author’s knowledge, no such case study that reports the synthesis of calcium ferrite nanoparticles by using leaf extract of Brassica oleracea is previously reported in academic literature.The method is cost-effective and convenient without the use of any chemical fuel agents.The synthesized prepared material efficiently removes malachite green dye, commonly used in industries for dyeing silk and nylon, from the solution.More than 90 % removal efficiency for MB.The material displayed excellent stability and reusability for dyes adsorption.Results were validated with pseudo-first-order kinetic model. [ABSTRACT FROM AUTHOR]

In the United States, illicit fentanyl is often trafficked as blue tablets mimicking the legitimate M‐30 oxycodone tablet produced by Mallinckrodt. The analysis of dyes extracted from seized fentanyl tablets could provide a useful tool for law enforcement to establish linkages between cases and could prove useful for attributing a seizure to a given trafficking organization. Fentanyl tablet seizures associated with a particular drug trafficking organization (DTO), either through investigative or intelligence information, were used as the sample set for this study. The blue dye from the tablets was isolated by solid phase extraction and then qualitatively and quantitatively analyzed via ultraviolet‐visible spectroscopy. This research revealed that the illicit tableting facilities use a different dye than several known pharmaceutical companies. The concentration of dye in individual tablets within a seizure proved to be very minimal, and the small sample size made it difficult to draw linkages from case to case. Analysis of the dyes could not effectively differentiate between the drug trafficking organizations in the tested population due to each DTO using the same dye; however, it is important to note that the dye found was consistent between illicit tablets. [ABSTRACT FROM AUTHOR]

The photochemistry of Fe(III)-Iminodiacetic acid complex (Fe(III)-IDA) was studied under UVA and UV/Vis irradiation. The synthesis was realised via molar ratio method modified by reaction of IDA as ligand with Fe(III) as metal. The interaction of Fe(III) with IDA was characterised using Fourier-transform infrared (FTIR) and spectroscopy UV–visible. The results confirmed the stability of the complex at pH > 5; with constant of stability (Log β = 10.02) and stoichiometry Fe(III): IDA = 1:1. In addition, the redox potential was calculated at 521 mV, which is significantly lower than E° for the Fe(III)/Fe(II) couple. The photolysis of this complex in the presence of UVA light and UV/Vis light at different pHs was carried out. This photolysis was followed by several assay Fe(II) and •OH. The results show that the Fe(III)-IDA complex present a photo-reactivities under either light source and the phenomenon is faster when the UV/Vis was used. The initial conversion rate (r0) decreased with increasing of initial pH. The formation of hydroxyl radicals via the Fenton reaction was improved at pH = 2.12 for both irradiation sources used. Reduction of total organic carbon was also studied using the total organic carbon (TOC). The feasibility of amino iron complexes to improve the Fenton process under irradiation was confirmed. Additionally, our research also evidenced the optimal conditions for the formation of hydroxyl radicals; which are the key factor in remove pharmaceuticals pollutants in aqueous media. Based on the results obtained, the Fe(III)-IDA complex could be efficiently photolysis under UV/Vis light. [ABSTRACT FROM AUTHOR]

Here, ultrasonic spray pyrolysis method (USP) was utilized to produce pure and silver doped copper oxide nanostructures on glass substrates. Thereafter, several characterization techniques were conducted on the grown samples to delve into their morphological, structural, electrochemical, and optical aspects. The mentioned analyses were carried out by performing x-ray photoelectron spectroscopy, scanning electron microscope, X-ray diffraction, electrochemical impedance spectroscopy, galvostatic charge-discharge, cyclic voltammetry, and UV–visible spectroscopy measurements. Thus, the impact of silver impurity doping on the relevant aspects of host material were recorded as well as the features of unspoiled copper oxide films. Accordingly, the samples, as indicated by X-ray diffraction results, possessed (002) preferential plane orientation of copper oxide material along with the crystallite sizes ranging from 52.52 nm to 75.02 nm due to the imperfections caused by the silver doping. The scanning electron microscope images exhibited that the silver doping did not form significant modifications in the host material morphology where nanowire-like structures observed. The presence of the suggested materials in the films was verified by the x-ray photoelectron spectroscopy. Also, the UV–visible spectroscopy measurements detected that optical absorbance edge and bandgap energy values red shifted as a result of the impurity doping. The electrochemical supercapacitors performances of the silver doped copper oxide nanostructured thin films were inspected by using the GCD, EIS, and CV. The silver doped copper oxide films demonstrated a specific capacitance value of 66 F/g at a current density of 1 A/g in 1 M KOH electrolyte. From Nyquist plot, Rs, Rcor, Rpo, Ccor and Cc were obtained as 2.327 × 103 Ω.cm2, 43.63 × 103 Ω.cm2, 4.580 × 103 Ω.cm2, 111.5 × 10-6 S*s^a. cm-2 and 101.1 × 10-6 S*s^a. cm-2, respectively. The results indicated that the electrochemically synthesized the silver doped copper oxide electrodes can be obtained and developed as an alternative electrode material for supercapacitors (SCs). [ABSTRACT FROM AUTHOR]

