scholarly journals Chemical compositions of amphiboles and their references to formation conditions of granitoids from Nam Rom and Song Ma massifs, Northwest Vietnam

2020 ◽  
Vol 42 (1) ◽  
pp. 80-92
Author(s):  
Pham Ngoc Can ◽  
Tran Tuan Anh ◽  
Tran Trong Hoa ◽  
Vu Hoang Ly ◽  
Pham Thi Phuong Lien ◽  
...  
Keyword(s):  
Geochemical Characteristics ◽  
The Other ◽  
Chemical Compositions ◽  
Formula Unit ◽  
Fine Grained ◽  
Basic Stage ◽  
Other Hand ◽  
Formation Conditions ◽  
Similar Formation

In this paper, the mineralogical and geochemical characteristics of amphiboles and plagioclases of granitoids from the Nam Rom and Song Ma massifs have been investigated to understand their formation conditions. The Nam Rom amphibole and plagioclase are subhedral to euhedral fine- to medium-grained crystals. Whereas, the Song Ma amphibole and plagioclase are anhedral to subhedral fine-grained crystals. Geochemical compositions of amphiboles suggest that Nam Rom and Song Ma amphiboles are edenite and ferro-edenite, respectively. Nam Rom edenite has higher contents of basic constituents (Mg and Ca) and lower contents of felsic constituents (Na and K) compared with the Song Ma ferro-edenite. On the other hand, Si-(Na+K) and Si-Ca apfu ratios of the Nam Rom edenite and the Song Ma ferro-edenite and Al/(Na+K)-Al/(Ca+Na+K) atom per formula unit (apfu) ratios of the Nam Rom edenite and andesine and the Song Ma ferro-edenite, andesine and oligoclase are similar. Formation conditions of the Nam Rom and Song Ma granitoids were calculated using amphibole-plagioclase geobarometer. The Nam Rom granitoid was formed at 3.07-5.32 kbar (10.1-17.6 km under paleo-surface) and 750-785°C. The Song Ma granitoid was formed at 1.04-3.08 kbar (3.4-10.2 km under paleo-surface) and 715-745°C. Therefore, Nam Rom and Song Ma granitoids are thought to be crystallized from the same magma. The former was formed from the immature and more basic stage of magma; the latter was formed from the mature and more felsic stage of magma.

Contrasting signatures of the sources and types of aerosols in the western and eastern Himalayas: Radiative implications

2021 ◽  
Author(s):  
Arun Bs ◽  
Mukunda Gogoi ◽  
Prashant Hegde ◽  
Suresh Babu
Keyword(s):  
Mineral Dust ◽  
Water Soluble ◽  
The Other ◽  
Anthropogenic Source ◽  
Chemical Compositions ◽  
Eastern Himalayas ◽  
Chemical Aging ◽  
Other Hand ◽  
Secondary Formation ◽  
The Impact

<p>The rapid changes in the pattern of atmospheric warming over the Himalayas, along with severe degradation of Himalayan glaciers in recent years suggest the inevitability of accurate source characterization and quantification of the impact of aerosols on the Himalayan atmosphere and snow. In this regard, extensive study of the chemical compositions of aerosols at two distinct regions, Himansh (32.4<sup>ᴼ</sup>N, 77.6<sup>ᴼ</sup>E, ~ 4080 m a.s.l) and Lachung (27.4<sup>ᴼ</sup>N, 88.4<sup>ᴼ</sup>E, ~ 2700 m a.s.l), elucidates distinct signatures of the sources and types of aerosols prevailing over the western and eastern parts of Himalayas. The mass-mixing ratios of water-soluble (Na<sup>+</sup>, NH<sub>4</sub><sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Cl-, SO<sub>4</sub><sup>2-</sup>, NO<sub>3</sub><sup>-</sup>, MSA<sup>-</sup>, C<sub>2</sub>O<sub>4</sub><sup>2-</sup>), carbonaceous (EC, OC, WSOC) and selected elemental (Al, Fe, Cu, Cr, Ti) species depicted significant abundance of mineral dust aerosols (~ 67%), along with a significant contribution of carbonaceous aerosols (~ 9%) during summer to autumn (August-October) over the western Himalayan site. On the other hand, the eastern Himalayan site is found to be dominant of OC (~ 53% in winter) followed by SO<sub>4</sub><sup>2-</sup> (as high as 37% in spring) and EC (8-12%) during August to February. However, OC/EC and WSOC/OC ratios showed significantly higher values over both the sites (~ 12.5, and 0.56 at Himansh; ~ 5.7 and ~ 0.74 at Lachung) indicating the secondary formation of organic aerosols via chemical aging over both the sites. The enrichment factors estimated from the concentrations of trace elements over the western Himalayan site revealed the influence of anthropogenic source contribution from the regional hot-spots of Indo-Gangetic Plains, in addition to that of west Asia and the Middle East countries. On the other hand, the source apportionment of aerosols (based on positive matrix factorization - PMF model) over the eastern Himalayas demonstrated the biomass-burning aerosols (25.94%), secondary formation of aerosols via chemical aging (15.94%), vehicular and industrial emissions (20.54%), primary emission sources associated with mineral dust sources (22.28%) and aged secondary aerosols (15.31%) as the major sources of aerosols. Due to abundant anthropogenic source impacts at the eastern Himalayan site, the atmospheric forcing is most elevated in winter (13.4 ± 4.4 Wm<sup>-2</sup>), which is more than two times the average values seen at the western Himalayan region during the study period. The heavily polluted eastern part of the IGP is a potential anthropogenic source region contributing to the aerosol loading at the eastern Himalayas. These observations have far-reaching implications in view of the role of aerosols on regional radiative balance and their impact on snow/glacier coverage.</p>

