Soluble Research Articles

Poly-3,4-dihydroxybenzylidenhydrazine, a different analogue of polydopamine

Abstract In this article, 3,4-dihydroybenzylidenehydrazine is synthesized for the first time, and its properties as a dopamine analogue for polymerization are investigated. Using an oxidative polymerization reaction, the reaction mechanism as well as the coating ability of the new polymer is determined and compared to that of polydopamine. The polymerization reactions were performed in a mixture of methanol–water with NaIO4 as an oxidation reagent. The polymer was used as a coating on both glass surfaces with a thickness of ∼5 nm as determined by AFM, as well as on TiO2 nanoparticles. For the latter, SEM/TEM and the pH-dependent variation of zeta potential were measured. As a free polymer, poly-3,4-dihydroxybenzylidenhydrazine was investigated by UV-Vis, ss-NMR, and FTIR, and a variety of monomeric units were found in the polymer matrix. The solubility in methanol or DMSO of the monomer and the slight solubility of the polymer allowed us to study the fluorescence and cyclic voltammetry properties for both the monomer and polymer.

Unraveling short-term O2 contamination on under deposit corrosion of X65 pipeline steel in CO2 saturated solution

The impact of short-term O2 contamination on the deposit-covered pipeline steel under a CO2-saturated solution was investigated using steel coupon and wire beam electrode. Results show that the brief exposure to O2 destroyed the FeCO3 film, and converted it into porous iron oxides, weakening its protection property. However, upon CO2 reinjection, the dense FeCO3 film regrew soon underneath the damaged FeCO3 layer on the bare steel, restoring its protective properties. Conversely, the localized corrosion beneath the deposits persisted and worsened, fueled by macro-cell current between the bare steel and the deposit-covered steel.

HSPiP, Computational, and Thermodynamic Model-Based Optimized Solvents for Subcutaneous Delivery of Tolterodine Tartrate and GastroPlus-Based In Vivo Prediction in Humans: Part I.

Tolterodine tartrate (TOTA) is associated with adverse effect, high hepatic access, varied bioavailability, slight aqueous solubility, and short half-life after oral delivery. Hansen solubility parameters (HSP, HSPiP program), experimental solubility (T = 298.2 to 318.2K and p = 0.1MPa), computational (van't Hoff and Apelblat models), and thermodynamic models were used to the select solvent(s). HSPiP predicted PEG400 as the most suitable co-solvent based on HSP values (δd = 17.88, δp = 4.0, and δh = 8.8 of PEG400) and comparable to the drug (δd = 17.6, δp = 2.4, and δh = 4.6 of TOTA). The experimental mole fraction solubility of TOTA was maximum (xe = 0.0852) in PEG400 confirming the best fit of the prediction. The observed highest solubility was attributed to the δp and δh interacting forces. The activity coefficient (ϒi) was found to be increased with temperature. The higher values of r2 (linear regression coefficient) and low RMSD (root mean square deviation) indicated a good correlation between the generated "xe" data for crystalline TOTA and the explored models (modified Apelblat and van't Hoff models). TOTA solubility in "PEG400 + water mixture" was endothermic and entropy-driven. IR (immediate release product) formulation can be tailored using 60% PEG400 in buffer solution for 2mg of TOTA in 0.25mL (dosing volume). The isotonic binary solution was associated with a pH of 7.2 suitable for sub-Q delivery. The approach would be a promising alternative with ease of delivery to children and aged patients.

Microencapsulation of star anise essential oil: Preparation, characterization, in vitro digestion, and biological activity

Star anise essential oil (SAEO) has garnered significant attention for its potent bioactivities. However, the instability and poor water solubility of SAEO limit its application in the food and pharmaceutical industries. To overcome these challenges and improve bioavailability, we encapsulated SAEO within β-cyclodextrin (β-CD) using a saturated aqueous solution method. Characterization techniques including Fourier transform infrared spectroscopy, Scanning electron microscopy, X-ray diffraction, and Thermogravimetric-differential scanning calorimetry confirmed the successful formation of SAEO and β-CD inclusion complex (SAEO-IC) with good thermal stability. The inclusion complex had a yield of 63.18 ± 3.18% and an oil content of 9.32 ± 0.36%. In vitro digestion studies revealed the stability of SAEO-IC in gastric conditions, with the primary release of active ingredients occurring in the intestine. Moreover, the encapsulation process preserved the antioxidant properties of SAEO and demonstrated enhanced antimicrobial and anti-tumor activity, suggesting that SAEO-IC has the potential to serve as a natural antimicrobial and anticancer agent.

