Journal articles: 'Nucleation mechanism'

1

Chen, Qizhi, Can Sang, Xingfang Wu, and Jun Ke. "Martensitic nucleation mechanism." Science in China Series E: Technological Sciences 40, no. 4 (August 1997): 387–95. http://dx.doi.org/10.1007/bf02919425.

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2

Korhonen, H., S. L. Sihto, V. M. Kerminen, and K. E. J. Lehtinen. "Evaluation of the accuracy of analysis tools for atmospheric new particle formation." Atmospheric Chemistry and Physics 11, no. 7 (April 1, 2011): 3051–66. http://dx.doi.org/10.5194/acp-11-3051-2011.

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Abstract. Several mathematical tools have been developed in recent years to analyze new particle formation rates and to estimate nucleation rates and mechanisms at sub-3 nm sizes from atmospheric aerosol data. Here we evaluate these analysis tools using 1239 numerical nucleation events for which the nucleation mechanism and formation rates were known exactly. The accuracy of the estimates of particle formation rate at 3 nm (J3) showed significant sensitivity to the details of the analysis, i.e. form of equations used and assumptions made about the initial size of nucleating clusters, with the fraction of events within a factor-of-two accuracy ranging from 43–97%. In general, the estimates of the actual nucleation rate at 1.5 nm (J1.5) were less accurate, and even the most accurate analysis set-up estimated only 59% of the events within a factor of two of the simulated mean nucleation rate. The J1.5 estimates were deteriorated mainly by the size dependence of the cluster growth rate below 3 nm, which the analysis tools do not take into account, but also by possible erroneous assumptions about the initial cluster size. The poor estimates of J1.5 can lead to large uncertainties in the nucleation prefactors (i.e. constant P in nucleation equation J1.5 = P × [H2SO4]k). Large uncertainties were found also in the procedures that are used to determine the nucleation mechanism. When applied to individual events, the analysis tools clearly overestimated the number of H2SO4 molecules in a critical cluster for most events, and thus associated them with a wrong nucleation mechanism. However, in some conditions the number of H2SO4 molecules in a critical cluster was underestimated. This indicates that analysis of field data that implies a maximum of 2 H2SO4 molecules in a cluster does not automatically rule out a higher number of molecules in the actual nucleating cluster. Our analysis also suggests that combining data from several new particle formation events to scatter plots of H2SO4 vs formation rates (J1.5 or J3) and determining the slope of the regression line may not give reliable information about the nucleation mechanism. Overall, while the analysis tools for new particle formation are useful for getting order-of-magnitude estimates of parameters related to atmospheric nucleation, one should be very cautious in interpreting the results. It is, for example, possible that the tools may have misdirected our theoretical understanding of the nucleation mechanism.

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Korhonen, H., S. L. Sihto, V. M. Kerminen, and K. E. J. Lehtinen. "Evaluation of the accuracy of analysis tools for atmospheric new particle formation." Atmospheric Chemistry and Physics Discussions 10, no. 11 (November 5, 2010): 26279–317. http://dx.doi.org/10.5194/acpd-10-26279-2010.

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Abstract. Several mathematical tools have been developed in recent years to analyze new particle formation rates and to estimate nucleation rates and mechanisms at sub-3nm sizes from atmospheric aerosol data. Here we evaluate these analysis tools using 1239 numerical nucleation events for which the nucleation mechanism and formation rates were known exactly. The accuracy of the estimates of particle formation rate at 3 nm (J3) showed significant sensitivity to the details of the analysis, i.e. form of equations used and assumptions made about the initial size of nucleating clusters, with the fraction of events within a factor-of-two accuracy ranging from 43–97%. In general, the estimates of the actual nucleation rate at 1.5 nm (J1.5) were less accurate, and even the most accurate analysis set-up estimated only 59% of the events within a factor of two of the simulated mean nucleation rate. The J1.5 estimates were deteriorated mainly by the size dependence of the cluster growth rate below 3 nm, which the analysis tools do not take into account, but also by possible erroneous assumptions about the initial cluster size. The poor estimates of J1.5 can lead to large uncertainties in the nucleation prefactors (i.e. constant P in nucleation equation J1.5 = P × [H2SO4]k). Large uncertainties were found also in the procedures that are used to determine the nucleation mechanism. When applied to individual events, the analysis tools clearly overestimated the number of H2SO4 molecules in a critical cluster for most events, and thus associated them with a wrong nucleation mechanism. However, in some conditions the number of H2SO4 molecules in a critical cluster was underestimated. This indicates that analysis of field data that implies a maximum of 2 H2SO4 molecules in a cluster does not automatically rule out a higher number of molecules in the actual nucleating cluster. Our analysis also suggests that combining data from several new particle formation events to scatter plots of H2SO4 vs. formation rates (J1.5 or J3) and determining the slope of the regression line may not give reliable information about the nucleation mechanism.

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4

Sankaran, A., Emmanuel Bouzy, Matthew R. Barnett, and Alain Hazotte. "Grain Boundary-Dependent Selection Criteria for Nucleation of Gamma-Massive Grains in TiAl-Based Alloys." Materials Science Forum 654-656 (June 2010): 2338–41. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.2338.

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Rapid cooling of TiAl-based alloy from α phase (disordered hexagonal, A3) generates  phase (ordered tetragonal, L1o) grains through massive transformation nucleating mostly over the α/α grain boundaries. This current work deals with the identification and the validation of different nucleation mechanisms during  massive transformation in TiAl-based alloys. Special attention has been given to the variant selection criteria for the nucleation of the massive structures along different types of α/α grain boundaries. The  massive domains formed along the grain boundaries were analysed using high resolution electron backscattered diffraction (EBSD). Statistical studies were made on different nucleation sites and different mechanisms are proposed. Two–dimensional studies of the nucleation mechanism suggest that the minimization of the interfacial energy could be the predominant criteria during the grain boundary nucleation. In order to verify this nucleation criterion in three-dimensions, serial sections were made and EBSD maps were taken and analysed in each section. The variant selection observed during the nucleation and the growth of the  massive grains is further discussed after getting a broader view under three-dimensional investigations.

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5

MONETTE, L. "SPINODAL NUCLEATION." International Journal of Modern Physics B 08, no. 11n12 (May 30, 1994): 1417–527. http://dx.doi.org/10.1142/s0217979294000646.

