scholarly journals In situ distribution and characterization of the organic content of the oyster shell Crassostrea gigas (Mollusca, Bivalvia)

Micron ◽  
2013 ◽  
Vol 44 ◽  
pp. 373-383 ◽  
Author(s):  
Yannicke Dauphin ◽  
Alexander D. Ball ◽  
Hiram Castillo-Michel ◽  
Corinne Chevallard ◽  
Jean-Pierre Cuif ◽  
...  
Elkawnie ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 329
Author(s):  
Lia Handayani ◽  
Azwar Thaib ◽  
Nurhayati Nurhayati ◽  
Yayuk Astuti ◽  
Adi Darmawan

Abstract: Oyster shell waste has been investigated as a raw material for making adsorbents that will be activated. Physical activation uses temperatures of 500 ºC, 600 ºC, 700 ºC, 800 ºC, 900 ºC and chemical activation uses ZnCl2 with a concentration of 1 %, 5 %, 10 % and 15 %. Based on the analysis of the characteristics that have been carried out for physically activated adsorbents, the oyster shell calcined at 800 ºC produces the best characteristics, it is a radius of 35.11 Å with a percentage of removal of 38.04 %, as well as the results of the FTIR, XRF and SEM analysis gives the best results among others. Whereas for chemically activated adsorbents, the use of activator ZnCl2 10% produces adsorbents with the best characteristics among others with a radius of 84.14 Å and removal percentage of 65.68 %, the best results for adsorbents activated using 10% ZnCl2 are also supported by analysis results given by FTIR, XRF, and SEM.Keywords: Adsorbent; BET; Cr6+; Oyster Shell Waste; XRF Abstrak: Cangkang tiram (Crassostrea gigas) telah diteliti sebagai bahan baku pembuatan adsorben yang akan diaktivasi secara fisika dan kimia. Pembuatan adsorben dengan aktivasi secara fisika menggunakan variasi suhu 500 ºC, 600 ºC, 700 ºC, 800 ºC dan 900 ºC. sedangkan aktivasi kimia yaitu menggunakan aktivator ZnCl2 menggunakan variasi konsentrasi 1 %, 5 %, 10% dan 15 %. Berdasarkan analisa karakteristik yang telah dilakukan untuk adsorben-adsorben yang telah diaktivasi secara fisika, cangkang tiram yang di kalsinasi pada suhu 800ºC menghasilkan karakteristik yang paling baik, yaitu radius pori-pori 35,11 Å dengan persentase penyisihan sebesar 38,04 %, begitu pula dengan hasil analisa FTIR, XRF dan SEM memberikan hasil terbaik diantara yang lain. sedangkan untuk adsorben-adsorben yang diaktivasi secara kimia, penggunaan aktivator ZnCl2 10% menghasilkan adsorben dengan karakteristik yang paling baik diantara lainnya dengan radius pori-pori 84,14 Å dan persentase penyisihan sebesar 65,68%, hasil terbaik untuk adsorben yang diaktivasi menggunakan ZnCl2 10 % juga didukung oleh hasil analisa dari FTIR, XRF dan SEM.


Elkawnie ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 77
Author(s):  
Lia Handayani ◽  
Cut Rahmawati ◽  
Nurhayati Nurhayati ◽  
Yayuk Astuti ◽  
Adi Darmawan

Abstract : Oyster shell as one of the highest bio-waste in Alue Naga Aceh Besar District, Indonesia, was used as an adsorbent to remove a heavy metal Cr (VI) ion. The study was started by calcinating oyster shells at a high temperature of 800 ºC for 3 hours. The effect of various acid (H2SO4) and base (NaOH) activator was studied using characterization and adsorption experiments. The characterization obtained the sample activated by 10% NaOH (Na10-ACT) and 10% H2SO4 (H10-ACT) had the highest surface area which had 14.23 m2/g, 10.77 m2/g, respectively. Furthermore, the adsorption experiments confirmed the highest surface area by showing the highest Cr (IV) ion removal of 57.66%, 70.7%, respectively. The further investigation using X-ray fluorescence (XRF) determined that the Na10-ACT adsorbent has a better composition compared to the H10-ACT due to its high purities.Abstrak : Cangkang tiram sebagai salah satu bio-limbah padat di Desa Alue Naga Kabupaten Aceh Besar, digunakan sebagai adsorben untuk menghilangkan ion logam berat Cr (IV). Penelitian ini diawali dengan mengkalsinasi cangkang tiram pada temperatur tinggi 800ºC selama tiga jam. Pengaruh penambahan aktivator asam (H2SO4) dan basa (NaOH) juga dipelajari melalui karakterisasi dan pengujian adsorpsi. Hasil karakterisasi menunjukkan sampel yang diaktivasi dengan 10% NaOH (Na10-ACT) dan 10% H2SO4 (H10-ACT) memiliki luas permukaan tertinggi yaitu 14,23 m2/g, 10,77 m2/g, masing-masing. Lebih lanjut, pengujian adsorpsi juga mendukung luas permukaan yang tinggi dengan menghilangkan ion Cr (IV) sebesar 57,66%, 70,7%, masing-masing. Investigasi melalui analisa XRF menyimpulkan bahwa Na10-ACT memiliki komposisi yang lebih baik dibanding H10-ACT karena memiliki kemurnian yang tinggi.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
J. I. Bennetch

