Role Of Nitrogen Content Research Articles

Role of Nitrogen Content on Interrelationship Between Creep Deformation and Damage Behaviour of 316LN SS

Role of Nitrogen Content on Interrelationship Between Creep Deformation and Damage Behaviour of 316LN SS

Nanocast nitrogen-containing ordered mesoporous carbons from glucosamine for selective CO2 capture

D-glucosamine is investigated as a non-toxic and sustainable carbon/nitrogen (C/N) source for the templated synthesis of nitrogen-containing CMK-8 ordered mesoporous carbons (NOMCs) conceived for selective CO2 uptake. Pyrolysis temperature is varied during nanocasting using the KIT-6 silica hard template to tailor microporosity and nitrogen inclusions. NOMCs exhibit large surface area (600–1000 m2 g-1) and excellent pore ordering. The CO2/adsorbent interaction energy is estimated by the isosteric enthalpy of adsorption (∼33–40 kJ mol-1) and Henry's constants. The role of nitrogen content (∼7–12 at.%) and of each type of N-species on CO2 adsorption is studied by X-ray photoelectron spectroscopy, and CO2/N2 selectivity is attributed, being pyridinic functionalities the most effective ones. NOMCs are tested at different temperatures, gas flow compositions, reversibility, and so on; in all tested conditions, they outperform a homologous bare sucrose-derived carbon. Enhancing micropore volume allows achieving maximum adsorption capacity in pure CO2 (1.47 mmol g−1 at 30 °C/0.9 bar), whereas increasing surface N-content accounts for the highest selectivity in CO2/N2 mixtures (20/80 v/v) at 35 °C/1 bar (maximum CO2 uptake 0.82 mmol g−1). The combination of a suitable C/N precursor and the hard templating synthetic route is effective for obtaining high-performing, sustainable, and reusable selective CO2 sorbents, without any activation steps or N-doping post-treatments.

Inert Gas Atomization of High‐Nitrogen TRIP‐Steels

High nitrogen steels with transformation induced plasticity (TRIP) effect have been recently developed within the framework of the project CRC799. These steels are utilized in a form of powder for the needs of this project. Therefore, the current study focuses on the powder production of high nitrogen steels via inert gas atomization process. Specifically, the role of nitrogen content in determination of the basic powder properties and its behavior on the atomization process are investigated. Additionally, the effects of several other process parameters, such as temperature of the melt and gas to metal ratio are discussed. Thereby, the effect of nitrogen content on the median particle size is not confirmed. Meanwhile, an increase in the spraying temperature and a rise in gas to metal ratio lead to a slight decrease in the median particle size. Nitrogen content in the powder is technologically controlled by the atmosphere above the melt before the spraying process. At last, nitrogen shows a significant impact on the phase composition of powder, by stabilizing the austenite phase. The results thus obtained are of high interest for the future application of the designed steels in the powder form.

Contribution of total nitrogen content in storage roots to multiple regression analysis for estimating yield of asparagus in rootstock-planting forcing culture

Rootstock-planting forcing culture is used in Japan to harvest asparagus spears out of season. To assess the yield before the actual harvest, we performed a multiple regression analysis using yield as a dependent variable and rootstock weights, chilling hours (i.e., cumulative hours during which the air temperature remained lower than 5°C), Brix values of storage roots, and total nitrogen content of storage roots as independent variables. Our previous study showed that rootstock weights and chilling hours were significant as independent variables. The addition of the nitrogen content of storage roots as an independent variable in the present analysis caused the multiple correlation coefficient to increase significantly (p=0.05). The possible role of nitrogen content in yield estimation is discussed.

Interface study between nanostructured tantalum nitride films and carbon nanotubes grown by chemical vapour deposition

