• Title/Summary/Keyword: Deposition mechanism

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MOLECULAR DYNAMICS SIMULATION OF THE INTERACTION BETWEEN CLUSTER BEAMS AND SOLID SURFACES

  • Kang, Hee-Jae;Lee, Min-Wha;Whang, Chung-Nam
    • Journal of the Korean Vacuum Society
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    • v.4 no.S2
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    • pp.139-147
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    • 1995
  • The mechanism of the ionized cluster beam deposition has been studied using Molecular Dynamics Simulation. The Embedded Atom Method(EAM) potential were used in the simulation. The impact of a Au95-cluster on Au(100) substrate was studied for the impact energies 0.15-10eV/atom. The dependency of the impact energy of cluster beam was observed. For the cluster energy impact of 10eV per atom, the defects on surface were created and the cluster embedded into substrate as an amorphous state. For the energy of 0.5eV per atom, the defect free homoepitaxial growth was observed and atomic scale nucleation was formated, which are in good agreement with experiment. Thus molecular dynamics simulation is very useful to study the mechanism of the ionized cluster beam deposition.

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Effects of UV ozone annealing on conduction mechanism in Ta2O5 thin films deposited by atomic layer deposition (Atomic layer deposition으로 증착된 Ta2O5 박막의 전도기구에 대한 UV ozone annealing 효과)

  • 엄다일;전인상;노상용;황철성;김형준
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.57-57
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    • 2003
  • High dielectric constant materials (high K) have attracted a great deal of interest because of the dramatic scaling down of DRAM capacitor reaching its physical limit in terms of reduction of thickness. Among high-K materials that can replace silicon dioxide, tantalum pentoxide (Ta2O5) thin film, with their high dielectric constant (∼25) and good step coverage, is the candidate of choice.

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The Deposition of $SnO_2$ Films by Spray Pyrolysis (분무열분해법에 의한 $SnO_2$ 박막의 증착)

  • Kim, Tae-Heui
    • Solar Energy
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    • v.15 no.2
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    • pp.91-99
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    • 1995
  • The influence of deposition parameters on the deposition of $SnO_2$ thin films by spray pyrolysis has been studied. In the case of spray solution with tile concentration of 0.01M, at low deposition temperature the deposition was controlled by surface reaction and portion controlled by mass transfer is increased with increasing deposition temperature to $400^{\circ}C$. Above $400^{\circ}C$, the deposition is controlled by mass transfer at low spray pressure, and by surface reaction at high spray pressure. As the concentration of spray solution increased the deposition rate increased, and in this experiment the deposition depends on the Rideal-Eley mechanism. The deposition rate increased with increasing substrate temperature up to $400^{\circ}C$ and then decreased due to homogeneous nucleation. The thickness of the deposit increased with increasing spray duration, and the adhesion between substrate and deposit was formed physically.

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Effects of puerarin on the Akt signaling pathway in bovine preadipocyte differentiation

  • Yun, Jinyan;Yu, Yongsheng;Zhou, Guoli;Luo, Xiaotong;Jin, Haiguo;Zhao, Yumin;Cao, Yang
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.1
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    • pp.4-11
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    • 2020
  • Objective: Puerarin has the potential of regulating the differentiation of preadipocytes, but its mechanism of action has not yet been elucidated. Adipocytes found in adipose tissue, the main endocrine organ, are the main sites of lipid deposition, and are widely used as a cell model in the study of in vitro fat deposition. This study aimed to investigate the effects of puerarin on adipogenesis in vitro. Methods: Puerarin was added to the culture medium during the process of adipogenesis. The proliferation and differentiation of bovine preadipocytes was measured through cell viability and staining with oil red O. The content of triacylglycerol was measured using a triglyceride assay kit. The mRNA and protein expression levels of adipogenic genes, peroxisome proliferator-activated receptor-γ (PPARγ) and CCAAT/enhancer-binding protein-α, were measured using quantitative real-time polymerase chain reaction and western blotting, respectively. Results: The addition of puerarin significantly increased adipogenesis of bovine preadipocytes and enhanced the mRNA and protein level expression of PPARγ (p<0.01). The expression of P-Akt increased after adipogenic hormonal induction, whereas puerarin significantly increased PPARγ expression by promoting the Akt signaling component, P-Akt. The mechanism of adipogenesis was found to be related to the phosphorylation level of Ser473, which may activate the downstream signaling of the Akt pathway. Conclusion: Puerarin was able to promote the differentiation of preadipocytes and improve fat deposition in cattle. The mechanism of adipogenesis was found to be related to the phosphorylation level of Ser473.

Experimental investigation of blocking mechanism for grouting in water-filled karst conduits

  • Zehua Bu;Zhenhao Xu;Dongdong Pan;Haiyan Li;Jie Liu;Zhaofeng Li
    • Geomechanics and Engineering
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    • v.34 no.2
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    • pp.155-171
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    • 2023
  • Aiming at the grouting treatment of water inflow in karst conduits, a visualized experiment system for conduit-type grouting blocking was developed. Through the improved water supply system and grouting system, and the optimized multisource information monitoring system, the real-time observation of diffusion and deposition of slurry, and the data acquisition of pressure and velocity during the whole process of grouting were realized, which breaks through the problem that the monitoring element is easy to fail due to slurry adhesion in conventional test system. Based on the grouting experiments in static and flowing water, the diffusion and deposition behavior of the quick-setting slurry under different working conditions were analyzed. The temporal and spatial variation behavior of the pressure and velocity were studied, and the blocking mechanism of the grouting were further revealed. The results showed that: (1) Under the flowing water condition, the counter-flow diffusion distance of slurry was negatively correlated with the flow water velocity and the volume ratio of cement and sodium silicate (C-S ratio), and positively correlated with the grouting volume. The slurry deposition thickness was negatively correlated with the flowing water velocity, and positively correlated with the grouting volume and C-S ratio. (2) The pressure increased slowly before blocking of the flowing water and rapidly after blocking in karst conduits. (3) With the continuous progress of grouting, the flowing water velocity decreased slowly first, then significantly, and finally tended to be stable. According to the research results, some engineering recommendations were put forward for the grouting treatment of the conduit-type water inflow disaster, which has been successfully applied in the treatment project of the China Resources Cement (Pingnan) Limestone Mine. This study provided some guidance and reference for the parameter optimization of grouting for the treatment projects of water inflow in karst conduits.

The role of long noncoding RNAs in livestock adipose tissue deposition - A review

  • Wang, Lixue;Xie, Yuhuai;Chen, Wei;Zhang, Yu;Zeng, Yongqing
    • Animal Bioscience
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    • v.34 no.7
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    • pp.1089-1099
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    • 2021
  • With the development of sequencing technology, numerous, long noncoding RNAs (lncRNAs) have been discovered and annotated. Increasing evidence has shown that lncRNAs play an essential role in regulating many biological and pathological processes, especially in cancer. However, there have been few studies on the roles of lncRNAs in livestock production. In animal products, meat quality and lean percentage are vital economic traits closely related to adipose tissue deposition. However, adipose tissue accumulation is also a pivotal contributor to obesity, diabetes, atherosclerosis, and many other diseases, as demonstrated by human studies. In livestock production, the mechanism by which lncRNAs regulate adipose tissue deposition is still unclear. In addition, the phenomenon that different animal species have different adipose tissue accumulation abilities is not well understood. In this review, we summarize the characteristics of lncRNAs and their four functional archetypes and review the current knowledge about lncRNA functions in adipose tissue deposition in livestock species. This review could provide theoretical significance to explore the functional mechanisms of lncRNAs in adipose tissue accumulation in animals.