Dendritic array growth in the systems NH4Cl–H2O and [CH2CN]2–H2O: steady state measurements and analysis

Hansen, G. P.; Liu, Shan; Lu, Shu-Zu; Hellawell, A.

doi:10.1016/s0022-0248(01)01679-7

Cited by 38 publications

(20 citation statements)

References 14 publications

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“…The order of magnitude experimentally obtained in our work is perfectly consistent with such values but a quite large dispersion is noticeable since values vary from 0.0045 to 0.0096 which roughly corresponds to 0.007 ± 0.002. The data of table 1 are represented in figure 4 to analyse the effect of pulling rate on tip radius; these data are compared to theoretical radius coming from marginal stability theories [21] and usually verified experimentally in case of diffusive directional growth [4,8] : (6) with V*~ 0.02, stability constant m = -1.38 K/wt%, liquidus slope * = 6. …”

Section: Resultsmentioning

confidence: 99%

“…In situ determinations are more reliable so that such studies have been conducted on some special organic systems that are analogous to metallic systems in term of solidification behavior but have the great interest of being transparent to visible light. For directional solidification, studies have been carried out with those materials in a configuration where the sample is constrained between two narrowly-spaced plates [4,8,9]. Although very interesting and fruitful, this quasi-2D configuration is neither representative of materials processing nor capable of producing extended 3D solidification patterns [10].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Interferometric method for the analysis of dendrite growth and shape in 3D extended patterns in transparent alloys

Bergeon

Weiss

Mangelinck‐Noël

et al. 2009

Trans Indian Inst Met

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In the frame of the DECLIC project of the French Space Agency (CNES), a specific device dedicated to the in situ and real time observation of directional solidification of transparent systems in 3D configuration has been developed. A method based on interferometric analysis is presented to quantitatively characterize the shape and growth of dendrites so that measurements of critical parameters such as tip radius and growth rate of individual dendrites belonging to extended patterns are enabled. First results obtained on a succinonitrile -0.1 wt% camphor alloy are analysed. The accuracy of measurements and quality of the shape reconstruction are discussed through the comparison of the dendrite contours obtained with different modellings of the dendritic shape (parabolic, parabolic corrected by a 4 th order term, power-law).

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Interferometric method for the analysis of dendrite growth and shape in 3D extended patterns in transparent alloys

Bergeon

Weiss

Mangelinck‐Noël

et al. 2009

Trans Indian Inst Met

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show abstract

“…To begin with, many pure organic materials and their aqueous solutions undergo dendritic crystallization when they are cooled below their liquidus temperatures. Typical examples are ammonium chloride [63], pivalic acid [64], cyclohexanol [62], succinonitrile [54], cholesterol [65], and protein streptavidin [66][67][68]. Under 'lagoon-like' conditions aqueous solutions of potassium cyanide and ammonium hydroxide yield heterogeneous cyanide polymer particles [69].…”

Section: Justificationmentioning

confidence: 99%

On the Origin of Biological Functions

Umantsev¹

2011

JMP

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We consider the problem of structure and functions of the first forms of living matter and present a hypothesis that they were formed through a physico-chemical process known as dendritic crystallization. According to this hypothesis the branching, dendritic structures helped build living systems by lending them functions so that organic chemical evolution is just one natural consequence of the evolution of matter in the universe. We conclude that a self-replicating biological system with adaptation emerged from simple molecules using completely abiotic mechanism of formation, which acted simultaneously or intermittently at different places on the early Earth and created similar structures everywhere. The dendritic hypothesis of origin of the functions explains similarities in the living systems and supports the assumption of a 'second genesis of life'. The dendritic scenario does not need carbon/phosphorus-based solutes in water-based solutions, which may have important implications for exobiology and extraterrestrial origin-of-life scenarios. An experiment to test the hypothesis is suggested.

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“…z A cubic organic glass vessel (120mm×80mm×100mm in inner dimension and 155mm×115mm×135mm in outer dimension), whose temperature can be controlled by circulation liquids in its interlayer; z NH 4 Cl-70wt%H 2 O solution was used for the transparent model alloy, which were prepared from NH 4 Cl with purity of 99.5wt% and de-ionized water, with a liquidus of 34°C [8]; z A nuclei generator with material of aluminum, was cooled by alcohol circulation, the temperature of the sample vessel and the nuclei generator is regulated at 39.7°C and 20.5°C respectively, by two thermostats with an accuracy of ±0.05K; The prepared aluminum substrate were attached to the side surface of the nuclei generator, and immerged into the NH 4 Cl-70wt%H 2 O solution;…”

Section: Nucleation Experimental and Observationsmentioning

confidence: 99%

In-situ observation of nucleation on a rough chilling surface in NH4Cl-H2O solution

Huang

Zhang

Wang

et al. 2009

Trans Indian Inst Met

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The nucleation behaviors of NH 4 Cl crystal on a rough chilling surface immerged in NH 4 Cl-H 2 O solution were investigated. A phenomenon was found that the nuclei are formed periodically on certain spots of the undercooled surface. The relationship between the surface roughness and the nucleation site selection was investigated on abrasive paper polished aluminum substrate, and it is discovered that the number of nucleation sites decreases significantly with the decreasing roughness of the polished substrate. Further nucleation experiments were carried out on chemical etched aluminum substrate with regular micro-patterns, the result shows that the selection of nucleation sites was more sensitive to the micro-patterns rather than the surface roughness of the interface, and the interfaces with sharp nanometer structures were feasible for the nucleation on the interface.

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Dendritic array growth in the systems NH4Cl–H2O and [CH2CN]2–H2O: steady state measurements and analysis

Cited by 38 publications

References 14 publications

Interferometric method for the analysis of dendrite growth and shape in 3D extended patterns in transparent alloys

Interferometric method for the analysis of dendrite growth and shape in 3D extended patterns in transparent alloys

On the Origin of Biological Functions

In-situ observation of nucleation on a rough chilling surface in NH4Cl-H2O solution

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