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Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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.)

The chemical behaviors of alkali and alkaline earth metal hydrides including LiH, KH, MgH2, CaH2, and BaH2 under nitrogen plasma differ significantly from one another, exhibiting an ammonia production trend that contrasts with that observed under thermal conditions. A prominent feature of KH is its ability to facilitate plasma-assisted N2 fixation without generating H2 byproduct, showing high atomic economy in utilization of hydride ions for N2 reduction. [ABSTRACT FROM AUTHOR]

The hypothesis was that low residual alkali after cooking would cause lignin re-precipitation during washing and in turn affect the subsequent oxygen delignification stage negatively. To test the hypothesis, kraft cooks were performed in lab-scale to different residual alkali levels, ranging from 5 to 15 g/L and the pulps were subjected to washing with either water or 0.1 M NaOH and then oxygen delignified. The results show that even at low residual alkali and washing with water, the pH in the liquor after washing was above 11 which is sufficiently high to keep lignin in solution. No effect of residual alkali level was observed on the performance of the oxygen delignification stage. [ABSTRACT FROM AUTHOR]

Bioactive glasses (BG) containing silicon, phosphorous, and boron have emerged as promising materials for bone tissue engineering. Modifying ions play a multifaceted role in BGs, influencing their structure, properties, and biological activity that depends on their size, charge, and coordination chemistry. This study investigates the addition of sodium borate (Na 2 B 4 O 7) to the 58S BG and the mixed alkali effect (MAE) resulting from incorporating Na and B ions into the CaO–SiO 2 –P 2 O 5 system. In specific concentrations, Na+ and Ca2+ ions function as network modifiers, introducing structural disruptions and generating defects that impact the glass transition temperature (T g), crystallization temperature (T c), hardness, and sintering characteristics. The physicochemical characterization of BGs confirms the incorporation of Na and B structures. Furthermore, the Na and B doped glass sample with a [Na/Si] ratio of 0.045 exhibits favorable properties for promoting cell attachment, including forming a hydroxyapatite (HAp) layer over the surface, thereby accelerating human placental mesenchymal stem cells (hPMSCs) proliferation. The findings demonstrate the potential of Na 2 B 4 O 7 incorporation in BG for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrate reduction reaction (NO3RR) is a process that requires the participation of eight electrons and nine protons. The regulation of active hydrogen (H*) supply and a deep understanding of related processes are necessary for improving the ammonia yield rate and Faradaic efficiency (FE). Herein, we synthesized a series of atomically precise copper‐halide clusters Cu2X2(BINAP)2 (X=Cl, Br, I), among which the Cu2Cl2(BINAP)2 cluster shows the optimal ammonia FE of 94.0 % and an ammonia yield rate of 373 μmol h−1 cm−2. In situ experiments and theoretical calculations reveal that halogen atoms, especially Cl in Cu2Cl2(BIANP)2, can significantly affect the distance of alkali metal‐ionized water on the catalyst surface, which can promote the water dissociation to enhance the localized H* enrichment for the continues hydrogenation of nitrate to ammonia. This work explains the role of H* in the hydrogenation process of NO3RR and the importance of localized H* enrichment strategy for improving the FEs. [ABSTRACT FROM AUTHOR]

Cyanotypes are known to de-colourize with alkalis; however, not much research has been done to regain the lost information. This research examines two possibilities to bring back the information: one is to utilize elemental mapping by X-ray fluorescence spectroscopy analysis to regain the image non-invasively, and the second, to treat the cyanotype with acidic solutions. Both methods brought back the image to the extent that the information could be obtained. As photo reproductions, one of their greatest values is the information they convey. This research could be significant in that it opens possibilities to regain the lost information. [ABSTRACT FROM AUTHOR]

In this work, a novel study was investigated in situ sample preparation using the green micro total analysis system (µTAS) without microchips for the determination of dapsone. The microchips have been replaced by capillary tubes with very small internal diameters. These capillary tubes are used in the field of human medicine. As a spectrophotometric reagent, 7-chloro-4-nitrobenzoxadiazole (NBD-Cl) was employed. The suggested approach was dependent on the desired medication, NBD-Cl, reacting in an alkali solution to produce a coloured adduct that had λmax = 468 nm. Investigations have been done into the several physical and chemical factors that affect the measurement, including sample volume, pH, flow rate, the reacting loop, and the volume and amount of NBD-Cl. This method shows the linearity range of 0.5 to 100 µg mL-1 with a coefficient of regression R² of 0.9989. The regression equation A = 0.0697C + 0.0034. Also, the limit of detection was 0.3998µg mL-1. The proposed system has been applied efficaciously to determine the presence of dapsone in medical preparations. [ABSTRACT FROM AUTHOR]

Based on investigated mechanical properties of alkali residue-based foamed concrete (A-FC), this paper presents a comprehensive examination of the microstructural features of A-FC and their impact on compressive properties. A detailed investigation of the compressive performance and pore structure characteristics was conducted through compression tests and low-field nuclear magnetic resonance (NMR) tests. The results demonstrate that the primary pore size in A-FC falls within the microscale, and the pores can be categorized into three types—gel pores, capillary pores, and air voids. In addition, the T2 spectrum of A-FC exhibits three distinct relaxation peaks, each of which is attributed to different water components, i.e., adsorbed water, pore water, and free water. As the pore size, air void ratio, and porosity increase, the compressive strength of A-FC decreases. The main reasons for the increased in strain in low-strength A-FC include compression at the bottom, internal stress dissipation through the pore structure, and changes in the failure mode. [ABSTRACT FROM AUTHOR]

The distribution of rare alkalis (Li, Rb, and Cs) is analyzed in spatially linked water objects of the Baikal geosystem: water of Baikal and its tributaries, underground water from boreholes and thermal springs, and the Angara River (the sole outlet), which are located in the Baikal rift zone. The rare alkali content differs significantly in some water objects, but the average and median contents are similar in the surface and deep water of Lake Baikal and the Angara River. The water of Barguzin thermal springs of the eastern shore of Lake Baikal contains the maximum amount of rare alkalis, but this affects the Baikal water insignificantly due to its natural self-cleaning and deep renewal of water during geodynamic movements. The similar rare alkali contents of Barguzin and some thermal springs of Kamchatka emphasize their indicator role in the genesis of water objects. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher 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.)

