Higher Activity Content Research Articles

Ultrahigh active material content and highly stable Ni-rich cathode leveraged by oxidative chemical vapor deposition

Despite the huge achievements that have been made in developing lithium-ion batteries, there remain gaps between the existing demands and the current battery performance. As one of the key components, cathode needs to adopt a further enhanced design to realize a high energy density and long useful life battery. Here we report a cathode tailoring strategy, exploiting multi-functional conformal coatings that are mechanically flexible, thickness controllable at the nanometer scale, electronically conductive, and selectively permeable. We demonstrate a gas phase polymerization technique that successfully enhances the energy density and the lifespan of the battery, particularly for a Ni-rich cathode (LiNi0.8Co0.1Mn0.1O2, NCM811). Oxidative chemical vapor deposition (oCVD) yielded an extremely conformal polymer layer of poly (3,4-ethylene dioxythiophene) (PEDOT) that is chemisorbed on both primary and secondary particles in NCM811 with identified S-O bonds. The chemo-physical adhesion between the cathode particles and the highly conductive nature of oCVD PEDOT permit a significant reduction of inactive materials inclusion in the cathode and enable a noticeable high active materials content (up to 99% in weight percentage). ToF-SIMS results identified that the formation of cathode electrolyte interphases, especially between primary particles, has been eliminated in the PEDOT coated sample. As a result, the cathode enabled by multi-functional oCVD PEDOT exhibited much higher capacity retention (about 80% after 300 cycles) compared with the pristine sample (about 6% only after 200 cycles). These results offer a single-step rational cathode design strategy that ensures high-energy density, long-life, and safe lithium-ion batteries.

Development of ginger, turmeric oleoresins and pomegranate peel extracts incorporated pasteurized milk with pharmacologically important active compounds

The purpose of this study is to develop pasteurized milk incorporated with pharmacologically important active compounds in ginger (Zingiber officinale), turmeric (Zingiber officinale) and pomegranate (Punica granatum) peel. The aim was to enhance human immunity with acceptable sensory properties in the final product and evaluating proximate composition, physiochemical properties and microbial acceptance. Plant extracts were incorporated to enhance immune responses while providing several health benefits due to their active compounds. To identify active compounds of plant extracts GCMS analysis was conducted and several pharmacological important compounds were identified. The sample was subjected to sensory evaluation by 5 point hedonic scale to analyze the sensory properties to select the best formulation for the product. The formulation of 300 ppm of ginger, 100 ppm of turmeric and 300 ppm of pomegranate was found to be significantly best at 5% level of significance. Proximate composition of fortified and normal milk was measured in first day of shelf life. Proximate composition of fortified sample includes moisture% (87.41 ± 0.45), Fat% (3.73 ± 0.06), Protein% (3.06 ± 0.44), carbohydrate% (4.73 ± 0.06) and ash% (0.69 ± 0.03) content. There was no significant difference (p > 0.05) between standard pasteurized milk and newly developed milk sample with respect to proximate composition except for ash content. When considering physiochemical properties of the fortified final product; antioxidant activity (40.615 ± 0.447) and gallic acid equivalent total phenolic content (0.532 ± 0.004) was significantly higher (p < 0.05). Antimicrobial properties of plant extracts against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans were checked using agar well diffusion method. All 3 extracts have shown inhibition towards selected pathogenic bacteria and fungi. Final product possesses antimicrobial properties, high antioxidant activity and total phenolic content. Thereby, it can be concluded this product has a considerably improved medicinal value than normal milk as it was incorporated with ginger, turmeric and pomegranate peel extracts.

Changes in content of bioactive constituents and antioxidant activity of riceberry after food processing and degradation kinetics during storage.

