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Flow Line Reducing Tetrahedral Metal Effect Pigments for Injection Molding A Yield Rate Improved Particle Manufacturing Method Based on Soft UVImprint Lithography
Full text linkThis publication presents an improved manufacturing method for tetrahedral metal effect pigment particles that demonstrates reduced flowlines in injection molded polymer components compared with conventional platelet shaped pigment particles. The previously published cold forming process for tetrahedral particles, made entirely from aluminum, faced manufacturing challenges, resulting in a high reject rate due to particle adhesion to the micro structured mold roller. In contrast, this study introduces a new manufacturing method for tetrahedral particles, now consisting of metallized UV cured thermoset polymer. These particles, dispersed in amorphous matrix thermoplastics, have shown to maintain their shape during the injection molding process. The manufacturing technique for these novel particles is based on UV imprint lithography, omitting the reject rates compared with the previously presented cold rolling process of tetrahedral full aluminum particles. Thus, the novel manufacturing technique for tetrahedral pigment particles shows increased potential for automation through roll to roll manufacturing in the futur
X ray tomography analysis of intermetallics and voids in 6XXX alloys
Full text linkSustainable aluminum production for the automotive industry with a high content of recycled material offers considerable potential for CO2 footprint reduction and cost savings. A three dimensional characterization of cast AA6016 alloys with lt;50 wt and gt;75 wt of recycled aluminum was carried out to assess the volume fraction, total number and surface area of intermetallics and casting voids using high resolution synchrotron X ray tomography. A new data analysis method is presented to describe morphology of intermetallics based on a surface area volume by volume plot, which allows for better classification of their different geometry clusters even for small modifications of Fe and Mn in the cast allo
Direct X Ray imaging for the new pinhole diagnostics at BESSY II
Full text linkIn order to improve our transverse diagnostic tools, two new pinhole beamlines will be designed. The pinhole arrays will be in air for easier maintenance this will result in a significant loss of X Ray photons when passing through the vacuum window. To overcome this issue, the option to directly illuminate a CCD CMOS camera with X Ray radiation without prior conversion into visible light is under study. Tests in the existing beamline both with a conventional CMOS camera and with a dedicated X Ray camera are foreseen. This report describes our findings regarding the current status regarding the use of X Ray cameras as a high flux diagnostic tool, as well as our preliminary experimental result
Direct diode detection tune measurement in the BESSY II booster
Full text linkThe Direct Diode Detection 3D method for transverse tune measurement, which was developed at CERN, has been implemented in numerous hadron machines and has recently been tested in electron machines. This method can provide orders of magnitude greater sensitivity to betatron oscillations than conventional beam position measurement approaches, which is particularly useful in fast ramping synchrotrons such as the Booster of the BESSY II light source. Typical systems used for tune measurement in an electron storage ring, which rely on the beam being in a relatively steady state, are not well suited for fast ramping machines; in order to measure the tune throughout the full acceleration ramp using conventional beam position approaches in the BESSY II Booster, it is necessary to use large external excitation which disturbs injection into the storage ring. Here we describe tune measurement in the BESSY II Booster using diode detectors, which allows for tune measurements during the full acceleration ramp with little to no external excitation and therefore no disturbance to user operatio
Exploratory tests for the design of a Python accelerator middle layer
Full text linkSeveral laboratories and facilities recently started joined efforts towards the realization of a python accelerator middle layer pyAML for control, tuning and optimization. This software is intended as a successor to matlab middle layer MML , inheriting its features but also expanding to new ones e.g., nonlinear optics and machine learning tools . Presently, several codes are available that provide some of the desired features. These codes have been adapted and tested at several of the participating laboratories to give input to the design of the pyAML. The most relevant features and results have been analyzed and are presented here together with the implications for the pyAML desig
