X-ray detectors are of pivotal importance for the scientific and technological progress in a wide range of medical,industrial,and scientific ***,we take advantage of the printability of perovskite-based semiconductors...
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X-ray detectors are of pivotal importance for the scientific and technological progress in a wide range of medical,industrial,and scientific ***,we take advantage of the printability of perovskite-based semiconductors and achieve a high X-ray sensitivity combined with the potential of an exceptional high spatial resolution by our origami-inspired folded perovskite X-ray *** high performance of our device is reached solely by the folded detector architecture and does not require any *** design and fabrication of a foldable perovskite sensor array is presented and the detector is characterized as a planar and as a folded *** to 50 kVp−150 kVp X-ray radiation,the planar detector reaches X-ray sensitivities of 25−35μC/(Gyaircm^(2)),whereas the folded detector achieves remarkably increased X-ray sensitivities of several hundredμC/(Gyaircm^(2))and a record value of 1409μC/(Gyaircm^(2))at 150 kVp without photoconductive ***,the potential of an exceptional high spatial resolution of the folded detector of more than 20 lp/mm under 150 kVp X-ray radiation is demonstrated.
Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high ***,their performance and sustainability are significantly hindered by...
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Rechargeable aqueous zinc-metal batteries (AZMBs) are promising candidates for large-scale energy storage systems due to their low cost and high ***,their performance and sustainability are significantly hindered by the sluggish desolvation kinetics at the electrode/electrolyte interface and the corresponding hydrogen evolution reaction where active water molecules tightly participate in the Zn(H2O)62+solvation ***,learnt from self-generated solid electrolyte interphase (SEI) in anodes,the dielectric but ion-conductive zinc niobate nanoparticles artificial layer is constructed on metallic Zn surface (ZNB@Zn),acting as a rapid desolvation *** zincophilic and dielectric-conductive properties of ZNB layer accelerate interfacial desolvation/diffusion and suppress surface corrosion or dendrite formation,achieving uniform Zn plating/stripping behavior,as confirmed by electronic/optical microscopies and interface spectroscopical measurements together with theoretical ***,the as-prepared ZNB@Zn electrode exhibits excellent cycling stability of over 2000 h and robust reversibility (99.54%) even under high current density and depth of discharge ***,the assembled ZNB@Zn-based full cell displays high capacity-retention rate of 80.21%after 3000 cycles at 5 A g-1and outstanding rate performance up to 10 A *** large-areal pouch cell is stabilized for hundreds of cycles,highlighting the bright prospects of the dielectric but ion-conductive layer in further application of AZMBs.
Melt emulsification is a well known process. Milk is thus homogenized for over 100 years. In the melt emulsification process, the future disperse phase is melted and dispersed into droplets, the size of which is contr...
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Melt emulsification is a well known process. Milk is thus homogenized for over 100 years. In the melt emulsification process, the future disperse phase is melted and dispersed into droplets, the size of which is controlled by an emulsification process. After emulsification, the droplets are cooled down and solid particles of spherical shape are formed. In order to realize melt emulsification processes, we developed the new SHM (Simultaneous Homogenizing and Mixing) nozzle, which enables us to mix separate phases directly into the droplet forming zone of homogenization nozzles. This molten milk fat globule can be homogenized at elevated fat content (up to 42 vol% instead of max. 17 vol%) and elevated temperatures (up to 150 ℃ instead of max. 70 ℃) without loosing product quality as for conventional homogenization processes. In addition, more than 80% of the energy costs can be saved and additional mixing units can be spared. This is realized by a controlled and quick dilution and cooling down of molten fat globules directly after their disruption in the nozzle itself. SHM-technology also allows for the dispersing of molten waxes. Instant cooling down after adjusting particle sizes also allows us to work without emulsifiers or other additives as absolutely required in conventional melt emulsification processes where molten droplets will coalesce upon their collisions in the homogenization nozzle. SHM-melt emulsification is thus an alternative to conventional milling processes, which are often limited by the stickiness of these products.
Most of the times pumps operate off best point *** are changes of operating conditions,modifications,pollution and wearout or *** consequences non-rotational symmetric flows,transient operational conditions,increased ...
