Search

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]

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]

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]

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]

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]

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]

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]

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]

Microplastic particles (MPs) have been detected in a variety of environmental samples, including soil, water, food, and air. Cellular studies and animal exposures reported that exposure to MPs composed of different polymers might result in adverse effects at the portal of entry (local) or throughout the body (systemic). The most relevant routes of particle uptake into the body are oral and respiratory exposure. This review describes the various processes that may contribute to the adverse effects of MPs. Only MPs up to 5 µm were found to cross epithelial barriers to a significant extent. However, MPs may also exert a detrimental impact on human health by acting at the epithelial barrier and within the lumen of the orogastrointestinal and respiratory tract. The potential for adverse effects on human health resulting from the leaching, sorption, and desorption of chemicals, as well as the impact of MPs on nutritional status and dysbiosis, are reviewed. In vitro models are suggested as a means of (1) assessing permeation, (2) determining adverse effects on cells of the epithelial barrier, (3) examining influence of digestive fluids on leaching, desorption, and particle properties, and (4) role of microbiota-epithelial cell interactions. The contribution of these mechanisms to human health depends upon exposure levels, which unfortunately have been estimated very differently. [ABSTRACT FROM AUTHOR]

Polyethylene (PE) and other polymers are widely and successfully used as passive samplers for organic pollutants in the environment. This study provides high-resolution experimental data from batch shaking tests on the uptake, reversibility, and linear equilibrium partitioning of polycyclic aromatic hydrocarbons (PAHs) using two different PE sheets of 30 µm and 80 µm thickness. Kinetics for phenanthrene are well described by a mechanistic first-order model with mass transfer limited by an aqueous boundary layer (with a mean thickness of 170 µm). Equilibration in laboratory batch systems during uptake and desorption is very rapid with characteristic times of 1–2 h but this depends on the boundary condition, e.g., the ratio of PE mass to water volume. Therefore, equilibration of PE in other setups, e.g., in soil slurries or sediment suspensions, may take orders of magnitude longer because the boundary condition for PE changes from finite to infinite bath conditions (soil or sediment particles may keep the concentration in water almost constant). Solid precipitates for high molecular weight PAHs explain partition coefficients below expected values because of kinetic limitations in such a system. Nevertheless, passive sampling can be employed safely if such limitations are considered; furthermore, partition coefficients can be estimated accurately by empirical relationships (e.g., within 0.1 log unit) based on molecular weight, octanol/water partition coefficients, or subcooled liquid solubilities. [ABSTRACT FROM AUTHOR]

The coal-rock reservoir exhibits a dual porous medium characteristic, where fractures are the primary contributor to permeability, while pore structure influences the gas adsorption properties of coal rock. Gas adsorption induces swelling in the coal matrix, leading to a reduction in fracture width and subsequently causing decreased permeability and reduced well production. Investigating the impact of geological characteristics of coal-rock on gas adsorption and desorption properties can enhance our understanding of the patterns governing changes in coal-layer production. This study focused on the 3# coal seam in China's Qinshui Basin as its research subject. It involved an analysis of mineral composition, physical properties, gas content, and pore structure characteristics to explore the adsorption traits of different gases and conduct experimental studies on variations in gas adsorption and desorption capabilities under diverse conditions. The research findings suggest that the coal rock in the study area is primarily characterized by micropores and small pores, with well-developed larger pores and fractures. The pore connectivity is somewhat limited, and the predominant pore size ranges from 100 to 200 nm. The average permeability measures 0.198 × 10–3 µm2, while the mean specific gas content stands at 21.7 m3/t. Analysis of the isothermal adsorption curve reveals a substantial increase in adsorption when pressure falls below 3.5 MPa due to a steep slope; as pressure continues to rise, there is a gradual upward trend in adsorption until reaching 8 MPa, after which point adsorption increases slowly and stabilizes. Results from binary gas adsorption–desorption experiments indicate low desorption levels and rates for CO2 components compared to relatively higher desorption amounts and rates for CH4 components. Furthermore, it was observed that CO2 has a displacement effect on CH4; higher CO2 concentrations are more conducive to CH4 release and CO2 storage. [ABSTRACT FROM AUTHOR]

In order to reduce environmental pollution caused by biohydrogen production tailing liquid (BHPTL) discharge and realize waste reuse of BHPTL, zeolite was selected as adsorbent to recycle nutrients contained in BHPTL, and the adsorption and desorption characteristics of zeolite acting on BHPTL were investigated. The results showed that the amount of zeolite added had a strong effect on the adsorption effect of NH4+ and K+, and the reaction temperature and solution pH had a weak effect on the adsorption effect of NH4+. The adsorption (desorption) time had a significant effect on the adsorption (desorption) process of K+, but had less effect on the adsorption and desorption process of NH4+. The maximum adsorption rates of NH4+ and K+ in zeolite were 79.05% and 66.33%, corresponding to desorption quantities of 0.616 mg/g and 4.00 mg/g. In addition, the equilibrium desorption rates of NH4+ and K+ in zeolite were 58.49% and 35.84%, corresponding to desorption quantities of 0.38 mg/g and 1.56 mg/g. The adsorption process of zeolites conforms to the quasi-secondary kinetic model and is dominated by chemisorption processes. This study provides a theoretical basis for the recovery of nutrients from BHPTL to produce useful substances, such as fertilizers and soil conditions. [ABSTRACT FROM AUTHOR]

