Scitation - Search Results

The compass rose pattern in electricity prices

Fri, 16 Oct 2009 18:25:33 GMT

Jonathan A. Batten and Mahmoud Hamada
The compass rose pattern is known to appear in the phase portraits, or scatter diagrams, of the high-frequency returns of financial series. We first show that this pattern is also present in the returns of spot electricity prices. Early researchers investigating these phenomena hoped that these patt ... [Chaos 19, 043106 (2009)] published Fri Oct 16, 2009.

Fully bendable polymer light emitting devices with carbon nanotubes as cathode and anode

Thu, 19 Nov 2009 16:01:49 GMT

Zhibin Yu, Liangbing Hu, Zhitian Liu et al.
Polymer light emitting devices were fabricated by roll lamination using single-walled carbon nanotubes as both anode and cathode. The devices exhibited a low turn-on voltage of 3.8 V, high brightness of 1400 cd/m at 10 V and maximum efficiency of 2.2 cd/A at 480 cd/m. The devices are also highly t ... [Appl. Phys. Lett. 95, 203304 (2009)] published Thu Nov 19, 2009.

Origins of performance in fiber-based organic photovoltaics

Mon, 16 Nov 2009 21:15:08 GMT

Yuan Li, Wei Zhou, Dan Xue et al.
Using ray tracing and optical path iteration, we present a mathematical model for light transmission, absorption, and loss in fiber-based organic photovoltaics. Simulations based on this model give an optimum incident angle, position, and an optimum aspect ratio in terms of other parameters of the f ... [Appl. Phys. Lett. 95, 203503 (2009)] published Mon Nov 16, 2009.

Prediction of surface passivation doping of silicon nanowires with phosphorus

Wed, 11 Nov 2009 18:19:16 GMT

X. B. Yang, C. S. Guo, and R. Q. Zhang
We report a prediction of enhanced surface passivation doping effect in silicon nanowires (SiNWs) by phosphorus adsorption based on first-principles calculations. Recent theoretical and experimental studies all showed that hydrogen-passivated SiNWs present typical p-type characteristic due to charge ... [Appl. Phys. Lett. 95, 193105 (2009)] published Wed Nov 11, 2009.

Calculation of hydrogen storage capacity of metal-organic and covalent-organic frameworks by spillover

Mon, 02 Nov 2009 21:16:56 GMT

Mayur Suri, Matthew Dornfeld, and Eric Ganz
We have used accurate ab initio quantum chemistry calculations together with a simple model to study the hydrogen storage capacity of metal-organic and covalent-organic frameworks by spillover. Recent experiments by Tsao et al. [J. Am. Chem. Soc. 131, 1404 (2009)] {based on an earlier work by Li and ... [J. Chem. Phys. 131, 174703 (2009)] published Mon Nov 2, 2009.

First-principles study on the enhancement of lithium storage capacity in boron doped graphene

Wed, 04 Nov 2009 18:18:21 GMT

Xianlong Wang, Zhi Zeng, Hyojun Ahn et al.
The adsorption of Li ions on boron doped graphene was investigated using a first-principles method. Our results show that, as boron doping turns graphene into an electron-deficient system, more Li ions can be captured around boron doped centers than in pristine graphene. One boron atom doped into gr ... [Appl. Phys. Lett. 95, 183103 (2009)] published Wed Nov 4, 2009.

Effect of the change in the load resistance on the high voltage pulse transformer of the intense electron-beam accelerators

Fri, 20 Nov 2009 19:19:18 GMT

Xin-bing Cheng, Jin-liang Liu, Bao-liang Qian et al.
A high voltage pulse transformer (HVPT) is usually used as a charging device for the pulse forming line (PFL) of intense electron-beam accelerators (IEBAs). Insulation of the HVPT is one of the important factors that restrict the development of the HVPT. Until now, considerable effort has been focus ... [Rev. Sci. Instrum. 80, 115110 (2009)] published Fri Nov 20, 2009.

Quantum-coupled single-electron thermal to electric conversion scheme

Fri, 13 Nov 2009 16:55:36 GMT

D. M. Wu, P. L. Hagelstein, P. Chen et al.
Thermal to electric energy conversion with thermophotovoltaics relies on radiation emitted by a hot body, which limits the power per unit area to that of a blackbody. Microgap thermophotovoltaics take advantage of evanescent waves to obtain higher throughput, with the power per unit area limited by ... [J. Appl. Phys. 106, 094315 (2009)] published Fri Nov 13, 2009.

A novel capacitance sensor for fireside corrosion measurement

Thu, 12 Nov 2009 18:37:24 GMT

Heng Ban and Zuoping Li
Fireside corrosion in coal-fired power plants is a leading mechanism for boiler tube failures. Online monitoring of fireside corrosion can provide timely data to plant operators for mitigation implementation. This paper presents a novel sensor concept for measuring metal loss based on electrical cap ... [Rev. Sci. Instrum. 80, 115107 (2009)] published Thu Nov 12, 2009.

Recombination lifetimes in highly aluminum-doped silicon

Tue, 10 Nov 2009 18:37:23 GMT

Jan Schmidt, Nils Thiemann, Robert Bock et al.
We show that the recombination lifetimes measured in highly aluminum-doped p-type silicon (Al-p) regions, fabricated by means of screen printing and firing of aluminum paste, are three orders of magnitude larger than the lifetimes expected from the extrapolation of the lifetime data measured on alum ... [J. Appl. Phys. 106, 093707 (2009)] published Tue Nov 10, 2009.

