An X-ray examination of some potash-soda-felspars

1939 ◽  
Vol 25 (165) ◽  
pp. 338-350 ◽  
Author(s):  
S. H. Chao ◽  
D. L. Smare ◽  
W. H. Taylor
Keyword(s):  
Systematic Classification ◽  
X Ray ◽  
Natural Minerals ◽  
Thermal Investigations ◽  
Potash Felspar ◽  
Complete Survey ◽  
The Subject ◽  
First Time ◽  
Ray Methods

The systematic classification of the potash-soda-felspars is of the greatest interest and importance to the mineralogist, but problems demanding physical investigation are raised in work carried out recently by Dr. Edmondson Spencer, who has described the results of exhaustive chemical, optical, and thermal investigations of a representative collection of these minerals. Dr. Spencer has very kindly allowed us to examine by X-ray methods a large number of his specimens, so that for the first time it has been possible to make a fairly complete survey of potash-soda-felspars of known chemical composition and with accurately measured optical properties.This paper presents the results of our general survey of potash-soda-felspars with compositions ranging from nearly pure potash-felspar to approximately 50 % soda-felspar. The natural minerals, and the same minerals after specified heat-treatment, have been examined. We do not discuss in detail the interpretation of our results in terms of the atomic structure of felspars; the subject is extremely complicated, and it is necessary to await the results of other investigations now in progress in this laboratory before attempting a complete structural interpretation.

СОЦИАЛЬНАЯ КОНФЛИКТОЛОГИЯ: ТЕОРЕТИКО-ИСТОРИЧЕСКИЙ АСПЕКТ

2020 ◽  
Vol 15 (2) ◽  
pp. 68
Author(s):  
А. Н. Сухов
Keyword(s):  
Theory And Practice ◽  
Important Task ◽  
Social Conflicts ◽  
Psychological Approach ◽  
Structure Dynamics ◽  
History Of ◽  
The Subject ◽  
First Time

This given article reveals the topicality not only of destructive, but also of constructive, as well as hybrid conflicts. Practically it has been done for the first time. It also describes the history of the formation of both foreign and domestic social conflictology. At the same time, the chronology of the development of the latter is restored and presented objectively, in full, taking into account the contribution of those researchers who actually stood at its origins. The article deals with the essence of the socio-psychological approach to understanding conflicts. The subject of social conflictology includes the regularities of their occurrence and manifestation at various levels, spheres and conditions, including normal, complicated and extreme ones. Social conflictology includes the theory and practice of diagnosing, resolving, and resolving social conflicts. It analyzes the difficulties that occur in defining the concept, structure, dynamics, and classification of social conflicts. Therefore, it is no accident that the most important task is to create a full-fledged theory of social conflicts. Without this, it is impossible to talk about effective settlement and resolution of social conflicts. Social conflictology is an integral part of conflictology. There is still a lot of work to be done, both in theory and in application, for its complete design. At present, there is an urgent need to develop conflict-related competence not only of professionals, but also for various groups of the population.

New Principles of the Substructure Development in Metal Materials under Plastic Deformation, Revealed by Advanced X-Ray Methods

2004 ◽  
Vol 443-444 ◽  
pp. 259-262 ◽  
Author(s):  
Yuriy Perlovich ◽  
Margarita Isaenkova
Keyword(s):  
Wide Spectrum ◽  
Residual Deformation ◽  
Ray Method ◽  
Computer Data ◽  
Rolled Material ◽  
X Ray ◽  
Pole Figures ◽  
Metal Materials ◽  
First Time ◽  
Ray Methods

The substructure inhomogeneity of real textured metal materials was studied by use of the X-ray method of Generalized Pole Figures and the computer data treatment. Main regularities of substructure inhomogeneity were revealed for the first time. Substructure conditions of grains in rolled material form an extremely wide spectrum and vary by passing from texture maxima to texture minima, where residual deformation effects are most significant. The distribution of residual elastic microstrains in the orientational space of rolled material shows the distinct system.

scholarly journals Exploiting superspace to clarify vacancy and Al/Si ordering in mullite

IUCrJ ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 497-509 ◽  
Author(s):  
Paul Benjamin Klar ◽  
Iñigo Etxebarria ◽  
Gotzon Madariaga
Keyword(s):  
Density Functional ◽  
X Ray Diffraction ◽  
Intrinsic Structure ◽  
Functional Theory ◽  
New Approach ◽  
X Ray ◽  
Vacancy Ordering ◽  
Harmonic Modulation ◽  
First Time

