On the Electronic Spectroscopy of Closed Shell Cations Derived From Resonance Stabilized Radicals: Insights From Theory and Franck-Condon Analysis

Context. Recent attention has been directed on closed-shell aromatic cations as potential carriers of the diffuse interstellar bands. The spectra of mass-selected, matrix-isolated benzylium, and tropylium cations were recently reported. The visible spectrum of benzylium exhibits a large Franck-Condon (FC) envelope, inconsistent with diffuse interstellar band carriers. Aims. We perform a computational analysis of the experimentally studied benzylium spectrum before extending the methods to a range of larger, closed-shell aromatic cations to determine the potential for this class of systems as diffuse interstellar band carriers. Methods. Density functional theory (DFT), time-dependant ((TD)DFT), and multi-configurational self-consistent field second-order perturbation theory (MRPT2) methods in concert with multidimensional FC analysis is used to model the benzylium spectrum. These methods are extended to larger closed-shell aromatic hydrocarbon cations derived from resonance-stabilized radicals, which are predicted to show strong S0 → Sn transitions in the visible region. The ionization energies of a range of these systems are also calculated by DFT. Results. The simulated benzylium spectrum was found to yield excellent agreement with the experimental spectrum showing an extended progression in a low frequency (510 cm-1) ring distortion mode. The FC progression was found to be significantly quenched in the larger species: 1-indanylium, 1-naphthylmethylium, and fluorenium. Excitation and ionization energies of the closed-shell cations were found to be consistent with diffuse interstellar band carriers, with the former lying in the visible range and the latter straddling the Lyman limit in the 13−14 eV range. Conclusions. Large closed-shell polycyclic aromatic hydrocarbon cations remain viable candidate carriers of the diffuse interstellar bands

The Effect of NAG–thiazoline on Morphology and Surface Hydrophobicity of Escherichia Coli

The β-hexosaminidase inhibitor and structural analog of the putative oxazolium reaction intermediate of lytic transglycosylases, N-acetylglucosamine thiazoline (NAG–thiazoline), was synthesized in 46% overall yield and tested as an inhibitor of Escherichia coli growth. NAG–thiazoline, at concentrations up to 1 mg/ml, was not found to affect the viability of E. coli DH5α

Letter from W. T. Reid to John Muir, 1906 Jun 3.

BELMONT SCHOOL, Belmont, Cal., June 3, 1906.Dear Mr. Muir:-You will remember that some years ago I had a scheme for a kind of colony at Tahoe. That has lapsed, but meanwhile we have gone ahead and built us a house there, which we are enjoying immensely. I had hardly hoped to get up this summer, after the fire, but it has come about that we are going to be able to have perhaps a month or two there after all. Can you not run up and give us two or three weeks of your time? I know you protest against comfort, but we shall give you your choice of a comfortable room and plenty to eat, or you may make yourself as uncomfortable as you like. We hope to go in about a week. Cannot you join us, and if so, when? I think I remember that you have a daughter. We should be very glad indeed to have you bring her along with you.Very truly yoursm[illegible]0373

Fluctuating surface-current formulation of radiative heat transfer: theory and applications

We describe a novel fluctuating-surface current formulation of radiative heat transfer between bodies of arbitrary shape that exploits efficient and sophisticated techniques from the surface-integral-equation formulation of classical electromagnetic scattering. Unlike previous approaches to non-equilibrium fluctuations that involve scattering matrices---relating "incoming" and "outgoing" waves from each body---our approach is formulated in terms of "unknown" surface currents, laying at the surfaces of the bodies, that need not satisfy any wave equation. We show that our formulation can be applied as a spectral method to obtain fast-converging semi-analytical formulas in high-symmetry geometries using specialized spectral bases that conform to the surfaces of the bodies (e.g. Fourier series for planar bodies or spherical harmonics for spherical bodies), and can also be employed as a numerical method by exploiting the generality of surface meshes/grids to obtain results in more complicated geometries (e.g. interleaved bodies as well as bodies with sharp corners). In particular, our formalism allows direct application of the boundary-element method, a robust and powerful numerical implementation of the surface-integral formulation of classical electromagnetism, which we use to obtain results in new geometries, including the heat transfer between finite slabs, cylinders, and cones

