Electron Beam Induced Current Analysis of Voltage Breakdown Sites in Thin MOS Oxides

Voltage breakdown sites on thin (\u3c 100 A) MOS capacitors have been identified by the electron beam induced current (EBIC) technique, using a scanning electron microscope (SEM). EBIC spots coincide with voltage breakdown locations and their image intensity can be changed by varying the applied bias or the electron beam accelerating voltage. Total current and the number of EBIC spots were the same in both accumulation and depletion conditions for a fixed beam potential and bias voltage. This suggests that the observed EBIC spots were due to defects in the oxide only. This EBIC method for identifying defects has been found very useful in characterizing thin MOS oxides

Some economic benefits of a synchronous earth observatory satellite

An analysis was made of the economic benefits which might be derived from reduced forecasting errors made possible by data obtained from a synchronous satellite system which can collect earth observation and meteorological data continuously and on demand. User costs directly associated with achieving benefits are included. In the analysis, benefits were evaluated which might be obtained as a result of improved thunderstorm forecasting, frost warning, and grain harvest forecasting capabilities. The anticipated system capabilities were used to arrive at realistic estimates of system performance on which to base the benefit analysis. Emphasis was placed on the benefits which result from system forecasting accuracies. Benefits from improved thunderstorm forecasts are indicated for the construction, air transportation, and agricultural industries. The effects of improved frost warning capability on the citrus crop are determined. The benefits from improved grain forecasting capability are evaluated in terms of both U.S. benefits resulting from domestic grain distribution and U.S. benefits from international grain distribution

Critical dynamics in thin films

Critical dynamics in film geometry is analyzed within the field-theoretical approach. In particular we consider the case of purely relaxational dynamics (Model A) and Dirichlet boundary conditions, corresponding to the so-called ordinary surface universality class on both confining boundaries. The general scaling properties for the linear response and correlation functions and for dynamic Casimir forces are discussed. Within the Gaussian approximation we determine the analytic expressions for the associated universal scaling functions and study quantitatively in detail their qualitative features as well as their various limiting behaviors close to the bulk critical point. In addition we consider the effects of time-dependent fields on the fluctuation-induced dynamic Casimir force and determine analytically the corresponding universal scaling functions and their asymptotic behaviors for two specific instances of instantaneous perturbations. The universal aspects of nonlinear relaxation from an initially ordered state are also discussed emphasizing the different crossovers that occur during this evolution. The model considered is relevant to the critical dynamics of actual uniaxial ferromagnetic films with symmetry-preserving conditions at the confining surfaces and for Monte Carlo simulations of spin system with Glauber dynamics and free boundary conditions.Comment: 64 pages, 21 figure

Characterization of a urea induced molten globule intermediate state of glutaminyl-tRNA synthetase from Escherichia coli

The urea-induced unfolding of glutaminyl-tRNA synthetase, a multidomain protein, has been studied by equilibrium and kinetic methods, using chemical modification, fluorescence, and CD spectroscopy. The far-UV CD, fluorescence, and sulfhydryl reactivity clearly demonstrated the existence of a stable intermediate state at around 2 M urea. The intermediate showed higher binding of 1-anilino-8-naphthalenesulfonic acid. Furthermore, near-UV CD study of the intermediate showed significantly disrupted tertiary structure with only a small change in the secondary structure, which is a characteristic of molten globule states. The activation energies (ΔG++) calculated from unfolding kinetics monitored by CD and fluorescence suggest that the intermediate state may be separated from the native and the unfolded state by high activation energy barriers