Static Air Atmosphere Research Articles

Palladium-Catalyzed Domino Cyclization/Alkylation of Terminal Alkynes: Synthesis of Alkynyl-Functionalized Azaindoline Derivatives

A novel palladium-catalyzed domino cyclization/alkylation of terminal alkynes was achieved for the synthesis of alkynyl-functionalized 3,3-disubstituted azaindoline derivatives under air atmosphere conditions. Various types of terminal alkynes, including aromatic alkynes, aliphatic alkynes, and ferrocene acetylene, can undergo the process successfully. The protocol provides a range of alkynyl-functionalized azaindoline scaffolds bearing a quarternary carbon center.

The behavior of Ca and its compounds in Si during the slag refining with CaO-SiO2-CaF2 system under air atmosphere

Abstract A simulative industrial processing, slag refining under open air atmosphere conditions, has been established to observe the removal efficiency of impurities from molten Si at 1823 K. The behavior of Ca and its compounds in Si are investigated. The results show that, CaSi2 is a key compound on removing Fe, Al, Ca and P from Si. Ca in molten Si is produced from the reaction between CaO and Si at the melting stage of slag and Si, as well as at the beginning refining period of around 10 min, which is largely depends on the net content of single CaO phase. With the temperature going down to 1303 K gradually, most of Si is solidified and Ca percentage is increased, then species CaSi2 phase is generated from the melt composed of 61.4 wt% Si, while Fe is precipitated at the boundary between phases CaSi2 and Si. Furthermore, it is determined that, part of P in Si is oxidized to PO43− not by SiO2 but by CaO to form CaO·P2O5 slag phase, the other is more likely to be reduced to CaxSiyPz than to Ca3P2. Therefore, a slag rich in CaO will be much easier to produce Ca in Si and more efficient to remove impurities by acid leaching.

Assessing the impacts of seasonal and vertical atmospheric conditions on air quality over the Pearl River Delta region

Air pollution is an increasingly concerning problem in many metropolitan areas due to its adverse public health and environmental impacts. Vertical atmospheric conditions have strong effects on vertical mixing of air pollutants, which directly affects surface air quality. The characteristics and magnitude of how vertical atmospheric conditions affect surface air quality, which are critical to future air quality projections, have not yet been fully understood. This study aims to enhance understanding of the annual and seasonal sensitivities of air pollution to both surface and vertical atmospheric conditions. Based on both surface and vertical meteorological characteristics provided by 1994–2003 monthly dynamic downscaling data from the Weather and Research Forecast Model, we develop generalized linear models (GLMs) to study the relationships between surface air pollutants (ozone, respirable suspended particulates, and sulfur dioxide) and atmospheric conditions in the Pearl River Delta (PRD) region. Applying Principal Component Regression (PCR) to address multi-collinearity, we study the contributions of various meteorological variables to pollutants’ concentration levels based on the loading and model coefficient of major principal components. Our results show that relatively high pollutant concentration occurs under relatively low mid-level troposphere temperature gradients, low relative humidity, weak southerly wind (or strong northerly wind) and weak westerly wind (or strong easterly wind). Moreover, the correlations vary among pollutant species, seasons, and meteorological variables at various altitudes. In general, pollutant sensitivity to meteorological variables is found to be greater in winter than in other seasons, and the sensitivity of ozone to meteorology differs from that of the other two pollutants. Applying our GLMs to anomalous air pollution episodes, we find that meteorological variables up to mid troposphere (∼700 mb) play an important role in influencing surface air quality, pinpointing the significant and unique associations between meteorological variables at higher altitudes and surface air quality.

