scholarly journals Grain size trends and correlation analysis in highly ordered grain line structure of bismuth silicate (Bi4Si3O12) micro-crystals

2009 ◽  
Vol 41 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Z.G. Zhang ◽  
X.F. Wang ◽  
Q.Q. Tian ◽  
C.L. Yu

Highly ordered bismuth silicate micro-crystals have been grown by sintering method at 800?C for the first time. The samples were characterized for structural and surface morphological properties by X-ray diffraction (XRD) and Environmental scanning electron microscopy (ESEM). The result shows that a pure cubic phase (Bi4Si3O12) was obtained. The Bi4Si3O12 grains always distribute in pairs on both sides and arrange grain lines. There are two types of grain size trend along with the growth direction of the grain line. One trend is gradually increased or decreased and the other trend is basically unchanged. In most cases the grain size trends on both sides of one line are approximately consistent and there is a highly positive correlation between the grain growth rates on both sides of one line. The highly positive correlation analysis indicates a relationship between grain growth rates on both sides, such as when the value for one grain growth rate increases, the value for the other grain growth rate in pairs also increases. If the grain size trends on both sides are thoroughly inconsistent and there is a nonlinear relationship between grain growth rates on both sides in one line, these two trends may belong to two types respectively.

1996 ◽  
Vol 42 (141) ◽  
pp. 255-260 ◽  
Author(s):  
R. B Alley ◽  
G. A. Woods

AbstractIntercept analysis of approximately bi-yearly vertical thin sections from the upper part of the GISP2 ice Core, central Greenland, shows that grain-size ranges increase with increasing age. This demonstrates that something in the ice affects grain-growth rates, and that grain-size cannot be used directly in paleothermometry as has been proposed. Correlation of grain-growth rates to chemical and isotopic data indicates slower growth in ice with higher impurity concentrations, and especially slow growth in “forest-fire” layers containing abundant ammonium; however, the impurity/grain-growth relations are quite noisy. Little correlation is found between growth rate and isotopic composition of ice.


1996 ◽  
Vol 42 (141) ◽  
pp. 255-260 ◽  
Author(s):  
R. B Alley ◽  
G. A. Woods

AbstractIntercept analysis of approximately bi-yearly vertical thin sections from the upper part of the GISP2 ice Core, central Greenland, shows that grain-size ranges increase with increasing age. This demonstrates that something in the ice affects grain-growth rates, and that grain-size cannot be used directly in paleothermometry as has been proposed. Correlation of grain-growth rates to chemical and isotopic data indicates slower growth in ice with higher impurity concentrations, and especially slow growth in “forest-fire” layers containing abundant ammonium; however, the impurity/grain-growth relations are quite noisy. Little correlation is found between growth rate and isotopic composition of ice.


1980 ◽  
Vol 94 (1) ◽  
pp. 95-104 ◽  
Author(s):  
G. J. Rowlands

SummaryBlood samples were taken at 9, 10 and 11 weeks of age from 230 male Hereford × Friesian calves, the progeny of 12 Hereford bulls. Concentrations of blood glucose, serum albumin, inorganic phosphate and sodium were measured and correlated with body weights and growth rates until slaughter at 19½ months of age.Correlations between growth rates and glucose concentrations (0·44) and between growth rates and albumin concentrations (0·38) were observed until 4 months of age. Similar correlations between body weights and blood glucose or albumin concentrations persisted until 6 months of age. By 10 months, however, the correlations had begun to decline, and by slaughter they had become insignificant.Correlations between growth rates and inorganic phosphate or sodium concentrations were smaller, and also decreased with age.The effect of hypoglycaemia on growth rate was compared with the effect of enzootic pneumonia. Although the 10% of calves with the lowest glucose concentrations were growing 24% more slowly than the other calves at the time of sampling, this growth depression was not related to pneumonia, and they subsequently made up for most of the early loss of growth.Three blood samples were also taken from 22 Hereford bulls. No significant correlations were observed between the blood composition of the bulls and the body weights or weight gains of their progeny.


