Relevant bibliographies by topics / Nitrogen-limited

Academic literature on the topic 'Nitrogen-limited'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Nitrogen-limited"

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Unkovich, Murray, Nicola Jamieson, Ross Monaghan, and Declan Barraclough. "Nitrogen mineralisation and plant nitrogen acquisition in a nitrogen-limited calcareous grassland." Environmental and Experimental Botany 40, no. 3 (December 1998): 209–19. http://dx.doi.org/10.1016/s0098-8472(98)00038-0.

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Knight, K. "Nitrogen-limited spiny dogfish scavenge ammonia." Journal of Experimental Biology 218, no. 2 (January 15, 2015): 163. http://dx.doi.org/10.1242/jeb.118547.

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Elrifi, IR, and DH Turpin. "Transient photosynthetic responses of nitrogen limited macroalgae to nitrogen addition." Marine Ecology Progress Series 20 (1985): 253–58. http://dx.doi.org/10.3354/meps020253.

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Ishii, Ken-Ichiro, Wen Liu, and Shigeki Sawayama. "Lipid formation and morphological changes in Chaetoceros (Bacillariophyceae) species under nitrogen-limited conditions." Nova Hedwigia, Beihefte 148 (February 27, 2019): 89–100. http://dx.doi.org/10.1127/nova-suppl/2019/103.

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Watt, D. A., A. M. Amory, and C. F. Cresswell. "Interactions between nitrogen metabolism and photosynthesis in nitrogen-limited Monoraphidium falcatus." South African Journal of Botany 55, no. 6 (December 1989): 543–50. http://dx.doi.org/10.1016/s0254-6299(16)31126-7.

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VERKROOST, A. W. M., and M. J. WASSEN. "A Simple Model for Nitrogen-limited Plant Growth and Nitrogen Allocation." Annals of Botany 96, no. 5 (August 12, 2005): 871–76. http://dx.doi.org/10.1093/aob/mci239.

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Hammad, Hafiz Mohkum, Wajid Farhad, Farhat Abbas, Shah Fahad, Shafqat Saeed, Wajid Nasim, and Hafiz Faiq Bakhat. "Maize plant nitrogen uptake dynamics at limited irrigation water and nitrogen." Environmental Science and Pollution Research 24, no. 3 (November 8, 2016): 2549–57. http://dx.doi.org/10.1007/s11356-016-8031-0.

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Safronov, A. A., V. V. Gorbunov, V. I. Tazetdinov, and G. V. Torokhov. "Production of steel with limited nitrogen content." Steel in Translation 43, no. 5 (May 2013): 302–5. http://dx.doi.org/10.3103/s0967091213050161.

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Holmes, Robert M., Jeremy B. Jones, Stuart G. Fisher, and Nancy B. Grimm. "Denitrification in a nitrogen-limited stream ecosystem." Biogeochemistry 33, no. 2 (May 1996): 125–46. http://dx.doi.org/10.1007/bf02181035.

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Furigo, A., and M. H. J�rgensen. "Nitrogen limited growth of a methanotrophic culture." Bioprocess Engineering 9, no. 2-3 (May 1993): 119–27. http://dx.doi.org/10.1007/bf00369041.

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Dissertations / Theses on the topic "Nitrogen-limited"

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Fisher, Jane. "Nitrogen-limited lakes : occurrence, basis and characteristics." Thesis, University of Liverpool, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288200.

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Cao, Keping. "Simultaneous Removal of Carbon and Nitrogen by Using a Single Bioreactor for Land Limited Application." Thesis, Water Resources Research Center, University of Hawaii at Manoa, 1998. http://hdl.handle.net/10125/22230.

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An Entrapped-Mixed-Microbial-Cell (EMMC) process was investigated for its simultaneous removal of carbon and nitrogen in a single bioreactor with the influent COD/N ratio varying from 4 to 15 and influent alkalinity of 140 mg CaCO3/L and 230 mg CaCO3/L. The reactor was operated with alternate schedules of intermittent aeration. Two different sizes of carriers (10 * 10 * 10 mm3 and 20 * 20 * 20 mm3) were studied. The medium carrier (10 * 10 * 10 mm3) system presents higher nitrogen removal and COD removal compared to the large carrier system. The nitrogen removal efficiency is related to the ratio of COD/N in the influent. With the increase of the COD/N ration in the influent, the nitrogen removal efficiency is increased. The average reductions of nitrogen were over 92% and the average reductions of SCOD and BOD5 are over 95% and 97%, respectively, in the medium carrier system. This is operated at the HRT of 12 hours and 0.5 hour aeration and 2 hours of non-aeration, and the COD/N ratio of 15 in the influent. Changing alkalinity from 140 to 230 mg CaCO3/L has no effect in both large and medium carriers for the nitrogen removal efficiency. The pH, oxidation – reduction potential (ORP) and dissolved oxygen (DO) were used to monitor the biological nitrogen removal. It was found that the ORP (range from -100 to 300 mV) can be used to provide better effluent quality measured as total-nitrogen of less than 10 mg/L. Also, the impact of influent COD/N ratio on the effluent quality (measured as Inorg.-nitrogen) for the EMMC process is very important. Compared to other two compact biological wastewater treatment processes, membrane bioreactor (MBR) and moving bed biofilm reactor (MBBR), the EMMC process with the intermittent aeration has higher removal efficiencies of carbon and nitrogen, easier operation, lower O&M cost, lower energy requirement, and more compact. The total cost requirement is less than $3.27 per 1000 gallons (3.785 m 3) of treated settled domestic sewage per day. It is apparent that the EMMC process is technically feasible for the simultaneous removal of carbon and nitrogen under the operation on a schedule of intermittent aeration and suitable to be used for replacement or upgrading of existing treatment plant at land limited area.
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Bernard, Rebecca Jane. "Effects of light and nutrient supply on stable isotope composition and fractionation in nitrogen-limited seagrass beds." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/1599.

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This experiment investigated causes of seasonality of δ15N and δ13C values in Thalassia testudinum leaf tissue by manipulating plant demand and nutrient supply in situ for 13 months. I clearly demonstrated that seagrass elemental content, stable C and N isotopic content, morphology and the concentration of NH4+ seagrass porewaters directly respond to manipulations of resources and also by the plant demand for nutrients to support growth. Isotopic values displayed marked seasonality with heavier values found in summer (δ15N=5.0% δ13C=-5.7%o) and lighter values in winter (δ15N=1.7%o δ13C= -9.4%o). Calculations of Δ (δ15N source DIN- δ15N plant product) indicate that T. testudinum is able to strongly fractionate against source pool DIN. Interpretation of an enriched N signature as pollution-derived must first recognize the isotopic seasonality of the plant demand relative to the nutrient supply. Only when these links have been explained can the full relevance of δ15N values be applied.
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Capuno, Romeo Evasco. "Mathematical Modeling for Nitrogen Removal via a Nitritation: Anaerobic Ammonium Oxidation-Coupled Biofilm in a Hollow Fiber Membrane Bioreactor and a Rotating Biological Contactor." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/34959.

