XRD, SEM/EDX and FTIR Characterization of Brazilian Natural Coral

Author(s):  
Herman S. Mansur ◽  
Alexandra A.P. Mansur ◽  
Marivalda Pereira
2005 ◽  
Vol 284-286 ◽  
pp. 43-46 ◽  
Author(s):  
Herman S. Mansur ◽  
Alexandra A.P. Mansur ◽  
Marivalda Pereira

In the present work, natural coral from Brazilian reefs were studied according to their crystallography by X-ray diffraction and microstructure by Scanning Electron Microscopy (SEM/EDX). FTIR spectroscopy was also used to evaluate the chemical functionalities and major components present in the material. The SEM morphology results have shown a tri-dimensional coral structure with porous ranging from 50 to 200 µm. Aragonite was identified as the major crystalline phase through XRD analysis and FTIR spectroscopy. Strontium calcium carbonate, (Sr,Ca)CO3, was also identified by XRD analysis. After sintering at 900º/1h, the conversion from aragonite to CaO and calcite was observed. These results have endorsed the high potential application of natural coral materials as 3D scaffolds for biomedical application, because of calcium carbonate compounds can be converted to HA by hydrothermal and biomimetic coating processes.


1987 ◽  
Vol 65 (5) ◽  
pp. 919-923 ◽  
Author(s):  
A. Scott Hinman ◽  
Brad J. Pavelich

A versatile thin layer spectroelectrochemical cell employing specular reflection of the incident light beam from the electrode surface is described. Its application to in-situ uv–vis and FTIR characterization of the products of electrochemical reactions and to thin layer voltammetry and coulometry as well as conventional cyclic voltammetry is demonstrated for the oxidation of tetraphenylporphinatozinc in dichloroethane/tetrabutylammonium perchlorate solution. The advantages and disadvantages of this type of cell as compared to more conventional sandwich type optically transparent thin layer electrodes are discussed.


2007 ◽  
Vol 127 (1-4) ◽  
pp. 189-198 ◽  
Author(s):  
Oleg S. Alexeev ◽  
Sundaram Krishnamoorthy ◽  
Cody Jensen ◽  
Michael S. Ziebarth ◽  
George Yaluris ◽  
...  

2012 ◽  
Vol 15 (2) ◽  
pp. 187-216 ◽  
Author(s):  
Mercedes Murillo-Barroso ◽  
Marcos Martinón-Torres

The use of amber is documented in the Iberian peninsula since the Palaeolithic. The procurement and trade of this fossil resin has often been considered in discussions of long-distance trade and the emergence of social complexity, but so far no comprehensive view of the Iberian evidence has been produced to allow a more overarching interpretive model. This paper presents the Fourier-transform infrared spectroscopy (FTIR) characterization of archaeological amber from three Iberian prehistoric sites: a necklace recovered from the megalithic site of Palacio III (Almadén de la Plata, Sevilla), a pommel from PP4 Montelirio (Valencina de la Concepción, Sevilla), and a necklace from the Muricecs de Cellers cave (Llimiana, Pallars Jussà, Lleida). Based on these new data and a review of the literature, we present an overview that outlines fluctuations in the use of amber since the Upper Palaeolithic and demonstrates long-distance amber exchange connecting Iberia with northern Europe and the Mediterranean region since the Chalcolithic period at least. We discuss changes in the origins and cultural use of amber and their implications for the consolidation of trade networks.


Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1327 ◽  
Author(s):  
Claire Chunjuan Zhang ◽  
Xingtao Gao ◽  
Bilge Yilmaz

Fluid Catalytic Cracking (FCC) has maintained its crucial role in refining decades after its initial introduction owing to the flexibility it has as a process as well as the developments in its key enabler, the FCC catalyst. Boron-based technology (BBT) for passivation of contaminant metals in FCC catalysts represents one such development. In this contribution we describe Fourier Transform Infrared Spectroscopy (FTIR) characterization of boron-containing catalysts to identify the phase and structural information of boron. We demonstrate that FTIR can serve as a sensitive method to differentiate boron trioxide and borate structures with a detection limit at the 1000 ppm level. The FTIR analysis validates that the boron in the FCC catalysts studied are in the form of small borate units and confirms that the final FCC catalyst product contains no detectable isolated boron trioxide phase. Since boron trioxide is regulated in some parts of the world, this novel FTIR methodology can be highly beneficial for further FCC catalyst development and its industrial application at refineries around the world. This new method can also be applied on systems beyond catalysts, since the characterization of boron-containing materials is needed for a wide range of other applications in the fields of glass, ceramics, semiconductors, agriculture, and pharmaceuticals.


1992 ◽  
Vol 32 (6) ◽  
pp. 438-442 ◽  
Author(s):  
D. Raghavan ◽  
A. E. Torma

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