In Poland, the prevailing protocols for examining the alkali reactivity of aggregates are based on indirect methodologies such as petrographic appraisal, in addition to direct methodologies including the measurement of expansion in mortar and concrete specimens containing the aggregate under investigation. The available research methods exhibit certain deficiencies, which have been mitigated under the experimental conditions delineated in the novel accelerated approach for ascertaining the reactivity of aggregates, otherwise known as the MCPT – Miniature Concrete Prism Test. The methodology of MCPT has the potential to become an alternative for the existing procedures of quality assessment for both fine and coarse aggregates. This work presents the assessment results of the alkaline reactivity of indigenous fine quartz aggregate, examined in accordance with the protocols established by the Polish General Directorate for National Roads and Motorways along together the novel, expedited MCPT methodology. [ABSTRACT FROM AUTHOR]

Using large-scale molecular dynamics simulations, we investigate the surface properties of lithium, sodium, and potassium silicate glasses containing 25 mol % of alkali oxide. The comparison of two types of surfaces, a melt-formed surface (MS) and a fracture surface (FS), demonstrates that the influence of the alkali modifier on the surface properties depends strongly on the nature of the surface. The FS exhibits a monotonic increase of modifier concentration with increasing alkali size while the MS shows a saturation of alkali concentration when going from Na to K glasses, indicating the presence of competing mechanisms that influence the properties of a MS. For the FS, we find that larger alkali ions reduce the concentration of under-coordinated Si atoms and increase the fraction of two-membered rings, implying an enhanced chemical reactivity of the surface. For both types of surfaces, the roughness is found to increase with alkali size, with the effect being more pronounced for the FS than for the MS. The height–height correlation functions of the surfaces show a scaling behavior that is independent of the alkali species considered: The ones for the MS are compatible with the prediction of the frozen capillary wave theory while the ones for the FS show a logarithmic growth, i.e., on the nanoscale these surfaces are not self-affine fractals. The influence of the modifier on the surface properties are rationalized in terms of the interplay between multiple factors involving the size of the ions, bond strength, and charge balance on the surface. [ABSTRACT FROM AUTHOR]

The high shrinkage of metakaolin-based geopolymers (MKGs) dramatically limits their application as high-performance green cementitious materials. In this study, microscopic tests and microstructure analysis of the polymerization reaction products are employed to examine the drying shrinkage properties of MKG under different alkali equivalents. The results indicate an enhancement in the strength of MKG mortar with increasing alkali equivalent; however, it undergoes shrinkage in the later stages. Notably, the drying shrinkage increases with the alkali equivalent, mainly attributed to the fact that the increase in alkali equivalent does not change the types of hydration products in MKG. Instead, it promotes the dissolution of active silicon oxide and alumina in metakaolin (MK) particles, accelerating the hydration reaction process and, resulting in a higher amount of sodium aluminosilicate hydrated gel (N─ A─ S─ H) gel. Furthermore, the alkali equivalents modify the pore size distribution, leading to an increase in the 10–50-nm pore volume and capillary negative pressure, ultimately causing an increase in drying shrinkage. [ABSTRACT FROM AUTHOR]

An efficient approach to the synthesis of novel 2,3-diaryl-3,4-dihydro-2H-benzo[4,5]imidazo[2,1-b][1,3,4]thiadiazines via a base-catalyzed intramolecular cyclization of 2-arylmethylthio-N-arylidene-1H-benzo[d]imidazol-1-amines has been developed. The use of alkali is critical for the annulation of the thiadiazine ring. In the absence of strong bases, the starting compounds undergo deamination with elimination of benzonitrile and formation of 2-arylmethylthiobenzimidazoles. [ABSTRACT FROM AUTHOR]

The emergence of Li–SOCl2 batteries in the 1970s as a high-energy-density battery system sparked considerable interest among researchers. However, limitations in the primary cell characteristics have restricted their potential for widespread adoption in today's sustainable society. Encouragingly, recent developments in alkali/alkaline-earth metal–Cl2 (AM–Cl2) batteries have shown impressive reversibility with high specific capacity and cycle performance, revitalizing the potential of SOCl2 batteries and becoming a promising technology surpassing current lithium-ion batteries. In this review, the emerging AM–Cl2 batteries are comprehensively summarized for the first time. The development history and advantages of Li–SOCl2 batteries are traced, followed by the critical working mechanisms for achieving high rechargeability. The design concepts of electrodes and electrolytes for AM–Cl2 batteries as well as key characterization techniques are also demonstrated. Furthermore, the current challenges and corresponding strategies, as well as future directions regarding the battery are systematically discussed. This review aims to deepen the understanding of the state-of-the-art AM–Cl2 battery technology and accelerate the development of practical AM–Cl2 batteries for next-generation high-energy storage systems. [ABSTRACT FROM AUTHOR]

