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Articles 61 - 90 of 179

Full-Text Articles in Physical Sciences and Mathematics

Laboratory Manual For Physics, Gary Lewis Jan 2012

Laboratory Manual For Physics, Gary Lewis

Gary C. Lewis

No abstract provided.


Interactive Learningware For Physics Vol. 1: Mechanics, Thermodynamics, Waves, James Tanner, Gary Lewis Jan 2012

Interactive Learningware For Physics Vol. 1: Mechanics, Thermodynamics, Waves, James Tanner, Gary Lewis

Gary C. Lewis

Retaining the comprehensiveness and rigor of the previous edition, this sequel has been dramatically revised to be more student oriented. Definitions and issues have been improved, making them tighter and more easily understood. More than 400 sample problems have been updated and expanded to reinforce physics concepts. Formulas involving elements of calculus are better explained due to additional subsections. A wealth of animated illustrations and full-color photographs will capture today's visually-oriented students' attention.


Interactive Learningware For Physics Vol. 2: Fundamentals Of Physics, James Tanner, Gary Lewis Jan 2012

Interactive Learningware For Physics Vol. 2: Fundamentals Of Physics, James Tanner, Gary Lewis

Gary C. Lewis

Retaining the comprehensiveness and rigor of the previous edition, this sequel has been dramatically revised to be more student oriented. Definitions and issues have been improved, making them tighter and more easily understood. More than 400 sample problems have been updated and expanded to reinforce physics concepts. Formulas involving elements of calculus are better explained due to additional subsections. A wealth of animated illustrations and full-color photographs will capture today's visually-oriented students' attention.


Structural, Optical And Electrical Properties Of Europium Picrate Tetraethylene Glycol Complex As Emissive Material For Oled, Wan Haliza Abd Majid Dec 2011

Structural, Optical And Electrical Properties Of Europium Picrate Tetraethylene Glycol Complex As Emissive Material For Oled, Wan Haliza Abd Majid

Wan Haliza binti Abd Majid

A new europium complex [Eu(Pic) 2(H 2O)(EO4)](Pic) ·0.75H 2O was synthesized and used as the emission material for the single layer device structure of ITO/EO4EuPic/Al, using a spin-coating technique. Study on the optical properties of the [Eu(Pic) 2(H 2O)(EO4)](Pic)·0.75H 2O complex where EO4=tetraethylene glycol and Pic=picrate anion, had to be undertaken before being applicable to the study of an organic light emitting diode (OLED). The electrical property of an OLED using currentvoltage (IV) measurement was also studied. In complex, the Eu(III) ion was coordinated with the EO4 ligand as a pentadentate mode, one water molecule, and with two Pic anions …


Synthesis, Magnetic Properties And X-Ray Analysis Of Zn0.97x0.03o Nanoparticles (X = Mn, Ni, And Co) Using Scherrer And Size-Strain Plot Methods, Wan Haliza Abd Majid Dec 2011

Synthesis, Magnetic Properties And X-Ray Analysis Of Zn0.97x0.03o Nanoparticles (X = Mn, Ni, And Co) Using Scherrer And Size-Strain Plot Methods, Wan Haliza Abd Majid

Wan Haliza binti Abd Majid

Un-doped and doped ZnO nanoparticles (Zn0.97X0.03O-NPs, X = Mn, Co, and Ni) were synthesized from a metal acetate precursor and acetic acid by a modified sol gel combustion method. The compounds were synthesized at calcination temperatures of 650 degrees C for 1 h. The synthesized un-doped/doped ZnO-NPs were characterized by X-ray diffraction analysis (XRD) and high-magnification transmission electron microscopy (TEM). The XRD results revealed that the sample product was crystalline with a hexagonal wurtzite phase. The TEM showed ZnO-NPs nearly spherical shapes and a non-uniform shape for doped ZnO-NPs. The crystalline development in the ZnO-NPs was investigated by X-ray peak …


Angular-Dependences Of Giant In-Plane And Interlayer Magnetoresistances In Bi2te3 Bulk Single Crystals, Zengji Yue Dec 2011

Angular-Dependences Of Giant In-Plane And Interlayer Magnetoresistances In Bi2te3 Bulk Single Crystals, Zengji Yue

