Smart city roadway lighting system evaluation from driver's field of view

The latest Smart City roadway lighting technologies and their implementation in cities are being promoted as positive impacts on the quality of life within urban areas along with a sense of safety and security for drivers and pedestrians. Autonomous vehicles are a new addition to this complexity of infrastructure. This paper introduces a new methodology in the evaluation of Smart City lighting from the driver's field of view, and provides latest measured and simulated data that demonstrates the impact of roadway lighting on the driver's vision using 'Adaptation Luminance' function. The results show the drivers' eye adaptation luminance under dynamics of the roadway lighting conditions and reactions to technological innovation in vehicle design while adjusting to Smart City lighting conditions. Solutions aimed at removing the driver from routine operational decision-making are presented, while considering the street lighting design of the future along with in-vehicle lighting conditions

Smart city roadway lighting system evaluation from driver's field of view

The latest Smart City roadway lighting technologies and their implementation in cities are being promoted as positive impacts on the quality of life within urban areas along with a sense of safety and security for drivers and pedestrians. Autonomous vehicles are a new addition to this complexity of infrastructure. This paper introduces a new methodology in the evaluation of Smart City lighting from the driver's field of view, and provides latest measured and simulated data that demonstrates the impact of roadway lighting on the driver's vision using 'Adaptation Luminance' function. The results show the drivers' eye adaptation luminance under dynamics of the roadway lighting conditions and reactions to technological innovation in vehicle design while adjusting to Smart City lighting conditions. Solutions aimed at removing the driver from routine operational decision-making are presented, while considering the street lighting design of the future along with in-vehicle lighting conditions

Defining pedestrian's visual adaptation field under night lighting in Venice

Pedestrian areas use lighting systems with output at the mesopic level, which is situated between the photopic and scotopic. Studies have shown surrounding luminance effect on peripheral vision and its magnitude of the effect is larger than that of the foveal luminance. This study aims to examine this proposed model using real night time lighting conditions experienced by pedestrians in dark and narrow alleys and pathways close to water ways in the city of Venice. The eye tracking system and luminance scanning are used to measure such conditions while walking at night. The pedestrians' eye gaze angle data under non uniform background luminance show that peripheral luminance affect pedestrians' adaptation field differently given the pathways' geometry. Luminance adaptation data under mesopic lighting conditions contributes to the lighting system design while meeting the requirements with recommended practice for safe walkway lighting design

Experimental and theoretical study of a micro-fluidized bed

Published online 18 June 2013Large industrial scale fluidized beds (FBs) have been widely used because of their ability to greatly enhance mixing and both heat and mass transfer. This suggests that fluidized beds may offer a means of overcoming the poor mixing and transport characteristics of microfluidic devices where low Reynolds number flows prevail. We report experimental findings on liquid fluidization in microfluidic channels of 200-400 μm in size. Excellent fluidization is observed for various particles fluidized in ethanol where surface forces between the particles and the microfluidic channel are weak. In contrast, adhesion of the particles to the walls and subsequent de-fluidization is observed when water is used as the fluidizing medium. These findings demonstrate the importance of surface forces in micro-fluidized beds. We also find that conventional theories are able to explain the impact of surface forces on fluidization and, provided the effect of the walls on the particle packing and porosity is accounted for, the fluidization behavior. © 2013 AIP Publishing LLC.V. Zivkovic, M.N. Kashani and M.J. Bigg

Particle packing structure in a rectangular micro-capillary

Packed beds of micro-sized particles may be used for enhancing heat and mass transfer in microfluidic devices where Reynolds numbers are small. By increasing the surface area per unit volume, such micro-packed beds can also be used to significantly enhance the functionality of such devices. As the effectiveness of a packed bed is dictated by its packing structure, it is of interest to understand this structure and how it is affected by system parameters such as the channel-to-particle ratio - this has received little attention for micro-packed beds. In the work reported here, X-ray micro-computed tomography and image analysis is used to determine the packing structure of micro-packed beds of glass particles for channel-to-particle ratios of 5.19, 5.80, 6.56 and 7.55 in a channel of D = 200 mum square cross-section. The bed-average porosity was found to be far higher than macroscale PBs, vary from approximately 67% to 60% as the channel-to-particle ratio increased, with the packing structure and porosity varying both across the bed width and along its length. The former clearly arises from the effect of the wall, whilst the latter arises from the sedimentation method used to create the packed bed.M. Navvab Kashani, V. Zivkovic, Z. Alwahabi and M.J. Bigg