Enhanced desalination efficiency of flow-through capacitive deionization cell by mesh electrode with granular aerogel carbon in the removal of ions from synthetic and real samples

Flow-through capacitive deionization (FTCDI) is a traditional improved flow-by CDI cellular structure, used to remove ions from aqueous solutions. In this study, a new FTCDI was designed consisting of mesh electrodes (ME) containing ion-exchange membranes (IEM) and aerogel carbon granules with a specific surface area of 489 m2/g. All analyses and experiments performed showed that the new design can remove nitrate, phosphate, sodium, calcium, and chloride. Under optimal conditions, the new FTCDI system can remove 82.5, 49, 85, and 90% of sodium chloride, calcium chloride, nitrate, and phosphate with a maximum input concentration of 450 mg/L, 450 mg/L, 70 mg/L, and 3 mg/L, respectively. The efficiency of this system was also evaluated for real samples. Findings of the study showed that if the initial amount of turbidity is 12 NTU, total soluble solids (TDS) 1,700 mg/L, total hardness 540 mg/L, phosphate 0.09 mg/L, nitrate 28.8 mg/L, and electrical conductivity (EC) 3,480 μs/cm, the system can remove 25, 23.5, 33.3, 66.6, 54.4, and 39.1%, respectively.

Desorption Characterization of Methane in Coal with Different Moisture Contents and Its Influence on Outburst Prediction

Coal and gas outburst is a dynamic phenomenon with violent eruptions of coal and gas from the working coal seam. It has been proved that rapid desorption within a short period is necessary for the occurrence of an outburst. Due to the limitation of the present test condition, gas desorption characterization in coal with different moisture content for the first several seconds (0–60 s) has not been researched sufficiently. In this study, initial desorption characterization of gas in coal with different moisture content is studied by experiments with methane. The most remarkable characteristic of the experimental setup is the application of a self-developed real-time data acquisition system with a time interval of about 10 ms, which achieves the goal of collecting enough pressure data for analysis and calculation. The data is used to study gas pressure variation and calculate the initial amount of desorbed gas and index (ΔP) of initial velocity diffusion of coal gas. From the experimental results, the new proof has been found to verify that coal with lower moisture content and methane outburst is more dangerous than coal with higher moisture content and outburst. The degree of coal and methane outburst is exponentially decaying with increasing moisture content.

Learning retention in mathematics over consecutive weeks: Impact of motivated forgetting

<span>Retention is the ability to retain information in the mind, either in short-term or long-term memory. Memory in the long-term is more ideal. Thus, this has become a challenge for educators on how to transfer ideas in short-term memory to long-term memory. To concretize the effect of time on mathematics learning retention, a randomized pre-test post-test x groups design, using matched subjects was used in the study. Seven matched groups of students were identified, and took the pre-test as the basis of the initial amount of learning, after which a group of students was assigned to take the post-test every week for seven weeks. The post-tests results were the basis of the amount of retained learning of the students. The study found out that: i) The amount of retained learning among the students diminished following a negative exponential curve; ii) The amount of retained learning was comparably equal with the initial amount of learning up to the second week; iii) The amount of retained learning became incomparable with the initial amount of learning after the third week; and iv) The concepts in the knowledge level had a great chance to be remembered while the concept with analysis level was prone to motivated forgetting.</span>

Processing Dross from Hot-Dip Galvanizing by Chlorination Roasting

Dross from hot-dip galvanizing is an important source of pure zinc ingots and zinc oxide for use as mineral additives in animal and poultry feed. Thermodynamic calculations have shown the possibility of solving the issue of dross processing by roasting using CaCl2 and NH4Cl. The influence of the consumption of chlorinating reagents, the roasting temperature on the degree of sublimation of Pb, Fe, Ni, Cu and Cd has been investigated. It has been shown that the best results are achieved when roasting the dross with the simultaneous use of CaCl2 and NH4Cl in amounts of 6 and 15% by weight of the feed material. The optimal roasting parameters were established: T = 1000 °C, duration—60 min, air flow—0.1 L/min. Recovered pure zinc oxide composition (%) was: 0.05 Pb, 0.15 Fe, 0.06 Ni, 0.003 Cu and 0.001 Cd. The degree of sublimation of copper, nickel and iron chlorides was ~75%, with lead and cadmium at 90–98% of their initial amount in the dross.

