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Selected Works

2008

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Articles 31 - 60 of 913

Full-Text Articles in Physical Sciences and Mathematics

Adhesion And Interfacial Fracture Toughness Between Hard And Soft Materials, Nima Rahbar, Kurt Wolf, Argjenta Orana, Roy Fennimore, Zong Zong, Juan Meng, George Papandreou, Cynthia Maryanoff, Wole Soboyejo Nov 2008

Adhesion And Interfacial Fracture Toughness Between Hard And Soft Materials, Nima Rahbar, Kurt Wolf, Argjenta Orana, Roy Fennimore, Zong Zong, Juan Meng, George Papandreou, Cynthia Maryanoff, Wole Soboyejo

Nima Rahbar

This paper presents the results of a combined experimental and theoretical study of adhesion between hard and soft layers that are relevant to medical devices such as drug-eluting stents and semiconductor applications. Brazil disk specimens were used to measure the interfacial fracture energies between model parylene C and 316L stainless steel over a wide range of mode mixities. The trends in the overall fracture energies are predicted using a combination of adhesion theories and fracture mechanics concepts. The measured interfacial fracture energies are shown to be in good agreement with the predictions.


Tidal Heating Of Terrestrial Extrasolar Planets And Implications For Their Habitability, Brian Jackson, Rory Barnes, Richard Greenberg Nov 2008

Tidal Heating Of Terrestrial Extrasolar Planets And Implications For Their Habitability, Brian Jackson, Rory Barnes, Richard Greenberg

Brian Jackson

The tidal heating of hypothetical rocky (or terrestrial) extrasolar planets spans a wide range of values depending on stellar masses and initial orbits. Tidal heating may be sufficiently large (in many cases, in excess of radiogenic heating) and long-lived to drive plate tectonics, similar to the Earth's, which may enhance the planet's habitability. In other cases, excessive tidal heating may result in Io-like planets with violent volcanism, probably rendering them unsuitable for life. On water-rich planets, tidal heating may generate subsurface oceans analogous to Europa's with similar prospects for habitability. Tidal heating may enhance the outgassing of volatiles, contributing to …


Finding Recurrent Regions Of Copy Number Variation: A Review, Oscar M. Rueda, Ramon Diaz-Uriarte Nov 2008

Finding Recurrent Regions Of Copy Number Variation: A Review, Oscar M. Rueda, Ramon Diaz-Uriarte

Ramon Diaz-Uriarte

Copy number alterations (CNA) in genomic DNA are linked to a variety of human diseases. Although many methods have been developed to analyze data from a single subject, disease-critical genes are more likely to be found in regions that are common or recurrent among diseased subjects. Unfortunately, finding recurrent CNA regions remains a challenge. We review existing methods for the identification of recurrent CNA regions. Methods differ in their working definition of ``recurrent region'', the type of input data, the statistical and computational methods used to identify recurrence, and the biological considerations they incorporate (which play a role in the …


Potential Driven Deposition Of Poly(Diallyldimethylammonium Chloride) Onto The Surface Of 3-Mercaptopropionic Acid Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson Nov 2008

Potential Driven Deposition Of Poly(Diallyldimethylammonium Chloride) Onto The Surface Of 3-Mercaptopropionic Acid Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson

Mark R. Anderson

Electrochemical impedance spectroscopy (EIS) and quartz crystal microbalance (QCM) measurements are used to examine the ability of applied potential to drive the ionic self-assembly of poly(diallyldimethylammonium) chloride (PDDA) onto a substrate modified with a monolayer of 3-mercaptopropionic acid (3-MPA). The potential of zero charge (PZC) of the gold electrode modified with a monolayer of 3-MPA was found by differential capacitance measurements to be −0.12 (±0.01) V versus Ag−AgCl. Changing the substrate potential to values positive (−0.01 V vs Ag−AgCl) of the PZC induces interfacial conditions that are favorable for the electrostatic deposition of cationic polymers onto the surface of 3-MPA …


