Linear growth rates of ice crystals grown from the vapor phase

Cultures of Fames annosus originating in Europe could not be distinguished from those originating in North America either by colony appearance, growth rate, pH optimum, or cellulolytic activity. Three growth rate types on 2.5% malt agar were recognized and these are ascribed to individual variation rather than to host or geographical influences. Successive subculturing produced variants that fell into three growth classes. Half of the isolates displayed spontaneous, but reversible, changes in growth rate and colony appearance during subculturing and this is discussed from the standpoint of genetical and environmental influences. Cultures displaying different morphological characteristics and linear-growth rates differed little metabolically; each had a similar pH optimum ranging from 4.6 to 5.5, and each proved capable of altering the initial acidity of the medium to a reaction which was more suitable for growth. Two cultures were characterized by double pH optima at 4.6 and 5.5. Cultures having different linear-growth rates produced about the same dry-weight of mycelium on a cellulose substrate in a semisynthetic nutrient solution. On the basis of a statistical analysis of cellulose utilization by representative isolates it was impossible to distinguish between North American and European cultures.

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Abstract 13513: Serial CT Surveillance of Abdominal Aortic Aneurysm Diameter Demonstrates Predominantly Linear Growth (N-TA 3 CT)

Circulation ◽

10.1161/circ.142.suppl_3.13513 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Sydney Olson ◽

Marniker Wijesinha ◽

Annalise Panthofer ◽

William Blackwelder ◽

Gilbert R Upchurch ◽

...

Keyword(s):

Growth Rate ◽

Growth Rates ◽

Linear Growth ◽

Growth Patterns ◽

Aortic Aneurysms ◽

Transverse Diameter ◽

Invasive Treatment ◽

Abdominal Aortic ◽

Risk Of Rupture ◽

Serial Ct

Objective: Small abdominal aortic aneurysms (AAAs) have a low risk of rupture. Intervention is indicated when diameters exceed established thresholds. This study assessed the growth rates and patterns of AAAs over 2 years as documented on serial CT scans from the Non-Invasive Treatment of AAA Clinical Trial. Methods: 254 patients, 35 females with baseline AAA maximum transverse diameter (MTD) between 3.5-4.5 cm and 219 males with baseline MTD 3.5-5.0 cm, were included in this study. Linear regressions and segmental growth rates were used to model growth rates and patterns. Results: The yearly growth rates of AAA MTDs had a median of 0.17 cm/yr and mean of 0.19 cm/yr ± 0.14 (Figure 1). 10% of AAA displayed minimal to no growth (< 0.05 cm/yr), 62% low growth (0.05-0.25 cm/yr), 28% high growth (> 0.25 cm/yr). Baseline AAA diameter accounted for only 5.4% of growth rate variance (P<0.001, R 2 0.05). Most AAAs displayed linear growth (70%); large variations in interval growth rates occurred infrequently (3% staccato growth, 4% exponential growth); a minority of subjects’ growth patterns were not clearly classifiable (11% indeterminate-not growing, 12% indeterminate-growing) (Figure 2). No patients with baseline MTD < 4.25 cm exceeded sex-specific repair thresholds (males 0 / 92, [95% CI, 0.00-0.06]; females 0 / 25 [95% CI, 0.00-0.25]) in the course of follow-up for as long as two years. Conclusions: The majority of small AAAs exhibit linear growth; large intra-patient growth rate variations were infrequently observed over 2 years. AAA < 4.25 cm can be followed with a CT scan in 2 years with little chance of exceeding interventional MTD thresholds of 5.5 cm for men.

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Crystal growth rates in polar firn

Annals of Glaciology ◽

10.3189/s0260305500011526 ◽

1993 ◽

Vol 18 ◽

pp. 208-210

Author(s):

Hitoshi Shoji ◽

Atau Mitani ◽

Kohji Horita ◽

Chester C. Langway

Keyword(s):

Growth Rate ◽

Plastic Deformation ◽

Crystal Growth ◽

Growth Rates ◽

Strain Field ◽

Crystal Size ◽

Ice Core ◽

Transformation Process ◽

Ice Crystals ◽

Air Bubbles

Continuous crystal-size measurements made on the G6 Antarctic ice core (100m deep) show enhanced growth rates above a depth of 30 m (Zone 1) and in the interval between 70 and 80 m (Zone 2). Crystal growth in Zone 1 most probably takes place by a process of sublimation and condensation. The higher growth rate in Zone 2 is most probably related to the pore close-off transformation process in which a non-uniform strain field is created to form air bubbles by plastic deformation and “cannibalization” of individual ice crystals.

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Morphological Instability of Polyhedral Ice Crystals Growing in Air at Low Temperature

Annals of Glaciology ◽

10.1017/s0260305500010405 ◽

1985 ◽

Vol 6 ◽

pp. 222-224 ◽

Cited By ~ 3

Author(s):

T. Gonda ◽

H. Gomi

Keyword(s):

Low Temperature ◽

Growth Rates ◽

Crystal Size ◽

Air Pressure ◽

Experimental Results ◽

Ice Crystals ◽

Polar Regions ◽

Morphological Instability ◽

Skeletal Structures ◽

Snow Crystals

The morphology of snow crystals growing at a low temperature has been experimentally studied. The habit and the morphological instability of the crystals vary remarkably with air pressure. In addition, the morphological instability of the crystals depends not only on air pressure but also on supersaturation, crystal size, the ratio of growth rates and the ratio of axial lengths. It is supposed from the experimental results that long prisms with small skeletal structures forming at low supersaturation are precipitating in polar regions.

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