Nitrogen Ions Research Articles

Enhancing the Biodiesel Production by Improving the Yield of Lipids in Wild Strain by Inducing Nitrogen Ion Mutation in Rhodotorula mucilaginosa

The overconsumption of energy results in the depletion of fossil fuels. Generally, biodiesels are produced from wastes of animal fats and vegetable oils. In this study, we have tried to produce biodiesel from both the wild strain and ion beam mutated strain and compared the concentration of lipids produced from both the strains and their properties. Lipids were extracted from microbes using the Bligh and Dyer method and analyzed using gas chromatography and mass spectrophotometry (GCMS) and Fourier-transform infrared (FTIR) spectroscopy. Extracted lipids (free fatty acids) were converted into biodiesel (fatty acid methyl esters) using a base catalyst. The end product biodiesel was characterized and analyzed based on ASTM standards.

Influence of Surface Sputtering during High-Intensity, Hot Ion Implantation on Deep Alloying of Martensitic Stainless Steel

This article is devoted to the study of the effect of ion sputtering on the alloy surface, using the example of martensitic stainless steel AISI 420 with ultrahigh-dose, high-intensity nitrogen ion implantation on the efficiency of accumulation and transformation of the depth distribution of dopants. Some patterns of change in the depth of ion doping depending on the target temperature in the range from 400 to 650 °C, current density from 55 to 250 mA/cm2, and ion fluence up to 4.5 × 1021 ion/cm2 are studied. It has been experimentally established that a decrease in the ion sputtering coefficient of the surface due to a decrease in the energy of nitrogen ions from 1600 to 350 eV, while maintaining the ion current density, ion irradiation fluence and temperature mode of target irradiation increases the ion-doped layer depth by more than three times from 25 μm to 65 µm. The efficient diffusion coefficient at an ion doping depth of 65 μm is many times greater than the data obtained when stainless steel is nitrided with an ion flux with a current density of about 2 mA/cm2.

The Influencing Mechanisms of Reclaimed Water on N2O Production in a Multiyear Maize–Wheat Rotation

Reclaimed water (RW) is widely used in agricultural systems; however, it affects soil properties and the surrounding environment, thus influencing soil nitrogen transformation and increasing N2O and NO emissions. Understanding the influencing mechanism of N2O production in RW-irrigated soil is very important for water resource utilization and environmental protection, but it is rarely studied. This study investigated the impact of three nitrogen ions (NH4+, NO3−, NO2−) on the nitrogen transformation process and non-biological processes affecting NO and N2O emissions from soil under multiyear RW-irrigated conditions. The results showed that RW effectively increased the abundance of nitrifying and denitrifying functional genes, leading to a significant increase (p < 0.05) in soil NO and N2O emissions under ammonium treatment. Furthermore, RW can reduce the cumulative NH3 emission by 19.11% compared to deionized water (DW). In nitrate treatment, RW can significantly increase (p < 0.05) the nitrate conversion rate by increasing the abundance of denitrifying genes, but not significantly enhance N2O and NO emissions. In NO2− oxidation, RW could increase the abundance of nitrifying genes (AOA-amoA, AOB-amoA), thereby promoting the progression of nitrifier denitrification and leading to a substantial increase (p < 0.05) in soil N2O production. In summary, RW irrigation primarily increases N2O emissions from soil by enhancing soil autotrophic nitrification and heterotrophic nitration. To effectively control soil N2O emissions under agricultural irrigation with RW, it is crucial to carefully manage soil nitrification and adjust the ratio of ammonium and nitrate in the soil.

Amplification of light pulses with orbital angular momentum (OAM) in nitrogen ions lasing.

Nitrogen ions pumped by intense femtosecond laser pulses give rise to optical amplification in the ultraviolet range. Here, we demonstrated that a seed light pulse carrying orbital angular momentum (OAM) can be significantly amplified in nitrogen plasma excited by a Gaussian femtosecond laser pulse. With the topological charge of ℓ = ±1, we observed an energy amplification of the seed light pulse by two orders of magnitude, while the amplified pulse carries the same OAM as the incident seed pulse. Moreover, we show that a spatial misalignment of the plasma amplifier with the OAM seed beam leads to an amplified emission of Gaussian mode without OAM, due to the special spatial profile of the OAM seed pulse that presents a donut-shaped intensity distribution. Utilizing this misalignment, we can implement an optical switch that toggles the output signal between Gaussian mode and OAM mode. This work not only certifies the phase transfer from the seed light to the amplified signal, but also highlights the important role of spatial overlap of the donut-shaped seed beam with the gain region of the nitrogen plasma for the achievement of OAM beam amplification.