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Mathematical models of a nitritation: anaerobic ammonia oxidation (anammox)-coupled biofilm in a counter-diffusion hollow fiber membrane bioreactor (HFMBR) and a nitritation: anammox-coupled biofilm in a co-diffusion rotating biological contactor (RBC) were developed and implemented using AQUASIM. Four different start-up scenarios on the nitritation: anammox-coupled biofilm in an HFMBR were investigated. The supply of oxygen was simulated with the flow through the lumen of the hollow fiber membrane. For the four scenarios, two scenarios investigated the start-up when nitrite was supplied in the feed while the other two scenarios investigated when the source of nitrite was through nitritation only. The results showed that the presence of nitrite in the feed facilitated the start-up of the reactor. In addition, the results also showed that increasing oxygen flux through the membrane up to a certain ratio of ammonia flux with oxygen flux affected reactor performance by improving nitrogen removal and reducing start up time. For the nitritation: anammox-coupled biofilm in an RBC, four different process options were investigated: the number of reactors, the initial anammox (AnAOB) biomass fraction, the bulk oxygen concentration and the maximum biofilm thickness. Modeling results revealed that the steady state total nitrogen removal in RBC reactors in series occurred primarily in the first and second reactors. It is concluded that the number of reactors in series dictates the effluent performance and, therefore, this number can be selected depending upon the desired total nitrogen removal. Simulation results also revealed that increasing the initial AnAOB biomass fraction from 0.01% to 1.0% had no effect in the steady state nitrogen removal but had an effect in the required time to reach the steady state total nitrogen removal and the maximum biofilm thickness. Modeling results of the third process option showed that increasing the bulk oxygen concentration in the reactor from 0.2 g/m3 to 5 g/m3 linearly increased the steady state total nitrogen removal and reduced the time to reach the maximum biofilm thickness. Beyond 5 g/m3, steady state total nitrogen removal decreased. In addition, simulation results revealed that the thicker biofilm clearly showed a more linear correlation between the increase in bulk oxygen concentration and the increase in the steady state total nitrogen removal within a range of bulk oxygen concentrations. The results showed that RBC performance could be controlled by several process options: the number of reactors in series, initial biomass fraction, the bulk oxygen concentration and the maximum biofilm thickness. The mathematical modeling results for the HFMBR and RBC have shown that both have potential as carriers for nitritation: anammox-coupled biofilms targeted at the removal of nitrogen in the wastewater.
Master of Science
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Wutyi, Naing. "Anthropogenic Waste Management Using Material Flow Analysis Under Data Limited Conditions in Mandalay, Myanmar." Kyoto University, 2019. http://hdl.handle.net/2433/244540.

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Wolfe, Christopher Stuart. "Novel Techniques for Detection and Imaging of Spin Related Phenomena: Towards Sub-Diffraction Limited Resolution." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437316315.

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Sweetman, Paul J. "Evaluating the Fate of Manure Nitrogen in Confined Dairy Waste Operations: a Full-Scale Waste Analysis and Start-Up Protocol for an Anammox-Based Treatment Technology Applicable to Dairy Waste Management." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/41237.

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In an effort to develop cost-effective technologies for the removal of ammonium nitrogen from dairy waste, a novel biological wastewater treatment process, utilizing anaerobic ammonium oxidation (anammox), referred to as Oxygen-Limited Autotrophic Nitrification and Denitrification (OLAND) was examined. Due to the potential use of OLAND-based systems in dairy manure management, a detailed water quality assessment of a modern dairy farm manure treatment-system was conducted. The Johnson Highland Dairy Farm, Glade Spring, Virginia, was selected for this assessment and a comprehensive analysis of the wastewater characteristics throughout the confined animal feeding operation was completed. The results suggest that ammonia concentrations in the anaerobic storage facility was high enough to justify use of treatment technologies that reduce ammonia loads in stored dairy waste. A lightly loaded Fixed Film Bioreactor (FFBR), in which the OLAND process was desired to occur, was then constructed in the laboratory and monitored over 51 days. Of particular interest was the time taken to achieve stable performance of this OLAND system. Furthermore, a protocol was developed to determine whether OLAND based metabolism was occurring. Ammonium nitrogen removal efficiency in the FFBR throughout the 51-day monitoring period was high, averaging approximately 95 % for the length of the study. From day 32 to 51, simultaneous removal of both ammonium and nitrite with a low level of concomitant nitrate production was observed, a key indicator of possible anammox activity. Stoichiometric ratios calculated for the FFBR compared favorably with those already established for OLAND systems. The developed protocol, incorporating anaerobic and aerobic batch experiments, to verify the occurrence of OLAND based metabolism did not yield expected results and described poorly what was being observed in the FFBR. Volatilization of ammonia during the experimental test was suspected and should be controlled when the protocol is performed in the future.
Master of Science
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Malerba, Martino Edoardo. "Extending quota models to nitrogen-limited growth of phytoplankton populations." Thesis, 2015. https://researchonline.jcu.edu.au/46585/1/46585-malerba-2015-thesis.pdf.

