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This work highlights the influence of surface properties, on the characteristics of InAlN/GaN based high electron mobility transistor (HEMT) structures grown on the SiC substrate by metalorganic vapor phase epitaxy. The growth parameters, i.e., reactor pressure and V/III ratio were tuned to improve the morphological and two-dimensional electron gas (2DEG) characteristics of the HEMT structure. It was found that V/III ratio plays a significant role in improving surface morphology and 2DEG properties without altering average indium composition. It was also found that 2DEG properties are highly sensitive to surface morphology and its features. The step flow smooth surface morphology with very low surface and interface roughness was observed in optimized lattice-matched InAlN/GaN HEMT structures. The sheet resistance of ∼170 Ω/sq with good 2DEG concentration (∼2.4 × 1013 cm−2) and 2DEG mobility (∼1500 cm2/V s) was achieved in the optimized lattice-matched InAlN/GaN HEMT structure. A comparison between different barrier-based HEMT structures, i.e., lattice-matched InAlN/GaN and strained AlGaN/GaN, was also discussed. Their structural, electrical, morphological, and interfacial characteristics were compared. [ABSTRACT FROM AUTHOR]

A study was undertaken to assess the effect of β-carotene supplementation on fertility in lactating Kankrej cows. Advanced pregnant cows (n=18) were randomly assigned into three groups. Experimental animals in Group I were fed on basal diet, while in Group-II and III were supplemented with 500 and 1000 mg of β-carotene/animal/day, respectively, for a period of 42 days, 21 days each before and after calving. All the cows were subjected to per-rectal and ultrasonographic observations at the 7th, 15th, 21st and 30th day postpartum. The gross uterine involution occurred at 28.50±1.50, 25.50±2.01 and 24±1.89 days in Group I, II and III, respectively. The diameter of the cervix was found to differ non-significantly between the groups on the 7th, 15th and 30th day in Group III from Group I and II. There was a highly significant reduction in the mean diameter of the gravid and non-gravid horn on the 7th day in Group II and III as compared to Group I, and also on the 21st and 15th day, respectively, within Group I and II. First service conception rate and overall conception rate were observed to be higher in Group III followed by Group II and I. It was concluded that β-carotene supplementation peripartum @ 1000 mg/animal/day for a period of 42 days accelerates uterine involution and improves postpartum fertility in dairy animals. [ABSTRACT FROM AUTHOR]