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Showing 1 to 20 of 753 for “"quaternary"”.
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Electrodeposition of FeCoNiCu quaternary system
… and curved areas. In this dissertation, FeCoNiCu quaternary alloy system was investigated, both experimentally and theoretically, for fabrication of multilayers, grating structures, and nanowires. Multilayer structures are composed of alternating ferromagnetic and nonmagnetic nanometric layers, …
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Quaternary grounding-line fluctuations in Antarctica
The West Antarctic Ice Sheet may be prone to rapid collapse under climates warmer than today due to a dynamic instability at the grounding line, where the ice sheet goes afloat over seawater. However, there is to-date no conclusive evidence that the ice sheet has gone away in last few million …
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Evaluating Immunotoxicity of Quaternary Ammonium Compounds
… dimethyl ammonium chloride (DDAC) are common quaternary ammonium compounds used as disinfectants in households, medical, and restaurant settings. They cause occupational skin and respiratory hazards in humans, and developmental and reproductive toxicity in mice. They also cause increased …
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Quaternary geology of Sargent County, North Dakota
… general geologic history of the county for the Quaternary Period. </p><p> A geologic map of the county was prepared using field data, topo graphic maps, aerial stereopairs, and soil maps. A map showing surface sediment origin was subsequently made using the available field and laboratory …
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Quaternary geology of Rolette County, North Dakota
<p>Rolette County contains approximately 942 square miles in north central North Dakota (Tps. 159-164 N., Rs. 69-73 W.) adjacent to the Canadian border. It includes the southeastern part of the Turtle Mountains and part of the glacial Lake Souris basin. Basic lithologies recognized in the surface …
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Alkylations With Quaternary Salts of 2-Aminomethylindoles
Made available in DSpace on 2014-12-05T19:36:02Z (GMT). No. of bitstreams: 1 0010461.pdf: 2636213 bytes, checksum: 702e2b321691d0b1f04a31979af835e4 (MD5) Previous issue date: 1954
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Later Quaternary archaeological sequences in northern Tanzania
Excavations were undertaken at two deep-stratified rock shelters near Olduvai Gorge in order to ascertain the post-Acheulean archaeological sequence for the area. Shelter sequences document segments of time during the past 150,000 years and allow a new appreciation of the age and cultural …
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Quaternary morphology and paleoenvironmental records of carbonate islands
Here I use a simple numerical model of reef profile evolution to show that the presentday morphology of carbonate islands has developed largely in response to late Pleistocene sea level oscillations in addition to variable vertical motion and reef accretion rates. In particular, large amplitude …
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Synthesis and resolution of enantiomeric quaternary ammonium halides
The purpose of the work described in this thesis was the synthesis of a new class of surfactants containing chiral cationic end groups and the synthesis of two chiral reactant molecules which would react in the presence of these surfactants. The structures of the surfactant and substrate molecules …
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Nonlinear Optics in III-V Quaternary Semiconductor Waveguides
… several optical waveguide designs based on quaternary III-V semiconductors AlGaAsSb and InGaAsP. We present modal analysis for waveguide designs and show that effective mode area much less than 1 $\mu m^{2}$ can be obtained. We also report specific waveguide designs that display …
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Late-quaternary environmental change at Eastbourne, East Sussex
This study is an examination of the late-Quaternary palaeoenvironments of the Eastbourne area, The principal techniques employed are pollen, Foraminifera, Ostracoda, Mollusca and sediment particle size analyses. The lithostratigraphic investigation, using hand auger and a commercial drilling rig, …
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The late quaternary vegetational history of Holderness, Yorkshire
This study was undertaken to reconstruct the regional vegetational history of Holderness, in south-east Yorkshire. It is an area with great potential for palaeo-ecological investigations and yet it has been largely ignored during the great increase of research in this field in recent years. Being …
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Late Quaternary vegetation history of Craven, Yorkshire Dales.
This thesis investigates new late Quaternary vegetation records from four sites in the Craven District of the Yorkshire Dales. The chosen sites fall along an east-west transect broadly following the line of the south Craven Fault. The rationale for site selection was not based on conventional …
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Quaternary glaciation in the Pindus Mountains, Northwest Greece
… and geological evidence for former Quaternary glaciation has been mapped n the Pindus Mountains of Northwest Greece. the dynamics and chronology of glaciation in this area has been established through sedimentological analysis, soil analysis and Uranium-series dating. Four glacial …
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