In order to screen high quality alfalfa varieties suitable for planting in northeast China, 130 alfalfa varieties at home and abroad and newly selected varieties were used as the research materials. The seeds at germination stage were alkali stress treated with 30 mmol/L Na2CO3 and 50 mmol/L NaHCO3, respectively. Comprehensive evaluation of alkali stress of alfalfa varieties were analyzed by detecting germination index and subordinate function analysis. The results showed that the average relative germination rates of 130 alfalfa species under Na2CO3 and NaHCO3 stress were 68.54% and 79.17%, respectively. The relative germination vigor were 57.30% and 65.78% respectively. The relative root length was 23.70% and 17.61%, respectively. The relative bud length was 53.21% and 46.37%, respectively. Through the analysis of membership function, it was found that the seeds of seven varieties of LJ112, LJ66, LJ33, 5010, DARA, Nongjing 1 and Juneng salt-tolerant had good germination trend under two alkali stresses. By calculating the comprehensive membership function values of 130 alfalfa varieties under two alkali stresses, it can be seen that Nongjing 1 and LJ33 have the best germination and growth under two alkali stresses. The study indicates that this experiment is beneficial for guiding the cultivation of alfalfa and providing germplasm resources for the breeding of alkali tolerance alfalfa varieties. [ABSTRACT FROM AUTHOR]

The purpose of this experiment was to improve the extraction rate of soluble dietary fiber (SDF) from wheat straw. The dietary fiber of wheat straw was modified by alkali high pressure oxidation method, and the effects of alkali addition, liquid-solid ratio, high pressure time and H2O2 addition on SDF extraction rate were explored by single factor method, and the treatment process was optimized by orthogonal design. The results showed that the optimal treatment process was 6% of NaOH addition, 6 mL/g of liquid-solid ratio, 40 min of high pressure time, and 6% of H2O2 addition. It was verified that the extraction rate of SDF under the optimal treatment was 10.29%, which was 181.92% higher than that of untreated wheat straw (3.65%) (P<0.05). The study indicates that alkali high pressure oxidation can effectively improve the extraction rate of SDF from wheat straw, which is conducive to the further development and utilization of wheat straw dietary fiber in animal production. [ABSTRACT FROM AUTHOR]

We previously used a grinder to prepare cellulose nanofibers (CNFs) that were then added to pulp to improve the wet strength of paper, with subsequent alkali treatment further improving its wet tensile strength. However, mass production of CNF using ultra-fine grinders is not feasible; moreover, fabricating paper sheets by first preparing CNFs and adding them to pulp is a complex process. Therefore, in this study, we directly fibrillated pulp using a refiner instead separately preparing CNFs, with the refined pulp used to make paper sheets, thereby simplifying the process. The resulting dried sheets were subsequently treated with 8 and 16 wt% NaOH, after which the co-reinforcing effect of the refiner and NaOH treatments on the wet tensile strength of paper was examined. Unexpectedly, wet tensile strength of 39 and 45 MPa was achieved. These values are higher than values obtained using the CNFs and NaOH treatment, and comparable to the dry strength of untreated and unrefined pulp sheet. Moreover, the dewatering time of the refiner-treated pulp was significantly shorter than that of the CNF-mixed pulp, which reduces the time required to prepare paper. This study demonstrated that refiner-treated pulp is more suitable than CNF-mixed pulp for improving paper wet strength. [ABSTRACT FROM AUTHOR]

BACKGROUND: Whole wheat steamed bread has been recommended for its potential nutritional benefits to human health. Given the positive role of both organic acid and alkali in improving dough development and product quality, the present study investigated the effects of neutralization by addition of alkali (Na2CO3) after dough acidification with traditional Jiaozi starter on the properties of whole wheat dough. RESULTS: The population of yeast and lactic acid bacteria and the acidification level of the dough increased significantly after fermentation with Jiaozi. Incorporation of alkali greatly improved the leavening capacity of the remixed dough and the quality of steamed bread. Jiaozi fermentation and alkali addition changed the water distribution patterns (T2) and affected the secondary structures of gluten protein, starch crystallinity and pasting properties. The storage modulus (G') of the dough increased significantly with the alkali addition, which could be attributed to the promoted cross‐linking of the gluten structure and the altered hydration state of the macromolecules. CONCLUSION: The results of the present study indicate that a combination of Jiaozi fermentation and alkali addition could improve the technological properties of whole wheat dough and the quality of steamed bread. The results will help us to further explore the potential application of moderate acidification and alkali addition in the production of leavened whole wheat products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Additive manufacturing, with its ability to assemble a variety of materials in complex and customized architectures, is developing rapidly. The integration of technologies and materials into a sustainable production, however, is still challenging. The present investigation offers new functional glass-based products, from nearly room temperature processing, based on direct ink writing (DIW) of pastes from 'light' alkali activation (2.5 M NaOH) of pharmaceutical glass waste, added with 20 wt% of TiO 2 nanoparticles. The inks were refined by the inclusion of porous glass microspheres (PGMs, 20–30 wt%), previously fabricated from fiber glass waste. Printed scaffolds, stabilized by simple drying (i.e. 'unfired'), were successfully applied in the photodegradation of methylene blue. The degradation efficiency reached 100% within 75 min, and the 3D-printed composites could be easily separated from the solution for subsequent reuse. The degradation efficiency declined only by 7.5%, after 5 cycles. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office 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.)

This study focuses on treating Guadua angustifolia bamboo fibers to enhance their properties for reinforcement applications in composite materials. Chemical (alkali) and physical (dry etching plasma) treatments were used separately to augment compatibility of Guadua angustifolia fibers with various composite matrices. The influence of these treatments on the fibers' performance, chemical composition, and surface morphology were analyzed. Statistical analysis indicated that alkali treatments reduced the tensile modulus of elasticity and strength of fibers by up to 40% and 20%, respectively, whereas plasma treatments maintain the fibers' mechanical performance. FTIR spectroscopy revealed significant alterations in chemical composition due to alkali treatments, while plasma-treated fibers showed minimal changes. Surface examination through Scanning Electron Microscopy (SEM) revealed post-treatment modifications in both cases; alkali treatments served as a cleanser, eliminating lignin and hemicellulose from the fiber surface, whereas plasma treatments also produce rough surfaces. These results validate the impact of the treatments on the fiber mechanical performance, which opens up possibilities for using Guadua angustifolia fibers as an alternative reinforcement in composite manufacturing. [ABSTRACT FROM AUTHOR]

