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.

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.

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.

Growth Mechanism and Characterization of Porous CuS Microspheres

2012 ◽  
Vol 568 ◽  
pp. 348-351
Author(s):  
Shuang Xu ◽  
Nuan Song ◽  
Chang Li Qiu ◽  
Yao Ping Zhang ◽  
Jian Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Mechanism ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

In this paper, a facile method was presented to fabricate CuS porous microspheres, which were formed by the intergrowth of CuS polycrystalline nanoslices. The obtained sample has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electronic diffraction (SAED), and scanning electron microscopy (SEM). On the basis of the experimental results, we proposed a self-assemble mechanism to elucidate the formation of CuS nanoslice structure.

High Sensitivity Electrochemical Multisensors based on Graphene-PANI Nanocomposite for Simultaneous Detection of Glucose and Urea

2016 ◽  
Vol 19 (3) ◽  
pp. 145-150 ◽  
Author(s):  
Meysam Karimi ◽  
Mohammad Rabiee ◽  
Mojgan Abdolrahim ◽  
Mohammadreza Tahriri ◽  
Daryoosh Vashayee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Xrd Analysis ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

We present a study of the effect of graphene–PANI nanocomposites on the sensitivity of the urea and glucose multisensory. We used an electroctrochemical multisensor based on two electrodes located in a reservoir with two separate channels. The urease and glu-cose oxidase (GOD) were employed for detecting the urea and glucose, respectively. We characterized the graphene and graphene-PANI samples with X-ray Diffraction (XRD) analysis and scanning electron microscopy (SEM) observations. We further performed the Cyclic voltammetry and Amperometry tests. The collected experimental results revealed that the intensity of the peak significantly increases with the concentration of the urea and glucose.

scholarly journals Use of chitin as a template for the preparation of mesostructured ZSM-5

Cerâmica ◽  
2018 ◽  
Vol 64 (370) ◽  
pp. 214-218 ◽  
Author(s):  
F. C. Drumm ◽  
J. S. de Oliveira ◽  
M. S. P. Enders ◽  
E. I. Müller ◽  
E. A. Urquieta-González ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Process ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Scanning Electron

Abstract In this work, mesostructured ZSM-5 zeolite was prepared using chitin as a new template to produce mesoporosity. Different amounts of chitin were used for the synthesis of ZSM-5 in order to verify its influence on the formation of mesopores. All samples were prepared by conventional hydrothermal process. For comparison purposes, ZSM-5 zeolite has also been synthesized without a presence of chitin. The samples were characterized by X-ray diffraction, scanning electron microscopy and N2 adsorption techniques. Experimental results showed that the mesopores volume of the obtained samples increased with increasing amount of chitin in the reaction mixture. Therefore, chitin showed to be a promising template for obtaining the ZSM-5 with mesoporous property.

Preparation and Mechanism of Spherical [Ni1/3Co1/3Mn1/3]Ox Precursors for Li [Ni1/3Co1/3Mn1/3]O2 by an Ultrasonic Atomization Method

2013 ◽  
Vol 773 ◽  
pp. 572-579
Author(s):  
Qing Lin Chen ◽  
Xue Wen Liu ◽  
Bao Hua Rong ◽  
Kun Tang ◽  
Hua Zhen Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
Initial Concentration ◽  
X Ray ◽  
Ultrasonic Atomization ◽  
Scanning Electron

The spherical precursors - [Ni1/3Co1/3Mn1/3]Ox and Li [Ni1/3Co1/3Mn1/3]O2 were synthesized by an ultrasonic atomization method via two routes. The [Ni1/3Co1/3Mn1/3]Ox and Li [Ni1/3Co1/3Mn1/3]O2 powders were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results show that the initial concentration of the raw solution would affect the size of precursor [Ni1/3Co1/3Mn1/3]Ox particles. The Li [Ni1/3Co1/3Mn1/3]O2 particles which were prepared from the mixture of LiNO3 and [Ni1/3Co1/3Mn1/3]Ox were much larger than the precursor particles and those prepared from the LiNO3-[Ni1/3Co1/3Mn1/3]Ox may maintain the size of the precursor particles.

Effects of LaCrO3 Composite Additive for the Hydration Resistance of MgO-CaO Refractory

2011 ◽  
Vol 306-307 ◽  
pp. 938-941 ◽  
Author(s):  
Jie Jing Sun ◽  
Chao Nan Yin ◽  
Yong Jie Liu ◽  
Shi Quan Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Temperature ◽  
X Ray Diffraction ◽  
Burning Temperature ◽  
X Ray ◽  
Hydration Rate ◽  
Crystallization Properties ◽  
Hydration Resistance ◽  
Scanning Electron

Effect of different blending amount of LaCrO3, a composite additive, on the hydration resistance and crystallization properties of magnesia-calcium refractory were studied by measuring hydration rate, using X-ray diffraction and scanning electron microscopy. The results show that the LaCrO3at a low addition (≤1%) can significantly decrease the hydration resistance of the MgO-CaO material when the burning temperature is 1550°C, and the hydration rate is only 0.183%. LaCrO3can promote the growth of the CaO, while it has little effect on MgO. The Cr2O3and CaO can melt into CaO·Cr2O3in a high temperature. The CaO·Cr2O3can not only promote sintering but also wrap on the CaO, which is negative for the grain to contact with water, and consequently improve the hydration resistance of magnesia-calcium refractory.

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.

Sign in / Sign up

Export Citation Format

Share Document