TY - JOUR A1 - Tippkötter, Nils A1 - Roth, Jasmine T1 - Purified Butanol from Lignocellulose – Solvent‐Impregnated Resins for an Integrated Selective Removal JF - Chemie Ingenieur Technik N2 - In traditional microbial biobutanol production, the solvent must be recovered during fermentation process for a sufficient space-time yield. Thermal separation is not feasible due to the boiling point of n-butanol. As an integrated and selective solid-liquid separation alternative, solvent impregnated resins (SIRs) were applied. Two polymeric resins were evaluated and an extractant screening was conducted. Vacuum application with vapor collection in fixed-bed column as bioreactor bypass was successfully implemented as butanol desorption step. In course of further increasing process economics, fermentation with renewable lignocellulosic substrates was conducted using Clostridium acetobutylicum. Utilization of SIR was shown to be a potential strategy for solvent removal from fermentation broth, while application of a bypass column allows for product removal and recovery at once. KW - Biofuel KW - Biorefinery KW - Butanol KW - Clostridium acetobutylicum KW - Lignocellulose Y1 - 2020 U6 - https://doi.org/10.1002/cite.202000200 SN - 1522-2640 N1 - Corresponding author: Nils Tippkötter VL - 92 IS - 11 SP - 1741 EP - 1751 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Raffeis, Iris A1 - Adjei-Kyeremeh, Frank A1 - Vroomen, Uwe A1 - Westhoff, Elmar A1 - Bremen, Sebastian A1 - Hohoi, Alexandru A1 - Bührig-Polaczek, Andreas T1 - Qualification of a Ni-Cu alloy for the laser powder bed fusion process (LPBF): Its microstructure and mechanical properties JF - Applied Sciences N2 - As researchers continue to seek the expansion of the material base for additive manufacturing, there is a need to focus attention on the Ni–Cu group of alloys which conventionally has wide industrial applications. In this work, the G-NiCu30Nb casting alloy, a variant of the Monel family of alloys with Nb and high Si content is, for the first time, processed via the laser powder bed fusion process (LPBF). Being novel to the LPBF processes, optimum LPBF parameters were determined, and hardness and tensile tests were performed in as-built conditions and after heat treatment at 1000 °C. Microstructures of the as-cast and the as-built condition were compared. Highly dense samples (99.8% density) were achieved after varying hatch distance (80 µm and 140 µm) with scanning speed (550 mm/s–1500 mm/s). There was no significant difference in microhardness between varied hatch distance print sets. Microhardness of the as-built condition (247 HV0.2) exceeded the as-cast microhardness (179 HV0.2.). Tensile specimens built in vertical (V) and horizontal (H) orientations revealed degrees of anisotropy and were superior to conventionally reported figures. Post heat treatment increased ductility from 20% to 31% (V), as well as from 16% to 25% (H), while ultimate tensile strength (UTS) and yield strength (YS) were considerably reduced. Y1 - 2020 U6 - https://doi.org/10.3390/app10103401 SN - 2076-3417 N1 - Special Issue Materials Development by Additive Manufacturing Techniques VL - 10 IS - Art. 3401 SP - 1 EP - 15 PB - MDPI CY - Basel ER - TY - CHAP A1 - Iomdina, Elena N. A1 - Kiseleva, Anna A. A1 - Kotliar, Konstantin A1 - Luzhnov, Petr V. T1 - Quantification of Choroidal Blood Flow Using the OCT-A System Based on Voxel Scan Processing T2 - Proceedings of the International Conference on Biomedical Innovations and Applications- BIA 2020 N2 - The paper presents a method for the quantitative assessment of choroidal blood flow using an OCT-A system. The developed technique for processing of OCT-A scans is divided into two stages. At the first stage, the identification of the boundaries in the selected portion was performed. At the second stage, each pixel mark on the selected layer was represented as a volume unit, a voxel, which characterizes the region of moving blood. Three geometric shapes were considered to represent the voxel. On the example of one OCT-A scan, this work presents a quantitative assessment of the blood flow index. A possible modification of two-stage algorithm based on voxel scan processing is presented. Y1 - 2020 SN - 978-1-7281-7073-2 U6 - https://doi.org/10.1109/BIA50171.2020.9244511 N1 - International