The role of shape disorder in the collective behaviour of aligned fibrous matter

We show how bending rigidity and shape disorder control the mechanical properties of fiber bundles.

The Influence of Different Retting Processes on the Strength of Fibres obtained from Poliostigma raticulatum, Grewia mollis, Cissus populnea and Hibiscus sabdariffa

<p class="1Body">The extraction of vegetable fibres from different parts of plants has been a major focal point in the search for natural fibres that would substitute synthetic fibres. Fibres from <em>Poliostigma reticulatum</em>, <em>Grewia mollis,</em> <em>Cissus populnea</em> and<em> Hibiscus sabdariffa</em> were extracted by water and chemical retting. In chemical retting different concentrations of NaOH and NH₄OH were used. The extracted fibres were further purified and their tensile strength measured. The pH of water was measured as retting progresses and observed to increase as the retting time increases. This was ascribed to the secretion of enzymes by microorganisms as they acted on the mucilaginous matter of the bast with the resultant loosening of the fibres. The tensile strength of the fibres was determined using the Shirley Testometric 220D and was observed to gradual decline as the retting time increases. This was attributed to the continual removal of non-fibrous matter and the freeing of the fibres in the composite. However, beyond the fifth week of retting, no appreciable change in tensile strength was observed. This suggested that most of the non-fibrous matter have been solublized and utilized as source of nutrients and energy by the microorganisms. Acidic metabolites were produced due to microbial activities may have changed the pH of the medium and subsequently hindered their growth. In chemical retting, as the concentration of the medium increases the strength of the fibres decreases to a minimum then remain constant. This was accredited to the breakdown of inter- molecular bonds between non-fibrous substances and the fibres. And subsequently, the non-fibrous components separate from the fibres and dissolved in the medium revealing the actual fibres strength. It was therefore, opined that retted fibres in water, 5% NH₄OH and 15% NaOH are clearer and lustrous for all sample except those from Kargo<em>.</em></p>

On some alvine concretions found in the colon of a young man in lancashire, after death

After detailing the above, and adverting to two other cases of intestinal concretions, Mr. Children describes the appearance and composition of the calculi. The nucleus of each was a plumstone enveloped in a compact coating of phosphate of lime and ammoniaco-magnesian phosphate, and of a fibrous substance alternating in layers; the animal matter which they contain is chiefly gelatine and a little resin; and the fibrous vegetable matter appears to have been derived from the inner coat enveloping the farinaceous part of the oat. From other cases, which the author mentions at the conclusion of his paper, it appears that oatmeal has not unfrequently contributed to the deposition upon intestinal concretions; and from the analyses which he quotes, the same fibrous matter has been detected in them by other chemists.