Zengji Yue

Angular-dependences of in-plane and interlayer magnetotransport properties in n-type Bi2Te3 bulk single crystals have been investigated over a broad range of temperatures and magnetic fields. Giant in-plane magnetoresistances (MR) of up to 500% and interlayer MR of up to 200% were observed, respectively. The observed MR exhibits quadratic field dependences in low fields and linear field dependences in high fields. The angular dependences of the MR represent strong anisotropy and twofold oscillations. The observed angle-dependent, giant MR might result from the strong coulomb scattering of electrons as well as impurity scattering in the bulk conduction bands of n-type Bi2Te3. The …


Semitransparent Organic Solar Cells, F.R. Zhu Oct 2011

Semitransparent Organic Solar Cells, F.R. Zhu

Professor ZHU, Fu Rong

Compared to current silicon-based solar cells that are rigid, organic-based solar cells that use solution-based processing or low-cost non-vacuum deposition techniques are simpler and less expensive to manufacture. Organic photovoltaic cells can be made flexible, semitransparent and are light weight, offer more opportunities for application in new markets such as mobile electronics, disposable electronics, smart cards, digital applications, power generating windows, smart sensors, automotive, home appliances and outdoor lifestyle etc. Its unique flexibility and semi-transparency feature also adds a decorative and aesthetic dimension to the solar cells so that it can be used on curved and irregular surfaces – something …


Risk-Based Critical Infrastructure Protection Priorities For Emp And Solar Storms, George H. Baker Iii Sep 2011

Risk-Based Critical Infrastructure Protection Priorities For Emp And Solar Storms, George H. Baker Iii

George H Baker

The Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack has provided a compelling case for protecting civilian infrastructure against the effects of EMP. As with protecting infrastructure against any hazard, it will be important to take a risk-based priority approach for EMP, recognizing that it is fiscally impracticable to protect everything. In this regard, EMP is particularly challenging in that it interferes with electrical and electronic data, control, transmission, and communication systems organic to nearly all infrastructures in a simultaneous and wide-scale manner. And, for nuclear burst altitudes of 100s of kilometers, the exposed geography …


Measuring The Persistence Length Of Mcf7 Cell Microtubules In Vitro, Mitra Shojania-Feizabadi, Kiryako Mutafopulos, Adam Behr Jun 2011

Measuring The Persistence Length Of Mcf7 Cell Microtubules In Vitro, Mitra Shojania-Feizabadi, Kiryako Mutafopulos, Adam Behr

Mitra Shojania-Feizabadi

No abstract provided.


Multiple Spill Echoes Due To Anisotropic Spill Diffusion In He-3-He-4 Solutions, Rj Ragan, Wj Mullin Feb 2011

Multiple Spill Echoes Due To Anisotropic Spill Diffusion In He-3-He-4 Solutions, Rj Ragan, Wj Mullin

William J. Mullin

No abstract provided.


Higgs-Boson-Exchange Models Of Cp Violation And K-]2pi, Jf Donoghue, Js Hagelin, Br Holstein Feb 2011

Higgs-Boson-Exchange Models Of Cp Violation And K-]2pi, Jf Donoghue, Js Hagelin, Br Holstein

Barry R Holstein

Work by Deshpande and Sanda, which appears to invalidate Higgs-boson-exchange models of CP noninvariance, is buttressed by (i) use of the MIT bag model to calculate matrix elements, (ii) use of experimental rather than calculated numbers for the K→2π decay amplitude and the KL-KS mass difference, and (iii) inclusion of possible t-quark effects. We conclude that, barring accidental cancellations, such Higgs-boson-exchange models are incompatible with experiment.


Derivation Of The Weak Quark-Model Interaction Between Nucleons, Br Holstein Feb 2011

Derivation Of The Weak Quark-Model Interaction Between Nucleons, Br Holstein

Barry R Holstein

No abstract provided.


