Search

In this study, we investigated the creation of mono crystalline diamond membranes for use in two-dimensional optical cavities. The creation method involves ion irradiation to create a buried layer of damaged material that is removed to leave a free-standing mono crystalline top layer. Simulations were used to determine the optimal parameters for irradiation, which were tested in experiments. Hydrogen ions were found to be the optimal ion species for irradiation, and long-term high-temperature annealing was beneficial in reducing ion-induced damage in the membrane. The resulting membranes, which were 300 nm thick, contained a high density of negatively charged nitrogen-vacancy centers. Their optical and spin properties were analyzed. The findings of this study can be applied to the creation of diamond membranes hosting other color centers, with thicknesses matched to their respective fluorescence. [ABSTRACT FROM AUTHOR]

To efficiently generate H − ions from positive atomic or molecular hydrogen beams injected onto a solid surface, it has been suggested to use a material with a low-work function as the target material. However, it is not clear under what conditions the most efficient H − production is realized for incident beam parameters or reflection angles. Therefore, we studied the interaction between low-energy atomic and molecular hydrogen beams (less than 1 keV/nucleon) with a low-work function electride 12CaO ⋅ 7 A l 2 O 3 (C12A7). The production ratio of H − to H + ions from the C12A7 electride was much higher than Mo targets with higher work functions, especially at smaller incident and smaller reflection angles. The H − to H + production ratio slightly increased as the incident energies were decreased, but there was no significant difference between the electride and Mo targets. These results indicate that smaller incident angles and lower beam energies of the incident hydrogen beam are favorable for the enhancement of the production ratio of H − to H + ions in C12A7. The higher production ratio appeared at the vertical beam energies less than on the order of 100 eV, where quantum mechanical processes may become important. [ABSTRACT FROM AUTHOR]

A recently initiated variant of density functional theory utilizes a set of spherically symmetric densities instead of the density. The exact functionals are unknown in the new theory akin to the standard density functional theory. In order to test approximate functionals exactly solvable models are introduced. A harmonic molecular ion, the analogue to the hydrogen molecule ion and a harmonic two-electron molecule showing analogy to the hydrogen molecule are proposed. It has been found that the wave function and the density can be given analytically. The exact spherical densities and the effective potentials of the Euler equations also have analytical form. It has been shown that the models can be easily extended to several "nuclei." [ABSTRACT FROM AUTHOR]

ITER is of key importance in the European fusion roadmap as it aims to prove the scientific and technological feasibility of fusion as a future energy source. The EUROfusion consortium of labs within Europe is contributing to the preparation of ITER scientific exploitation and operation and aspires to exploit ITER outcomes in view of DEMO. The paper provides an overview of the major progress obtained recently, carried out in the frame of the new (initiated in 2021) EUROfusion work-package called ' Pr eparation of I TER O peration' (PrIO). The overview paper is directly supported by the eleven EUROfusion PrIO contributions given at the 29th Fusion Energy Conference (16–21 October 2023) London, UK [www.iaea.org/events/fec2023]. The paper covers the following topics: (i) development and validation of tools in support to ITER operation (plasma breakdown/burn-through with evolving plasma volume, new infra-red synthetic diagnostic for off-line analysis and wall monitoring using Artificial Intelligence techniques, synthetic diagnostics development, development and exploitation of multi-machine databases); (ii) R&D for the radio-frequency ITER neutral beam sources leading to long duration of negative deuterium/hydrogen ions current extraction at ELISE and participation in the neutral beam test facility with progress on the ITER source SPIDER, and, the commissioning of the 1 MV high voltage accelerator (MITICA) with lessons learned for ITER; (iii) validation of neutronic tools for ITER nuclear operation following the second JET deuterium–tritium experimental campaigns carried out in 2021 and in 2023 (neutron streaming and shutdown dose rate calculation, water activation and activated corrosion products with advanced fluid dynamic simulation; irradiation of several materials under 14.1 MeV neutron flux etc). [ABSTRACT FROM AUTHOR]

Pulse plasma ion sources have been shown to be capable of achieving high negative hydrogen ion densities ( n H − ) or currents. The fast cooling of the electrons and reduction in the electron density (n e) provide favorable plasma conditions to improve the H− production, with a high density ratio of negative hydrogen ions to electrons during the pulse-off period. The purpose of this research is to further improve the performance of volume-produced H− ion sources based on the pulse power modulation. In this study, a time-modulated negative hydrogen plasma sustained by 10 kHz pulse power at the typical gas pressure of 0.3 Pa was numerically investigated using a global model. The model is compared with measurements obtained in a pulsed radio frequency ion source and shows a reasonable agreement. A steplike low-high power strategy in the active glow period and a short-pulse low power in part of the afterglow period are employed to mitigate overshoot of the electron temperature (T e) in the initial stage of the pulse period and to optimize H− production in the afterglow, respectively. The model predicts that a small-magnitude, short-duration low power operation in the afterglow increases n H − and decreases n e from the onset of the low power until the beginning of the next high power pulse, due to a modest temporary increase in the T e (less than 2 eV). It facilitates dissociative electron attachments and thus H− formation. The reduction in the n e indicates that positive ions lost to the walls cannot be compensated by weak ionization. H− production with a low number of co-extracted electrons can be optimized by adjusting the magnitude and duration of the low power in the afterglow. [ABSTRACT FROM AUTHOR]

Catalyst‐controlled diversity‐oriented synthesis (CatDOS) is an important research area for expanding molecular complexities and achieving high atomic economics. Many regiodivergent syntheses have been achieved through metal catalysis, covalent organocatalysis, and non‐covalent organocatalysis by controlling the molecular recognition function of the catalysts. However, the development of regiodivergent CatDOS through Brønsted base organocatalysis was relatively less developed than others so far. Numerous studies about Brønsted base organocatalysis have demonstrated the powerful molecular recognition abilities of their cationic conjugate acids mainly in controlling the stereoselectivity instead of the regioselectivity. This concept review aims to conceptualize a new perspective to consider the potential role of the cationic conjugate acid of Brønsted bases for regiodivergent CatDOS. Recent representative examples are selected to demonstrate the potential of cationic conjugate acids in site‐selectivity control in single bond and multiple bonds formation reactions. The summarized results show that even the conjugate acid of common tertiary amines, protic ammonium ions, could affect the regioselectivity in the early‐ or late‐stage step during multiple bonds formation after initial deprotonation. The results also suggested that the properties and ion‐pairing interactions of conjugate acid could be more important than the basicity of the base in controlling regioselectivity. Perspectives and hypotheses for explaining the mechanism of regioselectivity are also included in this review. [ABSTRACT FROM AUTHOR]

Recent advancements in omics and single-cell analysis highlight the necessity of numerical methods for managing the complexity of biological data. This paper introduces a simulation program for biochemical reaction systems based on the natural number simulation (NNS) method. This novel approach ensures the equitable treatment of all molecular entities, such as DNA, proteins, H2O, and hydrogen ions (H+), in biological systems. Central to NNS is its use of stoichiometric formulas, simplifying the modeling process and facilitating efficient and accurate simulations of diverse biochemical reactions. The advantage of this method is its ability to manage all molecules uniformly, ensuring a balanced representation in simulations. Detailed in Python, NNS is adept at simulating various reactions, ranging from water ionization to Michaelis-Menten kinetics and complex gene-based systems, making it an effective tool for scientific and engineering research. [ABSTRACT FROM AUTHOR]

