scholarly journals Polymineralic Inclusions in Megacrysts as Proxies for Kimberlite Melt Evolution—A Review

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 530 ◽  
Author(s):  
Bussweiler
Keyword(s):  
Chemical Properties ◽  
Major Question ◽  
Secondary Alteration ◽  
Origin And Evolution ◽  
Multi Stage ◽  
Kimberlite Magma ◽  
Physical And Chemical ◽  
Melt Evolution ◽  
And Chemical Properties

Polymineralic inclusions in megacrysts have been reported to occur in kimberlites worldwide. The inclusions are likely the products of early kimberlite melt(s) which invaded the pre‐existing megacryst minerals at mantle depths (i.e., at pressures ranging from 4 to 6 GPa) and crystallized or quenched upon emplacement of the host kimberlite. The abundance of carbonate minerals (e.g., calcite, dolomite) and hydrous silicate minerals (e.g., phlogopite, serpentine, chlorite) within polymineralic inclusions suggests that the trapped melt was more volatile‐rich than the host kimberlite now emplaced in the crust. However, the exact composition of this presumed early kimberlite melt, including the inventory of trace elements and volatiles, remains to be more narrowly constrained. For instance, one major question concerns the role of accessory alkali‐halogen‐phases in polymineralic inclusions, i.e., whether such phases constitute a common primary feature of kimberlite melt(s), or whether they become enriched in late‐stage differentiation processes. Recent studies have shown that polymineralic inclusions react with their host minerals during ascent of the kimberlite, while being largely shielded from processes that affect the host kimberlite, e.g., the assimilation of xenoliths (mantle and crustal), degassing of volatiles, and secondary alteration. Importantly, some polymineralic inclusions within different megacryst minerals were shown to preserve fresh glass. A major conclusion of this review is that the abundance and mineralogy of polymineralic inclusions are directly influenced by the physical and chemical properties of their host minerals. When taking the different interactions with their host minerals into account, polymineralic inclusions in megacrysts can serve as useful proxies for the multi‐stage origin and evolution of kimberlite melt/magma, because they can (i) reveal information about primary characteristics of the kimberlite melt, and (ii) trace the evolution of kimberlite magma on its way from the upper mantle to the crust.

Transportation pathways of pesticides in two major watersheds of Istanbul, Turkey

2004 ◽  
Vol 49 (3) ◽  
pp. 165-172 ◽  
Author(s):  
M. Yazgan ◽  
A. Tanik
Keyword(s):  
Chemical Properties ◽  
Surface Flow ◽  
Priority List ◽  
Pesticide Pollution ◽  
Consumption Values ◽  
Annual Consumption ◽  
Agricultural Areas ◽  
Physical And Chemical ◽  
And Chemical Properties

The study covers the investigation of pesticides in terms of consumption, toxicological classification and various intrinsic physical and chemical properties like DT50, KOC, GUS, solubility that describe the important mechanisms prevailing in soil, namely persistence and mobility. These mechanisms help to estimate the transportation pathways of pesticides on soil till they reach the receiving water after being applied on land. Classification is done in three groups, those likely to appear in surface flow, those that appear in groundwater and those that present transient conditions. Such an approach that also takes into account toxicological levels and annual consumption values of pesticides will act as a tool to prepare the priority list of pesticides that need special care during their transportation. The fate of pesticides is a difficult task to solve, however, such a methodology, puts forth a rough estimate on their behavior in spite of uncertainties in many of the parameters describing mechanisms like persistence and mobility. The agricultural areas of two watersheds of Istanbul are selected as target areas to describe the approach, which is also checked with another approach estimating pesticide pollution potential that considers various other properties of pesticides. Almost similar findings are depicted with 85% proximity. The methodology presented in the paper illustrates and emphasizes the significant role of pesticide properties in determining their fate in soil after being applied.

Basic Performance Research of Polymer Intercalation Clay

2012 ◽  
Vol 578 ◽  
pp. 183-186
Author(s):  
Xiao Chun Cao ◽  
Yi Qin ◽  
Yan Na Zhao ◽  
Kun Ke
Keyword(s):  
Drilling Fluid ◽  
Chemical Properties ◽  
Drilling Fluids ◽  
Technical Problems ◽  
Clay Particles ◽  
Polymer Properties ◽  
Physical And Chemical ◽  
Performance Research ◽  
And Chemical Properties

Using the preliminary research of the polymer properties, the different between the physical and chemical properties of new polymer-clays nanometer composites and clay have been studied. Different polymers are used to evaluate experiment. Based on a large number of lab experiments, the changes of rheological property and API filtration property of polymer-clay drilling fluids nanometer composites are studied. The results show that clay particles could become smaller and the composites drilling fluid have the role of controlling loss and enhancing cake quality. The prepared composites could be used to solve the technical problems in drilling fluid.