Ambient-condition acetylene hydrogenation to ethylene (AC-AHE) is a promising process for ethylene production with minimal additional energy input, yet remains a great challenge due to the difficulty in the coactivation of acetylene and H2 at room temperature. Herein, we report a highly efficient AC-AHE process over robust sulfur-confined atomic Pd species on tungsten sulfide surface. The catalyst exhibits over 99% acetylene conversion with a high ethylene selectivity of 70% at 25 oC, and a record space-time yield of ethylene of 1123 molC2H4 molPd−1 h−1 under ambient conditions, which is nearly four times that of the typical Pd1Ag3/Al2O3 catalyst, and exhibiting superior stability of over 500 h. We demonstrate that the confinement of Pd-S coordination induces positively-charged atomic Pdδ+, which not only facilitates C2H2 hydrogenation but also promotes C2H4 desorption, thereby enabling a high conversion of C2H2 to C2H4 at room temperature while suppressing over-hydrogenation to C2H6. Ambient-condition acetylene hydrogenation to ethylene (AC-AHE) is a promising process for ethylene production yet remains a challenge. Here the authors report a highly efficient AC-AHE process over robust sulfur-confined atomic Pd species on tungsten sulfide surface, achieving over 99% conversion and 70% selectivity, with a record-breaking ethylene yield and excellent stability exceeding 500 h at 25 °C. [ABSTRACT FROM AUTHOR]

Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and floatable. In the hydrometallurgy of concentrate, collectors adsorbed on concentrate can damage ion-exchange resin and increase the chemical oxygen demand (COD) value of wastewater. In this work, we proposed a new scheme, i.e., desorbing the collectors from concentrate in ore dressing plant and reusing them in flotation flowsheet. Lead nitrate and benzohydroxamic acid (Pb-BHA) complex is a common collector in scheelite flotation. In this study, different physical (stirring or ultrasonic waves) and chemical (strong acid or alkali environment) methods for facilitating the desorption of Pb-BHA collector from scheelite concentrate were explored. Single-mineral desorption tests showed that under the condition of pulp pH 13 and ultrasonic treatment for 15 min, the highest desorption rates of Pb and BHA from the scheelite concentrate were 90.48% and 63.75%, respectively. Run-of-mine ore flotation tests revealed that the reuse of desorbed Pb and BHA reduced the collector dosage by 30% for BHA and 25% for Pb. The strong alkali environment broke the chemical bonds between Pb and BHA. The cavitation effect of ultrasonic waves effectively reduced the interaction intensity between Pb-BHA collector and scheelite surfaces. This method combining ultrasonic waves and strong alkali environment can effectively desorb the collectors from concentrate and provide "clean" scheelite concentrate for metallurgic plants; the reuse of desorbed collector in flotation flowsheet can reduce reagent cost for ore dressing plants. [ABSTRACT FROM AUTHOR]

The environmental implications of tire wear particles (TWPs) have been extensively studied. One notable concern associated with nano-sized TWPs is their potential role as carriers that enhance the spread of co-occurring pollutants, especially in the context of aging processes. This study demonstrated how exposure to acid, ultraviolet (UV) radiation, or ozone (O3) induced alterations in the physico-chemical properties of TWPs, consequently increasing their mobility within saturated sand environments. In cotransport cases, both original TWPs and aged TWPs inhibited the transport of Cd2+ and Ni2+ in different degrees, whereas no obvious changes in their intrinsic mobilities. The contaminant-mobilizing ability of TWPs followed the order of original TWPs/UV-TWPs < H+-TWPs < O3-TWPs. Experimental results and model-based analyses indicated the important role of mobility, adsorption affinity and desorption hysteresis in the cotransport of TWPs and heavy metals. In comparison with original TWPs, the adsorption affinity of H+-TWPs and O3-TWPs for Cd2+/Ni2+ decreased, while that of UV-TWPs was similar to original TWPs. Simultaneously, the desorption rates of TWPs decreased to different extents after aging. The results of this study provide valuable insights on the fate of aged TWPs and their interactions with heavy metals in the natural environment, and help assess the environmental behavior and contaminant mobilization capacity of TWPs, especially considering the distinct effects of different aging processes. It is imperative to emphasise the necessity for targeted management strategies to transport the environmental impacts of TWPs, particularly as they age and interact with heavy metals. [ABSTRACT FROM AUTHOR]

