Using a low-energy, three stage, differentially pumped ion
accelerator, similar to that used by Hagstrom for Auger electron
ejection studies, permits, with the application of radiotracer methods,
a new approach to the study of low energy sputtering.
The experimental approach consisted of pumping down the
experimental tube to 10⁻⁹ torr,...
Drosophila suzukii (Diptera: Drosophilidae) is an insect of global concern that causes serious damage to soft-skinned fruits. D. suzukii is widespread in North America, South America, Europe, and Asia and is listed as an invasive pest with strict quarantine protocols governing import and export. Given the damage caused by D....
2 -acetylaminofluorene -induced hepatocarcinogenesis in rats
proceeds in stages of initiation and promotion, similar to experimental
systems, in mouse skin. In this study promoters of liver
tumorigenesis, phenobarbital, DDT and butylated hydroxytoluene
(BHT), were compared to non-promoters, amobarbital, diphenylhydantoin
(DPH) and benz(a)anthracene (BA), for their ability to
cause liver growth...
The education (particularly graduate education) of Americans
who were active in astronomical research between 1876 and 1941
is assessed for its effectiveness in preparing the astronomers for
careers in research. This period contains three dynamic changes:
the growth of American astronomy in becoming the world's leading
community of astronomers, the...
John Wesley Powell worked actively for public land system
reform while a director of geographical and geological surveys in
the West from 1869 to 1894. Although this has won him acclaim as a
conservationist, the basis of Powell's linkage of reform with
scientific work is poorly understood.
A study of...
This study traces the historical foundations of the concept of
constant ionic proportionality and the equation (Salinity [S%₀] = 1.805
Chlorinity [Cl%₀] + 0.030) which has been in general use in oceanography
since 1902 until 1969 and which is based upon this constancy,
The notion that the constituents present in...
This analysis concerns the life and scientific work of Henry
Augustus Rowland (1848-1901), organizer and the first chairman of
the physics department at The Johns Hopkins University in 1876.
Special materials used in this research included three pieces of
Rowland's experimental apparatus which are extant in the Smithsonian
Institution Division...
Cognitive self-regulation and the behavioral manifestations of cognitive self-regulation are important aspects of school readiness, yet less is known about the variation in measurement modalities within children. In this dissertation, two studies examined the makeup, antecedents, and consequents of constellations of cognitive self-regulation (CSR) measures around the transition to formal...
Individuals with mild developmental disabilities have
traditionally been excluded from full participation in
their career decision making due to the stereotyping of
their perceived incompetence. This view forms a mind-set
or stigma that is recognized as the disability myth.
This study initially addressed the vocational
development of individuals with mild...