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Almost all life on earth is directly or indirectly dependent on phytoplankton primary productivity. In many aquatic systems, phytoplankton primary production is limited by the availability of nitrogen in the environment. Therefore, studying the dynamics of nitrogen uptake and assimilation by phytoplankton cells is critically important for understanding many ecosystem services and global biogeochemical cycles. Mathematical models are particularly powerful tools for analyzing dynamic processes in many areas of ecology, but so far their employment with phytoplankton time-series has been limited. Specifically, published phytoplankton models are unable to explicitly account for the role of different nitrogen forms on cell division and can only be calibrated with time-consuming and impractical monitoring of specific variables. Overall, this thesis aimed to expand previous models by incorporating important processes regulating nitrogen utilization in phytoplankton cells, and by improving their calibration with proxy data routinely monitored in experimental studies. Nitrate and ammonium are the two most important sources of inorganic nitrogen driving phytoplankton primary productivity. The performance of phytoplankton species changes when reared with either of these two forms of nitrogen individually, as well as when they are both present, or when cells have experienced previous periods of nitrogen starvation. However, current functional responses are unable to capture transient and interactive dynamics of nitrate and ammonium uptake, nor can they capture how these two forms of nitrogen differently influence cell division. Hence, in chapter 2, I designed and empirically tested a new process-based model that includes uptake of both nitrate and ammonium, as well as the effects of starvation length and inhibition of nitrate uptake by ammonium on phytoplankton cell division. Results for the green alga Chlorella sp. showed that a single parameterization of the model performed well across data from laboratory cultures started at 12 different initial conditions. This new model allowed for the first time the quantification of nitrate-ammonium utilization traits of a phytoplankton species. This contributes to a more comprehensive understanding of the factors underpinning the high variation in nitrate-ammonium assimilation observed in natural and engineered systems. Characterizing resource utilization traits of a species is particularly important for identifying processes promoting biodiversity and ecosystem functioning in nature. Most trait-based studies define species by their mean trait values and assume intraspecific trait variability to be negligible compared to interspecific differences. However, phenotypic plasticity may be an important source of variation in phytoplankton species, which are well known for their ability to rapidly adjust their cell size according to biotic and abiotic conditions. In chapter 3, I used the model designed in chapter 2 to evaluate the effects of cell size plasticity on the nitrogen utilization traits of the green alga Desmodesmus armatus, reared under different nitrogen sources (nitrate, ammonium, or both) and nitrogen histories (N-replete and N-deplete). Results showed that nitrate-ammonium utilization traits depended substantially on mean cell size and nitrogen history and that representing phytoplankton species by their mean trait values (as per traditional approaches) could underestimate the actual performance of a species by as much as one order of magnitude. These results highlight the ecological importance of intraspecific variability in determining the ability of a species to adjust to new environmental conditions. Biologically, it is well-known that the internal concentration of the most limiting nutrient (cell "quota") is what determines the growth rate of a cell. Given the critical importance of nitrogen for phytoplankton cell division, monitoring nitrogen quota is important to understand aquatic primary productivity, phytoplankton ecology, eutrophication and algal blooms. However, current methods to directly monitor nitrogen quota remain inaccurate, expensive, destructive, and time-consuming. Thus, in chapter 4, I tested the hypothesis that optical changes in single cells, which can be rapidly and accurately monitored with a standard flow cytometer, can provide reliable proxies for per-cell internal nitrogen. Results from four freshwater phytoplankton species showed that cellular nitrogen quota could be estimated accurately (R² = 0.9) from cell optical properties and medium nitrogen, and that the relationship did not change among different species or different initial conditions. In particular, red chlorophyll autofluorescence (from here on simply "red fluorescence") was the most important variable explaining 77% of the total variability in total cell nitrogen. These results indicate that optical flow cytometric variables are a reliable and non-destructive method to estimate nitrogen quota in phytoplankton cells. Finding an efficient proxy to evaluate cell nitrogen quota is particularly valuable for extending the applicability of phytoplankton models. The internal nitrogen status of a cell is critical to analyze the dynamics of nitrogen-limited phytoplankton populations, but accounting for this process in phytoplankton models requires monitoring per-cell nitrogen quota, which is time-consuming, inaccurate, and destructive. Instead, the method I proposed in chapter 4 to quantify nitrogen quota using the optical properties of individual cells is rapid, precise, accurate, and non-destructive. Hence, in chapter 5, I evaluated a new way to model phytoplankton populations, consisting in explicitly including cell optical properties as a proxy for nitrogen quota within phytoplankton Quota models. Results showed that accounting for cell optical properties could improve the performance of phytoplankton population models while still accounting for the biologically important process of cell nitrogen storage. More broadly, these findings highlight the importance of identifying proxy variables for the internal condition of an organism when using population models to analyze species dynamics. The overarching aim of my thesis was to improve current phytoplankton models for the analysis of phytoplankton nitrogen utilization. This was achieved by presenting and calibrating a new mathematical framework describing the dynamics of nitrate-ammonium utilization in phytoplankton populations (chapter 2), by evaluating the effect of mean cell size and previous nitrogen history in determining the nitrogen utilization of a cell (chapter 3), and by documenting the importance of cell optical properties for explaining the dynamics of phytoplankton populations (chapters 4 and 5). These findings improve our ability to identify, analyze, and understand the relationships between nitrogen concentrations in the environment and phytoplankton populations. More broadly, this thesis offers new mathematical tools to better investigate the processes regulating phytoplankton primary productivity in nature and engineered systems.
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Peter, Josephine Jasmine. "Identification of yeast genes enabling efficient oenological fermentation under nitrogen-limited conditions." Thesis, 2018. http://hdl.handle.net/2440/113360.

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Nitrogen deficiency can often lead to slow or sluggish fermentation, resulting in wine out of specification and at risk of oxidation and microbial contamination. Problems due to nitrogen deficiency can be rectified by optimising grape chemistry (through vineyard fertilization), or more commonly supplementing the fermentation with ammonium salts. An alternative is to use wine yeast that can utilize nitrogen efficiently and complete fermentation more reliably. However, to develop ‘nitrogen efficient’ yeast, it is important to understand how such yeast can utilize nitrogen effectively by identifying genes that influence fermentation performance over a range of nitrogen concentrations. Past research related to the identification of genes influencing nitrogen efficiency under fermentative conditions is largely confined to laboratory yeast. Investigation of the ~5,000 non-essential genes in yeast is possible through research tools such as deletion libraries (collections of strains, each with a single gene deletion). Several genomewide studies have successfully used deletion libraries in the auxotrophic background of laboratory yeast to investigate phenotypes in response to exposure to single stress factors associated with fermentation. However, the need to supplement with amino acids to overcome auxotrophies makes quantitative physiological studies in nitrogen limiting conditions impractical. Therefore, in this study, we have used a prototrophic deletion collection in both laboratory and wine yeast backgrounds to identify genes influencing fermentation performance. Screening (micro-fermentation; 600 μL) of the prototrophic laboratory yeast deletion library (BY4741; 5,372 deletants) and the partial wine yeast library (AWRI1631; 1,844 deletants) for growth and consumption of sugar and nitrogen under limiting (75 mg FAN L⁻¹) and non-limiting nitrogen (450 mg FAN L⁻¹) conditions identified deletants with improved fermentation. To better understand the role of individual genes in fermentation, candidate gene sets from each screen were compared to each other and to other published data sets from genome wide transcriptomic analyses related to fermentation. Wine yeast deletants that enabled shortened micro-fermentation duration in low nitrogen conditions were further investigated, since the experiment best represented nitrogen deficient grape must associated with problematic fermentation. Fifteen deletants completed fermentation quicker than the wildtype (c.a. a 15-59% time reduction) when tested in larger (100 mL) fermentations. This group of genes were annotated to biological processes including protein modification, transport, metabolism and ubiquitination (UBC13, MMS2, UBP7, UBI4, BRO1, TPK2, EAR1, MRP17, MFA2 and MVB12), signalling (MFA2) and amino acid metabolism (AAT2). Among the genes identified, MFA2 (mating a-factor), which conferred a 34% decrease in fermentation duration, was further investigated. We were interested to understand how deletion of this mating type gene affected fermentation since a link between these metabolic pathways would be novel. The 15 strains identified in this study, which were fermentation proficient in a ‘wine-like', limited nitrogen condition, provide a basis to better understand how yeast adapt to nitrogen limitation during fermentation. Furthermore, the corresponding genes can be targeted in second generation strain improvement programs, using tools such as CRISPR (yet to be approved by relevant regulatory bodies) to generate nitrogen efficient yeast to reduce the need to supplement low nitrogen fermentations.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Agriculture, Food and Wine, 2018.
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Li, Jian Hong, and 李建泓. "Biosynthesis of PHBV by Burkholderia sp. Yu-4 under a Nitrogen-Limited Condition." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/44989226424799564781.

