Results 41 to 50 of about 25,975 (270)

Periodicity in Rank 2 Graph Algebras

, 2007
Kumjian and Pask introduced an aperiodicity condition for higher rank graphs. We present a detailed analysis of when this occurs in certain rank 2 graphs. When the algebra is aperiodic, we give another proof of the simplicity of $\ca(\Fth)$. The periodic
Cuntz, Davidson, Dilian Yang, Farthing, Kenneth R. Davidson, Kribs, Kumjian, Pask, Power, Raeburn, Raeburn, Robertson, Robertson, Sims   +13 more
core   +3 more sources

Exploring the diffeomorphism invariant Hilbert space of a scalar field [PDF]

, 2006
As a toy model for the implementation of the diffeomorphism constraint, the interpretation of the resulting states, and the treatment of ordering ambiguities in loop quantum gravity, we consider the Hilbert space of spatially diffeomorphism invariant ...
Ashtekar A, Ashtekar A, Bojowald M, Han M, Hanno Sahlmann, Kaminski W, Kaminski W, Starodubtsev A, Thiemann T, Thiemann T, Thiemann T, Thiemann T, Thiemann T   +12 more
core   +2 more sources

The HVDC commutation failure mechanism impacted by harmonics and its suppression method

Frontiers in Energy Research
Harmonics are an important cause of voltage distortion, and voltage reduction and voltage distortion are the main causes of commutation failure. But most of the current research studies on commutation failure are based on the drop in fundamental voltage ...
Guojiang Zhang, Jingbo Zhao, Yongyong Jia, Qian Zhou, Ke Xu   +4 more
doaj   +1 more source

From Heisenberg matrix mechanics to EBK quantization: theory and first applications

, 1996
Despite the seminal connection between classical multiply-periodic motion and Heisenberg matrix mechanics and the massive amount of work done on the associated problem of semiclassical (EBK) quantization of bound states, we show that there are ...
A. Einstein, A. Garcia-Ayllon, A. K. Kerman, A. Klein, A. Klein, A. Klein, Abraham Klein, C. C. Martens, C. C. Martens, C. C. Martens, C. Jaffé, C. Jaffé, C. Jaffé, C. T. Li, C. T. Li, Ching-Teh Li, D. W. Noid, D. W. Noid, E. A. Solov'ev, F. G. Gustavson, G. Do Dang, G. S. Ezra, H. Hasegawa, I. C. Percival, I. C. Percival, I. C. Percival, I. C. Percival, I. C. Percival, I. C. Percival, I. C. Percival, I. C. Percival, Ivaylo Zlatev, J. B. Keller, J. J. Morehead, J. Müller, L. E. Fried, M. Born, M. Born, M. L. Brillouin, N. De Leon, N. De Leon, R. B. Shirts, R. T. Skodje, R. T. Swimm, S. Chapman, S. M. Colwell, W. Eastes, W. R. Greenberg, W. R. Greenberg, William R. Greenberg   +49 more
core   +1 more source

Schrodinger representation for the polarized Gowdy model [PDF]

, 2006
The polarized ${\bf T}^3$ Gowdy model is, in a standard gauge, characterized by a point particle degree of freedom and a scalar field degree of freedom obeying a linear field equation on ${\bf R}\times{\bf S}^1$.
Torre, C. G.
core   +4 more sources

The Future of Hydrogen‐Powered Aviation: Technologies, Challenges, and a Strategic Roadmap for Sustainable Decarbonization

Advanced Energy and Sustainability Research, EarlyView.
Hydrogen‐powered aviation offers a transformative pathway to zero‐emission flight by eliminating in‐flight CO2 emissions. Key considerations include propulsion systems (fuel cells and hydrogen combustion), cryogenic storage and insulation challenges, infrastructure and cost barriers, and supply‐chain constraints.
Mubasshira, Md Mahbubur Rahman, Karib Hassan Khan, Md Nizam Uddin, Dewan Hafiz Nabil   +4 more
wiley   +1 more source

A pipeline crisis or a sustainability crisis? Local and national succession planning for headteachers in England

British Educational Research Journal, EarlyView.
Abstract Recruiting and retaining school leaders is a challenge in many systems worldwide. Previous research has identified three distinct ways in which succession planning can be conceptualised and approached: a ‘pipeline’ approach seeks to match supply and demand for the posts that need filling; a ‘pool’ strategy involves proactively identifying and ...
Toby Greany, Pat Thomson, Tom Perry, Mike Collins   +3 more
wiley   +1 more source

Charge-Spin Separation in 2D Fermi Systems: Singular Interactions as Modified Commutators, and Solution of 2D Hubbard Model in Bosonized Approximation [PDF]

, 1995
The general 2-dimensional fermion system with repulsive interactions (typified by the Hubbard Model) is bosonized, taking into account the finite on-shell forward scattering phase shift derived in earlier papers.
A. A. Abrikosov, A. El Azrak, A. Houghton, C. di Castro, D. G. Clarke, D. Khveshchenko, D. Khveshchenko, F. D. M. Haldane, F. D. M. Haldane, G. Engelbrecht, G. Engelbrecht, G. Engelbrecht, H. Fukuyama, H. Fukuyama, P. C. E. Stamp, P. W. Anderson, P. W. Anderson, P. W. Anderson   +17 more
core   +3 more sources

Does Accounting Scope 3 Emissions Improve Sustainable Business Outcomes? Evidence From the S&P 500 Technology Companies

Business Strategy and the Environment, EarlyView.
ABSTRACT Corporate sustainability efforts increasingly emphasize Scope 3 emissions due to their substantial share of total corporate carbon footprints. However, reporting these emissions remains inconsistent, limiting transparency and comparability across firms.
Nuri C. Onat, Murat Kucukvar, Tadesse Wakjira, Amr Elalfy, Adeeb A. Kutty   +4 more
wiley   +1 more source

A review on evaluation and improvement methods for commutation failure resistance ability in multi-infeed direct current system

电力工程技术
The evaluation and improvement methods for commutation failure resistance ability in multi-infeed direct current (MIDC) system are of great significance for testing commutation failure characteristics, addressing assessment challenges, and applying ...
Yechun XIN, Taoyu HUANG, Tuo WANG, Yupeng HE, Xiaoluo GAN, Guoqing LI   +5 more
doaj   +1 more source