The removal of Congo red (CR) and heavy metal ion nickel (Ni(II)) from wastewater is a critical concern for safeguarding the aquatic environment and promoting sustainable development. Herein, a novel citric acid steam-assisted decomposition method is applied to form meso-macroporous magnesium oxide (MgO) with rich oxygen defects. As the gelation process of xerogel precursor could be significantly promoted by the steam-assisted process with citric acid solution as steam source, the morphology structure of MgO changes into loose aggregates with sharp edges and is covered by a layer of MgO nanoparticles. The synthesized MgO, with a high surface area (103.60 m2 g−1), meso-macroporous structure and abundant oxygen defects, exhibits super adsorption capacities for CR (7109.85 mg g−1) and Ni(II) (1405.88 mg g−1). The MgO (0.4 g L−1) could completely remove CR (200 mg L−1) in 30 min, while 10 min for Ni(II) (200 mg L−1) adsorption. The adsorption mechanism of MgO for CR and Ni(II), including electrostatic interaction, oxygen vacancy capture, hydrogen bonding and ion exchange, is effectively enhanced due to the appearance of meso-macroporous structure and oxide defects, such as 5-coordinated oxygen anion (O 5C 2−) for terrace, 4-coordinated oxygen anion (O 4C 2−) for edge and 3-coordinated oxygen anion (O 3C 2−) for corner. The easy calcination is applied to recycle MgO after CR adsorption and the CR removal efficiencies are above 98 % after five cycles. Meanwhile, a nickel chelator (Na 2 EDTA) and calcination are used to regenerate the MgO after Ni(II) adsorption and the adsorbent shows an insignificant removal efficiency loss after three cycles. The meso-macroporous MgO with rich oxygen defects has the characteristics of high adsorption speed, high adsorption capacity and convenient recovery property, and is expected to become an ideal material for the rapid treatment of high concentration wastewater. [ABSTRACT FROM AUTHOR]

Different donor‐like defects at a depth of several microns below the surface in n‐type Si samples are observed after subjecting them to DC hydrogen plasma treatment, conducted with and without broadband illumination. These defects cannot be correlated with vacancies or interstitials, likely due to the low energy of H ions or hydrogen platelets typically reported after RF H plasma treatment in various studies. It is found that the concentration of these donor‐like defects is highest near the surface and is significantly influenced by the oxygen or oxygen and carbon concentration in the Si samples. Several of these defects can be attributed to shallow donors, whereas other are likely to be correlated with deep‐level defects. The origin of these defects will be discussed. [ABSTRACT FROM AUTHOR]

This study extensively investigates the modelling of the bipolar plates, flow field plates and fuel cell stacks of a Direct Alcohol Fuel cell. The crucial component of a fuel cell is the bipolar plates which supply fuel to anode and oxidant to cathode and also maintains electrical conduction between cells. Given that flow field plates plays an important role in distributing reactant gases to the reaction sites, modelling of flow field plates has thus proved to be quite challenging owing to the fact that the flow field plates has to be durable and conductive both thermally and electrically. Electrochemical losses are also observed in cases which occurs due to the diffusion of hydrogen ions and electrons and also sometimes due to the material’s natural resistance. These loses can only be minimised using thinner electrolyte membrane and operating the fuel cell at low temperatures. This study therefore aims at the extensive examination of various parameters including electrochemical and thermal parameters by computational modelling using MATLAB and PYTHON which plays a pivotal role in influencing the flow of reactants and amount of current generated. [ABSTRACT FROM AUTHOR]

Currently reported adsorption (hydroxyl or amidoxime) groups must dissociate hydrogen ions to form ─O− units for the coordination with uranyl ions. However, this process suffers a high energy barrier for bond dissociation, leading to the sluggish uptake speed and low adsorption capacity for uranium extraction from natural seawater. Herein, this study proposes a strategy for electrochemical modulation of adsorption sites, which overcomes the chemical dissociation processes of hydrogen ions. Poly‐2,5‐dihydroxy‐1,4‐benzoquinone containing redox carbonyl groups is intercalated into the channels of a covalent organic framework (COF) through in situ cross‐linking of 2,5‐dihydroxy‐1,4‐benzoquinone. Under electrochemical modulation, the C═O groups are transformed into adjacent phenol–oxygen anions to cooperate with the coordination atoms (O and N) on the COF channel for rapid binding of uranyl ions, which gave an absorption rate of 4.2 mg g−1 d−1 (≈3.3 ppb of uranium in natural seawater). Notably, the COF‐based electrodes delivered an average capacity of ≈20.8 mg‐U per g for uranyl ion adsorption during 5 days of extraction, ≈3000 times larger than that of classical tannin‐based adsorbents. The proposed method for preparing electrochemically modulated binding sites is expected to provide guidance for designing high‐efficiency adsorbents in the future. [ABSTRACT FROM AUTHOR]

Corrosion worldwide causes large losses of metal, which is why various ways are being sought to slow it down. The aim of this study was to investigate the inhibitory effect of fennel fruit essential oil (Foeniculum vulgare Mill.) and its main component anethole. The inhibitory effect of three different concentrations of the fennel essential oil and anethole (1.0 mL/L, 1.5 mL/L, and 2.5 mL/L) in a solution of 1 M HCl at 298 K for 6 h on a sheet of low-carbon steel was investigated. The inhibitory effect was established using gravimetric methods evaluating weight loss, corrosion rate, and inhibition efficiency, as well as electrochemical methods. In gravimetric studies, the inhibition effect of the inhibitors fennel essential oil and isolate anethole at a concentration of 2.0 mL/L was 70.85% and 45.86%, respectively. The anodic polarization curve data at 298 K demonstrate that the anethole and fennel essential oil adsorption on the metal surface creates a barrier that hinders hydrogen ions' access and prevents them from being reduced on the steel surface's cathode sites. Fennel essential oil acting as a mixed type-inhibitor can replace synthetic organic substances and could become an alternative to be used as environmental corrosion inhibitors. [ABSTRACT FROM AUTHOR]

Radiobiological studies focused mainly on tracking the effects of photons (X and gamma rays) and high-energy charged particles over low energy ions, which raises interest in studying their biological effects. Therefore, the aim of this study is to investigate the interaction of low-energy hydrogen ions beam with xcortical bovine bone as a biological model. A hydrogen ions beam was used to bombard cortical bone with different fluences; 45, 70 and 90×1017ions/cm2 at low energy of 5keV. The interaction of hydrogen ions with cortical bone was estimated theoretically by the SRIM/TRIM code. The obtained results showed that the average distribution range and the maximum depth for 5keV hydrogen ions are 91 and 150nm respectively. The energy losses from incident ions are 4.45keV for ionization, 170eV for phonons and 18eV for vacancies. Also, the energy losses from the recoil atoms are 119eV for ionization, 234eV for phonons and 8eV for vacancies. At the same time, the effect of low-energy hydrogen ions bombardment on the structure of bone was studied by X-ray diffraction (XRD) and FTIR. [ABSTRACT FROM AUTHOR]

