Current-induced torques in textured Rashba ferromagnets

In systems with small spin-orbit coupling, current-induced torques on the magnetization require inhomogeneous magnetization textures. For large spin-orbit coupling, such torques exist even without gradients in the magnetization direction. Here, we consider current-induced torques in ferromagnetic metals with both Rashba spin-orbit coupling and inhomogeneous magnetization. We first phenomenologically construct all torques that are allowed by the symmetries of the system, to first order in magnetization-direction gradients and electric field. Second, we use a Boltzmann approach to calculate the spin torques that arise to second order in the spin-orbit coupling. We apply our results to current-driven domain walls and find that the domain-wall mobility is strongly affected by torques that result from the interplay between spin-orbit coupling and inhomogeneity of the magnetization texture.Comment: 9 pages, 3 figure

The catalytic oxidation of organic contaminants in a packed bed reactor

The catalytic oxidation of several hydrocarbons was studied over noble metal and metal oxide catalysts. A fast empirical method was developed to determine the minimum operating temperature required to guarantee complete conversion of the hydrocarbon.\ud \ud The influence of the operating parameters such as the inlet concentration and residence time, as well as the chemical character of the component to be oxidized, have been investigated. The results can be described satisfactorily by a simple isothermal, plug flow reactor model and first-order reaction kinetics. In the case of simultaneous oxidation of different components a significant mixture effect was not observed. The presence of water in the feed did significantly inhibit the oxidation of alkanes.\ud \ud Of the applied catalysts, Pt was the most effective for the combustion of the alkenes, whereas Pd showed a higher activity for the oxidation of alkanes

South African Xylarias Occurring Around Durban, Natal

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Формирование композиционных покрытий никель – бор – азот

The methods of X-ray analysis and electron microscopy have been used to study the structure of nitrogen-ion implanted electrochemical Ni–B coatings with the boron concentration of 8,14 and 20 at %. The implantation is shown to increase coating microhardness from 5,1-5,9 GPa to 10,8-11,7 GPa. The hardness increase of coatings is attributed to decrease of nickel boride particle size and formation of γ-BN

Deficiencies in technical and vocational education and training lecturer involvement qualifications and its implications in the development of work related skills

Technical Vocational Education and Training (TVET) lecturers play an important role in providing a competent workforce that can contribute to the economy in countries worldwide. The critical role played by TVET lecturers requires of them to have appropriate academic qualifications, workplace qualifications and experience, and teaching qualifications. Research has shown that few lecturers have adequate and required academic, workplace and teaching qualifications. The purpose of this study was to determine the deficiencies in TVET lecturer qualifications and how these deficiencies are addressed by management at TVET colleges in South Africa. While a substantial number of lecturers had academic qualifications at the time of investigation, deficiencies were found in TVET lecturers’ workplace qualifications and experience, as well as in their teaching qualifications. Having identified the deficiencies in TVET lecturer's qualifications, recommendations have been made to serve as guidelines in addressing the lack of either academic, teaching or workplace qualifications and experience. 

Maatregelen tegen pikkerij / kannibalisme

Snavelkappen is in de tekst van het Ingrepenbesluit omschreven als 'het verkorten van de onder- en/of bovensnavel'. Ook varianten als 'licht kappen' of 'snavel branden' vallen hier dus onder. Voor de pluimveehouderij betekent dat vooral dat de leghennen-

Model-Based Testing of Internet of Things Protocols

Internet of Things (IoT) is a popular term to describe systems/devices that connect and interact with each other through a network, e.g., the Internet. These devices communicate with each other via a communication protocol, such as Zigbee or Bluetooth Low Energy (BLE), the subject of this paper. Communication protocols are notoriously hard to implement correctly and a large set of test-cases is needed to check for conformance to the standard. Many of us have encountered communication problems in practice, such as random mobile phone disconnects, difficulty obtaining a Bluetooth connection, etc. In this paper, we research the application of industry strength Model-Based Testing (MBT) within the IoT domain. This technique contributes to higher quality specifications and more efficient and more thorough conformance testing. We show how we can model part of the BLE protocol specification using the Axini Modeling Platform (AMP). Based on the model, AMP is then able to automatically test the conformance of a BLE device. With this approach, we found specification flaws in the official BLE specifications as well as conformance errors on a certified BLE system