Non-linear optical materials have greatly impacted science and technology in recent years. In the present work, crystals of amino acid derivative l-histidinium acetate dihydrate (L-HA) were grown using the gradual evaporation method. The powder-crystal X-ray diffraction (PXRD) technique was applied to examine the phase composition of the crystal sample. The XRD analysis showed that the L-HA was crystallized into the triclinic system. Microstructural parameters were evaluated, including dislocation density and micro-strain induced in the samples. The vibrational modes of the L-HA crystal were found using confocal Raman spectrum analysis. UV–Vis spectral analysis was applied to ascertain the crystal's optical absorbance and transmittance. The bandgap and Urbach edge of L-HA were explored in the UV–Vis spectrum. The second harmonic generation potency of L-HA was examined using Kurtz–Perry analysis, and it was found that L-HA exhibited significant SHG efficiency. The dielectric and impedance characteristics of the L-HA were assessed in the 100 Hz‒5 MHz range at different temperatures. Dielectric measurements show that at frequencies higher than 10 kHz, the dielectric constant and dielectric loss are saturated at minimum levels. The Nyquist graph displays the negative temperature coefficient of resistance in the compound. Vickers microhardness analysis demonstrates the normal indentation size effect and hard nature of the L-HA sample. Thus, the L-HA crystals are suitable for optoelectronic applications due to their excellent optical characteristics, considerable SHG efficiency, and appropriate dielectric, impedance, and microhardness features. [ABSTRACT FROM AUTHOR]

First synthesized in 1868, alizarin became one of the first synthetic dyes and was widely used as a red dye in the textile industry, making it more affordable and readily available than the traditional red dyes derived from natural sources. Despite extensive both experimental and computational analyses on the electronic effects of substituents on the shape of the visible spectrum of alizarin and alizarin Red S, no previous systematic work has been undertaken with the aim to fine tune the dominant absorption region defining its color by introducing other electron‐withdrawing or electron‐donor groups. For such, we have performed a comprehensive study of electronic effects of substituents in position C3 of alizarin by means of a time dependent DFT approach. These auxochromes attached to the chromophore are proven to alter both the wavelength and intensity of absorption. It is shown that the introduction of an electron‐donor group in alizarin causes the transition bands to be significantly red‐shifted whereas electron‐withdrawing groups cause a minor blue‐shifting. [ABSTRACT FROM AUTHOR]

Calcium molybdate (CaMoO 4) and Dy3+ doped CaMoO 4 (Dy3+ = 0.5, 1, 1.5, 2 and 2.5 at.%) nanoparticles were successfully obtained by mechanochemical approach. The influence of Dy3+ ion concentration on the structure, morphology, and photoluminescent properties were investigated. The CaMoO 4 and Dy3+ doped CaMoO 4 phases with tetragonal structure were completely prepared after 30 min milling time with applied milling speed of 850 rpm. TEM analysis shows that the synthesized samples consist of mainly spherical particles with narrow particle size distribution. According to both XRD and TEM analysis, the average particles size is below 40 nm. The UV–vis absorption spectra show one peak at 240–245 nm. The calculated optical band gap of pure CaMoO 4 is 3.96 eV and it decreases to 3.65 eV with increasing the concentration of Dy3+ ion up to 2.5 at %. The excitation spectra of the Dy3+-doped CaMoO 4 samples contain absorption peaks corresponding to the MoO 4 group and to the Dy3+ ion. The green and blue light emissions were observed for pure CaMoO 4 and Dy3+ doped CaMoO 4 samples under different wavelengths excitation (250 and 350 nm) typical for absorption of the host matrix. Emission spectra of all doped powders consist of the characteristic peaks of Dy3+ in the blue (∼480 nm) and yellow (∼575 nm) regions which are assigned to the 4F 9/2 → 6H 15/2 and 4F 9/2 → 6H 13/2 transitions, respectively. The weak peak at 660 nm also is observed due to 4F 9/2 → 6H 11/2 transition of Dy3+ ion. The highest photoluminescence emission intensity was detected when the sample is doped with 1.5 at.% Dy3+ concentration. It was found that the color coordinates (x and y) of 1.5 at.% and 2 at.% Dy3+-doped CaMoO 4 fall close to the white light region in the CIE diagram. The results indicate that the mechanochemically obtained Dy3+ doped CaMoO 4 nanoparticles can find application in different optical instruments. [ABSTRACT FROM AUTHOR]

In this work, poly(p-aminophenol), a conductive polymer, was synthesized via chemical polymerization from the monomer of p-aminophenol in a basic aqueous medium using ammonium persulfate as the initiator. The polymer's properties were assessed using ultraviolet-visible spectroscopy, fourier transform infrared, thermogravimetric analysis, scanning electron microscope, and X-ray diffraction methods. The fourier transform infrared results show a peak such as the robust signal at 3126 cm–1, corresponding to O–H vibrations associated with phenoxide ion existence in the polymer. The presence of N–H stretching vibration of an aromatic amine was affirmed by the peak at 2989 cm–1. The presence of a strong, broad peak at 2θ of 17.52° indicated amorphous behavior in poly(p-aminophenol). The weight loss was shown at 87, 276 and 517°C due to moisture removal, anion removal, and the degradation of polymer. Scanning electron microscopy showed sphere-like particles in poly(p-aminophenol) surface morphology. The electronic properties of poly(p-aminophenol) were investigated using quantum chemical calculations at the density functional theory level of theory. Density functional theory calculations were performed using two functionals, namely B3LYP and wB97XD, in combination with the 6-311+G(2d, p) basis set. These calculations aimed to determine various quantum chemical parameters, conduct natural bond orbital analysis, assess topological parameters, investigate nonlinear optical properties, and evaluate thermal properties. This approach balanced computational efficiency and accuracy to investigate reactivity, stability, charge transfer, optical properties, and thermal behavior. The calculations revealed significant changes in the reactivity and stability of the studied compound as it transitioned from the non-protonated to the protonated state, analyzed in both the gas phase and various aqueous environments. Furthermore, the presence of strong hydrogen bonds and limited nonlinear optical potential suggest the material may be suitable for applications beyond nonlinear optics. Additionally, the calculations explored static thermodynamic properties, including heat capacity, entropy, and enthalpy, highlighting their temperature-dependent behaviors. Poly(p-aminophenol) has excellent thermal stability and robust hydrogen bonding. However, its low nonlinear optical potential indicates its usefulness for uses other than nonlinear optics. [ABSTRACT FROM AUTHOR]

