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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Wheat fiber from a residue to a reinforcing material

Albahttiti, Mohammed T. January 1900 (has links)
Master of Science / Department of Civil Engineering / Hayder A. Rasheed / Throughout history natural fiber was used as one of the main building materials all over the world. Because the use of such materials has decreased in the last century, not much research has been conducted to investigate their performance as a reinforcing material in cement and concrete. In order to investigate one of the most common natural fibers, wheat fibers, as a reinforcing material, 156 mortar specimens and 99 concrete specimens were tested. The specimens were tested in either uniaxial compression or flexure. The uniaxial compression test included 2 in (50.8 mm) mortar cubes and 4x8 in (101.6 x 203.2 mm) concrete cylinders. As for the flexure test, they were either 40x40x160 mm cementitious matrix prisms or 6x6x21 in (152.4x152.4x533.4 mm) concrete prisms. Several wheat fibers percentages were studied and compared with polypropylene fiber as a benchmarking alternative. The average increase in the uniaxial compression strength for cementitious matrix cubes reinforced with 0.5% long wheat fiber exceeded that of their counterparts reinforced with polypropylene fiber by 15%. Whereas for concrete cylinders reinforced with 0.75% long wheat fiber, their strength exceeded that of their counterparts reinforced with polypropylene fiber by 5% and that of the control by 7%. The flexural strength of cementitious matrix prisms reinforced with 0.75% long wheat fiber exceeded that of their counterparts reinforced with polypropylene fiber by 27%. Meanwhile, concrete prisms reinforced with both long wheat fiber and polypropylene fiber showed deterioration in strength of up to 17%. Finally, ABAQUS models were developed for concrete cylinders and prisms to simulate the effect of inclusion of the wheat fibers.
32

PC-SWMM modeling of policy changes on suburban watersheds in Johnson County, Kansas

Brady, Grant January 1900 (has links)
Master of Science / Department of Biological & Agricultural Engineering / Stacy Hutchinson / Urban areas have traditionally been managed as separate entities from the natural environment. Recently, urban planners have been interested in reconnecting these areas back to the biosphere to capitalize on ecosystem services restoring damaged hydrologic processes. This study focuses on suburban Johnson County, KS (part of the Greater Kansas City area), which has 62 USEPA 303(d) listed “impaired” or “potentially impaired” waterbodies. Previous studies show that watersheds crisscrossed by multiple politically boundaries see increases in water quantity and decreases in water quality. Using a multi-watershed, multi-city spanning entity like a school district, it is investigated how stormwater best management practices (BMPs) employed over a large entity can help undo the negative effects of watershed political fragmentation. BMP modeling includes simulating grassroots and planning policy change movements across three target watersheds using PC-SWMM watershed model. The grassroots simulation models rain barrels at single family homes and an extended dry detention basin (EDDB) at schools. Planning policy simulation models 10% and 20% reductions in impervious roads and parking lots in accordance to EPA Smart Growth practices. Resulting, it was seen that all three of these BMPs saw the greatest improvements from current conditions at low precipitation events. Ranking from least to most effective across the outlet’s average flow, maximum flow, and total volume and supporting watershed infiltration, surface runoff, and surface storage are as follows: rain barrels + EDDB, 10% reduced, and 20% reduced impervious simulations. All three stormwater BMPs help demonstrate how grassroots movements and planning polices changes can positively impact regional waterbodies in this maturely suburbanized region.

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