نتایج جستجو برای: total nitrogen

تعداد نتایج: 902330  

2010
M. Lin J. Walker

There is growing evidence that organo-nitrogen compounds may constitute a significant fraction of the aerosol nitrogen (N) budget. However, very little is known about the abundance and origin of this aerosol fraction. In this study, the concentration of organic nitrogen (ON) and major inorganic ions in PM2.5 aerosol were measured at the Duke Forest Research Facility near Chapel Hill, NC, during...

2016
Yu Zhao Baoqing Shan Wenzhong Tang Hong Zhang Nan Rong Yuekui Ding

The Haihe River Basin, which is one of the most water-scarce and polluted river basins in China, has abnormally high nitrogen levels. In this study, total hydrolyzable amino acids (THAAs) were measured in surface sediment and sediment core samples in the Haihe River Basin to determine if amino acids were potential sources of ammonium, organic nitrogen, and organic carbon. The rivers were found ...

Journal: :مجله انسان، محیط زیست و ارتقاء سلامت 0
mohammad reza mehrasbi dept. of environmental health, zanjan university of medical sciences, zanjan, iran. zohre farahmand kiaa dept. of environmental health, zanjan university of medical sciences, zanjan, iran.

background: qual2k is a stream water quality model and was used to evaluate the water quality of the kine-vars river and assess the response of the river to nutrient management strategies. methods: for that purpose, 7 sample stations were selected and surface water samples were collected in the winter and summer of 2012 and were analyzed for temperature, dissolved oxygen, biological oxygen dema...

2015
Jiao Ding Yuan Jiang Lan Fu Qiuzhi Peng Muyi Kang Richard Skeffington

Understanding the relationship between land use and surface water quality is necessary for effective water management. We estimated the impacts of catchment-wide land use on water quality during the dry and rainy seasons in the Dongjiang River basin, using remote sensing, geographic information systems and multivariate statistical techniques. The results showed that the 83 sites can be divided ...

Ahmad Zare Javid, Azadeh Mirzaie, Behnam Moradi, Hossein Bahrani, Maryam Ravanbakhsh, Mokhtar Abbasi, Neamat Jaafarzadeh Haghighi Fard, Rahman Alivar Babadi,

Background: Composting as a waste management technology is becoming more widespread. The purpose of this study was to assess the feasibility and to find the most effective composting process for the ratio of green waste, digested and dewatered sludge from Chonibieh wastewater treatment plant in the west region of Ahvaz. Methods: The composting time was 23 days and the evaluated parameters in th...

Journal: :Plant physiology 1992
A Makino H Sakashita J Hidema T Mae K Ojima B Osmond

The amounts of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), total chlorophyll (Chl), and total leaf nitrogen were measured in fully expanded, young leaves of wheat (Triticum aestivum L.), rice (Oryza sativa L.), spinach (Spinacia oleracea L.), bean (Phaseolus vulgaris L.), and pea (Pisum sativum L.). In addition, the activities of whole-chain electron transport and carbonic anhydr...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2010
Junguo Liu Liangzhi You Manouchehr Amini Michael Obersteiner Mario Herrero Alexander J B Zehnder Hong Yang

Crop production is the single largest cause of human alteration of the global nitrogen cycle. We present a comprehensive assessment of global nitrogen flows in cropland for the year 2000 with a spatial resolution of 5 arc-minutes. We calculated a total nitrogen input (IN) of 136.60 trillion grams (Tg) of N per year, of which almost half is contributed by mineral nitrogen fertilizers, and a tota...

2015
Chengyuan Hao Hebing Zhang Jian Zhou

The spatial variation of soil physical and chemical properties in Funiu Mountain was studied to provide references for identifying soil spatial variation mechanism in bordering land of China warm temperate zone and northern subtropical region. Using vertical gradient sampling and traditional statistics method, the soil samples at the altitude from 1640 m to 1870 m were collected to compare phys...

Journal: :Environmental and experimental botany 2000
Falkengren-Grerup Månsson Olsson

Uptake capacity of organic nitrogen was studied in solution experiments on eight grasses and two forbs growing in acid soils with relatively high nitrogen mineralisation in southern Sweden. Uptake of a mixture of amino acids (alanine, glutamine, glycine), that varied between 1.6 and 6.3 µmol g(-1) dw root h(-1), could not be explained by soil data from the species' field distributions (pH, tota...

2017
Valcenir Júnior Mendes Furlan Victor Maus Irineu Batista Narcisa Maria Bandarra

The high costs and environmental concerns associated with using marine resources as sources of oils rich in polyunsaturated fatty acids have prompted searches for alternative sources of such oils. Some microorganisms, among them members of the genus Aurantiochytrium, can synthesize large amounts of these biocompounds. However, various parameters that affect the polyunsaturated fatty acids produ...

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