Neonicotinoids are widely used insecticides that accumulate in various environmental matrixes and potentially harm non-target organisms. However, the mechanism of sorption/desorption of neonicotinoids in different loess soils remains poorly understood. Therefore, this study investigated the sorption/desorption of nitenpyram (NIT), a commonly used neonicotinoid, in three different types of loess soils and examined factors influencing the adsorption process using batch experiments. The findings revealed that NIT reached adsorption equilibrium in 4 h in all three loess soil samples. The R2 value (> 0.898) obtained from fitting the sorption/desorption kinetics indicated a good match with the pseudo-second-order model, suggesting the involvement of multiple mechanisms, including chemisorption. The linear and Freundlich models also adequately described the sorption of NIT in loess soils. Additionally, a clear hysteresis phenomenon was observed. The adsorption capacity of NIT is significantly related to the adsorption temperature, solution pH and ionic strength. Upon increasing the initial concentration, the equilibrium adsorption capacity of NIT for gray-cinnamon soil, sierozem, and cultivated loessial soil increased from 3.56, 2.51, and 2.64 mg/kg to 8.49, 3.92, and 5.22 mg/kg, respectively. FTIR spectral analysis revealed that the adsorption of NIT in loess soil was primarily governed by mixed mechanism. This study elucidates the behavior and fate of NIT in soil–water systems in the Northwest, while also establishing a foundation for assessing its ecological risks. The findings have significant practical implications for the future development of environmental management and pollution control strategies. [ABSTRACT FROM AUTHOR]

This study investigates the radiation dose that humans receive from naturally occurring uranium-series radionuclides, with a focus on alpha-emitting polonium-210 (210Po), which has a half-life of 138.4 days. Polonium is efficiently absorbed by living organisms and is estimated to contribute approximately 7% of the total effective dose from ingested natural internal radiation. The primary source of atmospheric 210Po is the decay of radon-222 (222Rn), which precipitates onto land and water surfaces, including crops. In Cannabis sativa, 210Po accumulates primarily through direct deposition on leaf surfaces and from fertilizers, particularly phosphate fertilizers. This study examined 10 samples of dried hemp (Cannabis sativa L.) legally available in Poland, assessing 210Po concentrations through radiochemical analysis. Various consumption methods were analyzed, including smoking with a glass pipe, a water pipe (bong), a cigarette (joint or spliff), and vaporization. The desorption of 210Po during combustion and vaporization was measured, revealing significant differences based on the method used. Results showed that smoking with a glass pipe resulted in the highest desorption of 210Po (approximately 80%), while water pipe and blunt smoking exhibited lower desorption rates (around 40%). The efficiency of 210Po adsorption in filters varied, with water filters showing about 8% absorption and cellulose filters about 20%. Vaporization results indicated that the desorption of 210Po increased with temperature. These findings underscore the importance of considering the method of consumption when calculating the radiation dose from 210Po, as the differences can significantly impact the accuracy of dose assessments. The study highlights the need for further research to optimize safety guidelines for cannabis consumption in relation to radioactive contaminants. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Latinoamericano y del Caribe de Plantas Medicinales y Aromáticas is the property of Universidad de Santiago de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Soil organic matter plays an important role in the long-term "locking" of organic contaminants in soil environment. Recently, microbialderived organic matter have been recognized as essential components of stabilized soil carbon pools. However, the contribution of microbial-derived organic matter to sorption of organic contaminants remains unclear. Methods: Here, we obtained microbial-derived organic matter-mineral composites by inoculating model soil (a mixture of hematite and quartz sand (FQ) or montmorillonite and quartz sand (MQ)) with natural soil microorganisms and different substrate-carbon (glycine (G), glucose (P), or 2, 6-Dimethoxyphenol (B)), which were named GF, PF, BF, GM, BM, and PM, respectively. Batch sorption/ desorption experiments were conducted for phenanthrene (PHE) and ofloxacin (OFL) on the composites. Results and Discussion: The composites cultured with 2,6-dimethoxyphenol had the highest carbon content (0.98% on FQ and 2.11% on MQ) of the three carbon substrates. The carbon content of the composites incubated with MQ (0.64%-- 2.11%) was higher than that with FQ (0.24%--0.98%), indicating that montmorillonite facilitated the accumulation of microbial-derived organic matter owing to its large specific surface area. The sorption of PHE by microbial-derived organic matter was mainly dominated by hydrophobic partitioning and π-π conjugation, whereas the sorption of OFL was mainly dominated by hydrophobic hydrogen bonding and π-π conjugation. The sorption of OFL onto the composites was more stable than that of PHE. Microbial-derived organic matter -mineral composites can reduce the risk of organic contaminant migration in soil, particularly ionic organic contaminants. [ABSTRACT FROM AUTHOR]

We report a sulfonated covalent organic framework (COF) capable of atmospheric water harvesting in arid conditions. The isothermal water uptake profile of the framework was studied, and the network displayed steep water sorption at low relative humidity (RH) in temperatures of up to 45 °C, reaching a water uptake of 0.12 g g−1 at 10 % RH and even 0.08 g g−1 at just 5 % RH, representing some of the most extreme conditions on the planet. We found that the inclusion of sulfonate moieties shifted uptake in the water isotherm profiles to lower RH compared to non‐sulfonated equivalents, demonstrating well the benefits of including these hydrophilic sites for water uptake in hot, arid locations. Repeated uptake and desorption cycles were performed on the material without significant detriment to its adsorption performance, demonstrating the potential of the sulfonated COF for real‐world implementation. [ABSTRACT FROM AUTHOR]

