scholarly journals The use of DRS and GC to study the effects of ionizing radiation on paper artifacts

Nukleonika ◽  
2015 ◽  
Vol 60 (3) ◽  
pp. 665-668 ◽  
Author(s):  
Wojciech Głuszewski ◽  
Bartłomiej Boruc ◽  
Hieronim Kubera ◽  
Dinara Abbasowa

Abstract Radiation preservation of objects of historical significance is an interesting proposition for museums, archives, libraries and private collectors. In this paper, we have limited ourselves to studying the effects of ionizing radiation on the paper. The radiation resistance of various grades of paper was examined in INCT. Irradiations were done by electron beam (10 MeV, 10 kW) and by gamma radiation (7 kG/h), for the purpose of comparison. Yields of hydrogen and absorption of oxygen were determined by gas chromatography (GC). For this purpose, the first time in an original way was used diffuse reflection spectroscopy (DRS). Described as the dose, dose rate, and lignin were found to affect degradation processes of cellulose. Examined the protective effect of lignin in the process of radiation degradation of paper. Proposed research methodology can be successfully applied to study other materials relevant to the conservation of works of art.

2021 ◽  
Vol 12 (2) ◽  
pp. 117-123
Author(s):  
Zhenzhao Pei ◽  
Feng Li

In this study, it was discovered for the first time that the BiOBr/Bi3.84W0.16O6.24 catalyst can efficiently degrade sulfadiazine (SDZ). Multiple techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis diffuse reflection spectroscopy (DRS) were applied to research the structures, morphology and photocatalytic properties of as-prepared samples. In addition, the effect of different synthesis pH environment and initial SDZ solution pH on the catalyst degradation efficiency were discussed. The BiOBr/Bi3.84W0.16O6.24 catalyst synthesized under the condition of pH = 7 exhibited excellent photocatalytic activity for photodegradation of SDZ of 91% within 120 min under simulated solar light irradiation. Also, the roles of the radical species have been studied, and the ·O2- and h+ were proved to dominate the photocatalytic process. Based on the experimental results, the photocatalytic mechanism was proposed.


2015 ◽  
Vol 87 (17) ◽  
pp. 8740-8747 ◽  
Author(s):  
Stephanie A. DeJong ◽  
Zhenyu Lu ◽  
Brianna M. Cassidy ◽  
Wayne L. O’Brien ◽  
Stephen L. Morgan ◽  
...  

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 123 ◽  
Author(s):  
Andrea Bellmann ◽  
Christine Rautenberg ◽  
Ursula Bentrup ◽  
Angelika Brückner

UV–Vis spectroscopy as well as in situ FTIR spectroscopy of pyridine and CO adsorption were applied to determine the nature of Co species in microporous, mesoporous, and mixed oxide materials like Co–ZSM-5, Co/Na–ZSM-5, Co/Al–SBA-15, and Co/Al2O3–SiO2. Because all sample types show comparable UV–Vis spectra with a characteristic band triplet, the former described UV–Vis band deconvolution method for determination and quantification of individual cationic sites in the zeolite appears doubtful. This is also confirmed by results of pyridine and CO adsorption revealing that all Co–zeolite samples contain two types of Co2+ species located at exchange positions as well as in oxide-like clusters independent of the Co content, while in Co/Al–SBA-15 and Co/Al2O3–SiO2 only Co2+ species in oxide-like clusters occur. Consequently, the measured UV–Vis spectra represent not exclusively isolated Co2+ species, and the characteristic triplet band is not only related to γ-, β-, and α-type Co2+ sites in the zeolite but also to those dispersed on the surface of different oxide supports. The study demonstrates that for proper characterization of the formed Co species, the use of complementary methods is required.


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