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The present study reports the synthesis of cobalt ferrite nanoparticles (CoFe 2 O 4 NPs) using the sol-gel precipitation process via mixing a stoichiometric ratio of cobalt chloride (1 M) and ferric chloride (2 M). The molar of ferric to cobalt was mentioned (2:1) and then 2 M of sodium hydroxide was added. The structural and morphological features of the material were assessed using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and atomic force microscopy (AFM). The electrical properties were analyzed using an LCR meter, while the magnetic properties were measured using a vibrating sample magnetometer (VSM). Fourier-transform infrared spectroscopy (FTIR) investigated the material's molecular vibrations. The X-ray diffraction (XRD) analysis revealed that all the samples exhibited a cubic spinal structure, and no additional peak was detected. Interestingly, the average size of the crystallites (D) decreased from 17.74 nm to 16.58 nm as the pH level increased from 7 to 13. This finding provides important insights into the behaviour of the tested samples under different pH conditions. The formation of the ferrite spine was confirmed by FTIR spectroscopy, with the primary detected bands (408.92–470.65 cm−1) attributed to the octahedral complexes and (516.94–588.31 cm−1) assigned to the tetrahedral ones. The dielectric and imaginary part of the dielectric constant decreased with increasing pH values excluding samples prepared at pH = 11. All samples with different pH values exhibit resonance peaks at frequencies up to (1 KHz). The magnetic measurements carried out by the VSM instrument, the result show that the saturation magnetization increases with increasing pH and the higher saturation magnetization is 68 emu. g1. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the pH (potential of hydrogen) value of diabetic foot ulcers and explored the relationship between the pH value and infection, sinus formation, stasis dermatitis, and the process of healing. From October 2022 to June 2023, 99 patients with 106 diabetic foot ulcers were selected. Diabetic foot ulcers were treated in a standardized manner by a professional team. The pH value, area, PUSH (Pressure Ulcer Scale for Healing) score, and the degree of infection of the wounds were compared before and after the treatment. The baseline wound pH value in 76.4% of the patients was in the alkaline range and was closely related to the degree of infection (P < 0.05). As the ulcers healed, the pH decreased. For moderately and severely infected diabetic foot ulcers, each unit decrease in pH was associated with a decrease in the PUSH score of approximately 4.6 points (P < 0.05). The pH values of wounds with surrounding ecchymosis dermatitis were significantly higher than those of wounds without ecchymosis dermatitis (P < 0.05). The pH value of the wound with a sinus tract was higher. After treatment, there was no significant difference in pH value between the patients with and without sinus tracts (P < 0.05). The measurement of pH value is efficient and simple, and the patient suffers no discomfort in the process. The change in pH helps predict the healing process of diabetic foot ulcers and quickly identify whether there are key factors such as infection and ischemia in the wound. It is suggested that dynamic pH monitoring be included in the whole course evaluation and intervention strategy development of diabetic foot. • Diabetic foot ulcers commonly have an alkaline pH, which is closely associated with infection severity and wound healing. • Decreasing pH levels during ulcer healing are linked to improvements in the PUSH score. • Diabetic foot ulcers with surrounding ecchymosis dermatitis exhibit significantly higher pH values. • The presence of a sinus tract in the wound does not significantly impact the pH value after treatment. • Monitoring pH value is an effective approach to predict healing progress and guide intervention strategies. [ABSTRACT FROM AUTHOR]

Soil fertility's significance in agriculture profoundly affects the well-being of farmers. A novel technique is being introduced to gauge soil categorization levels, based on soil chemical data involving elements like "Nitrogen, Phosphorus, Potassium, PH value, Organic Carbon, Electrical Conductivity, Sulphur, Zinc, iron", and more. Classification and regression methodologies are employed to predict soil categorization levels like low level, medium, and high level. The dataset for soil categorization analysis was collected from a farm within the Bhandara region of Maharashtra. The ultimate model's efficacy was ascertained through a combination of soil analysis and meticulous refinement of hyper parameters in both random forest classification and regression approaches. In pursuit of an improved model, various alternative strategies for classification and regression were explored. Evaluation metrics, including OOB error rate, AUC accuracy, error rate, recall, precision, and F-score, were applied in the classification analysis. For the regression aspect, metrics such as mean squared error, r2 score, and error rate were employed. After subjecting the experimental dataset to thorough analysis using the random forest algorithm, accurate predictions of soil fertility levels were achieved with 93% accuracy of training and 83% accuracy of testing. This method offers a reliable pathway to enhance crop productivity. [ABSTRACT FROM AUTHOR]

• Unsuitable environmental conditions lead to the fragility and weakness of leathers. • Consolidation is a vital process for fragile vegetable-tanned leathers. • Polyamide 6 is a compatible polymer with vegetable-tanned leathers. • Mechanical measurement, ATR/FTIR, DSC, contact angle, and pH value were used. • Polyamide 6 at 2 % and 3 % can be used in the treatment of historical leathers. Sometimes, vegetable-tanned leathers in museums, excavations, libraries, and storehouses deteriorate due to unsuitable environmental conditions that affect their properties. Accordingly, leather becomes weak. This study evaluates some mechanical, chemical, and physical characteristics of vegetable-tanned leather treated with polyamide 6 (PA6). The authors prepared new vegetable-tanned leather samples. PA6 at different concentrations was applied to the aged leather samples. The accelerated heat aging was applied on the new sample (reference before aging) and treated samples (aged untreated sample after treatment with PA6). Analytical techniques used were: test of the mechanical properties (tensile strength and elongation), attenuated total reflectance/Fourier Transform Infrared (ATR/FTIR), differential scanning calorimeter (DSC) measurement, contact angle, and pH measurement. The results proved that the accelerated heat aging affected the properties studied, as it reduced in the mechanical properties, pH value, and contact angle. Treating aged leather samples with PA6 improved all the properties studied. The mechanical properties, pH value, and contact angle of the treated and aged treated samples increased compared to the aged- untreated- sample. FTIR and DSC analysis proved the stability of the treated and aged treated samples compared to the aged untreated sample. The concentration of 2 % of PA6 gave the best concentrations used, and it is recommended to treat fragile vegetable-tanned leather. [Display omitted] [ABSTRACT FROM AUTHOR]

FeOCl was successfully synthesized by partial pyrolysis method and used as catalyst in Fenton-like reaction. The catalytic activity and stability of FeOCl at different initial pH were evaluated in degradation of isoniazid (INH). The experimental results showed that the pH of the solution had an important effect on the catalytic activity and stability of FeOCl. The point of zero charge (pH PZC) of FeOCl was measured to be 1.75. Adding FeOCl could change pH (before addition of FeOCl) of the solution from 3.0, 6.0, 9.0–3.0, 3.9 and 4.4, respectively, being conducive to Fenton-like reaction. The removal rates of INH by FeOCl/H 2 O 2 system at initial pH 3.0, 6.0, 9.0 were 94.48%, 92.45%, 42.32%, respectively. However, degradation efficiency was rapidly degenerative at initial pH 3.0 and 9.0 in stability test. By means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM), it was found that the rapid inactivation of FeOCl at initial pH 3.0 was caused by crystal structure transformation of FeOCl into FeOOH and the dissolved Fe, but at initial pH 9.0 was owing to the weakened pH regulation ability of the used FeOCl (only from 9.0 to 6.6). [ABSTRACT FROM AUTHOR]

In this work, the influence of soy protein isolated at different pH values (1–9) on the self-assembly behaviors of bacterial cellulose nanofibers/soy protein isolate (BCNs/SPI) colloidal particles via anti-solvent precipitation were investigated. The results showed that the formation of BCNs/SPI at pH values of 1–5 was mainly driven by electrostatic interaction, while the formation of those at pH values of 5–9 was driven by weak molecular interactions including hydrogen bonding and steric-hindrance effect. The FTIR demonstrated that the conformation of protein involved a transition from order to disorder at the level of secondary structure as pH values were away from the isoelectric point. The fluorescence spectroscopy and UV–vis adsorption spectroscopy indicated that hydrophobic region of SPI at pH value of 5 displayed more exposed as compared with that at pH values away from the isoelectric point. The changes in structure conformation of SPI induced by pH values led to the changes in properties of the BCNs/SPI colloidal particles including particle size, microstructure, crystallinity, hydrophily, thermal stability, and rheological properties. Furthermore, the structures of BCNs/SPI colloidal particles at different pH values significantly affected the stability of Pickering emulsion gels stabilized by the corresponding complex colloidal particles. This study provided a theoretical basis for the design of food-grade Pickering emulsion gels stabilized by BCNs/SPI complex colloidal particles. [Display omitted] • The self-assembly behaviors of BCNs/SPI induced by pH were compared. • The structure of SPI induced by pH affected the assembly behaviors of BCNs/SPI. • The properties of Pickering emulsion gels were markedly affected by BCNs/SPI at different pH. • This study provided a theoretical basis for design of edible Pickering emulsion gels. [ABSTRACT FROM AUTHOR]

