Aerosols that result from large injection by volcanoes of millions of tonnes of sulfur dioxide into the stratosphere have a large effect on global climate. These stratospheric aerosols decrease the net radiation reaching the earth. The loss of radiation produces a coherent climate anomaly around the world. One of these global anomalies is the El Niño/Southern Oscillation. Another anomaly associated with the decreased radiation is the decrease in monsoon rainfall. In other regions such as the Great Lakes the aerosols induce additional rainfall that shows up in later years as an increase in the levels of Lake Michigan and Lake Huron.
This historical study explores critical features in the emergence of large-scale research in America through a close examination of the founding and first decades of operation of Fermi National Accelerator Laboratory (Fermilab). Through research in documents, supplemented by oral history interviews with leading participants, the project is designed to examine, in a book-length study and articles, historical problems of ``big science,'' including: the effects on research of increased size, scope, and cost of facilities and experiments; changes in research resulting from much larger working teams, budgets, and time scales; the role of theoretical models and computer analysis in experimentation and accelerator building; and the influences of geographical concentration, national and international politics, and economic policy.
This study is oriented toward writing a scientific biography of John Bardeen set into the context of the history of solid-state physics between 1930 and 1990. Special attention is given to the discovery of the transistor in 1947 and the BCS Theory of Superconductivity in 1957.
The overall objective of this research is to improve analysis and interpretation of hydrodynamic data that have been and may be gathered as part of nuclear test ban monitoring agreements between the United States and Russia. The specific focus of current work is the influence of aspherical explosion sources and the effects of the ambient medium on the accuracy of yield estimates. The primary method used is numerical modeling of shock-wave propagation in the hydrodynamic region for geological media characteristic of nuclear test sites.
The project aims at achieving selective deposition of single atoms on surfaces with very high resolution that may reach atomic dimensions. Tunable lasers photodissociate molecules and highly excite the atomic fragments in the field of the sharp needle of a scanning tunneling microscope, which ionizes and guides the atoms to the surface.
The project focuses on the preparation and characterization of the newly discovered optically active porous silicon. The studies include topographical, compositional, structural, optical, electrical, and chemical characterizations. These characterizations are correlated with conditions of preparation and with stability under different conditions.
Using scanning tunneling microscopes augmented by laser radiation, this project aims to develop a new kind of electronics (atomic electronics), one that relies on quantum mechanics and the movement of single particles, with the purpose of one day producing devices many times faster and smaller than anything available today. In the project, atomic scale (nanometer scale)-fabricated structures will be embedded in the gate area of micron scale Si/SiO2 metal-oxide-semiconductor field effect transistors (FET) and GaAs/AlGaAs high-electron-mobility transistors.