Geology and base-metal deposits of West Shasta copper-zinc district, Shasta County, California

All that was said so far about passivity and passivation was indeed based on electrochemical prejudgments, and all based on unverified postulates. However, due the authors’ fame and for lack of anything better, the great many contradictions were carefully ignored. However, when resuming from raw experimental facts and the present general knowledge, it now appears that passivation always begins by the precipitation of a metallic hydroxide gel. Therefore, all the protectiveness mechanisms already known for porous corrosion layers apply, so that this outstanding protectiveness is indeed governed by the chemistry of transport processes throughout the entrapped water. For Al type passivation, the base metal ions only have deep and complete electronic shells, which precludes any electronic conductivity. Then protectiveness can only arise from gel thickening and densification. For Fe type passivation, an incomplete shell of superficial 3d electrons allows an early metallic or semimetallic conductivity in the gel skeleton, at the onset of the very first perfectly ordered inorganic polymers (- MII-O-MIII-O-)n. Then all depends on the acquisition, maintenance or loss of a sufficient electrical conductivity in this Faraday cage. But for both types of passive layers, all the known features can be explained by the chemistry of transport processes, with neither exception nor contradiction.

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Concentration of selected micro-nutrients in saliva among women in menopausal period treated with hormone replacement therapy

Osteologie/Osteology ◽

10.1055/s-0038-1630097 ◽

2013 ◽

Vol 22 (01) ◽

pp. 46-51

Author(s):

M. Rahnama ◽

I. Jastrzêbska-Jamrogiewicz ◽

R. Jamrogiewicz

Keyword(s):

Bone Mineral Density ◽

Hormone Replacement Therapy ◽

Blood Serum ◽

Replacement Therapy ◽

Hormone Replacement ◽

Surgical Removal ◽

Femoral Bone ◽

Mineral Density ◽

Natural Menopause ◽

Copper Zinc

Summary Objective: The aim of this study was to observe the variability of the level of copper, zinc and manganese in saliva amongst women with hypoestrogenia, treated and untreated with hormone replacement therapy (HRT). Methods: The study was conducted on a group of 60 women treated and untreated with HRT. Half of the patients were after natural menopause and other half was after surgical removal of ovaries. Research on micronutrients in non-stimulated saliva and blood serum was carried out in 2005. Tests on saliva were repeated in 2010. Investigation of bone mineral density (BMD) of femoral bone was performed in year 2010. Results: Statistical analysis of concentration of copper and zinc revealed a linear correlation between the levels of these microelements in blood serum and saliva. The study revealed that HRT has a beneficial effect on BMD and the concentration of copper and manganese in saliva and blood serum of patients after the menopause. Patients treated with HRT showed higher BMD values than groups not treated with hormones. Conclusions: Saliva appears to be a promising diagnostic material which can be used to analyze the content of trace elements, but further research should be carried out on a broader research group.

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Base Metal Sulfide Deposits in Sedimentary and Volcanic Environments

10.1007/978-3-662-02538-3 ◽

1988 ◽

Keyword(s):

Base Metal ◽

Metal Sulfide ◽

Base Metal Sulfide ◽

Sulfide Deposits

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Brahmi legends on Umayyad Fulus: Interrogating local minting practices and numismatic transculturation in Gandhara (ca. 750 CE)

Afghanistan ◽

10.3366/afg.2019.0029 ◽

2019 ◽

Vol 2 (1) ◽

pp. 153-165

Author(s):

Waleed Ziad

Keyword(s):

Base Metal ◽

Late Antiquity ◽

Eighth Century ◽

Political Authority ◽

Unusual Feature ◽

Complex Relationship ◽

Contact Zones ◽

Confessional Identity ◽

Derivatives Of

This paper concerns a historically significant find of copper derivatives of Umayyad post-reform fulus from Gandhara, probably minted in the mid-eighth century under Turk Shahi sovereignty (c. 667–875). The coins share an unusual feature: two Brahmi aksharas on an Umayyad AE prototype, inversely oriented to a partially-corrupted Arabic legend. These base metal coins represent perhaps the only known caliphal imitative varieties issued by moneyers beyond the eastern limits of Umayyad and Abbasid sovereignty. They have the potential to inform our understanding of the complex relationship between political authority, confessional identity, and coin typology in late antiquity – particularly within early “Hindu”– “Muslim” contact zones. Moreover, they provide invaluable clues into the circulatory regimes of Umayyad coinage.

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