• PPy/gC 3 N 4 /ZrO 2 nanocomposites were synthesized with varying pH values of ZrO 2 nanofiller via in-situ polymerization. • XRD, FE-SEM, and Raman studies confirmed the formation of ZrO 2 , gC 3 N 4 , PPy, and its nanocomposites. • An energy level diagram explains how the FRET energy transfer mechanism enhanced photoluminescence intensity with the pH value of filler nanoparticles. • The optical band gap energy, refractive index, color purity, CCT were calculated at ∼2.44 eV 2.17, 45%, and 33697.20 for sample S2. • Electrical conductivity and dielectric constant were determined at ∼15.9 × 10−4 S/cm and 14.7 for the optimized sample S2. The polymeric nanocomposites were synthesized via an in-situ polymerization method, optimized through pH adjustment of zirconium oxide rather than concentration variation. X-ray powder diffraction analysis revealed phase transitions and average crystallite sizes ranging from approximately 6.52–9.16 nm, depending on the pH levels. Field Emission Scanning Electron Microscopy tool is used to analyze the granular nanosheets and nanoparticles like the microstructure of polypyrrole, graphitic carbon nitride and zirconium oxide at a high resolution. UV–visible spectroscopy determined an optical bandgap energy of about 2.44 eV, a refractive index of 2.17, and an optical conductivity of 3.15 × 1010 S/cm2. Forster resonance energy transfer between Zirconium dioxide and graphitic carbon nitride significantly enhanced photoluminescence emission. PL emission and color purity (45 %) of the optimized sample were examined using photoluminescence data. Electrical conductivity of ∼15.9 × 10−4 S/cm and dielectric constant of ∼14.77 were obtained from I to V and LCR meter measurements. These properties indicate that the pH-driven nanocomposite exhibits optimized electron-hole recombination rates, electrical conductivity, and suitable bandgap energy, making its potential impact as an emissive layer material for OLED applications. [ABSTRACT FROM AUTHOR]

The color and structural stability of blueberry anthocyanins (BAs) are significantly affected by pH changes during processing. In this study, we present the potential effects of the thermal stability, structural characterization, and binding mechanism of BAs with β -casein (β -CN) at pH 2, 4, and 6 for the first time. The pH was found significantly affect the ability of β -CN to protect BAs from thermal, vitamin C, and sucrose induced degradation. Scanning electron microscopy (SEM) resolved the microstructural differences of β -CN-BAs at varying pH values. Multispectral analysis showed that as pH increases, the electrostatic interaction between β -CN and the major monomer of anthocyanins Cyanidin-3- O -glucoside (C3G) are replaced by hydrogen bonding and van der Waals forces, and then electrostatic interactions are again the dominant force. In vitro gastrointestinal digestion confirmed that the protein stabilized C3G under varying pH conditions. Nuclear magnetic resonance (NMR) spectroscopy reveals the connection between the multiple equilibrium forms of C3G (hemiketal, cis -chalcone, and trans -chalcone) and β -CN on the formation of complexes between multiple equilibrium forms to specifically elucidate the mechanism of its stabilizing effect. Molecular docking simulation revealed the significance of electrostatic interaction and hydrogen bonding, where the highest binding match was achieved at pH 2, with a minimum binding energy. These interactions can effectively promote stable complexation of β -CN with C3G. These findings have practical implications for protein regulation of the relationship between the equilibrium forms of different anthocyanins and can guide the stabilization of anthocyanin-rich products. [Display omitted] • The β -casein-C3G composite system was prepared at different pH values (2, 4, and 6) of common foods that satisfy various C3G forms. • pH may play a critical role in the interaction between C3G and β -casein. • The β -casein-C3G complex system had the lowest binding energy at pH 2. • NMR and molecular docking simulations were used to explore the different forms of C3G existence. [ABSTRACT FROM AUTHOR]

The current study examined the corrosion resistance of lightweight geopolymer concrete (LWGPC) incorporating sintered fly ash aggregate (SFA) as the coarse aggregate. The LWGPC was developed from a mixture of ground granulated blast furnace slag (GGBS) and fly ash (FA). The geopolymer binder is composed of 70 % FA and 30 % GGBS. The study is also directed towards understanding the means by which, LWGPC can contribute to the development of a sustainable environment. Since the alkaline content to binder (AC/B) ratio substantially impacts the performance of LWGPC, corrosion studies were performed on a broad spectrum of AC/B ratio ranges from 0.3 to 0.8 at an interval of 0.1. To assess the corrosion performance of various developed concretes, the coarse aggregates were completely substituted with coarse SFA. The assessment was conducted using several tests, including accelerated carbonation test, half-cell potential, surface resistivity test, pH test, and corrosion rate test with Tafel plots analysis. The results demonstrate that an inverse relationship exists between the AC/B ratio and all the corrosion parameters of LWGPC samples investigated. The highest level of corrosion resistance is achieved at the lowest AC/B ratio. The air dry density of LWGPC varied from 1850 to 1908 kg/m3 after 28 days of ambient curing, fulfilling the different codal guidelines to be designated as lightweight concrete. The LWGPC samples had carbonation depths of 5–44 mm, corrosion rates of 0.0209–0.222 mils per year (mpy), surface resistivity of 22.5–45.5 kΩ-cm, and pH between 11.5 and 12.5. The above results demonstrate satisfactory performance for structural applications, particularly for samples with a low AC/B ratio. SEM findings also strongly correlate with corrosion parameter information. The LCA of LWGPC has achieved lower values of Embodied energy (EE) and Global Warming Potential (GWP) than the OPC based lightweight concrete, with 57 % and 55 % reductions respectively. • The corrosion behaviour was observed with various AC/B ratios over time. • LWGPC's carbonation attributes differ significantly from OPC's. • The GP binder with SFA showed distinct microstructural and corrosion resistant behaviour. • After one year, corrosion rates fall into the negligible to moderate category. [ABSTRACT FROM AUTHOR]

The shelf life, storage stability and microbial changes of instant rice noodles (IRN) during storage were systematically investigated. The total aerobic viable count, mold and yeast counts of all samples increased gradually, and the shelf life of IRN sample with ε-polylysine hydrochloride (JL) preserved at 4 °C was significantly extended to 14 days. The pH value of sample with JL decreased gradually whereas the pH value of sample with citric acid (NM) increased slightly during storage. In IRN, molds displayed a greater spoilage potential than bacteria and yeasts. The 16S rDNA sequencing results indicated that preservatives, rather than temperature deduce to the significant differences of spoilage bacterial community among samples, and the NM considerably decreased the bacterial diversity internal transcribed spacer (ITS) region. rDNA sequencing results demonstrated that temperature was the critical factor in shaping fungal spoilage microbiota (Mantel test r = 0.16143, P < 0.05). Moreover, Spearman correlation analysis revealed that the abundance of partial microorganisms was significantly related to pH or temperature. The abundance of Achromobacter (r = −0.66276, P < 0.01), Delftia (r = −0.59983, P < 0.01), and Phyllobacterium (r = −0.55765, P < 0.01) were negatively correlated with pH. Additionally, the temperature was positively related to the relative abundance levels of Romboutsia (r = 0.517, P < 0.005), Arthrobacter (r = 0.446, P < 0.05), Bacillus (r = 0.551, P < 0.01), Bacteroides (r = 0.456, P < 0.05), and norank_f__JG3 0-KF -CM45 (r = 0.449, P < 0.05). These findings provided guiding information in selecting targeted preservatives and environmental condition for this innovative high moisture food. • Quality and shelf-life of high-moisture instant rice noodles (IRN) is investigated. • Combination of ε-polylysine hydrochloride and 4 °C preserves the IRN effectively. • The dominant bacterial and fungal genera in spoiled IRN are reported. • Preservatives cause significant difference of bacterial microbiota among samples. • Temperature plays a major role in fungal community difference than preservatives. [ABSTRACT FROM AUTHOR]

In saline-alkali or salt-lake areas, the influence of pH value of underground aqueous solution and carbonation on the deterioration of cement-based materials remains an open question. This study utilizes various techniques to investigate the physical properties and degradation mechanism of partially immersed mortar incorporated with different dosages of fly ash exposed to combined action of salt solutions (10 wt% Na 2 SO 4 , 3.5 wt% NaCl + 10 wt% Na 2 SO 4 , and tap water) at different pH values (pH 5, 7, and 9) and carbonation (accelerated carbonation: 20 vol% CO 2 and natural carbonation: 0.035 vol% CO 2). The results indicate that the degree of deterioration of mortar increases with dosage of fly ash and pH value of salt solution, with the maximum mass loss exceeding 25 %. Physical sulfate attack (PSA) is responsible for the partially immersed mortar exposed to combined action of salt attack at various pH values and natural carbonation. However, when carbonation is accelerated, a more severe deterioration occurs, with the durability time of mortar reduced by nearly 60 %. PSA and decomposition of C-S-H are mainly responsible for the deterioration of mortar, while the formation of thaumasite and natrite is partially responsible for the deterioration of mortar. The presence of NaCl in mixed salt solution inhibits the precipitation of Na 2 SO 4 crystals; the precipitation of NaCl clogs the pore network of mortar, which impedes the progressive penetration of CO 2. The presence of NaCl in mixed salt solution is beneficial to salt resistance and carbonation resistance of mortar. • The impact of pH of salt solution and carbonation on physical sulfate attack (PSA) of mortar is carried out in this study. • Degree of deterioration of partially immersed mortar increases with dosage of fly ash and pH value of salt solution. • The deterioration of partially immersed mortar exposed to salt solution at various pH and natural carbonation is PSA. • Under accelerated carbonation, PSA, decomposition of C-S-H, formation of thaumasite are all responsible for deterioration. [ABSTRACT FROM AUTHOR]

Shake flasks are widely spread in microbial process development. Characterization of the processes by manual offline sampling is time-consuming, highly laborious and a contamination risk. Online monitoring of key parameters would provide deeper insights, while saving time and effort. In this study, a device for optical online monitoring of dissolved oxygen tension (DOT), biomass, pH value and viscosity in shake flasks is presented. DOT measurement relies on fluorescent oxygen sensitive nanoparticles. The fluorescence intensity signal of the nanoparticles is used to trigger the DOT and scattered light measurements inside the rotating bulk liquid. The scattered light signal (610 – 630 nm) can be correlated to offline measured optical density OD 600 , even at elevated viscosity. The pH value is monitored online by using pH sensor spots, fixed inside the shake flasks. The shift of the angle of the bulk liquid Θ-Θ 0 is correlated to the offline measured viscosity. Detection of the leading edge of the bulk liquid, necessary for viscosity measurement, can be performed either using the fluorescence intensity signal of the oxygen nanoparticles or the scattered light signal. • Tracking of the rotating bulk liquid via fluorescence signal of nanoparticles. • Online signals of DOT and pH indicate switches in metabolic activities. • Scattered light correlates to offline optical density even at elevated viscosities. • Out of phase phenomenon leads to foam formation in unbaffled shake flasks. • Online monitoring of viscosity also possible solely via the scattered light signal. [ABSTRACT FROM AUTHOR]