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Most of the times pumps operate off best point *** are changes of operating conditions,modifications,pollution and wearout or *** consequences non-rotational symmetric flows,transient operational conditions,increased risk of cavitation,decrease of efficiency and unpredictable wearout can *** construction components of centrifugal pumps,in particular intake elbows,contribute to this *** elbows causes additional losses and secondary flows,hence non-rotational velocity distributions as intake profile to the centrifugal *** a result the impeller vanes experience permanent changes of the intake flow angle and with it transient flow conditions in the blade *** paper presents the first results of a project,experimentally and numerically investigating the consequences of non-rotational inflow to leading edge flow conditions of a centrifugal *** two pumpintake-elbow systems are compared,by only altering the intake elbow geometry:a common single bended 90°elbow and a numerically optimized elbow(improved regarding rotational symmetric inflow conditions and friction coefficient).The experiments are carried out,using time resolved stereoscopic PIV on a full acrylic pump with refractions index matched(RIM)working *** allows transient investigations of the flow field simultaneously for all blade leading *** CFD results are validated and used to further support the investigation *** comparing an analog pump system with ideal inflow conditions.
Abrasive wear mechanisms—including two-body and three-body abrasion—dominate the performance and lifespan of tribological systems in many engineering fields,even of those operating in lubricated *** steel(100Cr6)pin...
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Abrasive wear mechanisms—including two-body and three-body abrasion—dominate the performance and lifespan of tribological systems in many engineering fields,even of those operating in lubricated *** steel(100Cr6)pins and discs in a flat-on-flat contact were utilized in experiments together with 5 and 13 μm Al_(2)O_(3)-based slurries as interfacial media to shed light on the acting *** results indicate that a speed-induced hydrodynamic effect occurred and significantly altered the systems'frictional behavior in tests that were performed using the 5 μm *** experiments revealed that a speed-dependent hydrodynamic effect can lead to a 14% increase in film thickness and a decrease in friction of around 2/3,accompanied by a transition from two-body abrasion to three-body abrasion and a change in wear mechanism from microcutting and microploughing to fatigue ***,no correlation could be found between the total amount of wear and the operating state of the system during the experiment;however,the wear distribution over pin and disc was observed to change *** paper studies the influence of the hydrodynamic effect on the tribological mechanism of lubricated abrasive wear and also highlights the importance to not only consider a tribological systems'global amount of wear.
Tailoring a material's properties for low friction and little wear in a strategic fashion is a long-standing goal of materials *** deformation plays a major role when metals are employed in a sliding contact;therefore...
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Tailoring a material's properties for low friction and little wear in a strategic fashion is a long-standing goal of materials *** deformation plays a major role when metals are employed in a sliding contact;therefore,the effects of stacking fault energy and mode of dislocation glide need to be ***,we investigated how a decrease in the stacking fault energy affects friction,wear,and the ensuing sub-surface microstructure *** samples with increasing zinc concentrations of 5,15,and 36 wt%were tested in non-lubricated sphere-on-plate contacts with a reciprocating linear tribometer against Si3N4 *** the sliding distance from 0.5(single trace)to 5,000 reciprocating cycles covered different stages in the lifetime of a sliding *** the results among the three alloys revealed a profound effect of the zinc concentration on the tribological ***15 and CuZn36 showed similar friction and wear results,whereas CuZn5 had a roughly 60%higher friction coefficient(COF)than the other two ***15 and CuZn36 had a much smaller wear rate than *** dislocation motion in CuZn5 and CuZn15 allowed for dislocation self-organization into a horizontal line about 150 nm beneath the contact after a single trace of the *** feature was absent in CuZn36 where owing to planar dislocation slip band-like features under a 45°angle to the surface were *** results hold the promise to help guide the future development of alloys tailored for specific tribological applications.
Optical micro-resonators have broad *** are used,for example,to enhance light–matter interactions in optical sensors or as model systems for investigating fundamental physical mechanisms in cavity quantum *** two or ...
