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Sample records for nitrogen determination methods

  1. Method for the simultaneous determination of nitrogen, phosphorus and potassium

    International Nuclear Information System (INIS)

    Srapeniants, R.A.; Saveliev, I.B.; Kovtun, J.L.; Sidorov, A.V.; Tsagolov, K.S.

    1980-01-01

    A method for the simultaneous determination of the nitrogen, phosphorus and potassium contents of materials containing them, such as vegetable materials and fertilisers, comprises exposing samples to be analysed and standard samples to neutron irradiation, recording the spectra of gamma radiation induced in the samples, laying the samples aside for a period of time determined by the half-life of the gamma ray-emitting isotopes, again recording the spectra of the samples being analysed and those of the standard samples, superimposing the first and second spectra of the samples being analysed and standard samples and shifting them relative to each other along the energy axis, and determining the content of the elements being analysed by comparing the spectra of the samples being analysed with those of the standard samples. (author)

  2. Spectral isotopic methods of determining nitrogen and carbon in plant specimens with laser volatization

    International Nuclear Information System (INIS)

    Lazeeva, G.S.

    1986-01-01

    Methods have been devised for the local determination of nitrogen and carbon isotope compositions in plant specimens, which provide separate and joint determination. Local laser evaporation has been combined with spectroscopic determination of the isotope compositions in the gas phase. A continuous-wave CO 2 laser is preferable for the local evaporation; the carbon isotope composition may be determined directly on the sum of the evaporation products, whereas nitrogen must first be separated as N 2 . Methods have also been developed for the local determination of total nitrogen and carbon in a sample with isotope dilution on the basis of laser evaporation. In order to eliminate systematic errors in determining total carbon in plant material, an evaporation method free from a rim has been devised. These methods have been used in determining isotope concentration profiles in plant specimens grown in experiments employing labeled nitrogen and carbon

  3. Quantitative determination of nitrogen biological fixation by the N-15 isotopic method

    International Nuclear Information System (INIS)

    Basantes, Emilio; Trivelin, Paulo; Mui Tsai, Siu

    1993-01-01

    In order to quantify the biological nitrogen fixation (BNF) and to evaluate the mycorrhiza effect in the BNF, an experiment was carried on by applying 1 5 N -ammonium sulphate and mycorrhiza fungi to the soil. The treatments included legumes: mucuna negra(Stizolobium atterrinum Piper et Tracv) and caupi (Vigna unguiculoata L. Walp). Two control plants: non nodulating soybean (Glycine max L.Merril) and rice (Oryza sativa), were used for measuring the fixed N in the legumes by isotope dilution method. Both legumes and control plants assimmilated the same ammounts of nitrogen from the soil and fertilizer. The greater N content in the legumnes was determined as coming from the fixed nitrogen. Rice and non nodulating soybean showed to be good controls for measuring biological nitrogen fixation using isotopic dilution method. The values of fixed nitrogen for legumes calculated using rice as control plant were slightly greater than those with non nodulating soybean, nevertheless there were no significant statistical differences between the values. The mucuna fixed more N than caupi in both mycorrhiza treatments (76.7, 66.6 and 56. 7 per cent of N fixed, respectively). The mycorrhiza increased dry matter yield (13.84 per cent), accumulation of N in the plant(14.85 per cent N) and the biological N fixation (16.06 per cent N-fixed) in caupi

  4. A method for the determination of low nitrogen concentrations in niobium by vacuum hot extraction

    International Nuclear Information System (INIS)

    Gruenwald, W.; Haessner, F.; Schulze, K.

    1976-01-01

    A method for the vacuum hot extraction of gases without the use of crucibles and fluxes is described and applied to the determination of gas contents of high-melting-point metals at low atomic ppm. The Nb-N system is quoted as an example. The reaction vessel (after baking at 150 0 C) was evacuated by means of a turbomolecular pump at an effective rate of 240 l s -1 . Degassing was carried out in ultra-high vacuum employing a residual nitrogen partial pressure of 2 X 10 -10 Torr and liquid and/or solid samples were melted by the levitation method in a radiofrequency field. The evolved gases were detected using a quadrupole mass filter and the quantity of nitrogen evolved calculated by integrating the partial pressure over the time period at a given pumping rate independent of pressure. In addition to giving a chemical analysis of the gas-metal system at low atomic ppm, this method also enables the thermodynamic and kinetic parameters to be determined. The minimum detectable concentration of nitrogen dissolved in niobium was ca. 0.5 at. ppm, the distribution coefficient between solid and liquid niobium 0.76 with the solubility of nitrogen being unaffected by additions of carbon up to 4.5 at.%. The contamination of high purity niobium during sample preparation has also been investigated. (Auth.)

  5. Radioactivation method for simultaneous determination of nitrogen, phosphorus and potassium content in plants and fertilizers

    International Nuclear Information System (INIS)

    Srapeniants, R.A.; Saveliev, I.B.; Kovtun, J.L.; Sidorov, A.V.; Tsagolov, K.S.; Miroshnikova, N.N.

    1982-01-01

    A radioactivation method for the simultaneous determination of the nitrogen, phosphorus and potassium content in plants and fertilizers is described. Samples to be analyzed and standard samples are exposed to neutron irradiation, and the spectra of gamma radiation induced in the samples are recorded. The samples laid aside for a period of time determined by the half-life of interfering isotopes, and the spectra of the samples and standards are recorded again. The first and second spectra are superposed and shifted relative to each other along the energy axis, and the content of the elements being analyzed is determined by comparing the spectra of the samples and standards

  6. Assessment of the usefulness of the PIGE method to determine nitrogen in human blood serum

    International Nuclear Information System (INIS)

    Kupila-Rantala, T.; Hyvoenen-Dabek, M.; Raiasanen, J.; Dabek, J.T.

    1995-01-01

    Proton-induced gamma-ray emission (PIGE) analysis has been applied to the determination of total nitrogen concentration of blood sera from hospital patients. Both the reaction 14 N(p,p'γ) 14 N, E γ =2313 keV, and the reaction 15 N(p,αγ) 12 C,E γ =4439keV, have been used. From 37 patients, the range of the nitrogen concentrations obtained was 9.54-16.3 g/l with a mean of 12.0 g/l. The corresponding total protein concentrations varied between 59 and 96 g/l, measured in a clinical laboratory auto analyser using the biuret method. The range of the albumin concentrations was 29-46 g/l. The nitrogen concentrations correlated well with the total protein concentrations (r=0.802). The multiple correlation of nitrogen versus (albumin+ (total protein- albumin)) gives a coefficient of 0.175 for albumin and 0.161 for total protein- albumin. The results agree with expectations and support the potential usefulness of the rapid PIGE method for medical studies. (author). 17 refs., 3 figs

  7. Nuclear method for determination of nitrogen depth distributions in single seeds. [/sup 14/N tracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Sundqvist, B; Gonczi, L; Koersner, I; Bergman, R; Lindh, U

    1974-01-01

    (d,p) reactions in /sup 14/N were used for probing single kernels of seed for nitrogen content and nitrogen depth distributions. Comparison with the Kjeldahl method was made on individual peas and beans. The results were found to be strongly correlated. The technique to obtain depth distributions of nitrogen was also used on high- and low-lysine varieties of barley for which large differences in nitrogen distributions were found.

  8. Determination of nitrogen in PuO2-UO2 mixed oxide with fusion-TCD method

    International Nuclear Information System (INIS)

    Hiyama, Toshiaki; Takahashi, Toshio; Ohuchi, Yoshiro; Suzuki, Takeshi; Kaya, Akira

    1983-01-01

    Nitrogen in plutonium and uranium mixed oxide has been determined by several different methods. In the classical Dumas method, nitrogen is measured volumetrically. Other procedures are modifications of the Kjeldahl method in which nitrogen is converted to ammonia. All these methods are accompanied with the same problems in which the analysis takes usually 2 or 3 days with waste solutions generated. So far, the authors have tried to determine nitrogen in PuO 2 -UO 2 mixed oxide with an improved dry process, in which an impulse furnace is used to heat the sample in a graphite crucible under a helium atmosphere. Nitrogen released from the sample were separated from other gases (i.e., a large amount of carbon monoxide, very small amount of hydrogen etc.) by a combination of original two moleculer sieve columns and pre-cut system. Separated nitrogen was then detected on the basis of thermal conductivities. (author)

  9. Radioactivation method for simultaneous determination of nitrogen, phosphorus and potassium content in plants and fertilizers

    International Nuclear Information System (INIS)

    Kovtun, J.L.; Miroshnikova, N.N.; Saveliev, I.B.; Sidorov, A.V.; Srapeniants, R.A.; Tsagolov, K.S.

    1981-01-01

    According to the invention, the radioactivation method for simultaneous determination of the nitrogen, phosphorus and potassium content in plants and fertilizers consists in exposing samples to be analyzed and standard samples to neutron irradiation and recording the spectra of the gamma radiation induced in said samples, whereupon the samples are laid aside for a period of time determined by the half-life of the interfering isotope. This is followed by again recording the spectra of the samples being analyzed and of the standard samples and superposing the first and second spectra of the samples being analyzed and of the standard samples. These spectra are then shifted relative to each other along the energy axis, and the contents of the elements being analyzed are determined by thus comparing the spectra of the samples being analyzed and of the standard samples

  10. Uranium metal and uranium dioxide powder and pellets - Determination of nitrogen content - Method using ammonia-sensing electrode. 1. ed.

    International Nuclear Information System (INIS)

    1994-01-01

    This International Standard specifies an analytical method for determining the nitrogen content in uranium metal and uranium dioxide powder and pellets. It is applicable to the determination of nitrogen, present as nitride, in uranium metal and uranium dioxide powder and pellets. The concentration range within which the method can be used is between 9 μg and 600 μg of nitrogen per gram. Interference can occur from metals which form complex ammines, but these are not normally present in significant amounts

  11. A simple and rapid visual method for the determination of ammonia nitrogen in environmental waters using thymol

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, M.; Fujinaga, K.; Seike, Y.; Honda, S. [Dept. of Material Science, Interdisciplinary Faculty of Science and Engineering, Shimane University, Matsue (Japan)

    1999-11-01

    Simple visual and spectrophotometric methods for the determination of ammonia nitrogen in water are proposed, based on the color development of indothymol blue formed between ammonia and thymol. The color development was accelerated by nitroprusside to complete in 3 min. This color development is remarkably rapid compared with that of the other conventional methods with indothymol blue and indophenol blue. The concentration range of ammonia nitrogen spectrophotometrically determined was 0.04-1.2 mg/L NH{sub 4}-N. The absorbance per 1 {mu}g NH{sub 4}-N was 0.0215 (molar absorptivity = 1.51 x 10{sup 4}) at 690 nm. The visual method not using any instrument as an in situ method in field works was developed based on the optimum conditions for the established spectrophotometric method. This visual method was successfully applied to the determination of ammonia nitrogen in environmental waters. (orig.)

  12. A method for the determination of volatile ammonia in air, using a nitrogen-cooled trap and fluorometric detection

    NARCIS (Netherlands)

    Westra, H.G.; Tigchelaar, R.G.; Berden, J.A.

    2001-01-01

    A quick, cheap, and accurate method for the determination of ammonia in air is described. Ammonia and water vapor are trapped simultaneously in a gas sampling tube cooled in liquid nitrogen. Subsequently ammonia is derivatized with o-phthaldialdehyde and determined using fluorescence detection. The

  13. Use of Nitrogen-15 Isotope Method in Soils and Ground Water to Determine Potential Nitrogen Sources Affecting a Municipal Water Supply in Kansas, USA

    Science.gov (United States)

    Townsend, M. A.; Macko, S. A.

    2004-12-01

    Nitrate-N concentrations have increased to greater than 10 mg/L in a municipal water supply in western Kansas from 1995 to 2002. A study was done by the Kansas Geological Survey using the nitrogen-15 natural abundance isotope method to determine potential sources for the increasing nitrate concentrations. Preliminary results of the isotope analyses on water samples suggest that animal waste and/or denitrification enrichment has affected the water supply. Soil samples from areas near the wells that were not treated with manure show a general increase of nitrogen-15 signature (+9 to +15 \\permil) to a depth of 5 m. Soils are silt loams with measurable carbonate (0.8 to 2 % by weight) in the profile, which may permit volatilization enrichment to occur in the soil profile. Wells in the area range from 11 to 20 m in alluvial deposits with depth to water at approximately 9 m). Nitrate-N values range from 8 to 26 mg/L. Nitrogen-15 values range from (+17 to +28 \\permil) with no obvious source of animal waste near the well sites. There are potential nearby long-term sources of animal waste - an abandoned sewage treatment plant and an agricultural testing farm. One well has a reducing chemistry with a nitrate value of 0.9 mg/L and a nitrogen-15 value of +17 \\permil suggesting that alluvial sediment variation also has an impact on the water quality in the study area. The other wells show values of nitrate and nitrogen-15 that are much greater than the associated soils. The use of nitrogen-15 alone permited limited evaluation of sources of nitrate to ground water particularly in areas with carbonate in the soils. Use of oxygen-18 on nitrate will permit the delineation of the processes affecting the nitrogen in the soil profile and determination of the probable sources and the processes that have affected the nitrogen in the ground water. Final results of the nitrogen-15 and oxygen-18 analyses will be presented.

  14. Quantitative determination of heavy nitrogen by spectroscopy

    International Nuclear Information System (INIS)

    Kumazawa, Kikuo

    1974-01-01

    Explanation is made on the merits of the determination with heavy nitrogen, the principle and apparatus used for the determination, the method of production of discharge tubes, and the application of the method to several special cases. The spectra belonging to the 2nd positive system are used for the analysis of heavy nitrogen by emission spectroscopy. The spectra near 2980 A are used most often. The bandheads utilizable for the determination are 2976.8 for 14 N 2 , 2982.9 for 14 N 15 N, and 2988.6 A for 15 N 2 , respectively. The sample must be sealed in a discharge tube as nitrogen gas, at first. Mixing of impurities lowers the sensitivity of the determination. The gas pressure is adjusted 10 1-6 Torr. The preparation of gaseous nitrogen is made by either the Rittenberg or the Dumas method. When the amount of a given sample is more than 50 mg, and nitrogen is present as ammonium salt, NH 3 is converted to nitrogen by the reaction with sodium hypobromite. When nitrogen is not present as ammonium salt, Dumas' method is adopted. The amount of heavy nitrogen in the aminoacid separated by thin layer chromatography with silica gel was successfully determined by this method. Simultaneous determination of heavy nitrogen and total nitrogen was also possible by this method. (Fukutomi, T.)

  15. [Determination of the daily changes curve of nitrogen oxides in the atmosphere by digital imaging colorimetry method].

    Science.gov (United States)

    Yang, Chuan-Xiao; Sun, Xiang-Ying; Liu, Bin

    2009-06-01

    From the digital images of the red complex which resulted in the interaction of nitrite with N-(1-naphthyl) ethylenediamine dihydrochloride and P-Aminobenzene sulfonic acid, it could be seen that the solution colors obviously increased with increasing the concentration of nitrite ion. The JPEG format of the digital images was transformed into gray-scale format by origin 7.0 software, and the gray values were measured with scion image software. It could be seen that the gray values of the digital image obviously increased with increasing the concentration of nitrite ion, too. Thus a novel digital imaging colorimetric (DIC) method to determine nitrogen oxides (NO(x)) contents in air was developed. Based on the red, green and blue (RGB) tricolor theory, the principle of the digital imaging colorimetric method and the influential factors on digital imaging were discussed. The present method was successfully applied to the determination of the daily changes curve of nitrogen oxides in the atmosphere and NO2- in synthetic samples with the recovery of 97.3%-104.0%, and the relative standard deviation (RSD) was less than 5.0%. The results of the determination were consistent with those obtained by spectrophotometric method.

  16. Determination of the nitrogen concentration in epitaxial layers of GaAs /SUB 1-x/ p /SUB x/ by the optical method

    International Nuclear Information System (INIS)

    Lupal, M.V.; Klot, B; Nikhter, K.; Pikhtin, A.N.; Trapp, M.

    1986-01-01

    This paper determines the dependence of the cross section for absorption in the A /SUB N/ line of a bound exciton on the nitrogen content in the solid solution GaAs /SUB 1-x/ P /SUB x/ by comparing the results of optical measurements with the data from secondary ionic mass spectrometry, and these results are used to study the effect of technological factors on the nitrogen concentration epitaxial layers obtained by the gas-transport method. Doping was carried out with nitrogen by injecting ammonia into the reactor zone; the partial pressure of the ammonia was varied from 1 to 25 kPa. Aside from nitrogen, the authors doped the layers with shallow donor Te. It is established that the solubility of nitrogen in the solid solution decreases as the arsenic content increases when the convenient optical method for determining the nitrogen concentration in epitaxial GaAs /SUB 1-x/ P /SUB x/ layers is used

  17. Technical Note: Comparison between a direct and the standard, indirect method for dissolved organic nitrogen determination in freshwater environments with high dissolved inorganic nitrogen concentrations

    DEFF Research Database (Denmark)

    Graeber, Daniel; Gelbrecht, Jörg; Kronvang, Brian

    2012-01-01

    Research on dissolved organic nitrogen (DON) in aquatic systems with high dissolved inorganic nitrogen (DIN, the sum of NO3–, NO2– and NH4+) concentrations is often hampered by high uncertainties regarding the determined DON concentration. The reason is that DON is determined indirectly...... accuracy at high DIN : TDN ratios, we investigated the DON measurement accuracy of this standard approach according to the DIN : TDN ratio and compared it to the direct measurement of DON by size-exclusion chromatography (SEC) for freshwater systems. For this, we used standard compounds and natural samples...... separation of DON from DIN. For SEC, DON recovery rates were 91–108% for five pure standard compounds and 89–103% for two standard compounds, enriched with DIN. Moreover, SEC resulted in 93–108% recovery rates for DON concentrations of natural samples at a DIN : TDN ratio of 0.8 and the technique...

  18. Determination of nitrogen in boron carbide with the Leco UO-14 Nitrogen Determinator

    International Nuclear Information System (INIS)

    Gardner, R.D.; Ashley, W.H.; Henicksman, A.L.

    1977-11-01

    Use of various metals as fluxes for releasing nitrogen from boron carbide in the Leco Nitrogen Determinator was investigated. Metals such as iron, chromium, and molybdenum that wet the graphite crucible all promoted nitrogen release. Tin, copper, aluminum, and platinum did not wet the graphite and were of no value as fluxes. A procedure for sample handling and the resulting performance of the method are described. The precision at 0.06 to 0.6 percent nitrogen averaged 4 percent relative standard deviation

  19. Two isotopic methods for estimation of soybean nitrogen fixation

    International Nuclear Information System (INIS)

    Domenach, A.-M.; Chalamet, Alain; Pachiaudi, Christiane

    1979-01-01

    Measurements of rate of nitrogen symbiotic fixation by Soybean were determined by two different methods: variations in the natural abundance of 15 N in plants; use of 'A' value determined from labelled nitrogen applications to the soil. The results from both methods were in good agreement. Rates of fixed nitrogen were similar when using non nodulated Soybean or Ray-Grass as reference [fr

  20. Two isotopic methods for estimation of soybean nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    Domenach, A M; Chalamet, A; Pachiaudi, C [Lyon-1 Univ., 69 - Villeurbanne (France)

    1979-07-16

    Measurements of rate of nitrogen symbiotic fixation by Soybean were determined by two different methods: variations in the natural abundance of /sup 15/N in plants; use of 'A' value determined from labelled nitrogen applications to the soil. The results from both methods were in good agreement. Rates of fixed nitrogen were similar when using non nodulated Soybean or Ray-Grass as reference.

  1. Nitrogen determination on tomato ( Lycopersicon esculentum Mill ...

    African Journals Online (AJOL)

    In order to investigate the effectiveness of a new method based on color image analysis and the Minolta SPAD-502 chlorophyll meter for the diagnosis of nitrogen deficiencies of tomato seedlings, a field experiment was conducted. In this study, five levels of nitrogen fertilization were established so as to induce nitrogen ...

  2. Carbon and nitrogen determination in Zr by photon or proton activation analysis. Comparison between the results obtained by this method and other analytical techniques

    International Nuclear Information System (INIS)

    Petit, J.; Gosset, J.; Engelmann, C.

    1977-01-01

    Carbon and nitrogen are determined by the following nuclear reactions: 12 C(γ,n) 11 C and 14 N(p,α) 11 C. The performances of the method and the main interferences are considered. The process developed for the separation of carbon-11 from zirconium is described and its efficiency evaluated. The results obtained are compared with those given by different laboratories using various analytical techniques [fr

  3. A new method for the determination of the nitrogen content of nitrocellulose based on the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis

    International Nuclear Information System (INIS)

    Alinat, Elodie; Delaunay, Nathalie; Archer, Xavier; Mallet, Jean-Maurice; Gareil, Pierre

    2015-01-01

    Highlights: • New insights into the nitrocellulose alkaline denitration mechanism. • Linear correlation for molar ratio of nitrite-to-nitrate ions and nitrogen content. • Capillary electrophoresis monitoring of nitrite and nitrate ions. • Applications to explosive and non-explosive nitrocellulose-containing samples. • Improved performances (including safety) over classical methods. - Abstract: A new method was proposed to determine the nitrogen content of nitrocelluloses (NCs). It is based on the finding of a linear relationship between the nitrogen content and the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis. Capillary electrophoresis was used to monitor the concentration of nitrite and nitrate ions. The influences of hydrolysis time and molar mass of NC on the molar ratio of nitrite-to-nitrate ions were investigated, and new insights into the understanding of the alkaline denitration mechanism of NCs, underlying this analytical strategy is provided. The method was then tested successfully with various explosive and non-explosive NC-containing samples such as various daily products and smokeless gunpowders. Inherently to its principle exploiting a concentration ratio, this method shows very good repeatability in the determination of nitrogen content in real samples with relative standard deviation (n = 3) inferior to 1.5%, and also provides very significant advantages with respect to sample extraction, analysis time (1 h for alkaline hydrolysis, 3 min for electrophoretic separation), which was about 5 times shorter than for the classical Devarda's method, currently used in industry, and safety conditions (no need for preliminary drying NC samples, mild hydrolysis conditions with 1 M sodium hydroxide for 1 h at 60 °C)

  4. A new method for the determination of the nitrogen content of nitrocellulose based on the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Alinat, Elodie, E-mail: elodie.alinat@chimie-paristech.fr [PSL Research University, Chimie ParisTech, Laboratory of Physicochemistry of Electrolytes, Colloids and Analytical Sciences (PECSA), 11 rue Pierre et Marie Curie, 75005 Paris (France); Central Laboratory of Police Prefecture (LCPP), 39 bis rue de Dantzig, 75015 Paris (France); CNRS, UMR 7195 PECSA, 11 rue Pierre et Marie Curie, 75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, F-75005 Paris (France); Delaunay, Nathalie, E-mail: nathalie.delaunay@espci.fr [PSL Research University, Chimie ParisTech, Laboratory of Physicochemistry of Electrolytes, Colloids and Analytical Sciences (PECSA), 11 rue Pierre et Marie Curie, 75005 Paris (France); CNRS, UMR 7195 PECSA, 11 rue Pierre et Marie Curie, 75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, F-75005 Paris (France); Archer, Xavier, E-mail: xavier.archer@interieur.gouv.fr [Central Laboratory of Police Prefecture (LCPP), 39 bis rue de Dantzig, 75015 Paris (France); Mallet, Jean-Maurice, E-mail: jean-maurice.mallet@es.fr [École Normale Supérieure-PSL Research University, Département de Chimie, 24 rue Lhomond, 75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, F-75005 Paris (France); CNRS, UMR 7203 LBM, F-75005 Paris (France); Gareil, Pierre, E-mail: pierre.gareil@chimie-paristech.fr [PSL Research University, Chimie ParisTech, Laboratory of Physicochemistry of Electrolytes, Colloids and Analytical Sciences (PECSA), 11 rue Pierre et Marie Curie, 75005 Paris (France); CNRS, UMR 7195 PECSA, 11 rue Pierre et Marie Curie, 75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, F-75005 Paris (France)

    2015-04-09

    Highlights: • New insights into the nitrocellulose alkaline denitration mechanism. • Linear correlation for molar ratio of nitrite-to-nitrate ions and nitrogen content. • Capillary electrophoresis monitoring of nitrite and nitrate ions. • Applications to explosive and non-explosive nitrocellulose-containing samples. • Improved performances (including safety) over classical methods. - Abstract: A new method was proposed to determine the nitrogen content of nitrocelluloses (NCs). It is based on the finding of a linear relationship between the nitrogen content and the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis. Capillary electrophoresis was used to monitor the concentration of nitrite and nitrate ions. The influences of hydrolysis time and molar mass of NC on the molar ratio of nitrite-to-nitrate ions were investigated, and new insights into the understanding of the alkaline denitration mechanism of NCs, underlying this analytical strategy is provided. The method was then tested successfully with various explosive and non-explosive NC-containing samples such as various daily products and smokeless gunpowders. Inherently to its principle exploiting a concentration ratio, this method shows very good repeatability in the determination of nitrogen content in real samples with relative standard deviation (n = 3) inferior to 1.5%, and also provides very significant advantages with respect to sample extraction, analysis time (1 h for alkaline hydrolysis, 3 min for electrophoretic separation), which was about 5 times shorter than for the classical Devarda's method, currently used in industry, and safety conditions (no need for preliminary drying NC samples, mild hydrolysis conditions with 1 M sodium hydroxide for 1 h at 60 °C)

  5. Single gas chromatography method with nitrogen phosphorus detector for urinary cotinine determination in passive and active smokers

    Directory of Open Access Journals (Sweden)

    Lusiane Malafatti

    2010-12-01

    Full Text Available Nicotine is a major addictive compound in cigarettes and is rapidly and extensively metabolized to several metabolites in humans, including urinary cotinine, considered a biomarker due to its high concentration compared to other metabolites. The aim of this study was to develop a single method for determination of urinary cotinine, in active and passive smokers, by gas chromatography with a nitrogen phosphorus detector (GC-NPD. Urine (5.0 mL was extracted with 1.0 mL of sodium hydroxide 5 mol L-1, 5.0 mL of chloroform, and lidocaine used as the internal standard. Injection volume was 1 μL in GC-NPD. Limit of quantification was 10 ng mL-1. Linearity was evaluated in the ranges 10-1000 ng mL-1 and 500-6000 ng mL-1, with determination coefficients of 0.9986 and 0.9952, respectively. Intra- and inter-assay standard relative deviations were lower than 14.2 %, while inaccuracy (bias was less than +11.9%. The efficiency of extraction was greater than 88.5%. Ruggedness was verified, according to Youden's test. Means of cotinine concentrations observed were 2,980 ng mL-1 for active smokers and 132 ng mL-1, for passive smokers. The results revealed that satisfactory chromatographic separation between the analyte and interferents was obtained with a ZB-1 column. This method is reliable, precise, linear and presented ruggedness in the range evaluated. The results suggest that it can be applied in routine analysis for passive and active smokers, since it is able to quantify a wide range of cotinine concentrations in urine.A nicotina é uma substância presente no cigarro capaz de causar dependência, sendo biotransformada em vários metabólitos nos seres humanos, dentre eles a cotinina urinária, que é considerada um indicador biológico de exposição à nicotina, devido a suas altas concentrações, comparado a outras matrizes. Assim, o objetivo deste estudo foi desenvolver um único método para determinação de cotinina urinária, em amostras de

  6. The determination of surface of powders by BET method using nitrogen and krypton with computer calculation of the results

    International Nuclear Information System (INIS)

    Dembinski, W.; Zlotowski, T.

    1973-01-01

    A computer program written in FORTRAN language for calculations of final results of specific surface analysis based on BET theory has been described. Two gases - nitrogen and krypton were used. A technical description of measuring apparaturs is presented as well as theoretical basis of the calculations together with statistical analysis of the results for uranium compounds powders. (author)

  7. A simple and rapid gas chromatographic method for the determination of dissolved deuterium and nitrogen in heavy water coolant of a nuclear reactor

    International Nuclear Information System (INIS)

    Nair, B.K.S.

    1976-01-01

    A known volume of a heavy water sample is equilibrated with a known volume of pure helium gas at atmospheric pressure in a sample tube. The dissolved gases evolve into the helium and distribute themselves between the gaseous and liquid phases according to their equilibrium partial pressures. These partial pressures of the gases in the equilibrium gas mixture are determined by analysing it gas-chromatographically. From these analytical data and the absorption coefficients of deuterium and nitrogen, their original concentrations in heavy water are calculated. Corrections for the increase in the total pressure of the gaseous phase owing to evolved gases are calculated and found to be negligible. Air contamination during sampling and analysis can be detected by the presence of the oxygen peak in the chromatogram and corrected for. The calculation is facilitated by programming it on an electronic calculator. The method is much simpler and faster than the vacuum method usually applied for this analysis. One determination can be completed in about an hour. The average deviation and standard deviation have been estimated at 0.19 ml/litre heavy water and 0.25 ml/litre heavy water respectively in deuterium, and 0.36 and 0.68 ml/litre in nitrogen. (author)

  8. Determination of Meteorite Porosity Using Liquid Nitrogen

    Science.gov (United States)

    Kohout, T.; Kletetschka, G.; Pesonen, L. J.; Wasilewski, P. J.

    2005-01-01

    We introduce a new harmless method for porosity measurement suitable for meteorite samples. The method is a modification of the traditional Archimedean method based on immersion of the samples in a liquid medium like water or organic liquids. In our case we used liquid nitrogen for its chemically inert characteristics.

  9. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

    Science.gov (United States)

    Patton, Charles J.; Kryskalla, Jennifer R.

    2003-01-01

    Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September 30, 2002. Data for this study were obtained from about 2,100 surface- and ground-water samples that were analyzed for Kjeldahl nitrogen and Kjeldahl phosphorus in the course of routine operations at the USGS National Water Quality Laboratory (NWQL). These samples were analyzed independently for total nitrogen and total phosphorus using an alkaline persulfate digestion method developed by the NWQL Methods Research and Development Program. About half of these samples were collected during nominally high-flow (April-June) conditions and the other half were collected during nominally low-flow (August-September) conditions. The number of filtered and whole-water samples analyzed from each flow regime was about equal.By operational definition, Kjeldahl nitrogen (ammonium + organic nitrogen) and alkaline persulfate digestion total nitrogen (ammonium + nitrite + nitrate + organic nitrogen) are not equivalent. It was necessary, therefore, to reconcile this operational difference by subtracting nitrate + nitrite concentra-tions from alkaline persulfate dissolved and total nitrogen concentrations prior to graphical and statistical comparisons with dissolved and total Kjeldahl nitrogen concentrations. On the basis of two-population paired t-test statistics, the means of all nitrate-corrected alkaline persulfate nitrogen and Kjeldahl nitrogen concentrations (2,066 paired results) were significantly different from zero at the p = 0.05 level. Statistically, the means of Kjeldahl nitrogen concentrations were greater than those of nitrate-corrected alkaline persulfate nitrogen concentrations. Experimental evidence strongly

  10. Non-destructive determination of nitrogen in malting barleys by instrumental photon activation analysis and its comparison with the Dumas method

    Czech Academy of Sciences Publication Activity Database

    Krausová, Ivana; Mizera, Jiří; Dostálek, P.; Řanda, Zdeněk

    2018-01-01

    Roč. 124, č. 1 (2018), s. 4-8 ISSN 0046-9750 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : nitrogen * instrumental photon activation analysis * Dumas method * malting barley Subject RIV: GM - Food Processing OBOR OECD: Food and beverages Impact factor: 0.859, year: 2016

  11. Determination of nitrogen in UO2 pellets by hot extraction-TCD method without using flux material and evaluation of associated measurement uncertainties

    International Nuclear Information System (INIS)

    Begum, Zahida; Balaji Rao, Y.; Subba Rao, Y.

    2015-01-01

    Presence of non metallic impurity elements like nitrogen above the specified limit of 75 ppm (max.) in fuel pellets affects the sintered density of fuel and also effect the Zircaloy fuel clad by forming brittle nitride phase. Hence, estimation of nitrogen plays an important role in qualifying the fuel material. Conventionally, Kjeldahl steam distillation followed by UV-Visible Spectro-photometric method has been widely employed for the estimation of nitrogen in UO 2 pellets. However, inherent chemical treatment processes causes the blank variations and provides the scope for uncertainty in measurements apart from being time consuming method. This makes Kjeldahl method as an un-attractive choice for any industrial lab where high analytical loads usually exist to meet the production targets and also where urgency for quick analytical feedback is an issue. In view of this, a simple, rapid and reliable method using A LECO Model TN- 600 Nitrogen analyzer based on Hot Extraction (HT) without adding any flux material followed by Thermal Conductivity Detection (TCD) has been developed for routine analysis. Several flux materials like Pt or Ni are used to bring down the temperature of extraction due to formation of stable uranium nitrides and temperatures of 2500°C is maintained for quantitative extraction. However usage of flux materials leads to several practical problems in analysis like deposition of uranium carbide dust onto the upper electrode requiring tedious cleaning and even sometimes causing the breakage of crucibles during the analysis. Thus an attempt has been made to increase the temperatures closer to 3000°C without using flux. Working temperature of 2900°C was arrived by plotting quantity of nitrogen extracted with temperature of extraction and flattening of plot took place at 2900°C

  12. Isotopic dilution methods to determine the gross transformation rates of nitrogen, phosphorus, and sulfur in soil: a review of the theory, methodologies, and limitations

    International Nuclear Information System (INIS)

    Di, H. J.; Cameron, K. C.; McLaren, R. G.

    2000-01-01

    The rates at which nutrients are released to, and removed from, the mineral nutrient pool are important in regulating the nutrient supply to plants. These nutrient transformation rates need to be taken into account when developing nutrient management strategies for economical and sustainable production. A method that is gaining popularity for determining the gross transformation rates of nutrients in the soil is the isotopic dilution technique. The technique involves labelling a soil mineral nutrient pool, e.g. NH 4 + , NO 3 - , PO 4 3- , or SO 4 2- , and monitoring the changes with time of the size of the labelled nutrient pool and the excess tracer abundance (atom %, if stable isotope tracer is used) or specific activity (if radioisotope is used) in the nutrient pool. Because of the complexity of the concepts and procedures involved, the method has sometimes been used incorrectly, and results misinterpreted. This paper discusses the isotopic dilution technique, including the theoretical background, the methodologies to determine the gross flux rates of nitrogen, phosphorus, and sulfur, and the limitations of the technique. The assumptions, conceptual models, experimental procedures, and compounding factors are discussed. Possible effects on the results by factors such as the uniformity of tracer distribution in the soil, changes in soil moisture content, substrate concentration, and aeration status, and duration of the experiment are also discussed. The influx and out-flux transformation rates derived from this technique are often contributed by several processes simultaneously, and thus cannot always be attributed to a particular nutrient transformation process. Despite the various constraints or possible compounding factors, the technique is a valuable tool that can provide important quantitative information on nutrient dynamics in the soil-plant system. Copyright (2000) CSIRO Publishing

  13. Nitrogen utilization efficiency and nitrogen nutrition of rice crops at MADA using the microplot nitrogen balance method

    International Nuclear Information System (INIS)

    Ahmad Nazrul Abd Wahid; Abdul Razak Ruslan; Latiffah Norddin; Hazlina Abdullah; Khairuddin Abdul Rahim

    2004-01-01

    Nitrogen (N) is a very important nutrient for rice crops and is a main component of protein. Nitrogen is essential in the production of plant chlorophyll and involves in vegetative and fruit growth and development processes. Nitrogen is a critical input and exert high cost in rice crop production. Nitrogen fertilizer is not fully utilised by the rice crop; some is lost due the processes of vaporization, hydrolysis, erosion, leaching and used by other plants and microorganisms. Several agronomic practices have been studied and adopted in this country with the purpose of increasing the efficiency nitrogen fertilizer utilization and thus, reducing the output cost for rice crops. The microplot nitrogen balance method is one of the methods used to determine uptake efficiency of nitrogen fertilizers by rice crops. In this research, the microplot of 1 m x 1 m squares in paddy plot were used, to ensure that sequential sampling was done at predetermined areas. Scheduled monthly sampling of soil and rice crops was conducted until the mature stage, harvest and post-harvest period. This MINT-MADA cooperative project contains the elements of information sharing on fertilizer efficiency measurement methods by using the N-15 isotopic tracer technique and the N-balance technique in soil, besides the cooperation on use of infrastructure and facilities, expertise and labour. (Author)

  14. Total Protein Content Determination of Microalgal Biomass by Elemental Nitrogen Analysis and a Dedicated Nitrogen-to-Protein Conversion Factor

    Energy Technology Data Exchange (ETDEWEB)

    Laurens, Lieve M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Olstad-Thompson, Jessica L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Templeton, David W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-04-02

    Accurately determining protein content is important in the valorization of algal biomass in food, feed, and fuel markets, where these values are used for component balance calculations. Conversion of elemental nitrogen to protein is a well-accepted and widely practiced method, but depends on developing an applicable nitrogen-to-protein conversion factor. The methodology reported here covers the quantitative assessment of the total nitrogen content of algal biomass and a description of the methodology that underpins the accurate de novo calculation of a dedicated nitrogen-to-protein conversion factor.

  15. Determination of carbon and nitrogen in silicon and germanium

    International Nuclear Information System (INIS)

    Gebauhr, W.; Martin, J.

    1975-01-01

    The essential aim of this study is to examine the various technical and economic problems encountered in the determination of carbon and nitrogen in silicon and germanium, for this is in a way an extension of the discussion concerning the presence of oxygen in these two elements. The greater part of the study is aimed at drawing up a catalogue of the methods of analysis used and of the results obtained so far

  16. Development of a technique using MCNPX code for determination of nitrogen content of explosive materials using prompt gamma neutron activation analysis method

    Energy Technology Data Exchange (ETDEWEB)

    Nasrabadi, M.N., E-mail: mnnasrabadi@ast.ui.ac.ir [Department of Nuclear Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Bakhshi, F.; Jalali, M.; Mohammadi, A. [Department of Nuclear Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of)

    2011-12-11

    Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma 10.8 MeV following radioactive neutron capture by {sup 14}N nuclei. We aimed to study the feasibility of using field-portable prompt gamma neutron activation analysis (PGNAA) along with improved nuclear equipment to detect and identify explosives, illicit substances or landmines. A {sup 252}Cf radio-isotopic source was embedded in a cylinder made of high-density polyethylene (HDPE) and the cylinder was then placed in another cylindrical container filled with water. Measurements were performed on high nitrogen content compounds such as melamine (C{sub 3}H{sub 6}N{sub 6}). Melamine powder in a HDPE bottle was placed underneath the vessel containing water and the neutron source. Gamma rays were detected using two NaI(Tl) crystals. The results were simulated with MCNP4c code calculations. The theoretical calculations and experimental measurements were in good agreement indicating that this method can be used for detection of explosives and illicit drugs.

  17. Determination of nitrite, nitrate and total nitrogen in vegetable samples

    Directory of Open Access Journals (Sweden)

    Manas Kanti Deb

    2007-04-01

    Full Text Available Yellow diazonium cation formed by reaction of nitrite with 6-amino-1-naphthol-3-sulphonic acid is coupled with β-naphthol in strong alkaline medium to yield a pink coloured azo dye. The azo-dyes shows absorption maximum at 510 nm with molar absorptivity of 2.5 ×104 M-1 cm-1. The dye product obeys Beer's law (correlation coefficient = 0.997, in terms of nitrite concentration, up to 2.7 μg NO2 mL-1. The above colour reaction system has been applied successfully for the determination of nitrite, nitrate and total nitrogen in vegetable samples. Unreduced samples give direct measure for nitrite whilst reduction of samples by copperized-cadmium column gives total nitrogen content and their difference shows nitrate content in the samples. Variety of vegetables have been tested for their N-content (NO2-/NO3-/total-N with % RSD ranging between 1.5 to 2.5 % for nitrite determination. The effects of foreign ions in the determination of the nitrite, nitrate, and total nitrogen have been studied. Statistical comparison of the results with those of reported method shows good agreement and indicates no significant difference in precision.

  18. Effect of nitrogen source and acclimatization on specific growth rates of microalgae determined by a high-throughput in vivo microplate autofluorescence method

    DEFF Research Database (Denmark)

    Podevin, Mike; De Francisci, Davide; Holdt, Susan Løvstad

    2015-01-01

    SGRs of the second and third cultivations. ANOVA of SGRs in the acclimatized second and third cultivations revealed preferences for nitrogen sources among most of the algae; C. vulgaris preferred sodiumnitrate over other nitrogen sources, A. protothecoides adapted to urea after no growth in the first...

  19. Determinação das formas de nitrogênio e nitrogênio total em rochas-reservatório de petróleo por destilação com arraste de vapor e método do indofenol Determination of nitrogen forms and total nitrogen in petroleum reservoir rocks by steam distillation and the indophenol method

    Directory of Open Access Journals (Sweden)

    Lílian Irene Dias da Silva

    2006-02-01

    Full Text Available Several extraction procedures are described for the determination of exchangeable and fixed ammonium, nitrate + nitrite, total exchangeable nitrogen and total nitrogen in certified reference soils and petroleum reservoir rock samples by steam distillation and indophenol method. After improvement of the original distillation system, an increase in worker safety, a reduction in time consumption, a decrease of 73% in blank value and an analysis without ammonia loss, which could possibly occur, were achieved. The precision (RSD < 8%, n = 3 and the detection limit (9 mg kg-1 NH4+-N are better than those of published procedures.

  20. An efficient absorbing system for spectrophotometric determination of nitrogen dioxide

    Science.gov (United States)

    Kaveeshwar, Rachana; Amlathe, Sulbha; Gupta, V. K.

    A simple and sensitive spectrophotometric method for determination of atmospheric nitrogen dioxide using o-nitroaniline as an efficient absorbing, as well as diazotizing, reagent is described. o-Nitroaniline present in the absorbing medium is diazotized by the absorbed nitrite ion to form diazonium compound. This is later coupled with 1-amino-2-naphthalene sulphonic acid (ANSA) in acidic medium to give red-violet-coloured dye,having λmax = 545 nm. The isoamyl extract of the red azo dye has λmax = 530 nm. The proposed reagents has ≈ 100% collection efficiency and the stoichiometric ratio of NO 2:NO 2- is 0.74. The other important analytical parameters have been investigated. By employing solvent extraction the sensitivity of the reaction was increased and up to 0.03 mg m -3 nitrogen dioxide could be estimated.

  1. The determination of nitrogen dioxide in ambient air with free hanging filters as passive samplers, and a new calibration method using fritted bubblers

    NARCIS (Netherlands)

    Heeres, P.; Setiawan, R.; Krol, M.C.; Adema, E.H.

    2009-01-01

    This paper describes two new methods for the determination of NO2 in the ambient air. The first method consists of free hanging filters with a diameter of 2.5 cm as passive samplers. The filters are impregnated with triethanolamine to bind NO2. With standard colorimetrical analysis, the amount of

  2. Determination of aluminium nitride or free nitrogen in low carbon steel

    International Nuclear Information System (INIS)

    Guetaz, V.; Soler, M.; Massardier, V.; Merlin, J.; Ravaine, D.

    2001-01-01

    As the aluminium nitrides play an important role in the manufacturing of steel sheets, a specific methodology was developed based on the thermoelectric power (TEP) technique, in order to determine the AIN nitrogen by an indirect method. The free nitrogen was determined and then the AIN nitrogen was calculated by the difference between the total nitrogen and the free nitrogen. Indeed, it is easier to determine the dissolved nitrogen, the content of which gradually decreases during the AIN precipitation, than the AIN nitrogen. A low carbon aluminium killed steel was employed with 580 ppm of aluminium and 50 ppm of nitrogen. A comparison of the results obtained by TEP with those obtained by other techniques (hot hydrogen extraction, electrochemical dissolution followed by a mineralization, electrochemical dissolution followed by a sodic decomposition and the Beeghly method) was conducted, in order to determine a reliable technique likely to quantify the amount of aluminium nitrides in aluminium killed steels. With these techniques, it is possible to determine either free nitrogen or precipitated nitrogen. From an experimental point of view, the precipitation kinetics of AIN was followed during an annealing performed at 973 K (700 C) by TEP and then different precipitation states of AIN were investigated to compare the different techniques: three annealing states (when no nitrogen, half the nitrogen and the total nitrogen has precipitated) and two soaking states (1403 and 1523 K). Thus, it was possible to compare states where the AIN precipitates are in various forms (different shapes, crystallographic structures, sizes, distributions in the matrix). This work showed that the quantification by TEP, hot hydrogen extraction and electrochemical dissolution followed by a mineralization seem reliable whereas the Beeghly method gives good results only for the precipitates formed at high temperatures. In contrast, the quantification by electrochemical dissolution followed by

  3. Determining pomegranate water and nitrogen requirements with drip irrigation

    Science.gov (United States)

    Despite being an ancient crop there is limited knowledge on the water and nitrogen (N) requirements of pomegranate. We conducted research at the University of California, Kearney Agricultural Research and Extension Center (KARE) to determine the water and nitrogen requirements of a developing pomegr...

  4. The determination of nitrogen dioxide in ambient air with free hanging filters as passive samplers, and a new calibration method using fritted bubblers.

    Science.gov (United States)

    Heeres, Paul; Setiawan, Rineksa; Krol, Maarten Cornelis; Adema, Eduard Hilbrand

    2009-12-01

    This paper describes two new methods for the determination of NO(2) in the ambient air. The first method consists of free hanging filters with a diameter of 2.5 cm as passive samplers. The filters are impregnated with triethanolamine to bind NO(2). With standard colorimetrical analysis, the amount of NO(2) on the filters is determined. The second method is performed with fritted bubblers filled with Saltzman reagent, where, with a special procedure the absorption efficiencies of the bubblers are determined using ambient air, without the use of standard gases and electronic analytical instruments. The results of the bubblers are used to calibrate the free hanging filters. The two methods were applied simultaneously in the city of Yogyakarta, Indonesia. The methods are inexpensive and very well suited for use in low-budget situations. A characteristic of the free filter is the Sampling Volume, SV. This is the ratio of the amount of NO(2) on the filter and the ambient concentration. With the filter used in this study, the amount of triethanolamine and exposure time, the SV is 0.0166 m(3). The sampling rate (SR) of the filter, 4.6 cm(3)/s, is high. Hourly averaged measurements are performed for 15 hours per day in four busy streets. The measured amounts of NO(2) on the filters varied between 0.57 and 2.02 microg NO(2), at ambient air concentrations of 32 to 141 microg/m(3) NO(2). During the experiments the wind velocity was between 0.2 and 2.0 m/s, the relative humidity between 24 and 83 % and the temperature between 295 K and 311 K. These variations in weather conditions have no influence on the uptake of NO(2).

  5. Comparison of 14 MeV neutron activation analysis and competitive methods for determination of oxygen, nitrogen, silicon, fluorine and other elements

    International Nuclear Information System (INIS)

    Bild, R.W.

    1986-01-01

    14 MeV neutron activation analysis (14 MeV NAA) makes use of small particle accelerators to produce 14 MeV neutrons from the D-T reaction. The neutrons produce radioactive isotopes in samples by the reactions (n,p), (n,2n) and (n,α). Gamma rays emitted are counted to determine the amount of the target element present. Major applications have been determination of total O, N or Si in solid and liquid matrices, but the technique can also be applied to determine concentrations of about 30 other elements including F, Cl, Al, P and Mg. Detection limits are a few micrograms in the best cases and milligrams for most others. The method has advantages of being nondestructive, fast and insensitive to sample inhomogeneities. It lends itself especially well to sequential analysis of the same sample by several techniques and to samples that are difficult to dissolve. Portable generators have been applied to industrial situations and to well logging. Major disadvantages are the necessity to house a radiation producing instrument, the cost of the equipment and the lack of useful neutron reactions for some important elements. Accuracy (typically +-7 to 10% relative) and precision (+-1 to 5% relative) are comparable to competing techniques. For determination of low levels of O and N in most metals inert gas fusion is more rapid and sensitive; elemental analyzer is more sensitive for O and N in organics. Wet chemical methods rarely have any advantage over 14 MeV NAA for solid samples when concentrations are in the detection limit range of the 14 MeV NAA methods. Future developments in the field will come in the areas of simpler, more portable and higher neutron output generator designs. 66 refs

  6. Determination of oxygen and nitrogen in coal by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Hamrin, C.E. Jr.; Johannes, A.H.; James, W.D. Jr.; Sun, G.H.; Ehmann, W.D.

    1979-01-01

    The purpose of this study was to measure oxygen and nitrogen in coals using instrumental neutron activation analysis. For six U.S. coals total oxygen ranged from 9.4 to 28.7% and total nitrogen varied from 0.72 to 1.61%. To obtain values of organic oxygen and nitrogen either a low-temperature-ashing (LTA) method or an acid-treatment (AT) method was suitable for bituminous coals. The mean difference of the experimentally determined values (Osub(dmmf))sub(LTA) - (Osub(dmmf))sub(AT) = -0.82, s = 0.51, [dmmf = dry, mineral-matter-free basis], was found to be statistically significant at the 95% confidence level, but the comparable difference for nitrogen was not. By the LTA method oxygen and nitrogen on the dmmf basis for bituminous coals showed no statistically significant difference with calculated dmmf values. Nitrogen was detected in all the LTAs varying from 0.38 to 1.67%. Formation of insoluble CaF 2 in the acid-treatment method caused an interference in the nitrogen determination due to the 19 F (n, 2n) 18 F reaction but was correctable. In addition, recoil proton reactions on C and O leading to the formation of 13 N must be accounted for in all nitrogen determinations in the coal matrix. (author)

  7. On the problem of activation determination of nitrogen in petroleum

    International Nuclear Information System (INIS)

    Botvina, A.Ya.; Kazachevskij, I.V.; Sokol'skij, V.V.

    1974-01-01

    The determination of nitrogen in individual hydrocarbon feedstocks and petroleums by irradiation with fast neutrons was discussed, and the N content of 12 Kazakh petroleums was determined by this method, ranging from 0.062% in Martyshi petroleum to 0.173% in Kumsai P 1 petroelum. The amount of 13 N formed in secondary reactions with protons, designated ''false'' N, was shown to depend linearly on Wsub(C)Wsub(H)Rsub(p), where Wsub(H) and Wsub(C) are the relative weight contents of H and C in a given substance respectively, and Rsub(p) is the proton path. The amounts of ''false'' N were determined by the method of A. Botvina et al (1971), and were tabulated along with values of Rsub(p) and Wsub(C)Wsub(H)Rsub(p) for 5 materials. The simultaneous determination of C, N, and O, proposed by T. Blankova and V. Rusyaev (1971) was not considered worthwhile because C and H could be determined only within 10-15% by the method

  8. Utilization of tritiated water dilution technique in determination of nitrogen partitioning in cashmere goats

    International Nuclear Information System (INIS)

    Wang Linfeng; Yang Gaiqing; Liu Ping; Zhang Shijun

    2010-01-01

    In order to investigate nitrogen partitioning in local cashmere goats, six Inner Mogolia White Cashmere goats between 2 to 2.5 years old were used to determine the nitrogen partitioning in cashmere goats. The total retained nitrogen (TN) in body, distribution of body nitrgen and hair nitrogen were measured by general digestive and metabolism method combined with tritiated water dilution technique. Results showed that the combined methods were ideal for determining body nitrgen (BN) and hair nitrogen (fur nitrogen, FN) of Cashmere goats. There were obvious significance between BN and FN in different seasons. In telogen, BN and FN partitioning was 75.7% ± 0.62% and 24.3% ± 0.62%, respectively. Whereas, it changed to 66.6% ± 2.2% and 33.4% ± 2.2% in anagen. BN partitioning decreased when the season changed from telogen to anagen, while FN partitioning increased, which indicated that more nitrogen substance was partitioned to body growth in telogen, and more nitrogen substance was distribute to cashmere growth in anagen. These transformation were related to the changing of photoperiod and some hormones, such as melatonin (MT), prolactin (PRL) and IGF-I. It could be concluded that tritiated water dilution technique can be used to detect body protein content as well as BN, combining general digestive and metabolism experiment, FN partitoning can be determined. BN and FN partitoning varied with the season in cashmere goats because of hormones changing. (authors)

  9. Determination method of radiostrontium

    International Nuclear Information System (INIS)

    1984-01-01

    This manual provides determination methods of strontium-90 and strontium-89 in the environment released from nuclear facilities, and it is a revised edition of the previous manual published in 1974. As for the preparation method of radiation counting sample, ion exchange method, oxalate separation method and solvent extraction method were adopted in addition to the method of fuming nitric acid separation adopted in the previous edition. Strontium-90 is determined by the separation and radioactivity determination of yttrium-90 in radioequilibrium with strontium-90. Strontium-89 is determined by subtraction of radioactivity of strontium-90 plus yttrium-90 from gross radioactivity of isolated strontium carbonate. Radioactivity determination should be carried out with a low-background 2 π-gas-flow counting system for the mounted sample on a filter having a chemical form of ferric hydroxide, yttrium oxalate or strontium carbonate. This manual describes sample preparation procedures as well as radioactivity counting procedures for environmental samples of precipitates as rain or snow, airborne dust, fresh water, sea water and soil, and also for ash sample made from biological or food samples such as grains, vegetables, tea leaves, pine needle, milk, marine organisms, and total diet, by employing a method of fuming nitric acid separation, ion exchange separation, oxalate precipitate separation or solvent extraction separation (only for an ash sample). Procedures for reagent chemicals preparation is also attached to this manual. (Takagi, S.)

  10. Spectrometric determination of ammonium-nitrogen with quinol in ...

    African Journals Online (AJOL)

    Quinol is proposed as a reagent for the spectrometric determination of ammonium-nitrogen (NH4+-N) in aqueous medium. Quinol forms a pink complex with ammonium salt in aqueous medium. Hydrogen peroxide is needed for colour accentuation. The quinol/ammonium charge transfer complex has absorption maximum ...

  11. Determination of atmospheric nitrogen dioxide by sampling with impregnated filters

    International Nuclear Information System (INIS)

    Galiano, J.A.; Palomares, F.

    1978-01-01

    The performance of filters impregnated with triethanolamine for the collection and subsequent determination of atmospheric nitrogen dioxide is studied taking into account the influence of several parameters: storage of filters, reagents, elapsed time, sampling efficiency, etc. The results obtained for sampling times of 24 hours are satisfactory. (author) [es

  12. Continuous determination of nitric oxide and nitrogen dioxide in the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Yanagisawa, S; Yamate, N; Mitsuzawa, S; Mori, M

    1966-10-01

    Continuous determinations of nitric oxide and nitrogen dioxide in that atmospheric air by the use of a modified Saltzman reagent is described. Measurement was made intermittently, once every 30 min., by an automatic continuous analyzer equipped with a single-path colorimeter. The response of the analyzer was obtained as an average of the concentration of nitrogen oxides over a period of 25 min. Two bubblers were used for absorbing nitrogen oxides into the modified Saltzman reagent, whose transmittance was measured for the determination. One bubbler was designed to absorb nitrogen dioxide, and the other, nitric oxide plus nitrogen dioxide after the oxidation of the nitric oxide by permanganate. The oxidizing efficiency of the permanganate was 96-100%. The acetic acid in the Saltzman reagent was replaced with n-propyl alcohol in the modified Saltzman reagent; the spontaneous coloration and corrosive quality of the reagent was decreased by this substitution. The concentration of nitric oxide was obtained from the difference between the two responses of the analyzer, while the concentration of nitrogen dioxide could be read directly from the indication of the recorder. The transmittance ratio method was applied to the measurements, accurate determinations were possible, even at high blank values. Therefore, the reagent was used repeatedly by cycling it on the basis of measuring the difference in the coloration of the reagent before and after the absorption of nitrogen oxides. The analyzer could be used for a long period without changing the reagent.

  13. Nitrogen determination in pepper (Capsicum frutescens L.) plants by ...

    African Journals Online (AJOL)

    use

    2011-12-05

    Dec 5, 2011 ... significant negative relations between G/(R+G+B) ratio of coverage image and the indexes of pepper nitrogen status in this experiment. Hence, the suitable index of assessing pepper N status by color image analysis was discussed. MATERIALS AND METHODS. Experimental design. Experiment was made ...

  14. Development of a new microextraction method based on elevated temperature dispersive liquid-liquid microextraction for determination of triazole pesticides residues in honey by gas chromatography-nitrogen phosphorus detection.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Mogaddam, Mohammad Reza Afshar; Ghorbanpour, Houshang

    2014-06-20

    In the present study, a rapid, highly efficient, and reliable sample preparation method named "elevated temperature dispersive liquid-liquid microextraction" followed by gas chromatography-nitrogen-phosphorus detection was developed for the extraction, preconcentration, and determination of five triazole pesticides (penconazole, hexaconazole, diniconazole, tebuconazole, and difenoconazole) in honey samples. In this method the temperature of high-volume aqueous phase was adjusted at an elevated temperature and then a disperser solvent containing an extraction solvent was rapidly injected into the aqueous phase. After cooling to room temperature, the phase separation was accelerated by centrifugation. Various parameters affecting the extraction efficiency such as type and volume of the extraction and disperser solvents, temperature, salt addition, and pH were evaluated. Under the optimum extraction conditions, the method resulted in low limits of detection and quantification within the range 0.05-0.21ngg(-1) in honey (15-70ngL(-1) in solution) and 0.15-1.1ngg(-1) in honey (45-210ngL(-1) in solution), respectively. Enrichment factors and extraction recoveries were in the ranges of 1943-1994 and 97-100%, respectively. The method precision was evaluated at 1.5ngg(-1) of each analyte, and the relative standard deviations were found to be less than 4% for intra-day (n=6) and less than 6% for inter-days. The method was successfully applied to the analysis of honey samples and difenoconazole was determined at ngg(-1) levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Determination of isotopic identity of nitrogen fixed by Frankia associated with the genus Alnus

    International Nuclear Information System (INIS)

    Kurdali, F.; Domenach, A.M.; Daniere, C.; Bardin, R.

    1988-01-01

    To use the 15 N natural abundance method to evaluate the symbiotic nitrogen fixation by actinorhizal trees, it is necessary to determine the isotopic identity of assimilated nitrogen from two sources: the soil and the air. This study reports an isotopic value of fixed nitrogen by two alder species (Alnus Incana(L.) Moench and Alnus glutinosa(L.) Gaertn.) growing on nitrogen-free medium in greenhouse experiments. The δ 15 N value of the aerial parts was -2. This value was stable with time and did not depend on the Frankia strains used. This value could be used to estimate the nitrogen fixation in the natural ecosystem. Other parameters such as the mobilization of nitrogen reserves and the choice of the reference plant must be investigated to apply this method. The nodules of these two alder species were enriched in 15 N relative to the rest of the plant but there was no relationship between symbiotic effectiveness of Frankia strains and 15 N enrichment of nodules. On the other hand, for naturally growing trees, an enrichment in 15 N was found primarily in the vesicles of nodules that are the sites of nitrogen fixation. 37 refs., 4 figs., 3 tabs. (author)

  16. Glove box adaptation of oxygen, nitrogen and hydrogen determinator

    International Nuclear Information System (INIS)

    Ramanjaneyulu, P.S.; Phanindra Kumar, M.; Kulkarni, A.S.; Revathi, R.; Saxena, M.K.; Tomar, B.S.

    2017-01-01

    Radioanalytical Chemistry Division (RACD) is involved in chemical quality assurance (CQA) of various nuclear fuels and materials related to various DAE projects including FBTR and PFBR. Determination of oxygen, nitrogen and hydrogen in these fuels is one of the important steps in the CQA of material. For this purpose, O, N and H determinator was indigenously designed, fabricated and commissioned with the help of M/s Chromatography and Instruments Company Ltd., Vadodara, India. The present article describes about glove box adaptation of this instrument and various safety features incorporated in the glove box and instrument at Lab. C-25, RACD, as per the recommendations of the plant level safety committee

  17. Determination of daminozide residues in apples using gas chromatography with nitrogen-phosphorus detection

    NARCIS (Netherlands)

    Brinkman, J.H.W.; Dijk, A.G. van; Wagenaar, R.; Quirijns, J.K.

    1996-01-01

    A method was developed for the determination of daminozide in apples using gas chromatography (GC) with nitrogen-phosphorus detection (NPD). Daminozide is hydrolysed to 1,1-dimethylhydrazine (UDMH) by alkaline digestion. The UDMH generated is distilled from the apple matrix, derivatized with

  18. Synthesis of nitrogen-doped graphene via solid microwave method

    International Nuclear Information System (INIS)

    Zhang, Li; Ji, Bingcheng; Wang, Kai; Song, Jinyan

    2014-01-01

    Graphical abstract: - Highlights: • A direct solid microwave method is developed to prepare nitrogen-doped graphene. • The method consists of two steps, namely the functionalization and microwave irradiation. • Melamine can serve as not only functionalizing agent but also nitrogen source. - Abstract: In this paper, we propose a solid microwave-mediated method for scalable production of nitrogen-doped graphene sheets (NGS) using low-cost industrial material melamine as functionalizing agent and nitrogen source. The strong interaction of microwaves with graphene oxide has been fully utilized to generate in situ heating that induces the decompose melamine and nitrogen doping of graphene. The morphology, structure, and components of the as-produced nitrogen-doped graphene are characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET), pore-size distribution (PSD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The results show NGS can be successfully synthesized via this strategy

  19. Synthesis of nitrogen-doped graphene via solid microwave method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Li, E-mail: zhangli379@sohu.com [School of Electrical Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); Ji, Bingcheng, E-mail: debbo.jee@outlook.com [School of Electrical Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); Wang, Kai [School of Electrical Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); Song, Jinyan [School of Information Engineering, Dalian Ocean University, Dalian, Liaoning 116024 (China)

    2014-07-01

    Graphical abstract: - Highlights: • A direct solid microwave method is developed to prepare nitrogen-doped graphene. • The method consists of two steps, namely the functionalization and microwave irradiation. • Melamine can serve as not only functionalizing agent but also nitrogen source. - Abstract: In this paper, we propose a solid microwave-mediated method for scalable production of nitrogen-doped graphene sheets (NGS) using low-cost industrial material melamine as functionalizing agent and nitrogen source. The strong interaction of microwaves with graphene oxide has been fully utilized to generate in situ heating that induces the decompose melamine and nitrogen doping of graphene. The morphology, structure, and components of the as-produced nitrogen-doped graphene are characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET), pore-size distribution (PSD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectra (XPS), X-ray diffraction (XRD), and Raman spectroscopy. The results show NGS can be successfully synthesized via this strategy.

