Thesis (M.S.)--University of Iowa, 2008. / Thesis supervisor: Bryant F. McAllister. Includes bibliographical references (leaves 68-75).

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 29, 2010). Thesis advisor: Dr. Reginald B. Cocroft. Vita. Includes bibliographical references.

Laser Measurement Systems (LMS) are used in autonomous agricultural vehicles for guidance and obstacle detection purposes. In the particular case of agricultural vehicles, the efficiency of LMS measurements is affected by mechanical vibrations induced by the operation of these machines on uneven terrains. The objective of this study was to evaluate the effectiveness of a mounting system capable of reducing the transmission of mechanical vibrations to an LMS sensor installed on an agricultural tractor for the purpose of improving the detection accuracy of obstacles during field operation. A stabilization system (SS) was designed for a SICK LMS 291-S14 scanner. The LMS sensor and the SS were installed on an agricultural tractor to scan four objects positioned at known locations in the field. An experimental analysis was carried out to evaluate the detection accuracy of the LMS sensor under different operating conditions: with and without SS; with and without support bars (S); and for different types of terrains (in terms of roughness) and field operating speed. The detection accuracy of the LMS sensor was assessed by determining the difference between the known location of the four objects and their corresponding estimated location from the LMS measurements. The increase of tractor speed had a negative effect on the accuracy of the LMS sensor with an increase in the positioning error of up to 75%. However, it was not possible to establish a clear relationship between terrain roughness and the accuracy of the LMS sensor. The addition of the S systems positively affected the accuracy of the LMS sensor and resulted in a 41% decrease of the average positioning error from 0.340 to 0.201 m. Finally, the used of the SS mounting system decreased the average positioning error by 57% from 0.382 to 0.161 m. These experimental results confirmed the effectiveness of the joint use of the SS and S mounting systems in improving the accuracy of the LMS sensor mounted on an agricultural tractor through a reduction in transmitted vibrations.

Laser Measurement Systems (LMS) are used in autonomous agricultural vehicles for guidance and obstacle detection purposes. In the particular case of agricultural vehicles, the efficiency of LMS measurements is affected by mechanical vibrations induced by the operation of these machines on uneven terrains. The objective of this study was to evaluate the effectiveness of a mounting system capable of reducing the transmission of mechanical vibrations to an LMS sensor installed on an agricultural tractor for the purpose of improving the detection accuracy of obstacles during field operation. A stabilization system (SS) was designed for a SICK LMS 291-S14 scanner. The LMS sensor and the SS were installed on an agricultural tractor to scan four objects positioned at known locations in the field. An experimental analysis was carried out to evaluate the detection accuracy of the LMS sensor under different operating conditions: with and without SS; with and without support bars (S); and for different types of terrains (in terms of roughness) and field operating speed. The detection accuracy of the LMS sensor was assessed by determining the difference between the known location of the four objects and their corresponding estimated location from the LMS measurements. The increase of tractor speed had a negative effect on the accuracy of the LMS sensor with an increase in the positioning error of up to 75%. However, it was not possible to establish a clear relationship between terrain roughness and the accuracy of the LMS sensor. The addition of the S systems positively affected the accuracy of the LMS sensor and resulted in a 41% decrease of the average positioning error from 0.340 to 0.201 m. Finally, the used of the SS mounting system decreased the average positioning error by 57% from 0.382 to 0.161 m. These experimental results confirmed the effectiveness of the joint use of the SS and S mounting systems in improving the accuracy of the LMS sensor mounted on an agricultural tractor through a reduction in transmitted vibrations.

Title from title page of PDF (University of Missouri--St. Louis, viewed March 23, 2010). Includes bibliographical references.

Thesis (M.S.)--The University of North Carolina at Greensboro, 2009. / Directed by Malcolm Schug; submitted to the Dept. of Biology. Title from PDF t.p. (viewed May 11, 2010). Includes bibliographical references (p. 46-49).

Laser Measurement Systems (LMS) are used in autonomous agricultural vehicles for guidance and obstacle detection purposes. In the particular case of agricultural vehicles, the efficiency of LMS measurements is affected by mechanical vibrations induced by the operation of these machines on uneven terrains. The objective of this study was to evaluate the effectiveness of a mounting system capable of reducing the transmission of mechanical vibrations to an LMS sensor installed on an agricultural tractor for the purpose of improving the detection accuracy of obstacles during field operation. A stabilization system (SS) was designed for a SICK LMS 291-S14 scanner. The LMS sensor and the SS were installed on an agricultural tractor to scan four objects positioned at known locations in the field. An experimental analysis was carried out to evaluate the detection accuracy of the LMS sensor under different operating conditions: with and without SS; with and without support bars (S); and for different types of terrains (in terms of roughness) and field operating speed. The detection accuracy of the LMS sensor was assessed by determining the difference between the known location of the four objects and their corresponding estimated location from the LMS measurements. The increase of tractor speed had a negative effect on the accuracy of the LMS sensor with an increase in the positioning error of up to 75%. However, it was not possible to establish a clear relationship between terrain roughness and the accuracy of the LMS sensor. The addition of the S systems positively affected the accuracy of the LMS sensor and resulted in a 41% decrease of the average positioning error from 0.340 to 0.201 m. Finally, the used of the SS mounting system decreased the average positioning error by 57% from 0.382 to 0.161 m. These experimental results confirmed the effectiveness of the joint use of the SS and S mounting systems in improving the accuracy of the LMS sensor mounted on an agricultural tractor through a reduction in transmitted vibrations.

