Generalized orientations and the Bloch invariant

Abstract. For compact hyperbolic 3-manifolds we lift the Bloch invariant defined by Neumann and Yang to an integral class in K3(C). Applying the Borel and the Bloch regulators, one gets back the volume and the Chern-Simons invariant of the manifold. We also discuss the non-compact case, in which there appears a Z/2-ambiguity

Common Carrier Regulation of Telecommunications Contracts and the Private Carrier Alternative

The Communications Act of 1934 requires, among other things, that telephone companies as common carriers make their services available to the general public at affordable rates. The Federal Communications Commission (FCC) has the authority to classify telephone services as common carriers as well as the ability to remove common carrier regulation to promote competition, satisfy consumer demand for individually tailored offerings, and avoid unnecessary regulatory costs. The Authors of this Article believe that the FCC should remove the common carrier regulation from certain long-distance service contracts and that such regulation is consistent with the deregulatory aims of the recent Telecommunications Act of 1996. The Article first reviews the judicial development of the common carrier definition which finds that a communications service is acting as a carrier if it either (1) actually holds out its service indiscriminately to the public or (2) is required to hold itself out because the public interest requires it. The Authors discuss the relatively broad application of this definition to new and existing telephone services in a series of cases. Part I concludes with an examination of recent instances where the FCC has used this definition to reclassify various telecommunications services as private or noncommon carriers/carriage. These instances fall into five categories: (1) satellite transponders, (2) broadcast-related services, (3) private land mobile services, (4) private microwave services, and (5) certain communications services, such as enhanced services and inside wiring. In Part II the Authors describe the growth and importance of individually negotiated telecommunications service contracts to the business operations of many customers. The Article then discusses the application of the private carrier alternative to these contracts. The Authors argue that there is nothing inherent in these contracts which requires that they be designated as common carrier services. The Authors offer several reasons why the FCC should no longer require that the contract services indiscriminately be held out to the public, including some of the potential benefits of removing this regulation. The Authors feel that classifying the service contracts as private would promote competition and innovation, as well as reduce regulatory costs

Common Carrier Regulation of Telecommunications Contracts and the Private Carrier Alternative

The Communications Act of 1934 requires, among other things, that telephone companies as common carriers make their services available to the general public at affordable rates. The Federal Communications Commission (FCC) has the authority to classify telephone services as common carriers as well as the ability to remove common carrier regulation to promote competition, satisfy consumer demand for individually tailored offerings, and avoid unnecessary regulatory costs. The Authors of this Article believe that the FCC should remove the common carrier regulation from certain long-distance service contracts and that such regulation is consistent with the deregulatory aims of the recent Telecommunications Act of 1996. The Article first reviews the judicial development of the common carrier definition which finds that a communications service is acting as a carrier if it either (1) actually holds out its service indiscriminately to the public or (2) is required to hold itself out because the public interest requires it. The Authors discuss the relatively broad application of this definition to new and existing telephone services in a series of cases. Part I concludes with an examination of recent instances where the FCC has used this definition to reclassify various telecommunications services as private or noncommon carriers/carriage. These instances fall into five categories: (1) satellite transponders, (2) broadcast-related services, (3) private land mobile services, (4) private microwave services, and (5) certain communications services, such as enhanced services and inside wiring. In Part II the Authors describe the growth and importance of individually negotiated telecommunications service contracts to the business operations of many customers. The Article then discusses the application of the private carrier alternative to these contracts. The Authors argue that there is nothing inherent in these contracts which requires that they be designated as common carrier services. The Authors offer several reasons why the FCC should no longer require that the contract services indiscriminately be held out to the public, including some of the potential benefits of removing this regulation. The Authors feel that classifying the service contracts as private would promote competition and innovation, as well as reduce regulatory costs

Combustion waves in a model with chain branching reaction and their stability

In this paper the travelling wave solutions in the adiabatic model with two-step chain branching reaction mechanism are investigated both numerically and analytically in the limit of equal diffusivity of reactant, radicals and heat. The properties of these solutions and their stability are investigated in detail. The behaviour of combustion waves are demonstrated to have similarities with the properties of nonadiabatic one-step combustion waves in that there is a residual amount of fuel left behind the travelling waves and the solutions can exhibit extinction. The difference between the nonadiabatic one-step and adiabatic two-step models is found in the behaviour of the combustion waves near the extinction condition. It is shown that the flame velocity drops down to zero and a standing combustion wave is formed as the extinction condition is reached. Prospects of further work are also discussed.Comment: pages 32, figures 2

Synchronization of organ pipes: experimental observations and modeling

We report measurements on the synchronization properties of organ pipes. First, we investigate influence of an external acoustical signal from a loudspeaker on the sound of an organ pipe. Second, the mutual influence of two pipes with different pitch is analyzed. In analogy to the externally driven, or mutually coupled self-sustained oscillators, one observes a frequency locking, which can be explained by synchronization theory. Further, we measure the dependence of the frequency of the signals emitted by two mutually detuned pipes with varying distance between the pipes. The spectrum shows a broad ``hump'' structure, not found for coupled oscillators. This indicates a complex coupling of the two organ pipes leading to nonlinear beat phenomena.Comment: 24 pages, 10 Figures, fully revised, 4 big figures separate in jpeg format. accepted for Journal of the Acoustical Society of Americ

Crystallographic structure of ultrathin Fe films on Cu(100)

We report bcc-like crystal structures in 2-4 ML Fe films grown on fcc Cu(100) using scanning tunneling microscopy. The local bcc structure provides a straightforward explanation for their frequently reported outstanding magnetic properties, i.e., ferromagnetic ordering in all layers with a Curie temperature above 300 K. The non-pseudomorphic structure, which becomes pseudomorphic above 4 ML film thickness is unexpected in terms of conventional rules of thin film growth and stresses the importance of finite thickness effects in ferromagnetic ultrathin films.Comment: 4 pages, 3 figures, RevTeX/LaTeX2.0