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Flux, able to improve the ash fusibility, usually contains catalytic metal compounds. Unfortunately, the quantitative analysis of synergistic catalysis effects between different fluxing agents on coal gasification has not been investigated thoroughly. In this study, the effect of the kinds and content of Na/Ca-based fluxes on char gasification was investigated in thermogravimetry analyzer (TGA). The synergistic catalysis effects and mechanism between the two kinds of fluxes were also studied. Finally, based on the TGA tests, the kinetics models for char gasification with flux addition were developed. The results showed that all the four Na-based fluxes could increase the char reactivity. Na2CO3, which afforded the best activity, could increase the reactivity by 5.3 times when the content was 5%. The five Ca-based fluxes had a weaker catalysis effect compared with Na-based fluxes. CaCl2, exhibiting the best activity among the five Ca-based fluxes, could increase the reactivity by 2.3 times when the content was 5%. For composite fluxes, Na2CO3–CaO and Na2CO3–CaCO3 had a remarkable synergistic effect, whereas others had less effect. Na2CO3 could inhibit the aggregation of Ca, which might cause the synergistic effects between Na and Ca fluxes. The random pore model was more suitable to describe the catalytic gasification process.

The contribution of the aquatic water body to the tritium (3H) flux in the atmosphere near the discharge point of Kakrapar Gujarat Site has been assessed by collecting and analyzing the 3H activity in the air moisture and in the water sample near the aquatic discharge point. The observed air 3H activity near the discharge point was in the range of ≤0.20–19.8 Bq/m3, whereas the predicted 3H activity at the same location due to the atmospheric release through stack varied from 0.10 to 0.15 Bq/m3. The range of water 3H activity through the discharge point varied from ≤10 to 3482 Bq/l. The 3H flux (water to air transfer) was estimated and found to be in the range of ≤5.90E+01 – 2.05E+04 Bq/m2/s. The observation shows that during radioactive aquatic releases, there is an increase in the 3H activity levels in the water vapor near the aquatic discharge point. The observed 3H activity levels in air samples were extremely low to contribute any additional dose to the member of the public as compared to the public dose obtained from natural background sources.

In this research the membranes distillation were used to remove calcium ions from heavy sewers at dairy plants in Iraq. This method is easy to operate, easy to manage and has many economic benefits. A chemical treatment was carried out on it using alum as a coagulant, different tests achieved samples before and after passing MD, according to APHA, AWWA, WEF. The results showed that obtained in water treatment trust that has been manufactured and edited according to the characteristics of the water waste the interests of the dairy capacity of this method to remove the calcium ion to a certain extent it is when the concentration reaches the inside of this ion to 1428.57 mg per liter, where to start the composition of hydroxides of calcium responsible for pain. The optimal working temperature ranges from 20-22 ° C and the flow is around 0.66 kg.m-2.h-1, here was the result of a layer of plaster that led to clogged membrane and folding and was stopped for washing and cleaning.

Aluminum–Vanadium (AlV) alloy is essential for high-performance titanium material. Calcium fluoride (CaF2) is currently used in AlV production and has inevitable drawbacks in terms of product quality and environmental impact. In order to avoid its potential hazards, lime (CaO) as an alternative flux material in producing AlV alloy has been investigated in laboratory and by industrial trials in the present study. The samples were analyzed by Electron Probe X-ray Micro-analyzer (EPMA) and X-ray Diffraction (XRD), regarding the phases formed and corresponding compositions. A slag with good fluidity can protect inner alloy from being oxidized and also promotes the separation between slag and alloy, with a goal to reduce alloy inclusions in slag to enhance the yield. The results showed that using CaO as flux with appropriate amount greatly improved the yield and quality of the AlV alloy and avoided environmental pollution caused by fluoride evaporations.

Abstract A helical air gap membrane desalination (HAGMD) system is designed in the present study. The condenser is designed as a cylindrical shape with helical fins machined on the outer surface of a hollow copper condenser. A detailed theoretical model, studying heat and mass transfer in the HAGMD module, was developed. The theoretical model for a cylindrical system with fins is developed for the first time and is unique in the MD literature. Experimentation was carried out to examine the behavior of the HAGMD module under diverse design and operating conditions. The effect of cold flow rate, feed flow rate, feed temperature, the height of fins, the number of fins, and the length of the module is determined on the performance of the HAGMD system. Permeate flux and gained output ratio (GOR) were considered as the performance indicators of the system. Results showed that permeate flux increases with cold flow rate, feed temperature, feed flow rate, as well as number of fins, while the increase in height of fins negatively affects the flux. Theoretical model and experimental results are found to be in excellent agreement with only 6.7% of error which shows that the present theoretical model is excellent to predict the performance of any HAGMD system. For similar design parameters, the average flux increased by 135% for the finned HAGMD module, with 35 fins over the one with that only for 1 fin. Maximum experimental distillate flux is found to be 20 kg/m2 hr, and GOR is found to be 0.75.

