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A multipronged approach to the refined mechanochemical synthesis of the semiconductor kesterite Cu2ZnSnS4 with minimal quantities of adventitious oxygen as well as to optimizing handling procedures from that angle is described. Three precursor systems are used to provide a pool of freshly made cubic prekesterite nanopowders with no semiconductor properties and the thermally annealed at 500 °C tetragonal kesterite nanopowders of the semiconductor. Based on the previously reported high propensity of such nanopowders to long-term deteriorating oxidation in ambient air, suitable modifications of all crucial synthesis steps are implemented, which are directed toward excluding or limiting the materials’ exposure to air. The nanopowders are comprehensively characterized by powder XRD, FT-IR/Raman/UV-Vis spectroscopies, solid-state 65Cu/119Sn MAS NMR, TGA/DTA-QMS analysis, SEM, BET/BJH specific surface area, and helium density determinations, and, significantly, are directly analyzed for oxygen and hydrogen contents. The important finding is that following the anaerobic procedures and realistically minimizing the materials’ exposure to air in certain manipulation steps results in the preparation of better oxidation-resistant nanopowders with a dramatic relative decrease in their oxygen content than previously reported. The adherence to the strict synthesis conditions that limit contact of the no-oxygen-containing kesterite nanopowders with ambient air is emphasized.

Electrodeposited Mo‐rich NiMo catalysts offer enhanced catalytic activity for the alkaline hydrogen evolution reaction (HER) and provide an electrically conductive, binder‐free substrate connection, making them promising catalysts for green hydrogen production. However, creating Mo‐rich deposits is challenging, as the codeposition process typically favors Ni. Optimal deposition conditions for Mo‐rich NiMo catalysts remain insufficiently explored. This article investigates Mo‐rich NiMo electrodeposition from an ammonia‐free citrate bath using NaSO4 as a chlorine‐free support electrolyte. The effects of the deposition parameters, 1) sodium molybdate concentration in the electrolyte, 2) deposition current density, and 3) enhanced mass transport via working electrode rotation on the alkaline HER activity, were studied. The electrodeposits, containing 44–66 wt% Mo, exhibited increased surface area due to a rough, cracked morphology and variable oxygen content of the catalyst. The oxygen content was linked to HER activity, revealing an inhibiting effect. The lowest overpotential of 118 mV at −10  mA cm−2 for the alkaline HER was achieved using an electrolyte with 0.02 mol L−1 sodium molybdate, a deposition current density of 600 mA cm−2, without electrode rotation. Respective samples combined a favorable Ni:Mo ratio comprising 56 wt% Mo content with increased surface area and low oxygen content. This study explores Mo‐rich NiMo electrodeposition for enhancing alkaline hydrogen evolution reaction (HER), for green hydrogen production. By tuning deposition parameters, NiMo with 44–66 wt% Mo was obtained, showing enhanced HER activity and surface area. Oxygen in the catalyst hindered performance but was mitigated through adjusting deposition parameters.

The energy efficiency in the debutanizer reboiler combustion can be monitored from the oxygen content of the flue gas of the reboiler. The measurement of the oxygen content can be conducted in situ using an oxygen sensor. However, soot that may appear around the sensor due to the combustion process in the debutanizer reboiler can obstruct the sensor’s function. In-situ redundancy sensors’ unavailability is a significant problem when the sensor is damaged, so measures must be made directly by workers using portable devices. On the other hand, worker safety is a primary concern when working in high-risk work areas. In this paper, we propose a software-based measurement or soft sensor to overcome the problems. The radial basis function network model makes soft sensors adapt to data updates because of their advantage as a universal approximator. The estimation of oxygen content with a soft sensor has been successfully carried out. The soft sensor generates an estimated mean square error of 0.216% with a standard deviation of 0.0242%. Stochastics gradient descent algorithm with momentum acceleration and dimension reduction using principal component analysis successfully improves the soft sensors’ performance.

