Study of Triple System Calcium Iodide-HMTA-Water

Research relevance: synthesis, physicochemical studies of complexes bioactivity with salts of biometals and organic ligands are of great interest for bio-coordination chemistry. Materials and research methods: isothermal method was used to study heterogeneous equilibria at 25 °C. The concentration limits of compounds existence and the types of their solubility have been established. Research objectives: to investigate compounds of hexamethylenetetramine with salts of biometals with organic ligands in order to reduce toxicity, increase the bioactivity and bioavailability of coordination compounds. Research results: concentration limits of compounds existence and types of their solubility have been established. Conclusions: in obtained complexes, HMTA ligand contains four equivalent electron donor nitrogen atoms.

Neutralizing Aminesin Boiler Steam and Humidified Indoor Air

Objective: The health and comfort of the indoor population have been impacted by the humidity. While people are increasingly spending more time indoors, the presence of pollutants and lack of proper humidification in indoor air have significant risk factors that may lead to multiple health problems. Methods: By applying the right air purification and/or humidification system, the adverse effects of poor indoor air quality can be minimized. Direct steam addition is a common technique to humidify the indoor air of a building. Carbon dioxide or other acidic process contaminants may dissolve in steam or steam condensate that will consequently decrease the pH and make it corrosive for the steam distribution system. To avoid that, neutralizing amines are added to steam that keeps the pH neutral or slightly alkaline(pH 7.5-9.0). However, neutralizing amines have some toxic effects. OSHA, FDA, and NIOSH prescribe maximum concentration limits for them in indoor air. The Central Utility Plant (CUP) of National Institutes of Health (NIH) uses a 50:50 blend of cyclohexylamine and diethylaminoethanol as neutralizing agents for the steam. Results: The CUP at NIH presents the results of monitoring the concentration level of amines through mass balance, online monitoring at specified location of the steam distribution system and field measurement in humidified indoor air at buildings on campus. Conclusion Through theoretical calculation backed up by field measurement, the amine concentration of indoor air is determined to be well below the FDA regulated limits.

Prevalence of Mycotoxins and Endotoxins in Total Mixed Rations and Different Types of Ensiled Forages for Dairy Cows in Lithuania

In this study, 119 samples of total mixed rations and different types of ensiled forage (maize and grass silage, and haylage) collected in 2019–2020 from dairy farms in Lithuania were analyzed to evaluate the quantitative occurrence of mycotoxins and endotoxins. Samples were analyzed using high-performance liquid chromatography (HPLC) with a fluorescent (FLD) and an ultraviolet detector (UV) of mycotoxins and a detection assay based on the ELISA technology for endotoxins. The study included toxins regulated within the European Union (aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON) and T-2 toxin) and nonregulated toxins (endotoxins). Mycotoxin analysis showed that 49.58% of the samples out of 119 were positive for AFB1, 52.11% for ZEA and DON, 55.47% for T-2 toxin and 84.04% for endotoxins. In the contaminated samples, the highest mean values of AFB1 and T-2 toxin were determined in the grass silage samples, while ZEA and DON–were determined in the maize silage samples. Maize silage samples had the highest ZEA and DON concentrations, exceeding the EU maximum permissible concentration limits. In the haylage samples, AFB1 mycotoxin exceeded the maximum concentration limits. The highest mean value of endotoxins was determined in the total mixed rations samples. This is the first study to provide information about the concentrations of mycotoxins and endotoxins in total mixed rations and different types of ensiled forages for dairy cows in Lithuania.

Study of Barium Iodide-Hexamethylentetramin-Water System

Research relevance in this article is based on study of heterogeneous equilibria in ternary aqueous systems BaI2 — (CH2)6N4 — H2O, as synthesized complexes can be used as an antibacterial drug in veterinary medicine. Materials and research methods: heterogeneous equilibria were studied by the isothermal solubility method at 25 °С. Concentration limits of compounds existence and their solubility types have been established. Research objectives: to determine chemical bond types between the complexing agent and the ligand, as well as the general laws of thermal decomposition of synthesized compounds. Research results: the solubility isotherm of the BaI2 — (CH2)6N4 — H2O system has been studied and compiled. Conclusions: effect of anions on complexation and composition of resulting compounds were revealed.

