Electrodeposition in support: concentration gradients, an ohmic model and the genesis of branching fractals

The technique of paper-supported copper electrodeposition provides examples of well-presented fractal and dense radial structures. The growths may be developed to reveal concentration gradients around the growths at low cell overpotential. Measurements for current and length scale against time, within a mid-range of cell overpotentials, fit an ohmic model of the growth conditions. To examine the relation of growth morphology to the micrometre-scale structure, we grew first at one overpotential and then continued at a lower overpotential. Electron microscope observations of this growth reveal a distinct change in microstructure from irregular to dentritic microcrystalline from the high to low potential respectively. The interface between the growths is a distinctive compact granular deposit. The granular deposit is unstable to branching and dendrite growth.

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The value of Electron Microscope studies of imperfect natural diamonds

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100174102 ◽

1990 ◽

Vol 48 (4) ◽

pp. 194-195

Author(s):

J C Walmsley ◽

A R Lang

Keyword(s):

Electron Microscope ◽

Classification Scheme ◽

Natural Diamond ◽

Sudden Change ◽

Growth Conditions ◽

Diamond Growth ◽

Major Constituent ◽

Natural Diamonds ◽

Type Ia ◽

Platelet Defects

Interest in the defects and impurities in natural diamond, which are found in even the most perfect stone, is driven by the fact that diamond growth occurs at a depth of over 120Km. They display characteristics associated with their origin and their journey through the mantle to the surface of the Earth. An optical classification scheme for diamond exists based largely on the presence and segregation of nitrogen. For example type Ia, which includes 98% of all natural diamonds, contain nitrogen aggregated into small non-paramagnetic clusters and usually contain sub-micrometre platelet defects on {100} planes. Numerous transmission electron microscope (TEM) studies of these platelets and associated features have been made e.g. . Some diamonds, however, contain imperfections and impurities that place them outside this main classification scheme. Two such types are described.First, coated-diamonds which possess gem quality cores enclosed by a rind that is rich in submicrometre sized mineral inclusions. The transition from core to coat is quite sharp indicating a sudden change in growth conditions, Figure 1. As part of a TEM study of the inclusions apatite has been identified as a major constituent of the impurity present in many inclusion cavities, Figure 2.

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The dendrite growth, morphology control and deposition properties of uranium electrorefining

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2021.153110 ◽

2021 ◽

Vol 555 ◽

pp. 153110

Author(s):

Kui Liu ◽

Tan tan ◽

Xuanpu Zhou ◽

Nantao Zheng ◽

Yue Ma ◽

...

Keyword(s):

Morphology Control ◽

Dendrite Growth ◽

Growth Morphology

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Phase-Field Modeling of the Dendrite Growth Morphology with Influence of Solid-Liquid Interface Effects

steel research international ◽

10.1002/srin.201300398 ◽

2014 ◽

Vol 86 (1) ◽

pp. 65-72 ◽

Cited By ~ 9

Author(s):

Joao Rezende ◽

Dieter Senk ◽

Dennis Hüttenmeister

Keyword(s):

Phase Field ◽

Dendrite Growth ◽

Liquid Interface ◽

Growth Morphology ◽

Phase Field Modeling ◽

Field Modeling ◽

Solid Liquid Interface ◽

Solid Liquid ◽

Interface Effects

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Atomic-scale structure and non-stoichiometry of meteoritic hibonite: a transmission electron microscope study

American Mineralogist ◽

10.2138/am-2022-8014 ◽

2021 ◽

Keyword(s):

Electron Microscope ◽

Transmission Electron Microscope ◽

Microscope Study ◽

Electron Microscope Study ◽

Scale Structure ◽

Atomic Scale ◽

Transmission Electron ◽

Transmission Electron Microscope Study ◽

Atomic Scale Structure

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The Photoluminescence Spectra Research of SiC Thin Film under Different Sputtering Powers

