997,149 research outputs found

    An analytical model for bore-driven run-up

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    We use a hodograph transformation and a boundary integral method to derive a new analytical solution to the shallow-water equations describing bore-generated run-up on a plane beach. This analytical solution differs from the classical Shen-Meyer runup solution in giving significantly deeper and less asymmetric swash flows, and also by predicting the inception of a secondary bore in both the backwash and the uprush in long surf. We suggest that this solution provides a significantly improved model for flows including swash events and the run-up following breaking tsunamis

    An overview: effectiveness of different arrangement for electrode guard in electrical capacitance tomography

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    Electrical capacitance tomography (ECT) system is useful to obtain information about the spatial distribution of a dielectric materials mixture inside a vessel. It has been suggested by many researchers previously to use guard electrode in ECT sensors. This paper describes various types of design for guard electrode in Electrical Capacitance Tomography (ECT) sensor. The design of these electrode guards is vital to reduce crosstalk (undesired signals) between the adjacent electrodes (positioned at the outside of the measured pipe) since the crucial signals are only inside the pipe. There are three types of electrode guards designed by various researchers which are radial guard, axial guard with end guard and driven guard. The configuration and the effectiveness of each designed electrode are discussed. Other than that this paper introduced new design of electrode guards which are embedded on electrode sensor instead of placing separately between or around adjacent measuring electrodes as the previous design

    Protocol: optimised electrophyiological analysis of intact guard cells from arabidopsis

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    Genetic resources available for Arabidopsis thaliana make this species particularly attractive as a model for molecular genetic studies of guard cell homeostasis, transport and signalling, but this facility is not matched by accessible tools for quantitative analysis of transport in the intact cell. We have developed a reliable set of procedures for voltage clamp analysis of guard cells from Arabidopsis leaves. These procedures greatly simplify electrophysiological recordings, extending the duration of measurements and scope for analysis of the predominant K+ and anion channels of intact stomatal guard cells to that achieved previously in work with Vicia and tobacco guard cells

    Investigating the relation between optimum guard interval and channel delay spread for a MC-CDMA system

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    This paper demonstrates a novel approach to determining the optimum guard interval for a multicarrier code division multiple access (MC-CDMA) system. Analytical expressions for useful and interference power are derived as a basis for comparison. From these, an expression for the signal-to-noise ratio of a detected bit is derived and used to determine the optimum guard interval for a given channel profile and system parameters. In contrast to other works, we use channel models based on actual measurements and we highlight important differences from theoretical models to support our approach. From our results, we propose an empirical rule for optimum guard intervals given prevailing channel parameters. We show that the optimum guard interval can be selected as the delay window that includes 95% and 99% multipath power for Es /N0 = 10 dB and Es /N0 = 20 dB, respectively. In our case, the optimum guard interval was between 2 τrms and 4 τrms for Es /N0 = 10 dB and between 3 τrms and 6.4 τrms for Es/N0 = 20 dB

    Measurement of Impact Forces on Teeth and Jaw when Wearing Sports Mouth Guards

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    The objective of this project is to accurately measure the forces the teeth and jaw experience when subjected to impact. For this purpose piezoelectric technology (PVDF), which converts voltage to force and vice versa can be used to measure forces applied to teeth. A PVDF cable is calibrated and used for measuring force along with a control measuring device (PCB Piezotronics). The method involves wrapping the PVDF cable around a 3D home-printed, customized denture. The cable was chosen due to the fact that it allows for adequate fit between mouth guard and denture. Two masses, a baseball and 2 lbs - 3D printed projectile, were dropped from a height of 1m onto the denture with and without mouth guard. Results showed a significant force absorption by the mouth guard (more than 50% of initial impact force). After several trials, (n=10 for each group, baseball with and without mouthguard, as well as 2lbs), it was found that the impact shock absorption by the mouth guard ranged between 60-70%. Figure 1 shows the values at which the denture was impacted, with and without a mouth guard for baseball and 2 lbm cylinder. Finally, FEA Analysis was also used to show the regional stress and strain along the denture.https://scholarscompass.vcu.edu/capstone/1201/thumbnail.jp
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