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Great efforts are constantly being made by industry-specific coffee agencies to standardize the certification of coffee quality. In consequence, international trade requires quick and reliable analyses because of their high cost, the risk of misclassification, the difficulty of large-scale analysis, and, most importantly, the subjectivity generated by tasters. A powerful analytical method that can be used to accurately evaluate and identify coffee varieties is Laser-Induced Breakdown Spectroscopy (LIBS). In this study, it provided a quick, cost-effective, and residue-free method commonly used in laboratories for direct analysis, determining multi-elemental composition, and exploring the organic composition of roasted coffee. The mineral composition of eight varieties of pure roasted coffee was determined using a pulsed nanosecond laser produced from a Nd:YAG laser at 1064 nm. The most important spectral variables for coffee variety identification were sequestered using LIBS coupled with a chemometric-tool-based principal component analysis (PCA). The nine main wavelengths chosen corresponded to the elements of C(I), Mg(II, I), Ca(II), Fe(I), K(I), H(I), and O(I), in addition to the CN group. The overall findings indicated that using LIBS to identify coffee varieties is feasible based on a simple, quick, and eco-friendly strategy without the requirement for complex preparation or wasting time in preparation. Such studies can help to protect the coffee market and businesses by certifying product quality. Using LIBS and full statistical illustrations with PCA, the prevention of unfair competition, protection of consumers, and determination of coffee quality can be achieved. [ABSTRACT FROM AUTHOR]

The high-quality n-type CdS on a p-type Si (111) photodetector device was prepared for the first time by a one-pot method based on an ns laser ablation method in a liquid medium. Cadmium target was ablated in DMSO solution, containing sulfur precursor, and stirred, assisting in 1D-growth, to create the sulfide structure as CdS nano-ropes form, followed by depositing on the Si-substrate by spin coating. The morphological, structural, and optical characteristics of the CdS structure were examined using X-ray diffraction, transmission, and scanning electron microscopy, photoluminescence, and UV-VIS spectroscopy. From X-ray diffraction analysis, the growing CdS spheres have a good crystal nature, with a high purity and desired c-axis orientation along the (002) plane, and the crystallinity was around 30 nm. According to optical characterization, high transparency was found in the visible–near-infrared areas of the electromagnetic spectrum, and the CdS spheres have a direct optical energy band gap of 3.2 eV. After that, the CdS/Si hetero-structured device was found to be improved remarkably after adding CdS. It showed that the forward current is constantly linear, while the dark current is around 4.5 µA. Up to a bias voltage of 4 V, there was no breakdown, and the reverse current of the heterojunctions somewhat increased with reverse bias voltage, while the photocurrent reached up to 580 and 690 µA for using 15 and 30 W/cm2 light power, respectively. Additionally, the ideal factors for CdS/Si heterojunction were 3.1 and 3.3 for 15 and 30 W/cm2 light power, respectively. These results exhibited high performance compared to the same heterojunction produced by other techniques. In addition, this opens the route for obtaining more enhancements of these values based on the changing use of sulfide structures in the heterojunction formation. [ABSTRACT FROM AUTHOR]

This study focused on identifying the effect of the laser wavelengths used in cleaning some manifestation damage appearing in pigments used on archaeological cartonnage preserved in the Egyptian Museum, Egypt. The manifestations of damage appear as mud, resin, color, dust and microbiological damage stains. Lasers were chosen as one of the modern applications that give good results when cleaning the pigment materials without making direct contact with the material. Accordingly, lasers with a wavelength of 532 and 1064 nm were tested to identify their effect on stains caused by pigments and to choose the best one for use in cases similar to those materials in the future. This study was conducted to identify the effect of the selected wavelengths and choose the best ones to apply to the archaeological model. The evaluations were conducted using several tests and analyses, such as digital microscopy, X-ray florescence, Fourier transform infrared spectroscopy, and Handy colorimetry to evaluate that effect of lasers with a wavelength of 532 and 1064 nm to remove stains. The experimental study demonstrated the good effect of the Nd:YAG laser with a wavelength of 1064 nm compared with that of the 532 nm laser. The results of using the Nd:YAG laser proved the good effect of removing all stains compared with the 532 nm laser, which caused big changes when used to clean the stains on the pigment's surfaces; it also did not help in removing or reducing some stains such as mud stains. According to these results, the good effect of the Nd:YAG laser (1064 nm) make it more suitable for cleaning than that of the Nd:YAG laser (532 nm), which is not recommended for use as it gave bad results when applied. [ABSTRACT FROM AUTHOR]

