Doctor of Philosophy / Department of Horticulture, Forestry, and Recreation Resources / Rhonda R. Janke / The goal of this study is to clarify the influence of organic fertilizer sources on vegetable crop yield under different production systems. This research hypothesized that organic soil amendments will produce healthy and vigorous plants with similar or higher yields while improving soil organic matter levels compared to conventional amendments. Applying organic fertilizer sources can be cost-prohibitive; moreover, synchronizing timing of crop nitrogen demand with soil plant available nitrogen is essential to maximizing yield and reducing nitrogen pollution to the environment. The objectives of this study are to evaluate yield in relation to soil fertility status at different fertility rates for organic and conventional management in field and high tunnel production systems, to measure plant nutrient status in crop petioles and compare it to available mineral N levels in soil at different growing stages, and to determine the effect of nitrogen availability of organic compared to conventional fertilization on plant available nitrogen and crop yield under both systems. A latin square experimental design was conducted from 2008 to 2010 at Kansas State University Research Center in Olathe KS to evaluate an organically managed vegetable rotation of tomato (Solanum lycopersicum L. ‘Bush Celebrity’) and pac choi (Brassica rapa L. ‘Mei Qing’) under three fertility rates; control, low (composted poultry manure), and high (composted poultry manure and fish hydrolyzate) in contrast with conventionally managed soils under two production systems (field and high tunnel). The effect of these four contrasting systems was measured on plant and soil nutrient status. All plots had cover crops of rye during the winter and buckwheat in the summer between pac choi crops. Soil nitrate-N (NO₃-N) and ammonium-N (NH₄-N) were measured, as well as petiole sap nitrate (NO₃⁻). In tomato, additional soluble fertilizers had no direct effect on yield in both field and high tunnel. Compost application had a positive effect on organic matter. In pac choi, additional liquid fertilizer helped organic field plots obtain maximum yield. Soil mineral nitrogen were affected by production system and fertility source, but statistical significance varied by crop and stage. Petiole sap reflected treatment regimens but not necessarily soil N status at each plant stage. The study also addressed long term management practices on organic and conventional available nitrogen. An incubation study on the soil at the conclusion of the field experiment explored the relationship between N mineralization from potentially mineralizable nitrogen (PMN) compared to Illinois Soil Nitrogen Test (ISNT) in control and pre-plant application fertility treatment for both field and high tunnel systems. The results indicated that ISNT concentration values for all soils were below the proposed value for corn crop suggested by (Khan, 2001). ISNT correlated with PMN with the stronger correlation being in field plots. ISNT also correlated with OM in field. Fertility rate showed a significant effect on total carbon and total nitrogen in organic systems of both field and high tunnel plots. This study supports composted poultry manure to improve the fertility status of the soil and to obtain a yield equal to that of conventionally managed soil.

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Physics / Master / Master of Philosophy

<p>The 3-d visualisation of a section of the Tunberget tunnel and important fracture zones was accomplished by combination of the topographic surface, measurements at the surface of fracture planes together with surfaces of dolerite dykes, results from magnetic modeling of dolerite dykes and tunnel mapping data.</p><p>The topographic surface was represented as elevation contours with 1 m equidistance. The fracture and dolerite surfaces were measured geodetically in the field from a net of 20 total station locations. Each surface was measured at 3 points to determine its strike and dip. Totally 44 strike and dip estimates were obtained. The extent at depth of the dolerite dykes was also estimated based on magnetic measurements along 3 profiles. The location of the dykes was also known from geological tunnel mapping.</p><p>ArcGIS and RockWorks have been used to process the data and to generate a 3-d visualization of the geometrical relation between targeted geological structures, the dolerite dykes and the tunnel. The area is of interest to be studied in more detail as the fracture zones and the parallel dolerite dykes connect the tunnel with a large wetland complex.</p> / QC 20100707