Drift-diffusion modeling of photocurrent transients in bulk heterojunction solar cells

Mon, 09 Nov 2009 19:49:29 GMT

Inchan Hwang, Christopher R. McNeill, and Neil C. Greenham
We utilize a time-dependent drift-diffusion model incorporating electron trapping and field-dependent charge separation to explore the device physics of organic bulk-heterojunction solar cells based on blends of poly(3-hexylthiophene) (P3HT) with a red polyfluorene copolymer. The model is used to re ... [J. Appl. Phys. 106, 094506 (2009)] published Mon Nov 9, 2009.

Tidal flow over three-dimensional topography in a stratified fluid

Mon, 09 Nov 2009 19:47:48 GMT

Benjamin King, H. P. Zhang, and Harry L. Swinney
Our laboratory experiments and numerical simulations of stratified tidal flow past model topography (a half sphere on a horizontal plane) reveal several three-dimensional flow features, including an unexpected flow perpendicular to the forcing plane (the vertical plane through the center of the sphe ... [Phys. Fluids 21, 116601 (2009)] published Mon Nov 9, 2009.

Chemical engineering of prehydrogenated C and BN-sheets by Li: Application in hydrogen storage

Fri, 06 Nov 2009 18:18:11 GMT

Mohammad Khazaei, Mohammad Saeed Bahramy, Natarajan Sathiyamoorthy Venkataramanan et al.
Our first-principles calculations show that if the hydrogen atoms on one of the faces of a graphane sheet (prehydrogenated graphene) are substituted with Li atoms, the resulting monolayer attains a good hydrogen storage capacity of around 3.8 wt % close to the revised Department of Energy (DOE) targ ... [J. Appl. Phys. 106, 094303 (2009)] published Fri Nov 6, 2009.

Two-dimensional GaAs/AlGaAs superlattice structures for solar cell applications: Ultimate efficiency estimation

Fri, 06 Nov 2009 18:18:04 GMT

Jaroslaw W. Klos and Maciej Krawczyk
We calculate the band structure of a two-dimensional GaAs/AlGaAs superlattice and estimate the ultimate efficiency of solar cells using this type of structure for solar energy conversion. The superlattice under consideration consists of gallium arsenide rods forming a square lattice and embedded in ... [J. Appl. Phys. 106, 093703 (2009)] published Fri Nov 6, 2009.

Optimization of photonics for corrugated thin-film solar cells

Fri, 06 Nov 2009 18:18:00 GMT

Olivier Deparis, Jean Pol Vigneron, Otto Agustsson et al.
The amount of solar energy reaching the active (photovoltaic) layer in a thin-film solar cell can be increased by reducing the Fresnel reflection losses at the interfaces. By using corrugated interfaces (at the wavelength scale), adiabatic propagation of the electromagnetic radiation is achieved ove ... [J. Appl. Phys. 106, 094505 (2009)] published Fri Nov 6, 2009.

Hybrid organic/inorganic nanocomposite as a quasi-one-dimensional semiconductor under ambient conditions

Mon, 02 Nov 2009 20:42:09 GMT

P. Suresh Kumar, Sandeep Kumar, and V. Lakshminarayanan
We describe here a novel hybrid organic/inorganic nanocomposite of hexahexyloxytriphenylene (HAT6) which is a columnar discotic liquid crystal and gold tetrachloride, an inorganic dopant, showing enhanced dc and ac electrical conductivity by several orders of magnitude at ambient conditions vis-a-vi ... [J. Appl. Phys. 106, 093701 (2009)] published Mon Nov 2, 2009.

Enhanced hydrogen adsorption in boron substituted carbon nanospaces

Fri, 23 Oct 2009 17:03:49 GMT

L. Firlej, Sz. Roszak, B. Kuchta et al.
Activated carbons are one of promising groups of materials for reversible storage of hydrogen by physisorption. However, the heat of hydrogen adsorption in such materials is relatively low, in the range of about 48 kJ/mol, which limits the total amount of hydrogen adsorbed at P=100 bar to ~2 wt % ... [J. Chem. Phys. 131, 164702 (2009)] published Fri Oct 23, 2009.

Three-dimensional structure of the buffer/absorber interface in CdS/CuGaSe based thin film solar cells

Tue, 27 Oct 2009 20:26:18 GMT

M. Rusu, M. Bar, S. Lehmann et al.
The chemical structure of the CdS/CuGaSe chalcopyrite solar cell buffer/absorber interface is investigated by combining element depth profiling using elastic recoil detection analysis and surface-near bulk sensitive x-ray emission spectroscopy. Significant Cd and S concentrations (>=0.1 at. %) are ... [Appl. Phys. Lett. 95, 173502 (2009)] published Tue Oct 27, 2009.

On the hydrogen storage capacity of carbon nanotube bundles

Thu, 22 Oct 2009 18:16:25 GMT

Andre R. Muniz, M. Meyyappan, and Dimitrios Maroudas
An analytical model is presented to describe the effect of carbon nanotube (CNT) swelling upon hydrogenation on the hydrogen storage capacity of single-walled CNT bundles; the model is properly parameterized using atomistic calculations for the relationship between CNT swelling and the degree of hyd ... [Appl. Phys. Lett. 95, 163111 (2009)] published Thu Oct 22, 2009.

Practical efficiency limits in organic photovoltaic cells: Functional dependence of fill factor and external quantum efficiency

Mon, 19 Oct 2009 18:17:39 GMT

Jonathan D. Servaites, Mark A. Ratner, and Tobin J. Marks
We evaluate practical power conversion efficiency limits (eta) in bulk-heterojunction organic photovoltaic (BHJ OPV) cells and how the field dependence of exciton dissociation affects cell efficiencies. We treat the fill factor limit as a function of the donor-acceptor lowest unoccupied molecular or ... [Appl. Phys. Lett. 95, 163302 (2009)] published Mon Oct 19, 2009.