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This paper studies full-scale gas neutron tube modeling, including the following processes: gas discharge combustion in a Penning ion source, particle motion in an ion optical system, and modeling the in-target processes, such as sputtering, diffusion, thermal desorption of hydrogen isotopes, and nuclear reactions. Plasma modeling in quadrupole electric and axial magnetic fields was based on the electrostatic particle-in-cell method with molecular kinetic processes. The TechX Vsim software package was used. The neutron tube element sputtering by ions was simulated using SRIM/TRIM software based on Monte–Carlo methods. The OpenFOAM, as an open integrated platform for numerical simulation in continuum mechanics, was used to calculate the hydrogen thermal desorption activated by ion irradiation. The time-dependent neutron yield modeling was performed using the Geant4 software based on Monte–Carlo methods with CHIPS-TPT VNIIA-developed library. In addition, an experimental study of a gas neutron tube with a Penning ion source was conducted here as well. Details are given on the experiment and measurement technique used in this study. The operating characteristics for the gas neutron tube, including amplitude-time characteristics of current flashes (discharge and extraction currents), were determined. The neutron flux dependencies on the discharge current at various accelerating voltages were also obtained. Finally, a comparison between the experimental and calculated results is presented. [ABSTRACT FROM AUTHOR]

This second paper in a series of two describes the chirped-pulse ice apparatus that permits the detection of buffer gas cooled molecules desorbed from an energetically processed ice using broadband mm-wave rotational spectroscopy. Here, we detail the lower ice stage developed to generate ices at 4 K, which can then undergo energetic processing via UV/VUV photons or high-energy electrons and which ultimately enter the gas phase via temperature-programmed desorption (TPD). Over the course of TPD, the lower ice stage is interfaced with a buffer gas cooling cell that allows for sensitive detection via chirped-pulse rotational spectroscopy in the 60–90 GHz regime. In addition to a detailed description of the ice component of this apparatus, we show proof-of-principle experiments demonstrating the detection of H2CO products formed through irradiation of neat methanol ices or 1:1 CO + CH4 mixed ices. [ABSTRACT FROM AUTHOR]

The annealing properties of open spaces in 90-nm-thick SiO2 deposited from tetraethylorthosilicate (TEOS) using plasma-enhanced chemical vapor deposition (PECVD) were studied with monoenergetic positron beams. From the lifetime of positronium (Ps) and an empirical model assuming a spherical open space, the mean diameter of open spaces was estimated to be 0.45 nm for PECVD-SiO2 before annealing. In the annealing temperature range below 350 °C, the size of the open spaces and their concentration increased as the temperature increased. Because initial water desorption from PECVD-SiO2 occurred in this temperature range, the observed increases in the size and concentration of spaces were attributed to the detrapping of water from such regions. Above 400 °C annealing, Ps formation was suppressed due to carrier traps introduced by the desorption of gas incorporated during TEOS decomposition. The size of the open spaces reached its maximum value (0.61 nm) after 800 °C annealing and started to decrease above 900 °C. After 1000 °C annealing, although the size of the spaces was close to that in thermally grown SiO2, their concentration remained low, which was attributed to residual impurities in the SiO2 network. [ABSTRACT FROM AUTHOR]

Thermal driven desorption of surface impurities is probed based on coupled Monte Carlo–heat flow–molecular dynamics simulations. Such adsorbates can lead to plasma formation during the operation of high-power microwave systems with various negative outcomes and so need to be curtailed. Our study attempts to obtain temperature thresholds for desorbing different surface contaminants such as C2, O2, CO, and CO2. The results show that carbon-based adsorbates on copper (chosen as an example anode material) could be ejected at a relatively modest surface temperature of 650 K. On the other hand, reactive species such as oxygen are very stable due to their large cohesive energies. Our calculations further suggest the benefit of using a platinum coating layer, as the noble metal is robust with strong resistance to oxidation. [ABSTRACT FROM AUTHOR]

We have developed an experimental and analytical setup for thermal desorption spectroscopy of solid water films on surfaces. We obtain the coverage-dependent desorption kinetics of water molecules from a well-defined ultra-thin alumina/NiAl(110) surface in the coverage range of 0–2 monolayers. We use a novel deconvolution technique to eliminate the pumping delay of water vapor in the vacuum system, which has previously hindered the accurate estimation of desorption kinetic parameters, such as activation energy and pre-exponential factor. The coverage-dependent Arrhenius analysis reveals that the desorption activation energy decreases with increasing coverage in the sub-monolayer range, indicating that the water–water interaction is not attractive. We also find that the pre-exponential factor for the second layer is higher than that for the sub-monolayer. We explain this difference in terms of transition state theory and propose that entropic effects play a significant role in water desorption kinetics. [ABSTRACT FROM AUTHOR]

Microplastics act as a vector for toxic trace metals and their surface complexation mechanisms under different environmental conditions are poorly understood. The present study evaluates the interaction mechanisms of pristine and aged polyethylene (PE) microplastics with Pb2+ in water environments in the presence of NaNO3 and humic acid (HA). The influence of pH, contact time, and concentration of Pb2+ on the sorption performances of PE microplastics have also been examined at different ionic strengths (0.001–0.1 M NaNO3), pH (2–9), reaction time (48 h), Pb2+ loading concentrations (1–25 mg L−1), and HA concentrations (0.5–2.5 mg L−1). The Pb2+ adsorption onto both pristine and aged microplastic showed a gradual increase with increasing pH, reaching maximum adsorption at around pH 5–6. Adsorption of Pb2+ onto both PE microplastics decreased at higher ionic strengths and increased at higher HA concentrations suggesting the possible hydrophobic and electrostatic interactions between microplastics and Pb2+ ions. Adsorption kinetic data for pristine PE microplastics were well described by fractional power model indicating time-dependent adsorption, whereas aged PE showed rate-limiting chemisorption by fitting with a pseudo-second-order kinetic model. Isotherm equilibrium data for pristine PE microplastics fitted well for the Freundlich model implying favourable physisorption on the heterogeneous surfaces. Both Hill and Freundlich models were the best-fitted models for aged PE microplastics suggesting the involvement of cooperative multilayer physisorption. Desorption of PE microplastics-bound Pb2+ was greatly influenced by the solution pH. The ascertaining facts elucidated the vector potential of PE microplastics for Pb2+, impacting their migration and destination in water systems where the adsorption could be influenced by the pH, ionic strength, and dissolved organic matter of the water system. [ABSTRACT FROM AUTHOR]

Determining worker exposure to hazardous volatile organic compounds (VOCs) in air at levels exceeding the Permissible Exposure Limits and Recommended Exposure Limits established by the U.S. federal agencies of Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH), respectively, will continue to be an important part of environmental and occupational health risk assessments. The purpose of this work was to develop a reliable analytical method for rapid and on-site assessments of occupational VOC exposures using field-capable thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) instrumentation (i.e. the HAPSITE® ER). The experiments involved in this study included determining TD-GC-MS parameters suitable for efficient analyte separation and quantitation on the HAPSITE® ER, determinations of analyte mass loadings that cause mass spectrometer detector saturations, generation of calibration curves, estimations of the limits of detection (LODs) and quantification (LOQs), as well as desorption efficiency and relative response factor repeatability. The LODs using Carbopack™ B and Tenax® TA sampling media were estimated and ranged from 0.2–1.9 ng and 0.045–0.3 ng, respectively. The LOQs using Carbopack™ B and Tenax TA sampling media were estimated and ranged from 1.0–6.3 ng and 0.2–1.1 ng, respectively. We have developed a reliable analytical method for chloroform, benzene, trichloroethylene, and heptane using field-portable HAPSITE® ER instrumentation and Tenax® TA sorbent media. Reliable and accurate methods were developed for chloroform and trichloroethylene using Carbopack™ B sorbent media, however, this particular sorbent hadlow desorption efficiency and insufficient repeatability in relative response factors for many analytes. Our current and ongoing work in determining the uptake rates for analytes on Tenax® TA sorbent media will make the methods described herein applicable for on-site occupational VOC exposure assessments of chloroform, benzene, trichloroethylene, and heptane using either passive or active air sampling techniques. [ABSTRACT FROM AUTHOR]

