Effect of scan strategies and use of support structures on surface quality and hardness of L-PBF AlSi10Mg parts

Additive manufacturing allows for a great degree of design freedom and is rapidly becoming a mainstream manufacturing process. However, as in all manufacturing processes, it has its limitations and specificities. Equipping engineers with this knowledge allows for a higher degree of optimization, extracting the most out of this technology. Therefore, a specific part design was devised and created via L-PBF (Laser Powder Bed Fusion) using AlSi10Mg powder. Certain parameters were varied to identify the influence on material density, hardness, roughness, residual stress and microstructures. It was found that on heat treated parts laser pattern strategy is one of the most influential aspects, showing that chessboard and stripes 67° improved outcome; average Ra roughness varied between 8-12 μm, residual stress was higher on vertical surfaces than horizontal surfaces, with the combination of support structures and stripes 67° strategies generating the lowest residual stress (205 MPa on a lateral/vertical face), hardness was non-orientation dependent and larger on samples with chessboard fabrication strategies, while microstructures were composed of α-Al dendrites surrounded by Si particles. The distribution and grain size of the microstructure is dependent on location regarding melt pool and HAZ area. Furthermore, Al-Mg oxides were encountered on the surface, along with pores generating from lack of fusion

Correction for Sormaz et al., Default mode network can support the level of detail in experience during active task states

PSYCHOLOGICAL AND COGNITIVE SCIENCES Correction for “Default mode network can support the level of detail in experience during active task states,” by Mladen Sormaz, Charlotte Murphy, Hao-ting Wang, Mark Hymers, Theodoros Karapanagiotidis, Giulia Poerio, Daniel S. Margulies, Elizabeth Jefferies, and Jonathan Smallwood, which was first published August 27, 2018; 10.1073/pnas.1721259115 (Proc Natl Acad Sci USA 115:9318–9323)

“Mind the Trap”: Mindfulness Practice Reduces Cognitive Rigidity

Two experiments examined the relation between mindfulness practice and cognitive rigidity by using a variation of the Einstellung water jar task. Participants were required to use three hypothetical jars to obtain a specific amount of water. Initial problems were solvable by the same complex formula, but in later problems (“critical” or “trap” problems) solving was possible by an additional much simpler formula. A rigidity score was compiled through perseverance of the complex formula. In Experiment 1, experienced mindfulness meditators received significantly lower rigidity scores than non-meditators who had registered for their first meditation retreat. Similar results were obtained in randomized controlled Experiment 2 comparing non-meditators who underwent an eight meeting mindfulness program with a waiting list group. The authors conclude that mindfulness meditation reduces cognitive rigidity via the tendency to be “blinded” by experience. Results are discussed in light of the benefits of mindfulness practice regarding a reduced tendency to overlook novel and adaptive ways of responding due to past experience, both in and out of the clinical setting

Investigating the impact of mindfulness meditation training on working memory: A mathematical modeling approach

We investigated whether mindfulness training (MT) influences information processing in a working memory task with complex visual stimuli. Participants were tested before (T1) and after (T2) participation in an intensive one-month MT retreat, and their performance was compared with that of an age- and education-matched control group. Accuracy did not differ across groups at either time point. Response times were faster and significantly less variable in the MT versus the control group at T2. Since these results could be due to changes in mnemonic processes, speed–accuracy trade-off, or nondecisional factors (e.g., motor execution), we used a mathematical modeling approach to disentangle these factors. The EZ-diffusion model (Wagenmakers, van der Maas, & Grasman, Psychonomic Bulletin & Review 14:(1), 3–22, 2007) suggested that MT leads to improved information quality and reduced response conservativeness, with no changes in nondecisional factors. The noisy exemplar model further suggested that the increase in information quality reflected a decrease in encoding noise and not an increase in forgetting. Thus, mathematical modeling may help clarify the mechanisms by which MT produces salutary effects on performance

Mindful Parenting in Mental Health Care

Mindfulness is a form of meditation based on the Buddhist tradition, which has been used over the last two decades to successfully treat a multitude of mental health problems. Bringing mindfulness into parenting (“mindful parenting”) is one of the applications of mindfulness. Mindful parenting interventions are increasingly being used to help prevent and treat mental disorders in children, parenting problems, and prevent intergenerational transmission of mental disorders from parents to children. However, to date, few studies have examined the hypothesized mechanisms of change brought about by mindful parenting. We discuss six possible mechanisms through which mindful parenting may bring about change in parent–child interactions in the context of child and parent mental health problems. These mechanisms are hypothesized to be mediated by the effects of mindfulness on parental attention by: (1) reducing parental stress and resulting parental reactivity; (2) reducing parental preoccupation resulting from parental and/or child psychopathology; (3) improving parental executive functioning in impulsive parents; (4) breaking the cycle of intergenerational transmission of dysfunctional parenting schemas and habits; (5) increasing self-nourishing attention; and (6) improving marital functioning and co-parenting. We review research that has applied mindful parenting in mental health settings, with a focus on evidence for these six mechanisms. Finally, we discuss directions for future research into mindful parenting and the crucial questions that this research should strive to answer

The influence of a short-term mindfulness meditation intervention on emotion and visual attention

It has been suggested that mindfulness meditation (MM) improves psychological wellbeing via the focusing and broadening of attention. Whilst studies show that short term MM interventions can improve focused attention there is little evidence to support the broadening of attention. The current study investigated the influence of a short-term MM intervention on emotion and the scope of visual attention. Seventy participants completed a global-local processing task separated into three blocks of trials, with a ten minute break between each one. During the breaks a MM group engaged in a breath counting task and a control group engaged in a task of their choosing. Response times to global and local targets and a measure of self-reported emotional affect were recorded for each block. Mindfulness had no impact on attention however both positive and negative affect decreased for the MM group across the course of the experiment. The results suggest that MM can reduce the focus on negative (and positive) thoughts, indicating possible changes to focused attention, yet a short-term intervention is not sufficient to broaden attentio

Plant economies and village life in Neolithic lake dwellings at the time of the Alpine Iceman

This paper gives an overview of domesticated and wild plants used during the 2nd half of the 4th millennium B.C. (cal.) in a region within a semicircle of ca. 100 km radius around the find spot of the Iceman. The landscape considered lies north of the main alpine chain and includes Central to Eastern Switzerland and SW-Germany (mainly sites at the lakes Zug, Zürich, Constance, Upper Swabia (the Federsee region) and western Bavaria). From this part of Central Europe the plant remains of many well preserved Lake dwelling sites were investigated during the last decades and much is known about the daily life in these villages. Probably contemporaneous with the Iceman’s lifetime is one of the best investigated settlements, Arbon Bleiche 3 at the southern shore of Lake Constance. A comparison of the Iceman´s artefacts and plant macro remains with the findings in the considered lake dwellings shows striking similarities, but also differences. Based on domestic plants found with the Iceman his southern provenience can be corroborated. He used domestic as well as wild plants, very similar as the contemporaries of the lakeside villages. The detailed knowledge of the manifold activities in the lakeshore village of Arbon Bleiche 3 allows us to show a rather realistic picture about the daily life circumstances at the time of the Iceman