Investigation of detector backlighting and other effects in neutron darkfield images
No full textNeutron imaging can provide unique contrast mechanisms. In order to yield reliable and reproducible attenuation coefficients for quantification, one needs to fully understand and characterize the experimental setup. One effect that has been largely overlooked in scintillator camera based neutron imaging systems, is the backlight scattering or back illumination in the detection system itself, which can significantly affect the quantification of attenuation coefficients and can lead to severe errors and image artifacts. Herein, the backlighting effects are investigated by varying the illuminated detector area and the magnitude of the attenuation. The attenuation coefficient of multiple metal plates was determined by polychromatic neutrons at the CONRAD V7 instrument. We found that the strength of the back illumination effect strongly depends on the sample absorption. While it is relatively moderate a few percent for weak absorbing samples, it can be severe when the sample is a strong absorber or when it is comparable thic
Direct Determination of a Giant Zero Field Splitting of 5422 cm 1 in a Triplet Organobismuthinidene by Infrared Electron Paramagnetic Resonance
No full textStable monocoordinated organobismuthinidenes were only recently isolated and analyzed toward their chemical and electronic structure. Quantum chemical calculations on tBu MSFluind Bi I 2 predicted an unusual electronic structure dominated by a triplet ground state and a spectacular zero field splitting ZFS gt; 4500 cm 1. However, experimental evidence for these predictions remained elusive due to limitations in the available magnetic characterization techniques. Herein, we determine an axial ZFS of D 5422 cm 1 for 2, by direct detection of triplet electron paramagnetic resonance using magneto optical infrared spectroscopy. To date, this represents the largest ZFS experimentally measure
Electrostatic and Electronic Effects on Doped Nickel Oxide Nanofilms for Water Oxidation
No full textAn ideal water splitting electrocatalyst is inexpensive, abundant, highly active, stable, selective, and durable. The anodic oxygen evolution reaction OER is the main bottleneck for H2 production with a complex and not fully resolved mechanism, slow kinetics, and high overpotential. Nickel oxide based catalysts NiOx are highly active and cheaper than precious metal catalysts. However, rigorous catalyst tests and DFT calculations are still needed to rationally optimize NiOx catalysts. In this work, we combine plasma enhanced atomic layer deposition PE ALD and density functional theory DFT to address the role of dopants in promoting NiOx OER activity. Ultrathin films of NiOx doped with Zn2 , Al3 , and Sn4 presented improved intrinsic activity, stability, and durability for the OER. The results show a low to high catalytic performance of ZnNiOx lt; NiOx lt; AlNiOx lt; SnNiOx, which we attribute to an increase in the concentration of valence band VB holes combined with conduction band CB electron conductivity, characterized by electrochemical impedance spectroscopy EIS . The influence of doping on the electronic structure and catalytic activity was investigated using advanced characterization techniques and density functional theory DFT calculations PEB0 pob TZVP . DFT complements the experimental results, showing that the dopant charge states and orbital hybridization enhance the OER by improving the charge carrier concentration and mobility, thus allowing optimal binding energies and charge dynamics and delocalization. Our findings demonstrate the potential of PE ALD doped nanofilms NiOx and DFT to rationally design and develop catalysts for sustainable energy application
Substrate preference, RNA binding and active site versatility of Stenotrophomonas maltophilia nuclease SmNuc1, explained by a structural study
No full textNucleases of the S1 P1 family have important applications in biotechnology and molecular biology. We have performed structural analyses of SmNuc1 nuclease from Stenotrophomonas maltophilia, including RNA cleavage product binding and mutagenesis in a newly discovered flexible Arg74 motif, involved in substrate binding and product release and likely contributing to the high catalytic rate. The Arg74Gln mutation shifts substrate preference towards RNA. Purine nucleotide binding differs compared to pyrimidines, confirming the plasticity of the active site. The enzyme product interactions indicate a gradual, stepwise product release. The activity of SmNuc1 towards c di GMP in crystal resulted in a distinguished complex with the emerging product 5 amp; 8242; GMP. This enzyme from an opportunistic pathogen relies on specific architecture enabling high performance under broad conditions, attractive for biotechnologie