DIFFUSION TEXTURE GROWTH OF Bi-Pb-Sr-Ca-Cu-O SUPERCONDUCTORS

1991 ◽  
Vol 05 (27) ◽  
pp. 1817-1827 ◽  
Author(s):  
N.X. TAN ◽  
A.J. BOURDILLON ◽  
W.H. TSAI
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Liquid Phase ◽  
Thick Fiber ◽  
Platelet Morphology ◽  
Gravitational Pull ◽  
Kinetics Of ◽  
Scanning Electron

Typically, Bi-Sr-Ca-Cu-O superconductors have a peculiar crystal platelet morphology caused by preferred orientations during crystal growth. Aligned platelets can be formed by reaction between Pb-Bi-O and a ceramic precursor, such as SrCaCu2O4+y. The alignment is due to gravitational pull on the liquid phase during sintering. The processing, microstructure and superconducting transport properties of these aligned BSCCO materials have been characterized. Scanning electron microscopy shows that thick, fiber-textured, films grow in single domains. Zero resistivity at 100 K was observed in a textured specimen sintered for 100 hours. With differential thermal analysis, the flux action of lead, which accelerates the kinetics of Bi 2 Sr 2 Ca 2 Cu 3 O 10+y formation, is understood.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

scholarly journals Preparation and Properties of Thick Film Resistors Containing Cadmium Glasses and Cadmium Oxide

1980 ◽  
Vol 7 (1-3) ◽  
pp. 29-33
Author(s):  
R. Kužel ◽  
J. Broukal
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Electrical Properties ◽  
Cadmium Oxide ◽  
X Ray Diffraction ◽  
Temperature Coefficient Of Resistance ◽  
X Ray ◽  
Scanning Electron

The electrical properties of resistors comprising finely divided CdO and cadmium glass, were investigated. The change in a temperature coefficient of resistance from about −500 ppm/℃ to +70 ppm/℃ was realized by addition of a further component to the resistor paste. Differential thermal analysis, X-ray diffraction analysis and scanning electron microscopy were used for studying crystalline phases in glass containing CdO.

Microstructure Similarities between Phases F and U in Al-Pd-Co Alloys

2016 ◽  
Vol 258 ◽  
pp. 440-443
Author(s):  
Ivona Černičková ◽  
Marek Adamech ◽  
Libor Ďuriška ◽  
Marian Drienovský ◽  
Dusan Janičkovič ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Energy Dispersive ◽  
Eutectoid Transformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Alloys ◽  
Scanning Electron

The work is aimed at searching for compositionally variant isostructural mutations of the cubic F-phase in both as-annealed (850°C/500 h) and DTA-cooled conditions of the Al72Pd9Co19 alloy. Recently, the mutations were reported for the U-phase in the Al69.8Pd13.8Co16.4 alloy annealed at 700°C for 2000 h. In the investigation, scanning electron microscopy including energy dispersive X-ray spectroscopy, powder X-ray diffraction, and differential thermal analysis (DTA) were used. Two isostructural mutations of the F-phase, FL (the product of L-parent) and FV (the product of V-parent), were identified (symbol L stands for liquid). On DTA-cooling, the bivariant heterogeneous transition (Lpart→V), the monovariant heterogeneous transformation (Lrest→V+FL), and the monovariant quasi-eutectoid transformation (Vrest→Al5Co2+FV) were recorded.

Alumina (Al2O3) Nanofibers from Electrospinning

2012 ◽  
Vol 476-478 ◽  
pp. 379-382 ◽  
Author(s):  
Delin Lai ◽  
Yong Chen ◽  
Da Xiang Yang ◽  
Wei Ling Guo ◽  
Yu Xi Yu
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Aqueous Solution ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Aluminum Isopropoxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Scanning Electron

The alumina (Al2O3) nanofibers were fabricated by electrospinning a viscous mixture of aluminum isopropoxide solution in 10% aqueous solution of PVA followed by calcination at 500~1000 °C. Tools such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric and differential thermal analysis (TG-DTA) were employed to characterize the obtained nanofibers. When the nanofibers were heat treated at 1000 °C, the as-prepared nanofibers have a diameter in the range of 30 ~ 100 nm, and are composed of α-Al2O3.

