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.

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.

Thermal Alteration of Bald Eagle Jasper: Authors' Reply to Patterson

1984 ◽  
Vol 49 (1) ◽  
pp. 173-177 ◽  
Author(s):  
Debra L. Schindler ◽  
James W. Hatch ◽  
Conran A. Hay ◽  
Richard C. Bradt
Keyword(s):  
Bald Eagle ◽  
Thermal Alteration

Patterns of use of the health care system by the elderly with mental illness

2005 ◽  
Author(s):  
Patricia Martens ◽  
◽  
Randy Fransoo ◽  
Elaine Burland ◽  
Charles Burchill ◽  
...  
Keyword(s):  
Health Care ◽  
Mental Illness ◽  
Health Care System ◽  
The Elderly ◽  
Patterns Of Use ◽  
Care System

Addictive Patterns of Use Scale

2020 ◽  
Author(s):  
Sarah E. Domoff ◽  
Ryan P. Foley ◽  
Rick Ferkel
Keyword(s):  
Patterns Of Use

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

Micromechanics Measurements Applied to Integrated Circuit Microelectronics

1997 ◽  
Vol 473 ◽  
Author(s):  
David R. Clarke
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Fracture Resistance ◽  
Interface Fracture ◽  
New Techniques ◽  
Fracture Properties ◽  
Engineered Structures ◽  
Mechanical And Fracture Properties ◽  
Interconnect Lines ◽  
Metallic Interconnect

ABSTRACTAs in other engineered structures, fracture occasionally occurs in integrated microelectronic circuits. Fracture can take a number of forms including voiding of metallic interconnect lines, decohesion of interfaces, and stress-induced microcracking of thin films. The characteristic feature that distinguishes such fracture phenomena from similar behaviors in other engineered structures is the length scales involved, typically micron and sub-micron. This length scale necessitates new techniques for measuring mechanical and fracture properties. In this work, we describe non-contact optical techniques for probing strains and a microscopic “decohesion” test for measuring interface fracture resistance in integrated circuits.

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