Storability of ‘Conference’ Pear Under Various Controlled Atmospheres

In two consecutive experimental seasons it was investigated the storage capacity of ‘Conference’ pear (Pyrus communis, L.) under regular air (RA) and various controlled atmosphere (CA) conditions during six months at 0 °C (±0.3). The occurrence flesh browning (FB), core browning (CB) and cavity formation (CF) was evaluated at each 2‑months storage intervals and the ripening quality traits analyzed immediately at the end of storage period and after 7 days of shelf-life in air at 20 °C. The storage conditions were: RA; 0.5 kPa O2 + 0.5 kPa CO2; 1.5 kPa O2 + 1.5 kPa CO2, 2.0 kPa O2 + 1.0 kPa CO2; 3.0 kPa O2 + 6.0 kPa CO2 and 0.5 kPa O2 + 6.0 kPa CO2. After six months, ‘Conference’ pear was very susceptible to FB, CB and CF under CA-storage. The damages started to develop at the second month of storage, increasing continuously until end of storage period. At storage end, pear fruits kept under 0.5 kPa O2 + 6.0 kPa CO2 showed a dramatic high occurrence of FB, CB and CF with a severity index of 50.6, 45.3 and 27.1, respectively. The lowest incidences of FB, CB and CF were scored in fruits kept at 2.0 kPa O2 + 1.0 kPa CO2 with severity indexes of 1.1, 1.1 and 1.0, respectively. Flesh firmness, skin color, titratable acidity and total soluble solids were satisfactory under 2.0 kPa O2 + 1.0 kPa CO2. In conclusion, ‘Conference’ pear cannot be stored under O2 partial pressure lower than 2.0 kPa and CO2 higher than 0.5 kPa.

Arsenic Removal of Filters by Heat Treated Mixtures of Yellow Loess and Sand in One-Dimensional Column for Real Groundwater Treatment.

It is described that the arsenic (As) removal in real groundwater by filters in one-dimensional (1D) column (30 mm diameter × 240 mm height) using mixtures of heat treated yellow loess (YL) and sand is applied with consideration of water permeability. The effluent satisfies the concentration of <10 ppb drinking water regulation before As saturation with filters. Heat treated mixture of YL and sand under 4% H2/96% Ar condition result in higher As removal capacity than heat treated one under air atmosphere condition at 500 °C for 3 hours. It is due to more evolution of Fe3O4 phase in the mixture. In order to increase As removal efficiency significantly, α-Fe2O3 coated filters on mixture of YL and sand by hydrothermal treatment at 100 °C for 12 hours are utilized. It leads to highly enhanced As removal efficiency with little Fe ions leaching but half reduction of effluent rate, appealing as an alternative of practical As removal filters.

One-Pot Synthesis of Benzo[b][1,4]oxazins via Intramolecular Trapping Iminoenol.

A highly atom-efficient "one-pot" protocol has been developed to construct multisubstituted 2-hydroxy-benzo[b][1,4]oxazins starting from N-(2-hydroxylaryl)enaminones. This procedure comprises a PIDA-mediated intramolecular iminoenol tautomer trapping reaction, followed by Et3N-promoted aerobic oxidative ring construction. In particular, an O2 molecule from air served as the oxygen source of the hydroxyl group in the titled products. This reaction proceeded smoothly at room temperature under air atmosphere and metal-free conditions.

Development and lifespan duration of Drosophila melanogaster at the larval development under hypoxia and hyperoxia

Various environmental factors can affect metabolic processes, physiological parameters and the lifespan of the whole organism. Since aging can be considered as part of development in accordance with the "developmental theory of aging", we can assume that development duration correlates with adult lifespan. Understanding how organisms react to different concentrations of O2 is an area of intense scientific study. It is known that ambient oxygen level affects body size, growth and development rates, cell cycle duration in Drosophila melanogaster, but data on the impact on lifespan remain controversial. In this study, we studied the influence of hypoxia (10% O2) and hyperoxia (40% O2) at the larval stage of development on the duration of Drosophila development and lifespan. Drosophila kept in atmospheric air (21% O2) was used as control. At the imago stage all the flies were kept in atmospheric air conditions. The results were presented as survival curves and average and maximum lifespan were calculated. The development duration of Drosophila melanogaster, which were kept under hypoxia, increased by one day compared to control and did not change at hyperoxia. Average and maximum life span significantly decreased at hyperoxia (average – by 17% in males and 10% in females, maximum – by 17% in males, p&lt;0,001). Hypoxia in different ways influenced males and females. The average lifespan of males did not significantly change and the maximum – increased by 11% (p&lt;0.001). In females, hypoxia during development led to a decrease in average lifespan by 18% and in maximum life span by 8%. The data obtained during our investigation allow us to conclude that the concentration of oxygen in the environment at the stage of development of Drosophila affects their life expectancy at the stage of imago, which can be explained by epigenetic mechanisms. Hyperoxia at the developmental stage adversely affected the life expectancy of fruit flies, probably due to the adverse effects of free-radical processes. Sex differences in the effects of hypoxia at the developmental stage were revealed. In female flies, it led to negative effects, while in males development under hypoxic conditions extended life span, probably due to the phenomenon of hormesis.