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碩士
大葉大學
生物產業科技學系
98
Burkholderia sp. Yu-4 was cultured to produce PHAs by using glucose (as the first carbon source) and organic salts (sodium propionate or sodium valerate as the second carbon source) in a nitrogen-limited medium. A one-time-one-factor method was used to explore the effects of types of nitrogen and carbon sources, organic salts and their concentrations on PHBV biosynthesis and to search for optimal conditions for batch fermentation. From the results of one-time-one-factor experiments using various carbon sources (based on the same amount of carbon in glucose) and ammonium sulfate as the nitrogen source in a flask culture, glucose was the best carbon source, and yields of biomass and PHB reached 4.53 and 1.96 g/L, respectively. When Burkholderia sp. Yu-4 was cultured in various nitrogen sources (based on the same amount of nitrogen in ammonium sulfate) and glucose (as the carbon source), ammonium sulfate was the best nitrogen source to yield the highest biomass (4.90 g/L) and PHB (1.63 g/L). If sodium valerate was added as the second carbon source, the best timing was at 6 h to add this salt. For sodium propionate, the biomass and PHBV production reached 6.02 and 2.38 g/L (HB 2.33 g/L and HV 0.05 g/L), respectively. For sodium valerate, the biomass and PHBV production reached 3.95 and 1.76 g/L (HB 1.52 g/L and HV 0.24 g/L), respectively. When the concentration of organic salt was considered as a factor, the results show that the most appropriate concentration for sodium propionate was 1 g/L, and the biomass and PHBV reached 4.95 and 2.09 g/L (HB 1.95 g/L and HV 0.14 g/L), respectively. For sodium valerate, the most appropriate concentration was 4 g/L, the biomass, and PHBV were 4.93 and 1.98 g/L (HB 1.57 g/L and HV 0.41 g/L), respectively. If no organic salt was added, the optimal PHB production reached 3.95 g/L, and the biomass was 6.47 g/L in a batch fermenter.
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Books on the topic "Nitrogen-limited"

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Betts, Edward A. Introduction to enriched air diving: The limited SafeAir users' guide. Freeport, NY: American Nitrox Divers International, 1994.

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Commission, Great Britain: Competition, and Davis Peter. Review of Undertakings Given to the Competition Commission by Kemira Growhow Oyj, Kemira Growhow Holdings Limited, Kemira Growhow UK Limited, Terra Industries Inc and Terra Nitrogen Limited: Final Report. Stationery Office, The, 2012.

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Rāingān kānwičhai phon khō̜ng parimān naitrōčhēn thī chai nai kānphō̜līang sārāi (Isochrysis galbana) tō̜ parimān ʻongprakō̜p thāng khēmī khō̜ng sārāi læ ʻattrā kānčharœ̄ntœ̄ptō ʻattrā kānrō̜t khō̜ng lūk plā Kātūn wai ʻō̜n =: Effects of nitrogen-limited culture microalgae Isochrysis galbana on biochemical composition of microalgae, growth and survival of anemonefish larvae. [Chon Buri]: Sathāban Witthayāsāt Thāng Thalē, Mahāwitthayālai Būraphā, 2007.

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Burdmann, Emmanuel A., and Vivekanad Jha. Rickettsiosis. Edited by Vivekanand Jha. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0193.

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Rickettsiae are obligate intracellular bacteria transmitted by arthropods to a vertebrate host. Clinically relevant rickettsioses have a similar clinical pattern, manifesting as an acute febrile disease accompanied by headache, articular and muscle pain, and malaise.Epidemic typhus is a worldwide distributed disease caused by the Rickettsia prowazekii, with a human louse as a vector. Data on epidemic typhus-related renal injury is extremely scarce.Murine typhus is caused by the Rickettsia typhi and has a rodent flea as the vector. It is one of the most frequent rickettsioses, and is usually a self-limited febrile illness. Proteinuria, haematuria, elevations in serum creatinine (SCr) and/or blood urea nitrogen (BUN) and AKI have been reported. The real frequency of renal involvement in murine typhus is unknown. Renal abnormalities recover after the infectious disease resolution.Scrub typhus, caused by the Orientia tsutsugamushi, has the Leptotrombidium mite larva as vector. It is endemic in the Tsutsugamushi triangle delimited by Japan, Australia, India, and Siberia. It can manifest either as a self-limiting disease or as a severe, life-threatening multiorgan illness. Early administration of adequate antibiotics is essential to prevent adverse outcomes. Proteinuria, haematuria, and acute kidney injury (AKI) are frequent.Tick-borne rickettsioses are caused by bacteria from the spotted fever group and have ticks as vectors. Rocky Mountain spotted fever (RMSF) is caused by Rickettsia rickettsii. It is the most severe of the spotted fever rickettsial diseases, causing significant morbidity and lethality. RMSF occurs in North, Central, and South America. Renal impairment is frequent in severe forms of RMSF. Mediterranean spotted fever is caused by Rickettsia conorii, and is endemic in the Mediterranean area. It is usually a benign disease, but may have a severe course, clinically similar to RMSF. Haematuria, proteinuria, increased serum creatinine, and AKI may occur. Japanese spotted fever is caused by Rickettsia japonica. Lethal cases are reported yearly and AKI has occurred in the context of multiple organ failure.
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Myer, Phillip, and Liesel Schneider, eds. Tiny Microbes, Big Yields: The Future of Food and Agriculture. Frontiers Media SA, 2022. http://dx.doi.org/10.3389/978-2-88974-951-5.

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Our world is made up of countless tiny living beings. There are so many of them, that they make up the largest number of living beings on the planet. These microscopic organisms, called microorganisms or microbes, cannot be seen with the naked eye. We encounter them daily and we interact with them through the air we breathe, the food we eat, and the natural processes within our own organ systems. Microbes have evolved with life on Earth to be important for its survival. They act as food for plants and animals, help humans and animals digest food, break down dead material, and even serve as guardians against bad microbes. Whether we realize it or not, humans rely on microbes to help make the food we eat every day, and understanding how they work helps us to improve our foods and agriculture. It is amazing to examine how well microorganisms are incorporated into the food we eat, the plants we grow, and the animals we raise. Microbes help ferment foods to make products like cheeses and breads. They work in the soil to provide nitrogen to plants which helps them grow better. Special microbes live in the stomachs of cattle and sheep that allow them to digest grasses that humans cannot eat. Additionally, the energy produced from the microbial digestion of these grasses helps produce meat and milk. However, as with everything, we must take the good with the bad. Although many microbes are helpful, some are harmful and can cause illness. These “bad bugs” must be monitored to ensure they do not enter our food supply. The challenge is to interpret the ways the microbes are positively and negatively impacting food and agriculture and to untangle their complex network to promote improved and more efficient approaches to feed the world. This collection of articles focuses on understanding more about microbial communities, biodiversity, and their relationships with food and agriculture. This includes, but is not limited to, food and animal production, animal health, food safety, crop safety and production, and agricultural sustainability through microbial-based approaches. What we can learn about these tiny living beings can help provide safe, nutritious, and sustainable food to a growing human global population.
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Book chapters on the topic "Nitrogen-limited"

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Tamm, Carl Olof. "Nitrogen-Limited and Nitrogen-Depleted Terrestrial Ecosystems: Ecological Characteristics." In Nitrogen in Terrestrial Ecosystems, 34–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-75168-4_3.

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Duarte, Paulo, Petter Oscarson, Jan-Eric Tillberg, and Carl-Magnus Larsson. "Nitrogen and carbon utilization in shoots and roots of nitrogen-limited Pisum." In Structural and Functional Aspects of Transport in Roots, 199–202. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0891-8_37.

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Burns, I. G., M. A. Escobar-Gutierrez, and A. J. Broadley. "A role for stomatal conductance in nitrogen-limited growth?" In Plant Nutrition, 104–5. Dordrecht: Springer Netherlands, 2001. http://dx.doi.org/10.1007/0-306-47624-x_49.

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Mattsson, M., M. Larsson, T. Lundborg, and C. M. Larsson. "Uptake and partitioning of nitrogen in nitrogen-limited barley: Dependence of age and genotype." In Genetic Aspects of Plant Mineral Nutrition, 39–43. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-2053-8_6.

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Crăciun, I., and M. Crăciun. "Water and nitrogen use efficiency under limited water supply for maize to increase land productivity." In Crop Yield Response to Deficit Irrigation, 87–94. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-011-4752-1_6.

