Aboriginal Thermal Alteration of a Central Pennsylvania Jasper: Analytical and Behavioral Implications

1982 ◽  
Vol 47 (3) ◽  
pp. 526-544 ◽  
Author(s):  
Debra L. Schindler ◽  
James W. Hatch ◽  
Conran A. Hay ◽  
Richard C. Bradt
Keyword(s):  
Heat Treatment ◽  
Thermal Processing ◽  
Color Change ◽  
Bald Eagle ◽  
Thermal Alteration ◽  
Central Pennsylvania ◽  
Red Color ◽  
Lithic Artifacts ◽  
Physical Changes

The aboriginal thermal processing of Bald Eagle Jasper in Central Pennsylvania is described in terms of the chemical and physical changes that occur in this material. Heat treatment is shown to transform the jasper's geothite component to hematite and to improve its workability by reducing its fracture toughness by one-half. This is accompanied by a yellow to red color change. The role of thermal alteration in the local lithic technology is inferred from laboratory heating experiments and from an analysis of lithic artifacts from the Houserville Site (36 Ce 65), a jasper workshop. The prehistoric utilization of this material is analyzed from a regional perspective. The results have implications for aboriginal social organization in Central Pennsylvania.

Comments on Studies of Thermal Alteration of Central Pennsylvania Jasper

1984 ◽  
Vol 49 (1) ◽  
pp. 168-173 ◽  
Author(s):  
Leland W. Patterson
Keyword(s):  
Heat Treating ◽  
Bald Eagle ◽  
Thermal Alteration ◽  
Fracture Properties ◽  
Patterns Of Use ◽  
Central Pennsylvania

Comments are offered on heat treating experiments and archaeological studies by Schindler, Hatch, Hay and Bradt concerning Bald Eagle Jasper from central Pennsylvania. Their conclusions concerning aboriginal patterns of use of Bald Eagle Jasper are critiqued. Their explanations for the effects of thermal alteration on jasper fracture properties are also questioned.

Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

1991 ◽  
Vol 49 ◽  
pp. 604-605
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D. Matlock
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stress Corrosion Cracking ◽  
Stainless Steels ◽  
Deformation Twin ◽  
Austenitic Stainless Steels ◽  
Carbide Precipitation ◽  
Strain Induced Martensite ◽  
Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

Preferred Orientations for Sol-Gel Derived Plzt Thin Layers

1993 ◽  
Vol 310 ◽  
Author(s):  
Toshihiko Tani ◽  
Zhengkui Xu ◽  
David A. Payne
Keyword(s):  
Heat Treatment ◽  
Surface Energy ◽  
Sol Gel ◽  
Nucleation And Growth ◽  
Thin Layers ◽  
Energy Conditions ◽  
Chemical Characteristics ◽  
Interfacial Chemistry ◽  
Si Substrates

AbstractPLZT thin layers were deposited onto various substrates by sol-gel methods, and crystallized under different conditions and substrate treatments. Relationships are given for the chemical characteristics of the substrate's surface and the preferred orientations which develop on heat treatment. A preferred (111) orientation always developed for perovskite crystallized on Pt layers which contained Ti on the surface. This was attributed to the formation of Pt3Ti and the role of heteroepitaxial nucleation and growth sites. In addition, a preferred (100) orientation was also obtained on unannealed Pt/Ti/SiO2/Si substrates which were free of Ti on the surface. This was attributed to self-textured growth with flat faces striving for minimum surface energy conditions. The results are discussed in terms of the importance of interfacial chemistry on the control of texture for crystallization of PLZT thin layers on coated substrates.

A multi-scale approach to identify the role of heat treatment, milk protein composition and starter culture on the gel formation and the texture defects of acid milk gel

2018 ◽  
Vol 85 ◽  
pp. 299-310 ◽  
Author(s):  
An Thi-Binh Nguyen ◽  
Michaël Nigen ◽  
Luciana Jimenez ◽  
Hassina Ait-Abderahim ◽  
Charles Cunault ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Milk Protein ◽  
Starter Culture ◽  
Protein Composition ◽  
Gel Formation ◽  
Multi Scale ◽  
Acid Milk Gel

Comparison of the color and weight change in Paulownia tomentosa and Pinus koraiensis wood heat-treated in hot oil and hot air

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5574-5585
Author(s):  
Intan Fajar Suri ◽  
Jong Ho Kim ◽  
Byantara Darsan Purusatama ◽  
Go Un Yang ◽  
Denni Prasetia ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Color Change ◽  
Treated Wood ◽  
Pinus Koraiensis ◽  
Weight Changes ◽  
Paulownia Tomentosa ◽  
Wood Color ◽  
Color Changes ◽  
Hot Air ◽  
Heat Treated

Color changes were tested and compared for heat-treated Paulownia tomentosa and Pinus koraiensis wood treated with hot oil or hot air for further utilization of these species. Hot oil and hot air treatments were conducted at 180, 200, and 220 °C for 1, 2, and 3 h. Heat-treated wood color changes were determined using the CIE-Lab color system. Weight changes of the wood before and after heat treatment were also determined. The weight of the oil heat-treated wood increased considerably but it decreased in air heat-treated wood. The oil heat-treated samples showed a greater decrease in lightness (L*) than air heat-treated samples. A significant change in L* was observed in Paulownia tomentosa. The red/green chromaticity (a*) of both wood samples increased at 180 and 200 °C and slightly decreased at 220 °C. The yellow/blue chromaticity (b*) in both wood samples increased at 180 °C, but it rapidly decreased with increasing treatment durations at 200 and 220 °C. The overall color change (ΔE*) in both heat treatments increased with increasing temperature, being higher in Paulownia tomentosa than in Pinus koraiensis. In conclusion, oil heat treatment reduced treatment duration and was a more effective method than air heat treatment in improving wood color.

The Historical Change in the Role of the Two Hungarian Words for Red (Piros and Vörös) and Their Visual Semantics

2020 ◽  
Vol 65 (1) ◽  
pp. 285-302
Author(s):  
Beáta Bálizs
Keyword(s):  
Research Methods ◽  
International Research ◽  
Historical Change ◽  
Color Terms ◽  
Color Term ◽  
Linguistic Research ◽  
Red Color ◽  
History Of ◽  
Hungarian Language

The present study summarizes the key findings of a multi-year interdisciplinary investigation, performed using specific (ethnographic, anthropological, and linguistic) research methods, into the two color terms mentioned in the title. Originally intended as empirical research involving all Hungarian color terms and individual community-dependent relationships with colors, it was eventually supplemented by a text-based examination of the history of the color terms piros and veres/vörös. A further objective was to answer questions raised in the course of international research concerning the reason for the existence of two color terms with similar meanings in the Hungarian language to denote the red color range. Earlier studies had already suggested that the modern use of vörös, which has more ancient roots in the Hungarian language, may be related to the fact that this color term was previously used more extensively. However, the present research is unique in demonstrating the substantial changes that have taken place in the Hungarian language in relation to the role and meaning of these color terms. It has already been established that the two color terms switched places historically, and that piros today fulfills precisely the same function that for centuries belonged to veres/vörös, until the color term piros began to gain ground in the 19th century.

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