Physics Commons^™

A Benchmark Study On The Thermal Conductivity Of Nanofluids, Jacopo Buongiomo, David C. Venerus, Naveen Prabhat, Thomas Mckrell, Jessica Townsend, Rebecca Christianson, Yuriv V. Tolmachev, Pawel Keblinski, Lin-Wen Hu, Jorge L. Alvarado, In Cheol Bang, Sandra W. Bishnoi, Marco Bonetti, Anselmo Cecere, Yun Chang, Gang Chen, Haisheng Chen, Sung Jae Chung, Minking K. Chyu, Sarit K. Das, Roberto Di Paola, Yulong Ding, Frank Dubois, Grzegorz Dzido, Jacob Eapen, Denis Funfschilling, Quentin Galand, Jinwei Gao, Patricia E. Gharagozloo, Kenneth E. Goodson, Jorge Gustavo Gutierrez, Haiping Hong, Mark Horton, Kyo Sik Hwang, Carlo S. Iorio, Seok Pil Jang, Andrzej B. Jarzebski, Yiran Jiang, Stephan Kabelac, Liwen Jin, Aravind Kamath, Chongyoup Kim, Ji-Hyun Kim, Seokwon Kim, Seung Hyun Lee, Kai Choong Leong, Indranil Manna, Rui Ni, Hrishikesh E. Patel, Cecil Reynaud, Raffaele Savino, Pawan K. Singh, Pengxiang Song, Thirumalachari Sundararajan, Alekzandr N. Turanov, Stefan Van Vaerenbergh, Dongsheng Wen, Sanjeeva Witharana, Chun Yang, Wei-Hsun Yeh, Xiao-Zheng Zhao, Sheng-Qi Zhou

Rebecca J. Christianson

This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady-state methods, and optical methods. The nanofluids tested in the exercise were comprised of aqueous and nonaqueous basefluids, metal and metal oxide particles, near-spherical and elongated particles, at low and high particle concentrations. The data analysis reveals that the data from most organizations lie within a relatively narrow band (±10% or less) about …

Fractional Trigonometric Functions In Complex-Valued Space: Applications Of Complex Number To Local Fractional Calculus Of Complex Function, Yang Xiao-Jun

Xiao-Jun Yang

This paper presents the fractional trigonometric functions in complex-valued space and proposes a short outline of local fractional calculus of complex function in fractal spaces.

Temporal And Spatial Aspects Of Gas Release During The 2010 Apparition Of Comet 103p/Hartley 2, M. J. Mumma, B. P. Bonev, G. L. Villanueva, L. Paganini, M. A. Disanti, E. L. Gibb, J. V. Keane, K. J. Meech, G. A. Blake, R. S. Ellis, M. Lippi, H. Boehnhardt, K. Magee-Sauer

Erika Gibb

Investigation Of Electrical Transport In Hydrogenated Multiwalled Carbon Nanotubes, Adam Friedman, Hyunkyung Chun, Don Heiman, Yung Jung, Latika Menon

Latika Menon

Highly disordered multiwalled carbon nanotubes of large outer diameter (~60 nm) fabricated by means of chemical vapor deposition process inside porous alumina templates exhibit ferromagnetism when annealed in a H2/Ar atmosphere. In the presence of an applied magnetic field, there is a transition from positive to negative magnetoresistance. The transition may be explained in terms of the Bright model for ordered and disordered carbon structures. Additionally, temperature dependent electrical transport experiments exhibit a zero-bias anomaly at low temperature.

Ferroelectric Polymer Langmuir–Blodgett Films For Nonvolatile Memory Applications, Stephen Ducharme, Timothy J. Reece, Christina M. Othon, R. K. Rannow

Christina M Othon

We review the potential for integrating ferroelectric polymer Langmuir–Blodgett (LB) films with semiconductor technology to produce nonvolatile ferroelectric random-access memory (NV-FRAM or NV-FeRAM) and data-storage devices. The prototype material is a copolymer consisting of 70% vinylidene fluoride (VDF) and 30% trifluoroethylene (TrFE), or P(VDF-TrFE 70:30). Recent work with LB films and more conventional solventformed films shows that the VDF copolymers are promising materials for nonvolatile memory applications. The prototype device is themetal–ferroelectric–insulator–semiconductor (MFIS) capacitance memory. Field-effect transistor (FET)-based devices are also discussed. The LB films afford devices with low-voltage operation, but there are two important technical hurdles that must be …

The Effects Of Humidity On The Dielectric Response In Ferroelectric Polymer Films Made By Langmuir-Blodgett Deposition, Kristin Kraemer, Alexander Sorokin, Christina Othon, Stephen Ducharme, Vladimir Fridkin

Christina M Othon

No abstract provided.