The effect of roasting temperature (70, 120, 140°C) and food processing (soaking, steaming, and roasting) on the content of bioactive constituents (total phenolic content, total flavonoid content, total anthocyanin, and γ-oryzanol) and antioxidant activity of processed riceberry were investigated. In addition, the degradation kinetics of bioactive constituents and antioxidant activity during storage were assessed using zero-order and first-order kinetic models. Results showed riceberry roasted at 120°C had the highest total anthocyanin content and antioxidant activity. In addition, riceberry obtained from roasting exhibited the highest bioactive compound and antioxidant activity. Besides, first-order kinetic was confirmed as the best-fitted model to describe degradation of bioactive constituents and antioxidant activity of processed riceberry during storage. This finding suggested that roasting at 120°C was chosen as an optimum condition to maximize the content of bioactive constituents and antioxidant activity and kinetic models provided a better understanding of antioxidant property reduction of processed riceberry during storage. PRACTICAL APPLICATION: Riceberry is an abundant source of bioactive constituents with beneficial health effects leading to a development of functional food product. However, processing may negatively affect biological properties of riceberry and bioactive constituent degradation of processed riceberry during storage has not been previously reported. Therefore, different processes were investigated to determine the effect on bioactive constituents and antioxidant activity of riceberry, and the degradation kinetic model of bioactive constituents during storage was also studied. Optimum processing is appropriate to design riceberry containing high concentration of bioactive constituents and antioxidant activity, which could be considered as a functional diet for health-conscious consumer.

Radon groundwater in a radon-prone area: possible uses and problems: an example from SW part of Kłodzko Valley, Sudetes, SW Poland

The paper describes research aimed at expanding scientific knowledge of radioactive isotope 222Rn occurrence in groundwaters flowing in crystalline rocks, including its spatial and temporal changes. The research, conducted in an area characterized by medium radon potential, was intended to determine the values of 222Rn activity concentration in groundwater in this type of areas. The 222Rn activity concentration in groundwaters discharged from investigated springs oscillated between 35.3 and 272.0 Bq/L. The authors discovered possible prevalence of radon groundwaters in areas with medium radon potential, which is the reason why all groundwaters intended for human consumption or household use in such areas should be subject to obligatory monitoring of 222Rn activity concentration. In the event of identifying occurrence of waters with 222Rn activity concentration of at least 100 Bq/L, their purification by removing radon is necessary before they are supplied to a water distribution network. At the same time, the research area can be regarded as an area with potentially medicinal radon water occurrence. Therefore, in areas with medium radon potential, groundwaters which are not suitable as a source of drinking water due to very high 222Rn activity concentration in them can be used as medicinal radon waters in therapeutic treatments.

Feasibility of mapping radioactive minerals in high background radiation areas using remote sensing techniques

This study investigates the utility of using remote sensing and geographic information system techniques to accurately infer the presence of radioactive minerals in a typical high background radiation area (HBRA) by analyzing spectral signatures of associated soil, rocks and vegetation. To accomplish this, both unsupervised (K-Means Clustering) and supervised classification techniques based on a maximum likelihood classifier (MLC) were applied to Landsat-8 Imager data from Mrima Hill on Kenya's south coast. The hill is surrounded by dense tropical forest and deeply weathered soils which are rich in Nb, Th, and rare earth elements. Due to high activity concentrations of 232Th (>8 times higher than the world average value for soil), the hill has been designated as a geogenic HBRA. Based on the underlying geological formations, four classifications of vegetation and two classifications of soil/rocks were established and used to indicate the presence of radioactive minerals in the area. Measurements of air-absorbed gamma dose-rates in the area were successfully used to validate these findings. The application of the MLC method on Landsat satellite data shows that this method can be used as a powerful tool to explore and improve radioactive minerals mapping in HBRAs, the overall classification accuracy of Landsat8 OLI data using botanical technique is 80% and the Kappa Coefficient is 0.6. The overall classification accuracy using soil/rocks spectral signatures is 91% and the Kappa Coefficient is 0.7. Finally, the study demonstrated the general utility of remote sensing techniques in radioactive mineral surveys as well as environmental radiological assessments, particularly in resource-constrained settings.

Quality attributes of nance (Byrsonima crassifolia) fruits as affected by storage temperature and maturity at harvest

Nance (Byrsonima crassifolia) fruit is harvested when natural abscission from the plant occurs. At this stage, the shelf life is less than 5 d in ambient conditions. The aim of the present work was thus to determine how quality attributes of nance fruits are modified as a function of ripening on the tree, physiological condition at harvest, and storage temperature. Fruits at three maturity stages (green, transient, and yellow) were harvested and stored at 15 and 25°C. As fruits ripened, the hue angle turned to yellow, and lightness and chroma increased, but carotenoid content decreased. The contents of total soluble solids, total sugars, and reducing sugars increased; however, the total soluble phenols, flavonoids, and antioxidant activity decreased. It was possible to harvest at a physiological stage previous to abscission maturity even though a non-climacteric pattern was identified. Handling of transient nance fruits at 15°C extended shelf life for more than 15 d, with adequate physical and compositional attributes including high concentration of bioactive compounds and antioxidant activity. Content of total soluble solids was identified as an attribute suitable for developing a harvest index for nance fruits.

