1,168 research outputs found
The law of action and reaction for the effective force in a nonequilibrium colloidal system
We study a nonequilibrium Langevin many-body system containing two 'test'
particles and many 'background' particles. The test particles are spatially
confined by a harmonic potential, and the background particles are driven by an
external driving force. Employing numerical simulations of the model, we
formulate an effective description of the two test particles in a
nonequilibrium steady state. In particular, we investigate several different
definitions of the effective force acting between the test particles. We find
that the law of action and reaction does not hold for the total mechanical
force exerted by the background particles, but that it does hold for the
thermodynamic force defined operationally on the basis of an idea used to
extend the first law of thermodynamics to nonequilibrium steady states.Comment: 13 page
The order-disorder transition in colloidal suspensions under shear flow
We study the order-disorder transition in colloidal suspensions under shear
flow by performing Brownian dynamics simulations. We characterize the
transition in terms of a statistical property of time-dependent maximum value
of the structure factor. We find that its power spectrum exhibits the power-law
behaviour only in the ordered phase. The power-law exponent is approximately -2
at frequencies greater than the magnitude of the shear rate, while the power
spectrum exhibits the -type fluctuations in the lower frequency regime.Comment: 11 pages, 10 figures, v.2: We have made some small improvements on
presentation
Learning from the Experiences of Collegiate Athletes Living through a Season- or Career-Ending Injury
An athlete’s identity is often related to the goals of their team and their ability to achieve excellence in sport. A threat to an athlete’s identity is a season- or career-ending injury. Athletes can respond to season- or career-ending injuries in ways detrimental to their psychosocial well-being (Ivarsson, Tranaeus, Johnson, & Stenling 2017). This study built upon existing knowledge by seeking to better understand the lived experiences of Division I collegiate athletes who experienced a season- or career-ending injury. There is a need for ongoing recommendations for helping athletes process their injuries. Researchers used a descriptive phenomenological approach. Researchers interviewed ten college athletes who experienced a season- or career-ending injury. Themes included: (1) physical and emotional stress, (2) resistance to resiliency, (3) importance of relationships with others, and (4) appreciation and cultivation for new possibilities outside of sport. This research provided insight for behavioral health professionals on injury response. This included the need for Posttraumatic Growth responses such as (1) building strong support pre- and post-injury, (2) recognizing healthy coping mechanisms, (3) cultivating new identities for athletes, (4) helping an athlete with identity loss, (5) helping athletes recognize new possibilities post-injury, and (6) helping an athlete maintain an appreciation for life
Spin transport in ferromagnet-InSb nanowire quantum devices
Signatures of Majorana zero modes (MZMs), which are the building blocks for
fault-tolerant topological quantum computing, have been observed in
semiconductor nanowires (NW) with strong spin-orbital-interaction (SOI), such
as InSb and InAs NWs with proximity-induced superconductivity. Realizing
topological superconductivity and MZMs in this most widely-studied platform
also requires eliminating spin degeneracy, which is realized by applying a
magnetic field to induce a helical gap. However, the applied field can
adversely impact the induced superconducting state in the NWs and also places
geometric restrictions on the device, which can affect scaling of future
MZM-based quantum registers. These challenges could be circumvented by
integrating magnetic elements with the NWs. With this motivation, in this work
we report the first experimental investigation of spin transport across InSb
NWs, which are enabled by devices with ferromagnetic (FM) contacts. We observe
signatures of spin polarization and spin-dependent transport in the
quasi-one-dimensional ballistic regime. Moreover, we show that electrostatic
gating tunes the observed magnetic signal and also reveals a transport regime
where the device acts as a spin filter. These results open an avenue towards
developing MZM devices in which spin degeneracy is lifted locally, without the
need of an applied magnetic field. They also provide a path for realizing
spin-based devices that leverage spin-orbital states in quantum wires.Comment: 30 pages, 12 figure
The Impact of Gombe Micro Finance Bank on Profitability and Income of Agricultural Businesses in Gombe Metropolis, Gombe State, Nigeria
The study examined the impact of Gombe micro finance bank on profitability and income of agricultural businesses in Gombe metropolis, Gombe State , Nigeria. Multi stage sampling technique was used in selecting 105 beneficiaries of the bank comprising of fifty (50) microprocessors, thirty (30) vegetables sellers and twenty five (25) fruits sellers. The data were collected using structured questionnaire. Secondary data were also collected from the bank. The data were e analyzed using descriptive statistics, T-test, Gross margin analysis and multiple regression models. The results of the analysis revealed that Women constituted 49% of the beneficiaries of the bank loans since its inception in 2008. There was significant difference in income of the respondents before and after benefiting from the loan. The gross margin analysis revealed that the respondents had an average gross margin of 2096.70 NGN.The major problems encountered by the respondents while accessing the loan were; compulsory saving with the bank, high interest rate, loan maturity period and frequency of visits for the loan recovery. Keywords: Impact, Gombe Micro finance bank, Profitability, Income, Agricultural businesse
Slow decay of dynamical correlation functions for nonequilibrium quantum states
A property of dynamical correlation functions for nonequilibrium states is
discussed. We consider arbitrary dimensional quantum spin systems with local
interaction and translationally invariant states with nonvanishing current over
them. A correlation function between local charge and local Hamiltonian at
different spacetime points is shown to exhibit slow decay.Comment: typos correcte
Exact transformation of a Langevin equation to a fluctuating response equation
We demonstrate that a Langevin equation that describes the motion of a
Brownian particle under non-equilibrium conditions can be exactly transformed
to a special equation that explicitly exhibits the response of the velocity to
a time dependent perturbation. This transformation is constructed on the basis
of an operator formulation originally used in nonlinear perturbation theory for
differential equations by extending it to stochastic analysis. We find that the
obtained expression is useful for the calculation of fundamental quantities of
the system, and that it provides a physical basis for the decomposition of the
forces in the Langevin description into effective driving, dissipative, and
random forces in a large-scale description.Comment: 14 pages, to appear in J. Phys. A: Math. Ge
Temperature dependent photoluminescence in oxygen ion implanted and rapid thermally annealed ZnO/ZnMgO multiple quantum wells
The authors investigate the effect of oxygen implantation and rapid thermal annealing in ZnO∕ZnMgOmultiple quantum wells using photoluminescence. A blueshift in the photoluminescence is observed in the implanted samples. For a low implantation dose, a significant increase of activation energy and a slight increase of the photoluminescence efficiency are observed. This is attributed to the suppression of the point defect complexes and transformation between defect structures by implantation and subsequent rapid thermal annealing. A high dose of implantation leads to lattice damage and agglomeration of defects leading to large defect clusters, which result to an increase in nonradiative recombination.The authors gratefully acknowledge the Australian Research
Council for financial support and Swinburne University
of Technology for Strategic Initiative funding. One of
the authors X.W. acknowledges partial financial support of
the Chinese National Natural Science Foundation
10364004 and the Yunnan Natural Science Foundation
2003E0013M
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