Evolution of the topographical and chemical signatures of plasma-treated surfaces along the staging time pathway

2016 ◽  
Author(s):  
Ian Harvey Arellano ◽  
Amor Zapanta
Keyword(s):  
Chemical Signatures

scholarly journals Revealing the constituents of Egypt’s oldest beer using infrared and mass spectrometry

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mohamed A. Farag ◽  
Moamen M. Elmassry ◽  
Masahiro Baba ◽  
Renée Friedman
Keyword(s):  
Large Scale ◽  
Beer Brewing ◽  
Chemical Signatures ◽  
Chemical Determination ◽  
Materials Used ◽  
High Level ◽  
Beer Production ◽  
First Time ◽  
Detailed Chemical

Abstract Previous studies have shown that the Ancient Egyptians used malted wheat and barley as the main ingredients in beer brewing, but the chemical determination of the exact recipe is still lacking. To investigate the constituents of ancient beer, we conducted a detailed IR and GC-MS based metabolite analyses targeting volatile and non-volatile metabolites on the residues recovered from the interior of vats in what is currently the world’s oldest (c. 3600 BCE) installation for large-scale beer production located at the major pre-pharaonic political center at Hierakonpolis, Egypt. In addition to distinguishing the chemical signatures of various flavoring agents, such as dates, a significant result of our analysis is the finding, for the first time, of phosphoric acid in high level probably used as a preservative much like in modern beverages. This suggests that the early brewers had acquired the knowledge needed to efficiently produce and preserve large quantities of beer. This study provides the most detailed chemical profile of an ancient beer using modern spectrometric techniques and providing evidence for the likely starting materials used in beer brewing.

Pseudo-C11b Phase Formation of Titanium Disilicide During the C49 to C54 Transition

1997 ◽  
Vol 481 ◽  
Author(s):  
Patrick L. Smith ◽  
Richard Ortega ◽  
Bill Brennan
Keyword(s):  
Thin Films ◽  
Plane Wave ◽  
Intermediate Phase ◽  
Unit Cell ◽  
Silicon Substrates ◽  
Unit Cell Parameters ◽  
Titanium Disilicide ◽  
Cell Parameters ◽  
Chemical Signatures ◽  
Pseudo Potential

ABSTRACTThe formation of TiSi2 thin films using the SALICIDE process on doped and undoped silicon substrates was studied. XRD TEM, AES, RBS and four probe Rs were used to characterize the material. Unit cell parameters and energetics were determined. Results confirm electrical and chemical signatures consistent with the known C49 conversion to C54. However, XRD indicated a structurally different intermediate phase occurs during the C49 to C54 transformation. Modeling was performed based on C11b structure (14/mmm) type, with the Ti and Si atoms arranged similarly to those in MoSi2. The unit cell was determined to be a = 4.428 Å, b = 4.779 Å, c = 9.078 Å with a Fmmm space group and total pseudo-potential plane wave calculations based on crystallographic simulations of −103.96 ev/Atom.

Kinematic and chemical signatures of the formation processes of the galactic thick disk

2010 ◽  
Vol 45 ◽  
pp. 437-440
Author(s):  
A. Spagna ◽  
A. Curir ◽  
M.G. Lattanzi ◽  
G. Murante ◽  
P. Re Fiorentin ◽  
...  
Keyword(s):  
Thick Disk ◽  
Formation Processes ◽  
Chemical Signatures

scholarly journals THE CHEMICAL SIGNATURES OF THE FIRST STAR CLUSTERS IN THE UNIVERSE

2010 ◽  
Vol 721 (1) ◽  
pp. 582-596 ◽  
Author(s):  
Joss Bland-Hawthorn ◽  
Torgny Karlsson ◽  
Sanjib Sharma ◽  
Mark Krumholz ◽  
Joe Silk
Keyword(s):  
Star Clusters ◽  
Chemical Signatures ◽  
The Universe

ChemInform Abstract: Chemical Signatures of Fossilized Resins and Recent Plant Exudates.

