A WSN is a specialized wireless network made up of large number of sensors and at least one base station. The foremost or the main difference between WSN and the traditional wireless networks is that sensors are extremely sensitive to energy consumption. Energy saving in the crucial issue in designing the wireless sensor networks [12]... Since the radio transmission and reception consumes more energy, one of the most or the main significant issue in wireless sensor network is the inherent limited battery power within network sensor nodes. It is preferable to dispense the energy throughout the wireless sensor network so to maximize the lifetime of sensor nodes. So it is essential to design effective and energy aware protocols in order to enhance the life time of the network. A wireless sensor network may have network structure based or protocol operation based routing protocol. In this paper, a review on hierarchical based routing protocol which is further a sub-type of the network structure based routing protocol in WSNs is carried out. Major issues which are considered in WSNs are Energy consumption and network life time.
Keywords: - Energy consumption, Wireless, Sensor network, routing protocols, energy efficient, network life time, sensor, battery, life.
[1] Wiley, 2010] Fundamentals of Wireless Sensor Networks - Theory and Practice
[2] Harneet Kour and Ajay K. Sharma, "Hybrid Energy Efficient Distributed Protocol for Heterogeneous Wireless Sensor Network", International Journal of Computer Applications (0975 – 8887) Volume 4 – No.6, July 2010.
[3] I.F. Akyildiz, W. Su*, Y. Sankarasubramaniam, E. Cayirci, "Wireless sensor networks: a Survey", Broadband and Wireless Networking Laboratory, School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
[4] Ossama Younis and Sonia Fahmy. 2004. Distributed Clustering in Ad-hoc Sensor Networks: A Hybrid, EnergyEfficient Approach. In Proceedings of IEEE INFOCOM, Hong Kong, an extended version appeared in IEEE Transactions on Mobile Computing, 3(4)
[5] W. Heinzelman, A. Chandrakasan and H. Balakrishnan. 2000. Energy-Efficient Communication Protocol for Wireless Microsensor Networks. Proceedings of the 33rd Hawaii International Conference on System Sciences (HICSS '00).
We achieved low-resistance nonalloyed Ohmic contacts for n-type GaN using selective area growth (SAG) by plasma assisted molecular beam epitaxy (PAMBE). Thus-fabricated high electron mobility transistor (HEMT) demonstrated comparable or more favorable electrical performance than the conventional alloyed counterpart. Meanwhile, the nonalloyed PAMBE-SAG technique avoids problems created by the high temperature annealing, such as the lateral diffusion of contact metals and the generation of surface defects. Consequently, ultrafine electrodes are realized for device downscaling, defect-induced current degradation is alleviated, the reliability and uniformity of HEMTs are improved.
Keywords: - AlGaN/GaN HEMT; Nonalloyed Ohmic contacts; Selective area growth; Plasma assisted molecular beam epitaxy; Defects
[1] N. Tipirneni, A. Koudymov, V. Adivarahan, J. Yang, G. Simin, and M. A. Khan, The 1.6-kV AlGaN/GaN HFETs, IEEE Electron Device Lett. 27(9), 2006, 716-718.
[2] J. W. Chung, J. Lee, E. L. Piner, and T. Palacios, Seamless on-wafer integration of Si(100) MOSFETs and GaN HEMTs", IEEE Electron Device Lett. 30(10), 2009, 1015-1019.
[3] L. Pang and K. Kim, Bimodal gate-dielectric deposition for improved performance of AlGaN/GaN metal–oxide–semiconductor high-electron-mobility transistors, J. Phys. D: Appl. Phys. 45, 2012, 045105.
[4] L. Pang, Y. G. Lian, D. S. Kim, J. H. Lee, and K. Kim, AlGaN/GaN MOSHEMT With High-Quality Gate–SiO2 Achieved by Room-Temperature Radio Frequency Magnetron Sputtering, IEEE Trans. Electron Devices, 59(10), 2012, 2650-2655.
[5] D. F. Wang, F. S. Wei, C. Lu, A. Motayed, M. Jah, S. N. Mohammad, K. A. Jones, and L .S. Riba, Low-resistance Ti/Al/Ti/Au multilayer ohmic contact to n-GaN, J. Appl. Phys., 89(11), 2001, 6214-6217.