By employing the melt-quenching technique, the ZnO–SrO–B2O3–PbO (ZSBP) glasses have been successfully fabricated. The derivative of Absorption Spectra Fitting (DASF) method was used to study the energy band gap (Eg) of the glasses which decreases from 3.57 eV to 3.39 eV. The structural properties have been studied using the Raman spectroscopy. The glass transition temperature (Tg) decreases with increase in concentration of the lead oxide. The current study examines the radiation shielding properties at 30.80–444 keV. The addition of PbO to the glasses resulted in a proportionate increase in the mass attenuation coefficient (MAC), suggesting a diminishing tendency in radiation transmission. At 30.80 keV, the MAC values are extremely high and range from 18.06 to 21.11 cm2/g. As density rises, the half value layer (HVL) decreases. In addition, the average HVL (HVL‾) decreases. The glass thickness required to reduce the radiation intensity to 90 %, 50 %, 25 %, and 10 % of its initial value is investigated at an energy of 35.80 keV. The T90 %, T50 %, T25 %, and T10 % values are 0.0020, 0.0132, 0.0264, and 0.0439 cm, respectively. The results suggest that a greater thickness of the radiation barrier is necessary to attain the necessary degree of attenuation.

Watermelon suffers substantial post-harvest losses owing to strict quality standards, resulting in 20–30% of the crop being left unharvested. This study investigated the potential of valorizing dried watermelon pomace (DWP), a byproduct of watermelon juice extraction, focusing on its lycopene content—a potent antioxidant. This study assessed lycopene stability in DWP from four watermelon cultivars (Perla Nera®, Gavina®, Crimson Sweet, and Asahi Miyako) under different storage conditions (vial-sealed and vacuum-sealed). The lycopene content in freshly prepared DWP samples ranged from 0.734 to 1.572 mg/g db. The results indicated that vacuum-sealed samples exhibited significantly slower lycopene degradation than vial-sealed samples, highlighting the impact of air exposure on lycopene stability. After 90 days of storage, lycopene content in vacuum-sealed samples ranged from 0.214 to 1.234 mg/g db, while that in vial-sealed samples ranged from 0.013 to 0.731 mg/g db. Furthermore, this study assessed the effect of pretreatments with ascorbic acid (pretreatment A) and a mixture of ascorbic and citric acids (pretreatment B) on lycopene stability. Pretreatment B showed superior effectiveness, yielding higher lycopene levels than pretreatment A (p < 0.05). The stabilizing effects of ascorbic acid and citric acid were attributed to their antioxidant properties and their roles as pH regulators and chelators.

In this work silver nano/micro-particles have been synthesized using sambiloto (Andrographis paniculata) plant extract as a bio-reducing agent. The effects of different plant extract concentrations, AgNO3 precursor concentrations, and reaction time on the synthesized silver nano/micro-particles were investigated. The silver nano/micro-particles samples were then analyzed using UV-Vis spectrophotometer (UV-Vis), X-Ray Diffractometer (XRD), Field Emission Scanning Electron Microscopy (FESEM), Particle Size Analyzer (PSA), and Fourier Transform Infra-Red (FTIR) spectroscopy. The UV-Vis absorbance spectrum of the colloid silver nano/micro-particles exhibited that all samples had absorbance peaks at a wavelength around 450 nm, confirming the formation of silver nano/micro-particles. It was also found that the UV-Vis absorbance peak of the silver nano/micro-particles inversely increased with decreasing AgNO3 solution concentration. Whereas, the higher the sambiloto extract concentration the higher the UV-Vis absorbance peaks. The UV-Vis absorbance peak increased with increasing synthesis time, suggesting that silver nano/micro-particles became more prominent. The UV-Vis absorbance peaks of the silver nano/micro-particles were about 0.0462, 0.0637, 0.0729, and 0.0936 at reaction time of 5, 10, 20, and 40 min, respectively. The XRD analysis result confirmed that the synthesized silver nano/micro-particles were in the form of nanocrystals with a face-centered cubic centered without any impurities. Additionally, the FESEM images showed that the silver nano/micro-particles had the primary particle size of 150-300 nm. There was the formation of some secondary particles with the size of about 0.7-1.5?m due to the agglomeration of primary particles. The particle size distribution analysis further confirmed the presence of primary and secondary particles. Meanwhile, the FTIR analysis confirmed the presence of four main peaks, linked to functional groups in the sambiloto extract and involved in the creation of silver nano/micro-particles.

