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Hybrid Additive Manufacturing of Forming Tools

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Automotive Innovation 2023年第3期6卷 311-323页

作者： Hamed Dardaei Joghan Ramona Holker‑jager Anna Komodromos A.Erman Tekkaya Institute of Forming Technology and Lightweight Components(IUL) TU Dortmund UniversityBaroper Stra.e 30344227 DortmundGermany

Additive manufacturing(AM)is widely used in the automotive industry and has been expanded to include aerospace,marine,and *** flexibility and the possibility of manufacturing complex parts in AM motivate the integration of additive manu-facturing with classical forming technologies,which can improve tooling concepts and reduce *** study presents three applications of this ***,the possibility of successful utilization of selective laser melting for manufacturing extrusion tools with complex cooling channels and paths for thermocouples is reported,leading to significantly reduced inner die temperatures during the extrusion ***,sheet lamination is integrated with laser metal deposition(LMD)to manufacture deep-drawing *** results are achieved in reducing the stair step effect,which is the main challenge in sheet lamination,by LMD and following post-processing such as milling,ball burnishing,and laser *** new manufacturing route shows that LMD can economically and efficiently reduce the stair step effect and omit the hardening step from the conventional manufacturing process ***,LMD is used to manufacture a hot stamping punch with improved surface roughness by ball burnishing and near-surface complex cooling *** experimental results show that the manufactured punch has lower temperatures during hot stamping compared with the conventionally manufactured *** study shows the successful integration of AM processes with classical forming processes.

关键词： Additive manufacturing Laser metal deposition Selective laser melting Rapid tooling Forming tool Layer laminated manufacturing

The stability of carbon from a maize-derived hydrochar as a function of fractionation and hydrothermal carbonization temperature in a Podzol

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Biochar 2022年第1期4卷 315-326页

作者： Megan de jager Frank Schröter michae. Wark Luise Giani Institut Für Biologie Und Umweltwissenschaften Carl Von Ossietzky Univer-sitätOldenburgGermany Institut Für Chemie Carl Von Ossietzky UniversitätOldenburgGermany

Hydrochar(HC)produced by the hydrothermal carbonization(HTC)of typically wet biomass is generally considered to be less effective for carbon(C)sequestration in soils compared to biochar(BC)by pyrolysis,due to a higher content of more easily decomposable *** the recalcitrance of HC is suggested to improve with increasing HTC production temperature,the way it interacts and becomes associated with soil organic matter(SOM)fractions of different stabilities against decomposition,may also influence its effectiveness for C sequestration in *** that respect,this study aimed to verify the potential of HCs from maize silage produced at different HTC temperatures(190,210 and 230℃)for C sequestration in a HC-amended sandy loam *** do this,we conducted a pot trial experiment and traced the fate of HC-derived C(HC-C)within different SOM fractions,namely the free-and occluded particulate organic matter(POMF and POMO,respectively)fractions and that comprising organic matter(OM)bound to clays(OMCl).Approx.1 year after applying 5%of the different HTC temperature HCs to the soil,the SOM fractions were isolated by density fractionation for each HC treatment(HC190,HC210 and HC230)and the control(absent of HC).All fractions and the HCs were analyzed for organic C(OC)content and isotopic signatures(δ^(13)C).From the δ^(13)C signatures,the amount of HC-C and native soil organic carbon(SOC)within each fraction was *** C contents and decreased H/C and O/C ratios were observed with increasing HTC production temperatures,which sug-gests a lower stability for the low temperature *** ca.1 year,a loss of~20-23%of the bulk soil TOC was found in the HC-amended *** POMF fraction of the HC-amended soils showed losses of 68-81%HC-C and 52-72%native SOC,which may be due to a positive priming effect caused by HC *** POM_(O) and OM_(Cl) fractions of the HC-amended soils contained more OC than the control,indicating the integration of HC-C together wi

关键词： Hydrochar Carbon sequestration Carbon stabilization Soil organic matter fractions Soil density fractionation δ^(13)C analysis

Finding middle ground:Flow regimes designed for salmon and energy value

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Water Biology and Security 2023年第3期2卷 19-29页

作者： Henriette I.jager Rocio Uria-Martinez Oak Ridge National Laboratory Oak RidgeTN37831-6038USA