Refining the conceptual model for radionuclide mobility in groundwater in the vicinity of a Hungarian granitic complex using geochemical modeling

Groundwater is an important freshwater resource, which can be affected by geogenic radionuclide contamination. To make decisions regarding the use and management of groundwater, understanding the controls of radionuclide mobility is critical. In the southern foreland of a granitic outcrop in Hungary, high gross alpha activity concentration was measured in drinking water wells, related probably to the presence of uranium. It has been suggested that understanding of the groundwater flow system may be a key aspect to understand uranium mobility in groundwater. The goal of the present work was to elucidate the conceptual model of radionuclide mobility in the study area, focusing in particular on the geochemical controls of uranium. For this purpose, water samples were collected and nuclide-specific measurements for 226Ra and radon isotopes were carried out, in addition to 234U+238U measurements, to increase the range of radionuclides and better understand their mobility. A geochemical modeling analysis involving redox-controlling kinetic reactions and a surface complexation model was developed to support the conceptual model. The results from the sampling indicate that excess of 234U+238U (3–753 mBq L−1) contribute to the natural radioactivity measured in drinking water to a large degree. 226Ra was measured in relatively low activity concentrations (<5–63 mBq L−1) with the exception of three specific wells. Notable radon activity concentration was measured in the springwaters from Velence Hills (1.01–3.14 × 105 mBq L−1) and in interrelation with the highest (285–695 mBq L−1) 226Ra activity concentrations. The geochemical model suggests that uranium distribution is sensitive to redox changes in the aquifer. Its mobility in groundwater depends on the residence time of groundwater compared to the reaction time controlling the consumption of oxidizing species. The longer the flow path from the recharge point to an observation point where U is measured, the more likely it is that reducing conditions will be found in the aquifer and the elemental concentration U will be low.

Uranium isotopes in food and effect on health of Southern Kazakhstan citizens

ABSTRACT Natural uranium isotopes were determined in food products of the Kyzylorda region in Kazakhstan. This region is characterised by the influence of the uranium industry, as up to 15% of the world uranium reserves are concentrated in this part of Kazakhstan and the adjacent territory of Kyrgyzstan. The food products most consumed by locals were selected for this survey. Special attention was paid to the analysis of edible and non-edible parts of food products and the assessment of a possible increase in risk due to consumption of non-edible parts. The highest content of uranium, of 80.2 µg/kg, was found in the edible part of the carrot. The highest activity concentrations of uranium isotopes are found in carrot, potato and onion, as edible parts of these vegetables are grown in the soil. All estimated cancer risks for uranium isotopes range from 10−14 to 10−12, which are insignificant values.

Determination of natural radioactivity, hazard parameters and physico-chemical properties of soils from Palakkad-Thrissur district, Kerala, India

Assessment of natural radioactivity (226Ra, 232Th, and 40K) and related radiation hazards play an important role in human health research and have received much attention from worldwide researchers. Soil is one of the key sources of human exposure to ionizing radiations. There has recently been a growing demand for soil data and information. This study aims to assess the radioactivity concentration and related parameters in the environment of Kuthiran hills due to radionuclides in soil samples collected from various locations around the Thrissur-Palakkad Highway (NH-544) regions in Kerala state (India). The activity concentrations of soil samples were determined by a gamma ray spectrometry system consisting of a p-type HPGe detector, with relative efficiency of 40%. The mean activity concentrations of 226Ra, 232Th and 40K were found to be 47.24 Bqkg−1, 67.49 Bqkg−1, and 810.87 Bqkg−1, respectively. These values are well within the permissible range, as recommended by the UNSCEAR 2008. The soil samples with the highest activity concentrations were primarily found in the valley region. The calculated hazard indices were used to estimate the potential radiological health risk from the soil, and the dose rates associated with it are significantly lower than their permissible limit. The overall findings indicate no radiological threat to the population's health in the study area.

