Salt Water Research Articles

Developing an efficient explainable artificial intelligence approach for accurate reverse osmosis desalination plant performance prediction: application of SHAP analysis

In recent decades, securing drinkable water sources has become a pressing concern for populations in various regions worldwide. Therefore, to address the growing need for potable water, contemporary water purification technologies can be employed to convert saline sources into drinkable supplies. Therefore, the prediction of important parameters of desalination plants is a key task for designing and implementing these facilities. In this regard, artificial intelligence techniques have proven to be powerful assets in this field. These methods offer an expedited and effective means of estimating effective parameters, thus catalyzing their implementation in real-world scenarios. In this study, the predictive accuracy of six different machine learning models, including Natural Gradient-based Boosting (NGBoost), Adaptive Boosting (AdaBoost), Categorical Boosting (CatBoost), Support vector regression (SVR), Gaussian Process Regression (GPR), and Extremely Randomized Tree (ERT) was evaluated for modelling the parameter of permeate flow as a key element in system efficiency, energy consumption, and water quality using six various input combinations of feed water salt concentration, condenser inlet temperature, feed flow rate, and evaporator inlet temperature. The next phase of this research employed the SHAP interpretability method to illustrate the impact of individual variables on the model's output. Moreover, the predictive performance of the developed frameworks was evaluated using a set of five dependable statistical measures: RMSE, NS, MAE, MAPE and R 2. These indicators were utilized to provide a robust means of gauging the precision of the model's forecasts. A comparative analysis of the outcomes, as measured by the RMSE criteria, revealed that the SVR technique (RMSE = 0.125 L/(h·m2)) exhibited superior performance compared to NGBoost (RMSE = 0.163 L/(h·m2)), AdaBoost (RMSE = 0.219 L/(h·m2)), CatBoost (RMSE = 0.149 L/(h·m2)), GPR (RMSE = 0.156 L/(h·m2)), and ERT (RMSE = 0.167 L/(h·m2)) methodologies in predicting permeate flow rates. The modelling outcomes obtained during the evaluation stage demonstrated the efficacy of the SVR algorithm in enhancing the precision of permeate flow forecasts, utilizing relevant input variables.

Mechanistic Simulation of Salt‐Affected Soil‐Plant‐Atmosphere Continuum Dynamics in Seasonally Frozen Regions

AbstractThe salt‐affected Soil‐Plant‐Atmosphere Continuum (SPAC) is a dynamic, interactive system that is particularly complex in seasonally frozen regions where salt transport, precipitation‐dissolution, and soil freeze‐thaw processes play crucial, interrelated roles. Understanding these coupled processes and representing them with mathematical models is critical for effective management of SPAC systems. This study presents a new mechanistic approach and an improved model that integrates a chemical equilibrium module within a mechanistic‐based transport computational module (modified SHAW model). The chemical equilibrium module determines salt precipitation‐dissolution using thermodynamic theory and explains the effects of efflorescence and subflorescence on system dynamics. The model enables simultaneous solutions for heat, water, and salt transport with chemical equilibrium throughout non‐freezing and freezing seasons, as well as plant growth dynamics. Assessment of the model using laboratory experiments and field studies showed good performance, with coefficient of determination values exceeding 0.65 for simulated and measured evaporation rate, leaf area index, soil water content, salt content, and temperature. Furthermore, a comparison between simulation results considering and neglecting the impact of salt precipitation‐dissolution highlights potential inaccuracies in soil heat‐water‐salt dynamics and plant water use resulting from the omission of this process in mechanistic models.

