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Sample records for plasma urea nitrogen

  1. Plasma urea nitrogen and progesterone concentrations and follicular dynamics in ewes fed proteins of different degradability

    Directory of Open Access Journals (Sweden)

    Gustavo Bianchi Lazarin

    2012-07-01

    Full Text Available The effects of overfeeding with protein of different degradability on body condition, plasma urea nitrogen and progesterone concentrations, ovulation number and follicular dynamics were assessed in Santa Ines ewes. Twelve ewes were assigned to a randomized block design according to body weight and received overfeeding with soybean meal or with corn gluten meal or maintenance diet for 28 days before ovulation and during the next estrous cycle. Blood samples were taken on days 7, 14, 21, and 28 after the beginning of treatments for analysis of plasma urea nitrogen and on days 3, 6, 9, 12, and 15 into the estrous cycle for analysis of plasma urea nitrogen and progesterone. Follicular dynamics was monitored daily by ultrasound during one estrous cycle. Dry matter and crude protein intake, weight gain, plasma urea nitrogen concentration before ovulation, number of ovulations, diameter of the largest follicle of the 1st and of the 2nd waves and the growth rate of the largest follicle of the 1st wave were higher in the ewes that received overfeeding. The growth rate of the largest follicle of the 3rd wave was higher in the ewes fed maintenance diet. The back fat thickness, plasma urea nitrogen before ovulation and progesterone concentrations, diameter of the largest follicle of the 2nd wave and growth rate of the largest follicle of the 3rd wave were higher in ewes that received overfeeding with soybean meal. The growth rate of the largest follicle of the 1st wave was higher in ewes that received overfeeding with corn gluten meal. Overfeeding with protein-rich feeds may increase the ovulation number and with soybean meal, it may be effective in increasing plasma progesterone concentration in ewes.

  2. Uterine environment and pregnancy rate of heifers with elevated plasma urea nitrogen.

    Science.gov (United States)

    Amundson, Olivia L; Larimore, Erin L; McNeel, Anthony K; Chase, Chad C; Cushman, Robert A; Freetly, Harvey C; Perry, George A

    2016-10-01

    Diets high in protein are associated with lower reproductive performance and changes in the uterine environment. The objective of this study was to determine the effect of elevated systemic concentrations of urea nitrogen on the uterine environment and pregnancy success in beef heifers. Heifers (n=150) were matched by breed, age, and body weight then randomly assigned to one of two dietary treatments: 1) Control (10% CP) or 2) High protein (14% CP) over three replicates (n=40/replicate). Estrus was synchronized with an injection of PGF2α. Uterine pH, plasma urea nitrogen (PUN), ammonia, and glucose concentrations were determined on d 7 of the estrous cycle. Pregnancy status was determined by ultrasonography 30 d following the breeding season. In vitro fertilization was performed on heifers precluded from uterine analysis (n=15/diet) to determine the effect of a High Protein diet on oocyte quality. Plasma urea concentrations were greater in the High Protein diet compared to Control (P0.40) on the number of oocytes collected, number of oocytes cleaved, amount of blastocysts, percentage of oocytes cleaved and percentage of blastocysts present. In summary, high nitrogen diets increased PUN concentrations in heifers; however, there were no deleterious effects on reproduction.

  3. Uterine environment and pregnancy rate of heifers with elevated plasma urea nitrogen

    Science.gov (United States)

    Diets high in protein are associated with lower reproductive performance and changes in the uterine environment. The objective of this study was to determine the effect of elevated systemic concentrations of urea nitrogen on the uterine environment and pregnancy success in beef heifers. Heifers (n...

  4. Performance and plasma urea nitrogen of immunocastrated males pigs of medium genetic potential

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    Fabiana R Caldara

    2015-05-01

    Full Text Available ABSTRACT Objective. A study was carried out to evaluate the performance and the plasma urea nitrogen (PUN of male pigs of medium genetic potential for lean meat deposition in carcass, which underwent immunocastration. Materials and methods. Forty-five seventy-days old Large White x Landrace crossbred were used. The pigs were distributed in a randomized design in three treatments: castrated males, females and immunocastrated males. Each treatment group was replicated three times with five pigs per replicate. The trial period was of 70 days, divided into phases of growing (70 to 110 days old and finishing (111 to 140 days old. The pigs were weighed four times: at the beginning of the trial, at the first immunocastration vaccine dose (80 days old, at the second immunocastration vaccine dose (110 days old and just before slaughter (140 days old. Blood samples were taken on the same day that the animals were weighed. Results. Between 80 and 110 days old, there was an increase in PUN value, only for castrated males and females. No differences were found in weight gain between the studied groups within the periods. Immunocastrated males had lower feed intake than females and these had a lower feed intake than castrated males. To 110 days old, immunocastrated animals showed feed conversion ratio similar to females and better than castrated males. However, after the second dose of the vaccine, feed conversion was similar between groups. Conclusions. The benefits of immunocastration are prominent in animals with low to medium genetic potential.

  5. Technical note: Effect of determining baseline plasma urea nitrogen concentrations on subsequent posttreatment plasma urea nitrogen concentrations in 20- to 50-kilogram pigs.

    Science.gov (United States)

    Waguespack, A M; Powell, S; Roux, M L; Frugé, E D; Bidner, T D; Payne, R L; Southern, L L

    2011-12-01

    Plasma urea N (PUN) has been used as an indicator of AA requirements and efficiency of AA utilization in swine. However, PUN concentrations vary among a population of pigs, even a population with a close range of BW and fed the same diet. Thus, pretreatment or baseline PUN concentrations are used as a covariate to reduce variation of posttreatment PUN. However, this procedure increases experimental costs and stress to the pigs. Data from 14 experiments (26 to 28 d in duration) conducted using PUN as a response variable were compiled into 1 data set. Each experiment had 4 to 6 treatments. The purpose of this technical report was to summarize the effect of determining pretreatment baseline PUN concentrations on subsequent posttreatment PUN concentrations in 20- to 50-kg pigs. In all experiments, pigs were fed corn- and soybean meal-based diets and low-CP diets with various AA additions; pigs were assigned to dietary treatments in a randomized complete block design with a minimum of 4 replicates of 3 to 5 pigs each. Before the start of each experiment, all pigs were fed a common diet for a minimum of 3 d. Blood samples were collected from each pig before allotment to dietary treatments (d 0) and at the end of each experiment. The baseline (d 0) PUN was analyzed as a covariate for posttreatment PUN. Data from each experiment were analyzed without and with baseline PUN in the statistical model. In all experiments combined, there were 768 possible treatment comparisons. The covariate baseline PUN was statistically significant (P < 0.10) in 9 of 14 experiments. However, only 8 treatment differences changed statistical significance as a result of analyzing the data with baseline PUN as a covariate. These 8 treatment differences were in 3 experiments. These results indicate that it is not always necessary to determine baseline PUN concentrations when feeding diets with large differences in AA content.

  6. 21 CFR 862.1770 - Urea nitrogen test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urea nitrogen test system. 862.1770 Section 862.1770 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and...

  7. The rate and pattern of urea infusion into the rumen of wethers alters nitrogen balance and plasma ammonia.

    Science.gov (United States)

    Recavarren, M I; Milano, G D

    2014-12-01

    Changes in N balance, urinary excretion of purine derivative (PD), urea, creatinine and ammonia and plasma ammonia, glucose, urea, insulin and IGF-1 were examined in four wethers (37 ± 2.6 kg BW). The animals were fitted with permanent ruminal catheters, fed lucerne hay (9.4 MJ/day; 23 g N/day; 7 g soluble N/day, 6 equal meals/day) and treated with contrasting rates of urea infusion into the rumen: first, a continuous infusion (CT), at 3.2 mg urea-N/min for 10 days and then a discontinuous infusion (DT) at 156 mg urea-N/min for 4 min; in 6 daily doses with the meals for 7 days. N balance was calculated from pooled samples of faeces and urine. Jugular blood samples were collected before and 1.5 h after the morning meal (M1) on days CT10, DT2, DT4 and DT6. N retention decreased during DT (p = 0.01) due to a significant increase of N excretion in urine (4 g/day; p = 0.009) and faeces (1 g/day; p = 0.02). Dry matter (p < 0.001) and N digestibility in vivo (p = 0.01) decreased significantly during DT. Urinary urea and PD excretion were not altered by treatment. Significant linear (p = 0.004) and quadratic (p = 0.001) effects were observed for plasma ammonia in M1 (from 170 CT10 to 235 μm DT2 and returned to 120 μm DT6). No changes were observed in plasma glucose, urea, insulin and IGF-1. Results indicate that changes from CT to DT reduced N retention in sheep due to enhanced urinary N excretion, but it was not associated with changes in urinary urea or PD excretion; or plasma concentrations of insulin and IGF-1. As the dry matter (DM) an N digestibility could account a 0.23 of the decrease in N retention; the largest fraction of the reduction in N retention remained unexplained by the results.

  8. The post: pre dialysis plasma urea nitrogen ratio to estimate K.t/V and NPCR: validation.

    Science.gov (United States)

    Daugirdas, J T

    1989-07-01

    The ability of empirical formulae to predict K.t/V based on the ratio (R) of the postdialysis (Ct) to predialysis (Co) plasma urea nitrogen levels was tested. In 256 patients, 336 three-point modeling sessions were performed. The K.t/V and NPCR were derived by interative solution of equations for V and G according to the variable volume single-pool model. The modeled K.t/V values were compared to K.t/V predicted from the formula: K.t/V = -ln (R - 0.008.t-UF/W), where R is the Ct/Co ratio, t the session length (h), UF the ultrafiltrate volume (liters) and W the postdialysis weight (kg). Further, the ratio-derived K.t/V was used in conjunction with the Gotch nomogram for 3/week dialysis to estimate NPCR (NPCR-R/N); the latter value was compared to the NPCR from standard 3-point modeling (NPCR-MOD). The two K.t/V values were quite similar, although statistically separable: modeled K.t/V, 0.97 +/- 0.22 (SD), ratio-derived K.t/V 0.96 +/- 0.23, p less than 0.001. The mean percent error was -0.73% +/- 2.5 (range - 11 to + 4.8), and the correlation coefficient was 0.994, slope 1.01, int -0.016. Modifications of the prediction formula which incorporated UF/V instead of UF/W, and/or which weighted the UF/V term according to the expected K.t/V, produced only slight improvement in accuracy. The two values of NPCR were less similar, but still highly correlated: NPCR-MOD, 1.04 +/- 0.26 g/kg/day, NPCR-R/N, 0.94 +/- 0.23, p less than 0.001; mean percent error, - 8.2 +/- 16; r = 0.78, slope = 0.68, int = 0.23.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Effect of CLA supplementation to low-protein diets on the growth performance, carcass characteristics, plasma urea nitrogen concentration, and fatty acid profile in the meat of pigs

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    Manuel Martínez-Aispuro

    2014-10-01

    Full Text Available To analyze the effect of conjugated linoleic acid (CLA on the meat of pigs (0,1% and three crude protein (CP levels (nursery: 20.5, 16.0, 14.5%; growing: 16, 14.5, 11.5%; and finishing: 14.0, 12.5, 11% CP, studies were conducted with 36 hybrid (Yorkshire×Landrace×Duroc barrows (17.3-83.5 kg, which were individually penned and allotted in a completely randomized design in a factorial (2×3 arrangement for 84 d. The analysis by phases indicated that CP level affected some variables. Average daily gain, average daily feed intake, fat free lean gain, backfat thickness, longissimus muscle area and final body weight were reduced (P≤0.05 feeding the lowest CP diet in nursery and growing pigs. Plasma urea nitrogen concentration was also lower (P≤0.05 in the growing and finishing phases when fed the lowest CP level. The global analysis showed that all the analyzed variables (except feed gain ratio, lean meat percentage and plasma urea nitrogen concentration were reduced (P≤0.05 in the pigs fed low-protein diets; plasma urea nitrogen concentration tended to be lower (P=0.07 when CP was reduced. The fatty acid profile of the meat (semimembranosus and longissimus muscles indicated that CLA addition increased CLA isomers and total saturated fatty acids, and reduced the total monounsaturated fatty acids (P≤0.05. α-Linolenic acid was lowered in longissimus muscle of pigs fed LPD (P=0.08. These results indicated that reducing the crude protein concentration in the diet of fattening pigs from 20.5 to 16.0% in nursery phase; from 16.0 to 14.5% in growing stage; and from 14.0 to 12.5% in finishing pigs, did not negatively affect the growth performance, nor carcass characteristics. The results also showed that the addition of CLA did not improve pig response and the concentration of unsaturated fatty acids and total lipids altered the feeding LPD.

  10. Time-response relationship of ractopamine feeding on growth performance, plasma urea nitrogen concentration, and carcass traits of finishing pigs.

    Science.gov (United States)

    Almeida, V V; Nuñez, A J C; Schinckel, A P; Andrade, C; Balieiro, J C C; Sbardella, M; Miyada, V S

    2013-02-01

    Ractopamine hydrochloride (RAC) improves swine production efficiency by redirecting nutrients to favor muscle accretion rather than fat deposition. In the present study, the time-dependent effect of RAC feeding on performance, plasma urea N (PUN) concentrations, and carcass traits of finishing pigs were evaluated. In a 28-d growth study, 80 barrows (average initial BW = 69.4 ± 7.9 kg) were assigned to 1 of 5 treatments in a randomized complete block design with 8 replicate pens per treatment and 2 pigs per pen. The pigs were fed a corn-soybean meal-based diet with no added RAC (control) or 10 mg of RAC/kg fed for 7, 14, 21, or 28 d before slaughter. All diets were formulated to contain 0.88% standardized ileal digestible Lys (1.0% total Lys) and 3.23 Mcal of ME/kg. Individual pig BW and pen feed disappearance were recorded weekly to determine BW changes, ADG, ADFI, and G:F. Anterior vena cava blood samples were taken on d 28 for determination of PUN concentrations. After 28 d on trial, the pigs were slaughtered and carcass measurements made at 24 h postmortem. Overall, providing pigs with different RAC feeding durations did not affect the final BW and ADFI but resulted in a tendency (P = 0.09) for a linear increase in ADG and a linear improvement (P = 0.003) in G:F. No effect of RAC feeding was found for weekly ADFI. Weekly improvements (P < 0.05) in ADG and G:F were observed over the first 21 d of RAC feeding. However, the growth response declined (P < 0.05) in wk 4 of RAC treatment. The concentrations of PUN exhibited a quadratic decrease (P = 0.004) as the RAC feeding duration increased. Although RAC feeding did not affect any backfat measurements and carcass length, increasing the RAC feeding duration linearly increased HCW (P = 0.01), dressing percentage (P = 0.03), LM depth (P = 0.001), LM area (P < 0.001), muscle-to-fat ratio (P = 0.004), and predicted carcass lean percentage (P = 0.02). These results indicate that a greater growth rate was achieved within

  11. Influence of milk urea concentration on fractional urea disappearance rate from milk to blood plasma in dairy cows

    NARCIS (Netherlands)

    Spek, J.W.; Dijkstra, J.; Bannink, A.

    2016-01-01

    The relationship between milk urea nitrogen (MUN; mg of N/dL) and urinary N excretion is affected, among others, by diurnal dynamics in MUN, which in turn is largely influenced by feed intake pattern and characteristics of urea transfer from blood plasma to milk and vice versa. This study aimed t

  12. Influence of milk urea concentration on fractional urea disappearance rate from milk to blood plasma in dairy cows

    NARCIS (Netherlands)

    Spek, J.W.; Dijkstra, J.; Bannink, A.

    2016-01-01

    The relationship between milk urea nitrogen (MUN; mg of N/dL) and urinary N excretion is affected, among others, by diurnal dynamics in MUN, which in turn is largely influenced by feed intake pattern and characteristics of urea transfer from blood plasma to milk and vice versa. This study aimed

  13. Influence of milk urea concentration on fractional urea disappearance rate from milk to blood plasma in dairy cows.

    Science.gov (United States)

    Spek, J W; Dijkstra, J; Bannink, A

    2016-05-01

    The relationship between milk urea nitrogen (MUN; mg of N/dL) and urinary N excretion is affected, among others, by diurnal dynamics in MUN, which in turn is largely influenced by feed intake pattern and characteristics of urea transfer from blood plasma to milk and vice versa. This study aimed to obtain insight in urea transfer characteristics within the mammary gland and from the mammary gland to blood plasma in dairy cows at various concentrations of plasma urea nitrogen (PUN; mg of N/dL) and MUN. Urea transfer from milk to blood plasma and urea transfer within the mammary gland itself was evaluated in a 4×4 Latin square design using 4 lactating multiparous Holstein-Friesian cows (milk production of 39.8±4.70kg/d and 90±3.9 d in milk). Treatments consisted of 4 primed continuous intravenous urea infusions of 0, 5, 10, and 15g of urea/h. Boluses of [(15)N(15)N]urea were injected in cistern milk at 20, 60, and 100 min before the 1700h milking. Milk was collected in portions of approximately 2 L at the 1700h milking. Milk samples were analyzed for urea and enrichment of (15)N-urea. Results from one cow were discarded because of leakage of milk from the teats after injection of boluses of [(15)N(15)N]urea. Increasing urea infusion rate linearly increased PUN from 11.4 (0g of urea/h) to 25.9mg/dL (15g of urea/h) and MUN from 10.3 (0g of urea/h) to 23.5 (15g of urea/h) mg of N/dL. The percentage of injected [(15)N(15)N]urea recovered from milk at the time of injection was not affected by urea infusion rate and varied between 65.1 and 73.0%, indicating that a substantial portion of injected [(15)N(15)N]urea was not accounted for by collected milk. The estimated fractional disappearance rate of (15)N-urea from milk to blood (Kurea; per hour) linearly increased from 0.429 (0g of urea/h) to 0.641 per hour (15g of urea/h). Cistern injected [(15)N(15)N]urea diffused within 20 min after injection toward alveoli milk. Calculations with the average Kurea estimated in this

  14. (Flavomycin ) on milk production and milk urea nitrogen ...

    African Journals Online (AJOL)

    Unknown

    Flavomycin addition only reduced the milk urea nitrogen (MUN) ... chemistry, primary antibacterial spectrum, mode of action of bacterial inhibition, ... March) and limited irrigated annual ryegrass (Lolium multiflorum) grazing plus maize silage in ...

  15. Preparation of Urea Nitrogen Adsorbent of Complex Type and Adsorption Capacity of Urea Nitrogen onto the Adsorbent

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The urea nitroge n adsorbent of complex type, which consists of chitosan coated dialdehyde cellulose (CDAC) and immobilized urease in gelatin membrane (IE), was prepared. The cellulose, the dialdehyde cellulose (DAC) and the CDAC were characterized by scanning electronic microscope. The results indicate that the cellulose C2-C3 bond was broken under the oxidation of periodate and it was oxidated to DAC. The DAC was coated with chitosan and the CDAC was obtained. The adsorption of urea nitrogen onto the adsorbent in Na2HPO4-NaH2PO4 buffer solution was studied in batch system. The effects of the experiment parameters, including degree of oxidation of CDAC, initial urea nitrogen concentration, pH and temperature, on the adsorption capacity of urea nitrogen onto the adsorbent at CDAC/IE weight ratio 10:1 were investigated. The results indicate that these parameters affected significantly the adsorption capacity. The adsorption capacity of urea nitrogen onto the adsorbent was 36.7 mg/g at the degree of oxidation of CDAC 88%, initial urea nitrogen concentration 600 mg/L, pH 7.4 and temperature 37 ℃.

  16. Effects of dietary threonine:lysine ratioes and sanitary conditions on performance, plasma urea nitrogen, plasma-free threonine and lysine of weaned pigs

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    Balachandar Jayaraman

    2015-12-01

    Full Text Available Two 21 d-experiments were conducted to determine the optimum standardized ileal digestible (SID threonine:lysine ratio (Thr:Lys for weaned piglets reared under clean (Exp. 1 or unclean (Exp. 2 sanitary conditions and fed antibiotic-free diets. In each experiment, 90 mixed-sex pigs (Duroc × [Yorkshire × Landrace]; initial BW 7.2 ± 0.3 kg were randomly assigned to 5 dietary treatments each with 6 replicates (3 pigs per pen. The dietary treatments were 5 graded levels of SID Thr:Lys (55, 59, 63, 67 and 71%. Diets were corn-wheat-soybean meal-based with a constant SID Lys of 1.18% that was set to be second limiting amino acid. In Exp. 1 and Exp. 2, plasma-free Thr increased (P = 0.05 with increasing dietary SID Thr:Lys. In Exp. 1, the SID Thr:Lys for gain-to-feed ratio (G:F was optimized at 65%. In Exp. 2, the estimated optimal SID Thr:Lys for overall G:F was 66.5%. In conclusion, an average optimal SID Thr:Lys of 65 and 66.5% could be used to optimize feed efficiency for weaned pigs under clean and unclean sanitary conditions, respectively.

  17. Effects of Controlled-Release Urea on Grain Yield of Spring Maize, Nitrogen Use Efficiency and Nitrogen Balance

    OpenAIRE

    JI Jing-hong; Li, Yu-Ying; Liu, Shuang-Quan; TONG Yu-xin; REN Gui-lin; Li, Jie; Liu,Ying; ZHANG Ming-yi

    2017-01-01

    The effects of mixing controlled-released urea (CRU) (release period of resin coated urea is 90 days) and urea (U) on maize yield, nitrogen use efficiency and nitrogen balance were studied by 4 plot experiments (site:Shuangcheng, Binxian, Harbin and Zhaoyuan) in two years (from year 2011 to 2012) to clarify the effect of controlled release urea on spring maize and soil nitrogen balance. Results were as follow:Spring maize yield and nitrogen absorption were increased with the increasing nitrog...

  18. Effects of Controlled-Release Urea on Grain Yield of Spring Maize, Nitrogen Use Efficiency and Nitrogen Balance

    OpenAIRE

    JI Jing-hong; Li, Yu-Ying; LIU Shuang-quan; TONG Yu-xin; REN Gui-lin; Li,Jie; Liu, Ying; Zhang, Ming-Yi

    2017-01-01

    The effects of mixing controlled-released urea (CRU) (release period of resin coated urea is 90 days) and urea (U) on maize yield, nitrogen use efficiency and nitrogen balance were studied by 4 plot experiments (site:Shuangcheng, Binxian, Harbin and Zhaoyuan) in two years (from year 2011 to 2012) to clarify the effect of controlled release urea on spring maize and soil nitrogen balance. Results were as follow:Spring maize yield and nitrogen absorption were increased with the increasing nitrog...

  19. Effects of plasma total ammonia content and pH on urea excretion in Nile tilapia.

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    McKenzie, D J; Piraccini, G; Felskie, A; Romano, P; Bronzi, P; Bolis, C L

    1999-01-01

    Nile tilapia (Oreochromis niloticus) were infused with ammonium salts, acid, and base to investigate the effects of changes in arterial plasma total ammonia content (Tamm) and pH (pHa) on plasma urea-nitrogen (urea-N) levels and urea-N excretory fluxes (Jurea-N). The tilapia did not possess a functional hepatic ornithine urea-cycle (no significant carbamyl phosphate synthetase III activity). Infused substances were dissolved in a saline vehicle and injected twice (5 mL kg-1), the first infusion to "prime" the animal and promote a more marked response to the second infusion, given 2.5 h later. The results reported are those of the second infusion. Infusion of 200 mM NH4Cl increased Tamm, reduced pHa, and increased plasma urea-N and Jurea-N. Two hundred mM NH4HCO3 increased Tamm and arterial plasma total CO2 content (TaCO2), reduced pHa, and increased Jurea-N. Fifty mM HCl reduced pHa but had no effects on urea dynamics. Fifty mM NaOH increased pHa, plasma urea-N levels, and Jurea-N. Two hundred mM NaHCO3 increased pHa, TaCO2, plasma urea-N levels, and Jurea-N. Infusion of the saline vehicle was without effect. The results indicate that ammonia loading and plasma alkalosis both stimulate urea excretion in uricolytic fish. The responses to hyperammonemia or alkalosis were not modified when combined with elevated plasma bicarbonate levels.

  20. Effects of Controlled-Release Urea on Grain Yield of Spring Maize, Nitrogen Use Efficiency and Nitrogen Balance

    Directory of Open Access Journals (Sweden)

    JI Jing-hong

    2017-03-01

    Full Text Available The effects of mixing controlled-released urea (CRU (release period of resin coated urea is 90 days and urea (U on maize yield, nitrogen use efficiency and nitrogen balance were studied by 4 plot experiments (site:Shuangcheng, Binxian, Harbin and Zhaoyuan in two years (from year 2011 to 2012 to clarify the effect of controlled release urea on spring maize and soil nitrogen balance. Results were as follow:Spring maize yield and nitrogen absorption were increased with the increasing nitrogen fertilizer. Compared with applying urea treatment, applying CRU could increase yield, nitrogen absorption, nitrogen use efficiency, agriculture efficiency of nitrogen and nitrogen contribution rate. Under the same amount of nitrogen (100%, 75%, 50%, compared with 100% U as basic fertilizer treatment, maize yield of 100% CRU treatment increased 391, 427, 291 kg·hm-2, nitrogen use efficiency increased by 5.9%,4.9% and 5.1%, agriculture efficiency of nitrogen increased 2.0, 2.6, 2.6 kg·kg-1, and nitrogen contribution rate increased 2.7%, 3.1% and 2.4%, respectively. The value of maize yield, nitrogen absorption, nitrogen use efficiency and agriculture efficiency of nitrogen between the treatment four (40% urea as basic fertilizer+60% urea as topdressing and treatment five (40% urea plus 60% controlled release urea as basic fertilizer were similar. Apparent profit and loss of nitrogen decreased with the increase of nitrogen nitrogen fertilizer. Nitrogen apparent loss by applying 100% controlled release urea was reduced of 15.0 kg·hm-2 than applying 100% U treatment;Nitrogen apparent loss amount was decreased of 23.9 kg·hm-2 under treatment five. The method of mixing 40% urea and 60% controlled release urea should be applied in maize production in Heilongjiang Province.

  1. Altered nitrogen balance and decreased urea excretion in male rats fed cafeteria diet are related to arginine availability.

    Science.gov (United States)

    Sabater, David; Agnelli, Silvia; Arriarán, Sofía; Fernández-López, José-Antonio; Romero, María del Mar; Alemany, Marià; Remesar, Xavier

    2014-01-01

    Hyperlipidic diets limit glucose oxidation and favor amino acid preservation, hampering the elimination of excess dietary nitrogen and the catabolic utilization of amino acids. We analyzed whether reduced urea excretion was a consequence of higher NO x ; (nitrite, nitrate, and other derivatives) availability caused by increased nitric oxide production in metabolic syndrome. Rats fed a cafeteria diet for 30 days had a higher intake and accumulation of amino acid nitrogen and lower urea excretion. There were no differences in plasma nitrate or nitrite. NO(x) and creatinine excretion accounted for only a small part of total nitrogen excretion. Rats fed a cafeteria diet had higher plasma levels of glutamine, serine, threonine, glycine, and ornithine when compared with controls, whereas arginine was lower. Liver carbamoyl-phosphate synthetase I activity was higher in cafeteria diet-fed rats, but arginase I was lower. The high carbamoyl-phosphate synthetase activity and ornithine levels suggest activation of the urea cycle in cafeteria diet-fed rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

  2. Nitrogen Cycling and Losses Under Rice-Wheat Rotations with Coated Urea and Urea in the Taihu Lake Region

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-Zhi; ZHU Jian-Guo; GAO Ren; H. YASUKAZU; FENG Ke

    2007-01-01

    A lysimeter experiment with undisturbed soil profiles was carried out to study nitrogen cycling and losses in a paddy soil with applications of coated urea and urea under a rice-wheat rotation system in the Taihu Lake region from 2001 to 2003. Treatments for rice and wheat included urea at conventional, 300 (rice) and 250 (wheat) kg N ha-1, and reduced levels, 150 (rice) and 125 (wheat) kg N ha-1, coated urea at two levels, 100 (rice) and 75 (wheat) kg N ha-1, and 150(rice) and 125 (wheat) kg N ha-1, and a control with no nitrogen arranged in a completely randomized design. The results under two rice-wheat rotations showed that N losses through both NH3 volatilization and runoff in the coated urea treatments were much lower than those in the urea treatments. In the urea treatments N runoff losses were significantly (P < 0.001) positively correlated (r = 0.851) with applied N. N concentration in surface water increased rapidly to maximum two days after urea application and then decreased quickly. However, if there was no heavy rain within five days of fertilizer application, the likelihood of N loss by runoff was not high. As the treatments showed little difference in N loss via percolation, nitrate N in the groundwater of the paddy fields was not directly related to N leaching. The total yieldof the two rice-wheat rotations in the treatment of coated urea at 50% conventional level was higher than that in the treatment of urea at the conventional level. Thus, coated urea was more favorable to rice production and environmental protection than urea.

  3. Milk urea nitrogen (MUN) tool reduces nitrogen emissions from dairy farms

    Science.gov (United States)

    The milk urea nitrogen (MUN) tool was developed to monitor dietary crude protein (CP) use and feed costs. MUN within the range of 12 to 10 mg/100 ml milk usually indicates the recommended dietary CP level of 16.5%. MUN levels greater than 12 mg/100 ml indicate dietary CP is being wasted and excreted...

  4. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion.

    Science.gov (United States)

    Weiner, I David; Mitch, William E; Sands, Jeff M

    2015-08-07

    Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance.

  5. The effect of monensin on milk production, milk urea nitrogen and ...

    African Journals Online (AJOL)

    Unknown

    Keywords: Monensin, milk production, milk composition, blood urea nitrogen, milk urea nitrogen, cow. *Present ..... Feedstuffs 68, 14. ... Lowe, L.B., Ball, G.J., Carruthers, V.R., Dobos, R.C., Lynch, G.A., Moate, P.R., Poole, P.R. & Valentine,.

  6. Ammonium nitrogen in fetuses of urea-treated sheep.

    Science.gov (United States)

    Yelverton, C C; Roller, M H; Swanson, R N

    1975-02-01

    Eight pregnant Southdown ewes were treated (by drench) with 12.5 ml of 3.3 M urea solution per kilogram of body weight, and ammonium nitrogen concentrations of blood and tissues of these ewes and their fetuses were measured and compared with those of control ewes (given water by drench) and their fetuses. Blood ammonium nitrogen (BAN) and tissue ammonium nitrogen (TAN) concentrations for liver, kidney, spleen, and muscle of ewes and fetuses were determined by an ion-exchange procedure. Samples of blood were collected before treatment, at 30, 90 and 150 minutes after treatment, and at death of the dam. The principal ewes had increasing BAN concentrations with time after drench, and their fetuses had significantly greater (P less than 0.01) BAN concentrations than fetuses from control ewes. All fetuses were alive after death of the dams and had lower TAN values than their dams. The differences in ammonia concentrations between ewes and fetuses were larger in the principal group than in the control group. Except for ewe muscle and fetal liver, all tissues of principals had significantly greater (P less than 0.01) TAN concentrations than those of controls. Muscle of principal ewes and hepatic tissues of their fetuses had greater (P less than 0.05) TAN concentrations than those of control ewes and their fetuses.

  7. Urea as a Nitrogen Source in a Black Tiger Shrimp (Penaeus monodon Closed Culture System

    Directory of Open Access Journals (Sweden)

    Supannee SUWANPAKDEE

    2010-06-01

    Full Text Available Urea [(NH22CO] is an organic compound that serves an important role in the metabolism of nitrogen-containing compound by animals. Urea is widely used in aquaculture systems. This study investigated the effects of urea on growth of Penaeus monodon. Shrimp were reared in 500 l fiber tanks. There was no exchange of water throughout the experiment. Shrimp with an average body weight of 10.99 ± 0.19 g were stocked at a density of 32 shrimp/m2 in 20 ppt diluted seawater and fed with 38 % protein diet for 9 weeks. Urea was added into the culture tanks at a concentration of 1.25 ppm once a week. The results show that urea slightly affects growth and survival of shrimp. Shrimp reared in the culture pond with added urea had a marginal better growth rate (p > 0.05 while the survival rate was significantly higher than the control group (p < 0.05. The urea in the closed culture tanks was shown to reduce the toxicity of ammonia in soil and promoted growth of plankton communities. Adding urea has no effect on water quality. This study concluded that urea is a potential nitrogen source in closed culture systems when the nitrogen input through the feeding regime is limited. It suggests that urea should be added at a concentration of 1.25 ppm once a week into culture systems with limiting nitrogen sources.

  8. Effect of nitrogen intake on urea appearance in patients receiving total parenteral nutrition and hemodialysis.

    Science.gov (United States)

    Mirtallo, J M; Fabri, P J

    1984-01-01

    Hemodialysis results in significant amino acid and protein losses and increases the patient's need for, and tolerance to, standard doses of protein. Since urea accumulation increases proportionately with increasing doses of protein in patients with normal renal function, urea accumulation may result when protein intake is increased to offset losses occurring in the dialysate. As a consequence, an increased requirement for dialysis may occur that might be poorly tolerated by the critically ill patient. This study was designed to determine the relationship between nitrogen intake and urea appearance in five patients requiring hemodialysis and total parenteral nutrition. Daily caloric and nitrogen intakes were determined. Urea appearance was calculated from measures of urine urea nitrogen excretion and daily body urea accumulation. Results of 108 measurements in treatment courses ranging from 23-79 days found that the average caloric intake (1984 +/- 55 calories/d) and nitrogen intake (11.0 +/- 0.4 g/d) resulted in a positive nitrogen balance (0.8 +/- 0.4 g/d) and a urea appearance rate of 9.4 +/- 0.8 g/d. Nitrogen intake correlated both with urea appearance (r = 0.59, p less than 0.001) and nitrogen balance (r = 0.49, p less than 0.001). Positive nitrogen balance was associated with improvements in measures of total iron binding capacity (p less than 0.05). Nitrogen intake directly relates to urea appearance, and positive nitrogen balance can be achieved without increasing dialysis requirements. In this group of patients, 28.3 calories per kg ideal body weight and 0.8 g of protein per kg ideal body weight were required to achieve nitrogen equilibrium.

  9. Farelo da vagem de algaroba associado a níveis de ureia na alimentação de ovinos: balanço de nitrogênio, N-ureico no plasma e parâmetros ruminais - doi: 10.4025/actascianimsci.v34i3.12759 Mesquite pod meal associated with levels of urea on feeding sheep: nitrogen balance, plasma urea-N and ruminal parameters - doi: 10.4025/actascianimsci.v34i3.12759

    Directory of Open Access Journals (Sweden)

    João Gonsalves Neto

    2012-05-01

    Full Text Available Objetivou-se neste trabalho avaliar os efeitos da inclusão de ureia em dietas contendo farelo da vagem de algaroba sobre o balanço de nitrogênio, N-uréico no plasma e parâmetros ruminais em ovinos. Foram utilizados oito animais, machos castrados, com peso médio de 33,5 kg, distribuídos em dois quadrados latinos 4 x 4. Os tratamentos constituíram da inclusão de níveis de ureia na dieta, sendo: 0; 0,5; 1,0 e 1,5% da MS total. A dieta foi fornecida como dieta total na relação volumoso:concentrado de 40:60 com base na MS total da dieta. Foi realizada a coleta total de urina e fezes e determinada a excreção de nitrogênio. Foi coletado sangue, seguido com a extração do plasma e determinação do N-uréico. Para avaliação do pH e N-amoniacal no líquido ruminal foram utilizados quatro animais fistulados no rúmen. A ingestão de N (31,68 g/dia e perdas vias fecal (7,94 g/dia e urinária (9,95 g/dia não sofreram alteração. As concentrações de N-amoniacal e N-uréico no plasma aumentaram de forma linear. O pH ruminal foi semelhante entre os tratamentos. A inclusão de uréia não influencia o balanço de nitrogênio, porém eleva as concentrações de N-amoniacal no rúmen e N-uréico no plasma podendo influenciar o gasto de energia no organismo.The goal of this study was to evaluate the effects of including urea in diets containing mesquite pod meal on nitrogen balance, plasma urea-N and ruminal parameters. Eight gelded males, with mean weight of 33.5 kg, were divided into two 4 x 4 Latin squares. Treatments consisted of following urea levels in diet: 0, 0.5, 1.0 and 1.5% of total dry matter. The diet was provided as total diet a 40:60 forage: concentrate ratio based on total diet DM. Total urine and feces were collected and nitrogen excretion was determined. Blood was collected, followed by plasma extraction and quantification of urea nitrogen. To evaluate pH and ammonia-N in rumen fluid, four rumen fistulated animals were used

  10. Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

    Institute of Scientific and Technical Information of China (English)

    WuGang; HeZhen-Li

    1998-01-01

    The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using 15N tracer method.When urea and ryegrass were applied alone or in combination,the percentage of N uptaken by ryegrass from labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of 200mgN.kg-1 and 100mgN.kg-1,respectively;combining application of ryegrass and ureareduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant,but the percentage of N residued in soil increased for urea and decreased for ryegrass.when urea and ryegrass were applied alone,the percentage of N residued in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%,and much more ryegrass N was incorporated into humus than urea N.

  11. A comparison of nitrogen utilization and urea metabolism between Tibetan and fine-wool sheep.

    Science.gov (United States)

    Zhou, J W; Mi, J D; Titgemeyer, E C; Guo, X S; Ding, L M; Wang, H C; Qiu, Q; Li, Z P; Long, R J

    2015-06-01

    To study metabolic adaptation to harsh foraging conditions, an experiment was conducted to characterize and quantify N utilization efficiency and urea metabolism in Tibetan and fine-wool sheep fed 4 levels of dietary N (11.0, 16.7, 23.1, and 29.2 g N/kg DM) in 2 concurrent 4 × 4 Latin square designs. Urea kinetics were determined using continuous intrajugular infusions of 15N15N-urea. Urinary excretions of total N and urea N increased linearly (P < 0.001) with dietary N and were not different between breeds (P ≥ 0.37). Fecal N excretion increased with dietary N for Tibetan sheep but not for fine-wool sheep (linear dietary N × breed; P < 0.05). Nitrogen retention (both amount per day and percentage of N intake) increased with increasing dietary N concentration (P < 0.001), and the rates of increase were greater in fine-wool than in Tibetan sheep (linear dietary N × breed and cubic dietary N × breed; P < 0.05). In Tibetan sheep, N retention as a percentage of intake was greatest for diets containing 16.7 g N/kg DM, whereas it was maximal for fine-wool sheep when the diet contained 23.1 g N/kg DM. Urea N entry rate, urea N recycled to the gastrointestinal tract (GIT), and urea N returned to the ornithine cycle all increased with dietary N (P < 0.05), and all were greater in Tibetan than fine-wool sheep for the 11.0 g N/kg DM diet but were greater in fine-wool than Tibetan sheep for the diet with 29.2 g N/kg DM (linear dietary N × breed; P < 0.05). Urea N excreted in feces, both amount and fraction of GIT entry rate, was less in Tibetan than fine-wool sheep for the 11.0 and 16.7 g N/kg DM diets but similar for diets with 23.1 or 29.2 g N/kg DM (linear dietary N × breed; P < 0.01). For the lowest-protein diet, the fraction of urea N production recycled to the GIT was greater in the Tibetan than fine-wool sheep (88% vs. 82%), but for the diet with 29.2 g N/kg DM it was greater for fine-wool than Tibetan sheep (46% vs. 39%; linear dietary N × breed; P < 0

  12. Effects of Controlled Release Urea on Wheat Yield and Nitrogen Utilization Efficiency Under Different Applied Conditions

    Directory of Open Access Journals (Sweden)

    XIA Wei-guang

    2014-02-01

    Full Text Available The field trial was conducted to study the effects of different nitrogen fertilizer applications on winter wheat yield, nitrogen utilization efficiency and economic benefit. 7 treatments were designed as CK(no nitrogen fertilizer applied, 100%PU10/0(conventional urea applied before sowing, N rate was 240 kg·hm-2, 100%PU6/4(conventional urea applied before sowing and at jointing with the ratio of 6∶4, N rate was 240 kg·hm-2, 80%PU6/4(conventional urea applied before sowing and at jointing with the ratio of 6∶4, N rate was 192 kg·hm-2, 100%CRU(resin coated controlled release urea applied before sowing, N rate was 240 kg·hm-2, 80%CRU(resin coated controlled release urea applied before sowing, N rate was 192 kg·hm-2, and 40%CRU+40%PU(resin coated controlled release urea and conventional urea applied before sowing, N rate was 192 kg·hm-2. The results showed that no matter on the efficiency of yield or that of nitrogen, resin coated controlled-release urea(CRU was better when compared with conventional urea(PU. Especially, the combined application treatment(40%CRU+40%PUwas the best with achieving the highest wheat yield of 7 709 kg·hm-2, the highest N fertilizer utilization efficiency of 36.44% and the maximum net income of 15 946 yuan·hm-2. And it could not only increase winter wheat yield with reducing the nitrogen fertilizer application, but also improve N fertilizer utilization efficiency and owe the highest ratio of output to input. Therefore, the combined application of the resin coated controlled-release urea and conventional urea(40%CRU+40%PUwas the optimal nitrogen fertilizer treatment under the conditions of this experiment.

  13. Methodology for concurrent determination of urea kinetics and the capture of recycled urea nitrogen by ruminal microbes in cattle.

    Science.gov (United States)

    Wickersham, T A; Titgemeyer, E C; Cochran, R C

    2009-03-01

    We measured the incorporation of recycled urea-nitrogen (N) by ruminal microbes, using five ruminally and duodenally fistulated steers (237 kg) fed low-quality grass hay (47 g crude protein/kg dry matter (DM)). Three received 1 kg/day of soybean meal (SBM) and two received no supplemental protein (control). The experiment was 15 days long. Background enrichments of 15N were measured on day 9 and continuous jugular infusion of 0.12 g/day [15N15N]urea began on day 10. Daily samples of urine, feces, ruminal bacteria and duodenal digesta from days 10 through 14 were used to determine plateaus in 15N enrichment. Duodenal and bacterial samples collected on day 15 were used to measure duodenal N flows. Bacterial N flow was calculated as duodenal N flow multiplied by duodenal 15N enrichment divided by bacterial 15N enrichment. Bacterial N from recycled urea-N was calculated as bacterial N flow multiplied by bacterial 15N enrichment divided by urinary urea 15N enrichment. Urinary enrichment of [15N15N]urea plateaued within 24 h, whereas 14N15N urea plateaued within 48 h of [15N15N]urea infusion. Bacteria reached a plateau in 15N enrichment within 24 h and duodenal samples within 48 h. Urea production was 17.6 g of urea-N/day for control and 78.0 g/day for SBM. Gut entry was 0.99 g of urea-N/g of urea-N produced for control and 0.87 g/g for SBM. Incorporation of recycled N into microbial N was 9.0 g of N/day for control and 23.0 g/day for SBM. Recycled urea-N accounted for 0.33 g of N/g of microbial N at the duodenum for control and 0.27 g/g for SBM. Our methods allowed measurement of incorporation of recycled urea-N into ruminal microbial N.

  14. Effects of Controlled Release Urea on Wheat Yield and Nitrogen Utilization Efficiency Under Different Applied Conditions

    OpenAIRE

    XIA Wei-guang; Wu, Ji; GAO Feng-me; WANG, YUN-QING; GUO Xi-sheng

    2014-01-01

    The field trial was conducted to study the effects of different nitrogen fertilizer applications on winter wheat yield, nitrogen utilization efficiency and economic benefit. 7 treatments were designed as CK(no nitrogen fertilizer applied), 100%PU10/0(conventional urea applied before sowing, N rate was 240 kg·hm-2), 100%PU6/4(conventional urea applied before sowing and at jointing with the ratio of 6∶4, N rate was 240 kg·hm-2), 80%PU6/4(conventional urea applied before sowing and at jointing w...

  15. Effects of Controlled Release Urea on Wheat Yield and Nitrogen Utilization Efficiency Under Different Applied Conditions

    OpenAIRE

    XIA Wei-guang; Wu, Ji; GAO Feng-me; WANG Yun-qing; GUO Xi-sheng

    2014-01-01

    The field trial was conducted to study the effects of different nitrogen fertilizer applications on winter wheat yield, nitrogen utilization efficiency and economic benefit. 7 treatments were designed as CK(no nitrogen fertilizer applied), 100%PU10/0(conventional urea applied before sowing, N rate was 240 kg·hm-2), 100%PU6/4(conventional urea applied before sowing and at jointing with the ratio of 6∶4, N rate was 240 kg·hm-2), 80%PU6/4(conventional urea applied before sowing and at jointing w...

  16. The Chinese soft-shelled turtle, Pelodiscus sinensis, decreases nitrogenous excretion, reduces urea synthesis and suppresses ammonia production during emersion.

    Science.gov (United States)

    Ip, Yuen K; Lee, Serene M L; Wong, Wai P; Chew, Shit F

    2013-05-01

    The objective of this study was to examine the effects of 6 days of emersion on nitrogen metabolism and excretion in the Chinese soft-shelled turtle, Pelodiscus sinensis. Despite having a soft shell with a cutaneous surface that is known to be water permeable, P. sinensis lost only ~2% of body mass and was able to maintain its hematocrit and plasma osmolality, [Na(+)] and [Cl(-)] during 6 days of emersion. During emersion, it ameliorated water loss by reducing urine output, which led to a reduction (by 29-76%) in ammonia excretion. In comparison, there was a more prominent reduction (by 82-99%) in urea excretion during emersion due to a lack of water to flush the buccopharyngeal epithelium, which is known to be the major route of urea excretion. Consequently, emersion resulted in an apparent shift from ureotely to ammonotely in P. sinensis. Although urea concentration increased in several tissues, the excess urea accumulated could only account for 13-22% of the deficit in urea excretion. Hence, it can be concluded that a decrease (~80%) in urea synthesis occurred in P. sinensis during the 6 days of emersion. Indeed, emersion led to significant decreases in the activity of some ornithine-urea cycle enzymes (argininosuccinate synthetase/argininosuccinate lyase and arginase) from the liver of P. sinensis. As a decrease in urea synthesis occurred without the accumulation of ammonia and total free amino acids, it can be deduced that ammonia production through amino acid catabolism was suppressed with a proportional reduction in proteolysis in P. sinensis during emersion. Indeed, calculated results revealed that there could be a prominent decrease (~88%) in ammonia production in turtles after 6 days of emersion. In summary, despite being ureogenic and ureotelic in water, P. sinensis adopted a reduction in ammonia production, instead of increased urea synthesis, as the major strategy to ameliorate ammonia toxicity and problems associated with dehydration during

  17. Nitrogen fertilization in corn with urea coated with different sources of polymers

    Directory of Open Access Journals (Sweden)

    Márcio Valderrama

    2014-02-01

    Full Text Available In view of theoretic increase in efficiency of nitrogen fertilizers for controlled release, this study aimed to evaluate the effect of nitrogen, using conventional urea and ureas coated by different polymers, in the leaf N content, leaf chlorophyll index, components production and grain yield of irrigated corn in growing season and second crop in the savannah region. The experiments were conducted at experimental area belonging to UNESP – Ilha Solteira, located in Selvíria – MS in a dystrophic Red Latosol (Haplustox, clayey texture. The statistical design was randomized blocks, with four repetitions, in a 4 x 4 factorial arrangement, being four nitrogen doses (0, 40, 80 and 120 kg ha-1 applied at sidedressing and four urea sources (a conventional urea and three coated with polymers in different compositions and concentrations. The coated ureas are not efficient under the soil and climate conditions studied of the savanna, because they provided results similar to the conventional urea for the production components and grain yield of corn in the first and second crop. The increment of nitrogen doses increase linearly the leaf N content and grain yield of corn in the first and second crop.

  18. Effect of supplemental nitrogen from urea on digestibility, rumen fermentation pattern, microbial populations and nitrogen balance in growing goats

    Directory of Open Access Journals (Sweden)

    Wanwisa Ngampongsai

    2008-08-01

    Full Text Available For this study, four Thai Native (TN x Anglo Nubian (AN crossbred growing goats with an average liveweight of 19.0+1 kg were randomly used in a 4x4 Latin square design to determine the effect of supplemental nitrogen from urea on digestibility, rumen fermentation pattern, microbial populations and nitrogen balance in growing goats. Fresh elephant grass(FEG was offered ad libitum as the roughage. Four dietary treatments with supplemental nitrogen from urea were T1 = urea at 0% cassava chip, (CC = 30%, T2 = urea at 1% (CC = 40%, T3 = urea at 2% (CC = 50% and T4 = urea at 3% (CC = 60%,respectively. Based on this experiment, it was found that there was no significant difference (p>0.05 among treatment groups regarding nutrient intake (OMI, CPI, NDFI and ADFI and digestion coefficients of nutrients (DM, OM, CP, NDF and ADF, while digestible nutrient intake of CP (g/d was affected by increasing urea levels. Ruminal volatile fatty acidprofiles were similar among treatments. Moreover, rumen microorganism populations were not affected (p>0.05 by increasing urea levels. The amount of N absorption and retention were similar among treatments, except for T4 which tended to be slightly lower in N absorption as compared to control diet, but higher N output retained (% of N intake than the control-fed goats. From the overall results, it can be concluded that a higher level of urea (3% could be used with a high level of CC (60% in concentrate when fed with FEG and it was found to be a good approach to exploiting the use of local feedresources for goat production.

  19. Slow release coating remedy for nitrogen loss from conventional urea: a review.

    Science.gov (United States)

    Naz, Muhammad Yasin; Sulaiman, Shaharin Anwar

    2016-03-10

    Developing countries are consuming major part of the global urea production with an anticipated nitrogen use efficiency of 20 to 35%. The release of excess nitrogen in the soil is not only detrimental to the environment but also lessens the efficiency of the conventional urea. The urea performance can be enhanced by encapsulating it with slow release coating materials and synchronizing the nutrients' release with the plant up-taking. However, the present cost of most of the coated fertilizers is considerably higher than the conventional fertilizers. The high cost factor prevents their widespread use in mainstream agriculture. This paper documents a review of literature related to the global urea market, issues pertaining to the conventional urea use, natural and synthetic materials for slow release urea and fluidized bed spray coating process. The aim of the current review is to develop technical understanding of the conventional and non-conventional coating materials and associated spray coating mechanism for slow release urea production. The study also investigated the potential of starch as the coating material in relation to the coatings tested previously for controlled release fertilizers.

  20. EFFECT OF UREA WITH NUTRISPHERE-N POLYMER IN FALL AND SPRING NITROGEN APPLICATIONS FOR CORN

    Directory of Open Access Journals (Sweden)

    Pawel Wiatrak

    2014-01-01

    Full Text Available Polymer coated urea may be a viable option to improve Nitrogen (N uptake and corn (Zea mays L. grain yields, especially in areas with relatively high soil N loss. The objective of this study was to evaluate the effect of two urea application timings (fall and spring and three N rates (90, 180 and 270 kg N ha-1 with and without Nutrisphere-N polymer on irrigated corn near Scandia, KS from 2006 to 2008. Compared to uncoated N, urea coated with Nutrisphere-N improved grain yields by 18.3% with applications of 180 kg N ha-1 in the fall. Application of urea with Nutrisphere-N in the spring produced similar grain yields for treatments with and without Nutrisphere-N. Corn ear-leaf content was highest with urea applied at 90 kg N ha-1 in the fall and urea coated with Nutrisphere-N at 180 and 240 kg N ha-1 in the fall and spring. Grain N content was highest from urea coated with Nutrisphere-N application at 270 kg N ha-1 in the fall and spring. Compared to untreated urea, Nutrisphere-N improved grain N removal by 29.6% at 180 kg N ha-1 applied in the fall. Spring urea application with Nutrisphere-N produced similar grain N removal compared to urea without Nutrisphere-N. Generally, adding Nutrisphere-N to urea fertilizer may help improve N content in leaves and grain and increase grain yields of corn, especially with the fall N applications having higher potential of soil N loss.

  1. Nitrogen digestion and urea recycling in Hokkaido native horses fed hay-based diets.

    Science.gov (United States)

    Obitsu, Taketo; Hata, Hiroshi; Taniguchi, Kohzo

    2015-02-01

    Nitrogen (N) digestion and urea-N metabolism in Hokkaido native horses fed roughage-based diets containing different types and levels of protein sources were studied. Horses (173 ± 4.8 kg) fitted with an ileum cannula were fed four diets consisting of 100% timothy hay (TH), 88% TH and 12% soybean meal (SBM), 79% TH and 21% SBM, and 51% TH and 49% alfalfa hay at 2.2% of body weight. Dietary protein content varied from 5% to 15% of dry matter. Apparent N digestibilities in the pre-cecum and total tract for the TH diet were lower than those for other diets. However, the proportion of post-ileum N digestion to N intake was not affected by the diets. Urea-N production was linearly related to N intake, but gut urea-N entry was not affected by the diets. The proportion of gut urea-N entry to urea-N production tended to be higher for the TH diet (57%) than the two SBM diets (39%). Anabolic use of urea-N entering the gut was not affected by the diets (20-36% of gut urea-N entry). These results indicate that urea-N recycling provides additional N sources for microbial fermentation in the hindgut of Hokkaido native horses fed low-quality roughages.

  2. Altered Nitrogen Balance and Decreased Urea Excretion in Male Rats Fed Cafeteria Diet Are Related to Arginine Availability

    Directory of Open Access Journals (Sweden)

    David Sabater

    2014-01-01

    rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

  3. Fate of Urea Nitrogen Applied to Rape Grown on a Red Soil and Efficiency of Urea in Raising Rape Yield

    Institute of Scientific and Technical Information of China (English)

    CAIGUI-XIN; WUYI-WEI; 等

    1995-01-01

    Fate of urea nitrogen(N) applied to rape grown on a red soil was investigated by the 15N mass balance technique.and efficiency of urea and effect of nutrients balance in raising rape yield were investigated in a field plot experiment.One hundred and thirty -eight kg N/ha,86kg N/ha as basal dressing and 52 kg N/ha as top dressing,was applied with band application technique.The experiment was conducted in the southeast of china ,near Yingtan City,Jianxi Province.Results from 15N mass balance study showed that when urea urea was applied as basal dressing the plant recovery was 44.0% of the applied N for Treatment T (with application of N,P,K,B and lime),Plant recoveries were 38.0%-40.5% for Treatments-K,-B-lime and+RS(without application of K,B or lime as well as with additional rice straw compared with Teatment T),which were not significantly different from Treatment T.In contrast ,plant recovery was only 5.1% for Treatment-P(without application of P), indicating that P was the factor limiting N uptake by rape.However,N remaining in 0-0.30 m soil was high up to 71.6% for Treatment-P,while the corresponding data were 33.0%-42.6% for the other treatments.The total recovery of applied N(including plant recovery and N remaining in 0-0.60 m soil) was 91.5% for Treatment T when urea was applied as basal dressing,while almost all the applied N was recovered when ureawas applied as top drssing,It was suggested that N loss was greatly controlled by using band application method in this experiment.Results from the field plot experiment field plot experiment showed that N supply capacity of this red soil was very low,and the efficiency of the applied N was quite high,7.1kg rape seed was increased by application of one kg N for Treatment T.Nitrogen and phosphorus were the key factors limiting rape yield,and the yield was very low when neither of them was applied.The yield in Treatment-K was significantly lower than that in Treatment T,With the former accounting for 77% of the

  4. Transcriptomic analysis highlights reciprocal interactions of urea and nitrate for nitrogen acquisition by maize roots.

    Science.gov (United States)

    Zanin, Laura; Zamboni, Anita; Monte, Rossella; Tomasi, Nicola; Varanini, Zeno; Cesco, Stefano; Pinton, Roberto

    2015-03-01

    Even though urea and nitrate are the two major nitrogen (N) forms applied as fertilizers in agriculture and occur concomitantly in soils, the reciprocal influence of these two N sources on the mechanisms of their acquisition are poorly understood. Therefore, molecular and physiological aspects of urea and nitrate uptake were investigated in maize (Zea mays), a crop plant consuming high amounts of N. In roots, urea uptake was stimulated by the presence of urea in the external solution, indicating the presence of an inducible transport system. On the other hand, the presence of nitrate depressed the induction of urea uptake and, at the same time, the induction of nitrate uptake was depressed by the presence of urea. The expression of about 60,000 transcripts of maize in roots was monitored by microarray analyses and the transcriptional patterns of those genes involved in nitrogen acquisition were analyzed by real-time reverse transcription-PCR (RT-PCR). In comparison with the treatment without added N, the exposure of maize roots to urea modulated the expression of only very few genes, such as asparagine synthase. On the other hand, the concomitant presence of urea and nitrate enhanced the overexpression of genes involved in nitrate transport (NRT2) and assimilation (nitrate and nitrite reductase, glutamine synthetase 2), and a specific response of 41 transcripts was determined, including glutamine synthetase 1-5, glutamine oxoglutarate aminotransferase, shikimate kinase and arogenate dehydrogenase. Also based on the real-time RT-PCR analysis, the transcriptional modulation induced by both sources might determine an increase in N metabolism promoting a more efficient assimilation of the N that is taken up.

  5. Kinetic of Adsorption of Urea Nitrogen onto Chitosan Coated Dialdehyde Cellulose under Catalysis of Immobilized Urease

    Institute of Scientific and Technical Information of China (English)

    Zu Pei LIANG; Ya Qing FENG; Zhi Yan LIANG; Shu Xian MENG

    2005-01-01

    The adsorption of urea nitrogen onto chitosan coated dialdehyde cellulose (CDAC)under catalysis of immobilized urease in gelatin membrane (IE) was studied in batch system. The pseudo first-order and second-order kinetic models were used to describe the kinetic data, and the rate constants were evaluated. The experimental data fitted well to the second-order kinetic model.

  6. Urea hydrolysis and recovery of nitrogen and phosphorous as MAP from stale human urine

    Institute of Scientific and Technical Information of China (English)

    LIU Zhigang; ZHAO Qingliang; WANG Kun; LEE Duujong; QIU Wei; WANG Jianfang

    2008-01-01

    Laboratory-scale tests for magnesium ammonium phosphate (MAP) precipitation following urea hydrolysis of human urine were conducted using orthogonal experiment design. The effects of initial pH, temperature and the volumetric ratios of stale urine to fresh urine, on urea hydrolysis in urine were studied to determine the final hydrolysis time to recover most nitrogen from separated human urine by MAP. With a volumetric ratio of stale to fresh urine >10% and at temperature of 20℃ and above, urea hydrolysis could be completed in two days. Alkaline pH inhibited urea hydrolysis progress. The final pHs were all around 9.0 following urine hydrolysis, while the suspension pH might act as an indicator to detect the start and extent of urea hydrolysis. Over 95% of ammonium nitrogen and over 85% of phosphorus from hydrolyzed urine as MAP precipitate were obtained using MgCl2·6H2O and Na2HPO4·12H2O as precipitation agents at pH 8.5, molar ratio of Mg2+:NH4+-N:PO43--P at (1.2--1.3):1:1, mixing speed of 120 r/min, and precipitation time and reaction time of 3 h and 15 min, respectively. The precipitate has a structure resembling pure MAP crystal.

  7. Nitrogen waste from rainbow trout (Oncorhynchus mykiss) with particular focus on urea

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Larsen, Bodil Katrine; Pedersen, Per Bovbjerg

    2015-01-01

    Particulate and dissolved nitrogen (N) waste components are removed in recirculating aquaculture systems (RAS) using different cleaning technologies, and to dimension and optimize their removal efficiency requires that the expected daily load of the different waste forms can be estimated. Using...... a laboratory, mass-balance approach, the current study examined the effects of commercially applied feeding levels on the loading of different N waste forms, including daily fluctuations in dissolved total nitrogen (TN), total ammonia nitrogen (TAN), urea-N, and non-characterized, dissolved N deriving from...... juvenile rainbow trout (Oncorhynchus mykiss). In addition, the study examined whether there was a removal of urea-N across a moving bed biofilter operated as end-of-pipe under commercial conditions. The laboratory, mass-balance study showed that there were no effects of feeding levels (1.3, 1.5 or 1...

  8. CsNIP2;1 is a Plasma Membrane Transporter from Cucumis sativus that Facilitates Urea Uptake When Expressed in Saccharomyces cerevisiae and Arabidopsis thaliana.

    Science.gov (United States)

    Zhang, Lu; Yan, Jiapei; Vatamaniuk, Olena K; Du, Xiangge

    2016-03-01

    Urea is an important source of nitrogen (N) for the growth and development of plants. It occurs naturally in soils, is the major N source in agricultural fertilizers and is an important N metabolite in plants. Therefore, the identification and characterization of urea transporters in higher plants is important for the fundamental understanding of urea-based N nutrition in plants and for designing novel strategies for improving the N-use efficiency of urea based-fertilizers. Progress in this area, however, is hampered due to scarce knowledge of plant urea transporters. From what is known, urea uptake from the soil into plant roots is mediated by two types of transporters: the major intrinsic proteins (MIPs) and the DUR3 orthologs, mediating low- and high-affinity urea transport, respectively. Here we characterized a MIP family member from Cucumis sativus, CsNIP2;1, with regard to its contribution to urea transport. We show that CsNIP2;1 is a plasma membrane transporter that mediates pH-dependent urea uptake when expressed in yeast. We also found that ectopic expression of CsNIP2;1 improves growth of wild-type Arabidopsis thaliana and rescues growth and development of the atdur3-3 mutant on medium with urea as the sole N source. In addition, CsNIP2;1 is transcriptionally up-regulated by N deficiency, urea and NO3 (-). These data and results from the analyses of the pattern of CsNIP2;1 expression in A. thaliana and cucumber suggest that CsNIP2;1 might be involved in multiple steps of urea-based N nutrition, including urea uptake and internal transport during N remobilization throughout seed germination and N delivery to developing tissues.

  9. Sodium Phenylbutyrate Decreases Plasma Branched-Chain Amino Acids in Patients with Urea Cycle Disorders

    OpenAIRE

    Burrage, Lindsay C.; Jain, Mahim; Gandolfo, Laura; Lee, Brendan H.; Nagamani, Sandesh CS

    2014-01-01

    Sodium phenylbutyrate (NaPBA) is a commonly used medication for the treatment of patients with urea cycle disorders (UCDs). Previous reports involving small numbers of patients with UCDs have shown that NaPBA treatment can result in lower plasma levels of the branched-chain amino acids (BCAA) but this has not been studied systematically. From a large cohort of patients (n=553) with UCDs enrolled in Longitudinal Study of Urea Cycle Disorders, a collaborative multicenter study of the Urea Cycle...

  10. Effect of urea and nickel on growth, physiological traits and total nitrogen concentration of lettuce in hydroponic culture

    Directory of Open Access Journals (Sweden)

    H. Nazari Mamaqani

    2016-02-01

    Full Text Available Nitrate fertilizers are common source of nitrogen (N in nutrient solutions. Substitution of urea with nitrate could reduce this dependence. Also, nickel (Ni is essential for activation of urease in plants fed with urea. For this aim, a factorial experiment was conducted in a completely randomized design with four replicates. Urea in five levels (0, 25, 50, 75 and 100 mg/L and Ni in two levels (0 and 2 mg/L were used for lettuce (Lactuca sativa cv. Siyahoo in hydroponics. The results showed that the highest fresh and dry weight of leaves and stem were obtained in 50 mg/L urea treatment. Leaf area was reduced in treatments having more than 25 mg/L urea concentration. The highest chlorophyll index and maximal quantum yield of PS II photochemistry efficiency (Fv/Fm were obtained in 100 and 75 mg/L urea, respectively. Total nitrogen concentration of leaves was increased significantly with increasing urea concentration; plants treated with 100 mg/L urea had the highest total nitrogen concentration. Nickel application reduced yield and physiological traits of lettuce; while it had no significant effect on total nitrogen concentration.

  11. Medium-Ring Nitrogen Heterocycles through Migratory Ring Expansion of Metalated Ureas.

    Science.gov (United States)

    Hall, Jessica E; Matlock, Johnathan V; Ward, John W; Gray, Katharine V; Clayden, Jonathan

    2016-09-05

    Simple benzo-fused nitrogen heterocycles (indolines, tetrahydroquinolines, and their homologues) undergo migratory ring expansion through deprotonation of their benzylic urea derivatives with lithium diisopropylamide (LDA) in the presence of N,N'-dimethylpropylideneurea (DMPU). The products of the reactions are benzodiazepines, benzodiazocines, and their homologues, with ring sizes of 8-12. The reactions tolerate a range of substituent patterns and types, and may exhibit enantiospecificity or diastereoselectivity. Considerable complexity is rapidly generated in an efficient synthesis of these otherwise difficult-to-obtain medium-ring nitrogen heterocycles.

  12. Concentrações de nitrogênio na dieta, no sangue e no leite de vacas lactantes no período pós-parto Effects of different dietary crude protein levels on plasma and milk urea nitrogen on post calving lactating dairy cows

    Directory of Open Access Journals (Sweden)

    Carlos de Sousa Lucci

    2006-02-01

    Full Text Available Foram utilizadas 24 vacas leiteiras em um delineamento em blocos casualizados com o objetivo de comparar três tratamentos compostos por dietas isoenergéticas, distintas quanto aos teores de proteína bruta (PB: P100 = 100%, P130 = 133% e P166 = 166% das exigências descritas pelo NRC (1989. Os acréscimos de PB foram obtidos como equivalentes protéicos mediante adição de uréia pecuária. Semanalmente, coletaram-se amostras dos alimentos, do leite e do sangue dos animais, desde os 30 dias anteriores até os 60 posteriores ao parto. As produções de leite e o peso das vacas foram registrados semanalmente. As concentrações de nitrogênio uréico foram determinadas nas amostras de leite (NUL e de plasma (NUP. As produções médias de leite, por vaca e por dia, foram iguais a 12,4; 13,3; e 13,4 kg nos tratamentos P100, P133 e P166, respectivamente, aumentando de forma linear com o emprego de maiores quantidades de equivalente protéico nas rações. As concentrações de NUP e NUL, em mg/dL, aumentaram linearmente com o incremento de equivalente protéico nas dietas, segundo as equações Y= 16,83 + 0,202 X e Y= 13,73 + 0,219 X, respectivamente. A correlação entre valores de NUP e NUL foi significativa, indicando que tanto os valores de NUP quanto os de NUL podem servir como indicadores das quantidades dietéticas de proteína degradável no rúmen, em vacas lactantes, e que valores mais elevados de equivalente em PB resultam em maiores produções de leite.Twenty-four lactating dairy cows were assigned to a completely randomized block design to compare the effects of isoenergetic diets but different crude protein (CP levels: P100- 100%, P133- 133% or P166- 166% of the NRC (1989 requirements on the concentrations of urea nitrogen in plasma (PUN and milk (MUN. Increasing levels of CP were obtained by adding urea to the diet. Feeds, milk, and blood were all collected weekly from 30 days before to 60 days after parturition. Milk yield and

  13. Hygroscopicity and ammonia volatilization losses from nitrogen sources in coated urea

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    Letícia de Abreu Faria

    2014-06-01

    Full Text Available Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; and by stabilized fertilizers, which prolong the period during which N remains in the amide or ammonia forms by urease inhibitors. This study evaluated the hygroscopicity of and ammonia volatilization from urea coated with boric acid and copper sulfate or with sulfur. The hygroscopicity of the sources was evaluated over time after exposure to five levels of relative humidity (RH and volatilization evaluated after application to the soil surface covered with sugarcane trash. Ammonium nitrate has a low potential for volatilization losses, but is highly hygroscopic. Although coating with boric acid and copper sulfate or elemental sulfur reduced the critical humidity level of urea, the delay in the volatilization process is a potential positive factor.

  14. Solubility Characteristics and Slow-Release Mechanism of Nitrogen from Organic-Inorganic Compound Coated Urea

    Directory of Open Access Journals (Sweden)

    Hongtao Zou

    2015-01-01

    Full Text Available A soil incubation method was used to investigate the solubility characteristics and slow-release mechanism of organic-inorganic compound coated urea at temperature of 10, 20, and 30°C. The membrane microstructure with and without incubation was tested via scanning electron microscopy (SEM. Slow release of nitrogen (N from different inorganic minerals was analysed by the activation energy from the nutrient solubility system. The rate of nitrogen solubility increased with temperature increasing. The first-order reaction kinetic equation described the solubility process of coated urea. The rate constant k also increased with temperature increasing. Moreover, the SEM images showed that the microstructure of the coating layer changed into a flocculent structure and the number of tiny pores and holes on the membrane surface increased significantly with temperature increasing, which increased N solubility rate. The Arrhenius equation indicated that activation energy was closely related to k during the solubility process; the activation energy was reduced with k rising, which resulted in N solubility rate increasing. Overall, the N solubility rate of coated urea was affected by temperature.

  15. An improved analytical method for the determination of urea nitrogen isotopomers in biological samples utilizing continuous flow isotope ratio mass spectrometry.

    Science.gov (United States)

    Marini, Juan C; Attene-Ramos, Matias Sebastian

    2006-01-01

    Over the past few years numerous dual inlet isotope ratio mass spectrometry (IRMS) applications have been adapted to continuous flow systems which allow the automation of sample admission and a higher throughput. The isotopomer analysis of urea nitrogen by IRMS requires the offline conversion of urea into nitrogen gas before analysis. The oxidation of urea with LiOBr results in the monomolecular degradation of urea, which preserves the identity of the parent urea molecule, and has to be conducted under vacuum to prevent contamination with atmospheric nitrogen. We have developed an offline system of urea degradation utilizing disposable Exetainers, in which atmospheric nitrogen is displaced by helium. Recovery of urea nitrogen was linear within the range of the standards tested (0 to 420 microg nitrogen) and standard curves for 15N15N-urea standards showed high coefficients of determination (R2 > 0.9998). A small portion of urea degrades in a non-monomolecular fashion and has been shown to depend on the concentration of urea in the sample. Long-term storage of prepared samples showed a decline in 15N15N enrichment, suggesting air contamination. However, samples were stable for 24 h, which allows for the analysis of large sample batches. Interest in urea metabolism, particularly in ruminant species, has increased recently due to the environmental implications of urea and nitrogen excretion by farm animals. This novel analytical method will allow for accurate measurements and the rapid throughput needed in order to support these field studies.

  16. Effect of Lime Nitrogen on the Transformation of Urea in Soils

    Institute of Scientific and Technical Information of China (English)

    HENIAN-ZU; YUSHEN; 等

    1995-01-01

    Laboratory incubation experiment was conducted to study the effect of lime nitrogen(LN) on transfor-mation of urea-N in three paddy soils.The results showed that LN had an inhibitory effect on urease activity in these soils especially in the first 5 days.and that in the first 20 days of incubation,the amount of NH4+-N derived from urea was lower in the soil with LN than in the soil without LN,While after 30 days the amount of NH4+-N was higher in the mature haplic paddy soil developed on Quaternary red clay (MHPS)with LN than that in the soil without LN.The amount of NH3-N volatilized was decreased in the earlier stage and increased in the later stage of incubation in the MHPS by the addition of LN.

  17. Effect of Incorporation of Wheat Straw and Urea into Soil on Biomass Nitrogen and Nitrogen—Supplying Characteristics of Paddy Soil

    Institute of Scientific and Technical Information of China (English)

    SHENQI-RONG; XUSHOU-MING; 等

    1993-01-01

    Pot experiments were carried out to study the effect of incorporation of wheat straw and/ or urea into soil on biomass nitrogen and mineral nitrogen and its relation to the growth and yield of rice.The combined appliation of wheat straw and urea increased much more biomass nitrogen in soil than the application of wheat straw or urea alone and consequently increased the immobilization of urea nitrogen added and reduced the loss of urea nitrogen.An adequate nitrogen-supplying process to rice plant could be obtained if C/ N ratio of the material added was about 20.The three yield components of rice were affected significantly by the status of nitrogen supplying.More than 30mg N/ kg soil of mineral nitrogen at effective tillering stage,panicle initiation stage and filling stage should be maintained in order to get high rice yield,though the criteria varied with the different experimental conditions.

  18. Sulfonamide antibiotic removal and nitrogen recovery from synthetic urine by the combination of rotating advanced oxidation contactor and methylene urea synthesis process.

    Science.gov (United States)

    Fukahori, S; Fujiwara, T; Ito, R; Funamizu, N

    2015-01-01

    The combination of nitrogen recovery and pharmaceutical removal processes for livestock urine treatment were investigated to suppress the discharge of pollutants and recover nitrogen as resources. We combined methylene urea synthesis from urea and adsorption and photocatalytic decomposition of sulfonamide antibiotic using rotating advanced oxidation contactor (RAOC) contained for obtaining both safe fertilizer and reclaimed water. The methylene urea synthesis could recover urea in synthetic urine, however, almost all sulfonamide antibiotic was also incorporated, which is unfavorable from a safety aspect if the methylene urea is to be used as fertilizer. Conversely, RAOC could remove sulfonamide antibiotic without consuming urea. It was also confirmed that the methylene urea could be synthesized from synthetic urine treated by RAOC. Thus, we concluded that RAOC should be inserted prior to the nitrogen recovery process for effective treatment of urine and safe use of methylene urea as fertilizer.

  19. Reducing nitrogen losses through ammonia volatilization and surface runoff to improve apparent nitrogen recovery of double cropping of late rice using controlled release urea.

    Science.gov (United States)

    Li, Pengfei; Lu, Jianwei; Hou, Wenfeng; Pan, Yonghui; Wang, Yang; Khan, Muhammad Rizwan; Ren, Tao; Cong, Rihuan; Li, Xiaokun

    2017-04-01

    Controlled release fertilizer can reduce nitrogen losses to the environment while increasing grain yield and improving apparent nitrogen recovery (ANR) of rice. However, few studies have evaluated the comparative efficacy of different polymer-coated urea products on nitrogen (N) losses, ANR, and N uptake of rice. A 2-year field experiment was conducted to compare the effects of three different types of polymer-coated urea fertilizer on nitrogen losses through NH3 volatilization and surface runoff to the environment, ANR, grain yield, and N uptake as compared to conventional urea of rice. Six treatments including (1) control with 0 kg N ha(-1) (CK), (2) basal application of urea (Ub), (3) split application (Us) of urea (50% at transplanting, 25% at tillering, and 25% at panicle stages), (4) CRU-1 (polyurethane-coated urea), (5) CRU-2 (degradable polymer-coated urea), and (6) CRU-3 (water-based polymer-coated urea) all applied at 165 kg N ha(-1). It was found that CRU-2 resulted in the highest grain yield and panicle numbers among the N fertilization treatments in 2013 and 2014. Applying CRU could help increase N uptake in rice, reduce N losses through NH3 volatilization and surface runoff, and hence improve ANR. Its single dose can meet the nutrient demand of the rice plant. Controlled release urea could be adopted as an effective mitigation alternative to retard N losses through NH3 volatilization and surface runoff while improving ANR of double cropping of late rice.

  20. Phosphorus and nitrogen leaching before and after tillage and urea application.

    Science.gov (United States)

    Han, Kun; Kleinman, Peter J A; Saporito, Lou S; Church, Clinton; McGrath, Joshua M; Reiter, Mark S; Tingle, Shawn C; Allen, Arthur L; Wang, L Q; Bryant, Ray B

    2015-03-01

    Leaching of nutrients through agricultural soils is a priority water quality concern on the Atlantic Coastal Plain. This study evaluated the effect of tillage and urea application on leaching of phosphorus (P) and nitrogen (N) from soils of the Delmarva Peninsula that had previously been under no-till management. Intact soil columns (30 cm wide × 50 cm deep) were irrigated for 6 wk to establish a baseline of leaching response. After 2 wk of drying, a subset of soil columns was subjected to simulated tillage (0-20 cm) in an attempt to curtail leaching of surface nutrients, especially P. Urea (145 kg N ha) was then broadcast on all soils (tilled and untilled), and the columns were irrigated for another 8 wk. Comparison of leachate recoveries representing rapid and slow flows confirmed the potential to manipulate flow fractions with tillage, albeit with mixed results across soils. Leachate trends in the finer-textured soil suggest that tillage impeded macropore flow and forced greater matrix flow. Despite significant vertical stratification of soil P that suggested tillage could prevent leaching of P via macropores from the surface to the subsoil, tillage had no significant impact on P leaching losses. Relatively high levels of soil P below 20 cm may have served as the source of P enrichment in leachate waters. However, tillage did lower losses of applied urea in leachate from two of the three soils, partially confirming the study's premise that tillage would destroy macropore pathways transmitting surface constituents to the subsoil.

