Blackberry (Rubus spp.) is a popular fruit due to its delightful taste and notable health benefits. With a growing demand for regional blackberry production, this study aims to provide Virginia blackberry growers with information on the effectiveness of pre-harvest foliar treatments and shade application on yield, white drupelet disorder, post-harvest attributes, and the aroma profile of two blackberry cultivars, Prime-Ark® Traveler and Prime-Ark® Freedom. The field study was repeated in the 2021 and 2022 growing seasons at the Hampton Roads Agricultural Research and Extension Center in Virginia Beach, VA, in a completely randomized design. Grower standard control (GSC), shade cloth with 30% light reduction (SHA), calcium (CAL), and salicylic acid (SAL) foliar applications were randomly assigned to each variety. Fruit yield and physicochemical attributes of the blackberry were collected and analyzed, and aroma-active compounds in blackberries were identified by use of headspace-solid-phase microextraction-gas chromatography-mass spectrometry-olfaction (HS-SPME-GC-MS-O). Shade cloth significantly reduced the white drupelet disorder (WDD) in Prime-Ark® Freedom but it also reduced the total soluble solid content (°Bx) and °Bx/% titratable acidity (a ratio indicates the sweet and sour balance for fruit) for both cultivars. No significant improvement was found in the TSS, TA, firmness and yield of blackberries treated with CAL and SAL. In total, 16 consistent aroma-active compounds were found across treatments for both varieties and growing seasons. Foliar and shade application did not alter the aroma profile of either blackberry cultivar. However, higher volatile contents were found in 2021 than in 2022, possibly due to climate variation. A clear distinction on aroma profiles of the above two cultivars were also observed: PrimeArk® Freedom was higher in compounds possessing "fruity" and "floral" notes, while PrimeArk® Traveler featured more "green" and "fresh" characteristics. Regional berry growers should be more conservative when adopting foliar and shade applications due to potential seasonal variations surpassing the significance of agronomic treatments. / Master of Science in Life Sciences / Blackberry (Rubus spp.) with its inky purple color, juicy bursts of sweet and tart flavor, and various health benefits has become more popular recently. With growing demands for locally produced blackberries with better flavor, this study will provide Virginia blackberry growers with information on the effectiveness of pre-harvest foliar treatments and shade applications on yield, white drupelet disorder, post-harvest attributes, and aroma profile of two blackberry cultivars, Prime-Ark® Traveler and Prime-Ark® Freedom. The field study was repeated for two growing seasons 2021 and 2022 at the Hampton Roads Agricultural Research and Extension Center in Virginia Beach, VA. All blackberry plants received standard fertigation, with plots receiving additional either calcium or salicylic acid foliar spray, or shade cloth (black mesh cloth) application to reduce 30% direct sunlight. Fruit yield and post-harvest attributes such as sugar content, firmness, phenolic content, and aroma of the Virginia-grown blackberries were studied. Shade cloth (light reduction) was effective in mitigating discoloration in Prime-Ark® Freedom, but it also reduced the sugar content and sweet and sour balance for both varieties. Calcium and salicylic acid were not effective in improving the yield and fruit quality of blackberries. Fruit harvested in 2021 had a more intense aroma and taste when compared to the 2022 season, likely due to the excessive heat and drier climate in year 2. The two cultivars have different aroma profiles, with PrimeArk® Freedom being more "fruity" and "floral" and PrimeArk® Traveler featuring more "green" and "fresh" notes. This study suggests that regional berry growers should be more conservative when adopting agronomic practices such as foliar spray and shade applications due to seasonal variations (temperature, rainfall) possibly surpassing the effectiveness of agronomic treatments.

The deterioration of prestressed concrete structures due to corrosion is a costly problem. This problem is accelerated in cold weather climates where de-icing salts are used. These salts accelerate the corrosion of the steel tendons greatly reducing the service life of the structures and leading to constant costly repairs. Recent research has shown composite materials such as Fibre Reinforced Polymers (FRP) to be suitable alternatives to steel, providing similar strength without being susceptible to electrochemical corrosion. Carbon FRP in particular has great promise for prestressed applications, showing resistance to corrosion in environments that might be encountered in concrete and experiencing less relaxation than steel. This thesis outlines the testing and implementation of a post-tensioned system that uses CFRP tendons to replace corroded, unbonded post-tensioned steel tendons. This system was then implemented in a parking garage in downtown Toronto. To the author’s knowledge, this is the first example of an unbonded, post-tensioned tendon replacement using FRP tendons. The system used split wedge anchors designed specifically for CFRP tendons at the University of Waterloo. The dead end was anchored by directly bonding the tendon to the concrete slab. Overall, the system was shown to work and provide a durable solution for unbonded post-tensioning systems. The CFRP tendon was successfully inserted in the opening left by the removal of the corroded tendon and stressed. It was found that the current anchorage configuration experienced large load losses of up to 60 % during the transfer. Changing the orientation of the anchor was found to reduce the load lost to a range of 1 % to 9 %. / Thesis (Master, Civil Engineering) -- Queen's University, 2009-04-09 15:30:59.865

At the present time there is a recognized need for a better means of measuring soil moisture in situ. Soil moisture measurements are required in fundamental studies of soil moisture flow and soil-plant-water relationships as well as in practical studies in irrigation practices. Various phases of engineering also utilize soil moisture data, for example, soil moisture determinations are made during the consturction of earth dams, road cuts and fills, and under airfield runways. The desired method should be quick, reliable, and adaptable over the moisture range from oven dryness to saturation. Reserach in nuclear physics has revealed the neutron scattering phenomena which may be utilized as a means of determining soil moisture. It is known that hydrogen nuclei have a large influence on the scattering of neutrons and that most of the hydrogen nuclei in soils occur primarily in water. Using this information it should be possible to correlate the scattering of neutrons in the soil with moisture content. Measurement of soil water in this would be independent of its physical or chemical state in the soil. This would eliminate variables that are inherent in the present methods, such as temperature, soil texture, and salt concentrations. The obejct of this study is to adapt the neutron scattering phenomena to a method of soil moisture determination in situ. The problem is one of instrumentation and calibration. The emphasis will be toward developing an instrument to be used for soil moisture determination in experimental plots. Other diverse applications will also be considered. The prerequisites of the method require that it be more accurate and precise than the present methods without increasing the time and costs involved.