Mechanism of converting n-type to p-type conductivity in ZnO nanorods array films co-implanted with nitrogen and lithium ions

Here, we report a stable p-type conductivity in aqueous chemically grown ZnO nanorods array films co-implanted with N and Li ions. We have successfully achieved p-type conductivity, attaining a hole concentration as high as 8.97 × 1018 cm−3 and a mobility of 0.92 cm2.V−1.s−1 by co-implanting N and Li ions at a fluence of 5 × 1014 ions/cm2 for each ion. X-ray photoelectron spectroscopy analysis reveals the formation of NO, LiZn acceptors, and Lii-NO complexes. Furthermore, room temperature photoluminescence and SRIM simulation results confirm the presence of VZn. The formation of Lii-NO complex helps LiZn, VZn, and NO acceptors to actively participate in p-type conduction process. A detailed photoluminescence and Raman spectroscopy analyses together with simulation results reveal that, as the co-implantation fluence increases, excess Lii and implantation-induced structural disorders are produced, resulting in a decrease in the hole concentration. Our study showcases the potential benefits of developing a stable p-type component in ZnO-based electronic devices.

Mean Lifetimes of ns, np, nd, & nf Levels of N V

Nitrogen is one of the key elements in the evolution and formation of stellar objects. Earth's atmosphere contains 21% oxygen and 78% nitrogen; these two gases give rise to aurora when ions of the solar wind in the ionosphere collide with them. Some aerosols made of nitrogen and oxygen are also found in the atmosphere. Nitrogen, hydrogen, carbon, and oxygen are the main contributors to the origin of life on Earth. The spectrum of nitrogen ion (N V) has been studied using Quantum defect theory (QDT) and Numerical Coulombic approximation (NCA). N V has two electrons in the core, with the nucleus, and one electron outside the core. It makes it hydrogen or lithium-like. In the first part, the energies of the ns, np, nd, and nf up to n < 30 were calculated with the help of QDT. In the second part, the wavelengths were calculated using the energies and line strength parameters using NCA. Very little experimental data on lifetime and transition probability are available; however, Biemont et al. have calculated the lifetime of the 48 levels of N V using coulomb approximation. In this study, we calculated the lifetime of 196 multiplets of N V. The results are compared with the available experimental and theoretical lifetimes; an excellent agreement was found between known lifetimes and calculated in this work. The lifetimes of 100 multiplets are presented for the first time. The lifetimes of each of the Rydberg series of N V were fitted, and a third-degree polynomial represents the lifetimes of each series.

A perennial living mulch system fosters a more diverse and balanced soil bacterial community.

Cover crops are known to positively impact soil health, both at a physical level (through erosion control and organic matter enhancement) and at a biological level (by fostering more diverse microbial communities). However, most research in this area has been conducted in the context of annual cover crops that are terminated when the main crop is planted. We have previously demonstrated that a continuous "living mulch" cover crop system can enhance the physical and chemical aspects of soil health; In this study, we reveal its effect on the soil bacterial community and compare it to two different annual cover crops and a conventional control without cover crops. We examined the effect of a living-mulch (LM) system using perennial white clover (Trifolium pratense L), annual cereal rye (Secale cereale L.) (CR), annual crimson clover (Trifolium incarnatum L.) (CC), and a no-cover (NC) control at three time points during the 2018 growing season. 16S rRNA amplicon analysis of the soil bacterial community revealed that the community composition in cover crop systems was significantly different from the NC control, and that LM and CR accommodated more heterogeneous and even bacterial communities compared to the NC control. The difference in bacterial composition between cover crop systems appears to be partly influenced by soil nitrogen concentration and lime buffer capacity. Overall community diversity was associated with nitrogen and metal ion concentrations, and these associations were both stronger and more numerous later in the season. These results elucidate how a perennial cover crop system affects the soil bacterial community and advance our understanding of the interactions between crops, management practices, and soil microbiomes in sustainable agriculture.

(Invited) Cation and Anion Doping into Perovskite Lanthanum Titanium Oxides for Photocatalytic Water Splitting

Perovskite lanthanum titanium oxides have a great potential as photocatalysts for solar water splitting because of low cost, excellent operation stability and tunable surface chemistry. However, their solar energy conversion efficiency is low due to large band gap and the presence of surface trap states. This talk demonstrates our effort to dope nitrogen and metal ions into lanthanum titanium oxides to reduce the band gap and to suppress the surface trap states. Furthermore, the charge separation, migration and recombination processes have been studied.