A polymeric nanocomposite film, composed of PMMA/PVDF and different amounts of CuO NPs, was successfully prepared using the casting method to enhance its electrical conductivity. Various techniques were employed to investigate their physicochemical properties. The addition of CuO NPs causes a noticeable difference in the intensities and locations of vibrational peaks in all bands, confirming the incorporation of CuO NPs inside the PVDF/PMMA. In addition, the broadening of the peak at 2θ = 20.6° becomes more intense with increasing amounts of CuO NPs, confirming the increase in the amorphous characteristic of PMMA/PVDF incorporated with CuO NPs in comparison with PMMA/PVDF. Furthermore, the image of the polymeric structure exhibits a smoother shape and interconnection of pore structure associated with spherical particles that agglomerate and give rise to a web-like organization that becomes a matrix. Increasing surface roughness is responsible for an increasing surface area. Moreover, the addition of CuO NPs in the PMMA/PVDF leads to a decrease in the energy band gap, and further increasing the additional amounts of CuO NPs causes the generation of localized states between the valence and conduction bands. Furthermore, the dielectric investigation shows an increase in the dielectric constant, dielectric loss, and electric conductivity, which may be an indication of an increase in the degree of disorder that confines the movement of charge carriers and demonstrates the creation of an interconnected percolating chain, enhancing its conductivity values compared with that without the incorporation of a matrix. [ABSTRACT FROM AUTHOR]

The present article is based on Silver (Ag) doped Lead sulfide (PbS) nanoparticles for optoelectronic applications. Structural and morphological properties of pristine PbS and 0.5, 1.0, 2.5 and 5.0 wt% Ag doped PbS nanoparticles (NPs) were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. X-ray diffraction (XRD) patterns of pure PbS, 0.5, 1.0, and 2.5 wt% Ag: PbS NPs were marginally shifted towards a lower diffraction angle and XRD profile of 5.0 wt% Ag: PbS NPs was shifted to the right side with respect to JCPDS card. The crystallite sizes of pristine PbS and Ag: PbS NPs were obtained in the range of 17–18.7 nm. The phase and substitution of Ag into the PbS lattice were confirmed by the Fourier transform (FT) Raman spectra of Ag:PbS NPs. Scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) spectroscopy was employed to observe the morphology and to confirm the homogeneous doping of pristine PbS and Ag-doped PbS NPs. The optical band gaps were determined in the range of 3.011–3.378 eV and 1.201–1.286 eV, respectively from diffused reflectance spectra of pristine PbS and Ag: PbS NPs. Urbach energies were evaluated as 1.5687, 1.8879, 2.8020, 1.6425, and 1.2799 eV from the slopes of the fitted straight lines near the absorption band edge region of pure, 0.5, 1.0, 2.5, and 5.0 wt %, respectively. Current (I)-voltage (V) characteristics of the prepared NPs were carried out in the presence of an applied voltage (±4 V). The enhancement in I–V characteristics of 2.5 and 5.0 wt % was caused by the increment in the injected charge density. The optical transition states were examined by the second-order derivative of the absorbance spectra. The high carrier density in Ag: PbS has been attributed to the bottleneck effect, which is confirmed by the BM shift and I–V characteristics. It was found that Ag: PbS NPs exhibited an increase in electrical properties compared to the pristine PbS NPs. • Novel Ag doped PbS nanoparticles synthesis has been achieved facilely at low temperature i.e. 60 °C by chemical route. • All synthesized Ag doped PbS samples possess cubic crystal structure confirmed by XRD and Rietveld refinement studies. • Vibrational spectroscopy and EDX/SEM e-mapping studies confirm the synthesis of PbS at all Ag contents. • Energy gap was found to be improved for Ag doped PbS NPs compare to bulk. • Improved physical properties are observed in Ag doped PbS NPs compare to pure. [ABSTRACT FROM AUTHOR]

In recent years, laser-induced breakdown spectroscopy (LIBS) technique showed its promising for material analysis, quality control, forensic science, and environmental safety monitoring. Besides, due to its rapid measurement capability and minimal sample-preparation requirements, it is a widely recognized elemental analysis approach used in a variety of study domains. The current work compares spatially resolved single (SP) and double pulse (DP), especially orthogonal DP, setups for LIBS to examine and enhance the limit of detection (LOD) in duplex stainless steels alloy. Using the Boltzmann plot method and the Stark broadening mechanism, the electron temperature and density of local arc plasma are highlighted due to single pulse and orthogonal pre-pulse double pulse configurations. With delay time, the circumstances of arc plasma's local thermodynamic equilibrium (LTE) of emission spectral lines are investigated. The experimental results show that there are significant increases in the spectral intensities of the Fe lines in double pulse LIBS under Ar-gas compared to those under He-gas. Internal standardization was used to create calibration curves for the spectral lines of Cr, Cu, and Mn in the alloy sample for the both studied media. It demonstrated that argon outperforms helium in determining the elemental composition of steel alloys. Furthermore, LOD for SP-LIBS and DP-LIBS in both media were calculated, which showed a higher detection LOD for DP-LIBS in the presence of Ar-gas compared to that in He-gas. • The LIBS single and double pulse emission spectrum of aluminum-based alloys is investigated in various gas media (Ar and He). • The Stark broadening mechanism and Boltzmann plot method highlight local arc plasma electron density and temperature. • Delay time investigates arc plasma's local thermodynamic equilibrium (LTE) of emission spectral lines. • Internal Standardization calibration curves for Cr, Cu, and Mn were applied to steel alloy samples in both media. • SP- and DP-LIBS LODs were calculated in both media. [ABSTRACT FROM AUTHOR]

