Browsing by Subject "Cotton fiber"
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Item Machine vision system for quantification of cotton fiber length and maturity(2008-08) Shahriar, Muneem; Sari-Sarraf, Hamed; Hequet, Eric F.; Saed, MohammedCotton is an important cash crop in the United States (third producer, first exporter). There is a constant demand for high quality cotton fibers in the export market, especially for fiber length and maturity. This requires an ever moving research into methodologies that can measure these qualities from cotton fibers accurately and quickly. In a previous study, a fiber length algorithm was developed to measure the length of cotton fibers with good accuracy (+/- 1% of true length) and was validated on 20 cotton samples totaling 10,000 fibers. The objective of this thesis is to develop a machine vision system for the quantification of both fiber length and maturity. To achieve this, an improved image acquisition system is proposed which acquires high-resolution (25,400 dpi) longitudinal scans of complete cotton fibers without breaking the fibers into individual segments or applying any physical stress to straighten them. Software algorithms are implemented on these scans to extract features related to fiber length and maturity. For length measurement, Wang~{!/~}s length algorithm is employed because it is invariant to fiber shapes, intra-fiber crimps and inter-fiber intersections. However, modifications have been made primarily to enhance the computational speed of the algorithm so that length measurements are close to real-time. The modified algorithm has also been validated on the original 20 cotton samples. An indirect method of estimating fiber maturity based on the evaluation of cotton fiber characteristics is also proposed. The maturity algorithm measures changes in fiber width, fiber convolutions, and fiber translucency along the length of a fiber and creates features that are pertinent to study these characteristics in more detail. The proposed algorithm has been applied to a sample of 50 mature and 50 immature cotton fibers. The results indicate that all three fiber haracteristics show statistically significant differences between the two samples. Further analysis has also shown that some features such as thin places per-unit-length and intensity differences are excellent predictors of maturity. The least deterministic characteristic found is changes in fiber width. To conclude, the findings imply that the system is fully capable of measuring fiber length, and capable of quantifying maturity differences between cotton samples.Item Studies on submerged cotton fiber growth : induction and characterization, effects of Congo Red and auxin(2003-12) Feng, Rong; Brown, R. Malcolm (Richard Malcolm), 1939-Induction of growth of submerged cotton (Gossypium hirsutum L.) fibers from cultured ovules has been investigated for the first time. Both exogenous plant hormone levels and the age of the ovules at induction play important roles in induction of submerged cotton fiber growth. The diameter of submerged fibers was about same as that of air-grown fibers but was smaller than that of fibers grown in vivo. Submerged fibers were shorter in the fiber length, stronger in the tensile strength, and they had thicker secondary cell walls and smaller crystallite sizes compared with air-grown fibers and fibers in vivo. Helical secondary cell wall thickenings were exclusively found in submerged fibers. Congo Red is a natural dye that has a high affinity for the biopolymer cellulose. The addition of Congo Red to the culture medium had an influence only on submerged cotton fibers and not on air-grown cotton fibers. When Congo Red was applied in the early primary wall stage, fiber cell elongation was inhibited, but amyloplast production was induced. When Congo Red was applied in late primary wall or early secondary wall stage (about 14-16 DPA), the effects were less severe, but a significant increase in birefringence of secondary cell walls was observed. In both conditions of treatment with Congo Red in the primary wall and the secondary wall stages, a "nodulation" occurred on the wall surface. Neither cellobiohydrolase CBH I or CBH II had affinity for the external wall materials, implying that there was no cellulose present or binding sites for CBH had been occupied by Congo Red. X-ray diffraction data showed that Congo Red decreased the crystallite size of cellulose in submerged cotton fibers. The preliminary investigation with auxin (indole-3-acetic acid) depletion in the culture medium was to study whether or not amyloplasts were produced under this condition. No amyloplasts were observed in submerged fibers grown in the auxindepleted medium, but cellulose microfibrils in the secondary cell wall were greatly disorganized. Possibly, indole-3-acetic acid might play an important role in regulating the arrays of microtubules, which, in turn, may help to organize the patterns of cellulose deposition.