1967 ◽  
Vol 15 (1) ◽  
pp. 95 ◽  
Author(s):  
RF Parsons ◽  
RL Specht

In southern Australia, deep calcareous and deep siliceous sands each carry a distinctive assemblage of eucalypts. Three of these species with contrasting edaphic ranges were investigated: Eucalyptus baxteri, which is widespread on acidic soils and is never found on highly alkaline soils like the calcareous sands; E. incrassata, which is widespread on acidic and neutral soils, occurs occasionally on some highly alkaline soils, but is also absent from calcareous beach sands; and E. diversifolia, which is found on both acidic and highly alkaline soils and is widespread on calcareous beach sands. All three species occur on siliceous sands, with E. baxteri in wetter areas than the other two species. Comparative pot experiments in which typical calcareous and siliceous sands were used showed that: (1) E. baxteri is stunted by severe lime chlorosis when grown on calcareous sand, while the other two species are not affected. (2) E. baxteri markedly outyields the other two species on siliceous sands. It is suggested that E. baxteri is absent from calcareous sands because it is physiologically intolerant of highly alkaline soils, and that E. baxteri replaces the other two species on the wetter siliceous sands because its faster growth rate enables it to outcompete them when rainfall is adequate. However, the slower growth rates of E. diversifolia and E. incrassata will be accompanied by slower rates of water use and this may give them an advantage over E. baxteri on drier siliceous sands. The wide edaphic range of E. diversifolia is considered to be the outcome of the wide physiological tolerance of individual plants rather than of intraspecific differentiation.


2005 ◽  
Vol 72 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Alfonso Zecconi ◽  
Enrica Binda ◽  
Vitaliano Borromeo ◽  
Renata Piccinini

Staphylococcus aureus isolates produce several pathogenic factors. The combination of these products influences the pathogenic role of different isolates, but their specific effects are well known in the pathogenesis of udder infections. This study focused on the association of polymorphism of the coagulase gene, protein A gene, collagen-binding protein gene, and of fibrinogen-binding protein gene on somatic cell count (SCC) and on Staph. aureus growth rate. Fifty Staph. aureus isolates from 13 dairy cow herds, located in seven different provinces, were considered. The results showed a low frequency of cna gene, similar to the one observed in human isolates. Meanwhile, the high frequency of efb gene indirectly confirmed the role of this factor in bacterial pathogenesis, being associated with adhesion to epithelia. The association of these two single genes with SCC and growth rate showed to be not significant. The polymorphism of spa gene was confirmed to be significantly associated with inflammatory response and growth rate, albeit with a pattern different from the one suggested for human isolates. Sorting of isolates based on the clusters obtained by combining polymorphisms of spa and coa genes and the presence of cna and efb genes, showed that a single cluster (cluster V) was prevalent in the different herds and provinces, while the other six clusters identified were widely spread among the remaining 60% of the isolates. Results showed that clusters VI and VII had significantly higher growth rates at 3, 4, and 6 h in comparison with the other clusters. Meanwhile, quarters infected with these strains showed significantly lower SCC levels. The frequency of isolates from cluster V, suggested that they should possess pathogenic factors increasing their invasiveness, even if in the presence of a stronger inflammatory response. These results indirectly confirm previous findings on the different interactions between isolates and the udder immune system. They also suggest that isolates with higher growth rates and inducing a lower inflammatory response have better chances to spread among the herd. The relatively simple genomic method proposed in this study could be applied by an increasing number of diagnostic laboratories and could be useful in studying the epidemiology of Staph. aureus intramammary infections in dairy herds when collecting data from the field.


1983 ◽  
Vol 23 (122) ◽  
pp. 228 ◽  
Author(s):  
MPB Deland ◽  
RW Ponzoni ◽  
RW McNeil

Hereford, Charolais and Brahman sires were mated to Hereford, Shorthorn, Jersey and Friesian xshorthorn cows for four successive years from June 1969 at Struan Research Centre in South Australia. Assistance was given during 15 .9% of calvings resulting from Charolais sires, 6.8% resulting from Brahman sires and 2.1% from Hereford sires (differences statistically significant, P < 0 05). A greater percentage of Friesian x Shorthorn (13.8) than of Shorthorn (5.0) or Jersey (4 3) cows were assisted at birth (P< 0.05). There were no significant differences between the percentage of Hereford cows assisted (10.9) and that of any of the other dam breeds. There were no significant differences in calf mortality among sire breeds or among dam breeds. Charolais-sired calves were heavier at birth, 270,340 and 430 d old and had heavier (1 95 kg) carcasses with a smaller proportion of fat than Brahman- and Hereford-sired carcasses (180 and 167 kg respectively) at 430d old. Brahman-sired calves were heavier than Hereford-sired calves at birth, 370, 430 d old. However, they were significantly lighter at 270 d old. Hereford cows gave birth to significantly heavier calves than Shorthorn and Jersey cows but there were no clear differences due to dam breed in growth rates of calves, carcass weights or composition. It was concluded that the use of Charolais sires in the lower South East of South Australia can result in significant increases in the growth rate of slaughter cattle and in the production of leaner carcasses. Brahman sires did not exhibit clear advantages over Hereford sires. No definite conclusions could be drawn about the dam breeds examined in the study.