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Addiscott, T. M., N. J. Bailey, G. J. Bland, and A. P. Whitmore. "Simulation of nitrogen in soil and winter wheat crops: a management model that makes the best use of limited information." In Nitrogen Turnover in the Soil-Crop System, 305–12. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3434-7_15.

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Egli, Thomas. "On multiple-nutrient-limited growth of microorganisms, with special reference to dual limitation by carbon and nitrogen substrates." In Quantitative Aspects of Growth and Metabolism of Microorganisms, 225–34. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2446-1_8.

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Findenegg, G. R. "Effect of varied shoot/root ratio on growth of maize (Zea mays) under nitrogen-limited conditions: Growth experiment and model calculations." In Plant Nutrition — Physiology and Applications, 21–27. Dordrecht: Springer Netherlands, 1990. http://dx.doi.org/10.1007/978-94-009-0585-6_4.

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Pierrard, J., J. C. Willison, and P. M. Vignais. "Factors Involved in Selection of Nif- Mutants in N-Limited Cultures of the Photosynthetic Bacterium Rhodobacter capsulatus." In Nitrogen Fixation, 575–76. Dordrecht: Springer Netherlands, 1991. http://dx.doi.org/10.1007/978-94-011-3486-6_128.

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Wu, Lianhai, and K. Christian Kersebaum. "Modeling Water and Nitrogen Interaction Responses and Their Consequences in Crop Models." In Response of Crops to Limited Water, 215–49. Madison, WI, USA: American Society of Agronomy and Soil Science Society of America, 2015. http://dx.doi.org/10.2134/advagricsystmodel1.c8.

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Conference papers on the topic "Nitrogen-limited"

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Haladu, Zangoma Maryam, Izyanti Ibrahim, and Aidil Abdul Hamid. "The significance of nitrogen limited condition in the initiation of lipid biosynthesis in Aurantiochytrium sp. SW1." In THE 2017 UKM FST POSTGRADUATE COLLOQUIUM: Proceedings of the University Kebangsaan Malaysia, Faculty of Science and Technology 2017 Postgraduate Colloquium. Author(s), 2018. http://dx.doi.org/10.1063/1.5027996.

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Daily, Joseph V. "Mobile Nitrogen Pumper: A Valuable Tool." In ASME 2004 Power Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/power2004-52168.

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This paper describes a unique piece of equipment for delivering nitrogen gas. This equipment is used for supplying nitrogen on a temporary basis and capable of delivering an extremely wide range of pressure, flow, and temperature requirements. In the electric utility industry, “temporary nitrogen supply” has been mostly associated with the use of banks of pressurized cylinders or tube trailers. Both have definite limitations with overall volume capacity and flow rates. These delivery systems tend to be time consuming, require multiple refill deliveries, and lack cost effectiveness. The general awareness of the existence of mobile nitrogen pumping equipment and the potential value it provides is relatively limited within the electric power industry. Recently, however, this equipment has been used successfully as a cost saving alternative for selected applications. One such example is to replace natural gas for fuel line blow cleaning and “target testing” during the construction phase of natural gas fired combustion turbines. The mobile nitrogen pumping equipment effectively duplicates the flow and sonic velocities achieved using natural gas while conforming to the established “target testing” specifications. The primary benefits of using nitrogen in lieu of natural gas or air are cited to be enhanced safety, environmental considerations, and overall time/cost savings. A description of this equipment is offered including the flow rate, pressure, and temperature specifications. Additionally, examples are given of a program that predicts nitrogen gas velocities throughout the natural gas delivery piping system under steady flow conditions. This includes velocity changes as the piping system diameter changes. Specific data is offered comparing the velocity differences between natural gas and nitrogen under the same steady state flow rate conditions. Case studies are offered that detail the successful use of this mobile nitrogen pumping equipment for line blowing and “target testing” during the pre startup phase of combined cycle plants.
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Hella, Abdullah, Mohamed Al-Ajmi, and Sherif Abdelrahman. "State of the Art Membrane Nitrogen Technology Enables Remote and Large-Volume Pipeline Leak Testing." In International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-22367-ea.

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Abstract The paper presents a case study of applying Membrane Nitrogen technology in purging a 600 km long pipeline in Saudi Arabia for pressure testing purposes. The paper will cover the operational advantages and superiority that comes with using Membrane Nitrogen Technology compared to using Cryogenic Liquid Nitrogen. Besides that, potential applications for the technology in remote projects requiring large volumes of Nitrogen will be covered in the paper. The paper will explain in full detail the Membrane Nitrogen technology along with elaborating how the process works at remote sites. In addition, comprehensive elaboration of several aspects of the technology are discussed; including but not limited to quality of Nitrogen generated, injection rate capacity, injection pressure and the process flow diagram. The paper also examines how this technology eliminates the logistical challenges and ensures maximum efficiency at the job site.
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Morini, Mirko, Michele Pinelli, Pier Ruggero Spina, and Anna Vaccari. "An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part III — Computational Fluid Dynamic Analysis of Syngas Combustion in Nitrogen-Enriched Air." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-94094.

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In recent years, an innovative system for power augmentation has been presented by the authors. The system is based on gas turbine inlet air cooling by means of liquid nitrogen sprayers. This system is not characterized by the limits of water evaporative cooling (i.e. lower temperature limited by air saturation) and refrigeration cooling (i.e. effectiveness limited by pressure drop in the heat exchangers), but the injection of a large amount of liquid nitrogen at gas turbine inlet section can be disputable. In fact, the air composition changes, though not considerably, after nitrogen injection. The oxygen content always seems high enough to allow a regular combustion. In any case, local effects should be further investigated. In this paper, the effect of the increase in nitrogen molar fraction of combustion air is evaluated. A micro gas turbine combustion chamber geometry (i.e. a reverse flow tubular combustor) is taken into consideration since its model has been widely validated by the authors. The analyses are performed by considering two different fuels: methane (which is the design fuel) and syngas. The results are compared in terms of overall performance (e.g. TIT, pollutant emissions) and local distributions (e.g. flow fields, flame shape and position).
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Gilleaudeau, Geoffrey J., Christopher K. Junium, Linda C. Kah, Natasha Zolotova, and Ariel D. Anbar. "NO EVIDENCE FOR ALTERNATIVE NITROGENASE EXPRESSION IN A MESOPROTEROZOIC MOLYBDENUM-LIMITED ENVIRONMENT: CONSTRAINTS FROM NITROGEN ISOTOPES AT 1.1 GA." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-296732.

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Overcamp, Thomas J., Ajay K. Agrawal, Wei-Seng Cheng, and Tah-Teh Yang. "Calculations of Fuel NO Formation in a Gas Turbine Combustor." In ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/91-gt-361.

