Mechanism of enhanced light output in InGaN-based microlight emitting diodes

Micro-light emitting diode (LED) arrays with diameters of 4 to 20 mum have been fabricated and were found to be much more efficient light emitters compared to their broad-area counterparts, with up to five times enhancement in optical power densities. The possible mechanisms responsible for the improvement in performance were investigated. Strain relaxation in the microstructures as measured by Raman spectroscopy was not observed, arguing against theories of an increase in internal quantum efficiency due to a reduction of the piezoelectric field put forward by other groups. Optical microscope images show intense light emission at the periphery of the devices, as a result of light scattering off the etched sidewalls. This increases the extraction efficiency relative to broad area devices and boosts the forward optical output. In addition, spectra of the forward emitted light reveal the presence of resonant cavity modes [whispering gallery (WG) modes in particular] which appear to play a role in enhancing the optical output

Vertebral arteries bilaterally passing through stellate (cervicothoracic) ganglion

Vertebral artery is a branch of the first part of subclavian artery. Vertebral artery arising from the aortic arch most commonly presents on the left side. The cervical part of sympathetic trunk is closely related to the vertebral artery in the cervical region. Though lots of variations regarding anomalous origin, course of vertebral artery is reported in the literature, here we present a rare anomaly in which vertebral artery after originating from aortic arch is passing through stellate ganglia and it enters into the transverse foramina of higher cervical vertebra (C5). Such variation should be kept in mind by anaesthetist during stellate ganglion block in order to relieve intractable pain in central nervous system lesion. Surgeons should keep this anomaly in mind during cervical spine surgery otherwise vertebral artery may get injured leading to haemorrhage

Analysis of Genetic Diversity among F4 segregating population of bitter gourd (Momordica charantia L.)

Seventeen breeding lines (ten F4 segregants and seven parents) of bitter gourd were evaluated at Department of Vegetable Science, OUAT, Bhubaneswar, during late kharif, 2022. These genotypes were used for evaluation of 13 quantitative characters which were grouped into five different clusters through Tocher’s method of genetic divergence analysis. Cluster I consists of ten genotypes, Cluster II, III and IV comprising of two genotypes each, while cluster V included only one genotype. Highest intra cluster distance was found in cluster IV (17.14) while lowest in cluster II (8.70). The highest inter cluster distance was observed between cluster III and V (26.18), followed by clusters I and V (25.06). For future breeding programme in bitter gourd, genotype of Cluster V should be selected for better vegetative growth, earliness in appearance of 1st female flower and giving yield for longer duration. Similarly, Cluster III for earliness in appearance of 1st male flower and more number of fruits vine-1 while that of cluster II should be considered for getting high yield with less number of seeds fruits-1. Seeds fruit-1 (61.03%) contributed maximum towards divergence followed by fruits vine-1 (12.50%)

Non-Supersymmetric Attractors in String Theory

We find examples of non-supersymmetric attractors in Type II string theory compactified on a Calabi Yau three-fold. For a non-supersymmetric attractor the fixed values to which the moduli are drawn at the horizon must minimise an effective potential. For Type IIA at large volume, we consider a configuration carrying D0, D2, D4 and D6 brane charge. When the D6 brane charge is zero, we find for some range of the other charges, that a non-supersymmetric attractor solution exists. When the D6 brane charge is non-zero, we find for some range of charges, a supersymmetry breaking extremum of the effective potential. Closer examination reveals though that it is not a minimum of the effective potential and hence the corresponding black hole solution is not an attractor. Away from large volume, we consider the specific case of the quintic in CP^4. Working in the mirror IIB description we find non-supersymmetric attractors near the Gepner point.Comment: Added a few clarification

Helioseismic Ring Analysis of CME Source Regions

We apply the ring diagram technique to source regions of halo coronal mass ejections (CMEs) to study changes in acoustic mode parameters before, during, and after the onset of CMEs. We find that CME regions associated with a low value of magnetic flux have line widths smaller than the quiet regions implying a longer life-time for the oscillation modes. We suggest that this criterion may be used to forecast the active regions which may trigger CMEs.Comment: Accepted for publication in J. Astrophys. Astr. Also available at http://www2.nso.edu/staff/sushant/paper.htm

Comparison of plain egg medium with Lowenstein- Jensen medium in the isolation of M. tuberculosis from sputum

The isolation of tubercle bacilli from sputum using a plain egg (PE) medium and the conventional Lowenstein-Jensen (L-J) medium has been investigated on 703 specimens. The isolation of positive cultures and the grades of positivity were similar with the two media. There was an indication that the growth on the PE medium was faster than on L-J medium. The incidence of contamination was similar and low (4.0 per cent on PE and 3.8 per cent on L-J medium). Being cheaper and simpler than L-J medium, the PE medium is ideally suited for the routine culturing of tubercle bacilli

Evaluation of ELISA as a diagnostic test in pulmonary tuberculosis

The reproducibility and ability of ELISA to discriminate patients with active disease from those infected were investigated.. The results obtained on 60 sputum-positive adult tuberculous patients and 60 adult control subjects showed groupwise discrimination. The anti-PPD antibodies (Ig G class) were significantly elevated in tuberculous patients as compared with control subjects. But because of the large day-to-day variation and considerable overlap in the distribution of antibody levels in tuberculous and control subjects, it is not possible to use ELISA as a diagnostic tool for adult pulmonary tuberculosis

Cell-mediated immunity in chyluria

Cellular immune response to mitogens phytohemaggluthin (PHA) and poke weed mitogen (PWM) was assessed in 13 patients with chyluria and 32 healthy controls. The mean stimulation Index of the patient group was significantly lower than the control group. The degree of depression was neither related to the duration of excretion of chyle nor to the microfilaraemic status