This study showed differential risks associated with indoor air pollution from wood and coal burning, and provides novel evidence on cancer risks associated with solid fuel usage in India. Our findings suggest that reducing indoor air pollution from solid fuels may contribute to prevention of these cancers in India, in addition to tobacco and alcohol control programs.
The System of Rice Intensification (SRI) reportedly enhances the yields of rice (Oryza sativa L.) through synergy among several agronomic management practices. This study was conducted to investigate the effects on rice plant characteristics and yield by comparing the plants grown with different methods of cultivation – SRI vs. recommended management practices (RMP) focusing on the impact of different plant spacings.
Performance of individual hills was significantly improved with wider spacing compared with closer‐spaced hills in terms of root growth and xylem exudation rates, leaf number and leaf sizes, canopy angle, tiller and panicle number, panicle length and grain number per panicle, grain filling and 1000‐grain weight and straw weight, irrespective of whether SRI or RMP was employed. Both sets of practices gave their highest grain yield with the spacing of 20 × 20 cm; however, SRI yielded 40 % more than the recommended practice. At this spacing, canopies also had the highest leaf area index (LAI) and light interception during flowering stage. The lowest yield was recorded at 30 × 30 cm spacing under both the practices, as a result of less plant population (11 m−2), despite improved hill performance.
During the ripening stage, hills with wider spacing had larger root dry weight, produced greater xylem exudates, and transported these towards shoot at faster rates. These features contributed to the maintenance of higher chlorophyll levels, enhanced fluorescence and photosynthesis rates of leaves and supported more favourable yield attributes and grain yield in individual hills than in closely‐spaced plants.
Moreover, these parameters further improved in SRI, apart from the enhanced percentage of effective tillers and showed substantial and positive impacts on grain yield (17 %) compared with recommended practice. In conclusion, wide spacing beyond optimum plant density, however, does not give higher grain yield on an area basis and for achieving this, a combination of improved hills with optimum plant population must be worked out for SRI.
This experiment was done to assess the effect of different direct seeding methods and transplanting of rice (Oryza sativa L.), cv. Naveen on growth, grain yield and its yield components. The water-use efficiency of the production systems, comparative weed growth as well as labour requirements under each method was also studied. The different direct seeding methods of planting like dry seeding by broadcast (DSB), wet seeding by broadcast (WSB), wet seeding by broadcast followed by beushening (WSBB), wet seeding in line (WSL) and wet seeding in spots (WSS) were compared with the traditional transplanting (TPR) method. WSS gave significantly higher yield (11.8%) compared to TPR due to higher tillering, more panicle, and better grain filling. Weed population under DSB, WSB, and WSS were 5, 4, and 2 times more than that under TPR, respectively. Total water requirement for growing rice crop under transplanting, wet seeding and dry seeding methods of planting were 1041.2, 941.5 and 915.0 ha-mm, respectively. Water use efficiency (WUE) was lowest under dry seeding and highest under wet seeding in spots. WSL and WSS showed 9.7 and 24.0% higher WUE, respectively, than traditional TPR method. However, commonly adopted wet seeding method, i.e. wet seeding by broadcast (WSB) showed 10% less WUE than TPR. Wet seeding reduced 5 -20% labour requirements compared to TPR. In lines and spots seeding more labourers were required for the sowing, but weeding was found easier and less labour intensive in these methods. The labour requirement of wet-seeded and dry-seeded rice cultivation was also found less coinciding with the peak demand of labourers during the transplanting season. The results clearly indicate that wet seeding spot method of rice planting is an improved method that gives higher yield with less requirement of water and labour and easy weed management than the existing methods.
The paper investigates the problem of constrained reliability maximization by allocating redundancy and proposes how to solve it for a broad group of complex coherent systems. Redundancy is an effective engineering tool to enhance system reliability to make a system fail-safe. Since adding redundancy increases the cost and complexity of a system design, it should be used wisely. The work considers an exact solution to the problem under resource constraints and finds optimal redundancy numbers. The proposed method can accommodate any number of constraints. Numerical examples have been included. A sensitivity analysis has been carried out to show how sensitive the optimal allocation of redundant components and the gain in system reliability are to the budget allocation.
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