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Thermodynamics
Published in Harshad K. D. H. Bhadeshia, Theory of Transformations in Steels, 2021
There is only limited evidence in support of this conclusion. Whereas Mössbauer spectra indicate that at high pressures hcp iron is not ferromagnetic, it is unclear whether it is antiferromagnetic or paramagnetic [55, 56]. Iron-manganese alloys with fcc and hcp structures are known to be antiferromagnetic; the Néel temperature of a Fe-17Mnwt% hcp alloy is found to be about 240K [30, 56]. The study of the internal fields and the Néel temperatures of the Fe-Mn alloys in both the fcc and hcp structures indicate that the magnetic properties of the iron atoms in these two environments are similar. If these data are extrapolated to pure iron, then the internal field and Néel temperature of pure hcp iron can be estimated to be similar to that of pure γ-iron [56]. The Bethe-Slater curve which describes the relationship between the exchange coupling and interatomic distance implies that fcc and hcp iron should be antiferromagnetic [57].
Neutron Optics: Fundamentals
Published in Maria L. Calvo, Ramón Fernandez Álvarez-Estrada, Advances in Neutron Optics, 2019
Ramón F. Álvarez-Estrada, Maria L. Calvo
Certain selected elements provide further options for neutron detection through activation. For instance (in shorted notations for elements and reactions): iron (56Fe(n,p)56Mn), aluminum (27Al(n,α)24Na), silicon (28Si(n,p)28Al). Those elements are suitable because they have extremely large cross sections for the capture of neutrons within a very narrow energy band.
Mineral Resources, Pollution Control, and Nanotechnology
Published in Stephen L. Gillett, Nanotechnology and the Resource Fallacy, 2018
Such elements are intrinsically rare in the crust. The peak of nudeon binding energy lies in the vicinity of iron-56 (56Fe, Z = 26), so elements heavier than this cost energy to make, and this is reflected in these vasdy lower abundances of elements with Z > ∼ 28. Hence selective binding agents for these elements may merit attention. Because of its toxicity, selective complexing agents for lead have already been investigated.84
Corrosion resistance behaviour of concrete containing treated used foundry sand
Published in European Journal of Environmental and Civil Engineering, 2023
N. Gurumoorthy, K. Rajesh Kumar, M. Vinod Kumar, K. Hariharan Kannan
As mentioned earlier, in the uncracked specimen with water-cement ratio of 0.50, the lollipop-shaped specimens are subjected to impressed current for the estimated time period to experience weight loss of about 10%. To speed up the corrosion and shorten the test time, a voltage of 12 V constant (Al-Swaidani & Aliyan, 2015; Elmoaty Mohamed & Elmoaty, 2013; Pellegrini-Cervantes, 2013) was used. In the extant analysis, the accelerated corrosion technique was used to attain, within a certain time frame, the preferred theoretical degree of corrosion of steel and finally, to compare the relative corrosion enactment of various concretes with the chosen variables. The time required to accelerate corrosion was assessed by Faraday’s law, by calculating the region under the corrosion current vs. time curve, the loss of iron over time can be calculated. The corrosion current in addition to the weight loss of metal due to corrosion were used to estimate the theoretical mass loss percentage. where, t = duration of induced corrosion (seconds)A = atomic weight of iron (56 g)I = corrosion current (ampere)F = Faraday’s constant (96500 ampere seconds)
Seismic performance of earthquake-damaged corroded reinforced concrete beam-column joints retrofitted with basalt fiber-reinforced polymer sheets
Published in Structure and Infrastructure Engineering, 2022
Dejian Shen, Ming Li, Qun Yang, Chuyuan Wen, Ci Liu, Jiacheng Kang, Xuyang Cao
An adjustable constantly direct current with the maximum current intensity of 3 A was arranged for supplying the current and accelerating corrosion. The detailed time for the accelerating test was calculated on the basis of Faraday’s law by Eq. (1), which has been confirmed to be practical and reasonable in a manner (Kanchanadevi & Ramanjaneyulu, 2018; Li, Jin, Yan, Fu, & Xu, 2021): where is the logical mass loss, g; is the atomic weight of the iron (56 ); is the current intensity, A; is the duration of corrosion, s; is the ionic charge (); and is the Faraday’s constant (96,500 ).
Square-rebar corrosion-induced cover cracking and its time prediction for historical reinforced concrete buildings in China
Published in Journal of Asian Architecture and Building Engineering, 2022
Hui Jin, Qing Chun, Yiwei Hua, Shiqi Zhang
where is the total mass of steel lost to corrosion; is the atomic mass of iron (56 g); is the current (A); is the time (s); is the ionic charge; and is the Faraday’s constant (96, 500 A·s). According to the composition analysis of corrosion products for this type of square-rebars by Dong, Chun, and Xu et al. (2017), the value of the ionic charge is approximately 2, which is also the value used in this study. Therefore, the time can be obtained by: