scholarly journals Researches on energy conversion of municipal waste by plasma decomposition for energy-efficiency in civil engineering

2020 ◽  
Vol 789 ◽  
pp. 012035
Author(s):  
M L Lupu ◽  
D N Isopescu ◽  
I Cucoş ◽  
I Antonescu ◽  
S G Maxineasa ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Conversion ◽  
Civil Engineering ◽  
Municipal Waste ◽  
Plasma Decomposition

Size effect of SO2 receptors on the energy efficiency of Na–SO2 batteries: gallium-based inorganic electrolytes

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 105105-105109 ◽  
Author(s):  
Taeeun Yim ◽  
Goojin Jeong ◽  
Young-Kyu Han ◽  
Young-Jun Kim
Keyword(s):  
Energy Efficiency ◽  
Size Effect ◽  
Energy Conversion ◽  
Alternative Energy ◽  
High Performance ◽  
Storage Systems ◽  
Low Energy ◽  
Significant Attention

Na–SO2 batteries have garnered significant attention as alternative energy conversion/storage systems, however, their low energy efficiency, which corresponds to large polarization, is a crucial restriction in achieving high performance of the cell.

Maximum Energy-Efficiency Compliant Mechanism Design for Piezoelectric Stack Actuators

Aerospace ◽  
2003 ◽  
Author(s):  
Mostafa M. Abdalla ◽  
Mary Frecker ◽  
Zafer Gu¨rdal ◽  
Terrence Johnson ◽  
Douglas K. Lindner
Keyword(s):  
Energy Efficiency ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Compliant Mechanism ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Energy Conversion Efficiency ◽  
Maximum Energy ◽  
System Level ◽  
Voltage Source

Combined optimization of a compliant mechanism and a piezoelectric stack actuator for maximum energy conversion efficiency is considered. The paper presents a system level analysis in which the actuator and the compliant mechanism are mathematically described as linear two-port systems. The combination of stack and compliant mechanism is used to drive a structure, modeled as a mass-spring system. The analysis assumes all components to be free from dissipation, and the piezoelectric stack is driven by an ideal voltage source. Energy conversion efficiency is defined as the ratio of the output mechanical energy to the input electric energy. Theoretical bounds on the system efficiency are obtained. It is shown that the stack actuator can be optimized separately and matched to the specified structure and an optimally designed complaint mechanism. The optimization problem for the compliant mechanism is formulated to maximize a weighted objective function of energy efficiency and stroke amplification. Optimization results are presented for ground structures modeled using frame elements.

Energy Conversion Efficiency of Synthetic Jets

2011 ◽  
Author(s):  
Ri Li ◽  
Rajdeep Sharma ◽  
Mehmet Arik
Keyword(s):  
Energy Efficiency ◽  
Energy Conversion ◽  
Electric Power ◽  
Piezoelectric Actuators ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Signal Frequency ◽  
Laser Vibrometer ◽  
Zero Bias ◽  
Operation Conditions

Synthetic jets are driven by a periodic electrical signal to generate pulsated airflow that can provide cooling to a hot surface. The working principle of synthetic jets involves conversion of electrical energy into mechanical and fluid energy. Piezoelectric actuators, comprising of a thin metal substrate bonded to a piezoelectric disk are induced to undergo vibration motion in bending mode by an AC sine-wave voltage with zero bias. Synthetic jets, which consist of two piezoelectric actuators separated by a compliant ring at the outer periphery of the actuators, undergo a bellow-like action due to the periodic motion of the actuators, thereby ingesting air and pushing air at high velocities through the orifice. In this paper, we seek to understand and quantify the efficiency of synthetic jets with a view towards optimizing their design. In this study, energy efficiency of synthetic jet is defined based on thermodynamics principles. Analytical equations for calculating consumed electric power and airflow power are derived. Using the derived equations, energy efficiency of synthetic jets is experimentally investigated. Air velocity at the jet orifice is measured using constant temperature hotwire anemometry. Voltage signal and resultant current waveform are recorded to calculate electric power. In order to understand the structural behavior, laser vibrometer is used to measure the center out-of-plane deflection of the piezoelectric synthetic jet. Electrical power input is varied by changing signal frequency and voltage amplitude. Synthetic jets with two different orifice sizes are tested, and the efficiency of energy conversion is determined. The effects of jet design and operation conditions on energy efficiency are discussed.

scholarly journals Decaffeination process characteristic of Robusta coffee in single column reactor using ethyl acetate solvent

2009 ◽  
Vol 26 (3) ◽  
Author(s):  
Sukrisno Widyotomo ◽  
Sri Mulato ◽  
Hadi K. Purwadaria ◽  
A.M Syarief
Keyword(s):  
Energy Efficiency ◽  
Solar Radiation ◽  
Solar Energy ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Radiation Intensity ◽  
Energy Conversion Efficiency ◽  
Solar Radiation Intensity ◽  
Solar Energy Conversion Efficiency ◽  
Shading Plant

AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L.), Krete (Cassia surattensis (Burm.) F.), Lamtoro (Leucaena leucocephala L.) and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity) between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method

scholarly journals How to achieve Nearly zero-energy buildings standard

2020 ◽  
Vol 72 (08) ◽  
pp. 703-720
Keyword(s):  
Energy Efficiency ◽  
Engineering Design ◽  
Civil Engineering ◽  
Zero Energy ◽  
Basic Principles ◽  
Building Envelopes ◽  
Good Communication ◽  
Zero Energy Buildings

The implementation of the Nearly zero-energy buildings (NZEB) standard has enabled significant developments in the design and realisation of external building envelopes, which have the greatest influence on the quality of buildings in the sense of energy efficiency. Experience has shown that prerequisites for good-quality realisation of works mainly include competent and motivated workforce, appropriate equipment, and good communication between all participants in construction. Basic principles of architectural and civil engineering design and realisation of NZEB projects are presented, and problems occurring and possibly resulting in construction damage are presented in the paper.

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