  1. Ubiquitination regulates the plasma membrane expression of renal UT-A urea transporters.

    Science.gov (United States)

    Stewart, Gavin S; O'Brien, Jennifer H; Smith, Craig P

    2008-07-01

    The renal UT-A urea transporters UT-A1, UT-A2, and UT-A3 are known to play an important role in the urinary concentrating mechanism. The control of the cellular localization of UT-A transporters is therefore vital to overall renal function. In the present study, we have investigated the effect of ubiquitination on UT-A plasma membrane expression in Madin-Darby canine kidney (MDCK) cell lines expressing each of the three renal UT-A transporters. Inhibition of the ubiquitin-proteasome pathway caused an increase in basal transepithelial urea flux across MDCK-rat (r)UT-A1 and MDCK-mouse (m)UT-A2 monolayers (P UT-A transporter expression in the plasma membrane (P UT-A3 expression in the plasma membrane (P UT-A urea transporters, but that this is not the mechanism primarily used by vasopressin to produce its physiological effects.

  2. Variáveis ruminais, concentração de uréia plasmática e excreções urinárias de nitrogênio em vacas leiteiras alimentadas com concentrado processado de diferentes formas Ruminal metabolism, plasma urea concentration, and urinary excretion of nitrogen of dairy cows fed concentrate processed in different forms

    Directory of Open Access Journals (Sweden)

    Humberto Luiz Wernersbach Filho

    2006-06-01

    at 3 h post-feeding on cows fed diets contained extruded concentrate. Plasma urea did not differ across diets while for urinary excretion of nitrogen a significant difference was observed only for the diet containing the partially processed high-energy concentrate.

  3. Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil Column Method

    Directory of Open Access Journals (Sweden)

    Sulakhudin

    2010-01-01

    Full Text Available Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil ColumnMethod (Sulakhudin, A Syukur, D Shiddieq and T Yuwono: In coastal sandy soil, mainly nitrogen losses due toleaching resulted to low fertilizer efficiency. Slow-release N fertilizers are proposed to minimize these losses, andhumic-calcium coated urea has been examined. A soil column method was used to compare the effects of coated ureawith humic-calcium on transformation and leaching loss of N in coastal sandy soil. The experiment aid to compare twokinds sources of humic substances (cow manure and peat which mixed with calcium as coated urea on transformation,vertical distribution and leaching N in coastal sandy soil. The concentration of humic-calcium coated urea i.e.1%, 5%and 10% based on their weight. The results showed that urea coated with humic-calcium from cow manure (UCHMand humic-calcium from peat (UCHP increased the N total and available N in the soil and decreased leaching loss ofN from the soil column. Compared to UCHP, UCHM in all concentration showed N-nitrate higher than N-ammonium onincubation length 2, 4 and 6 weeks. The N leached from a costal sandy soil with application coated urea with UCHMranged from 21.18% to 23.72% of the total N added as fertilizer, for coated urea with UCHP they ranged between21.44% and 23.25%, whereas for urea (control reached 29.48%. Leaching losses of mineral N were lower when ureacoated with UCHM compared to urea coated with UCHP or urea fertilizer. The study concluded that the UCHM isbetter than UCHP in decreasing N leached from coastal sandy soil

  4. Fontes de lipídeos na dieta de búfalas lactantes: consumo, digestibilidade e N-uréico plasmático Effects of dietary fat sources on intake, nutrient digestibility and plasma urea nitrogen for lactating water buffaloes

    Directory of Open Access Journals (Sweden)

    Ronaldo Lopes Oliveira

    2009-03-01

    Full Text Available Os efeitos da suplementação de fontes lipídicas sobre o consumo, a digestibilidade dos nutrientes e o N-uréico plasmático foram avaliados em 12 búfalas lactantes, em três quadrados latinos simultâneos, cada um com quatro animais, quatro períodos e quatro dietas contendo uma das fontes de lípideo estudadas (sem lipídeo adicional; grão de soja; óleo de soja ou caroço de algodão. O período experimental foi de 84 dias, com quatro períodos de 21 dias, divididos em 14 dias para a adaptação e 7 para coleta. A dieta foi fornecida à vontade, duas vezes ao dia, na forma de mistura completa. Nos dias de coleta de cada período, os alimentos fornecidos e as sobras foram pesados e amostrados para análise bromatológica. Amostras de fezes foram coletadas diretamente no reto dos animais para estimativa da produção de matéria seca fecal, utilizando-se a fibra em detergente neutro indigestível como indicador, e para o cálculo de digestibilidade aparente. Os consumos de matéria seca, proteína bruta, fibra em detergente neutro e fibra em detergente ácido foram semelhantes entre as dietas. Os consumos de extrato etéreo e nutrientes digestíveis totais (NDT foram maiores para a dieta com óleo de soja. Os coeficientes de digestibilidade de matéria seca, proteína bruta e carboidratos não-fibrosos e as concentrações de N-uréico plasmático foram semelhantes entre as dietas. A utilização das fontes de lipídeos nas dietas de búfalas em lactação não influenciou o consumo e coeficiente de digestibilidade da matéria seca. Entretanto, as digestibilidades do extrato etéreo da dieta com grão de soja e das frações fibrosas da dieta com caroço de algodão foram as mais baixas.The effects of fat sources on intake, nutrient digestibility and plasma urea nitrogen were evaluated in lactating water buffalo. Twelve females were randomly distributed into four treatments: without additional lipid, soybean grain, soybean oil and

  5. Evaluation of the Effect of Split application of Urea on Nitrogen Losses in Furrow Fertigation

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    farid feizolahpour

    2017-01-01

    Full Text Available Introduction: Broadcast fertilization method increases fertilizer losses while results in lower nutrient absorption by plant roots. Fertigation is an effective method to increase water and fertilizer efficiency and to reduce the losses of nitrogen. Moreover, it allows farmers to apply the nutrients in splits and few amounts in response to crop needs. In the present study, a field experiment was conducted to investigate the effects of split application of fertilizer in furrow fertigation on nitrogen losses and corn yield. Materials and Methods: Field experiments were carried out factorially in a randomized complete block design with four replicates. Experimental treatments were consisted of three fertilizer splits (two, three, and four splits and three levels of urea fertilizer (60, 80 and 100% of required urea fertilizer, which compared with the common method (broadcasting fertilizer as used by farmers in the fields. Experiments were conducted on a one hectare field in 120 meter long and open end furrows. During the crop season, Irrigation water was applied in the same way for all fertigation treatments and the third type of the WSC flumes was used to measure the amount of input and output water in irrigation events. Moreover, for determining the indexes of uniformity of water distribution in carrying out fertigation experiments, the amount of infiltration into the soil was calculated using the Kostiakov-Louis equation. The parameters of this equation were determined using the water volume balance method. Injection of Urea fertilizer was done by using 40-liter barrels were placed at the beginning of Furrows. In this study, the injection of fertilizers was applied in the last 10 to 20 minutes of irrigation time. Results and Discussions: Results showed that water distribution uniformities of low quarter and low half in all tests were very high. Such that the water low quarter distribution uniformities for all treatments were between 90.5 to 98

  6. The effect of urea fertiliser formulations on gross nitrogen transformations in a permanent grassland soil.

    Science.gov (United States)

    Harty, Mary; Mueller, Christoph; Laughlin, Ronnie; Watson, Catherine; Richards, Karl; Lanigan, Gary; Forrestal, Patrick; McGeough, Karen

    2015-04-01

    Introduction By 2050, the current food production rate will need to increase by 70 % in order to meet the needs of the projected world population (FAO, 2014). Under the climate change response bill, Ireland has a target to reduce GHG emissions by 20% by 2020. Agriculture was responsible for almost one third of Ireland's overall Greenhouse Gas (GHG) emissions in 2012, with 39% of these emissions arising from chemical/organic fertilisers in the form of nitrous oxide (N2O). N2O losses represent environmental damage through ozone depletion and global warming as well as acidification, eutrophication, surface and groundwater contamination and it also represents financial loss to the farmer (Cameron 2013). The contradictory aims of increasing food production while reducing GHG emissions will require an adjustment to the current system of agricultural production. As part of a larger study evaluating the switching of nitrogen (N) fertiliser formulation to minimise N2O emissions, (from calcium ammonium nitrate (CAN) to urea based formulations), this experiment examined the effect of urea based fertiliser formulations on gross N transformations in a permanent pasture soil at Hillsborough, Co. Down, Northern Ireland. Study Design/Methodology A laboratory incubation study was undertaken, to examine the effect of urea in various combinations with two types of inhibitors on soil N dynamics and N2O and N2 emissions. The inhibitors examined were the urease inhibitor N-(butyl) thiophosphoric triamide (nBTPT) and the nitrification inhibitor dicyandiamide (DCD). The fertiliser products were labelled with 15N and the soil was incubated at 15 ° C at a water filled pore space of 65%. Soil mineral N (urea, NH4+, NO2- and NO3-) concentrations, gaseous losses (N2O and N2) and the 15N enrichments of NH4+, NO2-, NO3-, N2O and N2were analysed on 8 separate occasions over 25 days. An adapted numerical 15N tracing model (Müller et al., 2007) was used to quantify the effect of the inhibitors on

  7. Does Blood Urea Nitrogen Level Predict Severity and High-Risk Endoscopic Lesions in Patients with Nonvariceal Upper Gastrointestinal Bleeding?

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    Khalid Al-Naamani

    2008-01-01

    Full Text Available BACKGROUND: Nonvariceal upper gastrointestinal bleeding (UGIB is a serious medical condition requiring prompt resuscitation and early endoscopic therapy in those with high-risk endoscopic lesions (HRLs. There are little or no data correlating sole blood urea nitrogen (BUN level with the severity of nonvariceal UGIB or the presence of HRLs in the adult population.

  8. Sodium phenylbutyrate decreases plasma branched-chain amino acids in patients with urea cycle disorders.

    Science.gov (United States)

    Burrage, Lindsay C; Jain, Mahim; Gandolfo, Laura; Lee, Brendan H; Nagamani, Sandesh C S

    2014-01-01

    Sodium phenylbutyrate (NaPBA) is a commonly used medication for the treatment of patients with urea cycle disorders (UCDs). Previous reports involving small numbers of patients with UCDs have shown that NaPBA treatment can result in lower plasma levels of the branched-chain amino acids (BCAA) but this has not been studied systematically. From a large cohort of patients (n=553) with UCDs enrolled in the Longitudinal Study of Urea Cycle Disorders, a collaborative multicenter study of the Urea Cycle Disorders Consortium, we evaluated whether treatment with NaPBA leads to a decrease in plasma BCAA levels. Our analysis shows that NaPBA use independently affects the plasma BCAA levels even after accounting for multiple confounding covariates. Moreover, NaPBA use increases the risk for BCAA deficiency. This effect of NaPBA seems specific to plasma BCAA levels, as levels of other essential amino acids are not altered by its use. Our study, in an unselected population of UCD subjects, is the largest to analyze the effects of NaPBA on BCAA metabolism and potentially has significant clinical implications. Our results indicate that plasma BCAA levels should to be monitored in patients treated with NaPBA since patients taking the medication are at increased risk for BCAA deficiency. On a broader scale, these findings could open avenues to explore NaPBA as a therapy in maple syrup urine disease and other common complex disorders with dysregulation of BCAA metabolism.

  9. Forming mechanism of nitrogen doped graphene prepared by thermal solid-state reaction of graphite oxide and urea

    Energy Technology Data Exchange (ETDEWEB)

    Mou Zhigang [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Chen Xiaoye [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou 215123 (China); Du Yukou; Wang Xiaomei [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Yang Ping, E-mail: pyang@suda.edu.cn [College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123 (China); Wang Suidong, E-mail: wangsd@suda.edu.cn [Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou 215123 (China)

    2011-12-15

    Nitrogen doped graphene was synthesized from graphite oxide and urea by thermal solid-state reaction. The samples were characterized by transmission electron microscopy, atomic force microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectra, element analysis, and electrical conductivity measurement. The results reveal that there is a gradual thermal transformation of nitrogen bonding configurations from amide form nitrogen to pyrrolic, then to pyridinic, and finally to 'graphitic' nitrogen in graphene sheets with increasing annealing temperature from 200 to 700 Degree-Sign C. The products prepared at 600 Degree-Sign C and 700 Degree-Sign C show that the quantity of nitrogen incorporated into graphene lattice is {approx}10 at.% with simultaneous reduction of graphite oxide. Oxygen-containing functional groups in graphite oxide are responsible for the doping reaction to produce nitrogen doped graphene.

  10. The effect of lignite on nitrogen mobility in a low-fertility soil amended with biosolids and urea.

    Science.gov (United States)

    Paramashivam, Dharini; Clough, Tim J; Carlton, Anna; Gough, Kelsi; Dickinson, Nicholas; Horswell, Jacqui; Sherlock, Robert R; Clucas, Lynne; Robinson, Brett H

    2016-02-01

    Lignite has been proposed as a soil amendment that reduces nitrate (NO3(-)) leaching from soil. Our objective was to determine the effect of lignite on nitrogen (N) fluxes from soil amended with biosolids or urea. The effect of lignite on plant yield and elemental composition was also determined. Batch sorption and column leaching experiments were followed by a lysimeter trial where a low fertility soil was amended with biosolids (400 kg N/ha equivalent) and urea (200 kg N/ha equivalent). Treatments were replicated three times, with and without lignite addition (20 t/ha equivalent). Lignite did not reduce NO3(-) leaching from soils amended with either biosolids or urea. While lignite decreased NO3(-) leaching from an unamended soil, the magnitude of this effect was not significant in an agricultural context. Furthermore, lignite increased cumulative N2O production from soils receiving urea by 90%. Lignite lessened the beneficial growth effects of adding biosolids or urea to soil. Further work could investigate whether coating urea granules with lignite may produce meaningful environmental benefits.

  11. Spectroscopic Investigation of Nitrogen Loaded ECR Plasmas

    CERN Document Server

    Ullmann, F; Zschornack, G; Küchler, D; Ovsyannikov, V P

    1999-01-01

    Energy dispersive X-ray spectroscopy on ions in the plasma and magnetic q/A-analysis of the extracted ions were used to determine the plasmaproperties of nitrogen loaded ECR plasmas.As the beam expands from a limited plasma region and the ion extraction process alters the plasma properties in the extraction meniscus thebeam composition does not correspond to the bulk plasma composition. The analysis of measured spectra of characteristic X-rays delivers a method to determine the ion charge state distribution and the electron energy distribution inside the plasma and does not alter the plasma anddoes not depend on the extraction and transmission properties of the ion extraction and transport system. Hence this method seems to be moreaccurate than the traditional magnetic analysis and allows to analyse different plasma regions.A comparison between ion charge state distributions determined from X-ray spectra and such from q/A-analysis shows significant differencesfor the mean ion charge states in the source plasm...

  12. Studies of Wettability of Medical PVC by Remote Nitrogen Plasma

    Science.gov (United States)

    Li, Ru; Chen, Jierong

    2006-05-01

    The effects of remote nitrogen plasma and nitrogen plasma on medical PVC's surface modification are studied. The surface properties are characterized by the contact angle measurement, X-ray photoelectron spectroscopy and scanning electron microscopy. Results show that the remote nitrogen plasma treatments modify the PVC surface in both morphology and composition and the treatment by the remote nitrogen plasma in PVC surface modification is more effective than that by the nitrogen plasma. Remote nitrogen plasma can modify the surface more uniformly. After the PVC surface is treated for 2 min by remote nitrogen plasma, the [w(O)+ w(N)]/w(C)] value increases from 0.13 to 0.51 and the water contact angle decreases from 89o to 18o.

  13. Study of the effects of proline, phenylalanine, and urea foliar application to Tempranillo vineyards on grape amino acid content. Comparison with commercial nitrogen fertilisers.

    Science.gov (United States)

    Garde-Cerdán, T; López, R; Portu, J; González-Arenzana, L; López-Alfaro, I; Santamaría, P

    2014-11-15

    The aim of this work was to study the influence of foliar application of different nitrogen sources on grape amino acid content. The nitrogen sources applied to Tempranillo grapevines were proline, phenylalanine, urea, and two commercial nitrogen fertilisers, both without and with amino acids in their formulations. All treatments were applied at veraison and one week later. Proline treatment did not affect the must nitrogen composition. However, phenylalanine and urea foliar application enhanced the plants' synthesis of most of the amino acids, producing similar effects. In addition, the spray of commercial nitrogen fertilisers over leaves also induced a rise in grape amino acid concentrations regardless of the presence or absence of amino acids in their formulation. The most effective treatments were phenylalanine and urea followed by nitrogen fertilisers. This finding is of oenological interest for improved must nitrogen composition, ensuring better fermentation kinetics and most likely enhancing wine quality.

  14. Rapid Hydrophilization of Model Polyurethane/Urea (PURPEG) Polymer Scaffolds Using Oxygen Plasma Treatment

    OpenAIRE

    Rok Zaplotnik; Alenka Vesel; Gregor Primc; Xiangyu Liu; Chen, Kevin C; Chiju Wei; Kaitian Xu; Miran Mozetic

    2016-01-01

    Polyurethane/urea copolymers based on poly(ethylene glycol) (PURPEG) were exposed to weakly ionized, highly reactive low-pressure oxygen plasma to improve their sorption kinetics. The plasma was sustained with an inductively coupled radiofrequency generator operating at various power levels in either E-mode (up to the forward power of 300 W) or H-mode (above 500 W). The treatments that used H-mode caused nearly instant thermal degradation of the polymer samples. The density of the charged par...

  15. Amino substituted nitrogen heterocycle ureas as kinase insert domain containing receptor (KDR) inhibitors: Performance of structure–activity relationship approaches

    OpenAIRE

    Hayriye Yilmaz; Natalia Sizochenko; Bakhtiyor Rasulev; Andrey Toropov; Yahya Guzel; Viktor Kuz'min; Danuta Leszczynska; Jerzy Leszczynski

    2015-01-01

    A quantitative structure–activity relationship (QSAR) study was performed on a set of amino-substituted nitrogen heterocyclic urea derivatives. Two novel approaches were applied: (1) the simplified molecular input-line entry systems (SMILES) based optimal descriptors approach; and (2) the fragment-based simplex representation of molecular structure (SiRMS) approach. Comparison with the classic scheme of building up the model and balance of correlation (BC) for optimal descriptors approach sho...

  16. 奶牛乳尿素氮的研究进展%Research Overview of Milk Urea Nitrogen

    Institute of Scientific and Technical Information of China (English)

    杨露; 熊本海

    2012-01-01

    Milk urea nitrogen (MUN) is the concentration of urea nitrogen in milk which is an major indicator meaning efficiency of utilization of dietary crude protein . Thus measuring and using MUN is a way to evaluate whether the diet formulation is suitable or not and whether the feeding program is reasonable or not. This paper reviewed the generation mechanism of MUN, the monitoring methods and its affected factors. It also analysed some current problems and predicted its future development. In a word, it is quite useful for the application of MUN to predict ruminant nutrient requirements and scientific diet formulation.%乳尿素氮(milk urea nitrogen,MUN)是指牛奶中尿素氮的浓度,是评定日粮蛋白质利用率的一个重要指标.测定和使用MUN能够判断日粮配方是否合理,管理计划是否恰当.作者综述了MUN的产生机制、监测方法及其影响因素,分析了目前应用该指标存在的问题,并预测了未来发展的趋势.总之,它的应用对动态预测反刍动物营养需要、科学配制日粮具有重要意义.

  17. ASSOCIATIVE EFFECT OF MOLASSES-UREA BLOCK AND FORAGE QUALITY ON NUTRIENT DIGESTION AND NITROGEN RETENTION IN SHEEP

    Directory of Open Access Journals (Sweden)

    lqbal Saeed. M. M. Siddiqui and G. I. Habib

    2002-01-01

    Full Text Available A study was conducted in a 4x4 Latin square design involving four adult crossbred (Kaghani x Rambouillet weather kept in individual metabolic crates and four experimental diets viz: maize stovers (Diet A, maize stovers with 150 g/d molasses-urea block (Diet B, lucerne hay (Diet Cand lucerne hay with 150 g/d molasses-urea block (Diet D. The forage intake was restricted to 2% of body weight. Each experimental period consisted 10 days of adaptation followed by five days of data collection. Total dry matter intake on molasses-urea block (MUB supplemented diets was higher (p<0.05 than unsupplemented diets. The daily quantity of total dry matter and water consumed by weathers was higher (p < 0.001 on MUB supplemented diets. Water consumption was positively co-related to nitrogen intake (r2 0.66: p< 0.00 I and varied due to diets (p < 0.00 I. in vivo dry matter digestibility (DMD and organic matter digestibility (OMD of lucerne hay-based diets were greater (P< 005 than those containing maize stovers. Supplementation of MUB did not affect the DMD or OMD of the diets. The interaction of MUB and forage (P = 0.06 revealed that MUB was effective in increasing (P< 0.05 the nitrogen digestibility of maize stovers from 30,59% on diet A to 51.33% on diet B but did not affect the nitrogen digestibility in animals fed lucerne hay. The wethers receiving lucerne hay-based diets retained more nitrogen (p< 0.001 than those given maize stovers (8.50 's 3,12 g/d. Molasses-urea block supplementation on both forages increased (p < 0.05 the nitrogen retention. Mean nitrogen retention was I 82. 4.41, 7 .19 and 9.82 gld in wethers receiving diets A. B. C and D. respectively. Mean rumen ammonia concentration (mg N/lOO ml in wethers receiving maize stovers. was 10.52. which increased (p< 0,05 to 17.87 in response to MUB supplementation. On lucerne hay. the rumen ammonia concentrations did not change due to MUB and the mean values on diets C and D were 24,24 and 29.88 mg N/100

  18. f-Ratios calculated with and without urea uptake in nitrogen uptake by phytoplankton

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Corre, P.L.; L'Helguen, S.

    nitrate. Qualitatively this is recognized: “the f ratio derived from nitrate and ammonium uptake alone would overestimate the true ratio of new/total production” (Harrison et al., 1987); “non-inclusion of urea uptake overesti- mates thef-ratio” (Probyn... of Plankton Research. 5,657-676. Hansel1 C. A. and J. J. Gocring (19X9) A method for estimating uptake and production rates for urea in scawatcr using “N urea and lJC urea. Cunadian Journal of Fisheries und Aquatic Science, 46, 198-202. Harrison W. G., E. J...

  19. Nitrogen excretion and expression of urea cycle enzymes in the atlantic cod (Gadus morhua l.): a comparison of early life stages with adults

    Science.gov (United States)

    Chadwick; Wright

    1999-10-01

    For many years, the urea cycle was considered to be relatively unimportant in the life history of most teleost fishes. In previous studies, we were surprised to find that newly hatched freshwater rainbow trout embryos had relatively high activities of the key urea cycle enzyme, carbamoyl phosphate synthetase III (CPSase III), and other enzymes in the pathway, whereas adult trout had much lower or non-detectable activities. The present study tested the hypothesis that urea cycle enzyme expression is unique to early stages of rainbow trout. In marine Atlantic cod (Gadus morhua) embryos, CPSase III, ornithine transcarbamoylase (OTCase), glutamine synthetase (GSase) and arginase activities were all expressed prior to hatching. Urea excretion was detected shortly after fertilization and rates were high relative to those of ammonia excretion (50-100 % of total nitrogen excreted as urea nitrogen; total=ammonia+urea). Urea concentration was relatively constant in embryos, but ammonia concentration increased by about fourfold during embryogenesis. Two populations of cod embryos were studied (from Newfoundland and New Brunswick), and significant differences in enzyme activities and excretion rates were detected between the two populations. In adult cod, CPSase III was not detectable in liver, white muscle, intestine and kidney tissues, but OTCase, GSase and arginase were present. Adult cod excreted about 17 % of nitrogenous waste as urea. Taken together, these data indicate that early urea cycle enzyme expression is not unique to rainbow trout but is also a feature of Atlantic cod development, and possibly other teleosts. The relatively high urea excretion rates underline the importance of urea as the primary nitrogen excretory product in Atlantic cod during early embryogenesis.

  20. Effects of Rice Straw Supplemented with Urea and Molasses on Intermediary Metabolism of Plasma Glucose and Leucine in Sheep

    Science.gov (United States)

    Alam, Mohammad Khairul; Ogata, Yasumichi; Sato, Yukari; Sano, Hiroaki

    2016-01-01

    An isotope dilution method using [U-13C]glucose and [1-13C]leucine (Leu) was conducted to evaluate the effects of rice straw supplemented with urea and molasses (RSUM-diet) on plasma glucose and Leu turnover rates in sheep. Nitrogen (N) balance, rumen fermentation characteristics and blood metabolite concentrations were also determined. Four sheep were fed either mixed hay (MH-diet), or a RSUM-diet with a crossover design for two 21 days period. Feed allowance was computed on the basis of metabolizable energy at maintenance level. The isotope dilution method was performed as the primed-continuous infusion on day 21 of each dietary period. Nitrogen intake was lower (p = 0.01) for the RSUM-diet and N digestibility did not differ (p = 0.57) between diets. Concentrations of rumen total volatile fatty acids tended to be higher (p = 0.09) for the RSUM-diet than the MH-diet. Acetate concentration in the rumen did not differ (p = 0.38) between diets, whereas propionate concentration was higher (p = 0.01) for the RSUM-diet compared to the MH-diet. Turnover rates as well as concentrations of plasma glucose and Leu did not differ between diets. It can be concluded that kinetics of plasma glucose and Leu metabolism were comparable between the RSUM-diet and the MH-diet, and rumen fermentation characteristics were improved in sheep fed the RSUM-diet compared to the MH-diet. PMID:26949953

  1. Effects of Nitrification Inhibitors and Sulphur Coated Urea(SCU on Different Nitrogen Sources and Wheat Yield

    Directory of Open Access Journals (Sweden)

    LI Yong-qiang

    2016-05-01

    Full Text Available Nitrogen is essential for plant growth and health, and it is also a limiting factor for the growth in most agricultural systems. Intensive N fertilizer application has become the traditional habit for agricultural producers in China because of its importance to plant productivity and agricultural land profitability. But some problems have appeared with the increase of the amount of nitrogen fertilizer applied, urea used in crops is easy to lose from volatilization or leaching. Therefore, current crop management practices lead to a highly nitrifying soil environments. Nitrogen emission is the main source of soil acidity and environmental pollution. Several methods for the use of slow controlled release urea have been reported to be used to control the pollution and to enhance nitrogen use efficiency. There is a growing interest in the formulations of coated chemical fertilizers with both urease inhibitor and nitrification inhibitor. Urease inhibitor and nitrification inhibitor may improve urea N-use efficiency and minimize N losses by gaseous emissions of ammonia(NH3 to the atmosphere and nitrate(NO3- leaching into the surface and ground water. Dicyandiamide(DCD is a nitrification inhibitor that has been studied for many years, it can effectively inhibit nitrification and N2O emission in many agricultural ecosystems. However, limited information is available on the use of the combination of nitrification inhibitor and urease inhibitor applied with urea fertilizer, especially for thiourea(THU and thiourea formaldehyde resin(TFR applications. Therefore the purpose of this study is to investigate the effect of urea with different inhibitors to improve the efficiency of nitrogen utilization. A field pot experiment was conducted to explore how to increase the concentration of DCD/THU/TFR/sulfur-coated urea(SCU to affect the transformation of soil nitrogen and wheat yield. The experiment was designed for twelve treatments which included no nitrogen

  2. Effects of nitrogen supply on inter-organ fluxes of urea-N and renal urea-N kinetics in lactating Holstein cows

    DEFF Research Database (Denmark)

    Røjen, Betina Amdisen; Theil, Peter Kappel; Kristensen, Niels Bastian

    2011-01-01

    The effects of decreasing ruminal urea infusion in lactating dairy cows fed a basal diet deficient in rumen degradable protein on inter-organ urea-N fluxes, epithelial urea-N extraction, and renal urea-N kinetics were investigated. Eight Danish Holstein cows fitted with a ruminal cannula...... and permanent indwelling catheters in the major splanchnic blood vessels and the gastrosplenic vein were used. The cows were randomly allocated to a triplicate incomplete 3 × 3 Latin square design with 14-d periods. Treatments were continuous ventral ruminal infusion of water, 4.1 g of feed urea/kg of dry...... matter intake, and 8.5 g of feed urea/kg of dry matter intake. Dry matter intake and milk yield decreased linearly with decreasing urea infusion. Arterial blood urea-N and ruminal ammonia concentrations decreased linearly with decreasing urea infusion. In absolute amounts, the urea-N recycling did...

  3. Urea as nitrogen source for phytoplankton production in coastal waters of Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.

    Annual variation of urea in coastal waters off Goa, India is 0 to 2.92 mu g-at N.1/1 and 0 to 4.69 mu g-at N.1/1 in adjacent estuarine waters of Mandovi. Peaks of phytoplankton production accompanied with the decrease in urea in June and October...

  4. ACUTE RENAL FAILURE WITH NORMAL PLASMA UREA LEVEL SECONDARY TO ACUTE PYELONEPHITIS IN A SINGLE KIDNEY PATIENT

    Directory of Open Access Journals (Sweden)

    Algranati L

    2007-04-01

    Full Text Available SUMMARY: Acute renal failure is a syndrome that usually runs with an increase in creatinine and urea plasma levels. However, there are clinical situations in which this syndrome may run with an increase in plasma creatinine keeping normal the urea one. In this report we present a case of acute renal failure with normal plasma urea level secondary to an acute pyelonephritis in a single kidney patient. The patient had an increased fractional excretion of urea which could explain the normal plasma urea levels found despite of his reduced glomerular filtration. This increased urea excretion state was interpreted as a consequence of the nephrogenic diabetes insipidus and alteration of the intra-renal urea reciclying process that the acute pyelonephritis induced. In conclusion: Acute pyelonephritis in a single kidney patient can appear as a pattern of acute renal failure with normal plasma urea levels.RESUMEN: La insuficiencia renal aguda es un sindrome que característicamente cursa con niveles plasmáticos elevados de urea y creatinina. Sin embargo, hay situaciones clínicas en las cuales este sindrome puede cursar con un incremento de la creatininemia sin presentar elevación de la uremia. En este reporte presentamos un caso clínico de una insuficiencia renal aguda con uremia normal secundaria a una pielonefritis aguda en un paciente con riñón único. El paciente presentaba una elevada excreción fraccional de urea lo cual podía explicar su uremia normal pese a estar cursando una caída del filtrado gomerular. Dicha excreción de urea elevada fue interpretada como secundaria a una diabetes insipida nefrogénica y una alteración en el recirculado intra-renal de la urea ambos producto de la pielonefritis aguda. Concluimos que la pielonefritis aguda en un paciente mono-reno puede presentarse con un patrón de insuficiencia renal aguda con uremia normal.

  5. ACUTE RENAL FAILURE WITH NORMAL PLASMA UREA LEVEL SECONDARY TO ACUTE PYELONEPHITIS IN A SINGLE KIDNEY PATIENT

    Directory of Open Access Journals (Sweden)

    Imperiali N

    2006-03-01

    Full Text Available SUMMARYAcute renal failure is a syndrome that usually runs with an increase in creatinine and urea plasma levels. However, there are clinical situations in which this syndrome may run with an increase in plasma creatinine keeping normal the urea one.In this report we present a case of acute renal failure with normal plasma urea level secondary to an acute pyelonephritis in a single kidney patient. The patient had an increased fractional excretion of urea which could explain the normal plasma urea levels found despite of his reduced glomerular filtration. This increased urea excretion state was interpreted as a consequence of the nephrogenic diabetes insipidus and alteration of the intra-renal urea reciclying process that the acute pyelonephritis induced. In conclusion: Acute pyelonephritis in a single kidney patient can appear as a pattern of acute renal failure with normal plasma urea levels. RESUMEN:La insuficiencia renal aguda es un sindrome que característicamente cursa con niveles plasmáticos elevados de urea y creatinina. Sin embargo, hay situaciones clínicas en las cuales este sindrome puede cursar con un incremento de la creatininemia sin presentar elevación de la uremia.En este reporte presentamos un caso clínico de una insuficiencia renal aguda con uremia normal secundaria a una pielonefritis aguda en un paciente con riñón único. El paciente presentaba una elevada excreción fraccional de urea lo cual podía explicar su uremia normal pese a estar cursando una caída del filtrado gomerular. Dicha excreción de urea elevada fue interpretada como secundaria a una diabetes insipida nefrogénica y una alteración en el recirculado intra-renal de la urea ambos producto de la pielonefritis aguda. Concluimos que la pielonefritis aguda en un paciente mono-reno puede presentarse con un patrón de insuficiencia renal aguda con uremia normal.

  6. The association between milk urea nitrogen and DHI production variables in western commercial dairy herds.

    Science.gov (United States)

    Johnson, R G; Young, A J

    2003-09-01

    A retrospective observational study was conducted using data from Dairy Herd Improvement monthly tests to investigate the association between milk urea nitrogen (MUN) concentration and milk yield, milk protein, milk fat percentage, SCC, and parity for commercial Holstein and Jersey herds in Utah, Idaho, and Montana. Mean MUN for Holstein cows was 15.5 mg/ dl (5.5 mmol/L) MUN and 14.1 mg/dl (5.0 mmol/L) for Jersey cows. Mean MUN, categorized by 30-d increments of days in milk (DIM), paralleled changes in milk values and followed a curvilinear shape. For Holstein cows, concentrations of MUN were different among lactation groups 1, 2, and 3+ for the first 90 DIM for Holsteins. Overall, concentrations of MUN were lower during for the first 30 DIM compared with all other DIM categories for both Holstein and Jersey cows. Multivariate regression models of MUN by milk protein showed that as the milk protein percentage increased, MUN concentration decreased; however, models for Jersey cows showed that MUN did not decrease significantly until above 3.4% milk protein. Milk fat percentage also decreased as MUN increased, but by only 1 mg/dl MUN over the range of 2.2 to 5.8% milk fat. Somatic cell count showed a negative relationship with MUN. Holstein cows with milk protein percentage >3.2% had lower MUN compared with cows having milk protein <3.2% for milk yields from 27.3 to 54.5 kg/d and lower than cows having a milk protein <3.0% for milk yield of 54.5 to 63.6 kg/d. In Jersey cows, MUN concentrations were not different among milk protein percentage categorized by milk yield. This study found that MUN was inversely associated with milk protein percentage and paralleled change in milk yield over time.

  7. A practical approach for assessing the efficiency of coated urea on controlling nitrogen availability

    Directory of Open Access Journals (Sweden)

    Geisa Lima Mesquita

    Full Text Available ABSTRACT We propose an approach for assessing the efficiency of coating materials on controlling nitrogen (N availability to plants. It is based on the use of coated and soluble urea (UR applied to corn over 3 growing cycles, as follows: coated UR with longevity of 2 (UR-2m or 4 months (UR-4m with application of 900 mg N∙pot−1 at the beginning of the experiment, soluble UR with a split application of 900 mg N∙pot−1 (300 mg N∙pot−1 per growing cycle, UR-3x, soluble UR with a sole application of 900 mg N∙pot−1 at the beginning of the experiment (UR-1x, and a control treatment. At the end of each growing cycle, shoots were harvested to estimate N provision by the UR by quantifying dry matter (DM and N uptake. In the first cycle, UR-2m and UR-4m promoted lower plant growth and N accumulation in shoots than UR-1x. However, in the third cycle, higher shoot N uptake and DM production was recorded in UR-4m than in UR-1x. Furthermore, fertilizer contribution for shoot N uptake in UR-4m plants was higher than those in UR-1x and UR-2m at the end of the experiment. Accordingly, consecutive growing cycles combined with forms of soluble UR application were able to characterize the pattern of N release from coated fertilizers, being, thus, a suitable method to evaluate the efficiency of such products. We argue that our practical approach could be used by the industry in fertilizer quality programs and to register fertilizer coating materials by regulatory agencies.

  8. Study on Membrane Microstructures and Characteristics of Infrared Spectra and Nitrogen Release of Solid-Liquid Reaction Coated Urea

    Institute of Scientific and Technical Information of China (English)

    MAO Xiao-yun; FENG Xin; WANG De-han; SUN Ke-jun; LIAO Zong-wen

    2004-01-01

    The membrane microstructures and the mechanism of two coated ureas formed through solidliquid reaction were observed by scanning electron microscope and infrared spectra, the relation of the structural characteristics with the nitrogen release feature was also discussed by combining with nitrogen dissolution in water. The results showed that the membranes were made of solid particles tightly connected to each other and were piled up layer by layer through liquid glue. Porosity and aperture of membrane were determined by compactness of piled layers and the particles in a single layer and also related to the characteristics of coating materials. Research of the infrared spectra of membrane, made of a solid powder and a liquid glue, proved that O-H on the solid surface was bonded with the double bond of the liquid glue, thus forming membrane and keeping it stable. It was found that the two coated ureas showed obvious differences in nitrogen releasing due to their membrane structures, the porosity and aperture of membrane were the critical factors for nitrogen releasing.

  9. [Effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and quality and fertilizer nitrogen use efficiency].

    Science.gov (United States)

    Ma, Fu-Liang; Song, Fu-Peng; Gao, Yang; Zou, Peng

    2012-01-01

    A field experiment was conducted to study the effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and its quality, plow layer soil inorganic nitrogen (N) contents, and fertilizer N use efficiency. Compared with traditional urea fertilizer, both sulfur- and polymer-coated controlled release urea fertilizers increased the grain yield by 10.4%-16.5%, and the grain protein and starch contents by 5.8%-18.9% and 0.3%-1.4%, respectively. The controlled release urea fertilizers could maintain the topsoil inorganic N contents to meet the N requirement for the wheat, especially during its late growth stage. In the meantime, the fertilizer N use efficiency was improved by 58.2%-101.2%. Polymer-coated urea produced better wheat yield and higher fertilizer N use efficiency, compared with sulfur-coated controlled release urea.

  10. Amino substituted nitrogen heterocycle ureas as kinase insert domain containing receptor (KDR inhibitors: Performance of structure–activity relationship approaches

    Directory of Open Access Journals (Sweden)

    Hayriye Yilmaz

    2015-06-01

    Full Text Available A quantitative structure–activity relationship (QSAR study was performed on a set of amino-substituted nitrogen heterocyclic urea derivatives. Two novel approaches were applied: (1 the simplified molecular input-line entry systems (SMILES based optimal descriptors approach; and (2 the fragment-based simplex representation of molecular structure (SiRMS approach. Comparison with the classic scheme of building up the model and balance of correlation (BC for optimal descriptors approach shows that the BC scheme provides more robust predictions than the classic scheme for the considered pIC50 of the heterocyclic urea derivatives. Comparison of the SMILES-based optimal descriptors and SiRMS approaches has confirmed good performance of both techniques in prediction of kinase insert domain containing receptor (KDR inhibitory activity, expressed as a logarithm of inhibitory concentration (pIC50 of studied compounds.

  11. Efficacy of Dietary Urea-Impregnated Zeolite in Improving Rumen Fermentation Characteristics of Local Lamb

    Directory of Open Access Journals (Sweden)

    D. Kardaya

    2012-12-01

    Full Text Available A research on dietary inclusion of urea-impregnated zeolite as slow-release urea (SRU agent had been conducted to reveal its effect on ruminal fermentation characteristics in local lambs. The research used 24 heads of 7-8 mo old of local male lambs with (20.12±2.1 kg BW designed upon a randomized block design. Treatments consisted of diets contained no urea, urea, zeolite, and urea-impregnated zeolite. The collected data was analyzed with UNIANOVA and Duncan’s multiple-range test. Results indicated that feeding no urea, zeolite, or urea-impregnated zeolite ration produced lower ruminal ammonia nitrogen than feeding urea ration (P<0.05. Feeding zeolite ration produced lower ruminal pH than feeding urea ration (P<0.05. Despite total VFAs were similar across the treatments, feeding urea-impregnated zeolite ration produced lower ruminal acetate, acetate to propionate ratio, or methane production than feeding urea ration (P<0.05. Feeding urea ration produced the lowest molar proportion of branch-chained VFAs (P<0.05. Feeding urea ration produced higher plasma urea concentration than feeding no urea ration (2.75 mM vs. 2.16 mM; P<0.05. In conclusion, zeolite or urea-impregnated zeolite as slow-release ammonia or SRU agent was potential in decreasing ruminal ammonia, pH, acetate to propionate ratio, methane, and maintaining low plasma urea within its physiological range.

  12. Polymer Coated Urea in Turfgrass Maintains Vigor and Mitigates Nitrogen's Environmental Impacts

    OpenAIRE

    LeMonte, Joshua J.; Jolley, Von D.; Summerhays, Jeffrey S.; Richard E Terry; Hopkins, Bryan G.

    2016-01-01

    Polymer coated urea (PCU) is a N fertilizer which, when added to moist soil, uses temperature-controlled diffusion to regulate N release in matching plant demand and mitigate environmental losses. Uncoated urea and PCU were compared for their effects on gaseous (N2O and NH3) and aqueous (NO3(-)) N environmental losses in cool season turfgrass over the entire PCU N-release period. Field studies were conducted on established turfgrass sites with mixtures of Kentucky bluegrass (Poa pratensis L.)...

  13. Polymer Coated Urea in Turfgrass Maintains Vigor and Mitigates Nitrogen's Environmental Impacts

    Science.gov (United States)

    LeMonte, Joshua J.; Jolley, Von D.; Summerhays, Jeffrey S.; Terry, Richard E.; Hopkins, Bryan G.

    2016-01-01

    Polymer coated urea (PCU) is a N fertilizer which, when added to moist soil, uses temperature-controlled diffusion to regulate N release in matching plant demand and mitigate environmental losses. Uncoated urea and PCU were compared for their effects on gaseous (N2O and NH3) and aqueous (NO3-) N environmental losses in cool season turfgrass over the entire PCU N-release period. Field studies were conducted on established turfgrass sites with mixtures of Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.) in sand and loam soils. Each study compared 0 kg N ha-1 (control) to 200 kg N ha-1 applied as either urea or PCU (Duration 45CR®). Application of urea resulted in 127–476% more evolution of measured N2O into the atmosphere, whereas PCU was similar to background emission levels from the control. Compared to urea, PCU reduced NH3 emissions by 41–49% and N2O emissions by 45–73%, while improving growth and verdure compared to the control. Differences in leachate NO3- among urea, PCU and control were inconclusive. This improvement in N management to ameliorate atmospheric losses of N using PCU will contribute to conserving natural resources and mitigating environmental impacts of N fertilization in turfgrass. PMID:26764908

  14. Polymer Coated Urea in Turfgrass Maintains Vigor and Mitigates Nitrogen's Environmental Impacts.

    Directory of Open Access Journals (Sweden)

    Joshua J LeMonte

    Full Text Available Polymer coated urea (PCU is a N fertilizer which, when added to moist soil, uses temperature-controlled diffusion to regulate N release in matching plant demand and mitigate environmental losses. Uncoated urea and PCU were compared for their effects on gaseous (N2O and NH3 and aqueous (NO3(- N environmental losses in cool season turfgrass over the entire PCU N-release period. Field studies were conducted on established turfgrass sites with mixtures of Kentucky bluegrass (Poa pratensis L. and perennial ryegrass (Lolium perenne L. in sand and loam soils. Each study compared 0 kg N ha(-1 (control to 200 kg N ha(-1 applied as either urea or PCU (Duration 45CR®. Application of urea resulted in 127-476% more evolution of measured N2O into the atmosphere, whereas PCU was similar to background emission levels from the control. Compared to urea, PCU reduced NH3 emissions by 41-49% and N2O emissions by 45-73%, while improving growth and verdure compared to the control. Differences in leachate NO3(- among urea, PCU and control were inconclusive. This improvement in N management to ameliorate atmospheric losses of N using PCU will contribute to conserving natural resources and mitigating environmental impacts of N fertilization in turfgrass.

  15. DETERMINATION OF PLASMA LEVELS OF UREA AND CREATININE IN PANTANAL HORSES POCONÉ REGION - MT

    Directory of Open Access Journals (Sweden)

    M. R. Guazina

    2016-09-01

    Full Text Available This study aimed to determine the plasma levels of urea and creatinine, besides evaluating the influence of sex and age factors on these substances in Pantaneiros horses, animals of high economic and social importance in the Pantanal. In Poconé-MT region, 80 animals were used, which were divided into four groups: Group 1: male foals (n= 20, aged 8 months and 2 years, Group 2: female foals (n= 20, aged 8 months and 2 years, Group 3: adult males (n= 20, aged from 3 years, Group 4: adult females (n= 20, aged from 3 years. All animals were classified as healthy after clinical examinations, as well as serum negativity for Equine Infectious Anemia (EIA. Blood samples for subsequent laboratory analysis were taken from the jugular vein. The mean values of urea and creatinine found for Pantaneiros horses were similar to other breeds of horses and did not vary influenced by the sexual factor, however plasma levels of creatinine increased with the age

  16. Effects of Dietary Standardized Ileal Digestible Valine Level on Growth Performance, Plasma Amino Acid and Urea Nitrogen Contents of Finishing Pigs%饲粮标准回肠可消化缬氨酸水平对育肥猪生长性能、血浆氨基酸和尿素氮含量的影响

    Institute of Scientific and Technical Information of China (English)

    易孟霞; 易学武; 贺喜; 陈达图; 胡官波; 张石蕊

    2015-01-01

    通过2个试验探讨饲粮中标准回肠可消化缬氨酸( SID Val)水平对育肥猪生长性能、血浆氨基酸和尿素氮含量的影响. 试验 1、试验 2 分别选用 360 头初始体重为( 53. 75 ± 2.63) kg、(83.67±2.92) kg的杜×长×大三元杂交育肥猪,按体重相近、遗传基础相似的原则,随机分为5个处理,每个处理6个重复,每个重复12头猪. 同一试验中,各处理的饲粮除缬氨酸外,其余营养水平均参照NRC(2012)推荐标准设计. 试验1中各处理试验饲粮的SID Val水平分别为0.50%、0.55%、0.60%、0.65%和0.70%,试验期为50~80 kg阶段;试验2中各处理试验饲粮的SID Val水平分别为0.43%、0.48%、0.53%、0.58%和0.63%,试验期为80~120 kg阶段.结果表明:试验1中饲粮SID Val水平为0.65%和0.70%的处理的平均日增重和料重比差异不显著( P>0.05) ,但较饲粮SID Val水平为0.50%的处理得到显著改善( P0.05) ,但显著高于饲粮SID Val水平为0.43%的处理( P0.05). 采用折线模型和二次曲线回归模型,综合平均日增重和料重比得出,育肥猪50~80 kg、80~120 kg阶段饲粮标准回肠可消化赖氨酸水平分别为0.85%、0.70%时,其SID Val需要量范围值分别为0.61%~0.66%、0.52%~0.56%,最佳需要量分别为0.65%和0.53%.%Two experiments were conducted to investigate the effects of dietary standardized ileal digestible ( SID) valine ( Val) level on growth performance, plasma amino acid and urea nitrogen contents of finishing pigs. Each experiment contained 360 barrows ( Duroc×Landrace×Yorkshire) which were allotted to five treat-ments with six replicates per treatment and 12 pigs per replicate according to the similar body weight and genet-ic foundation. Average initial body weight of pigs in experiment 1 was (53.75±2.63) kg and in experiment 2 was (83.67±2.92) kg. In the same experiment, except dietary Val, the nutrient levels of experimental diets were referred to recommend the nutrient requirements of swine in

  17. Ammonia Volatilization and Nitrogen Utilization Efficiency in Response to Urea Application in Rice Fields of the Taihu Lake Region, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ammonia volatilization losses, nitrogen utilization efficiency, and rice yields in response to urea application to a rice field were investigated in Wangzhuang Town, Changshu City, Jiangsu Province, China. The N fertilizer treatments, applied in triplicate, were 0 (control), 100, 200, 300, or 350 kg N ha-1. After urea was applied to the surface water, a continuous airflow enclosure method was used to measure ammonia volatilization in the paddy field. Total N losses through ammonia volatilization generally increased with the N application rate, and the two higher N application rates (300 and 350 kg N ha-1) showed a higher ratio of N lost through ammonia volatilization to applied N. Total ammonia loss by ammonia volatilization during the entire rice growth stage ranged from 9.0% to 16.7% of the applied N. Increasing the application rate generally decreased the ratio of N in the seed to N in the plant. For all N treatments, the nitrogen fertilizer utilization efficiency ranged from 30.9% to 45.9%. Surplus N with the highest N rate resulted in lodging of rice plants, a decreased rate of nitrogen fertilizer utilization, and reduced rice yields. Calculated from this experiment, the most economical N fertilizer application rate was 227 kg ha-1 for the type of paddy soil in the Taihu Lake region. However, recommending an appropriate N fertilizer application rate such that the plant growth is enhanced and ammonia loss is reduced could improve the N utilization efficiency of rice.

  18. Effect of delayed wrapping and wrapping source on nitrogen balance and blood urea nitrogen in gestating sheep offered alfalfa silage

    Science.gov (United States)

    Exposing ensiled forage to oxygen can result in DM deterioration and reduce silage intake by animals. This study was conducted to investigate the effects of 2 different wrapping sources and time intervals between baling and wrapping on N balance and blood urea N in gestating sheep offered alfalfa si...

  19. Rapid Hydrophilization of Model Polyurethane/Urea (PURPEG Polymer Scaffolds Using Oxygen Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Rok Zaplotnik

    2016-04-01

    Full Text Available Polyurethane/urea copolymers based on poly(ethylene glycol (PURPEG were exposed to weakly ionized, highly reactive low-pressure oxygen plasma to improve their sorption kinetics. The plasma was sustained with an inductively coupled radiofrequency generator operating at various power levels in either E-mode (up to the forward power of 300 W or H-mode (above 500 W. The treatments that used H-mode caused nearly instant thermal degradation of the polymer samples. The density of the charged particles in E-mode was on the order of 1016 m−3, which prevented material destruction upon plasma treatment, but the density of neutral O-atoms in the ground state was on the order of 1021 m−3. The evolution of plasma characteristics during sample treatment in E-mode was determined by optical emission spectroscopy; surface modifications were determined by water adsorption kinetics and X-ray photoelectron spectroscopy; and etching intensity was determined by residual gas analysis. The results showed moderate surface functionalization with hydroxyl and carboxyl/ester groups, weak etching at a rate of several nm/s, rather slow activation down to a water contact angle of 30° and an ability to rapidly absorb water.

  20. The influence of casein and urea as nitrogen sources on in vitro equine caecal fermentation

    NARCIS (Netherlands)

    Santos, A.S.; Ferreira, L.M.M.; Martin-Rosset, W.; Cotovio, M.; Silva, F.; Bennett, R.N.; Cone, J.W.; Bessa, R.J.B.; Rodrigues, M.A.M.

    2012-01-01

    To access the fermentative response of equine caecal microbial population to nitrogen availability, an in vitro study was conducted using caecal contents provided with adequate energy sources and nitrogen as limiting nutrient. Two nitrogen (N) sources were provided, protein (casein) and non-protein

  1. Oligosaccharide and creatine supplementation on glucose and urea nitrogen in blood and serum creatine kinase in basketball athletes.

    Science.gov (United States)

    Shi, Daling

    2005-01-01

    The effects of oligosaccharide and creatine (Cr) supplementation on glucose, lactic acid and urea nitrogen levels in blood and activity of serum creatine kinase (CK) were explored. Twenty CUBA male athletes were divided into 4 groups: group A (supplementation of Cr alone), group B (supplementation of oligosaccharide), group C (supplementation of oligosaccharide and Cr) and group D (placebo control group). By using orthogonal L4 table (2(3)), the experiment was performed. There were factors including oligosaccharide (carbohydrate, CHO), Cr and their correlation. Each factor had two levels: supplementation and no-supplementation. The results showed that the supplementation of CHO or Cr alone, combined supplementation of CHO and Cr could significantly reduce the glucose, urea nitrogen levels in blood and serum CK activity after competition in the athletes. Moreover, the effects of combined supplementation of CHO and Cr were more satisfactory. It was concluded that supplementation of CHO and Cr could promote the recovery of physical performance and athletic abilities after athletics in basketball athletes.

  2. Oligosaccharide and Creatine Supplementation on Glucose and Urea Nitrogen in Blood and Serum Creatine Kinase in Basketball Athletes

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The effects of oligosaccharide and creatine (Cr) supplementation on glucose, lactic acid and urea nitrogen levels in blood and activity of serum creatine kinase (CK) were explored. Twenty CUBA male athletes were divided into 4 groups: group A (supplementation of Cr alone), group B (supplementation of oligosaccharide), group C (supplementation of oligosaccharide and Cr) and group D (placebo control group). By using orthogonal L4 table (23), the experiment was performed. There were factors including oligosaccharide (carbohydrate, CHO), Cr and their correlation. Each factor had two levels: supplementation and no-supplementation. The results showed that the supplementation of CHO or Cr alone, combined supplementation of CHO and Cr could significantly reduce the glucose, urea nitrogen levels in blood and serum CK activity after competition in the athletes. Moreover, the effects of combined supplementation of CHO and Cr were more satisfactory. It was concluded that supplementation of CHO and Cr could promote the recovery of physical performance and athletic abilities after athletics in basketball athletes.

  3. Effect of increased systemic concentrations of urea nitrogen in crossbred heifers on in vitro fertilization (IVF)

    Science.gov (United States)

    Elevated levels of dietary N and hence systemic concentrations of urea-N have been shown to have a deleterious effect on reproductive processes. The objective of this study was to determine the effect of feeding pubertal crossbred heifers diets with moderate (M-N; 64.8% corn silage, 30.0% alfalfa h...

  4. Application of Urea Nitrogen Detection on Dairy Cattle Farm%尿素氮检测在规模化奶牛场中的应用

    Institute of Scientific and Technical Information of China (English)

    马广英; 高树; 徐清华; 赵新伟; 张文举

    2013-01-01

    尿素氮检测作为一种简便易行且对奶牛非侵害的技术手段越来越受到规模化牧场的重视,本文从尿素氮产生的机理、影响尿素氮浓度的因素、尿素氮的检测以及在生产中的应用展开论述,以供广大同行参考.%Urea nitrogen detection as a simple and noinvasive technology means which has been popularized on dairy cattle factory.To provide for our counterparts,this paper collected literature and the content included the mechanism of producing from urea nitrogen,factors of affecting urea nitrogen concentration and apply on dairy cattle factory.

  5. Reverse osmosis membrane of high urea rejection properties. [water purification

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T. J. (Inventor)

    1980-01-01

    Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source. A polymeric membrane is formed by depositing a polymer of the unsaturated monomer from the plasma onto a substrate, so that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.

  6. Application of Response Surface Methodology for Optimization of Urea Grafted Multiwalled Carbon Nanotubes in Enhancing Nitrogen Use Efficiency and Nitrogen Uptake by Paddy Plants

    Directory of Open Access Journals (Sweden)

    Norazlina Mohamad Yatim

    2016-01-01

    Full Text Available Efficient use of urea fertilizer (UF as important nitrogen (N source in the world’s rice production has been a concern. Carbon-based materials developed to improve UF performance still represent a great challenge to be formulated for plant nutrition. Advanced N nanocarrier is developed based on functionalized multiwall carbon nanotubes (f-MWCNTs grafted with UF to produce urea-multiwall carbon nanotubes (UF-MWCNTs for enhancing the nitrogen uptake (NU and use efficiency (NUE. The grafted N can be absorbed and utilized by rice efficiently to overcome the N loss from soil-plant systems. The individual and interaction effect between the specified factors of f-MWCNTs amount (0.10–0.60 wt% and functionalization reflux time (12–24 hrs with the corresponding responses (NUE, NU were structured via the Response Surface Methodology (RSM based on five-level CCD. The UF-MWCNTs with optimized 0.5 wt% f-MWCNTs treated at 21 hrs reflux time achieve tremendous NUE up to 96% and NU at 1180 mg/pot. Significant model terms (p value < 0.05 for NUE and NU responses were confirmed by the ANOVA. Homogeneous dispersion of UF-MWCNTs was observed via FESEM and TEM. The chemical changes were monitored by FT-IR and Raman spectroscopy. Hence, this UF-MWCNTs’ approach provides a promising strategy in enhancing plant nutrition for rice.

  7. Effect of bacterial root symbiosis and urea as source of nitrogen on performance of soybean plants grown hydroponically for Bioregenerative Life Support Systems (BLSSs).

    Science.gov (United States)

    Paradiso, Roberta; Buonomo, Roberta; Dixon, Mike A; Barbieri, Giancarlo; De Pascale, Stefania

    2015-01-01

    Soybean is traditionally grown in soil, where root symbiosis with Bradyrhizobium japonicum can supply nitrogen (N), by means of bacterial fixation of atmospheric N2. Nitrogen fertilizers inhibit N-fixing bacteria. However, urea is profitably used in soybean cultivation in soil, where urease enzymes of telluric microbes catalyze the hydrolysis to ammonium, which has a lighter inhibitory effect compared to nitrate. Previous researches demonstrated that soybean can be grown hydroponically with recirculating complete nitrate-based nutrient solutions. In Space, urea derived from crew urine could be used as N source, with positive effects in resource procurement and waste recycling. However, whether the plants are able to use urea as the sole source of N and its effect on root symbiosis with B. japonicum is still unclear in hydroponics. We compared the effect of two N sources, nitrate and urea, on plant growth and physiology, and seed yield and quality of soybean grown in closed-loop Nutrient Film Technique (NFT) in growth chamber, with or without inoculation with B. japonicum. Urea limited plant growth and seed yield compared to nitrate by determining nutrient deficiency, due to its low utilization efficiency in the early developmental stages, and reduced nutrients uptake (K, Ca, and Mg) throughout the whole growing cycle. Root inoculation with B. japonicum did not improve plant performance, regardless of the N source. Specifically, nodulation increased under fertigation with urea compared to nitrate, but this effect did not result in higher leaf N content and better biomass and seed production. Urea was not suitable as sole N source for soybean in closed-loop NFT. However, the ability to use urea increased from young to adult plants, suggesting the possibility to apply it during reproductive phase or in combination with nitrate in earlier developmental stages. Root symbiosis did not contribute significantly to N nutrition and did not enhance the plant ability to use

  8. Effect of bacterial root symbiosis and urea as source of nitrogen on performance of soybean plants grown hydroponically for bioregenerative life support systems (BLSSs

    Directory of Open Access Journals (Sweden)

    Roberta eParadiso

    2015-10-01

    Full Text Available Soybean is traditionally grown in soil, where root symbiosis with Bradyrhizobium japonicum can supply nitrogen (N, by means of bacterial fixation of atmospheric N2.Nitrogen fertilizers inhibit N-fixing bacteria. However urea is profitably used in soybean cultivation in soil, where urease enzymes of telluric microbes catalyze the hydrolysis to ammonium, which has a lighter inhibitory effect compared to nitrate.Previous researches demonstrated that soybean can be grown hydroponically with recirculating complete nitrate-based nutrient solutions. In Space, urea derived from crew urine could be used as N source, with positive effects in resource procurement and waste recycling. However, whether the plants are able to use urea as the sole source of N and its effect on root symbiosis with B. japonicum is still unclear in hydroponics.We compared the effect of two N sources, nitrate and urea, on plant growth and physiology, and seed yield and quality of soybean grown in closed-loop Nutrient Film Technique (NFT in growth chamber, with or without inoculation with B. japonicum.Urea limited plant growth and seed yield compared to nitrate by determining nutrient deficiency, due to its low utilization efficiency in the early developmental stages, and reduced nutrients uptake (K, Ca and Mg throughout the whole growing cycle. Root inoculation with B. japonicum did not improve plant performance, regardless of the N source. Specifically, nodulation increased under fertigation with urea compared to nitrate, but this effect did not result in higher leaf N content and better biomass and seed production.Urea was not suitable as sole N source for soybean in closed-loop NFT. However the ability to use urea increased from young to adult plants, suggesting the possibility to apply it during reproductive phase or in combination with nitrate in earlier developmental stages. Root symbiosis did not contribute significantly to N nutrition and did not enhance the plant ability

  9. Diffusion kinetics of nitrogen in tantalum during plasma-nitriding

    Institute of Scientific and Technical Information of China (English)

    张德元; 林勤; 曾卫军; 李放; 许兰萍; 付青峰

    2001-01-01

    The activation energies of nitrogen in tantalum on plasma nitriding conditions were calculated according to the experimental data of hardness of plasma-nitriding of tantalum vs time and temperature. The activation energy calculated is 148.873±0.390  kJ/mol. The depth increasing of nitriding layer with time follows square root relation. The nitriding process of tantalum is controlled by diffusion of nitrogen atoms in tantalum solid solution.

  10. Pre-breeding blood urea nitrogen concentration and reproductive performance of Bonsmara heifers within different management systems.

    Science.gov (United States)

    Tshuma, Takula; Holm, Dietmar Erik; Fosgate, Geoffrey Theodore; Lourens, Dirk Cornelius

    2014-08-01

    This study investigated the association between pre-breeding blood urea nitrogen (BUN) concentration and reproductive performance of beef heifers within different management systems in South Africa. Bonsmara heifers (n = 369) from five herds with different estimated levels of nitrogen intake during the month prior to the commencement of the breeding season were sampled in November and December 2010 to determine BUN concentrations. Body mass, age, body condition score (BCS) and reproductive tract score (RTS) were recorded at study enrolment. Trans-rectal ultrasound and/or palpation was performed 4-8 weeks after a 3-month breeding season to estimate the stage of pregnancy. Days to pregnancy (DTP) was defined as the number of days from the start of the breeding season until the estimated conception date. Logistic regression and Cox proportional hazards survival analysis were performed to estimate the association of pre-breeding BUN concentration with subsequent pregnancy and DTP, respectively. After stratifying for herd and adjusting for age, heifers with relatively higher pre-breeding BUN concentration took longer to become pregnant when compared to those with relatively lower BUN concentration (P = 0.011). In the herd with the highest estimated nitrogen intake (n = 143), heifers with relatively higher BUN were less likely to become pregnant (P = 0.013) and if they did, it was only later during the breeding season (P = 0.017), after adjusting for body mass. These associations were not present in the herd (n = 106) with the lowest estimated nitrogen intake (P > 0.500). It is concluded that Bonsmara heifers with relatively higher pre-breeding BUN concentration, might be at a disadvantage because of this negative impact on reproductive performance, particularly when the production system includes high levels of nitrogen intake.

  11. Structural, optical and electronic characteristics of N-doped graphene nanosheets synthesized using urea as reducing agent and nitrogen precursor

    Science.gov (United States)

    Chamoli, Pankaj; Das, Malay K.; Kar, Kamal K.

    2017-01-01

    In the present study, nitrogen (N)-doped graphene nanosheets (NGns) have been synthesized by solvothermal method using urea both as the green precursor of N and as the reducing agent for graphene oxide (GO). As synthesized NGns have been characterized by x-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy, field emission scanning electron microscopy (FESEM) and x-ray photon spectroscopy (XPS). The Raman D to G band intensity ratio (I D /I G ), being a measure of defects in the honeycomb lattice, is used as an indicator for the formation of NGns. For GO:urea weight ratio of 1:5, high C to O atomic ratio (C/O) of ~8.75 with an N-content as high as ~8.3 at.% and high I D /I G ratio of 1.55 have been observed, which confirm the removal of oxygen functionalities from GO to form NGns. Further, transparent conducting films (TCFs) of the synthesized NGns have been fabricated by spray coating. Thermal graphitization of the TCFs has been performed to enhance their optical and electrical properties. When annealed at 900 °C for 1 h in vacuum, the film shows a best performance in terms of sheet resistance and transmittance values of ~1.63 kΩ □‑1 and ~68.21%, respectively.

  12. [Absorption and distribution of nitrogen from 15N labelled urea applied at core-hardening stage in winter jujube].

    Science.gov (United States)

    Zhao, Dengchao; Jiang, Yuanmao; Peng, Futian; Zhang, Jin; Zhang, Xu; Ju, Xiaotang; Zhang, Fusuo

    2006-01-01

    The study with pot experiment showed that at the rapid-swelling stage of winter jujube fruit, the percent of nitrogen derived from fertilizer (Ndff%) was the highest (10.64%) in fine roots, followed by new-growth nutritive organs. The absorbed urea-15N decreased in leaves and deciduous supers, and accumulated preferentially in root systems after harvest. The Ndff% in coarse roots was the highest (3.69%) before budding stage, while that in new-growth organs (new branches, deciduous supers, leaves and flowers) was the highest at full-blooming stage. The urea-15N applied at core-hardening stage mainly allocated in nutritive organs (leaves, deciduous supers, roots) in the first year, with the distribution rate 54.01% in root systems in winter, which was higher than that in branches (45.99%). The 15N stored in main branches changed drastically from post-harvest to budding stage. Main branches could be regarded as the 'target organs' of N storage, while coarse roots were the 'long-term sink' of N storage. The N reserve distributed preferentially in contiguity organs, and the distribution center changed with the growth and development of winter jujube in next spring.

  13. Effect of bacterial root symbiosis and urea as source of nitrogen on performance of soybean plants grown hydroponically for bioregenerative life support systems (BLSSs)

    OpenAIRE

    Roberta eParadiso; Roberta eBuonomo; Dixon, Mike A.; Giancarlo eBarbieri; Stefania eDe Pascale

    2015-01-01

    Soybean is traditionally grown in soil, where root symbiosis with Bradyrhizobium japonicum can supply nitrogen (N), by means of bacterial fixation of atmospheric N2. Nitrogen fertilizers inhibit N-fixing bacteria. However, urea is profitably used in soybean cultivation in soil, where urease enzymes of telluric microbes catalyze the hydrolysis to ammonium, which has a lighter inhibitory effect compared to nitrate. Previous researches demonstrated that soybean can be grown hydroponically with r...

  14. Thermal removal of nitrogen species from wood waste containing urea formaldehyde and melamine formaldehyde resins.

    Science.gov (United States)

    Girods, P; Dufour, A; Rogaume, Y; Rogaume, C; Zoulalian, A

    2008-11-30

    The removal of nitrogen from wood board waste through a low temperature pyrolysis (523-573 K) is investigated with two analytical methods. The kinetic study of the thermal behaviour of wood board and of its components (wood, UF and MF resins) shows the feasibility of removing thermally nitrogen from wood board waste. Indeed, the range of temperatures associated with the degradation of wood is different from the one obtained for the degradation of UF and MF resin. Isothermal conditions enable the determination of a kinetic model for degradation of wood board and of its components and demonstrate that the thermal behaviour of wood board is not the reflection of the sum of its components' behaviour. FTIR analysis of gas products confirms the feasibility removing nitrogen thermally and enables the evaluation of the optimum treatment conditions (temperature/duration). Elementary analysis of the treated samples and study of their low heating value (LHV) enable to quantify the efficiency of the thermal treatment in terms of nitrogen removal and of energy recovery. Results show that around 70% of the initial nitrogen can be removed from the waste, and that the temperature of treatment (between 523 K and 573 K) does not influence the efficiency in terms of nitrogen removal. Nevertheless, the ratio Residual energy/Initial energy (between 76% and 90%) is improved with the lowest temperature of treatment.

  15. The risk of death associated with proteinuria in heart failure is restricted to patients with an elevated blood urea nitrogen to creatinine ratio

    NARCIS (Netherlands)

    Brisco, Meredith A.; Zile, Michael R.; ter Maaten, Jozine M.; Hanberg, Jennifer S.; Wilson, F. Perry; Parikh, Chirag; Testani, Jeffrey M.

    2016-01-01

    Background: Renal dysfunction (RD) is associated with reduced survival in HF; however, not all RD is mechanistically or prognostically equivalent. Notably, RD associated with "pre-renal" physiology, as identified by an elevated blood urea nitrogen to creatinine ratio (BUN/Cr), identifies a particula

  16. The risk of death associated with proteinuria in heart failure is restricted to patients with an elevated blood urea nitrogen to creatinine ratio

    NARCIS (Netherlands)

    Brisco, Meredith A.; Zile, Michael R.; ter Maaten, Jozine M.; Hanberg, Jennifer S.; Wilson, F. Perry; Parikh, Chirag; Testani, Jeffrey M.

    2016-01-01

    Background: Renal dysfunction (RD) is associated with reduced survival in HF; however, not all RD is mechanistically or prognostically equivalent. Notably, RD associated with "pre-renal" physiology, as identified by an elevated blood urea nitrogen to creatinine ratio (BUN/Cr), identifies a particula

  17. Parâmetros fermentativos, produção de proteína microbiana, concentrações de ureia no leite e no plasma e balanço de nitrogênio de vacas alimentadas com silagem de milho ou cana-de-açúcar com caroço de algodão Fermentative parameters, microbial protein production, plasma and milk urea concentration and nitrogen balance of milking cows fed maize silage or sugarcane with whole cottonseed

    Directory of Open Access Journals (Sweden)

    Daniel de Paula Sousa

    2009-10-01

    Full Text Available Doze vacas da raça Holandesa foram distribuídas em três quadrados latinos 4 × 4 com o objetivo de avaliar o pH, o N-amoniacal, a produção de proteína microbiana, o número de protozoários no rúmen, a concentração de N-ureia no plasma e no leite e balanço de nitrogênio. Os tratamentos consistiram de silagem de milho ou cana-de-açúcar contendo 0, 7 ou 14% de caroço de algodão. Não houve diferença no pH quando fornecida cana-de-açúcar, apesar da diminuição dos valores após o início da alimentação. Os valores de N-amoniacal mantiveram-se acima de 15 mg/dL, após 6 horas de alimentação, apenas quando fornecida silagem de milho e cana-de-açúcar com 7% de caroço de algodão. O maior consumo de MS e nutrientes obtido com a silagem de milho implicou em menor eficiência de uso do nitrogênio e maiores excreções de N-ureia na urina em relação às demais dietas (150,6 vs 96,0 mg/kg PV. O fornecimento de cana-de-açúcar com 7% de caroço de algodão promoveu maiores quantidades de purinas totais (PT, purinas absorvidas (PA, nitrogênio microbiano (207, 6 vs 185,2 g/dia e melhor balanço de compostos nitrogenados (31,5 vs 15,5 em relação às demais dietas com cana-de-açúcar. O menor consumo de MS e extrato etéreo quando fornecida cana-de-açúcar sem caroço de algodão resultou em maior número de protozoários (129,4 vs 34,0 × 10³/mL, maior excreção urinária de nitrogênio e menor síntese de proteína microbiana em relação às demais dietas, o que indica falta de sincronização na degradação da energia e proteína na relação volumoso:concentrado proposta neste experimento.Twelve cows were allotted to three 4 × 4 Latin Squares to evaluate pH, ammonium nitrogen, microbial protein production, number of protozoa in the rumen, plasma and milk urea concentration and balance of nitrogen compounds. Treatments consisted of maize silage or sugarcane with whole cottonseed, at 0, 7 or 14%. There were no

  18. Speed associated with plasma pH, oxygen content, total protein and urea in an 80 km race.

    Science.gov (United States)

    Hoffman, R M; Hess, T M; Williams, C A; Kronfeld, D S; Griewe-Crandell, K M; Waldron, J E; Graham-Thiers, P M; Gay, L S; Splan, R K; Saker, K E; Harris, P A

    2002-09-01

    To test the hypothesis that endurance performance may be related quantitatively to changes in blood, we measured selected blood variables then determined their reference ranges and associations with speed during an 80 km race. The plan had 46 horses in a 2 x 2 factorial design testing a potassium-free electrolyte mix and a vitamin supplement. Blood samples were collected before the race, at 21, 37, 56 and 80 km, and 20 min after finishing, for assay of haematocrit, plasma pH, pO2, pCO2, [Na+], [K+], [Ca++], [Mg++], [Cl-], lactate, glucose, urea, cortisol, alpha-tocopherol, ascorbate, creatine kinase, aspartate amino transferase, lipid hydroperoxides, total protein, albumin and creatinine, and erythrocyte glutathione and glutathione peroxidase. Data from 34 finishers were analysed statistically. Reference ranges for resting and running horses were wide and overlapping and, therefore, limiting with respect to evaluation of individual horses. Speed correlations were most repeatable, with variables reflecting blood oxygen transport (enabling exercise), acidity and electrolytes (limiting exercise) and total protein (enabling then, perhaps, limiting). Stepwise regressions also included plasma urea concentration (limiting). The association of speed with less plasma acidity and urea suggests the potential for fat adaptation and protein restriction in endurance horses, as found previously in Arabians performing repeated sprints. Conditioning horses fed fat-fortified and protein-restricted diets may not only improve performance but also avoid grain-associated disorders.

  19. Influence of slow-release urea on nitrogen balance and portal-drained visceral nutrient flux in beef steers

    DEFF Research Database (Denmark)

    Taylor-Edwards, C C; Elam, N A; Kitts, S E

    2009-01-01

    Two experiments were conducted to evaluate the effects of slow-release urea (SRU) versus feed-grade urea on portal-drained visceral (PDV) nutrient flux, nutrient digestibility, and total N balance in beef steers.......Two experiments were conducted to evaluate the effects of slow-release urea (SRU) versus feed-grade urea on portal-drained visceral (PDV) nutrient flux, nutrient digestibility, and total N balance in beef steers....

  20. Effect of dietary nitrogen content and intravenous urea infusion on ruminal and portal-drained visceral extraction of arterial urea in lactating Holstein cows

    DEFF Research Database (Denmark)

    Kristensen, Niels Bastian; Storm, Adam Christian; Larsen, Mogens

    2010-01-01

    Urea extraction across ruminal and portal-drained visceral (PDV) tissues were investigated using 9 rumen-cannulated and multi-catheterized lactating dairy cows adapted to low-N (12.9% crude protein) and high-N (17.1% crude protein) diets in a crossover design. The interaction between adaptation...

  1. Formation of nitrogen oxides from atmospheric electrodeless microwave plasmas in nitrogen-oxygen mixtures

    Science.gov (United States)

    Lee, Jungwun; Sun, Hojoong; Im, Seong-kyun; Soo Bak, Moon

    2017-08-01

    Electrodeless microwave plasmas were produced in nitrogen-oxygen mixtures at atmospheric pressure to investigate the formation of nitrogen oxides (NOx) from the plasma. The oxygen content in the mixtures is varied in the range of 1%-3%, and the total flowrate is varied in the range of 25-45 slpm while the microwave power is fixed at 2 kW. The rotational and vibrational temperatures of the plasma are measured based on plasma optical emission spectroscopy, and the amount of NOx is measured using a NOx analyzer far downstream from the plasma. The temperatures at the plasma region reach ˜6700 K, and little difference is observed between the rotational and vibrational temperatures as a result of fast vibrational-translational relaxation. Moreover, these temperatures are found to be independent of the flowrate. As the flowrate decreases and the oxygen content in the mixture increases, the level of NOx is increased from 1612 ppm to 9380 ppm. For detailed investigation, plasma kinetic simulations considering trans-rotational, vibrational, and electron temperatures separately are developed and conducted for the plasma region. The level of NOx from the kinetic simulations is found to be considerably smaller than that measured. As the equilibrium mole fraction of NOx is the highest at a temperature of 3120 ± 100 K, with the variation attributable to the composition of species, significant production of NOx is expected to occur at the post-plasma region when the plasma stream is quenched by mixing with the surrounding flow.

