scholarly journals Jumping in lantern bugs (Hemiptera, Fulgoridae)

2021 ◽  
Author(s):  
M. Burrows ◽  
A. Ghosh ◽  
G. P. Sutton ◽  
H. M. Yeshwanth ◽  
S. M. Rogers ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Expenditure ◽  
Power Output ◽  
High Speed ◽  
Jumping Performance ◽  
Power Amplification ◽  
Amplification Mechanism

Lantern bugs are amongst the largest of the jumping hemipteran bugs with body lengths reaching 44 mm and their masses 0.7 g. They are up to 600 times heavier than smaller hemipterans that jump powerfully using catapult mechanisms to store energy. Does a similar mechanism also propel jumping in these much larger insects? The jumping performance of two species of lantern bugs (Hemiptera, Auchenorrhyncha, family Fulgoridae) from India and Malaysia was therefore analysed from high-speed videos. The kinematics showed that jumps were propelled by rapid and synchronous movements of both hind legs with their trochantera moving first. The hind legs were 20-40% longer than the front legs, which was attributable to longer tibiae. It took 5-6 ms to accelerate to take-off velocities reaching 4.65 m s−1 in the best jumps by female Kalidasa lanata. During these jumps, adults experienced an acceleration of 77 g, required an energy expenditure of 4800 µJ, a power output of 900 mW and exerted a force of 400 mN. The required power output of the thoracic jumping muscles was 21,000 W kg−1, 40 times greater than the maximum active contractile limit of muscle. Such a jumping performance therefore required a power amplification mechanism with energy storage in advance of the movement as in their smaller relatives. These large lantern bugs are near isometrically scaled up versions of their smaller relatives, still achieve comparable, if not higher, take-off velocities, and outperform other large jumping insects such as grasshoppers.

Photoenergy storage and power amplification strategy in membrane-less photoelectrochemical biofuel cells

2016 ◽  
Vol 52 (40) ◽  
pp. 6716-6719 ◽  
Author(s):  
You Yu ◽  
Miao Xu ◽  
Shaojun Dong
Keyword(s):  
Energy Storage ◽  
Power Output ◽  
High Efficiency ◽  
Biofuel Cells ◽  
Power Amplification ◽  
Higher Power ◽  
Amplification Strategy

We proposed a novel integrated PBFC by insetting a third electrode with high efficiency energy storage and release between the bioelectrode and the photoelectrode, resulting in a higher power output than that of the original PBFC.

Jumping, Climbing and Suspensory Locomotion

2018 ◽  
Keyword(s):  
Energy Storage ◽  
Elastic Energy ◽  
The Core ◽  
Power Amplification ◽  
Core Concepts

Jumping, climbing and suspensory locomotion are specialized locomotor mechanisms used on land and in the air. Jumping is used for rapid launches from substrates. Climbing and suspensory movements enable locomotion up, under and through vertically-structured habitats, such as forests. Elastic energy storage is particularly important for jumping and catapult systems and we address the core concepts of power amplification that are exemplified in nature’s extreme jumpers. We examine the diverse mechanisms of attachment that characterize animals that can grasp and adhere to a diversity of structures. We conclude the chapter by examining the integration of biological capabilities with engineering innovations in these systems.

Coupling anodic/cathodic energy storage through in-situ heterostructure regulation of ordered microporous carbon for sodium-ion hybrid capacitors

2021 ◽  
Author(s):  
Juan Li ◽  
Bo Wang ◽  
Tianzhao Hu ◽  
Yuzuo Wang ◽  
Zhenhua Sun ◽  
...  
Keyword(s):  
Energy Storage ◽  
Power Output ◽  
Microporous Carbon ◽  
Sodium Ion ◽  
Faradaic Reaction ◽  
Hybrid Capacitors

Sodium-ion hybrid capacitors are emerging as the promising energy storage and power output devices. However, they suffer from sluggish faradaic reaction of anode and low capacity of cathode. Zeolite-templated carbons...

