Immobilization of ASH by Microwave Melting

1992 ◽  
Vol 269 ◽  
Author(s):  
Kazuki Morita ◽  
Vinh Q. Nguyen ◽  
Ron Nakaoka ◽  
John D. Mackenzie

ABSTRACTNon-radioactive ash was immobilized via microwave melting. The ash composed mainly of silica (SiO2), titania (TiO2), calcia (CaO), alumina (Al2O3), and carbon (C). The ash was melted with various additives, such as magnetite (Fe3O4), lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), and boron oxide (B2O3) by using a 2.45 GHz, 750 W microwave oven. Samples with different ash and additive concentrations were melted when subjected to microwave radiation. Ease of melting was dependent on the carbon and magnetite concentrations. Melted samples were characterized by X-ray diffraction and scanning electron microscopy (SEM), and subjected to the Toxicity Characteristic Leaching Procedure in regard to lead (Pb) immobilization. Melted samples with more than 30 wt% additives has an undetectable leaching rate of less than 0.1 ppm of lead for TCLP test, which was found to be due to the reduction and evaporation of the lead during melting. More than 80 % of the lead was lost through evaporation leaving less than 0.1 wt% Pb in the melted glass.

2007 ◽  
Vol 336-338 ◽  
pp. 669-671
Author(s):  
Yan Yi Liu ◽  
Wei Pan

BaTiO3 powder was synthesized from BaCO3 and TiO2 using a domestic microwave oven. The samples were synthesized under different temperatures with various holding times. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to examine the phase compositions and morphologies of the result samples. The main phase obtained at 950°C was BaTiO3, and the intermediate phases Ba2TiO4 and Ba4TiO9 were also detected. The pure, well-crystallized BaTiO3 powder could be obtained at 1050°C within 10 minutes and the particle size ranged from 300~500nm. In comparison with conventional synthesis, faster speed and finer grains could be achieved through microwave heating.


2014 ◽  
Vol 798-799 ◽  
pp. 110-115
Author(s):  
Alexandre Costa Lanza ◽  
Daniel Thomazini ◽  
Maria Virgínia Gelfuso

Ceramics of Pb1.02(Zr0.53Ti0.47)O3(PZT) comprise the majority of piezoelectric devices in use today. In general, these ceramics are obtained by solid-state reaction, which favors the formation of micrometric grains. Recent studies have shown that reducing the particle size from micro to nanoscale, it generates PZT ceramics with superior dielectric properties. In this way, this study aimed to obtain nanostructured PZT ceramics from the coprecipitate method, using precursor materials as oxides reagents. From the Differential Thermal Analysis (DTA) was observed that the formation of PZT through the proposed methodology is initiated at 550oC. However, the full phase crystallization was observed at 850oC confirmed by X-Ray Diffraction (XRD). Spherical particles near 200nm were observed using scanning electron microscopy (SEM). This powder was sintered in conventional and microwave oven. The ceramics obtained from both sintering methods showed substantial differences in microstructure such as presence of piroclore phase and grain morphology.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

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.


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

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.


MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.


2002 ◽  
Vol 716 ◽  
Author(s):  
Seok Woo Hong ◽  
Yong Sun Lee ◽  
Ki-Chul Park ◽  
Jong-Wan Park

AbstractThe effect of microstructure of dc magnetron sputtered TiN and TaN diffusion barriers on the palladium activation for autocatalytic electroless copper deposition has been investigated by using X-ray diffraction, sheet resistance measurement, field emission scanning electron microscopy (FE-SEM) and plan view transmission electron microscopy (TEM). The density of palladium nuclei on TaN diffusion barrier increases as the grain size of TaN films decreases, which was caused by increasing nitrogen content in TaN films. Plan view TEM results of TiN and TaN diffusiton barriers showed that palladium nuclei formed mainly on the grain boundaries of the diffusion barriers.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

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.


2018 ◽  
Vol 21 (7) ◽  
pp. 495-500 ◽  
Author(s):  
Hassan A. Almarshad ◽  
Sayed M. Badawy ◽  
Abdalkarem F. Alsharari

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.


Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Yan Liu ◽  
Taoling Dong ◽  
Kun Zhang ◽  
Fuwei Yang ◽  
Liqin Wang

Targeting cleaning of the artificial gypsum layer on white marble was studied. It was conducted by means of the specific depletion of the calcium and sulfate ions by the barium carbonate scavenger, which led to the continuous dissolution and clearance of gypsum layer. The cleaning effect was evaluated by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD), capillary suction, and color difference measurement. By this method, only the gypsum layer was cleared away and the carbonate substrate of marble was left intact at the same time. This method will be highly useful for the conservation of marble relics from surface weathering.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaojian Bai ◽  
Chen Jia ◽  
Zhigen Chen ◽  
Yuxuan Gong ◽  
Huwei Cheng ◽  
...  

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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