Obtaining Efficient Mutant from the Wild Type Bacillus subtilis E6-5 by Physical and Chemical Mutagenesis for High Efficiency Protease Production, Optimizing the Mutant's Culture Medium

In this study, to enhance protease production, the wild type of Bacillus subtilis E6-5 was mutagenized by random mutagenesis using ultraviolet radiation and ethidium bromide. After combined treatment, several mutants were obtained. Among these mutants, the mutant strain with the largest proteolytic zone diameter (25 mm) was selected and named Bacillus subtilis ATA38. The enzyme production capacity of the obtained mutant was tested and the mutant strain (404 IU/mL at 24 hours) produced 6.7 times more enzyme than the parental strain (60 IU/mL at 32 hours). The effects of some important parameters in the growth medium on enzyme production were examined. The best carbon, organic nitrogen and metal ion were obtained with wheat starch (525 IU/mL), meat extract (850 IU/mL) and KCl+CaCl2 (548 IU/mL), respectively. pH 6.0, 37°C, 200 rpm, inoculum age 18 hours and inoculation amount 1% were obtained as the best physical factors.To further increase the yield, the best nutritional and physical parameters were combined to create a new modified medium. It was determined that the enzyme yield with mutant strain increased 2.7 times in the modified medium (1096 IU/mL) compared to the control (404 U/mL). The mutant strain (1096 IU/mL) showed an 18.2-fold increase in production compared to the wild type (60 IU/mL) in the modified medium. Protease enzyme obtained from ATA38 mutant strain may have great potential in industry for different purposes.

Experimental investigation and simulation of penetration depth of nitrogen ions emitted by plasma focus device inside titanium samples

The plasma focus device is a simple, inexpensive, and precious device that can be considered as a source of high-energy ions for researches relevant to interactions of ions with widely used materials such as titanium. Regarding exclusive properties such as a high degree of hardness and resistance to corrosion, titanium nitride alloy is considered to be one of the most essential materials with a wide range of industrial applications. In the present study, the characteristics of titanium nitride alloys were studied using a 1.5 kJ Mather-type plasma focus device. To do this, a Faraday cup detector is used to measure the current density of the ion beam in order to determine the energy spectrum of nitrogen ions using time of flight approach. The optimal operational condition of the device for nitrogen ions emission, in terms of gas pressure and voltage of discharge were also determined. Titanium samples were situated on the top of the anode of the device and were exposed to nitrogen ion radiation considering 5, 10, and 20 shots of the device. To simulate the penetration depth of nitrogen ions inside the titanium samples, the SRIM code is used. The obtained energy of ions from the time of flight technique was set as input of the SRIM code, and it was found that nitrogen ions, with an average energy of 50 keV can penetrate about 110 nm inside the titanium sample. It was understood that the finding results of the penetration depth are in good agreement with the SEM micrographs of the titanium samples. The sputtering yield of titanium atoms was determined using the SRIM simulation code, and it was found that the yield of the surface of the samples is less than 0.2 atoms per individual nitrogen atom.

Ionically driven synthesis and exchange bias in Mn4N/MnNx heterostructures

Ferrimagnets have received renewed attention as a promising platform for spintronic applications. Of particular interest is the Mn4N from the ε-phase of the manganese nitride as an emergent rare-earth-free spintronic material due to its perpendicular magnetic anisotropy, small saturation magnetization, high thermal stability, and large domain wall velocity. We have achieved high-quality (001)-ordered Mn4N thin film by sputtering Mn onto η-phase Mn3N2 seed layers on Si substrates. As the deposited Mn thickness varies, nitrogen ion migration across the Mn3N2/Mn layers leads to a continuous evolution of the layers to Mn3N2/Mn2N/Mn4N, Mn2N/Mn4N, and eventually Mn4N alone. The ferrimagnetic Mn4N, indeed, exhibits perpendicular magnetic anisotropy and forms via a nucleation-and-growth mechanism. The nitrogen ion migration is also manifested in a significant exchange bias, up to 0.3 T at 5 K, due to the interactions between ferrimagnetic Mn4N and antiferromagnetic Mn3N2 and Mn2N. These results demonstrate a promising all-nitride magneto-ionic platform with remarkable tunability for device applications.