Oil-water separation is important in waste-water treatment. Taking the advantage of the special wettability of Zein, an oil-water separation nanofibrous membrane with excellent separation efficiency and flux was prepared. To enhance the mechanical properties of Zein, Zein was electrospun with ES-11 alkyd soluble nylon (PA), which has excellent mechanical properties. The prepared Zein/PA fibrous membrane can realize on-demand oil-water separation, and substantially enhance the mechanical properties. The results show that the tensile stress and strain of the fibrous membrane reach 3.31 MPa and 64.79% when the proportion of PA reaches 35%. The separation efficiencies of different oil-water mixtures are above 98.5%, up to 99.6%, and the separation fluxes are up to 14 107 L/(m²·h). After 10 separation cycles, the separation efficiency and flux of the fibrous membrane keep as high as 98.7% and 13 287 L/(m²·h). The efficiency and flux of oil-water separation under acid, alkali and salt environments do not decrease significantly, indicating that the fibrous membrane has good resistance to acid, alkali and salt. [ABSTRACT FROM AUTHOR]

The difficulty of dyeing is a disturbing problem for the various application of polyimide fabrics. Alkali treatment has been widely used as a preliminary step before dyeing, denoted as a two‐bath method. With more attention being paid to energy resources, this work aims to explore more economical and environmentally friendly dyeing technology, combining the alkali treatment and the dyeing process together, named a one‐bath method. Surprisingly, the K/S value of the one‐bath dyed fabric is much higher than that of the two‐bath sample, in which the red colour value is enhanced by 59.9% for the one‐bath sample. As for the effect of dyeing on the physical properties, the two‐step method has been demonstrated to exert more severe damage on the fibre, with lower crystallinity and tensile strength. To explain such results, it is deduced that when alkali is added together with dyes, it can play a bridge role between the dyes and the fibre, anchoring the dyes wherever the alkali can permeate. Furthermore, 17.25 J of the energy is calculated to be saved for the dyeing of 60 g of fabric, which is very inspiring for large‐scale application. [ABSTRACT FROM AUTHOR]

In both the manufacturing and chemical industries, benzoquinone is a crucial chemical product. A perfect and economical method for making benzoquinone is the electrochemical oxidation of phenol, thanks to the traditional thermal catalytic oxidation of phenol process requires high cost, serious pollution and harsh reaction conditions. Here, a unique heterostructure electrocatalyst on nickel foam (NF) consisting of nickel sulfide and nickel oxide (Ni9S8‐Ni15O16/NF) was produced, and this catalyst exhibited a low overpotential (1.35 V vs. RHE) and prominent selectivity (99 %) for electrochemical phenol oxidation reaction (EOP). Ni9S8‐Ni15O16/NF is beneficial for lowering the reaction energy barrier and boosting reactivity in the EOP process according to density functional theory (DFT) calculations. Additionally, an alkali/acid hybrid flow cell was successfully established by connecting Ni9S8‐Ni15O16/NF and commercial RuIr/Ti in series to catalyze phenol oxidation in an alkaline medium and hydrogen evolution in an acid medium, respectively. A cell voltage of only 0.60 V was applied to produce a current density of 10 mA cm−2. Meanwhile, the system continued to operate at 0.90 V for 12 days, showing remarkable long‐term stability. The unique configuration of the acid‐base hybrid flow cell electrolyzer provides valuable guidance for the efficient and environmentally friendly electrooxidation of phenol to benzoquinone. [ABSTRACT FROM AUTHOR]

Background: Mitochondrial diseases (MDs) are systemic disorders that can affect multiple organs. Renal manifestations, including renal tubular acidosis, are common because kidneys are particularly vulnerable to energy deprivation. Treatment of MDs is often complex and electrolyte replacement can be difficult especially in pediatric patients, because large and repeated amounts of oral supplements are needed but are not well tolerated. Case presentation: We describe the case of a girl affected by Kearns-Sayre disease with severe renal tubular acidosis. The management of her metabolic acidosis was challenging because she showed persistent low levels of serum bicarbonates despite a progressive incrementation of oral bicarbonates. Furthermore, as a result to the ingestion of large amounts of alkali, the girl developed an aversion to oral supplementation. After positioning a percutaneous gastrostomy (PEG) and starting enteral administration of bicarbonates (with daily boluses and continuous nocturnal infusion), she finally obtained an adequate electrolyte control, with a significant increase in her quality of life. Conclusions: In MDs, the combination of nocturnal continuous enteral administration of alkali plus diurnal boluses may represent a valid solution to correct metabolic acidosis. It can also result in an improved patients' quality of life, particularly in pediatric settings, where compliance to oral therapy is often lacking due to the large and repeated amounts of unpalatable bicarbonates solutions required. [ABSTRACT FROM AUTHOR]

Herein, aluminosilicate (AS) glasses exhibit varying trends in Vickers hardness (H V), coefficient of thermal expansion, softening temperature (T s) and glass transition temperature owing to the mixed alkali effect. To elucidate the mechanism of the mixed alkali effect, the glass structure was characterised using multiple methods. Employing temperature-dependent topological constraint theory, the variations in H V and T s were investigated, and the constraint strengths of sodium (Na) and lithium (Li) in AS glasses were calculated. The findings indicated that an increase in alkali metal–ion content elevates the proportion of non-bridging oxygen, leading to a progressive decrease in constraint strength and the depolymerisation of the glass structure. For AS glasses with mixed alkali components, as the content of Li 2 O replacing Na 2 O increases, the constraint strength of the glass structure below the critical temperature (T c) gradually rises, while above T c , it undergoes unconventional changes. These alterations lead to non-linear variations in glass properties. [ABSTRACT FROM AUTHOR]

