Efficient land water management practice and cropping system for increasing water and crop productivity in semi‐arid tropics

In Indian semi-arid tropics (SATs), low water and crop productivity in Vertisols and associated soils are mainly due to poor land management and erratic and low rainfall occurrence. This study was conducted from 2014 to 2016 at the ICRISAT in India to test the effect of broad bed furrows (BBF) as land water management against conventional flatbed planting for improving soil water content (SWC) and water and crop productivity of three cropping systems: sorghum [Sorghum bicolor (L.) Moench]–chickpea (Cicer arientinum L.) and maize (Zea mays)–groundnut (Arachis hypogaea L.) as sequential and pearl millet [Pennisetum glaucum (L.)] + pigeonpea [Cajanus cajan (L.) Millsp.] as intercropping, grown under different nutrients management involving macronutrients (N, P, and K) only and combined application of macro- and micronutrients. The results stated that the SWC in BBF was higher over flatbed by 9.35–10.44% in 0- to 0.3-m, 4.56–9.30% in 0.3- to 0.6-m and 3.85–5.26% in 0.6- to 1.05-m soil depths during the cropping season. Moreover, depletion of the soil water through plant uptake was higher in BBF than in flatbed. Among the cropping systems, sorghum–chickpea was the best in bringing highest system equivalent yield and water productivity with the combined application of macro- and micronutrients. The BBF minimized water stress at critical crop growth stages leading to increase crop yield and water productivity in SATs. Thus, BBF along with the application of macro- and micronutrients could be an adaptation strategy to mitigate erratic rainfall due to climate change in SATs

Toxicity of the Sesquiterpene Lactone Parthenin to Cultured Bovine Kidney Cells

The cytotoxic effect of the sesquiterpene lactone, parthenin was studied IN VITRO using cultured bovine kidney cells. The drug inhibited macromolecular synthesis. Fifty percent inhibitions in RNA, DNA and protein synthesis were observed when the cells were treated with parthenin at a final concentration of 1 \mu g/ml. The cytotoxic effect of parthenin was also evident by its ability to markedly inhibit the activities of key cellular enzymes after treatment of the cells with the toxin for 24 h

Radioclimatology over Southern India

7-12Radioclimatology over southern India is studied and the results are discussed. The refractivity gradient is found to be maximum during premonsoon months in the coastal areas. Incidence of super-refraction is found to be maximum during April-May while it is minimum in the months of December and January. High refractivity gradients are found to be associated with temperature inversions or isothermals and with very high vapour pressure gradients

Microwave Propagation Characteristics over Hilly Terrain

83-87Microwave propagation characteristics over hilly terrain situated in southern India have been presented. Amplitude measurements at 7.6 GHz were made round the clock during Mar 1981-Apr 1983 using an operational communication link The daytime signal is characterized with fast and small amplitude fluctuations of the order of 2-3 dB while during night and early morning large amplitude variations sometimes as high as 20-25 dB are observed. High fade rates have been observed to be dominant during premonsoon months. The distribution of fade rates indicates that during monsoon and post-monsoon the fade rate is 30-40 (fades) per hour and the fade rate is 150 per hour in premonsoon while it is 90 per hour in winter

Control strategy for plug-in electric vehicles with a combination of battery and supercapacitors

Research proposes an optimal power distribution approach for application of electric vehicle (EV) with use of hybrid energy storage system (HESS). HESS protection structure includes dual isolated-based soft-switching symmetrical coupling with half-bridge bidirectional converters to the system of battery and supercapacitors (SCs). The bidirectional converter properly controls the charging process of the battery and SC as well. Besides, spiral wound SCs of mesoporous electrode material have been used in EVs. In the drive cycle of EVs, the operation of SC relates to the functionality of the allocated scheme under “peak load transfer” at 2i sc ∼ 3i bat current profile carried out. New energy allocation strategies under SOC control enable SC charging and discharging at peak currents of around 4i bat. The comparison of the mode of the battery system showed that the performance acceleration built under EVs has been improvised at a certain rate of 50% with a loss of energy minimised to 69%. As a result, the technique adapts different load curves, thus enhancing the utilisation of energy with reduced aging of the battery. The simulation results show that the proposed scheme meets the power demand of a typical driving cycle, for testing vehicle performance, and various energy management system have been assessed based on hydrogen consumption, overall efficiency, state of charge of SCs and batteries, stress on hybrid sources, and DC bus stability. The proposed strategy reduces hydrogen consumption by 8.7% compared to other strategies

Effect of Fresnel zone clearance on propagation characteristics of microwave links in hilly terrains

29-38The effect of Fresnel zone clearance on microwave propagation over a hilly terrain has been studied. The ray tracing technique for radio rays through the troposphere has also been discussed. The ray paths were traced for different elevation angles under varied meteorological conditions. Under subrefraction conditions, there was insufficient Fresnel zone clearance which leads to fade-outs of the received microwave signals. The antenna height at the transmitting end at Tiruttani was increased from 50 to 90 m to provide enough Fresnel zone clearance. A comparison of the performance of the microwave link before and after the modification of the antenna height has been presented. Propagation characteristics of Elagiri-Tirumala and Pallavaram-Tirumala microwave links situated over a hilly terrain are also presented. The field strength data have been analysed in terms of fade rate, average fade depth and scintillating index. The diurna

A qualitative study of wave motions in atmospheric boundary layer observed over Tirupati using sodar

134-140A study of wave motions in terms of diurnal variation, occurrence percentage, period, amplitude and height of waves in atmospheric boundary layer has been made using an acoustic sounder. The wave motions are usually associated with either surface-based inversions, elevated layers or rising inversions. Most of the time the observed waves have their periods ranging between 5 and 15 min and amplitudes between 100 and 150 m and usually occur in the height range 150-600 m. Power spectral densities of wave motions associated with different structures have also been computed