Aeration is a cost-effective and efficient method for increasing the available oxygen or dissolved oxygen content in water bodies, which is crucial for the existence of aquatic life. However, conventional techniques for estimating aeration in different hydraulic structures are time-consuming and incorrect ways to approximate aeration. Therefore, new, computationally more efficient, and more accurate methods are required. In this article, three machine learning models are presented: (1) ELM (extreme learning machine) model, (2) online sequential extreme learning machine model, and (3) I-ELM (incremental extreme learning machine) model. These models assess the air conditioning capacity of the three variants of Piano Key Weirs (PKWs), denoted as A, B, and C, about Cd, Cs, and Cu, which are the three most important parameters for aeration efficiency at different temperatures. The model performance is evaluated and compared based on mean squared error, root-mean-square error, correlation coefficient, mean absolute error, and Nash–Sutcliffe efficiency. This research concludes that I-ELM is the best-performing model for complete available data that are time invariant.

Actual paperwork reflects obtained results of technological analyse of reducing oxygen content in steel for pipe manufacturing, enterprised in a steel furnance equipped with a triple aggregate EAF-LF-VD. Oxygen content was measured during manufacturing process in Loading Furnance and Vacuum Degasing and has been analysed in comparison with several parameters. The results are presented using Matlab through regression surfaces and correlation equations and highlights the influence of analysed factors on oxygen content variation in steel.

Air oxygen content, an essential index for measuring air quality, is affected by vegetation and the environment in the forest. However, the scientific understanding of the influential mechanism of air oxygen content in different vegetation types is still not clear. Focusing on four different vegetation types: broad-leaved forest, coniferous forest, coniferous and broad-leaved mixed forest, and non-forest land within Shimen National Forest Park, China, the temporal dynamics of air oxygen content and its relationship with four environmental factors (temperature, relative humidity, wind speed, and negative air ion concentration) in different vegetation types were explored based on path analysis and decision analysis. The results showed that there was a noteworthy impact of vegetation types on air oxygen content, with coniferous and broad-leaved mixed forest (21.33 ± 0.42%) presenting the highest levels. The air oxygen content indicated a fundamentally consistent temporal pattern across different vegetation types, with the highest diurnal variation occurring at noon. It reached its peak in August and hit its nadir in December, with summer > spring > autumn > winter. In broad-leaved forest, the air oxygen content was determined by temperature, wind speed, negative air ion concentration, and relative humidity; in both coniferous forest and coniferous and broad-leaved mixed forest, the air oxygen content was affected by temperature, wind speed, and relative humidity; in non-forest land, the air oxygen content was influenced by temperature and wind speed. Generally, temperature was the dominant factor affecting air oxygen content in different vegetation types, and its positive impact tremendously exceeded other environmental factors. Wind speed had a positive impact on air oxygen content in three forest communities but a negative effect on non-forest land. Relative humidity acted as a limiting factor for air oxygen content within three forest communities. Negative air ion concentration showed a significant positive correlation on air oxygen content in broad-leaved forest. Therefore, when planning urban forests to improve air quality and construct forest oxygen bars, it is recommended that the tree species composition should be given priority to the coniferous and broad-leaved mixed pattern. Meanwhile, make sure the understory space is properly laid out so that the forest microclimates are conducive to the release of oxygen by plants through photosynthesis.

Global climate change and persistent droughts lead to soil desertification, posing significant challenges to food security. Desertified lands, characterized by high permeability, struggle to retain water, thereby hindering ecological restoration. Sand, a natural resource abundant in deserts, inspired our proposal to design hydrophobic sand and construct Air-permeable Aquicludes (APAC) using this material. This approach aims to address issues related to the ecological restoration of desertified lands, food security, and the utilization of sand resources. Reclamation of desertified land and sandy areas can simultaneously address ecological restoration and ensure food security, with soil reconstruction being a critical step. This study investigated the effects of constructing an Air-permeable Aquiclude (APAC) using hydrophobic sand on rice yield and lodging resistance, using clay aquitard (CAT) and plastic aquiclude (PAC) as control groups. The APAC enhanced soil oxygen content, increased internode strength, and improved vascular bundle density, substantially reducing the lodging index and increasing yield. This research finds that the APAC (a) increased internode outer diameter, wall thickness, fresh weight, and filling degree; (b) enhanced the vascular bundle area by 11.11% to 27.66% and increased density; (c) reduced the lodging index by 37.54% to 36.93% (p < 0.01); and (d) increased yield to 8.09 t·hm−2, a rise of 12.05% to 14.59% (p < 0.05), showing a negative correlation with lodging index. These findings suggest that APAC has very good potential for desertified land reclamation and food security. In conclusion, the incorporation of hydrophobic sand in APAC construction considerably strengthens rice stem lodging resistance and increases yield, demonstrating considerable application potential for the reclamation of desertified and sandy land and ensuring food security.