Research suggests that, in individuals with carpal tunnel syndrome (CTS), low plasma pyridoxal 5'-phosphate (PLP) concentrations are related to an increased incidence and severity of symptoms associated with CTS. This study was designed to determine the relationship between plasma and red blood cell PLP concentrations and the severity and incidence of CTS symptoms. Thirty people with CTS were selected for a 9 month exercise study. Subjects were divided into either vitamin users or non-vitamin users based on supplement use data gathered at the beginning of the study. Blood was drawn at 1, 6 and 9 months. CTS symptoms questionnaires and health questionnaires were also administered at these intervals. The symptoms questionnaires were used to gather data on the frequency and nature of hand and wrist symptoms. Health questionnaires focused on vitamin supplement usage including frequency, amount and length of use. Mean plasma PLP, total plasma vitamin B6 and erythrocyte PLP concentrations were significantly higher in the sixteen vitamin users when compared to the fourteen non-vitamin users (p<0.001). While there was variation in plasma PLP and total plasma vitamin B6 over time, within each group, there were no significant changes in any of the status measures over the nine month period. Mean erythrocyte PLP concentration, in particular, was stable over time. In vitamin users, the intensity of pain, numbness and tingling was significantly higher when compared to non-vitamin users. In both groups, plasma PLP was negatively correlated with pain. This correlation reached statistical significance in vitamin users at month one and nine (p<0.01), but not at month six; a statistically significant correlation between these two variables was not found in non-vitamin users at any time point. Pain was also negatively and significantly correlated with plasma total vitamin B6 and erythrocyte PLP in vitamin users. No other symptoms were significantly correlated with the status measures. These results indicate that a higher vitamin B6 status may be related to a decrease in the severity of pain experienced by some individuals with CTS. / Graduation date: 1998

L'étude fine des fluctuations de courant dans les petites composantes électroniques est un excellent moyen de tester notre compréhension du transport électronique quantique. Lorsque la fréquence est suffisamment élevée, ce qui est mesuré en laboratoire n’est plus un courant d’électrons mais un champ électromagnétique causé par l’agitation des électrons. Faire un pont entre l’optique en terme de photons et l’électronique quantique est l’objectif dans le laboratoire de Bertrand Reulet. Ce mémoire de maîtrise traite des fluctuations de courant d’une jonction tunnel polarisée en courant et excitée avec une tension alternative dans les micro-ondes. La nouveauté dans ce projet provient du fait que les fluctuations de courant générées par la jonction tunnel ont été mesurées en phase et en quadrature avec l’excitation micro-onde envoyée sur l’échantillon. Il a été démontré qu’il est possible de faire un parallèle entre les fluctuations du courant électrique et l’optique quantique pour arriver à prédire le comportement de ces fluctuations en phase et en quadrature. De plus, la présence d’état comprimé ou «squeezé» sur l’une des quadratures du courant a été mesurée expérimentalement. Les résultats obtenus sont en parfait accord avec la théorie développée.

We present a study on perpendicular magnetic tunnel junctions with W as buffer and capping layers. A tunneling magnetoresistance of 138% and an interfacial magnetic anisotropy of 1.67 erg/cm(2) were obtained in optimally annealed samples. However, after extended annealing at 420 degrees C, junctions with W layers showed extremely small resistance due to interdiffusion of W into the MgO barrier. In contrast, in Ta-based junctions, the MgO barrier remained structurally stable despite disappearance of magnetoresistance after extended annealing due to loss of perpendicular magnetic anisotropy. Compared with conventional tunnel junctions with in-plane magnetic anisotropy, the evolution of tunneling conductance suggests that the relatively low magnetoresistance in perpendicular tunnel junctions is related to the lack of highly polarized Delta(1) conducting channel developed in the initial stage of annealing. Published by AIP Publishing.

A dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Chiropractic at Technikon Natal, 2002. / Carpal Tunnel Syndrome is defined as a median nerve entrapment beneath the flexor retinaculum in the carpal canal such that it produces symptoms in the hand, wrist and upper extremity. A review of related literature suggests that statistics on the incidence of Carpal Tunnel Syndrome in South Africa are unavailable. In the U. s. A, Carpal Tunnel Syndrome occurs in 1% of the population and is the most frequently diagnosed peripheral neuropathy. Several studies investigating the use of conservative care in managing Carpal Tunnel Syndrome have been performed, but none have compared the effect of wrist joint manipulation and ultrasound in the management of Carpal Tunnel Syndrome, The purpose of this study was to investigate the effectiveness of wrist joint manipulation compared to ultrasound in the management of Carpal Tunnel Syndrome. This randomized controlled clinical trial consisted of a study population offorty patients. The patients were randomly allocated to two groups of twenty each. One group received wrist joint manipulation while the other received ultrasound application to the palmar-radial aspect of the wrist. Both groups received four treatments over a two week period. Subjective measures included the Numerical Rating Scale-I 0 1 Questionnaire and the Carpal Tunnel Pain and Disability Form and objective measures consisted of the grip strength reading and goniometer readings for wrist flexion and extension. Both the subjective and objective measures were taken before the first and third visit and at the fifth follow- up consultation which took place during the following week. Inter-group analysis was done using the Mann- Whitney U test. Friedman's T test was used for intra-group analysis. ct was set at the 0.05 level of significance. The results were illustrated by means of tables and bar- charts. The results indicated that for intragroup analysis, a statistically significant difference existed for both groups, warranting the use of a multiple comparison procedure (Dunn' s procedure) to determine at which stage the treatment made a significant difference. For all the measures except the wrist extension reading in the ultrasound group, most improvement occurred between the first and fifth consultations. For inter-group analysis, no significant difference for any of the measures, except the wrist extension readings, was present between the two groups indicating that both wrist joint manipulation and ultrasound were equally effective in treating Carpal Tunnel Syndrome. The improvement in wrist extension, in the wrist joint manipulation group was significantly better than that in the ultrasound group. Although this study was limited by its single researcher design and could not clarify which treatment protocol was more effective, it supports the existing body of evidence in favour of both wrist joint manipulation and therapeutic ultrasound application in the management of Carpal Tunnel Syndrome / M