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The aim of this paper is to present the theoretical foundations of spinodal nucleation, by reviewing key theoretical and numerical work. The basic ideas of classical nucleation theory are first presented: the classical droplet model, and the Becker-Döring theory, as these concepts are important to the development of the field theoretical formulation of nucleation. The field theoretical framework for classical nucleation is exposed in some detail, followed by the presentation of a similar framework, extended to nucleation in the proximity of a spinodal (non-classical nucleation), in the presence of long-range Ising interactions. The non-classical nucleating droplet is found to be diffuse, hence to strongly depart from the classical prediction of a compact object with a well-defined surface. The fact that the non-classical nucleating droplet is identified with a ramified object prompts the development of an appropriate cluster description. The basic principles of percolation theory are outlined, and some lattice percolation models introduced. The Kastaleyn-Fortuin mapping, which establishes a connection between a particular percolation model and a limit of the Potts model, is briefly described. This mapping is crucial to the development of a second mapping (Coniglio-Klein) of the Ising spinodal point into a percolation model, where the long-range Ising interactions are translated into a long-range connectivity in the appropriate percolation model. The final result consists of the most powerful tool available to identify precisely the non-classical nucleating droplet in numerical simulations of nucleation in proximity of a spinodal. Numerical simulation results are presented, which support the field theoretical formulation of non-classical nucleation. As the numerical results seem to support the fact that the non-classical nucleating droplet is also a percolation cluster, its fractal structure is investigated by considering the mean-field regime of the percolation model, i.e. a percolation model with long-range connectivity. This leads to an apparent contradiction between the field theory and the mean-field percolation model predictions concerning the mass (or density) scaling of the nucleating droplet. This inconsistency is resolved by postulating that the mean-field percolation clusters cannot be non-classical nucleating droplets, and proposing that the non-classical nucleating droplet is in fact the result of a coalescence of many such clusters. Finally, the calculation of the static prefactor in the nucleation rate by assuming a Becker-Döring dynamics for the coalescence mechanism is outlined. The result is found to be consistent with the predictions of the field theory for the static prefactor. Numerical results are also presented in support of the hypothesized coalescence mechanism.

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6

Akchurin, Marat, Ruslan Zakalyukin, and Alexander Kaminskii. "Twinning mechanism of nucleation." physica status solidi (c) 10, no. 6 (May 6, 2013): 921–25. http://dx.doi.org/10.1002/pssc.201300024.

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7

Ning, An, Ling Liu, Lin Ji, and Xiuhui Zhang. "Molecular-level nucleation mechanism of iodic acid and methanesulfonic acid." Atmospheric Chemistry and Physics 22, no. 9 (May 10, 2022): 6103–14. http://dx.doi.org/10.5194/acp-22-6103-2022.

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Abstract. Both iodic acid (HIO3, IA) and methanesulfonic acid (CH3S(O)2OH, MSA) have been identified by field studies as important precursors of new particle formation (NPF) in marine areas. However, the mechanism of NPF in which IA and MSA are jointly involved is still unclear. Hence, we investigated the IA-MSA nucleation system under different atmospheric conditions and uncovered the corresponding nucleating mechanism at the molecular level for the first time, using a quantum chemical approach and Atmospheric Cluster Dynamics Code (ACDC). The findings show that the pure-IA nucleation rate was much lower than the results of CLOUD (Cosmics Leaving Outdoor Droplets) experiments. MSA can promote IA cluster formation through stabilizing IA via both hydrogen and halogen bonds, especially under conditions with lower temperatures, sparse IA, and rich MSA. However, the nucleation rate of the IA-MSA mechanism is much lower than that of field observations, indicating that the effect of additional nucleation precursors needs to be considered (e.g., H2SO4, HIO2, NH3, and amines). The IA-MSA nucleation mechanism revealed in this study may help to gain insight into the joint effect of marine sulfur- and iodine-containing components on marine NPF.

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8

Baht, Gurpreet S., Jason O'Young, Antonia Borovina, Hong Chen, Coralee E. Tye, Mikko Karttunen, Gilles A. Lajoie, Graeme K. Hunter, and Harvey A. Goldberg. "Phosphorylation of Ser136 is critical for potent bone sialoprotein-mediated nucleation of hydroxyapatite crystals." Biochemical Journal 428, no. 3 (May 27, 2010): 385–95. http://dx.doi.org/10.1042/bj20091864.

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Acidic phosphoproteins of mineralized tissues such as bone and dentin are believed to play important roles in HA (hydroxyapatite) nucleation and growth. BSP (bone sialoprotein) is the most potent known nucleator of HA, an activity that is thought to be dependent on phosphorylation of the protein. The present study identifies the role phosphate groups play in mineral formation. Recombinant BSP and peptides corresponding to residues 1–100 and 133–205 of the rat sequence were phosphorylated with CK2 (protein kinase CK2). Phosphorylation increased the nucleating activity of BSP and BSP-(133–205), but not BSP-(1–100). MS analysis revealed that the major site phosphorylated within BSP-(133–205) was Ser136, a site adjacent to the series of contiguous glutamate residues previously implicated in HA nucleation. The critical role of phosphorylated Ser136 in HA nucleation was confirmed by site-directed mutagenesis and functional analyses. Furthermore, peptides corresponding to the 133–148 sequence of rat BSP were synthesized with or without a phosphate group on Ser136. As expected, the phosphopeptide was a more potent nucleator. The mechanism of nucleation was investigated using molecular-dynamics simulations analysing BSP-(133–148) interacting with the {100} crystal face of HA. Both phosphorylated and non-phosphorylated sequences adsorbed to HA in extended conformations with alternating residues in contact with and facing away from the crystal face. However, this alternating-residue pattern was more pronounced when Ser136 was phosphorylated. These studies demonstrate a critical role for Ser136 phosphorylation in BSP-mediated HA nucleation and identify a unique mode of interaction between the nucleating site of the protein and the {100} face of HA.

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9

Dráber, Pavel, and Eduarda Dráberová. "Dysregulation of Microtubule Nucleating Proteins in Cancer Cells." Cancers 13, no. 22 (November 11, 2021): 5638. http://dx.doi.org/10.3390/cancers13225638.

