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.

Upon Opening the Black Box and Finding It Empty: Social Constructivism and the Philosophy of Technology:

Abstract: What do philosophers need to know about technology? What kind of knowledge do we need to have? And how much? Perhaps it is enough simply to have lived in a society in which a wide variety of technologies are in common use. Drawing upon an everyday understanding of such matters, one can move on to develop general perspectives and theories that may enable us to answer important questions about technology in general. The problem is that one's grasp may be superficial, failing to do justice to the phenomena one wants to explain and interpret. One may seize upon a limited range of vaguely understood examples of technical applications-a dam on a river, a robot in a factory, or some other typification-and try to wring universal implications from a sample that is perhaps too small to carry the weight placed upon it. An alternative would be to focus one's attention more carefully, becoming expert in the technical knowledge of a specific field, attaining the deeper understanding of, say, a worker, engineer, or technical professional. Even that may prove limiting, however, because the experience available in one field of practice may not be useful in comprehending the origins, character, and consequences of technical practices in other domains. The sheer multiplicity of technologies in modern society poses serious difficulties for anyone who seeks an overarching grasp of human experience in a technological society. Yet another strategy might be to study particular varieties of technology in a scholarly mode, drawing upon existing histories and contemporary social studies of technological change as one's base of understanding. And one

Defect engineering of two-dimensional transition metal dichalcogenides

Abstract: Two-dimensional transition metal dichalcogenides (TMDs), an emerging family of layered materials, have provided researchers a fertile ground for harvesting fundamental science and emergent applications. TMDs can contain a number of different structural defects in their crystal lattices which significantly alter their physico-chemical properties. Having structural defects can be either detrimental or beneficial, depending on the targeted application. Therefore, a comprehensive understanding of structural defects is required. Here we review different defects in semiconducting TMDs by summarizing: (i) the dimensionalities and atomic structures of defects; (ii) the pathways to generating structural defects during and after synthesis and, (iii) the effects of having defects on the physico-chemical properties and applications of TMDs. Thus far, significant progress has been made, although we are probably still witnessing the tip of the iceberg. A better understanding and control of defects is important in order to move forward the field of Defect Engineering in TMDs. Finally, we also provide our perspective on the challenges and opportunities in this emerging field.

The Milky Way’s Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from the Kinematics of ~2400 SDSS Blue Horizontal-Branch Stars

Abstract: We derive new constraints on the mass of the Milky Way's dark matter halo, based on 2401 rigorously selected blue horizontal-branch halo stars from SDSS DR6. This sample enables construction of the full line-of-sight velocity distribution at different galactocentric radii. To interpret these distributions, we compare them to matched mock observations drawn from two different cosmological galaxy formation simulations designed to resemble the Milky Way. This procedure results in an estimate of the Milky Way's circular velocity curve to ~60 kpc, which is found to be slightly falling from the adopted value of 220 km s?1 at the Sun's location, and implies -->M( Vcir(r) , derived in statistically independent bins, is found to be consistent with the expectations from an NFW dark matter halo with the established stellar mass components at its center. If we assume that an NFW halo profile of characteristic concentration holds, we can use the observations to estimate the virial mass of the Milky Way's dark matter halo, -->Mvir = 1.0+ 0.3?0.2 ? 1012 M?, which is lower than many previous estimates. We have checked that the particulars of the cosmological simulations are unlikely to introduce systematics larger than the statistical uncertainties. This estimate implies that nearly 40% of the baryons within the virial radius of the Milky Way's dark matter halo reside in the stellar components of our Galaxy. A value for -->Mvir of only ~ -->1 ? 1012 M? also (re)opens the question of whether all of the Milky Way's satellite galaxies are on bound orbits.

Entrepreneurs' Optimism And New Venture Performance: A Social Cognitive Perspective

Abstract: Previous research indicates that entrepreneurs are generally high in dispositional optimism—the tendency to expect positive outcomes even when such expectations are not rationally justified. Findings of the current study demonstrate a negative relationship between entrepreneurs' optimism and the performance (revenue and employment growth) of their new ventures. Past experience creating ventures and industry dynamism moderated these effects, strengthening the negative relationship between entrepreneurs' optimism and venture performance. These findings illustrate the benefits of applying a social cognitive perspective toward efforts to understand key aspects of the new venture creation and development process.