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.


Author(s):  
J. Liu ◽  
M. Pan ◽  
G. E. Spinnler

Small metal particles have peculiar chemical and physical properties as compared to bulk materials. They are especially important in catalysis since metal particles are common constituents of supported catalysts. The structural characterization of small particles is of primary importance for the understanding of structure-catalytic activity relationships. The shape and size of metal particles larger than approximately 5 nm in diameter can be determined by several imaging techniques. It is difficult, however, to deduce the shape of smaller metal particles. Coherent electron nanodiffraction (CEND) patterns from nano particles contain information about the particle size, shape, structure and defects etc. As part of an on-going program of STEM characterization of supported catalysts we report some preliminary results of CEND study of Ag nano particles, deposited in situ in a UHV STEM instrument, and compare the experimental results with full dynamical simulations in order to extract information about the shape of Ag nano particles.


Reproduction ◽  
2000 ◽  
pp. 325-335 ◽  
Author(s):  
A Calvo ◽  
LM Pastor ◽  
S Bonet ◽  
E Pinart ◽  
M Ventura

Lectin histochemistry was used to perform in situ characterization of the glycoconjugates present in boar testis and epididymis. Thirteen horseradish peroxidase- or digoxigenin-labelled lectins were used in samples obtained from healthy fertile boars. The acrosomes of the spermatids were stained intensely by lectins with affinity for galactose and N-acetyl-galactosamine residues, these being soybean, peanut and Ricinus communis agglutinins. Sertoli cells were stained selectively by Maackia ammurensis agglutinin. The lamina propria of seminiferous tubules showed the most intense staining with fucose-binding lectins. The Golgi area and the apical part of the principal cells of the epididymis were stained intensely with many lectins and their distribution was similar in the three zones of the epididymis. On the basis of lectin affinity, both testis and epididymis appear to have N- and O-linked glycoconjugates. Spermatozoa from different epididymal regions showed different expression of terminal galactose and N-acetyl-galactosamine. Sialic acid (specifically alpha2,3 neuraminic-5 acid) was probably incorporated into spermatozoa along the extratesticular ducts. These findings indicate that the development and maturation of boar spermatozoa are accompanied by changes in glycoconjugates. As some lectins stain cellular or extracellular compartments specifically, these lectins could be useful markers in histopathological evaluation of diseases of boar testis and epididymis.


2018 ◽  
Author(s):  
Devon Jakob ◽  
Le Wang ◽  
Haomin Wang ◽  
Xiaoji Xu

<p>In situ measurements of the chemical compositions and mechanical properties of kerogen help understand the formation, transformation, and utilization of organic matter in the oil shale at the nanoscale. However, the optical diffraction limit prevents attainment of nanoscale resolution using conventional spectroscopy and microscopy. Here, we utilize peak force infrared (PFIR) microscopy for multimodal characterization of kerogen in oil shale. The PFIR provides correlative infrared imaging, mechanical mapping, and broadband infrared spectroscopy capability with 6 nm spatial resolution. We observed nanoscale heterogeneity in the chemical composition, aromaticity, and maturity of the kerogens from oil shales from Eagle Ford shale play in Texas. The kerogen aromaticity positively correlates with the local mechanical moduli of the surrounding inorganic matrix, manifesting the Le Chatelier’s principle. In situ spectro-mechanical characterization of oil shale will yield valuable insight for geochemical and geomechanical modeling on the origin and transformation of kerogen in the oil shale.</p>


1983 ◽  
Author(s):  
K. Arulanandan ◽  
Y. Dafalias ◽  
L. R. Herrmann ◽  
A. Anandarajah ◽  
N. Meegoda

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