  20. Blank evaluation in nitrogen determination in seed grains by 14 MeV neutron activation analysis

    International Nuclear Information System (INIS)

    Wasek, M.; Sterlinski, S.

    1987-01-01

    In this work the term 'blank' signifies total radiation of the sample analyzed except that the element to be determined (analyte) is absent. On the basis of the evaluation of the blank components (nuclear and spectral interferences, air-nitrogen between grains, etc.), a semiempirical formula for calculating the nitrogen content in plant grain samples is proposed. The reliability of the results obtained with the use of this formula was demonstrated for five sorts of seeds (rye, wheat, barley, broad bean and soybean) which were analyzed by the Kjeldahl method and 14 MeV neutron activation analysis, respectively. (author)

  1. Effect of weed management methods and nitrogen fertilizer rates on ...

    African Journals Online (AJOL)

    Inefficient weed management practices and the use of inappropriate nitrogen fertilizer rates are the major causes of low yield of wheat in Ethiopia. Therefore, field experiments were conducted at Bobicho and Faate in southern Ethiopia to determine the effect of weed management practices and N fertilizer rates on grain yield ...

  2. Methods of affecting nitrogen assimilation in plants

    Energy Technology Data Exchange (ETDEWEB)

    Coruzzi, Gloria; Gutierrez, Rodrigo A.; Nero, Damion C.

    2016-10-11

    Provided herein are compositions and methods for producing transgenic plants. In specific embodiments, transgenic plants comprise a construct comprising a polynucleotide encoding CCA1, GLK1 or bZIP1, operably linked to a plant-specific promote, wherein the CCA1, GLK1 or bZIP1 is ectopically overexpressed in the transgenic plants, and wherein the promoter is optionally a constitutive or inducible promoter. In other embodiments, transgenic plants in which express a lower level of CCA1, GLK1 or bZIP1 are provided. Also provided herein are commercial products (e.g., pulp, paper, paper products, or lumber) derived from the transgenic plants (e.g., transgenic trees) produced using the methods provided herein.

  3. Cattle slurry on grassland - application methods and nitrogen use efficiency

    NARCIS (Netherlands)

    Lalor, S.T.J.

    2014-01-01

    Cattle slurry represents a significant resource on grassland-based farming systems. The objective of this thesis was to investigate and devise cattle slurry application methods and strategies that can be implemented on grassland farms to improve the efficiency with which nitrogen (N) in

  4. Nitrogen

    Science.gov (United States)

    Apodaca, Lori E.

    2013-01-01

    The article presents an overview of the nitrogen chemical market as of July 2013, including the production of ammonia compounds. Industrial uses for ammonia include fertilizers, explosives, and plastics. Other topics include industrial capacity of U.S. ammonia producers CF Industries Holdings Inc., Koch Nitrogen Co., PCS Nitrogen, Inc., and Agrium Inc., the impact of natural gas prices on the nitrogen industry, and demand for corn crops for ethanol production.

  5. Studies on the determination of trace amounts of nitrogen along with alkali and alkaline earth elements in uranium based samples by ion-chromatography (IC)

    International Nuclear Information System (INIS)

    Verma, Poonam; Rastogi, R.K.; Ramakumar, K.L.

    2006-12-01

    Present report describes an ion chromatography (IC) method with suppressed conductivity detection for the determination of traces of nitrogen along with alkali and alkaline earth elements in uranium based nuclear fuels. Method was developed to determine nitrogen as NH 4 + along with alkali and alkaline earth cations by IC using a cation exchange column. (author)

  6. Determination of nitrogen absorption and endogenous nitrogen secretion in the digestive tract of pigs fed with nitrogen-15-labelled dried whey

    International Nuclear Information System (INIS)

    Gebhardt, G.; Souffrant, W.; Koehler, R.; Zebrowska, T.

    1977-01-01

    Two fistulated pigs weighing between 15kg and 54kg were given experimental diets containing 15 N-labelled dried whey. The labelled experimental diets were given once only. Samples of the digesta were taken from the duodenum and terminal ileum at various intervals of time up to 48h after feeding the labelled protein feed. The digesta were separated into the four following fractions: Residue on centrifugation, proteins, peptides and free amino acids. The secretion of endogenous nitrogen in the duodenum was 12.5g/24h in pigs having a live weight of 50kg. The endogenous nitrogen was found to be relatively uniformly distributed among the four fractions. The rate of secretion of endogenous nitrogen showed a continuous decrease during 24h. The secretion of endogenous nitrogen in the terminal ileum was 54 to 60mg of nitrogen per kilogram live weight. After passage through the small intestine the greater part of the free amino acids in digesta was of exogenous origin. In the protein fraction most came from endogenous proteins. A true absorption of 17% of nitrogen was determined in the duodenum. The amount of nitrogen absorbed in the terminal part of the small intestine was, on average, 90% relative to the nitrogen intake. The true digestibility calculated with the amount of 15 N in food and faeces was 98%. (author)

  7. Determination of nitrogen in food stuffs using 14-MeV neutrons

    International Nuclear Information System (INIS)

    Shaddad, I.; Habbani, F.

    1994-03-01

    The neutron activation method was used for the determination of nitrogen in local food stuffs ( sorghum, grains, beans, nuts, wheat and sesame ). The 14 N(n,2n) 13 N reaction was used in this analysis. The protein content obtained ranged from 8% to 50%. The results of these measurements were compared with others obtained for the same samples using Kjeldahl chemical method. The comparison showed that the two measurements were in good agreement. An effort was also made to optimise the method with regard to sample irradiation and measurement acquisition times. (author). tabs

  8. DETERMINATION OF HEAT TRANSFER COEFFICIENTS FOR FRENCH PLASTIC SEMEN STRAW SUSPENDED IN STATIC NITROGEN VAPOR OVER LIQUID NITROGEN.

    Science.gov (United States)

    Santo, M V; Sansinena, M; Chirife, J; Zaritzky, N

    2015-01-01

    The use of mathematical models describing heat transfer during the freezing process is useful for the improvement of cryopreservation protocols. A widespread practice for cryopreservation of spermatozoa of domestic animal species consists of suspending plastic straws in nitrogen vapor before plunging into liquid nitrogen. Knowledge of surface heat transfer coefficient (h) is mandatory for computational modelling; however, h values for nitrogen vapor are not available. In the present study, surface heat transfer coefficients for plastic French straws immersed in nitrogen vapor over liquid nitrogen was determined; vertical and horizontal positions were considered. Heat transfer coefficients were determined from the measurement of time-temperature curves and from numerical solution of heat transfer partial differential equation under transient conditions using finite elements. The h values experimentally obtained for horizontal and vertically placed straws were compared to those calculated using correlations based on the Nusselt number for natural convection. For horizontal straws the average obtained value was h=12.5 ± 1.2 W m(2) K and in the case of vertical straws h=16 ± 2.48 W m(2) K. The numerical simulation validated against experimental measurements, combined with accurate h values provides a reliable tool for the prediction of freezing curves of semen-filled straws immersed in nitrogen vapor. The present study contributes to the understanding of the cryopreservation techniques for sperm freezing based on engineering concepts, improving the cooling protocols and the manipulation of the straws.

  9. Determination of the concentration dependent diffusion coefficient of nitrogen in expanded austenite

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2008-01-01

    The concentration dependent diffusion coefficient of nitrogen in expanded austenite was determined from of the rate of retracting nitrogen from thin initially N-saturated coupons. Nitrogen saturated homogeneous foils of expanded austenite were obtained by nitriding AISI 304 and AISI 316 in pure...... in the composition range where nitrogen can be extracted by hydrogen gas at the diffusion temperature. Numerical simulation of the denitriding experiments shows that the thus determined concentration dependent diffusion coefficients are an accurate approximation of the actual diffusivity of nitrogen in expanded...... ammonia at 693 K and 718 K. Denitriding experiments were performed by equilibrating the foils with a successively lower nitrogen activity, as imposed by a gas mixture of ammonia and hydrogen. The concentration dependent diffusion coefficient of nitrogen in expanded austenite was approximated...

  10. A sensitive spectrophotometric determination of nitrogen dioxide in the working atmosphere

    Directory of Open Access Journals (Sweden)

    Prachi Parmar

    2009-12-01

    Full Text Available In the present investigation, a simple and sensitive spectrophotometric method for the determination of nitrogen dioxide in various environmental samples is described. Nitrogen dioxide in air was fixed as nitrite ion in alkaline sodium arsenite absorbing solution. The nitrite formed was diazotized with p−aminoacetophenone in acidic medium which was subsequently coupled with phloroglucinol to give yellow−orange dye in alkaline medium having an absorption maximum at 420 nm. Beer’s law was obeyed in the range of 0.008 − 0.12 μg mL-1 of nitrogen dioxide and has a molar absorptivity of 2.875 x 105 L mol-1 cm-1. Optimum reaction conditions for diazotization, full colour development and the effect of variables like temperature, time and pH have been studied. Detailed studies to check the collection efficiency and NO2:NO2- stoichiometric ratio has been carried out. The reaction has been successfully applied for the detection of nitrogen dioxide in cigarette smoke, scooter exhaust, and workroom air.

  11. Method for optical 15N analysis of small amounts of nitrogen gas released from an automatic nitrogen analyzer

    International Nuclear Information System (INIS)

    Arima, Yasuhiro

    1981-01-01

    A method of optical 15 N analysis is proposed for application to small amounts of nitrogen gas released from an automatic nitrogen analyzer (model ANA-1300, Carlo Erba, Milano) subjected to certain set modifications. The ANA-1300 was combined with a vacuum line attached by a molecular sieve 13X column. The nitrogen gas released from the ANA-1300 was introduced with a carrier gas of helium into the molecular sieve column which was pre-evacuated at 10 -4 Torr and cooled with outer liquid nitrogen. After removal of the helium by evacuation, the nitrogen gas fixed on the molecular sieve was released by warming the column, and then, it was sealed into pre-evacuated pyrex glass tubes at 4.5 - 5.0 Torr. In the preparation of discharge tubes, contamination of unlabelled nitrogen occurred from the carrier gas of standard grade helium, and the relative lowering of the 15 N value by it was estimated to be less than 1% when over 700 μg nitrogen was charged on the ANA-1300; when 200 μg nitrogen was charged, it was about 3.5%. However, the effect of the contamination could be corrected for by knowing the amount of contaminant nitrogen. In the analysis of plant materials by the proposed method, the coefficient of variation was less than 2%, and no significant difference was observed between results given by the present method and by the ordinary method in which samples were directly pyrolyzed in the discharge tubes by the Dumas method. The present method revealed about 1.5 μg of cross-contaminated nitrogen and was applicable to more than 200 μg of sample nitrogen. (author)

  12. Immunological methods for gentamicin determination

    International Nuclear Information System (INIS)

    Krugers Dagneauz, P.G.L.C.; Olthuis, F.M.F.G.

    1979-01-01

    For immunoassay, an antibody against the substance to the determined, the pure substance itself, and a labelled form or derivative of the substance are required. The principles and problems of the preparation of antibodies are discussed, some methods for the preparation of derivatives labelled with radioactive tracers or enzymes are reviewed, and homologous enzyme-immunological determination of gentamicin is discussed in detail. A comparison is mae of three radio-immunological determination methods, and the most suitable radio-immunological method is compared with two microbiological techniques. The results are found to be comparable. (Auth.)

  13. Integrated method for the measurement of trace nitrogenous atmospheric bases

    Directory of Open Access Journals (Sweden)

    D. Key

    2011-12-01

    Full Text Available Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace, atmospheric, gaseous nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications (e.g., methylamine, 1 pptv; ethylamine, 2 pptv; morpholine, 1 pptv; aniline, 1 pptv; hydrazine, 0.1 pptv; methylhydrazine, 2 pptv, as supported by field measurements in an urban park and in the exhaust of on-road vehicles.

  14. Nitrogen removal from wastewater by a catalytic oxidation method.

    Science.gov (United States)

    Huang, T L; Macinnes, J M; Cliffe, K R

    2001-06-01

    The ammonia-containing waste produced in industries is usually characterized by high concentration and high temperature, and is not treatable by biological methods directly. In this study, a hydrophobic Pt/SDB catalyst was first used in a trickle-bed reactor to remove ammonia from wastewater. In the reactor, both stripping and catalytic oxidation occur simultaneously. It was found that higher temperature and higher oxygen partial pressure enhanced the ammonia removal. A reaction pathway, which involves oxidizing ammonia to nitric oxide, which then further reacts with ammonia to produce nitrogen and water, was confirmed. Small amounts of by-products, nitrites and nitrates were also detected in the resultant reaction solution. These compounds came from the absorption of nitrogen oxides. Both the minimum NO2- selectivity and maximum ammonia removal were achieved when the resultant pH of treated water was near 7.5 for a feed of unbuffered ammonia solution.

  15. A calorimetric method to determine water activity.

    Science.gov (United States)

    Björklund, Sebastian; Wadsö, Lars

    2011-11-01

    A calorimetric method to determine water activity covering the full range of the water activity scale is presented. A dry stream of nitrogen gas is passed either over the solution whose activity should be determined or left dry before it is saturated by bubbling through water in an isothermal calorimeter. The unknown activity is in principle determined by comparing the thermal power of vaporization related to the gas stream with unknown activity to that with zero activity. Except for three minor corrections (for pressure drop, non-perfect humidification, and evaporative cooling) the unknown water activity is calculated solely based on the water activity end-points zero and unity. Thus, there is no need for calibration with references with known water activities. The method has been evaluated at 30 °C by measuring the water activity of seven aqueous sodium chloride solutions ranging from 0.1 mol kg(-1) to 3 mol kg(-1) and seven saturated aqueous salt solutions (LiCl, MgCl(2), NaBr, NaCl, KCl, KNO(3), and K(2)SO(4)) with known water activities. The performance of the method was adequate over the complete water activity scale. At high water activities the performance was excellent, which is encouraging as many other methods used for water activity determination have limited performance at high water activities. © 2011 American Institute of Physics

  16. Selenium determination by fluorimetric method

    International Nuclear Information System (INIS)

    Lavorenti, A.

    1981-01-01

    A fluorimetric method to determine selenium both in vegetable samples and blood serum is developed. The method consists of a radioisotope 75 Se initially in order to optimize the determination of analytical conditions. Three samples digestion processes and also some factors related to methodology is studied. The nitric-percloric digestion process for 40 samples and the analytical process is shown. (M.J.C.) [pt

  17. Determination of biological nitrogen fixation capacities of winter and spring lentil varieties by using ''1''5N methodology

    International Nuclear Information System (INIS)

    Akin, A.

    2001-01-01

    In order to determine the biological nitrogen fixation capacities of winter and spring varieties of lentil which have of agronomic importance under the Central Anatolia region, the field experiments (winter and spring) were carried out. In both experiments, the effects of two different iconoclasts and different harvesting times on the biological nitrogen fixation capacities of lentil varieties, were investigated. The field experiments were conducted using by randomized block design as split-split plot for 4 replications. Barley was selected as the reference crop and 20 cm row spacing were used for lentil and barley. Inoculations were done immediately before sowing. 10.0 kg N/ ha for lentil varieties as 10.0 % ''1''5N atom excess and 40.0 kg N/ ha for barley (reference crop) as 2.0 % ''1''5N atom excess ammonium sulphate fertilizer were applied. In addition, 60.0 kgP 2 O 5 / ha were applied as triple superphosphate for all treatments. Plants were harvested at the different growth stages and than plant materials prepared for the analysis. Total nitrogen and % ''1''5N atom excess analysis were done by Kjeldahl method and Emission spectrometer, respectively. The amount of nitrogen fixation capacities of winter and spring lentil varieties were calculated according to the A-Value method (IAEA 1990). The results showed us that the winter varieties of lentil had higher dry matter yields and nitrogen fixation capacities than the spring varieties. Inoculation treatments had no statistically significant effects on the percentage of nitrogen derived from atmosphere (% Ndfa) and the amount of fixed nitrogen (kg N/ ha) for both experiments. In comparison between the harvesting times, the highest amount of fixed nitrogen was found at the pod formation stage for all cultivars. The average amounts of % Ndfa and fixed nitrogen (kg N/ ha) were 75.0 and 70.0 for winter cultivars, 70.0 and 45.0 for spring cultivars, respectively

  18. Evaluation of Image Processing Technique for Measuring of Nitrogen and Yield in Paddy Rice and Comparing it with Standard Methods

    Directory of Open Access Journals (Sweden)

    M.R Larijani

    2011-09-01

    Full Text Available In order to use new and low cost methods in precision agriculture, nitrogen should be supplied for plants on time and precisely. For determining the required nitrogen of paddy rice in the clustering stage, a series of experiments were conducted using three different methods of: image processing, kjeldahl and chlorophyll meter set (SPAD-502, in a randomized complete block design with three replications during 2010 at Rice Research Center of Tonekabon, Iran. Four experimental treatments were different level of fertilizer (Urea with 46% nitrogen. In the clustering stage, some images from rice plants were taken vertically by a digital camera and were analyzed using image processing technique. Simultaneously the chlorophyll index of plants was measured by SPAD-502 chlorophyll meter set and the percentage amount of nitrogen was measured using of the so called kjeldahl laboratory method. The results showed that the three methods of determining nitrogen of rice plant were highly correlated. Moreover, the correlation among the three methods and crop yield were almost the same. In general, the method of image processing could have a high potential for nitrogen management in the field, while this method was low-cost, faster and also nondestructive in comparison to the other methods.

  19. Feasibility study of using PET to determine nitrogen concentration after high energy photon irradiation

    International Nuclear Information System (INIS)

    Alghamdi, A.A.; Spyrou, N.M.; Al-Mokhlef, J.; Alhaj, A.

    2007-01-01

    The technique of photon activation analysis (PAA) is widely employed in many fields as an effective non-invasive tool for measuring elemental compositions and concentrations. In recent years there has been a revival and growing interest of PAA in general and for medical applications in particular. The feasibility of using a PET scanner (Ecat Exact 931) to determine nitrogen concentration in a dead rabbit is described. This method is based on the photon activation of 14 N(γ,n) 13 N (T 1/2 = 9.9 min) using an 18 MV photon beam Medical Linear Accelerator (Varian 2300EX). (author)

  20. Determining distances using asteroseismic methods

    DEFF Research Database (Denmark)

    Aguirre, Victor Silva; Casagrande, L.; Basu, Sarbina

    2013-01-01

    Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the r......Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification...... fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the {\\it Kepler} field that have accurate {\\it Hipparcos} parallaxes, we find agreement in our distance determinations to better than 5%. Comparison with measurements...

  1. Method of molybdenum kinetic determination

    International Nuclear Information System (INIS)

    Krejngol'd, S.U.; Dzotsenidze, N.E.; Ruseishviyai, T.G.; Nelen', I.M.

    1980-01-01

    The method molybdenum kinetic determination according to oxidation of pyrogallol with bromate in the medium of 0.05-0.15 M perchloric or sulphuric acids is presented. 1 mg of Ni, Co, Mn, Mg, Zn, Cr(3); 100 μg of Ca, Al, Cu, 10 μg of Cr(4), W; 10 μg of Fe in the presence of 22x10 - 4 M solution of EDTA, as well as 10 - 4 M solutions of chlorides and fluorides, 10 - 5 M solutions of bromides do not interfere with molybdenum determination using the given method. The method is rather simple, it takes 30 min to carry out the analysis. Determination limit of molybdenum constitutes 0.01 μg/ml

  2. Methods of clinical chemistry and isotopic technique for investigation of the nitrogen metabolism in man using 15N

    International Nuclear Information System (INIS)

    Faust, H.; Bornhak, H.; Hirschberg, K.; Jung, K.; Junghans, P.; Krumbiegel, P.; Reinhardt, R.

    1981-03-01

    The present manual is a catalogue of methods representing theoretical and practical aspects of application of the stable isotope 15 N in medicine as well as a reference book for users of 15 N techniques in life sciences. Special emphasis is given to the planning of 15 N tracer experiments and their interpretation, sources of error and standard values of nitrogen compounds, information on sampling of medical materials, methods of separation and determination of proteins and non-protein nitrogen compounds in serum and urine, and details of the isotopic analysis of nitrogen by emission and mass spectrometry. (author)

  3. Determination of ifosfamide, 2-and 3-dechloroethyifosfamide using gas chromatography with nitrogen-phosphorus or mass spectrometry detection

    NARCIS (Netherlands)

    Kerbusch, T; Jeuken, MJ; Derraz, J; van Putten, JWG; Huitema, ADR; Beijnen, JH

    2000-01-01

    A comparison was made between methods for determining ifosfamide (IF), 2- (2DCE) and 3-dechloroethylifosfamide (3DCE) using gas chromatography with nitrogen-phosphorus detection (GC-NPD) versus positive ion electron-impact ion-trap mass spectrometry (GC-MS'). Sample pretreatment involved

  4. Zeolite Soil Application Method Affects Inorganic Nitrogen, Moisture, and Corn Growth

    Science.gov (United States)

    Adoption of new management techniques which improve soil water storage and soil nitrogen plant availability yet limit nitrogen leaching may help improve environmental quality. A benchtop study was conducted to determine the influence of a single urea fertilizer rate (224 kilograms of Nitrogen per ...

  5. [Simultaneous determination of four common nonprotein nitrogen substances in urine by high performance liquid chromatography].

    Science.gov (United States)

    Ma, Yuhua; Huang, Dongqun; Zhang, Rui; Xu, Shiru; Feng, Shun

    2013-11-01

    A high performance liquid chromatographic (HPLC) method was proposed to simultaneously determine four common nonprotein nitrogen substances, including creatine (Cr), creatinine (Cn), uric acid (Ua) and pseudouridine (Pu) in urine. After proteins being removed by acetone precipitation method, freeze drying and redissolving, the urine samples were analyzed by HPLC. Chromatographic separation was performed on a Waters RP18 Column (150 mm x 4.60 mm, 3.5 microm) in gradient elution mode using 10.0 mmol/L KH2PO4 solution (pH 4.78) and acetonitrile as mobile phases at a flow rate of 0.8 mL/min. The samples were detected at 220 nm. Rapid separation was achieved within 7 min. Under the optimized conditions, good linearities of four common nonprotein nitrogen substances were obtained in the range of 0.1-250 mg/L. The detection limits were 9.31 (Cr), 26.19 (Cn), 4.70 (Ua), an 6.30 (Pu) microg/L and the recoveries were in the range of 81%-111% with the relative standar deviations of 0.23%-2.78% (n = 3). The results demonstrate that this method is simple, rapid and accurate with good reproducibility, and can provide early diagnosis and preliminary judgment for type 2 diabetes mellitus (T2DM) patients with renal damage.

  6. Semi-microdetermination of nitrogen in actinide compounds by Dumas method

    International Nuclear Information System (INIS)

    Nagar, M.S.; Ruikar, P.B.; Subramanian, M.S.

    1986-01-01

    This report describes the application of the Dumas method for the semi-micro determination of nitrogen in actinide compounds and actinide complexes with organic ligands. The usual set up has been modified to make it adaptable for glove box operations. The carbon dioxide generator and nitrometer assemblies were located outside the glove box while the reaction tube and combustion furnaces were housed inside. The nitrogen gas collected in the nitrometer was read with the help of a travelling microscope with a vernier attachment fitted in front of the nitrometer burette. The set up was standardised using acetanilide and employed for the determination of nirtogen in various substances such as uranium nitride, and a variety of substituted quinoline and pyrazolone derivatives of actinides as well as some ternary uranium-PMBR-sulphoxide complexes. Full details of the technique and the analytical data obtained are contained in this report. (author)

  7. Nitrogen

    Science.gov (United States)

    Apodaca, L.E.

    2010-01-01

    Ammonia was produced by 13 companies at 23 plants in 16 states during 2009. Sixty percent of all U.S. ammonia production capacity was centered in Louisiana. Oklahoma and Texas because of those states' large reserves of natural gas, the dominant domestic feedstock. In 2009, U.S. producers operated at about 83 percent of their rated capacity (excluding plants that were idle for the entire year). Five companies — Koch Nitrogen Co.; Terra Industries Inc.; CF Industries Inc.; PCS Nitrogen Inc. and Agrium Inc., in descending order — accounted for 80 percent of the total U.S. ammonia production capacity. U.S. production was estimated to be 7.7 Mt (8.5 million st) of nitrogen (N) content in 2009 compared with 7.85 Mt (8.65 million st) of N content in 2008. Apparent consumption was estimated to have decreased to 12.1 Mt (13.3 million st) of N, a 10-percent decrease from 2008. The United States was the world's fourth-ranked ammonia producer and consumer following China, India and Russia. Urea, ammonium nitrate, ammonium phosphates, nitric acid and ammonium sulfate were the major derivatives of ammonia in the United States, in descending order of importance.

  8. Method for determining the concentration of adsorbed protein and cell biomass in cellulose fermentations

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, A R; Phillips, J A; Humphrey, A E

    1978-09-01

    The method presented is based on the determination of the total Lowry protein of the solids and the total Kjeldahl nitrogen of the solids. Experimental data proving the validity of the method are reported. (JSR)

  9. Simulation methods of rocket fuel refrigerating with liquid nitrogen and intermediate heat carrier

    Directory of Open Access Journals (Sweden)

    O. E. Denisov

    2014-01-01

    Full Text Available Temperature preparation of liquid propellant components (LPC before fueling the tanks of rocket and space technology is the one of the operations performed by ground technological complexes on cosmodromes. Refrigeration of high-boiling LPC is needed to increase its density and to create cold reserve for compensation of heat flows existing during fueling and prelaunch operations of space rockets.The method and results of simulation of LPC refrigeration in the recuperative heat exchangers with heat carrier which is refrigerated by-turn with liquid nitrogen sparging. The refrigerating system consists of two tanks (for the chilled coolant and LPC, LPC and heat carrier circulation loops with heat exchanger and system of heat carrier refrigeration in its tank with bubbler. Application of intermediate heat carrier between LPC and liquid nitrogen allows to avoid LPC crystallization on cold surfaces of the heat exchanger.Simulation of such systems performance is necessary to determine its basic design and functional parameters ensuring effective refrigerating of liquid propellant components, time and the amount of liquid nitrogen spent on refrigeration operation. Creating a simulator is quite complicated because of the need to take into consideration many different heat exchange processes occurring in the system. Also, to determine the influence of various parameters on occurring processes it is necessary to take into consideration the dependence of all heat exchange parameters on each other: heat emission coefficients, heat transfer coefficients, heat flow amounts, etc.The paper offers an overview of 10 references to foreign and Russian publications on separate issues and processes occurring in liquids refrigerating, including LPC refrigeration with liquid nitrogen. Concluded the need to define the LPC refrigerating conditions to minimize cost of liquid nitrogen. The experimental data presented in these publications is conformed with the application of

  10. Determination of endogenous nitrogen in feces using 15N tracers

    International Nuclear Information System (INIS)

    Herrmann, U.; Krawielitzki, K.; Schadereit, R.; Smulikowska, S.

    1986-01-01

    A ration consisting of wheat gluten and N-free components was supplemented with L-lysine and L-leucine and fed to two groups of growing Wistar rats. Group 1 received 15 N Lys and unlabelled Leu, group 2 received unlabelled Lys and 15 N Leu in order to study the influence of the utilization of the 15 N marker on the labelling quota of feces and urine as well as various fractions of the body. The good utilization of Lys in group 1 results in a higher 15 N excess in feces and a reduced 15 N abundance in urine in comparison to group 2 with a lower utilization of 15 N Leu. The results show that the 15 N abundance in urine is unsuitable as an indicator of the 15 N labelling quota of endogenous metabolic fecal nitrogen. (author)

  11. Radiochemical method for determining treadwear

    International Nuclear Information System (INIS)

    Patel, A.C.

    1975-01-01

    A method for determining amount of treadwear of a tire is disclosed. The tire tread surface is impregnated with a radioactive material (iodine dissolved in toluene) and initial radioactivity measured at the tread surface. Subsequent measurements of radioactivity after wearing away tread indicate the amount of tread loss, when such measurements are compared with a calibration curve of radioactivity prepared for rubber of same composition and radioactive material of same concentration. Calibration curves are made by mechanically measuring loss of tread thickness of radioactive-impregnated rubber samples and measuring corresponding radioactivity remaining. (auth)

  12. Effect of different form of mineral nitrogen fertilizer and organic fertilization with compost on yield and quality of various field-grown vegetable crops (radish, carrot, spinach and tubers celery). Quality investigation through electrochemical method and the determination of p-value

    International Nuclear Information System (INIS)

    El-Sherbiny, M.

    1998-10-01

    This study was conducted to determine the effect of nitrogen form (calcium-nitrate, nitramoncal, ammonsulfate and urea) and the compost fertilization on yield and quality of different vegetable crops, which were grown under field condition at the same nitrogen fertilizer levels. In addition to evaluate the yield, the nitrate contents and p-value have been tested to determine the quality. Following results have been found: yield: the mineral nitrogen form had no significant effect on yield by radish, carrot, and celery. Spinach is positive responded by a different form of nitrogen fertilizer. The same yield results were nearly obtained by the use of compost, compared to another nitrogen fertilizer. Nitrate content: the nitrate content is investigated in edible plant parts. The nitrogen forms have been effected nitrate contents on researched vegetable crops. Generally, the minimum nitrate content is found in control variant and by use of compost, and too by ammonsulfate or urea fertilizer. The maximum nitrate content is reached by use of calcium-nitrate and nitramoncal fertilizer. Spinach leaves had less nitrate contents than stalks. P-value: results of examination shows a major relation between nitrogen fertilizer form and p-value. With the exception of carrot, had compost and control variants of radish, spinach and celery the highest significant p-value in comparison with another nitrogen fertilizer. The lowest p-value is obtained by application of calcium-nitrate and nitramoncal fertilizer, also for a better quality. (author)

  13. The effect of the rate and method of nitrogen application on nitrogen uptake and utilization by broccoli (Brassica oleracea var. italica)

    NARCIS (Netherlands)

    Everaarts, A.P.; Willigen, de P.

    1999-01-01

    The effect of the rate and method of nitrogen application on nitrogen uptake and utilization by broccoli (Brassica oleracea var. italica) was studied in four field experiments. The methods of application were broadcast application vs band placement and split application. Maximum uptake of nitrogen

  14. Contribution to the simultaneous determination of several light elements in alkalin metals by gamma photon and charged particle activation. Application to carbon and nitrogen determination in sodium

    International Nuclear Information System (INIS)

    Bock, Patrice.

    1976-10-01

    A new γ activation method for the simultaneous determination of carbon and nitrogen in sodium is described. It makes use of the nuclear reactions: 12 C(γ,n) 11 C and 14 N(γ,n) 13 N. The process used to separate carbone-11 and nitrogen-13 from sodium with a view to their radio-activity determination is based on vacuum dissolution of the sample in a mixture of oxidizing and acid fused salts. The oxidized carbon is trapped as CO 2 on soda asbestos and the nitrogen as N 2 on molecular sieve at -196 deg C. The efficiency of the technique is estimated by means of tracer tests and by proton activation. The relative influence of competitive nuclear reactions on elements close to the above two impurities, or even on the matrix itself, is examined. The method described has a theoretical detection limit of some 10 -8 g.g -1 for the two elements in question and mean concentrations of 0.3+-0.1x10 -6 g.g -1 carbon and 1.0+-0.5x10 -6 g.g -1 nitrogen have in fact been measured in a batch of 0.5 g sodium samples [fr

  15. Method for combined removal of mercury and nitrogen oxides from off-gas streams

    Science.gov (United States)

    Mendelsohn, Marshall H [Downers Grove, IL; Livengood, C David [Lockport, IL

    2006-10-10

    A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

  16. A comparison of three methods of Nitrogen analysis for feedstuffs

    African Journals Online (AJOL)

    Unknown

    Introduction. The Kjeldahl method for determining crude protein is very widely used for analysis of feed samples. However, it has its drawbacks and hence new techniques which are without some of the disadvantages are considered desirable. One such modification was developed by Hach et al. (1987). This promising ...

  17. Effects of nitrogen application method and weed control on corn yield and yield components.

    Science.gov (United States)

    Sepahvand, Pariya; Sajedi, Nurali; Mousavi, Seyed Karim; Ghiasvand, Mohsen

    2014-04-01

    The effects of nitrogen fertilizer application and different methods for weed control on yield and yield components of corn was evaluated in Khorramabad in 2011. The experiment was conducted as a split plot based on randomized complete block design in 3 replications. Nitrogen application was as main plot in 4 levels (no nitrogen, broadcasting nitrogen, banding nitrogen and sprayed nitrogen) and methods of weed control were in 4 levels (non-control weeds, application Equip herbicide, once hand control of weeds and application Equip herbicide+once time weeding) was as subplots. Result illustrated that effects of nitrogen fertilizer application were significant on grain and forage yield, 100 seeds weight, harvest index, grain number per row and cob weight per plant. Grain yield increased by 91.4 and 3.9% in application banding and broadcasting for nitrogen fertilizer, respectively, compared to the no fertilizer treatment. The results show improved efficiency of nitrogen utilization by banding application. Grain yield, harvest index, seed rows per cob, seeds per row and cob weight were increased by weed control. In the application of Equip herbicide+ hand weeding treatment corn grain yield was increased 126% in comparison to weedy control. It represents of the intense affects of weed competition with corn. The highest corn grain yield (6758 kg h(-1)) was related to the application banding of nitrogen fertilizer and Equip herbicide+once hand weeding.

  18. Determination of nitrogen in wheat flour through Activation analysis using Fast neutron flux of a Thermal nuclear reactor

    International Nuclear Information System (INIS)

    Ramirez G, T.

    1976-01-01

    In this work is done a technical study for determining Nitrogen (protein) and other elements in wheat flour Activation analysis, with Fast neutrons from a Thermal nuclear reactor. Initially it is given an introduction about the basic principles of the methods of analysis. Equipment used in Activation analysis and a brief description of the neutron source (Thermal nuclear reactor). The realized experiments for determining the flux form in the irradiation site, the half life of N-13 and the interferences due to the sample composition are included too. Finally, the obtained results by Activation and the Kjeldahl method are tabulated. (Author)

  19. Method for determining immunochemical substances

    International Nuclear Information System (INIS)

    O'connor, J.

    1980-01-01

    Drawing a method for detecting and measuring a predetermined specifically-bindable immunochemical substance in a liquid sample in a cuvette, comprising the steps of: (A) providing, in an immunoassay technique for the liquid sample in said cuvette, a component comprising a suspension of particles which may be agglutinated or insolubilized in relationship to the presence and concentration of the immunochemical substance in the sample; and (B) determining the presence and concentration of the immunochemical substance by measuring the electromagnetic radiation transmission properties of the sample using a calibrated radiation-measuring apparatus, said apparatus comprising: (1) a suitable electromagnetic radiation source capable of providing radiation at wavelengths equal to or less than the mean diameter of said particles; (2) means for concentrating and collimating radiation from the electromagnetic radiation source to form a beam; (3) means for filtering the beam to (I) eliminate radiation having wavelengths greater than the means diameter of the particles and (II) transmit radiation, which radiation has a range, whereby the upper wavelength is equal to or below the mean diameter of the particles, and the range is of at least about 100nm; (4) means for (I) positioning a sample-containing cuvette and for (II) allowing the filtered beam incident on the cuvette to be transmitted through the cuvette and sample, and for (III) receiving a portion of the filtered beam transmitted through the sample at two or more predetermined angles with respect to the beam; and (5) means for detecting and measuring the portion of the beam transmitted at a predetermined angle

  20. 14 MeV INAA nitrogen determination in coal conversion liquids

    International Nuclear Information System (INIS)

    Ehmann, W.D.; Khalil, S.R.

    1980-01-01

    Fast neutron activation analysis has been used for the direct determination of nitrogen in coal conversion liqui-ds. In our previous work on coals, solid standards such as N-1-napthylacetamide, NBS SRM 912 urea and NBS SRM 148 nicotinic acid were used for nitrogen determinations. In this work, a set of organic liquids was selected and evaluated for use as nitrogen standards in the analysis of coal-derived liquids. The use of the liquid standards minimizes problems associated with maintaining uniform irradation and counting geometries and self absorption differences related to varying matrix densities. The standard liquids were selected using criteria of high boiling point, well-defined stoichiometry, high-purity, non-hygroscopic nature and simple C-H-N elemental compositions. Excellent agreement between the 14 MeV INAA data and calculated stoichiometric values has been demonstrated for liquids with nitrogen contents from 1.89 to 39.95%. The liquid standards have been used to determine nitrogen in a set of typical coal conversion liquids and several international standards. (author)

  1. Determination of Optimum Nitrogen and Potassium Levels for potato Production in Central high lands of Ethiopia

    Directory of Open Access Journals (Sweden)

    Shunka Egata

    2017-02-01

    Full Text Available To determine the required levels of nitrogen and potassium, an experiment was conducted at Holetta Agricultural Research Center and Jeldu sub Center from 2014-2015 using three factors (Jalenie, Gudenie and Belete potato varies; 87, 110, 133kg/ha nitrogen rates and 0, 34.5, 69, 103.5kg/ha potassium in the form of K2O levels and as a completely randomized block design arrangement with three replications. In each location every year the 36 treatments (4 potassium oxide levels x 3 nitrogen levels x 3 varieties were assigned in random combinations to 36 plots of one block in a random case which was replicated in to two additional blocks of different randomizations in order to make total of three replications/blocks. Data were analyzed by SAS software Version 9.2. Potassium rates significantly affected the total yield and marketable yield as compared to the control treatment. Application of potassium at 103.5 kg/ha produced significantly a higher marketable yield than all rates. As compared to Jeldu, the Holetta location produced the maximum highly significant yield and yield component. Interaction of potassium and nitrogen fertilizers affected marketable tuber numbers and plant height significantly. In 2014, Belete produced the highest (27.31 ton/ha marketable yield at an application of 34.5 kg/ha potassium and 110 kg/ha nitrogen while Gudenie produced the highest (30.53 ton/ha marketable yield at an application of 69 kg/ ha potassium and 110 kg/ha nitrogen rates in 2015. It is better to apply 69 kg/ha potassium and 110 kg/ha nitrogen to potato production for reasonable yield at sites similar to experimental locations. It can be concluded that, interaction of nitrogen and potassium rates significantly affected plant height and marketable tuber numbers.

  2. Modern methods for radiostrontium determination

    International Nuclear Information System (INIS)

    Grahek, Z.; Kosutic, K.; Lulic, S.

    1998-01-01

    The basic principles of the ion exchange chromatographic determination of radioactive strontium in liquid wastes and natural samples are presented. The sample is inserted into the chromatographic column through the injection system connected to a pump. Strontium is separated by column elution. A flow scintillation beta detector is positioned at the column outlet. Prior to entering the column, strontium is mixed with a scintillator. The apparatus for semi-automatic radiostrontium determination is also described. (M.D.)

  3. Control of the nitrogen concentration in liquid lithium by the hot trap method

    International Nuclear Information System (INIS)

    Sakurai, Toshiharu; Yoneoka, Toshiaki; Tanaka, Satoru; Suzuki, Akihiro; Muroga, Takeo

    2002-01-01

    The nitrogen concentration in liquid lithium was controlled by the hot-trap method. Titanium, vanadium and a V-Ti alloy were used as nitrogen gettering materials. Gettering experiments were conducted at 673, 773 and 823 K for 0.4-2.8 Ms. After immersion, the nitrogen concentration increased in titanium and V-Ti were tested at 823 K. Especially the nitrogen gettering effect by the V-10at.%Ti alloy was found to be large. Nitrogen was considered to exist mainly as solid solution in the V-10at.%Ti alloy. The decrease of the nitrogen concentration in liquid lithium by the V-Ti gettering was also confirmed

  4. Effects of nitrogen rate and application method on early production and fruit quality in highbush blueberry

    Science.gov (United States)

    A field study was conducted to examine the effects of nitrogen (N) rate and method of N fertilizer application on growth, yield, and fruit quality in highbush blueberry (Vaccinium corymbosum L.) during the first 4 years after planting in south-coastal BC. Nitrogen was applied at 0-150% of current pr...

  5. Nitrogen cycling in a forest stream determined by a 15N tracer addition

    Science.gov (United States)

    Patrick J. Mullholland; Jennifer L. Tank; Diane M. Sanzone; Wilfred M. Wollheim; Bruce J. Peterson; Jackson R. Webster; Judy L. Meyer

    2000-01-01

    Nitrogen uptake and cycling was examined using a six-week tracer addition of 15N-labeled ammonium in early spring in Waer Branch, a first-order deciduous forest stream in eastern Tennessee. Prior to the 15N addition, standing stocks of N were determined for the major biomass compartments. During and after the addition,

  6. Methods for Quantitative Creatinine Determination.

    Science.gov (United States)

    Moore, John F; Sharer, J Daniel

    2017-04-06

    Reliable measurement of creatinine is necessary to assess kidney function, and also to quantitate drug levels and diagnostic compounds in urine samples. The most commonly used methods are based on the Jaffe principal of alkaline creatinine-picric acid complex color formation. However, other compounds commonly found in serum and urine may interfere with Jaffe creatinine measurements. Therefore, many laboratories have made modifications to the basic method to remove or account for these interfering substances. This appendix will summarize the basic Jaffe method, as well as a modified, automated version. Also described is a high performance liquid chromatography (HPLC) method that separates creatinine from contaminants prior to direct quantification by UV absorption. Lastly, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is described that uses stable isotope dilution to reliably quantify creatinine in any sample. This last approach has been recommended by experts in the field as a means to standardize all quantitative creatinine methods against an accepted reference. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  7. Nitrogen determination in wheat by neutron activation analysis using fast neutron flux from a thermal nuclear reactor

    International Nuclear Information System (INIS)

    Ramirez G, T.

    1976-01-01

    This is a study of the technique for the determination of nitrogen and other elements in wheat flour through activation analysis with fast neutrons from a thermal nuclear reactor. The study begins with an introduction about the basis of the analytical methods, the equipment used in activation analysis and a brief description of the neutrons source. In the study are included the experiments carried out in order to determine the flux form in the site of irradiation, the N-13 half life and the interference due to the sample composition. (author)

  8. Nitrogen-Doped Carbon Dots as A New Substrate for Sensitive Glucose Determination

    Directory of Open Access Journals (Sweden)

    Hanxu Ji

    2016-05-01

    Full Text Available Nitrogen-doped carbon dots are introduced as a novel substrate suitable for enzyme immobilization in electrochemical detection metods. Nitrogen-doped carbon dots are easily synthesised from polyacrylamide in just one step. With the help of the amino group on chitosan, glucose oxidase is immobilized on nitrogen-doped carbon dots-modified carbon glassy electrodes by amino-carboxyl reactions. The nitrogen-induced charge delocalization at nitrogen-doped carbon dots can enhance the electrocatalytic activity toward the reduction of O2. The specific amino-carboxyl reaction provides strong and stable immobilization of GOx on electrodes. The developed biosensor responds efficiently to the presence of glucose in serum samples over the concentration range from 1 to 12 mM with a detection limit of 0.25 mM. This novel biosensor has good reproducibility and stability, and is highly selective for glucose determination under physiological conditions. These results indicate that N-doped quantum dots represent a novel candidate material for the construction of electrochemical biosensors.

  9. Signatures of nitrogen stable isotope and determination of organic food authentication

    International Nuclear Information System (INIS)

    Yuan Yuwei; Zhang Zhiheng; Yang Guiling; Wang Qiang

    2009-01-01

    Chemical fertilizers were not permitted to be applied in organic agricultural production, so fertilizer as one of agricultural inputs is an important regulatory aspect in the organic food accreditation. Natural stable isotope abundances δ 15 N from different nitrogenous fertilizers are different, the same as in the agricultural products. Natural abundances δ 15 N in the agricultural products using organic fertilizer is higher than those in the products without using any fertilizer, while it is the lowest in the products using chemical nitrogenous fertilizer. Natural abundances δ 15 N are also affected by the ways of fertilizer treatment, the types of the crops and the growth stages as well as the different parts of crops. Generally, natural abundances of δ 15 N are preferred to trace nitrogenous fertilizer for the vegetables with shorter growing period, but not for the crops with longer growing period or nitrogen fixation. The techniques to trace the nitrogen abundances of δ 15 N in the crops play a positive role, which is useful for the determination of organic food authentication, perfecting the system of quality and supervision and protecting public health, therefore it has a theoretical and applied value. (authors)

  10. Predicting sulphur and nitrogen deposition using a simple statistical method

    Czech Academy of Sciences Publication Activity Database

    Oulehle, F.; Kopáček, Jiří; Chuman, T.; Černohous, V.; Hůnová, I.; Hruška, Jakub; Krám, Pavel; Lachmaová, Z.; Navrátil, Tomáš; Štěpánek, Petr; Tesař, Miroslav; Christopher, Evans D.

    2016-01-01

    Roč. 140, sep (2016), s. 456-468 ISSN 1352-2310 Grant - others:EHP(CZ) EHP-CZ02-OV-1-014-2014 Program:CZ02 Institutional support: RVO:67179843 ; RVO:60077344 ; RVO:67985831 ; RVO:67985874 Keywords : precipitation * sulphur * nitrogen * deposition * monitoring * upscaling Subject RIV: EH - Ecology, Behaviour; DD - Geochemistry (GLU-S); DI - Air Pollution ; Quality (BC-A); BK - Fluid Dynamics (UH-J) Impact factor: 3.629, year: 2016

  11. Method to reduce the nitrogen oxide content of gaseous wastes

    Energy Technology Data Exchange (ETDEWEB)

    Klopp, G.; Sueto, J.; Szasz, K.; Szebenyi, I.; Winkler, G.; Machacs, M.; Palmai, G.

    1980-11-13

    The proposed process is suited for the denitrification of waste gases from nitric acid plants. It proceeds without an additional energy source with an integrated adsorption unit which guaranties the complete recirculation of the produced nitrogen oxides and allows the regeneration of the adsorbents by the use of the energy from the oxidation of nitrous oxide to nitric oxide. The desorption is carried out by the intermediate passage of the hot gases from the oxidizer through the adsorber.

  12. Method of removing nitrogen monoxide from a nitrogen monoxide-containing gas using a water-soluble iron ion-dithiocarbamate, xanthate or thioxanthate

    Science.gov (United States)

    Liu, D. Kwok-Keung; Chang, Shih-Ger

    1987-08-25

    The present invention relates to a method of removing of nitrogen monoxide from a nitrogen monoxide-containing gas which method comprises contacting a nitrogen oxide-containing gas with an aqueous solution of water soluble organic compound-iron ion chelate complex. The NO absorption efficiency of ferrous urea-dithiocarbamate and ferrous diethanolamine-xanthate as a function of time, oxygen content and solution ph is presented. 3 figs., 1 tab.

  13. Simultaneous determination of boron, carbon and nitrogen in silicon by deuteron activation analysis

    International Nuclear Information System (INIS)

    He, Shiyu; Wang, Yinsong; Jin, Baikang; Hua, Zhifen; Zhao, Kaihua

    1984-01-01

    The paper describes simultaneous determination of trace quantities of B, C and N in semiconductor silicon by nuclear reaction of 10 B(d, n) 11 C(T 1/2 = 20.3 min), 11 B(d, 2n) 11 C, 12 C(d, n) 13 N(T 1/2 = 9.96 min) and 14 N(d, n) 15 O(T 1/2 = 2.03 min) with deuterons from a 1.2 m cyclotron in our institute. An inert-gas fusion technique is adopted for rapid radiochemical separation after irradiation of the samples. 11 C, 13 N and 15 O are absorbed in ascarite 5A molecular sieve cooled in liquid nitrogen and Hopcalite reagent at a temperature of 650 deg C respectively. Positron Annihilation events of each produced nucleus are counted by a γ - γ coincidence measuring system. B, C and N contents of about several ten parts per billion in silicon are then calculated simultaneously by a relatively quantitative method. Relative standard deviation for C, B and N are less than +-50% respectively. This method is simple, rapid and sensitive for estimating light element content in silicon material. (author)

  14. Review of methods for determination of ammonia volatilization in farmland

    Science.gov (United States)

    Yang, J.; Jiao, Y.; Yang, W. Z.; Gu, P.; Bai, S. G.; Liu, L. J.

    2018-02-01

    Ammonia is one of the most abundant alkaline trace gases in the atmosphere, which is one of the important factors affecting atmospheric quality. Excessive application of nitrogen fertilizer is the main source of global ammonia emissions, which not only exacerbate greenhouse gas emissions, but also leads to eutrophication of water bodies. In this paper, the basic principle, the operation process, the advantages and disadvantages, and the previous research results of the method are summarized in detail, including the enclosure method, the venting method, the continuous airflow enclosure method, the wind tunnel method and the micro-meteorological method. So as to provide a theoretical basis for selecting the appropriate method for determination of ammonia volatilization.

  15. Application of titration methods for measuring the contents of ammonium nitrogen and volatile fatty acids in agricultural biogas plants.

    Science.gov (United States)

    Piątek, Michał; Lisowski, Aleksander; Lisowska, Barbara

    2017-12-20

    The aim of our research was to assess a relatively new method of estimating ammonium nitrogen concentration in anaerobic digestion of plant substrates. We analysed our own data, received from the anaerobic digestion of maize silage (PM), as well as data published by Purser et al. (2014) who measured energy crops and slurry (ECS), and food waste (FW). In our study, the process was monitored for VFA content that was determined by gas chromatography, and for the content of ammonium nitrogen determined using the HACH LANGE LCK 303 cuvette test. We created polynomial regression models that bind the content of ammonium nitrogen with the volume of H 2 SO 4 used to titrate the sample from initial pH to pH 5. To estimate parameters of model, the PM dataset was used. The obtained models were positively validated using ECS and FW datasets. Our results confirmed the effectiveness of the Purser et al. method with an average absolute error of less than 223mgl -1 of the VFA concentration, which was approximately 20-times less than the level that caused inhibition. In conclusion, we can affirm the suitability of using titration methods to assess the ammonium nitrogen content of bioreactors with a stable composition. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. On nitrogen condensation in hypersonic nozzle flows: Numerical method and parametric study

    KAUST Repository

    Lin, Longyuan; Cheng, Wan; Luo, Xisheng; Qin, Fenghua

    2013-01-01

    A numerical method for calculating two-dimensional planar and axisymmetric hypersonic nozzle flows with nitrogen condensation is developed. The classical nucleation theory with an empirical correction function and the modified Gyarmathy model

  17. Evaluation of the recycle of nitrogen in a succession bean - corn -bean By means of the isotopic method

    International Nuclear Information System (INIS)

    Duennas Graciela; Munniz, Olegario; Sanchez, Tamara; Gomez, Luis

    1999-01-01

    To determine the recycle of Nitrogen in a succession bean - corn - bean a was developed I experience under field conditions, on Red Ferralitic soils (Rhodic Ferrasols) with the one I use of the stable isotope 15 Nitrogen

  18. Balance sheet method assessment for nitrogen fertilization in bread wheat: I. yield and quality

    Directory of Open Access Journals (Sweden)

    Maria Corbellini

    2006-09-01

    Full Text Available In the European Union the production of high quality wheat is mainly located in the Mediterranean regions where the climatic conditions positively affect protein concentration in the grain. High quality wheat calls for proper management of nitrogen fertilization, thus there is a need to verify whether the limitations imposed by local governments on maximum rate of nitrogen fertilization admitted may affect bread making quality. Trials were conducted in fourteen environments (E to study the effects of different nitrogen fertilizations on eight cultivars (C, belonging to four quality grades (Q. Nitrogen (N was applied to crops according to three rates/modalities: N1 corresponding to the maximum rate admitted calculated according to a balance sheet method and distributed at the stage of spike initiation; N2 with 50 kg ha-1 of nitrogen more than N1, also distributed at the stage of spike initiation; N3 with 50 kg ha-1 of nitrogen more than N1 but distributed at the stage of flag leaf appearance. The effects of environment, nitrogen and cultivar were significant for grain yield, test weight, 1000 kernel weight, heading time, plant height and for quality traits (protein content and alveograph indices. The existence of variability among cultivars and quality grades in the response to rate and timing of nitrogen fertilization was demonstrated by the significance of NxC and NxQ interactions. Dry matter and nitrogen contents of plant at anthesis and at harvest were significantly affected by the main sources of variation. High quality cultivars yielded more grain of better quality with higher N rates (N2 and N3 as compared to the maximum rate of nitrogen admitted by the local government (N1. These results demonstrated that the adopted balance sheet method for the calculation of N requirements of wheat crop adversely affects the full potential expression of the cultivars belonging to superior bread making quality grades.

  19. Balance sheet method assessment for nitrogen fertilization in bread wheat: I. yield and quality

    Directory of Open Access Journals (Sweden)

    Mario Monotti

    2011-02-01

    Full Text Available In the European Union the production of high quality wheat is mainly located in the Mediterranean regions where the climatic conditions positively affect protein concentration in the grain. High quality wheat calls for proper management of nitrogen fertilization, thus there is a need to verify whether the limitations imposed by local governments on maximum rate of nitrogen fertilization admitted may affect bread making quality. Trials were conducted in fourteen environments (E to study the effects of different nitrogen fertilizations on eight cultivars (C, belonging to four quality grades (Q. Nitrogen (N was applied to crops according to three rates/modalities: N1 corresponding to the maximum rate admitted calculated according to a balance sheet method and distributed at the stage of spike initiation; N2 with 50 kg ha-1 of nitrogen more than N1, also distributed at the stage of spike initiation; N3 with 50 kg ha-1 of nitrogen more than N1 but distributed at the stage of flag leaf appearance. The effects of environment, nitrogen and cultivar were significant for grain yield, test weight, 1000 kernel weight, heading time, plant height and for quality traits (protein content and alveograph indices. The existence of variability among cultivars and quality grades in the response to rate and timing of nitrogen fertilization was demonstrated by the significance of NxC and NxQ interactions. Dry matter and nitrogen contents of plant at anthesis and at harvest were significantly affected by the main sources of variation. High quality cultivars yielded more grain of better quality with higher N rates (N2 and N3 as compared to the maximum rate of nitrogen admitted by the local government (N1. These results demonstrated that the adopted balance sheet method for the calculation of N requirements of wheat crop adversely affects the full potential expression of the cultivars belonging to superior bread making quality grades.

  20. Determination of nitrogen reduction levels necessary to reach groundwater quality targets in Slovenia.

    Science.gov (United States)

    Andelov, Miso; Kunkel, Ralf; Uhan, Jože; Wendland, Frank

    2014-09-01

    Within a collaborative project between Slovenian Environment Agency (ARSO) and Research Center Jülich (FZJ), nitrogen reduction levels necessary to reach groundwater quality targets in Slovenia were assessed. For this purpose the hydrological model GROWA-DENUZ was coupled with agricultural N balances and applied consistently to the whole territory of Slovenia in a spatial resolution of 100×100m. GROWA was used to determine the water balance in Slovenia for the hydrologic period 1971-2000. Simultaneously, the displaceable N load in soil was assessed from agricultural Slovenian N surpluses for 2011 and the atmospheric N deposition. Subsequently, the DENUZ model was used to assess the nitrate degradation in soil and, in combination with the percolation water rates from the GROWA model, to determine nitrate concentration in the leachate. The areas showing predicted nitrate concentrations in the leachate above the EU groundwater quality standard of 50mg NO3(-)/L have been identified as priority areas for implementing nitrogen reduction measures. For these "hot spot" areas DENUZ was used in a backward mode to quantify the maximal permissible nitrogen surplus levels in agriculture to guarantee a nitrate concentration in percolation water below 50mg NO3(-)/L. Model results indicate that additional N reduction measures should be implemented in priority areas rather than area-covering. Research work will directly support the implementation of the European Union Water Framework Directive in Slovenia, e.g., by using the maximal permissible nitrogen surplus levels as a framework for the derivation of regionally adapted and hence effective nitrogen reduction measures. Copyright © 2014. Published by Elsevier B.V.

  1. Catalyst and method for reduction of nitrogen oxides

    Science.gov (United States)

    Ott, Kevin C [Los Alamos, NM

    2008-05-27

    A Selective Catalytic Reduction (SCR) catalyst was prepared by slurry coating ZSM-5 zeolite onto a cordierite monolith, then subliming an iron salt onto the zeolite, calcining the monolith, and then dipping the monolith either into an aqueous solution of manganese nitrate and cerium nitrate and then calcining, or by similar treatment with separate solutions of manganese nitrate and cerium nitrate. The supported catalyst containing iron, manganese, and cerium showed 80 percent conversion at 113 degrees Celsius of a feed gas containing nitrogen oxides having 4 parts NO to one part NO.sub.2, about one equivalent ammonia, and excess oxygen; conversion improved to 94 percent at 147 degrees Celsius. N.sub.2O was not detected (detection limit: 0.6 percent N.sub.2O).

  2. Spectrophotometric Methods for the Determination of Ketoconazole ...

    African Journals Online (AJOL)

    Spectrophotometric Methods for the Determination of Ketoconazole in Pharmaceutical Dosage Forms. ... Tropical Journal of Pharmaceutical Research ... Methods: The first method (A) was based on the oxidation of the studied drug by a known excess of cerium (IV) as an oxidizing agent and subsequent determination of ...

  3. Zirconium determination in refractories (gravimetric method)

    International Nuclear Information System (INIS)

    Capiotto, N.; Narahashi, Y.; Perish, C.G.; Souza, J.R.

    1991-01-01

    The zirconium determination in refractories is described, consisting in two separation methods for eliminating the interferences. The formatted product is calcined at 1100 0 C and determined gravimetrically as Zr P z 07. (author)

  4. Root distribution pattern and nitrogen uptake of some wheat and triticale germplasms in relation to rates and methods of nitrogen application

    International Nuclear Information System (INIS)

    Meena, N.L.; Seth, Jagdish

    1975-01-01

    A field experiment was conducted under irrigated conditions with four germplasms viz. Triticale(70-2), and wheat varieties HD 4502(durum), Kalyan Sona and Moti (aestivums) at the Indian Agricultural Research Institute Farm, New Delhi, during rabi season of 1972-73. The treatments comprised of three rates of nitrogen viz. 0,60 and 120 kg/ha and two methods of nitrogen application viz. (1) soil + foliar and (2) soil. The root distribution of the four germplasms, studied by 32 P injection technique was increased both vertically and horizontally with the addition of nitrogen. Root distribution of triticale was observed to be deep and spreading in habit, while durum proved to be shallow rooted and compact in nature. The total uptake of nitrogen was significantly increased with higher rates of nitrogen in all the germplasms. The maximum uptake of nitrogen was observed in the durum wheat. (author)

  5. Determination production costs using PBC method

    Directory of Open Access Journals (Sweden)

    Todić Vladimir V.

    2014-01-01

    Full Text Available Basic characteristics of modern markets make requirements in quality increasing, decreasing prices and shortening delivery of products. In the middle of this requirements are production costs for whose determination are developed many traditional and alternative methods including PBC method (Process Based Costing. This method enables precisely locating and calculating indirect production costs, and with determined direct costs enables determination of total production costs. This paper shows usage of PBC method for determination production costs for three forms of processing cutting tools.

  6. Isotopic-spectral determination of hydrogen, nitrogen, oxygen and carbon in semiconductor materials

    International Nuclear Information System (INIS)

    Dudich, G.K.; Eremeev, V.A.; Li, V.N.; Nemets, V.M.

    1981-01-01

    Techniques of low-temperature isotopic-spectral determination of impurities of hydrogen, nitrogen, oxygen and carbon in semiconductor materials Bi, Ge, Pb tellurides are developed. The techniques include selection into special vessel with the known volume (exchanger) of sample analyzed, dosed introduction into exchanger of rare isotope of the element determined ( 2 H, 15 N, 18 O, 13 C) in the form of isotope-containing gas, balancing of the determined element isotopes in the system sample-isotope, containing gas, spectroscopic, determination of its isotope composition in gaseous phase of the system and calculation of the amount of the element determined in the sample. The lower boundaries of the amounts determined constitute 10 -7 , 10 -7 , 10 -6 and 10 -5 mass % respectively when sample of 20 g are used [ru

  7. Nitrogen and water regime effects on corn yields determined by N-15 methodology

    International Nuclear Information System (INIS)

    Halitligil, M.B.; Akin, A.

    2002-01-01

    This investigation was carried out to determine the relationships between fertilizer N leaching and N fertilizer application time, method and irrigation rate by using 15 N methodology. Therefore, in the field experiments, the effects of three factors namely a) Irrigation rate (optimum 240 mm, high 360 mm), b) N application time (All at planting, 1/2 at planting and 1/2 after planting when plant heights were 50 cm), c) N application method (side dress and broadcast) were investigated. The field experiments were conducted using randomized block design as split-split plot and 4 replications. As the test plant hybrid corn was selected and at planting row spaces were arranged as 0.80 m x 0.25 m. Nitrogen was applied 120 kg N/ha to the all treatments as urea fertilizer (46 % N). In addition, to the sub-plots (which received half of N at planting and the other half when plant heights were 50 cm) 15 N labelled urea (2.63 % 15 N a.e. as 120 kg N/ha) was applied. After harvesting, total N and 15 N analyses were done for plant and soil samples. The results showed that the seed and total yields were increased with higher (360 mm) irrigation. When N application was side dressed the availability of N was increased, and also its loss by leaching from the active root zone was decreased. In conclusion, it was observed that at high irrigation rate was saved about 84 kg N/ha by side dressing rather than broadcasting of the applied N fertilizer

  8. Method of insulin determination by radioimmunoassay technique

    Energy Technology Data Exchange (ETDEWEB)

    Kokot, F; Kuska, J [Slaska Akademia Medyczna, Katowice (Poland)

    1973-01-01

    Technical details of a radioimmunological method of insulin determination in blood serum have been presented. Clinical value of the method was checked in 31 healthy subjects following oral or intravenous glucose administration, or after pancreatic islet stimulation using tolbutamide.

