SOIL AGGREGATE SIZE DISTRIBUTIONS USING X-RAY IMAGES

1998 ◽  
Vol 41 (4) ◽  
pp. 1207-1215 ◽  
Author(s):  
E. W. Tollner ◽  
N. D. Melear ◽  
L. A. Rodriguez ◽  
M. E. Wright
Keyword(s):  
Aggregate Size ◽  
Soil Aggregate ◽  
Size Distributions ◽  
X Ray

scholarly journals Study of soil aggregate breakdown dynamics under low dispersive ultrasonic energies with sedimentation and X-ray attenuation

2015 ◽  
Vol 29 (4) ◽  
pp. 501-508 ◽  
Author(s):  
Jasmin Schomakers ◽  
Franz Zehetner ◽  
Axel Mentler ◽  
Franz Ottner ◽  
Herwig Mayer
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Size Distribution ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
X Ray ◽  
Aggregate Size Distribution ◽  
Aggregate Breakdown ◽  
Wet Sieving

Abstract It has been increasingly recognized that soil organic matter stabilization is strongly controlled by physical binding within soil aggregates. It is therefore essential to measure soil aggregate stability reliably over a wide range of disruptive energies and different aggregate sizes. To this end, we tested highaccuracy ultrasonic dispersion in combination with subsequent sedimentation and X-ray attenuation. Three arable topsoils (notillage) from Central Europe were subjected to ultrasound at four different specific energy levels: 0.5, 6.7, 100 and 500 J cm-3, and the resulting suspensions were analyzed for aggregate size distribution by wet sieving (2 000-63 μm) and sedimentation/X-ray attenuation (63-2 μm). The combination of wet sieving and sedimentation technique allowed for a continuous analysis, at high resolution, of soil aggregate breakdown dynamics after defined energy inputs. Our results show that aggregate size distribution strongly varied with sonication energy input and soil type. The strongest effects were observed in the range of low specific energies (< 10 J cm-3), which previous studies have largely neglected. This shows that low ultrasonic energies are required to capture the full range of aggregate stability and release of soil organic matter upon aggregate breakdown.

Soil aggregate size-dependent relationships between microbial functional diversity and multifunctionality

2021 ◽  
Vol 154 ◽  
pp. 108143
Author(s):  
Shun Han ◽  
Manuel Delgado-Baquerizo ◽  
Xuesong Luo ◽  
Yurong Liu ◽  
Joy D. Van Nostrand ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Microbial Functional Diversity ◽  
Size Dependent

scholarly journals Review of Respirable Coal Mine Dust Characterization for Mass Concentration, Size Distribution and Chemical Composition

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 426
Author(s):  
Behrooz Abbasi ◽  
Xiaoliang Wang ◽  
Judith C. Chow ◽  
John G. Watson ◽  
Bijan Peik ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Particle Size ◽  
Real Time ◽  
Coal Mine ◽  
Energy Dispersive ◽  
Size Distributions ◽  
X Ray ◽  
Membrane Filters ◽  
Mine Dust ◽  
Mass Concentrations

Respirable coal mine dust (RCMD) exposure is associated with black lung and silicosis diseases in underground miners. Although only RCMD mass and silica concentrations are regulated, it is possible that particle size, surface area, and other chemical constituents also contribute to its adverse health effects. This review summarizes measurement technologies for RCMD mass concentrations, morphology, size distributions, and chemical compositions, with examples from published efforts where these methods have been applied. Some state-of-the-art technologies presented in this paper have not been certified as intrinsically safe, and caution should be exerted for their use in explosive environments. RCMD mass concentrations are most often obtained by filter sampling followed by gravimetric analysis, but recent requirements for real-time monitoring by continuous personal dust monitors (CPDM) enable quicker exposure risk assessments. Emerging low-cost photometers provide an opportunity for a wider deployment of real-time exposure assessment. Particle size distributions can be determined by microscopy, cascade impactors, aerodynamic spectrometers, optical particle counters, and electrical mobility analyzers, each with unique advantages and limitations. Different filter media are required to collect integrated samples over working shifts for comprehensive chemical analysis. Teflon membrane filters are used for mass by gravimetry, elements by energy dispersive X-ray fluorescence, rare-earth elements by inductively coupled plasma-mass spectrometry and mineralogy by X-ray diffraction. Quartz fiber filters are analyzed for organic, elemental, and brown carbon by thermal/optical methods and non-polar organics by thermal desorption-gas chromatography-mass spectrometry. Polycarbonate-membrane filters are analyzed for morphology and elements by scanning electron microscopy (SEM) with energy dispersive X-ray, and quartz content by Fourier-transform infrared spectroscopy and Raman spectroscopy.

Aging shapes the distribution of copper in soil aggregate size fractions

2018 ◽  
Vol 233 ◽  
pp. 569-576 ◽  
Author(s):  
Qi Li ◽  
Huihui Du ◽  
Wenli Chen ◽  
Jialong Hao ◽  
Qiaoyun Huang ◽  
...  
Keyword(s):  
Aggregate Size ◽  
Soil Aggregate ◽  
Size Fractions
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