Aprotic Li‐CO2 batteries suffer from sluggish solid‐solid co‐oxidation kinetics of C and Li2CO3, requiring extremely high charging potentials and leading to serious side reactions and poor energy efficiency. Herein, we introduce a novel approach to address these challenges by modulating the reaction pathway with tailored Pt d‐electrons and develop an aprotic Li‐CO2 battery with CO and Li2CO3 as the main discharge products. Note that the gas‐solid co‐oxidation reaction between CO and Li2CO3 is both kinetically and thermodynamically more favorable. Consequently, the Li‐CO2 batteries with CoPt alloy‐supported on nitrogen‐doped carbon nanofiber (CoPt@NCNF) cathode exhibit a charging potential of 2.89 V at 50 μA cm−2, which is the lowest charging potential to date. Moreover, the CoPt@NCNF cathode also shows exceptional cycling stability (218 cycles at 50 μA cm−2) and high energy efficiency up to 74.6 %. Comprehensive experiments and theoretical calculations reveal that the lowered d‐band center of CoPt alloy effectively promotes CO desorption and inhibits further CO reduction to C. This work provides promising insights into developing efficient and CO‐selective Li‐CO2 batteries. [ABSTRACT FROM AUTHOR]

AbstractA simple needle-trap device (NTD) coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine trace levels of nitrobenzenes (NBs) in workplace air. The NTD with sorbent inside the needle was employed for the quantification of nitrobenzene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, o-nitrochlorobenzene, m-nitrochlorobenzene, and p-nitrochlorobenzene. The optimum temperature and time for desorption of analytes were 270 °C and 4 min, and parameters such as sampling flow rate, breakthrough volume, and storage capability were also optimized. The limits of detection and quantification were in the ranges of 1.8 × 10−4–1.1 × 10−3 and 5.9 × 10−4–3.6 × 10−3 mg m−3, respectively. The developed protocol was successfully applied for the determination of NBs in vehicle repair plants where the highest detected concentration was 0.11 mg m−3. The established NTD-GC-MS generally applies to monitoring trace levels of NBs in the air. [ABSTRACT FROM AUTHOR]

Wastewater produced in beryllium mining seriously affects ecological balance and causes great environmental pressure. We designed a novel porous lotus leaf biochar modified with PO43−/NH4+ multifunctional groups (MLLB) and used it for beryllium(Be) removal from beryllium mining wastewater. Kinetic and thermodynamic experiments showed that the adsorption capacity (Qe) of Be with MLLB from the simulated beryllium mining wastewater could reach 40.38 g kg−1 (35 °C, pH = 5.5), and the adsorption process was spontaneous and endothermic. The dispersion coefficient Kd of Be with MLLB was 2.6 × 104 mL g−1, which proved that MLLB had strong selective adsorption capacity for Be. Phosphoric acid, ammonia, and hydroxyl groups on the MLLB surface would complex with Be to form Be(OH)2 and Be(NH4)PO4 complexation products, which implied that surface complexation and precipitation reactions might co-existed in the adsorption process. The above results showed that MLLB could effectively adsorb Be and prevent beryllium exposure in a beryllium mining process. [ABSTRACT FROM AUTHOR]

Background: The widely adopted use of charred biomass for agronomic and environmental purposes; and the reported positive and deleterious effects necessitated the need for this study to ascertain the potential causes of the erratic results surrounding the use of charred biomass in agriculture and the environment. A batch sorption experiment was carried out to determine the sorptive and desorptive capacity of bone char and biochar on nitrate, ammonium, phosphate and sulphate concentrations in a loamy sand soil. The potential agronomic and environmental implications of the sorption data were also discussed. Results: The results indicated that bone char is richer in nutrient composition than biochar, with 70% more ability to sorb nutrients. The bone char and biochar sorption isotherms conformed to the H-curve isotherm type. Bone char and biochar have multiple layers of adsorption sites. Nutrient adsorption maxima, binding energy, and maximum buffering capacities of the soil were increased with the addition of bone char and biochar. The unamended soil was observed to retain as low as 6% of added nitrate to as much as 58% of added phosphate, while bone char retained 56% of added sulphate, 47% of phosphate, 76% nitrate and 64% of ammonium. Generally, bone char retained 60.6% of the added nutrients, while biochar retained 40.7% of the nutrients. The addition of bone char led to a 45.8% increase in the nutrient retention ability of the soil and a 36.1% increase with the addition of biochar. Conclusion: The nutrient sorption characteristics of biochar should be studied prior to its use as a soil nutrient amendment. It was concluded that bone char or biochar is a potential soil nutrient immobilizer; hence, applications for agronomic purposes should take cognizance of the native soil fertility so as to appropriately add fertilizer input before use. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) ferroelectrics usually exhibit instability or a tendency toward degradation when exposed to the ambient atmosphere, and the mechanism behind this phenomenon remains unclear. To unravel this affection mechanism, we have undertaken an investigation utilizing NH3 and two-dimensional ferroelectric SnS. Herein, the adsorption and desorption of NH3 molecules can reversibly modulate the electrical properties of SnS, encompassing I–V curves and transfer curves. The response time for NH3 adsorption is approximately 1.12 s, which is much quicker than that observed in other two-dimensional materials. KPFM characterizations indicate that air molecules' adsorption alters the surface potentials of SiO2, SnS, metal electrodes, and contacts with minimal impact on the electrode contact surface potential. Upon the adsorption of NH3 molecules or air molecules, the hole concentration within the device decreases. These findings elucidate the adsorption mechanism of NH3 molecules on SnS, potentially fostering the advancement of rapid gas sensing applications utilizing two-dimensional ferroelectrics. [ABSTRACT FROM AUTHOR]

