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Mass spectrometry-based proteomics is widely applied to human blood serum or plasma in the search of biomarkers for various diseases. However, the enormous complexity and dynamic range of protein concentrations in these samples render a significant analytical challenge, particularly for detecting low-abundance candidate biomarkers. As a result, strategies for enriching low-abundance proteins and improving their identification in serum or plasma proteomics are commonly used. Here, we describe an immunodepletion technique that is routinely used in our lab for removing high-abundance proteins from human serum/plasma., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Capillary electrophoresis coupled to mass spectrometry (CE-MS) has emerged as a powerful analytical technique with significant implications for clinical research and diagnostics. The integration of information from CE and MS strengthens confidence in the identification of compounds present in clinical samples. The ability of CE to separate molecules based on their electrophoretic mobility coupled to MS enables the accurate identification and quantification of analytes, even in complex biological matrices such as human plasma.Here, we present a detailed protocol for an untargeted metabolomics study using CE-MS and its application in a study on human plasma from patients suffering Long COVID syndrome. The protocol ranges from sample preparation to biological interpretation, detailing a workflow enabling the analysis of cationic and anionic compounds, metabolite identification, and data processing., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: To investigate the pharmacokinetics (PK) of ceftazidime-avibactam (CAZ-AVI) in critically ill patients undergoing continuous venovenous hemodiafiltration (CVVHDF), and compare with a general phase III trial population., Methods: A prospective PK study was conducted in critically ill patients who received CVVHDF for acute kidney injury, treated with CAZ-AVI (1000/250 mg or 2000/500 mg q8h). Plasma and CVVHDF-circuit samples were collected to determine CAZ-AVI concentrations. Individual PK parameters at steady-state were estimated using non-compartmental analysis. For visual comparison, plasma concentrations from CVVHDF patients were overlaid with simulated data from patients not receiving CVVHDF based on previously developed population PK models., Results: A total of 35 plasma samples and 16 CVVHDF-circuit samples were obtained from four patients, with two patients sampled on two separate occasions. Median total clearance and volume of distribution were 4.54 L/h and 73.2 L for CAZ and 10.5 L/h and 102 L for AVI, respectively. Median contribution of CVVHDF to total clearance was 19.8% for CAZ and 5.3% for AVI. Observed CAZ-AVI PK profiles were generally within the 90% confidence interval of model predictions, but the observed concentrations were notably lower early (0-2 h) and higher later (4-8 h) in the dosing interval, suggesting a higher volume of distribution., Conclusions: These results suggest that the CAZ-AVI dose regimens used in this study can be applicable in critically ill patients undergoing CVVHDF, despite the different shape of the PK profiles observed in this population. Further research with a larger patient cohort is warranted to validate and refine these findings., Competing Interests: Declaration of competing interest H.G. has received speaker honoraria from Pfizer and MSD. I.K. has received speaker honoraria from Pfizer. Menarini and bioMérieux. All other authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Hemolysis is the most prevalent pre-analytical interfering factor and a major source of error in laboratory analysis. The examination of samples post-centrifugation can provide valuable information regarding pre-analytical interferences. In this unusual case, a patient's plasma specimen was cherry-red after centrifugation, which is most usually indicative of hemolysis. However, subsequent investigations ruled out common hemolysis causes. We eventually determined that the patient's cherry-red plasma was most likely caused by other factors in the patient's medical history, including cancer treatment with PV-10 (rose bengal disodium 10%). We then conducted an interference study to comprehensively assess the effects of PV-10 on various biochemical tests, especially liver function tests and bilirubin levels. The findings indicate that PV-10 has varying effects on different biochemical assays and test results should be examined individually. This report underlines the need for awareness of potential drug interference on laboratory tests for better result interpretation and making clinical decisions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Using Fourier Transform Infrared spectroscopy (FTIR), it is possible to show chemical composition of materials and / or profile chemical changes occurring in tissues, cells, and body fluids during onset and progression of diseases. For diagnostic application, the use of blood would be the most appropriate in biospectroscopy studies since, (i) it is easily accessible and, (ii) enables frequent analyses of biochemical changes occurring in pathological states. At present, different studies have investigated potential of serum, plasma and sputum being alternative biofluids for lung cancer detection using FTIR. However, until now, it has not been shown which biofluid; among serum and plasma, that can serve as the best material medium for detecting lung cancer with highest levels of accuracy. In this study, plasma and serum isolated from blood consenting participants without lung cancer symptoms (controls) and lung cancer patients. The samples were measured using FTIR and subsequently analyzed by machine learning (ML) algorithms in order to show which fluids (serum or plasma) would better enhance detection of lung cancer. Higher absorbances values of PO 2- , CH 2 , CH 3 and amides vibrations in FTIR spectra of both serum and plasma samples, collected from lung cancer patients were observed in comparison to individuals without lung cancer symptoms (controls). Principal component analysis (PCA) of FTIR spectra showed plasma and serum samples collected from lung cancer patients and individuals without lung cancer symptoms were better differentiated in fingerprinting region (from 800 to 1800 cm - 1 ) when compared to lipid region (2800-3000 cm - 1 ). Moreover, also sensitivity specificity and accuracy calculated by logistic regression (LR) and receive operating characteristic (ROC) showed higher values for fingerprint range (800-1800 cm - 1 ) in comparison with lipids (2800-3000 cm - 1 ) one for both, serum and plasma. However, using these methods differences between serum and plasma were not existed. From the all obtained results, it was visible, that both fluids could be used in detected lung cancer using FTIR. Moreover, it was also showed that fingerprint range gave a better distinction between the studied patient groups than the lipid range. This was noticeable for both serum and plasma., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Green ammonia synthesis using fluctuating renewable energy supply in decentralized process is a goal that has been long sought after. Ammonia synthesis with non-thermal plasma under mild conditions is a promising technology, but it faces the critical challenge of low energy efficiency. Herein, we develop an easily-scalable AuCu3/Cu catalyst, which consists of a decimeter-scale metallic Cu antenna and nano-scale AuCu3 catalytic sites on metallic Cu surface, significantly enhancing the energy efficiency and ammonia yield in a radio-frequency (RF) plasma system. Compared to plasma alone, the single-pass ammonia yield over AuCu3/Cu increases by a factor of 20, approaching 10%. Mechanistic studies indicate that Cu antenna can amplify the millimeter-scale local electric field, thereby facilitating the generation of active nitrogen species, including nitrogen radicals and vibration-excited nitrogen molecules. Due to the downshifted d-band center and unique Cu-Au interface structure, the AuCu3 nanoalloy modified on Cu antenna surface significantly reduces hydrogenation barriers of active NHX (x=0,1,2) species (the rate-determining step) and facilitates ammonia desorption at lower temperature. The synergistic effect of Cu antenna and surface AuCu3 nanoalloy comprehensively enhances ammonia synthesis through both the nitrogen radical-mediated Eley-Rideal pathway and the vibration-excited nitrogen molecule-mediated Langmuir-Hinshelwood pathway., (© 2024 Wiley‐VCH GmbH.)