To gain a better understanding of the geochemical behavior of dissolved manganese (Mn) in the marginal seas with respect to distribution and exchange fluxes, more than 200 water samples were collected in the East China Sea (ECS) in May, August, and October of 2013. The concentration of dissolved Mn in the ECS ranged from 1.1 to 81.5 nM, with a gradual decrease with distance from the shore. Seasonal distribution of dissolved Mn varies significantly in the Changjiang estuary, mainly regulated by freshwater input from the Changjiang (Yangtze River) and redox variations. The ECS continental shelf is an important source of Mn for adjacent waters, and the export of Mn–rich coastal waters had an important effect on its re-distribution and internal cycling. The dynamic variation fluxes of water and dissolved Mn across the 100– and 200–m isobaths in the ECS were calculated with an aid of the Finite−Volume Coastal Ocean Model (FVCOM). The ECS continental shelf exported (5.69 ± 1.14) × 108 mol/yr of Mn into the East/Japan Sea from the Tsushima Strait. The Kuroshio surface waters receive an additional (1.02 ± 3.12) × 108 mol/yr of Mn from the ECS continental shelf through a cross–shelf exchange process, which could potentially affect dissolved Mn in the Northwest Pacific. Our data suggest that off-shelf transport from the ECS continental shelf is essential for understanding the biogeochemical cycles of trace metals in the Northwest Pacific Ocean and the East/Japan Sea.

Abstract The study is aimed to develop a monolithic controlled matrix transdermal patches containing Metoclopramide as a model drug by solvent casting method. Eudragit L100, Polyvinylpyrrolidone K-30, and Methylcellulose were used in different ratios and Polyethylene glycol 400 added as a plasticizer. Resulting patches were evaluated for their physicochemical characters like organoleptic characters, weight variation, folding endurance, thickness, swelling index, flatness, drug content, swelling index, percentage erosion, moisture content, water vapor transmission rate and moisture uptake. Formed patches were also evaluated through Fourier transform spectroscopy (FT-IR), X-ray diffraction (XRD), Differential Scanning calorimetry (DSC) and Scanning Electron Microscopy (SEM). Results of SEM unveiled smooth surface of drug-loaded patches. In-vitro dissolution studies were conducted by using dissolution medium phosphate buffer saline pH 7.4. Effect of natural permeation enhancers was elucidated on two optimized formulations (Z4 and Z9). Different concentrations (5%-10 %) of permeation enhancers i.e. Olive oil, Castor oil and Eucalyptus oil were evaluated on Franz diffusion cell using excised abdominal rat skin. Z4-O2 (Olive oil 10%) had enhanced sustain effect and flux value (310.72) close to the desired flux value. Z4-O2 followed Higuchi release model (R2= 0.9833) with non-fickian diffusion release mechanism (n=0.612).

Excessive consumption of sweets is a risk factor for metabolic syndrome. A major chemical feature of sweets is fructose. Despite strong ties between fructose and disease, the metabolic fate of fructose in mammals remains incompletely understood. Here we use isotope tracing and mass spectrometry to track the fate of glucose and fructose carbons in vivo, finding that dietary fructose is cleared by the small intestine. Clearance requires the fructose-phosphorylating enzyme ketohexokinase. Low doses of fructose are ∼90% cleared by the intestine, with only trace fructose but extensive fructose-derived glucose, lactate, and glycerate found in the portal blood. High doses of fructose (≥1 g/kg) overwhelm intestinal fructose absorption and clearance, resulting in fructose reaching both the liver and colonic microbiota. Intestinal fructose clearance is augmented both by prior exposure to fructose and by feeding. We propose that the small intestine shields the liver from otherwise toxic fructose exposure.

This study investigated the effect of flux type and amounts on recovery behavior of aluminum alloy during the melting process of Al can scrap. The heat treatment was conducted to remove the coating layer on the surface of can scrap at 500°C for 30 min. The molten metal treatment of the scrap was performed at 750°C in a high-frequency induction furnace with different flux types and amounts. It was observed that the optimum condition for recovery of Al alloy was to add about 3 wt.% flux with a salt and MgCl2 mixing ratio of 70:30 during melting process. The mechanical properties of recovered Al alloy were about 254.8 MPa, which is similar to that of the virgin Al5083 alloy.