A technology is developed for manufacturing planar microfluidic chips (MFCs) based on Silgard 8040, encompassing template fabrication, mold production, sealing, and adsorbent filling. These MFCs, filled with a Porapak-Q adsorbent, facilitate sample preparation and calibration under uniform conditions, integrating both sample collection and preconcentration stages. Experimental investigations have identified optimal conditions for acetone preconcentration using Silgard 8040-based MFCs, achieving a maximum concentration factor of 43 at adsorption temperature (Tads) of 0°C, desorption temperature (Tdes) of 70°C, adsorption volume (Vads) of 45 mL, and desorption time (tdes) of 1 s. The feasibility of using MFCs for sample collection and preparation, taking into account sample storage time, has been evaluated. The procedure maintains accuracy within 6–10% over 8 h without a necessity for additional drying of the collected samples from exhaled air. [ABSTRACT FROM AUTHOR]

Sodium alginate beads were explored as an adsorbent for exclusion of CV dye in batch mode by optimizing various parameters such as solution pH, effect of dye concentration, adsorbent's dose, contact time, and temperature. Experimental results revealed that maximum sorption, i.e., 97% was obtained at pH 12 in 20 minutes of contact time, 0.4 g of beads for 10 mL of dye solution at 30 °C. Characterization of sodium alginate beads confirmed that hydroxyl, carboxyl, amine, and sulfate functional groups are involved in dye adsorption on heterogeneous and porous surface of adsorbent. Isotherm study shows that Freundlich model fits best to experimental data having highest possible adsorption capacity of 4.797 mg g − 1 . Further, kinetic study revealed that pseudo-second order model plays a significant role in adsorption mechanism with R 2 = 0.9996. Suitability of each model is also checked by five error analysis models namely Hybrid, MPSD, EABS, ERRSQ, and ARE. Thermodynamic studies implied that CV dye adsorption on sodium alginate beads was spontaneous and endothermic in nature as confirmed from Δ G = −7.8 to −5.8 kJ mol−1 and Δ H = 10.201 kJ mol−1, respectively. Results also show that 92% of dye adsorption take place with tap water. Based on experimental outcomes, it has been concluded that sodium alginate beads are an excellent adsorbent to remove the CV dye from the solution. [ABSTRACT FROM AUTHOR]

Multifunctional superparamagnetic magnetite/hydroxyapatite (Fe 3 O 4 /Ca 10 (PO 4) 6 (OH) 2 or MHAp) nano-composites were synthesized via a facile two-step co-precipitation method at room temperature. These magnetic nano-composites underwent heat treatment at various temperatures ranging (400°, 600°, and 900 °C), which were subsequently utilized as nanosorbents for removing Pb2+ ions. The XRD data revealed that both the magnetite and hydroxyapatite synthesized were in a pure phase. In the Fe 3 O 4 /HAp composites, there was an augmentation in the intensity peak of hydroxyapatite observed up to 600 °C. However, at 900 °C, a calcium iron phosphate phase emerged, and magnetite (Fe 3 O 4) transitioned into the hematite (Fe 2 O 3) phase. Elevating the heat treatment enhanced the crystallinity of the developed Fe 3 O 4 /HAp composites while diminishing the surface area. The prepared nanocomposites exhibited high adsorption efficiency across a wide pH range, with an optimal pH of 5.5. Notably, the adsorption rate of Pb2+ reached 94 % within the first 5 min, with complete metal adsorption progressively at 60 min. The kinetic and isotherm analysis of the adsorption process revealed that pseudo-second-order model and Langmuir model agreed well with the adsorption process. Also, FAH 0 demonstrated the highest adsorption capacity (263.2 mg/g) for Pb2+ ions. Furthermore, the Fe 3 O 4 /HAp composite NPs exhibited remarkable recyclability even after five cycles of reuse; retaining an efficiency of over 96 %, and allowing for easy separation without a significant loss of adsorption efficiency. The results of the current desorption study underscore the promising practical applications of these nano-composites in decontaminating aqueous media. [ABSTRACT FROM AUTHOR]

This study investigates the impact of porosity distribution on the hydrogen storage performance of metal hydride (MH) reactors through numerical simulations. Firstly, the effects of different porosities on heat and mass transfer characteristics during hydrogen adsorption and desorption processes were analyzed. The results indicate that with increasing porosity, the hydrogen storage and release rates improved, but the hydrogen storage density decreased. To enhance reactor performance while maintaining hydrogen storage density, the bed porosity distribution was optimized. The optimization results showed that the hydrogen storage and release times of the MH reactor were reduced by 57.15% and 29.70%, respectively, at the same hydrogen storage density. Moreover, the optimized structure exhibited excellent hydrogen storage and release performance under different operating conditions, demonstrating its potential advantages in practical applications. • MH bed porosity significantly affects heat and mass transfer performance. • Bed porosity distribution is optimized by Monte Carlo algorithm. • Hydrogen storage and release times are reduced by 57.15% and 29.7%. • Optimized structure shows superior performance under various conditions. [ABSTRACT FROM AUTHOR]