  9. STUDIES OF METHOD FOR DETERMINING THE PROTEIN CONCENTRATION OF "MALEIN PPD" BY THE KJELDAHL METHOD

    Directory of Open Access Journals (Sweden)

    Ciuca, V

    2017-06-01

    Full Text Available Glanders is a contagious and fatal disease of horses, donkeys, and mules, caused by infection with the bacterium Burkholderia mallei. The pathogen causes nodules and ulcerations in the upper respiratory tract and lungs. Glanders is transmissible to humans by direct contact with diseased animals or with infected or contaminated material. In the untreated acute disease, the mortality rate can reach 95% within 3 weeks Malein PPD - the diagnostic product contain max 2mg/ml Burkholderia mallei. The amount of protein in the biological product "Malein PPD" is measured as nitrogen from protein molecule, applying the Kjeldahl (method determination of nitrogen by sulphuric acid digestion. The validation study aims to demonstrate the determination of the protein of the Malein PPD, by sulphuric acid digestion, it is an appropriate analytical method, reproducible and meets the quality requirements of diagnostic reagents. The paper establishes the performance characteristics of the method considered and identify the factors that influence these characteristics. The method for determining the concentration of protein, by the Kjeldahl method is considered valid if the results obtained for each validation parameter are within the admissibility criteria.The validation procedure includes details on protocol working to determine the protein of the Malein PPD, validation criteria, experimental results, mathematical calculations.

  10. Organic carbon and nitrogen availability determine bacterial community composition in paddy fields of the Indo-Gangetic plain.

    Science.gov (United States)

    Kumar, Arvind; Rai, Lal Chand

    2017-07-01

    Soil quality is an important factor and maintained by inhabited microorganisms. Soil physicochemical characteristics determine indigenous microbial population and rice provides food security to major population of the world. Therefore, this study aimed to assess the impact of physicochemical variables on bacterial community composition and diversity in conventional paddy fields which could reflect a real picture of the bacterial communities operating in the paddy agro-ecosystem. To fulfill the objective; soil physicochemical characterization, bacterial community composition and diversity analysis was carried out using culture-independent PCR-DGGE method from twenty soils distributed across eight districts. Bacterial communities were grouped into three clusters based on UPGMA cluster analysis of DGGE banding pattern. The linkage of measured physicochemical variables with bacterial community composition was analyzed by canonical correspondence analysis (CCA). CCA ordination biplot results were similar to UPGMA cluster analysis. High levels of species-environment correlations (0.989 and 0.959) were observed and the largest proportion of species data variability was explained by total organic carbon (TOC), available nitrogen, total nitrogen and pH. Thus, results suggest that TOC and nitrogen are key regulators of bacterial community composition in the conventional paddy fields. Further, high diversity indices and evenness values demonstrated heterogeneity and co-abundance of the bacterial communities.

  11. Performance evaluation of nitrogen isotope ratio determination in marine and lacustrine sediments: An inter-laboratory comparison

    NARCIS (Netherlands)

    Bahlmann, E.; Bernasconi, S.M.; Bouillon, S.; Houtekamer, M.J.; Korntheuer, M.; Langenberg, F.; Mayr, C.; Metzke, M.; Middelburg, J.J.; Nagel, B.; Struck, U.; Voß, M.; Emeis, K.C.

    2010-01-01

    Nitrogen isotopes of organic matter are increasingly studied in marine biogeochemistry and geology, plant and animal ecology, and paleoceanography. Here, we present results of an inter-laboratory test on determination of nitrogen isotope ratios in marine and lacustrine sediments. Six different

  12. Determination of the ''1''4N to ''1''5N ratio in nitrogen-containing samples

    International Nuclear Information System (INIS)

    Aidarhanova, G.; Baktybaev, D.T.; Burtebaeva, N.; Burtebaev, N.; Djazairov-Kakhramanov, V.; Zazulin, D.M.; Urazaliev, R.U.; Ramazanova, S.B.; Baimaganova, G.Sh.; Ramazanova, R.H.

    2001-01-01

    It is known that nitrogen nutrition plays very important role in increase of plant crop and the albumin content in food rural cultures. Producers widely use nitrogen fertilizers. Their non-controlled or too extensive use can lead to contamination of air and water , resulting in hazardous sequences for human health and environment. The studies related to determination of nitrogen nutrition efficiency are based on utilization of the ''1''5N isotope, in view of determination of the best forms, time and place for introduction of nitrogen fertilizers, in order to provide the most reasonable nitrogen consumption by plants, avoiding waste and reducing the nitrogen fertilizer volumes required for obtaining a desired level of crop. In the course of natural experiments, scientists of various countries studied the processes of nitrogen consumption by plants from fertilizers, the processes responsible for nitrogen fixing in soil, nitrogen losses in a gaseous form or in liquids, in a form of solutions with ground water. The studies have shown that a fresh organic mass (manure) introduced to soil causes acceleration of decomposition of organic substance and renewal of the humus composition in soil. These phenomena can be detected by means of radioactive or stable isotopes

  13. Estimation of nitrogen fixation in Saccharum spp. by 15N dilution method

    International Nuclear Information System (INIS)

    Singh, Mohan

    1994-01-01

    The amount of nitrogen fixed by bacteria associated with the roots of Saccharum spontaneum, S. sinense, and S. barberi has been estimated by 15 N-isotope dilution method using Sclerotachya fusca as a non-fixing control. S. spontaneum produced highest shoot dry weight among the species tested but maximum nitrogen was accumulated by S. barberi. Highest dilution in the 15 N-enrichment was observed in S. spontaneum followed by S. sinense and S. barberi in comparison to the control plant of Sclerotchya fusca. S. spontaneum derived 60 per cent followed by S. sinense 54 per cent and S. barberi 35 per cent of their total nitrogen requirement through fixation of nitrogen by diazotrophic bacteria associated with their roots. (author). 11 refs., 2 tabs

  14. Methods of humidity determination Part II: Determination of material humidity

    OpenAIRE

    Rübner, Katrin; Balköse, Devrim; Robens, E.

    2008-01-01

    Part II covers the most common methods of measuring the humidity of solid material. State of water near solid surfaces, gravimetric measurement of material humidity, measurement of water sorption isotherms, chemical methods for determination of water content, measurement of material humidity via the gas phase, standardisation, cosmonautical observations are reviewed.

  15. Separation of ammonium and hydroxylamine nitrogen for the 15N determination

    International Nuclear Information System (INIS)

    Russow, R.

    1990-01-01

    After preseparation of the nitrogen compounds derived from microbial nitrification on a strong basic anion exchanger it is found hydroxylamine together with ammonium in one fraction. The nitrogen of this two compounds can be separated for the emission spectrometric 15 N analysis by the selective oxidation of the hydroxylamine to nitrite/nitrate using an iodine solution. Thus the hydroxylamine is protected against disproportionation during the following ammonium isolation by means of steam disillation in an alkaline medium. After that the nitrite/nitrate is reduced to ammonium using ferrous hydroxide and can than be librated by steam distillation. The performance of the method under discussion will be demonstrated by analysing solutions with known ammonium and hydroxylamine contents. (author)

  16. Determination of aluminum by four analytical methods

    International Nuclear Information System (INIS)

    Hanson, T.J.; Smetana, K.M.

    1975-11-01

    Four procedures have been developed for determining the aluminum concentration in basic matrices. Atomic Absorption Spectroscopy (AAS) was the routine method of analysis. Citrate was required to complex the aluminum and eliminate matrix effects. AAS was the least accurate of the four methods studied and was adversely affected by high aluminum concentrations. The Fluoride Electrode Method was the most accurate and precise of the four methods. A Gran's Plot determination was used to determine the end point and average standard recovery was 100% +- 2%. The Thermometric Titration Method was the fastest method for determining aluminum and could also determine hydroxide concentration at the same time. Standard recoveries were 100% +- 5%. The pH Electrode Method also measures aluminum and hydroxide content simultaneously, but is less accurate and more time consuming that the thermal titration. Samples were analyzed using all four methods and results were compared to determine the strengths and weaknesses of each. On the basis of these comparisons, conclusions were drawn concerning the application of each method to our laboratory needs

  17. Round Robin test for the determination of nitrogen concentration in solid Lithium

    International Nuclear Information System (INIS)

    Favuzza, P.; Antonelli, A.; Furukawa, T.; Groeschel, F.; Hedinger, R.; Higashi, T.; Hirakawa, Y.; Iijima, M.; Ito, Y.; Kanemura, T.; Knaster, J.; Kondo, H.; Miccichè, G.; Nitti, F.S.; Ohira, S.; Severi, M.; Sugimoto, M.; Suzuki, A.; Traversi, R.; Wakai, E.

    2016-01-01

    Highlights: • Nitrogen contained in solid Lithium is converted into Ammonium ion. • Ammonium ion is suitably quantified by ionic chromatograph or by Ammonia sensor. • Good agreement of the partner’s results has been achieved. • Maximum operative reproducibility and blank subtraction are necessary. - Abstract: Three different partners, ENEA, JAEA ed University of Tokyo, have been involved during 2014–2015 in the Round Robin experimentation for the assessment of the soundness of the analitycal procedure for the determination of the Nitrogen impurities contained inside a solid Lithium sample. Two different kinds of Lithium samples, differing by about an order of magnitude in Nitrogen concentration (∼230 wppm; ∼20–30 wppm), have been selected for this cross analysis. The agreement of the achieved results appears very good for what concerns the most concentrated Lithium and indicates each partner’s procedure is appropriate and intrinsecally able to lead to meaningful values, characterized by a relative uncertainty of just few %. The smaller agreement in the case of the less concentrated Lithium anyway points out that particular attention must be paid to reduce as much as possible any source of external contamination and highlights the importance of the proper blank subtraction.

  18. Round Robin test for the determination of nitrogen concentration in solid Lithium

    Energy Technology Data Exchange (ETDEWEB)

    Favuzza, P., E-mail: paolo.favuzza@enea.it [ENEA Center, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Antonelli, A. [ENEA Research Center, Brasimone, 40035, Camugnano (Italy); Furukawa, T. [JAEA Research Center, Tokai-mura, Ibaraki (Japan); Groeschel, F. [KIT Research Center, Hermann-von-Helmholtz-Platz 1,76344 Eggenstein-Leopoldshafen (Germany); Hedinger, R. [F4E Research Center, Boltzmannstraße 2, 85748 Garching (Germany); Higashi, T. [University of Tokyo (Japan); Hirakawa, Y.; Iijima, M.; Ito, Y.; Kanemura, T. [JAEA Research Center, Tokai-mura, Ibaraki (Japan); Knaster, J. [IFMIF-EVEDA Project Team, Rokkasho (Japan); Kondo, H. [JAEA Research Center, Tokai-mura, Ibaraki (Japan); Miccichè, G.; Nitti, F.S. [ENEA Research Center, Brasimone, 40035, Camugnano (Italy); Ohira, S. [JAEA Research Center, Tokai-mura, Ibaraki (Japan); Severi, M. [University of Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); Sugimoto, M. [JAEA Research Center, Rokkasho (Japan); Suzuki, A. [University of Tokyo (Japan); Traversi, R. [University of Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (Italy); Wakai, E. [JAEA Research Center, Tokai-mura, Ibaraki (Japan)

    2016-06-15

    Highlights: • Nitrogen contained in solid Lithium is converted into Ammonium ion. • Ammonium ion is suitably quantified by ionic chromatograph or by Ammonia sensor. • Good agreement of the partner’s results has been achieved. • Maximum operative reproducibility and blank subtraction are necessary. - Abstract: Three different partners, ENEA, JAEA ed University of Tokyo, have been involved during 2014–2015 in the Round Robin experimentation for the assessment of the soundness of the analitycal procedure for the determination of the Nitrogen impurities contained inside a solid Lithium sample. Two different kinds of Lithium samples, differing by about an order of magnitude in Nitrogen concentration (∼230 wppm; ∼20–30 wppm), have been selected for this cross analysis. The agreement of the achieved results appears very good for what concerns the most concentrated Lithium and indicates each partner’s procedure is appropriate and intrinsecally able to lead to meaningful values, characterized by a relative uncertainty of just few %. The smaller agreement in the case of the less concentrated Lithium anyway points out that particular attention must be paid to reduce as much as possible any source of external contamination and highlights the importance of the proper blank subtraction.

  19. Determination of internal controls for quantitative gene expression of Isochrysis zhangjiangensis at nitrogen stress condition

    Science.gov (United States)

    Wu, Shuang; Zhou, Jiannan; Cao, Xupeng; Xue, Song

    2016-02-01

    Isochrysis zhangjiangensis is a potential marine microalga for biodiesel production, which accumulates lipid under nitrogen limitation conditions, but the mechanism on molecular level is veiled. Quantitative real-time polymerase chain reaction (qPCR) provides the possibility to investigate the gene expression levels, and a valid reference for data normalization is an essential prerequisite for firing up the analysis. In this study, five housekeeping genes, actin (ACT), α-tubulin (TUA), ß-tubulin (TUB), ubiquitin (UBI), 18S rRNA (18S) and one target gene, diacylglycerol acyltransferase (DGAT), were used for determining the reference. By analyzing the stabilities based on calculation of the stability index and on operating the two types of software, geNorm and bestkeeper, it showed that the reference genes widely used in higher plant and microalgae, such as UBI, TUA and 18S, were not the most stable ones in nitrogen-stressed I. zhangjiangensis, and thus are not suitable for exploring the mRNA expression levels under these experimental conditions. Our results show that ACT together with TUB is the most feasible internal control for investigating gene expression under nitrogen-stressed conditions. Our findings will contribute not only to future qPCR studies of I. zhangjiangensis, but also to verification of comparative transcriptomics studies of the microalgae under similar conditions.

  20. Effects of drying method, storage period and carbon: nitrogen ratio ...

    African Journals Online (AJOL)

    Taghwo

    2012-12-03

    Dec 3, 2012 ... African Journal of Environmental Science and Technology Vol. 6(12), pp. .... Drying method 2 (method 2) involved air drying field- fresh soil ... then packed in polyethylene bags and stored at -10°C until inorganic N extraction ...

  1. Determination of U by the Mallinckrodt method

    International Nuclear Information System (INIS)

    Chaussabel, L.

    The Mallinckrodt method enables to determine U concentrations within 0.2% relative accuracy in various products: uranyl nitrates, magnesium uranates, sintered oxides, and uranium concentrates. The method was improved by the automatic spectrophotometric detection of the titration. The device used is a Sarjent apparatus equipped with a 525 nm filter. The method is described in details [fr

  2. Non liquid nitrogen-based-method for isolation of DNA from ...

    African Journals Online (AJOL)

    A simple, efficient, reliable and cost-effective method for isolation of total genomic DNA from fungi, suitable for polymerase chain reaction (PCR) amplification and other molecular applications was described. The main advantages of the method are: (1) does not require the use of liquid nitrogen for preparation of fungi DNA; ...

  3. Genetics parameters and association of NUE methods in maize under different nitrogen levels

    Directory of Open Access Journals (Sweden)

    Edmar Vinícius de Carvalho

    2016-03-01

    Full Text Available This work aimed to study the association of four nitrogen use efficiency (NUE methods and the genetic parameters of grain weight in two groups of maize genotypes, under different levels of nitrogen supply, in the season 2012/13. 16 field experiments were carried out in the city of Gurupi, Tocantins, Brazil. Each genotype group was evaluated in different seeding date, and each one was tested with different levels of nitrogen supply. In all experiments the experimental design was completely randomized blocks with three repetitions. The following trait was evaluated after stage R6: grain yield (GY, and after, four indices of efficiency/stress to nitrogen were estimated. The Pearson correlation coefficients, estimated among the indices, were all significant (P < 0.01. Among the seeding dates, the average heritability of GY was 54.4% and among the levels of nitrogen supply, the following values were observed: 60.4% (low N; 50.9% (medium N; 51.2% (high N. There is the possibility of the use of environments with lower nitrogen supply in the search for superior and more efficient genotypes for the GY, and based on our results, the Low N index is more adequate.

  4. Assessing total nitrogen in surface-water samples--precision and bias of analytical and computational methods

    Science.gov (United States)

    Rus, David L.; Patton, Charles J.; Mueller, David K.; Crawford, Charles G.

    2013-01-01

    The characterization of total-nitrogen (TN) concentrations is an important component of many surface-water-quality programs. However, three widely used methods for the determination of total nitrogen—(1) derived from the alkaline-persulfate digestion of whole-water samples (TN-A); (2) calculated as the sum of total Kjeldahl nitrogen and dissolved nitrate plus nitrite (TN-K); and (3) calculated as the sum of dissolved nitrogen and particulate nitrogen (TN-C)—all include inherent limitations. A digestion process is intended to convert multiple species of nitrogen that are present in the sample into one measureable species, but this process may introduce bias. TN-A results can be negatively biased in the presence of suspended sediment, and TN-K data can be positively biased in the presence of elevated nitrate because some nitrate is reduced to ammonia and is therefore counted twice in the computation of total nitrogen. Furthermore, TN-C may not be subject to bias but is comparatively imprecise. In this study, the effects of suspended-sediment and nitrate concentrations on the performance of these TN methods were assessed using synthetic samples developed in a laboratory as well as a series of stream samples. A 2007 laboratory experiment measured TN-A and TN-K in nutrient-fortified solutions that had been mixed with varying amounts of sediment-reference materials. This experiment identified a connection between suspended sediment and negative bias in TN-A and detected positive bias in TN-K in the presence of elevated nitrate. A 2009–10 synoptic-field study used samples from 77 stream-sampling sites to confirm that these biases were present in the field samples and evaluated the precision and bias of TN methods. The precision of TN-C and TN-K depended on the precision and relative amounts of the TN-component species used in their respective TN computations. Particulate nitrogen had an average variability (as determined by the relative standard deviation) of 13

  5. Phosphorus determination by various substoichiometric methods

    International Nuclear Information System (INIS)

    Shigematsu, Toshio; Kudo, Kiyoshi

    1981-01-01

    Various substoichiometric methods have been classified from a view point of the substoichiometric separation. Based upon the substoichiometric separation, phosphorus was determined substoichiometrically by a direct method, a method of carrier amount variation and a comparison method for the irradiated sample. The direct method was applied to the determination of phosphorus in orchard leaves (SRM-1571). The analytical value was 0.23 +- 0.01%. Phosphorus in orchard leaves and spinach (SRM-1570) was determined by an ordinary method which devided the sample into equal parts in the method of carrier amount variation. Analytical values of orchard leaves and spinach were 0.22 +- 0.02% and 0.56 +- 0.04%, respectively. Moreover, a new modification of the method of carrier amount variation was studied by the use of various standard samples such as red phosphorus, spinach and orchard leaves. These standard samples were also employed for the determination of phosphorus in orchard leaves and 0.21 +- 0.01% was obtained. All these results are in good agreement with the value reported by NBS. The comparison method was applied to the determination of phosphorus in a semiconductor silicon single crystal. As a result of the correction of 32 P activity induced by the secondary nuclear reaction of 30 Si, 7.9 ppb and 3.1 ppb were obtained for the phosphorus concentrations in the single crystal silicon. (author)

  6. Determining water and nitrogen balances for beneficial management practices using lysimeters at Wagna test site (Austria).

    Science.gov (United States)

    Klammler, Gernot; Fank, Johann

    2014-11-15

    The shallow Murtal aquifer south of Graz, Austria, provides easily withdrawable groundwater, which is supplied as drinking water without any chemical treatment. The aquifer is also used intensively by agriculture. Common agricultural management practices are the main source for diffuse nitrogen leaching and high groundwater nitrate concentrations. To safeguard the coexisting use of these two important resources, lysimeters are operated at the agricultural test site Wagna, Austria, and the influence of two beneficial management practices--low nitrogen input and organic farming--on nitrogen leaching towards groundwater is investigated. The technical lysimeter design as presented here consists of: (1) high-resolution weighing cells, (2) a suction controlled lower boundary condition for sucking off seepage water, thus emulating undisturbed field conditions, (3) comparative soil temperature, water content and matrix potential measurements inside and outside the lysimeter at different depths, (4) an installation of the lysimeters directly into test plots and (5) a removable upper lysimeter ring enabling machinery soil tillage. Our results indicate that oasis effects or fringe effects of the lysimeter cylinder on unsaturated water flow did not occur. Another lysimeter cultivated with lawn is operated for observing grass-reference evapotranspiration, which resulted in good agreement with calculated grass-reference evapotranspiration according to the FAO-Penman-Monteith method. We conclude that lysimeters installed at Wagna test site did not show any fringe effects and, thus, are appropriate tools for measuring water balance elements and nitrogen leaching of arable and grass land at point scale. Furthermore, our results for the period of 2005 to 2011 show that beneficial management practices reduced nitrate leaching and, hence, may allow for a sustainable coexistence of drinking water supply and agriculture in the Murtal aquifer. Copyright © 2014 Elsevier B.V. All rights

  7. Combination of inoculation methods of Azospirilum brasilense with broadcasting of nitrogen fertilizer increases corn yield

    Directory of Open Access Journals (Sweden)

    Tânia Maria Müller

    2015-01-01

    Full Text Available Nitrogen (N is the most limiting nutrient for corn production. Thereby, the goal of the paper was to evaluate inoculation methods of Azospirillum brasilense in order to partially supply N required by the crop. The experiment was carried out in Guarapuava, PR, Brasil, in 2011/2012 growing season. Randomized blocks with factorial 3 inoculation methods (seed treatment, planting furrow and non-inoculated control x 5 doses of nitrogen (0, 75, 150, 225 and 300kg ha-1 x 8 replications was used as the experimental design. Leaf are index, foliar nitrogen content, total chlorophyll, grains per ear and yield were evaluated. There was significant interaction between inoculation methods and nitrogen fertilization to leaf area index, but not for yield. Inoculation with the diazotrophic bacteria provided yield increase of 702kg ha-1 for inoculation in seeding furrow and 432kg ha-1 for inoculation in seed treatment compared to the control, but both treatments did not differ between each other. Furthermore, total chlorophyll, grains per ear and yield were positively affected, with quadratic response, by the nitrogen fertilization in broadcasting

  8. On nitrogen condensation in hypersonic nozzle flows: Numerical method and parametric study

    KAUST Repository

    Lin, Longyuan

    2013-12-17

    A numerical method for calculating two-dimensional planar and axisymmetric hypersonic nozzle flows with nitrogen condensation is developed. The classical nucleation theory with an empirical correction function and the modified Gyarmathy model are used to describe the nucleation rate and the droplet growth, respectively. The conservation of the liquid phase is described by a finite number of moments of the size distribution function. The moment equations are then combined with the Euler equations and are solved by the finite-volume method. The numerical method is first validated by comparing its prediction with experimental results from the literature. The effects of nitrogen condensation on hypersonic nozzle flows are then numerically examined. The parameters at the nozzle exit under the conditions of condensation and no-condensation are evaluated. For the condensation case, the static pressure, the static temperature, and the amount of condensed fluid at the nozzle exit decrease with the increase of the total temperature. Compared with the no-condensation case, both the static pressure and temperature at the nozzle exit increase, and the Mach number decreases due to the nitrogen condensation. It is also indicated that preheating the nitrogen gas is necessary to avoid the nitrogen condensation even for a hypersonic nozzle with a Mach number of 5 operating at room temperatures. © 2013 Springer-Verlag Berlin Heidelberg.

  9. Locations of oxygen, nitrogen and carbon atoms in vanadium determined by neutron diffraction

    International Nuclear Information System (INIS)

    Hiraga, K.; Onozuka, T.; Hirabayashi, M.

    1977-01-01

    The occupation sites of oxygen, nitrogen, and carbon atoms dissolved interstitially in vanadium have been determined by means of neutron diffraction with use of single crystals of VOsub(0.032), VNsub(0.013) and VCsub(0.006). It is revealed that the interstitial atoms occupy, randomly, the octahedral sites in the b.c.c. host lattice of the three crystals. Neutron diffraction is advantageous for the present purpose, since the coherent scattering amplitudes of the solute atoms are much larger than that of the vanadium atom. (Auth.)

  10. The role of char and tar in determining the gas-phase partitioning of nitrogen during biomass gasification

    International Nuclear Information System (INIS)

    Broer, Karl M.; Brown, Robert C.

    2015-01-01

    Highlights: • Switchgrass was gasified at an equivalence ratio of zero and 650–850 °C. • Short residence times were employed to minimize secondary reactions. • Char- and tar-bound nitrogen, NH_3, HCN, and N_2 were all significant products. • Increasing temperature leads to increased release of gaseous nitrogen compounds. • Kinetic models of gasification should include nitrogen release from char and tar. - Abstract: Gasification is an attractive option for converting biomass into fuels and chemicals. Most biomass contains significant amounts of fuel-bound nitrogen (FBN), which partially converts into ammonia (NH_3) and hydrogen cyanide (HCN) during gasification. These nitrogen compounds are problematic as they can lead to NO_X emissions or catalyst poisoning in downstream applications of syngas. FBN can convert to other products as well, including diatomic nitrogen (N_2), char-bound nitrogen (char-N), and tar-bound nitrogen (tar-N). Efforts to predict concentrations of NH_3 and HCN have been hindered by a lack of accurate, comprehensive measurements of nitrogen partitioning among gasification products. The present study gasified switchgrass under allothermal, short residence time conditions and measured NH_3, HCN, char-N, and tar-N as a function of temperature in the range of 650–850 °C with diatomic nitrogen determined by difference. It was found that a major portion of FBN was retained in the char and tar products. As temperature was increased, char and tar were consumed, releasing nitrogen as gaseous NH_3 and HCN. This increase in undesirable nitrogen compounds is contrary to the predictions of most gasification models, which overlook the presence of significant nitrogen in char and tar even if they include tar cracking and char gasification reactions. The results of this study demonstrate that gas-phase reactions alone are not sufficient to predict the fate of nitrogen during gasification. In order for modeling efforts to obtain more accurate

  11. Calculation methods for determining dose equivalent

    International Nuclear Information System (INIS)

    Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

    1987-11-01

    A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. Critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 [1] methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed. The effective dose equivalent determined using ICRP-26 methods is significantly smaller than the dose equivalent determined by traditional methods. No existing personnel dosimeter or health physics instrument can determine effective dose equivalent. At the present time, the conversion of dosimeter response to dose equivalent is based on calculations for maximal or ''cap'' values using homogeneous spherical or cylindrical phantoms. The evaluated dose equivalent is, therefore, a poor approximation of the effective dose equivalent as defined by ICRP Publication 26. 3 refs., 2 figs., 1 tab

  12. Synthesis of a novel nitrogen-doped carbon dot by microwave-assisted carbonization method and its applications as selective probes for optical pH (acidity) sensing in aqueous/nonaqueous media, determination of nitrate/nitrite, and optical recognition of NO{sub X} gas

    Energy Technology Data Exchange (ETDEWEB)

    Doroodmand, Mohammad Mahdi, E-mail: doroodmand@shirazu.ac.ir; Askari, Mohsen

    2017-05-22

    A novel nitrogen-doped carbon dot (N-CD) was synthesized via carbonization of citric acid in the presence of triethylenetetramine as a nitrogen source. The average size of the N-doped CDs and also the quantum yield of the synthesized N-doped CDs were both estimated to be 9 ± 2 nm and 39.5%, respectively. The applications of the synthesized carbon nanostructure as a high quantum yield fluorescence probe were initially adopted in the fabrication of a novel optical pH (acidity) sensor in both aqueous and nonaqueous environments. Two optimum dynamic intervals were obtained with the ranges of1.5–5.0 and 7.0–10.0. for the fabricated pH sensor with a standard deviation of 0.09 pH (n = 4). The quantity of HClO{sub 4} inside acetic acid was determined as the degree of acidity with a linear range between 1.0 and 4.0%. Determination of nitrate (NO{sub 3}{sup −}) and nitrite (NO{sub 2}{sup −}) based on the fluorescence quenching of N-CDs was also evaluated in detail. The linear ranges for NO{sub 2}{sup −} and NO{sub 3}{sup −} species were estimated to be from 1 × 10{sup −7}to 7.5 × 10{sup −5} and from 2.5 × 10{sup −6} to 7.5 × 10{sup −4} mol L{sup −1}, respectively with RSD of 3.69% (n = 5) for NO{sub 2}{sup −} and 3.54% (n = 5) for NO{sub 3}{sup −}. The LODs (X+3S{sub b}) for both NO{sub 2}{sup −} and NO{sub 3}{sup −} were estimated to be 2.5 × 10{sup −8} and 7.5 × 10{sup −7} mol L{sup −1}, respectively. The synthesized N-CDs were also applicable for NO{sub X} recognition in the gaseous form at part per thousand (ppt) levels with linear ranges of 3.77–36.51 and 27.67–43.77 ppt, LOD (X+3S{sub b}) of 1.41 ppt (n = 4) and RSD of 4.37% (n = 5). The reliability of these methods was also evaluated via the analyses of different forms of gaseous, water and rumen samples. - Highlights: • N-dots as Fluorescent Probe. • N-dots Synthesized by Microwave-Assisted Carbonization. • Determination of Nitrate

  13. Zirconium determination in refractories (gravimetric method)

    International Nuclear Information System (INIS)

    Capiotto, N.; Narahashi, Y.; Perish, P.G.; Souza, J.R. de

    1991-01-01

    A gravimetric method for zirconium determination in refractories is described. X-ray fluorescence analysis is also employed in this experiment and considerations about interfering elements are presented. (M.V.M.)

  14. Rapid synthesis of nitrogen doped titania with mixed crystal lattice via microwave-assisted hydrothermal method

    International Nuclear Information System (INIS)

    Zhang Peilin; Liu Bin; Yin Shu; Wang Yuhua; Petrykin, Valery; Kakihana, Masato; Sato, Tsugio

    2009-01-01

    A microwave-assisted hydrothermal method was employed to synthesize nitrogen doped titania nanoparticles. Due to the high heating efficiency of microwave, rapid synthesis could be achieved in comparison with the conventional oven. Mixed crystal lattice was found existing in the obtained product, and the phase transformation behaviour under calcination was studied by XRD measurement together with Raman spectroscopy in details. The obtained nitrogen doped titania showed high specific surface area, about 300 m 2 g -1 . Photocatalytic activity in destructing NO x gas by the prepared sample exceeded that of commercial titania (P 25) or nitrogen doped titania synthesized by conventional hydrothermal method, under both visible-light and ultraviolet-light irradiation.

  15. Growth versus metabolic tissue replacement in mouse tissues determined by stable carbon and nitrogen isotope analysis

    Science.gov (United States)

    Macavoy, S. E.; Jamil, T.; Macko, S. A.; Arneson, L. S.

    2003-12-01

    Stable isotope analysis is becoming an extensively used tool in animal ecology. The isotopes most commonly used for analysis in terrestrial systems are those of carbon and nitrogen, due to differential carbon fractionation in C3 and C4 plants, and the approximately 3‰ enrichment in 15N per trophic level. Although isotope signatures in animal tissues presumably reflect the local food web, analysis is often complicated by differential nutrient routing and fractionation by tissues, and by the possibility that large organisms are not in isotopic equilibrium with the foods available in their immediate environment. Additionally, the rate at which organisms incorporate the isotope signature of a food through both growth and metabolic tissue replacement is largely unknown. In this study we have assessed the rate of carbon and nitrogen isotopic turnover in liver, muscle and blood in mice following a diet change. By determining growth rates, we were able to determine the proportion of tissue turnover caused by growth versus that caused by metabolic tissue replacement. Growth was found to account for approximately 10% of observed tissue turnover in sexually mature mice (Mus musculus). Blood carbon was found to have the shortest half-life (16.9 days), followed by muscle (24.7 days). Liver carbon turnover was not as well described by the exponential decay equations as other tissues. However, substantial liver carbon turnover was observed by the 28th day after diet switch. Surprisingly, these tissues primarily reflect the carbon signature of the protein, rather than carbohydrate, source in their diet. The nitrogen signature in all tissues was enriched by 3 - 5‰ over their dietary protein source, depending on tissue type, and the isotopic turnover rates were comparable to those observed in carbon.

  16. Nitrogen turnover of three different agricultural soils determined by 15N triple labelling

    Science.gov (United States)

    Fiedler, Sebastian R.; Kleineidam, Kristina; Strasilla, Nicol; Schlüter, Steffen; Reent Köster, Jan; Well, Reinhard; Müller, Christoph; Wrage-Mönnig, Nicole

    2017-04-01

    To meet the demand for data to improve existing N turnover models and to evaluate the effect of different soil physical properties on gross nitrogen (N) transformation rates, we investigated two arable soils and a grassland soil after addition of ammonium nitrate (NH4NO3), where either ammonium (NH4+), or nitrate (NO3-), or both pools have been labelled with 15N at 60 atom% excess (triple 15N tracing method). Besides NH4+, NO3- and nitrite (NO2-) contents with their respective 15N enrichment, nitrous oxide (N2O) and dinitrogen (N2) fluxes have been determined. Each soil was adjusted to 60 % of maximum water holding capacity and pre-incubated at 20˚ C for two weeks. After application of the differently labelled N fertilizer, the soils were further incubated at 20˚ C under aerobic conditions in a He-N2-O2 atmosphere (21 % O2, 76 He, 2% N2) to increase the sensitivity of N2 rates via the 15N gas flux method. Over a 2 week period soil N pools were quantified by 2 M KCl extraction (adjusted to pH 7 to prevent nitrite losses) (Stevens and Laughlin, 1995) and N gas fluxes were measured by gas chromatography in combination with IRMS. Here, we present the pool sizes and fluxes as well as the 15N enrichments during the study. Results are discussed in light of the soil differences that were responsible for the difference in gross N dynamics quantified by the 15N tracing model Ntrace (Müller et al., 2007). References Müller, C., T. Rütting, J. Kattge, R.J. Laughlin, and R.J. Stevens, (2007) Estimation of parameters in complex 15N tracing models by Monte Carlo sampling. Soil Biology & Biochemistry. 39(3): p. 715-726. Stevens, R.J. and R.J. Laughlin, (1995) Nitrite transformations during soil extraction with potassium chloride. Soil Science Society of America Journal. 59(3): p. 933-938.

  17. DATING: A computer code for determining allowable temperatures for dry storage of spent fuel in inert and nitrogen gases

    International Nuclear Information System (INIS)

    Simonen, E.P.; Gilbert, E.R.

    1988-12-01

    The DATING (Determining Allowable Temperatures in Inert and Nitrogen Gases) code can be used to calculate allowable initial temperatures for dry storage of light-water-reactor spent fuel. The calculations are based on the life fraction rule using both measured data and mechanistic equations as reported by Chin et al. (1986). The code is written in FORTRAN and utilizes an efficient numerical integration method for rapid calculations on IBM-compatible personal computers. This report documents the technical basis for the DATING calculations, describes the computational method and code statements, and includes a user's guide with examples. The software for the DATING code is available through the National Energy Software Center operated by Argonne National Laboratory, Argonne, Illinois 60439. 5 refs., 8 figs., 5 tabs

  18. [Radiocompetitive method of H antigen determination].

    Science.gov (United States)

    Semenova, G B; Sokolov, Ia A; Liashenko, V A

    1978-06-01

    The authors describe a radiocompetitive method of H-d-monomere determination with the sensitivity of 2 ng/ml in double antibodies modification; this method was used for comparing the immunological affinity of the affiliated H-antigens. A difference between the immunological affinity to the antibodies in a monomere, polymere and the flagellum was shown.

  19. Methods of determining information needs for control

    Energy Technology Data Exchange (ETDEWEB)

    Borkowski, Z.

    1980-01-01

    Work has begun in the Main Data Center in the field of mining (Poland) on estimation in improvement of methods of determining information requirements necessary for control. Existing methods are briefly surveyed. Their imperfection is shown. The complexity of characteristics for this problem is pointed out.

  20. A Simple and Rapid Method to Evaluate Potentially Mineralizable Nitrogen in Sewage Sludge Amended Calcareous Soils

    Directory of Open Access Journals (Sweden)

    Yazdan Lotfi

    2005-06-01

    Full Text Available Potentially mineralizable nitrogen (PMN can be usually considered as labile nitrogen. Measurement of PMN is expensive and time consuming; therefore, a simpler and more rapid alternative may facilitate routine laboratory analysis. The objective of this study was to determine the relationship between PMN and biological index of nitrogen availability (BINA. The studied soil was previously treated with 0, 25, and 100 tons ha-1 of sewage sludge with 0, 1, 2 and 3 consecutive years of application. Soil samples were taken 6 months after the latest application. PMN was measured according to Stanford and Smith procedure (20 weeks of aerobic incubation with 2 weeks leaching intervals and BINA measured as described by Bundy and Meisinger (7 days of anaerobic incubation at 40˚ C followed by extraction of NH4+. Results showed that PMN was significantly correlated with BINA (r = 0.938, P

  1. Methods for determination of extractable complex composition

    International Nuclear Information System (INIS)

    Sergievskij, V.V.

    1984-01-01

    Specific features and restrictions of main methods for determining the extractable complex composition by the distribution data (methods of equilibrium shift, saturation, mathematical models) are considered. Special attention is given to the solution of inverse problems with account for hydration effect on the activity of organic phase components. By example of the systems lithium halides-isoamyl alcohol, thorium nitrate-n-hexyl alcohol, mineral acids tri-n-butyl phosphate (TBP), metal nitrates (uranium lanthanides) - TBP the results on determining stoichiometry of extraction equilibria obtained by various methods are compared

  2. Method for the production of nitrogen and hydrogen in a fuel cell

    NARCIS (Netherlands)

    Hemmes, K.

    2007-01-01

    The invention relates to a method for the production of nitrogen and hydrogen in a fuel cell with an anode and a cathode, comprising the steps of inducing a combustion in a fuel cell, wherein a fuel is supplied to the anode, and air is supplied to the cathode, and with oxygen in the air being

  3. Flow analysis methods for the direct ultra-violet spectrophotometric measurement of nitrate and total nitrogen in freshwaters

    Energy Technology Data Exchange (ETDEWEB)

    Gentle, Brady S.; Ellis, Peter S.; Grace, Michael R. [Water Studies Centre, School of Chemistry, Monash University, Victoria 3800 (Australia); McKelvie, Ian D., E-mail: iandm@unimelb.edu.au [School of Chemistry, University of Melbourne, Victoria 3010 (Australia); School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2011-10-17

    Highlights: {yields} Second derivative UV spectrophotometry has been used to determine nitrate and total N using flow analysis techniques. {yields} A simple flow system with a single-reflection flow-through cell was used for the UV measurement of nitrate. {yields} Total N was determined after on-line UV photooxidation with alkaline peroxodisulfate. {yields} Analyses carried out using the developed flow systems show a high degree of agreement with comparative analyses. {yields} This method requires no colorimetric reagents and eliminates the requirement for a toxic cadmium reduction column. - Abstract: Second derivative ultra-violet spectrophotometric methods are described for the measurement of nitrate and total nitrogen in freshwaters using flow analysis techniques. A simple flow system consisting of a peristaltic pump and a single-reflection flow-through cell was used for the measurement of nitrate. Quantification of total nitrogen using alkaline peroxodisulfate photo-digestion was achieved by incorporating an ultra-violet photo-reactor, a hollow-fibre filter and a debubbler into the flow system. The nitrate system featured a limit of detection of 0.04 mg N L{sup -1}, 0.4%RSD (1 mg N L{sup -1} as nitrate, n = 10), a coefficient of determination (R{sup 2}) of 0.9995 over the calibration range 0.0-2.0 mg N L{sup -1}, and a data acquisition time of 1.5 s per spectrum. The total nitrogen system featured a limit of detection of 0.05 mg N L{sup -1}, 1%RSD (1 mg N L{sup -1} as ammonium chloride, n = 10), a coefficient of determination of 0.9989 over the calibration range 0.0-2.0 mg N L{sup -1}, and a throughput of 5 sample h{sup -1} measured in triplicate. Digestions of five model nitrogen compounds returned recoveries of >88%. Determinations carried out using the developed systems show a high degree of agreement with data obtained using reference methods. These methods require no colorimetric reagents and eliminate the requirement for a toxic cadmium reduction column

  4. Flow analysis methods for the direct ultra-violet spectrophotometric measurement of nitrate and total nitrogen in freshwaters

    International Nuclear Information System (INIS)

    Gentle, Brady S.; Ellis, Peter S.; Grace, Michael R.; McKelvie, Ian D.

    2011-01-01

    Highlights: → Second derivative UV spectrophotometry has been used to determine nitrate and total N using flow analysis techniques. → A simple flow system with a single-reflection flow-through cell was used for the UV measurement of nitrate. → Total N was determined after on-line UV photooxidation with alkaline peroxodisulfate. → Analyses carried out using the developed flow systems show a high degree of agreement with comparative analyses. → This method requires no colorimetric reagents and eliminates the requirement for a toxic cadmium reduction column. - Abstract: Second derivative ultra-violet spectrophotometric methods are described for the measurement of nitrate and total nitrogen in freshwaters using flow analysis techniques. A simple flow system consisting of a peristaltic pump and a single-reflection flow-through cell was used for the measurement of nitrate. Quantification of total nitrogen using alkaline peroxodisulfate photo-digestion was achieved by incorporating an ultra-violet photo-reactor, a hollow-fibre filter and a debubbler into the flow system. The nitrate system featured a limit of detection of 0.04 mg N L -1 , 0.4%RSD (1 mg N L -1 as nitrate, n = 10), a coefficient of determination (R 2 ) of 0.9995 over the calibration range 0.0-2.0 mg N L -1 , and a data acquisition time of 1.5 s per spectrum. The total nitrogen system featured a limit of detection of 0.05 mg N L -1 , 1%RSD (1 mg N L -1 as ammonium chloride, n = 10), a coefficient of determination of 0.9989 over the calibration range 0.0-2.0 mg N L -1 , and a throughput of 5 sample h -1 measured in triplicate. Digestions of five model nitrogen compounds returned recoveries of >88%. Determinations carried out using the developed systems show a high degree of agreement with data obtained using reference methods. These methods require no colorimetric reagents and eliminate the requirement for a toxic cadmium reduction column. The overlap of chloride and nitrate spectra in seawater is

  5. Species ecology determines the role of nitrogen nutrition in the frost tolerance of pine seedlings.

    Science.gov (United States)

    Toca, Andrei; Oliet, Juan A; Villar-Salvador, Pedro; Maroto, Judit; Jacobs, Douglass F

    2018-01-01

    Frost determines the evolution and distribution of plants in temperate and cold regions. Several environmental factors can influence frost acclimation of woody plants but the magnitude and direction of the effect of nitrogen (N) availability is controversial. We studied the effect of N availability on root and shoot frost tolerance in mid-fall and in winter in seedlings of four pines of contrasting ecology: Pinus nigra J.F. Arnold, P. pinaster Ait., P. pinea L. and P. halepensis Mill.. Organ N and soluble sugar concentration, and timing of cessation of shoot elongation were measured to assess the physiological mechanisms underlying frost acclimation. Nitrogen was supplied at high and low rates only during the pre-hardening period and at a moderate N rate during hardening in the fall. Shoot frost tolerance increased over winter while root frost tolerance did not change in any species. Pre-hardening N availability affected the frost tolerance of both roots and shoots, although the effect was species-specific: high N reduced the overall root and shoot frost tolerance in P. pinea and P. halepensis, and increased the frost tolerance in P. nigra, but had no effect in P. pinaster. Nitrogen supply in the fall consistently increased frost tolerance in all species. Differences in frost tolerance among species and N treatments were not explained by variations in organ N or soluble carbohydrate concentration, nor by timing of cessation of shoot elongation; however, the most frost tolerant species ceased elongation earlier than the least frost tolerant species. Despite the close phylogenetic relatedness of the studied species, the effect of N availability on seedling frost tolerance differed among species, indicating that species ecology (especially frost acclimation physiology) and timing of N supply drives the effect of N availability on frost tolerance of pine species. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please

  6. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

    Science.gov (United States)

    Walker, Richard J.

    1986-01-01

    A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

  7. Determination of heat transfer coefficients in plastic French straws plunged in liquid nitrogen.

    Science.gov (United States)

    Santos, M Victoria; Sansinena, M; Chirife, J; Zaritzky, N

    2014-12-01

    The knowledge of the thermodynamic process during the cooling of reproductive biological systems is important to assess and optimize the cryopreservation procedures. The time-temperature curve of a sample immersed in liquid nitrogen enables the calculation of cooling rates and helps to determine whether it is vitrified or undergoes phase change transition. When dealing with cryogenic liquids, the temperature difference between the solid and the sample is high enough to cause boiling of the liquid, and the sample can undergo different regimes such as film and/or nucleate pool boiling. In the present work, the surface heat transfer coefficients (h) for plastic French straws plunged in liquid nitrogen were determined using the measurement of time-temperature curves. When straws filled with ice were used the cooling curve showed an abrupt slope change which was attributed to the transition of film into nucleate pool boiling regime. The h value that fitted each stage of the cooling process was calculated using a numerical finite element program that solves the heat transfer partial differential equation under transient conditions. In the cooling process corresponding to film boiling regime, the h that best fitted experimental results was h=148.12±5.4 W/m(2) K and for nucleate-boiling h=1355±51 W/m(2) K. These values were further validated by predicting the time-temperature curve for French straws filled with a biological fluid system (bovine semen-extender) which undergoes freezing. Good agreement was obtained between the experimental and predicted temperature profiles, further confirming the accuracy of the h values previously determined for the ice-filled straw. These coefficients were corroborated using literature correlations. The determination of the boiling regimes that govern the cooling process when plunging straws in liquid nitrogen constitutes an important issue when trying to optimize cryopreservation procedures. Furthermore, this information can lead to

  8. Methods for determination of biomethane potential of feedstocks: a review

    Directory of Open Access Journals (Sweden)

    Raphael Muzondiwa Jingura

    2017-06-01

    Full Text Available Biogas produced during anaerobic digestion (AD of biodegradable organic materials. AD is a series of biochemical reactions in which microorganisms degrade organic matter under anaerobic conditions. There are many biomass resources that can be degraded by AD to produce biogas. Biogas consists of methane, carbon dioxide, and trace amounts of other gases. The gamut of feedstocks used in AD includes animal manure, municipal solid waste, sewage sludge, and various crops. Several factors affect the potential of feedstocks for biomethane production. The factors include nutrient content, total and volatile solids (VS content, chemical and biological oxygen demand, carbon/nitrogen ratio, and presence of inhibitory substances. The biochemical methane potential (BMP, often defined as the maximum volume of methane produced per g of VS substrate provides an indication of the biodegradability of a substrate and its potential to produce methane via AD. The BMP test is a method of establishing a baseline for performance of AD. BMP data are useful for designing AD parameters in order to optimise methane production. Several methods which include experimental and theoretical methods can be used to determine BMP. The objective of this paper is to review several methods with a special focus on their advantages and disadvantages. The review shows that experimental methods, mainly the BMP test are widely used. The BMP test is credited for its reliability and validity. There are variants of BMP assays as well. Theoretical models are alternative methods to estimate BMP. They are credited for being fast and easy to use. Spectroscopy has emerged as a new experimental tool to determine BMP. Each method has its own advantages and disadvantages with reference to efficacy, time, and ease of use. Choosing a method to use depends on various exigencies. More work needs to be continuously done in order to improve the various methods used to determine BMP.

  9. Calculation methods for determining dose equivalent

    International Nuclear Information System (INIS)

    Endres, G.W.R.; Tanner, J.E.; Scherpelz, R.I.; Hadlock, D.E.

    1988-01-01

    A series of calculations of neutron fluence as a function of energy in an anthropomorphic phantom was performed to develop a system for determining effective dose equivalent for external radiation sources. critical organ dose equivalents are calculated and effective dose equivalents are determined using ICRP-26 methods. Quality factors based on both present definitions and ICRP-40 definitions are used in the analysis. The results of these calculations are presented and discussed

  10. Substrates and method for determining enzymes

    Science.gov (United States)

    Smith, R.E.; Bissell, E.R.

    1981-10-13

    A method is disclosed for determining the presence of an enzyme in a biological fluid, which includes the steps of contacting the fluid with a synthetic chromogenic substrate, which is an amino acid derivative of 7-amino-4-trifluoromethylcoumarin; incubating the substrate-containing fluid to effect enzymatic hydrolysis; and fluorometrically determining the presence of the free 7-amino-4-trifluoromethylcoumarin chromophore in the hydrolyzate. No Drawings

  11. Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.

    Science.gov (United States)

    Grunert, Oliver; Reheul, Dirk; Van Labeke, Marie-Christine; Perneel, Maaike; Hernandez-Sanabria, Emma; Vlaeminck, Siegfried E; Boon, Nico

    2016-05-01

    Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint. We investigated if fertilizer type and medium constituents determine microbial nitrogen conversions in organic growing media and can be used as a next step towards a more sustainable horticulture. We demonstrated that growing media constituents showed differences in urea hydrolysis, ammonia and nitrite oxidation and in carbon dioxide respiration rate. Interestingly, mixing of the growing media constituents resulted in a stimulation of the function of the microorganisms. The use of organic fertilizer resulted in an increase in amoA gene copy number by factor 100 compared to inorganic fertilizers. Our results support our hypothesis that the activity of the functional microbial community with respect to nitrogen turnover in an organic growing medium can be improved by selecting and mixing the appropriate growing media components with each other. These findings contribute to the understanding of the functional microbial community in growing media and its potential role towards a more responsible horticulture. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  12. Position and orientation determination system and method

    Science.gov (United States)

    Harpring, Lawrence J.; Farfan, Eduardo B.; Gordon, John R.; Jannik, Gerald T.; Foley, Trevor Q.

    2017-06-14

    A position determination system and method is provided that may be used for obtaining position and orientation information of a detector in a contaminated room. The system includes a detector, a sensor operably coupled to the detector, and a motor coupled to the sensor to move the sensor around the detector. A CPU controls the operation of the motor to move the sensor around the detector and determines distance and angle data from the sensor to an object. The method includes moving a sensor around the detector and measuring distance and angle data from the sensor to an object at incremental positions around the detector.

  13. Isotopic ratio method for determining uranium contamination

    International Nuclear Information System (INIS)

    Miles, R.E.; Sieben, A.K.

    1994-01-01

    The presence of high concentrations of uranium in the subsurface can be attributed either to contamination from uranium processing activities or to naturally occurring uranium. A mathematical method has been employed to evaluate the isotope ratios from subsurface soils at the Rocky Flats Nuclear Weapons Plant (RFP) and demonstrates conclusively that the soil contains uranium from a natural source and has not been contaminated with enriched uranium resulting from RFP releases. This paper describes the method used in this determination which has widespread application in site characterizations and can be adapted to other radioisotopes used in manufacturing industries. The determination of radioisotope source can lead to a reduction of the remediation effort

  14. Comparison between two plant nitrogen and sulphur determination methods: impact on wheat sulphur diagnostics Comparación de métodos de determinación de nitrógeno y azufre en planta: implicancia en el diagnóstico de azufre en trigo

    Directory of Open Access Journals (Sweden)

    Nahuel I Reussi Calvo

    2008-12-01

    Full Text Available The nitrogen and sulphur ratio (N:S in plants is often used as a sulphur diagnostics tool in wheat. This ratio requires two different analyses results for its calculation, and thus involves two sources of analytical error. The objective of this work was to compare the accuracy and reliability of the Dumas dry combustion method for N and S determination in plant, compared to traditional methods of wet digestion, and its use as a sulphur diagnostics tool in wheat. The N and S determination was carried out in wheat plant samples from four experiments carried out in the 2006 growing season in the southwestern Buenos Aires province. A highly significant correlation was obtained between both methods (r = 0.99 and r = 0.74 for N and S, respectively. The quantity of N recuperated by the Dumas method was not significantly different to the Kjeldahl method, however, the reliability of the former was higher (low variability coefficient. The method of turbidimetry with wet digestion underestimated (20% the sulphur concentration compared to the Dumas method. Moreover, the sulphur percent recovered from standard samples was 83 % and 96 % for the turbidimetry and Dumas methods, respectively. The underestimation of plant sulphur concentration by the turbidimetry method resulted in a low percentage of samples correctly diagnosed (25, 18.7 and 50% for Z22, Z24 and Z31, respectively. However, the percent of samples correctly diagnosed was high by the Dumas method (94, 94 and 100% for Z22, Z24 and Z31, respectively. The results of this work indicate that the reliability of the N:S ratio is limited by the S analysis accuracy. On the other hand, the N recovery for both methods was similar.La relación nitrógeno (N: azufre (S total es utilizada frecuentemente para el diagnóstico de deficiencias de S en trigo. Para determinar este índice es necesario la realización de dos análisis diferentes, y por lo tanto, es afectada por dos errores analíticos. El objetivo fue

  15. Nitrogen doped silicon-carbon multilayer protective coatings on carbon obtained by TVA method

    Science.gov (United States)

    Ciupina, Victor; Vasile, Eugeniu; Porosnicu, Corneliu; Lungu, Cristian P.; Vladoiu, Rodica; Jepu, Ionut; Mandes, Aurelia; Dinca, Virginia; Caraiane, Aureliana; Nicolescu, Virginia; Cupsa, Ovidiu; Dinca, Paul; Zaharia, Agripina

    2017-08-01

    Protective nitrogen doped Si-C multilayer coatings on carbon, used to improve the oxidation resistance of carbon, were obtained by Thermionic Vacuum Arc (TVA) method. The initial carbon layer having a thickness of 100nm has been deposed on a silicon substrate in the absence of nitrogen, and then a 3nm Si thin film to cover carbon layer was deposed. Further, seven Si and C layers were alternatively deposed in the presence of nitrogen ions, each having a thickness of 40nm. In order to form silicon carbide at the interface between silicon and carbon layers, all carbon, silicon and nitrogen ions energy has increased up to 150eV . The characterization of microstructure and electrical properties of as-prepared N-Si-C multilayer structures were done using Transmission Electron Microscopy (TEM, STEM) techniques, Thermal Desorption Spectroscopy (TDS) and electrical measurements. Oxidation protection of carbon is based on the reaction between oxygen and silicon carbide, resulting in SiO2, SiO and CO2, and also by reaction involving N, O and Si, resulting in silicon oxynitride (SiNxOy) with a continuously variable composition, and on the other hand, since nitrogen acts as a trapping barrier for oxygen. To perform electrical measurements, 80% silver filled two-component epoxy-based glue ohmic contacts were attached on the N-Si-C samples. Electrical conductivity was measured in constant current mode. The experimental data show the increase of conductivity with the increase of the nitrogen content. To explain the temperature behavior of electrical conductivity we assumed a thermally activated electric transport mechanism.

  16. Fertilizer nitrogen leaching in relation to water regime and the fertilizer placement method

    International Nuclear Information System (INIS)

    Moustafa, A.T.A.; Khadr, M.S.

    1983-01-01

    A field experiment was conducted at the farm of Sids Experimental Station, Ministry of Agriculture, Middle Egypt, to evaluate the effect of the water regime and fertilizer placement method on the leaching of urea fertilizer under field conditions. Ordinary and heavy irrigations were the water regimes, while side-banding and surface broadcasting were the fertilizer placement methods. Wheat (Giza 158, local variety) was planted, and urea labelled with 15 N at the rate of 100 kg N/ha was added at planting. The data obtained showed that in general the leaching process of urea fertilizer, as evaluated from the amounts of fertilizer nitrogen residues, is not uniform even within replicates. This is despite the fact that the average total amount of fertilizer nitrogen residues in the soil profile to a depth of 125 cm is almost the same in the different treatments. Data also show that the bulk of fertilizer nitrogen residues is accumulated in the surface soil layers, especially at 0-25 cm. Only 10% of the fertilizer nitrogen is detected below 75 cm and up to 125 cm depth of the soil profile. It could be concluded that urea leaching (amount and depth) under these conditions is affected mainly by the soil characteristics, namely soil pores. This is in addition to some other factors that cause variable concentrations in the soil solution leaving the root zone. (author)

  17. Analytical methods for the determination of tungsten

    International Nuclear Information System (INIS)

    Topping, J.J.

    1978-01-01

    Methods developed and employed in the recent literature (1969 to 1975) for the detection and determination of tungsten in a wide variety of matrices are reviewed. This paper is a supplement to the books, monographs and review papers which deal with the earlier literature. (author)

  18. Method of Determining Reflections of Light

    DEFF Research Database (Denmark)

    2017-01-01

    A method of filtering glints by processing an image of a user's cornea to obtain coordinates of desired glints from a configuration of light sources, comprising processing an image, in a first image space, of a user's cornea to determine coordinates of respective multiple positions of glints...

  19. A method to determine methylmethacrylate in air

    DEFF Research Database (Denmark)

    Darre, E; Gottlieb, J; Nielsen, P M

    1988-01-01

    To determine the air concentrations of methylmethacrylate monomer and thus obtain information about the safety in the operating theater, a methylmethacrylate Dräger tube was used in connection with a bellows pump. This method gives an instantly readable value correlated with more complicated gas...

  20. Particulate carbon and nitrogen determinations in tracer studies: The neglected variables

    International Nuclear Information System (INIS)

    Collos, Yves; Jauzein, Cécile; Hatey, Elise

    2014-01-01

    We address two issues in the determination of particulate carbon and nitrogen in suspended matter of aquatic environments. One is the adsorption of dissolved organic matter on filters, leading to overestimate particulate matter. The second is the material loss during filtration due to fragile algal cells breaking up. Examples from both laboratory cultures and natural samples are presented. We recommend using stacked filters in order to estimate the first and filtering different volumes of water in order to evaluate the second. - Highlights: • Adsorption of dissolved organic matter on GF/F filters saturates below 1 ml. • Such adsorption can overestimate (up to 5 fold at low volumes) particulate matter. • Plankton breakage during filtration underestimates (up to 3 fold) particulate matter. • Different volumes should be filtered to detect biases in PC and PN concentrations. • Adsorbed organic carbon is higher in surface ocean than in mid-waters

  1. Spectrophotometric methods for determining noble metals

    International Nuclear Information System (INIS)

    Gur'eva, R.F.; Savvin, S.B.

    2002-01-01

    The main trends of the development of spectrophotometric methods for determining noble metals (NMs) including ruthenium are considered. One of these trends is the synthesis and study of new, highly sensitive and selective organic reagents for determining NMs in solutions and solid phase. Another trend is the search for and developing of new methodological approaches (techniques) and color reactions, including those that involve modified and immobilized reagents. The third trend includes the improvement of equipment and automation. It is shown that the present-day spectrophotometry can provide the determination of NMs in samples with concentrations from several to 10 -4 % (photometry and differential photometry) and down to 10 -7 % (test and sorption-spectroscopic methods based on photometry and diffuse-reflectance spectroscopy, including the use of chromaticity functions) [ru

  2. Design of a nitrogen purification system with cryogenic method for neutrino detection.

    Science.gov (United States)

    Peng, Zhang; Zhongjun, Hu; Bingming, Wang; Qing, Li

    2018-04-04

    In order to detect the neutrino with liquid scintillation detector, high-purity nitrogen is essential for gas stripping in this detector. Therefore, it is necessary to design a purification system for the detector to purify nitrogen. Using the method of low temperature adsorption for the purification system, the key designs including the flow path, the adsorber and the selection of activated carbon, are introduced in this study. In these designs, the selection of activated carbon is the most important because the adsorption characteristic of the carbon is related to the performance of the purification system. The method of grand canonical ensemble Monte Carlo is adopted to simulate the adsorption of radon by the activated carbon with its slit pore model. Using this method, the working temperature and the key characteristic of the activated carbon are obtained. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. A method for measuring element fluxes in an undisturbed soil: nitrogen and carbon from earthworms

    International Nuclear Information System (INIS)

    Bouche, M.B.

    1984-01-01

    Data on chemical cycles, as nitrogen or carbon cycles, are extrapolated to the fields or ecosystems without the possibility for checking conclusions; i.e. from scientific knowledge (para-ecology). A new method, by natural introduction of an earthworm compartment into an undisturbed soil, with earthworms labelled both by isotopes ( 15 N, 14 C) and by staining is described. This method allows us to measure fluxes of chemicals. The first results, gathered during the improvement of the method in partly artificial conditions, are cross-checked with other data given by direct observation in the field. Measured flux (2.2 mg N/g fresh mass empty gut/day/15 0 C) is far more important than para-ecological estimations; animal metabolism plays directly an important role in nitrogen and carbon cycles. (author)

  4. Methods for determining time of death.

    Science.gov (United States)

    Madea, Burkhard

    2016-12-01

    Medicolegal death time estimation must estimate the time since death reliably. Reliability can only be provided empirically by statistical analysis of errors in field studies. Determining the time since death requires the calculation of measurable data along a time-dependent curve back to the starting point. Various methods are used to estimate the time since death. The current gold standard for death time estimation is a previously established nomogram method based on the two-exponential model of body cooling. Great experimental and practical achievements have been realized using this nomogram method. To reduce the margin of error of the nomogram method, a compound method was developed based on electrical and mechanical excitability of skeletal muscle, pharmacological excitability of the iris, rigor mortis, and postmortem lividity. Further increasing the accuracy of death time estimation involves the development of conditional probability distributions for death time estimation based on the compound method. Although many studies have evaluated chemical methods of death time estimation, such methods play a marginal role in daily forensic practice. However, increased precision of death time estimation has recently been achieved by considering various influencing factors (i.e., preexisting diseases, duration of terminal episode, and ambient temperature). Putrefactive changes may be used for death time estimation in water-immersed bodies. Furthermore, recently developed technologies, such as H magnetic resonance spectroscopy, can be used to quantitatively study decompositional changes. This review addresses the gold standard method of death time estimation in forensic practice and promising technological and scientific developments in the field.

  5. Response of Cotton to Irrigation Methods and Nitrogen Fertilization: Yield Components, Water-Use Efficiency, Nitrogen Uptake, and Recovery

    International Nuclear Information System (INIS)

    Janat, M.