The electrochemical desalination technique is recognized as a promising solution to alleviate freshwater shortages, challenges yet persists in achieving optimal energy efficiency and cost‐effectiveness. Herein, a hybrid acid/alkali zinc air desalination battery (hAA‐ZADB) capable of concurrent desalination and high‐power density is reported. To improve cathodic efficiency and cost‐effectiveness, an electrocatalyst with dual atomic Fe–Mn sites on porous dodecahedral carbon (Mn‐Fe/p‐DC) is fabricated through a simple direct pyrolysis strategy for oxygen reduction reaction (ORR). The Mn–Fe/p‐DC‐900 electrocatalyst demonstrates exceptional electrocatalytic activity (E1/2 = 0.8 V in 0.5 m H2SO4) for ORR. This innovative hybrid acid/alkali cell design, coupled with advanced electrocatalysts, empowers the hAA‐ZADB system to achieve outstanding performance benchmarks with a high open circuit voltage of 2.22 V, an impressive power density of 375 mW cm−2, and notably elevated energy output of 106.9 kJ mol−1 even at a current density of 100 mA cm−2 during desalination. Distinguishing this work is its additional functionality, evident in a rapid salt removal rate of 3.64 mg cm−2 min−1 during desalination, achieving an impressive 88.67% removal of 0.6 M NaCl. This study highlights the promising potential of employing metallic air batteries for a self‐powered desalination technique applicable to specific scenarios. [ABSTRACT FROM AUTHOR]

Summary: The poor water solubility of flavonoids has always been a bottleneck restricting industrial production and application. The key problem of water‐solubility of flavonoids was solved by establishing an alkali substrate‐feeding engineering conversion platform using recombinant rhamnosidase. The results showed that the recombinant enzyme had α‐L‐rhamnosidase activity. Using this enzyme, four kinds of flavonoids such as hesperidin (HSD) were successfully hydrolyzed to products such as hesperetin 7‐O‐glucoside (HMG). Four key enzyme reaction conditions such as temperature, pH, feed rate and substrate specificity were investigated, and the optimum process parameters of the conversion platform were obtained. That was, under the conditions of temperature 50 °C, pH 6 and feeding speed 0.5 mL min−1, HSD conversion efficiency can reach 8.65 mg min−1. In addition, the changes in enzyme protein structure during basic feeding were elucidated by circular binary chromatography (CD) and fluorescence spectrum. The platform has the advantages of low cost, simple process, green environmental protection, high conversion rate and product purity. This method laid a solid foundation for the resource utilisation of flavonoid glycosides and industrial production. [ABSTRACT FROM AUTHOR]

Coal is still a great source of energy, but its high sulfur content causes environmental pollution and problems in its processing. This study used a method of combined oxidation and alkali leaching to desulfurize low-grade, high-sulfur Lakhra coal at different ranges of temperature, alkali concentration, leaching time, partial pressure of oxygen, and agitation speed. The optimum values for the leaching reaction were observed to be an alkali (NaOH) concentration of 0.8 mM, a leaching time of 1.5 h, an oxygen partial pressure of 150 psi, and an agitation speed of 800 rpm. The ash content of the coal initially increased at higher values of reaction time and temperature, and then became saturated at a certain peak. The raw coal was characterized for ultimate and proximate analysis, and the product was characterized for ash content and total sulfur content. [ABSTRACT FROM AUTHOR]

Below 5 °C, Portland cement (PC) experiences delayed hydration, slowing strength development, making it unsuitable for winter. Alkali-activated slag (AAS) emerges as a viable alternative with continuous hydration in low-temperature conditions. The effect of the activator nature on the performance of AAS cured at normal temperatures is well known, but further studies are required for low-temperature conditions. This study investigates the synergistic impact of activator modulus (1.2 and 1.5), alkali dosage (5, 7, and 9%), and PC substitution rates (0, 10, and 20%), on low-temperature cured AAS properties. Eighteen mixtures were prepared and cured at 2 °C. Compression and ultrasonic pulse velocity tests were conducted after 7, 28, and 90 days. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy analyses were performed to examine the microstructure of the samples. Elevating alkali dosage enhanced early age strength but resulted in a drop in 90-day strength. Simultaneous increases in modulus and PC substitution rate reduced strength due to shrinkage-induced crack formation. Optimal mixture design options included using 10% PC in the 1.2 modulus and omitting PC when the 1.5 modulus was selected. Despite low temperatures, the use of PC significantly accelerated the setting time. Altering modulus and alkali dosage caused a considerable change in the intensity of the peaks in the FTIR spectrum. The findings indicate that AAS shows promise when adjusting the mixture design for temperatures below 5 °C, which are unfavorable for the hydration of PC. [ABSTRACT FROM AUTHOR]

This present work explored the possible use of sandbox seed (Hura crepitans) shell (SSS) waste as a feedstock for synthesizing green solid alkali biocatalyst in the microwave-aided sandbox oil (SBO) transesterification to obtain SBO biodiesel (SBOB). The solid catalyst was produced using a calcination method by burning raw SSS in the open air to obtain ash heated for 3 h in a furnace at 500 °C. The calcined sandbox shell ash (CSSA) produced was characterized using standard techniques to establish its catalytic potency. Also, a model was developed to simulate the process and examine the interactive effect of process input variables on SBOB yield using the Taguchi approach. The CSSA characterization showed it composed of K (44.99 %), Ca (1.54 %), and Mg (1.87 %) with crystalline compounds of K and Mg. The physisorption results gave a mean pore size of 18.142 nm and a surface area of 6.1125 m2/g. The best combination of the input variables determined for the process is a heating power of 450 W, methanol:SBO of 8:1, time of 1.5 min, and CSSA loading of 2 wt% with an optimum SBOB yield of 98.27 wt%. The SBOB produced met standard specifications for biodiesel. Microwave application to the SBO transesterification aided in rapidly completing the reaction. The study concluded that sandbox seeds and their shells are promising feedstock for cheap and sustainable biodiesel production. [Display omitted] • Novel biocatalyst from Sandbox shell wastes was synthesized and characterized. • Sandbox oil biodiesel was produced via transesterification with the biocatalyst. • The transesterification process was modeled and optimized by Taguchi method. • 98.27 wt% biodiesel yield was achieved using the optimum values obtained. • Sandbox oil biodiesel produced satisfied the standard specifications. [ABSTRACT FROM AUTHOR]

