Simulating river flow velocity on global scale

Flow velocity in rivers has a major impact on residence time of water and thus on high and low water as well as on water quality. For global scale hydrological modeling only very limited information is available for simulating flow velocity. Based on the Manning-Strickler equation, a simple algorithm to model temporally and spatially variable flow velocity was developed with the objective of improving flow routing in the global hydrological model of Water- GAP. An extensive data set of flow velocity measurements in US rivers was used to test and to validate the algorithm before integrating it into WaterGAP. In this test, flow velocity was calculated based on measured discharge and compared to measured velocity. Results show that flow velocity can be modeled satisfactorily at selected river cross sections. It turned out that it is quite sensitive to river roughness, and the results can be optimized by tuning this parameter. After the validation of the approach, the tested flow velocity algorithm has been implemented into the WaterGAP model. A final validation of its effects on the model results is currently performed

Untersuchungen an Quinquethiophenen zur Verwendung als Donator in Organischen Solarzellen

Organische Photovoltaik könnte zukünftig eine Möglichkeit zur Energiegewinnung aus erneuerbaren Energiequellen darstellen. Der Vorteil besteht hier vor allen Dingen in dem Potential einer sehr kostengünstigen Herstellung, zum Beispiel einer Produktion im Rolle-zu-Rolle-Verfahren, welche so auf flexiblen Substraten wie beispielsweise Folien erfolgen kann. Obwohl die Materialkosten gering sind, ist bis zu einer Kommerzialisierung Organischer Solarzellen unter anderem eine Erhöhung ihrer Leistungseffizienz notwendig. Vorzugsweise sollten in Organischen Solarzellen Donator- und Akzeptormaterialien verwendet werden, deren Absorptionsspektren und Energieniveaus ideal aufeinander abgestimmt sind, da so zum Beispiel hohe Leerlaufspannungen erreicht werden können. Zusätzlich können hohe Absorptionskoeffizienten der Materialien über einen großen spektralen Bereich zu hohen Stromdichten in diesen photovoltaischen Bauelementen führen. In dieser Arbeit werden neuartige Quinquethiophene als Donatormaterial in Organischen Solarzellen untersucht, welche als Grundeinheit aus fünf Thiophenringen sowie Dicyanovinylendgruppen und Alkylseitenketten bestehen. Die untersuchten Materialien besitzen einen hohen Absorptionskoeffizienten und erreichten auf Grund des hohen Ionisationspotentials hohe Leerlaufspannungen in Organischen Solarzellen unter Verwendung des Fullerens C60 als Akzeptor. Gleichzeitig tritt eine effiziente Trennung der Exzitonen an der Akzeptor-Donator-Grenzfläche auf. Jedoch stellt das hohe Ionisationspotential der Quinquethiophene spezielle Anforderungen an die weitere Solarzellenstruktur. Innerhalb dieser Arbeit wird gezeigt, dass ein Unterschied von eingebauter Spannung und Leerlaufspannung die Form der Solarzellen-Kennlinie entscheidend beeinflusst und eine S-Form in der Nähe der Leerlaufspannung erzeugen kann. Die eingebaute Spannung wird hierbei durch die Kontaktierung der photoaktiven Schichten bestimmt. Eine Erhöhung der eingebauten Spannung der Solarzelle kann durch eine entsprechende Materialwahl erreicht werden. So wird in dieser Arbeit gezeigt, dass Organische Solarzellen basierend auf diesen Quinquethiophenen ohne energetische Barrieren für freie Ladungsträger innerhalb des Bauelements keine S-Form der Kennlinie aufweisen. Ebenfalls wird der Einfluss der unterschiedlichen Quinquethiophenderivate auf die Solarzellen-Charakteristik untersucht. Hierbei wird gezeigt, dass die Länge der Alkylseitenketten einen Einfluss auf die Löcherinjektion sowie die Löcherbeweglichkeit auf dem Oligothiophen hat, welches unter anderem auch die Form der Strom-Spannungs-Kennlinie beeinflusst. Abschließend wird die Möglichkeit der Verwendung dieser Materialklasse in Tandemsolarzellen gezeigt sowie der Vergleich von zwei unterschiedlichen Anodenmaterialien, beides wichtige Aspekte für eine kommerzielle Umsetzung

