CO2-brine-mineral Interfacial Reactions Coupled with Fluid Phase Flow

AbstractDue to their widespread occurrence and large capacities, deep geological saline formations are regarded as an important storage option for anthropogenic CO2. Injection of supercritical CO2 into such a formation will result in a multi-phase flow porous media system. Both the CO2 and brine phase compositions are influenced by multiphase flow and mass transport processes as well as by interfacial reactions (gas dissolution, water vaporization, mineral dissolution and precipitation). For a model based assessment of CO2 storage, most simulation codes apply an operator-splitting approach to solve the coupled problem, where multi-phase flow and geochemical reactions are handled by separate routines sequentially. This approach relies on two approximations: (I) the dissolution of CO2 in the brine, which is usually quantified by the multiphase flow routine by using an equation of state approach, is treated as instantaneous, and (II) the amount of CO2 consumed during geochemical reactions quantified by the reaction routine is small compared to the amount dissolved, as during geochemical reactions CO2 is not resupplied from the CO2 phase by dissolution.To investigate these two approximations, the multiphase flow and multi-component reactive transport simulator OpenGeoSys was extended and now allows to simulate mineral-brine as well as the brine-CO2 interface reactions either kinetically controlled or by using an equilibrium approach, and to account for the presence of a CO2 phase during brine-mineral reactions. The code is used here to investigate a simple gas-liquid-solid phase (CO2-H2O- CaCO3) system controlled by fast reaction rates. Batch reaction calculations are performed for the multiphase system at various temperature and pressure conditions for different initial CO2 saturations. Two methods of approximating the equilibrium state of the system by an operator splitting approach are compared. The first method determines the gas-liquid and solid-liquid equilibria in separate subsequent steps. At reservoir conditions relevant for storage of CO2 (323K, 100bar) and for high CO2 saturations the error in predicted CO2 concentrations in the liquid phase reaches up to -2%. This error can be reduced to less than -0.5% by the second method, where a conjoint gas-liquid-solid equilibrium is accounted for in the reaction calculations. Accordingly, the latter approach should preferably be employed in multiphase flow reactive transport modeling based on operator splitting techniques

Oscillating nonlinear large scale structure in growing neutrino quintessence

Growing Neutrino quintessence describes a form of dynamical dark energy that could explain why dark energy dominates the universe only in recent cosmological times. This scenario predicts the formation of large scale neutrino lumps which could allow for observational tests. We perform for the first time N-body simulations of the nonlinear growth of structures for cold dark matter and neutrino fluids in the context of Growing Neutrino cosmologies. Our analysis shows a pulsation - increase and subsequent decrease - of the neutrino density contrast. This could lead to interesting observational signatures, as an enhanced bulk flow in a situation where the dark matter density contrast only differs very mildly from the standard LCDM scenario. We also determine for the first time the statistical distribution of neutrino lumps as a function of mass at different redshifts. Such determination provides an essential ingredient for a realistic estimate of the observational signatures of Growing Neutrino cosmologies. Due to a breakdown of the non-relativistic Newtonian approximation our results are limited to redshifts z > 1.Comment: 17 pages, 1 table, 10 figures; MNRAS in pres

Treatment of Peritoneal Carcinomatosis by Targeted Delivery of the Radio-Labeled Tumor Homing Peptide 213Bi-DTPA-[F3]2 into the Nucleus of Tumor Cells

BACKGROUND: Alpha-particle emitting isotopes are effective novel tools in cancer therapy, but targeted delivery into tumors is a prerequisite of their application to avoid toxic side effects. Peritoneal carcinomatosis is a widespread dissemination of tumors throughout the peritoneal cavity. As peritoneal carcinomatosis is fatal in most cases, novel therapies are needed. F3 is a tumor homing peptide which is internalized into the nucleus of tumor cells upon binding to nucleolin on the cell surface. Therefore, F3 may be an appropriate carrier for alpha-particle emitting isotopes facilitating selective tumor therapies. PRINCIPAL FINDINGS: A dimer of the vascular tumor homing peptide F3 was chemically coupled to the alpha-emitter (213)Bi ((213)Bi-DTPA-[F3](2)). We found (213)Bi-DTPA-[F3](2) to accumulate in the nucleus of tumor cells in vitro and in intraperitoneally growing tumors in vivo. To study the anti-tumor activity of (213)Bi-DTPA-[F3](2) we treated mice bearing intraperitoneally growing xenograft tumors with (213)Bi-DTPA-[F3](2). In a tumor prevention study between the days 4-14 after inoculation of tumor cells 6x1.85 MBq (50 microCi) of (213)Bi-DTPA-[F3](2) were injected. In a tumor reduction study between the days 16-26 after inoculation of tumor cells 6x1.85 MBq of (213)Bi-DTPA-[F3](2) were injected. The survival time of the animals was increased from 51 to 93.5 days in the prevention study and from 57 days to 78 days in the tumor reduction study. No toxicity of the treatment was observed. In bio-distribution studies we found (213)Bi-DTPA-[F3](2) to accumulate in tumors but only low activities were found in control organs except for the kidneys, where (213)Bi-DTPA-[F3](2) is found due to renal excretion. CONCLUSIONS/SIGNIFICANCE: In conclusion we report that (213)Bi-DTPA-[F3](2) is a novel tool for the targeted delivery of alpha-emitters into the nucleus of tumor cells that effectively controls peritoneal carcinomatosis in preclinical models and may also be useful in oncology

