Suspended sediment transport can affect water quality and aquatic ecosystems, and its quantification is of the highest importance for river and watershed management. Suspended sediment concentration (SSC) and discharg...
详细信息
Suspended sediment transport can affect water quality and aquatic ecosystems, and its quantification is of the highest importance for river and watershed management. Suspended sediment concentration (SSC) and discharge were measured at two locations in the Estero Morales, a Chilean Andean stream draining a small basin (27 km(2)) hosting glacierized areas of about 1.8 km(2). Approximately half of the suspended sediment yield (470 t year(-1) km(-2)) was transported during the snowmelt period and half during glacier melting. The hysteresis patterns between discharge and SSC were calculated for each daily hydrograph and were analysed to shed light on the location and activity of different sediment sources at the basin scale. During snowmelt, an unlimited supply of fine sediments is provided in the lower and middle part of the basin and hysteresis patterns tend to be clockwise as the peaks in SSC precede the peak of discharge in daily hydrographs. Instead, during glacier melting the source of fine sediments is the proglacial area, producing counterclockwise hysteresis. It is suggested that the analysis of hysteretic patterns over time provides a simple concept for interpreting variability of location and activity of sediment sources at the basin scale. (C) 2016 Elsevier B.V. All rights reserved.
The modification of the radiation impedance load on each of two equal‐sized spherical‐shaped sources, one vibrating in the pulsating or n=0 mode and the other in the oscillating or n=1 mode has been calculated. Plot...
The modification of the radiation impedance load on each of two equal‐sized spherical‐shaped sources, one vibrating in the pulsating or n=0 mode and the other in the oscillating or n=1 mode has been calculated. Plots of the normalized resistive and reactive components of the modified radiation impedance are presented as a function of the wavelength size and separation of the two spheres.
An electropermanent suspension system is presented in this paper which can suspend a load of 491 grammes at an air-gap of 61 mm with a current as little as 173 mA. The system comprises an electromagnet with high energ...
详细信息
An electropermanent suspension system is presented in this paper which can suspend a load of 491 grammes at an air-gap of 61 mm with a current as little as 173 mA. The system comprises an electromagnet with high energy Neodymium-Iron-Boron magnets attached to the soft magnetic material core from both ends. Hall effect sensors are placed at the bottom of the electropermanent configuration which detect the magnetic field between the electropermanent magnet and the suspended load. The electronic circuitry of the sensors then ensure that the magnetic field is kept constant in the air-gap. The suspended load is also mounted with a high energy Neodymium-Iron-Boron magnet which adds to the already increased air-gap between the suspended load and the electropermanent magnet.
This work investigates partitioned iterative Solution of coupled multiphysics systems including subcycling time-stepping strategies for decoupled subsystems ill Conjunction with a proportional-integral-derivative feed...
详细信息
This work investigates partitioned iterative Solution of coupled multiphysics systems including subcycling time-stepping strategies for decoupled subsystems ill Conjunction with a proportional-integral-derivative feedback control algorithm for adaptive time-step selection. Some basic algorithms are proposed and the total computational effort to integrate to steady state is compared for a representative coupled flow and heat transfer problem to illustrate the approach and assess performance efficiency. Copyright (C) 2008 John Wiley & Sons, Ltd.
A volume hologram recorded with a lens array is proposed as a color transflective screen for Head Worn Display (HWD) systems. Design, fabrication as well as proof of concept are reported. Light from a single MEMS-base...
详细信息
A volume hologram recorded with a lens array is proposed as a color transflective screen for Head Worn Display (HWD) systems. Design, fabrication as well as proof of concept are reported. Light from a single MEMS-based projector is efficiently diffracted towards the eye with an angular spread given by the numerical aperture of the lenses forming the lens array. Using a dual-focus contact lens, full color high-resolution images are added to the HWD user's normal vision. A full color system with a 55 degrees lateral field of view is demonstrated. This screen offers the possibility for small footprint and large field of view HWD's.
In this paper, the development of constrained optimisation strategies for selecting the optimum cutting conditions for multi-pass rough turning operations on CNC and conventional lathes is outlined and discussed. The ...
详细信息
In this paper, the development of constrained optimisation strategies for selecting the optimum cutting conditions for multi-pass rough turning operations on CNC and conventional lathes is outlined and discussed. The analysis is based on the criterion typified by the maximum production rate and incorporates various relevant technological constraints. The approach adopted in arriving at the final solution involves a combination of theoretical economic trends and numerical search methods. Popular multi-pass solution strategies such as using all equal pass or all equal pass except one pass are shown to be useful approximations but the final computer-aided optimal solutions yielded unequal cutting conditions per pass. Numerical case studies reaffirmed the importance of using developed optimisation strategies rather than handbook recommendations, and demonstrated the effects of major variables as well as the superiority of multi-pass over single pass production rates.
暂无评论