Numerical simulation of heavy metal migration in stabilized soils under multi-field coupling

Heavy metal contamination of soils has become a global issue. In pursuit of a reference for the management of heavy metal pollution, numerical simulations were used here to investigate the migration pattern of heavy metals in soil under multi-field coupling of rainfall, temperature, and hydraulic conductivity. Models were built using TOUGHREACT, and measured and simulated values were compared with those of existing studies to verify the accuracy of the software in simulating coupled water vapor-thermal transport and rainfall infiltration. Taking Nanjing rainfall data as an example, the transport pattern of zinc in soil under multi-field coupling was explored. Although evaporation and rainwater infiltration were found to increase with the temperature, the effects of evaporation and temperature counteracted each other, resulting in a weak influence of temperature on heavy metal transport. The hydraulic conductivity of stabilized soil was the main factor controlling zinc migration, with the saturation and heavy metal concentration clouds of soil columns tending to stabilize when the hydraulic conductivity of solidified soil was under 1 × 10-11 m/s.

Impaired Long-Chain Fatty Acid Metabolism in Carnitine Palmitoyltransferase II Knockout Mouse Leads to Chronic Pancreatitis

Background: To support high rates of protein synthesis, pancreatic acinar cells must generate large quantities of ATP. Mitochondrial dysfunction and impaired energy metabolism play a significant role in the development of pancreatitis. Patients with elevated plasma triglycerides are at increased risk for development of severe acute pancreatitis. Carnitine palmitoyltransferase II (CPT2) is required for importing and thus metabolizing long-chain fatty acids (LCFAs) in mitochondria. To inhibit LCFA metabolism, we utilized the CPT2acinarKO mouse to probe the consequences of impaired LCFA import on pancreatic function. Hypothesis: Loss of CPT2 causes an accumulation of long-chain acylcarnitines and disruption of the tissue acylcarnitine/free carnitine ratio which is thought to alter cellular function. Given acinar cells’ high metabolic requirement, impaired LCFA utilization would reduce energy production, secretory function, and alter pancreatic lipid composition. Methods: We generated mice lacking CPT2 specifically in acinar cells (CPT2acinarKO) by crossing tamoxifen-inducible, Elastase-Cre mice with CPT2 floxed mice. Mice were fed a high fat (60% kcal fat), low fat (10% kcal fat), or chow (14% kcal fat) diet for 12 weeks. Analysis of fat accumulation, edema, and fibrosis was performed with H&E and picrosirius staining. Mass Spec. lipid profiling was performed in pancreas and serum. Acinar cells were isolated from wildtype, CPT2 floxed, and CPT2acinarKO mice to assess secretory function, ATP levels, and necrosis via lactate dehydrogenase (LDH) release. Results: Histologic examination revealed CPT2acinarKO mice on all three diets displayed pancreatic fat accumulation. Strikingly, CPT2acinarKO mice fed a chow or low fat diet developed chronic pancreatitis with a 25% loss in pancreatic weight, immune cell infiltration, edema, and fibrosis. As anticipated, long-chain acylcarnitines were significantly elevated in CPT2acinarKO pancreas. Assessment of secretion in 2 weeks post tamoxifen cells revealed significantly reduced maximal (10 pM) and supramaximal (1 nM) cholecystokinin (CCK) stimulated amylase release as a percent of total cellular amylase. Acini isolated at 4 weeks post tamoxifen revealed significantly increased basal secretion and reduced maximal and supramaximal CCK stimulated amylase release. When normalized to cellular DNA, secretion was similar between CPT2acinarKO and CPT2 floxed acinar cells indicating CPT2acinarKO cells had reduced amylase levels. Wildtype acinar cells treated with unsaturated and saturated free fatty acid concentrations as low as 100 μM for 3 hours caused significant necrosis. CPT2acinarKO pancreas had significantly decreased ATP levels indicative of mitochondrial dysfunction. Conclusion: Loss of CPT2 in the pancreatic acinar cells impairs LCFA import, reduces ATP levels, disrupts the secretory pathway, promoting chronic pancreatitis. In contrast to other CPT2 knockout models, pancreatitis occurs independent of high fat feeding in CPT2acinarKO mice. Further investigation is needed to identify metabolic alterations leading to acinar damage and mitochondrial dysfunction following the loss of CPT2. UW-Madison Comprehensive Diabetes Center Pilot Grant. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Fluoride Removal from Aqueous Solution Using Thermally Treated Dolomite Powder as Adsorbent in the Fixed Bed Column