Lei bamboo cultivation is an important economic activity in the Zhejiang province of China. However, extensive management practices such as organic mulching aimed at optimizing Lei bamboo production usually have a long-term negative impact on soil pH. Thus, it is important for novel management practices that consider not only bamboo production but also soil quality to be developed. In this study, we evaluated the effect of four conditions: organic mulching combined with aeration (MA), organic mulching and no aeration (MNA), aeration and no mulching (NMA), and control treatment (CK) on soil quality parameters and Lei bamboo shoot production. The Lei bamboo stands have been receiving similar treatments for 3–4 years, but for this study, organic mulch materials (rice husks, stalks, bamboo leaves, non-living plant biomass materials and plants biochar) were reapplied in October 2021 and soil sampling was done in April 2022. Our results showed that the average oxygen content at a sampling depth of 10 cm in CK, MA, and NMA was 21.6%, 21.7%, and 20.7%, respectively. However, when mulching was applied without aeration (MNA), soil oxygen content and pH were decreased by 6.3% and 0.7 units compared to CK. Moreover, for this treatment soil pH was as low as 4.28 at a depth of 30 cm. Nevertheless, when mulching was applied together with aeration (MA), all soil quality parameters, including the contents of organic matter and nitrogen were significantly increased (p < 0.05). For MA, soil pH was generally > 5.0 even at a depth of 30 cm. For all the treatment plots, the number of bamboo shoots that were produced after one month of treatment followed the sequence MA (591.0) > MNA (554.3) > NMA (305.7) > CK (53.3). Even though NMA and MNA treatments both improved bamboo growth by providing the required nutrients, we recommend the combined application of mulching and aeration (MA) for long-term Lei bamboo plantation management since the combination has the potential to improve nutrient supply and bamboo growth while retarding soil acidification.

In this work, magnesium-doped Sr2Fe1.2Mg0.2Mo0.6O6−δ and Sr2Fe0.9Mg0.4Mo0.7O6−δ double perovskites with excellent redox stability have been successfully obtained. The physicochemical properties including: crystal structure properties, redox stability, thermal expansion properties in oxidizing and reducing conditions, oxygen content as a function of temperature and transport properties, as well as the chemical compatibility with typical electrolytes have been systematically investigated. The in situ oxidation of reduced samples using high-temperature XRD studies shows the crystal structure of materials stable at up to a high-temperature range. The in situ reduction and oxidation of sinters with dilatometer measurements prove the excellent redox stability of materials, with the thermal expansion coefficients measured comparable with electrolytes. The oxygen nonstoichiometry δ of compounds was determined and recorded in air and argon up to 900 °C. Sr2Fe1.2Mg0.2Mo0.6O6−δ oxide presents satisfactory values of electrical conductivity in air (56.2 S·cm−1 at 600 °C) and reducing conditions (10.3 S·cm−1 at 800 °C), relatively high coefficients D and k, and good ionic conductivity (cal. 0.005 S·cm−1 at 800 °C). The stability studies show that both compounds are compatible with Ce0.8Gd0.2O1.9 but react with the La0.8Sr0.2Ga0.8Mg0.2O3−d electrolyte. Therefore, the magnesium-doped double perovskites with excellent redox stability can be potentially qualified as electrode materials for symmetrical SOFCs and are of great interest for further investigations.

—A statistical analysis is performed to determine the total oxygen content in pipe steel samples at the stage of continuous casting on a continuous casting machine (CCM) of the casting-and-rolling complex (CRC) at AO VMP. The microstructure of rolled steel samples is studied, and the chemical composition of nonmetallic inclusions is determined by electron-probe microanalysis. A laboratory analysis of samples of liquid steel and hot-rolled CRC steel is performed by the inert gas fusion method. The dependences between the time of metal residence in a ladle, the magnesium content in nonmetallic inclusions, and the average number of nonmetallic inclusions in rolled steel and the total oxygen content in liquid steel at the stage of continuous casting are built.