  2. Urea recycling contributes to nitrogen retention in calves fed milk replacer and low-protein solid feed

    DEFF Research Database (Denmark)

    Berends, Harma; van den Borne, Joost J G C; Røjen, Betina A.;

    2014-01-01

    Urea recycling, with urea originating from catabolism of amino acids and hepatic detoxification of ammonia, is particularly relevant for ruminant animals, in which microbial protein contributes substantially to the metabolizable protein supply. However, the quantitative contribution of urea...... recycling to protein anabolism in calves during the transition from preruminants (milk-fed calves) to ruminants [solid feed (SF)-fed calves] is unknown. The aim of this study was to quantify urea recycling in milk-fed calves when provided with low-protein SF. Forty-eight calves [164 ± 1.6 kg body weight (BW......)] were assigned to 1 of 4 SF levels [0, 9, 18, and 27 g of dry matter (DM) SF · kg BW2-0.75 . d-1] provided in addition to an identical amount of milk replacer. Urea recycling was quantified after a 24-h intravenous infusion of [15N2]urea by analyzing urea isotopomers in 68-h fecal and urinary...

  3. Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor

    Institute of Scientific and Technical Information of China (English)

    V. Ravi; Young Sun Mok; B. S. Rajanikanth; Ho-Chul Kang

    2003-01-01

    An electric discharge plasma reactor combined with a catalytic reactor was studied for removing nitrogen oxides. To understand the combined process thoroughly, discharge plasma and catalytic process were separately studied first, and then the two processes were combined for the study. The plasma reactor was able to oxidize NO to NO2 well although the oxidation rate decreased with temperature. The plasma reactor alone did not reduce the NOx (NO+NO2)level effectively, but the increase in the ratio of NO2 to NO as a result of plasma discharge led to the enhancement of NOx removal efficiency even at lower temperatures over the catalyst surface (V2O5-WOa/TiO2). At a gas temperature of 100℃, the NOx removal efficiency obtained using the combined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/1.

  4. CO₂ from alcoholic fermentation for continuous cultivation of Arthrospira (Spirulina) platensis in tubular photobioreactor using urea as nitrogen source.

    Science.gov (United States)

    Matsudo, Marcelo C; Bezerra, Raquel P; Converti, Attilio; Sato, Sunao; Carvalho, João Carlos M

    2011-01-01

    Carbon dioxide released from alcoholic fermentation accounts for 33% of the whole CO(2) involved in the use of ethanol as fuel derived from glucose. As Arthrospira platensis can uptake this greenhouse gas, this study evaluates the use of the CO(2) released from alcoholic fermentation for the production of Arthrospira platensis. For this purpose, this cyanobacterium was cultivated in continuous process using urea as nitrogen source, either using CO(2) from alcoholic fermentation, without any treatment, or using pure CO(2) from cylinder. The experiments were carried out at 120 μmol photons m(-2) s(-1) in tubular photobioreactor at different dilution rates (0.2 ≤ D ≤ 0.8 d(-1) ). Using CO(2) from alcoholic fermentation, maximum steady-state cell concentration (2661 ± 71 mg L(-1) ) was achieved at D = 0.2 d(-1) , whereas higher dilution rate (0.6 d(-1) ) was needed to maximize cell productivity (839 mg L(-1) d(-1) ). This value was 10% lower than the one obtained with pure CO(2) , and there was no significant difference in the biomass protein content. With D = 0.8 d(-1) , it was possible to obtain 56% ± 1.5% and 50% ± 1.2% of protein in the dry biomass, using pure CO(2) and CO(2) from alcoholic fermentation, respectively. These results demonstrate that the use of such cost free CO(2) from alcoholic fermentation as carbon source, associated with low cost nitrogen source, may be a promising way to reduce costs of continuous cultivation of photosynthetic microorganisms, contributing at the same time to mitigate the greenhouse effect.

  5. Controlled Release Urea as a Nitrogen Source for Spring Wheat in Western Canada: Yield, Grain N Content, and N Use Efficiency

    Directory of Open Access Journals (Sweden)

    Lenz Haderlein

    2001-01-01

    Full Text Available Controlled release nitrogen (N fertilizers have been commonly used in horticultural applications such as turf grasses and container-grown woody perennials. Agrium, a major N manufacturer in North and South America, is developing a low-cost controlled release urea (CRU product for use in field crops such as grain corn, canola, wheat, and other small grain cereals. From 1998 to 2000, 11 field trials were conducted across western Canada to determine if seed-placed CRU could maintain crop yields and increase grain N and N use efficiency when compared to the practice of side-banding of urea N fertilizer. CRU was designed to release timely and adequate, but not excessive, amounts of N to the crop. Crop uptake of N from seed-placed CRU was sufficient to provide yields similar to those of side-banded urea N. Grain N concentrations of the CRU treatments were higher, on average, than those from side-banded urea, resulting in 4.2% higher N use efficiency across the entire N application range from 25 to 100 kg ha-1. Higher levels of removal of N in grain from CRU compared to side-banded urea can result in less residual N remaining in the soil, and limit the possibility of N losses due to denitrification and leaching.

  6. Urea Hydrolysis Rate in Soil Toposequences as Influenced by pH, Carbon, Nitrogen, and Soluble Metals.

    Science.gov (United States)

    Fisher, Kristin A; Meisinger, John J; James, Bruce R

    2016-01-01

    A simultaneous increase in the use of urea fertilizer and the incidence of harmful algal blooms worldwide has generated interest in potential loss pathways of urea from agricultural areas. The objective of this research was to study the rate of urea hydrolysis in soil profile toposequences sampled from the Coastal Plain (CP) and Piedmont (PM) regions of Maryland to understand native urea hydrolysis rates (UHRs) as well as the controls governing urea hydrolysis both across a landscape and with depth in the soil profile. A pH-adjustment experiment was conducted to explore the relationship between pH and urea hydrolysis because of the importance of pH to both agronomic productivity and microbial communities. Soils were sampled from both A and B horizons along transects containing an agricultural field (AG), a grassed field border (GB), and a perennially vegetated zone adjacent to surface water. On average, the A-horizon UHRs were eight times greater than corresponding B-horizon rates, and within the CP, the riparian zone (RZ) soils hydrolyzed urea faster than the agricultural soils. The pH adjustment of these soils indicated the importance of organic-matter-related factors (C, N, extractable metals) in determining UHR. These results suggest that organic-matter-rich RZ soils may be valuable in mitigating losses of urea from neighboring fields. Additional field-scale urea hydrolysis studies would be valuable to corroborate the mechanisms described herein and to explore the conditions affecting the fate and transport of urea in agroecosystems.

  7. Effects of Controlled Release Urea Combined with Conventional Urea on Grain Yield and Nitrogen Use Efficiency of Winter Wheat%控释肥料配施对冬小麦产量和氮肥利用的影响

    Institute of Scientific and Technical Information of China (English)

    栗丽; 洪坚平; 王宏庭; 谢英荷

    2012-01-01

    The field experiment was conducted by using a randomized complete block design to investigate the effects of different dosages coated controlled release urea(CRU) combined with conventional urea (U) used as basal application on the growth and development, grain yield, nitrogen uptake and utilization of winter wheat in this study. Five treatments were set, i.e. control (CK), 100% U (T1), 100% CRU (T2), 80% CRU + 20% U (T3), 60% CRU + 40% U (T4). The results showed that the 1000-grain weight, grain number per ear, harvest index and grain yield were significantly increased in the treatments of T3 and T4 compared with T1 treatment in the same N -application. The grain yield of winter wheat was increased by 7. 42% -13. 12%. Besides, in comparison with the T1 treatment, the amount of nitrogen accumulation in wheat grain was increased and the amount of residual nitrogen in vegetative organs was reduced at the mature stage in treatments T3 and T4. The nitrogen use efficiency were increased by 8. 37% ~ 14. 05% and the soil nitrogen dependency ratio was reduced by 7. 43% -11. 04% in these two treatments. Composite application of controlled-release urea and traditional urea could reduce fertilizer costs to some extent and improve the economic efficiency. In this study, the T4 treatment was recommended as the appropriate combination of controlled - release urea and traditional urea for the high grain yield, nitrogen use efficiency and maximum economic benefits.%采用完全随机区组设计,通过田间试验研究不同量的控释尿素(CRU)与普通尿素(U)配合基施(100%U,T1;100% CRU,T2;80% CRU+20%U,T3;60% CRU+40%U,T4)对冬小麦生长发育、产量及氮素吸收利用的影响.结果表明,在施氮量相等条件下,控释尿素与普通尿素配施处理(T3和T4)冬小麦千粒重、穗粒数和收获指数与单施尿素(T1)相比显著增加,冬小麦产量提高7.42%~13.12%;此外,两种尿素配施能增加冬小麦成熟期籽粒中

  8. Controlled Release Urea as a Nitrogen Source for Spring Wheat in Western Canada: Yield, Grain N Content, and N Use Efficiency

    OpenAIRE

    Lenz Haderlein; T.L. Jensen; Dowbenko, R.E.; A.D. Blaylock

    2001-01-01

    Controlled release nitrogen (N) fertilizers have been commonly used in horticultural applications such as turf grasses and container-grown woody perennials. Agrium, a major N manufacturer in North and South America, is developing a low-cost controlled release urea (CRU) product for use in field crops such as grain corn, canola, wheat, and other small grain cereals. From 1998 to 2000, 11 field trials were conducted across western Canada to determine if seed-placed CRU could maintain crop yield...

  9. Controlled Release Urea as a Nitrogen Source for Spring Wheat in Western Canada: Yield, Grain N Content, and N Use Efficiency

    OpenAIRE

    Lenz Haderlein; Jensen, T. L.; Dowbenko, R.E.; A.D. Blaylock

    2001-01-01

    Controlled release nitrogen (N) fertilizers have been commonly used in horticultural applications such as turf grasses and container-grown woody perennials. Agrium, a major N manufacturer in North and South America, is developing a low-cost controlled release urea (CRU) product for use in field crops such as grain corn, canola, wheat, and other small grain cereals. From 1998 to 2000, 11 field trials were conducted across western Canada to determine if seed-placed CRU could maintain crop yield...

  10. Optical properties of hydroxyethyl cellulose film treated with nitrogen plasma

    Science.gov (United States)

    Mahmoud, K. H.

    2016-03-01

    Hydroxyethyl cellulose (HEC) film has been prepared by casting technique. The prepared sample has been treated with nitrogen plasma at different exposure times. The optical absorption was recorded at room temperature in the wavelength range of 200-800 nm. Absorbance fitting procedure curves revealed a direct allowed transition with optical band gap, Eopt, of 4.9 eV for pristine film, and this value decreases to 4.30 eV for 20 min plasma treatment time. The band tail values (Ee) were found to be increased under plasma time treatment from 1.74 eV in case of the pristine film to 2.20 eV for 20 min. The dispersion of refractive index and complex dielectric constants under plasma treatment was also studied. Variation of color parameters under effect of the plasma treatment is analyzed in the framework of CIE L*U*V* color space.

  11. Trickling filter for urea and bio-waste processing - dynamic modelling of nitrogen cycle

    Science.gov (United States)

    Zhukov, Anton; Hauslage, Jens; Tertilt, Gerin; Bornemann, Gerhild

    Mankind’s exploration of the solar system requires reliable Life Support Systems (LSS) enabling long duration manned space missions. In the absence of frequent resupply missions, closure of the LSS will play a very important role and its maximisation will to a large extent drive the selection of appropriate LSS architectures. One of the significant issues on the way to full closure is to effectively utilise biological wastes such as urine, inedible biomass etc. A very promising concept of biological waste reprocessing is the use of trickling filters which are currently being developed and investigated by DLR, Cologne, Germany. The concept is called Combined Regenerative Organic-Food Production (C.R.O.P.) and is based on the microbiological treatment of biological wastes and reprocessing them into aqueous fertilizer which can directly be used in a greenhouse for food production. Numerous experiments have been and are being conducted by DLR in order to fully understand and characterize the process. The human space exploration group of the Technical University of Munich (TUM) in cooperation with DLR has started to establish a dynamic model of the trickling filter system to be able to assess its performance on the LSS level. In the first development stage the model covers the nitrogen cycle enabling to simulate urine processing. This paper describes briefly the C.R.O.P. concept and the status of the trickling filter model development. The model is based on enzyme-catalyzed reaction kinetics for the fundamental microbiological reaction chain and is created in MATLAB. Verification and correlation of the developed model with experiment results has been performed. Several predictive studies for batch sequencing behavior have been performed, demonstrating a good capability of C.R.O.P. concept to be used in closed LSS. Achieved results are critically discussed and way forward is presented.

  12. Study of Dynamics of Floodwater Nitrogen and Regulation of Its Runoff Loss in Paddy Field-Based Two-Cropping Rice with Urea and Controlled Release Nitrogen Fertilizer Application

    Institute of Scientific and Technical Information of China (English)

    JI Xiong-hui; ZHENG Sheng-xian; LU Yan-hong; LIAO Yu-lin

    2007-01-01

    The article deals with the effects of urea and controlled release nitrogen fertilizer (CRNF) on dynamics of pH, electronic conductivity (EC), total nitrogen (TN), NH4+-N and NO3--N in floodwater, and the regulation of runoff TN loss from paddy field-based two-cropping rice in Dongting Lake, China, and probes the best fertilization management for controlling N loss. Studies were conducted through modeling alluvial sandy loamy paddy soil (ASP) and purple calcareous clayey paddy soil (PCP) using lysimeter, following the sequence of the soil profiles identified by investigating soil profile. After application of urea in paddy field-based two-cropping rice, TN and NH4+-N concentrations in floodwater reached peak on the 1st and the 3rd day, respectively, and then decreased rapidly over time; all the floodwater NO3--N concentrations were very low; the pH of floodwater gradually rose in case of early rice within 15 d (late rice within 3 d) after application of urea,and EC remained consistent with the dynamics of NH4+-N. The applied CRNF, especially 70% CRNF, led to significantly lower floodwater TN and NH4+ concentrations, pH, and EC values compared with urea within 15 d after application. The monitoring result for N loss due to natural rainfall runoff indicated that the amount of TN lost in runoff from paddy fieldbased two-cropping rice with urea application in Dongting Lake area was 7.47 kg ha-1, which accounted for 2.49% of ureaN applied, and that with CRNF and 70% CRNF application decreased 24.5 and 27.2% compared with urea application,respectively. The two runoff events, which occurred within 20 d after application, contributed significantly to TN loss from paddy field. TN loss due to the two runoffs in urea, CRNF, and 70% CRNF treatments accounted for 72, 70, and 58% of the total TN loss due to runoff over the whole rice growth season, respectively. And the TN loss in these two CRNF treatments due to the first run-off event at the 10th day after application to early

  13. Effects of dietary crude protein and rumen-degradable protein concentrations on urea recycling, nitrogen balance, omasal nutrient flow, and milk production in dairy cows.

    Science.gov (United States)

    Mutsvangwa, T; Davies, K L; McKinnon, J J; Christensen, D A

    2016-08-01

    The objective of this study was to determine how interactions between dietary crude protein (CP) and rumen-degradable protein (RDP) concentrations alter urea-nitrogen recycling, nitrogen (N) balance, omasal nutrient flow, and milk production in lactating Holstein cows. Eight multiparous Holstein cows (711±21kg of body weight; 91±17d in milk at the start of the experiment) were used in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of dietary treatments and 29-d experimental periods. Four cows in one Latin square were fitted with ruminal cannulas to allow ruminal and omasal sampling. The dietary treatment factors were CP (14.9 vs. 17.5%; dry matter basis) and RDP (63 vs. 69% of CP) contents. Dietary RDP concentration was manipulated by including unprocessed or micronized canola meal. Diet adaptation (d 1-20) was followed by 8d (d 21-29) of sample and data collection. Continuous intrajugular infusions of [(15)N(15)N]-urea (220mg/d) were conducted for 4d (d 25-29) with concurrent total collections of urine and feces to estimate N balance and whole-body urea kinetics. Proportions of [(15)N(15)N]- and [(14)N(15)N]-urea in urinary urea, and (15)N enrichment in feces were used to calculate urea kinetics. For the low-CP diets, cows fed the high-RDP diet had a greater DM intake compared with those fed the low-RDP diet, but the opposite trend was observed for cows fed the high-CP diets. Dietary treatment had no effect on milk yield. Milk composition and milk component yields were largely unaffected by dietary treatment; however, on the low-CP diets, milk fat yield was greater for cows fed the low-RDP diet compared with those fed the high-RDP diet, but it was unaffected by RDP concentration on the high-CP diets. On the high-CP diets, milk urea nitrogen concentration was greater in cows fed the high-RDP diet compared with those fed the low-RDP diet, but it was unaffected by RDP concentration on the low-CP diets. Ruminal NH3-N concentration tended to

  14. Ammonia volatilization from surface-applied nitrogen solution of urea and ammonium nitrate; Volatizacao de amonia do solo associada a aplicacao superficial de solucao nitrogenada com ureia e nitrato de amonia

    Energy Technology Data Exchange (ETDEWEB)

    Trivellin, Paulo Cezar Ocheuze; Stefanutti, Ronaldo; Lima Filho, Oscar Fontvo de; Tziboy, Edgar Alfredo Tzi; Oliveira Junior, Jovo Alberto de; Bendassolli, Jose Albertino [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1996-08-01

    The urea is one of the fertilizers more utilized in modern agriculture. One of the problems in the urea utilization is the ammonium volatilization, resulting in low utilization of N-fertilizers by the plants.The objective of this study it was to evaluate and to compare in laboratories conditions , utilizing the {sup 15} N technic the soil`s ammonium lost by volatilization associated a superficial application of nitrogen corresponding doses like urea solution and urea and ammonium nitrates solution 2 figs.

  15. Assessment of Plasma Electrolytes, Urea and Creatinine of Patients for Adenotonsillectomy

    Directory of Open Access Journals (Sweden)

    Paul Oserhemhen Adobamen

    2014-04-01

    Conclusion: Electrolytes, urea, and creatinine derangement; especially hyponatremia, exists in patients admitted for adenotonsillectomy, mainly due to their inability to feed properly. These electrolytes should be assessed and corrected before surgery, to avoid fatal complications. [Arch Clin Exp Surg 2014; 3(2.000: 73-77

  16. Evaluation of fertilization with uncoated urea and 3,4-dimethylpyrazole phosphate (DMPP-coated urea on nitrogen leaching and rose (Rosa spp. yield

    Directory of Open Access Journals (Sweden)

    Alexandra García-Castro

    2013-06-01

    Full Text Available The negative impact of N over-fertilization has acquired importance in rose (Rosa spp. growers in Colombia. The nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP has been considered a valuable alternative to diminish the N losses by leaching and to enable more efficient N use efficiency in crops. The objective of the present work was to study the effect of DMPP on the mineral N (NH4+- N and NO3--N content in soil and water leaching, and physiological characteristics of rose plants. A greenhouse experiment was performed for 10 wk. Four-year-old 'Charlotte' rose cultivars grafted on 'Natal Briar' were grown in soil and fertirrigated daily with a complete nutrient solution containing 170 mg N L-1. Two N fertilizers (uncoated urea [UA], and urea + 1% DMPP [UDMPP] were used. Results showed that UDMPP did not show any advantages on dry mass accumulation, N use efficiency, leaf area, number of marketable stems, SPAD readings, chlorophyll fluorescence, and leaf N concentration. Despite all these results, the addition of the inhibitor reduced mean NO3-N concentrations in the percolated water by 65.81%. These results suggest that UDMPP could be a valuable tool to reduce NO3-- N leaching losses by retaining applied N in the ammoniacal form.

  17. Candidate gene association analysis for milk yield, composition, urea nitrogen and somatic cell scores in Brown Swiss cows.

    Science.gov (United States)

    Cecchinato, A; Ribeca, C; Chessa, S; Cipolat-Gotet, C; Maretto, F; Casellas, J; Bittante, G

    2014-07-01

    The aim of this study was to investigate 96 single-nucleotide polymorphisms (SNPs) from 54 candidate genes, and test the associations of the polymorphic SNPs with milk yield, composition, milk urea nitrogen (MUN) content and somatic cell score (SCS) in individual milk samples from Italian Brown Swiss cows. Milk and blood samples were collected from 1271 cows sampled once from 85 herds. Milk production, quality traits (i.e. protein, casein, fat and lactose percentages), MUN and SCS were measured for each milk sample. Genotyping was performed using a custom Illumina VeraCode GoldenGate approach. A Bayesian linear animal model that considered the effects of herd, days in milk, parity, SNP genotype and additive polygenic effect was used for the association analysis. Our results showed that 14 of the 51 polymorphic SNPs had relevant additive effects on at least one of the aforementioned traits. Polymorphisms in the glucocorticoid receptor DNA-binding factor 1 (GRLF1), prolactin receptor (PRLR) and chemokine ligand 2 (CCL2) were associated with milk yield; an SNP in the stearoyl-CoA desaturase (SCD-1) was related to fat content; SNPs in the caspase recruitment domain 15 protein (CARD15) and lipin 1 (LPIN1) affected the protein and casein contents; SNPs in growth hormone 1 (GH1), lactotransferrin (LTF) and SCD-1 were relevant for casein number; variants in beta casein (CSN2), GH1, GRLF1 and LTF affected lactose content; SNPs in beta-2 adrenergic receptor (ADRB2), serpin peptidase inhibitor (PI) and SCD-1 were associated with MUN; and SNPs in acetyl-CoA carboxylase alpha (ACACA) and signal transducer and activator of transcription 5A (STAT5A) were relevant in explaining the variation of SCS. Although further research is needed to validate these SNPs in other populations and breeds, the association between these markers and milk yield, composition, MUN and SCS could be exploited in gene-assisted selection programs for genetic improvement purposes.

  18. Reducing nitrogen oxides in exhaust gases by means of urea. Final report; Reduzierung von Stickoxiden in Abgasen mittels Harnstoff. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Koebel, M.; Elsener, M.; Marti, T. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1994-11-01

    Ammonia has been used for about twenty years as a selective reducing agent for reducing NO{sub x} in lean exhaust gases containing excess oxygen. Although urea has distinct advantages compared with ammonia (solid substance, cheap, practically nontoxic, not explosive) it has hardly been considered for this purpose. In the present work the possibilities of using aqueous urea solutions for the DeNOx processes based on selective catalytic reduction (SCR) and selective non catalytic reduction (SNCR) are explored. SCR: Urea-SCR poses little problems: If the process equipment is properly designed, no appreciable emissions of flue gas components related to urea are found, e.g. isocyanic acid, hydrogen cyanide, nitrous oxide, urea, biuret, cyanuric acid and melamine. On the other hand, like ammonia, use of urea leads to an emission of ammonia which limits the maximum attainable degree of NO{sub x} reduction. With industrial bulk catalysts based on TiO{sub 2}-WO{sub 3}-V{sub 2}O{sub 5} and gas hourly space velocities of 10`000 h{sup -1}, NO{sub x} reductions of over 98% at an ``ammonia slip`` below 10 ppm may be attained. SNCR: The use of urea instead of ammonia shifts the optimum temperature window upwards by about 50 K. Besides an ``ammonia slip``, some isocyanic acid is found, and the emissions of carbon monoxide and nitrous oxide are definitely higher. As nitrous oxide is considered to be a greenhouse gas and a scavenger of stratospheric ozone, the use of urea is no longer recommended in future SNCR installations. If the advantages of storage convenience of urea to be combined optimally with the advantages of ammonia as selective reducing agent, the hydropyrolysis of urea in an external reactor is a possible solution. (author) 38 figs., 5 tabs., 36 refs.

  19. Interactive effects of water and controlled release urea on nitrogen metabolism, accumulation, translocation, and yield in summer maize

    Science.gov (United States)

    Li, Guanghao; Zhao, Bin; Dong, Shuting; Zhang, Jiwang; Liu, Peng; Vyn, Tony J.

    2017-10-01

    To investigate the interactive effects of water and N from controlled release urea (CRU) on N metabolism, accumulation, translocation, and yield in Zhengdan958 (a summer maize cultivar planted widely in China), three water levels (adequate water W3, mild water stress W2, severe water stress W1) and four amounts of CRU (N) (N0, N1, N2, and N3 were 0, 105, 210, and 315 kg N ha-1, respectively) were carried out under the waterproof shed and soil column conditions. The results showed that yield, N metabolism, accumulation, and translocation were significantly affected by water, CRU, and their interactions after tasseling. Yields showed an increasing trend in response to N rates from 100.2 to 128.8 g plant-1 under severe water stress (W1), from 124.7 to 174.6 g plant-1 under mild water stress (W2), and from 143.7 to 177.0 g plant-1 under adequate water conditions (W3). There was an associated optimum amount of N for each water level. Under W1 and W2, N3 treatments showed significant advantages in three N metabolism enzymes' activities and the N accumulations, and yield and its components were highest. But the nitrogen harvest index (NHI) of N3 had no significant difference with other nitrogen treatments. Under W3, the N translocation efficiency (NTE) and N translocation conversion rate (NTCR) of N2 in stem and leaf were higher than those of N3, but the N metabolism enzymes' activities and yields of N2 and N3 had no significant difference, which indicated that N2 was superior to N3. The N3 treatment under W2 and N2 under W3 increased the N accumulation capacity in maize grain as well as the N translocation to grain that contributed to the increase of 1000-gain weight and grains per ear after tasseling. Under this experimental condition, a CRU rate of 225 kg ha-1 was the best treatment when the soil moisture content was 75 ± 5% of field capacity, but an N rate of 300 kg ha-1 was superior when soil moisture content was maintained at 55 ± 5% of field capacity during the

  20. Effect of Tree Leaves on Rumen Fermentation, Microbial Count and Blood Urea Nitrogen of West African Dwarf Goats

    Directory of Open Access Journals (Sweden)

    Adelusi, O. O.

    2016-12-01

    Full Text Available This experiment was carried out to assess the effect of Azadirachta indica, Newbouldia laevis and Spondias mombin leaves on rumen fermentation, microbial count and blood urea nitrogen (BUN of West African Dwarf (WAD goats. Sixteen WAD bucks (11.6 ? 0.9 kg in body weight were allocated to 4 treatments: 1 Control and 2 40 g/day of Azadirachta indica, 3 40 g/day of Newbouldia laevis and 4 40 g/day of Spondias mombin leaves arranged in a completely randomised design. The ground leaves were included in concentrate diets served on dry matter basis at 2% of body weight while Panicum maximum was fed ad libitum. The control diet had no tree leaves. Data were collected on chemical composition, rumen fermentation and microbial ecology, and BUN. Saponin was highest (P < 0.05 in S. mombin (8.14% while A. indica and N. laevis had 5.78% and 1.56%, respectively. Rumen ammonia nitrogen was least (P < 0.05 in goats fed A. indica (8.35 mg/dL while the highest (P < 0.05 total volatile fatty acid (TVFA was obtained from goats fed S. mombin with 125.51 mM. Goats fed N. laevis yielded the highest (P < 0.05 acetate with 70.65 mol/100 mol while propionate production was highest (P < 0.05 in the rumen of goats fed S. mombin (27.15 mol/100 mol. Viable bacteria count was lowest (P < 0.05 in rumen of goats fed A. indica (3.95?1012 cfu/ml while the least (P < 0.05 protozoa population was obtained from the rumen of bucks fed S. mombin (4.18?109 cfu/ml. All goats in the treatments containing tree leaves had higher (P < 0.05 and a rapid increase in BUN between 0 and 6 h post feeding when compared with the Control. It is concluded that feeding ground leaves of S. mombin to goats increases rumen total volatile fatty acid and propionate production and reduces the protozoa population.

  1. Effect of nitrogen doping on the microstructure and visible light photocatalysis of titanate nanotubes by a facile cohydrothermal synthesis via urea treatment

    Science.gov (United States)

    Hu, Cheng-Ching; Hsu, Tzu-Chien; Lu, Shan-Yu

    2013-09-01

    A facile one-step cohydrothermal synthesis via urea treatment has been adopted to prepare a series of nitrogen-doped titanate nanotubes with highly efficient visible light photocatalysis of rhodamine B, in an effect to identify the effect of nitrogen doping on the photodegradation efficiency. The morphology and microstructure of the thus-prepared N-doped titanates were characterized by nitrogen adsorption/desorption isotherms, transmission electron microscopy, and scanning electron microscopy. With increasing urea loadings, the N-doped titanates change from a porous multi-layer and nanotube-shaped to a dense and aggregated particle-shaped structure, accompanied with reduced specific surface area and pore volume and enhanced pore diameter. Interstitial linkage to titanate via Tisbnd Osbnd N and Tisbnd Nsbnd O is confirmed by X-ray photoelectron spectroscopy. Factors governing the photocatalytic degradation such as the specific surface area of the catalyst and the degradation pathway are analyzed, a mechanistic illustration on the photodegradation is provided, and a 3-stage degradation mechanism is identified. The synergistic contribution due to the enhanced deethylation and chromophore cleavage on rhodamine B molecules and the reduced band gap on the catalyst TiO2 by interstitial nitrogen-doping has been accounted for the high photodegradation efficiency of the N-doped titanate nanotubes.

  2. Effect of nitrogen doping on the microstructure and visible light photocatalysis of titanate nanotubes by a facile cohydrothermal synthesis via urea treatment

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Cheng-Ching; Hsu, Tzu-Chien, E-mail: tjhsu@facmail.nsysu.edu.tw; Lu, Shan-Yu

    2013-09-01

    A facile one-step cohydrothermal synthesis via urea treatment has been adopted to prepare a series of nitrogen-doped titanate nanotubes with highly efficient visible light photocatalysis of rhodamine B, in an effect to identify the effect of nitrogen doping on the photodegradation efficiency. The morphology and microstructure of the thus-prepared N-doped titanates were characterized by nitrogen adsorption/desorption isotherms, transmission electron microscopy, and scanning electron microscopy. With increasing urea loadings, the N-doped titanates change from a porous multi-layer and nanotube-shaped to a dense and aggregated particle-shaped structure, accompanied with reduced specific surface area and pore volume and enhanced pore diameter. Interstitial linkage to titanate via Ti-O-N and Ti-N-O is confirmed by X-ray photoelectron spectroscopy. Factors governing the photocatalytic degradation such as the specific surface area of the catalyst and the degradation pathway are analyzed, a mechanistic illustration on the photodegradation is provided, and a 3-stage degradation mechanism is identified. The synergistic contribution due to the enhanced deethylation and chromophore cleavage on rhodamine B molecules and the reduced band gap on the catalyst TiO{sub 2} by interstitial nitrogen-doping has been accounted for the high photodegradation efficiency of the N-doped titanate nanotubes.

  3. The rationale for alternative fertilization: Equilibrium isotherm, kinetics and mass transfer analysis for urea-nitrogen adsorption from cow urine

    Directory of Open Access Journals (Sweden)

    M. Ganesapillai

    2015-12-01

    Full Text Available In an effort to minimize the loss of urea-N through volatilization and concurrently recover urea in a usable form from cow urine, adsorption experiments using bamboo-based activated carbon were performed. Batch studies were undertaken to evaluate the effect of initial concentration, sorption time and temperature on the variation in urea uptake capacity of the prepared carbon. Equilibrium data were tested against various isotherms, kinetics and mass transfer models. The Langmuir monolayer sorption was found to be 146.12 mg.g−1 with nearly 90% urea recovery attained. The process was found to be reversible as seen through regeneration experiments. Thermodynamic parameters indicated that urea sorption was physical, spontaneous and exothermic in nature. Kinetic studies revealed that the rate of urea uptake was limited by both surface adsorption and intra-particle diffusion. It was concluded that the mass transfer of urea molecules over the activated carbon was governed by film diffusion at all concentrations examined.

  4. A rapid and sensitive method for determination of dimethyl benzoylphenyl urea in human plasma by using LC/MS/MS.

    Science.gov (United States)

    Zhao, Ming; Zabelina, Yelena; Rudek, Michelle A; Wolff, Antonio C; Baker, Sharyn D

    2003-11-24

    Dimethyl benzoylphenyl urea (BPU), a poorly water-soluble benzoylphenyl urea derivative, inhibits tubulin polymerization and causes microtubule depolymerization in vitro with activity against solid tumors. BPU is currently being tested in Phase I clinical trials. A rapid, sensitive and specific method using LC/MS/MS has been developed for the quantitation of BPU in human plasma to perform pharmacokinetic (PK) and pharmacodynamic (PD) studies of BPU administered orally once a week. BPU is extracted from plasma into acetonitrile-n-butylchloride and separated on a Waters X-Terra MS C18 (50 x 2.1 mm, 3.5 microm) column with acetonitrile/water mobile phase (80:20, v/v) containing 0.1% formic acid using isocratic flow at 0.15 ml/min for 5 min. The analyte of interest was monitored by tandem-mass spectrometry with electrospray positive ionization with a cone voltage 15 V for BPU and 30 V for the internal standard, paclitaxel. The detector settings allowed the monitoring of the [MH](+) ion of BPU (m/z 470.3) and the [MH](+) of internal standard paclitaxel (m/z 854.5), with subsequent monitoring of the product ions of BPU (m/z 148.0) and paclitaxel (m/z 286.1). Calibration curves were generated over the range of 0.05-10 ng/ml with values for coefficient of determination of >0.99. The values for precision and accuracy were BPU 5 mg as a weekly oral dose to a patient with advanced solid tumor malignancies, the maximum plasma concentration was 6.5 ng/ml and concentrations were quantifiable up to 173 h after administration. The lower limit of quantitation (LLOQ) of 0.05 ng/ml allows for successful measurement of plasma concentrations in patients receiving therapy with BPU as a once weekly oral dose.

  5. Blood Urea Nitrogen Test

    Science.gov (United States)

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  6. Kinetics of the urea-induced dissociation of human plasma alpha-2-macroglobulin as measured by small-angle neutron scattering

    DEFF Research Database (Denmark)

    Sjöberg, B.; Pap, S.; Järnberg, S.-E.;

    1991-01-01

    The kinetics of the urea-induced dissociation of human plasma alpha-2-macroglobulin into two half-molecular fragments was investigated at 21.0-degrees-C by using small-angle neutron scattering. The relative change in molecular mass that occurs upon dissociation was monitored by recording...... with a drastic change in structure. This is directly shown by the radius of gyration, which increases from about 7.4 nm immediately after the addition of urea up to about 9.4 nm when the protein is fully dissociated. A structural analysis shows that the scattering curve of urea-dissociated alpha-2-macroglobulin...... the forward scattering of neutrons as a function of time. All these kinetic data can be explained by a reaction that is first-order with respect to the concentration of undissociated alpha-2-macroglobulin. The velocity constant is a function of urea concentration and it varies within wide limits. For instance...

  7. Does blood urea nitrogen level predict severity and high-risk endoscopic lesions in patients with nonvariceal upper gastrointestinal bleeding?

    Science.gov (United States)

    Al-Naamani, Khalid; Alzadjali, Nabil; Barkun, Alan N; Fallone, Carlo A

    2008-01-01

    BACKGROUND: Nonvariceal upper gastrointestinal bleeding (UGIB) is a serious medical condition requiring prompt resuscitation and early endoscopic therapy in those with high-risk endoscopic lesions (HRLs). There are little or no data correlating sole blood urea nitrogen (BUN) level with the severity of nonvariceal UGIB or the presence of HRLs in the adult population. OBJECTIVES: To determine if the BUN level on presentation correlates with parameters of severity of UGIB (need for blood transfusion or intensive care unit [ICU] admission) or to the subsequent finding of HRL, and in so doing identify patients who will require early endoscopic intervention. METHODS: The Canadian Registry of patients with Upper Gastrointestinal Bleeding undergoing Endoscopy was used to identify patients enrolled from the McGill University Health Centre (Montreal, Quebec) who presented with or developed acute nonvariceal UGIB while admitted. All comparisons were performed using Student’s t test or Wilcoxon’s signed rank test, as appropriate. Logistic regression modelling using a stepwise method was performed to identify independent predictors of severe nonvariceal UGIB and HRL. RESULTS: Two hundred nine patients were enrolled in the study. The mean age was 67±18 years and 59.8% were male. The mean BUN level was 13.4±9.4 mmol/L. Univariate analysis demonstrated that the BUN level was a significant predictor of ICU admission (BUN 14.7±10.4 mmol/L versus 12.0±8.0 mmol/L, P=0.035). However, when adjusted for systolic blood pressure, BUN level became a weaker predictor of ICU admission, just failing to achieve statistical significance (OR 1.03, 95% CI 1.00 to 1.06; P=0.08). Univariate analysis also demonstrated that BUN level was not a statistically significant predictor of blood transfusion requirement (BUN 14.1±10.6 mmol/L versus 13.6±8.6 mmol/L, P=0.508), nor of HRL (BUN 14.2±10.7 mmol/L versus 12.9±8.6 mmol/L, P=0.605). CONCLUSION: In patients with nonvariceal UGIB, the BUN

  8. Milk yield and blood urea nitrogen in crossbred cows grazing Leucaena leucocephala in a silvopastoral system in the Mexican tropics

    Directory of Open Access Journals (Sweden)

    Maria B. Bottini-Luzardo

    2016-09-01

    Full Text Available The aim of the study was to assess milk yields, estimate the intake of crude protein (CP and determine the concentrations of blood urea nitrogen (BUN in early post-partum crossbred cows grazing irrigated Leucaena leucocephala (leucaena in a silvopastoral system relative to those in an irrigated grass monoculture.  Twenty-four multiparous cows were randomly allotted at calving on the basis of previous milk yields to 2 grazing treatments: grass monoculture system (MS of Cynodon nlemfuensis (n=12; and an intensive silvopastoral system (ISS composed of leucaena and C. nlemfuensis (n=12.  Cows were supplemented with sorghum grain (ISS or a conventional concentrate (MS during milking to ensure availability of metabolizable energy (ME and CP required for milk production.  Mean estimated intake of leucaena was 5.1±1.3 kg DM/d and estimated CP intakes were 1,479±3.3 and 1,258±3.3 g/d for ISS and MS, respectively (P>0.05, while estimated intakes of ME were 161±1.3 and 131±1.4 MJ/d for ISS and MS, respectively (P<0.05.  Milk yields were 13.5 and 14.5 kg/cow/d for cows on ISS and MS, respectively (P>0.05.  Concentrations of BUN were 19.1 mg/dL for cows in ISS and 15.3 mg/dL for cows in MS (P<0.05.  We conclude that intake of leucaena and sorghum grain in an irrigated silvopastoral system was sufficient to substitute for expensive concentrate in the diets of lactating cows grazing irrigated grass monoculture.  However, the higher levels of BUN found in ISS suggest a lower efficiency of N utilization in this treatment.  Restricting consumption of leucaena might be a means of improving efficiency of its use and this warrants investigation. Keywords: Cattle, crude protein, Cynodon nlemfuensis, leucaena, tropical pasturesDOI: 10.17138/TGFT(4159-167

  9. A method for determination of dimethyl benzoylphenyl urea (BPU) in human plasma by using LC/UV.

    Science.gov (United States)

    Rudek, Michelle A; Zabelina, Yelena; Zhao, Ming; Wolff, Antonio C; Baker, Sharyn D

    2004-06-01

    Dimethyl benzoylphenyl urea (BPU) inhibited tubulin polymerization, caused microtubule depolymerization in vitro and demonstrated activity against solid tumors. BPU is being tested in phase I clinical trials. A rapid and specific method using LC/UV has been developed for quantitation of BPU in human heparin-containing plasma to perform pharmacokinetic and pharmacodynamic studies. BPU is extracted from plasma into acetonitrile:n-butyl-chloride using paclitaxel as the internal standard and separated on a Waters Symmetry C18 (3.9 x 150 mm, 5 microm) column with acetonitrile-water mobile phase (70:30, v/v) using isocratic flow at 1 mL/min for a run time of 5 min. Ultraviolet detection was utilized and performed at 225 nm for BPU and paclitaxel. The retention times were 1.9 min for paclitaxel and 4.1 min for BPU. Calibration curves were generated over the range of 0.01-10 microg/mL with coefficient of determination of > 0.99. The values for within-day and between-day precision were BPU 320 mg as a weekly oral dose to a patient with advanced solid tumor malignancies, the maximum plasma concentration was 2 micro g/mL and concentrations were quantifiable up to 168 h after administration. The lower limit of quantitation of 0.01 microg/mL allows for successful measurement of plasma concentrations in patients.

  10. 竹炭包膜尿素的氮素释放规律和生物利用效果研究%Study on the Nitrogen Release Law of Bamboo Charcoal-coated Urea and Its Biological Utilization Effects

    Institute of Scientific and Technical Information of China (English)

    纪锐琳; 朱义年; 张爱莉; 张学洪

    2007-01-01

    [Objective]The study about the nitrngen releasing law of bamboo-charcoal coated urea and the biologic utilization effect wag to find the coated urea with high efficiency,low price and simple production technology.[Method]Two kinds of bamboo-charcoal coated urea(BCCU)with different coating thickness were made by using bambon-charcoal and macromolecule polymer as coating material.The experiments of soil eluviate,ammonia volatilization in corn field and potted plant of corn were conducted to study the nitrogen releasing law and the bidngic utilization effect of self-made BCCU.[Result]The BCCU showed some slow-release capability and their accumulated nitrogen releasing rates in 29 d were 9.93%-16.27% lower than that of norlnal urea.Compared With the normal urea,the volatilization rate of ammoniain BCCU reduced to 16.66%-31.8%,the biomass of Crn and nitrogen utilization rate increased by 12.8%-24.1%and 10.5%-16.99%,respectively.[Conclusion]Bamboo-charcoal in coated urea not only had some slow-release capabjlity.but also had some adsorbability,Which would reducethe eluviation and volatilization of nitrogen and protect environment from N pollution.

  11. ARTICLES: Methanol Tolerant Non-noble Metal Co-C-N Catalyst for Oxygen Reduction Reaction Using Urea as Nitrogen Source

    Science.gov (United States)

    Si, Yu-jun; Chen, Chang-guo; Yin, Wei; Cai, Hui

    2010-06-01

    A non-noble metal oxygen reduction reaction (ORR) catalyst labeled as Co-C-N(800) was synthesized by heat-treating a mixture of urea, cobalt chloride and acetylene black for 2 h at 800 °C in an inert nitrogen atmosphere. X-ray diffraction pattern indicates that a metallic β-Co is generated after the heat-treating process. The results from cyclic voltammograms show that the obtained Co-C-N(800) catalyst has good ORR catalytic activity in 0.5 mol/L H2SO4 solution. The catalyst is also good at methanol tolerance and stability in the acidic solution.

  12. Facile synthesis of nitrogen-doped graphene via pyrolysis of graphene oxide and urea, and its electrocatalytic activity toward the oxygen-reduction reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Ziyin; Waller, Gordon; Liu, Yan; Liu, Meilin [School of Materials Science and Engineering, Georgia Institube of Technology, Atlanta, Georgia (United States); Wong, Ching-Ping [School of Materials Science and Engineering, Georgia Institube of Technology, Atlanta, Georgia (United States); Department of Electronic Engineering, Chinese University of Hong Kong (China)

    2012-07-15

    Nitrogen-doped graphene (NG) is a promising metal-free catalyst for the oxygen-reduction reaction (ORR). A facile and low-cost synthesis of NG via the pyrolysis of graphene oxide and urea is reported. The N content in NG can be up to 7.86%, with a high percentage of graphitic N({approx}24%), which gives rise to an excellent catalytic activity toward the ORR. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Molecular Nitrogen Vibrational Temperature in an Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    康正德; 蒲以康

    2002-01-01

    Using a technique applied previously to vibrationally excited molecular nitrogen (N*2) in the region of daytime and nighttime aurora, the emission intensity of the N2 second positive band system in an inductively coupled plasma (ICP) has been analysed and the vibrational temperature of nitrogen molecules in the ICP is thus determined. The result shows that the vibrational temperature increases with the increase of the neutral gas pressure from 0.04Pa to 10Pa, then decreases with the further increase of the pressure from 10Pa to 100Pa. Also,this is explained by using the Boltzmann relation between the vibrational temperature and the concentration of the vibrationally excited N*2(X1∑+g ) molecules.

  14. On the Plasma (ion) Carburized Layer of High Nitrogen Austenitic Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    Y. Ueda; N. Kanayama; K. Ichii; T. Oishi; H. Miyake

    2004-01-01

    The manganese concentration of austenitic stainless steel decreases from the inner layer towards the surface of the plasma (ion) carburized layer due to the evaporation of manganese from the specimen surface. The carbon concentration in the carburized layer is influenced by alloyed elements such as Ct, Ni, Si, and Mo, as well as Nitrogen. This study examined the effects of nitrogen on the properties of the carburized layer of high nitrogen stainless steel. Plasma (ion)carburizing was carried out for 14.4 ks at 1303 K in an atmosphere of CH4+H2 gas mixtures under a pressure of 350 Pa. The plasma carburized layer of the high nitrogen stainless steel was thinner than that of an austentric stainless steel containing no nitrogen. This suggested that the nitrogen raised the activity of carbon in the plasma carburized layer, GDOES measurement indicated that the nitrogen level in the layer did not vary after plasma (ion) carburizing.

  15. Digestibility, fecal characteristics, and plasma glucose and urea in dogs fed a commercial dog food once or three times daily.

    Science.gov (United States)

    Brambillasca, Sebastián; Purtscher, Frederick; Britos, Alejandro; Repetto, José L; Cajarville, Cecilia

    2010-02-01

    Digestibility, fecal characteristics, and levels of glucose and urea in the plasma were determined in 8 dogs that received 2 different dog foods once or 3 times daily. One dog food (A) was 5 times more expensive than the other (B). Fecal pH and consistency, digestibility of dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) were determined. Blood samples were taken from 30 min before to 60 min after a meal. Digestibilities of DM, OM, and CP, and fecal consistency were higher, and daily fecal excretion and fecal pH were lower when dogs were fed food A (P food 3 frequency interactions was significant for the parameters studied.

  16. Urea and short-chain fatty acids metabolism in Holstein cows fed a low-nitrogen grass-based diet

    DEFF Research Database (Denmark)

    Røjen, B A; Lund, P; Kristensen, N B

    2008-01-01

    Three ruminally cannulated and multicatheterised lactating dairy cows were used to investigate the effect of different supplement strategies to fresh clover grass on urea and short-chain fatty acid (SCFA) metabolism in a zero-grazing experiment with 24-h blood and ruminal samplings.......Three ruminally cannulated and multicatheterised lactating dairy cows were used to investigate the effect of different supplement strategies to fresh clover grass on urea and short-chain fatty acid (SCFA) metabolism in a zero-grazing experiment with 24-h blood and ruminal samplings....

  17. Urea in sugarcane-based diets for dairy cows

    Directory of Open Access Journals (Sweden)

    Alberto Magno Ferreira Santiago

    2013-06-01

    Full Text Available We evaluated the effect of adding four levels (0, 4, 8 and 12 g/kg, as fed of a mixture (9:1 of urea and ammonium sulfate (UAs to sugarcane on feed intake and digestibility, productive performance and metabolism of nitrogen compounds of dairy cows. Twelve multiparous Holstein cows (12.6±0.5 kg/d of milk, 225±90 days in milk were distributed in three 4 × 4 Latin squares, receiving diets with the same amount of nitrogen (125 g crude protein/kg of dry matter. Concentrate feed was supplied at a ratio of 1 kg for each 3 kg of milk produced. The sugarcane presented 21.9 ºBrix. The level of UAs did not affect intake, total digestibility of diet components, milk production or milk components. Increasing UAs level linearly increased concentration of plasma urea nitrogen (PUN, urinary excretion of nitrogen and contribution of non-urea nitrogen in the urinary excretion and linearly reduced milk production/urinary excretion of nitrogen ratio. In spite of the linear increase of PUN with increased urea, the maximum value observed (14.31 mg/dL was below the threshold value of 20 mg/dL, above which reproductive function may be compromised. In diets with sugarcane for dairy cows with production below 15 kg/day, the UAs level may be raised from 0 to 12 g/kg natural matter without impairing performance.

  18. Noteworthy impacts of polyurethane-urea ionomers as the efficient polar coatings on adhesion strength of plasma treated polypropylene

    Science.gov (United States)

    Chashmejahanbin, Mohammad. R.; Daemi, Hamed; Barikani, Mehdi; Salimi, Ali

    2014-10-01

    In present research, polypropylene (PP) was selected as a model nonpolar substrate for chemical modification using plasma. In the first step, the PP samples were treated using oxygen and argon atmospheres, individually. The prepared samples were analyzed using both FTIR and AFM techniques. The output of these techniques revealed that the carbonyl, carboxylic acid and its derivatives have been formed on the surface of PP. Afterward, a series of aqueous polyurethane-urea dispersions were synthesized as the novel polar coating for modified nonpolar polymers and characterized by different techniques including FTIR, DSC, TGA, mechanical properties and contact angle. Finally, the plasma treated samples were coated by prepared polyurethane ionomer. The results of pull-off analysis confirmed the significant role of the polyurethane as an extremely polar coating to create hydrogen bonding with functional groups on the surface of treated PP. The adhesion strength of polypropylenes increased from 0.04 MPa to 0.61 MPa for neat and oxygen-based plasma treated samples, respectively.

  19. Ruminal characteristics, blood pH, blood urea nitrogen and nitrogen balance in Nili-Ravi buffalo (bubalus bubalis bulls fed diets containing various level of ruminally degradable protein

    Directory of Open Access Journals (Sweden)

    M.A. Shahzad

    2010-02-01

    Full Text Available Ruminal degradable protein (RDP is considered essential for ruminal microbial growth. This not only improves the ruminal fermentation but it also ensures an adequate supply of microbial protein to the host animal. One of the most effective methods to enhance ruminal microbial protein supplies to the host is an efficient utilization of non-protein nitrogen substances (Sarwar et al., 2004. This makes the ruminant animal production cost-effective through minimizing its ruminally undegradable protein (RUP needs (Blummel et al., 1999. Urea can be used all or a part of the supplemental protein to meet the dairy cow requirement (Russell et al., 1992. It is documented that exotic lactating cows perform equally good when urea contributes to build up 12 % RDP of the ration (Gould, 1969. However, scientific information regarding this effect in buffalo is limited. Therefore the present study was planned to determine the impact of varying level of RDP on ruminal characteristics, digestibility, blood pH, blood urea nitrogen (BUN and N balance in buffalo bulls.

  20. Plasma-polymerized hexamethyldisilazane treated by nitrogen plasma immersion ion implantation technique

    Energy Technology Data Exchange (ETDEWEB)

    Honda, R Y; Mota, R P; Batocki, R G S; Santos, D C R; Nicoleti, T; Kostov, K G; Kayama, M E; Algatti, M A [Laboratorio de Plasma, Faculdade de Engenharia, UNESP, Av. Dr Ariberto Pereira da Cunha-333, 12516-410, Guaratingueta, SP (Brazil); Cruz, N C [Laboratorio de Plasmas Tecnologicos, Unidade Diferenciada, UNESP, Av. Tres de Marco-511, 18085-180, Sorocaba, SP (Brazil); Ruggiero, L, E-mail: honda@feg.unesp.b [Faculdade de Ciencias, UNESP, Av. Luis E. Carrijo Coube 14-1, 17033-360, Bauru, SP (Brazil)

    2009-05-01

    This paper describes the effect of nitrogen Plasma Immersion Ion Implantation (PIII) on chemical structure, refraction index and surface hardness of plasma-polymerized hexamethyldisilazane (PPHMDSN) thin films. Firstly, polymeric films were deposited at 13.56 MHz radiofrequency (RF) Plasma Enhanced Chemical Vapour Deposition (PECVD) and then, were treated by nitrogen PIII from 15 to 60 min. Fourier Transformed Infrared (FTIR) spectroscopy was employed to analyse the molecular structure of the samples, and it revealed that vibrations modes at 3350 cm{sup -1}, 2960 cm{sup -1}, 1650 cm{sup -1}, 1250 cm{sup -1} and 1050 cm{sup -1} were altered by nitrogen PIII. Visible-ultraviolet (vis-UV) spectroscopy was used to evaluate film refractive index and the results showed a slight increase from 1.6 to 1.8 following the implantation time. Nanoindentation revealed a surface hardness rise from 0.5 to 2.3 GPa as PIII treatment time increased. These results indicate nitrogen PIII is very promising in improving optical and mechanical properties of PPHMDSN films.

  1. Cecotrophy behavior and use of urea as non-protein nitrogen (NPN) source for capybara (Hydrochoerus hydrochaeris).

    Science.gov (United States)

    Nogueira-Filho, Sérgio Luiz Gama; Mendes, Alcester; Tavares, Ellis Fernanda Kowalski; da Cunha Nogueira, Selene Siqueira

    2013-11-01

    Fifteen female adult capybaras, with initial average body weight (BW) of 32.7 (± 5.8) kg, were kept in individual pens to evaluate effect of supplementation of concentrate feed and its supply time on cecotrophy behavior frequency. The animals were allocated in a completely randomized design, with five animals per treatment, receiving three diets: grass only, grass and grain corn offered in a single meal, and grass and grain corn offered in two daily meals; all cecotrophy acts were recorded. Later, in a second experiment, five capybaras received five levels of urea in their diet: 0, 10, 20, 30, and 40 g urea/100 kg BW, replacing soybean meal as true protein source, in a 5 × 5 Latin square design. The animals were weighed and their blood was collected every 2 weeks. The frequency of cecotrophy (Ps capybaras were fed grass only (0.5 ± 0.07 acts/h) than when they received grass and corn in a single meal (0.3 ± 0.05 acts/h) and grass and corn supplied in separate meals (0.1 ± 0.03 acts/h). With increased urea in their diet, the capybaras showed initial signs of chronic intoxication, together with increments in serum urea (r = 0.87, P capybara diet, these must be mixed with roughage in a single meal to avoid high decrease in the frequency of cecotrophy behavior and increase in dry matter intake. The replacement of soybean meal with urea in capybara diet is not recommended.

  2. Urea transporters UT-A1 and UT-A3 accumulate in the plasma membrane in response to increased hypertonicity.

    Science.gov (United States)

    Blessing, Nathan W; Blount, Mitsi A; Sands, Jeff M; Martin, Christopher F; Klein, Janet D

    2008-11-01

    The UT-A1 and UT-A3 urea transporters are expressed in the terminal inner medullary collecting duct (IMCD) and play an important role in the production of concentrated urine. We showed that both hyperosmolarity and vasopressin increase urea permeability in perfused rat terminal IMCDs and that UT-A1 and UT-A3 accumulate in the plasma membrane in response to vasopressin. In this study, we investigated whether hyperosmolarity causes UT-A1 and/or UT-A3 to accumulate in the plasma membrane or represents a complimentary stimulatory pathway. Rat IMCD suspensions were incubated in 450 vs. 900 mosM solutions. We biotinylated the IMCD surface proteins, collected, and analyzed them. Membrane accumulation was assessed by Western blotting of the biotinylated protein pool probed with anti-UT-A1 or anti-UT-A3. We studied the effect of NaCl, urea, and sucrose as osmotic agents. Membrane-associated UT-A1 and UT-A3 increased relative to control levels when either NaCl (UT-A1 increased 37 +/- 6%; UT-A3 increased 46 +/- 13%) or sucrose (UT-A1 increased 81 +/- 13%; UT-A3 increased 60 +/- 8%) was used to increase osmolarity. There was no increase in membrane UT-A1 or UT-A3 when urea was added. Analogously, UT-A1 phosphorylation was increased in NaCl- and sucrose- but not in urea-based hyperosmolar solutions. Hypertonicity also increased UT-A3 phosphorylation. We conclude that the increase in the urea permeability in response to hyperosmolarity reflects both UT-A1 and UT-A3 movement to the plasma membrane and may be a direct response to tonicity. Furthermore, this movement is accompanied by, and may require, increased phosphorylation in response to hypertonicity.

  3. Controlled Phase Changes of Titania Using Nitrogen Plasma

    Science.gov (United States)

    Trejo-Tzab, R.; Caballero-Espada, Liliana; Quintana, P.; Ávila-Ortega, Alejandro; Medina-Esquivel, R. A.

    2017-01-01

    In this work, the development of a new crystallization technique is reported, using nitrogen plasma (AC) to obtain nanostructured anatase and rutile from amorphous titanium oxide (TiO2). This methodology increases throughput and minimizes thermal effects. Nanostructured amorphous TiO2 was obtained by the sol-gel method and subsequently subjected to AC treatment, at a controlled pressure, applying different powers and treatment times in order to obtain phase changes. The obtained samples were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The results show the crystallization in parallel with anatase and rutile phases with a proportion that is directly related to the applied power in the plasma and the treatment time. This technique allows us to obtain smaller crystals in comparison with those of classic thermal methodologies. It is also demonstrated that the application of plasma represents a novel and innovative method to obtain phase polymorphic changes in titanium oxide without needing to apply prolonged heat treatments at high temperatures and can therefore be taken into consideration as a technique with low energy costs, in comparison with conventional heat treatments.

  4. Nitrogen oxides and methane treatment by non-thermal plasma

    Science.gov (United States)

    Alva, E.; Pacheco, M.; Colín, A.; Sánchez, V.; Pacheco, J.; Valdivia, R.; Soria, G.

    2015-03-01

    Non thermal plasma was used to treat nitrogen oxides (NOx) and methane (CH4), since they are important constituents of hydrocarbon combustion emissions processes and, both gases, play a key role in the formation of tropospheric ozone. These gases are involved in environmental problems like acid rain and some diseases such as bronchitis and pneumonia. In the case of methane is widely known its importance in the global climate change, and currently accounts for 30% of global warming. There is a growing concern for methane leaks, associated with a rapid expansion of unconventional oil and gas extraction techniques as well as a large-scale methane release from Arctic because of ice melting and the subsequent methane production of decaying organic matter. Therefore, methane mitigation is a key to avoid dangerous levels of global warming. The research, here reported, deals about the generation of non-thermal plasma with a double dielectric barrier (2DBD) at atmospheric pressure with alternating current (AC) for NOx and CH4 treatment. The degradation efficiencies and their respective power consumption for different reactor configurations (cylindrical and planar) are also reported. Qualitative and quantitative analysis of gases degradation are reported before and after treatment with cold plasma. Experimental and theoretical results are compared obtaining good removal efficiencies, superior to 90% and to 20% respectively for NOx and CH4.

  5. New Insights in Nutritional Management and Amino Acid Supplementation in Urea Cycle Disorders

    OpenAIRE

    Scaglia, Fernando

    2010-01-01

    Sodium phenylbutyrate is used in the pharmacological treatment of urea cycle disorders to create alternative pathways for nitrogen excretion. The primary metabolite, phenylacetate, conjugates glutamine in the liver and kidney to form phenylacetylglutamine that is readily excreted in the urine. Patients with urea cycle disorders taking sodium phenylbutyrate have a selective reduction in the plasma concentrations of branched chain amino acids despite adequate dietary protein intake. Moreover, t...

  6. Macronutrient digestibility, nitrogen balance, plasma indicators of protein metabolism and mineral absorption in horses fed a ration rich in sugar beet pulp.

    Science.gov (United States)

    Olsman, A F S; Huurdeman, C M; Jansen, W L; Haaksma, J; Sloet van Oldruitenborgh-Oosterbaan, M M; Beynen, A C

    2004-10-01

    In a cross-over study with six mature horses, the effect of iso-energetic replacement of dietary glucose by beet pulp on macronutrient digestibility, nitrogen metabolism and mineral absorption was studied. The test ration contained 25% beet pulp in the total dietary dry matter. Beet pulp feeding significantly lowered crude fat and non-structural carbohydrate digestibility, but had no significant effect on digestibility of other macronutrients, faecal and urinary nitrogen excretion and the faecal to urinary nitrogen excretion quotient. However, on the beet pulp diet, plasma ammonia and creatinin concentrations were significantly lower than on the glucose diet. No diet effect on magnesium absorption was observed. It is suggested that dietary beet pulp stimulates the conversion of ammonia into urea.

  7. Comparative nitrogen use efficiency of urea and pig slurry for regrowth yield and nutritive value in perennial ryegrass sward.

    Science.gov (United States)

    Park, Sang Hyun; Lee, Bok Rye; Cho, Won Mo; Kim, Tae Hwan

    2017-04-01

    The study aimed to assess the N use efficiency (NUE) of pig slurry (in comparison with chemical fertilizer) for each regrowth yield and annual herbage production and their nutritive value. Consecutive field experiments were separately performed using a single application with a full dose of N (200 kg N/ha) in 2014 and by four split applications in 2015 in different sites. The experiment consisted of three treatments: i) control plots that received no additional N, ii) chemical fertilizer-N as urea, and iii) pig-slurry-N with five replicates. The effect of N fertilization on herbage yield, N recovery in herbage, residual inorganic N in soil, and crude protein were significantly positive. When comparing the NUE between the two N sources (urea and pig slurry), pig slurry was significantly less effective for the earlier two regrowth periods, as shown by lower regrowth dry matter (DM) yield, N amount recovered in herbage, and inorganic N availability in soil at the 1st and 2nd cut compared to those of urea-applied plots. However, the effect of split application of the two N sources was significantly positive at the last two regrowth periods (at the 3rd and 4th cut). The two N sources and/or split application had little or no influence on neutral detergent fiber (NDF) content, acid detergent fiber (ADF) content, and in vitro DM digestibility, whereas cutting date was a large source of variation for these variables, resulting in a significant increase in in vitro DM digestibility for the last two regrowth periods when an increase in NDF and ADF content occurred. Split application of N reduced the N loss via nitrate leaching by 36% on average for the two N sources compared to a single application. The pig slurry-N was utilized as efficiently as urea-N for annual herbage yield, with a significant increase in NUE especially for the latter regrowth periods.

  8. Comparative nitrogen use efficiency of urea and pig slurry for regrowth yield and nutritive value in perennial ryegrass sward

    Directory of Open Access Journals (Sweden)

    Sang Hyun Park

    2017-04-01

    Full Text Available Objective The study aimed to assess the N use efficiency (NUE of pig slurry (in comparison with chemical fertilizer for each regrowth yield and annual herbage production and their nutritive value. Methods Consecutive field experiments were separately performed using a single application with a full dose of N (200 kg N/ha in 2014 and by four split applications in 2015 in different sites. The experiment consisted of three treatments: i control plots that received no additional N, ii chemical fertilizer-N as urea, and iii pig-slurry-N with five replicates. Results The effect of N fertilization on herbage yield, N recovery in herbage, residual inorganic N in soil, and crude protein were significantly positive. When comparing the NUE between the two N sources (urea and pig slurry, pig slurry was significantly less effective for the earlier two regrowth periods, as shown by lower regrowth dry matter (DM yield, N amount recovered in herbage, and inorganic N availability in soil at the 1st and 2nd cut compared to those of urea-applied plots. However, the effect of split application of the two N sources was significantly positive at the last two regrowth periods (at the 3rd and 4th cut. The two N sources and/or split application had little or no influence on neutral detergent fiber (NDF content, acid detergent fiber (ADF content, and in vitro DM digestibility, whereas cutting date was a large source of variation for these variables, resulting in a significant increase in in vitro DM digestibility for the last two regrowth periods when an increase in NDF and ADF content occurred. Split application of N reduced the N loss via nitrate leaching by 36% on average for the two N sources compared to a single application. Conclusion The pig slurry-N was utilized as efficiently as urea-N for annual herbage yield, with a significant increase in NUE especially for the latter regrowth periods.

  9. Estimate of production of gaseous nitrogen in the human body based on (15)N analysis of breath N2 after administration of [(15)N2]urea.

    Science.gov (United States)

    Junghans, Peter

    2013-01-01

    After oral administration of [(15)N2]urea (1.5 mmol, 95 atom% (15)N), we found that breath N2 was significantly (15)N-labelled. The result suggests that molecular nitrogen in breath must be partly produced endogenously. Based on a metabolic model, the endogenous N2 production was estimated to be 0.40±0.25 mmol kg(-1) d(-1) or 2.9±1.8 % of the total (urinary and faecal) N excretion in fasted healthy subjects (n=4). In patients infected with Helicobacter pylori (n=5), the endogenous N2 production was increased to 1.24±0.59 mmol kg(-1) d(-1) or 9.0±4.3 % of the total N excretion compared to the healthy controls (pstress-related diseases such as H. pylori infections.

  10. Molecular dynamics simulations of aqueous urea solutions: Study of dimer stability and solution structure, and calculation of the total nitrogen radial distribution function GN(r)

    Science.gov (United States)

    Boek, E. S.; Briels, W. J.

    1993-01-01

    Molecular dynamics simulations have been performed in order to study the structure of two molal urea solutions in D2O. Several initial dimer configurations were considered for an adequate sampling of phase space. Eventually all of them appeared to be unstable, when system size and periodic boundary conditions are chosen properly, even after a very careful equilibration. The total nitrogen scattering function GN(r), calculated from these simulations, is in good agreement with neutron scattering experiments when both intra- and intermolecular correlations are considered and the experimental truncation ripples are introduced by a Fourier transform of GN(r) back and forth. The simple pair potential model that we used gives results in good agreement with experiments and with a much more involved potential model, recently described in the literature [J. Chem. Phys. 95, 8419 (1991)].

  11. Synthesis and Characterization of Nitrogen-Doped Graphene

    OpenAIRE

    Palaniuk, D. Ryan

    2012-01-01

    Approved for public release; distribution is unlimited Self standing nitrogen doped graphene sheets were produced by reduction-expansion method, which utilizes graphite oxide (GO) and urea as precursor materials. For comparison, an Atmospheric Microwave Plasma Torch system (ATP) was used to produce graphene samples under argon and nitrogen atmospheres from GO. Graphene samples were characterized by XRD, TEM, SEM, BET and Raman Spectroscopy. The GO and urea mixtures decomposition-reduction ...

  12. Plasma levels of arginine, ornithine, and urea and growth performance of broilers fed supplemental L-arginine during cool temperature exposure.

    Science.gov (United States)

    Ruiz-Feria, C A; Kidd, M T; Wideman, R F

    2001-03-01

    Two experiments (Experiment 1 and 2) were conducted to evaluate growth performance, ascites mortality, and concentrations of plasma Arg, urea, and ornithine in male broilers raised in floor pens (2 x 4 factorial experiment, six pens for treatment) and exposed to cool temperatures averaging 16 C after 21 d of age. Broilers were fed low- or high-CP diets in both Experiments. In Experiment 1, Arg treatments consisted of control (no supplemental Arg); 0.15 or 0.3% supplemental Arg in the diet (low- and medium-Arg feed, respectively); and 0.3% supplemental Arg in the drinking water (Arg-water). Arginine levels were increased in Experiment 2 and consisted of the following: control (no supplemental Arg); 0.3 or 0.85% supplemental Arg in the diet (medium- and high-Arg feed, respectively); and 0.6% supplemental Arg in the drinking water (Arg-water). The water treatment followed a 3-d cyclic regimen, with supplemental Arg being provided for 24 h, followed by tap water for 48 h. When the broilers reached 37 d of age and all groups had consumed tap water for the previous 48 h, blood samples were collected from one bird per pen (Time 0, 0700 h); then supplemental Arg was provided in the Arg-water group, and additional blood samples were collected from the control and Arg-water groups at 3, 6, 12, and 36 h after Time 0. Plasma amino acids were analyzed using HPLC. Birds fed the high-CP diet were heavier at 49 d than birds fed the low-CP diet in Experiment 1, but not in Experiment 2. No differences were found in feed conversion or ascites mortality due to CP or Arg treatments in either experiment. In both experiments, plasma Arg was similar for all groups at Time 0, but increased in the Arg-water group at 3, 6, and 12 h after Arg was provided in the water. Within 12 h after returning to tap water, plasma Arg levels of the Arg-water group did not differ from the control group. Plasma urea and ornithine were parallel to plasma Arg concentrations, and the high-CP diets resulted in

  13. Nitrogen-doped graphene by all-solid-state ball-milling graphite with urea as a high-power lithium ion battery anode

    Science.gov (United States)

    Liu, Chao; Liu, Xingang; Tan, Jiang; Wang, Qingfu; Wen, Hao; Zhang, Chuhong

    2017-02-01

    Nitrogen-doped graphene nanosheets (NGNS) are prepared by a novel mechanochemical method via all-solid-state ball-milling graphite with urea. The ball-milling process does not only successfully exfoliate the graphite into multi-layer (low cost and good water solubility that can simplify the fabrication process. The as-prepared NGNS are investigated in detail by XRD, SEM, HRTEM, TGA, XPS and Raman spectroscopy. The doping nitrogens are around 3.15% and dominated (>94%) by pyrindic-N and pyrrolic-N which facilitates the NGNS with enhanced electronic conductivity and Li-ion storage capability. For the first time, we demonstrate that the all-solid-state prepared NGNS exhibits, especially at high currents, enhanced cycling stability and rate capability as Lithium ion battery (LIB) anode active material when compared to pristine graphite and undoped graphene in half-cell configuration. The method presented in this article may provide a simple, clean, economical and scalable strategy for preparation of NGNS as a feasible and promising anode material for LIBs.

  14. ROW METHOD OF SUGAR BEET (BETA VULGARIS L. FERTILIZATION WITH MULTICOMPONENT FERTILIZER BASED ON UREA-AMMONIUM NITRATE SOLUTION AS A WAY TO INCREASE NITROGEN EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Przemysław BARŁÓG

    2010-12-01

    Full Text Available Sugar beet is the main crop commonly cultivated for sugar production in temperate regions of the World. Actual yields in main Central Europe producing countries are much lower, due to many limiting factors. Among them, nutrients supply is of great value, especially referring to efficiency of nitrogen, which is generally low. In the conducted study two methods of nitrogen application were compared (i broadcast of calcium saltpeter and (ii row application of the multicomponent fertilizer based on urea-ammonium-nitrate (UAN solution. The basic amount of the applied N was 75 kg ha-1. The highest yields of both taproots and refined sugar were harvested on the plot receiving 75 kg N-1 as UAN liquid multicomponent fertilizer and 50% of the recommended P and K rates. The positive effects of row application of liquid N fertilizer on taproot and sugar yields were also corroborated by high values of indices of agronomic efficiency for both N as well as P and K. However this method of sugar beets fertilization has some possibilities, as indicated by still high contents of melassogenic substances.

  15. Synthesis and characterization of well-aligned carbon nitrogen nanotubes by microwave plasma chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Well-aligned carbon nitrogen nanotube films have been synthesized successfully on mesoporous silica substrates by microwave plasma chemical vapor deposition (MWPCVD) method. Studies on their morphology, structure, and composition by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX), respectively, indicate that these nanotubes consist of linearly polymerized carbon nitrogen nanobells, and the nitrogen atoms have been doped into carbon netweork to form a new structure C1-xNx (x=0.16±0.01). X-ray photoelectron spectroscopy (XPS) results of the samples further demonstrate that carbon bonds covalently with nitrogen in all the carbon nitrogen nanotube films.

  16. 15N Isotope Techniques for Estimating Effects of Urea-N Fertilizer Application Rate on Yieids and Nutrient Contents of Pakchoi Cabbage and Asparagus Lettuce and Nitrogen Utilization Efficiency

    Institute of Scientific and Technical Information of China (English)

    LIAO Yu-Iin; ZHENG Sheng-xian; RONG Xiang-min; LIU Qiang; FAN Mei-rong

    2010-01-01

    A pot experiment combined with15 N isotope techniques was conducted to evaluate effects of the varying rates of urea.N fertilizer application on yields,quailty,and nitrogen use efficiency(NUE)of pakchoi cabbage(Brassica chinensis L.)and asparagus lettuce(Lactuca saiva L.).15 N-labbled urea(5.35 15 N atom%)was added to pots with 6.5kg soil of 0.14,0.18,0.21,0.25,and 0.29 g N/kg soil.and applied in two splits:60 percenl as basel dressing in the mixture and 40 percent as toodressing.The fresh yields of two vegetable species increased with the increasing input of urea-N,but there was a significant quadratic relationship between the dose of urea-N fertilizer application and the fresh yields.Whan the dosage of urea-N fertilizer reached a certain value,nitrate readily accumulated in the two kinds of plants due to the decrease in NR activity;furthermore,there was a linear nagative correlation between nitrate content and NR activity.With the increasing input of urea-N.ascorbic acid and soluble sugar initially increased,declined after a while,and crude fiber rapidly decreased too.Total absorbed N(TAN).N derived from fertilizer(Ndff),and N derived from soil(Ndfs)increased,and the ratio of Ndff and TAN also increased.but the ratio of Ndfs and TAN as well as NUE of urea-N fertilizer decreased with the increasing input of urea-N.These results suggested that the increasing application of labeled N fertilizer led lo the increase in unlabeled N(namely,Ndfs)presumably due to"added nitrogen interaction"(ANI),the decease in NUE of urea-N fertilizer may be due to excess fertilization beyond the levels of plant requirements and the ANI.and the decrease jn the two vege table yields with the increasing addition of urea-N possibly because the excess accumulation of nitrate reached a toxic level.

  17. Investigation on the mechanism of nitrogen plasma modified PDMS bonding with SU-8

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chengxin; Yuan, Yong J., E-mail: yongyuan@swjtu.edu.cn

    2016-02-28

    Graphical abstract: - Highlights: • Different nitrogen plasma processes modified PDMS bonding with SU-8 had been studied. • The effect of nitrogen plasma modification would produce the best result and the recovery of PDMS hydrophobicity could be delayed. - Abstract: Polydimethylsiloxane (PDMS) and SU-8 are both widely used for microfluidic system. However, it is difficult to permanently seal SU-8 microfluidic channels using PDMS with conventional methods. Previous efforts of combining these two materials mainly employed oxygen plasma modified PDMS. The nitrogen plasma modification of PDMS bonding with SU-8 is rarely studied in recent years. In this work, the mechanism of nitrogen plasma modified PDMS bonding with SU-8 was investigated. The fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and contact angle of a water droplet were used to analyze the nitrogen plasma modified surface and the hydrophilic stability of PDMS samples. Pull-off tests were used for estimating the bonding effect of interface between nitrogen plasma modified PDMS and SU-8.

  18. Use of Several Plant Materials and Chemicals to inhibit Soil Urease Activity and Increase Nitrogen Recovery Rate of Urea by Plant

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Effects of residues of 9 plants, lemon eucalyptus (Eucalyptus citriodora Hook., P1), robust eucalyptus (E. robusta Smith, P2), Nepal camphortree (Cinnamomum glanduliferum (Wall.) Nees, P3), tea (Camellia sinensis (Linn.) O. Ktze. f., P4), oleander (Nerium indicum Mill, P5), rape (Brassica campestris L., P6),Chinese tallow tree (Sapium sebiferum L., P7), tung (Vernicia fordii (Hemsl.), P8), and croton (Croton tiglium L., P9), 7 chemicals, boric acid (C1), borax (C2), oxalic acid (C3), sodium oxalite (C4), sodium dihydrogen phosphate (C6), sodium silicate (C7) and sodium citrate (C8), and a natural organic substance,humic acid (C5), on urease activity of a neutral purple soil and recovery of urea nitrogen by maize were studied through incubation and pot experiments. Hydroquinone (HQ) was applied as the reference inhibitor. After incubation at 37 ℃ for 24 h, 7 inhibitors with higher ability to inhibit urease activity were selected and then incubated for 14 days at 25 ℃. Results of the incubation experiments showed that soil urease activity was greatly inhibited by them, and the inhibition effect followed an order of P2>P4>C3>C2>P3>C1>HQ>P1.The 7 selected materials reduced the accumulative amounts of N released from urea and the maximum urease activity by 11.7%~28.4% and 26.7%~39.7%, respectively, and postponed the N release peak by 2~4 days in the incubation period of 14 days under constant temperature, as compared to the control (no inhibitor).In the pot experiment with the 7 materials at two levels of addition, low (L) and high (H), the C1 (H), C3(H), C1 (L), P4 (L) and C2 (L) treatments could significantly increase the dry weights of the aboveground parts and the total biomass of the maize plants and the apparent recovery rate of urea-N was increased by 6.3%~32.4% as compared to the control (no hibitor).