Despite notable advances in anticancer drug development, their manufacture and use pose environmental and health risks due to toxic byproducts, drug residue contamination, and cytotoxicity to normal cells. Therefore, developing cost-effective anticancer treatments with fewer toxic side effects and higher selectivity is essential to the advancement of highly effective anticancer therapies. Plasma-activated water (PAW) offers a green alternative to conventional chemical treatments as it reverts to water within days. However, the limited duration and dose of reactive oxygen and nitrogen species (RONS) in acidified PAW restrict its clinical deployment and the full understanding of their mechanism. In this study, we propose alkaline PAW as an innovative enhancement of the RONS technology. The alkaline PAW generated markedly superior RONS, with about 10 times higher levels of NO 2 - , H 2 O 2 , and ONOO - /O 2 •- than acidic PAW. The possible RONS generation pathways in alkaline PAW are analyzed by scavengers. In conventional acidic PAW, 70% of the H 2 O 2 concentration is contributed by • OH but only about 20% in alkaline PAW. ONOO - is mainly formed through the reaction of O 2 •- with NO in alkaline pH, while in acidic PAW, it mainly forms from NO 2 - and H 2 O 2 . The results unveiled the synergistic and formidable anticancer effects of alkaline PAW against cancer cells, typified by an increase in intracellular ROS/RNS levels. Furthermore, alkaline PAW injection also effectively prevented xenograft tumor growth in mice. We systematically investigated this high-dose anticancer solution without using noble gases, toxic reagents, or extra energy consumption and successfully demonstrated the possibility of alkaline PAW being an effective and environmentally friendly therapeutic technology. The activity is closely linked to the RONS dose, and the generation pathway provides much-needed insight into the fundamental aspects of PAW chemistry required for the optimization of the biochemical activity of PAW.

Objectives: In most countries the majority of patients are in outpatient care. In difference to hospitalized patients, their blood samples often take hours after collection to centrifugation. The study investigates the release of potassium and the development of pseudohyperkalemia in lithium heparin (Li-Hep) and serum blood collection tubes over time., Methods: From 201 donors 4 serum and 4 Li-Hep blood collection tubes were taken each. After 0.5, 4, 6 and 8h whole blood was centrifuged, and potassium levels were determined. To simulate the preanalytic conditions, the samples with a storage time >0.5h were shaken on a standard shaker for 1h and stored at 4-8°C for the remaining time., Results: Over time, significant more potassium was released before centrifugation from the Li-Hep plasma than from serum (1.21 vs 0.94 mmol/L). After 6h, the two groups were no longer highly statistically significantly different (potassium mean: 5.01 mmol/L in serum group, 4.92 mmol/L in Li-Hep group). In the Li-Hep group 164 donors developed a pseudohyperkalemia after 8h, compared to 76 in the serum group., Significance: The decision as to which material is best suited should not only be based on which value comes closest to the physiological situation immediately after blood collection. The subsequent preanalytic circumstances must also be considered. Serum tubes appear to be at least as suitable for potassium determination as Li-Hep tubes. In terms of patient blood management, serum provides the possibility of performing a wider range of analyses in the outpatient setting., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Reuter et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The complex dynamics of protein expression in plasma during hyperacute HIV-1 infection and its relation to acute retroviral syndrome, viral control, and disease progression are largely unknown. Here, we quantify 1293 blood plasma proteins from 157 longitudinally linked plasma samples collected before, during, and after hyperacute HIV-1 infection of 54 participants from four sub-Saharan African countries. Six distinct longitudinal expression profiles are identified, of which four demonstrate a consistent decrease in protein levels following HIV-1 infection. Proteins involved in inflammatory responses, immune regulation, and cell motility are significantly altered during the transition from pre-infection to one month post-infection. Specifically, decreased ZYX and SCGB1A1 levels, and increased LILRA3 levels are associated with increased risk of acute retroviral syndrome; increased NAPA and RAN levels, and decreased ITIH4 levels with viral control; and increased HPN, PRKCB, and ITGB3 levels with increased risk of disease progression. Overall, this study provides insight into early host responses in hyperacute HIV-1 infection, and present potential biomarkers and mechanisms linked to HIV-1 disease progression and viral load., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Cefiderocol may potentially be used to treat skin and soft tissue infections (SSTIs). However, the pharmacokinetics of cefiderocol in human soft tissues have not yet been determined. The objective of the present PK study was to investigate whether target-site concentrations of cefiderocol are sufficiently high for the treatment of SSTIs., Methods: In this pharmacokinetic study, a single intravenous dose of 2 g cefiderocol was administered to eight healthy male volunteers. Drug concentrations were determined in plasma, muscle and subcutis over 8 h. Free plasma concentrations were calculated using the plasma protein binding determined with ultrafiltration. Free tissue concentrations were obtained using microdialysis. Penetration ratios were calculated as AUC0-8h_free_tissue/AUC0-8h_free_plasma. A population pharmacokinetic model was developed, and the probability of target attainment (PTA) was determined using Monte Carlo simulations., Results: Cefiderocol showed good tissue penetration, with mean penetration ratios ± standard deviation of 0.99 ± 0.33 and 0.92 ± 0.30 for subcutis and muscle, respectively. Cefiderocol pharmacokinetics in plasma were best described with a two-compartment model, and tissue concentrations were described by scaling the tissue concentrations to concentrations in the peripheral compartment of the plasma model. For a thrice-daily regimen with 2 g doses intravenously infused over 3 h, PTA was ≥90% for MIC values up to 4 mg/L, both based on free plasma and soft tissue pharmacokinetics., Conclusions: This study indicates that a dose of 2 g cefiderocol achieves concentrations in plasma considered sufficient for treating relevant bacterial species. Assuming a comparable PK/PD target for soft tissues, sufficiently high concentrations would also be achieved in soft tissues., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)

The development of fibrous polymer scaffolds is highly valuable for applications in tissue engineering. Furthermore, there is an extensive body of literature for chemical methods to produce scaffolds that release nitric oxide. However, these methods often use harsh chemistries and leave behind bulk waste. Alkanolamine low-temperature plasma (LTP) is unexplored and single-step processing to form nitric oxide (NO) releasing constructs is highly desirable. The major question addressed is whether it is possible to achieve single-step processing of spun polyester with alkanolamine plasma to achieve nitric oxide releasing capabilities. Herein we report the experiments, processes, and data that support the claim that it is indeed possible to produce such a bio-functional material for potential biomedical applications, especially in cardiovascular implants. Among the tested alkanolamines, monoethylamine (MEA) plasma treated biomaterial outperformed in comparison with diethanolamine (DEA) and triethanolamine (TEA) in terms of NO release and cellular response., (© 2024 Wiley-VCH GmbH.)

The effectiveness of indirect Intravascular laser irradiation of blood (ILIB) is not fully understood. In this study, we provided a novel experiment that employs metabolomics to investigate the effects of ILIB in women. Twenty-eight volunteers underwent indirect ILIB and had their plasma collected before and after this procedure. The ILIB was applied at the radial artery for 30 min, using low-power photobiomodulation (660 nm), and a power output of 0.1 W. Plasma samples were extracted and analyzed using liquid chromatography-high-resolution mass spectrometry in an untargeted approach. Partial Least Squares Discriminant Analysis revealed 151 molecules with the Variable In Projection score of ≥ 1. From these, 26 were identified. After checking for molecules related to dietary intake, fasting, medication, or part of the human exposome, 15 were affected by ILIB. The abundances of Estradiol 17b-glucuronide 3-sulfate, CAR 14:3, PI 22:6/PGJ2, and CAR 12:1 significantly increased by ILIB, while AcylGlcADG 62:9, Tyrosyl-Glutamine, and CDP-DG 22:3/PGF1 had the contrary effect. ILIB was shown to modulate molecules from different chemical classes, although its impact on plasma metaboloma was minimal. Further research is warranted to fully elucidate the implications of these findings across various metabolic pathways, thus advancing the science surrounding ILIB., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethical approval: This study was conducted by the Helsinki criteria and approved by the Ethics Committee of São Francisco University (Approval Number: 63939422.2.0000.5514). Patient consent: All patients consented to participate in the study, providing their approval for this purpose., (© 2024. The Author(s).)