Role of lattice defects in catalytic activities of graphene clusters for fuel cells

2015 ◽  
Vol 17 (26) ◽  
pp. 16733-16743 ◽  
Author(s):  
Lipeng Zhang ◽  
Quan Xu ◽  
Jianbing Niu ◽  
Zhenhai Xia
Keyword(s):  
Fuel Cells ◽  
Electronic Structures ◽  
Chemical Properties ◽  
Lattice Defects ◽  
Physical And Chemical Properties ◽  
Catalytic Activities ◽  
Physical And Chemical ◽  
And Chemical Properties

Defects are common but important in graphene, which could significantly tailor the electronic structures and physical and chemical properties.

scholarly journals Partial synthetic models of FeMoco with sulfide and carbyne ligands: Effect of interstitial atom in nitrogenase active site

2021 ◽  
Vol 118 (49) ◽  
pp. e2109241118
Author(s):  
Linh N. V. Le ◽  
Gwendolyn A. Bailey ◽  
Anna G. Scott ◽  
Theodor Agapie
Keyword(s):  
Active Sites ◽  
Chemical Properties ◽  
Metal Centers ◽  
Bridging Ligand ◽  
Reduction Potentials ◽  
Protein Active Sites ◽  
Physical And Chemical ◽  
Synthetic Models ◽  
And Chemical Properties

Nitrogen-fixing organisms perform dinitrogen reduction to ammonia at an Fe-M (M = Mo, Fe, or V) cofactor (FeMco) of nitrogenase. FeMco displays eight metal centers bridged by sulfides and a carbide having the MFe7S8C cluster composition. The role of the carbide ligand, a unique motif in protein active sites, remains poorly understood. Toward addressing how the carbon bridge affects the physical and chemical properties of the cluster, we isolated synthetic models of subsite MFe3S3C displaying sulfides and a chelating carbyne ligand. We developed synthetic protocols for structurally related clusters, [Tp*M’Fe3S3X]n−, where M’ = Mo or W, the bridging ligand X = CR, N, NR, S, and Tp* = Tris(3,5-dimethyl-1-pyrazolyl)hydroborate, to study the effects of the identity of the heterometal and the bridging X group on structure and electrochemistry. While the nature of M’ results in minor changes, the chelating, μ3-bridging carbyne has a large impact on reduction potentials, being up to 1 V more reducing compared to nonchelating N and S analogs.

scholarly journals THE ROLE OF EARTHWORMS IN PASTURE PRODUCTION AND MOISTURE CONSERVATION

1966 ◽  
pp. 168-183 ◽  
Author(s):  
S.M.J. Stockdill ◽  
G.G. Cossens
Keyword(s):  
Soil Erosion ◽  
Chemical Properties ◽  
Infiltration Rate ◽  
Physical And Chemical Properties ◽  
Soil Infiltration ◽  
Pasture Production ◽  
Physical And Chemical ◽  
Soil Infiltration Rate ◽  
And Chemical Properties

RESEARCH has shown that pasture production on soils without earthworms is limited to considerably less than the true potential. Increased production with beneficial earthworms is associated with pronounced changes in the physical and chemical properties of the soil. Infiltration rate is increased, moisture is conserved and the risk of soil erosion is reduced

scholarly journals Cyclodextrins: Structural, Chemical, and Physical Properties, and Applications

2021 ◽  
Vol 3 (1) ◽  
pp. 1-31
Author(s):  
Benjamin Gabriel Poulson ◽  
Qana A. Alsulami ◽  
Abeer Sharfalddin ◽  
Emam. F. El Agammy ◽  
Fouzi Mouffouk ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Chemical Properties ◽  
Aqueous Solubility ◽  
Industrial Applications ◽  
Physical And Chemical Properties ◽  
To Come ◽  
Novel Applications ◽  
Physical And Chemical ◽  
And Chemical Properties

Due to their unique structural, physical and chemical properties, cyclodextrins and their derivatives have been of great interest to scientists and researchers in both academia and industry for over a century. Many of the industrial applications of cyclodextrins have arisen from their ability to encapsulate, either partially or fully, other molecules, especially organic compounds. Cyclodextrins are non-toxic oligopolymers of glucose that help to increase the solubility of organic compounds with poor aqueous solubility, can mask odors from foul-smelling compounds, and have been widely studied in the area of drug delivery. In this review, we explore the structural and chemical properties of cyclodextrins that give rise to this encapsulation (i.e., the formation of inclusion complexes) ability. This review is unique from others written on this subject because it provides powerful insights into factors that affect cyclodextrin encapsulation. It also examines these insights in great detail. Later, we provide an overview of some industrial applications of cyclodextrins, while emphasizing the role of encapsulation in these applications. We strongly believe that cyclodextrins will continue to garner interest from scientists for many years to come, and that novel applications of cyclodextrins have yet to be discovered.

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