In submerged arc welding (SAW) of chromium (Cr) containing steels, Cr is usually added to the weld metal from the weld wire, and not from the welding flux. Manufacturing of weld wires of specific compositions is expensive and time consuming and cannot closely match all the desired alloy compositions. Therefore, the weld wire chemistry is usually over matched to the base plate composition. Better matching between the weld metal and base plate is possible if the weld metal incorporates Cr from Cr containing metal powder, instead of sourcing Cr from weld wire of limited Cr content. Because Cr is easily oxidised, the oxygen partial pressure in SAW must be controlled. This work illustrates the control of the oxygen potential at the molten flux-weld pool interface by using aluminium (Al) powder addition. The controlled oxygen potential at the molten flux-weld pool interface ensures increased Cr powder transfer into the weld pool, without interfering with oxygen transfer from the plasma arc to the weld pool. The objective of this work is to use targeted powder additions to better control Cr reactions in SAW to improve Cr metal transfer to the weld metal and maintain an acceptable level of oxygen in the weld metal.

Understanding the behaviour of vortices under nanoscale confinement in superconducting circuits is important for the development of superconducting electronics and quantum technologies. Using numerical simulations based on the Ginzburg–Landau theory for non-homogeneous superconductivity in the presence of magnetic fields, we detail how lateral confinement organises vortices in a long superconducting nanostripe, presenting a phase diagram of vortex configurations as a function of the stripe width and magnetic field. We discuss why the average vortex density is reduced and reveal that confinement influences vortex dynamics in the dissipative regime under sourced electrical current, mapping out transitions between asynchronous and synchronous vortex rows crossing the nanostripe as the current is varied. Synchronous crossings are of particular interest, since they cause single-mode modulations in the voltage drop along the stripe in a high (typically GHz to THz) frequency range. [ABSTRACT FROM AUTHOR]

SUMMARY: Ammonium (NH4+)‐based fertilization efficiently mitigates the adverse effects of nitrogen fertilization on the environment. However, high concentrations of soil NH4+ provoke growth inhibition, partly caused by the reduction of cell enlargement and associated with modifications of cell composition, such as an increase of sugars and a decrease in organic acids. Cell expansion depends largely on the osmotic‐driven enlargement of the vacuole. However, the involvement of subcellular compartmentation in the adaptation of plants to ammonium nutrition has received little attention, until now. To investigate this, tomato (Solanum lycopersicum) plants were cultivated under nitrate and ammonium nutrition and the fourth leaf was harvested at seven developmental stages. The vacuolar expansion was monitored and metabolites and inorganic ion contents, together with intracellular pH, were determined. A data‐constrained model was constructed to estimate subcellular concentrations of major metabolites and ions. It was first validated at the three latter developmental stages by comparison with subcellular concentrations obtained experimentally using non‐aqueous fractionation. Then, the model was used to estimate the subcellular concentrations at the seven developmental stages and the net vacuolar uptake of solutes along the developmental series. Our results showed ammonium nutrition provokes an acidification of the vacuole and a reduction in the flux of solutes into the vacuoles. Overall, analysis of the subcellular compartmentation reveals a mechanism behind leaf growth inhibition under ammonium stress linked to the higher energy cost of vacuole expansion, as a result of alterations in pH, the inhibition of glycolysis routes and the depletion of organic acids. Significance Statement: Ammonium nutrition provoked tomato growth inhibition, partly caused by the reduction of cell enlargement. Combining in vivo pH measurement, non‐aqueous fractionation and mathematical modeling, we report that the decrease in vacuolar pH and organic acid concentrations incurred an increase in the energy cost of solute accumulation in the vacuole, and thus limited cell growth under ammonium nutrition. [ABSTRACT FROM AUTHOR]

In this work, NH4Cl flux-assisted solution combustion synthesis of Eu3+-doped CdSiO3 phosphor has been reported. The prepared phosphor has been characterised using XRD, SEM, FTIR, UV–Vis and PL techniques. The influence of NH4Cl flux on the structural, morphological and photoluminescence (PL) properties has been thoroughly investigated. The PL spectra of 5 mol% Eu3+-doped CdSiO3 nanophosphor monitored at Eu3+ emission wavelength of 613 nm, consists of four broad excitation peaks centred at 362 nm, 381 nm, 393 nm and 414 nm ascribed to Eu3+ ion transitions from its 7F0 ground state energy level to different excited energy states 5H3, 5L7, 5L6 and 5D3, respectively. CdSiO3:Eu3+ samples prepared by using 6 wt% flux showed appreciable improvement in emission intensity in the studied concentration limit. The observed improvement in the orange-red photoluminescence is due to effective substitution of Eu3+ ions in the CdSiO3 lattice. [ABSTRACT FROM AUTHOR]

