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Validating a laser for measuring supine and standing heights against current measures in adults

Description
The stadiometer is the gold standard human height measure, but recent studies have begun to question whether laser technology is a better tool to measure height. The purpose of this study was to investigate if the laser device has inter-rater reliability, how the laser-device measures supine height in comparison to…

The stadiometer is the gold standard human height measure, but recent studies have begun to question whether laser technology is a better tool to measure height. The purpose of this study was to investigate if the laser device has inter-rater reliability, how the laser-device measures supine height in comparison to standard methods, and if the laser device will be consistent in measuring human height shorter, as seen in previous studies. Two investigators measured a total of 80 adults independently. Measurements included knee height, arm span, demi span, supine height by laser, standing height by laser and standing height by stadiometer. There was a strong inter-rater reliability for the laser height measurement: excluding one outlier r=0.998. Supine height measures done with a laser were strongly correlated with arm span, but mean values were closest between supine height and knee height (171.3cm and 171.2cm). The laser measured standing height 0.5cm shorter, on average, than the stadiometer. It is concluded that the laser device is a reliable, validated tool to measure human height, standing or supine.
ContributorsGarcia-Turner, Vanessa (Author) / Johnston, Carol S (Thesis advisor) / Mayol-Kreiser, Sandra N (Committee member) / Bruening, Meg (Committee member) / Arizona State University (Publisher)
Created2016
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Synthesis and Characterization of Laser Plasma that Produces Pseudocarbyne Using Laser Pulses

Description
Carbon allotropes are the basis for many exciting advancements in technology. While sp² and sp³ hybridizations are well understood, the sp¹ hybridized carbon has been elusive. However, with recent advances made using a pulsed laser ablation in liquid technique, sp¹ hybridized carbon allotropes have been created. The fabricated carbon chain…

Carbon allotropes are the basis for many exciting advancements in technology. While sp² and sp³ hybridizations are well understood, the sp¹ hybridized carbon has been elusive. However, with recent advances made using a pulsed laser ablation in liquid technique, sp¹ hybridized carbon allotropes have been created. The fabricated carbon chain is composed of sp¹ and sp³ hybridized bonds, but it also incorporates nanoparticles such as gold or possibly silver to stabilize the chain. The polyyne generated in this process is called pseudocarbyne due to its striking resemblance to the theoretical carbyne. The formation of these carbon chains is yet to be fully understood, but significant progress has been made in determining the temperature of the plasma in which the pseudocarbyne is formed. When a 532 nm pulsed laser with a pulsed energy of 250 mJ and pulse length of 10ns is used to ablate a gold target, a peak temperature of 13400 K is measured. When measured using Laser-Induced Breakdown spectroscopy (LIBS) the average temperature of the neutral carbon plasma over one second was 4590±172 K. This temperature strongly suggests that the current theoretical model used to describe the temperature at which pseudocarbyne generates is accurate.
ContributorsWala, Ryland Gerald (Co-author) / Wala, Ryland (Co-author) / Sayres, Scott (Thesis director) / Steimle, Timothy (Committee member) / Drucker, Jeffery (Committee member) / Historical, Philosophical & Religious Studies (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Department of Physics (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05