Consecutive Experiments Research Articles

Preparation of N, S co-doped carbon nanotubes composites by coal pyrolysis for the CO2 capture

In this paper, nitrogen and sulfur co-doped carbon nanotubes composites were prepared by coal pyrolysis with the aim of applying them to carbon dioxide adsorption. Compared with previous carbon nanotubes modification methods, this study increased the specific surface area, microporosity and the number of adsorption sites of the materials through structural modification and surface modification, thus improving the adsorption capacity. Notably, secondary KOH activation modification was employed to increase the N and S elemental content in the adsorbent. Without leading to the loss of specific surface area, the specific surface area after modification was increased by 29% to 1875 m2/g, and the N content in the adsorbent could be reasonably regulated. The IAST calculations revealed that the prepared adsorbent had a high selectivity for CO2/N2 in binary gas mixtures, which is of practical significance for the treatment of flue gas streams. In addition, the isocratic heat of adsorption of the adsorbent was calculated to be less than 40kJ/mol using the Clasius-Clapeyron equation, which indicates that the adsorbent is easy to desorb and can be used several times. After five consecutive CO2 adsorption experiments, the adsorbent retained 98.22% of its CO2 adsorption capacity. Overall, this study not only provides a new idea for the high value-added utilization of low-rank bituminous coal. It also provides an important reference for the large-scale doping of N and S elements in coal-based carbon materials, which has certain theoretical and applied values.

Enhancement of the Plant-Accessible Phosphate Fraction in Sewage Sludge Ashes by Na+ or K+ Addition Prior to Combustion.

With the aim of transforming sewage sludge into a P-fertiliser material in a single combustion step, the chemical processes underlying sewage sludge combustion were analysed using powder X-ray diffraction (P-XRD), infrared spectroscopy (IR), thermogravimetric (TGA) as well as elemental analyses (EA). In addition to the combustion of sewage sludge on its own ("mono-combustion"), additions of different additives prior to the combustion step were also carried out. Based on the very positive effects of the additives sodium and potassium carbonate on the obtained ashes concerning their phosphate solubilities in neutral ammonium citrate (NAC) solution, sewage sludge combustions after additions of Na2CO3 or K2CO3 were investigated in detail. We found that these additions altered the main phosphate-containing product found in the ashes from whitlockite (Ca9(Mg,Fe)(PO3OH)(PO4)6), a hardly plant-accessible species, to other phosphate containing compounds such as buchwaldite (CaNaPO4), which is known for a long time as a very good P‑source for plants. Consecutive greenhouse experiments with maize (Zea mays L.) as test plant confirmed the results of the chemical analyses and demonstrated that Na- or K-ashes obtained from a "co-combustion" of sewage sludge mixed with alkali carbonates exhibit relative P-fertilising efficiencies of up to ~80% in comparison to commercial superphosphate.

Simultaneous dehalogenation and oxidation of dichloroacetamide by Cu-modified CoFe-LDH in three-dimensional continuous flow aerated electrocatalytic reactor

Searching for catalysts and degradation systems for synchronous dehalogenation and oxidation of haloacetamides (HAcAms) is pressing. In this study, a novel three-dimensional continuous flow aerated electrocatalytic reactor (3D CFAER) system, which employed Cu-modified CoFe layered double hydroxides (CoFe-LDH) composite/activated carbon as a catalytic particle electrode for the degradation of dichloroacetamide (DCAcAm) was constructed. Under the experiment’s optimal operating parameters, the maximum degradation rate of DCAcAm reached 91.7 %. The superior performance for the degradation of DCAcAm was due to the enhanced electron transfer induced by the modification of Cu in CoFe-LDH. Moreover, Density Functional Theory (DFT) calculations indicated that Cu doping improved the ability of LDH to dissociate water, thereby enhancing its electrocatalytic performance. Scavenger experiments and Electron Paramagnetic Resonance (EPR) results revealed that •OH, O2•– and electrochemical direct dehalogenation were responsible for DCAcAm removal. Additionally, the electrocatalytic stability of the electrode was tested upon repeated use with DCAcAm degradation remaining as high as 81.7 % after five consecutive experiments. More importantly, in 3D CFAER, electrocatalytic treatment lasting 90 min reduced the TOC and COD of the actual chlorine disinfection wastewater by 64.1 % and 74.9 %, respectively. This study provides new theoretical basis and technical support for control of HAcAms.

