Pyroelectrometallurgical processing of bismuth-containing oxides

In this work, we substantiate and develop a general pyroelectrometallurgical technology for processing bismuth dross and oxides (the intermediate products of lead bullion refining by the Betterton-Kroll process) to obtain crude bismuth. The research focuses on bismuth dross (3–5% Bi; 80–85% Pb) remelted at 500–600°С in the presence of NaNO3 and NaOH, as well as the obtained alkaline melt (bismuth oxides, 1–5% Bi; 60–70% Pb). The conducted experiments allowed us to determine optimal parameters of the main steps of processing bismuth oxide, as well as the characteristics of obtained products. Reduction smelting of bismuth oxides at 1150°C (with the addition of sodium carbonate, quartz and fine coke in the amount of 66, 25 and 5% of bismuth oxides mass, respectively) is proposed, leading to bismuth lead formation. Its decoppering is carried out at 350–600°C with 2.0% sulfur (by its weight), added to the melt. We propose to carry out the alkaline treatment of the decoppered Pb-Bi alloy at 500oC in contact with sodium hydroxide, sodium nitrate and sodium chloride, taken in amounts up to 10.2, 8.3 and 1.4% by weight of bismuth lead, respectively. Subsequent electrolysis comprises electrolytic processing of purified Pb-Bi alloy ingots at 550oC. The electrolyte consists of a melt with the following composition, %: NaCl – 7, KCl – 35, PbCl2 – 18 and ZnCl2 – 40. As a result, two end products were obtained by the proposed bismuth oxide processing. The anodic product at the second stage of electrolysis, crude bismuth (yielded 1.1% by the weight of oxides) contains 93.62% Bi and 4.14% Pb, extraction from oxides amounts to 19.0% Bi and 0.1% Pb. About 1.2% Bi and 9.1% Pb of their initial content in the oxides are transferred to the cathodic product containing 0.033% Bi and 97.83% Pb (the yield equalled 5.1% of the oxides).

Non-Linear Curriculum Experiences for Student Learning and Work Design

Developing curriculum aligned with employment outcomes often includes linear design. However, students do not cognitively approach their education linearly, and economies do not fluctuate linearly. We should support students' natural non-linear approaches to education and employment. Chat bots that include non-linear presentation of text, short video clips, and images can help us design curricular experiences that mirror and personalize unique student cognition. As students navigate nudges of content within a chat bot on their phone or full-page views in an internet browser, the initial content will catalyze new questions and non-linear thinking for students to then explore their own employment related journeys. This will buttress students to be agents in their learning instead of objects of linear design. Machine learning models feeding chat bot learning journeys and experiences can help improve organic assessment for a constellation of employment preparedness outcomes and connection.

Hydrolysis of wheat straw hemicelluloses for maximum xylose extraction

The aim of the study is to select reaction conditions for hydrolysis of wheat straw with dilute sulfuric acid for maximum xylose extraction under mild conditions (at atmospheric pressure and temperature of 100°C). The authors found that maximum glucose yield (72.4-77.1 weight % of the initial content of hemicelluloses in wheat straw) is achieved at a concentration of H2SO4 2-3 weight % and the hydrolysis process duration of 5 hours. Analysis of the obtained hydrolysates showed that they contain cellulose (56.8-70.4 weight %), lignin (19.8-28.8 weight %) and hemicelluloses (2.8-15.3 weight %).