Conference on Biomedical Innovations and Applications, Varna, Bulgaria, September 24 - 27, 2020 SP - 41 EP - 44 PB - IEEE CY - New York, NY ER - TY - CHAP A1 - Lorenz, Imke-Sophie A1 - Altherr, Lena A1 - Pelz, Peter F. T1 - Resilience enhancement of critical infrastructure – graph-theoretical resilience analysis of the water distribution system in the German city of Darmstadt T2 - 14th WCEAM Proceedings N2 - Water suppliers are faced with the great challenge of achieving high-quality and, at the same time, low-cost water supply. Since climatic and demographic influences will pose further challenges in the future, the resilience enhancement of water distribution systems (WDS), i.e. the enhancement of their capability to withstand and recover from disturbances, has been in particular focus recently. To assess the resilience of WDS, graph-theoretical metrics have been proposed. In this study, a promising approach is first physically derived analytically and then applied to assess the resilience of the WDS for a district in a major German City. The topology based resilience index computed for every consumer node takes into consideration the resistance of the best supply path as well as alternative supply paths. This resistance of a supply path is derived to be the dimensionless pressure loss in the pipes making up the path. The conducted analysis of a present WDS provides insight into the process of actively influencing the resilience of WDS locally and globally by adding pipes. The study shows that especially pipes added close to the reservoirs and main branching points in the WDS result in a high resilience enhancement of the overall WDS. KW - Resilient infrastructure KW - Resilience assessment KW - Resilience metric graph theory KW - Water distribution system KW - Case study Y1 - 2020 SN - 978-3-030-64228-0 SN - 978-3-030-64227-3 U6 - https://doi.org/10.1007/978-3-030-64228-0_13 N1 - 14th WCEAM Proceedings. World Congress on Engineering Asset Management, 28-31 July 2019, Singapore Part of the Lecture Notes in Mechanical Engineering book series (LNME) SP - 137 EP - 149 PB - Springer CY - Cham ER - TY - JOUR A1 - Streese, Lukas A1 - Kotliar, Konstantin A1 - Deiseroth, Arne A1 - Infanger, Denis A1 - Gugleta, Konstantin A1 - Schmaderer, Christoph A1 - Hanssen, Henner T1 - Retinal endothelial function in cardiovascular risk patients: A randomized controlled exercise trial JF - Scandinavian Journal of Medicine and Science in Sports N2 - The aim of this study was to investigate, for the first time, the effects of high-intensity interval training (HIIT) on retinal microvascular endothelial function in cardiovascular (CV) risk patients. In the randomized controlled trial, middle-aged and previously sedentary patients with increased CV risk (aged 58 ± 6 years) with ≥ two CV risk factors were randomized into a 12-week HIIT (n = 33) or control group (CG, n = 36) with standard physical activity recommendations. A blinded examiner measured retinal endothelial function by flicker light-induced maximal arteriolar (ADmax) and venular (VDmax) dilatation as well as the area under the arteriolar (AFarea) and venular (VFarea) flicker curve using a retinal vessel analyzer. Standardized assessments of CV risk factors, cardiorespiratory fitness, and retinal endothelial function were performed before and after HIIT. HIIT reduced body mass index, fat mass, and low-density lipoprotein and increased muscle mass and peak oxygen uptake (VO2peak). Both ADmax (pre: 2.7 ± 2.1%, post: 3.0 ± 2.2%, P = .018) and AFarea (pre: 32.6 ± 28.4%*s, post: 37.7 ± 30.6%*s, P = .016) increased after HIIT compared with CG (ADmax, pre: 3.2 ± 1.8%, post: 2.9 ± 1.8%, P = .254; AFarea, pre: 41.6 ± 28.5%*s, post: 37.8 ± 27.0%*s, P = .186). Venular function remained unchanged after HIIT. There was a significant association between ∆-change VO2peak and ∆-changes ADmax and AFarea (P = .026, R² = 0.073; P = .019, R² = 0.081, respectively). 