  19. Functional characterization of mouse urea transporters UT-A2 and UT-A3 expressed in purified Xenopus laevis oocyte plasma membranes.

    Science.gov (United States)

    Maciver, Bryce; Smith, Craig P; Hill, Warren G; Zeidel, Mark L

    2008-04-01

    Urea is a small solute synthesized by many terrestrial organisms as part of the catabolism of protein. In mammals it is transported across cellular membranes by specific urea transporter (UT) proteins that are the products of two separate, but closely related genes, referred to as UT-A and UT-B. Three major UT-A isoforms are found in the kidney, namely UT-A1, UT-A2, and UT-A3. UT-A2 is found in the thin, descending limb of the loop of Henle, whereas UT-A1 and UT-A3 are concentrated in the inner medullary collecting duct. UT-A2 and UT-A3 effectively represent two halves of the whole UT-A gene and, when joined together by 73 hydrophilic amino acids, constitute UT-A1. A biophysical characterization of mouse UT-A2 and UT-A3 was undertaken by expression in Xenopus laevis oocytes and subsequent preparation of highly enriched plasma membrane vesicles for use in stopped-flow fluorometry. Both isoforms were found to be highly specific for urea, and did not permeate water, ammonia, or other molecules closely related to urea (formamide, acetamide, methylurea, and dimethylurea). Single transporter flux rates of 46,000 +/- 10,000 and 59,000 +/- 15,000 (means +/- SE) urea molecules/s/channel for UT-A2 and UT-A3, respectively, were obtained. Overall, the UT-A2 and UT-A3 isoforms appear to have identical functional kinetics.

  20. Modulation of the gut microbiota with antibiotic treatment suppresses whole body urea production in neonatal pigs

    DEFF Research Database (Denmark)

    Puiman, Patrycja; Stoll, Barbara; Mølbak, Lars

    2013-01-01

    administered antibiotics, or probiotics affects whole body nitrogen and amino acid turnover. We quantified whole body urea kinetics, threonine fluxes, and threonine disposal into protein, oxidation, and tissue protein synthesis with stable isotope techniques. Compared with controls, antibiotics reduced...... the number and diversity of bacterial species in the distal small intestine (SI) and colon. Antibiotics decreased plasma urea concentrations via decreased urea synthesis. Antibiotics elevated threonine plasma concentrations and turnover, as well as whole body protein synthesis and proteolysis. Antibiotics...... in the proximal SI but not in other tissues. In conclusion, modulation of the gut microbiota by antibiotics and probiotics reduced hepatic ureagenesis and intestinal protein synthesis, but neither altered whole body net threonine balance. These findings suggest that changes in amino acid and nitrogen metabolism...

  1. Fertilización de maíz con urea de liberación lenta: pérdida por volatilización y eficiencia de uso de nitrógeno Corn fertilization with slow-solubilization urea: ammonia volatilization losses and nitrogen use efficiency

    Directory of Open Access Journals (Sweden)

    PA Barbieri

    2010-07-01

    Full Text Available Las pérdidas de nitrógeno (N reducen la eficiencia de uso de dicho nutriente (EUN. Se han desarrollado productos tales como el copolímero maleico-itacónico (NSN y triamida N-(n-butil tiofosfórica (nBTPT que agregados a la urea disminuyen la tasa de liberación de N pudiendo reducir las pérdidas. El objetivo fue determinar durante dos años las pérdidas por volatilización de N-NH3, la respuesta en rendimiento, el N en grano y la EUN del cultivo de maíz bajo SD desde urea tratada con dichos productos. Para ello se realizaron experimentos utilizando Urea, Urea+NSN y Urea+nBTPT, en combinación con dosis de N (60 y 120 kg ha-1. Las pérdidas de N-NH3 se extendieron por 7 y 18 días para el Año 1 y 2, respectivamente. En ambos años, las pérdidas de N-NH3 determinadas para Urea fueron superiores respecto de Urea+ aditivos. Las pérdidas en el Año 1 desde Urea fueron del 3 y 10% para 60 y 120 kg de N ha¹, respectivamente, mientras que desde Urea+NSN no superaron el 0,5% para ambas dosis. En el Año 2, las pérdidas desde Urea fueron 2,3 y 3,8% para 60 y 120 kg de N ha-1, respectivamente, mientras que desde Urea+NSN y Urea+nBTPT no superaron el 2% para ambas dosis. El rendimiento no se incrementó por el aumento de la dosis de N ni por el uso de NSN y nBTPT. El N en grano se incrementó con la dosis de N, mientras que la utilización de NSN y nBTPT no afectó dicha variable. La EUN, eficiencia fisiológica y de recuperación disminuyeron con el incremento de la dosis de N y no fue afectada por el uso de NSN y nBTPT. La utilización de dichos productos si bien fue efectiva para reducir las pérdidas por volatilización, no produjo incrementos significativos en rendimiento, contenido de N en grano y EUN, comportamiento que puede ser debido a que las pérdidas de N en estas condiciones no fue un mecanismo relevante.Nitrogen (N loss reduces the efficient use of this nutrient (EUN. When added to Urea, products such as the maleic

  2. Formation of InN nanoparticle and nanorod structures by nitrogen plasma annealing method

    Indian Academy of Sciences (India)

    Ajay Kumar Mann; Deepak Varandani; Bodh Raj Mehta; Lalit Kumar Malhotra; G Mangamma; A K Tyagi

    2008-06-01

    In the present study, a novel method involving nitrogen plasma annealing has been reported for preparing InN nanoparticle/nanorod structures and for improving the properties of InN nanoparticle layers. Plasma annealed structures have been characterized by X-ray diffraction, atomic force microscopy and photoluminescence spectroscopy techniques. InN nanoparticle layers have been prepared using activated reactive evaporation set up. It has been observed that there is a remarkable improvement in the conductivity and crystallinity of InN nanoparticle layers on annealing in nitrogen plasma. This has been attributed to the increase in the nitrogen content of the samples. Experiments involving plasma annealing of In nanorods deposited oxide template has also been carried out. It was found that on plasma treatment In nanorods get converted to mixed phase InN nanorods with hexagonal and cubic fractions.

  3. Balanço de nitrogênio e estimativas de perdas endógenas em vacas lactantes alimentadas com dietas contendo palma forrageira e teores crescentes de uréia e mandioca = Nitrogen balance and endogenous loss estimate in lactating cows fed with diets of forage cactus and increasing levels of urea and cassava

    Directory of Open Access Journals (Sweden)

    Maria Cláudia Soares Cruz

    2006-01-01

    Full Text Available Foram avaliados os efeitos da substituição do farelo de soja pela mistura uréia mais mandioca, em rações constituídas de palma, silagem de sorgo e concentrado, sobre concentrações de uréia, balanço de nitrogênio (N e estimativas de perdas endógenas totais em 8 vacas Girolando em lactação, distribuídas em dois quadrados latinos simultâneos (4x4. As concentrações de uréia e N-uréico no plasma e leite, em mg/dL e N-uréico no leite (g/dia não foram afetadas pelo aumento do nível de uréia na ração, apresentando médias de 31,37;14,62; 37,43; 17,44; 5,37. As excreções urinárias de uréia e N-uréico também não foram influenciadas, com médias de 249,45 e 116,24 mg/kg PV. Igualmente, o balanço de N não foi afetado pelos tratamentos, cujos valores médios foram de 87,75; 87,63; 62,91; 60,97 g/dia,respectivamente, para 0%, 1,00%, 1,90% e 2,86% de uréia na ração. As estimativas das perdas endógenas variaram de acordo com o sistema de exigência nutricional utilizado.The effects of the soybean when replaced by a mixture of urea and cassava, in rations composed of forage cactus, sorghum silage and concentrate, were assessed on: (i urea concentration; (ii nitrogen (N balance; and (iii total endogenous loss estimate. Eight lactating Holstein/Zebu cows were distributed in two 4x4 simultaneous latin squares. Urea and N-urea concentration in plasma and milk (mg dL-1, and milk N-urea (g day-1 were not affected by the increase of urea levels in the ration; their means were 31.37, 14.62, 37.43, 17.44, and 5.37, respectively. Also, urea and N-urea urinary excretion were not affected by the increase of urea levels in the ration, and the mean values of those parameters were 249.45 and 116.24 mg kg-1 LW, respectively. The treatments did not influence N levels, with average values of 87.75, 87.63, 62.91, and 60.97 g day-1 to 0, 1.06, 2.12 e 3.20 % of urea addition in the ration, respectively. The endogenous loss estimate varied

  4. Synthesis of silicon carbide in a nitrogen plasma torch: rotational temperature determination and material analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Camacho, J; Castell, R [Universidad Simon BolIvar, Departamento de Fisica, Caracas (Venezuela, Bolivarian Republic of); Castro, A; Manrique, M [Universidad Simon BolIvar, Departamento de Ciencias de los Materiales, Caracas (Venezuela, Bolivarian Republic of)], E-mail: jgruiz@usb.ve

    2008-09-07

    Experiments on silicon carbide synthesis were performed using a dc nitrogen plasma torch. Measurements of rotational temperature of nitrogen molecules by emission spectroscopy were performed, based on the band (0, 1) of the first negative system of nitrogen N{sub 2}{sup +}(B{sup 2}{sigma}{sub u}{sup +}{yields}X{sup 2}{sigma}{sub g}{sup +}) for the R branch. Three different plasma torch powers were studied in order to optimize the production of silicon carbide with our experimental set-up. The synthesized products were characterized by x-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy.

  5. Synthesis of silicon carbide in a nitrogen plasma torch: rotational temperature determination and material analysis

    Science.gov (United States)

    Ruiz-Camacho, J.; Castell, R.; Castro, A.; Manrique, M.

    2008-09-01

    Experiments on silicon carbide synthesis were performed using a dc nitrogen plasma torch. Measurements of rotational temperature of nitrogen molecules by emission spectroscopy were performed, based on the band (0, 1) of the first negative system of nitrogen N_2^+ (B\\,{}^2\\Sigma_u^+ \\to X\\,{}^2\\Sigma _g^+) for the R branch. Three different plasma torch powers were studied in order to optimize the production of silicon carbide with our experimental set-up. The synthesized products were characterized by x-ray diffraction, scanning electron microscopy and energy dispersive x-ray spectroscopy.

  6. 控释尿素在夏玉米上的施用效果及氮素利用率研究%Results of Controlled Release Urea Application on Summer Corn and Study of Nitrogen Availability

    Institute of Scientific and Technical Information of China (English)

    孙克刚; 和爱玲; 胡颖; 赵丽君; 薛毅芳

    2013-01-01

    通过田间试验方法,对比评价控释尿素在夏玉米上的施用效果和方法.根据施用控释尿素对玉米籽粒产量、氮素吸收和利用率的影响,探讨控释尿素在夏玉米上的施用效果.试验结果表明:与普通尿素相比,施用控释尿素后,玉米产量及氮素利用率均明显提高.%Through field experiments the results and methods of comparison and evaluation are given for the application of controlled release urea on summer corn. Based on the effect of controlled release urea applied on the output of corn seed and nitrogen absorption and utilization, the results are investigated of controlled release urea applied on summer corn. The experimental results show that with the application of controlled release urea, both the corn yield and nitrogen availability increase significantly.

  7. Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage.

    Science.gov (United States)

    Batista, E D; Detmann, E; Titgemeyer, E C; Valadares Filho, S C; Valadares, R F D; Prates, L L; Rennó, L N; Paulino, M F

    2016-01-01

    Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers () consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 ± 9 kg) were used in a 5 × 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [NN]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected ( ≥ 0.37) by supplementation, but supplementation did increase ruminal NDF digestion ( Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation ( urea entry rate and tended ( = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended ( = 0.07) to be increased by supplementation, and RUP provision also tended ( = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater ( urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis.

  8. Impact of nitrification inhibitor with organic manure and urea on nitrogen dynamics and N2O emission in acid sulphate soil

    Directory of Open Access Journals (Sweden)

    Shordar Mohamed Shamsuzzaman

    2015-01-01

    Full Text Available ABSTRACT The accurate prediction of N transformation is an important requisite for optimizing N use efficiency in cropping systems. An incubation study was conducted to verify the impacts of nitrification inhibitor (NI with organic manure (OM and urea on N dynamics and N2O emission in acid sulphate soil. The conducted experiment was two-level factorial with 4 N sources (N1 = 100% of N from urea, N2 = 75% of N from urea + 25% N from rice straw, N3 = 75% of N from urea + 25% of N from cow dung and N4 = 75% of N from urea + 25% of N from poultry dung and two levels of NI (with and without DCD. The NI (Dicyandiamide - DCD with OM + urea enhanced mineral N contents and it was the highest (255.07 µg∙g-1 for urea with DCD applications. The highest net N-mineralization (213.07 µg∙g-1 was recorded for the application of urea with DCD and net nitrification (16.26 µg∙g-1 was recorded for the application of urea alone, but the highest cumulative N2O emission (5.46 µg∙g-1 was in urea + poultry dung (PD. In addition, DCD most effectively inhibited net nitrification (28.78% and N2O emission (32.40% from cow dung (CD and urea in the tested soils. The combination of DCD with CD and urea was more effective in reducing N2O emissions (43.69%. These results suggest that the DCD with CD and urea may be the most potential combination to reduce nitrification and N2O emission as well as N loss from acid sulphate soil.

  9. Impact of nitrification inhibitor with organic manure and urea on nitrogen dynamics and N2O emission in acid sulphate soil

    Directory of Open Access Journals (Sweden)

    Shordar Mohamed Shamsuzzaman

    2016-03-01

    Full Text Available ABSTRACT The accurate prediction of N transformation is an important requisite for optimizing N use efficiency in cropping systems. An incubation study was conducted to verify the impacts of nitrification inhibitor (NI with organic manure (OM and urea on N dynamics and N2O emission in acid sulphate soil. The conducted experiment was two-level factorial with 4 N sources (N1 = 100% of N from urea, N2 = 75% of N from urea + 25% N from rice straw, N3 = 75% of N from urea + 25% of N from cow dung and N4 = 75% of N from urea + 25% of N from poultry dung and two levels of NI (with and without DCD. The NI (Dicyandiamide - DCD with OM + urea enhanced mineral N contents and it was the highest (255.07 µg∙g-1 for urea with DCD applications. The highest net N-mineralization (213.07 µg∙g-1 was recorded for the application of urea with DCD and net nitrification (16.26 µg∙g-1 was recorded for the application of urea alone, but the highest cumulative N2O emission (5.46 µg∙g-1 was in urea + poultry dung (PD. In addition, DCD most effectively inhibited net nitrification (28.78% and N2O emission (32.40% from cow dung (CD and urea in the tested soils. The combination of DCD with CD and urea was more effective in reducing N2O emissions (43.69%. These results suggest that the DCD with CD and urea may be the most potential combination to reduce nitrification and N2O emission as well as N loss from acid sulphate soil.

  10. Characterization of an atmospheric double arc argon-nitrogen plasma source

    Science.gov (United States)

    Tu, X.; Chéron, B. G.; Yan, J. H.; Yu, L.; Cen, K. F.

    2008-05-01

    In the framework of studies devoted to hazardous waste destruction, an original dc double anode plasma torch has been designed and tested, which produces an elongated, weak fluctuation and reproducible plasma jet at atmospheric pressure. The arc instabilities and dynamic behavior of the double arc argon-nitrogen plasma jet are investigated through the oscillations of electrical signals by combined means of fast Fourier transform and Wigner distribution. In our experiment, the restrike mode is identified as the typical fluctuation behavior in an argon-nitrogen plasma jet. The Fourier spectra and Wigner distributions exhibit two characteristic frequencies of 150 Hz and 4.1 kHz, which reveals that the nature of fluctuations in the double arc argon-nitrogen plasma can be ascribed to the undulation of the power supply and both arc roots motion on the anode channels. In addition, the microscopic properties of the plasma jet inside and outside the arc chamber are investigated by means of optical emission spectroscopy, which yields excitation, electronic, rotational, and vibrational temperatures, as well as the electron number density. The results allow us to examine the validity criteria of a local thermodynamic equilibrium (LTE) state in the plasma arc. The measured electron densities are in good agreement with those calculated from the LTE model, which indicates that the atmospheric double arc argon-nitrogen plasma in the core region is close to the LTE state under our experimental conditions.

  11. Optical Methods For Transient Plasmas Studies By Multichannel TEA Nitrogen Laser

    Science.gov (United States)

    Ursu, Ioan; Popescu, Ion M.; Ivascu, M.; Baltog, I.; Mihut, L.; Zambreanu, V.; Zoita, V.

    1989-05-01

    A multichannel TEA nitrogen laser has been realized for some optical diagnostics. The following methods have been applied on the plasma focus device (PFD): interferometry, schlieren, shadowgraphy and a new combination of the last two. The background of these methods and some qualitative and quantitative results obtained in plasma focus (PF) studies are presented.

  12. Effects of herbicides on transformation of urea nitrogen in vegetable plantation soil%除草剂对尿素氮在土壤中转化的影响

    Institute of Scientific and Technical Information of China (English)

    丁洪; 郑祥洲; 雷俊杰; 张玉树; 陈静蕊; 李世清

    2012-01-01

    在实验室培养条件下研究除草剂草甘膦和丁草胺对尿素氮在菜地土壤中转化的影响.实验设对照、尿素、尿素+草甘膦和尿素+丁草胺4个处理,尿素氮用量为200 mg·kg-1(以干土计),除草剂用量为w(有效成分)-10 mg·kg-1(以干土计).结果表明,草甘膦和丁草胺对尿素氨化作用不产生抑制作用,甚至出现促进效果.2种除草剂在培养的前2d均显著抑制硝化作用,但到第4天时显著促进硝化作用(P<0.05).草甘膦对反硝化作用表现显著的抑制作用(P<0.05),而丁草胺对反硝化作用有极显著的促进作用(P<0.01);丁草胺+尿素、尿素、草甘膦+尿素处理的反硝化损失量分别占施氮量的16.90%、6.34%和3.66%.可见,除草剂对土壤氮素转化有一定影响,但不同除草剂对氮素各个转化途径的影响有明显差异,不同除草剂品种间影响程度也不同.%To assess the effects of herbicides on transformation of urea nitrogen in vegetable plantation soil, an incubation experiment was conducted under laboratory condition with 4 treatments including control, urea, urea+glyphosate and urea+butachlor, w(N)=200 mg·kg-1 by dry soil and inactive ingredient)=10 mg·kg-1 by dry soil were applied in urea and herbicide treatments respectively. The experimental results showed that glyphosate and butachlor had no negative impact on ammonification of urea or improved the ammonification activity; retarded the nitrifying rates of soil in 2 days in the beginning, but accelerated the rates at the 4th day significantly (P<0.05); Glyphosate inhibited denitrification (P<0.05), but butachlor promoted one (P<0.01). The nitrogen loss amounts by denitrification occupied 16.90%. 6.34% and 3.66% of urea nitrogen applied in urea+butachlor, urea and urea+glyphosate treatments, respectively. In conclusion, herbicides markedly affected nitrogen transformation in soil, but different kind of herbicides appeared different impacts on processes

  13. Modification of diamond-like carbon films by nitrogen incorporation via plasma immersion ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Flege, S., E-mail: flege@ca.tu-darmstadt.de [Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt (Germany); Hatada, R.; Hoefling, M.; Hanauer, A.; Abel, A. [Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt (Germany); Baba, K. [Industrial Technology Center of Nagasaki, Applied Technology Division, Omura, Nagasaki 856-0026 (Japan); Ensinger, W. [Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Str. 2, 64287 Darmstadt (Germany)

    2015-12-15

    Highlights: • Nitrogen containing diamond-like carbon films were prepared by a plasma ignited by a high voltage. • Variation of preparation method (N{sub 2} implantation, N{sub 2} and C{sub 2}H{sub 4} co-deposition). • Maximum nitrogen content similar for co-deposition and implantation. • Electrical resistivity decreases for small nitrogen contents, increases again for higher contents. - Abstract: The addition of nitrogen to diamond-like carbon films affects properties such as the inner stress of the film, the conductivity, biocompatibility and wettability. The nitrogen content is limited, though, and the maximum concentration depends on the preparation method. Here, plasma immersion ion implantation was used for the deposition of the films, without the use of a separate plasma source, i.e. the plasma was generated by a high voltage applied to the samples. The plasma gas consisted of a mixture of C{sub 2}H{sub 4} and N{sub 2}, the substrates were silicon and glass. By changing the experimental parameters (high voltage, pulse length and repetition rate and gas flow ratio) layers with different N content were prepared. Additionally, some samples were prepared using a DC voltage. The nitrogen content and bonding was investigated with SIMS, AES, XPS, FTIR and Raman spectroscopy. Their influence on the electrical resistivity of the films was investigated. Depending on the preparation conditions different nitrogen contents were realized with maximum contents around 11 at.%. Those values were compared with the nitrogen concentration that can be achieved by implantation of nitrogen into a DLC film.

  14. Function Study Of The Blood Urea Nitrogen In Monitoring Sports Traning%血尿素氮在运动训练监控中的作用简述

    Institute of Scientific and Technical Information of China (English)

    徐起麟

    2014-01-01

    This study briefly introduced the blood urea nitrogen (BUN) changes in athletic training, fatigue recovery, weight control and sports nutrition. Analysed the causes of increased blood urea nitrogen, and pointed out that blood urea nitrogen is one of the most sensitive indicators of assessment training load in the practice of sports training and athletic physiological and biochemical studies which can be used for training load monitoring.%本研究简述了血尿素氮(BUN)在运动训练、疲劳恢复、控体重和运动营养等中的变化情况。分析了血尿素氮升高的原因,并指出在运动训练实践和运动生理生化研究中,血尿素氮是评定训练负荷最敏感的指标之一,可以用来进行训练负荷的监控。

  15. Síntese de proteína microbiana e concentrações de uréia em vacas alimentadas com dietas à base de palma forrageira e diferentes volumosos Microbial protein synthesis and urea nitrogen concentrations in lactating dairy cows fed spineless cactus and different forages based diets

    Directory of Open Access Journals (Sweden)

    Marcelo de Andrade Ferreira

    2009-01-01

    Full Text Available Cinco vacas da raça Holandesa foram distribuídas em um quadrado latino 5 × 5 com o objetivo de estimar a produção de proteína microbiana utilizando-se a excreção total de derivados de purinas (DP, por meio de coletas spot de urina, e as concentrações de nitrogênio (N-uréia no plasma, no leite e na urina. As cinco dietas foram formuladas com diversos volumosos (bagaço de cana-de-açúcar; feno de capim-tifton; feno de capim-elefante; silagem de sorgo; e uma mistura de silagem de sorgo + bagaço de cana associados à palma forrageira. As concentrações de uréia (10,98 mg/dL e N-uréia (5,11 mg/dL no leite não foram afetadas pelos volumosos, assim como as concentrações plasmáticas de uréia (28,10 mg/dL e N-uréia (13,09 mg/dL. As excreções urinárias de uréia, N-uréia, alantoína e derivados de purina, purinas absorvidas, a síntese de N-microbiano e as concentrações de alantoína no leite não foram alteradas. Os volumosos utilizados podem ser associados a palma forrageira na alimentação de vacas Holandesas, pois não alteram a produção de proteína microbiana.Five Holstein cows were allotted to a 5 × 5 Latin square design with the objective of evaluating the microbial protein production, using the total excretion of purine derivatives (PD, obtained from spot urine collection, plasma and milk urea and nitrogen (N-urea. The five treatments contained different forage sources: sugar cane bagasse (CB, tifton hay (TH, elephant grass hay (EH, sorghum silage (SS and a mixture of sugar cane bagasse + sorghum silage (CBSS. The milk urea (10.98 mg/dL and N-urea (5.11 mg/dL concentrations were not influenced by the forage sources, such as plasma urea (28.10 mg/dL and N-urea (13.09 mg/dL concentrations. The urinary urea, N-urea, allantoin and PD excretions, the absorbed purine, N-microbial synthesis and milk allantoin concentration remained unchanged. The different forage sources in association with forage cactus did not change

  16. Nitrogen mass transfer models for plasma-based low-energy ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Bocong; Wang, Kesheng; Zhang, Zhipeng; Che, Honglong; Lei, Mingkai, E-mail: mklei@dlut.edu.cn [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2015-03-15

    The nitrogen mass transfer process in plasma-based low-energy ion implantation (PBLEII) is theoretically and experimentally studied in order to explore the process mechanism of PBLEII and therefore to optimize the apparatus design and the process conditions. An electron cyclotron resonance (ECR) microwave discharge generates the nitrogen plasma with a high density of 10{sup 11}–10{sup 12} ions/cm{sup 3}, which diffuses downstream to the process chamber along the divergent magnetic field. The nitrogen ions in the plasma implant into the surface and transport to the matrix of an austenitic stainless steel under the low negative pulsed bias of −2 kV at a process temperature of 400 °C. A global plasma model is used to simulate the ECR microwave plasma discharge for a range of working pressures and microwave powers. The fluid models are adopted to calculate the plasma downstream diffusion, the sheath expansion and the low-energy ion implantation on the surface. A nonlinear kinetic discrete model is established to describe the nitrogen transport in the austenitic stainless steel and the results are compared with the experimental measurements. Under an average implantation current density of 0.3–0.6 mA/cm{sup 2}, the surface nitrogen concentration in the range from 18.5 to 29 at. % is a critical factor for the nitrogen transport in the AISI 304 austenitic stainless steel by PBLEII, which accelerates the implanted nitrogen diffusion inward up to 6–12 μm during a nitriding time of 4 h.

  17. Numerical study on the characteristics of nitrogen discharge at high pressure with induced plasma

    Institute of Scientific and Technical Information of China (English)

    Wang Yi-Nan; Liu Yue; Zheng Shu; Lin Guo-Qiang

    2012-01-01

    Based on the fluid theory of plasma,a model is built to study the characteristics of nitrogen discharge at high pressure with induced argon plasma.In the model,species such as electrons,N2+,N4+,Ar+,and two metastable states (N2(A3 ∑ u+),N2(a1 ∑ u-)) are taken into account.The model includes the particle continuity equation,the electron energy balance equation,and Poisson(柤)equation.The model is solved with a finite difference method.The numerical results are obtained and used to investigate the effect of time taken to add nitrogen gas and initially-induced argon plasma pressure.It is found that lower speeds of adding the nitrogen gas and varying the gas pressure can induce higher plasma density,and inversely lower electron temperature.At high-pressure discharge,the electron density increases when the proportion of nitrogen component is below 40%,while the electron density will keep constant as the nitrogen component further increases.It is also shown that with the increase of initially-induced argon plasma pressure,the density of charged particles increases,and the electron temperature as well as the electric field decreases.

  18. Surface-nitriding treatment of steels using microwave-induced nitrogen plasma at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Shigeo, E-mail: s.sato@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Arai, Yuuki [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Yamashita, Noboru; Kojyo, Atsushi; Kodama, Kenji [Rigaku Corporation, Takatsuki, Osaka 569-1146 (Japan); Ohtsu, Naofumi [Kitami Institute of Technology, Kitami, Hokkaido 090-8507 (Japan); Okamoto, Yukio [Research Institute of Industrial Technology, Toyo University, Kawagoe 350-8585 (Japan); Wagatsuma, Kazuaki [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2012-07-15

    A rapid surface-nitriding system using microwave-induced nitrogen plasma at atmospheric pressure was developed for modifying iron and steel surfaces. Since the conventional plasma nitriding technique requires a low-pressure atmosphere in the treatment chamber, the population of excited nitrogen molecules in the plasma is limited. Accordingly, several hours are required for nitriding treatment. By contrast, the developed nitriding system can use atmospheric-pressure plasma through application of the Okamoto cavity for excitation of nitrogen plasma. The high population of excited nitrogen molecules induced by the atmospheric-pressure plasma allowed the formation of a nitriding layer that was several micrometers thick within 1 min and produced an expanded austenite iron phase with a high nitrogen concentration close to the solubility limit on the iron substrate. In addition, the nitriding treatment on high-chromium steel was performed by introducing a reducing gas such as NH{sub 3} and H{sub 2} into the treatment chamber. While the nitriding reaction did not proceed in a simple N{sub 2} atmosphere due to surface oxidation, the surface reduction induced by the NH{sub 3} or H{sub 2} gas promoted the nitriding reaction at the surface. These nitriding phenomena characteristics of the atmospheric-pressure plasma are discussed in this paper based on the effects of the specimen temperature and plasma atmosphere on the thickness, the chemical states, and the nitride compounds of the nitrided layer as investigated by X-ray diffraction, glow-discharge optical emission spectroscopy, and X-ray photoelectron spectroscopy.

  19. Energy distributions of electrons in electron beam produced nitrogen plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Suhre, D.R.

    1976-01-01

    A theory was developed which predicts the equilibrium electron energy distributions resulting from the injection of an electron beam into molecular nitrogen. The results were highly non-Maxwellian with a depletion region existing near 2.5 eV. Using these distributions, fractional power transfers to various excitation processes were calculated. The theory was verified experimentally by using Langmuir probes to measure the electron energy distributions produced by a beam generated by a cold cathode discharge in low pressure nitrogen. The distributions were measured in absolute units and compared directly with theory. All of the major features of the theory were found to be present in the measurements.

  20. Association between an increase in blood urea nitrogen at 24 hours and worse outcomes in acute nonvariceal upper GI bleeding.

    Science.gov (United States)

    Kumar, Navin L; Claggett, Brian L; Cohen, Aaron J; Nayor, Jennifer; Saltzman, John R

    2017-04-02

    An increase in blood urea nitrogen (BUN) at 24 hours is a solitary and significant predictor of mortality in patients with acute pancreatitis, which may predict worse outcomes in the similarly resuscitation-requiring condition of acute nonvariceal upper GI bleeding (UGIB). The aim of our study was to assess whether an increase in BUN at 24 hours is predictive of worse clinical outcomes in acute nonvariceal UGIB. A retrospective cohort study including patients admitted to an academic hospital from 2004 to 2014 was conducted. An increase in BUN was defined as an increase in BUN at 24 hours of hospitalization compared with BUN at presentation. The primary outcome was a composite of inpatient death, inpatient rebleeding, need for surgical or radiologic intervention, or endoscopic reintervention. Associations between BUN change and outcomes were assessed via the Pearson χ(2) test and the Fisher exact test and via logistic regression for adjusted analyses. There were 357 patients included in the analysis with a mean age of 64 years; 54% were men. The mean change in BUN was -10.1 mg/dL (standard deviation, 12.7 mg/dL). Patients with an increased BUN (n = 37 [10%]) were significantly more likely to experience the composite outcome (22% vs 9%, P = .014), including an increased risk of inpatient death (8% vs 1%, P = .004), compared with patients with a decreased or unchanged BUN (n = 320 [90%]). In a logistic regression model adjusting for the AIMS65 score, an increase in BUN was independently associated with an increased risk for the composite outcome (odds ratio, 2.75; P = .026). Increasing BUN at 24 hours likely reflects under resuscitation and is a predictor of worse outcomes in patients with acute nonvariceal UGIB. Copyright © 2017 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  1. The risk of death associated with proteinuria in heart failure is restricted to patients with an elevated blood urea nitrogen to creatinine ratio.

    Science.gov (United States)

    Brisco, Meredith A; Zile, Michael R; Ter Maaten, Jozine M; Hanberg, Jennifer S; Wilson, F Perry; Parikh, Chirag; Testani, Jeffrey M

    2016-07-15

    Renal dysfunction (RD) is associated with reduced survival in HF; however, not all RD is mechanistically or prognostically equivalent. Notably, RD associated with "pre-renal" physiology, as identified by an elevated blood urea nitrogen to creatinine ratio (BUN/Cr), identifies a particularly high risk RD phenotype. Proteinuria, another domain of renal dysfunction, has also been associated with adverse events. Given that several different mechanisms can cause proteinuria, we sought to investigate whether the mechanism underlying proteinuria also affects survival in HF. Subjects in the Studies of Left Ventricular Dysfunction (SOLVD) trial with proteinuria assessed at baseline were studied (n=6439). All survival models were adjusted for baseline characteristics and estimated glomerular filtration rate (eGFR). Proteinuria (trace or 1+) was present in 26% and associated with increased mortality (HR=1.2; 95% CI, 1.1-1.3, p=0.006). Proteinuria >1+ was less common (2.5%) but demonstrated a stronger relationship with mortality (HR=1.9; 95% CI, 1.5-2.5, pproteinuria (HR=1.3; 95% CI, 1.1-1.5, p=0.008) and >1+ proteinuria (HR=2.3; 95% CI, 1.7-3.3, pproteinuria (HR=0.95; 95% CI, 0.77-1.2, p=0.63, p interaction=0.015) and >1+ proteinuria (HR=1.3; 95% CI, 0.79-2.2, p=0.29, p interaction=0.036) were not associated with worsened survival. Analogous to a reduced eGFR, the mechanism underlying proteinuria in HF may be important in determining the associated survival disadvantage. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Effects of supplementary urea-minerals lick block on the kinetics of fibre digestion, nutrient digestibility and nitrogen utilization of low quality roughages

    Institute of Scientific and Technical Information of China (English)

    WU Yue-ming; HU Wei-lian; LIU Jian-xin

    2005-01-01

    Three yearling lambs with a rumen cannula were used to investigate the effects of supplementation with an urea-minerals lick block (ULB) on the kinetics ofruminal fibre digestion, nutrient digestibility and nitrogen (N) utilization of rice straw (RS), ammonia bicarbonate (AB)-treated RS (ABRS) and hay prepared from natural pasture. The digestibility of dry matter and organic matter of RS increased by 13.1% and 12.7% (P<0.05) when the diet was supplemented with ULB, and approached to that of ABRS, indicating that the effect of ULB on digestibility of RS is similar to that of AB treatment. The digestibility of ABRS was slightly improved by the ULB feeding. Nitrogen retention was highest in lambs fed on ABRS alone, followed by hay with ULB, and was lowest in animals fed on RS with ULB. However, both the amount and proportion of N retention to N intake were enhanced by ULB supplementation to lambs fed on hay. The proportion of N retained to N digested decreased due to ULB supplementation to lambs fed on RS or ABRS. Supplementing ULB did not greatly influence the rumen degradation of either dry matter or crude protein in each of the three diets. RS and hay had similar values in the potential extent of digestion (PED) and digestion rate of PED (kd) of fibrous materials, but the discrete lag time for RS was lower than that for hay. The AB treatment significantly increased the PED (P<0.05) and kd (P<0.05) of RS. Neither the PED nor kd for RS and ABRS was influenced by ULB supplementation, but the kd for hay significantly increased due to ULB. The lag time for hay was also shortened by the ULB feeding. The ULB improved the digestion of fibre in the rumen of lambs fed on low quality roughage. It is inferred that while ULB is effective in increasing nutrient digestibility of low quality roughages by improving ruminal fibre digestion. A synchronized supply of N and energy to rumen microbes should be considered to improve the efficiency of N utilization when the basal

  3. Productivity and efficiency of nitrogen fertilization in maize under different levels of urea and NBPT-treated urea Produtividade e eficiência da adubação nitrogenada em milho sob doses de uréia comum e com NBPT

    Directory of Open Access Journals (Sweden)

    Douglas Ramos Guelfi Silva

    2011-06-01

    Full Text Available The management of nitrogen fertilization is complex due to the various transformations of the nitrogen that occur in the soil-plant-atmosphere system, reducing the efficiency of the fertilization, productivity and the profit margin of the maize production areas. This study aimed to evaluate the effect of different levels of common urea and urea treat with NBPT [N-(n-butyl thiophosphoric triamide] on the productivity and efficiency of the nitrogen fertilization in maize, correlated with simple economic analysis. The design of the field experiment was in randomized complete blocks with six repetitions, in a 2 x 4 factorial outline, made up of by two sources of nitrogen (urea and NBPT-treated urea and four levels of nitrogen as top dressing (60, 120, 180 and 240 kg ha-1. The sources and applied nitrogen levels influenced the productivity and the leaf and grain nitrogen contents, while the production components (size and diameter of the ear, and percentage of straw and cob were not altered. The agronomic efficiency of the nitrogen fertilization decreased with the increase of the applied nitrogen levels. The highest gross profit margin in the maize culture is obtained with 180 kg ha-1 of nitrogen supplied in the NBPT-treated urea.O manejo da adubação nitrogenada é complexo em razão das diversas transformações do nitrogênio que ocorrem no sistema solo-planta-atmosfera, diminuindo a eficiência da adubação, produtividade e a margem de lucro das áreas de produção de milho. Neste trabalho, objetivou-se avaliar o efeito de diferentes doses de uréia comum e com NBPT [N-(n-butyl thiophosphoric triamide] na produtividade e eficiência da adubação nitrogenada na cultura do milho, correlacionado com análise econômica simples. O delineamento experimental foi em blocos completos casualizados com seis repetições, em esquema fatorial 2 x 4, constituídos por duas fontes de N (uréia comum e uréia tratada com NBPT e quatro doses de nitrog

  4. Effects of urea-formaldehyde fertilizer on yield of Chinese cabbage and its nitrogen use efficiency%脲甲醛肥料对小白菜产量和氮肥利用率的影响

    Institute of Scientific and Technical Information of China (English)

    黄丽娜; 樊小林

    2012-01-01

    【目的】研究脲甲醛肥料的产量效应和氮肥利用率,为叶菜专用脲甲醛肥料的研制和施用提供理论依据。【方法】以小白菜为供试蔬菜,以不施氮肥为对照(CK),以常规氮肥尿素、脲甲醛肥料及两者混合氮肥(尿素与脲甲醛肥料氮素质量比为1∶1)为供试肥料,开展第1季施肥、第2季不施肥的连续两季田间微小区栽培试验,研究脲甲醛肥料对小白菜产量及氮肥利用率的影响。【结果】每季各氮肥处理小白菜产量均存在明显差异,且均显著高于CK。小白菜第1季产量以尿素+脲甲醛肥料处理最高,为50 678kg/hm2;第2季产量以脲甲醛肥料处理最高,为28 051kg/hm2;而以上2个处理的两季小白菜总产量无显著差异,但均显著高于尿素处理。不同处理每季小白菜氮吸收量和氮肥利用率存在明显差异,第1季尿素+脲甲醛肥料处理小白菜的氮吸收量和氮肥利用率最高,分别为202.73mg/株及24.94%;第2季脲甲醛肥料处理最高,分别为173.72mg/株及21.88%,而以上2个处理的氮吸收总量、氮肥累积利用率无显著差异,且均显著高于尿素处理,表明脲甲醛单独施用或与尿素混合施用具有明显的后效,可显著增加氮肥累积利用率。【结论】脲甲醛肥料与尿素混合施用既能保障第1季小白菜产量,又可降低缓释肥料成本,明显提高氮肥利用率。%【Objective】 The effects of urea-formaldehyde fertilizer on the yield and nitrogen use efficiency(NUE) of vegetables were studied to promote the development and application of urea-formaldehyde fertilizer special for leafy vegetables.【Method】 Three nitrogen fertilizers applied in the experiment were urea(U),urea-formaldehyde fertilize(UF),and urea blended with urea-formaldehyde fertilizer(U+UF).The study covered two continuous cropping seasons of Chinese cabbage in micro-plot field.All of the three fertilizers were applied in the first growing

  5. Nitrogen plasma-treated multilayer graphene-based field effect transistor fabrication and electronic characteristics

    Science.gov (United States)

    Su, Wei-Jhih; Chang, Hsuan-Chen; Honda, Shin-ichi; Lin, Pao-Hung; Huang, Ying-Sheng; Lee, Kuei-Yi

    2017-08-01

    Chemical doping with hetero-atoms is an effective method used to change the characteristics of materials. Nitrogen doping technology plays a critical role in regulating the electronic properties of graphene. Nitrogen plasma treatment was used in this work to dope nitrogen atoms to modulate multilayer graphene electrical properties. The measured I-V multilayer graphene-base field-effect transistor characteristics (GFETs) showed a V-shaped transfer curve with the hole and electron region separated from the measured current-voltage (I-V) minimum. GFETs fabricated with multilayer graphene from chemical vapor deposition (CVD) exhibited p-type behavior because of oxygen adsorption. After using different nitrogen plasma treatment times, the minimum in I-V characteristic shifted into the negative gate voltage region with increased nitrogen concentration and the GFET channel became an n-type semiconductor. GFETs could be easily fabricated using this method with potential for various applications. The GFET transfer characteristics could be tuned precisely by adjusting the nitrogen plasma treatment time.

  6. Synthesis and characterization of well-aligned carbon nitrogen nanotubes by microwave plasma chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    马旭村; 徐贵昌; 王恩哥

    2000-01-01

    Well-aligned carbon nitrogen nanotube films have been synthesized successfully on meso-porous silica substrates by microwave plasma chemical vapor deposition (MWPCVD) method. Studies on their morphology, structure, and composition by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX), respectively, indicate that these nanotubes consist of linearly polymerized carbon nitrogen nanobells, and the nitrogen atoms have been doped into carbon netweork to form a new structure C1-xNx( x = 0.16±0.01). X-ray photoelectron spectroscopy (XPS) results of the samples further demonstrate that carbon bonds cova-lently with nitrogen in all the carbon nitrogen nanotube films.

  7. Properties of Laser Produced TMAE Plasma Admixed with Air Constituents, Nitrogen and Noble Gases

    Science.gov (United States)

    Ding, Guowen; Scharer, John; Kelly, Kurt

    1999-10-01

    A high initial density (> 10^13 cm-3) and a large volume (hundreds of cm^3) plasma is created by a 193 nm laser ionization of an organic molecule, tetrakis(dimethyl-amino)ethylene(TMAE). The properties of this plasma mixed with nitrogen and noble gases are studied. Fast probe measurements which include a detailed considerations of probe structure, probe surface cleaning, shielding, probe perturbation, frequency response, temporal and spatial resolutions, dummy probe corrections and noise analysis will be described. Electron densities obtained by this method are independent on the ion species mixture. A plasma emission diagnostic is used to estimate plasma densities for the higher admixture pressures. Electron density and temperature vs. time for various TMAE, nitrogen and noble gas pressures and laser power will be presented. The role of super-excited and metastable states in the decay process will also be discussed.

  8. A review of factors influencing milk urea concentration and its relationship with urinary urea excretion in lactating dairy cattle

    NARCIS (Netherlands)

    Spek, J.W.; Dijkstra, J.; Duinkerken, van G.; Bannink, A.

    2013-01-01

    Milk urea nitrogen (MUN) concentration in dairy cows may serve as an on-farm indicator to guide nutritional strategies and to help reduce emissions of nitrogen (N) to the environment. Excretion of urinary urea nitrogen (UUN) is positively related to MUN, but the relationship is highly variable. The

  9. Simultaneous determination of glucose, triglycerides, urea, cholesterol, albumin and total protein in human plasma by Fourier transform infrared spectroscopy: direct clinical biochemistry without reagents.

    Science.gov (United States)

    Jessen, Torben E; Höskuldsson, Agnar T; Bjerrum, Poul J; Verder, Henrik; Sørensen, Lars; Bratholm, Palle S; Christensen, Bo; Jensen, Lene S; Jensen, Maria A B

    2014-09-01

    Direct measurement of chemical constituents in complex biologic matrices without the use of analyte specific reagents could be a step forward toward the simplification of clinical biochemistry. Problems related to reagents such as production errors, improper handling, and lot-to-lot variations would be eliminated as well as errors occurring during assay execution. We describe and validate a reagent free method for direct measurement of six analytes in human plasma based on Fourier-transform infrared spectroscopy (FTIR). Blood plasma is analyzed without any sample preparation. FTIR spectrum of the raw plasma is recorded in a sampling cuvette specially designed for measurement of aqueous solutions. For each analyte, a mathematical calibration process is performed by a stepwise selection of wavelengths giving the optimal least-squares correlation between the measured FTIR signal and the analyte concentration measured by conventional clinical reference methods. The developed calibration algorithms are subsequently evaluated for their capability to predict the concentration of the six analytes in blinded patient samples. The correlation between the six FTIR methods and corresponding reference methods were 0.87triglycerides, urea, cholesterol, albumin and total protein in human plasma. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  10. DNA damage in oral cancer cells induced by nitrogen atmospheric pressure plasma jets

    Science.gov (United States)

    Han, Xu; Klas, Matej; Liu, Yueying; Stack, M. Sharon; Ptasinska, Sylwia

    2013-09-01

    The nitrogen atmospheric pressure plasma jet (APPJ) has been shown to effectively induce DNA double strand breaks in SCC-25 oral cancer cells. The APPJ source constructed in our laboratory consists of two external electrodes wrapping around a quartz tube and nitrogen as a feed gas and operates based on dielectric barrier gas discharge. Generally, it is more challenging to ignite plasma in N2 atmosphere than in noble gases. However, this design provides additional advantages such as lower costs compared to the noble gases for future clinical operation. Different parameters of the APPJ configuration were tested in order to determine radiation dosage. To explore the effects of delayed damage and cell self-repairing, various incubation times of cells after plasma treatment were also performed. Reactive species generated in plasma jet and in liquid environment are essential to be identified and quantified, with the aim of unfolding the mystery of detailed mechanisms for plasma-induced cell apoptosis. Moreover, from the comparison of plasma treatment effect on normal oral cells OKF6T, an insight to the selectivity for cancer treatment by APPJ can be explored. All of these studies are critical to better understand the damage responses of normal and abnormal cellular systems to plasma radiation, which are useful for the development of advanced plasma therapy for cancer treatment at a later stage.

  11. Preparation of Nitrogen-Doped TiO2 Photocatalyst with Urea as Nitrogen Source%尿素为氮源制备氮掺杂二氧化钛光催化剂

    Institute of Scientific and Technical Information of China (English)

    占俐琳; 梁华银; 左建林

    2013-01-01

    以Ti(SO4)2为前驱物,尿素为沉淀剂和掺杂剂,采用水热法结合固相反应法制得了锐钛矿相掺氮纳米TiO2纳米粉体.采用XRD对制备的掺氮氧化钛结构进行了表征,以亚甲基蓝为模拟污染物,考察了不同煅烧温度制备的光催化剂在可见光照射下的光催化性能.结果表明,煅烧温度高于160℃时氮可掺进TiO2晶体中,且温度越高,掺氮量越高;煅烧温度为200℃时,氮掺杂TiO2粉体可见光催化活性最强,在波长不低于400nm的可见光作用下,对亚甲基蓝的4h降解率达62.5%.%N-doped TiO2 with anatase crystal structure was prepared by using hydrothermal and solid state reaction,using Ti (SO4)2 as a precursor,urea as a precipitator and dopant of nitrogen source.The crystal structure of the photocatalyst was characterized by XRD.The photocatalytic degradation of methylence blue was used as model reaction to evaluate the visible light activity of nitrogen-doped TiO2 samples prepared at different calcining temperatures.The results indicate that the nitrogen atom was doped into TiO2 when the calcining temperature was above 160℃,and the doped content of N increased slightly with the calcining temperature increasing.When the calcining temperature was 200℃,the sample had the best photocatalytic activity for the degradation of methylence blue under visible-light wavelength above 400 nm,and the photocatalytic results showed that 62.5% methylence blue was degraded after 4 h reaction.

  12. Differential protein abundance and function of UT-B urea transporters in human colon.

    Science.gov (United States)

    Collins, D; Winter, D C; Hogan, A M; Schirmer, L; Baird, A W; Stewart, G S

    2010-03-01

    Facilitative UT-B urea transporters enable the passage of urea across cell membranes. Gastrointestinal urea transporters are thought to play a significant role in the urea nitrogen salvaging process that occurs between mammalian hosts and their gut bacteria. This study investigated the expression of UT-B urea transporters in different segments of human colon. Immunoblot analysis showed that human colon expressed a 35-kDa glycosylated UT-B protein in the colonic mucosa. The 35-kDa UT-B transporter was predominantly located in plasma membrane-enriched samples (P UT-B transporters were located throughout colonocytes situated in the upper portion of the colonic crypts. Bidirectional trans-epithelial urea transport was significantly greater in the ascending colon than the descending colon (P UT-B protein in different sections of the human colon, strongly correlating to regions that contain the largest populations of intestinal bacteria. This study suggests an important role for UT-B urea transporters in maintaining the symbiotic relationship between humans and their gut bacteria.

  13. Traits of Urea Nitrogen Release from Starch Acetate Coated Urea and amended with biological inhibitors in meadow brown soil%醋酸酯淀粉及与抑制剂结合包膜尿素在棕壤中尿素溶出特征

    Institute of Scientific and Technical Information of China (English)

    李东坡; 武志杰; 梁成华

    2011-01-01

    在室内恒温培养条件下,以普通大颗粒尿素为对照,研究4种醋酸酯淀粉(SA)包膜及与生化抑制剂结合尿素肥料在草甸棕壤中尿素态氮溶出特征,以确定不同种SA包膜尿素在土壤中缓/控释效果及释放特征。研究表明,4种SA包膜尿素在土壤中尿素累积溶出量在28 d后达到最大值,接近100%,SA+UTRA、SA+DCD+UTRA、SA+NBPT+UTRA和SA+DCD+NBPT+UREA分别在12、16、12和16 d养分累积溶出量超过80%,是水中释放期的2倍左右,SA+UREA时段平均溶出率最高峰值出现在0~4 d,达到9.11%d-1,另3种包膜肥料均出现在5~8 d,为8.57%d-1~9.97%d-1。SA与DCD或NBPT结合包膜尿素对控制尿素释放作用效果十分显著,SA与DCD及NBPT结合型包膜尿素肥料对抑制尿素释放作用最强。%Using a conventional granular urea as control,the release characteristics of four kinds of urea nitrogen,which amended with biological inhibitors and/or coated by acetate starch,were examined under constant temperature incubation with Meadow Brown Soil in laboratory.The result indicated that the maximum accumulative urea nitrogen release rates of four starch acetate coated urea fertilizers were all observed after 28 days,and their values were nearly 100% of urea-N.The nutrient release amounts of SA + UTRA,SA + DCD + UTRA,SA + NBPT + UTRA and SA + DCD + NBPT + UREA were over 80% separately on the 12 d,16 d,12 d and 16 d,which were almost two times of release time in water.The maximum of average release rates per unit time from urea coated by starch acetate was up to 9.11 %/d between 0 and 4 d,and those of the other three coated fertilizers were between 8.57% d-1 and 9.97% d-1 from 5 to 8 d.The urea amended with DCD or NBPT coated by acetate starch showed a significantly slow release,and urea amended with DCD,NBPT and coated by starch acetate had the most significant slow-release effect.

  14. Physiological and transcriptional response of Bacillus cereus treated with low-temperature nitrogen gas plasma

    NARCIS (Netherlands)

    Mols, J.M.; Mastwijk, H.C.; Nierop Groot, M.N.; Abee, T.

    2013-01-01

    Aims - This study was conducted to investigate the inactivation kinetics of Bacillus cereus vegetative cells upon exposure to low-temperature nitrogen gas plasma and to reveal the mode of inactivation by transcriptome profiling. Methods and Results - Exponentially growing B. cereus cells were

  15. Molecular nitrogen acceptors in ZnO nanowires induced by nitrogen plasma annealing

    Science.gov (United States)

    Ton-That, C.; Zhu, L.; Lockrey, M. N.; Phillips, M. R.; Cowie, B. C. C.; Tadich, A.; Thomsen, L.; Khachadorian, S.; Schlichting, S.; Jankowski, N.; Hoffmann, A.

    2015-07-01

    X-ray absorption near-edge spectroscopy, photoluminescence, cathodoluminescence, and Raman spectroscopy have been used to investigate the chemical states of nitrogen dopants in ZnO nanowires. It is found that nitrogen exists in multiple states: NO,NZn, and loosely bound N2 molecule. The results establish a direct link between a donor-acceptor pair emission at 3.232 eV and the concentration of loosely bound N2. This work confirms that N2 at Zn site is a potential candidate for producing a shallow acceptor state in N-doped ZnO as theoretically predicted by Lambrecht and Boonchun [Phys. Rev. B 87, 195207 (2013), 10.1103/PhysRevB.87.195207]. Additionally, shallow acceptor states arising from NO complexes have been ruled out in this paper.

  16. Modeling of Nitrogen Penetration in Medical Grade CoCrMo Alloy during Plasma Nitriding

    Directory of Open Access Journals (Sweden)

    Arvaidas GALDIKAS

    2014-04-01

    Full Text Available For analysis of plasma nitriding process and nitrogen penetration into CoCrMo alloy the trapping-detrapping model is applied. This model is commonly used for analysis of stainless steel nitriding, however, in this work it is shown that the same nitrogen penetration mechanism takes place in CoCrMo alloys. From the fitting of experimental curves, taken from literature, it is found by the proposed model that diffusion coefficient depends on nitrogen concentration according to Einstein-Smoluchowski relation D µ 1/CN. The diffusion coefficients for 400oC temperature nitriding of in CoCrMo are calculated. The shape of nitrogen depth profile curves are analyzed showing influence of different parameters such as detrapping activation energy, chromium concentration, etc.DOI: http://dx.doi.org/10.5755/j01.ms.20.1.3458

  17. Modeling of Nitrogen Penetration in Medical Grade CoCrMo Alloy during Plasma Nitriding

    Directory of Open Access Journals (Sweden)

    Arvaidas GALDIKAS

    2014-04-01

    Full Text Available For analysis of plasma nitriding process and nitrogen penetration into CoCrMo alloy the trapping-detrapping model is applied. This model is commonly used for analysis of stainless steel nitriding, however, in this work it is shown that the same nitrogen penetration mechanism takes place in CoCrMo alloys. From the fitting of experimental curves, taken from literature, it is found by the proposed model that diffusion coefficient depends on nitrogen concentration according to Einstein-Smoluchowski relation D µ 1/CN. The diffusion coefficients for 400oC temperature nitriding of in CoCrMo are calculated. The shape of nitrogen depth profile curves are analyzed showing influence of different parameters such as detrapping activation energy, chromium concentration, etc.DOI: http://dx.doi.org/10.5755/j01.ms.20.1.3458

  18. Rotational and Vibrational Temperatures of Atmospheric Double Arc Argon-Nitrogen Plasma

    Institute of Scientific and Technical Information of China (English)

    YAN Jian-Hua; TU Xin; MA Zeng-Yi; CEN Ke-Fa; B.G.Chéron

    2007-01-01

    The spectroscopic technique is employed to study the emission of atmospheric argon-nitrogen plasma jet generated by an original dc double anode plasma torch. The molecular bands of the N(+2) first negative system are observed at the torch exit and chosen to evaluate the rotational and vibrational temperatures in comparison with the simulated spectra. The excitation temperature (Texc≈9600 K) is determined from the Boltzmann plot method. The results show that the rotational, vibrational, electron and kinetic temperatures are in good agreement with one another, which indicates that the core region of atmospheric double arc argon-nitrogen plasma jet at the torch exit is close to the local thermodynamic equilibrium state under our experimental conditions.

  19. Effects of Controlled Release Urea on Wheat Yield and Nitrogen Utilization Efficiency Under Different Applied Conditions%控释尿素不同施用条件下冬小麦产量和氮素利用效应

    Institute of Scientific and Technical Information of China (English)

    夏伟光; 武际; 高凤梅; 王允青; 郭熙盛

    2014-01-01

    The field trial was conducted to study the effects of different nitrogen fertilizer applications on winter wheat yield, nitrogen utiliza-tion efficiency and economic benefit. 7 treatments were designed as CK(no nitrogen fertilizer applied), 100%PU10/0( conventional urea ap-plied before sowing, N rate was 240 kg·hm-2), 100%PU6/4( conventional urea applied before sowing and at jointing with the ratio of 6:4, N rate was 240 kg·hm-2), 80%PU6/4 (conventional urea applied before sowing and at jointing with the ratio of 6:4, N rate was 192 kg·hm-2), 100%CRU(resin coated controlled release urea applied before sowing , N rate was 240 kg·hm-2), 80%CRU( resin coated controlled release urea applied before sowing , N rate was 192 kg·hm-2), and 40%CRU+40%PU(resin coated controlled release urea and conventional urea ap-plied before sowing , N rate was 192 kg·hm-2). The results showed that no matter on the efficiency of yield or that of nitrogen, resin coated controlled-release urea(CRU)was better when compared with conventional urea(PU). Especially, the combined application treatment (40%CRU+40%PU)was the best with achieving the highest wheat yield of 7 709 kg·hm-2, the highest N fertilizer utilization efficiency of 36.44%and the maximum net income of 15 946 yuan·hm-2. And it could not only increase winter wheat yield with reducing the nitrogen fer-tilizer application, but also improve N fertilizer utilization efficiency and owe the highest ratio of output to input. Therefore, the combined ap-plication of the resin coated controlled-release urea and conventional urea (40%CRU+40%PU)was the optimal nitrogen fertilizer treatment under the conditions of this experiment.%采用田间试验方法研究了控释尿素不同施用条件对冬小麦产量、氮素利用和经济效益的影响。试验共设7个处理,即CK (空白处理,不施氮肥)、100%PU10/0(普通尿素全量基施,N 240 kg·hm-2)、100%PU6/4(60%的普通尿素基施、40%的普通

  20. 包膜尿素氮素溶出对油菜生长及产量的影响%Effect of Nitrogen Solubility of Coated Urea on the Growth and Yield of Rape

    Institute of Scientific and Technical Information of China (English)

    张玉玲; 虞娜; 邹洪涛; 张玉龙; 陈温福; 剛本昌広

    2011-01-01

    通过肥料埋藏试验及盆栽试验方法,研究了LP30日型和LP70日型包膜尿素氮素溶出对油菜生长及产量的影响。研究表明:一级反应动力学模型可很好地描述LP30日型和LP70日型包膜尿素氮素的溶出过程,其溶出速率常数分别为0.0132和0.0067。硫酸铵处理的油菜株高、株重及产量均随氮素用量的增加呈指数型增加趋势,而LP30日型和LP70日型包膜尿素处理的油菜株高、株重及产量则均随氮素用量的增加呈直线型增加趋势。与硫酸铵处理相比,LP30日型和LP70日型包膜尿素处理,在施氮量为N 0.1 g kg-1和N 0%The effect of nitrogen solubility of two kinds of coated ureas(LP30 and LP70) on the growth and yield of rapes was studied with the method of fertilizer burying and pot experiment.The results showed that the first-order kinetic model could preferably describe the nitrogen solubility process of LP30 and LP70 coated ureas,the dissolution rate constant was 0.0132 and 0.0067 respectively.The plant height,weight and yield of rape all increased exponentially with the increasing of nitrogen amount for the treatment of ammonia sulfate,and the plant height,weight and yield of rape all increased linearly with the increasing of nitrogen amount for the treatment of LP30 and LP70.When the nitrogen amount was 0.1 g kg^-1 and 0.2 g kg^-1,the plant height,weight and yield of rape decreased significantly(P〈0.01)for the treatment of LP30 and LP70 compared with the treatment of ammonia sulfate,and LP70 coated urea decreased most obviously.When the nitrogen amount was 0.4 g kg^-1,the plant height,weight and yield of rape increased significantly(P〈0.01) for the treatment of LP30 coated urea,and no obvious increasing for the treatment of LP70 coated urea.The utilization rate of nitrogen fertilizer dissolution all obviously increased for two kinds of coated ureas.

  1. Urea transformation of wetland microbial communities.

    Science.gov (United States)

    Thorén, Ann-Karin

    2007-02-01

    Transformation of urea to ammonium is an important link in the nitrogen cycle in soil and water. Although microbial nitrogen transformations, such as nitrification and denitrification, are well studied in freshwater sediment and epiphytic biofilm in shallow waters, information about urea transformation in these environments is scarce. In this study, urea transformation of sedimentary, planktonic, and epiphytic microbial communities was quantified and urea transformation of epiphytic biofilms associated with three different common wetland macrophyte species is compared. The microbial communities were collected from a constructed wetland in October 2002 and urea transformation was quantified in the laboratory at in situ temperature (12 degrees C) with the use of the 14C-urea tracer method, which measures the release of 14CO2 as a direct result of urease activity. It was found that the urea transformation was 100 times higher in sediment (12-22 mmol urea-N m(-2) day(-1)) compared with the epiphytic activity on the surfaces of the submerged plant Elodea canadensis (0.1-0.2 mmol urea-N m(-2) day(-1)). The epiphytic activity of leaves of Typha latifolia was lower (0.001-0.03 mmol urea-N m(-2) day(-1)), while urea transformation was negligible in the water column and on the submerged leaves of the emergent plant Phragmites australis. However, because this wetland was dominated by dense beds of the submerged macrophyte E. canadensis, this plant provided a large surface area for epiphytic microbial activity-in the range of 23-33 m2 of plant surfaces per square meter of wetland. Thus, in the wetland system scale at the existing plant distribution and density, the submerged plant community had the potential to transform 2-7 mmol urea-N m(-2) day(-1) and was in the same magnitude as the urea transformation in the sediment.

  2. the effect of percentage of nitrogen in plasma gas on nitrogen ...

    African Journals Online (AJOL)

    user

    1985-09-01

    Sep 1, 1985 ... an arc plasma into liquid iron has been investigated by melting iron in an ... refining operations has been recognized for a long time. The last two ... 22. Fig 1 melting apparatus with sectioned view of furnace ... The electrical.

  3. Effects of combined application of urea and controlled-release urea on yield, profits of rapeseed and soil inorganic nitrogen%控释尿素与尿素配施对油菜籽产量、经济效益和土壤无机氮含量的影响

    Institute of Scientific and Technical Information of China (English)

    王素萍; 李小坤; 鲁剑巍; 李慧; 刘波; 吴庆丰; 汪航; 肖国滨; 薛欣欣

    2013-01-01

    2009-2010年在我国油菜主产区采用多点田间试验研究了控释尿素(controlled-release urea,CRU)和普通尿素(Urea)配合施用对油菜籽产量、氮肥利用率、土壤无机氮含量及经济效益的影响,以期为两者在油菜上的配合施用提供理论依据.结果表明,在所有试验点两者配施(60% CRU+40% Urea)比一次性基施等氮量普通尿素(100% Urea)增产菜籽11.4% ~ 12.9%,与一次性基施等氮量控释尿素(100% CRU)的产量无显著差异.苗期的干物质量和氮积累量表现相同规律,配施处理与100% Urea处理无显著差异,与100% CRU处理相比,除浠水试验点分别增加10.59% ~ 50.58%和10.40% ~ 28.57%外,成熟期配施与100% CRU处理无显著差异,但分别比100% Urea处理增加5.4%~20.9%和8.7% ~18.8%.配施的氮肥利用率比100% Urea处理提高7.6个百分点,可以达到100% CRU的效果.油菜收获后,配施处理的耕层土壤无机氮含量高于100% Urea处理5.0%~44.2%,低于100% CRU处理19.6% ~ 38.8%.经济效益分析结果显示,配施处理比100% Urea增收488.9~1 040.2元/hm2,比100% CRU增收205.3 ~ 599.0元/hm2.%To provide evidence for application of combined chemicals of CRU (controlled released urea),three sites of field trials were conducted in the main rapeseed zone of China in 2009 to 2010.Four treatments were designed as no nitrogen,100% urea,100% CRU and combined application-treatment (60% CRU + 40% Urea) to study the effects on yield,profits,nitrogen recovery efficiency of rapeseed and soil inorganic nitrogen content.Results showed that the combined application increased the yield by 11.4% to 12.9% compared to 100%CRU-treatment as based fertilizer.No significant difference was found in yield and dry matter between the 100%CRU-treatment and combined application-treatment.In seedling stage,dry matter and nitrogen accumulation of the combined application increased

  4. Liquid chromatographic determination of urea in water-soluble urea-formaldehyde fertilizer products and in aqueous urea solutions: collaborative study.

    Science.gov (United States)

    Hojjatie, Michael M; Abrams, Dean E; Parham, Thomas M; Balthrop, J; Beine, R; Dickinson, V; Hartshorn, J; Herald, S; Latimer, G; Padmore, J; Pleasants, S; Riter, K; Roser, R; Schmunck, G; Sensmeier, R; Smith, V; Taylor, L; Volgas, G

    2004-01-01

    Water soluble urea-formaldehyde (UF) fertilizers, manufactured by complex reaction of urea and formaldehyde, typically contain varying amounts of unreacted urea. A liquid chromatography method for the analysis of urea in these products, and in aqueous urea solutions, was collaboratively studied. An amine chromatography column was used to separate the unreacted urea from numerous UF reaction products present in these liquid fertilizers. Unreacted urea was determined by using external urea standards with UV detection at 195 nm. The standards and test samples were prepared in the mobile phase of 85% (v/v) acetonitrile in water. Ten laboratories analyzed 5 different UF-based commercial products containing unreacted urea in the range of 6 to 17% by weight, and 5 different concentrations of urea in water equivalent to commercial products of that nature. The aqueous urea solutions contained 2-20% urea (w/w). The range of s(R) values for the 5 UF-based commercial fertilizers was 0.49-1.02 and the %RSD(R) was 1.94-6.14. The s(R) range for the 5 urea solutions was 0.10 to 0.79 and the %RSD(R) range was 2.54 to 4.88. The average recovery of urea from the aqueous urea solutions was 96-103%. Therefore, this method is capable of monitoring urea nitrogen manufacturers' label claims and total nitrogen claims in those cases where urea is the sole source of plant food nitrogen. Based on the collaborative study data, the authors recommend this method be approved for AOAC Official First Action status.

  5. Variation of milk urea in dairy cattle : a study on factors that affect the relationship between urea concentration in milk and urea excretion in urine

    NARCIS (Netherlands)

    Spek, J.W.

    2013-01-01

    The aim of this thesis was to increase the applicability of milk urea nitrogen concentration (MUN) as a predictor of urinary urea nitrogen excretion (UUN) by identifying and quantifying factors that can explain variation in MUN that is not related to UUN. A literature study was conducted in order to

  6. ANALISA SPEKTROSKOPI EMISI UNTUK PENENTUAN TEMPERATUR ELEKTRONIK PADA PLASMA NON-TERMIK NITROGEN

    Directory of Open Access Journals (Sweden)

    Muhammad Nur

    2012-02-01

    Full Text Available Suatu metoda baru telah dikembangkan untuk penentuan temperatur elektronik dari plasma non-termik nitrogen dengan menggunakan spektroskopi emisi. Metoda ini telah dipakai untuk plasma non-termik nitrogen yang diproduksi dalam lucutan pijar korona densitas tinggi. Dengan mengasumsikan bahwa fungsi distribusi energi dari elektron adalah distribusi  maxwellian dan penggunaan data tampang lintang efektif dari sistem positif kedua, 2s+, (C3Pu®B3Pg dari N2 dan sistem negatif pertama, 1s– (B2S+u®X2S+g  dari N2+, hubungan antara energi rerata elektron dengan perbandingan intensitas 1s–(0-0 dan intensitas 2s+(2-5 dapat diselesaikan ecara teoretik. Spektrum emisi dari molekul nitrogen tereksitasi, (C3Pu®B3Pg dari N2 dan molekul terionisasi, 1s– (B2S+u®X2S+g dari N2+, secara eksperimen diperoleh dari spektroskopi emisi. Melalui identifikasi dan analisa spektru-spektrum tersebut, perbandingan intensitas 1s–(0-0 dan intensitas 2s+(2-5 diperoleh secara eksperimen. Metoda ini telah diterapkan untuk menentukan energi rerata elektron atau temperatur elektronik dari plasma non termik nitrogen dalam lucutan pijar korona dengan densitas dari 2,4 x 1020 cm-3 sampai 9,2 x 1020 cm-3

  7. Substituição total do farelo de soja por uréia ou amiréia, em dietas com alto teor de concentrado, sobre a amônia ruminal, os parâmetros sangüíneos e o metabolismo do nitrogênio em bovinos de corte Total replacement of soybean meal by urea or starea in high grain diets on nitrogen metabolism, ruminal ammonia-N concentration and blood parameters in beef cattle

    Directory of Open Access Journals (Sweden)

    Reinaldo Cunha de Oliveira Junior

    2004-06-01

    Full Text Available Seis novilhos da raça Nelore, não castrados, com peso médio inicial de 420 kg, distribuídos em delineamento em quadrado latino 3x3 duplicado, foram utilizados para avaliar a substituição total de uma fonte de proteína verdadeira (farelo de soja, em uma dieta deficiente em proteína degradável no rúmen (PDR, por uréia ou amiréia (fontes de nitrogênio não protéico, ambas em uma dieta adequada em PDR. As dietas foram isoprotéicas (13,0% utilizando-se o bagaço de cana-de-açúcar in natura (BIN como única fonte de volumoso (20% da MS. Foram avaliados: a concentração de amônia ruminal, nitrogênio uréico plasmático, glicose plasmática e o metabolismo do nitrogênio. Os tratamentos foram: 1 farelo de soja (FS; 2 uréia e 3 amiréia (A-150S. A concentração de nitrogênio amoniacal no fluido ruminal foi superior no tratamento com uréia, comparado ao tratamento com farelo de soja, sendo que o tratamento com amiréia não diferiu dos demais. O tratamento com amiréia apresentou maior perda de N urinário. A retenção de N (g/d e % do consumido e o valor biológico da proteína (N retido, % do N digerido foram superiores para o tratamento com uréia, comparado aos demais. A concentração de nitrogênio uréico no plasma e a concentração de glicose plasmática foram similares entre os tratamentos. A substituição total do farelo de soja por uréia, ajustando a PDR na dieta de bovinos de corte, demonstrou ser viável. A uréia na forma convencional apresentou vantagens em relação à amiréia.Six Nellore bulls, with initial body weight of 420 kg, were assigned to a duplicated 3x3 Latin square design to evaluate the effects of replacing a true protein source (soybean meal, of high biological value, in a rumen degradable protein (RDP deficient diet, by urea or starea (a supposedly slow release nonprotein nitrogen source, both in a RDP adjusted diet. In natura sugarcane bagasse as the only source of forage (20% of DM. Evaluated

  8. Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling.

    Science.gov (United States)

    Wang, Weizong; Patil, Bhaskar; Heijkers, Stjin; Hessel, Volker; Bogaerts, Annemie

    2017-05-22

    The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO2 yields and the corresponding energy efficiency for NOx formation for different N2 /O2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NOx . The results indicate that vibrational excitation of N2 in the gliding arc contributes significantly to activating the N2 molecules, and leads to an energy efficient way of NOx production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NOx formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale Haber-Bosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which low-temperature plasma technology might play an important role. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Modeling nitrogen plasmas produced by intense electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Angus, J. R.; Swanekamp, S. B.; Schumer, J. W.; Hinshelwood, D. D. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Mosher, D.; Ottinger, P. F. [Independent contractors for NRL through Engility, Inc., Alexandria, Virginia 22314 (United States)

    2016-05-15

    A new gas–chemistry model is presented to treat the breakdown of a nitrogen gas with pressures on the order of 1 Torr from intense electron beams with current densities on the order of 10 kA/cm{sup 2} and pulse durations on the order of 100 ns. For these parameter regimes, the gas transitions from a weakly ionized molecular state to a strongly ionized atomic state on the time scale of the beam pulse. The model is coupled to a 0D–circuit model using the rigid–beam approximation that can be driven by specifying the time and spatial profiles of the beam pulse. Simulation results are in good agreement with experimental measurements of the line–integrated electron density from experiments done using the Gamble II generator at the Naval Research Laboratory. It is found that the species are mostly in the ground and metastable states during the atomic phase, but that ionization proceeds predominantly through thermal ionization of optically allowed states with excitation energies close to the ionization limit.

  10. CEMS-investigations of AISI M2 steel after nitrogen plasma immersion ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Uglov, V.V. E-mail: info@research.bsu.unibel.by; Kholmetskii, A.L.; Kuleshov, A.K.; Fedotova, J.A.; Rusalsky, D.P.; Khodasevich, V.V.; Ruebenbauer, K.; Richter, E.; Guenzel, R.; Parascandola, S

    1999-01-02

    Plasma-immersion ion implantation (PIII) and high-current ion implantation (HCII) of nitrogen into M2 steel were carried out. The formation of a multilayer system consisting of a surface layer of austenite on top of {epsilon}-Fe{sub 3}N nitride precipitates was manifested in M2 steel after PIII. HCII forms a thick (more than 14 {mu}m) layer with {epsilon}-Fe{sub 3}N precipitates. Apparently, the formation of the austenite layer after PIII is connected with a local tempering of the steel surface by the pulsed nitrogen ion beam.

  11. Surface modification of polyacrylonitrile co-polymer membranes using pulsed direct current nitrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Dipankar; Neogi, Sudarsan; De, Sirshendu, E-mail: sde@che.iitkgp.ernet.in

    2015-12-31

    Low temperature plasma treatment using pulsed direct current discharge of nitrogen gas was employed to enhance hydrophilicity of the polyacrylonitrile co-polymer membranes. The membranes were characterized in terms of morphology, structure, hydrophilicity, and membrane performance. Properties and functional groups on the surface of polyacrylonitrile co-polymer membranes were investigated by contact angle, scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. Effects of plasma conditions, namely, pulsed voltage, duty cycle and treatment time on increase in membrane hydrophilicity were studied. Permeability of treated membrane was increased by 47% and it was retained up to 70 days. Surface etching due to plasma treatment was confirmed by weight loss of the treated membranes. Due to surface etching, average pore size increased and rejection of 200 kDa polyethylene glycol decreased to about 70% for the treated membrane. Oxygen and nitrogen functional groups were responsible for surface hydrophilicity. - Highlights: • Surface modification of polyacrylonitrile co-polymer membranes by pulsed direct current nitrogen plasma • Hydrophilic functional groups incorporated on the membrane surface • Significant enhancement of the permeability and wettability of the membranes • Water contact angle increased with storage time and finally stabilized.

  12. NITROGEN POTENTIAL DURING ION NITRIDING PROCESS IN GLOW-DISCHARGE PLASMA

    Directory of Open Access Journals (Sweden)

    A. A. Kozlov

    2015-01-01

    Full Text Available The paper considers problems on regulation of phase composition of a nitrided layer during gas and ion nitriding process in a glow-discharge. It has been established that  available models for control of nitrided layer structure with the help of nitriding index (nitrogen potential can not be applied for nitriding process in the glow-discharge. Principal difference of the ion nitriding from the gas one is in the fact that chemically active nitrogen is formed in the discharge zone (cathode layer and its mass-transfer is carried out in the form of an active particle flow (ions, atoms, molecules which directed to the metal surface.Interrelation of chemical discharge activity with such characteristics of nitriding steel as nitrogen solubility in  α-solid solution and  coefficient diffusion during ion nitriding in low-discharge plasma. It has been shown that regulation of the nitride layer structure during ion nitriding is reached due to changes in nitrogen flow density in plasma. While supporting the flow at the level of nitrogen solubility in  one phase or another (α, γ′  it is possible to obtain the nitrided layer consisting only of α-solid solution or γ′-nitride layer and diffusion sub-layer. Moreover a specific range of nitrogen flow density values exists for every steel grade where it is possible to ensure a limiting nitrogen concentration in α-solid solution and the γ′-layer characterized by low diffusion  mobility is not formed on the surface.

