scholarly journals Comparative Study of ZnO Nanostructures Grown on Variously Orientated GaN and AlxGa1−xN: The Role of Polarization, and Surface Pits

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 663 ◽  
Author(s):  
Zhiyuan Gao ◽  
Liwei Lu ◽  
Xiaowei Xue ◽  
Jiangjiang Li ◽  
Lihuan Zhao ◽  
...  
Keyword(s):  
Kinetic Effect ◽  
Zno Nanowire ◽  
Self Organized ◽  
Nucleation Sites ◽  
Vertically Aligned ◽  
Polarized Surface ◽  
Kinetic Effects ◽  
Semipolar Gan ◽  
Nonpolar Gan

Through comparing ZnO directly grown on the substrates of a-plane, c-plane, and (11-22) plane GaN and AlxGa1−xN (0.06 ≤ x ≤ 1), the roles of different factors that may influence growth have been studied. Seeded by surface pits, ZnO nanowire (NW) preferentially grew along the polarized direction on top of the nonpolar GaN (laterally aligned), polar GaN and AlGaN (vertically aligned), and semipolar GaN (obliquely upward aligned). Nanosheets were easily formed when the polarized surface of the AlGaN film was not intact. The kinetic effect of polarization must be considered to explain the high aspect ratio of NWs along the polarized direction. It was found that dislocation affected NW growth through the surface pits, which provided excellent nucleation sites. If the surface pits on GaN could be controlled to distribute uniformly, self-organized ZnO NW array could be controllably and directly grown on GaN. Moreover, surface pits could also seed for nanosheet growth in AlN, since Al(OH)4− would presumably bind to the Zn2+ terminated surface and suppress the kinetic effects of polarization.

Self-Organized Metal Oxide Exhibiting Enhanced Bioactivity

2006 ◽  
Vol 53 ◽  
pp. 17-21
Author(s):  
Robert L. Karlinsey ◽  
Anderson T. Hara ◽  
Clif W. Duhn
Keyword(s):  
Self Assembly ◽  
Salt Content ◽  
Crystal Formation ◽  
Nucleation Kinetics ◽  
Self Organized ◽  
Nucleation Sites ◽  
Organization Process ◽  
Prior Hypothesis ◽  
Supersaturated Solutions

Self-assembled niobium oxide microcones produced by potentiostatic anodization with varied NaF content (between 100 and 250 mg) in an HF electrolyte are shown to nucleate mineral when immersed in supersaturated solutions emulating mineral content in saliva and blood. The most extensive mineral coverage in 100 mL of 2.5 wt. % HF electrolyte occurs when NaF content is about 100 mg with substantial mineral formation occurring within 24 hours. Higher salt content apparently alters the conditions favoring mineral nucleation by generating smaller nucleation centers that ultimately diminish the extent of mineral coverage. Additionally, nucleation kinetics and morphological contrasts between mineral formed from saliva and blood is briefly discussed in terms of the relative degree of supersaturation with respect to hydroxyapatite. Finally, we show that the integrity of the microcone shape is not critical for mineral nucleation, an observation that builds on our prior hypothesis by promoting the importance of self-assembly and crystal formation. Based on these results, we demonstrate the influence of NaF and stress the role of the self-organization process in producing effective mineral nucleation sites.

The role of asymmetric excitation in self-organized nanostructure formation upon femtosecond laser ablation

2011 ◽  
Vol 104 (3) ◽  
pp. 969-973 ◽  
Author(s):  
Juergen Reif ◽  
Olga Varlamova ◽  
Sergej Varlamov ◽  
Michael Bestehorn
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Femtosecond Laser Ablation ◽  
Nanostructure Formation ◽  
Self Organized

The Growth Mechanism of Vertically Aligned ZnO Nanowire Arrays on Non-epitaxial Si(100) Substrates

2011 ◽  
Vol 58 (6) ◽  
pp. 817-821 ◽  
Author(s):  
Yu-Tung Yin ◽  
Yen-Zhi Chen ◽  
Ching-Hsiang Chen ◽  
Liang-Yih Chen
Keyword(s):  
Growth Mechanism ◽  
Nanowire Arrays ◽  
Zno Nanowire ◽  
Zno Nanowire Arrays ◽  
Vertically Aligned

