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Your search keyword '"Samir de Moraes Shubeita"' showing total 2 results
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2 results on '"Samir de Moraes Shubeita"'

1. Resurgence of a Nation’s Radiation Science Driven by Its Nuclear Industry Needs

Author

Laura Leay, Aliaksandr Baidak, Christopher Anderson, Choen May Chan, Aaron Daubney, Thomas Donoclift, Gemma Draper, Ruth Edge, Jeff Hobbs, Luke Jones, Nicholas J. S. Mason, Darryl Messer, Mel O’Leary, Robin Orr, Simon M. Pimblott, Samir de Moraes Shubeita, Andrew D. Smith, Helen Steele, Paul Wady, and Frederick Currell

Subjects
radiolysis, nuclear science, radiotherapy, ionizing radiation, radiation chemistry in nuclear technology, sources of ionizing radiation, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999
Abstract

This article describes the radiation facilities and associated sample preparation, management, and analysis equipment currently in place at the Dalton Cumbrian Facility, a facility which opened in 2011 to support the UK’s nuclear industry. Examples of measurements performed using these facilities are presented to illustrate their versatility and the breadth of research they make possible. Results are presented from research which furthers our understanding of radiation damage to polymeric materials, radiolytic yield of gaseous products in situations relevant to nuclear materials, radiation chemistry in light water reactor cooling systems, material chemistry relevant to immobilization of nuclear waste, and radiation-induced corrosion of fuel cladding elements. Applications of radiation chemistry relevant to health care are also described. Research concerning the mechanisms of radioprotection by dietary carotenoids is reported. An ongoing open-labware project to develop a suite of modular sample handling components suited to radiation research is described, as is the development of a new neutron source able to provide directional beams of neutrons.

Published
2021
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2. Two Birds with One Stone: Concurrent Ligand Removal and Carbon Encapsulation Decipher Thickness-Dependent Catalytic Activity

Author

Kun Guo, Litao Chang, Ning Li, Lipiao Bao, Samir de Moraes Shubeita, Aliaksandr Baidak, Zhixin Yu, and Xing Lu

Subjects
Mechanical Engineering, General Materials Science, Bioengineering, Matematikk og Naturvitenskap: 400 [VDP], General Chemistry, Condensed Matter Physics
Abstract

A carbon shell encapsulating a transition metal-based core has emerged as an intriguing type of catalyst structure, but the effect of the shell thickness on the catalytic properties of the buried components is not well known. Here, we present a proof-of-concept study to reveal the thickness effect by carbonizing the isotropic and homogeneous oleylamine (OAm) ligands that cover colloidal MoS2. A thermal treatment turns OAm into a uniform carbon shell, while the size of MoS2 monolayers remains identical. When evaluated toward an acidic hydrogen evolution reaction, the calcined MoS2 catalysts deliver a volcano-type activity trend that depends on the calcination temperature. Rutherford backscattering spectrometry and depth-profiling X-ray photoelectron spectroscopy consistently provide an accurate quantification of the carbon shell thickness. The same variation pattern of catalytic activity and carbon shell thickness, aided by kinetic studies, is then persuasively justified by the respective limitations of electron and proton conductivities on the two branches of the volcano curve.

Published
2022

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