The Role Of Science And Engineering In Water Regulation Over The Past 100 Years, James R. May, Patrick Clary Nov 2008

The Role Of Science And Engineering In Water Regulation Over The Past 100 Years, James R. May, Patrick Clary

James R. May

This article explores how scientific and engineering principles are inexorably linked to the regulation of water. Scientists and engineers first discovered the link between disease and water sources in the mid-19th century. Over the years, scientists and engineers have led the way to identifying water quality problems and their causes. These discoveries have directly contributed to the scope of water regulation in the United States and elsewhere. In addition, changes in water quality regulation have dictated the need for increasingly sophisticated water treatment technologies and engineers have been at the forefront of the development of these water control technologies. This …


Regressing Scalar Outcomes On Image Predictors Via Functional Principal Component Regression, Philip T. Reiss Nov 2008

Regressing Scalar Outcomes On Image Predictors Via Functional Principal Component Regression, Philip T. Reiss

Philip T. Reiss

No abstract provided.


Networking, William Osei-Poku Nov 2008

Networking, William Osei-Poku

William Osei-Poku

No abstract provided.


Player Guild Dynamics And Evolution In Massively Multiplayer Online Games, Chien Hsun Chen, J. L. Hsieh, C. T. Sun Nov 2008

Player Guild Dynamics And Evolution In Massively Multiplayer Online Games, Chien Hsun Chen, J. L. Hsieh, C. T. Sun

Chien Hsun Chen

In the latest versions of massively multiplayer online games (MMOGs), developers have purposefully made guilds part of game environments. Guilds represent a powerful method for giving players a sense of online community, but there is little quantitative data on guild dynamics. To address this topic, we took advantage of a feature found in one of today’s most popular MMOGs (World of Warcraft) to collect in-game data: user interfaces that players can modify and refine. In addition to collecting data on in-game player activities, we used this feature to observe and investigate how players join and leave guilds. Data were analyzed …


Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr Nov 2008

Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr

Dr Deogratias Harorimana

This chapter introduces the role of the knowledge gatekeeper as a mechanism by which knowledge is created and transferred in a networked environment. Knowledge creation and transfer are essential for building a knowledge based economy. The chapter considers obstacles that inhibit this process and argues that leading firms create a shared socio-cultural context that enables the condivision of tacit meanings and codification of knowledge. Leading firms act as gatekeepers of knowledge through the creation of shared virtual platforms. There will be a leading firm that connects several networks of clients and suppliers may not interact directly with one another, but …


Survival Unchanged Five Months After Implementing The 2005 Aha Cpr And Ecc Guidelines For Out-Of-Hospital Cardiac Arrest., Blair L. Bigham, Kent M. Koprowicz, John Stouffer, Tom P. Aufderheide, Stuart Donn, Judy Powell, Dan Davis, Sarah Nafziger, Brian Suffoletto, Ahamed Idris, Mike Helbock, Laurie J. Morrison Nov 2008

Survival Unchanged Five Months After Implementing The 2005 Aha Cpr And Ecc Guidelines For Out-Of-Hospital Cardiac Arrest., Blair L. Bigham, Kent M. Koprowicz, John Stouffer, Tom P. Aufderheide, Stuart Donn, Judy Powell, Dan Davis, Sarah Nafziger, Brian Suffoletto, Ahamed Idris, Mike Helbock, Laurie J. Morrison

Kent M Koprowicz

Introduction: To improve survival from out of hospital cardiac arrest (OHCA), the American Heart Association released guidelines in 2005. We examined the effect of these guidelines on survival in the Resuscitation Outcomes Consortium (ROC) Epistry – Cardiac Arrest. We hypothesized that survival would increase after guideline implementation. Methods: 174 EMS agencies from 8 of the 10 ROC sites were surveyed to determine 2005 AHA guideline implementation, or crossover, date. Two sites with 2005 compatible treatment algorithms prior to guideline release were not included. Patients with OHCA secondary to a non cardiac cause, EMS witnessed events, patients <18 years>old, and patients with …