A study to determine effect of metal ions for optimization of L-Asparaginase producers for bioprocessing

The present study encompasses isolation of marine bacteria from marine soil samples collected from Chirala, Coastal area of Andhra Pradesh. Work includes isolation, screening, morphological and molecular characterization of selected L- Asparaginase producers. Purified enzyme was used for enzyme kinetic studies. Marine soil sample was collected in sterile bottle and brought to the lab bench and a total of 12 morphologically distinct bacterial colonies were isolated from collected marine soil samples and coded as Chirala Marine Bacteria. All 12 Chirala Marine Bacteria isolates were qualitatively screened for L-Asparaginase production. Out of 12 Chirala marine bacteria isolates, 9 isolates show positive response to L-Asparaginase activity. Effect of inducers i.e. carbon, nitrogen, aminoacids, phosphates and metal ions was studied.

Novel Mesoporous and Multilayered Yb/N-Co-Doped CeO2 with Enhanced Oxygen Storage Capacity.

A cubic fluorite-type CeO2 with mesoporous multilayered morphology was synthesized by the solvothermal method followed by calcination in air, and its oxygen storage capacity (OSC) was quantified by the amount of O2 consumption per gram of CeO2 based on hydrogen temperature programmed reduction (H2-TPR) measurements. Doping CeO2 with ytterbium (Yb) and nitrogen (N) ions proved to be an effective route to improving its OSC in this work. The OSC of undoped CeO2 was 0.115 mmol O2/g and reached as high as 0.222 mmol O2/g upon the addition of 5 mol.% Yb(NO3)3∙5H2O, further enhanced to 0.274 mmol O2/g with the introduction of 20 mol.% triethanolamine. Both the introductions of Yb cations and N anions into the CeO2 lattice were conducive to the formation of more non-stoichiometric oxygen vacancy (VO) defects and reducible-reoxidizable Cen+ ions. To determine the structure performance relationships, the partial least squares method was employed to construct two linear functions for the doping level vs. lattice parameter and [VO] vs. OSC/SBET.

Scattering cross sections and collision integrals for N(4S)–N+(3P) and N(4S)–N+(1D) interactions

Collisions between nitrogen (N) and nitrogen ion (N+) are fundamental phenomena in the Earth and planetary atmospheres. In this work, we carried out a theoretical study of collision data for N(4S)–N+(3P) and N(4S)–N+(1D) interactions, including scattering cross sections and collision integrals. Potential energy curves of N2+ are obtained using the state-of-the-art ab initio method and then used to provide the input for calculations of resonant charge exchange and elastic cross sections. The inelastic (corresponding to the resonant charge exchange process), elastic, and total collision integrals for N(4S)–N+(3P) and N(4S)–N+(1D) interactions are computed at 500 − 50 000 K. An analysis of the collision integrals shows that the elastic collision process should not be neglected for odd-order collision interactions at low temperatures and still makes a small contribution at high temperatures. Note that this is the first time that the cross sections and collision integrals for the N(4S)–N+(1D) interaction are calculated using ab initio potential energy points. The obtained cross sections and collision integrals are essential to model the transport properties of the related plasmas.

Magnetic anisotropy in the ferromagnetic Mn and N doped ZnO Nanocrystals

(Mn, N)- codoped ZnO thin films were prepared by two step process. Study of Magnetic anisotropy in Mn and N codoped ZnO nanoparticles was studied. X-ray diffraction (XRD) &X-ray photoelectron spectroscopy (XPS) reveals that Manganese (Mn) and Nitrogen (N) ions in ZnO lattice exists as Mn2+ and N3-. Hysteresis measurement shows that at room temperature the samples show ferromagnetic nature and also indicate that the samples are having magnetic anisotropic behavior. This ferromagnetic nature in the samples is because of the hybridization between 2p of N & 3d of Mn state. The compound formed, corresponds to Mn-N-Mn cluster, which is found to be energetically strong enough for ferromagnetism at room temp.