12-weeks of HIIT improved retinal endothelial function in middle-aged patients with increased CV risk independent of the reduction in classical CV risk factors. Exercise has the potential to reverse or at least postpone progression of small vessel disease in older adults with increased CV risk under standard medication. Dynamic retinal vessel analysis seems to be a sensitive tool to detect treatment effects of exercise interventions on retinal microvascular endothelial function in middle-aged individuals with increased CV risk. Y1 - 2020 U6 - https://doi.org/10.1111/sms.13560 SN - 1600-0838 VL - 30 IS - 2 SP - 272 EP - 280 PB - Wiley CY - Oxford ER - TY - JOUR A1 - Ramoshaba, Nthai E. A1 - Huisman, Hugo W. A1 - Lammertyn, Leandi A1 - Kotliar, Konstantin A1 - Schutte, Aletta E. A1 - Smith, Wayne T1 - Retinal microvasculature and masked hypertension in young adults: the African-PREDICT study JF - Hypertension Research N2 - Masked hypertension is known to induce microvascular complications. However, it is unclear whether early microvascular changes are already occurring in young, otherwise healthy adults. We therefore investigated whether retinal microvascular calibers and acute responses to a flicker stimulus are related to masked hypertension. We used the baseline data of 889 participants aged 20–30 years who were taking part in the African Prospective study on the Early Detection and Identification of Cardiovascular Disease and Hypertension. Clinic and 24-h ambulatory blood pressure were measured. The central retinal artery equivalent (CRAE) and central retinal vein equivalent were calculated from fundus images, and retinal vessel dilation was determined in response to flicker light-induced provocation. A smaller CRAE was observed in those with masked hypertension vs. those with normotension (157.1 vs. 161.2 measuring units, P < 0.001). In forward multivariable-adjusted regression analysis, only CRAE was negatively related to masked hypertension [adjusted R² = 0.267, β = −0.097 (95% CI = −0.165; −0.029), P = 0.005], but other retinal microvascular parameters were not associated with masked hypertension. In multivariable logistic regression analyses, masked hypertension [OR = 2.333, (95% CI = 1.316; 4.241), P = 0.004] was associated with a narrower CRAE. In young healthy adults, masked hypertension was associated with retinal arteriolar narrowing, thereby reflecting early microvascular alterations known to predict cardiovascular outcomes in later life. Y1 - 2020 U6 - https://doi.org/10.1038/s41440-020-0487-0 SN - 1348-4214 IS - 43 SP - 1231 EP - 1238 PB - Springer Nature CY - Osaka ER - TY - JOUR A1 - Smith, Wayne A1 - Kotliar, Konstantin A1 - Lammertyn, Leandi A1 - Ramoshaba, Nthai E. A1 - Vilser, Walthard A1 - Huisman, Hugo W. A1 - Schutte, Aletta E. T1 - Retinal vessel caliber and caliber responses in true normotensive black and white adults: The African-PREDICT study JF - Microvascular Research N2 - Purpose Globally, a detrimental shift in cardiovascular disease risk factors and a higher mortality level are reported in some black populations. The retinal microvasculature provides early insight into the pathogenesis of systemic vascular diseases, but it is unclear whether retinal vessel calibers and acute retinal vessel functional responses differ between young healthy black and white adults. Methods We included 112 black and 143 white healthy normotensive adults (20–30 years). Retinal vessel calibers (central retinal artery and vein equivalent (CRAE and CRVE)) were calculated from retinal images and vessel caliber responses to flicker light induced provocation (FLIP) were determined. Additionally, ambulatory blood pressure (BP), anthropometry and blood samples were collected. Results The groups displayed similar 24 h BP profiles and anthropometry (all p > .24). Black participants demonstrated a smaller CRAE (158 ± 11 vs. 164 ± 11 MU, p < .001) compared to the white group, whereas CRVE was similar (p = .57). In response to FLIP, artery maximal dilation was greater in the black vs. white group (5.6 ± 2.1 vs. 3.3 ± 1.8%; p < .001). Conclusions Already at a young age, healthy black adults showed narrower retinal arteries relative to the white population. Follow-up studies are underway to show if this will be related to increased risk for hypertension development. The reason for the larger vessel dilation responses to FLIP in the black population is unclear and warrants further investigation. Y1 - 2020 U6 - https://doi.org/10.1016/j.mvr.2019.103937 SN - 0026-2862 VL - 128 IS - Article 103937 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Sattler, Johannes, Christoph A1 - Röger, Marc A1 - Schwarzbözl, Peter A1 - Buck, Reiner