Generalised Einstein mass-variation formulae: II Superluminal relative frame velocities

AbstractIn part I of this paper we have deduced generalised Einstein mass variation formulae assuming relative frame velocities v<c. Here we present corresponding new expressions for superluminal relative frame velocities v>c. We again use the notion of the residual mass m0(v) which for v>c is defined by the equation m(v)=m0(v)[(v/c)2-1]-1/2 for the actual mass m(v). The residual mass is essentially the actual mass with the Einstein factor removed, and we emphasise that we make no restrictions on m0(v). Using this formal device we deduce corresponding new mass variation formulae applicable to superluminal relative frame velocities, assuming only the extended Lorentz transformations and their consequences, and two invariants that are known to apply in special relativity. The present authors have previously speculated a dual framework such that both the rest mass m0∗ and the residual mass at infinite velocity m∞∗ (by which we mean p∞∗/c, assuming finite momentum at infinity) are equally important parameters in the specification of mass as a function of its velocity, and the two arbitrary constants can be so determined. The new formulae involving two arbitrary constants may also be exploited so that the mass remains finite at the speed of light, and two distinct mass profiles are determined as functions of their velocity with the rest mass assumed to be alternatively prescribed at the origin of either frame. The two profiles so obtained (M(U),m(u)) and (M∗(U),m∗(u)) although distinct have a common ratio M(U)/M∗(U)=m(u)/m∗(u) that is a function of v>c, indicating that observable mass depends upon the frame in which the rest mass is prescribed

Continuum modelling of gigahertz nano-oscillators

Fullerenes and carbon nanotubes are of considerable interest throughout many scientific areas due to their unique and exceptional properties, such as low weight, high strength, flexibility, high thermal conductivity and chemical stability. These nanostructures have many potential applications in nano-devices. One concept that has attracted much attention is the creation of nano-oscillators, which can produce frequencies in the gigahertz range, for applications such as ultra-fast optical filters and nano-antennae. In this paper, we provide the underlying mechanisms of the gigahertz nano-oscillators and we review some recent results derived by the authors using the Lennard-Jones potential together with the continuum approach to mathematically model three different types of nano-oscillators including double-walled carbon nanotube, C60-nanotube and C60-nanotorus oscillators

An Introduction to Hard and Soft Data Fusion via Conceptual Spaces Modeling for Space Event Characterization

This paper describes an AFOSR-supported basic research program that focuses on developing a new framework for combining hard with soft data in order to improve space situational awareness. The goal is to provide, in an automatic and near real-time fashion, a ranking of possible threats to blue assets (assets trying to be protected) from red assets (assets with hostile intentions). The approach is based on Conceptual Spaces models, which combine features from traditional associative and symbolic cognitive models. While Conceptual Spaces are revolutionary, they lack an underlying mathematical framework. Several such frameworks have attempted to represent Conceptual Spaces, but by far the most robust is the model developed by Holender. His model utilizes integer linear programming in order to obtain an overall similarity value between observations and concepts that support the formation of hypotheses. This paper will describe a method for building Conceptual Spaces models for threats that utilizes ontologies as a means to provide a clear semantic foundation for this inferencing process; in particular threat ontologies and space domain ontologies are developed and employed in this approach. A space situational awareness use-case is presented involving a kinetic kill scenario and results are shown to assess the performance of this fusion-based inferencing framework

Flow through a circular tube with a permeable Navier slip boundary

For Newtonian fluid flow in a right circular tube, with a linear Navier slip boundary, we show that a second flow field arises which is different to conventional Poiseuille flow in the sense that the corresponding pressure is quadratic in its dependence on the length along the tube, rather than a linear dependence which applies for conventional Poiseuille flow. However, assuming that the quadratic pressure is determined, say from known experimental data, then the new solution only exists for a precisely prescribed permeability along the boundary. While this cannot occur for conventional pipe flow, for fluid flow through carbon nanotubes embedded in a porous matrix, it may well be an entirely realistic possibility, and could well explain some of the high flow rates which have been reported in the literature. Alternatively, if the radial boundary flow is prescribed, then the new flow field exists only for a given quadratic pressure. Our primary purpose here is to demonstrate the existence of a new pipe flow field for a permeable Navier slip boundary and to present a numerical solution and two approximate analytical solutions. The maximum flow rate possible for the new solution is precisely twice that for the conventional Poiseuille flow, which occurs for constant inward directed flow across the boundary

Associations of coronary artery calcified plaque density with mortality in type 2 diabetes: the Diabetes Heart Study

Abstract Background Coronary artery calcified plaque (CAC) is strongly predictive of cardiovascular disease (CVD) events and mortality, both in general populations and individuals with type 2 diabetes at high risk for CVD. CAC is typically reported as an Agatston score, which is weighted for increased plaque density. However, the role of CAC density in CVD risk prediction, independently and with CAC volume, remains unclear. Methods We examined the role of CAC density in individuals with type 2 diabetes from the family-based Diabetes Heart Study and the African American-Diabetes Heart Study. CAC density was calculated as mass divided by volume, and associations with incident all-cause and CVD mortality [median follow-up 10.2 years European Americans (n = 902, n = 286 deceased), 5.2 years African Americans (n = 552, n = 93 deceased)] were examined using Cox proportional hazards models, independently and in models adjusted for CAC volume. Results In European Americans, CAC density, like Agatston score and volume, was consistently associated with increased risk of all-cause and CVD mortality (p ≤ 0.002) in models adjusted for age, sex, statin use, total cholesterol, HDL, systolic blood pressure, high blood pressure medication use, and current smoking. However, these associations were no longer significant when models were additionally adjusted for CAC volume. CAC density was not significantly associated with mortality, either alone or adjusted for CAC volume, in African Americans. Conclusions CAC density is not associated with mortality independent from CAC volume in European Americans and African Americans with type 2 diabetes

Indole-containing arene-ruthenium complexes with broad spectrum activity against antibiotic-resistant bacteria

Antimicrobial resistant (AMR) bacteria are emerging and spreading globally, threatening our ability to treat common infectious diseases. The development of new classes of antibiotics able to kill or inhibit the growth of such AMR bacteria through novel mechanisms of action is therefore urgently needed. Here, a new family of indole-containing arene ruthenium organometallic compounds are screened against several bacterial species and drug resistant strains. The most active complex [(p-cym)Ru(O-cyclohexyl-1H-indole-2-carbothioate)Cl] (3) shows growth inhibition and bactericidal activity against different organisms (Acinetobacter baumannii, Mycobacterium abscessus, Mycobacterium tuberculosis, Staphylococcus aureus, Salmonella enterica serovar typhi and Escherichia coli), demonstrating broad-spectrum inhibitory activity. Importantly, this compound series exhibits low toxicity against human cells. Owing to the novelty of the antibiotic family, their moderate cytotoxicity, and their inhibitory activity against Gram positive, Gram negative and acid-fast, antibiotic resistant microorganisms, this series shows significant promise for further development

The Security imaginary: Explaining military isomorphism

This article proposes the notion of a security imaginary as a heuristic tool for exploring military isomorphism (the phenomenon that weapons and military strategies begin to look the same across the world) at a time when the US model of defence transformation is being adopted by an increasing number of countries. Built on a critical constructivist foundation, the security-imaginary approach is contrasted with rationalist and neo-institutionalist ways of explaining military diffusion and emulation. Merging cultural and constructivist themes, the article offers a ‘strong cultural’ argument to explain why a country would emulate a foreign military model and how this model is constituted in and comes to constitute a society’s security imaginary.Web of Scienc