Neutron Acceleration in Uniform Electromagnetic Fields

The question as to whether neutron acceleration can occur in uniform electromagnetic fields is examined. Although such an effect has been predicted using the canonical equations of motion some doubt has been raised recently as to whether it is in principle observable for a spin 1/2 particle. To resolve this issue a gedanken experiment is proposed and analyzed using a wave packet construction for the neutron beam. By allowing arbitrary orientation for the neutron spin as well as for the electric and magnetic fields a non vanishing acceleration of the center of the neutron wave packet is found which confirms the predictions of the canonical formalism.Comment: 11 page

Gravitational Phase Operator and Cosmic Strings

A quantum equivalence principle is formulated by means of a gravitational phase operator which is an element of the Poincare group. This is applied to the spinning cosmic string which suggests that it may (but not necessarily) contain gravitational torsion. A new exact solution of the Einstein- Cartan-Sciama-Kibble equations for the gravitational field with torsion is obtained everywhere for a cosmic string with uniform energy density, spin density and flux. A novel effect due to the quantized gravitational field of the cosmic string on the wave function of a particle outside the string is used to argue that spacetime points are not meaningful in quantum gravity.Comment: 22 pages, to be published Phys. Rev. D. Some minor changes have been made and a reference has been added to the paper of D.V. Gal'tsov and P.S. Letelier, Phys. Rev. D 47 (1993) 4273, which first contained the metric (2.2) external to the cosmic string. The present paper extends this solution to a regular solution inside the string as wel

Quantum Interference to Measure Spacetime Curvature: A Proposed Experiment at the Intersection of Quantum Mechanics and General Relativity

An experiment in Low Earth Orbit (LEO) is proposed to measure components of the Riemann curvature tensor using atom interferometry. We show that the difference in the quantum phase $\Delta\phi$ of an atom that can travel along two intersecting geodesics is given by $mR_{0i0j}/\hbar$ times the spacetime volume contained within the geodesics. Our expression for $\Delta\phi$ also holds for gravitational waves in the long wavelength limit.Comment: 7 pages LaTeXed with RevTeX 4.0, 2 figures. Submitted to the 2003 Gravity Research Foundation Essay Contes

Geometric Phase and Modulo Relations for Probability Amplitudes as Functions on Complex Parameter Spaces

We investigate general differential relations connecting the respective behavior s of the phase and modulo of probability amplitudes of the form \amp{\psi_f}{\psi}, where $\ket{\psi_f}$ is a fixed state in Hilbert space and $\ket{\psi}$ is a section of a holomorphic line bundle over some complex parameter space. Amplitude functions on such bundles, while not strictly holomorphic, nevertheless satisfy generalized Cauchy-Riemann conditions involving the U(1) Berry-Simon connection on the parameter space. These conditions entail invertible relations between the gradients of the phase and modulo, therefore allowing for the reconstruction of the phase from the modulo (or vice-versa) and other conditions on the behavior of either polar component of the amplitude. As a special case, we consider amplitude functions valued on the space of pure states, the ray space ${\cal R} = {\mathbb C}P^n$, where transition probabilities have a geometric interpretation in terms of geodesic distances as measured with the Fubini-Study metric. In conjunction with the generalized Cauchy-Riemann conditions, this geodesic interpretation leads to additional relations, in particular a novel connection between the modulus of the amplitude and the phase gradient, somewhat reminiscent of the WKB formula. Finally, a connection with geometric phases is established.Comment: 11 pages, 1 figure, revtex

Investigation of electrochemical behavior of plasma nitrided Ti-6Al-7Nb alloy in Hanks’ Solution

Titanium alloy Ti-6Al-7Nb was plasma nitrided using inductively coupled RF Plasma with 100% Nitrogen at 750, 800 and 850°C for 4 h. Micro Raman studies show the formation of titanium nitrides. Potentiodynamic polarization studies in Hanks’ solution show the corrosion resistance of the untreated samples to be better than the treated samples. Electrochemical Impedance Spectroscopy (EIS) studies show higher charge transfer resistance and lower double layer capacitance for the substrate compared to the nitrided samples. FESEM images of samples immersed in SBF show that growth of apatite is more and the size of deposits are larger on nitrided samples as compared to that on the untreated substrate. Nitrided samples immersed in Hanks’ solution for 7 days show higher amount of calcium, phosphorous and oxygen than the substrate

Fatty acid signatures of the Indian mackerel Rastrelliger kanagurta (Cuvier)from the Arabian Sea along the Indian coast