Electron Irradiation Effects On Ferroelectric Copolymer Langmuir-Blodgett Films, Christina M. Othon, Stephen Ducharme

Christina M Othon

The effect of irradiation on the ferroelectric properties of Langmuir-Blodgett films of the copolymer poly(vinylidene fluoride-trifluorethelene) is investigating using 1.26 MeV electrons with dosages from 16 to 110 Mrad. Irradiation causes a systematic decrease in the phase transition temperature, coercive field and polarization of these thin films.

Laser Excited Population Redistribution In The 2p^53p Multiplet In Neon, Naveed Piracha, K. Duncan-Chamberlain, R. Ali, M. Kalyar, M. Mehmood, R. Ahmed, M. Baig

Naveed K. Piracha

Using neon hollow cathode lamp and employing laser optogalvanic technique, we have studied population redistribution in the 2p^53p multiplet. The spectra recorded in the laser energy region of 23300cm^-^1 -23600cm^-^1 show transitions originating from both the laser excited levels as well as from an adjacent level whose population builds up as a result of collisional deactivation. Employing the optical delay technique, we have been able to extract decay rates associated with the collisional population mixing of the p levels.

Mesosphereic Temperature Variability And Seasonal Characteristics Over The Andes, Jonathan R. Pugmire, Yucheng Zhao, Michael J. Taylor, Dominique Pautet

Jonathan Pugmire

The Utah State University CEDAR Mesospheric Temperature Mapper (MTM) is a high-quality CCD imager capable of remote sensing faint optical emissions from the night sky to determine mesospheric temperature and its variability at an altitude of ~87 km. The MTM was operated at the new Andes Lidar Observatory (ALO)located at Cerro Pachon, Chile (30.2° S, 70.7° W) since August 2009 to investigate the seasonal characteristic of the mesopause at mid-latitudes. Measurement were made alongside a powerful lidar capable of height sounding the mesosphere. In this study, the MTM data have been analyzed to determine night to night variability and seasonal …

The Penetration Of Social Media In Governance,Political Reforms And Building Public Perception, Ratnesh Dwivedi Mr

Ratnesh Dwivedi

Social media are media for social interaction, using highly accessible and scalable communication techniques. Social media is the use of web-based and mobile technologies to turn communication into interactive dialogue. While we know that social media can play an important role in publicizing political activities such as protests, do we have evidence that such actions have led to substantive political change? Is it possible to develop a set of indicators to more effectively gauge the impact of new technologies and media on questions of political change? That social media can help coordinate large and discrete activities, such as protests and …

Nanoengineering Of A Negative-Index Binary-Staircase Lens For The Optics Regime, Bernard Didier F. Casse, Ravinder K. Banyal, W. T. Lu, Y. J. Huang, Selvapraba Selvarasah, Mehmet R. Dokmeci, Srinivas Sridhar

Mehmet R. Dokmeci

We show that a binary-staircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The mechanism for achieving a negative-index lens is based on exploiting the periodicity of the surface corrugation. By designing and nanofabricating a planoconcave binary-staircase lens in the InP/InGaAsP platform, we have experimentally demonstrated at 1.55 μm that such negative-index concave lenses can focus plane waves. The beam propagation in the lens was studied experimentally and was in excellent agreement with the three-dimensional finite-difference time-domain numerical simulations.

Nanoengineering Of A Negative-Index Binary-Staircase Lens For The Optics Regime, Bernard Didier Casse, Ravinder Banyal, W. Lu, Y. Huang, Selvapraba Selvarasah, Mehmet Dokmeci, Srinivas Sridhar

Srinivas Sridhar

We show that a binary-staircase optical element can be engineered to exhibit an effective negative index of refraction, thereby expanding the range of optical properties theoretically available for future optoelectronic devices. The mechanism for achieving a negative-index lens is based on exploiting the periodicity of the surface corrugation. By designing and nanofabricating a planoconcave binary-staircase lens in the InP/InGaAsP platform, we have experimentally demonstrated at 1.55 μm that such negative-index concave lenses can focus plane waves. The beam propagation in the lens was studied experimentally and was in excellent agreement with the three-dimensional finite-difference time-domain numerical simulations.

