Potential Measurements Research Articles

The Synergic Effect of Brine Salinity and Dispersed Clay Particles on Water-in-Heavy Oil Emulsion: Insight into Asphaltene Structure and Emulsion Stability

Summary The research on enhancing oil recovery in sandstone reservoirs through low-salinity waterflooding (LSWF) has been well-documented, while there have been few studies conducted on the impact of emulsion formation in heavy oil due to the incompatibility between the injected brine, clay particles, and heavy oil components. In this study, we explored the synergic role of asphaltene and clay in the process of LSWF by introducing an innovative and thorough experimental approach. Our findings presented new insights into how LSWF in clay-rich sandstone reservoirs can influence the behavior and properties of the water-in-heavy oil emulsions. In this regard, we contacted the heavy oil and brine (with and without clay) for 20 days at 90°C. Then, the emulsion was centrifuged to separate the oil and brine phases. The oil phase was examined by conducting the viscosity, interfacial tension (IFT), Fourier transform infrared spectroscopy (FTIR), and asphaltene onset point (AOP) precipitation experiments. Significant decreases in viscosity and asphaltene precipitation values were observed when crude oil was exposed to clay solutions, as indicated by viscosity and IP-143 results. Furthermore, the zeta potential of clay particles suspended in various brines was determined to assess the electrostatic aspects of rock-oil interactions. The analysis of the emulsion phase indicated that the emulsion stability in the presence of clay increased because of the improvement of asphaltene contribution in the interface. This trend aligns with the zeta potential measurement results. In addition, after examining the pH and conductivity of aged brine in the presence and absence of clay, it was observed that the clay caused the release of hydrogen ions in the brine and then bonded with the dissolved cations, leading to improvement in the emulsion stability. Ultimately, the asphaltene molecular structure was compared via scanning electron microscopy (SEM) and attenuated total reflection analysis before contact with the brine and after separation from the emulsion phase. The results indicated a decrease in the concentration of aliphatic groups in the molecular structure of the remaining asphaltene following the aging of the oil bulk. These new findings can potentially mitigate unwanted emulsion damage in the LSWF in heavy oil recovery.

Effects of Tillage Depth and Lime Application on Acidification Reduction and Nutrient Availability in Vertisol Soil

Cropland acidification seriously restricts sustainable agricultural development. The main purpose of this study was to determine whether deeper tilling could alleviate topsoil acidification to improve the quality of arable land. A soil column incubation experiment simulating tillage depths (10 cm, 30 cm and 50 cm) and lime addition was conducted to determine their effects on soil acidification improvement. The changes in soil pH, exchangeable acidity, ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3−-N), available phosphorus (AP), and microbial phospholipid fatty acids (PLFA) were analyzed. Tillage depth, lime application, and their interaction all had significant impacts on soil pH. T50 (simulated tillage depth of 50 cm) and T50+Lime (simulated tillage depth of 50 cm plus lime) treatments significantly increased the topsoil pH from 5.41 to 6.35 and 7.12, respectively. T50 treatment significantly reduced the soil exchangeable acid content compared to the T10 treatment. The nutrient accumulation along soil column indicated that the T50 and T50+Lime treatments significantly increased NO3−-N and AP content in the >30–50 cm soil layer. Compared with T30, NO3−-N accumulation in the >30–50 cm soil layers of T50 and T50+Lime treatments was 6.62 and 7.93 times higher, respectively. The accumulation of AP in the >30–50 cm soil layers of the T50 and T50+Lime treatments was 1.33 and 1.54 times higher than in the T30 treatment, respectively. These findings imply tillage up to 50 cm without exogenous materials could be a potential measure to reduce topsoil acidification and increase nutrition availability of >30–50 cm soil layers. Tillage of up to 30 cm combined with lime application confers greater benefits, which would particularly impact crops with shallow root systems. Subsequent field experiments will be conducted to further investigate the efficacy of these strategies in enhancing crop yield.