Synchrotron single-crystal X-ray diffraction has revealed diffuse scattering alongside sharp satellite reflections for different samples of mullite (Al4+2xSi2−2xO10−x). Structural models have been developed in (3+1)-dimensional superspace that account for vacancy ordering and Al/Si ordering based on harmonic modulation functions. A constraint scheme is presented which explains the crystal-chemical relationships between the split sites of the average structure. The modulation amplitudes of the refinements differ significantly by a factor of ∼3, which is explained in terms of different degrees of ordering,i.e.vacancies follow the same ordering principle in all samples but to different extents. A new approach is applied for the first time to determine Al/Si ordering by combining density functional theory with the modulated volumes of the tetrahedra. The presence of Si–Si diclusters indicates that the mineral classification of mullite needs to be reviewed. A description of the crystal structure of mullite must consider both the chemical composition and the degree of ordering. This is of particular importance for applications such as advanced ceramics, because the physical properties depend on the intrinsic structure of mullite.

scholarly journals NuSTAR reveals that the heavily obscured nucleus of NGC 2785 was the contaminant of IRAS 09104+4109 in the BeppoSAX/PDS hard X-rays

2018 ◽  
Vol 619 ◽  
pp. A16
Author(s):  
C. Vignali ◽  
P. Severgnini ◽  
E. Piconcelli ◽  
G. Lanzuisi ◽  
R. Gilli ◽  
...  
Keyword(s):  
X Rays ◽  
X Ray ◽  
Star Forming ◽  
Physical Description ◽  
Enhanced Sensitivity ◽  
X Ray Imaging ◽  
First Time ◽  
In Virtue Of

Context. The search for heavily obscured active galactic nuclei has been revitalized in the last five years by NuSTAR, which has provided a good census and spectral characterization of a population of such objects, mostly at low redshift, thanks to its enhanced sensitivity above 10 keV compared to previous X-ray facilities, and its hard X-ray imaging capabilities. Aims. We aim at demonstrating how NGC 2785, a local (z = 0.009) star-forming galaxy, is responsible, in virtue of its heavily obscured active nucleus, for significant contamination in the non-imaging BeppoSAX/PDS data of the relatively nearby (≈17′) quasar IRAS 09104+4109 (z = 0.44), which was originally mis-classified as Compton thick. Methods. We analyzed ≈71 ks NuSTAR data of NGC 2785 using the MYTorus model and provided a physical description of the X-ray properties of the source for the first time. Results. We found that NGC 2785 hosts a heavily obscured (NH ≈ 3 × 1024 cm−2) nucleus. The intrinsic X-ray luminosity of the source, once corrected for the measured obscuration (L2−10keV ≈ 1042 erg s−1), is consistent within a factor of a few with predictions based on the source mid-infrared flux using widely adopted correlations from the literature. Conclusions. Based on NuSTAR data and previous indications from the Neil Gehrels Swift Observatory (BAT instrument), we confirm that NGC 2785, because of its hard X-ray emission and spectral shape, was responsible for at least one third of the 20–100 keV emission observed using the PDS instrument onboard BeppoSAX, originally completely associated with IRAS 09104+4109. Such emission led to the erroneous classification of this source as a Compton-thick quasar, while it is now recognized as Compton thin.

scholarly journals Ba2ZnGe2S6O: Ein neues Oxidsulfid mit Tetraedergerüststruktur/On Ba2ZnGe2S6O. A New Oxide Sulfide with Tetrahedral Framework Structure

1980 ◽  
Vol 35 (6) ◽  
pp. 672-675 ◽  
Author(s):  
Chr. L. Teske
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Coordination Sphere ◽  
Framework Structure ◽  
Tetrahedral Framework ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
First Time ◽  
Ray Methods

Abstract Ba2ZnGe2S6O was prepared for the first time and the crystal structure determined by using single crystal X-ray methods. The space group is D32d-P4̄21m, tetragonal (No. 113). Lattice constants: a = 963.59 ± 0.22; c = 645.06 ± 0.25 pm. The tetrahedral framework structure is described and discussed. Zn is linked only to sulfur. The oxygen belongs to the coordination sphere of Ge and Ba.

The Cochlostoma (Holcopoma) westerlundi group in Italy (Caenogastropoda: Cochlostomatidae)

Biologia ◽  
2014 ◽  
Vol 69 (6) ◽  
Author(s):  
Mariastella Colomba ◽  
Fabio Liberto ◽  
Armando Gregorini ◽  
Walter Renda ◽  
Agatino Reitano ◽  
...  
Keyword(s):  
16S Rdna ◽  
Southern Italy ◽  
Genetic Distances ◽  
Morphological Data ◽  
Molecular Evidence ◽  
Systematic Classification ◽  
Phylogenetic Status ◽  
First Time ◽  
Reproductive Apparatus