INFLUENCE OF THE CONTENT OF PHENOLIC COMPOUNDS ON THE TASTE CHARACTERISTICS OF FOOD CARROTS

Исследовано изменение содержания фенольных соединений при хранении корнеплодов столовой моркови 14 сортов, перерабатываемых на предприятиях Беларуси. Отбор образцов моркови осуществляли из специализированных овощехранилищ 1 раз в месяц в течение 5 мес. Содержание фенольных соединений определяли по методике, адаптированной авторами для матрицы моркови, на основе реакции окисления фенольных соединений реактивом Фолина–Чокальтеу и последующей фотометрией при длине волны 765 нм. Общую сумму фенольных соединений определяли в пересчете на феруловую кислоту. Установлено, что наименьшее количество фенольных соединений содержали свежеубранные корнеплоды моркови (2,10–7,21 мг/100 г в зависимости от сорта). После 5 мес хранения концентрация водорастворимых фенольных соединений в корнеплодах в зависимости от сорта составила 16,07–40,78 мг/100 г, что превысило исходное содержание в 2,9–7,5 раза. Содержание фенольных соединений в корнеплодах моркови повышалось неравномерно в течение хранения. В 6 образцах рост характеризовался линейной зависимостью с коэффициентами корреляции 0,95 Ј R2 Ј 0,99, в 8 – экспоненциальной (0,92 Ј R2 Ј 0,99). Ощутимая горечь во вкусе появилась во всех образцах корнеплодов моркови после 4 мес хранения. В 11 образцах наблюдалась корреляция 0,91 между показателем ощущения горечи и содержанием фенольных соединений. По совокупности оцененных показателей наиболее предпочтительными для переработки на сок прямого отжима являются сорта столовой моркови Витаминная-6, Белградо, Лявониха, Монанта, Нантская 4. The change in the content of phenolic compounds during the storage of table carrot root crops of 14 varieties processed at Belarusian enterprises has been investigated. Carrot samples were taken from specialized vegetable storages once a month for 5 months. The content of phenolic compounds was determined by the method adapted by us for the carrot matrix, based on the oxidation reaction of phenolic compounds with the Folin–Chocalteu reagent and subsequent photometry at a wavelength of 765 nm. The total amount of phenolic compounds is determined in terms of ferulic acid. It was found that freshly harvested carrot roots contained the least amount of phenolic compounds (2,10–7,21 mg/100 g, depending on the variety). After 5 months of storage, the concentration of water-soluble phenolic compounds in root crops, depending on the variety, was 16,07–40,78 mg/100 g, which exceeded the initial content by 2,9–7,5 times. The content of phenolic compounds in carrot roots increased unevenly during storage. In 6 samples, the growth was characterized by a linear dependence with correlation coefficients of 0,95 Ј R2 Ј 0,99, in 8 – exponential (0,92 Ј R2 Ј 0,99). Palpable bitterness in taste appeared in all samples of carrot root crops after 4 months of storage. A correlation of 0,91 between the feeling of bitterness and the content of phenolic compounds was observed in 11 samples. According to the totality of the estimated indicators, the varieties of food carrots Vitaminnaya-6, Belgrado, Lyavonikha, Monanta, Nanta 4 are. most preferred for processing into juice of direct extraction.

Evaluation of Soil S Pools under 23 Years of Maize Monoculture

Sulfur nutrition is a critical part of proper crop growth and development. In our study, biomass yields (BY) and S uptake were investigated on long-term maize monoculture on haplic luvisol soil during the 23 years of this trial, as well as changes in water extractable (Sw), adsorbed (Sads), mineral (Sav), and pseudo-total S (St) fractions. Treatments used in this study are: (1) Control (Cont); (2) ammonium sulfate (AS); (3) urea and ammonium nitrate (UAN); (4) UAN + phosphorus and potassium (UAN + PK); (5) UAN + phosphorus, magnesium, sulfur (UAN + PMgS); and (6) Fallow. Recently, the Mehlich 3 method started to be used in the Czech Republic to determine content of plant available S. Using this method, it was found that the content of S extracted by Mehlich 3 (SM3) closely correlates to Sav in both topsoil and subsoil (r = 0.958 in 1997 and 0.990 in 2019, both at p < 0.001). We also found that, on average, during the entire experiment, all treatments had increased yields over Cont (135–147%) and increased S uptake (291, 192, 180, and 246% of Cont for AS, UAN, UAN + PK, and UAN + PMgS, respectively). Examining the changes from 1997 to 2019 in topsoil (0–30 cm depth), we discovered a decrease of S content in Sw, Sads, Sav, and St fractions on all treatments to an average of 34.6%, 65.8%, 42.2%, and 78.6% of their initial values. The exception was AS treatment, which doubled its initial content in mineral fractions and maintained the same levels of St, and which we attribute to the very high dose of S on this treatment (142 kg ha−1 year−1). Using the simple balance method, AS and UAN + PMgS treatments lost 142.2 and 95.3 kg S ha−1 year−1 to other sinks, except plant uptake, from the entire soil profile (0–60 cm) during 23 years of experiment. Other treatments also show significant losses with the exception of Fallow. Given these results, it is clear that content of sulfur in soil is generally decreasing and attention should be paid mainly towards minimizing of its losses.

