scholarly journals Microstructural Analysis of Silica Fume Concrete with Scanning Electron Microscopy and X-Ray Diffraction

2020 ◽  
Vol 10 (3) ◽  
pp. 5845-5850
Author(s):  
B. Uzbas ◽  
A. C. Aydin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Hydroxide ◽  
Silica Fume ◽  
Hardened Cement ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mechanical And Microstructural Properties ◽  
Scanning Electron

The effects of using different ratios of silica fume on the mechanical and microstructural properties of hardened cement paste and concrete were investigated in this study. Portland cement was replaced with 5%, 10%, 15%, and 20% silica fume (SF) by weight. Microstructural properties of obtained samples were investigated by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD analysis showed that the ratio of calcium hydroxide (CH), which is produced by hydration, decreases depending on the concrete age and the amount of silica fume. The SEM analysis showed that the use of silica fume decreases gaps and calcium silicate hydrate (C-S-H) which is also a hydration production. Silica fume content of up to 15% improved the observed mechanical and microstructural properties of concrete. At the optimum value of 15%, improvement in the paste was observed due to the filler effect and the reaction between the silica fume and calcium hydroxide, leading to a reduction in calcium hydroxide in the concrete.

Synthesis of Ca(OH)2 Nanoparticles Aqueous Suspensions and Interaction with Silica Fume

2012 ◽  
Vol 629 ◽  
pp. 482-487 ◽  
Author(s):  
V. Daniele ◽  
G. Taglieri ◽  
A. Gregori
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silica Fume ◽  
Calcium Silicate Hydrate ◽  
Thermal Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrate Phase ◽  
Work Interaction ◽  
Scanning Electron

In this work, interaction at ambient temperature between silica fume and artificially produced Ca(OH)2 nanoparticles by two different methods was analyzed. Initial products and formed hydrated phases were characterized by several investigations including X-ray diffraction, thermal analyses, transmission and scanning electron microscopy. Synthesized Ca(OH)2 nanoparticles appeared regularly shaped and hexagonally plated, with side dimensions from 200nm to less than 20nm. Characterization analyses showed that, by reducing particles dimensions, calcium silicate hydrate phase formation was evident already after 7 day of hydration and a nearly complete consuming of free Ca(OH)2 after 28 days was observed. Besides, formed hydrate phases showed a highly wrinkled layer with marked crumple and rough-edge surfaces.

Thermal Expansion of Cu-Ga-Sn Alloys

2014 ◽  
Vol 353 ◽  
pp. 137-142
Author(s):  
V.A. Bykov ◽  
T.V. Kulikova ◽  
K.Yu. Shunyaev ◽  
A.B. Shubin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Thermal Expansion ◽  
Temperature Dependence ◽  
Linear Thermal Expansion ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
Tin Alloys ◽  
X Ray ◽  
Scanning Electron

The thermal and microstructural properties of five copper-gallium-tin alloys (Cu-Ga-Sn) and two important intermetallic compounds Cu3Sn and CuGa2 have been investigated by dilatometry, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction. The temperature dependence of thermal expansion and coefficient of linear thermal expansion (CLTE) were obtained.

Influence of Silica Fume/Nanosilica on the Strength and Microstructure of Phosphoaluminate Cement

2011 ◽  
Vol 291-294 ◽  
pp. 1447-1449
Author(s):  
Chen Jing Lv ◽  
Shu Xia Ren ◽  
Xiu Shu Tian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silica Fume ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
Hydration Time ◽  
X Ray ◽  
Hydration Rate ◽  
Splitting Strength ◽  
Scanning Electron

The influence of Silica fume/Nanosilica on the Performance of phosphoaluminate cement was studied in the paper. The microstructure and morphology was determined by X-ray diffraction and scanning electron microscopy. The experimental results show that the phosphoaluminate cement with 4% of added Silica fume/Nanosilica(1:1) by weight of cement has an optimum splitting strength, in which the increase of splitting strength are about 15.1%,11.8% and 24.6% at 3days,7days and 28 days. The reason for causing the above results are the hydration rate and the amount of the hydrates of PALC with 4% Silica fume/Nanosilica have been increased significantly at different hydration time because of the role played by Silica fume and Nanosilica together.

Investigation of Sulphate Attack on C-S-H Gel

2011 ◽  
Vol 287-290 ◽  
pp. 1116-1120
Author(s):  
Xiao Xin Feng ◽  
Xiu Juan Li ◽  
Qing Min Wei
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hardened Cement ◽  
Sulphate Attack ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Hardened Cement Paste ◽  
X Ray ◽  
High Concentration Solution ◽  
Scanning Electron

C-S-H gel was prepared by extracting from the hardened cement paste, and was immersed in Na2SO4 solution and MgSO4 solution respectively. The microstructure of the C-S-H gel attacked by sulphate was observed by means of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. It is found that C-S-H gel is attacked by both Na2SO4 and MgSO4, and gypsum forms whether in low or high concentration solution of Na2SO4 and MgSO4.

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.

scholarly journals Analytical study of Buddha sculptures in Jingyin temple of Taiyuan, China

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaojian Bai ◽  
Chen Jia ◽  
Zhigen Chen ◽  
Yuxuan Gong ◽  
Huwei Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Analytical Study ◽  
Energy Dispersive Spectrometry ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Ancient China ◽  
X Ray ◽  
Unique Style ◽  
Scanning Electron

AbstractWith exquisite design and unique style, the painted sculptures of Tutang Buddha and two attendants Buddha in Jingyin Temple are precious cultural heritages of China. The sculpture of Tutang Buddha, which was carved from a mound and painted by ancient craftsmen, was rarely found in ancient China. However, due to natural and human factors, the sculptures were severely damaged. Obviously, they require urgent and appropriate protection and restoration. In this study, samples taken from the sculptures were analysed through multiple analytical techniques, including scanning electron microscopy with energy dispersive spectrometry (SEM–EDS), Raman spectroscopy, X-ray diffraction (XRD), optical microscopy (OM) and granulometry. The analysis results enable us to infer the techniques used by the craftsmen in making the sculptures and provide a reliable evidence for the conservation and future protection of these and similar sculptures.

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