Size characteristics of soils and sediments with special reference to clay fractions

Soil Research ◽  
1979 ◽  
Vol 17 (3) ◽  
pp. 383 ◽  
Author(s):  
PH Walker ◽  
J Hutka
Keyword(s):  
Particle Size ◽  
Size Fraction ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Size Fractions ◽  
Soils And Sediments ◽  
Eastern Australia ◽  
Fine Clay ◽  
Lake Floor ◽  
Log Normal

Soils and sediments from south-eastern Australia were examined to determine whether texture B horizons had distinctive and unique particle-size characteristics. Most texture B horizons had higher contents of fine clay (<0.2 �m) than coarse clay (0.2-2 �m), whereas coarse clay was the dominant clay-size fraction in A and C horizons. Sequences of soils in alluvium showed a systematic increase in particle-size differentiation with increasing stratigraphic age and corresponding increases in the proportion of fine clay in their B horizons. Pedologically unmodified, clay-rich sediments generally had lower contents of fine clay and higher contents of silt than B horizons. However, sediments of a lake floor and samples of argillans had clay-size fractions similar to B horizons. The distribution of fine clay in soils, determined here by centrifugal sedimentation, was poorly related to illuviated clay determined microscopically. Detailed particle-size data showed that texture B horizons were more enriched than adjacent horizons by a fraction with upper size limits between 0.25 and 0.5 �m. The greater the profile texture contrast, the more pronounced this enrichment became. The enriched clay-size fractions of these B horizons had the particle-size characteristics of log normal distributions. Within the clay-size range of texture B horizons, the fraction < 0.5 �m was the most directly related to surface area measurements made on dry soil samples. Sediments of a lake floor and samples of argillans had similar clay-size characteristics to soil B horizons. It was concluded that particle-size differentiation in these soils was related mainly to pedogenetic processes within the profile. However, the particle-size characteristics of texture B horizons are not unique. Criteria other than those based on particle-size analysis are therefore required to determine the relative importance of translocation and weathering.

scholarly journals Modeling of Permanent Wilting from Particle Size Fractions of Coastal Plain Sands Soils in Southeastern Nigeria

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Chinedu Innocent Obi ◽  
Jude C. Obi ◽  
Emmanuel U. Onweremadu
Keyword(s):  
Particle Size ◽  
Coastal Plain ◽  
Particle Size Analysis ◽  
Coarse Sand ◽  
Size Analysis ◽  
Southeastern Nigeria ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Permanent Wilting Point ◽  
Wilting Point

Permanent wilting points in soils have been found to correlate significantly with particle size fractions. This study was conducted to establish functional relationship between soil particle size fractions and permanent wilting point of soils of coastal plain sands in southeastern Nigeria. A total of 102 surface samples were collected from three different dominantly Ultisols toposequences (i.e., 34 samples from each). Permanent wilting point experiment was carried out in pots with the 102 samples in the greenhouse while the particle size analysis was carried out in the laboratory. There was significant correlation among the textural separates, permanent wilting point correlated significantly with clay (, ). The general linear model showed significant differences between permanent wilting point of soils found in the upper and lower slope positions. Regression equation established that 54% of the total variation in permanent wilting point could be accounted for by the clay and coarse sand content of the soils. Prediction of permanent wilting point of Ultisols formed on coastal plain sands soils of humid tropical southeastern Nigeria will effectively depend on reliability of determination of clay and coarse sand contents of the soils.

scholarly journals A Comparative Evaluation of Cement and By-Product Petrit T in Soil Stabilization

2019 ◽  
Vol 9 (23) ◽  
pp. 5238
Author(s):  
Wathiq Al-Jabban ◽  
Jan Laue ◽  
Sven Knutsson ◽  
Nadhir Al-Ansari
Keyword(s):  
Particle Size ◽  
Soil Stabilization ◽  
Size Fraction ◽  
Dry Weight ◽  
Particle Size Analysis ◽  
Engineering Properties ◽  
Size Analysis ◽  
Treated Soil ◽  
Environmental Threats ◽  
Fine Grained Soil

This study presents a comparison between the effectiveness of adding low binder amounts of industrial by-product Petrit T as well as cement to modify and improve fine-grained soil. Binder amount was added by soil dry weight; cement at 1%, 2%, 4% and 7% and Petrit T at 2%, 4% and 7%. The unconfined compressive strength (UCS) was used as an indicator of soil strength. In addition, the consistency limits, laser particle size analysis, and pH tests were also conducted on the treated soil. The samples were cured at 20 °C for different periods from 7 to 90 days before testing. Results indicate that cement is more effective at improving the physical and engineering properties of the treated soil. Soil plasticity index decreases after treatment and with time. Liquidity index and the water content to plastic limit ratio are introduced as new indices to define the improvement in the workability of treated soil. Soil particle size distribution is changed by reducing the clay size fraction and increasing the silt size fraction after treatment. The findings confirm that adding small binder contents improve soil properties, which subsequently reduce the environmental threats and costs that are associated with using a high amount of binder.

