Rensselaer Polytechnic Institute

About: Rensselaer Polytechnic Institute is a education organization based out in Troy, New York, United States. It is known for research contribution in the topics: Terahertz radiation & Population. The organization has 19024 authors who have published 39922 publications receiving 1414699 citations. The organization is also known as: RPI & Rensselaer Institute.

Plate-boundary deformation associated with the great Sumatra–Andaman earthquake

Abstract: The Sumatra–Andaman earthquake of 26 December 2004 is the first giant earthquake (moment magnitude M_w > 9.0) to have occurred since the advent of modern space-based geodesy and broadband seismology. It therefore provides an unprecedented opportunity to investigate the characteristics of one of these enormous and rare events. Here we report estimates of the ground displacement associated with this event, using near-field Global Positioning System (GPS) surveys in northwestern Sumatra combined with in situ and remote observations of the vertical motion of coral reefs. These data show that the earthquake was generated by rupture of the Sunda subduction megathrust over a distance of >1,500 kilometres and a width of <150 kilometres. Megathrust slip exceeded 20 metres offshore northern Sumatra, mostly at depths shallower than 30 kilometres. Comparison of the geodetically and seismically inferred slip distribution indicates that ~30 per cent additional fault slip accrued in the 1.5 months following the 500-second-long seismic rupture. Both seismic and aseismic slip before our re-occupation of GPS sites occurred on the shallow portion of the megathrust, where the large Aceh tsunami originated. Slip tapers off abruptly along strike beneath Simeulue Island at the southeastern edge of the rupture, where the earthquake nucleated and where an M_w = 7.2 earthquake occurred in late 2002. This edge also abuts the northern limit of slip in the 28 March 2005 M_w = 8.7 Nias–Simeulue earthquake.

Composite structures for the enhancement of nonlinear-optical susceptibility

Abstract: Calculations of the nonlinear-optical behavior are developed for model composites of nanospheres with a metallic core and nonlinear shell or with a nonlinear core and metallic shell suspended in a nonlinear medium. Optical phase conjugation is shown to be enhanced from each nonlinear region because the optical field can be concentrated in both the interior and the exterior neighborhoods of the particle and magnified at the surface-mediated plasmon resonance. For the model composite with a metallic core, a limited range of resonance tunability can be achieved by adjustment of shell thickness; the frequency range is dependent on the dielectric dispersion of the metal. For the composite with a metallic shell instead of a metallic core, this restriction is reduced so that tunability from ultraviolet to infrared can be attained. Enhancement of the phase-conjugate signal is calculated for the electrostrictive mechanism dominant in the microsecond time scale and for the electronic mechanism dominant in the picosecond time scale. Calculations based on the dielectric functions for gold and for aluminum indicate that phase-conjugate reflectivity enhancements of 108 can be achieved. The imaginary components of the composite dielectric functions are shown to limit the magnitude of the field enhancement at the surface-plasmon resonance and determine the absorption and figure of merit of the composite.

The relationship between total quality management practices and organizational culture

Abstract: Purpose – This empirical study explores the relationship between total quality management (TQM) practices and organizational culture with the purpose of identifying the particular cultures that determine the successful implementation of TQM practices. Specifically, it tests two competing views on the relationship; the unitarist and pluralist views.Design/methodology/approach – The empirical data was drawn from 194 organizations in Australia. The research model employs the Malcolm Baldrige National Quality Award criteria as TQM framework and builds on the competing values model to frame organizational culture. The data was analysed using structural equation modelling technique.Findings – The findings support the pluralist view, wherein different subsets of TQM practices are determined by different types of cultures. Interestingly, hierarchical culture was found to have a significant relationship with certain practices of TQM. Additionally, the findings indicate that although the cultural factors underpinni...

Light-Emitting Diodes

Abstract: Inorganic semiconductor light-emitting diodes (LEDs) are environmentally benign and have found widespread use as indicator lights, mobile displays, large-area displays, signage applications, and lighting applications. The entire visible spectrum can be covered by light-emitting semiconductors: AlGaInP and AlGaInN compound semiconductors are capable of emission in the red-to-yellow wavelength range and violet-to-green wavelength range, respectively. For white light sources based on LEDs, the most common approach is the combination of a blue LED chip with a yellow phosphor. Alternatively, a group of red, green, and blue (RGB) LEDs can be used; such source allows for color tunability. White LEDs are currently used to replace incandescent and fluorescent sources. In this review, the properties of inorganic LEDs will be presented, including emission spectra, electrical characteristics, and current-flow patterns. Structures providing high internal quantum efficiency, namely heterostructures and multiple quantum well structures, will be discussed. Advanced techniques enhancing the external quantum efficiency will be reviewed, including die shaping (chip shaping) and surface roughening. Different approaches to white LEDs will be presented and figures-of-merit such as the color rendering index and luminous efficacy will be explained. Besides visible LEDs, the technical challenges of newly evolving deep ultraviolet (UV) LEDs will be introduced. Finally, the packaging of low-power and high-power LED dies will be discussed.

Are perseverance and self‐efficacy costless? Assessing entrepreneurs' regretful thinking

Abstract: New business formation is a formidable and daunting task, which may require personal perseverance and self-efficacy. If this is indeed the case, will entrepreneurs and non-entrepreneurs differ on such attributes? Also, if high levels of perseverance and self-efficacy help entrepreneurs to overcome setbacks, snags, and obstacles, do these positive attributes co-occur with significant personal costs, such as the tendency to experience regretful thinking? This study uses a random sample of 217 patent inventors in the medical industry (surgery devices) to address these questions. Results indicate that entrepreneurs score significantly higher on self-efficacy and on two distinct aspects of perseverance—perceived control over adversity and perceived responsibility regarding outcome of adversity—than did non-entrepreneurs. Also, although entrepreneurs report the same number of regrets, their regrets are stronger and are qualitatively different from those reported by non-entrepreneurs. These findings suggest that perseverance and self-efficacy do indeed co-occur with regretful thinking. Finally, post hoc analysis reveals that the higher the overall perseverance scores of patent inventors, the higher their annual earnings. We conclude by examining the implications for theory, researcher, and practice. Copyright © 2005 John Wiley & Sons, Ltd.