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Negative Conductance Power Amplifier, Vladimir I. Prodanov 2010 Agere Systems, Allentown, NJ

Negative Conductance Power Amplifier, Vladimir I. Prodanov

Vladimir I. Prodanov

Power amplifiers are disclosed that demonstrate improved linearity and efficiency in applications requiring significant peak-to-average ratios (PAR). A power amplifier in accordance with the present invention comprises a first transistor in an input stage that converts DC power into AC power; and a second transistor in a negative conductance stage that has a current-voltage characteristic with at least two slopes. The at least two slopes of the current-voltage characteristic are separated by a break point that may be controlled. The power amplifier may also include a non-dissipative two-port device that has two AC ports. The non-dissipative two-port device has a ...


A 32-Mw 320-Mhz Continuous-Time Complex Delta-Sigma Adc For Multi-Mode Wireless-Lan Receivers, Jesus Arias, Peter Kiss, Vladimir Prodanov, Vito Boccuzzi, Mihai Banu, David Bisbal, Jacinto San Pablo, Luis Quintanilla, Juan Barbolla 2010 Universidad de Valladolid

A 32-Mw 320-Mhz Continuous-Time Complex Delta-Sigma Adc For Multi-Mode Wireless-Lan Receivers, Jesus Arias, Peter Kiss, Vladimir Prodanov, Vito Boccuzzi, Mihai Banu, David Bisbal, Jacinto San Pablo, Luis Quintanilla, Juan Barbolla

Vladimir I. Prodanov

We present an experimental continuous-time complex delta-sigma multi-bit modulator, implemented in standard 0.25-μm CMOS technology and meeting all major requirements for application in IEEE 802.11a/b/g wireless LAN receivers. The clock frequency is 320 MHz, producing an oversampling ratio of 16 for 20 MHz channel bandwidths. The modulator supports two operation modes for zero-IF and low-IF receiver architectures respectively, requires a single 2.5-V power supply, and dissipates only 32 mW of power. The measured peak signal-to-noise ratio is 55 dB. Further experimental results using sine-wave and OFDM test signals are also presented


Sustainability And Water At The University Of Iowa Facilities Management, Liz Christiansen 2010 University of Iowa

Sustainability And Water At The University Of Iowa Facilities Management, Liz Christiansen

Water Sustainability Initiative Publications

No abstract provided.


Water Sustainability Initiative, Jerry Schnoor 2010 University of Iowa

Water Sustainability Initiative, Jerry Schnoor

Water Sustainability Initiative Publications

No abstract provided.


Water Resource Sustainability: Our Shared Responsibility, Nandita Basu 2010 University of Iowa

Water Resource Sustainability: Our Shared Responsibility, Nandita Basu

Water Sustainability Initiative Publications

No abstract provided.


A Microflow Cytometer On A Chip, Joel P. Golden, Jason Kim, George P. Anderson, Nicole N. Hashemi, Peter J. Howell, Frances S. Ligler 2010 Selected Works

A Microflow Cytometer On A Chip, Joel P. Golden, Jason Kim, George P. Anderson, Nicole N. Hashemi, Peter J. Howell, Frances S. Ligler

Nicole N. Hashemi

A rapid, automated, multi-analyte Microflow Cytometer is being developed as a portable, field-deployable sensor for onsite diagnosis of biothreat agent exposure and environmental monitoring. The technology relies on a unique method for ensheathing a sample stream in continuous flow past an interrogation region where optical fibers provide excitation and collect emission. This approach efficiently focuses particles in the interrogation region of the fluidic channel, avoids clogging and provides for subsequent separation of the core and sheath fluids in order to capture the target for confirmatory assays and recycling of the sheath fluid. Fluorescently coded microspheres provide the capability for highly ...


Phosphate Industry And The Radon Problem, Fathi Habashi 2010 Laval University, Quebec City, Canada

Phosphate Industry And The Radon Problem, Fathi Habashi

Fathi Habashi

The problem of radon generated during the treatment of phosphate rock by sulfuric acid to produce fertilizers can be solved by using nitric acid. In this case radium, which is the source of radon, goes into solution and can be precipitated by a controlled method and safely disposed of. A variety of options are discussed. Text in Farsi with English translation.


East Bay Energy Consortium Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium 2010 Roger Williams University

East Bay Energy Consortium Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium

East Bay Energy Consortium Meeting Minutes

No abstract provided.


East Bay Energy Consortium, Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium 2010 Roger Williams University

East Bay Energy Consortium, Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium

East Bay Energy Consortium Meeting Minutes

No abstract provided.


East Bay Energy Consortium Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium 2010 Roger Williams University

East Bay Energy Consortium Joint Committee Workshop At The Bristol Town Hall, Burnside Building, February 24, 2010, Meeting Notes, East Bay Energy Consortium

East Bay Energy Consortium Meeting Minutes

No abstract provided.