Construction and degradation mechanism of the magnetic CoFe1.95Y0.05O4/Ag/g-C3N4 Z-scheme heterojunction for enhanced photocatalytic activity

In this study, a Z-scheme heterojunction CoFe1.95Y0.05O4/Ag/g-C3N4 (CFYO/ACN) magnetic nanocomposite was prepared by hydrothermal synthesis. The composite was characterised and analysed using different characterisation tools and its photocatalytic degradation activity towards methylene blue (MB) was investigated. The results showed that the CFYO/ACN photocatalyst compared to CoFe1.95Y0.05O4 (CFYO) and Ag/g-C3N4 (ACN), the composite CFYO/ACN had the highest degradation efficiency of MB, which was up to 97% within 120 min, which was 1.26 and 1.09 times higher than that of ACN and CFYO, respectively. The enhancement of the catalytic performance of CFYO/ACN was attributed to the fact that the heterogeneous junction formation effectively inhibited the complexation of photogenerated carriers. In addition, five consecutive cyclic degradation experiments showed that CFYO/ACN exhibited efficient photocatalytic degradation, stable crystal structure, and easy recycling in the photodegradation process. Finally, the capture experiments confirmed that superoxide radicals () and hydroxyl radicals (·OH) play a major role in the degradation process. This study provides an effective strategy for the construction of efficient photocatalysts.

Construction of visible-light-induced Fe2O3/g-C3N4 nanocomposites for the enhanced degradation of organic dyes: Optimization of operative parameters

This research aims to develop the highly promising Fe2O3/g-C3N4 photocatalyst through hydrothermal techniques to cope with the elevated amounts of bromophenol blue (BPB) dye in wastewater. The morphological studies were carried out by SEM analysis, while the crystallinity, structural behavior, and oxidation states of the prepared materials were determined by XRD, FTIR, and XPS analysis. The hydrodynamic size, surface area, and magnetic characteristics of the constructed materials were assessed through DLS, BET, and VSM analysis. The effectivity of the synthesized Fe2O3 and Fe2O3/g-C3N4-30 photocatalysts was appraised by the abatement of BPB under visible light radiation for 48 min. The results have shown an excellent degradation efficacy of Fe2O3/g-C3N4-30 photocatalyst with 98.39 % of BPB removal and a rate constant of 0.0757 min−1, which was much higher than Fe2O3 photocatalyst with 79.64 % of removal and a rate constant of 0.0335 min−1 under optimum conditions. The enhancement in degradation efficiency of the Fe2O3/g-C3N4-30 was due to the large surface area of Fe2O3/g-C3N4-30 (106.94 m2/g) as a result of g-C3N4 inclusion in the material, while the pure Fe2O3 unveiled a surface area of 89.67 m2/g. The impact of different reaction parameters on BPB degradation was also investigated, while the contribution of free radicals was corroborated through radical trapping experiments. The Fe2O3/g-C3N4-30 exhibited tremendous stability for repeated applications, with a loss of 8.03 % in efficiency after five consecutive experiments because of its easy magnetic separation. The experimental results have shown that synthesized Fe2O3/g-C3N4-30 photocatalysts could be used for the effective degradation of BPB from wastewater.

