scholarly journals End water content determines the magnitude of N2O pulse from nitrifier denitrification after rewetting a fluvo-aquic soil

2021 ◽  
pp. e01824
Author(s):  
Shutan Ma ◽  
Longlong Xia ◽  
Xiaobo Li ◽  
Haitao Wang ◽  
Qi Huang ◽  
...  
Author(s):  
Songquan Sun ◽  
Richard D. Leapman

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.


Author(s):  
R.D. Leapman ◽  
S.Q. Sun ◽  
S-L. Shi ◽  
R.A. Buchanan ◽  
S.B. Andrews

Recent advances in rapid-freezing and cryosectioning techniques coupled with use of the quantitative signals available in the scanning transmission electron microscope (STEM) can provide us with new methods for determining the water distributions of subcellular compartments. The water content is an important physiological quantity that reflects how fluid and electrolytes are regulated in the cell; it is also required to convert dry weight concentrations of ions obtained from x-ray microanalysis into the more relevant molar ionic concentrations. Here we compare the information about water concentrations from both elastic (annular dark-field) and inelastic (electron energy loss) scattering measurements.In order to utilize the elastic signal it is first necessary to increase contrast by removing the water from the cryosection. After dehydration the tissue can be digitally imaged under low-dose conditions, in the same way that STEM mass mapping of macromolecules is performed. The resulting pixel intensities are then converted into dry mass fractions by using an internal standard, e.g., the mean intensity of the whole image may be taken as representative of the bulk water content of the tissue.


1982 ◽  
Vol 43 (C9) ◽  
pp. C9-455-C9-458 ◽  
Author(s):  
M. Takata ◽  
M. Tomozawa ◽  
J. Acocella ◽  
J. Molinelli ◽  
C. Y. Erwin ◽  
...  

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
SULASMI ANGGO

The Analysis of physical chemical from dara shells (Anadara granosa) origin from Kayutanyo, kab. Banggai, has been conducted.Dara shell meat is sleaned and dried and after that powered with blender. Determine % rendement, water bonding capacity and index water solubility with Anderson method, coarse fat content with gravimetric method and carbohydrate method with “bye difference” decrease method.The result of analysis showed rendement value is 24,35%, water bonding capacity is 1,6248 gram/ml, index water solubility is 0,202 gram/ml, water content is 79,0045%, total dust content is 1,072%, coarse protein content is 2,25%, coarse fat content is 8,47%, carbohydrate content is 9,2035%. Keyword : Dara shells, (Anadara granosa), analysis physical chemical


Author(s):  
M.C.H.Mouat Pieter Nes

Reduction in water content of a soil increased the concentration of ammonium and nitrate in solution, but had no effect on the concentration of phosphate. The corresponding reduction in the quantity of phosphate in solution caused an equivalent reduction in the response of ryegrass to applied phosphate. Keywords: soil solution, soil water content, phosphate, ryegrass, nutrition.


10.3383/1.1.8 ◽  
2008 ◽  
Vol 1 (1) ◽  
pp. 109-123 ◽  
Author(s):  
G. LEUCCI ◽  
R. CATALDO ◽  
G. DE NUNZIO

2010 ◽  
Vol 59 (1) ◽  
pp. 157-164 ◽  
Author(s):  
E. Tóth ◽  
Cs. Farkas

Soil biological properties and CO2emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO2fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO2emission.


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