First Comes Love. Then Comes Marriage. Then Comes A Baby In A Baby Carriage: An Application Of Protective Surrogacy Laws To The Tarheel State

Assisted Reproductive Technology (ART) and determining parentage have a common feature: each is governed by state law or the lack of such laws. This lack of statutory regulations presents significant legal challenges to gay men who wish to start a family. Because same-sex male couples seeking to become fathers through ART and surrogacy are the most likely demographic to be impacted when determining parentage, laws that influence the direction of surrogacy will undeniably facilitate whether both males will be deemed a father. To provide same-sex male couples with a pathway to parenthood, North Carolina should (1) develop robust, protective surrogacy laws and (2) adopt an intent-based approach when determining parentage

A numerical study of an inline oscillating cylinder in a free stream

Simulations of a cylinder undergoing externally controlled sinusoidal oscillations in the free stream direction have been performed. The frequency of oscillation was kept equal to the vortex shedding frequency from a fixed cylinder, while the amplitude of oscillation was varied, and the response of the flow measured. With varying amplitude, a rich series of dynamic responses was recorded. With increasing amplitude, these states included wakes similar to the Kármán vortex street, quasiperiodic oscillations interleaved with regions of synchronized periodicity (periodic on multiple oscillation cycles), a period-doubled state and chaotic oscillations. It is hypothesized that, for low to moderate amplitudes, the wake dynamics are controlled by vortex shedding at a global frequency, modified by the oscillation. This vortex shedding is frequency modulated by the driven oscillation and amplitude modulated by vortex interaction. Data are presented to support this hypothesis

Wake states and frequency selection of a streamwise oscillating cylinder

This paper presents the results of an in-depth study of the flow past a streamwise oscillating cylinder, examining the impact of varying the amplitude and frequency of the oscillation, and the Reynolds number of the incoming flow. These findings are presented in a framework that shows that the relationship between the frequency of vortex shedding fs and the amplitude of oscillation A* is governed by two primary factors: the first is a reduction of fs proportional to a series in A*2 over a wide range of driving frequencies and Reynolds numbers; the second is nonlinear synchronization when this adjusted fs is in the vicinity of N = (1 - fs/fd)-1, where N is an integer. Typically, the influence of higher-order terms is small, and truncation to the first term of the series (A*2) well represents the overall trend of vortex shedding frequency as a function of amplitude. However, discontinuous steps are overlaid on this trend due to the nonlinear synchronization. When fs is normalized by the Strouhal frequency fSt (the frequency of vortex shedding from an unperturbed cylinder), the rate at which fs/fSt decreases with amplitude, at least for fd/fSt = 1, shows a linear dependence on the Reynolds number. For a fixed Re = 175, the truncated series shows that the rate of decrease of fs/fSt with amplitude varies as (2 - fd/fSt)-1/2 for 1 < or egal fd/fSt < or egal 2, but is essentially independent of fd/fSt for fd/fSt < 1. These trends of the rate of decrease of fs with respect to amplitude are also used to predict the amplitudes of oscillation around which synchronization occurs. These predicted amplitudes are shown to fall in regions of the parameter space where synchronized modes occur. Further, for the case of varying fd/fSt, a very reasonable prediction of the amplitude of oscillation required for the onset of synchronization to the mode where fs = 0.5fd is given. In a similar manner, amplitudes at which fs = 0 are calculated, predicting where the natural vortex shedding is completely supplanted by the forcing. These amplitudes are found to coincide approximately with those at which the onset of a symmetric vortex shedding mode is observed. This result is interpreted as meaning that the symmetric shedding mode occurs when the dynamics crosses over from being dominated by the vortex shedding to being dominated by the forcing

Streamwise forced oscillations of circular and square cylinders

The modification of a cylinder wake by streamwise oscillation of the cylinder at the vortex shedding frequency of the unperturbed cylinder is reported. Recent numerical simulations [J. S. Leontini, D. Lo Jacono, and M. C. Thompson, “A numerical study of an inline oscillating cylinder in a free stream,” J. Fluid Mech. 688, 551–568 (2011)] showed that this forcing results in the primary frequency decreasing proportionally to the square of the forcing amplitude, before locking to a subharmonic at higher amplitudes. The experimental results presented here show that this behavior continues at higher Reynolds numbers, although the flow is three-dimensional. In addition, it is shown that this behavior persists when the body is a square cross section, and when the frequency of forcing is detuned from the unperturbed cylinder shedding frequency. The similarity of the results across Reynolds number, geometry, and frequency suggests that the physical mechanism is applicable to periodic forcing of the classic von Ka ́rma ́n vortex street, regardless of the details of the body which forms the street

Modification of three-dimensional transition in the wake of a rotationally oscillating cylinder

