Prospective study comparing early functional outcome and gait analysis in femoral neck fracture treated by cemented hemiarthroplasty using modified Hardinge approach and conventional posterior approach

Background: A prospective study was done to compare the outcomes of management of fracture neck of femur by cemented hemiarthroplasty using modified Hardinge approach and conventional posterior approachMethods: The 2019 to 2022 50 patients underwent bipolar hemiarthroplasty for femoral neck fracture. Group A (Femoral neck fracture treated using conventional posterior approach) and group B (Femoral neck fracture treated using modified Hardinge approach) with 25 patients in each group. Outcomes were evaluated based on mean surgical time and Harris hip score and SF-36.Results: Mean duration of surgery in minutes was more for modified Hardinge approach. Harris hip score with standard deviation for modified Hardinge Approach for follow-ups was better and statistically significant than posterior approach. Similarly, quality of life after surgery, in terms of mean SF-36 score with standard deviation for modified Hardinge approach was better and statistically significant than posterior approach. Modified Hardinge approach has fewer complications in comparison to the posterior approach. With the advantages comes a longer learning curve to operate without complications. Hence, with proper surgical technique, and proper tight closure, we prefer the modified Hardinge approach over other approaches as it had nil dislocations and abductor lurch.Conclusions: Modified Hardinge approach for hip arthroplasty in elderly people with femoral neck fracture provide significant benefit in the early post operative period when compared to conventional posterior approach in terms of post operative pain, time of recovery, dislocation rate and quality of life

Minimization of material inter-diffusion for thermally stable quaternary-capped InAs quantum dot via strain modification

In this study, a theoretical model is developed for investigating the effect of thermal annealing on a single-layer quaternary-capped (In0.21Al0.21Ga0.58As) InAs quantum dot heterostructure (sample A) and compared to a conventional GaAs-capped sample (sample B). Strain, an interfacial property, aids in dot formation; however, it hinders interdiffusion (up to 650 degrees C), rendering thermal stability to heterostructures. Three diffusing species In! Al/Ga intermix because of the concentration gradient and temperature variation, which is modeled by Fick's law of diffusion. Ground-state energy for both carriers (electron and holes) is calculated by the Schrodinger equation at different annealing temperatures, incorporating strain computed by the concentration-dependent model. Change in activation energy due to strain decreases particle movement, thereby resulting in thermally stable structures at low annealing temperatures. At low temperature, the conduction band near the dot edge slightly decreases, attributed to the comparatively high strain. Calculated results are consistent with the experimental blue-shift i.e. towards lower wavelength of photoluminescence peak on the same sample with increasing annealing temperatures. Cross-sectional transmission microscopy (TEM) images substantiate the existence of dot till 800 degrees C for sample (A). With increasing annealing temperature, interdiffusion and dot sublimation are observed in XTEM images of samples A and B. Strain calculated from high resolution X-ray diffraction (HRXRD) peaks and its decline with increasing temperature are in agreement with that calculated by the model. For highlighting the benefits of quaternary capping, InAlGaAs capping is theoretically and experimentally compared to GaAs capping. Concentration-dependent strain energy is calculated at every point and is further used for computing material interdiffusion, band profiles, and photoluminescence peak wavelength, which can provide better insights into strain energy behavior with temperature and help in the better understanding of thermal annealing. (C) 2017 Elsevier Ltd. All rights reserved

Effects of phosphorus implantation time on the optical, structural, and elemental properties of ZnO thin films and its correlation with the 3.31-eV peak

To study the effects of implantation on ZnO thin films grown on Si substrates, we have subjected it to phosphorous ion implantation for 10, 40, and 70 s through plasma immersion ion implantation and rapid thermal annealing. Low-temperature photoluminescence spectra of the as-implanted samples exhibited a reduction in the donor-bound exciton peak at 3.36 eV with implantation time. The photoluminescence spectrum of the 70 s implanted 1000 degrees C-annealed sample confirmed acceptor-type doping. X-ray diffraction measurements showed a reduction in the c-axis length along the direction with implantation time, evidencing phosphorous-ion incorporation in the implanted films, which was further confirmed by the blue shifting of the E2 high peak in the Raman spectra. XPS measurements affirmed the presence of the P 2p peak, a signature of P-O bond, and confirmed the substitution of Zn atoms by P atoms and the subsequent formation of the Pzn-2Vzn complex essential for acceptor-type conductivity. (C) 2018 Elsevier B.V. All rights reserved

Deformation of Stacked Metallic Sheets by Shock Wave Loading

The focus of the present work is to develop a deep understanding of deformation of stacked metal sheets with a series of different sequences by using shock wave loading. Here, experimental and numerical investigations of deformation of a single metal sheet of 1.5-mm and the stack of three metal sheets of 0.5-mm thickness of aluminum (Al), copper (Cu) and brass (Br) material were carried out. In the shock wave experiments, helium was used as the driving gas to produce a strong shock wave. Finite elements method (FEM) simulations on 3D-computational models were performed with explicit dynamic analysis, and Johnson-Cook material model was used. The obtained results from experiments of the outer diameter, thickness distribution, and dome height were analyzed and compared with the numerical simulations, and both the results are in excellent agreement. Moreover, for the same pressure load, due to lower inter-metallic friction in the stacked sheets compared to a cohesive property of the single sheet, an excellent deformation of stacked metallic sheets was observed. The results of this work indicated that the shock wave-forming process is a feasible technique for mass production of stacked metallic sheets as well as fabricating a hierarchical composite structure, which provides higher formability and smooth thickness distribution compared to a single material