Ultrasound has been succesfully and frequently used in many adsorption/desorption processes recently, since its beneficial effects on adsorption/desorption have been seen in scientific studies. The main positive effects can be listed as causing many micro-cracks on the solid surface, increasing the mass transfer rate and the surface area of reactants, and causing many positive mechanical effects, such as cleaning the surfaces of solid reactants or catalyst particles in solid-liquid systems. This review summarises ultrasound-assisted adsorption/desorption researches such as ultrasound-assisted prepared adsorbent for the removal of heavy metal cations from aqueous solutions, decolourisation and COD reduction of dye solutions, ultrasound-assisted zeolitisation of fly coal ash, etc. There are also some studies in which ultrasound power has been used for desorption instead of mixing and desorption by ultrasound is seen as an alternative method for adsorbent regeneration. In addition, in current review, the theoretical fundamentals of ultrasound-assisted adsorption/desorption procedures were explored briefly and the effect of ultrasound on adsorption isotherm and adsorption/desorption kinetics was also discussed. [ABSTRACT FROM AUTHOR]

The present investigation was targeted to remove toxic heavy metal lead (Pb(II)) from synthetic solution with ultra-sonicated turmeric leaves powder (UTLP) as sorbent. The responsible functional groups for adsorption of Pb(II) onto UTLP were investigated using Fourier Transform Infrared (FTIR) spectroscopy, and the adsorption was confirmed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS) analysis. The Central Composite Design (CCD) method was used to scrutinise the effective parameters. Based on the optimisation results, the maximum % biosorption (97.36) of Pb(II) was attained under optimum conditions of pH: 4.92, biosorbent dosage (BD): 0.44 g and initial solution concentration (ISC): 37.93 mg/L. The experimental findings were fitted with Langmuir and Freundlich and Temkin isotherms. Sequel to isotherm data, the Freundlich model gave good fit with R2 = 0.99 and a maximum adsorption capacity of 36.49 mg/g. The pseudo-second-order model was found to be the most significant for kinetic data analysis. The thermodynamic parameters such as Gibb's energy change (∆G0), enthalpy change (∆H0) and entropy change (∆S0) were estimated, and it was found that the process was spontaneous and endothermic in nature. Furthermore, the desorption study was conducted with 0.1 N HNO3 to estimate the ease of regeneration behaviour of UTLP. Conclusively, the results revealed that UTLP is prominent and cheap biosorbent for removal of Pb(II) from aqueous medium. [ABSTRACT FROM AUTHOR]

In recent years, abnormal CO gas overruns have often occurred in coal mining workings. CO overruns were thought to be caused by the underground blasting work or spontaneous combustion of coal seams; however, minimal attention has been given to the causes of the desorption and release of adsorbed CO in the coal seams. Additionally, insufficient research has been conducted on the generation, distribution and adsorption and desorption characteristics of protogenetic CO in coal seams. Therefore, a self-built comprehensive testing system for coal seam adsorption and desorption was used to study the characteristics of the depressurization desorption and thermal desorption of coal with different degrees of metamorphism during coal seam mining. The results showed that under isothermal conditions, the amount of CO adsorption and desorption of coal samples increased with increasing pressure; under temperature rise conditions, the gas adsorption-desorption was in a dynamic equilibrium process under certain conditions. When the temperature increased, the equilibrium was beneficial to the desorption direction. The initial temperature range of CO production at different equilibrium pressures was 45–55°C. With increasing pressure, the initial temperature point of CO gas production moves forward and was significantly lower than the initial temperature of coal spontaneous combustion. Our research results further supplement the source of underground protogenetic CO gas and provide theoretical support for the accurate prediction of CO coal spontaneous combustion. [ABSTRACT FROM AUTHOR]

Cationic species, previously detected from ion‐induced desorption of solid methane by plasma desorption mass spectrometry (PDMS), and neutral species, are investigated using high‐level ab‐initio approaches. From a set of 25 cationic and 26 neutral structures belonging to CnH2 (n = 2–6) families, it was obtained the energy, rotational constants, harmonic vibrational frequency, charge distribution and excitation energies. The ZPVE‐corrected energies, at CCSD(T)‐F12; CCSD(T)‐F12/RI/(cc‐pVTZ‐F12, cc‐pVTZ‐F12‐CABS, cc‐pVQZ/C) (n = 2–5) and CCSD(T)/cc‐pVTZ (n = 6) levels, reveal that the topology of the most stable isomer vary with n and the charge. Out of 674 harmonic frequencies, those with maximum intensity are generally in the 3000–3500 cm−1 range. Analysis of 169 vertical transition energies calculated with the EOM‐CCSD approach, suggest three C6H2 species as potential carriers of the diffuse interstellar bands (DIB). Systematic comparison of properties between neutral and cationic species can assist in the structural description of complex matrices. [ABSTRACT FROM AUTHOR]

After the slickwater fracturing method is adopted, a portion of the slickwater remains in the reservoir, impacting shale gas production. To address this limitation, shale samples from the Longmaxi Formation were soaked and washed with varying concentration of polyacrylamide in slickwater under different pressures to simulate the flowback process following slickwater fracturing. The effects of slickwater on methane adsorption, desorption, and diffusion in shale were examined through isothermal adsorption experiments, while the evolution of shale pore structure was assessed using low-temperature nitrogen adsorption experiments. Results indicate that slickwater adheres to the surfaces of microcracks and macropores, creating new small pores and increasing the specific surface area and pore volume of macropores with sizes exceeding 5 nm. Slickwater may also block pore throats, causing some open or semi-open pores to become closed, thereby reducing the accessible specific surface area and pore volume and hindering the adsorption, desorption, and diffusion of methane. At a pressure of 9 MPa, treatment with 0.7% slickwater reduces the Langmuir volume to 40% of that of the original shale, while the diffusion coefficient decreases to 47% of its original value. Furthermore, as soaking pressure or concentration increases, the hysteresis of methane desorption in shale initially decreases before subsequently increasing. The findings of this research provide theoretical guidance for the further enhancement of shale gas development. • The effect of different concentrations of slickwater on gas adsorption, desorption, and diffusion. • The effect of slickwater under different external pressures on gas adsorption, desorption, and diffusion. • The effect of slickwater on pore structure of shale. • The effect mechanism of slickwater residue on gas adsorption, desorption, and diffusion. [ABSTRACT FROM AUTHOR]

In the context of the energy transition and in order to fully manage the integration of renewable and/or low-carbon gases into the gas mix, these new renewable gases need to be characterized, including volatile organic compounds (VOCs) at trace levels that may have an impact on different stages of the gas chain event at low concentrations. This study focuses on sampling because it is the first step in any method for analyzing trace VOCs and its careful execution is essential to ensure reliable results even if the on-site conditions can be variable, such as the external temperature. The stabilization time, the effect of external temperature, and the impact of using an intermediate sample cylinder prior to transfer to tubes were hence studied in the laboratory using a standard gas mixture representative of renewable gases. The latter was also studied using a real sample. To perform this study, VOCs were sampled in Tenax® TA tubes and then analyzed by thermal desorption hyphenated to comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry. The results showed that 45 min were required to stabilize the sampling system and that external temperature had little influence, limited to the heaviest compounds. Finally, the use of a cylinder to temporarily collect gas prior to transfer to tubes led to a loss of compounds, particularly when the cylinder was stored before the transfer. [ABSTRACT FROM AUTHOR]

