Power flow through line l at time t Notes: We will use the term lines to mean both lines and transformers (which are modeled as a line). Thus, for lines that are not transformers τ l = 1. Additionally, notation not included in this section will be introduced in the text.
Antioxidant therapy is a promising treatment strategy for protecting DNA from the damage caused by reactive oxygen species (ROS). Here, we report new self-cyclizing antioxidant reagents that are selective for the hydroxyl radical. Our mechanistic investigation revealed that the reagents react with three equivalents of oxidant in a cascade reaction to form a bicyclic final product. Among the reagents synthesized, 1 c showed favorable properties in vitro and in cellular studies. Using As O , which triggers ROS production, we showed that 1 c prevents formation of the guanine oxidation product 2,2,4-triamino-2H-oxazol-5-one-2'-deoxyribonucleoside and lowers cellular levels of reactive oxygen. The described self-cyclizing antioxidants are efficient, flexible, and tunable reagents with the potential to limit toxic oxidative stress.
Network segmentation of a power grid's communication system is one way to make the grid more resilient to cyber attacks. We develop a novel trilevel programming model to optimally segment a grid communication system, taking into account the actions of an information technolology (IT) administrator, attacker, and grid operator. The IT administrator is given an allowance to segment existing networks, and the attacker is given a fixed budget to attack the segmented communication system in an attempt to inflict damage on the grid. Finally, the grid operator is allowed to redispatch the grid after the attack in order to minimize damage. The resulting problem is a trilevel interdiction problem, which we solve by leveraging current research in bilevel branch and bound. We demonstrate the benefits of optimal network segmentation through case studies on the 9-bus WSCC system and the 30-bus IEEE system. These examples illustrate that network segmentation can significantly reduce the threat posed by a cyber attacker with perfect knowledge of the grid.
Continuous Variables
Grid operator decisions: θ sVoltage angle at substation s p gReal power output of generator g f k Real power flow on line k l dReal power load shed at load d L Real power total load shed
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