Biocontrol potential of Bacillus subtilis CRB7 for the management of root-knot nematode in tomato under protected cultivation

In the present study, biocontrol potential of Bacillus subtilis CRB7 was evaluated to counter root-knot nematode infestation in tomato grown under protected cultivation. Under pot conditions, gall formation on roots was reduced when B. subtilis CRB7 applied at 1.25, 2.5 and 5 g plant−1. Nursery drench with B. subtilis CRB7 at 5, 10 and 15 g m−2 significantly reduced gall formation on roots (37.0 to 85.8%). Further, application of B. subtilis CRB7 as nursery drench at 15 g m−2, soil drench at 0.5% at 30 day’s interval and soil application of enriched vermicompost (5 kg 2 tonnes−1 of vermicompost ha−1) significantly reduced gall formation on roots (58.3% and 54.2%) and enhanced yield (29.8% and 15.4%) in two consecutive protected field experiments, respectively. Given its potent efficacy, B. subtilis CRB7 emerges as a promising component for the management of root-knot nematode in tomato grown under protected cultivation.

Element release from lead crystal ware and metallic hip flasks

The release of 21 elemental ions from lead crystal ware and metallic hip flasks into different food simulants as well as alcoholic beverages was investigated in this study. For this purpose, an ICP-MS method including a sample pre-treatment based on microwave-assisted digestion was developed and validated. Elemental ion release from lead crystal glasses into artificial tap water, 0.5% citric acid solution and white wine, respectively, was only analysed for Pb. Within 24 h, Pb release from crystal glass was shown to increase with time. To account for repeated use, at least three consecutive release experiments were performed, which showed – with one remarkable exception – constant or decreasing levels of element ion release. However, after four months resting period, Pb release from crystal glass was higher than before. In contrast, all 21 elemental ions were detected to be released from the hip flasks into 0.5% citric acid solution, apple liqueur and herb liqueur, respectively. Release of Cd, Cr, Ni, As, TI, Sn and most prominently Pb from hip flasks was in the range of and above the respective release limit (SRL) as set by the Council of Europe (CoE). When focussing on the third repetition, only one out of six hip flasks met the suggested SRL for all determined elements in all test solutions. This demonstrates both, that the SRLs of the CoE can be met and that producers of hip flasks may have to review their manufacturing processes.

Mangrove mapping in China using Gaussian mixture model with a novel mangrove index (SSMI) derived from optical and SAR imagery

As an important shoreline vegetation and highly productive ecosystem, mangroves play an essential role in the protection of coastlines and ecological diversity. Accurate mapping of the spatial distribution of mangroves is crucial for the protection and restoration of mangrove ecosystems. Supervised classification methods rely on large sample sets and complex classifiers and traditional thresholding methods that require empirical thresholds, given the problems that limit the feasibility and stability of existing mangrove identification and mapping methods on large scales. Thus, this paper develops a novel mangrove index (spectral and SAR mangrove index, SSMI) and Gaussian mixture model (GMM) mangrove mapping method, which does not require training samples and can automatically and accurately map mangrove boundaries by utilizing only single-scene Sentinel-1 and single-scene Sentinel-2 images from the same time period. The SSMI capitalizes on the fact that mangroves are differentiated from other land cover types in terms of optical characteristics (greenness and moisture) and backscattering coefficients of SAR images and ultimately highlights mangrove forest information through the product of three expressions (f(S) = red egde/SWIR1, f(B) = 1/(1 + e-VH), f(W)=(NIR-SWIR1)/(NIR+SWIR1)). The proposed SSMI was tested in six typical mangrove distribution areas in China where climatic conditions and mangrove species vary widely. The results indicated that the SSMI was more capable of mapping mangrove forests than the other mangrove indices (CMRI, NDMI, MVI, and MI), with overall accuracys (OA) higher than 0.90 and F1 scores as high as 0.93 for the other five areas except for the Maowei Gulf (S5). Moreover, the mangrove maps generated by the SSMI were highly consistent with the reference maps (HGMF_2020、LASAC_2018 and IMMA). In addition, the SSMI achieves stable performance, as shown by the mapping results of the other two classification methods (K-means and Otsu’s algorithm). Mangrove mapping in six typical mangrove distribution areas in China for five consecutive years (2019–2023) and experiments in three Southeast Asian countries with major mangrove distributions (Thailand, Vietnam, and Indonesia) demonstrated that the SSMIs constructed in this paper are highly stable across time and space. The SSMI proposed in this paper does not require reference samples or predefined parameters; thus, it has great flexibility and applicability in mapping mangroves on a large scale, especially in cloudy areas.