Influence of the stratification parameters on the wake field of an underwater vehicle in a two-layer stratified flow

Because the ocean exhibits different stratification states in different seasons and regions, the effect of different stratification parameters on a submarine wake must be studied. In particular, to investigate such effect in a two-layer stratified flow, this study established a computational fluid dynamics (CFD) model based on the URANS equations, shear-stress transport (SST) k-ω turbulence model, and Eulerian multiphase flow model. The volume of fluid (VOF) method was adopted to implement the free-surface capture method. The working conditions of the SUBOFF model under an infinite diving depth and near the free surface were compared with those of the experiments, and the convergence of the time step and grid number under stratified flow conditions was verified. These validation steps proved the feasibility of the CFD method. Finally, the effects of the stratification parameters on the free surface waves, internal waves, and turbulent kinetic energy behind the vehicle were observed by varying the stratification parameters to achieve different working conditions. The results show that when an underwater vehicle sails in a two-layer stratified flow, the interstratified density ratio and depth of the internal wave surface affect its wake field. When the underwater vehicle sails in the water layer, with an increase in the interstratified density ratio, the free-surface roughness increases and the turbulent kinetic energy decreases. When the underwater vehicle sails in the salt water layer, the result is just the opposite.

On the printability of high-density polyethylene (HDPE) reinforced with long glass and short carbon fibres

Purpose This research is about the possibilities of using high-density polyethylene (HDPE)-based composites consisting of long glass and short carbon fibres because HDPE is one of the more preferred thermoplastics day by day due to its sustainability, cost-effectiveness and availability in the relevant markets. HDPE has become an increasingly preferred material in the marine industry in recent years due to its high resistance to marine environmental conditions (high resistance to UV, surface-fouling marine organisms and corrosive effects of salty and low-pH water). In the highly competitive boat building industry, additive manufacturing offers new opportunities such as rapid prototyping and design freedom. This study aims to investigate the possibilities of using a material suitable for the marine environment and an additive manufacturing (AM) method offering new possibilities, especially for small craft with complex forms. Design/methodology/approach A total of six new HDPE-based composites consisting of long glass and short carbon fibres at 10, 15 and 20% by weight have been proposed for the first time in this study for the use in boat building industry, proposing the application of these new composite materials with AM method, which the industry is not yet fully adopted, is also an innovative aspect of the study. The performances of the materials in AM’s material extrusion (MEX) method were evaluated using the results obtained from mechanical (tensile, compression, shear and impact) and thermal (melt flow index [MFI], thermogravimetric analysis [TGA] and thermomechanical analysis [TMA]) tests. In addition, the structure of the composites was examined with scanning electron microscopy and micro computed tomography visually, and the rheological properties of the composites were also determined by the related tests. As an industrial case study, a ship propeller was manufactured from the composites produced with CF15, which was thought to give the best performance in marine use, and this propeller was tested under water flow. Findings It is evaluated that the composites proposed in this study can be used in marine industry in line with the analyses and test results. The performance of the propeller produced as a case application also confirms this view. The printability of HDPE-based composites, reinforced by both glass and carbon fibre, is much better than that of pure HDPE, and the composites are suitable for use AM’s MEX method in boat building industry. As the fibre contents in the proposed composites increase, the strength values increase and the impact resistance and hardness decrease. The CF15 composite, which meets each of those mechanical and physical values at an average level, is a recommended option for marine applications. Originality/value This study has two basic originalities: (1) On the basis of HDPE, which is widely used in the marine industry, to produce composites that will overcome the deficiencies of this material in practice and to present them to relevant industry by improving their properties; (2) at the same time, to discuss for the first time the use of new HDPE-based materials in AM, whose printability has also been improved through composite, to help dissemination of AM technologies in marine industry in general and in the boat building industry in particular.

Numerical Investigation of Thermal Performance Enhancement of Solar Reservoir using Flash Cycle

The main objective of this research is to model a solar reservoir system located in Dehradun, Uttarakhand, India. Solar reservoir acts as both a collector and long-term storage for thermal energy, potentially providing heat for a full year. Using a single input, the latitude angle, solar radiation for the location is calculated. A one-dimensional time-dependent steady-state model is employed to predict the annual temperature behavior within the storage zone of the solar reservoir. The model analyses the temperature range achievable in the lower convection zone (LCZ) of the reservoir. The findings suggest that the LCZ can reach temperatures as high as 80°C. Additionally, the study demonstrates that an increase in feed temperature can improve overall system efficiency. At the end of summer, temperatures as high as 70 °C were observed in the solar pond at a depth of 1.32 m. It reached 26 °C at its lowest point in early April. In an artificial solar pond, salt water is utilised to inhibit convection. There was a 26% concentration of salt NACL at the lake's bottom. The kind and concentration of salt have an impact on the pond's stability. It was determined that 80 g/kg of water is the ideal salt level for the small solar pond. This study demonstrates the potential for maintaining both salinity gradient and thermal performance over an extended period. Future research efforts could benefit from larger-scale experiments that bridge the gap between controlled environments and real-world applications.