Switching Photoluminescence “On‐Off‐On” for Detection of Chromium (VI) Ion and Ascorbic Acid with N,S‐Codoped Carbon Dots

AbstractA photoluminescent‐based “Turn On → Off → On” technique was adopted for a toxic, heavy metal ion detection, that is, specifically chromium (VI) and a pharmaceutically relevant ascorbic acid molecule. Metal‐free, environmentally benign, and fluorescent carbon dots, a potential vehicle for spectrofluorometric detection, were successfully deployed as sensors. Carbon dots synthesized from citric acid and sulfanilamide conserve the fragments of the precursor molecule on the surface. Zeta potential measurement evidenced the positively charged carbon nanoparticles physically interact with the Cr(VI)/Cr2O72− in acidic pH, resulting in a remarkable quenching in net fluorescence. Thorough studies revealed that the static quenching and inner filter effect were responsible for the reduction in fluorescence intensity. We have demonstrated a new rapid (in seconds) detection platform for Cr(VI) and ascorbic acid.

Are Danes really happier than Swedes and Australians? A comparative analysis of subjective well-being measurement issues in Denmark, Sweden, and Australia

This study examines the reliability of cross-national subjective well-being (SWB) survey data, by corroborating the persistently high SWB-rankings of Denmark through a comparison to Sweden and Australia, two countries with similar or superior social, economic, and health indicators. Our research focuses on both the affective and the cognitive component of SWB, with a special emphasis on the affective component. We investigate four potential measurement issues that could contribute to Denmark’s elevated SWB scores: linguistic inconsistencies in survey translations, variations in answering scale usage, recall bias of affect, and positivity bias in life satisfaction judgments. To address these concerns, we utilize multi-group confirmatory factor analysis, analyse emotion-focused anchoring vignettes, examine affect items across varying time frames, and contrast overall life satisfaction assessments with those of domain-specific satisfaction. Despite accounting for various potential measurement issues, our results reveal that Danes consistently report higher SWB than their Swedish and Australian counterparts, although the differences are small for several of the measures. This finding implies that the SWB survey-data is reliable in this case, and that Denmark's high SWB rankings are not attributable to measurement biases but may indeed signify genuinely high levels of SWB. This paper adds to the growing body of literature on cross-national SWB comparisons and might provide insights for researchers aiming to compare well-being across countries.

Novel CD44-Targeted Albumin Nanoparticles: An Innovative Approach to Improve Breast Cancer Treatment.

This study introduces novel CD44-targeted and redox-responsive nanoparticles (FNPs), proposed as doxorubicin (DOX) delivery devices for breast cancer. A cationized and redox-responsive Human Serum Albumin derivative was synthesized by conjugating Human Serum Albumin with cystamine moieties and then ionically complexing it with HA. The suitability of FNPs for cancer therapy was assessed through physicochemical measurements of size distribution (mean diameter of 240 nm), shape, and zeta potential (15.4 mV). Nanoparticles possessed high DOX loading efficiency (90%) and were able to trigger the drug release under redox conditions of the tumor environment (55% release after 2 h incubation). The use of the carrier increased the cytotoxic effect of DOX by targeting the CD44 protein. It was shown that, upon loading, the cytotoxic effect of DOX was enhanced in relation to CD44 protein expression in both 2D and 3D models. DOX@FNPs significantly decrease cellular metabolism by reducing both oxygen consumption and extracellular acidification rates. Moreover, they decrease the expression of proteins involved in the oxidative phosphorylation pathway, consequently reducing cellular viability and motility, as well as breast cancer stem cells and spheroid formation, compared to free DOX. This new formulation could become pioneering in reducing chemoresistance phenomena and increasing the specificity of DOX in breast cancer patients.

Optimizing tuberculosis control: a comprehensive simulation of integrated interventions using a mathematical model

Tuberculosis (TB) remains a formidable global health challenge, demanding effective control strategies to alleviate its burden. In this study, we introduce a comprehensive mathematical model to unravel the intricate dynamics of TB transmission and assess the efficacy and cost-effectiveness of diverse intervention strategies. Our model meticulously categorizes the total population into seven distinct compartments, encompassing susceptibility, vaccination, diagnosed infectious, undiagnosed infectious, hospitalized, and recovered individuals. Factors such as susceptible individual recruitment, the impact of vaccination, immunity loss, and the nuanced dynamics of transmission between compartments are considered. Notably, we compute the basic reproduction number, providing a quantitative measure of TB transmission potential. Through this comprehensive model, our study aims to offer valuable insights into optimal control measures for TB prevention and control, contributing to the ongoing global efforts to combat this pressing health challenge.