An improved hydrothermal method was proposed to rapidly synthesize zeolite W from alkali fusion‐activated K‐feldspar. The effects of m (KOH)/m (K‐feldspar), n (SiO2)/n (Al2O3), n (H2O)/n (SiO2), crystallization time, and crystallization temperature on the synthesis of the zeolite W were investigated. The optimal synthesis conditions were m (KOH)/m (K‐feldspar) ratio of 1.5:1, the activation time of 2 h, and the activation temperature of 500°C, n (H2O)/n (SiO2) ratios of 42, n (K2O)/n (SiO2) of 0.90, n (SiO2)/n (Al2O3) of 5, crystallization time of 6 h, and crystallization temperature of 150°C. The mechanism for rapid synthesis of zeolite W was illustrated. In this process, Na2SiO3·9H2O and Al2(SO4)3·18H2O were first dissolved rapidly in the synthesis system to form an amorphous gel, which contributes to the accelerated crystallization process. Compared with the state‐of‐the‐art synthesis method, this method remarkably decreases the water content to be added in the synthesis process and crystallization time, avoids the pre‐preparation process of the xerogel, and enhances the utilization rate of K‐feldspar. This work provides an industrial‐friendly synthesis process of zeolite W and could realize the highly efficient utilization of K‐feldspar. [ABSTRACT FROM AUTHOR]

Purpose: The production of commodities from renewable organic material has gained enormous interest due to the rising public understanding of conscious development. Natural fibers are accessible in environment, and their parameters depend on their physical traits and chemically engineered makeup. Grewia optiva (GO) comes under the category of bast fibers, also known as Bhimal. This study aims to realize the consequences of alkali treatment on the characterization of natural fibers, their developed yarn and then the woven mat. Design/methodology/approach: Raw fiber was treated with 20% alkali solution. After treatment, it was evaluated for changes in the general laboratory system. This treatment is known as mercerization, through which the parameters of cellulose fibers can be enhanced. After this process, the content of cellulose increases due to the removal of the hydroxyl group. The removal of microfibrils, hemicellulose and the introduction of hydrogen bonds increase the interactive capacity of fiber. The job was divided into different sections, including acquiring fiber, developing yarn and creating a mat. Findings: The quality of the surface of the fiber was enhanced after the treatment. Its diameter was reduced to 54.72 microns. In the developed woven mat, it was densified using water treatment and attained grams per square meter (GSM) of 389.7. Originality/value: The usage of mercerization softens the fiber to twist into yarn, which is finally woven into a mat. Treatment of fabric or mat makes it denser to impart better strength. A woven mat of natural fibers provides maximum strength to the composites. [ABSTRACT FROM AUTHOR]

The alkali–silica reaction significantly impacts the durability of reinforced concrete structures. This paper aims to investigate the structural expansion properties of reinforced concrete beams under different partial alkali–silica reactions. Alkali–silica reaction tests were conducted on four reinforced concrete beams, focusing on immersion depth and NaOH solution position as key parameters. Subsequently, the spatial and temporal distribution characteristics of the beam expansion rate were analyzed. Results indicate notable variations in the expansion's initiation, rate, and final magnitude at different measurement points on the concrete beam, depending on the soaking positions and depths used. The expansion rate was higher in areas directly immersed in the NaOH solution, decreasing near the reinforcement regions. However, strain distribution, along with beam height, satisfied plane-section assumption in the reinforced beam section. Finally, a regional expansion index was established to quantitatively assess the non-uniform damage by alkali aggregates in beams, and the uniaxial restraint mechanism in reinforced concrete structures was also described. [ABSTRACT FROM AUTHOR]

We explore light storage in antirelaxation-coated and buffer-gas-filled alkali vapor cells, employing electromagnetically induced transparency (EIT) in warm rubidium vapor. We conduct a comparative study of light storage performance under identical experimental conditions for these two cell types. Using a buffer-gas-filled cell resulted in approximately a tenfold improvement in memory efficiency and storage time compared to antirelaxation-coated cells. Moreover, we demonstrate that memory efficiency can be further enhanced by choosing a near-resonant EIT Λ -scheme over a resonant one. Our findings provide valuable insights for optimizing light storage, thereby contributing to the development of field-deployable quantum memories. [ABSTRACT FROM AUTHOR]

The term 'green ammonia' can be misleading. For fertilisers to merit a green label, the industry must adopt a planetary boundaries framework that includes reducing carbon emissions and circular management of nutrients. It should seek to achieve net reductions in reactive nitrogen and phosphorus fluxes to terrestrial and marine ecosystems. [ABSTRACT FROM AUTHOR]