A study of the flow past an oscillatory rotating cylinder has been conducted, where the frequency of oscillation has been matched to the natural frequency of the vortex street generated in the wake of a stationary cylinder, at Reynolds number 300. The focus is on the wake transition to three-dimensional flow and, in particular, the changes induced in this transition by the addition of the oscillatory rotation. Using Floquet stability analysis, it is found that the fine-scale three-dimensional mode that typically dominates the wake at a Reynolds number beyond that at the second transition to three-dimensional flow (referred to as mode B) is suppressed for amplitudes of rotation beyond a critical amplitude, in agreement with past studies. However, the rotation does not suppress the development of three-dimensionality completely, as other modes are discovered that would lead to three-dimensional flow. In particular, the longer-wavelength mode that leads the three-dimensional transition in the wake of a stationary cylinder (referred to as mode A) is left essentially unaffected at low amplitudes of rotation. At higher amplitudes of oscillation, mode A is also suppressed as the two-dimensional near wake changes in character from a single- to a double- row wake; however, another mode is predicted to render the flow three-dimensional, dubbed mode D (for double row). This mode has the same spatio-temporal symmetries as mode A

A Modern Reinvestigation of the 1987 Moutere Depression Seismic Survey

The quality of seismic processing and interpretation in the past has always been shackled to the limitations of the acquisition equipment and analysis systems used. The variability of seismic processing between different projects has been due to the geophysicists own personal subjective preferences and interpretations. With the rapid development in computer processing power and technology, this project aims to refine the data processing of a regional data set collected in 1987 with modern methods, in a bid to better the geological understanding of the area and present it in a novel way. The original 1987 Vibroseis seismic survey involved eight seismic lines encompassing the entire Moutere Depression in Nelson, New Zealand. The target area is an elongated, NNE trending sedimentary basin that is infilled with primarily mid-Miocene to Pleistocene sediments. The age and depositional environment is similar to that of the neighbouring, hydrocarbon bearing Taranaki Basin in the north; it was this similarity that prompted the initial study. The data processing in this thesis was performed using the Globe ClaritasTM software package with the ultimate outputs being post-stack time migration. The project followed standard seismic practices and used conventional noise reduction methods such as frequency domain (FDFILT) and frequency-offset deconvolution (FXDECON) filters. New frequency-wavenumber and deconvolution filters native to Claritas such as QFK were also tested. Despite a range of filters being trialled, only one type of migration and gain compensator was applied, these were the Finite-Difference Migration and Automatic Gain Control respectively. After processing, the data was then imported into IHS KingdomTM to produce a 3D model of the basin. The six seismic horizons captured during interpretation were defined by their seismic facies. The upper layers were difficult to image due to ground roll and narrow frequency bandwidth sweeps. However, the lower horizons positioned between 500 ms – 2500 ms time depths were interpreted with higher confidence. The strongest reflection occurred with horizon three. The modelling showed a heavily folded and fractured formation with extensive reverse faulting and their corresponding antithetic splays, indicative of a compressive stress environment. The seismic processing goals of the project was moderately successful. Minor improvements in noise reduction were made using a combination of post- and pre- migration noise filtering. However, due to the poor resolution in the data itself blended with a lack of borehole data in the area, it was difficult to constrain the horizons and interpret the shallow sections accurately. This was a similar issue experienced in the two previous studies of the area. Regardless, my project was able to successfully recreate a 3D interpolated model of the Moutere Depression capturing its significant geological structures such as the Ruby Bay-Moutere and Waimea-Flaxmore faults and as a result, provide a unique perspective of the basin

Three-Dimensional Transition in the Wake of an Ellipse

The transition to three-dimensional flow from the nominally two-dimensional Ka ́rma ́n vortex street in the wake of bluff bodies is a problem of fundamental importance as it marks the first step on the path towards fully developed turbulence. Here, this transition is studied in the wake of an elliptical cross-section using Floquet stability analysis. A number of modes of instability are identified as a function of the aspect ratio of the ellipse. Three-dimensional simulations confirm the importance of the identified instability modes

The flow around stationary and elastically-mounted circular cylinders in tandem and staggered arrangements

A numerical study is presented of the flow around two circular cylinders in tandem and staggered arrangements in a freestream, examining the fluid forces and vortex-shedding behaviour, as well as the oscillation of both cylinders when allowed to move and vibrate in response to the flow. The streamwise distance between the cylinder centres is 1.5 diameters, while the cross-stream offset is varied from 0.0 to 5.0. The Reynolds number, based on cylinder diameter, D, and freestream velocity, U, is 200. Reduced velocity, U∗ = U , where fN is the fND spring natural frequency, is varied from 0.0 to 14.0. Results are obtained using a sharp-interface immersed boundary finite- difference method. For the stationary cylinders a range of be- haviours are observed over the cylinder offset range, includ- ing a difference in primary vortex-shedding frequency when the crossstream offset is greater than 1.5D. For the elastic- mounting, in contrast to existing results in the literature, three modes of vortex-shedding and oscillation are observed over the U∗ range for the tandem arrangement. These modes are dis- tinct in the phase difference between the front and rear cylinder oscillation, as well as the number of vortices shed from each cylinder