Nitrogen Content Of Samples Research Articles

Experimental analysis and WallDYN simulations of the global nitrogen migration in ASDEX Upgrade L-mode discharges

This work presents ASDEX Upgrade experiments, where the nitrogen deposition and re-erosion on divertor manipulator samples and the effect of its transport through the plasma were studied. These results are compared to WallDYN-DIVIMP simulations based on SOLPS plasma backgrounds and employing an improved WallDYN model, which includes the effusion of nitrogen from saturated surfaces. On one hand, this allows the WallDYN code and the new saturation model with a comprehensive data set to be benchmarked, on the other hand the simulations help in the interpretation of the experimental results. Both, experimental results and simulations, show that the N content in the region of the outer strike line reaches its steady-state value within one discharge. The simulations also reproduce the experimentally observed nitrogen content in samples exposed to N2-seeded discharges. With respect to the boron deposition, the nitrogen deposition in a non-seeded discharge and the re-erosion of nitrogen discrepancies to the WallDYN-DIVIMP simulations are observed. Based on SDTrimSP simulations, these are attributed to the missing depth resolution of the WallDYN surface model. A detailed comparison of spectroscopic measurements to WallDYN simulations, based on a novel synthetic spectroscopy diagnostic for WallDYN, shows that the nitrogen fluxes in the plasma are well described by the simulations. From a comparison of several WallDYN-DIVIMP simulations employing customized onion-skin model plasma backgrounds the physical processes controlling the nitrogen concentration in the core plasma and the applicability of onion-skin model plasma backgrounds are discussed. From these simulations the private flux zone with the gas valve, the outer baffle and the high field side main wall are identified as the main sources for the nitrogen content of the core plasma.

Quantitative analysis of cellulose nitrates by Fourier transform infrared spectroscopy

Quantitative express analysis of nitrogen content in cellulose nitrates by Fourier transform infrared spectroscopy has been developed. The slope of the dependence of the ratio of the band intensity (and area) to sample weight in a tablet, on the nitrogen content in a sample was used to find the reduced extinction coefficients for quantitative analysis of nitrogen content in cellulose nitrate samples by IR spectroscopy. The results were compared with the nitrogen content values in the same samples determined by the ferrosulfate method.

Effect of the Licorice (Glycyrrhiza glabra) Ethanol Extract on Growth of Bacillus cereus at the Meju Producing Stage

The effects of Licorice ethanol extracts, which are natural antibiotic active materials, against the growth of Bacillus cereus and of Licorice extracts on soybean paste were investigated. Licorice extracts had strong effects against the growth of B. Cereus when added at a concentration of 0.05% to the nutrient broth. Licorice extracts were added at the Meju producing stage to investigate its effects against B. cereus and ripening soybean paste. In these experiments, 96% of B. cereus was eliminated in the soybean paste containing Licorice extract concentration of 0.05% compared with soybean paste without Licorice extract. In addition, no B. cereus was detected in soybean paste when Licorice extract at a concentration of 0.4% was added. The amino nitrogen content in samples containing the added Licorice extracts was not much different from the control; thus, the Licorice extract does not appear to affect ripening soybean paste. Consequently, the addition of Licorice extracts to soybean paste holds promise for use as an effective method to eliminate B. cereus from soybean paste.

Structural properties of reactively sputtered W–Si–N thin films

Tungsten-silicon-nitrogen, W–Si–N, ternary thin films have been reactively sputter deposited from W5Si3 and WSi2 targets using several nitrogen partial pressures. The films have been thermal annealed in the 600–1000°C temperature range and a wide region of the W–Si–N ternary phase diagram has been explored by changing the N2∕Ar ratio during the deposition. Multitechnique approach was adopted for the analysis of the samples. Composition has been determined via ion beam analysis; chemical states were investigated using x-ray photoelectron spectroscopy (XPS); crystalline structure was studied using transmission electron microscopy (TEM) and x-ray diffraction (XRD) and surface morphology by scanning electron microscope. The films deposited in pure argon atmosphere are tungsten rich and approach the target contents as N2∕Ar ratio is varied during deposition. Tungsten enrichment in the films is caused by resputtering of silicon which can be inhibited by the formation of silicon nitride, allowing films with Si∕W ratio closer to the target compositions. The higher capability to form nitrides with silicon than with tungsten favors enhancement of nitrogen content in samples deposited from the silicon rich target (WSi2). The samples with excess nitrogen content have shown losses of this element after thermal treatment. XPS measurements show a break of W–N bonds caused by thermal instability of tungsten nitrides. TEM and XRD revealed the segregation of tungsten in form of metallic or silicide nanoclusters in samples with low nitrogen content (W58Si21N21 and W24Si42N34). High amounts of nitrogen were revealed to be highly effective in inhibiting metallic cluster coalescence. Measurements of electrical resistivity of as deposited films were performed using four point probe technique. They were found to lie in the range between 0.4 and 79mΩcm depending on sample composition.

Chemiluminescent Method for Detection of Eutrophication Sources by Estimation of Organic Amino Nitrogen and Ammonium in Water

An automatic method has been developed for the estimation of organic amino nitrogen (CH2-NH) and ammonium in water samples. We propose a continuous flow system in which nitrogen compounds react with hypochlorite reagent to produce chloramines. Subsequently, the mixture is mixed with luminol, generating a chemiluminescence signal. The signal emission at 425 nm, registered as a function of time, decreases as nitrogen concentration increases, due to the decrease on hypochlorite concentration. A large number of nitrogen compounds have been assayed and their sensitivities compared, in milligrams per liter nitrogen. The ammonium calibration graph, expressed as N, can be used for most of the assayed compounds. The linear interval was 0.24-4 mg L(-1) N, with the detection limit 0.07 mg L(-1) N. The chemiluminescence method was applied to the analysis of several kinds of real water samples, natural, lake, irrigation ditch, fountain, residual, and seawater in order to detect possible sources of eutrophication. The accuracy (% relative error) and precision were satisfactory, with mean values of 5 +/- 4 and 3 +/- 2, respectively. This procedure has been used to estimate nitrogen content in samples before and after Kjeldahl treatment. In the same samples, the N found for the untreated samples provided a good estimation of the N Kjeldahl. Sixty samples per hour can be analyzed, and the procedure can also be used for in situ monitoring.

Curie temperatures of Sm 2Fe 17N x (0 < x < 3) of intermediate nitrogen concentrations

For the investigation of the relationship between the Curie temperatures ( T c) and nitrogen contents ( x) in the intermediate nitrogen content samples of Sm 2Fe 17N x (0 < x < 3), the newly developed two-step reaction of that in pure N 2 gas followed by the annealing in Ar with dilute N 2 ( P N 2 < 1 Pa) gas atmosphere was employed. The T c in the samples were measured with VSM, and the nitrogen contents in the sample particles were directly detected using EPMA and MFM. After the adequate treatments of the data, the volume fraction of a region having a certain T c value and that having a certain nitrogen content ( x) can be calculated. As conclusion, the relation between the T c and the x value was determined.

Ta and Ta–N diffusion barriers sputtered with various N2/Ar ratios for Cu metallization

Ta and Ta–N films sputtered with pure Ar, 10%, 20%, 30%, 40%, 50%, and 60% N2/Ar gas ratios were found to be a mixture of β-Ta and bcc-Ta, bcc-Ta, bcc-TaNx, expanded bcc-TaNx, hcp-Ta2N, fcc-TaN, and fcc-TaN (nearly amorphous) phases, respectively. The resistivity was found to be lowest in samples sputtered with 10% N2/Ar and increase with nitrogen content in samples deposited with 10% to 60% N2/Ar. For Cu layers deposited on these films, the growth orientations were found to depend strongly on the microstructures of underlying Ta and Ta–N films. The Cu (111)/(200) ratio was decreased with the nitrogen content of Ta–N films.

Comparison of sampling methods for animal manure

Currently available and recently developed sampling methods for slurry and solid manure were tested for bias and reproducibility in the determination of total phosphorus and nitrogen content of samples. Sampling methods were based on techniques in which samples were taken either during loading from the hose or from the transport vehicle after loading. Most methods were unbiased. New sampling methods for slurry from the hose were substantially more reproducible than existing methods. For practical reasons, the mechanization of sampling is desirable, and to minimize the influence of human activity on sample quality, the automation of sampling is advisable.

Determination of Nitrogen as Elementary N, an Alternative to Kjeldahl

Abstract LECO FP-228 N-determinator has been tested and nitrogen contents in samples of both animal and plant origin have been measured. The results were compared to nitrogen contents obtained by Kjeldahl determinations (Kjel-foss). Reproducibility and repeatability were excellent in FP-228 (within 2%) except in samples like maize, hay, corn silage and maize silage. Good agreement was found between the two methods when analysing feeding stuff, barley, wheat, oat, soy bean, bonemeal, fishmeal, pea, molasse, chicken and lamb. Analyses of maize, hay, grass, straw, grass silage, maize silage, sugar beet and potato resulted in greater differences (>5%), FP-228 with the highest results. The differences might be explained by nitrate in a few of the samples tested, but in the other samples tested there were no obvious explanations.

