Yehia H. Dawood

8 Questions 32 Answers 0 Followers

Questions related from Yehia H. Dawood

What does it mean if smectite is absent from dry stream sediments?

Illite and kaolinite are reported in dry stream sediments but smectite is totally absent. How to interpret?

11 March 2018 8,640 4 View

What are the exact values of ZTR index to discriminate between mineralogical mature, sub-mature and immature sediments?

Zircon, tourmaline and rutile index is used to differentiate between different maturity of sediments.

27 February 2018 2,885 3 View

Can mineral chemistry of Allanite grains from stream sediments be helpful to differentiate between Igneous and metamorphic source rocks?

Allanite lies within epidote group that contain a significant amount of rare-earth elements. The mineral occurs mainly in metamorphosed clay-rich sediments and felsic igneous rocks. Is it possible...

17 December 2017 6,908 4 View

CEC is high in clay due to -ve charges after replacement of Al and Si. Organic matters has even higher CEC, what causes -ve charge on humus?

What are the reasons of negative charges on the soil humus to make it of high CEC?. Also, what is the reason for the displacement of cations from clay and humus by another cations as shown in the...

12 December 2017 7,315 4 View

Is there a new laboratory confirmation for the formation of uranyl oxyhydroxides as an intermediate phase between uranyl and uranous minerals phases?

Uranyl oxyhydroxides phases were described to be formed in deep parts as a result of hydrothermal solutions interaction with primary uranium minerals, is there new and updated laboratory study to...

26 November 2017 6,197 1 View

Does anyone know of other radionuclides that can be removed by apatite?

We have published about the ability of apatite for attenuation of uranium from water. Ca in calcium phosphate can be replaced by uranyl ion which commonly exists in oxidized shallow groundwater....

09 April 2014 9,235 2 View

Why does half of the parent convert to daughter after the half life time while the other half is left behind in radioactive decay?

What are the rules and who decides which radionuclide is going to decay to daughter and which one is going to remain behind?

02 April 2014 5,656 7 View

The Enrichment factor (EF) in some papers is written as: EF=(Cn/Cref)/(Bn/Bref), while in others as: EF=(Cn/Bn)soil/(Cref/Bref)crust.Which is correct?

The behavior of a given element in soil (i.e., the determination of its accumulation or leaching) may be established by comparing concentrations of a trace element with a reference element. The...

01 January 1970 8,169 4 View