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PCGC-2, a two-dimensional combustion code for pulverized coal gasification and combustion, and PHOENICS, a general purpose fluid dynamics code, were adapted for use in simulating the conversion of fuel nitrogen to nitric oxide, NO, in a gas turbine combustor using low-Btu fuel. A two-reaction global mechanism was used to describe the oxidation of fuel nitrogen. PCGC-2 is limited to two-dimensional, axisymmetric calculations. Both two- and three-dimensional simulations were made with PHOENICS. A parametric study was conducted to determine the variation of fuel nitrogen conversion with changes in the input variables including the inlet fuel nitrogen concentration and swirl numbers. The fuel nitrogen conversion predicted with both codes is similar to those reported in experimental studies on gaseous fuels. The conversion decreased with increasing fuel nitrogen inputs as shown in experimental data. The fuel conversion predicted in three-dimensional simulations for an industrial gas turbine was slightly higher than those in simplified two-dimensional simulations.
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Biruduganti, Munidhar S., Sreenath B. Gupta, Steven McConnell, and Raj Sekar. "Nitrogen Enriched Combustion of a Natural Gas Engine to Reduce NOx Emissions." In ASME 2004 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/icef2004-0843.

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Nitrogen enrichment of intake air is proposed as an alternative to Exhaust Gas Recirculation (EGR). Experimental results of nitrogen enriched combustion of a Kohler M12 engine (converted to operate with natural gas) are presented in this paper. A 70% reduction in NOx emissions was observed at full load (4 kW) and ignition timing (IT) equal to −20 ATDC with 2.1% NO2 enrichment (40 slpm). However, NOx reduction was minimal at lower loads. The effect of spark or ignition timing along with nitrogen enrichment is also reported for full load. It is recognized that advancing the ignition timing from conventional values has more advantages than retarding the same. A 68% reduction in NOx and a 0.8% drop in Fuel Conversion Efficiency (FCE) were observed at −30 ATDC ignition timing. However, the maximum ignition timing advance with stable engine operation was limited to −40 ATDC. Some of the drawbacks encountered were engine misfire at higher concentrations of nitrogen-rich air and retarded spark timing resulting in poor FCE.
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Morini, Mirko, Michele Pinelli, and Pier Ruggero Spina. "An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part II—Thermodynamic Analysis." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68352.

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Integrated Gasification Combined Cycles (IGCCs) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, the plant also has an Air Separation Unit (ASU). Moreover, a producer gas cleaner unit is always present between the gasifier and the gas turbine. Since these plants are based on gas-steam combined cycle power plants they suffer from a reduction in performance when ambient temperature increases. In this paper, an innovative system for power augmentation in IGCC plants is presented. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first chilled and liquefied and then it can be used for inlet air cooling or stored for a postponed use. This system is not characterized by the limits of water evaporative cooling (where the lower temperature is limited by air saturation) and refrigeration cooling (where the effectiveness is limited by pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for the simulation of energy conversion systems. A sensitivity analysis on the main parameters (e.g. ambient air temperature, inlet air temperature difference, etc.) is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year.
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Foster, T. J., and C. W. Wilson. "Detailed Chemical Modelling Predictions of Emissions From a Reheated Gas Turbine Engine With Application to Future Supersonic Aircraft." In ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-gt-370.

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The exhaust plumes of modern gas turbine engines are of great concern due to the emission of atmospheric pollutants, such as carbon monoxide, unburnt hydrocarbons and oxides of nitrogen (NOx) and visibility caused by the presence of black carbonaceous smoke and nitrogen dioxide (NO2) giving rise to a new plume visibility phenomena of “yellow smoke”. A detailed hydrocarbon oxidation and NOx scheme was used to simulate chemical reactions occurring through the gas turbine engine and near-field plume. In addition limited experimental measurements have been made directly behind a reheated gas turbine engine to measure gaseous emissions and to quantify the rate of conversion of nitric oxide to nitrogen dioxide. Two experimental methods were employed to measure emissions; the first a conventional probe technique, the second a non-intrusive method. Results show a fair agreement between experimental data and predicted emissions, showing the maximum conversion of NO to NO2 at low reheat fuel flowrates. These detailed results can be used as an input to atmospheric modelling codes.
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Siegel, Jason B., Anna G. Stefanopoulou, and Serhat Yesilyurt. "Modeling and Experiments of Voltage Transients of PEM Fuel Cells With the Dead-Ended Anode." In ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology collocated with ASME 2011 5th International Conference on Energy Sustainability. ASMEDC, 2011. http://dx.doi.org/10.1115/fuelcell2011-54768.

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The operation of PEM fuel cells (PEMFC) with dead-ended anode (DEA) leads to severe voltage transients due to accumulation of nitrogen, water vapor and liquid water in the anode channels and the gas diffusion layer (GDL). Accumulation of nitrogen causes a large voltage transient with a characteristic profile whereas the amount of water vapor in the anode is limited by the saturation pressure, and the liquid water takes up very small volume at the bottom of the anode channels in the case of downward orientation of the gravity. Here, we present a transient 1D along-the-channel model of PEMFCs operating with periodically-purged DEA channels. In the model, transport of species is modeled by the Maxwell-Stefan equations coupled with constraint equations for the cell voltage. A simple resistance model is used for the membrane to express the permeance of nitrogen and transport of water through the membrane. The model results agree very well with experimental results for the voltage transients of the PEMFC operating with DEA. In order to emphasize the effect of nitrogen accumulation in the anode, we present experimentally obtained cell voltage measurements during DEA transients, when the cathode is supplied with pure oxygen. In the absence of nitrogen in the cathode, voltage remained almost constant throughout the transient. Then, the model is used to determine the effect of oxygen-to-nitrogen feed ratio in the cathode on the voltage transient behavior for different load currents. Lastly, the model is used to show the effect of the small amount of leak from the anode exit on the voltage transient; even for leak rates as low as less than 10 ml/h, nitrogen accumulation in the anode channels is alleviated and the cell voltage remained almost constant throughout the transient.
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Reports on the topic "Nitrogen-limited"

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Groenendijk, Piet, Hendrik Boogaard, Marius Heinen, J. G. Kroes, Iwan Supit, and Allard de Wit. Simulation nitrogen-limited crop growth with SWAP/WOFOST : process descriptions and user manual. Wageningen: Wageningen Environmental Research, 2016. http://dx.doi.org/10.18174/400458.

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Zhu, Yi-Bing, Yan Yao, Yuan Xu, and Hui-Bin Huang. Nitrogen balance and Outcomes in Critically Ill Patients: A Systematic Review and Meta-Analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, May 2022. http://dx.doi.org/10.37766/inplasy2022.5.0134.

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Review question / Objective: This study aimed to evaluate the impact of Nitrogen balance (NB) on prognosis in such a patient population. Condition being studied: Nitrogen balance and Outcomes in Critically Ill Patients. Eligibility criteria: 1) The study focused on the association between NB level and the mortality risk in adult (≥18 years old) patients; 2) The outcome data included any reporting form of survival data that could be extracted; and 3) The study design was limited to cohort, case-control, or RCT design.
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Kudin, Roman, Prabhat Chand, and Anura Bakmeedeniya. Mitigating Nitrogen Oxides Exhaust Emissions from Petrol Vehicles by Application of a Fuel Additive. Unitec ePress, August 2020. http://dx.doi.org/10.34074/rsrp.083.