The global land water storage data set release 2 (GLWS2.0) derived via assimilating GRACE and GRACE-FO data into a global hydrological model

We describe the new global land water storage data set GLWS2.0, which contains total water storage anomalies (TWSA) over the global land except for Greenland and Antarctica with a spatial resolution of 0.5{\deg}, covering the time frame 2003 to 2019 without gaps, and including uncertainty quantification. GLWS2.0 was derived by assimilating monthly GRACE/-FO mass change maps into the WaterGAP global hydrology model via the Ensemble Kalman filter, taking data and model uncertainty into account. TWSA in GLWS2.0 is then accumulated over several hydrological storage variables. In this article, we describe the methods and data sets that went into GLWS2.0, how it compares to GRACE/-FO data in terms of representing TWSA trends, seasonal signals, and extremes, as well as its validation via comparing to GNSS-derived vertical loading and its comparison with the NASA Catchment Land Surface Model GRACE Data Assimilation (CLSM-DA). We find that, in the global average over more than 1000 stations, GLWS2.0 fits better than GRACE/-FO to GNSS observations of vertical loading at short-term, seasonal, and long-term temporal bands. While some differences exist, overall GLWS2.0 agrees quite well with CLSM-DA in terms of TWSA trends and annual amplitudes and phases.Comment: Preprin

Implementation of School Media Concepts as an Occasion for Cooperation: A Multi-Perspective Analysis of Cooperation Processes between Lower Secondary Schools and the Supporting System of the Medienberatung NRW

In dem Beitrag wird vor dem Hintergrund der Transformationsprozesse der Digitalisierung und der damit einhergehenden Anforderungen an die institutionsübergreifende Zusammenarbeit zwischen Einzelschulen und dem Unterstützungssystem der Kompetenzteams der Medienberatung NRW als exemplarische Form der Kooperation zwischen Einzelschulen und Bildungsadministration analysiert. Entlang des Implementierungsprozesses schulischer Medienkonzepte, welche als zentrale Schulentwicklungsinstrumente für die Umsetzung digitalisierungsbezogener Schulentwicklungsprozesse gelten, wird mithilfe eines längsschnittlichen Fallstudiendesigns und eines Mixed-Methods-Ansatzes den Fragen nachgegangen, welche Gestaltungsformen sich in der Zusammenarbeit zeigen und welche Gelingensbedingungen und Herausforderungen diesem Prozess zugrunde liegen. Der Beitrag fasst die zentralen Untersuchungsergebnisse zusammen und leitet mögliche Implikationen für die Praxis ab.In this article, the cross-institutional cooperation between individual schools and the competence teams of the Medienberatung NRW are analysed as an exemplary form of cooperation between individual schools and the educational administration. This happens against the background of the transformation processes of digitalisation and the accompanying demands on individual schools. It is based on the implementation process of educational media concepts, which are regarded as core instruments of school development for the implementation of digitalisation-related processes of development in schools. Along this implementation process, a longitudinal case study design and a mixed-methods approach were used to investigate, which forms of cooperation emerge and which conditions for success and challenges determine this process. The paper summarises the key findings of the research and deduces possible implications to practice

Effects of Diode Laser, Gaseous Ozone, and Medical Dressings on Enterococcus faecalis Biofilms in the Root Canal Ex Vivo

