Thesis (Ph. D.)--Carnegie-Mellon University, 1983. / Bibliography: p. 147-153.

The enhanced Polar Outflow Probe (ePOP) satellite is to be launched in 2007. One of the 8 instruments it will carry is a Radio Receiver Instrument (RRI) which is a passive radio receiver. The RRI will detect HF (High Frequency band 3 to 30 MHz) radio waves from ground transmitters, one of which is the Saskatoon SuperDARN radar. The modification of an HF radar wave as it propagates through the ionosphere to the satellite is the dominant scientific interest of this thesis. The modification of a radar wave as it propagates through the ionosphere can be used to characterize the ionosphere and reveal a better understanding of magnetoionic radar wave propagation. A ray tracing program has been written to determine characteristics of the wave, including the wave path and the full polarization state, at the satellite receiver. </p> As a confirmation of the ray tracing program abilities, data from a similar transionospheric experiment in 1978, the ISIS II satellite mission, has been analyzed and compared with simulated results. The ISIS II transionospheric experiment received radar signals from a transmitter (9.303 MHz) located in Ottawa, Canada. These signals were analyzed and it was noted that the signal periodically faded in and out both due to differential Faraday rotation effects (due to propagation through an ionized medium and reception on a single dipole antenna) and due to satellite spin rotation at rates up to 13 Hz. Also observed was a splitting of the received signal into Ordinary (O-mode) and Extraordinary (X-mode) components causing a delay between the arrival of the modes at ISIS II of up to 0.8 ms. Simulations have been carried out to model the radar wave propagation from the ground transmitter through the ionized medium of the ionosphere to the spacecraft. The modelled signal shows very similar trends to the observed signal. A linear regression analysis comparing observed to simulated fade rates gave values of slope equal to 1.07 and regression coefficient equal to 0.934. The regression analysis of mode delay gave values of slope equal to 1.14 and regression coefficient equal to 0.930. </p>Ray path modelling has also been simulated for the RRI experiment on ePOP. These simulations have been carried out for various ionospheric and satellite pass configurations. The expected fade rates, mode delays, and latitudinal range of received signal was determined from the simulated data in each case. The dependence of these characteristics on the various pass configurations are presented and discussed.

The enhanced Polar Outflow Probe (ePOP) satellite is to be launched in 2007. One of the 8 instruments it will carry is a Radio Receiver Instrument (RRI) which is a passive radio receiver. The RRI will detect HF (High Frequency band 3 to 30 MHz) radio waves from ground transmitters, one of which is the Saskatoon SuperDARN radar. The modification of an HF radar wave as it propagates through the ionosphere to the satellite is the dominant scientific interest of this thesis. The modification of a radar wave as it propagates through the ionosphere can be used to characterize the ionosphere and reveal a better understanding of magnetoionic radar wave propagation. A ray tracing program has been written to determine characteristics of the wave, including the wave path and the full polarization state, at the satellite receiver. </p> As a confirmation of the ray tracing program abilities, data from a similar transionospheric experiment in 1978, the ISIS II satellite mission, has been analyzed and compared with simulated results. The ISIS II transionospheric experiment received radar signals from a transmitter (9.303 MHz) located in Ottawa, Canada. These signals were analyzed and it was noted that the signal periodically faded in and out both due to differential Faraday rotation effects (due to propagation through an ionized medium and reception on a single dipole antenna) and due to satellite spin rotation at rates up to 13 Hz. Also observed was a splitting of the received signal into Ordinary (O-mode) and Extraordinary (X-mode) components causing a delay between the arrival of the modes at ISIS II of up to 0.8 ms. Simulations have been carried out to model the radar wave propagation from the ground transmitter through the ionized medium of the ionosphere to the spacecraft. The modelled signal shows very similar trends to the observed signal. A linear regression analysis comparing observed to simulated fade rates gave values of slope equal to 1.07 and regression coefficient equal to 0.934. The regression analysis of mode delay gave values of slope equal to 1.14 and regression coefficient equal to 0.930. </p>Ray path modelling has also been simulated for the RRI experiment on ePOP. These simulations have been carried out for various ionospheric and satellite pass configurations. The expected fade rates, mode delays, and latitudinal range of received signal was determined from the simulated data in each case. The dependence of these characteristics on the various pass configurations are presented and discussed.

Several terpenoids isolated from a Formosan gorgonian coral Isis hippuris have shown significant cytotoxic activity against various cancer cell lines. In our studies, the EtOAc and n-Hexane extracts showed potent cytotoxic response toward P-388, A549 and HT-29 cancer cell lines. In order to search other active components, we have studied the chemical constituents of I. hippuris from a Green Island specimen. Thus, the investigation on the chemical content of this extract was carried out. After our hard working, we haved isolated eleven new steroids (1- 11) , A-nor-2-carboxy-22-epi-hippurin-1 (1)¡B2a-acetoxy-3a-hydroxy- 11b-hydroxy-24-methyl-22,25-epoxy-5a-furostan-18,20b-lactone (2)¡B2a,3a-dihydroxy-11b-hydroxy-24-methyl-22,25-epoxy-5a-furostan-18,20b-lactone (3)¡B2a-hydroxy-3a-acetoxy-11b-hydroxy-24-methyl-22, 25-epoxy-5a-furostan-18,20b-lactone (4)¡B2a-hydroxy-3a-acetoxy-24- methyl-11b,18;18,20b;22,25-triepoxy-5a-furostane (5)¡B2a-acetoxy- 3a-hydroxy-24-methyl-11b,18;18,20b;22,25-triepoxy-5a-furostane (6)¡Bhippuristerone K (7)¡Bhippuristerone L (8)¡B hippuristerol F (9)¡B1a, 3b,5b,11a-tetrahydroxy gorgostan-6-one (10)¡B22-epi-hippuristan-11-one (11). We also isolated two known compounds, 22-epi- hippuristanol (19)¡B 2-desacetyl-22-epi-hippurin-1 (25). The structures of new compounds (1-11) were elucidated by spectroscopic evidences (IR, MS, 1D NMR, 2D NMR) and the comparison of literature. Among those, the stereochemistry of compound 1, with a new skeleton, were confirmed by single-crystal X-ray diffraction analyses. Unfortunately, because of the poor yield, the cytotoxicity test can not be carry out. But now, we try to get enough by semisynthesis.

Texte remanié de: Dissertation--Fakultät für Orientalistik und Altertumswissenschaft--Universität Heidelberg, 1991. / Notes bibliogr. Index.

Thesis (Ph. D.)--University of Washington, 2001. / Includes bibliographical references (leaves 182-185).

Inaug.-Diss.--Tübingen. / Leben. "Literatur": p. 5-7.

Inaug.-Diss.--Tübingen. / Leben. "Literatur": p. 5-7.

Texte remanié de: Diss.--philosophische Fakultät--Ludwig-Maximilians-Universität München, 1982.

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