  13. A comparison of the effects of controlled release urea, stable urea and microorganisms increasing double rice yield and nitrogen use efficiency%控释尿素、稳定性尿素和配施菌剂尿素提高双季稻产量和氮素利用率的效应比较

    Institute of Scientific and Technical Information of China (English)

    王斌; 万运帆; 郭晨; 李玉娥; 秦晓波; 任涛; 赵婧

    2015-01-01

    剂均能促进植株生长、提高氮素利用率,其效果以包膜控释尿素最好也最稳定,添加硝化抑制剂的稳定肥料次之,与菌剂配施作用需进一步验证。%[Objectives] China is the largest producer and consumer of rice( Oryza sative L) in the world. Nitrogen is the most essential element for rice production, however, low nitrogen use efficiency(NUE)has been existed. New nitrogen fertilizers( controlled release urea, nitrification inhibitor and microbial inoculant) were developed to solve this problem. Their effects were compared in this paper to provide reliable basis for the fertilizer promotion in rice cultivation. [Methods] Five different fertilizer treatments, CK: conventional urea, CRU: polymer-coated controlled release urea, NU: urea containing nitrapyrin, DMPP: urea containing nitrification inhibitor 3, 4-dimethylpyrazole phosphate, and EM:microbial inoculant combined application with urea were set for conducting a two year field experiment ( 2012-2013 ) in Jingzhou city , Jianghan Plain, Central China. Effects of different fertilizers on growth( plant height, chlorophyll, tiller and spike numbers) , yield( grain numbers, setting rate, 1000-grain weight, straw and grain yield) and NUE( nitrogen recovery efficiency, nitrogen agronomic efficiency, nitrogen physiological efficiency) were explored. Increases in yield and NUE caused by different fertilizers were synthetically analyzed, and their seasonal fluctuations were also discussed. [Results]The new fertilizers contribute to the increases of rice plant height, chlorophyll concentration, tiller numbers, spike numbers, grain numbers, setting rate and 1000-grain weight, and ultimately improve the straw and grain yields effectively. Compared with CK, CRU achieves the highest and most stable yield increase by 18%(P<0. 05)in both early and late rice, and DMPP, NU and EM achieve a yield increase by 14%(P<0. 05)in late rice, no significant increases in early rice. Better growth and

  14. Molecular dynamics simulations of aqueous urea solutions: Study of dimer stability and solution structure, and calculation of the total nitrogen radial distribution function GN(r

    NARCIS (Netherlands)

    Boek, E.S.; Briels, W.J.

    1993-01-01

    Molecular dynamics simulations have been performed in order to study the structure of two molal urea solutions in D2O. Several initial dimer configurations were considered for an adequate sampling of phase space. Eventually all of them appeared to be unstable, when system size and periodic boundary

  15. Targeting cancer cells with reactive oxygen and nitrogen species generated by atmospheric-pressure air plasma.

    Directory of Open Access Journals (Sweden)

    Hak Jun Ahn

    Full Text Available The plasma jet has been proposed as a novel therapeutic method for cancer. Anticancer activity of plasma has been reported to involve mitochondrial dysfunction. However, what constituents generated by plasma is linked to this anticancer process and its mechanism of action remain unclear. Here, we report that the therapeutic effects of air plasma result from generation of reactive oxygen/nitrogen species (ROS/RNS including H2O2, Ox, OH-, •O2, NOx, leading to depolarization of mitochondrial membrane potential and mitochondrial ROS accumulation. Simultaneously, ROS/RNS activate c-Jun NH2-terminal kinase (JNK and p38 kinase. As a consequence, treatment with air plasma jets induces apoptotic death in human cervical cancer HeLa cells. Pretreatment of the cells with antioxidants, JNK and p38 inhibitors, or JNK and p38 siRNA abrogates the depolarization of mitochondrial membrane potential and impairs the air plasma-induced apoptotic cell death, suggesting that the ROS/RNS generated by plasma trigger signaling pathways involving JNK and p38 and promote mitochondrial perturbation, leading to apoptosis. Therefore, administration of air plasma may be a feasible strategy to eliminate cancer cells.

  16. 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.

  17. Volt-ampere characteristics of a nitrogen DC plasma arc with anode melting

    Institute of Scientific and Technical Information of China (English)

    Zhao Peng; Ni Guo-Hua; Meng Yue-Dong; Nagatsu Masaaki

    2013-01-01

    The characteristics of a nitrogen arc using a graphite cathode and a melting anode in a pilot-scale plasma furnace are investigated.The voltage is examined as a function of current and apparent plasma length.The voltage increases non-linearly with the increase of apparent plasma length,with the current fixed.The experimental data so obtained are compared with the predictions of the Bowman model for the electric arc,and with numerical simulations as well.The level of agreement between the experimental data at the melting anode and the numerical predictions confirms the suitability of the proposed the Bowman model.These characteristics are relevant to the engineering design and evaluation of a DC plasma furnace and reactor for the treatment of hazardous fly ash waste.

  18. Tuning the Electrical Properties of Graphene via Nitrogen Plasma-Assisted Chemical Modification.

    Science.gov (United States)

    Jung, Min Wook; Song, Wooseok; Jung, Dae Sung; Lee, Sun Sook; Park, Chong-Yun; An, Ki-Seok

    2016-03-01

    The control in electrical properties of graphene is essentially required in order to realize graphenebased nanoelectronics. In this study, N-doped graphene was successfully obtained via nitrogen plasma treatment. Graphene was synthesized on copper foil using thermal chemical vapor deposition. After N2 plasma treatment, the G-band of the graphene was blueshifted and the intensity ratio of 2D- to G-bands decreased with increasing the plasma power. Pyrrolic-N bonding configuration induced by N2 plasma treatment was studied by X-ray photoelectron spectroscopy. Remarkably, electrical characterization including Hall measurement and I-V characteristics of the N-doped graphene exhibit semiconducting behavior as well as the n-type doping effect.

  19. Atomic force microscopy of surface topography of nitrogen plasma treated steel

    CERN Document Server

    Mahboubi, F

    2002-01-01

    Nitriding of steels, using plasma environments has been practiced for many years. A lot of efforts have been put on developing new methods, such as plasma immersion ion implantation (Pl sup 3) and radio frequency (RF) plasma nitriding, for mass transfer of nitrogen into the surface of the work piece. This article presents the results obtained from an in depth investigation of the surface morphology of the treated samples, carried out using an atomic force microscope. Samples from a microalloyed steel, were treated by both methods for 5 hours at different temperatures ranging from 350 to 550 sup d eg sup C in 75% N sub 2 -25% H sub 2 atmosphere. It has been found that the surface of the samples treated by PI sup 3 technique, although having more favorable properties, were rougher than the surfaces treated by RF plasma nitriding.

  20. Effect of Plant Essential Oil on the Distribution of Urea-Nitrogen in Rumen Contents%植物精油对尿素氮在瘤胃内容物中分布的影响

    Institute of Scientific and Technical Information of China (English)

    赵圣国; 王加启; 卜登攀; 周凌云; 孙鹏

    2012-01-01

    [目的]揭示尿素氮在奶牛瘤胃内容物中的分布特点,阐明精油对尿素氮分布和瘤胃发酵的影响.[方法]在含瘤胃液和15N尿素的发酵瓶中,加入终浓度为300mg·L-1大蒜精油、茶树精油和尤加利精油,发酵后检测微生物中15N的丰度和瘤胃发酵指标,并利用DGGE刻画细菌群落变化.[结果]随着发酵时间的增加,瘤胃液中的尿素氮逐渐降低,而瘤胃固相和液相微生物中的尿素氮逐渐升高,发酵24h三者中的尿素氮基本持平.发酵24h时,与空白对照组相比,大蒜精油处理组瘤胃固相和液相微生物尿素氮丰度分别降低了22.60%和18.75%,发酵液pH和氨氮浓度分别降低了3.02%和17.80%,异丁酸和乙酸/丙酸值有所升高.茶树精油和尤加利精油则显著降低了发酵液pH(P<0.05),提高了异丁酸和乙酸/丙酸值.DGGE图谱显示,发酵24h时,3种植物精油可改变瘤胃细菌的群落结构.[结论]瘤胃尿素氮逐渐由瘤胃液向微生物中富集,大蒜精油可减缓尿素氮富集速度,改变细菌群落的组成,抑制氨氮生成.%[Objective] The objective of the experiment is to reveal the distribution of urea-nitrogen in rumen contents and the effect of essential oil on the distribution. [Method] Garlic oil, tea tree oil and eucalyptus oils were added into serum bottles containing rumen fluid and 15N-urea. The abundance of 15N and rumen fermentation were detected after incubation. The bacterial population was studied by DGGE. [ Result] Urea nitrogen in rumen fluid decreased and that in the microbes associated with rumen solid and liquid phases increased following the incubation time, and then had the similar level at 24 h. Compared to the control, urea nitrogen abundance in the microbes associated with rumen solid and liquid phases treated with garlic oil increased by 22.60% and 18.75%, pH and ammonia nitrogen decreased by 3.02% and 17.80%, respectively. The proportion of isobutyric acid and acetic acid

  1. DNA damage in oral cancer and normal cells induced by nitrogen atmospheric pressure plasma jets

    Science.gov (United States)

    Han, Xu; Kapaldo, James; Liu, Yueying; Stack, M. Sharon; Ptasinska, Sylwia

    2015-09-01

    Nitrogen atmospheric pressure plasma jets (APPJs) have been shown to effectively induce DNA double strand breaks in SCC25 oral cancer cells. The APPJ source constructed in our laboratory operates based on dielectric barrier discharge. It consists of two copper electrodes alternatively wrapping around a fused silica tube with nitrogen as a feed gas. It is generally more challenging to ignite plasma in N2 atmosphere than in noble gases. However, N2 provides additional advantages such as lower costs compared to noble gases, thus this design can be beneficial for the future long-term clinical use. To compare the effects of plasma on cancer cells (SCC25) and normal cells (OKF), the cells from both types were treated at the same experimental condition for various treatment times. The effective area with different damage levels after the treatment was visualized as 3D maps. The delayed damage effects were also explored by varying the incubation times after the treatment. All of these studies are critical for a better understanding of the damage responses of cellular systems exposed to the plasma radiation, thus are useful for the development of the advanced plasma cancer therapy. The research described herein was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Basic Energy Sciences, Office of Science, United States Department of Energy through Grant No. DE-FC02-04ER15533.

  2. Plasma Wind Tunnel Investigation of European Ablators in Nitrogen/Methane Using Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ricarda Wernitz

    2013-01-01

    Full Text Available For atmospheric reentries at high enthalpies ablative heat shield materials are used, such as those for probes entering the atmosphere of Saturn’s moon Titan, such as Cassini-Huygens in December, 2004. The characterization of such materials in a nitrogen/methane atmosphere is of interest. A European ablative material, AQ60, has been investigated in plasma wind tunnel tests at the IRS plasma wind tunnel PWK1 using the magnetoplasma dynamic generator RD5 as plasma source in a nitrogen/methane atmosphere. The dimensions of the samples are 45 mm in length with a diameter of 39 mm. The actual ablator has a thickness of 40 mm. The ablator is mounted on an aluminium substructure. The experiments were conducted at two different heat flux regimes, 1.4 MW/m2 and 0.3 MW/m2. In this paper, results of emission spectroscopy at these plasma conditions in terms of plasma species’ temperatures will be presented, including the investigation of the free-stream species, N2 and N2+, and the major erosion product C2, at a wavelength range around 500 nm–600 nm.

  3. Direct analysis of fluoxetine and norfluoxetine in plasma by gas chromatography with nitrogen-phosphorus detection.

    Science.gov (United States)

    Fontanille, P; Jourdil, N; Villier, C; Bessard, G

    1997-05-09

    A quantitative method for the simultaneous GC resolution and detection of fluoxetine and his metabolite norfluoxetine in human plasma was developed. The procedure required 1.0 ml of plasma, extraction with a mixed organic solvent and injection into a capillary gas chromatograph with an OV-1 fused-silica column coupled to a nitrogen-phosphorus detector. The calibration curves were linear over the range 5-3000 ng/ml. The detection limits were 0.3 and 2 ng/ml for fluoxetine and norfluoxetine, respectively. The assay is suitable for routine analysis.

  4. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor

    OpenAIRE

    2015-01-01

    Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine\\ud exhaust emissions treatment. In this paper, different electrode shapes are analysed and the ...

  5. Plasma Surface Modification of Polyhedral Oligomeric Silsequioxane-Poly(carbonate-urea) Urethane with Allylamine Enhances the Response and Osteogenic Differentiation of Adipose-Derived Stem Cells.

    Science.gov (United States)

    Chaves, Camilo; Alshomer, Feras; Palgrave, Robert G; Kalaskar, Deepak M

    2016-07-27

    This study present amino functionalization of biocompatible polymer polyhedral oligomeric silsequioxane-poly(carbonate-urea) urethane (POSS-PCU) using plasma polymerization process to induce osteogenic differentiation of adipose derived stem cells (ADSCs). Optimization of plasma polymerization process was carried out keeping cell culture application in mind. Thus, samples were rigorously tested for retention of amino groups under both dry and wet conditions. Physio-chemical characterization was carried out using ninhydrin test, X-ray photon spectroscopy, scanning electron microscopy, and static water contact analysis. Results from physio chemical characterization shows that functionalization of the amino group is not stable under wet conditions and optimization of plasma process is required for stable bonding of amino groups to the POSS-PCU polymer. Optimized samples were later tested in vitro in short and long-term culture to study differentiation of ADSCs on amino modified samples. Short-term cell culture shows that initial cell attachment was significantly (p < 0.001) improved on amine modified samples (NH2-POSS-PCU) compared to unmodified POSS-PCU. NH2-POSS-PCU samples also facilitates osteogenic differentiation of ADSCs as confirmed by immunological staining of cells for extracellular markers such as collagen Type I and osteopontin. Quantification of total collagen and ALP activity also shows significant (p < 0.001) increase on NH2-POSS-PCU samples compared to unmodified POSS-PCU. A pilot study also confirms that these optimized amino modified POSS-PCU samples can further be functionalized using bone inducing peptide such as KRSR using conventional wet chemistry. This further provides an opportunity for biofunctionalization of the polymer for various tissue specific applications.

  6. Short communication: urea transporter protein UT-B in the bovine parotid gland.

    Science.gov (United States)

    Dix, L; Ward, D T; Stewart, G S

    2013-03-01

    Ruminant nutrition relies upon the symbiotic relationship that exists with microbial populations in the rumen. Urea transported across the ruminal epithelia and secreted by the salivary glands is a key source of nitrogen for microbial growth in the rumen. As ruminal urea transport can be mediated by specific UT-B urea transporters, this study investigated whether UT-B urea transporters were also present in the bovine salivary gland. Western blotting experiments detected only small amounts of UT-B protein in whole-cell lysate from the bovine parotid gland. In contrast, strong 32 to 34 and 40 kDa UT-B proteins were detected in parotid plasma membrane-enriched protein, showing the importance of using enriched samples. These signals were also detected in rumen and correspond to bovine UT-B1 and UT-B2 urea transporters, respectively. Further immunolocalization studies identified that these proteins were located in the ductal system of the parotid gland. This study, therefore, confirmed the presence of UT-B urea transporter protein in the bovine parotid salivary gland.

  7. Modeling of the Flow, Temperature and Concentration Fields in an Arc Plasma Reactor with Argon-Nitrogen Atmosphere

    National Research Council Canada - National Science Library

    Fudolig, Agustin M; Nogami, Hiroshi; Yagi, Jun-ichiro

    1996-01-01

    A mathematical formulation was developed for describing the flow behavior, temperature profile and concentration fields in pure or mixed argon and nitrogen arc plasmas impinging on a metal target inside a reactor...

  8. 控释尿素与常规尿素不同配施对根际土壤微生物数目、土壤氮素及玉米产量的影响%Effects of Controlled-release Urea Combined with Conventional Urea on Rhizosphere Soil Microorganisms , Soil Nitrogen and Yield of Maize

    Institute of Scientific and Technical Information of China (English)

    孟庆英; 朱宝国; 王囡囡; 贾会彬; 于忠和; 张春峰

    2012-01-01

    为研究控释尿素与常规尿素配施条件下对玉米根际土壤微生物的影响,采用不同肥料配比处理,对玉米根际土壤细菌、真菌、放线菌采用平板计数法进行数量测定;对玉米成熟期根际土壤微生物数量变化、土壤氮素含量变化及玉米产量相关因素进行研究,结果表明控释尿素与常规尿素不同配施条件下,与CK相比施用肥料的各个处理,土壤微生物数量均增加,CRU100%处理有利于增加土壤细菌、土壤氮素含量及玉米产量,CRU40%+PU60%处理在增加土壤真菌及放线菌数量上优于其他配比。针对实际生产应用及对土壤微生物整体影响,综合比较本研究表明CRU40%+PU60%处理为最佳配比并为控释尿素与常规尿素配施条件下土壤微生物生态环境的深入研究提供依据。%Abstract: The objective of current study was to investigate the effects of controlled-release urea combined with conventional urea on rhizosphere soil microorganisms of maize. The numbers of bacteria, fungi, actinomycetes of rtizosphere soil were determined through colony counting method. The research included the effects of different fertilizers treatments on the changes of rhizosphere soil microorganisms of maize, nitrogen content of soil, yield and yieht components of maize at maturity. The results showed that effects of controlled-release urea combined with conventional urea on the number of microorganisms of soil were different. Compared with CK treatment, the amounts of miroorganisms in fertilizer treatments were higher. The CRU100% treatment improved of nitrogen content of soil and yield of maize. CRU40%+PU60% had higher value on the number of fungi and actinomycetes. According to the praetical production and application and the overall effects on the soil microorganisms, the research of comprehensive comparison showed that CRU40%+PU60% was the optimum proportion, and the study provided evidence

  9. Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides

    Science.gov (United States)

    Ravi, V.; Young, Sun Mok; Rajanikanth, B. S.; Kang, Ho-Chul

    2003-02-01

    A single-stage plasma-catalytic reactor in which catalytic materials were packed was used to remove nitrogen oxides. The packing material was scoria being made of various metal oxides including Al2O3, MgO, TiO2, etc. Scoria was able to act not only as dielectric pellets but also as a catalyst in the presence of reducing agent such as ethylene and ammonia. Without plasma discharge, scoria did not work well as a catalyst in the temperature range of 100 °C to 200 °C, showing less than 10% of NOx removal efficiency. When plasma is produced inside the reactor, the NOx removal efficiency could be increased to 60% in this temperature range.

  10. Preparation of nitrogen doped silicon oxides thin films by plasma polymerization of 3-aminopropyltriethoxylsilane using atmospheric pressure plasma jet

    Science.gov (United States)

    Lin, Yu-Chun; Wang, Meng-Jiy

    2016-01-01

    Surface modification techniques have been applied in various applications including self-cleaning surface, antibacterial filter, and biomaterials. In this study we employed the atmospheric pressure plasma jet (APPJ) deposition, a dry process for surface modification, to deposit 3-aminopropyltriethoxylsilane (APTES) on stainless steel (SS) on the purposes of simultaneously incorporating SiOx and nitrogen containing functionalities for the modulation of biofunctionality. The APPJ deposition allowed to form a thin layer of APTES with linear growth rate by controlling the deposition time. In addition, the surface chemical and physical properties, such as surface chemical composition, wettability, film thickness, and interactions with mammalian cells were evaluated by using different analytical methods. The results showed that the surface wettability was improved significantly due to the APTES deposition along with the increase of the incorporated nitrogen content. Moreover, the viability of L-929 fibroblasts was clearly promoted on the APTES deposited SS, which is most probably due to the thicker deposited films and higher density of nitrogen-containing functional groups. The outcomes of this research showed great potential to apply on metallic substrates in real time for biomedical related applications.

  11. Uréia como fonte alternativa de nitrogênio na micropropagação de abacaxizeiro cv. Pérola = Micropropagation of pineapple cv. Pérola with urea as nitrogen source

    Directory of Open Access Journals (Sweden)

    Maria Aparecida Moreira

    2007-12-01

    Full Text Available Objetivou-se estudar a viabilidade da substituição parcial ou total do nitrato de amônio por uréia como fonte de nitrogênio no meio de cultura para o cultivo in vitro do abacaxizeiro cv. Pérola. Plantas oriundas das gemas da coroa do fruto com massa fresca em torno de 80 mg foram inoculadas em meio MS (líquido e sólido substituindo-se 100, 80, 60, 40, 20 e 0% do nitrato de amônio por uréia. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições e três plantas/repetição. Após 60 dias,observou-se a possibilidade da substituição parcial de 40% de nitrato de amônio por uréia para as variáveis analisadas e melhor desenvolvimento das plantas em meio de cultura sólido.The partial or total substitution viability of the ammonium nitrate for urea, as source of nitrogen in the culture medium for the in vitro culture of pineapple cv. Pérola was studied. Plants originating from fruit crown buds with fresh weight matter around 80 mg was inoculated on MS medium (liquid and solid with substitution of 100, 80, 60, 40, 20 and 0% of the ammonium nitrate for urea. These treatments were arranged in a completely randomized design, with four replications and three plants/replications. After 60 days, thepossibility of 40% ammonium nitrate for urea partial substitution was observed for the analyzed variables. In addition, better plant development in solid culture medium was observed as well.

  12. Treatment of methyl orange by nitrogen non-thermal plasma in a corona reactor: The role of reactive nitrogen species

    Energy Technology Data Exchange (ETDEWEB)

    Cadorin, Bruno Mena, E-mail: brunomenacadorin@gmail.com [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Tralli, Vitor Douglas [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Ceriani, Elisa [Department of Chemical Sciences, Università di Padova (Italy); Benetoli, Luís Otávio de Brito [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Marotta, Ester, E-mail: ester.marotta@unipd.it [Department of Chemical Sciences, Università di Padova (Italy); Ceretta, Claudio [Department of Industrial Engineering, Università di Padova (Italy); Debacher, Nito Angelo [Department of Chemistry, Universidade Federal de Santa Catarina (Brazil); Paradisi, Cristina [Department of Chemical Sciences, Università di Padova (Italy)

    2015-12-30

    Highlights: • Nitration of methyl orange is one of the main processes in treatment with N{sub 2}-plasma. • MS/MS analysis shows preferred nitration of methyl orange in ortho position. • N{sub 2} plasma, N{sub 2}-PAW, reaction with NO{sub 2}{sup −} or NO{sub 2}{sup −}/H{sub 2}O{sub 2} at pH 2 give the same products. - Abstract: Methyl orange (MO) azo dye served as model organic pollutant to investigate the role of reactive nitrogen species (RNS) in non-thermal plasma (NTP) induced water treatments. The results of experiments in which MO aqueous solutions were directly exposed to N{sub 2}-NTP are compared with those of control experiments in which MO was allowed to react with nitrite, nitrate and hydrogen peroxide, which are species formed in water exposed to N{sub 2}-NTP. Treatment of MO was also performed in PAW, Plasma Activated Water, that is water previously exposed to N{sub 2}-NTP. Both direct N{sub 2}-NTP and N{sub 2}-PAW treatments induced the rapid decay of MO. No appreciable reaction was instead observed when MO was treated with NO{sub 3}{sup −} and H{sub 2}O{sub 2} either under acidic or neutral pH. In contrast, in acidic solutions MO decayed rapidly when treated with NO{sub 2}{sup −} and with a combination of NO{sub 2}{sup −} and H{sub 2}O{sub 2}. Thorough product analysis was carried out by HPLC coupled with UV–vis and ESI–MS/MS detectors. In all experiments in which MO reaction was observed, the major primary product was a derivative nitro-substituted at the ortho position with respect to the N,N-dimethylamino group of MO. The reactions of RNS are discussed and a mechanism for the observed nitration products is proposed.

  13. Fontes alternativas à ureia no fornecimento de nitrogênio para o arroz irrigado Alternative sources of supply in the urea nitrogen for rice production

    Directory of Open Access Journals (Sweden)

    Enio Marchesan

    2011-12-01

    Full Text Available A ureia é a principal fonte de N usada na agricultura, mas apresenta grandes perdas em arroz irrigado por alagamento. O objetivo deste trabalho foi avaliar a eficiência de fontes de N alternativas à ureia para utilização pelo arroz irrigado aplicadas em diferentes estádios de desenvolvimento da planta através da quantificação da volatilização de N-NH3 e de parâmetros agronômicos. O experimento foi realizado em campo nos anos agrícolas 2007/08 e 2008/09. O delineamento experimental foi de blocos ao acaso com quatro repetições. Os tratamentos foram compostos de diferentes fontes de N aplicados na semeadura, no perfilhamento e no estádio de diferenciação floral: testemunha sem aplicação de N, ureia, ureia+inibidor de urease, duas fontes de N líquido (N-28 e N- 30, sulfato de amônio e ureia + enxofre. Nas duas safras, a volatilização de N-NH3 na semeadura foi praticamente insignificante, enquanto no estádio V4 a fonte que menos volatilizou foi o sulfato de amônio. A resposta em produtividade variou entre os anos, provavelmente em função da disponibilidade de N no solo e aspectos climáticos. Quando vantajoso economicamente, o uso do inibidor de urease e o sulfato de amônio proporcionam produtividades semelhantes à fonte ureia.Urea is the main source of N used in agriculture, but has large losses in irrigated rice. The objective of this study was to evaluate the efficiency of N sources alternative to urea for use by rice applied at different stages of plant development through the quantification of N-NH3 and agronomic parameters. The experiment was conducted in the field in the agricultural years 2007/08 and 2008/09. The experimental design was randomized blocks with four replications. The treatments consisted of different N sources applied at seeding, tillering and at the stage of floral differentiation: control without N, urea, urea + urease inhibitor, two sources of liquid N (N-28 and N-30 ammonium sulfate and urea

  14. The effect of surface modification by nitrogen plasma on photocatalytic degradation of polyvinyl chloride films

    Science.gov (United States)

    Xiao-jing, L.; Guan-jun, Q.; Jie-rong, C.

    2008-08-01

    The solid-phase photocatalytic degradation of poly(vinyl chloride) (PVC) films was investigated under the ambient air in order to assess the feasibility of developing photodegradable polymers. Nitrogen plasma was used to modify PVC films to enhance the photocatalytic degradation of PVC with nano-sized anatase TiO 2. The plasma parameter varied in this study is discharge power from 30 to 120 W for a constant treatment time of 60 s and a constant gas pressure of 10 Pa. The photodegradation of the plasma-treated PVC-TiO 2 films was compared with that of pure PVC films and PVC-TiO 2 films performing weight loss monitoring, scanning electron microscopy (SEM) analysis, contact angle measurements, electron spin resonance (ESR), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The wettability of the plasma-treated PVC is improved significantly. ESR revealed that the signal of radicals on the surface of the plasma-treated PVC film was enhanced after the treatment. Furthermore, the weight loss indicated that TiO 2 speeds up the photocatalytic degradation of PVC chains. The SEM image of the plasma-treated PVC-TiO 2 film showed a lot of crack on the film surface after irradiation. XPS indicated that the C and Cl atomic concentration reached minimum values on the surface of plasma-treated PVC-TiO 2 under identical photocatalytic condition. The experimental results reveal that plasma treatment can obviously enhance the photocatalytic degradation of PVC.

  15. The use of urea to combat nitrogen oxides; Selective catalytic denitrification of Diesel emissions. Mit Harnstoff gegen Stickoxide; Selektive katalytische Entstickung von Dieselabgasen

    Energy Technology Data Exchange (ETDEWEB)

    Koebel, M.; Elsener, M.; Eicher, H. (Paul Scherrer Inst. (PSI), Villigen (Switzerland))

    1990-01-01

    Reports available deal with efforts to denitrify Diesel emissions by the use of urea instead of ammonia and applying an SCT (selective catalytic reduction) process. These efforts are pursued in a common project carried out by the Paul Scherrer Institute and the Eicher + Pauli AG, and promoted by the Federal Office of Energy. The Paul Scherrer Institute is dedicated mainly to basic research, and technique of analyzing and laboratory work, while Eicher + Pauli AG are responsible for the construction and operation of the pilot plant.

  16. Signature of superradiance from a nitrogen gas plasma channel produced by strong field ionization

    CERN Document Server

    Li, Guihua; Zeng, Bin; Xie, Hongqiang; Yao, Jinping; Chu, Wei; Ni, Jielei; Zhang, Haisu; Xu, Huailiang; Cheng, Ya; Xu, Zhizhan

    2013-01-01

    Recently, Yao et al. demonstrated the creation of coherent emissions in nitrogen gas with two-color (800 nm + 400 nm) ultrafast laser pulses [New J. Phys. 15, 023046 (2013)]. Based on this two-color scheme, here we report on systematic investigation of temporal characteristics of the coherent emission at 391 nm by experimentally examining its evolution with the increase of the plasma channel induced by the intense 800 nm femtosecond laser pulses at a nitrogen gas pressure of ~25 mbar. We reveal unexpected temporal profiles of the coherent emissions, which show significant superradiance signatures owing to the quantum coherence via cooperation of an ensemble of excited N2+ molecules. Our findings shed more light on the mechanisms behind the laser-like emissions induced by strong-field ionization of molecules.

  17. Melting and spheroidization of hexagonal boron nitride in a microwave-powered, atmospheric pressure nitrogen plasma `

    Energy Technology Data Exchange (ETDEWEB)

    Gleiman, S. S. (Seth S.); Phillips, J. (Jonathan)

    2001-01-01

    We have developed a method for producing spherically-shaped, hexagonal phase boron nitride (hBN) particles of controlled diameter in the 10-100 micron size range. Specifically, platelet-shaped hBN particles are passed as an aerosol through a microwave-generated, atmospheric pressure, nitrogen plasma. In the plasma, agglomerates formed by collisions between input hBN particles, melt and forms spheres. We postulate that this unprecedented process takes place in the unique environment of a plasma containing a high N-atom concentration, because in such an environment the decomposition temperature can be raised above the melting temperature. Indeed, given the following relationship [1]: BN{sub (condensed)} {leftrightarrow} B{sub (gas)} + N{sub (gas)}. Standard equilibrium thermodynamics indicate that the decomposition temperature of hBN is increased in the presence of high concentrations of N atoms. We postulate that in our plasma system the N atom concentration is high enough to raise the decomposition temperature above the (undetermined) melting temperature. Keywords Microwave plasma, boron nitride, melting, spherical, thermodynamics, integrated circuit package.

  18. Effect of the nature of the nitrogen source on the urea content of milk from the Sicilo–Sarde dairy ewes

    Directory of Open Access Journals (Sweden)

    Houcine Selmi,

    2011-03-01

    Full Text Available Twenty (20 Sicilo-Sarde ewes were divided into two homogeneous batches according to age (5.3±1.25 years and 5.7±1.15 years, litter size (1.1±0.31, lactation number (4.3±1.25 and 4.6±0.96 and weight (33.83±5.63 and 33.95±5.58 kg. Ewes housed in two identical boxes with an area of 10.14 m2 each (1.01 m2/brebis received a ration of common base (oat hay at 1.5 kg DM/ewe/day supplemented per 500g/ewe/day of a standard concentrate diet composed of corn, barley, wheat bran, soybean and vitamins and minerals supplement sheep (control group: CC, and a concentrated feed composed of local white sorghum, horse beans and a sheep vitamin and mineral supplement (experimental group: CS. A weekly milk recording took place to determine the concentration of urea in milk during the ten (10 weeks of the first phase of trafficking. The average grade of urea was 53.5±8.76 for the lot and 35CC, 5±3.4 mg/dl for the outcome of the sheep milk fed the CS with significant difference (p <0.05.

  19. Effects of dietary nitrogen concentration on messenger RNA expression and protein abundance of urea transporter-B and aquaporins in ruminal papillae from lactating Holstein cows

    DEFF Research Database (Denmark)

    Røjen, Betina Amdisen; Poulsen, Søren Brandt; Theil, Peter Kappel

    2011-01-01

    To test the hypothesis that dietary N concentrations affect gut epithelial urea transport by modifying the expression of urea transporter B (UT-B) and aquaporins (AQP), the mRNA expression and protein abundance of UT-B and AQP3, AQP7, AQP8, and AQP10 were investigated in ruminal papillae from 9...... lactating dairy cows. Ruminal papillae were harvested from cows fed low N (12.9% crude protein) and high N (17.1% crude protein) diets in a crossover design with 21-d periods. The mRNA expression was determined by real-time reverse transcription-PCR and protein abundance by immunoblotting. The mRNA...... expression of UT-B was not affected by dietary treatment, whereas mRNA expression of AQP3, 7, and 10 were greater in the high N compared with the low N fed cows. Using peptide-derived rabbit antibodies to cow AQP3, 7, and 8, immunoblotting revealed bands of approximately 27, 27, and 24 kDa in ruminal...

  20. Effect of Control Release Urea on Spring Maize Yield, N Use Efficiency and Soil Nitrogen%控释尿素对玉米产量、氮肥利用率及土壤氮素的影响

    Institute of Scientific and Technical Information of China (English)

    曹宁; 陈志怡; 闫飞; 杨振明

    2012-01-01

    The experiments were conducted to investigate the effects of single basal application of control release urea with kieselguhr as the carrier on rate of yield of maize, shoot dry weight and N uptake of maize in different growth stages, NH4+ - N and NO3 - N of soil. The results show that control release urea application could increase shoot dry weight and N use efficiency of maize, inhibit urease activity of soil and maintain soil NH4+ - N and N03 - N during the late growth stage. The treatments of twice fertilization and control release urea could increase yield by 23.48% and 17.70% , improve N use efficiency by 17.33% and 17.58% , respectively. Therefore, the control release urea in this study can be used by single basal application to maize production system, and help to change twice fertilization (basal and dressing) to once fertilization (basal), and thus benefit to labor-saving and improve nitrogen utilization efficiency.%采用田间试验,研究了施用硅藻土为载体的控释尿素对玉米不同生育期地上部生物量、吸氮量以及土壤尿酶活性、硝态氮和铵态氮含量及产量和氮肥利用率的影响.结果表明:与普通尿素一次性施用相比,控释尿素能提高玉米生长后期地上部生物量和吸氟量,抑制脲酶活性,维持土壤氮素水平,提高玉米产量和氮肥利用率,其效果与普通尿素分次施用相当.尿素分次施用和控释尿素处理分别比尿素一次性施用处理产量增加23.48%和17.70%,氮肥利用效率提高17.33%和17.58%,这说明以硅藻土为载体的控释尿素替代普通尿素,一次性基施的施肥方式替代基肥加追肥是可行的,能达到省工、增效的目的.

  1. High active nitrogen flux growth of GaN by plasma assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    McSkimming, Brian M., E-mail: mcskimming@engineering.ucsb.edu; Speck, James S. [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States); Chaix, Catherine [RIBER S.A., 3a Rue Casimir Périer, BP 70083, 95873 Bezons Cedex (France)

    2015-09-15

    In the present study, the authors report on a modified Riber radio frequency (RF) nitrogen plasma source that provides active nitrogen fluxes more than 30 times higher than those commonly used for plasma assisted molecular beam epitaxy (PAMBE) growth of gallium nitride (GaN) and thus a significantly higher growth rate than has been previously reported. GaN films were grown using N{sub 2} gas flow rates between 5 and 25 sccm while varying the plasma source's RF forward power from 200 to 600 W. The highest growth rate, and therefore the highest active nitrogen flux, achieved was ∼7.6 μm/h. For optimized growth conditions, the surfaces displayed a clear step-terrace structure with an average RMS roughness (3 × 3 μm) on the order of 1 nm. Secondary ion mass spectroscopy impurity analysis demonstrates oxygen and hydrogen incorporation of 1 × 10{sup 16} and ∼5 × 10{sup 17}, respectively. In addition, the authors have achieved PAMBE growth of GaN at a substrate temperature more than 150 °C greater than our standard Ga rich GaN growth regime and ∼100 °C greater than any previously reported PAMBE growth of GaN. This growth temperature corresponds to GaN decomposition in vacuum of more than 20 nm/min; a regime previously unattainable with conventional nitrogen plasma sources. Arrhenius analysis of the decomposition rate shows that samples with a flux ratio below stoichiometry have an activation energy greater than decomposition of GaN in vacuum while samples grown at or above stoichiometry have decreased activation energy. The activation energy of decomposition for GaN in vacuum was previously determined to be ∼3.1 eV. For a Ga/N flux ratio of ∼1.5, this activation energy was found to be ∼2.8 eV, while for a Ga/N flux ratio of ∼0.5, it was found to be ∼7.9 eV.

  2. Distribution of urea in the waters of the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.

    at some levels and very low concentrations at others. Urea concentration increases towards the central west coast of India. Comparison with the other inorganic nutrients indicates that urea constitutes 10% of the available nitrogen in the euphotic zone (0...

  3. 新型包膜尿素抑制氮素挥发及其降解性研究%Study on nitrogen volatilization and degradation of organic-inorganic complex coated slow-release urea

    Institute of Scientific and Technical Information of China (English)

    邹洪涛; 韩艳玉; 虞娜; 张玉玲; 曹敏建; 黄毅; 汪景宽; 张玉龙

    2011-01-01

    In order to reveal the effect of new organic-inorganic complex coated slow-release urea on the environment, a laboratory culture experiment and a field plot were conducted respectively to study the nitrogen volatilization of new organic-inorganic complex coated slow-release urea and the degradation of membrane in soil. The result shows that the main volatilization of nitrogen is NH3. Volatilization peaks of NH3, Noxof BG and BF appear slow. The NH3 evaporation rate of BG and BF are 54.8% and 51.3% lower than that of CK while the NOX evaporation rate of BG and BF are 47.8% and 41.8% lower than that of CK. SEM image shows that some tiny holes presents on the surface of membrane material in the red pepper plant. After the red pepper harvest, the crack and holes presents after exposing for another 60 days in the natural environment. The results of this study provide a new way for developing coated slow-release urea with a low cost and environment friendly way.%为揭示新型包膜尿素对环境的影响,采用室内培养和室外田间小区相结合的研究方法,研究了有机无机复合物包膜尿素抑制氮素挥发及其在土壤中降解性.研究结果表明,氮素挥发主要以NH3为主,制备的两种新型包膜尿素BG、BF的NH3、NOx的挥发高峰期出现的时间延缓,NH3挥发率比未包膜尿素CK降低了54.8%、51.3%, NOx挥发率比CK降低了47.8%、41.8%;电镜图像分析表明,在辣椒整个生长期内,膜材料表面出现一些细微的孔隙;辣椒收获后在自然环境中继续暴露60d后膜材料表面产生裂缝和孔洞.研究结论为研发廉价、环境友好的包膜肥料提出新的思路.

  4. Effect of oxygen plasma and thermal oxidation on shallow nitrogen-vacancy centers in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M.; Rugar, D., E-mail: rugar@us.ibm.com [IBM Research Division, Almaden Research Center, San Jose, California 95120 (United States); Center for Probing the Nanoscale, Stanford University, Stanford, California 94305 (United States); Mamin, H. J.; Sherwood, M. H.; Rettner, C. T.; Frommer, J. [IBM Research Division, Almaden Research Center, San Jose, California 95120 (United States)

    2014-07-28

    We investigate the effect of two different surface treatments on shallow nitrogen-vacancy (NV) centers in diamond. Short duration oxygen plasma exposure is found to damage near-surface NV centers, resulting in their disappearance in fluorescence images. Subsequent annealing creates large numbers of new NV centers, attributed to plasma-induced vacancy creation. By tracking individual NV centers during thermal oxidation, we show that oxidation at 550 °C results in modest improvement of spin coherence. Higher temperature oxidations correlate with gradual decline in spin coherence and eventual instability of NV centers before ultimate disappearance. This is indicative of a reduction of the NV-to-surface distance due to oxidative etching. Thermal oxidation can offer controlled access to near-surface NV spins at the nanometer scale, an important requirement for many applications of NV-based nanomagnetometry.

  5. Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A single-stage plasma-catalytic reactor in which catalytic materials were packedwas used to remove nitrogen oxides. The packing material was scoria being made of various metaloxides including A12O3, MgO, TiO2, etc. Scoria was able to act not only as dielectric pelletsbut also as a catalyst in the presence of reducing agent such as ethylene and ammonia. Withoutplasma discharge, scoria did not work well as a catalyst in the temperature range of 100 °Cto 200 °C, showing less than 10% of NOx removal efficiency. When plasma is produced inside thereactor, the NOx removal efficiency could be increased to 60% in this temperature range.

  6. The role of electron scattering with vibrationally excited nitrogen molecules on non-equilibrium plasma kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Capitelli, Mario [Dipartimento di Chimica, Universitá di Bari, Via Orabona 4, 70125 Bari (Italy); CNR-IMIP, Via Amendola 122/D, 70126 Bari (Italy); Colonna, Gianpiero; D' Ammando, Giuliano; Laricchiuta, Annarita [CNR-IMIP, Via Amendola 122/D, 70126 Bari (Italy); Laporta, Vincenzo [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2013-10-15

    Electron energy distribution functions have been calculated by a self-consistent model which couples the electron Boltzmann equation with vibrationally and electronically excited state kinetics and plasma chemistry. Moderate pressure nitrogen gas discharges in the E/N range from 30 to 60 Townsend are investigated comparing an electron-impact cross section set considering transitions starting from all the vibrational states, with reduced models, taking into account only collisions involving the ground vibrational level. The results, while confirming the important role of second kind collisions in affecting the eedf, show a large dependence of the eedf on the set of inelastic processes involving vibrationally and electronically excited molecules, pointing out the need of using a cross section database including processes linking excited states in non-equilibrium plasma discharge models.

  7. Production and levels of foliar nitrogen in rocket salad fertilized with controlled-release nitrogen fertilizers and urea Produção e teor de nitrogênio foliar em rúcula adubada com fertilizantes nitrogenados de liberação lenta e uréia

    Directory of Open Access Journals (Sweden)

    Rafael Felippe Ratke

    2011-06-01

    Full Text Available Controlled-release nitrogen fertilizers enhance crop productivity and decrease nitrogen loss through volatilization and leaching. This study aimed at determining the effect of nitrogen treatments provided by controlled-release nitrogen fertilizers and urea. The following fertilizers were tested: 1 (agricultural urea, 2 (ammonium sulfonitrate + nitrification inhibitor, dimethylpyrazole phosphate (Entec 26®,3 (urea + Kimberlit polymer (Kimcoat N® and 4 (urea + NBPT (Super N - Agrotain®. Treatments corresponded to 0, 100, 200, 400 and 800 kg ha-1 of N with rocket salad grown inside a greenhouse, assessing the production of fresh and dry leaf mass as well as levels of foliar nitrogen. Doses of different controlled-release nitrogen fertilizers showed significant polynomial regressions for the production of rocket salad fresh leaf mass and levels of foliar nitrogen, whereby Entec 26® did not show significant polynomial regression, considering the last parameter evaluated. The production of rocket salad dry leaf mass did not display significant linear regressions. The maximal production of rocket salad fresh leaf mass was reached at doses of 600, 490, 765, and 462 kg ha-1 of N with the use of urea, Entec 26®, Kimcoat N® and Super N®, respectively.Os fertilizantes nitrogenados de liberação lenta aumentam a produtividade das culturas e diminuem as perdas de nitrogênio por volatilização e lixiviação. O objetivo deste trabalho foi determinar, no cultivo de rúcula, o efeito de doses de N fornecidas por fertilizantes nitrogenados de liberação lenta e pela uréia. Testaram-se os fertilizantes: 1 (uréia agrícola, 2 (sulfonitrato de amônio + inibidor de nitrificação Dimetil Pirazol Fosfato (Entec 26®,3 (uréia + polímero Kimberlit (kimcoat N® e 4 (uréia + NBPT (Super N - Agrotain®, e as doses de 0, 100, 200, 400 e 800 kg ha-1 de N em rúcula crescidas em casa de vegetação, avaliando-se a produtividade de matéria fresca de folhas

  8. Produção de proteína microbiana, concentração plasmática de uréia e excreções de uréia em novilhos alimentados com diferentes níveis de uréia ou casca de algodão Effects of feeding different levels of urea or cottonseed hulls on microbial protein synthesis, plasma urea concentration and urea excretion in steers

    Directory of Open Access Journals (Sweden)

    Karla Alves Magalhães

    2005-08-01

    Full Text Available Com o objetivo de avaliar os efeitos dos níveis de uréia ou casca de algodão sobre a produção de proteína microbiana, estimada por meio dos derivados de purinas na urina, a concentração de uréia plasmática (NUP e as excreções de uréia em novilhos, foram realizados dois experimentos. No primeiro, 24 novilhos mestiços castrados, com peso vivo médio inicial de 300 kg, foram alocados em delineamento inteiramente casualizado, nos quatro tratamentos: 0; 0,65; 1,30 e 1,95% de uréia na base da MS total, em substituição à proteína do farelo de soja. No segundo, 16 novilhos mestiços, com peso vivo médio inicial de 230 kg, foram distribuídos em delineamento inteiramente casualizado, nos quatro tratamentos: 0, 10, 20 e 30% de casca de algodão na base da MS total, em substituição à silagem de capim-elefante. As amostras de urina foram obtidas por meio da coleta de urina spot, na qual foram determinados os derivados de purinas (alantoína e ácido úrico. No soro sanguíneo e na urina, foram analisadas as concentrações de uréia e creatinina. Não houve efeito dos níveis de uréia, tampouco dos de casca de algodão, sobre os derivados de purinas e sobre a eficiência de síntese microbiana. A concentração de NUP e a excreção de uréia não foram influenciadas pelos níveis de uréia das rações. A concentração de NUP decresceu linearmente com a inclusão da casca de algodão na dieta. Tanto a uréia quanto a casca de algodão podem ser utilizadas, até os níveis de 1,95% e 30%, respectivamente, na MS total da dieta de novilhos de origem leiteira, sem afetar a eficiência de síntese microbiana.Two trials were conducted to study the effects of different levels of urea or cottonseed hulls on yield of microbial protein, estimated by the urinary excretion of purine derivatives, concentration of plasma urea, and excretion of urea in steers. In the first trial, 24 crossbred castrated steers averaging 300 kg of initial live

  9. Physiological and transcriptomic aspects of urea uptake and assimilation in Arabidopsis plants.

    Science.gov (United States)

    Mérigout, Patricia; Lelandais, Maud; Bitton, Frédérique; Renou, Jean-Pierre; Briand, Xavier; Meyer, Christian; Daniel-Vedele, Françoise

    2008-07-01

    Urea is the major nitrogen (N) form supplied as fertilizer in agriculture, but it is also an important N metabolite in plants. Urea transport and assimilation were investigated in Arabidopsis (Arabidopsis thaliana). Uptake studies using (15)N-labeled urea demonstrated the capacity of Arabidopsis to absorb urea and that the urea uptake was regulated by the initial N status of the plants. Urea uptake was stimulated by urea but was reduced by the presence of ammonium nitrate in the growth medium. N deficiency in plants did not affect urea uptake. Urea exerted a repressive effect on nitrate influx, whereas urea enhanced ammonium uptake. The use of [(15)N]urea and [(15)N]ammonium tracers allowed us to show that urea and ammonium assimilation pathways were similar. Finally, urea uptake was less efficient than nitrate uptake, and urea grown-plants presented signs of N starvation. We also report the first analysis, to our knowledge, of Arabidopsis gene expression profiling in response to urea. Our transcriptomic approach revealed that nitrate and ammonium transporters were transcriptionally regulated by urea as well as key enzymes of the glutamine synthetase-glutamate synthase pathway. AtDUR3, a high-affinity urea transporter in Arabidopsis, was strongly up-regulated by urea. Moreover, our transcriptomic data suggest that other genes are also involved in urea influx.

  10. Effect of abomasal infusion of oligofructose on portal-drained visceral ammonia and urea-nitrogen fluxes in lactating Holstein cows

    DEFF Research Database (Denmark)

    Røjen, Betina Amdisen; Larsen, Mogens; Kristensen, Niels Bastian

    2012-01-01

    The effects of abomasal infusion of oligofructose in lactating dairy cows on the relationship between hindgut fermentation and N metabolism, and its effects on NH3 absorption and transfer of blood urea-N across the portal-drained viscera versus ruminal epithelia were investigated. Nine lactating...... treatments. Eight sample sets of arterial, portal, hepatic, and ruminal vein blood, ruminal fluid, and urine were obtained at 0.5 h before the morning feeding and at 0.5, 1.5, 2.5, 3.5, 4.5, 5.5, and 6.5 h after feeding. It was hypothesized that an increased supply of fermentable substrate to the hindgut...

  11. Production characteristics of reactive oxygen/nitrogen species in water using atmospheric pressure discharge plasmas

    Science.gov (United States)

    Takahashi, Kazuhiro; Satoh, Kohki; Itoh, Hidenori; Kawaguchi, Hideki; Timoshkin, Igor; Given, Martin; MacGregor, Scott

    2016-07-01

    A pulsed discharge, a DC corona discharge, and a plasma jet are separately generated above a water surface, and reactive oxygen species and reactive nitrogen species (ROS/RNS) in the water are investigated. ROS/RNS in water after the sparging of the off-gas of a packed-bed dielectric barrier discharge (PB-DBD) are also investigated. H2O2, NO2 -, and NO3 - are detected after plasma exposure and only NO3 - after off-gas sparging. Short-lifetime species in plasma are found to play an important role in H2O2 and NO2 - production and long-lifetime species in NO3 - production. NO x may inhibit H2O2 production through OH consumption to produce HNO2 and HNO3. O3 does not contribute to ROS/RNS production. The pulsed plasma exposure is found to be effective for the production of H2O2 and NO2 -, and the off-gas sparging of the PB-DBD for the production of NO3 -.

  12. Improvement of Optical Reactivity for Nano-TiO2 Film by Nitrogen ECR Plasma

    Institute of Scientific and Technical Information of China (English)

    Yuying XIONG; Tao MA; Linghong KONG; Junfang CHEN; Xianqiu WU; Honghua YU; Zhenxi ZHANG

    2006-01-01

    Nitrogen ion was implanted into the nano-TiO2 film surfaces by electron cyclotron resonance (ECR) plasma modification to improve the optical reactivity in visible-light region for nano-TiO2. Diagnosing the N2 plasma by optical emission spectroscopy (OES) was applied to the process of plasma modification. X-ray photoelectron spectroscopy (XPS) was used for analysis of the binding of element after plasma modification. It is shown that the surface modification was caused by excitated N. The injecting of N2 and N2+ leads to the increase in the dissociative interstitial state N in the films. The doped N makes for TiO2-xNx appearing in the TiO2films. TiO2-xNx forms the impurity energy state in the TiO2 energy band gap and reduces the energy band gap. This is the main reason leading to the red shift of absorption edge.

  13. Urea retranslocation from senescing Arabidopsis leaves is promoted by DUR3-mediated urea retrieval from leaf apoplast.

    Science.gov (United States)

    Bohner, Anne; Kojima, Soichi; Hajirezaei, Mohammad; Melzer, Michael; von Wirén, Nicolaus

    2015-02-01

    In plants, urea derives either from root uptake or protein degradation. Although large quantities of urea are released during senescence, urea is mainly seen as a short-lived nitrogen (N) catabolite serving urease-mediated hydrolysis to ammonium. Here, we investigated the roles of DUR3 and of urea in N remobilization. During natural leaf senescence urea concentrations and DUR3 transcript levels showed a parallel increase with senescence markers like ORE1 in a plant age- and leaf age-dependent manner. Deletion of DUR3 decreased urea accumulation in leaves, whereas the fraction of urea lost to the leaf apoplast was enhanced. Under natural and N deficiency-induced senescence DUR3 promoter activity was highest in the vasculature, but was also found in surrounding bundle sheath and mesophyll cells. An analysis of petiole exudates from wild-type leaves revealed that N from urea accounted for >13% of amino acid N. Urea export from senescent leaves further increased in ureG-2 deletion mutants lacking urease activity. In the dur3 ureG double insertion line the absence of DUR3 reduced urea export from leaf petioles. These results indicate that urea can serve as an early metabolic marker for leaf senescence, and that DUR3-mediated urea retrieval contributes to the retranslocation of N from urea during leaf senescence.

  14. Radiative properties of argon-helium-nitrogen-carbon-cobalt-nickel plasmas used in CNT synthesis

    Science.gov (United States)

    Salem, D.; Hannachi, R.; Cressault, Y.; Teulet, Ph; Béji, L.

    2015-02-01

    This work presents the radiative properties of argon-helium-nitrogen-carbon-nickel-cobalt thermal plasmas by the computation of net emission coefficients (NECs) under the assumption of a local thermodynamic equilibrium and at temperature range 1000-20 000 K. These mixtures were often used in the study of carbon nanotubes (CNTs) synthesis with arc plasma which becomes one of the most useful techniques in terms of flexibility of carbon nanostructures produced with fewer defects. The values of NEC allow estimation of total radiation losses in plasmas, by taking into account the emission radiation resulting from the atomic continuum, the molecular continuum, the atomic lines and some molecular bands. Free-free transitions (Bremsstrahlung) and free-bound (electron-ion recombination), have been considered for the calculation of atomic continuum. For bound-bound transitions, natural, resonance, Van der Waals, Stark and Doppler effects have been taken into account in the calculation of the lines broadenings while the self-absorption of the resonance lines has been treated using their escape factors. Molecular continuum has been only considered for N2, C2 and CN molecules whereas we have only taken into account diatomic systems N2, \\text{N}2+ , CN and C2 for the emission of the molecular bands. The results obtained show that even for low concentrations of Ni and Co in the plasma, the NECs are modified and considerably increase only at a low temperature (T < 8000 K) and the major contribution in the total radiation arises from the lines emission. However, the effect of the thickness of the plasma on plasma radiation has been analysed based on the self absorption phenomenon of resonance lines.

  15. Behavior of incorporated nitrogen in plasma-nitrided silicon oxide formed by chemical vapor deposition

    Science.gov (United States)

    Shinoda, Nao; Itokawa, Hiroshi; Fujitsuka, Ryota; Sekine, Katsuyuki; Onoue, Seiji; Tonotani, Junichi

    2016-04-01

    The behavior of nitrogen (N) atoms in plasma-nitrided silicon oxide (SiO2) formed by chemical vapor deposition (CVD) was characterized by physical analysis and from electrical properties. The changes in the chemical bonding and distribution of N in plasma-nitrided SiO2 were investigated for different subsequent processes. N-Si3, N-Si2O, and N2 are formed in a SiO2 film by plasma nitridation. N2 molecules diffuse out during annealing at temperatures higher than 900 °C. NH species are generated from N2 molecules and H in the SiO2 film with subsequent oxide deposition using O3 as an oxidant. The capacitance-voltage (C-V) curves of metal-oxide-semiconductor (MOS) capacitors are obtained. The negative shift of the C-V curve is caused by the increase in the density of positive fix charge traps in CVD-SiO2 induced by plasma nitridation. The C-V curve of plasma-nitrided SiO2 subjected to annealing shifts to the positive direction and that subjected to the subsequent oxide deposition shifts markedly to the negative direction. It is clarified that the density of positive charge fixed traps in plasma-nitrided SiO2 films decrease because the amount of N2 molecules is decreased by annealing, and that the density of traps increases because NH species are generated and move to the interface between SiO2 and the Si substrate with the subsequent oxide deposition.

  16. Kinetics of post-treatment structural transformations of nitrogen plasma ion immersion implanted polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Kosobrodova, E., E-mail: elenak@physics.usyd.edu.au; Kondyurin, A.; McKenzie, D.R.; Bilek, M.M.M.

    2013-06-01

    The surface chemistry of a synthetic material in contact with a biological system has a strong influence on the adhesion of proteins to the surface of the material and requires careful consideration in biomedical applications. The structure of plasma immersion ion implantation (PIII) treated polymer and its surface free energy depend on the ion fluence delivered during the treatment and on the time after the PIII treatment. These dependences have been investigated using the example of nitrogen plasma implanted polystyrene (PS). Contact angle measurements, FTIR–ATR spectra and X-ray photoelectron (XPS) spectra were acquired as a function of ion fluence and time after treatment. The results showed a close relationship to the kinetics of free radicals that had been examined in a previous study. The kinetics of oxidation and surface free energy had two stages, one with a characteristic time of several hours and the other with a characteristic time of several days. The concentration of nitrogen-containing groups decreased with time after PIII treatment, partly, due to their release from the PS surface.

  17. Plasma renin activities, angiotensin II concentrations, atrial natriuretic peptide concentrations and cardiopulmonary function values in dogs with severe heartworm disease.

    Science.gov (United States)

    Kitagawa, H; Kitoh, K; Inoue, H; Ohba, Y; Suzuki, F; Sasaki, Y

    2000-04-01

    Relationships among plasma renin activities (PRA), plasma angiotensin II (ATII) concentrations, atrial natriuretic peptide (ANP) concentrations and cardiopulmonary function values were examined in dogs with ascitic pulmonary heartworm disease and acute- and chronic-vena caval syndrome (CS). PRA, plasma ATII concentration and plasma ANP concentration tended to be higher or were significantly higher in dogs with ascites, acute- and chronic-CS. PRA correlated significantly with plasma ATII concentration, WBC count, ALP activity, plasma concentrations of urea nitrogen, creatinine, sodium, potassium, and chloride, right ventricular endodiastolic pressure and right atrial pressure. Plasma ATII concentration correlated significantly with WBC count, plasma concentrations of urea nitrogen, sodium, and potassium, right ventricular endodiastolic pressure and right atrial pressure. Plasma ANP concentration did not correlate with PRA or ATII concentration, but correlated significantly only with pulmonary arterial pressure.

  18. Determination of ammonium and organic bound nitrogen by inductively coupled plasma emission spectroscopy.

    Science.gov (United States)

    Jaber, A M Y; Mehanna, N A; Sultan, S M

    2009-06-15

    The continuous flow sample introduction technique with a hydride generator system in conjunction with an inductively coupled plasma emission spectrometer (ICP-AES-HG), is used in this study for quantitative determination of ammonium and organic bound nitrogen in aqueous and solid samples. Ammonia vapor released from ammonium salt after treatment with concentrated NaOH is transferred by argon to plasma for detection at 174.273 nm using axial argon plasma mode. The calibration curves were linear within a range of 25-1000 mg L(-1)N as ammonium molybdate with correlation coefficients of better than 0.99 and limits of detection of about 10-25mg L(-1)N. The percent recovery of N (25-500 mg L(-1)N) in soft (distilled) water and high salt content (1.7 mol L(-1) NaCl) matrices was found to be in the range of about 97-102% with %RSD in the range of 4.6-0.62. The sensitivity, limit of detection, and blank contribution from the atmospheric nitrogen, were tremendously improved in this method compared with the available ICP-AES spray chamber counterpart. Furthermore, the ICP-AES-HG method gave results for real samples (soil, fertilizer, waste water) containing about 50-1800 mg L(-1)N in good agreement with those obtained by the standard Kjeldahl method. No statistical differences at the 95% confidence level on applying the t-test were observed between the values obtained by the two methods. Thus, the ICP-AES-HG method is reliable and faster than the conventional tedious Kjeldahl method, superior to the ICP-AES spray chamber method, and almost free from matrix interference which is usually a critical factor in atomic emission spectroscopic techniques.

  19. Optimization of nitrogen plasma source parameters by measurements of emitted light intensity for growth of GaN by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Klosek, K.; Sobanska, M.; Tchutchulashvili, G.; Zytkiewicz, Z.R., E-mail: zytkie@ifpan.edu.pl; Teisseyre, H.; Klopotowski, L.

    2013-05-01

    A comprehensive analysis of operating parameters of Addon RF nitrogen plasma source was made in order to determine how a ratio of different active nitrogen species depends on operating parameters of the source such as supplied power and nitrogen flow. We show that output signal of the optical sensor that measures intensity of the light emitted by the plasma is a direct measure of the amount of active nitrogen available for growth. Results of optical emission spectroscopy and measurements of growth kinetics show that nitrogen excited metastable molecules are the species mainly contributing to the growth of GaN under Ga-rich conditions. A procedure is presented allowing to find an optimal conditions of the plasma cell for high-quality GaN growth. Under these conditions the nitrogen flux contains maximum amount of excited metastable molecules and minimal amount of ionic and atomic nitrogen species to minimize GaN lattice damage, even at high growth rates. - Highlights: ► Operating parameters of Addon radio-frequency nitrogen plasma source studied ► Their influence on molecular beam epitaxy (MBE) growth of GaN analyzed ► MBE growth rate of GaN well correlates with output of the plasma emission sensor. ► Optical emission spectroscopy measurements of the nitrogen plasma made ► Nitrogen excited molecules mainly contribute to plasma-assisted MBE growth of GaN.

  20. Uréia para vacas leiteiras no pós-parto: teor plasmático de uréia e pH uterino Urea for dairy cows in the postpartum: urea levels in the plasma and uterine pH

    Directory of Open Access Journals (Sweden)

    Margarida Maria Nascimento Figueiredo de Oliveira

    2004-02-01

    Full Text Available O objetivo deste trabalho foi verificar os efeitos de níveis crescentes de uréia nas dietas de vacas leiteiras no pós-parto sobre os teores plasmáticos de N-uréia (NUP e o pH uterino no estro e na fase luteal. Utilizaram-se dezesseis vacas mestiças (Holandês-zebu com escore corporal ao parto entre 3,5 e 4,0 (escala 1 a 5, que foram alocadas em quatro tratamentos constituídos de dietas contendo volumoso (silagem de milho e concentrado, na proporção 60:40: T1 = 0,0; T2 = 0,7; T3 = 1,4; e T4 = 2,1% de uréia na matéria seca total. No estro e na fase luteal, do segundo ou terceiro ciclo estral pós-parto, realizou-se a medição do pH uterino quatro horas após o fornecimento da dieta e; simultaneamente foram coletadas amostras de sangue para determinação dos teores plasmáticos de uréia. A ingestão de matéria seca dos 70 aos 110 dias de lactação reduziu a partir do nível 0,7% de uréia e a produção de leite não foi influenciada pelos níveis de uréia das dietas. Não houve influência dos níveis de uréia sobre os teores plasmáticos de N-uréia, em amostras de sangue coletadas no estro, que foram, em média, de 19,59 mg/dL. O pH uterino no estro (6,66 e na fase luteal (6,97 também não foi influenciado pelos diferentes níveis de uréia nas dietas.The objective of this work was to evaluate the effects of increasing levels of urea in the diets in postpartum crossbred dairy cows on plasma level of N-urea (NUP and uterine pH in the estrus and luteal phase. Sixteen crossbred cows (Holstein-zebu with body condition score at parturition between 3.5 and 4.0 (1 to 5 scale were assigned in four treatments with diets made up with corn silage and concentrate in the proportion of 60:40 as: T1=0.0; T2=0.7; T3=1.4; and T4=2.1% of urea in the dry matter. The uterine pH was measured four hours after the diet intake, during the estrus and luteal phase from the second or third estrous cycle postpartum period in dairy cows. Simultaneously

  1. Impact of nitrogen plasma passivation on the Al/n-Ge contact

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Shumei; Mao, Danfeng [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Ruan, Yujiao [Xiamen Institute of Measurement and Testing, Xiamen, Fujian 361004 (China); Xu, Yihong; Huang, Zhiwei; Huang, Wei [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Chen, Songyan, E-mail: sychen@xmu.edu.cn [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Li, Cheng; Wang, Jianyuan [Department of Physics, Xiamen University, Xiamen, Fujian 361005 (China); Tang, Dingliang [College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005 (China)

    2016-09-15

    Highlights: • A thin GeO{sub x}N{sub y} layer was formed by N{sub 2} plasma. • The principal parameters of N{sub 2} plasma treatment and additional post anneal have a great impact on the Al/n-Ge contact. • A model was proposed to explain the variation of Schottky barrier height. • The GeO{sub x}N{sub y} layer was also benefit to achieve a low leakage current density for HfO{sub 2}/Ge MOS capacitors. - Abstract: Severe Fermi level pinning at the interface of metal/n-Ge leads to the formation of a Schottky barrier. Therefore, a high contact resistance is introduced, debasing the performance of Ge devices. In this study, a Ge surface was treated by nitrogen plasma to form an ultra-thin Germanium oxynitride (GeO{sub x}N{sub y}) passivation layer. It was found that the Schottky barrier height (SBH) of metal/n-Ge contact was strongly modulated by the GeO{sub x}N{sub y} interlayer, indicating alleviation of Fermi-level pinning effect. By adjusting the principal parameters of N{sub 2} plasma treatment and additional post anneal, a Quasi-ohmic Al/n-Ge contact was achieved. Furthermore, the introduced GeO{sub x}N{sub y} layer gave extremely lower leakage current density of the gate stack for HfO{sub 2}/Ge devices. These results demonstrate that GeO{sub x}N{sub y} formed by N{sub 2} plasma would be greatly beneficial to the fabrication of the Ge-based devices.

  2. Hereditary urea cycle abnormality

    Science.gov (United States)

    ... vitro so the specific genetic cause is known. Teamwork between parents, the affected child, and doctors can help prevent severe illness. Alternative Names Abnormality of the urea cycle - hereditary; Urea cycle - hereditary abnormality Images Male urinary system Urea cycle References Lichter-Konecki ...

  3. Plasma cleaning: A new possible treatment for niobium superconducting cavity after nitrogen doping

    CERN Document Server

    Yang, Ziqin; Xie, Datao; Lin, Lin; Zhou, Kui; Zhao, Jifei; Yang, Deyu; Tan, Weiwei

    2015-01-01

    Nitrogen doping treatment with the subsequent electropolishing (EP) of the niobium superconducting cavity can significantly increase the cavity's quality factor up to a factor of 3. But the process of the EP removal may reintroduce hydrogen in the cavity surface, which may influence the cavity's radio frequency performance. Plasma cleaning study on niobium samples with gas mixtures of argon and oxgen intended to remove contaminations (hydrocarbons and micronicdust particles) from cavity surface to avoid field emission, was performed in Peking University. The niobium samples have been analyzed using the time of flight secondary ion mass spectrometry (TOF-SIMS) to measure the depth profiles of H, C, O, F, P and Nb. The measuring results show that the plasma cleaning with gas mixtures of argon and oxgen and conditions of about 20Pa and 100W can remarkably reduce the contents of impurity elements in the depth of about 30 nm without introducing hydrogen in the cavity surface. So plasma cleaning has been proposed t...

  4. Ammonia volatilization from coated urea forms

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Costa do Nascimento

    2013-08-01

    Full Text Available Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N volatilization losses in sugar cane harvested after stubble burning. The sources urea, sulfur-coated urea, urea coated with boric acid and copper sulfate, as well as nitrate and ammonium sulfate, were tested at amounts containing N rates of 120 kg ha-1 N. The integration of new technologies in urea fertilization can reduce N losses by volatilization. These losses were most reduced when using nitrate and ammonium sulfate. The application of a readily acidified substance (boric acid to urea was more efficient in reducing volatilization losses and nutrient removal by sugar cane than that of a substance with gradual acidification (elemental sulfur.

  5. Improved Cd determination in glasses by laser ablation inductively coupled plasma mass spectrometry using nitrogen as a matrix modifier

    Institute of Scientific and Technical Information of China (English)

    Qian Ni; Zhao Chu Hu; Zheng Yu Bao; Ya Feng Zhang

    2009-01-01

    The addition of 5-10 mL min-1 nitrogen to the central channel of plasma in Laser ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) increases the sensitivities of Cd by a factor of 3 and decreases oxide interferences by one order of magnitude, which allows the direct analysis of trace levels of Cd in glass samples. This simple method shows a great potential for the direct determination of Cd in various kinds of samples.

  6. Investigation of the efficacy of 99 mTc-DTPA scintigraphic GFR measurement with Gates method in the detection of cisplatin-induced nephrotoxicity in comparison with plasma urea and creatinine measurement.

    Science.gov (United States)

    Özülker, Filiz; Özülker, Tamer; Uzun, Aysun Küçüköz; Özpaçacı, Tevfik

    2011-12-01

    In this study, we investigated the efficacy of 99mTc-DTPA scintigraphic analysis of GFR with the Gates method in comparison with the measurement of plasma urea and creatinine, in the detection of nephrotoxicity occurred in patients treated with cisplatin.Twenty-six male patients with a mean age of 26.73±6.39 years (age range 15-42) who had seminomatous and nonseminomatous testicular carcinoma were included in our study. The patients received cisplatin with a dose of 20 mg/m2 per day for five consecutive days repeated every 21 days. Before starting chemotherapy, immediately after the end of four cycles of chemotherapy and 7 months after the beginning of chemotherapy, plasma urea and creatinine levels were measured and simultaneously scintigraphic GFR estimation using 99 mTc-DTPA with the Gates method was performed. In the measurements done immediately after the chemotherapy, in 18 of the 26 patients GFR levels decreased, in 4 of the 8 remaining patients GFR did not change, and in 4 patients there was an increase in the GFR levels. The changes in the averages of the plasma urea and creatinine levels between measurements done before and after the chemotherapy were not statistically significant. The decrease in the average of the GFR values immediately after chemotherapy, in comparison to the average of GFR values measured before chemotherapy, was found to be statistically significant with paired sample t test analysis (PGFR measurement using the Gates method with 99mTc-DTPA is a suitable method in the diagnosis of nephrotoxicity occuring due to cisplatine.

  7. Langmuir probe diagnostics of an atmospheric pressure, vortex-stabilized nitrogen plasma jet

    Energy Technology Data Exchange (ETDEWEB)

    Prevosto, L.; Mancinelli, B. R. [Grupo de Descargas Electricas, Departamento Ingenieria Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, (2600) Venado Tuerto, Santa Fe (Argentina); Kelly, H. [Grupo de Descargas Electricas, Departamento Ingenieria Electromecanica, Facultad Regional Venado Tuerto (UTN), Laprida 651, (2600) Venado Tuerto, Santa Fe (Argentina) and Instituto de Fisica del Plasma (CONICET), Departamento de Fisica, Facultad de Ciencias Exactas y Naturales UBA Ciudad Universitaria Pab. I, (1428) Buenos Aires (Argentina)

    2012-09-15

    Langmuir probe measurements in an atmospheric pressure direct current (dc) plasma jet are reported. Sweeping probes were used. The experiment was carried out using a dc non-transferred arc torch with a rod-type cathode and an anode of 5 mm diameter. The torch was operated at a nominal power level of 15 kW with a nitrogen flow rate of 25 Nl min{sup -1}. A flat ion saturation region was found in the current-voltage curve of the probe. The ion saturation current to a cylindrical probe in a high-pressure non local thermal equilibrium (LTE) plasma was modeled. Thermal effects and ionization/recombination processes inside the probe perturbed region were taken into account. Averaged radial profiles of the electron and heavy particle temperatures as well as the electron density were obtained. An electron temperature around 11 000 K, a heavy particle temperature around 9500 K and an electron density of about 4 Multiplication-Sign 10{sup 22} m{sup -3}, were found at the jet centre at 3.5 mm downstream from the torch exit. Large deviations from kinetic equilibrium were found throughout the plasma jet. The electron and heavy particle temperature profiles showed good agreement with those reported in the literature by using spectroscopic techniques. It was also found that the temperature radial profile based on LTE was very close to that of the electrons. The calculations have shown that this method is particularly useful for studying spraying-type plasma jets characterized by electron temperatures in the range 9000-14 000 K.

  8. Removal of Nitrogen Oxides in Diesel Engine Exhaust by Plasma Assisted Molecular Sieves

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper reports the studies conducted on removal of oxides of nitrogen (NOx) from diesel engine exhaust using electrical discharge plasma combined with adsorbing materials such as molecular sieves. This study is being reported for the first time. The exhaust is taken from a diesel engine of 6 kW under no load conditions. The characteristic behavior of a pulse energized dielectric barrier discharge reactor in the diesel exhaust treatment is reported. The NOx removal was not significant (36%) when the reactor without any packing was used. However, when the reactor was packed with molecular sieves (MS -3A, -4A & -13X), the NOx removal efficiency was increased to 78% particularly at a temperature of 200 o C. The studies were conducted at different temperatures and the results were discussed.

  9. The effect of atmosphere composition in plasma nitrogenation of Sm2Fe17

    Science.gov (United States)

    Ardisson, J. D.; Araujo, R. C.; Macedo, W. A. A.; Persiano, A. I. C.; Gama, S.

    2004-05-01

    The change on the structural and magnetic properties of the Sm2Fe17 compound as the ratio of H2/N2 forming the mixture of the atmosphere in a plasma chamber used to nitride this compound varied, was investigated by Mössbauer spectroscopy and X-ray diffraction. Our results show that the increase of the hydrogen concentration in the mixed H2/N2 atmosphere reduces the formation of the nitrogen-rich phases, Sm2Fe17N8 and Sm2Fe17N11 and increases the formation of the Sm2Fe17N3 phase, whose maximum values are obtained for 70% H2 in the gas mixture.

  10. Plasma nitrogenation of Pr2Fe17 and Sm2Fe17

    Science.gov (United States)

    Ardisson, Jose D.; Macedo, Waldemar A. A.; Araujo, Roberto C.; Gama, Sergio

    2000-05-01

    The effect of plasma nitrogenation on the structural and magnetic properties of Pr2Fe17 and Sm2Fe17 compounds was investigated by Mössbauer spectroscopy, thermomagnetic measurements, optical metallography, and electronic microprobe analysis. Samples were prepared starting from Pr2Fe17 and Sm2Fe17 commercial powders with 20 μm granulometry, submitted to nitrogenation treatment at 400 °C in 10 Torr atmosphere of 80%H2-20%N2 during periods up to 8 h. Our results show the formation of R2Fe17N3 and metallic Fe and indicate the existence of two other phases. The Mössbauer parameters of the latter are characterized by magnetic hyperfine fields (peak values) of 21 (24) and 3 (4) T and isomer shifts of 0.17 and 0.24 (0.24 and 0.29) mm/s for Pr (Sm). Their magnetic-phase transitions were determined to be close to 250 and 90 °C. Our results suggest that these 2:17 phases present stoichiometries close to R2Fe17N8 and R2Fe17N11, respectively.

  11. Nitrogen-Doped Carbon Fiber Paper by Active Screen Plasma Nitriding and Its Microwave Heating Properties.

    Science.gov (United States)

    Zhu, Naishu; Ma, Shining; Sun, Xiaofeng

    2016-12-28

    In this paper, active screen plasma nitriding (ASPN) treatment was performed on polyacrylonitrile carbon fiber papers. Electric resistivity and microwave loss factor of carbon fiber were described to establish the relationship between processing parameters and fiber's ability to absorb microwaves. The surface processing effect of carbon fiber could be characterized by dynamic thermal mechanical analyzer testing on composites made of carbon fiber. When the process temperature was at 175 °C, it was conducive to obtaining good performance of dynamical mechanical properties. The treatment provided a way to change microwave heating properties of carbon fiber paper by performing different treatment conditions, such as temperature and time parameters. Atomic force microscope, scanning electron microscope, and X-ray photoelectron spectroscopy analysis showed that, during the course of ASPN treatment on carbon fiber paper, nitrogen group was introduced and silicon group was removed. The treatment of nitrogen-doped carbon fiber paper represented an alternative promising candidate for microwave curing materials used in repairing and heating technology, furthermore, an efficient dielectric layer material for radar-absorbing structure composite in metamaterial technology.

