2,367 research outputs found

    Energy Eigenvalues For Supersymmetric Potentials via Quantum Hamilton-Jacobi Formalism

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    Using quantum Hamilton-Jacobi formalism of Leacock and Padgett, we show how to obtain the exact eigenvalues for supersymmetric (SUSY) potentials.Comment: 15 pages Latex Compile twice to get cross references correct. 2 Figures not included. Requests for figures should be sent to [email protected]

    Performance Assessment of Six Public Health Programs in Katsina State, Nigeria

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    This research aimed to evaluate the performance of six ongoing public health programs through core performance indicators in Katsina State, Nigeria. The healthcare delivery in Africa is mostly program-based. This requires that such programs need to be evaluated which may in turn help to identify any existing gaps towards the improvement of patients' access and coverage to their given service. We identified all active health facilities where our programs on malaria, Routine Immunization (RI), Family Planning (FP), Tuberculosis and Leprosy (TBL), HIV/AIDS, and Free Medicare (FMC) were being carried out. After that, a representative sample was derived to obtain data regarding five key performance indicators by using a Logistics Indicators Assessment Tool. Of 1,718 facilities, a total of 983 (57.22%) were visited, In other words, by assuming a normal distribution; each facility expectedly covers only 3,371 individuals. All programs provided different and diverse results on each indicator; however, the most obvious challenge was in the stock-out and demand vs. receipt of required medications. These are particularly for malaria, FMC, FP, and HIV. For instance, the stock-out lasted 222 days for malaria and 135 days for FP. Despite this, none of the programs had a lower than gold-standard near-term availability of required products. Program-based healthcare delivery is inadequate and ineffective unless the local system gets simultaneously developed. If required medications are not becoming available, optimal access, coverage, and benefits cannot be expected to be obtained. Clearly, Nigeria experiences a push system of meeting term supplies. Nigeria needs to strengthen its pharmaceutical system

    Quantum Hamilton-Jacobi analysis of PT symmetric Hamiltonians

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    We apply the quantum Hamilton-Jacobi formalism, naturally defined in the complex domain, to a number of complex Hamiltonians, characterized by discrete parity and time reversal (PT) symmetries and obtain their eigenvalues and eigenfunctions. Examples of both quasi-exactly and exactly solvable potentials are analyzed and the subtle differences, in the singularity structures of their quantum momentum functions, are pointed out. The role of the PT symmetry in the complex domain is also illustrated.Comment: 11 page

    Hazard Classification Testing of Primers used in Small Arms Ammunition.

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    Primer is a small initiating device used for ignition of propellant charge and subsequent ejection of projectile from a weapon. Hilherto, primers were classified under safely class. Recent accidents however, have raised doubts about their diversification. Field trials were therefore carried out to ascertain their correct behaviour under different conditions. It was observed that the nature of filling composition, its charge mass and the type of package had profound influence on the hazard classification which could change its classification from safety class to mass explosion hazard

    On Exactness Of The Supersymmetric WKB Approximation Scheme

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    Exactness of the lowest order supersymmetric WKB (SWKB) quantization condition x1x2Eω2(x)dx=nπ\int^{x_2}_{x_1} \sqrt{E-\omega^2(x)} dx = n \hbar \pi, for certain potentials, is examined, using complex integration technique. Comparison of the above scheme with a similar, but {\it exact} quantization condition, cp(x,E)dx=2πn\oint_c p(x,E) dx = 2\pi n \hbar, originating from the quantum Hamilton-Jacobi formalism reveals that, the locations and the residues of the poles that contribute to these integrals match identically, for both of these cases. As these poles completely determine the eigenvalues in these two cases, the exactness of the SWKB for these potentials is accounted for. Three non-exact cases are also analysed; the origin of this non-exactness is shown to be due the presence of additional singularities in Eω2(x)\sqrt{E-\omega^2(x)}, like branch cuts in the xx-plane.Comment: 11 pages, latex, 1 figure available on reques