A1 - Macke, Ansgar A1 - Raeder, Christian A1 - Göttsche, Joachim T1 - Review of heliostat calibration and tracking control methods JF - Solar Energy N2 - Large scale central receiver systems typically deploy between thousands to more than a hundred thousand heliostats. During solar operation, each heliostat is aligned individually in such a way that the overall surface normal bisects the angle between the sun’s position and the aim point coordinate on the receiver. Due to various tracking error sources, achieving accurate alignment ≤1 mrad for all the heliostats with respect to the aim points on the receiver without a calibration system can be regarded as unrealistic. Therefore, a calibration system is necessary not only to improve the aiming accuracy for achieving desired flux distributions but also to reduce or eliminate spillage. An overview of current larger-scale central receiver systems (CRS), tracking error sources and the basic requirements of an ideal calibration system is presented. Leading up to the main topic, a description of general and specific terms on the topics heliostat calibration and tracking control clarifies the terminology used in this work. Various figures illustrate the signal flows along various typical components as well as the corresponding monitoring or measuring devices that indicate or measure along the signal (or effect) chain. The numerous calibration systems are described in detail and classified in groups. Two tables allow the juxtaposition of the calibration methods for a better comparison. In an assessment, the advantages and disadvantages of individual calibration methods are presented. Y1 - 2020 U6 - https://doi.org/10.1016/j.solener.2020.06.030 VL - 207 SP - 110 EP - 132 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Golland, Alexander T1 - Rezension zu: Auernhammer – DSGVO/BDSG, Kommentar (7. Auflage, 2020) JF - DSB Datenschutz-Berater Y1 - 2020 SN - 0170-7256 N1 - Rezensiertes Werk: Auernhammer – Datenschutz-Grundverordnung, Bundesdatenschutzgesetz und Nebengesetze. Kommentar, 7. Auflage, Köln 2020 VL - 44 IS - 10 SP - 260 PB - DFV Mediengruppe CY - Frankfurt a.M. ER - TY - JOUR A1 - Golland, Alexander T1 - Rezension zu: Gabel/Heinrich/Kiefner – Rechtshandbuch Cyber-Security (2019) JF - K&R Kommunikation & Recht Y1 - 2020 SN - 1434-6354 IS - 6 SP - VII ER - TY - JOUR A1 - Golland, Alexander T1 - Rezension zu: Hansen-Oest – Datenschutzbeauftragte (2020) JF - DSB Datenschutz-Berater Y1 - 2020 SN - 0170-7256 VL - 44 IS - 9 SP - 228 PB - DFV Mediengruppe CY - Frankfurt a.M. ER - TY - JOUR A1 - Golland, Alexander T1 - Rezension zu: Kipker – Rechtshandbuch Cybersecurity (2020) JF - DSB Datenschutz-Berater Y1 - 2020 SN - 0170-7256 VL - 44 IS - 7-8 SP - 192 PB - DFV Mediengruppe CY - Frankfurt a.M. ER - TY - JOUR A1 - Golland, Alexander T1 - Rezension zu: Spiecker gen. Döhmann/Bretthauer – Dokumentation zum Datenschutz (2019) JF - DSB Datenschutz-Berater Y1 - 2020 SN - 0170-7256 VL - 44 IS - 2 SP - 52 EP - 52 PB - DFV Mediengruppe CY - Frankfurt a.M. ER - TY - JOUR A1 - Golland, Alexander T1 - Rezension zu: Sydow - Bundesdatenschutzgesetz, Handkommentar (2020) JF - DSB Datenschutz-Berater Y1 - 2020 SN - 0170-7256 VL - 44 IS - 3 SP - 76 EP - 76 PB - DFV Mediengruppe CY - Frankfurt a.M. ER - TY - JOUR A1 - Valero, Daniel A1 - Chanson, Hubert A1 - Bung, Daniel Bernhard T1 - Robust estimators for free surface turbulence characterization: A stepped spillway application JF - Flow Measurement and Instrumentation N2 - Robust estimators are parameters insensitive to the presence of outliers. However, they presume the shape of the variables’ probability density function. This study exemplifies the sensitivity of turbulent quantities to the use of classic and robust estimators and the presence of outliers in turbulent flow depth time series. A wide range of turbulence quantities was analysed based upon a stepped spillway case study, using flow depths sampled with Acoustic Displacement Meters as the flow variable of interest. The studied parameters include: the expected free surface level, the expected fluctuation intensity, the depth skewness, the autocorrelation timescales, the vertical velocity fluctuation intensity, the perturbations celerity and the one-dimensional free surface turbulence spectrum. Three levels of