Browsing by Author "Dr. Lei Qian, Committee Member"

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    Adapting Lean Manufacturing Principles to the Textile Industry
    (2008-04-25) Goforth, Kelly Ann; Dr. George Hodge, Committee Co-Chair; Dr. Jeffrey A. Joines, Committee Co-Chair; Dr. Kristin Thoney, Committee Member; Dr. Lei Qian, Committee Member
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    De-bottlenecking the Electrospinning Process Using Superparamagnetic Particles
    (2006-07-23) Satcher, Melinda Renee; Dr. Lei Qian, Committee Member; Dr. William Oxenham, Committee Member; Dr. Saad Khan, Committee Co-Chair; Dr. Juan Hinestroza, Committee Co-Chair
    Nanocomposite polyethylene oxide (PEO) fibers containing magnetic domains were produced using parallel plate electrospinning. The fibers were spun from solutions dosed with nanoparticles of magnetite (Fe3O4) in 2wt% PEO in water. Solution parameters like viscosity, conductivity, and surface tension were measured and correlated to final fiber diameter. Increased amounts of magnetic nanoparticles produced higher conductivity, higher viscosity, and lower surface tension solutions. Transmission electron microscopy and energy dispersive spectroscopy were used to analyze the diameters of the nanofibers as well as the distribution of the magnetic nanoparticles inside the PEO matrix. A SQUID magnetometer was applied to determine the AC and DC magnetic susceptibility of the fibers. The resultant nanofibers had diameters as low as 100 nm and exhibited unique AC susceptibility patterns and magnetic responses making them excellent for anti-counterfeiting applications.
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    Electrostatic Self-assembled Nanolayers on Textile Fibers
    (2006-04-19) Hyde, Gary Kevin; Dr. Lei Qian, Committee Member; Dr. Juan Hinestroza, Committee Chair; Dr. William Oxenham, Committee Member; Dr. Peter Hauser, Committee Member
    This project reports the deposition of nanolayers of poly(sodium 4-styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) over cotton fibers using the electrostatic self-assembly method (ESA). While glass, silicon wafers, gold coated particles, quartz and mica have dominated the choice of substrates for ESA, the use of textile fibers has been rarely considered. Cotton, in particular, offers a unique challenge to the deposition of nanolayers because of its unique cross section as well as the chemical heterogeneity of its surface. The deposition of the nanolayers involved the preparation of cotton substrates via immersion in 2,3-epoxypropyltrimethylammonium chloride solutions to produce cotton with a high density of cationic groups. The cationic cotton was processed further by repeated sequential dipping into aqueous solutions of PSS and PAH with rinsing between each deposition step. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM) were used to verify the presence of deposited nanolayers. This research work demonstrates the possibility of using the ESA method to tailor the surface of textile fibers at the molecular level by depositing nanolayers of biocidal, charged nanoparticles, non-reactive dyes, and polyelectrolytes in a controlled manner. Preliminary results indicate that the thickness and sequence of the nanolayers can be controlled to tailor and enhance the selectivity, diffusivity, and permeability of the textile fibers while maintaining their comfort and physical properties.
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    Plant Floor Scheduling Systems in a Lean Environment
    (2008-04-26) Wagoner, April Gail; Dr. George Hodge, Committee Co-Chair; Dr. Lei Qian, Committee Member; Dr. Jeffrey A. Joines, Committee Member; Dr. Kristin Thoney, Committee Co-Chair
    The objective of this study was to determine how companies in the US textile industry are using lean manufacturing practices in their planning and scheduling systems. The study uses primary and secondary data sources to explore the utilization of lean techniques in manual or automated planning and scheduling systems. In addition to a literature review, ten open ended in-person interviews with textile industry executives and three in-depth case studies were used to gather data. The case studies were conducted to further explore whether or not the use of lean principles can be applied to planning and scheduling systems in specific textile operations. Many textile companies are interested in implementing lean scheduling systems for the plant floor but have not quite come to that point in their lean transformation. This study will provide examples, barriers and suggested solutions to the barriers for those companies who are on the path forward to implementation of lean planning and scheduling systems. Textile companies who are already using lean practices in their planning and scheduling systems are seeing improvements through reduced finished goods and work-in-process inventory, as well as less time and effort required by the production planners and schedulers to schedule the plant floor. A directory of planning and scheduling software that can handle lean concepts and is applicable to the textile industry was compiled as part of this research.