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Lead, silver, and antimony
Published in R. F. Tylecote, The Prehistory of Metallurgy in the British Isles, 2017
Soon after the introduction of movable-type printing to Europe in about 1440 the lead-tin-antimony alloys were used as type metal. These were usually tin-rich pewterer’s metal in the early days, but later became lead-rich with about 8% Sb.101
Study of External Source Effects for Different Multibeam Concept for Accelerator-Driven Subcritical Reactor for Nuclear Waste Transmutation (ADS-NWT)
Published in Nuclear Technology, 2022
Zhongliang Lv, Zhong Chen, Zijia Zhao, Dongmei Pan, Lichao Tian, Xiaohu Yang
The basic model and parameters of the single-beam concept for the ADS-NWT are shown in Fig. 1 and Tables I and II (Ref. 15). The side length of a single hexagonal assembly was 10 cm. A homogeneous model with different core zones was built, where the proton beam and the spallation target were in the center of the core, and from the inner circle to the outer circle of the core zone, it was the fuel zone, the reflector, the shielding zone, and the biological shielding zone, respectively. The spallation target was made of lead-bismuth eutectic alloy (LBE), and the fuel was a dispersion-type metal fuel based on zirconium.16 The main composition of the fuel included MAs and plutonium (Pu), which were obtained from the nuclear waste of a common 1000-MW pressurized water reactor.17 The ratio of MAs/Pu was set to 1.1/8.9 to keep the initial keff to 0.98.
Fabrication of a WO3 Conductometric Activated Thin Film Sensor for Resistance-to-frequency Conversion Based Sensing Application
Published in IETE Journal of Research, 2022
Bikram Biswas, Anup Dey, Subhashis Roy, Subir Kumar Sarkar
The MOX based gas sensors were mainly based on the apparent change of the electrical conductivity resulting from adsorption and desorption of gas molecules on the of gas-sensing materials surface. When n-type metal oxides were exposed to air, oxygen molecules, absorbed on its surface, would generate chemisorbed oxygen species (O2−, O−, and O2−) by capturing electrons from its surface and lead to the formation of hole-accumulation layers (HALs) on the surface of materials. The hole- conduction occurred mainly along the near surface HALs, which resulted in the increase of the conductivity. When the gas percentages (%) increases, the reducing gases’ molecules preferred to react with the chemisorbed oxygen species and the hole concentration and hole-accumulation layers decreased, principal to the changing of the conductivity.
Occupational exposure during metal additive manufacturing: A case study of laser powder bed fusion of aluminum alloy
Published in Journal of Occupational and Environmental Hygiene, 2021
Mohamed Nour Azzougagh, Francois-Xavier Keller, Elodie Cabrol, Mehmet Cici, Jeremie Pourchez
During the experimental testing, an aluminum-based alloy-type metal powder was used (AlSi10Mg; Al: bal., Si: 9–11 wt%, Mg: 0.2–0.45 wt%, Fe: <0.55 wt%, Mn: <0.45 wt%, Cu, Ni, Zn, Pb, Sn, and Ti) (EOS 2014) (Prototypes & Manufacturing Services, 2014), with particle sizes <25 µm according to the supplier data sheet. Three types of powder were used and defined as follows.P0 corresponds to the AlSi10Mg powder before additive manufacturing (virgin powder).P1 corresponds to the AlSi10Mg powder after one manufacturing cycle and sieving at <53 µm (vibratory sieve, RETSCH sieve shaker as 200).P2 corresponds to the AlSi10Mg powder after a second manufacturing cycle without sieving.