Investigation of Radioactivity Levels and Lead in Soil and Shore Sediment from Port Said, Egypt

Soil is one of the foremost vital foundations of life for humans, animals, and plants, so the soil contamination by radionuclides is a dangerous threat of human health. This study investigated the ²²⁶Ra, ²²⁸Ra, ⁴⁰K, ¹³⁷Cs and pb to assess their risks in soil cover of Port Said governorate. So, 41 samples (29 soil samples and 12 shore sediment samples) were collected to cover the districts area, beaches and industrial areas in Port Said governorate. Activity concentrations of ²²⁶Ra, ²²⁸Ra, ⁴⁰K and ¹³⁷Cs were determined by Hyper-Pure Germanium detector, and their Pearson’s coefficient correlations were calculated and to assess the effects of radiation produced from these radionuclides, their hazards indices were estimated. Pb was determined using Ionized coupled plasma optical emission spectroscopy (ICP-OES), Geo-accumulation index (I-geo) and Contamination Factor (CF) were calculated. The activity concentration of soil for ²²⁶Ra, ²²⁸Ra, ⁴⁰K and ¹³⁷Cs ranged from 2.78 to 26.88, BDL to 19.69, BDL to 382.34 and BDL to 1.14 Bq/Kg with average values 11.59, 7.53, 218.77 and 0.25 Bq/Kg respectively. The activity concentrations of shore sediment for ²²⁶Ra, ²²⁸Ra, ⁴⁰K and ¹³⁷Cs ranged from 5.48 to 15.17, BDL to 11.75, BDL to 448.48 and BDL to 1.14 Bq/Kg with average values 10.16, 6.91, 364.23 and 0.38 Bq/Kg respectively. The highest activity concentrations and values of hazard indices are around the industrial facilities in both cases of soil and shore sediment samples as a result of contamination from factories. But the average activity concentration of ²²⁶Ra, ²²⁸Ra, and ⁴⁰K in the soil and shore sediment samples are still lower than the worldwide activity concentrations average values and the Egyptian activity concentrations mean values. Also, all values of hazard indices and their average values are below recommended values by UNSCEAR 2000. Geo-accumulation Index (I-geo) and Contamination Factor (CF) for Pb indicated that more than 2 thirds of soil and 80% of shore sediment samples are moderately polluted or considerably contaminated by Pb. Pearson's Correlation indicated that pb from side and ²²⁶Ra, ²²⁸Ra and ⁴⁰K from other side may be from different sources.

Measurement of Gross Alpha and Beta Activity Concentrations in Drinking Water from Sabon Gari Local Government Area of Kaduna State, Nigeria

The gross alpha and beta activity concentrations of eighteen water samples, consisting of boreholes and Hand-dug wells from Sabon Gari Local government area of Kaduna StateNigeria have been analyzed using, the potable single channel gas free MPC-2000B-DP detector. The results show that alpha and beta activity concentrations range from 0.96 × 10-2 Bq/L to 47.00 ×10-2 Bq/L and from 0.309 × 10-2 Bq/L to 310.40 × 10-2 Bq/L, for gross alpha and gross beta respectively. It is observed that in the overall samples, the gross alpha activity concentrations were below the 0.5 Bq/L maximum allowable limits for drinking water as recommended by World Health Organization (WHO). However, for the gross beta activity concentration, eleven (11) percent of the samples, have their activity concentrations greater than the 1.0 Bq/L maximum allowable limits for drinking water as recommended by the WHO. This high beta activity concentration in these areas might be due to the waste generated from industries and hospitals or as a result of the nature of farming activities occurring in the areas. Largely, results obtained are seen to be in agreement with reports from other authors within and outside Nigeria.

