The photodissociation spectroscopy and dynamics of the methoxy radical Ã(A1) r X̃(2E) transition have been investigated using fast radical beam photofragment translational spectroscopy. The à state of both CH3O and CD3O is observed to predissociate via curve crossings with one or more repulsive electronic states. The photofragment yield spectrum consists of the C-O stretch progression and combin...

Free cooling of granular materials is analyzed on the basis of a pseudoLiouville operator. Exchange of translational and rotational energy requires surface roughness for spherical grains, but occurs for non-spherical grains, like needles, even if they are perfectly smooth. Based on the assumption of a homogeneous cooling state, we derive an approximate analytical theory. It predicts that coolin...

We report high resolution state-to-state time-of-flight (TOF) measurements for scattering of HCl(v=2, J=1) from a Au(111) single crystal surface for both vibrationally elastic (v=2-->2) as well as inelastic (v=2-->1) channels at seven incidence energies between 0.28 and 1.27 eV. The dependences of the TOF results on final HCl rotational state and surface temperature are also reported. The trans...

Background: This study evaluates dosimetric and spatial variations in inter–fraction applicator positioning in high dose rate (HDR) brachytherapy. Materials and Methods: This study includes 25 retrospective patients of carcinoma of the cervix. Each patient received 5 fractions of HDR intracavitary brachytherapy. High Risk-Clinical Target Volume (HR-CTV) were drawn on CT images. First impl...

Living cells maintain a steady state of biochemical reaction rates by exchanging energy and matter with the environment. These exchanges usually do not occur in in vitro systems, which consequently go to chemical equilibrium. This in turn has severely constrained the complexity of biological networks that can be implemented in vitro. We developed nanoliter-scale microfluidic reactors that excha...

Limit-periodicity describes structures without translational symmetry but which are the union of infinitely many patterns with translational symmetry on increasing scales. Because of its relative simplicity, the limit-perodic Socolar-Taylor tiling offers an ideal system to probe the physical consequences of this distinct type of order. In this undergraduate thesis, we construct a two-deminsiona...

The origin of pairing in a superconductor resides in the underlying normal state. In the cuprate high-temperature superconductor YBa(2)Cu(3)O(y) (YBCO), application of a magnetic field to suppress superconductivity reveals a ground state that appears to break the translational symmetry of the lattice, pointing to some density-wave order. Here we use a comparative study of thermoelectric transpo...

The reactions of ground state Cl((2)P(3/2)) atoms with neopentane and tetramethylsilane have been studied at collision energies of 7.9+/-2.0 and 8.2+/-2.0 kcal mol(-1), respectively. The nascent HCl(v=0,J) products were probed using resonance enhanced multiphoton ionization spectroscopy combined with velocity map imaging (VMI) to determine the rotational level population distributions, differen...

PII proteins are pivotal players in the control of nitrogen metabolism in bacteria and archaea, and are also found in the plastids of plants. PII proteins control the activities of a diverse range of enzymes, transcription factors and membrane transport proteins, and their regulatory effect is achieved by direct interaction with their target. Many, but by no means all, PII proteins are subject ...

At equilibrium, empty ribosomes freely transit between the rotated and un-rotated states. In the cell, the binding of two translation elongation factors to the same general region of the ribosome stabilizes one state over the other. These stabilized states are resolved by expenditure of energy in the form of GTP hydrolysis. A prior study employing mutants of a late assembling peripheral ribosom...