The number of additive manufacturing methods and materials is growing rapidly, leaving gaps in the knowledge of specific material properties. A relatively recent addition is the metal-filled filament to be printed similarly to the fused filament fabrication (FFF) technology used for plastic materials, but with additional debinding and sintering steps. While tensile, bending, and shear properties of metals manufactured this way have been studied thoroughly, their fatigue properties remain unexplored. Thus, the paper aims to determine the tensile, fatigue, and impact strengths of Markforged 17-4 PH and BASF Ultrafuse 316L stainless steel to answer whether the metal FFF can be used for structural parts safely with the current state of technology. They are compared to two 316L variants manufactured via selective laser melting (SLM) and literature results. For extrusion-based additive manufacturing methods, a significant decrease in tensile and fatigue strength is observed compared to specimens manufactured via SLM. Defects created during the extrusion and by the pathing scheme, causing a rough surface and internal voids to act as local stress risers, handle the strength decrease. The findings cast doubt on whether the metal FFF technique can be safely used for structural components; therefore, further developments are needed to reduce internal material defects.

The current study evaluates a depression prevention program for adolescents led by psychologists vs. teachers in comparison to a control. The universal school-based prevention program has shown its efficacy in several studies when implemented by psychologists. The current study compares the effects of the program as implemented by teachers versus that implemented by psychologists under real-life conditions. A total of 646 vocational track 8th grade students from Germany participated either in a universal prevention program, led by teachers (n = 207) or psychologists (n = 213), or a teaching-as-usual control condition (n = 226). The design includes baseline, post-intervention, and follow-up (at 6 and 12 months post-intervention). The cognitive-behavioral program includes 10 sessions held in a regular school setting in same-gender groups and is based on the social information-processing model of social competence. Positive intervention effects were found on the change in girls’ depressive symptoms up to 12 months after program delivery when the program was implemented by psychologists. No such effects were found on boys or when program was delivered by teachers. The prevention program can successfully be implemented for girls by psychologists. Further research is needed for explanations of these effects.

Solidification and caking of bulk solids often occurs during storage or while being transported to the customer. To investigate the formation and growth of solid bridges between two discrete particles, the modification of the contact region between these two particles stored in a climatic chamber is examined. The effect of load, temperature, relative humidity, and storage time on the formation of a bridge is analyzed. The objective is to describe the behavior of crystalline or salt-like granules under real storage conditions.

To investigate the formation and growth of solid bridges between urea particles, the changes in the contact region between two discrete particles are measured. The work is carried out using a Double-Particle-System (DPS). The DPS was stored in a climatic chamber. The effect of load, temperature, relative humidity, and storage time on the formation of a bridge between these particles was analyzed. The objective was to describe the geometrical changes in the contact region and to measure the strength of the resulting interparticle bridge.

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