The research focuses on desalting and regenerating wastewater using membrane capacitive deionization (MCDI) systems with Prussian blue analog and activated carbon electrodes in batch experiments. The experimental results show that the optimized operational parameters for achieving superior deionization regeneration performance in membrane capacitors comprise a voltage magnitude of −1.6 V, a desorption flow rate of 30 mL min−1, and an electrode regeneration duration of 25 min. The MCDI system achieves a desorption amount of 45.87 mg g−1, a remarkable regeneration rate of 99.23 % under the optimized operating conditions. The MCDI system demonstrates a desorption amount and regeneration rate that are 22.56 mg g−1 and 17.47 % higher, respectively, compared to the traditional capacitive deionization system. [ABSTRACT FROM AUTHOR]

The fermentation of whole slurry favors the increase in ethanol titers and minimizes water consumption. However, inhibitors accumulate in the liquid fraction pretreatment, reducing fermentation performance. In order to find a way out, the present study proposed an integration between cloud point extraction (CPE) and ethanol production using fiber of green coconut (GCF) as substrate. Triton X-114 was used to detoxify the liquid fraction from acid pretreatment, and optimal operating conditions were obtained by mathematical modeling. The effects of the residual surfactant from the dilute phase of CPE were analyzed in cellulase adsorption tests, enzymatic hydrolysis, and fermentation of acid-pretreated GCF. CPE promoted high removal of furans (86.23–100%) and phenolic compounds (22.79–75.15%), while the sugars migrated to the dilute phase. A neural network model coupled with a genetic algorithm obtained an optimal condition of 2.38% Triton X-114, temperature of 42 °C, pH of 4.3, and 0.55% sodium chloride. The incubation with the CPE dilute phase increased the residual activity from 25.1 to 50.1% and increased the cellulosic conversion from 32.28 to 41.15%. CPE-saccharification and simultaneous fermentation integration boosted the ethanol production to 12.40 g/L, while the untreated whole slurry reached only 6.29 g/L. Because of these results, the CPE emerges as a promising alternative to favor the full use of sugars from lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

Background: The effective extractives of Tetrastigma hemsleyanum (T. hemsleyanum) are useful, but this plant was not fully utilized in rural China. In this study, flavonoids from the aerial parts of T. hemsleyanum were extracted, and the purification method and the antioxidant capability were explored. Purpose: This study is to explore the optimized purification method and the biological capability of the total flavonoids extracted from T. hemsleyanum. Materials and Methods: The optimal extraction conditions were determined by single-factor and Box-Behnken design experiments. The antioxidant activities were assessed by analyzing their capability to scavenge 2,2-diphenyl-1-picrylhydrazyl and OH free radicals. Results and Discussion: The optimal conditions for the extraction of the total flavonoids were as follows: ethanol volume fraction 60%, liquid-to-material ratios 35:1 mL/g, temperature 45℃, and time 85 min. The extraction rate of the total flavonoids was (3.59 ± 0.03)%. NKA-9 is an ideal macroporous resin for purification. The optimized purification process conditions of flavonoids were mass concentration of adsorption solution 1.50 mg/mL, pH value of adsorption solution 4.0, sample loading flow rate 2 BV/h, ethanol volume fraction in desorption process 60%, desorption flow rate 2 BV/h and elution volume 4 BV. After crude extracts were purified by NKA-9 macroporous resin, the content of the total flavonoids enhanced from (21.76 ± 0.18)% to (58.92 ± 0.22)%. The results of the experiments for antioxidant activity showed that the half maximal inhibitory concentration (IC50) values of the purified flavonoids extracted were 33.1and 42.7 µg/mL, respectively. Conclusion: The results of this study indicated that the flavonoids in T. hemsleyanum have good antioxidant activity in vitro and deserve exploring in further pharmacological studies. [ABSTRACT FROM AUTHOR]

Coal mining can pose safety risks as mining stress and adsorption-desorption damage the coal in front of the working face. To address this, a damage model under the coupled influence of mining stress and adsorption-desorption was proposed by incorporating statistical damage mechanics and the effective stress principle. The method for determining model parameters was provided, and the model was validated through triaxial compression tests on coal containing methane. The model parameters were qualitatively analyzed, and the impact of parameters on the deformation and damage evolution of coal was also examined. The residual strengths of coal determined by previous classical models and the proposed damage model under various confining pressures were compared. The results mainly show that coal containing methane has distinct stages during triaxial compression, including compaction, elastic deformation, yield, strain softening, and residual deformation. The proposed damage model accurately tracks deformation and damage in a coal containing methane at varying confining pressures. An increase in Weibull distribution parameters causes peak stress and damage accumulation to start at a higher strain. Furthermore, a higher correction coefficient of residual strength results in a faster stress drop rate but lower residual strength of coal after peak stress. The proposed damage model accurately predicts the residual strength of coal under various confining pressures. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the operating characteristics of a chemisorption heat pump. 1-D transient model of a chemisorption heat pump was developed, for which an analysis of four alternating modes of operation was performed. The performance was analyzed with respect to the operating time of the adsorption and desorption operation modes during alternating operations, and the results showed that the cooling capacity has an optimum point depending on the operating times. It was also confirmed that the coefficient of performance increases as the operating time increases. The system performance was also analyzed according to the flow rates of the secondary fluids supplied to the main components. As the flow rates of the secondary fluids supplied to the main components increased, the cooling capacity improved, and the coefficient of performance was found to be compounded by the secondary flow conditions and the operating times of the adsorption and desorption operation modes. Based on the results, it was found that the cooling capacity, coefficient of performance, and specific cooling power of the chemisorption heat pump can be operated in a large range from 876.7 to 3070.0 W, 0.13 to 0.32, and 39.3 to 137.7 W/kg, respectively, depending on the operating conditions. [ABSTRACT FROM AUTHOR]

Increasing demand for rare earth elements (REEs) has stimulated research on novel recovery methods from sources like industrial effluents. Our recent study demonstrated that algal biofilms are good candidates for the adsorption of REEs and that the extracellular polymeric substances (EPS) within the biofilm were a key accumulator of REEs. In this work, we measured the desorption kinetics, extents, and selectivity of REEs from the algae Euglena mutabilis in suspensions and biofilms using aqueous solutions of HCl at pH between 1.5 and 4, and Na2EDTA at pH 5. We examined the potential for reusing suspended and biofilm biomass for repeated adsorption–desorption cycles. The desorption kinetics were similar for suspensions and biofilms, with equilibrium being reached within 20 min. The extent of desorption was higher in biofilms with 86% and 95% desorption, compared to suspensions which had 72% and 74% desorption using HCl and Na2EDTA, respectively. We postulate that the difference between suspensions and biofilms is attributed to the binding sites in the EPS matrix of the biofilm being more readily protonated than those at the algal cell wall surface. Heavy REEs were found to preferentially desorb at pH 4 over lighter REEs. After 3 repeated adsorption–desorption cycles, the adsorption capacity of biofilms increased by 280% and 80% using HCl and Na2EDTA, respectively, compared to an 80% decrease in biosorption capacity for the suspension. The increase in biofilm biosorption capacity was attributed to the simultaneous desorption of divalent cations alongside REEs from the EPS increasing the number of available binding sites. [ABSTRACT FROM AUTHOR]