On Enabling Attribute-Based Encryption to Be Traceable Against Traitors

2020 ◽  
Author(s):  
Zhen Liu ◽  
Qiong Huang ◽  
Duncan S Wong
Keyword(s):  
Access Control ◽  
High Efficiency ◽  
Black Box ◽  
The Other ◽  
Encrypted Data ◽  
Malicious User ◽  
Fine Grained ◽  
Other Hand ◽  
Attribute Based Encryption

Abstract Attribute-based encryption (ABE) is a versatile one-to-many encryption primitive, which enables fine-grained access control over encrypted data. Due to its promising applications in practice, ABE schemes with high efficiency, security and expressivity have been continuously emerging. On the other hand, due to the nature of ABE, a malicious user may abuse its decryption privilege. Therefore, being able to identify such a malicious user is crucial towards the practicality of ABE. Although some specific ABE schemes in the literature enjoys the tracing function, they are only proceeded case by case. Most of the ABE schemes do not support traceability. It is thus meaningful and important to have a generic way of equipping any ABE scheme with traceability. In this work, we partially solve the aforementioned problem. Namely, we propose a way of transforming (non-traceable) ABE schemes satisfying certain requirements to fully collusion-resistant black-box traceable ABE schemes, which adds only $O(\sqrt{\mathcal{K}})$ elements to the ciphertext where ${\mathcal{K}}$ is the number of users in the system. And to demonstrate the practicability of our transformation, we show how to convert a couple of existing non-traceable ABE schemes to support traceability.

Types of Negation

2020 ◽  
pp. 57-74
Author(s):  
Karen De Clercq
Keyword(s):  
Critical Review ◽  
Careful Analysis ◽  
The Other ◽  
Fine Grained ◽  
Other Hand ◽  
The One

This chapter discusses the well-known dichotomies between sentence negation and constituent negation on the one hand and external negation and internal negation on the other hand. It explains how the notions differ and where they show overlap. Crucial in this discussion is the presentation and critical review of some of the most relevant tests for negation as discussed by Klima (1964). The discussion leads to the observation that both sentence negation and constituent negation are umbrella terms for multiple scopal types of negation. The chapter further shows how a careful analysis of negative morphology can be insightful in putting up a more fine-grained classification that does better justice to the reality of negative markers than captured by the well-known dichotomies.

scholarly journals Speed of time-compressed forward replay flexibly changes in human episodic memory

2018 ◽  
Author(s):  
Sebastian Michelmann ◽  
Bernhard P. Staresina ◽  
Howard Bowman ◽  
Simon Hanslmayr
Keyword(s):  
Episodic Memory ◽  
Dynamic Process ◽  
Temporal Patterns ◽  
Forward Direction ◽  
The Other ◽  
Complex Task ◽  
Fine Grained ◽  
Other Hand ◽  
The One ◽  
Exact Timing

