Charged particles in a rotating magnetic field

We study the valence electron of an alkaline atom or a general charged particle with arbitrary spin and with magnetic moment moving in a rotating magnetic field. By using a time-dependent unitary transformation, the Schr\"odinger equation with the time-dependent Hamiltonian can be reduced to a Schr\"odinger-like equation with a time-independent effective Hamiltonian. Eigenstates of the effective Hamiltonian correspond to cyclic solutions of the original Schr\"odinger equation. The nonadiabatic geometric phase of a cyclic solution can be expressed in terms of the expectation value of the component of the total angular momentum along the rotating axis, regardless of whether the solution is explicitly available. For the alkaline atomic electron and a strong magnetic field, the eigenvalue problem of the effective Hamiltonian is completely solved, and the geometric phase turns out to be a linear combination of two solid angles. For a weak magnetic field, the same problem is solved partly. For a general charged particle, the problem is solved approximately in a slowly rotating magnetic field, and the geometric phases are also calculated.Comment: REVTeX, 13 pages, no figure. There are two minor errors in the published version due to incorrect editing by the publisher. The "spin-1" in Sec. I and the "spin 1" in Sec. II below Eq. (2c) should both be changed to "spin" or "spin angular momentum". The preferred E-mail for correspondence is [email protected] or [email protected]

Estimation of total phenolic, total flavonoid content and evaluation of anti-inflammatory and antioxidant activity of Ixora coccinea Linn. stems

Ixora coccinea Linn. (Rubiaceae) has mentioned in Ayurveda as Paranti and traditionally stems used in inflammatory diseases like sprains, eczema, contusions and boils.  Present study deals with evaluation of anti-inflammatory and antioxidant activity of extracts of I.coccinea stem. Anti-inflammatory activity was studied in vivo by carrageenan-induced paw edema in rat and in vitro by human red blood cell membrane stabilization method. Total tannin and flavonoid content of extracts was determined by using the Folin- Ciocalteu method and aluminum chloride method, respectively. Antioxidant activity was evaluated by in vitro assay involving nitric oxide scavenging, hydrogen peroxide scavenging, 2,2-  diphenylpicrylhydrazyl (DPPH) radical scavenging, and ion chelating activity. Chloroform extract showed significant reduction in carrageenan induced rat paw edema (p<0.05) and protection of HRBC in hypotonic solution. Methanol extract contain more total tannin and flavonoid content as compared with petroleum ether and chloroform extract. All extracts showed concentration dependant free radical scavenging activity. Methanol extract and chloroform extract have shown better antioxidant activity and due to this antioxidant nature might be responsible for its anti-inflammatory activity. These activity supports to use of I.coccinea extract in traditional used in treatment of various inflammatory disaeses

Performance Analysis of MUSIC and Smooth MUSIC Algorithm for DOA Estimation

Smart Antenna Systems is one amongst speedily developing areas of wireless communication. With effective direction of arrival (DOA) and Beam forming techniques Smart Antenna Systems persuade is most effective in terms of quality of signals in wireless communication. This paper analyzed and compares the performance of MUSIC and Smooth MUSIC DOA estimation algorithm on the uniform linear array (ULA) which are used in design of smart antenna system. MUSC algorithm is high resolution subspace based method which is used for DOA estimation of uncorrelated signals while smoothing of MUSIC is introduced for DOA estimation of completely correlated signal. The angular resolution of DOA estimation techniques improves as number of elements in array, snapshots and values of SNR increases. DOI: 10.17762/ijritcc2321-8169.15071

Observation of off-diagonal geometric phase in polarized neutron interferometer experiments

Off-diagonal geometric phases acquired in the evolution of a spin-1/2 system have been investigated by means of a polarized neutron interferometer. Final counts with and without polarization analysis enable us to observe simultaneously the off-diagonal and diagonal geometric phases in two detectors. We have quantitatively measured the off-diagonal geometric phase for noncyclic evolutions, confirming the theoretical predictions. We discuss the significance of our experiment in terms of geometric phases (both diagonal and off-diagonal) and in terms of the quantum erasing phenomenon.Comment: pdf, 22 pages + 8 figures (included in the pdf). In print on Phys. Rev.

Final Report of the Commission to Address the Unfunded Liability of the MSRS and the Equity of Retirement Benefits for State Employees and Teachers

The possibility of cryopreservingBalanus amphitrite(Cirripedia; thoracica) nauplii is explored. The effects on the postthaw survival of a range of cryobiological variables are reported; three different cryoprotectants (ethylene glycol, EG; dimethyl sulfoxide, Me<SUB>2</SUB>SO; and glycerol, GL), the influence of the final temperature (−20, −30, −40, and −50°C), and the effect of transferring to liquid nitrogen (−196°C) were studied. The larvae showed increasing susceptibility to cryoprotectant concentration. Equilibration of larvae for 15 min at 5°C with each of the cryoprotectants revealed that GL was the least toxic. EG at 3 to 4Mdid not cause marked damage as the equilibration period was extended up to 2 h. This was not true with Me<SUB>2</SUB>SO and GL. The postthaw survival rate decreased as the final temperature was reduced, and none of the larvae revived after thawing from −50°C. The postthaw survival with 2 mol/liter EG as the cryoprotectant ranged from 86% after cooling to −20°C to 56% after cooling to −40°C. The larvae that were transferred to liquid nitrogen from different temperatures revealed that the greatest survival (36%) was achieved when the larvae were transferred from −40 to −196°C. When the larvae were reared after cooling to −40°C and then transferring to liquid nitrogen, the rate of subsequent metamorphosis was 30% in the case of EG at 3M. Me<SUB>2</SUB>SO and GL gave results that were inferior in comparison to those obtained with EG

