Search results for "otolith"
showing 10 items of 149 documents
Zircon reconnaissance dating of Proterozoic gneisses along the Kunene River of northwestern Namibia
2015
Abstract The northern margin of the Epupa Metamorphic Complex (EMC) along the Kunene River in NW Namibia is one of the geologically least known terranes in Africa because of its remoteness and difficult accessibility. We report field relationships and reconnaissance zircon ages for granitoid gneisses from a 120 km foot-traverse along the Kunene River between the Ruacana Falls in the east and Marienfluss in the west. Most rocks are late Palaeoproterozoic in age and correlate well with similar rocks of the EMC farther south in Kaokoland (1757–1835 Ma, one sample 1861 Ma) and with granitoid rocks in the Kamanjab Inlier, some 400 km SE of the Kunene River (1801–1836 Ma). All these rocks constit…
Oxygen and carbon isoscapes for the Baltic Sea : Testing their applicability in fish migration studies
2017
Conventional tags applied to individuals have been used to investigate animal movement, but these methods require tagged individuals be recaptured. Maps of regional isotopic variability known as “isoscapes” offer potential for various applications in migration research without tagging wherein isotope values of tissues are compared to environmental isotope values. In this study, we present the spatial variability in oxygen (δ18OH2O) and dissolved inorganic carbon (δ13CDIC) isotope values of Baltic Sea water. We also provide an example of how these isoscapes can reveal locations of individual animal via spatial probability surface maps, using the high-resolution salmon otolith isotope data fr…
Age and origin of the Böllsteiner Odenwald
2001
The granitoid protoliths of the gneisses of the Bollsteiner Odenwald, a part of the Mid German Crystalline Rise, intruded at 405 ± 3 Ma. This age was obtained by single zircon 207Pb/206Pb evaporation measurements. It is supported by an upper discordia intercept age of 410 ± 11 Ma from single zircon U/Pb data. These granitoids were derived from hybrid magmas according to their geochemical characteristics. Inherited zircon grains with apparent ages of 882 and 1138 Ma further constrain the source heterogeneity. The isotope data with Nd model ages for the granitoid gneisses between 1.3 and 1.7 Ga also underline the involvement of Proterozoic material into the magma sources. Since the geochemica…
A new approach for actinic defect inspection of EUVL multilayer mask blanks: Standing wave photoemission electron microscopy
2006
Extreme ultraviolet lithography (EUVL) at 13.5 nm is the next generation lithography technique capable of printing sub-50 nm structures. With decreasing feature sizes to be printed, the requirements for the lithography mask also become more stringent in terms of defect sizes and densities that are still acceptable and the development of lithography optics has to go along with the development of new mask defect inspection techniques that are fast and offer high resolution (preferable in the range of the minimum feature size) at the same time. We report on the development and experimental results of a new 'at wavelength' full-field imaging technique for defect inspection of multilayer mask bl…
High speed microfluidic prototyping by programmable proximity aperture MeV ion beam lithography
2013
Abstract Microfluidics refers to the science and technology for controlling and manipulating fluids that flow along microchannels. For the development of complex prototypes, many microfluidic test structures are required first. Normally, these devices are fabricated via photolithography. This technique requires a photomask for transferring a pattern to photoresists by exposing with UV light. However, this method can be slow when a new structure is required to change. This is because a series of photomasks are needed, which is time consuming and costly. Here, we present a programmable proximity aperture lithography (PPAL) technique for the development of microfluidic prototype in poly(methyl…
U-Pb zircon geochronology and phase equilibria modelling of a mafi c eclogite from the Sumdo complex of south-east Tibet: insights into prograde zirc…
2017
Abstract The Sumdo complex is a Permian–Triassic eclogitic metamorphic belt in south-east Tibet, which marks the location of a suture zone that separates the northern and southern Lhasa terranes. An integrated geochronological and petrological study of a mafic eclogite from the complex has constrained its tectonometamorphic history and provides a case study of zircon growth in eclogite as a product of prograde dissolution–precipitation. In situ U–Pb geochronology indicates that the eclogite contains a single population of zircon with a crystallisation age of 273.6 ± 2.8 Ma. The morphology and chemistry of the zircon grains are consistent with growth by dissolution–precipitation of protolith…
Laser Beam Lithography For 3-D Surface Patterning
1993
A low power laser processing unit, for microlithographic applications on non-planar surfaces, is described. By combining proper laser beam handling, micropositioning, software control and surface coating techniques, a 5-axis robotic system for laser writing has been set up. Light from a He-Cd laser source is fiber-delivered to a writing head, which moves around a resist coated solid object. After exposure, traditional wet processing can be applied. The unit is capable of patterning metal films deposited on samples up to a size of 50x50x100 mm, with 5 micrometer spatial resolution. An application in 3-D circuit fabrication is presented.
A MODEL FOR VESTIBULAR FUNCTION IN ALTERED GRAVITATIONAL STATES
1979
ABSTRACT During evolution, the vestibular organ was made to serve mainly two purposes: 1) to guide eye movements during sharp turns, so that the point of fixation in the visual field can be kept steady, a function accomplished by the semicircular canal system and 2) to indicate the terrestrial vertical, so that upright posture and gait can be maintained even in the dark. The otolith system serves the latter purpose. Since the function of the semicircular canal system does not depend on gravity, it is not grossly disturbed by gravitational levels different from 1 g . The proper function of the otolith system depends entirely on the presence of a gravitational force vector of 9.8/m/sec2 direc…
The relationship between stocking eggs in boreal spawning rivers and the abundance of brown trout parr
2015
Abstract Stocking with eggs has been widely used as a management measure to support degraded salmonid stocks. In Finland, Atlantic salmon and both sea-migrating and lake-migrating brown trout are stocked as eggs, alevins, fry, parr, and smolt, whereas trout are also stocked as mature fish. The aim of this stocking is to improve catches and to support collapsed spawning stocks. We assessed the success of stocking with brown trout eggs in a study of 17 Finnish boreal forest rivers, of which 9 were subject to egg stocking. All rivers contained some naturally spawning trout. In 16 rivers, including non-stocking years and unstocked rivers, egg stocking did not increase the total (wild and stocke…