Domain-wall depinning assisted by pure spin currents

We study the depinning of domain walls by pure diffusive spin currents in a nonlocal spin valve structure based on two ferromagnetic permalloy elements with copper as the nonmagnetic spin conduit. The injected spin current is absorbed by the second permalloy structure with a domain wall and from the dependence of the wall depinning field on the spin current density we find an efficiency of 6*10^{-14}T/(A/m^2), which is more than an order of magnitude larger than for conventional current induced domain wall motion. Theoretically we reproduce this high efficiency, which arises from the surface torques exerted by the absorbed spin current that lead to efficient depinning.Comment: 11 pages, 3 figures, accepted for publication in Phys. Rev. Let

Towards Inferring Mechanical Lock Combinations using Wrist-Wearables as a Side-Channel

Wrist-wearables such as smartwatches and fitness bands are equipped with a variety of high-precision sensors that support novel contextual and activity-based applications. The presence of a diverse set of on-board sensors, however, also expose an additional attack surface which, if not adequately protected, could be potentially exploited to leak private user information. In this paper, we investigate the feasibility of a new attack that takes advantage of a wrist-wearable's motion sensors to infer input on mechanical devices typically used to secure physical access, for example, combination locks. We outline an inference framework that attempts to infer a lock's unlock combination from the wrist motion captured by a smartwatch's gyroscope sensor, and uses a probabilistic model to produce a ranked list of likely unlock combinations. We conduct a thorough empirical evaluation of the proposed framework by employing unlocking-related motion data collected from human subject participants in a variety of controlled and realistic settings. Evaluation results from these experiments demonstrate that motion data from wrist-wearables can be effectively employed as a side-channel to significantly reduce the unlock combination search-space of commonly found combination locks, thus compromising the physical security provided by these locks

Second harmonic generation in SiC polytypes

LMTO calculations are presented for the frequency dependent second harmonic generation (SHG) in the polytypes 2H, 4H, 6H, 15R and 3C of SiC. All independent tensor components are calculated. The spectral features and the ratios of the 333 to 311 tensorial components are studied as a function of the degree of hexagonality. The relationship to the linear optical response and the underlying band structure are investigated. SHG is suggested to be a sensitive tool for investigating the near band edge interband excitations.Comment: 12 pages, 10 figure

Role of Protein-Protein Interactions in Metabolism: Genetics, Structure, Function

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Dinâmica do nitrogênio em função da aplicação de lodos de esgoto em sistema de plantio direto.

Projeto/Plano de Ação: 01.09.10103-04

Teor de metais pesados na cultura da aveia preta em função da aplicação superficial de resíduos urbanos e industriais, no sistema plantio direto.

Projeto/Plano de Ação: 01.09.10103-04

Chadwick GreenBIM: Advancing Operational Understanding of Historical Buildings with BIM to Support Sustainable Use

Chadwick GreenBIM is an initiative to establish a digital 3D as-built model of UCL’s Chadwick Building including embedded environmental data to gain a greater understanding of its operation with the aim of developing concepts for retrofit and sustainable use. This paper investigates the above by reviewing the state of the art in reality capture to generate a parametric model using laser scanning. It also considers the challenges of managing information for simulation including complex ‘big data’ types (e.g. point clouds). The research in this paper was carried out through an empirical approach to create a data-rich Building Information Model (BIM) under real world conditions. Real world measurements of environmental conditions were used to validate the effectiveness of simulations using commercial off-the-shelf (COTS) software packages. In addition, the practicalities of the integration of such data inside the BIM were investigated. Data capture using the methods described in this paper requires extraordinary effort and is expensive in both time and cost. However, advances in BIM enabling technologies such as Indoor Mobile Mapping (IMM) seek improved savings in data collection. Technological advances will further improve the integration of data capture and extraction of information used by simulation tools. Once complete it is envisaged that the GreenBIM model would be disseminated among a broad community of researchers to investigate various perspectives in a collaborative manner