Increase In Nitrogen Content Research Articles

Effects of Valine and Urea on Carbon and Nitrogen Accumulation and Lignin Content in Peach Trees.

Nitrogen availability and uptake levels can affect nutrient accumulation in plants. In this study, the effects of valine and urea supplementation on the growth of new shoots, lignin content, and carbon and the nitrogen metabolism of 'Ruiguang 39/peach' were investigated. Relative to fertilization with urea, the application of valine inhibited shoot longitudinal growth, reduced the number of secondary shoots in autumn, and increased the degree of shoot lignification. The application of valine also increased the protein level of sucrose synthase (SS) and sucrose phosphate synthase (SPS) in plant leaves, phloem, and xylem, thereby increasing the soluble sugar and starch content. It also resulted in an increase in nitrate reductase (NR), glutamine synthase (GS), and glutamate synthase (GOGAT) protein levels, with an increase in plant contents of ammonium nitrogen, nitrate nitrogen, and soluble proteins. Although urea application increased the protein level of carbon- and nitrogen-metabolizing enzymes, the increase in plant growth reduced the overall nutrient accumulation and lignin content per unit tree mass. In conclusion, the application of valine has a positive effect on increasing the accumulation of carbon and nitrogen nutrients in peach trees and increasing the lignin content.

Influence of nitrogen content on the corrosion fatigue behavior of additively manufactured AISI 316L stainless steel in chloride solution

The characterization of the corrosion fatigue behavior is detrimental for steels manufactured by laser beam powder bed fusion (PBF-LB). In this study, the corrosion and corrosion fatigue behavior of the austenitic stainless steel AISI 316L processed via PBF-LB with and without increased nitrogen content is investigated. The nitrogen alloyed steel shows improved pitting corrosion and fatigue behavior. A fracture mechanical approach was used for the fatigue data as surface defects lead to a high scatter in the results which not only allowed to separate the influence of defects but also to identify the improved defect tolerance due to nitrogen alloying.

Metrology of Ar-N2/O2 Mixture Atmospheric Pressure Pulsed DC Jet Plasma and its Application in Bio-Decontamination.

Atmospheric pressure plasma jets are gaining a lot of attention due to their widespread applications in the field of bio-decontamination, polymer modification, material processing, deposition of thin film, and nanoparticle fabrication. Herein, we are reporting the disinfection of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli bacteria using plasma jet. In this regard, Ar-O2, Ar-N2, and Ar-O2-N2 mixture plasma is generated and characterized using optical and electrical characterization. Variation in plasma parameters like electron temperature, electron density, and reactive species production is monitored with discharge parameters such as applied voltage and feed gas concentration. Results show that the peak average power consumed in Ar-O2, Ar-N2, and Ar-O2-N2 mixture plasma is found to be 4.45, 2.93, and 4.35 W respectively, at 8 kV. Moreover, it is noted that by increasing applied voltage, the electron temperature, electron density, and reactive species production also increases. It is worth noting that electron temperature increases with increase in oxygen concentration in the mixture (, while it decreases with increase in nitrogen concentration in the mixture (Ar-N2). Similarly, a decreasing trend in electron temperature is noted for Ar-O2-N2 mixture plasma. On the other hand, a decreasing trend in electron density is noted for all the mixtures. Reduction in viable colonies of Pseudomonas aeruginosa, Staphylococcus Aureus, and Escherichia coli were confirmed by the serial dilution method. The inactivation efficiency of pulsed DC plasma generated, in the Ar-N2 mixture at 8 kV and 6 KHz, was evaluated against P. aeruginosa, S. aureus and E. coli bacteria by measuring the number of surviving cells versus plasma treatment time. Results showed that after 240 s of plasma treatment, the number of survival colonies of the mentioned bacteria was reduced to less than 30 CFU/mL.

