Quantum confined colloidal nanorod heterostructures for solar-to-fuel conversion

2016 ◽  
Vol 45 (14) ◽  
pp. 3781-3810 ◽  
Author(s):  
Kaifeng Wu ◽  
Tianquan Lian
Keyword(s):  
Quantum Confinement ◽  
Carrier Transport ◽  
Axial Direction ◽  
Fuel Conversion ◽  
Long Distance ◽  
One Dimensional ◽  
Quantum Confined

Colloidal one-dimensional (1D) semiconductor nanorods (NRs) offer the opportunity to simultaneously maintain quantum confinement in radial dimensions for tunable light absorptions and bulk like carrier transport in the axial direction for long-distance charge separations.

2D Self-assembly and Electronic Characterization of Oxygen-Boron-Oxygen-Doped Chiral Graphene Nanoribbons

2021 ◽  
Author(s):  
Lei Jin ◽  
Nerea Bilbao ◽  
Yang Lv ◽  
Xiao-Ye Wang ◽  
Soltani Paniz ◽  
...  
Keyword(s):  
Edge Effects ◽  
Self Assembly ◽  
Quantum Confinement ◽  
Graphene Nanoribbons ◽  
One Dimensional ◽  
The Past ◽  
Different Types

Graphene nanoribbons (GNRs), quasi-one-dimensional strips of graphene, exhibit a nonzero bandgap due to quantum confinement and edge effects. In the past decade, different types of GNRs with atomically precise structures...

Performance Modeling of Desiccant Wheels: 1 — Model Development

2008 ◽  
Author(s):  
Chaoqin Zhai ◽  
David H. Archer ◽  
John C. Fischer
Keyword(s):  
Model Development ◽  
Axial Direction ◽  
Performance Model ◽  
Design Parameters ◽  
Residual Water ◽  
One Dimensional ◽  
Operating Variables ◽  
Steady State Operation ◽  
Rotary Speed ◽  
The Impact

This paper presents the development of an equation based model to simulate the combined heat and mass transfer in the desiccant wheels. The performance model is one dimensional in the axial direction. It applies a lumped formulation in the thickness direction of the desiccant and the substrate. The boundary conditions of this problem represent the inlet outside/process and building exhaust/regeneration air conditions as well as the adiabatic condition of the two ends of the desiccant composite. The solutions of this model are iterated until the wheel reaches periodic steady state operation. The modeling results are obtained as the changes of the outside/process and building exhaust/regeneration air conditions along the wheel depth and the wheel rotation. This performance model relates the wheel’s design parameters, such as the wheel dimension, the channel size and the desiccant properties, and the wheel’s operating variables, such as the rotary speed and the regeneration air flowrate, to its operating performance. The impact of some practical issues, such as wheel purge, residual water in the desiccant and the wheel supporting structure, on the wheel performance has also been investigated.

Theoretical Modeling of Thermoelectricity in Bi Nanowires

1998 ◽  
Vol 545 ◽  
Author(s):  
X. Sun ◽  
Z. Zhang ◽  
G. Dresselhaus ◽  
M. S. Dresselhaus ◽  
J. Y. Ying ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Theoretical Model ◽  
Quantum Confinement ◽  
Figure Of Merit ◽  
Wire Diameter ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Crystalline Orientation ◽  
One Dimensional ◽  
Bismuth Nanowires

AbstractBismuth as a semimetal is not a good thermoelectric material in bulk form because of the approximate cancellation between the electron and hole contributions. However, quantum confinement can be introduced by making Bi nanowires to move the lowest conduction subband edge up and the highest valence subband edge down to get a one-dimensional (1D) semiconductor at some critical wire diameter dc. A theoretical model based on the basic band structure of bulk Bi is developed to predict the dependence of these quantities on wire diameter and on the crystalline orientation of the bismuth nanowires. Numerical modeling is performed for trigonal, binary and bisectrix crystal orientations. By carefully tailoring the Bi wire diameter and carrier concentration, substantial enhancement in the thermoelectric figure of merit is expected for small nanowire diameters.

An Integrated Engineering Model for Prediction of Strain Demands in Pipelines Subject to Frost Heave

2006 ◽  
Author(s):  
Joe Zhou ◽  
Gordon Craig ◽  
Beez Hazen ◽  
James D. Hart
Keyword(s):  
Life Cycle Cost ◽  
Cost Optimization ◽  
Axial Direction ◽  
Gas Pipeline ◽  
Frost Heave ◽  
Engineering Model ◽  
Long Distance ◽  
Demand Prediction ◽  
Discontinuous Permafrost ◽  
Differential Frost Heave