    2009-01-01

    Efficient crop use of nitrogen (N) fertilizer is critical from economic and environmental viewpoints, especially under irrigated conditions. Cotton yield parameters, fiber quality, water- and N-use efficiency responses to N, and irrigation methods in northern Syria were evaluated. Field trials were conducted for two growing seasons on a Chromoxerertic Rhodoxeralf soil. Treatments consisted of drip fertigation, furrow irrigation, and five different rates of N fertilizer (50, 100, 150, 200, and 250 kg N /ha). Cotton was irrigated when soil moisture in the specified active root depth was 80% of the field capacity as indicated by the neutron probe. Seed cotton yield was higher than the national average (3,928 kg/ha) by at least 12% as compared to all treatments. Lint properties were not negatively affected by the irrigation method or N rates. Water savings under drip fertigation ranged between 25 and 50% of irrigation water relative to furrow irrigation. Crop water-use efficiencies of the drip-fertigated treatments were in most cases 100% higher than those of the corresponding furrow-irrigated treatments. The highest water demand was during the fruit-setting growth stage. It was also concluded that under drip fertigation, 100 -150 N kg/ha was adequate and comparable with the highest N rates tested under furrow irrigation regarding lint yield, N uptake, and recovery. Based on cotton seed yield and weight of stems, the overall amount of N removed from the field for the drip-fertigated treatments ranged between 101-118 kg and 116-188 N/ha for 2001 and 2002, respectively. The N removal ranged between 94-113 and 111-144 kg N/ha for the furrow-irrigated treatments for 2001 and 2002, respectively. (author)

  6. Growth and yield of cucumber as influenced by compost and nitrogen fertilizer in sandy soils using the nuclear technique for determination of nitrogen

    International Nuclear Information System (INIS)

    El-Sherif, M.F.A.

    2005-01-01

    this study was carried out during the period from 2002 to 2003 seasons, at the department of plant research, Nuclear Research Center (NRC,) Atomic Energy Authority (AEA), Egypt, on cucumber plants c.v. dp007 F1 (wafer). the main objective of this work was to study the effect of compost type, application level and nitrogen rate on vegetative growth, chemical composition, early and total yield and to determine the fertilizer nitrogen uptake and utilization by the cucumber plant and its parts, i.e., shoots and fruits . results revealed that the sugar cane bagasse compost (SC) gave a significantly higher response with most vegetative growth expressed as plant length, leaf number and dry weight of cucumber plant, compared with beet compost (BC). the application of compost from 2 up to 6 ton/fed

  7. Method for determining heterologous biosynthesis pathways

    KAUST Repository

    Gao, Xin

    2017-08-10

    The present invention relates to a method and system for dynamically analyzing, determining, predicting and displaying ranked suitable heterologous biosynthesis pathways for a specified host. The present invention addresses the problem of finding suitable pathways for the endogenous metabolism of a host organism because the efficacy of heterologous biosynthesis is affected by competing endogenous pathways. The present invention is called MRE (Metabolic Route Explorer), and it was conceived and developed to systematically and dynamically search for, determine, analyze, and display promising heterologous pathways while considering competing endogenous reactions in a given host organism.

  8. Determination of lithium in rocks: Fluorometric method

    Science.gov (United States)

    White, C.E.; Fletcher, M.H.; Parks, J.

    1951-01-01

    The gravimetric method in general use for the determination of lithium is tedious, and the final weighed product often contains other alkali metals. A fluorometric method was developed to shorten the time required for the analysis and to assure that the final determination is for lithium alone. This procedure is based on the complex formed between lithium and 8-hydroxyquinoline. The fluorescence is developed in a slightly alkaline solution of 95% alcohol and measurement is made on a photoelectric fluorometer. Separation from the ore is carried out by the wet method or by the distillation procedure. Sodium and potassium are removed by alcohol and ether, but complete separation is not necessary. Comparison of analyzed samples shows excellent agreement with spectrographic and gravimetric methods. The fluorometric method is more rapid than the gravimetric and produces more conclusive results. Another useful application is in the preparation of standard lithium solutions from reagent quality salts when a known standard is available. In this case no separations are necessary.

  9. Determination of symbiotic nitrogen fixation by labelling the soil atmosphere with sup(15)N sub(2) at low isotope enrichment

    International Nuclear Information System (INIS)

    Trivelin, P.C.O.

    1982-01-01

    A direct method to determine the total symbiotic nitrogen fixation during the leguminous plants cycles has been, developed, by labelling the soil atmosphere with sup(15)N sub(2) at low isotope enrichment, of about 1 atom % excess. The soil explored by the root system of leguminous plants was confined by means of a chamber in the field and by sealed pots in greenhouse experiments in order to maintain the soil air labelled with sup(15)N sub(2). The average sup(15)N concentration in the soil atmosphere, necessary to calculate dinitrogen fixation, was obtained by integration of the exponential functions of isotope dilution. Those functions were obtained by periodic sampling and analysis of the N sub(2) in the soil atmosphere. The field experiment with labelled atmosphere was carried out from the 22 sup(nd) to the 31 sup(st) day of the bean crop cycle and 5.5 mg N/plant (24% of total plant N) was derived from fixation. In pot experiments, under greenhouse conditions, integrated determination of fixation was made in Phaseolus beans (from the 19 sup(th) to the 67 sup(th) day from planting) and in soybeans (from the 24 sup(th) to the 70 sup(th) day from planting). The soil atmosphere was labelled with sup(15)N sub(2) in both cases. Average fixation obtained for Phaseolus beans was 80 mg N/plant (65% of total plant N) and for soybeans 265 mg N/plant (71% of total plant N). Evaluation of the basic concept of the isotope dilution method to determine nitrogen fixation in pots experiments, as proposed by Fried and Middelboe (1977) has also been made in the present paper. Simultaneous determinations of fixation in soybeans, using the isotope dilution method of Fried and Middelboe, natural variation of the sup(15)N/ sup(14)N ratios, and total-N differences, indicated the same results for pot experiments, harvested at the end of the plant cycle. (author)

  10. Conductometric titration to determine total volatile basic nitrogen (TVB-N) for post-mortem interval (PMI).

    Science.gov (United States)

    Xia, Zhiyuan; Zhai, Xiandun; Liu, Beibei; Mo, Yaonan

    2016-11-01

    Precise measurement of cadaver decomposition rate is the basis to accurate post-mortem interval (PMI) estimation. There are many approaches explored in recent years, however, it is still unsolved completely. Total volatile basic nitrogen (TVB-N), which is an important index to predict meat freshness and shelf life in food science, could serve as an indicator for measuring PMI associated decomposition rate of cadavers. The aim of this work was to establish a practical method to determine TVB-N in cadaver soft tissues (mainly skeletal muscle) for measuring decomposition rate. Determination of TVB-N in the simulation and animal experiments was conducted by steam distillation and conductometric titration using Kjeldahl distillation unit and conductivity meter. In simulation, standard concentrations of ammonium were used as TVB analogies, TVB-N contents were determined and the recovery rates of nitrogen were calculated. In animal experiment, TVB-N in skeletal muscle of forty-two rats was determined at different PMIs for 312 h at 24 °C ± 1 °C. The relationship between PMI and TVB-N was investigated also. The method showed high precision with 99%-100% recovery rates. TVB-N in skeletal muscle changed significantly with PMI especially after 24 h, and the data fit well to y = 3.35 E -5 x 3 -2.17 E -2 x 2 +6.13x-85.82 (adj. R 2  = 0.985). EC i (initial electrical conductivity in the samples just before titration) had positive linear relationship to final measured TVB-N values, y = 1.98x+16.16 (adj. R 2  = 0.985). The overall results demonstrated that the method is accurate, rapid and flexible, which could be expected as a basic technique for measuring decomposition rate in later PMI-estimation researches. Further studies are needed to validate our findings. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  11. A genome-wide identification of chromosomal regions determining nitrogen use efficiency components in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Cormier, Fabien; Le Gouis, Jacques; Dubreuil, Pierre; Lafarge, Stéphane; Praud, Sébastien

    2014-12-01

    This study identified 333 genomic regions associated to 28 traits related to nitrogen use efficiency in European winter wheat using genome-wide association in a 214-varieties panel experimented in eight environments. Improving nitrogen use efficiency is a key factor to sustainably ensure global production increase. However, while high-throughput screening methods remain at a developmental stage, genetic progress may be mainly driven by marker-assisted selection. The objective of this study was to identify chromosomal regions associated with nitrogen use efficiency-related traits in bread wheat (Triticum aestivum L.) using a genome-wide association approach. Two hundred and fourteen European elite varieties were characterised for 28 traits related to nitrogen use efficiency in eight environments in which two different nitrogen fertilisation levels were tested. The genome-wide association study was carried out using 23,603 SNP with a mixed model for taking into account parentage relationships among varieties. We identified 1,010 significantly associated SNP which defined 333 chromosomal regions associated with at least one trait and found colocalisations for 39 % of these chromosomal regions. A method based on linkage disequilibrium to define the associated region was suggested and discussed with reference to false positive rate. Through a network approach, colocalisations were analysed and highlighted the impact of genomic regions controlling nitrogen status at flowering, precocity, and nitrogen utilisation on global agronomic performance. We were able to explain 40 ± 10 % of the total genetic variation. Numerous colocalisations with previously published genomic regions were observed with such candidate genes as Ppd-D1, Rht-D1, NADH-Gogat, and GSe. We highlighted selection pressure on yield and nitrogen utilisation discussing allele frequencies in associated regions.

  12. Nitrogen deposition's role in determining forest photosynthetic capacity; a FLUXNET synthesis

    Science.gov (United States)

    Fleischer, K.; Rebel, K.; van der Molen, M.; Erisman, J.; Wassen, M.; Dolman, H.

    2011-12-01

    There is growing evidence that nitrogen (N) deposition stimulates forest growth, as many forest ecosystems are N-limited. However, the significance of N deposition in determining the strength of the present and future terrestrial carbon sink is strongly debated. We investigated and quantified the effect of N deposition on ecosystem photosynthetic capacity (Amax) with the FLUXNET database, including 80 forest sites, covering the major forest types and climates of the world. The relative effect of climate and N deposition on photosynthesis was assessed with regression models. We found a significant positive correlation of Amax and N deposition for evergreen needleleaf forests in our dataset. We further found indications that foliar N and LAI scale positively with N deposition, reflecting the 2 mechanisms at which N is believed to cause an increase in carbon gain. We can support the hypothesis that foliar N is the principal scaling factor for canopy Amax across all forest types. Deciduous forests are less diverse in terms of climate and nutritional conditions for the included sites and these forests exhibited weak to no correlations with the included climate and N predictor variables. Quantifying the effect of N deposition on photosynthetic rates at the canopy level is an essential step for quantifying its contribution to the terrestrial carbon sink and for predicting vegetation response to N fertilization and global change in the future. The approach shows that eddy-covariance measurements of carbon fluxes at the canopy scale allow us to test hypotheses with respect to the expected nitrogen-photosynthesis relationships at the canopy scale.

  13. Prolonged pregnancy: Methods, Causal Determinants and Outcome

    DEFF Research Database (Denmark)

    Olesen, Annette Wind

    Summary Prolonged pregnancy, defined as a pregnancy with a gestational length of 294 days or more, is a frequent condition. It is associated with an increased risk of fetal and maternal complications. Little is known about the aetiology of prolonged pregnancy. The aims of the thesis were 1......) to study the incidence of prolonged pregnancy as a function of methods for determining gestational age; 2) to determine the risk of obstetrical and fetal complications in prolonged pregnancy; 3) to validate the self-reported gestational age in the National Birth Cohort; 4) to determine whether...... the risk of recurrence of prolonged pregnancy as a function of change in male partner and social conditions (IV). The National Birth Cohort provided data for the study on prenatal risk indicators of prolonged pregnancy in a follow-up design (V). The self-reported gestational ages from this database...

  14. Prolonged Pregnancy: Methods, Causal Determinants and Outcome

    DEFF Research Database (Denmark)

    Olesen, Annette Wind

    ) to study the incidence of prolonged pregnancy as a function of methods for determining gestational age; 2) to determine the risk of obstetrical and fetal complications in prolonged pregnancy; 3) to validate the self-reported gestational age in the National Birth Cohort; 4) to determine whether...... an ultrasound scan in the first or second trimester, or menstrual history was best at predicting the day of delivery; 5) to study the risk of recurrence of prolonged pregnancy as a function of change in male partner, social status and municipality; and 6) to detect prenatal risk indicators of prolonged...... of perinatal and obstetrical complications was high in post-term delivery compared to term delivery (OR between 1.2 and 3.1). The risk of perinatal death (OR=1.36 (1.08-1.72)) was also higher in the post-term group (I). The self-reported gestational ages in the National Birth Cohort correlated well with data...

  15. Fluorimetric method for determination of Beryllium

    International Nuclear Information System (INIS)

    Sparacino, N.; Sabbioneda, S.

    1996-10-01

    The old fluorimetric method for the determination of Beryllium, based essentially on the fluorescence of the Beryllium-Morine complex in a strongly alkaline solution, is still competitive and stands the comparison with more modern methods or at least three reasons: in the presence of solid or gaseous samples (powders), the times necessary to finalize an analytic determination are comparable since the stage of the process which lasts the longest is the mineralization of the solid particles containing Beryllium, the cost of a good fluorimeter is by far Inferior to the cost, e. g., of an Emission Spectrophotometer provided with ICP torch and magnets for exploiting the Zeeman effect and of an Atomic absorption Spectrophotometer provided with Graphite furnace; it is possible to determine, fluorimetrically, rather small Beryllium levels (about 30 ng of Beryllium/sample), this potentiality is more than sufficient to guarantee the respect of all the work safety and hygiene rules now in force. The study which is the subject of this publication is designed to the analysis procedure which allows one to reach good results in the determination of Beryllium, chiefly through the control and measurement of the interference effect due to the presence of some metals which might accompany the environmental samples of workshops and laboratories where Beryllium is handled, either at the pure state or in its alloys. The results obtained satisfactorily point out the merits and limits of this analytic procedure

  16. Determination of actinides by alpha spectrometric methods

    International Nuclear Information System (INIS)

    Galanda, D.

    2011-01-01

    The submitted thesis in its first part concern with content determination of plutonium, americium, uranium, thorium radionuclides, like the most significant representatives of actinides in environmental patterns, where by the primary consideration is a focusing on content of these actinides in samples of superior mycotic organisms - mushrooms. Following the published studies the mushrooms were monitored as organisms that could verify most of attributes putted on bioindicators in term of observation of substantial radionuclides in living environment. There were analyzed two groups of samples that came from two chosen locations, one of them is situated in Eastern Slovakia and the second one in West Slovakia. Except for mushrooms samples the examined radionuclides volumes were determined even in specimens of soil sub-base and some plants from chosen localities. The liquid - liquid extraction methods were used for determination of mass activities of actinides in samples for radiochemical separation of monitored radionuclides. The obtained results of plutonium and americium mass activities determination's lead us to carry out experiments that proved abilities of superior mycotic organisms to absorb and accumulate alpha radionuclides in their textures. We choose the oyster mushroom (Pleurotus ostreatus) species as an experimental object. Sporocarps of this mushroom were cultivated on substratum which is commercially exploited to cultivate it whereby this substratum was purposely contaminated by known activities of 239 Pu and 241 Am. We prepared five autonomous samples together. The values of mass activities of 239 Pu and 241 Am obtained by following analysis of prepared samples showed the ability of mushrooms to absorb observed actinides in their texture structures. On the basis of obtained mass activities it was possible to evaluate and numerically determine a transmitting factor's attributes of monitored radionuclides in sporocarps and in sub-base. Accordingly we

  17. Potential for chlorate interference in ion chromatographic determination of total nitrogen in natural waters following alkaline persulfate digestion.

    Science.gov (United States)

    Halstead, J A; Edwards, J; Soracco, R J; Armstrong, R W

    1999-10-01

    Determination of total nitrogen in aqueous samples after thermal potassium peroxydisulfate (persulfate) digestion is a commonly used alternative to the tedious Kjeldahl procedure. When ion chromatography is used to quantify the nitrate formed during digestion, there is a potential for interference from a chlorate peak if the digested sample initially contained chloride in concentrations close to or greater than the concentration of nitrogen. It was determined that this interference can be avoided either by using chromatographic conditions which cleanly resolve the nitrate and chlorate peaks (e.g., the Dionex AG9-HG column) or by using digestion reagent concentrations chosen to maintain a high pH throughout the digestion. The second alternative is not a viable option for investigators using a single digestion for both total nitrogen (TN) and total phosphorus (TP) analysis.

  18. Nitrogen content determinations in different stages of thermal treatment involved in conversion of ammonium diuranate to uranium metal

    International Nuclear Information System (INIS)

    Shrivastava, K.C.; Shelke, G.P.

    2017-01-01

    Determination of nitrogen content in the uranium metal and uranium oxide based reactor fuels is important to meet the requirement of specifications given by fuel designer. Therefore, a systematic study was carried out to determine the variations in nitrogen content during the conversion of ammonium diuranate (ADU) to uranium oxides (UO 3 and UO 2 ), and finally to uranium metal by inert gas fusion-thermal conductivity detection (IGF-TCD) technique. To understand the measured nitrogen content variations, the thermal decomposition study of ADU was carried out using thermogravimetry (TG)/differential thermogravimetry (DTG) and differential thermal analysis (DTA) in the temperature range of 25-1073 K. Powder X-ray diffraction (XRD) technique was used to confirm the formation of uranium oxide precursors at different temperature. (author)

  19. Distribution of nitrogen in nature and its separation

    International Nuclear Information System (INIS)

    Nitzsche, H.M.; Haendel, D.; Muehle, K.

    1981-01-01

    Proceeding from a survey on nitrogen in the atmosphere, biosphere, hydrosphere, and lithosphere and nitrogen determination methods, a detailed review is given of procedures that allow to transform any nitrogen-containing starting material into molecular nitrogen for mass spectroscopic isotope analysis

  20. Simultaneous cardiac output and regional myocardial perfusion determination with PET and nitrogen 13 ammonia

    DEFF Research Database (Denmark)

    Hove, Jens D; Kofoed, Klaus F; Wu, Hsiao M

    2003-01-01

    The purpose of this study was to evaluate the possibility of measuring cardiac output during positron emission tomography (PET) examination of myocardial perfusion with nitrogen 13 ammonia.......The purpose of this study was to evaluate the possibility of measuring cardiac output during positron emission tomography (PET) examination of myocardial perfusion with nitrogen 13 ammonia....

  1. Determination of the Fate of Dissolved Organic Nitrogen in the Three Wastewater Treatment Plants, Jordan

    Science.gov (United States)

    Wedyan, Mohammed; Al Harahsheh, Ahmed; Qnaisb, Esam

    2016-01-01

    This research aimed to assess the composition of total dissolved nitrogen (TDN) species, particularly dissolved organic nitrogen (DON), over the traditional wastewater treatment operations in three biological nutrient removal (BNR) wastewater treatment plants (WWTPs) in Jordan. It had been found that the DON percentage was up to 30% of TDN within…

  2. Nitrogen availability is a primary determinant of conifer mycorrhizas across complex environmental gradients

    Science.gov (United States)

    Filipa Cox; Nadia Barsoum; Erik A. Lilleskov; Martin I. Bidartondo

    2010-01-01

    Global environmental change has serious implications for functional biodiversity in temperate and boreal forests. Trees depend on mycorrhizal fungi for nutrient uptake, but predicted increases in nitrogen availability may alter fungal communities. To address a knowledge gap regarding the effects of nitrogen availability on mycorrhizal communities at large scales, we...

  3. Evaluation of determinative methods for sodium impurities

    International Nuclear Information System (INIS)

    Molinari, Marcelo; Guido, Osvaldo; Botbol, Jose; Ares, Osvaldo

    1988-01-01

    Sodium, universally accepted as heat transfer fluid in fast breeder reactors, requires a special technology for every operation involved in any applicable methodology, due to its well known chemical reactivity. The purpose of this work is: a) to study the sources and effects of chemical species which, as traces, accompany sodium used in the nuclear field; b) to classify, taking into account, the present requirements and resources of the National Atomic Energy Commission (CNEA), the procedures found in the literature for determination of the most important impurities which exist in experimental liquid sodium systems and c) to describe the principles of the methods and to evaluate them in order to make a selection. It was concluded the convenience to develop, as a first stage, laboratory procedures to determine carbon, oxygen, hydrogen and non-volatile impurities, which besides serving present needs, will be referential for direct methods with undeferred response. The latter are needed in liquid sodium experimental loops and require, primarily, more complex and extended development. Additionally, a description is made of experimental work performed up-to-now in this laboratory, consisting of a transfer device for sodium sampling and a sodium distillation device, adapted from a previous design, with associated vacuum and inert gas systems. It is intended as a separative technique for indirect determination of oxygen and non-volatile impurities. (Author) [es

  4. Combined method for reducing emission of sulfur dioxide and nitrogen oxides from thermal power plants

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Grachev, S.P.

    1991-11-01

    Discusses the method developed by the Fossil Energy Research Corp. in the USA for combined desulfurization and denitrification of flue gases from coal-fired power plants. The method combines two methods tested on a commercial scale: the dry additive method for suppression of sulfur dioxide and the selective noncatalytic reduction of nitrogen oxides using urea (the NOXOUT process). The following aspects of joint flue gas desulfurization and denitrification are analyzed: flowsheets of the system, chemical reactions and reaction products, laboratory tests of the method and its efficiency, temperature effects on desulfurization and denitrification of flue gases, effects of reagent consumption rates, operating cost, efficiency of the combined method compared to other conventional methods of separate flue gas desulfurization and denitrification, economic aspects of flue gas denitrification and desulfurization. 4 refs.

  5. Determination of critical nitrogen dilution curve based on stem dry matter in rice.

    Directory of Open Access Journals (Sweden)

    Syed Tahir Ata-Ul-Karim

    Full Text Available Plant analysis is a very promising diagnostic tool for assessment of crop nitrogen (N requirements in perspectives of cost effective and environment friendly agriculture. Diagnosing N nutritional status of rice crop through plant analysis will give insights into optimizing N requirements of future crops. The present study was aimed to develop a new methodology for determining the critical nitrogen (Nc dilution curve based on stem dry matter (SDM and to assess its suitability to estimate the level of N nutrition for rice (Oryza sativa L. in east China. Three field experiments with varied N rates (0-360 kg N ha(-1 using three Japonica rice hybrids, Lingxiangyou-18, Wuxiangjing-14 and Wuyunjing were conducted in Jiangsu province of east China. SDM and stem N concentration (SNC were determined during vegetative stage for growth analysis. A Nc dilution curve based on SDM was described by the equation (Nc = 2.17W(-0.27 with W being SDM in t ha(-1, when SDM ranged from 0.88 to 7.94 t ha(-1. However, for SDM < 0.88 t ha(-1, the constant critical value Nc = 1.76% SDM was applied. The curve was dually validated for N-limiting and non-N-limiting growth conditions. The N nutrition index (NNI and accumulated N deficit (Nand of stem ranged from 0.57 to 1.06 and 51.1 to -7.07 kg N ha(-1, respectively, during key growth stages under varied N rates in 2010 and 2011. The values of ΔN derived from either NNI or Nand could be used as references for N dressing management during rice growth. Our results demonstrated that the present curve well differentiated the conditions of limiting and non-limiting N nutrition in rice crop. The SDM based Nc dilution curve can be adopted as an alternate and novel approach for evaluating plant N status to support N fertilization decision during the vegetative growth of Japonica rice in east China.

  6. Use of nitrogen cryogun for separating duct tape and recovery of latent fingerprints with a powder suspension method.

    Science.gov (United States)

    Bailey, James A; Crane, Jonathan Stuart

    2011-07-15

    Duct tape is sometimes recovered as physical evidence in crimes. The purpose of this study was to determine the quality of latent prints on the adhesive and non-adhesive surfaces of duct tape samples that were separated using three methods. Three hundred donor fingerprint impressions were deposited on duct tape. Sections of duct tape were affixed to sections of cardboard and a fingerprint placed on the non-adhesive surface of the tape. A second layer of duct tape was prepared and a fingerprint placed on the adhesive side of the tape and then the tape was affixed to the piece of tape on the cardboard. After a 24-h period, the samples were separated using gradual force, liquid nitrogen applied with a cryogun and an adhesive neutralizer to separate the layers of tape. The recovered fingerprints were processed with a fingerprint powder suspension method. The recovered fingerprint images were evaluated and rated as +1, +2, or +3. The liquid nitrogen spray separation method yielded the highest number of +3 prints. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Studies of the efficiency of nitrogen placement methods and slow release nitrogen fertilizers for rice and wheat, using N-15 labelled fertilizers

    International Nuclear Information System (INIS)

    Shaukat, A.

    1979-12-01

    A series of experiments with rice and wheat were carried out to study the efficiency of nitrogen placement methods and slow-release nitrogen fertilizers for these two crops using N-15-labelled fertilizer. The results show that (1) reduced N levels, of the order of 75 percent of the full recommended dose, are equally efficient as the full dose for wheat. The yield of rice grain increased with the increased dose of nitrogen; (2) Point placement of fertilizers for rice was superior to broadcast application in terms of uptake and yield. For optimum yield of wheat grain, urea should perferably be applied as a single dose banded between the rows at 5 cm depth or by broadcasting and incorporation in the soil at the time of sowing; (3) Sulphur-coated urea (SCU) at a comparable dose and mode of application gave better yields of rice grain than the application of urea and IBDU (Isobutylidine Diurea); (4) More nitrogen was taken up by wheat when SCU was applied. The best uptake was when it was applied half at sowing and half at tillering. The nitrogen uptake from the SCU by point placement was better for rice plants than broadcast application and was higher in magnitude than the IBDU

  8. Nitrogen in Chinese coals

    Science.gov (United States)

    Wu, D.; Lei, J.; Zheng, B.; Tang, X.; Wang, M.; Hu, Jiawen; Li, S.; Wang, B.; Finkelman, R.B.

    2011-01-01

    Three hundred and six coal samples were taken from main coal mines of twenty-six provinces, autonomous regions, and municipalities in China, according to the resource distribution and coal-forming periods as well as the coal ranks and coal yields. Nitrogen was determined by using the Kjeldahl method at U. S. Geological Survey (USGS), which exhibit a normal frequency distribution. The nitrogen contents of over 90% Chinese coal vary from 0.52% to 1.41% and the average nitrogen content is recommended to be 0.98%. Nitrogen in coal exists primarily in organic form. There is a slight positive relationship between nitrogen content and coal ranking. ?? 2011 Science Press, Institute of Geochemistry, CAS and Springer Berlin Heidelberg.

  9. Method for Determining the Time Parameter

    Directory of Open Access Journals (Sweden)

    K. P. Baslyk

    2014-01-01

    Full Text Available This article proposes a method for calculating one of the characteristics that represents the flight program of the first stage of ballistic rocket i.e. time parameter of the program of attack angle.In simulation of placing the payload for the first stage, a program of flight is used which consists of three segments, namely a vertical climb of the rocket, a segment of programmed reversal by attack angle, and a segment of gravitational reversal with zero angle of attack.The programed reversal by attack angle is simulated as a rapidly decreasing and increasing function. This function depends on the attack angle amplitude, time and time parameter.If the projected and ballistic parameters and the amplitude of attack angle were determined this coefficient is calculated based the constraint that the rocket velocity is equal to 0.8 from the sound velocity (0,264 km/sec when the angle of attack becomes equal to zero. Such constraint is transformed to the nonlinear equation, which can be solved using a Newton method.The attack angle amplitude value is unknown for the design analysis. Exceeding some maximum admissible value for this parameter may lead to excessive trajectory collapsing (foreshortening, which can be identified as an arising negative trajectory angle.Consequently, therefore it is necessary to compute the maximum value of the attack angle amplitude with the following constraints: a trajectory angle is positive during the entire first stage flight and the rocket velocity is equal to 0,264 km/sec by the end of program of angle attack. The problem can be formulated as a task of the nonlinear programming, minimization of the modified Lagrange function, which is solved using the multipliers method.If multipliers and penalty parameter are constant the optimization problem without constraints takes place. Using the determined coordinate descent method allows solving the problem of modified Lagrange function of unconstrained minimization with fixed

  10. Determination of carbon and nitrogen in litter fall of mangrove ecosystem in peninsular Malaysia

    International Nuclear Information System (INIS)

    Hemati, Z.; Hossain, M.

    2017-01-01

    Mangroves in Peninsular Malaysia are typical of tropical forest setting. Nevertheless, the state of the mangrove forests has led to various classifications; natural and degraded mangroves. The study aimed to utilize litter fall (production and standing crop) potential as a means of evaluating the degree of productivity of the mangrove types across seasons, in addition to determining the abundance of carbon and nitrogen in the Peninsular mangrove forest. Leaf litter accounted for more than 70% of the total litter production in both natural and degraded mangroves, and the peak month for such production was December; 82.7% and 82.2%, for Sungai Haji Dorani and Kuala Selangor Nature Park, respectively. The degraded mangrove recorded higher concentration of total N (6.16 mg/g) than the natural mangrove forest (5.60 mg/g) at significant level. However, the organic carbon (CO) content across the litter parts varied with the three seasons. The CO of leaf litter was at the peak during the dry season, however, analysis on the branch and fruit revealed that during the intermediate and wet seasons CO level could be higher than the concentration observed at dry season. Though, the study concluded that both mangrove types in Peninsular Malaysia showed high similarity in the degree of litter production, yet the identified differences suggest that counter measures need to be adopted in order to protect mangroves from degradation and possible productivity loss. (author)

  11. Short-term experiments for determination of the relative phytotoxicity of nitrogen dioxide

    Energy Technology Data Exchange (ETDEWEB)

    van Haut, H.

    1975-01-01

    In short-term experiments, the relative phytotoxicity of nitrogen dioxide was determined for 60 types of plants by comparing it with that of sulfur dioxide. The plants, which included crop and garden plants such as alfalfa, clover, barley, lettuce, carrots, parsley, radishes, onions, beans, and tobacco; ornamental plants, such as roses, dahlias, and gladioli; and coniferous and deciduous trees, such as pines, spruces, birches, and maples, were exposed to the two gases in parallel experiments. The exposure concentrations were 5 to 20 mg NO/sub 2/ cu/m air and 1.5 to 4 mg SO/sub 2//cu m air. Taking the average concentration ratio of SO/sub 2/ to NO/sub 2/ of 1/3.5 and an SO/sub 2/ long-term value of 0.1 mg SO/sub 2//cu m, an average value of 0.35 mg NO/sub 2//cu m of air was obtained for the vegetation half-year. The average value obtained for a 30-min period was 0.80 mg NO/sub 2//cu m of air.

  12. The determination of nitrogen in zirconium by charged-particle activation analysis

    International Nuclear Information System (INIS)

    Strijckmans, K.; Mortier, R.; Vandecasteele, C.; Hoste, J.

    1982-01-01

    The determination of nitrogen in zirconium by charged-particle activation analysis is described. The 14 N(α, αn) 13 N and the 14 N(p, α) 11 C reactions were used. The 13 N activity was separated from matrix activity as ammonia by steam-distillation after dissolution of the sample in dilute hydrofluoric acid.The 11 C activity was separated as carbon dioxide by dissolution of the sample in a mixture of concentrated sulphuric acid, sodium fluoride and potassium periodate, followed by oxidation of the evolved gases with a copper oxide-iron oxide-kaolin mixture and trapping of the carbon dioxide in dilute sodium hydroxide solution. The chemical yield of both separations was investigated. The nuclear interference of boron can be neglected, in view of the low boron content. Alpha- and protonactivation yielded the following results for BCR reference materials (alpha-activation results first): CRM 21: 24.6 +- 3.3 and 25.9 +- 0.8 μg/g (certified value: 26.4 +- 2.5 μg/g);CRM 56: 12.0 +- 1.1 and 10.5 +- 0.3 μg/g (certified value: 11.7 +- 1.7 μg/g); CRM 57: 11.2 +- 0.3 μg/g (alpha/activation) (certified value: 11.9 +- 1.8 μg/g). (Author)

  13. Determination of nitrogen in zirconium by charged-particle activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Strijckmans, K; Mortier, R; Vandecasteele, C; Hoste, J [Ghent Rijksuniversiteit (Belgium)

    1982-01-01

    The determination of nitrogen in zirconium by charged-particle activation analysis is described. The /sup 14/N(..cap alpha.., ..cap alpha..n)/sup 13/N and the /sup 14/N(p, ..cap alpha..)/sup 11/C reactions were used. The /sup 13/N activity was separated from matrix activity as ammonia by steam-distillation after dissolution of the sample in dilute hydrofluoric acid.The /sup 11/C activity was separated as carbon dioxide by dissolution of the sample in a mixture of concentrated sulphuric acid, sodium fluoride and potassium periodate, followed by oxidation of the evolved gases with a copper oxide-iron oxide-kaolin mixture and trapping of the carbon dioxide in dilute sodium hydroxide solution. The chemical yield of both separations was investigated. The nuclear interference of boron can be neglected, in view of the low boron content. Alpha- and protonactivation yielded the following results for BCR reference materials (alpha-activation results first): CRM 21: 24.6 +- 3.3 and 25.9 +- 0.8 ..mu..g/g (certified value: 26.4 +- 2.5 ..mu..g/g);CRM 56: 12.0 +- 1.1 and 10.5 +- 0.3 ..mu..g/g (certified value: 11.7 +- 1.7 ..mu..g/g); CRM 57: 11.2 +- 0.3 ..mu..g/g (alpha/activation) (certified value: 11.9 +- 1.8 ..mu..g/g).

  14. Calorimetry by immersion into liquid nitrogen and liquid argon: a better way to determine the internal surface area of micropores.

    Science.gov (United States)

    Navarrete, Ricardo; Llewellyn, Philip; Rouquerol, Françoise; Denoyel, Renaud; Rouquerol, Jean

    2004-09-15

    The aim of this work is to assess the internal surface area of a set of samples (either carbons or oxides, either porous or nonporous, either microporous or mesoporous) by microcalorimetry via immersion into liquid nitrogen or argon. We have made use of an isothermal, heat-flux microcalorimeter, initially designed and built in our laboratory for the sake of gas adsorption experiments at 77 or 87 K. It seems that immersion calorimetry into liquid nitrogen and argon makes it possible to go one step further in the determination of the internal surface area of micropores.

  15. Method Determining the Contents of the Contract

    Directory of Open Access Journals (Sweden)

    Agus Yudha Hernoko

    2017-03-01

    Full Text Available The contents of the contract are primarily determined by what the real mutually agreed upon by the parties. By interpreting some certain statements, in this case to determine its meaning, to be clear based on what the parties committed themselves. Why is the interpretation required? In facts, on the many cases provided a valuable lesson, how many commercial disputes arise when the performance of the contract. The dispute begins when the parties have a different understanding of the statement that they use in the contract. Indeed, businesses are very familiar with the business processes that they do, but at the time of the business process are set forth in the contract language and designed by those who do not understand the legal aspects of the contract, the contract can be ascertained open possibility for disputes. The power of contract binding (the contents of the agreement toward to the characteristic and the wide spectrum of the rights and obligations contractually, basically a contract represents the power of performance among others in order implementing the rights and obligations of the parties. As an instrument to understand the contract, the method of determining the content of the contract (e.g., through interpretation, autonomous and heteronomous factors, further can be used to assess the reciprocation of rights and obligations in a meaningful and proportional contractual relationship.

  16. Measurement of nitrogen fixation in beam (Phaseolus vulgaris L.) cv. carioca, using a 15N2 low enrichment method

    International Nuclear Information System (INIS)

    Trivelin, P.C.O.; Matsui, E.; Saito, S.M.T.; Libardi, P.L.; Salati, E.

    1984-01-01

    A experimental work under field conditions to develop a method to measure atmospheric N 2 -fixation by leguminous plants, using a low enrichment 15 N 2 technique, is carried out. The experiment was developed using a N 2 -fixation measuring chamber on Terra Roxa Estruturada. The beam plants had their aereal part under normal conditions and the rooting system confined, through which a mixture of Ar, O 2 and N 2 labelled with 15 N (1.9% atom excess) was circulated from the 22nd to the 31st day from planting. Samples of the gaseous Ar, O 2 and N 2 mixture were analysed by mass spectrometry to determine 15 N concentrations and O 2 and CO 2 contents. The N 2 -fixed was measured by determination of total-N and isotopic concentration of nitrogen in the plants. (M.A.C.) [pt

  17. Use of 15N dilution method for screening soybean lines with high yield and high nitrogen fixation ability

    International Nuclear Information System (INIS)

    Li Haixian; Li Xinmin; Danso, S.K.A.

    1998-01-01

    15 N dilution method was used for screening soybean lines with high nitrogen fixation ability. Screened lines 1005, 8502, 2096, 943, 1454 and Dongnong-42 have high nitrogen fixation ability with their % Ndfa of about 70%. 1454 and 1555 are both high yield and high nitrogen fixation lines. The ability of nitrogen fixation was not related to the yield, but related to maturing time. The cultivars with different maturing time have different levels of nitrogen fixation ability. The longer the maturing period is, the greater the ability of nitrogen fixation it has. There were ten cultivars or lines used in the test of 1992 and 1994. Although the weather condition were greatly different between the two years the results of seven cultivars or lines were the same, indicating that nitrogen fixation ability of the soybean is stable with years. Using 15 N dilution method to estimate nitrogen fixation ability of soybean is reliable, however, the % Ndfa of lines 8502 and 2096 increased by 19% in 1994, a rainy year, indicating that a change in % Ndfa with a few varieties maybe caused by weather

  18. Coincidence method for determination of radionuclides activities

    International Nuclear Information System (INIS)

    Andrukhovich, S.K.; Berestov, A.V.; Rudak, E.A.

    2004-01-01

    The radon and radium activity measurements using six-crystal gamma-gamma coincidence, 4 -spectrometer PRIPJAT and radioactivity measurements in different samples of meat and vegetation by 32-crystal spectrometer ARGUS, are described. Radiation detector with 4 -geometry provides higher efficiency, and therefore shorter counting time than a detector without such geometry. However, its application is limited by the fact that obtained spectrum contains summing peaks of all γ-quanta registered in coincidence. Multiparameter information on coincident photon emission can be obtained only by a detection system where the 4 -geometry is made by many detectors, such are both the PRIPJAT and the ARGUS - γ-coincidence spectrometer of the Crystal Ball type in the Institute of Physics, Minsk [1,2]. There are other characteristics, as background conditions, energy and time resolution, makes it ve suitable for investigation of rare decays and interactions, cascade transitions, k intensity radiations etc. We are developing a method of 2 26R a and 2 26 Rn measurement by a multidetector 4 -spectrometer. The method is based on coincidence counting of γ-rays from two step cascade transitions that follow - decay of 2 14 Bi. Its application to the PRIPL spectrometer, which has 6 Nal(Tl) detectors, is presented here, as well as the method of the determination of radionuclide activities based on the registration of the cascades intensity of γ-rays of different multiplicity using ARGUS

  19. Evaluation of body composition and nitrogen content of renal patients on chronic dialysis as determined by total body neutron activation

    International Nuclear Information System (INIS)

    Cohn, S.H.; Brennan, B.L.; Yasumura, S.; Vartsky, D.; Vaswani, A.N.; Ellis, K.J.

    1983-01-01

    Total body protein (nitrogen), body cell mass (potassium), fat, and water were measured in 15 renal patients on maintenance hemodialysis (MHD). Total body nitrogen was measured by means of prompt γ neutron activation analysis; total body water was determined with tritium labeled water; total body potassium was measured by whole body counting. The extracellular water was determined by a technique utilizing the measurement of total body chloride and plasma chloride. When compared with corresponding values of a control group of the same age, sex, and height, the protein content, body cell mass, and total body fat of the MHD patients were within the normal range. The only significant change was an increase in the extracellular water/body cell mass ratio in the male MHD patients compared to the control. The lack of significant difference of the nitrogen values of the MHD patients compared to matched controls suggests that dialysis minimizes any residual effects of uremic toxicity or protein-calorie malnutrition. These findings further suggest that there is a need to reevaluate the traditional anthropometric and biochemical standards of nutritional status for MHD patients. It was concluded that it is particularly important to measure protein stores of MHD patients with low protein intake to ascertain nutritional status. Finally, in vivo measurement of total body nitrogen and potassium for determination of body composition provides a simple, direct, and accurate assessment of the nutritional status of MHD patients

  20. Determination of volatile nitrosamines in grilled lamb and vegetables using comprehensive gas chromatography - nitrogen chemiluminescence detection.

    Science.gov (United States)

    Kocak, D; Ozel, M Z; Gogus, F; Hamilton, J F; Lewis, A C

    2012-12-15

    The grilling of meat may generate dangerous levels of mutagenic and carcinogenic nitrosamines (NAs). Meat and vegetable samples underwent a two-step solid-phase extraction before analysis by comprehensive gas chromatography with a nitrogen chemiluminescence detection system (GCxGC-NCD). The GCxGC-NCD method showed high selectivity, sensitivity and equimolarity in its response to six specific NAs. NA contamination of charcoal-grilled lamb at various stages of cooking and with various fat contents and also charcoal-grilled vegetables were investigated. The grilling of lamb on unready charcoal resulted in the formation of considerable quantities of NAs. Grilling lamb on properly prepared, ready charcoal resulted in an increase in total concentrations of six NAs from 0 to 4.51 μg kg(-1) over a period of 16 min. Increasing the fat content of the grilled lamb from 5% to 20% caused a modest increase in total concentrations of the six investigated NAs from 4.51 to 5.30 μg kg(-1). Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Determination of uranium by an amperometric method

    International Nuclear Information System (INIS)

    John, Mary; Venkataramana, P.; Vaidyanathan, S.; Natarajan, P.R.

    1981-01-01

    An amperometric method has been standardised for the determination of uranium. Uranium is reduced to its quadrivalent state in concentrated phosphoric acid medium with ferrous iron. The excess iron is destroyed with nitric acid in presence of Mo(VI). The medium is diluted and U(IV) is titrated with standard potassium dichromate to an amperometric end point using a pair of identical plantinum wires as electrodes. The reagent volumes and uranium quantities have been scaled down to 30 ml. and 2-5 mg of uranium in the present work with a view to minimising the problems associated with recovery of plutonium. The results are quantitative with an R.S.D. of 0.2% in the present version of weight based titrations. (author)

  2. The Multispecimen Method for Absolute Paleointensity Determination

    Science.gov (United States)

    Dekkers, M. J.; de Groot, L. V.; Monster, M.

    2015-12-01

    Paleointensity methods have seen a large improvement in the 21th century. This included optimizing classic Thellier-style protocols along with establishing stringent sets of quality criteria, developing microwave excitation as an alternative to thermal treatment, selecting sample material that contains the most suitable remanence carriers (i.e. single domain magnetic particles), calibrating non-heating paleointensity methods, and the introduction of the multispecimen paleointensity (MSP) protocol. An MSP experiment is carried out at one specific temperature selected to avoid thermochemical alteration; a series of specimens is heated and cooled in various applied furnace fields oriented parallel to the specimen's NRM. The furnace field value at which no change in NRM occurs is the paleofield. While the rationale of the MSP approach is surprisingly straightforward, some of the original claims (Dekkers and Böhnel, 2006) are by now shown to be untenable. This pertains to the claimed domain state independence in the original MSP method, although the Fabian and Leonhardt (2010) extended protocol largely corrects for domain state effects. Here we describe the optimal workflow for MSP experiments derived from our collection of historic flows from four volcanic edifices: Mt. Etna, Hawaii, the Canary Islands, and the Azores. By comparing the experimental outcome derived from historic flows with known paleointensities we found that technically acceptable experiments may yield overestimates, correct determinations, as well as underestimates of the paleofield. The so-called "ARM test" (de Groot et al., 2012) can distinguish between those three options. Based on TRM and ARM being analogues, this test compares ARM acquisition curves of sister samples before and after heating to the MSP experiment temperature. Simulated paleointensity experiments following this workflow consistently deliver the correct answer (Monster et al., submitted).

  3. Pressure-volume-temperature gauging method experiment using liquid nitrogen under microgravity condition of parabolic flight

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Man Su; Park, Hana; Yoo, Don Gyu; Jeong, Sang Kwon [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, KAIST, Daejeon (Korea, Republic of); Jung, Young Suk [Launcher Systems Development Team, Korea Aerospace Research Institute, Daejeon (Korea, Republic of)

    2014-06-15

    Measuring an exact amount of remaining cryogenic liquid propellant under microgravity condition is one of the important issues of rocket vehicle. A Pressure-Volume-Temperature (PVT) gauging method is attractive due to its minimal additional hardware and simple gauging process. In this paper, PVT gauging method using liquid nitrogen is investigated under microgravity condition with parabolic flight. A 9.2 litre metal cryogenic liquid storage tank containing approximately 30% of liquid nitrogen is pressurized by ambient temperature helium gas. During microgravity condition, the inside of the liquid tank becomes near-isothermal condition within 1 K difference indicated by 6 silicon diode sensors vertically distributed in the middle of the liquid tank. Helium injection with higher mass flow rate after 10 seconds of the waiting time results in successful measurements of helium partial pressure in the tank. Average liquid volume measurement error is within 11% of the whole liquid tank volume and standard deviation of errors is 11.9. As a result, the applicability of PVT gauging method to liquid.

  4. Pressure-volume-temperature gauging method experiment using liquid nitrogen under microgravity condition of parabolic flight

    International Nuclear Information System (INIS)

    Seo, Man Su; Park, Hana; Yoo, Don Gyu; Jeong, Sang Kwon; Jung, Young Suk

    2014-01-01

    Measuring an exact amount of remaining cryogenic liquid propellant under microgravity condition is one of the important issues of rocket vehicle. A Pressure-Volume-Temperature (PVT) gauging method is attractive due to its minimal additional hardware and simple gauging process. In this paper, PVT gauging method using liquid nitrogen is investigated under microgravity condition with parabolic flight. A 9.2 litre metal cryogenic liquid storage tank containing approximately 30% of liquid nitrogen is pressurized by ambient temperature helium gas. During microgravity condition, the inside of the liquid tank becomes near-isothermal condition within 1 K difference indicated by 6 silicon diode sensors vertically distributed in the middle of the liquid tank. Helium injection with higher mass flow rate after 10 seconds of the waiting time results in successful measurements of helium partial pressure in the tank. Average liquid volume measurement error is within 11% of the whole liquid tank volume and standard deviation of errors is 11.9. As a result, the applicability of PVT gauging method to liquid

  5. Electrodeposited nitrogen-doped graphene/carbon nanotubes nanocomposite as enhancer for simultaneous and sensitive voltammetric determination of caffeine and vanillin

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Lin; Ding, Yaping, E-mail: wdingyp@sina.com; Jiang, Feng; Li, Li; Mo, Fan

    2014-06-23

    Graphical abstract: A nanocomposite of nitrogen-doped graphene (NGR) and nitrogen-doped carbon nanotubes (NCNTs) was first modified onto an electrode through electrodeposition method and employed to sensitively detect caffeine and vanillin simultaneously for the first time. - Highlights: • The first electrochemical sensor for caffeine (CAF) and vanillin (VAN). • NGR–NCNTs was modified through electrodeposition for the first time. • The sensor was qualified for real sample determination with satisfactory results. - Abstract: A nitrogen-doped graphene/carbon nanotubes (NGR–NCNTs) nanocomposite was employed into the study of the electrochemical sensor via electrodeposition for the first time. The morphology and structure of NGR–NCNTs nanocomposite were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Meanwhile, the electrochemical performance of the glassy carbon electrode (GCE) modified with electrodeposited NGR–NCNTs (ENGR–NCNTs/GCE) towards caffeine (CAF) and vanillin (VAN) determination was demonstrated by cyclic voltammetry (CV) and square wave voltammetry (SWV). Under optimal condition, ENGR–NCNTs/GCE exhibited a wide linearity of 0.06–50 μM for CAF and 0.01–10 μM for VAN with detection limits of 0.02 μM and 3.3 × 10{sup −3} μM, respectively. Furthermore, the application of the proposed sensor in food products was proven to be practical and reliable. The desirable results show that the ENGR–NCNTs nanocomposite has promising potential in electrocatalytic biosensor application.

  6. Electrodeposited nitrogen-doped graphene/carbon nanotubes nanocomposite as enhancer for simultaneous and sensitive voltammetric determination of caffeine and vanillin

    International Nuclear Information System (INIS)

    Jiang, Lin; Ding, Yaping; Jiang, Feng; Li, Li; Mo, Fan

    2014-01-01

    Graphical abstract: A nanocomposite of nitrogen-doped graphene (NGR) and nitrogen-doped carbon nanotubes (NCNTs) was first modified onto an electrode through electrodeposition method and employed to sensitively detect caffeine and vanillin simultaneously for the first time. - Highlights: • The first electrochemical sensor for caffeine (CAF) and vanillin (VAN). • NGR–NCNTs was modified through electrodeposition for the first time. • The sensor was qualified for real sample determination with satisfactory results. - Abstract: A nitrogen-doped graphene/carbon nanotubes (NGR–NCNTs) nanocomposite was employed into the study of the electrochemical sensor via electrodeposition for the first time. The morphology and structure of NGR–NCNTs nanocomposite were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Meanwhile, the electrochemical performance of the glassy carbon electrode (GCE) modified with electrodeposited NGR–NCNTs (ENGR–NCNTs/GCE) towards caffeine (CAF) and vanillin (VAN) determination was demonstrated by cyclic voltammetry (CV) and square wave voltammetry (SWV). Under optimal condition, ENGR–NCNTs/GCE exhibited a wide linearity of 0.06–50 μM for CAF and 0.01–10 μM for VAN with detection limits of 0.02 μM and 3.3 × 10 −3 μM, respectively. Furthermore, the application of the proposed sensor in food products was proven to be practical and reliable. The desirable results show that the ENGR–NCNTs nanocomposite has promising potential in electrocatalytic biosensor application

  7. The study on effect of zeolite on nitrogen use efficiency of corn by 15N-isotope dilution method

    International Nuclear Information System (INIS)

    Li Changhong; Li Huaxing; Zhang Xinming; Liu Yuanjin

    2002-01-01

    A pot experiment was carried out to study the effect of natural zeolite on nitrogen use efficiency of corn by using 15 N-isotope dilution method. The results showed that application of zeolite could improve the corn growth and enhance the biomass of the corn seedling. By using zeolite, nitrogen use efficiency (NUE) of corn was increased by 23.2%-33.1% as compared with no-zeolite treatment; and the residual nitrogen has no significant difference between zeolite treatment and no-zeolite treatment

  8. New method of reducing emission of nitrogen oxides at coal-dust burning thermal power plants in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.

    1987-05-01

    New method of suppressing nitrogen oxide formation in the combustion process makes use of SGR- or PM-burners in the combustion chamber, augmented with auxiliary burners positioned higher in the chamber for secondary fuel with insufficient air and nozzles above the latter for tertiary air. A description of laboratory experiments on the reduction of nitrogen oxides using the above burner configuration as well as a description of the reaction process taking place during combustion are presented. Results of industrial testing of the three-stage combustion of high-nitrogen Australian black coal in a cylindrical combustion chamber developed by Hitachi-Zosen are presented.

  9. Attempt at estimating the rate of symbiotic fixation of nitrogen in the Lupine by natural isotopic tracing (/sup 15/N)

    Energy Technology Data Exchange (ETDEWEB)

    Amarger, Noelle [INRA Centre de Recherches de Dijon, 21 (France). Lab. de Microbiologie des Sols; Mariotti, Andre; Mariotti, Francoise [Paris-6 Univ., 75 (France)

    1977-06-06

    The rate of nitrogen fixation by a Rhizobium-Leguminous plant pair has been determined by natural isotopic tracing (/sup 15/N). After determining the isotopic fractionation coefficients between atmospheric nitrogen and plant nitrogen on the one hand (epsilon=-0.9) and nitrogen of the substrate and plant nitrogen on the other hand (epsilon=-1.1), the rate of nitrogen fixation by way of mixed nutrition cultures was calculated. The method is more accurate than standard methods.

  10. Simultaneous determination of nitrogen and phosphorus in cereals using 14 MeV Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Bejarano, R.

    1992-01-01

    A method using 14 MeV neutron activation analysis was developed form non-destructive simultaneous determination of N and P in cereals. The samples were irradiated 5 min. after 0,5 min. decay time. The induced activities were measured using gamma spectrometry with Nal(Tl) well type detector. The accuracy, precision and detection limits obtained are discussed as well as the analytical results for different types of cereals. (Author) 10 refs., 8 tab., 1 fig

  11. Foliar Reflectance and Fluorescence Responses for Plants Under Nitrogen Stress Determined with Active and Passive Systems

    Science.gov (United States)

    Middleton, E. M.; McMurtrey, J. E.; Campbell, P. K. Entcheva; Corp, L. A.; Butcher, L. M.; Chappelle, E. W.

    2003-01-01

    Vegetation productivity is driven by nitrogen (N) availability in soils. Both excessive and low soil N induce physiological changes in plant foliage. In 2001, we examined the use of spectral fluorescence and reflectance measurements to discriminate among plants provided different N fertilizer application rates: 20%, 50%, 100% and 150% of optimal N levels. A suite of optical, fluorescence, and biophysical measurements were collected on leaves from field grown corn (Zea mays L.) and soybean plants (Glycine max L.) grown in pots (greenhouse + ambient sunlight daily). Three types of steady state laser-induced fluorescence measurements were made on adaxial and abaxial surfaces: 1) fluorescence images in four 10 nm bands (blue, green, red, far-red) resulting from broad irradiance excitation; 2) emission spectra (5 nm resolution) produced by excitation at single wavelengths (280,380 or 360, and 532 nm); and 3) excitation spectra (2 nm resolution), with emission wavelengths fixed at wavelengths centered on selected solar Fraunhofer lines (532,607,677 and 745 nm). Two complementary sets of high resolution (less than 2 nm) optical spectra were acquired for both adaxial and abaxial leaf surfaces: 1) optical properties (350-2500 nm) for reflectance, transmittance, and absorptance; and 2) reflectance spectra (500-1000 nm) acquired with and without a short pass filter at 665 nm to determine the fluorescence contribution to apparent reflectance in the 650-750 spectrum, especially at the 685 and 740 nm chlorophyll fluorescence (ChIF) peaks. The strongest relationships between foliar chemistry and optical properties were demonstrated for C/N content and two optical parameters associated with the red edge inflection point. Select optical properties and ChIF parameters were highly correlated for both species. A significant contribution of ChIF to apparent reflectance was observed, averaging 10-25% at 685 nm and 2 - 6% at 740 nm over all N treatments. Discrimination of N treatment

  12. Effect of Irrigation Methods, Nitrogen and Phosphorus Fertilizer Rates on Sugar Beet Yield and Quality

    International Nuclear Information System (INIS)

    Janat, M.; Abudlkareem, J.

    2007-01-01

    The experiment was conducted at a research station near Adlib. Two irrigation methods, sprinkler irrigation and drip fertigation, two phosphorus rates and four nitrogen rates 0, 70, 140 and 210 kg N/ha were tested. All N fertilizers were injected for drip irrigation or broadcasted for the sprinkler-irrigated treatments in six equally split applications. Neutron probe Results revealed that the introduction of drip fertigation was not proved to be a water saving relative to sprinkler irrigation. Dry matter production was slightly increased for the drip-fertigated treatments relative to sprinkler irrigated treatments. Nitrogen use efficiency was not improved under drip fertigation relative to that of sprinkler irrigation. Application of phosphorus fertilizer improved sugar beet yield as well as N uptake. No significant differences in sugar beet yield were observed due to the application of N fertilizer under drip fertigation. On the other hand, there was a trend toward increasing sugar beet yield grown under sprinkler irrigation. Drip fertigation had no negative effects on sugar content and other related properties, furthermore some of those properties were enhanced due to the employment of drip fertigation. Field water-use efficiency followed a similar trend and was increased under sprinkler irrigation relative to drip-fertigation for sugar beet yield parameter.

  13. Staged combustion - main method for suppressing nitrogen oxides in pulverized-coal fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R. (Vsesoyuznyi Teplotekhnicheskii Institut (USSR))

    1989-08-01

    Describes principles behind staged combustion, which is based on organizing furnace operations so that only part of the air from the fuel is taken into the furnace. The remaining air, which is needed for combustion, is fed as a tertiary blast jet into the intermediate flame zone. Following inflammation and combustion of the volatile matter, the oxygen concentration in the flame drops sharply causing a retardation of the oxidation reactions forming NO and an intensification of the reactions causing the nitrogen-containing radicals NH{sub i} and CN to be converted into N{sub 2}. When the reducing agents CO, H{sub 2} and CH{sub 4} are present in certain flame zones, even the nitrogen oxide is reduced to N{sub 2}. The NO concentrations in the flame are reduced until the jet of tertiary air is introduced. Discusses with reference to practice in the USA and Western Europe how to achieve maximum effect of this method for different types of boiler and presents the results of observations of the introduction of staged combustion to the BKZ-210-140 boiler burning Kuznetsk gassy coal. 5 refs.

  14. A Generalizable Top-Down Nanostructuring Method of Bulk Oxides: Sequential Oxygen-Nitrogen Exchange Reaction.

    Science.gov (United States)

    Lee, Lanlee; Kang, Byungwuk; Han, Suyoung; Kim, Hee-Eun; Lee, Moo Dong; Bang, Jin Ho

    2018-05-27

    A thermal reaction route that induces grain fracture instead of grain growth is devised and developed as a top-down approach to prepare nanostructured oxides from bulk solids. This novel synthesis approach, referred to as the sequential oxygen-nitrogen exchange (SONE) reaction, exploits the reversible anion exchange between oxygen and nitrogen in oxides that is driven by a simple two-step thermal treatment in ammonia and air. Internal stress developed by significant structural rearrangement via the formation of (oxy)nitride and the creation of oxygen vacancies and their subsequent combination into nanopores transforms bulk solid oxides into nanostructured oxides. The SONE reaction can be applicable to most transition metal oxides, and when utilized in a lithium-ion battery, the produced nanostructured materials are superior to their bulk counterparts and even comparable to those produced by conventional bottom-up approaches. Given its simplicity and scalability, this synthesis method could open a new avenue to the development of high-performance nanostructured electrode materials that can meet the industrial demand of cost-effectiveness for mass production. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. System and method for controlling ammonia levels in a selective catalytic reduction catalyst using a nitrogen oxide sensor

    Science.gov (United States)

    None

    2017-07-25

    A system according to the principles of the present disclosure includes an air/fuel ratio determination module and an emission level determination module. The air/fuel ratio determination module determines an air/fuel ratio based on input from an air/fuel ratio sensor positioned downstream from a three-way catalyst that is positioned upstream from a selective catalytic reduction (SCR) catalyst. The emission level determination module selects one of a predetermined value and an input based on the air/fuel ratio. The input is received from a nitrogen oxide sensor positioned downstream from the three-way catalyst. The emission level determination module determines an ammonia level based on the one of the predetermined value and the input received from the nitrogen oxide sensor.

  16. Synthesis of nitrogen-doped and amino acid-functionalized graphene quantum dots from glycine, and their application to the fluorometric determination of ferric ion

    International Nuclear Information System (INIS)

    Li, Linbo; Li, Lin; Wang, Chao; Liu, Kangyu; Zhu, Ruohua; Qiang, Hong; Lin, Yuqing

    2015-01-01

    We report on a single-step thermolysis strategy to prepare highly luminescent nitrogen-doped and amino acid-functionalized graphene quantum dots (NA-GQDs) by using glycine as both carbon and nitrogen source. The NA-GQDs display an excitation wavelength-dependent fluorescence with maximum excitation and emission wavelengths of 380 and 450 nm, respectively, and a quantum yield of ∼16 %. Fluorescence is quenched by Fe(III) and Hg(II), and the effect was used to develop a method for the determination of Fe(III). Quenching by Fe(III) is attributed to its higher thermodynamic affinity (compared to other transition-metal ions) for the ligands on the GQDs in which nitrogen atoms mainly act as the chelating atoms. A linear relationship was observed between fluorescence intensity and the concentration of Fe(III) over the 0.5 μM to 0.5 mM range. The detection limit is 0.1 μM. (author)

  17. Multivariate analysis and determination of the best indirect selection criteria to genetic improvement the biological nitrogen fixation ability in common bean genotypes (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Golparvar Reza Ahmad

    2012-01-01

    Full Text Available In order to determine the best indirect selection criteria for genetic improvement of biological nitrogen fixation, sixty four common bean genotypes were cultivated in two randomized complete block design. Genotypes were inoculated with bacteria Rhizobium legominosarum biovar Phaseoli isolate L-109 only in one of the experiments. The second experiment was considered as check for the first. Correlation analysis showed positive and highly significant correlation of majority of the traits with percent of nitrogen fixation. Step-wise regression designated that traits percent of total nitrogen of shoot, number of nodule per plant and biological yield accounted for 92.3 percent of variation exist in percent of nitrogen fixation. Path analysis indicated that these traits have direct and positive effect on percent of nitrogen fixation. Hence, these traits are promising indirect selection criteria for genetic improvement of nitrogen fixation capability in common bean genotypes especially in early generations.

  18. solid phase extraction method for selective determination

    African Journals Online (AJOL)

    FATOKI

    determination of phthalate ester plasticizers in rivers and marine water samples. Of the ... samples that receive effluent from industries that use phthalate esters. ... Keywords Phthalates, Plasticizers, Solid Phase Gas Chromatography.

  19. The Determination of Sugars by Chromatographic Method

    OpenAIRE

    Sumartini, Sri; Kantasubrata, Julia

    1992-01-01

    Experiments have been carried out to analyse sugars using TLC and HPLC methods, In the TLC method, separation of sugars was performed on silica plates impregnated with monosodium phosphate and using mixture of ethylacettuel pyridinde/water as an eluent. Whilst in the HPLC method, the use of three column types i.e. diol, RP-18 and modified silica column were tested. The results showed that TLC method was able to measure three sugars i:e. sucrose, glucose and fructose with standard deviations o...