scholarly journals Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping

2011 ◽  
Vol 8 (3) ◽  
pp. 386-389 ◽  
Author(s):  
Henry C. Astley ◽  
Thomas J. Roberts
Keyword(s):  
Energy Storage ◽  
Elastic Energy ◽  
High Speed ◽  
Angular Acceleration ◽  
Whole Body ◽  
Joint Motion ◽  
Joint Movement ◽  
Fascicle Length ◽  
Muscle Fascicle ◽  
Muscle Shortening

Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid joint movement during the jump without rapid muscle-shortening (during tendon recoil). During all jumps, muscle fascicles shortened by an average of 7.8 per cent (54% of total strain) prior to joint movement, stretching the tendon. The subsequent period of initial joint movement and high joint angular acceleration occurred with minimal muscle fascicle length change, consistent with the recoil of the elastic tendon. These data support the plantaris longus tendon as a site of elastic energy storage during frog jumping, and demonstrate that catapult mechanisms may be employed even in sub-maximal jumps.

Leakage flow characteristic of radial inflow turbine adopted in CAES system: Review on progress

2021 ◽  
pp. 095440622110276
Author(s):  
Xing Wang ◽  
Xuehui Zhang ◽  
Yangli Zhu ◽  
Ziyi Shao ◽  
Wen Li ◽  
...  
Keyword(s):  
Energy Storage ◽  
Power Output ◽  
Flow Characteristic ◽  
Tip Clearance ◽  
Inlet Temperature ◽  
Leakage Flow ◽  
Operation Condition ◽  
Loss Mechanism ◽  
Flow Loss ◽  
Radial Inflow Turbine

Compressed Air Energy Storage (CAES) System is an important power output component of the energy storage technology. Radial inflow turbine is the main power output device in CAES system, it is operated at extraordinary operation condition (inlet pressure ≥ 75 bar and inlet temperature < 500 K) which is different from gas turbine and other turbomachinery. Therefore, clearance existing in the CAES radial inflow turbine will result in special leakage flow characteristic and higher flow loss, which decreases the aerodynamic performance and the economic efficiency of the CAES system. However, most of researches for CAES radial inflow turbine mainly focus on the performance prediction of CAES system with one-dimensional model, the detailed leakage flow loss mechanism based on three-dimensional analysis, which significantly influences the flow structure and efficiency, are still needed to be further conducted. In present study, the progress on leakage flow characteristic in the CAES radial inflow turbine is reviewed. The effects of tip clearance, case-shroud clearance and back cavity of rotors are summarized, the leakage flow mechanism and loss reduction method are also analyzed and discussed. Suggestions for the future work on leakage flow of CAES radial inflow turbine are also proposed. The present review can provide a guide for new design and optimization of the radial inflow turbine adopted in CAES system.

Exercise efficiency: validity of base-line subtractions

1980 ◽  
Vol 48 (3) ◽  
pp. 518-522 ◽  
Author(s):  
W. N. Stainbsy ◽  
L. B. Gladden ◽  
J. K. Barclay ◽  
B. A. Wilson
Keyword(s):  
Energy Storage ◽  
Energy Expenditure ◽  
Work Rate ◽  
Published Data ◽  
Base Line ◽  
External Work ◽  
Future Studies ◽  
Using Data ◽  
Exercise Efficiency ◽  
Adequate Analysis

In evaluating the efficiency of humans performing exercise, base-line subtractions have been used in an attempt to determine the efficiency of the muscles in performing the external work. Despite the fact that base lines have been criticized previously, they have been widely used without adequate analysis of the implications involved. Calculations of efficiencies using data available in the literature for isolated muscle preparations revealed that base-line subtractions result in unreasonably high efficiencies. This suggests strongly that the base lines are invalid. To be valid, a base line must continue unchanged under all the conditions in which it is applied. Previously published data indicate clearly that exercise base lines change with increasing work rate and are therefore invalid. The use of base lines is further complicated by elastic energy storage in some types of exercise. Although exercise efficiencies using base line subtractions may be useful, they do not indicate muscle efficiency. Perhaps future studies of exercise metabolism should be directed less at refining base lines and more toward describing and quantifying the determinants of energy expenditure.

