8,205 research outputs found
Magnification of spin Hall effect in bilayer electron gas
Spin transport properties of a coupled bilayer electron gas with Rashba
spin-orbit coupling are studied. The definition of the spin currents in each
layer as well as the corresponding continuity-like equations in the bilayer
system are given. The curves of the spin Hall conductivities obtained in each
layer exhibit sharp cusps around a particular value of the tunnelling strength
and the conductivities undergo sign changes across this point. Our
investigation on the impurity effect manifests that an arbitrarily small
concentration of nonmagnetic impurities does not suppress the spin Hall
conductivity to zero in the bilayer system. Based on these features, an
experimental scheme is suggested to detect a magnification of the spin Hall
effect.Comment: Revtex 10 pages, 4 figures; largely extended versio
Effect of structural relaxation on the electronic structure of graphene on hexagonal boron nitride
We performed calculations of electronic, optical and transport properties of
graphene on hBN with realistic moir\'e patterns. The latter are produced by
structural relaxation using a fully atomistic model. This relaxation turns out
to be crucially important for electronic properties. We describe experimentally
observed features such as additional Dirac points and the "Hofstadter
butterfly" structure of energy levels in a magnetic field. We find that the
electronic structure is sensitive to many-body renormalization of the local
energy gap.Comment: 5 pages, 6 figures. Supplementary material is available at
http://www.theorphys.science.ru.nl/people/yuan/attachments/sm_hbn.pd
Effect of structural relaxation on the electronic structure of graphene on hexagonal boron nitride
We performed calculations of electronic, optical and transport properties of
graphene on hBN with realistic moir\'e patterns. The latter are produced by
structural relaxation using a fully atomistic model. This relaxation turns out
to be crucially important for electronic properties. We describe experimentally
observed features such as additional Dirac points and the "Hofstadter
butterfly" structure of energy levels in a magnetic field. We find that the
electronic structure is sensitive to many-body renormalization of the local
energy gap.Comment: 5 pages, 6 figures. Supplementary material is available at
http://www.theorphys.science.ru.nl/people/yuan/attachments/sm_hbn.pd
Them and Us?: Exploring the collaboration between Industrial Designers and Engineering Designers
In the global marketplace, it is essential that well-designed products are produced within the shortest possible lead times. Manufacturers must therefore endeavor to utilize best practice for the efficient control and management of new product development. To enhance competitive advantage, industrial design has been increasingly used as a strategic resource in conjunction with collaboration with engineering design. This study discusses the findings of empirical investigations undertaken in 2006 that recorded the nature of interaction between industrial designers and engineering designers in Singapore. The research posed the following questions:
i) How and when do industrial designers and engineering designers work together?
ii) What leads to successful or poor collaboration?
iii) What factors influence collaboration and can they be categorized?
iv) Do representation tools affect collaboration?
v) What are the characteristics for a successful tool for effective collaboration between industrial designers and engineering designers
Standardized propaganda units for war time and peace time China
Thesis (B. Arch)--Massachusetts Institute of Technology, Dept. of Architecture, 1940.Accompanying drawings held by MIT Museum.Includes bibliographical references (leaf [21]).by Ieoh Ming Pei.B.Arc
Understanding spin transport from the motion in SU(2)U(1) fields
Starting from a continuum constituted by charged tops, we formulate the
classical counterpart of a previously obtained covariant continuity-like
equation for the spin current. Such a formulism provides an intuitive picture
to elucidate the non-conservation of the spin current and to interpret the
condition for the emergence of an infinite spin relaxation time. It also
facilitates the discussion on the spin precession in a one-dimensional quantum
wire with Dresselhaus and Rashba spin-orbit couplings. Furthermore, we derive
the diffusion equations for both the charge and spin densities and find that
they couple to each other due to the Zitterbewegung.Comment: 6 pages, 4 figures; this is the extended version of
Xiv:cond-mat/0608303 to publish in PR
24-hour sodium and potassium excretion in the Americas: a systematic review and meta-analysis.
OBJECTIVE: To determine the 24-hour urinary sodium and potassium excretions in the Americas. METHODS: A systematic review and meta-analysis were performed seeking for studies conducted between 1990 and 2021 in adults living in any sovereign state of the Americas in Medline, Embase, Scopus, SciELO, and Lilacs. The search was first run on October 26th, 2020 and was updated on December 15th, 2021. Of 3 941 abstracts reviewed, 74 studies were included from 14 countries, 72 studies reporting urinary sodium (27 387 adults), and 42 studies reporting urinary potassium (19 610 adults) carried out between 1990 and 2020. Data were pooled using a random-effects meta-analysis model. RESULTS: Mean excretion was 157.29 mmol/24h (95% CI, 151.42-163.16) for sodium and 57.69 mmol/24h (95% CI, 53.35-62.03) for potassium. When only women were considered, mean excretion was 135.81 mmol/24h (95% CI, 130.37-141.25) for sodium and 51.73 mmol/24h (95% CI, 48.77-54.70) for potassium. In men, mean excretion was 169.39 mmol/24h (95% CI, 162.14-176.64) for sodium and 62.67 mmol/24h (95% CI, 55.41-69.93) for potassium. Mean sodium excretion was 150.09 mmol/24h (95% CI, 137.87-162.30) in the 1990s and 159.79 mmol/24h (95% CI, 151.63-167.95) in the 2010s. Mean potassium excretion was 58.64 mmol/24h (95% CI, 52.73-64.55) in the 1990s and 56.33 mmol/24/h (95% CI, 48.65-64.00) in the 2010s. CONCLUSIONS: These findings suggest that sodium excretions are almost double the maximum level recommended by the World Health Organization and potassium excretions are 35% lower than the minimum requirement; therefore, major efforts to reduce sodium and to increase potassium intakes should be implemented
Centro académico en Fredonia. Nueva York - EE. UU.
The idea behind Pei & Partners' design for the new buildings on the Fredonia Campus is similar to the idea used in other colleges of the same type.
These buildings are associated spacially and structurally according to certain functional and constructional features which stand out in the already existing buildings, resulting in an arrangement with its own independent personality.El esfuerzo realizado por Pei & Partners al concebir y realizar los nuevos edificios del campus de Fredonia, es similar a los ya realizados en otros colegios del mismo tipo.
Dichos edificios se asocian, especial y estructuralmente, según unas caracterÃsticas funcionales y constructivas que los destacan entre los ya existentes, resultando un conjunto con personalidad propia e independiente
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