GEOLOGICAL AND GENETIC FEATURES CHAMBER PEGMATITES

Author(s):  
Sofia Borisovna Pavlidis ◽  

This article is devoted to the analysis of the genetic features of chamber pegmatites of Volyn. The author dwells in detail on their mineral composition, describes the connection of pegmatites with containing rocks. Special attention in the work is paid to pegmatite formation, the stages of formation of chamber pegmatites.

2015 ◽  
Vol 21 ◽  
pp. 222
Author(s):  
Mohammed Ahmed ◽  
Abdulrahman Alkabbani ◽  
Tarek Amin ◽  
Hindi Alhindi

Crisis ◽  
2012 ◽  
Vol 33 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Carolyn M. Wilson ◽  
Bruce K. Christensen

Background: Our laboratory recently confronted this issue while conducting research with undergraduate students at the University of Waterloo (UW). Although our main objective was to examine cognitive and genetic features of individuals with schizotypal personality disorder (SPD), the study protocol also entailed the completion of various self-report measures to identify participants deemed at increased risk for suicide. Aims and Methods: This paper seeks to review and discuss the relevant ethical guidelines and legislation that bear upon a psychologist’s obligation to further assess and intervene when research participants reveal that they are at increased risk for suicide. Results and Conclusions: In the current paper we argue that psychologists are ethically impelled to assess and appropriately intervene in cases of suicide risk, even when such risk is revealed within a research context. We also discuss how any such obligation may potentially be modulated by the research participant’s expectations of the role of a psychologist, within such a context. Although the focus of the current paper is on the ethical obligations of psychologists, specifically those practicing within Canada, the relevance of this paper extends to all regulated health professionals conducting research in nonclinical settings.


2019 ◽  
Author(s):  
T Goschzik ◽  
E Dörner ◽  
A zur Mühlen ◽  
T Pietsch
Keyword(s):  

Author(s):  
D. A. Petrochenkov

Fossils of marine reptiles are a new jewelry and ornamental material and collected in the Ulyanovsk region from the Upper Jurassic deposits. They consist of (wt. %): calcite — 52, apatite — 24 and pyrite — 23, and also gypsum presents. The contents of radioactive and carcinogenic elements are close to background. The original bone structure of reptiles is preserved. Apatite replaces the bone tissue of marine reptiles, forming a cellular framework. According to the chemical composition, apatite refers to fluorohydroxyapatite with an increased Sr content. The size of the crystals is finely-dispersed. Calcite and pyrite fill the central parts of the cells. Calcite crystals of isometric and elongated shape, 0,01—0,05 mm in size, form blocks up to 0,3 mm during intergrowth. Calcite fills thin, discontinuous veins along the contour of cells with a width of up to 0,03 mm. In calcite, among the impurity elements, there are (wt. %, on the average): Mg — 0,30, Mn — 0,39 and Fe — 0,96. Pyrite forms a dispersed impregnation in calcite and apatite, content of impurities is, wt. %: Ni — up to 0,96 and Cu — up to 0,24. On technological and decorative characteristics of fossils of sea reptiles of Ulyanovsk region are qualitative jewelry and ornamental materials of biomineral group, allowing to make a wide assortment of jewelry and souvenir products.


Fitoterapia ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 55-57
Author(s):  
L. I. Pohodina ◽  
◽  
N. Ye. Burda ◽  
V. S. Kyslychenko ◽  
A. A. Voloshyna ◽  
...  
Keyword(s):  

The article presents the study of processes of structure formation of cement stone and products of hardening of organic-mineral compositions with fibrous filler (shavings) by the electronic scanning microscopy method. It is established that the additive-free cement stone at the age of 28 days has a dense and homogeneous structure, consists of calcium hydro-silicates, Portlandite and calcite - newgrowths characteristic for cement systems. Cellulose fibers, which make up the bulk of the substance of shavings, are sufficiently active, which determines the high adhesion of the hydration products of the cement binder to their surface. It is shown that the introduction of shavings into the organo-mineral composition leads to inhibition of cement hydration processes. Organo-mineral compositions with different shavings content (two compositions) were analyzed. The first composition is characterized by a fairly dense structure, the cement stone consists of globular nanoscale nuclei of hydrosilicates, Portlandite and calcite. The second composition has a loose porous structure, cement stone consists of non-hydrated cement grains, newgrowths are represented by calcite and vaterite. The structure of the contact zone "osprey fiber-cement stone" in the organo-mineral composition of the first composition indicates a good adhesion of the filler surface with the phases of hydrated cement. The use of shavings as a fibrous filler (the first composition) increases the tensile and bending strength, as well as the wear resistance of organo-mineral compositions. The data obtained by scanning electron microscopy are confirmed by the results of studying the processes of structure formation of cement stone by quantitative x-ray phase analysis.


Sign in / Sign up

Export Citation Format

Share Document