ChemInform ◽  
2009 ◽  
Vol 40 (10) ◽  
Author(s):  
Joseph B. Lambert ◽  
Jorge A. Santiago-Blay ◽  
Ken B. Anderson
Keyword(s):  
Chemical Signatures ◽  
Plant Exudates

Rejuvenation events recorded in alkali feldspar from the Tuolumne Intrusive Complex

2021 ◽  
Author(s):  
Susanne Seitz ◽  
Guilherme Gualda ◽  
Luca Caricchi
Keyword(s):  
Trace Elements ◽  
Hierarchical Clustering ◽  
Alkali Feldspar ◽  
Growth Conditions ◽  
Major And Trace Elements ◽  
Sem Analysis ◽  
Intrusive Complex ◽  
Cluster Number ◽  
Chemical Zoning ◽  
Chemical Signatures

<p>Zoned minerals preserve information about their growth conditions, by changing their composition as function of temperature, pressure and melt composition. By carefully looking at a zoned minerals we can determine characteristics of the main stages of the evolution of magmatic systems.</p><p>We study alkali feldspar megacrysts from the Tuolumne Intrusive Complex in California, with the aim of deciphering chemical signatures of rejuvenation events. We characterize the chemical zoning of alkali feldspar using X-ray tomography, BSE imaging, EDS-SEM analysis and LA-ICPMS analysis along profiles. We use hierarchical clustering based on major and trace elements to objectively identify compositional groups for each chemical profile. By reducing the complexity of chemical zoning to one dimension (i.e. cluster number) we can trace the evolution of the conditions of growth and identify rejuvenation events.</p><p>Alkali feldspar megacrysts (up to 20 cm in size) from the Cathedral Peak unit of the Tuolumne Intrusive Complex occur predominantly disperse and only make between 8 - 12 % of the total crystal population. They are mostly homogeneous in major element, and markedly oscillatory zoned in trace elements such as Ba, Sr, and Rb. Using hierarchical clustering we identify four different chemical groups within the alkali feldspar crystals. Each chemical group is repeated multiple times in a single crystal. Overall the crystals show a decreasing trend of Ba towards the rim. Extended alkali feldspar crystallization would lead to a depletion of Ba in the melt and consequently to the growth of low Ba-zones of alkali feldspar. In some crystals the sequence of decreasing Ba is repeated twice. We propose that this reflects melt recharge in a melt-rich magmatic system.</p>

Conservation, Ecology, and Management of Catfish: The Second International Symposium

2011 ◽  
Keyword(s):  
Water Chemistry ◽  
Environmental History ◽  
Ictalurus Punctatus ◽  
Water Samples ◽  
Process Chemistry ◽  
Chemical Signatures ◽  
Spatial Differences ◽  
Pectoral Spine ◽  
History Of ◽  
Highly Correlated

<em>Abstract</em>.—Natural chemical markers in otoliths and fin rays have proven useful for retrospectively describing environmental history of fishes in a variety of environments. However, no studies have applied this technique to catfishes or evaluated catfish pectoral spine chemistry as a nonlethal alternative to otolith chemistry. We characterized relationships between water, otolith, and pectoral spine (articulating process) chemistry for channel catfish <em>Ictalurus punctatus</em>, flathead catfish <em>Pylodictis olivaris</em>, and blue catfish <em>I. furcatus</em> and determined the accuracy with which fish could be classified to their environment of capture using otolith and pectoral spine chemical signatures. Fish and water samples were collected from nine sites during 2009. Otolith, spine, and water samples were analyzed for Sr:Ca and Ba:Ca; otolith δ<sup>18</sup>O and δ<sup>13</sup>C and water δ<sup>18</sup>O were also measured. Water, otolith, and spine Sr:Ca were highly correlated, as were water and otolith δ<sup>18</sup>O. Relationships between water, otolith, and spine chemistry did not differ among species. Otolith Sr:Ca, δ<sup>18</sup>O, and δ<sup>13</sup>C and spine Sr:Ca differed among sites, reflecting geographic differences in water chemistry. Neither otolith nor spine Ba:Ca differed among sites despite intersite differences in water Ba:Ca. Both otolith Sr:Ca, δ<sup>18</sup>O, and δ<sup>13</sup>C and fin spine Sr:Ca classified fish to their environment of capture with a high degree of accuracy, except in the middle and lower Mississippi River where many recent immigrants appeared to be present. Natural chemical signatures in otoliths or pectoral spines will likely be effective for reconstructing environmental history of catfishes when spatial differences in water chemistry are present, enabling investigations of stock mixing and recruitment sources for these species.

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