System-Level Performance Analysis in 3D Drone Mobile Networks

We present a system-level analysis for drone mobile networks on a finite three-dimensional (3D) space. A performance boundary derived by deterministic random (Brownian) motion model over Nakagami-m fading interfering channels is developed. This method allows us to circumvent the extremely complex reality model and obtain the upper and lower performance bounds of actual drone mobile networks. The validity and advantages of the proposed framework are confirmed via extensive Monte-Carlo (MC) simulations. The results reveal several important trends and design guidelines for the practical deployment of drone mobile networks

Integrated Prognostics Observer for Condition Monitoring of an Automated Manual Transmission Dry Clutch System

The closed loop feedback control system of an Automated Manual Transmission (AMT) electro-pneumatic clutch actuator is used for intelligent real time condition monitoring, enhanced diagnostics and prognostic health management of the dry clutch system, by integrating with the existing gearbox prognostics observer. The real-time sensor data of the clutch actuator piston position is analyzed for monitoring the condition of the clutch system. Original parameters of the new clutch are stored in the Electrically Erasable Programmable Read-only Memory (EEPROM) of the AMT controller and the real-time data is used by the observer for assessing the degradation/wear of the frictional clutch parts. Also, clutch slip during torque transmission is monitored, using the engine speed and the gearbox input shaft speed from Controller Area Network (CAN). Condition monitoring of clutch system provides enhanced prognostic functionality for AMT system which ensures consistent clutch performance, gear shift quality and timely warning for recalibration, repair and/or replacement of the critical wear and tear parts. Also, systematic analysis of the monitored data provides an accurate diagnosis of a developing fault. Thus, with the advanced control systems in place for AMT, a closed loop feedback based condition monitoring system is modelled for improved diagnostics and prognostics of AMT clutch system

Not Available

Not AvailableInsect pollinator abundance and diversity were assessed in sunflower (Helianthus annuus L.). Totally, 22 species of pollen and nectar foragers were recorded commencing from 0600 upto 1900 hrs at hourly intervals during different stages of flowering. The composition of different orders comprising of pollinator fauna were, Hymenoptera (72.73%), Diptera (9.09%) and Lepidoptera (18.18%). Among the Apis species (A. dorsata, A. cerana and A. florea), followed by non-Apis (T. iridipennis) were most abundant and they constituted 98 per cent of the total flower visitors in the variety Morden, the Shanon-Weiner index of diversity (H) computed for the pollinator fauna varied between 0.00 to 1.52 and 0.00 to 1.49 at 50 and 100 per cent flowering stage of the crop respectively. The Berger-Parker dominance index (‘d’) values ranged between 0.000 to 0.587 and 0.000 to 0.595, respectively, implying that A. dorsata was the most dominant species (0.587 & 0.595), followed by A. cerana (0.149 & 0.138) > A. florea (0.128 & 0.121) > T. iridipennis (0.091 & 0.095) at 50 and 100 per cent flowering stages, respectively.Not Availabl

Climate Change and Indian Agriculture: Challenges and Adaptation Strategies

Not AvailableClimate change reflects long term changes in temperature, relative humidity, rainfall and other climate variables. The factors causing climate change include both natural as well as human factors. Agriculture in India is predominantly monsoon dependent. However, the rise in temperature, uneven rainfall distribution and delayed onset of monsoon have led to drought or flood across different parts of the country. The horticulture crops are exceedingly prone to climate change owing to long economic life of the plant which requires huge initial investment and cultivating these crops has made farmers more vulnerable to climate change. There is a demand for climate smart horticultural practices or interventions which are customized to suit local needs. Strategies like conservation agriculture, natural resources conservation, reforestation, checks on population growth and pollution, reduction of greenhouse gas emissions, breeding drought resistant crops, tolerant to pests and diseases, early maturity, etc. are the need of the hour. Use of hi-tech horticulture practices will have to be implemented to meet the ever-changing dynamic challenges that emerged due to climate change. Identi cation of socio-economic factors that affect the adoption of the adaptation and mitigation strategies will help in formulating location specific strategies.Not Availabl

An assessment of the diversity in scenario-based tsunami forecasts for the Indian Ocean

This work examines the extent to which tsunami forecasts from different numerical forecast systems might be expected to differ under real-time conditions. This is done through comparing tsunami amplitudes from a number of existing tsunami scenario databases for eight different hypothetical tsunami events within the Indian Ocean. Forecasts of maximum tsunami amplitude are examined at 10 output points distributed throughout the Indian Ocean at a range of depths. The results show that there is considerable variability in the forecasts and on average, the standard deviation of the maximum amplitudes is approximately 62 of the mean value. It is also shown that a significant portion of this diversity can be attributed to the different lengths of the scenario time series. These results have implications for the interoperability of Regional Tsunami Service Providers in the Indian Ocean. © 2013 Elsevier Ltd

Fracture morphology of carbon fiber reinforced plastic composite laminates

Carbon fiber reinforced plastic (CFRP) composites have been extensively used in fabrication of primary structures for aerospace, automobile and other engineering applications. With continuous and widespread use of these composites in several advanced technology, the frequency of failures is likely to increase. Therefore, to establish the reasons for failures, the fracture modes should be understood thoroughly and unambiguously. In this paper, CFRP composite have been tested in tension, compression and flexural loadings; and microscopic study with the aid of Scanning Electron Microscope (SEM) has been performed on failed (fractured) composite surfaces to identify the principle features of failure. Efforts have been made in correlating the fracture surface characteristics to the failure mode. The micro-mechanics analysis of failure serves as a useful guide in selecting constituent materials and designing composites from the failure behavior point of view. Also, the local failure initiation results obtained here has been reliably extended to global failure prediction