Abstract Aim: The objective of this paper was to investigate the ability of thermally treated dolomite powder (TTDP) to remove fluoride ions from wastewater in a fixed bed column system, and to understand how different operating parameters such as bed height, initial fluoride concentration, and flow rate of influent affected the performance of the system. Materials and Methods: The researchers used several different models to analyze the data collected from the column experiments, and they also characterized the TDP adsorbent using field emission scanning electron microscopy and X-ray diffraction in order to understand its surface morphology. Results: Adsorption capacity increased with the initial fluoride concentration and decreased with bed height. Saturation concentration increases with an initial concentration of fluoride and decreases with bed height and flow rate of influent. Error analysis between experimental results and model results has been done using different predefined error functions. Regeneration of TDP adsorbent is done using a 1N NaOH solution. Conclusions: The breakthrough time increases with a low flow rate of 15 ml/min, low influent concentration of 5 ppm, and higher bed depth of 20 cm. The experimental data from the fixed bed column for fluoride removal are well fitted with all classic models, and the coefficient of regression is close to unity. Regeneration studies have shown that the adsorbent (TTDP) can undergo three cycles of regeneration.

Development of test instruments to measure problem-solving and science literacy of grade XI students on ion equilibrium material in salt hydrolysis

Low science literacy in students will have an impact on students' ability to solve problems. To improve it, it is necessary to develop an assessment instrument in the form of a science literacy instrument. This study aims to develop valid, reliable problem solving and science literacy assessment instruments for students. The material chosen is ion equilibrium in salt solution. The research was conducted in high, medium and low ability schools namely SMA Negeri 1 Pekanbaru, SMA Negeri 12 Pekanbaru and SMA Negeri 15 Pekanbaru. There are 16 questions out of 20 questions that are constructively valid with a correlation value> 0.36. The questions developed have met the reliability requirements with a Cronbach alpha coefficient value greater than 0.6, reaching a value of 0.874. The level of difficulty of questions between 0.3 -0.7 is in the good enough category and differentiating power ≥ 0.3. Based on two trials, namely one-on-one trials and limited trials, the same results were obtained that the assessment instruments developed for students had very good readability aspects (85%), good adequacy aspects (64%) and assessment instruments developed for teachers had very good feasibility aspects (91%). There is a significant difference in the ability of students in high schools with medium and low ability schools.

Investigation on The Effect of Low Frequency Ultrasound on The Crystallization of a Pharmaceutical Compound L+ Ascorbic Acid

One of the most crucial processes in the chemical processing industry is crystallization, which has the major challenge of producing solid products with the required purity and properties. The standard crystallization methods have various processing limitations; hence, research into alternative methods like ultrasonic-assisted crystallization has been at the forefront. The present work investigates the application of low-frequency ultrasound irradiation (40 kHz) for improving the cooling crystallization of ascorbic acid. The impact of ultrasonic irradiation on crystal size, shape, and induction time has been studied, and a comparison with the conventional method has been made. The standing time had a minor effect on particle size on average, while the initial temperature had a far more significant impact. Photographic analysis using image-analysis software indicated that when ultrasound was applied to the saturated solutions, the resulting crystals were smaller and more uniform in size and shape. The resultant crystal grows predominantly in a single direction, resembling thin prisms. The use of ultrasound was also shown to reduce the induction time significantly. This ultrasonic impact is stronger at lower initial temperatures. Indeed, the smallest induction time of 300 s was obtained for sonicated solutions at an initial temperature of 65°C and ultrasonic power of 250 w. When different levels of ultrasonic power dissipation were tested, it was established that the time required for the first nuclei to appear decreased as the power increased. There was, nevertheless, a marginal impact on average crystal size.

