Authentication and Evaluation of the Technique of Minting the Romanian Coins of the 20th Century. I

2017 ◽  
Vol 68 (9) ◽  
pp. 2155-2159
Author(s):  
Sebastian Laurentiu Marin ◽  
Georgiana Mardare (Balusescu) ◽  
Marius Paduraru ◽  
Claudiu Roman ◽  
Ioan Gabriel Sandu ◽  
...  
Keyword(s):  
20Th Century ◽  
Major Elements ◽  
Raw Material ◽  
Anthropogenic Factors ◽  
Electronic Microscopy ◽  
Elemental Chemical Analysis ◽  
Manufacturing Techniques ◽  
Highly Correlated ◽  
Natural And Anthropogenic Factors ◽  
Origin Area

The present work highlights the results of optical and electronic microscopy analyses performed on fifteen selected outdated 20th century Romanian coins. The obtained results brought significant contributions in establishing specific archaeometric characteristics of corrosion coins products generated within the in-use and demonetization periods, under the action of both natural and anthropogenic factors. The work was mainly aimed in identifying the nature of the alloy and of the raw material used during coins minting, with specific emphasize on their resistance toward the action of various natural and anthropogenic factors. Emphasize is also given to the manufacturing techniques, edition characteristics and the in-use-interval. Performed elemental chemical analysis clearly showed that major elements abundances are highly correlated with coins origin area and their minting period.

Characterization and A Preliminary Study of TiO2 Synthesis from Lampung Iron Sand

2020 ◽  
Vol 849 ◽  
pp. 113-118
Author(s):  
Yayat Iman Supriyatna ◽  
Slamet Sumardi ◽  
Widi Astuti ◽  
Athessia N. Nainggolan ◽  
Ajeng W. Ismail ◽  
...  
Keyword(s):  
Food Packaging ◽  
Xrd Analysis ◽  
Major Elements ◽  
Raw Material ◽  
Solid Residue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Solution ◽  
Ti Content

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.

Daily rhythms in the River Seine: Relative impacts of natural and anthropogenic factors

1991 ◽  
Vol 25 (12) ◽  
pp. 1523-1528 ◽  
Author(s):  
A. Chesterikoff ◽  
B. Garban ◽  
D. Ollivon
Keyword(s):  
Anthropogenic Factors ◽  
Daily Rhythms ◽  
River Seine ◽  
Natural And Anthropogenic Factors

Natural and anthropogenic factors as possible drivers of variability in rocky shore assemblages at multiple spatial scales

2021 ◽  
pp. 107577
Author(s):  
Ivan Monclaro Carneiro ◽  
Iacopo Bertocci ◽  
Paulo César de Paiva ◽  
Maria Teresa Menezes de Széchy
Keyword(s):  
Rocky Shore ◽  
Spatial Scales ◽  
Anthropogenic Factors ◽  
Multiple Spatial Scales ◽  
Natural And Anthropogenic Factors

Phytoplankton of cold-water lake ecosystems under the influence of natural and anthropogenic factors

2021 ◽  
pp. 42-49
Author(s):  
Andrey N. Sharov
Keyword(s):  
Heavy Metals ◽  
Cold Water ◽  
Arctic Lakes ◽  
Water Bodies ◽  
The Arctic ◽  
Anthropogenic Factors ◽  
Large Lakes ◽  
Arctic Water ◽  
The North ◽  
Natural And Anthropogenic Factors

Based on the study of the spatio-temporal aspects of the development of phytoplankton in the lakes of the North and North-West of the European territory of Russia (large lakes – Imandra, Onega and Chudsko-Pskovskoye and small lakes of the Arctic and Subarctic), the features of its structure and dynamics under the influence of natural and anthropogenic factors (eutrophication, heavy metal pollution, acidification, thermification). The species composition and quantitative characteristics of phytoplankton of large lakes of the North of Russia, small arctic lakes and lakes of subarctic regions are studied. It has been shown that diatoms predominate in arctic water bodies according to species diversity, and green and diatoms predominate in boreal ones. By biomass, diatoms dominate mainly in all cold-water lakes, with the exception of small arctic lakes, where golden algae lead. The features of the reorganization of phytoplankton in response to the action of anthropogenic factors are revealed. It is proved that in the northern water bodies the complex action of heavy metals and nutrients does not lead to inhibition of phytoplankton, and the effect of acidification in combination with heavy metals enhances the toxic effect of the latter. A feature of the response to acidification is an increase in the variability of the dynamics of the biomass of phytoplankton. It has been shown that in different types of lakes of East Antarctica under severe climate conditions under light and biogenic limitation, redistribution of autotrophic components in the formation of the biota of water bodies occurs: against the background of a decrease in the abundance and diversity of phytoplankton, the role of microphytobenthos and periphyton increases.

Sign in / Sign up

Export Citation Format

Share Document