High Power Efficiency Tandem Organic Light-Emitting Diodes Based On Bulk Heterojunction Organic Bipolar Charge Generation Layer, Yh Chen, Js Chen, Dg Ma, Dh Yan, Lx Wang, F.R. Zhu Dec 2010

High Power Efficiency Tandem Organic Light-Emitting Diodes Based On Bulk Heterojunction Organic Bipolar Charge Generation Layer, Yh Chen, Js Chen, Dg Ma, Dh Yan, Lx Wang, F.R. Zhu

Professor ZHU, Fu Rong

The significant enhancement in power efficiency of tandem organic light-emitting diodes (OLEDs) was achieved using bulk heterojunction organic bipolar charge generation layer (CGL), consisted of zinc phthalocyanine (ZcPc): fullerene (C60) blend. In addition to a significant enhancement in luminance and current efficiency this work yielded a maximum power efficiency of 21 lm/W measured for a tandem OLED, which is notably almost two times higher than that of a single-unit device, with a maximum power efficiency of 10.1 lm/W. The enhancement in power efficiency at higher luminance is also over 90%. The remarkable enhancement in power efficiency has been attributed to …


Preparation And Characterization Of Magnesium Ion Gel Polymer Electrolytes For Application In Electrical Double Layer Capacitors, Siti Rohana Majid, Asmara S. N., Kufian M. Z., Arof A. K. Dec 2010

Preparation And Characterization Of Magnesium Ion Gel Polymer Electrolytes For Application In Electrical Double Layer Capacitors, Siti Rohana Majid, Asmara S. N., Kufian M. Z., Arof A. K.

Siti Rohana Majid

This work describes the preparation and characterization of poly (methyl methacrylate) (PMMA) based gel polymer electrolytes with magnesium triflate (Mg(CF(3)SO(3))(2)) as the ion providing salt. Liquid electrolytes containing 0.4 M Mg(CF(3)SO(3))(2) in solvents comprising different ratios of ethylene carbonate (EC) and diethyl carbonate (DEC) have been prepared at room temperature. The highest conducting electrolyte contains EC and DEC in the weight ratio of 2:1. To the highest conducting liquid electrolyte, 25-50 wt.% PMMA has been added and the mixtures were heated at 80 degrees C for 2 min to form gel polymer electrolytes. The gel electrolyte with composition 40 wt.% …


Performance Enhancement In Organic Photovoltaic Devices Using Plasma-Polymerized Fluorocarbon-Modified Ag Nanoparticles, Xz Wang, Jw Ho, Qy Yang, Hl Tam, Gx Li, Kw Cheah, F.R. Zhu Dec 2010

Performance Enhancement In Organic Photovoltaic Devices Using Plasma-Polymerized Fluorocarbon-Modified Ag Nanoparticles, Xz Wang, Jw Ho, Qy Yang, Hl Tam, Gx Li, Kw Cheah, F.R. Zhu

Professor ZHU, Fu Rong

In this work, Ag nanoparticles were modified by an ultra-thin plasma-polymerized fluorocarbon film (CFX) to form a composite CFX -modified Ag nanoparticles/indium tin oxide (ITO) anode for application in organic photovoltaic (OPV) devices. A CFX-modified Ag nanoparticles/ITO anode exhibited a superior surface work function of 5.4 eV suited for application in OPV devices. The device performance of zinc phthalocyanine:fullerene-based OPV devices showed a significant improvement when the structural identical cells are made with the CFX-modified Ag nanoparticles/ITO. This work yielded a promising power conversion efficiency of 3.50.1%, notably higher than that with a bare ITO anode (2.70.1%).


Highly Photoactive Titanyl Phthalocyanine Polymorphs As Textured Donor Layers In Organic Solar Cells, Diogenes Placencia, Weining Wang, Jeremy Gantz, Judith Jenkins, Neal Armstrong Dec 2010

Highly Photoactive Titanyl Phthalocyanine Polymorphs As Textured Donor Layers In Organic Solar Cells, Diogenes Placencia, Weining Wang, Jeremy Gantz, Judith Jenkins, Neal Armstrong

Weining Wang, Ph.D.

No abstract provided.


First Year Investigation Of Gravity Waves And Temperature Variability Over The Andes., Jonathan Pugmire, Neal Criddle, Michael Taylor, Dominique Pautet, Yucheng Zhao Sep 2010

First Year Investigation Of Gravity Waves And Temperature Variability Over The Andes., Jonathan Pugmire, Neal Criddle, Michael Taylor, Dominique Pautet, Yucheng Zhao

Jonathan Pugmire

The Andes region is an excellent natural laboratory for investigating gravity wave influences on the Upper Mesospheric and Lower Thermospheric (MLT) dynamics: during the summer months the dominant gravity waves result from deep convection arising from severe thunderstorms over the continent to the east. In winter this convective activity is expected to be replaced by strong orographic forcing due to intense prevailing zonal winds blowing eastward from the Pacific Ocean and suddenly encountering the towering Andes mountain range (6000m). This creates large amplitude mountain waves that have been measured well into the stratosphere and most recently penetrate occasionally into the …