In this paper, we determine, in the Heisenberg group, the parametric Killing magnetic flux surfaces and their corresponding Killing scalar flux functions. An examples of each are given with a graphic representation in Euclidean space. [ABSTRACT FROM AUTHOR]

Chromium alloying of weld metal is usually accomplished via weld wire. This is done because chromium has a high affinity for oxygen and is therefore not easily transferred across the arc. The formation chromium (VI) is one of the main concerns in welding with chromium containing consumables, especially in open arc processes, and less so in SAW (submerged arc welding). This study investigates the chemical behaviour of chromium in the application of unconstrained metal powders of Al, Cr, Cu and Ti in SAW. The application of aluminium in SAW is used to control the oxygen partial pressure in the process to prevent oxidation of elements of high oxygen affinity, such as chromium. The speciation of chromium was investigated in two-dimensional (2D) and three-dimensional (3D) post-weld slag samples. In the 2D slag samples, the chromium is contained in low concentrations in the oxy-fluoride matrix phase. The 3D samples showed dome structures in which evidence of vapour formation was identified. Chromium presents as distinct chromium spots throughout the oxy-fluoride dome walls, and it is not observed as solute in the oxy-fluoride phase. Chromium presents as chromium-rich Cr-Mn-Mg-O porous particles of less than 20 µm in size, which may agglomerate into larger masses. The calculated thermochemical predominance diagrams show that the Al(l)-Al2O3(s)-AlF(g) equilibrium can maintain the partial oxygen pressure (PO2) at 10−16.5 atmosphere and the partial fluorine pressure (PF2) at 10−11.4 atmosphere at 2500 °C. Under these gas phase conditions in the arc cavity, chromium is present as metallic chromium and may subsequently vaporise as chromium metal and combine with other vaporised elements. [ABSTRACT FROM AUTHOR]

In the present work, two dissimilar metals austenitic AISI 304 and 316 stainless steels were welded with duplex 2205 using semi-automatic bi-directional GMAW setup to appraise the microstructural and mechanical behavior of the welded joints. Three different activated fluxes i.e. SiO2, TiO2 and CrO3 were used to enhance the depth of penetration during joining of different stainless steels grades. Various process parameters such as welding current, voltage, filler wire, gas flow rate and activated flux were varied to observe their influences on joint tensile, bending strength, microhardness and microstructural properties. The experiments were designed using mixed level L18 orthogonal array of Taguchi method. Tensile strength was observed to be considerably dependent on the low gas flow rate, whereas welding current and activated flux influenced the toughness. The most significant effect on the bending strength and toughness was experienced with the use of SiO2 activated flux. [ABSTRACT FROM AUTHOR]

The flux of settling particles in the ocean has been widely explored since 1980s due to its important role in biogenic elements cycling, especially in the transport of particulate organic carbon (POC) in the deep sea. However, research in the seamount area of the oligotrophic subtropical Northwest Pacific Ocean is lacking. In this work, two sediment traps were deployed at the foot and another two at the hillside of Niulang Guyot from August 2017 to July 2018. The magnitude and composition of particle fluxes were measured. The main factors influencing the spatial variations of the fluxes were evaluated. Our results indicated a low particulate flux from Niulang Guyot area in the Northwest Pacific Ocean, reflecting low primary productivity of the oligotrophic ocean. The total mass flux (TMF) decreased from 2.57 g/(m2·a) to 0.56 g/(m2·a) with increasing depth from 600 m to 4 850 m. A clear seasonal pattern of TMF was observed, with higher flux in summer than that in winter. The peak flux of 26.52 mg/(m2·d) occurred in August at 600 m, while the lowest value of 0.07 mg/(m2·d) was shown in February at 4 850 m. The settling particles at the deep layers had similar biochemical composition, with calcium carbonate (CaCO3) accounting for up to 90%, followed by organic matter and opal, characteristics of Carbonate Ocean. The POC flux decreased more rapidly in the twilight layer because of faster decomposition, remineralization, and higher temperature. A small fraction of POC was transported into the deep ocean by biological pump. Particle fluxes were mainly controlled by the calcareous ballasts besides the primary productivity of the surface water. The advection may be another important factor affecting the flux in the seamount area. The combination of settled matters rich in foraminiferal tests with topography and currents may be the reason for regulating the local abundance of benthos on seamounts. Our results will fill in the knowledge gap of sedimentation flux, improve the understanding of ecosystem in Niulang Guyot area, and eventually provide data support for the optimization of regional ecological modeling. [ABSTRACT FROM AUTHOR]