Conversion of Abundant Aldoses with Acetylacetone: Unveiling the Mechanism and Improving Control in the Formation of Functionalized Furans Using Lewis Acidic Salts in Water

Conversion of Abundant Aldoses with Acetylacetone: Unveiling the Mechanism and Improving Control in the Formation of Functionalized Furans Using Lewis Acidic Salts in Water

Simultaneous recovery of ammonium sulfate and ice from aqueous solution using eutectic freeze crystallization process

This study investigated the feasibility of eutectic freeze crystallization (EFC) process for ammonium sulfate (AS) salt recovery from 41 wt% AS solution. The EFC experiments were conducted using a 1 L double-jacketed crystallizer coupled with a recirculating chiller under varying freezing time, seed mass and seed size. The EFC process demonstrated successful AS salt recovery and water purification with the highest ice purity attained at 96.28 %. The construction of a binary AS-water phase diagram allowed the determination of the eutectic temperature, which was found to be −19.06 °C at 40 wt% of AS solution. The results indicated that the increase in freezing time enhanced the AS nucleation rate, growth rate, yield and mean product crystal size. The introduction of seeding not only provided well-controlled crystal nucleation and growth during EFC process, but also promoted the formation of larger, well-structured crystals and reduced agglomeration. Overall, the EFC process is a viable and promising option for recovering AS from wastewater, which offers high potential towards achieving zero liquid discharge goal, i.e. a sustainable and efficient approach in managing industrial effluent rich in ammonium and sulfate contaminants.

Molecular dynamics insights into the dynamical behavior of structurally modified water in aqueous deep eutectic solvents (ADES).

Recent studies have demonstrated that the presence of water in deep eutectic solvents (DESs) significantly affects their dynamics, structure, and physical properties. Although the structural changes due to the addition of water are well understood, the microscopic dynamics of these changes have been rarely studied. Here, we performed molecular dynamics simulation of 30% (v/v) (∼0.57 molar fraction) water mixture of DES containing CH3CONH2 and NaSCN/KSCN at various salt fractions to understand the microscopic structure and dynamics of water. The simulated results reveal a heterogeneous environment for water molecules in aqueous DES (ADES), which is influenced by the nature of the cation. The diffusion coefficients of water in ADESs are significantly lower than that in neat water and concentrated aqueous NaSCN/KSCN solution. When Na+ ions are replaced by K+ ions in the ADES system, the diffusion coefficient increases, which is consistent with the measured nuclear magnetic resonance data. Self-dynamic structure factor for water and other simulated dynamic quantities, such as reorientation, hydrogen-bond, and residence time correlation functions, show markedly slower dynamics inside ADES than in the neat water and aqueous salt solution. Moreover, these dynamics become faster when Na+ ions in ADES are replaced by K+ ions. The results suggest that the structural environment of water in Na+-rich ADES is rigid due to the presence of cation-bound water and geometrically constrained water. The medium becomes less rigid as the KSCN fraction increases due to the relatively weaker interaction of K+ ions with water than Na+ ions, which accelerates the dynamical processes.

