Volume and Issue Articles
Back to ArchivesVolume 4, Issue 6
November-December 2016
A SURVEYON CLUSTERING BASED ROUTING PROTOCOLS FOR HETEROGENEOUS WIRELESS SENSOR NETWORKS
Abstract: —Energy consumption is major constraint in Wireless Sensor Networks (WSNs). Till now, numerous routing protocols have been investigated to achieve the energy efficiency. Earlier communication protocols were proposed, which can have large impact on the overall consumption of these networks.These conventional protocols such as direct transmission, minimum-transmission-energy, multi-hop routing, and static clustering may not be suitable for sensor networks.LEACH was proposed to overcome the problems of conventional protocols. In LEACH, cluster heads are randomly rotated in order to divide energy load among all nodes. There are so many protocols which follows the same operation as LEACH. This paper reviews on hierarchical based clustering and evolutionary protocols for heterogeneous WSNs to provide better energy efficiency.
ASPHALT PAVEMENT MATERIAL IMPROVEMENT: A REVIEW
Abstract: From the beginning of asphalt mixture design it was desired to understand the interaction of aggregates, asphalt, and the voids created during their compaction. In asphalt mixture design, guidance is lacking in the selection of the design aggregate structure and understanding the interaction of that aggregate structure and mixture volumetric properties. This paper presents mixture design concepts that utilize aggregate interlock and aggregate packing to develop an aggregate blend that meets volumetric criteria and provides adequate compaction characteristics. The presented concepts rely on coarse aggregate for the skeleton of the mixture with the proper amount of fine aggregate to provide a properly packed aggregate structure. The objective is to utilize aggregate packing concepts to analyze the combined gradation and relate the packing characteristics to the mixture volumetric properties and compaction characteristics. The presented concepts include an examination of aggregate packing and aggregate interlock, blending aggregates by volume, a new understanding of coarse and fine aggregate, and an analysis of the resulting gradation. This study presents comprehensive mix analysis concepts for developing and analyzing hot mix asphalt gradations. It is presented through a rational approach to the selection of relative amounts of coarse and fine aggregate. Evaluation of gradation with aggregate ratios provides a new tool for examining aggregate gradations. These ratios, based on particle packing, provide distinct relationships with the resulting mixture volumetrics and compaction characteristics. The results of this study improve the state-of-the-art in asphalt mix design and production by providing a method to characterize HMA mixture volumetrics and compaction characteristics through the fundamental principles of particle packing. The design concepts outlined in this study provide the foundation for a comprehensive asphalt mixture design method: The Bailey Method of Gradation Analysis and Asphalt Mix Design.
EVALUATION OFINTERFACE BOND CONDITION BETWEEN TWO BITUMINUOS LAYERS
Abstract: This study is to evaluate the bonding shear stress between asphalt pavement layered structures with emulsion and cutback asphalt as tack coat materials. A simple direct shear test device is set up for testing the shear force of the pavement composite interface. The test results show that the shear force decreases with an increase in temperature. It had a maximum value at optimum application rate and the emulsion asphalt used exhibited higher shear force than that of cutback asphalt. The shear stress model represented by exponential equations between shear stress and temperature is reasonable and is not significantly different to the shear stress from experimental field test, in accordance with the statistic of analysis of variance test. The shear stress modeling developed in this paper provides a valuable method to simulate the shear stress of a different nominal aggregate gradation and tack coat material.