Benefits And Pitfalls Of Virtual R&D Teams: An Empirical Study, Nader Ale Ebrahim, Shamsuddin Ahmed, Zahari Taha 2010 University of Malaya

Benefits And Pitfalls Of Virtual R&D Teams: An Empirical Study, Nader Ale Ebrahim, Shamsuddin Ahmed, Zahari Taha

Nader Ale Ebrahim

In this paper, advantages and drawbacks of virtual teams in research and development (R&D) are studied. With the globalization of commercial practices and advances in information and communication technologies, increasing numbers of enterprises are establishing cross-functional, geographically distributed virtual teams. Virtual teams in R&D are designed to access external resources and knowledge to maximize the competitive advantage from limited labor and resources. A survey has been conducted on 210 Malaysian and Iranian manufacturing companies, aimed to investigate the characteristics of R&D collaborations and extract the main advantages/disadvantages’ factors of virtual teams. These factors can be a ...


Temperature Dependence Of Thermal Conductivity Enhancement In Single-Walled Carbon Nanotube/Polystyrene Composites, Michael B. Jakubinek, Mary Anne White, Minfang Mu, Karen I. Winey 2010 Dalhousie University

Temperature Dependence Of Thermal Conductivity Enhancement In Single-Walled Carbon Nanotube/Polystyrene Composites, Michael B. Jakubinek, Mary Anne White, Minfang Mu, Karen I. Winey

Departmental Papers (MSE)

The thermal conductivity of single-walled carbon nanotube (SWCNT)/polystyrene composites, prepared by a method known to produce a uniform distribution of SWCNT bundles on the micrometer length scale, was measured in the temperature range from approximately 140 to 360 K. The thermal conductivity enhancement (50% for 1 mass % at 300 K) is reasonably constant above room temperature but is reduced at the lower temperatures. This result is consistent with the expected, large contribution of interfacial thermal resistance in SWCNT/polymer composites. Enhancements in electrical conductivity show that 1 mass % loading is in the region of the electrical percolation threshold.


Symmetry Transition In Thin Films Of Diblock Copolymer/Homopolymer Blends, Vindhya Mishra, Su-Mi Hur, Eric W. Cochran, Gila E. Stein, Glenn H. Fredrickson, Edward J. Kramer 2010 University of California, Santa Barbara

Symmetry Transition In Thin Films Of Diblock Copolymer/Homopolymer Blends, Vindhya Mishra, Su-Mi Hur, Eric W. Cochran, Gila E. Stein, Glenn H. Fredrickson, Edward J. Kramer

Chemical and Biological Engineering Publications

The effect of blending small weight fractions of low molecular weight majority block homopolymer on the structure of multilayer films of spherical morphology poly(styrene-b-2vinylpyridine) [PS−P2VP] has been studied. The structure of the films was characterized with grazing-incidence small-angle X-ray scattering (GISAXS) and transmission electron microscopy (TEM). In multilayer films of PS−P2VP, competition between hexagonal packing of the spherical domains preferred at the surfaces with the BCC (110) packing preferred by the internal layers leads to a transition in the packing symmetry as the number of sphere layers (n) is increased.(1) Neat PS−P2VP exhibits ...


Frequency Response And Gain Enhancement Of Solid-State Impact-Ionization Multipliers (Sims), Joshua L. Beutler 2010 Brigham Young University - Provo

Frequency Response And Gain Enhancement Of Solid-State Impact-Ionization Multipliers (Sims), Joshua L. Beutler

All Theses and Dissertations

A study of the frequency response and gain of Solid-state the Impact-ionization Multiplier (SIM). The SIM generates current gain via impact ionization also known as avalanche gain. The SIM provides low noise amplification from an arbitrary current source. In the case of this study, current sources consisted of photodiodes optimized for a particular wavelength of light. The SIM is fabricated from silicon and enjoys the low noise, low carrier transit time advantages of conventional silicon impact ionization devices while amplifying current from a photodiode of a different material. This is advantageous because ideal detection and multiplication regions cannot always be ...


The Carillon And Its Haptic Signature : Modeling The Changing Force-Feedback Constraints Of A Musical Instrument For Haptic Display, Mark Havryliv, F. Geiger, M. Gurtler, Fazel Naghdy, Greg Schiemer 2010 University of Wollongong

The Carillon And Its Haptic Signature : Modeling The Changing Force-Feedback Constraints Of A Musical Instrument For Haptic Display, Mark Havryliv, F. Geiger, M. Gurtler, Fazel Naghdy, Greg Schiemer

Greg Schiemer

The carillon is one of the few instruments that elicits sophisticated haptic interaction from amateur and professional players alike. Like the piano keyboard, the velocity of a player’s impact on each carillon key, or baton, affects the quality of the resultant tone; unlike the piano, each carillon baton returns a different force-feedback. Force-feedback varies widely from one baton to the next across the entire range of the instrument and with further idiosyncratic variation from one instrument to another. This makes the carillon an ideal candidate for haptic simulation. The application of synthesized forcefeedback based on an analysis of forces ...