A different application of the Aliquat® 336 loaded poly(vinylidene fluoride-co-hexafluoropropylene) based electrospun nanofibers disks for the preconcentration followed by flame atomic absorption spectrometry detection of low-level Bi(III)

It is the first report on the potential of electrospun nanofiber disks inserted in a filtration apparatus as a preconcentration strategy for the analysis of low-level metals. The nanofibers included 60 wt% of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and 40 wt% of ionic liquid Aliquat® 336. The electrospinning process was done by applying a voltage of 16 kV, an injection rate of 1 mL h−1, and 10 cm distance of the needle tip location from the drum collector. A circular piece of the prepared nanofiber disks was placed in a filtration apparatus, and 200 mL solution containing 1 mg of Bi(III) adjusted to 0.5 mol/L of hydrochloric acid was transmitted from inside the nanofiber disk by controlling the flowrate (3.3 mL s−1). The adsorbed Bi(III) was eluted by 10 mL of 0.2 mol/L solution of ethylendiaminetetraacetic acid and ammonium hydroxide mixture, and then was analyzed by flame atomic absorption spectrometry. The introduced technique (nanofiber disks-based solid phase extraction) can be used in the bismuth concentration range of 4–2000 µg/L, with a limit of detection 1.2 µg/L. The determined inter- and intra-day relative standard deviations (3 days and n = 7) for a solution of 100 µg/L of bismuth were 1.1 % and 2.4 %, respectively. The method offers a preconcentration factor of 200-fold. The fabricated nanofiber disks were used at least in 7 consecutive preconcentration experiments. The proposed method was selective towards Bi(III) and can be used satisfactory for its determination in real samples.

The microbiome of bioreactors containing mass-cultivated marine diatoms for industrial carbon capture and utilization

Marine microalgae are a promising innovation platform for carbon capture and utilization (CCU) biotechnologies to mitigate industrial greenhouse gas emissions. However, industrial-scale cultivation of algal mono-cultures is challenging and often unscalable. Non-axenic microalgae in large semi-open photobioreactors lead to the co-cultivation of diverse microbial communities. There is limited knowledge about the “bioreactor ecology” involving microalgae interacting with the microbiome and its subsequent impact on process stability and productivity. In this study, we describe the semi-continuous industrial mass cultivation of the cold-adapted marine diatom, Porosira glacialis UiT201, by investigating the prokaryotic and microeukaryotic (phytoplankton and heterotrophic protist) communities. Data were collected in two consecutive time series experiments, representing the initiation and operation of an industrial-scale CCU photobioreactor (300,000 L). The first experiment experienced a culture “crash” of the focal strain after 39 days, while the second culture remained stable and “healthy” for 60 days. The results highlight that this mass cultivation system represents a unique industrial marine microbial ecosystem. The succession of the prokaryotic community was primarily driven by species replacement, indicating turnover due to selective bioreactor conditions and/or biological interactions. Nonetheless, the bioreactor consistently harbors a recurring and abundant core microbiome, suggesting that the closely associated bacterial community is influenced by microalgae-specific properties and can endure a dynamic and variable environment. The observed culture collapse of P. glacialis coincided with changes in the core microbiome structure and different environmental growth conditions compared to the stable and “healthy” experiment. These findings imply that cohabiting microbial taxa within industrial microalgae cultivation likely play a critical role in stabilizing the conversion of industrial CO2 into marine biomass, and changes in community structure serve as an indicator of process stability.

Behavioral Transition Path and Pivotal Nodes Regulating Attack in Initial Encounters between Unfamiliar Pigs.