AbstractCurrently, the Cochlostoma (Holcopoma) westerlundi (Paulucci, 1879) group includes three subspecies inhabiting southern Italy up to southeastern Sicily. C. w. westerlundi (Paulucci, 1879) is limited to southern Calabria, C. w. yapigium (Westerlund, 1885) is widespread across the Salento (the southeastern extremity of the Apulia region) and C. w. dionysii (Paulucci, 1879) is endemic to the environs of Siracusa (SE Sicily). There is also a fourth taxon, C. paganum (Westerlund, 1885) described for Otranto (LE, Apulia), considered a synonym of C. w. yapigium. Up to now, the molecular genetics of C. westerlundi s.l. have been unknown and the morphological data of several populations are still lacking. Hence, the systematic classification of the group is tentative. Aiming at filling this gap, mtDNA (16S rDNA and COI) partial sequences were investigated and, in addition, the reproductive apparatus of C. w. westerlundi was described for the first time. Molecular sequences and anatomical data were used to test the taxonomic and phylogenetic status of the examined populations. Maximum Likelihood and Bayesian analysis revealed three clusters, strongly supported, corresponding to the three taxa. For the first time, synonymy between paganum and yapigium was confirmed by molecular evidence. Genetic distances between groups (DxyJC) ranged from 2.6% to 5% (16S rDNA) and from 6.3% to 8.3% (COI). Molecular and morphological data led us to suggest elevating the three subspecies to the species rank.

X.—Other Dialectal Forms in Tennessee

PMLA ◽  
1891 ◽  
Vol 6 (3-4) ◽  
pp. 171-175 ◽  
Author(s):  
Calvin S. Brown
Keyword(s):  
The Other ◽  
The South ◽  
Modern Language ◽  
Other Hand ◽  
Trace Back ◽  
Complete Survey ◽  
The Subject ◽  
The One

The subject of this paper as announced some time ago in the programme of this convention, is not exactly the one which it should bear. In a former paper, published in the Modern Language Notes, I tried to trace back a number of our peculiar words and speech usages to an earlier period of the language, using Shakespeare as a basis. In the present paper this method of procedure has been attempted only incidentally. In other words, I invite your attention to a study of a few of the peculiarities of the language as found in Tennessee, regardless of their origin and history. It is not to be supposed, however, that the forms pointed out are limited to one particular state or to a small territory. On the other hand, most of them are found throughout the larger portion of the South, and many of them are common over the whole country. Nothing like a complete survey of the field, or a strict classification of the material gathered, has been attempted, and many of the words treated have been discussed by others. A few cases of bad pronunciation have been noticed, rather as an index of characteristic custom than as showing anything new.

scholarly journals A variable-frequency HFQPO in GRS 1915+105 as observed with AstroSat

2019 ◽  
Vol 489 (1) ◽  
pp. 1037-1043 ◽  
Author(s):  
Tomaso M Belloni ◽  
Dipankar Bhattacharya ◽  
Pietro Caccese ◽  
Varun Bhalerao ◽  
Santosh Vadawale ◽  
...  
Keyword(s):  
Periodic Oscillation ◽  
Large Area ◽  
Quasi Periodic Oscillation ◽  
X Ray ◽  
Phase Lags ◽  
Time Variations ◽  
Area X ◽  
First Time ◽  
Observation Period

ABSTRACT From the analysis of more than 92 ks of data obtained with the Large Area X-Ray Proportional Counter (LAXPC) instrument onboard AstroSat we have detected a clear high-frequency quasi-periodic oscillation (HFQPO) whose frequency varies between 67.4 and 72.3 Hz. In the classification of variability classes of GRS 1915+105, at the start of the observation period the source was in class ω and at the end the variability was that of class μ: both classes are characterized by the absence of hard intervals and correspond to disc-dominated spectra. After normalization to take into account time variations of the spectral properties as measured by X-ray hardness, the QPO centroid frequency is observed to vary along the hardness–intensity diagram, increasing with hardness. We also measure phase lags that indicate that HFQPO variability at high energies lags that at lower energies and detect systematic variations with the position on the hardness–intensity diagram. This is the first time that (small) variations of the HFQPO frequency and lags are observed to correlate with other properties of the source. We discuss the results in the framework of existing models, although the small (7 per cent) variability observed is too small to draw firm conclusions.

scholarly journals X-Ray studies of the structure of hair, wool, and related fibres. II.- the molecular structure and elastic properties of hair keratin

1933 ◽  
Vol 232 (707-720) ◽  
pp. 333-394 ◽  
Keyword(s):  
Molecular Structure ◽  
Elastic Properties ◽  
Historical Development ◽  
Complex Nature ◽  
X Ray ◽  
Hair Keratin ◽  
Structural Principles ◽  
Series Of Experiments ◽  
The Subject ◽  
Ray Methods

In a previous communication* an account was given of a preliminary exploration, chiefly by X-ray methods, of the problem of the molecular structure of animal hairs. The present paper is a natural continuation of the record, in which earlier tentative suggestions are either confirmed or rejected, and an attempt is made to lay bare the general structural principles underlying the properties of the protein, keratin . It will be unnecessary here to outline once more the historical development of the subject; we shall proceed at once to the main point of this introductory section, which is to give what appears to be the solution of the problem before setting out in detail the experimental facts and arguments leading up to it. Such a procedure is advisable because of the complex nature of the properties under discussion ; such a long series of experiments have been involved in their elucidation, that without some sort of preliminary statement of the chief conclusions, the issue is apt to grow confused.

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