Una Comparazione Tra Le Reti Di Amministratori Nelle Principali Societa Quotate In Italia, Francia E Gran Bretagna, Paolo Santella, Carlo Drago, Andrea Polo, Enrico Gagliardi Nov 2008

Una Comparazione Tra Le Reti Di Amministratori Nelle Principali Societa Quotate In Italia, Francia E Gran Bretagna, Paolo Santella, Carlo Drago, Andrea Polo, Enrico Gagliardi

Carlo Drago

The purpose of the present paper is to contribute to the empirical literature on country interlocks by illustrating and analysing the interlocking directorships in the first 40 Italian, French and British Blue Chips as of December 2007 (Italy)/March 2008 (France and uk). The theoretical literature identify two possible explanations for interlocking directorships, on the one hand the collusion among players in the same market or in general among enterprises that have business relations among themselves; on the other hand the interest for enterprises to have on their boards bankers, suppliers, and clients so as to reduce information asymmetries. Our findings …


Book Ii, Otto Vogl: Papers And Patents, 1970-1977, Jane C. Vogl Nov 2008

Book Ii, Otto Vogl: Papers And Patents, 1970-1977, Jane C. Vogl

Otto Vogl

Books I-XII include citations to Otto Vogl's publications and patents. Printed versions of these twelve volumes are also available in the Integrated Sciences and Engineering Library of the University of Massachusetts in Amherst. MA, Lederle Graduate Research Center. The printed volumes include the full reprints of all cited publications.


Asymptotic Behavior Of Linearized Viscoelastic Flow Problem, Yinnian He, Yi Li Nov 2008

Asymptotic Behavior Of Linearized Viscoelastic Flow Problem, Yinnian He, Yi Li

Yi Li

In this article, we provide some asymptotic behaviors of linearized viscoelastic flows in a general two-dimensional domain with certain parameters small and the time variable large.


Material Damage From Ultrashort Bursts Of Light, Jeremy Gulley Oct 2008

Material Damage From Ultrashort Bursts Of Light, Jeremy Gulley

Jeremy R. Gulley

No abstract is currently available.


All-Optical Suppression Of Relativistic Self-Focusing Of Laser Beams In Plasmas, Serguei Y. Kalmykov, Sunghwan A. Yi, Gennady Shvets Oct 2008

All-Optical Suppression Of Relativistic Self-Focusing Of Laser Beams In Plasmas, Serguei Y. Kalmykov, Sunghwan A. Yi, Gennady Shvets

Serge Youri Kalmykov

It is demonstrated that a catastrophic relativistic self-focusing (RSF) of a high-power laser pulse can be prevented all-optically by a second, much weaker, copropagating pulse. RSF suppression occurs when the difference frequency of the pulses slightly exceeds the electron plasma frequency. The mutual defocusing is caused by the three-dimensional electron density perturbation driven by the laser beat wave slightly above the plasma resonance. A bi-envelope model describing the early stage of the mutual defocusing is derived and analyzed. Later stages, characterized by the presence of a strong electromagnetic cascade, are investigated numerically. Stable propagation of the laser pulse with weakly …


Magnetic Field Measurements Of O Stars With Fors 1 At The Vlt., S. Hubrig, M. Schöller, R. S. Schnerr, J. F. González, R. Ignace, H. F. Henrichs Oct 2008

Magnetic Field Measurements Of O Stars With Fors 1 At The Vlt., S. Hubrig, M. Schöller, R. S. Schnerr, J. F. González, R. Ignace, H. F. Henrichs

Richard Ignace

Context.The presence of magnetic fields in O-type stars has been suspected for a long time. The discovery of these fields would explain a wide range of well documented enigmatic phenomena in massive stars, in particular cyclical wind variability, Hα emission variations, chemical peculiarity, narrow X-ray emission lines, and non-thermal radio/X-ray emission.
Aims.To investigate the incidence of magnetic fields in O stars, we acquired 38 new spectropolarimetric observations with FORS 1 (FOcal Reducer low dispersion Spectrograph) mounted on the 8-m Kueyen telescope of the VLT.
Methods.Spectropolarimetric observations were obtained at different phases for a sample of 13 O …