  12. Balanço de nitrogênio, concentrações de ureia e síntese de proteína microbiana em caprinos alimentados com dietas contendo cana-de-açúcar tratada com óxido de cálcio Nitrogen balance, urea concentrations and microbial protein synthesis in goats fed diets containing sugar cane treated with calcium oxide

    Directory of Open Access Journals (Sweden)

    Gleidson Giordano Pinto de Carvalho

    2010-10-01

    Full Text Available Objetivou-se avaliar o efeito da hidrólise da cana-de-açúcar com óxido de cálcio (CaO sobre o balanço de nitrogênio, as concentrações de ureia na urina e no plasma e a síntese na proteína microbiana em caprinos. Foram utilizados oito caprinos da raça Saanen, machos castrados, com peso corporal médio de 22,6 kg e 4 meses de idade, distribuídos em dois quadrados latinos 4 õ 4, em quatro períodos experimentais de 14 dias. As rações, formuladas para ser isoproteicas, com 14% de proteína bruta (PB, foram compostas de 70% de cana-de-açúcar (tratada com 0; 0,75; 1,5 ou 2,25% de óxido de cálcio na matéria natural e corrigida com 1% de ureia e 30% de concentrado e fornecidas à vontade. A cana-de-açúcar com óxido de cálcio foi picada em desintegrador estacionário, pesada, acondicionada em baldes plásticos de 50 litros e tratada com o óxido de cálcio para ser fornecida aos animais após 24 horas de armazenamento. O balanço de nitrogênio, as concentrações de ureia na urina e no plasma e as excreções de ureia na urina não foram influenciadas pelo tratamento da cana-de-açúcar com óxido de cálcio. A concentração de alantoína (% das purinas totais foi maior e a de ácido úrico menor nas dietas com cana-de-açúcar hidrolisada com óxido de cálcio em relação à cana in natura. A produção e a eficiência microbiana não foram afetadas pela adição de óxido de cálcio à cana-de-açúcar em dietas para caprinos em crescimento.The objective of this work was to evaluate the effect of sugar cane hydrolysis with calcium oxide (CaO on nitrogen balance, concetrations of urea in the urine and in the plasma and synthesis in microbial protein in goats. Eight castrated male Saanen breed goats, with 22.6 kg average body weight and at four months of age were used distributed in two 4 õ 4 Latin squares, during four 14-day experimental periods. The rations which were formulated to be isoprotein, with 14% crude protein (CP

  13. Chemical sputtering of graphite by low temperature nitrogen plasmas at various substrate temperatures and ion flux densities

    NARCIS (Netherlands)

    Bystrov, K.; Morgan, T. W.; Tanyeli, I.; De Temmerman, G.; M. C. M. van de Sanden,

    2013-01-01

    We report measurements of chemical sputtering yields of graphite exposed to low temperature nitrogen plasmas. The influence of surface temperature and incoming ion energy on the sputtering yields has been investigated in two distinct ion flux density regimes. Sputtering yields grow consistently with

  14. Covalent Nitrogen Doping and Compressive Strain in MoS2 by Remote N2 Plasma Exposure.

    Science.gov (United States)

    Azcatl, Angelica; Qin, Xiaoye; Prakash, Abhijith; Zhang, Chenxi; Cheng, Lanxia; Wang, Qingxiao; Lu, Ning; Kim, Moon J; Kim, Jiyoung; Cho, Kyeongjae; Addou, Rafik; Hinkle, Christopher L; Appenzeller, Joerg; Wallace, Robert M

    2016-09-14

    Controllable doping of two-dimensional materials is highly desired for ideal device performance in both hetero- and p-n homojunctions. Herein, we propose an effective strategy for doping of MoS2 with nitrogen through a remote N2 plasma surface treatment. By monitoring the surface chemistry of MoS2 upon N2 plasma exposure using in situ X-ray photoelectron spectroscopy, we identified the presence of covalently bonded nitrogen in MoS2, where substitution of the chalcogen sulfur by nitrogen is determined as the doping mechanism. Furthermore, the electrical characterization demonstrates that p-type doping of MoS2 is achieved by nitrogen doping, which is in agreement with theoretical predictions. Notably, we found that the presence of nitrogen can induce compressive strain in the MoS2 structure, which represents the first evidence of strain induced by substitutional doping in a transition metal dichalcogenide material. Finally, our first principle calculations support the experimental demonstration of such strain, and a correlation between nitrogen doping concentration and compressive strain in MoS2 is elucidated.

  15. Cobalt and iron segregation and nitride formation from nitrogen plasma treatment of CoFeB surfaces

    Science.gov (United States)

    Mattson, E. C.; Michalak, D. J.; Veyan, J. F.; Chabal, Y. J.

    2017-02-01

    Cobalt-iron-boron (CoFeB) thin films are the industry standard for ferromagnetic layers in magnetic tunnel junction devices and are closely related to the relevant surfaces of CoFe-based catalysts. Identifying and understanding the composition of their surfaces under relevant processing conditions is therefore critical. Here we report fundamental studies on the interaction of nitrogen plasma with CoFeB surfaces using infrared spectroscopy, x-ray photoemission spectroscopy, and low energy ion scattering. We find that, upon exposure to nitrogen plasma, clean CoFeB surfaces spontaneously reorganize to form an overlayer comprised of Fe2N3 and BN, with the Co atoms moved well below the surface through a chemically driven process. Subsequent annealing to 400 °C removes nitrogen, resulting in a Fe-rich termination of the surface region.

  16. Efficacy of β-mannanase supplementation to corn-soya bean meal-based diets on growth performance, nutrient digestibility, blood urea nitrogen, faecal coliform and lactic acid bacteria and faecal noxious gas emission in growing pigs.

    Science.gov (United States)

    Upadhaya, Santi Devi; Park, Jae Won; Lee, Jae Hwan; Kim, In Ho

    2016-01-01

    A study was conducted to determine the efficacy of β-mannanase supplementation to a diet based on corn and soya bean meal (SBM) on growth performance, nutrient digestibility, blood urea nitrogen (BUN), faecal coliforms and lactic acid bacteria, and noxious gas emission in growing pigs. A total of 140 pigs [(Landrace × Yorkshire) × Duroc; average body weight 25 ± 3 kg] were randomly allotted to a 2 × 2 factorial arrangement with dietary treatments consisting of hulled or dehulled SBM without or with supplementation of 400 U β-mannanase/kg. During the 6 weeks of experimental feeding, β-mannanase supplementation had no effect on body weight gain, feed intake and gain:feed (G:F) ratio. Compared with dehulled SBM, feeding hulled SBM caused an increased feed intake of pigs in the entire trial (p = 0.05). The G:F ratio was improved in pigs receiving dehulled SBM (p < 0.05). Dietary treatments did not influence the total tract digestibility of dry matter, nitrogen and gross energy. Enzyme supplementation reduced (p < 0.05) the population of faecal coliforms and tended to reduce the NH3 concentration after 24 h of fermentation in a closed box containing faecal slurry. Feeding hulled SBM tended to reduce NH3 emission on days 3 and 5 of fermentation. In conclusion, mannanase supplementation had no influence on growth performance and nutrient digestibility but showed a positive effect on reducing coliform population and tended to reduce NH3 emission. Dehulled SBM increased G:F ratio and hulled SBM tended to reduce NH3 emission.

  17. Effect of increasing the dietary tryptophan to lysine ratio on plasma levels of tryptophan, kynurenine and urea and on production traits in weaner pigs experimentally infected with an enterotoxigenic strain of Escherichia coli.

    Science.gov (United States)

    Capozzalo, Meeka M; Kim, Jae Cheol; Htoo, John K; de Lange, Cornelius F M; Mullan, Bruce P; Hansen, Christian Fink; Resink, Jan-Willem; Stumbles, Phillip A; Hampson, David J; Pluske, John R

    2015-01-01

    This experiment examined if immune system stimulation of weaner pigs, initiated by inoculation an enterotoxigenic strain of Escherichia coli (ETEC), increased the requirement for dietary tryptophan (Trp), modulated the inflammatory response, altered plasma levels of Trp and its metabolite kynurenine (Kyn) and effected post-weaning diarrhoea. Individually housed pigs (n = 72) weaned at 21 d of age were allocated to one of six treatments (n = 12) according to a two by three factorial arrangement of (1) with or without ETEC infection and (2) three dietary ratios of standardised ileal digestible (SID) Trp to lysine (Lys) (SID Trp:Lys) of 0.16, 0.20 or 0.24, in a completely randomised block design. Pigs had ad libitum access to diets (per kg 14.13 MJ ME, 12.4 g SID Lys, 195 g crude protein) for 3 weeks after weaning. Pigs were infected with ETEC (O149:K98:K88) at 72, 96 and 120 h after weaning and then bled on day 3, 11 and 19. An increased dietary Trp:Lys ratio increased plasma Trp and Kyn (p pigs fed 0.24 SID Trp:Lys had lower levels of plasma urea than at 0.20 Trp:Lys (p = 0.047) and on day 11, plasma urea was lower at 0.20 than at 0.16 SID Trp:Lys (p = 0.007). Infection increased (p = 0.039) the diarrhoea index and deteriorated faecal consistency from day 4-10 (p dietary antibiotic growth promotants, increasing the dietary SID Trp:Lys ratio to 0.24 improved feed conversion ratio after weaning and increased plasma levels of Trp and Kyn regardless of infection with E. coli.

  18. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor

    Science.gov (United States)

    Talebizadeh, Pouyan; Rahimzadeh, Hassan; Babaie, Meisam; Javadi Anaghizi, Saeed; Ghomi, Hamidreza; Ahmadi, Goodarz; Brown, Richard

    2015-01-01

    Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode. PMID:26496630

  19. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor.

    Directory of Open Access Journals (Sweden)

    Pouyan Talebizadeh

    Full Text Available Non-thermal plasma (NTP has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode.

  20. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor.

    Science.gov (United States)

    Talebizadeh, Pouyan; Rahimzadeh, Hassan; Babaie, Meisam; Javadi Anaghizi, Saeed; Ghomi, Hamidreza; Ahmadi, Goodarz; Brown, Richard

    2015-01-01

    Non-thermal plasma (NTP) has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode.

  1. Balanço de compostos nitrogenados e produção de proteína microbiana em novilhas leiteiras alimentadas com palma forrageira, bagaço de cana-de-açúcar e uréia associados a diferentes suplementos Nitrogenous compounds balance and microbial protein production in crossbred heifers fed forage cactus, sugar cane bagasse and urea associated to different supplements

    Directory of Open Access Journals (Sweden)

    Ricardo Alexandre Silva Pessoa

    2009-05-01

    Full Text Available Objetivou-se avaliar o efeito da associação de palma forrageira ao bagaço de cana-de-açúcar e à uréia sobre o balanço de compostos nitrogenados e a produção de proteína microbiana em novilhas leiteiras recebendo ou não suplemento. Foram utilizadas 25 novilhas da raça Girolando, com peso vivo médio inicial de 227 kg, confinadas, distribuídas em delineamento experimental de blocos ao acaso, estabelecidos de acordo com o peso dos animais. A ração controle (sem suplemento foi composta de 64,0% de palma forrageira, 30,0% de bagaço de cana-de-açúcar, 4,0% de mistura uréia:sulfato de amônio (9:1 e 2,0% de mistura mineral, com base na matéria seca (MS, e as rações experimentais, de 57,0% de palma forrageira, 26,0% de bagaço de cana-de-açúcar, 3,5% de mistura uréia:sulfato de amônio, 1,8% de mistura mineral e 11,7% de suplemento (0,5% do PV dos animais. Os suplementos testados foram: farelo de trigo, farelo de soja, farelo de algodão ou caroço de algodão. O balanço de nitrogênio não foi influenciado pelas dietas e apresentou valor médio de 49,3 g/dia. A suplementação com farelo de algodão ou com farelo de soja aumentou a excreção de nitrogênio na urina, a concentração de uréia e nitrogênio uréico no plasma e a excreção urinária de uréia e nitrogênio uréico. A associação da palma forrageira ao bagaço de cana-de-açúcar e à uréia, sem o uso de suplementos, permite eficiência de síntese microbiana de 105 gPBmic/kg de NDT consumido. A suplementação com caroço de algodão proporciona maior excreção urinária de alantoína e derivados de purina e melhor eficiência de síntese microbiana, portanto, é a mais indicada nestas condições.The objective of this work was to evaluate the effect of association of forage cactus to sugar cane bagasse and urea on nitrogenous compounds balance and microbial protein synthesis in milk heifers supplemented or not. Twenty-five Holstein-Gir crossbred heifers

  2. Quasi-monoenergetic electron beams from a few-terawatt laser driven plasma acceleration using a nitrogen gas jet

    Science.gov (United States)

    Rao, B. S.; Moorti, A.; Chakera, J. A.; Naik, P. A.; Gupta, P. D.

    2017-06-01

    An experimental investigation on the laser plasma acceleration of electrons has been carried out using 3 TW, 45 fs duration titanium sapphire laser pulse interaction with a nitrogen gas jet at an intensity of 2 × 1018 W cm-2. We have observed the stable generation of a well collimated electron beam with divergence and pointing variation ˜10 mrad from nitrogen gas jet plasma at an optimum plasma density around 3 × 1019 cm-3. The energy spectrum of the electron beam was quasi-monoenergetic with an average peak energy and a charge around 25 MeV and 30 pC respectively. The results will be useful for better understanding and control of ionization injection and the laser wakefield acceleration (LWFA) of electrons in high-Z gases and also towards the development of practical LWFA for various applications including injectors for high energy accelerators.

  3. Comparison of amino acid oxidation and urea metabolism in haemodialysis patients during fasting and meal intake

    NARCIS (Netherlands)

    Veeneman, JM; Kingma, HA; Stellaard, F; de Jong, PE; Reijngoud, DJ; Huisman, RM

    2004-01-01

    Background. The PNA (protein equivalent of nitrogen appearance) is used to calculate protein intake from urea kinetics. One of the essential assumptions in the calculation of PNA is that urea accumulation in haemodialysis (HD) patients is equivalent to amino acid oxidation. However, urea is hydrolys

  4. Synthesis and Performance of Polyurethane Coated Urea as Slow/controlled Release Fertilizer

    Institute of Scientific and Technical Information of China (English)

    LI Qingshan; WU Shu; RU Tiejun; WANG Limin; XING Guangzhong; WANG Jinming

    2012-01-01

    Polyurethane coated urea slow/controlled release fertilizer was prepared based on urea granules,isocyanate,polyols and paraffin.Isocyanate reacted with polyols to synthesize the polyurethane skin layer on urea granules surface.Paraffin serves as a lubricant during syntheses of polyurethane skin layers.The structure and nutrient release characteristics of the polyurethane skin layers were investigated by FTIR,SEM and TG.Urea nitrogen slow-release behavior of the polyurethane coated urea was tested.The experimental results indicated that compact and dense polyurethane skin layers with a thickness of 10-15 μm were formed on urea surface,the urea nitrogen slow-release time can reach 40-50 days.Paraffin proves to play a key role in inhibiting water to penetrate into urea,but excessive addition would decrease the polyurethane crosslinking density.

  5. The quenching effect of hydrogen on the nitrogen in metastable state in atmospheric-pressure N{sub 2}-H{sub 2} microwave plasma torch

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shou-Zhe, E-mail: lisz@dlut.edu.cn; Zhang, Xin; Chen, Chuan-Jie; Zhang, Jialiang [Key Laboratory of Materials Modification by Laser, Ion, Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); School of Physics and Optoelectronic Technology, Dalian 116024 (China); Wang, Yong-Xing [College of Electrical Engineering, Dalian 116024 (China); Xia, Guang-Qing [School of Aeronautics and Astronautics, Dalian University of Technology, Dalian 116024 (China)

    2014-07-15

    The atmospheric-pressure microwave N{sub 2}-H{sub 2} plasma torch is generated and diagnosed by optical emission spectroscopy. It is found that a large amount of N atoms and NH radicals are generated in the plasma torch and the emission intensity of N{sub 2}{sup +} first negative band is the strongest over the spectra. The mixture of hydrogen in nitrogen plasma torch causes the morphology of the plasma discharge to change with appearance that the afterglow shrinks greatly and the emission intensity of N{sub 2}{sup +} first negative band decreases with more hydrogen mixed into nitrogen plasma. In atmospheric-pressure microwave-induced plasma torch, the hydrogen imposes a great influence on the characteristics of nitrogen plasma through the quenching effect of the hydrogen on the metastable state of N{sub 2}.

  6. Helicon Discharge with Selectable Nitrogen Reactive Species Production as a Plasma Source for III-group Nitrides Growth by MBE

    Science.gov (United States)

    Biloiu, Costel; Doss, Forest; Scime, Earl

    2004-11-01

    Plasma assisted molecular beam epitaxy (PAMBE) of III-N materials is a potential alternative to MOCVD for fabrication of high quality wide band gap semiconductor devices. In the helicon plasma source, it may be possible to control the population of specific reactive nitrogen species by modification of the electron energy distribution function through the resonant wave-particle interaction arising from electrons traveling at same velocity as the helicon wave phase velocity. We report preliminary results on control of reactive nitrogen species performed in a steady state, high density, helicon plasma source CHEWIE (Compact HElicon Waves and Instabilities Experiment). The helicon vacuum chamber is a 12 cm long, Pyrex tube, 6 cm in diameter, connected to a stainless steel diffusion chamber. RF power of up to 1.0 kW over a frequency range of 3-28 MHz is used to create the steady state plasma. A 7 cm long, half wave, m = +1, helical antenna couples the rf energy into the plasma. A single solenoidal magnetic field coil surrounds the source and is capable of generating axial magnetic fields up to 600 G. Optical emission spectroscopy investigations show that under certain conditions, the decay from the long lived A^3Σ_u^+ state dominates the emission spectrum of the plasma.

  7. A model based on equations of kinetics to study nitrogen dioxide behavior within a plasma discharge reactor.

    Science.gov (United States)

    Abedi-Varaki, Mehdi; Ganjovi, Alireza; Shojaei, Fahimeh; Hassani, Zahra

    2015-01-01

    In this work, a zero-dimensional kinetics model is used to study the temporal behavior of different species such as charged particles, radicals and excited states inside a Dielectric Barrier Discharge plasma reactor. It is shown that, the reactor significantly reduces the concentration of nitrogen monoxide as an environmental pollutant. After a drastic increase, a decrease in the concentration of the NO2 molecules inside the reactor is seen. Nitrogen monoxide molecules with a very low concentration are produced inside the reactor and its quick conversion to other products is proved. The obtained results are compared with the existing experimental and simulation findings, whenever possible.

  8. Comparative studies on the mineralization of furfural urea and urea ...

    African Journals Online (AJOL)

    Comparative studies on the mineralization of furfural urea and urea fertilizers in ... conducted to evaluate the effects of furfural urea as a slow release N fertilizer in ... The controlled or slow availability supplies N continuously over an extended ...

  9. A forma de aplicação da uréia e dos resíduos vegetais afeta a disponibilidade de nitrogênio The addition form of crop residues and urea interfers on nitrogen availability

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Ernani

    2005-04-01

    Full Text Available O método de aplicação dos resíduos vegetais e dos fertilizantes nitrogenados pode afetar as reações do nitrogênio no solo, principalmente no plantio direto. O presente trabalho objetivou avaliar esses efeitos na disponibilidade de N para o milho em dois solos, em casa-de-vegetação. Combinações de métodos (ausência, incorporada ou na superfície de adição de palha de aveia (0,4kg m-2 e uréia (50mg N kg-1 foram aplicadas em unidades experimentais (7dm³ vaso-1 de dois solos, perfazendo um fatorial 3 x 3 x 2. O milho foi semeado no dia da aplicação dos tratamentos e as plantas foram cultivadas durante trinta dias, sobre um Neossolo e um Nitossolo, respectivamente com 50 e 520g kg-1 de argila e 8 e 48g kg-1 de matéria orgânica. A aplicação de palha de aveia, principalmente sobre a superfície do solo, beneficiou o desenvolvimento das plantas, possivelmente pela manutenção de maior quantidade de umidade nos solos. A aplicação de uréia não afetou nenhum parâmetro vegetal no solo argiloso, talvez porque a decomposição da matéria orgânica liberou mais N do que a imobilização ocasionada durante a decomposição da palha; no solo arenoso, entretanto, a uréia foi benéfica quando incorporada ao solo, e prejudicial quando adicionada na superfície, provavelmente devido à toxidez de amônia. Dessa forma, o efeito da decomposição da palha de aveia na disponibilidade de N foi função do teor de matéria orgânica original do solo.Management of both crop residues and nitrogen fertilizers affects soil N reactions especially on no-till systems. The magnitude of these effects on N availability to maize was evaluated in a greenhouse study. Combinations of oat straw and urea (absence, soil incorporated or surface applied were added to experimental units (7-dm³ per pot of two soils, in a 3 x 3 x 2 factorial combination. Plants were sown just following treatments addition, and grown for thirty days in two soils (Typic

  10. Microwave Plasma-Activated Chemical Vapor Deposition of Nitrogen-Doped Diamond. II: CH4/N2/H2 Plasmas.

    Science.gov (United States)

    Truscott, Benjamin S; Kelly, Mark W; Potter, Katie J; Ashfold, Michael N R; Mankelevich, Yuri A

    2016-11-03

    We report a combined experimental and modeling study of microwave-activated dilute CH4/N2/H2 plasmas, as used for chemical vapor deposition (CVD) of diamond, under very similar conditions to previous studies of CH4/H2, CH4/H2/Ar, and N2/H2 gas mixtures. Using cavity ring-down spectroscopy, absolute column densities of CH(X, v = 0), CN(X, v = 0), and NH(X, v = 0) radicals in the hot plasma have been determined as functions of height, z, source gas mixing ratio, total gas pressure, p, and input power, P. Optical emission spectroscopy has been used to investigate, with respect to the same variables, the relative number densities of electronically excited species, namely, H atoms, CH, C2, CN, and NH radicals and triplet N2 molecules. The measurements have been reproduced and rationalized from first-principles by 2-D (r, z) coupled kinetic and transport modeling, and comparison between experiment and simulation has afforded a detailed understanding of C/N/H plasma-chemical reactivity and variations with process conditions and with location within the reactor. The experimentally validated simulations have been extended to much lower N2 input fractions and higher microwave powers than were probed experimentally, providing predictions for the gas-phase chemistry adjacent to the diamond surface and its variation across a wide range of conditions employed in practical diamond-growing CVD processes. The strongly bound N2 molecule is very resistant to dissociation at the input MW powers and pressures prevailing in typical diamond CVD reactors, but its chemical reactivity is boosted through energy pooling in its lowest-lying (metastable) triplet state and subsequent reactions with H atoms. For a CH4 input mole fraction of 4%, with N2 present at 1-6000 ppm, at pressure p = 150 Torr, and with applied microwave power P = 1.5 kW, the near-substrate gas-phase N atom concentration, [N]ns, scales linearly with the N2 input mole fraction and exceeds the concentrations [NH]ns, [NH2]ns

  11. Excretory nitrogen metabolism in the juvenile axolotl Ambystoma mexicanum: differences in aquatic and terrestrial environments.

    Science.gov (United States)

    Loong, Ai M; Chew, Shit F; Ip, Yuen K

    2002-01-01

    The fully grown but nonmetamorphosed (juvenile) axolotl Ambystoma mexicanum was ureogenic and primarily ureotelic in water. A complete ornithine-urea cycle (OUC) was present in the liver. Aerial exposure impeded urea (but not ammonia) excretion, leading to a decrease in the percentage of nitrogen excreted as urea in the first 24 h. However, urea and not ammonia accumulated in the muscle, liver, and plasma during aerial exposure. By 48 h, the rate of urea excretion recovered fully, probably due to the greater urea concentration gradient in the kidney. It is generally accepted that an increase in carbamoyl phosphate synthetase activity is especially critical in the developmental transition from ammonotelism to ureotelism in the amphibian. Results from this study indicate that such a transition in A. mexicanum would have occurred before migration to land. Aerial exposure for 72 h exhibited no significant effect on carbamoyl phosphate synthetase-I activity or that of other OUC enzymes (with the exception of ornithine transcarbamoylase) from the liver of the juvenile A. mexicanum. This supports our hypothesis that the capacities of OUC enzymes present in the liver of the aquatic juvenile axolotl were adequate to prepare it for its invasion of the terrestrial environment. The high OUC capacity was further supported by the capability of the juvenile A. mexicanum to survive in 10 mM NH(4)Cl without accumulating amino acids in its body. The majority of the accumulating endogenous and exogenous ammonia was detoxified to urea, which led to a greater than twofold increase in urea levels in the muscle, liver, and plasma and a significant increase in urea excretion by hour 96. Hence, it can be concluded that the juvenile axolotl acquired ureotelism while submerged in water, and its hepatic capacity of urea synthesis was more than adequate to handle the toxicity of endogenous ammonia during migration to land.

  12. Effects of sulfur-and polymer-coated controlled release urea on yield,photosynthetic characteristics and nitrogen fertilizer efficiency of rice%硫膜和树脂膜控释尿素对水稻产量、光合特性及氮肥利用率的影响

    Institute of Scientific and Technical Information of China (English)

    李敏; 郭熙盛; 叶舒娅; 刘枫; 袁嫚嫚; 黄义德

    2013-01-01

    Using sulfur-and polymer-coated controlled release urea (SPCU,PCU) with a releasing period of 90 days as experimental materials,a pot experiment was conducted to study the effects of sulfur-and polymer-coated controlled release urea on yield and photosynthetic characteristics and nitrogen fertilizer efficiency of rice.Compared with the conventional urea (U),the controlled release urea significantly increases the grain yields by 15.1%-51.4%,and increases the nitrogen apparent efficiencies and nitrogen agronomic efficiencies by 64.5%-141.1% and 5.4-18.2 kg/kg,respectively.The controlled release urea could greatly improve the net photosynthetic rate in flat leaves of rice and enhance SPAD during the middle-late growth stages.Compared with the conventional urea split,the polymer-coated controlled release urea and the 70% sulfur-coated controlled release urea combined with 30% conventional urea markedly increase the grain yields by 7.9%-31.7%,and the nitrogen agronomic efficiencies and soil total N and available N are increased by 3.3-13.0 kg/kg and 2.2%-17.6% and 13.2%-22.0%,respectively,and the net photosynthetic rate in flat leaves at the middle-late growth stages are also significantly increased.The effect of the 100% polymer-coated controlled release urea is most important.Compared with the conventional urea and the conventional urea split,the polymer-coated controlled release urea could significantly increase nitrogen fertilizer physiological efficiency of rice.The polymer-coated controlled release urea produces better rice yield and has higher nitrogen fertilizer efficiency and effective photosynthetic characteristics,compared with the sulfur-coated controlled release urea.%本试验以控释期为90d的硫膜(SPCU)和树脂膜(PCU)控释尿素为材料,通过盆栽试验,研究了硫膜和树脂膜控释尿素对水稻产量、光合特性及氮肥利用效率的影响.结果表明,与普通尿素(U)一次基施相比,控释尿素各

  13. Living with urea stress

    Indian Academy of Sciences (India)

    Laishram R Singh; Tanveer Ali Dar; Faizan Ahmad

    2009-06-01

    Intracellular organic osmolytes are present in certain organisms adapted to harsh environments. These osmolytes protect intracellular macromolecules against denaturing environmental stress. In contrast to the usually benign effects of most organic osmolytes, the waste product urea is a well-known perturbant of macromolecules. Although urea is a perturbing solute which inhibits enzyme activity and stability, it is employed by some species as a major osmolyte. The answer to this paradox was believed to be the discovery of protective osmolytes (methylamines). We review the current state of knowledge on the various ways of counteracting the harmful effects of urea in nature and the mechanisms for this. This review ends with the mechanistic idea that cellular salt (KCl/NaCl) plays a crucial role in counteracting the effects of urea, either by inducing required chaperones or methylamines, or by thermodynamic interactions with urea-destabilised proteins. We also propose future opportunities and challenges in the field.

  14. Moderate plasma treatment enhances the quality of optically detected magnetic resonance signals of nitrogen-vacancy centres in nanodiamonds

    Science.gov (United States)

    Sotoma, Shingo; Igarashi, Ryuji; Shirakawa, Masahiro

    2016-05-01

    We demonstrate that a moderate plasma treatment increases the quality of optically detected magnetic resonance (ODMR) signals from negatively charged nitrogen-vacancy centres in nanodiamonds (NDs). We measured the statistics of the ODMR spectra of 50-nm-size NDs before and after plasma treatment. We then evaluated each ODMR spectrum in terms of fluorescence and ODMR intensities, line width and signal-to-noise (SN) ratio. Our results showed that plasma treatment for more than 10 min contributes to higher-quality ODMR signals, i.e. signals that are brighter, stronger, sharper and have a higher SN ratio. We showed that such signal improvement is due to alteration of the surface chemical states of the NDs by the plasma treatment. Our study contributes to the advancement of biosensing applications using ODMR of NDs.

  15. 控释尿素与普通尿素配施对水稻氮代谢关键酶活性及产质量的影响%Effects of Combined Application of Controlled Release Urea and Common Urea on Activities of Key Enzymes Related with Nitrogen Metabolism, Yield and Quality of Rice

    Institute of Scientific and Technical Information of China (English)

    杜君; 孙克刚; 雷利君; 和爱玲; 张运红; 孙克振

    2016-01-01

    为了探明控释尿素对提高水稻氮肥利用率和产量、改善水稻品质的作用机制,通过田间试验,研究了控释尿素与普通尿素配施[处理1为对照(不施氮肥,CK),处理2为100%普通尿素,处理3为40%控释尿素+60%普通尿素,处理4为60%控释尿素+40%普通尿素,处理5为100%控释尿素]对水稻氮代谢关键酶活性、氮肥利用率以及产质量的影响。结果表明,与100%普通尿素相比,施用控释尿素能显著提高水稻齐穗期和乳熟期叶片中的硝酸还原酶活性,特别是乳熟期最为明显;总体能显著增强水稻齐穗期和乳熟期叶片谷氨酰胺合成酶活性、齐穗期至蜡熟期谷氨酰胺转化酶活性,其增强效果在齐穗期最为明显;能显著提高乳熟期和蜡熟期叶片的蛋白水解酶活性;总体能显著增强水稻齐穗期至蜡熟期籽粒中的谷氨酰胺合成酶和谷氨酰胺转化酶活性;能显著提高水稻产量及氮肥利用率,提高幅度分别为16.0%~21.4%和30.7%~48.5%;并能显著增加籽粒蛋白质含量。上述指标均以处理4增强效果最为明显。%In oder to verify the mechanism of controlled release urea( CRU) on increasing nitrogen use ef-ficiency, yield and improving rice quality, field experiments were conducted to study the effects of com-bined application of CRU and common urea( CU) on activities of key enzymes related with nitrogen me-tabolism and nitrogen use efficiency as well as yield and quality of rice with four treatments( treatment 1 without nitrogen fertilizer( CK) , treatment 2 with 100%CU,treatment 3 with 40%CRU+60%CU,treat-ment 4 with 60%CRU+40%CU,treatment 5 with 100%CRU) . The results showed that compared with 100%CU, the application of CRU could significantly improve nitrate reductase ( NR) activities of rice leaves at full heading stage and milk stage, especially at milk stage;as a whole, CRU could significantly improve glutamine synthetase activities of rice leaves at full heading

  16. Cytotoxicity study of plasma-sprayed hydroxyapatite coating on high nitrogen austenitic stainless steels.

    Science.gov (United States)

    Ossa, C P O; Rogero, S O; Tschiptschin, A P

    2006-11-01

    Stainless steel has been frequently used for temporary implants but its use as permanent implants is restricted due to its low pitting corrosion resistance. Nitrogen additions to these steels improve both mechanical properties and corrosion resistance, particularly the pitting and crevice corrosion resistance. Many reports concerning allergic reactions caused by nickel led to the development of nickel free stainless steel; it has excellent mechanical properties and very high corrosion resistance. On the other hand, stainless steels are biologically tolerated and no chemical bonds are formed between the steel and the bone tissue. Hydroxyapatite coatings deposited on stainless steels improve osseointegration, due their capacity to form chemical bonds (bioactive fixation) with the bone tissue. In this work hydroxyapatite coatings were plasma-sprayed on three austenitic stainless steels: ASTM-F138, ASTM-F1586 and the nickel-free Böhler-P558. The coatings were analyzed by SEM and XDR. The cytotoxicity of the coatings/steels was studied using the neutral red uptake method by quantitative evaluation of cell viability. The three uncoated stainless steels and the hydroxyapatite coated Böhler-P558 did not have any toxic effect on the cell culture. The hydroxyapatite coated ASTM-F138 and ASTM-F1586 stainless steels presented cytotoxicity indexes (IC50%) lower than 50% and high nickel contents in the extracts.

  17. Experimental and theoretical study on interaction between lanthanum and nitrogen during plasma rare earth nitriding

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C.S.; Yan, M.F., E-mail: yanmufu@hit.edu.cn; Sun, Z.

    2013-12-15

    In present work, the interaction between lanthanum (La) and nitrogen (N) during plasma rare earth nitriding of M50NiL martensitic steel is analyzed. Phase compositions, elemental contents as well as microhardness profiles of surface layers are investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and microhardness tester to observe the changes of the N contents in treated layers. The results of microhardness, XRD and EDS indicate that the addition of pure La can speed up the denitriding rate compared with the case without La addition. The XPS results reveal that the presence of the La-O and La-N bond reduces the peak intensity of the Me-N bond, which indicates that the addition of La element can reduce the N contents in nitrided layers through the surface oxidation and the attraction of La atoms. The theoretical thermodynamic calculations are employed to further clarify the denitriding function of the surface oxidation and the attraction between La and N atoms.

  18. Application of nitrogen plasma immersion ion implantation to titanium nasal implants with nanonetwork surface structure

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Ying-Sui; Yang, Wei-En [Department of Dentistry, National Yang-Ming University, Taipei 112, Taiwan (China); Zhang, Lan [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Zhu, Hongqin [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Lan, Ming-Ying [Division of Rhinology, Department of Otolaryngology Head and Neck Surgery, Taipei Veterans General Hospital, Taipei 112, Taiwan and School of Medicine, National Yang-Ming University, Taipei 112, Taiwan (China); Lee, Sheng-Wei [Institute of Materials Science and Engineering, National Central University, Taoyuan 320, Taiwan (China); Huang, Her-Hsiung, E-mail: hhhuang@ym.edu.tw [Department of Dentistry, National Yang-Ming University, Taipei 112, Taiwan (China); Institute of Oral Biology, National Yang-Ming University, Taipei 112, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung 404, Taiwan (China); Department of Medical Research, China Medical University Hospital, Taichung 407, Taiwan (China); Department of Bioinformatics and Medical Engineering, Asia University, Taichung 413, Taiwan (China); Department of Stomatology, Taipei Veterans General Hospital, Taipei 112, Taiwan (China)

    2016-07-15

    In nasal reconstruction, the response of cells to titanium (Ti) implants is mainly determined by surface features of the implant. In a pilot study, the authors applied electrochemical anodization to Ti surfaces in an alkaline solution to create a network of nanoscale surface structures. This nanonetwork was intended to enhance the responses of primary human nasal epithelial cell (HNEpC) to the Ti surface. In this study, the authors then treated the anodized, nanonetwork-structured Ti surface using nitrogen plasma immersion ion implantation (NPIII) in order to further improve the HNEpC response to the Ti surface. Subsequently, surface characterization was performed to elucidate morphology, roughness, wettability, and chemistry of specimens. Cytotoxicity, blood, and HNEpC responses were also evaluated. Our results demonstrate that NPIII treatment led to the formation of a noncytotoxic TiN-containing thin film (thickness <100 nm) on the electrochemically anodized Ti surface with a nanonetwork-structure. NPIII treatment was shown to improve blood clotting and the adhesion of platelets to the anodized Ti surface as well as the adhesion and proliferation of hNEpC. This research spreads our understanding of the fact that a TiN-containing thin film, produced using NPIII treatment, could be used to improve blood and HNEpC responses to anodized, nanonetwork-structured Ti surfaces in nasal implant applications.

  19. 周期性变动饲粮蛋白质水平对内蒙古白绒山羊内源尿素氮循环和微生物蛋白质合成的影响%Effects of Oscillating Dietary Protein Levels on Endogenous Urea Nitrogen Recycling and Microbial Protein Synthesis of Inner Mongolia White Cashmere Goats

    Institute of Scientific and Technical Information of China (English)

    樊艳华; 孙海洲; 桑丹; 李胜利; 张春华; 珊丹

    2014-01-01

    本试验旨在探讨周期性变动饲粮蛋白质水平对内蒙古白绒山羊内源尿素氮循环和微生物蛋白质合成的影响。饲粮分为低(7.5%)、中(10.5%)和高(13.5%)3个蛋白质水平。选用9只体况良好,体重为(45.63±3.15) kg,装有瘤胃瘘管的内蒙古白绒山羊,采用单因子随机区组试验设计分为3组,即中蛋白质饲粮组(对照组)、变动低蛋白质饲粮组(2 d低蛋白质饲粮—2 d高蛋白质饲粮,循环饲喂)、变动高蛋白质饲粮组(2 d高蛋白质饲粮—2 d低蛋白质饲粮,循环饲喂)。预试期16 d,正试期12 d。通过全收粪尿法、嘌呤衍生物法和同位素灌注法测定山羊氮代谢、内源尿素氮循环以及微生物蛋白质合成的变化。结果表明:1)中蛋白质饲粮组与变动蛋白质饲粮组比较,瘤胃液氨氮(NH3-N)浓度显著增加(P<0.05),粪氮、尿氮排出量显著增加(P<0.05),沉积氮/摄入氮显著降低( P<0.05),尿中嘌呤衍生物排出量和微生物蛋白质合成的量显著降低( P<0.05);2)变动低蛋白质饲粮组与变动高蛋白质饲粮组比较,瘤胃液NH3-N浓度显著降低( P<0.05);3)周期性变动饲粮蛋白质水平后,进入胃肠道的尿素氮/肝脏合成的内源尿素氮显著增加(P<0.05),进入尿中的尿素氮/肝脏合成的内源尿素氮显著减少(P<0.05),返回鸟氨酸循环的尿素氮/进入胃肠道的尿素氮显著减少( P<0.05),用于再合成的尿素氮/进入胃肠道的尿素氮显著增加( P<0.05)。综上所述,周期性变动饲粮蛋白质水平有利于提高内蒙古白绒山羊氮利用率和微生物蛋白质合成量。%This experiment was conducted to study the effects of oscillating dietary protein levels on endoge-nous urea nitrogen recycling and microbial protein synthesis of Inner Mongolia white cashmere goats. There were three levels of dietary protein, which were 7.5% ( low) , 10.5% ( medium) and 13.5% ( high) , respec-tively. Nine healthy Inner Mongolia white

  20. Nitrification Inhibitor on Urea-nitrogen Transformation and the Impact of Soil%不同硝化抑制剂的复配施用对尿素转化及土壤中氮的影响

    Institute of Scientific and Technical Information of China (English)

    傅丽; 石元亮; 苏壮; 王玲莉

    2011-01-01

    Urease inhibitors and nitrification inhibitors are used for slowing the hydrolysis of urea and ammonium nitrogen of soil to sell the conversion of N.In this experiment,brown earth was used as a substrate,in the same amount of urease inhibitor,under simulated field cultivation experiments conducted outdoors.The results showed that the application of nitrification inhibitors significantly inhibited the NH4+-N to NO3——N conversion of CMP with the nitrification inhibitor DCD fertilizer effect most significantly.Followed by nitrification inhibitor CMP with significant inhibition rate of 35.6%;ATC here showed no significant effect,but there were also some inhibitory effect.%通过室外模拟田间培养试验,研究不同硝化抑制剂及其复配后的硝化抑制效果。结果表明:不同硝化抑制剂,明显抑制了NH4^+-N向NO3^--N的转化。硝化抑制剂1-甲胺酰基-3,5-二甲基吡唑(CMP)有明显的抑制效果,优于4氨基-1,2,4-三唑盐酸盐(ATC)、双氰胺(DCD);硝化抑制剂CMP与DCD复配的抑制效果显著,硝化抑制率为35.6%。为了结合生产实际获得最优性价比,在硝化抑制剂复配比率方面尚需进一步研究。

  1. 不同胎龄早产儿早期血清尿素氮、肌酐水平变化及分析%Analysis of the trends of serum urea nitrogen and creatine in preterm infants with different gestational age during the early stage after birth

    Institute of Scientific and Technical Information of China (English)

    韦露明; 高宗燕; 刘芸芝; 刘义; 钟丹妮; 杨朝霞

    2016-01-01

    目的:探讨不同胎龄早产儿早期血清尿素氮、肌酐的变化规律及相关因素。方法对2012年1月至2014年12月广西医科大学第一附属医院新生儿病区收治的早产儿,根据出生时胎龄分为A(28~31周)、B(32~34周)、C(35~37周)三组,每组均30例,共90例入选。记录每组患儿出生后1、3、7 d的血清尿素氮、肌酐水平变化,对结果及相关因素进行分析。结果三组不同胎龄早产儿生后1、3、7 d的尿素氮、肌酐差异均有统计学意义(P均<0.05)。血清尿素氮在出生后早期有先下降而后上升的趋势,肌酐随着日龄的增加有下降的趋势。血清尿素氮与静脉蛋白摄入量正相关,肌酐与日龄负相关(r值分别为0.479和-0.46,均P<0.01)。结论早产儿血清尿素氮、肌酐受多种因素影响,血清尿素氮、肌酐作为评价早产儿生后早期肾功能的指标是不充分的。%ObjectiveTo study the levels and relative factors of serum urea nitrogen, creatine in preterm infants with different gestational age during the early stage after birth.MethodsWe analyzed the levels of serum urea nitrogen, creatine at day 1, 3, 7 after birth of the preterm infants admitted in the Division of Neonatology of our hospital between January 2012 and December 2014. 90 infants were divided into three group according to their gestational age (GA) at birth, A group (GA 28-31 weeks,n=30), B group (GA 32-34 weeks,n=30), C group (GA 35-37 weeks,n=30). The values of serum urea nitrogen, creatine at day 1, 3, 7 of all cases were recorded and analyzed.ResultsThe levels of serum urea nitrogen and creatine at day 1, 3, 7 after birth showed significantly differences (allP values<0.05). Serum urea nitrogen first decreased then rose during the first days after birth. Creatine showed a tendency to decline with the increase of day age. The serum urea nitrogen levels were positively correlated with intravenous protein

  2. Surface modification of poly(dimethylsiloxane) through oxygen and nitrogen plasma treatment to improve its characteristics towards biomedical applications

    Science.gov (United States)

    Gomathi, N.; Mishra, I.; Varma, S.; Neogi, S.

    2015-09-01

    Polymeric materials successfully applied in biomedical applications have an issue of poor surface properties which may restrict their applications as biomaterials. The present paper aims to study the effect of oxygen and nitrogen plasma treatment on physico-chemical properties of poly(dimethylsiloxane) (PDMS) and enhancement in its biocompatibility. Various characterization techniques including Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy (SEM), atomic force microscopy were used to evaluate the changes in surface chemistry and morphology of plasma treated PDMS. Changes in the wettability after plasma treatments and the effects of ageing on wettability were studied by contact angle measurement. Ageing studies showed that the contact angle was stable after two hours. The effect of plasma treatment on biocompatibility was studied through cell adhesion and MTT using 3T3 fibroblast cells. Morphology of cells obtained through SEM was analyzed using ImageJ software. Among the different treated and untreated samples, substantial enhancement in biocompatibility was observed for nitrogen plasma treated PDMS for 5 min in terms of highest cell area observed from cell adhesion test and highest cell viability observed from MTT test. This may be probably due to its highest polarity (0.4) and surface energy (33.3 N mm-2) with a moderate surface roughness (Rrms = 100.24 nm) among the other treated and untreated samples.

  3. Partial oxidation of methane to methanol with nitrogen dioxide in dielectric barrier discharge plasma: experimental and molecular modeling

    Science.gov (United States)

    Indarto, Antonius

    2016-04-01

    Non-catalytic conversion of methane (CH4) and nitrogen dioxide (NO2) into methanol (CH3OH) has been conducted and presented in this paper. Experiments were carried out using dielectric barrier discharge as the reaction medium in atmospheric pressure and temperature conditions. High yield production of methanol was achieved (18-20% mol) by single-stage plasma reaction with maximum selectivity of 32% mol. Compared to other oxidants, such as O2, the presence of NO2 in the plasma reaction resulted in higher methanol selectivity. For better understanding of the reactions, density functional theory calculations were also performed and discussed.

  4. Raising the Corrosion Resistance of Low-Carbon Steels by Electrolytic-Plasma Saturation with Nitrogen and Carbon

    Science.gov (United States)

    Kusmanov, S. A.; Grishina, E. P.; Belkin, P. N.; Kusmanova, Yu. V.; Kudryakova, N. O.

    2017-05-01

    Structural features of the external oxide layer and internal nitrided, carbonitrided and carburized layers in steels 10, 20 and St3 produced by the method of electrolytic plasma treatment are studied. Specimens of the steels are tested for corrosion in a naturally aerated 1-N solution of sodium chloride. The condition of the metal/sodium chloride solution interface is studied by the method of electrochemical impedance spectroscopy. It is shown that the corrosion resistance of low-carbon steels can be raised by anode electrolytic-plasma saturation with nitrogen and carbon. Recommendations are given on the choice of carbonitriding modes for structural steels.

  5. Forms of urea and nitrogen levels in top dressing in the agronomic performance of wheat genotypesFormas de ureia e doses de nitrogênio em cobertura no desempenho agronômico de genótipos de trigo

    Directory of Open Access Journals (Sweden)

    Vanoli Fronza

    2012-05-01

    Full Text Available The objective of this study was to evaluate the effect of nitrogen fertilization in top dressing from various forms of urea in wheat genotypes on no-till system. Wheat genotypes developed by EMBRAPA (cultivars BRS 208 and BRS Pardela and line IWT 04008 were evaluated in three independents experiments in Ponta Grossa, State of Paraná, Brazil in 2008. Three forms of urea were evaluated (conventional urea, urea with urease inhibitor and protected urea with four levels of N (0, 40, 80 and 120 kg ha-1 applied in top dressing in early tillering. Randomized block design, in a 3 x 4 factorial experiment, with four replications were used. The increase in the levels of nitrogen in any form of urea used, increase the dry mass of the flag leaf, the number of spikes m-2 and yield, but reduces hectoliter mass. The form of urea applied in top dressing does not influence the agronomic characteristics of the evaluated genotypes. Cultivars BRS 208 and BRS Pardela were more productive and had higher N content grain than line IWT 04008. O objetivo do trabalho foi avaliar o efeito de doses de adubação nitrogenada em cobertura, provenientes de diferentes formas de ureia, em genótipos de trigo, no sistema de semeadura direta. Os genótipos de trigo desenvolvidos pela EMBRAPA (cultivares BRS 208 e BRS Pardela e linhagem IWT 04008 foram avaliados em três experimentos independentes em Ponta Grossa-PR na safra de 2008. O delineamento experimental foi o de blocos casualizados em esquema fatorial 3 x 4, com quatro repetições. Avaliou-se três formas de ureia (ureia convencional, ureia com inibidor de urease e ureia protegida com quatro doses de N (0, 40, 80 e 120 kg ha-1 aplicadas em cobertura no início do perfilhamento. O incremento das doses de N em cobertura, independentemente da forma de ureia utilizada, favorece a massa seca da folha bandeira, o número de espigas m-2 e a produtividade, porém reduz o peso do hectolitro. A forma de ureia aplicada em cobertura n

  6. Effect of Application of Base Controlled Release Fertilizers and Top Dressing of Various Proportions of Ordinary Urea on Yield of Summer Corn and Utilization Ratio of Nitrogenous Fertilizers%控释肥料基施及普通尿素不同基追比对夏玉米产量及氮肥利用率的影响

    Institute of Scientific and Technical Information of China (English)

    孙克刚; 张欣; 李丙奇; 刘京宝; 和爱玲

    2011-01-01

    研究了控释尿素和控释BB肥一次性基施后的肥料效果,以及普通尿素不同基追比对玉米产量和氮肥利用率的影响.研究结果表明:以33.3%普通尿素基施+33.3%大喇叭口期追施+33.3%抽雄期追施的处理最佳,产量最高达8 700 kg/hm2,氮肥利用率为34.3%.控释尿素基施处理和控释BB肥基施处理的氮肥利用率分别为41.7%和44.1%,均高于施用普通尿素的各处理,且控释BB肥基施处理的氮肥利用率高于控释尿素基施处理.%A study is made of the fertilizer effect of base application once of controlled release urea and bulk blending ( BB) fertilizers as well as various proportions of top dressing of ordinary urea on corn yield and utilization ratio of nitrogenous fertilizers. The results show that the best treatment method is the use of base application with 33. 3% ordinary urea plus top dressing with 33. 3% at big trumpet period plus top dressing with 33. 3% in tasseling period, the highest yield is 8 700 kg/hm2, and the utilization ratio of the nitrogenous fertilizers is 34. 3%. When controlled release urea and controlled release BB fertilizers are base applied, the nitrogen fertilizer utilization ratio is 41.7% and 44.1% ,respectively, higher than various treatments with ordinary urea, and the utilization of base applied controlled release BB fertilizers is higher than that of base applied controlled release urea.

  7. 变性淀粉包裹型缓释尿素对冬小麦生长发育及氮素农学效率的影响%Effects of Modified Starch Coated and Slow Released Urea on Growth and Nitrogen Agronomic Efficiency Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    翟彩霞; 吴欢欢; 王丽英; 陈丽莉; 李若楠; 窦菲; 张彦才; 李在涵

    2011-01-01

    采用田间小区试验方法,研究了变性淀粉包裹型缓释尿素对冬小麦生长、旗叶净光合速率、旗叶水分利用率、产量及氮素农学效率的影响.结果表明,变性淀粉包裹型缓释尿素一次性基施,冬小麦单株干质量高于普通尿素处理,根系活力提高4.9%~16.66%,叶片净光合提高4.4%~9.4%,旗叶水分利用率提高8.63%~25.17%;收获期,缓释尿素处理氮肥效率及耕层土壤硝态氮含量均高于普通尿素处理,而深层土壤硝态氮含量低于普通尿素处理,冬小麦产量提高14.7%~16.5%.氮肥的种类、释放特性及施肥量是影响土壤硝态氮含量的主要因素,施肥量的提高可能增加土壤硝态氮通过氮素淋洗对地下水潜在污染风险.%The field plot experiment was conducted and it were discussed about the effects of modified starch coated and slow release urea on winter wheat growth ,photosynthetic rate and water efficiency in flag leaf,yield and nitrogen agronomic efficiency. The results indicated that the wheat dry matter increased when coated and slow release urea as base fertilzer compared with urea. The root vigor activity increased 4.90% to 16.66% ,photosynthetic rate and water efficiency in flag leaf increased 4.41% to 9.41% and 8.63% to 25.17% respectively. After harvest,the soil nitrate content with coated and slow release urea applied was higher than urea used in the surface depth, but lower in the deep soil. the the wheat yield increased 9.4% in the coated and slow released urea treatment. So the characteristics of nitrogen releasing were main factor,which affected the soil nitrogen content. With fertilizer amount increased,groundwater contaminated would increase.

  8. Phenylbutyrate reduces plasma leucine concentrations without affecting the flux of leucine

    Science.gov (United States)

    Phenylbutyrate (PB) has been used as an alternative pathway to excrete nitrogen in urea cycle disorder patients for the last 20 years. PB, after oxidation to phenylacetate, is conjugated with glutamine and excreted in the urine. A reduction in the plasma concentration of branched amino acids (BCAA) ...

  9. Effect of feeding garlic leaves on rumen fermentation, methane emission, plasma glucose kinetics, and nitrogen utilization in sheep.

    Science.gov (United States)

    Panthee, Arvinda; Matsuno, Ayana; Al-Mamun, Mohammad; Sano, Hiroaki

    2017-01-01

    Garlic and its constituents are reported to have been effective in reducing methane emission and also influence glucose metabolism in body; however, studies in ruminants using garlic leaves are scarce. Garlic leaves contain similar compounds as garlic bulbs, but are discarded in field after garlic bulb harvest. We speculate that feeding garlic leaves might show similar effect as garlic constituents in sheep and could be potential animal feed supplement. Thus, we examined the effect of freeze dried garlic leaves (FDGL) on rumen fermentation, methane emission, plasma glucose kinetics and nitrogen utilization in sheep. Six sheep were fed Control diet (mixed hay and concentrate (60:40)) or FDGL diet (Control diet supplemented with FDGL at 2.5 g/kg BW(0.75) of sheep) using a crossover design. Methane gas emission was measured using open-circuit respiratory chamber. Plasma glucose turnover rate was measured using isotope dilution technique of [U-(13)C]glucose. Rumen fluid, feces and urine were collected to measure rumen fermentation characteristics and nitrogen utilization. No significant difference in rumen fermentation parameters was noticed except for rumen ammonia tended to be higher (0.05 glucose concentration was similar between diets and plasma glucose turnover rate tended to be higher in FDGL diet (0.05 glucose turnover rate and microbial nitrogen supply, further studies at higher dose would be necessary to conclude the merit of FDGL as supplement in ruminant feedstuff.

  10. Phenylbutyrate improves nitrogen disposal via alternative pathway without eliciting an increase in protein breakdown and catabolism in control and ornithine transcarbamylace-deficient patients

    Science.gov (United States)

    Phenylbutyrate (PB) is a drug used in urea cycle disorder patients to elicit alternative pathways for nitrogen disposal. However, PB decreases plasma branched chain amino acid (BCAA) concentrations and prior research suggests that PB may increase leucine oxidation, indicating increased protein degra...

  11. MRT letter: high resolution SEM imaging of nano-architecture of cured urea-formaldehyde resin using plasma coating of osmium.

    Science.gov (United States)

    Park, Byung-Dae; Singh, Adya P; Nuryawan, Arif; Hwang, Kiju

    2013-11-01

    Nanoarchitecture of cured urea-formaldehyde (UF) resins was examined with a field-emission scanning electron microscope (FE-SEM) after coating samples with osmium, which is considered to produce particles of considerably smaller size compared to other metal coatings used in SEM studies. This method enabled comparison of the nanoarchitecture of UF resins of low (1.0) and high (1.6) formaldehyde/urea (F/U) mole ratios to be made, based on imaging of extremely small size particles as part of UF resin architecture, not described before. Imaging revealed presence of relatively large globular particles (148.084-703.983 nm size range) as well as smaller substructures (28.004-39.604 nm size range) as part of the architecture of 1.0-mole UF resin. Globular particles were also present in 1.6 mole UF resin, but of considerably smaller size (14.760-50.269 nm). The work presented demonstrates usefulness of osmium coating in unraveling the intricacies of the nanostructural organization of cured UF resins, prompting wider application of this immensely useful but grossly underutilized metal coating type in high resolution SEM examination of biological and materials samples.

  12. Active urea transport in lower vertebrates and mammals.

    Science.gov (United States)

    Bankir, Lise

    2014-01-01

    Some unicellular organisms can take up urea from the surrounding fluids by an uphill pumping mechanism. Several active (energy-dependent) urea transporters (AUTs) have been cloned in these organisms. Functional studies show that active urea transport also occurs in elasmobranchs, amphibians, and mammals. In the two former groups, active urea transport may serve to conserve urea in body fluids in order to balance external high ambient osmolarity or prevent desiccation. In mammals, active urea transport may be associated with the need to either store and/or reuse nitrogen in the case of low nitrogen supply, or to excrete nitrogen efficiently in the case of excess nitrogen intake. There are probably two different families of AUTs, one with a high capacity able to establish only a relatively modest transepithelial concentration difference (renal tubule of some frogs, pars recta of the mammalian kidney, early inner medullary collecting duct in some mammals eating protein-poor diets) and others with a low capacity but able to maintain a high transepithelial concentration difference that has been created by another mechanism or in another organ (elasmobranch gills, ventral skin of some toads, and maybe mammalian urinary bladder). Functional characterization of these transporters shows that some are coupled to sodium (symports or antiports) while others are sodium-independent. In humans, only one genetic anomaly, with a mild phenotype (familial azotemia), is suspected to concern one of these transporters. In spite of abundant functional evidence for such transporters in higher organisms, none have been molecularly identified yet.

  13. Utilização do nitrogênio (15N residual de coberturas de solo e da uréia pela cultura do milho Utilization of residual nitrogen (15N from cover crop and urea by corn

    Directory of Open Access Journals (Sweden)

    Edson Cabral da Silva

    2006-12-01

    study was to evaluate the use of residual nitrogen from urea, sunnhemp (Crotalaria juncea and millet (Pennisetum americanum labeled with 15N, applied to no-tillage corn in the previous growing season, in a Red Latosol of the Cerrado. The study was conducted in an experimental farm of the Sao Paulo State University (UNESP, Ilha Solteira, in Selvíria county (MS, Brazil, in different areas. The experiment had a randomized complete block design, with 15 treatments and four replications. Treatments were applied to corn crop in the 2001/02 and 2003/04 growing seasons. Theey were distributed in a 3 x 5 factorial layout, representing the combination of three cover crops: sunnhemp, millet and spontaneous vegetation (fallow and five N rates (as urea: 0, 30, 80, 130, and 180 kg ha-1 of N. After corn harvest, the two areas were fallowed in the dry season and were followed by corn crop in the 2002/03 (experiment 1 and 2003/04 (experiment 2 growing seasons, using the same fertilizer rate on all plots to distinguish the residual effect of N sources. The average use of residual N from the millet and sunnhemp residues (above-ground part by corn crop was less than 3.5 and 3 %, respectively, of the initial amount. The corn uptake of residual N from urea increased in a quadratic manner in experiment 1 and linearly in experiment Two as a response to the applied N rates, and the recover was below 3 %. The cover crop type did not affect the use of residual N of urea by corn, and vice-versa.

  14. Ammonia formation and W coatings interaction with deuterium/nitrogen plasmas in the linear device GyM

    Science.gov (United States)

    Laguardia, L.; Caniello, R.; Cremona, A.; Dellasega, D.; Dell'Era, F.; Ghezzi, F.; Gittini, G.; Granucci, G.; Mellera, V.; Minelli, D.; Pallotta, F.; Passoni, M.; Ricci, D.; Vassallo, E.

    2015-08-01

    In this work results of the first D2/N2 experiments in GyM, a linear device able to produce plasmas of interest for the ITER divertor (ne 5 ṡ 1010 cm-3, Te 5 eV, ion flux 3-5 ṡ 1020 m-2s-1) are presented. Plasmas simulating a N-seeding scenario have been performed to evaluate ammonia formation and its effect on exposed W coatings. The presence of ND emission lines in the plasma can be correlated with the formation of ammonia, further directly detected and quantified by chromatography analysis of the exhaust. Four different W specimens were exposed in GyM to a plasma fluence of 8.78 ṡ 1023 m-2. XPS analysis evidenced the formation of WxNy layers with nitrogen concentration in the range of 1-10% depending on the initial morphology and structure of the W samples. In all analyzed cases, nitrogen was bound and retained within the first 6 nm below the surface and no further diffusion of N into the bulk was observed.

  15. Kinetics of organic molecules in pulsed plasmas of nitrogen or N2/O2 mixtures at near atmospheric pressure

    Science.gov (United States)

    Pasquiers, S.; Blin-Simiand, N.; Magne, L.

    2013-12-01

    In plasmas of atmospheric gases, the kinetics of some aliphatic organic molecules belonging to the hydrocarbons (propene, propane), aldehydes (acetaldehyde) and ketones (acetone) families were studied using a photo-triggered discharge (homogeneous plasma). It was shown that quenchings of N2 metastable states, A\\,^{3}\\Sigma_{u}^{+} and the group of singlets a'\\,^{1}\\Sigma_{u}^{-} , a 1Πg and w 1Δu, are important processes for the decomposition of such molecules. It plays a fundamental role in the nitrogen plasma, but it is also present in air. At low temperature, the oxidation reactions by the oxygen atom or by the hydroxyl radical are not always sufficiently effective to induce an increase of the molecule decomposition when oxygen is added to the nitrogen/organic mixture. For most cases, quenching processes appear purely dissociative. However, recent results obtained for propene lead to the conclusion that a non-dissociative exit route could exist. The quenching of the singlet states induces a break of the double bound C = O for the acetaldehyde and acetone molecules. Some kinetic analogies appear between filamentary and homogeneous plasmas, which could be very useful to get a comprehensive understanding of the physico-chemical processes in dielectric barriers or corona discharges used for various applications.

  16. Ammonia formation and W coatings interaction with deuterium/nitrogen plasmas in the linear device GyM

    Energy Technology Data Exchange (ETDEWEB)

    Laguardia, L., E-mail: laguardia@ifp.cnr.it [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Caniello, R.; Cremona, A. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Dellasega, D. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Politecnico di Milano, Dipartimento di Energia, Milan (Italy); Dell’Era, F.; Ghezzi, F.; Gittini, G.; Granucci, G.; Mellera, V.; Minelli, D.; Pallotta, F. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Passoni, M. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy); Politecnico di Milano, Dipartimento di Energia, Milan (Italy); Ricci, D.; Vassallo, E. [CNR, Istituto di Fisica del Plasma“P. Caldirola”, Milan (Italy)

    2015-08-15

    In this work results of the first D{sub 2}/N{sub 2} experiments in GyM, a linear device able to produce plasmas of interest for the ITER divertor (n{sub e} 5 ⋅ 10{sup 10} cm{sup −3}, Te 5 eV, ion flux 3–5 ⋅ 10{sup 20} m{sup −2}s{sup −1}) are presented. Plasmas simulating a N-seeding scenario have been performed to evaluate ammonia formation and its effect on exposed W coatings. The presence of ND emission lines in the plasma can be correlated with the formation of ammonia, further directly detected and quantified by chromatography analysis of the exhaust. Four different W specimens were exposed in GyM to a plasma fluence of 8.78 ⋅ 10{sup 23} m{sup −2}. XPS analysis evidenced the formation of W{sub x}N{sub y} layers with nitrogen concentration in the range of 1–10% depending on the initial morphology and structure of the W samples. In all analyzed cases, nitrogen was bound and retained within the first 6 nm below the surface and no further diffusion of N into the bulk was observed.

  17. Design and operation results of nitrogen gas baking system for KSTAR plasma facing components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Tae [National Fusion Research Institute, 113 Gwahang-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Kim, Young-Jin, E-mail: k43689@nfri.re.kr [National Fusion Research Institute, 113 Gwahang-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Joung, Nam-Yong; Im, Dong-Seok; Kim, Kang-Pyo; Kim, Kyung-Min; Bang, Eun-Nam; Kim, Yaung-Soo [National Fusion Research Institute, 113 Gwahang-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Yoo, Seong-Yeon [Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of)

    2013-11-15

    Highlights: • Vacuum pressure in a vacuum vessel arrived at 7.24 × 10{sup −8} mbar. • PFC temperature was reached maximum 250 °C by gas temperature at 300 °C. • PFC inlet gas temperature was changed 5 °C per hour during rising and falling. • PFC gas balancing was made temperature difference among them below 8.3 °C. • System has a pre-cooler and a three-way valve to save operation energy. -- Abstract: A baking system for the Korea Superconducting Tokamak Advanced Research (KSTAR) plasma facing components (PFCs) is designed and operated to achieve vacuum pressure below 5 × 10{sup −7} mbar in vacuum vessel with removing impurities. The purpose of this research is to prevent the fracture of PFC because of thermal stress during baking the PFC, and to accomplish stable operation of the baking system with the minimum life cycle cost. The uniformity of PFC temperature in each sector was investigated, when the supply gas temperature was varied by 5 °C per hour using a heater and the three-way valve at the outlet of a compressor. The alternative of the pipe expansion owing to hot gas and the cage configuration of the three-way valve were also studied. During the fourth campaign of the KSTAR in 2011, nitrogen gas temperature rose up to 300 °C, PFC temperature reached at 250 °C, the temperature difference among PFCs was maintained at below 8.3 °C, and vacuum pressure of up to 7.24 × 10{sup −8} mbar was achieved inside the vacuum vessel.

  18. Perdas de nitrogênio por volatilização de amônia e resposta do arroz irrigado à aplicação de ureia tratada com o inibidor de urease NBPT Nitrogen losses by ammonia volatilization and lowland rice response to NBPT urease inhibitor-treated urea

    Directory of Open Access Journals (Sweden)

    Walkyria Bueno Scivittaro

    2010-06-01

    ção, sem prejuízos para a produtividade de grãos e a acumulação de nitrogênio pelo arroz.Urea is the main nitrogen source used in flooded rice fields, but it is prone to ammonia volatilization losses. The use of N-(n-butyl thiophosphoric triamide (NBPT urease inhibitor, as urea additive, can reduce this inconvenient, inhibiting temporarily urea enzymatic degradation. An experiment was carried out on a Planossolo Háplico (Albaqualf, from October 2004 to April 2005, in Capão do Leão, RS, Brazil, to evaluate the effect of NBPT inhibitor-treated urea on nitrogen losses by ammonia volatilization, rice grain yield, and rice nitrogen accumulation, in two soil moisture conditions. The treatments were arranged as a randomized complete block with two soil moisture conditions (moist and muddy, two nitrogen sources (non treated urea and urea treated with NBPT and three time intervals between nitrogen application and flooding (1, 5, and 10 days in a factorial design with four replications. Nitrogen rate was 120kg N ha-1, applied at 4- to 5- leaf stage (90kg N ha-1 and at panicle differentiation (30kg N ha-1. Volatilization losses as ammonia from the urea treatment varied from 15% (muddy soil to 22% (moist soil of the applied N, when the time interval between nitrogen application and flooding was 10 days. Addition of NBPT reduced 83% and 88% ammonia volatilization losses in muddy soil and moist soil conditions, respectively. For the 10 days interval between nitrogen application and flooding, NBPT treated urea promoted greater rice yield and nitrogen accumulation, compared to non treated urea. The use of NBPT inhibitor makes possible applying urea up to ten days before flooding with no decrease on rice grain yield and nitrogen accumulation.

  19. Evaluation of bactericidal effects of low-temperature nitrogen gas plasma towards application to short-time sterilization.

    Science.gov (United States)

    Kawamura, Kumiko; Sakuma, Ayaka; Nakamura, Yuka; Oguri, Tomoko; Sato, Natsumi; Kido, Nobuo

    2012-07-01

    To develop a novel low-temperature plasma sterilizer using pure N(2) gas as a plasma source, we evaluated bactericidal ability of a prototype apparatus provided by NGK Insulators. After determination of the sterilizing conditions without the cold spots, the D value of the BI of Geobacillus stearothermophilus endospores on the filter paper was determined as 1.9 min. However, the inactivation efficiency of BI carrying the same endospores on SUS varied to some extent, suggesting that the bactericidal effect might vary by materials of sterilized instruments. Staphylococcus aureus and Escherichia coli were also exposed to the N(2) gas plasma and confirmed to be inactivated within 30 min. Through the evaluation of bactericidal efficiency in a sterilization bag, we concluded that the UV photons in the plasma and the high-voltage pulse to generate the gas plasma were not concerned with the bactericidal effect of the N(2) gas plasma. Bactericidal effect might be exhibited by activated nitrogen atoms or molecular radicals.

  20. Mineralization and volatilization of nitrogen from vinasse-{sup 15} N in the presence or absence of urea and sugar cane straw; Mineralizacao e volatilizacao do nitrogenio da vinhaca-{sup 15} N na presenca ou nao de ureia e de palha de cana-de-acucar

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Vilma Maria; Colaco, Waldeciro [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear; Trivelin, Paulo Cesar Ocheuse [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil); Encarnacao, Fernando Antonio Franco da [Alagoas Univ., Maceio, AL (Brazil). Dept. de Geologia e Topografia; Cabezas, Waldo Alejandro Ruben Lara [Uberlandia Univ., MG (Brazil). Dept. de Agronomia

    1999-03-01

    The mineralized and volatilized nitrogen derived from vinasse labelled with {sup 15} N were determined in a laboratory experiment, using samples of two soils [a sandy Red-Yellow-Podzolic-PV and a clayey Latosol - LR (Oxisol)], collected in Piracicaba, SP, Brazil. The experiment consisted of four treatments: application of vinasse (V{sup *}); vinasse with urea (V{sup *}+U); vinasse with sugar cane straw (V{sup *}+P); and vinasse with urea and sugar cane straw (V{sup *}+U+P). Vinasse, labelled with {sup 15} N (V{sup *}) was applied at a rate of 100 mg.kg{sup -1} of N-vinasse. All treatments, were incubated for 7, 14, 21, 28 and 35 days. N-urea and sugar cane straw were incorporated in the soil at rates of 220 mg.kg{sup -1} and 22 g.kg{sup -1}, respectively. N H{sub 4}{sup +} -N and NO{sub 3}{sup -} -N concentrations, as a result of the vinasse addition, were affected by soil type. A larger availability of N H{sub 4}{sup +} -N and NO{sub 3}{sup -} -N derived from vinasse were observed, when urea was added. Sugar cane straw plus vinasse did not alter the concentrations of N H{sub 4}{sup +} - N and NO{sub 3}{sup -} - N derived from vinasse. Urea plus sugar cane straw did not affect N H{sub 4}{sup +} -N concentrations, and affected the NO{sub 3}{sup -} -N concentration in LR soil over time. Losses of vinasse-N, due to volatilization, increased with time for all treatments, and were larger for PV (14%) than for LR(5%); but such losses were similar in LR soil. (author)

  1. [Automatic enzymatic determination of urea nitrogen].

    Science.gov (United States)

    Tagliaferri, L; Dacrema, F

    1986-12-01

    Six BUN kits available on the market, applied on selective chemistry analyzer, shown acceptable accuracy, good stability and linearity, "borderline" within-day and among-day standard deviations. The cause is investigated, particularly in the dispenser of the analyzer for delivering samples and reagents.

  2. Band Gap Tailoring of TiO2 Nanowires by Nitrogen Doping Under N2/Ar Plasma Environment.

    Science.gov (United States)

    Dhar, J C; Mondal, A; Bhattacharya, S; Singh, N K; Ngangbam, C; Chattopadhyay, K K

    2015-05-01

    Glancing angle deposited TiO2 nanowires (NWs) were doped with nitrogen (N) using plasma-enhanced chemical vapour deposition technique, under the treatment of N2/Ar plasma. A red shift (- 0.51 eV) in the main band transition and oxygen defect related transition (-2.1 eV) was observed for the N doped TiO2 nanowires. The interstitial nitrogen introduces mid-gap levels N (2P) above the O (2P) in the TiO2 forbidden gap. The photoluminescence measurement revealed a small red shift of -7 nm of anatase band gap from N doped TiO2 nanowires due to radiative recombination of carriers from conduction band to the N (2P) trap state. The low frequency Raman peaks at 304 cm(-1) (acoustical phonons with LA mode), 618 cm(-1) (optical phonons with LO modes) and the high frequency peak at 832 cm(-1) was observed from Ti-O-N due to the partial replacement of oxygen molecules by nitrogen into TiO2, during the doping process.

  3. Control of ammonia and urea emissions from urea manufacturing facilities of Petrochemical Industries Company (PIC), Kuwait.

    Science.gov (United States)

    Khan, A R; Al-Awadi, L; Al-Rashidi, M S

    2016-06-01

    Petrochemical Industries Company (PIC) in Kuwait has mitigated the pollution problem of ammonia and urea dust by replacing the melting and prilling units of finished-product urea prills with an environmentally friendly granulation process. PIC has financed a research project conducted by the Coastal and Air Pollution Program's research staff at the Kuwait Institute for Scientific Research to assess the impact of pollution control strategies implemented to maintain a healthy productive environment in and around the manufacturing premises. The project was completed in three phases: the first phase included the pollution monitoring of the melting and prilling units in full operation, the second phase covered the complete shutdown period where production was halted completely and granulation units were installed, and the last phase encompassed the current modified status with granulation units in full operation. There was substantial decrease in ammonia emissions, about 72%, and a 52.7% decrease in urea emissions with the present upgrading of old melting and prilling units to a state-of-the-art technology "granulation process" for a final finished product. The other pollutants, sulfur dioxide (SO2), nitrogen oxides (NOx), and volatile organic compounds (VOCs), have not shown any significant change, as the present modification has not affected the sources of these pollutants. Petrochemical Industries Company (PIC) in Kuwait has ammonia urea industries, and there were complaints about ammonia and urea dust pollution. PIC has resolved this problem by replacing "melting and prilling unit" of final product urea prills by more environmentally friendly "granulation unit." Environmental Pollution and Climate Program has been assigned the duty of assessing the outcome of this change and how that influenced ammonia and urea dust emissions from the urea manufacturing plant.

  4. The effects of intraruminal infusions of urea, casein, glucose syrup and a mixture of casein and glucose syrup on nitrogen digestion in the rumen of cattle receiving grass-silage diets.

    Science.gov (United States)

    Rooke, J A; Lee, N H; Armstrong, D G

    1987-01-01

    In an incomplete 5 X 5 Latin square experiment, four cattle were given grass silage in two meals per d to satisfy 1.15 maintenance energy requirements. In addition, water or casein (21 g nitrogen and 0.17 kg organic matter (OM)/d) or urea (U; 28 g N/d) or a glucose syrup (G; 0.87 kg OM/d) or casein and glucose syrup (CG; 17 g N and 0.93 kg OM/d) were infused intraruminally at a constant rate. A 24 h collection of duodenal digesta was made using chromic oxide for flow estimation and 35S as a marker of microbial N entering the small intestine. Samples of rumen fluid were also taken for estimation of rumen pH, and concentrations of ammonia-N and volatile fatty acids. The intraruminal infusions had no significant effects on rumen pH, concentrations of volatile fatty acids or their molar proportions. Infusion of either C or U significantly (P less than 0.05) increased rumen NH3-N concentrations whereas infusions of either G or CG lowered rumen NH3-N concentrations. Infusions of C or U had no significant effect on the quantities of OM, acid-detergent fibre (ADF) or N constituents which entered the small intestine. Infusions of G or CG increased the quantities of OM (G P less than 0.05, CG P less than 0.01), ADF (CG P less than 0.05), non-NH3-N (G P less than 0.05, CG P less than 0.01), amino acid N (G P less than 0.05, CG P less than 0.01) and microbial N (G P less than 0.05, CG P less than 0.01) which entered the small intestine. The efficiency of rumen microbial N synthesis was unchanged by the infusion of C, U or G (P greater than 0.05) but increased significantly (P less than 0.05) when CG were infused.

  5. How renal cells handle urea.

    Science.gov (United States)

    Bagnasco, S M

    2000-01-01

    The urine concentration process requires an osmolality gradient along the renal cortico-medullary axis, with highest values in the renal papilla. NaCl and urea are the major solutes in the renal inner medulla, concentrations of urea up to 500-600 mM are found in the rat renal papilla. Urea can diffuse across cell membranes and contributes to balance intracellular and extracellular osmotic equilibrium. However, urea has perturbing effects on enzyme activity, and in concentrations above 300 mM is toxic for renal cultured cells. There is increasing evidence that urea can induce cellular responses distinct from those due to NaCl and other non-permeable solutes, including upregulation of immediate-early genes (IEGs). Urea transport by epithelial and endothelial cells is important for intra-medullary urea recycling and preservation of high urea concentration in the inner medulla. Trans-cellular movement of urea in cells expressing urea transporters may influence intracellular levels of this solute and modulate urea-induced signaling pathways. Regulation of urea transporters expression and activity can therefore be viewed as one aspect of cellular adaptation to urea. We have identified tonicity-responsive transcription as one mechanism regulating expression of the urea transporter UT-A. The short-term and long-term effects of variable extracellular urea concentration on the function of renal cells remain still unclear.

  6. Thiazide-induced hyponatraemia is associated with increased water intake and impaired urea-mediated water excretion at low plasma antidiuretic hormone and urine aquaporin-2.

