3,378 research outputs found
An Interdisciplinary Undergraduate Degree Program in Electronic Commerce
This paper describes an innovative curriculum for an interdisciplinary undergraduate degree program in electronic commerce. Faculty from the disciplines of computer information systems, computer science, operations management, marketing and graphic design collaborated in devising a curriculum that focuses on the business of electronic commerce while providing a solid base of information technology skills. The program includes an integrated junior year experience that gives students business and technical skills in a team-taught environment. During the senior year, students concentrate on technology infrastructure, business processes, or market analysis and development. This paper not only presents a blueprint for an undergraduate curriculum, but also provides a model for faculty cooperation across academic disciplines
Invited Article: Data Analysis of the Floating Potential Measurement Unit Aboard the International Space Station
We present data from the Floating Potential Measurement Unit (FPMU) that is deployed on the starboard truss of the International Space Station. The FPMU is a suite of instruments capable of redundant measurements of various plasma parameters. The instrument suite consists of a floating potential probe, a wide-sweeping spherical Langmuir probe, a narrow-sweeping cylindrical Langmuir probe, and a plasma impedance probe. This paper gives a brief overview of the instrumentation and the received data quality, and then presents the algorithm used to reduce I-V curves to plasma parameters. Several hours of data are presented from August 5, 2006 and March 3, 2007. The FPMU derived plasma density and temperatures are compared with the International Reference Ionosphere (IRI) and Utah State University-Global Assimilation of Ionospheric Measurement (USU-GAIM) models. Our results show that the derived in situ density matches the USU-GAIM model better than the IRI, and the derived in situ temperatures are comparable to the average temperatures given by the IRI
Data Analysis of the Floating Potential Measurement Unit aboard the International Space Station
We present data from the Floating Potential Measurement Unit (FPMU), that is deployed on the starboard (S1) truss of the International Space Station. The FPMU is a suite of instruments capable of redundant measurements of various plasma parameters. The instrument suite consists of: a Floating Potential Probe, a Wide-sweeping spherical Langmuir probe, a Narrow-sweeping cylindrical Langmuir Probe, and a Plasma Impedance Probe. This paper gives a brief overview of the instrumentation and the received data quality, and then presents the algorithm used to reduce I-V curves to plasma parameters. Several hours of data is presented from August 5th, 2006 and March 3rd, 2007. The FPMU derived plasma density and temperatures are compared with the International Reference Ionosphere (IRI) and USU-Global Assimilation of Ionospheric Measurement (USU-GAIM) models. Our results show that the derived in-situ density matches the USU-GAIM model better than the IRI, and the derived in-situ temperatures are comparable to the average temperatures given by the IRI
A Theory for Rapid Charging Events on the International Space Station
The Floating Potential Measurement Unit (FPMU) has detected high negative amplitude rapid charging events (RCEs) on the International Space Station (ISS) at the morning terminator. These events are larger and more rapid than the ISS morning charging events first seen by the Floating Potential Probe (FPP) on ISS in 2001. In this paper, we describe a theory for the RCEs that further elucidates the nature of spacecraft charging in low Earth orbit (LEO) in a non-equilibrium situation. The model accounts for all essential aspects of the newly discovered phenomenon, and is amenable to testing on-orbit. Predictions of the model for the amplitude of the ISS RCEs for the full set of ISS solar arrays and for the coming solar cycle are given, and the results of modeling by the Environments WorkBench (EWB) are compared to the observed events to show that the phenomenon can be explained by solar array driven charging. The situation is unique because the coverglasses have not yet reached equilibrium with the surrounding plasma during the RCEs. Finally, a prescription for further use of the ISS for investigating fundamental plasma physics in LEO is given. Already, plasma and charging monitoring instruments on ISS have taught us much about spacecraft interactions with the dense LEO plasma, and we expect they will continue to yield more valuable science when the Japanese Experiment Module (JEM) is in place
Recommended from our members
Miocene stable isotopic stratigraphy and magnetostratigraphy of Buff Bay, Jamaica