Sulfur dioxide (SO2) emissions from ship exhausts pose serious health and environmental concerns. Herein, the SO2 absorption and desorption characteristics of tertiary amines with different functional groups were explored under simulated ship exhaust gas conditions. Tertiary amines with electron‐donating groups had superior absorption performance to those with electron‐withdrawing groups, and highly polar absorbents exhibited enhanced SO2 absorption loading. Dimethylaniline (DMA) showed excellent desorption performance, outperforming other absorbents (amino acids, ionic liquids, and deep eutectic solvents) in terms of cyclic capacity. Thus, tertiary amines, especially DMA, can be potentially used for the prevention of SO2 emissions from ship exhausts and other desulfurization applications. [ABSTRACT FROM AUTHOR]

Three MnCeTiOx catalysts with the same composition were prepared by conventional co-precipitation (MCT-C), reverse co-precipitation (MCT-R), and parallel co-precipitation (MCT-P), respectively, and their low-temperature SCR performance for de-NOx was evaluated. The textural and structural properties, surface acidity, redox capacity, and reaction mechanism of the catalysts were investigated by a series of characterizations including N2 adsorption and desorption, XRD, SEM, XPS, H2-TPR, NH3-TPD, NO-TPD, and in situ DRIFTs. The results revealed that the most excellent catalytic performance was achieved on MCT-R, and more than 90% NOx conversion can be obtained at 100–300 °C under a high GHSV of 80,000 mL/(gcat·H). Furthermore, MCT-R possessed optimal tolerance to H2O and SO2 poisoning. The excellent catalytic performance of MCT-R can be attributed to its larger BET specific surface area; higher contents of Mn4+, Ce3+, and adsorbed oxygen species; and more adsorption capacity for NH3 and NO. Moreover, in situ DRIFTs results indicated that the NH3-SCR reaction follows simultaneously the Langmuir–Hinshelwood and Eley–Rideal mechanisms at 100 °C. By adjusting the adding mode during the co-precipitation process, excellent low-temperature de-NOx activity of MCT-R can be obtained simply and conveniently, which is of great practical value for the preparation of a MnCeTiOx catalyst for denitrification. [ABSTRACT FROM AUTHOR]

This study investigates methods to enhance the efficiency of CO2 capture using organic amine absorption and compares the performance of traditional and novel amine solvents. It reviews various single-component and mixed amine absorbents, as well as catalysts used in these methods, highlighting the superiority of mixed amine absorbents over single-component amine absorbents in CO2 absorption and desorption. Additionally, the study explores the catalytic mechanisms and effects of catalysts in the CO2 absorption/desorption process with amine solvents and provides an outlook on future research directions. The aim is to promote the widespread adoption of organic amine absorption technology in industrial applications and to contribute to the development of more sustainable and efficient CO2 capture technologies. [ABSTRACT FROM AUTHOR]

This paper synthesized a stytypyridine (LSL-030-bd) resin with small particle size and uniform distribution to recover molybdenum resources leached during neutral in-situ leaching of uranium. The batch experiment results show that the LSL-030-bd ion exchange resin produced had the highest U(VI) adsorption capacity at pH 7.0, reaching 187.20 mg·g−1. At pH 3.0, LSL-030-bd resin adsorbed 180.17 mg·g−1 of Mo(VI). At pH 7.0, the resin exhibited the highest separation coefficient for uranium and molybdenum, with a KD value of 9.08. The resin's adsorption of U(VI) is a spontaneous endothermic process involving monolayer adsorption that combines physical and chemical adsorption. The adsorption of Mo(VI) by the resin is an exothermic process that is not spontaneous. It involves monomolecular layer adsorption with hydrogen bonding as the primary chemical force. By desorbing molybdenum with NH4SCN, followed by utilizing a mixed solution of NH4HCO3 and (NH4)2CO3 to desorb uranium, a step-by-step desorption process may be achieved to separate and purify uranium and molybdenum. [ABSTRACT FROM AUTHOR]

The present investigation aims to study adsorption-desorption behavior of glyphosate and tricyclazole in rice straw-compost biomixtures. To enhance pesticide adsorption and performance of the bio-purification system, rice straw-compost (BM) biomixture was mixed with wheat straw biochar (WBC, 1% and 5%), and adsorption of both pesticides in control (BM) and WBCBM(1%) and WBCBM(5%) biomixtures was compared. The kinetics study suggested that the pseudo-second-order model best explained the time-dependent adsorption of both pesticides and intraparticle adsorption was not the rate-determining step. Tricyclazole was more sorbed than glyphosate in all biomixtures which can be attributed to its lower water solubility. The WBC increased the sorption of both pesticides, but the effect varied with the nature of pesticides and biochar content. The adsorption coefficient values in BM, WBCBM(1%), and WBCBM(5%) biomixtures were 26.74, 38.16, and 51.97 (glyphosate) and 38.07, 59.94, and 84.54 (tricyclazole), respectively. The adsorption data was subjected to the Freundlich, the Langmuir, and the Temkin isotherms, and among them, the Freundlich isotherm best explained pesticide adsorption behavior. Desorption results suggested that the adsorption of glyphosate was more irreversible than tricyclazole and depended upon initial pesticide concentration. This study suggested that biochar mixed rice straw-compost biomixtures can be exploited in bio-purification systems for glyphosate and tricyclazole. [ABSTRACT FROM AUTHOR]

