scholarly journals Tidal propagation in an oceanic island with sloping beaches

2010 ◽  
Vol 14 (7) ◽  
pp. 1341-1351 ◽  
Author(s):  
Y.-C. Chang ◽  
D.-S. Jeng ◽  
H.-D. Yeh
Keyword(s):  
Analytical Solution ◽  
Water Table ◽  
Finite Length ◽  
Oceanic Islands ◽  
Higher Order ◽  
Oceanic Island ◽  
Tidal Propagation ◽  
Amplitude Parameter ◽  
Present Solution ◽  
Order Components

Abstract. In this study, a new analytical solution for describing the tide-induced groundwater fluctuations in oceanic islands with finite length and different slopes of the beaches is developed. Unlike previous solutions, the present solution is not only applicable for a semi-infinite coastal aquifer, but also for an oceanic island with finite length and different sloping beaches. The solution can be used to investigate the effect of higher-order components and beach slopes on the water table fluctuations. The results demonstrate the effect of higher-order components increases with the shallow water parameter or amplitude parameter and the water table level increases as beach slopes decrease.

scholarly journals Tidal propagation in an oceanic island with sloping beaches

2010 ◽  
Vol 7 (1) ◽  
pp. 1407-1430 ◽  
Author(s):  
Y. C. Chang ◽  
D. S. Jeng ◽  
H. D. Yeh
Keyword(s):  
Analytical Solution ◽  
Water Table ◽  
Finite Length ◽  
Oceanic Islands ◽  
Higher Order ◽  
Oceanic Island ◽  
Tidal Propagation ◽  
Amplitude Parameter ◽  
Present Solution ◽  
Order Components

Abstract. In this study, a new analytical solution for describing the tide-induced groundwater fluctuations in oceanic islands with finite length and different slopes of the beaches is developed. Unlike previous solutions, the present solution is not only applicable for a semi-infinite coastal aquifer, but also for an oceanic island with finite length and different sloping beaches. The solution can be used to investigate the effect of higher-order components and beach slopes on the water table fluctuations. The results demonstrate the effect of higher-order components increases with the shallow water parameter or amplitude parameter and the water table level increases as beach slopes decrease.

V.—Oceanic Islands

1881 ◽  
Vol 8 (2) ◽  
pp. 75-77
Author(s):  
T. Meelard Reade
Keyword(s):  
New Zealand ◽  
Oceanic Islands ◽  
Oceanic Island ◽  
The Pacific ◽  
Great Support ◽  
The Right ◽  
Tertiary Period

The Pacific and Atlantic Oceans far from the continental masses of land are studded with islands, which from their being solely volcanic and of an age going back no further than the Tertiary period, are considered to lend great support to the hypothesis of the permanence of the great oceans and continents. Those who hold these views question the right of New Zealand to be considered a truly oceanic island, though on what grounds has never been quite intelligible to me. Waiving this objection for the purpose of argumeat, I propose to discuss the bearings of the facts, as formulated by those who believe in the “approximate” immutability of land and sea.

scholarly journals Analysis of Groundwater Response to Oscillatory Pumping Test in Unconfined Aquifers: Consider the Effects of Initial Condition and Wellbore Storage

2018 ◽  
Author(s):  
Ching-Sheng Huang ◽  
Ya-Hsin Tsai ◽  
Hund-Der Yeh ◽  
Tao Yang
Keyword(s):  
Water Table ◽  
Integral Transform ◽  
Pumping Test ◽  
Hydraulic Head ◽  
Analytical Models ◽  
Hydraulic Parameters ◽  
Storage Effect ◽  
Initial Condition ◽  
Wellbore Storage ◽  
Present Solution

Abstract. Oscillatory pumping test (OPT) is an alternative to constant-head and constant-rate pumping tests for determining aquifer hydraulic parameters without water extraction. There is a large number of analytical models presented for the analyses of OPT. The combined effects of wellbore storage and initial condition regarding the hydraulic head prior to OPT are commonly neglected in the existing models. This study aims to develop a new model for describing the hydraulic head fluctuation induced by OPT in an unconfined aquifer. The model contains a typical flow equation with an initial condition of static water table, inner boundary condition specified at the rim of a finite-radius well for incorporating wellbore storage effect, and linearized free surface equation describing water table movement. The analytical solution of the model is derived by the Laplace transform and finite integral transform. Sensitivity analysis is carried out for exploring head response to the change in each of hydraulic parameters. Results suggest that head fluctuation due to OPT starts from the initial condition and gradually tends to simple harmonic motion (SHM) after a certain pumping time. A criterion for estimating the time to have SHM since OPT is graphically presented. The validity of assuming an infinitesimal well radius without wellbore storage effect is investigated. The present solution agrees well to head fluctuation data observed at the Boise hydrogeophysical research site in southwestern Idaho.

scholarly journals On the Application of the Multiple Scales Method on Electrostatically Actuated Resonators

2019 ◽  
Vol 14 (4) ◽  
Author(s):  
Saad Ilyas ◽  
Feras K. Alfosail ◽  
Mohammad I. Younis
Keyword(s):  
Analytical Solution ◽  
Multiple Scales ◽  
Excitation Frequency ◽  
Primary Resonance ◽  
Equation Of Motion ◽  
Higher Order ◽  
Resonance Excitation ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Electrostatically Actuated

We investigate modeling the dynamics of an electrostatically actuated resonator using the perturbation method of multiple time scales (MTS). First, we discuss two approaches to treat the nonlinear parallel-plate electrostatic force in the equation of motion and their impact on the application of MTS: expanding the force in Taylor series and multiplying both sides of the equation with the denominator of the forcing term. Considering a spring–mass–damper system excited electrostatically near primary resonance, it is concluded that, with consistent truncation of higher-order terms, both techniques yield same modulation equations. Then, we consider the problem of an electrostatically actuated resonator under simultaneous superharmonic and primary resonance excitation and derive a comprehensive analytical solution using MTS. The results of the analytical solution are compared against the numerical results obtained by long-time integration of the equation of motion. It is demonstrated that along with the direct excitation components at the excitation frequency and twice of that, higher-order parametric terms should also be included. Finally, the contributions of primary and superharmonic resonance toward the overall response of the resonator are examined.

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