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In cells, microtubules typically nucleate from microtubule organizing centers, such as centrosomes. γ-Tubulin, which forms multiprotein complexes, is essential for nucleation. The γ-tubulin ring complex (γ-TuRC) is an efficient microtubule nucleator that requires additional centrosomal proteins for its activation and targeting. Evidence suggests that there is a dysfunction of centrosomal microtubule nucleation in cancer cells. Despite decades of molecular analysis of γ-TuRC and its interacting factors, the mechanisms of microtubule nucleation in normal and cancer cells remains obscure. Here, we review recent work on the high-resolution structure of γ-TuRC, which brings new insight into the mechanism of microtubule nucleation. We discuss the effects of γ-TuRC protein dysregulation on cancer cell behavior and new compounds targeting γ-tubulin. Drugs inhibiting γ-TuRC functions could represent an alternative to microtubule targeting agents in cancer chemotherapy.

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10

Suzuki, Tetsuro. "Nucleation Mechanism of the Martensite." Materials Transactions, JIM 32, no. 2 (1991): 114–21. http://dx.doi.org/10.2320/matertrans1989.32.114.

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11

Han, Sang Soo, Kyung Sub Lee, and Hyuck Mo Lee. "Nucleation mechanism of carbon nanotube." Chemical Physics Letters 383, no. 3-4 (January 2004): 321–25. http://dx.doi.org/10.1016/j.cplett.2003.11.033.

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12

Haage, T., J. Zegenhagen, H. U. Habermeier, and M. Cardona. "Nucleation Mechanism ofYBa2Cu3O7−δonSrTiO3(001)." Physical Review Letters 80, no. 19 (May 11, 1998): 4225–28. http://dx.doi.org/10.1103/physrevlett.80.4225.

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13

Barradas, R. G., and B. R. Hollebone. "Piezoelectric nucleation mechanism in electrocrystallisation." Journal of Electroanalytical Chemistry and Interfacial Electrochemistry 217, no. 1 (January 1987): 209–12. http://dx.doi.org/10.1016/0022-0728(87)85075-1.

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14

Salvalaglio, Matteo, Marco Mazzotti, and Michele Parrinello. "Urea homogeneous nucleation mechanism is solvent dependent." Faraday Discussions 179 (2015): 291–307. http://dx.doi.org/10.1039/c4fd00235k.

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The composition of the mother phase plays a primary role in crystallization processes, affecting both crystal nucleation and growth. In this work, the influence of solvents on urea nucleation has been investigated by means of enhanced sampling molecular dynamics simulations. We find that, depending on the solvent, the nucleation process can either follow a single-step or a two-step mechanism. While in methanol and ethanol a single-step nucleation process is favored, in acetonitrile a two-step process emerges as the most likely nucleation pathway. We also find that solvents have a minor impact on polymorphic transitions in the early stages of urea nucleation. The impact of finite size effects on the free energy surfaces is systematically considered and discussed in relation to the simulation setup.

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15

Fan, Zhongyun, and Hua Men. "An Overview on Atomistic Mechanisms of Heterogeneous Nucleation." Metals 12, no. 9 (September 19, 2022): 1547. http://dx.doi.org/10.3390/met12091547.

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Our current understanding of heterogeneous nucleation has been dominated by the classical nucleation theory (CNT) with little progress of significance being made in past 100 years. In recent years under the financial support from EPSRC for the LiME Research Hub, we have made substantial progress on understanding heterogeneous nucleation at atomic level using a combination of molecular dynamics simulations and advanced high-resolution electron microscopy. We found that heterogeneous nucleation proceeds through a three-layer nucleation mechanism to produce a 2D nucleus. The atomistic mechanisms responsible for accommodating lattice misfit are dependent on misfit (f): (1) for systems with small negative misfit (−12.5% < f < 0), misfit is accommodated by dislocation mechanism; (2) for systems with small positive misfit (0 < f < 12.5%), misfit is accommodated by vacancy mechanism; and (3) for systems with large misfit (|f| > 12.5%), misfit is accommodated in two steps: formation of coincidence site lattice during prenucleation to accommodate the major misfit (fcsL) and the residual misfit (fr) is accommodated during heterogeneous nucleation by the dislocation mechanism if the residual misfit is less than 0 or by the vacancy mechanism if the residual misfit is larger than 0. Further analysis suggests that heterogeneous nucleation is spontaneous thus barrierless and deterministic rather than stochastic.

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16

Kang, Jian, Gengsheng Weng, Zhengfang Chen, Jinyao Chen, Ya Cao, Feng Yang, and Ming Xiang. "New understanding in the influence of melt structure and β-nucleating agents on the polymorphic behavior of isotactic polypropylene." RSC Adv. 4, no. 56 (2014): 29514–26. http://dx.doi.org/10.1039/c4ra04231j.

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17

Zhao, Shaolei, Jie Gao, Siyang Ma, Chao Li, Yiming Ma, Yang He, Junbo Gong, Fu Zhou, Bingyuan Zhang, and Weiwei Tang. "Mechanism and Modelling of Reactive Crystallization Process of Lithium Carbonate." Processes 7, no. 5 (April 28, 2019): 248. http://dx.doi.org/10.3390/pr7050248.

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The reactive crystallization of lithium carbonate (Li2CO3) from lithium sulfate (Li2SO4) and sodium carbonate (Na2CO3) solutions is a key process in harvesting solid lithium, whether from ores, brines, or clays. However, the process kinetics and mechanism remain poorly understood and the modelling of the reactive crystallization of Li2CO3 is not available. Hence, this work aims to determine the kinetics and mechanisms of the nucleation and growth of Li2CO3 reactive crystallization by induction time measurements and to model and optimize the crystallization process using response surface methodology. Induction time measurements were carried out as functions of initial supersaturation and temperature using a laser method. It was found that the primary nucleation mechanism of Li2CO3 varies with solution supersaturations, in which, expectedly, the heterogenous nucleation mechanism dominates at low supersaturations while the homogeneous nucleation mode governs at high supersaturations. The transition point between heterogenous and homogenous nucleation was found to vary with temperatures. Growth modes of Li2CO3 crystals were investigated by relating induction time data with various growth mechanisms, revealing a two-dimensional nucleation-mediated growth mechanism. The modelling and optimization of a complex reactive crystallization were performed by response surface methodology (RSM), and the effects of various crystallization parameters on product and process performances were examined. Solution concentration was found to be the critical factor determining the yield of crystallization, while stirring speed was found to play a dominant role in the particle size of Li2CO3 crystals. Our findings may provide a better understanding of the reactive crystallization process of Li2CO3 and are critical in relation to the crystallization design and control of Li2CO3 production from lithium sulfate sources.

