The base Al-Zn superplastic alloy was investigated at 250°C to
determine the effect of small amounts of magnesium on mechanical
properties. Six alloys of nominal composition 0.00, 0.10, 0.25,
0.50, 0.75, and 1.00 weight percent magnesium, constant 78 weight
percent zinc, and variable 21 to 22 weight percent aluminum were...
The structure, hardness, and impact strength of high chromium
cast irons was investigated. From the Fe- Cr- C phase diagram,
a composition with 74.8 wt% Fe, 21.5 wt% Cr, and 3.7 wt% was
selected along the austenite-M₇C₃ eutectic trough. This composition
was bracketed by others with slightly different amounts of...
Some of the problems concerning the present educational programs
which confront the institutions of higher education are, reviewed.
Resources allocation is at the root of the issue.
Budgeting orientations are presented with special emphasis on
Planning Programming Budgeting Systems. PPBS is still in its
developmental stage in the field of...
A multivariable model describing the system response
(weld tensile strength of 6061-T6 aluminum) of a percussive
stud welding system as a function of five natural
(external) system variables was developed. The five natural
system variables were 1) static weight of the drop-shaft (W), 2) initial stud base height (H₀), 3)...
The omnivorous ground beetle, Pterostichus melanarius Illager (Coleoptera: Carabidae), is a ubiquitous inhabitant of western Oregon crop land. Because it is often the most abundant ground beetle, and attains densities that could lead to serious impacts on its prey sources, I sought to understand the overall diet composition, and specifically...
Aquifers are an important storage location and source of fresh groundwater. They may become polluted by a number of contaminants including mobile divalent radionuclides such as strontium-90 which is a byproduct of uranium fission. A method for remediating such divalent radionuclides is sequestration through co-precipitation into calcium carbonate. Calcium carbonate...