The activation of poorly reactive substrates via strong chiral acids is a central topic in asymmetric ion pair catalysis these days. Despite highly successful scaffolds such as N‐triflylphosphoramides, these catalysts either lack C2‐symmetry or provide multiple H‐bond acceptor sites, leading to lower ee values for certain reactions. We present BINOL‐based diselenophosphoric acids (DSA) as an extremely promising alternative. Using an intertwined approach of synthesis and NMR studies, we developed a synthetic approach to DSA with up to 98 % NMR yield. The obtained acids provide both very high proton donor and proton acceptor properties, a bifunctionality, which is key to catalytic applications. Indeed, first reactivity test proved the much higher acidity of DSA and its ability to initiate Mukaiyama–Mannich reaction and protodesilylation of silyl ethers. Together with their C2‐symmetry, the single donor and single acceptor situation, the decreased tendency of self‐association, and the straightforward synthesis with potential 3,3'‐substitution, the DSA provide all features ideal for the further development of ion pair catalysis. [ABSTRACT FROM AUTHOR]

To harness the full potential of electrochemical water splitting for hydrogen and oxygen production, recent efforts have focused on the development of single atom catalysts (SACs) to enhance electrocatalytic performance while maximizing metal atom utilization. In this context, we have designed and assessed the feasibility of late first-row transition metal (TM) linked 1-Azahomocubane dimer as SACs for facilitating the water splitting reaction. The effectiveness of these designed electrocatalysts has been thoroughly evaluated through density functional theory (DFT) calculations. Remarkably, the Fe containing SAC demonstrated exceptional activity towards the hydrogen evolution reaction (HER) (ΔG H = −0.06), indicating the ability of Fe metal to facilitate the adsorption of hydrogen ions and their release as hydrogen gas. Furthermore, the Fe containing SAC revealed high stability and sufficient conductivity. This investigation underscores the potential utility of the Fe containing SAC as effective precious-metal free electrocatalysts for the HER. [Display omitted] • TM linked 1-Azahomocubane dimer SAC for water the splitting reactions. • Fe@2Cubane revealed ultra-high catalytic activity toward the HER. • The Fe based SACs serves as precious-metal free, chemically stable, and sufficiently conductive SACs. [ABSTRACT FROM AUTHOR]

In order to simulate hydrogen (H) plasma in the linear plasma device NAGDIS‐II, we have modified the fluid code LINDA‐NU to allow the simultaneous calculation of multiple ion species consisting of hydrogen atomic ions (H+$$ {\mathrm{H}}^{+} $$) and molecular ions (H2+,H3+$$ {\mathrm{H}}_2^{+},{\mathrm{H}}_3^{+} $$). In this simulation, H and H2$$ {\mathrm{H}}_2 $$ neutrals are assumed to be uniformly distributed in space in order to obtain initial qualitative results. The fraction of H3+$$ {\mathrm{H}}_3^{+} $$ ions increases as the H2$$ {\mathrm{H}}_2 $$ molecular density increases, and the recombination process between H3+$$ {\mathrm{H}}_3^{+} $$ and electrons is observed to reduce the particle flux to the target plate. With an increase in H density, the electron density increases due to the decrease in ion flow velocity due to the change exchange process, and the electron temperature decreases to less than 1 eV, leading to the detached plasma formation attributed to the electron‐ion recombination process. [ABSTRACT FROM AUTHOR]

Malachite green (MG) dye and cadmium metal ion are toxic pollutants that should be removed from aqueous environment. The recent study aimed to examine the adsorption behavior of MG dye and Cd (II) from wastewater onto low-cost adsorbent prepared by activating corn silk with nitric acid (ACS) and characterized by SEM, FTIR, XRD, BET and TGA. The optimum MG and Cd (II) adsorption was observed at pH 7 and pH 9 and maximum uptake of both pollutants was at 0.5 g dosage, 60 mins contact time and 20 mg/L initial concentration. The retention of dye and metal ion by the studied adsorbent was best fit to Langmuir isotherm and Pseudo-second order kinetics. The maximum monolayer coverage capacity of ACS for MG dye and Cd (II) ion was 18.38 mg/g and 25.53 mg/g, respectively. Thermodynamic studies predicted a spontaneous reaction with exothermic process for MG dye whereas an endothermic and spontaneous process was confirmed for Cd ion based on estimated parameters. The adsorption mechanism of MG dye and Cd (II) uptake was by combination of electrostatic interaction, pore diffusion, ion exchange, pie-pie attraction, hydrogen bonding, and complexation. The adsorbed pollutants were effectively desorbed with significant regeneration efficiency after successive five cycles that proved the potential of low-cost biosorbent for selective sequestration of cationic dye and divalent metal ion from effluents. The use of nitric acid-modified corn silk has been reported to enhance its adsorption performance over the unmodified cob for pollutants such as cadmium ions and malachite green. Although there may be no recorded data on the adsorption efficiency of acid-treated corn silk for selected pollutants, it can be considered as a prospective bio-sorbent owing to its chemical composition and functional groups for exchange of hydrogen ions for other cations. [ABSTRACT FROM AUTHOR]

Dipines are a type of important antihypertensive drug as L-calcium channel blockers, whose core skeleton is the 1,4-dihydropyridine structure. Since the dihydropyridine ring is a key structural factor for biological activity, the thermodynamics of the aromatization dihydropyridine ring is a significant feature parameter for understanding the mechanism and pathways of dipine metabolism in vivo. Herein, 4-substituted-phenyl-2,6-dimethyl-3,5-diethyl-formate-1,4-dihydropyridines are refined as the structurally closest dipine models to investigate the thermodynamic potential of dipine oxidative metabolism. In this work, the thermodynamic cards of dipine models' aromatization on 21 potential elementary steps in acetonitrile have been established. Based on the thermodynamic cards, the thermodynamic properties of dipine models and related intermediates acting as electrons, hydrides, hydrogen atoms, protons, and two hydrogen ions (atoms) donors are discussed. Moreover, the thermodynamic cards are applied to evaluate the redox properties, and judge or reveal the possible oxidative mechanism of dipine models. [ABSTRACT FROM AUTHOR]

The linear and nonlinear effects of hydrogen isotope species on ion temperature gradient (ITG) instability in the Large Helical Device (LHD) stellarator are studied using radially global gyrokinetic simulation. We found that the coupling range of linear toroidal harmonics depends on the ion mass of the hydrogen isotope. The growth rates of ITG mode are almost the same for H, D, and T plasmas, indicating a gyro-Bohm scaling of ion-mass dependence. The nonlinear electrostatic simulations show that the zonal flow breaks the radially elongated eigenmode structures and reduces the size of the turbulence eddies, which suppresses the turbulence and the ion heat transport in the LHD. The turbulence amplitude without the zonal flow is almost the same for H, D, and T plasmas, while it decreases with increasing ion mass of the hydrogen isotope when the zonal flow is present. The reduction of the turbulent transport with larger ion mass is mostly due to the enhancement of zonal flows by larger ion mass. The ion heat conductivity deviates from the gyro-Bohm scaling for both cases with and without the zonal flow. [ABSTRACT FROM AUTHOR]

