Quantum mechanics and geodesic deviation in the brane world

We investigate the induced geodesic deviation equations in the brane world models, in which all the matter forces except gravity are confined on the 3-brane. Also, the Newtonian limit of induced geodesic deviation equation is studied. We show that in the first Randall-Sundrum model the Bohr-Sommerfeld quantization rule is as a result of consistency between the geodesic and geodesic deviation equations. This indicates that the path of test particle is made up of integral multiples of a fundamental Compton-type unit of length $h/mc$.Comment: 5 pages, no figure

Magneto-hydrodynamics of multi-phase flows in heterogeneous systems with large property gradients

From Springer Nature via Jisc Publications RouterHistory: received 2021-02-02, accepted 2021-08-13, registration 2021-08-23, pub-electronic 2021-09-23, online 2021-09-23, collection 2021-12Publication status: PublishedFunder: Engineering and Physical Sciences Research Council; doi: http://dx.doi.org/10.13039/501100000266; Grant(s): EP/P005284/1Abstract: The complex interplay between thermal, hydrodynamic, and electromagnetic, forces governs the evolution of multi-phase systems in high technology applications, such as advanced manufacturing and fusion power plant operation. In this work, a new formulation of the time dependent magnetic induction equation is fully coupled to a set of conservation laws for multi-phase fluid flow, energy transport and chemical species transport that describes melting and solidification state transitions. A finite-volume discretisation of the resulting system of equations is performed, where a novel projection method is formulated to ensure that the magnetic field remains divergence free. The proposed framework is validated by accurately replicating a Hartmann flow profile. Further validation is performed through correctly predicting the experimentally observed trajectory of Argon bubbles rising in a liquid metal under varying applied magnetic fields. Finally, the applicability of the framework to technologically relevant processes is illustrated through the simulation of an electrical arc welding process between dissimilar metals. The proposed framework addresses an urgent need for numerical methods to understand the evolution of multi-phase systems with large electromagnetic property contrast

Muon Simulations for Super-Kamiokande, KamLAND and CHOOZ

Muon backgrounds at Super-Kamiokande, KamLAND and CHOOZ are calculated using MUSIC. A modified version of the Gaisser sea level muon distribution and a well-tested Monte Carlo integration method are introduced. Average muon energy, flux and rate are tabulated. Plots of average energy and angular distributions are given. Implications on muon tracker design for future experiments are discussed.Comment: Revtex4 33 pages, 16 figures and 4 table

Detection of somatic changes in human cancer DNA by DNA fingerprint analysis.

Minisatellite DNA probes which can detect a large number of autosomal loci dispersed throughout the human genome were used to examine the constitutional and tumour DNA of 35 patients with a variety of cancers of which eight were of gastrointestinal origin. Somatic changes were seen in the tumour DNA in ten of the 35 cases. The changes included alterations in the relative intensities of hybridising DNA fragments, and, in three cases of cancers of gastrointestinal origin, the appearance of novel minisatellite fragments not seen in the corresponding constitutional DNA. The results of this preliminary study suggests that DNA fingerprint analysis provides a useful technique for identifying somatic changes in cancers

Encapsulated sink-side thermal energy storage for pulsed space power systems

In sprint mode space applications, which require high power for relatively short durations, energy storage devices may be employed to reduce the size and mass of the thermal management system. This is accomplished by placing the reject heat in the thermal store during the sprint mode. During the remaining nonoperational portion of the orbit the stored heat is dissipated to space. The heat rejection rate is thus reduced, and this results in a smaller radiator being required. Lithium hydride (LiH) has been identfied as the best candidate for use in power system sink-side thermal energy storage applications due to its superior heat storage properties and suitable melt temperature (T/sub m/ = 962K). To maximize storage density, both sensible and latent modes of heat storage are used. This paper focuses on the use of encapsulated lithium hydride shapes in a packed bed storage unit with lithium or NaK as the heat transport fluid. Analytical and experimental development work associated with the concept is described. Since the program is in its early stages, emphasis thus far has been on feasibility issues associated with encapsulating lithium hydride spheres. These issues include shell stress induced by phase-change during heating, hydrogen diffusion through the encapsulating shell, heat transfer limitations due to poor conductivity of the salt, void behavior, and material constraints. The impact of these issues on the design of encapsulated lithium hydride spheres has been evaluated, and design alternatives have been identified for circumventing key problem areas

Crystal electric field excitations in the quasicrystal approximant TbCd6 studied by inelastic neutron scattering

We have performed inelastic neutron scattering measurements on powder samples of the quasicrystal approximant, TbCd6, grown using isotopically enriched 112Cd. Both quasielastic scattering and distinct inelastic excitations were observed below 3 meV. The intensity of the quasielastic scattering measured in the paramagnetic phase diverges as TN∼22 K is approached from above. The inelastic excitations, and their evolution with temperature, are well characterized by the leading term, B02O02, of the crystal electric field (CEF) level scheme for local pentagonal symmetry for the rare-earth ions [S. Jazbec et al., Phys. Rev. B 93, 054208 (2016)] indicating that the Tb moment is directed primarily along the unique local pseudofivefold axis of the Tsai-type clusters. We also find good agreement between the inverse susceptibility determined from magnetization measurements using a magnetically diluted Tb0.05Y0.95Cd6 sample and that calculated using the CEF level scheme determined from the neutron measurements

Low-frequency cortical activity is a neuromodulatory target that tracks recovery after stroke.

Recent work has highlighted the importance of transient low-frequency oscillatory (LFO; <4 Hz) activity in the healthy primary motor cortex during skilled upper-limb tasks. These brief bouts of oscillatory activity may establish the timing or sequencing of motor actions. Here, we show that LFOs track motor recovery post-stroke and can be a physiological target for neuromodulation. In rodents, we found that reach-related LFOs, as measured in both the local field potential and the related spiking activity, were diminished after stroke and that spontaneous recovery was closely correlated with their restoration in the perilesional cortex. Sensorimotor LFOs were also diminished in a human subject with chronic disability after stroke in contrast to two non-stroke subjects who demonstrated robust LFOs. Therapeutic delivery of electrical stimulation time-locked to the expected onset of LFOs was found to significantly improve skilled reaching in stroke animals. Together, our results suggest that restoration or modulation of cortical oscillatory dynamics is important for the recovery of upper-limb function and that they may serve as a novel target for clinical neuromodulation