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.295.93 ◽

2019 ◽

Vol 295 ◽

pp. 93-97

Author(s):

Chang Zhao ◽

Man Zhao ◽

Su Ye Lv ◽

Qing Jun Liu ◽

Guang Jian Xing

Keyword(s):

Thin Film ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Crystal Morphology ◽

Growth Conditions ◽

Photoluminescence Spectra ◽

Experimental Conditions ◽

Grain Sizes ◽

Power Inputs ◽

Scanning Electron

This study prepared an SiC thin film by using the ratio frequency magnetron sputtering method, investigated the effects of different sputtering powers on the SiC material and analysed the changes in crystal morphology and photoluminescence characteristics caused by changes in the growth conditions used. It was considered that there was 6H-SiC crystal morphologies in the SiC thin film under the experimental conditions prevailing in this study. The SiC morphologies with small grain sizes intermingled and therefore formed anSiC thin film. The analyses of the photoluminescence spectra and Scanning Electron Microscope indicated that the SiC thin film materials with preferable crystal compositions could be prepared under appropriate power inputs.

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Growth morphology of Streptomyces akiyoshiensis in submerged culture: influence of pH, inoculum, and nutrients

Canadian Journal of Microbiology ◽

10.1139/m92-016 ◽

1992 ◽

Vol 38 (2) ◽

pp. 98-103 ◽

Cited By ~ 20

Author(s):

M. A. Glazebrook ◽

L. C. Vining ◽

R. L. White

Keyword(s):

Nitrogen Sources ◽

Growth Conditions ◽

Culture Conditions ◽

Inoculum Size ◽

Clear Correlation ◽

Growth Morphology ◽

Physiological Control ◽

Submerged Cultures ◽

Pellet Formation ◽

Culture Influence

Most media in which the growth of shaken submerged cultures of Streptomyces akiyoshiensis was examined did not support the formation of well-dispersed mycelial suspensions. Investigation of the culture conditions promoting dispersed growth showed the pH of the culture medium to be of critical importance; an initial value of 5.5 minimized aggregation of the mycelium while supporting adequate biomass production. In cultures started at this pH, spore inocula gave better mycelial dispersal than did vegetative inocula; with spore inocula, growth morphology was also less affected by inoculum size. The composition of the nutrient solution influenced the extent of mycelial dispersal; slow growth was often associated with clumping but no clear correlation was observed between pellet formation and the ability of carbon or nitrogen sources to support rapid growth. Increasing the phosphate concentration from 0.5 to 15 mM caused a modest decrease in mycelial aggregation. Conditions promoting a well-dispersed mycelium suitable for studying the physiological control of secondary metabolism also supported the formation of 5-hydroxy-4-oxonorvaline by S. akiyoshiensis. Key words: Streptomyces akiyoshiensis, mycelial aggregation, growth conditions.

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Direct observation of ordering in (GaIn) P

Journal of Materials Research ◽

10.1557/jmr.1988.0406 ◽

1988 ◽

Vol 3 (3) ◽

pp. 406-409 ◽

Cited By ~ 49

Author(s):

S. McKernan ◽

B. C. De Cooman ◽

C. B. Carter ◽

D. P. Bour ◽

J. R. Shealy

Keyword(s):

Electron Microscope ◽

Direct Observation ◽

Vapor Phase ◽

Growth Conditions ◽

Dark Field ◽

Growth Surface ◽

Organometallic Vapor Phase Epitaxy ◽

Planar Defects ◽

Group Iii ◽

Gaas Substrates

Gax In1 − x Pepilayers grown under a range of growth conditions by organometallic vapor phase epitaxy (OMVPE) on GaAs substrates have been studied in the electron microscope. The results show the presence of an ordering of the group III sublattice parallel to some of the {111} planes. Dark-field images directly reveal ordered domains of different orientations that appear not to be perfect, but contain many planar defects parallel to the growth surface.

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