Rapid urbanization has threatened sustainable urban development in many cities across the globe, causing green space loss and vegetation cover degradation which reduce carbon sequestration. Optimal land management practices (LMPs) in an urban context are known as ways capable of promoting urban vegetation growth and contributing to carbon sequestration. Due to variations of physical, biological, and social structures in urban areas, policymakers often lack relevant information to decide and implement site-specific LMPs. Here we try to extract the areas in need of the optimal LMPs, identify location-dependent optimal LMPs, and assess how much more carbon can be captured by applying a combination of segmenting homogeneous urban environments and neighborhood-based analysis. As one of the most developed cities in China, the greater Guangzhou area (GGA) was selected as a case study. We found that the carbon uptake from the urban vegetation in GGA could be improved on average by 185 gC m−2 yr−1 in flux (or 1.3 TgC yr−1 in total) with optimal LMPs, equivalent to a ~30% increase considering the current level of 662 gC m−2 yr−1 in flux (4.4 TgC yr−1 in total). The carbon uptake potential was found to differ considerably across locations and among different ecosystem types, highlighting spatially varied priorities for implementing optimal LMPs over the space. This study reveals the usefulness of the model in assessing carbon uptake potential from optimal LMPs and emphasizes that future urban planning may consider the importance of optimal LMPs in enhancing vegetation carbon uptake in urban planning. [ABSTRACT FROM AUTHOR]

The effect of mineral salt on the reactive dye removal was evaluated by using flat ultrafiltration (UF) membranes made of polyethersulfone (PES) and regenerated cellulose (C). Five reactive dyes varied in molecular weight (Reactive Orange 16, Remazol Brilliant Blue R, Reactive Orange 20, Reactive Black 5, Reactive Read 120) were used in the UF experiments. The applied membranes were characterized by the cut-off value equal to 10 kDa. The ultrafiltration process was performed in a dead-end mode under the transmembrane pressure of 0.2 MPa. Dye concentration in model solutions was equal to 100 mg/dm3. Two various mineral salts (NaCl and Na2SO4) were chosen to simulate the composition of dye-house baths. The concentration of monovalent and divalent salt in model dye solutions amounted to 1-2 g/dm3. Transport and separation properties of the UF membranes towards reactive dyes and mineral salts were evaluated. It was found that the separation efficiency of all tested dyes was dependent on the mineral salt presence. The effect of mineral salt on dye retention was more pronounced for membrane made of regenerated cellulose (C) than for polyethersulfone membrane (PES). In the case of the C membrane the dye retention coefficients varied in the wide range - from 55 to 83%, whereas for PES membrane the degree of dye separation was less diverse and amounted to 81-96%. The presence of mineral salt in water and dye solutions generally worsen the membrane permeability due to osmotic pressure increase as well as enhancing adsorptive fouling of dye particles in membrane matrix. [ABSTRACT FROM AUTHOR]

This study addresses the use of activated flux (MoO3, SiO2, TiO2, and CaO) for the TIG welding of chrome-manganese (Cr-Mn SSs) stainless steel. Bead-on-plate welding trials were performed to investigate the weld bead microstructure, mechanical, and electrochemical properties. The behavior of activated flux powder was studied with the orientation of fluctuations of arc voltage and dissolved oxygen in the weld bead. It was observed δ-ferrite phase evolution on employing activated flux. TiO2-assisted weld was found to have the highest mechanical properties than other TIG and ATIG welds. The presence of secondary phases (Cr23C6) in the heat-affected zone was confirmed with x-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) technique. The tensile and impact test failures were observed in all TIG and ATIG welding processes at the weld zone. Numerous ductile ridges, voids, and dimples were seen on all tensile and impact fracture surfaces. Improvement in the hardness value was observed in the weld zone of ATIG weldment than No flux. CaO-assisted weldment offers excellent pitting corrosion resistance (Epitt = - 130.164 mv) than other TIG and ATIG weldments. The degree of sensitization (DOS) of the ATIG welded sample was observed higher than the No flux TIG weld. [ABSTRACT FROM AUTHOR]

The role of a carbon-fluorine-containing additive in a flux based on the slag of silicomanganese in the formation of the structural-phase state, dislocation substructure, and fracture surface of the coating fabricated by electric arc surfacing using an Sv-08GA wire is analyzed. The relative ferrite and perlite contents and the scalar and excess dislocation densities are quantitatively estimated. [ABSTRACT FROM AUTHOR]