This study addresses the valorization of duck blood, an underutilized protein-rich by-product from the poultry industry, into bioactive protein hydrolysates with antioxidant and ACE inhibitory properties. Raw and heat-treated duck blood were compared as substrates for enzymatic hydrolysis using Neutrase and Papain. Gel electrophoresis revealed that heat treatment reduced fibrinogen content, while FTIR analysis showed that heat treatment modified the protein structure, increasing β-sheet content from 21.13 % to 34.96 %. Heat-treated duck blood hydrolyzed by Neutrase exhibited superior hydrolysis (9.53 %) and protein recovery (60.28 %) compared to raw blood. Pilot-scale production (1000 L) enhanced hydrolysate yield and maintained bioactive properties. LC-MS/MS analysis identified five novel bioactive peptides derived from the hydrolysate's 4-h simulated gastrointestinal (GI) digestion, with WMHVR demonstrating the highest antioxidant and ACE inhibitory activities. Molecular docking simulations revealed that WMHVR competitively inhibits ACE by binding to the S1, S2, and S' pockets through van der Waals and hydrogen bonding interactions. The GI-hydrolysate and identified peptides maintained bioactivity during simulated GI and blood plasma digestion, with ACE inhibition increasing over time. This research transforms food industry waste into functional protein hydrolysates, offering applications in nutraceuticals and functional foods while promoting sustainable practices through waste protein valorization., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Papungkorn Sangsawad reports financial support was provided by Agricultural Research Funding Agency of Thailand (Public Organization) (grant no. CRP6405031940). Papungkorn Sangsawad reports financial support was provided by Thailand Science Research and Innovation (TSRI), and the National Science, Research, and Innovation Fund (NSRF) (project codes: FF3-303-66-24-11(B)). Papungkorn Sangsawad reports financial support was provided by Full-time Doctoral Researcher (project codes: FtR.66/25/2567). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Point-of-care testing of multiple chronic disease biomarkers is crucial for timely intervention and management of chronic diseases. Here, a "sample-to-answer" microfluidic chip was developed for simultaneous detection of multiple chronic disease biomarkers in whole blood by integrating a plasma separation module. The whole detection process is very convenient, i.e., just add whole blood and get the results. The chip successfully achieved the simultaneous detection of total cholesterol, triglycerides, uric acid, and glucose in undiluted whole blood within 21 min, including 6 min for plasma separation and 15 min for enzymatic chromogenic reactions. Moreover, the sensitivity levels of on-chip detection of chronic disease biomarkers can also meet clinically relevant thresholds. The chip is easy to use and has significant potential to improve home self-management of chronic diseases and enhance healthcare outcomes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Persistent symptoms extending beyond the acute phase of SARS-CoV-2 infection, known as Post-COVID condition (PCC), continue to impact many individuals years after the COVID-19 pandemic began. This highlights an urgent need for a deeper understanding and effective treatments. While significant progress has been made in understanding the acute phase of COVID-19 through omics-based approaches, the proteomic alterations linked to the long-term effects of the infection remain underexplored. This study aims to investigate these proteomic changes and develop a method for stratifying disease severity., Methods: Using Sequential Window Acquisition of All Theoretical Fragment Ion Mass Spectra (SWATH-MS) technology, we performed comprehensive proteomic profiling of blood samples from 65 PCC patients. Both plasma and pellet (cellular components) fractions were analyzed to capture a wide array of proteomic changes associated with PCC., Results: Proteomic profiling revealed distinct differences between symptomatic and asymptomatic PCC patients. In the plasma fraction, symptomatic patients exhibited significant upregulation of proteins involved in coagulation, immune response, oxidative stress, and various metabolic processes, while certain immunoglobulins and proteins involved in cellular stress responses were downregulated. In the pellet fraction, symptomatic patients showed upregulation of proteins related to immune response, coagulation, oxidative stress, and metabolic enzymes, with downregulation observed in components of the complement system, glycolysis enzymes, and cytoskeletal proteins. A key outcome was the development of a novel severity scale based on the concentration of identified proteins, which correlated strongly with the clinical symptoms of PCC. This scale, derived from unsupervised clustering analysis, provides precise quantification of PCC severity, enabling effective patient stratification., Conclusions: The identified proteomic alterations offer valuable insights into the molecular mechanisms underlying PCC, highlighting potential biomarkers and therapeutic targets. This research supports the development of tailored clinical interventions to alleviate persistent symptoms, ultimately enhancing patient outcomes and quality of life. The quantifiable measure of disease severity aids clinicians in understanding the condition in individual patients, facilitating personalized treatment plans and accurate monitoring of disease progression and response to therapy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This document is a corrigendum for an article titled "Coupling plasma physics and chemistry in the PIC model of electric propulsion: application to an air-breathing, low-power Hall thruster." The corrigendum addresses an error in Table 5 of the published article, where the incorrect value of 0.1 mg/s was reported for the Anode Mass flow rate. The correct value is 1.0 mg/s. The authors apologize for the error and state that it does not affect the scientific conclusions of the article. The corrigendum also includes the corrected table and its caption. [Extracted from the article]

In the semiconductor industry, fluorocarbon (FC) plasma is widely used in SiO2 etching, with Ar typically employed in the dilution of the FC plasma due to its cost effectiveness and accessibility. While it has been reported that plasmas with other noble gases, namely Kr and Xe, have distinct physical properties such as electron density and temperature, their implementation into plasma etching has not been sufficiently studied. In this work, we conducted SiO2 etching with FC plasmas diluted with different noble gases, i.e., FC precursors of C4F8 and CH2F2 with Ar, Kr, or Xe, under various gas flow rates of each as well as plasma diagnostics for the process interpretation. We show that Ar, Kr, and Xe gas mixtures depend on the FC precursor flow rate and the pattern width in a significantly different manner and we elucidate these findings based on plasma diagnostic results. The results of this work are expected to offer a practical etching database for diverse applications including plasma process engineering and the development of plasma simulation in the semiconductor industry. [ABSTRACT FROM AUTHOR]

In this paper, we present the results of non-contact measurements of electron density in an inductively coupled chemically active plasma at a pressure of 0.5 Torr. As a plasma-forming gas volatile compounds of halides BF3, SiF4, GeF4 mixed with hydrogen and argon were used. The electron density was determined by direct registration of the phase shift of the probing microwave radiation with a frequency of 58 GHz when passing through a cylindrical plasma layer. The method used makes it possible to increase the accuracy of measurements and level out the effects associated with the scattering and absorption of the useful signal by the plasma. It was experimentally shown that changing the content of argon and hydrogen in the ternary gas mixture (halogenide-hydrogen-argon) affects the electron density value in the discharge. Conclusions were drawn about the role of electron attachment to electronegative atoms and radicals as a mechanism for the loss of electrons in the studied low-pressure discharge in the presence of volatile fluorides. [ABSTRACT FROM AUTHOR]

