Temperature Effect on the Thermoluminescent Signal Induced by Gamma Radiation in NaCl

2015 ◽  
Vol 1769 ◽  
Author(s):  
Demetrio Mendoza Anaya ◽  
Pedro R. González Martínez ◽  
María E. Fernández García ◽  
Gilberto Mondragón Galicia ◽  
Claudia E. Gutiérrez Wing

ABSTRACTThe effects of thermal treatments on the thermoluminescent (TL) signal of NaCl (ACS reagent) induced by gamma radiation were investigated. Samples of NaCl were thermally treated at 500, 800 and 1000 °C and characterized by X-Ray diffraction and scanning electron microscopy. After their exposure 0.1 to 150 Gy of gamma radiation from a gamma-ray source of 60Co, a TL curve for each temperature of treatment was obtained. We observed a different TL behavior on the irradiated samples as a function of the temperature applied during the thermal treatments. For the sample treated at 500 °C, three peaks centered at 102, 133 and 228 °C were observed. Samples treated at 800 and 1000 °C showed two main peaks at 128 and 220 °C and 136 and 219 °C, respectively; however, the highest TL intensity signal was observed for the sample at 800 °C. All samples showed a linear dependency of the integrated TL intensity from the signal emitted as function of the irradiation time. This is an important advantage because NaCl could be applied as a very low cost thermoluminescent dosimetric material. A comparison between the TL signal induced by gamma radiation in pure and Eu doped NaCl is also reported.

Cerâmica ◽  
2016 ◽  
Vol 62 (363) ◽  
pp. 278-280 ◽  
Author(s):  
T. H. A. Corrêa ◽  
J. N. F. Holanda

Abstract Calcium pyrophosphate (CPP) was prepared by a simple precipitation method using avian eggshell waste as a low-cost alternative calcium precursor source. The synthesized CPP powder was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM/EDS), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The results indicate that pure β-CPP nanocrystallites (Ca/P = 1.067) were successfully synthesized from avian eggshell waste. The correlation among XRD, SEM/EDS, TGA, and FTIR data is well established. The β-CPP particle exhibited spherical morphology with average crystallite size of 62.3 nm, and can be an important bioceramic for medical applications.


2021 ◽  
Vol 21 (10) ◽  
pp. 5329-5336
Author(s):  
Hongjun Chen ◽  
Zeyang Xue ◽  
Chunhu Yu ◽  
Yajing Mao ◽  
Fanglv Qiu ◽  
...  

Vanadium doped lanthanum bismuthate nanorods with vanadium ratio of 1%, 3%, 5% and 10 wt.% were fabricated through the hydrothermal method using sodium orthovanadate as vanadium source. Vanadium doped lanthanum bismuthate nanorod products were analyzed by scanning electron microscopy, X-ray diffraction pattern and diffuse reflection spectrum. X-ray diffraction patterns show that vanadium in the vanadium doped lanthanum bismuthate nanorods exists as triclinic Bi23V4O44.5 and monoclinic LaVO4 phases. Scanning electron microscopy observations show that the size and micro-morphology of the vanadium doped products are closely relative to the vanadium mass ratio. The length of the vanadium doped nanorods decreases and the morphology changes from nanorods to irregular nanoparticles with increasing the vanadium mass ratio. Solid UV-vis diffuse reflectance measurement shows that the bandgap value of the doped lanthanum bismuthate nanorods is narrowed from 2.37 eV to 2.25 eV after the vanadium doping ratio is increased from 1% to 10%. The doped lanthanum bismuthate nanorods illustrate enhanced photocatalytic performance for methylene orange (MO) removal with the irradiation of sunlight. The catalytic performance for MO removal depends on the irradiation time, vanadium content and dosage of the nanorods. The doped lanthanum bismuthate nanorods with the vanadium mass ratio of 10% possess the best MO catalytic degradation performance.


1997 ◽  
Vol 501 ◽  
Author(s):  
D. L. Schulz ◽  
C. J. Curtis ◽  
R. A. Flitton ◽  
D. S. Ginley

ABSTRACTThe use of nanoparticle colloids for spray deposition of Cu-In-Se precursor films and subsequent thermal treatment to form CuInSe2 (CIS) films has been investigated. In the present study, the metathesis reaction between Na2Se in methanol and metal salts (i.e., Cu(BF4)2 and/or InI3) in pyridine produced CuSe, In2Se3, and CuInSe2.5 nanoparticle colloids. Purified colloid was sprayed onto heated molybdenum-coated sodalime glass substrates to form CuInSe2.5/Mo and In2Se3/CuSe/Mo precursor films. These precursor films were subjected to various thermal treatments in an effort to produce large-grained CIS films from the nano-sized precursors. The annealed CIS films were characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Results of this continuing effort will be discussed.


2011 ◽  
Vol 418-420 ◽  
pp. 597-601
Author(s):  
Gui Lin Chen ◽  
Lu Jin ◽  
Wei Feng Liu ◽  
Guo Shun Jiang ◽  
Chang Fei Zhu

A low-cost non-vacuum process for fabrication of Cu2ZnSnSe4 (CZTSe) films by solvent-free mechanochemical method and spin-coating process is described. First, highly monodisperse Cu, Zn, Sn oxides nanoparticles are synthesized via a facile, solvent-free route. Second, the oxide particulate precursors are deposited in a thin layer by spin-coating technique. Finally, the dry layers are sintered into CZTSe thin films selenization. Through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), it is found that near stoichiometric CZTSe films with a micron-sized grains are obtained in our work.


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.


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