3 Matching Results

Search Results

Advanced search parameters have been applied.

Molecular dynamics of membrane proteins.

Description: Understanding the dynamics of the membrane protein rhodopsin will have broad implications for other membrane proteins and cellular signaling processes. Rhodopsin (Rho) is a light activated G-protein coupled receptor (GPCR). When activated by ligands, GPCRs bind and activate G-proteins residing within the cell and begin a signaling cascade that results in the cell's response to external stimuli. More than 50% of all current drugs are targeted toward G-proteins. Rho is the prototypical member of the class A GPCR superfamily. Understanding the activation of Rho and its interaction with its Gprotein can therefore lead to a wider understanding of the mechanisms of GPCR activation and G-protein activation. Understanding the dark to light transition of Rho is fully analogous to the general ligand binding and activation problem for GPCRs. This transition is dependent on the lipid environment. The effect of lipids on membrane protein activity in general has had little attention, but evidence is beginning to show a significant role for lipids in membrane protein activity. Using the LAMMPS program and simulation methods benchmarked under the IBIG program, we perform a variety of allatom molecular dynamics simulations of membrane proteins.
Date: October 1, 2004
Creator: Woolf, Thomas B. (Johns Hopkins University School of Medicine, Baltimore, MD); Crozier, Paul Stewart & Stevens, Mark Jackson
Partner: UNT Libraries Government Documents Department

Update: Effective Load-Carrying Capability of Photovoltaics in the United States; Preprint

Description: This paper provides an update on the U.S. distribution of effective load-carrying capability (ELLC) for photovoltaics by analyzing recent load data from 39 U.S. utilities and time-coincident output of PV installations simulated from high-resolution, time/site-specific satellite data. Results show that overall regional trends identified in the early 1990s remain pertinent today, while noting a significant increase in PV ELCC in the western and northern United States, and a modest decrease in the central and eastern United States.
Date: June 1, 2006
Creator: Perez, R.; Margolis, R.; Kmiecik, M.; Schwab, M. & Perez, M.
Partner: UNT Libraries Government Documents Department

Very Large-Scale Deployment of Grid-Connected Solar Photovoltaics in the United States: Challenges and Opportunities; Preprint

Description: This paper analyzes the potential for solar photovoltaics (PV) to be deployed on a very large scale and provide a large fraction of a system's electricity. It explicitly examines how the hourly availability of PV interacts with the limited flexibility of traditional electricity generation plants. The authors found that, under high penetration levels and existing grid-operation procedures and rules, the system will have excess PV generation during certain periods of the year. This excess PV generation results in increased costs, which can increase dramatically when PV provides on the order of 10%-15% of total electricity demand in systems that are heavily dependent on inflexible baseload steam plants. Measures to increase penetration of PV are also discussed, including increased system flexibility, increased dispatchable load, and energy storage.
Date: April 1, 2006
Creator: Denholm, P. & Margolis, R.
Partner: UNT Libraries Government Documents Department