3,133 research outputs found
Multiphoton Bloch-Siegert shifts and level-splittings in spin-one systems
We consider a spin-boson model in which a spin 1 system is coupled to an
oscillator. A unitary transformation is applied which allows a separation of
terms responsible for the Bloch-Siegert shift, and terms responsible for the
level splittings at anticrossings associated with Bloch-Siegert resonances.
When the oscillator is highly excited, the system can maintain resonance for
sequential multiphoton transitions. At lower levels of excitation, resonance
cannot be maintained because energy exchange with the oscillator changes the
level shift. An estimate for the critical excitation level of the oscillator is
developed.Comment: 14 pages, 3 figure
Level Splitting in Association with the Multiphoton Bloch-Siegert Shift
We present a unitary equivalent spin-boson Hamiltonian in which terms can be
identified which contribute to the Bloch-Siegert shift, and to the level
splittings at the anticrossings associated with the Bloch-Siegert resonances.
First-order degenerate perturbation theory is used to develop approximate
results in the case of moderate coupling for the level splitting.Comment: 8 pages, 2 figure
Computing for science, engineering and society: Challenges, requirement, and strategic roadmap
Sierpienski fractal Slotted Hexagonal Microstrip Patch Antenna Using transmission feeding technique
There are various types of microstrip antenna that can be used for number of applications in wireless communication. In this paper, the design of Sierpienski fractal Slotted Hexagonal Microstrip Patch Antenna with FR4 glass epoxy substrate having dielectric constant, Er of 4.4, and thickness 1.6mm has been presented. It is instigated using stripline feeding. These antennas are compact, conformal to both the surfaces- planaramp; non-planar, simple, inexpensive, rugged, compatible with MMIC designs. Microstrip antenna is made up of a very thin metallic strip (patch) i.e, placed over a small fraction of a wavelength above a ground plane. The simulated results indicate that the antenna is suitable for RADAR (all types), GPS carriers, WLANs, Wimax, Satellite communication, navigation. The design is simulated using IE3D software and result is obtained in terms of smith chart, VSWR, return loss
Relativistic coupling between lattice vibrations and nuclear excitation
Abstract only.For many years we have been interested in understanding the origin of the coupling between the condensed matter system and nuclei in connection with the anomalies that have been observed in Fleischmann-Pons and related experiments. Over the past two years, it has become clear that collimated x-rays in the Karabut experiment can only be consistent with our coherent energy exchange theory if there exists a very strong coupling between lattice vibrations and nuclear transitions. We have examined the problem many times in previous years, usually with the conclusion that there can be no such effect in the non-relativistic problem. This is a consequence of the clean separation between the center of mass dynamics and relative dynamics which occurs in non-relativistic models
Theoretical landscape in condensed matter nuclear science consistent with phonon theory
Abstract only.Since the initial report of anomalies in PdD by Fleischmann and Pons back in 1989, a variety of anomalies have been seen in experiments of all kinds over the years. Although there is not agreement within our field as to precisely which anomalies should be accepted as real, in our view there is evidence for excess heat production in PdD with associated 4He emission; slow tritium production; light water excess heat in the NiH system; low-level neutron and charged particle emission; weak gamma emission; collimated x-ray emission; and different kinds of transmutation effects. None of these effects are predicted from conventional nuclear or solid state physics. Over the years we have pursued theories that describe coherent dynamics in nuclear states, in which coherent energy exchange with a highly-excited phonon mode occurs. More than a decade ago a toy mathematical model (the lossy spin-boson model) was found that was capable of demonstrating substantial coherent energy exchange rates under conditions where a large two level system quantum is fractionated into a very large number of oscillator quanta. Later, we proposed and studied a generalization of the model (which we called the donor and receiver model) which in our view implemented essentially all of the mechanisms that would be needed to account for excess heat in the Fleischmann-Pons experiment. More recently we have developed a new physics-based version of the model which allow us to extend the theory to describe coherent dynamics in physical systems. The simplest example of one of the new processes in the new theory is energy transfer from a highly-excited vibrational mode to couple to nuclear transitions, leading to nuclear excitation. We interpreted collimated x-ray emission in the Karabut experiment as an example of this mechanism. Gamma emission in the Gozzi experiment, and in Piantelli's experiment, in our view seems consistent with this mechanism. In our view, the panoply of anomalies in CMNS experiments which our community focuses on must involve a single underlying mechanism, which expresses itself in different ways under different conditions. If we suppose that the phonon-nuclear coupling and coherent dynamics that we have studied is this underlying mechanism, then we might take a step back and see what collection of physical effects we might expect if we take a systematic approach to the associated theory. What results from this exercise might be considered to be a theoretical landscape. In this presentation we provide an overview of this new theoretical landscape. The simplest class of mechanisms include lattice-induced nuclear excitation generally; subsequent radiative decay can lead to x-ray emission or gamma emission; and subsequent alpha-decay or other disintegration would produce transmutation (which we might consider overall to be a "cold fission" effect). In essence, we might expect to observe energy production under conditions where no hydrogen or deuterium is present (as claimed in experiments at Proton-21). Fusion reactions between two deuterons, or hydrogen and deuterium, combined with coherent energy exchange could account for excess heat, helium, and tritium production. In this case a generalized donor and receiver model seems relevant, and whether the vibrational modes are acoustic or optical impacts which receiver transitions are relevant. The model suggests that 3He should be seen in NiH experiments. A number of reaction pathways within the picture lead to low-level nuclear emission. The most problematic anomaly is transmutation with an associated mass increase (as claimed in the Iwamura experiment), which if real requires a neutron exchange effect combined with coherent energy exchange with the lattice
Born-Oppenheimer and fixed basis models for vibrations in a metal lattice and phonon fluctuations
Abstract only.Last year we presented results on a model for Karabut's collimated x-rays which seemed to give good agreement with experiment. When writing up the model for publication, we found an error, which forced us to pursue a different version of the model. The issue in the earlier model was that phonon-nuclear coupling based on the relativistic interaction by itself is insufficient to allow for coherent energy exchange between vibrations and nuclear excitation with as much up-conversion as seems to occur in the Karabut experiment. In the new model, we combine phonon-nuclear interactions with electron-phonon interactions to increase the fractionation power of the combined system
Village Baseline Study: Site Analysis Report for Rupandehi, Madhuri Village, Nepal
This is the report of the village baseline study of Madhuri Village in the CCAFS benchmark site of Rupandehi, Nepal conducted from June 5-9, 2011 to complement an earlier household baseline survey done in the same village.
Madhuri is located in the fertile area of the Indo-Gangetic Plain in Nepal yet faces challenges due to increasing populations, encroachment on forests, decreasing soil fertility, limited agriculture and animal productivity, lack of opportunities, and variable climatic conditions. Its circumstances present manageable opportunities to prevent an increase in food insecurity and further degradation natural resources. Madhuri has yet to incur any food or environmental crises
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