This work proposes a complete and consistent set of cross sections (CSs) for electron collisions with water molecules to be published in the IST-Lisbon database on LXCat. The set is validated from the comparison between experimental and computed electron swarm parameters. The former are collected from literature while the latter are calculated using a space-homogeneous two-term Boltzmann solver, assuming isotropic scattering in inelastic collisions. Rotational CSs, based on the Born approximation, are optimised by means of the electron swarm analysis technique. Superelastic rotational and vibrational collisions are accounted for in the calculations and found to be particularly important for low-energy electrons interacting with water molecules. The set can be used with codes assuming space-homogeneous conditions, in particular common two-term Boltzmann solvers, ensuring a good agreement with experiments. Therefore, it constitutes an important tool for fast calculations and modelling of complex plasma chemistries. [ABSTRACT FROM AUTHOR]

The synthesis of metal nanoparticles has become a priority for the advancement of nanotechnology. In attempts to create these nanoparticles, several different methods: chemistry, physics, and biology, have all been used. In this study, we report the reduction of cations using argon plasma chemistry to produce nanoparticles of gold (AuNPs), silver (AgNPs), and copper (CuNPs). Although other groups have used plasma-reduction methods to synthesize metal nanoparticles from their cation counterparts, these approaches often require plasma‖liquid state interactions, high temperature, specific combinations of gases, and extended treatment times (>10 minutes), for which only specific cations (noble or non-noble) may be reduced. As a result, we have developed a non-thermal, low-pressure argon-plasma‖solid state approach for the reduction of both noble and non-noble cations. More specifically, when 50 μL droplets of 2 mM solutions of gold(III) chloride, silver nitrate, or copper(II) sulfate are exposed to vacuum, they undergo an evaporation process. As the pressure in the chamber decreases to 220 mTorr, the droplets become completely evaporated, leaving behind a metal precursor. Nucleation and growth studies reveal that when the metal precursors of gold(III) chloride, silver nitrate, and copper(II) sulfate are treated with 80 watts of argon plasma for 5, 60, and 150 seconds, respectively, nanoparticles could be synthesized with efficiency rates of upwards of 98%. The size of nanoparticles synthesized in this work was studied using Scanning Electron Microscopy, and the scattering properties of the nanoparticles was studied using UV/Vis spectroscopy. Transmission Electron Microscopy with corresponding elemental analysis was also very useful in confirming the identity of the synthesized nanoparticles. The results from this study reveal that we have synthesized metal nanoparticles with distinct chemical and physical properties. Scanning Electron Microscopy depicts AgNPs with a round-shape and diameters from 40–80 nm, while AuNPs were hexagonal, with sizes from 40–80 nm, and CuNPs were rod-shaped, with dimensions 40 by 160 nm. Our findings demonstrate that the argon plasma approach used in this study is a rapid, green, and versatile reduction method for the synthesis of both noble and non-noble metal nanoparticles. [ABSTRACT FROM AUTHOR]

The synthesis of valuable organic compounds is a novel possibility for the application of physical plasma. As model reactants 2,5-dihydroxybenzoic acid derivatives were used and the resulting reactions investigated in detail. The formation of methoxylated and hydroxylated products as well as dimers (biaryls) was mediated by physical plasma in aqueous solution at atmospheric pressure and room temperature. Additionally, nitrated or nitrosated products were assumed. The direct (reactant is part of the liquid which is plasma-treated) and indirect (liquid is treated by plasma and afterwards reactant is added) plasma treatment resulted in a partly different product pattern, but both reaction concepts are suitable for the synthesis of organic compounds. The influence of operating parameters such as duration of plasma treatment, volume of the liquid, or concentration of reactants was varied to study the reaction course in order to increase product yields. Nitrite, nitrate, hydrogen peroxide, a decreased pH-value and an increased temperature was determined for the plasma-treated liquid. Consequently, the reactions with the 2,5-dihydroxybenzoic acid derivatives were pursued in the presence of these compounds at acidic pH-value and 50 °C. As result, nitrite, a low pH-value (pH = 2.2) and an elevated temperature were at least in part responsible for the formation of the products. The advantages of plasma-mediated synthesis are discussed in detail. The environmentally friendly reaction conditions without the need for catalysts or buffer components recommend physical plasma as novel mean in green chemistry. [ABSTRACT FROM AUTHOR]

The effects of Al microparticles on plasma chemistry and structural dynamics of laser-ablated pure and aluminized 5-methyl-1H-tetrazole (C2H4N4) are investigated with nanosecond laser induced breakdown spectroscopy (LIBS). Time-resolved and time-integrated emission spectra of the CN violet system (B2Σ+ − X2Σ+, Δν = 0 sequence) and C2 swan system (d3Πg − a3Πu, Δν = 0 sequence) are obtained and analyzed. The intensities of the CN and C2 emissions are increased by the Al microparticles, and their lifetimes in the laser-induced plasma are also altered. Furthermore, spatially and temporally resolved imaging measurements of the CN and C2 emissions are also conducted. The addition of Al microparticles leads to facilitated expansion and splitting of the laser-induced plasma. [ABSTRACT FROM AUTHOR]

The results of plasma-chemical synthesis of nanodiamonds from carbon nanostructures in a microarc discharge are presented. The electrodes used in the experiments were a molybdenum cathode and a copper anode coated with carbon nanostructures, such as carbon nanotubes, fullerene soot, and graphene. The formation of carbon nanostructures on the surface of the copper electrode was carried out in an electric arc embedded in a liquid hydrocarbon. At the next stage, these carbon nanostructures served as a source of atomic carbon from the surface of the anode of the microarc discharge. It was found that carbon nanotubes, graphene, and nanodiamonds are synthesized on the cathode surface. A significant influence on their formation is exerted by both the surrounding gaseous medium, and the electrophysical parameters of the arc discharge (current and electric field intensity distribution). Two types of nanodiamonds of size 50–100 nm and 5–10 nm have been synthesized, with large nanodiamonds being located separately and small ones as a necklace. The time of formation of microdiamonds is several tens of seconds, which differs by orders of magnitude from those obtained by traditional methods of their production. [ABSTRACT FROM AUTHOR]

As the analysis of complicated reaction chemistry in bulk plasma has become more important, especially in plasma processing, quantifying radical density is now in focus. For this work, appearance potential mass spectrometry (APMS) is widely used; however, the original APMS can produce large errors depending on the fitting process, as the fitting range is not exactly defined. In this research, to reduce errors resulting from the fitting process of the original method, a new APMS approach that eliminates the fitting process is suggested. Comparing the neutral densities in He plasma between the conventional method and the new method, along with the real neutral density obtained using the ideal gas equation, confirmed that the proposed quantification approach can provide more accurate results. This research will contribute to improving the precision of plasma diagnosis and help elucidate the plasma etching process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Selective removal of SiN, SiO 2 , and poly-Si films in hydrofluorocarbon chemistry (CHF 2 CF 3 , CF 3 CH 3 , and CHF 2 CH 3). • CHF 2 CF 3 dissociates into CHF 2 + and C 2 HF 4 + ions and secondary CF 3 + and CF 2 + ions are formed. • CF 3 CH 3 dissociates into C 2 H 2 F+ and C 2 H 2 F 2 + ions and dominant CF 3 + ions remains. • CHF 2 CH 3 yields CHF 2 + and CF 2 CH 3 + ions, promoting polymer film deposition. Plasmas containing hydrofluorocarbon gases (CHF 2 CF 3 , CF 3 CH 3 , and CHF 2 CH 3) are used for the selective removal of SiN, SiO 2 , and poly-Si films when manufacturing large-scale integrated circuits. Understanding the plasma chemistry of hydrofluorocarbons is important for gaining insight into the mechanisms of these selective-etching processes. The fragmental reactants produced by the reactive plasma are essential for evaluating and controlling highly accurate selective etching. This study examined such fragments using a primary dissociation ionization threshold quadrupole mass spectrometer at an electron energy of 20 eV. Their primary dissociative ionization thresholds were identified using photoelectron-photoion coincidence spectroscopy, with photon energies ranging from 10 to 28 eV. The results showed the following: (i) the CHF 2 CF 3 molecule dissociated into ions such as CHF 2 + and C 2 HF 4 +, which formed secondary ions, such as CF 3 + and CF 2 +. The F-rich reactants effectively enhanced the etching of both SiO 2 and SiN; (ii) the CF 3 CH 3 molecule dissociated into ions such as C 2 H 2 F+ and C 2 H 2 F 2 +, while the dominant CF 3 + remained as a crucial fragment for the primary etching of SiO 2 ; (iii) the CHF 2 CH 3 molecule predominantly yielded ions such as CHF 2 +, CF 2 CH 3 + and C x H y +, promoting polymer film deposition on the surfaces of SiO 2 and poly-Si. [ABSTRACT FROM AUTHOR]

