Carter-like constants of the motion in Newtonian gravity and electrodynamics

For a test body orbiting an axisymmetric body in Newtonian gravitational theory with multipole moments Q_L, (and for a charge in a non-relativistic orbit about a charge distribution with the same multipole moments) we show that there exists, in addition to the energy and angular momentum component along the symmetry axis, a conserved quantity analogous to the Carter constant of Kerr spacetimes in general relativity, if the odd-L moments vanish, and the even-L moments satisfy Q_2L = m (Q_2/m)^L. Strangely, this is precisely the relation among mass moments enforced by the no-hair theorems of rotating black holes. By contrast, if Newtonian gravity is supplemented by a multipolar gravitomagnetic field, whose leading term represents frame-dragging (or if the electrostatic field is supplemented by a multipolar magnetic field), we are unable to find an analogous Carter-like constant. This further highlights the very special nature of the Kerr geometry of general relativity.Comment: 4 page

Study of a water-vapor electrolysis unit

Sulfuric acid type water vapor electrolysis module for oxygen generation in advanced life support system

Continuous catalytic decomposition of methane

Water is conserved by employing sequence of reactions whereby 75 percent of methane from Sabatier reaction is decomposed to solid carbon and hydrogen; hydrogen is then separated from residual methane and utilized in usual Sabatier reaction to reduce remaining metabolic carbon dioxide

A Distribution Services Approach for Developing Effective Competitive Strategies Against Big Box Retailers

According to one theoretical approach, the primary economic function of retailers is to deliver products together with distribution services. We use this framework to identify competitive niches for smaller retailers competing against big box stores. We compare the distribution services offered by the Home Depot versus smaller retailers using both in-store measures and consumer perception data, and the relative importance of distribution services as determinants of store choice. The results show that the Home Depot’s superiority in pricing and assortment attracts a significant market, but smaller retailers can secure niche markets by delivering higher levels of ambiance and information

A New Look at Industrial Sales and its Requisite Competencies

Although industrial sales is widely discussed in both practitioner and academic circles, no clear definition of “industrial” has been established. We present a definition of industrial sales that distinguishes it from other sales domains, and we draw from a panel of industrial sales executives and a random sample of industrial sales managers to generate and evaluate the importance of a comprehensive list of knowledge, skills, and value competencies that are required for success in industrial sales. Technical competencies, while important, were rated relatively less so than selling- and customer-related competencies. Among other recommendations, we implore industrial sales executives to incorporate a global mindset into their sales organization, and we challenge academics to extend personal selling beyond the business school to engineering, computer science, and other technical disciplines from where industrial salespeople often recruit

A retrospective analysis of responsible innovation for low-technology innovation in the Global South

This is the final version. Available from the publisher via the DOI in this record.The role of low-technology innovation in addressing global challenges is undervalued. Responsible innovation (RI) has the potential to direct low-technology innovation toward global challenges in the Global South, yet this possibility remains largely unexplored. Through a retrospective analysis, this article explores how researchers grapple with dimensions of an RI framework in a research project and highlights key areas for researchers to consider when involved with low-technology innovation in a development context. The analysis demonstrates that RI can structure discussion and create space for anticipation, reflection and engagement with stakeholders. However, even when researchers are committed to the idea of RI, it is difficult to enact in practice. Although RI places significant emphasis on inclusive and meaningful engagement as imagined by co-development and inclusive models of innovation, the deficit model of public engagement presents a formidable barrier. Surprisingly, low-technology innovators are likely to face the same struggles as high technology innovators with regards to engagement that allows end-users to shape the technology which may ultimately benefit them.Leverhulme TrustEngineering and Physical Science Research Council (EPSRC)Biotechnology and Biological Sciences Research Council (BBSRC

Post-Newtonian gravitational radiation and equations of motion via direct integration of the relaxed Einstein equations. V. Evidence for the strong equivalence principle to second post-Newtonian order

Using post-Newtonian equations of motion for fluid bodies valid to the second post-Newtonian order, we derive the equations of motion for binary systems with finite-sized, non-spinning but arbitrarily shaped bodies. In particular we study the contributions of the internal structure of the bodies (such as self-gravity) that would diverge if the size of the bodies were to shrink to zero. Using a set of virial relations accurate to the first post-Newtonian order that reflect the stationarity of each body, and redefining the masses to include 1PN and 2PN self-gravity terms, we demonstrate the complete cancellation of a class of potentially divergent, structure-dependent terms that scale as s^{-1} and s^{-5/2}, where s is the characteristic size of the bodies. This is further evidence of the Strong Equivalence Principle, and supports the use of post-Newtonian approximations to derive equations of motion for strong-field bodies such as neutron stars and black holes. This extends earlier work done by Kopeikin.Comment: 14 pages, submitted to Phys. Rev. D; small changes to coincide with published versio

Free subgroups of one-relator relative presentations

Suppose that G is a nontrivial torsion-free group and w is a word over the alphabet G\cup\{x_1^{\pm1},...,x_n^{\pm1}\}. It is proved that for n\ge2 the group \~G= always contains a nonabelian free subgroup. For n=1 the question about the existence of nonabelian free subgroups in \~G is answered completely in the unimodular case (i.e., when the exponent sum of x_1 in w is one). Some generalisations of these results are discussed.Comment: V3: A small correction in the last phrase of the proof of Theorem 1. 4 page

Post-Newtonian gravitational radiation and equations of motion via direct integration of the relaxed Einstein equations. III. Radiation reaction for binary systems with spinning bodies

Using post-Newtonian equations of motion for fluid bodies that include radiation-reaction terms at 2.5 and 3.5 post-Newtonian (PN) order (O[(v/c)^5] and O[(v/c)^7] beyond Newtonian order), we derive the equations of motion for binary systems with spinning bodies. In particular we determine the effects of radiation-reaction coupled to spin-orbit effects on the two-body equations of motion, and on the evolution of the spins. For a suitable definition of spin, we reproduce the standard equations of motion and spin-precession at the first post-Newtonian order. At 3.5PN order, we determine the spin-orbit induced reaction effects on the orbital motion, but we find that radiation damping has no effect on either the magnitude or the direction of the spins. Using the equations of motion, we find that the loss of total energy and total angular momentum induced by spin-orbit effects precisely balances the radiative flux of those quantities calculated by Kidder et al. The equations of motion may be useful for evolving inspiraling orbits of compact spinning binaries.Comment: 19 pages, small corrections, equivalent to published versio