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This research has been commissioned by Eco Fuel Global Limited, a New Zealand-based company, to further evaluate the effects of their fuel-additive product on the tailpipe exhaust emissions of petrol cars. At the time this research was conducted (end of 2018), the product was still in development and had not been released to the market. Prior to the testing in this research, an initial pilot test was done for the same product on a single car (Nissan Pulsar 1998), which showed favourable results, with a reduction in hydrocarbons and oxides of nitrogen at the tailpipe by more than 70%. The current research included five test cars, all running on RON 95 fuel, with the years of manufacture ranging between 1994 and 2006, and the odometer readings between 112,004 km and 264,001 km. The effects of the fuel-additive product were assessed by comparing the emissions from a car running on standard fuel with the emissions from the same car after it completed a road run (250±20 km) on the additive-treated fuel. The exhaust emissions were measured using the AVL series 4000 Emission Tester, which analyses five components: carbon monoxide (CO), carbon dioxide (CO2), oxides of nitrogen (NOX), hydrocarbons (HC) and oxygen (O2). The most noticeable outcome of using the fuel-additive product was the reduction in the concentration of oxides of nitrogen in the tailpipe exhaust (by up to 27.7%), when compared with the same cars running on standard fuel. In addition, the results showed a decrease in residual oxygen concentration, which normally indicates more complete utilisation of O2 as an oxidising agent. Mitigating Nitrogen Oxides Exhaust Emissions from Petrol Vehicles by Application of a Fuel Additive Dr Roman Kudin, Prabhat Chand and Anura Bakmeedeniya 2 The changes for other emission parameters were either relatively small (below 1%) or were not statistically significant. The application of such fuel-additive products could be beneficial for mitigating nitrogen oxides exhaust emissions from petrol vehicles in countries with ageing car fleets. These include New Zealand, which has a relatively high proportion of old cars in use, with no government-run scrappage scheme, and without a mandatory objective emissions testing.
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Kolodziejczyk, Bart. Unsettled Issues Concerning the Use of Green Ammonia Fuel in Ground Vehicles. SAE International, February 2021. http://dx.doi.org/10.4271/epr2021003.

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While hydrogen is emerging as a clean alternative automotive fuel and energy storage medium, there are still numerous challenges to implementation, such as the economy of hydrogen production and deployment, expensive storage materials, energy intensive compression or liquefaction processes, and limited trial applications. Synthetic ammonia production, on the other hand, has been available on an industrial scale for nearly a century. Ammonia is one of the most-traded commodities globally and the second most-produced synthetic chemical after sulfuric acid. As an energy carrier, it enables effective hydrogen storage in chemical form by binding hydrogen atoms to atmospheric nitrogen. While ammonia as a fuel is still in its infancy, its unique properties render it as a potentially viable candidate for decarbonizing the automotive industry. Yet, lack of regulation and standards for automotive applications, technology readiness, and reliance on natural gas for both hydrogen feedstocks to generate the ammonia and facilitate hydrogen and nitrogen conversion into liquid ammonia add extra uncertainty to use scenarios. Unsettled Issues Concerning the Use of Green Ammonia Fuel in Ground Vehicles brings together collected knowledge on current and future prospects for the application of ammonia in ground vehicles, including the technological and regulatory challenges for this new type of clean fuel.
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Banin, Amos, Joseph Stucki, and Joel Kostka. Redox Processes in Soils Irrigated with Reclaimed Sewage Effluents: Field Cycles and Basic Mechanism. United States Department of Agriculture, July 2004. http://dx.doi.org/10.32747/2004.7695870.bard.

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The overall objectives of the project were: (a) To measure and study in situ the effect of irrigation with reclaimed sewage effluents on redox processes and related chemical dynamics in soil profiles of agricultural fields. (b) To study under controlled conditions the kinetics and equilibrium states of selected processes that affect redox conditions in field soils or that are effected by them. Specifically, these include the effects on heavy metals sorption and desorption, and the effect on pesticide degradation. On the basis of the initial results from the field study, increased effort was devoted to clarifying and quantifying the effects of plants and water regime on the soil's redox potential while the study of heavy metals sorption was limited. The use of reclaimed sewage effluents as agricultural irrigation water is increasing at a significant rate. The relatively high levels of suspended and, especially, dissolved organic matter and nitrogen in effluents may affect the redox regime in field soils irrigated with them. In turn, the changes in redox regime may affect, among other parameters, the organic matter and nitrogen dynamics of the root zone and trace organic decomposition processes. Detailed data of the redox potential regime in field plots is lacking, and the detailed mechanisms of its control are obscure and not quantified. The study established the feasibility of long-term, non-disturbing monitoring of redox potential regime in field soils. This may enable to manage soil redox under conditions of continued inputs of wastewater. The importance of controlling the degree of wastewater treatment, particularly of adding ultrafiltration steps and/or tertiary treatment, may be assessed based on these and similar results. Low redox potential was measured in a field site (Site A, KibutzGivat Brenner), that has been irrigated with effluents for 30 years and was used for 15 years for continuous commercial sod production. A permanently reduced horizon (Time weighted averaged pe= 0.33±3.0) was found in this site at the 15 cm depth throughout the measurement period of 10 months. A drastic cultivation intervention, involving prolonged drying and deep plowing operations may be required to reclaim such soils. Site B, characterized by a loamy texture, irrigated with tap water for about 20 years was oxidized (Time weighted average pe=8.1±1.0) throughout the measurement period. Iron in the solid phases of the Givat Brenner soils is chemically-reduced by irrigation. Reduced Fe in these soils causes a change in reactivity toward the pesticide oxamyl, which has been determined to be both cytotoxic and genotoxic to mammalian cells. Reaction of oxamyl with reduced-Fe clay minerals dramatically decreases its cytotoxicity and genotoxicity to mammalian cells. Some other pesticides are affected in the same manner, whereas others are affected in the opposite direction (become more cyto- and genotoxic). Iron-reducing bacteria (FeRB) are abundant in the Givat Brenner soils. FeRB are capable of coupling the oxidation of small molecular weight carbon compounds (fermentation products) to the respiration of iron under anoxic conditions, such as those that occur under flooded soil conditions. FeRB from these soils utilize a variety of Fe forms, including Fe-containing clay minerals, as the sole electron acceptor. Daily cycles of the soil redox potential were discovered and documented in controlled-conditions lysimeter experiments. In the oxic range (pe=12-8) soil redox potential cycling is attributed to the effect of the daily temperature cycle on the equilibrium constant of the oxygenation reaction of H⁺ to form H₂O, and is observed under both effluent and freshwater irrigation. The presence of plants affects considerably the redox potential regime of soils. Redox potential cycling coupled to the irrigation cycles is observed when the soil becomes anoxic and the redox potential is controlled by the Fe(III)/Fe(II) redox couple. This is particularly seen when plants are grown. Re-oxidation of the soil after soil drying at the end of an irrigation cycle is affected to some degree by the water quality. Surprisingly, the results suggest that under certain conditions recovery is less pronounced in the freshwater irrigated soils.
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Bonfil, David J., Daniel S. Long, and Yafit Cohen. Remote Sensing of Crop Physiological Parameters for Improved Nitrogen Management in Semi-Arid Wheat Production Systems. United States Department of Agriculture, January 2008. http://dx.doi.org/10.32747/2008.7696531.bard.