Investigation of surface blistering and exfoliation in silicon carbide (SiC) by H+ ion irradiation can be utilized for the smart cut or ion cut process, which will overcome the major challenges impeding the technological development of SiC. Blister formation and exfoliation in cubic 3CSiC were studied by carrying out 50 keV H+ ion irradiations. Both formation and exfoliation of blisters were observed in post-annealed (at 600 °C and 800 °C) samples (ion fluence: 7 × 1016 ions/cm2), where the disorder level is 0.95, which is close to the amorphization dose. The samples were characterized using optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman scattering techniques. AFM measurements indicate that blisters exfoliate at a depth of around 289 nm, where H ions result in maximum damage. Raman scattering results reveal the presence of vacancy-hydrogenated complex in the post-annealed samples. Raman mapping around blisters suggests that there is more internal stress around the periphery of blisters than at its centre. Internal pressure and stress inside the blisters are estimated using Föppl-von Karman's (FvK) theory of thin plates. The internal pressure decreases with the diameter of the blisters. FvK theory of thin plates has enabled the determination of a threshold stress of 0.06 GPa, describing the change from a tensile to a compressive stress state in the buckles, which leads to the exfoliation of blisters. [ABSTRACT FROM AUTHOR]

The principal effect controlling the oxygen affinity of vertebrate haemoglobins (Hbs) is the allosteric switch between R and T forms with relatively high and low oxygen affinity respectively. Uniquely among jawed vertebrates, crocodilians possess Hb that shows a profound drop in oxygen affinity in the presence of bicarbonate ions. This allows them to stay underwater for extended periods by consuming almost all the oxygen present in the blood-stream, as metabolism releases carbon dioxide, whose conversion to bicarbonate and hydrogen ions is catalysed by carbonic anhydrase. Despite the apparent universal utility of bicarbonate as an allosteric regulator of Hb, this property evolved only in crocodilians. We report here the molecular structures of both human and a crocodilian Hb in the deoxy and liganded states, solved by cryo-electron microscopy. We reveal the precise interactions between two bicarbonate ions and the crocodilian protein at symmetry-related sites found only in the T state. No other known effector of vertebrate Hbs binds anywhere near these sites. Crocodilians are ambush predators that possess haemoglobin with an allosteric switch between R (high oxygen affinity) and T (low oxygen affinity) forms strongly controlled by bicarbonate ions, a unique evolutionary feature that helps the animal to stay underwater for extended periods of time. [ABSTRACT FROM AUTHOR]

BACKGROUND: The development of efficient and green pretreatment pathway is of great significance for promoting biofuel production from lignocellulosic waste. The purpose of this work was to evaluate that iron ion‐catalyzed hydrogen peroxide pretreatment can be used as an environmentally friendly pretreatment way for bio‐jet fuel production using straw. RESULTS: The effects of iron ion‐catalyzed hydrogen peroxide pretreatment (Fe‐HP) on the enzymatic hydrolysis, fermentation and bio‐jet fuel production using straw were investigated. It was found that the iron ion‐catalyzed hydrogen peroxide pretreatment significantly improved the enzymatic hydrolysis and fermentation efficiency of straw biomass. Subsequently, the directional catalytic transformation of straw‐derived fermentation broth to bio‐jet fuels was achieved using a dual functional catalyst (HSAPO34/NiHBET). High conversion (94.9%) and good jet‐fuel selectivity (77.3%) were obtained in the conversion process of straw. On account of the biomass characterization and the analysis of reactive oxygen species during the Fe‐HP pretreatment, the role and mechanism of the Fe‐HP pretreatment was addressed. CONCLUSION: The Fe‐HP pretreatment can be used as an environmentally friendly pretreatment way for jet fuel production from straw biomass. Fe‐HP pretreatment increased sugar yield and sugar concentration during enzymatic hydrolysis, which was beneficial for subsequent fermentation and bio‐jet fuel production. The reactive oxygen species take a prominent role in the Fe‐HP pretreatment of lignocellulose. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

A systematic evaluation of deploying Ga x Ce y O z passivation layer (PL) on Si substrate subjected to postdeposition annealing in forming gas-oxygen-forming gas ambient at different temperatures (600–900 °C) was carried out. The inclusion of hydrogen and/or nitrogen ions, in addition to their attachment to oxygen vacancies and Si dangling bonds, has been reported. The attachment became more prominent at 600 and 700 °C while oppositely, the incoming oxygen ions acquired adequate energy to break the attachment at/beyond 800 °C. Therefore, it is conceivable that the Ga x Ce y O z PL annealed at/beyond 800 °C have attained a thicker interfacial layer (IL). The acquisition of a higher N ss has been attributed to the de-passivation of Si dangling bonds by the excessive hydrogen ions present at the interface. The potential of utilizing Ga x Ce y O z PL annealed at 700 °C as a PL for metal-oxide-semiconductor applications was inferred through a thorough electrical analysis conducted in this work. [ABSTRACT FROM AUTHOR]

A high-sensitivity pH sensor based on an AlGaN/GaN high-electron mobility transistor (HEMT) with a 10 nm thick Au-gated sensing membrane was investigated. The Au nanolayer as a sensing membrane was deposited by electron-beam evaporation and patterned onto the GaN cap layer, which provides more surface-active sites and a more robust adsorption capacity for hydrogen ions (H+) and hydroxide ions (OH−) and thus the sensitivity of the sensor can be significantly enhanced. A quasi-reference electrode was used to minimize the sensing system for the measurement of the microliter solution. The measurement and analysis results demonstrate that the fabricated sensor exhibits a high potential sensitivity of 58.59 mV/pH, which is very close to the Nernstian limit. The current sensitivity is as high as 372.37 μA/pH in the pH range from 4.0 to 9.18, under a 3.5 V drain-source voltage and a 0 V reference-source voltage. Comparison experiments show that the current sensitivity of the Au-gated sensor can reach 3.9 times that of the SiO2-gated sensor. Dynamic titration experiments reveal the pH sensor's ability to promptly respond to immediate pH variations. These findings indicate that this pH sensor can meet most application requirements for advanced medical and chemical analysis. [ABSTRACT FROM AUTHOR]

CO2, HCO3, SID, and total weak acids have been defined as pH's independent variables. However, according to Gamble, HCO3 should be equal to the difference between the sum of cations and the sum of anions besides HCO3. Therefore, if this mathematical expression is substituted for HCO3 in the Henderson-Hasselbalch equation, all independent variables of pH can be demonstrated. Our aim is to test this theory in this study. This prospective observational study was conducted between 2019 and 2020. All admitted patients to the intensive care unit who were >18 years old were included. Demographic data, blood gas parameters, albumin, magnesium, and inorganic phosphorus levels, and outcomes were recorded twice (at admission and at the 24th hour). The multivariate linear regression model was used to determine pH's independent variables. In the multivariate linear regression model, pH was significantly increased by each unit increase in Na, K, Ca, and Mg (mmol L-1). In contrast, pH was significantly decreased by each unit increase in CO2, Cl, lactate, albumin (g dL-1), inorganic phosphorus (mg dL-1), and the strong ion gap. Ten independent variables can accurately predict the changes in pH. For this reason, all ten independent variables should be separately evaluated when interpreting the acid-base status. With this understanding, all algorithms regarding acid-base evaluation may become unnecessary. [ABSTRACT FROM AUTHOR]

