molecular nitrogen
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2022 ◽  
Author(s):  
Ulysse Dubuet ◽  
Pierre Mariotto ◽  
Christophe O. Laux ◽  
Marie-Yvonne Perrin

2022 ◽  
Author(s):  
Caiting Feng ◽  
Panfeng Wu ◽  
Qinlong Li ◽  
Jiquan Liu ◽  
Danjun Wang ◽  
...  

Photo-driven nitrogen fixation involves the activation and hydrogenation processes of molecular nitrogen at the surface of photocatalyst in producing ammonia. Herein, significantly enhancement of catalytic efficiency is achieved via constructing...


2021 ◽  
Vol 11 (24) ◽  
pp. 11930
Author(s):  
Viktoras Papadimas ◽  
Christos Doudesis ◽  
Panagiotis Svarnas ◽  
Polycarpos K. Papadopoulos ◽  
George P. Vafakos ◽  
...  

In the present work, a single dielectric barrier discharge (SDBD)-based actuator is developed and experimentally tested by means of various diagnostic techniques. Flexible dielectric barriers and conductive paint electrodes are used, making the design concept applicable to surfaces of different aerodynamic profiles. A technical drawing of the actuator is given in detail. The plasma is sustained by audio frequency sinusoidal high voltage, while it is probed electrically and optically. The consumed electric power is measured, and the optical emission spectrum is recorded in the ultraviolet–near infrared (UV–NIR) range. High-resolution spectroscopy provides molecular rotational distributions, which are treated appropriately to evaluate the gas temperature. The plasma-induced flow field is spatiotemporally surveyed with pitot-like tube and schlieren imaging. Briefly, the actuator consumes a mean power less than 10 W and shows a fair stability over one day, the average temperature of the gas above its surface is close to 400 K, and the fluid speed rises to 4.5 m s−1. A long, thin layer (less than 1.5 mm) of laminar flow is unveiled on the actuator surface. This thin layer is interfaced with an outspread turbulent flow field, which occupies a centimeter-scale area. Molecular nitrogen-positive ions appear to be part of the charged heavy species in the generated filamentary discharge, which can transfer energy and momentum to the surrounding air molecules.


2021 ◽  
Author(s):  
Ilya Zyatikov ◽  
Valery Losev ◽  
Vladimir Prokopev

2021 ◽  
Vol 12 (3) ◽  
pp. 383-390
Author(s):  
S. Y. Kots ◽  
L. I. Rybachenko ◽  
T. P. Mamenko ◽  
K. P. Kukol ◽  
P. P. Pukhtaievych ◽  
...  

Insufficient water supply is one of the main factors that significantly reduce the activity of nitrogen fixation by legume-rhizobial symbiotic systems. That is why comprehensive research on aspects of their resistance to water stress and the search for scientifically substantiated ways to improve the existing ones and develop modern, competitive technologies of growing legumes in arid conditions are becoming especially relevant. The aim of the work was to investigate the processes of formation and functioning of soybean-rhizobial symbiotic systems developed under conditions of different water supply and influence of nanocarboxylates of cobalt, ferum, germanium, chromium, сuprum and molybdenum. The nanoparticles of specified metal nanocarboxylates were used as components of the inoculation suspension of rhizobia of Tn5 mutant B1-20 for soybean seed treatment. A model drought lasting 14 days was created by controlled irrigation. Microbiological and physiological research methods were used in the study. We determined that insufficient water supply caused a significant decrease in the nodulation potential of rhizobia and the intensity of molecular nitrogen fixation by symbiotic systems formed with the participation of soybean plants and nodule bacteria without adding these metal nanocarboxylates to the inoculation suspension. Application of most of the metal nanocarboxylates used as components of the inoculation suspension mitigated the negative impact of stress on the investigated parameters. The study revealed the stimulating effect of cobaltnanocarboxylate on the activity of molecular nitrogen fixation, which was more pronounced in the conditions of insufficient water supply. Symbiotic soybean systems formed with the participation of nodule bacteria containing germaniumcarboxylate nanoparticles were proved to be the least sensitive to the negative impact of insufficient water supply. This was indicated by high rates of nodulation and nitrogen-fixing activity compared with other studied symbiotic systems. We confirmed that the addition of chromium nanocarboxylate to the inoculation suspension of rhizobia provided the highest rates of nodulation and nitrogen-fixing activity of soybean root nodules under optimal growing conditions and, at the same time, had no noticeable positive effect under water stress. We determined that сuprum and molybdenum nanocarboxylates, as components of the inoculation suspension, regardless of the water supply level, had a less notable positive effect on the processes of nodule formation and nitrogen fixation, and in some cases even led to a decrease in the investigated values for control plants. Thus, the study demonstrated that the use of germanium, cobalt and ferum nanocarboxylates as components of the bacterial suspension helped to increase the adaptation of the formed legume-rhizobial symbiotic systems to water stress, as evidenced by the maximum indexes of nodulation and molecular nitrogen fixation in the context of insufficient water supply and recovery of their level to optimal after the stress influence had ended. Based on the results, it was concluded that inoculation of seeds by the complex bacterial preparations made on the basis of Bradyrhizobium japonicum B1-20 with a content of germanium, cobalt and ferum nanocarboxylates in the concentration of 1:1000 can become one of the important means in soybean growing technologies of increasing the nitrogen-fixing potential and resistance of plants to insufficient water supply.


