scholarly journals On the Chemical Identification and Classification of Minerals

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 591 ◽  
Author(s):  
Ferdinando Bosi ◽  
Cristian Biagioni ◽  
Roberta Oberti
Keyword(s):  
Worked Examples ◽  
Mineral Chemistry ◽  
Mineral Species ◽  
Total Charge ◽  
Structure Topology ◽  
Mineral Structure ◽  
Anionic Complexes ◽  
Mineral Identification ◽  
Hierarchical Scheme

To univocally identify mineral species on the basis of their formula, the IMA-CNMNC recommends the use of the dominant-valency rule and/or the site-total-charge approach, which can be considered two procedures complementary to each other for mineral identification. In this regard, several worked examples are provided in this study along with some simple suggestions for a more consistent terminology and a straightforward use of mineral formulae. IMA-CNMNC guidelines subordinate the mineral structure to the mineral chemistry in the hierarchical scheme adopted for classification. Indeed, a contradiction appears when we first classify mineral species to form classes (based on their chemistry) and subsequently we group together them to form supergroups (based on their structure topology): To date, more than half of recognized mineral supergroups include species with different anions or anionic complexes. This observation is in contrast to the current use of chemical composition as the distinguishing factor at the highest level of mineral classification.

scholarly journals On the application of the IMA−CNMNC dominant-valency rule to complex mineral compositions

2019 ◽  
Vol 83 (5) ◽  
pp. 627-632 ◽  
Author(s):  
Ferdinando Bosi ◽  
Frédéric Hatert ◽  
Ulf Hålenius ◽  
Marco Pasero ◽  
Ritsuro Miyawaki ◽  
...  
Keyword(s):  
Critical Point ◽  
Single Site ◽  
Mineral Species ◽  
Total Charge ◽  
Heterovalent Substitution ◽  
Simple Application ◽  
Mineral Compositions ◽  
Mineral Identification ◽  
Dominant Root

AbstractMineral species should be identified by an end-member formula and by using the dominant-valency rule as recommended by the IMA–CNMNC. However, the dominant-end-member approach has also been used in the literature. These two approaches generally converge, but for some intermediate compositions, significant differences between the dominant-valency rule and the dominant end-member approach can be observed. As demonstrated for garnet-supergroup minerals, for example, the end-member approach is ambiguous, as end-member proportions strongly depend on the calculation sequence. For this reason, the IMA–CNMNC strongly recommends the use of the dominant-valency rule for mineral nomenclature, because it alone may lead to unambiguous mineral identification. Although the simple application of the dominant-valency rule is successful for the identification of many mineral compositions, sometimes it leads to unbalanced end-member formulae, due to the occurrence of a coupled heterovalent substitution at two sites along with a heterovalent substitution at a single site. In these cases, it may be useful to use the site-total-charge approach to identify the dominant root-charge arrangement on which to apply the dominant-constituent rule. The dominant-valency rule and the site-total-charge approach may be considered two procedures complementary to each other for mineral identification. Their critical point is to find the most appropriate root-charge and atomic arrangements consistent with the overriding condition dictated by the end-member formula. These procedures were approved by the IMA−CNMNC in May 2019.

PETROGRAPHY, MINERAL CHEMISTRY AND CLASSIFICATION OF SOME GROVE MOUNTAINS METEORITES

2014 ◽  
Vol 25 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Shijie Li ◽  
Shijie Wang ◽  
Shen Liu ◽  
Xiongyao Li ◽  
Yang Li ◽  
...  
Keyword(s):  
Mineral Chemistry ◽  
Grove Mountains

Hierarchical Scheme for Vehicle Make and Model Recognition

2021 ◽  
pp. 036119812110197
Author(s):  
Chaoqing Wang ◽  
Junlong Cheng ◽  
Yuefei Wang ◽  
Yurong Qian
Keyword(s):  
Intelligent Transportation Systems ◽  
Recognition Accuracy ◽  
Transportation Systems ◽  
Feature Descriptor ◽  
Vehicle Recognition ◽  
Public Dataset ◽  
Classification Of Images ◽  
Model Recognition ◽  
Hierarchical Scheme