Role of Pzn-2Vzn centre on the luminescence properties of phosphorus doped ZnO thin films by varying doping concentration

Zinc oxide (ZnO) thin films were deposited using RF sputtering followed by plasma immersion ion implantation for 10-70 s to dope phosphorus on ZnO. Optical and structural characteristics from particular experiments (Photoluminescence (PL)), High resolution X-ray diffraction (HRXRD) and energy dispersive x-ray spectroscopy (EDX) confirms presence of phosphorus doping in implanted ZnO thin films. Dominant peak at around 3.35 eV measured from low temperature PL (18 K) measurement which assign as neutral acceptor-bound exciton peak. Two peaks: free electron acceptor and donor bound acceptor were observed at around 3.32 and 3.25 eV. The acceptor level was observed at 107 meV above the valence band. All samples exhibited dominant (002) crystal orientation peak in HRXRD measurements, indicating perfect c-axis orientation. Highest carrier (hole) concentration of 9.94 x 10(17) cm(-3) was measured from 60 s implanted sample. Formation of complex acceptor P(Zn-)2V(Zn) was justified by EDX measurements

Enhancement in optical characteristics of c-axis-oriented radio frequency-sputtered ZnO thin films through growth ambient and annealing temperature optimization

High-quality radio frequency sputtered ZnO were grown on Si substrates at 400 degrees C at various partial gas pressures (Ar/Ar + O2). Subsequently, to remove as-grown defects, high temperature annealing from 700 to 900 degrees C on as-grown samples in constant oxygen flow for 10 s was performed. X-ray diffraction study confirmed the formation of highly crystalline films with a dominant peak at (002). The sample grown in 50% Ar and 50% O-2 ambient exhibited the lowest linewidth (2 theta = similar to 0.2728 degrees) and highest stoichiometry. Grain size of the as grown samples decreased with increase in the partial pressure of oxygen till a certain ratio (1:1), and photoluminescence (PL) improved with increase in annealing temperature. Low-temperature (18 K) PL measurements showed a near-band-edge emission peak at 3.37 eV, and the highest peak intensity (more than six orders compared to others with narrow linewidth of similar to 0.01272 eV) was exhibited by the sample annealed at 900 degrees C and was six orders higher than that of the as-grown sample. All as-grown samples exhibited dominant visible-range peaks due to emission from defect states

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AuGe surface plasmon enhances photoluminescence of the InAs/GaAs bilayer quantum dot heterostructure

We report an improvement in the photoluminescence of a GaAs-capped InAs/GaAs bilayer quantum dot (QD) heterostructure by AuGe nanoparticle deposition on the surface of a thin capped layer. Scanning electron microscopy confirmed the formation of AuGe nanoparticles on the surface at temperatures ranging from 300 to 700 degrees C. Optical absorption spectroscopy revealed the plasmon resonance peak of AuGe nanoparticles at around 670 nm for the sample annealed at 300 degrees C, confirming the presence of the plasmonic effect. Raman spectroscopy revealed a QD phonon peak at similar to 238.5 cm(-1) for the sample annealed at 300 degrees C, indicating InAs QDs in the heterostructure. Compared to the uncovered sample, enhancements were observed in the PL spectra of the AuGe-deposited samples annealed at 300 degrees C and 400 degrees C (with enhancement factors of 2.58 and 2.18, respectively). The observed enhancement is attributed to photon trapping by scattering from the cross section of the dipole radiation field. Increasing the annealing temperature from 300 degrees C to 700 degrees C blue-shifted the photoluminescence peaks at 18 K because of In/Ga inter-diffusion. A decrease in activation energy was observed with the increase in annealing temperature from 300 degrees C to 700 degrees C, attributed to poor confinement potential and high electron concentration at the sample surface. Our findings contribute to the realization of high-efficiency plasmonic-based InAs QD detectors for optical communication in the 1300 nm optical window

Emerging material zinc magnesium oxide based nanorods: Growth process optimization and sensor application detection

In this paper, we provide a detailed investigation on the optical and physical properties of self-assembled Zinc magnesium oxide (Zn0.85Mg0.15O) based nanostructures which is an emerging material for optoelectronic devices. An enhancement was observed in the optical and material properties of vertically aligned highly crystalline Zn0.85Mgx0.15O nanorods grown using site nucleated hydrothermal treatment. Various parameters such as, the molar ratio of zinc nitrate hexahydrate, hexamethylenetetramine and growth time were optimized to achieve high-density of the nanorods. Photoluminescence (PL) measurement at 18 K revealed a peak at 3.61 eV corresponding to excitonic near-band-edge (NBE) emission from 'As annealed' sample and a peak with low intensity at 3.37 eV confirming the presence of another phase (ZnO) in grown nanorods. X-Ray diffraction (XRD) spectra of Zn0.85Mg0.15O samples showed highly c-axis- oriented growth with dominant peak making them ideal for gas/humidity sensing applications. Room temperature PL spectrum exhibited reduction in defect states peak with increasing relative humidity levels. DC Current-Voltage characteristics showed increase in current intensity after exposing the sample to controlled relative humidity (RH). The proposed Zn1-xMgxO based sensor exhibited high sensitivity 1.503%/ RH for change in RH and response time similar to 7-8 min. (C) 2017 Elsevier B.V. All rights reserved