Molecular Characterization of Gaseous Organic Acids and Nitrogen‐Containing Compounds From Crop Straw and Wood Burning

AbstractBiomass burning serves as important sources of volatile organic compounds (VOCs), yet our understanding of the molecular characteristics of oxygenated volatile organic compounds (OVOCs) from fresh emissions remains limited. In this study, gaseous organic compounds in fresh smokes from burning typical Chinese crop straws and woods are measured using an iodide time‐of‐flight chemical ionization mass spectrometer. Approximately 750 molecular formulas are identified, with CHO compounds containing carbon, hydrogen and oxygen atoms accounting for 77%–95% of the total. C1–C3 organic acids and dicarboxylic acids dominate the total CHO signal intensities by 27%–48%, while well‐known molecular markers of biomass burning, such as monosaccharide, guaiacol and syringol derivatives, contribute 7%–17%. Notably, crop straw and wood burning emit a higher abundance of guaiacol than syringol derivatives by a factor of 5. Additionally, a variety of nitrogen‐containing compounds (mainly in the CHON group) is identified, including isocyanate, amide, amino acids, and pyridine. The mass spectral profiles of organic compounds are largely similar between crop straw and wood burning fuels, although wood burning produces higher contributions of compounds with carbon atoms numbers >10. The saturation concentrations of organic compounds are estimated using molecular formula‐based volatility parameterization, revealing that semi‐volatile and intermediate VOCs (S/intermediate volatility organic compounds (IVOCs)) predominate smoke releases by 35%–60% and 20%–43%, respectively, with only a small fraction of low‐volatility compounds. Given the widespread nature of biomass burning in winter China, our results may have significant implications for interpreting secondary organic aerosol formation through gas‐particle partitioning or aqueous‐phase reactions.

The Influence of Process-Oriented Guided Inquiry Learning on Eleventh Grade Students’ Chemical Literacy

This study is driven by Indonesia’s low scientific literacy, as indicated by its PISA score. The deficiency in chemical literacy is attributed to the ineffective and limited application of learning models. Its objective is to assess the impact of the Process-Oriented Guided Inquiry Learning (POGIL) model on students’ chemical literacy regarding salt hydrolysis. Conducted in May 2023 at a public high school in Jakarta, the study employed a quasi-experimental design, randomly assigning two sample classes, XI MIPA-1 as the experimental group and XI MIPA-3 as the control group, using the flipping coin method. Each class comprised 36 students. The chemical literacy assessment utilized multiple-choice tests, and data analysis was performed via t-test. The findings demonstrated that POGIL positively influenced students’ chemical literacy in salt hydrolysis among grade 11 students, suggesting its effectiveness in enhancing chemical literacy. Consequently, it is suggested that educators adopt the POGIL model to improve students’ chemistry literacy across various chemistry topics based on these results.

SCALE FORMATION IN THE OIL AND GAS INDUSTRY AND THE TRANSITION TOWARDS «GREEN» INHIBITORS

Hydrocarbon production in oil field conditions invariably involves the joint production of significant amounts of water. Mineral salts of various compositions can precipitate from produced water under certain conditions. In the oil and gas industry, the deposition of mineral salts on the surface and underground production equipment can cause various problems, such as deterioration of reservoir properties, reduced production and premature failure of well equipment. Scale deposition can also lead to pump malfunctions, reduced efficiency of heat exchangers, reduced quality of commercial products and increased corrosion processes. Salt deposits lead to expensive restoration work, downtime in well operations and, ultimately, to an increase in the cost of produced hydrocarbons.As a result of the geochemical processes between the injected water and the formation water and the formation rock, as well as the complex composition of the formation fluids, controlling the formation of inorganic scales becomes a challenge. In the oil and gas industry, carbonate (calcium), sulfide (iron) and sulfate (calcium, barium, strontium) deposits are most often encountered. The formation of scale deposits depends on several factors, which include, but are not limited to, temperature, pressure, solution saturation and hydrodynamic flow characteristics.There are many approaches to managing scale deposits, but the most common currently is the use of chemical reagents – scale inhibitors. Traditional scale inhibitors contain phosphorus- and nitrogen-based chemicals as their active base, which can be harmful to the environment and human health. In this regard, in the world practice of oilfield chemistry, the direction of «green» chemistry is actively developing – reagents that can effectively prevent the formation of mineral salts with minimal negative impact on the environment and humans.This review discusses various scale types, methods for their removal, scale inhibitors of various natures and the mechanism of their work. Attention is also paid to «green» inhibitors and their development.

