Microstructure of Interface between Zirconia and Veneer Porcelain

2011 ◽  
Vol 492 ◽  
pp. 55-60 ◽  
Author(s):  
Bin Deng ◽  
Hong Chen Liu ◽  
Yuan Fu Yi ◽  
Long Quan Shao ◽  
Kang Lin Hou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Composition ◽  
Glass Composition ◽  
Lattice Structure ◽  
Etching Time ◽  
Interface Bonding ◽  
Transmission Electron ◽  
Bonding Property ◽  
Amorphous Glass ◽  
Tem Transmission Electron Microscopy

To study whether the veneering technique will have an impact on zirconia grain and the bonding type and relationship on interface between zirconia and veneer porcelain. Materials and methods: After sintered, zirconia was annealed for 15 minute to finish the phase transition from m to t.4 types of veneer porcelains were sintered and observed with SEM (scanning electron microscopy) and TEM (transmission electron microscopy). Results: With etching time extending, it appeared that many materials loosed and corrosional pit deepened, enlarged in the veneer porcelain, which made crystallize structure move into veneering surface. Composition of interface mainly was amorphous glass matrix and zirconia. Energy spectrum analysis showed that there was no remnant glass composition in the zirconia side departing from interface. SEM showed that crystal in veneering side did not participate interface bonding. Conclusion: The interface between 4 types of veneer porcelains and zirconia bonded well. Veneering sintering technique didn’t change lattice structure of zirconia, which still was tetragonal structure. The specific bonding property of interface still remained to be analyzed further to determine.

Wet Powder Metallurgy Process for Dispersing Carbon Nanotubes and Fabricating Magnesium Composite

2018 ◽  
Vol 759 ◽  
pp. 86-91 ◽  
Author(s):  
Jiang Tao Hou ◽  
Wen Bo Du ◽  
Zhao Hui Wang ◽  
Xian Du ◽  
Chao Xu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Powder Metallurgy ◽  
Interfacial Interaction ◽  
Interface Bonding ◽  
Transmission Electron ◽  
Powder Metallurgy Process ◽  
Disperse Carbon ◽  
Effective Dispersion ◽  
Metallurgy Process

A wet powder metallurgy (WPM) process was developed to disperse carbon nanotubes (CNTs), and to fabricate the CNTs reinforced Mg matrix (CNTs/Mg) composite. The dispersion effect of CNTs were evaluated by field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS) and high-resolution transmission electron microscopy (HR-TEM), respectively. Results showed that the CNTs were homogeneously dispersed on the surface of Mg powder. Adequate bonding and good interfacial interaction between the CNTs and Mg matrix contributed to the efficient load transferring from the CNTs to Mg matrix under a mechanical force. Furthermore, no brittle MgO was formed on the surface and it was beneficial to improving the adhesion of the CNTs to Mg matrix. With 0.5 wt.% CNTs addition, the CNTs/Mg composite experienced remarkable enhancements in tensile stress of 28% and Young’s modulus of 24%. The reasons responsible for these enhancements are suggested as the effective dispersion of the CNTs and the good interface bonding between the CNTs and Mg matrix.

Direct UHV-TEM Observation of Palladium Clusters on a Silicon Surface

2004 ◽  
Vol 10 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Masaki Takeguchi ◽  
Kazutaka Mitsuishi ◽  
Miyoko Tanaka ◽  
Kazuo Furuya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Layer ◽  
Silicon Surface ◽  
Lattice Structure ◽  
Plan View ◽  
Palladium Clusters ◽  
Transmission Electron ◽  
Pd Clusters

About 1 monolayer of palladium was deposited onto a silicon (111) 7 × 7 surface at a temperature of about 550 K inside an ultrahigh vacuum transmission electron microscope, resulting in formation of Pd2Si nanoislands and a 1 × 1 surface layer. Pd clusters created from an excess of Pd atoms on the 1 × 1 surface layer were directly observed byin situplan view high-resolution transmission electron microscopy. When an objective aperture was introduced so that electron diffractions less than 0.20 nm were filtered out, the lattice structure of the 1 × 1 surface with 0.33 nm spacing and the Pd clusters with a trimer shape were visualized. It was found that image contrast of the 1 × 1 lattice on the specific height terraces disappeared, and thereby an atomic structure of the Pd clusters was clearly observed. The appearance and disappearance of the 1 × 1 lattice was explained by the effect of the kinematical diffraction. It was identified that a Pd cluster was composed of three Pd atoms without a centered Si atom, which is consistent with the model proposed previously. The feature of the Pd clusters stuck at the surface step was also described.