scholarly journals Achieving High-Speed Retraction in a Stretchable Hydrogel

2020 ◽  
Author(s):  
Rosa Maria Badani Prado ◽  
Satish Mishra ◽  
Buckston Morgan ◽  
Rangana Wijayapala ◽  
Seyed Meysam Hashemnejad ◽  
...  
Keyword(s):  
High Speed ◽  
Biological Tissues ◽  
Biological Species ◽  
Vital Role ◽  
Polypropylene Glycol ◽  
Glycol Diacrylate ◽  
Mantis Shrimp ◽  
Power Amplification ◽  
Short Period ◽  
Very High

Many biological species apply the power amplification mechanism for locomotion, feeding, and protection. In power amplification, a biological system rapidly releases stored-energy by achieving a very high velocity over a short period of time, resulting in high power output. Such power amplification allows insects such as locust to jump and Mantis shrimp to kill prey by its appendage strike. Biological elastomeric polymers such as resilin play a vital role in the power amplification process because of their high stretchability and resilience. In synthetic materials, although<br>crosslinked rubbers display high stretchability and resilience, such is difficult to achieve in the water-containing systems such as in hydrogels, commonly considered materials for mimicking biological tissues. Here, we have used a simple free-radical polymerization of acrylic acid (AAc), methacrylamide (MAAm), and polypropylene glycol diacrylate (PPGDA) to obtain hydrogels. In these gels, the polymerized AAc and MAAm act as hydrophilic blocks and PPG as hydrophobic, and the gel structure resemble that of resilin consisting of hydrophilic and hydrophobic components. The bioinspired gels display very high stretchability, as high as eight times the original length, and greater than 90% resilience. In addition, the gel samples can reach a retraction velocity of 16 m/s with an acceleration of 4X10^3 m/s2. These values are similar or better than those observed in water containing biological systems, such as appendage strikes in Mantis shrimp, etc. To the best of our knowledge, such performance has not been reported in the<br>literature for any water containing networks.

A Comparative Study of Methane Combustion Characteristics with Different Additions in an Optical SI Engine

2021 ◽  
Author(s):  
Lin Chen ◽  
Xiao Zhang ◽  
Ren Zhang ◽  
Wanhui Zhao
Keyword(s):  
Natural Gas ◽  
Flame Propagation ◽  
Power Output ◽  
High Speed ◽  
Propagation Speed ◽  
Pressure Oscillation ◽  
Methane Combustion ◽  
Natural Gas Engines ◽  
Auto Ignition ◽  
Flame Propagation Speed

Abstract Natural gas is a promising fuel for IC engines with minimal modification, whereas its low power output and slow flame propagation speed remain a challenge for automobile manufacturers. To find a method of improving the natural gas engines, methane combustion with different additions was comparatively studied. High-speed direct photography and simultaneous pressure were performed to capture detailed combustion evolutions. First, the results of pure methane combustion confirm its good anti-knock property, and no pressure oscillation occurs even there is an end-gas auto-ignition, indicating that high compression ratio and high boosting are effective ways to improve the performance of natural gas engines. Second, adding heavy hydrocarbons can greatly improve engines' power output, but engine knock should be considered if low anti-knock fuel was used. Third, as a carbon-free and gaseous fuel, hydrogen addition can not only increase methane flame propagation speed but reduce cyclic variations. However, a proper fraction is needed under different load conditions. Last, oxygen-enriched combustion is an effective way to promote methane combustion. The heat release becomes faster and more concentrated, specifically, the flame propagation speed can be increased by more than 2 times under 27% oxygen concentration condition. The current study shall give insights into improving natural gas engines' performance.

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