Development of a meteoroid penetration distributed transducer Third quarterly report

Impact calibration tests in development of meteoroid penetration distributed transduce

Orbital and meteorological factors pertinent to satellite transmissions of facsimile weather charts Final report

Automatic picture transmission system on Nimbus and earth synchronous satellites for transmission of weather chart

Forgiveness Motives Among Evangelical Christians: Implications for Christian Marriage and Family Therapists

Therapists and researchers interested in forgiveness can learn from those who have experienced interpersonal wounds and have chosen to forgive. We interviewed 20 evangelical Christian forgivers, asking about motives for forgiveness. Transcripts were analyzed using qualitative methods. Five categories of motivation are presented: comfort, duty, relational, humility/empathy, and Christian beliefs. Respondents described multiple motives for forgiveness, often combining a desire for comfort or a sense of duty with their Christian beliefs. Four implications for Christian marriage and family therapists are discussed: Expect diversity, avoid moralistic views of motives, remember religious resources in the forgiveness process, and expect benefits, but not immediately

Enhanced graphene nonlinear response through geometrical plasmon focusing

We propose a simple approach to couple light into graphene plasmons and focus these excitations at focal spots of a size determined by the plasmon wavelength, thus producing high optical field enhancement that boosts the nonlinear response of the material. More precisely, we consider a graphene structure in which incident light is coupled to its plasmons at the carbon edges and subsequently focused on a spot of size comparable to the plasmon wavelength. We observe large confinement of graphene plasmons, materializing in small, intense focal spots, in which the extraordinary nonlinear response of this material leads to relatively intense harmonic generation. This result shows the potential of plasmon focusing in suitably edged graphene structures to produce large field confinement and nonlinear response without involving elaborated nanostructuring.Peer ReviewedPostprint (published version

Low-temperature nucleation in a kinetic Ising model with soft stochastic dynamics

We study low-temperature nucleation in kinetic Ising models by analytical and simulational methods, confirming the general result for the average metastable lifetime, = A*exp(beta*Gamma) (beta = 1/kT) [E. Jordao Neves and R.H. Schonmann, Commun. Math. Phys. 137, 209 (1991)]. Contrary to common belief, we find that both A and Gamma depend significantly on the stochastic dynamic. In particular, for a ``soft'' dynamic, in which the effects of the interactions and the applied field factorize in the transition rates, Gamma does NOT simply equal the energy barrier against nucleation, as it does for the standard Glauber dynamic, which does not have this factorization property.Comment: 4 pages RevTex4, 2 figures. Phys. Rev. Lett., in pres

Calculation of the Raman G peak intensity in monolayer graphene: role of Ward identities

The absolute integrated intensity of the single-phonon Raman peak at 1580 cm^{-1} is calculated for a clean graphene monolayer. The resulting intensity is determined by the trigonal warping of the electronic bands and the anisotropy of the electron-phonon coupling, and is proportional to the second power of the excitation frequency. The main contribution to the process comes from the intermediate electron-hole states with typical energies of the order of the excitation frequency, contrary to what has been reported earlier. This occurs because of strong cancellations between different terms of the perturbation theory, analogous to Ward identities in quantum electrodynamics

A projection method for statics and dynamics of lattice spin systems

A method based on Monte Carlo sampling of the probability flows projected onto the subspace of one or more slow variables is proposed for investigation of dynamic and static properties of lattice spin systems. We illustrate the method by applying it, with projection onto the order-parameter subspace, to the three-dimensional 3-state Potts model in equilibrium and to metastable decay in a three-dimensional 3-state kinetic Potts model.Comment: 4 pages, 3 figures, RevTex, final version to appear in Phys. Rev. Let

Kinetic Ising System in an Oscillating External Field: Stochastic Resonance and Residence-Time Distributions

Experimental, analytical, and numerical results suggest that the mechanism by which a uniaxial single-domain ferromagnet switches after sudden field reversal depends on the field magnitude and the system size. Here we report new results on how these distinct decay mechanisms influence hysteresis in a two-dimensional nearest-neighbor kinetic Ising model. We present theoretical predictions supported by numerical simulations for the frequency dependence of the probability distributions for the hysteresis-loop area and the period-averaged magnetization, and for the residence-time distributions. The latter suggest evidence of stochastic resonance for small systems in moderately weak oscillating fields.Comment: Includes updated results for Fig.2 and minor text revisions to the abstract and text for clarit