N,N‐Diethylethanolamine (DEEA) is a potential high‐capacity CO2‐capturing solvent. The CO2 reactivity of DEEA can be improved by the addition of rate promoters. Both equilibrium CO2 solubility and desorption rate are also influenced by promoters. In this work, the effect of promotion of DEEA with three amino acid salts, potassium arginate (PA), potassium prolinate (PP), and potassium glycinate (PG), was investigated. In a stirred cell reactor, CO2 reactivity of the promoted solutions was studied at 303 K. Rate promotion with PA was most effective; this was then followed by PP and PG. The value of the liquid‐side mass transfer coefficient (0.005 cm/s) for CO2 absorption in water inside the stirred cell was found. Equilibrium CO2 solubility in the promoted mixtures was measured. Empirical equations that predicted solubility data (accuracy 99%) were proposed. Desorption trials were performed at 363 K. PA, PP, and PG lowered sensible energy constraint by 59%, 32%, and 30%. PA was most‐suited for faster desorption of aqueous solutions of DEEA. Overall, potassium salts of arginine, proline, and glycine were promising candidates for improving the performance of the tertiary amine DEEA. Finally, catalytic desorption of loaded solutions of DEEA was studied and it was found that alumina was a promising catalyst for faster desorption. [ABSTRACT FROM AUTHOR]

P‐type organic cathode materials typically exhibit high redox potentials and fast redox kinetics, presenting broad application prospects in aqueous zinc batteries (AZBs). However, most of the reported p‐type organic cathode materials exhibit limited capacity (<100 mAh g−1), which is attributable to the low mass content ratio of oxidation‐reduction active functional groups in these materials. Herein, we report a high‐capacity p‐type organic material, 5,12‐dihydro‐5,6,11,12‐tetraazatetracene (DHTAT), for aqueous zinc batteries. Both experiments and calculation indicate the charge storage of DHTAT mainly involves the adsorption/desorption of ClO4− on the −NH− group. Benefitting from the high mass content ratio of the −NH− group in DHATA molecule, the DHATA electrode demonstrates a remarkable capacity of 224 mAh g−1 at a current density of 50 mA g−1 with a stable voltage of 1.12 V. Notably, after 5000 cycles at a high current density of 5 A g−1, DHTAT retains 73 % of its initial capacity, showing a promising cycling stability. In addition, DHTAT also has good low‐temperature performance and can stably cycle at −40 °C for 4000 cycles at 1 A g−1, making it a competitive candidates cathode material for low‐temperature batteries. [ABSTRACT FROM AUTHOR]

Understanding the effects of Scandium (Sc) on the hydrogen absorption and desorption capabilities and the underlying mechanisms within Ti–Sc alloys is crucial for their applications as hydrogen storage materials. In this study, we explore the influence of Sc on deuterium (D) behavior in Titanium (Ti) films through a combination of experimental characterization and theoretical simulations. The Sc-doped Ti films with different Sc ratio were prepared using magnetron sputtering. Our findings indicate that Sc doping raises the D absorption temperature from 350 °C to 500 °C, and the Sc-doped Ti deuteride films exhibit higher apparent activation energies and temperatures for D desorption. Results from both experiments and DFT calculations indicate that these phenomena are attributed to the atomic size effect, in which the larger Sc atoms reduce the Ti–H spacing, thereby strengthening the interaction between the adjacent Ti atoms and H atoms. The enhanced interaction presents a greater challenge for H atom diffusion within α-Ti and complicates the dissociation of TiH 2. This study provides a vital theoretical and experimental basis for understanding the effects of Sc doping on the hydrogen absorption and desorption properties in titanium alloys. • Ti–Sc films possess higher hydrogen storage ability at high temperatures. • Sc increases the apparent activation energies for D desorption. • Sc doping strengthens the Ti–H bonds and enhances the hydride stability. • The rate-determining step of D absorption in Ti–Sc films changes with temperature. [ABSTRACT FROM AUTHOR]

The interaction of deuterium (D) with defects produced by high heat flux (HHF) in tungsten relevant to Edge Localized Mode (ELM-like) transient events in ITER was studied using thermal desorption spectroscopy (TDS). Defects in tungsten were created by 10 pulses of D plasma HHF with a duration of 1 ms each. The energy density of the pulses was 0.7 and 1.7 MJ/m2, which is below and above the tungsten melting threshold, respectively. Using TDS up to 1800K, D was completely removed from HHF damaged samples, and then the remaining defects were decorated by D 3 + ion beam irradiation (667 eV/D+) to a fluence of 1022 D/m2 at a temperature of 470 K with sequential in-situ TDS. Deuterium retention after exposure to a power load of 1.7 MJ/m2 is almost two times higher than in the case of 0.7 MJ/m2. Cracks appear on the tungsten surface under a load of 1.7 MJ/m2, and closed cracks similar to elongated voids are found in deeper layers in the tungsten bulk. The formation of the cracked surface increases the effective surface area for D trapping after ion beam irradiation which leads to significant D retention by a factor of 8 compared to a crack-free surface. It is expected that after ELM-like events, D retention in tungsten will be increased during subsequent steady-state plasma operation. [Display omitted] • Cracks and closed cavities are observed in W after exposure to pulsed HHF D plasma above the W melting threshold. • The cracked surface induced by HHF plasma loads increases the D retention in W. • ELM-like events lead to increased D retention in W during subsequent steady-state plasma operation regime. • The impact of ELM-like events on D retention should be taken into account when assessing the total T retention in PFMs. [ABSTRACT FROM AUTHOR]

Hydrogen embrittlement (HE) extant a substantial concern to press-hardened steel (PHS) owing to superior strength. The high strength to light-weight automobile structures necessitates the advancement of superior HE resistance PHS. This study investigated the HE susceptibility of Nb-microalloyed PHS by slow strain rate tensile testing, u-shaped constant bending load test, and thermal desorption spectroscopy. Nb enhances microstructure and HE resistance by introducing retained austenite, refining prior austenite grains (21.14–13.73 μm), forming low-angle grain boundaries, and nano-scale precipitates. Nb-alloyed steel exhibits no-cracking over 300 h under high pre-bending stress and decreases elongation loss up to 48% in hydrogen environment as compared to Nb-free steel. Diffusible H-content in 0.12 wt% Nb-steel reduces to 14.9% of that in Nb-free steel owing to enhanced hydrogen traps, the Fcc/Bcc matrix, and carbide precipitation. The multi-phase microstructure with nano-scale NbC precipitation impeded the localized H-dispersion, enhancing the HE resistance in PHS despite its high strength. [Display omitted] • Grain boundary strengthening achieved by refined microstructure in Nb-steel. • Retained austenite with NbC enhances hydrogen embrittlement resistance. • 0.12 wt% Nb steel mitigate diffusible hydrogen content to 14.9% of that Nb-free steel. • Nb-alloying decreases elongation loss by up to 48% in presence of hydrogen. [ABSTRACT FROM AUTHOR]

Adsorption is a classical physicochemical process, widely used in heterogeneous catalysis, chemical engineering, and environmental science. Regenerating the exhausted adsorbents or reversible desorption is vital to achieving sustainable adsorption techniques, while the common chemical/thermal regeneration is energy‐intensive and environmentally unfriendly. Given that the adsorbents' surface physicochemical properties like surface charge and electronic structures, significantly affect adsorption capacity and kinetics, which offers opportunities for green desorption by tailoring surface chemical/electronic features. Since a certain adsorbate possesses specific adsorption energy on adsorbents, an electro‐desorption idea is therefore proposed to electrically control the (sequential) release of aqueous substances by regulating the interfacial adsorption interaction above the corresponding threshold interfacial potential. Herein, as a proof‐of‐concept design, a sub‐millimeter‐sized carbon nanotube‐reinforced conductive resin composite adsorbent with high conductivity and mechanical strength is developed, which demonstrates a high electro‐desorption efficiency toward benzoic acid (94.1%; 3 V negative bias) and well‐controlled electro‐desorption kinetics by regulating the surface polarization. Using benzoic acid and terephthalic acid as a model of organic mixtures, the adsorbent exhibits an efficient bias‐dependent sequential electro‐desorption capability in separating mixtures. This work provides a promising efficient solution for green and efficient desorption/regeneration and a pioneering electrically‐driven strategy toward aqueous mixture separation. [ABSTRACT FROM AUTHOR]

