Based on the design concepts of linear induction motors, a non-contacting steel plate conveyance system for steel mill application has been constructed. To reduce the noise and friction from conventional roller conveyance system, the designed system is aimed to simultaneously provide adequate lift, propulsive, and guide forces to the steel plate. At first, the preliminary understandings of the characteristics of lift force have been gained through the simple magnetic circuit analyses, and together with other mechanical concepts develop the laboratory prototype. Then, through three-dimensional finite element analyses and state model developments, the system¡¦s static and quasi-dynamic/dynamic operational characteristics are investigated. Finally, the validity of this system has been verified by experimental measurement. Thus, the analyses and results of the experiment clearly show that the designed non-contacting steel plate conveyance system is certainly feasible.

This study reports the first sediment trap mooring results obtained under the SIBEX program (South China Sea Integrated Biogeochemical Experiments). Two strings of sediment traps were deployed respectively at M1 located to the southwest of Taiwan, and M2 in the northern basin of the South China Sea (SCS). Box cores were also taken at several sites to the south of M2. The main purposes are to measure settling particulate fluxes at various depths for the studies of temporal and spatial variations of the particulate flux and 210Pb activity. The box cores were used to determine the sedimentation rates. These are to enhance our understanding of the characteristics of the particulate distribution and the roles the particulate matter plays in the biogeochemical processes in the SCS. Particulate fluxes measured from different depths at M1 and M2 generally increase with depth. In temporal variation, M1 has higher amplitudes than M2, with highest amplitudes at 948 m where highest flux (2025 mg/m2/d) was observed. The particulate flux at 948 m has higher values than at 248 m, probably due to lateral transport. At M2, the particulate flux at 240 m has higher values with greater amplitudes than at greater depths, i.e. 1240 m, 2240 m and 3240 m, where their particulate fluxes show a synchronous trend with small amplitudes in temporal variation. The time-averaged particulate flux for each trap ranges from 199 to 554 mg/m2/d, consistently higher than previous observations (76~104 mg/m2/d). However, our values are comparable to the mean particulate flux (280 mg/m2/d) estimated from terrigenous inputs. The apparent changes in particulate flux in the SCS over the past ten years warrants further investigations. The temporal variations of Pb-210 show a synchronous trend and a rapid increase with depth as observed at M1 and M2. This rapid increase of Pb-210 with depth reflects effective scavenging by sinking particulates although particulate concentrations are low. The loss on ignition (L.O.I.) at M1 and M2 was inversely correlated with Pb-210, indicating that Pb-210 was expelled from biogenic particulates or organic matter. The particulate fluxes around 240 m at M1 and M2 were generally positively correlated with the L.O.I., suggesting that the high particulate fluxes are probably contributed by biogenic particulates or organic matter. The sedimentation rates as determined from excess Pb-210 profiles range from 9.01~23.13 cm/100yr. These rapid sedimentation rates reflect the effect of mixing and additional sediments accumulated through lateral transport. The surface layers of these cores were subject to perturbation and mixing, based on the penetration depths of the excess Pb-210. The Pb-210 flux estimated from the inventory of excess Pb-210 in the sediments is much greater than that observed from the traps, suggesting that additional Pb-210 has been accumulated via lateral transport and slumping of nearby surface sediments. Based on the mean particulate flux observed, one may roughly estimate the corresponding sedimentation rate of about 10 cm/ka, which is an order of magnitude lower than those determined by the excess Pb-210 method. Because the upper layers of the sediments have been strongly disturbed and mixed with the additional sediments accumulated through lateral transport, the sedimentation rates as determined by the excess Pb-210 method are probably over-estimated by a factor of 10 to 20.

Coastal outwelling of organic carbon from mangrove wetlands contributes to near-shore productivity and influences biogeochemical cycling of elements. I used a flume to measure fluxes of dissolved organic carbon (DOC) between a mangrove forest and adjacent tidal creek along Shark River, Florida. Shark River’s hydrology is influenced by diurnal tides and seasonal rainfall and wind patterns. Samplings were made over multiple tidal cycles in 2003 to include dry, wet, and transitional seasons. Surface water [DOC], temperature, salinity, conductivity and pH were significantly different among all sampling periods. [DOC] was highest during the dry season (May), followed by the wet (October) and transitional (December) seasons. Net DOC export was measured in October and December, inferring the mangrove forest is a source of DOC to the adjacent tidal creek during these periods. This trend may be explained by high rates of rainfall, freshwater inflow and subsequent flushing of wetland soils during this period of the year.