An inverted airfoil mounted above a flat plate was used to create laminar separation bubbles on a flat plate in water tunnel experiments at low Reynolds numbers. Boundary layer suction ensured that the flow remained attached to the wing. Two-dimensional PIV measurements were used to qualitatively and quantitatively characterize the spanwise bubble variation on an unswept wing and on the same wing featuring a 22 degree sweep. The separation bubbles were recorded at varied span-wise locations in a 31.5 cm wide region of the flow. The limitations of this measurement region were dictated by the focal length of the laser optic used for PIV measurements. The straight wing exhibited approximately uniform time averaged separation positions across the span of the wing. The reattachment locations varied only slightly which was expected due to the transition to turbulent flow before reattachment. A form of bubble "breathing" was observed in the laminar separation bubbles on the straight wing and is believed to have affected the mean reattachment locations for two data points recorded. The shedding frequencies on the straight wing were slightly higher than those obtained from CFD simulations. The swept wing planform showed significantly more variation in the mean separation and reattachment locations with respect to the leading edge of the wing. There is a general trend of the separation locations moving upstream in the direction of the aft leading edge. The reattachment points are shown to move downstream as the separation points move upstream relative to the leading edge and visa versa, displaying an inverse relationship between the two. The bubble lengths were found to be slightly longer on the swept wing compared to the straight wing usually by about 10%. The shedding frequencies on the swept wing were found to be lower than the straight wing. The quality of flow in the water tunnel may have degraded over time, showing signs of increased free stream turbulence. After data collection, it was also discovered that the boundary layer suction on the wing was not constant at all span-wise locations. It is believed that the introduction of wing sweep intensified the effect of insufficient suction on the structure of the bubbles observed. The present results were in agreement with previous research for bubble structure but the dynamic instabilities were found to differ slightly.

An experimental investigation into the form of the notchback wake topology, its temporal behaviour, and how this changes with the underlying geometry has been undertaken to further understanding of this flow regime pertaining to a popular automotive body type. Whilst this work has been performed at model scale on a simplified body a sufficiently complex design of backlight header and trailing pillar have been utilised. Thereby allowing the systematic study of the wake structure of a family of production representative geometries to be undertaken enabling the flow topology across bodies with parameters representative of vehicles produced from the 1960s to the present day to be investigated. Body force measurements showed both drag and rear lift to increase with backlight angle in a manner which was largely expected due to these designs being representative of older production notchback vehicles. Manufacturers knowledge and understanding of how drag changes with this parameter, combined with on going shape optimisation studies, have led to the shallower backlight angles common to modern designs. Detailed flow field measurements were subsequently used to determine the form and temporal behaviour of the flow topologies responsible for this force behaviour. Across the range of geometries tested, the in-notch structures were shown to undergo significant variation, both their time-averaged form and time-variant behaviour changing. Common to all configurations were the presence of a pair of strong trailing vortex structures which flanked the edges of the backlight and bootdeck. However, flow in the centre of the backlight underwent the greatest variation. This region was shown to develop from a largely attached form at shallower backlight angles before developing into an increasingly strong hairpin like structure. As backlight angle increased further the topology ultimately took a highly asymmetric form. With these changes of the flow topology also came changes of the temporal behaviour which revealed vortex shedding, flow structure oscillation and the switching of bi-stable structures as backlight angle increased. It is hoped that in thoroughly understanding the range of notchback flow topologies typically generated by production vehicles that this work will form the vital foundation upon which future investigations looking to reduced drag can be based.