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| Nouet, Julius; Bassinot, Franck. |
| Several authors suggested that the thinning, with increasing depth of deposition, of calcite X-ray diffractometry (XRD) peaks obtained on planktonic foraminifera tests resulted from the preferential removal of their poorly crystallized parts as dissolution increases. By deconvolving XRD peak (104) from Globorotalia tumida (surface sediments, Sierra Leone Rise depth transect), we show that the full width at midheight does not depend only upon crystallinity, but reflects also the chemical and structural heterogeneity of foraminifera tests, which results in closely spaced, individual (104) diffraction peaks corresponding to phases with slightly different Mg contents. G. tumida contains two calcite phases: a well crystallized, Mg-poor calcite and a poorly... |
| Tipo: Text |
Palavras-chave: Dissolution; Foraminifera; X-ray diffraction; Crystallinity; Deconvolution. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34626/32973.pdf |
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| Wang,Yugao; Zhang,Liming; Li,Xinglin; Gao,Wenyuan. |
| The starches obtained from two different yam residues, which were treated with alkali(starch-A) or enzyme (starch-E), were studied and compared with yam starch isolated using ordinary method (starch-O) for morphological, crystalline pattern, thermal, and pasting properties. The results revealed that the amylose content of three starches ranged from 19.47 to 22.17%. The granule surfaces of starch-A and starch-E were as smooth as that of starch-O. The crystalline pattern of the three starches was a C-type. The transition temperatures (To, Tp and Tc) varied from 70.11 to 73.64, 79.23 to 81.74, and 84.30 to 86.65 ºC, respectively. The starch-E showed the highest Δ Hgel, followed by the starch-A, while it was lowest for the starch-O. According to the viscosity... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Yam starch; Yam residue; Thermal; Crystallinity; Pasting property. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000200004 |
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