    Benzene C−H Bond Activation in Carboxylic Acids Catalyzed by O-Donor Iridium(III) Complexes: An Experimental and Density Functional Study

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    The mechanism of benzene C−H bond activation by [Ir(μ-acac-O,O,C^3)(acac-O,O)(OAc)]_2 (4) and [Ir(μ-acac-O,O,C^3)(acac-O,O)(TFA)]_2 (5) complexes (acac = acetylacetonato, OAc = acetate, and TFA = trifluoroacetate) was studied experimentally and theoretically. Hydrogen−deuterium (H/D) exchange between benzene and CD_(3)COOD solvent catalyzed by 4 (ΔH^‡ = 28.3 ± 1.1 kcal/mol, ΔS^‡ = 3.9 ± 3.0 cal K^(−1) mol^(−1)) results in a monotonic increase of all benzene isotopologues, suggesting that once benzene coordinates to the iridium center, there are multiple H/D exchange events prior to benzene dissociation. B3LYP density functional theory (DFT) calculations reveal that this benzene isotopologue pattern is due to a rate-determining step that involves acetate ligand dissociation and benzene coordination, which is then followed by heterolytic C−H bond cleavage to generate an iridium-phenyl intermediate. A synthesized iridium-phenyl intermediate was also shown to be competent for H/D exchange, giving similar rates to the proposed catalytic systems. This mechanism nicely explains why hydroarylation between benzene and alkenes is suppressed in the presence of acetic acid when catalyzed by [Ir(μ-acac-O,O,C^3)(acac-O,O)(acac-C^3)]_2 (3) (Matsumoto et al. J. Am. Chem. Soc. 2000, 122, 7414). Benzene H/D exchange in CF_(3)COOD solvent catalyzed by 5 (ΔH^‡ = 15.3 ± 3.5 kcal/mol, ΔS^‡ = −30.0 ± 5.1 cal K^(−1) mol^(−1)) results in significantly elevated H/D exchange rates and the formation of only a single benzene isotopologue, (C_(6)H_(5)D). DFT calculations show that this is due to a change in the rate-determining step. Now equilibrium between coordinated and uncoordinated benzene precedes a single rate-determining heterolytic C−H bond cleavage step

    Calculation of Band Edge Eigenfunctions and Eigenvalues of Periodic Potentials through the Quantum Hamilton - Jacobi Formalism

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    We obtain the band edge eigenfunctions and the eigenvalues of solvable periodic potentials using the quantum Hamilton - Jacobi formalism. The potentials studied here are the Lam{\'e} and the associated Lam{\'e} which belong to the class of elliptic potentials. The formalism requires an assumption about the singularity structure of the quantum momentum function pp, which satisfies the Riccati type quantum Hamilton - Jacobi equation, p2iddxp=2m(EV(x)) p^{2} -i \hbar \frac{d}{dx}p = 2m(E- V(x)) in the complex xx plane. Essential use is made of suitable conformal transformations, which leads to the eigenvalues and the eigenfunctions corresponding to the band edges in a simple and straightforward manner. Our study reveals interesting features about the singularity structure of pp, responsible in yielding the band edge eigenfunctions and eigenvalues.Comment: 21 pages, 5 table

    Effect of Surface Oxygen Complexes of Activated Carbon on the Adsorption of 2,4,6- Trinitrophenol

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    The adsorption isothenns for 2,4,6-trinitrophenol (picric acid) on five samples of coconut-based activated carbons (ACs) with varying. surface area have been studied. The results obtained show thatadsorption depends upon surface area but is not linearly related to it. The adsorption increases on oxidation with ammonium persulphate (NH4)2 S2 08) as well as on degassing at 600 °C. The resultshave been explained on the basis of the existence of surface carbonyl groups, where the 02 of thecarbonyl group interacts with pi electrons of the benzene ring of picric acid
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