Thesis (M.S.)--Montana State University, 2004. / Title from PDF title page (viewed Feb. 11, 2005). Includes bibliographical references (p. 54-60).

Thesis (doctoral)--Ludwig-Maximilians-Universität München, 2003. / Title from PDF t.p. (viewed on May 13, 2006). Vita. Includes bibliographical references (p. 128-137).

In a program aimed at the identification of compounds responsible for the immunosuppressive and antifertility activities of the perennial twining vine, Tripterygium wilfordii. 5 new and 13 known compounds were isolated from the TRP-4a tissue culture cell line developed from Tripterygium wilfordii. The structures of the new compounds were determined by a combination of spectral analysis, chemical correlation and single crystal X-ray diffraction analysis. 22β-Hydroxy-3-oxoolean-12-en-29-oic acid (137), 22α-hydroxy-3-oxoolean- 12- en-29-oic acid (138) and 3β, 22β-dihydroxyolean-12-en-29-oic acid (139) are new triterpenes possessing an oleanene-type skeleton and were chemically correlated with 3β, 22α-dihydroxyolean-12-en-29-oic acid (51), the structure of which was confirmed by single crystal X-ray diffraction analysis. Oleanolic acid (127), β-sitosterol (128) and polpunonic acid (55), were isolated previously from the TRP-4a cell line in earlier studies in this laboratory. α-Amyrin (145), β-amyrin (146), 3β, 29-dihydroxyolean-12-ene (151) and 3β, llα-dihydroxyolean-12-ene (152) are known triterpenes possessing an oleanene-type skeleton and are isolated for the first time from the TRP-4a cell line. Tingenone (148) and 22β-hydroxytingenone (150) are quinone methide triterpenes, also isolated for the first time from the TRP-4a cell line. Similarly, the novel diterpene, 12-methoxyabieta-8, 11, 13- trien-3α-ol (147) and the novel triterpene, methyl-22β-hydroxy-3, 21-dioxo-D:A-friedo-29-noroleanan-24-oate (149), a member of the friedelane family, are isolated for the first time. A biosynthetic pathway, based on the isolation of 149 and its structural similarity to polpunonic acid (55) and 22β-hydroxytingen6ne (150), is postulated for the quinone methides. The cytotoxic diterpenes, tripdiolide (1) and triptolide (2) and the hydroxy acid, 160, isolated as the methyl ester, 124, have been previously reported from this laboratory. Tripdiolide (1) and triptolide (2) have been shown to possess strong antifertility and immunosuppressive activities. In another aspect of our program, biotransformation studies of the synthetic precursors, 19 (4➙3)abeo-abieta-2, 8, 11, 13-tetraen-19-ol (171) and 19-hydroxy-18(4➙3)abeo-abieta-3, 8, 11, 13-tetraen-18-oic acid lactone (91), and the radioactive congeners, 182 and 209, were carried out using the TRP-4a cell line. It was hoped that the data obtained might shed some light on the "late stage" biosynthetic pathway of the diterpene triepoxides, tripdiolide (1) and triptolide (2). Synthesis of 171 was achieved in 5 steps from dehydroabietic acid (80). The radioactive congener, 182, was synthesised using ¹⁴C-paraformaldehyde with 0.4% incorporation of the radiolabel. Biotransformation of 171 using the TRP-4a cell line yielded 19(4➙3)abeo-abieta-2, 8, 11, 13-tetraen-19-al (185) and 19(4➙3)abeo-abieta-2, 8, 11, 13-tetraen-19-oic acid (186) for spectral identification. Biotransformation of 182 yielded the aldehyde, 183 (33.2%) and the acid, 184 (51.9%), the radioactive congeners of 185 and 186 respectively. Synthesis of 91 was achieved in 4 steps from dehydroabietic acid (80). The radioactive congener, 209, was synthesised using ¹⁴C-methyl iodide via ¹⁴C-dimethylsulphonium methylide, with 0.6% incorporation of the radiolabel. Biotransformation of 91 using TRP-4a tissue cultures yielded 19-hydroxy-7-oxo-18(4➙3)abeo-abieta-3, 8, 11, 13-tetraen-18-oic acid lactone (214), 2β, 19-dihydroxy-7-oxo-18(4➙3)abeo-abieta-3, 8, 11, 13-tetraen-18-oic acid lactone (215), 7β, 19-dihydroxy-18(4➙3)abeo-abieta-3, 8, 11, 13-tetraen-18-oic acid lactone (216) and 2β 19-dihydroxy-18(4➙3)abeo-abieta-3, 8, 11, 13-tetraen-18-oic acid lactone (96), for spectral identification. Biotransformation of 209 yielded the ketone, 210 (56.7%), the hydroxy ketone, 211 (5.9%), the benzylic alcohol, 212 (9.6%) and the C2 alcohol, 213 (6.8%), the radioactive congeners of 214,215,216 and 96 respectively. A biosynthetic pathway to the diterpene triepoxides is postulated based on the oxygenated biotransformation products. [formulas omitted] / Science, Faculty of / Chemistry, Department of / Graduate