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 & Finite element method. The organization has 19024 authors who have published 39922 publications receiving 1414699 citations. The organization is also known as: RPI & Rensselaer Institute.

Dissolution, growth and survival of zircons during crustal fusion: kinetic principals, geological models and implications for isotopic inheritance

Abstract: Finite difference numerical simulations were used to characterise the rates of diffusion-controlled dissolution and growth of zircon in melts of granitic composition under geologically realistic conditions. The simulations incorporated known solubility and Zr diffusivity relationships for melts containing 3 wt% dissolved H2O and were carried out in both one and thre dimensions under conditions of constant temperature, linearly time-dependent temperature and for a variety of host system thermal histories. The rate of zircon dissolution at constant temperature depends systematically on time (t½−12;), temperature (exp T−1) and degree of undersaturation of the melt with respect to zircon (in ppm Zr). Linear dissolution and growth rates fall in the range 10−19 10−15 cm s−1 at temperatures of 650-850°C. Radial rates are strongly dependent on crystal size (varying in inverse proportion to the radius, r): for r>30 μm, dissolution and growth rates fall between 10−17 and 10−13 cm s−1. During crustal magmatism, the chances of survival for relict cores of protolith zircons depend on several factors, the most important of which are: the initial radius of the zircon; the intensity and duration of the magmatic event; and the volume of the local melt reservoir with which the zircon interacts. In general, only the largest protolith zircons (>120 μm radius) are likely to survive magmatic events exceeding 850°C. Conversely, only the smallest zircons (<50 μm radius) are likely to be completely consumed during low-temperature anatexis (i.e. not exceeding ≍700°C).The effects of stirring the zircon-melt system are unimportant to dissolution and growth behaviour; except under circumstances of extreme shearing (e.g. filter pressing?), zircon dissolution is controlled by diffusion of Zr in the melt.

Free-space electro-optics sampling of mid-infrared pulses

Abstract: We report on the coherent detection of ultra-broadband mid-infrared electromagnetic pulses using a 30-μm-thick ZnTe electro-optic sensor. The detected frequency spectrum exceeds 37 THz, extending from microwave to the mid-infrared. The frequency response can be further improved by reducing the sensor thickness to 10 μm.

Effect of aggregation on thermal conduction in colloidal nanofluids

Abstract: Using effective medium theory the authors demonstrate that the thermal conductivity of nanofluids can be significantly enhanced by the aggregation of nanoparticles into clusters. Predictions of the effective medium theory are in excellent agreement with detailed numerical calculation on model nanofluids involving fractal clusters and show the importance of cluster morphology on thermal conductivity enhancements.

Concepts for design of FACTS controllers to damp power swings

Abstract: The design of controllers sited in the transmission network for damping interarea power oscillations requires several types of analytical tools and field verification methods. Probably the most important aspect of such control design is the selection of proper feedback measurements from the network. This paper describes concepts which provide design engineers with the insight to control performance and the understanding needed to ensure the secure operation of the bulk transmission system. Specific attention is directed to procedures for selecting feedback signals. >