In the present article, the pure PbS and different concentrations of Gd doped PbS (Gd:PbS) films were developed using the spray pyrolysis route by growing thin films on the glass substrate. The estimated crystallite sizes were found from 15.5 to 20.8 nm for as-deposited films. The spherical shape morphology of grains was observed by FESEM. The obtained average grain sizes varied from 52.8 to 108.2 nm were obtained from the grain size distributions for 0.0, 0.5, 1.5, and 2.5 wt % Gd: PbS films, respectively. Extinction coefficients of as-deposited films were measured from 0.04 to 0.12 in the range of wavelength 200–2500 nm. Refractive indices of films were obtained from 5.4 to 1.22 in range of 200–2500 nm wavelength. The band gaps of 2.75, 2.64, 2.45, and 3.10 eV for 0.0, 0.5, 1.0 and 2.5 wt % Gd thin films were estimated using Tauc's relation respectively. The values of the dielectric constant, dielectric loss, and optical conductivity were recorded in the range of 1.32–29.6, 0.30–0.61, and 2.34 × 1014–3.08 × 1013 between 200 and 2500 nm wavelengths for as-deposited thin films respectively. The optimum values of linear susceptibility, non-linear susceptibility and refractive index were recorded in the range of 1.23–2.93, 5.21 × 10−10 - 120 × 10−10, 3.54 × 10−9 – 74.2 × 10−9 (esu) between 1.46 and 0.52 eV respectively for as-deposited thin films. The Gd: PbS thin films improve the physical properties and therefore, it becomes suitable candidature for the applications in optoelectronic devices. • Fabrication of PbS and Gd:PbS films on glass by nebulizer spray pyrolysis is reported. • Spherical grains with highly packed structure of PbS and Gd:PbS thin films. • Homogeneous doping of Gd in ZnO was detected by EDX/SEM mapping. • The band gaps is noticed in range of 2.45–3.10 eV for PbS and Gd:PbS thin films. • Values of linear/non-linear susceptibilities, and non-linear refractive index of Gd: PbS decreases as compared to pure. [ABSTRACT FROM AUTHOR]

Many different applications make use of carbide nanoparticles, which could be prepared via conventional techniques, but all of these techniques tend to be intricate, and several steps must be completed before fabrication can begin. However, in this study, we present, for the first time, a straightforward technique for the production of zinc carbide nanoparticles (ZnC) through the use of nanosecond laser ablation of a zinc target immersed in hexane with the assistance of a purged nitrogen gas. We conducted optical absorption spectroscopy on the produced nanostructured materials. We studied the optical properties using the conventional method of the Tauc relation. We compared these values with various innovative approaches, including the absorption spectrum fitting method (ASF) and its derivative method (DASF). We conducted an investigation into each approach's correction to achieve a satisfactory level of agreement between the values, and documented a comparable pattern. These results help us understand the physicochemical properties of zinc carbide and other nanoparticles or nanocomposites that do not have any chemical residues. They make them a possible candidate to improve luminescence catalytic activity, photonics, and optoelectronic applications. • Zinc carbide synthesized via pulsed laser ablation in liquid media. • Zinc carbide nanoparticles have high distribution without using any surfactant. • The optical properties of the prepared materials were investigated via different methods. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticle/multi-walled carbon nanotube composites (Fe 3 O 4 /MWCNTs) were prepared using femtosecond pulsed laser ablation of iron target immersed in functionalized MWCNTs by facile one-pot synthesis of pulsed laser ablation in liquid environmental for catalytic degradation of 4-ntrophenol from aqueous solution. The easily obtained magnetic nanocomposites were systematically characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). According to XRD, magnetite is the magnetic phase that has formed. A network of MWCNTs is seen in the FESEM image, together with nano‑iron oxides. Raman spectroscopy revealed that the reduction of the sp2 bond domains due to the strong contacts between iron oxide and MWCNT increased the D/G ratio, which may lead to structural distortions in the nanotubes. From FT-IR, the presence of new peaks in the finger print region related to Fe-O-Fe in Fe 3 O 4 , indicates that Fe3O4 has been successfully loaded onto the surface of MWCNTs. In addition, the prepared magnetic nanocomposite showed outstanding catalytic reduction activity for 4-NP when compared to MWCNTs and Fe 3 O 4. The results demonstrated that the prepared nanocomposite could be a promising nanocatalyst for the catalytic reduction of 4-NP. The straightforward, speedy, and dependable Fe 3 O 4 /MWCNTs-based approach was found to be a possibly relevant technology for the targeted removal of pollutants and the treatment of wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