TMS-evoked potentials unveil occipital network involvement in patients diagnosed with Parkinson’s disease within 5 years of inclusion

Distinguishing Parkinson’s disease (PD) subgroups may be achieved by observing network responses to external stimuli. We compared TMS-evoked potential (TEP) measures from stimulation of bilateral motor cortex (M1), dorsolateral prefrontal cortex (DLPFC), and visual cortex (V1) between 62 PD patients (age: 69.9 ± 7.5) and 76 healthy controls (age: 69.2 ± 4.3) using a TMS–EEG protocol. TEP measures were analyzed using two-way ANCOVA adjusted for MOCA. PD patients were divided into tremor dominant (TD), non-tremor dominant (NTD) and rapid disease progression (RDP) subgroups. PD patients showed lower wide-waveform adherence (wWFA) (p = 0.025) and interhemispheric connectivity (IHCCONN) (p < 0.001) compared to healthy controls. Lower occipital IHCCONN correlated with advanced disease stage (r = −0.37, p = 0.0039). The RDP and NTD groups showed lower wWFA in response to occipital stimulation than the TD group (p = 0.005). Occipital TEP measures identified RDP patients with 85% accuracy. These findings demonstrate occipital network involvement in early PD stages, suggesting that TEP measures offer insights into altered networks in PD subgroups.

Charge Transfer Kinetics and Thermodynamics Control the Energy Conversion Efficiency of a Gallium Phosphide Solar Hydrogen Photocathode.

P-type gallium phosphide (GaP) photocathodes for hydrogen evolution from water have a theoretical energy conversion efficiency of 12% based on the 2.4 eV optical band gap of the material. The performance of actual GaP photocathodes is much lower, for reasons not entirely clear. Here we use vibrating Kelvin probe surface photovoltage (VKP-SPV), open circuit potential (OCP) measurements, and photoelectrochemical (PEC) experiments to evaluate the kinetic and thermodynamic factors that control energy conversion with GaP photocathodes for the hydrogen evolution reaction (HER). We find that the open circuit photovoltage of the bare GaP-H2O junction is limited by recombination at surface states and that an CdS overlayer increases both photovoltage and photocurrent due to formation of a n-p-junction. An optimized GaP/CdS/Pt photocathode drives hydrogen evolution with a quantum efficiency of 62% at 400 nm and 0.0 V RHE and an open circuit photovoltage of 0.43 V at 250 mW cm-2. The Pt cocatalyst increases the photocurrent due to improve HER kinetics but reduces the photovoltage by promoting recombination. Added hydrogen or oxygen gas raise or lower the photovoltage by modifying the electrostatic barrier (band bending) in GaP. This shows that the GaP/CdS junction is not "buried" but behaves like a Schottky junction whose charge separating properties are controlled by the electrochemical potential of the electrolyte. The dynamic junction properties need to be considered in the design of optimized hydrogen evolution photoelectrodes and photocatalysts. Additionally, the work reveals that PEC or OCP measurements tend to underestimate the photovoltage because they do not account for changes in the electrochemical potential at the electrode-liquid contact. In contrast, the VKP-SPV method provides the open circuit photovoltage value directly. By combining the photovoltage data with OCP data, the minority carrier electrochemical potential at the electrode-liquid contact can be measured in a contactless way. This provides an improved understanding of illuminated photoelectrodes for the production of solar fuels.

Black grouse (Lyrurus tetrix) population status, reasons for decline and potential conservation measures from Western and Central Europe to Fennoscandia: a literature review

The long-term decline of the black grouse population throughout Europe is influenced by many factors that affect populations differently depending on the distribution range, from Central Europe to the Scandinavian countries. Therefore, we analyzed available literature sources to describe the main reasons for the population decline of this species and to suggest conservation measures. In total, 228 pieces of literature from 1955 to 2024 were analyzed for this study. Based on the literature analysis, it is clear that the drivers of population decline differ across the distributional range. In Central Europe, where the population is declining rapidly, habitat loss and forest fragmentation are crucial factors, as is the negative impact of tourism. In Scandinavia, where the population is gradually declining, decreasing breeding success and increasing chick mortality rates are generally considered the main negative factors. However, these factors also affect black grouse populations in Central Europe. It is crucial to acknowledge that a significant proportion of the contributing factors, such as predation and habitat loss, can be attributed to human activities. Therefore, it is necessary to emphasize that environmental protection should work hand in hand with wildlife managers to improve the situation.