SummaryRemembering information from continuous past episodes is a complex task. On the one hand, we must be able to recall events in a highly accurate way that often includes exact timing; on the other hand, we can ignore irrelevant details and skip to events of interest. We here track continuous episodes, consisting of different sub-events, as they are recalled from memory. In behavioral and MEG data, we show that memory replay is temporally compressed and proceeds in a forward direction. Neural replay is characterized by the reinstatement of temporal patterns from encoding. These fragments of activity reappear on a compressed timescale. Herein, the replay of sub-events takes longer than the transition from one sub-event to another. This identifies episodic memory replay as a dynamic process in which participants replay fragments of fine-grained temporal patterns and are able to skip flexibly across sub-events.

scholarly journals VI. — The Igneous Geology of the Bathgate and Linlithgow Hills. Part. II. Petrography

1906 ◽  
Vol 45 (1) ◽  
pp. 133-150 ◽  
Author(s):  
J. D. Falconer
Keyword(s):  
Chemical Composition ◽  
Water Vapour ◽  
The Other ◽  
Compact Structure ◽  
Open Structure ◽  
Secondary Minerals ◽  
Fine Grained ◽  
Sedimentary Deposits ◽  
Other Hand ◽  
Coal Fields

The lavas of the Bathgate and Linlithgow Hills occur, as already described, in a series of zones alternating with sedimentary deposits. So far as their field characters are concerned they may be grouped with convenience into two classes: fine-grained, columnar, basaltic types, usually porphyritic with augite and olivine, rarely with felspar, and coarser-grained, doleritic types, usually much decomposed, not evidently porphyritic or porphyritic with olivine alone. The yellow crusts of the compact lavas are minutely vesicular and pumiceous, while steam-cavities are rare in the interior. The doleritic lavas on the other hand are coarsely vesicular and amygdaloidal above and below, and frequently also throughout. The blue basaltic types are relatively very fresh; the doleritic types are frequently entirely decomposed into a whitish, earthy material, with knots of limonite, calcite, and quartz, similar in many respects to the white trap of the coal-fields. Good examples of this mode of weathering may be found in the Riccarton Burn. The differences in texture are probably to be referred not so much to differences in chemical composition as to the effect of variation in the quantity of water vapour contained in the successive flows. The coarse and open structure of the dolerites has evidently also given freer scope to the action of decomposing influences than the more compact structure of the basalts. Both types are much veined by such secondary minerals as calcite, siderite, limonite, quartz, chalcedony, and various zeolites. Frequently cavities in the veins, steam-holes in the pumiceous crusts, and even vesicles within the solid rocks, are found filled with brown viscous pitch or black lustrous asphalt. Such occurrences undoubtedly indicate that these rocks have been subjected to some slight extent to post-volcanic pneumatolytic action.

scholarly journals Textures and Chemical Compositions of Nb-Bearing Minerals and Nb Mineralization in the Shuangshan Nepheline Syenite Pluton, East Qinling, China

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1163
Author(s):  
Hong Wang ◽  
Yong Tang ◽  
Yu-Sheng Xu ◽  
Hui Zhang ◽  
Zheng-Hang Lv ◽  
...  
Keyword(s):  
Hydrothermal Alteration ◽  
Nepheline Syenite ◽  
Henan Province ◽  
The Other ◽  
Chemical Compositions ◽  
Alkaline Complex ◽  
Hydrothermal Zircon ◽  
Quantitative Calculation ◽  
Other Hand ◽  
Different Origins

The Shuangshan alkaline complex located in the Henan province of China is a newly discovered, potentially giant niobium (Nb) deposit. A variety of Nb-bearing minerals including pyrochlore, zircon, and titanite have been identified in this deposit. Distinct textural and chemical differences of pyrochlore and zircon indicate that both have different origins. The magmatic pyrochlore and zircon both have euhedral grains with small sizes. On the other hand, hydrothermal pyrochlore is mainly intergrown on the edge or inside of hydrothermal zircon in the form of an aggregate. Compared with magmatic pyrochlore, the contents of F, Ca, and Na in hydrothermal pyrochlore are obviously high. The texture and composition of hydrothermal pyrochlore and zircon indicate that Ca-bearing hydrothermal alteration resulted in the migration of Nb from Nb-bearing zircon and the reprecipitation of Nb to form aggregate pyrochlore. However, the quantitative calculation shows that the amount of Nb migrated from zircon is very small. Therefore, this study suggests that hydrothermal alteration plays a certain role in the redistribution of Nb, but the enrichment of Nb is limited.