The dissolution of silicate minerals plays a crucial role in many natural geological processes. In order to better comprehend the reaction mechanisms and dissolution characteristics of montmorillonite in different acidic systems, the effects of interfacial reactions of montmorillonite with oxalic and sulfuric acid solutions at various pH levels on the ionic dissolution, crystal structure, and micro-morphology were studied, and the morphology of aluminum and saturation index of secondary mineral were simulated. It was shown that the dissolution amounts of Mg2+, Al3+ and Si4+ in montmorillonite structure decreased with the increase of pH value, which reflected the dependence of montmorillonite dissolution on the pH value of solution. The dissolution percentages of Mg2+, Al3+ and Si4+ after the reaction of montmorillonite with oxalic acid solution were greater than those in sulfuric acid solution, and the highest dissolution rate of Al3+, indicated that both ligands and protons attacked the surface sites of montmorillonite and accelerated the dissolution of ions. Moreover, oxalate ligands exerted specific binding effects on Al3+ ions. While reacting with oxalate and sulfate, the tetrahedral, octahedral and interlayer cations of montmorillonite exhibited the non-stoichiometric and inconsistent dissolution. The oxalate ligands have a strong complexation effect on Al3+, so that Al3+ in oxalate solution exists in the form of aluminum oxalate complex, which reduces the effective concentration of Al3+ in solution and promotes the dissolution of Al3+ in montmorillonite structure. The Mg2+ ions settled at octahedral substitution sites possessed weak stability, while those from the interlayer featured strong interlayer interchangeability, demonstrating the dissolution percentage up to 10.85 % and 8.62 % even in oxalic and sulfuric acid solutions at pH of 6.5. All secondary mineral phases in the solution were undersaturated, making the montmorillonite dissolution difficult to balance. Montmorillonite has a high cation exchange capacity, which makes it have a strong buffer capacity to exogenous acids. This study helps to explain the dissolution process of montmorillonite in inorganic and organic acid solutions at different pH value. • The dissolution of montmorillonite depends on the pH of the solution. • The tetrahedrons, octahedrons and interlayer cations exhibit non-stoichiometric dissolution. • The oxalate ligands exerted specific binding effects on Al3+ ions. • The dissolution of Al3+ weakens the supporting force of the silicon-rich edge, thus collapsing to form a closed space. • The dissolution of cations in montmorillonite structure will change the microstructure, specific surface area and pore volume. [ABSTRACT FROM AUTHOR]

The present study has investigated the influence of preparing conditions, including aging temperature and time, pH, and T calcination , on the co-precipitated ZnO–CuO–Al 2 O 3 –Cr 2 O 3 mixed oxide at a high-temperature water gas shift reaction. XRD, BET, FTIR, TG-DTA, SEM, TEM, and H 2 -TPR were used to characterize the relationships between the synthesis parameters and the physicochemical features. The investigation proved that the activity in aging 5 h could be related to higher pore volume and lower crystalline size of 0.24 cm3g-1 and 6.4 nm, respectively. Also found that increasing the aging temperature to 60 °C results in a rise in the surface area and particle size of less than 6 nm, enhancing the catalyst activity. The findings showed that raising the T calcination reduced the surface area from 132 to 65 m2 g−1. It has been concluded that the CO conversion of 70 % was obtained when aged at 60 °C and calcination temperature of 400 °C. [Display omitted] • The synthesis method affects the structural properties of the ZnO–CuO–Cr 2 O 3 –Al 2 O 3 catalyst. • pH, ageing temperature and time have great influence on the structure of the catalyst. • The catalyst prepared by the optimum condition presented high activity and stability. [ABSTRACT FROM AUTHOR]

In the environment, soil colloids are widespread and possess a significant adsorption capacity. This makes them capable of transporting different pollutants, presenting a potential risk to human and ecological well-being. This study aimed to examine the adsorption and co-migration characteristics of benzo(a)pyrene (BaP) and soil colloids in areas contaminated with organic substances, utilizing both static and dynamic batch experiments. In the static adsorption experiments, it was observed that the adsorption of BaP onto soil colloids followed the pseudo-second-order kinetic model (R2 = 0.966), and the adsorption isotherm conformed to the Langmuir model (R2 = 0.995). The BaP and soil colloids primarily formed bonds through π-π interactions and hydrogen bonds. The dynamic experimental outcomes revealed that elevating colloids concentration contributed to increased BaP mobility. Specifically, when the concentration of soil colloids in influent was 500 mg L−1, the mobility of BaP was 23.2 % compared to that without colloids of 13.4 %. Meanwhile, the lowering influent pH value contributed to increased BaP mobility. Specifically, when the influent pH value was 4.0, the mobility of BaP was 30.1 %. The BaP's mobility gradually declined as the initial concentration of BaP in polluted soil increased. Specifically, when the initial concentration of BaP in polluted soil was 5.27 mg kg−1, the mobility of BaP was 39.1 %. This study provides a support for controlling BaP pollution in soil and groundwater. [Display omitted] • Adsorption process of BaP on soil colloids follows quasi-second order kinetic model. • BaP is adsorbed by soil colloids through π-π interactions and hydrogen bonds. • The mobility of BaP increased with an increase in the inflow colloid concentration. • The mobility of BaP increased with a decrease in the influent pH value. • The mobility of BaP decreased with an increase in the initial BaP concentration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Macro/mesoporous silica is synthesized by a non-template hydrothermal approach. • pH value plays a pivotal role in the formation of macro/mesoporous structure. • Mesoporous silica with very high surface area is obtained at pH ≤ 3. • Mesoporous silica shows much higher toluene adsorption than macroporous silica. Porous silica samples were prepared by a non-template approach using silicate and HCl at different pH values. Macroporous silica with a low surface area of 72.0 m2/g was obtained at pH = 7. Surprisingly, mesoporous silica with very high surface area of 806.0 m2/g was obtained at pH = 3. This was due to the formation of protonated silicic acid molecules under acidic condition which had enough time for the polymerization and assembly to mesoporous structure, and the rapid polymerization and assembly of silicic molecules under neutral condition to silica nanoparticles among which macropores were formed. The mesoporous silica showed a saturation toluene adsorption capacity of 79.1 mg g−1, 9 times higher than that of the macroporous silica. [ABSTRACT FROM AUTHOR]

Plants live in a highly dynamic environment and require to rapidly respond to a plethora of environmental stimuli, so that to maintain their optimal growth and development. A small plant peptide, rapid alkalization factor (RALF), can rapidly increase the pH value of the extracellular matrix in plant cells. RALFs always function with its corresponding receptors. Mechanistically, effective amount of RALF is induced and released at the critical period of plant growth and development or under different external environmental factors. Recent studies also highlighted the role of RALF peptides as important regulators in plant intercellular communications, as well as their operation in signal perception and as ligands for different receptor kinases on the surface of the plasma membrane, to integrate various environmental cues. In this context, understanding the fine-print of above processes may be essential to solve the problems of crop adaptation to various harsh environments under current climate trends scenarios, by genetic means. This paper summarizes the current knowledge about the structure and diversity of RALF peptides and their roles in plant development and response to stresses, highlighting unanswered questions and problems to be solved. • Rapid alkalinization factor (RALF) peptides modulate pH of the extracellular matrix in plant cells. • RALFs play key role in plant growth and development. • RALFs are important regulators in plant intercellular communications, integrating various environmental cues. • Important role of RALFs as component of abiotic stress tolerance mechanisms has emerged. [ABSTRACT FROM AUTHOR]

To obtain the great surface quality of Ti–6Al–4V and achieve high efficiency in the polishing process, the chemistry enhanced shear thickening polishing (C-STP) was proposed, and the polishing performance of different pH slurry was studied. The results show that the material removal rate gradually increases as the pH value decreases from 10 to 1, and the best surface quality is obtained at pH 2. The corrosion current density and potential were measured by potentiodynamic polarization under three typical pH values. It is confirmed that the most massive corrosion rate presents at pH 2, and the passive film is most susceptible to be produced at pH 10. The reaction resistance was measured by electrochemical impedance spectroscopy to clarify the polishing mechanism. Under acidic conditions, the chemical reaction product on the surface can be quickly removed by mechanical action of the abrasive. On the contrary, the passive film formed on the surface under the alkaline condition is difficult to be removed. The corrosion reaction products were determined by X-ray photoelectron, and the chemical reaction under acid-base environment was derived. MRR reached 107.3 nm/min under the selected process parameters, and the surface roughness (S a) is reduced from 124 nm to 8.6 nm within 15 min. • A new method Chemistry enhanced Shear Thickening Polishing (C-STP) is proposed to polish Ti–6Al–4V efficiently, and the influence of pH value of slurry on Ti–6Al–4V polishing performance is investigated. • MRR gradually increases from 26.1 nm/min to 115.4 nm/min as the pH value decreases. The best surface roughness (Sa) is 8.6 nm obtained at pH 2 and the removal rate reaches the 107.3 nm/min. • Under alkaline conditions, the passive film on the surface of Ti–6Al–4V is produced and difficult to be removed, result in low removal efficiency and surface quality. Under acidic conditions, a corrosion layer is produced which can be quickly removed by abrasive particles. [ABSTRACT FROM AUTHOR]

