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Aufsatz
Promoting abnormal grain growth in Fe-based shape memory alloys through compositional adjustments
(2019-05-28)
Iron-based shape memory alloys are promising candidates for large-scale structural applications due to their cost efficiency and the possibility of using conventional processing routes from the steel industry. However, recently developed alloy systems like Fe–Mn–Al–Ni suffer from low recoverability if the grains do not completely cover the sample cross-section. To overcome this issue, here we show that small amounts of titanium added to Fe–Mn–Al–Ni significantly enhance abnormal grain growth due to a considerable ...
Aufsatz
Wünschenswerte Erschwernisse beim Lernen
(2015)
Der Beitrag beleuchtet didaktische Maßnahmen, die unter dem Begriff „Wünschenswerte Erschwernisse“ zusammengefasst werden. Diese Maßnahmen erschweren zwar kurzfristig das Lernen, langfristig aber fördern sie das Behalten und den Transfer des Gelernten. Vier dieser wünschenswerten Erschwernisse sind empirisch besonders gut belegt: 1) Das verteilte Lernen, 2) das verschachtelte Lernen, 3) der Testungseffekt und 4) der Generierungseffekt. Zu jeder dieser wünschenswerten Erschwernisse werden aktuelle Forschungsergebnisse ...
Aufsatz
Girls in detail, boys in shape: Gender differences when drawing cubes in depth
(2013)
The current study tested gender differences in the developmental transition from drawing cubes in two‐ versus three dimensions (3D), and investigated the underlying spatial abilities. Six‐ to nine‐year‐old children (N = 97) drew two occluding model cubes and solved several other spatial tasks. Girls more often unfolded the various sides of the cubes into a layout, also called diagrammatic cube drawing (object design detail). In girls, the best predictor for drawing the cubes was Mental Rotation Test (MRT) accuracy. ...
Aufsatz
Shape But Not Color Facilitates Two-Year-Olds’ Search Performance in a Spatial Rotation Task
(2018)
Children younger than 3 years of age often fail to track hidden objects that are rotated together with identical hiding containers, which might be due to relatively complex paradigms. We examined whether 2-year-olds (N = 28) are already able to track spatial rotations (i.e., by 90° and 180°) if the task is facilitated by increasing the visual discriminability of the hiding containers by means of different shapes and different colors. Children performed above chance level in all conditions except for the condition in ...
Aufsatz
Let’s twist again! Embodiment effects in spatial judgments on human figures rotated along a vertical axis
(2017)
We investigated whether individuals used mental rotation and embodiment for arm laterality judgments of human figures that were stepwise rotated from back view to front view along a vertical axis. In Experiment 1, figures’ heads were always shown in profile, while only the bodies were rotated. Judgments were faster and more correct when figures were presented in back view compared to front view, but the relation between reaction times (RTs) and rotation angles was not strictly linear. In addition, judgments on figures ...
Aufsatz
Access to the learning material enhances learning by means of generating questions: Comparing open- and closed-book conditions
(2020)
Generating questions referring to the learning material is a powerful learning strategy. The present study investigated potential mechanisms behind this effect. Students (N=231) read a text and then generated questions referring to the text in three conditions: (1) open-book (i.e., text accessible), (2) closed-book (i.e., text inaccessible), and (3) cued closed-book (i.e., text inaccessible but keywords provided). After one week, students’ knowledge gain was larger in the open-book and cued closed-book conditions ...
Aufsatz
Occurrence, distribution and alternative hosts of Wheat streak mosaic virus infecting ginger in Kaduna State, Nigeria
(2020-06-29)
A field survey was conducted during the 2018 rainy season (June – October) in three major ginger producing Local Government Areas (LGAs) of Kaduna State, Nigeria to determine the occurrence and spread of wheat streak mosaic virus (WSMV) infecting ginger. Symptomatic and asymptomatic ginger leaf samples (n=180) and weed samples (n=45) were collected from the surveyed fields and indexed against WSMV using Double Antibody Sandwich Enzyme-linked Immunosorbent Assay (DAS-ELISA). The results obtained showed that WSMV ...
Aufsatz
Verbal facilitation effects instead of verbal overshadowing in face memory of 4- to 6-year olds
(2015)
Research on eye witness memory in older children and adults revealed that verbally describing unfamiliar faces impairs later recognition of these faces, known as the “verbal overshadowing effect”. The aim of this study was to investigate whether a verbal overshadowing effect occurs in 4- to 6-year olds, too, and whether visualization (i.e., drawing the seen face) might elicit a visual overshadowing effect. Instead of a verbal overshadowing effect, a verbal facilitation effect was revealed with verbal intelligence ...
Aufsatz
Typology of smallholder’s pig production systems in South Kivu, Democratic Republic of Congo: Challenges and opportunities
(2020-06-30)
Pig farming plays an important role in farmers’ livelihoods in many tropical countries. It contributes to food security of the poorest as well as the development of rural economy through multiplier effects. In the South Kivu province, pig farms are almost exclusively owned by smallholders. A few studies have attempted to describe thoroughly pig farming systems in this province. This study was undertaken to characterise pig production systems, in order to better understand their current situation, namely constraints ...
Aufsatz
On the structural integrity of Fe-36Ni Invar alloy processed by selective laser melting
(2020)
Specimens made from pre-alloyed Invar (Fe-36Ni) powder were fabricated by selective laser melting and stress-relief heat treated afterwards. A relative density of the fabricated parts of 99.6 % was determined by computed tomography. The microstructure and mechanical behavior under monotonic and particularly cyclic loading at ambient temperature were investigated. Results reveal a bimodal microstructure containing columnar and equiaxed grains with an average grain size of 75 μm and pronounced texture 〈001〉 || BD. The ...