Air-Stable Cobalt(III) and Chromium(III) Complexes as Single-Component Catalysts for the Activation of Carbon Dioxide and Epoxides.

Cobalt(III) and chromium(III) salophen chloride complexes were synthesized and tested for the cycloaddition of carbon dioxide (CO2) with epoxides to obtain cyclic carbonates. The cat1, cat2, cat4, and cat5 complexes presented high catalytic activity without cocatalysts and are solvent-free at 100 °C, 8 bar, and 9 h. At these conditions, the terminal epoxides (1a-1k) were successfully converted into the corresponding cyclic carbonates with a maximum conversion of ∼99%. Moreover, cat5 was highlighted due to its capability of opening internal epoxides such as limonene oxide (1l) with a 36% conversion to limonene carbonate (2l), and from cyclohexene oxide (1m), cyclic trans-cyclohexene carbonate (2m) and poly(cyclohexene carbonate) were obtained with 15% and 85% selectivity, respectively. A study of the coupling reaction mechanism was proposed with the aid of electrospray ionization mass spectrometry (ESI-MS) analysis, confirming the single-component behavior of the complexes through their ionization due to epoxide coordination. In addition, crystallographic analysis of cat1 single crystals grown in a saturated solution of pyridine helped to demonstrate that the substitution of chloride ion by pyridine ligands to form an octahedral coordination occurs (Py-cat1), supporting the proposed mechanism. Also, a recyclability study was performed for cat5, and a total turnover number of 952 was obtained with only minor losses in catalytic activity after five cycles.

ТЕХНОЛОГИЯ ЗАМКНУТОГО ЦИКЛА ПОЛУЧЕНИЯ СТРОИТЕЛЬНОГО ГИПСА ИЗ ОТХОДА ЭНЕРГЕТИКИ И ДЫМОВЫХ ГАЗОВ ТЕПЛОВОЙ ЭЛЕКТРОСТАНЦИИ

A closed-cycle technology for building gypsum producing using energy waste and flue gases of thermal power plants has been developed. The technology is based on an absorption method for purifying gas emissions from industrial enterprises from sulfur dioxide SO2 using a suspension of carbonate sludge and obtaining a finished product – gypsum dihydrate. The commercial gypsum is obtained by using a suspension of carbonate sludge as a reagent. The suspension is formed at the stage of preliminary purification of natural water during coagulation and liming. Coagulation is carried out with ferrous sulfate heptate FeSO4×7H2O, liming – with a saturated solution of lime milk Ca(OH)2. As a result of combining the two processes, a suspension of a certain chemical composition is formed. The chemical composition of the sludge and its technological characteristics are presented. The main substance in the chemical composition is calcium carbonate CaCO3, which allows using a sludge suspension in the chemical reaction of the interaction of flue gases from thermal power plants with the formation of building gypsum. An absorber with a fluidized nozzle has been selected and designed to purify gas emissions from wet suspensions and produce commercial dihydrate gypsum. Hollow or solid hydrophobic polyethylene balls were selected as nozzles to reduce the adhesion of sludge suspension particles to their surface. A technological scheme is presented for purifying flue gases from sulfur dioxide to obtain the finished product – building gypsum. The scheme includes the proposed adsorber, sludge suspension tank, hydrocyclone and filter press. The cost of the resulting commercial building gypsum was calculated, which amounted to 15 rub./year, the payback period was 3,5 years. The prevented environmental harm from soil and land degradation from the introduction of this technology at thermal power plants was calculated by reducing the emission of sulfur dioxide into the air, which amounted to about 1 mil. rub./year.