The oxygen dynamics in a reactive Ar/O2 high power impulse magnetron sputtering discharge has been studied using a new reactive ionization region model. The aim has been to identify the dominating physical and chemical reactions in the plasma and on the surfaces of the reactor affecting the oxygen plasma chemistry. We explore the temporal evolution of the density of the ground state oxygen molecule O2(Xµ ∑-g, the singlet metastable oxygen molecules O2 (aµΔg) and O2(bµ ∑-g, the oxygen atom in the ground state O(³P), the metastable oxygen atom O(¹D), the positive ions O+2 and O+, and the negative ion O-. We furthermore investigate the reaction rates for the gain and loss of these species. The density of atomic oxygen increases significantly as we move from the metal mode to the transition mode, and finally into the compound (poisoned) mode. The main gain rate responsible for the increase is sputtering of atomic oxygen from the oxidized target. Both in the poisoned mode and in the transition mode, sputtering makes up more than 80% of the total gain rate for atomic oxygen. We also investigate the possibility of depositing stoichiometric TiO2 in the transition mode. [ABSTRACT FROM AUTHOR]

[Display omitted] • CO 2 decomposed with olefin epoxidation in plasma millifluidic reactor. • Epoxide yields optimized to around 90%. • O atoms from CO 2 decomposition propagated up to 30 mm. • Inverse CO 2 decomposition suppressed by sequestering O atoms with olefin. The integration of nonthermal CO 2 plasma for olefin epoxidation within a biphasic gas–liquid millifluidic system is presented. In this innovative approach, CO 2 is efficiently reduced to CO and O atoms, facilitating the epoxidation of olefins. Analysis of the system's effluent shows that epoxide production efficiency and yields, optimized to 90 %, significantly surpass those of traditional plasma methods, attributed to the enhanced gas–liquid mass transfer within the millifluidic environment. Moreover, O atoms generated from CO 2 decomposition was observed to travel up to 30 mm in the post-plasma discharge area, enhancing the gas–liquid flow system's efficiency. By capturing O atoms in the epoxidation reaction with olefins, the reverse reaction with CO is minimized, which in turn, markedly increases CO yield under the same conditions without olefins. These findings demonstrate that olefin epoxidation can be activated through CO 2 plasma discharge in a controlled, selective, and catalyst-free manner under gentle conditions. This synergy between nonthermal plasma and millifluidic technologies paves the way for overcoming current limitations in plasma chemistry with industrial relevance. [ABSTRACT FROM AUTHOR]

The n-type Mg 3.2 Sb 1.5 Bi 0.5 has emerged as a promising candidate for thermoelectric materials and has attracted significant research interest. However, effective n-type dopants have been predominantly limited to chalcogens. In our work, we found that rare-earth elements (Er, Tb, Tm) are highly effective dopants for n-type Mg 3.2 Sb 1.5 Bi 0.5. Through a combination of theoretical predictions and experimental validations, we demonstrate that these dopants significantly enhance the carrier concentration, leading to improved thermoelectric performance. Specifically, we employed direct ball milling and spark plasma sintering to introduce rare-earth elements at the Mg sites. Experimental results show that doping rare-earth elements in n-type Mg 3.2 Sb 1.5 Bi 0.5 has a higher carrier concentration (≈ 8.4 × 1019 cm−3), which is higher than that of chalcogen-doped samples (≈ 2 × 1019 cm−3). High power factor (S 2 σ) ≈ 16 μ W cm−1K−2 was obtained in rare-earth elements (Er, Tb, Tm) doped samples. Combined with the lowered lattice thermal conductivity due to the introduction of effective phonon scattering centers in Mg 3.2− x A x Sb 1.5 Bi 0.5 (A= Er, Tb, Tm) sample. Finally, the ZT values of all doped samples reached ≈ 1.44 at 750 K. The highest peak ZT is ≈ 1.65 at 750 K for Mg 3.195 Er 0.005 Sb 1.5 Bi 0.5. The rare-earth elements (Er, Tb, Tm) doped n-type Mg 3 Sb 1.5 Bi 0.5 has comparable thermoelectric performance with the chalcogen-doped n-type Mg 3 Sb 1.5 Bi 0.5 , exhibiting promising potential for practical applications. This present work offers a comprehensive understanding of the effect of cation site doping improves the thermoelectric properties of n-type Mg 3 Sb 2. [Display omitted] • Introducing Er, Tb, and Tm into Mg 3.2 Sb 1.5 Bi 0.5 shifts the Fermi level, enhancing electron provision. • Lanthanide doping at Mg sites is more effective than chalcogens at Sb sites for n-type doping. • Er doping creates point defects, scattering high-frequency phonons and reducing lattice conductivity. • The highest peak ZT is approx 1.65 at 750 K for Mg 3.195 Er 0.005 Sb 1.5 Bi 0.5. [ABSTRACT FROM AUTHOR]