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To reduce financial risk and N losses to the environment, fertilization methods are needed that improve NUE and increase the quality of wheat. In the literature, ample attention is given to grid-based and zone-based soil testing to determine the soil N available early in the growing season. Plus, information is available on in-season N topdressing applications as a means of improving GPC. However, the vast majority of research has focused on wheat that is grown under N limiting conditions in sub-humid regions and irrigated fields. Less attention has been given to wheat in dryland that is water limited. The objectives of this study were to: (1) determine accuracy in determining GPC of HRSW in Israel and SWWW in Oregon using on-combine optical sensors under field conditions; (2) develop a quantitative relationship between image spectral reflectance and effective crop physiological parameters; (3) develop an operational precision N management procedure that combines variable-rate N recommendations at planting as derived from maps of grain yield, GPC, and test weight; and at mid-season as derived from quantitative relationships, remote sensing, and the DSS; and (4) address the economic and technology-transfer aspects of producers’ needs. Results from the research suggest that optical sensing and the DSS can be used for estimating the N status of dryland wheat and deciding whether additional N is needed to improve GPC. Significant findings include: 1. In-line NIR reflectance spectroscopy can be used to rapidly and accurately (SEP <5.0 mg g⁻¹) measure GPC of a grain stream conveyed by an auger. 2. On-combine NIR spectroscopy can be used to accurately estimate (R² < 0.88) grain test weight across fields. 3. Precision N management based on N removal increases GPC, grain yield, and profitability in rainfed wheat. 4. Hyperspectral SI and partial least squares (PLS) models have excellent potential for estimation of biomass, and water and N contents of wheat. 5. A novel heading index can be used to monitor spike emergence of wheat with classification accuracy between 53 and 83%. 6. Index MCARI/MTVI2 promises to improve remote sensing of wheat N status where water- not soil N fertility, is the main driver of plant growth. Important features include: (a) computable from commercial aerospace imagery that include the red edge waveband, (b) sensitive to Chl and resistant to variation in crop biomass, and (c) accommodates variation in soil reflectance. Findings #1 and #2 above enable growers to further implement an efficient, low cost PNM approach using commercially available on-combine optical sensors. Finding #3 suggests that profit opportunities may exist from PNM based on information from on-combine sensing and aerospace remote sensing. Finding #4, with its emphasis on data retrieval and accuracy, enhances the potential usefulness of a DSS as a tool for field crop management. Finding #5 enables land managers to use a DSS to ascertain at mid-season whether a wheat crop should be harvested for grain or forage. Finding #6a expands potential commercial opportunities of MS imagery and thus has special importance to a majority of aerospace imaging firms specializing in the acquisition and utilization of these data. Finding #6b on index MCARI/MVTI2 has great potential to expand use of ground-based sensing and in-season N management to millions of hectares of land in semiarid environments where water- not N, is the main determinant of grain yield. Finding #6c demonstrates that MCARI/MTVI2 may alleviate the requirement of multiple N-rich reference strips to account for soil differences within farm fields. This simplicity will be less demanding of grower resources, promising substantially greater acceptance of sensing technologies for in-season N management.
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Prusky, Dov, Nancy P. Keller, and Amir Sherman. global regulation of mycotoxin accumulation during pathogenicity of Penicillium expansum in postharvest fruits. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7600012.bard.

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Background to the topic- Penicilliumas a postharvest pathogen and producer of the mycotoxin PAT. Penicilliumspp. are destructive phytopathogens, capable of causing decay in many deciduous fruits, during postharvest handling and storage; and the resulting losses can amount to 10% of the stored produce and the accumulation of large amounts of the mycotoxinpatulin. The overall goal of this proposal is to identify critical host and pathogen factors that modulate P. expansummycotoxin genes and pathways which are required for PAT production and virulence. Our preliminary results indicated that gluconic acid are strongly affecting patulin accumulation during colonization. P. expansumacidifies apple fruit tissue during colonization in part through secretion of gluconic acid (GLA). Several publications suggested that GLA accumulation is an essential factor in P. expansumpathogenicity. Furthermore, down regulation of GOX2 significantly reduced PAT accumulation and pathogenicity. PAT is a polyketide and its biosynthesis pathway includes a 15-gene cluster. LaeA is a global regulator of mycotoxin synthesis. It is now known that patulin synthesis might be subjected to LaeA and sometimes by environmental sensing global regulatory factors including the carbon catabolite repressor CreA as well as the pH regulator factor PacC and nitrogen regulator AreA. The mechanisms by which LaeA regulates patulin synthesis was not fully known and was part of our work. Furthermore, the regulatory system that controls gene expression in accordance with ambient pH was also included in our work. PacC protein is in an inactive conformation and is unable to bind to the promoter sites of the target genes; however, under alkaline growth conditions activated PacC acts as both an activator of alkaline-expressed genes and a repressor of acid-expressed genes. The aims of the project- This project aims to provide new insights on the roles of LaeA and PacC and their signaling pathways that lead to GLA and PAT biosynthesis and pathogenicity on the host. Specifically, our specific aims were: i) To elucidate the mechanism of pH-controlled regulation of GLA and PAT, and their contribution to pathogenesis of P. expansum. We are interested to understanding how pH and/or GLA impact/s under PacC regulation affect PAT production and pathogenesis. ii) To characterize the role of LaeA, the global regulator of mycotoxin production, and its effect on PAT and PacC activity. iii) To identify the signaling pathways leading to GLA and PAT synthesis. Using state- of-the-art RNAseq technologies, we will interrogate the transcriptomes of laeAand pacCmutants, to identify the common signaling pathways regulating synthesis of both GLA and PAT. Major conclusions, solutions, achievements- In our first Aim our results demonstrated that ammonia secreted at the leading edge of the fungal colony induced transcript activation of the global pH modulator PacC and PAT accumulation in the presence of GLA. We assessed these parameters by: (i) direct exogenous treatment of P. expansumgrowing on solid medium; (ii) direct exogenous treatment on colonized apple tissue; (iii) growth under self-ammonia production conditions with limited carbon; and (iv) analysis of the transcriptional response to ammonia of the PAT biosynthesis cluster. Ammonia induced PAT accumulation concurrently with the transcript activation of pacCand PAT biosynthesis cluster genes, indicating the regulatory effect of ammonia on pacCtranscript expression under acidic conditions. Transcriptomic analysis of pH regulated processes showed that important genes and BARD Report - Project 4773 Page 2 of 10 functionalities of P. expansumwere controlled by environmental pH. The differential expression patterns of genes belonging to the same gene family suggest that genes were selectively activated according to their optimal environmental conditions to enable the fungus to cope with varying conditions and to make optimal use of available enzymes. Concerning the second and third Aims, we demonstrated that LaeA regulates several secondary metabolite genes, including the PAT gene cluster and concomitant PAT synthesis invitro. Virulence studies of ΔlaeAmutants of two geographically distant P. expansumisolates (Pe-21 from Israel and Pe-T01 from China) showed differential reduction in disease severity in freshly harvested fruit ranging from no reduction for Ch-Pe-T01 strains in immature fruit to 15–25% reduction for both strains in mature fruit, with the ΔlaeAstrains of Is-Pe-21 always showing a greater loss in virulence. Results suggest the importance of LaeA regulation of PAT and other secondary metabolites on pathogenicity. Our work also characterized for the first time the role of sucrose, a key nutritional factor present in apple fruit, as a negative regulator of laeAexpression and consequent PAT production in vitro. This is the first report of sugar regulation of laeAexpression, suggesting that its expression may be subject to catabolite repression by CreA. Some, but not all of the 54 secondary metabolite backbone genes in the P. expansumgenome, including the PAT polyketide backbone gene, were found to be regulated by LaeA. Together, these findings enable for the first time a straight analysis of a host factor that potentially activates laeAand subsequent PAT synthesis.
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