About economic assessment of the ecological damage caused to the air basin in Russia

The paper analyzes the condition of atmospheric air on the basis of determining the dynamics of emissions structure by types of pollutants. Types of consequences from pollution of the air basin are considered. The paper also reviews approaches toward calculations of payments for emissions of harmful substances and economic assessment of ecological damage caused by the pollution of the air basin.

The issue on environmental assessment of air quality of residential areas near traffic flows

A significant role in ensuring comfortable living conditions in the urban environment is played by the competent organization of the transport and road complex, which is aimed at ensuring road safety, reducing the load on highways for car density and improving the efficiency of traffic in the city when performing planning and technological measures. At the same time, the current state of the city’s traffic flows as sources of increased chemical pollution of the air environment requires an increase in the distance from streets and roads to residential buildings. This distance should be normalized by chemical and physical indicators of the state of atmospheric air and should be taken into account when red lines are established. In this article we analyze: functional state of the city, road network, composition and intensity of traffic flows for Tyumen. The traffic flows of the city are concentrated mainly in the central part of it. A particularly critical situation is formed at the intersections of cargo-loaded main streets at the hours of maximum traffic intensity and on the main highways of the city. We substitute the provision of regulatory requirements for the chemical pollution level at a distance from the border of the carriageway to the border of residential buildings in order to achieve sustainable urban development.

Оценка состояния окружающей среды и обеспечения экологической безопасности в российской Арктике

Successful development of the whole country economy requires an increase in the rate of economic growth, including through the development and processing of natural resources of the Arctic, which can lead to negative effects on the environment. The Arctic macroregion plays an important role in protective the ecological balance of the planet. The sensitivity of Arctic ecosystems increases the likelihood of regional environmental problems becoming global. Therefore, ensuring environmental safety in the Arctic should be scientifically constructed and implemented on the basis of systematic measurements of a set of indicators of the environment state. The purpose of this study is the selection, justification and analysis of indicators in accordance with the goals to preserve the environment and ensuring environmental safety of the Arctic macroregion. Five main tasks aimed at improving the state of atmospheric air, water resources, preserving biodiversity, developing and implementing environmental innovations and neutralizing production and consumption wastes were identified on the base of analysis of strategic planning documents in the sphere of environmental protection of the Russian Federation. The most fully characterizing indicators were substantiated for each task. Analysis of a dynamic series of data on the proposed indicators made it possible to identify a number of environmental features in the regions of the Russian Arctic. Among them are a high level of atmospheric air pollution; insufficient wastewater treatment and weak savings in fresh water intake by enterprises; low supply of high-quality drinking water; a high level of waste generation from industry and consumption; a small proportion of protected areas in the total area in the Russian Arctic; a low level of introduction of environmental innovations. The obtained results can be used as a basis for developing recommendations for improving the efficiency of state policy in the Arctic in the sphere of ecology. The proposed balanced system of indicators allows not only to assess the state of the environment and ensure environmental safety in the Arctic, but also to characterize the effectiveness of implementing the main objectives of environmental policy in relation to the macroregion.