Alkali pretreatment of fibers is an efficient technique to enhance fiber/matrix bonding in natural fiber composites. This study investigates if the addition of sodium dodecyl sulfate (SDS) surfactant increases the efficacy of alkali treatment of hemp fibers. SDS concentrations ranging between 2 and 10% wt/wt were used with a constant (10% wt/wt) NaOH concentration. Fiber surfaces were observed with scanning electron microscopy (SEM). Fiber surfaces were cleaner when SDS was used compared with alkali treatment with no SDS added indicating the elimination of substances such as lignin, waxes, hemicelluloses, and pectin. Fourier‐transform infrared spectroscopy and TGA studies also confirmed the removal of these substituents. Mechanical performance of the composites was evaluated via static and dynamic tests. The tensile strength and modulus improved 24.9% and 13.6% respectively with the addition of 10 wt% SDS. The flexural strength and modulus also showed an improvement of 22.4% and 26.3% respectively when 10 wt% SDS was added to alkali solution. Dynamic mechanical tests showed that the storage and loss modulus of the composites increase with SDS/alkali treatment. Results indicated that the use of SDS in alkali treatment notably improves the composite performance which is attributable to more efficient elimination of noncellulosic constituents from fiber structure. Highlights: Sodium dodecyl sulfate (SDS) improves the efficacy of NaOH treatment of hemp.Removal of noncellulosic substances from fibers was facilitated by SDS.Ultrasound/SDS assisted alkalization of fibers improved composite properties. [ABSTRACT FROM AUTHOR]

Rechargeable Zn–air batteries (ZABs) are considered highly competitive technologies for meeting the energy demands of the next generation, whether for energy storage or portable power. However, their practical application is hindered by critical challenges such as low voltage, CO2 poisoning at the cathode, low power density, and poor charging efficiency Herein, a rechargeable hybrid alkali/acid Zn–air battery (h‐RZAB) that effectively separates the discharge process in an acidic environment from the charging process in an alkaline environment, utilizing oxygen reduction reaction (ORR) and glycerol oxidation reaction (GOR) respectively is reported. Compared to previously reported ZABs, this proof‐of‐concept device demonstrates impressive performance, exhibiting a high power density of 562.7 mW cm−2 and a high operating voltage during discharging. Moreover, the battery requires a significantly reduced charging voltage due to the concurrent utilization of biomass‐derived glycerol, resulting in practical and cost‐effective advantages. The decoupled system offers great flexibility for intermittently generated renewable power sources and presents cost advantages over traditional ZABs. As a result, this technology holds significant promise in opening avenues for the future development of renewable energy‐compatible electrochemical devices. [ABSTRACT FROM AUTHOR]

The mining industry generates vast quantities of mine tailings on an annual basis. However, due to their limited economic value, a significant portion of these tailings are deposited close to mining sites, often underwater. The principal environmental apprehensions associated with mine tailings revolve around their elevated levels of heavy metals and sulfidic minerals. The oxidation of these sulfidic minerals can lead to the formation of acid mine drainage, which in turn releases heavy metals into nearby water systems. The effective management of tailing dams requires substantial financial investments for their construction and meticulous control. Consequently, a pressing need exists for stable, sustainable, and economically viable management approaches. One promising method for addressing mine tailings is through alkali activation, a technique that serves as a stabilization process. This approach yields robust, concrete-like structures by utilizing raw materials abundant in aluminum and silicon, which conveniently constitute the primary components of mining residues. This comprehensive review outlines the research on utilizing alkali activation for mine tailings. It delves into the reactivity and chemical attributes of diverse minerals. Numerous mine tailings exhibit an inadequate level of reactivity under alkaline conditions, so various pre-treatment methodologies and their impacts on mineralogy are meticulously explored. [ABSTRACT FROM AUTHOR]

Recently, the ambient drying method for the preparation of xerogels has attracted great attention due to its low cost and high drying efficiency. However, the strong capillary forces existing during ambient drying cause severe shrinkage or even collapse of the aerogels (called xerogels). Although chemical crosslinking or displacement of water by organic solvents have been tried to solve the problem, extensive usage of chemicals and time-consuming displacement processes seem to be environmentally unfriendly and complex. Herein, we reported a green and efficient method for the preparation of a lignocellulosic xerogel. The xerogel was fabricated by alkali freezing of unbleached eucalyptus fibers followed by water washing and ambient drying. The alkali freezing promoted fiber swelling and enhanced the hydrogen bonds among the fibers, resulting in the gelation of lignocellulosic fibers. In particular, the residual lignin in the fibers reduced the capillary force during the drying process. The resulting lignocellulosic xerogel achieved a low shrinkage rate (27.50%), low density (0.039 g cm−3 ), high porosity (97.57%), and excellent mechanical strength (782.23 kPa) as well as environmental stability, and low thermal conductivity (44.76 mW m−1 K−1 ). Similarly structured xerogels could be generated using recycled NaOH solution. This technique was suitable for production using various kinds of plant fibers, which shows its great scalable production prospects. [ABSTRACT FROM AUTHOR]

The accumulation of municipal solid waste incineration bottom ash (MSWI-BA) not only occupies land, but also leads to severe environmental pollution. In order to improve the utilization of MSWI-BA and reduce carbon emissions, the effect of alkali content on alkali-activated slag (AAS) paste containing 12% MSWI-BA under high-temperature exposure was studied. The alkali contents, i.e., the mass of Na2O in the water glass, were 2%–6% of the total mass of the precursors. The weight loss, thermal shrinkage, and strength of AAS were investigated. The results show that at the same heat treatment temperature, as the alkali content increases, the flexural and compressive strengths of AAS increase and then decrease, reaching the maximum at AAS with 4% alkali content (NS4). As the alkali content increases from 2% to 4%, the higher OH− concentration reduces the Ca dissolution of portlandite in MSWI-BA, resulting in a lower increase in Ca concentration than Si concentration. This leads to a decrease in Ca/Si and an increase in Al/Si of C─ A─ S─ H, which is beneficial for improving the structural stability of C─ S─ H after high temperature. When the alkaline content increases from 4% to 6%, excessive matrix shrinkage leads to an increase in microcracks. It was found that NS4 has the best high-temperature resistance and has good application prospects in engineering. [ABSTRACT FROM AUTHOR]