filtering were utilised prior to applying classic and robust estimators, showing that comparable robustness can be obtained either using classic estimators together with an intermediate filtering technique or using robust estimators instead, without any filtering technique. Y1 - 2020 U6 - https://doi.org/10.1016/j.flowmeasinst.2020.101809 SN - 0955-5986 VL - 76 IS - Art. 101809 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gaigall, Daniel T1 - Rothman–Woodroofe symmetry test statistic revisited JF - Computational Statistics & Data Analysis N2 - The Rothman–Woodroofe symmetry test statistic is revisited on the basis of independent but not necessarily identically distributed random variables. The distribution-freeness if the underlying distributions are all symmetric and continuous is obtained. The results are applied for testing symmetry in a meta-analysis random effects model. The consistency of the procedure is discussed in this situation as well. A comparison with an alternative proposal from the literature is conducted via simulations. Real data are analyzed to demonstrate how the new approach works in practice. Y1 - 2020 U6 - https://doi.org/10.1016/j.csda.2019.106837 SN - 0167-9473 VL - 2020 IS - 142 SP - Artikel 106837 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Finkenberger, Isabel Maria A1 - Veil, Katja T1 - Räumliche Transformation JF - RaumPlanung : Fachzeitschrift für räumliche Planung und Forschung Y1 - 2020 SN - 0176-7534 VL - 205 IS - 1 SP - 6 EP - 11 PB - IfR (Informationskreis für Raumplanung) CY - Dortmund ER - TY - JOUR A1 - Fiedler, Thomas M. A1 - Ladd, Mark E. A1 - Clemens, Markus A1 - Bitz, Andreas T1 - Safety of subjects during radiofrequency exposure in ultra-high-field magnetic resonance imaging JF - IEEE Letters on Electromagnetic Compatibility Practice and Applications N2 - Magnetic resonance imaging (MRI) is one of the most important medical imaging techniques. Since the introduction of MRI in the mid-1980s, there has been a continuous trend toward higher static magnetic fields to obtain i.a. a higher signal-to-noise ratio. The step toward ultra-high-field (UHF) MRI at 7 Tesla and higher, however, creates several challenges regarding the homogeneity of the spin excitation RF transmit field and the RF exposure of the subject. In UHF MRI systems, the wavelength of the RF field is in the range of the diameter of the human body, which can result in inhomogeneous spin excitation and local SAR hotspots. To optimize the homogeneity in a region of interest, UHF MRI systems use parallel transmit systems with multiple transmit antennas and time-dependent modulation of the RF signal in the individual transmit channels. Furthermore, SAR increases with increasing field strength, while the SAR limits remain unchanged. Two different approaches to generate the RF transmit field in UHF systems using antenna arrays close and remote to the body are investigated in this letter. Achievable imaging performance is evaluated compared to typical clinical RF transmit systems at lower field strength. The evaluation has been performed under consideration of RF exposure based on local SAR and tissue temperature. Furthermore, results for thermal dose as an alternative RF exposure metric are presented. Y1 - 2020 SN - 2637-6423 U6 - https://doi.org/10.1109/LEMCPA.2020.3029747 VL - 2 IS - 3 SP - 1 EP - 8 PB - IEEE CY - New York, NY ER - TY - CHAP A1 - Laack, Walter van T1 - Schnittstelle Tod: Aufbruch oder Ende - Kontakte oder Hirngespinste? N2 - Tagungsbeiträge des 6. Europäischen Seminars am 09. November 2019 in Aachen zum Thema Nahtoderfahrungen mit dem Serientitel: "Schnittstelle Tod" Y1 - 2020 SN - 978-3-936624-51-9 N1 - 6. „Jour Fixe“ im Dreiländereck zum Themenkreis „Nahtoderfahrungen (NTE)“: Schnittstelle Tod „Aufbruch oder Ende – Kontakte oder Hirngespinste?“, 9. November 2019, Aachen PB - van Laack GmbH CY - Aachen ER - TY - PAT A1 - Hojdis, Nils A1 - Recker, Carla T1 - Schwefelvernetzte Kautschukmischung für Fahrzeugreifen enthaltend Carbon Nanotubes (cnt), Fahrzeugreifen, Der Die schwefelvernetzte Kautschukmischung aufweist, sowie Verfahren zur Herstellung der schwefelvernetzten Kautschukmischung enthaltend Cnt Y1 - 2020 N1 - Patent EP000003625288A1 25.03.2020 auch veröffentlicht unter CN110678508A; DE102017208137A1; WO2018210471A1 ER -