Hydrogen is a major nonmetallic impurity in the coolant of sodium-cooled fast reactors (SFRs) during normal operation. A higher hydrogen concentration than the gas–liquid equilibrium has been transiently detected in the gas space of actual SFR plants. The presence of several sodium compounds can increase hydrogen generation; however, a thorough understanding of the thermal behavior of candidate reactions is lacking. Herein, thermal analysis reveals the hydrogen release behavior of sodium hydride. Mass spectrometry indicates hydrogen generation with decreasing sample mass, indicating thermal decomposition. Detailed kinetic analysis based on master plot methods indicates that the hydrogen release reaction occurred through a mechanism involving random nucleation and growth of nuclei. Furthermore, the reaction rate was newly formulated based on a kinetic model function representing the above mechanism and the Arrhenius-type reaction rate constant comprising an activation energy of 119.0 ± 0.8 kJ mol−1 and a frequency factor of 1.8 × 107 s−1. These findings will enable the numerical simulation of the hydrogen release behavior in SFRs. [Display omitted] • Thermal analysis revealed the thermal behavior of sodium hydride as a hydrogen release source in sodium-cooled fast reactors. • Detailed kinetic analysis based on master plots showed the reaction rate and mechanism of the thermal decomposition. • A new formula was created for the reaction rate using an Arrhenius-type reaction rate constant and a kinetic model function. • Comparison of theoretical and experimental master plots confirmed a nucleation–growth-type reaction mechanism. [ABSTRACT FROM AUTHOR]

In this study, reduced graphene oxide (rGO) coatings were fabricated on duplex stainless steel (DSS) substrates using the electrophoretic deposition (EPD) method to evaluate their hydrogen resistance performance. The successful fabrication of rGO coatings was confirmed using Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Photoelectron Spectroscopy (XPS). The structural characteristics were characterized using Raman spectroscopy and X-ray Diffraction (XRD). The results indicate that the EPD voltage is a crucial factor affecting the surface quality of and hydrogen resistance performance of rGO. Lower voltages resulted in lower degrees of rGO reduction and higher surface wrinkle density, while higher voltages caused bubble formation, significantly degrading the coating quality and hydrogen resistance performance. The optimal hydrogen resistance was achieved at an EPD voltage of 7.5V and a deposition time of 6 min. Electrochemical hydrogen charging tests and thermal desorption analysis (TDA) demonstrated that rGO coatings prepared under optimal conditions exhibited excellent hydrogen resistance efficiency, significantly reducing hydrogen atom penetration in hydrogen environments. The study further revealed that bubble formation significantly reduces the hydrogen resistance of rGO, which is attributed to increased interlayer spacing and the loss of the "labyrinth effect". • Electrophoretic deposition (EPD) method can effectively reduce graphene oxide. • Optimal EPD parameters were identified for rGO coatings to enhance hydrogen resistance. • RGO coatings reduced hydrogen penetration by preserving a dense multilayer structure. [ABSTRACT FROM AUTHOR]

Pre-strain is a key factor affecting the critical conditions for hydrogen-induced delayed cracking (HIDC). In this study, the threshold stress and critical hydrogen concentration for HIDC of MS1300 and MS1500 steels with different pre-strains were measured by constant load tensile (CLT) tests. The results demonstrated that although MS1500 has higher strength, its safe service strength is lower than that of MS1300 when the hydrogen content exceeds 0.5 wppm. Additionally, the hydrogen penetration, thermal desorption spectroscopy, and hydrogen microprinting methods were also used to analyze the hydrogen-induced failure mechanism. These studies provide an effective data reference for improving the industrial production process. [Display omitted] • The critical conditions for HIDC of MS1300 and MS1500 were established by CLT tests. • Hydrogen was enriched at the grain boundaries in MS1300 before and after deformation. • The HIDC sensitivity of martensitic steels increased with increasing pre-strain. • The safe service area of MS1300 is higher than MS1500 when the C 0 > 0.5 wppm. [ABSTRACT FROM AUTHOR]

ABSTRACT Mass spectrometry imaging (MSI) technologies are widely used today to study the in situ spatial distributions for a variety of analytes. As these technologies advance, the pursuit of higher resolution in MSI has intensified. The limitation of direct desorption/ionization is its insufficient ionization, posing a constraint on the advancement of high‐resolution MSI technologies. The introduction of postionization process compensates the low ionization efficiency caused by sacrificing the desorption area while pursuing high spatial resolution, resolving the conflict between high spatial resolution and high sensitivity in direct desorption/ionization method. Here, we discuss the sampling and ionization steps of MSI separately, and review the postionization methods in MSI according to three different sampling modes: laser sampling, probe sampling, and ion beam sampling. Postionization technology excels in enhancing ionization efficiency, boosting sensitivity, mitigating discrimination effect, simplifying sample preparation, and expanding the scope of applicability. These advantages position postionization technology as a promising tool for biomedical sciences, materials sciences, forensic analysis and other fields. [ABSTRACT FROM AUTHOR]

Oxygen (O2) electroreduction offers a green approach for singlet oxygen (1O2) synthesis in wastewater contaminants detoxification. However, traditional single O2 activation on single‐metal catalytic sites seriously suffers from the kinetically‐unfavorable desorption of adsorbed superoxide species (•O2−*/•OOH*). Here, we demonstrate a novel dual O2 coactivation pathway on shortened Fe1−OV−Ti sites for superior 1O2 electrosynthesis through a rapid disproportionate process between surface‐confined •O2−*/•OOH*. Theoretical calculations combined with in situ electrochemical spectroscopies demonstrated that the shortened distance between Fe single atom and adjacent unsaturated Ti atom facilitates the direct recombination of surface‐confined Fe−•OOH and Ti−•OO− to yield 1O2, bypassing the formidable •O2−*/•OOH* desorption process. Impressively, Fe1−OV−Ti could realize an excellent 1O2 electrosynthesis rate of 54.5 μmol L−1 min−1 with an outstanding 1O2 selectivity of 97.6 % under neutral condition, surpassing that of Fe1−O−Ti (27.1 μmol L−1 min−1, 91.7 %). Using tetracycline (TC) as a model pollutant, the resulting Fe1−OV−Ti electrode achieved nearly 100 % degradation in 120 min at −0.6 V, meanwhile preventing the generation of toxic intermediates. This study provides a new 1O2 electrosynthesis strategy by controlling the distance of adjacent catalytic sites for the coactivation of dual molecular oxygen. [ABSTRACT FROM AUTHOR]