    NARCIS (Netherlands)

    Frenkel, N.J.; Vogt, L.; Rooij, S.E. De; Trimpert, C.; Levi, M.M.; Deen, P.M.T.; Born, B.J. van den

    2015-01-01

    BACKGROUND: Hyponatraemia is a common, potentially life-threatening, complication of thiazide diuretics. The mechanism of thiazide-induced hyponatraemia is incompletely understood. Previous experiments have suggested a direct effect of thiazide diuretics on the plasma membrane expression of aquapori

  7. Thiazide-induced hyponatraemia is associated with increased water intake and impaired urea-mediated water excretion at low plasma antidiuretic hormone and urine aquaporin-2

    NARCIS (Netherlands)

    Frenkel, Nanne J.; Vogt, Liffert; De Rooij, Sophia E.; Trimpert, Christiane; Levi, Marcel M.; Deen, Peter M. T.; van den Born, Bert-Jan H.

    2015-01-01

    Background: Hyponatraemia is a common, potentially life-threatening, complication of thiazide diuretics. The mechanism of thiazide-induced hyponatraemia is incompletely understood. Previous experiments have suggested a direct effect of thiazide diuretics on the plasma membrane expression of aquapori

  8. Thiazide-induced hyponatraemia is associated with increased water intake and impaired urea-mediated water excretion at low plasma antidiuretic hormone and urine aquaporin-2

    NARCIS (Netherlands)

    Frenkel, Nanne J; Vogt, Liffert; De Rooij, Sophia E; Trimpert, Christiane; Levi, Marcel M; Deen, Peter M T; van den Born, Bert-Jan H

    2015-01-01

    BACKGROUND: Hyponatraemia is a common, potentially life-threatening, complication of thiazide diuretics. The mechanism of thiazide-induced hyponatraemia is incompletely understood. Previous experiments have suggested a direct effect of thiazide diuretics on the plasma membrane expression of aquapori

  9. Composition and Structure of Ti-6Al-4V Alloy Plasma-based Ion Implanted with Nitrogen

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The composition and structure of Ti-6Al-4V alloy plasma-based ion implanted with nitrogen was investigated.The nitrogen depth distribution shows more antiballistic with distribution peak heightened with increased implantation time(dose),and more like a parabola at the low implantation pulse voltage.When implantation pulse voltage is increased,the implantation depth increased with the nitrogen distribution peak being deepened,widened and lowered somewhat.TiN,TiN+Ti2N,or Ti2N second phases were formed in the implanted layer.The relative percentage of nitrogen content in the form of TiN increases when going deeper into the implanted(TiN formed) layer.The increase of implantation pulse width and/or time is favourable for the formation of TiN rather than Ti2N.It is unfavourable for formation of any nitrides when implantation pulse voltage is decreased to 30kV or less.Tiny crystalline particles (made mainly of Ti2N and a smaller percentage of TiO2 phases) of regular shapes such as triangle and tetragon,etc.(about 20 nm) are found distrbuted dispersively in the near surface region of samples implanted at the high implantation pulse voltage (75kV).

  10. Effect of Yttrium Pre-Implantation on Implantation Behavior of Ti-6Al-4V Alloy in Nitrogen Plasma Immersion Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to increase the peak depth of nitrogen atoms during the nitrogen plasma immersion ion implantation of Ti-6Al-4V alloy, the rare earth metal yttrium was applied. In the experiment, yttrium and nitrogen ions were implanted under the voltage of 20 and 30 kV, respectively. In the samples with yttrium pre-implantation for 30 min, the Auger electron spectroscopy(AES) analysis shows that the peak depth of the nitrogen atoms increases from 50 up to 100 nm. It can also be seen from the tribological tests that the wear resistance of these samples is increased remarkably.

  11. A Revival of Waste: Atmospheric Pressure Nitrogen Plasma Jet Enhanced Jumbo Silicon/Silicon Carbide Composite in Lithium Ion Batteries.

    Science.gov (United States)

    Chen, Bing-Hong; Chuang, Shang-I; Liu, Wei-Ren; Duh, Jenq-Gong

    2015-12-30

    In this study, a jumbo silicon/silicon carbide (Si/SiC) composite (JSC), a novel anode material source, was extracted from solar power industry cutting waste and used as a material for lithium-ion batteries (LIBs), instead of manufacturing the nanolized-Si. Unlike previous methods used for preventing volume expansion and solid electrolyte interphase (SEI), the approach proposed here simply entails applying surface modification to JSC-based electrodes by using nitrogen-atmospheric pressure plasma jet (N-APPJ) treatment process. Surface organic bonds were rearranged and N-doped compounds were formed on the electrodes through applying different plasma treatment durations, and the qualitative examinations of before/after plasma treatment were identified by X-ray photoelectron spectroscopy (XPS) and electron probe microanalyzer (EPMA). The surface modification resulted in the enhancement of electrochemical performance with stable capacity retention and high Coulombic efficiency. In addition, depth profile and scanning electron microscope (SEM) images were executed to determine the existence of Li-N matrix and how the nitrogen compounds change the surface conditions of the electrodes. The N-APPJ-induced rapid surface modification is a major breakthrough for processing recycled waste that can serve as anode materials for next-generation high-performance LIBs.

  12. Urea transporters and sweat response to uremia.

    Science.gov (United States)

    Keller, Raymond W; Bailey, James L; Wang, Yanhua; Klein, Janet D; Sands, Jeff M

    2016-06-01

    In humans, urea is excreted in sweat, largely through the eccrine sweat gland. The urea concentration in human sweat is elevated when compared to blood urea nitrogen. The sweat urea nitrogen (UN) of patients with end-stage kidney disease (ESRD) is increased when compared with healthy humans. The ability to produce sweat is maintained in the overwhelming majority of ESRD patients. A comprehensive literature review found no reports of sweat UN neither in healthy rodents nor in rodent models of chronic kidney disease (CKD). Therefore, this study measured sweat UN concentrations in healthy and uremic rats. Uninephrectomy followed by renal artery ligation was used to remove 5/6 of renal function. Rats were then fed a high-protein diet to induce uremia. Pilocarpine was used to induce sweating. Sweat droplets were collected under oil. Sweat UN was measured with a urease assay. Serum UN was measured using a fluorescent ortho-pthalaldehyde reaction. Immunohistochemistry (IHC) was accomplished with a horseradish peroxidase and diaminobenzidine technique. Sweat UN in uremic rats was elevated greater than two times compared to healthy pair-fed controls (220 ± 17 and 91 ± 15 mmol/L, respectively). Post hoc analysis showed a significant difference between male and female uremic sweat UN (279 ± 38 and 177 ± 11 mmol/L, respectively.) IHC shows, for the first time, the presence of the urea transporters UT-B and UT-A2 in both healthy and uremic rat cutaneous structures. Future studies will use this model to elucidate how rat sweat UN and other solute excretion is altered by commonly prescribed diuretics.

  13. Experience of high-nitrogenous steel powder application in repairs and surface hardening of responsible parts for power equipment by plasma spraying

    Science.gov (United States)

    Kolpakov, A. S.; Kardonina, N. I.

    2016-02-01

    The questions of the application of novel diffusion-alloying high-nitrogenous steel powders for repair and surface hardening of responsible parts of power equipment by plasma spraying are considered. The appropriateness of the method for operative repair of equipment and increasing its service life is justified. General data on the structure, properties, and manufacture of nitrogen-, aluminum-, and chromium-containing steel powders that are economically alloyed using diffusion are described. It is noted that the nitrogen release during the decomposition of iron nitrides, when heating, protects the powder particles from oxidation in the plasma jet. It is shown that the coating retains 50% of nitrogen that is contained in the powder. Plasma spraying modes for diffusion-alloying high-nitrogenous steel powders are given. The service properties of plasma coatings based on these powders are analyzed. It is shown that the high-nitrogenous steel powders to a nitrogen content of 8.9 wt % provide the necessary wear resistance and hardness of the coating and the strength of its adhesion to the substrate and corrosion resistance to typical aggressive media. It is noted that increasing the coating porosity promotes stress relaxation and increases its thickness being limited with respect to delamination conditions in comparison with dense coatings on retention of the low defectiveness of the interface and high adhesion to the substrate. The examples of the application of high-nitrogenous steel powders in power engineering during equipment repairs by service companies and overhaul subdivisions of heat power plants are given. It is noted that the plasma spraying of diffusion-alloyed high-nitrogenous steel powders is a unique opportunity to restore nitrided steel products.

  14. Effect of nitrogen-containing plasma on adherence, friction, and wear of radiofrequency-sputtered titanium carbide coatings

    Science.gov (United States)

    Brainard, W. A.; Wheeler, D. R.

    1979-01-01

    Friction and wear experiments on 440C steel surfaces that were rf sputtered with titanium carbide when a small percentage of nitrogen was added to the plasma were conducted. Both X-ray photoelectron spectroscopy and X-ray diffraction were used to analyze the resultant coatings. Results indicate that the small partial pressure of nitrogen (approximately 0.5 percent) markedly improves the adherence, friction, and wear properties when compared with coatings applied to sputter-etched surfaces, oxidized surfaces, or in the presence of a small oxygen partial pressure. The improvements are related to the formation of an interface containing a mixture of the nitrides of titanium and iron, which are harder than their corresponding oxides.

  15. Use of a nitrogen-argon plasma to improve adherence of sputtered titanium carbide coatings on steel

    Science.gov (United States)

    Brainard, W. A.; Wheeler, D. R.

    1979-01-01

    Friction and wear experiments on 440-C steel surfaces that had been RF-sputtered with titanium carbide when a small percentage of nitrogen was added to the plasma were conducted. X-ray photoelectron spectroscopy and X-ray diffraction were used to analyze the resultant coatings. Results indicate that a small partial pressure of nitrogen (about 0.5%) markedly improves the adherence, friction, and wear properties when compared with coatings applied on sputter-etched oxidized surfaces or in the presence of a small oxygen partial pressure. The improvements are related to the formation of an interface containing a mixture of the nitrides of titanium and iron, which are harder than their corresponding oxides.

  16. Effect of hydrogen addition on the deposition of titanium nitride thin films in nitrogen added argon magnetron plasma

    Science.gov (United States)

    Saikia, P.; Bhuyan, H.; Diaz-Droguett, D. E.; Guzman, F.; Mändl, S.; Saikia, B. K.; Favre, M.; Maze, J. R.; Wyndham, E.

    2016-06-01

    The properties and performance of thin films deposited by plasma assisted processes are closely related to their manufacturing techniques and processes. The objective of the current study is to investigate the modification of plasma parameters occurring during hydrogen addition in N2  +  Ar magnetron plasma used for titanium nitride thin film deposition, and to correlate the measured properties of the deposited thin film with the bulk plasma parameters of the magnetron discharge. From the Langmuir probe measurements, it was observed that the addition of hydrogen led to a decrease of electron density from 8.6 to 6.2  ×  (1014 m-3) and a corresponding increase of electron temperature from 6.30 to 6.74 eV. The optical emission spectroscopy study reveals that with addition of hydrogen, the density of argon ions decreases. The various positive ion species involving hydrogen are found to increase with increase of hydrogen partial pressure in the chamber. The thin films deposited were characterized using standard surface diagnostic tools such as x-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), x-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Although it was possible to deposit thin films of titanium nitride with hydrogen addition in nitrogen added argon magnetron plasma, the quality of the thin films deteriorates with higher hydrogen partial pressures.

  17. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  18. Effects of Nitrification Inhibitors and Sulphur Coated Urea(SCU)on Different Nitrogen Sources and Wheat Yield%几种硝化抑制剂和包硫尿素(SCU)对土壤N素形态和小麦产量的影响

    Institute of Scientific and Technical Information of China (English)

    李永强; 王雅楣; 杨越超; 贾继文; 解璐晗; 姚瑶; 焦树英

    2016-01-01

    Nitrogen is essential for plant growth and health, and it is also a limiting factor for the growth in most agricultural systems. Intensive N fertilizer application has become the traditional habit for agricultural producers in China because of its importance to plant productivity and agricultural land profitability. But some problems have appeared with the increase of the amount of nitrogen fertilizer applied, urea used in crops is easy to lose from volatilization or leaching. Therefore, current crop management practices lead to a highly nitrifying soil environments. Nitrogen emission is the main source of soil acidity and environmental pollution. Several methods for the use of slow controlled release urea have been reported to be used to control the pollution and to enhance nitrogen use efficiency. There is a growing interest in the formulations ofcoated chemical fertilizers with both urease inhibitor and nitrification inhibitor. Urease inhibitor and nitrification inhibitor may improve urea N-use efficiency and minimize N losses by gaseous emissions of ammonia(NH3)to the atmosphere and nitrate(NO-3)leaching into the surface and ground water. Dicyandiamide(DCD)is a nitrification inhibitor that has been studied for many years, it can effectively inhibit nitrification and N2O emission in many agricultural ecosystems. However, limited information is available on the use of the combination of nitrification inhibitor and urease inhibitor applied with urea fertilizer, especially for thiourea(THU)and thiourea formaldehyde resin(TFR)applications. Therefore the purpose of this study is to investigate the effect of urea with different inhibitors to improve the efficiency of nitrogen utilization. A field pot experiment was conducted to explore how to increase the concentration of DCD/THU/TFR/sulfur-coated urea(SCU)to affect the transformation of soil nitrogen and wheat yield. The experiment was designed for twelve treatments which included no nitrogen(CK), only urea, SCU and

  19. Hypochlorite-induced damage to plasma and proteins: formation of nitrogen-centred radicals and their role in protein oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, C.L.; Davies, M.J. [Heart Research Institute, Camperdown, NSW (Australia)

    1998-12-31

    The respiratory burst of activated phagocyte cells results in the generation of hypochlorite (HOCl) via the release of the hydrogen peroxide and the enzyme myeloperoxidase. Little information is available about the mechanisms and intermediates involved in these reactions. Electron paramagnetic resonance (EPR) spectroscopy with spin trapping has been employed to identify radicals formed in fresh human plasma and isolated proteins and peptides on treatment with HOCI. Reaction of plasma with HOCI in the presence of a spin trap gives broad, anisotropic radical adducts consistent with the formation of large, slowly-tumbling, protein-derived radicals. The identity of the plasma-derived radical adducts was investigated further by the incubation of the pre-formed adducts with the non-specific proteolytic enzyme pronase. This treatment gave sharper, signals consistent with the release of more mobile, low-molecular-weight spin adducts from the initial protein-derived adducts. The hyperfine couplings of these sharper signals are characteristic of the formation of nitrogen-centred radical adducts. Similar or identical species are observed on treatment with isolated human serum albumin, suggesting that this is a major site of HOCI-induced oxidation. Reaction of HOCI-treated plasma or isolated proteins/peptides with excess methionine eliminates radical formation, consistent with lysine-derived chloramines (via homolysis or heterolysis of N-CI bonds) being the radical source. The effect of HOCI on the structural integrity of the plasma proteins was investigated by SDS-PAGE. It was demonstrated that incubation of HOCI-treated plasma or proteins, after removal of excess oxidant, resulted in a time- and HOCI-dependent fragmentation of the proteins. No evidence was obtained for the presence of either discrete fragments or aggregated material. This suggests that the reaction of HOCI with plasma proteins results in the formation of a large number of random fragments. Treatment with

  20. Molecular evolution of urea amidolyase and urea carboxylase in fungi

    Directory of Open Access Journals (Sweden)

    Harris Steven D

    2011-03-01

    Full Text Available Abstract Background Urea amidolyase breaks down urea into ammonia and carbon dioxide in a two-step process, while another enzyme, urease, does this in a one step-process. Urea amidolyase has been found only in some fungal species among eukaryotes. It contains two major domains: the amidase and urea carboxylase domains. A shorter form of urea amidolyase is known as urea carboxylase and has no amidase domain. Eukaryotic urea carboxylase has been found only in several fungal species and green algae. In order to elucidate the evolutionary origin of urea amidolyase and urea carboxylase, we studied the distribution of urea amidolyase, urea carboxylase, as well as other proteins including urease, across kingdoms. Results Among the 64 fungal species we examined, only those in two Ascomycota classes (Sordariomycetes and Saccharomycetes had the urea amidolyase sequences. Urea carboxylase was found in many but not all of the species in the phylum Basidiomycota and in the subphylum Pezizomycotina (phylum Ascomycota. It was completely absent from the class Saccharomycetes (phylum Ascomycota; subphylum Saccharomycotina. Four Sordariomycetes species we examined had both the urea carboxylase and the urea amidolyase sequences. Phylogenetic analysis showed that these two enzymes appeared to have gone through independent evolution since their bacterial origin. The amidase domain and the urea carboxylase domain sequences from fungal urea amidolyases clustered strongly together with the amidase and urea carboxylase sequences, respectively, from a small number of beta- and gammaproteobacteria. On the other hand, fungal urea carboxylase proteins clustered together with another copy of urea carboxylases distributed broadly among bacteria. The urease proteins were found in all the fungal species examined except for those of the subphylum Saccharomycotina. Conclusions We conclude that the urea amidolyase genes currently found only in fungi are the results of a horizontal

  1. Structure and permeation mechanism of a mammalian urea transporter

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Elena J.; Cao, Yu; Enkavi, Giray; Quick, Matthias; Pan, Yaping; Tajkhorshid, Emad; Zhou, Ming (UIUC); (Columbia)

    2012-09-17

    As an adaptation to infrequent access to water, terrestrial mammals produce urine that is hyperosmotic to plasma. To prevent osmotic diuresis by the large quantity of urea generated by protein catabolism, the kidney epithelia contain facilitative urea transporters (UTs) that allow rapid equilibration between the urinary space and the hyperosmotic interstitium. Here we report the first X-ray crystal structure of a mammalian UT, UT-B, at a resolution of 2.36 {angstrom}. UT-B is a homotrimer and each protomer contains a urea conduction pore with a narrow selectivity filter. Structural analyses and molecular dynamics simulations showed that the selectivity filter has two urea binding sites separated by an approximately 5.0 kcal/mol energy barrier. Functional studies showed that the rate of urea conduction in UT-B is increased by hypoosmotic stress, and that the site of osmoregulation coincides with the location of the energy barrier.

  2. Suplementação nitrogenada com ureia comum ou encapsulada sobre parâmetros ruminais de novilhos alimentados com feno de baixa qualidade Nitrogen supplement with common or coated urea on ruminal parameters of steers fed with low quality hay

    Directory of Open Access Journals (Sweden)

    Eduardo Bohrer de Azevedo

    2010-03-01

    Full Text Available Foi realizado um experimento de suplementação com novilhos fistulados no rúmen com o objetivo de verificar a utilização de ureia encapsulada como fonte de nitrogênio de liberação mais lenta e uniforme ao longo do tempo, bem como seu efeito sobre a degradabilidade da parede celular do feno. Os tratamentos foram: Feno + sal mineralizado (SM; Feno + suplemento proteico com ureia comum (SU; Feno + suplemento proteico com ureia encapsulada fórmula 1 (UE1; e Feno + suplemento proteico com ureia encapsulada fórmula 2 (UE2. O volumoso utilizado foi feno de Tifton (Cynodon dactylon L. de baixa qualidade (PB: 4,62% e FDN: 83,46%. Foram realizadas medidas de pH e N-NH3 ruminais e parâmetros de degradação ruminal da FDN do volumoso. Verificou-se efeito (P0,05 da ureia comum. Os valores de pH e degradabilidade in situ não foram afetados pelos tratamentos (P>0,05, ao serem comparados os suplementados ou não suplementados com proteína degradável no rúmen e ao serem comparadas fontes de nitrogênio não proteico. A ureia encapsulada não demonstrou superioridade sobre a ureia comum, provavelmente pela baixa eficiência da sua proteção. A utilização de ureia encapsulada e a suplementação de proteína degradável não foram eficientes em aumentar a degradabilidade da parede celular do volumoso utilizado.A supplementation trial was accomplished with rumen fistulated steers with the objective of verifying the coated urea use as a source of nitrogen of slower and uniform release throughout the time, as well as its effect on cellular wall degradability. The treatments were: hay + mineral supplement; hay + protein supplement with common urea; hay + protein supplement with coated urea formula 1; hay + protein supplement with coated urea formula 2. The forage used was Tifton (Cynodon dactylon L. hay of low quality (CP: 4.62% and NDF: 83.46%. The measures were: ruminal pH and N-NH3, rumen degradability of NDF and ruminal degradation parameters

  3. Urea-N recycling in lactating dairy cows fed diets with 2 different levels of dietary crude protein and starch with or without monensin.

    Science.gov (United States)

    Recktenwald, E B; Ross, D A; Fessenden, S W; Wall, C J; Van Amburgh, M E

    2014-03-01

    Rumensin (monensin; Elanco Animal Health, Greenfield, IN) has been shown to reduce ammonia production and microbial populations in vitro; thus, it would be assumed to reduce ruminal ammonia production and subsequent urea production and consequently affect urea recycling. The objective of this experiment was to determine the effects of 2 levels of dietary crude protein (CP) and 2 levels of starch, with and without Rumensin on urea-N recycling in lactating dairy cattle. Twelve lactating Holstein dairy cows (107 ± 21 d in milk, 647 kg ± 37 kg of body weight) were fed diets characterized as having high (16.7%) or low (15.3%) CP with or without Rumensin, while dietary starch levels (23 vs. 29%) were varied between 2 feeding periods with at least 7d of adaptation between measurements. Cows assigned to high or low protein and to Rumensin or no Rumensin remained on those treatments to avoid carryover effects. The diets consisted of approximately 40% corn silage, 20% alfalfa hay, and 40% concentrate mix specific to the treatment diets, with 0.5 kg of wheat straw added to the high starch diets to enhance effective fiber intake. The diets were formulated using Cornell Net Carbohydrate and Protein System (version 6.1), and the low-protein diets were formulated to be deficient for rumen ammonia to create conditions that should enhance the demand for urea recycling. The high-protein diets were formulated to be positive for both rumen ammonia and metabolizable protein. Rumen fluid, urine, feces, and milk samples were collected before and after a 72-h continuous jugular infusion of (15)N(15)N-urea. Total urine and feces were collected during the urea infusions for N balance measurements. Milk yield and dry matter intake were improved in cows fed the higher level of dietary CP and by Rumensin. Ruminal ammonia and milk and plasma urea nitrogen concentrations corresponded to dietary CP concentration. As has been shown in vitro, Rumensin reduced rumen ammonia concentration by

  4. 硫膜和树脂膜控释尿素对小麦产量、品质及氮素利用率的影响%Effects of sulfur-and polymer-coated controlled release urea fertilizers on wheat yield and quality and fertilizer nitrogen use efficiency

    Institute of Scientific and Technical Information of China (English)

    马富亮; 宋付朋; 高杨; 邹朋

    2012-01-01

    通过田间试验,研究了硫膜和树脂膜控释尿素对小麦产量、品质和耕层土壤无机氮含量及氮素利用率的影响.结果表明:与普通尿素相比,硫膜和树脂膜控释尿素均能显著提高小麦籽粒产量和品质,增产幅度达10.4%~16.5%,小麦籽粒蛋白质和淀粉含量分别提高5.8%~18.9%和0.3%~1.4%;两种控释肥均能有效保持耕层土壤无机氮含量,且其氮素后移的功效满足了小麦生育后期对氮素的需求;有效提高了氮肥偏生产力,降低了土壤氮素依存率(降幅11.0% ~17.3%),提高了氮素利用率(增幅58.2%~101.2%).其中,树脂膜控释尿素比硫膜控释尿素表现出更好的增产效应,实现了氮素的高效利用.%A field experiment was conducted to study the effects of sulfur- and polymer-coated controlled release urea fertilizers on wheat yield and its quality, plow layer soil inorganic nitrogen (N) contents, and fertilizer N use efficiency. Compared with traditional urea fertilizer, both sulfur- and polymer-coated controlled release urea fertilizers increased the grain yield by 10.4% -16. 5% , and the grain protein and starch contents by 5. 8% -18. 9% and 0. 3% -1. 4% , respectively. The controlled release urea fertilizers could maintain the topsoil inorganic N contents to meet the N requirement for the wheat, especially during its late growth stage. In the meantime, the fertilizer N use efficiency was improved by 58. 2% —101. 2% . Polymer-coated urea produced better wheat yield and higher fertilizer N use efficiency, compared with sulfur-coated controlled release urea.

  5. Influence Factors of Nitrogen Release Characteristics of Urea Coated with Styrene-acrylate Emulsion,Paraffin Wax and Attapulgite%影响苯丙乳液-石蜡-凹凸棒石复合包膜尿素缓释效果因素的探讨

    Institute of Scientific and Technical Information of China (English)

    张雁; 彭书传; 陈天虎; 周正发

    2011-01-01

    [目的]改进笨丙乳液-石蜡-凹凸棒石复合包膜尿素的生产技术.[方法]通过分别改变各种包膜材料(苯丙乳液、石蜡和凹凸棒石粉末)的用量、干燥时间以及干燥温度,制得不同的苯丙乳液-石蜡-凹凸棒石复合包膜尿素,并且利用水浸泡试验研究制得的不同包膜尿素在水中的溶解特征.[结果]苯丙乳液-石蜡-凹凸棒石复合包膜尿素的制备最佳工艺参数为:每包膜100克尿素,石蜡用量为20 g,凹凸棒石粘土用量为3g,苯丙乳液用量为50~60ml,干燥温度为60℃,干燥时间为120 min.[结论]各种膜材料用量、干燥时间以及干燥温度均影响着该复合包膜尿素的缓释效果.%[Objective] The research aimed to improve the production technology of urea coated with styrene-acrylate emulsion, paraffin wax and attapulgite. [ Method] Different kinds of controlled-release coated urea were prepared from normal urea by coating with styrene-acrylate e-mulsion, paraffin wax and attapulgite by changing coating material. Consumptions, drying time and drying temperature. Their nitrogen slow-release characteristics were investigated by water immersion research. [ Result] The best process parameters of the urea coated with styrene-acrylate emulsion, paraffin wax and attapulgite preparation were as follows: in 100 grams urea per parcel, the amount of paraffin wax was 20 grams, attapulgite was 3 grams, the amount of styrene-acrylic emulsion was 50-60 ml, drying temperature was 60 oC, and the drying time was 120 minutes. [Conclusion]Coating material (styrene-acrylate emulsion, paraffin wax and attapulgite) consumptions, drying time and drying temperature influenced the coated urea's slow release effect.

  6. Final report of the safety assessment of Urea.

    Science.gov (United States)

    2005-01-01

    Although Urea is officially described as a buffering agent, humectant, and skin-conditioning agent-humectant for use in cosmetic products, there is a report stating that Urea also is used in cosmetics for its desquamating and antimicrobial action. In 2001, the Food and Drug Administration (FDA) reported that Urea was used in 239 formulations. Concentrations of use for Urea ranged from 0.01% to 10%. Urea is generally recognized as safe by FDA for the following uses: side-seam cements for food contact; an inhibitor or stabilizer in pesticide formulations and formulations applied to animals; internal sizing for paper and paperboard and surface sizing and coating of paper and paper board that contact water-in-oil dairy emulsions, low-moisture fats and oils, moist bakery products, dry solids with surface containing no free fats or oil, and dry solids with the surface of fat or oil; and to facilitate fermentation of wine. Urea is the end product of mammalian protein metabolism and the chief nitrogenous compound of urine. Urea concentrations in muscle, liver, and fetuses of rats increased after a subcutaneous injection of Urea. Urea diffused readily through the placenta and into other maternal and fetal organs. The half-life of Urea injected into rabbits was on the order of several hours, and the reutilization rate was 32.2% to 88.8%. Urea given to rats by a bolus injection or continuous infusion resulted in distribution to the following brain regions: frontal lobe, caudate nucleus, hippocampus, thalamus plus hypothalamus, pons and white matter (corpus callosum). The permeability constant after treatment with Urea of whole skin and the dermis of rabbits was 2.37 +/- 0.13 (x 10(6)) and 1.20 +/- 0.09 (x10(3)) cm/min, respectively. The absorption of Urea across normal and abraded human skin was 9.5% +/- 2.3% and 67.9% +/- 5.6%, respectively. Urea increased the skin penetration of other compounds, including hydrocortisone. No toxicity was observed for Urea at levels as high

  7. Tritium inventory control during ITER operation under carbon plasma-facing components by nitrogen-based plasma chemistry: a review

    Science.gov (United States)

    Tabarés, F. L.

    2013-06-01

    In spite of being highly suited for advanced plasma performance operation of tokamaks, as demonstrated over at least two decades of fusion plasma research, carbon is not currently considered as an integrating element of the plasma-facing components (PFCs) for the active phase of ITER. The main reason preventing its use under the very challenging scenarios foreseen in this phase, with edge-localized modes delivering several tens of MW m-2 to the divertor target every second or less, is the existing concern about reaching the tritium inventory value of 1000 g used in safety assessments in a time shorter than the projected lifetime of the divertor materials eroded by the plasma, set at 3000 shots. Although several mechanisms of tritium trapping in carbon components have been identified, co-deposition of the carbon radicals arising from chemically eroded chlorofluorocarbons in remote areas appears to play a dominant role. Several possible ways to keep control of the tritium build-up during the full operation of ITER have been put forward, mostly based on the periodic removal of the co-deposits by chemical (thermo-oxidation, plasma chemistry) or physical (laser, flash lamps) methods. In this work, we review the techniques for the inhibition and removal of tritium-rich co-deposits based on the strong chemical reactivity of some N-bearing molecules with carbon. The integration of these techniques into a possible scheme for tritium inventory control in the active phase of ITER under carbon-based PFCs with minimum down-time is discussed and the existing caveats are addressed.

  8. Photoelectrocatalytic properties of nitrogen doped TiO2/Ti photoelectrode prepared by plasma based ion implantation under visible light.

    Science.gov (United States)

    Han, Lei; Xin, Yanjun; Liu, Huiling; Ma, Xinxin; Tang, Guangze

    2010-03-15

    Nitrogen doped TiO(2)/Ti photoelectrodes were prepared by a sequence of anodization and plasma based ion implantation (PBII). The properties of this photoelectrode were characterized by scanning electronic microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), Ultra violet/visible light diffuse reflectance spectra (UV/vis/DRS), surface photovoltage (SPV), etc. Photoelectrocatalytic (PEC) performance of N-doped TiO(2)/Ti photoelectrode was tested under visible light irradiation. Their photocatalytic activity was evaluated by degradation of Rhodamine B (Rh.B). The results of XPS showed that nitrogen element was in form of three species, i.e. beta-N, molecular gamma-N and O-Ti-N, which existed in the lattices of TiO(2) and gaps between molecules. The results of UV/vis/DRS spectra and SPV revealed that proper doping of nitrogen could expand the response of photoelectrodes towards visible light and diminish the recombination of photo-generated holes and electrons, respectively. The photoelectrocatalytic activity of N-doped TiO(2)/Ti photoelectrodes was superior to those of undoped one under visible light region irradiation.

  9. 缓释尿素氮素利用率及肥效试验研究%Experimental Study on the Utilization Rate and Effect of Controlled-release Urea Nitrogen

    Institute of Scientific and Technical Information of China (English)

    邰日晶; 王晓茜

    2014-01-01

    The effect of five kinds of controlled release urea on maize and rice yield was studied adopting contrast test with common urea as the control. The experimental results show that slow release urea can increase the harvest of maize and rice, but the difference was not significant and the 5 slow release ureas can increase the corn fertilizer utilization rate, and the effect is better than that of rice.%为验证缓释尿素的肥料利用率和应用效果,采用对比试验的方法,以普通尿素作对照,研究5种缓释尿素对玉米和水稻产量的影响。试验结果表明,在等养分含量处理条件下,缓释尿素对玉米和水稻两种作物均具有增产作用,但差异不显著;5种缓释尿素都能不能程度地提高玉米的肥料利用率,且效果优于水稻。

  10. Development of a low-cost atmospheric non-thermal plasma jet and its characteristics in air and nitrogen

    Science.gov (United States)

    Allam, Tarek M.; Ahmed, Kamal M.; Abouelatta, Mohamed A.; Ward, Sayed A.; Lashin, Ahmed A.; Soliman, Hanaa M.

    2016-10-01

    This paper deals with the development of a low-cost atmospheric non-thermal plasma jet (ANPJ) which was designed and operated previously in our laboratory. The purpose of the developed design with a small size less than 4% of the previous volume is to obtain a more portable device which holds promise for various fields of applications. The discharge is operated separately with compressed air and nitrogen gas with flow rates varied within the range of 3-18 L/min. The plasma plume length and thickness are measured as a function of the gas flow rate and input voltage Vinput within the range of 3-18 L/min and 2-6 kV respectively. The results showed that for nitrogen gas, the maximum values of the plume length and thickness are 20 mm and 1.3 mm respectively at a flow rate of 12 L/min and Vinput = 6 kV. Results of electrical characterization at Vinput = 6 kV such as discharge voltage, discharge current, the mean consumed power and energy showed that the maximum values of these parameters are obtained at a flow rate of 12 L/min. The developed design is found to be saving up to 65.47% and 68.54% of the consumed power compared to the previous design in the case of air and N2 respectively. The new proposed configuration for the developed ANPJ offers more suitable characteristics than the earlier designs, especially for nitrogen gas.

  11. Cortisol-sensitive urea transport across the gill basolateral membrane of the gulf toadfish (Opsanus beta).

    Science.gov (United States)

    Rodela, Tamara M; Gilmour, Kathleen M; Walsh, Patrick J; McDonald, M Danielle

    2009-08-01

    Gulf toadfish (Opsanus beta) use a unique pulsatile urea excretion mechanism that allows urea to be voided in large pulses via the periodic insertion or activation of a branchial urea transporter. The precise cellular and subcellular location of the facilitated diffusion mechanism(s) remains unclear. An in vitro basolateral membrane vesicle (BLMV) preparation was used to test the hypothesis that urea movement across the gill basolateral membrane occurs through a cortisol-sensitive carrier-mediated mechanism. Toadfish BLMVs demonstrated two components of urea uptake: a linear element at high external urea concentrations, and a phloretin-sensitive saturable constituent (K(m) = 0.24 mmol/l; V(max) = 6.95 micromol x mg protein(-1) x h(-1)) at low urea concentrations ( 2, further suggestive of carrier-mediated processes. Our data provide evidence that a basolateral urea facilitated transporter accelerates the movement of urea between the plasma and gills to enable the pulsatile excretion of urea. Furthermore, in vivo infusion of cortisol caused a significant 4.3-fold reduction in BLMV urea transport capacity in lab-crowded fish, suggesting that cortisol inhibits the recruitment of urea transporters to the basolateral membrane, which may ultimately affect the size of the urea pulse event in gulf toadfish.

  12. Effect of plasma jet diameter on the efficiency of reactive oxygen and nitrogen species generation in water

    Science.gov (United States)

    Oh, Jun-Seok; Kakuta, Maito; Furuta, Hiroshi; Akatsuka, Hiroshi; Hatta, Akimitsu

    2016-06-01

    The plasma jet generation of reactive oxygen and nitrogen species (RONS) in solution is important in biology, medicine, and disinfection. Studies using a wide variety of plasma jet devices have been carried out for this purpose, making it difficult to compare the performance between devices. In this study, we compared the efficiency of RONS generation in deionized (DI) water between 3.7-mm- and 800-µm-sized helium (He) plasma jets (hereafter mm-jet and µm-jet, respectively) at different treatment distances and times. The efficiency of RONS generation was determined by considering the total amount of RONS generated in DI water with respect to the input energy and gas consumption. We found that the mm-jet generated 20% more RONS in the DI water than the µm-jet at the optimized distance. However, when the input power and He gas consumption were taken into account, we discovered that the µm-jet was 5 times more efficient in generating RONS in the DI water. Under the parameters investigated in this study, the concentration of RONS continued to increase as a function of treatment time (up to 30 min). However treatment distance had a marked effect on the efficiency of RONS generation: treatment distances of 25 and 30 mm were optimal for the mm-jet and µm-jet, respectively. Our method of comparing the efficiency of RONS generation in solution between plasma jets could be used as a reference protocol for the development of efficient plasma jet sources for use in medicine, biology, and agriculture.

  13. Comparison of the behavior of fibroblast and bone marrow-derived mesenchymal stem cell on nitrogen plasma-treated gelatin films

    Energy Technology Data Exchange (ETDEWEB)

    Prasertsung, I. [Chemical Engineering Program, Department of Industrial Engineering, Faculty of Engineering, Naresuan University, Phitsanulok 65000 (Thailand); Research Unit on Functionalized Material for Chemical, Biochemical and Biomedical Technology, Faculty of Engineering, Naresuan University, Phitsanulok 65000 (Thailand); Kanokpanont, S. [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330 (Thailand); Mongkolnavin, R. [Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Plasma Technology and Nuclear Fusion Research Unit, Chulalongkorn University, Bangkok 10330 (Thailand); Wong, C.S. [Plasma Technology Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Panpranot, J. [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330 (Thailand); Damrongsakkul, S., E-mail: siriporn.d@chula.ac.th [Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330 (Thailand); Plasma Technology and Nuclear Fusion Research Unit, Chulalongkorn University, Bangkok 10330 (Thailand)

    2013-10-01

    The attachment and growth behavior of mouse fibroblast (L929) and rat bone marrow-derived mesenchymal stem cell (MSC) on nitrogen plasma-treated and untreated gelatin films was investigated and compared. The gelatin films were prepared by solution casting (0.05% w/v) and crosslinked using dehydrothermal treatment. The crosslinked gelatin films were treated with nitrogen alternating current (AC) 50 Hz plasma systems at various treatment time. The results on the attachment and growth of two cells; L929 and MSC, on plasma-treated gelatin film showed that the number of attached and proliferated cells on plasma-treated gelatin films was significantly increased compared to untreated samples. However, no significant difference between the number of attached L929 and MSC on plasma-treated gelatin was observed. The shorter population doubling time and higher growth rate of cells cultured on plasma-treated film indicated the greater growth of cells, compared to ones on untreated films. The greatest enhancement of cell attachment and growth were noticed when the film was treated with nitrogen plasma for 9 to 15 s. This suggested that the greater attachment and growth of both cells on gelatin films resulted from the change of surface properties, i.e. hydrophilicity, surface energy, and chemistry. The suitable water contact angle and oxygen/nitrogen ratio (O/N) of gelatin film for best L929 and MSC attachment were observed at 27–32° and 1.4, respectively. These conditions also provided the best proliferation of cells on plasma-treated gelatin films. - Highlights: • We compared the attachment and growth behavior of L929 and MSC. • The attachment of two cells on plasma-treated gelatin was significantly increased. • The shorter population doubling time and higher growth rate of cells were observed. • L929 fibroblast exhibited the greater proliferation, compared to MSC.

  14. Fertilización de maíz con urea de liberación lenta: pérdida por volatilización y eficiencia de uso de nitrógeno Corn fertilization with slow-solubilization urea: ammonia volatilization losses and nitrogen use efficiency

    OpenAIRE

    PA Barbieri; HE Echeverría; HR Saínz Rozas; M Maringolo

    2010-01-01

    Las pérdidas de nitrógeno (N) reducen la eficiencia de uso de dicho nutriente (EUN). Se han desarrollado productos tales como el copolímero maleico-itacónico (NSN) y triamida N-(n-butil) tiofosfórica (nBTPT) que agregados a la urea disminuyen la tasa de liberación de N pudiendo reducir las pérdidas. El objetivo fue determinar durante dos años las pérdidas por volatilización de N-NH3, la respuesta en rendimiento, el N en grano y la EUN del cultivo de maíz bajo SD desde urea tratada con dichos ...

  15. Hydrogen production via urea electrolysis using a gel electrolyte

    Science.gov (United States)

    King, Rebecca L.; Botte, Gerardine G.

    2011-03-01

    A technology was demonstrated for the production of hydrogen and other valuable products (nitrogen and clean water) through the electrochemical oxidation of urea in alkaline media. In addition, this process remediates toxic nitrates and prevents gaseous ammonia emissions. Improvements to urea electrolysis were made through replacement of aqueous KOH electrolyte with a poly(acrylic acid) gel electrolyte. A small volume of poly(acrylic acid) gel electrolyte was used to accomplish the electrochemical oxidation of urea improving on the previous requirement for large amounts of aqueous potassium hydroxide. The effect of gel composition was investigated by varying polymer content and KOH concentrations within the polymer matrix in order to determine which is the most advantageous for the electrochemical oxidation of urea and production of hydrogen.

  16. A comparative study of nitrogen plasma effect on field emission characteristics of single wall carbon nanotubes synthesized by plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Kumar, Avshish; Parveen, Shama; Husain, Samina; Ali, Javid; Zulfequar, Mohammad; Harsh; Husain, Mushahid

    2014-12-01

    Vertically aligned single wall carbon nanotubes (SWCNTs) with large scale control of diameter, length and alignment have successfully been grown by plasma enhanced chemical vapor deposition (PECVD) system. The nickel (Ni) as catalyst deposited on silicon (Si) substrate was used to grow the SWCNTs. Field emission (FE) characteristics of the as grown SWCNTs were measured using indigenously designed setup in which a diode is configured in such a way that by applying negative voltage on the copper plate (cathode) with respect to stainless steel anode plate, current density can be recorded. To measure the FE characteristics, SWCNTs film pasted on the copper plate with silver epoxy was used as electron emitter source. The effective area of anode was ∼78.5 mm2 for field emission measurements. The emission measurements were carried out under high vacuum pressure of the order of 10-6 Torr to minimize the electron scattering and degradation of the emitters. The distance between anode and cathode was kept 500 μm (constant) during entire field emission studies. The grown SWCNTs are excellent field emitters, having emission current density higher than 25 mA/cm2 at turn-on field 1.3 V/μm. In order to enhance the field emission characteristics, the as grown SWCNTs have been treated under nitrogen (N2) plasma for 5 min and again field emission characteristics have been measured. The N2 plasma treated SWCNTs show a good enhancement in the field emission properties with emission current density 81.5 mA/cm2 at turn on field 1.2 V/μm. The as-grown and N2 plasma treated SWCNTs were also characterized by field emission scanning electron microscope (FESEM), high resolution transmission electron microscope (HRTEM), Raman spectrometer, Fourier transform infrared spectrometer (FTIR) and X-ray photoelectron spectroscopy (XPS).

  17. Combined effect of protein and oxygen on reactive oxygen and nitrogen species in the plasma treatment of tissue

    Science.gov (United States)

    Gaur, Nishtha; Szili, Endre J.; Oh, Jun-Seok; Hong, Sung-Ha; Michelmore, Andrew; Graves, David B.; Hatta, Akimitsu; Short, Robert D.

    2015-09-01

    The influence of protein and molecular, ground state oxygen (O2) on the plasma generation, and transport of reactive oxygen and nitrogen species (RONS) in tissue are investigated. A tissue target, comprising a 1 mm thick gelatin film (a surrogate for real tissue), is placed on top of a 96-well plate; each well is filled with phosphate buffered saline (PBS, pH 7.4) containing one fluorescent or colorimetric reporter that is specific for one of three RONS (i.e., H2O2, NO2-, or OH•) or a broad spectrum reactive oxygen species reporter (2,7-dichlorodihydrofluorescein). A helium cold atmospheric plasma (CAP) jet contacts the top of the gelatin surface, and the concentrations of RONS generated in PBS are measured on a microplate reader. The data show that H2O2, NO2-, or OH• are generated in PBS underneath the target. Independently, measurements are made of the O2 concentration in the PBS with and without the gelatin target. Adding bovine serum albumin protein to the PBS or gelatin shows that protein either raises or inhibits RONS depending upon the O2 concentration. Our results are discussed in the context of plasma-soft tissue interactions that are important in the development of CAP technology for medicine, biology, and food manufacturing.

  18. Investigation of bonded hydrogen defects in nanocrystalline diamond films grown with nitrogen/methane/hydrogen plasma at high power conditions

    Science.gov (United States)

    Tang, C. J.; Hou, Haihong; Fernandes, A. J. S.; Jiang, X. F.; Pinto, J. L.; Ye, H.

    2017-02-01

    In this work, we investigate the influence of some growth parameters such as high microwave power ranging from 3.0 to 4.0 kW and N2 additive on the incorporation of bonded hydrogen defects in nanocrystalline diamond (NCD) films grown through a small amount of pure N2 addition into conventional 4% CH4/H2 plasma using a 5 kW microwave plasma CVD system. Incorporation form and content of hydrogen point defects in the NCD films produced with pure N2 addition was analyzed by employing Fourier-transform infrared (FTIR) spectroscopy for the first time. A large amount of hydrogen related defects was detected in all the produced NCD films with N2 additive ranging from 29 to 87 μm thick with grain size from 47 nm to 31 nm. Furthermore, a specific new H related sharp absorption peak appears in all the NCD films grown with pure N2/CH4/H2 plasma at high powers and becomes stronger at powers higher than 3.0 kW and is even stronger than the 2920 cm-1 peak, which is commonly found in CVD diamond films. Based on these experimental findings, the role of high power and pure nitrogen addition on the growth of NCD films including hydrogen defect formation is analyzed and discussed.

  19. Dependence of composition of stable molecules in N2-H2 plasmas on nitrogen gas flow rate ratio measured using a quartz sensor

    Science.gov (United States)

    Suzuki, Atsushi; Asahina, Shuichi

    2014-11-01

    Compositions of stable molecules in N2-H2 plasmas measured using a quartz sensor (Q-sensor) were compared with those measured using a quadrupole mass spectrometer (QMS) under various nitrogen gas flow rate ratio to determine the applicability of Q-sensor measurement to N2-H2 plasmas. The nitrogen flow rate ratio dependence of the Q-sensor results obtained 20 mm from the edge of the plasma electrodes (Z = 20 mm) tended to agree more qualitatively with the NH3 density measured by QMS compared with those measured at 70 mm. For pure nitrogen or hydrogen plasma, the results measured at Z = 20 mm differed from those of gas analyses using QMS. The analysis indicated that Q-sensor results obtained near discharges with various nitrogen flow rate ratios reflect information on stable molecules such as N2, H2, and NH3 but yield information on other stable molecules or other chemical species in pure N2 and H2 plasmas.

  20. Vitamin A deficiency increases protein catabolism and induces urea cycle enzymes in rats.

    Science.gov (United States)

    Esteban-Pretel, Guillermo; Marín, M Pilar; Cabezuelo, Francisco; Moreno, Verónica; Renau-Piqueras, Jaime; Timoneda, Joaquín; Barber, Teresa

    2010-04-01

    Chronic vitamin A deficiency induces a substantial delay in the rates of weight and height gain in both humans and experimental animals. This effect has been associated with an impaired nutrient metabolism and loss of body protein. Therefore, we analyzed the effect of vitamin A deficiency on endogenous proteolysis and nitrogen metabolism and its reversibility with all-trans retinoic acid (RA). Male weanling rats, housed in pairs, were pair-fed a vitamin A-deficient (VAD) or control diet until they were 60 d old. A group of deficient rats were further treated with daily intraperitoneal injections of all-trans RA for 10 d. Final body and tissue (i.e. liver and heart) weights were significantly lower and tissue:body weight ratios were similar in VAD rats and in controls. Conversely, the epididymal white fat:body weight ratio and the plasma concentrations of alanine aminotransferase and adiponectin were significantly higher in VAD rats, which also had hepatic macrovesicular lipid accumulations. Plasma and gastrocnemius muscle 3-methylhistidine, urine nitrogen, and plasma and urine urea concentrations were all significantly higher in the VAD group. The expression of the genes encoding urea cycle enzymes and their activities increased in VAD livers. These changes were partially reverted by all-trans RA. We propose that fuel partitioning in vitamin A deficiency may shift from fatty acids to protein catabolism as an energy source. Our results emphasize the importance of vitamin A on the energy balance control system and they provide an explanation for the role of vitamin A in protein turnover, development, and growth.

  1. Comparative Study of Detection Results of Urea Nitrogen and Creatinine for Five Medical Laboratory%攀枝花市五家医学实验室尿素和肌酐检测结果的比对研究

    Institute of Scientific and Technical Information of China (English)

    李德中; 周讯; 谢华玉; 梁朝坤; 李洪; 张利军; 李朝金

    2015-01-01

    目的:探讨实验室间不同生化检测系统结果的可比性,为推动实验室间检验结果的互认提供参考。方法五家实验室检测病人新鲜血清,连续20次分别测定 Urea 和 Cr 等10个生化项目,进行精密度分析;参照美国临床和实验室标准协会(CLSI )EP9-A2文件,以攀钢集团总医院生化检测系统作为比较系统,其余四家医院生化检测系统作为待评系统,检测病人新鲜血清,均分别检测五个生化组合项目(Urea,Cr),(AST,ALT),(TP,ALB),(TG,TC)和(HDL-C,LDL-C),每个组合项目连续测定5天,测定结果进行比对分析,计算比较系统和待评系统之间的相关系数、直线回归方程和不同医学决定水平处的相对偏倚(SE%),并以美国临床实验室改进修正案能力验证(CLIA’88)允许总误差(TEa)的1/2为标准,判断待评系统与比较系统之间的可比性和临床可接受性。结果以 Urea 和 Cr 测定为例,五家实验室间 Urea 和 Cr 两项目的 CV 值均小于 CLIA’88允许总误差的1/3,精密度均符合要求。检测结果显著相关(r 2>0.975);临床可接受性能评价中,在 Urea 低医学决定水平处,有两家实验室的测定结果为临床不可接受;在 Urea 高医学决定水平处,有一家实验室的测定结果为临床不可接受;在 Cr 低医学决定水平处,有两家实验室的测定结果为临床不可接受;其余待评系统 Urea 和 Cr 项目在各医学决定水平与比较系统比较,其 SE%均小于 CLIA’88允许总误差的1/2,为临床可接受。结论实验室间不同生化检测系统的测定结果存在不同程度的偏倚,部分项目偏倚超出允许误差范围。%Objective To investigate the different biochemical testing system inter laboratory comparability of results,provide reference for promoting inter laboratory test results of the recognition

  2. Recuperação do nitrogênio (15N da uréia e da palhada por soqueira de cana-de-açúcar (Saccharum spp. Recovery of nitrogen (15N from urea and cane trash by sugar cane ratoon (Saccharum spp.

    Directory of Open Access Journals (Sweden)

    G. J. C. Gava

    2003-08-01

    Full Text Available Desenvolveu-se um experimento com vistas em avaliar a utilização do nitrogênio mineralizado da palhada (15N e do nitrogênio da uréia (15N aplicada em soqueira de cana-de-açúcar. O experimento foi desenvolvido em campo, num Argissolo Vermelho-Amarelo (Paleudalf, no município de Piracicaba (SP, de outubro de 1997 a agosto de 1998, e constou de quatro tratamentos: (T1 mistura de vinhaça e uréia aplicada em área total sobre o solo coberto com palhada-15N; (T2 mistura de vinhaça e uréia-15N aplicada em área total sobre o solo coberto com palhada; (T3 mistura de vinhaça e uréia-15N aplicada em área total sobre o solo sem a palhada; (T4 uréia-15N enterrada em sulcos nos dois lados das linhas da cana, com prévia aplicação de vinhaça sobre o solo sem cobertura de palhada. O delineamento experimental foi o de blocos casualizados, com quatro repetições. Comparações de componentes de produtividade da cultura, da acumulação de nitrogênio pela parte aérea e da utilização do nitrogênio da uréia-15N e do mineralizado da palhada-15N, foram realizadas entre os tratamentos. O desenvolvimento vegetal deu-se em um ciclo de 315 dias e foi semelhante nas condições com ou sem palhada de cana-de-açúcar. Do nitrogênio total acumulado na parte aérea da soqueira de cana-de-açúcar, 10 a 16 % foi absorvido do fertilizante e, em média, 4 % do N mineralizado da palhada. A eficiência de utilização do nitrogênio da uréia pela soqueira de cana-de-açúcar foi em média de 17 %, não havendo diferenças entre os tratamentos, e o da palhada foi em média de 8 %. O nitrogênio da palhada foi disponibilizado para a planta no final do ciclo da cultura.An experiment was carried out to evaluate how mineralized nitrogen from cane trash and urea nitrogen applied to the soil is utilized by sugarcane ratoon. The field experiment was carried out from October 1997 to August 1998 on a Paleudalf soil in Piracicaba, State of São Paulo, Brazil

  3. Rumen fermentation characteristics, nitrogen balance and growth in lambs fed methane digester effluent

    Energy Technology Data Exchange (ETDEWEB)

    Goedeken, F.K.; Paterson, J.A.; Koeln, L.L.; Fischer, J.R.; Williams, J.E.

    1985-06-01

    A laboratory silo trial, two lamb metabolism trials and a lamb growth trial were conducted to compare the nitrogen (N) value of swine methane digester effluent (MDE) to that of urea. Using laboratory silos (four/treatment), fermentation characteristics were measured for silages containing cracked corn, ground wheat straw and MDE added at levels of 0, 4, 8 or 12% of silage dry matter (DM). Lactic acid concentration increased linearly with up to 8% MDE addition, but then decreased with 12% MDE. Butyric acid was highest with 12% MDE, indicating an undesirable fermentation. In a metabolism study, DM, organic matter and N digestibilities and N balance were similar between urea and MDE, but DM digestibility was lower for ensiled diets (52%) than diets fed fresh daily (59.4%). Mean ruminal volatile fatty acid, ruminal ammonia-N and plasma urea-N concentrations were similar between urea- and MDE-fed lambs. Plasma urea-N was higher and ruminal isovaleric acid lower in animals fed ensiled than fresh diets. In the second metabolism trial, digestibility of N was lowest for MDE and highest for soybean meal, but N balance was similar among all diets.

  4. Effect of abomasal infusion of aspartate on nitrogen balance and plasma amino acids in Holstein steers.

    Science.gov (United States)

    Wessels, R H; Titgemeyer, E C

    1998-01-01

    We investigated the effect of abomasally infused aspartate (Asp) on N balance and plasma amino acids in steers. Four ruminally cannulated Holstein steers (180 kg) housed in metabolism crates were used in an experiment designed as a 4 x 3 Youden square. Steers received continuous abomasal infusions of water or water containing 40 or 80 g Asp/d. Steers were fed twice daily a diet containing 473 g/kg corn, 463 g/kg alfalfa hay and 52 g/kg soybean meal at levels near ad libitum intake. Abomasally infused Asp had no effect on N balance. Infusion of 80 g Asp/d increased (P < 0.05) plasma concentrations of Asp, glutamate and alanine. Metabolism of Asp by gut tissues probably prevented the large change in plasma concentration of Asp that seems necessary to trigger hormonal responses. We conclude that abomasal supplementation of steers with up to 80 g/d of Asp does not enhance performance.

  5. Tribological behavior of AISI302 austenitic stainless steel modified by elevated temperature nitrogen plasma immersion ion implantation

    Institute of Scientific and Technical Information of China (English)

    JIANG Shao-qun; MA Xin-xin; SUN Yue

    2004-01-01

    AISI302 stainless steel samples were modified by elevated temperature nitrogen plasma immersion ion implantation at temperature ranging from 330 ℃ to 450 ℃. The tribological behaviors of the implanted layers of the samples were investigated. The samples were characterized by Auger electron spectroscopy (AES), glancing angle X-ray diffraction (GXRD), and nanoindentation. The results show that the implantation temperature plays an important rule on the microstructure and surface properties of the implanted layers. The thickness of the modified layer implanted at 390 ℃ is about 9 μm. It is improved about two orders compared with that of the implanted at room temperature. The surface nanohardness and the wear resistance of elevated temperature implanted layers increase significantly, and the friction coefficient decreases obviously in comparison with the unimplanted one. These data suggests that the improvement results from the formation of new phases such as ε-(Fe, Cr, Ni)2+xN, or noncrystal phase.

  6. The effect of atmosphere composition in plasma nitrogenation of Sm{sub 2}Fe{sub 17}

    Energy Technology Data Exchange (ETDEWEB)

    Ardisson, J.D. E-mail: jdr@cdtn.br; Araujo, R.C.; Macedo, W.A.A.; Persiano, A.I.C.; Gama, S

    2004-05-01

    The change on the structural and magnetic properties of the Sm{sub 2}Fe{sub 17} compound as the ratio of H{sub 2}/N{sub 2} forming the mixture of the atmosphere in a plasma chamber used to nitride this compound varied, was investigated by Moessbauer spectroscopy and X-ray diffraction. Our results show that the increase of the hydrogen concentration in the mixed H{sub 2}/N{sub 2} atmosphere reduces the formation of the nitrogen-rich phases, Sm{sub 2}Fe{sub 17}N{sub 8} and Sm{sub 2}Fe{sub 17}N{sub 11} and increases the formation of the Sm{sub 2}Fe{sub 17}N{sub 3} phase, whose maximum values are obtained for 70% H{sub 2} in the gas mixture.

  7. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Science.gov (United States)

    Seo, Hye Yeon; Kwon, Jae-Sung; Choi, Yu-Ri; Kim, Kwang-Mahn; Choi, Eun Ha; Kim, Kyoung-Nam

    2014-01-01

    The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ), elicited from one of two different gas sources (nitrogen and air), to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in cellular activity

  8. Cellular attachment and differentiation on titania nanotubes exposed to air- or nitrogen-based non-thermal atmospheric pressure plasma.

    Directory of Open Access Journals (Sweden)

    Hye Yeon Seo

    Full Text Available The surface topography and chemistry of titanium implants are important factors for successful osseointegration. However, chemical modification of an implant surface using currently available methods often results in the disruption of topographical features and the loss of beneficial effects during the shelf life of the implant. Therefore, the aim of this study was to apply the recently highlighted portable non-thermal atmospheric pressure plasma jet (NTAPPJ, elicited from one of two different gas sources (nitrogen and air, to TiO2 nanotube surfaces to further improve their osteogenic properties while preserving the topographical morphology. The surface treatment was performed before implantation to avoid age-related decay. The surface chemistry and morphology of the TiO2 nanotube surfaces before and after the NTAPPJ treatment were determined using a field-emission scanning electron microscope, a surface profiler, a contact angle goniometer, and an X-ray photoelectron spectroscope. The MC3T3-E1 cell viability, attachment and morphology were confirmed using calcein AM and ethidium homodimer-1 staining, and analysis of gene expression using rat mesenchymal stem cells was performed using a real-time reverse-transcription polymerase chain reaction. The results indicated that both portable nitrogen- and air-based NTAPPJ could be used on TiO2 nanotube surfaces easily and without topographical disruption. NTAPPJ resulted in a significant increase in the hydrophilicity of the surfaces as well as changes in the surface chemistry, which consequently increased the cell viability, attachment and differentiation compared with the control samples. The nitrogen-based NTAPPJ treatment group exhibited a higher osteogenic gene expression level than the air-based NTAPPJ treatment group due to the lower atomic percentage of carbon on the surface that resulted from treatment. It was concluded that NTAPPJ treatment of TiO2 nanotube surfaces results in an increase in

  9. Bacteria Adherence Properties of Nitrogen-Doped TiO2 Coatings by Plasma Surface Alloying Technique

    Science.gov (United States)

    Wang, Hefeng; Tang, Bin; Li, Xiuyan; Fan, Ailan

    Titanium nitride coatings on 316L stainless steel (S. S) were obtained by plasma surface alloying technique. Nitrogen-doped titanium dioxide (TiO2-xNx) was synthesized by oxidative annealing the resulted TiNx coatings in air. The reference TiO2 samples were also prepared by oxidation of sputtered Ti coatings. The as-prepared coatings were characterized by X-ray diffraction, glow discharge optical emission spectrometer (GDOES), scanning electron microscopy, X-ray hotoelectron spectroscopy and UV-Vis spectrophotometry, respectively. The bacteria adherence property of the TiO2-xNx coatings on stainless steel on the oral bacteria Streptococcus Mutans was investigated and compared with that of stainless steel by fluorescence microscopy. The mechanism of the bacteria adherence was discussed. The results show that the TiO2-xNx coatings are composed of anatase crystalline structure. SEM measurement indicates a rough surface morphology with three-dimensional homogenous protuberances after annealing treatment. Optical properties reveal an extended tailing of the absorption edge toward the visible region due to nitrogen presence. The band gap of the N-doped sample is reduced from 2.29 eV to 1.90 eV compared with the pure TiO2 one. Because of the different roughness and microstructure, the TiO2-xNx coatings inhibit the bacteria adherence.

  10. Comparative study on contribution of charge-transfer collision to excitations of iron ion between argon radio-frequency inductively-coupled plasma and nitrogen microwave induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Kozue; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2015-06-01

    This paper describes an ionization/excitation phenomenon of singly-ionized iron occurring in an Okamoto-cavity microwave induced plasma (MIP) as well as an argon radio-frequency inductively-coupled plasma (ICP), by comparing the Boltzmann distribution among iron ionic lines (Fe II) having a wide range of the excitation energy from 4.76 to 9.01 eV. It indicated in both the plasmas that plots of Fe II lines having lower excitation energies (4.76 to 5.88 eV) were fitted on each linear relationship, implying that their excitations were caused by a dominant thermal process such as collision with energetic electron. However, Fe II lines having higher excitation energies (more than 7.55 eV) had a different behavior from each other. In the ICP, Boltzmann plots of Fe II lines assigned to the higher excited levels also followed the normal Boltzmann relationship among the low-lying excited levels, even including a deviation from it in particular excited levels having an excitation energy of ca. 7.8 eV. This deviation can be attributed to a charge-transfer collision with argon ion, which results in the overpopulation of these excited levels, but the contribution is small. On the other hand, the distribution of the high-lying excited levels was non-thermal in the Okamoto-cavity MIP, which did not follow the normal Boltzmann relationship among the low-lying excited levels. A probable reason for the non-thermal characteristics in the MIP is that a charge-transfer collision with nitrogen molecule ion having many vibrational/rotational levels could work for populating the 3d{sup 6}4p (3d{sup 5}4s4p) excited levels of iron ion broadly over an energy range of 7.6–9.0 eV, while collisional excitation by energetic electron would occur insufficiently to excite these high-energy levels. - Highlights: • This paper describes the excitation mechanism of iron ion in Okamoto-cavity MIP in comparison with conventional ICP. • Boltzmann distribution is studied among iron ionic lines of

  11. Balanço do nitrogênio da uréia (15N no sistema solo-planta na implantação da semeadura direta na cultura do milho Balance of nitrogen from urea (15N in the soil-plant system at the establishment of no-till in maize

    Directory of Open Access Journals (Sweden)

    Glauber José de Castro Gava

    2006-01-01

    and partitioning of the phytomass, in the accumulation of total nitrogen and nitrogen in the plant derived from the fertilizer, by using the 15N side-dressing fertilization at the establishment of no-till management. The experiment was carried out in a Nitosol at Água Sumida Farm located near Barra Bonita, State of São Paulo. The experiment was arranged in completely randomized block design, with 4 replicates. The following treatments were studied: conventional tillage system (one ploughing and two harrowings and no-tilllage, both fertilized with urea (15N applied at the rate of 100 kg ha-1 nitrogen. All treatments were subjected to sowing fertilization, by applying 25 kg ha-1 N as urea, 80 kg ha-1 P2O5 as simple superphosphate and 60 kg ha-1 K2O as potassium chloride. At the end of the phenological cycle, the following comparisons among the treatments were performed: crop yeld; nitrogen accumulation in the aerial and underground parts; use of nitrogen from urea (15N and residual nitrogen in the soil. The modifications of the soil caused by implantation of no-till neither restricted the availability of nitrogen to maize plants, nor the production of dry matter. The use efficiency of nitrogen fertilization of maize plants and the recovery of the soil nitrogen fertilizer were around 45% and 30%, respectively, for the urea-N side-dressing fertilization in both conventional and no-till systems. Nitrogen applied as side-dressing fertilization, and not recovered from urea (NNR averaged 25%, independently of the sowing system.

  12. Hydrophobic recovery of repeatedly plasma-treated silicone rubber .2. A comparison of the hydrophobic recovery in air, water, or liquid nitrogen

    NARCIS (Netherlands)

    Everaert, EP; VanderMei, HC; Busscher, HJ

    1996-01-01

    Surfaces of medical grade silicone rubber (Q7-4750, Dow Coming) were modified by repeated (six times) RF plasma treatments using various discharge gases: oxygen, argon, carbon dioxide, and ammonia. The treated samples were stored for a period of 3 months in ambient air, water, or liquid nitrogen. Su

  13. Comparison of plasma generated nitrogen fertilizer to conventional fertilizers ammonium nitrate and sodium nitrate for pre-emergent and seedling growth

    Science.gov (United States)

    Andhavarapu, A.; King, W.; Lindsay, A.; Byrns, B.; Knappe, D.; Fonteno, W.; Shannon, S.

    2014-10-01

    Plasma source generated nitrogen fertilizer is compared to conventional nitrogen fertilizers in water for plant growth. Root, shoot sizes, and weights are used to examine differences between plant treatment groups. With a simple coaxial structure creating a large-volume atmospheric glow discharge, a 162 MHz generator drives the air plasma. The VHF plasma source emits a steady state glow; the high drive frequency is believed to inhibit the glow-to-arc transition for non-thermal discharge generation. To create the plasma activated water (PAW) solutions used for plant treatment, the discharge is held over distilled water until a 100 ppm nitrate aqueous concentration is achieved. The discharge is used to incorporate nitrogen species into aqueous solution, which is used to fertilize radishes, marigolds, and tomatoes. In a four week experiment, these plants are watered with four different solutions: tap water, dissolved ammonium nitrate DI water, dissolved sodium nitrate DI water, and PAW. Ammonium nitrate solution has the same amount of total nitrogen as PAW; sodium nitrate solution has the same amount of nitrate as PAW. T-tests are used to determine statistical significance in plant group growth differences. PAW fertilization chemical mechanisms are presented.

  14. Optical Tweezers Analysis of Double-Stranded DNA Denaturation in the Presence of Urea

    Science.gov (United States)

    Zhu, Chunli; Li, Jing

    2016-09-01

    Urea is a kind of denaturant prone to form hydrogen bonds with the electronegative centers of the nitrogenous bases, threatening the stability of hydrogen bonds between DNA base pairs. In this paper, the stability and stiffness of DNA double helix influenced by urea are investigated at single-molecule level using optical tweezers. Experimental results show that DNA's double helix stability and stiffness both decrease with increasing urea concentration. In addition, the re-forming of ruptured hydrogen bonds between the base pairs is blocked by urea as the tension on DNA is released.

  15. An evaluation of twelve nested models of transperitoneal transport of urea

    DEFF Research Database (Denmark)

    Graff, J; Fugleberg, S; Joffe, P;

    1995-01-01

    Models of transperitoneal urea transport are generally based on the one-compartment assumption, i.e. that the plasma water urea concentration in the peritoneal capillary bed is equal to the plasma water urea concentration in the peripheral veins. The aim of this study was to investigate...... the mechanism(s) of transperitoneal urea transport and to test the one-compartment assumption for urea. A total of 12 nested models were formulated and validated on the basis of experimental results obtained from 23 non-diabetic patients undergoing peritoneal dialysis. The validation procedure demonstrated...... that transperitoneal transport of urea probably involves diffusion, non-lymphatic convection and lymphatic convection. It was furthermore demonstrated that the inclusion of lymphatic convection changes the mass transfer area coefficient considerably. Finally, no deviation from the one-compartment assumption...

  16. Effect of feeding garlic leaf on microbial nitrogen supply, kinetics of plasma phenylalanine, tyrosine and protein synthesis in sheep.

    Science.gov (United States)

    Kamruzzaman, Md; Liang, Xi; Sekiguchi, Natsumi; Sano, Hiroaki

    2014-05-01

    The objective of the present study was to assess the feeding effects of garlic leaf on microbial N supply (MNS), turnover rates of plasma phenylalanine (PheTR) and tyrosine (TyrTR) and whole body protein synthesis (WBPS) in sheep. The sheep were fed either mixed hay (Hay-diet, as control) or hay plus garlic leaf diet (GL-diet, at a ratio of 9:1) in a crossover design each for a 21 day period. The isotope dilution method using [(2) H5 ]Phe and [(2) H2 ]Tyr was performed on the 21st day of each dietary treatment. Nitrogen intake remained similar between the diets and N absorption and N digestibility were higher (P<0.05) in the GL-diet than Hay-diet. Total purine derivatives excretion and MNS were greater (P<0.05) in the GL-diet than the Hay-diet. Plasma PheTR tended to be higher (P=0.06) during GL feeding and TyrTR did not differ between the diets. Further, WBPS tended to be greater (P=0.05) for the GL-diet compared with the Hay-diet. Hence, the present results suggest that garlic leaf may have positive effects on N metabolism by influencing MNS in sheep and could be used as a potential ruminant feed in the future.

  17. Nitrogen fixation and growth response of Alnus Rubra following fertiliztion with urea or biosolids Fixação de nitrogênio e crescimento de Alnus Rubra fertilização com uréia ou biosólidos

    Directory of Open Access Journals (Sweden)

    Linda S. Gaulke

    2006-08-01

    Full Text Available Nitrogen fertilization of forests using biosolids offers a potentially environmentally friendly means to accelerate tree growth. This field study was designed to analyze the effects of nitrogen fertilization on the symbiotic, nitrogen (N-fixing relationship between Alnus rubra Bong. (red alder and Frankia. Anaerobically digested, class B biosolids and synthetic urea (46% N were applied at rates of 140, 280 and 560 kg ha-1 available N to a well-drained, sandy, glacial outwash soil in the Indianola series (mixed, mesic Dystric Xeropsamments. Plots were planted with A. rubra seedlings. At the end of each of two growing seasons trees were harvested and analyzed for the rate of N fixation (as acetylene reduction activity, biomass and foliar N. At year 1, there was no N fixation for trees grown with urea amendments, but control (17 µmol C2H4 g-1 hr-1 and biosolids (26-45 µmol C2H4 g-1 hr-1 trees were fixing N. At the end of year 2, all trees in all treatments were fixing N (7 µmol C2H4 g-1 hr-1, 4-16 µmol C2H4 g-1 hr-1, and 20-29 µmol C2H4 g-1 hr-1 for control, urea and biosolids respectively. Trees grown with biosolids amendments were larger overall (year 1 shoot biomass 10 g, 5 g, and 23 g for control, urea, and biosolids respectively, year 2 shoot biomass 50 g, 51 g, and 190 g for control, urea, and biosolids respectively with higher concentrations of foliar N for both years of the study (year 1 foliar N 26 g kg-1, 27 g kg-1, and 40 g kg-1 for control, urea, and biosolids respectively, year 2 foliar N 17 g kg-1, 19 g kg-1, and 23 g kg-1 for control, urea, and biosolids respectively. Trees grown with urea amendments appeared to use the urea N over Frankia supplied N, whereas the biosolids trees appeared to be able to use both N in biosolids and N from Frankia. The results from this study indicated that the greater growth of A. rubra may have been responsible for the observed higher N demand. Biosolids may have supplied other nutrients to the

  18. Rumen metabolism of swamp buffaloes fed rice straw supplemented with cassava hay and urea.

    Science.gov (United States)

    Ampapon, Thiwakorn; Wanapat, Metha; Kang, Sungchhang

    2016-04-01

    The objectives of this experiment were to investigate effects of cassava hay (CH) and urea (U) supplementation on feed intake, digestibility, rumen fermentation, and microbial protein synthesis of swamp buffaloes fed on rice straw. Four rumen-fistulated swamp buffaloes, 365 ± 15.0 kg, were randomly assigned according to a 4 × 4 Latin square design to receive four dietary treatments: T1 = CH 400 g/head/day + U 0 g/head/day, T2 = CH + U 30 g/head/day, T3 = CH + U 60 g/head/day, and T4 = CH + U 90 g/head/day, respectively. Results revealed that feed intake was not affected while nutrient digestibilities were increased (P urea supplementation, whereas ammonia nitrogen (NH3-N) and blood urea nitrogen were increased with urea supplement (P urea supplement (P urea supplement, while bacterial population particularly those of proteolytic, cellulolytic, and amylolytic bacteria and efficiency of microbial nitrogen synthesis were linearly increased (P urea and cassava hay for buffaloes fed rice straw improved rumen ecology and increased fermentation end products and microbial protein synthesis while reducing protozoal populations and methane production. Urea supplements of 60-90 g/head/day when fed with cassava hay are recommended for swamp buffaloes consuming rice straw.

  19. Dynamic outgassing of deuterium, helium and nitrogen from plasma-facing materials under DEMO relevant conditions

    Science.gov (United States)

    Möller, S.; Matveev, D.; Martynova, Y.; Unterberg, B.; Rasinski, M.; Wegener, T.; Kreter, A.; Linsmeier, Ch.

    2017-01-01

    In confined plasma magnetic fusion devices significant amounts of the hydrogen isotopes used for the fusion reaction can be stored in the plasma-facing materials by implantation. The desorption of this retained hydrogen was seen to follow a t α law with α  ≈  -0.7 in tokamaks. For a pulsed fusion reactor this outgassing can define the inter-pulse waiting time. This work presents new experimental data on the dynamic outgassing in ITER grade tungsten exposed under the well-defined conditions of PSI-2 to pure and mixed D2 plasmas. A peak ion flux of 1022 D+ m-2 s is applied for up to 6 h at sample temperatures of up to 900 K. Pure D2 and mixed D2  +  He, D2  +  N2 and D2  +  He  +  N2 plasmas are applied to the sample at 68 V bias. The D2, He, N outgassing at 293 K and 580 k are observed via in-vacuo quadrupole mass spectrometry covering the range of 40 s-200 000 s after exposure. The outgassing decay follows a single power law with exponents α  =  -0.7  to  -1.1 at 293 K, but at 580 K a drop from α  =  -0.25 to  -2.35 is found. For DEMO a pump-down time to 0.5 mPa in the order of 1-5 h can be expected. The outgassing is in all cases dominated by D2.

  20. Chemical bonding structural analysis of nitrogen-doped ultrananocrystalline diamond/hydrogenated amorphous carbon composite films prepared by coaxial arc plasma deposition

    Science.gov (United States)

    Gima, Hiroki; Zkria, Abdelrahman; Katamune, Yūki; Ohtani, Ryota; Koizumi, Satoshi; Yoshitake, Tsuyoshi

    2017-01-01

    Nitrogen-doped ultra-nanocrystalline diamond/hydrogenated amorphous carbon composite films prepared in hydrogen and nitrogen mixed-gas atmospheres by coaxial arc plasma deposition with graphite targets were studied electrically and chemical-bonding-structurally. The electrical conductivity was increased by nitrogen doping, accompanied by the production of n-type conduction. From X-ray photoemission, near-edge X-ray absorption fine-structure, hydrogen forward-scattering, and Fourier transform infrared spectral results, it is expected that hydrogen atoms that terminate diamond grain boundaries will be partially replaced by nitrogen atoms and, consequently, π C–N and C=N bonds that easily generate free electrons will be formed at grain boundaries.

