Morphological and magnetic response of copper-substituted nickel ferrite nanoparticles

Ferrite nanoparticles are interesting materials owing to their unique physical and chemical properties. The metal-doped ferrites have well-defined structures and magnetic response, such as high permeability for a specific frequency range. In this study, copper-substituted nickel ferrite (Ni_1?xCu_xFe₂O₄) nanoparticles with a compositional range of 0?≤?x?≤?0.3 were synthesised through a co-precipitation technique. Metal chlorides were used as precursors and NaOH as a precipitating agent for the growth of ferrite nanoparticles. To minimise the internal stresses and maximise the magnetic response, ferrite nanoparticles were annealed in a furnace at 700°C for 6 h. The structural and magnetic response of Ni_1?xCu_xFe₂O₄ ferrite with different values of x were investigated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FT-IR), Vibrating Sample Magnetometer (VSM) and X-ray Diffraction (XRD) techniques. XRD analysis confirmed the formation of cubic spinel structure of single phase for all the compositions. The lattice constant decreased with increase in the value of x. FT-IR study showed two main metal oxygen bonds in the range 500–700 cm^?1 confirming the formation of a single-phase cubic inverse structure of Cu-substituted Ni ferrite. VSM results revealed the formation of ferrimagnetic nanoparticles. The optical and magnetic response of the ferrite nanoparticles changed with Cu content.     

Timing strategies used in defensive blinking to optical collisions in 5- to 7-month-old infants

When objects approach on a collision course, young babies will blink to protect their eyes. The timing of the blink is crucial, since it serves to protect the eyes from being injured. The image of a looming virtual object approached infants under different constant velocities and constant accelerations. The youngest infants (5–6 months) blinked when the image of the virtual object reached a threshold visual angle, while older infants (6–7 months) geared their blinks to the image’s time-to-collision. Infants using a strategy based on time coped successfully with all approach conditions, while infants using a strategy based on visual angle had difficulty with the fastest accelerative approach condition. The findings indicate that infants around 6 months of age shift to a more sophisticated strategy based on time, allowing them to deal with more demanding perceptual tasks.     

Infants' timing strategies to optical collisions: a longitudinal study

Blinking is a good indication of awareness to optical collisions in early infancy. In the current longitudinal study, infants were presented with the image of a looming virtual object approaching on a collision course under different constant velocities and constant accelerations. The aim was to investigate which timing strategies the infants used to determine when to make the defensive blink. Blinking when the virtual object reaches a threshold visual angle (angle-strategy) or angular velocity would result in difficulties with accelerating approaches, while blinking when the object is a certain time away (time-strategy) would enable successful responses to all approaches. Eleven infants were tested longitudinally at 22, 26, and 30 weeks. Five infants switched from an angle- to a time-strategy, while one infant switched from using angular velocity to a time-strategy. Five infants used a time-strategy already at 22 weeks. These findings show that with age there is an attunement in the perceptual systems of infants which makes them switch to better specifying variables, enabling them to successfully time their defensive blinking to impending optical collisions.     

Goals as identities: Boosting perceptions of healthy-eater identity for easier goal pursuit

People who think of their personal goals as identities are more likely to engage in goal-consistent behavior. However, no research has explored whether learning to frame goals as identities can be an effective strategy for pursuing goals in daily life. Across a series of studies, we assessed how incorporating a goal as part of one’s identity impacts goal-consistent choices. In a pilot study, we established a positive correlational relationship between natural goal identification and goal-consistent decision-making. Individuals with stronger healthy-eater identities made healthier food choices in a behavioral choice task. In Studies 1 and 2, we employed longitudinal interventions to teach people to frame their healthy eating goals as identities. We found that people who learned to frame their goals as identities made healthier choices, felt their goals were easier to pursue, reported greater success at managing goals, and made food choices that they both perceived to be healthier and that were rated as healthier by independent evaluators. Across studies, our findings suggest that thinking of goals as identities makes it easier to engage in goal-consistent choices.

     

Poor peer work does not boost student confidence

Students' low confidence, particularly in numerical topics, is thought to be a barrier to keeping them engaged with education. We studied the effects on confidence of exposure to a peer's work of varying quality (very good or bad) and neatness (messy or neat). Previous research underpinned our hypothesis that a peer's bad-quality work—which students rarely see—might boost student confidence more than very good work. We also predicted that a peer's very good work—which students are often shown—might be less discouraging if it were messy, suggesting it required effort and struggle. However, in experiments with university students and low-educated adults, these hypotheses were not supported, and all participants decreased in confidence after seeing any peer work. The failure to find support for these hypotheses can inform future research into social comparison effects on self-confidence in numerical topics. These results also have practical implications for teachers and managers who are expected to provide examples of peer work.     

Temporal order relations in language comprehension

The role of temporal orientation (chronological or reverse) and chronological distance (close, intermediate, or distant) in general event knowledge on language comprehension was examined. Experiment 1 used a relation-recognition paradigm in which the comprehension of a target event could be facilitated or disrupted by the temporal orientation implied by the prior information. Experiments 2 and 3 used a sentence-probe-recognition paradigm in which the temporal orientation, the stimulus onset asynchrony, and the chronological distance between the sentence event and the probe event were manipulated. The results demonstrated that readers used temporal information conveyed by their knowledge to construct situation models while comprehending sentences. The internal temporal dimension appeared to be directional and reflected the chronological distance between everyday events.     

From religious association to ethnic community: a research project on identity formation among the Syrian orthodox under muslim rule

At the Universityof Leiden, a research group is investigating the formation of a communal identity among West Syrian (or Syrian Orthodox) Christians after the Council of Chalcedon in 451 CE. Of the anti-Chalcedonians, the Syrian Orthodox were probably least likely to form a national or ethnic community. Yet a group emerged with its own distinctive literature and art, its own network and historical consciousness. In a process of adoption and rejection, the West Syrians selected elements from the cultures to which they were heirs and from those with which they came into contact, thus defining a position of their own. In order to study this phenomenon, scholars from various disciplines and affiliated to two different faculties are working together. This paper discusses their research programme and its basic hypothesis.