Synthesis of 4,4'-Dimethyl-3,3',5,5'-Tetranitroazoxybenzene by Selective Reduction of Trinitrotolune

Selective reduction of trinitrotoluene in dioxane solution by H/sub 2/S/NH/sub 3/ yields a mixture containing 4-amino-2,6-dinitrotoluene, 4-hydroxylamino-2,6-dinitrotoluene and 4,4'-dimethyl- 3,3',5,5'-tetranitroazoxybenzene. Treatment of crude mixture with KI/HCl converts 4-hydroxylamino-2,6-dinitrotoluene into 4-amino-2,6-dinitrotoluene as well as increases the percentage of 4,4'-dimethyl-3,3,5,5'-tetranitroazoxybenzene. The resulting compound 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was isolated and characterised by IR, NMR and elemental analysis. Its thermal decomposition as well as explosive properties have been studied. The data indicate that TATB is stable up to 294 °c and is also insensitive to impact and friction

Phase space formalisms of quantum mechanics with singular kernel

The equivalence of the Rivier-Margenau-Hill and Born-Jordan-Shankara phase space formalisms to the conventional operator approach of quantum mechanics is demonstrated. It is shown that in spite of the presence of singular kernels the mappings relating phase space functions and operators back and forth are possible.Comment: 15 pages, no figures, LATE

Long-term follow-up of intratympanic methylprednisolone versus gentamicin in patients with unilateral Menière’s disease

Objectives: To determine whether long term (>48 months) symptomatic vertigo control is sustained in patients with Menie`re’s disease from a previous comparative trial of intratympanic methylprednisolone versus gentamicin, and if the two treatments remain nonsignificantly different at longterm follow-up. Study Design: Mail survey recording vertigo frequency in the previous one and six months, further intratympanic treatment received, and validated symptom questionnaires. Setting: Outpatient hospital clinic setting. Patients: Adult patients with definite unilateral refractory Menie`re’s disease, who previously received in tratympanic treatment in a comparative trial. Intervention: A survey of trial participants who received intratympanic gentamicin (40 mg/mL) or methylprednisolone (62.5 mg/mL). Outcome measures: Primary: number of vertigo attacks in the 6 months prior to receiving this survey compared with the 6 months before the first trial injection. Secondary: : Number of vertigo attacks over the previous 1 month; validated symptom questionnaire scores of tinnitus, dizziness, vertigo, aural fullness, and functional disability. Results: Average follow-up was 70.8 months (standard deviation 17.0) from the first treatment injection. Vertigo attacks in the 6 months prior to receiving the current survey reduced by 95% compared to baseline in both drug groups (intention-to-treat analysis, both p<0.001). No significant difference between drugs was found for the primary and secondary outcomes. Eight participants (methylprednisolone ¼ 5 and gentamicin ¼ 3) required further injections for relapse after completing the original trial. Conclusion: Intratympanic methylprednisolone treatment provides effective long-lasting relief of vertigo, without the known inner-ear toxicity associated with gentamicin. There are no significant differences between the two treatments at long term follow-up

Intratympanic methylprednisolone versus gentamicin in patients with unilateral Ménière's disease: a randomised, double-blind, comparative effectiveness trial

Background Ménière’s disease is characterised by severe vertigo attacks and hearing loss. Intratympanic gentamicin,the standard treatment for refractory Ménière’s disease, reduces vertigo, but damages vestibular function and can worsen hearing. We aimed to assess whether intratympanic administration of the corticosteroid methylprednisolone reduces vertigo compared with gentamicin. Methods In this double-blind comparative eff ectiveness trial, patients aged 18–70 years with refractory unilateral Ménière’s disease were enrolled at Charing Cross Hospital (London, UK) and Leicester Royal Infirmary (Leicester, UK). Patients were randomly assigned (1:1) by a block design to two intratympanic methylprednisolone(62·5 mg/mL) or gentamicin (40 mg/mL) injections given 2 weeks apart, and were followed up for 2 years. All investigators and patients were masked to treatment allocation. The primary outcome was vertigo frequency over the final 6 months (18–24 months after injection) compared with the 6 months before the first injection. Analyses were done in the intention-to-treat population, and then per protocol. This trial is registered with ClinicalTrials.gov, number NCT00802529. Findings Between June 19, 2009, and April 15, 2013, 256 patients with Ménière’s disease were screened, 60 of whom were enrolled and randomly assigned: 30 to gentamicin and 30 to methylprednisolone. In the intention-to-treat analysis (ie, all 60 patients), the mean number of vertigo attacks in the fi nal 6 months compared with the 6 months before the fi rst injection (primary outcome) decreased from 19·9 (SD 16·7) to 2·5 (5·8) in the gentamicin group (87% reduction) and from 16·4 (12·5) to 1·6 (3·4) in the methylprednisolone group (90% reduction; mean diff erence –0·9,95% CI –3·4 to 1·6). Patients whose vertigo did not improve after injection (ie, non-responders) after being assessed by an unmasked clinician were eligible for additional injections given by a masked clinician (eight patients in the gentamicin group vs 15 in the methylprednisolone group). Two non-responders switched from methylprednisolone to gentamicin. Both drugs were well tolerated with no safety concerns. Six patients reported one adverse event each: three in the gentamicin group and three in the methylprednisolone group. The most common adverse event was minor ear infections, which was experienced by one patient in the gentamicin group and two in the methylprednisolone group. Interpretation Methylprednisolone injections are a non-ablative, effective treatment for refractory Ménière’s disease. The choice between methylprednisolone and gentamicin should be made based on clinical knowledge and patient circumstances

