Chlorophyll

The distribution of chlorophyll is considered, followed by an historical survey leading to the establishment of the chemical constitution of chlorophylls a and b. Their use as permitted food colours in many countries is discussed. A section gives the commercial production of coppered chlorophyll products for food colouring. Finally, the laboratory preparation, analysis and chromatographic examination of chlorophyll are described in some detail.     

Recognizing novel views of three-dimensional objects.

Examined how novel, 3-dimensional shapes are represented in long-term memory and how this might be differentially affected by monocular and binocular viewing in 3 experiments with a total of 141 undergraduates. Exp 1 established that slide projections of the novel objects could be recognized readily if seen in the same orientation as seen during learning. Exps 2 and 3 examined generalization to novel depth rotations of the objects. Results are consistent with a growing body of recent research showing that, at least under certain conditions, the visual system stores viewpoint-specific representations of objects. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What is important about McCollough effects? Reply to Allan and Siegel.

Criticism of P. C. Dodwell and G. K. Humphrey's (see record 1990-14039-001) functional theory of the McCollough effect (ME) is answered. L. Allan and S. Siegel (see record 1993-28482-001) claim that MEs can be explained as classical conditioning effects. It is not disputed that the association-forming process in MEs shares much in common with classical conditioning, but there are still problems, practical and theoretical, with this account. It also misdirects attention from more important matters. The role of MEs in assuring a proper fit between representation and environment is reasserted, which seems to be the strongest reason for studying these effects. The functional theory aims to model the processes of error correction by means of which valid representation of the environment is maintained. It therefore belongs in a different tradition from that proclaimed by its critics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mesh refinement and iterative solution methods for finite element computations

Global and element residuals are introduced to determine a posteriori, computable, error bounds for finite element computations on a given mesh. The element residuals provide a criterion for determining where a finite element mesh requires refinement. This indicator is implemented in an algorithm in a finite element research program. There it is utilized to automatically refine the mesh for sample two-point problems exhibiting boundary layer and interior layer solutions. Results for both linear and nonlinear problems are presented. An important aspect of this investigation concerns the use of adaptive refinement in conjunction with iterative methods for system solution. As the mesh is being enriched through the refinement process, the solution on a given mesh provides an accurate starting iterate for the next mesh, and so on. A wide range of iterative methods are examined in a feasibility study and strategies for interweaving refinement and iteration are compared.     

Experimental study of the internal fluid dynamics of forming drops

A non-disturbing photochromic flow visualization technique has been used to study fluid flow conditions within the vertical core region of organic liquid drops growing from a single nozzle in an equilibrated water phase. The indicator 1,3,3-trimethylindolino-6′-nitrobenzopyrospiran (0.015%), which was dissolved in the dispersed phase produced extremely fine tracer lines in the drops when irradiated with UV light from a multipulse nitrogen laser. High speed cinephotographs of the observed time lines were used to estimate axial and radial velocity components by means of a numerical mass balance technique. By substitution in the Navier-Stokes equations it is shown how the axial and radial pressure change distributions may be obtained from the velocity measurements.     

Folivory in Fruit Bats: Leaves Provide a Natural Source of Calicum

Leaves are an important dietary source of carbohydrates and protein, and an especially rich source of calcium for bats. Most studies of leaf eating by fruit bats have suggested that only male bats feed on leaves. In this study, 23 wild-caught Tongan fruit bats (Pteropus tonganus) were used in feeding trials conducted in an outdoor enclosure. The number of leaves and percentage of each leaf eaten were recorded for each bat on a daily basis, and these data were then multiplied by a calcium constant that was derived from a chemical analysis of leaves from Callophylum neo-ebudicum. Leaves of C. neo-ebudicum that were available in the enclosure were consumed by 82.7% of the bats. Overall, males consumed leaves in greater quantities and with higher frequency than females. Bats that consumed leaves on a regular basis consumed up to 46% more calcium to their diet compared with bats that did not regularly consume leaves. Leaves may represent a readily available, widely used, concentrated source of minerals for foraging bats, and have the potential to contribute significantly to the total amount of ingested calcium.     

A Comparison of Gel Permeation Chromatography and Liquid Chromatography for Epoxy Resin Analysis

Gel permeation chromatography and liquid Chromatography are used for analyzing various epoxy resins. The chromatograms are compared with related information available from each. Because the separation is based on different principles, each method gives unique and different information about the same sample. For a complete analysis of epoxy resins, both techniques seem to be required.