Plasma Emission Research Articles

Removal of Cochineal Dye Color through Atmospheric Pressure Plasma Discharge Jet

The extensive utilization of dyes across diverse industries has resulted in environmental pollution, leading to the degradation of water bodies. To prevent environmental contamination, the use of eco-friendly dyes and innovative processes for dye degradation is crucial. This study aimed to investigate the color removal process of cochineal dye (Dactylopius coccus Costa) using the atmospheric pressure plasma jet (APPJ: Atmospheric Pressure Plasma Jet) technique. The dye extracted from the cochineal insect was treated with APPJ and the resulting color removal process was analyzed. Optical emission spectroscopy (OES) was used to investigate the plasma emission lines, and UV-Vis spectroscopy was used to monitor the color removal process. The results revealed that the decolorization of cochineal dye was a result of an oxidative degradation process caused by the interaction of the reactive species (NO3− and NO2−) generated by the APPJ plasma discharge with the dye molecules. This color removal process occurs in an acidic medium, leading to a pH change from 5.4 to 2.7. These pH changes can be attributed to fluctuations in the concentrations of reactive species such as nitrates and nitrites in the liquid phase. UV-Vis spectroscopy measurements showed that 90% of the cochineal color was removed within the first 10 min of treatment. This study enhances our understanding of natural color removal and provides insights into its mechanism, opening up possibilities for controlled modification and applications in various fields.

Fabrication of TiN coatings using superimposed HiPIMS and MF technique: Effect of target poisoning ratios and MF/HiPIMS pulse on-time ratio

The commercial application of high power impulse magnetron sputtering (HiPIMS) is hindered by its low deposition rate in thin film and coating industries. This study proposes an effective method to enhance the deposition rate of TiN films by superimposing middle-frequency (MF) pulses during the off-time of HiPIMS pulsing. The impact of Ti target poisoning ratios (ranging from 30 % to 70 %) controlled by the plasma emission monitoring (PEM) feedback control system and MF/HiPIMS pulse on-time ratios (ranging from 1.5 to 24) on the structural, morphological, and mechanical properties of thin films was investigated. Increasing the target poisoning ratio and the ratio of MF/HiPIMS on-time pulses up to 6 resulted in increased peak current and peak power density of HiPIMS for the superimposed TiN films. Compared to TiN films grown solely using HiPIMS, all the superimposed TiN films exhibited improved deposition rates ranging from 3.89 to 6.36 nm/kW·min. Analysis of crystallographic and chemical composition confirmed the formation of single-phase stoichiometric TiN films with a smooth columnar microstructure. The TiN film grown at a 60 % target poisoning ratio and an MF/HiPIMS pulse on-time ratio of 1.5 displayed the highest hardness of 34.4 GPa and elastic modulus of 485 GPa, surpassing the values obtained for pure HiPIMS-grown, MF-grown, and DC-grown films. Moreover, TiN film deposited at target poisoning ratios of 50 % and a 6 times MF/HiPIMS pulse on-time ratio exhibited a high hardness of 30.3 GPa and a high deposition rate of 5.94 nm/min/kW, which was 2.15 times higher than that of pure HiPIMS. Additionally, the formation of stoichiometric TiN films led to relatively lower electrical resistivity. Overall, the superimposition of HiPIMS and MF pulses presents a promising approach to overcome the limitations of HiPIMS and enhance the deposition rate of TiN films. The findings of this study highlight the potential of TiN films grown by the superimposed HiPIMS-MF and PEM feedback control technique for various industrial applications.

High-harmonic Plasma Emission Induced by Electron Beams in Weakly Magnetized Plasmas

Electromagnetic radiation at higher harmonics of the plasma frequency (ω ∼ n ω pe, n > 2) has been occasionally observed in type II and type III solar radio bursts, yet the underlying mechanism remains undetermined. Here we present two-dimensional fully kinetic electromagnetic particle-in-cell simulations with high spectral resolution to investigate the beam-driven plasma emission process in weakly magnetized plasmas of typical coronal conditions. We focused on the generation mechanisms of high-harmonic emission. We found that a larger beam velocity (u d ) favors the generation of the higher-harmonic emission. The emissions grow later for higher harmonics and decrease in intensity by ∼2 orders of magnitude for each jump of the harmonic number. The second and third harmonic (H2 and H3) emissions get closer in intensity with larger u d . We also show that (1) the H3 emission is mainly generated via the coalescence of the H2 emission with the Langmuir waves, i.e., H2 + L → H3, wherein the coalescence with the forward-propagating beam-Langmuir wave leads to the forward-propagating H3, and coalescence with the backward-propagating Langmuir wave leads to the backward-propagating H3; and (2) the H4 emission mainly arises from the coalescence of the H3 emission with the forward- (backward-)propagating Langmuir wave, in terms of H3 + L → H4.