The manuscript presents the optical properties of directly deposited films of gold nanoparticles (AuNPs) prepared by the Ultrasonic Spray Pyrolysis (USP) technology. Four samples were produced, with AuNP deposition times on the glass substrate of 15 min, 30 min, 1 h and 4 h. The morphological characterisation of the deposited films showed that the size of the first deposited AuNPs was between 10 and 30 nm, while, with a longer duration of the deposition process, larger clusters of AuNPs grew by coalescence and aggregation. The prepared layers were characterised optically with Ultraviolet–visible spectroscopy (UV–vis) and ellipsometry. The ellipsometric measurements showed an increasingly denser and thicker effective thickness of the AuNP layers. The extinction spectra displayed a clear local surface plasmonic resonance (LSPR) signature (peak 520–540 nm), indicating the presence of isolated particles in all the samples. For all AuNP layers, the imaginary part of the parallel and perpendicular components of the anisotropic dielectric function was dominated by a central peak at around 2.2 eV, corresponding to the LSPR of isolated particles, and a high-energy shoulder due to Au interband transitions. It was shown that, as the density of particles increased, the extinction cross-section grew over the whole spectral range where measurements are taken. Thus, the response can be explained with an enhanced electromagnetic response between the AuNPs that can be connected to the increase in particle density, but also by the formation of clusters and irregular structures.

To solve environmental-related issues (wastewater remediation, energy conservation and air purification) caused by rapid urbanization and industrialization, synthesis of novel and modified nanostructured photocatalyst has received increasing attention in recent years. We herein report the facile synthesis of in situ nitrogen-doped chemically anchored TiO2 with graphene through sol–gel method. The structural analysis using X-ray diffraction showed that the crystalline nitrogen-doped graphene-titanium dioxide (N-GT) nanocomposite is mainly composed of anatase with minor brookite phase. Raman spectroscopy revealed the graphene characteristic band presence at low intensity level in addition to the main bands of anatase TiO2. X-ray photoelectron spectroscopy analysis disclosed the chemical bonding of TiO2 with graphene via Ti–O-C linkage, also the substitution of nitrogen dopant in both TiO2 lattice and into the skeleton of graphene nanoflakes. UV–Vis absorption spectroscopy analysis established that the modified material can efficiently absorb the longer wavelength range photons due to its narrowed band gap. The N0.06-GT material showed the highest degradation efficiency over methylene blue (MB, ∼98%) under UV and sulfamethoxazole (SMX, ∼ 90.0%) under visible light irradiation. The increased activity of the composite is credited to the synergistic effect of high surface area via greater adsorption capacity, narrowed band gap via increased photon absorption, and reduced e−/h+ recombination via good electron acceptability of graphene nanoflakes and defect sites (Ti3+ and oxygen vacancy (Vo)). The ROS experiments further depict that primarily hydroxyl radicals (OH•) and superoxide anions (O2•−) are responsible for the pollutant degradation in the process redox reactions. In summary, our findings specify new insight into the fabrication of this new material whose efficiency can be further tested in applications like H2 production, CO2 conversion to value-added products, and in energy conservation and storage. [ABSTRACT FROM AUTHOR]

In recent years, interest has been found by the scientific community in studying nanoparticles (NPs) and exploring the vast diversity of applications they have, even as an alternative to materials used conventionally. A key step in the study of nanoparticles is the analysis of their optical properties, since these reveal information on their stability, purity, and interactions with UV-vis radiation, and help to confirm the identity of the nature of the nanoparticles. In this project, samples of copper and manganese oxide nanoparticles were synthesized and studied, with the aim of understanding key points in the behaviour of these. Observed peaks on UV-Vis spectra allowed to confirm the identity of the nanoparticles produced, with results showing high stability for CuO NPs synthesized in water and methanol; MnO2 NPs were found to be unstable in water, due to nanoparticle agglomeration. The analysis of surface plasmon resonance peaks showed the presence of oxidation reactions during the ablation process. Estimated band gap values were 5,44 and 3,77 eV, for CuO and MnO2 nanoparticles respectively, which rules out any possible application of these NPs as semiconductor materials. CuO nanoparticles have a potential application as an antibacterial material, due to its high stability in water and copper's natural cytotoxicity. [ABSTRACT FROM AUTHOR]

The new Schiff bases with D-π-A system were synthesized by the reaction of polycyclic aldehydes and substituted benzothiazoles. The structures of the synthesized Schiff bases (7a and 9a) were determined by FT-IR, ¹H- -NMR, 13C-NMR, ESI-Mass and elemental analyses. The optical properties of the new compounds were investigated and the optical band gaps (Eg) were calculated by the Tauc method using the UV--Vis absorption spectra. Density functional theory (DFT/B3LYP/6-31G(d,p)) calculations were conducted to get more insight on the structural and electronic properties of novel Schiff bases. The optimized molecular geometry, UV--Vis spectroscopic parameters and HOMO--LUMO energies were examined and the calculated results were compared with experimental data. [ABSTRACT FROM AUTHOR]