  20. Evaluation of weed control methods on sugar beet (Beta vulgaris L. yield at different levels of nitrogen

    Directory of Open Access Journals (Sweden)

    AliAsghar Chitband

    2017-03-01

    Full Text Available Introduction: Weed competition is one of the major factors which limit sugar beet production in the world. Weed – crop interactions are based on competition for water, nutrients and light and allelopathic effects may also play a small role. In sugar beet weed interference, all these factors are important too, but the light is of prime importance. Due to the fact that a lot of weeds can grow above the sugar beet canopy and reduce the amount of photosynthetic radiation reaching the crop, these weeds are stronger competitors compared to smaller weeds. In much sugar beet growing areas dicot weeds of the families Chenopodiaceae, Asteraceae, Brassicaceae and Polygonaceae are of major importance. The monocots are less important compared to dicot weeds. Competition from uncontrolled annual weeds that emerge within 8 weeks of sowing or within 4 weeks of the crop reaching the two-leaf stage can reduce root yields by 26–100% .Weeds that emerge 8 weeks after sowing, and particularly after the sugar beet plants have eight or more leaves, are less likely to affect yield. Although tractor hoeing and hand labour are still used in many production areas, herbicides have been the primary method of weed control in sugar beet. The effectiveness of pre-emergence residual herbicides decreases with reductions in rainfall or soil wet content. Therefore, less than 10 % of the total sugar beet crop is treated with pre-emergence herbicides. The remaining 90 % depends solely on a selection of post-emergence herbicides to maintain season-long weed control. The major herbicides are phenmedipham, chloridazon, metamitron. Mixtures of post-emergence, broad spectrum herbicides have to be applied to control the wide range of weed species in sugar beet crops. Materials and Methods: To study the effects of weeds control by hand weeding and herbicides combination with two selective herbicides at different levels of nitrogen application on sugar beet yield and quality

  1. Mycotoxin determination using RIA and ELISA methods

    Energy Technology Data Exchange (ETDEWEB)

    Fukal, L; Sova, Z

    1985-12-01

    Experience is summed up of various authors with the determination of some mycotoxins (aflatoxin, ochratoxin A, T-2 toxin, rubratoxin, zearalenon, sterigmatocystine) using radioimmunoassay and enzyme immunoassay. For RIA purposes, tritium or sometimes iodine 125 is frequently used for labelling mycotoxins. Mycotoxins do not show immunogenic properties and must thus be conjugated with a high-molecular compound (serum albumin, polylysine) prior to immunozation. Factors are discussed making mycotoxin determination in foods difficult. Specificity of the obtained antisera is total between the individual mycotoxin groups while cross reactions are always recorded within the groups. RIA makes it possible to determine down to 200 pg (labelled with /sup 3/H) or 5 pg (labelled with /sup 125/I) of mycotoxins in a standard solution. In addition to high sensitivity and specificity, immunoassays of mycotoxins minimize the quantities of samples and solvents needed for extraction. Large series of samples can be processed using automatic analyzers. ELISA generally is more advantageous than RIA.

  2. Direct methods for determining internal contamination

    International Nuclear Information System (INIS)

    Melandri, C.

    1985-01-01

    The direct methods of investigation on body content of radionuclides emitting gamma rays with energies higher than 100 KeV are described. After a short review of the earlier methods, the main technical charateristics of the present used whole body counters and counting geometries are described together with the calibration methods. Qualitative and quantitative data interpretation are also briefly discussed. The minimum detectable activity and the Derived Investigation Levels at different times from the intake both by ingestion or by inhalation as aerosol are finally compared for some radionuclides of great importance in the health physic survey

  3. An electrochemical procedure coupled with a Schiff base method; application to electroorganic synthesis of new nitrogen-containing heterocycles

    International Nuclear Information System (INIS)

    Dowlati, Bahram; Othman, Mohamed Rozali

    2013-01-01

    The synthesis of Nitrogen-containing heterocycles has been achieved using chemical and electrochemical methods, respectively. The direct chemical synthesis of nucleophiles proceeds through the Schiff base chemical reaction. This procedure offers an alternate reaction between dicarbonyl compounds and diamines leads to the formation of products. The results indicate that the Schiff base chemical method for synthesis of the product has successfully performed in excellent overall yield. In the electrochemical step, a series of Nitrogen-containing compounds were electrosynthesized. Various parameters such as the applied potential, pH of the electrolytic solution, cell configuration and also purification techniques, were carried out to optimize the yields of corresponding products. New Nitrogen-containing heterocycle derivatives were synthesized using an electrochemical procedure coupled with a Schiff base as a facile, efficient and practical method. The products have been characterized after purification by IR, 1 H NMR, 13 C NMR and ESI-MS 2

  4. Spectrophotometric Methods for the Determination of Ketoconazole ...

    African Journals Online (AJOL)

    HP

    The second method (B) involved potassium permanganate as oxidant and methylene blue ... oxidation or complexation with metal ions. Some ... oxidation reaction of the drug using excess ... volume of water and then made up to 100 ml in a.

  5. A simple method for α determination

    International Nuclear Information System (INIS)

    Ho Manh Dung; Seung Yeon Cho

    2003-01-01

    The a term is a primary parameter that is used to indicate the deviation of the epithermal neutron distribution in the k 0 -standardization method of neutron activation analysis, k 0 -NAA. The calculation of a using a mathematical procedure is a challenge for some researchers. The calculation of a by the 'bare-triple monitor' method is possible using the dedicated commercial software KAYZERO R /SOLCOI R . However, when this software is not available in the laboratory it is possible to carry out the calculation of a applying a simple iterative linear regression using any spreadsheets. This approach is described. The experimental data used in the example were obtained by the irradiation of a set of suitable monitors in the NAA no.1 irradiation channel of the HANARO research reactor (KAERI, Korea). The results obtained by this iterative linear regression method agree well with the results calculated by the validated mathematical method. (author)

  6. Comparison of fractionation methods for nitrogen and starch in maize and grass silages

    NARCIS (Netherlands)

    Ali, M; de Jonge, L H; Cone, J W; van Duinkerken, G; Blok, M C; Bruinenberg, M H; Hendriks, W H

    2016-01-01

    In in situ nylon bag technique, many feed evaluation systems use a washing machine method (WMM) to determine the washout (W) fraction and to wash the rumen incubated nylon bags. As this method has some disadvantages, an alternate modified method (MM) was recently introduced. The aim of this study

  7. Fluoride method for silicon determination i silicovadium

    International Nuclear Information System (INIS)

    Komarnitskaya, N.N.; Sergeev, K.I.; Shamraj, Z.Ya.

    1977-01-01

    The method used was based on formation of a silicon-potassium fluoride-sodium sediment in strongly acid medium in the presence of excess potassium chloride which decreased the sediment solubility. The sediment was dissolved in hot water to titrate the resultant hydrofluoric acid with a caustic potash solution in the presence of phenolphthalein. Gravity hydrochloric and volumetric fluoride methods were used to compare the results of silicon estimation

  8. Determination of N-containing halogenated natural products using gas chromatography in combination of a nitrogen-phosphorus-detector

    Energy Technology Data Exchange (ETDEWEB)

    Melcher, J.; Vetter, W. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Lebensmittelchemie

    2004-09-15

    In the last few years several nonpolar halogenated natural products (HNPs) such as Q1, MHC-1, BC-2, BC-3, BC-10 were detected at elevated concentrations in marine biota samples. In addition, there are still some abundant peaks of halogenated compounds frequently found in the gas chromatograms of many marine samples which have not yet been identified. Some of the known halogenated natural products (Q1, HDBPs including BC-10, bromoindoles) contain N-heterocyclic backbones. Since nitrogen is scarcely found in anthropogenic halogenated compounds, the detection of N-containing halogenated substances may be used as a first indicator for the presence of HNPs in a sample extract. In the presented method we studied the suitability of a nitrogen phosphorous detector (NPD) for quantification of Q1 and the detection of Ncontaining compounds in marine biota. Analyses were accompanied with GC/ECD analyses.

  9. Nitrogen doped silicon-carbon multilayer protective coatings on carbon obtained by thermionic vacuum arc (TVA) method

    Science.gov (United States)

    Ciupinǎ, Victor; Vasile, Eugeniu; Porosnicu, Corneliu; Vladoiu, Rodica; Mandes, Aurelia; Dinca, Virginia; Nicolescu, Virginia; Manu, Radu; Dinca, Paul; Zaharia, Agripina

    2018-02-01

    To obtain protective nitrogen doped Si-C multilayer coatings on carbon, used to improve the oxidation resistance of carbon, was used TVA method. The initial carbon layer has been deposed on a silicon substrate in the absence of nitrogen, and then a 3nm Si thin film to cover carbon layer was deposed. Further, seven Si and C layers were alternatively deposed in the presence of nitrogen ions. In order to form silicon carbide at the interface between silicon and carbon layers, all carbon, silicon and nitrogen ions energy has increased up to 150eV. The characterization of microstructure and electrical properties of as-prepared N-Si-C multilayer structures were done using Transmission Electron Microscopy (TEM, STEM) techniques, Thermal Desorption Spectroscopy (TDS) and electrical measurements. The retention of oxygen in the protective layer of N-Si-C is due to the following phenomena: (a) The reaction between oxygen and silicon carbide resulting in silicon oxide and carbon dioxide; (b) The reaction involving oxygen, nitrogen and silicon resulting silicon oxinitride with a variable composition; (c) Nitrogen acts as a trapping barrier for oxygen. To perform electrical measurements, ohmic contacts were attached on the N-Si-C samples. Electrical conductivity was measured in constant current mode. To explain the temperature behavior of electrical conductivity we assumed a thermally activated electric transport mechanism.

  10. Graphical Method for Determining Projectile Trajectory

    Science.gov (United States)

    Moore, J. C.; Baker, J. C.; Franzel, L.; McMahon, D.; Songer, D.

    2010-01-01

    We present a nontrigonometric graphical method for predicting the trajectory of a projectile when the angle and initial velocity are known. Students enrolled in a general education conceptual physics course typically have weak backgrounds in trigonometry, making inaccessible the standard analytical calculation of projectile range. Furthermore,…

  11. Radiological in vivo method of determination

    International Nuclear Information System (INIS)

    1980-01-01

    A method is described for the radiological localization of an infected area in the body, with the aid of In 111 -chelate and 8-hydroxychinoline. The chelate accumulates in the infected area which is then localised by means of external imaging processes. (Th.P.)

  12. Methods to classify maize cultivars in use efficiency and response to nitrogen

    Directory of Open Access Journals (Sweden)

    Cleiton Lacerda Godoy

    2013-10-01

    Full Text Available n plant breeding programs that aim to obtain cultivars with nitrogen (N use efficiency, the focus is on methods of selection and experimental procedures that present low cost, fast response, high repeatability, and can be applied to a large number of cultivars. Thus, the objectives of this study were to classify maize cultivars regarding their use efficiency and response to N in a breeding program, and to validate the methodology with contrasting doses of the nutrient. The experimental design was a randomized block with the treatments arranged in a split-plot scheme with three replicates and five N doses (0, 30, 60, 120 and 200 kg ha-1 in the plots, and six cultivars in subplots. We compared a method examining the efficiency and response (ER with two contrasting doses of N. After that, the analysis of variance, mean comparison and regression analysis were performed. In conclusion, the method of the use efficiency and response based on two N levels classifies the cultivars in the same way as the regression analysis, and it is appropriate in plant breeding routine. Thus, it is necessary to identify the levels of N required to discriminate maize cultivars in conditions of low and high N availability in plant breeding programs that aim to obtain efficient and responsive cultivars. Moreover, the analysis of the interaction genotype x environment at experiments with contrasting doses is always required, even when the interaction is not significant.

  13. Sediment diffusion method improves wastewater nitrogen removal in the receiving lake sediments.

    Science.gov (United States)

    Aalto, Sanni L; Saarenheimo, Jatta; Ropponen, Janne; Juntunen, Janne; Rissanen, Antti J; Tiirola, Marja

    2018-07-01

    Sediment microbes have a great potential to transform reactive N to harmless N 2 , thus decreasing wastewater nitrogen load into aquatic ecosystems. Here, we examined if spatial allocation of the wastewater discharge by a specially constructed sediment diffuser pipe system enhanced the microbial nitrate reduction processes. Full-scale experiments were set on two Finnish lake sites, Keuruu and Petäjävesi, and effects on the nitrate removal processes were studied using the stable isotope pairing technique. All nitrate reduction rates followed nitrate concentrations, being highest at the wastewater-influenced sampling points. Complete denitrification with N 2 as an end-product was the main nitrate reduction process, indicating that the high nitrate and organic matter concentrations of wastewater did not promote nitrous oxide (N 2 O) production (truncated denitrification) or ammonification (dissimilatory nitrate reduction to ammonium; DNRA). Using 3D simulation, we demonstrated that the sediment diffusion method enhanced the contact time and amount of wastewater near the sediment surface especially in spring and in autumn, altering organic matter concentration and oxygen levels, and increasing the denitrification capacity of the sediment. We estimated that natural denitrification potentially removed 3-10% of discharged wastewater nitrate in the 33 ha study area of Keuruu, and the sediment diffusion method increased this areal denitrification capacity on average 45%. Overall, our results indicate that sediment diffusion method can supplement wastewater treatment plant (WWTP) nitrate removal without enhancing alternative harmful processes. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Technological methods of reducing the emissions of nitrogen oxides during the combustion of solid fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.

    1981-01-01

    For protecting the atmosphere from emissions of toxic NO /SUB x/ during combustion of fuel in boilers the amount of NO /SUB x/ can be reduced in the process of combustion, or the flue gases (FG) from the boiler can be cleaned. The latter method is bound up with the necessity for treatment of a large quantity of FG with a comparatively low concentration in them of nitrogen oxides, chemically stable and poorly soluble in water. The problem is complicated by the presence in the FG of SO /SUB x/, O/sub 2/, and solid particles. The method of purifying the FG is complicated and requires large capital investment and operating expenses. By laboratory studies in the All-Union Institute of Heat Engineering im. F.E. Dzerzhinskiy (VTI) it was established that thermal NO /SUB x/ is formed at a combustion temperature greater than or equal to 1550 /sup 0/C and that the 0/sub 2/ concentration and considerably less the temperature strongly affect NO /SUB x/ formation. On the basis of laboratory studies and industrial tests in the VTI, methods of reducing NO /SUB x/ emissions by large-scale boilers are recommended.

  15. Evaluation of creep-fatigue life prediction methods for low-carbon/nitrogen-added SUS316

    International Nuclear Information System (INIS)

    Takahashi, Yukio

    1998-01-01

    Low-carbon/medium nitrogen 316 stainless steel called 316FR is a principal candidate for the high-temperature structural materials of a demonstration fast reactor plant. Because creep-fatigue damage is a dominant failure mechanism of the high-temperature materials subjected to thermal cycles, it is important to establish a reliable creep-fatigue life prediction method for this steel. Long-term creep tests and strain-controlled creep-fatigue tests have been conducted at various conditions for two different heats of the steel. In the constant load creep tests, both materials showed similar creep rupture strength but different ductility. The material with lower ductility exhibited shorter life under creep-fatigue loading conditions and correlation of creep-fatigue life with rupture ductility, rather than rupture strength, was made clear. Two kinds of creep-fatigue life prediction methods, i.e. time fraction rule and ductility exhaustion method were applied to predict the creep-fatigue life. Accurate description of stress relaxation behavior was achieved by an addition of 'viscous' strain to conventional creep strain and only the latter of which was assumed to contribute to creep damage in the application of ductility exhaustion method. The current version of the ductility exhaustion method was found to have very good accuracy in creep-fatigue life prediction, while the time fraction rule overpredicted creep-fatigue life as large as a factor of 30. To make a reliable estimation of the creep damage in actual components, use of ductility exhaustion method is strongly recommended. (author)

  16. METHODS FOR THE DETERMINATION OF TOTAL ORGANIC ...

    Science.gov (United States)

    Organic matter in soils and sediments is widely distributed over the earth's surface occurring in almost all terrestrial and aquatic environments (Schnitzer, 1978). Soils and sediments contain a large variety of organic materials ranging from simple sugars and carbohydrates to the more complex proteins, fats, waxes, and organic acids. Important characteristics of the organic matter include their ability to: form water-soluble and water- insoluble complexes with metal ions and hydrous oxides; interact with clay minerals and bind particles together; sorb and desorb both naturally-occurring and anthropogenically-introduced organic compounds; absorb and release plant nutrients; and hold water in the soil environment. As a result of these characteristics, the determination of total organic carbon (a measure of one of the chemical components of organic matter that is often used as an indicator of its presence in a soil or sediment) is an essential part of any site characterization since its presence or absence can markedly influence how chemicals will react in the soil or sediment. Soil and sediment total organic carbon (TOC) determinations are typically requested with contaminant analyses as part of an ecological risk assessment data package. TOC contents may be used qualitatively to assess the nature of the sampling location (e.g., was it a depositional area) or may be used to normalize portions of the analytical chemistry data set (e.g., equilibrium partitioning).

  17. DETERMINING THE OPTIMAL AMOUNT OF NITROGEN TO APPLY TO CORN USING THE BOX-COX FUNCTIONAL FORM

    OpenAIRE

    Tauer, Loren W.

    2000-01-01

    A Box-Cox functional form was estimated from corn-nitrogen data previously used to report optimal nitrogen use from a quadratic production function. Results suggest that less nitrogen should be app1ie.d than recommended using the quadratic function, but with more nitrogen being applied if poor growing conditions are expected.

  18. Method and means for determining heat quantities

    Energy Technology Data Exchange (ETDEWEB)

    Waasdorp, G G; de Jong, J J; Bijl, A

    1965-08-24

    To determine the quantity of potential heat W that has flowed past a certain point in a certain time, the velocity of the combustible Q, the temperature T, and the specific gravity YDTU are measured, and these values are transmitted to a computer which automatically calculates the quantity: ..pi..EQUATION/sup -/ in which delta T is the difference between the combustible temperature T and a reference temperature, and in which the relation f(YDTU, delta T) represents the heat of combustion as a function of the quantities YDTU and delta T and possibly other properties of the combustible. Alternatively the quantity: ..pi..EQUATION/sup -/ may be measured; here the quantities have the same meaning as above.

  19. Methods to determine iodine plate-out

    International Nuclear Information System (INIS)

    Hougaard, H.; Solgaard, P.; Zak, W.

    1986-03-01

    A literature study on iodines behaviour after release from irradiated fuel rods and a detailed dscription of the ventilation system in the hot cell facility form the basis of chosen conditions for some preliminary experiments using non-radioactive iodine. The conclusion states that the system is well suited for the purpose as is the method of sampling from the surface of the ventilation duct, while the releasing technique and the chemical analysis has to be further developed, neutron activation analysis being most promising. (author)

  20. Determination of mycroplasmic contamination by radiometric method

    International Nuclear Information System (INIS)

    Khashimova, Z.S.

    2004-01-01

    Full text: Some species of mycoplasmas are pathogenic for man, animals and plants. The problem of mycoplasmic contamination of cultivated cells used in biotechnology for producing of monoclonal antibodies and vaccines is very actual. The plasmatic membrane of mycoplasmas, which does not differ on its structural organization from a membrane of eucariotic cells, takes part in formation of strong surface antigens. Taking into account this fact, it has been investigated mycoplasmic contamination of several kinds of cotton seeds, myelome cells XAg8.653, and hybridoma cells producing monoclonal antibodies to cotton membrane proteins. Mycoplasmic contamination was determined by hybridization of DNA of investigated objects with recombinant plasmids containing mycoplasmas DNA fragments. DNA was isolated from 5 kinds of cotton seedling, cellular cultures and hybridomas according to standard protocols. DNA was denaturated, neutralized and a reaction mix was transferred to nitrocellulose filter. Than filters were hybridizated with universal plasmid sounds namely pMg16 and pAl32, which contained the mycoplasma genomic fragment. These sounds were constructed in the Institute of Cytology of Russian Academy of Science by Borhsenius S.N. at al. [1] and kindly given us for our work. pMg16 and pAl32 were preliminary marked by 32 P - ATP (nick - translation). Hybridization was carried out within night. Filters were washed and placed for radioautography at - 70 o C for 24h. Sensitivity of 32 P - labeled probes in reaction was 1ng of mycoplasmas DNA. It was shown, that only one kind of cotton seeds was not contaminated by mycoplasmas, and hybridoma and myeloma cells was not contaminated. Thus, the presence of mycoplasmas in different objects may be determined using DNA hybridization. This work was supported by the Center of Science and Technology RU (4F No 419)

  1. Trace water vapor determination in nitrogen and corrosive gases using infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, L.H.; Niemczyk, T.M. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Chemistry; Stallard, B.R.; Garcia, M.J. [Sandia National Labs., Albuquerque, NM (United States)

    1997-06-01

    The generation of particles in gas handling systems as a result of corrosion is a major concern in the microelectronics industry. The corrosion can be caused by the presence of trace quantities of water in corrosive gases such as HCl or HBr. FTIR spectroscopy has been shown to be a method that can be made compatible with corrosive gases and is capable of detecting low ppb levels of water vapor. In this report, the application of FTIR spectroscopy combined with classical least squares multivariate calibration to detect trace H{sub 2}O in N{sub 2}, HCl and HBr is discussed. Chapter 2 discusses the gas handling system and instrumentation required to handle corrosive gases. A method of generating a background spectrum useful to the measurements discussed in this report, as well as in other application areas such as gas phase environmental monitoring, is discussed in Chapter 3. Experimental results obtained with the first system are presented in Chapter 4. Those results made it possible to optimize the design options for the construction of a dedicate system for low ppb water vapor determination. These designs options are discussed in Chapter 5. An FTIR prototype accessory was built. In addition, a commercially available evacuable FTIR system was obtained for evaluation. Test results obtained with both systems are discussed in Chapter 6. Experiments dealing with the interaction between H{sub 2}O-HCl and potential improvements to the detection system are discussed in Chapter 7.

  2. Determination of solute descriptors by chromatographic methods

    International Nuclear Information System (INIS)

    Poole, Colin F.; Atapattu, Sanka N.; Poole, Salwa K.; Bell, Andrea K.

    2009-01-01

    The solvation parameter model is now well established as a useful tool for obtaining quantitative structure-property relationships for chemical, biomedical and environmental processes. The model correlates a free-energy related property of a system to six free-energy derived descriptors describing molecular properties. These molecular descriptors are defined as L (gas-liquid partition coefficient on hexadecane at 298 K), V (McGowan's characteristic volume), E (excess molar refraction), S (dipolarity/polarizability), A (hydrogen-bond acidity), and B (hydrogen-bond basicity). McGowan's characteristic volume is trivially calculated from structure and the excess molar refraction can be calculated for liquids from their refractive index and easily estimated for solids. The remaining four descriptors are derived by experiment using (largely) two-phase partitioning, chromatography, and solubility measurements. In this article, the use of gas chromatography, reversed-phase liquid chromatography, micellar electrokinetic chromatography, and two-phase partitioning for determining solute descriptors is described. A large database of experimental retention factors and partition coefficients is constructed after first applying selection tools to remove unreliable experimental values and an optimized collection of varied compounds with descriptor values suitable for calibrating chromatographic systems is presented. These optimized descriptors are demonstrated to be robust and more suitable than other groups of descriptors characterizing the separation properties of chromatographic systems.

  3. Determination of solute descriptors by chromatographic methods.

    Science.gov (United States)

    Poole, Colin F; Atapattu, Sanka N; Poole, Salwa K; Bell, Andrea K

    2009-10-12

    The solvation parameter model is now well established as a useful tool for obtaining quantitative structure-property relationships for chemical, biomedical and environmental processes. The model correlates a free-energy related property of a system to six free-energy derived descriptors describing molecular properties. These molecular descriptors are defined as L (gas-liquid partition coefficient on hexadecane at 298K), V (McGowan's characteristic volume), E (excess molar refraction), S (dipolarity/polarizability), A (hydrogen-bond acidity), and B (hydrogen-bond basicity). McGowan's characteristic volume is trivially calculated from structure and the excess molar refraction can be calculated for liquids from their refractive index and easily estimated for solids. The remaining four descriptors are derived by experiment using (largely) two-phase partitioning, chromatography, and solubility measurements. In this article, the use of gas chromatography, reversed-phase liquid chromatography, micellar electrokinetic chromatography, and two-phase partitioning for determining solute descriptors is described. A large database of experimental retention factors and partition coefficients is constructed after first applying selection tools to remove unreliable experimental values and an optimized collection of varied compounds with descriptor values suitable for calibrating chromatographic systems is presented. These optimized descriptors are demonstrated to be robust and more suitable than other groups of descriptors characterizing the separation properties of chromatographic systems.

  4. High-temperature thermodynamic activities of zirconium in platinum alloys determined by nitrogen-nitride equilibria

    International Nuclear Information System (INIS)

    Goodman, D.A.

    1980-05-01

    A high-temperature nitrogen-nitride equilibrium apparatus is constructed for the study of alloy thermodynamics to 2300 0 C. Zirconium-platinum alloys are studied by means of the reaction 9ZrN + 11Pt → Zr 9 Pt 11 + 9/2 N 2 . Carful attention is paid to the problems of diffusion-limited reaction and ternary phase formation. The results of this study are and a/sub Zr//sup 1985 0 C/ = 2.4 x 10 -4 in Zr 9 Pt 11 ΔG/sub f 1985 0 C/ 0 Zr 9 Pt 11 less than or equal to -16.6 kcal/g atom. These results are in full accord with the valence bond theory developed by Engel and Brewer; this confirms their prediction of an unusual interaction of these alloys

  5. Optical determination and magnetic manipulation of a single nitrogen-vacancy color center in diamond nanocrystal

    International Nuclear Information System (INIS)

    Diep Lai, Ngoc; Zheng, Dingwei; Treussart, François; Roch, Jean-François

    2010-01-01

    The controlled and coherent manipulation of individual quantum systems is fundamental for the development of quantum information processing. The nitrogen-vacancy (NV) color center in diamond is a promising system since its photoluminescence is perfectly stable at room temperature and its electron spin can be optically read out at the individual level. We review here the experiments currently realized in our laboratory concerning the use of a single NV color center as the single photon source and the coherent magnetic manipulation of the electron spin associated with a single NV color center. Furthermore, we demonstrate a nanoscopy experiment based on the saturation absorption effect, which allows to optically pin-point a single NV color center at sub-λ resolution. This offers the possibility to independently address two or multiple magnetically coupled single NV color centers, which is a necessary step towards the realization of a diamond-based quantum computer

  6. A Spectrophotometric Method for the Determination of Ramipril in ...

    African Journals Online (AJOL)

    HP

    Purpose: To develop a simple and cost effective spectrophotometer method for the determination of. ACE inhibitor ramipril in dosage forms. Methods: UV spectrophotometry was used to develop and validate a simple method .... 2003 software.

  7. Comparing Mass Balance and Adjoint-Based 4D-VAR Methods for Inverse Modeling of Nitrogen Dioxide Columns for Nitrogen Oxide Emissions

    Science.gov (United States)

    Cooper, M.; Martin, R.; Henze, D. K.

    2016-12-01

    Nitrogen oxide (NOx ≡ NO + NO2) emission inventories can be improved through top-down constraints provided by inverse modeling of observed nitrogen dioxide (NO2) columns. Here we compare two methods of inverse modeling for emissions of NOx from synthetic NO2 columns generated from known emissions using the GEOS-Chem chemical transport model and its adjoint. We treat the adjoint-based 4D-VAR approach for estimating top-down emissions as a benchmark against which to evaluate variations on the mass balance method. We find that the standard mass balance algorithm can be improved by using an iterative process and using finite difference to calculate the local sensitivity of a change in NO2 columns to a change in emissions, resulting in a factor of two reduction in inversion error. In a simplified case study to recover local emission perturbations, horizontal smearing effects due to NOx transport were better resolved by the adjoint-based approach than by mass balance. For more complex emission changes that reflect real world scenarios, the iterative finite difference mass balance and adjoint methods produce similar top-down inventories when inverting hourly synthetic observations, both reducing the a priori error by factors of 3-4. Inversions of data sets that simulate satellite observations from low Earth and geostationary orbits also indicate that both the mass balance and adjoint inversions produce similar results, reducing a priori error by a factor of 3. As the iterative finite difference mass balance method provides similar accuracy as the adjoint-based 4D-VAR method, it offers the ability to efficiently estimate top-down emissions using models that do not have an adjoint.

  8. Biological nitrogen fixation in Crotalaria species estimated using the 15N isotope dilution method

    International Nuclear Information System (INIS)

    Samba, R.T.; Neyra, M.; Gueye, M.; Sylla, S.N.; Ndoye, I.; Dreyfus, B.

    2002-01-01

    Growing in Senegal by using 15 N direct isotope dilution technique. Two non-fixing plants, Senna obtusifolia and Senna occidentalis served as reference plants. The amount of nitrogen fixed two months after planting was obtained using the average of the two reference plants. The atom % 15 N excess in the Crotalaria species was significantly lower than that of the reference plants, indicating that significant nitrogen fixation occurred in the three plants. Significant differences were observed between the Crotalaria species; C. ochroleuca yielded more dry matter weight and total nitrogen than did C. perrottetti and C. retusa. The % nitrogen derived from atmosphere (%Ndfa) in leaves and stems was also higher in C. ochroleuca. There was no significant difference in %Ndfa in the whole plant between the three Crotalaria species (47% to 53%). In contrast, interspecific variability was observed based on the %Ndfa. C. ochroleuca significantly exhibited the higher amount of total nitrogen fixed, equivalent to 83 kg of nitrogen fixed per hectare. Based on these data, it was concluded that C. ochroleuca could be used in multiple cropping systems in Senegal for making more nitrogen available to other plants. (author)

  9. Modern Geometric Methods of Distance Determination

    Science.gov (United States)

    Thévenin, Frédéric; Falanga, Maurizio; Kuo, Cheng Yu; Pietrzyński, Grzegorz; Yamaguchi, Masaki

    2017-11-01

    Building a 3D picture of the Universe at any distance is one of the major challenges in astronomy, from the nearby Solar System to distant Quasars and galaxies. This goal has forced astronomers to develop techniques to estimate or to measure the distance of point sources on the sky. While most distance estimates used since the beginning of the 20th century are based on our understanding of the physics of objects of the Universe: stars, galaxies, QSOs, the direct measures of distances are based on the geometric methods as developed in ancient Greece: the parallax, which has been applied to stars for the first time in the mid-19th century. In this review, different techniques of geometrical astrometry applied to various stellar and cosmological (Megamaser) objects are presented. They consist in parallax measurements from ground based equipment or from space missions, but also in the study of binary stars or, as we shall see, of binary systems in distant extragalactic sources using radio telescopes. The Gaia mission will be presented in the context of stellar physics and galactic structure, because this key space mission in astronomy will bring a breakthrough in our understanding of stars, galaxies and the Universe in their nature and evolution with time. Measuring the distance to a star is the starting point for an unbiased description of its physics and the estimate of its fundamental parameters like its age. Applying these studies to candles such as the Cepheids will impact our large distance studies and calibration of other candles. The text is constructed as follows: introducing the parallax concept and measurement, we shall present briefly the Gaia satellite which will be the future base catalogue of stellar astronomy in the near future. Cepheids will be discussed just after to demonstrate the state of the art in distance measurements in the Universe with these variable stars, with the objective of 1% of error in distances that could be applied to our closest

  10. Assessment of external heat transfer coefficient during oocyte vitrification in liquid and slush nitrogen using numerical simulations to determine cooling rates.

    Science.gov (United States)

    Santos, M V; Sansinena, M; Zaritzky, N; Chirife, J

    2012-01-01

    In oocyte vitrification, plunging directly into liquid nitrogen favor film boiling and strong nitrogen vaporization. A survey of literature values of heat transfer coefficients (h) for film boiling of small metal objects with different geometries plunged in liquid nitrogen revealed values between 125 to 1000 W per per square m per K. These h values were used in a numerical simulation of cooling rates of two oocyte vitrification devices (open-pulled straw and Cryotop), plunged in liquid and slush nitrogen conditions. Heat conduction equation with convective boundary condition was considered a linear mathematical problem and was solved using the finite element method applying the variational formulation. COMSOL Multiphysics was used to simulate the cooling process of the systems. Predicted cooling rates for OPS and Cryotop when cooled at -196 degree C (liquid nitrogen) or -207 degree C (average for slush nitrogen) for heat transfer coefficients estimated to be representative of film boiling, indicated lowering the cooling temperature produces only a maximum 10 percent increase in cooling rates; confirming the main benefit of plunging in slush over liquid nitrogen does not arise from their temperature difference. Numerical simulations also demonstrated that a hypothetical four-fold increase in the cooling rate of vitrification devices when plunging in slush nitrogen would be explained by an increase in heat transfer coefficient. This improvement in heat transfer (i.e., high cooling rates) in slush nitrogen is attributed to less or null film boiling when a sample is placed in slush (mixture of liquid and solid nitrogen) because it first melts the solid nitrogen before causing the liquid to boil and form a film.

  11. Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

    1990-10-01

    Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

  12. 15-30 Effect of Weed Management Methods and Nitrogen Fertilizer

    African Journals Online (AJOL)

    tosheba

    Nitrogen Use Efficiency of Bread Wheat (Triticum aestivum L.) in Southern Ethiopia. Tamado Tana1*, Dawit ... in Ethiopia, dominating food habits and dietary practices, and is known .... Nationalities and People's Regional State. 2.6. ..... Page 7 ...

  13. A neutronic method to determine low hydrogen concentrations in metals

    International Nuclear Information System (INIS)

    Bennun, Leonardo; Santisteban, Javier; Diaz-Valdes, J.; Granada, J.R.; Mayer, R.E.

    2007-01-01

    We propose a method for the non-destructive determination of low hydrogen content in metals. The method is based on measurements of neutron inelastic scattering combined with cadmium filters. Determination is simple and the method would allow to construct a mobile device, to perform the analysis 'in situ'. We give a brief description of the usual methods to determine low hydrogen contents in solids, paying special attention to those methods supported by neutron techniques. We describe the proposed method, calculations to achieve a better sensitivity, and experimental results

  14. Determination of sulfur dioxide by a radiorelease method

    Energy Technology Data Exchange (ETDEWEB)

    Sriman Narayanan, S.; Rao, V.R.S. (Indian Inst. of Tech., Madras. Dept. of Chemistry)

    1983-04-13

    A radiorelease technique for the determination of sulfur dioxide using radiochlor /sup 36/Cl-amine-T is described. Methods for the elimination of interference from coexisting gases are also reported. 1-40 ppm sulfur dioxide can be determined.

  15. Determination of sulfur dioxide by a radiorelease method

    International Nuclear Information System (INIS)

    Sriman Narayanan, S.; Rao, V.R.S.

    1983-01-01

    A radiorelease technique for the determination of sulfur dioxide using radiochlor 36 Cl-amine-T is described. Methods for the elimination of interference from coexisting gases are also reported. 1-40 ppm sulfur dioxide can be determined. (author)

  16. Determination of prilocaine HCl in bulk drug and pharmaceutical formulation by GC-NPD method

    Directory of Open Access Journals (Sweden)

    Atila Alptug

    2013-01-01

    Full Text Available The novel analytical method was developed and validated for determination of prilocaine HCl in bulk drug and pharmaceutical formulation by gas chromatography-nitrogen phosphorus detection (GC-NPD. The chromatographic separation was performed using a HP-5MS column. The calibration curve was linear over the concentration range of 40-1000 ng ml-1 with a correlation coefficient of 0.9998. The limits of detection (LOD and quantification (LOQ of method were 10 ng ml-1 and 35 ng ml-1, respectively. The within-day and between-day precision, expressed as the percent relative standard deviation (RSD% was less than 5.0%, and accuracy (percent relative error was better than 4.0%. The developed method can be directly and easily applied for determination of prilocaine HCl in bulk drug and pharmaceutical formulation using internal standard methodology.

  17. Exploring the nitrogen ingestion of aphids--a new method using electrical penetration graph and (15N labelling.

    Directory of Open Access Journals (Sweden)

    Franziska Kuhlmann

    Full Text Available Studying plant-aphid interactions is challenging as aphid feeding is a complex process hidden in the plant tissue. Here we propose a combination of two well established methods to study nutrient acquisition by aphids focusing on the uptake of isotopically labelled nitrogen ((15N. We combined the Electrical Penetration Graph (EPG technique that allows detailed recording of aphid feeding behaviour and stable isotope ratio mass spectrometry (IRMS to precisely measure the uptake of nitrogen. Bird cherry-oat aphids Rhopalosiphum padi L. (Hemiptera, Aphididae fed for 24 h on barley plants (Hordeum vulgare L., cultivar Lina, Poaceae that were cultivated with a (15N enriched nutrient solution. The time aphids fed in the phloem was strongly positive correlated with their (15N uptake. All other single behavioural phases were not correlated with (15N enrichment in the aphids, which corroborates their classification as non-feeding EPG phases. In addition, phloem-feeding and (15N enrichment of aphids was divided into two groups. One group spent only short time in the phloem phase and was unsuccessful in nitrogen acquisition, while the other group displayed longer phloem-feeding phases and was successful in nitrogen acquisition. This suggests that several factors such as the right feeding site, time span of feeding and individual conditions play a role for the aphids to acquire nutrients successfully. The power of this combination of methods for studying plant-aphid interactions is discussed.

  18. DETERMINATION OF CONVECTIVE HEAT TRANSFER COEFFICIENT AT THE OUTER SURFACE OF A CRYOVIAL BEING PLUNGED INTO LIQUID NITROGEN.

    Science.gov (United States)

    Wang, T; Zhao, G; Tang, H Y; Jiang, Z D

    2015-01-01

    Cell survival upon cryopreservation is affected by the cooling rate. However, it is difficult to model the heat transfer process or to predict the cooling curve of a cryoprotective agent (CPA) solution due to the uncertainty of its convective heat transfer coefficient (h). To measure the h and to better understand the heat transfer process of cryovials filled with CPA solution being plunged in liquid nitrogen. The temperatures at three locations of the CPA solution in a cryovial were measured. Different h values were selected after the cooling process was modeled as natural convection heat transfer, the film boiling and the nucleate boiling, respectively. And the temperatures of the selected points are simulated based on the selected h values. h was determined when the simulated temperature best fitted the experimental temperature. When the experimental results were best fitted, according to natural convection heat transfer model, h(1) = 120 W/(m(2)·K) while due to film boiling and nucleate boiling regimes h(f) = 5 W/(m(2)·K) followed by h(n) = 245 W/(m(2)·K). These values were verified by the differential cooling rates at the three locations of a cryovial. The heat transfer process during cooling in liquid nitrogen is better modeled as film boiling followed by nucleate boiling.

  19. Synthesis of nitrogen- and iron-containing carbon dots, and their application to colorimetric and fluorometric determination of dopamine

    International Nuclear Information System (INIS)

    Wang, Bin; Chen, Yanfen; Wu, Yuanya; Weng, Bo; Liu, Yingshuai; Li, Chang Ming

    2016-01-01

    Nitrogen- and iron-containing carbon dots (N,Fe-CDs) are synthesized by hydrothermal treatment of branched polyethylenimine (BPEI) and hemin at 180 °C. The N,Fe-CDs are mainly doped with nitrogen and trace amounts of iron(III). The N,Fe-CDs also display intrinsic fluorescence with excitation/emission maxima at 365/452 nm and a quantum yield of 27 %. The nanodots are shown to act as peroxidase mimics by catalyzing the oxidation of tetramethylbenzidine (TMB) by hydrogen peroxide to form a blue product whose quantity can be determined by photometry at 652 nm. This was exploited to design colorimetric and fluorometric assays for dopamine (DA). The colorimetric assay is based on the oxidation of DA by H2O2 in presence of the N,Fe-CDs and TMB. It has an instrumental detection limit of 40 nM (at an S/N ratio of 3), and a visual detection limit of 0.4 μM. The fluorometric assay is based on an inner filter effect that is caused by the formation of oxidized TMB which overlaps (and absorbs) the emission of the N,Fe-CDs located at 452 nm. The fluorometric detection limit is as low as 20 nM (at an S/N ratio of 3). (author)

  20. [Methods for enzymatic determination of triglycerides in liver homogenates].

    Science.gov (United States)

    Höhn, H; Gartzke, J; Burck, D

    1987-10-01

    An enzymatic method is described for the determination of triacylglycerols in liver homogenate. In contrast to usual methods, higher reliability and selectivity are achieved by omitting the extraction step.

  1. Validation of nitrogen-nitrate analysis by the chromotropic acid method

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Ana Claudia O.; Matoso, Erika, E-mail: anaclaudia.oliveira@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CTMSP/CEA), Iperó, SP (Brazil). Centro Experimental ARAMAR

    2017-07-01

    The problems caused by contamination of water bodies demand strict control of disposal in rivers, seas and oceans. Nitrate ion is present in agricultural inputs, which are applied to the soil to boost plant growth. However, excess or indiscriminate use of these products contaminates water bodies, triggering eutrophication of the aquatic ecosystems. Furthermore, due to diseases that can be caused by the ingestion of high levels of nitrate, such as methaemoglobinaemia, nitrate levels should be controlled in drinking waters and effluents. There are several methods for the determination of nitrate, being the chromotropic acid method a simple and low-cost solution. This method consists of acid addition into the sample in the presence of H{sub 2}SO{sub 4}. The absorbance related to the produced yellow color can be measured by a UV-Vis spectrophotometer at 410 nm. In a modified form, this method can be applied to different aqueous matrices by use of other reagents that eliminate interferences. The aim of this study was to validate the nitrate determination method in waters using chromotropic acid. This method is used in Laboratório Radioecológico (LARE) to analyze effluent to comply with Wastewater Controlling Program of Centro Tecnológico da Marinha em São Paulo – Centro Experimental ARAMAR (CTMSP-CEA). The correlation coefficient for the linearity test was 0.9997. The evaluated detection limit was relatively high (LD = 0.045 mgN/L), if compared to ion chromatography, for example, but enough to determine the presence of this ion, considering the maximum limit proposed by the current legislation. The chromotropic acid method showed to be a robust, accurate and precise method, according the parameters used in this work. (author)

  2. Validation of nitrogen-nitrate analysis by the chromotropic acid method

    International Nuclear Information System (INIS)

    Santos, Ana Claudia O.; Matoso, Erika

    2017-01-01

    The problems caused by contamination of water bodies demand strict control of disposal in rivers, seas and oceans. Nitrate ion is present in agricultural inputs, which are applied to the soil to boost plant growth. However, excess or indiscriminate use of these products contaminates water bodies, triggering eutrophication of the aquatic ecosystems. Furthermore, due to diseases that can be caused by the ingestion of high levels of nitrate, such as methaemoglobinaemia, nitrate levels should be controlled in drinking waters and effluents. There are several methods for the determination of nitrate, being the chromotropic acid method a simple and low-cost solution. This method consists of acid addition into the sample in the presence of H 2 SO 4 . The absorbance related to the produced yellow color can be measured by a UV-Vis spectrophotometer at 410 nm. In a modified form, this method can be applied to different aqueous matrices by use of other reagents that eliminate interferences. The aim of this study was to validate the nitrate determination method in waters using chromotropic acid. This method is used in Laboratório Radioecológico (LARE) to analyze effluent to comply with Wastewater Controlling Program of Centro Tecnológico da Marinha em São Paulo – Centro Experimental ARAMAR (CTMSP-CEA). The correlation coefficient for the linearity test was 0.9997. The evaluated detection limit was relatively high (LD = 0.045 mgN/L), if compared to ion chromatography, for example, but enough to determine the presence of this ion, considering the maximum limit proposed by the current legislation. The chromotropic acid method showed to be a robust, accurate and precise method, according the parameters used in this work. (author)

  3. Comparative response of wheat and oilseed rape to nitrogen supply: absorption and utilisation efficiency of radiation and nitrogen during the reproductive stages determining yield

    NARCIS (Netherlands)

    Dreccer, M.F.; Schapendonk, A.H.C.M.; Slafer, G.A.; Rabbinge, R.

    2000-01-01

    We investigated the response of spring wheat and oilseed rape to nitrogen (N) supply, focusing on the critical period for grain number definition and grain filling. Crops were grown in containers under a shelter and treated with five combinations of applied N. Wheat and oilseed rape produced

  4. Uptake of fertilizer nitrogen and soil nitrogen by rice using 15N-labelled nitrogen fertilizer

    International Nuclear Information System (INIS)

    Reddy, K.R.; Patrick, W.H. Jr.

    1980-01-01

    Data from five field experiments using labelled nitrogen fertilizer were used to determine the relative effects of soil nitrogen and fertilizer nitrogen on rice yield. Yield of grain was closely correlated with total aboveground nitrogen uptake (soil + fertilizer), less closely correlated with soil nitrogen uptake and not significantly correlated with fertilizer nitrogen uptake. When yield increase rather than yield was correlated with fertilizer nitrogen uptake, the correlation coefficient was statistically significant. (orig.)

  5. Determination of desipramine in biological samples using liquid-liquid-liquid microextraction combined with in-syringe derivatization, gas chromatography, and nitrogen/phosphorus detection.

    Science.gov (United States)

    Saraji, Mohammad; Mehrafza, Narges; Bidgoli, Ali Akbar Hajialiakbari; Jafari, Mohammad Taghi

    2012-10-01

    A method was established for the determination of desipramine in biological samples using liquid-liquid-liquid microextraction followed by in-syringe derivatization and gas chromatography-nitrogen phosphorus detection. The extraction method was based on the use of two immiscible organic solvents. n-Dodecane was impregnated in the pores of the hollow fiber and methanol was placed inside the lumen of the fiber as the acceptor phase. Acetic anhydride was used as the reagent for the derivatization of the analyte inside the syringe barrel. Parameters that affect the extraction efficiency (composition of donor and acceptor phase, ionic strength, sample temperature, and extraction time) as well as derivatization efficiency (amount of acetic anhydride and reaction time and temperature) were investigated. The limit of detection was 0.02 μg/L with intra and interday RSDs of 2.6 and 7.7%, respectively. The linearity of the method was in the range of 0.2-20 μg/L (r(2) = 0.9986). The method was successfully applied to determine desipramine in human plasma and urine. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Nitrate signals determine the sensing of nitrogen through differential expression of genes involved in nitrogen uptake and assimilation in finger millet.

    Science.gov (United States)

    Gupta, Alok Kumar; Gaur, Vikram Singh; Gupta, Sanjay; Kumar, Anil

    2013-06-01

    In order to understand the molecular basis of high nitrogen use efficiency of finger millet, five genes (EcHNRT2, EcLNRT1, EcNADH-NR, EcGS, and EcFd-GOGAT) involved in nitrate uptake and assimilation were isolated using conserved primer approaches. Expression profiles of these five genes along with the previously isolated EcDof1 was studied under increased KNO3 concentrations (0.15 to 1,500 μM) for 2 h as well as at 1.5 μM for 24 h in the roots and shoots of 25 days old nitrogen deprived two contrasting finger millet genotypes (GE-3885 and GE-1437) differing in grain protein content (13.76 and 6.15 %, respectively). Time kinetics experiment revealed that, all the five genes except EcHNRT2 in the leaves of GE-3885 were induced within 30 min of nitrate exposure indicating that there might be a greater nitrogen deficit in leaves and therefore quick transportation of nitrate signals to the leaves. Exposing the plants to increasing nitrate concentrations for 2 h showed that in roots of GE-3885, NR was strongly induced while GS was repressed; however, the pattern was found to be reversed in leaves of GE-1437 indicating that in GE-3885, most of the nitrate might be reduced in the roots but assimilated in leaves and vice-versa. Furthermore, compared with the low-protein genotype, expression of HNRT2 was strongly induced in both roots and shoots of high-protein genotype at the least nitrate concentration supplied. This further indicates that GE-3885 is a quick sensor of nitrogen compared with the low-protein genotype. Furthermore, expression of EcDof1 was also found to overlap the expression of NR, GS, and GOGAT indicating that Dof1 probably regulates the expression of these genes under different conditions by sensing the nitrogen fluctuations around the root zone.

  7. The effect of different levels of fertilizer on nitrogen nutrient of pasture using 15N-isotope dilution method

    International Nuclear Information System (INIS)

    Wei Dongpu; Bai Lingyu; Hua Luo; Yao Yunyin

    2000-01-01

    A pot experiment was carried out to study the effect of different levels of fertilizer on N% of ryegrass in monoculture or mixed culture with white clover and symbiotic dinitrogen fixation of white clover by using 15 N-isotope dilution method. It showed that (1) N% of ryegrass in monoculture or mixed culture was the highest at 67 days after fertilizing (DAF) and decreased with time; (2) N% of white clover was the greatest at 67 DAF, slightly decreased at 92 DAF, and then increased at 137 DAF, related to the increasing of nitrogen fixation by white clover; (3) At 164 kg 15 NH 4 SO 4 /hm 2 , N% of ryegrass in mixed culture at different cutting time was greater than that in monoculture. It obviously occurred that fixed nitrogen was transferred from white clover to ryegrass in mixed; (4) During the whole growth period, the main nitrogen resource of white clover was symbiotic dinitrogen fixation and that of ryegrass was soil nitrogen; (5) Effect of different levels of applied N on N% of ryegrass and white clover was significant

  8. Methods of soil organic carbon determination in Brazilian savannah soils

    Directory of Open Access Journals (Sweden)

    Juliana Hiromi Sato

    2014-08-01

    Full Text Available Several methods exist for determining soil organic carbon, and each one has its own advantages and limitations. Consequently, a comparison of the experimental results obtained when these methods are employed is hampered, causing problems in the comparison of carbon stocks in soils. This study aimed at evaluating the analytical procedures used in the determination of carbon and their relationships with soil mineralogy and texture. Wet combustion methods, including Walkley-Black, Mebius and Colorimetric determination as well as dry combustion methods, such as Elemental and Gravimetric Analysis were used. Quantitative textural and mineralogical (kaolinite, goethite and gibbsite analyses were also carried out. The wet digestion methods underestimated the concentration of organic carbon, while the gravimetric method overestimated. Soil mineralogy interfered with the determination of carbon, with emphasis on the gravimetric method that was greatly influenced by gibbsite.

  9. [Determination of aluminium in flour foods with photometric method].

    Science.gov (United States)

    Ma, Lan; Zhao, Xin; Zhou, Shuang; Yang, Dajin

    2012-05-01

    To establish a determination method for aluminium in flour foods with photometric method. After samples being treated with microwave digestion and wet digestion, aluminium in staple flour foods was determined by photometric method. There was a good linearity of the result in the range of 0.25 - 5.0 microg/ml aluminium, r = 0.9998; limit of detection (LOD) : 2.3 ng/ml; limit of quantitation (LOQ) : 7 ng/ml. This method of determining aluminium in flour foods is simple, rapid and reliable.

  10. Method for the radioactive determination of the foliates

    International Nuclear Information System (INIS)

    Rosen, H.

    1976-01-01

    A method is described for the radioactive determination of the foliates, in which a determination is made of the uptake on a protein fraction of the milk taking up the foliates by competition between the foliate(s) to be determined and a folic acid by-product labelled with a radioactive isotope. The characteristics of this method is that it consists in using tyramide of iodinated folic acid 125 [fr

  11. New method for determination of star formation history

    OpenAIRE

    Čeponis, Marius

    2017-01-01

    A New Method for Determination of Star Formation History Without stars there would not be any life and us. Almost all elements in our bodies are made in stars. Yet we still don‘t fully understand all the processes governing formation and evolution of stellar systems. Their star formation histories really help in trying to understand these processes. In this work a new Bayesian method for determination of star formation history is proposed. This method uses photometric data of resolved stars a...

  12. Methods for determining the preatmospheric dimensions of meteorites

    Science.gov (United States)

    Ustinova, G. K.; Alekseev, V. A.; Lavrukhina, A. K.

    1988-10-01

    Methods are proposed for the determination of the preatmospheric size of a meteorite on the basis of data on its cosmogenic radionuclides. Optimal conditions for the application of each of these methods are presented together with the demonstration of their effectiveness. Estimates of relative dimensions determined by these methods are presented for the Harleton, St. Severin, Lost City, Peace River, Pribram, Dhajala, Innisfree, Bruderheim, Ehole, and Gorlovka chondrites and for the Iardymly, Boguslavka, Treysa, and Sikhote-Alin' iron meteorites.

  13. A Method for Determining Optimal Residential Energy Efficiency Packages

    Energy Technology Data Exchange (ETDEWEB)

    Polly, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gestwick, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bianchi, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Anderson, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Horowitz, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Judkoff, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2011-04-01

    This report describes an analysis method for determining optimal residential energy efficiency retrofit packages and, as an illustrative example, applies the analysis method to a 1960s-era home in eight U.S. cities covering a range of International Energy Conservation Code (IECC) climate regions. The method uses an optimization scheme that considers average energy use (determined from building energy simulations) and equivalent annual cost to recommend optimal retrofit packages specific to the building, occupants, and location.

  14. Determination of resonance parameters in QCD by functional analysis methods

    International Nuclear Information System (INIS)

    Ciulli, S.; Geniet, F.; Papadopoulos, N.A.; Schilcher, K.

    1988-01-01

    A mathematically rigorous method based on functional analysis is used to determine resonance parameters of an amplitude from its given asymptotic expression in the space-like region. This method is checked on a model amplitude where both the asymptotic expression and the exact function are known. This method is then applied to the determination of the mass and the width of the ρ-meson from the corresponding space-like asymptotic QCD expression. (orig.)

  15. Role of iron catalyst impregnated by solvent swelling method in pyrolytic removal of coal nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, J.; Kusakabe, K.; Morooka, S.; Nielsen, M.; Furimsky, E. [Kyushu University, Fukuoka (Japan). Dept. of Chemical Science and Technology

    1995-11-01

    Organometallic iron precursors, ferrocene and ferric acetate, were impregnated into Illinois No. 6 (IL), Wyoming (WY) and Yallourn (YL) coals by solvent swelling technique in THF, ethanol, and a THF/ethanol binary solvent. Then iron-impregnated coals were pyrolyzed in a flow of helium at atmospheric pressure in a fixed bed and a thermobalance. Conversion of coal nitrogen to N{sub 2} was 20, 38 and 30% respectively, for original IL, WY, and YL coals. Iron formed from both precursors lowered the onset temperature of N{sub 2} evolution by 20-100{degree}C. When ferrocene was impregnated in coals at a concentration of 1.7-1.8 wt% as Fe, nitrogen conversion was increased to 52, 71 and 68% for IL, WY and YL coals, respectively. Ferric acetate impregnated into IL coal from THF/ethanol solution increased the nitrogen conversion much more than that from ethanol solution. The expansion of microporous coal structure by the swelling was essential for better dispersion of the catalyst precursor. The evolution of HCN as well as NH{sub 3} was effectively suppressed above 600{degree}C by the presence of iron but not influenced significantly by combinations of catalyst precursors and solvents. The increase in N{sub 2} yield was compensated by the decrease in nitrogen emitted as HCN and NH{sub 3} and in tar and char. The increase in CO evolution from the iron-impregnated IL coal at 600-800{degree}C was explained by catalytic rearrangement of aromatic structure of char, accompanying the removal of nitrogen as N{sub 2}. In a range of 600-750{degree}C, the evolution of CO as well as N{sub 2} from the other coals increased remarkably with a significant decrease in CO{sub 2} gasification in char microproes. 32 refs., 9 figs., 3 tabs.

  16. 40 CFR Appendix B to Part 76 - Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Procedures and Methods for Estimating Costs of Nitrogen Oxides Controls Applied to Group 1, Boilers B Appendix B to Part 76 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES...

  17. Determination of beta attenuation coefficients by means of timing method

    International Nuclear Information System (INIS)

    Ermis, E.E.; Celiktas, C.

    2012-01-01

    Highlights: ► Beta attenuation coefficients of absorber materials were found in this study. ► For this process, a new method (timing method) was suggested. ► The obtained beta attenuation coefficients were compatible with the results from the traditional one. ► The timing method can be used to determine beta attenuation coefficient. - Abstract: Using a counting system with plastic scintillation detector, beta linear and mass attenuation coefficients were determined for bakelite, Al, Fe and plexiglass absorbers by means of timing method. To show the accuracy and reliability of the obtained results through this method, the coefficients were also found via conventional energy method. Obtained beta attenuation coefficients from both methods were compared with each other and the literature values. Beta attenuation coefficients obtained through timing method were found to be compatible with the values obtained from conventional energy method and the literature.

  18. Evaluation Of Three Methods Of Sugar Analyses For Determination ...

    African Journals Online (AJOL)

    Chemical methods developed by Lane and Eynon, Knight and Allen, and colorimetric method by Dubois et al were used to determine reducing sugar in eight fruit samples. The methods showed detection limits as follows: Lane and Eynon (1ppt); Knight and Allen (0.1ppt); and Dubois et al (<2ppm). The coefficients of ...

  19. A flexible method for multi-level sample size determination

    International Nuclear Information System (INIS)

    Lu, Ming-Shih; Sanborn, J.B.; Teichmann, T.

    1997-01-01

    This paper gives a flexible method to determine sample sizes for both systematic and random error models (this pertains to sampling problems in nuclear safeguard questions). In addition, the method allows different attribute rejection limits. The new method could assist achieving a higher detection probability and enhance inspection effectiveness

  20. A Spectrophotometric Method for the Determination of Ramipril in ...

    African Journals Online (AJOL)

    A Spectrophotometric Method for the Determination of Ramipril in Solid Dosage Forms. ... Tropical Journal of Pharmaceutical Research ... Methods: UV spectrophotometry was used to develop and validate a simple method for the assay of ramipril in solid dosage form at λmax of 210 nm, as per International Conference on ...

  1. Determination of nitrogen in wheat flour through Activation analysis using Fast neutron flux of a Thermal nuclear reactor; Determinacion de nitrogeno en harina de trigo mediante analisis por activacion empleando el flujo de neutrones rapidos de un reactor nuclear termico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez G, T

    1976-07-01

    In this work is done a technical study for determining Nitrogen (protein) and other elements in wheat flour Activation analysis, with Fast neutrons from a Thermal nuclear reactor. Initially it is given an introduction about the basic principles of the methods of analysis. Equipment used in Activation analysis and a brief description of the neutron source (Thermal nuclear reactor). The realized experiments for determining the flux form in the irradiation site, the half life of N-13 and the interferences due to the sample composition are included too. Finally, the obtained results by Activation and the Kjeldahl method are tabulated. (Author)

  2. Temperature dependence of nitrogen solubility in iron base multicomponent melts

    International Nuclear Information System (INIS)

    Sokolov, V.M.; Koval'chuk, L.A.

    1986-01-01

    Method for calculating temperature dependence of nitrogen solubility in iron base multicomponent melts is suggested. Application areas of existing methods were determined and advantages of the new method for calculating nitrogen solubility in multicomponent-doped iron melts (Fe-Ni-Cr-Mo, Fe-Ni-Cr-Mn, Fe-Mo-V) at 1773-2073 K are shown

  3. Determining the internal quantum efficiency of shallow-implanted nitrogen-vacancy defects in bulk diamond

    DEFF Research Database (Denmark)

    Radko, Ilya; Boll, Mads; Israelsen, Niels Møller

    2016-01-01

    -implanted NV defects in a single-crystal bulk diamond. Using a spherical metallic mirror with a large radius of curvature compared to the optical spot size, we perform calibrated modifications of the local density of states around NV defects and observe the change of their total decay rate, which is further...... used for IQE quantification. We also show that at the excitation wavelength of 532 nm, photo-induced relaxation cannot be neglected even at moderate excitation powers well below the saturation level. For NV defects shallow implanted 4.5 ± 1 and 8 ± 2 nm below the diamond surface, we determine...

  4. Determination of crystallinity of ceramic materials from the Ruland Method

    International Nuclear Information System (INIS)

    Kniess, C.T.; Prates, P.B.; Gomes Junior, J.C.; Lima, J.C. de; Riella, H.G.; Kuhnen, N.C.

    2011-01-01

    Some methods found in literature approach the different characteristics between crystalline and amorphous phases by X ray diffraction technique. These methods use the relation between the intensities of the crystalline peaks and background amorphous or the absolute intensity of one of these to determine the relative amount of crystalline and amorphous material. However, a crystalline substance presents shows coherent diffuse scattering and a loss in the intensity of the peaks of diffraction in function of thermal vibrations of atoms and imperfections in the crystalline structure. A correct method for the determination of the crystallinity must take in account these effects. This work has as objective to determine the crystallinity of ceramic materials obtained with the addition of mineral coal bottom ashes, using the X ray diffraction technique and the Ruland Method, that considers the diminution of the intensity of the crystalline peak because of the disorder affects. The Ruland Method shows adequate for the determination of the crystallinity of the ceramic materials. (author)

  5. Radioimmunological method for determination of cortisol in saliva

    International Nuclear Information System (INIS)

    Maleeva, A.; Mileva, Zh.; Kekhajova, M.

    1989-01-01

    A method was developed for determination of cortisol in saliva after being previously extracted with dichlormethane. Cortisol concentration in saliva of 19 subjects was determined by this method. The saliva cortisol levels were compared with those of blood plasma. No statistically significant difference was found. The method finds acceptance primarily when frequent measurements of cortisol level are neccessary as a screening technique and when strongly abnormally high levels should be differentiated from the normal ones: in this latter case determination of plasma cortisol is mandatory. 5 tabs., 8 refs

  6. Effects of Salinity and Nitrogen Application Methods on Yield and Yield Components of Wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    R Farshid

    2012-07-01

    Full Text Available To evaluate interaction of salinity stress and nitrogen use methods on yield and yield components, in experiment was conducted in split plot in randomized complete block with 3 replications. Treatments included: salinity of irrigation water levels 1.5, 4.4 and 7.9 ds/m as main plots, and nitrogen treatments 1. using N fertilizer at 3 stage in soil, 2. using two third N fertilizer in soil at planting and tillering and heading and one third in form of foliar application of N at tillering, 4. using and one third in form of foliar application at heading, 3. Using two third of N fertilizer in soil at planting one third of N fertilizer in soil at planting and two third in form of foliar application at tillering and heading, as sub plots. Results this study showed that increased in salt stress significant decreased total yield components such that showed decrease 41/5 kg/h in yield with increase in per unite salinity. Also methods of nitrogen application in salinity condition, have significant effects on total yield components. At the tillering, one stage of foliar with soil application of urea could increase spike no. m-2 and kernels of spike compared with other treatments. Foliar application of urea at heading stage increased kernels weight.