3D printed high-performance sodium ion and zinc ion full batteries

3D printing has unique advantages for the preparation of batteries. It is of great significance to 3D print sodium ion full batteries and aqueous zinc ion full batteries in view of the fact that they are very promising among post-lithium-ion batteries. Here, a facile 3D-printing strategy is proposed to fabricate sodium ion full batteries and aqueous zinc ion full batteries via the polymer-based inks with high active material content. The prepared electrode inks can be easily scaled up and have the shear thinning behaviors. Electrochemical analyses confirming that the 3D printed sodium ion full batteries and aqueous zinc ion full batteries both deliver high electrochemical performance. The former composed of sodium vanadium phosphate (Na3V2(PO4)3) cathode and anode delivers the high capacity (21 mAh g−1), high-rate capability (10 C), and long cycle stability (4000 cycles). Meanwhile, the latter constituted by vanadium dioxide (VO2(B)) cathode and zinc powders anode also reveals the high capacity (173 mAh g−1), high-rate capability (73 mAh g−1 at 1600 mA g−1), and long cycle stability. This 3D printing strategy provides a way to construct ultra-micro batteries, large-size batteries, and special-shaped batteries.

Unveiling the extreme environmental radioactivity of cryoconite from a Norwegian glacier

This study is a first survey of the occurrence of artificial (137Cs, 241Am, 207Bi, Pu isotopes) and natural (210Pb, 228Ac, 214Bi, 40K) radionuclides in Norwegian cryoconite. Cryoconite samples were collected before (12 samples) and after (5 samples) a rainfall event, after which 7 cryoconite holes dissapeared. The concentrations of radionuclides in cryoconite samples from the Blåisen Glacier are compared with data from the Arctic and Alpine glaciers. Cryoconite samples from the studied glacier had extremely high activity concentrations of 137Cs, 241Am, 207Bi and 239+240Pu (up to 25,000 Bq/kg, 58 Bq/kg, 13 Bq/kg and 131 Bq/kg, respectively) and also high concentrations of organic matter (OM), comparing to other Scandinavian and Arctic glaciers, reaching up to ~40% of total mass. The outstandingly high concentrations of 137Cs, 241Am, Pu isotopes, and 207Bi on the Blåisen Glacier are primarily related to bioaccumulation of radionuclides in organic-rich cryoconite and might be enhanced by additional transfers of contamination from the tundra by lemmings during their population peaks. The presumed influence of intense rainfall on radionuclide concentrations in the cryoconite was not confirmed.

The use of total diet study for determination of natural radionuclides in foods of a high background radiation area

The activity concentrations of 40K, 210Pb, 210Po, 226Ra, 228Ra, 228Th, 230Th, 232Th, 234U, and 238U were determined in 82 food samples, grouped into 20 food groups according to the Brazilian Total Diet, which reflects the dietary habits of a population, for the rural and urban areas of Poços de Caldas city, a High Background Radiation Area. The highest activity concentration found in the food samples was due to 40K being present in all types of food. Among the other radionuclides, high activity concentrations were found for 210Pb in beans and salt, 210Po in fish, 226Ra and 228Ra in nuts and seeds. The main food groups that contributed most to the effective dose, in urban and rural regions, were beans and beverages. The effective doses, due to the ingestion of the analysed food groups, were of 0.44 and 0.60 mSv y−1 and the lifetime cancer risks were 1.6 × 10−3 and 2.3 × 10−3 for the urban and rural Poços de Caldas population, respectively.

One-pot synthesis of MnO-loaded mildly expanded graphite composites as high-performance lithium-ion battery anode materials

Improving the properties of conventional graphite anode materials has been an important research topic for enhancing the performances of lithium-ion batteries (LIBs). Herein, we develop a facile one-pot approach to mildly expand graphite (MEG) and simultaneously load MnO onto the as-prepared MEG to synthesize MnO@MEG composites as high-performance anode materials for LIBs. With the improved porous structure and electrical conduction network, both the MEG and MnO components of the composite exhibit well-defined electrochemical properties and alleviated volume changes upon charge/discharge, synergistically enhancing the electrochemical performances for our composites. With a high active material content and high mass loading for the testing electrode, the optimized MnO@MEG composite shows a high capacity (437.77 mAh g−1 at 0.1 C), a high rate capability (capacity retains 71.93% at 1 C vs. 0.1 C), and a high cycling stability (capacity retains 73.17% and 68.13% after charge/discharge at 0.5 C and 1 C, respectively, for 50 cycles), significantly outperforming its pristine graphite counterpart and previously reported similar MnO composites with other carbon materials, thereby standing for a practically promising anode material for LIBs. Broadly, the one-pot approach developed in the present work can be extended for producing other graphite-based composites for other energy-related technologies.