Postscript

Focaal ◽  
2014 ◽  
Vol 2014 (68) ◽  
pp. 83-88 ◽  
Author(s):  
Lorna A. Rhodes
Keyword(s):  
Global South ◽  
The Other ◽  
Fine Grained ◽  
Other Hand ◽  
Thematic Section ◽  
Industrial Democracies ◽  
Future Work

Although the modern prison was one aspect of colonial control, the literature on penality centers almost entirely on the ways in which control of populations has played out in advanced, industrial democracies. Each of the articles in this thematic section, on the other hand, describes a prison in one of the countries of the global South. The authors have given us beautifully fine-grained descriptions of the internal world of these prisons and much to think about in terms of possible directions for future work.

scholarly journals Materials research in conservation and heritology

1970 ◽  
pp. 129
Author(s):  
Ulla Knuutinen
Keyword(s):  
Cultural Heritage ◽  
Environmental Conditions ◽  
The Other ◽  
Reliable Information ◽  
Chemical Compositions ◽  
Other Hand ◽  
Materials Research ◽  
Properties Of Materials ◽  
Cultural Heritage Objects ◽  
Physical Changes

This article is based on the dissertation by the author. It creates a connection between materials research and conservation and heritology. Materials research is a part of multidisciplinary heritology and it has an important role in preserving cultural heritage. If reliable information for the documentation is needed about the materials in an object, on the origin of the object, on the authenticity of the object or on whether any restoration has been carried out previously, analyses that reveal chemical compositions must be performed. On the other hand, the materials research can be focused on examining the ageing properties of materials to find out the chemical and physical changes caused by different environmental conditions. This kind of research benefits the preservation of cultural heritage objects, because results can be applied to both preventive and active conservation. Furthermore, materials research is needed for testing and examining the conservation and restoration methods. 

Tetra-μ2-cyano-κ8 C:N-μ2-2,6-dimethylpyrazine-κ2 N:N′-hexakis(2,6-dimethylpyrazine-κN)octa-μ2-thiocyanato-κ16 N:S-decacopper(I,II)

2006 ◽  
Vol 62 (4) ◽  
pp. m721-m723 ◽  
Author(s):  
Inke Jess ◽  
Christian Näther
Keyword(s):  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Formula Unit ◽  
Asymmetric Unit ◽  
Special Position ◽  
Coordination Network ◽  
Other Hand ◽  
Square Planar

The asymmetric unit of the title compound [Cu8 ICu2 II(CN)4(NCS)8(C6H8N2)7], consists of six crystallographically independent Cu atoms, four thiocyanate anions and two cyanide anions, as well as four 2,6-dimethylpyrazine ligands. Two of the six Cu atoms and one of the four 2,6-dimethylpyrazine ligands are located on centres of inversion. The ligand on a special position is therefore disordered due to symmetry. Altogether there are two copper(II) and eight copper(I) cations in the formula unit. The copper(II) cations are each coordinated by four N atoms within a slightly distorted square-planar coordination. The copper(I) cations, on the other hand, are coordinated by four ligands or anions within distorted tetrahedra. From this arrangement, a three-dimensional coordination network is formed.

scholarly journals X. On the mineral constituents of meteorites

1870 ◽  
Vol 160 ◽  
pp. 189-214 ◽  
Keyword(s):  
Chemical Separation ◽  
The Other ◽  
Fine Grained ◽  
Other Hand ◽  
Mineralogical Investigation ◽  
The One ◽  
Theoretical Considerations ◽  
Mineral Constituents ◽  
Insoluble Portion

I. The applications of the Microscope in the investigation of Meteorites . The mineralogical investigation of a meteoric stone presents difficulties very similar to those which have hitherto rendered the analyses and descriptions of many of the finer-grained terrestrial rocks unsatisfactory ; for a meteoric stone is in fact a fragment of a rock, though formed under conditions in some respects widely differing from those which have produced the rocks of our globe. The difficulties alluded to arise from the minute size and imperfectly developed crys­tallisation of the mineral constituents alike of the rock and the aërolite ; and they have in general baffled the efforts of the chemist on the one hand to effect their separate analyses, and of the crystallographer on the other hand to determine the forms of these constituents. The chemist indeed has endeavoured to overcome the difficulty by attempt­ing a chemical separation of the constituent minerals of these fine-grained mixtures into one group of such as are soluble and another group of those which are insoluble in acids, and then treating the numbers obtained from the analyses of these groups by the light of theoretical considerations founded on the formulae and properties of known minerals. This method is necessarily only an approximative one. Even granting that by its means, we could divide a rock into two classes of ingredients, which we cannot in fact accurately do, there remains the question of how to separate from each other the mingled minerals in, for instance, its insoluble portion.

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