Effect of design factors for groynes on diversification of topography and restoration of ecosystems in straight and meandering streams

2020 ◽  
Vol 149 ◽  
pp. 105764 ◽  
Author(s):  
Seungjoon Chung ◽  
Dongho Choi ◽  
Gilson Hwang ◽  
Jinwook Chung
1989 ◽  
Vol 17 (3) ◽  
pp. 184-200 ◽  
Author(s):  
R. Hanada ◽  
T. Nagumo ◽  
T. Mashita

Abstract Automobile handling can be greatly improved by reducing the phase lag of tire cornering force behind imposed distortion. We have shown experimentally that this lag is related to in-plane stiffness of the belt and to radial, lateral, and circumferential stiffnesses of the sidewall. While the cornering stiffness is related to the belt rigidity, either can be changed without affecting the sidewall stiffnesses. The cornering stiffness, for example, is sensitive to design factors such as tread compound and tread pattern. The radial, lateral, and circumferential sidewall stiffnesses, however, are mutually perpendicular at a given point in a tire, so they cannot be changed independently of each other. In order to reduce the phase lag of the cornering force, the lateral and circumferential stiffnesses must be increased with a minimum increase in radial stiffness. This can be done by either lowering the radial location of the maximum section width of the inflated tire or by proper changes in material and/or design elements of the sidewall.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satish Rao Ganapathy ◽  
Hanim Salleh ◽  
Mohammad Khairul Azwan Azhar

AbstractThe demand for energy harvesting technologies has been increasing over the years that can be attributed to its significance to low power applications. One of the key problems associated with the available vibration-based harvester is the maximum peak power can only be achieved when the device frequency matches the source frequency to generate low usable power. Therefore, in this study, a magnetically-tunable hybrid piezoelectric-triboelectric energy harvester (MT-HPTEH) was designed and optimised. Four key design factors: mass placement, triboelectric surface area, extension length and magnetic stiffness were investigated and optimised. The voltage generation from piezoelectric and triboelectric mechanisms was determined individually to understand the effect of each design factor on the mechanisms. An output power of 659 µW at 180 kΩ at 44 Hz was obtained from the optimised MT-HPTEH with a theoretical–experimental discrepancy of less than 10%. The added magnetically-tunable feature enabled the harvester to work at the desired frequency range with an open circuit voltage between 7.800 and 20.314 V and a frequency range from 38 to 54 Hz. This MT-HPTEH can power at least six wireless sensor networks and can be used for low power applications such as RFID tags. Future work may include designing of energy-saving and sustainable harvester.


Clean Energy ◽  
2020 ◽  
Author(s):  
Bing Liu ◽  
Lixin He ◽  
Xianglong Zhao ◽  
Qiang Qin ◽  
Yi Guo

Abstract A vibration feeder is a piece of equipment for rationing and conveying powder, particle and block materials. In order to test the regeneration performance of de-dusting medium for high-temperature coal gas, a set of de-dusting medium-feeding systems was designed quantitatively. The de-dusting medium-feeding system is used in the gasification process for cleaning coal gas. The system is mainly composed of a hopper unit, control unit and feeding unit. In order to optimize the feeding stability of the coal-gas dust-removal medium vibration feeding system, the setting and scope of the following design factors and operating factors are investigated. Specifically, it includes the influence of gate-valve-opening adjustment of the control unit on the feeding stability of a vibrating feeding system; the influence of the gap size of the dipleg of the control unit on the feeding sensitivity of the vibration system; the influence of the particle size of the de-dusting medium on the operating range of the vibrating feeding system; the influence of the digitization of the working-current indicator of electromagnetic vibrating feeders on measurement variation and the process variation of a vibration feeding system. This vibration feeding system can realize the function of precise and quantitative feeding of the de-dusting medium, which can meet the design requirements of subsequent experimental research.


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