A flux observer for induction motors which is adaptive to the active rotor resistance variations is presented. Due to the added fluxes overestimation in the observer structure, the global exponential stability properties of the current and flux vector components and active rotor resistance estimation are ensured under conditions of persistency of excitation. The proposed observer has a simpler structure compared to existing solutions with the global stability properties. The simulation results of the observer dynamic performance investigation confirm its effectiveness. It is shown that even if the conditions of persistency of excitation are not met, the active rotor resistance is estimated correctly; consequently, the designed observer can be implemented as an identification algorithm in self-commissioning systems of induction electric drives. References 9, figures 5. [ABSTRACT FROM AUTHOR]

An advanced type of Tungsten Inert Gas (TIG) welding called Activated Tungsten Inert Gas welding (or A-TIG welding) was developed to subdue the several limitations in TIG welding. The experimental set up for A-TIG welding is the same as that of TIG welding except that an activating flux powder in a paste form is coated on the weld line preceding TIG welding. The penetration in A-TIG technique is reported to be twice or thrice that of the TIG welding process. Therefore, research is continuously progressing over the years, validating the possibility of applying A-TIG welding to various types of materials using different fluxes. Owing to this, in this paper, a detailed review is made covering multiple aspects of the A-TIG welding process starting from its evolution to the latest advancements achieved. This review categorizes different types of studies performed in A-TIG welding so as to get an explicit outlook of the implementation of A-TIG welding in different aspects. The shortcomings of various researches conducted are suggested, and the future scope of investigations on A-TIG welding is also raised in detail. [ABSTRACT FROM AUTHOR]

Fertilizer-drawn forward osmosis (FDFO) has received a lot of attention for its potential for producing fertigated water for agriculture purposes. To minimize the use of chemical-based fertilizers and support sustainable organic agriculture, this work investigated the separation performance of FO membrane for different feed concentrations (FS) of brackish water using microalgae Spirulina platensis as an organic fertilizer draw solution (DS). Different feed solution concentrations were investigated ranging 3–20 g/L NaCl, with various draw solutions of spirulina ranging 280–440 g/L. The performance was measured by water flux and recovery. The results showed that using spirulina as a draw solution is a promising solution for fertigation purposes. The results showed that Na+ in feed solution is concentrated by 41%, Cl- by 36%, and spirulina is diluted by 20% for feed salinity 5000 mg/L. The highest flux obtained with different feed solution 3000/5000/10,000/20,000 mg/L were 9/6/4.5/7 for draw solution concentration of 360/360/400/420 g/L. The calculated specific reverse solute flux (SRSF) JS/JW varies from 0.1 and 0.8 for different explored FS/DS concentrations. Flux decline and the down-time was investigated for the highest flux observed, showing 290 min of operation before cleaning action is required. [ABSTRACT FROM AUTHOR]

Oil separation from water becomes a challenging issue in industries, especially when large volumes of stable oil/water emulsion are discharged. The present short review offers an overview of the recent developments in the nanofiber membranes used in oily wastewater treatment. This review notes that nanofiber membranes can efficiently separate the free-floating oil, dispersed oil and emulsified oil droplets. The highly interconnected pore structure nanofiber membrane and its modified wettability can enhance the permeation flux and reduce the fouling. The nanofiber membrane is an efficient separator for liquid–liquid with different densities, which can act as a rejector of either oil or water and a coalescer of oil droplets. The present paper focuses on nanofiber membranes' production techniques, nanofiber membranes' modification for flux and separation efficiency improvement, and the future direction of research, especially for practical developments. [ABSTRACT FROM AUTHOR]

Anthropogenic activities have had a great impact on the characteristics of watershed pollution. The Pearl River basin is the third largest river in China, but it has been affected by eutrophication impact for a long time. This study comprehensively evaluated the nutrient pollution characteristics of the Pearl River basin from 2016 to 2018. The result shows that the ratio of total nitrogen (TN) and total phosphorus (TP), TN/TP was 24.7 of the Pearl River basin, which indicated that phosphorus was the restrictive factor for eutrophication problems. The limitation of TP maybe caused that TN is difficult to decrease through denitrification and nitrification. The fluxes of TN and TP remained stable in recent 20 years, and the flux of TN and TP transferred from the Pearl River basin to the ocean was 6.86×105 and 2.84×104 t in 2017, respectively. The Pearl River estuary had the largest discharge, accounting for more than 40% of the Pearl River basin. The TN in the West River and North River had a high pollution load, while TP pollution in the East River was very serious. It is necessary to establish an effective mechanism to control nitrogen and phosphorus. A large amount of nitrogen and phosphorus caused the decrease of dissolved oxygen (DO) and the increase of chemical oxygen demand (COD), which aggravated eutrophication. This study of nutrient elements fluxes and distribution in the Pearl River Basin are one of the important prerequisites for clarifying the causes of eutrophication, providing data and theoretical support for further water pollution control and water environmental protection in the future, and also providing a basis for pollution control decisions. [ABSTRACT FROM AUTHOR]