Packing thickness dependent plasma emission induced by laser ablating thin-layer microgranular materials

Exponential dependence of plasma emission with packing thickness implying the existence of a well-defined threshold for the presence and absence of thickness effect.

GEOCHEMISTRY AND PETROGRAPHY OF METAMORPHIC SOLE AMPHIBOLITES FROM THE SLATINA QUARRY, MT. ZRINSKA GORA, CROATIA

The investigated Mt. Zrinska Gora amphibolites are a part of the metamorphic sole of the Banovina ophiolite complex. Mineral composition and other petrographic characteristics of amphibolites and adjacent peridotite were investigated by polarised microscopy and chemical analyses of rocks were obtained by a combination of inductively coupled plasma mass and emission spectrometry. The main minerals in these garnet-bearing amphibolites are amphibole and plagioclase with accessory garnet, sphene, spinel, opaque mineral ± clinopyroxene ± quartz ± actinolite ± zoisite-clinozoisite ± prehnite ± pumpelyite and ± clay minerals. Kelyphitic corona is developed around garnet. The amphibolites have nematoblastic, nematogranoblastic, porphyroblastic and porphyroclastic textures and homogenous to foliated structures. The presence of clinopyroxene in some of the investigated amphibolites points to their possible formation under P‒T conditions of upper amphibolite facies. The greenschist facies retrograde metamorphism and subsequent surface weathering of amphibolites is also evident. The chemical composition of rocks indicates that protoliths of most amphibolites were tholeiitic basalts, initially formed in island arcs and the adjoining back-arc basins. During the intraoceanic subduction in Jurassic Neotethys Ocean basalts/basaltic tuffs of island arc tholeiite affinity and back-arc basin basalts, positioned on the top of the down-going oceanic slab, were welded to the base of the hot over-riding mantle wedge, metamorphosed to amphibolite rocks and obducted together with ophiolites on the Adria continental margine. The new described amphibolite type having peridotite protolith characteristics originated as the consequence of the hydration of the bottom part of the overlying mantle wedge.

Synergy enhancement and signal uncertainty of magnetic-spatial confinement in fiber-optic laser-induced breakdown spectroscopy

The synergy enhancement of magnetic-spatial confinement using a bar magnet pair was applied to fiber-optic laser-induced breakdown spectroscopy (FO-LIBS).

Wild almond (amygdalus nana l.) Oil physical and chemical indicators, fatty acids and the study of element components

The wild almond (Amygdalus nana L.) seeds from the Nurota district in the Navoi region of the mountains have been used, and the extraction of the seed oil was established using the cold-pressing method. The main physical-chemical indicators of the oil were defined. The composition of the oil, including the induction of the oil and argon plasma emissions, as well as the fatty acid components, were studied using chromatographic and spectrometric methods, and elemental analysis was carried out. The macroelements (Ca, Na, Al, P, K) and micronutrients (Fe, Cu, Zn, Se, Mn, Co, Ni) present in the oil composition were determined. Additionally, a microbiological purity assessment and a quantitative analysis of the heavy metals present in the oil content were conducted.

Differences in Genomic Alterations and Accumulations of Heavy Metals Between Advanced Non-small Cell Lung Cancer Patients with and without Bone Metastasis.

