Effect of cyclic heat loading on pure tungsten for the ITER divertor

The objective of the present research was to assess the dietary supplementation of three formulations of essential oils (EO) in chickens under heat stress (HS). Day-of-hatch Cobb 500 chicks (n = 500) were randomly distributed into four groups: 1. HS control + control diets; 2. HS + control diets supplemented with 37 ppm EO of Lippia origanoides (LO); 3. HS + control diets supplemented with 45 ppm LO + 45 ppm EO of Rosmarinus officinalis (RO) + 300 ppm red beetroot; 4. HS + 45 ppm LO + 45 ppm RO + 300 ppm natural betaine. Chickens that received the EO showed significant (p < 0.05) improvement on BW, BWG, FI, and FCR compared to control HS chickens. Average body core temperature in group 3 and group 4 was significantly (p < 0.05) reduced compared with the HS control group and group 2. Experimental groups showed a significant reduction in FITC-d at 42 days, a significant increase in SOD at both days but a significant reduction of IFN-γ and IgA compared with HS control (p < 0.05). Bone mineralization was significantly improved by EO treatments (p < 0.05). Together these data suggest that supplemental dietary EO may reduce the harmful effects of HS.

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Characterization and measurement of gamma radiation shielding of a new tungsten-lignin composite

Journal of Composite Materials ◽

10.1177/00219983211029364 ◽

2021 ◽

pp. 002199832110293

Author(s):

Armando Cirilo de Souza ◽

Flavio Aristone ◽

Adriana Fatima Gomes Gouvea ◽

Hedielly Brasil Fernandes ◽

Adailto Miyai ◽

...

Keyword(s):

Gamma Radiation ◽

Kraft Lignin ◽

Temperature Treatment ◽

Radiation Shielding ◽

X Rays ◽

Clear Indication ◽

Pure Tungsten ◽

Metal Organic ◽

Gamma Radiations ◽

Scanning Electron

This research has been carried on to analyze the capability of a new composite to be effectively used as shielding of gamma radiation. The preparation of a metal-organic composite formed by tungsten and Kraft lignin is presented. Samples have been characterized through X-rays and scanning electron microscopy measurements. The results led to the study of the different phase formations. The microscopic analyzes indicate that two different phases are present in the composite. The absence of oxidation in the process even after the temperature treatment imposed to form the sample has also been noticed. Measurements of the attenuation have been performed to study its ability to absorb gamma radiation. A sample of cobalt 60 (Co-60), for which the peak energies are at 1173 keV and 1332 keV, was used as a source of gamma radiation in the experiment of attenuation. The measured attenuation of gamma radiations when the composite is placed to act as a shield is only 16% smaller than the attenuation obtained for standard pure tungsten. This is a clear indication that the new metal-organic composite is suitable for the fabrication of devices dedicated to shielding radiation, with the advantage of being easier to manipulate.

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Laser Powder Bed Fusion Processing of Fe-Mn-Al-Ni Shape Memory Alloy—On the Effect of Elevated Platform Temperatures

Metals ◽

10.3390/met11020185 ◽

2021 ◽

Vol 11 (2) ◽

pp. 185

Author(s):

Felix Clemens Ewald ◽

Florian Brenne ◽

Tobias Gustmann ◽

Malte Vollmer ◽

Philipp Krooß ◽

...

Keyword(s):

Heat Treatment ◽

Crack Formation ◽

Microstructural Analysis ◽

Tensile Load ◽

Grain Structure ◽

Powder Bed Fusion ◽

Laser Powder Bed Fusion ◽

Cyclic Heat Treatment ◽

Powder Bed ◽

Cyclic Heat

In order to overcome constraints related to crack formation during additive processing (laser powder bed fusion, L-BPF) of Fe-Mn-Al-Ni, the potential of high-temperature L-PBF processing was investigated in the present study. The effect of the process parameters on crack formation, grain structure, and phase distribution in the as-built condition, as well as in the course of cyclic heat treatment was examined by microstructural analysis. Optimized processing parameters were applied to fabricate cylindrical samples featuring a crack-free and columnar grained microstructure. In the course of cyclic heat treatment, abnormal grain growth (AGG) sets in, eventually promoting the evolution of a bamboo like microstructure. Testing under tensile load revealed a well-defined stress plateau and reversible strains of up to 4%.

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