Polar lipids are linked to nanoparticles in xylem sap of temperate angiosperm species

Xylem sap of angiosperm species has been found to include low concentrations of polar lipids and nanoparticles, including surfactant-coated nanobubbles. Although the nanoparticles have been suggested to consist of polar lipids, no attempt has been made to determine if nanoparticle and lipid concentrations are related. Here, we examined concentrations of nanoparticles and lipids in xylem sap and contamination control samples of six temperate angiosperm species with a NanoSight device and based on mass spectrometry. We found (1) that the concentration of nanoparticles and lipids were both diluted when an increasing amount of sap was extracted, (2) that their concentrations were significantly correlated in three species, (3) that their concentrations were affected by vessel anatomy, and (4) that concentrations of nanoparticles and lipids were very low in contamination-control samples. Moreover, there was little seasonal difference, no freezing-thawing effect on nanoparticles, and little seasonal variation in lipid composition. These findings indicate that lipids and nanoparticles are related to each other, and largely do not pass interconduit pit membranes. Further research is needed to examine the formation and stability of nanoparticles in xylem sap in relation to lipid composition, and the complicated interactions among the gas, liquid, and solid phases in xylem conduits.

Electromagnetic Field as Agent Moving Bioactive Cations. A New Antimicrobial System in Architecture Technology

There is a new described antifungal system (GALVI) involving the moving of bioactive ions of Zn, Cu and Bi for the protection of cultural heritage objects such as buildings, sculptures and stretchers. There were two kinds of galvanic cells that were used: the first composed of a two-electrodes system, Zn, Cu, and second one composed of a three-electrodes system, Zn, Bi and Cu. Moreover, two-phase media are proposed with various kinds of rocks used in architectonical objects. Microorganisms inhabit the boundaries of two liquid and solid phases. This enables the investigation of the process of rock colonization. Possible applications of the suggested GALVI system are mentioned.

Effect of Different Pretreatments on Sludge Solubilization and Estimation of Bioenergy Potential

Most of the conventional treatments of waste-activated sludge (WAS) are devoted to their minimization and destruction. On the other hand, the biomass contained in WAS can be utilized as a valuable source of renewable carbon. In this study, the influence of different pretreatments (ultrasonication, chemical, thermal, and combined pretreatments) was explored for sludge solubilization. Effects of the pretreatments were investigated as a function of the solubilization of total solids (TS), volatile solids (VS), and chemical oxygen demand (COD). Concentrations of soluble carbohydrates and total nitrogen were also measured. The most effective pretreatment to hydrolyze sludge was found to be the combined alkali–thermal (pH 12, 75 °C) pretreatment method, leading to TS and vs. solubilization of 9.6% and 17.2%, respectively. Soluble COD, carbohydrates, total nitrogen, and proteins estimated in the liquid phase were 5235 mg/L, 732 mg/L, 430 mg/L, and 2688 mg/L, respectively. Thus, the alkali–thermal method could be used for efficient valorization of WAS. Moreover, the solid fraction from all pretreated samples was further subjected to thermogravimetric analysis to estimate its potential for bioenergy from its higher heating value (HHV), which was found to be in the range of 10–11.82 MJ/kg. This study can provide better insight into the efficient valorization of liquid and solid phases of sludge after pretreatment.

Thermodynamic Description of Dilution and Dissolution Processes in the MgCl2−CsCl−H2O Ternary System

Thermodynamic data on the properties of the water-based electrolyte systems are very valuable for fundamental physical chemistry and for industrial applications. The missing data both on the dilution and dissolution enthalpies for the ternary CsCl−MgCl2−H2O mixed electrolyte system were investigated by means of the calorimetry method. The dilution calorimetry was performed at 298 K for the set of solutions from diluted to concentrated at constant ratio Cs+/Mg2+=1.8. The relative partial molar enthalpies, ideal, total, and excess ones were calculated. By means of the dissolution calorimetry, the standard enthalpies of formation, the enthalpies, and entropies for the double salt formation from simple salts were evaluated. The results obtained indicate that entropy as the major factor affecting the formation of the joint compound, both in the liquid and solid phases. These data can be implemented in thermodynamic databases and allow for accurate thermodynamic calculations for the salts extraction from natural water sources and for its possible application as thermochemical energy storage.

Hydrometallurgical Processing of Spent Carbon Lining to Extract Valuable Components for Cryolite Production

The technique of mathematical modeling using the Selector software package has been applied to study the leaching of fluorine from the carbon part of the aluminum electrolysis cell spent lining. Based on the model obtained, the effects of the solvent (caustic soda Na2Oку) concentration and the ratio of liquid and solid phases in the pulp on the fluorine extraction have been assessed. The research object was the lining samples by the RUSAL Krasnoyarsk JSC. A thermodynamic assessment of the spent carbon lining components behavior during the alkaline processing has been performed with the introduction of three solvent concentrations into the model: 12.5, 17.5, and 25.0 g/dm3. According to the model solutions, the maximum fluorine extraction (up to 90 %) is achieved when using a reagent with the Na2Oку concentrations of 12.5 and 17.5 g/dm3 and a liquid to solid ratio of 8.5÷10:1. Using the model, the phase composition of the cake and the forms, in which fluorine remains in the solid residue (cake), have been determined. Laboratory studies confirm the convergence of the simulation results with the experimental data: solutions have been obtained to crystallize out cryolite (with fluorine and silica content of 50–53 % wt. and 0.11÷0.53 % wt., respectively), which is in demand in the electrolysis of cryolite-alumina melts.

