Aachen Technology Overview of 3D Textile Materials and Recent Innovation and Applications

Applied Composite Materials - This paper provides an overview of the recent definition, technologies and current trends regarding 3D fabrics. In this paper a definition of 3D fabrics, including...     

In Vitro Fermentation Behavior of Isomalto/Malto‐Polysaccharides Using Human Fecal Inoculum Indicates Prebiotic Potential

1 Scope

This study characterize intestinal fermentation of isomalto/malto‐polysaccharides (IMMPs), by monitoring degradation of IMMPs, production of short chain fatty acids (SCFAs), lactic acid, and succinic acid as well as enzyme activity and microbiota composition.

2 Methods and results

IMMP‐94 (94% α‐(1→6) glycosidic linkages), IMMP‐96, IMMP‐27, and IMMP‐dig27 (IMMP‐27 after removal of digestible starch segments) are fermented batchwise in vitro using human fecal inoculum. Fermentation digesta samples are taken for analysis in time up till 48 h. The fermentation of α‐(1→6) glycosidic linkages in IMMP‐94, IMMP‐96, and IMMP‐dig27 starts after 12 h and finishes within 48 h. IMMP‐27 fermentation starts directly after inoculation utilizing α‐(1→4) linked glucosyl residues; however, the utilization of α‐(1→6) linked glucoses is delayed and start only after the depletion of α‐(1→4) linked glucose moieties. SCFAs are produced in high amounts with acetic acid and succinic acid being the major products next to propionic acid and butyric acid. The polysaccharide fraction is degraded into isomalto‐oligosaccharides (IMOs) mainly by extracellular enzymes. The smaller IMOs are further degraded by cell‐associated enzymes. Overall microbial diversity and the relative abundance of Bifidobacterium and Lactobacillus, significantly increase during the fermentation of IMMPs.

3 Conclusion

IMMP containing segments of α‐(1→6) linked glucose units are slowly fermentable fibers with prebiotic potential.     

(−)‐Sparteine‐Mediated Directed ortho‐Metalation of N‐Cumyl‐N‐ethylferrocenecarboxamide. Versatile Routes to Functionalized Planar Chiral Ferrocenecarboxamides,Amines, Esters and Phosphines

N‐Cumyl‐N‐ethylferrocenecarboxamide 5 provides planar chiral carboxamides 6 in high yield and % ee via (−)‐sparteine‐mediated directed ortho‐metalation. Mild decumylation affords secondary amides 7 , which serve as intermediates for a convenient and general route to the venerable Ugi planar chiral ferrocenylamines 13 and as versatile precursors for the preparation of novel chiral ferrocenes 15 and 20 . The chiral TMS‐ferrocenyl derivative 7c is used to prepare the enantiomeric (S)‐ 7f , circumventing the lack of availability of (+)‐sparteine.     

Recycling-Induced Copper Contamination of a 42CrMo4 Quench and Tempering Steel: Alterations in Transformation Behavior and Mechanical Properties

The transformation behavior and the mechanical properties of three laboratory produced steels are presented. To investigate the influence of copper contamination, the reference alloy 42CrMo4 is modified and alloyed with 0.5 and 1.0 wt% copper, respectively. The transformation behavior is investigated through dilatometry that yields continuous cooling transformation diagrams, while the mechanical properties are investigated by hardness measurements as well as Charpy-V-notch impact and tensile tests. Accompanying microstructure investigations by means of light optical, scanning electron, and transmissions electron microscopy and thermodynamic simulations (CALPHAD) are performed. It is demonstrated that copper contamination that will be unavoidable when increasing the overall steel recycling fraction may contain the potential for increasing the hardness as well the strength of standard high strength steels, although it is considered to be very detrimental during steel production. Together with reduced environmental footprints and production costs due to the utilization of lower grade scrap with more Cu-contamination, the development of alternative processing routes for Cu-contamination-tolerant high strength steels is pursued.