Proteomic and toxicological analysis of the response of dinoflagellate Alexandrium catenella to changes in NaNO3 concentration

Dinoflagellates of the genus Alexandrium cause Harmful Algal Blooms (HABs) in coastal waters worldwide, damaging marine environments, aquaculture, and human health. They synthesize potent neurotoxic alkaloids known as PSTs (i.e., Paralytic Shellfish Toxins), the etiological agents of PSP (i.e., Paralytic Shellfish Poisoning). In recent decades, the eutrophication of coastal waters with inorganic nitrogen (e.g., nitrate, nitrite, and ammonia) has increased the frequency and scale of HABs. PSTs concentrations within Alexandrium cells can increase by up to 76% after a nitrogen enrichment event; however, the mechanisms that underlie their biosynthesis in dinoflagellates remains unclear. This study combines mass spectrometry, bioinformatics, and toxicology and investigates the expression profiles of PSTs in Alexandrium catenella grown in 0.4, 0.9 and 1.3 mM NaNO3. Pathway analysis of protein expression revealed that tRNA amino acylation, glycolysis, TCA cycle and pigment biosynthesis were upregulated in 0.4 mM and downregulated in 1.3 mM NaNO3 compared to those grown in 0.9 mM NaNO3. Conversely, ATP synthesis, photosynthesis and arginine biosynthesis were downregulated in 0.4 mM and upregulated in 1.3 mM NaNO3. Additionally, the expression of proteins involved in PST biosynthesis (sxtA, sxtG, sxtV, sxtW and sxtZ) and overall PST production like STX, NEO, C1, C2, GTX1-6 and dcGTX2 was higher at lower nitrate concentrations. Therefore, increased nitrogen concentrations increase protein synthesis, photosynthesis, and energy metabolism and decrease enzyme expression in PST biosynthesis and production. This research provides new clues about how the changes in the nitrate concentration can modulate different metabolic pathways and the expression of PST biosynthesis in toxigenic dinoflagellates.

Hydrochemical conditions of three lakes located in the West Pomeranian region in the annual cycle

The objective of the study was to trace the variability of the hydrochemical conditions in three lakes of the West Pomeranian Voivodeship (Poland) – Starzyca, Maszewskie and Nowogardzkie in the annual cycle. The research was done in 2018–2019, and samples for analysis were collected 4 times a year. All analyses were performed applying standard methods. Such hydrochemical indices were determined as dissolved oxygen, chemical oxygen demand, content of orthophosphates, total phosphorus, nitrite, nitrate, ammonium, chlorophyll a and iron. The study showed that all lakes in the research cycle were characterised by a polymictic type of water mixing, and the trophic level, based on the adopted criteria, indicated advanced eutrophy, which may also be caused by anthropogenic pressure. Oxygen conditions characterised by deoxidation of the waters in the bottom layer in the spring and summer seasons, and clear oxygenation in the surface water layer (in Lake Maszewskie reaching even 188.5% in the spring) confirm the significant advancement of the eutrophication process. The supply of phosphorus and nitrogen in spring from pelagic waters in the waters of the examined lakes influences concentrations of chlorophyll a in the summer. The influence of “internal supply” (bottom waters and bottom sediments) on the amount of nutrients available for autotrophs is clearly visible in the analysed lakes – an increase in nitrogen and mineral phosphorus concentrations in relation to surface waters was observed in the bottom layer.

Effect of interstitial nitrogen on bonding characteristics and electronic structure of high nitrogen steel

Interstitial nitrogen can significantly change the electronic structure and bonding characteristics of austenite, and has an important influence on the properties of austenite. The bonding properties and properties of high nitrogen steel with different nitrogen element ratios were calculated. The alloy model with different nitrogen content is established, and the properties of energy, density of states and elastic constant are calculated. Increasing the nitrogen content will reduce the density of states and energy, significantly improving the stability of the cell. The crystal cells with different nitrogen content meet the mechanical stability. With the increase of nitrogen content, the elastic modulus, Poisson’s ratio gradually decreases, strength, shear strain and deformation resistance increase, and plasticity and ductility decrease.