Enviroment-Friendly Synthesis of Nanocrystalline Nickel Oxide and Its Antibacterial Properties

This study reports an environment-friendly synthetic strategy to process nickel oxide nanocrystals. A mesoporous nickel oxide nanostructure was synthesized using an environmentally benign biomimetic method. We used a natural rambutan peel waste resource as a raw material to ligate nickel ions to form nickel-ellagate complexes. The direct decomposition of the obtained complexes at 700 oC, 900 oC and 1100 oC in a static air atmosphere resulted in mesoporous nickel oxide nanostructures. The formation of columnar mesoporous NiO with a concentric stacked doughnuts architecture was purely dependent on the suitable direct decomposition temperature at 1100 oC when the synthesis was carried out. The prepared NiO nanocrystals were coated on cotton fabric and their antibacterial activity was also analyzed. The NiO nanoparticle-treated cotton fabric exhibited good antibacterial and wash durability performance.

Оцінка впливу розвитку автомобілізації на стан атмосферного повітря Херсонської урбоекосистеми

Оцінка впливу розвитку автомобілізації на стан атмосферного повітря Херсонської урбоекосистеми

Scientific-practical results of monitoring anthropogenic influence upon environment of mining territories

The objective of this paper is to improve the ecological monitoring system and to take effective technological measures by way of wastes neutralization. The scientific-practical results of monitoring the anthropogenic influence upon the environment of mining-industrial territories were discussed. The global environmental problems of modernity are connected only with the anthropogenic pollution of the atmosphere. Pollution by hazardous substances at various enterprises harms health and disrupts the dynamic balance of natural systems. It is especially typical for mining-industrial region territories. The solution of the problem of environmentally optimal distributing resources for industrial enterprises of the mining-industrial region will allow making maximal profit from each enterprise by assumption of reducing anthropogenic influence upon environment up to the maximum permissible value, which is specified by normative documents. The patterns of formation of mining enterprises influence consequences on the atmosphere have been improved with the use of experimental and theoretical studies and in order to optimize the resources distribution for preventive measures, which can ensure the atmospheric safety of the mining-industrial region. The proposed methodological principles for a comprehensive assessment of the atmosphere of the mining-industrial region allow to implement an integrated approach to forecasting the intensity of atmospheric pollution, the economic efficiency of production and atmospheric air condition control, using the basic requirements of the environmental imperative for the territory under consideration.

Transporting 8 × 10 Gbps WDM Ro-FSO Under Various Weather Conditions

Abstract Radio overfree space optics (Ro-FSO) is a modern communication technique that promises a development future. In this paper, WDM Ro-FSO communication system has designed (10 Gbps×8λ) for transmissions 80 Gbps data rate via the largest possible distance under clear air, heavy rain, and heavy fog atmosphere conditions of FSO link, with test the best wavelengths performance of (193.1 to 93.8) THz that each one (wavelength) carry 10 Gbps by employ BER analyzer at receiver channels. The electric signals produced by phase shift keying (PSK) modulation technique modulated the information (10 Gbps) on RF signal (20 GHz). The results of transporting 80 Gbps were 5 km under clear air weather condition, 1.2 km under heavy rain, and 0.2 km under heavy fog condition. Finally, the different wavelengths that carry high-value data rate are tested by measurement of the BER and Q factor for each received channel, and the theoretical model of PSK modulation is analyzed.

Zr doping dependence of structural and magnetic properties of cobalt ferrite synthesized by sol–gel based Pechini method

Nanocrystalline CoZrxFe2−xO4 (0 ≤ x ≤ 0.3 in a step of 0.05) powders were synthesized by Pechini sol–gel method. The dry gel was grinded and calcined at 700 °C in a static air atmosphere for 1 h. Some tests such as thermo gravimetric analysis (TGA) combined with differential analysis (DTA), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM) were carried out to investigate the thermal behaviour, structural bonds identification, crystallographic properties, morphology and magnetic properties of the obtained powders. X-ray diffraction revealed a single-phase cubic spinel structure for all samples, where the crystallite size decreases; the lattice parameter simultaneously increases with substitution of Zr. The results of FE-SEM showed that the particle size is in the 20–70 nm range. The magnetic properties such as saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) were measured from the hysteresis loops. The greatest amount of saturation magnetization for CoZr0.05Fe1.95O4 sample was 67.9 emu·g−1.