Right visual field advantage in orientation discrimination is influenced by biased suppression

Visual input is not equally processed over space. In recent years, a right visual field advantage during free walking and standing in orientation discrimination and contrast detection task was reported. The current study investigated the underlying mechanism of the previously reported right visual field advantage. It particularly tested if the advantage is driven by a stronger suppression of distracting input from the left visual field or improved processing of targets from the right visual field. Combing behavioural and electrophysiological measurements in a mobile EEG and augmented reality setup, human participants (n = 30) in a standing and a walking condition performed a line orientation discrimination task with stimulus eccentricity and distractor status being manipulated. The right visual field advantage, as demonstrated in accuracy and reaction time, was influenced by the distractor status. Specifically, the right visual field advantage was only observed when the target had an incongruent line orientation with the distractor. Neural data further showed that the right visual field advantage was paralleled by a strong modulation of neural activity in the right hemisphere (i.e. contralateral to the distractor). A significant positive correlation between this right hemispheric event related potential (ERP) and behavioural measures (accuracy and reaction time) was found exclusively for trials in which a target was presented on the right and an incongruent distractor was presented on the left. The right hemispheric ERP component further predicted the strength of the right visual field advantage. Notably, the lateralised brain activity and the right visual field advantage were both independent of stimulus eccentricity and the movement state of participants. Overall, our findings suggest an important role of spatially biased suppression of left distracting input in the right visual field advantage as found in orientation discrimination.

Menopausal state and rheumatoid arthritis: a systematic review and meta-analysis.

Rheumatoid arthritis (RA) is a chronic inflammatory condition primarily affecting the joints. The higher prevalence of RA among females, combined with the known effects of sex hormones on immune function, has led researchers to investigate the potential relationship between menopausal status and the risk, severity, or progression of RA. This systematic review and meta-analysis aimed to determine the association between menopause and rheumatoid arthritis. In 2023, we conducted a comprehensive search across multiple databases, including Google Scholar, Scopus, PubMed/MEDLINE, Science Direct, Web of Science, EMBASE, Springer, and ProQuest. The search aimed to identify studies exploring the association between menopause and rheumatoid arthritis. Our analysis revealed that post-menopausal women had a higher risk of developing rheumatoid arthritis compared to pre-menopausal women, with an estimated odds ratio of 1.35 (95% CI: 1.04-1.67). Additionally, women who experienced early menopause (defined as onset before age 45) showed significantly higher odds of developing RA, with an odds ratio of 2.97 (95% CI: 1.73-4.22). These findings highlight the importance of considering menopausal status when assessing the risk of RA development in women. The results suggest that post-menopausal women, particularly those who experience early menopause, may be at higher risk for developing RA. Further research in this area could provide valuable insights into potential preventive measures and targeted interventions for high-risk individuals.

Impacts of fire and flooding on sediment carbon storage in a large, forested floodplain

Summary Natural disturbances influence wetland carbon cycling, and fire is a key driver of terrestrial carbon stocks. However, the influence of fire on wetland carbon cycling remains poorly understood. Here, we investigated how prescribed fire and wildfire impact soil carbon storage in a forested floodplain of south-eastern Australia. We sampled four areas within Murray Valley National Park, the world’s largest river red gum (Eucalyptus camaldulensis) stand, and compared soil carbon (C), nitrogen (N) and C:N ratios between control (unburnt in the 50 years prior to sampling), prescribed burn and wildfire-impacted floodplain areas. Mean soil C and N concentrations were 4.7% ± 0.32% and 0.36% ± 0.02%, respectively, and mean C:N ratios were 14.23 ± 0.33. Carbon concentrations and C:N were highest in control areas of the floodplain, while N concentrations were highest at wildfire-impacted areas. However, flood frequency was a stronger driver of soil C than fire disturbance. Soils at more frequently flooded areas had higher C concentrations compared to less frequently flooded areas, suggesting that resilience to C loss through fire could be enhanced through hydrological restoration. We believe this warrants further research as a potential nature-based climate measure. Mean C density data indicate soil C stocks of 9.4 Tg across Barmah-Millewa Forest, highlighting the significant carbon storage value of this ecosystem.