Systematic Literature Review: Analysis of Misconception Problems and Diagnostic Instruments for Learning Chemistry

This research aims to analyze research trends in Chemical misconceptions in chemistry learning and diagnostic instruments used. The research method used in this research is a systematic literature review (SLR). The database obtained was 16 articles selected from the Scopus and Google Scholar databases with Publish or Perish (PoP). The results of the research found were the majority of students experienced misconceptions in learning chemistry caused by errors in preconceptions and abstract thinking concepts in the material, the method used to analyze the misconceptions found was a two-level, three-level, four-level diagnostic instrument, multiple choice, and semi-open tests and The misconceptions found in chemistry materials are acid-base, reaction rate, chemical equilibrium, chemical bonding, salt hydrolysis, and buffer solution.

Robust and stable organic sulfonate sodium salt-coated superhydrophilic mesh for ultra-fast gravity-drive oil-water separation

Due to its special wetting behavior and high selectivity, super-wetting mesh is considered as an ideal candidate material for efficient separation of water/oil mixture. However, the oil-water separation mesh suffers from the problems of poor stability and durability, leading to the failure of the separation. In this paper, a robust and stable superhydrophobic/superhydrophilic copper mesh had been successfully prepared by decorating the copper mesh via the chemical grafting of the 3-thiol-propyl trimethoxysilane (KH590) and the subsequent reaction with 2-acrylamide-2-methylpropane-1-sulfonate sodium (AMPS). It showed that the KH590 condensation compound was tightly coated on the surface and the superhydrophobic copper mesh (SUCM) possessed excellent superhydrophobicity towards various liquid droplets with a WCA of higher 150° and a sliding angle lower 5°, while the superhydrophilic copper mesh (SICM) had promising anti-oil pollution property with WCA near 0°. The SUCM and SICM also had excellent acid and alkali resistance. The obtained SICM had preeminent separation efficiency higher 99% and extremely high permeability flux of 33,441 L·m−²·h−¹ for gravity-driven toluene-water separation, and possessed excellent recyclability even after 20 cycles. Moreover, the SICM could be used to separate the oil-water mixture of aqueous solution with different pH (pH=5/7/8) and aqueous sodium chloride solution with different concentrations (5%/25%/50%/saturated aqueous sodium chloride solution). In addition, the SICM had outstanding anti-abrasion mechanical stability. This work provided a simple and effective method for the preparation of special wettability materials with excellent acid/alkali resistance and mechanical stability, and promoted the practical application of oil/water separation mesh.

Maximizing the Reliability and Precision of Measures of Prefrontal Cortical Oxygenation Using Frequency-Domain Near-Infrared Spectroscopy.

Frequency-domain near-infrared spectroscopy (FD-NIRS) has been used for non-invasive assessment of cortical oxygenation since the late 1990s. However, there is limited research demonstrating clinical validity and general reproducibility. To address this limitation, recording duration for adequate validity and within- and between-day reproducibility of prefrontal cortical oxygenation was evaluated. To assess validity, a reverse analysis of 10-min-long measurements (n = 52) at different recording durations (1-10-min) was quantified via coefficients of variation and Bland-Altman plots. To assess within- and between-day within-subject reproducibility, participants (n = 15) completed 2-min measurements twice a day (morning/afternoon) for five consecutive days. While 1-min recordings demonstrated sufficient validity for the assessment of oxygen saturation (StO2) and total hemoglobin concentration (THb), recordings ≥4 min revealed greater clinical utility for oxy- (HbO) and deoxyhemoglobin (HHb) concentration. Females had lower StO2, THb, HbO, and HHb values than males, but variability was approximately equal between sexes. Intraclass correlation coefficients ranged from 0.50-0.96. The minimal detectable change for StO2 was 1.15% (95% CI: 0.336-1.96%) and 3.12 µM for THb (95% CI: 0.915-5.33 µM) for females and 2.75% (95%CI: 0.807-4.70%) for StO2 and 5.51 µM (95%CI: 1.62-9.42 µM) for THb in males. Overall, FD-NIRS demonstrated good levels of between-day reliability. These findings support the application of FD-NIRS in field-based settings and indicate a recording duration of 1 min allows for valid measures; however, data recordings of ≥4 min are recommended when feasible.