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18

Ma, Xin Pei, Guang Xin Li, Jian Feng Yang, and Zhi Hao Jin. "Two Types of Phase Separation and Crystal Nucleation-Growth Mechanisms for Machinable Glass Ceramic." Materials Science Forum 544-545 (May 2007): 929–32. http://dx.doi.org/10.4028/www.scientific.net/msf.544-545.929.

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Machinable mica glass ceramics with more ZnO and B2O3 showed the phase separation by spinodal decomposition. the size of two phases formed by phase separation is in micron meter order. The nucleation and growth of crystal is performed through the diffusion of atoms. Another kind of materials with no ZnO and B2O3 addition behaves different mechanism of phase separation in terms of nucleation and growth. Many fine particles are obtained after the phase separation , the size of which is less than 100nm in diameter. Subsequently nucleation and growth in the crystallization is accomplished by aggregation and unification of the granular phase precipitation. The mechanism of the aggregation and unification nucleation-growth is different from one controlled by atom diffusion in nature. The different mechanisms in crystal nucleation and growth, caused by the composition changing.

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19

Picu, R. C., V. Gupta, and H. J. Frost. "Crack nucleation mechanism in saline ice." Journal of Geophysical Research: Solid Earth 99, B6 (June 10, 1994): 11775–86. http://dx.doi.org/10.1029/94jb00685.

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20

Ohguchi, Koji, Kenji Yasuoka, and Mitsuhiro Matsumoto. "Molecular Mechanism of Vapor-Liquid Nucleation." Progress of Theoretical Physics Supplement 138 (2000): 257–58. http://dx.doi.org/10.1143/ptps.138.257.

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21

Frenklach, Michael, and Alexander M. Mebel. "On the mechanism of soot nucleation." Physical Chemistry Chemical Physics 22, no. 9 (2020): 5314–31. http://dx.doi.org/10.1039/d0cp00116c.

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22

Tkachenko, S. I., V. S. Vorob'ev, and S. P. Malyshenko. "The nucleation mechanism of wire explosion." Journal of Physics D: Applied Physics 37, no. 3 (January 16, 2004): 495–500. http://dx.doi.org/10.1088/0022-3727/37/3/030.

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23

Krauss, W., S. K. Pabi, and H. Gleiter. "On the mechanism of martensite nucleation." Acta Metallurgica 37, no. 1 (January 1989): 25–30. http://dx.doi.org/10.1016/0001-6160(89)90262-9.

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24

Fujita, Hiroshi. "A Mechanism of Nucleation of Crystals." MATERIALS TRANSACTIONS 43, no. 6 (2002): 1306–11. http://dx.doi.org/10.2320/matertrans.43.1306.

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25

Cui, Yuqing, Jelena Stojakovic, Hideomi Kijima, and Allan S. Myerson. "Mechanism of Contact-Induced Heterogeneous Nucleation." Crystal Growth & Design 16, no. 10 (September 20, 2016): 6131–38. http://dx.doi.org/10.1021/acs.cgd.6b01284.

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26

Scheck, Johanna, Lisa M. Fuhrer, Baohu Wu, Markus Drechsler, and Denis Gebauer. "Nucleation of Hematite: A Nonclassical Mechanism." Chemistry – A European Journal 25, no. 56 (September 9, 2019): 13002–7. http://dx.doi.org/10.1002/chem.201902528.

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27

Savvova, O. V. "Effect of nucleation mechanism on the structure of polyfunctional calcium phosphate glass materials." Functional materials 21, no. 4 (December 30, 2014): 421–26. http://dx.doi.org/10.15407/fm21.04.421.

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28

Zhang, Kangjing, and Zhaobin Qiu. "Effect of Cyanuric Acid as an Efficient Nucleating Agent on the Crystallization of Novel Biodegradable Branched Poly(Ethylene Succinate)." Macromol 1, no. 2 (April 7, 2021): 112–20. http://dx.doi.org/10.3390/macromol1020009.

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Novel biodegradable branched poly(ethylene succinate) (b-PES) composites, i.e., nucleated b-PES samples, were prepared by incorporating low loadings of cyanuric acid (CA) through a solution and casting method to enhance the crystallization rate. As an efficient nucleating agent, CA could remarkably increase the nonisothermal melt crystallization peak temperature, shorten the crystallization half-time, accelerate the overall isothermal melt crystallization, and enhance the nucleation density of b-PES spherulites in the composites. Despite the addition of CA, the crystallization mechanism and crystal structure of b-PES remained unchanged. A possible epitaxial crystallization mechanism may account for the nucleation of b-PES crystals induced by CA.

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David, Robert O., Jonas Fahrni, Claudia Marcolli, Fabian Mahrt, Dominik Brühwiler, and Zamin A. Kanji. "The role of contact angle and pore width on pore condensation and freezing." Atmospheric Chemistry and Physics 20, no. 15 (August 12, 2020): 9419–40. http://dx.doi.org/10.5194/acp-20-9419-2020.

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Abstract. It has recently been shown that pore condensation and freezing (PCF) is a mechanism responsible for ice formation under cirrus cloud conditions. PCF is defined as the condensation of liquid water in narrow capillaries below water saturation due to the inverse Kelvin effect, followed by either heterogeneous or homogeneous nucleation depending on the temperature regime and presence of an ice-nucleating active site. By using sol–gel synthesized silica with well-defined pore diameters, morphology and distinct chemical surface-functionalization, the role of the water–silica contact angle and pore width on PCF is investigated. We find that for the pore diameters (2.2–9.2 nm) and water contact angles (15–78∘) covered in this study, our results reveal that the water contact angle plays an important role in predicting the humidity required for pore filling, while the pore diameter determines the ability of pore water to freeze. For T>235 K and below water saturation, pore diameters and water contact angles were not able to predict the freezing ability of the particles, suggesting an absence of active sites; thus ice nucleation did not proceed via a PCF mechanism. Rather, the ice-nucleating ability of the particles depended solely on chemical functionalization. Therefore, parameterizations for the ice-nucleating abilities of particles in cirrus conditions should differ from parameterizations at mixed-phase clouds conditions. Our results support PCF as the atmospherically relevant ice nucleation mechanism below water saturation when porous surfaces are encountered in the troposphere.