Utilising Design Thinking To Alleviate The Effects Of Covid-19 On Civil Servant Operations

The phenomenon of design thinking has a significant potential to form a synergistic interaction of individual abilities of leaders, managers and civil servants in the context of global challenges caused by the consequences of the COVID-19 pandemic. Against the backdrop of these issues, ensuring the effectiveness of key state institutions and organisations is of particular relevance, which, in turn, requires a detailed analysis of potential measures to counteract negative impacts. The aim of the study is to analyse the potential of design thinking in the context of developing and implementing a comprehensive mechanism for overcoming the effects of COVID-19 on the activities of civil servants. The article focuses on the functionality of design thinking in terms of civil servants’ basic professional and personal skills. The possibility of their allocation as separate indicators of the concept is considered. The structural elements of design thinking are outlined, and each of them is described in detail. The imperative for establishing a unified mechanism to address the pandemic’s existing and potential adverse consequences is clearly demonstrated. The peculiarities of integrating design thinking based on the Stanford concept into the work of civil servants in Ukrainian public institutions are described. It is assumed that implementing this goal will increase the efficiency of civil servants, forming an effective mechanism for mitigating the risks caused by the pandemic. The author identifies sustainable principles that can facilitate the operational and strategic management of team performance in the civil service. The priorities for further improvement of design thinking skills to improve the efficiency of public institutions are revealed. The specifics of the Stanford model as an effective tool for team development and management decision-making are investigated. The main principles of the mechanism for overcoming the destructive effects of COVID-19 through the introduction of design thinking technology, which helps improve public institutions’ efficiency and quality of work and create favourable conditions for team effectiveness, are analysed. The study’s results have practical value in the development, improvement and modernisation of the design thinking concept to minimise the impact of the adverse effects of the COVID-19 pandemic.

Hevea brasiliensis rubber particles' fluid interfaces reveal size impact on early coagulation steps

Natural rubber originates from the coagulation of rubber particles (RP) from Hevea brasiliensis latex. The size distribution of Hevea RP is bimodal with the presence of small rubber particles (SRP) and large rubber particles (LRP). This study aims at getting a better understanding of the early coagulation steps of Hevea RP taking into account the particle size. SRP and LRP were obtained by centrifugation of freshly tapped ammonia-free latex from RRIM600 clone. Size and zeta potential measurements showed that both RP fractions were efficiently separated and stable in basic buffer. SRP and LRP dispersions were placed in a Langmuir trough and RP were let to adsorb at the air-liquid interface to form interfacial films. Surface tension and ellipsometry indicate that the formation kinetics and the stabilization of the film at the air-liquid interface are faster for SRP than LRP. Moreover, the arrangement of RP at the interface differs between SRP and LRP, as shown by Brewster angle microscopy, atomic force microscopy and confocal laser scanning microscopy. First, the RP membrane and cis-1,4-polyisoprene core spread at the air-liquid interface before clustering. Then, while the SRP fuse, the LRP keep their structure in individual particles in floating aggregate. The role of the non-isoprene molecules on the different organization of SRP and LRP films is discussed, the one of the two major RP proteins, SRPP1 (Small Rubber Particle Protein) and Rubber Elongation Factor (REF1) in the early coagulation steps.

Indium oxide layer dual functional modified bismuth vanadate photoanode promotes photoelectrochemical oxidation of water to hydrogen peroxide.

The photoelectrochemical (PEC) dual-electron pathway for water oxidation to produce hydrogen peroxide (H2O2) shows promising prospects. However, the dominance of the four-electron pathway leading to O2 evolution competes with this reaction, severely limiting the efficiency of H2O2 production. Here, we report a In2O3 passivator-coated BiVO4 (BVO) photoanode, which effectively enhances the selectivity and yield of H2O2 production via PEC water oxidation. Based on XPS spectra and DFT calculations, a heterojunction is formed between In2O3 and BVO, promoting the effective separation of interface and surface charges. More importantly, Mott-Schottky analysis and open-circuit potential measurements demonstrate that the In2O3 passivation layer on the BVO photoanode shifts the hole quasi-Fermi level towards the anodic direction, enhancing the oxidation level of holes. Additionally, the widening of the depletion layer and the flattening of the band bending on the In2O3-coated BVO photoanode favor the generation of H2O2 while suppressing the competitive O2 evolution reaction. In addition, the coating of In2O3 can also inhibit the decomposition of H2O2 and improve the stability of the photoanode. This work provides new perspectives on regulating PEC two/four-electron transfer for selective H2O2 production via water oxidation.