Nitrogen transformation during fermentation in agricultural biogas plants

The aim of the present study was to determine changes in the organic nitrogen fraction in the liquid fraction of the digestate during laboratory tests of mono- and co-digestion. Three agricultural wastes were tested: distillery residue, cattle slurry and corn silage. In the mono-fermentation tests, the initial total nitrogen concentration depended on the feedstock used. As a result of the hydrolysis and ammonification of the organic matter contained in the feedstocks, there was an increase in ammonium nitrogen concentration after 28 days of fermentation. Analysis of organic nitrogen fractions showed that different organic nitrogen fractions predominated in each of the feedstocks. Four co-digestion tests were performed with 20% and 80% inoculum content and the combination of feedstocks used in the mono-fermentation. Proper evaluation of the transformation of nitrogen forms for the tests with 20 and 80% inoculum participation required the calculation of concentrations from the mass balance, taking into account the effect of changes taking place in the inoculum itself (control test). For these tests, the initial concentrations of nitrogen forms are similar to those found in the mono-fermentation tests. A greater increase in ammonium nitrogen concentrations was found for the test with 80% inoculum than in the test with 20% (for the same feedstock). An increase in the removal efficiency of the dissolved organic nitrogen fraction (DON), and an increase for the colloidal (CON) and particulate organic nitrogen (PON) fractions after 28 days of co-digestion were observed. The trend of change was similar for 20% and 80% inoculum.

Antibiotics induced changes in nitrogen metabolism and antioxidative enzymes in mung bean (Vigna radiata)

Excessive use and release of antibiotics into the soil environment in the developing world have resulted in altered soil processes affecting terrestrial organisms and posing a serious threat to crop growth and productivity. The present study investigated the influence of exogenously applied oxytetracycline (OXY) and levofloxacin (LEV) on plant physiological responses, key enzymes involved in nitrogen metabolism (e.g., nitrate reductase, glutamine synthetase), nitrogen contents and oxidative stress response of mung bean (Vigna radiata). Plants were irrigated weekly with antibiotics containing water for exposing the plants to different concentrations i.e., 1, 10, 20, 50, and 100 mg L−1. Results showed a significant decrease in nitrate reductase activity in both antibiotic treatments and their mixtures and increased antioxidant enzymatic activities in plants. At lower concentrations of antibiotics (≤20 mg L−1), 53.9 % to 78.4 % increase in nitrogen content was observed in levofloxacin and mixtures compared to the control, resulting in an increase in the overall plant biomass. Higher antibiotic (≥50 mg L−1) concentration showed 58 % decrease in plant biomass content and an overall decrease in plant nitrogen content upon exposure to the mixtures. This was further complemented by 22 % to 42 % increase in glutamine synthetase activity observed in the plants treated with levofloxacin and mixtures. The application of low doses of antibiotics throughout the experiments resulted in lower toxicity symptoms in the plants. However, significantly higher malondialdehyde (MDA) concentrations at higher doses (20 mg L−1 and above) than the control showed that plants' tolerance against oxidative stress was conceded with increasing antibiotic concentrations. The toxicity trend was: levofloxacin > mixture > oxytetracycline.

Anode Nitrogen Concentration Estimation Based on Voltage Variation Characteristics for Proton Exchange Membrane Fuel Cell Stacks

Hydrogen energy has become an important way to solve energy crises owing to its non-pollution, high level of efficiency, and wide application. Proton exchange membrane fuel cells (PEMFCs) have received wide attention as an energy conversion device for hydrogen energy. The hydrogen concentration in the PEMFC anode directly determines the output voltage of the stack. The performance of the PEMFC gradually decreases due to the accumulation of nitrogen. However, the continuous circulation of anode gas and the nitrogen accumulation at the anode due to transmembrane diffusion lead to difficulties in estimating the anode gas concentration. The relationship between anode nitrogen concentration and voltage variation characteristics was studied by increasing the anode hydrogen concentration through the method of increasing nitrogen concentration and conducting experiments on a 16-cell stack. In this paper, an estimation method for nitrogen concentration in the anode is proposed to evaluate the nitrogen concentration in the anode on the basis of voltage variation characteristics, and the method was recalibrated and validated using experimental data. Due to the inhomogeneity of the gas distribution within the PEMFC stack, the mean cell voltage can provide a more accurate estimation of the anode nitrogen concentration compared to a single cell voltage. It is shown that the proposed approach can offer a new method to estimate anode nitrogen concentration. Compared with the conventional method, the new method is simpler as it does not require additional equipment or complex algorithms. In this paper, the anode nitrogen concentration was estimated by applying this method with a maximum error of only 0.35%.

