3,862 research outputs found
Thermoelectric spin voltage in graphene
In recent years, new spin-dependent thermal effects have been discovered in
ferromagnets, stimulating a growing interest in spin caloritronics, a field
that exploits the interaction between spin and heat currents. Amongst the most
intriguing phenomena is the spin Seebeck effect, in which a thermal gradient
gives rise to spin currents that are detected through the inverse spin Hall
effect. Non-magnetic materials such as graphene are also relevant for spin
caloritronics, thanks to efficient spin transport, energy-dependent carrier
mobility and unique density of states. Here, we propose and demonstrate that a
carrier thermal gradient in a graphene lateral spin valve can lead to a large
increase of the spin voltage near to the graphene charge neutrality point. Such
an increase results from a thermoelectric spin voltage, which is analogous to
the voltage in a thermocouple and that can be enhanced by the presence of hot
carriers generated by an applied current. These results could prove crucial to
drive graphene spintronic devices and, in particular, to sustain pure spin
signals with thermal gradients and to tune the remote spin accumulation by
varying the spin-injection bias
Magnetic Charge in a Nonassociative Field Theory
The violation of the Jacobi identity by the presence of magnetic charge is
accomodated by using an explicitly nonassociative theory of octonionic fields.
It is found that the dynamics of this theory is simplified if the Lagrangian
contains only dyonic charges, but certain problems in the constrained
quantisation remain. The extension of these concepts to string theory may
however resolve these difficulties.Comment: 10 pages, REVTeX, no figure
PRINT.ed #4
PRINTed es proposa com una fira de petit format dedicada a l’àmbit de les publicacions singulars, entenent com a tals tota mena de treballs d’edició on s’especula al voltant de la idea de llibre en el seu sentit més ampli. L’objectiu és oferir als participants un esdeveniment i un context interdisciplinar, des d’on comunicar-se mútuament i amb el públic, donant alhora sortida, de manera professional, al producte de les especulacions generades de portes endins. Establir ponts i provocar encreuaments i encontres ens enriqueix i genera un teixit d’interessos comuns que
s’ha d’expandir a través d’aquests contactes, més enllà del centres de producció. PRINTed es genera des d’un entorn acadèmic, amb la pretensió de generar vincles entre diversos centres educatius d’arreu del món on es desenvolupin activitats formatives relacionades amb la impressió, l’edició i el disseny. També persegueix generar
continguts i activar dinàmiques productives i en aquest sentit proposa activitats que poden anar des de la marató de impressions realitzada en paral·lel a la segona edició (24 hours printing people) als tallers conduïts per artistes convidats o centres de producció.PRINTed is proposed as a small-format fair dedicated to the field of singular publications, understanding this to
include all kinds of editions that contemplate the idea of the book in the broadest possible sense. The aim is to offer participants an event and an interdisciplinary context, where participants can communicate with each other as well as with a broader public. An arena for the publications generated through experimentation and research within the confines of the studio to be disseminated further afield, in the professional setting of a book fair. The hope is to build bridges, to provoke enriching encounters and exchanges, and to generate a network
of shared interests that will expand through the contacts established in these fairs for the development of future projects. PRINTed is generated from within an educational environment, with the aim of generating links between different centres from around the world where teaching and research is undertaken in the fields of printmaking, editions, and design. It also aims to generate content and activate dynamics for the production of prints and in this sense proposes activities that go from the 24 hours print marathon carried out during the second edition of PRINTed (24 hours printing people) to workshops led by guest artists and visiting production centres
The Importance of Self-Generation of Electricity through Controlled Recycling: a Case Study in West Sub-Saharan African Regions
Controlled recycling of different materials, typical to household appliances, from the landfills located in developing countries in West Sub-Saharan Africa and their subsequent reuse can favour the social, economic and environmental sustainability of the involved regions. This process reduces the unhealthy conditions associated with landfills and the inadequate use of fuels, and it also solves certain deficits in the population. As a continuation of previous studies, this article proposes a practical example of manufacture through the controlled reuse of an asynchronous wind-powered electricity generation system, analysing the benefits and possibilities detected, especially in domestic self-generation and in the reduction of CO2 emissions into the atmosphere. In summary, the topic is the manufacture of an energy generating system using recycled material for domestic use. In this way, the associated self-generation of electricity can supply or reduce the energy demand of a large part of the population in these regions that do not have electricity supply; for example, for a household in Nigeria, it would save between 15% and 75% of the electricity supply. Providing electricity supply also prevents deforestation in regions that use natural biomass as an alternative energy source, an issue that has a global impact on CO2 emissions into the atmosphere
Patient-reported outcomes of periacetabular osteotomy from the prospective ANCHOR cohort study