A Novel Technique in Determining Mud Cake Permeability in SiO2 Nanoparticles and KCl Salt Water Based Drilling Fluid using Deep Learning Algorithm

The permeability of the mud cake formed at the formation-wellbore interface is an important factor in the designing of water-based drilling fluids. This study presents a novel approach to utilizing experimental thixotropic and rheological parameters of polymeric water-based drilling fluids having varying concentrations of SiO2 nanoparticles and KCl salt. A fully connected feed-forward multi-layered neural network, more commonly known as a Multilayer Perceptron (MLP) was developed to predict the mud cake permeability using input parameters such as SiO2 & KCl concentration, differential pressure, temperature, mud cake thickness, API LPLT and HPHT filter loss volume and spurt loss volume. The results suggested that the developed Multilayer Perceptron model effectively determined the mud cake permeability based on the input parameters of the WBDF mentioned above. The model converged on the global minima, minimizing the loss function using the Gradient descent algorithm. A higher Coefficient of Determination (R2) value i.e., 0.8781, and a lesser Root Mean Square Error (RMSE) value i.e., 0.04378 indicates the higher accuracy of the model. Pearson’s Coefficient of Correlation obtained via the heatmap indicates that mud cake permeability is strongly influenced by the differential pressure followed by filter loss volume, spurt loss volume, mud cake thickness, and temperature. Previous similar studies have focused on using machine learning algorithms, this study utilized a robust deep learning algorithm i.e., Multilayer Perceptron (MLP) neural network to simultaneously model the combined effects of SiO2 nanoparticles and KCl salt concentrations on mud cake permeability, offering an unprecedented level of accuracy in predicting key WBDF performance parameters

Geometric optimization to improve the performance of a new design of concentration‐based solar distiller using particle swarm optimization algorithm

AbstractSolar distillers are one of the oldest and simplest technologies for desalinating salt water using solar energy. The main problem is the low freshwater production compared to the amount of energy input from the sun. To overcome this problem, a solar distiller was developed using a parabolic trough concentrator to increase the freshwater yield. The geometry optimization of various parameters of the developed system was also studied using the particle swarm optimization (PSO) algorithm to obtain the optimal design and give the improved freshwater yield. The simulation is carried out based on the algorithm using the climatic condition data of Rabat City, Morocco. Numerical resolution of the energy balance equations was performed using MATLAB code. In terms of flexibility, speed, and global convergence, this method's final results were satisfactory. The maximum optimized freshwater yield using the PSO approach is 12.83 kg/m2 and the maximum optimized energy and exergy efficiency were about 204.7% and 34.3%, respectively. Furthermore, the results showed that the absorber basin accounts for the highest exergy destruction, 88.7% of the total optimized exergy destruction was found from exergy analysis.

Study on Quantitative Assessment of CO2 Leakage Risk Along the Wellbore Under the Geological Storage of the Salt Water Layer

In the process of CO2 geological storage in the salt water layer, CO2 leakage along the wellbore will seriously affect the effective storage of CO2 in the target geological area. To solve this problem, based on the investigation of a large number of failure cases of CO2 storage along the wellbore and failure cases of gas storage wells in the injection stage of the wellbore, the influencing factors of CO2 leakage risk along the wellbore were investigated in detail. Based on the analytic hierarchy process (AHP) and extension theory, 17 basic evaluation indexes were selected from 6 perspectives to establish the evaluation index system of CO2 leakage risk along the wellbore. The established evaluation system was used to evaluate the leakage risk of a CO2 storage well in the X gas field of BZ Block. The results showed that the influencing factors of tubing had the smallest weight, followed by cement sheath, and the influencing factors of casing–cement sheath interface and cement sheath–formation interface had the largest weight, accounting for 23.73% and 34.32%, respectively. The CO2 storage well leakage risk evaluation grade was Ι, with minimal leakage risk. The CO2 storage effect was excellent. The evaluation system comprehensively considers the tubing string, cement sheath, and micro-annulus interface, which can provide a scientific basis for the risk assessment of CO2 leakage along the wellbore under the CO2 geological storage of the salt water layer.