This study leverages the inherent curiosity of pigs and their competitive nature among conspecifics to explore behavioral transition paths and critical nodes that govern aggression during initial encounters between unfamiliar individuals. Two consecutive experiments were designed to investigate these dynamics under controlled conditions. In Experiment 1, unfamiliar pigs engaged in one-on-one fights with quick retreats, displaying a simple behavioral sequence of looking followed by attacking. In Experiment 2, the addition of new pigs to resident groups resulted in a more complex and structured behavioral sequence. Resident pigs exhibited a 'four-step' exploratory behavior pattern: looking, sniffing, touching, and attacking. Further analysis revealed distinct exploratory pathways. In Experiment 1, only short behavioral paths were observed, while Experiment 2 revealed both long and short paths. Specifically, Experiment 2 uncovered seven types of behavioral transition paths, four of which were long and three short, highlighting different combinations of the basic behaviors. The transition paths involving aggression were more varied in Experiment 2 compared to Experiment 1. Overall, the 15 most frequent and obvious behavioral transition paths were identified across both experiments. Eight types of paths were categorized based on the transitions between the basic behaviors. These findings enhance our understanding of the behavioral dynamics in unfamiliar pig encounters, emphasizing the complexity of social interactions and the conditions under which aggression occurs.

Sex-specific effects of low-dose of acetamiprid on corticosterone levels but not on oxidative stress in House sparrows

Neonicotinoid insecticides are widely used in agriculture and have been linked to various detrimental physiological effects on wild birds. Despite this, the impact of acetamiprid – a less studied member of the neonicotinoid family – on the hypothalamic-pituitary-adrenal axis responsible for the hormonal regulation of the response to stress has rarely been examined in birds. In our study, we explored the effects of acetamiprid on feather levels of corticosterone, the major end product of the HPA, and blood oxidative status of House sparrows (Passer domesticus), following the ingestion of a low, field-realistic dose during two consecutive experiments in 2015 and 2016. We involved 112 birds in each experiment – 56 males and 56 females – that were administered a placebo or a dose of acetamiprid equivalent to 0.5% of the LD50 of the Zebra finch over the entire duration of the experiments, which lasted approximately three weeks. We measured corticosterone concentrations in feathers grown during an acclimation phase before ingestion and in newly grown feather after the experiment and assessed three oxidative stress markers in the blood. We found no impact of acetamiprid on oxidative stress markers. However, in 2015, male sparrows that ingested acetamiprid exhibited higher corticosterone levels in their feathers compared to those that received a placebo. No such difference was found in females. Interestingly, this effect was not observed in year 2016, which was characterised by less stressful conditions for the birds. These findings offer the first evidence of a potential effect of acetamiprid on corticosterone levels in a songbird, suggesting that ingesting this compound at very low dose may alter the endocrine physiology of the response to stress.

Strategically engineered multifunctional graphene oxide hybrid nanomaterials for efficient catalytic degradation and emerging contaminants treatment