Growth Phenomena of Quantum Dot Structures in the Ingaas System Investigated by Tem Techniques

1999 ◽  
Vol 583 ◽  
Author(s):  
P. Werner
Keyword(s):  
Electron Microscopy ◽  
Lattice Strain ◽  
Lattice Structure ◽  
Imaging Techniques ◽  
High Resolution Electron Microscopy ◽  
3 Dimensional ◽  
Gaas Matrix ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Optical Behavior

AbstractThe contribution is mainly focused on the formation and properties of InGaAs islands (quantum dots, QD) in a GaAs matrix, viz. a system showing properties similar to those of other materials systems. Depending on the growth techniques applied (MBE or MOCVD), the islands/dots differ in size, shape, chemical composition, and lattice strain. These parameters influence strongly the optical properties of QD structures, which might consist of single layers or complex 3-dimensional arrays. To reveal the correlation between the morphology/structure and the optical behavior of such systems different analytical methods are available, more effective in some combined applications. The present paper is mainly focused on the possibilities and limitations of transmission electron microscopy (TEM) to analyze the lattice structure of QDs down to the nm-range. Such TEM investigations imply a general problem: to deconvolute separately information on the QD size, shape (e.g., pyramidal or spherical islands), strain and composition. TEM imaging techniques used for such structural analyses will be described, including conventional diffraction contrast and high-resolution electron microscopy, respective examples of which will be presented. For the chemical analysis energy sensitive techniques (e.g., energy filtered images) are appropriate methods. Applications and limitations of such investigations will be discussed.

Lattice Structure and Electrical Properties of Epitaxial Aluminum on GaAs

1982 ◽  
Vol 18 ◽  
Author(s):  
Fernando ◽  
A. Ponce ◽  
Stephen J. Eglash
Keyword(s):  
Electron Microscopy ◽  
Lattice Structure ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Barrier Heights ◽  
Transmission Electron ◽  
Current Voltage ◽  
Abrupt Interface ◽  
Crystallographic Planes ◽  
The Individual

The crystal structure of aluminum layers grown by molecular beam epitaxy (MBE) on GaAs(100) was studied using high resolution transmission electron microscopy. We obtained cross-sectional images with nearly atomic resolution of the lattice structure at Al-GaAs interfaces. GaAs epitaxial layers were grown at 585 °C and cooled in the ultrahigh vacuum MBE growth chamber prior to aluminum deposition. After the desired substrate temperature had been achieved, aluminum was immediately deposited onto arsenic-rich surfaces at a rate of 1000 Å h−1.Aluminum layers deposited onto substrates at 80 °C exhibit an Al(110)/GaAs(100) epitaxial relationship along an abrupt interface. In some regions of the interface we observed isolated arsenic crystallites which were epitaxial with the GaAs substrate. The current-voltage (I-V) and capacitance-voltage (C–V) characteristics of this material are well behaved. Barrier heights of 0.79 eV and ideality factors of 1.04 were determined from room temperature I–V measurements.For aluminum deposited onto GaAs substrates at 400 °C, evidence of twodimensional nucleation and growth was observed. The resulting pyramid-shaped aluminum crystallites had facets along crystallographic planes. Two epitaxial relationships were observed: Al(100)/GaAs(100) and Al(110)/GaAs(100). We observed 12 Å steps along the Al(100)–GaAs(100) interface. C–V and scanning electron microscopy measurements indicate that the individual aluminum crystallites are electrically and physically separated.