The article presents the results of experimental studies of the sorption and desorption of rare-earth metal (REM) cations by the Co-bearing ferromanganese crusts of the Govorov Guyot. It has been established that the REM cations are sorbed on the CFC ore minerals (Fe-vernadite, vernadite, Mn-feroxyhite, and goethite. The crusts are characterized by high exchange capacity (1.78–3.57 mg-equiv/g, which increases in the following series: (Dy < Gd < Lu < Sm < Nd < Y, La < Eu) Ce. The REM cation sorption proceeds by the irreversible ion-exchange equivalent mechanism. The exchange complex of ore minerals consists of Na+, K+, Ca2+, and Mg2+ cations, which contribute 97‒98% to their total capacity. The crusts are characterized by the group sorption of REM cations from multicomponent water solutions of metal salts. The selectivity of manganese and ferruginous minerals of crusts to REM cations is significantly higher than to the main cations of ocean water. Experimental data on the desorption of sorbed REM cations with the NaCl solution suggest their irreversible sorption by ore minerals and strengthening of the chemical bond of sorbed REM cations with the main structural elements of these minerals over time. An important property of ore minerals, primarily manganese minerals, is their chemical and structural stability in aqueous electrolyte solutions, suggesting the repeated use of FMC as sorbents of REM cations. [ABSTRACT FROM AUTHOR]

Well shut-in time significantly affects the production performance of shale-gas-well. However, interaction between shale powders and fracking fluid on methane desorption has been rarely reported. In this work, based on the volume method following Boyle's law under higher pressure, the experimental setup was conducted to obtain the adsorption and desorption isotherms to explore the effect of different shut-in times (including 0, 1, 3, 5, 10, and 30 days) on methane desorption. We fitted the methane adsorption and desorption isotherms by the Freundlich model, and the results show that the interaction can obviously impact desorption isotherm, desorption efficiency and adsorbed phase methane content. The inflection points of the constant k and n reduction curves, desorption efficiency reduction curve and adsorbed gas content reduction curve all occur when the interaction time is to 10 days, indicating that 10 days is the best value for the interaction between slick water and gas shale. The results provide an essential supplement that can help elucidate the impact of shut-in time on gas-shale-well production performance experimentally. [ABSTRACT FROM AUTHOR]

This study developed carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) as sorbents to extract flavonoids from grapefruit peel. The impact of solution pH and desorption conditions on extraction efficiency was investigated. In addition, Fourier transforms infrared spectroscopy, thermogravimetry, UVvisible spectroscopy, and scanning electron microscopy were used to characterize the carbon nanotubes. After five cycles, the desorption percentage of flavonoids was 82.7 %. HPLC analysis indicated that naringin was the dominant flavonoid in the grapefruit extracts, followed by rutin and quercetin. Insights into the adsorption mechanism of naringin to the MWCNT-COOH were obtained using the Freundlich isotherm equation to model the results. The carbon nanotubes developed in this study offer a cost-effective and straightforward method of extracting valueadded functional ingredients from food waste, thereby improving the sustainability and economic viability of the food supply. [ABSTRACT FROM AUTHOR]

A humidity sensor array can be used in applications requiring non-contact sensing and contactless interface localization, which became a significant area of research after COVID-19 and reduced the risk of bacterial transmission associated with conventional touch displays. In this study, a thin film humidity sensor has been designed using calcium (Ca) doped zinc ferrite (ZnFe2O4) nanomaterial, which has been prepared by the sol-gel auto-ignition process. The synthesized nanomaterial was characterized using Powder X-Ray Diffraction (PXRD), Fourier Transform Infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-Ray (EDX) techniques. The doping of Ca reduces the crystallite size and increases the lattice constant. Attempts have been made to determine the different humidity sensing parameters. The developed humidity sensor has a response time of 12 seconds and a recovery time of 66 seconds. The developed humidity sensor has good repeatability and a negligible aging effect. [ABSTRACT FROM AUTHOR]

[Display omitted] • A unique W-doped NiS x /Ni@Cu heterointerface was developed by electrodeposition. • W-doped NiS x /Ni heterointerface can lower the HER kinetic barrier. • The W-NiS x /Ni@Cu exhibits an attractive HER activity with a low overpotential of 38 mV at 10 mA cm−2. • The DFT calculations reveal the enhanced water dissociation and H intermediate desorption. Promoting water dissociation and H intermediate desorption play a pivotal role in achieving highly efficient hydrogen evolution reaction (HER) in alkaline media but remain a great challenge. Herein, we rationally develop a unique W-doped NiS x /Ni heterointerface as a favorable HER electrocatalyst which was directly grown on the Cu nanowire foam substrate (W-NiS x /Ni@Cu) by the electrodeposition strategy. Benefiting from the rational design of the interfaces, the electronic coupling of the W-NiS x /Ni@Cu can be efficiently modulated to lower the HER kinetic barrier. The obtained W-NiS x /Ni@Cu exhibits an enhanced HER activity with a low overpotential of 38 mV at 10 mA cm−2 and a small Tafel value of 27.5 mV dec−1, and high stability during HER catalysis. In addition, in-situ Raman spectra reveal that the Ni2+ active sites preferentially adsorb OH intermediate. The theoretical calculation confirms that the water dissociation is accelerated by the construction of W-NiS x /Ni heterointerface and H intermediate desorption can be also promoted by H spillover from S active sites in W-NiS x to Ni active sites in metal Ni. This work offers a valuable reference for rational designing heterointerface of electrocatalysts and provides an available method to accelerate the HER kinetics for the ampere-level current density under low overpotential. [ABSTRACT FROM AUTHOR]