The use of functional textiles is growing in all fields of science and technology. Surface functionalization is mainly used to impart conventional textiles with new functionalities and improved performances. In the present study, a cobalt ferrite nanoparticle/graphene oxide (CoFe2O4/GO) coated polyethylene terephthalate (PET) fabric with excellent catalytic and antibacterial properties, has been successfully developed. The PET-coated CoFe2O4/GO samples, ranging from 1 % to 5 % wt. were obtained using a simple dip-coating method in CoFeO/GO solution (1 mg/mL), and were investigated through several physiochemical characterization techniques. CoFe2O4/GO and PET fabric have been shown to establish an interfacial connection by Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) results showed that CoFe2O4/GO coating did not affect the PET crystallinity and that CoFe2O4/GO hybrid was incorporated in the PET samples, which was proved as well by the morphological study through Scanning electron microscopy (SEM). Furthermore, thermogravimetric characterisation (TGA) verified that the coating does not change or impair the quality of the fibre and that the PET@CoFe2O4/GO as made is thermally stable. Tensile strength tests demonstrated that coated fabrics exhibited outstanding mechanical properties in comparison with pristine PET. Moreover, the coated PET@CoFe2O4/GO fabric was used as a model catalytic system for peroxymonosulfate (PMS) activation in the rhodamine B (RhB) degradation reaction. Total Organic Carbon (TOC) measurements showed that TOC removal reached 89.82 % in only 12 min reaction. The results confirmed that the coated fabrics exhibited high catalytic performances, good stability and reusability in consecutive degradation experiments with a degradation rate over 60 % even after 7 degradation cycles; Moreover, it is easily and simply separated from the mixture, by removing the textile sample from the aqueous solution. It is worth mentioning that the PET@CoFe2O4/GO fabrics showed outstanding antibacterial activity against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria with an inhibition diameter zone of up to 13 mm for PET@CoFe2O4/GO (5 %). Overall, these findings are of great importance as they permit the development of a novel multifunctional textile fabric, combining anti-bacterial activity, catalytic performance and mechanical properties. The study provides a textile-based catalyst with improved catalytic performance, re-usability in consecutive degradation reactions and easy catalyst separation compared to traditional supports. Thus, a huge potential application in several fields such as medicine, heterogeneous catalysis, and wastewater treatment.

TiO2-based nitrogen dioxide gas sensor with transparent ordered micro-hollow bump structure prepared by 3D heterogeneous integration technology

This study produces the TiO2 membrane for a transparent ordered micro-hollow-bump (TOMHB) structure using a micro electro mechanical system (MEMS) and 3D heterogeneous integration (HI). The SEM image shows that the diameter and depth of each MHB are 12.5 μm and 8.5 μm. The TEM image shows that a 70 nm-thick TiO2 membrane is uniformly coated onto the MHB using atomic layer deposition (ALD). For NO2 gas sensing, the TiO2 TOMHB gas sensor is measured with and without UV irradiation at a working temperature for the sensor of room temperature, and a measurement time from NO2 injection to exhaust of about 5 min. Without UV irradiation, the gas response is good but the response time is slow and difficult-recoverable. With UV irradiation, the TiO2 TOMHB gas sensor has a fast response and recovery time. Four consecutive stability experiments show that the sensor response has an average value of 9.5 % for NO2 4.25 ppm. The average response time is 7 s and the average recovery time is 144 s. In addition, the TiO2 TOMHB gas sensor is a good selective for NO2 gas. These results show that the TiO2 TOMHB NO2 gas sensor has good stability, reproducibility and selectivity.

Novel S-scheme β-Cu2V2O7/Ni/Pg-C3N4 heterojunction photocatalyst for sunlight-induced degradation of RhB

A novel S-scheme β-Cu2V2O7/Ni/Pg-C3N4 nanocomposite photocatalyst has been advantageously established by propelling β-Cu2V2O7 nanoparticles (NPs) on the top layer of porous graphitic carbon nitride (Pg-C3N4) nanosheets (NSs) using a facile co-precipitation approach. Implementing photoelectrochemical and physicochemical techniques, the crystallinity, purity, optical quality, morphology, chemical composition, and charge separation efficiency of the produced samples were examined. The outcomes indicate that metallic Ni and β-Cu2V2O7 NPs were perfectly encapsulated onto the Pg-C3N4 NSs and well-matched band structures between both semiconductors facilitate the creation of an S-scheme charge transfer path. The fabricated pristine and β-Cu2V2O7/Ni/Pg-C3N4 composite samples were utilized as a catalyst for the removal of rhodamine B (RhB) dye under sunlight irradiation. The β-Cu2V2O7/Ni/Pg-C3N4 nanocomposite exhibits exceptional activity within 60 min of radiation exposure (RhB- 98.56%), whereas β-Cu2V2O7 and Pg-C3N4 show reduced activity (RhB-34.4% and 45.68%). The favourable impact of S-scheme nanocomposite establishment boosted photocatalytic behavior using the intrinsic electric field among Pg-C3N4 NSs and β-Cu2V2O7 and surface plasmon resonance (SPR) effect of metallic Nickel (Ni) NPs for delivering e− and h+ pairs and prolonging the life of charge carriers. According to radical scavenging experiments •O2− is the primary reactive species followed by •OH radicals. The produced nanocomposite has the potential to be employed in large-scale photocatalytic water treatment, as evidenced by the photocatalyst's excellent efficiency and reusability after five consecutive experiments.

