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The present paper adopts a sophisticated numerical modeling technique using a plasticity-based simplified micro-model method and the extended finite element method for simulating the nonlinear behaviour of unreinforced masonry (URM) walls with different types of sizes and positions of openings. The validity of this model has been proven by comparing the results subjected to a similar loading obtained by the experimental approach. Thereafter, the validated computational model is used to study the behaviour of the 3D URM wall model with different opening percentages. The effect of the position of the openings is also studied. Further, the load–displacement curves are drawn to provide a clear idea about the load-carrying capacity of the same URM walls. The hysteretic behaviour obtained in each model under cyclic loading gives an idea about the energy dissipation capacity of each of the models studied. The same walls are analyzed by strengthening the walls with two cost-effective materials, wire mesh and polypropylene bands. Since the study on lateral behaviour of masonry walls, particularly regarding the effect of area and the position of the opening, is very rarely available, the present detailed study is believed to be helpful in reducing the seismic vulnerability of actual masonry structures, which always have openings with different sizes and positions. [ABSTRACT FROM AUTHOR]

Electronic and structural properties are studied at room temperature, whereas the magnetic performances of MoS2-nanoparticles (MoS2-NPs) are studied from room temperature (300 K) down to 5 K within the range of the magnetic field − 10 T to + 10 T. We find that MoS2-NPs display diamagnetic in the temperature range 300–50 K, whereas at ≈ 45 K the M–H hysteresis curve shows the presence of both diamagnetic and ferromagnetic behaviours. The existence of ferromagnetism is significantly enhanced from 40 K down to 5 K, presumably due to Mo-atom, S-vacancies/O-vacancies, defective structure due to the higher density of dangling bonds, and small MoS2-NPs sizes. Different ferromagnetic parameters viz. saturation magnetization, retentivity, and coercivity of MoS2-NP at ≈ 5 K are 55 m emu/g, 45 m emu/g, and 4500 Oe respectively are obtained from the M–H hysteresis curve. The electronic, microstructures and defects are also studied using XPS/UPS and Raman spectrum that correlated/consistence with the magnetic performances of MoS2-NPs. This low temperature (≤ 40 K) ferromagnetism in MoS2-NPs could be useful for low temperature promising potential technological magnetic applications. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) study show that the SnO2 and SnO2:F are Sn2+ dominated in the formation of SnO2 structure. The SnO2:F thin film is mainly the formation of metallic fluoride. The UPS study confirms the density of states of SnO2:F is higher than SnO2. The work function, valence band maximum and surface potentials of SnO2 (SnO2:F) are estimated from UPS spectra and are 3.9 eV (3.7 eV), 3.7 V (3.5 eV) and 7.6 eV (7.2 eV), respectively. Electrical conductivity and M–H hysteresis loop show SnO2:F have higher conductivity as well as magnetization. [ABSTRACT FROM AUTHOR]

A series of Eu3+-activated strontium silicate phosphors, Sr2SiO4:xEu3+ (SSO:xEu3+, x = 1.0, 2.0 and 5.0%), were synthesized by a sol–gel method, and their crystalline structures, photoluminescence (PL) behaviors, electronic/atomic structures and bandgap properties were studied. The correlation among these characteristics was further established. X-ray powder diffraction analysis revealed the formation of mixed orthorhombic α'-SSO and monoclinic β-SSO phases of the SSO:xEu3+ phosphors. When SSO:xEu3+ phosphors are excited under ultraviolet (UV) light (λ = 250 nm, ~ 4.96 eV), they emit yellow (~ 590 nm), orange (~ 613 nm) and red (~ 652 and 703 nm) PL bands. These PL emissions typically correspond to 4f–4f electronic transitions that involve the multiple excited 5D0 → 7FJ levels (J = 1, 2, 3 and 4) of Eu3+ activators in the host matrix. This mechanism of PL in the SSO:xEu3+ phosphors is strongly related to the local electronic/atomic structures of the Eu3+–O2− associations and the bandgap of the host lattice, as verified by Sr K-edge and Eu L3-edge X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure, O K-edge XANES and Kα X-ray emission spectroscopy. In the synthesis of SSO:xEu3+ phosphors, interstitial Eu2O3-like structures are observed in the host matrix that act as donors, providing electrons that are nonradiatively transferred from the Eu 5d and/or O 2p–Eu 4f/5d states (mostly the O 2p–Eu 5d states) to the 5D0 levels, facilitating the recombination of electrons that have transitioned from the 5D0 level to the 7FJ level in the bandgap. This mechanism is primarily responsible for the enhancement of PL emissions in the SSO:xEu3+ phosphors. This PL-related behavior indicates that SSO:xEu3+ phosphors are good light-conversion phosphor candidates for use in near-UV chips and can be very effective in UV-based light-emitting diodes. [ABSTRACT FROM AUTHOR]

Background: Pneumocephalus is a common complication presented as air in the cranial cavity after cranial surgery. We present a very rare case of isolated new onset aphasia due to pneumocephalus after evacuation of subdural hematoma (SDH). Tension pneumocephalus presenting as isolated aphasia has not been reported earlier although associated paresis has been reported. Case presentation: We present the case of a 13-year-old male child with a history of fall before the onset of symptoms like headache and vomiting. The immediate MRI of the brain showed left-sided frontotemporoparietal subacute SDH with significant midline shift and subfalcine herniation. The child was subsequently managed with craniotomy and evacuation of hematoma with duraplasty. The patient developed aphasia on second-day post-surgery which progressed from moderate to severe aphasia by day 4. Computed tomography (CT) scan revealed pneumocephalus and an increase in the pneumocephalus in imaging on post-op day 4 with no other abnormalities. The condition was then managed by removing the subgaleal drain and administering high flow oxygen of 10 l/min. Conclusion: This case signifies the importance of proper diagnosis of new-onset neurological deficits after evacuation of subdural hematoma for the better outcome. [ABSTRACT FROM AUTHOR]