  7. Soil-N tagging - a method for measurement of biological nitrogen fixation in cereal-legume intercropping system

    International Nuclear Information System (INIS)

    Patra, D.D.; Subbiah, B.V.; Sachdev, M.S.

    1985-01-01

    The quantitative estimates of atmospheric dinitrogen fixed by the legume crop and transferred to the associated cereal in cereal-legume intercropping system of maize-cowpea and wheat-gram using soil and fertilizer nitrogen labelling with 15 N have been reported. The estimates of N-fixation have been compared with the similar data from A-value method. Under field conditions sole cropped cowpea fixed 53.7 per cent of its total N uptake while as intercrop with maize fixed 43.5 per cent. Maize crop got 27.6 per cent of its total N uptake by transference of the nitrogen fixed by the intercropped cowpea. In the wheat-gram intercropping system the corresponding values under greenhouse conditions were 35.0, 44.8 and 20.2 per cent, respectively. (author)

  8. Quenching of the OH and nitrogen molecular emission by methane addition in an Ar capacitively coupled plasma to remove spectral interference in lead determination by atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Frentiu, T., E-mail: ftibi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Ponta, M., E-mail: mponta@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Mihaltan, A.I., E-mail: alinblaj2005@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Darvasi, E., E-mail: edarvasi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Frentiu, M., E-mail: frentiu.maria@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Cordos, E., E-mail: emilcordos@gmail.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania)

    2010-07-15

    A new method is proposed to remove the spectral interference on elements in atomic fluorescence spectrometry by quenching of the molecular emission of the OH radical (A{sup 2{Sigma}+} {yields} X{sup 2{Pi}}) and N{sub 2} second positive system (C{sup 3{Pi}}{sub u} {yields} B{sup 3{Sigma}}{sub g}) in the background spectrum of medium power Ar plasmas. The experiments were carried out in a radiofrequency capacitively coupled plasma (275 W, 27.12 MHz) by CH{sub 4} addition. The quenching is the result of the high affinity of OH radical for a hydrogen atom from the CH{sub 4} molecule and the collisions of the second kind between nitrogen excited molecules and CH{sub 4}, respectively. The decrease of the emission of N{sub 2} second positive system in the presence of CH{sub 4} is also the result of the deactivation of the metastable argon atoms that could excite the nitrogen molecules. For flow rates of 0.7 l min{sup -1} Ar with addition of 7.5 ml min{sup -1} CH{sub 4}, the molecular emission of OH and N{sub 2} was completely removed from the plasma jet spectrum at viewing heights above 60 mm. The molecular emission associated to CH and CH{sub 2} species was not observed in the emission spectrum of Ar/CH{sub 4} plasma in the ultraviolet range. The method was experimented for the determination of Pb at 283.31 nm by atomic fluorescence spectrometry with electrodeless discharge lamp and a multichannel microspectrometer. The detection limit was 35 ng ml{sup -1}, 2-3 times better than in atomic emission spectrometry using the same plasma source, and similar to that in hollow cathode lamp microwave plasma torch atomic fluorescence spectrometry.

  9. Isotope Tracer Methods for Investigations Of Nitrogen Deficiency In Castle Lake, California

    International Nuclear Information System (INIS)

    Axler, R.P.; Goldman, C.R.

    1981-01-01

    Castle Lake is a subalpine lake located in northern California. Thermal stratification is well developed soon after ice-thaw and persists until fall overturn. The epilimnion during the major portion of the growing season (mid-June to mid-September) is characterized by relatively constant temperature and depth (19±3°C, 5±2m respectively), high transparency (η = 0.21 m -1 ), low phytoplankton productivity (∼3 mg C m -3 hr -1 at midday), and low levels of dissolved inorganic nitrogen (≲5 μg N 1 -1 ) and phosphorus (≲1 μg P 1 -1 ). Nitrogen-fixing algae are not present in the water column and nutrient inputs derived from precipitation and surface inflow are generally negligible by early July

  10. Experimental determination of the bulk temperature values in a nonisothermal flow of the chemically reacting nitrogen tetroxide

    International Nuclear Information System (INIS)

    Devojno, A.N.; Kolykhan, L.I.; Stepanenko, V.N.; Tverkovkin, B.E.; Uyutov, G.I.

    1975-01-01

    The technique and results of an experimental determination of mean mass temperatures of a cooled chemically active nitrogen tetroxide flowing in a circular tube under turbulent flow conditions are considered. The parameters range as follows: pressure-from 8.10 5 to 16.10 5 H/m 2 , flow temperature-from 140 deg to 550 deg C, Reynolds number-from 3,1.1g 5 , flow velocity-from 3.5 to 45 m/s. The gas temperature along the length of the test tube is measured with movable probe with a mixer and thermocouple in a stainless steel capillary 2mm in dia and the wall 0,2 mm thick. The mean-square deviations of measured temperature values from the predicted ones are about -0.9 and +1.8%. The obtained data show the predicted temperature values to be somewhat lower than the measured ones, the difference increasing with the distance to the test tube outlet. It may be explained by both unaccounted systematic experimental errors and errors in calculating the mean mass flow temperatures. The investigation described confirms the possibility of an experimental determination of the mean gas temperature along the cooled channel length by mean mass of a movable mixer with a single thermocouple

  11. Automatic Hypocenter Determination Method in JMA Catalog and its Application

    Science.gov (United States)

    Tamaribuchi, K.

    2017-12-01

    The number of detectable earthquakes around Japan has increased by developing the high-sensitivity seismic observation network. After the 2011 Tohoku-oki earthquake, the number of detectable earthquakes have dramatically increased due to its aftershocks and induced earthquakes. This enormous number of earthquakes caused inability of manually determination of all the hypocenters. The Japan Meteorological Agency (JMA), which produces the earthquake catalog in Japan, has developed a new automatic hypocenter determination method and started its operation from April 1, 2016. This method (named PF method; Phase combination Forward search method) can determine the hypocenters of earthquakes that occur simultaneously by searching for the optimal combination of P- and S-wave arrival times and the maximum amplitudes using a Bayesian estimation technique. In the 2016 Kumamoto earthquake sequence, we successfully detected about 70,000 aftershocks automatically during the period from April 14 to the end of May, and this method contributed to the real-time monitoring of the seismic activity. Furthermore, this method can be also applied to the Earthquake Early Warning (EEW). Application of this method for EEW is called the IPF method and has been used as the hypocenter determination method of the EEW system in JMA from December 2016. By developing this method further, it is possible to contribute to not only speeding up the catalog production, but also improving reliability of the early warning.

  12. Enhancement of periodate-hydrogen peroxide chemiluminescence by nitrogen doped carbon dots and its application for the determination of pyrogallol and gallic acid.

    Science.gov (United States)

    Shah, Syed Niaz Ali; Li, Haifang; Lin, Jin-Ming

    2016-06-01

    A new sensitized chemiluminescence (CL) was developed to broaden the analytical application of KIO4-H2O2 system. The nitrogen doped carbon dots (N-CDs) dramatically boosted the CL intensity of KIO4-H2O2 system which was further enriched by basic medium. In light of EPR analysis, free radical scavenging studies and CL spectra the detail mechanism for the enhancement was conferred in the presence of N-CDs and NaOH. The results suggested that CL of KIO4-H2O2 system in the presence and absence of N-CDs and NaOH proceeds via radical pathway. The enhanced CL was used for the determination of pyrogallol and gallic acid in range of 1.0×10(-4)-1.0×10(-7)M with 4.6×10(-8) and 6.1×10(-8)M limit of detection respectively. The relative standard deviation (RSD) at a concentration of 10(-5) for gallic acid and pyrogallol was 1.4% and 2.3% respectively (n=11). The attained results unveil that the present method is sensitive, faster, simpler and less costly compared to other methods and could be applied to determine polyphenols in real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Determination of Total Volatile Basic Nitrogen (TVB-N Content in Beef by Hyperspectral Imaging Technique

    Directory of Open Access Journals (Sweden)

    Liu Shanmei

    2016-01-01

    Full Text Available Non-destructive determination of TVB-N content in beef using hyperspectral imaging (HSI technique was evaluated. In order to create a robust model to predict the TVB-N content in beef, partition of sample set, spectral pretreatment, and the optimum wavelength selection were discussed. After the beef sample set was parted by concentration gradient (CG algortithm, and the spectra of beef samples were preprocessed by standard normalized variate (SNV combined with auto scale(AS, the partial least square regression (PLSR model was established using the full spectral range, which had the best prediction abilities with Rcv2 of 0.9124, Rp2 of 0.8816, RMSECV of 1.5889, and RMSEP of 1.7719, respectively. After the optimum wavelengths which is closely related to the TVB-N content of beef samples was obtained using the competitive adaptive re-weighted (CARS algorithm, a new PLSR model was established using the optimum wavelengths, which had outstanding prediction abilities with Rcv2 of 0.9235, Rp2 of 0.9241, RMSECV of 1.4881, and RMSEP of 1.4882, respectively.The study showed that HSI is a powerful technique to predict the TVB-N content in beef by a nondestructive way.

  14. An Aggregated Method for Determining Railway Defects and Obstacle Parameters

    Science.gov (United States)

    Loktev, Daniil; Loktev, Alexey; Stepanov, Roman; Pevzner, Viktor; Alenov, Kanat

    2018-03-01

    The method of combining algorithms of image blur analysis and stereo vision to determine the distance to objects (including external defects of railway tracks) and the speed of moving objects-obstacles is proposed. To estimate the deviation of the distance depending on the blur a statistical approach, logarithmic, exponential and linear standard functions are used. The statistical approach includes a method of estimating least squares and the method of least modules. The accuracy of determining the distance to the object, its speed and direction of movement is obtained. The paper develops a method of determining distances to objects by analyzing a series of images and assessment of depth using defocusing using its aggregation with stereoscopic vision. This method is based on a physical effect of dependence on the determined distance to the object on the obtained image from the focal length or aperture of the lens. In the calculation of the blur spot diameter it is assumed that blur occurs at the point equally in all directions. According to the proposed approach, it is possible to determine the distance to the studied object and its blur by analyzing a series of images obtained using the video detector with different settings. The article proposes and scientifically substantiates new and improved existing methods for detecting the parameters of static and moving objects of control, and also compares the results of the use of various methods and the results of experiments. It is shown that the aggregate method gives the best approximation to the real distances.

  15. Methodic of payment determination for environment pollution. Chapter 2

    International Nuclear Information System (INIS)

    1997-01-01

    In the chapter 2 the methodic for determination of payments for environmental impacts from coal thermal power plant including the specifications of enterprises payments for harmful gases discharges into atmosphere and payments for solid wastes disposition is presented

  16. EVALUATION OF ANALYTICAL METHODS FOR DETERMINING PESTICIDES IN BABY FOOD

    Science.gov (United States)

    Three extraction methods and two detection techniques for determining pesticides in baby food were evaluated. The extraction techniques examined were supercritical fluid extraction (SFE), enhanced solvent extraction (ESE), and solid phase extraction (SPE). The detection techni...

  17. Laboratory methods for determining pneumonia etiology in children

    NARCIS (Netherlands)

    Murdoch, David R.; O'Brien, Katherine L.; Driscoll, Amanda J.; Karron, Ruth A.; Bhat, Niranjan; Black, Robert E.; Bhutta, Zulfiqar A.; Campbell, Harry; Cherian, Thomas; Crook, Derrick W.; de Jong, Menno D.; Dowell, Scott F.; Graham, Stephen M.; Klugman, Keith P.; Lanata, Claudio F.; Madhi, Shabir A.; Martin, Paul; Nataro, James P.; Piazza, Franco M.; Qazi, Shamim A.; Zar, Heather J.; Levine, Orin S.; Knoll, Maria Deloria; Feikin, Daniel R.; Scott, J. Anthony G.; Driscoll, Amanda; DeLuca, Andrea; Crawley, Jane

    2012-01-01

    Laboratory diagnostics are a core component of any pneumonia etiology study. Recent advances in diagnostic technology have introduced newer methods that have greatly improved the ability to identify respiratory pathogens. However, determining the microbial etiology of pneumonia remains a challenge,

  18. Comparison of the methods for determination of scintillation light yield

    CERN Document Server

    Sysoeva, E; Zelenskaya, O

    2002-01-01

    One of the most important characteristics of scintillators is the light yield. It depends not only on the properties of scintillators, but also on the conditions of measurements. Even for widely used crystals, such as alkali halide scintillators NaI(Tl) and CsI(Tl), light yield data, obtained by various authors, are different. Therefore, it is very important to choose the convenient method of the light yield measurements. In the present work, methods for the determination of the physical light yield, based on measurements of pulse amplitude, single-electron pulses and intrinsic photomultiplier resolution are discussed. These methods have been used for the measurements of light yield of alkali halide crystals and oxide scintillators. Repeatability and reproducibility of results were determined. All these methods are rather complicated in use, not for measurements, but for further data processing. Besides that, they demand a precise determination of photoreceiver's parameters, as well as determination of light ...

  19. On the virtue of acid–base titrations for the determination of basic sites in nitrogen doped carbon nanotubes

    NARCIS (Netherlands)

    Bitter, J.H.; van Dommele, S.; de Jong, K.P.

    2013-01-01

    The basicity and nature of basic species in nitrogen containing carbon nanotubes (NCNT) prepared under different conditions were investigated by acid–base titrations. Proton uptake curves were derived from the titration data and were used to establish the basicity (pKa) ranges of nitrogen species

  20. Chemical methods for the determination of composition of cryolite

    International Nuclear Information System (INIS)

    Shivarudrappa, V.; Patil, B.N.; Marathe, S.G.; Jain, H.C.

    1989-01-01

    Preparation of uranium and plutonium alloys containing aluminium involves the use of cryolite and many times, cryolite which may be contaminated with alpha activity has to be analysed for its purity. In view of this, chemical methods for the determination of composition of commercial cryolite samples have been developed. Methods are standardised for the determination of individual constituents of cryolite viz., aluminium, sodium, fluoride and major impurities, calcium and magnesium. Studies on the dissolution of the sample, effect of one or more components on the determination of the other and their elimination are carried out. Aluminium and sodium are determined gravimetrically as oxinate and triple acetate respectively. Fluoride is determined by a volumetric procedure after cation exchange separtion of soluble fluoride. Calcium and magnesium are determined by a sequential pH-metri titration. This report describes the details of the procedures and the results of these studies for two commercial cryolite samples. (author). 7 tabs

  1. System and method for determining stability of a neural system

    Science.gov (United States)

    Curtis, Steven A. (Inventor)

    2011-01-01

    Disclosed are methods, systems, and computer-readable media for determining stability of a neural system. The method includes tracking a function world line of an N element neural system within at least one behavioral space, determining whether the tracking function world line is approaching a psychological stability surface, and implementing a quantitative solution that corrects instability if the tracked function world line is approaching the psychological stability surface.

  2. Determination of U by the dibenzoyl methane method

    International Nuclear Information System (INIS)

    Martin, M.

    A method for the determination of U ion ores and uranium concentrates is presented. It can be applied to the measurement of U concentrations > 0.005 % in solids and > 0.02 g/l in solutions. U is extracted by trioctyl-phosphine oxide (TOPO) in solution in dodecane and determined by colorimetry [fr

  3. Determination of water content in natural zeolites by reflection method

    International Nuclear Information System (INIS)

    Sarria, Lopez P.; Desdin Garcia, V.; Freixas Lemus, V.; Dominguez Ley, O.; Csikai, G.

    1989-01-01

    Water content in natural zeolites collected from different site places in Cuba has been determined by neutron reflection method. Results show that it is possible to separate the minerals abundant in zeolite from the surrounding barren rocks. Water content of about 10% can be determined with 2-3% relative accuracy for different matrices, using 10 m measuring time

  4. Apparatus and method for determining characteristics of subsurface formations

    International Nuclear Information System (INIS)

    Coates, G.R.

    1978-01-01

    A method for the determination of a composite parameter of the formation water in formations surrounding a borehole using capture cross section data (or the conductivity) of the formation water is described and its use for the accurate determination of characteristics such as water saturation even in shaly regions, is demonstrated. (UK)

  5. Comparison of radioimmunology and serology methods for LH determination

    International Nuclear Information System (INIS)

    Szymanski, W.; Jakowicki, J.

    1976-01-01

    A comparison is presented of LH determinations by immunoassay and radioimmunoassay using the 125 I-labelled HCG double antibody system. The results obtained by both methods are well comparable and in normal and elevated LH levels the serological determinations may be used for estimating concentration levels found by RIA. (L.O.)

  6. Determination of gadolinium by the method of derivative spectrophotometry

    International Nuclear Information System (INIS)

    Aleksandrova, N.N.; Mishchenko, V.T.; Poluehktov, N.S.; Mukomel', V.L.

    1988-01-01

    Technique for gadolinium determination at the presence of interfering rare earth elements, which is based on the derivative spectrophotometry method, is suggested. The technique is of increased selectivity and allows to determine gadolinium in the mixtures with elements, which presence in solution makes impossible to determine gadolinium directly. At binary mixtures analysis Sr relative standard deviation does not exceed 0.03, while at the analysis of more complex mixtures Sr increases up to 0.06

  7. Appraisal of the nitrogen-15 natural-abundance method for quantifying dinitrogen fixation

    International Nuclear Information System (INIS)

    Bremer, E.; van Kessel, C.

    1990-01-01

    Several investigators have questioned the use of the 15 N natural-abundance method of estimating N 2 fixation because of variability in soil δ 15 N and small differences between the δ 15 N of soil N and atmospheric N. Investigations were conducted to compare the 15 N natural-abundance and 15 N-isotope-dilution methods for estimating N 2 fixation of field-grown pea (Pisum sativum L.) and lentil (Lens culinaris Medik.). Spatial variability was assessed at three sites by determining the δ 15 N of non-N 2 -fixing plants. Seasonal variation in δ 15 N for spring and winter wheat (Triticum aestivum L.), flax (Linum usitatissimum L.), barley (Hordeum vulgare L.), rape (Brassica napus L.) and lentil was determined at one site. Comparisons between δ 15 N and 15 N-enriched isotope-dilution methods for estimating N 2 fixation by lentil were conducted at several sites over a 3-yr period. Variability in δ 15 N of the reference plant was site dependent: the δ 15 N ranged from 2.8 to 9.3 at the first site, 3.4 to 8.8 at the second site, and 3.5 to 6.2 at the third site. The average δ 15 N of four of the five non-N 2 -fixing plants increased from 5.4 at 42 d after planting to 6.9 at the final harvest. The fifth non-N 2 -fixing plant, rape, accumulated most of its N during the first 42 d after planting, and its δ 15 N value declined from 8.1 at 42 d after planting to 7.3 at the final harvest. Estimates of N 2 fixation were not significantly different in 18 out of 21 comparisons; in two comparisons in the δ 15 N method and in one comparison the 15 N-enriched method provided higher estimates of N 2 fixation. Overall, both methods appeared to provide equally reliable estimates of N 2 fixation for lentil

  8. Simple method of preparing nitrogen - doped nanosized TiO2 powders of high photocatalytic activity under visible light

    International Nuclear Information System (INIS)

    Nguyen Van Hung; Dang Thi Thanh Le

    2014-01-01

    Nitrogen-doped nanosized TiO 2 powders were prepared by a simple thermal treatment method of the mixture of titanium dioxide and urea. The prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectra (UV-Vis-DRS) and Fourier transform infrared (FT-IR) spectroscopy. The results showed that the crystal structure of N-TiO 2 was a mixture of anatase and rutile phases, and the average particle size was 31 nm calculated from XRD results. The UV-vis spectra indicate an increase in absorption of visible light when compared to undoped TiO 2 . The photocatalytic activity of nitrogen-doped TiO 2 powder was evaluated by the decomposition of methylene blue under visible light irradiation. And it was found that nitrogen-doped TiO 2 powders exhibited much higher photocatalytic activity than undoped TiO 2 . Moreover, the study also showed that, the doping N atoms improve the growth of the TiO 2 crystal and phase transformation. (author)

  9. Method for determining thickness and composition of foils

    International Nuclear Information System (INIS)

    Roessiger, V.

    1984-01-01

    Subject of the invention is a radiometric method for simultaneous determination of the thickness or mass per unit area and the chemical composition of foils consisting of two or more components. The method is based on the measurement of the attenuation of several components of a suitable polychromatic radiation

  10. Evaluating an alternative method for rapid urinary creatinine determination

    Science.gov (United States)

    Creatinine (CR) is an endogenously-produced chemical routinely assayed in urine specimens to assess kidney function, sample dilution. The industry-standard method for CR determination, known as the kinetic Jaffe (KJ) method, relies on an exponential rate of a colorimetric change,...

  11. New method to determine structures in thermonuclear plasmas

    International Nuclear Information System (INIS)

    Tanzi, C.P.

    1998-01-01

    The information from tomographic methods is not always sufficient to determine fast changing structures, e.g. very hot plasmas. A new method has been developed by means of which, among other things, physical mechanisms of plasma instability can be disentangled. 4 refs

  12. A Simple HPLC Bioanalytical Method for the Determination of ...

    African Journals Online (AJOL)

    Purpose: To develop a simple, accurate, and precise high performance chromatography (HPLC) method with spectrophotometric detection for the determination of doxorubicin hydrochloride in rat plasma. Methods: Doxorubicin hydrochloride and daunorubicin hydrochloride (internal standard, IS) were separated on a C18 ...

  13. New Analytical Method for the Determination of Metronidazole in ...

    African Journals Online (AJOL)

    New Analytical Method for the Determination of Metronidazole in Human Plasma: Application to Bioequivalence Study. ... Methods: Metronidazole was extracted from human plasma through one step of ... http://dx.doi.org/10.4314/tjpr.v11i5.14.

  14. nuclear and atomic methods applied in the determination of some

    African Journals Online (AJOL)

    NAA is a quantitative and qualitative method for the precise determination of a number of major, minor and trace elements in different types of geological, environmental and biological samples. It is based on nuclear reaction between neutron and target nuclei of a sample material. It is a useful method for the simultaneous.

  15. A Method To Determine Adhesion Of Suppository Mass On Excised ...

    African Journals Online (AJOL)

    A method to determine adhesion of suppository mass to intestinal tissue was developed using excised pig intestine. The method which employs the principe of drainage unto and subsequent detachment from the mucosa, of an adherent suppository mass is simple, inexpensive and accurate. Fully optimised, it can be used ...

  16. Gallium determination with Rodamina B: a simple method

    International Nuclear Information System (INIS)

    Queiroz, R.R.U. de.

    1981-01-01

    A simple method for determining gallium with Rhodamine B, by the modification of the method proposed by Onishi and Sandell. The complex (RH) GaCl 4 is extracted with a mixture benzene-ethylacetate (3:1 V/V), from an aqueous medium 6 M in hydrochloric acid. The interference of foreign ions is studied. (C.G.C.) [pt

  17. Proposed test method for determining discharge rates from water closets

    DEFF Research Database (Denmark)

    Nielsen, V.; Fjord Jensen, T.

    At present the rates at which discharge takes place from sanitary appliances are mostly known only in the form of estimated average values. SBI has developed a measuring method enabling determination of the exact rate of discharge from a sanitary appliance as function of time. The methods depends...

  18. Experimental method to determine the role of helium in neutron-induced microstructural evolution

    International Nuclear Information System (INIS)

    Gelles, D.S.; Garner, F.A.

    1978-12-01

    A method is presented which allows the determination of the role of helium on microstructural evolution in complex alloys and which avoids many of the problems associated with other simulation experiments. It involves a direct comparison of the materials' response to a primary difference in fission and fusion environments, namely the rate of helium generation. This is accomplished by irradiating specimens in a fission reactor and conducting microstructural analyses which concentrate on alloy matrix regions adjacent to precipitates rich in boron or nitrogen. Procedures are outlined for calculation of background and injected helium levels as well as displacement doses generated by neutrons and alpha particles. An example of the analysis method is shown for an experimental austenitic stainless steel containing boride particles and irradiated to 3 and 7 x 10 22 n/cm 2

  19. [Methodology of the description of atmospheric air pollution by nitrogen dioxide by land use regression method in Ekaterinburg].

    Science.gov (United States)

    Antropov, K M; Varaksin, A N

    2013-01-01

    This paper provides the description of Land Use Regression (LUR) modeling and the result of its application in the study of nitrogen dioxide air pollution in Ekaterinburg. The paper describes the difficulties of the modeling for air pollution caused by motor vehicles exhaust, and the ways to address these challenges. To create LUR model of the NO2 air pollution in Ekaterinburg, concentrations of NO2 were measured, data on factors affecting air pollution were collected, a statistical analysis of the data were held. A statistical model of NO2 air pollution (coefficient of determination R2 = 0.70) and a map of pollution were created.

  20. A Simple Method to Measure the Thermal contraction Percentage of a Solid Between Room and Liquid Nitrogen Temperatures

    International Nuclear Information System (INIS)

    Grau Carles, A.; Grau Malonda, A.

    2000-01-01

    We described how to build a simple device for measuring, with a reasonable good accuracy, the thermal contraction of a flat sample between room and liquid nitrogen temperatures. The contraction percentage of the sample is determined by the dimensional comparison of two images taken through the bottom of a transparent quartz tray. Instead of a photo or video camera, a high-resolution flatbed scanner is utilized to avoid the correction of perspectives. The so-called Grueneisen approximation are applied to evaluate the contraction percentages for intermediate temperatures. (Author) 28 refs

  1. The determination of carbon, nitrogen and oxygen in TiCsub(x)Nsub(y)Osub(z) with the Auger electron spectroscopy (AES)

    International Nuclear Information System (INIS)

    Schneider, H.; Nold, E.; Miller, H.T.

    1980-01-01

    The possibility of determining the carbon, nitrogen and oxygen contents in TiCsub(x)Nsub(y)Osub(z) with the Auger-electron-spectroscopy (AES) is discussed. As an example the concentration dependence over the cross section of 1 μm thick TiN-layers is presented. (orig.)

  2. Determination of deuterium in water by a thermometric method

    International Nuclear Information System (INIS)

    Gabicar, J.

    1976-01-01

    A simple and rapid method for the determination of deuterium in water has been developed. The method is based on the change of the thermal effect of the solubility of sodium sulphate in the presence of D 2 O. The procedure is based on the measurement of the temperature of phase transition Na 2 SO 4 . 10 H 2 O reversible Na 2 SO 4 + 10 H 2 O. The sensitivity of the method proposed is comparable with mass spectrometry. (author)

  3. Effects of euthanasia method on stable-carbon and stable-nitrogen isotope analysis for an ectothermic vertebrate.

    Science.gov (United States)

    Atwood, Meredith A

    2013-04-30

    Stable isotope analysis is a critical tool for understanding ecological food webs; however, results can be sensitive to sample preparation methods. To limit the possibility of sample contamination, freezing is commonly used to euthanize invertebrates and preserve non-lethal samples from vertebrates. For destructive sampling of vertebrates, more humane euthanasia methods are preferred to freezing and it is essential to evaluate how these euthanasia methods affect stable isotope results. Stable isotope ratios and elemental composition of carbon and nitrogen were used to evaluate whether the euthanasia method compromised the integrity of the sample for analysis. Specifically, the stable isotope and C:N ratios were compared for larval wood frogs (Rana sylvatica  =  Lithobates sylvaticus), an ectothermic vertebrate, that had been euthanized by freezing with four different humane euthanasia methods: CO2, benzocaine, MS-222 (tricaine methanesulfonate), and 70% ethanol. The euthanasia method was not related to the δ(13)C or δ(15)N values and the comparisons revealed no differences between freezing and any of the other treatments. However, there were slight (non-significant) differences in the isotope ratios of benzocaine and CO2 when each was compared with freezing. The elemental composition was altered by the euthanasia method employed. The percentage nitrogen was higher in CO2 treatments than in freezing, and similar (non-significant) trends were seen for ethanol treatments relative to freezing. The resulting C:N ratios were higher for benzocaine treatments than for both CO2 and ethanol. Similar (non-significant) trends suggested that the C:N ratios were also higher for animals euthanized by freezing than for both CO2 and ethanol euthanasia methods. The euthanasia method had a larger effect on elemental composition than stable isotope ratios. The percentage nitrogen and the subsequent C:N ratios were most affected by the CO2 and ethanol euthanasia methods, whereas

  4. Methods for Determining Organic Matter and Colour in Water

    Directory of Open Access Journals (Sweden)

    Ramunė Albrektienė

    2011-02-01

    Full Text Available The article examines different methods for determining organic matter and colour in water. Most of organic compounds in water have a humic substance. These substances frequently form complexes with iron. Humic matter gives water a yellow-brownish colour. Water filtration through conventional sand filters does not remove colour and organic compounds, and therefore complicated water treatment methods shall be applied. The methods utilized for organic matter determination in water included research on total organic carbon, permanganate index and the bichromate number of UV absorption of 254 nm wave length. The obtained results showed the greatest dependence between water colour and permanganate index. However, UV adsorption could be used for organic matter determination during the operation of a water treatment plant and the start-up of plants as easy and fast methods.Article in Lithuanian

  5. Spatial distribution of soils determines export of nitrogen and dissolved organic carbon from an intensively managed agricultural landscape

    DEFF Research Database (Denmark)

    Wohlfart, T; Exbrayat, J-F; Schelde, Kirsten

    2012-01-01

    nitrogen (TDN), nitrate (NO3−), ammonium nitrogen and dissolved organic carbon (DOC) concentrations were measured, and dissolved organic nitrogen (DON) was calculated for each grabbed sample. Electrical conductivity, pH and flow velocity were measured during sampling. Statistical analyses showed...... significant differences between the northern, southern and converged stream parts, especially for NO3− concentrations with average values between 1.4 mg N l−1 and 9.6 mg N l−1. Furthermore, throughout the sampling period DON concentrations increased to 2.8 mg N l−1 in the northern stream contributing up to 81...

  6. Highly accurate adaptive TOF determination method for ultrasonic thickness measurement

    Science.gov (United States)

    Zhou, Lianjie; Liu, Haibo; Lian, Meng; Ying, Yangwei; Li, Te; Wang, Yongqing

    2018-04-01

    Determining the time of flight (TOF) is very critical for precise ultrasonic thickness measurement. However, the relatively low signal-to-noise ratio (SNR) of the received signals would induce significant TOF determination errors. In this paper, an adaptive time delay estimation method has been developed to improve the TOF determination’s accuracy. An improved variable step size adaptive algorithm with comprehensive step size control function is proposed. Meanwhile, a cubic spline fitting approach is also employed to alleviate the restriction of finite sampling interval. Simulation experiments under different SNR conditions were conducted for performance analysis. Simulation results manifested the performance advantage of proposed TOF determination method over existing TOF determination methods. When comparing with the conventional fixed step size, and Kwong and Aboulnasr algorithms, the steady state mean square deviation of the proposed algorithm was generally lower, which makes the proposed algorithm more suitable for TOF determination. Further, ultrasonic thickness measurement experiments were performed on aluminum alloy plates with various thicknesses. They indicated that the proposed TOF determination method was more robust even under low SNR conditions, and the ultrasonic thickness measurement accuracy could be significantly improved.

  7. Charged particle transport in gaseous nitrogen at intermediate E/N using the voltage transient method

    International Nuclear Information System (INIS)

    Purdie, P.H.; Fletcher, J.

    1992-01-01

    A pulsed swarm of charged particles crossing an inter-electrode gap under the influence of an applied electric field E will produce a pulsed current in the external circuit which, when integrated over time, will result in a transient voltage pulse, the shape and magnitude of which is characteristic of the number of type of charged particles. This voltage transient technique has been used to investigate a gas discharge in nitrogen gas at values of E/N (the ratio of applied electric field to gas number density), such that ionization is non-negligible. The voltage transients have been subjected to a theoretical analysis, which has previously been reported, which includes not only cathode and anode image terms but also both electron and ion diffusion terms. Electron transport parameters are reported for E/N ≤ 350 Td (1 Td = 10 -17 V cm 2 ). Data are also obtained for the drift velocities and diffusion coefficients of the ions operative within the nitrogen discharge. An estimate is obtained for the collisional decay rate of N 2 + . 21 refs., 7 figs

  8. On bankfull methods determination again – why we care?

    Directory of Open Access Journals (Sweden)

    Radecki-Pawlik Artur

    2015-12-01

    Full Text Available One more time we would like to pay attention of especially of the hydraulic engineer audience to bankfull stage and discharge. Along the paper we show commonly accepted definitions of it and ways of calculations. It is difficult to determine the size of the bankfull flow level, that is why the authors are presenting many selected methods. Some of the methods allow the determination of biotic bankfull flow through the occurrence of zones of vegetation characteristic and based on the observation of the occurrence of ground beetles (e.g. the Woodyer and the Radecki-Pawlik and Skalski methods. Some of the methods – most popular- are using morphometric parameters (e.g. the Williams, the Hey and Thorne, the Gauckler-Manning and finally the Lambor methods.

  9. Compartmental modeling with nitrogen-15 to determine effects of degree of fat saturation on intraruminal N recycling.

    Science.gov (United States)

    Oldick, B S; Firkins, J L; Kohn, R A

    2000-09-01

    Two- and three-compartment models were developed to describe N kinetics within the rumen using three Holstein heifers and one nonlactating Holstein cow fitted with ruminal and duodenal cannulas. A 4 x 4 Latin square design included a control diet containing no supplemental fat and diets containing 4.85% of diet dry matter as partially hydrogenated tallow (iodine value = 13), tallow (iodine value = 51), or animal-vegetable fat (iodine value = 110). Effects of fat on intraruminal N recycling and relationships between intraruminal N recycling and ruminal protozoa concentration or the efficiency of microbial protein synthesis were determined. A pulse dose of 15(NH4)2SO4 was introduced into the ruminal NH3 N pool, and samples were taken over time from the ruminal NH3 N and nonammonia N pools. For the three-compartment model, precipitates of nonammonia N after trichloroacetic acid and ethanol extraction were defined as slowly turning over nonammonia N; rapidly turning over nonammonia N was determined by difference. Curves of 15N enrichment were fit to models with two (NH3 N and nonammonia N) or three (NH3 N, rapidly turning over nonammonia N, and slowly turning over nonammonia N) compartments using the software SAAM II. Because the three-compartment model did not remove a small systematic bias or improve the fit of the data, the two-compartment model was used to provide measurements of intraruminal N recycling. Intraruminal NH3 N recycling (45% for control) decreased linearly as fat unsaturation increased (50.2, 43.0, and 41.7% for partially hydrogenated tallow, tallow, and animal-vegetable fat, respectively). Intraruminal nitrogen recycling was not correlated with efficiency of microbial protein synthesis or ruminal protozoa counts.

  10. A novel method for observation by unaided eyes of nitrogen ion tracks and angular distribution in a plasma focus device using 50 Hz–HV electrochemically-etched polycarbonate detectors

    International Nuclear Information System (INIS)

    Sohrabi, M.; Habibi, M.; Roshani, G.H.; Ramezani, V.

    2012-01-01

    A novel ion detection method has been developed and studied in this paper for the first time to detect and observe tracks of nitrogen ions and their angular distribution by unaided eyes in the Amirkabir 4 kJ plasma focus device (PFD). The method is based on electrochemical etching (ECE) of nitrogen ion tracks in 1 mm thick large area polycarbonate (PC) detectors. The ECE method employed a specially designed and constructed large area ECE chamber by applying a 50 Hz–high voltage (HV) generator under optimized ECE conditions. The nitrogen ion tracks and angular distribution were efficiently (constructed for this study) amplified to a point observable by the unaided eyes. The beam profile and angular distribution of nitrogen ion tracks in the central axes of the beam and two- and three-dimensional iso-ion track density distributions showing micro-beam spots were determined. The distribution of ion track density along the central axes versus angular position shows double humps around a dip at the 0° angular positions. The method introduced in this paper proved to be quite efficient for ion beam profile and characteristic studies in PFDs with potential for ion detection studies and other relevant dosimetry applications.

  11. Retention of sulfur and nitrogen oxides from the exhaust gases by radiolysis, a modern method of environmental protection

    International Nuclear Information System (INIS)

    Macarie, Rodica; Zissulescu, Ecaterina; Martin, Diana; Radoiu, Marilena

    2000-01-01

    Industry, especially the power industry, is a great generator of gaseous pollutants (SO x , NO x , CO 2 , CO). The oxides are responsible for the 'acid rains' which have a great negative impact on the environment, human beings and animals, while CO 2 emissions contribute to the increase of the greenhouse effect. Retention of the sulfur and nitrogen oxides from the exhaust gases can be carried out either by conventional methods (using chemical adsorbents) or by non-conventional ones (radiolysis). Recently, non-conventional methods have bee given priority, including exhaust gas irradiation with an accelerated electron beam as a more efficient alternative to the gas desulfurization. In order to increase the efficiency of the accelerated electron beam injected into the exhaust gas, the effect of microwave utilization has been investigated. The company S.C. ICPET S.A.-Bucuresti, in cooperation with INFLPR-Bucuresti, investigated the retention by radiolysis of the sulfur and nitrogen oxides from a synthetic mixture of exhaust gases in an installation developed in the laboratory by means of accelerated electron beams, microwaves and by the accelerated electron beams and microwave combined. The paper presents the results obtained in the laboratory experiments and the advantages of radiolysis in comparison with the chemical conventional methods, namely: simultaneous removal of SO 2 and NO x , solid by-products that can be used as fertilizers in agriculture, simple technologies that do not imply catalysts or adsorbents, no waste waters. (authors)

  12. Phosphorus Use Efficiency for Symbiotic Fixation Nitrogen in Voandzou (Vigna Subterranea) Using Isotopic Exchange Method in Rhizotron

    Energy Technology Data Exchange (ETDEWEB)

    Andriamananjara, A.; Rabeharisoa, L. [Laboratoire des Radio-isotopes, Universite d' Antananarivo, Antananarivo (Madagascar); Masse, D. [Institut de Recherche pour le Developpement, UMR Eco and Sols, Montpellier, (France); Amenc, L.; Pernot, C.; Drevon, J. J. [Institut National de la Recherche Agronomique, UMR Eco and Sols, Montpellier, (France); Morel, C. [INRA-ENITA, Villenave d' Ornon (France)

    2013-11-15

    Low bioavailability of nitrogen and phosphorus is one of the main constraints in the acid soils with high P-fixing capacity. Plants adapt to low nutrient availability through various biological and physico-chemical mechanisms. Since genetic variation of N{sub 2} fixation exists in numerous legume species, optimization of symbiotic nitrogen fixation (SNF) under P deficiency could be a way to the replenishment of soil fertility in tropical soils. As the genetic potential of crops like Vigna subterranea (Bambara groundnut or voandzou) is little studied, although its agronomic potential is interesting for the farmers of Africa, a physiological study through legume screening for N{sub 2} fixation was performed with 54 cultivars from Madagascar, Niger and Mali, inoculated with the reference strain of Bradyrhizobium sp. Vigna CB756 in hydroponic culture under P deficiency and sufficiency (30 and 75 {mu}mol KH{sub 2}PO{sub 4} plant{sup -1} week {sup -1}, respectively), corresponding respectively to 28 and 70 mg P kg{sup -1} of soil. Large variability of nodulation and plant biomass was found among cultivars. These two parameters were generally correlated and the slope of the plant biomass regression as a function of nodulation was considered as an indicator of the efficiency in use of the rhizobial symbiosis. For the two cultivars most tolerant to P deficiency, V1 and V4 from Madagascar, the increase in use efficiency of the rhizobial symbiosis under P deficiency was linked with an increase in nodulated root O{sub 2} consumption linked to N{sub 2} fixation, and in phytase gene expression observed on the nodule sections by in situ RT- PCR. As the complexity of P compartments makes it difficult to assess the P bioavailability in the plant rhizosphere, an isotopic {sup 32}P exchange method was carried out in a rhizotron in order to assess the direct effect of the roots on P mobilization in rhizosphere soil, comparing V1 and V4 with 28 or 70 mg P kg{sup -1} of soil. Throughout

  13. A method for determination of 90Sr in vegetation

    International Nuclear Information System (INIS)

    Nygren, U.

    1998-12-01

    This report describes a method for determination of 90 Sr in vegetation. The method consists of wet-ashing the samples and separating Sr from the sample matrix by oxalate precipitation and extraction chromatography. 90 Y ingrowth is awaited after which Y is separated from Sr and 90 Y measured in a proportional counter. The method has been applied on two reference materials and the 90 Sr results agree well with the recommended values. The method has also been used on 20 samples of blueberry twigs and the mean recovery of Sr was 74%

  14. [Soil carbohydrates: their determination methods and indication functions].

    Science.gov (United States)

    Zhang, Wei; Xie, Hongtu; He, Hongbo; Zheng, Lichen; Wang, Ge

    2006-08-01

    Soil carbohydrates are the important component of soil organic matter, and play an important role in soil aggregation formation. Their hydrolysis methods involve sulfur acid (H2SO4), hydrochloric acid (HCl), and trifluoroacetic acid (TFA) hydrolysis, and their determination methods include colorimetry, gas-liquid chromatography (GLC) , high performance liquid chromatography (HPLC), and high performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD). This paper summarized the methods of carbohydrates' hydrolysis, purification and detection, with focus on the derived methods of GLC, and briefly introduced the indication functions of carbohydrates in soil organic matter turnover.

  15. Validation of histamine determination Method in yoghurt using High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    M Jahedinia

    2014-02-01

    Full Text Available Biogenic amines are organic, basic nitrogenous compounds of low molecular weight that are mainly generated by the enzymatic decarboxylation of amino acids by microorganisms. Dairy products are among the foods with the highest amine content. A wide variety of methods and procedures for determination of histamine and biogenic amines have been established. Amongst, HPLC method is considered as reference method. The aim of this study was to validate Reversed Phase HPLC method determination of histamine in yoghurt. The mobile phase consisted of acetonitrile/water (18:88 v/v and the flow rate was set at 0.5 ml/min using isocratic HPLC. Detection was carried out at 254 nm using UV-detector. Calibration curve that was constructed using peak area of standards was linear and value of correlation coefficient (r2 was estimated at 0.998. Good recoveries were observed for histamine under investigation at all spiking levels and average of recoveries was 84%. The RSD% value from repeatability test was found to be %4.4. Limit of detection and limit of quantitation were 0.14 and 0.42 µ/ml, respectively. The results of validation tests showed that the method is reliable and rapid for quantification of histamine in yoghurt.

  16. Determination of uranium by a gravimetric-volumetric titration method

    International Nuclear Information System (INIS)

    Krtil, J.

    1998-01-01

    A volumetric-gravimetric modification of a method for the determination of uranium based on the reduction of uranium to U (IV) in a phosphoric acid medium and titration with a standard potassium dichromate solution is described. More than 99% of the stoichiometric amount of the titrating solution is weighed and the remainder is added volumetrically by using the Mettler DL 40 RC Memotitrator. Computer interconnected with analytical balances collects continually the data on the analyzed samples and evaluates the results of determination. The method allows to determine uranium in samples of uranium metal, alloys, oxides, and ammonium diuranate by using aliquot portions containing 30 - 100 mg of uranium with the error of determination, expressed as the relative standard deviation, of 0.02 - 0.05%. (author)

  17. New computational methods for determining antikaon-nucleus bound states

    International Nuclear Information System (INIS)

    Fink, P.J. Jr.

    1989-01-01

    Optical potential for antikaon-nucleus strong interactions are constructed using elementary antikaon-nucleus potentials determined previously. The optical potentials are used to determine the existence of a kaon hypernucleus. Modern three dimensional visualization techniques are used to study model dependences, new methods for speeding the calculation of the optical potential are developed, and previous approximation to avoid full Fermi averaging are eliminated. 19 refs., 21 figs., 3 tabs

  18. New method to determine wools and hairs degradation

    OpenAIRE

    Marsal Amenós, Félix

    2013-01-01

    A new method is proposed, validated in the industrial practice, to determine possible bacterial and microbial degradation in textile wools and hairs. It is applied to wools of variable fineness between 18 and 34 microns and to alpaca fibers between 20 and 36 microns. It is based on a dynamometer test to determine tribocharge excision the slivers combed. The rheological behavior of degraded fiber slivers is quite different in the spinning process in addition to the major problems that appear i...

  19. Determination of tin (II) in radiopharmaceutical kits by polarographic method

    International Nuclear Information System (INIS)

    Aungurarat, A.; Thuntawewadthananon, T.

    1996-01-01

    Radiopharmaceutical kit is a diagnostic compound which contains Stannous (II) as a reducing agent. The quantity of Stannous (II) is depended on the type of kits. So the quantity of Stannous (II) is determined by polarographic method with Differential Pulse Voltammetry (D P Mode) in which a saturated calomel electrode is used as anode and a dropping mercury electrode is used as cathode. Both of electrodes are immerged in the premixed solution of supporting electrolyte and analytical Stannous (II). The Stannous (II) is determined by direct method Stannous (II) is analyzed in the form of Stannous; Sn 2 + itself, and indirect method Stannous (II) is analyzed in the form of S tannic; Sn 4+ (Sn 2+ , + N H 4 + ----> Sn 4+ ). Both methods are done at polarographic half wave potential -470 and -520 mV respectively. The Limit of Detection (LOD) of the direct method is 1.9445 micro g and indirect method is 1.3018 micro g. The result received from indirect method is much more accurate than the direct method (Sn 2+ ). The accuracy of the direct method is about 97.5-102.5% recovery

  20. Comparison of digestion methods to determine heavy metals in fertilizers

    Directory of Open Access Journals (Sweden)

    Ygor Jacques Agra Bezerra da Silva

    2014-04-01

    Full Text Available The lack of a standard method to regulate heavy metal determination in Brazilian fertilizers and the subsequent use of several digestion methods have produced variations in the results, hampering interpretation. Thus, the aim of this study was to compare the effectiveness of three digestion methods for determination of metals such as Cd, Ni, Pb, and Cr in fertilizers. Samples of 45 fertilizers marketed in northeastern Brazil were used. A fertilizer sample with heavy metal contents certified by the US National Institute of Standards and Technology (NIST was used as control. The following fertilizers were tested: rock phosphate; organo-mineral fertilizer with rock phosphate; single superphosphate; triple superphosphate; mixed N-P-K fertilizer; and fertilizer with micronutrients. The substances were digested according to the method recommended by the Ministry for Agriculture, Livestock and Supply of Brazil (MAPA and by the two methods 3051A and 3052 of the United States Environmental Protection Agency (USEPA. By the USEPA method 3052, higher portions of the less soluble metals such as Ni and Pb were recovered, indicating that the conventional digestion methods for fertilizers underestimate the total amount of these elements. The results of the USEPA method 3051A were very similar to those of the method currently used in Brazil (Brasil, 2006. The latter is preferable, in view of the lower cost requirement for acids, a shorter digestion period and greater reproducibility.

  1. Using nuclear methods for analyzing materials and determining concentration gradients

    International Nuclear Information System (INIS)

    Darras, R.

    After reviewing the various type of nuclear chemical analysis methods, the possibilities of analysis by activation and direct observation of nuclear reactions are specifically described. These methods make it possible to effect analyses of trace-elements or impurities, even as traces, in materials, with selectivity, accuracy and great sensitivity. This latter property makes them advantageous too for determining major elements in small quantities of available matter. Furthermore, they lend themselves to carrying out superficial analyses and the determination of concentration gradients, given the careful choice of the nature and energy of the incident particles. The paper is illustrated with typical examples of analyses on steels, pure iron, refractory metals, etc [fr

  2. Contribution to determination of coal grindability using Hardgrove method

    OpenAIRE

    Tichánek, František

    2008-01-01

    The paper deals with determination of grindability of coal using Hardgrove method. Some non-availabilities of determination are mentioned as well as factors affecting grindability and relations for conversion of Hardgrove Grindability Index (HGI) values to Bond Work Index (Wi). Paper also provides information on utilization of Hardgrove method in Czech Republic and indicates HGI values for coal from OKD-Karvina region. Příspěvek se zabývá stanovením melitelnosti uhlí pomocí metody Hardgrov...

  3. Rapid spectrographic method for determining microcomponents in solutions

    International Nuclear Information System (INIS)

    Karpenko, L.I.; Fadeeva, L.A.; Gordeeva, A.N.; Ermakova, N.V.

    1984-01-01

    Rapid spectrographic method foe determining microcomponents (Cd, V, Mo, Ni, rare earths and other elements) in industrial and natural solutions has been developed. The analyses were conducted in argon medium and in the air. Calibration charts for determining individual rare earths in solutions are presented. The accuracy of analysis (Sr) was detection limit was 10 -3 -10 -4 mg/ml, that for rare earths - 1.10 -2 mg/ml. The developed method enables to rapidly analyze solutions (sewages and industrialllwaters, wine products) for 20 elements including 6 rare earths, using strandard equipment

  4. Determination of chloride in water. A comparison of three methods

    International Nuclear Information System (INIS)

    Steele, P.J.

    1978-09-01

    The presence of chloride in the water circuits of nuclear reactors, power stations and experimental rigs is undesirable because of the possibility of corrosion. Three methods are considered for the determination of chloride in water in the 0 to 10 μg ml -1 range. The potentiometric method, using a silver-silver chloride electrode, is capable of determining chloride above the 0.1μg ml -1 level, with a standard deviation of 0.03 to 0.12 μg ml -1 in the range 0.1 to 6.0 μg ml -1 chloride. Bromide, iodide and strong reducing agents interfere but none of the cations likely to be present has an effect. The method is very susceptible to variations in temperature. The turbidimetric method involves the production of suspended silver chloride by the addition of silver nitride solution to the sample. The method is somewhat unreliable and is more useful as a rapid, routine limit-testing technique. In the third method, chloride in the sample is pre-concentrated by co-precipitation on lead phosphate, redissolved in acidified ferric nitrate solution and determined colorimetrically by the addition of mercuric thiocyanate solution. It is suitable for determining chloride in the range 0 to 50 μg, using a sample volume of 100 to 500 ml. None of the chemical species likely to be present interferes. In all three methods, chloride contamination can occur at any point in the determination. Analyses should be carried out in conditions where airborne contamination is minimised and a high degree of cleanliness must be maintained. (author)

  5. ANTIOXIDANTS IN FOOD PRODUCTS AND METHODS OF THEIR DETERMINATION

    Directory of Open Access Journals (Sweden)

    S. V. Beltyukova

    2015-06-01

    Full Text Available The content of antioxidants of phenolic type in different types of vegetable raw materials and foodstuff and their influence on a human body is considered. It is shown that for determination of antioxidants chromatographic, electrochemical and spectroscopic methods find application. The broadest application among the chromatographic methods finds method of thin-layer chromatography and HPLC with fluorescent, UF- and mass-spectrometric detectors. Detection limit make 1-10 mkg/ml. From electrochemical methods the cathodic and pulse voltamperometry, amperometric titration find application. These methods differ in high sensitivity, simplicity and selectivity. For the analysis of compound objects the method of a capillary electrophoresis is used, which in some cases allows to exclude a sample preparation stage, and also to carry out definition in wider range of pH values, than in the HPLC method. For the analysis of compound objects the method of a capillary electrophoresis is used, which in some cases allows to exclude a sample preparation stage, and also to carry out definition in wider range of pH values, than in the HPLC method. At the heart of spectroscopic methods, reactions of receiving chromophores generally lie. A sensitive method of definition of polyphenols is hemilyuminestsentny. Recently the sorption-spectroscopic method develops. The method assumes use of own luminescence of ligands as well as sensibilized by an organic ligand a luminescence of ions of Tb (III, as, for example, when determining vanillin, gallic acid, a propilgallat, sum of polyphenolic сompounds. At a choice of a technique of definition of polyphenolic сompounds it is necessary to consider structure of a matrix, selectivity, rapidity, sensitivity of the chosen technique, and also availability of hardware registration.

  6. Nitrogen solubility in nickel base multicomponent melts

    International Nuclear Information System (INIS)

    Bol'shov, L.A.; Stomakhin, A.Ya.; Sokolov, V.M.; Teterin, V.G.

    1984-01-01

    Applicability of various methods for calculation of nitrogen solubility in high-alloyed nickel base alloys, containing Cr, Fe, W, Mo, Ti, Nb, has been estimated. A possibility is shown to use the formUla, derived for the calculation of nitrogen solubility in iron on the basis of statistical theory for a grid model of solution which does not require limitations for the content of a solvent component. The calculation method has been used for nickel alloys, with the concentration of solvent, iron, being accepted equal to zero, and employing parameters of nitrogen interaction as determined for iron-base alloys

  7. Determining Coastal Mean Dynamic Topography by Geodetic Methods

    Science.gov (United States)

    Huang, Jianliang

    2017-11-01

    In geodesy, coastal mean dynamic topography (MDT) was traditionally determined by spirit leveling technique. Advances in navigation satellite positioning (e.g., GPS) and geoid determination enable space-based leveling with an accuracy of about 3 cm at tide gauges. Recent CryoSat-2, a satellite altimetry mission with synthetic aperture radar (SAR) and SAR interferometric measurements, extends the space-based leveling to the coastal ocean with the same accuracy. However, barriers remain in applying the two space-based geodetic methods for MDT determination over the coastal ocean because current geoid modeling focuses primarily on land as a substitute to spirit leveling to realize the vertical datum.

  8. The method of quantitative determination of iodine in acetic acid

    International Nuclear Information System (INIS)

    Sukhomlinov, A.B.; Kalinchenko, N.B.

    1988-01-01

    Method for separate determination of J 2 and J - concentrations in acetic acid is suggested. Iodine concentration in acetic acid is determined by measuring potential of iodine-selective electrode first in the initial solution of acetic acid, where molecular iodine dissociation equals 0.5, and then in acetic acid, with alkali (NaOH) addition up to pH > 3, where molecular iodine dissociation equals 1. Determination is conducted in 5x10 -7 -5x10 -6 mol/l concentration range with relative standard deviation not more than 0.1. 1 fig

  9. Determination of Commercials Cooking Oils and Fats Using Chemometrics Methods

    International Nuclear Information System (INIS)

    Azwan Mat Lazim; Mohd Zuli Jaafar; Phang Wei Shong, P.W.; Suzereen Jamil

    2013-01-01

    In this study, chemometric method has been used in determining the oil quality. The samples used were olive oil, sunflower oil and butter from two different brands. Two different conditions were applied, either it was fresh or fried. Titratio, a conventional method was used to determine free fatty acids content (FFA), iodine value (IV), and peroxide value (PV). Twelve samples were then used for analysis and their FTIR spectra were measured at 4000-400 cm -1 . The computer stimulation was used to process the data based on their pattern recognition which optimized by principal component analysis (PCA) and partial least squares (PLS). PCA model was used to distinguish the properties between fresh and fried oil. The PLS model was used to predict the value for validation test in comparison with conventional results. Results showed the validation value for fresh oil was 0.90. This indicated the chemometric method was in agreement with conventional method. (author)

  10. Effects of farm heterogeneity and methods for upscaling on modelled nitrogen losses in agricultural landscapes

    DEFF Research Database (Denmark)

    Dalgaard, Tommy; Hutchings, Nicholas John; Dragosits, U

    2011-01-01

    The aim of this study is to illustrate the importance of farm scale heterogeneity on nitrogen (N) losses in agricultural landscapes. Results are exemplified with a chain of N models calculating farm-N balances and distributing the N-surplus to N-losses (volatilisation, denitrification, leaching......) and soil-N accumulation/release in a Danish landscape. Possible non-linearities in upscaling are assessed by comparing average model results based on (i) individual farm level calculations and (ii) averaged inputs at landscape level. Effects of the non-linearities that appear when scaling up from farm...... to landscape are demonstrated. Especially in relation to ammonia losses the non-linearity between livestock density and N-loss is significant (p > 0.999), with around 20–30% difference compared to a scaling procedure not taking this non-linearity into account. A significant effect of farm type on soil N...

  11. Further evaluation of creep-fatigue life prediction methods for low-carbon nitrogen-added 316 stainless steel

    International Nuclear Information System (INIS)

    Takahashi, Y.

    1999-01-01

    Low-carbon, medium-nitrogen 316 stainless steel is a principal candidate for a main structural material of a demonstration fast breeder reactor plant in Japan. A number of long-term creep tests and creep-fatigue tests have been conducted for four products of this steel. Two representative creep-fatigue life prediction methods, i.e., time fraction rule and ductility exhaustion method were applied. Total stress relaxation behavior was simulated well by an addition of a viscous strain term to the conventional (primary plus secondary) creep strain, but only the letter was assumed to contribute to creep damage in the ductility exhaustion method. The present ductility exhaustion approach was found to have very good accuracy in creep-fatigue life prediction for all materials tested, while the time fraction rule tended to overpredict failure life as large as a factor of 30. Discussion was made on the reason for this notable difference

  12. Effects of farm heterogeneity and methods for upscaling on modelled nitrogen losses in agricultural landscapes

    Energy Technology Data Exchange (ETDEWEB)

    Dalgaard, T., E-mail: tommy.dalgaard@agrsci.dk [Aarhus University, Department of Agroecology, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Hutchings, N. [Aarhus University, Department of Agroecology, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Dragosits, U. [CEH Edinburgh, Bush Estate, Penicuik, Midlothian EH26 0QB, Scotland (United Kingdom); Olesen, J.E.; Kjeldsen, C. [Aarhus University, Department of Agroecology, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Drouet, J.L.; Cellier, P. [INRA, UMR Environnement et Grandes Cultures, BP 01, 78850 Thiverval-Grignon (France)

    2011-11-15

    The aim of this study is to illustrate the importance of farm scale heterogeneity on nitrogen (N) losses in agricultural landscapes. Results are exemplified with a chain of N models calculating farm-N balances and distributing the N-surplus to N-losses (volatilisation, denitrification, leaching) and soil-N accumulation/release in a Danish landscape. Possible non-linearities in upscaling are assessed by comparing average model results based on (i) individual farm level calculations and (ii) averaged inputs at landscape level. Effects of the non-linearities that appear when scaling up from farm to landscape are demonstrated. Especially in relation to ammonia losses the non-linearity between livestock density and N-loss is significant (p > 0.999), with around 20-30% difference compared to a scaling procedure not taking this non-linearity into account. A significant effect of farm type on soil N accumulation (p > 0.95) was also identified and needs to be included when modelling landscape level N-fluxes and greenhouse gas emissions. - Highlights: > Farm-N balances and the distribution on types of N-losses are modelled for 56 farms. > Farm type significantly affects N-losses and soil-N accumulation. > A non-linear relation between livestock density and ammonia loss is identified. > Approaches for upscaling from farm to landscape level are discussed. > Accounting farm heterogeneity is important when upscaling N-losses. - This study illustrates the importance of including non-linear effects of farm and landscape heterogeneity on the modelling and upscaling of farm nitrogen losses and greenhouse gas emissions in agricultural landscapes.

  13. Effects of farm heterogeneity and methods for upscaling on modelled nitrogen losses in agricultural landscapes

    International Nuclear Information System (INIS)

    Dalgaard, T.; Hutchings, N.; Dragosits, U.; Olesen, J.E.; Kjeldsen, C.; Drouet, J.L.; Cellier, P.

    2011-01-01

    The aim of this study is to illustrate the importance of farm scale heterogeneity on nitrogen (N) losses in agricultural landscapes. Results are exemplified with a chain of N models calculating farm-N balances and distributing the N-surplus to N-losses (volatilisation, denitrification, leaching) and soil-N accumulation/release in a Danish landscape. Possible non-linearities in upscaling are assessed by comparing average model results based on (i) individual farm level calculations and (ii) averaged inputs at landscape level. Effects of the non-linearities that appear when scaling up from farm to landscape are demonstrated. Especially in relation to ammonia losses the non-linearity between livestock density and N-loss is significant (p > 0.999), with around 20-30% difference compared to a scaling procedure not taking this non-linearity into account. A significant effect of farm type on soil N accumulation (p > 0.95) was also identified and needs to be included when modelling landscape level N-fluxes and greenhouse gas emissions. - Highlights: → Farm-N balances and the distribution on types of N-losses are modelled for 56 farms. → Farm type significantly affects N-losses and soil-N accumulation. → A non-linear relation between livestock density and ammonia loss is identified. → Approaches for upscaling from farm to landscape level are discussed. → Accounting farm heterogeneity is important when upscaling N-losses. - This study illustrates the importance of including non-linear effects of farm and landscape heterogeneity on the modelling and upscaling of farm nitrogen losses and greenhouse gas emissions in agricultural landscapes.

  14. Radiometic methods in geologic age determination. 2. rev. ed.

    International Nuclear Information System (INIS)

    Wendt, I.; Schoell, M.

    1986-01-01

    This book is to furnish geoscientists with an overview of the common methods of radiometric age determination, their bases and spheres of application. The first chapters outline the theoretical basis of the procedure in readily understandable form. This presentation omits complicated mathematical derivations in favour of illustrative graphs. The application of the different methods and interpretation of the results are discussed with reference to practical examples. (orig./PW) [de

  15. Spectrochemical method of uranium determination in sea water

    International Nuclear Information System (INIS)

    Koval'chuk, L.I.; Koryukova, V.P.; Andrianov, A.M.

    1979-01-01

    A spectrochemical method of uranium determination in sea water is reported. The method involves the use of hydrated titanium oxide as a concentrator and a substrate for the analysis. The uranium-containing concentrate mixed with carbon powder (1:1) is burned in the alternating current ark (i=15 A) and the spectra are recorded by a diffraction spectrometer. The analytical line of uranium is 2865.14 A. The variation coefficient is 12%

  16. METHODS FOR DETERMINATION AND OPTIMIZATION OF LOGISTICS COSTS

    Directory of Open Access Journals (Sweden)

    Mihaela STET

    2016-12-01

    Full Text Available The paper is dealing with the problems of logistics costs, highlighting some methods for estimation and determination of specific costs for different transport modes in freight distribution. There are highlighted, besides costs of transports, the other costs in supply chain, as well as costing methods used in logistics activities. In this context, there are also revealed some optimization means of transport costs in logistics chain.