Simulation of water-salt transport and balance in cultivated-wasteland system based on SWAP model in Hetao Irrigation District of China

Water and salt transport among different use type land is important to irrigation management in arid area. In this study, a typical irrigation unit including cultivated land and wasteland in Hetao Irrigation District of China was selected to explore water and salt transport between cultivated land and wasteland system. Soil water-salt dynamics, groundwater depth and salinity were observed within the period of crop growing and autumn irrigation period in 2018 and 2019. Calibrated SWAP model was used to simulate water and salt flux of cultivated land and wasteland during the crop growing period and autumn irrigation period. Furthermore, water-salt transport exchange capacity was calculated between cultivated land and wasteland system in study area. Groundwater was recharged by soil water and soil salt was leached in cultivated land during the crop growing period. Soil water was recharged by groundwater and soil salt was accumulated in saline wasteland during the crop growing period. During the crop growing period, the total leaching of soil salinity was 15.64 t·ha−1 in cultivated land. Soil salt accumulation was 2.03 t·ha−1 in saline wasteland. During the autumn irrigation period, the total leaching of soil salinity was 14.93 t·ha−1 in cultivated land. Total leaching of soil salinity was 1.56 t·ha−1 in saline wasteland. Overall, saline wasteland had an important role to receive salt from cultivated land and maintain salt dynamic balance in arid irrigation area with shallow groundwater.

Zwitterion Modification in Desalination Membrane for Rejecting Salt and Salt Ions in Brackish Water – A Mini Review

ABSTRACTDesalination membrane using zwitterion modification provides a significant opportunity to enhance excellent properties for rejecting salt and salt ions. The outstanding properties are designed by positive and negative charges attached to the membrane surface, including water permeability, salt permeability, fouling, and hydrophilicity of the membrane surface. The hydrophilic membrane, which is mentioned as one of the types of desalination membrane, presents the ability to repel salt and salt ions and pass the water. The modification of hydrophilic membranes is also affected by several factors, including water permeability, salt permeability, fouling of membrane surfaces, crossflow velocity, transmembrane pressure, and temperature. Regarding membrane modification, zwitterion has been applied for several ranges, such as the hemodialysis process, live cell imaging, antibacterial surfaces, and wound dressing. However, using a zwitterion modification membrane for desalinating water containing salt content, including brackish water, has yet to be developed. In addition, literature reviews related to polymer membranes for brackish water desalination have never been comprehensively documented. Thus, this review article addresses the zwitterion modification for desalination membranes, which can reject salt and salt ions in brackish water. Furthermore, the mechanism of zwitterion modification for desalination membranes has been presented. Finally, the challenge of zwitterion modification for desalination membranes has been evaluated to inspire insight for future studies.

Perylene diimide-derived supramolecules-modified graphene sponge as a high-efficiency solar steam generator

Generating steam using solar energy appears to be an effective approach to obtaining clean water, especially from salty water and wastewater, since the sun is a natural and constant source. Compared to many methods, studies in solar steam generation have accelerated due to being highly efficient, sustainable, and low-cost. Graphene sponges (GrSs), possessing structural flexibility and effective photothermal activity, are widely used for this purpose. However, the hydrophobic character of these materials limits their effectiveness in solar steam generators. At this point, we prepared perylene diimide-derived supramolecules (PDI) modified three-dimensional (3D) gradient hydrophobic GrS (PDI/GGrS) as the highly efficient solar thermal converter for the generation of clean water. PDI allowed us to achieve perfect absorption of broad-band sunlight and GGrS facilitated water transport through channels of sponge structure. As a result, PDI/GGrS has achieved a high water evaporation rate of 3.5 kg h−1 m−2 with a superior solar thermal conversion efficiency of up to 90 %. This study can provide new possibilities for harvesting solar energy by producing clean water from seawater, wastewater, and even acidic/alkali solutions.

Limiting regimes of turbulent horizontal convection. Part 2. Large Prandtl numbers

