Building Water Models, A Different Approach

Simplified, classical models of water are an integral part of atomistic molecular simulations, especially in biology and chemistry where hydration effects are critical. Yet, despite several decades of effort, these models are still far from perfect. Presented here is an alternative approach to constructing point charge water models - currently, the most commonly used type. In contrast to the conventional approach, we do not impose any geometry constraints on the model other than symmetry. Instead, we optimize the distribution of point charges to best describe the "electrostatics" of the water molecule, which is key to many unusual properties of liquid water. The search for the optimal charge distribution is performed in 2D parameter space of key lowest multipole moments of the model, to find best fit to a small set of bulk water properties at room temperature. A virtually exhaustive search is enabled via analytical equations that relate the charge distribution to the multipole moments. The resulting "optimal" 3-charge, 4-point rigid water model (OPC) reproduces a comprehensive set of bulk water properties significantly more accurately than commonly used rigid models: average error relative to experiment is 0.76%. Close agreement with experiment holds over a wide range of temperatures, well outside the ambient conditions at which the fit to experiment was performed. The improvements in the proposed water model extend beyond bulk properties: compared to the common rigid models, predicted hydration free energies of small molecules in OPC water are uniformly closer to experiment, root-mean-square error < 1kcal/mol

Degenerate Gaugino Mass Region and Mono-Boson Collider Signatures

Mathematical and Physical Sciences: 3rd Place (The Ohio State University Edward F. Hayes Graduate Research Forum)We propose here a program of searches for degenerate electro-weakinos in various final state search topologies. In particular we emphasize the usefulness of searching for mass degenerate charginos and neutralinos in the mono-Z search channel. We demonstrate that the mono-Z search supersedes the mono-jet and mono-photon search topologies and present arguments using effective operators to explain why mono Z searches can succeed where mono-jet and mono-photon searches have failed.No embarg

Technological Progression and Procedures in Microsoft Kinect Sensor

Kinect is a sensor technology capable of tracking any environmental phenomena by sensing it for identification. And it plays a unique and vital role in the study of identification as it recognizes every object using the sensor. However, Kinect sensors track and sense objects using their color and data with the enhancement of tracking various actions and postures. Improvisations are inhabited within the technology based on identity, digitalization, alpha channels, depth of color and sensors in Autism research. Major concepts of Kinect sensor and its enhancement features are surveyed in this paper