PHASE EQUILIBRIA IN THE NaCl–CaCl2–CaO SYSTEM

The phase equilibria of the ternary system CaCl2 – NaCl – CaO in the area which enriched of calcium and sodium chloride were investigated by the methods of differential-thermal analysis and powder X-ray phase analysis. In the systems were determined the equilibrium concentration of calcium oxide and the composition of the phases, which at the same time exist in an equilibrium state at different temperatures. The surfaces of liquidus and solidus were established, the compositions of the sections of the ternary system CaCl2–NaCl–CaO were defined, which recommended for electrochemical reduction of refractory metal oxides (titanium, zirconium and other), which allow electrolysis in the temperature range from 550 to 1000 °С. Five polythermal sections of the NaCl – CaCl2 – CaO ternary system were studied. For each polythermal section the regions of existence of the liquid and solid phases were established. For each polythermal section state diagrams were constructed. Used X-Ray phase analyses it was established the compositions of liquid and solid phases for each polythermal sections. The phases of which the system consists were determined. At a constant ratio of components [NaCl]:[CaCl2] = 1.06 (mol.) in the melts of the ternary system CaCl2 – NaCl – CaO, the equilibrium content of calcium oxide reaches 12.0 mol.%, while their crystallization temperature does not exceed 550 °C. This allows us to recommend mixtures of this composition for electrochemical reduction of refractory metal oxides in a wide range of temperatures (from 550 to 1000 °C) with a high content of both calcium and sodium chlorides (not less than 40 mol.%) and oxide. calcium (up to 12.0 mol.%). The eutectic of this ternary system has a melting point of 480 ° C and corresponds to he composition (mol.%): CaCl2 (45.8) – NaCl (47.0) – CaO (7.2).

Solid-liquid phase equilibria in the ternary systems H2O+ZnCl2+NaCl at temperatures of 298, 313 and 333 K

In this study, an economic separation method was suggested with the use of phase equilibria in order to ensure the recycling of ZnCl2 whose industrial waste amount is very high and to prevent it to form an environmental pollution. Sodium chloride-zinc chloride-water systems were examined with the isothermal method at temperatures of 298, 313 and 333 K. The analyses of the liquid and solid phases were used to determine the composition of the solid phase using the Schreinemakers graphic method. The solid-liquid phase equilibrium and viscosity data belonging to all ternary systems were identified and the solubility and viscosity changes with temperature were compared. The viscosity values were inversely proportional to the temperature as the amount of ZnCl2 in the solution increased. NaCl, 2NaCl ZnCl2 nH2O (n: 2, 0), ZnCl2 salts were observed at 298, 313, 333 K in the solid phases which are at equilibrium with the liquid phase at the invariant point.

The methods of realization of ITS-90 fixed points: the necessity for improvement

The consistency of the results of international comparisons and the equivalence of national standards, improvement of methods for the realization of the International Temperature Scale ITS-90 main fixed points of metals freezing are considered. Two sources of uncertainty of the temperature value during realization of metals freezing fixed points have been determined. Experiments on the initiation of the inner interface between the liquid and solid phases of the metal have been carried out, the effect of the initiation conditions on the interface structure and measured temperature value in aluminum and indium fixed points cells has been investigated. The question of the correctness of the impurities influence estimates according to the laws for the only outer interface moving from the crucible walls to its center is considered. Analysis of the freezing curves obtained under different initiation conditions allowed determining the criterion for the presence of a continuous inner interface and the conditions for the formation of a single outer interface during slow crystallization of the metal without the formation of an inner interface. The obtained criteria will allow metrological institutes to choose the correct conditions for the initiation of the inner interface when using different designs of cells and heaters.

Furfural preparation using KHSO4 as the catalyst and its recovery and reuse

KHSO4 was used for furfural production, and the catalyst was recovered. The wet solid mixture after reaction was subjected to hot water washing and solid-liquid separation to recover the catalyst into the filtrate. Methods for determination of the catalyst content in both liquid and solid phases were invented. The effect of the mass ratio of hot water to the wet solid mixture, washing time, and number of washing times on the catalyst recovery were investigated. The total recovery of the catalyst into the filtrate was up to 87.7% when using the optimum conditions. The catalyst was reused in laboratory experiments up to 5 successive times. The recovered catalyst had the same activity for furfural production as the fresh catalyst on the same dosage level. Thermal gravimetric and X-ray diffractometer analyses of the catalyst showed that the catalyst was stable and reusable.