scholarly journals Proof-of-concept development of PXAMS (projectile x-ray accelerator mass spectrometry)

1996 ◽  
Author(s):  
I.D. Proctor ◽  
M.L. Roberts ◽  
J.E. McAninch ◽  
G.S. Bench
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Concept Development ◽  
Proof Of Concept ◽  
X Ray

Application of XRF and AMS Techniques to Textiles in the Mongol Empire

2007 ◽  
Vol 1047 ◽  
Author(s):  
Tomoko Katayama ◽  
Ari Ide-Ektessabi ◽  
Kazuki Funahashi ◽  
Ryoichi Nishimura
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Fluorescence Analysis ◽  
Process Technology ◽  
X Ray ◽  
Central Asian ◽  
Sr Xrf ◽  
High Resolution Images ◽  
Mongol Empire ◽  
Constituent Elements

AbstractX-ray fluorescence (XRF) and Accelerator Mass Spectrometry (AMS) techniques were applied to four pieces of ancient Mongolian textiles in order to assist cultural studies of the most significant era of medieval western Asian culture. Radiocarbon dating using Accelerator Mass Spectrometry (AMS) was performed in order to determine the historical age of these pieces. Then, X-ray fluorescence analysis using Synchrotron Radiation (SR-XRF) was carried out in order to obtain elemental maps as well as investigate their constituent elements. Results showed that the textiles were produced between13th and 14th century, and possessed elements such as Au, Cu, Fe and Ti were traced in these pieces whereas Au was used to make gold threads. Cu, Fe and Ti are well known as metallic mordant. In addition, high resolution images were obtained using Scanning Electron Microscope (SEM) to observe the textile structure and their weaving conditions. The whole collected data can assist in bringing into light and facilitate a deeper understanding of the medieval Mongolian cultures, the textile technology, staining techniques, material process technology of the Mongolian Empire and their relations with the neighboring east and central Asian cultures, such as Persia, India and China.

scholarly journals Archaeology of rock art at Dalakngalarr 1, centralwestern Arnhem Land

2021 ◽  
Author(s):  
Daniel James ◽  
Bruno David ◽  
Jean-Jacques Delannoy ◽  
Robert Gunn ◽  
Alexandria Hunt ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Rock Art ◽  
Present Position ◽  
Radiocarbon Dates ◽  
X Ray ◽  
The Past ◽  
Arnhem Land ◽  
Archaeological Excavations ◽  
Lines Of Evidence

In 2011, we began researching the subsurface archaeology, geomorphology and rock art ofDalakngalarr 1, a moderately sized rock shelter on top of the central-western Arnhem Landplateau in Jawoyn Country. Here, four lines of evidence give relative or absolute ages for rockart:1. Archaeological excavations adjacent to a boulder that contains a painting of a red macropodreveal when that boulder attained its present position, so the red macropod must have beenpainted sometime afterwards.2. Paintings of axe/hoes with metal heads indicate that they were painted during the Europeancontact period. A nearby group of X-ray images are painted in comparable pigments,suggesting that they are contemporaneous with the axe/hoes.3. Geomorphological evidence suggests that parts of the site’s ceiling collapsed at datable timesin the past, indicating that the art on that roof must post-date the roof collapse.4. Direct accelerator mass spectrometry (AMS) radiocarbon dates on beeswax art.

Imaging of Al-Li-Cu alloys with a Scanning Ion Microprobe

1990 ◽  
Vol 48 (2) ◽  
pp. 314-315
Author(s):  
K.K. Soni ◽  
D.B. Williams ◽  
J.M. Chabala ◽  
R. Levi-Setti ◽  
D.E. Newbury
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Equilibrium Phase ◽  
Icosahedral Symmetry ◽  
Ion Microprobe ◽  
X Ray ◽  
Cu Alloys ◽  
Two Phases ◽  
The University ◽  
Secondary Ion

In contrast to the inability of x-ray microanalysis to detect Li, secondary ion mass spectrometry (SIMS) generates a very strong Li+ signal. The latter’s potential was recently exploited by Williams et al. in the study of binary Al-Li alloys. The present study of Al-Li-Cu was done using the high resolution scanning ion microprobe (SIM) at the University of Chicago (UC). The UC SIM employs a 40 keV, ∼70 nm diameter Ga+ probe extracted from a liquid Ga source, which is scanned over areas smaller than 160×160 μm2 using a 512×512 raster. During this experiment, the sample was held at 2 × 10-8 torr.In the Al-Li-Cu system, two phases of major importance are T1 and T2, with nominal compositions of Al2LiCu and Al6Li3Cu respectively. In commercial alloys, T1 develops a plate-like structure with a thickness <∼2 nm and is therefore inaccessible to conventional microanalytical techniques. T2 is the equilibrium phase with apparent icosahedral symmetry and its presence is undesirable in industrial alloys.

scholarly journals Hiatus in Prehistoric Chronology of the Cis-Baikal Region, Siberia: Pattern or Artifact?