The increasing emphasis on environmental sustainability and the demand for eco‐friendly practices have led to a surge in interest in natural products, particularly natural dyes, across industries, including textiles. Curcumin, extracted from the turmeric plant, has gained widespread application not only for its vibrant colour characteristics but also for numerous therapeutic properties, serving as an antioxidant, anti‐inflammatory agent, and promoting wound‐healing effects. This study aims to understand the physical and chemical phenomena associated with the adsorption and desorption of turmeric extract and its active principles on cotton and polyamide fibres through mathematical models, with the goal of expanding textile applications. Dyeing experiments revealed adsorption equilibrium times of less than 25 min for both fibres, with the pseudo‐second‐order model providing the best fit for dyeing kinetics, suggesting control through the chemisorption process. The Freundlich model better suited cotton adsorption isotherms (R2 = 0.778), while the Langmuir model fit well for polyamide (R2 = 0.981). Thermodynamic parameters indicated non‐spontaneous interactions between curcumin and cotton, with an endothermic process, and an exothermic and spontaneous process for polyamide. Friction and water tests indicated greater colour resistance for polyamide, with grades exceeding 4. Desorption tests in 100% ethanol solution showed a total release of only 0.88% and 0.97% for polyamide and cotton, respectively, sustained for 12 h, fitting the Higuchi mathematical model, indicating a purely diffusive release process. These results demonstrate the potential of curcumin dye for achieving high dye exhaustion percentages in natural and synthetic fabrics and sustained release properties. [ABSTRACT FROM AUTHOR]

Understanding drug behavior within the skin, especially for photosensitive compounds, is crucial for developing effective and safe topical therapies. This study employs Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI-MSI) and Liquid Chromatography-Mass Spectrometry (LC-MS/MS) to investigate the skin permeation and photostability of selumetinib, a MEK inhibitor used in treating type 1 neurofibromatosis (NF1). The highest amounts of selumetinib in the skin sections were obtained when using the gel formulation, suggesting that it is to be preferred to cream formulations to achieve higher permeation of the drug. Our study also revealed that selumetinib is amenable to photodegradation in ex vivo skin explants, and yields one main degradation product, whose degradation is likely triggered by hydrogen abstraction. MALDI-MSI results showed selumetinib and its degradation product concentrate in skin appendages, indicating these structures might serve as drug reservoirs, potentially prolonging retention and efficacy. This study demonstrates that combining MALDI-MSI with LC/MS-MS can highly contribute to the characterization of the fate of photosensitive compounds in the skin, an essential prerequisite to the development of compound-specific photoprotective measures. It will also pave the way for innovative topical delivery strategies for NF1 treatment. [ABSTRACT FROM AUTHOR]

Both the aquatic ecosystem and human health are at risk from radioactive elements like uranium(VI) (U(VI)) and thorium(IV) (Th(IV)). Therefore, their elimination and removal from water is of vital importance. In this study, Sargassum aquifolium macroalgae (SAM) powder was used to remove U(VI) and Th(IV) ions from aqueous solution as a new, inexpensive, and readily available biosorbent. The prepared SAM was characterized using several instruments including FTIR, XRD, TGA, and SEM-EDXS. To evaluate the sorption performance, five operating conditions were investigated, namely, solution pH, sorbent mass, contact time, metal concentration, and temperature using the batch technique. The pseudo second order equation adequately describes the sorption of U(VI) and Th(IV) ions by SAM sorbents, according to sorption kinetic studies. The sorption isotherm results corresponded well with the Langmuir sorption model, with U(VI) and Th(IV) having maximal sorption capacities of 20.4 mg g−1 and 24.1 mg g−1, respectively. Parameters of thermodynamics indicated that the sorption of U(VI) and Th(IV) ions onto SAM is possible, spontaneous, exothermic, and entropy-driven. According to desorption tests, the most effective desorption reagent for both metal cations is 0.1 mol L−1 HNO3. This research has shown that the treated SAM sorbent has high efficiency in the removal of U(VI) and Th(IV) ions from real wastewater samples. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) capture technologies are crucial for mitigating climate change, with post‐combustion capture (PCC) using chemical absorption being a leading method. However, the energy‐intensive solvent regeneration process presents a significant challenge, consuming up to 50% of the total energy in carbon sequestration. Despite extensive research on absorption, desorption studies remain limited. This study focuses on the desorption analysis through experimental runs in a pilot‐scale tray column with varying flow rates, validating an Aspen Plus model. The research compares the impact of the number of stages, feed stage position, column pressure, and reflux ratio between equilibrium and rate‐based models. The findings reveal enhanced desorption efficiency through optimized operational conditions, including reduced flow rates, additional equilibrium stages, feeding stage positioning closer to the condenser, elevated pressures, and lower reflux ratios. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]