A vehicle make and model recognition (VMMR) system is a common requirement in the field of intelligent transportation systems (ITS). However, it is a challenging task because of the subtle differences between vehicle categories. In this paper, we propose a hierarchical scheme for VMMR. Specifically, the scheme consists of (1) a feature extraction framework called weighted mask hierarchical bilinear pooling (WMHBP) based on hierarchical bilinear pooling (HBP) which weakens the influence of invalid background regions by generating a weighted mask while extracting features from discriminative regions to form a more robust feature descriptor; (2) a hierarchical loss function that can learn the appearance differences between vehicle brands, and enhance vehicle recognition accuracy; (3) collection of vehicle images from the Internet and classification of images with hierarchical labels to augment data for solving the problem of insufficient data and low picture resolution and improving the model’s generalization ability and robustness. We evaluate the proposed framework for accuracy and real-time performance and the experiment results indicate a recognition accuracy of 95.1% and an FPS (frames per second) of 107 for the framework for the Stanford Cars public dataset, which demonstrates the superiority of the method and its availability for ITS.

Crystal chemistry and nomenclature of rhodonite-group minerals

2019 ◽  
Vol 83 (6) ◽  
pp. 829-835 ◽  
Author(s):  
Nadezhda V. Shchipalkina ◽  
Igor V. Pekov ◽  
Nikita V. Chukanov ◽  
Cristian Biagioni ◽  
Marco Pasero
Keyword(s):  
Crystal Chemistry ◽  
Structural Formula ◽  
Structure Type ◽  
Mineral Species ◽  
Triclinic Space Group ◽  
Space Group ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
General Chemical

AbstractThis paper presents the nomenclature of the rhodonite group accepted by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA). An overview of the previous studies of triclinic (space group P$\bar{1}$) pyroxenoids belonging to the rhodonite structure type, with a focus on their crystal chemistry, is given. These minerals have the general structural formula VIIM(5)VIM(1)VIM(2)VIM(3)VIM(4)[Si5O15]. The following dominant cations at the M sites are known at present: M(5) = Ca or Mn2+, M(1–3) = Mn2+; and M(4) = Mn2+ or Fe2+. In accordance with the nomenclature, the rhodonite group consists of three IMA-approved mineral species having the following the general chemical formulae: M(5)AM(1–3)B3M(4)C[Si5O15], where A = Ca or Mn2+; B = Mn2+; and C = Mn2+ or Fe2+. The end-member formulae of approved rhodonite-group minerals are as follows: rhodonite CaMn3Mn[Si5O15]; ferrorhodonite CaMn3Fe[Si5O15]; and vittinkiite MnMn3Mn[Si5O15].

scholarly journals Topology-based classification of tetrads and quadruplex structures

2019 ◽  
Vol 36 (4) ◽  
pp. 1129-1134 ◽  
Author(s):  
Mariusz Popenda ◽  
Joanna Miskiewicz ◽  
Joanna Sarzynska ◽  
Tomasz Zok ◽  
Marta Szachniuk
Keyword(s):  
Nucleic Acid ◽  
3D Structure ◽  
Data Bank ◽  
Supplementary Information ◽  
The Novel ◽  
Disease Treatment ◽  
Structure Topology ◽  
Secondary Structure Topology ◽  
Nucleic Acid Structures

Abstract Motivation Quadruplexes attract the attention of researchers from many fields of bio-science. Due to a specific structure, these tertiary motifs are involved in various biological processes. They are also promising therapeutic targets in many strategies of drug development, including anticancer and neurological disease treatment. The uniqueness and diversity of their forms cause that quadruplexes show great potential in novel biological applications. The existing approaches for quadruplex analysis are based on sequence or 3D structure features and address canonical motifs only. Results In our study, we analyzed tetrads and quadruplexes contained in nucleic acid molecules deposited in Protein Data Bank. Focusing on their secondary structure topology, we adjusted its graphical diagram and proposed new dot-bracket and arc representations. We defined the novel classification of these motifs. It can handle both canonical and non-canonical cases. Based on this new taxonomy, we implemented a method that automatically recognizes the types of tetrads and quadruplexes occurring as unimolecular structures. Finally, we conducted a statistical analysis of these motifs found in experimentally determined nucleic acid structures in relation to the new classification. Availability and implementation https://github.com/tzok/eltetrado/ Supplementary information Supplementary data are available at Bioinformatics online.

