The effects of evolving surface contamination on spacecraft charging have been investigated through (i) ground-based measurements of the change in electron emission properties of a conducting surface undergoing contamination and (ii) modeling of the charging of such surfaces using the NASCAP code. Specifically, we studied a Au surface as adsorbed species were removed and a very thin disordered ...

Local density functional calculations are used to analyze the change of surface energy of metallic surfaces upon surface charging. We then studied the systems involving overlayers of fcc metals on Mo~111! and Mo~211!. It has been observed experimentally that some fcc overlayers can drive Mo~111! and W~111! surfaces to facet to the $211% orientation, and there is a strong correlation between the...

soil colloid particles influence soil chemical and physical properties by their surface electrical charge. with respect to the importance of this issue from both agricultural and environmental points of view, charging behavior of a kaolinite sample was studied in the ph range of 4 to 10 and at three background electrolyte concentrations, including 0.005, 0.05, 0.5 m nacl, by potentiometric titr...

Trolley dilemmas are widely used to elicit moral intuitions. Most people do not think it would be morally right to push a heavy man from a bridge, thereby killing him, in order to avoid the death of several other people. Here we empirically tested a prediction by Unger (1996) who claims that adding more options to this scenario would shift people’s intuition from the normally preferred option o...

One of the most critical barriers to widespread adoption of electric cars is the lack of charging station infrastructure. Although it is expected that a sufficient number of charging stations will be constructed eventually, due to various practical reasons they may have to be introduced gradually over time. In this paper, we formulate a multi-period optimization model based on a flow-refueling ...

We consider a model of occupational choice in large economies where individuals differ in their wealth endowment. Individuals can remain self-employed or engage in productive matches with another individual, i.e., form firms. Matches are subject to a moral hazard problem with limited liability. The division of the gains from such matches is determined by competitive forces. When the incentive p...

Scanning electron microscopy (SEM) has become a crucial tool to visualize the exterior morphology and surface structures for samples in both biology and material science. Conventional SEMs are usually limited by relative low resolution and charging effects. Carbon or metal coating is required for insulator samples to minimize charging effects. However, the coating layer can sometimes obscure mi...

Studies of the Earth with the ATS-5, ATS-6, and SCATHA spacecraft led to the development of several simple tools for predicting the potentials to be expected on a spacecraft in the space environment. These tools have been used to estimate the expected levels of worst case charging at Jupiter and Saturn for the Galileo and the Cassini spacecraft missions. This paper reviews those results and put...

We report results on the charging technique of liquid helium surface over rectangular electrodes and maximum sustainable electron density at temperatures above 1 K. Also, thermally activated escape of twodimensional electrons from the potential well has been studied as a function of various parameters like electrons density and temperature. Results provide insights into the charging process of ...

Experiments are performed pertaining to the charging of single dust particles in space due to three effects: (1) photoemission, (2) the collection of electrons from a photoemissive surface, and (3) triboelectric charging. The particles tested are 90–106 mm in diameter and include JSC-1 (lunar regolith simulant) and JSC-Mars-1 (Martian regolith simulant). Isolated conducting grains (Zn, Cu, and ...