Promotion of dropwise condensation of ethyl alcohol, methyl alcohol, and acetone by polytetrafluoroethylene

Coating condensing surfaces with thin layer of nonpolar Teflon results in dropwise condensation of polar organic vapor. Greater heat transfer coefficients are produced increasing effectiveness of condensing system. Investigation shows that vapors with strong dipole moment tend to condense dropwise

Preliminary investigation of effects of exposure to sulfur hexafluoride on tensile and yield strengths of aluminum and steel

Effects of sulfur hexafluoride on tensile and yield strengths of aluminum and steel with application to exhaust gases from rocket engine

Demonstration of hyper-programming in Java

We demonstrate the use of a hyper-programming system to build persistent Java applications in PJama, an orthogonally persistent version of Java. This allows program representations to contain type-safe links to persistent objects embedded directly within the source code. The potential benefits include greater potential for static program checking, improved efficiency, and reduced programming effort.Postprin

A Method for Greatly Reduced Edge Effects and Crosstalk in CCT Magnets

Iron-free CCT magnet design offers many advantages, one being the excellent field quality and the absence of multipole components. However, edge effects are present, although they tend to integrate out over the length of the magnet. Many modern accelerator applications, however, require that these magnets are placed in an area of rapidly varying optics parameters, so magnets with greatly reduced edge effects have an advantage. We have designed such a magnet (a quadrupole) by adding multipole components of the opposite sign to the edge distortions of the magnet. A possible application could be the final focus magnets of the FCC-ee, where beam sizes at the entry and exit point of the magnets vary by large factors. We have then used this technique to effectively eliminate cross talk between adjacent final focus quadrupoles for the incoming and outgoing beams.Comment: Poster presented at MT25,25th International Conference on Magnet Technology, Amsterdam, August 27 - September 1, 201

The Factorisation of Chemical Graphs and Their Polynomials: A Polynomial Diyision Approach

Recent advances in computational methods allow the Characteristic and Acyclic Polynomials of a Chemical Graph to be calculated easily. A consequence of this is that checking for a zero-value remainder after computer assisted polynomial division is sometimes the simplest way of testing suspected factors of a chemical graph. The technique is simple enough to apply on a routine basis when characteristic or acyclic polynomials need to be solved. Among appropriate choices for test are linear polyenes and rings, because their roots are already independently available in closed form and they do occur as factors in a significant number of structures. Examination of an arbitrary set of structures showed that the acyclic polynomials of non-cyclic structures tend to be the most easily factorisable, followed by characteristic polynomials of cyclic structures and (least easily factorisable) the acyclic polynomials of the same cyclic structures

Neutron Star Mergers Are the Dominant Source of the r-process in the Early Evolution of Dwarf Galaxies

There are many candidate sites of the r-process: core-collapse supernovae (including rare magnetorotational core-collapse supernovae), neutron star mergers, and neutron star/black hole mergers. The chemical enrichment of galaxies---specifically dwarf galaxies---helps distinguish between these sources based on the continual build-up of r-process elements. This technique can distinguish between the r-process candidate sites by the clearest observational difference---how quickly these events occur after the stars are created. The existence of several nearby dwarf galaxies allows us to measure robust chemical abundances for galaxies with different star formation histories. Dwarf galaxies are especially useful because simple chemical evolution models can be used to determine the sources of r-process material. We have measured the r-process element barium with Keck/DEIMOS medium-resolution spectroscopy. We present the largest sample of barium abundances (almost 250 stars) in dwarf galaxies ever assembled. We measure [Ba/Fe] as a function of [Fe/H] in this sample and compare with existing [alpha/Fe] measurements. We have found that a large contribution of barium needs to occur at more delayed timescales than core-collapse supernovae in order to explain our observed abundances, namely the significantly more positive trend of the r-process component of [Ba/Fe] vs. [Fe/H] seen for [Fe/H] <~ -1.6 when compared to the [Mg/Fe] vs. [Fe/H] trend. We conclude that neutron star mergers are the most likely source of r-process enrichment in dwarf galaxies at early times.Comment: Accepted to ApJ on 2018 October 2

Remarks Upon Recognising Genus and Possible Shapes of Chemical Cages in the Form of Polyhedra, Tori and Klein Bottles

Some of the problems associated with recognising and classifying cage structures are reviewed briefly and discussed. Some new structures are considered, including Klein bottles (polyhex and azulenoidl and \u27neal\u27 polyhex double tori