The fatty acid profile of the Indian mackerel Rastrelliger kanagurta from the Arabian Sea was studied in relation to its maturation and spawning cycle. Among fatty acids, polyunsaturated fatty acids (PUFA) component was the highest (46.9%) followed by saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) at 41.8% and 11% respectively. No differences were observed between the period of low spawning activity in January and peak spawning activity in May. However significant (p<0.05) differences were observed with regard to sex where females had higher levels of SFA and MUFA while males had higher levels of PUFA. With regard to maturity stages, only females showed significant differences (p<0.05) in MUFA content with higher level in mature stages compared to immature stages. Docosahexaenoic acid (DHA) was the single largest component of PUFA. The absence of marked temperature differences in the Arabian Sea probably precludes seasonal effects on the levels of SFA, MUFA and PUFA in the Indian mackerel while variations of individual FA within these groups indicate lipid dynamics in relation to reproduction and feeding

Functional outcome of unstable intertrochanteric fractures managed with proximal femoral nail: a prospective analysis

Background: Hip fractures are a growing concern for the orthopedic surgeons all over the world because the incidence of hip fractures is increasing dramatically and these fractures impose a significant challenge in their efficient management. The aim of the study was to prospectively analyze the functional outcome of unstable intertrochanteric fractures managed with ‘proximal femoral nail’.Methods: In our institution, we have selected 24 cases of unstable intertrochanteric fractures for this prospective study. All cases enrolled were managed with the proximal femoral nail. These cases were studied from the mechanism of injury, classification, and treatment with the proximal femoral nail and their surgical and functional outcome with or without residual comp.Results: Patients were followed up for an average period of 8.58 months. The mean Harris hip score was 88.75 at 6th month. The score was excellent in 12 patients, good in 10 patients, fair in 1 patient and poor in 1 patient. In our study of 24 patients with unstable intertrochanteric fracture, the average age incidence was 54.64 years. In the present study male: female was 5:3.Conclusions: In unstable proximal femur fractures, PFN is a significant advancement in the treatment of unstable trochanteric fractures which has the unique advantages of closed reduction, preservation of fracture hematoma, less tissue damage, early rehabilitation and early return to work

Macrobenthos of intertidal zone of Versova along the coast of Mumbai

To assess the biodiversity of macro benthos in the changing environment along the coast of Mumbai, the intertidal zone of Versova was identified. The water quality in this intertidal region was poor with low pH, salinity and dissolved oxygen, and high nitrite, nitrate, phosphate and ammonia. The substratum was sandy with 1.29% organic matter in it. Mean faunal density of 2257 no./m² was recorded during the study which was mainly contributed by polychaetes (83.5%) followed by amphipods (14.5%), while other groups represented were isopods, crabs, hermit crabs, unidentified decapods, pelecypods and gastropods. Average biomass of 34.83 g/m² (93.7%) was contributed by polychaetes. Shannon and Wiener Index (0.4107) indicated heavy pollution in the intertidal area of Versova

Global Topology and Local Violation of Discrete Symmetries

Cosmological models that are locally consistent with general relativity and the standard model in which an object transported around the universe undergoes P, C and CP transformations, are constructed. This leads to generalization of the gauge fields that describe electro-weak and strong interactions by enlarging the gauge groups to include anti-unitary transformations. Gedanken experiments show that if all interactions obey Einstein causality then P, C and CP cannot be violated in these models. But another model, which would violate charge superselection rule even for an isolated system, is allowed. It is suggested that the fundamental physical laws must have these discrete symmetries which are broken spontaneously, or they must be non causal.Comment: 12 pages, 1 figure, latex, Revtex. Charge conjugation which is physically implemented in a cosmology with the appropriate topology is described in more detail. Some minor errors are corrected. Shortened to meet the page limit of Physical Review Letters to which this paper was submitte

Fabrication of Superhydrophobic Zinc Stearate Hierarchical Surfaces from Different Precursors

The fabrication of zinc stearate superhydrophobic hierarchical surfaces from two precursors by a simple wet chemical route and its wettability is reported. The zinc stearate coatings were prepared from a single pot using ethanolic solutions of zinc acetate/zinc nitrate and stearic acid. The coatings were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, water contact angle, and sliding angle measurements. The coatings obtained from zinc acetate precursor showed superhydrophobicity (WCA >150°) even at lower precursor concentrations. The morphology of the coatings varied with the nature as well as the concentration of the precursors