  17. METHODS FOR DETERMINATION AND OPTIMIZATION OF LOGISTICS COSTS

    OpenAIRE

    Mihaela STET

    2016-01-01

    The paper is dealing with the problems of logistics costs, highlighting some methods for estimation and determination of specific costs for different transport modes in freight distribution. There are highlighted, besides costs of transports, the other costs in supply chain, as well as costing methods used in logistics activities. In this context, there are also revealed some optimization means of transport costs in logistics chain.

  18. Review on methods for determination of metallothioneins in aquatic organisms.

    Science.gov (United States)

    Shariati, Fatemeh; Shariati, Shahab

    2011-06-01

    One aspect of environmental degradation in coastal areas is pollution from toxic metals, which are persistent and are bioaccumulated by marine organisms, with serious public health implications. A conventional monitoring system of environmental metal pollution includes measuring the level of selected metals in the whole organism or in respective organs. However, measuring only the metal content in particular organs does not give information about its effect at the subcellular level. Therefore, the evaluation of biochemical biomarker metallothionein may be useful in assessing metal exposure and the prediction of potential detrimental effects induced by metal contamination. There are some methods for the determination of metallothioneins including spectrophotometric method, electrochemical methods, chromatography, saturation-based methods, immunological methods, electrophoresis, and RT-PCR. In this paper, different methods are discussed briefly and the comparison between them will be presented.

  19. Preservation Methods Alter Carbon and Nitrogen Stable Isotope Values in Crickets (Orthoptera: Grylloidea).

    Science.gov (United States)

    Jesus, Fabiene Maria; Pereira, Marcelo Ribeiro; Rosa, Cassiano Sousa; Moreira, Marcelo Zacharias; Sperber, Carlos Frankl

    2015-01-01

    Stable isotope analysis (SIA) is an important tool for investigation of animal dietary habits for determination of feeding niche. Ideally, fresh samples should be used for isotopic analysis, but logistics frequently demands preservation of organisms for analysis at a later time. The goal of this study was to establish the best methodology for preserving forest litter-dwelling crickets for later SIA analysis without altering results. We collected two cricket species, Phoremia sp. and Mellopsis doucasae, from which we prepared 70 samples per species, divided among seven treatments: (i) freshly processed (control); preserved in fuel ethanol for (ii) 15 and (iii) 60 days; preserved in commercial ethanol for (iv) 15 and (v) 60 days; fresh material frozen for (vi) 15 and (vii) 60 days. After oven drying, samples were analyzed for δ15N, δ13C values, N(%), C(%) and C/N atomic values using continuous flow isotope ratio mass spectrometry. All preservation methods tested, significantly impacted δ13C and δ15N and C/N atomic values. Chemical preservatives caused δ13C enrichment as great as 1.5‰, and δ15N enrichment as great as 0.9‰; the one exception was M. doucasae stored in ethanol for 15 days, which had δ15N depletion up to 1.8‰. Freezing depleted δ13C and δ15N by up to 0.7 and 2.2‰, respectively. C/N atomic values decreased when stored in ethanol, and increased when frozen for 60 days for both cricket species. Our results indicate that all preservation methods tested in this study altered at least one of the tested isotope values when compared to fresh material (controls). We conclude that only freshly processed material provides adequate SIA results for litter-dwelling crickets.

  20. Preservation Methods Alter Carbon and Nitrogen Stable Isotope Values in Crickets (Orthoptera: Grylloidea.

    Directory of Open Access Journals (Sweden)

    Fabiene Maria Jesus

    Full Text Available Stable isotope analysis (SIA is an important tool for investigation of animal dietary habits for determination of feeding niche. Ideally, fresh samples should be used for isotopic analysis, but logistics frequently demands preservation of organisms for analysis at a later time. The goal of this study was to establish the best methodology for preserving forest litter-dwelling crickets for later SIA analysis without altering results. We collected two cricket species, Phoremia sp. and Mellopsis doucasae, from which we prepared 70 samples per species, divided among seven treatments: (i freshly processed (control; preserved in fuel ethanol for (ii 15 and (iii 60 days; preserved in commercial ethanol for (iv 15 and (v 60 days; fresh material frozen for (vi 15 and (vii 60 days. After oven drying, samples were analyzed for δ15N, δ13C values, N(%, C(% and C/N atomic values using continuous flow isotope ratio mass spectrometry. All preservation methods tested, significantly impacted δ13C and δ15N and C/N atomic values. Chemical preservatives caused δ13C enrichment as great as 1.5‰, and δ15N enrichment as great as 0.9‰; the one exception was M. doucasae stored in ethanol for 15 days, which had δ15N depletion up to 1.8‰. Freezing depleted δ13C and δ15N by up to 0.7 and 2.2‰, respectively. C/N atomic values decreased when stored in ethanol, and increased when frozen for 60 days for both cricket species. Our results indicate that all preservation methods tested in this study altered at least one of the tested isotope values when compared to fresh material (controls. We conclude that only freshly processed material provides adequate SIA results for litter-dwelling crickets.

  1. Effects of Corn Straw Returning and Nitrogen Fertilizer Application Methods on N2O Emission from Wheat Growing Season

    Directory of Open Access Journals (Sweden)

    XU Yu

    2015-12-01

    Full Text Available Based on a wheat field experiment, the effect of four treatments such as no-straw returning (SN, straw returning (SR, control release fertilizer application(SRC and nitrogen drilling(SRR on N2O emission was studied using the static chamber method and the gas chromatographic technique. The results indicated that the wheat field was the sources of N2O emission. The N2O emission peaks followed each time of fertilizer application and irrigation, and usually continued for 1~2 weeks. N2O emissions accounted for more than 40% of total emissions during the N2O emission peak. The amount of N2O emission during three growing stage of wheat from high to low was arranged in turn pre-wintering period, post-wintering period and wintering period. N2O emission could be increased by straw returning. Compared with SN, N2O emission could be enhanced by 48.6% under SR. Both SRC and SRR could decrease the N2O emission, increase wheat yield and economic benefit, especially the latter. Nitrogen drilling is a good method for yield increment and N2O abatement.

  2. Determination of hexamethylmelamine and metabolites in plasma or serum by gas—liquid chromatography with a nitrogen-sensitive detector

    NARCIS (Netherlands)

    Hulshoff, A.; Neijt, J.P.; Smulders, C.F.A.; Loenen, A.C. van; Pinedo, H.M.

    1980-01-01

    A gas chromatographic method for the quantitative determination of hexamethylmelamine (HMM) and five of its metabolites in plasma (or serum) is described. After adjustment of the pH of the plasma sample to about 9.5, the compounds are extracted with chloroform containing 5% of isopropanol. Amyl

  3. Determinants of urea nitrogen production in sepsis. Muscle catabolism, total parenteral nutrition, and hepatic clearance of amino acids.

    Science.gov (United States)

    Pittiruti, M; Siegel, J H; Sganga, G; Coleman, B; Wiles, C E; Placko, R

    1989-03-01

    The major determinants of urea production were investigated in 26 patients with multiple trauma (300 studies). The body clearances (CLRs) of ten amino acids (AAs) were estimated as a ratio of muscle-released AAs plus total parenteral nutrition-infused AAs to their extracellular pool. While clinically septic trauma (ST) patients without multiple-organ failure syndrome (MOFS) had a higher level of urea nitrogen production (25.6 +/- 13.4 g of N per day) compared with nonseptic trauma (NST) patients (14 +/- 7.5 g of N per day) and with ST patients with MOFS (4.28 +/- 1.5 g of N per day), in all groups urea N production was found to be a function of muscle protein degradation (catabolism), total parenteral nutrition-administered AAs, and the ratio between leucine CLR and tyrosine CLR (L/T) (r2 = .82, P less than .0001). Since tyrosine is cleared almost exclusively by the liver, the L/T ratio may be regarded as an index of hepatic function. The significant differences between urea N production in ST and NST patients lay in an increased positive dependence on muscle catabolism and increased negative correlation with L/T in the ST group. At any L/T ratio, urea N production was increased in ST patients over NST patients, but in ST patients with MOFS, it fell to or below levels of NST patients. These data show that the ST process is associated with enhancement of ureagenesis, due to increased hepatic CLR of both exogenous and endogenous AAs. In sepsis with MOFS, a marked inhibition of urea synthesis occurs, partially explained by a decreased hepatic CLR of non-branched-chain AAs.

  4. Determination of the Electronics Charge--Electrolysis of Water Method.

    Science.gov (United States)

    Venkatachar, Arun C.

    1985-01-01

    Presents an alternative method for measuring the electronic charge using data from the electrolysis of acidified distilled water. The process (carried out in a commercially available electrolytic cell) has the advantage of short completion time so that students can determine electron charge and mass in one laboratory period. (DH)

  5. Statistical methods for accurately determining criticality code bias

    International Nuclear Information System (INIS)

    Trumble, E.F.; Kimball, K.D.

    1997-01-01

    A system of statistically treating validation calculations for the purpose of determining computer code bias is provided in this paper. The following statistical treatments are described: weighted regression analysis, lower tolerance limit, lower tolerance band, and lower confidence band. These methods meet the criticality code validation requirements of ANS 8.1. 8 refs., 5 figs., 4 tabs

  6. Simple picrate method for the determination of cyanide in cassava ...

    African Journals Online (AJOL)

    The red coloured complex on the strips was extracted with 50% ethanol solution and the absorbance of the extract was measured at 510nm using a spectrophotometer. The method was reproducible and cyanide as low as 1 microgram could be determined. Cyanide levels of all the cassava varieties tested were higher than ...

  7. A modified method to determine biomass concentration as COD in ...

    African Journals Online (AJOL)

    drinie

    2002-10-04

    Oct 4, 2002 ... A modification of the standard VSS technique was also proposed using two membranes in the filtration device; this technique allowed the biomass determination in 1 μm size bacteria cultures that cannot be detected by the standard VSS method because cells are not retained by the 1.5 μm diameter pore ...

  8. Determinants of long acting and permanent contraceptive methods ...

    African Journals Online (AJOL)

    Introduction: in Ethiopia information on the level of utilization of the long-term and ... determinant factors of long-acting and permanent contraceptive methods use ... 95% CI: 1.46- 4.02), joint fertility related decision (AOR = 6.11, 95% CI: 2.29- ...

  9. Determinants of long acting and permanent contraceptive methods ...

    African Journals Online (AJOL)

    Introduction: In Ethiopia information on the level of utilization of the long term and ... determinant factors of long acting and permanent contraceptive methods use ... number of live children (AOR = 2.42, 95% CI: 1.46- 4.02), joint fertility related ...

  10. A method for determination of the superficial charge density

    International Nuclear Information System (INIS)

    Vila, F.

    1992-10-01

    In this article is presented a new methodism for determination of superficial charge density in nonconducting materials which is based in the combination of laboratory calibrated experiments in conducting surfaces with theoretical calculations for nonconducting surfaces. (author). 19 refs, 7 figs, 1 tab

  11. Novel curcumin–based method of fluoride determination – the ...

    African Journals Online (AJOL)

    Fluoride concentrations above and below certain limits are deleterious to human health, having been implicated in diseases such as fluorosis, arthritis, caries, cancers etc. Better methods of its qualitative and quantitative determination are therefore necessary. A novel, less toxic and more environmentally friendly analytical ...

  12. Alternative method for determining the constant offset in lidar signal

    Science.gov (United States)

    Vladimir A. Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao

    2009-01-01

    We present an alternative method for determining the total offset in lidar signal created by a daytime background-illumination component and electrical or digital offset. Unlike existing techniques, here the signal square-range-correction procedure is initially performed using the total signal recorded by lidar, without subtraction of the offset component. While...

  13. Using container weights to determine irrigation needs: A simple method

    Science.gov (United States)

    R. Kasten Dumroese; Mark E. Montville; Jeremiah R. Pinto

    2015-01-01

    Proper irrigation can reduce water use, water waste, and incidence of disease. Knowing when to irrigate plants in container nurseries can be determined by weighing containers. This simple method is quantifiable, which is a benefit when more than one worker is responsible for irrigation. Irrigation is necessary when the container weighs some target as a proportion of...

  14. A Stability Indicating HPLC Method for the Determination of ...

    African Journals Online (AJOL)

    Erah

    stability indicating reverse phase HPLC method for estimating meloxicam (MLX) in bulk ... acetonitrile-water-glacial acetic acid [55:40:5 (% v/v)] at a flow rate of 1ml/min and detection wavelength .... pore and degassed before use. ... determined to assess the effect of small but ... deviation, the standard error of slope, and the.

  15. Method of 10B determination in biological specimens

    International Nuclear Information System (INIS)

    Nikitina, R.G.; Frolova, E.I.

    1981-01-01

    The paper is concerned with the methods of 10 B determination in biological specimens (blood, skin and tissues of rats). On the basis of investigations conducted there have been proposed films based on cellulose triacetate with optimal characteristics in terms of their possible utilization as solid detectors to record α-particles and recoil nuclei. The conditions of film staining are also discussed

  16. Determination of photooxygenation products of rotenone with isotope dilution method

    International Nuclear Information System (INIS)

    Chubachi, Mitsuo; Hamada, Masayuki

    1975-01-01

    When rotenone dissolved in certain solvent was photochemically oxidized, rotenolones, dehydrorotenone and rotenonone were obtained as main products. In order to determine the quantitative yields of these compounds in photooxygenation products, four compounds mentioned above were labeled with carbon-14 and the isotope dilution method by these labeled compounds was applied to the product analysis. (auth.)

  17. A method for the determination of D(-)-lactic acid

    NARCIS (Netherlands)

    Hamer, C.J.A. van den; Elias, R.W.

    A method for the determination of D(—)-lactic acid is described. An acetone powder from Escherichia coli B in the presence of methylene blue oxidizes D(—)-lactic specifically. Oxygen consumption in a Warburg apparatus was used as a measure of the D(—)-lactic acid.

  18. Advances in the Analytical Methods for Determining the Antioxidant ...

    African Journals Online (AJOL)

    Advances in the Analytical Methods for Determining the Antioxidant Properties of Honey: A Review. M Moniruzzaman, MI Khalil, SA Sulaiman, SH Gan. Abstract. Free radicals and reactive oxygen species (ROS) have been implicated in contributing to the processes of aging and disease. In an effort to combat free radical ...

  19. A Simple UV Spectrophotometric Method for the Determination of ...

    African Journals Online (AJOL)

    The method was also used in the determination of the content of levofloxacin in two commercial brands of levofloxacin in the Nigerian market. Results: The regression data for the calibration plots exhibited good linear relationship (r = 0.999) over a concentration range of 0.25 – 12.0 ìg/ml and the linear regression equation ...

  20. Solid phase extraction method for determination of mitragynine in ...

    African Journals Online (AJOL)

    phase high performance liquid chromatography (RP-HPLC) to determine mitragynine (MG) in rat and human urine, and to investigate the influence of caffeine (CF) on urinary excretion of MG in rats. Methods: A two-dimensional wash-elute ...

  1. Determination of loratadine in pharmaceuticals by a spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Pavalache Georgeta

    2015-06-01

    Full Text Available The spectrophotometric method for determination of loratadine using tetraiodomercurate has been applied in various pharmaceutical formulations. The results confirmed that recovery value is optimum and the method is valid, thus it can be used in quality control and evaluation of loratadine tablets, oral formulations of mixed composition, oral solutions, etc. The method is easy and simple to apply, does not require complicated equipment and spectrophotometric reading time is reduced, which allows a large number of analyzes in a relatively short time.

  2. Improved determination of hadron matrix elements using the variational method

    International Nuclear Information System (INIS)

    Dragos, J.; Kamleh, W.; Leinweber, D.B.; Zanotti, J.M.; Rakow, P.E.L.; Young, R.D.; Adelaide Univ.

    2015-11-01

    The extraction of hadron form factors in lattice QCD using the standard two- and three-point correlator functions has its limitations. One of the most commonly studied sources of systematic error is excited state contamination, which occurs when correlators are contaminated with results from higher energy excitations. We apply the variational method to calculate the axial vector current g A and compare the results to the more commonly used summation and two-exponential fit methods. The results demonstrate that the variational approach offers a more efficient and robust method for the determination of nucleon matrix elements.

  3. Radioimmune method for determination of aldosterone in urine

    International Nuclear Information System (INIS)

    Ignatowska-Switalska, H.

    1976-01-01

    The author describes a radioimmune method for determination of 18-aldosterone glucuronide using a specific aldosterone antibody. The optimal conditions of the test were elaborated and the sensitivity, accuracy and repeatability of the test were established. The normal values of aldosterone excretion determined in 28 healthy subjects on normal sodium diet ranged from 3.3 to 15 μg/24 hours +-3.5. Aldosterone excretion on low-sodium diet increased in the group of healthy controls to 36 μg/24 hours +-21. The usefulness of the method for clinical purposes was illustrated with results of aldosterone determinations in patients with Conn's syndrome, with malignant hypertension and with Addison's disease. (author)

  4. Soil hydrophobicity: comparative study of usual determination methods

    Directory of Open Access Journals (Sweden)

    Eduardo Saldanha Vogelmann

    2015-02-01

    Full Text Available Hydrophobic or water repellent soils slowly absorb water because of the low wett ability of the soil particles which are coated with hydrophobic organic substances. These pose significant effects on plant growth, water infiltration and retention, surface runoff and erosion. The objective of this study was to compare the performance of tension micro-infiltrometer(TMI and the water drop penetration time (WDPT methods in the determination of the hydrophobicity index of eighteen soils from southern Brazil. Soil samples were collected from the 0-5cm soil layer to determine particle size distribution, organic matter content, hydrophobicity index of soil aggregates and droplet penetration time of disaggregated and sieved soil samples. For the TMI method the soil samples were subjected to minor changes due to the use of macroaggregates to preserve the distribution of solid constituents in the soil. Due to the homogeneity of the soil samples the WDPT method gave smaller coefficients of variation unlike the TMI method where the soil structure is preserved. However, both methods had low coefficients of variation, and are thus effective for determining the soil hydrophobicity, especially when the log hydrophobicity index or log WDPT is >1.

  5. Method for Determining Volumetric Efficiency and Its Experimental Validation

    Directory of Open Access Journals (Sweden)

    Ambrozik Andrzej

    2017-12-01

    Full Text Available Modern means of transport are basically powered by piston internal combustion engines. Increasingly rigorous demands are placed on IC engines in order to minimise the detrimental impact they have on the natural environment. That stimulates the development of research on piston internal combustion engines. The research involves experimental and theoretical investigations carried out using computer technologies. While being filled, the cylinder is considered to be an open thermodynamic system, in which non-stationary processes occur. To make calculations of thermodynamic parameters of the engine operating cycle, based on the comparison of cycles, it is necessary to know the mean constant value of cylinder pressure throughout this process. Because of the character of in-cylinder pressure pattern and difficulties in pressure experimental determination, in the present paper, a novel method for the determination of this quantity was presented. In the new approach, the iteration method was used. In the method developed for determining the volumetric efficiency, the following equations were employed: the law of conservation of the amount of substance, the first law of thermodynamics for open system, dependences for changes in the cylinder volume vs. the crankshaft rotation angle, and the state equation. The results of calculations performed with this method were validated by means of experimental investigations carried out for a selected engine at the engine test bench. A satisfactory congruence of computational and experimental results as regards determining the volumetric efficiency was obtained. The method for determining the volumetric efficiency presented in the paper can be used to investigate the processes taking place in the cylinder of an IC engine.

  6. Study on the preparation and stability of uranium carbide samples for the determination of oxygen, hydrogen and nitrogen by fusion under high vacuum

    International Nuclear Information System (INIS)

    Perez Garcia, M.

    1966-01-01

    In view of the high reactivity of uranium carbide, the method employed for the preparation of the sample for the analysis of its gas content: oxygen, hydrogen and nitrogen, has a decisive influence on the analytical results. The variation in the O 2 , H 2 and N 2 content of the uranium carbide has been studied in this paper with the methods utilized for the sample preparation (grinding and cutting). (Author) 9 refs

  7. Method for Determining Optimal Residential Energy Efficiency Retrofit Packages

    Energy Technology Data Exchange (ETDEWEB)

    Polly, B.; Gestwick, M.; Bianchi, M.; Anderson, R.; Horowitz, S.; Christensen, C.; Judkoff, R.

    2011-04-01

    Businesses, government agencies, consumers, policy makers, and utilities currently have limited access to occupant-, building-, and location-specific recommendations for optimal energy retrofit packages, as defined by estimated costs and energy savings. This report describes an analysis method for determining optimal residential energy efficiency retrofit packages and, as an illustrative example, applies the analysis method to a 1960s-era home in eight U.S. cities covering a range of International Energy Conservation Code (IECC) climate regions. The method uses an optimization scheme that considers average energy use (determined from building energy simulations) and equivalent annual cost to recommend optimal retrofit packages specific to the building, occupants, and location. Energy savings and incremental costs are calculated relative to a minimum upgrade reference scenario, which accounts for efficiency upgrades that would occur in the absence of a retrofit because of equipment wear-out and replacement with current minimum standards.

  8. Hemoglobin-catalyzed fluorometric method for the determination of glutathione

    Science.gov (United States)

    Wang, Ruiqiang; Tang, Lin; Li, Hua; Wang, Yi; Gou, Rong; Guo, Yuanyuan; Fang, Yudong; Chen, Fengmei

    2016-01-01

    A new spectrofluorometric method for the determination of glutathione based on the reaction catalyzed by hemoglobin was reported. The reaction product gave a highly fluorescent intensity with the excitation and emission wavelengths of 320.0 nm and 413.0 nm, respectively. The optimum experimental conditions were investigated. Results showed that low concentration glutathione enhanced the fluorescence intensity significantly. The line ranges were 1.0 × 10-6-1.0 × 10-5 mol L-1 of glutathione and 6.0 × 10-10 mol L-1-1.0 × 10-8 mol L-1, respectively. The detection limit was calculated to be 1.1 × 10-11 mol L-1. The recovery test by the standard addition method gave values in the range of 90.78%-102.20%. This method was used for the determination of glutathione in synthetic and real samples with satisfactory results.

  9. Hydrazine determination in presence of uranium by modified spectrophotometric method

    International Nuclear Information System (INIS)

    Velavendan, P.; Pandey, N.K.; Kamachi Mudali, U.; Natarajan, R.

    2011-01-01

    In the present work an indirect, sensitive and accurate method for the determination of hydrazine is described. The method is based on the formation of yellow coloured azine complex by post column derivatization of hydrazine with P-dimethylamino benzaldehyde. The formed yellow coloured complex is stable in acidic medium and has a maximum absorption at 460 nm. Interference due to uranium was studied and the method was applied for the determination of hydrazine in presence of uranium in aqueous stream of nuclear fuel reprocessing. A calibration graph was made for the concentration range of hydrazine from 0.05 ppm to 10 ppm with RSD 0.807% and correlation coefficient of 0.99996. (author)

  10. Apparatus and method for determining solids circulation rate

    Science.gov (United States)

    Ludlow, J Christopher [Morgantown, WV; Spenik, James L [Morgantown, WV

    2012-02-14

    The invention relates to a method of determining bed velocity and solids circulation rate in a standpipe experiencing a moving packed bed flow, such as the in the standpipe section of a circulating bed fluidized reactor The method utilizes in-situ measurement of differential pressure over known axial lengths of the standpipe in conjunction with in-situ gas velocity measurement for a novel application of Ergun equations allowing determination of standpipe void fraction and moving packed bed velocity. The method takes advantage of the moving packed bed property of constant void fraction in order to integrate measured parameters into simultaneous solution of Ergun-based equations and conservation of mass equations across multiple sections of the standpipe.

  11. Residual nitrogen-15 recovery by corn as influenced by tillage and fertilization method

    International Nuclear Information System (INIS)

    Timmons, D.R.; Cruse, R.M.

    1991-01-01

    Tillage systems that create different surface residue conditions may also affect the recovery of residual fertilizer N during subsequent growing seasons. This study evaluated the recovery of residual labeled N fertilizer in the soil by corn (Zea mays L.) for two tillage systems and two fertilization methods. Five atom % 15 N-enriched 28% urea-ammonium nitrate solution (UAN) at 224 kg N ha -1 was either surface-applied in the fall before any primary tillage or banded (knifed in) just before planting in the spring. Continuous corn was grown with either fall moldboard-plow (MP) or ridge-till (RT) systems. After the initial growing season, the recovery of residual labeled N in the soil by corn was determined for three consecutive growing seasons, and the soil profile was sampled periodically to measure residual 15 N in the organic and inorganic pools. One year after labeled UAN application, from 16 to 27% of the initial 15 N applied was found in the organic N pool and only 1% as inorganic N[NH 4 +(NO 2 +NO 3 )-N]. After four seasons, residual 15 N in the organic N pool ranged from 13 to 24%. Less than 0.5% remained as inorganic N. Regression analyses indicated that about 5 kg 15 N ha -1 year -1 became available for both MP and RT systems with banded N, so the amounts were small. Total residual 15 N recovery by corn grain plus stover for three seasons ranged from 1.7 to 3.5%, and was greatest for spring-banded fertilizer. Because the amounts of residual 15 N utilized were too small to affect corn growth, this N source appears to be negligible when considering corn-N needs

  12. Two new methods of determining radon diffusion in fish otoliths

    International Nuclear Information System (INIS)

    Whitehead, N.E.; Ditchburn, R.G.

    1995-01-01

    Otoliths are bony structures found in the ears of fish and used in the 210 Pb/ 226 Ra dating method for age determination. This paper checks the assumption that 222 Rn is not lost from or added to orange roughy fish otoliths by diffusion, which would invalidate the technique. The first method of monitoring diffusion relies on measuring the gamma activity of daughter radionuclides. Otoliths were exposed to an atmosphere enriched in 222 Rn for 10 days, and the supported gamma activity inside them measured allowing for various decay corrections. The calculated radon addition was (0.5 ±0.5)% of the activity of the 226 Ra present. The second method used an alpha spectrometer and attempted to detect 222 Rn directly outguessed from otoliths in the detector vacuum chamber. The results were consistent within errors with those of the first method and showed no loss or gain of 222 Rn, supporting previous estimates of a long life-span for the orange rough y. In contrast it was found that approximately 10% of 222 Rn formed in orange roughy fish scales was lost to an evacuated environment, (hence perhaps to an aqueous environment) and that for this species it could be difficult to base a dating method on analysis of scales. Nevertheless a preliminary minimum age of 57 years was obtained. The methods could be used with non-biological samples to determine 222 Rn diffusion rates. (author). 17 refs., 5 figs

  13. Subcriticality determination of nuclear fuel assembly by Mihalczo method

    International Nuclear Information System (INIS)

    Yamane, Yoshihiro; Watanabe, Shoji; Nishina, Kojiro; Miyoshi, Yoshinori; Suzaki, Takenori; Kobayashi, Iwao.

    1986-01-01

    To establish a technique of on-site subcriticality determination suitable for the criticality safety management of nuclear fuel assembly, the applicability of the method proposed by Mihalczo was examined with the Tank-type Critical Assembly (TCA) of the Japan Atomic Energy Research Institute. In the Mihalczo method, cross power spectral densities and auto power spectral densities are evaluated from the output currents of an ionization chamber containing 252 Cf neutron source and two neutron detectors. The principle of this method is that the spectral ratio formed by the power spectral densities mentioned can be related to the subcriticality by the help of a stochastic theory. Throughout our data processing, an improved formula taking account of the neutron extinction at a detection process was used. Up to the subcriticality of 15 dollars, the Mihalczo method agreed with the water-level worth method, which has been a standard method of reactivity determination at the TCA facility. The systems treated in the present report hold symmetry concerning the nuclear fuel configuration and the 252 Cf chamber position. It was clarified that, contrary to Mihalczo's assertion, the factor converting the spectral ratio to a subcriticality depends on subcriticality itself. (author)

  14. Theoretical investigation of dielectric corona pre-ionization TEA nitrogen laser based on transmission line method

    Science.gov (United States)

    Bahrampour, Alireza; Fallah, Robabeh; Ganjovi, Alireza A.; Bahrampour, Abolfazl

    2007-07-01

    This paper models the dielectric corona pre-ionization, capacitor transfer type of flat-plane transmission line traveling wave transverse excited atmospheric pressure nitrogen laser by a non-linear lumped RLC electric circuit. The flat-plane transmission line and the pre-ionizer dielectric are modeled by a lumped linear RLC and time-dependent non-linear RC circuit, respectively. The main discharge region is considered as a time-dependent non-linear RLC circuit where its resistance value is also depends on the radiated pre-ionization ultra violet (UV) intensity. The UV radiation is radiated by the resistance due to the surface plasma on the pre-ionizer dielectric. The theoretical predictions are in a very good agreement with the experimental observations. The electric circuit equations (including the ionization rate equations), the equations of laser levels population densities and propagation equation of laser intensities, are solved numerically. As a result, the effects of pre-ionizer dielectric parameters on the electrical behavior and output laser intensity are obtained.

  15. System and method for selective catalytic reduction of nitrogen oxides in combustion exhaust gases

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A

    2014-04-08

    A multi-stage selective catalytic reduction (SCR) unit (32) provides efficient reduction of NOx and other pollutants from about 50-550.degree. C. in a power plant (19). Hydrogen (24) and ammonia (29) are variably supplied to the SCR unit depending on temperature. An upstream portion (34) of the SCR unit catalyzes NOx+NH.sub.3 reactions above about 200.degree. C. A downstream portion (36) catalyzes NOx+H.sub.2 reactions below about 260.degree. C., and catalyzes oxidation of NH.sub.3, CO, and VOCs with oxygen in the exhaust above about 200.degree. C., efficiently removing NOx and other pollutants over a range of conditions with low slippage of NH.sub.3. An ammonia synthesis unit (28) may be connected to the SCR unit to provide NH.sub.3 as needed, avoiding transport and storage of ammonia or urea at the site. A carbonaceous gasification plant (18) on site may supply hydrogen and nitrogen to the ammonia synthesis unit, and hydrogen to the SCR unit.

  16. Nonequilibrium shock-heated nitrogen flows using a rovibrational state-to-state method

    Science.gov (United States)

    Panesi, M.; Munafò, A.; Magin, T. E.; Jaffe, R. L.

    2014-07-01

    A rovibrational collisional model is developed to study the internal energy excitation and dissociation processes behind a strong shock wave in a nitrogen flow. The reaction rate coefficients are obtained from the ab initio database of the NASA Ames Research Center. The master equation is coupled with a one-dimensional flow solver to study the nonequilibrium phenomena encountered in the gas during a hyperbolic reentry into Earth's atmosphere. The analysis of the populations of the rovibrational levels demonstrates how rotational and vibrational relaxation proceed at the same rate. This contrasts with the common misconception that translational and rotational relaxation occur concurrently. A significant part of the relaxation process occurs in non-quasi-steady-state conditions. Exchange processes are found to have a significant impact on the relaxation of the gas, while predissociation has a negligible effect. The results obtained by means of the full rovibrational collisional model are used to assess the validity of reduced order models (vibrational collisional and multitemperature) which are based on the same kinetic database. It is found that thermalization and dissociation are drastically overestimated by the reduced order models. The reasons of the failure differ in the two cases. In the vibrational collisional model the overestimation of the dissociation is a consequence of the assumption of equilibrium between the rotational energy and the translational energy. The multitemperature model fails to predict the correct thermochemical relaxation due to the failure of the quasi-steady-state assumption, used to derive the phenomenological rate coefficient for dissociation.

  17. Method of determining the position of an irradiated electron beam

    International Nuclear Information System (INIS)

    Fukuda, Wataru.

    1967-01-01

    The present invention relates to the method of determining the position of a radiated electron beam, in particular, the method of detecting the position of a p-n junction by a novel method when irradiating the electron beam on to the semi-conductor wafer, controlling the position of the electron beam from said junction. When the electron beam is irradiated on to the semi-conductor wafer which possesses the p-n junction, the position of the p-n junction may be ascertained to determine the position of the irradiated electron beam by detecting the electromotive force resulting from said p-n junction with a metal disposed in the proximity of but without mechanical contact with said semi-conductor wafer. Furthermore, as far as a semi-conductor wafer having at least one p-n junction is concerned, the present invention allows said p-n junction to be used to determine the position of an irradiated electron beam. Thus, according to the present invention, the electromotive force of the electron beam resulting from the p-n junction may easily be detected by electrostatic coupling, enabling the position of the irradiated electron beam to be accurately determined. (Masui, R.)

  18. Comparison of the reference mark azimuth determination methods

    Directory of Open Access Journals (Sweden)

    Danijel Šugar

    2013-03-01

    Full Text Available The knowledge of the azimuth of the reference mark is of crucial importance in the determination of the declination which is defined as the ellipsoidal (geodetic azimuth of the geomagnetic meridian. The accuracy of the azimuth determination has direct impact on the accuracy of the declination. The orientation of the Declination-Inclination Magnetometer is usually carried out by sighting the reference mark in two telescope faces in order to improve the reliability of the observations and eliminate some instrumental errors. In this paper, different coordinate as well as azimuth determination methods using GNSS (Global Navigation Satellite System observation techniques within VPPS (High-Precision Positioning Service and GPPS (Geodetic-Precision Positioning Service services of the CROPOS (CROatian POsitioning System system were explained. The azimuth determination by the observation of the Polaris was exposed and it was subsequently compared with the observation of the Sun using hour-angle and zenith-distance method. The procedure of the calculation of the geodetic azimuth from the astronomic azimuth was explained. The azimuth results obtained by different methods were compared and the recommendations on the minimal distance between repeat station and azimuth mark were given. The results shown in this paper were based on the observations taken on the POKU_SV repeat station.

  19. Determining wood chip size: image analysis and clustering methods

    Directory of Open Access Journals (Sweden)

    Paolo Febbi

    2013-09-01

    Full Text Available One of the standard methods for the determination of the size distribution of wood chips is the oscillating screen method (EN 15149- 1:2010. Recent literature demonstrated how image analysis could return highly accurate measure of the dimensions defined for each individual particle, and could promote a new method depending on the geometrical shape to determine the chip size in a more accurate way. A sample of wood chips (8 litres was sieved through horizontally oscillating sieves, using five different screen hole diameters (3.15, 8, 16, 45, 63 mm; the wood chips were sorted in decreasing size classes and the mass of all fractions was used to determine the size distribution of the particles. Since the chip shape and size influence the sieving results, Wang’s theory, which concerns the geometric forms, was considered. A cluster analysis on the shape descriptors (Fourier descriptors and size descriptors (area, perimeter, Feret diameters, eccentricity was applied to observe the chips distribution. The UPGMA algorithm was applied on Euclidean distance. The obtained dendrogram shows a group separation according with the original three sieving fractions. A comparison has been made between the traditional sieve and clustering results. This preliminary result shows how the image analysis-based method has a high potential for the characterization of wood chip size distribution and could be further investigated. Moreover, this method could be implemented in an online detection machine for chips size characterization. An improvement of the results is expected by using supervised multivariate methods that utilize known class memberships. The main objective of the future activities will be to shift the analysis from a 2-dimensional method to a 3- dimensional acquisition process.

  20. 76 FR 21673 - Alternative Efficiency Determination Methods and Alternate Rating Methods

    Science.gov (United States)

    2011-04-18

    ... EERE-2011-BP-TP-00024] RIN 1904-AC46 Alternative Efficiency Determination Methods and Alternate Rating Methods AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of... and data related to the use of computer simulations, mathematical methods, and other alternative...

  1. Nitrogen and protein contents in some aquatic plant species

    Directory of Open Access Journals (Sweden)

    Krystyna Bytniewska

    2015-01-01

    Full Text Available Nitrogen and protein contents in higher aquatic plants deriving from a natural habitat were determined. The following plants were examined: Spirodela polyrrhiza (L. Schleid., Elodea canadensis Rich., Riccia fluitans L. Total nitrogen and nitrogen of respective fractions were determined by the Kjeldahl method. Nitrogen compounds were fractionated according to Thimann et al. Protein was extracted after Fletcher and Osborne and fractionated after Osborne. It was found, that total protein content in the plants under examination constitutes 18 to 25%o of dry matter. Albumins and glutelins are the most abundant protein fractions.

  2. Radioanalytical method to determine contaminations due to packaging materials

    International Nuclear Information System (INIS)

    Figge, K.

    1976-01-01

    The quantitative determination of the transfer of substances in the system packaging material/foodstuff is essential for the protection of consumer and with respect to food regulations. With the help of the radio tracer techniques described it is possible to determine the migration of an individual component of the packaging material into liquid and solid foodstuffs or their simulants. Parts of the radioactive test films or sheets are brought in one- or two-sided contact with the foodstuffs or their simulants using newly developed extraction and migration cells. The extracted or migrated amounts of the packaging material component are calculated from the radioactivities migrated into the contact media under the test conditions given. As an example for the application of these radio tracer techniques, investigations into the migration behaviour of the organotin stabilizer di-n-octyltin-2-ethyl-hexyl-dithioglycolate in the system rigid PVC/edible fat or test fat respectively are described. For the determination of the total components migrating from a packaging material into foodstuffs, a radio tracer method was developed making use of a 14 C-labelled standard triglyceride mixture - the fat simulant HB 307- 14 C. The efficiency of this method is demonstrated by determinations of the global migrates of polyvinylchloride films containing different amounts of platicizers and the mean error of the single determination on the amount of global migrate is discussed. (T.G.)

  3. Ambit determination method in estimating rice plant population density

    Directory of Open Access Journals (Sweden)

    Abu Bakar, B.,

    2017-11-01

    Full Text Available Rice plant population density is a key indicator in determining the crop setting and fertilizer application rate. It is therefore essential that the population density is monitored to ensure that a correct crop management decision is taken. The conventional method of determining plant population is by manually counting the total number of rice plant tillers in a 25 cm x 25 cm square frame. Sampling is done by randomly choosing several different locations within a plot to perform tiller counting. This sampling method is time consuming, labour intensive and costly. An alternative fast estimating method was developed to overcome this issue. The method relies on measuring the outer circumference or ambit of the contained rice plants in a 25 cm x 25 cm square frame to determine the number of tillers within that square frame. Data samples of rice variety MR219 were collected from rice plots in the Muda granary area, Sungai Limau Dalam, Kedah. The data were taken at 50 days and 70 days after seeding (DAS. A total of 100 data samples were collected for each sampling day. A good correlation was obtained for the variety of 50 DAS and 70 DAS. The model was then verified by taking 100 samples with the latching strap for 50 DAS and 70 DAS. As a result, this technique can be used as a fast, economical and practical alternative to manual tiller counting. The technique can potentially be used in the development of an electronic sensing system to estimate paddy plant population density.

  4. Transfer Efficiency and Cooling Cost by Thermal Loss based on Nitrogen Evaporation Method for Superconducting MAGLEV System

    International Nuclear Information System (INIS)

    Chung, Y D; Kim, D W; Lee, C Y

    2017-01-01

    This paper presents the feasibility of technical fusion between wireless power transfer (WPT) and superconducting technology to improve the transfer efficiency and evaluate operating costs such as refrigerant consumption. Generally, in WPT technology, the various copper wires have been adopted. From this reason, the transfer efficiency is limited since the copper wires of Q value are intrinsically critical point. On the other hand, as superconducting wires keep larger current density and relatively higher Q value, the superconducting resonance coil can be expected as a reasonable option to deliver large transfer power as well as improve the transfer ratio since it exchanges energy at a much higher rate and keeps stronger magnetic fields out. However, since superconducting wires should be cooled indispensably, the cooling cost of consumed refrigerant for resonance HTS wires should be estimated. In this study, the transmission ratios using HTS resonance receiver (Rx) coil and various cooled and noncooled copper resonance Rx coils were presented under non cooled copper antenna within input power of 200 W of 370 kHz respectively. In addition, authors evaluated cooling cost of liquid nitrogen for HTS resonance coil and various cooled copper resonance coils based on nitrogen evaporation method. (paper)

  5. Transfer Efficiency and Cooling Cost by Thermal Loss based on Nitrogen Evaporation Method for Superconducting MAGLEV System

    Science.gov (United States)

    Chung, Y. D.; Kim, D. W.; Lee, C. Y.

    2017-07-01

    This paper presents the feasibility of technical fusion between wireless power transfer (WPT) and superconducting technology to improve the transfer efficiency and evaluate operating costs such as refrigerant consumption. Generally, in WPT technology, the various copper wires have been adopted. From this reason, the transfer efficiency is limited since the copper wires of Q value are intrinsically critical point. On the other hand, as superconducting wires keep larger current density and relatively higher Q value, the superconducting resonance coil can be expected as a reasonable option to deliver large transfer power as well as improve the transfer ratio since it exchanges energy at a much higher rate and keeps stronger magnetic fields out. However, since superconducting wires should be cooled indispensably, the cooling cost of consumed refrigerant for resonance HTS wires should be estimated. In this study, the transmission ratios using HTS resonance receiver (Rx) coil and various cooled and noncooled copper resonance Rx coils were presented under non cooled copper antenna within input power of 200 W of 370 kHz respectively. In addition, authors evaluated cooling cost of liquid nitrogen for HTS resonance coil and various cooled copper resonance coils based on nitrogen evaporation method.

  6. Liquid chromatography method to determine polyamines in thermosetting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Dopico-Garcia, M.S. [Laboratorio de Quimica - Centro de Investigacions Tecnoloxicas, Universidade da Coruna, Campus de Esteiro s/n, 15403 Ferrol (Spain); Centro Galego do Plastico, A Cabana s/n, 15590 Ferrol (Spain); Lopez-Vilarino, J.M. [Laboratorio de Quimica - Centro de Investigacions Tecnoloxicas, Universidade da Coruna, Campus de Esteiro s/n, 15403 Ferrol (Spain); Fernandez-Martinez, G. [Unidad de Tecnicas Cromatograficas, Servizos de Apoio a Investigacion, Edificio Servizos Centrais de Investigacion, Universidade da Coruna, Campus de Elvina s/n, 15071 A Coruna (Spain); Gonzalez-Rodriguez, M.V., E-mail: victoria@udc.es [Dpto. de Quimica Analitica - E.U. Politecnica, Universidade da Coruna, Avda. 19 de Febrero s/n, 15405 Ferrol (Spain)

    2010-05-14

    A simple, robust and sensitive analytical method to determine three polyamines commonly used as hardeners in epoxy resin systems and in the manufacture of polyurethane is reported. The studied polyamines are: one tetramine, TETA (triethylenetetramine), and two diamines, IPDA (Isophorone diamine) and TCD-diamine (4,7-methano-1H-indene-5,?-dimethanamine, octahydro-). The latter has an incompletely defined structure, and, as far as we know, has not been previously determined by other methods. All three polyamines contain primary amines; TETA also contains secondary amines. The analytical method involves derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, used for the first time for these compounds, followed by high performance liquid chromatography (HPLC) analysis with a fluorescence (FL) detector ({lambda} excitation 248 nm, {lambda} emision 395 nm). The HPLC-DAD-LTQ Orbitrap MS was used in order to provide structural information about the obtained derivatized compounds. The hybrid linear ion trap LTQ Orbitrap mass spectrometer has been introduced in recent years and provides a high mass accuracy. The structures of the derivatized analytes were identified from the protonated molecular ions [M+H]{sup +} and corresponded to the fully labelled analytes. The following analytical parameters were determined for the method using the HPLC-FL: linearity, precision (2.5-10%), instrumental precision intraday (0.8-1.5%) and interday (2.9-6.3%), and detection limits (0.02-0.14 mg L{sup -1}). The stability of stock solutions and derivatized compounds was also investigated. The method was applied to determine the amine free content in epoxy resin dust collected in workplaces.

  7. Liquid chromatography method to determine polyamines in thermosetting polymers.

    Science.gov (United States)

    Dopico-García, M S; López-Vilariño, J M; Fernández-Martínez, G; González-Rodríguez, M V

    2010-05-14

    A simple, robust and sensitive analytical method to determine three polyamines commonly used as hardeners in epoxy resin systems and in the manufacture of polyurethane is reported. The studied polyamines are: one tetramine, TETA (triethylenetetramine), and two diamines, IPDA (Isophorone diamine) and TCD-diamine (4,7-methano-1H-indene-5,?-dimethanamine, octahydro-). The latter has an incompletely defined structure, and, as far as we know, has not been previously determined by other methods. All three polyamines contain primary amines; TETA also contains secondary amines. The analytical method involves derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, used for the first time for these compounds, followed by high performance liquid chromatography (HPLC) analysis with a fluorescence (FL) detector (lambda excitation 248nm, lambda emision 395nm). The HPLC-DAD-LTQ Orbitrap MS was used in order to provide structural information about the obtained derivatized compounds. The hybrid linear ion trap LTQ Orbitrap mass spectrometer has been introduced in recent years and provides a high mass accuracy. The structures of the derivatized analytes were identified from the protonated molecular ions [M+H](+) and corresponded to the fully labelled analytes. The following analytical parameters were determined for the method using the HPLC-FL: linearity, precision (2.5-10%), instrumental precision intraday (0.8-1.5%) and interday (2.9-6.3%), and detection limits (0.02-0.14mgL(-1)). The stability of stock solutions and derivatized compounds was also investigated. The method was applied to determine the amine free content in epoxy resin dust collected in workplaces. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Liquid chromatography method to determine polyamines in thermosetting polymers

    International Nuclear Information System (INIS)

    Dopico-Garcia, M.S.; Lopez-Vilarino, J.M.; Fernandez-Martinez, G.; Gonzalez-Rodriguez, M.V.

    2010-01-01

    A simple, robust and sensitive analytical method to determine three polyamines commonly used as hardeners in epoxy resin systems and in the manufacture of polyurethane is reported. The studied polyamines are: one tetramine, TETA (triethylenetetramine), and two diamines, IPDA (Isophorone diamine) and TCD-diamine (4,7-methano-1H-indene-5,?-dimethanamine, octahydro-). The latter has an incompletely defined structure, and, as far as we know, has not been previously determined by other methods. All three polyamines contain primary amines; TETA also contains secondary amines. The analytical method involves derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate, used for the first time for these compounds, followed by high performance liquid chromatography (HPLC) analysis with a fluorescence (FL) detector (λ excitation 248 nm, λ emision 395 nm). The HPLC-DAD-LTQ Orbitrap MS was used in order to provide structural information about the obtained derivatized compounds. The hybrid linear ion trap LTQ Orbitrap mass spectrometer has been introduced in recent years and provides a high mass accuracy. The structures of the derivatized analytes were identified from the protonated molecular ions [M+H] + and corresponded to the fully labelled analytes. The following analytical parameters were determined for the method using the HPLC-FL: linearity, precision (2.5-10%), instrumental precision intraday (0.8-1.5%) and interday (2.9-6.3%), and detection limits (0.02-0.14 mg L -1 ). The stability of stock solutions and derivatized compounds was also investigated. The method was applied to determine the amine free content in epoxy resin dust collected in workplaces.

  9. Method for rapidly determining a pulp kappa number using spectrophotometry

    Science.gov (United States)

    Chai, Xin-Sheng; Zhu, Jun Yong

    2002-01-01

    A system and method for rapidly determining the pulp kappa number through direct measurement of the potassium permanganate concentration in a pulp-permanganate solution using spectrophotometry. Specifically, the present invention uses strong acidification to carry out the pulp-permanganate oxidation reaction in the pulp-permanganate solution to prevent the precipitation of manganese dioxide (MnO.sub.2). Consequently, spectral interference from the precipitated MnO.sub.2 is eliminated and the oxidation reaction becomes dominant. The spectral intensity of the oxidation reaction is then analyzed to determine the pulp kappa number.

  10. Modified use of Van de Meer method for luminosity determination

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1975-01-01

    Modifications are suggested which should improve the accuracy of the Van de Meer method of determining beam luminosity at the CERN ISR. Four bending magnets would be inserted between the quadrupoles of a given experimental straight section, connected in series, and shimmed so that the machine parameters are not affected. The magnets would be driven with a zigzag current power supply with a uniform rate of current change. Experiments requiring accurate luminosity determination would be run while the deflection magnets are being driven with the oscillatory current pattern. (U.S.)

  11. Radioimmunoassay method for the determination of cardiotonic glycosides

    International Nuclear Information System (INIS)

    1975-01-01

    A kit method for the in vitro determination of digoxin and digitoxin is described. The blood serum is mixed with the reagent which consists of an aqueous buffer solution containing a radiolabeled hapten for the glycoside. Antiserum with specific antibodies is added and the mixture is incubated. Thereafter, a thin strip of membrane mainly consisting of an ionexchanger is brought into contact with the mixture to separate the antibody bound hapten from the unbound hapten. The ratios of both are determined by counting the radioactive hapten

  12. Age determination of paintings by 210Pb method

    International Nuclear Information System (INIS)

    Gilot, E.; Apers, D.

    1977-01-01

    Often the 210 Pb method for age determination of paintings is inoperative because the initial 210 Pb activity of undated lead oxide cannot be determined. This difficulty could be removed if the ores could be identified from which the lead white was prepared. It would be possible to measure the initial 210 Pb activity directly in Pb ores or in identical Pb oxides from properly dated pictures. Some results show that Pb ores can be identified by the isotope ratios 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, 208 Pb/ 204 Pb. A systematic study of Pb ores and pigment isotopic composition is necessary. (author)

  13. Diffractometric method for determining the degree of crystallinity of materials

    Energy Technology Data Exchange (ETDEWEB)

    Chukhchin, D. G., E-mail: dimatsch@mail.ru; Malkov, A. V.; Tyshkunova, I. V.; Mayer, L. V.; Novozhilov, E. V. [Lomonosov Northen (Arctic) Federal University (Russian Federation)

    2016-05-15

    A new method for determining the degree of crystallinity of a material from X-ray diffraction data has been developed. The method is based on estimating the rate of change in function I = f(2θ) in the entire range of scattering angles. A calculation is performed using the ratio of the integral modulus of the first derivative of intensity with respect to angle 2θ to the integral area under the diffraction pattern curve. The method was tested on two substances with known amorphous and crystalline components. A linear relationship is revealed between the specified ratio of crystalline and amorphous parts and the calculated crystallinity index. The proposed method allows one to estimate impartially and compare the degree of crystallinity for samples of different nature.

  14. Determination of lisinopril in pharmaceuticals by a kinetic spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Čakar Mira

    2012-01-01

    Full Text Available A kinetic spectrophotometric method for determination of lisinopril in pharmaceuticals has been developed. The method is based on activator action of lisinopril on Cu(II ions catalysing the oxidation of nile blue A with hydrogen peroxide in borate buffer (pH 9.3. A decrease of the absorbance was recorded at 635 nm for 5 min at 25°C. The linearity was established applying the tangent method within the concentration range of lisinopril from 0.8-6.4 μg mL-1, the detection and quantification limits being 0.158 μg mL-1 and 0.480 μg mL-1, respectively. The method has been successfully applied in three brands of tablets containing lisinopril alone or in combination with hydrochlorothiazide.

  15. Comparative study of methods for potential and actual evapotranspiration determination

    International Nuclear Information System (INIS)

    Kolev, B.

    2004-01-01

    Two types of methods for potential and actual evapotranspiration determining were compared. The first type includes neutron gauge, tensiometers, gypsum blocks and lysimeters. The actual and potential evapotranspiration were calculated by water balance equation. The second type of methods used a simulation model for all calculation. The aim of this study was not only to compare and estimate the methods using. It was mainly pointed on calculations of water use efficiency and transpiration coefficient in potential production situation. This makes possible to choose the best way for water consumption optimization for a given crop. The final results find with the best of the methods could be used for applying the principles of sustainable agriculture in random region of Bulgarian territory. (author)

  16. Nitrogen-doping effects on the growth, structure and electrical performance of carbon nanotubes obtained by spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Ionescu, Mihnea Ioan; Zhang Yong; Li Ruying [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada); Abou-Rachid, Hakima [Defense Research and Development Canada - Valcartier, 2459 Boulevard PieXI Nord, Quebec, QC G3J 1X5 (Canada); Sun Xueliang, E-mail: xsun@eng.uwo.ca [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada)

    2012-03-01

    Vertically aligned nitrogen-doped carbon nanotubes (CNTs) with modulated nitrogen content have been synthesized in a large scale by using spray pyrolysis chemical vapor deposition technique. The effects of nitrogen doping on the growth, structure and electrical performance of carbon nanotubes have been systematically examined. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman techniques have been employed to characterize the morphology, composition, and vibrational properties of nanotubes. The results indicate that the nitrogen incorporation significantly influences the growth rate, morphology, size and structure of nanotubes. Electrical measurement investigation of the nanotubes indicates that the change in electrical resistance increases with temperature and pressure as the nitrogen concentration increases inside the tubes. This work presents a versatile, safe, and easy way to scale up route of growing carbon nanotubes with controlled nitrogen content and modulated structure, and may provide an insight in developing various nitrogen-doped carbon-based nanodevices.

  17. Determination of Impurities in Aluminum Alloy by INAA Single Comparator Method (K0-Standardization Method)

    International Nuclear Information System (INIS)

    Sarheel, A.; Khamis, I.; Somel, N.

    2007-01-01

    Multielement determination by the k0 based INAA using k0-IAEA program has been performed at Syrian Atomic Energy Commission using alloys. Concentrations of Cu, Zn, Fe, Ni, Sn and Ti in addition to aluminum element were determined in an aluminum alloy and Ni, Cr, Mo were determined in dental alloys using INAA k0-standardization method. Al-0.1%Au, Ni and Zn certified reference materials were analyzed to assess the suitability and accuracy of the method. Elements were determined in reference materials and samples after short and long irradiations, according to element half-lives.

  18. Characterisation and quantification of organic phosphorus and organic nitrogen components in aquatic systems: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Worsfold, Paul J. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom)], E-mail: pworsfold@plymouth.ac.uk; Monbet, Philippe [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom); Water Studies Centre, School of Chemistry, Monash University, Clayton 3800, Victoria (Australia); Tappin, Alan D.; Fitzsimons, Mark F.; Stiles, David A. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL48AA (United Kingdom); McKelvie, Ian D. [Water Studies Centre, School of Chemistry, Monash University, Clayton 3800, Victoria (Australia)

    2008-08-22

    This review provides a critical assessment of knowledge regarding the determination of organic phosphorus (OP) and organic nitrogen (ON) in aquatic systems, with an emphasis on biogeochemical considerations and analytical challenges. A general background on organic phosphorus and organic nitrogen precedes a discussion of sample collection, extraction, treatment/conditioning and preconcentration of organic phosphorus/nitrogen from sediments, including suspended particulate matter, and waters, including sediment porewaters. This is followed by sections on the determination of organic phosphorus/nitrogen components. Key techniques covered for organic phosphorus components are molecular spectrometry, atomic spectrometry and enzymatic methods. For nitrogen the focus is on the measurement of total organic nitrogen concentrations by carbon hydrogen nitrogen analysis and high temperature combustion, and organic nitrogen components by gas chromatography, high-performance liquid chromatography, gel electrophoresis, mass spectrometry, nuclear magnetic resonance spectrometry, X-ray techniques and enzymatic methods. Finally future trends and needs are discussed and recommendations made.

  19. Optical methods for microstructure determination of doped samples

    Science.gov (United States)

    Ciosek, Jerzy F.

    2008-12-01

    The optical methods to determine refractive index profile of layered materials are commonly used with spectroscopic ellipsometry or transmittance/reflectance spectrometry. Measurements of spectral reflection and transmission usually permit to characterize optical materials and determine their refractive index. However, it is possible to characterize of samples with dopants, impurities as well as defects using optical methods. Microstructures of a hydrogenated crystalline Si wafer and a layer of SiO2 - ZrO2 composition are investigated. The first sample is a Si(001):H Czochralski grown single crystalline wafer with 50 nm thick surface Si02 layer. Hydrogen dose implantation (D continue to be an important issue in microelectronic device and sensor fabrication. Hydrogen-implanted silicon (Si: H) has become a topic of remarkable interest, mostly because of the potential of implantation-induced platelets and micro-cavities for the creation of gettering -active areas and for Si layer splitting. Oxygen precipitation and atmospheric impurity are analysed. The second sample is the layer of co-evaporated SiO2 and ZrO2 materials using simultaneously two electron beam guns in reactive evaporation methods. The composition structure was investigated by X-Ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry methods. A non-uniformity and composition of layer are analysed using average density method.

  20. Indirect methods for reference interval determination - review and recommendations.

    Science.gov (United States)

    Jones, Graham R D; Haeckel, Rainer; Loh, Tze Ping; Sikaris, Ken; Streichert, Thomas; Katayev, Alex; Barth, Julian H; Ozarda, Yesim

    2018-04-19

    Reference intervals are a vital part of the information supplied by clinical laboratories to support interpretation of numerical pathology results such as are produced in clinical chemistry and hematology laboratories. The traditional method for establishing reference intervals, known as the direct approach, is based on collecting samples from members of a preselected reference population, making the measurements and then determining the intervals. An alternative approach is to perform analysis of results generated as part of routine pathology testing and using appropriate statistical techniques to determine reference intervals. This is known as the indirect approach. This paper from a working group of the International Federation of Clinical Chemistry (IFCC) Committee on Reference Intervals and Decision Limits (C-RIDL) aims to summarize current thinking on indirect approaches to reference intervals. The indirect approach has some major potential advantages compared with direct methods. The processes are faster, cheaper and do not involve patient inconvenience, discomfort or the risks associated with generating new patient health information. Indirect methods also use the same preanalytical and analytical techniques used for patient management and can provide very large numbers for assessment. Limitations to the indirect methods include possible effects of diseased subpopulations on the derived interval. The IFCC C-RIDL aims to encourage the use of indirect methods to establish and verify reference intervals, to promote publication of such intervals with clear explanation of the process used and also to support the development of improved statistical techniques for these studies.

  1. Methods of Selenium Supplementation: Bioavailability and Determination of Selenium Compounds.

    Science.gov (United States)

    Bodnar, Malgorzata; Szczyglowska, Marzena; Konieczka, Piotr; Namiesnik, Jacek

    2016-01-01

    Selenium, a "dual-surface" element, maintains a very thin line between a level of necessity and harmfulness. Because of this, a deficiency or excess of this element in an organism is dangerous and causes health-related problems, both physically and mentally. The main source of selenium is a balanced diet, with a proper selection of meat and plant products. Meanwhile, the proper assimilation of selenium into these products depends on their bioavailability, bioaccessibility, and/or bioactivity of a given selenium compound. From the time when it was discovered that selenium and its compounds have a significant influence on metabolic processes and in many countries throughout the world, a low quantity of selenium was found in different parts of the environment, pressure was put upon an effective and fast method of supplementing the environment with the help of selenium. This work describes supplementation methods applied with the use of selenium, as well as new ideas for increasing the level of this element in various organisms. Based on the fact that selenium appears in the environment at trace levels, the determination of total amount of selenium or selenium speciation in a given sample demands the selection of appropriate measurement methods. These methods are most often comprised of a sample preparation technique and/or a separation technique as well as a detection system. The work presents information on the subject of analytical methods used for determining selenium and its compounds as well as examples in literature of their application.

  2. Study of the determination method of the river dispersion coefficient

    International Nuclear Information System (INIS)

    Carvalho, M.A.G. de.

    1982-01-01

    An application of the method introduced by 'Fischer, H.B. - 1968 - Dispersion prediction in natural streams Journal of the Sanitary Engineering Division, ACSE, vol. 94 n 5A5. Proc. Paper 6169 pp 927-943.', for the calculation of the dispersion coefficient, based on Taylor's model is made. The aim is to develop a method which avoids the necessity of having an instantaneous impulse at the entrance section (1st section) of the system being measured. The dispersion coefficient is determined by curve fitting the experimental response in the 2nd secton and that obtained with the model by means of the non-linear least-squares method. The same method is applied with the residence time distribution function. The theoretical differences between these two function and their results are discussed. By adjusting the two model parameters in all these calculations, the dispersion coefficient and the mean velocity are determined, simultaneously. A comparison between the moment's method and Fischer's formulation is also done using the same experimental data. (E.G.) [pt

  3. Fertilizer nitrogen prescription for cotton by 15N recovery method under integrated nutrient management using soil test crop response function

    International Nuclear Information System (INIS)

    Arulmozhiselvan, K.; Govindaswamy, M.; Chellamuthu, S.

    2007-01-01

    Fertilizer efficiency is a vital parameter in prescription functions to compute fertilizer requirements of crops for achieving a specific yield target. In Soil Test Crop Response (STCR) function, nitrogen fertilizer efficiency is calculated by Apparent N Recovery (ANR) method, which includes the effect of added N interaction (ANI) on soil N reserves. In order to exclude soil effect and refine STCR function, the real efficiency of fertilizer N was estimated by 15 N recovery method. By fitting 15 N recovery in the function, the fertilizer N required for a specific yield target of cotton was estimated. The estimated N requirement by 15 N recovery method was lesser than ANR method when available soil N relatively increased. The approach also fine-tuned the N contributing efficiency of soil, farmyard manure and Azospirillum under Integrated Nutrient Management (INM). For achieving 25 q of seed cotton yield in a soil having 220 kg of available N ha -1 , the predicted N requirement was 159 kg ha -1 under ANR method, whereas in 15 N recovery method fertilizer N to be applied was 138 kg ha -1 with urea alone and 79 kg ha -1 with urea + FYM + Azospirillum. (author)

  4. Albedo's determination by the method of neutron impulse

    International Nuclear Information System (INIS)

    Flores Calderon, J.E.

    1982-01-01

    Experiments with non-stationary neutron transport in large cavity moderators (l>>Σsub(tr) -1 ) (where l is the characteristic cavity length and Σsub(tr) -1 the macroscopic transport section of the moderator) led to the method reported in this study which, based on neutron impulses for determining albedo of thermal neutrons, gave a precision greater by an order of magnitude over previous methods. A sufficient time interval after introduction of the neutron flux into the moderator chamber decreased exponentially the decay constant L, which was itself related to albedo by a function called f. Numerical calculations of albedo were assisted. (author)

  5. Determination of material irradiation parameters. Required accuracies and available methods

    International Nuclear Information System (INIS)

    Cerles, J.M.; Mas, P.