Marine aggregates are an important means of carbon transfers downwards to the deep ocean as well as an important nutritional source for benthic organism communities that are the ultimate recipients of the flux. During these last 10 years, data on size distribution of particulate matter have been collected in different oceanic provinces using an Underwater Video Profiler. The cruise data include simultaneous analyses of particle size distributions as well as additional physical and biological measurements of water properties through the water column. First, size distributions of large aggregates have been compared to simultaneous measurements of particle flux observed in sediment traps. We related sediment trap compositional data to particle size (d) distributions to estimate their vertical fluxes (F) using simple power relationships (F=Ad^b). The spatial resolution of sedimentation processes allowed by the use of in situ particle sizing instruments lead to a more detailed study of the role of physical processes in vertical flux. Second, evolution of the aggregate size distributions with depth was related to overlying primary production and phytoplankton size-distributions on a global scale. A new clustering technique was developed to partition the profiles of aggregate size distributions. Six clusters were isolated. Profiles with a high proportion of large aggregates were found in high-productivity waters while profiles with a high proportion of small aggregates were located in low-productivity waters. The aggregate size and mass flux in the mesopelagic layer were correlated to the nature of primary producers (micro-, nano-, picophytoplankton fractions) and to the amount of integrated chlorophyll a in the euphotic layer using a multiple regression technique on principal components. Finally, a mesoscale area in the North Atlantic Ocean was studied to emphasize the importance of the physical structure of the water column on the horizontal and vertical distribution of particulate matter. The seasonal change in the abundance of aggregates in the upper 1000 m was consistent with changes in the composition and intensity of the particulate flux recorded in sediment traps. In an area dominated by eddies, surface accumulation of aggregates and export down to 1000 m occured at mesoscale distances (<100 km).

A preliminary study shows that Submarine Groundwater Discharge (SGD) exists around Taiwan even though groundwater overdrawing is serious. Only five of the 20 sites studied did not record any SGD signal. Two nearly fresh SGD samples were obtained, providing strong and direct evidence for the existence of SGD in Taiwan. SGD is the submarine seepage of all fluids from coastal sediments into the overlying coastal areas. It has been well documented that SGD may contribute much nutrients to the coasts (Burnett et al.,2001, 2003; Church, 1996; Taniguchi et al., 2002; Zhang and Satake, 2002). Because of its difficulty in measurement, there are few reports on the characteristics of groundwater seepage, such as the flow rate and the water chemistry. In Taiwan, the only report was published in the Japanese journal Geochemistry (Chen et al. , 2005 ). In this study, samples were collected monthly from May, 2004 to June, 2006 at Xiziwan and Caishan in Kaohsiung. A flux chamber was also used in the observation of the SGD seepage rates. Further, samples were collected from 20 different places around Taiwan. The SGD collecting device, the SGD-Flux chamber and the Lee type seepage meter (Zhang et al., 2005) were used in this study, the latter being the first time used to explore the SGD flux in Taiwan. Salinity, dissolved oxygen saturation (%), nutrients (NO3, NO2, PO4, SiO2, NH3), total alkalinity, pH and major ions were analyzed. We averaged all seepage rate data at Xiziwan and Caishan to estimated the SGD seepage rate at about 1.32¡Ó1.57 L/m2/hr. The average concentrations of inorganic nitrogen (NO3+NO2+NH3), PO4 and SiO2 are, respectively, 48.6¡Ó86.3 (n=85), 0.78¡Ó1.26 (n=110) and 55.1¡Ó39.8

Rapport de stage DESS : Réseaux d'information et document électronique : Villeurbanne, ENSSIB : 2002.

Reproduction de : Thèse doctorat : Médecine. Immunologie et biologie parasitaire : Reims : 2005. / Titre provenant de l'écran-titre. Bibliogr. p.121-141.

Reproduction de : Thèse doctorat : Médecine. Biologie cellualire : Reims : 2006. / Titre provenant de l'écran-titre. Bibliogr. p.163-218.

Reproduction de : Habilitation à diriger des recherches : Sciences économiques : Lille 1 : 2006. / Synthèse des travaux. N° d'ordre (Lille 1) : 502. Curriculum vitae. Titre provenant de la page de titre du document numérisé. Bibliogr. p. 42-48. Liste des publications.

The effects of neutron displacement damage on materials are sensitive to neutron energy spectra. In controlled neutron damage experiments, a well characterized neutron flux spectrum is critical in determining the equivalent dose for displacement damage. Two techniques were used to characterize the neutron flux spectra in the University of Texas at Austin TRIGA research nuclear reactor. The first technique uses a standard method of measuring the reaction rates of two identical metal foils, one of which was irradiated in a Cd cover, the other of which was irradiated bare. Assuming an analytic form of the neutron spectrum the reaction rates were used to determine an approximate spectrum. The second technique uses the reaction rates measured from a set of activated metal foils along with two spectral unfolding techniques to approximate and then refine the neutron spectrum. A Matlab code was developed which fits radiative capture reaction rates to an approximate spectrum using a least squares approach. The result was used as an initial guess in a second Matlab code which refines the epithermal and fast energy ranges of the spectrum using reaction rates from threshold reactions. Errors in the reaction rates calculated from the resulting spectrum to the measured reaction rates were used to assess the accuracy of the final neutron spectrum. / text