BACKGROUND: Current literature describing the periacetabular osteotomy (PAO) is mostly limited to retrospective case series. Larger, prospective cohort studies are needed to provide better clinical evidence regarding this procedure. The goals of the current study were to (1) report minimum 2-year patient-reported outcomes (pain, hip function, activity, overall health, and quality of life), (2) investigate preoperative clinical and disease characteristics as predictors of clinical outcomes, and (3) report the rate of early failures and reoperations in patients undergoing contemporary PAO surgery. METHODS: A large, prospective, multicenter cohort of PAO procedures was established, and outcomes at a minimum of 2 years were analyzed. A total of 391 hips were included for analysis (79% of the patients were female, and the average patient age was 25.4 years). Patient-reported outcomes, conversion to total hip replacement, reoperations, and major complications were documented. Variables with a p value of ≤0.10 in the univariate linear regressions were included in the multivariate linear regression. The backward stepwise selection method was used to determine the final risk factors of clinical outcomes. RESULTS: Clinical outcome analysis demonstrated major clinically important improvements in pain, function, quality of life, overall health, and activity level. Increasing age and a body mass index status of overweight or obese were predictive of improved results for certain outcome metrics. Male sex and mild acetabular dysplasia were predictive of lesser improvements in certain outcome measures. Three (0.8%) of the hips underwent early conversion to total hip arthroplasty, 12 (3%) required reoperation, and 26 (7%) experienced a major complication. CONCLUSIONS: This large, prospective cohort study demonstrated the clinical success of contemporary PAO surgery for the treatment of symptomatic acetabular dysplasia. Patient and disease characteristics demonstrated predictive value that should be considered in surgical decision-making. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence
Physiological and behavioral effects of animal-assisted interventions for therapy dogs in pediatric oncology settings
Over the past two decades, animal-assisted interventions (AAIs), defined as the purposeful incorporation of specially trained animals in services to improve human health, have become increasingly popular in clinical settings. However, to date, there have been few rigorously-designed studies aimed at examining the impact of AAIs on therapy animals, despite a notable potential for stress. The current study measured physiological and behavioral stress indicators in therapy dogs who participated in AAI sessions in pediatric oncology settings, while also examining the psychosocial effects for patients and their parents. This manuscript describes the study’s canine stress findings. Methods: A total of 26 therapy dog-handler teams were paired with newly diagnosed children with cancer at five children’s hospitals in the United States. These teams provided regular AAI visits to the child and his/her parent(s) for a period of four months. The teams completed a demographic form, the Canine Behavioral Assessment & Research Questionnaire (C-BARQ), and a self-report survey to document the types of activities that occurred during each session. Canine saliva was also collected at five baseline time points and 20 minutes after the start of study sessions for cortisol analysis, and all study sessions were video recorded to document the dog’s behavior via an ethogram measure. Results: Data showed no significant differences in salivary cortisol levels between baseline (0.51µg/dL) and AAI sessions (0.44µg/dL), p = 0.757. Higher salivary cortisol was significantly associated with a higher number of stress behaviors per session (p = 0.039). There was a significant relationship between stress and affiliative session behaviors (pConclusions:Results show that therapy dogs did not have significantly increased physiological stress responses, nor did they exhibit significantly more stress-related behaviors than affiliative-related behaviors, while participating in AAIs in pediatric oncology settings. The significant relationship between canine cortisol and behavior, thus strengthening the argument for the use of cortisol in canine well-being research. This study discusses the importance of further investigation to confirm these findings, which may lead to enhanced canine involvement in hospital settings
Previous failed hip arthroscopy negatively impacts early patient-reported outcomes of the periacetabular osteotomy: An ANCHOR matched cohort study
Determination of the spin-lifetime anisotropy in graphene using oblique spin precession
We determine the spin-lifetime anisotropy of spin-polarized carriers in graphene. In contrast to prior approaches, our method does not require large out-of-plane magnetic fields and thus it is reliable for both low-and high-carrier densities. We first determine the in-plane spin lifetime by conventional spin precession measurements with magnetic fields perpendicular to the graphene plane. Then, to evaluate the out-of-plane spin lifetime, we implement spin precession measurements under oblique magnetic fields that generate an out-of-plane spin population. We find that the spin-lifetime anisotropy of graphene on silicon oxide is independent of carrier density and temperature down to 150 K, and much weaker than previously reported. Indeed, within the experimental uncertainty, the spin relaxation is isotropic. Altogether with the gate dependence of the spin lifetime, this indicates that the spin relaxation is driven by magnetic impurities or random spin-orbit or gauge fields
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