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Ma, Jun, Xiaotian Zhao, Wei Liu, Yang Li, Long Liu, Yuhang Song, Yuanhua Xie, Xinguo Zhao, and Zhidong Zhang. "Coercivity Mechanism and Magnetization Reversal in Anisotropic Ce-(Y)-Pr-Fe-B Films." Materials 14, no. 16 (August 19, 2021): 4680. http://dx.doi.org/10.3390/ma14164680.

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In this study, the magnetic properties, coercivity mechanism, and magnetization reversal process were investigated for Ce-(Y)-Pr-Fe-B films. After the addition of Y and subsequent heating treatment, the formations of REO (RE ≡ Ce and Pr) and REFe2 (RE ≡ rare earths) phases are inhibited, and the microstructure of Ce-Y-Pr-Fe-B film is optimized. Meanwhile, the coercivity and the squareness of the hysteresis loop are significantly improved. The coercivity mechanism of Ce-Y-Pr-Fe-B film is determined to be a mixture of nucleation and pinning mechanisms, but dominated by the nucleation mechanism. The demagnetization results show that the nucleation of reversal magnetic domains leads to irreversible reversal. Our results are helpful to understand the coercivity mechanism and magnetization reversal of permanent magnetic films with multi-main phases.

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Vorontsova, Maria A., Dominique Maes, and Peter G. Vekilov. "Recent advances in the understanding of two-step nucleation of protein crystals." Faraday Discussions 179 (2015): 27–40. http://dx.doi.org/10.1039/c4fd00217b.

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The two-step mechanism of nucleation of crystals in solutions posits that the formation of crystal nuclei occurs within structures of extended lifetimes, in which the nucleating solute is at high concentration. The validity of this mechanism has been demonstrated for proteins, small-molecule organic and inorganic materials, colloids, and polymers. Due to large molecule sizes, proteins are an ideal system to study the details of this nucleation pathway, in particular the formation mechanisms of the nucleation precursors and the associated physico-chemical rules. The precursors of protein crystal nuclei are protein-rich clusters of sizes ∼100 nm that contain 10 000–100 000 molecules and occupy less than 10⁻³of the total solution volume. Here we demonstrate, using oblique illumination microscopy, the liquid nature of the clusters of the protein lysozyme and reveal their inhomogeneous structure. We test a hypothesis put forth by theory that clusters primarily consist of transient protein oligomers. For this, we explore how varying the strength of the Coulomb interaction affects the cluster characteristics. We find that the cluster’s size is insensitive to variations of pH and ionic strength. In contrast, the addition of urea, a chaotropic agent that leads to protein unfolding, strongly decreases the cluster size. Shear stress, a known protein denaturant, induced by bubbling of the solutions with an inert gas, elicits a similar response. These observations support partial protein unfolding, followed by dimerization, as the mechanism of cluster formation. The amide hydrogen–deuterium exchange, monitored by nuclear magnetic resonance, highlights that lysozyme conformational flexibility is a condition for the formation of the protein-rich clusters and facilitates the nucleation of protein crystals.

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32

Sun, Cui, and Zhang. "Homogeneous Nucleation Mechanism of NaCl in Aqueous Solutions." Crystals 10, no. 2 (February 12, 2020): 107. http://dx.doi.org/10.3390/cryst10020107.

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In this study, molecular dynamic simulations are employed to investigate the homogeneous nucleation mechanism of NaCl crystal in solutions. According to the simulations, the dissolved behaviors of NaCl in water are dependent on ion concentrations. With increasing NaCl concentrations, the dissolved Na+ and Cl- ions tend to be aggregated in solutions. In combination with our recent studies, the aggregate of dissolved solutes is mainly ascribed to the hydrophobic interactions. Different from the two-step mechanism, no barrier is needed to overcome the formation of the aggregate. In comparison with the classical nucleation theory (CNT), because of the formation of solute aggregate, this lowers the barrier height of nucleation and affects the nucleation mechanism of NaCl crystal in water.

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33

Chandra, A., Y. Huang, Z. Q. Jiang, K. X. Hu, and G. Fu. "A Model of Crack Nucleation in Layered Electronic Assemblies Under Thermal Cycling." Journal of Electronic Packaging 122, no. 3 (November 5, 1999): 220–26. http://dx.doi.org/10.1115/1.1286100.

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A model for crack nucleation in layered electronic assemblies under thermal cycling is developed in this paper. The present model includes three scales: (i) at the microscale or the mechanism level, the damage mechanisms such as diffusive void growth or fatigue cracks, determine the damage growth rate; (2) at an intermediate mesoscale, the localized damage bands are modeled as variable stiffness springs connecting undamaged materials; and (iii) at the macroscale or the continuum level, the localized damage band growing in an otherwise undamaged material is modeled as an array of dislocations. The three scales are then combined together to incorporate damage mechanisms into continuum analysis. Traditional fracture mechanics provides a crack propagation model based on pre-existing cracks. The present work provides an approach for predicting crack nucleation. The proposed model is then utilized to investigate crack nucleations in three-layered electronic assemblies under thermal cycling. The damage is observed to accumulate rapidly in the weakest regions of the band. Estimates are obtained for critical time or critical number of cycles at which a macroscopic crack will nucleate in these assemblies under thermal cycling. This critical number of cycles is found to be insensitive to the size of the damage cluster, but decreases rapidly as the local excess damage increases. [S1043-7398(00)00503-X]

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Zhang, Xiao, and Xin Xing Zhou. "Evaluation of Foaming and Nucleation and Growth Mechanism of Soy-Based Polyurethane Foams." Materials Science Forum 913 (February 2018): 738–45. http://dx.doi.org/10.4028/www.scientific.net/msf.913.738.

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The foaming and nucleation and growth mechanism of soybean oil-based polyurethane (SPU) were determined by the degree of hydrogen bonding, and isocyanate groups. New types of SPU were prepared by the different NCO/OH molar ratio (isocyanate index) from 1.0 to 2.0 in a soy polyol/polyether polyol (MDI) system. Foaming and nucleation and growth mechanisms of SPU were studied by fluorescence microscope (FM), scanning electron microscope (SEM), energy disperse spectroscopy (EDS) and Fourier transform infrared spectroscopy (FT-IR). It indicated that the isocyanate index affected remarkably the velocity of foaming and the critical nucleation radius of SPU and the ester functional group increased with the increase of isocyanate index. The nucleation and growth phase transition were dominated by the diffusion controlled nucleation and isocyanate content was the key factor of foam formation.

