On dispersion and characteristic motions of temperature rate dependent materials

Three dimensional theory of thermomechanical material developed using techniques of continuum mechanics and law of thermodynamic

Transit-time devices as local oscillators for frequencies above 100 GHz

Very promising preliminary experimental results have been obtained from GaAs IMPATT diodes at F-band frequencies (75 mW, 3.5 percent at 111.1 GHz and 20 mW, 1.4 percent at 120.6 GHz) and from GaAs TUNNETT diodes at W-band frequencies (26 mW, 1.6 percent at 87.2 GHz and 32 mW, 2.6 percent at 93.5 GHz). These results indicate that IMPATT, MITATT and TUNNETT diodes have the highest potential of delivering significant amounts of power at Terahertz frequencies. As shown recently, the noise performance of GaAs W-band IMPATT diodes can compete with that of Gunn devices. Since TUNNETT diodes take advantage of the quieter tunnel injection, they are expected to be especially suited for low-noise local oscillators. This paper will focus on the two different design principles for IMPATT and TUNNETT diodes, the material parameters involved in the design and some aspects of the present device technology. Single-drift flat-profile GaAs D-band IMPATT diodes had oscillations up to 129 GHz with 9 mW, 0.9 percent at 128.4 GHz. Single-drift GaAs TUNNETT diodes had oscillations up to 112.5 GHz with 16 mW and output power levels up to 33 mW and efficiencies up to 3.4 percent around 102 GHz. These results are the best reported so far from GaAs IMPATT and TUNNETT diodes

Learning from Beirut: From Modernism to Contemporary Architecture

This paper will discuss the developments in architecture in Lebanon in the second half of the Twentieth century. Lebanon presents one of the interesting ‘laboratories' of the different tendencies and movements of this pastcentury, beginning with Modernism and its gradual assimilation, to Postmodernism and more current trends,in a context that presents a fertile field for experimentation. The questions of meaning, context, relations to place and tradition, have all played a part in the development ofarchitecture in Lebanon, without necessarily achieving their desired goals, especially in the current climate of globalization. The loss of material identity that many regions around the world have experienced is reflected in the case of Lebanon, exacerbated here by political and social conflicts. This paper argues that the attempts to reinject material forms with a measure of ‘communicative' symbols or forms fails in the end to answer to this perpetual desire for ‘identity'

Effects of Internet Exclusion on the City of Detroit

Introduction The rise of Information Technology (IT) in the past 50 years has revolutionized many areas of human life and activity. Information Technology’s most obvious areas of impact are often those where they add a great and obvious value to a particular industry, and it is extremely difficult to find some aspect of life that has not changed since its inception. Some examples include the digitization of stock trading, the automation of factories and life-saving operations, and the enhanced communication and collaboration across public education, enterprise activity, and international affairs. However, what is often overlooked and understudied are the secondary and tertiary effects I.T. has on a particular aspect of human life. These can include such things as subjective feelings of inclusion, belonging, and generally having a “voice.” This research paper analyzes the effects of the rapid rise of I.T. in the city of Detroit, the disparity between I.T. in Detroit and its surrounding areas, as well as the effects this development has had on community engagement and citizenship. This paper will attempt to establish the existence of a digital divide between Detroit and its surrounding areas, as well as highlight the severity of the divide itself by using examples of relevant geographical areas and their associated overall Internet health. Other topics to be explored in this paper will include the effects of this divide on the citizens of Detroit, such as effects on healthcare and education quality and access and its downstream effects. Correlation of key demographic markers will be discussed in an attempt to establish the reason behind this divide. Finally, remedial efforts by both local, state, and federal institutions will be explored in order to see and decipher if these efforts are sustainable, making actual change, and helping to address the problem of Internet access, quality, and availability of hardware

Magnetic field induced singlet - triplet phase transition in quasi one-dimensional organic superconductors

We propose a theoretical model of quasi-one-dimensional superconductors, with attractive electron-electron interactions dominant in the singlet d-wave channel and sub-dominant in the p-wave channel. We discuss, in the mean field approximation, the effect of a magnetic field applied perpendicularly to the direction of the lowest conductivity. The lowest free energy phase corresponds to a singlet d-wave symmetry in low fields, but to a triplet symmetry in high fields. A first order singlet-triplet phase transition is expected at moderate applied fields of a few teslas. We propose to ascribe the recent critical field and NMR experimental data, observed in superconducting (TMTSF)2ClO4 to such an effect.Comment: 6 pages, 2 figures, accepted in EP

δ\delta meson effects on neutron stars in the modified quark-meson coupling model

The properties of neutron stars are investigated by including $\delta$ meson field in the Lagrangian density of modified quark-meson coupling model. The $\Sigma^-$ population with $\delta$ meson is larger than that without $\delta$ meson at the beginning, but it becomes smaller than that without $\delta$ meson as the appearance of $\Xi^-$. The $\delta$ meson has opposite effects on hadronic matter with or without hyperons: it softens the EOSes of hadronic matter with hyperons, while it stiffens the EOSes of pure nucleonic matter. Furthermore, the leptons and the hyperons have the similar influence on $\delta$ meson effects. The $\delta$ meson increases the maximum masses of neutron stars. The influence of $(\sigma^*,\phi)$ on the $\delta$ meson effects are also investigated.Comment: 10 pages, 6 figures, 4 table

History and development of validation with the ESP-r simulation program

It is well recognised that validation of dynamic building simulation programs is a long-term complex task. There have been many large national and international efforts that have led to a well-established validation methodology comprising analytical, inter-program comparison and empirical validation elements, and a significant number of tests have been developed. As simulation usage increases, driven by such initiatives as the European Energy Performance of Buildings Directive, such tests are starting to be incorporated into national and international standards. Although many program developers have run many of the developed tests, there does not appear to have been a systematic attempt to incorporate such tests into routine operation of the simulation programs. This paper reports work undertaken to address this deficiency. The paper summarizes the tests that have been applied to the simulation program ESP-r. These tests have been developed within International Energy Agency Annexes, within CEN standards, within various large-scale national projects, and by the UK's Chartered Institution of Building Services Engineers. The structure used to encapsulate the tests allows developers to ensure that recent code modifications have not resulted in unforeseen impacts on program predictions, and allows users to check for themselves against benchmarks