Visual Optics and the Birefringence/Dispersion Ratio of Gemstones

2014 ◽  
Vol 34 (4) ◽  
pp. 281-283
Author(s):  
Pornsawat Wathanakul
2012 ◽  
Vol 9 (1) ◽  
pp. 162-164
Author(s):  
S.V. Khabirov

Distribution of plane, spherical and cylindrical waves in steam-gaseous mixes with unequigranular particles and drops when one of fractions participates in phase changes is studied. The dispersion ratio is received, dispersion curves are calculated. Influence of a polydispersity of particles and drops on dispersion and a dissipation of small indignations is analysed.


2019 ◽  
Vol 6 (04) ◽  
Author(s):  
MINAKSHI SERAWAT ◽  
V K PHOGAT ◽  
ANIL Abdul KAPOOR ◽  
VIJAY KANT SINGH ◽  
ASHA SERAWAT

Soil crust strength influences seedling emergence, penetration and morphology of plant roots, and, consequently, crop yields. A study was carried out to assess the role of different soil properties on crust strength atHisar, Haryana, India. The soil samples from 0-5 and 5-15 cm depths were collected from 21 locations from farmer’s fields, having a wide range of texture.Soil propertieswere evaluated in the laboratory and theirinfluence on the modulus of rupture (MOR), which is the measure of crust strength, was evaluated.The MOR of texturally different soils was significantly correlated with saturated hydraulic conductivity at both the depths. Dispersion ratio was found to decrease with an increase in fineness of the texture of soil and the lowest value was recorded in silty clay loam soil,which decreased with depth. The modulus of rupture was significantly negatively correlative with the dispersion ratio.There was no role of calcium carbonate in influencing the values of MOR of soils. Similarly,the influence of pH, EC and SAR of soil solution on MOR was non-significant.A perusal of thevalues of the correlations between MOR and different soil properties showed that the MOR of soils of Haryana are positively correlated with silt + clay (r = 0.805) followed by water-stable aggregates (r = 0.774), organic carbon (r = 0.738), silt (r = 0.711), mean weight diameter (r = 0.608) and clay (r = 0.593) while negatively correlated with dispersion ratio (r = - 0.872), sand (r = -0.801) and hydraulic conductivity (r = -0.752) of soils.


1953 ◽  
Vol 36 (1) ◽  
pp. 131-132
Author(s):  
James E. Lebensohn
Keyword(s):  

1989 ◽  
Vol 107 (12) ◽  
pp. 1731
Author(s):  
Stephen J. Fricker
Keyword(s):  

Soil Research ◽  
1984 ◽  
Vol 22 (1) ◽  
pp. 59 ◽  
Author(s):  
KJ Coughlan ◽  
RJ Loch

This paper explores the processes responsible for clay dispersion, and the formation of large dry aggregates, in cracking clay soils. It also isolates the soil factors causing variations in dry aggregate size using regression analysis. Twelve cracking clay soil samples were selected on visual differences in dry aggregate size distribution following seedbed preparation, and a range of soil structural and chemical properties were measured. The per cent dry aggregates > 5 mm was found to increase with resistance to mechanical abrasion, stability to wet sieving after capillary wetting, and dispersion ratio, indicating that large dry aggregates are formed as a result of binding by dispersed clay. Both raindrop impact and puddling by cultivation may be involved in dispersion. There was a strong relationship between dry aggregate size in the 0-10 cm layer and salt content in the subsurface (60-90 cm) layer. Coarse surface aggregation is explained in terms of limited profile hydraulic conductivity. For the soils studied, the properties of the surface layer appear to be responsible, at least in part, for the limitation in profile hydraulic conductivity. Dry aggregate size in the 0-10 cm layer was not simply correlated with any of the chemical properties of that layer. However, equations containing two (ESP and CEC per gram of clay) or three (ESP, per cent clay and CEC) independent variables were derived to explain variations in dry aggregate size, both for the 12 soils studied and for a wider range of Queensland cracking clay soils.


1953 ◽  
Vol 30 (1) ◽  
pp. 40
Author(s):  
Joseph I. Pascal ◽  
ROBERT E. BANNON
Keyword(s):  

1972 ◽  
pp. 528-626
Author(s):  
HUGH DAVSON
Keyword(s):  

2006 ◽  
Vol 83 (6) ◽  
pp. 329-330 ◽  
Author(s):  
Anthony J. Adams
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document