Long distance pipelines are actively pursued by the industry to transport natural gas from remote arctic regions to markets. A chilled gas pipeline is one of the options to minimize the environmental impact resulting from operation of such pipelines. When a chilled gas pipeline crosses discontinuous permafrost areas, differential frost heave can occur. The result is pipe being subjected to potentially high strains, primarily in the axial direction. Reliable prediction of strain demands is one of the key components for a strain-based design process and it is essential for both ensuring pipeline integrity and facilitating life-cycle cost optimization for the design and maintenance of pipelines. The prediction of strain demands resulting from frost heave of chilled gas pipelines involves three fundamental engineering analysis processes. They are gas hydraulic analysis, geothermal analysis and pipeline structural analysis. Not only are these three processes complex, they are also mutually interdependent. To reliably predict strain demands and fully capture the interactions among these processes, TransCanada Pipelines Ltd. (TransCanada) and its partners developed an integrated engineering model on the basis of three well established programs for the three individual engineering processes. This paper will briefly review the integrated model for strain demand prediction.

scholarly journals One-dimensional confinement and width-dependent bandgap formation in epitaxial graphene nanoribbons

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hrag Karakachian ◽  
T. T. Nhung Nguyen ◽  
Johannes Aprojanz ◽  
Alexei A. Zakharov ◽  
Rositsa Yakimova ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Quantum Confinement ◽  
Field Effect Transistors ◽  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Pristine Graphene ◽  
One Dimensional ◽  
Experimental Findings

AbstractThe ability to define an off state in logic electronics is the key ingredient that is impossible to fulfill using a conventional pristine graphene layer, due to the absence of an electronic bandgap. For years, this property has been the missing element for incorporating graphene into next-generation field effect transistors. In this work, we grow high-quality armchair graphene nanoribbons on the sidewalls of 6H-SiC mesa structures. Angle-resolved photoelectron spectroscopy (ARPES) and scanning tunneling spectroscopy measurements reveal the development of a width-dependent semiconducting gap driven by quantum confinement effects. Furthermore, ARPES demonstrates an ideal one-dimensional electronic behavior that is realized in a graphene-based environment, consisting of well-resolved subbands, dispersing and non-dispersing along and across the ribbons respectively. Our experimental findings, coupled with theoretical tight-binding calculations, set the grounds for a deeper exploration of quantum confinement phenomena and may open intriguing avenues for new low-power electronics.

Electron Microscopy of Mesoscale Arrays of Quantum-Confined CdS Nanoparticles Formed on DNA Templates

1996 ◽  
Vol 452 ◽  
Author(s):  
Russell F. Pinizzotto ◽  
Young G. Rho ◽  
Yandong Chen ◽  
Robert M. Pirtle ◽  
Irma L. Pirtle ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Confinement ◽  
Cds Nanoparticles ◽  
Dna Templates ◽  
Quantum Confinement Effects ◽  
Transmission Electron ◽  
Quantum Confined ◽  
Processing Techniques ◽  
State Processing

AbstractThis paper describes the fabrication method and initial characterization of self-assembled mesoscale arrays of quantum-confined CdS nanoparticles using DNA as a template for the overall shape. Three DNAs were used: the circular and linear forms of the plasmid pUCLeu4, and circular φ×174 RF II. In all three cases, the mesoscale lengths are consistent with the A-form of DNA. The structural signatures and crystallography were confirmed using conventional and high resolution transmission electron microscopy, and electron diffraction. Optical spectroscopy demonstrated that the particles display quantum-confinement effects. This research is a fundamental demonstration of the power of combining biochemical and solid-state processing techniques.

One-dimensional model for axial thermal error in a micro high-speed spindle

2017 ◽  
Vol 232 (20) ◽  
pp. 3781-3793
Author(s):  
Van-The Than ◽  
Jin H Huang ◽  
Thi-Thao Ngo ◽  
Chi-Chang Wang
Keyword(s):  
High Speed ◽  
Thermal Error ◽  
Axial Direction ◽  
Transfer Model ◽  
Measured Temperature ◽  
One Dimensional ◽  
Thermal Errors ◽  
Short Processing Time ◽  
Thermal Error Model ◽  
Effective Integration

This article proposes a robust and accurate axial thermal error model for a micro high-speed spindle. With measured temperatures, an inverse method is applied to obtain the heat source and temperature field in the spindle for demonstrating that there exists a uniform temperature distribution along the axial direction within the motor range. Hence, a simple one-dimensional heat transfer model is established to acquire the temperature and resulting thermal errors using only one measured temperature on housing surface. Jumped displacement when the spindle starts and stops and the nonlinear deformation on the bearings are satisfactorily treated in the model. The results show that the estimated thermal errors agree with the measured data for both constant and various speeds. In addition, the results reveal that spindle speed significantly affects the maximum thermal error. A short processing time is an advantage of the proposed method. The model promises effective integration in machine tools for compensating thermal errors.

Sign in / Sign up

Export Citation Format

Share Document