Synthesis and Characterization of CdS Nanoparticles

2013 ◽  
Vol 848 ◽  
pp. 3-6
Author(s):  
Xiao Hui Fan ◽  
Hong Juan Liu ◽  
Yan Ming Chen ◽  
Ting Sun
Keyword(s):  
Electron Microscopy ◽  
Quantum Confinement ◽  
Cadmium Acetate ◽  
Synthesis And Characterization ◽  
Cds Nanoparticles ◽  
Narrow Size Distribution ◽  
Quantum Confinement Effects ◽  
Transmission Electron ◽  
Tem Transmission Electron Microscopy

CdS nanoparticles were synthesized by using PVP (polyvinylpyrrolidone) as macromolecular surfactant, N, N-dimethylformamide as solvent, cadmium acetate and thiourea as precursors. The optical properties and morphologies for the synthesized CdS nanoparticles were characterized by UV-Vis absorption spectroscopy and TEM (transmission electron microscopy) measurements. The results show that PVP could act as a better stabilizer for the formation of CdS nanoparticles in N, N-dimethylformamide. The obtained CdS nanoparticles have spherical morphology and a narrow size distribution. CdS nanoparticles could give an apparent extionic absorption peaks and quantum confinement effects.

scholarly journals Profil Distribusi dan Klirens Pengkontras CT SCAN AuNP-PAMAM G4- NIMOTUZUMAB disimulasikan menggunakan Senyawa 198AuNP-PAMAM G4-NIMOTUZUMAB

2016 ◽  
Vol 18 (01) ◽  
pp. 37-43 ◽  
Author(s):  
Adang H G ◽  
Anung Pujiyanto ◽  
Abdul Mutalib ◽  
Rista A S ◽  
Indrarini L ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Resonance ◽  
Ct Scan ◽  
Sodium Dodecyl ◽  
Resonance Imaging ◽  
Transmission Electron ◽  
Tem Transmission Electron Microscopy ◽  
Sds Sodium Dodecyl Sulphate

Riset nanopartikel emas sebagai senyawa pengkontras CT-Scan telahdimulai sejak 3 tahun lalu di Indonesia. Riset interaksi antibodi monoklonal,khususnya nimotuzumab, dengan reseptor EGFR/HER1 dimulai sejak lima tahun lalu dan telah dimanfaatkan untuk penyiapan senyawa pengkontras MRI (Magnetic Resonance Imaging) spesifik target melalui pelabelan konjugat dendrimer-nimotuzumab dengan radionuklida. Sintesis senyawa AuNP-PAMAM G4-Nimotuzumab untuk diagnosis dan terapi pada kanker paru-paru telah berhasil dilakukan di PTRR dan hasil karakterisasinya dengan menggunakan beberapa metode seperti KCKT (Kromatografi Cair Kinerja Tinggi), SDS (Sodium Dodecyl Sulphate) page elektroforesa dan TEM (Transmission Electron Microscopy) menunjukkan bahwa senyawa yang terbentuk adalah sebagai AuNP-PAMAM G4-Nimotuzumab. Pada penelitian ini telah dilakukan uji pre klinis dari senyawa pengkontras AuNPPAMAM G4-nimotuzumab meliputi uji distribusi dan klirens dengan disimulasikan menggunakan senyawa radioaktiv 198AuNP-PAMAM G4- nimotuzumab. Hasil uji distribusi senyawa 198AuNP-PAMAM G4- nimotuzumab menunjukkan penimbunan pada beberapa organ seperti ginjal, hati dan limpa, sedangkan dari hasil uji klirens diperoleh waktu paruh biologis senyawa tersebut adalah 11.77 hari. Hasil pemeriksaan terhadap urin dengan menggunakan kolom PD-10 (Sephadex G25) menunjukkan bahwa ~ 85 % yang dikeluarkan lewat urin masih berbentuk AuNP-PAMAM G4- Nimotuzumab. Hasil pencitraan dengan alat autoradiography menunjukkan bahwa sampai dengan 48 jam setelah penyuntikan, akumulasi radioaktivitas yang terdeteksi masih terdapat pada hati. 

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