Triangle network motifs predict complexes by complementing high-error interactomes with structural information

BackgroundA lot of high-throughput studies produce protein-protein interaction networks (PPINs) with many errors and missing information. Even for genome-wide approaches, there is often a low overlap between PPINs produced by different studies. Second-level neighbors separated by two protein-protein interactions (PPIs) were previously used for predicting protein function and finding complexes in high-error PPINs. We retrieve second level neighbors in PPINs, and complement these with structural domain-domain interactions (SDDIs) representing binding evidence on proteins, forming PPI-SDDI-PPI triangles.ResultsWe find low overlap between PPINs, SDDIs and known complexes, all well below 10%. We evaluate the overlap of PPI-SDDI-PPI triangles with known complexes from Munich Information center for Protein Sequences (MIPS). PPI-SDDI-PPI triangles have ~20 times higher overlap with MIPS complexes than using second-level neighbors in PPINs without SDDIs. The biological interpretation for triangles is that a SDDI causes two proteins to be observed with common interaction partners in high-throughput experiments. The relatively few SDDIs overlapping with PPINs are part of highly connected SDDI components, and are more likely to be detected in experimental studies. We demonstrate the utility of PPI-SDDI-PPI triangles by reconstructing myosin-actin processes in the nucleus, cytoplasm, and cytoskeleton, which were not obvious in the original PPIN. Using other complementary datatypes in place of SDDIs to form triangles, such as PubMed co-occurrences or threading information, results in a similar ability to find protein complexes.ConclusionGiven high-error PPINs with missing information, triangles of mixed datatypes are a promising direction for finding protein complexes. Integrating PPINs with SDDIs improves finding complexes. Structural SDDIs partially explain the high functional similarity of second-level neighbors in PPINs. We estimate that relatively little structural information would be sufficient for finding complexes involving most of the proteins and interactions in a typical PPIN

Angewandte numerische Modellierung der gesättigten / ungesättigten Strömung und des reaktiven Schadstofftransports - Evaluierung von Strategien der Standorterkundung und Umweltwirkungsprognose

