Informatics Publishing Limited

J. Srinivasan ¹

Affiliations
1 Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bangalore 560 012, IN

Abstract

The higher monsoon precipitation documented in the Northern Hemisphere during the Mid-Holocene has been examined by many investigators using General Circulation Models (GCM).Most investigators rely on the land-sea contrast theory to explain the higher precipitation during the Mid-Holocene. The basic flaw in the land-sea contrast theory is highlighted. An alternative theory based on energy and mass conservation is discussed. The alternative theory shows how the precipitation could have increased in the Mid-Holocene directly through the increase in insolation and indirectly through increase in the integrated water vapor in the atmosphere.

Keywords

Monsoon, Paleoclimate, Climate models.

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M. Shravanth Vasisht ¹, C. Vishal ¹, J. Srinivasan ¹, Sheela K. Ramasesha ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bangalore 560 012, IN

Abstract

Awareness for the need of sustainable and ecofriendly mobility has been increasing and various innovations are taking place in this regard. A study was carried out to assess the feasibility of installing solar photovoltaic (PV) modules atop train coaches. Most long-distance trains having LHB coaches do not have self-generating systems, thus making power cars mandatory to supply the required power for lighting loads. Feasibility of supplementing diesel generator sets with power from solar PV modules installed on coach rooftops has been reported in this communication. Not only is there a conservation of fuel, there is also a significant reduction in CO₂ emissions. This work has shown that the area available on coach rooftops is more than sufficient to generate the required power, during sunlight hours, for the electrical loads of a non-A/C coach even during winter. All calculations were done keeping a standard route as the reference. Taking the cost of diesel to be Rs 66/litre, it was estimated that there will be annual savings of Rs 5,900,000 corresponding to 90,800 litres diesel per rake per year by implementing this scheme. The installation cost of solar modules would be recovered within 2-3 years. Implementation of this scheme would also amount to an annual reduction of 239 tonnes of CO₂ emissions.

Keywords

Carbon Dioxide Emissions, Diesel, Rail Coaches, Solar Modules.

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J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bangalore 560 012, IN

Abstract

No Abstract.

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Roshan R. Rao ¹, H. R. Swetha ¹, J. Srinivasan ¹, Sheela K. Ramasesha ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

Tracking systems, that continually orient photovoltaic (PV) panels towards the Sun, are expected to increase the power output from the PV panels. Tremendous amount of research is being done and funds are being spent in order to increase the efficiency of PV cells to generate more power. We report the performance of two almost identical PV systems; one at a fixed latitude tilt and the other on a two-axis tracker. We observed that the fixed axis PV panels generated 336.3 kWh, and the dual-axis Sun-tracked PV panels generated 407.2 kWh during August 2012-March 2013. The tracked panels generated 21.2% more electricity than the optimum tilt angle fixed-axis panels. The cost payback calculations indicate that the additional cost of the tracker can be recovered in 450 days.

Keywords

Cost Payback Time, Dual Axis Sun Tracker, Energy Conversion, Solar Panel.

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G. Bala ¹, J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

No Abstract.

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U. S. Maanya ¹, Anil V. Kulkarni ¹, Alok Tiwari ¹, Enakshi Dasgupta Bhar ¹, J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

The Himalayan glaciers feed major Asian river systems sustaining the lives of more than 800 million people. Though the rates of retreat of individual glaciers are uncertain, on the whole the Himalayan glaciers have been losing mass at an increasing rate over the past few decades. With the changing climate, glaciers will continue to shrink and the rates of retreat may increase even further. This may lead to the formation of moraine dammed glacial lakes, which can cause outburst floods upon failure of the dam, catastrophic to human life and infrastructure downstream. Therefore, identification of potential lake sites and predicting the expansion of existing lakes are crucial for timely monitoring and mitigation of these hazards. In the present study, glacier surface velocity and slope are used to calculate ice thickness, by applying a basic parallel flow model, subsequently outlining the bed topography and locating potential lake sites in overdeepenings in the bedrock. Comparison of the modelled and measured ice thickness values on Chhota Shigri glacier suggests a model uncertainty of ±15%. The model is further applied to Samudra Tapu and Drang Drung glaciers using satellite data between the years 1999 and 2001, where eight potential lake sites were identified with mean depths varying between 33 ± 5 and 93 ± 14 m, of which three sites have a volume greater than 0.01 km³. The analysis predicts an over-deepening near the snout of Samudra Tapu, in close proximity to an existing moraine dammed lake. A portion of the predicted site has already evolved into a lake between the years 2000 and 2015, which upon further deglaciation could lead to an expansion of the existing lake by an area of 14 ± 2 ha. This observation further validates the model prediction of lake expansion. The present study demonstrates the utility of the model to predict maximum expansion of the existing lakes and possible formation of new lakes due to glacier retreat. Systematic application of this technique can provide information crucial to policy makers and planners dealing with the security of people living in the mountains.

Keywords

Bed Topography, Glacial Lakes, Ice Thickness, Remote Sensing.