Purpose: Bone metastasis (BoM) has been closely associated with increased morbidity and poor survival outcomes in patients with non-small cell lung cancer (NSCLC). Given its significant implications, this study aimed to systematically compare the biological characteristics between advanced NSCLC patients with and without BoM. Methods: In this study, the genomic alterations from the tumor tissue DNA of 42 advanced NSCLC patients without BoM and 67 patients with BoM and were analyzed by a next-generation sequencing (NGS) panel. The serum concentrations of 18 heavy metals were detected by inductively coupled plasma emission spectrometry (ICP-MS). Results: A total of 157 somatic mutations across 18 mutated genes and 105 somatic mutations spanning 16 mutant genes were identified in 61 out of 67 (91.05%) patients with BoM and 37 of 42 (88.10%) patients without BoM, respectively. Among these mutated genes, NTRK1, FGFR1, ERBB4, NTRK3, and FGFR2 stood out exclusively in patients with BoM, whereas BRAF, GNAS, and AKT1 manifested solely in those without BoM. Moreover, both co-occurring sets of genes and mutually exclusive sets of genes in patients with BoM were different from those in patients without BoM. In addition, the serum concentrations of Cu and Sr in patients with BoM were significantly higher than in patients without BoM. One of our aims was to explore how these heavy metals associated with BoM interacted with other heavy metals, and significant positive correlations were observed between Cu and Co, between Cu and Cr, between Sr and Ba, and between Sr and Ni in patients with BoM. Given the significant impacts of molecular characteristics on patients' prognosis, we also observed a noteworthy negative correlation between EGFR mutations and Co, alongside a significant positive correlation between TP53 mutations and Cd. Conclusions: The genomic alterations, somatic interactions, key signaling pathways, functional biological information, and accumulations of serum heavy metals were markedly different between advanced NSCLC patients with and without BoM, and certain heavy metals (e.g., Cu, Sr) might have potentials to identify high-risk patients with BoM.

Filament induced breakdown spectroscopy with enhanced excitations from plasma gratings

The interaction of two or three filaments generates a plasma grating, with a focus lens collecting the plasma emission into a spectrometer from the side direction after plasma grating ablating the sample.

DETERMINAÇÃO E DISTRIBUIÇÃO DE Cu, Fe E Zn EM CAMAPU POR ICP-OES

DETERMINATION AND DISTRIBUTION OF Cu, Fe, AND Zn IN CAMAPU BY ICP-OES. This study aimed to determine the total contents of copper, iron, and zinc in camapu and protein fractions by inductively coupled plasma emission spectrometry. Firstly, lipid removal was performed using chloroform and methanol (2:1). Protein fractions were obtained after sequential extraction using four extractors (water, 0.5 mol L-1 sodium chloride, 50% acetic acid v v-1 and 0.05 mol L-1 sodium hydroxide). The camapu sample and protein fractions were digested in a cavity-microwave oven with diluted nitric acid and hydrogen peroxide. The accuracy of the procedure was evaluated using the addition and recovery method in the digests and protein extracts. All the elements were determined in the protein fractions. Levels of Cu, Fe, and Zn ranged from 0.07 to 0.5 mg kg-1 were found in the lipid fraction. The residue presented higher iron content compared to other elements. Higher Cu and Zn contents were found associated with albumin. All elements studied were found in the protein fractions, and the total protein concentration determined in each protein fraction was 5.74 mg kg-1 (albumins), 0.28 mg kg-1 (globulins), 4.46 mg kg-1 (glutelins 1) and 0.46 mg kg-1 (glutelins 2).

Solid substrate assisted enhanced laser induced breakdown spectroscopy for metal element analysis in aqueous solution.

Due to plasma quenching caused by the dense water medium, laser-induced breakdown spectroscopy (LIBS) faces challenges such as strong continuous background radiation and weak and broadened characteristic spectral lines when directly detecting metal elements in liquids. In this work, we introduced a simple approach to improve underwater LIBS signals with a solid substrate-assisted method, which requires no sample pre-treatment and simple operation and thus has potential for in situ marine applications. In this method, four submerged solid substrates (Zn, Cu, Ni, and Si) were employed to investigate the breakdown characteristics of underwater LIBS and the mechanism of spectral enhancement by using a CaCl2 solution. The results demonstrated a significant improvement in the detection sensitivity of Ca with these substrates even at a short laser pulse with a relatively low laser energy (10 mJ). Among them, the semiconductor Si substrate exhibited the best enhancement effect, with an enhancement factor of over 75 for the Ca ionic lines at 393.4 nm and 396.8 nm and an enhancement factor of 29 for the Ca atomic line at 422.7 nm, respectively. This is mainly because the presence of substrate decreases the breakdown threshold of the liquid sample, and a higher plasma excitation temperature and electron density are obtained, which, in turn, leads to higher signal intensity. Furthermore, significant plasma emission enhancements for a wide range of elements are also achieved from seawater. These findings can contribute to the development of compact underwater in situ LIBS sensors with low power consumption, while ensuring high detection sensitivity.