The composition of the water-extractable organic matter (WEOM) of sedimented soils, namely, dark-humus water-accumulative stratozems (Fluvic Chernic Phaeozems (Loamic, Pachic)) in the nonplowed bottom of a dry valley is studied and compared to the WEOM composition of arable soils (Haplic Chernozems and Fluvic Chernic Phaeozems (Loamic, Pachic)) on the adjacent cropland of a small catchment. The WEOM composition of stratozems is examined layer by layer from the surface to the depth of 120 cm with a step of 20 cm. Water extracts are analyzed for organic carbon, nitrogen, and pH. The optical properties of WEOM are analyzed by spectrophotometry and fluorescence spectroscopy and compared in these soil types. The specific features of the changes in the properties of stratozems with the depth are also analyzed. The erosion and accumulation processes are shown to considerably influence the composition of soil WEOM. However, the content of dissolved carbon in WEOM does not significantly differ either between arable chernozems and sediments or down along the vertical profiles of the sediments on dry valley bottom. In turn, the content of nitrogen in the WEOM of arable chernozems is generally higher as compared with that in sediments, where it predictably decreases with depth. Presumably, the decrease in the nitrogen content of WEOM in sediments with depth is associated with its uptake by plant roots and an increase with depth in the share of anaerobic zones, with their activated denitrification processes. The top 0–60-cm soil layer in sediments actively retains the nutrients leached from arable soils, primarily, dissolved nitrogen. This process promotes the carbon accumulation in the underlying layers. An increase in the content of total organic carbon in Fluvic Chernic Phaeozem (Loamic, Pachic) layers below 60 cm is explainable with the accumulation of the dissolved organic matter migrating downward. On the one hand, the dissolved organic matter is sorbed by soil and, on the other hand, is preserved as a result of a decrease in the microbial activity caused by the deficiency in nutrients. [ABSTRACT FROM AUTHOR]

The identification and quantification of caffeine is a common need in the food and pharmaceutical industries and lately also in the field of environmental science. For that purpose, Raman spectroscopy has been used as an analytical technique, but the interpretation of the spectra requires reliable and accurate computational protocols, especially as regards the Resonance Raman (RR) variant. Herein, caffeine solutions are sampled using Molecular Dynamics simulations. Upon quantification of the strength of the non-covalent intermolecular interactions such as hydrogen bonding between caffeine and water, UV-Vis, Raman, and RR spectra are computed. The results provide general insights into the hydrogen bonding role in mediating the Raman spectral signals of caffeine in aqueous solution. Also, by analyzing the dependence of RR enhancement on the absorption spectrum of caffeine, it is proposed that the sensitivity of the RR technique could be exploited at excitation wavelengths moderately far from 266 nm, yet achieving very low detection limits in the quantification caffeine content. [ABSTRACT FROM AUTHOR]

Indene was polymerized to polyindene (PI) through a cationic mechanism using TiCl4•2THF complex as initiator. The cationic mechanism was investigated through electronic absorption spectroscopy and either the indanyl cation as well as the polyindenyl cation absorption bands were distinguished and assigned. The PI structure was investigated through the indane model compound and the indene reference compound electronic absorption spectra. Furthermore, the Raman spectrum of PI was recorded for the first time and the complete Raman and FT-IR absorption bands of PI are reported with the assignment of the main bands. The glass transition (Tg) of cationic, radiation-induced and thermally initiated PI were measured through DSC and the corresponding molecular weight estimated. DSC and TGA-FTIR analysis were used to study the thermal decomposition of PI. It was assessed that PI is pyrolyzed back into indene monomer in almost theoretical yield with an activation enthalpy of E# = 164 kJ/mol while the decomposition enthalpy of PI was determined at 101.6 kJ/mol a value very close to the theoretical value of 108.9 kJ/mol. It was assessed that PI is a fully recyclable polymer which could be decomposed back to the monomer and re-polymerized at will. [ABSTRACT FROM AUTHOR]

K Zr 2 PO 4 3 : xEu 3 + Nanophosphors with varying molar percentages (0.5, 1, 2, 3, 4, and 5 mol. %) are synthesized using a urea-assisted solution combustion synthesis approach. The phosphors exhibit crystallization in a rhombohedral phase, namely in the R 3 ¯ c space group with the help of X-ray diffraction. The anionic group of (PO4)3− is responsible for all the vibrations occurring in the FTIR spectra. The photoluminescence characteristics of K Zr 2 PO 4 3 : xEu 3 + (x = 0.5 – 5 mol. %) are examined when excited at a wavelength of 392 nm, resulting in the prominent emission at 613 nm. At a concentration of 2 mol. %, the optimal concentration is observed, and the emission tone of the phosphor is centered in the reddish part of the color gamut, with a high color purity of 92%. It is observed that the synthesized phosphor has a branching ratio more than 50%, indicating a possible laser emission transition. The band gap energy of K Zr 2 PO 4 3 : Eu 3 + is found via diffuse reflectance measurements and found to be 4.19 eV. The value of metallization criteria is less than unity which dictates the non-metallic nature of the synthesized phosphors. These results indicate that this phosphor is very suitable for use in solid-state lighting applications as a red light-emitting phosphor. [ABSTRACT FROM AUTHOR]

A comprehensive study has been carried out to understand the details of structural modifications of polyallyl diglycol carbonate (PADC) polymer under the effects of different external factors. Synergistic effect of heat treatment with radiation on the polymer structure was studied. Incorporation of a neutral chromophore to understand the structural changes was attempted. Theoretical simulations were applied to get insight into the detailed aspects of structural modifications. Diverse techniques were used to characterize the samples and compare with the results of simulation studies. [ABSTRACT FROM AUTHOR]

