Abstract A study of the grain surface structure and seedling development of wheat, barley, oats, and rye depending on short‐term treatment of their grains in Ar–O 2 and Ar–air cold plasma and ...post‐discharge with a perspective of implementation of the method on an industrial scale is presented. Following parameters are monitored: chemical composition of plasma, grain surface roughness, germination rate, seed germination, length of seedlings, dry mass of stems and roots, as well as vigor index II. The results show that even an 8.7‐s‐long treatment of grains in postdischarge can improve the root system of seedlings, increasing its mass up to 16.2% (barley), 15.6% (rye), and 14.3% (wheat) within the first 10 days after sowing.
The vibration dampers, shock absorbers, seismic isolation, bearing seals, compensation devices are widely applied in civil engineering, machine manufacturing and shipbuilding, aviation and aerospace ...engineering. For these details fabrication elastomeric materials are used. Rubber and rubber-like materials (elastomers) have the capability of absorbing input energy much better than other engineering materials. Elastomeric materials give many engineering advantages due to their high elasticity, good dynamic properties, low volume compressibility, a linear relationship between stress and strain at small and middle deformation, resistance to aggressive environmental factors. The disadvantage of elastomeric materials is ageing, i.e. changing their mechanical properties over time and lowering their operational capability. In given paper the influence of ageing of elastomeric materials on the damping properties of shock absorbers is considered based on the mechanical models of elastomers - Maxwell and Burgers modes.
Abstract
Dielectric‐barrier discharges (DBDs) in Ar–N
2
mixtures, with N
2
fractions in 0.1–1% range, would be attractive alternatives to DBDs in pure N
2
if energy‐transfer reactions between Ar(1s) ...atoms and N
2
molecules were an efficient source of N atoms. Attempts to functionalize polyolefins in flowing postdischarges fed by such DBDs, as well as the search for the First Positive System in the emission spectrum, however, failed. Evidently, the energy‐transfer reactions do not produce N atoms. For Ar(1s
3
) and Ar(1s
5
) metastable states, this fact has already been reported in the literature. For Ar(1s
2
) and Ar(1s
4
) resonant states, a quantitative argument is derived in this paper: energy transfer from Ar(1s) atoms to N
2
molecules is not an efficient source of N atoms.
Dielectric‐barrier discharges (DBDs) in Ar–N2 mixtures, with N2 fractions in 0.1–1% range, would be attractive alternatives to DBDs in pure N2 if energy‐transfer reactions between Ar(1s) atoms and N2 ...molecules were an efficient source of N atoms. Attempts to functionalize polyolefins in flowing postdischarges fed by such DBDs, as well as the search for the First Positive System in the emission spectrum, however, failed. Evidently, the energy‐transfer reactions do not produce N atoms. For Ar(1s3) and Ar(1s5) metastable states, this fact has already been reported in the literature. For Ar(1s2) and Ar(1s4) resonant states, a quantitative argument is derived in this paper: energy transfer from Ar(1s) atoms to N2 molecules is not an efficient source of N atoms.
Dielectric‐barrier discharges (DBDs) in Ar–N2 mixtures, with molar N2 fractions below 1%, would be attractive alternatives to DBDs in pure N2 if energy‐transfer reactions between Ar(1s) atoms and N2 molecules were an efficient source of N atoms. The failure of attempts to functionalize polyolefins in flowing postdischarges fed by such DBDs, however, showed that this energy transfer does not produce significant amounts of N atoms. For Ar(1s3) and Ar(1s5) metastable states, this had already been reported in literature. As shown here, the sum of rate coefficients for N2 dissociation by Ar(1s2) and Ar(1s4) resonant states is less than 2 × 10–13 cm3/s, nearly two orders of magnitude below the total quenching rates.
Elastomeric materials, both natural rubber and synthetic, are widely used in industry and civil engineering, due to their unique properties: high elasticity, low volume compressibility, capability to ...absorb and dissipate input energy, a linear relationship between stress and strain up to strain of 15% ÷ 20%, resistance to aggressive environmental factors. Different kind of compensation devices, vibration dampers, shock absorbers are fabricated from rubber materials.At the same time the elastomeric materials nonreversible change their properties over time, this disadvantage is called ageing.In given paper the results of experimental studying of the influence of aging on the physical-and-mechanical properties of polyurethane rubber is presented. The samples of cylindrical form were prepared from soft flexible polyurethane rubber Xenias PX30 and subjected to the artificial ageing. Accelerated aging of samples was fulfilled in accordance with European standard ISO 188:2011 (Rubber, vulcanized or thermoplastic - Accelerated ageing and heat resistance tests).The changing of volume, Shore A hardness, elastic rebound coefficient and static elasticity modulus under compression were investigated. Experiments showed the volume decrease, hardness shore increasing, elastic rebound increase and compression modulus under static loading increasing. This data are necessary for correct designing of the compensation devices to provide their working properties during all service life.
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