BPS Operators in N=4 SYM: Calogero Models and 2D Fermions

A connection between the gauge fixed dynamics of protected operators in superconformal Yang-Mills theory in four dimensions and Calogero systems is established. This connection generalizes the free Fermion description of the chiral primary operators of the gauge theory formed out of a single complex scalar to more general operators. In particular, a detailed analysis of protected operators charged under an su(1|1)contained in psu(2,2|4) is carried out and a class of operators is identified, whose dynamics is described by the rational super-Calogero model. These results are generalized to arbitrary BPS operators charged under an su(2|3) of the superconformal algebra. Analysis of the non-local symmetries of the super-Calogero model is also carried out, and it is shown that symmetry for a large class of protected operators is a contraction of the corresponding Yangian algebra to a loop algebra.Comment: 29 pages, 3 figure

Coupled Dipole Method Determination of the Electromagnetic Force on a Particle over a Flat Dielectric Substrate

We present a theory to compute the force due to light upon a particle on a dielectric plane by the Coupled Dipole Method (CDM). We show that, with this procedure, two equivalent ways of analysis are possible, both based on Maxwell's stress tensor. The interest in using this method is that the nature and size or shape of the object, can be arbitrary. Even more, the presence of a substrate can be incorporated. To validate our theory, we present an analytical expression of the force due to the light acting on a particle either in presence, or not, of a surface. The plane wave illuminating the sphere can be either propagating or evanescent. Both two and three dimensional calculations are studied.Comment: 10 pages, 8 figures and 3 table

Effective nonlinear optical properties of composite media of graded spherical particles

We have developed a nonlinear differential effective dipole approximation (NDEDA), in an attempt to investigate the effective linear and third-order nonlinear susceptibility of composite media in which graded spherical inclusions with weak nonlinearity are randomly embedded in a linear host medium. Alternatively, based on a first-principles approach, we derived exactly the linear local field inside the graded particles having power-law dielectric gradation profiles. As a result, we obtain also the effective linear dielectric constant and third-order nonlinear susceptibility. Excellent agreement between the two methods is numerically demonstrated. As an application, we apply the NDEDA to investigate the surface plasma resonant effect on the optical absorption, optical nonlinearity enhancement, and figure of merit of metal-dielectric composites. It is found that the presence of gradation in metal particles yields a broad resonant band in the optical region, and further enhances the figure of merit.Comment: 20 pages, 5 figure

Experimental Investigation on the Deformation Response of Hybrid 3D Woven Composites

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97059/1/AIAA2012-1572.pd

Decoherence of Histories and Hydrodynamic Equations for a Linear Oscillator Chain

We investigate the decoherence of histories of local densities for linear oscillators models. It is shown that histories of local number, momentum and energy density are approximately decoherent, when coarse-grained over sufficiently large volumes. Decoherence arises directly from the proximity of these variables to exactly conserved quantities (which are exactly decoherent), and not from environmentally-induced decoherence. We discuss the approach to local equilibrium and the subsequent emergence of hydrodynamic equations for the local densities.Comment: 37 pages, RevTe

Coherent states for exactly solvable potentials

A general algebraic procedure for constructing coherent states of a wide class of exactly solvable potentials e.g., Morse and P{\"o}schl-Teller, is given. The method, {\it a priori}, is potential independent and connects with earlier developed ones, including the oscillator based approaches for coherent states and their generalizations. This approach can be straightforwardly extended to construct more general coherent states for the quantum mechanical potential problems, like the nonlinear coherent states for the oscillators. The time evolution properties of some of these coherent states, show revival and fractional revival, as manifested in the autocorrelation functions, as well as, in the quantum carpet structures.Comment: 11 pages, 4 eps figures, uses graphicx packag