Download or read book Nitrogen Isotope Analysis of Ammonium and Glycine written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable isotope techniques can be used as a tool in nitrogen cycling studies of different ecosystems. The studies are based on measurement of the heavy (15N)- to- light (14N) isotopic ratios of nitrogen in different biospheric pools. Isotope ratio mass spectrometry (IRMS) is the most precise technique to use for analysis of nitrogen isotopic ratios. This thesis deals with the development of methods for compound-specific nitrogen isotope analysis of ammonium and glycine in aqueous solutions and soil extracts using Gas Chromatography - Combustion (GC-C) - IRMS. For ammonium, three different techniques were developed: equilibrium headspace analysis, solid phase microextraction (SPME) and the purge and trap (P & T) technique, which were all based on conversion of ammonium to ammonia with subsequent separation of ammonia for analysis. In the SPME and P & T approaches, custom-made absorbents were used for pre-concentration, followed by thermal desorption into the GC-C-IRMS system. For the equilibrium headspace technique, high precision measurements of the nitrogen isotopic ratio were obtained for concentrations above 420 mg N L-1. With further improvements and the use of suitable equipment, the method has the potential to be used for solutions containing ammonium in the low mg N L-1 range. The SPME technique increased the sensitivity by a factor of » 3 compared to the headspace technique, but was less precise. In addition, the NafionÒ material used for absorption showed a memory effect in the desorption step. With the P & T technique a large variation in the measured isotopic value was observed (using solutions containing 2 mg N L-1) which was due to a non-quantitative thermal desorption. However, with further improvements, the P & T technique has the potential to be used for samples containing below 1.0 µg N, which is a much lower amount than that possible with any method used today. A method for determination of the nitrogen isotopic ratio in free glycine in soil extract

Download or read book Nitrogen Isotope Analysis of Ammonium and Glycine written by Elin Norlin and published by . This book was released on 2005 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Innovative Methods for Ammonium and Amino Acid Natural Nitrogen Isotope Ratio Determination written by Lin Zhang and published by . This book was released on 2007 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Data Relating to the Separation of the Nitrogen Isotopes by the Exchange Reaction Between Ammonia and Solutions of Ammonium Nitrate written by Isidor Kirshenbaum and published by . This book was released on 1946 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Principles of Perinatal Neonatal Metabolism written by Richard M. Cowett and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last quarter century or so, specialization within obstetrics and gynecology, and pediatrics has resulted in the development of the disciplines of maternal-fetal medicine and neonatology, respectively. A primary focus of maternal-fetal medicine has been to understand the mechanism(s) of premature delivery and develop treatment modalities for improving the length of gestation. A primary focus of neonatology has been to under stand the causes of respiratory distress in the neonate. Success has resulted, not only in the lengthening of gestation, but an improved understanding of the causes and treatment of neonatal respiratory disease. With increasing success has come the necessity to under stand the metabolic principles of the parturient, the fetal/placenta unit, and the neonate. These principles are clearly very important from multiple aspects. Increased understand ing of metabolism of the pregnant woman would explain the aberrations occurring in normal and abnormal pregnancy and improve nutritional support for the parturient. A prime example of altered metabolism is the parturient with diabetes. Understanding metabolism ofthe fetal/placenta unit is necessary to increase the probability that the fetus will be born appropriate for size irrespective of the gestational age. The various compo nents of neonatal metabolism are important, not only for understanding the changes in physiology and biochemistry occurring in the developing neonate, but the principles by which nutritional support should be provided.

Download or read book Supplement to the United States Naval Medical Bulletin on Preparation and Measurement of Isotopes and Some of Their Medical Aspects written by Louis Harry Roddis and published by . This book was released on 1948 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book United States Naval Medical Bulletin written by and published by . This book was released on 1948 with total page 1292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Antarctic Journal of the United States written by and published by . This book was released on 1990 with total page 1454 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plant Microbe Symbiosis written by Ajit Varma and published by Springer Nature. This book was released on 2020-04-01 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an overview of the latest advances concerning symbiotic relationships between plants and microbes, and their applications in plant productivity and agricultural sustainability. Symbiosis is a living phenomenon including dynamic variations in the genome, metabolism and signaling network, and adopting a multidirectional perspective on their interactions is required when studying symbiotic organisms. Although various plant-microbe symbiotic systems are covered in this book, it especially focuses on arbuscular mycorrhiza (AM) symbiosis and root nodule symbiosis, the two most prevalent systems. AM symbiosis involves the most extensive interaction between plants and microbes, in the context of phylogeny and ecology. As more than 90% of all known species of plants have the potential to form mycorrhizal associations, the productivity and species composition, as well as the diversity of natural ecosystems, are frequently dependent upon the presence and activity of mycorrhizas. In turn, root nodule symbiosis includes morphogenesis and is formed by communication between plants and nitrogen-fixing bacteria. The biotechnological application of plant–microbe symbiosis is expected to foster the production of agricultural and horticultural products while maintaining ecologically and economically sustainable production systems. Designed as a hands-on guide, this book offers an essential resource for researchers and students in the areas of agri-biotechnology, soil biology and fungal biology.

Download or read book Eutrophication of Shallow Lakes with Special Reference to Lake Taihu China written by B. Qin and published by Springer Science & Business Media. This book was released on 2007-12-03 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume features papers presented at the International Symposium on the Eutrophication Process and Control in Large Shallow Lakes-–with Special Reference to Lake Taihu, held in Nanjing, China in April 2005. Coverage includes: physical processes and their effects on shallow lake ecosystems; biogeochemistry of sediments and nutrient cycling in shallow lakes; and algal blooms and ecosystem response in shallow lakes.

Download or read book Biogeochemistry of Inland Waters written by Gene E. Likens and published by Academic Press. This book was released on 2010-05-20 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: A derivative of the Encyclopedia of Inland Waters, Biogeochemistry of Inland Waters examines the transformation, flux and cycling of chemical compounds in aquatic and terrestrial ecosystems, combining aspects of biology, ecology, geology, and chemistry. Because the articles are drawn from an encyclopedia, they are easily accessible to interested members of the public, such as conservationists and environmental decision makers. This derivative text describes biogeochemical cycles of organic and inorganic elements and compounds in freshwater ecosystems

Download or read book Indian Journal of Chemistry written by and published by . This book was released on 1971 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Grants Index written by National Institutes of Health (U.S.). Division of Research Grants and published by . This book was released on 1963 with total page 1042 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nitrogen Fixation in Soybeans revision 1979 1983 written by Jayne T. MacLean and published by . This book was released on 1983 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book National Bureau of Standards Circular written by and published by . This book was released on 1955 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preparation and Measurement of Isotopes and Some of Their Medical Aspects written by Louis Harry Roddis and published by . This book was released on 1948 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: