Charge carrier correlation in the electron-doped t-J model

We study the t-t'-t''-J model with parameters chosen to model an electron-doped high temperature superconductor. The model with one, two and four charge carriers is solved on a 32-site lattice using exact diagonalization. Our results demonstrate that at doping levels up to x=0.125 the model possesses robust antiferromagnetic correlation. When doped with one charge carrier, the ground state has momenta (\pm\pi,0) and (0,\pm\pi). On further doping, charge carriers are unbound and the momentum distribution function can be constructed from that of the single-carrier ground state. The Fermi surface resembles that of small pockets at single charge carrier ground state momenta, which is the expected result in a lightly doped antiferromagnet. This feature persists upon doping up to the largest doping level we achieved. We therefore do not observe the Fermi surface changing shape at doping levels up to 0.125

Physics of the Pseudogap State: Spin-Charge Locking

The properties of the pseudogap phase above Tc of the high-Tc cuprate superconductors are described by showing that the Anderson-Nambu SU(2) spinors of an RVB spin gap 'lock' to those of the electron charge system because of the resulting improvement of kinetic energy. This enormously extends the range of the vortex liquid state in these materials. As a result it is not clear that the spinons are ever truly deconfined. A heuristic description of the electrodynamics of this pseudogap-vortex liquid state is proposed.Comment: Submitted to Phys Rev Letter

Technical Skills for Students of Architecture

Architects employ science in order to understand the structural and environmental performance of their products, and apply technology in order to assemble them. And although the role of the architect has changed/evolved even within recent history, the relationship between engineering science, construction technology and the design of the built environment has been at the core of architectural practice throughout history. 2000 years ago, Marcus Vitruvius Pollio (80-15 BC) commenced The Ten Books on Architecture with a chapter on “The Education of The Architect”, where he states: “The architect should be equipped with knowledge of many branches of study and varied kinds of learning, for it is by this judgement that all work done by the other arts is put to the test”. Vitruvius proceeds to explain and differentiate between practice and theory with the need for an architect to have “a thorough knowledge of both”.1 This paper describes the pedagogic approach of the Technical Studies department at the University of Westminster to the architecture course for degree (B.A.) students. It demonstrates the product of this approach in the form of a small sample of student work over a period of roughly ten years

Axiomatization of Inconsistency Indicators for Pairwise Comparisons

This study proposes revised axioms for defining inconsistency indicators in pairwise comparisons. It is based on the new findings that "PC submatrix cannot have a worse inconsistency indicator than the PC matrix containing it" and that there must be a PC submatrix with the same inconsistency as the given PC matrix. This study also provides better reasoning for the need of normalization. It is a revision of axiomatization by Koczkodaj and Szwarc, 2014 which proposed axioms expressed informally with some deficiencies addressed in this study.Comment: This paper should have been withdrawn by the first author a long time ago. The work has been finished with another researcher, I have been pushed out the projec

K-Electron-Capture-to-Positron-Emission Ratio in the Decays of ^(15)O and ^(19)Ne

The K/β^+ ratio in the decays of ^(19)Ne and ^(15)O have been measured as (9.6 ± 0.3) × 10^(-4) and (10.7 ± 0.6) × 10^(-4), respectively. A gas-flow proportional counter, operating in anticoincidence with the surrounding plastic scintillator, was used. Theoretical K/β^+ ratios for ^(19)Ne and ^(15)O were computed, using exchange-overlap corrections calculated by Vatai and, separately, exchange corrections extrapolated from the results of Bahcall for 14 ≤ Z ≤ 37. The experimental results were found to be in better agreement with Vatai's calculations

Self-deploying boom

Development and operation of metal ribbon which acts like self deploying boom are described. Metal ribbon is retained on two rollers for storage and extends into nonretractable tubular structure upon release. Illustration of equipment is provided

Apparatus for recovering matter adhered to a host surface

The development of an apparatus for removing and recovering matter adhered to a host surface is described. The device consists of a pickup head with an ultrasonic transducer adapted to deliver ultrasonic pressure waves against the material. The ultrasonic waves agitate the material and cause its separation from the surface. A vacuum system recovers the material and delivers it to suitable storage containers

Generator for a space power system Patent

Design and development of electric generator for space power syste

Computer aids and human second reading as interventions in screening mammography: two systematic reviews to compare effects on cancer detection and recall rate

Background: There are two competing methods for improving the accuracy of a radiologist interpreting screening mammograms: computer aids (CAD) or independent second reading. Methods: Bibliographic databases were searched for clinical trials. Meta-analyses estimated impacts of CAD and double reading on odds ratios for cancer detection and recall rates. Sub-group analyses considered double reading with arbitration. Results: Ten studies compared single reading with CAD to single reading. Seventeen compared double to single reading. Double reading increases cancer detection and recall rates. Double reading with arbitration increases detection rate (CI: 1.02-1.15) and decreases recall rate (CI: 0.92-0.96). CAD does not have a significant effect on cancer detection rate (CI: 0.96-1.13) and increases recall rate (95% CI: 1.09-1.12). However, there is considerable heterogeneity in the impact on recall rate in both sets of studies. Conclusion: The evidence that double reading with arbitration enhances screening is stronger than that for single reading with CAD

Theoretical and experimental determination of cell constants of planar-interdigitated electrolyte conductivity sensors

In this paper, an analytical expression is presented for the cell constant of planar-interdigitated electrodes used as electrolyte conductivity sensors. The result of this expression is compared with results of measurement carried out with several differently shaped planar probes provided with a thin Ta2O5 insulating film, showing good agreement. More than 10 different devices have been fabricated with predicted cell constants ranging from 0.14 to 4.44 cm¿1. The measured cell constants are typically 10¿20% smaller, possibly due to fringing effects