Simulation methods have received much attention across various fields in recent years. The rare-earth lutetium tantalate (LuTaO4) doped “Bismuth Oxide (Bi2O3) thin films were deposited onto polymer substrates using a SRIM program.” The SRIM program was used to calculate some physical characteristics of Bi2O3 films at energies between 1.0 MeV and 20 MeV. The “electronic and nuclear stopping powers” of LuTaO4, Bi2O3, C10H8O4, and LuTaO4/ Bi2O3/C10H8O4 samples were investigated. These findings show that rare earth doping may improve the performance of composite materials. The interaction of ion beams with matter can result in a wide variety of phenomena. The deposition of Bi2O3 films doped with LuTaO4 on C10H8O4 led to changes in the “electronic and nuclear stopping powers” and range in the materials. Published data were compared with the results obtained and the calculations parameters were provided. [ABSTRACT FROM AUTHOR]

Background: Mycobacterium tuberculosis (MTB) employs a variety of strategies to evade the host immune response, enabling its persistence and the development of tuberculosis. These evasion tactics involve thwarting lysosome formation, manipulating intracellular pH, and disrupting apoptosis and autophagy processes within host cells. Specifically, MTB interferes with lysosome acidification by modulating calcium ions (Ca2+), iron ions, and hydrogen ions (H+), creating an optimal environment for its survival within host cells. Furthermore, MTB inhibits host cell apoptosis and autophagy, critical defense mechanisms against intracellular pathogens. Understanding these immunological escape mechanisms is paramount for developing effective tuberculosis therapies. Future research should focus on targeting MTB evasion strategies to pave the way for innovative tuberculosis treatments. Conclusion: There is still a long road ahead of us to understand the immunological escape mechanism used by MTB. Over the past 50 years, numerous studies have looked into the immune response and the pathogenic processes of MTB. [ABSTRACT FROM AUTHOR]

Climatologies, which depict mean fields of oceanographic variables on a regular geographic grid, and atlases, which provide graphical depictions of specific areas, play pivotal roles in comprehending the societal vulnerabilities linked to ocean acidification (OA). This significance is particularly pronounced in coastal regions where most economic activities, such as commercial and recreational fisheries and aquaculture industries, occur. In this paper, we unveil a comprehensive data product featuring coastal ocean acidification climatologies and atlases, encompassing the fugacity of carbon dioxide, pH on the total scale, total hydrogen ion content, free hydrogen ion content, carbonate ion content, aragonite saturation state, calcite saturation state, Revelle factor, total dissolved inorganic carbon content, and total alkalinity content. These variables are provided on 1° × 1° spatial grids at 14 standardized depth levels, ranging from the surface to a depth of 500 m, along the North American ocean margins, defined as the region between the coastline and a distance of 200 nautical miles (∼370 km) offshore. The climatologies and atlases were developed using the World Ocean Atlas (WOA) gridding methods of the NOAA National Centers for Environmental Information (NCEI) based on the recently released Coastal Ocean Data Analysis Product in North America (CODAP-NA), along with the 2021 update to the Global Ocean Data Analysis Project version 2 (GLODAPv2.2021) data product. The relevant variables were adjusted to the index year of 2010. The data product is available in NetCDF (https://doi.org/10.25921/g8pb-zy76 , Jiang et al., 2022b) on the NOAA Ocean Carbon and Acidification Data System: https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0270962.html (last access: 15 July 2024). It is recommended to use the objectively analyzed mean fields (with "_an" suffix) for each variable. The atlases can be accessed at https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/synthesis/nacoastal.html (last access: 15 July 2024). [ABSTRACT FROM AUTHOR]

The physicochemical properties of high-molecular weight compounds based on N,N-diallyl-N′-acyllhydrazines were studied. Based on the results of thermal analysis it was established that sorbents are stable up to 160–210 °C; the destruction of the initial N,N-diallyl-N′-acyllhydrazines starts at lower temperatures. The stability of sorbents in various media, the values of static exchange capacities for hydrogen ions and hydroxide ions ( SEC H + and SEC OH − ), and isoelectric points of the surface were determined. Samples for further study of the rare earth metals sorption were selected. [ABSTRACT FROM AUTHOR]

Van Allen Probe observations indicate that whistler‐mode hiss waves below 1 kHz are absorbed at low altitudes near magnetic equator. The lowest cutoff frequency of equatorial hiss is close to the gyrofrequency of hydrogen ions. The lowest cutoff altitude of global hiss is extracted when its occurrence rate is equal to 0.005 on the plane of altitude (L in RE) and magnetic local time (MLT). By fitting the lowest cutoff altitude of global hiss, we constructed the empirical model of the lowest cutoff altitude of equatorial hiss under geomagnetically quiet (AE < 200 nT) and active (AE ≥ 200 nT) conditions. The enhanced substorm activities reduce the lowest cutoff altitude of hiss waves on the dawnside (MLT ∼ 1–5 hr), whereas the lowest cutoff altitude of the dayside hiss is nearly fixed at ∼1.1 RE (MLT ∼ 6–20 hr). From the dayside to the nightside (MLT ∼ 0–6 hr and 20–24 hr), the lowest cutoff altitude of equatorial hiss raises gradually from 1.1 RE to 1.4 RE. Plain Language Summary: Plasmaspheric hiss can cause the scattering loss of Earth's radiation belt electrons via wave‐particle resonant interactions and creates a slot region relatively safe for satellites. Thus, their spatial distribution is a key parameter controlling the dynamics of radiation belts. Although the outer boundary of hiss waves can be estimated with the empirical plasmapause location, there is no any empirical model to quantificationally describe their inner boundary. Here, based on the Van Allen Probe observations, we constructed empirical models to estimate the lowest cutoff altitude of global hiss under different geomagnetic conditions. The new empirical models provide an inner boundary for simulating the resonant interactions between hiss waves and high‐energy electrons. Key Points: The lowest cutoff altitude of global hiss is quantificationally examined with Van Allen Probes observations near the magnetic equatorThe lowest cutoff altitude of equatorial hiss is nearly fixed at L ∼ 1.1 on the dayside, but changes between L ∼ 1.1–1.4 on the nightsideNew empirical models are constructed to estimate the lowest cutoff altitude of global hiss under different geomagnetic conditions [ABSTRACT FROM AUTHOR]