Evidence on the Bioaccessibility of Glucosinolates and Breakdown Products of Cruciferous Sprouts by Simulated In Vitro Gastrointestinal Digestion

Cruciferous vegetables are gaining importance as nutritious and sustainable foods, rich in phytochemical compounds such as glucosinolates (GSLs). However, the breakdown products of these sulfur-based compounds, mainly represented by isothiocyanates (ITC) and indoles, can contribute to human health. In the human digestive system, the formation of these compounds continues to varying extents in the different stages of digestion, due to the contact of GSLs with different gastric fluids and enzymes under the physicochemical conditions of the gastrointestinal tract. Therefore, the aim of the present work was to uncover the effect of gastrointestinal digestion on the release of glucosinolates and their transformation into their bioactive counterparts by applying a simulated in vitro static model on a range of brassica (red radish, red cabbage, broccoli, and mustard) sprouts. In this sense, significantly higher bioaccessibility of ITC and indoles from GSLs of red cabbage sprouts was observed in comparison with broccoli, red radish, and mustard sprouts, due to the aliphatic GSLs proportion present in the different sprouts. This indicates that the bioaccessibility of GSLs from Brasicaceae sprouts is not exclusively associated with the initial content of these compounds in the plant material (almost negligible), but also with the release of GSLs and the ongoing breakdown reactions during the gastric and intestinal phases of digestion, respectively. Additionally, aliphatic GSLs provided higher bioaccessibility of their corresponding ITC in comparison to indolic and aromatic GSLs.

Time Evolution of Microbial Composition and Metabolic Profile for Biogenic Amines and Free Amino Acids in a Model Cucumber Fermentation System Brined with 0.5% to 5.0% Sodium Chloride

Salt concentrations in brine and temperature are the major environmental factors that affect activity of microorganisms and, thus may affect formation of biogenic amines (BAs) during the fermentation process. A model system to ferment cucumbers with low salt (0.5%, 1.5% or 5.0% NaCl) at two temperatures (11 or 23 °C) was used to study the ability of indigenous microbiota to produce biogenic amines and metabolize amino acid precursors. Colony counts for presumptive Enterococcus and Enterobacteriaceae increased by 4 and up to 2 log of CFU∙mL−1, respectively, and remained viable for more than 10 days. 16S rRNA sequencing showed that Lactobacillus and Enterobacter were dominant in fermented cucumbers with 0.5% and 1.5% salt concentrations after storage. The initial content of BAs in raw material of 25.44 ± 4.03 mg∙kg−1 fluctuated throughout experiment, but after 6 months there were no significant differences between tested variants. The most abundant BA was putrescine, that reached a maximum concentration of 158.02 ± 25.11 mg∙kg−1. The Biogenic Amines Index (BAI) calculated for all samples was significantly below that needed to induce undesirable effects upon consumption. The highest value was calculated for the 23 °C/5.0% NaCl brine variant after 192 h of fermentation (223.93 ± 54.40). Results presented in this work indicate that possibilities to control spontaneous fermentation by changing salt concentration and temperature to inhibit the formation of BAs are very limited.

The Embassy of Good Science: A Community-Based Initiative to Strengthen Research Integrity and Ethics

"The areas of Research Ethics and Research Integrity (RE+RI) are rapidly evolving. Guidelines, standards, and laws have been drafted in many countries, regions and institutions. However, the regulatory proliferation does not necessarily yield clear guidance for practice: researchers often lack up-to-date and easily accessible information and guidance on how to apply principles and norms. The same is true for RE+RI evaluation committees, who lack easy access to case studies. The Embassy of Good Science is an online initiative to address these problems. The Semantic MediaWiki platform brings together, and makes smart connections between, relevant guidelines and regulations, cases and scenarios, and teaching materials. The platform provides practical information about how to apply norms and principles in every day practice and how to teach about them. For example, The Embassy contains cases and scenarios on researchers’ day-to-day dilemmas, a discussion forum where researchers can share experiences, and easily adaptable teaching resources. Developed in consultation with stakeholders, the Embassy is managed by the European funded EnTIRE project. The initial content has been gathered via systematic reviews and is continually added to and updated by users. In the long-term, The Embassy will be community-owned and sustainable. The Embassy primarily supports researchers and RE+RI committee members. The platform also presents the opportunity to compare RE+RI principles, norms and practices worldwide, facilitating mutual learning and making the diversity of the RE+RI regulatory framework apparent. In this session, we will describe and demonstrate The Embassy’s value for practice, education and policy. "