In this present work, Fe2O3 nanoparticles doped with different concentrations of aluminium oxide (Al2O3) (5%, 10%, and 20%) were synthesized by the modified co-precipitation method, and samples were calcined at 600 oC for a fixed duration 2 hours. The calcined samples were examined through X-ray diffraction (XRD) techniques and results reveal that rhombohedral crystalline structures were confirmed for all calcined samples and the crystallite size of the particle increased from 42.2 nm to 60.5 nm i.e. crystallite size increases with increase of in dopant concentration alumina in Fe2Al2O6-δ samples. The infrared spectroscopic results reveal that, as usual, peaks of hydroxyl group vibrations were found in band formation at about 3000 cm-1, 1650 cm-1 and the sharp peaks at 610, 614, and 617 cm-1 were attributed to O-Fe-O molecules vibrations whereas, 533 cm-1 were attributed by O-Al-O molecules vibrations. The optical band gap was calculated via tauc plot and calculated values show an inverse trend of 2.19 to 2.15 eV with an increase in dopant concentration alumina. Vibrating sample magnetometer (VSM) were used to analyze the magnetic characteristics of calcined samples and the results reveal that saturation magnetization is highest for dopant alumina 10% concentration (Ms = 50.6×10-2 emu/g) and coercivity is highest for dopant alumina 5% concentration (Hc = 875.38Oe) respectively among all the calcined samples. [ABSTRACT FROM AUTHOR]

This study examines the impact of thermal annealing on ZnO nanorods produced by vapour phase transport. Nanorods were annealed at temperatures of 300, 500, and 700 °C. It has been demonstrated through X-ray diffraction that the annealing process led to an increase in crystalline size from 34 to 51 nm, indicating improved crystallinity. The optical bandgap decreased from 3.28 to 3.22 eV as a result of defect minimization during annealing. Due to increased crystallinity and fewer defects, annealing increased the dark conductivity from 0.8 to 2 S/cm, as shown by electrical experiments. After annealing, the photosensitivity increased from 10 to 35 and the responsivity rose from 0.18 to 0.48 A/W. The quantitative results demonstrate that annealing modifies the physical properties of ZnO nanorods and improves their photodetection capabilities. [ABSTRACT FROM AUTHOR]

Dissolved organic matter is the most mobile part of soil organic matter; however, its change and transformation occurring during soil erosion are insufficiently studied. We assess the optical properties of water-extractable organic matter (WEOM) in arable soils with different degrees of degradation caused by erosion and sedimentation in a small arable catchment in the Kursk oblast, namely, the WEOM of arable Haplic Chernozems (noneroded and moderately eroded) and their analog with soil matter sedimentation, Fluvic Chernic Phaeosem (Loamic, Pachic). WEOM is isolated from the aggregates of 2–1 mm and >10 mm. In water extracts, the contents of organic carbon and nitrogen were measured. Optical properties were assessed according to absorption spectra and three-dimensional fluorescence spectra. The eroded and aggraded soils emerge to be similar to each other but significantly differ from noneroded chernozem in terms of the main quantitative characteristics of soil organic matter—the content of organic carbon and nitrogen, and pH. However, both the quantitative and qualitative WEOM characteristics show a different trend: the WEOM of Fluvic Chernic Phaeosem (Loamic, Pachic) significantly differs from eroded and moderately eroded Haplic Chernozems. In addition, some characteristics of WEOM (nitrogen content, SUVA254, S350–400, and SR) depend on the size of the aggregates from which WEOM is isolated (2–1 or >10 mm). The fluorescent properties of WEOM also depend on the size of the aggregates. Our data suggest that the properties of the WEOM in a small arable catchment of the central forest-steppe zone are variable and are largely determined by the destruction of water-unstable aggregates and consolidation of their particles, as well as by the leaching of dissolved organic matter. When aggregates are destroyed by water, their particles migrate with flows along the slope, and organic matter is decomposed. However, particles accumulate in depressions to become consolidated into blocky structural units, while the properties of soil WEOM are significantly altered, both due to degradation of organic matter and as a result of its leaching. [ABSTRACT FROM AUTHOR]

Spectroscopic studies (FT-IR, Raman, 1H, and 13C NMR, UV-VIS) of caffeic acid (CFA) and its conjugates, i.e., caftaric acid (CTA), cichoric acid (CA), and cynarin (CY), were carried out. The antioxidant activity of these compounds was determined by a superoxide dismutase (SOD) activity assay and the hydroxyl radical (HO•) inhibition assay. The cytotoxicity of these compounds was performed on DLD-1 cell lines. The molecules were theoretically modeled using the B3LYP-6-311++G(d,p) method. Aromaticity indexes (HOMA, I6, BAC, Aj), HOMO and LUMO orbital energies and reactivity descriptors, NBO electron charge distribution, EPS electrostatic potential maps, and theoretical IR and NMR spectra were calculated for the optimized model systems. The structural features of these compounds were discussed in terms of their biological activities. [ABSTRACT FROM AUTHOR]

