The accuracy of three force fields for predicting the physical properties of dimethylnitramine (DMNA) has been investigated by using molecular dynamics simulations. The Sorescu, Rice, and Thompson (SRT) (J. Phys. Chem. B 1997, 101, 798) rigid-molecule, flexible generalized AMBER (J. Comput. Chem. 2004, 25, 1157), and Smith et al. flexible force fields (J. Phys. Chem. B 1999, 103, 705) were test...

Presented here is a novel technique for the in situ calibration and measurement of friction with the atomic force microscope that can be applied simultaneously with the normal force measurement. The method exploits the fact that the cantilever sits at an angle of about 10° to the horizontal, which causes the tip or probe to slide horizontally over the substrate as a normal force run is performe...

When we manipulate objects in everyday tasks, there are variations in the shape of the grasped surfaces, and the loads that potentially destabilize the grasp include time-varying linear forces and torques tangential to the grasped surfaces. Previous studies of the control of fingertip forces for grasp stability have dealt principally with flat grip surfaces and linear force loads. Here, we stud...

We report the measurement of two new perpendicular (D2O)3 torsional bands by terahertz laser vibration–rotation–tunneling ~VRT! spectroscopy of a planar pulsed supersonic expansion. The first ~28.0 cm) band corresponds to the k562 ←0 transition, and is the lowest frequency vibrational spectrum observed for a water cluster. The second ~81.8 cm) band originates in the first excited torsional stat...

Polarizable force field has been successfully used in molecular modeling for years, especially in biological and protein simulations. In this research thesis, development of a new polarizable force field ―POSSIM (POlarizable Simulations with Second order Interaction Model) involving electrostatic polarization is described and parameters for several protein residues were produced. In this resear...

With their successful applications in handling, spraying, arc welding and other processing fields, industrial robots are gradually replacing traditional CNC machine tools to complete machining tasks due the wider working envelope higher flexibility. Aiming at chatter problem, a robotic longitudinal-torsional ultrasonic milling method with variable force coefficient is proposed this paper. Takin...

Background HA-TLS is very difficult to correct using other braces except for the Milwaukee brace (MB). Since the introduction of the MB, a major problem has been poor patient compliance due to the perception of the brace as cosmetically unacceptable. The forces applied to the spine by the MB are well illustrated by White-Panjabi (1). According to circadian biological rhythm, a sleeping person R...

Considering viscoelastic saturated soil, The transient dynamic response of an elastic pile is studied. The pile-soil system is divided into thin layers, the control equations of the soil are solved respectively by using Laplace transform. Considering the mixed boundary-value conditions at the interface of pile and soil, expression is derived to describe the relationship between the inner force ...

A new general algorithm for optimization of potential functions for protein folding is introduced. It is based upon gradient optimization of the thermodynamic stability of native folds of a training set of proteins with known structure. The iterative update rule contains two thermodynamic averages which are estimated by (generalized ensemble) Monte Carlo. We test the learning algorithm on a Len...