Enhancement of Antioxidative and Anti-Inflammatory Activities of Corn Silk Polysaccharides After Selenium Modification.

This study aimed to study the effect of selenium modification on the bioactivity of corn silk polysaccharides, particularly its antioxidant and anti-inflammatory functions. HNO3-NaSeO3 was used to selenize degraded corn silk polysaccharides (DCSP). The structure and physicochemical properties of DCSP and selenized corn silk polysaccharides (Se-DCSP) were characterized by inductively coupled plasma emission spectroscopy, Fourier-transform infrared, ultraviolet-visible spectroscopy, nuclear magnetic resonance, nanometer, scanning electron microscopy, and thermogravimetric analysis. The protective effects of DCSP and Se-DCSP on HK-2 cells damaged by nano-calcium oxalate and the changes of inflammatory factors were detected by laser confocal microscopy, flow cytometry, and fluorescence microscopy. The selenium content of DCSP and Se-DCSP were 19.5 and 1226.7μg/g, respectively. Compared with DCSP, Se-DCSP showed significantly improved biological activity, including the scavenging ability of various free radicals (increased by about 2-3 times), the intracellular reactive oxygen content (decreased by about 1.5 times), and the mitochondrial membrane potential (decreased by about 2.5 times). Moreover, cell viability and morphological recovery ability were improved. Compared with DCSP, Se-DCSP significantly down-regulated HK-2 cell inflammatory factors MCP-1 (about 1.7 times), NLRP3, and NO (about 1.5 times). The antioxidant activity and the ability to down-regulate the expression of inflammatory factors of Se-DCSP were significantly enhanced compared with DCSP, and Se-DCSP can better protect HK-2 cells from oxidative damage, indicating that Se-DCSP has a stronger potential ability to inhibit kidney stone formation.

Non-Gaussian Signal Statistics’ Impact on LIBS Analysis

A detailed study has been carried out to reveal signal statistics’ impact on analysis sensitivity in laser-induced breakdown spectroscopy (LIBS) measurements. For several signals measured simultaneously, it was demonstrated that space-, spectra- and time-integrated plasma emission followed a normal distribution while the spectra- and time-resolved LIBS signal (atomic line intensity, plasma background emissions) distribution functions were biased compared to a Gaussian distribution function. For the first time in LIBS, the impact of a non-Gaussian distribution function on the limit of detection (LOD)’s determination has been studied in detail for single-shot spectra as well as for averaged spectra. Here, we demonstrated that the non-symmetrical distribution of the LIBS signals influenced the estimated LODs, so knowledge of a LIBS signal’s distribution function provides more reliable results, and the analysis sensitivity can be wrongly estimated if Gaussian distribution is presumed.

Diopside-like based ceramics prepared via one-step sintering of extracted titanium slag and coal fly ash

Diopside-Like based ceramics as the main crystalline phase (expressed as ‘Diopside’) were prepared via one-step sintering using extracted titanium slag (ETS) and coal fly ash (CFA) as raw materials. The effects of CFA content and sintering temperature on the crystal phase composition, microstructure, properties and crystallization kinetics were studied by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, and inductively coupled plasma emission spectrometry. According to the findings, the addition of CFA supplemented the deficiency of Si and Al in ETS and balanced the Ca/Al/Si molar ratio in the system. Moreover, at the CFA doping of 20 %, melilite was gradually transformed into ‘diopside’ at 800–1100 °C that further remained stable at 1160–1200 °C. ‘Despite’ the fact that the crystallization activation energy increased and the Avrami index was at its lowest level (1.75), the crystallization temperature was reduced, whereas the crystallization rate increased, causing the ceramic body and surface to crystallize and thereby improving the properties of ceramics. Sintering at 1180 °C for 1 h resulted in ceramics with ‘diopside’ as the primary crystal phase composition. The water absorption, linear shrinkage, bulk density, bending strength, and acid resistance were respectively 1.3 %, 13 %, 2.89 g cm−3, 141.8 MPa, and 97.36 %. Finally, ‘diopside’ possessed the higher acid resistance than melilite and anorthite.