Preliminary sources identification of nitric oxide (NO) emissions in underground mine

Gas hazards in Polish underground mines are a major problem for the ventilation service. Ensuring appropriate environmental conditions is becoming increasingly difficult, especially with the introduction of new, more stringent restrictions on the concentration limits of harmful gases. According to [1], the most dangerous gases in underground mines are carbon monoxide, hydrogen sulfide, nitrogen oxides, c arbon dioxide, sulfur dioxide, and m e thane. T ogether with the introduction of new limit values for the above-mentioned gases by the European Union, it is necessary to accurately identify the sources of their emission in mine workings in order to select an appropriate reduction method. This article presents daily measurements of nitric oxide (NO) concentrations in the workings of one of the copper ore mines owned by KGHM Polska Miedź S.A. The measurement results were used for preliminary analysis of sources of gas emissions to underground workings. The analysis is carried out through a graphical interpretation of the measured values. Knowing the details of the technological processes carried out in the mine under consideration (blasting, diesel engine machines, natural oxidation of nitrogen to NO) the graphs were interpreted by assigning individual values of NO concentrations over time to a specific t echnological process.

POSSIBLE CAUSE OF ABNORMAL COLLAPSE OF THE WORLD TRADE CENTER BULDING

Национальный институт стандартов и технологий (NIST) провел расследование о причинах обрушения Всемирного торгового центра (WTC). Однако до сих пор встречаются суждения о якобы специально подготовленном взрыве зданий WTC некими «заговорщиками». Действительно, для многих наблюдателей и экспертов картина обрушения башен WTC послужила поводом для сомнений - как могли высотные здания относительно ровно, практически вертикально, обрушиться? В связи с этим, в работе обсуждается гипотеза, на основе которой можно объяснить специфический характер обрушения зданий. Лифтовые шахты в зданиях занимали 25% площади на плане. Они были сгруппированы в центре здания. Внутренний объем шахт для лифтов на протяжении 200 метров по высоте равен 120000 м3. Разлившийся авиационный керосин пропитал поверхности стенок лифтовых шахт и создал внутри смесь из паров керосина и воздуха. У керосина в три раза ниже поверхностное натяжение, чем у воды. Поэтому он легко смачивает почти любые поверхности, быстро растекается и пропитывает всё. Для керосина концентрационные границы взрываемости в смеси с воздухом находятся от 0,8 до 5,2%. Энергия паров керосина в лифтовых шахтах, равная нижнему концентрационному пределу взрываемости, эквивалентна 13000 кг ТНТ. При случайной искре происходит объемный взрыв паров керосина в лифтовых шахтах. Энергии взрыва достаточно для разрушения и последующего почти вертикального обрушения здания. The National Institute of Standards and Technology (NIST) has conducted an investigation into the causes of the collapse of the World Trade Center (WTC). However, there are still opinions about the allegedly specially prepared explosion of the WTC buildings by some “conspirators”. For many observers and experts, the picture of the collapse of the WTC towers gave rise to doubts - how could high-rise buildings collapse relatively evenly, almost vertically? The paper discusses a hypothesis on the basis of which it is possible to explain the specific nature of the collapse of these buildings. The elevator shafts were grouped in the center of the building. They occupied 25% of the area on the plan. The internal volume of the elevator shafts over a length of 200 meters in height is equal to 120,000 m3. The spilled aviation kerosene soaked the surfaces of the walls of the elevator shafts and created a mixture of kerosene and air vapors inside. Kerosene has three times lower surface tension than water. Therefore, it easily wets almost any surface, spreads quickly and soaks everything. For kerosene, the concentration limits of explosiveness in a mixture with air are from 0.8 to 5.2%. The energy of kerosene vapors in lift shafts, equal to the lower concentration limit of explosiveness, is equivalent to 13000 kg of TNT. In case of an accidental spark, a volumetric explosion of kerosene vapors occurs in the elevator shafts. The energy of the explosion was enough to destroy the building causing subsequent almost vertical collapse.