In this study, hollow nanoflower spherical Cu9S8 and Cu9S8/Fe3O4@BC with adsorption and antibacterial properties was prepared by coprecipitation and solvothermal method, respectively. The adsorption results showed that the Cu9S8 exhibited excellent adsorption performance on sulfonamide antibiotics (SAs), especially for sulfamethoxazole (SMZ). The optimal addition amount of Cu9S8 is 0.2 g, which results in a maximum adsorption capacity of 33.4 mg/g for SMZ within 120 min. The fitting results of adsorption and desorption kinetics and thermodynamics, as well as the conditions such as pH value and ionic strength were compared. It was found that different interactions led to the differential adsorption of SAs by Cu9S8. The desorption experiment further elucidated its adsorption mechanism. The large desorption capacity indicates that SAs on Cu9S8 can be further recovered and treated. The auto-deposition characteristics of Cu9S8 and the hysteresis loop of Cu9S8/Fe3O4@BC were studied to effectively recover Cu9S8 from aquatic environments. Additionally, more than 99% of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were exterminated by Cu9S8 and Cu9S8/Fe3O4@BC within 20 min. The above results suggested that the hollow nanoflower spherical Cu9S8 and Cu9S8/Fe3O4@BC composite materials can provide a new strategy for solving pollution problems and waste treatment. [ABSTRACT FROM AUTHOR]

The electrophysical properties of nanostructured MgAl2O4 ceramics sintered at 1300 °C for 5 h, as well as thick films were obtained and investigated. The study of adsorption-desorption cycles was carried out after sintering and aging test. It is shown that ceramic has a sensitivity to humidity in the range of 25–95% with minimal hysteresis of the characteristic in adsorption-desorption cycles, which can be eliminated after the aging test. Thick films based on it are characterized by hysteresis and loss of sensitivity at low values of relative humidity, which is caused by the clogging of small nanopores. [ABSTRACT FROM AUTHOR]

Water contamination is one of the biggest environmental issues the world is currently experiencing, and it is a result of growing industry and urbanization. The main causes of contaminated water are the textile industry and the colours included in waste effluent. The production of polymeric ferrite composites is the focus of this investigation. To the best of our knowledge these combinations of polymer and ferrites have not been synthesized before. The purpose of using these polymeric ferrite composites was to eliminate the artificially reactive Orange-122 dye from aqueous solutions. Various factors were optimized to get the best clearance, including pH (2–12), composite dose (0.01–0.3 g), contact time (10–120 min), temperature, and beginning dye concentration (20–200 mg/L). The acidic range (2–5) was shown to have the maximum dye removal of reactive dye, and the ideal composite dose was found to be 0.03 g/50 mL. Within the first sixty to ninety minutes, balance was reached. At 120–150 mg L–1, the maximum level of reactive dye clearance was attained. As the temperature was raised, the chosen dye was more effectively removed, indicating that the process was endothermic. Various models, including thermodynamic, kinetic, and equilibrium models, were used to verify. [ABSTRACT FROM AUTHOR]

This publication presents a comprehensive method for assessing the homogeneity of the composition of a large batch of polymer materials, with a mass of 1.5 tons, consisting of 60 transport packages, using the example of rubber granulate from recycled car tires. The presented method combines statistical analysis tools used to determine the samples number to be taken from the batch and the pyrolytic thermal desorption technique coupled with gas chromatography-mass spectrometry (Py/TD-GC-MS), used for material identification. Directions for improving the method for the quantitative identification of batch components are also indicated. The developed method can be applied to assess the purity of batches of recycled rubber granulate used in the construction of sports field surfaces and to determine the content of substances harmful to the environment and human health, such as polycyclic aromatic hydrocarbons. The direction for improving the developed spot-check control method using an alternative approach is to supplement it with a quantitative assessment of batch parameters in relation to the threshold values, such as tolerance limits. [ABSTRACT FROM AUTHOR]

Inter alia due to the high demand for lithium‐ion batteries, the required critical heavy metals have become a scarce resource. Consequently, effective recycling processes that enable the recovery of such materials are of high interest. A silica adsorbent functionalized with amino‐polycarboxylate derivate ligands (HSU331) was applied in order to selectively adsorb nickel(II) and cobalt(II). Subsequently, suitable parameters for a pH‐swing desorption were investigated. Maximum desorption efficiencies for Co(II) were achieved at pH = 2.7 (72 %) and for Ni(II) at pH = −0.5 (94 %). These results were used for the design of a pH‐shift desorption process in order to selectively recover Co(II) and regenerate the adsorbent after simultaneous adsorption of Co(II) and Ni(II). [ABSTRACT FROM AUTHOR]

Phosphorus (P) is typically fixed in red soils (as Fe-P and Al-P). P release from different sources i.e. Rock-phosphate (RP), Farm Yard Manure (FYM), and Vermicompost (VC) is mainly governed either by adsorption, desorption, fixation, or ligand exchange. The present study was undertaken using phosphorus solubilizers Burkholdaria cariabensis (PSB1) and B. cepacia (PSB2), inorganic sources Udaipur Rock-phosphate (RP1) and Purulia Rock-phosphate (PR2) and organic sources (FYM and VC) applied in red and alluvial soils. Results showed that pH statistically on par and available P content were significantly varied in both soil type under laboratory incubation experiment at 15, 30, 45, and 60 days intervals. P adsorption and desorption experiments were also carried out taking heavy suspension of two P-solubilizers. Results showed that higher soluble P was recorded in FYM amended soils (T8, T9, T10 and T11) over the VC treated soils (T12, T13, T14 and T15) in both soils. Data showed that the RP1 have higher (34.00%) total P concentration as compared to RP2 (10.87%). Meanwhile, it was observed that higher P adsorption observed in red soils as compared to alluvial soils and vice-versa in case of desorption maxima, similarly higher P adsorption in PSB1 as compared to PSB2. A quantitative and qualitative study on organic acid secretions by Burkholdaria cariabensis and Burkholdaria cepacia needs to be carried out in the future. [ABSTRACT FROM AUTHOR]

Comparison of the structural features and catalytic performance of bimetallic nanocatalysts will help to develop a unified understanding of structure–reaction relationships. The single-molecule fluorescence technique was utilized to reveal the differences in catalytic kinetics among PtRu bimetallic nanocatalysts and Pt and Ru monometallic nanocatalysts at the single particle level. The results show that bimetallic nanocatalysts have higher apparent rate constants and desorption rate constants relative to monometallic nanocatalysts, which leads to their higher catalytic activity. At the single particle level, bimetallic nanocatalysts have a wider distribution of apparent rate constants, suggesting that bimetallic nanocatalysts have higher activity heterogeneity relative to monometallic nanocatalysts. By investigating the relationship between the reaction rate and the rate of dynamic activity fluctuations, it was found that spontaneous surface restructuring and reaction-induced surface restructuring of nanoparticles occurred. The surface of bimetallic nanoparticles restructured faster, which made the bimetallic nanocatalysts more active. These findings provide new insights into the design of highly active bimetallic nanocatalysts. [ABSTRACT FROM AUTHOR]

We report a solution-based approach for the synthesis of oxidation-free MoS2 films, focusing on interface analysis. Through a sulfurization-free solution process and single-step annealing, the oxidation-free MoS2 film is successfully prepared on Si3N4 surfaces, showing improved uniformity with a surface roughness below 0.5 nm and a thickness of 4 nm at a precursor solution concentration of 30 mM, annealed between 700 and 800ºC. The MoS2 films exhibit a hexagonal lattice structure with crystallographic orientations of (1 1 0 0) and (1 2 1 0) with lattice spacings of 0.27 nm and 0.16 nm respectively. Interfacial analysis by X-ray photoelectron spectroscopy (XPS) on SiO2 reveals migration of oxygen species as evidenced by a shift in the Si 2p spectrum at binding energies between 102.6 eV and 102.8 eV. MoS2 films on Si3N4 show a complex Si 2p peak evolution at binding energies between 100.9 and 101.8 eV, providing valuable insights into the synthesis of oxide-free MoS2 films for potential applications in advanced electronic devices. [ABSTRACT FROM AUTHOR]