Cu 2 Se as a thermoelectric material has gained popularity in recent years because of the excellent properties resulting from its superionicity. In this study, Cu 2-x Ag x Se (x = 0, 0.05, 0.15, 0.25) samples were fabricated through the spark plasma sintering method, followed by a comprehensive microstructure and thermoelectric properties analysis. The results indicated that, when the doping amount of Ag is x ≥ 0.05, the CuAgSe phase is produced at room temperature, which introduces an energy filtering effect, resulting in an augmentation of the Seebeck coefficient and a reduction in the electrical conductivity. Ag doping leads to point defects, the disorder of cations, and the phase boundaries which increases phonon scattering, resulting in reduced thermal conductivity. At 773 K, the thermal conductivity decreases from 1.10 Wm−1K−1 for Cu 2 Se to 0.41 Wm−1K−1 for Cu 1.75 Ag 0.25 Se. Compared to ZT ∼ 0.8 for the intrinsic Cu 2 Se sample, the ZT of Cu 1.75 Ag 0.25 Se reaches 1.41 at 773 K, which is an increase of over 70 %. Cu 2-x Ag x Se thermoelectric materials were synthesized by vacuum melting followed by spark plasma sintering. The effects of Ag doping on the thermoelectric performance of Cu 2 Se were discussed.(a) The effect of Ag doping on the electron thermal conductivity (κ e) of Cu 2 Se. (b) The effect of Ag doping on the ZT average of Cu 2 Se. [Display omitted] • Ag doping leads to point defects, increasing phonon scattering. • Low energy carriers in the Cu 2 Se phase were scattered with Cu and Ag ions in the second phase. • Pore structure and lattice defects are beneficial for reducing thermal conductivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Methane pyrolysis using a gliding arc yields H 2 and valuable carbon materials. • A 0D chemical kinetics model was developed to elucidate the reaction mechanism. • The reaction pathways for carbon formation during this process were investigated. • The reaction between CH 4 and H significantly contributes to hydrogen production. • Electron-impact dissociation of C 2 H 2 greatly contributes to solid carbon formation. Nonthermal plasma-assisted methane pyrolysis has emerged as a promising approach for hydrogen production under mild conditions while simultaneously yielding valuable carbon materials. Herein, we develop a plasma chemical kinetic model to elucidate the underlying reaction mechanisms involved in methane pyrolysis to hydrogen and solid carbon within a gliding arc (GA) reactor. A zero-dimensional (0D) chemical kinetics model was developed to simulate the plasma chemistry during the GA-based methane pyrolysis process, incorporating reactions involving electrons, excited species, ions, and heavy species. The model accurately predicted methane conversion and product selectivity in agreement with the experimental data. A strong correlation between hydrogen production and methane conversion was observed, primarily driven by the reaction CH 4 + H → CH 3 + H 2, contributing 44.2% to hydrogen formation and 37.7% to methane depletion. Electron impact collisions with hydrocarbons play a secondary role, accounting for 31.1% of H 2 formation. This work provides a detailed investigation into the mechanism of solid carbon formation in GA-assisted methane pyrolysis. Most of the solid carbon originates from the electron impact dissociation of C 2 H 2 through reactions e + C 2 H 2 → e + C 2 + H 2 /2H and subsequent C 2 condensation. C 2 radicals are highlighted as the major contributors to solid carbon formation, accounting for 95.0% of the total carbon yield, which might be due to the relatively low C–H dissociation energy in C 2 H 2. This kinetic study offers a comprehensive understanding of the mechanisms behind H 2 and solid carbon formation during GA-assisted methane pyrolysis. [ABSTRACT FROM AUTHOR]

• Warm plasma systems are more efficient at NH 3 cracking than cold plasma reactors. • NH 3 cracking in warm plasma reactors mainly occurs via thermal chemistry. • Heat integration is required to improve cracking efficiency and maintain reactor integrity. NH 3 is emerging as a carrier of green H 2 , but it requires a green and economical NH 3 cracking process based on renewable energy. Plasma technology is promising for this purpose, as it can crack NH 3 without the need for a catalyst and is highly compatible with renewable electricity, reducing the environmental footprint of the cracking process. This work investigates the NH 3 cracking performance of four different warm plasma reactors with different configurations and operating in a wide range of conditions. We show that the NH 3 conversion in warm plasma reactors is primarily determined by the specific energy input, with the main difference observed in the energy cost (EC) of cracking. The lowest EC obtained is 146 kJ/mol but at a conversion of only 8 %. A more reasonable conversion of around 50 % yields an EC of around 200 kJ/mol in two of the reactors investigated. Plasma reactors operating at higher feed flow rates are more efficient and yield a higher H 2 production rate. Our data indicate that NH 3 cracking in these warm plasma reactors occurs mainly via thermal chemistry, with non-thermal plasma chemistry playing a less prominent role. NH 3 decomposes not only inside the plasma core but also in a hot volume around it, which reduces the EC. Our study shows that warm plasmas are significantly more efficient for NH 3 cracking than cold plasmas, even when the latter are combined with catalysts. [ABSTRACT FROM AUTHOR]

We have developed Eu:BaFCl ceramics with translucency and investigated the optical and scintillation properties. The emission peaks appeared at around 365 and 390 nm in Eu:BaFCl translucent ceramics. Photoluminescence and scintillation decay time constants were approximately 0.5 and 6 μs, which was typical value s of Eu:BaFCl. The afterglow levels were 50–80 ppm, which was superior to commercial Tl:CsI assessed in the same setup. Under 137Cs γ-ray irradiation, the scintillation light yield of the 0.1, 0.5, and 1.0 % Eu:BaFCl were calculated to be 9,000, 16,000, and 13,000 ph/MeV, respectively. The light yield of our translucent ceramic samples was shown to be much higher than that of the Eu:BaFCl single crystal (883 ph/MeV). • Eu-doped (0.1, 0.5, and 1.0 %) BaFCl translucent ceramics were synthesized by the spark plasma sintering method. • Eu:BaFCl samples showed blue luminescence with the maximum peak at 390 nm in both the photoluminescence and X-ray-induced scintillation spectra. • The 0.5 % Eu:BaFCl sample showed the highest light yield (16,000 ph/MeV) under 137Cs γ-ray irradiation. [ABSTRACT FROM AUTHOR]

The Bi 2 Te 3 -based alloys with atomically layered structure are the best thermoelectric performance at the vicinity of room temperature. However, the inferior mechanical properties due to weak van der Waals interactions between layers are the obstacle to further promote the widespread commercialized application. Here, the grain refinement BiSbTe alloys prepared by ball milling and spark plasma sintering (grain boundary engineering) is reported. The microstructure characterization results indicate that ball milling can significantly reduce the grain size. The grain boundary engineering can significantly improve Seebeck coefficient about 23 %, maintain large hall mobility and reduce the carrier thermal conductivity about 48 %, and the lattice thermal conductivity is slightly decreased about 15 % by enhanced grain boundary phonon scattering. The highest average ZT reaches 1.2 in the range of 300–400 K for grain refinement sample, which is beneficial to improve the conversion efficiency of thermoelectric devices, and the Vickers hardness of the corresponding sample is increased by 58 %. The easy-to-operate strategy of grain refinement caused by ball milling provides a way to mass produce high performance and robust mechanical properties Bi 2 Te 3 -based thermoelectric devices. • The grain boundary engineering can significantly reduce thermal conductivity. • The coordinated regulation of electro-thermal-mechanical properties was achieved. • Our work provides a method to the large-scale production of Bi 2 Te 3 alloys. • The high Vickers hardness can promote the development of thermoelectric devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Investigation of the mechanical properties of Y 2 O 3 ceramics after different plasma exposure times. • Change of Y 2 O 3 surface topography and surface chemistry depending on the plasma exposure time was observed. • The initial decrease in mechanical properties is attributed to nanoscale pits created by ion sputtering. • Improvement in mechanical properties is linked to the formation of a passivation layer of YO x F y. • Insights were provided into the erosion resistance of Y 2 O 3 ceramics in CF 4 etching plasma. Although advanced ceramics such as Y 2 O 3 ceramics are used in semiconductor etching equipment for their excellent erosion resistance, the influence of plasma exposure on the mechanical properties of Y 2 O 3 ceramics is not fully understood. In this study, the Y 2 O 3 ceramics were prepared by vacuum sintering and the mechanical properties, microstructure, and surface composition of the Y 2 O 3 ceramics were investigated after different times of plasma exposure. Scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy were used to study the surface morphology and the corresponding reaction layer. The microstructural evolution of Y 2 O 3 ceramics in plasma reveals the initial decrease in mechanical properties corresponding to the creation of nanoscale pits on the surface by ion sputtering. The subsequent apparent improvement in the mechanical properties of Y 2 O 3 ceramics can be attributed to the formation of a passivation layer of YO x F y by reactive-ion etching. This finding provides a valuable insight into the erosion resistance of Y 2 O 3 ceramics in CF 4 etching plasma. [ABSTRACT FROM AUTHOR]

