Use of the 40Ar39Ar stepwise heating method for dating mylonite zones: An example from the St. Barthélémy Massif (Northern Pyrenees, France)

Ion cyclotron range of frequencies (ICRF) heating will be the sole auxiliary heating method on SPARC for both full-field (Bt0 ~ 12 T) D–T operation and reduced field (Bt0 ~ 8 T) D–D operation. Using the fast wave at ~120 MHz, good wave penetration and strong single-pass absorption is expected for D–T(3He), D(3He), D(H) and 4He(H) heating scenarios. The dependences of wave absorption on ${k_\parallel }$ , 3He concentration, resonance location, antenna poloidal location and losses on alpha particles and ash have been studied. The antenna loading has been assessed by comparison with the Alcator C-Mod antennae. An antenna spectrum of ${k_\parallel }\sim 15\text{--}18\,{\textrm{m}^{ - 1}}$ is shown to be good for both core absorption and edge coupling. For the control of impurity sources, the antenna straps are rotated ~10° to be perpendicular to the B field and the straps can run with different power levels in order to optimize the antenna spectrum and to minimize the image current on the antenna frame. Combining the physics constraints with the SPARC port design, maintenance requirement and contingency against antenna failure during D–T operation, we plan to mount on the inner wall of the vacuum vessel a total of 12 4-strap antennae in 6 ports while keeping 3-strap antennae that are insertable and removable on port plugs as the backup option.

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Comparative study of conventional and microwave heating of polyacrylonitrile-based fibres

Journal of Polymer Engineering ◽

10.1515/polyeng-2020-0167 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Guozhen Zhao ◽

Jianhua Liu ◽

Lei Xu ◽

Shenghui Guo

Keyword(s):

Microwave Heating ◽

Surface Defects ◽

Energy Dispersive Spectrometer ◽

Xrd Analysis ◽

Economic Benefits ◽

Heating Time ◽

Oxidation Temperature ◽

Conventional Heating ◽

Heating Method ◽

Molecular Arrangement

Abstract The effects of the conventional heating method and the microwave heating method on polyacrylonitrile-based fibres in the temperature range of 180–280 °C were investigated. Fourier transform infrared spectroscopy, X-ray wide-angle scattering, Raman spectroscopy, energy-dispersive spectrometer, scanning electron microscopy and bulk density were used to characterise the properties of the samples. Results show that the microwave heating method can shorten the pre-oxidation time, reduce pre-oxidation temperature and reduce the number of surface defects. The pre-oxidised fibres obtained by the microwave heating method exhibit not only good crystallite size but also a smooth surface. Atomic morphology and molecular arrangement are orderly inside the fibre. The FT-IR spectrum shows that the oxidation reaction occurs at 220 °C, and the CI value of PAN fibers stabilised by microwave heating is the larger than the fibers stabilised by conventional heating. XRD analysis shows that fibers stabilised by microwave heating have low stack domains. The SEM and Raman spectra indicate that hydrogen peroxide can improve the surface finish of the fibers and reduce defects. Microwave heating can reduce the pre-oxidation temperature by about 20 °C and shorten the heating time. The economic benefits of using this method are significantly improved.

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The Static Mechanical Property of Concrete at Elevated Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.261-263.212 ◽

2011 ◽

Vol 261-263 ◽

pp. 212-216

Author(s):

Jun Lin Tao ◽

Li Bo Qin ◽

Kui Li ◽

Bin Jia

Keyword(s):

Mechanical Property ◽

Elevated Temperature ◽

Room Temperature ◽

Critical Strain ◽

Plain Concrete ◽

Constitutive Relationship ◽

Heating Method ◽

Experiment System ◽

Wave Heating ◽

Static Mechanical

Using micro-wave heating method, the previous disadvantages of heating slowly and non-uniform are broken through. And plain concrete high temperature loading experiment system is composed of the method and material experiment machine. Many experiments of self-made concrete are carried out from room temperature to 600°C by this system. The strength and critical strain of concrete with temperature are obtained, and through analysis of the compressive stress-strain curves under different temperature, the constitutive relationship is established. The result shows that this constitutive relationship is greatly agrees with experiment. Meanwhile, the phenomenon is analyzed and explained in the progress of experiment.

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