Aqueous hydrogen ion batteries possess the advantages of sustainability, low cost, and high safety, which makes them an ideal choice for grid-level energy storage. Although some anions show strong interaction with the surface of some metal oxides, the effect of anions on the cation intercalation behavior and electrochemical activity is rarely reported. Herein, we report that anions in the electrolyte can greatly affect the electrochemical performance of anatase TiO2 in aqueous hydrogen ion batteries. The adsorption strength between the anatase TiO2 (101) surface and the anions was found to follow the order of SO42− > Cl− > NO3−. Experiments with theoretical calculations revealed that SO42− can promote the electrochemical performance of the anatase TiO2 anode for aqueous hydrogen ion batteries, while NO3− hinders the hydronium intercalation. This work can provide a new avenue for the design of high-performance aqueous batteries. [ABSTRACT FROM AUTHOR]

The practical application of aqueous Zn‐ion batteries (AZIBs) is hindered by the crazy Zn dendrites growth and the H2O‐induced side reactions, which rapidly consume the Zn anode and H2O molecules, especially under the lean electrolyte and Zn anode. Herein, a natural disaccharide, d‐trehalose (DT), is exploited as a novel multifunctional co‐solvent to address the above issues. Molecular dynamics simulations and spectral characterizations demonstrate that DT with abundant polar −OH groups can form strong interactions with Zn2+ ions and H2O molecules, and thus massively reconstruct the coordination structure of Zn2+ ions and the hydrogen bonding network of the electrolyte. Especially, the strong H‐bonds between DT and H2O molecules can not only effectively suppress the H2O activity but also prevent the rearrangement of H2O molecules at low temperature. Consequently, the AZIBs using DT30 electrolyte can show high cycling stability even under lean electrolyte (E/C ratio = 2.95 µL mAh−1), low N/P ratio (3.4), and low temperature (−12 °C). As a proof‐of‐concept, a Zn||LiFePO4 pack with LiFePO4 loading as high as 506.49 mg can be achieved. Therefore, DT as an eco‐friendly multifunctional co‐solvent provides a sustainable and effective strategy for the practical application of AZIBs. [ABSTRACT FROM AUTHOR]

Glycine silver nitrate (GSN) and fully deuterated GSN (FDGSN) form two isotopic polymorphs. The effect of full deuteration brought about the isotopic polymorph of GSN. In order to study the effect of partial deuteration on isotopic polymorphs, crystals of C-deuterated GSN (CDGSN) and N-deuterated GSN (NDGSN) were grown. The crystal structure of C deuteration was similar to FDGSN forming 2-dimensional polymeric structures extended along the c-axis. In CDGSN, the silver ion is mononuclear similar to that in FDGSN with no Ag-Ag coordination. N deuteration had similar crystal structure to that of GSN. The nitrate ion, the silver ion and the zwitterionic glycine form a three-dimensional network unlike the case in CDGSN. The silver ion is binuclear with Ag-Ag coordination similar to that in GSN. In both crystal structures, the silver ion has an oxidation state of +1. The Hirshfeld surface analysis of all the above structures was carried out using the X-ray data. The globularity parameter is similar in all the structures. For the entire complex, it is observed that FDGSN and CDGSN have similar values, which are lower than that of GSN and NDSN. The asphericity for the entire complex in the case of NDGSN and GSN is close to 0 indicating the isotropic nature whereas for FDGSN and CDGSN, it is near 0.36 indicating oblate nature. NDGSN and GSN have higher Ag···O interactions compared to that of CDGSN and FDGSN. NDGSN and GSN have Ag···Ag interaction, which is totally absent in CDGSN and FDGSN. Raman measurements showed the partial deuteration of the compounds. The lattice modes of GSN and NDGSN are similar, and FDGSN and CDGSN are similar. The C deuteration changes the coordination of the silver. In FDGSN and CDGSN, Ag ion coordinates to the hydrogen which is covalently bonded to carbon of zwitterionic glycine whereas in NDGSN and GSN, this coordination of Ag ion with hydrogen is absent. [ABSTRACT FROM AUTHOR]

The pickup process of newly ionized hydrogen (H) from the Martian extended exosphere represents an important H+ escape channel on Mars. It is generally believed that interplanetary (IP) shocks can accelerate the pickup ions and, in turn, affect the pickup process. However, the underlying processes inherent to the acceleration are not yet fully understood. Here, we concentrate on the dynamic processes involved in acceleration arising from IP shock compression. We examine two typical IP shock events characterized by a sudden increase in the average energy of upstream H+ pickup ions across the shock. The H+ pickup ions continuously enter the field of view of Supra-Thermal And Thermal Ion Composition or Solar Wind Ion Analyzer on board the Mars Atmosphere and Volatile EvolutioN spacecraft in a narrow angular range. Moreover, they correspond to a similar part of their respective ring distributions in velocity space. By comparing measured and theoretical H+ pickup ion energies, we attribute the more energetic H+ pickup ions to the enhanced convection electric field acceleration caused by the shock compression. An increase in the guiding center drift speed across the shock implies a higher escape rate of the H+ pickup ions. Furthermore, the pitch-angle scattering could facilitate the escape of the higher energy H+ pickup ions from Mars. The results may shed light on the understanding of the energization and escape of planetary pickup ions in the solar system. [ABSTRACT FROM AUTHOR]

The effect of collisions on the motion of magnetized ions in sheath and presheath plasma regions was investigated through the measurement of ion incident angle of a hydrogen ion at a graphite surface. The experiment was conducted in hydrogen and deuterium plasmas where the ion mean free path is 5–10 times larger than the ion gyro radius and with varying magnetic field angle ψ from 0° to 90° normal to the target surface. The hydrogen ions actively reacted with carbon, leading to the formation of conical tips with axes directed along the incident ion flow direction. The ion incident angle was measured from the etched graphite images taken by scanning electron microscopy. The measured angles were compared to those calculated using Ahedo's fluid magnetic sheath model. In addition, we adopted the nominal Bohm criterion at the electrostatic sheath edge due to the larger ion gyro radius than the sheath. The results show that the ion incident angle was inclined to the normal direction with respect to the magnetic field angle because of the effect of ion collisions on ion motion in the presheath. The collisional effect on the ion motion is drastic for an oblique magnetic field angle ψ > 85°. This study demonstrates that the collisional property of the ions is crucial to guide the ion motion in magnetic (pre)sheath and to determine the ion incidence angle at the surface, even in collisionless and weakly magnetized plasmas. [ABSTRACT FROM AUTHOR]

This study offers a review of published data on DNA double strand break (DSB) repair kinetics after exposure to ionizing radiation. By compiling a database, which currently includes 285 DNA DSB repair experiments utilizing both photons and ions, we investigate the impact of distinct experimental parameters on the kinetics of DNA DSB repair. Methodological differences and inconsistencies in reporting make the comparison of data generated by different research groups challenging. Nevertheless, by implementing filtering criteria, we can compare repair kinetics obtained with normal and tumor cells derived from human or animal tissues, as well as cells exposed to photons or ions ranging from hydrogen to iron ions. In addition, several repair curves of repair deficient cell lines were included. The study aims to provide researchers with a comprehensive overview of experimental factors that may confound results and emphasize the importance of precise reporting of experimental parameters. Moreover, we identify gaps in the literature that require attention in future studies, aiming to address clinically relevant questions related to radiotherapy. The database can be freely accessed at: https://github.com/weradstake/DRDNA. [ABSTRACT FROM AUTHOR]