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Optical micro-resonators have broad *** are used,for example,to enhance light–matter interactions in optical sensors or as model systems for investigating fundamental physical mechanisms in cavity quantum *** two or more micro-cavities is particularly interesting as it enlarges the design freedom and the field of *** this context,achieving tunability of the coupling strength and hence the inter-cavity gap is of utmost importance for adjusting the properties of the coupled micro-resonator *** this paper,we report on a novel coupling approach that allows highly precise tuning of the coupling gap of polymeric micro-resonators that are fabricated side by side on a common *** structure goblet-shaped whispering-gallery-mode resonators on an elastic silicone-based polymer substrate by direct laser *** silicone substrate is mechanically stretched in order to exploit the lateral shrinkage to reduce the coupling *** a laser dye into the micro-resonators transforms the cavities into micro-lasers that can be pumped *** have investigated the lasing emission by micro-photoluminescence spectroscopy,focusing on the spatial localization of the *** results demonstrate the formation of photonic molecules consisting of two or even three resonators,for which the coupling strengths and hence the lasing performance can be precisely *** and tunability are key elements in future photonics,making our approach interesting for various photonic *** instance,as our coupling approach can also be extended to larger cavity arrays,it might serve as a platform for tunable coupled-resonator optical waveguide devices.
Recently a low cost cooking device for developing and emerging countries was developed at kit in cooperation with the company Bosch und Siemens Hausger^ite GmbH. After constructing an innovative basic design further d...
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Recently a low cost cooking device for developing and emerging countries was developed at kit in cooperation with the company Bosch und Siemens Hausger^ite GmbH. After constructing an innovative basic design further development was required. Numerical investigations were conducted in order to investigate the flow inside the combustion chamber of the stove under variation of different geometrical parameters. Beyond the performance improvement a further reason of the investigations was to rate the effects of manufacturing tolerance problems. In this paper the numerical investigation of a plant oil stove by means of RANS simulation will be presented. In or- der to reduce the computational costs different model reduction steps were necessary. The simulation results of the basic configuration compare very well with experimental measurements and problematic behaviors of the ac- tual stove design could be explained by the investigation.
In this study, the probabilistic, data driven nature of the generative adversarial neural networks (GANs)was utilized to conduct virtual spray simulations for conditions relevant to aero engine combustors. Themodel co...
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In this study, the probabilistic, data driven nature of the generative adversarial neural networks (GANs)was utilized to conduct virtual spray simulations for conditions relevant to aero engine combustors. Themodel consists of two sub-modules: (i) an autoencoder converting the variable length droplet trajectories intofixed length, lower dimensional representations and (ii) a Wasserstein GAN that learns to mimic the latentrepresentations of the evaporating droplets along their lifetime. The GAN module was also conditioned withthe injection location and the diameters of the droplets to increase the generalizability of the whole *** training data was provided from highly resolved 3D, transient Eulerian–Lagrangian, large eddy simulationsconducted with OpenFOAM. Neural network models were created and trained within the open source machinelearning framework of PyTorch. Predictive capabilities of the proposed method was discussed with respect tospray statistics and evaporation dynamics. Results show that conditioned GAN models offer a great potentialas low order model approximations with high computational efficiency. Nonetheless, the capabilities of theautoencoder module to preserve local dependencies should be improved to realize this potential. For the currentcase study, the custom model architecture was capable of conducting the simulation in the order of secondsafter a day of training, which had taken one week on HPC with the conventional CFD approach for the samenumber of droplets (200,000 trajectories).
Three decades of vulnerability research have generated a complex and growing body of *** concept of vulnerability,as well as its implementation in vulnerability assessments,is used in various disciplines and ***,a mul...
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Three decades of vulnerability research have generated a complex and growing body of *** concept of vulnerability,as well as its implementation in vulnerability assessments,is used in various disciplines and ***,a multitude of ideas and frameworks about how to conceptualize and measure vulnerability *** provide a structured representation of vulnerability,we have set up an ontology-based semantic wiki for reviewing and representing vulnerability assessments(***).Based on a survey of 55 vulnerability assessment studies,we first developed an ontology as an explicit reference system for describing vulnerability *** ontology was then implemented in a semantic wiki which allows for the classification and annotation of vulnerability *** resulting semantic wiki,Vu Wiki,does not aim at‘‘synthesizing’’a holistic and overarching model of vulnerability,but at(1)providing—both scientists and practitioners—with a uniform ontology as a reference system;(2)providing easy and structured access to the knowledge field of vulnerability assessments with the possibility for any user to retrieve assessments using specific research criteria;and(3)serving as a collaborative knowledge platform that allows for the active participation of those generating and using the knowledge represented in the vulnerability wiki.
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