The objective was to compare the antibacterial effects of adjunctive disinfection using diode laser and gaseous ozone compared to the medical dressings calcium hydroxide (Ca(OH)2) and chlorhexidine gel (CHX-Gel) on Enterococcus faecalis biofilms in human root canals ex vivo. Root canals of 180 human extracted teeth were infected by E. faecalis and divided into 3 main groups (G): G1, control; G2, instrumentation and irrigation using 0.9% NaCl; G3, instrumentation and irrigation using 1% NaOCl. In each main group, the following treatments were applied: gaseous ozone, diode laser, and medical dressings of Ca(OH)2 or CHX-Gel for 7 days (). Reduction of colony forming units (CFUs) inside the root canal of planktons and frequencies of adherent bacteria after treatment were calculated. Bacterial reduction was significantly affected by the irrigation protocol () and the disinfection method (), and a significant interaction between both factors could be observed (; ANOVA). In G3 (instrumentation using 1% NaOCl), no significant effect of disinfection methods could be demonstrated on planktonic bacteria (; ANOVA) and frequencies of adherent bacteria (; chi-square test). Instrumentation and irrigation using NaOCl combined with ozone or laser application resulted in comparable bacterial reduction on E. faecalis to the application of medical dressings

Apomorphine Is a Bimodal Modulator of TRPA1 Channels

ABSTRACT Apomorphine is a non-narcotic derivative of morphine, which acts as a dopamine agonist and is clinically used to treat "offstates" in patients suffering from Parkinson's disease. Adverse effects of apomorphine treatment include severe emesis and nausea, and ulceration and pain at the injection site. We wanted to test whether sensory transient receptor potential (TRP) channels are a molecular target for apomorphine. Here, we show that rTRPV1, rTRPV2, rTRPV3, and mTRPV4, as well as hTRPM8, and rTRPM3, which are expressed in dorsal root ganglion neurons, are insensitive toward apomorphine treatment. This also applied to the cellular redox sensor hTRPM2. On the contrary, human TRPA1 could be concentrationdependently modulated by apomorphine. Whereas the addition of apomorphine in the low micromolar range produced an irreversible activation of the channel, application of higher concentrations caused a reversible voltage-dependent inhibition of heterologously expressed TRPA1 channels, resulting from a reduction of single-channel open times. In addition, we provide evidence that apomorphine also acts on endogenous TRPA1 in cultured dorsal root ganglion neurons from rats and in the enterochromaffin model cell line QGP-1, from which serotonin is released upon activation of TRPA1. Our study shows that human TRPA1 is a target for apomorphine, suggesting that an activation of TRPA1 might contribute to adverse side effects such as nausea and painful injections, which can occur during treatment with apomorphine

Cerebrovascular Events in Suspected Sepsis: Retrospective Prevalence Study in Critically Ill Patients Undergoing Full-Body Computed Tomography

Purpose: This study aimed at retrospectively evaluating full-body computed tomography (CT) examinations for the prevalence of cerebrovascular events in patients with suspected sepsis treated in the intensive care unit (ICU). Methods: All full-body CT examinations, i.e., both cranial CT (cCT) and body CT including chest, abdomen and pelvis, for focus search in septic patients over a 12-months period were identified from three ICUs, using full-text search. From this retrospective cohort, we fully analyzed 278 cCT examinations for the occurrence of acute cerebral findings. All acute cerebrovascular events were independently reviewed by two blinded readers. Clinical and laboratory findings were extracted. The data were statistically analyzed using contingency tests. Results: In our population of patients with suspected sepsis, 10.8% (n = 30/278) were identified to have major cerebral events, including 7.2% (n = 20/278) major cerebrovascular events and 4.3% (n = 12/278) generalized parenchymal damage. 13.4% (n = 22/163) of patients with a severe coma as compared with non-severe coma, 4.4% (n = 3/68), showed a major cerebral event (p = 0.04). Patients referred from the cardiology/nephrology ICU ward showed major cerebral events in 16.3% (n = 22/135), as compared with 4.9% (n = 3/61) in patients from pulmonary ICU and 6.1% (n = 5/82) major cerebral events with surgical referral (p = 0.02). Conclusion: Our study provides further evidence that septic patients may suffer from cerebral events with relevance to their prognosis. Severe coma and the referring ward were associated with acute cerebral conditions. Full-body CT has the advantage of both detecting of septic foci and possibly identifying ischemic or hemorrhagic stroke in this vulnerable patient population

Multiscale simulation approach to predict the penetration depth of oil between chip and tool during orthogonal cutting of AISI 4140

