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Fiber elongation (ability to stretch before breaking) is one of the key components in determining overall yarn quality. Elongation in U.S. upland cotton (G. hirsutum L.) has remained largely neglected due to: absence of monetary incentives for growers to produce high elongation cotton; lack of research interests among breeders; and absence of a reliable fiber testing system for elongation. This study was conducted to determine the genetics of cotton fiber elongation via a diallel and generation means analysis (GMA). Findings from this study should lay the foundation for future breeding work in cotton fiber elongation. Of the seven distinctive upland parents used for the diallel study, general combining ability was far more prominent than specific combing ability for fiber elongation. Cultivar PSC 355 and Dever experimental line were the two parents identified as good combiners for fiber elongation in this study. The slight negative correlation between fiber elongation and strength remained true. Highly significant negative correlation was observed between fiber upper half mean length and elongation. Both Stelometer and HVI elongation measurements correlated well with values of 0.85 and 0.82 in 2010 and 2011, respectively. For the six families used in the GMA analysis, additive genetic control was prevalent over dominance effect. Based on the scaling test, no significant epistatic interaction was detected for fiber elongation. As expected, additive variance constituted a much larger portion of total genetic variation in fiber elongation than the dominance variance. On average, larger numbers of effective factor were identified in fiber elongation than all other fiber traits tested, suggesting that parents used in the GMA study are carrying different genetic materials/ loci for fiber elongation. Considerable gains in fiber elongation may be achieved by selectively crossing these materials in a pure-line breeding scheme while holding other important fiber traits constant.

Transmission impairments degrade the quality of optical signals, ultimately limiting the achievable transmission distance. Optical 3R regenerators provide an effective means of coping with transmission impairments by restoring the quality of optical signals through reamplification, reshaping, and retiming (3Rs), thereby enabling reliable transmission over long distances. Beyond the 3Rs, however, regenerators must also be able to operate within the practical constraints of the network. The specific network of interest in this thesis is referred to as an agile all-photonic network (AAPN). In AAPNs, traffic consists of optical packets that are routed through the core of the network without undergoing optical-to-electrical conversion for signal processing (e.g., 3R regeneration). As a result, 3R regeneration must be performed all-optically, otherwise known as all-optical 3R regeneration (AO-3R). Although a variety of AO-3R techniques have been demonstrated, none have been specifically designed to operate within the practical constraints of AAPNs. In this thesis, a 10 Gb/s all-optical 3R regeneration (AO-3R) technique is proposed, specifically designed to operate within the practical constraints of AAPNs. The technique performs AO-3R in a novel 2-stage design. In the first stage, all-optical retiming is achieved using a self-pulsating distributed feedback laser (SP-DFBL) for all-optical clock recovery and cross-phase modulation (XPM) in highly nonlinear fiber (HNLF) with offset spectral slicing for the retiming. In the second stage, all-optical reshaping (and reamplification) is achieved using self-phase modulation (SPM) in HNLF with offset spectral slicing. Experimental assessment of the AO-3R system performance yields excellent results. In particular, AO-3R is shown to improve the performance of input signals degraded by transmission impairments, such as amplified spontaneous emission (ASE) noise, while providing low sensitivity to input signal properties, such as the state-of-polarization. Furthermore, AO-3R is shown to successfully achieve its ultimate goal for AAPNs – the regeneration of optical packets. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2007-08-09 16:31:25.462

Cavity ring-down spectroscopy (CRDS) is an absorption spectroscopic technique. In CRDS the concentration of an analyte is determined by measuring the reduction in finesse of an optical cavity made from two highly reflective (R>99.9%) mirrors once a sample is introduced. Optical loss is traditionally determined from the exponential intensity decay of a short laser pulse that was injected into the cavity. This decay is the longest for an empty, high finesse cavity and is reduced when the sample absorbs or scatters light. In this project, the optical cavity is made from fiber optic waveguides and the light source is a continuous wave (cw) diode laser. It is used to detect analytes such as acetylene, ammonia and other amines through their overtone absorption in the telecom region at 1500 nm. The experiment is done by increasing the ratio of desired loss (extinction caused by the sample), to undesirable loss (from the waveguide or solvents) through amplification of the ringdown signal using an erbium doped fiber amplifier (EDFA). The EDFA is inserted into a fiber-optic loop and its gain is increased above the lasing threshold. The gain of the, now lasing, fiber loop is "clamped" to a high and constant value, thereby removing unwanted gain fluctuations, and all losses in the loop are compensated for. If one now inserts a laser light pulse at the lasing wavelength of the loop it would circulate through the loop indefinitely, whereas a light pulse at a wavelength that is being absorbed by an analyte would experience a decrease with time at a rate that depends only on the magnitude of the sample absorption. By enclosing the sample gap with a gas cell both acetylene and ammonia have been detected down to ~25 ppm and ~5.9 Torr respectively. Subsequently, a 1% solution of aminotoluene was detected in an interrogation volume of 5.65 pL by having inserted a fiber with a hole drilled in it as the sample gap. At present, the drilled fiber has been replaced with photonic crystal fiber such that small volumes of gases may be detected with a longer effective path length. / Thesis (Master, Chemistry) -- Queen's University, 2011-09-23 18:27:47.65

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By "intelligently" locating a sensor with respect to its environment it is possible to minimize the number of sensing operations required to perform many tasks. This is particularly important for sensing media which provide only "sparse" data, such as tactile sensors and sonar. In this thesis, a system is described which uses the principles of statistical decision theory to determine the optimal sensing locations to perform recognition and localization operations. The system uses a Bayesian approach to utilize any prior object information (including object models or previously-acquired sensory data) in choosing the sensing locations.