Characterization of thermophysical and mechanical properties of hafnium carbonitride fabricated by hot pressing sintering

Dense HfCxN1−x carbonitride ceramics are very promising as potential ultra-high temperature ceramics (UHTCs) for application under extremely harsh environments. However, the thermophysical and mechanical properties of the HfCxN1−x carbonitrides have not been investigated clearly. The present work prepared HfCxN1−x (x = 0.3, 0.4, 0.5, 0.6, 0.7) ceramics at 1950 °C under 30 MPa in flowing Ar atmosphere by using hot pressing sintering method. The relative densities of the samples obtained reached above 96%. Thermal conductivity of the as-prepared HfCxN1−x carbonitrides ranged from 19 to 24 W m−1 K−1 at room temperature. The increased role of electrons in thermal conduction caused by both increasing nitrogen content and increasing temperature, resulted in improved thermal conductivity, varying from 32 to 39 W m−1 K−1. With increasing nitrogen content, the electrical conductivity also increased, ranging from 149 to 213 × 104 Ω−1 m−1. With the increase of nitrogen content, Hf-C covalent bonds are gradually replaced by Hf-N covalent bonds with lower bond strength, resulting in HfC0.7N0.3 exhibiting the highest room-temperature flexural strength and hardness, HfC0.3N0.7 exhibiting the highest fracture toughness. Their mechanical properties are greatly improved over the binary HfC and HfN. The high-temperature flexural strength of the HfC0.7N0.3 decreased from 324 MPa at 1000 °C, to 139 MPa at 1600 °C and 100 MPa at 2000 °C. Meanwhile, it was revealed that the high-temperature flexural strength decreased with increasing nitrogen content for the as-prepared HfCxN1−x carbonitrides, similar to the changing trend of room-temperature flexural strength. The HfC0.3N0.7 possessed high-temperature plasticity at 2000 °C, attributed to the ability of the coarser grain to produce numerous layer dislocations.

Preparation and performance study of dye-based carbon quantum dots

The preparation of Full-color carbon dots is well established, but the explanation of its mechanism is not only highly controversial, but partly even contradictory to the project. Therefore, to investigate the red-shift mechanism of Full-color carbon dots, citric acid and Nile blue with complex composition structure were selected as raw materials, and B-,G-,Y- and R-CQDs were prepared by changing the reaction solvent with quantum yields of 49.7 %,28.2 %,72.3 %,30.3 % and average particle sizes of mainly 2.7–3.2 nm, respectively. TEM and XPS tests show that the emission wavelength redshift is mainly attributed to the reduction of the energy band gap due to the sp2 conjugate size and the increase of graphitic nitrogen content. To examine the optical properties of dye-based F-CQDs, F-CQDs/PVA polymer films and LEDs were prepared, both of which showed unique optical properties.

Investigation into Red Emission and Its Applications: Solvatochromic N-Doped Red Emissive Carbon Dots with Solvent Polarity Sensing and Solid-State Fluorescent Nanocomposite Thin Films.

In this work, a NIR emitting dye, p-toluenesulfonate (IR-813) was explored as a model precursor to develop red emissive carbon dots (813-CD) with solvatochromic behavior with a red-shift observed with increasing solvent polarity. The 813-CDs produced had emission peaks at 610 and 698 nm, respectively, in water with blue shifts of emission as solvent polarity decreased. Subsequently, 813-CD was synthesized with increasing nitrogen content with polyethyleneimine (PEI) to elucidate the change in band gap energy. With increased nitrogen content, the CDs produced emissions as far as 776 nm. Additionally, a CD nanocomposite polyvinylpyrrolidone (PVP) film was synthesized to assess the phenomenon of solid-state fluorescence. Furthermore, the CDs were found to have electrochemical properties to be used as an additive doping agent for PVP film coatings.