Reduced Dynamics from the Unitary Group to Some Flag Manifolds : Interacting Matrix Riccati Equations

In this paper we treat the time evolution of unitary elements in the N level system and consider the reduced dynamics from the unitary group U(N) to flag manifolds of the second type (in our terminology). Then we derive a set of differential equations of matrix Riccati types interacting with one another and present an important problem on a nonlinear superposition formula that the Riccati equation satisfies. Our result is a natural generalization of the paper {\bf Chaturvedi et al} (arXiv : 0706.0964 [quant-ph]).Comment: Latex ; 13 pages ; no figur

Letter from W. T. Reid to John Muir, 1882 Jan 25.

[letterhead] Jan. 25, 1882.Dear Mr Muir:May I not put you down for a lecture on Glacial action in Cal. or such other wording as you may choose, or such other subject as you may choose, for March 8. and a lecture on Alaska for March 15? I wish to get the time filled as for ahead as possible lest I find myself short of speakers. If you can come at wither of the dates mentioned or at both dates be kind enough to let me know, and also the wording of your subject or subjects.Very truly yours W. T. Reid.0106

Letter from W. T. Reid to John Muir, 1894 Sep 26.

[letterhead]Sept. 26, \u2794Dear Mr Muir,I am sorry that this notice goes out so late but I hope that it will reach you in time to bring you to the city. I am quite desirous of settling the thing up as far as we may at this meeting. You are always so cordial & ready to act that I shall miss you if you are not present. In a previous letter you said that you would like a couple of lots on the lake front for Mrs Muir & and that beyond that you didn\u27t care what you had. That you would take what is left. Now I am not quite certain just what you mean. Do you wish to take a third or a fourth or a fifth of the whole plot in case you may? I shall be quite glad01848 if you do for I dont care whether we run up to a large number or not. We shall wish to keep the 45 acres as free from the axe or the grubbing hoe as we can. But come up if you can.Yrs trulyW. T. Reid[in margin: Reid Prof

Letter from W. T. Reid to John Muir, 1894 May 21.

[letterhead]May 21, \u2794Dear Mr. Muir,How deep are you willing to go into the Tahoe lots? I rather hope that those of us who are now in it may take up all the lots & then sell them only to persons whom we all wish very much to have come in. It would be a good thing if a fair proportion of the whole coujld be held for the pubic good & and so keep our numbers down. However, it if seems best to all I am inclined to think that the holding will not be a bad investment. I should prefer to have you have a large holding rather than any one else simply because of your wish to keep the place as [illegible] as possible. Still I do not of course wish to make you feel under any pressure But let me know your wishes. I10090 think that Olney will probably take some extra lots. I shall take four & probably Garber will take some. I wish that the whole plot would be take by those now in.Very truly yours,W. T. Rei

Letter from W. T. Reid to [John Muir], 1894 May 19.

[letterhead]May 19, 1894Dear Sir:At the late called meeting of those interested in the plan of a summer resort at Lake Tahoe it was voted as probably the most equitable and satisfactory way of disposing of the 45 acres that have been bought for the colony;1st, to sell lots outright, with no restrictions & no obligations upon the buyer save that he is not to sell again except to a person who has been admitted to the association by un[an]imous consent. If any co-operative plan is adopted membership in it is wholly voluntary.2nd, to have a driveway some 100 feet wide along the shore of the Lake, and such other driveways as seem best, and then have the remainder of the tract divided into 45 equal lots a little less than an acre each.3rd, to sell these lots to the original subscribers or charter members at $36.50 a lot, &01816 give them the privilege of taking up the entire purchase.4th, to distribute the lots in whatever way may be determined by the charter members.It is hoped that some of the members may feel disposed to take several lots and either hold them for the public good without expectation of selling, or to sell them to future members at perhaps double the rate paid for them.Will you do me the favor to let me know as soon as convenient how many lots you wish to subscribe for. A plot of the purchase with the lots numbered ready for distribution is in preparation.Purchasers are, or course, at liberty to occupy the tract at once. I and some other purchasers will spend a portion of the present summer there.Very truly yours,W. R. Reid

Accurate measurement of telemetry performance

Performance of high rate telemetry stations used in the Deep Space Network is verified. Measurement techniques are discussed