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Urushihara, Tsuyoshi, Kiyoka Okada, Kaori Watanabe, Akihiko Toda, Etsuo Tobita, Naoshi Kawamoto, and Masamichi Hikosaka. "Acceleration Mechanism of Nucleation of Polymers by Nano-sizing of Nucleating Agent." Polymer Journal 39, no. 1 (December 7, 2006): 55–64. http://dx.doi.org/10.1295/polymj.pj2006040.

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Urushihara, Tsuyoshi, Kiyoka Okada, Kaori Watanabe, Akihiko Toda, Naoshi Kawamoto, and Masamichi Hikosaka. "Acceleration Mechanism in Critical Nucleation of Polymers by Epitaxy of Nucleating Agent." Polymer Journal 41, no. 3 (2009): 228–36. http://dx.doi.org/10.1295/polymj.pj2008116.

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Okada, Kiyoka, Kaori Watanabe, Tsuyoshi Urushihara, Akihiko Toda, and Masamichi Hikosaka. "Role of epitaxy of nucleating agent (NA) in nucleation mechanism of polymers." Polymer 48, no. 1 (January 2007): 401–8. http://dx.doi.org/10.1016/j.polymer.2006.10.048.

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Hernandez, D., Beatriz López, and J. M. Rodriguez-Ibabe. "Ferrite Grain Size Refinement in Vanadium Microalloyed Structural Steels." Materials Science Forum 500-501 (November 2005): 411–18. http://dx.doi.org/10.4028/www.scientific.net/msf.500-501.411.

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The addition of small quantities of vanadium in structural steels produces a significant refinement in the final ferrite microstructure. There are two different mechanisms contributing to refinement: enhancement of grain boundary ferrite nucleation and intragranular nucleation. The contribution of each mechanism depends on the vanadium content and heat treatment of the steel. In this study the contribution of both refining mechanisms has been evaluated for two V-microalloyed steels subjected to different heat treatments. The results confirm that this refinement is based on the enhancement of ferrite nucleation through particle-stimulated nucleation mechanisms, while other aspects, as the influence of vanadium slowing down the austenite-ferrite transformation kinetics, seem to exert a minor effect.

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Linse, Sara. "Mechanism of amyloid protein aggregation and the role of inhibitors." Pure and Applied Chemistry 91, no. 2 (February 25, 2019): 211–29. http://dx.doi.org/10.1515/pac-2018-1017.

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Abstract Inhibition of amyloid β peptide (Aβ) aggregation is an important goal due to the connection of this process with Alzheimer’s disease. Traditionally, inhibitors were developed with an aim to retard the overall macroscopic aggregation. However, recent advances imply that approaches based on mechanistic insights may be more powerful. In such approaches, the microscopic steps underlying the aggregation process are identified, and it is established which of these step(s) lead to neurotoxicity. Inhibitors are then derived to specifically target steps involved in toxicity. The Aβ aggregation process is composed of at minimum three microscopic steps: primary nucleation of monomers only, secondary nucleation of monomers on fibril surface, and elongation of fibrils by monomer addition. The vast majority of toxic species are generated from the secondary nucleation process: this may be a key process to inhibit in order to limit toxicity. Inhibition of primary nucleation, which delays the emergence of toxic species without affecting their total concentration, may also be effective. Inhibition of elongation may instead increase the toxicity over time. Here we briefly review findings regarding secondary nucleation of Aβ, its dominance over primary nucleation, and attempts to derive inhibitors that specifically target secondary nucleation with an aim to limit toxicity.

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Blumenstein, R., W. Finnegan, and L. Grant. "Ice Nucleation Silver Iodide-Sodium Iodide: A Reevaluation." Journal of Weather Modification 15, no. 1 (October 20, 2012): 11–15. http://dx.doi.org/10.54782/jwm.v15i1.74.

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New, preliminary, laboratory studies of the 2Agl.Nal ice nucleus are being conducted in the CSU Isothermal Cloud Chamber. Rates and mechanisms of ice nucleation are investigated using chemical kinetic methodology. Interrelationships between ice nuclei effectiveness, rates and mechanisms of nucleation, and chemical composition are studied. The use of chemical kinetics in the study of ice nucleation is described by DeMott, et al. (1983). The 2Agl.Nal hygroscopic aerosol nucleates the ice phase by a condensation freezing process. This process is sensitive to supersaturation with respect to water. When water supersaturation is increased to a still unknown but critical value, the rate of nucleation increases, the mechanism of nucleation changes, and the effectivity increases significantly. The results have utility in cloud modification.

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Umo, Nsikanabasi Silas, Robert Wagner, Romy Ullrich, Alexei Kiselev, Harald Saathoff, Peter G. Weidler, Daniel J. Cziczo, Thomas Leisner, and Ottmar Möhler. "Enhanced ice nucleation activity of coal fly ash aerosol particles initiated by ice-filled pores." Atmospheric Chemistry and Physics 19, no. 13 (July 10, 2019): 8783–800. http://dx.doi.org/10.5194/acp-19-8783-2019.

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Abstract. Ice-nucleating particles (INPs), which are precursors for ice formation in clouds, can alter the microphysical and optical properties of clouds, thereby impacting the cloud lifetimes and hydrological cycles. However, the mechanisms with which these INPs nucleate ice when exposed to different atmospheric conditions are still unclear for some particles. Recently, some INPs with pores or permanent surface defects of regular or irregular geometries have been reported to initiate ice formation at cirrus temperatures via the liquid phase in a two-step process, involving the condensation and freezing of supercooled water inside these pores. This mechanism has therefore been labelled pore condensation and freezing (PCF). The PCF mechanism allows formation and stabilization of ice germs in the particle without the formation of macroscopic ice. Coal fly ash (CFA) aerosol particles are known to nucleate ice in the immersion freezing mode and may play a significant role in cloud formation. In our current ice nucleation experiments with a particular CFA sample (CFA_UK), which we conducted in the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) aerosol and cloud simulation chamber at the Karlsruhe Institute of Technology (KIT), Germany, we observed a strong increase (at a threshold relative humidity with respect to ice of 101 %–105 %) in the ice-active fraction for experiments performed at temperatures just below the homogeneous freezing of pure water. This observed strong increase in the ice-active fraction could be related to the PCF mechanism. To further investigate the potential of CFA particles undergoing the PCF mechanism, we performed a series of temperature-cycling experiments in AIDA. The temperature-cycling experiments involve exposing CFA particles to lower temperatures (down to ∼228 K), then warming them up to higher temperatures (238–273 K) before investigating their ice nucleation properties. For the first time, we report the enhancement of the ice nucleation activity of the CFA particles for temperatures up to 263 K, from which we conclude that it is most likely due to the PCF mechanism. This indicates that ice germs formed in the CFA particles' pores during cooling remain in the pores during warming and induce ice crystallization as soon as the pre-activated particles experience ice-supersaturated conditions at higher temperatures; hence, these pre-activated particles show an enhancement in their ice-nucleating ability compared with the scenario where the CFA particles are directly probed at higher temperatures without temporary cooling. The enhancement in the ice nucleation ability showed a positive correlation with the specific surface area and porosity of the particles. On the one hand, the PCF mechanism can play a significant role in mixed-phase cloud formation in a case where the CFA particles are injected from higher altitudes and then transported to lower altitudes after being exposed to lower temperatures. On the other hand, the PCF mechanism could be the prevalent nucleation mode for ice formation at cirrus temperatures rather than the previously acclaimed deposition mode.

