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Mathematical and Computational Methods
Published in Parveen Berwal, Jagjit Singh Dhatterwal, Kuldeep Singh Kaswan, Shashi Kant, Computer Applications in Engineering and Management, 2022
Parveen Berwal, Jagjit Singh Dhatterwal, Kuldeep Singh Kaswan, Shashi Kant
where w (k, k′) represents the sum of the various electron scattering rates from a state with wave vector k to one with wave vector k′. We take into account the following scattering mechanisms for silicon. Electron- Acoustical phonon intravalley scattering for which the transition rate, in its elastic approximation, with as above equation acoustical intravalley scattering kernel coefficient and Dirac function, b Electron – phonon intervalley scattering, for which there are six contributions Where alpha runs over the three g1, g2, g3 and the three f1, f2, f3 intervalley scatterings, k alpha are the correspondent optical or acoustical intervalley scattering kernel co-efficient and the occupation number of phonons with frequency w alpha, KB and TL respectively being the Boltzmaan constant and the lattice temperature.
3+ on Phototherapy Lamp Phosphor Performance
Published in Vikas Dubey, Sudipta Som, Vijay Kumar, Luminescent Materials in Display and Biomedical Applications, 2020
Neha Dubey, Marta Michalska-Domańska, Jagjeet Kaur Saluja, Janita Saji, Vikas Dubey
The morphology and crystallographic structure of CaZrO3:Gd3+ samples were characterized by using SEM, TEM, XRD and Photoluminescence (PL) analysis. Particle morphology was investigated by FEGSEM (field emission gun scanning electron microscope) (JEOL JSM-6360). TEM measurements was executed by PHILIPS CM 200 Operating voltages: 20–200 kV Resolution: 2.4 Å. The XRD measurements were carried out using Bruker D8 Advance X-ray diffractometer. The X-rays were produced using a sealed tube and the wavelength of X-ray was 0.154 nm (Cu K-alpha). The X-rays were detected using a fast counting detector based on Silicon strip technology (Bruker LynxEye detector). The photoluminescence (PL) emission and excitation spectra were recorded at room temperature by use of a Shimadzu RF-5301 PC spectrofluorophotometer. As the excitation source was used a xenon lamp (Singh et al. 2016, Dubey and Tiwari 2016, Tiwari X., et al. 2016, Parganiha, et al. 2015, Tiwari and Dubey 2016, Dubey et al. 2015).
Introduction to Metallic Glasses
Published in Sumit Sharma, Metallic Glass–Based Nanocomposites, 2019
Generation of X-rays: Tungsten filament is heated in a vacuum to generate electrons. These electrons are accelerated toward a fixed target using a high potential field. They decelerate when they hit the target. The process of deceleration leads to the emission of energy in the form of X-rays. A broad, continuous distribution of X-rays called Bremsstrahlung are emitted. X-rays are also generated in one more way, which is discussed in the next few sentences. When electrons impinge a target material, electrons of the inner shells of the atoms (i.e., atoms of the target material) get ejected. Electrons from the outer shells “jump” into these gaps to attain stability. The energy difference between the electron of the inner shell and of the incoming electron is emitted in the form of X-rays. Several materials, viz., copper, chromium, iron, manganese, cobalt, nickel, and molybdenum can be used as target materials [4, 10]. The CuKα radiations are the X-rays obtained when copper is used as the target material [4]. K-alpha emission lines result when an electron falls to the innermost K shell from a 2p orbital of the second or L shell (n = 2 → n = 1, where n = principal quantum number). The path of X-rays in a typical XRD machine is shown in Figure 1.7a whereas a sample holder with a sample is shown in Figure 1.7b.
A nanoindentation study of the deformation mode for nanostructured ductile/brittle multilayers: cracking versus shear banding
Published in Philosophical Magazine Letters, 2019
L. Feng, Q. Zhou, Q. Jia, Y.D. Shi, Y. Wang, X. H. Zhao
A wide range of A/B (Ag/W, Cu/Ru and Cu/W) multilayer thin films with varying Λ (= hA+hB) and η (= hA/hB) were deposited on Si (111) at room temperature by magnetron sputtering, as listed in Table 1 (hA and hB donate the thickness of A and B layers, respectively). The film thickness ranged from 1 to 2 μm for different NMFs depending on the individual layer thicknesses [24,25]. The base pressure prior to sputtering was 6.3 × 10−5 Pa and the argon pressure during sputtering was 6.11 × 10−1 Pa. The residual stresses were all measured using a wafer stress analyzer (BGS 6341 IC). The stresses were in the range 200–500 MPa for the sputtered multilayers, values that are much smaller than the hardness (here 5–15 GPa) in the multilayers [24,25] and therefore have a limited impact on the results displayed in present work. X-ray diffraction (XRD) was carried out using an improved RigakuD/max-RB X-ray diffractometer with Cu K alpha radiation to determine the crystallographic texture of the films. The modulation and the interface structures of the as-deposited multilayers were examined using a JEOL 2100F high-resolution transmission electron microscopy (TEM) operated at 200 kV. After manual polishing, cross-section TEM samples were prepared with a Gatan Precision Ion Polishing System 691 using argon ions. The deformation mode under nanoindentation [26–28] was evaluated via a Berkovich indenter with a radius of 50 nm, under a continuous stiffness measurement mode with a fixed strain rate of 0.2 s−1 at room temperature. To make each multilayer comparable, the indentation depth was fixed as half of the film thickness. The morphologies of residual indentation were characterised using a versatile field scanning electron microscopy (SEM).
Electrochemical and characterisation study of corrosion of reinforcing steel embedded in kaolinite: two-year exposure study
Published in Corrosion Engineering, Science and Technology, 2021
Miloud Baghdad, Bachir Ait Saadi
XPS analyses were performed to identify the chemical composition of the corrosion product layer. The XPS analyses were acquired using a Thermo Scientific K-Alpha spectrometer with monochromatised Al k-α radiation (1486.6 eV). The spot diameter of the X-ray source on the samples was 200 μm and calibrated to C1s peak at 284.8 eV. The depth profile experiments were performed by sputtering the corrosion product layer with Ar+ ions. Spectra fitting were carried out by the Avantage software.