Optimum rendezvous guidance study Interim report

Minimum fuel rendezvous guidance of powered interceptor from parking orbit to target in coplanar circular orbi

Numerical Calculation of Bessel Functions

A new computational procedure is offered to provide simple, accurate and flexible methods for using modern computers to give numerical evaluations of the various Bessel functions. The Trapezoidal Rule, applied to suitable integral representations, may become the method of choice for evaluation of the many Special Functions of mathematical physics.Comment: 10 page

Methods of regularization for computing orbits in celestial mechanics

Numerical and analytical methods for orbit computation in celestial mechanics during and beyond collision by introduction of regularized coordinate

Typhoid fever imported from Mexico to Switzerland. Studies on R factor mediated chloramphenicol resistance

A case of typhoid fever caused by Salmonella typhi occurred in Geneva. The patient was probably infected in Mexico City. The strain isolated from this patient corresponds with the description of the Mexican S. typhi strain, since it is a degraded Vi-strain resistant to chloramphenicol, streptomycin, sulphonamides and tetracyclines. It carried an fi− transferable R factor with a CSSuT resistance pattern. It can be accepted that this case forms part of the Mexican outbreak of chloramphenicol-resistant typhoid fever which has already been observed in visitors to Mexico from England and the United State

Scaling laws for the photo-ionisation cross section of two-electron atoms

The cross sections for single-electron photo-ionisation in two-electron atoms show fluctuations which decrease in amplitude when approaching the double-ionisation threshold. Based on semiclassical closed orbit theory, we show that the algebraic decay of the fluctuations can be characterised in terms of a threshold law $\sigma \propto |E|^{\mu}$ as $E \to 0_-$ with exponent $\mu$ obtained as a combination of stability exponents of the triple-collision singularity. It differs from Wannier's exponent dominating double ionisation processes. The details of the fluctuations are linked to a set of infinitely unstable classical orbits starting and ending in the non-regularisable triple collision. The findings are compared with quantum calculations for a model system, namely collinear helium.Comment: 4 pages, 1 figur

Generalization of the Birkhoff Regularization of the Three Space Bodies Problem

Generalization of space restricted three-body problem by spinor regularizatio

The oxidation of organo-boron compounds using electrochemically generated peroxodicarbonate

Peroxodicarbonate represents a green and largely underexplored oxidizer generated electrochemically from aqueous carbonate solutions. Through state-of-the-art electrolyzer technology, highly concentrated solutions have now become accessible. These were successfully employed as green oxidizer in deborolative hydroxylations. A plethora of phenols and alcohols have thus been synthesized in up to 99 % from organoboron compounds using only green and non-toxic solvents. This transformation was successfully scaled-up to multi-gram batch sizes

Regularization of the circular restricted three-body problem using 'similar' coordinate systems

The regularization of a new problem, namely the three-body problem, using 'similar' coordinate system is proposed. For this purpose we use the relation of 'similarity', which has been introduced as an equivalence relation in a previous paper (see \cite{rom11}). First we write the Hamiltonian function, the equations of motion in canonical form, and then using a generating function, we obtain the transformed equations of motion. After the coordinates transformations, we introduce the fictitious time, to regularize the equations of motion. Explicit formulas are given for the regularization in the coordinate systems centered in the more massive and the less massive star of the binary system. The 'similar' polar angle's definition is introduced, in order to analyze the regularization's geometrical transformation. The effect of Levi-Civita's transformation is described in a geometrical manner. Using the resulted regularized equations, we analyze and compare these canonical equations numerically, for the Earth-Moon binary system.Comment: 24 pages, 7 figures; Accepted for publication in Astrophysics and Space Scienc

Foreign Body Infection: Role of Fibronectin as a Ligand for the Adherence of Staphylococcus aureus

Foreign bodies made of polymethylmethacrylate coverslips were implanted subcutaneously into guinea pigs, were explanted four weeks later, and were tested for in vitro adherence of Staphylococcus aureus strain Wood 46. In the presence of serum, the level of staphylococcal adherence to explanted coverslips was 20 times higher than that of adherence to unimplanted coverslips. Adherence to explanted coverslips was caused by fibronectin deposits on the foreign body surface and was inhibited in a dose-related fashion by specific antibodies to fibronecti