Graphdiyne-like Porous Organic Framework as a Solid-Phase Sulfur Conversion Cathodic Host for Stable Li-S Batteries.

As a unique branch of Li-S batteries, solid-phase sulfur conversion polymer cathodes have shown superior stability with fast ion-transfer kinetics and high discharge capacities owing to the mere existence of short-chain sulfur species during charging/discharging. However, representative compounds such as sulfurized polyacrylonitrile (SPAN) and polyaniline (SPANI) suffer from low sulfur contents and poor cycling performances under large current densities due to the sulfurization occurring only on polymers' surface. Here, a graphdiyne-like porous organic framework, denoted as GPOF, is synthesized and used as a host for enabling solid-phase sulfur conversion. Plenty of unsaturated bonds in GPOF provide sufficient reaction sites to bind sulfur chains, resulting in a high active sulfur content in the cathode. Moreover, the microporous GPOF possesses suitable cavities to accommodate the volume expansion, leading to favorable long-term cycling stability. As a result, the sulfurized GPOF cathode (SGPOF-320) displays outstanding electrochemical stability with negligible capacity decline after 250 cycles at 0.2 C with an average discharge capacity of 925 mA h g-1. Our work applies a facile procedure to produce sulfur conversion porous polymer cathodes, which could provide a proper way for exploring more suitable cathode materials for high-performance Li-S batteries.

Effect of hot air temperature on drying kinetics of palmyra (Borassus aethiopum Mart.) seed-sprout fleshy scale slices and quality attributes of its flour

This study investigated the influence of different drying air temperatures (40, 50, 60 and 70 °C) on moisture removal ratio and drying rate of pre-cooked and uncooked palmyra ( Borassus aethiopum ) seed-sprout fleshy scale (SFS) slices and quality of the resultant flours. Through drying kinetic analysis, it was found that the drying process of pre-cooked and uncooked palmyra SFS slices took place in the falling rate period and the drying time decreased with increasing air temperature in all samples. The colour parameters (L*, a* and b*) were affected by the drying air temperature and treatment type (pre-cooked and uncooked), with significantly higher ΔE values in uncooked samples compared to the pre-cooked samples. Drying of uncooked SFS slices maintains relatively high total antioxidant activity and low content of vitamin C compared to the pre-cooked samples. Beta-carotene, total phenol and total flavonoid contents however showed no specific trend in pre-cooked and uncooked SFS samples. Generally, pre-cooking palmyra SFS before drying significantly (P ˂ 0.05) improved their water absorption capacity, swelling index and swelling capacity while decreasing bulk density. However, treatment type and drying air temperature was observed to greatly (P ˂ 0.05) influenced all pasting properties without any observable trend. Based on the results, the quality of palmyra SFS flour showed opposite behaviours, thus indicating a compromise decision on processing conditions involved to meet the quality properties of interest. • Pre-cooked and uncooked palmyra seed-sprout fleshy scale (SFS) were dried at 40–70 °C. • Drying rate of pre-cooked and uncooked palmyra SFS took place in the falling rate period. • Colour values of both pre-cooked and uncooked palmyra SFS were affected during drying process. • Uncooked palmyra SFS retained higher antioxidant activity and lower vitamin C compared to pre-cooked samples. • Pre-cooking of palmyra SFS before drying improved WAC, SI and SC while decreasing bulk density.