The Effects of BaF2 Addition on Melt-Processed YBa2Cu3O7-x Superconductors

2007 ◽  
Vol 546-549 ◽  
pp. 2075-2078
Author(s):  
Jian Qing Feng ◽  
Lian Zhou ◽  
Ya Feng Lu ◽  
Ping Xiang Zhang ◽  
Xiao Yan Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Thermal Behavior ◽  
Decomposition Temperature ◽  
Precursor Powder ◽  
Peritectic Decomposition ◽  
Ybco Superconductors ◽  
Scanning Electron

The effects of BaF2 on thermal behavior and microstructure of melt-processed YBCO superconductors have been investigated. The differential thermal analysis (DTA) results indicated that the peritectic decomposition temperature of YBCO precursor powder was lowered when BaF2 was added (from 1020 to 976). The peritectic decomposition temperature was lowest at the content of 5 wt.% BaF2, and the variation of melting temperature was not significant above 5 wt.% BaF2. The microstructures of the doped samples have been observed by scanning electron microscopy (SEM). The results showed that the of BaF2 microstructure .

Solidification of Al–Cu–Fe alloys forming icosahedral phase

1996 ◽  
Vol 11 (9) ◽  
pp. 2177-2185 ◽  
Author(s):  
B. Grushko ◽  
R. Wittenberg ◽  
D. Holland-Moritz
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Icosahedral Phase ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fe Alloys ◽  
Scanning Electron

The solidification of a series of Al–Cu–Fe alloys containing an icosahedral phase has been studied by scanning electron microscopy, energy-dispersive x-ray spectroscopy, powder x-ray diffraction, and differential thermal analysis. The constitution and morphology of alloys solidified at different rates are presented. The overall compositional range of the icosahedral phase was determined in as-cast, slowly solidified alloys and those annealed at 800 and 600 °C. The solidification of this phase follows closely the Al3Fe–AlCu compositional direction. The first icosahedral phase solidified close to Al65.5Cu21.5Fe13; its compositional region at 800 °C lies between about Al64.5Cu23Fe12.5 and Al62Cu26.5Fe11.5, while at 600 °C it lies between Al62Cu26.5Fe11.5 and Al60.5Cu29.5Fe10. The formation of the icosahedral and related structures observed in Al–Cu–Fe alloys is discussed.

Effects of Nano-Cr2O3 Doping on Properties and Microstructures of Vitrified Bond CBN Grinding Tools

2012 ◽  
Vol 152-154 ◽  
pp. 130-134 ◽  
Author(s):  
Hong Juan Zheng ◽  
Zhi Wei Zhao ◽  
Shao Ling Xia ◽  
Feng Chun Wei ◽  
Lin Qi Zhang
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Differential Thermal Analysis ◽  
Bending Strength ◽  
Dense Structure ◽  
Opposite Change ◽  
Grinding Tool ◽  
Vitrified Bond ◽  
Scanning Electron

Nano-Cr2O3 was added to vitrified bond CBN grinding tools to improve their properties. Effects of nano-Cr2O3 on properties and microstructures of vitrified bond CBN grinding tools were investigated. The samples were characterized by differential thermal analysis (TG-DTA), scanning electron microscopy (SEM) and related detecting techniques. Results show that the refractoriness of vitrified bond firstly decreases and then increases with the addition of nano-Cr2O3, but the fluidity has the opposite change. Compared with basic vitrified bond, the refractoriness and fluidity of vitrified bond (4 wt.% nano-Cr2O3) are reduced by 25°C and increased by 5.4%, respectively. The bending strength of CBN grinding tools can be enhanced obviously with the addition of nano-Cr2O3, and it has the maximum bending strength (59.27MPa) when adding 4 wt.% nano-Cr2O3. SEM result shows that CBN grinding tool has the most dense structure and the least pore when adding 4 wt.% nano-Cr2O3.

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