Effect of sodium dodecyl sulphate on the rheological and carbon sequestration properties of cemented paste backfill with CO2 injection

Cemented paste backfill (CPB) is a technology that has a positive impact on both the environment and mining safety. In recent years, it has been widely applied and developed. To improve the carbon sequestration efficiency of CPB, air-entraining agent addition to CO2-injected CPB (CO2-CPB) has been proposed. However, the influence of air-entraining agents on the rheological and carbon sequestration properties of CO2-CPB has not been investigated to date. Therefore, sodium dodecyl sulphate (SDS), an air-entraining agent, was selected in this study, and the rheological and carbon sequestration properties of CO2-CPB added with SDS were comprehensively investigated. CO2-CPB samples with 0.0‰, 0.5‰, 1.0‰, and 1.5‰ SDS were prepared, and the rheological parameters (yield stress and viscosity) were tested after curing for 0, 0.25, 1, and 2 h. Gas content testing, microscopic analysis, and zeta potential measurements were performed. The results show that SDS addition decreased the yield stress and viscosity of CO2-CPB at 0–1 h; however, the yield stress and viscosity increased at 2 h. SDS addition significantly improved the carbon sequestration performance of CO2-CPB. The findings of this study have important implications for carbon sequestration development in CPB and solid waste utilisation.

Intracellular delivery of antiviral shRNA using penetratin-based complexes effectively inhibits respiratory syncytial virus replication and host cell apoptosis

BackgroundCell-penetrating peptides (CPPs) are effective for delivering therapeutic molecules with minimal toxicity. This study focuses on the use of penetratin, a well-characterized CPP, to deliver a DNA vector encoding short hairpin RNA (shRNA) targeting the respiratory syncytial virus (RSV) F gene into infected cells. RSV is known to cause severe lower respiratory infections in infants and poses significant risks to immunocompromised individuals and the elderly. We evaluated the antiviral efficacy of the penetratin-shRNA complex by comparing its ability to inhibit RSV replication and induce apoptosis with ribavirin treatment.MethodsPenetratin-shRNA complexes were prepared at different ratios and analyzed using gel retardation assays, dynamic light scattering, and zeta potential measurements. The complexes were tested in HEp-2 and A549 cells for transfection efficiency, cytotoxicity, viral load, and apoptosis using plaque assays, real-time reverse transcription-polymerase chain reaction (RT-PCR), DNA fragmentation, propidium iodide staining, and caspase 3/7 activation assays.ResultsThe gel shift assay determined that a 20:1 CPP-to-shRNA ratio was optimal for effective complexation, resulting in particles with a size of 164 nm and a zeta potential of 8.7 mV. Transfection efficiency in HEp-2 cells was highest at this ratio, reaching up to 93%. The penetratin-shRNA complex effectively silenced the RSV F gene, reduced viral titers, and decreased DNA fragmentation and apoptosis in infected cells.ConclusionPenetratin effectively delivers shRNA targeting the RSV F gene, significantly reducing viral load and preventing apoptosis without toxicity. This approach surpasses Lipofectamine and shows potential for future therapeutic interventions, especially when combined with ribavirin, against RSV infection.Graphical

Exploring the impact of poly(sodium styrene sulfonate) dispersants’ architecture on their performance in coal water slurry preparation

