This study was conducted to determine the effects of compression on pressure drops in non-metallic flexible duct. Duct sizes of 12”, 14” and 16” diameters were tested at a five different compression ratios (maximum stretch, 4%, 15%, 30% and 45%) following the draw through methodology in ASHRAE Standard 120 -1999 – Methods of Testing to Determine Flow Resistance of Air Ducts and Fittings. With the pressure drop data gathered, equations were developed to approximate the pressure loss at a given air flow rate for a given duct size. The data gathered showed general agreement with previous studies showing an increase in compression ratio leads to an increase in static pressure loss through the duct. It was determined that pressure losses for compression ratios greater than 4% were over four times greater than maximum stretched flexible duct of corresponding duct size. The increased static pressure losses can lead to decreased performance in HVAC systems. The findings of this study add to the existing ASHRAE and industry data for flexible duct with varying compression ratios.

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No description available.

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No description available.

Fabric as a flexible formwork for concrete is an alternative giving builders, engineers, and architects the ability to form virtually any shape. This technique produces a superb concrete surface quality which requires no further touch up or finishing. Woven polyole-fin fabrics are recommended for this application. A permeable woven fabric allows excess water from the concrete mix to bleed through the mold wall, and therefore reduce the water-cement ratio of the concrete mix. Due to the reduction in water-cement ratio, higher compressive strength in fabric formed concrete may be achieved, as also suggested by earlier research. The current research study was conducted to investigate and document the changes in concrete strength and overall quality due to use of commercially available woven polyolefin fabrics. Use of fabric formwork will contribute to decreased construction cost, construction waste, and greenhouse gas emissions. Two sets of tests were conducted as a part of this research study including comparison of compressive strength of fabric formed versus PVC formed concrete cylinders and comparison of be-haviour of the fabric formed reinforced columns versus cardboard formed reinforced concrete columns. Variables in this research were limited to two types of fabric with dif-ferent permeability (Geotex 104F and Geotex 315ST) and two types of concrete; concrete made with conventional Portland cement and no flyash herein called normal concrete (NC) and concrete with 30 percent flyash in its mix design (FAC). The laboratory results revealed that fabric Geotex 315ST is an ideal geotextile for forming concrete. It was also found that the effects of fabric formwork on concrete quality in a large member are limited mostly to the surface zone and the core of the concrete remains the same as a conventionally formed concrete. Even though fabric formed cylinder tests showed an average of 15% increase in compressive strength of the concrete samples, compressive strength of the reinforced columns did not dramatically change when com-pared to the companion cardboard formed control columns. This research confirmed that fabric formwork is structurally safe alternative for forming reinforced concrete columns.

Fabric as a flexible formwork for concrete is an alternative giving builders, engineers, and architects the ability to form virtually any shape. This technique produces a superb concrete surface quality which requires no further touch up or finishing. Woven polyole-fin fabrics are recommended for this application. A permeable woven fabric allows excess water from the concrete mix to bleed through the mold wall, and therefore reduce the water-cement ratio of the concrete mix. Due to the reduction in water-cement ratio, higher compressive strength in fabric formed concrete may be achieved, as also suggested by earlier research. The current research study was conducted to investigate and document the changes in concrete strength and overall quality due to use of commercially available woven polyolefin fabrics. Use of fabric formwork will contribute to decreased construction cost, construction waste, and greenhouse gas emissions. Two sets of tests were conducted as a part of this research study including comparison of compressive strength of fabric formed versus PVC formed concrete cylinders and comparison of be-haviour of the fabric formed reinforced columns versus cardboard formed reinforced concrete columns. Variables in this research were limited to two types of fabric with dif-ferent permeability (Geotex 104F and Geotex 315ST) and two types of concrete; concrete made with conventional Portland cement and no flyash herein called normal concrete (NC) and concrete with 30 percent flyash in its mix design (FAC). The laboratory results revealed that fabric Geotex 315ST is an ideal geotextile for forming concrete. It was also found that the effects of fabric formwork on concrete quality in a large member are limited mostly to the surface zone and the core of the concrete remains the same as a conventionally formed concrete. Even though fabric formed cylinder tests showed an average of 15% increase in compressive strength of the concrete samples, compressive strength of the reinforced columns did not dramatically change when com-pared to the companion cardboard formed control columns. This research confirmed that fabric formwork is structurally safe alternative for forming reinforced concrete columns.

The majority of research on Organic Light-Emitting Diodes (OLEDs) has focused on a top-cathode, conventional bottom-emitting architecture. Yet bottom-cathode, inverted top-emitting OLEDs offer some advantages from an applications point of view. In this thesis, the development of high performance green electroluminescent inverted top-emitting diodes is first presented. The challenges in producing an inverted structure are discussed and the advantages of high efficiency inverted top-emitting OLEDs are provided. Next, the transition to a stacked architecture with separate orange and blue emitting layers is demonstrated, allowing for white emission. The pros and cons of the existing device structure is described, with an eye to future developments and proposed follow-up research.

This thesis compares the results of two of the more popular flexible aircraft modeling formulations, the mean-axes method and the fixed-axes method, for application in real-time motion simulators. First, the time-domain equations of motion for an elastic body using the fixed-axes are derived. Subsequently, the mean-axes equations are derived by making a few assumptions from the fixed-axis equations. The two formulations are then implemented for a scaled-up beam model of a Cessna Citation aircraft, with the deformations represented by the modal expansion of the whole aircraft from their respective constrained and free-free finite element solutions. Time-domain results, consisting of the acceleration, velocity, and attitude of a point on the aircraft body, are obtained in both models at two beam-stiffness configurations using a quasi-steady aerodynamic model for a single maneuver at one flight condition. The two methods produced similar results with the fixed-axes formulation producing slightly more accurate results.

This thesis compares the results of two of the more popular flexible aircraft modeling formulations, the mean-axes method and the fixed-axes method, for application in real-time motion simulators. First, the time-domain equations of motion for an elastic body using the fixed-axes are derived. Subsequently, the mean-axes equations are derived by making a few assumptions from the fixed-axis equations. The two formulations are then implemented for a scaled-up beam model of a Cessna Citation aircraft, with the deformations represented by the modal expansion of the whole aircraft from their respective constrained and free-free finite element solutions. Time-domain results, consisting of the acceleration, velocity, and attitude of a point on the aircraft body, are obtained in both models at two beam-stiffness configurations using a quasi-steady aerodynamic model for a single maneuver at one flight condition. The two methods produced similar results with the fixed-axes formulation producing slightly more accurate results.