Specialised emission pattern of leaf trace in a late Permian (253 million-years old) conifer

We have shown the feasibility of 20 nm lateral resolution in both topographic and elemental imaging using probes of this size from a liquid metal ion source (LMIS) scanning ion microprobe (SIM). This performance, which approaches the intrinsic resolution limits of secondary ion mass spectrometry (SIMS), was attained by limiting the size of the beam defining aperture (5μm) to subtend a semiangle at the source of 0.16 mr. The ensuing probe current, in our chromatic-aberration limited optical system, was 1.6 pA with Ga+ or In+ sources. Although unique applications of such low current probes have been demonstrated,) the stringent alignment requirements which they imposed made their routine use impractical. For instance, the occasional tendency of the LMIS to shift its emission pattern caused severe misalignment problems.

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Oriented Luminescent Nanostructures From Single Molecules Of Conjugated Polymers

MRS Proceedings ◽

10.1557/proc-771-l9.8 ◽

2003 ◽

Vol 771 ◽

Author(s):

Adosh Mehta ◽

Pradeep Kumar ◽

Jie Zheng ◽

Robert M. Dickson ◽

Bobby Sumpter ◽

...

Keyword(s):

Conjugated Polymers ◽

Polarization Anisotropy ◽

Emission Pattern ◽

Spectral Signatures ◽

Dipole Emission ◽

Ink Jet ◽

Molecular Scale ◽

Jet Printing ◽

Photochemical Stability ◽

Printing Techniques

AbstractDipole emission pattern imaging experiments on single chains of common conjugated polymers (solubilized poly phenylene vinylenes) isolated by ink-jet printing techniques have revealed surprising uniformity in transition moment orientation perpendicular to the support substrate. In addition to uniform orientation, these species show a number of striking differences in photochemical stability, polarization anisotropy,[1] and spectral signatures[2] with respect to similar (well-studied) molecules dispersed in dilute thin-films. Combined with molecular mechanics simulation, these results point to a structural picture of a folded macromolecule as a highly ordered cylindrical nanostructure whose long-axis (approximately collinear with the conjugation axis) is oriented, by an electrostatic interaction, perpendicular to the coverglass substrate. These results suggest a number of important applications in nanoscale photonics and molecular-scale optoelectronics.

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Late Permian carbonate concretions in the marine siliciclastic sediments of the Ravnefjeld Formation, East Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v191.5140 ◽

2002 ◽

pp. 126-132

Author(s):

Jesper Kresten Nielsen ◽

Nils-Martin Hanken

Keyword(s):

Mineral Resources ◽

Sedimentary Basins ◽

Sedimentary Facies ◽

Carbonate Reservoir ◽

Upper Permian ◽

Late Permian ◽

East Greenland ◽

Reservoir Rocks ◽

Carbonate Concretions ◽

Siliciclastic Sediments

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kresten Nielsen, J., & Hanken, N.-M. (2002). Late Permian carbonate concretions in the marine siliciclastic sediments of the Ravnefjeld Formation, East Greenland. Geology of Greenland Survey Bulletin, 191, 126-132. https://doi.org/10.34194/ggub.v191.5140 _______________ This investigation of carbonate concretions from the Late Permian Ravnefjeld Formation in East Greenland forms part of the multi-disciplinary research project Resources of the sedimentary basins of North and East Greenland (TUPOLAR; Stemmerik et al. 1996, 1999). The TUPOLAR project focuses on investigations and evaluation of potential hydrocarbon and mineral resources of the Upper Permian – Mesozoic sedimentary basins. In this context, the Upper Permian Ravnefjeld Formation occupies a pivotal position because it contains local mineralisations and has source rock potential for hydrocarbons adjacent to potential carbonate reservoir rocks of the partly time-equivalent Wegener Halvø Formation (Harpøth et al. 1986; Surlyk et al. 1986; Stemmerik et al. 1998; Pedersen & Stendal 2000). A better understanding of the sedimentary facies and diagenesis of the Ravnefjeld Formation is therefore crucial for an evaluation of the economic potential of East Greenland.

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