Salinity and high pH reduce denitrification rates by inhibiting denitrifying gene abundance in a saline-alkali soil

Denitrification, as the main nitrogen (N) removal process in farmland drainage ditches in coastal areas, is significantly affected by saline-alkali conditions. To elucidate the effects of saline-alkali conditions on denitrification, incubation experiments with five salt and salt-alkali gradients and three nitrogen addition levels were conducted in a saline-alkali soil followed by determination of denitrification rates and the associated functional genes (i.e., nirK/nirS and nosZ Clade I) via N2/Ar technique in combination with qPCR. The results showed that denitrification rates were significantly decreased by 23.83–50.08%, 20.64–57.31% and 6.12–54.61% with salt gradient increasing from 1 to 3‰, 8‰, and 15‰ under 0.05‰, 0.10‰ and 0.15‰ urea addition conditions, respectively. Similarly, denitrification rates were significantly decreased by 44.57–63.24% with an increase of the salt-alkali gradient from 0.5 to 8‰. The abundance of nosZ decreased sharply in the saline condition, while a high salt level significantly decreased the abundance of nirK and nirS. In addition, the increase of nitrogen concentration attenuated the reduction of nirK, nirS and nosZ gene abundance. Partial least squares regression (PLSR) models demonstrated that salinity, dissolved oxygen (DO) in the overlying water, N concentration, and denitrifying gene abundance were key determinants of the denitrification rate in the saline environment, while pH was an additional determinant in the saline-alkali environment. Taken together, our results suggest that salinity and high pH levels decreased the denitrification rates by significantly inhibiting the abundance of the denitrifying genes nirK, nirS, and nosZ, whereas increasing nitrogen concentration could alleviate this effect. Our study provides helpful information on better understanding of reactive N removal and fertilizer application in the coastal areas.

Characteristics of Filtrates From Soil Treated by Ozone

Ozone soil treatment is very effective not only in exterminating soil-born worms but also in enhancing plant growth. According to the authors’ previous works, vegetables cultivated in ozone-treated soil showed enhanced plant growth. In order to understand the mechanism behind the effectiveness of ozone-treated soil in boosting plant growth, in this study filtrates were extracted from ozone-treated soil and were examined by ultraviolet-visible spectrophotometry. Two types of soil—commercial soil and natural andosol—were treated by ozone in both infrared-transparent and infrared-absorbing chambers. The increased nitrogen content was notably higher in the andosol in comparison to the commercial soil. In addition, the filtrates extracted from the ozone-treated soils showed brown coloration, corresponding to absorbance at approx. 300 to 600 nm and indicating the generation of fulvic acid, which is a biostimulant. Therefore, it can be considered that biostimulants such as fulvic acid are generated after ozone treatment of soil and activate microorganisms around the plant’s roots, which leads to enhanced plant growth. Moreover, the filtering of ozone-treated soil can be a unique method to produce a biostimulant in a very short time.

Global patterns and key drivers of stream nitrogen concentration: A machine learning approach