Clay minerals and bauxitic minerals. A review and classification based on a statistical method

1933 ◽  
Vol 23 (143) ◽  
pp. 463-482 ◽  
Author(s):  
S. I. Tomkeieff
Keyword(s):  
Statistical Method ◽  
Clay Minerals ◽  
Statistical Study ◽  
Mineral Species ◽  
Hydration Products ◽  
Other Substances ◽  
Image Position ◽  
Aluminium Silicates ◽  
Frequency Curves

SummaryA statistical study of clay and bauxitic minerals, which consisted of plotting all available analyses of these minerals on two triangular diagrams (figs. 1 and 7) and constructing frequency curves for the cardinal ratios, led to a classification of these minerals on a purely chemical basis. The suggestion is also made that among substances claimed to be minerals we can select only a few as belonging to definite mineral species, and that the others are probably mixtures of these selected minerals, or their hydration products, or colloidal hydrates of variable composition. The distinct crystalline mineral species thus singled out are as follows :Besides these minerals, other substances, such as termierite, anauxite, allophane, &c., are suggested as probable species, without, however, any clear statistical evidence. The bentonitic minerals, not belonging strictly to the pure hydrous aluminium silicates, are placed in a separate group.In conclusion, I should like to thank Dr. G. Hickling and Mr. G. S. Mockler for reading the MS. of this paper and for their valuable suggestions.

Biogeography of Modern Benthic Foraminifera

1982 ◽  
Vol 6 ◽  
pp. 90-106
Author(s):  
Martin A. Buzas ◽  
Stephen J. Culver
Keyword(s):  
Benthic Foraminifera ◽  
Large Area ◽  
Space And Time ◽  
Patterns Of Distribution ◽  
The Earth ◽  
Current Classification ◽  
A Current ◽  
Hierarchical Scheme

Biogeography is concerned with recording and explaining the distribution of organisms in space and time. In their search for patterns of distribution, biogeographers have classified the surface of the earth into a hierarchical scheme of ecological units (e.g. Kauffman and Scott, 1976). The basic biogeographic units are realms and provinces. A faunal realm is a large area about the size of a continent while provinces are subdivisions within a realm. An appreciation of the scale involved is gained by considering a current classification of the terrestial world (Udvardy, 1975) which contains 8 realms and 172 provinces.

The Mineral Chemistry and Classification of New Ordinary Chondrites Collected in Antarctica

2012 ◽  
Vol 621 ◽  
pp. 125-129
Author(s):  
Bao Hua Wang ◽  
Shi Jie Li ◽  
Bing Kui Miao
Keyword(s):  
High Pressure ◽  
Mineral Chemistry ◽  
Shock Metamorphism ◽  
Ordinary Chondrites ◽  
Similar Composition ◽  
Severe Shock ◽  
Grove Mountains

Petrography and mineral chemistry of ninety-eight ordinary chondrites from Grove Mountains, Antarctica, have been studied, in order to assign their chemical-petrographic types. The chemical-petrographic types of these meteorites are presented below: 36 H-groups (21 H4, 9 H5, 6 H6) and 62 L-groups (25 L5, 37 L6). The compositions of olivines and low-Ca pyroxenes in the all these ordinary chondrites have similar composition, respectively, reflecting some degree thermodynamics equilibration in them. The weathering degrees of all the ordinary chondrites, consisting of predominant weathering degrees of W1, suggest lightly weathered among them. More than 30% meteorites experienced severe shock metamorphism, as indicated by the presences of shock-induced melt veins and pockets. These heavily shocked meteorites provide us with natural samples for study of high-pressure polymorphs of minerals.

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