Abstract We present the role of nitrogen content in tantalum nitride ultra-thin buffers, on the carbon nanotubes (CNTs) growth by chemical vapour deposition at 850 °C, assisted by ferrocene as catalyst source. Tantalum nitride (TaN x ) films with a very large range of concentration x = [0, 1.8] and various nanostructures, from amorphous Ta(N) to Ta 3 N 5 , were deposited by Highly Pulsed Plasma Magnetron Sputtering. The buffer films are characterized after heat treatment at 850 °C, and after the CNT growth, by wide angle X-ray scattering in grazing incidence and scanning electron microscopy. The CNT diameter explored by transition electron microscopy shows an all-out value for under stoichiometric thin films (Ta 1 -N 1−δ , Ta 3 -N 5−δ ) and a minimum value just above the stoichiometric phases (Ta 1 -N 1+δ , Ta 3 -N 5+δ ). Firstly one shows that the buffer films under the heat treatment present surface modification highly dependent on their initial state, which influences the catalyst particles diffusion. Secondly at the stoichiometric TaN phase we show that a specific ternary phase FeTa 2 O 6 is formed at the interface CNT/buffer, not present in the other cases, leading to a special CNT growth condition.

The Behaviour of Nitrogen on the Welding Parameters of the Dissimilar Weld Joints between AISI 304 and AISI 316L Austenitic Stainless Steels Produced by Gas Tungsten Arc Welding

The behavior of nitrogen into the dissimilar joining metal between AISI 304 and AISI 316L Austenitic stainless steel during gas tungsten are welding process was investigated. Studied by using an arc nitrogen atmosphere – controlling in chamber. The relations between nitrogen content of the dissimilar weld metal and the welding parameters, such as the welding current, welding speed, welding arc length and penetration area of weld metals were also evaluated. The results show that the nitrogen content of the weld metals decreased with an increasing welding current, and increasing penetration areas of weld metal, but scarcely depends on the welding arc length. The nitrogen content of the weld metals increased with the welding speed, but decreased penetration areas of weld metals. The role of nitrogen content on the dissimilar weld metals stainless steel is further confirmed by the experimental microstructure, mechanical and corrosion behaviour of the weld metal.

Micro-segregation and Precipitation of Alloy 690 during Isothermal Solidification: the Role of Nitrogen Content

The segregation and precipitation behavior of Alloy 690 containing 0.001-0.11 wt% nitrogen during isothermal solidification at 1370 and 1355 degrees C have been investigated using optical microscopy (OM), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The results indicate that the volume fraction of TiN-type nitride formed during isothermal solidification increases with the nitrogen content of Alloy 690. Segregation of Ti and Cr exists in samples solidified at 1370 and 1355 degrees C. The Ti content in the residual liquid markedly decreases and the concentration of Cr increases when the nitrogen content of Alloy 690 increases. Furthermore, N and S also show segregation to some extent in the residual liquids at 1355 degrees C. Accompanying by the segregation of Cr, Ti, C, N and S, sulfides and chromium nitrides form. In a low nitrogen content Alloy 690, sulfur segregates and precipitates in the form of Ti4C2S2 and (Cr, Ti)S, but in the form of (Cr, Ti)S or CrS in a high nitrogen content Alloy 690. (Cr, Ti)N-type nitrides with an fcc crystal structure have been identified in a sample with 0.11 wt% nitrogen.

Dielectric investigations on ‘MgAlON’ compounds: role of nitrogen content

Abstract The dielectric properties of dense polycrystalline magnesium aluminium oxynitride have been investigated up to 90 °C. The oxygen/nitrogen substitution on the anionic lattice of this solid solution enhances the charge trapping ability and the dielectric breakdown of ‘MgAlON’ compounds. Oxygen vacancies, which play the role of electron traps, can partially explain the good dielectric properties of this solid solution at low temperature; but they are ineffective for higher temperature where the charge trapping phenomenon remains active. This behaviour, specific to ‘MgAlON’ solid solution, is explained on the basis of a crystallographic model of atom repartition: this spinel structure offers rich-nitrogen zones randomly located as AlN 4 clusters which generate locally the heterogeneous zones of electric charge supposed to be responsible for the good dielectric performance of ‘MgAlON’ compounds. The local polarizability is modified which enhances the charge-trapping phenomenon.

The role of nitrogen content on the rolling contact fatigue performance of En31 ball bearing steels

Using an accelerated service-simulation test, the role of nitrogen content on the rolling contact fatigue resistance of a range of En31 ball bearing steels was assessed. Nitrogen content appears to be a significant factor in steel performance. Air-melted neutral open hearth and acid open hearth materials, which were superior to air-melted basic electric arc steels, were comparatively low in nitrogen. With the basic electric arc materials there was a trend towards reduced rolling contact fatigue life with increased nitrogen content.