II3V2 (II: Zn,Cd; V: P,As) Semiconductors: From Bulk Solids to Colloidal Nanocrystals

II₃V₂ semiconductors have become increasingly popular for a variety of applications including solar light harvesting, near‐IR imaging, and low energy light detection. The bulk physical and electronic structure of these materials is highlighted, followed by an in‐depth survey on progress in synthesizing these semiconductors as colloidal nanocrystals. Interestingly, no universal synthetic approach has yet been developed to access all compounds within this family. A discussion on how the complex crystal structure of these materials translates to small domain sizes will highlight current challenges in the characterization of II₃V₂ nanocrystals. Finally, potential avenues for further research will be proposed as a way to advance this field towards greater utilization in light harvesting applications.     

Compliant activity rather than difficulty accelerates thought probe responsiveness and inhibits deliberate mind wandering

ABSTRACT

Mind wandering is a commonly intruding cognitive state that leads to diminished performance and increased error risk during a primary task. A controversy over whether easier or more difficult tasks increase mind wandering has led to mind wandering being proposed as two different states: deliberate and spontaneous. We hypothesise that forced engagement via persistent compliant activity may both increase responsiveness and inhibit non-instrumental activities including deliberate mind wandering. Twenty-eight healthy adults interacted with 2 pairs of stimuli, each pair having one low-interactivity version and a high-interactivity version requiring compliant activity. Mind wandering was assessed by thought probes, and subjective responses were rated using visual analogue scales. Reaction times were measured using Superlab. Compliant activity decreased the prevalence of deliberate mind wandering episodes but not of overall mind wandering. Thought probe durations were accelerated significantly by compliant activity, near-significantly by thinking on-task thoughts, and additively by the combination of both. Deliberate and spontaneous mind wandering elicited equivalent thought probe durations. We conclude that compliant activity works synergistically with lack of mind wandering to accelerate the difficult task of thought probe response but not simple reaction times. These results fit with an arousal model but not the attentional resources model.     

Impact of spinel forming systems (Fe-/Mg-/Mn-Al-O) as functional coating materials for carbon-bonded alumina filters on steel melt filtration

Since solid, non-metallic inclusions influence considerably the quality of casted steel products, carbon-bonded alumina foam filters are used in secondary metallurgical treatments to remove these particles from steel melts. In order to attain a significant improvement of the filtration process, five different carbonaceous spinel compounds from the Fe-/Mg-/Mn-Al-O systems are applied on carbon-bonded alumina filters in this study and investigated with regard of their filtration efficiency. However, these spinel compounds decompose partially during sintering at 1400?°C under reducing atmosphere, wherefore the resulting coatings contain not only spinel compounds, but also oxidic and metallic components. The subsequent interaction with molten steel leads to the development of multicrystal structures on the filter surface, which stem from interfacial reactions between coating materials, molten steel, and inclusions. As a result of this procedure, a reduction of almost 60% alumina inclusions is measured with the aid of an automatic SEM, whereby spinel compounds from the Fe-Mn-Al-O system achieve highest filtration efficiencies.     

Purification of Nickel Sulfate by Batch Cooling Crystallization

Cooling crystallization was successfully carried out in a batch cooling crystallizer from impure acidic solutions to recover nickel as nickel sulfate salt with three different cooling rates. The compositions of the solutions included impurities of sodium, magnesium, chloride, and sulfuric acid to mimic industrial nickel electrowinning process solutions. The results show that NiSO₄·6H₂O mainly crystallized, and its solubility and purity decreased with the increase in the mass ratio of chloride to sulfate. Cooling rates did not have a significant influence on crystal purity; however, it did affect the filter cake moisture; lower moisture can be obtained with a lower cooling rate. The sequence of impurity removal efficiency from high to low was Cl > Na > Mg.     

LSALSA: accelerated source separation via learned sparse coding

Machine Learning - We propose an efficient algorithm for the generalized sparse coding (SC) inference problem. The proposed framework applies to both the single dictionary setting, where each data...     

On the emergence of intelligent global behaviours from simple local actions

Artificial intelligence focuses on the question of how to design systems to exhibit intelligent behaviour in complex environments. Complex global behaviours can emerge from simple systems acting in a complex environment; however, this emergence requires that the systems' internal structure reflects essential structures in the environment This paper examines the algebraic structure of a system's actions. We find that these actions often possess a self-similar local neighbourhood structure that permits analysis and synthesis to be performed locally and yet produces global intelligent behaviours. A procedure for finding this local structure is presented and illustrated with examples.     

Plowing with precedence: A variant of the windy postman problem

In winter, a common problem is to determine the route that a snowplow should take in order to minimize the distance traveled. We propose a variant of this arc routing problem that is motivated by the fact that deadhead travel over streets that have already been plowed is significantly faster than the time it takes to plow the street. This problem differs from most arc routing problems because the cost of traversing a street changes depending on the order of the streets on a route. We develop a method that generates near-optimal solutions to instances as large as 200 nodes.