Horizontal convection at large Rayleigh and Prandtl numbers is studied experimentally in a regime up to seven orders of magnitude larger in terms of Rayleigh numbers than previously achieved. To reach Rayleigh numbers up to $10^{17}$ , the horizontal density gradient is generated using differential solutal convection by a differential input of salt and fresh water controlled by diffusion in a novel experiment in which the zero-net mass flux of water is ensured through permeable membranes. This set-up allows us to accurately measure the Nusselt number in solutal convection by carefully controlling the amount of salt water exchanged through the membranes. Combined measurements of density and velocity across more than five orders of magnitude in Rayleigh numbers show that the flow transitions from the Beardsley & Festa (J. Phys. Oceanogr., vol. 2, issue 4, 1972, pp. 444–455), Shishkina & Wagner (Phys. Rev. Lett., vol. 116, issue 2, 2016, 024302) regime to the Chiu-Webster et al. (J. Fluid Mech., vol. 611, 2008, pp. 395–426) regime and frames the present results within the scope of Shishkina et al. (Geophys. Res. Lett., vol. 43, issue 3, 2016, pp. 1219–1225), and the theory of Part 1 (Passaggia & Scotti, vol. 997, 2024, J. Fluid Mech., A5). In particular, we show that, even for large Prandtl numbers, the circulation eventually clusters underneath the forcing horizontal boundary, leaving a stratified core without motion. Finally, the previous regime diagrams (Hughes & Griffiths, Annu. Rev. Fluid Mech., vol. 40, 2008, pp. 185–208; Shishkina et al., Geophys. Res. Lett., vol. 43, issue 3, 2016, pp. 1219–1225) are extended by combining the present results at high Prandtl numbers, the results at low Prandtl numbers of Part 1, together with previous results from the literature. This work sets a new picture of the transition landscape of horizontal convection over six orders of magnitude in Prandtl number and sixteen orders of magnitude in Rayleigh number.

Plasma‐Enhanced Magnetron Sputtering: A Novel Approach for Biofunctional Metal Nanoparticle Coatings on Reverse Osmosis Composite Membranes

AbstractReverse osmosis (RO) is the most common method for treating salt and brackish water. As a membrane‐driven process, a key challenge for RO systems is their susceptibility to scaling and biofouling. To address these issues, functional coatings utilizing metal nanoparticles (MNPs) are developed. In this study, silver, gold, and copper nanoparticles are applied onto thin‐film composite (TFC) membranes using plasma‐enhanced magnetron sputtering. The elemental composition, surface morphology, and hydrophilicity of the coatings are analyzed using X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurements. The antimicrobial properties and the filtration efficiency of the coated membranes are assessed through application‐specific experimental setups. Silver and copper nanoparticles exhibit superior antimicrobial properties, reducing microorganism adhesion by a factor of 103 compared to uncoated membranes. Under appropriate coating conditions, no deterioration in filtration performance is observed. Enhancing the adhesion of MNPs is necessary for achieving sustained release of metal ions.

Improvement of Salt Leaching Efficiency and Water Content of Soil through Irrigation with Electro-Magnetized Saline Water

While the advantageous effects of using magnetic and electromagnetic treatment (ET) of brackish and saline waters on soil salinity reduction in the root zone were largely reported, more studies are needed to answer questions about the soil salt leaching efficiency and the effect of the duration of the exposure to ET. For this aim, pot experiments were conducted using an Aqua-4DR physical water treatment device. The first experiment included two trials. The first trial considered five concentrations: C0:1.0; C1:4.5; C2:9; C3:13.5; and C4:18 dS m−1. The results revealed that the volume and the salt concentrations of the drained waters were significantly higher under irrigation with ET saline waters than those provided by untreated waters. The drained fraction of water varied from 20 to 26% under irrigation with untreated water and increased from 33 to 56% under irrigation with electro-magnetized water, indicating an improvement in the salt leaching. The second trial was carried out with different irrigation doses. The results showed that the higher the dose, the more obvious and significant the ET effect. The different treatment durations of water exposure revealed that the volume and salinity of drained water significantly increase as the ET duration increases. An increase in the ET duration also induces an increase in the soil water content of around 2.5%. Based on the experimental findings, we may conclude that the ET of saline water can reduce the adverse effect of salinity on the top soil, but these leached salts are carried away in depth and there is no concentration limit of water to the effect of the ET.