    1978-01-01

    In this paper, the author reports some main methods to determine the nuclear parameters of material irradiation in testing reactor (nuclear power, burn-up, fluxes, fluences, ...). The different methods (theoretical or experimental) are reviewed: neutronics measurements and calculations, gamma scanning, thermal balance, ... The required accuracies are reviewed: they are of 3-5% on flux, fluences, nuclear power, burn-up, conversion factor, ... These required accuracies are compared with the real accuracies available which are at the present time of order of 5-20% on these parameters

  6. Determination of fuel irradiation parameters. Required accuracies and available methods

    International Nuclear Information System (INIS)

    Mas, P.

    1977-01-01

    This paper reports on the present point of some main methods to determine the nuclear parameters of fuel irradiation in testing reactors (nuclear power, burn up, ...) The different methods (theoretical or experimental) are reviewed: neutron measurements and calculations, gamma scanning, heat balance, ... . The required accuracies are reviewed: they are of 3-5 % on flux, fluences, nuclear power, burn-up, conversion factor. These required accuracies are compared with the real accuracies available which are the present time of order of 5-20 % on these parameters

  7. UKF-based attitude determination method for gyroless satellite

    Institute of Scientific and Technical Information of China (English)

    张红梅; 邓正隆

    2004-01-01

    UKF (unscented Kalman filtering) is a new filtering method suitable to nonlinear systems. The method need not linearize nonlinear systems at the prediction stage of filtering, which is indispensable in EKF (extended Kalman filtering). As a result, the linearization error is avoided, and the filtering accuracy is greatly improved. UKF is applied to the attitude determination for gyroless satellite. Simulations are made to compare the new filter with the traditional EKF.The results indicate that under same conditions, compared with EKF, UKF has faster convergence speed, higher filtering accuracy and more stable estimation performance.

  8. Model-independent determination of dissociation energies: method and applications

    International Nuclear Information System (INIS)

    Vogel, Manuel; Hansen, Klavs; Herlert, Alexander; Schweikhard, Lutz

    2003-01-01

    A number of methods are available for the purpose of extracting dissociation energies of polyatomic particles. Many of these techniques relate the rate of disintegration at a known excitation energy to the value of the dissociation energy. However, such a determination is susceptible to systematic uncertainties, mainly due to the unknown thermal properties of the particles and the potential existence of 'dark' channels, such as radiative cooling. These problems can be avoided with a recently developed procedure, which applies energy-dependent reactions of the decay products as an uncalibrated thermometer. Thus, it allows a direct measurement of dissociation energies, without any assumption on properties of the system or on details of the disintegration process. The experiments have been performed in a Penning trap, where both rate constants and branching ratios have been measured. The dissociation energies determined with different versions of the method yield identical values, within a small uncertainty

  9. New method for determining avalanche breakdown voltage of silicon photomultipliers

    International Nuclear Information System (INIS)

    Chirikov-Zorin, I.

    2017-01-01

    The avalanche breakdown and Geiger mode of the silicon p-n junction is considered. A precise physically motivated method is proposed for determining the avalanche breakdown voltage of silicon photomultipliers (SiPM). The method is based on measuring the dependence of the relative photon detection efficiency (PDE rel ) on the bias voltage when one type of carriers (electron or hole) is injected into the avalanche multiplication zone of the p-n junction. The injection of electrons or holes from the base region of the SiPM semiconductor structure is performed using short-wave or long-wave light. At a low overvoltage (1-2 V) the detection efficiency is linearly dependent on the bias voltage; therefore, extrapolation to zero PDE rel value determines the SiPM avalanche breakdown voltage with an accuracy within a few millivolts. [ru

  10. Flow injection spectrofluorimetric method for the determination of cadmium

    International Nuclear Information System (INIS)

    Bo Tang; Taixing Yue; Lili Zhang; Junsen Wu; Zhenzhen Chen

    2004-01-01

    A novel fluorescent reagent, o-vanillin furoylhydrazone (OVFH), was synthesized, and its infrared spectrum, elemental analysis and dissociation constant are reported. The reaction between Cd 2+ and OVFH produces an intensely fluorescent complex in ethanol-water medium of pH 10.00, and this finding has led to a simple, rapid, and sensitive flow injection (FI) spectrofluorimetric method for on-line determination of Cd 2+ . Under the optimum experimental conditions, the fluorescent complex had excitation and emission maxima at 393 and 494 nm, respectively. The linear range is from 0.025 to 8.0 μg mL -1 of Cd 2+ , the detection limit is 7.6 μg L -1 and the maximum sampling rate is 80 h -1 . The effect of interferences was studied. The method was successfully applied to the determination of cadmium in environmental samples. (author)

  11. Radionuclide method for blood volume determination in kidneys

    International Nuclear Information System (INIS)

    Trindev, P.; Nikolov, D.; Shejretova, E.; Garcheva-Tsacheva, M.

    1989-01-01

    The method is applied in nephrology for diagnosing changes in blood circulation of the kidneys. The blood volume of each kidney is determined separately by perfusion angioscintigraphy (PAS) with improved accuracy. The method consists in intravenous injection of 300-450 MBq 99m Tc for in-vivo labelling of the erythrocytes. About 30 images are registered every 2 sec, and through zones of interest perfusion histograms of kidneys are derived. Ten minutes later kidneys images (one full-face and two profiles) are registered. Correction coefficients for kidneys depth are derived and the activities registered according to full-face images and amplitudes of perfusion histograms are corrected. The activity of 1 ml blood is determined from blood sample of the patient. The blood volume of each kidney is expressed as a ratio of the activity corrected for background and depth and the activity of 1 ml blood of the sample. 1 claim

  12. Nitrogen and carbon source balance determines longevity, independently of fermentative or respiratory metabolism in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Santos, Júlia; Leitão-Correia, Fernanda; Sousa, Maria João; Leão, Cecília

    2016-04-26

    Dietary regimens have proven to delay aging and age-associated diseases in several eukaryotic model organisms but the input of nutritional balance to longevity regulation is still poorly understood. Here, we present data on the role of single carbon and nitrogen sources and their interplay in yeast longevity. Data demonstrate that ammonium, a rich nitrogen source, decreases chronological life span (CLS) of the prototrophic Saccharomyces cerevisiae strain PYCC 4072 in a concentration-dependent manner and, accordingly, that CLS can be extended through ammonium restriction, even in conditions of initial glucose abundance. We further show that CLS extension depends on initial ammonium and glucose concentrations in the growth medium, as long as other nutrients are not limiting. Glutamine, another rich nitrogen source, induced CLS shortening similarly to ammonium, but this effect was not observed with the poor nitrogen source urea. Ammonium decreased yeast CLS independently of the metabolic process activated during aging, either respiration or fermentation, and induced replication stress inhibiting a proper cell cycle arrest in G0/G1 phase. The present results shade new light on the nutritional equilibrium as a key factor on cell longevity and may contribute for the definition of interventions to promote life span and healthy aging.

  13. Method for determining efficiency in a liquid scintillation system

    International Nuclear Information System (INIS)

    Laney, B.H.

    1975-01-01

    In a liquid scintillation system utilizing plural photomultiplyier means, a method for determining efficiency of coincident pulse detection. Various incremental counting efficiency levels are associated with asymptotic functions in a two dimension matrix in which the abscissa and ordinate correspond to the pulse heights of each of a pair of coincident pulses from different photomultiplier means. An efficiency determining point is located in the matrix based on the sum of the pulse heights of each of the coincident pulses as well as on the amplitude of the smallest pulse of the coincident pulses. The single counting efficiency determining point is recorded as the level of efficiency at which the photomultiplier means detect scintillations that generate coincident pulses having pulse heights equal to those recorded. (Patent Office Record)

  14. Determination of ion diffusion coefficients by the electromigration method

    International Nuclear Information System (INIS)

    Bonchev, G.D.; Milanov, M.V.; Bozhikov, G.A.; Ivanov, P.I.; Priemyshev, A.N.; Maslov, O.D.; Dmitriev, S.N.

    2003-01-01

    An electrophoretic method for measuring ion diffusion coefficients in aqueous solutions is developed. The value of the diffusion coefficient can be determined from the linear relationship between the square standard deviation of the electrophoretic zone and the time from the start of the diffusion process. Using the device for horizontal zone electrophoresis in a free electrolyte, a series of diffusion experiments are performed with no-carrier-added radionuclides in microconcentrations (10 -9 - 10 -10 M). Diffusion coefficients of 111 In(III), 175 Hf(IV) and 237 Pu(VI) ions at 25 0 C are determined in nitric acid media. Simultaneous determination of the diffusion coefficient and electrophoretic mobility allows one to calculate the effective charge of the investigated ions in accordance with the Nernst-Einstein law

  15. Kinematic method for beam energy determination at electrostatic generators

    International Nuclear Information System (INIS)

    Thomas, H.J.; Gersch, H.U.; Hentschel, E.; Wohlfahrt, D.

    1975-06-01

    The applicability of the kinematics of nuclear reactions to the energy determination of a particle beam is discussed. Most favourable conditions are obtained for the kinematic cross over of particles elastically and inelastically scattered at targets with different masses. At tandem energies between 4 and 15 MeV this method permits an exact determination with a precision of about 1 keV. The scattered particles must be measured at about 170 0 with a precision of the scattering angle of 0.1 0 . For the energy determination of a proton beam the compounds LiF, LiCl, or deuterium enriched hydrocarbons are found to be proper target materials. Experimental results with a LiF-target are described. (author)

  16. A projection method for under determined optimal experimental designs

    KAUST Repository

    Long, Quan; Scavino, Marco; Tempone, Raul; Wang, Suojin

    2014-01-01

    A new implementation, based on the Laplace approximation, was developed in (Long, Scavino, Tempone, & Wang 2013) to accelerate the estimation of the post–experimental expected information gains in the model parameters and predictive quantities of interest. A closed–form approximation of the inner integral and the order of the corresponding dominant error term were obtained in the cases where the parameters are determined by the experiment. In this work, we extend that method to the general cases where the model parameters could not be determined completely by the data from the proposed experiments. We carry out the Laplace approximations in the directions orthogonal to the null space of the corresponding Jacobian matrix, so that the information gain (Kullback–Leibler divergence) can be reduced to an integration against the marginal density of the transformed parameters which are not determined by the experiments. Furthermore, the expected information gain can be approximated by an integration over the prior, where the integrand is a function of the projected posterior covariance matrix. To deal with the issue of dimensionality in a complex problem, we use Monte Carlo sampling or sparse quadratures for the integration over the prior probability density function, depending on the regularity of the integrand function. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear under determined numerical examples.

  17. A projection method for under determined optimal experimental designs

    KAUST Repository

    Long, Quan

    2014-01-09

    A new implementation, based on the Laplace approximation, was developed in (Long, Scavino, Tempone, & Wang 2013) to accelerate the estimation of the post–experimental expected information gains in the model parameters and predictive quantities of interest. A closed–form approximation of the inner integral and the order of the corresponding dominant error term were obtained in the cases where the parameters are determined by the experiment. In this work, we extend that method to the general cases where the model parameters could not be determined completely by the data from the proposed experiments. We carry out the Laplace approximations in the directions orthogonal to the null space of the corresponding Jacobian matrix, so that the information gain (Kullback–Leibler divergence) can be reduced to an integration against the marginal density of the transformed parameters which are not determined by the experiments. Furthermore, the expected information gain can be approximated by an integration over the prior, where the integrand is a function of the projected posterior covariance matrix. To deal with the issue of dimensionality in a complex problem, we use Monte Carlo sampling or sparse quadratures for the integration over the prior probability density function, depending on the regularity of the integrand function. We demonstrate the accuracy, efficiency and robustness of the proposed method via several nonlinear under determined numerical examples.

  18. Spectrographical method for determining temperature variations of cosmic rays

    International Nuclear Information System (INIS)

    Dorman, L.I.; Krest'yannikov, Yu.Ya.; AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln)

    1977-01-01

    A spectrographic method for determining [sigmaJsup(μ)/Jsup(μ)]sub(T) temperature variations in cosmic rays is proposed. The value of (sigmaJsup(μ)/Jsup(μ)]sub(T) is determined from three equations for neutron supermonitors and the equation for the muon component of cosmic rays. It is assumed that all the observation data include corrections for the barometric effect. No temperature effect is observed in the neutron component. To improve the reliability and accuracy of the results obtained the surface area of the existing devices and the number of spectrographic equations should be increased as compared with that of the unknown values. The value of [sigmaJsup(μ)/Jsup(μ)]sub(T) for time instants when the aerological probing was carried out, was determined from the data of observations of cosmic rays with the aid of a spectrographic complex of devices of Sib IZMIR. The r.m.s. dispersion of the difference is about 0.2%, which agrees with the expected dispersion. The agreement obtained can be regarded as an independent proof of the correctness of the theory of meteorological effects of cosmic rays. With the existing detection accuracy the spectrographic method can be used for determining the hourly values of temperature corrections for the muon component

  19. Selective methods for polyphenols and sulphur dioxide determination in wines.

    Science.gov (United States)

    García-Guzmán, Juan J; Hernández-Artiga, María P; Palacios-Ponce de León, Lourdes; Bellido-Milla, Dolores

    2015-09-01

    A critical review to the methods recommended by international bodies and widely used in the winery industry and research studies was performed. A Laccase biosensor was applied to the selective determination of polyphenols in wines. The biosensor response was characterised and it responds mainly to o-diphenols which are the principal polyphenols responsible for the stability and sensory qualities of wines. The spectrophotometric method to determine free and total sulphur dioxide recommended for beers was applied directly to wines. A sampling of 14 red and white wines was performed and they were analysed for biosensor polyphenol index (IBP) and sulphur dioxide concentration (SO2). The antioxidant capacity by the ABTS(+) spectrophotometric method was also determined. A correlation study was performed to elucidate the influence of the polyphenols and SO2 on the wines stability. High correlations were found between IBP and antioxidant capacity and low correlation between SO2 and antioxidant capacity. To evaluate the benefits of wine drinking a new parameter (IBP/SO2) is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Methods for determination of zirconium in titanium alloys

    International Nuclear Information System (INIS)

    1985-01-01

    Two methods for determining zirconium content in titanium alloys are specified in this standard. One is the ion-exchange/mandelic acid gravimetry for Zr content below 20 % down to 1 % while the other is the mandelic acid gravimetry for Zr content below 20 % down to 0.5 %. In the former, a specimen is decomposed by hydrochloric acid and hydrofluoric acid. After substances such as titanium are oxidized by adding nitric acid, the liquid is adjusted into a 4N hydrochloric acid - gN hydrofluoric acid solution, which is them passed through an ion-exchange column. The niobium and tantalum contents are absorbed while the titanium and zirconium contents flow out. Perchloric acid and sulfuric acid are poured in the solution to remove hydrofluoric acid. Aqueous ammonia is added to produce hydroxide of titanium and zirconium, which is then filtered out. The hydroxyde is dissolved in hydrochloric acid, and mandelic acid is poured to precipitate the zirconium content. The precipitate is ignited and the weight of the oxide formed is measured. The coprecipitated titanium content is determined by the absorptiometric method using hydrogen peroxide. Finally, the weight of the oxide is corrected. In the latter determination method, on the other hand, only several steps of the above procedure are used, namely, decomposition by hydrochloric acid, precipitation of zirconium, ignition of precipitate, measurement of oxide weight and weight correction. (Nogami, K.)

  1. Classical Methods and Calculation Algorithms for Determining Lime Requirements

    Directory of Open Access Journals (Sweden)

    André Guarçoni

    Full Text Available ABSTRACT The methods developed for determination of lime requirements (LR are based on widely accepted principles. However, the formulas used for calculation have evolved little over recent decades, and in some cases there are indications of their inadequacy. The aim of this study was to compare the lime requirements calculated by three classic formulas and three algorithms, defining those most appropriate for supplying Ca and Mg to coffee plants and the smaller possibility of causing overliming. The database used contained 600 soil samples, which were collected in coffee plantings. The LR was estimated by the methods of base saturation, neutralization of Al3+, and elevation of Ca2+ and Mg2+ contents (two formulas and by the three calculation algorithms. Averages of the lime requirements were compared, determining the frequency distribution of the 600 lime requirements (LR estimated through each calculation method. In soils with low cation exchange capacity at pH 7, the base saturation method may fail to adequately supply the plants with Ca and Mg in many situations, while the method of Al3+ neutralization and elevation of Ca2+ and Mg2+ contents can result in the calculation of application rates that will increase the pH above the suitable range. Among the methods studied for calculating lime requirements, the algorithm that predicts reaching a defined base saturation, with adequate Ca and Mg supply and the maximum application rate limited to the H+Al value, proved to be the most efficient calculation method, and it can be recommended for use in numerous crops conditions.

  2. Dynamic pressure sensitivity determination with Mach number method

    Science.gov (United States)

    Sarraf, Christophe; Damion, Jean-Pierre

    2018-05-01

    Measurements of pressure in fast transient conditions are often performed even if the dynamic characteristic of the transducer are not traceable to international standards. Moreover, the question of a primary standard in dynamic pressure is still open, especially for gaseous applications. The question is to improve dynamic standards in order to respond to expressed industrial needs. In this paper, the method proposed in the EMRP IND09 ‘Dynamic’ project, which can be called the ‘ideal shock tube method’, is compared with the ‘collective standard method’ currently used in the Laboratoire de Métrologie Dynamique (LNE/ENSAM). The input is a step of pressure generated by a shock tube. The transducer is a piezoelectric pressure sensor. With the ‘ideal shock tube method’ the sensitivity of a pressure sensor is first determined dynamically. This method requires a shock tube implemented with piezoelectric shock wave detectors. The measurement of the Mach number in the tube allows an evaluation of the incident pressure amplitude of a step using a theoretical 1D model of the shock tube. Heat transfer, other actual effects and effects of the shock tube imperfections are not taken into account. The amplitude of the pressure step is then used to determine the sensitivity in dynamic conditions. The second method uses a frequency bandwidth comparison to determine pressure at frequencies from quasi-static conditions, traceable to static pressure standards, to higher frequencies (up to 10 kHz). The measurand is also a step of pressure generated by a supposed ideal shock tube or a fast-opening device. The results are provided as a transfer function with an uncertainty budget assigned to a frequency range, also deliverable frequency by frequency. The largest uncertainty in the bandwidth of comparison is used to trace the final pressure step level measured in dynamic conditions, owing that this pressure is not measurable in a steady state on a shock tube. A reference

  3. Effect of planting methods, seed density and nitrogen phosphorus (NP) fertilizer levels on sweet corn (Zea maYs L.)

    International Nuclear Information System (INIS)

    Amin, M.; Razzaq, A.; Ullah, R.

    2006-01-01

    A field experiment was conducted to evaluate the effect of planting methods, seed density and nitrogen phosphorus (NP) fertilizer levels on emergence m/sup -2/ growth and grain yield of sweet corn. The fertilizer and interaction of fertilizer x seed density had significant negative effect with increasing level while seed density had a positive effect with increased density on emergence per m/sup 2/. Increased seed density significantly reduced plant growth which increased with application of higher fertilizer dose. The grain yield was improves by ridge planting methods, increased seed density and increased fertilizer levels. The highest grain yield (3,553.50 kg ha/sup-1/) of sweet corn plants was recorded in ridge planting method with highest NP fertilizer level of 300:150 kg ha/sup 1/ and 4 seeds hill/sup -1/. The lowest grain yield (3,493.75 kg ha/sup -1/) of sweet corn was observed in flat sowing planting method with 120:75 NP level and 2 seeds hill/sup -1/ seed density. The ridge planting rank first then furrow and flat planting methods on basis of grain yield per hectare. The sweet corn plant yield was high with 4 seeds hill/sup -1/ compared with 2 seeds hill/sup -1/. (author)

  4. Pu and Am determination in the environment method development

    International Nuclear Information System (INIS)

    Afonin, M.; Simonoff, M.; Donard, O.; Michel, H.; Ardisson, G.

    2002-01-01

    A few articles were published in the recent years regarding the application of ICP MS HR to the determination of ultratrace Pu in the environment. Si removal was not applied in recent publications. It is well known from marine biology that some microorganisms use Si derivatives in their metabolism. This implies that important amounts of Pu will not be dissolved and instead will rest in the solid residue. In our work we chose a combination of methods from EML-300 Handbook: Pu-02-RC Plutonium in Soil Samples, Pu-03-RC Plutonium in Soil Residue - Total Dissolution Method, Pu-11-RC Plutonium Purification - Ion Exchange Technique, Pu-12-RC Plutonium and/or Americium in Soil or Sediments. A high resolution inductively coupled plasma mass spectrometric method was developed for the determination of Am and the 240 Pu/ 239 Pu isotope ratio. The total plutonium concentrations ( 239+240 Pu) measured in environmental samples by this method were in good agreement with recommended data obtained from alpha-spectrometry. A reduction in the time of analysis over 33% was achieved

  5. A marine eutrophication impacts assessment method in LCIA coupling coastal ecosystems exposure to nitrogen and species sensitivity to hypoxia

    DEFF Research Database (Denmark)

    Cosme, Nuno Miguel Dias; Koski, Marja; Hauschild, Michael Zwicky

    Characterisation modelling in Life Cycle Impact Assessment (LCIA) aims at quantifying potential impacts of anthropogenic emissions. It delivers substance-specific Characterisation Factors (CF) expressing ecosystem responses to marginal increments in emitted quantities. Nitrogen (N) emissions from e.......g. agriculture and industry enrich coastal marine ecosystems. Excessive algal growth and dissolved oxygen (DO) depletion typify the resulting marine eutrophication. LCIA modelling frameworks typically encompass fate, exposure and effect in the environment. The present novel method couples relevant marine...... biological processes of ecosystem’s N exposure (Exposure Factor, XF) with the sensitivity of select species to hypoxia (Effect Factor, EF). The XF converts N-inputs into a sinking carbon flux from planktonic primary production and DO consumed by bacterial respiration in bottom waters, whereas EF builds...

  6. Characterization of carbon, nitrogen, oxygen and refractory metals in binary and ternary silicon-based films using ion beam methods

    International Nuclear Information System (INIS)

    Somatri-Bouamrane, R.

    1996-01-01

    Ion beam methods (non Rutherford backscattering, nuclear reactions) have been carried out in order to characterize silicon-based films. The cross sections for the reactions 12 C(α,α), 14 N(α,α), 16 O(α,α), 28 Si(α,α) and 14 N(α,p) have been measured within 2 and 7 MeV. CVD beta SiC films could be analyzed and the interface between silicon carbide and the (100) silicon substrate was studied. The epitaxial growth of the beta SiC film could be modelled by comparing the results obtained with ion beam analysis, infrared spectroscopy and electron microscopy. Moreover, the stoichiometry of low pressure CVD Me-Si-N (Me=Re, W, Ti, Ta) ternary systems was studied. The evolution of the nitrogen content in W-Si-N systems allowed to study their stability with respect to the annealing conditions. (N.T.)

  7. Platinum incorporation in the Na Y zeolite through impregnation method, and characterization by XRD, FTIR and nitrogen adsorption

    International Nuclear Information System (INIS)

    Araujo, A.S.; Sousa, B.V.; Andrade, A.C.C.; Rodrigues, M.G.F.; Rangel, M.C.

    2007-01-01

    Supported metal catalysts are widely used in petroleum refining, chemical and petroleum industries. These catalysts are important in ammonia synthesis, conversion of hydrocarbons with water vapor to synthesis gas, reforming, hydrocracking, ... Platinum has long been used in cracking, hydrogenation and dehydrogenation processes. The aim of this project is the Na Y zeolitic sample preparation through impregnation for incipient humidity, with 0,5% concentration of platinum, aiming its use as a catalyst in the steam reforming reaction. The characterization techniques used were: X Rays Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and Nitrogen Adsorption (BET Method). From the obtained results through the techniques mentioned previously it is possible to evidence that the platinum impregnation process did not change the Na Y zeolite structure. Through the superficial specific area (BET) it was possible to observe that the platinum impregnation process caused a decrease in the specific area due to the reduction to the accessibility to the micropores of the zeolitic structure. (author)

  8. Nitrogen-doped carbon quantum dots from biomass via simple one-pot method and exploration of their application

    Science.gov (United States)

    Yang, Qiming; Duan, Jialong; Yang, Wen; Li, Xueming; Mo, Jinghui; Yang, Peizhi; Tang, Qunwei

    2018-03-01

    Pursuit of low-cost and large-scale method to prepare carbon quantum dots (CQDs) is a persistent objective in recent years. In this work, we have successfully synthesized a series of nitrogen-doped carbon quantum dots (N-CQDs) under different hydrothermal temperature employing Eichhornia crassipes (ECs) as precursors. Considering the pollution ability to water and low-cost, this study may direct the novel path to convert waste material to useful quantum dots. After measurements such as TEM, XRD, Raman, XPS, PL as well as the UV-vis absorbance ability, outstanding optical properties have been discovered. In this fashion, solar cells are tentative to be fabricated, yielding the maximized solar-to-electrical conversion efficiency of 0.17% with a good fill factor of 67%. Meanwhile, the above-mentioned quantum dots also show the up-conversion ability, suggesting the potential application in infrared detection or broadening light-absorbing devices.

  9. Preparation of three-dimensional nitrogen-doped graphene layers by gas foaming method and its electrochemical capactive behavior

    International Nuclear Information System (INIS)

    Hao, Junnan; Shu, Dong; Guo, Songtao; Gao, Aimei; He, Chun; Zhong, Yayun; Liao, Yuqing; Huang, Yulan; Zhong, Jie

    2016-01-01

    Highlights: • A three-dimensional porous graphene layers was prepared via a gas foaming method. • Melamine was the nitrogen source to synthesize the N-doped 3D graphene layers. • The specific surface area of 3D N-doped graphene material is as high as 1196 m 2 g −1 . • The 3D N-doped graphene specific capacitance is 335 F g −1 in three-electrode system. • The energy density of 3D N-doped graphene reaches 58.1 Wh kg −1 in a symmetric cell. - Abstract: A porous graphene layers with a three-dimensional structure (3DG) was prepared via a gas foaming method based on a polymeric predecessor. This intimately interconnected 3DG structure not only significantly increases the specific surface area but also provides more channels to facilitate electron transport. In addition, 3D N-doped (3DNG) layers materials were synthesized using melamine as a nitrogen source. The nitrogen content in the 3DNG layers significantly influenced the electrochemical performance. The sample denoted as 3DNG-2 exhibited a specific capacitance of 335.2 F g −1 at a current density of 1 A g −1 in a three-electrode system. Additionally, 3DNG-2 exhibited excellent electrochemical performance in aqueous and organic electrolytes using a two-electrode symmetric cell. An energy density of 58.1 Wh kg −1 at a power density of 2500 W kg −1 was achieved, which is approximately 3 times that (19.6 Wh kg −1 ) in an aqueous electrolyte in a two-electrode system. After 1000 cycles, the capacity retention in aqueous electrolyte was more than 99.0%, and this retention in organic electrolytes was more than 89.4%, which demonstrated its excellent cycle stability. This performance makes 3DNG-2 a promising candidate as an electrode material in high-power and high-energy supercapacitor applications.

  10. METHOD FOR DETERMINATION OF FOCAL PLANE LOCATION OF FOCUSING COMPONENTS

    Directory of Open Access Journals (Sweden)

    A. I. Ivashko

    2017-01-01

    Full Text Available Mass-production of different laser systems often requires utilization of the focal spot size method for determination of output laser beam spatial characteristics. The main challenge of this method is high accuracy maintenance of a CCD camera beam profiler in the collecting lens focal plane. The aim of our work is development of new method for placing of photodetector array in the collecting lens focal plane with high accuracy.Proposed technique is based on focusing of several parallel laser beams. Determination of the focal plane position requires only longitudinal translation of the CCD-camera to find a point of laser beams intersection. Continuous-wave (CW diode-pumped laser emitting in the spectral region near 1μm was created to satisfy the requirements of the developed technique. Designed microchip laser generates two stigmatic Gaussian beams with automatically parallel beam axes due to independent pumping of different areas of the one microchip crystal having the same cavity mirrors.It was theoretically demonstrated that developed method provides possibility of the lenses focal plane determination with 1 % accuracy. The microchip laser generates two parallel Gaussian beams with divergence of about 10 mrad. Laser output power can be varied in the range of 0.1–1.5 W by changing the pumping laser diode electrical current. The distance between two beam axes can be changed in the range of 0.5–5.0 mm.We have proposed method for determination of positive lens focal plane location by using of CCDcamera and two laser beams with parallel axes without utilization of additional optical devices. We have developed CW longitudinally diode pumped microchip laser emitting in the 1-μm spectral region that can be used in the measuring instrument that doesn’t require precision mechanical components for determination of focal plane location with 1 % accuracy. The overall dimensions of laser head was 70 × 40 × 40 mm3 and maximum power consumption was

  11. [A method for the determination of ergot alkaloids in food].

    Science.gov (United States)

    Klug, C; Baltes, W; Krönert, W; Weber, R

    1988-02-01

    A suitable method has been developed for the routine analysis of the ergot alkaloids ergometrine, ergometrinine, ergosine, ergosinine, ergotamine, ergotaminine, ergocornine, ergocorninine, alpha-ergocryptine, alpha-ergocryptinine, beta-ergocryptine, beta-ergocryptinine, ergocristine and ergocristinine in cereal products. The method consists of food extraction, cleaning of the crude extract by a modified form of the Extrelut method, and identification and quantitative determination of the alkaloids by high pressure liquid chromatography (HPLC). The results are confirmed by thin layer chromatography (TLC) and gas-chromatography/mass spectrometry (GC/MS). Market investigations have shown contaminations in ecological as well as in conventional products, with rye products mainly being contaminated. Within the EEC, a maximum value of 0.05% ergot respectively a total alkaloid content of 1 mg/kg in cereals used for food production is prescribed. This value was not exceeded in any of the investigated samples.

  12. Gravimetric method for the determination of diclofenac in pharmaceutical preparations.

    Science.gov (United States)

    Tubino, Matthieu; De Souza, Rafael L

    2005-01-01

    A gravimetric method for the determination of diclofenac in pharmaceutical preparations was developed. Diclofenac is precipitated from aqueous solution with copper(II) acetate in pH 5.3 (acetic acid/acetate buffer). Sample aliquots had approximately the same quantity of the drug content in tablets (50 mg) or in ampules (75 mg). The observed standard deviation was about +/- 2 mg; therefore, the relative standard deviation (RSD) was approximately 4% for tablet and 3% for ampule preparations. The results were compared with those obtained with the liquid chromatography method recommended in the United States Pharmacopoeia using the statistical Student's t-test. Complete agreement was observed. It is possible to obtain more precise results using higher aliquots, for example 200 mg, in which case the RSD falls to 1%. This gravimetric method, contrary to what is expected for this kind of procedure, is relatively fast and simple to perform. The main advantage is the absolute character of the gravimetric analysis.

  13. The simple method of determination peaks areas in multiplets

    International Nuclear Information System (INIS)

    Loska, L.; Ptasinski, J.

    1991-01-01

    Semiconductor germanium detectors used in γ-spectrometry give spectra with well-separated peaks. However, in some cases, energies of γ-lines are too near, to produce resolved and undisturbed peaks. Then, there is a necessity to perform a mathematical separation. The method proposed here is based on the assumption, that areas of peaks composing the analysed multiplet are proportional to their heights. The method can be applied for any number of interfering peaks, providing, that the function of the background under the multiplet is accurately determined. The results of testing calculations performed on a simulated spectrum are given. The method works successfully in a computer program used for neutron activation analysis data processing. (author). 9 refs, 1 fig, 1 tab

  14. Applying Nyquist's method for stability determination to solar wind observations

    Science.gov (United States)

    Klein, Kristopher G.; Kasper, Justin C.; Korreck, K. E.; Stevens, Michael L.

    2017-10-01

    The role instabilities play in governing the evolution of solar and astrophysical plasmas is a matter of considerable scientific interest. The large number of sources of free energy accessible to such nearly collisionless plasmas makes general modeling of unstable behavior, accounting for the temperatures, densities, anisotropies, and relative drifts of a large number of populations, analytically difficult. We therefore seek a general method of stability determination that may be automated for future analysis of solar wind observations. This work describes an efficient application of the Nyquist instability method to the Vlasov dispersion relation appropriate for hot, collisionless, magnetized plasmas, including the solar wind. The algorithm recovers the familiar proton temperature anisotropy instabilities, as well as instabilities that had been previously identified using fits extracted from in situ observations in Gary et al. (2016). Future proposed applications of this method are discussed.

  15. Rapid Enzymatic Method for Pectin Methyl Esters Determination

    Directory of Open Access Journals (Sweden)

    Lucyna Łękawska-Andrinopoulou

    2013-01-01

    Full Text Available Pectin is a natural polysaccharide used in food and pharma industries. Pectin degree of methylation is an important parameter having significant influence on pectin applications. A rapid, fully automated, kinetic flow method for determination of pectin methyl esters has been developed. The method is based on a lab-made analyzer using the reverse flow-injection/stopped flow principle. Methanol is released from pectin by pectin methylesterase in the first mixing coil. Enzyme working solution is injected further downstream and it is mixed with pectin/pectin methylesterase stream in the second mixing coil. Methanol is oxidized by alcohol oxidase releasing formaldehyde and hydrogen peroxide. This reaction is coupled to horse radish peroxidase catalyzed reaction, which gives the colored product 4-N-(p-benzoquinoneimine-antipyrine. Reaction rate is proportional to methanol concentration and it is followed using Ocean Optics USB 2000+ spectrophotometer. The analyzer is fully regulated by a lab written LabVIEW program. The detection limit was 1.47 mM with an analysis rate of 7 samples h−1. A paired t-test with results from manual method showed that the automated method results are equivalent to the manual method at the 95% confidence interval. The developed method is rapid and sustainable and it is the first application of flow analysis in pectin analysis.

  16. Simultaneous determination of a binary mixture: kinetic method for determination of uranium and vanadium

    International Nuclear Information System (INIS)

    Jianhua, W.; Ronghuan, H.

    1993-01-01

    A kinetic method for simultaneous determination of a binary mixture is proposed, and a procedure for simultaneous determination of uranium (IV) and vanadium (IV) is established based on their inductive effect on chromium (VI)-iodide redox reaction in a weak acidic medium. The reaction was monitored by FIA-spectrophotometry using the I 3 - -starch complex as indicator. The calibration graphs are linear for uranium (IV) and vanadium (IV) within the range of 0 ∼ 3.6 μg/ml and 0 ∼ 2.5 μg/ml respectively. Most foreign ions, except for iron (II) and antimony (III), do not interfere with the determination. The uranium and vanadium content in different samples was determined, and the results were satisfactory. (author). 2 tabs., 2 figs., 9 refs

  17. [Comparative data regarding two HPLC methods for determination of isoniazid].

    Science.gov (United States)

    Gârbuleţ, Daniela; Spac, A F; Dorneanu, V

    2009-01-01

    For the determination of isoniazide (isonicotinic acid hydrazide - HIN) two different HPLC methods were developed and validated. Both experiments were performed using a Waters 2695 liquid chromatograph and a UV - Waters 2489 detector. The first method (I) used a Nucleosil 100-10 C18 column (250 x 4.6 mm), a mobile phase formed by a mixture of acetonitrile/10(-2) M oxalic acid (80/20) and a flow of 1.5 mL/ min; detection was done at 230 nm. The second method (II) used a Luna 100-5 C18 column (250 x 4.6 mm), a mobile phase formed by a mixture of methanol/acetate buffer, pH = 5.0 (20/ 80), a flow of 1 mL/min; detection was done at 270 nm. Both methods were validated, the correlation coefficients were 0.9998 (I) and 0.9999 (II), the detection limits were 0.6 microg/mL (I) and 0.055 microg/mL (II), the quantitation limits were 1.9 microg/mL (I) and 0.2 microg/ mL (II). There were also studied: the system precision (RSD = 0.1692% (I) and 0.2000% (II)), the method precision (RSD = 1.1844% (I) and 0.6170% (II)) and the intermediate precision (RSD = 1.8058% (I) and 0.5970% (II)). The accuracy was good, the calculated recoveries were 102.66% (I) and 101.36 (II). Both validated methods were applied for HIN determination from tablets with good and comparable results.

  18. METHOD FOR DETERMINATION OF ROTATION CENTER IN VIBRATING OBJECT

    Directory of Open Access Journals (Sweden)

    I. P. Kauryha

    2016-01-01

    Full Text Available Linear piezoelectric gauges, eddy current transducers and other control and measuring devices have been widely applied for vibration diagnostics of objects in industry. Methods based on such gauges and used for measuring angular and linear vibrations do not provide the possibility to assess a rotation center or point angle of an object. Parasitic oscillations may occur during rotor rotation and in some cases the oscillations are caused by dis-balance. The known methods for measuring angular and linear vibrations make it possible to detect the phenomenon and they do not provide information for balancing of the given object. For this very reason the paper describes a method for obtaining instantaneous rotation center in the vibrating object. It allows to improve informational content of the measurements owing to obtaining additional data on position of object rotation center. The obtained data can be used for balancing of a control object. Essence of the given method is shown by an example of piezoelectric gauges of linear vibrations. Two three-axial gauges are fixed to the investigated object. Then gauge output signals are recalculated in angular vibrations of the object (for this purpose it is necessary to know a distance between gauges. Further projection positions of the object rotation center are determined on three orthogonal planes. Instantaneous rotation center is calculated according to the position of one of the gauges. The proposed method permits to obtain data on linear and angular vibrations and rotation center position of the vibrating object using one system of linear gauge. Possibilities of object diagnostics are expanded due to increase in number of determined parameters pertaining to object moving. The method also makes it possible to reduce material and time expenses for measurement of an angular vibration component. 

  19. Methods for determining radionuclide retardation factors: status report

    International Nuclear Information System (INIS)

    Relyea, J.F.; Serne, R.J.; Rai, D.

    1980-04-01

    This report identifies a number of mechanisms that retard radionuclide migration, and describes the static and dynamic methods that are used to study such retardation phenomena. Both static and dynamic methods are needed for reliable safety assessments of underground nuclear-waste repositories. This report also evaluates the extent to which the two methods may be used to diagnose radionuclide migration through various types of geologic media, among them unconsolidated, crushed, intact, and fractured rocks. Adsorption is one mechanism that can control radionuclide concentrations in solution and therefore impede radionuclide migration. Other mechanisms that control a solution's radionuclide concentration and radionuclide migration are precipitation of hydroxides and oxides, oxidation-reduction reactions, and the formation of minerals that might include the radionuclide as a structural element. The retardation mechanisms mentioned above are controlled by such factors as surface area, cation exchange capacity, solution pH, chemical composition of the rock and of the solution, oxidation-reduction potential, and radionuclide concentration. Rocks and ground waters used in determining retardation factors should represent the expected equilibrium conditions in the geologic system under investigation. Static test methods can be used to rapidly screen the effects of the factors mentioned above. Dynamic (or column) testing, is needed to assess the effects of hydrodynamics and the interaction of hydrodynamics with the other important parameters. This paper proposes both a standard method for conducting batch Kd determinations, and a standard format for organizing and reporting data. Dynamic testing methods are not presently developed to the point that a standard methodology can be proposed. Normal procedures are outlined for column experimentation and the data that are needed to analyze a column experiment are identified

  20. Evaluation of early nodulation and Nitrogen fixation a number of Bradyrhizobium Japonicum strains to increase nitrogen fixation ability of soybean cultivars ars by using the A-value (N-15) method

    International Nuclear Information System (INIS)

    Piervali-Bieranvand, N.; Teimori, S.; Khorasani, A.

    2004-01-01

    To date significant contribution of atmospheric N fixation to soybean nutrition and growth, is approved. Nevertheless several studies have demonstrated that effectiveness of soybean -rhizobium symbiosis is medium compared with other legumes. The time course study of biological nitrogen fixation in soybean under field conditions has been shown that soybean has limited initial fixation and fixes substantially atmospheric nitrogen just during the reproductive periods (R1 until R 5).So there is the possibility of enhancing nitrogen fixation in soybean during vegetation growth. This could be done by improving inoculation methods or breeding for early nodulation. Hence, the present study was conducted to examine the effect of some Bradyrhizobium japonicum strains on early nodulation and biological nitrogen fixation three soybean cultivars by using a-value method. The experiment, was a factorial on randomized complete block design with three replications under proper glass house condition. Treatments were harvesting times(one , two and three weeks after flowering, respectively.)soybean cultivars(Chippewa, M 112 and clay )and Bradyrhizobium japonicum strains(J 1, J 3 and J 43). Ninety-plastic pots were filled with 1.5 kg of a compound of sand and soil(1:3). Rhizobial inoculation was performed by mixing 10 ml of a suspension(Yeast extract Manitol Broth) containing about 9X10 8 cells per ml to the soil of mixing pots were kept weed-free and watered with demineralized water as well as have received every two weeks 5 ml of a solution containing all the necessary nutrients except nitrogen. For measuring biological nitrogen fixation using a-value approach, two solutions of N-15 enriched ammonium sulfate containing 10.16 and %2 N-15 atom excess in amount of 5 and 25 mg N/Kg soil were mixed with soils in each pot containing fixing and reference plants, respectively. A non-nodulation isoline of soybean C v. M 129 for the all cultivars was used as a reference crop. First harvest was

  1. Alternative method for determining anaerobic threshold in rowers

    Directory of Open Access Journals (Sweden)

    Giovani Dos Santos Cunha

    2008-01-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n4p367 In rowing, the standard breathing that athletes are trained to use makes it difficult, or even impossible, to detect ventilatory limits, due to the coupling of the breath with the technical movement. For this reason, some authors have proposed determining the anaerobic threshold from the respiratory exchange ratio (RER, but there is not yet consensus on what value of RER should be used. The objective of this study was to test what value of RER corresponds to the anaerobic threshold and whether this value can be used as an independent parameter for determining the anaerobic threshold of rowers. The sample comprised 23 male rowers. They were submitted to a maximal cardiorespiratory test on a rowing ergometer with concurrent ergospirometry in order to determine VO2máx and the physiological variables corresponding to their anaerobic threshold. The anaerobic threshold was determined using the Dmax (maximal distance method. The physiological variables were classified into maximum values and anaerobic threshold values. The maximal state of these rowers reached VO2 (58.2±4.4 ml.kg-1.min-1, lactate (8.2±2.1 mmol.L-1, power (384±54.3 W and RER (1.26±0.1. At the anaerobic threshold they reached VO2 (46.9±7.5 ml.kg-1.min-1, lactate (4.6±1.3 mmol.L-1, power (300± 37.8 W and RER (0.99±0.1. Conclusions - the RER can be used as an independent method for determining the anaerobic threshold of rowers, adopting a value of 0.99, however, RER should exhibit a non-linear increase above this figure.

  2. Determining concentrations of 2-bromoallyl alcohol and dibromopropene in ground water using quantitative methods

    Science.gov (United States)

    Panshin, Sandra Y.

    1997-01-01

    A method for determining levels of 2-bromoallyl alcohol and 2,3-dibromopropene from ground-water samples using liquid/liquid extraction followed by gas chromatography/mass spectrometry is described. Analytes were extracted from the water using three aliquots of dichloromethane. The aliquots were combined and reduced in volume by rotary evaporation followed by evaporation using a nitrogen stream. The extracts were analyzed by capillary-column gas chromatography/mass spectrometry in the full-scan mode. Estimated method detection limits were 30 nanograms per liter for 2-bromoallyl alcohol and 10 nanograms per liter for 2,3-dibromopropene. Recoveries were determined by spiking three matrices at two concentration levels (0.540 and 5.40 micrograms per liter for 2-bromoallyl alcohol; and 0.534 and 5.34micro-grams per liter for dibromopropene). For seven replicates of each matrix at the high concentration level, the mean percent recoveries ranged from 43.9 to 64.9 percent for 2-bromoallyl alcohol, and from 87.5 to 99.3 percent for dibromopropene. At the low concentration level, the mean percent recoveries ranged from 43.8 to 95.2 percent for 2-bromoallyl alcohol, and from 71.3 to 84.9 percent for dibromopropene.

  3. [Determination method of polysorbates in powdered soup by HPLC].

    Science.gov (United States)

    Takeda, Y; Abe, Y; Ishiwata, H; Yamada, T

    2001-04-01

    A method for qualitative and quantitative analyses of polysorbates in powdered soup by HPLC was studied. Polysorbates in samples were extracted with acetonitrile after rinsing with n-hexane to remove fats and oils. The extract was cleaned up using a Bond Elut silica gel cartridge (500 mg). The cartridge was washed with ethyl acetate and polysorbates were eluted with a small amount of acetonitrile-methanol (1:2) mixture. The eluate was treated with cobalt thiocyanate solution to form a blue complex with polysorbate. In order to determine polysorbate, the complex was subjected to HPLC with a GPC column, using a mixture of acetonitrile-water (95:5) as a mobile phase, with a detection wavelength of 620 nm. The recoveries of polysorbate 80 added to powdered soups were more than 75% and the determination limit was 0.04 mg/g. When the proposed method was applied to the determination of polysorbates in 16 commercial samples of powdered soup for instant noodles and seasoning consomme, no polysorbates were detected in any sample.

  4. New validated method for piracetam HPLC determination in human plasma.

    Science.gov (United States)

    Curticapean, Augustin; Imre, Silvia

    2007-01-10

    The new method for HPLC determination of piracetam in human plasma was developed and validated by a new approach. The simple determination by UV detection was performed on supernatant, obtained from plasma, after proteins precipitation with perchloric acid. The chromatographic separation of piracetam under a gradient elution was achieved at room temperature with a RP-18 LiChroSpher 100 column and aqueous mobile phase containing acetonitrile and methanol. The quantitative determination of piracetam was performed at 200 nm with a lower limit of quantification LLQ=2 microg/ml. For this limit, the calculated values of the coefficient of variation and difference between mean and the nominal concentration are CV%=9.7 and bias%=0.9 for the intra-day assay, and CV%=19.1 and bias%=-7.45 for the between-days assay. For precision, the range was CV%=1.8/11.6 in the intra-day and between-days assay, and for accuracy, the range was bias%=2.3/14.9 in the intra-day and between-days assay. In addition, the stability of piracetam in different conditions was verified. Piracetam proved to be stable in plasma during 4 weeks at -20 degrees C and for 36 h at 20 degrees C in the supernatant after protein precipitation. The new proposed method was used for a bioequivalence study of two medicines containing 800 mg piracetam.

  5. Improved method for the determination of dissolved radium-226

    International Nuclear Information System (INIS)

    Yang, I.C.

    1984-01-01

    Most of the current techniques for radium determination involve chemical separation of radium from major sample constituents by coprecipitation with barium or lead sulfate, followed by further radium purification. However, when samples contain biological materials, such as algae in wastewater from uranium millponds, or brine water from oil fields, the precipitation and purification processes become tedious and time-consuming. An improved method has been developed for the determination of radium-226 in such water samples, which also is applicable to natural waters. This method is based on a radon determination of alpha activity of the radon and its short-lived daughters in an alpha-scintillation cell. The radon-bubbler volume is either 90 millimeters for concentrated samples or 800 milliliters for dilute samples. For radium concentrations less than 1 picocurie per liter, 2 liters of water sample can be concentrated several-fold by simple evaporation, and decreased to 800 milliliters prior to deemanation. Because the process involves no chemical separations, chemical recoveries are nearly 100 percent. The lower limit of detection is 0.05 picocurie per liter for a 1-liter water sample and a counting time of 1000 minutes. 19 references, 3 figures, 3 tables

  6. VERIFICATION HPLC METHOD OF QUANTITATIVE DETERMINATION OF AMLODIPINE IN TABLETS

    Directory of Open Access Journals (Sweden)

    Khanin V. A

    2014-10-01

    Full Text Available Introduction. Amlodipine ((±-2-[(2-aminoetoksimethyl]-4-(2-chlorophenyl-1,4-dihydro-6-methyl-3,5-pyridine dicarboxylic acid 3-ethyl 5-methyl ester as besylate and small tally belongs to the group of selective long-acting calcium channel blockers, dihydropyridine derivatives. In clinical practice, as antianginal and antihypertensive agent for the treatment of cardiovascular diseases. It is produced in powder form, substance and finished dosage forms (tablets of 2.5, 5 and 10 mg. The scientific literature describes methods of quantitative determination of the drug by spectrophotometry – by his own light absorption and by reaction product with aloksan, chromatography techniques, kinetic-spectrophotometric method in substances and preparations and methods chromatomass spectrometry and stripping voltammetry. For the quantitative determination of amlodipine besylate British Pharmacopoeia and European Pharmacopoeia recommend the use of liquid chromatography method. In connection with the establishment of the second edition of SPhU and when it is comprised of articles on the finished product, we set out to analyze the characteristics of the validation of chromatographic quantitative determination of amlodipine besylate tablets and to verify the analytical procedure. Material & methods. In conducting research using substance amlodipine besylate series number AB0401013. Analysis subject pill “Amlodipine” series number 20113 manufacturer of “Pharmaceutical company “Zdorovye”. Analytical equipment used is: 2695 chromatograph with diode array detector 2996 firms Waters Corp. USA using column Nova-Pak C18 300 x 3,9 mm with a particle size of 4 μm, weight ER-182 company AND Japan, measuring vessel class A. Preparation of the test solution. To accurately sample powder tablets equivalent to 50 mg amlodipine, add 30 ml of methanol, shake for 30 minutes, dilute the solution to 50.0 ml with methanol and filtered. 5 ml of methanol solution adjusted to

  7. Determination of the carbon, hydrogen and nitrogen contents of alanine and their uncertainties using the certified reference material L-alanine (NMIJ CRM 6011-a).

    Science.gov (United States)

    Itoh, Nobuyasu; Sato, Ayako; Yamazaki, Taichi; Numata, Masahiko; Takatsu, Akiko

    2013-01-01

    The carbon, hydrogen, and nitrogen (CHN) contents of alanine and their uncertainties were estimated using a CHN analyzer and the certified reference material (CRM) L-alanine. The CHN contents and their uncertainties, as measured using the single-point calibration method, were 40.36 ± 0.20% for C, 7.86 ± 0.13% for H, and 15.66 ± 0.09% for N; the results obtained using the bracket calibration method were also comparable. The method described in this study is reasonable, convenient, and meets the general requirement of having uncertainties ≤ 0.4%.

  8. A new method of determining the ejected mass of novae

    Energy Technology Data Exchange (ETDEWEB)

    Sparks, W.M.

    1994-12-31

    A new method of determining the ejected mass of novae based on simple, reasonable assumptions is presented. This method assumes that the remnant mass on the white dwarf is the same as that from the previous nova outburst. The hydrogen, helium, and metal abundances of the accreted material from the secondary must also be known or assumed. The white dwarf`s mass has a small effect because the amount of hydrogen consumed during the thermonuclear runaway only depends weakly upon this mass. If the composition of the ejecta and the time of the remnant shell burnout are determined from observations, then the ejected and remnant masses can be deduced. At present only a sharp decrease in the X-rays observed by ROSAT has been attributed to this remnant burnout and only for two novae: GQ Mus and V1974 Cyg. The ejected and remnant masses for these two novae are calculated. If other indicators of nova remnant burnout, such as a rapid decrease in high-ionization lines, can be identified, then this method could be applied to additional novae.

  9. CD2 probe infrared method for determining polymethylene chain conformation

    International Nuclear Information System (INIS)

    Maroncelli, M.; Strauss, H.L.; Snyder, R.G.

    1985-01-01

    The rocking mode frequency of a CD 2 group substituted in a polymethylene chain is sensitive to conformation in the immediate vicinity of the CD 2 group. This sensitivity forms the basis of a commonly used infrared method for determining site-specific conformation in polymethylene systems. In the present work, the CD 2 probe method has been extended and quantified with the use of infrared data on model CD 2 -substituted n-alkanes. The frequency of the CD 2 rocking band is determined primarily by the conformation of adjoining CC bonds, i.e., by tt, gt, and gg pairs. However, we have found that there are significant frequency shifts associated with other factors. These include the conformation of the next nearest CC bonds, both with the CD 2 positioned at the end and in the interior of the chain, and chain length. In addition, the ratio of the absorptivities of the tt to gt bands has been established. These results enable the method to provide new details about the conformation of the chains in polymethylene systems and reliable estimates of the concentrations of specific kinds of short conformational sequences. 14 references, 6 figures, 2 tables

  10. Biochemistry of the normal dura mater of the human brain determination of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur and nitrogen contents

    Directory of Open Access Journals (Sweden)

    Horacio M. Canelas

    1969-06-01

    Full Text Available The concentrations of water, sodium, potassium, calcium, phosphorus, magnesium, copper, iron, sulfur, and nitrogen were determined in samples of apparently normal dura mater removed from 18 subjects recently dead by craniocerebral trauma. The average concentrations expressed in dry weight were: water 79.55 g/100 g ± 2.52; sodium 1.63 mequiv/100 g ±0.27; potassium 3.68 mequiv/100 g ± 0.66; calcium 119.84 mg/100 g ± 107.40; phosphorus 68.2 mg/100 g ± 34.5; magnesium 0.61 mequiv/100 g ± 0.37; copper 249.8 /xg/100 g ± 109.4; iron 0.82 mg/100 g ± 0.28; sulfur 490.7 mg/100 g ± 22.5; nitrogen 3.33 g/100 g ± 0.17.

  11. Nitrate biosensors and biological methods for nitrate determination.

    Science.gov (United States)

    Sohail, Manzar; Adeloju, Samuel B

    2016-06-01

    The inorganic nitrate (NO3‾) anion is present under a variety of both natural and artificial environmental conditions. Nitrate is ubiquitous within the environment, food, industrial and physiological systems and is mostly present as hydrated anion of a corresponding dissolved salt. Due to the significant environmental and toxicological effects of nitrate, its determination and monitoring in environmental and industrial waters are often necessary. A wide range of analytical techniques are available for nitrate determination in various sample matrices. This review discusses biosensors available for nitrate determination using the enzyme nitrate reductase (NaR). We conclude that nitrate determination using biosensors is an excellent non-toxic alternative to all other available analytical methods. Over the last fifteen years biosensing technology for nitrate analysis has progressed very well, however, there is a need to expedite the development of nitrate biosensors as a suitable alternative to non-enzymatic techniques through the use of different polymers, nanostructures, mediators and strategies to overcome oxygen interference. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. A chemiluminescent method for determination of lipid peroxidation

    International Nuclear Information System (INIS)

    Liang Xiaofeng; Hu Tianxi; Fan Xiaobing

    2003-01-01

    We established a chemiluminescent system for determination of lipid peroxidation and screening anti-oxidants. The lipid containing unsaturated fatly acids was injected into a galls tube. Luminol solution and the deionized water were added into it too. The glass tube was put into a preincubation box to incubate it for 0.5 h at 37 degree C. AAPH solution was injected into the tube for immediate measurement in a biochemiluminometer at 38-39 degree C. The pulses /6s(CP6s) were determined with T-2 program. Chemiluminescent dynamic and lipid peroxidation changes were observed continuously. Once the CL intensity of lipid peroxidation got peak, the antioxidant which has different concentration was added immediately in situ. A certain CL intensity (CP6s) was chosen as evaluation index to compare the activity of antioxidants. A luminol chemiluminescent system for determination of lipid peroxidation has been made. It was found that Vit. C, teapolyphenol, and glutathione have effects on scavenging lipid free radicals. The new method is quick, sensitive, and simple for determination of lipid peroxidation and screening antioxidants

  13. Kinetic method for determination of iodide ion ultramicroamounts

    International Nuclear Information System (INIS)

    Barkauskas, Yu.K.; Ramanauskas, Eh.I.

    1980-01-01

    A kinetic method for iodides ultramicroamount determination from their catalytic effect on oxidation of malachite green with chloramine B in the presence of acetone at pH 5.78+-0.3 is developed. The induction period of the reaction is determined from a change in the redox potential of the system. The induction period is proportional to the iodides concentration. Determination limit of iodides is equal to 4 μg iodide per 100 l of solution. More than 10 5 -multiple amounts of K + , Na + , NH 4+ , Ba 2 + , Al 3 + , Cu 2 + , Mg 2 + , SO 4 2 - , Cl - , MoO 4 2 - , NO 3- , ClO 3- , IO 3- , IO 4- , ClO 4- , BrO 3- ; 10 5 -10 3 -multiple amounts of Cr 3 + , Fe 3 + , Sn 2 + , S 2 - , MnO 4- , NO 2- etc. do not interfere with the determination, while 10-multiple amounts of SCN, 0.2-multiple quantities of Ag + , Hg 2 2 + do

  14. Determination of occluded oxygen, nitrogen and hydrogen in zircalloy-4 by vacuum extraction coupled to gas chromatography

    International Nuclear Information System (INIS)

    Vega, O.; Imakuma, K.

    1983-01-01

    The technique of vacuum extraction at high temperatures was used for the liberation of gases from zircalloy-4 samples; oxygen, nitrogen and hydrogen were quantitatively analysed by gas chromatography. Two different sets of zircalloy-4 samples were examined. The results for O 2 , N 2 and H 2 quantitative analyses satisfy the requirements for the characterization of the zircalloy-4 quality. (C.L.B.) [pt

  15. METHODS FOR DETERMINING THE AESTHETIC APPEAL OF FURNITURE

    Directory of Open Access Journals (Sweden)

    Mária Réka ANTAL

    2016-03-01

    Full Text Available The world of furniture market is getting more and more complex than it was before. In recent years the habits of buying furniture have changed. The fabrication of individual pieces of furniture is increasingly coming to the front. A personal contact is being established between the customer and the furniture, which is a relationship of one product to one customer. In order to satisfy the individual demands, higher prices and higher quality are needed. The competition is beginning at the market and emotion plays an important role in it. Therefore, functionality and aesthetic functions, determinative forms, fashionable style play a very important role in furniture design and production. Some methods are presented such as RMQD or FMEA used for determining aesthetics of furniture.

  16. A method for the determination of technetium in environmental waters

    International Nuclear Information System (INIS)

    Robb, P.; Warwick, P.; Malcolme-Lawes, D.J.

    1985-01-01

    A method is described which can be used to determine technetium-99 levels in a range of water types. Ruthenium isotopes which may interfere in the analysis are removed from the sample by precipitation before concentration of pertechnetate onto an ion-exchange column. Other nuclides can be removed from the column using NaOH before elution of the technetium using NaSCN. The technetium in the NaSNC eluent can then be extracted into butan-2-one which can be evaporated onto a planchette. Technetium-99m is used as a yield tracer and after this has decayed away to negligible levels. The amount of technetium on the planchette can be determined by measuring the rate of beta radiation emission from the final concentrate. (author)

  17. Method and apparatus for determining the dose value of neutrons

    International Nuclear Information System (INIS)

    Burgkhardt, B.; Piesch, E.

    1976-01-01

    A method is provided for determining the dose value of neutrons leaving a body as thermal and intermediate neutrons after having been scattered in the body. A first dose value of thermal and intermediate neutrons is detected on the surface of the body by means of a first detector for neutrons which is shielded against thermal and intermediate neutrons not emerging from the body. A second detector is used to measure a second dose value of the thermal and intermediate neutrons not emerging from the body. A first correction factor based on the first and second values is obtained from a calibration diagram and is applied to the first dose value to determine a first corrected first dose value. 21 Claims, 6 Drawing Figures

  18. Determination of brazed joint constitutive law by inverse method

    International Nuclear Information System (INIS)

    Lovato, G.; Moret, F.; Gallo, P. le; Cailletaud, G.; Pilvin, P.

    1993-01-01

    An important parameter often neglected for the calculation of residual stresses in brazed ceramic/metal assemblies is the joint constitutive law. In situ camber measurements on a model system (axisymmetric TZM/InCuSil ABA/316L samples) performed using a special vertical dilatometer during the whole brazing thermal cycle are compared with results of FEM calculations based on published filler metal constitutive laws. A strong disagreement is observed. Actual constitutive law of the joint is determined from these measurements using a numerical inverse method. Calculated displacements are fully consistent with experimental ones. True solidification temperature of the joint is determined. The identified constitutive law of the joint exhibits a low flow stress from solidification temperature to 320 C. (orig.)

  19. Analysis of Methods of Determining the Safe Ship Trajectory

    Directory of Open Access Journals (Sweden)

    Jozef Lisowski

    2016-07-01

    Full Text Available The paper describes six methods of optimal and game theory and artificial neural network for synthesis of safe control in collision situations at sea. The application of optimal and game control algorithms to determine the own ship safe trajectory during the passing of other encountered ships in good and restricted visibility at sea is presented. The comparison of the safe ship control in collision situation: multi-step matrix non-cooperative and cooperative games, multi-stage positional non-cooperative and cooperative games have been introduced. The considerations have been illustrated with examples of computer simulation of the algorithms to determine safe of own ship trajectories in a navigational situation during passing of eight met ships.

  20. Cycle length and COD/N ratio determine properties of aerobic granules treating high-nitrogen wastewater.

    Science.gov (United States)

    Cydzik-Kwiatkowska, Agnieszka; Bernat, Katarzyna; Zielińska, Magdalena; Wojnowska-Baryła, Irena

    2014-07-01

    Aerobic granule characteristic in sequencing batch reactors treating high-nitrogen digester supernatant was investigated at cycle lengths (t) of 6, 8 and 12 h with the COD/N ratios in the influent of 4.5 and 2.3. The biomass production (Y obs) correlated with the extracellular polymeric substances (EPS) in grams per COD removed. Denitrification efficiency significantly decreased as the amount of EPS in biomass increased, suggesting that organic assimilation in EPS hampers nitrogen removal. Granule hydrophobicity was highest at t of 8 h; the t has to be long enough to remove pollutants, but not so long that excessive biomass starvation causes extracellular protein consumption that decreases hydrophobicity. At a given t, reducing the COD/N ratio improved hydrophobicity that stimulates cell aggregation. At t of 6 h and the COD/N ratio of 2.3, the dominance of 0.5-1.0 mm granules favored simultaneous nitrification and denitrification and resulted in the highest nitrogen removal.