Ti-doped [1,1,1,1] paracyclophane(PCP) and its derivatives have been designed by substituting heteroatoms boron and nitrogen and studied their hydrogen storage properties using density functional theory. Heteroatom substitution is important for stronger Ti-binding whereas Ti-doping for light weight, almost empty d- orbital and its stronger interaction with H 2 molecules. Six configurations are obtained: PB1,PB2(boron substitution), PN1,PN2 (nitrogen substitution) and PBN1,PBN2(boron and nitrogen co-substitution). Stability of all Ti-doped structures has been confirmed using cohesive and formation energy. PCP, PB1, PB2, PN1, PN2, PNB1 and PNB2 show gravimetric hydrogen uptake capacity(adsorption energy) as 5.52(0.67),6.90(0.5),6.90(0.53),5.37(0.6),5.37(0.61), 5.48(0.7) and 5.48(0.74 eV) wt% respectively. Ti-doped boron substituted structures show required H 2 uptake capacity, suitable adsorption energy, thermodynamically favorable H 2 adsorption at ambient conditions, moderate desorption temperature, structural and thermodynamic stability, thus more suitable for hydrogen storage than nitrogen substituted and boron and nitrogen co-substituted structures. Ti-doped boron substituted PCP is a promising reversible hydrogen storage candidate. [Display omitted] • Ti-doped B/N or B and N substituted paracyclophane(PCP) is considered for H 2 uptake. • B-substituted Ti-PCP is more suitable for H 2 storage compared to other structures. • Ti atom strongly bind with B-substituted Ti-PCP compared to other structures. • One extra H 2 gets adsorbed on each Ti on B-substituted Ti-PCP than Ti-PCP [ABSTRACT FROM AUTHOR]

The current studies primarily analyze the heterogeneity and complexity of mesopore structures based on low-temperature nitrogen (N2) adsorption curves and the Frenkel–Halsey–Hill (FHH) fractal model. However, these studies ignore the fact that the low-temperature N2 desorption curve can also reflect the desorption performance of the mesopore structure. In this research, novel fractal indicators for characterizing the adsorption–desorption performance of mesopores based on the fractal dimension from the N2 adsorption curves and N2 desorption curves are proposed. The novel fractal indicators I1 and I2 are applied to evaluate the adsorption–desorption performance of mesopores with pore size 2–5 nm and pore size 5–50 nm, respectively. The fractal indicator I1 shows an increasing trend with coalification, reflecting that the gas adsorption performance of 2–5 nm mesopores is enhanced with coalification. The fractal indicator I2 exhibits a trend of first increasing and then decreasing with coalification, indicating the gas desorption performance of mesopores with pore size 5–50 nm decreases first and then increases. The proposed indicators provide novel analytical parameters for further understanding the gas adsorption–desorption mechanism of porous coal-based or carbon-based materials. [ABSTRACT FROM AUTHOR]

Highlights: AlOOH/FeOOH composite catalysts (AF-M/N) were synthesized with various ratios, and the optimized catalyst was (AF-1/9), with a relative heat duty of 78.7% and a relative desorption factor of 194.7% compared to non-catalytic benchmarks. The structure–activity correlation was investigated, with the main factors being the MSA and B/L ratio, which is consistent with AlOOH-based catalysts. This discovery was applicable for other Al-based catalyst design. The key step of the catalytic carbamate breakdown mechanism, isomerization, was re-investigated quantitatively with molecular simulation. The water-assisted intermolecular proton transfer was preferred based on the PES diagram. AlOOH acted as a Lewis acid to stabilize carbamic acid and Zwitterion and reduce activation energy. This discovery helped the synthesis and design on new types of solid acid catalysts. In order to reduce the massive heat duty of amine-based CO2 capture technology, an AlOOH/FeOOH composite catalyst (AF-M/N) was synthesized to speed up the CO2 desorption rates and reduce the heat duty of an aqueous MEA solution. The catalysis of AF-M/M from 1/9 to 9/1 was investigated comprehensively, with characterization of the catalytic desorption with heat duty and desorption factors. Results indicated the special composite catalyst (AF-1/9) possessed optimized catalysis with a relative heat duty of 78.7% and a desorption factor of 0.0037 × 10−3 (mol CO2/L2 kJ min) and relative desorption factor of 194.7%. The structure–activity correlations indicated that the mesopore surface area (MSA), which reached 329 m2/g, and Brϕnsted/Lewis acid ratio (B/L ratio) of 0.11 were the most important factors for enhancing catalysis. Furthermore, molecular simulations were conducted for the catalytic carbamate breakdown mechanism, focusing on the "isomerization" of "carbamate acid" vs. "Zwitterion" as the key step. From the DFT study, the isomerization was most likely to proceed with H2O as catalyst via intermolecular proton transfer instead of intramolecular proton transfer, with an activation energy Ea of 85.9 kJ/mol. With the aid of AlOOH the isomerization was further facilitated due to stabilized Zwitterion, and the Ea decreased to 69.2 kJ/mol. The results not only synthesized a new heterogeneous catalyst but also revealed the map of "isomerization" on a molecular level. Such a discovery indicates that water-assisted proton transfer is advantageous for catalytic carbamate breakdown. [ABSTRACT FROM AUTHOR]

To study the physicochemical (including adsorption) properties of nanodiamond, it is necessary to reproducibly obtain a carbon surface of an individual particle without metallic impurities of an unknown composition. Such a surface can be obtained through an additional procedure of the deep purification of a commercially available sample. This work is devoted to a study of the composition of non-combustible impurities of detonation diamond nanopowder. Using inductively coupled plasma mass spectrometry, iron and titanium are identified as the main metallic components of the non-combustible residue, the presence of Cr, Ni, Zr, As, and Sb is qualitatively established. The expected composition of the main molecular ions formed on the surface of the non-combustible residue under laser desorption/ionization mass spectrometry conditions is presented. Based on the results of the mass spectrometric analysis, a version of two-stage chemical treatment of detonation diamond nanopowder is proposed, which made it possible to reduce the mass fraction of non-combustible impurities during annealing in air from 2.0 to 0.1%. [ABSTRACT FROM AUTHOR]

This article presents the unique research results of the comprehensive analysis of the porous structure of activated carbons obtained from biomass waste materials from the wood industry during activation in an air atmosphere. The porous structure was analysed on the basis of nitrogen and argon adsorption isotherms via complementary multi-method analysis, i.e. the new numerical clustering-based adsorption analysis, the non-local density functional theory and the quenched solid density functional theory methods. The analytical results for the prepared activated carbons were compared with analogous results obtained for commercial activated carbon. On the basis of the conducted studies it has been determined that the new numerical clustering-based adsorption analysis method gives credible and valuable information on the textural properties of activated carbons which are in strict correlation and mutually complement with the results of the analysis with the use of the quenched solid density functional theory method. The research results obtained in this paper, it has also been shown that from waste materials of the wood industry, in a relatively cheap and cleaner production process, it is possible not only to obtain carbonaceous materials almost comparable to commercial activated carbon, but also to manage the waste in accordance with the principles of a closed-loop economy and sustainable development. The paper pays also attention to the often overlooked economic and ecological aspects, which should nevertheless be taken into account when comparing different adsorbents, rather than their textural properties alone. [ABSTRACT FROM AUTHOR]

