scholarly journals Initial Growth forms of Snow Crystals Growing from Frozen Cloud Droplets

1984 ◽  
Vol 62 (1) ◽  
pp. 190-192 ◽  
Author(s):  
T. Gonda ◽  
T. Yamazaki
Keyword(s):  
Initial Growth ◽  
Growth Forms ◽  
Cloud Droplets ◽  
Snow Crystals

Growth Forms of Snow Crystals

1986 ◽  
pp. 61-66 ◽  
Author(s):  
Toshio Kuroda
Keyword(s):  
Growth Forms ◽  
Snow Crystals

EFFECT OF SEED SOURCE ON GROWTH OF GIANT WILDRYE (Elymus cinereus) AT TWO ELEVATIONS IN INTERIOR BRITISH COLUMBIA

1990 ◽  
Vol 70 (2) ◽  
pp. 551-554 ◽  
Author(s):  
J. W. HALL ◽  
D. G. STOUT ◽  
B. BROOKE
Keyword(s):  
British Columbia ◽  
High Altitude ◽  
Seedling Establishment ◽  
Dry Matter ◽  
Initial Growth ◽  
Growth Forms ◽  
Forage Crop ◽  
Reciprocal Transplants ◽  
Altitude Adaptation ◽  
Low Altitude

Giant wildrye (Elymus cinereus Scribn. & Merr.) plants grown from seed obtained at two altitudes (346, 930 m) were transplanted to two sites (346, 900 m) and observed for 3 yr. Plants from the low altitude source produced more dry matter at both sites. More plants from the low altitude source produced seed heads at the low altitude site but seed head production of plants from the two sources was similar at the high altitude site. Provided studies of germination, seedling establishment and initial growth at different elevations were favorable, seed from low altitude sources could be used indiscriminately for establishing stands of giant wildrye. This would greatly simplify the use of giant wildrye as a forage crop in areas where varying altitude was of concern.Key words: Elymus cinereus, altitude adaptation, growth forms, reciprocal transplants, ecotypes

A numerical study of the effects of cloud droplets on the diffusional growth of snow crystals

2007 ◽  
Vol 84 (4) ◽  
pp. 353-361 ◽  
Author(s):  
Nesvit E. Castellano ◽  
Silvana Gandi ◽  
Eldo E. Ávila
Keyword(s):  
Numerical Study ◽  
Diffusional Growth ◽  
Cloud Droplets ◽  
Snow Crystals

The Fomation of Rain by Coalescence

1950 ◽  
Vol 3 (2) ◽  
pp. 193 ◽  
Author(s):  
EG Bowen
Keyword(s):  
Rainfall Intensity ◽  
Inverse Function ◽  
Heavy Rain ◽  
Drop Diameter ◽  
Maximum Height ◽  
Initial Growth ◽  
Air Velocity ◽  
Cloud Droplets ◽  
Light Rain ◽  
Freezing Level

It is generally acknowledged that drizzle or light rain can fall from clouds which do not reach freezing level and cases have recently bean described in which moderate to heavy rain has been observed to fall from such clouds. A simple theory is developed to account for the phenomenon, based on the initial growth of cloud droplets by condensation followed by the growth of a small fraction of their number by coalescence. These grow in their ascent through the cloud until they are large enough to remain in suspension in the upward air current, after which they fall as min. It is shown that for a given set of cloud conditions the maximum height reached by the drops increases with increasing vertical air velocity and that the size of the drops emerging from the base of the cloud is nearly a linear function of the height attained. The time for the precipitation to appear, on the other hand, is an inverse function of the upward air velocity. Experimental observations of rain from non-freezing clouds have distinguished two main types. The first of these shows an increase in drop diameter or rainfall intensity downward through the cloud, as would be expected if the drops followed a variety of trajectories within the cloud. The second type is one in which the drop trajectories tend to coincide, in which case there would be a maximum in the raindrop density and the rain water content at some defined height within the cloud. This has been verified qualitatively by radar observations and flight experiments.

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

Nucleation and initial growth of Pd2Si crystals on Si(111)

1993 ◽  
Vol 51 ◽  
pp. 844-845
Author(s):  
Xianghong Tong ◽  
Oliver Pohland ◽  
J. Murray Gibson
Keyword(s):  
High Vacuum ◽  
Dark Field ◽  
Ultra High Vacuum ◽  
Initial Growth ◽  
Surface And Interface ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Initial Stage ◽  
Effect Of Surface

The nucleation and initial stage of Pd2Si crystals on Si(111) surface is studied in situ using an Ultra-High Vacuum (UHV) Transmission Electron Microscope (TEM). A modified JEOL 200CX TEM is used for the study. The Si(111) sample is prepared by chemical thinning and is cleaned inside the UHV chamber with base pressure of 1x10−9 τ. A Pd film of 20 Å thick is deposited on to the Si(111) sample in situ using a built-in mini evaporator. This room temperature deposited Pd film is thermally annealed subsequently to form Pd2Si crystals. Surface sensitive dark field imaging is used for the study to reveal the effect of surface and interface steps.The initial growth of the Pd2Si has three stages: nucleation, growth of the nuclei and coalescence of the nuclei. Our experiments shows that the nucleation of the Pd2Si crystal occurs randomly and almost instantaneously on the terraces upon thermal annealing or electron irradiation.

Sign in / Sign up

Export Citation Format

Share Document