In regulated rivers,shaping seasonal flows to recover species at risk depends on understanding when to expect conflicts with competing water users and when their interests are ***-objective optimization can be used to reveal such conflicts and *** species are involved,multi-objective optimization is challenged by the need to simulate complex species responses to flow ***,we addressed that challenge by developing a simplified salmon model(Quantus)that defines cohorts of salmon by the river section and time in which they were *** in these space-time cohorts are tracked from the time redds(nests)are constructed until the cohort exits the tributary en route to the *** this study,we modeled seasonal patterns in energy value and developed a Pareto-optimal frontier of seasonal flow patterns to maximize in-river salmon survival and hydropower *** flow regimes were characterized by two pulse flows varying in magnitude,timing,and duration and constrained by a total annual flow near the historical *** analysis revealed times when economic and salmon objectives were aligned and times when they *** flows that favored higher energy value were timed to meet demand during extreme *** salmon and hydropower objectives produced optimal flow regimes with pulse flows in early summer,but only solutions favoring hydropower value included high flows in *** favoring higher age-0 salmon survival provided an extended pulse flow in late winter/early spring,which suggests that access to productive floodplain habitat allowed faster growth and earlier out-migration and reduced the need for higher temperature-moderating flows later in *** flows were also higher among solutions favoring salmon over *** tools used to produce these results can help to design simplified seasonal flow regimes by revealing compromise solutions that satisfy both fish and energy producers

关键词： Optimization Environmental flows Reservoir release schedule Genetic algorithm Pareto optimal frontier Electricity price model Fall chinook salmon Pulse flows Multi-objective

Room temperature synthesis of perylene diimides facilitated by high amic acid solubility

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Organic Chemistry Frontiers 2022年第4期9卷 1090-1108页

作者： Markus C.Kwakernaak Marijn Koel Peter J.L.van den Berg Erik M.Kelder Wolter F.jager Department of Chemical Engineering Delft University of TechnologyVan der Maasweg 92629 HZ DelftThe Netherlands Department of Radiation Science and Technology/Reactor Institute Delft Delft University of Technology2629 JB DelftThe Netherlands

A novel protocol for the synthesis of perylene diimides(PDIs),by reacting perylene dianhydride(PDA)with aliphatic amines is *** conversions were obtained at temperatures between 20 and 60℃,using DBU as the base in DM... 详细信息

关键词： synthesis solubility anhydride

An investigation of the effects of hydrochar application rate on soil amelioration and plant growth in three diverse soils

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Biochar 2021年第3期3卷 349-365页

作者： Megan de jager Luise Giani Carl Von Ossietzky Universität Institut Für Biologie Und UmweltwissenschaftenOldenburgGermany

The hydrothermal carbonization(HTC)of biogas digestate alters the raw materials inherent characteristics to produce a carbon(C)-rich hydrochar(HC),with an improved suitability for soil *** studies report conflicting impacts of various HC application rates on soil properties and plant *** this study,the influence of HC application rate on soil improvement and plant growth aspects was investigated in three diverse soils(Chernozem,Podzol,and Gleysol).Pot trials were conducted in which all soils were amended with 5,10,20 and 30%(w/w)HC in quintuplicate,with two controls of pure soil(with and without plants,respectively)also *** to potting,soil samples were collected from all HC-amended soils and controls and analyzed for soil pH,plant available nutrients(PO4-P and K),and microbial activity using standard laboratory and statistical *** after potting,a 6-week seed germination experiment using Chinese cabbage was conducted to determine germination success,followed by a plant growth experiment of equal duration and plant species to determine biomass *** the end of the study(after a total plant growth period of 12 weeks),each pot was sampled and comparatively analyzed for the same soil properties as at the beginning of the *** pH shifted toward the pH of the HC(6.6)in all soils over the course of the study,but was most expressed in the 20%and 30%application rates,confirming the well-documented liming effect of *** addition of HC increased the PO4-P and K contents,particularly with 20%and 30%HC *** results are proposedly due to the large labile C fraction of the HC,which is easily degradable by *** rapid decomposition of this C fraction prompted the quick release of the HCs inherently high PO4-P and K content into the soil,and in turn,further stimulated microbial activity,until this fraction was essentially *** addition did not inhibit seed germination at any rate,presumabl

关键词： Biogas digestate Hydrochar application rate Soil improvement Nutrient availability Microbial activity

Shifts in hydropower operation to balance wind and solar will modify effects on aquatic biota

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Water Biology and Security 2022年第3期1卷 88-98页

作者： Henriette I.jager Thushara De Silva Rocio Uria-Martinez Brenda M.Pracheil Jordan Macknick Oak Ridge National Laboratory Oak RidgeTN37831-6038USA National Renewable Energy Laboratory GoldenCOUSA

To avoid negative consequences to freshwater biota from climate change,society must complete the transition from fossil to renewable electricity ***,temporal patterns in hydropower generation(and flow releases that affect aquatic biota)may change with increased wind and solar *** used power cost modeling to characterize current and future within-day and seasonal patterns in hydropower generation across the Eastern Interconnection in a wet and a dry *** to the baseline,future hydropower generation across the grid decreased during the day and increased before dawn and after *** a project level,such a pattern would suggest‘double peaking’operation(up-and down-ramping before dawn and after dusk,with lower releases midday).Variation in generation was higher in wet years than dry years,foreshadowing possible flow constraints on hydropower *** the grid scale,projected ramping rates were higher in all seasons.A review of the ecological literature suggests that these changes would shift the timing of invertebrate drift and elevate the risk of nest scouring during up-ramping and the risk of stranding or dewatering during down *** conditions may be moderated by increased *** for adapting to future shifts in the renewable portfolio range from re-regulation in reservoir cascades to providing flow refuge(structures and vegetation)below individual *** basin-scale operation can distribute peaking operation to maintain grid support while restricting local ramping at critical ecological *** addition,research to design hybrid renewable systems that add battery storage is needed to understand how we can mitigate future risks to aquatic communities while promoting the use of renewable *** study,which is among the first to examine ecological side-effects of the shift to renewable energy in freshwater ecosystems,lays out a path toward understanding and navigating changes to flow regime