  1. 妊娠期糖尿病并妊娠期高血压疾病孕妇孕中期血清尿素氮肌酐和尿酸水平的变化%Changes of serum urea nitrogen, creatinine and uric acid levels in pregnant women with gestational diabetes mellitus combined with hypertensive disorder complicating pregnancy

    Institute of Scientific and Technical Information of China (English)

    杨坤; 廖有乔; 柯丽娜; 彭华

    2011-01-01

    Objective: To analyze the changes of serum urea nitrogen, creatinine and uric acid levels in pregnant women with ges-tational diabetes mellitus (GDM) combined with hypertensive disorder complicating pregnancy (HDCP) , in order to find abnormal indexes early and take preventive measures early. Methods: The changes of serum urea nitrogen, creatinine and uric acid levels during the second trimester of pregnancy in 112 pregnant women with GDM ( A group) , 38 pregnant women with GDM combined with HDCP (B group) and 32 pregnant women with normal 75 g oral glucose tolerance test (OGTT) (NGT group) were observed and compared. Results; Compared with NGT group and A group, FPG, 2 -hour PG, HbAlC, serum urea nitrogen, creatinine and uric acid in B group increased significantly (P0.05) . Conclusion; When GDM can not be controlled well during pregnancy, and serum urea nitrogen, creatinine and uric acid levels are higher than those of normal pregnant women, preventive measures should be taken to avoid the occurrence of HDCP.%目的:分析妊娠期糖尿病(GDM)并妊娠高血压疾病孕妇孕中期血清尿素氮、肌酐和尿酸水平的变化,便于发现早期异常指标,以利早期防范.方法:观察比较112例GDM(A组)、38例GDM并妊娠高血压疾病(B组)和32例75g葡萄糖耐量试验(0GTT)正常的孕妇(NGT组)孕中期血清尿素氮、肌酐和尿酸水平的变化.结果:与NGT及A组相比,B组FPG、2 h PG、HbAlC、血清尿素氮、肌酐和尿酸增高,差异有统计学意义(P<0.01);A组与NGT组相比,FPG、2hPG、HbAlC增高,差异有统计学意义(P<0.01),血清尿素氮、肌酐和尿酸差异无统计学意义(P>0.05).结论:GDM孕期血糖控制不良时,如发现血清尿素氮、肌酐和尿酸浓度值在正常范围上限或明显高于正常孕妇,就应高度警惕,及早做好防范措施,避免将来妊娠高血压疾病的发生.

  2. Generation of reactive oxygen and nitrogen species and its effects on DNA damage in lung cancer cells exposed to atmospheric pressure helium/oxygen plasma jets

    Science.gov (United States)

    Chung, Tae Hun; Joh, Hea Min; Kim, Sun Ja; Choi, Ji Ye; Kang, Tae-Hong

    2016-09-01

    We investigated the effects of the operating parameters on the generation of reactive oxygen and nitrogen species (RONS) in the gas and liquid phases exposed to atmospheric pressure a pulsed-dc helium plasma jets. The densities of reactive species including OH radicals were obtained at the plasma-liquid surface and inside the plasma-treated liquids using ultraviolet absorption spectroscopy and chemical probe method. And the nitrite concentration was detected by Griess assay. The data are very suggestive that there is a strong correlation among the production of RONS in the plasmas and liquids. Exposure of plasma to cancer cells increases the cellular levels of RONS, which has been linked to apoptosis and the damage of cellular proteins, and may also indirectly cause structural damage to DNA. To identify the correlation between the production of RONS in cells and plasmas, various assay analyses were performed on plasma treated human lung cancer cells (A549) cells. In addition, the effect of additive oxygen gas on the plasma-induced oxidative stress in cancer cells was investigated. It was observed that DNA damage was significantly increased with helium/oxygen plasma compared to with pure helium plasma.

  3. Discovery of enantioselectivity of urea inhibitors of soluble epoxide hydrolase.

    Science.gov (United States)

    Manickam, Manoj; Pillaiyar, Thanigaimalai; Boggu, PullaReddy; Venkateswararao, Eeda; Jalani, Hitesh B; Kim, Nam-Doo; Lee, Seul Ki; Jeon, Jang Su; Kim, Sang Kyum; Jung, Sang-Hun

    2016-07-19

    Soluble epoxide hydrolase (sEH) hydrolyzes epoxyeicosatrienoic acids (EETs) in the metabolic pathway of arachidonic acid and has been considered as an important therapeutic target for chronic diseases such as hypertension, diabetes and inflammation. Although many urea derivatives are known as sEH inhibitors, the enantioselectivity of the inhibitors is not highlighted in spite of the stereoselective hydrolysis of EETs by sEH. In an effort to explore the importance of enantioselectivity in the urea scaffold, a series of enantiomers with the stereocenter adjacent to the urea nitrogen atom were prepared. The selectivity of enantiomers of 1-(α-alkyl-α-phenylmethyl)-3-(3-phenylpropyl)ureas showed wide range differences up to 125 fold with the low IC50 value up to 13 nM. The S-configuration with planar phenyl and small alkyl groups at α-position is crucial for the activity and selectivity. However, restriction of the free rotation of two α-groups with indan-1-yl or 1,2,3,4-tetrahydronaphthalen-1-yl moiety abolishes the selectivity between the enantiomers, despite the increase in activity up to 13 nM. The hydrophilic group like sulfonamido group at para position of 3-phenylpropyl motif of 1-(α-alkyl-α-phenylmethyl-3-(3-phenylpropyl)urea improves the activity as well as enantiomeric selectivity. All these ureas are proved to be specific inhibitor of sEH without inhibition against mEH.

  4. Surface modification of biphasic calcium phosphate scaffolds by non-thermal atmospheric pressure nitrogen and air plasma treatment for improving osteoblast attachment and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yu-Ri [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Kwon, Jae-Sung [Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Song, Doo-Hoon [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Choi, Eun Ha [Plasma Bioscience Research Center Kwangwoon University, Seoul 139-701, 447-1 Wokgye-Dong, Nowon-Gu, Seoul (Korea, Republic of); Lee, Yong-Keun [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Kyoung-Nam [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of); Kim, Kwang-Mahn, E-mail: kmkim@yuhs.ac [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Research Center for Orofacial Hard Tissue Regeneration, College of Dentistry, Yonsei University, Seoul 120-752 (Korea, Republic of)

    2013-11-29

    Surface modifications induced by non-thermal plasma have been used extensively in biomedical applications. The attachment and proliferation of osteoblast cells are important in bone tissue engineering using scaffolds. Hence the effect of non-thermal plasma on hydroxyapatite/β-tri-calcium phosphate (HA/β-TCP) scaffolds in terms of improving osteoblast attachment and proliferation was investigated. Experimental groups were treated with non-thermal plasma for 10 min and 20 min and a control group was not treated with non-thermal plasma. For surface chemistry analysis, X-ray photoelectron spectroscopy (XPS) analysis was carried out. The hydrophilicity was determined from contact angle measurement on the surface. Atomic force microscopy analysis (AFM) was used to test the change in surface roughness and cell attachment and proliferation were evaluated using MC3T3-E1 osteoblast cells. XPS spectra revealed a decreased amount of carbon on the surface of the plasma-treated sample. The contact angle was also decreased following plasma treatment, indicating improved hydrophilicity of plasma-treated surfaces compared to the untreated disc. A significant increase in MC3T3E-1 cell attachment and proliferation was noted on plasma-treated samples as compared to untreated specimens. The results suggest that non-thermal atmospheric pressure nitrogen and air plasma treatments provide beneficial surface characteristics on HA/β-TCP scaffolds. - Highlights: ► Non-thermal plasma increased OH- and decreased C on biphasic scaffold. ► Non-thermal plasma had no effect on surface roughness. ► Non-thermal plasma resulted in hydrophilic surface. ► Non-thermal plasma resulted in better cell attachment and proliferation. ► Non-thermal plasma treatment on biphasic scaffold is useful for tissue engineering.

  5. 硫包膜控释尿素和树脂包膜控释尿素混施对番茄生长及氮代谢酶活性的影响%Effects of Mixed Application of Sulfur-coated and Resin-coated Controlled Release Urea Fertilizer on Growth and Nitrogen Metabolism-related Enzyme Activities of Tomato

    Institute of Scientific and Technical Information of China (English)

    丁坤; 王秀峰; 杨凤娟; 张民; 魏珉; 史庆华

    2012-01-01

    In the condition of pot planting in greenhouse, the mixed application of sulfur - coated (SCU, controlled release period as four months) and resin — coated ( RCU, controlled release period as six months) controlled release urea fertilizer with each providing 50% nitrogen respecetively was studied, and its effects under the same nitrogen, 30% and 50% nitrogen reduced level on the growth, photosynthetic rate and nitrogen metabolism - related enzyme activities of tomato were compared with urea. The results showed that in all sampling periods, the content of Chla, Chlb and Car, Pn, as well as the activity of NR, GS and GOGAT decreased with the reduction of nitrogen amount, following with the decrease of tomato plant height and stem di-ameter. Under the same nitrogen level, the activities of NR, GS and GOGAT of SCU and RCU treatment were lower than those of urea treatment after planted for 30 days, while there were no significant differences in the content of Chla,Chlb,Car and Pn. After planted for 60 and 90 days, all the indexes of SCU and RCU treatment were higher than those of urea treatment. Besides, after planted for 60 days and under 30% nitrogen reduced level, the contents of Chla, Chlb and Car, Pn, as well as the activities of NR, GS and GOGAT of SCU and RCU treatments had no significant difference with those of 100% urea treatment, and the tomato plant height and stem grew well. In summary, the nutrient release rules of SCU and RCU controlled - release fertilizer was consistent with tomato requirement rules in the late of tomato growth, which promoted the synthesis of photosynthetic pigments and nitrogen metabolism -related enzyme activities, delayed leaf senescence and had much help for the formation of tomato production.%在日光温室盆栽条件下,研究了尿素(U)、硫包膜控释尿素(SCU,控释期4个月)和树脂包膜控释尿素(RCU,控释期6个月)混施(各提供50%氮素)在同等氮素及减氮30%、50%条

  6. High and Low Affinity Urea Root Uptake: Involvement of NIP5;1.

    Science.gov (United States)

    Yang, Huayiu; Menz, Jochen; Häussermann, Iris; Benz, Martin; Fujiwara, Toru; Ludewig, Uwe

    2015-08-01

    Urea is the most widespread nitrogen (N) fertilizer worldwide and is rapidly degraded in soil to ammonium by urease. Ammonium is either taken up by plant roots or is further processed to nitrate by soil microorganisms. However, urea can be taken up by roots and is further degraded to ammonium by plant urease for assimilation. When urea is supplied under sterile conditions, it acts as a poor N source for seedlings or adult Arabidopsis thaliana plants. Here, the gene expression of young seedlings exposed to urea and ammonium nitrate nutrition was compared. Several primary metabolism and transport genes, including those for nitrate and urea, were differentially expressed in seedlings. However, urease and most major intrinsic proteins were not differentially expressed, with the exception of NIP6;1, a urea-permeable channel, which was repressed. Furthermore, little overlap with the gene expression with ammonium as the sole N source was observed, confirming that pure urea nutrition is not associated with the ammonium toxicity syndrome in seedlings. The direct root uptake of urea was increased under boron deficiency, in both the high and low affinity range. This activity was entirely mediated by the NIP5;1 channel, which was confirmed to transport urea when expressed in oocytes. The uptake of urea in the high and low affinity range was also determined for maize and wheat roots. The urea uptake by maize roots was only about half that of wheat, but was not stimulated by boron deficiency or N deficiency in either species. This analysis identifies novel components of the urea uptake systems in plants, which may become agronomically relevant to urea uptake and utilization, as stabilized urea fertilizers become increasingly popular. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Modification of the Steel Surface Treated by a Volume Discharge Plasma in Nitrogen at Atmospheric Pressure

    Science.gov (United States)

    Erofeev, M. V.; Shulepov, M. A.; Ivanov, Yu. F.; Oskomov, K. V.; Tarasenko, V. F.

    2016-03-01

    Effect of volume discharge plasma initiated by an avalanche electron beam on the composition, structure, and properties of the surface steel layer is investigated. Voltage pulses with incident wave amplitude up to 30 kV, full width at half maximum of about 4 ns, and wave front of about 2.5 ns were applied to the gap with an inhomogeneous electric field. Changes indicating the hardening effect of the volume discharge initiated by an avalanche electron beam are revealed in St3-grade steel specimens treated by the discharge of this type.

  8. Electrochemical process for the preparation of nitrogen fertilizers

    Science.gov (United States)

    Aulich, Ted R.; Olson, Edwin S.; Jiang, Junhua

    2013-03-19

    The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be solid.

  9. Biodegraded and Polyurethane Drape-formed Urea Fertilizer

    Institute of Scientific and Technical Information of China (English)

    WANG Yong; LI Jian; CHEN Xiaoyao

    2005-01-01

    Natural water absorbent konjac flour participates in synthesizing biodegraded and polyurethane foamed drape, which is used to release urea slowly.The experimental results indicate that the slowly-releasing velocity of urea nitrogen and the degrading velocity of the drape can be controlled by regulating the thicknesses of drapes, the amount of konjac flour and the water content. In addition, the biodegradability of the drape was investigated by burying the specimens in earth afterwards,and results show this drape can be degraded naturally.

  10. Surface modification by nitrogen plasma immersion ion implantation into new steel 460Li–21Cr in a capacitively coupled radio frequency discharge

    Energy Technology Data Exchange (ETDEWEB)

    Bhuyan, H., E-mail: hbhuyan@fis.puc.cl [Institute of Physics, Pontificia Universidad Católica de Chile, Santiago (Chile); Mändl, S. [Leibniz-Institut für Oberflächenmodifizierung, Leipzig (Germany); Bora, B.; Favre, M.; Wyndham, E.; Maze, J.R. [Institute of Physics, Pontificia Universidad Católica de Chile, Santiago (Chile); Walczak, M. [Department of Mechanical and Metallurgical Engineering, Pontificia Universidad Católica de Chile, Santiago (Chile); Manova, D. [Leibniz-Institut für Oberflächenmodifizierung, Leipzig (Germany)

    2014-10-15

    Highlights: • Nitriding of a novel steel has been done in a RF plasma by PIII technique. • Improved hardness and wear behavior have been observed. • Hardness was improved by a factor 4 and the wear by 2 orders of magnitude. • Fast, anomalous diffusion, similar to nitrogen in expanded austenite is observed. - Abstract: A novel steel 460Li–21Cr belonging to a new generation of superferritic grade steel has been implanted with nitrogen in a low power 13.56 MHz radio frequency plasma by the plasma immersion ion implantation (PIII) technique in order to study its physical and chemical properties under different experimental conditions. We observed improved hardness and wear behavior of 460Li–21Cr steel with a layer thickness between 1.5 and 4.0 μm after 60 min implantation in the temperature range from 350 to 550 °C. The modified surface layer containing nitrogen does not show CrN in X-ray diffraction (XRD). Compared to untreated substrates, the hardness can be increased by a factor of 4, depending on the experimental conditions, and the wear behavior was also improved by two orders of magnitude. The results are very similar to those for austenitic stainless steel with a similar pronounced increase in wear resistance and plateau-like nitrogen depth profiles.

  11. A study on the indirect urea dosing method in the Selective Catalytic Reduction system

    Science.gov (United States)

    Brzeżański, M.; Sala, R.

    2016-09-01

    This article presents the results of studies on concept solution of dosing urea in a gas phase in a selective catalytic reduction system. The idea of the concept was to heat-up and evaporate the water urea solution before introducing it into the exhaust gas stream. The aim was to enhance the processes of urea converting into ammonia, what is the target reductant for nitrogen oxides treatment. The study was conducted on a medium-duty Euro 5 diesel engine with exhaust line consisting of DOC catalyst, DPF filter and an SCR system with a changeable setup allowing to dose the urea in liquid phase (regular solution) and to dose it in a gas phase (concept solution). The main criteria was to assess the effect of physical state of urea dosed on the NOx conversion ratio in the SCR catalyst. In order to compare both urea dosing methods a special test procedure was developed which consisted of six test steps covering a wide temperature range of exhaust gas generated at steady state engine operation condition. Tests were conducted for different urea dosing quantities defined by the a equivalence ratio. Based on the obtained results, a remarkable improvement in NOx reduction was found for gas urea application in comparison to the standard liquid urea dosing. Measured results indicate a high potential to increase an efficiency of the SCR catalyst by using a gas phase urea and provide the basis for further scientific research on this type of concept.

  12. Effect of nickel nutrition on yield, urea accumulation and urease enzyme activity of lettuce

    Directory of Open Access Journals (Sweden)

    M. Afyuni

    2011-04-01

    Full Text Available Although nickel (Ni is known as an essential element for higher plants, the biological effects of this nutrient on growth, yield, and N metabolism of some plants, particularly leafy vegetables, is still unknown. Therefore, this study was carried out to investigate the effects of Ni and urea nutrition on the growth and yield of lettuce (Lactuca sativa L. cv. Baker and urea accumulation in plant tissues. In this study, nitrogen was supplied from the source of urea or ammonium nitrate at three levels (5, 10 and 20 mM and Ni was supplied in the form of NiCl2 at two levels (0 and 0.04 µM. The plants were harvested 6 weeks after transplanting and the fresh weight of shoots and roots were determined. The shoots urea concentration and activity of urease enzyme in the leaves were also measured. The results indicated that shoots fresh weight of the urea-fed plants increased with increasing urea concentration in the nutrient solution. Addition of Ni to the nutrient solution significantly promoted the root and shoots fresh weight of urea-fed plants, regardless of N level. Ni nutrition significantly increased the urease activity in the lettuce leaves and as a result, reduced urea accumulation in the shoots and toxicity effects of urea. Therefore, it seems that urea in combination with Ni can successfully be used in production of lettuce in soilless culture systems.

  13. Atmospheric Pressure Plasma CVD of Amorphous Hydrogenated Silicon Carbonitride (a-SiCN:H) Films Using Triethylsilane and Nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan Guruvenket; Steven Andrie; Mark Simon; Kyle W. Johnson; Robert A. Sailer

    2011-10-04

    Amorphous hydrogenated silicon carbonitride (a-SiCN:H) thin films are synthesized by atmospheric pressure plasma enhanced chemical vapor (AP-PECVD) deposition using the Surfx Atomflow{trademark} 250D APPJ source with triethylsilane (HSiEt{sub 3}, TES) and nitrogen as the precursor and the reactive gases, respectively. The effect of the substrate temperature (T{sub s}) on the growth characteristics and the properties of a-SiCN:H films was evaluated. The properties of the films were investigated via scanning electron microscopy (SEM), atomic force microscopy (AFM) for surface morphological analyses, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) for chemical and compositional analyses; spectroscopic ellipsometry for optical properties and thickness determination and nanoindentation to determine the mechanical properties of the a-SiCN:H films. Films deposited at low T{sub s} depict organic like features, while the films deposited at high T{sub s} depict ceramic like features. FTIR and XPS studies reveal that an increases in T{sub s} helps in the elimination of organic moieties and incorporation of nitrogen in the film. Films deposited at T{sub s} of 425 C have an index of refraction (n) of 1.84 and hardness (H) of 14.8 GPa. A decrease in the deposition rate between T{sub s} of 25 and 250 C and increase in deposition rate between T{sub s} of 250 and 425 C indicate that the growth of a-SiCN:H films at lower T{sub s} are surface reaction controlled, while at high temperatures film growth is mass-transport controlled. Based on the experimental results, a potential route for film growth is proposed.

  14. Parcelamento e largura da faixa de aplicação da uréia na recuperação do nitrogênio pela planta de milho Splitting and width of strip urea applications and the recovery of nitrogen by maize plants

    Directory of Open Access Journals (Sweden)

    Roberto Lyra Villas Bôas

    1999-01-01

    Full Text Available Com o objetivo de estudar o parcelamento e a largura da faixa de aplicação como meios para aumentar a recuperação pelo milho do nitrogênio da uréia aplicada em superfície, foi conduzido no ano agrícola 93/94, em um Latossolo Vermelho Escuro, em condições de campo, um experimento delineado em blocos ao acaso, com cinco repetições. Sete tratamentos foram utilizados: testemunha (sem N em cobertura; aplicação de N parcelada (50 kg ha-1 de N aos 38 dias após semeadura - d.a.s e 50 kg ha-1 de N aos 60 d.a.s. para faixas de 10, 20 e 40 cm; aplicação de N (100 kg ha-1 de N aos 38 d.a.s. para faixas de 10 e 40 cm e, aplicação de N parcelada (50 kg de N/ha aos 38 d.a.s. e 50 kg ha-1 de N aos 60 d.a.s. para faixa de 20 cm de largura, neste caso, uréia granulada. A aplicação de uréia parcelada em cobertura, em faixas de 10, 20 e 40 cm de largura, não afetaram a massa de matéria seca, o conteúdo, a quantidade e a recuperação do N pela planta de milho. A recuperação de N pela planta de milho foi maior para a aplicação de 220 kg ha-1 de uréia em uma única aplicação em faixas de 10cm de largura em relação a de 40 cm. O parcelamento da uréia aumentou os valores de massa seca, conteúdo, quantidade e recuperação do N na planta de milho em relação a aplicação em uma única vez.In order to evaluate the nitrogen recovery by maize, following a surface application of urea, a trial was carried out during 1993/94 under field conditions, on a dark red latosol (oxisol. A randomized complete block statistical design was used, with seven treatments and five replications. The seven treatments were: control (no N; three split N applications (50 kg N ha-1 urea at 38 and 60 days after sowing using 10, 20 or 40 cm width strips; two single N applications (100 kg N ha-1 urea at 38 days after sowing using 10 or 40 cm width strips; and split N applications (50 kg N ha-1 urea at 38 and 60 days after sowing using a 20 cm width strip

  15. Consistent multi-internal-temperature models for vibrational and electronic nonequilibrium in hypersonic nitrogen plasma flows

    Energy Technology Data Exchange (ETDEWEB)

    Guy, Aurélien, E-mail: aurelien.guy@onera.fr; Bourdon, Anne, E-mail: anne.bourdon@lpp.polytechnique.fr; Perrin, Marie-Yvonne, E-mail: marie-yvonne.perrin@ecp.fr [CNRS, UPR 288, Laboratoire d' Énergétique Moléculaire et Macroscopique, Combustion (EM2C), Grande Voie des Vignes, 92295 Châtenay-Malabry (France); Ecole Centrale Paris, Grande Voie des Vignes, 92295 Châtenay-Malabry (France)

    2015-04-15

    In this work, a state-to-state vibrational and electronic collisional model is developed to investigate nonequilibrium phenomena behind a shock wave in an ionized nitrogen flow. In the ionization dynamics behind the shock wave, the electron energy budget is of key importance and it is found that the main depletion term corresponds to the electronic excitation of N atoms, and conversely the major creation terms are the electron-vibration term at the beginning, then replaced by the electron ions elastic exchange term. Based on these results, a macroscopic multi-internal-temperature model for the vibration of N{sub 2} and the electronic levels of N atoms is derived with several groups of vibrational levels of N{sub 2} and electronic levels of N with their own internal temperatures to model the shape of the vibrational distribution of N{sub 2} and of the electronic excitation of N, respectively. In this model, energy and chemistry source terms are calculated self-consistently from the rate coefficients of the state-to-state database. For the shock wave condition studied, a good agreement is observed on the ionization dynamics as well as on the atomic bound-bound radiation between the state-to-state model and the macroscopic multi-internal temperature model with only one group of vibrational levels of N{sub 2} and two groups of electronic levels of N.

  16. Investigations of nitrogen oxide plasmas: Fundamental chemistry and surface reactivity and monitoring student perceptions in a general chemistry recitation

    Science.gov (United States)

    Blechle, Joshua M.

    Part I of this dissertation focuses on investigations of nitrogen oxide plasma systems. With increasing concerns over the environmental presence of NxOy species, there is growing interest in utilizing plasma-assisted conversion techniques. Advances, however, have been limited because of the lack of knowledge regarding the fundamental chemistry of these plasma systems. Understanding the kinetics and thermodynamics of processes in these systems is vital to realizing their potential in a range of applications. Unraveling the complex chemical nature of these systems, however, presents numerous challenges. As such, this work serves as a foundational step in the diagnostics and assessment of these NxOy plasmas. The partitioning of energy within the plasma system is essential to unraveling these complications as it provides insight into both gas and surface reactivity. To obtain this information, techniques such as optical emission spectroscopy (OES), broadband absorption spectroscopy (BAS), and laser induced fluorescence (LIF) were utilized to determine species energetics (vibrational, rotational, translational temperatures). These temperature data provide mechanistic insight and establish the relationships between system parameters and energetic outcomes. Additionally, these data are also correlated to surface reactivity data collected with the Imaging of Radicals Interacting with Surfaces (IRIS) technique. IRIS data demonstrate the relationship between internal temperatures of radicals and their observed surface scatter coefficients (S), the latter of which is directly related to surface reactivity (R) [R = 1-S]. Furthermore, time-resolved (TR) spectroscopic techniques, specifically TR-OES, revealed kinetic trends in NO and N2 formation from a range of precursors (NO, N2O, N2/O2). By examining the rate constants associated with the generation and destruction of various plasma species we can investigate possible mechanistic implications. All told, such data provides

  17. Characteristics of Wheat-Maize Yield and Soil Organic Carbon/Nitrogen Mineralization in Cinnamon Soil with Application of Different Activation Humic Acid-Urea%不同活化处理腐植酸-尿素对褐土小麦-玉米产量及有机碳氮矿化的影响

    Institute of Scientific and Technical Information of China (English)

    刘艳丽; 丁方军; 谷端银; 吴钦泉; 张民; 李成亮

    2015-01-01

    efficiency of humic acid-urea.Present study was conducted in cinnamon soil to identify the effects of different activation humic acid-urea treatments on wheat and maize yield,soil organic carbon with a field experiment and nitrogen mineralization with an incubation experiment.Results showed that fertilizer treatments increased the wheat and maize yields.Humic acid-urea treatment increased yield by 15%-28% and 8%-10% for wheat and maize than inorganic fertilizer treatment,and increased by 63%-81% and 55%-57% compared with the control treatment(CK),respectively.In detail the cooperation of sulfurization activation and ultrasonic treatment was better in increasing crop yield than direct mixture treatment and merely sulfurization activation treatment.There were significant differences in soil nutrients among the different fertilizer treatments.Soil NO3--N and NH4+-N contents were in an order of U+HA1,U+HA3 > U+HA2 > Urea > CK.The direct mixture treatment decreased soil NH4+-N content compared with the other activation treatment for humic acid-urea.Fertilization treatments improved soil available phosphorus and available potassium contents,whereas the humic acid addition had no effect on soil available phosphorus and available potassium contents in comparison to inorganic treatment.Humic acid-urea treatment didn't significantly influence soil organic carbon content,but enhanced soil organic carbon mineralizing rate and accumulative quantity,indeed the influences of the cooperation of sulfurization and ultrasonic activation treatment were more obvious among three treatments.There was significant positive correlation between soil organic carbon mineralization accumulative quantity and total crop yield,soil available nitrogen,potassium and phosphorus content.Compared with the control treatment,inorganic fertilizer treatment boosted soil organic nitrogen mineralization rate,but humic acid addition didn't work.The rate of soil organic nitrogen mineralization was

  18. [Conductometric microdosage of blood and urine urea by use of a semi-automatic analyser].

    Science.gov (United States)

    Hanss, M; Policard, C; Pre, J

    1977-01-01

    The authors present the principle of a new method of urea estimation based on conductimetry. Its results are compared with those given by the colorimetric method using diacetylmonoxime. Correlation of the results was satisfactory. With the apparatus studied, it was possible to estimate very simply plasma and urinary urea with low volume samples 10 microliter). The titration took 30 seconds.

  19. VUV-induced nitriding of polymer surfaces: Comparison with plasma treatments in nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Truica-Marasescu, F.; Guimond, S.; Wertheimer, M.R

    2003-08-01

    Film samples of two very pure polyolefins (low density polyethylene and biaxially oriented polypropylene) have been surface-modified by two different methods, vacuum ultraviolet (VUV) photochemistry in low pressure ammonia, and atmospheric pressure glow discharge plasma treatment in N{sub 2} gas. The results of these two treatments are compared, namely surface compositions (determined by X-ray photoelectron spectroscopy and infrared spectroscopy, ATR-FTIR) and surface energies (determined by contact angle goniometry with several probe liquids). We show that higher concentrations, [N], can be achieved by VUV photochemistry (up to 25%), that N is predominantly bonded as amine or amide groups, and that there exist certain particularities specific to each of the treatment methods investigated.

  20. VUV-induced nitriding of polymer surfaces: Comparison with plasma treatments in nitrogen

    Science.gov (United States)

    Truica-Marasescu, F.; Guimond, S.; Wertheimer, M. R.

    2003-08-01

    Film samples of two very pure polyolefins (low density polyethylene and biaxially oriented polypropylene) have been surface-modified by two different methods, vacuum ultraviolet (VUV) photochemistry in low pressure ammonia, and atmospheric pressure glow discharge plasma treatment in N 2 gas. The results of these two treatments are compared, namely surface compositions (determined by X-ray photoelectron spectroscopy and infrared spectroscopy, ATR-FTIR) and surface energies (determined by contact angle goniometry with several probe liquids). We show that higher concentrations, [N], can be achieved by VUV photochemistry (up to 25%), that N is predominantly bonded as amine or amide groups, and that there exist certain particularities specific to each of the treatment methods investigated.

  1. Surface Modification by Nitrogen Plasma Immersion Ion Implantation on Austenitic AISI 304 Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    Miguel CASTRO-COLIN; William DURRER; Jorge ALPEZ; Enrique RAMIREZ-HOMS

    2016-01-01

    Surfaces of AISI 304 austenitic stainless steel plates nitrided by plasma immersion ion implantation (PIII) technology were studied by means of Auger electron spectroscopy (AES)and X-ray photoelectron spectroscopy (XPS)to determine the effect of the nitriding process on the surface and subjacent layers.Elemental compositions obtained by AES and XPS at varying depths indicate that the saturation of N is relatively constant as a function of depth,indicating the reliability of PIII technology for subsurface saturation.It is concluded that the concentrations of both Cr and O increase with depth,the subjacent oxide is driven by the Ar+ sputtering process used to access the lower layers,and then N is bound to Cr.

  2. Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall

    CERN Document Server

    Giroud, C; Jachmich, S; Rimini, F; Beurskens, M N A; Balboa, I; Brezinsek, S; Coelho, R; Coenen, J W; Frassinetti, L; Joffrin, E; Oberkofler, M; Lehnen, M; Liu, Y; Marsen, S; K, K McCormick; Meigs, A; Neu, R; Sieglin, B; van Rooij, G; Arnoux, G; Belo, P; Brix, M; Clever, M; Coffey, I; Devaux, S; Douai, D; Eich, T; Flanagan, J; Grunhagen, S; Huber, A; Kempenaars, M; Kruezi, U; Lawson, K; Lomas, P; Lowry, C; Nunes, I; Sirinnelli, A; Sips, A C C; Stamp, M; Wiesen, S; contributors, JET-EFDA

    2013-01-01

    This paper reports the impact on confinement and power load of the high-shape 2.5MA ELMy H-mode scenario at JET of a change from an all carbon plasma facing components to an all metal wall. In preparation to this change, systematic studies of power load reduction and impact on confinement as a result of fuelling in combination with nitrogen seeding were carried out in JET-C and are compared to their counterpart in JET with a metallic wall. An unexpected and significant change is reported on the decrease of the pedestal confinement but is partially recovered with the injection of nitrogen.

  3. Experimental studies on urea degradation in seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Rajendran, A.; Joseph, T.; Reddy, C.V.G.

    The rate of urea degradation in seawater was studied under various conditions and the kinetics of urea degradation was evaluated. Urea decomposition experiments showed that the rates and quantity of ammonium oxidation were slower in the relatively...

  4. Analysis of urea distribution volume in hemodialysis.

    Science.gov (United States)

    Maduell, F; Sigüenza, F; Caridad, A; Miralles, F; Serrato, F

    1994-01-01

    According to the urea kinetic model it is considered that the urea distribution volume (V) is that of body water, and that it is distributed in only one compartment. Since the V value is different to measure, it is normal to use 58% of body weight, in spite of the fact that it may range from 35 to 75%. In this study, we have calculated the value of V by using an accurate method based on the total elimination of urea from the dialysate. We have studied the V, and also whether the different dialysis characteristics modify it. Thirty-five patients were included in this study, 19 men and 16 women, under a chronic hemodialysis programme. The dialysate was collected in a graduated tank, and the concentration of urea in plasma and in dialysate were determined every hour. Every patient received six dialysis sessions, changing the blood flow (250 or 350 ml/min), the ultrafiltration (0.5 or 1.5 l/h), membrane (cuprophane or polyacrylonitrile) and/or buffer (bicarbonate or acetate). At the end of the hemodialysis session, the V value ranged from 43 to 72% of body weight; nevertheless, this value was practically constant in every patient. The V value gradually increased throughout the dialysis session, 42.1 +/- 6.9% of body weight in the first hour, 50.7 +/- 7.5% in the second hour and 55.7 +/- 7.9% at the end of the dialysis session. The change of blood flow, ultrafiltration, membrane or buffer did not alter the results. The V value was significantly higher in men in comparison with women, 60.0 +/- 6.6% vs. 50.5 +/- 5.9% of body weight (p < 0.001).

  5. Nitrogen loss by volatilization of nitrogen fertilizers applied to coffee orchard

    Directory of Open Access Journals (Sweden)

    Anderson William Dominghetti

    2016-04-01

    Full Text Available ABSTRACT Ammonia volatilization (N-NH3 is one of the main pathways of Nitrogen loss reducing nitrogen use efficiency in coffee orchard. This work aimed at quantifying ammonia volatilization (N-NH3 losses from N-sources to be used in coffee plantations fertilization in Brazil. The experiment was conducted in the field on a dystrophic red latosol (Ferralsol in FAO's classification at the Coffee Research Sector, University of Lavras, MG, Brazil. The experimental design was of complete randomized blocks with three repetitions of the following treatments: conventional urea, ammonium nitrate and urea + 0.15% Cu and 0.4% B, urea + anionic polymers, urea + elementary sulfur (S0 + polymers, and urea + plastic resin. These N sources were split into three doses of 150 kg ha-1 and band applied. The N-NH3 losses by volatilization and variations of pH (H2O were measured, before and after N application. The N-sources contributed to reduce the soil pH, measured after the third nitrogen fertilization. The N-NH3 losses by volatilization (average from three applications was as follows: urea + anionic polymers (35.8% > conventional urea (31.2% = urea + S0 + polymers (31.0% > urea + 0.15% Cu + 0.4 % B (25.6% > urea + plastic resin (8.6% = ammonium nitrate (1.0%.

  6. UT-B Urea Transporter Localization in the Bovine Gastrointestinal Tract.

    Science.gov (United States)

    Coyle, J; McDaid, S; Walpole, C; Stewart, Gavin S

    2016-04-01

    Facilitative UT-B urea transporters play an important role in the urea nitrogen salvaging process that occurs in the gastrointestinal tract of mammals, particularly ruminants. Gastrointestinal UT-B transporters have previously been reported in various ruminant species-including cow, sheep and goat. In this present study, UT-B transporter localization was investigated in tissues throughout the bovine gastrointestinal tract. RT-PCR analysis showed that UT-B2 was the predominant UT-B mRNA transcript expressed in dorsal, ventral and cranial ruminal sacs, while alternative UT-B transcripts were present in other gastrointestinal tissues. Immunoblotting analysis detected a strong, glycosylated ~50 kDa UT-B2 protein in all three ruminal sacs. Immunolocalization studies showed that UT-B2 protein was predominantly localized to the plasma membrane of cells in the stratum basale layer of all ruminal sac papillae. In contrast, other UT-B protein staining was detected in the basolateral membranes of the surface epithelial cells lining the abomasum, colon and rectum. Overall, these findings confirm that UT-B2 cellular localization is similar in all ruminal sacs and that other UT-B proteins are located in epithelial cells lining various tissues in the bovine gastrointestinal tract.

  7. Hydrophobic recovery of VUV/NH3 modified polyolefin surfaces: Comparison with plasma treatments in nitrogen

    Science.gov (United States)

    Truica-Marasescu, F.; Guimond, S.; Jedrzejowski, P.; Wertheimer, M. R.

    2005-07-01

    Film samples of two very pure polyolefins (low density polyethylene, LDPE and biaxially oriented polypropylene, BOPP) were surface-modified by two different methods, namely vacuum ultraviolet (VUV) irradiation with a Kr resonant lamp in low-pressure NH3 gas, and atmospheric pressure glow discharge (APGD) plasma treatment in pure N2 gas. Samples were then stored in air and the time-dependence of surface properties (the surface energy and chemical composition) was monitored using several complementary surface-sensitive techniques: contact angle goniometry (CAG), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). We show that the main mechanism responsible for hydrophobic recovery is the motion of polymer chains and chain segments, which governs an apparent "loss" of functional groups, within the first monolayers of the surface (∼1 nm). Finally, comparing BOPP samples modified by both techniques, we show that aging can be reduced by crosslinking near the surface, as illustrated by depth-sensing nano-indentation measurements.

  8. Structure and tribological performance by nitrogen and oxygen plasma based ion implantation on Ti6Al4V alloy

    Science.gov (United States)

    Feng, Xingguo; Sun, Mingren; Ma, Xinxin; Tang, Guangze

    2011-09-01

    Ti6Al4V alloy was implanted with nitrogen-oxygen mixture by using plasma based ion implantation (PBII) at pulsed voltage -10, -30 and -50 kV. The implantation was up to 6 × 1017 ions/cm2 fluence. The changes in chemical composition, structure and hardness of the modified surfaces were studied by XPS and nanoindentation measurements. According to XPS, it was found that the modified layer was predominantly TiO2, but contained small amounts of TiO, Ti2O3, TiN and Al2O3 between the outmost layer and metallic substrate. Surface hardness and wear resistance of the samples increased significantly after PBII treatment, the wear rate of the sample implanted N2-O2 mixture at -50 kV decreased eight times than the untreated one. The sample implanted N2-O2 mixture showed better wear resistance than that of the sample only implanted oxygen at - 50 kV. The wear mechanism of untreated sample was abrasive-dominated and adhesive, and the wear scar of the sample implanted at -50 kV was characterized by abrasive wear-type ploughing.

  9. Enhancing the corrosion resistance of dentistry drills by plasma immersion nitrogen in implantation of AISI 434-based SS

    Energy Technology Data Exchange (ETDEWEB)

    Munoz C, A.E.; Lopez C, R.; Fuentes G, D.; Valencia A, R. [UAEM, Facultad de Quimica, Instituto Literario 100, Toluca (Mexico)]. e-mail: rlc@nuclear.inin.mx

    2007-07-01

    In order to enhance the resistance to the pitting corrosion due to asepsis processes and to avoid structural fractures in dentistry drills, a plasma immersion ion implantation (PIII) treatment using nitrogen has been performed. The selected drill samples, made of AISI 434 based stainless steel with a 0.670 mm diameter, were treated at a -1kV bias between 350 C and 450 C, this temperature being controlled by both a 20-50 {mu}s pulse width and a 200-1000 Hz repetition rate in the bias. The drills were analysed by cyclic potentiodynamic tests showing a good pitting corrosion resistance when treated at around 400 C, as follows from a resulting very low hysteresis loop. Yet, the resistance appears somehow diminished by the presence of sputtering when processed at temperatures near 450 C. It is also found that the PIII nitriding effectiveness appears to be limited by the appearance of uniform corrosion. Finally, X-ray diffraction of the samples has revealed the presence of two new phases, namely {epsilon}-Fe{sub 2}N and Fe{sub 4.4}N, while scanning electron microscopy of the treated surfaces has suggested a sputtering enhancement at the highest temperatures. (Author)

  10. Compression between ion and hard x-ray emissions from nitrogen and argon in Mather type plasma focus device

    Directory of Open Access Journals (Sweden)

    S Paghe

    2016-12-01

    Full Text Available In this study, some characteristics of a Mather type Plasma Focus (PF device such as a discharge current, pinch time, ion flux and hard x-ray intensity has been investigated simultaneously in argon and nitrogen gases separately for various operating gas pressures and charging voltages of capacitor bank. It was observed that pinch phenomena was energy and pressure dependent in current sheath as well as ion and hard x-ray emission intensity. Optimum pressure with maximum ion flux and the most intense hard x-ray showed a nearly linear dependence on the charging voltage of the device. Maximum ion flux was estimated in the order of 1018 ions per steradian in both gases. Hard x-ray emission was registered a little after discharge current and Faraday cup (FC signals. Also, optimum pressure for maximum ion flux was not the same as the pressure for intense hard x-rays. Hard x-ray intensity reached its peak at higher pressures

  11. Bacteria Adherence Properties of Nitrogen-Doped TiO2 Coatings by Plasma Surface Alloying Technique

    Institute of Scientific and Technical Information of China (English)

    WANG Hefeng; TANG Bin; LIN Naiming; LI Xiuyan; FAN Ailan; SHU Xuefeng

    2012-01-01

    In order to obtain a high-performance surface on 316L stainless steel (S.S) that can meet the requirements in medical material field environment,nitrogen-doped titanium dioxide (TiO2-xNx) was synthesized by oxidative annealing the resulted TiNx coatings in air.Titanium nitride coatings on 316L S.S were obtained by plasma surface alloying technique.The as-prepared coatings were characterized by X-ray diffraction,glow discharge optical emission spectrometer (GDOES),scanning electron microscopy and X-ray photoelectron spectroscopy,respectively.The bacteria adherence property of the TiO2-xNx coatings on S.S on the oral bacteria Streptococcus Mutans was investigated and compared with that of S.S by fluorescence microscopy.The mechanism of the bacteria adherence was discussed.The results show that the TiO2-xNx coatings are composed of anatase crystalline structure.SEM measurement indicates a rough surface morphology with three-dimensional homogenous protuberances after annealing treatment.Because of the photocatalysis and positive adhesion free energy,the TiO2-xNx coatings inhibit the bacteria adherence.

  12. Deposits from Creams Containing 20% (w/w) Urea and Suppression of Crystallization (Part 2): Novel Analytical Methods of Urea Accumulated in the Stratum Corneum by Tape stripping and Colorimetry.

    Science.gov (United States)

    Goto, Norio; Morita, Yutaka; Terada, Katsuhide

    2016-01-01

    The transfer of urea from a urea formulation to the stratum corneum varies with the formulation base and form, and impacts the formulation's therapeutic effect. Consequently, determining the amount of urea transferred is essential for developing efficient formulations. This study assessed a simple method for measuring the amount of urea accumulated in the stratum corneum. Conventional methods rely on labeling urea used in the formulation with radiocarbon ((14)C) or other radioactive isotopes (RIs), retrieving the transferred urea from the stratum corneum by tape stripping, then quantitating the urea. The handling and use of RIs, however, is subject to legal regulation and can only be performed in sanctioned facilities, so methods employing RIs are neither simple nor convenient. We therefore developed a non-radiolabel method "tape stripping-colorimetry (T-C)" that combines tape stripping with colorimetry (urease-glutamate dehydrogenase (GLDH)) for the quantitative measurement of urea. Urea in the stratum corneum is collected by tape stripping and measured using urease-GLDH, which is commonly used to measure urea nitrogen in blood tests. The results indicate that accurate urea measurement by the T-C method requires the application of 1400 mg (on hairless rats) of a 20% urea solution on a 50 cm(2) (5×10 cm) area. Further, we determined the amount of urea accumulated in the stratum corneum using formulations with different urea concentrations, and the time course of urea accumulation from formulations differing in the rate of urea crystallization. We demonstrate that the T-C method is simple and convenient, with no need for (14)C or other RIs.

  13. Effect of Low-Pressure Nitrogen DC Plasma Treatment on the Surface Properties of Biaxially Oriented Polypropylene, Poly (Methyl Methacrylate) and Polyvinyl Chloride Films

    Science.gov (United States)

    S. Hamideh, Mortazavi; Mahmood, Ghoranneviss; Soheil, Pilehvar; Sina, Esmaeili; Shamim, Zargham; S. Ebrahim, Hashemi; Hamzeh, Jodat

    2013-04-01

    In this study, commercial biaxially oriented polypropylene (BOPP), polyvinyl chloride (PVC) and poly (methyl methacrylate) (PMMA) films were treated with nitrogen plasma over different exposure times in a Pyrex tube surrounded by a DC variable magnetic field. The chemical changes that appeared on the surface of the samples were investigated using Fourier transform infrared (FT-IR) spectroscopy and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy after treatment for 2 min, 4 min and 6 min in a nitrogen plasma chamber. Effects of the plasma treatment on the surface topographies and contact angles of the untreated and plasma treated films were also analyzed by atomic force microscopy (AFM) and a contact angle measuring system. The results show that the plasma treated films become more hydrophilic with an enhanced wettability due to the formation of some new polar groups on the surface of the treated films. Moreover, at higher exposure times, the total surface energy in all treated films increased while a reduction in contact angle occurred. The behavior of surface roughness in each sample was completely different at higher exposure times.

  14. Highly efficient metal-free growth of nitrogen-doped single-walled carbon nanotubes on plasma-etched substrates for oxygen reduction.

    Science.gov (United States)

    Yu, Dingshan; Zhang, Qiang; Dai, Liming

    2010-11-03

    We have for the first time developed a simple plasma-etching technology to effectively generate metal-free particle catalysts for efficient metal-free growth of undoped and/or nitrogen-doped single-walled carbon nanotubes (CNTs). Compared with undoped CNTs, the newly produced metal-free nitrogen-containing CNTs were demonstrated to show relatively good electrocatalytic activity and long-term stability toward oxygen reduction reaction (ORR) in an acidic medium. Owing to the highly generic nature of the plasma etching technique, the methodology developed in this study can be applied to many other substrates for efficient growth of metal-free CNTs for various applications, ranging from energy related to electronic and to biomedical systems.

  15. Nonprotein nitrogen is absorbed from the large intestine and increases nitrogen balance in growing pigs fed a valine-limiting diet.

    Science.gov (United States)

    Columbus, Daniel A; Lapierre, Hélène; Htoo, John K; de Lange, Cornelis F M

    2014-05-01

    Nitrogen absorption from the large intestine, largely as ammonia and possibly as amino acids (AAs), is generally thought to be of little nutritional value to nonruminant animals and humans. Ammonia-nitrogen absorbed from the large intestine, however, may be recycled into the small intestine as urea and incorporated into microbial AAs, which may then be used by the host. A cecal infusion study was performed to determine the form in which nitrogen is absorbed from the large intestine and the impact of large intestine nitrogen supply on nitrogen balance in growing pigs. Eighteen cecally cannulated barrows (initial body weight: 22.4 ± 1.2 kg) were used to determine the effect of supplying nitrogen into the large intestine from either casein or urea on whole-body nitrogen retention and urea kinetics. Treatments were cecal infusions of saline (control), casein, or urea with nitrogen infused at a rate of 40% of nitrogen intake. In a subsample of 9 pigs, (15)N(15)N-urea was infused via i.v. during the nitrogen-balance period to determine urea kinetics. All pigs were fed a valine-limiting cornstarch-soybean meal-based diet. More than 80% of infused nitrogen was apparently absorbed. Urea flux and urinary nitrogen excretion increased (P ≤ 0.05) by the same amount for both nitrogen sources, but this increase did not fully account for the increase in nitrogen absorption from the large intestine. Whole-body nitrogen retention improved with nitrogen infusions (129 vs. 114 g/d; P 0.05) between nitrogen sources. Absorption of nitrogen from the large intestine appears to be in the form of nonprotein nitrogen, which appears to be returned to the small intestine via urea and used there for microbial AA production and should therefore be considered when determining nitrogen and AA supply and requirements.

  16. Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan, E-mail: alan.doolittle@ece.gatech.edu [Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Bresnahan, Rich C. [Veeco Instruments, St. Paul, Minnesota 55127 (United States)

    2015-10-21

    Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N{sub 2} while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N{sub 2} and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10{sup 16} to 3.8 × 10{sup 19} cm{sup −3} were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10{sup 15} cm{sup −3}. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be

  17. Effect of abomasal glucose infusion on alanine metabolism and urea production in sheep.

    Science.gov (United States)

    Obitsu, T; Bremner, D; Milne, E; Lobley, G E

    2000-08-01

    The effect of abomasal infusion of glucose (120 kJ/d per kg body weight (BW)0.75, 758 mmol/d) on urea production, plasma alanine-N flux rate and the conversion of alanine-N to urea was studied in sheep offered a low-N diet at limited energy intake (500 kJ/d per kg BW0.75), based on hay and grass pellets. Glucose provision reduced urinary N (P = 0.040) and urea (P = 0.009) elimination but this was offset by poorer N digestibility. Urea-N production was significantly reduced (822 v. 619 mmol/d, P = 0.024) by glucose while plasma alanine-N flux rate was elevated (295 v. 342 mmol/d, P = 0.011). The quantity of urea-N derived from alanine tended to be decreased by glucose (127 v. 95 mmol/d) but the fraction of urea production from alanine was unaltered (15%). Plasma urea and alanine concentrations (plus those of the branched chain amino acids) decreased in response to exogenous glucose, an effect probably related to enhanced anabolic usage of amino acids and lowered urea production.

  18. Fast incorporation of primary amine group into polylactide surface for improving C₂C₁₂ cell proliferation using nitrogen-based atmospheric-pressure plasma jets.

    Science.gov (United States)

    Yang, Yi-Wei; Wu, Jane-Yii; Liu, Chih-Tung; Liao, Guo-Chun; Huang, Hsuan-Yu; Hsu, Ray-Quen; Chiang, Ming-Hung; Wu, Jong-Shinn

    2014-01-01

    In this article, we report the development of the fast incorporation of primary amine functional groups into a polylactide (PLA) surface using the post-discharge jet region of an atmospheric-pressure nitrogen-based dielectric barrier discharge (DBD). Plasma treatments were carried out in two sequential steps: (1) nitrogen with 0.1% oxygen addition, and (2) nitrogen with 5% ammonia addition. The analyses show that the concentration of N/C ratio, surface energy, contact angle, and surface roughness of the treated PLA surface can reach 19.1%, 70.5 mJ/m(2), 38° and 73.22 nm, respectively. In addition, the proposed two-step plasma treatment procedure can produce a PLA surface exhibiting almost the same C2C12 cell attachment and proliferation performance as that of the conventional gelatin coating method. Most importantly, the processing/preparation time is reduced from 13-15 h (gelatin coating method) to 5-15 min (two-step plasma treatment), which is very useful in practical applications.

  19. Ocean Urea Fertilization for Carbon Credits Poses High Ecological Risks

    Science.gov (United States)

    Glibert, Patricia M.; Azanza, Rhodora; Burford, Michele; Furuya, Ken; Abal, Eva; Al-Azri, Adnan; Al-Yamani, Faiza; Andersen, Per; Beardall, John; Berg, G. Mine; Brand, Larry; Bronk, Deborah; Brookes, Justin; Burkholder, JoAnn M.; Cembella, Allan; Cochlan, William P.; Collier, Jackie; Collos, Yves; Diaz, Robert; Doblin, Martina; Drennen, Thomas; Dyhrman, Sonya; Fukuyo, Yasuwo; Furnas, Miles; Galloway, James; Granéli, Edna; Ha, Dao Viet; Hallegraeff, Gustaaf; Harrison, John; Harrison, Paul J.; Heil, Cynthia A.; Heimann, Kirsten; Howarth, Robert; Jauzein, Cécile; Kana, Austin A.; Kana, Todd M.; Kim, Hakgyoon; Kudela, Raphael; Legrand, Catherine; Mallin, Michael; Mulholland, Margaret; Murray, Shauna; O’Neil, Judith; Pitcher, Grant; Qi, Yuzao; Rabalais, Nancy; Raine, Robin; Seitzinger, Sybil; Solomon, Caroline; Stoecker, Diane K.; Usup, Gires; Wilson, Joanne; Yin, Kedong; Zhou, Mingjiang; Zhu, Mingyuan

    2017-01-01

    The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed. PMID:18439628

  20. Ocean urea fertilization for carbon credits poses high ecological risks.

    Science.gov (United States)

    Glibert, Patricia M; Azanza, Rhodora; Burford, Michele; Furuya, Ken; Abal, Eva; Al-Azri, Adnan; Al-Yamani, Faiza; Andersen, Per; Anderson, Donald M; Beardall, John; Berg, G Mine; Brand, Larry; Bronk, Deborah; Brookes, Justin; Burkholder, Joann M; Cembella, Allan; Cochlan, William P; Collier, Jackie L; Collos, Yves; Diaz, Robert; Doblin, Martina; Drennen, Thomas; Dyhrman, Sonya; Fukuyo, Yasuwo; Furnas, Miles; Galloway, James; Granéli, Edna; Ha, Dao Viet; Hallegraeff, Gustaaf; Harrison, John; Harrison, Paul J; Heil, Cynthia A; Heimann, Kirsten; Howarth, Robert; Jauzein, Cécile; Kana, Austin A; Kana, Todd M; Kim, Hakgyoon; Kudela, Raphael; Legrand, Catherine; Mallin, Michael; Mulholland, Margaret; Murray, Shauna; O'Neil, Judith; Pitcher, Grant; Qi, Yuzao; Rabalais, Nancy; Raine, Robin; Seitzinger, Sybil; Salomon, Paulo S; Solomon, Caroline; Stoecker, Diane K; Usup, Gires; Wilson, Joanne; Yin, Kedong; Zhou, Mingjiang; Zhu, Mingyuan

    2008-06-01

    The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed.

  1. National Urea Cycle Disorders Foundation

    Science.gov (United States)

    ... triggers undiagnosed fatal urea cycle disorder in Tennessee wife and teacher. Story . More information about bariatric surgery ... with sodium phenylbutyrate may decrease liver dysfunction in patients with ASA. Details "IN TRIBUTE TO HER SON, ...

  2. Understanding strategy of nitrate and urea assimilation in a Chinese strain of Aureococcus anophagefferens through RNA-seq analysis.

    Directory of Open Access Journals (Sweden)

    Hong-Po Dong

    Full Text Available Aureococcus anophagefferens is a harmful alga that dominates plankton communities during brown tides in North America, Africa, and Asia. Here, RNA-seq technology was used to profile the transcriptome of a Chinese strain of A. anophagefferens that was grown on urea, nitrate, and a mixture of urea and nitrate, and that was under N-replete, limited and recovery conditions to understand the molecular mechanisms that underlie nitrate and urea utilization. The number of differentially expressed genes between urea-grown and mixture N-grown cells were much less than those between urea-grown and nitrate-grown cells. Compared with nitrate-grown cells, mixture N-grown cells contained much lower levels of transcripts encoding proteins that are involved in nitrate transport and assimilation. Together with profiles of nutrient changes in media, these results suggest that A. anophagefferens primarily feeds on urea instead of nitrate when urea and nitrate co-exist. Furthermore, we noted that transcripts upregulated by nitrate and N-limitation included those encoding proteins involved in amino acid and nucleotide transport, degradation of amides and cyanates, and nitrate assimilation pathway. The data suggest that A. anophagefferens possesses an ability to utilize a variety of dissolved organic nitrogen. Moreover, transcripts for synthesis of proteins, glutamate-derived amino acids, spermines and sterols were upregulated by urea. Transcripts encoding key enzymes that are involved in the ornithine-urea and TCA cycles were differentially regulated by urea and nitrogen concentration, which suggests that the OUC may be linked to the TCA cycle and involved in reallocation of intracellular carbon and nitrogen. These genes regulated by urea may be crucial for the rapid proliferation of A. anophagefferens when urea is provided as the N source.

  3. 日粮中限制赖氨酸水平对育肥猪生长性能和血液尿素氮的影响%Effect of dietary lysine restriction on growth performance and serum urea nitrogen in finishing pigs

    Institute of Scientific and Technical Information of China (English)

    金英海; 耿春银; 梁婉薪; 张敏

    2012-01-01

    试验研究日粮中限制赖氨酸水平对育肥猪生长性能和血液尿素氮的影响.试验选择健康的体重为(59.92±0.99) kg的杂交(约克夏×长白×杜洛克)育肥猪60头,随机分为3个处理组,每个处理组5个重复,每个重复4头猪,进行了8周的饲养试验.分为对照组是基础日粮中养分参照NRC(1998)饲养标准、日粮中赖氨酸水平限制15%和限制30%的3个处理组.结果表明:试验组在育肥期(0~8周)和育肥前期(0~4周),赖氨酸水平的降低,试验末重、平均日增重、平均日采食量(P<0.01)、饲料效率呈显著降低趋势(P<0.05).对照组与试验组之间差异显著(P<0.05).育肥后期(5~8周)血液尿素氮的浓度有显著性差异(P<0.01).%This experiment was to study the effect of dietary lysine restriction on growth performance and serum urea nitrogen in finishing pigs. 60 hybrid fattening pigs (York summer× Landrace X Duroc) with the initial body weight of (59.92±0.99) kg were randomly divided into 3 groups with 5 repetitions, each repetition had 4 pigs, the experiment lasted 8 weeks. The 3 groups were basic diet formulated by NRC(1998), dietary with lysine restriction level of 15% and 30% Respectively. The result indicated that, in the fattening time(0~8 week) and the earlier finishing period(0~4 week), with the decrease of dietary lysine level, the final body weight, average daily weight gain, average daily feed intake(P<0.01) and feed efficiency of experimental groups were significantly decreased(P<0.05). The blood urea nitrogen density has the significant differences in the latter finishing period(5~8 week).

  4. Evaporation of urea at atmospheric pressure.

    Science.gov (United States)

    Bernhard, Andreas M; Czekaj, Izabela; Elsener, Martin; Wokaun, Alexander; Kröcher, Oliver

    2011-03-31

    Aqueous urea solution is widely used as reducing agent in the selective catalytic reduction of NO(x) (SCR). Because reports of urea vapor at atmospheric pressure are rare, gaseous urea is usually neglected in computational models used for designing SCR systems. In this study, urea evaporation was investigated under flow reactor conditions, and a Fourier transform infrared (FTIR) spectrum of gaseous urea was recorded at atmospheric pressure for the first time. The spectrum was compared to literature data under vacuum conditions and with theoretical spectra of monomolecular and dimeric urea in the gas phase calculated with the density functional theory (DFT) method. Comparison of the spectra indicates that urea vapor is in the monomolecular form at atmospheric pressure. The measured vapor pressure of urea agrees with the thermodynamic data obtained under vacuum reported in the literature. Our results indicate that considering gaseous urea will improve the computational modeling of urea SCR systems.

  5. 21 CFR 862.1515 - Nitrogen (amino-nitrogen) test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nitrogen (amino-nitrogen) test system. 862.1515... Systems § 862.1515 Nitrogen (amino-nitrogen) test system. (a) Identification. A nitrogen (amino-nitrogen) test system is a device intended to measure amino acid nitrogen levels in serum, plasma, and...

  6. Alcoholic Hepatitis Markedly Decreases the Capacity for Urea Synthesis.

    Directory of Open Access Journals (Sweden)

    Emilie Glavind

    Full Text Available Data on quantitative metabolic liver functions in the life-threatening disease alcoholic hepatitis are scarce. Urea synthesis is an essential metabolic liver function that plays a key regulatory role in nitrogen homeostasis. The urea synthesis capacity decreases in patients with compromised liver function, whereas it increases in patients with inflammation. Alcoholic hepatitis involves both mechanisms, but how these opposite effects are balanced remains unclear. Our aim was to investigate how alcoholic hepatitis affects the capacity for urea synthesis. We related these findings to another measure of metabolic liver function, the galactose elimination capacity (GEC, as well as to clinical disease severity.We included 20 patients with alcoholic hepatitis and 7 healthy controls. The urea synthesis capacity was quantified by the functional hepatic nitrogen clearance (FHNC, i.e., the slope of the linear relationship between the blood α-amino nitrogen concentration and urea nitrogen synthesis rate during alanine infusion. The GEC was determined using blood concentration decay curves after intravenous bolus injection of galactose. Clinical disease severity was assessed by the Glasgow Alcoholic Hepatitis Score and Model for End-Stage Liver Disease (MELD score.The FHNC was markedly decreased in the alcoholic hepatitis patients compared with the healthy controls (7.2±4.9 L/h vs. 37.4±6.8 L/h, P<0.01, and the largest decrease was observed in those with severe alcoholic hepatitis (4.9±3.6 L/h vs. 9.9±4.9 L/h, P<0.05. The GEC was less markedly reduced than the FHNC. A negative correlation was detected between the FHNC and MELD score (rho = -0.49, P<0.05.Alcoholic hepatitis markedly decreases the urea synthesis capacity. This decrease is associated with an increase in clinical disease severity. Thus, the metabolic failure in alcoholic hepatitis prevails such that the liver cannot adequately perform the metabolic up-regulation observed in other stressful

  7. Alcoholic Hepatitis Markedly Decreases the Capacity for Urea Synthesis

    Science.gov (United States)

    Glavind, Emilie; Aagaard, Niels Kristian; Grønbæk, Henning; Møller, Holger Jon; Orntoft, Nikolaj Worm; Vilstrup, Hendrik; Thomsen, Karen Louise

    2016-01-01

    Background and Aim Data on quantitative metabolic liver functions in the life-threatening disease alcoholic hepatitis are scarce. Urea synthesis is an essential metabolic liver function that plays a key regulatory role in nitrogen homeostasis. The urea synthesis capacity decreases in patients with compromised liver function, whereas it increases in patients with inflammation. Alcoholic hepatitis involves both mechanisms, but how these opposite effects are balanced remains unclear. Our aim was to investigate how alcoholic hepatitis affects the capacity for urea synthesis. We related these findings to another measure of metabolic liver function, the galactose elimination capacity (GEC), as well as to clinical disease severity. Methods We included 20 patients with alcoholic hepatitis and 7 healthy controls. The urea synthesis capacity was quantified by the functional hepatic nitrogen clearance (FHNC), i.e., the slope of the linear relationship between the blood α-amino nitrogen concentration and urea nitrogen synthesis rate during alanine infusion. The GEC was determined using blood concentration decay curves after intravenous bolus injection of galactose. Clinical disease severity was assessed by the Glasgow Alcoholic Hepatitis Score and Model for End-Stage Liver Disease (MELD) score. Results The FHNC was markedly decreased in the alcoholic hepatitis patients compared with the healthy controls (7.2±4.9 L/h vs. 37.4±6.8 L/h, P<0.01), and the largest decrease was observed in those with severe alcoholic hepatitis (4.9±3.6 L/h vs. 9.9±4.9 L/h, P<0.05). The GEC was less markedly reduced than the FHNC. A negative correlation was detected between the FHNC and MELD score (rho = -0.49, P<0.05). Conclusions Alcoholic hepatitis markedly decreases the urea synthesis capacity. This decrease is associated with an increase in clinical disease severity. Thus, the metabolic failure in alcoholic hepatitis prevails such that the liver cannot adequately perform the metabolic up

  8. Urease inhibitor (NBPT and efficiency of single or split application of urea in wheat crop

    Directory of Open Access Journals (Sweden)

    Marcelo Curitiba Espindula

    2014-04-01

    Full Text Available NBPT (N-(n-butyl thiophosphoric triamide, a urease inhibitor, has been reported as one of the most promising compounds to maximize urea nitrogen use in agricultural systems. The objective of this study was to evaluate the performance of irrigated wheat fertilized with urea or urea + NBPT as single or split application. The experiment was conducted from June to October 2006 in Viçosa, MG, Brazil. The experimental design followed a 2×2 factorial scheme, in which urea or urea + NBPT were combined with two modes of application: full dose at sowing (60kg ha-1 or split (20kg ha-1 at sowing + 40kg ha-1 as topdressing at tillering, in randomized blocks with ten replications. The split application of nitrogen fertilization does not improve the yield wheat under used conditions. The use of urease inhibitor improves the grain yield of wheat crop when urea is applied in topdressing at tillering, but its use does not promote difference when urea is applied in the furrow at planting.

  9. Urea-SCR Temperature Investigation for NOx Control of Diesel Engine

    Directory of Open Access Journals (Sweden)

    Asif Muhammad

    2015-01-01

    Full Text Available SCR (selective catalytic reduction system is continuously being analyzed by many researchers worldwide on various concerns due to the stringent nitrogen oxides (NOx emissions legislation for heavy-duty diesel engines. Urea-SCR includes AdBlue as urea source, which subsequently decomposes to NH3 (ammonia being the reducing agent. Reaction temperature is a key factor for the performance of urea-SCR system, as urea decomposition rate is sensitive to a specific temperature range. This particular study was directed to investigate the temperature of the SCR system in diesel engine with the objective to confirm that whether the appropriate temperature is attained for occurrence of urea based catalytic reduction or otherwise and how the system performs on the prescribed temperature range. Diesel engine fitted with urea-SCR exhaust system has been operated on European standard cycle for emission testing to monitor the temperature and corresponding nitrogen oxides (NOx values on specified points. Moreover, mathematical expressions for approximation of reaction temperature are also proposed which are derived by applying energy conservation principal and gas laws. Results of the investigation have shown that during the whole testing cycle system temperature has remained in the range where urea-SCR can take place with best optimum rate and the system performance on account of NOx reduction was exemplary as excellent NOx conversion rate is achieved. It has also been confirmed that selective catalytic reduction (SCR is the best suitable technology for automotive engine-out NOx control.

  10. Intercalation of urea into kaolinite for preparation of controlled release fertilizer

    Directory of Open Access Journals (Sweden)

    Mahdavi Fariba

    2014-01-01

    Full Text Available In this study urea was intercalated between layers of kaolinite by dry grinding technique to be used for preparing controlled release fertilizer. X-ray powder diffraction (XRPD patterns confirmed the intercalation of urea into kaolinite by the significant expansion of the basal spacing of kaolinite layers from 0.710 nm to 1.090 nm. Fourier transform infrared spectroscopy (FT-IR also confirmed the hydrogen bonding between urea and kaolinite. Based on CHNS elemental analysis, 20% (wt. urea was intercalated between kaolinite layers. The urea-intercalated kaolinite was mixed with hydroxypropyl methylcellulose (HPMC binder and was granulated to prepare the nitrogen-based controlled release fertilizer. To study the nitrogen release behavior of granules, ultraviolet/visible (UV-Vis spectroscopy was used through the diacetyl monoxime (DAM colorimetric method. The result of UV-Vis spectroscopy showed that intercalation of urea into kaolinite decreased the nitrogen release from 25.50 to 13.66 % after 24 hours and from 98.15 to 70.01% after 30 days incubation in water. According to the results, the prepared controlled release fertilizer (CRF behaved according to the standard for CRFs.

  11. Impairment of liver synthetic function and the production of plasma proteins in primary breast cancer patients on doxorubicincyclophosphamide (AC) protocol.

    Science.gov (United States)

    Saleem, Zikria; Ahmad, Mobasher; Hashmi, Furqan Khurshid; Saeed, Hamid; Aziz, Muhammad Tahir

    2016-09-01

    Doxorubicin and Cyclophosphamide (AC protocol) combination is usually considered as a first line therapy in newly diagnosed breast cancer patients. Thus, a retrospective observational study was conducted to monitor the effect of AC protocol on liver synthetic functions and production of plasma proteins in breast cancer patients, reporting to specialized cancer care hospital of Lahore, Pakistan. A total of 75 patients (n=75) on AC protocol with breast cancer were observed in this study. The patient data including age, gender, body surface area, dosage, disease status and laboratory biochemical values were recorded by reviewing historical treatment records. Pre-treatment values were taken as baseline values for albumin, globulin, blood urea nitrogen (BUN), albumin/globulin (A/G) ratio and total proteins. The baseline values were compared after each cycle of by applying ANOVA using statistical tool SPSS® version 21. The plasma levels of blood urea nitrogen (BUN), total protein and globulin dropped significantly (p0.05). The A/G ratio level increased (pliver synthetic functions as observed by decreased blood urea nitrogen (BUN) and plasma protein levels.

  12. KOMBINASI PENAMBAHAN UREA DAN EM-4 TERHADAP KUALITAS BOKASHI CAIR

    Directory of Open Access Journals (Sweden)

    Muhammad Dzulfikri Haidla

    2016-06-01

    Full Text Available The objectives of the study is to determine the effect of EM-4 and Urea addition on the liquid Bokashi quality of chicken manure. The field research was conducted at California Papaya Farm Pulau Sari, Pelaihari, and the nutrient levels of liquid Bokashi are then analyzed in the laboratory of PPLH Banjarbaru. The research was conducted from February to March 2015. It used Complete Randomized Design (CRD of factorial pattern 2 with three levels of treatment and three replications, the first factor is the addition of urea, consisting of three levels those are 0 g, 7.5 g, 15 g, the second factor is the addition of EM-4, consisting of three levels those are 0 ml, 25 ml, 50 ml, so that the number of trial units becomes 27 units. The variables measured are the Levels of Nitrogen (N, Phosphorous (P, Potassium (K, C-Organic, temperature, pH, color, smell, and texture. Quantitative observation data were analyzed using ANOVA and Duncan's Multiple Range Test (DMRT, while the qualitative observation data were analyzed using Kruskal-Wallis test. The results showed that the interaction between the addition of EM-4 and Urea were able to increase levels of nutrients N, P, K, C-Organic, and the temperature of the liquid Bokashi. Overall obtained treatment provision of EM-4 25 ml and 15 g Urea is the best treatment among other treatments. The addition of EM-4 was able to increase the levels of N, K, C-Organic and liquid Bokashi temperature, but it is unable to increase levels of the element P. Giving Urea can increase the levels of nutrients N, P, K, C-Organic, and the temperature of the liquid Bokashi. In observation of the organoleptic treatment with the addition of EM-4 and Urea, it tends to produce materials with better color, smell, and texture than the control treatment.

  13. Structural properties of Al{sub 2}O{sub 3}/AlN thin film prepared by magnetron sputtering of Al in HF-activated nitrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Dallaeva, D.S. [Dagestan State Technical University, av. I. Shamilya 70a, Machachkala, 367015 Dagestan Republic (Russian Federation); Dagestan State University, M. Gadgieva street, Machachkala, 367001 Dagestan Republic (Russian Federation); Brno University of Technology, Faculty of Electrical Engineering and Communication, Physics Department, Technicka 8, 616 00 Brno (Czech Republic); Bilalov, B.A.; Gitikchiev, M.A.; Kardashova, G.D.; Safaraliev, G.K. [Dagestan State Technical University, av. I. Shamilya 70a, Machachkala, 367015 Dagestan Republic (Russian Federation); Dagestan State University, M. Gadgieva street, Machachkala, 367001 Dagestan Republic (Russian Federation); Tomanek, P., E-mail: tomanek@feec.vutbr.cz [Brno University of Technology, Faculty of Electrical Engineering and Communication, Physics Department, Technicka 8, 616 00 Brno (Czech Republic); Skarvada, P. [Brno University of Technology, Faculty of Electrical Engineering and Communication, Physics Department, Technicka 8, 616 00 Brno (Czech Republic); Smith, S. [South Dakota School of Mines and Technology, Physics Department, 501 E. St. Joseph St, Rapid City, SD 57701 (United States)

    2012-12-30

    A process for ion-plasma formation of aluminum nitride (AlN) nanolayers on nitrided sapphire (Al{sub 2}O{sub 3}) substrates is presented. The method is based on the direct current magnetron sputtering of a high-purity aluminum target in the presence of an argon-nitrogen gas mix and high frequency-activated nitrogen plasma. The method, combined with ion etching, produced matched layers by nitration of Al{sub 2}O{sub 3} in the (0001) plane, and formation of high quality AlN epilayers on this surface was observed. The processing characteristics and morphology dependence on synthesis parameters were studied using atomic force microscopy. - Highlights: Black-Right-Pointing-Pointer Technology based on plasma processes was used. Black-Right-Pointing-Pointer Shemical composition of elements in the layers was analyzed. Black-Right-Pointing-Pointer Near-surface layer was obtained on the sapphire substrate by nitridation. Black-Right-Pointing-Pointer Increasing of substrate temperature stimulates the growth of layer perfection. Black-Right-Pointing-Pointer Morphology is connected with growth mechanism and the structure of substrate.

  14. Charge-state and element-resolved ion energies in the cathodic arc plasma from composite AlCr cathodes in argon, nitrogen and oxygen atmospheres

    CERN Document Server

    Franz, Robert; Anders, André

    2014-01-01

    The energy distribution functions of ions in the cathodic arc plasma using composite AlCr cathodes were measured as a function of the background gas pressure in the range 0.5 to 3.5 Pa for different cathode compositions and gas atmospheres. The most abundant aluminium ions were Al$^{+}$ regardless of the background gas species, whereas Cr$^{2+}$ ions were dominating in Ar and N$_2$ and Cr$^{+}$ in O$_2$ atmospheres. The energy distributions of the aluminium and chromium ions typically consisted of a high energy fraction due to acceleration in the expanding plasma plume from the cathode spot and thermalised ions that were subjected to collisions in the plasma cloud. The fraction of the latter increased with increasing background gas pressure. Atomic nitrogen and oxygen ions showed similar energy distributions as the aluminium and chromium ions, whereas the argon and molecular nitrogen and oxygen ions were mainly thermalised. In addition to the positively charged metal and gas ions, negatively charged oxygen an...

  15. Autotrophic ammonia oxidation at low pH through urea hydrolysis.

    Science.gov (United States)

    Burton, S A; Prosser, J I

    2001-07-01

    Ammonia oxidation in laboratory liquid batch cultures of autotrophic ammonia oxidizers rarely occurs at pH values less than 7, due to ionization of ammonia and the requirement for ammonium transport rather than diffusion of ammonia. Nevertheless, there is strong evidence for autotrophic nitrification in acid soils, which may be carried out by ammonia oxidizers capable of using urea as a source of ammonia. To determine the mechanism of urea-linked ammonia oxidation, a ureolytic autotrophic ammonia oxidizer, Nitrosospira sp. strain NPAV, was grown in liquid batch culture at a range of pH values with either ammonium or urea as the sole nitrogen source. Growth and nitrite production from ammonium did not occur at pH values below 7. Growth on urea occurred at pH values in the range 4 to 7.5 but ceased when urea hydrolysis was complete, even though ammonia, released during urea hydrolysis, remained in the medium. The results support a mechanism whereby urea enters the cells by diffusion and intracellular urea hydrolysis and ammonia oxidation occur independently of extracellular pH in the range 4 to 7.5. A proportion of the ammonia produced during this process diffuses from the cell and is not subsequently available for growth if the extracellular pH is less than 7. Ureolysis therefore provides a mechanism for nitrification in acid soils, but a proportion of the ammonium produced is likely to be released from the cell and may be used by other soil organisms.

  16. Influence of temperature on properties of nitrogen plasma source ion implantation (N-PSII) of Ti6A14V alloy

    CERN Document Server

    Geng Man; Zhao Qing

    2001-01-01

    Specimens of Ti6Al4V alloy were implanted with nitrogen plasma source ion implantation (N-PSII) at temperatures between 100 degree C and 600 degree C to a ion dose of 4 x 10 sup 1 sup 7 cm sup - sup 2. Auger Electron Spectroscopy (AES) was used to determine the nitrogen concentration depth profiles. Microhardness measurements and pin-on-disk wear test were performed to evaluate the improvements of the surface modification. Glancing angle X-ray diffraction (XRD) was employed to determine the phases presented in the surface modified layer. The thickness of implanted layer increased by about an order of magnitude when the temperature was elevated from 100 degree C to 600 degree C. Higher surface hardness and wear resistance was also obtained at higher temperature. Scanning electron microscopy (SEM) showed distinct microstructural changes and the presence of titanium nitrides in the implanted surface

  17. Effects of nitrogen plasma treatment on the electrical property and band structure of few-layer MoS{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Su, Ting-Hong; Lin, Yow-Jon, E-mail: rzr2390@yahoo.com.tw [Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan (China)

    2016-01-18

    Few-layer MoS{sub 2} prepared by the chemical vapor deposition method was treated with nitrogen plasma under different radio-frequency (rf) power conditions in order to experimentally study the change in the electrical property. Control of the rf power could change the work function of MoS{sub 2} from 5.40 eV to 5.06 eV. It is shown that the increased rf power leads to the increased (reduced) number of nitrogen (oxygen) atoms, increasing the electron concentration and shifting the Fermi level toward conduction band. The sensitivity of the work function to the rf power provides an opport