Efficient Gene Delivery Vectors By Tuning The Surface Charge Density Of Amino Acid-Functionalized Gold Nanoparticles, Ps Ghosh, Ck Kim, G Han, Ns Forbes, Vm Rotello Oct 2008

Efficient Gene Delivery Vectors By Tuning The Surface Charge Density Of Amino Acid-Functionalized Gold Nanoparticles, Ps Ghosh, Ck Kim, G Han, Ns Forbes, Vm Rotello

Vincent Rotello

Gold colloids functionalized with amino acids provide a scaffold for effective DNA binding with subsequent condensation. Particles with lysine and lysine dendron functionality formed particularly compact complexes and provided highly efficient gene delivery without any observed cytotoxicity. Nanoparticles functionalized with first generation lysine dendrons (NP-LysG1) were approximately 28-fold superior to polylysine in reporter gene expression. These amino acid-based nanoparticles were responsive to intracellular glutathione levels, providing a tool for controlled release and concomitant expression of DNA.


Sequence Specific And High Affinity Recognition Of 5′-Acgcgt-3′ By Rationally Designed Pyrrole-Imidazole H-Pin Polyamides: Thermodynamic And Structural Studies., Hilary Mackay, Toni Brown, Peter Uthe, Laura Westrate, Alan Sielaff, Justin Jones, James Lajiness, Jerome Kluza, Caroline O'Hare, Binh Nguyen, Zach Davis, Chrystal Bruce, W. Wilson, John Hartley, Moses Lee Oct 2008

Sequence Specific And High Affinity Recognition Of 5′-Acgcgt-3′ By Rationally Designed Pyrrole-Imidazole H-Pin Polyamides: Thermodynamic And Structural Studies., Hilary Mackay, Toni Brown, Peter Uthe, Laura Westrate, Alan Sielaff, Justin Jones, James Lajiness, Jerome Kluza, Caroline O'Hare, Binh Nguyen, Zach Davis, Chrystal Bruce, W. Wilson, John Hartley, Moses Lee

Chrystal D. Bruce

Imidazole (Im) and Pyrrole (Py)-containing polyamides that can form stacked dimers can be programmed to target specific sequences in the minor groove of DNA and control gene expression. Even though various designs of polyamides have been thoroughly investigated for DNA sequence recognition, the use of H-pin polyamides (covalently cross-linked polyamides) has not received as much attention. Therefore, experiments were designed to systematically investigate the DNA recognition properties of two symmetrical H-pin polyamides composed of PyImPyIm (5) or f-ImPyIm (3e, f=formamido) tethered with an ethylene glycol linker. These compounds were created to recognize the cognate 5′-ACGCGT-3′ through an overlapped and staggered …


Impedance Of Contact-Printed Alkanethiol Self-Assembled Monolayers On Gold, Leslie Adamczyk, Mark Anderson Oct 2008

Impedance Of Contact-Printed Alkanethiol Self-Assembled Monolayers On Gold, Leslie Adamczyk, Mark Anderson

Mark R. Anderson

Contact printing (CP) is a common method for creating modified interfaces having two-dimensional patterns. The popularity of this method is due to the ease and low cost of this method. When printing an interfacial pattern with n-alkanethiols, the desired properties are those of a homogeneous, solution deposited monolayer. Patterning a surface, however, may cause defects to occur within the monolayer where two thiol domains meet. If large enough, the activity of these areas can dominate the electrochemical response. Creating patterned monolayer modified interfaces, therefore, may generate vast user defined domain boundaries that impact the electrochemical behavior of the modified interface …


Potential Driven Polyelectrolyte Adsorption Onto Monolayer Modified Electrodes, Mark Anderson, Weslie Sanders Oct 2008