In this work, the architecture of poly(sodium styrene sulfonate) (PSSNa) dispersants were flexibly tailored by various strategies. Three categories of PSSNa dispersants with different topologies were obtained, namely, linear structured PSSNa (1-A-PSSNa), three-arm star PSSNa (3-AS-PSSNa) and six-arm star PSSNa (6-AS-PSSNa). The molecular weights (Mn) of these dispersants were adjusted in the range of 3200–26,200 g/mol by varying the feeding ratio of monomer to initiator. In addition, the polydispersity index (PDI) of resultant dispersants were also varied by using different polymerization technologies, such as atom transfer radical polymerization (ATRP) and conventional free radical polymerization technique (RP). Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) verified these architecture parameters of resultant PSSNa dispersants. Afterwards, the impact of these architectural factors on the performance of PSSNa dispersants in coal water slurry (CWS) preparation were evaluated. The results revealed that with the Mn of dispersants increased from 9800 to 26,200 g/mol, the apparent viscosity of CWS increased by around 11 %. The comparison between dispersants with approximate Mn (26,200 and 26,900 g/mol) and very different PDI (1.27 and 2.25) indicated that wide PDI are favourable for the performance. This work also confirmed that the topology of dispersants has a significant impact on their performance. The maximum coal loaded can increase from 63.9 % to 64.3 % when 1-A-PSSNa dispersant was replaced by 6-AS-PSSNa. Meanwhile, these architectural factors have a limited impact on the fluid type of CWSs, as all CWSs obtained in this work were pseudoplastic fluids regardless of the used dispersants. The potential mechanism was investigated using various technologies, such as the measurements of zeta potentials, contact angles, and low-field nuclear magnetic resonance spectra. The results revealed that topologizing did not alter the interaction between dispersant and coal surface. However, due to the special features of topological polymers, they can grant adsorbed coal particles with enhanced electrostatic repulsion and steric hindrance, which facilitated the dispersion of coal particles.

Infiltration of secondary treated wastewater into an oxic aquifer: Hydrochemical insights from a large-scale sand tank experiment

To mitigate groundwater level decline, managed aquifer recharge (MAR) with secondary treated wastewater (STWW) is increasingly considered and implemented. However, the effectiveness and potential risks of such systems need evaluation prior to implementation. In this study, we present a large-scale sand tank experiment to analyse processes related to the infiltration of real STWW through the vadose zone and subsequent mixing with oxic native groundwater. The varying composition of STWW from 15 infiltration cycles over six months of operation and the retention times were the main drivers of the observed processes, which were characterized by a wide range of analytical techniques such as in situ high-resolution oxidation–reduction potential (ORP) measurements, closed mass balances of solutes, characterization of dissolved organic carbon (DOC), stable nitrate isotopes analysis, as well as numerical flow and transport modelling. Depending on the composition and infiltration rates of the STWW, both nitrification and denitrification could be observed, even simultaneously at different locations in the tank. Furthermore, due to the variability of the real STWW we observed enhanced arsenic mobilisation during times of elevated phosphate concentrations of the infiltrating STWW. Additionally, uranium was mobilised in our experimental system via carbonate mineral dissolution caused by the infiltrating STWW which was undersaturated of calcite for all infiltration cycles. Overall, our results showed the importance of conducting studies with waters of complex matrix, such as real STWW, and considering mixing with groundwater to assess the full range of possible processes encountered at MAR field sites.

Long-term effects of silver nanoparticles and mineral nutrition components on the photosynthetic processes, chloroplast ultrastructure and productivity of Solanum lycopersicum plants

The effects of silver nanoparticles (AgNPs), both alone and in combination with mineral nutrients, on the growth and photosynthesis of Solanum lycopersicum plants during ontogeny were studied. The experiment involved weekly applications of 10 μmol of AgNPs for 15 weeks in a greenhouse over a summer period. A comprehensive characterization of the AgNPs was performed via TEM, ESI/EELS, and zeta potential measurements before and throughout the experiment. The activity of PSII, stomatal conductivity, photosynthesis, transpiration and respiration rates were measured, and the photosynthetic pigments, chloroplast ultrastructure, and dry and fresh masses of leaves, roots, and fruits were assessed. The results indicated that combining AgNPs with mineral nutrients increased PSII activity and the photosynthesis rate and altered the chloroplast ultrastructure. However, the use of mineral nutrients or AgNPs alone did not induce these changes. Atomic absorption spectrometry detected AgNPs in all the plant organs except the fruits. The highest fruit yield was associated with Veni Prisma®, a commercial product containing colloidal silver, which also caused desynchronized fruit maturation. This study hypothesizes that the synergistic effect of AgNPs and mineral nutrients enhances silver accumulation in chloroplasts, improving light utilization and photosynthetic efficiency, particularly under low light, thus increasing fruit quantity and dry mass. Conversely, long-term use of AgNPs alone was accompanied by silver accumulation outside the chloroplasts and did not lead to increased photosynthesis or an increase in fresh fruit mass.