Ecological Impact Asessment and Ecological Monitoring of a Strategic Landfill-A case study in Hong Kong

This paper discusses ecological and monitoring studies covering vegetation, stream fauna, birds, mammals and other vertebrates at the West New Territories (WENT)Landfill, Hong Kong. Recommendations for the protection of vegetation on and around the site, including control of the erosion and run off from the construction site were proposed and implemented, resulting in effective protection of the local vegetation cover. Stream macrobenthos were low in species diversity and abundance and did not show a changing trend during the construction and the operation of the land fill. Birds attracted to the active dumping site were dominated by Crested Mynah Acridotheres cristatellus and the Tree Sparrow Passer montanus. After an increase in the population during the warmer months, the number of birds seen on the land fill site decreased to 10 in December 1994. Mammal monitoring by live trapping revealed that the rat population did not increase after the land fill operation started. This project was the first comprehensive’ ecological study and monitoring of an urban land fill in Hong Kong and it demonstrated that careful environmental planning and implementation of mitigation measures can successfully limit environmental impacts of landfills to acceptable levels.

Application of 3D Projection Profilometry in the High Speed Impaction Surface Deformation Measurement Research

In order to study the strength of the composite material plate problems, need to adopt a nondestructive testing method to obtain the specimen surface under the effect of high-speed impact regularity of shape. The projection profilometry was used to measure the surface profile or the full field deformation. Furtherly, by using the Fourier transform algorithm, there is only one frame of captured image which is needed in the measurement, so that it can be introduced into the high speed impaction procedure measurement. An experimental system, which was contained with an impact setup and the projection profilometry measurement part, was constructed for the impaction action characteristic research. The metallic impact object can be launched by a gas gun or a spin fan, respectively. The detected object is manufactured by composite materials. In order to increase the surface deformation measurement accuracy, the calibration method and the error was discussed with different calibration specimen. And then, the proposed profilometry measurement method is proved by the gas gun and spin fan projectile test. The surface deformation of the manufactured composite plates and fan case are measured in the impaction procedure. So that the impact action details can be described much more clearly than the traditional video monitoring method.

A low-power Bluetooth-based wireless sensor network and its global confliction-solving impact localization method

During the whole service lifetime of aircraft structures with composite materials,impacts are inevitable and can usually cause severe but barely visible damages.Since the occurrences of impact are random and unpredictable,it is a hotspot direction to develop an online impact monitoring system that can meet strict limitations of aerospace applications including small size,light weight,and low power consumption.Piezoelectric(PZT)sensor,being able to generate impact response signals with no external power and cover a large-scale structure with only a small amount of them,is a promising choice.Meanwhile,for real systems,networks with multiple nodes are normally required to monitor large-scale structures in a global way to identify any impact localization confliction,yet the existing studies are mostly evaluated with single nodes instead of networks.Therefore,in this paper,based on a new low-power node designed,a Bluetooth-based digital impact monitoring PZT sensor network is proposed for the first time with its global confliction-solving impact localization method.Evaluations of the system as a network are researched and analyzed on a complex real aircraft wing box for a global confliction-solving impact localization,showing a satisfying high accuracy.