Visualization of the internal structures of cultured pearls by computerized X-ray microtomography

2008 ◽  
Vol 31 (1) ◽  
pp. 15-21 ◽  
Author(s):  
U. Wehrmeister ◽  
H. Goetz ◽  
D.E. Jacob ◽  
A. Soldati ◽  
W. Xu ◽  
...  
Keyword(s):  
X Ray ◽  
Internal Structures ◽  
Cultured Pearls

scholarly journals Principles of Different X-ray Phase-Contrast Imaging: A Review

2021 ◽  
Vol 11 (7) ◽  
pp. 2971
Author(s):  
Siwei Tao ◽  
Congxiao He ◽  
Xiang Hao ◽  
Cuifang Kuang ◽  
Xu Liu
Keyword(s):  
Biological Samples ◽  
Phase Contrast ◽  
Recent Progress ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray ◽  
X Ray Imaging ◽  
Internal Structures ◽  
X Ray Absorption ◽  
Made In

Numerous advances have been made in X-ray technology in recent years. X-ray imaging plays an important role in the nondestructive exploration of the internal structures of objects. However, the contrast of X-ray absorption images remains low, especially for materials with low atomic numbers, such as biological samples. X-ray phase-contrast images have an intrinsically higher contrast than absorption images. In this review, the principles, milestones, and recent progress of X-ray phase-contrast imaging methods are demonstrated. In addition, prospective applications are presented.

Identification of High-Luster and Lusterless Freshwater-Cultured Pearls by X-Ray Absorption Spectroscopy

2015 ◽  
Vol 82 (4) ◽  
pp. 677-680 ◽  
Author(s):  
N. Monarumit ◽  
N. Noirawee ◽  
A. Phlayrahan ◽  
K. Promdee ◽  
K. Won-in ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
X Ray ◽  
X Ray Absorption ◽  
Cultured Pearls

Structural Analysis of Freshwater-Cultured Pearls with Different Lusters Using the Extended X-Ray Absorption Fine Structure Technique

2016 ◽  
Vol 83 (2) ◽  
pp. 298-301
Author(s):  
N. Monarumit ◽  
N. Noirawee ◽  
A. Phlayrahan ◽  
K. Promdee ◽  
K. Won-in ◽  
...  
Keyword(s):  
Fine Structure ◽  
Structural Analysis ◽  
X Ray ◽  
Absorption Fine ◽  
X Ray Absorption ◽  
Cultured Pearls

scholarly journals Synchrotron radiation X-ray tomographic microscopy (SRXTM) of brachiopod shell interiors for taxonomy: Preliminary report

2010 ◽  
pp. 109-117 ◽  
Author(s):  
Neda Motchurova-Dekova ◽  
David Harper
Keyword(s):  
Synchrotron Radiation ◽  
Three Dimensional ◽  
X Rays ◽  
X Ray ◽  
Fine Grained ◽  
Internal Structures ◽  
Efficient Alternative ◽  
Micro Tomography ◽  
Light Beams ◽  
Non Destructive

Synchrotron radiation X-ray tomographic microscopy (SRXTM) is a non-destructive technique for the investigation and visualization of the internal features of solid opaque objects, which allows reconstruction of a complete three-dimensional image of internal structures by recording of the differences in the effects on the passage of waves of energy reacting with those structures. Contrary to X-rays, produced in a conventional X-ray tube, the intense synchrotron light beams are sharply focused like a laser beam. We report encouraging results from the use of SRXTM for purely taxonomic purposes in brachiopods: an attempt to find a non-destructive and more efficient alternative to serial sectioning and several other methods of dissection together with the non-destructive method of X-ray computerised micro-tomography. Two brachiopod samples were investigated using SRXTM. In ?Rhynchonella? flustracea it was possible to visualise the 3D shape of the crura and dental plates. In Terebratulina imbricata it was possible to reveal the form of the brachidium. It is encouraging that we have obtained such promising results using SRXTM with our very first two fortuitous samples, which had respectively fine-grained limestone and marl as infilling sediment, in contrast to the discouraging results communicated to us by some colleagues who have tested specimens with such infillings using X-ray micro-tomography. In future the holotypes, rare museum specimens or delicate Recent material may be preferentially subjected to this mode of analysis.

Optimization of PIXE quantitative system to assist traceability of pearls

2017 ◽  
Vol 27 (03n04) ◽  
pp. 125-133
Author(s):  
S. Murao ◽  
K. Sera ◽  
S. Goto ◽  
C. Takahashi ◽  
L. Cartier ◽  
...  
Keyword(s):  
Supply Chain ◽  
Trace Element ◽  
Standard Method ◽  
Good Accuracy ◽  
Trace Element Analysis ◽  
Social Attention ◽  
Element Analysis ◽  
X Ray ◽  
Cultured Pearls

Recent rise of social attention towards ethical jewelry has led scientists to a challenge of how to construct analytical systems that can deliver in line with social and supply chain expectations. Of the various kinds of methods, “Proton/Particle-Induced X-ray Emission” (PIXE) seems to be robust and promising in characterizing gemstones because of its capability of trace element analysis without destruction. The authors established a non-standard method to analyze cultured pearls and applied it to test specimens from different places. The results showed that PIXE could detect important elements for pearl study with good accuracy and sensitivity and that pearl chemistry can be useful to differentiate freshwater and marine pearl products.