The present work analyses the effect of five types of oxide fluxes – SiO2, TiO2, CrO3, MnO2 and MoO3 – on the depth of penetration and pitting corrosion behaviour of UNS S32205 duplex stainless steel produced with the activated tungsten inert gas welding (A-TIG) process. Five bead-on-plate (BoP) weld samples prepared autogenously with constant weld parameters. Depth of penetration (DP), depth-to-width (D/W) ratio and weld bead width (BW) were measured and compared with reference to the weld thermal cycle. The test results of ferrite measurement and micro-hardness were compared with normal – without flux added TIG-welded sample. Macro analysis of all samples indicates that SiO2 and TiO2 flux offer enhanced penetration depth and D/W ratio, in contrast, to use of other fluxes. Possibly, under the effect of either reversed Marangoni or arc constriction or both, however, all TIG BoP weld samples exhibited poor pitting corrosion resistance. Enhanced heat input due to flux and thus resultant unbalanced ferrite austenite proportion affected pitting corrosion resistance. ASTM A 923 microstructures did not show any presence of nitride formation. Results of energy-dispersive X-ray spectroscopy and scanning electron microscopy analysis of corrosion pits showed no abnormality with the chemistry of standard 2205 DSS. [ABSTRACT FROM AUTHOR]

This study examines the water quality in the Yaqui Valley in Mexico, a semi-arid region impacted by mining, agriculture, and aquaculture. Contamination sources, health risks and ecological impacts are investigated. Freshwater was found to be contaminated by dissolved As, presumed to result from mining activities in the mountains. Drainage water revealed an overall contamination by dissolved As and by suspended particles enriched with Al, Fe and Mn, associated with runoff processes. Intermittent contamination of drainage water by Cu, K + , NO 3 - and PO 4 3- is attributed to the use of fertilizers or pesticides. In the coastal area, drainage water contains high concentrations of Na, Ca, SO 4 2- and Cl, related to salinization processes, as well as higher concentrations of dissolved As, related to solid/liquid interactions that are enhanced by salinization. This drainage water discharges into the bay, degrading the seawater quality and increasing ecological risks. Outputs of this study can serve as a reference for the protection of this economically important coastal ecosystem. Concerning health risks, this study demonstrates that groundwater is also contaminated by dissolved As, believed to be associated with transfers from the geological basement to the dissolved phase of water, and other major chemicals related to salinization processes. The findings indicate that ingesting the groundwater poses a significant risk to human health with a primary exposure risk associated with dissolved As, particularly among children. This study presents crucial data for the Yaqui population, water managers and researchers, and provides novel insights into the management and mitigation of the identified risks., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Barats reports financial support was provided by National Research Agency (ANR). Gonzalez-Perez reports financial support was provided by Consejo Nacional de Ciencia y Tecnología (CONACYT). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

A hollow fiber membrane (HFM) was previously characterized as a potential permeation component of a dissolution/permeation system. Two objectives were to assess the impact of micellization on drug permeation across HFM and identify a preferred permeation model from three models: permeation from only free drug, permeation from both free drug and micelle-bound drug, and permeation with enhancement from micelle shuttling. HFM studies were conducted under unsaturated drug conditions, using griseofulvin and the more hydrophilic drug meloxicam, with and without surfactant [sodium lauryl sulfate, polysorbate 80, and polyoxyethylene (10) lauryl ether]. Griseofulvin was micelle incorporated to a greater extent than meloxicam, such that griseofulvin flux decreased to a greater extent than for meloxicam. The griseofulvin permeation model from only free drug was rejected, since griseofulvin flux required free drug to be about 5-20 fold higher in HFM flux studies than supported by solubility studies, depending on surfactant. Permeation from both free griseofulvin and micelle-bound griseofulvin successfully accommodated observed flux, where micelle permeability was about 5-fold lower than free drug permeability for HFM with 10 KDa MWCO. Permeation with enhancement from micelle shuttling was not the preferred explanation, although the model accommodated flux data and provided aqueous boundary layer thicknesses similar to other setups., Competing Interests: Declaration of competing interest There are no conflicts of interest for these authors to declare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Based on heavy metals daily observation at the Lijin station during water-sediment regulation (WSR) event and three natural floods in 2020, we examined the effects of different flood events on heavy metal in lower Yellow River, China. The results revealed that due to different water and sediment sources and processes influencing heavy metals dynamics, the dissolved Cr, Zn As and particulate heavy metals during natural flood events were higher than those during WSR event. Dissolved heavy metals increased during water regulation and decreased during sediment regulation. Using positive matrix factorization (PMF) model, we found that sources of dissolved heavy metals during WSR event were mainly from agricultural practices, rock and soil weathering, and industrial pollution. During flood events, particulate heavy metals' concentrations varied due to dilution, human activities, and reservoir influences, with industrial and agricultural sources significantly impacting Cu, Zn, As, and Pb levels., Competing Interests: Declaration of competing interest All authors disclosed no relevant relationships., (Copyright © 2024. Published by Elsevier Ltd.)