The Role of Self-Organized Reaction Rates in the Micro-Kinetic Description of Electrocatalytic Reactions

2021 ◽  
Vol MA2021-01 (48) ◽  
pp. 1952-1952
Author(s):  
Alfredo Calderón Cárdenas ◽  
Enrique Adalberto Paredes Salazar ◽  
Hamilton Varela
Keyword(s):  
Reaction Rates ◽  
Kinetic Description ◽  
Self Organized ◽  
Electrocatalytic Reactions

Decisive role of dopants in the optical properties of vertically aligned silicon nanowires prepared by metal-assist chemical etching

2021 ◽  
Vol 121 ◽  
pp. 111632
Author(s):  
Le Thanh Cong ◽  
Nguyen Thi Ngoc Lam ◽  
Doan Van Thuong ◽  
Ngo Ngoc Ha ◽  
Nguyen Duc Dung ◽  
...  
Keyword(s):  
Optical Properties ◽  
Silicon Nanowires ◽  
Chemical Etching ◽  
Decisive Role ◽  
Vertically Aligned

Pendidikan Bagi Generasi Emas Indonesia Abad 21: Sebuah Agenda Perubahan Paradigmatik

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Daniel Mohammad Rosyid ◽  
Masroro Lilik Ekowanti
Keyword(s):  
Value System ◽  
National Education ◽  
Digital Era ◽  
Self Organized ◽  
National Education System ◽  
The Social ◽  
Customized Learning ◽  
Society Today

 If the social phenomenon is a reflection of nature's thought, our culture and value system, then the multidimensional crisis afflicting our society today requires us to re-examine our educational philosophy and practice at least the past 40 years.  We suffer all the bad influences of industrialization as part of the colonial process, precisely because we adopt the most advanced instrument, namely, mass schooling system with an obsession for quality-based standard as the magic spell. In this digital era, the effort of liberating society from the colonial, pioneer of independence as a condition of the proclamation of independence was a reform of the national education system. We should be scheduled deschooling society. This agenda includes the following: the paradigmatic shift from the school system to learning webs based Self Organized Learning Environment (SOLE); mass schooling to individualized, customized learning; of relevance to quality; of technical competence to the independence of the soul or creativity. This reform was way back on the three pillars of education philosophy of Ki Hajar Dewantara: family, community, and College. New demands upon the role of the teacher in the 21st century is changing.

scholarly journals Ma Kahana ka ‘Ike: Lessons for Community-Based Fisheries Management

2018 ◽  
Vol 10 (10) ◽  
pp. 3799 ◽  
Author(s):  
Monica Montgomery ◽  
Mehana Vaughan
Keyword(s):  
Fisheries Management ◽  
Local Governance ◽  
Local Level ◽  
Hawaiian Island ◽  
Institutional Fit ◽  
Human Environment ◽  
Self Organized ◽  
Governance Systems ◽  
Changing Role

Indigenous and place-based communities worldwide have self-organized to develop effective local-level institutions to conserve biocultural diversity. How communities maintain and adapt these institutions over time offers lessons for fostering more balanced human–environment relationships—an increasingly critical need as centralized governance systems struggle to manage declining fisheries. In this study, we focus on one long-enduring case of local level fisheries management, in Kahana, on the most populated Hawaiian island of O‘ahu. We used a mixed-methods approach including in-depth interviews, archival research, and participation in community gatherings to understand how relationships with place and local governance have endured despite changes in land and sea tenure, and what lessons this case offers for other communities engaged in restoring local-level governance. We detail the changing role of konohiki (head fishermen) in modern times (1850–1965) when they were managing local fisheries, not just for local subsistence but for larger commercial harvests. We also highlight ways in which families are reclaiming their role as caretakers following decades of state mismanagement. Considerations for fisheries co-management emerging from this research include the importance of (1) understanding historical contexts for enhancing institutional fit, (2) enduring community leadership, (3) balancing rights and responsibilities, and (4) fostering community ability to manage coastal resources through both formal and informal processes.

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