The mixed-order chlorine decay model with an analytical solution and corresponding trihalomethane generation model in drinking water

Ensuring effective drinking water disinfection, remaining a certain amount of residual chlorine, and controlling disinfection by-product formation were very important for guarantying water quality safety and protecting public health; thus, the chlorine decay model and corresponding disinfection by-product formation model were necessary. This paper proposed a mixed-order chlorine bulk decay model (two parameters) based on Taylor's formula and derived its analytical solution. The accuracy of the mixed-order model was evaluated by comparing it with the nth-order model. To optimize the model and reduce the number of parameters required to be calibrated, the relationship of parameters with temperature, initial chlorine concentration, TOC and inorganic substance (ammonia nitrogen and iodide ion) was explored. The result proved that one of the parameters could be regarded as temperature dependent only. Meanwhile, the temperature equation of the model parameters was established by the Arrhenius formula. Subsequently, this paper selected trihalomethane as the target and study the linear relationship between chlorine consumption and trihalomethane formation. The results indicated that the liner slope had little correlation with initial chlorine concentration and temperature. On this basis, the corresponding trihalomethane model was built and its performance was proven to be good. The modeling developed in this work could be applied to drinking water distribution systems for residual chlorine and trihalomethane prediction, and provided a reference for the decision involving water quality.

Effect of the bottom electrode on the digital and analog resistive switching behavior of SiNx-based RRAM

This Letter is about the role of the bottom electrode in the resistive switching of SiNx-based resistive random-access memory. Titanium nitride (TiN) and platinum (Pt) are used as bottom electrodes to fabricate devices whose I–V characteristics are compared. The devices with Pt as the bottom electrode have digital resistive switching behavior with a main memory window. However, the devices with TiN as the bottom electrode provide an analog resistive switching with the gradual operation. We propose that this switching difference is due to the different work functions of the top and bottom electrodes and the nitrogen-rich layer formed at the SiNx/TiN interface. The work function of the bottom electrode is larger than the top electrode in the device with Pt electrodes, which are considered non-reactive. However, the difference in the work functions between the bottom and top electrodes is not much for the device with a TiN electrode. As the nitrogen-rich layer formed at the SiNx/TiN interface has nitrogen accommodation ability, the nitrogen ions are more likely to drift to the bottom electrode, and resistive switching changes from digital to analog for the device with TiN electrodes.

Gradient self-organized dislocation in expanded austenite layer during low temperature nitriding

Abstract A typical nitrogen expanded austenite layer is formed by plasma-based low-energy nitrogen ion implantation (PBLEII) on AISI 304L austenitic stainless steel at a moderate temperature of 380° C. The dislocation self-organization structure in the nitrogen expanded austenite layer is characterized as an evolution from partial and Lomer-Cottrell dislocations in the inner layer near the interface to multilayer stacking faults in the outer nitrided layer. The self-organized dislocation density and forms are essentially dependent on the plastic deformation, strain-gradient, and nitrogen-related stacking fault energies, respectively, due to the constrained expansion in the nitrided layer. As the nitrogen concentration in the austenitic matrix increases, the stacking fault energy gradually decreases, resulting in the transformation of the defect from Lamer-Cottrell dislocations to a multilayer stacking faults. The appropriate stress, which is associated with orderly stress relief during dislocation self-organization, preserves the integrity of the nitrided layer with a combinedly improved in wear and corrosion resistance. Nitriding-induced dislocation self-organization is basically explored as the formation mechanism of the nitrogen expanded austenite layer, contributing to development of the specific low-temperature nitriding austenitic steel.

Physiological and transcriptional responses of carbohydrate and nitrogen metabolism and ion balance in blueberry plants under nitrogen deficiency

Physiological and transcriptional responses of carbohydrate and nitrogen metabolism and ion balance in blueberry plants under nitrogen deficiency

Biocompatible gelatin/carbon dot nanocomposite based urea sensor and the effect of nitrogen ion implantation

In this study, we have fabricated a novel platform for sensing of urea using gelatin/carbon dots nanocomposite system. The sensor electrode was created by depositing the nanocomposite gel onto thin glass plates coated with indium tin oxide (ITO) using the drop casting technique. The behavior of these electrodes was investigated against a number of bioanalytes in the concentration range of 2–20 mM by cyclic voltammetry. The system was observed to be highly selective for urea with a sensitivity of 1.65 μA/mM/cm in the experimental linear range of 2–20 mM. Furthermore, the gelatin/CD-ITO electrode were also subjected to 50 KeV N2+ ion beam irradiation with varying fluence in the range of 1012 to 1016 ions/cm2. Sensing profile of the irradiated samples for urea suggested enhancement in sensitivity to 2 μA/mM cm2, when the ion fluence was 5 × 1015 ions/cm2. This enhancement after irradiation suggests a clear dependence of detection on the fluence of the ion beam. The observed excellent sensitivity of radiation processed nanocomposite material can be used as an enzyme-free platform for urea detection. Additionally, the CDs showed fluorescence quenching on treatment with mere 50 μM urea suggesting the high sensitivity of the platform.