THE SUBSTITUTION OF REGULATED BROMINATED FLAME RETARDANTS IN PLASTIC PRODUCTS AND WASTE AND THE DECLARED PROPERTIES OF THE SUBSTITUTES IN REACH

Plastics containing brominated flame retardants (BFR) currently contain both “legacy” regulated and non-regulated BFR (R-BFRs and NR-BFRs), as evidenced by the increasingly lower correspondence over time between total bromine and R-BFRs content. The portion of substitutive NR-BFR present in the plastics and their toxicity and ecotoxicity properties are documented. Data relating to plastics and foam present in electrical and electronic equipment (EEE), waste EEE, vehicles, textiles and upholstery, toys, leisure and sports equipment show how 88% of plastic waste contains bromine from NR-BFRs. BFR substances mentioned in the catalogs of the three main producers (Albemarle, ICL, Lanxess) and BFR on the official used list of 418 plastic additives in the EU were gathered and the toxic and ecotoxic properties of these compounds as listed in their ECHA registration dossier were compiled. Fifty-five preparations using 34 NR-BFRs substances, including polymers and blends, were found. Seventeen of these substances featured an incomplete dossier, 12 were equipped with a complete dossier, whilst 11 substances (including 2 ill-defined blends) should be reassessed. Eight substances have been notified for assessment by the ECHA as persistent, bioaccumulative and toxic, or as endocrine disruptors, including decabromodiphenylethane; 3 substances display functional concentrations (the concentration of additives that retards flame) exceeding the concentration limits classifying a waste as hazardous but are “reactive” (they bind to the polymer). The technical limit of 2 000 mg total Br/kg indicated for further recycling (EN 50625-3-1) relates to all brominated substances and is relevant in the sorting of all poorly classified new substances.

Essential Oil Composition From Cryptomeria japonica D.Don Grown in Azores: Biomass Valorization From Forest Management

Cryptomeria japonica biomass was obtained monthly from forest lumbering operations at São Miguel, Terceira and Pico (Azores), between May 2018 and June 2020. C japonica stands with different ages (2 to ±50 years), grown in different soil types (lithosol and andosol) and at different altitudes (200 to >800 m) were used. The chemical composition of 118 C japonica essential oil (EO) samples, plus 1 sample from an EO solid deposit, were analyzed by gas chromatography and gas chromatography–mass spectrometry. Chemical composition cluster analysis showed 2 clusters, cluster I and II, with no chemical correlation. Cluster I grouped all 117 EO samples that resulted from extraction of branches and foliage with, or without, strobili, from strobili, and from the solid deposit sample. Cluster II grouped the 2 samples of EO isolated from wood, with a markedly different composition. Cluster I showed 5 subclusters (Ia-Ie). The degree of chemical correlation between the samples in these subclusters varied between moderate (subclusters Id and Ie), high (subclusters Ib and Ic), and very high (subcluster Ia). Of the 119 samples, 94 (79% of the total) were included in subcluster Ia, with 66 samples from São Miguel, 2 from Terceira, and 26 from Pico, showing a yield range from 0.1% to 0.4% (v/w). All these samples, with a high chemical correlation, were obtained by steam distillation from branches and foliage with, or without, female or male strobili, or both. This subcluster did not show any grouping pattern regarding the collection month, the altitude (200 to >800 m), the soil type (lithosol, andosol, or its subtypes), or the wood age (±30 to ±50 years). Subcluster Ia was characterized by the dominance of α-pinene (13%-43%), sabinene (5%-25%), phyllocladene (2%-22%), limonene (2%-16%), kaurene (traces-13%), elemol (1%-11%), and terpinen-4-ol (1%-7%). The determination of the concentration limits of the EOs representative components confirmed the homogeneity of C japonica EO, obtained from plant material collected in the 3 Azores islands, despite the variability in the range of some diterpenes that deserves further study. This study allowed for the determination of the concentration limits of the EOs representative components, with the purpose of adding value to C japonica EO, obtained from forest lumbering.