scholarly journals Effect of F Content on the Protection of Melted Magnesium Alloy

2001 ◽  
Vol 71 (3) ◽  
pp. 588-594
Author(s):  
Liping Zhang ◽  
Hongliang Lin ◽  
Huizhu Yang ◽  
An Sun ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Volume Fraction ◽  
Energy Dispersive Spectrometer ◽  
Surface Films ◽  
Az91d Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hfc 134A ◽  
Scanning Electron

The protection of molten AZ91D alloy in the cover gases containing sulfur decomposed by FeS2 and fluorine produced by HFC-134a at 730℃ was investigated in this paper. The surface films were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectrometer (XPS). It is revealed that the cover gases containing sulfur decomposed by FeS2 and fluorine produced by HFC-134a can protect the molten AZ91D alloy well. HFC-134a whose volume fraction is 0.04% -0.1% mixed with gas containing sulfur by adding FeS2 0.5g per 30 minutes and holding the melting temperature at 730℃ for 30 min can protect the molten AZ91D alloy. The bigger the volume fraction of HFC-134a, the better the effect. The protected film is formed of MgO, MgF2 and small amount MgS.

scholarly journals Double Reinforcement of Al–Fe Intermetallic Composites Fabricated by Friction Stir Processing

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1002
Author(s):  
Chunping Huang ◽  
Yang Xia ◽  
Chun Xia ◽  
Fencheng Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Friction Stir Processing ◽  
Volume Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Friction Stir ◽  
Metallurgical Bond ◽  
Aluminum Alloy Surface ◽  
Scanning Electron

A double reinforced layer on an aluminum alloy surface was produced using friction stir processing (FSP) by adding 34CrNiMo6 powder into Al (AA2024) substrate for better wear resistance and gradient transitions. The microstructures of the composites were analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The phase composition was examined by X-ray diffraction (XRD). The results show that the double reinforced layer of the Al13Fe4 intermetallic compound could be successfully fabricated via FSP. The volume fraction of Al13Fe4 in the double reinforced layer was higher than in the single reinforced layer due to adding 34CrNiMo6 powder and reinforced twice, and the Al13Fe4 particles were dispersed more homogeneously in the double reinforced layer. The interfaces between the double and single reinforced layer had a good metallurgical bond. The microhardness of the double reinforcement layer was significantly increased. Compared with the AA2024 substrate, the microhardness of the double and single reinforced layers increased five- (576 HV) and two-fold (254 HV), respectively.

Composition and Microstructure of a Natural Nano-Structure Mineral: Six-Ring Rock

2011 ◽  
Vol 295-297 ◽  
pp. 869-872
Author(s):  
Qing Shan Li ◽  
Xin Wang ◽  
Jun Liu ◽  
Guang Zhong Xing
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectrometer ◽  
The Body ◽  
X Ray Diffraction ◽  
Nano Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Nano Size ◽  
Scanning Electron

Six-ring Rock is widely used as containers of water and additives to produce health care products. In this paper, the composition and microstructure of Six-ring Rock have been investigated by using scanning electron microscopy, energy dispersive spectrometer, transmission electron microscopy, x-ray diffraction and other technologies. Results show that Six-ring Rock is composed of CaMg(CO3)2, SiO2 and KAlSi3O8. Fe atoms exist in CaMg(CO3)2 by replacing Mg atoms. Six-ring Rock shows nano-size lamellar and acerose microstructures on the surface, and nano-size monocrystals in the body. Six-ring Rock is a natural nano structure mineral.

scholarly journals Pengaruh Variasi Kadar CaCO3 terhadap Pertumbuhan Fase Superkonduktor BPSCCO–2212 Menggunakan Metode Pencampuran Basah

2021 ◽  
Vol 2 (1) ◽  
pp. 17-22
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Volume Fraction ◽  
Superconducting Phase ◽  
Maximum Point ◽  
X Ray Diffraction ◽  
X Ray ◽  
Degree Of Orientation ◽  
Mixing Method ◽  
Scanning Electron

This research was conducted to determine the effect of CaCO3 levels on the formation of superconducting phase BPSCCO - 2212 by calculating the level of purity of the phases formed and looking at the microstructure. The variation of CaCO3 was 0.95, 1.00, 1.05 and 1.10 mole using the wet mixing method. The samples were calcined at 800 ° C for 10 hours, and sintered at 820 ° C for 20 hours. Synthesized samples were characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD’s chacterization results show that the level of purity of the formed phases increases with increasing Ca levels with maximum point at BPSCCO-2212/1.10 mole. The highest volume fraction was 79,06% in the BPSCCO-2212/1.10 sample. While the lowest volume fraction was 72.10% in the BPSCCO-2212/0.95 sample. Meanwhile, the highest degree of orientation was 20.59% at BPSCCO-2212/0.95. The lowest degree of orientation was 8.46% at BPSCCO-2212/1.10. SEM’s chacterization results show of all samples have been oriented altought not perfect yet and have relatively little space between slabs (voids).

