Book•
The x-ray identification and crystal structures of clay minerals
01 Jan 1961-
About: The article was published on 1961-01-01 and is currently open access. It has received 966 citations till now. The article focuses on the topics: Clay minerals.
Citations
More filters
TL;DR: In this paper, the asphaltenes separated from some Middle East, crude oils and tar pollutants were studied by different modem techniques in order to identify its inorganic and organic composition.
Abstract: The asphaltenes separated from some Middle East, crude oils and tar pollutants were studied by different modem techniques in order to identify its inorganic and organic composition. The relationship between the crude oils and tar pollutants were also determined. Each area studied has revealed specific inorganic composition and its mineralogy were, for the first time, identified: silica-solid solution, Al-silicate, Al-oxides, other sulphates were identified in its composition. IR and NMR spectra show the same characteristic bands of tar asphaltenes Compared with that of crude oils.
1 citations
01 Jan 2021
TL;DR: In this article, a number of wild species of Triticum, Aegilops, and other genera have been shown to have in their grains 2-fold higher Fe and Zn relative to modern hexaploid wheat cultivars.
Abstract: Hidden hunger arises when the food consumed by people does not provide adequate micronutrients like vitamins and minerals, iron (Fe) and zinc (Zn), etc. Bio-availability of Fe and Zn in soil have significant roles in the mineral micronutrient uptake and concentration in plants. The inherited low concentration and low bioavailability of Fe and Zn in cereal grains contributed a lot to Fe and Zn deficiency in people, which is widespread, mainly in areas where cereal-based foods are dominant in the diets. Genetic biofortification may enrich cereal grains with micronutrient especially iron and zinc. QTLs for grain iron and zinc have also been mapped in populations derived from crosses between diploid wheat, durum wheat, and wild Emmer wheat and also in synthetic hexaploid wheat and T. spelta. A number of wild species of Triticum, Aegilops, and other genera have been shown to have in their grains 2–3-fold higher Fe and Zn relative to modern hexaploid wheat cultivars. Synthetic hexaploid (SH) wheat (AABBD’D’) has been developed and utilized to bridge gene transfer from Ae. tauschii and durum wheat to hexaploid bread wheat. A more recent outcome of the utilization of SH has been the development and release of high grain Zn varieties. Utilizing this variation, HarvestPlus has released several varieties of wheat with 4–10 ppm higher zinc content.
1 citations
01 Jan 1980
TL;DR: Two o u tcro ps of the Rome Fo rmat i o n and lower Conasauga Group, lo cated o n the Oak R i dge Nati o nal Laborato ry Reservat i on were stu d i ed wi th respect to thei r petro l og i c, m i neralog i c, and I o n exc hange c haracter i st i cs.
Abstract: Two o u tcro ps of the Rome Fo rmat i o n and lower Conasauga Group , lo cated o n the Oak R i dge Nat i o nal Laborato ry Reservat i on were stu d i ed wi th respect to thei r petro l og i c , m i neralog i c , and i o n exc hange c haracter i st i cs . Twen ty-ei g ht sampl e pai rs (a pai r consi sted o f a fresh and weathered segmen t ) were taken from each o u tc ro p . The arg i llaceo us samp l es were analyzed by x-ray d i ffrac t i o n and the remai n i ng samples by th i n sec t i o n anal ysi s . Us i ng an ammo n i a el ectrode , C EC values were determi ned fo r all arg i l l aceo us samp l es an d selec ted non-argi llaceo us samples . Po rosi ty determi nat i ons o f the fresh segments o f the sandsto nes and si l tsto nes were made , usi ng 1 0 to 1 2 mi cro n th i c k petro g raphi c sec t i o ns . X-ray analysi s establi shed the presence o f i l l i te , glauco n i te , kaoli n i te , chlo r i te , b i o t i te , muscovi te , quartz , hemat i te , calc i te , dolomi te , Kspar , and plag i oc l ase . Quanti f i cat i o n o f shal es i s compli cated by the clay mi neral s , therefore the data i s stri ctly quali tati ve . The p resence o f randomly i n terstrati fi ed clays , d i sc rete crystal li tes , or a comb i nati o n was suggested by a few broad peaks o n the d i ffrac tog rams . The exact nat u re o f these peaks was undetermi nabl e i n t h is stu dy . Fo r the arg i ll aceo us samp l es , C EC's ranged from 5 . 5 2 to 33 . 6 1 meq/100 g . A few sandsto nes anal yzed generall y had values at o r bel ow the lowest val ue of the si ltstones . C l ay m i neral co n tent ( by v i sual est i mates ) appeared to be d i rec t l y p roport i onal to C EC values . Quart z , Kspar , matri x , cement ( q uartz overg rowths , hemati te , cal c i te ) , g l auco n i te , p l ag i oc l ase , musco v i te, and b i ot i te were the
1 citations
TL;DR: A low charge octitic montmorillonite derived from altered Tertiary pyroclastics in Italy is discussed in this paper, which shows an 18 A first order basal reflection if potassium saturated and glycerol solvated.