Towards High Efficiency Solution Processable Inverted Bulk Heterojunction Polymer Solar Cells Using Modified Indium-Tin-Oxide Cathode, Xh Chen, Jx Yang, Ly Xuan, C Laley, J Lu, F.R. Zhu, Kp Loh Dec 2009

Towards High Efficiency Solution Processable Inverted Bulk Heterojunction Polymer Solar Cells Using Modified Indium-Tin-Oxide Cathode, Xh Chen, Jx Yang, Ly Xuan, C Laley, J Lu, F.R. Zhu, Kp Loh

Professor ZHU, Fu Rong

No abstract provided.


Characteristics Of Methyl Cellulose-Nh4no3-Peg Electrolyte And Application In Fuel Cells, Siti Rohana Majid, Shuhaimi N. E. A., Alias N. A., Kufian M. Z., Arof A. K. Dec 2009

Characteristics Of Methyl Cellulose-Nh4no3-Peg Electrolyte And Application In Fuel Cells, Siti Rohana Majid, Shuhaimi N. E. A., Alias N. A., Kufian M. Z., Arof A. K.

Siti Rohana Majid

We report the viability of methyl cellulose (MC) as a membrane in a polymer electrolyte membrane fuel cell (PEMFC). Methyl cellulose serves as the polymer host, ammonium nitrate (NH4NO3) as the doping salt and poly(ethylene glycol) (PEG) as plasticizer. Conductivity measurement was carried out using electrochemical impedance spectroscopy. The room temperature conductivity of pure MC film is is (3.08 +/- 0.63) x 10(-11)S cm(-1). The conductivity increased to (2.10 +/- 0.37) x 10(-6)S cm(-1) on addition of 25 wt.% NH4NO3. By adding 15 wt.% of PEG 200 to the highest conducting sample in the MC-NH4NO3 system, the conductivity was further …


Neutrons And Hadronic Parity Violation, Br Holstein Sep 2009

Neutrons And Hadronic Parity Violation, Br Holstein

Barry R Holstein

The history and phenomenology of hadronic parity violation are reviewed, and the important role of the neutron in unlocking the physics of this subject is outlined.


Hadronic Parity Violation And Effective Field Theory, Br Holstein Jun 2009

Hadronic Parity Violation And Effective Field Theory, Br Holstein

Barry R Holstein

The history and phenomenology of hadronic parity violation is reviewed and a new modelindependent approach based on effective field theory is developed. Possible future developments are discussed.


Continuous Glucose Monitoring In Non-Insulin-Using Individuals With Type 2 Diabetes: Acceptability, Feasibility, And Teaching Opportunities, Nancy A. Allen, James A. Fain, Barry Braun, Stuart R. Chipkin Feb 2009

Continuous Glucose Monitoring In Non-Insulin-Using Individuals With Type 2 Diabetes: Acceptability, Feasibility, And Teaching Opportunities, Nancy A. Allen, James A. Fain, Barry Braun, Stuart R. Chipkin

Stuart R. Chipkin

Background: Continuous glucose monitoring (CGM) has the potential to provide useful data for behavioral interventions targeting non–insulin-using, sedentary individuals with type 2 diabetes mellitus (T2DM). The aims of this study were to describe CGM in terms of (1) feasibility and acceptability and (2) dietary- and exerciseteaching events. Methods: Cross-sectional data were analyzed from 27 non–insulin-using adults with T2DM who wore CGM for 72 h as part of a larger study on using CGM for exercise counseling in this population. Feasibility data included accuracy of entering daily self-monitored blood glucose (SMBG) readings and events (e.g., meals, exercise), sensor failures, alarms, optimal …


Target Finding Time For Microtubules In A Confined Geometry, Mitra Shojania-Feizabadi Dec 2008

Target Finding Time For Microtubules In A Confined Geometry, Mitra Shojania-Feizabadi

Mitra Shojania-Feizabadi

Dynamic instability of microtubules may reach the steady state with exponentially growing or decaying length distribution in a confined geometry such as a cell-like environment. In this brief communication, the target finding time for these microtubules with the stochastic polymerization in a confined geometry is compared with the reversible polymerization. It is shown that the efficiency of microtubules with increasing length distribution at the steady state depends on the location of a target. They are very efficient in finding a target located at the cell cortex, which confirms the significant biological role they play in rapidly reaching the cell cortex …