In this thesis numerical models of variably saturated flow and reactive transport processes in porous media are employed as assessment tools in two different fields of application. The first thematic complex studied is the computer based evaluation of investigation strategies for contaminated soils and aquifers. For this purpose the 'Virtual Aquifer' (VA) concept is introduced and demonstrated by an assessment of the so called center line method for contaminant plume investigation. Errors and uncertainties in the estimation of contaminant degradation rates from center line data, which is often collected at field sites, are analysed. This is done by application at synthetic contaminated aquifers models, which are generated in the computer by numerical simulation of contaminant spreading. Monte Carlo simulations and sensitivity studies are performed to quantify the influences of sampling error magnitude, aquifer heterogeneity and model parameterisation on the estimated rate constants. In a second application example, the VA concept is used for the development and testing of a new approach for biodegradation parameter estimation. The performance of this method is studied in heterogeneous synthetic aquifers. Also, the propagation of errors and uncertainties from estimated rate parameters to a prognosis of the contaminant plume lengths is studied to obtain an indicator for the significance of the estimated degradation potential. The performance of the new parameter estimation method is assessed by comparison to frequently used approximations by first order kinetics. The second thematic complex addressed in this thesis is the evaluation of environmental impact of contaminant emissions from road constructions by type scenario modelling. Two general concepts for modelling of flow and transport, i.e. the Eulerian and the Lagrangian points of view, are combined in this study to assess the extent of leaching from contaminated demolition waste within road structures to the groundwater surface. Transport simulations are performed for a number of typical subsoil units of Germany to analyse the sensitivity of contaminant transport behaviour on subsoil properties. The relevant contaminant transport and attenuation processes in road constructions and the different subsoils are identified. The study allows to draw important conclusions on how these mechanisms could be used or enhanced to reduce contaminant leaching to groundwater.Diese Arbeit stellt die Verwendung numerischer Modelle gesättigt / ungesättigter Strömungs- und reaktiver Stofftransportprozesse in porösen Medien als Bewertungsinstrument in zwei verschiedenen Anwendungsfeldern vor. Der erste hier betrachtete Themenkomplex behandelt die computerbasierte Evaluierung von Erkundungsstrategien für kontaminierte Böden und Grundwasserleiter. Hierzu wird das Konzept der 'Virtuellen Aquifere' (VA) eingeführt und anhand einer Bewertung der sogenannten Center-Line Methodik zur Schadstofffahnenerkundung demonstriert. Die Center-Line Methode wird in der Praxis häufig zur Erhebung von Daten angewendet, auf deren Grundlage Schadstoff-Abbauratenkonstanten abgeschätzt werden können. Die Bewertung dieser Vorgehensweise wird durch eine Analyse der dabei auftretenden Fehler und Unsicherheiten vorgenommen, indem die Methode bei synthetischen kontaminierten Aquifermodellen angewendet wird, die am Computer durch numerische Simulation der Schadstoffausbreitung generierten wurden. Durch Monte-Carlo Simulationen und Sensitivitätsanalysen werden die Einflüsse von Messfehlern, Aquifer-Heterogenität und Modellparametrisierung quantifiziert. In einem zweiten Anwendungsbeispiel wird die VA-Methodik zur Ableitung und Prüfung eines neuen Ansatzes zur Schätzung von Parametern mikrobieller Abbaukinetiken angewendet. Die Eignung des Verfahrens wird in synthetischen heterogenen Aquiferen geprüft. Darüber hinaus wird die Fehler- und Unsicherheitspropagation von den geschätzten Abbauparametern zu mit diesen prognostizierte Schadstofffahnenlängen untersucht, um Indikatoren für die Aussagekraft der Parameter zu erhalten. Das Verfahren wird durch einen Vergleich mit häufig angewendeten Näherungen durch Kinetiken erster Ordnung bewertet. Der zweite im Rahmen dieser Arbeit behandelte Themenkomplex ist die Bewertung der Umweltauswirkungen von Schadstoffausträgen aus Straßenbauten durch Typszenarienmodellierung. Hier werden zwei allgemeine Konzepte zur Modellierung von Strömung und Transport, der Eulerische und der Larangesche Ansatz, miteinander kombiniert. Das Ausmaß des Schadstoffeintrags aus belastetem im Straßenbau eingesetztem Recycling-Bauschutt ins Grundwasser wird durch Einsatz der mit einander gekoppelten numerischen Modelle GeoSys/Rockflow und SMART bewertet. Die Transportsimulationen werden für eine Reihe typischer Unterbodeneinheiten Deutschlands durchgeführt, um die Sensitivität des Schadstofftransportverhaltens auf die Unterbodeneigenschaften zu untersuchen. Die relevanten Schadstofftransport- und Attenuierungsprozesse im Straßenaufbau und den Unterböden werden identifiziert. Die Studie ermöglicht wichtige Schlüsse im Hinblick eine Nutzung und Förderung dieser Mechanismen zu einer weiteren Reduktion der Schadstoffeinträge ins Grundwasser

Ästhetik des Psychedelischen: Befreiungsversuche im Kino

First tested und used for therapeutic purposes in psychiatry, LSD entered the sub- und counter-cultural field of the beatnik and hippie movement in the 1950s and 1960s as a chemical promise of individual liberation from societal restrictions. In this process, “psychedelic” movies emerged as a new genre, picking up narratives of the substance-induced freeing of the mind and developing cinematic stagings of being “high” on LSD. The article compares a selection of “psychedelic” movies produced since the 1960s, including “The Trip”, “Easy Rider”, “Altered States” and “Fear and Loathing in Las Vegas”. It focusses on the question of how narratives of the chemical transgression of the mind, understood as part of the counter-cultural movement, transformed into representations of intoxication as expression of individual fragmentation and pointless escapism at the mercy of societal constraints

Laserstrahlschweißen in Kombination mit konventionellen Techniken - Hybridschweißen