1 citations
Dissertation•
01 Jan 1981
TL;DR: For example, Tius et al. as mentioned in this paper showed that the surfaces of swelling layer silicates like montmorillonite are acidic, and that basic molecules such as ammonia gas, widely used as a nitrogenous fertilizer, or aminotriazole, a systemic herbicide, are protonated on contact with these surfaces and are adsorbed there as cations.
Abstract: The infrared spectroscopy (IR) group at the Macaulay Institute has gained international recognition for research that has led to increased knowledge of weathering phenomena and the pedological development of soil profiles, and to a better understanding of many of the processes that have a bearing on the fertility of agricultural soils. The investigations have concerned both inorganic and organic soil constituents, and have Bought to establish the structures and properties of these components, and their possible roles in soil chemistry. Tius, in the inorganic field, IR has made significant and frequently unique contributions to the identification of new minerals, and to the elucidation of their structures. This is particularly true of the poorly crystallized minerals such as imogolite and allophane which are now recognized as products formed during the development of podzolic soils. While it is necessary to know the bulk structures of soil clay minerals, it is even more important to know the structure of the surfaces, because it is there that adsorption and exchange of nutrient ions, fertilizers, herbicides etc. occurs. Investigations of the surfaces of many clay minerals by IR have given an insight into their reactivities. For example, it has been shown that the surfaces of swelling layer silicates like montmorillonite are acidic, and that basic molecules such as ammonia gas, widely used as a nitrogenous fertilizer, or aminotriazole, a systemic herbicide, are protonated on contact with these surfaces and are adsorbed there as cations. A different type of surface reactivity is exhibited by the oxide and hydroxide minerals. For them, adsorption occurs by ligand exchange of surface hydroxyl groups, and IR has identified for the first time, a singly coordinated OH group on the goethite '-FeOOH) surface, that is replaced by fertilizer ions such as phosphate, sulphate and nitrate. Goethite occurs widely in soils, but more significantly, it has a surface structure that is thought to be closely related to those of the more amorphous iron oxides that occur commonly in coatings on mineral grains in soils. Soil organic matter, although complex, can be separated into various fractions. Some of them, because of their solubility in water, are capable of movement in soil, where they have a role in profile development, and are partly responsible for soil characteristics such as crumb structure. IR has had major success in the characterization of some of these fractions; one of the water-soluble f'ulvic acids for example has been shown to be a polycarboxylic acid with aliphatic rather than aromatic character, containing negligible amounts of carbohydrate and nitrogenous components. This fulvic acid is very similar to synthetic polymaleic anhydride, an observation which may help to more fully elucidate the structure of the natural material which is thought to be involved during the intermediate stages of podzol development. Ultraviolet absorption spectroscopy has been used less extensively, but it has given insights into the metabolic pathways by which lignin is degraded by soil fungi, and has highlighted the existence of an extracellular alcohol oxidase that is probably involved in the early attack of the lignin in wood. These observations are pedologically significant, because degraded lignin is a likely source of some of the phenolic compounds that are implicated in the early leaching and weathering of rocks.
1 citations