scholarly journals A new myriacanthid holocephalian from the Early Jurassic of Denmark.

2017 ◽  
Vol 65 ◽  
pp. 161-170
Author(s):  
Christopher J. Duffin ◽  
Jesper Milàn
Keyword(s):  
Surface Relief ◽  
Early Jurassic ◽  
Plate Surface ◽  
Mandibular Tooth ◽  
Tooth Plate ◽  
Occlusal Surfaces

A new myriacanthid holocephalian is described from the Hasle Formation (probably the Uptonia jamesoni subzone to the Acanthopleuroceras valdani subzone, Early Pliensbachian, Early Jurassic) of Bornholm, Denmark, on the basis of isolated upper posterior (palatine) and lower posterior (mandibular) tooth plates. Oblidens bornholmensis gen. et sp. nov. differs from all other myriacanthids for which the same dental elements are known, in the distribution of the hypermineralised tissue covering the occlusal surfaces of the tooth plates, and the arrangement of the ridges transecting the tooth plate surface and so varying their surface relief. Oblidens is the first myriacanthid holocephalian to be recorded both from the Pliensbachian and from Denmark. The presence of a further, undetermined myriacanthid tooth plate is noted from the same locality.

X-ray Gabor holography

1995 ◽  
Vol 53 ◽  
pp. 612-613
Author(s):  
Steve Lindaas ◽  
Chris Jacobsen ◽  
Alex Kalinovsky ◽  
Malcolm Howells
Keyword(s):  
Surface Relief ◽  
Biological Imaging ◽  
Specimen Preparation ◽  
X Rays ◽  
X Ray ◽  
Water Window ◽  
Biological Objects ◽  
Transmission Imaging ◽  
Atomic Force ◽  
Electron Microscopes

Soft x-ray microscopy offers an approach to transmission imaging of wet, micron-thick biological objects at a resolution superior to that of optical microscopes and with less specimen preparation/manipulation than electron microscopes. Gabor holography has unique characteristics which make it particularly well suited for certain investigations: it requires no prefocussing, it is compatible with flash x-ray sources, and it is able to use the whole footprint of multimode sources. Our method serves to refine this technique in anticipation of the development of suitable flash sources (such as x-ray lasers) and to develop cryo capabilities with which to reduce specimen damage. Our primary emphasis has been on biological imaging so we use x-rays in the water window (between the Oxygen-K and Carbon-K absorption edges) with which we record holograms in vacuum or in air.The hologram is recorded on a high resolution recording medium; our work employs the photoresist poly(methylmethacrylate) (PMMA). Following resist “development” (solvent etching), a surface relief pattern is produced which an atomic force microscope is aptly suited to image.

Features of rolled billets milling and methods for its improvement

2020 ◽  
pp. 67-71
Author(s):  
M.Z. Pevzner ◽  
S.A. Smertin
Keyword(s):  
Surface Relief ◽  
Regression Dependence ◽  
Processing Mode ◽  
Hot Rolled

A model of the formation of the surface relief hiring milling of rolled billets and a method for selecting the milling mode based determining the regression dependence of the resulting relief on the processing mode are proposed. It is shown that the regulation of the processing mode as the tool wears out allows to increase the milling resource and productivity. Keywords hot rolled strips, milling, rolling, relic resistance, mill. [email protected]

SCLEROCHRONOLOGY OF THE EARLY JURASSIC LITHIOTID BIVALVES: SEARCHING FOR SYMBIOSIS

2016 ◽  
Author(s):  
Daniel Killam ◽  
◽  
Matthew E. Clapham ◽  
Renato Posenato ◽  
Marco Franceschi
Keyword(s):  
Early Jurassic

EARLY JURASSIC EARTH SYSTEM AND TIMESCALE (JET): MOCHRAS (WALES) COREHOLE

2016 ◽  
Author(s):  
James V. Browning ◽  
◽  
Kenneth G. Miller ◽  
Linda A. Hinnov ◽  
Kenneth H. Williford
Keyword(s):  
Early Jurassic ◽  
Earth System
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