Optimized Stochastic Resonance Method For Signal Detection And Image Processing, Hao Chen, P. K. Varshney, J. H. Michels 2010 Boise State University

Optimized Stochastic Resonance Method For Signal Detection And Image Processing, Hao Chen, P. K. Varshney, J. H. Michels

Hao Chen

Apparatus and method for improving the detection of signals obscured by noise using stochastic resonance noise. The method determines the stochastic resonance noise probability density function in non-linear processing applications that is added to the observed data for optimal detection with no increase in probability of false alarm. The present invention has radar, sonar, signal processing (audio, image and video), communications, geophysical, environmental, and biomedical applications.


Importance Of Including Ammonium Sulfate ((Nh4)2so4) Aerosols For Ice Cloud Parameterization In Gcms, P.S. Bhattacharjee, Y.C. Sud, Xiaohong Liu, G.K. Walker, R. Yang, J. Wang 2010 George Mason University

Importance Of Including Ammonium Sulfate ((Nh4)2so4) Aerosols For Ice Cloud Parameterization In Gcms, P.S. Bhattacharjee, Y.C. Sud, Xiaohong Liu, G.K. Walker, R. Yang, J. Wang

Atmospheric Science Faculty Publications

A common deficiency of many cloud-physics parameterizations including the NASA's microphysics of clouds with aerosol-cloud interactions (hereafter called McRAS-AC) is that they simulate lesser (larger) than the observed ice cloud particle number (size). A single column model (SCM) of McRAS-AC physics of the GEOS4 Global Circulation Model (GCM) together with an adiabatic parcel model (APM) for ice-cloud nucleation (IN) of aerosols were used to systematically examine the influence of introducing ammonium sulfate (NH4)2SO 4 aerosols in McRAS-AC and its influence on the optical properties of both liquid and ice clouds. First an (NH4)2SO4 parameterization was included in ...


Experimental Verification Of The Suppression Of Spatial Dispersion In Artificial Plasma, Olli Luukonen, Pekka Alitalo, Filippo Costa, Constantin Simovski, Agostino Monorchio, Sergei Tretyakov 2010 University of Pennsylvania, Aalto University

Experimental Verification Of The Suppression Of Spatial Dispersion In Artificial Plasma, Olli Luukonen, Pekka Alitalo, Filippo Costa, Constantin Simovski, Agostino Monorchio, Sergei Tretyakov

Departmental Papers (ESE)

In this paper, we verify experimentally the recently proposed theory on suppression of the spatial dispersion in an artificial plasma. We make use of the image principle and assume effectively local material parameters of the artificial plasma, in which the spatial dispersion has been suppressed, and measure the reflection from an impenetrable grounded surface. The plasma resonance can be clearly distinguished from the measurement results at the plasma frequency independently from the incidence angle. The agreement between the measurement results and the theory and simulations is very good.


Relation Between Ga Ordering And Magnetostriction Of Fe-Ga Alloys Studied By X-Ray Diffuse Scattering, Y. Du, Mianliang Huang, S. Chang, Deborah L. Schlagel, Thomas A. Lograsso, Robert J. McQueeney 2010 Iowa State University

Relation Between Ga Ordering And Magnetostriction Of Fe-Ga Alloys Studied By X-Ray Diffuse Scattering, Y. Du, Mianliang Huang, S. Chang, Deborah L. Schlagel, Thomas A. Lograsso, Robert J. Mcqueeney

Ames Laboratory Publications

Transmission synchrotron diffraction was employed to characterize the Ga ordering in magnetostrictive Fe100−xGax alloys with Ga concentrations from 0 to 20.3 at. %. The experiments focused on the development of atomic short-range ordering (SRO) by analysis of the diffuse scattering appearing at superlattice positions of the D03 ordered alloy structure. No SRO was found for Ga concentrations less than 4 at. %. Between 13 and 20.3 at. %, D03-type SRO clusters are observed whose size increases with Ga concentration for both slow-cooled and quenched samples. Thermal quenching of the samples suppresses the cluster sizes ...


Effect Of Microreactor Geometry In Performance Of Catalytic Microreactor Of Hydrogen Production By Cfd Modeling, Mohsen Behnam, Ali Fazeli, Shohreh Fatemi, Yadolah Mortazavi, A. Khodadai 2010 University of Tehran

Effect Of Microreactor Geometry In Performance Of Catalytic Microreactor Of Hydrogen Production By Cfd Modeling, Mohsen Behnam, Ali Fazeli, Shohreh Fatemi, Yadolah Mortazavi, A. Khodadai

Ali Fazeli

Hydrogen production from steam reforming of methanol for fuel cell application was modeled in a wall coated micro channel reactor by CFD approach. Heat of steam reforming was supplied from catalytic total oxidation (TOX) of methanol in neighboring channel of steamreforming (SR) channel and conduct from TOX to SR channel through metal divider wall of the channels. Heat integration was compared in zigzag and straight geometry of microreactor by CFD modeling. The model is 2 dimensional, steady state and containing five zones: TOX fluid, TOX catalyst layer, steel wall of the channel, SR catalyst layer, SR fluid. Set of partial ...


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