The Wasp as Terrestrial Indicator of Environmental Metal Composition: Evidence from Zimbabwe

Immobilization of two single transition metal (TM) atoms on a substrate host opens numerous possibilities for catalyst design. If the substrate contains more than one vacancy site, the combination of TMs along with their distribution patterns becomes a design parameter potentially complementary to the substrate itself and the bi-metal composition. By means of DFT calculations, we modeled three dissimilar bi-metal atoms (Ti, Mn, and Cu) doped into the six porphyrin-like cavities of porous C24N24 fullerene, considering different bi-metal distribution patterns for each binary complex, viz. TixCuz@C24N24, TixMny@C24N24, and MnyCuz@C24N24 (with x, y, z = 0–6). We elucidate whether controlling the distribution of bi-metal atoms into the C24N24 cavities can alter their catalytic activity toward CO2, NO2, H2, and N2 gas capture. Interestingly, Ti2Mn4@C24N24 and Ti2Cu4@C24N24 complexes showed the highest activity and selectively toward gas capture. Our findings provide useful information for further design of novel few-atom carbon-nitride-based catalysts.

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Dynamic fracture toughness (JId) behavior of armor-grade Q&T steel weldments: Effect of weld metal composition and microstructure

Metals and Materials International ◽

10.1007/s12540-009-1017-4 ◽

2009 ◽

Vol 15 (6) ◽

pp. 1017-1026 ◽

Cited By ~ 5

Author(s):

Govindaraj Magudeeswaran ◽

Visvalingam Balasubramanian ◽

S. Sathyanarayanan ◽

Gankidi Madhusudhan Reddy ◽

A. Moitra ◽

...

Keyword(s):

Fracture Toughness ◽

Weld Metal ◽

Dynamic Fracture ◽

Dynamic Fracture Toughness ◽

Metal Composition ◽

Weld Metal Composition

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Controlled atmosphere GMAW welding of transportation vehicles and production machines parts made from 30MnB5 steel

MATEC Web of Conferences ◽

10.1051/matecconf/201821603001 ◽

2018 ◽

Vol 216 ◽

pp. 03001 ◽

Cited By ~ 1

Author(s):

Evgeny Ivanayskiy ◽

Aleksei Ishkov ◽

Aleksandr Ivanayskiy ◽

Iakov Ochakovskii

Keyword(s):

Mechanical Properties ◽

Carbon Dioxide ◽

Carbon Monoxide ◽

Chemical Composition ◽

Controlled Atmosphere ◽

Shielding Gas ◽

Reducing Atmosphere ◽

Metal Composition ◽

Gmaw Welding ◽

Welding Materials

The paper studies the influence of shielding gas on the composition and the structure of weld joint metal of 30MnB5 steel applied in essential parts of automobiles and tractors. The welding was performed in inert, oxidizing and reducing atmospheres. It was established that TIG welding with argon used as shielding gas did not provide the required mechanical properties when using conventional welding materials. Carbon dioxide during MAG welding caused partial burning of alloying elements. Carbon monoxide used as shielding gas was proved to form reducing atmosphere enabling to obtain chemical composition close to the base metal composition. Metallographic examinations were carried out. The obtained results provided full-strength weld, as well as the required reliability and durability of welded components and joints.

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