Soil salinization is a critical factor limiting growth and causing physiological dysfunction in plants. The damage from alkaline salt in most plants is significantly greater than that from neutral salt. However, there is still a lack of research on the action mechanism by which saline alkali stress on plants under the same salt concentration across different pH values. The present study examined the effects of different pH values (7.0, 8.0, 9.0, and 10.0) under the same salt concentration (200 mmolL−1) on photosynthetic function, photoprotective mechanism, nitrogen metabolism, and osmotic regulation in alfalfa (Medicago sativa) leaves, including a transcriptomic analysis of changes in gene expression related to the above metabolic processes. The results showed that low pH saline alkali stress (pH 7.0 and 8.0) promoted chlorophyll synthesis in alfalfa leaves, and non-photochemical quenching (NPQ) and cyclic electron transfer (CEF) were promoted. There was no significant effect on plant growth or photochemical activity. The soluble sugar, proline, and soluble protein contents did not change significantly, and there was no obvious oxidative damage in alfalfa leaves. However, when pH increased to 9.0 and 10.0, KEGG enrichment analysis showed that photosynthesis (map00195) and nitrogen metabolism (map00910) were significantly enriched (P < 0.05), and PSII antenna protein coding genes were down-regulated under pH 9.0 and 10.0 treatments. The activities of PSII and PSI were decreased under high pH saline alkali stress, and the expression levels of the photosynthetic electron transporter-related genes PetA , PetB , petE , and petF were also significantly down-regulated. PSII was more sensitive to high pH saline alkali stress than PSI, and the PSII receptor side was more sensitive to high pH saline alkali stress than the PSII donor side. The activities of the oxygen-evolving complex (OEC) and PSI were significantly damaged only at pH 10.0. The activities of nitrate reductase (NR) and nitrite reductase (NiR), the expression levels of their genes, and the content of soluble protein were also decreased under pH 9.0 and 10.0 treatments. The inhibition of plant growth and oxidative damage to alfalfa leaves caused by high pH saline alkali stress were mainly related to the inhibition of photosynthesis (light energy absorption, electron transfer) and nitrogen metabolism (NO 3 − reduction). Under high pH saline alkali stress (pH 10.0), the photoprotection mechanisms such as CEF and NPQ were inhibited, which was also one of the important reasons for photoinhibition in alfalfa leaves. The accumulation of osmotic adjustment substances, such as soluble sugar and proline, was an important mechanism by which alfalfa physiologically adapted to high pH alkaline salt stress. • Low pH saline alkali stress promoted chlorophyll synthesis in alfalfa leaves, photoprotective mechanisms were activated. • As the pH value increased 9.0 and 10.0, photosynthetic electron transfer was blocked and oxidative damage occurred in leaves. • CEF and NPQ were inhibited, photosynthetic inhibition especially the OEC damaged under pH10.0 alkaline salt stress. • Accumulation of osmotic adjustment substances was an important mechanism by which alfalfa to saline alkali stress. [ABSTRACT FROM AUTHOR]

The optimal pH value of the titration endpoint remains uncertain for the synthesis of antimony-doped tin oxide by the co-precipitation method. In this study, the influence of the pH titration endpoint on doping level and optical performance was systematically studied. The phase composition, microstructure, the valence state of Sb ions and thermodynamic behaviors of antimony-doped tin oxide were comprehensively investigated. The UV–Vis–NIR transmittance spectra of ATO glass and SEM images of ATO coating were also studied. When the pH value of the titration endpoint was 6, the measured doping ratio of Sb was 10.81% which was close to the initial Sb doping level of 10%. In the meanwhile, the content of Sb5+ ions also reached the maximum value of 76.4%. Especially, the spectrally selective coating exhibited optimally spectral selectivity with the average visible light transmittance of 77.24% and the average near-infrared shielding ratio of 80.06% respectively. The results show that the doping level and optical properties of antimony-doped tin oxide certainly relied on the pH value of the titration endpoint. It is of great significance to scale up the production of antimony-doped tin oxide with superior near-infrared shielding performance and promote its practical application in the field of energy-efficient glazing. [ABSTRACT FROM AUTHOR]

Gallbladder cancer can be difficult to detect in its early stages and is prone to metastasize, causing bile duct obstruction, which is usually treated by stent implantation in clinic. However, the commonly used biliary stents are non-degradable, which not only prone to secondary blockage, but also need to be removed by secondary surgery. Biodegradable magnesium (Mg) is expected to one of the promising candidates for degradable biliary stents due to its excellent physicochemical property and biocompatibility. In this work, we studied the influence of high-purity Mg wires on gallbladder cancer through in vitro and in vivo experiments and revealed that the degradation products of Mg could significantly inhibit the growth of gallbladder cancer cells and promote their apoptosis. Our findings indicate that Mg biliary stent possesses the function of draining bile and treating gallbladder cancer, suggesting that Mg has good application prospects in biliary surgery. Current research and development of biomedical magnesium are mainly concentrated in the cardiovascular and orthopedics field. Degradable magnesium bile duct stents have great application prospects in the treatment of bile duct blockage caused by bile duct-related cancers. At present, the effect of magnesium implants on gallbladder cancer is not clear. Our work verified the effectiveness of magnesium wire implants in inhibiting gallbladder cancer through in vivo and in vitro experiments, and studied the effect of magnesium degradation products on gallbladder cancer cells from the perspective of cell proliferation, apoptosis and cycle. This study provided new understanding for the application of magnesium in biliary surgery. [Display omitted] [ABSTRACT FROM AUTHOR]

The expensive cost and high carbon footprint of commercial alkaline activators hindered the promotion and industrialization of geopolymers. The rising demand for geopolymer as low carbon and excellent building materials will lead to enormous research works towards to low carbon alkaline activator. This study aimed to explore the impact of red mud (RM)/carbide slag (CS) binary alkaline wasted-derived activator (RCA) on the macroscopic and microscopic properties of RCA activated cementitious materials (RCM) prepared with titanium gypsum (TiG) and granulated blast furnace slag (GBFS). It is proposed to adjust the pH value of solid waste powder for calibrating the waste-derived activator, prepare RCM and explore the relationship between its mechanical properties and hydration products. The research showed that the highest flexural and compressive strengths at 28 days occurred with a dosage of 0.8 wt% CS, meeting the strength requirements of 52.5 R Portland cement. It is worth noting that RCM with binary alkaline waste-derived activators with appropriate pH values can exhibit excellent early mechanical properties. Raising the pH of RCA significantly improves the compressive and flexural strength, increasing them to 30.7 MPa and 6.3 MPa at 3 d, and to 60.7 MPa and 10.8 MPa at 28 d. The primary hydration products of RCM include C(N)-A-S-H gels, ettringite, and gypsum crystal phase, which contribute to the development of mechanical strength. Due to the difference in the alkaline environment required for the growth of C(N)-A-S-H gel and ettringite crystal, the increase in RCA pH value has been found to both inhibit the growth of ettringite to a certain extent and promote the precipitation of C(N)-A-S-H gels, improving the chemical structure of the hydration products and the pore distribution characteristics of the RCM. Furthermore, the research has been successfully applied in a pilot test in Jiaozuo, China. RCM introduces a novel concept for the efficient and industrial-scale utilization of solid waste. This study can provide a fundamental academic and industrialized support and a novel concept for the whole solid waste cementitious materials especially from alkaline industrial solid wastes such as RM and CS. [Display omitted] • RM/CS binary waste-derived activators have been incorporated to create RCM of whole solid waste. • The pH value of the waste-derived activators contributes to mechanical performance of RCM. • RCA pH values have been adjusted in system of RCM and control growth of AFt crystal and C(N)-A-S-H gels. • The pH value of solid waste powder has been proposed to adopted to calibrate the waste-derived activators and prepare RCM. [ABSTRACT FROM AUTHOR]

In this study, a standard pH test procedure, based on the high alkalinity of electric arc furnace oxidizing slag, was developed for rapid content evaluation of potentially hazardous slag in the fine aggregate and recommended standards are further proposed. The advantages of the developed procedure include easy equipment acquisition, simple test method, short time, and high accuracy. This study found that sample size, water source, and filtrate process were the factors affecting the pH test accuracy. In the test, the pH increased with a decrease in the aggregate size when the proportion of electric arc furnace oxidizing slag in aggregate was fixed, especially when the aggregate size was less than 0.225 mm. Upon comparison of the results of autoclaved mortar bar expansion tests, a good logarithmic relationship was observed between pH and electric arc furnace oxidizing slag content. It is suggested that pH 9.0 could be used as the standard to determine excessive electric arc furnace oxidizing slag in fine aggregate. • Proposed a standardized process for rapidly assessing pH in fine aggregates, addressing hazards from electric arc furnace oxidizing slag (EAFOS). • Optimized pH testing factors: D100 particles, RO water, 10 % solid content, filtration through 5A + 5B paper before measurement. • Sample pH values consistently showed a logarithmic relationship with EAFOS content proportion. • pH values over 9.0 indicate excessive EAFOS content in fine aggregates, making them unsuitable for further application. [ABSTRACT FROM AUTHOR]