Hydrodynamic conditions have a significant effect on the fate of microplastics (MPs). Moreover, research on the relation between hydrodynamic conditions and MPs in freshwater environments is critical and unquantified. In this regard, herein, a methodological framework integrating system monitoring with numerical simulation has been developed and successfully implemented for Dongting Lake, a large freshwater lake fed by multiple rivers. According to time-series monitoring and hydrological data, 199.29/128.50 trillion MP items entered or exited Dongting Lake in 2021. In addition, a coupled numerical model identified four key areas of MP accumulation, which overlap with nature reserves and agricultural zones, posing considerable risks to the ecological gene pool and food security. The quantitative results obtained using the developed framework enable calculation of MP inflow and outflow fluxes and facilitate analysis of MP transportation. Overall, this study provides a scientific basis for preventing and controlling MP pollution in Dongting Lake and offers valuable insights for future research on related issues in freshwater ecosystems., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, kinetic modeling of permeates flux and total hydraulic resistance of camel milk diafiltration in different conditions of pH (5.8, 6.3 and 6.8) and NaCl concentration (0, 75 and 150 mM) was performed by using 6 kinetic models. Finally, the homographic kinetic model has been selected for modeling permeates flux and exponential kinetic model has been selected for modeling total hydraulic resistance considering coefficient of determination (R2) and Root mean square deviation (RMSE). The results of ANOVA of homographic kinetic model illustrated that the linear effect of pH on all model parameters (initial flux (J0), steady-state flux (J∞), flux decline time constant (1/b) and flux decline extent (a)) and the linear effect of NaCl concentration at a 95% level on J0, 1/b and the interaction effects of pH-NaCl concentration at a 99% level on a were significant. The results of ANOVA of exponential kinetic model also showed that the linear effect of pH had a significant effect on steady-state hydraulic resistance (R∞) and the linear effect of NaCl concentration on initial hydraulic resistance (R0), R∞ and resistance increment rate (K) and the interaction effects of pH-NaCl concentration at a 95% level on k were significant. According to the results of sensitivity analysis for each 0.1 increase in pH about 1% R∞ decreased and for each 10 mM increase in NaCl concentration 2.75% R0 and 9% 1/b of the samples increased.

CsF-AlF3 was added in different mass percentages to KF-AlF3 flux, and CsF-AlF3/KF-AlF3 mixed fluxes with different components were prepared by ball milling. The melting curves of four kinds of fluxes were measured using differential scanning calorimetry (DSC). The properties of the fluxes were studied by flowing and wetting experiments. The intermetallic compounds (IMCs) at the interface of the filler metal/copper (Cu) base metal were studied by field emission scanning electron microscope (SEM-EDS), electron backscattering diffraction (EBSD). The results showed that as the mass of CsF-AlF3 increased, the solidus and liquidus temperatures of the flux gradually decreased. The flux has better flowability on the Cu and Al surfaces. In the presence of the fluxes, the wettability of the filler metal on the Al is better compared to the wettability on the Cu. Three kinds of IMCs, namely Cu9Al4, CuAl and CuAl2, were found at the interface between filler metal and Cu. The texture strength and deformation degree of CuAl2 with preferred orientation are the largest. The order of formation of IMCs is Cu9Al4, CuAl, CuAl2.

The data shared in this work represent aspects of the performance of reverse osmosis membranes during filtration. We present pressure, permeate flux, and solute rejection data gathered during cross-flow filtration experiments, which were used to (i) model water and solute permeation through the membranes and (ii) calculate concentration polarization moduli and a suite of transport properties, including water permeance, solute permeance, and water-solute selectivity. Membrane transport properties were calculated with the different approaches commonly used to simplify transport property calculations. Typical calculations of these transport properties often use simplifying assumptions (e.g., negligible concentration polarization and solute rejection close to 100%). However, the extent of the errors associated with using simplifying assumptions in this context were not previously known or quantified. This publication and corresponding dataset pertain to figures presented in the accompanying work (Armstrong et al., 2022) [1].