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Men, Hua, and Zhongyun Fan. "Heterogeneous Nucleation Mechanisms in Systems with Large Lattice Misfit Demonstrated by the Pb(l)/Cu(s) System." Metals 12, no. 10 (September 23, 2022): 1583. http://dx.doi.org/10.3390/met12101583.

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Our current understanding of heterogeneous nucleation has been largely confined to the classical nucleation theory (CNT) that was postulated over 100 years ago based on a thermodynamic approach. Further advances in heterogeneous nucleation research requires detailed knowledge of atomistic activities at the liquid/substrate interface. In this work, using a classical molecular dynamics (MD) simulation, we investigated the atomistic mechanisms of heterogeneous nucleation in systems with a large lattice misfit (|f| > 12.5%) demonstrated by the liquid Pb and solid Cu system (denoted as the Pb(l)/Cu(s) system) with a misfit of 27.3%. We found that heterogeneous nucleation in systems with a large misfit takes place in two distinctive steps: (1) Prenucleation creates a coincidence site lattice (CSL) on the substrate surface to accommodate the majority (fcsl) of the initial misfit (f) and (2) Heterogeneous nucleation accommodates the residual misfit fr (fr = misfit − fcsl) at the nucleation temperature to create a plane of the new solid phase (a two-dimensional (2D) nucleus) through either a three-layer dislocation mechanism if fr < 0 or a three-layer vacancy mechanism if fr > 0, such as in the case of the Pb(l)/Cu(s) system.

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Hauptmann, Marc, Steven Brems, Elisabeth Camerotto, Paul W. Mertens, Marc M. Heyns, Stefan de Gendt, Christ Glorieux, and Walter Lauriks. "Stroboscopic Schlieren Study of Bubble Formation during Megasonic Agitation." Solid State Phenomena 187 (April 2012): 185–89. http://dx.doi.org/10.4028/www.scientific.net/ssp.187.185.

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An important problem in megasonic cleaning is the nucleation process of bubbles, which act as the cleaning agents. A fundamental understanding of this nucleation process will help to optimize the cleaning parameters for future applications to achieve damage free cleaning. In this work, we use quantitative stroboscopic Schlieren imaging to study the interaction of nucleating bubbles with a travelling acoustic wave. The advantage of this method is that it is non-interfering, meaning that it does not disturb the bubble nucleation. It is revealed that nucleation mechanism is a 2 step process, where a regime of slow bubble growth due to rectified diffusion is subsequently followed by a transient cavitation cycle, where bubbles grow explosively. The latter is accompanied by broadband acoustic emission and enhanced thermal dissipation, leading to the occurrence of thermal convection visible in the Schlieren images.

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Li, Yutang, Linzhu Wang, Chaoyi Chen, Shufeng Yang, and Xiang Li. "New Insights into the Mechanism of Nucleation of ZrO2 Inclusions at High Temperature." Materials 15, no. 22 (November 10, 2022): 7960. http://dx.doi.org/10.3390/ma15227960.

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It is difficult to observe the nucleation mechanism of inclusions in real-time. In this study, the nucleation process of zirconium oxide inclusions was systematically studied by classical nucleation theory and first principles. Zr deoxidized steel with 100 ppm Zr addition was processed into metallographic samples for scanning electron microscopy energy-dispersive spectroscopy observation. The electrolytic sample was analyzed by micro X-ray diffraction and transmission electron microscopy, and the zirconium oxide in the sample was determined to be ZrO2. The nucleation rate and radius of the ZrO2 inclusions were calculated by classical nucleation theory, and they were compared with the experimental values. There was a considerable difference between the experimental and theoretical values of the nucleation rate. The effect of the nucleation size was analyzed by first-principles calculation, and the thermodynamic properties of ZrO2 clusters and nanoparticles were analyzed by constructing (ZrO2)n (n = 1–6) clusters. The thermodynamic properties of ZrO2 calculated by first principles were consistent with the values in the literature. Based on two-step nucleation theory, the nucleation pathway of ZrO2 is as follows: Zratom + Oatom → (ZrO2)n → (ZrO2)2 → core (ZrO2 particle)–shell ((ZrO2)2 cluster) nanoparticle → (ZrO2)bulk.

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45

Liu, Wei, and Hideki Nariai. "Ultrahigh CHF Prediction for Subcooled Flow Boiling Based on Homogenous Nucleation Mechanism." Journal of Heat Transfer 127, no. 2 (February 1, 2005): 149–58. http://dx.doi.org/10.1115/1.1844536.

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Homogeneous nucleation, although being discounted as a mechanism for vapor formation for water in most conditions, is found to possibly occur under some extreme conditions in subcooled flow boiling. Under the conditions, vapor bubbles of molecular dimensions generated in the superheated liquid adjacent to channel wall from homogeneous nucleation due to the local temperature exceeds homogeneous nucleation temperature. The condition is called in this paper as homogeneous nucleation governed condition. Under the condition, conventional flow pattern for subcooled flow boiling, which is characterized by the existence of Net Vapor Generation (NVG) point and the followed bubble detachment, movement and coalescence processes, cannot be established. Critical heat flux (CHF) triggering mechanism so far proposed, which employs a premise assumption that the conventional flow pattern has been established, such as liquid sublayer dryout model, is no more appropriate for the homogeneous nucleation governed condition. In this paper, first, the existence of the homogeneous nucleation governed condition is indicated. In the following, a criterion is developed to judge a given working condition as the conventional one or the homogeneous nucleation governed one. With the criterion, subcooled flow boiling data are categorized and typical homogeneous nucleation governed datasets are listed. The homogeneous nucleation governed data are characterized by extreme working parameters, such as ultrahigh mass flux, ultralow ratio of heated length to channel diameter L/D or ultrahigh pressure. CHF triggering mechanism for the homogeneous nucleation governed condition is proposed and verified. Parametric trends of the CHF, in terms of mass flux, pressure, inlet subcooling, channel diameter, and the ratio of heated length to diameter are also studied.

