Experimental and Archaeological Verification of an Index of Retouch for Hafted Bifaces

2006 ◽  
Vol 71 (4) ◽  
pp. 743-757 ◽  
Author(s):  
William Andrefsky
Keyword(s):  
Experimental Data ◽  
Land Use ◽  
Stone Tools ◽  
Stone Tool ◽  
Data Set ◽  
X Ray ◽  
Projectile Points

The relative amount of retouch on stone tools is central to many archaeological studies linking stone tool assemblages to broader issues of human social and economic land-use strategies. Unfortunately, most retouch measures deal with flake and blade tools and few (if any) have been developed for hafted bifaces and projectile points. This paper introduces a new index for measuring and comparing amount of retouch on hafted bifaces and projectile points that can be applied regardless of size or typological variance. The retouch index is assessed initially with an experimental data set of hafted bifaces that were dulled and resharpened on five occasions. The retouch index is then applied to a hafted biface assemblage made from tool stone that has been sourced by X-Ray Fluorescence (XRF). Results of both assessments show that the hafted biface retouch index (HRI) is effective for determining the amount of retouch and the degree to which the hafted bifaces have been curated.

scholarly journals The anisotropy in the optical constants of quartz crystals for soft X-rays

2021 ◽  
Vol 54 (2) ◽  
Author(s):  
A. Andrle ◽  
P. Hönicke ◽  
J. Vinson ◽  
R. Quintanilha ◽  
Q. Saadeh ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Refractive Index ◽  
Optical Constants ◽  
Quartz Crystal ◽  
Crystal Surface ◽  
X Rays ◽  
Data Set ◽  
Quartz Crystals ◽  
X Ray

The refractive index of a y-cut SiO2 crystal surface is reconstructed from orientation-dependent soft X-ray reflectometry measurements in the energy range from 45 to 620 eV. Owing to the anisotropy of the crystal structure in the (100) and (001) directions, a significant deviation of the measured reflectance at the Si L 2,3 and O K absorption edges is observed. The anisotropy in the optical constants reconstructed from these data is also confirmed by ab initio Bethe–Salpeter equation calculations for the O K edge. This new experimental data set expands the existing literature data for quartz crystal optical constants significantly, particularly in the near-edge regions.

Experimental Use of Clovis Weaponry and Tools on African Elephants

1989 ◽  
Vol 54 (4) ◽  
pp. 766-784 ◽  
Author(s):  
George C. Frison
Keyword(s):  
National Park ◽  
Stone Tools ◽  
Stone Tool ◽  
Archaeological Sites ◽  
African Elephants ◽  
Projectile Points ◽  
Chipped Stone ◽  
Positive Statements ◽  
Hwange National Park ◽  
Experimental Use

Clovis projectile points and chipped-stone tools have been recovered in a number of archaeological sites in the New World, but these cannot be tested on mammoths, which we know from the archaeological evidence Clovis hunters were able to procure. Extensive culling of elephants in Hwange National Park in Zimbabwe provided the necessary animals to test replicas of Clovis tools and weaponry. The experiments leave little doubt that Clovis projectile points can inflict lethal wounds on African elephants and that simple stone tools will perform the necessary butchering tasks. The physiology of mammoths and elephants is similar enough to make positive statements on the potential of this kind of stone-tool and weaponry assemblage, but we will never be able to compare elephant and mammoth behavior directly.

Difference Fourier Analysis of Glucose Embedded and Frozen Hydrated Purple Membrane

1982 ◽  
Vol 40 ◽  
pp. 74-75
Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser
Keyword(s):  
Purple Membrane ◽  
Data Set ◽  
High Resolution Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Fourier Techniques ◽  
Versus Protein ◽  
The Difference ◽  
Difference Fourier ◽  
Ideal Method

Although difference Fourier techniques are standard in X-ray crystallography it has only been very recently that electron crystallographers have been able to take advantage of this method. We have combined a high resolution data set for frozen glucose embedded Purple Membrane (PM) with a data set collected from PM prepared in the frozen hydrated state in order to visualize any differences in structure due to the different methods of preparation. The increased contrast between protein-ice versus protein-glucose may prove to be an advantage of the frozen hydrated technique for visualizing those parts of bacteriorhodopsin that are embedded in glucose. In addition, surface groups of the protein may be disordered in glucose and ordered in the frozen state. The sensitivity of the difference Fourier technique to small changes in structure provides an ideal method for testing this hypothesis.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

EXPERIMENTAL DATA SET NO. 24: PHASE DISTRIBUTION IN BUBBLY FLOW

1992 ◽  
Vol 6 (1-4) ◽  
pp. 257-301 ◽  
Author(s):  
Akimi Serizawa ◽  
Isao Kataoka ◽  
Itaru Michiyoshi
Keyword(s):  
Experimental Data ◽  
Phase Distribution ◽  
Bubbly Flow ◽  
Data Set
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