This work analyzes the interaction between non-equilibrium plasma and detonation. The aim is to enhance the detonability of gaseous mixtures by reducing the detonation cell width through dissociation of a fresh gas mixture by plasma action. The experiments were performed in a square-section detonation tube, and the diagnostic tools used were ICCD chemiluminescence imaging, soot-plate recording, dynamic pressure sensors, and back current shunt technique. The results show that the application of a nanosecond plasma ahead of a self-sustained detonation reduces the cell width by a factor of about 2 in H 2 :O 2 :Ar, H 2 :O 2 , CH 4 :H 2 :O 2 :Ar and CH 4 :O 2 :Ar mixtures for initial pressures between 100 and 200 mbar. A parametric study of plasma properties focused on the effect of the initial pressure on the deposited energy and homogeneity. A kinetic mechanism was proposed to estimate the dissociation effect of plasma chemistry on the fresh combustible mixture. The obtained densities of atoms produced in the plasma were used as input parameters to calculate the thermicity and temperature profiles of the detonation reaction zone according to the Zel'dovich–von Neumann–Döring model. The reduction factor of the ZND characteristic chemical length is about the same as the experimental cell widths, i.e. 2. This combination of experiments and calculations substantiates the relationship between plasma parameters, ZND chemical lengths, and detonation cell widths and, thus, demonstrates the possibility of controlling detonability using a nanosecond discharge. Novelty and significance The novelty is the first experimental demonstration that the action of a non-equilibrium plasma on a fresh combustible mixture can instantaneously produce enough atomic species ahead of a self-sustained detonation front to reduce by about half the mean width of the cells that structure the detonation reaction zone in gases. The significance is that a nanosecond discharge is now proven to be a means of controlling detonability, here considered as the ability of a detonation to propagate in a device of given transverse dimensions, since the smaller the cells, the higher the detonability. [ABSTRACT FROM AUTHOR]

• Epoxy resin-based composite insulator degrades when exposed to partial discharges (PDs); • PDs activity led to partial or total erosion of epoxy resin; • air-plasma action can trigger chemical reactions on the surface of epoxy resin; • CO 2 -plasma causes only erosion effects. Failures due to the degradation of polymeric insulation in components of electrical power systems are difficult to predict. Partial discharges (PDs) are one of the main phenomena that contribute to polymeric insulators' aging. Therefore, a better understanding of the aging process due to PDs is crucial to develop effective models that predict degradation, optimize materials and propose diagnostic indicators. Here we present an experimental characterization, via Fourier-transform Infrared spectroscopy (FTIR), of a composite material exposed to PDs. The material consisted of cured epoxy resin mixed with silica (quartz). Aging tests with surface discharges, using a needle-plate configuration, were conducted considering two atmospheres (air and CO 2) and four exposition times (6, 24, 72 and 120 hours). To aid the interpretation of spectroscopic data, we included a series of simulation results. The main effect observed was the erosion and removal of epoxy resin from the surface of the samples, proportionally to treatment time and distance from the needle. Along with erosion, new chemical species (possibly oxalate salts) were detected on the surface exposed to air-plasma. These species were likely formed and then removed due to plasma activity over time. On the other hand, samples aged in CO 2 atmosphere underwent only epoxy resin erosion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Increasing hydrogen production by supplying ammonia from downstream of microwave plasma jet. • Controlling plasma temperature by adding nitrogen or ammonia into argon to further enhance ammonia conversion. • Increasing the side branches of ammonia supply downstream to optimize ammonia conversion and hydrogen production. Hydrogen has been conceived as an alternative to hydrocarbons to achieve a carbon–neutral society, with ammonia emerging as the most practical hydrogen carrier for long-distance transportation. Conventional thermo-catalytic cracking of ammonia is an energy-intensive process, leading to the consideration of low-temperature plasmas as potential alternatives. Recently, a surfatron-based Microwave Plasma Jet (MWPJ) was investigated, demonstrating the fundamental physical and chemical mechanisms of NH 3 cracking. In this study, we present an optimization scheme for NH 3 cracking using a surfatron-based argon MWPJ to improve H 2 production rate and efficiency. Our approach included: (i) introducing downstream inlets of NH 3 to decouple NH 3 from plasma generation and (ii) adding additive (N 2 or NH 3) to the main Ar flow to elevate the gas temperature of the MWPJ. We found that both additives to the Ar flow raised the gas temperature from 2700 K up to 4200 K (N 2) or 5400 K (NH 3), showing a trade-off between gas temperature and the height of the MWPJ. The case with NH 3 added to the main Ar flow showed better performance than the case with N 2 due to the higher gas temperature and additional H 2 production from the additive NH 3. The main NH 3 supply in the downstream showed no negative effect on the plasma generation and significantly increased the H 2 production rate and efficiency, primarily due to the sufficient NH 3 supply rate. Increased number of NH 3 inlets also facilitated NH 3 cracking, illustrating saturated performance with four inlets. To scale up this process, the obtained optimal geometry and operating conditions will be further explored using a high-power microwave system. [ABSTRACT FROM AUTHOR]

This study investigates the intricate mechanisms that govern irradiation damage in high-entropy ceramic materials. Specifically, we synthesized (Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2)C high-entropy carbide ceramics (HECC) with a single-phase rock-salt structure using spark plasma sintering. These ceramics were then subjected to irradiation with 1.08 MeV C ions, resulting in a dose of 7.2 dpa (dpa: displacements per atom) at both room temperature (RT) and 500 °C. To understand the resulting damage structure, we analyzed bulk irradiated HECC samples using Grazing Incidence X-ray Diffraction (GIXRD) and Transmission Electron Microscope (TEM) at both irradiation temperatures. GIXRD analysis revealed an average tensile strain out-of-plane of 0.16% for RT irradiation and 0.14% for irradiation at 500 °C. In addition, TEM analysis identified a buried damaged band, approximately 970 nm thick, under both irradiation temperatures. By employing the bright field TEM imaging technique under kinematic two-beam conditions, dislocation loops of both a/3 〈111〉{111} and a/2 〈110〉{110} types within the damaged band were observed. Furthermore, our analysis indicated an increase in the average size of the total dislocation loops within the band from 1.2 nm to 1.4 nm as the density decreased. Importantly, no amorphization, precipitates, or voids were detected in the damaged band under both irradiation temperatures. Density functional theory (DFT) simulations indicated that carbon predominantly resides in 〈110〉 split interstitial sites causing lattice expansion, while vacancies, particularly Nb, induced compression along the c-axis. Carbon atoms tend to bond when collectively present in the <110> split interstitial sites, contributing to the formation of interstitial loops. • (Hf 0.2 Zr 0.2 Ta 0.2 Nb 0.2 Ti 0.2)C were studied by 1080 keV carbon ion irradiation at RT and 500 °C. • Post-irradiation, the average tensile strain out-of-plane measured 0.16% at RT and 0.14% at 500 °C. • The average size of dislocation loops increased from ∼1.2 nm at RT to ∼1.4 nm at 500 °C. • No amorphization, precipitates or voids were detected within the damaged band under both irradiation conditions. • DFT simulations revealed that carbon predominantly occupies the <110> split interstitial site, resulting in the lattice expansion. [ABSTRACT FROM AUTHOR]