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Shi, Wen Min, Jing Liu, and Chang Yi Li. "The Recrystallization Behavior Study of 3%Si Nonoriented Electrical Steel." Advanced Materials Research 535-537 (June 2012): 678–86. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.678.

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The recrystallization behavior of the cold rolled 3%Si nonoriented electrical steel at different temperatures is investigated by OIM(Orientation Imaging Microscopy). The results show that the recrystallization process and texture of 3%Si nonoriented electrical steel at different temperatures are determinated by different recrystallization mechanisms. At low annealing temperatures, the formation of recrystallization texture in this specimen can be explained by the mechanism of oriented nucleation theory, but at higher annealing temperatures, the formation of recrystallization texture in this specimen can be explained by the mechanism of oriented growth theory, the twin nucleation mechanism may penetrate the whole recrystallization process.

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Rusen, Edina, Aurel Diacon, and Alexandra Mocanu. "Photonic crystals obtained by soap-free emulsion terpolymerization." Open Chemistry 12, no. 1 (January 1, 2014): 126–30. http://dx.doi.org/10.2478/s11532-013-0356-7.

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AbstractThis paper presents the use of soap-free emulsion terpolymerization to obtainphotonic crystals (PCs). Monodisperse latexes resulted from the polymerization of styrene (ST) with 2-hydroxyethyl methacrylate (HEMA) and acrylic acid (AA) at different compositions defined as system A, B and C respectively. The water solubility of the macroradicals determined different nucleation mechanisms in all three cases. The micellar nucleation mechanism was more predominant for generating system A, whereas the homogeneous nucleation was specific for system C. For system B, both nucleation mechanisms werepossible with the same probability. The latexes and the resulted PCs were characterized by optical microscopy (OM), dynamic light scattering (DLS), gel permeation chromatography (GPC) and UV-VIS spectroscopy.

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Verbeken, Kim, and Leo Kestens. "Nucleation of Secondary Recrystallization in Ultra Low Carbon Steel." Materials Science Forum 495-497 (September 2005): 1189–94. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.1189.

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The nucleation stage of secondary recrystallization has never been considered in detail. During the present study, nucleation of abnormal grain growth in ULC steel was studied. A specific nucleation mechanism was identified. This mechanism involved the disappearance of low angle grain boundaries, which gave rise to the onset of a local grain coalescence mechanism that clusters grains that were only separated by low angle grain boundaries. The impact of the nucleation stage remained visible in the texture that was obtained after complete abnormal grain growth.

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Yu, Li Bin, Qi Jun Zhong, Yi Xiao, Jian Feng Gu, and Qing Dong Zhong. "Kinetics of Ni-Nano Cr₂O₃ Composite Coating during Early Electro-Crystallization Processes." Advanced Materials Research 785-786 (September 2013): 938–43. http://dx.doi.org/10.4028/www.scientific.net/amr.785-786.938.

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Nucleation kinetics of Ni-nanoCr2O3composite coating during early electro-crystallization was investigated. The results showed that, the early electro-crystallization processes of Ni-nanoCr2O3composite coating and pure Ni coating followed a Scharifker-Hill nucleation/growth mechanism. At the low potential, the nucleation process of pure Ni and Ni-Cr2O3composite system may approach to the progressive nucleation model; With the overpotential increasing, the nucleation model of Pure Ni and Ni-Cr2O3composite system converts into the instantaneous nucleation mechanism controlled; at the same overpotential, Cr2O3powder promotes the electro-crystallization nucleation of Ni. But at high negative potential, Cr2O3powder in composite system promotes the electro-crystal nucleation of Ni weakly; the nanoCr2O3powder added reduces the current efficiency in the nucleation process of Ni.

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Yu, F., and R. Turco. "The size-dependent charge fraction of sub-3-nm particles as a key diagnostic of competitive nucleation mechanisms under atmospheric conditions." Atmospheric Chemistry and Physics Discussions 11, no. 4 (April 12, 2011): 11281–309. http://dx.doi.org/10.5194/acpd-11-11281-2011.

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Abstract. A clear physical understanding of atmospheric particle nucleation mechanisms is critical in assessing the influences of aerosols on climate and climate variability. Currently, several mechanisms have been proposed and are being employed to interpret field observations of nucleation events. Roughly speaking, the two most likely candidates are neutral cluster nucleation (NCN) and ion-mediated nucleation (IMN). Detailed nucleation event data has been obtained in boreal forests. In one set of analyses of these measurements, NCN was suggested as the dominant formation mode, while in another, it was IMN. Obviously, information on the electrical charge distribution carried by the nucleating clusters themselves is the key to identifying the relative contributions of neutral and ion-mediated processes under various conditions. Fortunately, ground-breaking measurements of the charged states or fractions of ambient nanometer-sized particles soon after undergoing nucleation are now available to help resolve the main pathway. In the present study, the size-dependent "apparent" formation rates and fractions of charged and neutral particles are simulated with a detailed kinetic model. We show that the predicted "apparent" formation rates of charged and neutral particles at 2 nm agree well with the corresponding values derived from the boreal forest data, but the "apparent" contribution of ion-based nucleation increases by up to ~ one order of magnitude as the size of particles decreases from 2 nm to ~1.5 nm. It appears that most of the neutral particles detected at sizes around 2 nm are in reality initially formed on ionic cores that are neutralized before the particles grow to this size. Thus, although the apparent rate of formation of neutral 2-nm particles might seem to be dominated by a neutral clustering process, in fact those particles are largely the result of an ion-induced nucleation mechanism. This point is clarified when the formation rates of smaller particles (e.g., ~1.5 nm) are explicitly analyzed (noting that measurements at these smaller sizes are not yet available), showing that IMN dominates NCN processes under typical circumstances in the boreal forest.

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Journal articles on the topic 'Nucleation mechanism'

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