Cooling lubricants in machining perform important tasks, from cooling and lubrication of the friction partners in contact to the removal of the separated chips. An essential, determining and largely unresolved question in relation to cooling lubricants in ma-chining is to what extent the coolant can get into the cutting zone. The aim of this paper is to address this question by using a multiscale approach to determine the penetration of the cooling lubricant gap. This is achieved by multiscale simulations by means of coupling the results of flow, structural and continuum mechanical simulations. Comparatively, the results of the simulated machining operation are compared with experimental orthogonal cutting tests of AISI 4140

Biological characterization of Poly-L-lactic acid (PLLA)/Hydroxyapatite (HA)/Bioglass (BG) composite scaffolds made by Thermally Induced Phase Separation (TIPS) hosting human Mesenchymal Stem Cells

In the last few years, Tissue Engineering has focused on the favourable effects that composite scaffolds have on cell adhesion, growth and differentiation. In fact, composite scaffolds, usually composed of a synthetic polymer supplemented with naturally occurring components, display superior mechanical properties and bioconductivity than scaffolds consisting of a single component. Hydroxyapatite (HA) is the major inorganic component of bones. Bioglass (BG) is known to exert stimulatory effects on cells by ion release and hence, could be also advantageous for Bone Tissue Engineering. Poly-L-lactic acid (PLLA) is a versatile synthetic polymer combinable with HA and BG. The aim of this work was to assess the effectiveness of PLLA/HA and PLLA/HA/BG 1393 composite scaffolds as suitable artificial Extracellular Matrix (ECM) for human Mesenchymal Stromal Cells (h-MSCs). In order to check if composite scaffolds are actually superior, a comparison was made between the scaffolds above mentioned and PLLA and PLLA/BG scaffolds. All four types of scaffolds (PLLA, PLLA/HA, PLLA/BG and PLLA/HA/BG) were manufactured in Palermo, at the University of Palermo, using the Thermally Induced Phase Separation (TIPS) technique, for which a PLLA/1,4-dioxane/water ternary solution was chosen. In composite scaffolds, HA and BG 1393 were added in the solution as powder phase. The temperature selected for promoting the phase separation was 30 °C and the residence time in the thermostatic bath was set to 80 minutes. The samples were then placed in a cooling bath at -20 °C for 15 minutes, in order to freeze the porous structure thus formed. With these process conditions, scaffolds with a porosity higher than 90% and a mean pore size of 100 μm were obtained. After subsequent washing and drying steps, the as-obtained cylindrical structures were cut in disk-shaped specimens with a diameter of 6 mm and a thickness of 1.5 mm. Before the seeding stage, scaffolds were sterilized in 70% ethanol solution, stored in Phosphate Buffered Saline (PBS) and finally soaked in h-MSCs culture medium. The seeding of h-MSCs occurred in a 96-well plate and monitoring analyses were carried out at time points of 48 hours and 8 days. Before used for seeding experiments, undifferentiated MSCs were characterized for a set of markers (CD34, CD44, CD45, CD90, CD105, Vimentin) to show their typical expression pattern before seeding. Multilineage differentiation potential was proven by adipogenic, osteogenic and chondrogenic differentiation. Life/dead assays, Haematoxylin/Eosin, Alcian blue and Alizarin red stainings were employed to verify cells viability, ECM synthesis, adhesion to the polymeric structure and migration into the scaffold. Cell proliferation was calculated from DNA content using CyQuant assay. h-MSCs expressed the typical markers, they were able to spread evenly on both upper and lower surfaces of all types of scaffold. The majority of the adhering cells survived on the scaffolds over the whole observation period. Scaffolds supplemented with HA revealed a higher seeded area compared with PLLA and BG alone. Furthermore, h-MSCs penetrated in mean 260 µm into the porous polymeric structure of all scaffolds. The next step will involve long time experiments with h-MSCs under osteogenic and non-osteogenic conditions in the same types of scaffolds. Successful osteogenic differentiation will be tested by monitoring osteogenic marker expression, e.g. type X collagen