The manuscript presents the optical properties of directly deposited films of gold nanoparticles (AuNPs) prepared by the Ultrasonic Spray Pyrolysis (USP) technology. Four samples were produced, with AuNP deposition times on the glass substrate of 15 min, 30 min, 1 h and 4 h. The morphological characterisation of the deposited films showed that the size of the first deposited AuNPs was between 10 and 30 nm, while, with a longer duration of the deposition process, larger clusters of AuNPs grew by coalescence and aggregation. The prepared layers were characterised optically with Ultraviolet–visible spectroscopy (UV–vis) and ellipsometry. The ellipsometric measurements showed an increasingly denser and thicker effective thickness of the AuNP layers. The extinction spectra displayed a clear local surface plasmonic resonance (LSPR) signature (peak 520–540 nm), indicating the presence of isolated particles in all the samples. For all AuNP layers, the imaginary part of the parallel and perpendicular components of the anisotropic dielectric function was dominated by a central peak at around 2.2 eV, corresponding to the LSPR of isolated particles, and a high-energy shoulder due to Au interband transitions. It was shown that, as the density of particles increased, the extinction cross-section grew over the whole spectral range where measurements are taken. Thus, the response can be explained with an enhanced electromagnetic response between the AuNPs that can be connected to the increase in particle density, but also by the formation of clusters and irregular structures. [ABSTRACT FROM AUTHOR]

Context: Xanthates are organic compounds of great interest in coordination chemistry due to their different basic sites, which allow them to form complexes with different coordination modes and geometries. These compounds are relevant in the environment and act as heavy metal collectors in aqueous environments. In this theoretical–experimental work, electronic spectroscopy studies of n-propyl xanthate complexes with group 12 metals were performed. This study verified structural differences in these systems, depending on the environment in which they are inserted. In addition, structural differences were observed when the solid was changed to an n-hexane solution. Thus, it was observed that the complexes assume a mononuclear structure in solution, while they present a polymeric form in the solid phase. The electronic spectra obtained through TD-DFT calculations were compared to those of the previously synthesized complexes. In the final theoretical analysis, the main orbitals involved in these transitions were assigned using population analysis calculations. The synthesis of the complexes was confirmed through infrared (MID and FAR), UV‒Vis, Raman, and NMR-1H spectroscopic analyses. Methods: The structures of the mononuclear and polymeric complexes were optimized in vacuum and n-hexane. Under vacuum, DFT levels M06L/6–311 + + G** + LANL2TZ and M06L/def2-TZVP were used for the mononuclear complexes, and M06L/LANL2DZ + LANL2 were used for the polymer complexes. For the calculations of the mononuclear complexes in n-hexane, the same level of theory was used for the solid state. TD-DFT calculations for 300 excited states were performed with the same levels of theory and used the optimized structures of the complexes. Furthermore, population analysis was carried out on all the systems studied. Gaussian 09 software was used for the structure optimization, TD-DFT, and population analysis calculations. GaussSum software was used to evaluate the molecular orbitals and electronic spectra. [ABSTRACT FROM AUTHOR]

The purpose of this work was to prove the enrichment of sunflower oil with active principles (polyphenolic acids, flavones, flavonoids) from plants, using the ultrasounds-assisted extraction (UAE) process. The analytical technique used for qualitative characterization of the UAE samples is thin layer chromatography (TLC), a relatively simple technique, which under certain separation and detection conditions highlights the bioactive components of the plants studied in our study. UV-VIS spectrophotometry was used to evaluate the level of flavonoids. The UAE samples in sunflower oil were also characterized by determining the alpha-tocopherol content through a gas-cromatographic method (GC-MS), and by evaluating the antioxidant activity through an indirect DPPH spectrophotometric method. The oily plants extracts were obtained to be used as raw material in the formulation of a dermato-cosmetic product, and thus the characterisation performed herein is very useful in supporting the effects of the above-mentioned products. [ABSTRACT FROM AUTHOR]

We report synthesis of PVA capped CdS/ZnS (Cadmium Sulphide/Zinc Sulphide) core/shell nanocomposites using a simple and cost effective chemical precipitation method. The synthesized samples were characterized using different characterization techniques. Results of UV-vis and PL spectroscopic analysis indicate formation of nanoparticles of CdS and CdS/ZnS whereas the XRD patterns show formation of cubic and hexagonal structure of CdS and ZnS Nanoparticles respectively. Results of TEM and SEM analysis show that, the synthesized Nanoparticles are more or less spherical in shape. The FTIR result confirms the formation of Cd-S and Zn-S bond in the CdS/ZnS core/shell structures. Results of photocatalytic study indicates that the CdS/ZnS core/shell nanocomposites shows excellent photocatalytic activity for the degradation of Methyl Orange (MO) where it was degraded nearly 83% under UV irradiation. [ABSTRACT FROM AUTHOR]

The widespread use of nonlinear optical (NLO) materials for contemporary technologies has sparked intense interest in their production with the creation of materials with a continuous endeavor. In this theoretical study, we investigate the NLO responses of doped superalkali (SA) metal salts with planar boron sheets (PBSs). We consider four different substrates (B10, B10F3, B16, and B16F3) to create 12 new surfaces ( 1-12) by doping SAs (Li2F, Li2OF, Li2O2) with them. We optimize the geometries of these surfaces and analyze their frontier molecular orbitals (FMOs) and natural bond orbitals (NBO) to obtain insights into their global chemical reactivity. We also examined their NLO responses ranging as 1.22–1.67×10−21, 3.39–7.59×10−24, and 3.5×10−24e.s.u. Our results reveal that the doped surfaces exhibit stronger NLO responses compared to the undoped surfaces, and that the strongest NLO response is found in the B16F3-doped surface. The role of various segments in FMOs is investigated using the TDOS and PDOS spectral analyses. To comprehend the relationship between the SA and the B10F3 substrates molecule more effectively, non-covalent interaction (NCI) investigation is carried out. Additionally, Time-dependent DFT (TD-DFT) simulations are done for UV–Vis analysis to observe significant redshifts up to 1050nm. All the SA-doped surfaces are thermodynamically stable NLO materials with improved NLO responses, so these materials are proposed to be used during the construction of advanced NLO responses. [ABSTRACT FROM AUTHOR]