Anthropogenic loading of nitrogen to river systems can pose serious health hazards and create critical environmental threats. Quantification of the magnitude and impact of freshwater nitrogen requires identifying key controls of nitrogen dynamics and analyzing both the past and present patterns of nitrogen flows. To tackle this challenge, we adopted a machine learning (ML) approach and built an ML-driven representation that captures spatiotemporal variability in nitrogen concentrations at global scale. Our model uses random forests to regress a large sample of monthly measured stream nitrogen concentrations onto a set of 17 predictors with a spatial resolution of 0.5-degree over the 1990–2013, including observations within the pixel and upstream drivers. The model was validated with data from rivers outside the training dataset and was used to predict nitrogen concentrations in 520 major river basins of the world, including many with scarce or no observations. We predicted that the regions with highest median nitrogen concentrations in their rivers (in 2013) were: United States (Mississippi), Pakistan, Bangladesh, India (Indus, Ganges), China (Yellow, Yangtze, Yongding, Huai), and most of Europe (Rhine, Danube, Vistula, Thames, Trent, Severn). Other major hotspots were the river basins of the Sebou (Morroco), Nakdong (South Korea), Kitakami (Japan), and Egypt's Nile Delta. Our analysis showed that the rate of increase in nitrogen concentration between 1990s and 2000s was greatest in rivers located in eastern China, eastern and central parts of Canada, Baltic states, Pakistan, mainland southeast Asia, and south-eastern Australia. Using a new grouped variable importance measure, we also found that temporality (month of the year and cumulative month count) is the most influential predictor, followed by factors representing hydroclimatic conditions, diffuse nutrient emissions from agriculture, and topographic features. Our model can be further applied to assess strategies designed to reduce nitrogen pollution in freshwater bodies at large spatial scales.

Seasonality and assembly of soil microbial communities in coastal salt marshes invaded by a perennial grass

Plant invasion profoundly changes the microbial-driven processes in the ecosystem; however, the seasonality of soil microbial communities and their assembly under plant invasion is poorly understood. In this study, coastal salt marshes with native Suaeda salsa (L.) Pall. and exotic Spartina alterniflora Loisel. in the Yellow River Estuary, North China, were selected, and soil bacterial and fungal communities and their seasonal variance were characterized by metabarcoding sequencing of the 16S rRNA gene and ITS2 regions, respectively. The importance of deterministic and stochastic processes in shaping bacterial and fungal seasonal assembly was explored by the null model. Results showed that soil microbes exhibited the lowest diversities in spring, while their diversity significantly improved in summer and autumn with the increase in organic carbon and nitrogen content in soils. Strong seasonal variances in microbial communities were observed, but plant invasion reduced the seasonal variation strength of soil bacteria. For the microbial assembly, the seasonal variability of soil bacterial community was mainly controlled by homogeneous selection, whereas soil fungal community was dominantly structured by stochastic processes. Among the selected variables, soil pH was the key abiotic factor driving the seasonal changes in bacteria and fungi. The microbial function annotation derived from taxonomy-based inference suggested that carbon metabolism was relatively stronger in spring, but nitrogen and sulfur metabolism increased evidently in summer and autumn, and the proportion of saprophytic fungi increased substantially after plant invasion. The seasonal turnover of bacterial and fungal groups were tightly associated with the seasonal variation in soil carbon and nitrogen contents. Collectively, these findings reveal the strong seasonal variability of different soil microbial constituents in plant-invaded coastal salt marshes and suggest the linkage between microbial community assembly and microbial-mediated functions in the context of plant invasions.

Supersonic Shrouding Methane Mixtures for Supersonic Combustion Coherent Jets

A coherent jet oxygen supply plays a key role in the process of electric arc furnace steelmaking: it provides the necessary oxygen for the smelting of molten steel and promotes the flow of the molten pool. Compared with coherent jets in current use, the supersonic combustion coherent jet shrouded in supersonic methane gas could improve the impact capacity and stirring intensity of the molten pool. In order to reduce the smelting cost, the characteristics of the supersonic combustion coherent jet shrouding the supersonic methane and nitrogen mixtures must be studied. Computational fluid dynamics software is used to simulate the supersonic combustion coherent jet under various methane–nitrogen mixing conditions. The six-component combustion mechanism of methane and the Eddy Dissipation Concept combustion reaction model are selected. In agreement with thermal experiments, the simulation results show that the inclusion of a small amount of nitrogen has little effect on the combustion of supersonic shrouding methane gas. However, as the nitrogen content increases, the combustion region of supersonic shrouding gas becomes shorter in length, resulting in decreases in the lengths of the high-temperature, low-density region, and the high-turbulence-intensity region. These effects weaken the ability of the shrouding gas to envelop the main oxygen jet. The potential core length of the main oxygen jet decreases significantly; this decrease first accelerates and then decelerates. These results demonstrate the feasibility of including a small amount of nitrogen (about 10 wt%) in the supersonic shrouding methane gas without substantial negative impacts on the characteristics of the supersonic combustion coherent jet.