Photoluminescent properties of Eu3+ -Eu2+ activated MAl2 Six O2x+4 (M=Mg, Ca, Sr, Ba) phosphors prepared in air.

In this paper, MAl2 Six O2x+4 :Eu2+ /Eu3+ (Eu2+ + Eu3+ = 2%, molar ratio; M = Mg, Ca, Sr, Ba; x = 0, 0.5, 1, 1.5, 2) phosphors with different SiO2 concentrations (the ratio of SiO2 to MAl2 O4 is n%, n = 0, 50, 100, 150, 200, respectively) were prepared by high-temperature solid-state reaction under atmospheric air conditions. Their structures and photoluminescent properties were systematically researched. The results indicate that Eu3+ ions have been reduced and Eu2+ ions are obtained in air through the self-reduction mechanism. The alkaline earth metal ions and doping SiO2 strongly affect the crystalline phase and photoluminescent properties of samples, including microstructures, relative intensity of Eu2+ to Eu3+ , location of emission lines/bands. It is interesting and important that the emission color and intensities of europium-doped various phosphors which consist of aluminosilicate matrices prepared under atmospheric air conditions could be modulated by changing the kinds of alkaline earth metal and the content of SiO2 .

Chemoselective and Catalyst-Free O-Borylation of Silanols: A Facile Access to Borasiloxanes.

This paper demonstrates the first highly chemoselective syntheses of various borasiloxanes from hydroboranes and silanols, achieved through catalyst-free dehydrogenative coupling at room temperature. This green protocol, which uses easily accessible reagents, allows for the obtaining of borasiloxanes under air atmosphere and solvent-free conditions.

Analysis of Kerch by Local Indicators of Sustainable Development

This article presents an analysis of the city of Kerch (Crimea Republic, Kerch Peninsula) in accordance with the local sustainable development indicators. The authors carried out the assessment of the existing environmental problems in the city which was necessary for the further development of the environmentally oriented infrastructure under various development scenarios. Due to the natural and economic factors, Kerch can develop both as an industrial and recreational centre of the peninsula. The analysis of the atmospheric air condition, use of water and energy resources and the waste management system was conducted. The presented results showed the presence of major environmental problems in almost all spheres.

Fullerene C60 derivatives as efficient sensitizers of oxidation under the mild conditions of atmospheric air

The ability of fullerene C60 and of its derivatives to sensitize oxidation of triphenylphosphine with atmospheric oxygen under sunlight illumination at room temperature was found. Reuse of fullerene conjugates did not lead to reduction in their reactivity; the conjugates were recovered unchanged from the reaction mixture. The use of a xenon lamp significantly shortened the time of the process.

Effects of atmospheric plasma treatment on adhesion and tribology of aromatic thermoplastic polymers

After cold plasma treatment of poly(ethylene terephthalate) and poly(ether‐ether ketone) surfaces by dielectric barrier discharge (DBD) under atmospheric (air) conditions, variations in surface chemistry, and morphology were investigated in relation with adhesion and tribological properties. According to XPS measurements, surface oxidation caused the formation of low molecular weight moieties of carboxylic acids. The latter resulted in more hydrophilic surfaces according to water contact angle measurements, with mainly a higher polar surface energy component. In parallel, the surface roughness of originally polished surfaces reduced due to flattening of local surface asperities after DBD. The DBD significantly improved the adhesive shear strength for different glue types in polymer/polymer and polymer/steel joints, while the best adhesion was observed for a two‐component epoxy type adhesive. Under dry sliding conditions, the coefficients of friction were lower after DBD compared to pristine samples only under mild sliding conditions (v = 0.05 m/s; p &lt; 1 MPa.m/s), while the higher normal loads caused an increase in coefficients of friction likely due to the higher contributions of surface deformation. Most interestingly, the lower coefficients of friction after DBD were observed under oil lubrication and after cleaning the sliding track (“run‐out” condition), due to the better retention of oil at the sliding surface for plasma‐treated polymers. POLYM. ENG. SCI., 58:E93–E103, 2018. © 2017 Society of Plastics Engineers