Microwave Absorption Of Patterned Arrays Of Nanosized Magnetic Stripes With Different Aspect Ratios, Leszek M. Malkinski, Minghui Yu, Andriy Y. Voyk, Donald J. Scherer Ii, Leonard Spinu, Weillie Zhou, Scott Whittenburg, Zachary Davis, Jin-Seung Jung

Scott L Whittenburg

Arrays consisting of nanosized stripes of Permalloy with different length-to-width ratios have been fabricated using electron beam nanolithography, magnetron sputtering, and lift-off process. These stripes have a thickness of 100 nm, a width of 300 nm, and different lengths ranging from 300 nm to 100 μm. The stripes are separated by a distance of 1 μm. Magnetization hysteresis loops were measured using a superconducting quantum interference device susceptometer. Microwave absorption at 9.8 GHz was determined by means of ferromagnetic resonance technique. The dependence of the resonant field on the angle between the nanostructure and the in-plane dc magnetic field indicates …

Electron Self-Injection Into An Evolving Plasma Bubble: Quasi-Monoenergetic Laser-Plasma Acceleration In The Blowout Regime, Serguei Y. Kalmykov, Arnaud Beck, Sunghwan A. Yi, Vladimir N. Khudik, Michael C. Downer, Erik Lefebvre, Bradley A. Shadwick, Donald P. Umstadter

Donald P. Umstadter

An electron density bubble driven in a rarefied uniform plasma by a slowly evolving laser pulse goes through periods of adiabatically slow expansions and contractions. Bubble expansion causes robust self-injection of initially quiescent plasma electrons, whereas stabilization and contraction terminate self-injection thus limiting injected charge; concomitant phase space rotation reduces the bunch energy spread. In regimes relevant to experiments with hundred terawatt- to petawatt-class lasers, bubble dynamics and, hence, the self-injection process are governed primarily by the driver evolution. Collective transverse fields of the trapped electron bunch reduce the accelerating gradient and slow down phase space rotation. Bubble expansion followed …

Electron Self-Injection Into An Evolving Plasma Bubble: Quasi-Monoenergetic Laser-Plasma Acceleration In The Blowout Regime, Serguei Y. Kalmykov, Arnaud Beck, Sunghwan A. Yi, Vladimir N. Khudik, Michael C. Downer, Erik Lefebvre, Bradley A. Shadwick, Donald P. Umstadter

Serge Youri Kalmykov

An electron density bubble driven in a rarefied uniform plasma by a slowly evolving laser pulse goes through periods of adiabatically slow expansions and contractions. Bubble expansion causes robust self-injection of initially quiescent plasma electrons, whereas stabilization and contraction terminate self-injection thus limiting injected charge; concomitant phase space rotation reduces the bunch energy spread. In regimes relevant to experiments with hundred terawatt- to petawatt-class lasers, bubble dynamics and, hence, the self-injection process are governed primarily by the driver evolution. Collective transverse fields of the trapped electron bunch reduce the accelerating gradient and slow down phase space rotation. Bubble expansion followed …

Two Faces Of Media While Covering Human Right Activities In India, Ratnesh Dwivedi Mr

Ratnesh Dwivedi

The situation of human rights in India is a complex one, as a result of the country's large size and tremendous diversity, its status as a developing country and a sovereign, secular, democratic republic, and its history as a former colonial territory. The Constitution of India provides for Fundamental rights, which include freedom of religion. Clauses also provide for Freedom of Speech, as well as separation of executive and judiciary and freedom of movement within the country and abroad. In its report on human rights in India during 2010, Human Rights Watch stated India had "significant human rights problems". They …

Electronic Transport In Oxygen Deficient Ferromagnetic Semiconducting Tio$_{2-\Delta}$, Soack Dae Yoon, Vincent G. Harris, Carmine Vittoria, A. Widom

Vincent G. Harris

TiO$_{2-\delta}$ films were deposited on (100) Lanthanum aluminates LaAlO$_{3}$ substrates at a very low oxygen chamber pressure $P\approx 0.3$ mtorr employing a pulsed laser ablation deposition technique. In previous work, it was established that the oxygen deficiency in these films induced ferromagnetism. In this work it is demonstrated that this same oxygen deficiency also gives rise to semiconductor titanium ion impurity donor energy levels. Transport resistivity measurements in thin films of TiO$_{2-\delta}$ are presented as a function of temperature and magnetic field. Magneto- and Hall- resistivity is explained in terms of electronic excitations from the titanium ion donor levels into …