Previously reported biostratigraphic relationships from middle-upper Miocene sections exposed near Buff Bay, Jamaica (18°N, tropical bioprovince), differ from the subtropical North Atlantic (Sites 563 and 558). Time scales for this interval rely on correlations established at these subtropical sites, and the differences with the tropical section have implications to global correlations. Planktonic foraminiferal Zones N13 and N15 are thick at Buff Bay but are virtually absent at Sites 563 and 558; nannofossil Zone NN9 is associated with Zone N15 and uppermost Zone N14 at Buff Bay but is associated with Zone N16 at the other sites. Magnetostratigraphic data presented here further complicate the interpretation: Zone NN9 is associated with a thick normal magnetozone at Sites 563 and 558; at Buff Bay, it is associated with a thick reversed magnetozone. Although a secondary magnetization at Buff Bay makes it difficult to identify confidently Miocene normal magnetozones, the thick reversed magnetozone most likely represents the paleomagnetic field and correlates with Chron C5r. The magnetobiostratigraphic relationships require either diachrony of taxa or two mutually exclusive hiatuses in Jamaica and the North Atlantic. We address this problem by analyzing benthic foraminiferal δ^18O and δ^13C from the Buff Bay section. These isotopic data allow us to evaluate three hypotheses that reconcile the magneto-, bio-, and isotopic stratigraphic data and conclude that the first and last occurrences of five taxa were diachronous by ~0.3-0.5 m.y. between tropical and subtropical locations. This requires revised age estimates for late middle to early late Miocene biostratigraphic datum levels. We suggest that the ranges of several taxa are useful for endemic tropical or subtropical zonations, but correlations between the low and midlatitudes were affected by an increase in latitudinal thermal gradients during the late middle Miocene. However, we admit that further studies are needed before this issue is resolved
Hubble Space Telescope Spectroscopy of Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer
We present a sample of brown dwarfs identified with the {\it Wide-field
Infrared Survey Explorer} (WISE) for which we have obtained {\it Hubble Space
Telescope} ({\it HST}) Wide Field Camera 3 (WFC3) near-infrared grism
spectroscopy. The sample (twenty-two in total) was observed with the G141 grism
covering 1.101.70 m, while fifteen were also observed with the G102
grism, which covers 0.901.10 m. The additional wavelength coverage
provided by the G102 grism allows us to 1) search for spectroscopic features
predicted to emerge at low effective temperatures (e.g.\ ammonia bands) and 2)
construct a smooth spectral sequence across the T/Y boundary. We find no
evidence of absorption due to ammonia in the G102 spectra. Six of these brown
dwarfs are new discoveries, three of which are found to have spectral types of
T8 or T9. The remaining three, WISE J082507.35280548.5 (Y0.5), WISE
J120604.38840110.6 (Y0), and WISE J235402.77024015.0 (Y1) are the
nineteenth, twentieth, and twenty-first spectroscopically confirmed Y dwarfs to
date. We also present {\it HST} grism spectroscopy and reevaluate the spectral
types of five brown dwarfs for which spectral types have been determined
previously using other instruments.Comment: Accepted for publication in the Astrophysical Journal. 20 pages, 18
figures, 7 table
Effects of Novel Chalcone Derivatives upon H9c2 and MDCK Cell Viability
Many compounds with potential anti-cancer activity fail to reach the latter stages of clinical trials due to adverse effects, often causing cardiac and renal toxicity. Here, we synthesised a group of
novel chalcone compounds, thought to have potential anti-cancer activity4 and assessed their effects upon cardiac and renal cell viability. Data revealed that all compounds produced minimal
short term toxicity. Further work will be performed to assess the long term effects of these compounds on cell viability, leading to mechanistic studies and structure activity relationship analyses
WISE Brown Dwarf Binaries: The Discovery of a T5+T5 and a T8.5+T9 System
The multiplicity properties of brown dwarfs are critical empirical constraints for formation theories, while multiples themselves provide unique opportunities to test evolutionary and atmospheric models and examine empirical trends. Studies using high-resolution imaging cannot only uncover faint companions, but they can also be used to determine dynamical masses through long-term monitoring of binary systems. We have begun a search for the coolest brown dwarfs using preliminary processing of data from the Wide-field Infrared Survey Explorer and have confirmed many of the candidates as late-type T dwarfs. In order to search for companions to these objects, we are conducting observations using the Laser Guide Star Adaptive Optics system on Keck II. Here we present the first results of that search, including a T5 binary with nearly equal mass components and a faint companion to a T8.5 dwarf with an estimated spectral type of T9
- …