Some spectroscopic and electronic properties of the bioactive compound were presented using density functional theory (DFT), by depending on Gaussian software and Gauss view 6.0 using the DFT/B3LYP method with 3 - 21G (d, p) basis set. This research concerns the spectroscopic and electronic properties of the 2-ethyl-4-thioamideo pyridine (ETP) compound and UV-Vis and IR are thoroughly studied. The low energy gap between high occupied molecular orbital (HOMO) and low unoccupied molecular orbital (LUMO) led to an increase in charge transfer. It was found that the energy gap was 0.14719 eV, and this is due to the calculated band gap decreasing with the formation of charge transfer, which is because of hydrogen bonding between the Several formations. The HOMO-LUMO the calculation presents the fact of electron density transfer. Therefore, The separation energy between HOMO and LUMO is represented as the kinetic stability and also an indicator of the reactivity of the compound. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride (PVC) is the most widely product used in a range of industrial and commercial applications due to its high chemical resistance, properties, and low cost. Thin films of polyvinyl chloride were produced using a casting process. Cobalt (60Co) source and radiation doses of (1, 5, 10, 15, and 20) kGy were used for gamma irradiation. According to the X-ray diffraction (XRD) results, the PVC films had an amorphous structure. Before irradiation, the surface PVC did not have a porous structure, but after irradiation, porous PVC formed, according to field emission scanning electron microscopy (FESEM) photographs. The polymer chains exposed to gamma radiation showed no structural alterations according to the Fourier-transform infrared spectrometer FTIR measurements. The effect of radiation on optical characteristics was determined using the UV-VIS spectrophotometer. The results demonstrate that the absorption spectrum increases, and transmission decreases with the increase in the dose of irradiation and indicated that indirect transition was allowed and the energy gap of PVC films decreased when irradiated with a radiation dose from (4.95 eV -- 4.48 eV). The purpose of gamma irradiation is to improve the specifications and properties of the polymer for use in other application areas. [ABSTRACT FROM AUTHOR]

Boronate esters are a class of compounds containing a boron atom bonded to two oxygen atoms in an ester group, often being used as precursors in the synthesis of other materials. The characterization of the structure and properties of esters is usually carried out by UV-visible, infrared, and nuclear magnetic resonance (NMR) spectroscopic techniques. With the aim to better understand our experimental data, in this article, the density functional theory (DFT) is used to analyze the UV-visible and infrared spectra, as well as the isotropic shielding and chemical shifts of the hydrogen atoms 1H, carbon 13C and boron 11B in the compound 4-(4,4,5,5-tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde. Furthermore, this study considers the change in its electronic and spectroscopic properties of this particular ester, when its boron atom is coordinated with a fluoride anion. The calculations were carried out using the LSDA and B3LYP functionals in Gaussian-16, and PBE in CASTEP. The results show that the B3LYP functional gives the best approximation to the experimental data. The formation of a coordinated covalent B–F bond highlights the remarkable sensitivity of the NMR chemical shifts of carbon, oxygen, and boron atoms and their surroundings. Furthermore, this bond also highlights the changes in the electron transitions bands n → π* and π → π* during the absorption and emission of a photon in the UV-vis, and in the stretching bands of the C=C bonds, and bending of BO2 in the infrared spectrum. This study not only contributes to the understanding of the properties of boronate esters but also provides important information on the interactions and responses optoelectronic of the compound when is bonded to a fluorine atom. [ABSTRACT FROM AUTHOR]

Molybdenum Trioxide nanoparticle (MoO3-NPs) was introduced to Cellulose acetate (CA) biopolymer with different concentration using casting process by dispersed MoO3-NPs [0.0, 0.25, 0.5 and 1.0 wt%]. Molecular structure of samples has been studied using XRD and UV–Vis. the data shown by X-ray results indicated the amorphous nature of the pure polymer. Some peaks are appeared as a result of the addition of MoO3-NPs which indicate that samples were partially crystallized. The crystallite size of nano-metal oxide was calculated for blended samples by Size–Strain Plot method which was found to increase with increasing the concentration of MoO3. UV–Vis results indicate that there exist two indirect energy band gaps; Onset band gap which observed to decreases from 1.3 eV for pure polymer to 0.78 eV for polymer blended with 1.0 wt% MoO3-NPs and HOMO–LOMO band gap which observed to decrease from 3.23 eV for pure polymer to 2.89 eV for polymer blended with 1.0 wt% MoO3-NPs. This indicate that the addition of nano-metal oxide improve the optical conduction of CA. Urbach energy was observed to increase with increasing MoO3-NPs from 0.27 eV for pure CA to 0.32 eV for 1.0 wt% MoO3-NPs concentration which may be occurred due to the creation localized states at the band gap as a result of the addition of MoO3-Nps. [ABSTRACT FROM AUTHOR]