Microphysical, microchemical and adhesive properties of lunar material. 3: Gas interaction with lunar material

Knowledge of the reactivity of lunar material surfaces is important for understanding the effects of the lunar or space environment upon this material, particularly its nature, behavior and exposure history in comparison to terrestrial materials. Adsorptive properties are one of the important techniques for such studies. Gas adsorption measurements were made on an Apollo 12 ultrahigh vacuum-stored sample and Apollo 14 and 15 N2-stored samples. Surface area measurements were made on the latter two. Adsorbate gases used were N2, A, O2 and H2O. Krypton was used for the surface area determinations. Runs were made at room and liquid nitrogen temperature in volumetric and gravimetric systems. It was found that the adsorptive/desorptive behavior was in general significantly different from that of terrestrial materials of similar type and form. Specifically (1) the UHV-stored sample exhibited very high initial adsorption indicative of high surface reactivity, and (2) the N2-stored samples at room and liquid nitrogen temperatures showed that more gas was desorbed than introduced during adsorption, indicative of gas release from the samples. The high reactivity is a scribed cosmic ray track and solar wind damage

Microchemical, microphysical and adhesive properties of Apollo 11 and 12 Final report, 1 Aug. 1969 - 15 Mar. 1971

Gas exposure experiments of lunar soil with microchemical, microphysical, and adhesion analysi

Kinematical Analogy for Marginal Dyon Decay

We describe a kinematical analogy for the marginal decay of 1/4-BPS dyons in 4-dimensional N=4 string compactifications. In this analogy, the electric and magnetic charges play the role of spatial momenta, the BPS mass plays the role of energy, and 1/2-BPS dyons correspond to massless particles. Using SO(12,1) "Lorentz" invariance and standard kinematical formulae in particle physics, we provide simple derivations of the curves of marginal stability. We also show how these curves map into the momentum ellipsoid, and propose some applications of this analogy.Comment: 10 pages, minor revision

Towards Understanding the Structure, Dynamics and Bio-activity of Diabetic Drug Metformin

Small molecules are often found to exhibit extraordinarily diverse biological activities. Metformin is one of them. It is widely used as anti-diabetic drug for type-two diabetes. In addition to that, metformin hydrochloride shows anti-tumour activities and increases the survival rate of patients suffering from certain types of cancer namely colorectal, breast, pancreas and prostate cancer. However, theoretical studies of structure and dynamics of metformin have not yet been fully explored. In this work, we investigate the characteristic structural and dynamical features of three mono-protonated forms of metformin hydrochloride with the help of experiments, quantum chemical calculations and atomistic molecular dynamics simulations. We validate our force field by comparing simulation results to that of the experimental findings. Nevertheless, we discover that the non-planar tautomeric form is the most stable. Metformin forms strong hydrogen bonds with surrounding water molecules and its solvation dynamics show unique features. Because of an extended positive charge distribution, metformin possesses features of being a permanent cationic partner toward several targets. We study its interaction and binding ability with DNA using UV spectroscopy, circular dichroism, fluorimetry and metadynamics simulation. We find a non-intercalating mode of interaction. Metformin feasibly forms a minor/major groove-bound state within a few tens of nanoseconds, preferably with AT rich domains. A significant decrease in the free-energy of binding is observed when it binds to a minor groove of DNA.Comment: 60 pages, 24 figure

Gap equation in scalar field theory at finite temperature

We investigate the two-loop gap equation for the thermal mass of hot massless $g^2\phi^4$ theory and find that the gap equation itself has a non-zero finite imaginary part. This indicates that it is not possible to find the real thermal mass as a solution of the gap equation beyond $g^2$ order in perturbation theory. We have solved the gap equation and obtain the real and the imaginary part of the thermal mass which are correct up to $g^4$ order in perturbation theory.Comment: 13 pages, Latex with axodraw, Minor corrections, Appendix adde

Reconstructing the primordial power spectrum from the CMB

We propose a straightforward and model independent methodology for characterizing the sensitivity of CMB and other experiments to wiggles, irregularities, and features in the primordial power spectrum. Assuming that the primordial cosmological perturbations are adiabatic, we present a function space generalization of the usual Fisher matrix formalism, applied to a CMB experiment resembling Planck with and without ancillary data. This work is closely related to other work on recovering the inflationary potential and exploring specific models of non-minimal, or perhaps baroque, primordial power spectra. The approach adopted here, however, most directly expresses what the data is really telling us. We explore in detail the structure of the available information and quantify exactly what features can be reconstructed and at what statistical significance.Comment: 43 pages Revtex, 23 figure