Sweethearts of Boyhood Days

https://digitalcommons.library.umaine.edu/mmb-vp/6571/thumbnail.jp

Data Combinations Accounting for LISA Spacecraft Motion

LISA is an array of three spacecraft in an approximately equilateral triangle configuration which will be used as a low-frequency gravitational wave detector. We present here new generalizations of the Michelson- and Sagnac-type time-delay interferometry data combinations. These combinations cancel laser phase noise in the presence of different up and down propagation delays in each arm of the array, and slowly varying systematic motion of the spacecraft. The gravitational wave sensitivities of these generalized combinations are the same as previously computed for the stationary cases, although the combinations are now more complicated. We introduce a diagrammatic representation to illustrate that these combinations are actually synthesized equal-arm interferometers.Comment: 10 pages, 3 figure

Design and Integration of a Laser-Based Materials Deposition System

This paper aims to demonstrate the design process of an integrated five-axis Laser-Based Material Deposition (LBMD) system for rapid prototyping application. Several design evaluation methods are selected and applied to the design of the system. A three-dimensional graphical simulation software package was used as a decision making aid and as an analysis tool in the design process. Hardware integration of a five-axis computer numerical controlled (CNC) vertical milling machine, a 2.5 KW Nd:YAG laser and a linear table is discussed. A brief introduction to the system software and control architecture is also summarized. Some important design issues and considerations specific to Laser Based Material Deposition process are suggested.Mechanical Engineerin

High speed imaging of Raleigh-Taylor instabilities in laser driven plates

Recent improvements and modifications of the imaging techniques have identified and provided measurements of Raleigh-Taylor (R-T) instabilities that occur in these events. The microscope system in the LLNL Micro Detonics Facility, was converted to an epi-illuminated polarization configuration. A double pulse nanosecond illuminator and a second independently focusable frame camera were also added to the system. A laser driven plate, that is a dense solid driven by a laser heated, lower density plasma, is inherently R-T unstable. The plates are aluminum, deposited on the ends of optical fibers. They are launched by a YAG Laser pulse traveling down the fiber. Plate velocities are several kilometers per second and characteristic dimensions of the instabilities are a few to tens of microns. Several techniques were used to examine the plates, the most successful being specularly reflecting polarization microscopy looking directly at the plate as it flies toward the camera. These images gave data on the spatial frequencies of the instabilities but could not give the amplitudes. To measure the amplitude of the instability a semi- transparent witness plate was placed a known distance from the plate. As above, the plate was observed using the polarization microscope but using the streak camera as the detector. Both the launch of the plate and its impact into the witness plate are observed on the streak record. Knowing the plate velocity function from earlier velocimetry measurements and observing the variations in the arrival time across the plate, the amplitude of the instability can be calculated

White Matter Microstructural Damage on Diffusion Tensor Imaging in Cerebral Small Vessel Disease

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We haven't got a seat on the bus for you or All the seats are mine: Narratives and career transitions in professional golf

In this article we explore how the stories an athlete tells throughout life in sport affect her career transition experiences. We base our enquiry on a social constructionist conception of narrative theory which holds that storytelling is integral to the creation and maintenance of identity and sense of self. Life stories were gathered through interviews with two professional women golfers (Christiana and Kandy) over a six‐year period. Through a narrative analysis of structure and form we explored each participant’s stories of living in and withdrawing from professional golf. We suggest Christiana told monological performance‐oriented stories which, while aligning with the culture of elite sport, resulted in an exclusive athletic identity and foreclosure of alternative selves and roles. On withdrawal, Christiana experienced narrative wreckage, identity collapse, mental health difficulties and considerable psychological trauma. In contrast, Kandy told dialogical discovery‐oriented stories which, while being in tension with the dominant performance narrative, created and sustained a multidimensional identity and self. Her stories and identity remained intact, authentic and continuous on withdrawal from tournament golf and she experienced few psychological problems

Singular potentials and annihilation

We discuss the regularization of attractive singular potentials $-\alpha _{s}/r^{s}$, $s\geq 2$ by infinitesimal imaginary addition to interaction constant $\alpha_{s}=\alpha_{s}\pm i0$. Such a procedure enables unique definition of scattering observables and is equal to an absorption (creation) of particles in the origin. It is shown, that suggested regularization is an analytical continuation of the scattering amplitudes of repulsive singular potential in interaction constant $\alpha_{s}$. The nearthreshold properties of regularized in a mentioned way singular potential are examined. We obtain expressions for the scattering lengths, which turn to be complex even for infinitesimal imaginary part of interaction constant. The problem of perturbation of nearthreshold states of regular potential by a singular one is treated, the expressions for level shifts and widths are obtained. We show, that the physical sense of suggested regularization is that the scattering observables are insensitive to any details of the short range modification of singular potential, if there exists sufficiently strong inelastic short range interaction. In this case the scattering observables are determined by solutions of Schrodinger equation with regularized potential $-(\alpha_{s}\pm i0)/r^{s}$. We point out that the developed formalism can be applied for the description of systems with short range annihilation, in particular low energy nucleon-antinucleon scattering.Comment: 10 page

Long-term treatment with the dopamine agonist quinagolide of patients with clinically non-functioning pituitary adenoma

OBJECTIVE: This study was performed to evaluate the effect of prolonged treatment with the dopamine agonist quinagolide on serum gonadotropin and alpha-subunit concentrations and tumor volume in patients with clinically non-functioning pituitary adenomas (CNPA). DESIGN: Ten patients with CNPA were treated with quinagolide (0.3 mg daily). The median duration of treatment was 57 months (range 36-93 months). Blood samples for measurement of serum gonadotropin and alpha-subunit concentrations were drawn before treatment, after 5 days, and at each outpatient visit. Computerized tomography or magnetic resonance imaging of the pituitary region and Goldmann perimetry were done before and at regular intervals during treatment. RESULTS: A significant decrease of serum FSH, LH or alpha-subunit concentrations was found in nine patients. The levels remained low during the entire treatment period. In two out of three patients with pre-existing visual field defects a slight improvement was shown during the first months of treatment, but eventually deterioration occurred in all three patients. A fourth patient developed unilateral ophthalmoplegia dur

Singular Potentials and Limit Cycles

We show that a central $1/r^n$ singular potential (with $n\geq 2$) is renormalized by a one-parameter square-well counterterm; low-energy observables are made independent of the square-well width by adjusting the square-well strength. We find a closed form expression for the renormalization-group evolution of the square-well counterterm.Comment: 15 pages LaTex, 5 eps figures, error in figures and text correcte