Large Area, Continuous, Few-Layered Graphene As Anodes In Organic Photovoltaic Devices, Y Wang, Xh Chen, Yl Zhong, F.R. Zhu, Kp Loh Dec 2008

Large Area, Continuous, Few-Layered Graphene As Anodes In Organic Photovoltaic Devices, Y Wang, Xh Chen, Yl Zhong, F.R. Zhu, Kp Loh

Professor ZHU, Fu Rong

No abstract provided.


Photochromic 3-Dimensional Actuator Based On An Uncrosslinked Liquid Crystal Elastomer, Hyong Choi, Kwang-Un Jeong, Liang-Chy Chien, Myong-Hoon Lee Dec 2008

Photochromic 3-Dimensional Actuator Based On An Uncrosslinked Liquid Crystal Elastomer, Hyong Choi, Kwang-Un Jeong, Liang-Chy Chien, Myong-Hoon Lee

Liang-Chy Chien

A chemically programmed photochromic liquid crystal (LC) polymer was newly synthesized and used to fabricate an actuator exhibiting reversible photo-activated bending behavior at ambient temperature. Due to the lack of chemical crosslinking in this photochromic LC elastomer, it was possible to fabricate an actuator in the form of fiber or film by melt or solution processing, respectively. The three-dimensional (3D) bending of the film actuator can be precisely controlled in various directions by polarized ultraviolet (UV) light. The novel photochromic LC elastomer, exhibiting reversible photomechanical bending with controlled directions at room temperature, is beneficial for the realization of wireless remote-controlled …


The Mysterious Disappearance Of Ettore Majorana - Art. No. 012019, Br Holstein Dec 2008

The Mysterious Disappearance Of Ettore Majorana - Art. No. 012019, Br Holstein

Barry R Holstein

We review the short but interesting life of Ettore Majorana.


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.


Chiral Perturbation Theory: An Effective Field Theory, Br Holstein Jun 2008

Chiral Perturbation Theory: An Effective Field Theory, Br Holstein

Barry R Holstein

The concept of an effective field theory (EFT), i.e. a theory which is valid only in a limited range of parameter space, is one which has become highly developed recently. After presenting familiar examples from the realms of classical and quantum mechanics together with condensed matter physics, we show that QCD has an intriguing parallel with superconductivity in that, by using quark–antiquark (mesonic) degrees of freedom and exploiting the symmetries of the theory, a useful and powerful theory–chiral perturbation theory–results, which offers a complete and rigorous description of low energy particle and nuclear physics.


Beam Dynamics In Pt Symmetric Optical Lattices, Konstantinos Makris, Ramy El-Ganainy, Demetrios Christodoulides, Z. Musslimani Mar 2008

Beam Dynamics In Pt Symmetric Optical Lattices, Konstantinos Makris, Ramy El-Ganainy, Demetrios Christodoulides, Z. Musslimani

Ramy El-Ganainy

The possibility of parity-time (PT) symmetric periodic potentials is investigated within the context of optics. Beam dynamics in this new type of optical structures is examined in detail for both one- and two- dimensional lattice geometries. It is shown that PT periodic structures can exhibit unique characteristics stemming from the nonorthogonality of the associated Floquet-Bloch modes. Some of these features include double refraction, power oscillations, and eigenfunction unfolding as well as nonreciprocal diffraction patterns.


Modeling Plasma Induced Dispersion In A Nonlinear Schrödinger Equation, Jeremy Gulley, William Dennis Feb 2008

Modeling Plasma Induced Dispersion In A Nonlinear Schrödinger Equation, Jeremy Gulley, William Dennis

Jeremy R. Gulley

Ultrafast laser pulse propagation in dielectrics is often modeled by a modified nonlinear Schrödinger equation (NLSE). At laser intensities sufficient to cause ionization, a plasma term can be included in the modified NLSE to account for free-carrier optical effects. This term is linear in the field and may be calculated from the classical Drude theory. We explore the consequences of a newly developed method for including dispersion relations of the plasma term as predicted by the Drude theory into the framework of the modified NLSE. The plasma induced dispersion terms can be shown to strongly effect ultrashort pulse evolution through …