This article analyzes temperature fields and their variations in fused filament fabrication (FFF) from the filament entering the hot-end to the printed parts, aiming at a deeper understanding of the thermal process of this additive manufacturing technology. A standard E3D print head assembly was mounted on a robot arm for printing. A stable filament feeding region was determined with an upper limit in the volume flow rate at different nozzle temperatures.
View Article and Find Full Text PDFPhotodetachment photoelectron spectroscopy (PD-PES) on molecular radical anions provides electron affinities and direct spectroscopic access to the lowest triplet states T(1) and T(2) of the corresponding neutral molecules. Herein, we apply this method to investigate trans-stilbene (SB), all-trans-1,4-diphenyl-1,3-butadiene (DPB), and all-trans-1,6-diphenyl-1,3,5-hexatriene (DPH). Our gas-phase T(1) energies agree with previous measurements on condensed crystals.
View Article and Find Full Text PDFIn this work, we apply photodetachment photoelectron spectroscopy (PD-PES) on radical anions to access the lowest excited electronic states of neutral α-oligothiophenes nT (n = 2-6, where n denotes the number of thiophene rings) in the gas phase. Besides electron affinities, the spectra provide the energies of the T(1) and T(2) states which are otherwise difficult to investigate in neutral molecules due to spin selection rules. The assignment of the spectra is assisted by quantum chemical calculations using a combined density functional theory and multi-reference configuration interaction approach.
View Article and Find Full Text PDFThis paper demonstrates that photodetachment photoelectron spectroscopy (PD-PES) of non-covalently bound heteromolecular anion clusters allows direct access to neutral contact charge transfer (CCT) states. The 2,2'-bithiophene.indole cluster is investigated as a model system in such a way that both chromophores have similar optical excitation cross-sections and hence the PD-PES shows the signature of both molecules.
View Article and Find Full Text PDFTissue expansion is a widespread and accepted concept in reconstructive surgery, but is also afflicted with a variety of complications. In burn patients, this technique allows large areas of burn scar to be replaced by tissue of similar texture and colour to the defect. We retrospectively reviewed our results with tissue expanders in 57 burn patients over a period of 8 years including 102 expanders.
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