Development of tungsten-modified iron oxides to decompose an over-the-counter painkiller, Acetaminophen by activating peroxymonosulfate

Acetaminophen (APAP) is a well-known type of over-the-counter painkillers and is frequently found in surface waterbodies, causing hepatotoxicity and skin irritation. Due to its persistence and chronic effects on the environment, innovative solutions must be provided to decompose APAP, effectively. Innovative catalysts of tungsten-modified iron oxides (TF) were successfully developed via a combustion method and thoroughly characterized using SEM, TEM, XRD, XPS, a porosimetry analysis, Mössbauer spectroscopy, VSM magnetometry, and EPR. With the synthesis method, tungsten was successfully incorporated into iron oxides to form ferrites and other magnetic iron oxides with a high porosity of 19.7 % and a large surface area of 29.5 m2/g. Also, their catalytic activities for APAP degradation by activating peroxymonosulfate (PMS) were evaluated under various conditions. Under optimal conditions, TF 2.0 showed the highest APAP degradation of 95 % removal with a catalyst loading of 2.0 g/L, initial APAP concentration of 5 mg/L, PMS of 6.5 mM, and pH 2.15 at room temperature. No inhibition by solution pHs, alkalinity, and humic acid was observed for APAP degradation in this study. The catalysts also showed chemical and mechanical stability, achieving 100 % degradation of 1 mg/L APAP during reusability tests with three consecutive experiments. These results show that TFs can effectively degrade persistent contaminants of emerging concern in water, offering an impactful contribution to wastewater treatment to protect human health and the ecosystem.

In situ X-ray diffraction evidence of field-induced transitions in a PbHfO3 single crystal

Antiferroelectric (AFE) materials are interesting due to recent discoveries of new prospective applications, although the mechanisms of the phase transitions that are at the heart of these applications remain incompletely understood. This work is devoted to the study of a single crystal of a model AFE, lead hafnate, by X-ray diffraction with in situ application of an electric field to trigger the transition to a polar phase. Two consecutive experiments were carried out on a 35 µm thick plate with [110] surface normal orientation over a field range from 0 to 330 kV cm−1 and back. A sharp drop in the intensity of R- and Σ-type reflections around 225 kV cm−1 was registered, with almost complete disappearance after 250 kV cm−1. This is compatible with a field-induced phase transition from the AFE to the R3m polar phase, which was suggested earlier on the basis of non-diffraction characterizations. X-ray diffraction reveals that the AFE domains with displacements parallel to the field direction react much more smoothly to the field, gradually reducing the AFE order at very small fields instead of holding it almost constant up to the critical field value, which is naturally expected. This expectation is fulfilled for domains with other orientations, but only for the first switching cycle; in the second switching cycle the AFE order already shows a notable decrease at subcritical fields. It is suggested that these observations could be linked with the antiphase domain wall population being affected by the field, which is consistent with the observation of diffuse rods between the Γ and Σ points. Another remarkable observation is the much smoother recovery of the AFE phase compared with its sharp disappearance at the critical field.