Assessment of contamination and potential ecological risks of heavy metals in riverine sediments from gold mining and pristine areas in Ghana

This study explore the characteristics of heavy metal pollution, contamination levels, and potential ecological risks in riverine sediments found in both gold mining and pristine areas. Such investigations are vital for the ongoing monitoring and preservation of water bodies and overall ecosystem health. In total, 44 composite sediment samples were collected from seven pristine environments and four mining sites. These samples underwent preparation, digestion, and analysis for heavy metal content, utilizing the inductively coupled plasma emission mass spectrometer (ICP-MS). Various tools and models, including the geo-accumulation index, enrichment factor, and degree of contamination, were employed to assess the impact of pollution on the environment. Modified ecological risk index were also used to evaluate potential ecological risks. The average concentrations of heavy metals in pristine sites spanned from 0.01±0.01 (Cd) to 73,753.64 ± 388.15 mgkg−1 (Fe), while in mining sites, they ranged from 0.04±0.02 (Cd) to 56,394.25±400.66 mgkg−1 (Fe). Comparing these concentrations against the USEPA Ecological Screening Values, Mean Shales levels, and the Canadian ISQG, it became evident that Pb, Cd, Zn, Ni, Co, and Mn concentrations generally remained below the recommended guideline values in both pristine and mining areas. However, concentrations of Cr, As, Cu, and Hg exceeded the prescribed threshold limits, particularly in the mining regions. Through Principal Component Analysis (PCA) and Geometrical Analysis for Interactive Aid (GAIA) modeling, two primary sources of heavy metals were identified: anthropogenic-related and geogenic-related. GAIA and PCA together explained 78.53 % and 79.40 % of the total variability in heavy metal concentrations, respectively. Overall, the pollution and ecological risk assessment indicated low to moderate contamination levels, with a notable exception of high arsenic contamination in the Nyam river. The findings of this study hold significance for assessing sediment conditions and river quality in mining communities within Ghana and globally. They also provide empirical data to recommend measures for mitigating water contamination in such communities.

The Effect of heat and Storage Duration on Physicochemical Properties of Plastic Bottled Water at Sharq El Nile Locality in Khartoum State, Sudan

The physicochemical properties of plastic bottled water were studied using the Inductively Coupled Plasma Emission Spectroscopy Technique (ICPE) before and after heating and storage duration. One sample was taken from Al Byara Well - Block (39) in Sharq El Nile Locality, Sudan at fall season in 2019.This sample was exposed to sunlight in plastic bottled for (50 days) and stored for (40 days). Before heating and storage duration, various macro and micro minerals such as (Sulfur, Calcium, Potassium, Magnesium, Sodium, Copper, Silicon, Manganese, and Zinc) have been detected with different concentrations at ((0.0057, 0.170,0.003, 0.390, 0.089, 0.016, 0.085,0.0014,and 0.00057) ) respectively. The concentrations some toxic and radioactive elements including (Cadmium, Holmium, Thallium, Barium, Scandium, and Strontium) were also appeared with various concentrations at ((1.3,1.5,27,0.62,0.31,and 0.77) ) consecutively. These results may return to the location of sample, and vital activities. After heating and storage duration, concentrations of macro and micro minerals above were changed to (0.0047,0.190, 0.0026, 0.093, 0.072, 0.014,0. 067, 0.00, and 0.00) ) respectively. However, two new micro minerals which called (Iodine and Boron) was found with concentration at ((0.0095 and 0.00060) successively. Moreover, the concentrations of some toxic and radioactive elements above were modified to (1.1,0.00,24,0.65,0.23,and 0.96) ) successively, and three new toxic elements like (Mercury, Nickle, and Antimony) were existed with concentrations at ((1.1,3.7,and 6.9) ) respectively. These results may be attributed to the interaction between water and plastic and storage period. However, the results before and after heating and storage duration were discovered within background values except for (Thallium). Keywords: Inductively Coupled Plasma Emission Spectroscopy, Concentration, Sunlight, Drinking Water, Plastic Bottled.