Inovasi Bitterballen dengan Vegetable Oatmeal Bitterballen untuk Menambah Variasi Menu di Dapoer Marclip

Bitterballen is a traditional Dutch snack shaped like a ball, primarily made from flour and milk. Classic bitterballen usually contain minced beef and cheese. Its crispy exterior and soft interior make it a popular snack. In this study, the author utilizes vegetables and oatmeal to create a delicious and healthy version of bitterballen. The processing of Vegetable Oatmeal Bitterballen is in collaboration with Dapoer Marclip. The purpose of developing this product is to assess the panelists' preferences regarding appearance, color, aroma, texture, and taste, as well as to establish recipe standards. This research employs a research and development method. Data collection was conducted through organoleptic tests involving 25 participants, including lecturers, industry representatives, and consumers. Based on the results from four trials, it can be concluded that the preference levels in the main test were as follows: appearance—44% very much liked, 56% liked; color—76% very much liked, 24% liked; aroma—56% very much liked, 44% liked; texture—68% very much liked, 32% liked; taste—80% very much liked, 20% liked. Thus, it is stated that this product is well-liked and accepted by the panelists. The appropriate standard recipe formula is: 105g flour, 20g butter, 40g onion, 7g garlic, 100g spinach, 50g carrots, 85g corn, 40g mozzarella, 80g rolled oats, 1 egg, 150ml UHT milk, 120ml water, 5g MSG, 3g pepper, and 4g salt. The author suggests that future researchers consider alternative snack recipes using vegetables and appealing colors.

Cellular Phosphate Sensing and Anion Binding by an Azacrown-Calixpyrrole Hybrid.

A hybrid receptor-sensor for anions originating from the merging of positively charged ammonium moieties for electrostatic attraction/stronger binding of azacrowns with directionality of calixpyrrole hydrogen bond donors for selectivity is investigated. As demonstrated this hybrid receptor-sensor shows a remarkable selectivity for orthophosphate even in the presence of other phosphates and anions found in cellular materials (Kassoc H2PO4 ->H2P2O7 2->AMP-≫ADP2- or ATP3- over halides, nitrate, or hydrogen sulfate; all Na+ salts in water) but also cellular polyphosphate or phospholipids. This selectivity is harnessed in a real-time monitoring of cell lysis by lysozyme, which releases orthophosphate and other phosphates and anions from the cells. This sensitive (LOD 0.4 μM) fluorescence-based microscale method compares favorably with the state-of-the-art techniques but can easily be practiced in a high-throughput screening (HTS) manner. The anion binding and selectivity in aqueous solutions were investigated by NMR and put in context with phosphate binding of the parent calix[4]pyrrole. The microscopic understanding of anion binding by the hybrid receptor was then obtained from a combination of density functional theory (DFT), classical molecular dynamics (MD) with explicit water solvation, and ab initio MD (AIMD) simulations. Correlating the NMR and fluorescence binding data with studies of solvation of the receptor, phosphate anion, and the resulting complex confirms the binding is largely driven by entropic component (TΔS) associated with receptor and anion desolvation.

Treatment of turbine blades in electric power stations by adding nano oxides to the matrix material (Al80-Ni20)

Abstract A base material of Al80-Ni20 was used and mixed with variable proportions of Nano chromium oxide (Cr2O3) at percentages of 2, 4, 6, 8 and 10%, as well as with Nano magnesium oxide (MgO) at percentages of 2, 4, 6, 8 and 10%. These mixtures were then applied using the thermal spraying method with a flame. This particular method is commonly used for repairing cracks and protecting turbine blades in electric power stations from external corrosion. However, it is important to note that this method may face challenges when exposed to high-temperature water vapour, salts and other working conditions experienced by turbine blades. Samples were prepared by thermally sintering the coating at 1000 °C for two hours. Various measurements were performed to assess the structural properties using a scanning electron microscope (SEM), as well as other physical tests such as porosity, hardness, adhesion strength and frictional wear. The SEM analysis revealed that the presence of 10% Cr2O3 resulted in a surface that was uniformly free from external defects, whereas the addition of MgO led to a less homogeneous surface. The physical data obtained indicated a preference for Cr2O3, as evidenced by the porosity results (4.5%) observed after thermal sintering at 10%, as well as the hardness (193 HV), adhesion strength (40 MPa) and wear (2.90 × 10−5 g cm−1) measurements. Moreover, the analyses of the properties of MgO under the same conditions included porosity (10%), hardness (155 HV), adhesion strength (35 MPa) and wear (5.50 × 10−5 g cm−1).