Computer reconstructed X-ray imaging

1979 ◽  
Vol 292 (1390) ◽  
pp. 223-232 ◽  
Keyword(s):  
Spatial Resolution ◽  
Atomic Number ◽  
High Sensitivity ◽  
Precise Determination ◽  
Diagnostic Methods ◽  
X Ray ◽  
X Ray Imaging ◽  
Internal Structures ◽  
Transmission Measurements

Computed tomography is a method for obtaining a series of radiographic pictures of contiguous slices through a solid object such as the human body. Each picture is computed from a set of X-ray transmission measurements and represents the distribution of X-ray attenuation in the slice. The high sensitivity of the method to changes in both density and atomic number has resulted in the development of new diagnostic methods in medicine. The limitations of the method are discussed in terms of two particular kinds of application. First, those applications in which a very precise determination of density or atomic number is required, but at low spatial resolution; an example would be the determination of the uniformity of mixture of plastics or metals. The second kind of application is that requiring high spatial resolution as in the detection of cracks and the visualization of internal structures in complicated objects.

Synthesis and Electrorheological Characteristics of Conducting Polymer/Clay Nanocomposites

2007 ◽  
Vol 124-126 ◽  
pp. 1083-1086
Author(s):  
Jun Hee Sung ◽  
Hyoung Jin Choi
Keyword(s):  
Conducting Polymer ◽  
Electrorheological Fluid ◽  
Clay Nanocomposites ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Internal Structures ◽  
In Situ Emulsion Polymerization

Nanocomposites of conducting polymers of polyaniline (PANI), poly(oethoxyaniline) (PEOA) and polypyrrole (PPy) with clay prepared via either in-situ emulsion polymerization or solvent intercalation were investigated especially for electrorheological fluid (ER) application. Internal structures of these nanocomposites were examined via wide angle X-ray diffraction (WAXD), and transmission electron microscope (TEM). The intercalated nanostructures analyzed via WAXD and TEM were correlated with the electrical property change originated from the nanoscale interaction between clay and conducting polymer. Moreover, their ER behaviors were measured via rotational rheometer with external electric field controller.

scholarly journals X-RAY COMPUTER TOMOGRAPHY IN THE STUDY OF ARTICULATE BRACHIOPODS

2021 ◽  
Vol 6 (12(81)) ◽  
pp. 9-14
Author(s):  
T. Grunt
Keyword(s):  
Computer Tomography ◽  
Host Rock ◽  
Mineral Component ◽  
Thin Sections ◽  
X Ray ◽  
Internal Structures ◽  
Traditional Production

The advantage of the currently widely used method of X-ray computer tomography for the studying the internal structures of paleontological objects including Articulate Brachiopods, in comparison with the traditional production of thin sections and replicas is that there is no need for destruction of the object under the study. The most productive results are achieved using the SkyScan-1172 microtomograph when studying objects which obtain sufficient contrast between the mineral component of the shell and the host rock.  

scholarly journals Chemical Characteristics of Freshwater and Saltwater Natural and Cultured Pearls from Different Bivalves

Minerals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 357 ◽  
Author(s):  
Stefanos Karampelas ◽  
Fatima Mohamed ◽  
Hasan Abdulla ◽  
Fatema Almahmood ◽  
Latifa Flamarzi ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Chemical Elements ◽  
Manganese Content ◽  
Green Luminescence ◽  
X Ray ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Pinctada Maxima ◽  
Cultured Pearls

The present study applied Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) on a large number of natural and cultured pearls from saltwater and freshwater environments, which revealed that freshwater (natural and cultured) pearls contain relatively higher quantities of manganese (Mn) and barium (Ba) and lower sodium (Na), magnesium (Mg) and strontium (Sr) than saltwater (natural and cultured) pearls. A few correlations between the host animal’s species and chemical elements were found; some samples from Pinctada maxima (P. maxima) are the only studied saltwater samples with 55Mn >20 ppmw, while some P. radiata are the only studied saltwater samples with 24Mg <65 ppmw and some of the P. imbricata are the only studied saltwater samples with 137Ba >4.5 ppmw. X-ray luminescence reactions of the studied samples has confirmed a correlation between its yellow-green intensity and manganese content in aragonite, where the higher Mn2+ content, the more intense the yellow-green luminescence becomes. Luminescence intensity in some cases is lower even if manganese increases, either because of pigments or because of manganese self-quenching. X-ray luminescence can be applied in most cases to separate saltwater from freshwater samples; only samples with low manganese content (55Mn <50 ppmw) might be challenging to identify. One of the studied natural freshwater pearls contained vaterite sections which react by turning orange under X-ray due to a different coordination of Mn2+ in vaterite than that in aragonite.

scholarly journals Cretaciella sorianoae gen. et sp. nov. (Coleoptera, Leiodidae, Cholevinae, Oritocatopini), Anophthalmic Species from Albian Amber of the Escucha Formation (Alava, Spain)

Geosciences ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 521 ◽  
Author(s):  
Michel Perreau
Keyword(s):  
Phase Contrast ◽  
Sub Saharan Africa ◽  
X Ray ◽  
Extant Species ◽  
Internal Structures ◽  
Sub Saharan

Cretaciella sorianoae gen. et sp. nov. (Coleoptera, Leiodidae, Cholevinae, Oritocatopini) from Albian amber of the Escucha Formation (Alava, Spain) is described and illustrated. This is the first species of Leiodidae from Alava amber and the first Cholevinae from Cretaceous amber. External and internal structures are investigated by propagation phase contrast X-ray microtomography. Based on both external and genital structures, Cretaciella is tentatively placed in the tribe Oritocatopini, the extant species of which occur in Sub-Saharan Africa. This specimen has no visible eyes or hind wings, which suggests an adaptation to subterranean or at least to soil litter environments. The biogeography of the tribe is succinctly discussed.

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