Feeding amount affects the sorting behavior of lactating dairy cows

2010 ◽  
Vol 90 (1) ◽  
pp. 1-7 ◽  
Author(s):  
E K Miller-Cushon ◽  
T J DeVries
Keyword(s):  
Particle Size ◽  
Dairy Cows ◽  
Dry Matter ◽  
Size Fraction ◽  
Particle Size Analysis ◽  
Neutral Detergent Fiber ◽  
Dry Matter Intake ◽  
Size Analysis ◽  
Once Daily ◽  
Lactating Dairy Cows

The objective of this study was to determine whether feed sorting behavior in dairy cattle is influenced by the amount of feed provided. Six lactating Holstein cows, individually fed a total mixed ration once daily, were exposed to two treatments in a crossover design with 7-d periods. The treatments were: (1) lower feed amount (LFA; target 10% orts), and (2) higher feed amount (HFA; target 20% orts). Dry matter intake (DMI) was monitored daily for each animal. On the final 4 d of each treatment period, fresh feed and orts were sampled for particle size analysis. The particle size separator had three screens (19, 8, 1.18 mm) and a bottom pan, resulting in four fractions (long, medium, short, fine). Sorting was calculated as the actual intake of each particle size fraction expressed as a percentage of the predicted intake of that fraction. Actual orts percentage averaged 11.5% for the LFA and 18.0% for the HFA treatments. When on the HFA cows sorted for the medium particles to a greater extent than on the LFA (103.0 vs. 101.1%). Further, when on the HFA treatment cows sorted against short particles to a greater extent than on the LFA (95.2 vs. 98.6%). Despite greater sorting on the HFA treatment, the concentrations of neutral detergent fiber (NDF; 29.6%) and starch (27.1%) in the feed consumed were similar between treatments. Given this, and that DMI was greater on the HFA treatment compared with the LFA treatment (29.7 vs. 26.5 kg d-1), greater intakes of NDF (8.7 vs. 7.8 kg d-1) and starch (8.0 vs. 7.2 kg d-1) were also observed on the HFA treatment. The results suggest that, despite causing greater feed sorting, increasing the feeding amount for lactating dairy cows promoted higher DMI and did not prevent the consumption of a ration balanced to meet their nutritional requirements.Key words: Feeding amount, sorting behavior, dairy cow

FIBER CONTENT, PARTICLE-SIZE DISTRIBUTION AND SOME RELATED PROPERTIES OF FOUR PEAT MATERIALS IN EASTERN CANADA

1977 ◽  
Vol 57 (2) ◽  
pp. 187-195 ◽  
Author(s):  
M. LEVESQUE ◽  
H. DINEL
Keyword(s):  
Particle Size ◽  
Size Fraction ◽  
Chemical Characterization ◽  
Particle Size Analysis ◽  
Exchange Capacity ◽  
Fiber Content ◽  
Size Analysis ◽  
Eastern Canada ◽  
Effective Dispersion

The effects of dispersion and sieving on the determination of fiber content was studied using four peat materials selected for their range of properties. In addition, a method of particle-size analysis of peat materials and chemical characterization data of the particular-size fraction are presented. Controlling the sieving operation effected a reduction in the coefficient of variation of the fiber content data to 2.7% as compared with 26.7% for the conventional rubbed fiber method. The somewhat more effective dispersion of the peat in 0.025 M pyrophosphate than in water did not compensate for the associated disadvantage of increased ash content of the pyrophosphate-treated samples. Thus, the recommended procedure involves dispersion of peat in water for 16 h. The proportion of the 100-mesh (0.15-mm) fraction reflected both the stage of decomposition and the botanical origin of the peat materials. Thus, particle-size fraction would be useful in the characterization of peat materials. Cation exchange capacity and content of both Fe and P varied inversely with particle size.

Particle Size Analysis of Inorganic Dirt in Raw Wool

1988 ◽  
Vol 58 (9) ◽  
pp. 526-530 ◽  
Author(s):  
Franco Ferrero ◽  
Franco Marchese ◽  
Giorgio Fornaro
Keyword(s):  
Particle Size ◽  
Geometric Mean ◽  
Particle Size Analysis ◽  
Ash Content ◽  
Size Analysis ◽  
Normal Model ◽  
Mean Diameter ◽  
Distribution Parameters ◽  
Log Normal ◽  
Different Origin

A method of analyzing the particle size of inorganic dirt in raw wool is described. This method was applied to 25 raw wool samples of different origin, type, fineness, and grease and ash content. The results show that the particle size distribution of inorganic dirt is monomodal and approaches a log-normal model. The distribution parameters such as geometric mean diameter and standard deviation were also evaluated. In all samples, the geometric mean diameter was in the range of 9 to 28 micrometers without any correlation with other raw wool characteristics.

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