Total nitrogen in lunar soils,breccias and rocks     

P.S Goel  P.N Shukla  B.K Kothari  A.N Garg 《Geochimica et cosmochimica acta》1975,39(10):1347-1352

The total nitrogen contents of a number of lunar samples from Apollo 16 and 17 missions are reported. Solar wind is the main source for the observed excess nitrogen in most fines. Total nitrogen in the soils is found to be proportional to the solar wind rare gases Ar³⁶ and Xe¹³². Linear correlations are also noted between the agglutinate contents of the soils and their carbon and nitrogen contents. Seventeen soils (Apollo 15, 16 and 17) have been sieved and nitrogen has been measured in various grain size fractions. An inverse correlation between the mean grain diameter and the nitrogen contents is seen, showing that a large fraction of the solar wind nitrogen is surface correlated. An apparent volume component, due to the presence of agglutinates, is found in most soils.  相似文献   

Total nitrogen in meteorites     

B.K Kothari  P.S Goel 《Geochimica et cosmochimica acta》1974,38(10):1493-1507

Total N has been measured in a number of meteorites by neutron activation analysis using the reaction N¹⁴(n, p)C¹⁴. From each meteorite a number of chips have been analysed to investigate the variation of N contents in a sample. Many meteorites are found to contain a heterogeneous distribution of N. Eighteen chondrites, mostly of the classes C3, H4, H5, L4, L5, L6 and LL6, and six achondrites are found to have average N contents of 10–45 ppm. These do not show any clear-cut dependence of N on petrological group. However, the inherent heterogeneity or the fact that from most meteorite classes only single falls were studied might be responsible for this lack of correlation. In Cold Bokkeveld (C2) N is high (420 ppm). Unlike C, N content of ureilites is low (26 ppm). Nitrogen is enriched in the non-magnetic as compared to the magnetic fractions in H-group chondrites. Analyses of sieved Bjurböle phases show no enrichment of N in finer matrix material, nor any depletion in chondrules. In two gas-rich meteorites, Kapoeta and Assam, there is no excess N in the dark phases. Nine iron meteorites and three mesosiderites were analysed. Twenty analyses of Canyon Diablo and seven of Odessa establish a very heterogeneous N distribution in these meteorites.  相似文献   

Modeling the effects of controlled drainage at a watershed scale using SWATDRAIN     

Golmar Golmohammadi  Ramesh Rudra  Shiv Prasher  Ali Madani  Pradeep Goel  Kourosh Mohammadi 《Arabian Journal of Geosciences》2016,9(11):582

The recently developed SWATDRAIN model was employed to assess the impact of controlled drainage on the water table dynamics, subsurface drainage, and surface runoff in an agricultural watershed in Ontario, Canada. Controlled drainage was defined with a depth of 1.0 m to restrict flow at the drain outlet to maintain the water table at 0.5 m below the surface level during the winter (November–April) and at 0.6 m during the summer (June–August) months. The effects of the absence, or implementation, of drainage water management were predicted for the 3-year period of 1991–1993. Implementing controlled drainage resulted in a 16 % reduction in the mean annual drain flow, while increasing surface runoff by as much as 71 %. This indicates that overall watershed hydrology could be significantly impacted by the implementation of controlled drainage. This research demonstrates the SWATDRAIN model’s ability to predict the controlled drainage in small agricultural watersheds.  相似文献