A Rational Analysis on Key Parameters Ruling Zerovalent Iron-Based Treatment Trains: Towards the Separation of Reductive from Oxidative Phases

The development of treatment trains for pollutant degradation employing zerovalent iron has been attracting a lot of interest in the last few years. This approach consists of pre-treatment only with zerovalent iron, followed by a Fenton oxidation taking advantage of the iron ions released in the first step. In this work, the advantages/disadvantages of this strategy were studied employing commercial zerovalent iron microparticles (mZVI). The effect of the initial amount of mZVI, H2O2, pH, conductivity, anions and dissolved oxygen were analysed using p-nitrobenzoic acid (PNBA) as model pollutant. 83% reduction of PNBA 6 µM into p-aminobenzoic acid (PABA) was achieved in natural water at an initial pH 3.0 and 1.4 g/L of mZVI, under aerobic conditions, in 2 h. An evaluation of the convenience of removing mZVI after the reductive phase before the Fenton oxidation was investigated together with mZVI reusability. The Fenton step against the more reactive PABA required 50 mg/L of H2O2 to achieve more than 96% removal in 15 min at pH 7.5 (final pH from the reductive step). At least one complete reuse cycle (reduction/oxidation) was achieved with the separated mZVI. This approach might be interesting to treat wastewater containing pollutants initially resistant to hydroxyl radicals.

Researching the change in the weight of split oak firewood due to different drying methods

In this paper, the influences of stacking methods and drying places of split oak firewood in winter conditions (Quercus cerris) have been experimentally and theoretically investigated, due to the great importance of use in heating with such wood. The research was conducted on a sample of 48 pieces of logs with bark made of freshly cut oak. The logs were obtained by mechanized technology with the help of grafting by a hydraulic splitter and a chainsaw. Each log was measured for a research length of 0.30 m, marked with numbers 1-24. On each log, the weight was measured on a scale of 5 kg with an accuracy of 0.5 grams. Drying of logs was performed in two places. The first drying place was in outdoor conditions, sheltered from the snow and ventilated. The second place was indoors, at approximately constant room temperature. The logs were stacked in a crossed way for better air circulation. They were dried between 15/12/2020 and 15/02/2021, a total of 62 days. The average initial weight of logs dried in the facility was 1130.3 g, in the dried state the average weight was 952.87 g, which represented 84.3% of the original weight. The average initial weight of logs dried in outdoor conditions was 1192.125 g, in the dried state 1076.37 g, which represented 90.29% of the original weight. The average initial water content in the logs dried in the facility was 37.9%, in the dried state it was 27.5%. For logs dried in outdoor conditions, the average initial amount of water was 36.6%, in the dried state the average amount of water was 31.2%.

Assessment of Nanopollution in Water Environments from Commercial Products

The use of nano-enabled products (NEPs) can release engineered nanomaterials (ENMs) into water resources, and the increasing commercialisation of NEPs raises the environmental exposure potential. The current study investigated the release of ENMs and their characteristics from six commercial products (sunscreens, body creams, sanitiser, and socks) containing nTiO2, nAg, and nZnO. ENMs were released in aqueous media from all investigated NEPs and were associated with ions (Ag+ and Zn2+) and coating agents (Si and Al). NEPs generally released elongated (7–9 × 66–70 nm) and angular (21–80 × 25–79 nm) nTiO2, near-spherical (12–49 nm) and angular nAg (21–76 × 29–77 nm), and angular nZnO (32–36 × 32–40 nm). NEPs released varying ENMs’ total concentrations (ca 0.4–95%) of total Ti, Ag, Ag+, Zn, and Zn2+ relative to the initial amount of ENMs added in NEPs, influenced by the nature of the product and recipient water quality. The findings confirmed the use of the examined NEPs as sources of nanopollution in water resources, and the physicochemical properties of the nanopollutants were determined. Exposure assessment data from real-life sources are highly valuable for enriching the robust environmental risk assessment of nanotechnology.

Comparison of Longitudinal Changes in Refractive Error of Hyperopic Children with or without Refractive Accommodative Esotropia

We investigated longitudinal changes in the spherical equivalent refractive error (SE) in hyperopic children with or without refractive accommodative esotropia (AccET). A total of 456 patients met the inclusion criteria: 190 (41.7%) in the hyperopic control group and 266 (58.3%) in the AccET group. All patients received at least 3 years of follow-up after spectacle prescription. Subgroups were divided according to age when spectacles were prescribed, presence of amblyopia, or initial SE. Longitudinal changes in SE in children with hyperopia showed a gradual decrease, although SE of younger children with AccET increased over the first 4 years and then decreased thereafter. SE in eye with higher SE was tended to decrease significantly in patient with Acc ET than hyperopic control group (group × time p = 0.015). Amblyopic eyes showed a greater decreased in SE compared with non-amblyopic eyes, but it was not statistically significant (p = 0.07). SE was significantly decreased in children with more hyperopia (≥ 3 D) compared with children with less hyperopia (<3 D) (p = 0.008). Emmetropization of hyperopia was faster in hyperopic patients without AccET and could be affected by the age of the initial spectacles prescription, initial amount of SE, or presence of amblyopia.

Theoretical solution for drained cylindrical cavity expansion in clays with fabric anisotropy and structure

This paper presents a novel, exact, semi-analytical solution for the quasi-static drained expansion of a cylindrical cavity in soft soils with fabric anisotropy and structure. The assumed constitutive model is the S-CLAY1S model, which is a Cam clay-type model that considers fabric anisotropy that evolves with plastic strains, structure and gradual degradation of bonding (destructuration) due to plastic straining. The solution involves the numerical integration of a system of eight first-order ordinary differential equations, three of them corresponding to the effective stresses in cylindrical coordinates, other three corresponding to the components of the fabric tensor and one corresponding to the amount of bonding and another corresponding to the specific volume. The solution is validated against finite element analyses. When destructuration is considered, the solution provides slightly lower values of the effective radial and mean stresses near the cavity wall. Besides, the specific volume is further reduced due to loss of bonding. Parametric analyses and discussion of the influence of soil overconsolidation, expansion of the cavity and initial amount of bonding are presented.

COMPARATIVE ANALYSIS OF THE CONTENT OF CATECHINS IN FRUITS OF NEW VNIISPK BREEDING APPLE VARIETIES AND IN THEIR PROCESSING PRODUCTS

Apple is a supplier of raw materials for processing as a leader in industrial horticulture. Apple preserves keep to a large extent useful properties of fresh fruits. The aim of this study was to review multi-year data of catechin content in fruits and processing products of 36 new VNIISPK breeding apple varieties. The average content of catechin in fruits of new varieties was 141.9±4.9 mg/100 g while cultivar variation was from 91 mg/100 g in Ven'yaminovskoe to 243 mg/100 g in Zaryanka (V=21.0%). The catechin content in all types of processing was lower than in fresh fruits. The catechin content of processing products remained at an average of about a third of catechin quantity in apples. The catechin content decreased in series: juice→compote→preserves of apples and jam, since their preservation is greatly influenced by the increase in temperature during the processing of raw materials (r = -0.78 *). The absence of reliable direct correlation between the initial amount of catechin in the fruits and in the processing products confirms the importance of variety selection which keep a high level of catechin during processing.