Geometric Phases and Multiple Degeneracies in Harmonic Resonators

In a recent experiment Lauber et al. have deformed cyclically a microwave resonator and have measured the adiabatic normal-mode wavefunctions for each shape along the path of deformation. The nontrivial observed cyclic phases around a 3-fold degeneracy were accounted for by Manolopoulos and Child within an approximate theory. However, open-path geometrical phases disagree with experiment. By solving exactly the problem, we find unsuspected extra degeneracies around the multiple one that account for the measured phase changes throughout the path. It turns out that proliferation of additional degeneracies around a multiple one is a common feature of quantum mechanics.Comment: 4 pages, 4 figures. Accepted in Phys. Rev. Let

Geometric phases for neutral and charged particles in a time-dependent magnetic field

It is well known that any cyclic solution of a spin 1/2 neutral particle moving in an arbitrary magnetic field has a nonadiabatic geometric phase proportional to the solid angle subtended by the trace of the spin. For neutral particles with higher spin, this is true for cyclic solutions with special initial conditions. For more general cyclic solutions, however, this does not hold. As an example, we consider the most general solutions of such particles moving in a rotating magnetic field. If the parameters of the system are appropriately chosen, all solutions are cyclic. The nonadiabatic geometric phase and the solid angle are both calculated explicitly. It turns out that the nonadiabatic geometric phase contains an extra term in addition to the one proportional to the solid angle. The extra term vanishes automatically for spin 1/2. For higher spin, however, it depends on the initial condition. We also consider the valence electron of an alkaline atom. For cyclic solutions with special initial conditions in an arbitrary strong magnetic field, we prove that the nonadiabatic geometric phase is a linear combination of the two solid angles subtended by the traces of the orbit and spin angular momenta. For more general cyclic solutions in a strong rotating magnetic field, the nonadiabatic geometric phase also contains extra terms in addition to the linear combination.Comment: revtex, 18 pages, no figur

A használatalapú biztosítás múltja, jelene és jövője

[Cp*RuCl]₄ (1) has previously been shown to be the precatalyst of choice for stereochemically unorthodox trans-hydrometalations of internal alkynes. Experimental and computational data now prove that the alkyne primarily acts as a four-electron donor ligand to the catalytically active metal fragment [Cp*RuCl] but switches to adopt a two-electron donor character once the reagent R₃MH (M = Si, Ge, Sn) enters the ligand sphere. In the stereodetermining step the resulting loaded complex evolves via an inner-sphere mechanism into a ruthenacyclopropene which swiftly transforms into the product. In accord with the low computed barriers, spectral and preparative data show that the reaction is not only possible but sometimes even favored at low temperatures. Importantly, such trans-hydrometalations are distinguished by excellent levels of regioselectivity when unsymmetrical alkynes are used that carry an −OH or −NHR group in vicinity of the triple bond. A nascent hydrogen bridge between the protic substituent and the polarized [Ru–Cl] unit imposes directionality onto the ligand sphere of the relevant intermediates, which ultimately accounts for the selective delivery of the R₃M– group to the acetylene C-atom proximal to the steering substituent. The interligand hydrogen bonding also allows site-selectivity to be harnessed in reactions of polyunsaturated compounds, since propargylic substrates bind more tightly than ordinary alkynes; even the electronically coupled triple bonds of conjugated 1,3-diynes can be faithfully discriminated as long as one of them is propargylic. Finally, properly positioned protic sites lead to a substantially increased substrate scope in that they render even 1,3-enynes, arylalkynes, and electron-rich alkynylated heterocycles amenable to trans-hydrometalation which are otherwise catalyst poisons

Off-Diagonal Geometric Phases

We investigate the adiabatic evolution of a set of non-degenerate eigenstates of a parameterized Hamiltonian. Their relative phase change can be related to geometric measurable quantities that extend the familiar concept of Berry phase to the evolution of more than one state. We present several physical systems where these concepts can be applied, including an experiment on microwave cavities for which off-diagonal phases can be determined from published data.Comment: 5 pages 2 figures - RevTeX. Revised version including geometrical interpretatio

Polymethyl Methacrylate as a Binder for Pyrotechnic Compositions

Studies on polymethyl methacrylate (PMMA) as a binder for igniter and delay compositions are reported. Igniter compositions based on magnesium and boron as fuels and potassium nitrate as oxidiser, delay compositions comprising ferrosilicon and red lead, have been investigated. These compositions were subjected to various tests, such as linear burning rate, sensitivity, calorimetric value, compatibility, pelleting properties, spark sensitivity, ignition temperatures and performance characteristics. The results indicate that the igniter compositions Mg:KNO/sub 3/:PMMA (42:50:8) and B:KNO/sub 3/:PMMA (30:70:10) as well as the delay composition comprising FeSi:Pb/sub 3/O/sub 4:PMMA (25:75:1) have improved properties and therefore could find practical applications