Low frequency vibration isolation technology for microgravity space experiments

The dynamic acceleration environment observed on Space Shuttle flights to date and predicted for the Space Station has complicated the analysis of prior microgravity experiments and prompted concern for the viability of proposed space experiments requiring long-term, low-g environments. Isolation systems capable of providing significant improvements in this environment exist, but have not been demonstrated in flight configurations. This paper presents a summary of the theoretical evaluation for two one degree-of-freedom (DOF) active magnetic isolators and their predicted response to both direct and base excitations, that can be used to isolate acceleration sensitive microgravity space experiments

Magnetic bearings with zero bias

A magnetic bearing operating without a bias field has supported a shaft rotating at speeds up to 12,000 rpm with the usual four power supplies and with only two. A magnetic bearing is commonly operated with a bias current equal to half of the maximum current allowable in its coils. This linearizes the relation between net force and control current and improves the force slewing rate and hence the band width. The steady bias current dissipates power, even when no force is required from the bearing. The power wasted is equal to two-thirds of the power at maximum force output. Examined here is the zero bias idea. The advantages and disadvantages are noted

Nonintrusive inertial vibration isolation technology for microgravity space experiments

The dynamic acceleration environment observed on Space Shuttle flights to date and predicted for the Space Station has complicated the analysis of prior microgravity experiments and prompted concern for the viability of proposed space experiments requiring long-term, microgravity environments. Isolation systems capable of providing significant improvements to this environment exist, but at present have not been demonstrated in flight configurations. A summary of the theoretical evaluation for two one degree-of-freedom (DOF) active magnetic isolators and their predicted response to both direct and base excitations is presented. These isolators can be used independently or in concert to isolate acceleration-sensitive microgravity space experiments, dependent on the isolation capability required for specific experimenter needs

Introduction and Acceptance of a Classical Charge Fiber Model (CFM) of Elementary Particles Evaluated by Means of an Online Tutorial-Based Survey

The introduction of a new classical model of elementary particles by Lucas and Bergman is studied using an online survey instrument. The model is based on finite-size, elastic, charged particles that take the form of charge fibers. The Charge Fiber Model of Elementary Particles (CFM) constitutes a fundamental departure from the current paradigm of Quantum Mechanics (QM) and the Standard Model (SM) of elementary particles. The survey familiarizes respondents with the basic principles and claims of the new model by means of an online tutorial, and queries respondents to gage their knowledge and opinion of the model (http://www.commonsensescience.org/survey). The analysis of the survey describes how experts in the field, or at least those who took the time to respond, regard the original and sweeping claims of the CFM. The response rate varied from a very low of 1.1% to a high of 29% among diverse scientific communities. This paper does not endorse the model, but considers the broader issue of how a theory representing a major departure from the status quo may be disseminated, perceived and accepted (or rejected) during its early stages. These issues are relevant to the ongoing development of a comprehensive young-earth creation model whose proponents, even with solid scientific and academic credentials, face a continuous struggle against the accepted scientific positions on origins, evolution and the age of the earth. Recognizing that scientific paradigms change over time provides incentive to evaluate models on the basis of their usefulness and to articulate our opinions of them in a manner that is both effective and nonoffensive

The Scholarly Role of Faculty Advisors in Student Engineering Competition Projects

Engineering faculty advisors at Cedarville University work closely with senior engineering students on the Solar Boat team to improve the boat’s performance each year and continue the team’s legacy of 7 wins in the last 10 years at the Solar Splash Competition. The faculty-student relationships are at times similar to that of a mentor and apprentice, and at other times similar to that of an engineering manager and a team of engineers. This mentor/manager approach allows us to maintain technical continuity from year to year between student teams, develop and maintain an increasingly sophisticated team knowledge base, coach the students through design issues beyond the scope of their classroom instruction, and model the diligence, effort, and attention to detail that are essential for success at the international level in student engineering competitions. Each year, the students on the Solar Boat Team seek to improve several aspects of the boat’s hull, electronics or drive system. They follow a design process that includes background research, developing a proposal, designing and modelling components and circuits for in-house manufacture or purchase from vendors. The unique nature of the project often leads to design solutions that are not commercially available and requires the students to work with potential vendors in a guided development process to produce something that does not currently exist. In this process, the students develop practical communication strategies with busy vendors, learn to assess the technical validity of potential solutions, and develop expertise in specific details of the project; areas that are sometimes beyond the experience or expertise of their advisors

How the U.S. Air Force Space Command Optimizes Long-Term Investment in Space Systems

Interfaces, 33, p.p. 1-14.United States Air Force Space Command spends billions of dollars each year acquiring and developing launch vehicles and space systems. The space systems in orbit must continually meet defensive and offensive requirements and remain interoperable over time. Space command can launch additional space systems only if it has a launch vehicle of sufficient capacity. Space planners using space and missile optimization analysis (SAMOA) consider a 24-year time horizon when determining which space assets and launch vehicles to fund and procure. A key tool which in SAMOA is an integer linear program called the space command optimizer of utility toolkit (SCOUT) that Space Command uses for long-range planning. SCOUT gives planner insight into the annual funding profiles needed to meet Space Command's acquisition goals. The 1999 portfolio of 74 systems will cost about #310 billion and includes systems that can lift satellites into orbit; yield information on space, surface, and subsurface events, activities, and threats; and destroy terrestrial, airborne, and space targets

On Galilean invariance and nonlinearity in electrodynamics and quantum mechanics

Recent experimental results on slow light heighten interest in nonlinear Maxwell theories. We obtain Galilei covariant equations for electromagnetism by allowing special nonlinearities in the constitutive equations only, keeping Maxwell's equations unchanged. Combining these with linear or nonlinear Schroedinger equations, e.g. as proposed by Doebner and Goldin, yields a Galilean quantum electrodynamics.Comment: 12 pages, added e-mail addresses of the authors, and corrected a misprint in formula (2.10

Effective Nucleon-Nucleon Interaction and Fermi Liquid Theory

We present two novel relations between the quasiparticle interaction in nuclear matter and the unique low momentum nucleon-nucleon interaction in vacuum. These relations provide two independent constraints on the Fermi liquid parameters of nuclear matter. Moreover, the new constraints define two combinations of Fermi liquid parameters, which are invariant under the renormalization group flow in the particle-hole channels. Using empirical values for the spin-independent Fermi liquid parameters, we are able to compute the major spin-dependent ones by imposing the new constraints as well as the Pauli principle sum rules.Comment: 4 pages, 5 figures, in Proc. 11th International Conference on Recent Progress in Many-Body Theories, Manchester, UK, July 9-13, 200