关键词： Wind Solar Hydropower Hydropeaking Temporal niche Double peaking Ramping Stranding Dewatering PLEXOS

The influence of hydrochar from biogas digestate on soil improvement and plant growth aspects

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Biochar 2020年第2期2卷 177-194页

作者： Megan de jager michae. Rohrdanz Luise Giani Carl Von Ossietzky Universitat Institut für Biologie und UmweltwissenschaftenOldenburgGermany

Hydrochar(HC),produced by hydrothermal carbonization,offers technical advantages over biochar(BC)produced by pyrolysis,and is suitable for soil amelioration,carbon sequestration,and enhanced plant *** grain size has been shown to influence nutrient retention,microbial colonization and aggregate formation;however,similar research for HC is *** trials were conducted to investigate the influence of HC grain size[coarse(6.3-2 mm),medium(2-0.63 mm)and fine(50%in all *** effect on NO_(3)^(−)content was indeterminable,while there was little to no effect on biom

关键词： Hydrochar Soil improvement Grain size Plant available nutrients

Impact of Si on the high-temperature oxidation of AlCr(Si)N coatings

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Journal of Materials Science & Technology 2022年第5期100卷 91-100页

作者： Nikolaus jager michae. Meindlhumer Michal Zitek Stefan Spor Hynek Hruby Farwah Nahif Jaakko Julin Martin Rosenthal Jozef Keckes Christian Mitterer Rostislav Daniel Christian Doppler Laboratory for Advanced Synthesis of Novel Multifunctional Coatings at the Department of Materials Science Montanuniversität LeobenAustria voestalpine eifeler Vacotec GmbH DüsseldorfGermany Institute of Ion Beam Physics and Materials Research Helmholtz-Zentrum Dresden-RossendorfDresdenGermany Department of Physics University of JyvaskylaFinland European Synchrotron Radiation Facility GrenobleFrance Erich Schmid Institute for Materials Science Austrian Academy of SciencesAustria Department of Materials Science Montanuniversität LeobenAustria

The resistance of wear protective coatings against oxidation is crucial for their use at high ***,three nanocomposite AlCr(Si)N coatings with a fixed Al/Cr atomic ratio of 70/30 and a varying Si-content of 0 at.%,2.5 at.% and 5 at.% were analyzed by differential scanning calorimetry,thermogravimetric analysis and X-ray in order to understand the oxidation behavior depending on their ***,a partially oxidized AlCrSiN coating with 5 at.%Si on a sapphire substrate was studied across the coating thickness by depth-resolved cross-sectional X-ray nanodiffraction and scanning trans-mission electron microscopy to investigate the elemental composition,morphology,phases and residual stress evolution of the oxide scale and the non-oxidized coating *** results reveal enhanced oxidation properties of the AlCr(Si)N coatings with increasing Si-content,as demonstrated by a retarded onset of oxidation to higher temperatures from 1100℃ for AlCrN to 1260℃ for the Si-containing coatings and a simultaneous deceleration of the oxidation *** annealing of the AlCrSiN sample with5 at.%Si at an extraordinary high temperature of 1400℃ for 60 min in ambient air,three zones developed throughout the coating strongly differing in their composition and structure:(i)a dense oxide layer comprising an Al-rich and a Cr-rich zone formed at the very top,followed by(ii)a fine-grained transition zone with incomplete oxidation and(iii)a non-oxidized zone with a porous *** varying elemental composition of these zones is furthermore accompanied by micro-structural variations and a complex residual stress development revealed by cross-sectional X-ray *** results provide a deeper understanding of the oxidation behavior of AlCr(Si)N coatings depending on their Si-content and the associated elemental,microstructural and residual stress evolution during high-temperature oxidation.

关键词： AlCrSiN Nanocomposite Cathodic arc Oxidation behaviour Cross-sectional X-ray nanodiffraction

Avoiding experimental bias by systematic antibody validation

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Neural Regeneration Research 2016年第7期11卷 1079-1080页

作者： Sara B.jager Christian Bjerggaard Vaegter Department of Biomedicine & DANDRITE-Danish Research Institute of Translational Neuroscience Aarhus University

Antibodies are valued reagents in most modern laboratories and indispensable for many *** can be utilized in a wide range of experimental setups designed to elucidate various scientific *** our laboratory,antibodies a... 详细信息

关键词： indispensable questions furthermore utilized elucidate localization validation laboratories necessity giving