For both professional and amateur athletes, perspiration analysis technique is considered as a powerful tool for real-time monitoring the athletes' physiological status during sports. This study presents an innovative self-powered wireless sweat-analysis patch worn on the skin for real-time monitoring chloride concentration and pH levels in perspiration. The patch consists of two main components: self-powered unit and sensing unit. The power unit, made of piezoelectric ceramic materials, converts mechanical energy during exercise into electrical energy to drive the whole system. The sensing unit has the functions of sampling and analyzing the sweat, and wireless communication. Through an exactly designed hydrophobic and hydrophilic composite microchannel structure, sweat is effectively guided to the storage chamber. The colorimetric fabrics embedded in the chamber respond to the presence of chloride ions and pH levels in the sweat, producing a color-changing reaction. Color sensors above the fabrics detects these color changes for analyzing the sweat, while Near Field Communication (NFC) technology wirelessly transmits this information to outside mobile devices or data-collection cloud. This system not only provides a new avenue for real-time monitoring of athletes' health status but also offers a scientific basis for adjusting training plans. [Display omitted] • The patch converts mechanical energy into electrical energy offers a new way to work for longer periods. • The patch can monitor chloride levels and pH in sweat in real-time. • The combination of hydrophobic and hydrophilic microchannel structure directs the sweat. • Color sensors and NFC technology improve the convenience and efficiency of data transmission. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel green chemical mechanical polishing (CMP) is developed for CoCrMo alloy, including silicon sol, hydrogen peroxide, tartaric acid and deionized water. • The atomic surface obtained in this work has the lowest value of surface roughness, compared with those published on CoCrMo alloys previously. • Chelating formulas are proposed between tartaric acid and Co ions. • X-ray photoelectron and infrared spectroscopies reveal that hydrogen peroxide dominated the oxidation processes in CMP, forming oxides of Co, Cr and Mo. Cobalt-chromium-molybdenum (CoCrMo) alloy has superior wear resistance, high corrosion resistance and excellent biocompatibility. However, these properties make CoCrMo alloy become a difficult-to-machine material. Nevertheless, high-performance CoCrMo devices strictly require the surface roughness Ra less than 1 nm, arising a challenge for ultraprecision machining. To overcome the challenge, a novel green chemical mechanical polishing (CMP) is developed, including silicon oxide, hydrogen peroxide, tartaric acid and deionized water. After CMP, surface roughness Ra of 0.16 nm is achieved for CoCrMo alloy. Compared with those published on CoCrMo alloys previously, the surface roughness is the lowest. X-ray photoelectron and infrared spectroscopies reveal that hydrogen peroxide dominated the oxidation processes in CMP. Co oxides were softened and dissolved by hydrogen ions. Relatively, Cr and Mo oxides showed better stability and less dissolution in tartaric acid, avoiding excessive corrosion. The remaining oxides are removed by silicon oxide. The metal ions released are chelated by tartaric acid during the polishing process. The chelation formulas of metal ions and tartaric acid are further proposed. The developed novel green CMP provide new insights to manufacture atomic surface on an alloy with high corrosion and wear resistances, which is beneficial for the potential applications on medical devices. [ABSTRACT FROM AUTHOR]

Reverse-seepage and Saturation based Active Anti-corrosion Technology (RS-AAT) is a novel and environmentally-friendly approach that enhances the ability of unsaturated concrete in marine alternating wet-dry areas to resist chloride ion intrusion. Comprehending its influence on ions transport and the pore structure within the concrete is vital for assessing the rationality of the technique and further predicting its service life. In this study, cross-section specimens of cast in situ concrete piles with RS-AAT were exposed to a chloride wet-dry cycling environment for 150 days. Spatiotemporal variation patterns of chloride ion content, pore fluid pH, and pore structure in the concrete cover were investigated by free chloride titration, pH determination, and mercury intrusion porosimetry (MIP). The findings indicate that RS-AAT can effectively inhibit chloride ion intrusion into the protective layer of concrete. Moreover, implementing alkaline water in RS-AAT elevates the pore fluid pH and improves the compactness of the pore structure, especially diminishing the harmful pore ratio. Besides, increasing the number of distributed permeable pipes reinforces these effects and reduces the technology's dependence on water pressure. This insight demonstrates the viability of using alkaline water and distributed permeable pipes in RS-AAT to bolster the resistance of concrete structures to chloride ion erosion in an environmentally sustainable manner. • A novel approach (RS-AAT) to restrain chloride invasion into unsaturated concrete. • Extra-supplemental seepage solution (alkaline/deionized) actively alter pore fluid pH. • Alkaline water reduces the proportion of harmful pore levels. • Distributed permeable pipes decrease the needs of pressure. [ABSTRACT FROM AUTHOR]

pH is usually used to assess the corrosion resistance and bacteriostasis of lubricants. In this paper, the electroosmotic and tribological characteristics of water-based lubricants at AISI 52100 steel/alumina ceramic friction interfaces are evaluated as an effect of pH value. A self-excited electric field (SEEF) generated by interface material frictional electrification induces the lubricant electroosmosis. Appropriately increasing the pH can improve the electroosmotic abilities of lubricants by changing the electrical double layer (EDL) structures at the friction material/lubricant interfaces. The lubricant tribological performance and penetrability are improved upon increasing the pH from 7 to 10. This is attributed to the fact that the lubricant with favorable electroosmotic performance shows a better penetrability, thus exerting an excellent effect of anti-friction and anti-wear. [Display omitted] • An appropriate increase in pH can improve the tribological performance of lubricants. • The self-excited electric field at steel/ceramic interface can drive the lubricant electroosmotic flow. • Appropriately increasing the pH can increase the Zeta potential to improve the electroosmotic ability of lubricants. [ABSTRACT FROM AUTHOR]

The in vivo detection of small active molecules in plant tissues is essential for the development of precision agriculture. Tryptophan (Trp) is an important precursor material for auxin biosynthesis in plants, and the detection of Trp levels in plants is critical for regulating the plant growth process. In this study, an electrochemical plant sensor was fabricated by electrochemically depositing a polydopamine (PDA)/reduced graphene oxide (RGO)-MnO 2 nanocomposite onto a glassy carbon electrode (GCE). PDA/RGO-MnO 2 /GCE exhibited high electrocatalytic activity for the oxidation of Trp owing to the combined selectivity of PDA and catalytic activity of RGO-MnO 2. To address the pH variability of plants, a reliable Trp detection program was proposed for selecting an appropriate quantitative detection model for the pH of the plant or plant tissue of interest. Therefore, a series of linear regression curves was constructed in the pH range of 4.0–7.0 using the PDA/RGO-MnO 2 /GCE-based sensor. In this pH range, the linear detection range of Trp was 1–300 μM, the sensitivity was 0.39–1.66 μA μM−1, and the detection limit was 0.22–0.39 μM. Moreover, the practical applicability of the PDA/RGO-MnO 2 /GCE-based sensor was successfully demonstrated by determining Trp in tomato fruit and juice. This sensor stably and reliably detected Trp levels in tomatoes in vitro and in vivo, demonstrating the feasibility of this research strategy for the development of electrochemical sensors for measurements in various plant tissues. Image 1 • An electrochemical sensor detects tryptophan (Trp) in vivo and in vitro. • Trp selectively adsorbed by polydopamine is efficiently electro-oxidized by RGO-MnO 2. • Linear regression models at pH 4–7 are suitable for the variable pH of plants. • The in situ detection of free Trp levels is achieved in tomato fruit and juice. • The Trp levels determined in vivo and in vitro are correlated. [ABSTRACT FROM AUTHOR]

Al doped ZnO (AZO) nanoparticles were successfully prepared by a novel sol-gel combustion method using Zn, Al(NO 3) 3 ·9H 2 O, HNO 3 , C 6 H 8 O 7 ·H 2 O, CH 4 N 2 O as raw materials. The effects of Al doping concentration, pH value and calcination temperature on the thermal effect, crystal structure, morphology, composition and sintering activity of AZO nanoparticles were characterized by TG-DTA, XRD, EDS, FESEM and Archimedes' method. Results indicated that AZO nanoparticles exhibited improved crystallinity with the increase of calcination temperature. Al atoms were doped into ZnO lattice without forming other new phases. The calcination temperature, Al doping concentration and pH value of AZO nanoparticles had a significant influence on the sintering activity of AZO nanoparticles. Al doped ZnO nanoparticles synthesized at pH value of 4 and calcined at 600 °C showed the best sintering activity, which was mainly owing to formation of both well-crystallized and very fine AZO nanoparticles, thus providing raw sources with high-activated and naked surfaces without hydroxyl radicals or organic residuals. [ABSTRACT FROM AUTHOR]

NASICON-type solid electrolyte powders Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) are synthesized by spray-drying and assisted sintering processes. The effects of different pH values of the spray-dried precursor solution on the crystallinity, morphology, ionic conductivity, compaction density and cycling stability of the LATP solid electrolyte sheets are investigated. The LATP-6.0 solid electrolyte sheets present the most perfect microstructure with a compaction density of 2.968 g cm−1 and the highest ionic conductivity of 1.182 E−4 S cm−1 with an activation energy of 0.273 eV at room temperature when the pH value of the precursor solution is adjusted to 6.0. Additionally, the assembled LiCoO 2 /LATP-6.0/Li all-solid-state coin cell delivers commendable cycling stability with a high discharge specific capacity of 150.5 mAh g−1 at 0.1 C after five activation cycles and retains a specific capacity retention rate of 94.28% after 300 cycles with various current densities at room temperature. Moreover, the LATP-6.0 solid electrolyte sheets maintain an intact morphology and uniformly-distributed elements composition after cycling. Based on these excellent results, the use of the LATP-6.0 sheets as solid electrolytes in high-performance all-solid-state lithium-ion batteries is a promising strategy. [ABSTRACT FROM AUTHOR]

This paper explores a hybrid- and two mono-nanofluids and, to be more specific, it deals with the effect of adding Silica (SiO 2) and Graphene (G) nanoparticles and their hybrid (G (30%) + SiO 2 (70%)) on viscosity of water. For all designed hybrid- and mono-nanofluids at various concentrations of 0.05–1%, viscosity was measured under the influence of temperature (25–50 °C). Meanwhile, for measuring the viscosity, different shear rates (12.23–122.3 s−1) have been applied to evaluate rheological behavior of nanofluids. The viscosity of hybrid nanofluids lies between the viscosity of mono nanofluids, while G/Water mono-nanofluid samples have the highest value. Experimental results revealed non-Newtonian pseudoplastic behavior for all three types of nanofluids, this behavior is more evident in the G/Water mono-nanofluid. Moreover, G-SiO 2 (30–70%)/Water hybrid nanofluid has a higher tendency to the behavior of SiO 2 /Water mono-nanofluid. Finally, via curve fitting method, two-variable correlations were proposed to estimate rheological behavior of G-SiO 2 (30–70%)/Water hybrid nanofluid. Unlabelled Image • Preparing novel nanofluids by adding Graphene and Silica nano-powders in distilled water • Performing characterization tests such as XRD, DLS, Raman and FESEM • Using chemical and physical methods to homogenize and stabilize nanofluid samples • Measuring viscosity for various concentrations under different shear rates and temperatures • Comparing the rheological behavior of hybrid- and mono-nanofluids [ABSTRACT FROM AUTHOR]