A laboratory experiment was set up in small chambers for monitoring greenhouse gas emissions and
determining the most suitable time for sampling. A six-treatment experiment was conducted, including a one
week pre-incubation and a week for incubation. Timelines for sampling were 1, 2, 3, 6 and 24 hours after
closing the lid of the incubation chambers. Variation in greenhouse gas fluxes was high due to the time of
sampling. The rates of gas emissions increased in first three hours and decreased afterward. The rates of
greenhouse gas emissions at 3 hours after closing lids was close to the mean for the 24-h period.
Keywords: - biochar, chamber, Ferrosol soil, incubation, sampling
This paper describes the simulation result of biomass gasification-based crematory's secondary
combustion chamber via CFD analysis. The chamber models, which were rectangular and cylinder type, were
implemented, whereas ANSYS FLUENT with standard k-omega viscous model and SIMPLE algorithm were
taken place. The results show that an average residence time of gas and particle if simulating by using
rectangular chamber displays as 2 and 3 second, respectively, whereas the average residence time of cylinder
chamber type presents 2 second for particle and 4 second for gas. Furthermore, the residence time of cylinder
chamber type can be increased by lengthening the chamber's height, which the benefits, such as efficient
pollution control, will be earned.
Keywords: - Biomass, Computational Fluid Dynamics, Cremation, Gasification, Producer Gas, Residence Time
Considering the options for waste rubber - reduction, reuse, recycling, energy recovery and storage in landfills - there is a clear trend towards the renewing of energy. The use of waste tire as an alternative fuel reduces the amount of old tires, protect natural resources and increasing energy independence. In many cases, this is a reasonable option.There are lots of of sustainable options, extensive use of old tire that exist today and that will grow (using rubber granules in retreaded asphalt mixed with caoutchouc to manufacture various rubber products, various applications in the construction industry). Based on the analysis method for recycling rubber products, there is a great diversity in the quality and quantity of recycled material. And it is of primary importance for use in new tires. Methodology production costs optimization, and quality control require further research and efforts to standardize these processes.
Keywords: - rubber, tire, recycling, waste.
Sol–gel materials may found plenty of applications, carriers for various substances, which can be exploited for sensing purposes or as drug releasing carriers. In this work, the fluorescence properties of two photo sensitizers immobilized in silica based sol–gel materials were examined. Sol-gel derived silica possess many promising features, including room-temperature preparation procedure, porosity, chemical and physical stability. The material preparation procedure is described and practical remarks on silica-based sol-gels are included. It is reported that sol-gels with entrapped various molecules may be used in construction of implants and coatings with bioactive properties. It is shown how to exploit the sol-gel production route for construction of sol-gel coated fiber optic applicators for chemical sensor. We used a Sodium silicate(Na2 O3 Si) instead of the Tetraethyl Ortho Silicate (TEOS ) (Si (OC2 H5)4).We study the optical characteristics for this sample. The sol gel was tested to detect ammonia gas.
Keyword : Sol-Gel , Silicate Sodium, Amonia ,Bromocresol purple
A fiber optic sensor for detection nitrite compound in water was described. The fiber sensor is based on evanescent field absorption in a test sample formed by reaction of nitrite compound in water with suitable chemical regents. A 12cm unclad part of a plastic clad silica fiber act as the sensing region . The experimental results shows the successfully this techniques for monitoring the nitrite in drinking water.
Keyword: - optical fiber sensor ,pollution detection ,chemical fiber sensor developed for routine chemical analysis. Many of these techniques offer high specificity and sensitivity. (b). The low attenuation of optical fibers enables the remote in-situ sensing of species in difficult or hazardous environments.
The goal of this paper is to extend the study of Stonean residuated lattices ([8]), we introduce the
notions of i-filter's radical and boolean i-filter in Stonean residuated lattices and we put in evidence some specific
properties of those .
Keywords: Residuated lattice, i-filter, prime i-filter, maximal i-filter 2010 MSC: 03G10, 03G25, 06D05, 06D35, 08A72.
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