NOPR Collection:

Optimal Energy Calculation for Cooperative Grid Networks

Sun, 01 Nov 2015 00:00:00 GMT

Title: Optimal Energy Calculation for Cooperative Grid Networks Authors: Devi, B R; Rani, M A; Rao, K K Abstract: The Lifetime of Mobile Ad Hoc Network (MANET) depends on the battery capacity of nodes. IEEE 802.11 supports power saving mode (PSM) in which the station may be kept in awake mode or in a doze state. PSM is energy efficient, which improves the network lifetime and is suitable for MANETs. Node deployment in a network plays a vital role in its topology, routing and network lifetime. Node placement can be categorized into: Deterministic, Semi-deterministic and Non-deterministic types. In grid topology, nodes are placed in a uniform distance and gives better performance over random deployment for MANETs using PSM. Cooperative communication supports higher data rates and provides cooperative diversity. In this paper, the performance of the proposed Cooperative Modified Bellman Ford Algorithm for a grid network with PSM is investigated. In this algorithm, cooperative relays employing Modified Bellman Ford Algorithm (MBFA) are used to improve the performance of the network. The effect of Announcement of a Traffic Indication Message (ATIM) interval on packets received and energy consumption is calculated for different network sizes. Various performance metrics like packets received, energy consumed and delay for cooperative and non-cooperative scenarios are investigated with a different ATIM interval. Simulation results show that an ATIM interval of 16TUs gives better performance and a shorter ATIM interval saves node energy and improves the lifetime of the network. Page(s): 651-654

Fluorescence Transients as a Selection Tool for Marine Microalgal Consortia in a Raceway Pond Reactor for Biofuel Production

Sun, 01 Nov 2015 00:00:00 GMT

Title: Fluorescence Transients as a Selection Tool for Marine Microalgal Consortia in a Raceway Pond Reactor for Biofuel Production Authors: Sreekumar, N; Selvaraju, N; Aneesh, C; Haridas, A Abstract: In the search for renewable fuels, microalgae are seen as a potential source of oil that can be cultivated at large scale without competing with terrestrial food agriculture. Among the unsolved problems in the large scale production of microalgae for biofuel, is a rapid selection process based on lipid productivity. The fluorescence transients of consortia can be used as a measure of its lipid yield, thereby providing faster selection criteria. In order to test this hypothesis, a continuous (part harvested daily) raceway pond reactor with perpetual flocs containing microalgae consortia was developed. It is possible to select the dominant microalgal strains in the consortium by changing the process conditions. In this approach, process conditions that lead to higher lipid yield are desired. In this paper the photosynthetic activity of components of the algal consortia is measured by fluorescence transients and compared with lipid yield. It was found that, in our culture, brown microalga diatom dominant association had higher photosynthetic efficiency than a green filamentous microalgae association, and had higher lipid content. Page(s): 645-650

Design of Low Drop-Out voltage regulator

Sun, 01 Nov 2015 00:00:00 GMT

Title: Design of Low Drop-Out voltage regulator Authors: Naidu, K J; Kittur, H M; Avinash, P Abstract: An essential component of today’s battery powered SoC’s are power management systems which include Low Drop-Out (LDO) voltage regulators. LDO voltage regulators improve battery’s power efficiency and life. In this paper design and analysis of an LDO voltage regulator is presented. The designed LDO voltage regulator is designed with self-compensated error amplifier. It provides 30mA load current with a stable 1.6V output voltage. It consumes 172μA quiescent current and has a power efficiency of 88.38 % with dropout voltage of 200mV. Page(s): 641-644

Condition assessment of a prestressed concrete girder and slab bridge for increased axle loadings

Sun, 01 Nov 2015 00:00:00 GMT

Title: Condition assessment of a prestressed concrete girder and slab bridge for increased axle loadings Authors: Sundaram, B A; Parivallal, S; Kesavan, K; Ahmed, A K F; Ravisankar, K; Ramanjaneyulu, K; Iyer, N R Abstract: Our daily lives are becoming more dependent on civil infrastructure, including bridges, buildings, offshore structures, etc. Much of the existing infrastructure in India has been in service for many years. These structures continue to be in use, despite aging and associated damage. Hence, condition monitoring of these structures to provide necessary maintenance has become critical. The Indian Railway had requirement of increased freight haulage on the iron ore routes of various zonal railways. The Railway Board hence desired to undertake pilot project for operation of heavy axle freight wagons loaded upto 22.86 ton per axle. This proposed alteration may subject the bridges to higher tractive effort / braking forces (due to high power locos) together with higher axle loads. This proposed increase in load is acceptable only based on the available load capacity of the existing railway bridges. In this connection, condition assessment of a prestressed concrete slab bridge in service was carried out by adopting appropriate methodologies for instrumentation, testing and measurement. This paper describes the details of instrumentation adopted, various static and dynamic tests carried out and measurements taken during the investigation of the prestressed concrete slab bridge and also presents the results of the experimental investigation. Page(s): 634-640