Effects of Solute and Second-Phase Particles on the Texture of Nd-Containing Mg Alloys

Hot-rolled, binary Mg-Nd alloys with compositions ≥0.095 at. pct undergo the texture weakening phenomenon that has been reported in a number of Mg–rare earth (RE) alloys. However, alloys with compositions ≤0.01 at. pct retain a strong basal texture typical of pure Mg and other Mg alloys. Measurements of intragranular misorientation axes obtained using electron backscatter diffraction (EBSD) show that more dilute alloys contain predominantly basal $ < a > $ < a > dislocations, while richer alloys contain primarily prismatic $ < a > $ < a > dislocations. It is suggested that this change in dislocation content is related to a change in the dynamic recrystallization (DRX) mechanism. Metastable second-phase Mg _x Nd_1–x intermetallic particles are present within the alloys, and an annealing study indicates that the alloys undergoing texture weakening have grain sizes well predicted by classical Zener drag theory. Even though the more dilute alloys also contain second-phase particles, they are not sufficient to induce pinning. The promotion of nonbasal slip and the reduction in grain boundary mobility due to Zener drag are suggested as controlling mechanisms that promote the observed texture weakening phenomena.     

Enhanced hydrophilic polysulfone hollow fiber membranes with addition of iron oxide nanoparticles

Membranes are at the heart of hemodialysis treatment functions to remove excess metabolic waste such as urea. However, membranes made up of pure polymers and hydrophilic polymers such as polyvinylpyrrolidone suffer problems of low flux and bio‐incompatibility. Hence, this study aimed to improve polysulfone (PSf ) membrane surface properties by the addition of iron oxide nanoparticles (IONPs ). The membrane surface properties and separation performance of neat PSf membrane and membrane filled with IONPs at a loading of 0.2 wt% were investigated and compared. The membranes were characterized in terms of morphology, pure water permeability (PWP ) and protein rejection using bovine serum albumin (BSA ). A decrease in contact angle value from 66.62° to 46.23° for the PSf /IONPs membrane indicated an increase in surface hydrophilicity that caused positive effects on the PWP and BSA rejection of the membrane. The PWP increased by 40.74% to 57.04 L m^?2 h^?1 bar^?1 when IONPs were incorporated due to the improved interaction with water molecules. Furthermore, the PSf /IONPs membrane rejected 96.43% of BSA as compared to only 91.14% by the neat PSf membrane. Hence, the incorporation of IONPs enhanced the PSf hollow fiber membrane hydrophilicity and consequently improved the separation performance of the membrane for hemodialysis application. © 2017 Society of Chemical Industry     

Modelling touch-interaction time on smartphones

Accurate performance models are important for interaction technique, application, and hardware design. The limited screen size of mobile devices and use of touch interaction require unique considerations, especially when interacting with large amounts of information. This paper considers the performance impact of target visibility on mobile smartphone applications that provide on- and offscreen content with the commonly used direct-touch interactions and four cursor-based interaction methods for precise selection. Three existing and 12 novel performance models are experimentally validated. Fitts' Law, which was not designed for modelling selection of offscreen targets, did not predict interaction times for mobile interaction methods as accurately as is commonly observed with desktop interaction with onscreen targets. Target visibility was found to greatly impact interaction times (particularly for direct-touch interaction). The presented models that incorporate variables related to target visibility greatly improve predicted interaction times. The use and merits of the top models are discussed, emphasizing the importance and implications of accepted user-interface design guidelines.     

Reversible Switching of Battery Internal Resistance Using Iongate Separators

Battery separators are a critical component that greatly determine cell calendar life and safety. Generally, these separators are passive with no ability to reversibly change their properties in order to optimize battery performance. Here, an iongate separator is demonstrated, which allows ion transport while in the oxidized “on” state but limits ion transport when switched to the reduced “off” state. This is achieved by depositing a dense 300 nm thin film of polypyrrole:polydopamine (PPy:PDA) on a conventional polyolefin separator. By using this iongate separator as a third electrode, a rapid and reversible order of magnitude increase of iongate resistance is achievable. The iongate battery shows similar cycling performance to a normal battery while in the “on” state, but cycling can be reversibly shut-off when the iongate separator is reduced to the “off” state. During elevated temperature storage with the iongate separator in the “off” state, battery capacity loss is decreased by 37% and transition metal crossover is greatly suppressed when compared to a normal battery without the iongate. Additionally, rapid shut-off during discharge is demonstrated by directly shorting the iongate separator to the anode.     

Increasing adherence to mine plan through data integration and process change

This paper focuses on the development of a decision support element to control real-time adherence to mine plan within a control room environment. This system, known as a mine planning screen (MPL), integrates mine planning and production processes. The key inputs are production data tracked by the fleet management system and mine plans entered by mine planners into spreadsheets. The data are integrated with the use of database query languages and MPL charts are displayed in a web environment. The MPL screen displays two types of information: real-time adherence to plan by pit and historical adherence by crews. The objective of the screen is to increase adherence to the overall plan, a key part of a larger real-time blending initiative. This research discusses the technical development of the new tool, its deployment and peer pressure technique for user motivation.     

A comparison of economy and sagittal plane trunk movements among back-, back/front- and head-loading

It has been suggested that freedom of movement in the trunk could influence load carriage economy. This study aimed to compare the economy and sagittal plane trunk movements associated with three load carriage methods that constrain posture differently. Eighteen females walked at 3?km^.h^?1 with loads of 0, 3, 6, 9, 12, 15 and 20?kg carried on the back, back/front and head. Load carriage economy was assessed using the Extra Load Index (ELI). Change in sagittal plane trunk forward lean and trunk angle excursion from unloaded to loaded walking were assessed. Results show no difference in economy between methods (p?=?.483), despite differences in the change in trunk forward lean (p?=?.001) and trunk angle excursion (p?=?.021) from unloaded to loaded walking. We conclude that economy is not different among the three methods of load carriage, despite significant differences in sagittal plane trunk movements.

Practitioner summary: This article shows, based on mean data, that there is no difference in economy among back, back/front and head-loading, despite differences in trunk movement. It is possible a combination of factors align to influence individual economy, rather than a single set of factors, applicable to all individuals for each method.