In recent years, microbial-induced carbonate precipitation (MICP) is becoming a popular method of soil stabilisation and concrete crack healing. In MICP, calcium is a necessary reactant, and pH value is a crucial factor for living bacteria. Both parameters (i.e., calcium and pH) are adjustable for geopolymer concrete mix design. Given the attractive potential for future applications of geopolymer concrete, understanding the impact of calcium content and pH value of MICP crack healing in geopolymer concrete mix design is of great importance. In this study, it was found that high calcium content in geopolymer concrete mix design is helpful to improve the healing effect. When CaO% in mix design increases from 7.5 % to 18.3 %, the healing degree increases. When Na 2 O% increases from 4.4 % to 11.6 %, the pH value of geopolymer concrete is improved by around 1, and it was also found that the impact of pH value depends on the way healing is implemented. In the case where bacteria were applied from outside of the healing surface cracks, the effect of pH value was almost negligible. However, when bacteria were used for internal healing, the lower pH value of the geopolymer mix design was beneficial for bacteria to provide a more suitable environment for bacterial activity and thus generate healing products. Therefore, the adjustment of calcium content and pH value in the geopolymer mix design can enhance the effectiveness of MICP crack healing for geopolymer concrete. [ABSTRACT FROM AUTHOR]

This study characterized the morphology, high-temperature property, rheological property, adhesion, cohesion, and chemical component of asphalt binder under aqueous solutions of different pH values. Then the physicochemical properties of asphalt binder were comprehensively evaluated by the improved radar chart. The properties of asphalt binder stripped layer-by-layer were explored to elucidate its gradient damage behaviors. The results indicate that the pH 3 solution reveals the greatest impact on the morphology of 90 asphalt (90 A) and styrene-butadiene-styrene modified asphalt (SBS MA), leading to the wide cracks on 90 A and the network cracks on SBS MA. The comprehensive assessment index of 90 A exposed to pH 3, pH 5, pH 7, pH 9, and pH 11 solutions can be reduced by 20.8%, 20.2%, 1.5%, 14.0%, and 25.5%, respectively. While for SBS MA, its corresponding values variation are 23.2%, 17.7%, 4.6%, 8.7%, and 13.0%, respectively. The acid solutions significantly affect the comprehensive properties of 90 A, but their pH value has little effect. 90 A exposure to the higher pH value of alkali solution reveals the worse comprehensive properties. Acid solute and alkali solute can aggravate the effect of aqueous solution on the comprehensive properties of SBS MA, and the degree of aggravation increases with the increase of solute concentration. The properties of asphalt binders exhibit varied gradient damage behaviors under different solute environments. The most serious damage occurs at 25–50 µm of 90 A and 0–50 µm of SBS MA. This study facilitates an accurate understanding of the mechanism of pavement distresses and composition design and construction utilization of asphalt binders. ● Asphalt samples were immersed in the aqueous solution with different pH values. ● The comprehensive properties and gradient damage behaviors were evaluated. ● Acid solutions with different pH values have similar erosion to asphalt binders. ● Alkali solutions with a higher pH value imply the worse properties of 90 A. ● The most serious damage occurs at 25–50 µm of 90 A and 0-50 µm of SBS MA. [ABSTRACT FROM AUTHOR]

The coupled system of column gel electrophoresis and inductively coupled plasma mass spectrometry (GE-ICP-MS) is a highly effective technique for detecting metal-binding proteins. However, it takes a long time for this method to test a single sample, which greatly limits its application. In this study, GE-ICP-MS system was optimized by adjusting the analytical conditions, including the concentration and pH of running buffer and the proportion of polyacrylamide gel. The results of the experiment showed that the migration speed of proteins in GE was enhanced by increasing the electrolyte concentration in the running buffer solution. Additionally, the ICP-MS response, which was dramatically decreased because of the change in running buffer solution, can be stabilized by adjusting pH of running buffer. Meanwhile, the optimization of polyacrylamide gel ratio allows GE-ICP-MS to maintain high resolution for proteins of similar molecular weight with increased detection speed. After increasing the concentration of running buffer by 10 times, four iodine labeled proteins were successfully separated at baseline by the GE-ICP-MS system at pH 8.0 in 40 min using a resolving gel (8%, 7 cm) and a stacking gel (4%, 1 cm), which was three times faster than the original one. Finally, the optimized method was proved by detecting a silver-binding protein in rat plasma samples. The above method provided an effective and rapid detection for metal-binding proteins in organism. [Display omitted] • Develop a rapid and practical method for analysis of metalloproteins with GE-ICP-MS • Accelerate migration of metalloprotein via increasing concentration of running buffer • Validate the method though analysis of silver-binding protein in rat plasma [ABSTRACT FROM AUTHOR]

DCB (OA, DSB, SB)-MMT complexes were prepared by incorporating zwitterionic surfactants dodecyl dimethyl carboxylbetaine (DCB), N,N-dimethyldodecylamine N-oxide (OA), dodecyl dimethyl sulfobetaine (DSB) and 3-sulphonyl hexadecyldimethylamine (SB) into montmorillonite (MMT). The complexes were characterized by XRD, FT-IR, TGA/DTA and SEM, TEM. Results indicated that the interlayer distances of OA (DSB)-MMT depended on surfactant content and pH value, while those of DCB (SB)-MMT were only related to the surfactant content. The different thermal decomposition processes of complexes were closely related with pH values. Then the pesticide (lambda-cyhalothrin (LCT) or beta-cypermethrin (BCT)) - DCB(SB) micelles were incorporated into the galleries of LCT/DCB-MMT and BCT/SB-MMT hybrids. The basal spaces of LCT/DCB-MMT and BCT/SB-MMT were 4.03 and 4.64 nm, which were larger than those of DCB-MMT and SB-MMT, respectively. The pesticide intercalation was further confirmed by FTIR and TGA/DTA. Furthermore, the release behaviors of BCT (LCT) from the hybrids were compared and analyzed. The pesticide hybrids have the slow release property due to the strong interaction between DCB(SB) and MMT. The pseudo second-order and parabolic diffusion models can be well used to fit the release data. The present study is conducive to the application of MMT as good carriers of pesticide delivery system. [Display omitted] [ABSTRACT FROM AUTHOR]

Here, Microcystis aeruginosa (M. aeruginosa) was studied to analyze the effects of 0.5 mg L−1 naphthalene and 0.05 mg L−1 phenanthrene on profiles of cell growth, chlorophyll- a content and Microcystin-LR (MC-LR) production at different pH values. The results indicated that for both the naphthalene and phenanthrene treatments, the specific growth rates were higher in pH 10.0 than in either pH 7.0 or pH 5.0. In the presence of low concentrations of naphthalene or phenanthrene, chlorophyll- a in medium increased significantly more in pH 10.0 than pH 5.0. chlorophyll- a in cell was significantly lowered when exposed to naphthalene in both pH 10.0 and pH 7.0, and was higher when exposed to phenanthrene in pH 10.0 than pH 5.0. HPLC analysis revealed that the extracellular MC-LR concentrations in M. aeruginosa exposed to either naphthalene or phenanthrene were lower than in control M. aeruginosa at pH 5.0. The intracellular MC-LR levels in toxic M. aeruginosa cells exposed to naphthalene or phenanthrene were higher than in the controls at pH 10.0. Our study suggests that the MC-LR production of M. aeruginosa was affected by the pH value when low concentrations of either naphthalene or phenanthrene were present in the water. These results indicate that the pH value should not be ignored when evaluating the risk of chemicals that promote MC-LR production in eutrophic waters. • The growth of M. aeruginosa was affected by pH value in the presence of Polycyclic Aromatic Hydrocarbons. • Chlorophyll- a in M. aeruginosa was affected by the pH value in the presence of Polycyclic Aromatic Hydrocarbons. • MC-LR production of M. aeruginosa was affected by the pH value and Polycyclic Aromatic Hydrocarbons. [ABSTRACT FROM AUTHOR]

Abstract Graphene oxides are prepared under various pH values and their photovoltaic performance is evaluated using conventional organic photovoltaic devices. Acidic pH values demonstrated graphene oxide with more oxygen-functional groups and lower surface areas but with broader pore size distributions than those in basic medium. The pristine graphene oxide organic photovoltaic shows slightly better photovoltaic performance mainly due to high short-circuit current density, while the graphene produced under neutral or acidic conditions are slightly less efficient. Graphical abstract We have demonstrated the influence pH value on PEDOT:PSS mixed graphene oxide on the photovoltaic performance of organic solar cells. fx1 [ABSTRACT FROM AUTHOR]

• The change of metal ions induced by pH value was different. • Iron plaque was closely related to absorption and uptake of heavy metals. • The uptake of heavy metals showed a pH-dependent manner by regulating the expression of metal transporters. The uptake of metal ions in soil depends primarily on the soil pH, but the effects of pH on individual heavy metals are not well understood. We found the effects of pH on rice uptake of heavy metals were quite different and the behavior of Zn and Cd were comparable, similar to Mn, but opposite of Fe. The concentration of Zn and Cd increased in plants when the pH was raised from 4.5 to 6.5, and then decreased at a pH of 7.5. Concentrations of Mn increased significantly when the pH was increased to 7.5. Iron plaque on root surfaces induced by high pH was likely related to the absorption and uptake of heavy metal elements, such as Cd and Zn, by the plant. Shoot Cd, Mn, and Zn concentrations were strongly positively correlated with DCB-extractable Cd (R2 = 0.98), Mn (R2 = 0.97), and Zn (R2 = 0.76) on the root surface. By contrast, Fe deposition on the root surface inhibited Fe uptake. Additionally, the pH-dependent expression of OsZIPs and OsNRAMPs affected metal uptake under different pH conditions, including OsZIP1 , OsIRT1 and OsNRAMP5. Using a genetic approach that used Osnramp 5 mutants, we revealed the regulation of OsNRAMP 5 expression is the primary factor affecting the concentration of Cd and Mn in rice under different pH. Collectively, our research indicates that the uptake of heavy metals was regulated by pH-depended iron plaque formation and expression of metal transporter genes in rice. [ABSTRACT FROM AUTHOR]