In this study, metal-doped quaternary nano ferrites (Co0.5Zn0.25M0.25Fe2O4, M = Ba, Cu, Mn, Ni and Sr) were synthesized and evaluated for their efficiency in removing Direct Orange-108 Acid Dye from aqueous solutions. The adsorption performance of these materials was systematically investigated under various conditions. Optimal pH levels for dye removal were found to be pH 2 (41.45 mg/g), pH 2 (36.37 mg/g mg/g), pH 4 (31.13 mg/g), pH 4 (44.75 mg/g), and pH and 3 (39.62 mg/g) at optimal dosage of 0.05 g/50 mL and at an initial concentration of at 75 ppm and 50 ppm for Co0.5Zn0.25Ba0.25Fe2O4, Co0.5Zn0.25Cu0.25Fe2O4, Co0.5Zn0.25Mn0.25Fe2O4, Co0.5Zn0.25Ni0.25Fe2O4 and Co0.5Zn0.25Sr0.25Fe2O4 respectively. Additionally, the study revealed that an optimum temperature of 40 °C enhanced the adsorption efficiency, resulting in adsorption capacities of 41.92 mg/g, 40.56 mg/g, 33.22 mg/g, 48.00 mg/g, and 43.71 mg/g for Co0.5Zn0.25Ba0.25Fe2O4, Co0.5Zn0.25Cu0.25Fe2O4, Co0.5Zn0.25Mn0.25Fe2O4, Co0.5Zn0.25Ni0.25Fe2O4 and Co0.5Zn0.25Sr0.25Fe2O4 respectively. The shaking time with optimal results were obtained at 45 and 60 min. Similarly, as a photocatalyst have optimal pH at 2, 3 and 4, optimum dose 0.05 g/50 mL, initial concentration of dye was 50 and 75 ppm with contact time of 45 and 60 minutes at 40 °C as optimum temperature. The pseudo second order adsorption kinetic model and Langmuir adsorption equilibrium isotherm displayed strong fitting for experimental data. While degradation kinetic follow BMG and second kinetic model. NH4OH solution showed maximum desorption The thermodynamic study demonstrated the exothermic character. The adsorption study of real textile effluents was also conducted that yielded valuable information. Highlights: Novel metal doped quaternary nano ferrites Co0.5Zn0.25M0.25Fe2O4 (M = Ba, Cu, Mn, Ni and Sr) were synthesized, characterized, and used for dye adsorption. Langmuir adsorption isotherm and pseudo second order kinetic model fitted best and proved most appropriate for this study. The size, changeable properties and shape are the most notable characteristics of nano ferrites, therefore the use of ferrites in many applications is enhancing day by day. [ABSTRACT FROM AUTHOR]

The study aims to comprehend the behavior of nitrogen in the argon oxygen decarburization (AOD) process during the production of nitrogen‐alloyed stainless steels, where the precise adjustment of nitrogen content plays a crucial role in enhancing productivity. Furthermore, the objective is to investigate the rate of change in nitrogen content when blowing a mixture of nitrogen and argon, instead of using pure nitrogen or argon alone. Hence, both nitrogenation and denitrogenation cases are examined, and kinetic models are developed. While solution thermodynamics can predict the final nitrogen content, the kinetics are influenced by the gas flow rate, steel temperature and composition, and levels of the surface active elements in the steel. By integrating a previously developed thermodynamic equilibrium equation with the kinetic models, nitrogen contents in the range of 0.150–0.400% can be reliably predicted. Consequently, the equations can be applied to predict nitrogen content during both the nitrogenation and denitrogenation stages in the reduction and desulfurization phases of the AOD process. [ABSTRACT FROM AUTHOR]

Objectives: Exhaled breath analysis is an attractive lung cancer diagnostic tool. However, various factors that are not related to the disease status, comorbidities, and other diseases must be considered to obtain a reliable diagnostic model. Methods: Exhaled breath samples from 646 individuals including 273 patients with lung cancer (LC), 90 patients with cancer of other localizations (OC), 150 patients with noncancer lung diseases (NLD), and 133 healthy controls (HC) were analyzed using gas chromatography–mass spectrometry (GC–MS). The samples were collected in Tedlar bags. Volatile organic compounds (VOCs) were preconcentrated on Tenax TA sorbent tubes with subsequent two-stage thermal desorption followed by GC–MS analysis. The influence of age, gender, smoking status, time since last food consumption, and comorbidities on exhaled breath were evaluated. Also, the effect of histology, TNM, tumor localization, treatment status, and the presence of a tumor on VOC profile of patients with lung cancer were assessed. Intergroup statistics were estimated, diagnostic models were created using artificial neural networks (ANNs) and gradient boosted decision trees (GBDTs). Results: Smoking status and food consumption affect exhaled breath VOC profile: benzene, ethylbenzene, toluene, 1,3-pentadiene 1,4-pentadiene acetonitrile, and some ratios are significantly different in exhaled breath of smokers and nonsmokers; the ratios 2,3-butandione/2-pentanone, 2,3-butandione/dimethylsulfide, and 2-butanone/2-pentanone are affected by time since last food consumption. Exhaled breath of LC is affected by the form of the disease and comorbidities. One-pentanol and 2-butanone were different in exhaled breath of patients with various tumor localization; 2-butanone was different in exhaled breath of patients before and during treatment. Diabetes as a comorbidity affects the pentanal level in exhaled breath; obesity affects the ratios of 2,3-butanedione/dimethylsulfide and 2-butanone/isoprene. Sensitivity and specificity of diagnostic models aimed to discriminate LC and HC, OC, and NLD were 78.7% and 51.0%, 62.2% and 53.4%, and 60.4% and 58.0%, respectively. HC and patients, regardless of the disease, can be classified with sensitivity of 76.6% and specificity of 68.2%. Conclusions: The models created to diagnose lung cancer can also classify OC and NLD as patients with lung cancer. Additionally, the influence of comorbidities and factors not related to the disease status must be considered before the creation of diagnostic models to avoid false results. [ABSTRACT FROM AUTHOR]

Constraining the processes that fractionate barium isotopes is essential for utilising barium isotope ratios as environmental tracers. Barium concentration measurements from soils, rivers, and estuaries demonstrate that adsorption–desorption reactions significantly influence the distribution of fluid–mobile barium at the Earth's surface, potentially driving isotopic fractionation. To quantify the direction and magnitude of isotopic fractionation resulting from these reactions, a riverine and an estuarine series of batch experiments were conducted using environmentally important adsorbent minerals and surface waters. Himalayan river sediment and water samples were used to validate the experimental results. Adsorption–desorption reactions were found to be rapid, relative to the average transit time of sediment and water in catchments, and largely reversible. The direction and magnitude of isotopic fractionation in the riverine experiment series were consistent with the riverine field samples (preferential adsorption of the lighter isotopes). The reaction rate, reversibility, and magnitude of isotopic fractionation were found to depend primarily on the mineral. Experiments performed with iron oxyhydroxides (goethite and ferrihydrite) resulted in a greater degree of fractionation compared to clay minerals (kaolinite and montmorillonite). Estuarine experiments, designed to simulate sediment passage through a salinity gradient, demonstrated a high degree of reversibility, with 77% to 94% of adsorbed barium desorbed upon the addition of seawater to freshwater-equilibrated clay minerals. The results of the estuarine experiments suggest that barium isotope ratios measured in marine paleo-archives (e.g. , corals) will reflect both the adsorbed and dissolved freshwater barium inputs to the ocean. The combined findings of this study indicate that the chemical and isotopic behaviour of barium differs from more conventional group 1 and 2 metal isotope systems due to a significant proportion of barium released from bedrock dissolution partitioning to mineral surfaces, rapid reaction rates between fluid–mobile phases, and a high degree of reaction reversibility. Consequently, riverine barium isotope ratios are likely to provide unique insights into the complex array of terrestrial weathering and erosion processes that sustain life on Earth. [ABSTRACT FROM AUTHOR]