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J. Srinivasan ¹, S. Audithan ²

Affiliations
1 Department of Computer Science and Engineering, St. Peter’s University, Chennai - 600054, Tamil Nadu, IN
2 Department of Computer Science and Engineering, PRIST University, Kumbakonam - 612501, Tamil Nadu, IN

Abstract

Objectives: This paper presents Secure Authentication Framework Design and Routing Metric based Communication in Multi-hop WMNs (SAF&RM). Methods/Statistical Analysis: In this paper, we use the PKC based pseudonyms that builds secure authentication framework with conditional privacy and Probabilistic Transmission Count (PTC) routing metric for improving reliable communications in WMN. Findings: The combination of MAC-layer retransmission-based reliability and link quality awareness effects are captured for designing the PTC. Applications/Improvements: This approach aims to diminish the sum of overall forwarding nodes in the routing and reduce the bandwidth consumption of the network which ensure high end-to-end packet delivery rate and improve the secure transmission in WMN.

Keywords

Pseudonyms, Probabilistic Transmission Count, Security, Trust Authority, Wireless Mesh Networks.

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H. Mitavachan ¹, J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru-560 012, IN

Abstract

About 70% of total electricity generation in India in 2015-16 came from thermal power plants that burn coal. Further, coal power plants still dominate the planned power capacity additions under the 12th and 13th five-year plans. The coal-based thermal power plants are considered to be least expensive and more reliable in the present electricity grid infrastructure. Here, we present a holistic overview of coal and solar photovoltaic (PV) power generation options. The former is dominant in today's power grid and the latter is expected to play a major role in future low-carbon grid. These power supply options are evaluated with respect to a set of seven sustainability criteria. This study examines the two power generation options based on technoeconomic and environmental indicators.

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Dipendra Singh , V. Suresh Babu , J. Srinivasan

Abstract

In this paper modeling of rotating seal and friction damper is explained using NX7.5 and ANSYS130x64 software. Modeling of any component is very important in analysis of the component. Analysis of rotating seal and damper is carried out using ANSYS130x64 to calculate stiffness of friction damper. Various authors explained methods to calculate stiffness of friction damper. In this paper a method is proposed to calculate stiffness of friction damper.

Keywords

Friction Damper, Rotating Seal, Damper Stiffness and Damper Circumferential Growth.

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M. Rajeevan ¹, J. Srinivasan ²

Affiliations
1 Ministry of Earth Sciences, Government of India, Prithiv Bhavan, New Delhi 110 003, IN
2 Centre for Atmospheric and Oceanic Sciences, Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

Prof. Tiruvalam Natarajan Krishnamurti, a renowned tropical meteorologist, passed away in Florida, USA on 7 February 2018. In his academic career spanning 67 years, Krishnamurti played a key role in the transformation of tropical meteorology from a descriptive subject to one that used sophisticated numerical as well as observational techniques and powerful computers to make accurate predictions of tropical weather and climate. He was the Raman Chair Professor of the Indian Academy of Sciences, Bengaluru during December 1998-December 1999.

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J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru - 560 012, IN

Abstract

No Abstract.

Keywords

No Keywords.

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Arindam Chakraborty ¹, J. Srinivasan ²

Affiliations
1 Centre for Atmospheric and Oceanic Sciences, and Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, IN
2 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

Will the onset of the Indian summer monsoon change due to increased concentration of anthropogenic aerosols? What should be an ideal definition of the onset of monsoon? How will the onset of the Indian monsoon change in the future? These were some of the key questions that were discussed in a workshop held recently.

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Anasuya Gangopadhyay ¹, Radhika Kanase ², Greeshma Mohan ², Madhuparna Halder ², Medha Deshpande ², Parthasharathi Mukhopadhyay ², J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, IN
2 Indian Institute of Tropical Meteorology, Dr Homi Bhabha Road, Pune 411 008, IN

Abstract

The wind speed forecast by a weather forecast model (with a resolution of 3 km) has been used to identify regions with high wind speed in Karnataka. The correlation between daily wind speed predicted by the model and the measured wind speed at three stations in Karnataka has been shown to be high. Based on this model, new locations have been suggested for the installation of new wind power plants in Karnataka.

Keywords

Karnataka, Potential Site, Renewables, Weather Model, Wind Plant.

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J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

In 2015, Microsoft founder Bill Gates argued that the threat of a pandemic was more probable than a nuclear war. He wrote in the New England Journal of Medicine on 9 April 2015 that we must prepare for future epidemics of diseases that may spread more effectively than Ebola. He said ‘There is a significant chance that an epidemic of a substantially moreinfectious disease will occur sometime in the next 20 years’. In February 2015, the President of the United States of America Obama wanted a report on ‘Lessons learned from Ebola outbreak’. The report said ‘It is sobering to note the odds are increasing that the United States will be called upon again in the not too distant future to respond to another health crisis that threatens global security’.

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K. Krishna Moorthy , S. Suresh Babu , B. V. Krishna Murthy , J. Srinivasan

Abstract

No Abstract.

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Ashwin Seshadri ¹, J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

No Abstract.

Keywords

No Keywords.

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J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, India

Abstract

No Abstract.

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J. Srinivasan ¹

Affiliations
1 Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru 560 012, India, IN

Abstract

No Abstract.

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