FERROCENE DISPROPORTIONATION REACTIONS IN A PLASMA-LIQUID SYSTEM WITH A ROTATING GLIDING DISCHARGE

A plasma-liquid system with the activation of H2O distillate and 0.1 M ferrocene solution in organic solvents (ethanol, acetonitrile) with a rotating gliding discharge plasma was studied. The research was conducted using various plasma-forming gases (air, Ar, N2, CO2). Determination of plasma parameters was performed by plasma emission spectroscopy methods. It was shown that the plasma of both the rotating gliding discharge and the plasma of the secondary discharge supported by the gliding discharge are non-isothermal. The study of the physicochemical properties of the synthesis products was performed by adsorption, luminescence analysis, polarimetry, chromatographymass spectrometry and NMR methods. It was found that cyclopentadiene ligands of ferrocene disproportionate into saturated cyclic hydrocarbons (cyclopentane and pentane). Also, as a result of plasma chemical synthesis, aromatic compounds (benzene and its derivatives) are formed.

Vortex-assisted hydrophobic natural deep eutectic solvent liquid-liquid microextraction for the removal of silver ions from environmental water.

This study presents a novel approach for the quantification of silver ions in environmental water through the utilization of liquid-liquid microextraction, employing natural deep eutectic solvents in conjunction with inductively coupled plasma emission spectroscopy. The extracted solvent was characterized by Fourier transform infrared spectroscopy (FT-IR). The impact of various extractant types, extractant molar ratio, extractant volume, extraction time, and salt concentration on the efficacy of silver ion extraction was investigated. The findings indicate that the optimal extraction efficiency was attained by utilizing a 5-mL aqueous solution volume, containing 1000 μL thymol/lactic acid NADES 1:3, a salt concentration of 1 mg mL-1, a pH value of 4, and a vortex time of 4 min. Upon implementing the optimized experimental conditions, the recovery of target metal ions was from 96.9 to 101.0%. The relative standard deviations were observed to be within the range of 1.5 to 2.7%. The present study demonstrates the reproducibility, accuracy, and reliability of the method for detecting silver ions in environmental water, with linear range of 5~1000 ng mL-1 and limits of detection (LOD) and limits of quantification (LOQ) of 1.52 ng mL-1 and 5.02 ng mL-1, respectively.

Estimating the yield stress of soft materials via laser-induced breakdown spectroscopy

Taking three typical soft samples prepared respectively by loose packings of 77-, 95-, and 109-μm copper grains as examples, we perform an experiment to investigate the energy-dependent laser-induced breakdown spectroscopy (LIBS) of soft materials. We discovered a reversal phenomenon in the trend of energy dependence of plasma emission intensity: increasing initially and then decreasing separated by a well-defined critical energy. The trend reversal is attributed to the laser-induced recoil pressure at the critical energy just matching the sample’s yield strength. As a result, a one-to-one correspondence can be well established between the samples’ yield stress and the critical energy that is easily obtainable from LIBS measurements. This allows us to propose an innovative method for estimating the yield stress of soft materials via LIBS with attractive advantages including in-situ remote detection, real-time data collection, and minimal destructive to sample.

THE STUDY OF X-RAY SPECTRUM OF COMA GALAXY CLUSTER

The X-ray spectrum of the Coma galaxy cluster was studied using the data from the XMM-Newton observatory. We combined 7 observations performed with the MOS camera of XMM-Newton in the 40′ × 40′ region centered at the Coma cluster. The analyzed observations were performed in 2000–2005 and have a total duration of 196 ksec. We focus on the analysis of the MOS camera spectra due to their lower affection by strong instrumental line-like background. The obtained spectrum was fitted with a model including contributions from the Solar system/Milky Way hot plasma and a power law X-ray background. The contribution of the instrumental background was modeled as a power law (not convolved with the effective area) and a number of Gaussian lines. The contribution from the Coma cluster was modeled with a single-temperature hot plasma emission. In addition, we searched for possible non-thermal radiation present in the vicinity of the center of the Coma cluster, originating e.g. from synchrotron emission of relativistic electrons on a turbulent magnetic field. We compared the results with previous works by other authors and spectra obtained from other instruments that operate in the similar energy range of 1−10 keV. Careful and detailed spectrum analysis shall be a necessary contribution to our future work – searching for axion-like dark matter particles’ manifestations in the Coma cluster.