To achieve a highly reliable IGZO transistor, silicon nitride thin film, as a passivation layer, has been extensively investigated in recent years, mainly due to readily available fabrication, along with good barrier performance. Here, we found out that larger amount hydrogen residuals was observed in the PECVD deposited SiNx passivation layer, more stable the IGZO oxide device exhibited, which is abnormal behavior to that commonly known in the literatures. Given that FT‐IR and SIMS analysis with various controlled SiNx thin film upon different deposition conditions, the plasma parameters such as power, pressure, source gas ratio could affect hydrogen ion diffusivity into the IGZO layer during the deposition and the chemical composition of hydrogen residuals in the resulting SiNx layer, which is more dominant, rather than absolute hydrogen contents itself, to the initial electrical properties as well the stability of the IGZO transistor device. [ABSTRACT FROM AUTHOR]

Vanadium-based oxides are considered potential cathode materials for aqueous zinc ion batteries (AZIBs) due to their distinctive layered (or tunnel) structure suitable for zinc ion storage. However, the structural instability and sluggish kinetics of vanadium-based oxides have limited their capacity and cycling stability for large-scale applications. To overcome these shortcomings, here a porous vanadium-based oxide doped with zinc ions and carbon with the molecular formula ZnV2O4@C (ZVO@C) as the cathode material is synthesized by the pyrolysis of a bimetallic MOF precursor containing Zn/V. This electrode demonstrates a remarkable specific capacity of 425 mA h g−1 at 0.5 A g−1 and excellent cycling stability with about 97% capacity retention after 1000 cycles at 10 A g−1. The excellent electrochemical performance of ZVO@C can be attributed to more reaction active sites and the faster reaction kinetics for zinc ion diffusion and storage brought about by the porous layered spinel-type tunnel structure with high surface area and massive mesoporosity, as well as the enhanced electron transport efficiency and more stable channel structure achieved from the doped conductive carbon. The reaction mechanism and structural evolution of the ZVO@C electrode are analyzed using X-ray diffraction and X-ray photoelectron spectroscopy, revealing the formation of a new phase of ZnxV2O5·nH2O during the first charge, which participates in reversible cycling together with ZVO@C during the charging and discharging processes. Moreover, the energy storage mechanism is revealed, in which zinc ions and hydrogen ions jointly participate in intercalation and extraction. The present study demonstrates that constructing composite vanadium-based oxides based on bimetallic organic frameworks as precursor templates is an effective strategy for the development of high-performance cathode materials for AZIBs. [ABSTRACT FROM AUTHOR]

An electrocatalyst with ultra-small PtCo single atom alloy species evenly dispersed on nitrogen-doped ultra-thin carbon nanosheets (PtCo SAA/NC) was designed. The introduction of single-atom Pt not only maximizes the atomic utilization efficiency of Pt species, but also synergistically enhances the charge transfer characteristics of Co cluster surfaces, thereby increasing the migration and evolution rate of hydrogen ions. The PtCo SAA/NC catalyst exhibits a Tafel slope of 42 mV dec−1 and a low overpotential of 45 mV at 10 mA cm−2 in 0.5 M H2SO4 solution. [ABSTRACT FROM AUTHOR]

Electron cyclotron resonance ion source (ECRIS) as the front-end for the neutral beam injection (NBI) system has production potential of hydrogen ion beam in tokamaks. In this article, two methods are hired to evaluate the plasma ion fractions: H + , H 2 + and H 3 + with respect to the ECRIS operating parameters. The methods are matured by utilizing 28 important volume and surface collisions processes. We encrypted a global 0D numerical model (GM) based on solving the nonlinear equations of plasma species as the first method. Next, a 3D plasma simulation (PS) is applied through the finite element method (FEM) by COMSOL Multiphysics. Then, the results are compared to the experimental data. • Two methods have been compared for calculating plasma characteristics. • 0D global model is based on solving the nonlinear population balance equations. • 3D plasma simulation by applying COMSOL Multiphysics is based on fluid model. • Output results of the methods are in a good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Aqueous fluoride ion batteries (FIBs) have garnered attention for their high theoretical energy density, yet they are challenged by sluggish fluorination kinetics, active material dissolution, and electrolyte instability. Here, we present a room temperature rocking‐chair aqueous FIBs featuring KOAc‐KF binary salt electrolytes, enabling concurrent fluorination and defluorination reactions at both cathode and anode electrodes. Experimental and theoretical results reveal that acetate ions in the electrolyte compete with fluoride ions in hydrogen bonding formation, weakening the excessively strong solvation between H2O and F− ions. This results in the suppression of detrimental HF formation and a reduced desolvation energy of F− ions, enhancing the electrochemical reaction kinetics. The bismuth‐based cathode exhibits direct conversion in the optimized electrolyte, effectively suppressing the detrimental disproportionation reactions from Bi2+ intermediates. Additionally, zinc anode undergoes a typical fluorination process, forming solid KZnF3 as the electrode product, minimizing the risks of hydrogen evolution. The proposed aqueous FIBs with the optimized electrolyte demonstrate high discharge capacity, long‐term cycling stability and excellent rate capabilities. [ABSTRACT FROM AUTHOR]

Inspired by the observations suggesting that at altitudes of about 1000 km the interaction between solar wind streams and Venus' ionosphere plasma leads to ions acceleration and outflow, the influence of different solar wind physical parameters, such as densities, temperatures and initial streaming velocities, has been studied. The ionosphere plasma system consists of two positive ion populations O+, H+ and electrons along with the solar wind streaming protons and electrons. We calculated the generated oxygen and hydrogen ions flow velocities and the electric fields. In addition, we calculated rough estimates for the escaping flux of ion populations (O+, H+) from Venus' ionosphere and compared them to observations. To a large extent, we found that the estimates match. We also discuss the relevance of ionospheric ion acceleration and outflow from Venus' upper. [ABSTRACT FROM AUTHOR]

The method of expulsion of hydrogen negative ions in the axial direction by a negative space charge formed in the plasma of Penning discharge with metal hydride cathodes is discussed. The plasma is produced on hydrogen, which is stored in metal hydride cathodes and injected locally into the discharge cell without any external gas supply due to ion current impact from plasma. The process of nonequilibrium desorption resulted in high vibrational excitation of H2 molecules, which greatly increases the efficiency of H− ion production. The method of efficient expulsion of H− ions depends on the external magnetic field. At a high magnetic field, it is performed by the supply of negative electric bias of the opposite cathode, but at a low one, H− ions are pushed out by the negative space charge of the anode layer, which expands toward the axis. The impact of both methods is considered in the case of DC discharge and in pulsating regime implementation. [ABSTRACT FROM AUTHOR]

The geometries, energies, and vibrational frequencies of various isomers of HVO42−(H2O)n, n = 0–6 are calculated at various levels up to MP2/6−31 + G*. These properties are studied as a function of increasing cluster size. The calculations predict the vibrational frequencies, the full-widths at half-height, and a strong temperature and solvent dependence of the V–O(H) stretching and VOH bending vibration. [ABSTRACT FROM AUTHOR]