In order to study the frost resistance of alkali activated concrete (AAC), 15 AAC cube specimens and 15 cylindrical specimens were designed and manufactured. The frost thawing cycle test and mechanical performance test were used to study the frost resistance of AAC. The results showed that after freeze–thaw cycles, small pores appeared on the surface of the specimen, and the surface roughness increased, resulting in a darker appearance. As the number of freeze–thaw cycles increases, the highest mass loss rate of AAC reaches 1.88%. The cube compressive strength and axial compressive strength of AAC first increase and then decrease, while the elastic modulus gradually decreases. After 50 freeze–thaw cycles, the compressive strength of the specimen was greater than that of the normal temperature specimen. When the freeze–thaw cycles reached 200, the elastic modulus of the specimen degraded by 9.7%, the compressive strength decreased by 18.6%, and the axial compressive strength decreased by 31.2%. Based on the experimental results, a method for calculating the residual strength of AAC after freeze–thaw cycles and key parameters of the freeze–thaw damage constitutive equation were proposed. [ABSTRACT FROM AUTHOR]

Background: A systematic review and meta-analysis have been conducted to evaluate the efficacy of alkalinization for COVID-19 patients based on current evidence to determine the impact of alkalinization on COVID-19 outcomes. Methods: We searched MEDLINE (Pubmed), Web of Science, Cochrane Library, and Clinicaltrials.gov for studies evaluating the efficacy of alkalinization up to 30 April 2023. Based on the PRISMA 2020 statement criteria a systematic review and meta-analysis of studies were performed. Results: The results of our meta-analysis showed a significant reduction in mortality rate in the alkalinization group compared to controls (RR 0.73, 95% CI: 0.56-0.95; I2 = 0%). However, our subgroup analysis showed no significant improvement in RCT-only studies (RR 0.78, 95% CI: 0.59-1.05; I2 = 0%), the recovery rate was significantly higher in the alkalinization group (RR 2.13, 95% CI: 1.39-3.26; I2 = 0%), duration of recovery also has improved in alkalinization group (SMD 0.76, 95% CI: 0.33-1.18; I2 = 0%). The results of our meta-analysis showed a significant reduction in the duration of hospitalization in the alkalinization group compared to controls with very low certainty of evidence (SMD −0.66, 95% CI: −0.97 to −0.35; I2 = 36%). Conclusion: With low certainty of evidence, alkalinization (by sodium bicarbonate) can be an efficient and safe adjuvant treatment for COVID-19 patients. Future randomized controlled trials are needed to strengthen the available evidence. [ABSTRACT FROM AUTHOR]

The effect of TiO2 on the phase transformation and microstructure evolution of Ti-containing melting slag in the alkali fusion process has been investigated. The results showed that, after alkali fusion roasting, the original phase of Ti-containing melting slag was completely decomposed by molten NaOH, and that the alkali fusion slag mainly included Na2TiO3 and NaMO2 (M = Ti, Mg). With increasing TiO2 content, NaMO2 and Na2TiO3 converted to each other, and the content of sodium magnesium silicate also changed with the "in and out" of Mg. The contents of NaAlO2 and silicates were not significantly affected by the TiO2 content, while the microstructure of the melting slag corroded by molten NaOH changed greatly. With increasing TiO2 content, the microstructure of the alkali fusion slag transformed from an uneven grain size to a uniform grain size, and ultimately a compact structure. [ABSTRACT FROM AUTHOR]

At temperatures above about 600 °C, alkali feldspar forms a continuous solid solution between the Na and K end members. Towards lower temperatures a miscibility gap opens, and alkali feldspar of intermediate composition exsolves, forming an intergrowth of relatively more Na-rich and K-rich lamellae. During exsolution, the crystal structure usually remains coherent across the lamellar interfaces, a feature that may be preserved over geological times. Due to the compositional dependence of the lattice parameters, coherent intergrowth requires that the lamellae are elastically strained. The associated elastic strain energy counteracts exsolution, and the solvus delimiting the misciblity gap for coherent intergrowth lies below the solvus for strain free phase equilibria. To determine the coherent solvus, homogeneous gem quality alkali feldspar of intermediate composition was annealed at conditions falling into the two-phase region of the phase diagram. Thereby a coherent intergrowth of approximately 10–20 nanometers wide lamellae was produced. Lamellar compositions were determined with atom probe tomography defining points on the coherent solvus. In parallel, the coherent solvus was calculated using a thermodynamic mixing model calibrated on the same alkali feldspar as used for the exsolution experiments and accounting for the elastic strain energy associated with coherent lamellar intergrwoth. The experimentally determined and the calculated coherent solvus are in excellent agreement indicating that phase equilibria in coherent lamellar intergrowth of alkali feldspar are adequately described, providing a sound basis for the interpretation of phase relations in coherently exsolved alkali feldspar. [ABSTRACT FROM AUTHOR]

Ultra-flat, ultra-thin alkali antimonide photocathodes with high crystallinity can exhibit high quantum efficiency and low mean transverse energy of outgoing electrons, which are essential requirements for a variety of applications for photocathode materials. Here, we investigate the growth of Cs3Sb on graphene-coated 4H–SiC (Gr/4H–SiC), 3C–SiC, and Si3N4 substrates. Sb is deposited using pulsed laser deposition, while Cs is deposited thermally and simultaneously. We demonstrate, employing x-ray analysis and quantum efficiency measurements, that this growth method yields atomically smooth Cs3Sb photocathodes with a high quantum efficiency (>10%), even in the ultra-thin limit (<30 nm). For the Si3N4 substrate, film growth is shown to be polycrystalline, while films grown on Gr/4H–SiC show a high degree of ordering with signs of epitaxy. [ABSTRACT FROM AUTHOR]