Experimental validation of the horizontal resolution improvement by ultra-wideband metasurfaces for GPR systems

Achieving high horizontal resolution is crucial for general non-destructive testing (NDT) applications, and in the domain of ground penetrating radar (GPR), it can be more challenging due to inefficient transmissions of electromagnetic waves into and through complex material under test (MUT). In this study, we showcase the validation results of our recently designed ultra-wideband metasurface (UWM) in improving the horizontal resolution for GPR B-Scan images. This UWM has an ultra-wide working frequency band (100%) from 1 to 3 GHz, in which high-frequency GPR signals can be enhanced and transmitted into MUT. Our fourteen-day consecutive GPR experiments demonstrate that two buried pipes with an edge-to-edge spacing of 8 cm that are hard to distinguish by traditional GPR surveys can be visually identified by depositing the UWM atop the MUT. The underlying mechanism is the sustained and improved transmission of high-frequency signals into the MUT, enabled by the removal of transmission coupling loss by the UWM at the air–MUT interface and the resulting enhanced transmission of more high-frequency components. Our simulations also provide quantitative analysis of such enhanced behavior with a nominal transmittance increase of 30% ∼50%. We believe the horizontal resolution improvement enabled by UWM will open a new corridor for high-resolution GPR system design.

Exploration of morphological, structural, and photocatalytic behaviours of MoS2/WO3 nanocomposites

A lot of people are interested in hybrid nanostructures made of two-dimensional materials like transition metal dichalcogenides and transition metal oxides because they could be used as photocatalysts. This interest stems from their outstanding structural, electronic, and optical properties. The main objective of this paper is how to make a photocatalyst that works better by combining a special photocatalytic system made of MoS2/WO3 nanocomposites in an easy hydrothermal process. The crystalline structure of MoS2, WO3, and MoS2/WO3 nanocomposites was verified by powder X-ray diffraction (PXRD) investigation. Furthermore, scanning electron microscopy (SEM) analysis showed the creation of highly pure MoS2 and MoS2/WO3 composites, which showed a clustering of several spherical nanorods. We performed photocatalytic experiments using methylene blue dye under visible light in the presence of MoS2, WO3, and MoS2/WO3 nanocomposites. We observed that the formation of heterojunction and the increase of active sites were the optimal parameters affecting the photodegradation of methylene blue. The degradation percentages were observed to be 59 %, 55 %, and 90 %, respectively, within 120 min of light irradiation. The results of consecutive experiments explicitly demonstrate the enrichment of the photocatalytic properties of the MoS2/WO3 nanorods. Furthermore, we thoroughly investigated and discussed the mechanism of photodegradation in the MoS2/WO3 nanocomposites.

Halicin: A New Horizon in Antibacterial Therapy against Veterinary Pathogens.

It is crucial to discover novel antimicrobial drugs to combat resistance. This study investigated the antibacterial properties of halicin (SU3327), an AI-identified anti-diabetic drug, against 13 kinds of common clinical pathogens of animal origin, including multidrug-resistant strains. Employing minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assessments, halicin demonstrated a broad-spectrum antibacterial effect. Time-killing assays revealed its concentration-dependent bactericidal activity against Escherichia coli ATCC 25922 (E. coli ATCC 25922), Staphylococcus aureus ATCC 29213 (S. aureus ATCC 29213), and Actinobacillus pleuropneumoniae S6 (APP S6) after 4 h of treatment at concentrations above the MIC. Halicin exhibited longer post-antibiotic effects (PAEs) and sub-MIC effects (PA-SMEs) for E. coli 25922, S. aureus 29213, and APP S6 compared to ceftiofur and ciprofloxacin, the commonly used veterinary antimicrobial agents, indicating sustained antibacterial action. Additionally, the results of consecutive passaging experiments over 40 d at sub-inhibitory concentrations showed that bacteria exhibited difficulty in developing resistance to halicin. Toxicology studies confirmed that halicin exhibited low acute toxicity, being non-mutagenic, non-reproductive-toxic, and non-genotoxic. Blood biochemical results suggested that halicin has no significant impact on hematological parameters, liver function, and kidney function. Furthermore, halicin effectively treated respiratory A. pleuropneumoniae infections in murine models. These results underscore the potential of halicin as a new antibacterial agent with applications against clinically relevant pathogens in veterinary medicine.