Potential Driven Polyelectrolyte Adsorption Onto Monolayer Modified Electrodes, Mark Anderson, Weslie Sanders

Mark R. Anderson

Preparation of interfacial structures by molecular self-assembly has been actively studied for many years. Well-defined modified interfaces can be used to study fundamental interfacial properties, or they can be used in different practical applications. To broaden the utility of interfaces prepared by molecular self-assembly, monolayers containing terminal functionality are frequently used. These interfaces have structural and physical properties that can be controlled by both the identity of the functionalization as well as the ensemble structure of the modified interface. This suggests that the chemical and physical properties of an interface can be designed and/or controlled to some extent by altering …


Homogeneous Dbd In N2: 1) Lif, Talif And Electrical Measurements, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines Oct 2008

Homogeneous Dbd In N2: 1) Lif, Talif And Electrical Measurements, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines

Dr. Et-touhami Es-sebbar

In this paper we compare two different discharges that can be obtained in a DBD configuration, that is to say the filamentary discharge (usual regime in atmospheric DBD) with the Atmospheric Pressure Townsend Discharge (APTD), which is a homogeneous regime obtained in nitrogen atmosphere. The aim is to help in the understanding of the processes which control the transition from one regime to the other. To do so, the discharge is characterized through electrical measurements, coupled with optical diagnostics among which Laser Induced Fluorescence (LIF) for radical density measurements. The influence of the addition of small quantities of additives on …


Argus: A New Frontiers Mission Proposal To Observe Io, Ryan C. Fortenberry Oct 2008

Argus: A New Frontiers Mission Proposal To Observe Io, Ryan C. Fortenberry

Ryan C. Fortenberry

The Argus mission will obtain breakthrough level science advances by investigating Jupiter's innermost Galilean moon Io as outlined in the 2008 National Academies Report on choices for the next New Frontiers Announcement of Opportunity. Io has the greatest amount of volcanic activity of any planetary body in the solar system and provides a great location for studying this fundamental planetary process. The surface of Io is rich in sulfur and sulfur dioxide frost however is not as icy as other moons of the outer planets. The orbit of Io has a 2:1 orbital resonance with Jupiter's next Galilean moon Europa …


666 Or 616 (Rev. 13,18), M. G. Michael Oct 2008

666 Or 616 (Rev. 13,18), M. G. Michael

M. G. Michael

No abstract provided.


The Genre Of The Apocalypse: What Are They Saying Now?, M. G. Michael Oct 2008

The Genre Of The Apocalypse: What Are They Saying Now?, M. G. Michael

M. G. Michael

No abstract provided.


Synthesis Of Large Crystal Transition Metal Substituted Zeolite Zsm-5, Tara L. Schaeffer, Scott Kirkby Oct 2008

Synthesis Of Large Crystal Transition Metal Substituted Zeolite Zsm-5, Tara L. Schaeffer, Scott Kirkby

Scott J. Kirkby

 Crystals of ZSM-5 containing Cu, Mn, and Fe have been synthesized up to 85 μm in length along the long axis.
This is 1 to 2 orders of magnitude larger than any previously reported. Phase identification was accomplished by powder XRD. A modified Charnel’s method was used to chelate the transition metal and the aluminum in the synthesis gel. Element alanalysis was performed by ICP-AES, confirming the presence of the metals. The metals are resistant to leaching under ion exchange and, as determined by partial dissolution, incorporated throughout the volume of the crystals. 