Das Lichtbogen- und das Laserstrahlschweißen kann grundsätzlich in einer Prozeßzone zum sogenannten Hybridschweißen kombiniert werden. Beim Schweißen von Stahl werden die Plasmaparameter im wesentlichen durch den vom Laserstrahl er- zeugten Metalldampf bestimmt. Dementsprechend ist bei der möglichen Wechselwirkung des Laserstrahles, z. B. im Fall des CO 2- Lasers, mit dem Plasma eine ent- sprechende Beeinflussung des Plasmas durch an- gepaßte Arbeitsgase notwendig. Eine Führung oder Konzentration des Lichtbogens kann bei entsprechend angepaßter Prozeßauslegung erfolgen. Wesentliche Aspekte hierbei sind geometrische Randbedingungen bzw. Oberflächeneffekte im Bereich der Wechselwirkungszone. So wird die Richtung des Lichtbogens bei spitzer Elektrode durch die Elektroden- richtung vorgegeben und nur bei runder Elektrode und geringen Abständen zum Laserstrahl wird eine Lichtbo- genführung in geringem Umfang beobachtet. Wesentlich stärker wird die Führung und Konzentration des Lichtbogens d urch Werkstückkanten, wie sie bei der Herstellung von Tailored Blanks vorliegen können, oder durch lokales Abtragen von Schichten geringer Leitfähigkeit durch den Laserstrahl bewirkt. Ein Beispiel für den letzten Fall ist das Hybridschweißen von Aluminium, bei dem der Laserstrahl die Oxidschicht auf der Oberfläche entfernt und so lokal durch die freigelegte Aluminiumoberfläche mit hoher Leitfähigkeit eine Führung des Lichtbogens erfolgen kann. An singulär anwendungsspezifisch durchgeführten Entwicklungen zeigt sich, daß das Hybridschweißen in wirtschaftlicher und qualitativer Hinsicht vorteilhaft eingesetzt werden kann, aufgrund von einer erhöhten Prozeßeffizienz einer verbesserten Spaltüberbrückung einer gesteigerten Produktivität reduzierten Betriebskosten. Diese Vorteile können zum gegenwärtigen Stand der Entwicklungen am ehesten dort umgesetzt werden, wo lange gerade Nähte geschweißt werden, z. B. Tailored Blanks oder Strangpreßprofile für den Schienenfahrzeugbau. Für das Fügen vo n 3D-Bauteilen aus Aluminium eröffnen sich für dünne Blechdicken Perspektiven. Um allerdings das physikalisch-technische Potential dieses Verfahrens auch breitbandig wirtschaftlich nutzen zu können, bei gleichzeitiger Erfüllung hoher Qualitätsanforderungen, sind umfangreiche Untersuchungen zu den Prozeßgrundlagen notwendig. Ohne die Erarbeitung derartiger Grundlagen für ein tieferes Prozeßverständnis z. B. in den Gebieten Plasmaeigenschaften, Wechselwirkung von Laserstrahl und Lichtbogen , Gas- und hydrodynamische Aspekte, Werkstoffkundliche Einflußmöglichkeiten, Steuerung der Energiezufuhr kann eine industrielle Umsetzung dieses Verfahrens auf nur wenige Beispiele beschränkt bleiben, wobei der jeweilige Entwicklungsaufwand überproportional hoch sein wir

Tailoring the Mechanics of Ultrathin Carbon Nanomembranes by Molecular Design

Zhang X, Neumann C, Angelova P, Beyer A, Gölzhäuser A. Tailoring the Mechanics of Ultrathin Carbon Nanomembranes by Molecular Design. Langmuir. 2014;30(27):8221-8227.Freestanding carbon nanomembranes (CNMs) with a thickness between 0.6 and 1.7 nm were prepared from self-assembled monolayers (SAMs) of diverse polyaromatic precursors via low-energy electron-induced cross-linking. The mechanical properties of CNMs were investigated using AFM bulge test, where a pressure difference was applied to the membrane and the resulting deflection was measured by atomic force microscopy. We found a correlation between the rigidity of the precursor molecules and the macroscopic mechanical stiffness of CNMs. While CNMs from rigid and condensed precursors like naphthalene and pyrene thiols prove to exhibit higher Young's moduli of 15-19 GPa, CNMs from nonfused oligophenyls possess lower Young's moduli of similar to 10 GPa. For CNMs from less densely packed SAMs, the presence of defects and nanopores plays an important role in determining their mechanical properties. The finite element method (FEM) was applied to examine the deformation profiles and simulate the pressure-deflection relationships