Shape Selection Of Twist-Nematic-Elastomer Ribbons, Yoshiki Sawa, Fangfu Ye, Kenji Urayama, Toshikazu Takigawa, Vianney Gimenez-Pinto, Robin Selinger, Jonathan Selinger

Robin Selinger

How microscopic chirality is reflected in macroscopic scale to form various chiral shapes, such as straight helicoids and spiral ribbons, and how the degree of macroscopic chirality can be controlled are a focus of studies on the shape formation of many biomaterials and supramolecular systems. This article investigates both experimentally and theoretically how the chiral arrangement of liquid crystal mesogens in twist-nematic-elastomer films induces the formation of helicoids and spiral ribbons because of the coupling between the liquid crystalline order and the elasticity. It is also shown that the pitch of the formed ribbons can be tuned by temperature variation. …

~115 Gev And ~143 Gev Higgs Mass Considerations Within The Composite Particles Model, Marko Popovic

Marko B. Popovic

The radiatively generated Higgs mass is obtained by requiring that leading “divergences” are cancelled in both 2D and 4D. This predicts that the k=1 mode mass is ݉ ு ≅ ଶ ଷ݉ ௧ ؆ ͳͳͷܩܸ݁ whereas the k=2 mode is ؆ ͳͶ͵ ܩܸ݁. These findings are interpreted within the Composite Particles Model (CPM), [Popovic 2002, 2010], with the massive top quark being a baryon-like structure composed of 3 fundamental О quarks and the massive Higgs scalar being a color-neutral meson like structure composed of 2 fundamental О quarks. The CPM predicts that the Z mass generation is mediated primarily by …

Characterization Of Continuous Vacuum Ultraviolet Lamps-Implication On The Study Of Methane Photolysis At Lyman Alpha (121.6 Nm), M-C. Gazeau, Y. Benilan, Et. Es-Sebbar, A. Jolly, E. Arzoumanian, N. Fray, H. Cottin

Dr. Et-touhami Es-sebbar

Low-temperature hydrogen plasmas are widely used as continuous vacuum ultraviolet irradiation sources in photochemical studies and, in particular, in laboratory simulations of planetary atmospheres. One of the most challenging objectives of such experiments is to retrieve accurate quantitative laboratory data allowing a reliable comparison with theoretical and/or observational ones. This task can only be achieved when the irradiation source delivers a well characterised radiation in terms of flux and wavelength dependency. As an example, we will present a study, developed in the frame of a program dedicated to simulations of Titan’s atmosphere, on methane photolysis at Lyman alpha (121.6 nm). …

Formation Of Hcn And Nh3 As Primary Compounds Of Titan’S Atmosphere Simulations Using N2-Ch4 Afterglow Plasma’’, M-C. Gazeau, Y. Bénilan, E. Arzoumanian, Et. Es-Sebbar, A. Jolly, C.D. Pintassilgo

Dr. Et-touhami Es-sebbar

No abstract provided.

Language Discourse- A Critical Analysis Of Michel Focault's Work On Language Discourse With Special Reference To His Masterpiece "The Archeology Of Knowledge", Ratnesh Dwivedi Mr

Ratnesh Dwivedi

Discourse generally refers to "written or spoken communication or debate". The following are three more specific definitions: (1) In semantics and discourse analysis: A generalization of the concept of conversation to all modalities and contexts. (2) "The totality of codified linguistic usages attached to a given type of social practice. (E.g.: legal discourse, medical discourse, religious discourse.)" (3) In the work of Michel Foucault, and social theorists inspired by him: "an entity of sequences of signs in that they are enouncements (enoncés)" (Foucault 1969: 141). An enouncement (often translated as "statement") is not a unity of signs, but an abstract …

Liquid Crystals, Photonic Crystals, Metamaterials, And Transformation Optics, Oleg Lavrentovich

Oleg Lavrentovich

No abstract provided.