Comparative Genomics Of Geobacter Chemotaxis Genes Reveals Diverse Signaling Function, Hoa T. Tran, Julia Krushkal, Frances M. Antommattei, Derek R. Lovley, Robert Weis Oct 2008

Comparative Genomics Of Geobacter Chemotaxis Genes Reveals Diverse Signaling Function, Hoa T. Tran, Julia Krushkal, Frances M. Antommattei, Derek R. Lovley, Robert Weis

Robert Weis

Background Geobacter species are δ-Proteobacteria and are often the predominant species in a variety of sedimentary environments where Fe(III) reduction is important. Their ability to remediate contaminated environments and produce electricity makes them attractive for further study. Cell motility, biofilm formation, and type IV pili all appear important for the growth of Geobacter in changing environments and for electricity production. Recent studies in other bacteria have demonstrated that signaling pathways homologous to the paradigm established for Escherichia coli chemotaxis can regulate type IV pili-dependent motility, the synthesis of flagella and type IV pili, the production of extracellular matrix material, and …


Potential Driven Polyelectrolyte Adsorptoin Onto Monolayer Modified Electrodes, Mark Anderson Oct 2008

Potential Driven Polyelectrolyte Adsorptoin Onto Monolayer Modified Electrodes, Mark Anderson

Mark R. Anderson

No abstract currently available.


Spectra Of Nearby Galaxies Measured With A New Very Broadband Receiver, Gopal Narayanan, Ronald L. Snell, Neal A. Erickson, Aeree Chung, Mark H. Heyer, Min Yun, William M. Irvine Oct 2008

Spectra Of Nearby Galaxies Measured With A New Very Broadband Receiver, Gopal Narayanan, Ronald L. Snell, Neal A. Erickson, Aeree Chung, Mark H. Heyer, Min Yun, William M. Irvine

William M. Irvine

Three-millimeter-wavelength spectra of a number of nearby galaxies have been obtained at the Five College Radio Astronomy Observatory (FCRAO) using a new, very broadband receiver. This instrument, which we call the Redshift Search Receiver, has an instantaneous bandwidth of 36 GHz and operates from 74 to 110.5 GHz. The receiver has been built at UMass/FCRAO to be part of the initial instrumentation for the Large Millimeter Telescope (LMT) and is intended primarily for determination of the redshift of distant, dust-obscured galaxies. It is being tested on the FCRAO 14 m by measuring the 3 mm spectra of a number of …


Nanoplasmonic Renormalization And Enhancement Of Coulomb Interactions, Maxim Durach, Anastasia Rusina, V. I. Kilmov, Mark I. Stockman Oct 2008

Nanoplasmonic Renormalization And Enhancement Of Coulomb Interactions, Maxim Durach, Anastasia Rusina, V. I. Kilmov, Mark I. Stockman

Anastasia Rusina

In this paper, we propose a general and powerful theory of the plasmonic enhancement of the many-body phenomena resulting in a closed expression for the surface plasmon-dressed Coulomb interaction. We illustrate this theory by computing the dressed interaction explicitly for an important example of metal–dielectric nanoshells which exhibits a rich resonant behavior in magnitude and phase. This interaction is used to describe the nanoplasmonic-enhanced Förster resonant energy transfer (FRET) between nanocrystal quantum dots near a nanoshell.


Ocena Wpływu Arcelormittal Poland S.A. Oddział W Krakowie Na Jakość Powietrza, Marian Mazur, Robert Oleniacz, Marek Bogacki, Przemysław Szczygłowski Oct 2008

Ocena Wpływu Arcelormittal Poland S.A. Oddział W Krakowie Na Jakość Powietrza, Marian Mazur, Robert Oleniacz, Marek Bogacki, Przemysław Szczygłowski

Robert Oleniacz

The work presents selected results of atmospheric dispersion modeling and air quality impact assessment for pollutant emissions from installations of ArcelorMittal Poland S.A. Unit in Krakow (Poland). The assessment was carried out for the most unfavourable emission variant probable to take place in the period 2007-2016. In the calculations were taken into consideration typical for steelworks particle matter pollutants (total dust, heavy metals, tar substances and PAHs including benzo-a-piren) and gaseous substances (SO2, NO2, CO, HC, HCl, HF, NH3, HCN, H2S, CS2, H2SO4, BTX, phenol and pyridine). As the result of estimations, carried out according to the Polish reference method …