Cooperative effect as well as interfacial engineering are crucial factors for the development of electrochemical hydrogen evolution reaction (HER). Keeping this aspect in mind, a novel mixed micellar film using dodecylamine molybdenum (III) trichloride (MoDDA(I)) and dodecylamine palladium (II) dichloride (PdDDA(I)) was fabricated for electrochemical HER. The mixed micellar film was characterized by various instrumentation techniques to explore its structure and composition i.e. FESEM, AFM, FTIR. In addition, XPS was inserted to understand the underlying mechanism before and after electrolysis. The fabricated surface of mixed micelles was found to be hydrophobic. The efficiency of mix-metallomicelles as an electrocatalyst was checked in acidic media for electrochemical HER. The prepared reverse micellar film was activated by polarization cycles due to the in-situ reduction of metallic components. These metallic cores act as active centers for electrocatalytic HER. The HER activity of Mo-PdDDA(I) was found to be superior as compared with Pt/C. The prepared mixed micelles displayed 29.2 mV dec−1 Tafel slope. First, Mo and Pd based mixed micelles were prepared using a one-pot method. Benefiting from the role of organic media, MoDDA(I) and PdDDA(I) were able to orient in the form of reverse micelles. Wherein, Mo and Pd metal ions are present in the core of the micelles. The excellent activity exhibited by the formation of mix-metallomicelles, a synergic effect between metal ions, and interfacial engineering introduced by the surfactant moiety, which in turn facilitates the adsorption and activation of hydrogen ions on the electrode surface. Additionally, the mixed micelles provide a high surface area for the electrochemical reaction and enhance the conductivity of the electrode. [Display omitted] • Pd and Mo metallo-micellar assemblies were used for hydrogen generation. • These metallic cores act as active centers for electrocatalytic HER. • HER activity of Mo-PdDDA(I) was found to be superior as compared with Pt/C. • Synergic effect between metal ions, interfacial engineering by surfactant were key factors. • Excellent activity by metallomicelles was due to metals (Cooperative) and surfactant (interfacial). [ABSTRACT FROM AUTHOR]

Rhizosphere pH determines nutrient bioavailability, but this pH is difficult to measure. Standard pH tests require adding water to growth media. This dilutes hydrogen ion activity and increases pH. We used a novel, in situ, pointed-tip electrode to estimate rhizosphere pH without dilution. Measurements from this electrode matched a research-grade pH meter in hydroponic nutrient solutions. We then compared measurements from this electrode to saturated paste and pour-through methods in peat moss, coconut coir, and pine bark. The pointedtip electrode was unable to accurately measure pH in the highly-porous pine bark media. Adding deionized water to the other media at container capacity using the saturated paste method resulted in a pH that was 0.59 ± 0.30 units higher than the initial in situ measurement at the top of the container. This increase aligns with established solution chemistry principles. Measurements of pH using the pour-through method were 0.38 ± 0.24 pH units higher than in situ measurements at the bottom of the container. We conclude that in situ pH measurements are not subject to dilution and are thus more representative of the rhizosphere pH than the saturated paste and pour-through techniques. [ABSTRACT FROM AUTHOR]

Negative hydrogen ion sources (NHISs) based on surface production with cesium (Cs) seeded can fulfill the demanded parameters for neutral beam injection systems for ITER. In this study, the Global Model for Negative Hydrogen Ion Source based on volume-produced H − ions is developed to include surface-produced H − ions and is validated against experimental data obtained in a planar inductively coupled plasma discharge used for study of Cs effect on H − production. The H − density predicted by the model decreases three times with surface work function from 2.1 to 4.5 eV, achieving good agreement with the experimental results, as surface conversion yield of particles to H − ions shows exponential decline with surface work function. The model predicts the rise in neutral gas temperature remarkably enhances surface production but reduces volume production of H − ions, because of increase in surface conversion yield of H atoms to H − ions and in electron temperature, respectively. The dependences of H − production on surface work function and neutral gas temperature are analyzed by evaluating creation rates of the H − ions from different reaction pathways. The developed model can be applied for prediction of H − production in NHISs and ultimate parameter optimization of negative ion beams for fusion reactors. [ABSTRACT FROM AUTHOR]

The article discusses a new efficient technology for the preparation of additional water in heating networks. According to the technology, additional water is prepared through the process of cationization using polyfunctional sulfonated coal cationites regenerated with a stoichiometric amount of salt. The research was carried out according to a continuous flow scheme. To obtain accurate results, a laboratory setup was prepared by approximating the height of the cationite and the average diameter of its particles to the required values relative to the diameter of the filter (d : D < 1 : 20) by adjusting the operating regime of the filter closer to industrial conditions. The regeneration regime of the cationite is selected in such a way that the amount of salt in the filtrate during water treatment does not exceed 3–6% of the amount of salt absorbed by the cationite. The main goal of the newly developed technological regime is to reduce the specific consumption of salt during regeneration, increase the exchange capacity of the cationite, and improve both the economic and ecological indicators of the process. As a result of the research, it can be concluded that the exchange capacity of the cationite varies within the interval of 7–20% under the influence of selected factors, and when the specific consumption of salt is increased from 8 to 16 kg/m3, the exchange capacity of the cationite approximately doubles. It should be noted that when the carbonate index in the treated water increases due to the presence of carbonate and hydrogen ions, the degree of water softening increases. However, the rapid rise of the carbonation value in the filtrate increases the average value of the carbonate index and leads to fouling of the filter, which results in a lower exchange capacity of the cationite compared to the mentioned values. It should be emphasized that depending on the values of alkalinity and specific consumption of the regenerant during the process, the filtrate volume of the treated water exiting the filter becomes 2–12% of the total volume and is characterized by saltiness. The salinity in the filtrate is neutralized by the buffer filter. [ABSTRACT FROM AUTHOR]

Neutral beam injection systems as foreseen for ITER use radio-frequency (RF) ion sources at low pressure, where negative hydrogen ions are mainly produced via surface conversion of neutral atoms and positive ions at a plasma facing grid (PG). Up to now there is only limited knowledge about how fluxes and directed velocities of the positive ions are affected by external parameters such as power, pressure and the horizontal magnetic filter field which causes plasma drifts and vertical asymmetries in the vicinity of the PG. For this reason a combined Mach-Langmuir-probe diagnostic is used at multiple positions in the expansion and close to the extraction system in the prototype RF ion source (1/8 of the full ITER ion source size) to measure the positive ions directed velocity and flux as well as the plasma parameters simultaneously. With increasing RF power the flux towards the PG is found to increase linearly, its magnitude being controlled by the plasma density. Towards ITER-relevant pressures the ion flux decreases, in contrast to the directed velocity, which increases non-linearly, reaching around 5 km s−1 at a pressure of 0.3 Pa. The magnetic filter field is discovered to strongly bent down the ion flow in front of the PG. As a result, the ions at the lower half of the PG flow almost exclusively parallel to it, wherefore the flux which impinges onto the lower PG half is reduced by around one order of magnitude. [ABSTRACT FROM AUTHOR]