2021 ◽  
Vol 845 (1) ◽  
pp. 012110
Author(s):  
D V Karpenko ◽  
S A Kanaev

Abstract Intensive use of nanoparticles on an industrial scale leads to an increase in their content in the environment. This increases the risks of nano-sized objects entering the technological chains of the processing industries of the agro-industrial complex, in particular, brewing. The paper presents the results of the studies of the effect of nickel oxide nanoparticles used in various industries on the activity of the proteolytic type of enzyme preparation Neutrase 1.5MG, as well as on the results of laboratory mashing of light barley malt. The effect of different concentrations of NiO nanoparticles on the accumulation of low molecular weight nitrogenous substances during gelatin hydrolysis in model media was determined. It was found that if the content of nanoparticles exceeds 0.25 mg/cm3, the proteolytic capacity of the enzyme preparation is reduced up to 70% compared to the control at the concentration of nickel oxide nanopreparation of 2.0 mg/cm3. The experiments showed that an increase in the duration of contact between nanoparticles and proteases of the enzyme preparation in the reaction medium did not lead to an increase in the inhibitory effect of the nano-sized NiO. The laboratory mashing revealed more pronounced negative effect of nickel oxide nanoparticles on the accumulation of low-molecular nitrogen compounds. It is determined that in the presence of NiO nanopreparation, the hydrolysis efficiency of the starchy components of light barley malt is reduced. As a result, according to a number of indicators (concentration of amine nitrogen, reducing substances), the first wort obtained by mashing in the presence of nickel oxide nanoparticles at both lower (0.25 mg/cm3) and higher (2.0 mg/cm3) concentrations is inferior to samples obtained in the absence of nano-sized particles. Based on the above data, it is concluded that the presence of NiO nanoparticles in brewing environments is undesirable.


2021 ◽  
Vol 2064 (1) ◽  
pp. 012026
Author(s):  
B A Kozlov ◽  
D S Makhanko

Abstract This article presents the results of “electrical wind” investigations in CO2–laser mixtures at superatmospheric (1–12 atm) pressures. It is established that for a fixed value of the unipolar corona discharge current, the gas flow velocity does not depend on the pressure, but is determined by the chemical composition of the working mixture. The maximum values of the “electrical wind” velocity are achieved in carbon dioxide and molecular nitrogen and their values are 3.2 and 2.9 ms−1. In typical laser mixtures CO2:N2:He = 1:1:1 – 1:1:3 the velocity of the “electrical wind ” are in the range from 2.5 to 1.5 ms−.


2021 ◽  
Vol 61 (6) ◽  
pp. 864-870
Author(s):  
A. S. Kirillov ◽  
V. B. Belakhovsky ◽  
E. A. Maurchev ◽  
Yu. V. Balabin ◽  
A. V. Germanenko ◽  
...  

2021 ◽  
Author(s):  
Timothy Minton ◽  
Thomas Schwartzentruber ◽  
Chenbiao Xu

The environment encountered by space vehicles in very low Earth orbit (VLEO, 180 – 350 km altitude) contains predominantly atomic oxygen (AO) and molecular nitrogen (N2), which collide with ram surfaces at relative velocities of ~7.5 km s-1. Structural, thermal-control, and coating materials containing organic polymers are particularly susceptible to AO attack at these high velocities, resulting in erosion, roughening, and degradation of function. Copolymerization or blending of a polymer with polyhedral oligomeric silsesquioxane (POSS) yields a material that can resist AO attack through the formation of a passivating silicon-oxide layer. Still, these hybrid organic/inorganic polymers become rough through AO reactions as the passivating layer is forming. Surface roughness may enhance satellite drag because it promotes energy transfer and scattering angle randomization during gas-surface collisions. As potential low-drag and AO-resistant materials, we have investigated POSS-containing films of clear and Kapton-like polyimides that have an atomically smooth AO-resistant coating of Al2O3 that is grown by atomic layer deposition (ALD). Coated and uncoated films were exposed to hyperthermal molecular beams containing atomic and molecular oxygen to investigate their AO resistance, and molecular beam-surface scattering studies were conducted to characterize the gas-surface scattering dynamics on pristine and AO-exposed surfaces to inform drag predictions. The AO erosion yield of Al2O3 ALD-coated films is essentially zero. Simulations of drag on a representative satellite structure that are based on the observed scattering dynamics suggest that the use of the Al2O3 ALD-coated POSS-polyimides on external satellite surfaces have the potential to reduce drag to less than half that predicted for diffuse scattering surfaces. These smooth and AO-resistant polymer films thus show promise for use in the extreme oxidizing and high-drag environment in VLEO.


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