The pure Nickel oxide (NiO) nanoparticles (NPs) and Mg doped NiO (Mg:NiO) were prepared by one pot-auto combustion process in the presence of citric acid. Phase identification of Mg: NiO NPs was carried out by X-ray diffraction (XRD) and FT-Raman spectroscopy. The values of crystallite sizes 20.5, 20.1 19.8, 20.0, and 19.2 nm and lattice strains 1.225 x10−4, 1.473x 10−4, 0.977x 10−4, 1.597x 10−4,and 0.742x10−4 have been evaluated using Williamson-Hall plots analysis of the prepared NPs. Spherical shape morphology of Mg:NiO NPs was observed by FESEM images. The average particle size distributions were evaluated as 48.4, 60.8, 28.0, 33.4, and 35.3 nm for 0.0, 1.0, 2.0, 3.0 and 5.0 wt% Mg: NiO NPs, respectively. The presence of chemical elements, and their stoichiometric amount in prepared Mg:NiO NPs were determined by EDAX. The oxidation states Ni (2P 3/2), Ni (2P 1/2), O (1s), and Mg (2s) were recorded by X-ray photoelectron spectroscopy (XPS). Kubelka-Munk (K-M) function was employed to determine the optical band gaps of the prepared NPs by recording diffuse reflectance spectroscopy (DRS). The energy gaps of 3.538, 3.535, 3.487, 3.532, and 3.490 eV were estimated for 0.0, 1.0, 2.0, 3.0, and 5.0 wt% Mg: NiO, respectively. Methylene blue (MB) dye solution was employed to investigate the photocatalytic activity of as-prepared NPs in the presence of UV light. The degradation of MB was examined using visible photo application of pure NiO and Mg: NiO NPs. The 3 wt% Mg:NiO photocatalyst degrades the MB dye up to 98% after 75 min under UV light irradiation. Photocatalytic degradation of 3 wt% Mg:NiO NPs results showed that the NiO NPs are potential photocatalysts in the degradation of MB dye and can be utilized in wastewater treatment. • Novel Mg doped NiO NPs synthesis via one pot auto-combustion process is reported. • Monophasic synthesis Mg:NiO NPs was noticed and XPS provides chemical composition. • Energy gaps of NiO NPs were decreased from 3.53 to 3.48 eV with Mg concentrations. • A remarkable enhancement in photocatalytic activity was observed for Mg:NiO NPs. • Stability, elemental trapping and degradation mechanism studies are also reported. [ABSTRACT FROM AUTHOR]

A nanosecond solid-state laser was employed to perform nanocomposite structure from multi-walled carbon nanotubes (MWCNTs) decorated with nickel oxide nanoparticles (NiO NPs) in a single one-step for optoelectronic applications. The preparation was carried out by pulsed laser ablation method, followed by investigation the physicochemical properties via various techniques. Then, the nonlinear characteristics were measured using a Z-scan approach: nonlinear absorption coefficient (β), nonlinear refractive index (n 2), and 3rd nonlinear optical susceptibility (χ3). It was determined that as the intensity of the incident lase beam rised, the values of β gradually droped. Also, the study showed that the nonlinearity of NiO NPs/MWCNTs nanocomposite was significantly improved in compared with inividual MWCNTs and NiO NPs as after the decoration with NiO NPs, the taken time for electrons to transport and photons to transition was incrased, leading to an improvment in the nonlinear optical properties of the nanocomposite. These results provide this simple method for decorating MWCNTs by NiO NPs to produce nanocomposite material with outstanding nonlinear optical characteristics to be applicable in the optical devices like optical switches and optical sensors. • The β, n 2 , and x3 of MWCNTs doped NiO NPs are estimated. • The sign of the nonlinear reflective index of NiO NPs/MWCTs is negative. • NiO-MWCNTs nanocomposite was synthesized by ablation of Ni target in f-MWCNTs • The produced nanocomposite has high distribution without using any surfactant. • The nanocomposites were synthesized via simple one-pot green method [ABSTRACT FROM AUTHOR]