1971 ◽  
Vol 48 (4) ◽  
pp. 815-827 ◽  
Author(s):  
D. A. Saville

The interactions between electrical tractions at the interface of a liquid jet and instability phenomena are studied with emphasis on effects due to interfacial charge relaxation. Charge relaxation causes the oscillatory growth of a perturbation. When viscous effects are small, small fields tend to decrease the growth rate of the axisymmetric mode, up to a point, and precipitate instability of the non-axisymmetric modes. Still larger field strengths increase the growth rates of asymmetric as well as axisymmetric modes. Instabilities characterized by highfrequency oscillations appear to persist even though the charge relaxation phenomena may be quite rapid. When, on the other hand, viscous effects predominate the only unstable disturbance form is the axisymmetric one, although the manner of growth may be oscillatory.


2002 ◽  
Vol 139 (2) ◽  
pp. 169-181 ◽  
Author(s):  
L. E. R. DAWSON ◽  
A. F. CARSON

A study was carried out on five lowland farms in Northern Ireland over 3 years to investigate the effect of crossbred ewe and ram genotype on ewe prolificacy, lamb viability and weaned lamb output. Four crossbred ewe genotypes were sourced from six hill farms involved in a previous study – Bluefaced Leicester×Blackface (BLXB), Texel×Blackface (TXB), Suffolk×Cheviot (SXCH) and Texel×Cheviot (TXCH). On each farm, groups of 20–30 of each crossbred ewe genotype were mated with Suffolk or Texel rams. Throughout the 3 years of the study, the ewe genotypes lambed at 1, 2 and 3 years of age. Within each of the ram breeds, high lean growth index rams sourced from UK sire reference schemes were compared with rams sourced from flocks not involved in objective genetic improvement programmes (control). BLXB ewes were the most prolific of the four ewe genotypes producing 1.73 lambs per ewe lambed compared with 1.47 for TXB, 1.46 for SXCH and 1.41 for TXCH (P<0.001). Lamb mortality was similar for the four ewe genotypes, thus number of lambs weaned was greatest for the BLXB ewes (P<0.001) with the other three crosses producing similar numbers of lambs. A greater proportion (P<0.05) of SXCH ewes lambed without assistance compared with BLXB and TXB ewes and a greater proportion of TXCH ewes had abundant supplies of colostrum compared with the other crosses (P<0.10). Output of weaned lamb per ewe lambed and per ewe metabolic live weight (P<0.001) was greatest in the BLXB ewes. Ewe productivity, prolificacy, number of lambs weaned and the proportion of ewes lambing without assistance increased with ewe age (P<0.001). Lamb growth rate from birth to 6 weeks and from birth to weaning increased with ewe age (P<0.05). Crossbred ewes lambing at 3 years old had a greater output of weaned lamb compared with ewes lambing at 1 and 2 years old (P<0.001). Ram genotype had no effect on ewe prolificacy, lamb viability or pre-weaning growth rates, although Texel-sired lambs had lower birth weights than Suffolk-sired lambs and control-sired lambs had lower birth weights than high lean index-sired lambs (P<0.05).


1984 ◽  
Vol 35 ◽  
Author(s):  
S.J. Krause ◽  
S.R. Wilson ◽  
W.M. Paulson ◽  
R.B. Gregory

ABSTRACTPolycrystalline silicon films of 300 nm thickness were deposited on oxidized wafer surfaces, implanted with As, and annealed on a Varian IA 200 rapid thermal annealer. Transmission electron microscopy was used to study through-thickness and cross sectional views of grain size and morphology of as-deposited and of transient annealed films. A bimoda] distribution of grain sizes was present in as-deposited polycrystalline silicon films. The first population was due to columnar growth of some grains to a final average diameter of 20 rm. The second population of small equiaxed grains of 5 nm average diameter were formed early in the deposition process. During transient annealing grains in the first population grew rapidly up to 280-nm equiaxed grains. After this the growth rate decreased due to the grain size reaching the thickness of the film. Grains in the second population grew rapidly up to a size of 150 nm, after which the growth rate was lowered due to grains impinging upon one another. The grain growth processes for both populations have been described with a modified model for interfacially driven grain growth. This model accounts for diffusion and grain growth which occur with rapidly rising and falling temperatures during short annealing times characteristic of transient annealing processes.


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