The ratio of B to C hordeins in barley as estimated by high performance liquid chromatography

AbstractThe ratio of B to C hordeins was determined using high performance liquid chromatography (h.p.l.c.) for a range of spring barley cultivars and the values obtained varied from 1.79 for Kneifel to 4.15 for Goldmarker. Fine grinding of seed samples resulted in a significant increase in the quantity of protein solubilised but relatively little difference was observed in the B and C hordein ratio, which appeared to be independent of protein extraction efficiency. Increased nitrogen content significantly changed the ratio by increasing the proportion of C hordein. A highly significant correlation was found between the B and C hordein ratio and sample nitrogen content. Analysis of single seeds selected at random from within a single sample of Goldmarker revealed considerable variability in the B and C hordein ratios with values differing by over 2 units. Due to the sensitivity of the B to C hordein ratio to various environmental effects, it is unlikely that the ratio will be of great value as an unambiguous aid in the identification of barley cultivars.

The Impact of Fertilizer Use and Crop Management on Nitrogen Content of Subsurface Water Draining from Upland Agricultural Watersheds

AbstractSpring flow and stream base flow sites were sampled weekly on and adjacent to a 123‐ha agricultural watershed in the Allegheny‐Cumberland Plateau physiographic region of east‐central Ohio. Nitrogen content of samples was used to determine the influence of various N fertilizer and crop management practices on the quality of subsurface water draining from defined contributing areas.Measured nitrogen contents of spring flow were related to fertilizer N regime of the different agricultural practices investigated. Changes in land management on the area contributing to spring flow were reflected in changes in nitrogen content of water from that spring. The amount of nitrogen which was transported into the stream channel was directly related to seasonal variation in subsurface flow rate in two ways. First, the concentration of N in spring flow increased with an increase in the amount of water percolating through the overlying soil and shale. Second, the extent to which downstream quality was affected, i.e., the distance from the area of fertilizer application at which an increase in nitrogen content could be detected, also increased with the volume of flow from the springs.

細菌によるパルプ排液成分の分解 ＩＩＩ 酸素・アルカリ蒸解排液リグニンの分解

Since the lignin preparations from waste liquor of oxygen-alkali pulping (OL) have been appreciably oxidized and have an increased hydrophilic property by cooking, they were more easily affected by Pseudomonas ovalis than kraft lignin and ligninsulfonate. After incubation for 30 days, a portion of higher molecular weight of pine and beech OL were appreciably decomposed, and the nitrogen content of residual lignin increased with progress of bacterial incubation. Amino acid composition of the biodegraded lignin hydrolysate differ markedly from that of bacterial cells. It seemed that about 1020 percents of nitrogen content of biodegraded samples arised from amino acids of bacterial cells protein. Nitrogen content of the samples were almost not affected by Pronase treatment. Slight amounts of guanine and adenine arising from bacterial nucleic acids were detected by thin layer chromatography, however, there were no detectable amounts of the nucleic acids. Vanillin and syringaldehyde yielding groups of biodegraded OL decreased extremely. Therefore, 5-position condensed guaiacyl type and biphenyl type have consequently increased. Methoxyl group and phenolic hydroxyl group decreased with progress of bacterial decomposition, but, p-hydroxyphenyl group and 4-methoxy isophthalic acid type structures increased such as the case of kraft lignin. Therefore, demethoxylation of OL was caused by this bacterium.

Tension and Resin-Treatment Effects on Properties of Scoured and Mercerized Cotton Fibers and Fabrics of Different Constructions

Fabrics of printcloth weight in plain and basket weave were crosslinked with dimethylolethyleneurea to 2, 5, and 10% add-on. Specimens were dried slack or under tension before curing. The amount of crosslinking, controlled by resin pickup, produced reasonably consistent nitrogen contents in samples when other parameters were varied. Among the properties measured were fiber density, fabric thickness and area changes, fabric tensile and wrinkle recoveries, and single- fiber tenacity and tensile recovery. Relationships of properties to nitrogen contents and among various physical proper ties were frequently influenced by tension, fabric construction, and pretreatment.