Intergrowth of several solid phases from the Y–Ni–B–C system in a large YNi2B2C crystal

2008 ◽  
Vol 41 (4) ◽  
pp. 738-746 ◽  
Author(s):  
Torsten Weissbach ◽  
Tilmann Leisegang ◽  
Andreas Kreyssig ◽  
Matthias Frontzek ◽  
Jens-Uwe Hoffmann ◽  
...  

A YNi2B2C single crystal containing traces of foreign phases was inspected by means of neutron and X-ray diffraction as well as scanning electron microscopy and X-ray spectroscopy methods. The diffraction patterns obtained from the experiments look similar to those expected for a superstructure. Nevertheless, they can be interpreted as crystallographically oriented precipitations of YB2C2and Ni2B within the YNi2B2C crystal, formed during the cooling process. The orientation relation between the lattices was obtained from experimental neutron and X-ray data. Structure refinements of the collected X-ray data were performed by separation of the intensity data of the individual phases. Scanning electron microscopy images of the inclusions found on a polished cross section of the crystal are presented; their chemical composition was determined using wavelength-dispersive X-ray analysis.

2012 ◽  
Vol 727-728 ◽  
pp. 982-987
Author(s):  
E. de Carvalho ◽  
Marcelo Bertolete ◽  
Izabel Fernanda Machado ◽  
E.N.S. Muccillo

Polycrystalline CaCu3Ti4O12 ceramics were prepared by solid state reactions by spark plasma sintering (SPS) technique. In this study, the effects of the dwell temperature on structural, microstructural and dielectric properties of CaCu3Ti4O12 ceramics have been investigated. Powder mixtures were calcined at 900°C for 18 h before SPS consolidation. The dwell temperatures were 850, 900, 915 and 930°C. Sintered pellets were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. X-ray diffraction patterns show evidences of a single-phase perovskite-type structure. The calculated lattice parameter is 7.40 Å. The hydrostatic density increases slightly with increasing dwell temperature. Scanning electron microscopy observations revealed a heterogeneous microstructure for all samples. The dielectric loss remains constant over a wide temperature range. The obtained permittivity is approximately 103 at 1 kHz. The increase of the dwell temperature is found to produce a brittle ceramic.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Rodholfo da Silva Barbosa Ferreira ◽  
Caio Henrique do Ó Pereira ◽  
Rene Anisio da Paz ◽  
Amanda Melissa Damião Leite ◽  
Edcleide Maria Araújo ◽  
...  

The nanocomposites have an extensive use in the current process of membrane preparation, taking into account their unique features as membranes. Thus, the study of nanocomposite processing to obtain membranes is highly important. In this work, Brazilian clay was used (Brasgel PA) for the preparation of polyamide/clay nanocomposite. The nanocomposites were produced in a high rotation homogenizer and in a twin screw extruder. From the nanocomposites and pure polymers processed in the two equipments, membranes were prepared by the immersion-precipitation method, using formic acid as solvent. By X-ray diffraction (XRD), the formation of exfoliated and/or partially exfoliated structures with changes in the crystalline phases of the polyamide was observed. From scanning electron microscopy images, it was observed that the processing clearly influenced the membrane morphology.


2012 ◽  
Vol 151 ◽  
pp. 310-313
Author(s):  
Jenn Sen Lin ◽  
Teng Chin Yu ◽  
Cheng Hsing Hsu ◽  
Ci Jie Huang ◽  
His Wen Yang

The microstructure properties of the perovskite Bi0.5Na0.5TiO3-BaZrO3 ceramics were prepared with the conventional solid-state route have been investigated. The resultant microstructure properties were analyzed based upon the densification, the X-ray diffraction patterns and scanning electron microscopy. The correlation between the microstructures and the sintering temperature was also examined.


2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Xiao Wang ◽  
Xiaoxing Wei ◽  
Caixia Song

Semimetal Bi and Sb thin films with novel hierarchical structures were synthesized on zinc substrate via a hydrothermal method. X-ray diffraction (XRD) analysis confirmed the formation of pure semimetals Bi and Sb. Scanning electron microscopy images showed that Bi films constructed with microtube arrays and hierarchical microspheres can be obtained selectively by altering the concentration of Bi3+ions. The synthesized Sb films were constructed with bowl-shaped particles. The growth process of these semimetal architectures was briefly discussed.


2018 ◽  
Vol 42 (1) ◽  
pp. 18-22
Author(s):  
Khitam S. S

     This research aims to prepare ZnO NPs by using chemical bath deposition way from ZnSO4 and NaOH as starting materials. It was examined by X-ray diffraction, Scanning Electron Microscopy, Zeta potential and Fourier Transformation Infrared. Scanning Electron Microscopy images showed various morphological changes of ZnO nanoparticles obtained by the above method and the different magnification Scanning Electron Microscopy images of the nanoparticle and confirms that the Nano flowers are grown with well-defined morphology and diameters varying between 60-110 nm. The effect of Zinc oxide nanoparticles against bacteria staphylococcus aureus, E.coli and Pseudomous aeruginosa showed the ability of this substance to inhibit the growth of all types of bacteria in different concentrations. The percentage of survival bacteria was (2, 3.7 and 6%) for E.coli bacteria and (1, 1.5 and 5 %) for Pseudomous aeruginosa bacteria, while the percentage was (0.8, 1 and 1.5 %) for staphylococcus aurous respectively for all concentration.


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.


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.


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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