Transboundary Air Pollution in Europe: An Interactive Multicriteria Tradeoff Analysis

In this paper. the acid rain problem in Europe is discussed, stressing the transboundary tradeoffs between abatement costs of sulphur emission reduction and corresponding deposition levels in the different countries. An interactive decision support methodology is proposed which utilizes a powerful nonlinear multicriteria software package to evaluate various scenarios and tradeoffs. The concepts are illustrated using previously published data. The results from the tradeoff analysis show that reasonable deposition levels can be reached with limited transfers of funds between countries. The extent of these transfers can be controlled by selecting appropriate target levels for the criteria across countries

Analytical results for a Bessel function times Legendre polynomials class integrals

When treating problems of vector diffraction in electromagnetic theory, the evaluation of the integral involving Bessel and associated Legendre functions is necessary. Here we present the analytical result for this integral that will make unnecessary numerical quadrature techniques or localized approximations. The solution is presented using the properties of the Bessel and associated Legendre functions.Comment: 4 page

Exact solutions for the KdV6 and mKdV6 Equations via tanh-coth and sech Methods

The tanh-coth method is used to seek solutions to obtain solutions to the new integrable sixthorder Korteweg-de Vries equation (KdV6). Following the analogy between the Korteweg-de Vries equation (KdV) and the modified Korteweg-de Vries equation (MKdV) we construct a new system equivalent to KdV6 from which exact solutions to original equation and derived, during the sech method

Kinetic energy sum spectra in nonmesonic weak decay of hypernuclei

We evaluate the coincidence spectra in the nonmesonic weak decay (NMWD) \Lambda N\go nN of $\Lambda$ hypernuclei $^{4}_\Lambda$He, $^{5}_\Lambda$He, $^{12}_\Lambda$C, $^{16}_\Lambda$O, and $^{28}_\Lambda$Si, as a function of the sum of kinetic energies $E_{nN}=E_n+E_N$ for $N=n,p$. The strangeness-changing transition potential is described by the one-meson-exchange model, with commonly used parameterization. Two versions of the Independent-Particle Shell Model (IPSM) are employed to account for the nuclear structure of the final residual nuclei. They are: (a) IPSM-a, where no correlation, except for the Pauli principle, is taken into account, and (b) IPSM-b, where the highly excited hole states are considered to be quasi-stationary and are described by Breit-Wigner distributions, whose widths are estimated from the experimental data. All $np$ and $nn$ spectra exhibit a series of peaks in the energy interval 110 MeV $<E_{nN}<170$ MeV, one for each occupied shell-model state. The IPSM-a could be a pretty fair approximation for the light $^{4}_\Lambda$He and $^{5}_\Lambda$He hypernuclei. For the remaining, heavier, hypernuclei it is very important, however, to take into account the spreading in strength of the deep-hole states, and bring into play the IPSM-b approach. Notwithstanding the nuclear model that is employed the results depend only very weakly on the details of the dynamics involved in the decay process proper. We propose that the IPSM is the appropriate lowest-order approximation for the theoretical calculations of the of kinetic energy sum spectra in the NMWD. It is in comparison to this picture that one should appraise the effects of the final state interactions and of the two-nucleon-induced decay mode.Comment: v1: 20 pages, 3 figures, 1 table, submitted for publication; v2: minor corrections, improved figures, published versio

Molecular Mechanism of Cyclodextrin Mediated Cholesterol Extraction

The depletion of cholesterol from membranes, mediated by β-cyclodextrin (β-CD) is well known and documented, but the molecular details of this process are largely unknown. Using molecular dynamics simulations, we have been able to study the CD mediated extraction of cholesterol from model membranes, in particular from a pure cholesterol monolayer, at atomic resolution. Our results show that efficient cholesterol extraction depends on the structural distribution of the CDs on the surface of the monolayer. With a suitably oriented dimer, cholesterol is extracted spontaneously on a nanosecond time scale. Additional free energy calculations reveal that the CDs have a strong affinity to bind to the membrane surface, and, by doing so, destabilize the local packing of cholesterol molecules making their extraction favorable. Our results have implications for the interpretation of experimental measurements, and may help in the rational design of efficient CD based nano-carriers

A Hybrid Simulation Model to Predict the Steady-State Thermal Profile of Hermetic Reciprocating Compressors

Numerical simulation models are paramount to design compressors that follow reliability and efficiency requirements. This paper presents a simulation model to predict the steady-state thermal profile of hermetic reciprocating compressors. A finite element method is used to compute the temperature distribution of the solid components and the fluid in the suction and discharge lines, whereas a lumped-parameter formulation is used to evaluate the internal environment temperature and the gas temperature at the end of the compression cycle. The heat transfer between the gas and the solid components is predicted using imposed convective heat transfer coefficients; some of which are estimated using heat transfer correlations, and others calibrated using experimental data and a genetic optimization algorithm. The numerical results were validated by comparisons with experimental data for different operating conditions and rotation speeds, showing that the model can be used to predict the compressor thermal profile in the entire application envelope. The low computational cost of the model enables its application to carry out sensitivity analysis and to assess thermal management alternatives to improve the compressor reliability or thermodynamic performance

Bifurcation Analysis Using Rigorous Branch and Bound Methods

For the study of nonlinear dynamic systems, it is important to locate the equilibria and bifurcations occurring within a specified computational domain. This paper proposes a new approach for solving these problems and compares it to the numerical continuation method. The new approach is based upon branch and bound and utilizes rigorous enclosure techniques to yield outer bounding sets of both the equilibrium and local bifurcation manifolds. These sets, which comprise the union of hyper-rectangles, can be made to be as tight as desired. Sufficient conditions for the existence of equilibrium and bifurcation points taking the form of algebraic inequality constraints in the state-parameter space are used to calculate their enclosures directly. The enclosures for the bifurcation sets can be computed independently of the equilibrium manifold, and are guaranteed to contain all solutions within the computational domain. A further advantage of this method is the ability to compute a near-maximally sized hyper-rectangle of high dimension centered at a fixed parameter-state point whose elements are guaranteed to exclude all bifurcation points. This hyper-rectangle, which requires a global description of the bifurcation manifold within the computational domain, cannot be obtained otherwise. A test case, based on the dynamics of a UAV subject to uncertain center of gravity location, is used to illustrate the efficacy of the method by comparing it with numerical continuation and to evaluate its computational complexity