Effect of PO2 and Ag on the phase formation of the Bi(Pb)-2223 superconductor

1999 ◽  
Vol 14 (5) ◽  
pp. 1695-1706 ◽  
Author(s):  
W. Wong-Ng ◽  
L. P. Cook ◽  
W. Greenwood
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Formation ◽  
Volume Fraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Liquid Samples ◽  
Fraction Mixture ◽  
Precursor Composition ◽  
Scanning Electron

The chemical reactions and the compositional characteristics of liquids which lead to the phase formation of the Bi(Pb)-2223 [(Bi, Pb): Sr: Ca: Cu: O] superconductor have been studied for a precursor composition of Bi1.8Pb0.4Sr2Ca2.2Cu3Ox. The combined techniques of quenching, powder x-ray diffraction, differential thermal/thermogravimetric analysis (DTA/TGA), scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) were used to characterize the subsolidus phases and the presence of liquid. Samples were annealed under purified air and under a volume fraction mixture of 7.5% O2/92.5% Ar. The effects of Ag in both the pure air and the 7.5% O2/92.5% Ar experiments were also studied. Results are discussed with respect to their processing implications.

scholarly journals Pengaruh Variasi Suhu Sintering Menggunakan Metode Pencampuran Basah

2020 ◽  
Vol 1 (2) ◽  
pp. 53-57
Author(s):  
M Muntamijayati ◽  
◽  
Suprihatin Suprihatin ◽  
Yanti Yanti ◽  
Simon Sembiring ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Volume Fraction ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Degree Of Orientation ◽  
Mixing Method ◽  
Scanning Electron

The superconducting material BPSCCO-2212 with doping Pb = 0,2 has been synthesized by the wet mixing method. Calculation is caried out at 800 °C for 10 hours. While sintering is done at 825 °C, 830 °C, 835 °C and 840 °C for 20 hours. The synthesis result were characterized by XRD X-Ray Diffraction) and SEM (Scanning Electron Microscopy). The XRD spectrum analysis results that have been processed using celref, show that in general the samples produced have formed the BPSCCO-2212 phase (indicated the presence of Bi-2212 peaks) and have been oriented (indicated the existence of peaks with h = k = 0, l even number). For the calculation result obtanced the highest volume fraction value at 830 °C sintering temperature with a value FV = 66,97 % and the highest degree of orientation at 825 °C with a value of P = 76,54 %. The results of the SEM photo recorder generally show that the crystals formed are oriented.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

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.

Structural Characterization of Gallbladder Stones Using Energy Dispersive X-ray Spectroscopy and X-ray Diffraction

2018 ◽  
Vol 21 (7) ◽  
pp. 495-500 ◽  
Author(s):  
Hassan A. Almarshad ◽  
Sayed M. Badawy ◽  
Abdalkarem F. Alsharari
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
Major Health Problem ◽  
X Ray ◽  
Gallbladder Stones ◽  
Pure Cholesterol ◽  
Scanning Electron

Aim and Objective: Formation of the gallbladder stones is a common disease and a major health problem. The present study aimed to identify the structures of the most common types of gallbladder stones using X-ray spectroscopic techniques, which provide information about the process of stone formation. Material and Method: Phase and elemental compositions of pure cholesterol and mixed gallstones removed from gallbladders of patients were studied using energy-dispersive X-ray spectroscopy combined with scanning electron microscopy analysis and X-ray diffraction. Results: The crystal structures of gallstones which coincide with standard patterns were confirmed by X-ray diffraction. Plate-like cholesterol crystals with laminar shaped and thin layered structures were clearly observed for gallstone of pure cholesterol by scanning electron microscopy; it also revealed different morphologies from mixed cholesterol stones. Elemental analysis of pure cholesterol and mixed gallstones using energy-dispersive X-ray spectroscopy confirmed the different formation processes of the different types of gallstones. Conclusion: The method of fast and reliable X-ray spectroscopic techniques has numerous advantages over the traditional chemical analysis and other analytical techniques. The results also revealed that the X-ray spectroscopy technique is a promising technique that can aid in understanding the pathogenesis of gallstone disease.

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