ZnO thin film-nanowire array homo-structures with tunable photoluminescence and optical band gap

The growth and optical behavior of ZnO thin film-nanowire array homo-structures is reported. The ZnO films are deposited on glass substrates by thermal evaporation and subjected to heat treatment at 400 °C for 2 h to achieve crystallinity and stoichiometry. The surface comprises spherical grains or elongated flakes depending on thickness of films. These films are introduced in to a hydrothermal reactor in a medium of zinc acetate and HMTA to realize the nanostructures. The process results in the formation of ZnO nanowires with dimensions that are strongly dependent on the surface microstructure of the ZnO films. The role of temperature (90–180 °C) and duration (10 min to 10 h) of hydrothermal processing is investigated in detail. It is demonstrated that low temperature and short duration are ideal for producing nanowires with diameter < 100 nm, while longer durations and higher temperatures lead to large diameter and long length nanowires. Interestingly, all wires converge to a hexagonal shape with increase in duration or temperature. The lowest diameter of the vertically aligned nanowires is 50 nm and length upto 10 μm is achieved. Optical band gap of the homo-structures is of the order of 3.4–3.5 eV. Raman and photoluminescence spectra indicate the presence of defects in the films. The thin films exhibit a strong defect related photoluminescence peak centred around 550 nm. The nanowires grown on the films display both the UV-near band edge peak as well as the defect related peak. However, the intensity of the defect peak decreases with increase in length of the nanowires indicating that the photoluminescence of the homo-structures can be tuned by changing the surface microstructure of the films and also the aspect ratio of the nanowires.

ZnO homo-structures with tunable photoluminescence and band gap.     

Ganglion cyst arising from the transverse acetabular ligament (TAL): a rare cause of entrapment of the anterior branch of the obturator nerve. Case report and review of the literature

Skeletal Radiology - The transverse acetabular ligament is an unusual location for ganglion cysts. Only a few cases have been reported in the literature. They can be asymptomatic and represent an...     

Accumulation of Cadmium in Transplanted Lichen Pyxine cocoes (Sw.) Nyl., with Reference to Physiochemical Variation and Kinetics of Cadmium Biosorption

Bulletin of Environmental Contamination and Toxicology - The safe utilization and risk assessment of produced water (PW) from oil and gas fields for desert irrigation have received increasing...     

Research letters

Patients with transfusion-dependent thalassemia are expected to have an unfavorable quality of life due to multiple factors. We studied the quality of life in 72 patients (age 5-39 y) with transfusion-dependent thalassemia in the era of improved care, and assessed different parameters affecting it.     

One stage slide cricotracheoplasty and repair of complete atrioventricular septal defect

Successful single stage repair of complete atrioventricular septal defect and cricotracheal stenosis in an 8-month-old baby with Trisomy 21 is described. The case is notable for rarity of cricoid stenosis being managed together with the long segment tracheal narrowing using the technique of slide cricotracheoplasty.     

Uncontrolled haemorrhage in pelvic fracturesdCan the inevitable be avoided?

Pelvic fractures carry a considerable risk for morbidity and mortality. Half or more of the early deaths in these patients have been attributed directly to haemorrhage. The transfusional requirements are four times higher for open pelvic fractures compared with a similar group of closed pelvic fractures. The loss of the tamponade effect by disruption of the pelvic soft tissues and the energy imparted play a central role in this potentially life threatening situation. We reported a case of open pelvic fracture in which persistent haemorrhage was stopped by giving recombinant activated coagulation factor VIIa as our last resort.