Study of the influence of synthesised zeolite as a self-healing for hardened cementing materials

ABSTRACT The impact of incorporating synthesized zeolite on Portland cement with different ratios was analyzed to enhance the healing effeciency of pre-cracked hardened matrix. The pre-cracked hardened specimens was subjected to treatment through immersion in tap water or a saturated lime solution, with the objective of enhancing the effectiveness of the healing process. These matrices represent the most frequently used environments suitable for crack healing. Given that water is a crucial component for cement hydration, saturated lime can alternatively be applied on cracks via spraying to facilitate the ability of heaing thr cracks. The outcomes demonstrated the effectiveness of repairing the pre-cracked structure in both conditions, while the fully saturated lime possesses a higher potential in mending the cracks, as evident from visual observation and petrographicanalysis. Additionally, Fourier Transform Infrared Spectroscopy revealed the incorporation of synthesized zeolite into the structure resulted in an enhancement of the intensity of the formed binder, which interm positively influenced its healing ability. The highest compressive strength was observed in specimens with 4% zeolite addition immersed in tap water, reaching 89 MPa. Furthermore, the compressive strength increased to 116 and 157 MPa with 4% and 6% zeolite addition, respectively, in the fully saturated lime environment.

Damage recovery stages revisited: Thermal evolution of non-saturated and saturated displacement damage in heavy-ion irradiated tungsten

Establishing the correlation between damage recovery and temperature in nuclear materials is vital to understanding material property degradation. Among the handful of topics related, one long-standing concern is the differences in damage recovery caused by different initial defect concentrations, with respect to ranges below and beyond the damage saturation limit. In this study, the temperature dependence of damage recovery has been comprehensively elucidated for pure tungsten, irradiated with 6 MeV copper ions at room temperature (RT), up to 0.05 dpa (non-saturated damage, n-SD) and 0.6 dpa (saturated damage, SD), and followed by isochronal annealing. Coupled transmission electron microscopy and Doppler broadening positron annihilation spectroscopy characterizations provided a full-probe-range picture of defect evolution. The varied initial defect concentrations caused retaining differences in damage recovery, but no substantial influence on temperature-dependent defect evolution. Moderate and dramatic damage recovery were identified below 973 K and above 1123 K in n-SD and SD tungsten, respectively. Most strikingly, nano-sized voids were confirmed at 473 K in both samples. Annealing at 1873 K saw the complete removal of defects in n-SD tungsten, but survival of a few dislocations via void pinning in SD tungsten. Full damage recovery in SD tungsten was projected to be ∼2000 K. The current revisit of damage recovery stages demonstrated the significance of encompassing scenarios of non-saturated and saturated defect concentrations. Accordingly, four damage recovery stages were redefined for heavy-ion irradiated tungsten, namely stage I (20 K–RT), stage II (RT–653 K), stage III (653–1123 K), and stage IV (1123–2000 K).

Lagrangian dynamics of the spring zooplankton community in a large river

Zooplankton may represent a considerable part of plankton in large rivers, but little is known about the factors that control it. We hypothesized that (1) significant longitudinal increase of zooplankton abundance, biomass, taxonomic richness, and diversity will occur along a free-flowing river section; (2) the residence time of water is more important for zooplankton population growth than environmental variables such as water temperature, oxygen saturation, and food concentration; and (3) the influence of tributaries on the longitudinal dynamics of zooplankton is insignificant or only has a local effect. A Lagrangian survey was applied in the free-flowing section of the River Elbe (Germany) in spring 2022. The abundances and biomass of the dominant rotifers as well as of cladocerans and copepods increased significantly downstream due to the population growth of zooplankton. The water residence time was the most important factor for zooplankton increment. One of the tributaries increased zooplankton abundance and biomass in the River Elbe, while other tributaries did not but the introduction of new species increased taxonomic richness and decreased the evenness of zooplankton in the main river so that diversity remained nearly constant.