Radiocarbon ◽  
2007 ◽  
Vol 49 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Yaroslav V Kuzmin
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Baikal Region ◽  
Critical Evaluation ◽  
Burial Grounds

The problem of a hiatus at about 6100–5300 BP (about 4900–4200 cal BC) in the prehistoric chronology of the Cis-Baikal region in Siberia is discussed. Based on a critical evaluation of existing evidence, there was no discontinuity found in the cultural sequence between the Kitoi and Serovo/Glazkovo complexes of the Neolithic, and the proposed “hiatus” may be an artifact based on underestimation of solid data. Conventional 14C dates are presented that were generated in the 1980s to early 2000s for Cis-Baikal prehistoric burial grounds, and were later dated by the accelerator mass spectrometry (AMS).

Resolution of a protein sequence ambiguity by X-ray crystallographic and mass spectrometric methods

1992 ◽  
Vol 25 (2) ◽  
pp. 205-210 ◽  
Author(s):  
L. J. Keefe ◽  
E. E. Lattman ◽  
C. Wolkow ◽  
A. Woods ◽  
M. Chevrier ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Electron Density ◽  
Mass Spectrometric ◽  
Amino Acid Sequences ◽  
Data Matrix ◽  
Protein Crystal ◽  
Insertion Mutant ◽  
Laser Desorption Mass Spectrometry ◽  
X Ray

Ambiguities in amino acid sequences are a potential problem in X-ray crystallographic studies of proteins. Amino acid side chains often cannot be reliably identified from the electron density. Many protein crystal structures that are now being solved are simple variants of a known wild-type structure. Thus, cloning artifacts or other untoward events can readily lead to cases in which the proposed sequence is not correct. An example is presented showing that mass spectrometry provides an excellent tool for analyzing suspected errors. The X-ray crystal structure of an insertion mutant of Staphylococcal nuclease has been solved to 1.67 Å resolution and refined to a crystallographic R value of 0.170 [Keefe & Lattman (1992). In preparation]. A single residue has been inserted in the C-terminal α helix. The inserted amino acid was believed to be an alanine residue, but the final electron density maps strongly indicated that a glycine had been inserted instead. To confirm the observations from the X-ray data, matrix-assisted laser desorption mass spectrometry was employed to verify the glycine insertion. This mass spectrometric technique has sufficient mass accuracy to detect the methyl group that distinguishes glycine from alanine and can be extended to the more common situation in which crystallographic measurements suggest a problem with the sequence, but cannot pinpoint its location or nature.

scholarly journals 14C INTERCOMPARISON EXERCISE ON BONES AND IVORY SAMPLES: IMPLICATIONS FOR FORENSICS

Radiocarbon ◽  
2021 ◽  
pp. 1-12
Author(s):  
G Quarta ◽  
M Molnár ◽  
I Hajdas ◽  
L Calcagnile ◽  
I Major ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
International Atomic Energy Agency ◽  
Accelerator Mass Spectrometry ◽  
Reference Curve ◽  
Nuclear Testing ◽  
Energy Agency ◽  
Widespread Application ◽  
Intercomparison Exercise ◽  
High Degree ◽  
Data Calibration

ABSTRACT The application of accelerator mass spectrometry radiocarbon (AMS 14C) dating in forensics is made possible by the use of the large excursion of the 14C concentration in the post-WWII terrestrial atmosphere due to nuclear testing as a reference curve for data calibration. By this approach high-precision analyses are possible on samples younger than ∼70 years. Nevertheless, the routine, widespread application of the method in the practice of forensics still appears to be limited by different issues due to possible complex interpretation of the results. We present the results of an intercomparison exercise carried out in the framework of an International Atomic Energy Agency (IAEA) CRP-Coordinated Research Project between three AMS laboratories in Italy, Hungary, and Switzerland. Bone and ivory samples were selected with ages spanning from background (>50 ka) to 2018. The results obtained allow us to assess the high degree of reproducibility of the results and the remarkable consistency of the experimental determinations.

scholarly journals 4-vinylpyridine derivatives: Protonation, methylation and silver(I) coordination chemistry

2021 ◽  
pp. 174751982198965
Author(s):  
Guoqi Zhang
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Coordination Chemistry ◽  
Elemental Analysis ◽  
Silver Complex ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pyridine Moiety ◽  
New Compounds

( E)-4-[2-(Pyridin-4-yl)vinyl]benzaldehyde, containing both a 4-vinylpyridine and an aldehyde functionality, is utilized to develop new, highly conjugated chalcone compounds and a bis-Schiff base azine compound. The chalcone-containing compounds are further explored for their protonation, methylation and silver(I) coordination chemistry using the pyridine moiety. In parallel, a cyano-containing analogue, ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile is also synthesized and studied for its silver(I) coordination chemistry. These new compounds are fully characterized by mass spectrometry, elemental analysis and spectroscopic techniques. The methylated product of ( E)-1-(9-anthryl)-3-{4-[2-(pyridin-4-yl)vinyl]phenyl}prop-2-en-1-one and a silver complex of ( E)-4-[2-(pyridin-4-yl)vinyl]benzonitrile are structurally determined by X-ray crystallography.

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