Abstract Nitrous oxide (N 2 O) is one of the most important greenhouse gases emitted by the semi-arid grasslands of Northern China. The majority of previous studies focused on nitrogen (N) deposition and its impacts on N 2 O emission rates in this region, while the mechanisms and controls of N 2 O emission and the evidence for a "balance point" following increasing N deposition remained unclear. In this study, we investigated during 2013–2015 the environmental and plant controls over N 2 O emission rates within a long-term N addition experiment with nitrogen levels of 1, 2, 4, 8, 16, 32, 64 g N m−2 yr−1, respectively, by using an in situ static chamber method. The results showed that N 2 O emission rates increased with increasing nitrogen addition rates. The emission rates showed significantly positive linear correlations with soil temperature, NO 3 −-N, NH 4 +-N, inorganic N, microbial biomass carbon, microbial biomass N, total soluble N, below-ground plant biomass and above-ground plant biomass, but a significantly negative correlation with soil pH. A structural equation modeling analysis showed that N addition affected in particular the pH value and subsequently N cycling and soil N 2 O emission. Meteorological factors impacted N 2 O emission rates through affecting soil environment and N cycling processes. The formulated "N 2 O emission balance hypothesis" was supported and the balance point at which the N 2 O emission rate became saturated was somewhere between 32 and 64 g N m−2 yr−1. The plant N usage efficiency was highest when the rate of N addition was 2 g N m−2 yr−1. The increased knowledge of environmental and plant control over soil N 2 O emission provides a better understanding of N cycling within the semi-arid temperate grassland ecosystem and will be fundamental for quantifying N 2 O budgets at various scales. Highlights • The first time of multi-levels effect of N on N 2 O emission in semi-arid grasslands. • The paper gives evidence for the existence of the N 2 O emission balance theory. • SEM results show the mechanism of N leading to increasing the N 2 O emission. [ABSTRACT FROM AUTHOR]

Abstract Lithium iron phosphate cathode materials for lithium ion batteries were synthesized successfully by hydrothermal synthesis method using LiOH·H 2 O and FeSO 4 ·7H 2 O as resources of Li and Fe, respectively. The X-ray diffraction, the scanning electron microscopy, the surface areas, the Fourier transform infrared spectra and electrochemical properties of LiFePO 4 /C cathode materials prepared at different pH values were investigated. The solubility product principle is reasonable to illustrate the chemical composition of the final products in the hydrothermal process. A full Rietveld refinement of X-ray diffraction patterns and Fourier transform infrared spectra results of pure LiFePO 4 /C prepared at pH 8, 9, 10 supports that cation mixing is the intrinsic characteristic of LiFePO 4 /C synthesized by hydrothermal process. The lithium diffusion kinetics is affected by the interaction between the occupation of Fe on Li sites and the diffusion path length. In the applied pH range, there is an optimal pH value of 10 for the formation, morphology, and lithium diffusion kinetics, and hence the best electrochemical performances of LiFePO 4 /C. The mechanisms of nucleation and crystal growth, the defect chemistry and the kinetic behavior are widely discussed in the study, and are essential for optimizing the properties of LiFePO 4. Graphical abstract Image 1 Highlights • Solubility product principle is reasonable to illustrate the chemical composition. • LiFePO 4 /C synthesized by hydrothermal process has cation mixing intrinsically. • Fe disorder and diffusion path length dominate Lithium diffusion kinetics. • There is an optimal pH value of 10 for electrochemical performances of LiFePO 4 /C. [ABSTRACT FROM AUTHOR]

Abstract To investigate the effect of different pH values (pH = 1, 3, 5, 7) of a solution used to prepare CaCu 3 Ti 4 O 12 (CCTO) ceramics on the microstructure and dielectric properties of the resultant ceramics, the acid regulator in the solutions was replaced with an alkaline regulator, ammonia water, and CCTO ceramics were prepared through a sol-gel method. The data show that the dielectric constants of the as-prepared samples maintained relatively high values in the frequency range from 1 to 107 Hz. In addition, the dielectric loss decreased to 0.028 at 103 Hz for the sample prepared at pH = 5. Moreover, the results reveal that the grain size, porosity and content of the CuO phase at the grain boundaries of the CCTO ceramics varied with the pH value. Our results indicate that using an alkaline regulator to adjust the pH value of the synthesis solution is an effective method for reducing the dielectric loss of CCTO ceramics. Highlights • The pH values of CCTO sol was adjusted by alkaline regulator from 1 to 7. • ε r for the sample prepared from the sol with pH = 5 maintained 2.87 × 104 at 1 kHz. • The tan δ for the sample prepared from the sol with pH = 5 was 0.028 at 1 kHz. • The tan δ decreasing may be attributed to the increasing R gb and lower porosity. [ABSTRACT FROM AUTHOR]

Abstract Aims The impaired angiogenesis is the major cause of diabetic delayed wound healing. The molecular insight remains unknown. Previous study has shown that high glucose (HG) activates Na+/H+ exchanger 1 (NHE1) and induces intracellular alkalinization, resulting in endothelial dysfunction. The aim of this study is to investigate whether activation of NHE1 in endothelial cells by HG damages the angiogenesis in vitro and in vivo. Methods and results We used western blot to detect the phosphorylations of both Akt and Girdin, and pH-sensitive BCECF fluorescence to assay NHE1 activity and pHi value, respectively. The angiogenesis was evaluated by measuring the number of tube formation in vitro, and blood perfusion by laser doppler and neovascularization by staining CD31 in vivo. Our results indicated that induction of intracellular acidosis (IA) increased p-Akt and p-Girdin in human umbilical vein endothelial cells (HUVEC). HG activated NHE1 and increased pHi value in a time-dependent manner, associated with the decreased phosphorylations of both Akt and Gridin, while inhibition of NHE1 by amiloride abolished the HG-induced reductions of p-Akt and p-Girdin. However, silence of Akt by siRNA transfection or pharmacological inhibitors (wortmannin and LY294002) bypassed IA-induced Girdin phosphorylation. Overexpression of constitutively active Akt abolished HG-reduced Girdin phosphorylation. In addition, upregulation of Akt or inhibition of NHE1 remarkably attenuated HG-impaired tube formation in HUVEC. In vivo study revealed that amiloride dramatically rescued hyperglycemia-delayed blood perfusion and neovascularization by augmenting ischemia-induced angiogenesis. Conclusion IA promotes ischemia-induced angiogenesis via Akt-dependent Girdin phosphorylation in diabetic mice. Highlights • Intracellular acidosis activated Akt in endothelial cells. • Hyperglycemia inhibits endothelial cell-mediated angiogenesis and the delayed recovery of blood perfusion in mice following hind limb ischemia through Akt dephosphorylation mediated by NHE1/pHi in vivo. [ABSTRACT FROM AUTHOR]

Abstract The interfacial tribo-chemistry significantly affects the tribological behaviors of polycrystalline diamond (PCD)/Si 3 N 4 , especially introducing acid solution. The results indicate that the friction coefficient rises with increased PH while Si 3 N 4 wears severer and then slighter. Besides, when the hydrogen ions were introducing in the testing environment, the hydrolysis reaction of Si 3 N 4 and oxidation reaction of PCD were promoted on the surfaces with the formation of Si-OH and C-OH. The tribo-pair surfaces absorded hydrogen ions by protonation reaction to form the double electron layer in this process, during which significantly affect the tribological behavior of Si 3 N 4. This work elucidates that the protonation effect of hydrogen ions and bridge effect of hydroxyls, leading to the friction and wear mechanism of PCD/Si 3 N 4. Highlights • The tribological behaviors of PCD/Si 3 N 4 at various pH values were evaluated. • The COF rises with increased pH while Si 3 N 4 wears severer and then slighter. • Hydrogen ions concentration affects chemical interaction, thus friction and wear. • The formation of Si-OH and C-OH promotes hydrolysis of Si 3 N 4 and oxidation of PCD. [ABSTRACT FROM AUTHOR]