Argon Rectification And The Cause Of Light Emission In Single-Bubble Sonoluminescence, Brian D. Storey, Andrew J. Szeri

Brian Storey

In single-bubble sonoluminescence, repeated brief flashes of light are produced in a gas bubble strongly driven by a periodic acoustic field. A startling hypothesis has been made by Lohse and co-workers [Phys. Rev. Lett. 78, 1359 (1997)] that the non-noble gases in an air bubble undergo chemical reaction into soluble products, leaving only argon. In the present work, this dissociation hypothesis is supported by simulations, although the associated temperatures of about 7000 K seem too low for bremsstrahlung, which has been proposed as the dominant light emission mechanism. This suggests that emission from water vapor and its reaction products, heretofore …

Nonlinear Electrokinetics At Large Voltages, Martin Z. Bazant, Mustafa Sabri Kilic, Brian D. Storey, Armand Ajdari

Brian Storey

Part of Focus on Micro- and Nanofluidics The classical theory of electrokinetic phenomena assumes a dilute solution of point-like ions in chemical equilibrium with a surface whose double-layer voltage is of order the thermal voltage, kBT/e=25 mV. In nonlinear 'induced-charge' electrokinetic phenomena, such as ac electro-osmosis, several volts 100kBT/e are applied to the double layer, and the theory breaks down and cannot explain many observed features. We argue that, under such a large voltage, counterions 'condense' near the surface, even for dilute bulk solutions. Based on simple models, we predict that the double-layer capacitance decreases and the electro-osmotic mobility saturates …

Shape Stability Of Sonoluminescence Bubbles: Comparison Of Theory To Experiments, Brian D. Storey

Brian Storey

Single bubble sonoluminescence (SBSL) is the brief flash of light emitted from a single, stable, acoustically forced bubble. In experiments, the maximum pressure amplitude with which a bubble may be forced is limited by considerations of spherical stability. The traditional linear stability analysis predicts a threshold for SBSL at a much lower pressure amplitude than experimental observations. This work shows that if one constructs an accurate model of the radial dynamics, the traditional linear stability analysis predicts a boundary that is in excellent agreement with experimental data.

Field-Amplified Sample Stacking And Focusing In Nanofluidic Channels, Jess M. Sustarich, Brian D. Storey, Sumita Pennathur

Brian Storey

Nanofluidic technology is gaining popularity for bioanalytical applications due to advances in both nanofabrication and design. One major obstacle in the widespread adoption of such technology for bioanalytical systems is efficient detection of samples due to the inherently low analyte concentrations present in such systems. This problem is exacerbated by the push for electronic detection, which requires an even higher sensor-local sample concentration than optical detection. This paper explores one of the most common preconcentration techniques, field-amplified sample stacking, in nanofluidic systems in efforts to alleviate this obstacle. Holding the ratio of background electrolyte concentrations constant, the parameters of channel …

Rayleigh-Taylor Instability Of Violently Collapsing Bubbles, Hao Lin, Brian D. Storey, Andrew J. Szeri

Brian Storey

In a classical paper Plesset has determined conditions under which a bubble changing in volume maintains a spherical shape. The stability analysis was further developed by Prosperetti to include the effects of liquid viscosity on the evolving shape modes. In the present work the theory is further modified to include the changing density of the bubble contents. The latter is found to be important in violent collapses where the densities of the gas and vapor within a bubble may approach densities of the liquid outside. This exerts a stabilizing influence on the Rayleigh–Taylor mechanism of shape instability of spherical bubbles. …

Electrohydrodynamic Instabilities In Microchannels With Time Periodic Forcing, David A. Boy, Brian D. Storey

Brian Storey

In microfluidic applications it has been observed that flows with spatial gradients in electrical conductivity are unstable under the application of sufficiently strong electric fields. These electrohydrodynamic instabilities can drive a nonlinear flow despite the low Reynolds number. Such flows hold promise as a simple mechanism for mixing fluids. In this work, the effect of a time periodic electric field on the instability is explored. The case where an electric field is applied across a diffuse interface of two fluids with varying electrical conductivity is considered. Frequency-dependent behavior is found only in the regime where the instability growth rates are …

Bistability In A Simple Fluid Network Due To Viscosity Contrast, John B. Geddes, Brian D. Storey, David Gardner, Russell T. Carr

Brian Storey

We study the existence of multiple equilibrium states in a simple fluid network using Newtonian fluids and laminar flow. We demonstrate theoretically the presence of hysteresis and bistability, and we confirm these predictions in an experiment using two miscible fluids of different viscosity—sucrose solution and water. Possible applications include blood flow, microfluidics, and other network flows governed by similar principles.