Reactive HiTUS TiNbVTaZrHf-Nx Coatings: Structure, Composition and Mechanical Properties.

High entropy metal sub-lattice stabilized nitride coatings based on multicomponent refractory transition metals (TM = Ti, Nb, V, Ta, Zr, Hf) are promising candidates for extreme conditions due to their high thermal, mechanical, and corrosion properties. The aims of the current work included the investigations of the possibilities of the novel High Target Utilization Sputtering (HiTUS) technique applied to reactive sputtering of TiNbVTaZrHf-xN coatings from the viewpoints of hysteresis behavior during reactive sputtering as well as the structure, composition, stoichiometry, and mechanical properties of the resulting coatings. With increasing nitrogen content, coating structures varied from amorphous in metallic alloy coatings to textured nano-columnar fcc structures. Despite certain deviations of TM from equiatomic concentrations, homogeneous solid solutions corresponding to single-phase multicomponent nitride analogous to high entropy stabilized compounds were obtained. Mechanical properties were found to be proportional to nitrogen content. The highest hardness HIT ~ 33 GPa and indentation modulus EIT ~ 400 GPa were found in a slightly sub-stoichiometric (~42 at% nitrogen) composition. HIT/EIT and limited pillar split measurements suggested that these coatings exhibit low fracture toughness (around 1 MPa.m1/2). The work confirmed that reactive HiTUS is suitable for the preparation of multicomponent nitrides with the control of their stoichiometry and mechanical properties only via nitrogen additions.

Effect of N doping on the microstructure and dry etch properties of amorphous carbon deposited with a DC sputtering system.

The importance of developing a hardmask with excellent performance, and physical and chemical properties to utilize in long-term etching is spotlighted due to the acceleration of development in high-density semiconductors. To develop such a hardmask, amorphous carbon hardmasks doped with various concentrations of N were fabricated with a DC magnetron sputtering system using varying inert gas (Ar to N2) ratios. In contrast to the expectation that doped nitrogen would block the permeation of fluorine and improve the etch resistance, as the nitrogen concentration increased, the selectivity of the doped amorphous carbon films decreased. To understand this degradation with increasing nitrogen concentration, systematic X-ray photoelectron spectroscopy (XPS), radial distribution function (RDF), and X-ray reflectometry (XRR) analyses were conducted. In this study, we found that as the amount of nitrogen increased, the density of the film decreased, and the amount of pyridinic and pyrrolic nitrogen bonds with low formation energy increased. In contrast, based on time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis of etched nitrogen-doped amorphous carbon films, the penetration depth of fluorine ions from the etchant decreased as the amount of nitrogen increased. Therefore, in order to develop an excellent hardmask using amorphous carbon, it is important to increase the density of the film and the nitrogen concentration in the film while lowering the ratio of pyrrolic N to pyridinic N, i.e., increasing the ratio of graphitic N.

Chemical properties of aerobic compost from abattoir and poultry slaughter waste

The present study was undertaken to analyse the chemical properties of aerobic compost from abattoir and poultry slaughter waste. Various abattoir waste materials like rumen contents, abattoir sewage sludge, poultry feathers and commercially available coir pith were preprocessed and separately analysed for their physico-chemical properties. Based on the analysis of physico-chemical properties of raw materials, five different combinations were selected for aerobic composting viz. sludge and coir pith (1:1); rumen contents alone (100); rumen contents and poultry feathers (1:1); rumen contents and sludge (1:1); rumen contents, sludge and coir pith (1:1:0.5).The selected combinations were subjected for aerobic composting for a period of 60 days in biobins. Chemical properties like organic carbon, total nitrogen, carbon to nitrogen ratio (C: N ratio), total phosphorus and total potassium before and after composting were analysed. There was a significant (p<0.05) increase in total nitrogen, total phosphorus and total potassium content and significant (p<0.05) decrease in C: N ratio and organic carbon content after composting.