(Invited) Characterizing Redox Flow Battery Electrolytes Using Microelectrodes

Electrochemical energy storage is anticipated to play an important role in decarbonizing the electric power sector by facilitating the deployment of intermittent renewable power sources (e.g., solar photovoltaics, wind) and supporting an aging grid infrastructure [1]. Redox flow batteries (RFBs) are a promising electrochemical technology for energy-intensive grid storage, but further cost reductions are needed for widespread adoption, spurring research efforts into new redox chemistries and reactor designs. The recent emergence of engineered molecules offers intriguing new pathways to low cost energy storage through tunable molecular structures and inexpensive synthesis routes [2]. While the rapid and continued advancement of these redox couples is exciting, iterative design-test-improve cycles are slowed as molecules become increasingly robust and failure modes become more subtle, challenging traditional methodologies. Thus, there is a growing need for sensitive diagnostic techniques capable of evaluating materials performance under conditions that mimic those expected in practical embodiments [3]. In this talk, I will describe our recent efforts to develop voltammetric techniques to characterize candidate redox electrolytes, quantify electrochemical properties, and monitor electrolyte stability [4]. We primarily leverage microelectrodes, which offer several distinct advantages over traditional macroelectrodes, such as differentiation between oxidative and reductive signals and minimization of ohmic and capacitive distortions. Microelectrodes also yield more reliable electrochemical characterizations of electrolytes with high active species concentrations and varying states of charge. I will highlight efforts to track electrolyte state of charge and state of health within operating flow cells and to develop flexible modeling frameworks to assess electrolytes across a wide range of conditions. Incorporation of these techniques into experimental campaigns may aid in the development of next-generation RFB technologies.

Radon potential mapping in Jangsu-gun, South Korea using probabilistic and deep learning algorithms

The adverse health effects associated with the inhalation and ingestion of naturally occurring radon gas produced during the uranium decay chain mean that there is a need to identify high-risk areas. This study detected radon-prone areas using a geographic information system (GIS)-based probabilistic and machine learning methods, including the frequency ratio (FR) model and a convolutional neural network (CNN). Ten influencing factors, namely elevation, slope, the topographic wetness index (TWI), valley depth, fault density, lithology, and the average soil copper (Cu), calcium oxide (Cao), ferric oxide (Fe2O3), and lead (Pb) concentrations, were analyzed. In total, 27 rock samples with high activity concentration index values were divided randomly into training and validation datasets (70:30 ratio) to train the models. Areas were categorized as very high, high, moderate, low, and very low radon areas. According to the models, approximately 40% of the study area was classified as very high or high risk. Finally, the radon potential maps were validated using the area under the receiver operating characteristic curve (AUC) analysis. This showed that the CNN algorithm was superior to the FR method; for the former, AUC values of 0.844 and 0.840 were obtained using the training and validation datasets, respectively. However, both algorithms had high predictive power. Slope, lithology, and TWI were the best predictors of radon-affected areas. These results provide new information regarding the spatial distribution of radon, and could inform the development of new residential areas. Radon screening is important to reduce public exposure to high levels of naturally occurring radiation.

RP-HPLC-DAD determination of the differences in the polyphenol content of Fucus vesiculosus extracts with similar antioxidant activity

Significant quantities of bioactive compounds have been found in the chemical composition of seaweeds. This source of natural antioxidants such as polyphenols appears to attenuate lipid peroxidation caused by oxidative stress, preventing the harmful effects of a number of injuries including ischemia–reperfusion (I/R). Conventional extraction (CE) has been used for years as a traditional method for obtaining bioactive components from seaweeds. However, recent studies highlight ultrasonic-assisted extraction (UAE) as an alternative and more eco-friendly technique. Therefore, the two methods were optimised and compared to obtain a Fucus vesiculosus extract (FVE) with high antioxidant activity and polyphenol content. The highest antioxidant activity was obtained after 1 h at 25 °C for conventional extraction, and after 5 min at 35 °C for ultrasonic-assisted extraction. Higher concentrations of polyphenols were obtained with the optimal conditions in conventional extraction (13.61 mg PGE/g seaweed), but no significant differences were observed between the antioxidant activity obtained with UAE (89.33%) and CE (89.74%). The characterization of the polyphenols present in both optimised extracts was carried out and compared with reverse-phase high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD). The following compounds were identified: phloroglucinol, gallic acid, catechin, vanillic acid, epicatechin, protocatechuic acid, rutin, gentisic acid, chlorogenic acid, caffeic acid, coumaric acid and ferulic acid. RP-HPLC-DAD results also showed higher concentrations of polyphenols in optimised extracts with CE. Consequently, CE was found to be more effective than UAE in providing extracts with higher concentrations of polyphenols, but UAE constitutes an efficient and more eco-friendly methodology for obtaining a FVE with the highest antioxidant activity.