Plasma catalysis is an emerging process electrification technology for industry decarbonization. Plasma-catalytic dry reforming of methane relies on the mutual effects of the plasma and the catalyst leading to the higher chemical conversion efficiency. The effects of catalyst surfaces on the plasma are predicted to play a major role, yet they remain unexplored. Here, a 1D plasma fluid model combined with 0D surface kinetics is developed to reveal how the surface reactions on platinum (Pt) catalyst affect the redistribution of the gas-phase particles. Two contrasting models with and without the surface kinetics as well as the Spearman rank correlation coefficients are used to quantify the effect of the key species (H, CH, CH2) on the CO generation. Advancing the common knowledge that Pt catalyst can influence the plasma chemistry directly by changing the surface loss/production of particles, this study reveals that the catalyst can also affect the spatial distributions of active species, thereby influencing the plasma chemistry in an indirect way. This result goes beyond the existing state-of-the-art which commonly relies on over-simplified 0D models which cannot resolve the spatial distribution. Further analysis indicates that the species spatial redistribution is driven by the dynamic catalyst surface adsorption-desorption processes. This work enables the previously elusive account of active species redistribution and may open new opportunities for plasma-catalytic sustainable chemical processes. [ABSTRACT FROM AUTHOR]

As low-temperature plasma plays an important role in semiconductor manufacturing, plasma diagnostics have been widely employed to understand changes in plasma according to external control parameters, which has led to the achievement of appropriate plasma conditions normally termed the process window. During plasma etching, shifts in the plasma conditions both within and outside the process window can be observed; in this work, we utilized various plasma diagnostic tools to investigate the causes of these shifts. Cutoff and emissive probes were used to measure the electron density and plasma potential as indicators of the ion density and energy, respectively, that represent the ion energy flux. Quadrupole mass spectrometry was also used to show real-time changes in plasma chemistry during the etching process, which were in good agreement with the etching trend monitored via in situ ellipsometry. The results show that an increase in the ion energy flux and a decrease in the fluorocarbon radical flux alongside an increase in the input power result in the breaking of the process window, findings that are supported by the reported SiO2 etch model. By extending the SiO2 etch model with rigorous diagnostic measurements (or numerous diagnostic methods), more intricate plasma processing conditions can be characterized, which will be beneficial in applications and industries where different input powers and gas flows can make notable differences to the results. [ABSTRACT FROM AUTHOR]

High coke-resistant Ca-promoted NiCo–NiAl 2 O 4 nanocatalysts with different calcium loading (0, 0.25, 0.5 and 1.5 wt%) were synthesized via hybrid sol-gel-plasma method. Synthesized samples were applied in the CH 4 /CO 2 /O 2 reforming to H 2 reactions. Analyses revealed that the calcium addition caused the lower surface area, non-uniform distribution and larger particle size. Therefore, higher activity and yield were found for the nanocatalyst without calcium while catalytic activity and yield were descended for the other ones. This trend was according to the covering effect of calcium and undesirable effect of calcium over the surface area and particle size distribution. But owing to the enhanced coke gasification rate of Ca-rich samples, by increasing of Ca amount, coke deposition was descended and stable performance was promoted. Due to the time on stream performance (TOS) during the 48 h and at 750 °C, 1.5 wt% Ca-promoted NiCo–NiAl 2 O 4 (NCCa1.5A (SGP)) was stable, but demonstrated the lower yield. Moreover, 0.25 wt% Ca-promoted NiCo–NiAl 2 O 4 nanocatalyst (NCCa0.25A (SGP)) was illustrated the higher yield in comparison with NCCa1.5A (SGP). It must be noted that just 2.7% deactivation for H 2 yield was detected for NCCa0.25A (SGP) during the 48 h TOS performance. H 2 yield of the NCCa0.25A (SGP) at 850 °C was 84%. Based on the reverse trends of the yield and TOS performance, NCCa0.25A (SGP) was able to present as a promising nanocatalyst for CH 4 /CO 2 /O 2 reforming to H 2. Moreover, this offer was ascribed to the excellent coke resistance and superior catalytic performance of NCCa0.25A (SGP). • Synthesis of Ca-promoted NiCo/NiAl 2 O 4 nanocatalysts via hybrid sol-gel plasma method. • Uniform morphology and homogeneous particles size distribution for 0.25 wt% Ca-promoted one. • Stable yield and H 2 /CO ≈ 1 for 0.25 wt% Ca-promoted catalyst during 48 h stability test at 750 °C. • Low amount of coke deposition for 0.25 wt% Ca-promoted nanocatalyst after 48 h TOS. • 0.25 wt% Ca-promoted nanocatalyst preserved it structure after 48 h TOS. [ABSTRACT FROM AUTHOR]

The present study describes a method for plasma‐assisted in situ chemical polymerization of polypyrrole on nylon‐66 fabric to improve adhesion and conductivity of the polypyrrole coating. Plasma generated from various gas mixtures in dielectric barrier discharge were used to modify the surface of nylon‐66 fabric and investigated the influence of plasma on surface chemistry and morphology of nylon‐66 fabric. Polypyrrole was then deposited over this plasma pretreated nylon fabric by using oxidative chemical polymerization to get electrically conducting nylon fabric. Surface physical and chemical changes of plasma treated nylon‐66 fabric were studied by scanning electron microscopy (SEM), wettability, attenuated total reflection‐Fourier transform infrared spectroscopy (ATR‐FTIR) and X‐ray photoelectron spectroscopy (XPS). Effect of the plasma treatment on binding strength was analyzed by studying abrasion resistance and surface resistivity. Results showed that the strongest interfacial bonding and high conductivity were achieved for He+O2 plasma pretreated PPy coated nylon‐66 fabric. Surface functional groups such as CO, COH, COOH, and CONH were detected on plasma treated nylon‐66 fabric by XPS. These surface functional groups are responsible for the improved adhesion and conductivity of PPY coating on nylon fabric by 35% (up to 2500 abrasion cycles) and 50%, respectively. [ABSTRACT FROM AUTHOR]

This work reports the operation of rotating gliding arc (RGA) reactor at a high flow rate and the effect of flow regimes on its chemical performance, which is not explored much. When the flow regime was changed from transitional to turbulent flow ( 5 → 50 SLPM ), operation mode transitioned from glow to spark type; the average electric field, gas temperature, and electron temperature raised ( 106 → 156 V · mm - 1 , 3681 → 3911 K , and 1.62 → 2.12 eV ). The decomposition's energy efficiency ( η E ) increased by a factor of 3.9 ( 16.1 → 61.9 g CH 4 · kWh - 1 ). The first three dominant methane consumption reactions (MCR) for both the flow regimes were induced by H , CH, and CH 3 (key-species), yet differed by their contribution values. The MCR rate increased by 80–148% [induced by e and singlet— N 2 ], and decreased by 34–93% [CH, CH 3 , triplet— N 2 ], due to turbulence. The electron-impact processes generated atleast 50% more of key-species and metastables for every 100 eV of input energy, explaining the increased η E at turbulent flow. So, flow regime influences the plasma chemistry and characteristics through flow rate. The reported RGA reactor is promising to mitigate the fugitive hydrocarbon emissions energy efficiently at a large scale, requiring some optimization to improve conversion. [ABSTRACT FROM AUTHOR]

The direct N-acylation of amines by esters in a microreactor is described using argon plasma, thereby producing amides in good to excellent yields. [ABSTRACT FROM AUTHOR]