Simulation of charged particle trajectories in the neutron decay correlation experiment abBA

The proposed neutron decay correlation experiment, abBA, will directly detect the direction of emission of decay protons and electrons as well as providing spectroscopic information for both particles. In order to provide this information, the abBA experiment incorporates spatially varying electric and magnetic fields. We report on detailed simulations of the decay particle trajectories in order to assess the impact of various systematic effects on the experimental observables. These include among others; adiabaticity of particle orbits, tracking of orbits, reversal of low energy protons due to inhomogeneous electric field, and accuracy of proton time of flight measurements. Several simulation methods were used including commercial software (Simion), custom software, as well as analytical tools based on the use of adiabatic invariants. Our results indicate that the proposed field geometry of the abBA spectrometer will be substantially immune to most systematic effects and that transport calculations using adiabatic invariants agree well with solution of the full equations of motion

SYNTHESIS, IN VITRO ANTIMICROBIAL ACTIVITY OF SCHIFF'S BASE, AZETIDINONES AND THIAZOLIDINONES

Objective: The objective of the present study is to synthesize 3-Chloro-4-[3-(2,4-dichloro-5-fluoro phenyl)-1H-pyrazol-4-yl]-1-(substituted) azetidin-2-one [4a-n] and 2-[3-(2,4-Dichloro-5-fluoro phenyl)-1H-pyraol-4-yl]-3-(substituted phenyl)-1,3-thiazolidin-4-one [5a-n]. The structure of all synthesized compounds were characterized by IR, 1H NMR, 13C NMR and mass spectral studies. Methods: The titled compounds 3-Chloro-4-[3-(2,4-dichloro-5-fluoro phenyl)-1H-pyrazol-4-yl]-1-(substituted) azetidin-2-one [4a-n] and 2-[3-(2,4-Dichloro-5-fluoro phenyl)-1H-pyraol-4-yl]-3-(substituted phenyl)-1,3-thiazolidin-4-one [5a-n] were synthesized by the reaction of N-{[3-(2,4-dichloro-5-fluoro phenyl)-1H-pyraol-4-yl] methylene } substituted anilin [3a-n] with chloro acetyl chloride and thioglycolic acid respectively. Compounds N-{[3-(2,4-dichloro-5-fluoro phenyl)-1H-pyraol-4-yl] methylene} substituted aniline [3a-n] were synthesized by the reaction of 3-(2,4-dichloro-5-fluoro phenyl)-1H-pyrazol-4-carbaldehyde [2] with primary aromatic amine in alcohol. All compounds were evaluated for their antimicrobial activity.Results: Compounds 3a,3b,3d,3j,3l,4d,4e,4j,4l,4m,5e,5g,5h,5n exhibited excellent to good antibacterial activity as compared to reference drugs.Conclusion: In summary, N-{[3-(2,4-dichloro-5-fluoro phenyl)-1H-pyraol-4-yl] methylene } substituted anilin [3a-n], 3-Chloro-4-[3-(2,4-dichloro-5-fluoro phenyl)-1H-pyrazol-4-yl]-1-(substituted) azetidin-2-one [4a-n] and 2-[3-(2,4-Dichloro-5-fluoro phenyl)-1H-pyraol-4-yl]-3-(substituted phenyl)-1,3-thiazolidin-4-one [5a-n] derivatives have been synthesized and characterized. In vitro antimicrobial testing of the compounds was carried out by microdilution Method. Amongst the synthesised compounds, many of them had proven their antimicrobial potency which varies from good to excellent

Crystal Structures of Influenza A Virus Matrix Protein M1: Variations on a Theme

Matrix protein 1 (M1) of the influenza A virus plays multiple roles in virion assembly and infection. Interest in the pH dependence of M1\u27s multiple functions led us to study the effect of subtle pH changes on M1 structure, resulting in the elucidation of a unique low-pH crystal structure of the N1-165-domain of A/WSN/33 (H1N1) M1 that has never been reported. Although the 2.2 Å crystal structure of M1 N-terminus shows a dimer with the two monomers interacting in a face-to-face fashion at low pH as observed earlier, a 44° rotation of the second monomer has led to a significantly different dimer interface that possibly affects dimer stability. More importantly, while one of the monomers is fully defined, the N-terminal half of the second monomer shows considerable disorder that appears inherent in the protein and is potentially physiologically relevant. Such disorder has not been observed in any other previously reported structure at either low or high pH conditions, despite similar crystallization pH conditions. By comparing our novel N1-165-domain structure with other low-pH or neutral-pH M1 structures, it appears that M1 can energetically access different monomer and dimer conformations, as well as oligomeric states, with varying degree of similarities. The study reported here provides further insights into M1 oligomerization that may be essential for viral propagation and infectivity

The Sizes of 1720 MHz OH Masers: VLBA and MERLIN Observations of the Supernova Remnants W44 and W28

We have used the NRAO Very Long Baseline Array (VLBA) to image OH(1720 MHz) masers in the supernova remnants W28 and W44 at a resolution of 40 mas. We also used MERLIN to observe the same OH(1720 MHz) masers in W44 at a resolution of 290 x 165 mas. All the masers are resolved by these VLBA and MERLIN observations. The measured sizes range from 50 to 180 mas and yield brightness temperature estimates from 0.3--20 x 10**8 K. We investigate whether these measured angular sizes are intrinsic and hence originate as a result of the physical conditions in the supernova remnant shock, or whether they are scatter broadened sizes produced by the turbulent ionized gas along the line of sight. While the current data on the temporal and angular broadening of pulsars, masers and extragalactic soures toward W44 and W28 can be understood in terms of scattering, we cannot rule out that these large sizes are intrinsic. Recent theoretical modeling by Lockett et al. suggests that the physical parameters in the shocked region are indicative of densities and OH abundances which lead to estimates of sizes as large as what we measure. If the sizes and structure are intrinsic, then the OH(1720 MHz) masrs may be more like the OH(1612 MHz) masers in circumstellar shells than OH masers associated with HII regions. At two locations in W28 we observe the classical S-shapes in the Stokes V profiles caused by Zeeman splitting and use it to infer magnetic fields of order 2 milliGauss.Comment: 24 pages, 6 figures, accepted by Ap

A Note on Heat Transfer and Film Boiling

<p>Descriptive statistics and bivariate correlations (Study 3).</p

Pairwise Balanced Designs From Cyclic PBIB Designs

A pairwise balanced designs was constructed using cyclic partially balanced incomplete block designs with either (λ1 – λ2) = 1 or (λ2 – λ1) = 1. This method of construction of Pairwise balanced designs is further generalized to construct it using cyclic partially balanced incomplete block design when |(λ1 – λ2)| = p. The methods of construction of pairwise balanced designs was supported with examples. A table consisting parameters of Cyclic PBIB designs and its corresponding constructed pairwise balanced design is also included

Persistent time intervals between features in solar flare hard X-ray emission

Several solar hard X-ray events (greater than 100 keV) were observed simultaneously with identical instruments on the Venera 11, 12, 13, 14, and Prognoz spacecraft. High time resolution (= 2 ms) data were stored in memory when a trigger occurred. The observations of modulation are presented with a period of 1.6 s for the event on December 3, 1978. Evidence is also presented for fast time fluctuations from an event on November 6, 1979, observed from Venera 12 and another on September 6, 1981, observed from the Solar Maximum Mission. Power spectrum analysis, epoch folding, and Monte Carlo simulation were used to evaluate the statistical significance of persistent time delays between features. The results are discussed in light of the MHD model proposed by Zaitsev and Stepanov