Now showing items 1-10 of 410
Photography: Making every photon count
(Nature Publishing Group, 1999-12-23)
More than 150 years after the invention of photography, the underlying solid-state photochemistry is still being investigated and improved. One aspect of continual importance is the efficiency of the image-recording stage, ...
Optimised isolation procedure for biologically active compounds nimbolide and 28-deoxonimbolide from Azadirachta indica leaves
(Elsevier: Phytochemistry, 1999-12)
Alpha-linolenic acid has been isolated from fresh A. indica leaves and an optimised procedure for the isolation of the limonoids nimbolide and 28-deoxonimbolide is described.
The extended blue continuum and line emission around the Central Radio Galaxy in Abell 2597
(American Astronomical Society, 1999-11-10)
We present results from detailed imaging of the centrally dominant radio elliptical galaxy in the cooling flow cluster Abell 2597, using data obtained with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space ...
Studies on the ADP-ribose pyrophosphatase subfamily of the nudix hydrolases and tentative identification of trgB, a gene associated with tellurite resistance
(The American Society for Biochemistry and Molecular Biology: Journal of Biological Chemistry, 1999-11-05)
Four Nudix hydrolase genes, ysa1 from Saccharomyces cerevisiae, orf209 from Escherichia coli, yqkg from Bacillus subtilis, and hi0398 from Hemophilus influenzae were amplified, cloned into an expression vector, and transformed ...
A simple and complete purification of single-walled carbon nanotube materials
(Wiley: Advanced Materials, 1999-11)
Sensitized carrier generation in evaporated thin films and particle dispersions of benzimidazole perylene
(International Society for Optical Engineering, 1999-10)
We studied photoconductivity in particle dispersions and vacuum evaporated films of benzimidazole perylene (BZP) pigment in contact with a tetraphenyldiamine (TPD) hole transport layer. Xerographic photoreceptors based on ...
Nonlinear frequency-dependent selection at a single locus with two alleles and two phenotypes
(Springer Berlin / Heidelberg, 1999-10)
The paper investigates the discrete frequency dynamics of two phenotype diploid models where genotypic fitness is an exponential function of the expected payoff in the matrix game. Phenotypic and genotypic equilibria ...
Image lightness rescaling using sigmoidal contrast enhancement functions
(International Society for Optical Engineering (SPIE), 1999-10)
In color gamut mapping of pictorial images, the lightness rendition of the mapped images plays a major role in the quality of the final image. For color gamut mapping tasks, where the goal is to produce a match to the ...
Papillomavirus DNA replication
(Humana Press: Methods in Molecular Medicine, 1999-09)
Papillomavirus genomes replicate and are maintained as stable extrachromosomal plasmid DNA (episomes) in many cell lines. This process requires the viral E1 and E2 proteins and the origin of replication. The minimal origin ...
A comparative HST imaging study of the host galaxies of radio-quiet quasars, radio-loud quasars and radio galaxies: I
(Blackwell Publishing, 1999-09)
We present the first results from a major HST WFPC2 imaging study aimed at providing the first statistically meaningful comparison of the morphologies, luminosities, scalelengths and colours of the host galaxies of radio-quiet ...