Highlights • pH showed complicated effects on protein uptake to two PEI-grafted Sepharose. • Both capacity and uptake rate on high-charge resin showed up-down-up trends with pH. • Charge-reduced resin gave both maximal capacity (257 mg/mL) and uptake rate at pH 5.5. • The two resins showed high dynamic capacities at different pH or salt concentrations. • Dynamic capacities over 120 mg/mL were observed on charge-reduced resin at pH 5.5–8. Abstract Previously, we have studied protein adsorption behaviors on a series of poly(ethylenimine) (PEI)-grafted Sepharose FF, and a critical ionic capacity of PEI-grafted resins was observed, above which both protein adsorption capacity (q) and effective pore diffusivity (D e) increased drastically. Moreover, reducing the charge density of the PEI-grafted resins from an ionic capacity of 740 mmol/L (FF-PEI-L740) to 440 mmol/L (FF-PEI-R440) by neutralization of the amino groups of PEI chains with sodium acetate brought out a three-fold increase of D e value at pH 8. In this work, FF-PEI-L740 and FF-PEI-R440 were selected to investigate the complicated effects of pH on protein adsorption behavior using bovine serum albumin (BSA) as the model protein. It was found that, for FF-PEI-L740, both the q and D e values decreased significantly when pH decreased from 9 to 5.5, and then increased dramatically at pH 5, and finally decreased remarkably at pH 4.5. The results were considered due to the following causes: The decrease of pH from 9 to 5.5 led to a greatly increased electrostatic repulsion between the PEI chains due to the increased dissociation degree of PEI, which caused the increase in steric hindrance effects and decrease in the bound protein transport by chain delivery. At pH 5, which was near the p I of BSA (∼4.9), the presence of few protein charges greatly decreased the electrostatic hindrance effect on protein transport and the high charge density of FF-PEI-L740 provided extensively accessible binding sites and facilitated the happening of chain delivery as well. At pH 4.5, the net charge of BSA shifted to positive, likely charged with PEI, so the overall electrostatic repulsion greatly hindered protein uptake. For FF-PEI-R440, whose charge density was much lower than FF-PEI-L740, its q and D e values even increased mildly when pH decreased from 8 to 5.5, because its slightly-increased charge density did not cause much increased electrostatic and steric hindrance effects but provided more binding sites for protein adsorption. At pH 5, the few charges of BSA and the low charge density of FF-PEI-R440 could not afford enough electrostatic interaction for protein binding, resulting in significantly decreased q and D e values. Besides, column breakthrough experiments revealed that FF-PEI-R440 kept high dynamic binding capacity (DBC) (>120 mg/mL) at pH 5.5–8, while FF-PEI-L740 offered high DBC (>80 mg/mL) at pH 5, 7 and 8 with a higher salt concentration (100 mmol/L NaCl). These findings demonstrated the excellence of FF-PEI-L740 and FF-PEI-R440 in different conditions, and would help in the design and selection of suitable resins for high-performance protein chromatography. [ABSTRACT FROM AUTHOR]

Highlights • Effect of pH on particle agglomeration and optical properties NPSs are investigated experimentally and theoretically. • The dependent/independent scattering and their boundaries are investigated and demarcated for different conditions. • Effect of particle size distribution on the scattering coefficient is studied to account the impact of compact particle agglomerates. • In comparison to the other parameters, pH was found to be a dominant effect on the dependent/independent scattering in NPSs. Abstract Nanoparticle suspensions (NPSs) are used extensively to improve the thermal efficiency of different engineering systems because of their unique thermo-optical properties. NPSs have also been uses in coatings as they improve or alter the appearance of objects, where radiative and optical properties play a significant role. In all these applications, pH of a suspension has a significant impact on the particle agglomeration behaviour, and consequently on optical properties and then on radiative heat transfer. In the present study, the effect of pH on the agglomeration of TiO 2 NPSs is investigated. For this purpose, both the experimental and theoretical studies were carried out. In the experiments, the particle size distribution and the average (effective) particle size for the NPSs in different conditions (the pH and particle volume fraction) were measured using the dynamic light scattering (DLS) technique. The effects of different particle agglomerates under different pH values on the dependent/independent scattering are explored and the corresponding regimes are demarked for different conditions. The effects of particle agglomeration, particle size distribution and their contributions to the scattering coefficients are obtained using the UV–Vis-NIR spectroscopy technique. The results show that pH may have significant effect on the optical properties involving NPSs. Adjusting the pH value based on the isoelectric point of the nanoparticle is an efficient method when specific radiative properties are required for specific applications. Different regimes of the dependent/independent scattering can be obtained by changing the pH of a particular nanoparticle suspension. [ABSTRACT FROM AUTHOR]

Abstract Introduction The aim of this study was to compare the solubility and the change in pH of a tricalcium silicate–containing sealer (BioRoot RCS [BR]), a mineral trioxide aggregate–containing sealer (MTA Fillapex [MTA]), and an epoxy resin–based sealer (AH Plus [AH]) during a longer period of time. Methods The solubility test was carried out in accordance with ISO6876:2012. Three hundred eighty sealer samples (n = 10 per group) were stored for 6 months in double distilled water (AD) or phosphate-buffered saline (PBS). The solubility was determined on the basis of the mass difference in percent. The pH measurement was carried out on the basis of the experimental setup of the solubility test with the aid of an electrode pH meter. The results were evaluated for significance by using analysis of variance, Student-Newman-Keuls, and t test (P <.05). Results The highest solubility was found for MTA in AD (4.65% ± 1.17%), followed by BR in AD (3.88% ± 0.42%) (P <.05). Also in PBS, MTA (3.24% ± 0.7%) showed a higher solubility than BR (1.78% ± 0.5%) (P <.05). AH was virtually insoluble during the entire period (0.5% ± 0.5%) (P <.05). The pH decreased continuously over time for all samples. After 6 months, BR showed the highest pH in AD (pH 10.3), followed by MTA in AD (pH 8.8), BR in PBS (pH 7.5), AH in PBS (pH 7.3), MTA in PBS (pH 7.2), and AH in AD (pH 6.3). Conclusions The solubility of MTA was significantly increased compared with BR and AH. Storage in PBS significantly reduced solubility of MTA and BR. BR showed a higher pH in both AD and PBS than MTA in AD and PBS. AH did not cause any significant pH change. Highlights • This is the first study evaluating the solubility and pH of sealers for 6 months. • BioRoot RCS and MTA Fillapex were compared with AH Plus. • The solubility for BioRoot RCS and MTA Fillapex was significantly lower in PBS. • Despite a lower solubility of BioRoot RCS compared to MTA Fillapex, the pH BioRoot RCS was higher. [ABSTRACT FROM AUTHOR]

In the face of difficulties in separating similar metals from acidic wastewater, a new process is proposed to selectively separate metals from acidic wastewater by controlling potential. In this paper, the effect of pH value on precipitation ratio and separation efficiency is investigated. Through thermodynamic calculations, a 3D E -pH diagram of the Me-S-H 2 O system was plotted. The results reveal that rising pH value is helpful for metal precipitation, but high pH value may cause co-precipitation of metals impurity. The crystallinity and size of precipitates are obviously affected by pH value. Co can be effectively separated from Zn by xanthate precipitation under controlling potential, and the xanthate dosage is dependent on pH value. Mn-inclusions appear in Zn-precipitate due to high Mn 2+ concentration. The optimal pH value for Cu 2+ , Co 2+ , and Zn 2+ precipitation were 1, 2, and 2, respectively. Mn 2+ could be recovered by carbonate precipitation from the solution after Zn removal. Cu 2+ , Co 2+ , Zn 2+ , and Mn 2+ precipitation ratios reached to 99%. [ABSTRACT FROM AUTHOR]

The pH dependant interactions of dipolar proteins and mostly negatively charged polysaccharides are well described in literature for pure substances (e.g. bovine serum albumin, gelatine, sodium alginate). In this study, the interactions were transferred to anaerobic sludge supernatant from biogas plants as an example for complex biosuspension matrices. Anaerobic sludge supernatant is often due to downstream processing by e.g. membrane filtration, where high amounts of macromolecular organic substances lead to severe membrane fouling and low permeabilies. Decreasing pH-values shifted the zeta potential exhibited by the proteins, allowing electrostatic protein-polysaccharide interactions and the formation of coacervated complexes. Median particle diameters increased from < 1 µm in the original sample to 5–15 µm in the acidified sample. The sludge samples showed non-Newtonian, shear-thinning behaviour. Comparing original and acidified samples, ultrafiltration membrane flux increased by a factor of 1.4–2.6 after acidification. Flux improvement was in good accordance with fundamental transport mechanisms reported in literature. In conclusion, it was possible to improve the ultrafiltration performance significantly by transferring well-known pH-dependant biopolymer interactions to complex anaerobic sludge matrices. This can be useful in a number of applications, e.g. wastewater treatment in MBRs, and membrane driven nutrient recovery from biological suspensions like WWTP sludge, manure, or digestate from biogas plants. [ABSTRACT FROM AUTHOR]

Rhodobacter capsulatus is a photosynthetic bacterium with the ability to produce H 2 under photosynthetic condition. In this study, a new strain JL1 isolated from lake water was identified as Rhodobacter capsulatus by phylogenetic analysis of 16S ribosomal DNA (rDNA) sequence. Initial medium pH and l -glutamate (nitrogen source) concentration were optimized. At optimum pH 7.0 and 7 mmol/L l -glutamate, R. capsulatus JL1 could grow and produce hydrogen on the carbon sources of acetate, butyrate, glucose, xylose and fructose with the maximum substrate to H 2 conversion efficiencies of 67.5%, 26.6%, 46.1%, 46.2% and 46.6%, respectively. The maximum H 2 production rate, 124 ± 0.6 mL/(L·h), was obtained using 20 mmol-glucose/L as the carbon source. The addition of appropriate acetic acid to the tests with low concentration of glucose was able to improve the H 2 yield. Under the optimum operation parameters, the maximum H 2 yield and H 2 production rate of R. capsulatus JL1 from 16.4 g-corn straw/L-culture were 2966.5 ± 43.2 mL/L and 71.1 ± 4.5 mL/(L·h), while the chemical oxygen demand (COD) removal rate was up to 49.6%. This study indicates that R. capsulatus JL1 can serve as good candidate strain for H 2 production with organic waste water as well as effluent of dark-fermentation. [ABSTRACT FROM AUTHOR]

In this work, the effect of core size on the fluorescence emission properties of CdTe@CdS core@shell quantum dots was investigated under the condition of different shell thickness and pH values. Both CdTe and CdTe@CdS core@shell QDs were synthesized in aqueous phase by a simple method, whose optical features were characterized by absorption and fluorescence spectra. High resolution transmission electron microscopy (HRTEM) and X-Ray Diffraction (XRD) were utilized to study the structure and composition of the as-prepared QDs. We can conclude that a smaller initial core exhibits a greater potential for optimizing both fluorescence intensity enhancement and red shift. What's more, there is an optimal shell thickness for the strongest fluorescence intensity while a thicker shell contributes to a larger fluorescence red shift. The optimal pH value is 10.5 for the fluorescence intensity enhancement of the core@shell QDs and a higher pH value is an advantage to expedite the growth rate of CdS shell. [ABSTRACT FROM AUTHOR]