North Eastern Regional Institute of Science and Technology

About: North Eastern Regional Institute of Science and Technology is a education organization based out in Itanagar, India. It is known for research contribution in the topics: Population & Raman spectroscopy. The organization has 813 authors who have published 1429 publications receiving 16122 citations.

Modulation index effect on inverter based induction motor drive

Abstract: Due to a substantial increase in the use of inverter for numerous electrical appliances starting from domestics to industrial drives, an inverter may be directly connected to the power grid system. The dependency on an inverter has been increased over the years. Hence, the proper and efficient design of the inverter will lead to higher efficiency. One of the major challenges is the generation of suitable gate pulses for power switching devices, which in turn depends on the modulation index. The selection of proper modulation index will help in the production of the rated voltage. If the modulation index is less, the duration of on-time pulses will be less and hence, the device's conduction time is also less, thereby the output voltage of the inverter is reduced. A reduced voltage, when applied to an induction motor will have lower speed and even its performance will be sluggish. The speed of the motor improves when it is operated in a closed-loop for the same modulation index. This research paper tries to bring out the effect of modulation index on speed control of an induction motor based on an inverter for both open as well as closed-loop operation. The simulated results indicate that the modulation index in the vicinity to unity will provide rated voltage for the smooth operation of the motor.

Secure energy aware multi-path routing with key management in wireless sensor network

Abstract: With the ability to work under critical environments where human interception is difficult, wireless sensor networks serves as a useful communication means for data transmission and collection. But like other wireless networks WSN is also prone to adversary interventions. So the researchers are addressing this issue to make routing protocols secure for communication. But due to the severe resource constraints on sensor nodes like limited battery life and limited storage capacity prevents the traditional complex security mechanisms to be employed on the sensor nodes. In this paper we propose a new routing algorithm called Secure Energy Aware Multipath Routing with Key Management (SEAM-KM) in Wireless Sensor Network. This protocol focuses on using a base station as the central control block for all kinds of computation like shortest path selection, routing table generation, Updating the routing table and distribution of pair wise keys among the sensor nodes and the base station. Leaving the energy consuming computations to be performed by the base station, the lifetime of the sensor nodes can be prolonged. Moreover distribution of pair wise keys among sensor nodes provides security among sensor nodes and also increases the resilience of the network. This protocol is resistive to some of the specific attacks which rely on forming attractive routes to lure the sensor nodes to communicate through the already compromised nodes.

Hydrological significance of Himalayan surface water and its management considering anthropogenic and climate change aspects

Abstract: Water plays a key role in maintaining different ecosystem services. The anthropogenic and climate change impacts studies on Himalayan water resources has been trending in recent years. The Indian Himalayan region cover several states like Jammu & Kashmir, Ladakh (Union territory), Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh and the hilly regions of Assam and West Bengal. Water resources in this region are the life support for humankind and rich biodiversity. Researchers has reported that the warming in the Himalayas is more than the global average, thereby climate change can affect significantly in the mountainous water resources so as the snow and glacial melt is the main lifeline of the perennial rivers’ flow. Almost every year, the heavy monsoon rainfall brings floods on the upstream highlands and then the downstream plains causing enormous human suffering, loss of property, loss of life, agricultural crops damage as well as increased economic losses. The main challenges being associated to the frequency and magnitude of extreme weather events like monsoon rainfall which leads to flash floods, landslides and debris flow; and then the drought during dry season also, has had huge impacts on regional water security. Human actions like economic development and population growth have also brought changes in land cover/use to Himalayan watersheds recently. As a result of farming, grazing, tree planting, urbanization, etc., the changes in land cover have altered the water balance and transformed the water-flow paths in the global hydrological cycle. In contrast to freshwater ecosystems, demand is high, but their supply is limited, also depend on the specific flow pattern of rivers. Although, with interference of various infrastructure development upstream results in changes in flow pattern downstream causing non-availability of water to support aquatic life and communities that depend on for livelihoods. Initiation of monitoring and observation system for water resources and use of appropriate hydrological model are preferable to better understand the hydrological processes of the Himalayas.

Investigation on keyhole mode fiber laser welding of SS 316 in a self-protected atmosphere:

Abstract: This work focuses on examining the influence of welding parameters under different welding atmospheres and evaluation of keyhole profile during fiber laser welding operation. The experiments are ca...