Abstract: A general problem formulation for energy-efficient traffic engineering forfuture core networks is presented. Moreover, a distributed heuristic algorithmthat provides jointly load balancing and energy efficiency is proposed.Simulation results show that the proposed algorithm approaches the optimalnetwork operation, in terms of throughput and energy consumption.
Keywords: Network Management, Traffic Engineering, Load Balancing,Energy-awareness.
Electricity Generation and Biofilm Formation in Microbial Fuel Cells Using Plate Anodes Constructed from Various Grades of Graphite doi: https://doi.org/10.13052/jge1904-4720.412
Wudneh Ayele Shewa1, Subba Rao Chaganti2
and Jerald A. Lalman1
1Department of Civil and Environmental Engineering, University of Windsor,
Center for Engineering Innovation, 401 Sunset Ave., Windsor, ON, Canada,
N9B 3P4
2Great Lakes Institute for Environmental Research, University of Windsor,
401 Sunset Ave., Windsor, ON, Canada N9B 3P4
Abstract: [+] | Download File [ 2034KB ] | Read Article Online
Abstract: Construction materials as well as the electrode configuration are major factors
affecting electricity generation in microbial fuel cells (MFCs). Three graphite
plate electrodes (HK06, G347 and POCO3) with different characteristics (specific
resistance, grain size and specific gravity) were used to evaluate electricity
generation and biofilm formation in MFCs. The electrodes were assessed
by operating duplicate MFCs under the same conditions. Electrochemical
impedance spectroscopy, cyclic voltammetry and linear sweep voltammetry
were used to evaluate the performance of the electrodes. The data indicated
the grade of electrode played a critical role in the MFCs performance. Higher
power density was observed for the graphite electrode designated as POCO3.
The trend for increasing electricity generation was as follows: POCO3 >
G347 > HK06. Distinct microbial populations were detected in the biofilm
community when comparing the different electrodes. Selecting electrodes for
optimum electricity generation is important in the development of laboratory
scale and full-scale MFCs.
Keywords: Microbial fuel cell, Graphite plate electrode, Energy efficiency,
biofilm, Performance comparison.
Abstract: Ocean wave is one of the biggest sources of renewable energy that is
economically attractive. However, technology of harvesting wave power is
relatively undeveloped compared to other renewable energy technologies.
Finding optimal structures of wave energy converter (WEC) is still an open
research problem. The idea of using Stewart platform as a WEC is for the first
time proposed in this paper. Its key module is a Stewart platform, which is a
parallel mechanism with six degrees of freedom, used to convert the motion
induced by waves to the prismatic motions of multiple hydraulic/ pneumatic
cylinders. The proposed new type WEC can be used in the offshore wave
power generation systems and put in any place where there exist roaring
waves. The mathematical model has been set up and the numerical simulation
has been performed to verify the effectiveness of the proposed converter. The
simulation results show that more energy can be generated by this new type
of converter than other existing WECs.
Keywords: Wave Energy, Converter, Parallel Mechanism.
Comparison of Fully Pneumatic and Pneumatic - Electric Hybrid Configurations for Propulsion of A Refrigerated Vehicle doi: https://doi.org/10.13052/jge1904-4720.414
Midhun V.S1, A Ramesh2 and Sathyanandan M1
1M/S Nissan Ashokleyland Technologies Limited, No 19, Venkatanarayanan Road,
T Nagar, Chennai, India
2 I C Engines Laboratory, Mechanical Engineering Department, IIT Madras,
Chennai, India
Abstract: [+] | Download File [ 1615KB ] | Read Article Online
Abstract: Two different configurations of using a multistage air powered engine with
variable valve timing for powering a light transport vehicle were evaluated
through thermodynamic simulation. The expanded cold air between the stages
was used to refrigerate the cold space and thereby get reheated. However this
cannot meet the refrigeration load completely. Thus in the first configuration
the air engine provided the shaft power for propulsion and for additional
refrigeration. In the second configuration the air engine was connected in
parallel to a motor/generator and Li-ion battery. The total refrigeration load
was met by the expanded cold air between stages. The additional shaft power
available was used to charge the battery. After depletion of the compressed
air, the battery was used to provide shaft power and refrigeration. The range
of the hybrid configuration was evaluated to be slightly higher.
Keywords: Multistage expansion, variable valve timing, refrigeration,
hybrid layout.
Abstract: To accommodate user applications and requests, service providers host large computer systems over an infrastructure of distributed datacenters in different geographical locations. Consequently, energy and power consumption increases, increasing electrical and cooling costs. Hence more attention is paid to green computing and exploiting renewable energy sources, along with decreasing electrical costs so that these datacenters are operated efficiently and effectively, with less impact on the environment. In this paper, a socially responsible scheduling scheme that distributes load from several regions to geographically distributed datacenters will be extended. Optimal electricity, social and latency costs will be sought within service level agreements, ensuring fairness between different regions and highlighting its importance. Adopting standard gradient methods and Lagrange multipliers, an optimization algorithm called Green-Fair is proposed that provides optimal selection of datacenters. Experimental results show the effectiveness of the Green-Fair algorithm in utilizing green energy sources, reducing the number of SLA violations significantly, reducing latency costs and preserving fairness requirements by the SLAs while having little effect on the service providers’ overall operational costs.
Keywords: Datacenter,green computing, cloud computing,SLA, fairness, optimization, Lagrange.
